1
|
Dobson JR, Jacobson DA. Disrupted Endoplasmic Reticulum Ca 2+ Handling: A Harβinger of β-Cell Failure. BIOLOGY 2024; 13:379. [PMID: 38927260 PMCID: PMC11200644 DOI: 10.3390/biology13060379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/17/2024] [Accepted: 05/17/2024] [Indexed: 06/28/2024]
Abstract
The β-cell workload increases in the setting of insulin resistance and reduced β-cell mass, which occurs in type 2 and type 1 diabetes, respectively. The prolonged elevation of insulin production and secretion during the pathogenesis of diabetes results in β-cell ER stress. The depletion of β-cell Ca2+ER during ER stress activates the unfolded protein response, leading to β-cell dysfunction. Ca2+ER is involved in many pathways that are critical to β-cell function, such as protein processing, tuning organelle and cytosolic Ca2+ handling, and modulating lipid homeostasis. Mutations that promote β-cell ER stress and deplete Ca2+ER stores are associated with or cause diabetes (e.g., mutations in ryanodine receptors and insulin). Thus, improving β-cell Ca2+ER handling and reducing ER stress under diabetogenic conditions could preserve β-cell function and delay or prevent the onset of diabetes. This review focuses on how mechanisms that control β-cell Ca2+ER are perturbed during the pathogenesis of diabetes and contribute to β-cell failure.
Collapse
Affiliation(s)
| | - David A. Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA;
| |
Collapse
|
2
|
Cremer T, Hoelen H, van de Weijer ML, Janssen GM, Costa AI, van Veelen PA, Lebbink RJ, Wiertz EJHJ. Proinsulin degradation and presentation of a proinsulin B-chain autoantigen involves ER-associated protein degradation (ERAD)-enzyme UBE2G2. PLoS One 2024; 19:e0287877. [PMID: 38787820 PMCID: PMC11125532 DOI: 10.1371/journal.pone.0287877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 03/14/2024] [Indexed: 05/26/2024] Open
Abstract
Type 1 diabetes (T1D) is characterized by HLA class I-mediated presentation of autoantigens on the surface of pancreatic β-cells. Recognition of these autoantigens by CD8+ T cells results in the destruction of pancreatic β-cells and, consequently, insulin deficiency. Most epitopes presented at the surface of β-cells derive from the insulin precursor molecule proinsulin. The intracellular processing pathway(s) involved in the generation of these peptides are poorly defined. In this study, we show that a proinsulin B-chain antigen (PPIB5-14) originates from proinsulin molecules that are processed by ER-associated protein degradation (ERAD) and thus originate from ER-resident proteins. Furthermore, screening genes encoding for E2 ubiquitin conjugating enzymes, we identified UBE2G2 to be involved in proinsulin degradation and subsequent presentation of the PPIB10-18 autoantigen. These insights into the pathway involved in the generation of insulin-derived peptides emphasize the importance of proinsulin processing in the ER to T1D pathogenesis and identify novel targets for future T1D therapies.
Collapse
Affiliation(s)
- Tom Cremer
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, The Netherlands
| | - Hanneke Hoelen
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - George M. Janssen
- Department of Proteomics and Metabolomics, Leiden University Medical Center, Leiden, The Netherlands
| | - Ana I. Costa
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Peter A. van Veelen
- Department of Proteomics and Metabolomics, Leiden University Medical Center, Leiden, The Netherlands
| | - Robert Jan Lebbink
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | |
Collapse
|
3
|
Vaňková M, Vejražková D, Lukášová P, Včelák J, Chocholová D, Bendlová B. Age-Related Changes in Proinsulin Processing in Normoglycemic Individuals. Physiol Res 2023; 72:S389-S397. [PMID: 38116775 DOI: 10.33549/physiolres.935181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024] Open
Abstract
In order to understand the pathological changes associated with glucose homeostasis in old age, it is necessary to know the natural changes in the processing of proinsulin to mature insulin. While there is abundant information about insulin production and function in diabetics, the situation in healthy adults and the elderly has surprisingly rarely been investigated. The aim of the study was to determine how proinsulin secretion changes in individuals with normal glucose tolerance during the process of natural aging. A total of 761 individuals (539 women, 222 men) aged 18-90 years with normal fasting glycemia (less than 5.6 mmol/l) were divided into five groups according to age. Body composition and levels of fasting blood glucose, proinsulin, insulin, and C-peptide were determined, and the ratios of proinsulin to both insulin and C-peptide were calculated. The homeostasis model of ?-cell function (HOMA F) and peripheral insulin resistance (HOMA R) were calculated. The effect of age was assessed using an ANOVA model consisting of the factors sex, age, and sex × age interaction. Statgraphics Centurion v. XVIII statistical software was used. Glycemia, insulin, C-peptide and HOMA R increased in both sexes up to 75 years. On the contrary, proinsulin levels as well as proinsulin/insulin and proinsulin/C-peptide ratios decreased with age up to 75 years. In normoglycemic and normotolerant people, both women and men, the aging process is associated with decreased insulin sensitivity compensated by potentiation of insulin production. In older age, there is also a gradual decrease in circulating proinsulin, which can be explained by its more efficient processing into active insulin by matured healthy beta cells.
Collapse
Affiliation(s)
- M Vaňková
- Institute of Endocrinology, Prague, Czech Republic, Faculty of Science, Charles University, Prague, Czech Republic
| | | | | | | | | | | |
Collapse
|
4
|
Dumitrescu A, Jokinen E, Paatero A, Kellosalo J, Paavilainen VO, Lähdesmäki H. TSignal: a transformer model for signal peptide prediction. Bioinformatics 2023; 39:i347-i356. [PMID: 37387131 DOI: 10.1093/bioinformatics/btad228] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/01/2023] Open
Abstract
MOTIVATION Signal peptides (SPs) are short amino acid segments present at the N-terminus of newly synthesized proteins that facilitate protein translocation into the lumen of the endoplasmic reticulum, after which they are cleaved off. Specific regions of SPs influence the efficiency of protein translocation, and small changes in their primary structure can abolish protein secretion altogether. The lack of conserved motifs across SPs, sensitivity to mutations, and variability in the length of the peptides make SP prediction a challenging task that has been extensively pursued over the years. RESULTS We introduce TSignal, a deep transformer-based neural network architecture that utilizes BERT language models and dot-product attention techniques. TSignal predicts the presence of SPs and the cleavage site between the SP and the translocated mature protein. We use common benchmark datasets and show competitive accuracy in terms of SP presence prediction and state-of-the-art accuracy in terms of cleavage site prediction for most of the SP types and organism groups. We further illustrate that our fully data-driven trained model identifies useful biological information on heterogeneous test sequences. AVAILABILITY AND IMPLEMENTATION TSignal is available at: https://github.com/Dumitrescu-Alexandru/TSignal.
Collapse
Affiliation(s)
- Alexandru Dumitrescu
- Department of Computer Science, Aalto University, Espoo 02150, Finland
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki 00014, Finland
| | - Emmi Jokinen
- Department of Computer Science, Aalto University, Espoo 02150, Finland
| | - Anja Paatero
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki 00014, Finland
| | - Juho Kellosalo
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki 00014, Finland
| | - Ville O Paavilainen
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki 00014, Finland
| | - Harri Lähdesmäki
- Department of Computer Science, Aalto University, Espoo 02150, Finland
| |
Collapse
|
5
|
Ataie-Ashtiani S, Forbes B. A Review of the Biosynthesis and Structural Implications of Insulin Gene Mutations Linked to Human Disease. Cells 2023; 12:cells12071008. [PMID: 37048081 PMCID: PMC10093311 DOI: 10.3390/cells12071008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/13/2023] [Accepted: 03/15/2023] [Indexed: 03/29/2023] Open
Abstract
The discovery of the insulin hormone over 100 years ago, and its subsequent therapeutic application, marked a key landmark in the history of medicine and medical research. The many roles insulin plays in cell metabolism and growth have been revealed by extensive investigations into the structure and function of insulin, the insulin tyrosine kinase receptor (IR), as well as the signalling cascades, which occur upon insulin binding to the IR. In this review, the insulin gene mutations identified as causing disease and the structural implications of these mutations will be discussed. Over 100 studies were evaluated by one reviewing author, and over 70 insulin gene mutations were identified. Mutations may impair insulin gene transcription and translation, preproinsulin trafficking and proinsulin sorting, or insulin-IR interactions. A better understanding of insulin gene mutations and the resultant pathophysiology can give essential insight into the molecular mechanisms underlying impaired insulin biosynthesis and insulin-IR interaction.
Collapse
|
6
|
Cook TW, Wilstermann AM, Mitchell JT, Arnold NE, Rajasekaran S, Bupp CP, Prokop JW. Understanding Insulin in the Age of Precision Medicine and Big Data: Under-Explored Nature of Genomics. Biomolecules 2023; 13:257. [PMID: 36830626 PMCID: PMC9953665 DOI: 10.3390/biom13020257] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/20/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023] Open
Abstract
Insulin is amongst the human genome's most well-studied genes/proteins due to its connection to metabolic health. Within this article, we review literature and data to build a knowledge base of Insulin (INS) genetics that influence transcription, transcript processing, translation, hormone maturation, secretion, receptor binding, and metabolism while highlighting the future needs of insulin research. The INS gene region has 2076 unique variants from population genetics. Several variants are found near the transcriptional start site, enhancers, and following the INS transcripts that might influence the readthrough fusion transcript INS-IGF2. This INS-IGF2 transcript splice site was confirmed within hundreds of pancreatic RNAseq samples, lacks drift based on human genome sequencing, and has possible elevated expression due to viral regulation within the liver. Moreover, a rare, poorly characterized African population-enriched variant of INS-IGF2 results in a loss of the stop codon. INS transcript UTR variants rs689 and rs3842753, associated with type 1 diabetes, are found in many pancreatic RNAseq datasets with an elevation of the 3'UTR alternatively spliced INS transcript. Finally, by combining literature, evolutionary profiling, and structural biology, we map rare missense variants that influence preproinsulin translation, proinsulin processing, dimer/hexamer secretory storage, receptor activation, and C-peptide detection for quasi-insulin blood measurements.
Collapse
Affiliation(s)
- Taylor W. Cook
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | | | - Jackson T. Mitchell
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | - Nicholas E. Arnold
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | - Surender Rajasekaran
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
- Office of Research, Corewell Health, Grand Rapids, MI 49503, USA
| | - Caleb P. Bupp
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
- Division of Medical Genetics, Corewell Health, Grand Rapids, MI 49503, USA
| | - Jeremy W. Prokop
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
- Office of Research, Corewell Health, Grand Rapids, MI 49503, USA
| |
Collapse
|
7
|
Yang J, Zhen J, Feng W, Fan Z, Ding L, Yang X, Huang Y, Shu H, Xie J, Li X, Qiao J, Fan Y, Sun J, Li N, Liu T, Wang S, Zhang X, Arvan P, Liu M. IER3IP1 is critical for maintaining glucose homeostasis through regulating the endoplasmic reticulum function and survival of β cells. Proc Natl Acad Sci U S A 2022; 119:e2204443119. [PMID: 36322741 PMCID: PMC9659391 DOI: 10.1073/pnas.2204443119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 10/06/2022] [Indexed: 05/04/2023] Open
Abstract
Recessive mutations in IER3IP1 (immediate early response 3 interacting protein 1) cause a syndrome of microcephaly, epilepsy, and permanent neonatal diabetes (MEDS). IER3IP1 encodes an endoplasmic reticulum (ER) membrane protein, which is crucial for brain development; however, the role of IER3IP1 in β cells remains unknown. We have generated two mouse models with either constitutive or inducible IER3IP1 deletion in β cells, named IER3IP1-βKO and IER3IP1-iβKO, respectively. We found that IER3IP1-βKO causes severe early-onset, insulin-deficient diabetes. Functional studies revealed a markedly dilated β-cell ER along with increased proinsulin misfolding and elevated expression of the ER chaperones, including PDI, ERO1, BiP, and P58IPK. Islet transcriptome analysis confirmed by qRT-PCR revealed decreased expression of genes associated with β-cell maturation, cell cycle, and antiapoptotic genes, accompanied by increased expression of antiproliferation genes. Indeed, multiple independent approaches further demonstrated that IER3IP1-βKO impaired β-cell maturation and proliferation, along with increased condensation of β-cell nuclear chromatin. Inducible β-cell IER3IP1 deletion in adult (8-wk-old) mice induced a similar diabetic phenotype, suggesting that IER3IP1 is also critical for function and survival even after β-cell early development. Importantly, IER3IP1 was decreased in β cells of patients with type 2 diabetes (T2D), suggesting an association of IER3IP1 deficiency with β-cell dysfunction in the more-common form of diabetes. These data not only uncover a critical role of IER3IP1 in β cells but also provide insight into molecular basis of diabetes caused by IER3IP1 mutations.
Collapse
Affiliation(s)
- Jing Yang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Jinyang Zhen
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Wenli Feng
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Zhenqian Fan
- Department of Endocrinology, The Second Hospital of Tianjin Medical University, Tianjin 300211, China
| | - Li Ding
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Xiaoyun Yang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Yumeng Huang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Hua Shu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Jing Xie
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Xin Li
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Jingting Qiao
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Yuxin Fan
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Jinhong Sun
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Na Li
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Tengli Liu
- Organ Transplant Center, Tianjin First Central Hospital, Nankai University, Tianjin 300192, China
- NHC Key Laboratory for Critical Care Medicine, Tianjin First Central Hospital, Tianjin 300384, China
| | - Shusen Wang
- Organ Transplant Center, Tianjin First Central Hospital, Nankai University, Tianjin 300192, China
- NHC Key Laboratory for Critical Care Medicine, Tianjin First Central Hospital, Tianjin 300384, China
- Human Islet Resource Center, Tianjin First Central Hospital, Tianjin 300384, China
| | - Xiaona Zhang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| |
Collapse
|
8
|
Abstract
Insulin secretion is regulated in multiple steps, and one of the main steps is in the endoplasmic reticulum (ER). Here, we show that UDP-glucose induces proinsulin ubiquitination by cereblon, and uridine binds and competes for proinsulin degradation and behaves as sustainable insulin secretagogue. Using insulin mutagenesis of neonatal diabetes variant-C43G and maturity-onset diabetes of the young 10 (MODY10) variant-R46Q, UDP-glucose:glycoprotein glucosyltransferase 1 (UGGT1) protects cereblon-dependent proinsulin ubiquitination in the ER. Cereblon is a ligand-inducible E3 ubiquitin ligase, and we found that UDP-glucose is the first identified endogenous proinsulin protein degrader. Uridine-containing compounds, such as uridine, UMP, UTP, and UDP-galactose, inhibit cereblon-dependent proinsulin degradation and stimulate insulin secretion from 3 to 24 h after administration in β-cell lines as well as mice. This late and long-term insulin secretion stimulation is designated a day sustainable insulin secretion stimulation. Uridine-containing compounds are designated as proinsulin degradation regulators.
Collapse
|
9
|
Xu X, Arunagiri A, Haataja L, Alam M, Ji S, Qi L, Tsai B, Liu M, Arvan P. Proteasomal degradation of wild-type proinsulin in pancreatic beta cells. J Biol Chem 2022; 298:102406. [PMID: 35988641 PMCID: PMC9486123 DOI: 10.1016/j.jbc.2022.102406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/25/2022] [Accepted: 07/26/2022] [Indexed: 11/22/2022] Open
Abstract
Preproinsulin entry into the endoplasmic reticulum yields proinsulin, and its subsequent delivery to the distal secretory pathway leads to processing, storage, and secretion of mature insulin. Multiple groups have reported that treatment of pancreatic beta cell lines, rodent pancreatic islets, or human islets with proteasome inhibitors leads to diminished proinsulin and insulin protein levels, diminished glucose-stimulated insulin secretion, and changes in beta-cell gene expression that ultimately lead to beta-cell death. However, these studies have mostly examined treatment times far beyond that needed to achieve acute proteasomal inhibition. Here, we report that although proteasomal inhibition immediately downregulates new proinsulin biosynthesis, it nevertheless acutely increases beta-cell proinsulin levels in pancreatic beta cell lines, rodent pancreatic islets, and human islets, indicating rescue of a pool of recently synthesized WT INS gene product that would otherwise be routed to proteasomal disposal. Our pharmacological evidence suggests that this disposal most likely reflects ongoing endoplasmic reticulum–associated protein degradation. However, we found that within 60 min after proteasomal inhibition, intracellular proinsulin levels begin to fall in conjunction with increased phosphorylation of eukaryotic initiation factor 2 alpha, which can be inhibited by blocking the general control nonderepressible 2 kinase. Together, these data demonstrate that a meaningful subfraction of newly synthesized INS gene product undergoes rapid proteasomal disposal. We propose that free amino acids derived from proteasomal proteolysis may potentially participate in suppressing general control nonderepressible 2 kinase activity to maintain ongoing proinsulin biosynthesis.
Collapse
Affiliation(s)
- Xiaoxi Xu
- The Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, MI 48105; Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China 300052
| | - Anoop Arunagiri
- The Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, MI 48105
| | - Leena Haataja
- The Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, MI 48105
| | - Maroof Alam
- The Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, MI 48105
| | - Shuhui Ji
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China 300052
| | - Ling Qi
- Departments of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Billy Tsai
- Departments of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China 300052.
| | - Peter Arvan
- The Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, MI 48105.
| |
Collapse
|
10
|
Lyu Z, Sycks MM, Espinoza MF, Nguyen KK, Montoya MR, Galapate CM, Mei L, Genereux JC. Monitoring Protein Import into the Endoplasmic Reticulum in Living Cells with Proximity Labeling. ACS Chem Biol 2022; 17:1963-1977. [PMID: 35675579 DOI: 10.1021/acschembio.2c00405] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The proper trafficking of eukaryotic proteins is essential to cellular function. Genetic, environmental, and other stresses can induce protein mistargeting and, in turn, threaten cellular protein homeostasis. Current methods for measuring protein mistargeting are difficult to translate to living cells, and thus the role of cellular signaling networks in stress-dependent protein mistargeting processes, such as ER pre-emptive quality control (ER pQC), is difficult to parse. Herein, we use genetically encoded peroxidases to characterize protein import into the endoplasmic reticulum (ER). We show that the ERHRP/cytAPEX pair provides good selectivity and sensitivity for both multiplexed protein labeling and for identifying protein mistargeting, using the known ER pQC substrate transthyretin (TTR). Although ERHRP labeling induces formation of detergent-resistant TTR aggregates, this is minimized by using low ERHRP expression, without loss of labeling efficiency. cytAPEX labeling recovers TTR that is mistargeted as a consequence of Sec61 inhibition or ER stress-induced ER pQC. Furthermore, we discover that stress-free activation of the ER stress-associated transcription factor ATF6 recapitulates the TTR import deficiency of ER pQC. Hence, proximity labeling is an effective strategy for characterizing factors that influence ER protein import in living cells.
Collapse
Affiliation(s)
- Ziqi Lyu
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Melody M Sycks
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Mateo F Espinoza
- Graduate Program of Microbiology, University of California, Riverside, California 92521, United States
| | - Khanh K Nguyen
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Maureen R Montoya
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Cheska M Galapate
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Liangyong Mei
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Joseph C Genereux
- Department of Chemistry, University of California, Riverside, California 92521, United States.,Graduate Program of Microbiology, University of California, Riverside, California 92521, United States
| |
Collapse
|
11
|
Yang Y, Glidden MD, Dhayalan B, Zaykov AN, Chen YS, Wickramasinghe NP, DiMarchi RD, Weiss MA. Peptide Model of the Mutant Proinsulin Syndrome. II. Nascent Structure and Biological Implications. Front Endocrinol (Lausanne) 2022; 13:821091. [PMID: 35299958 PMCID: PMC8922542 DOI: 10.3389/fendo.2022.821091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/21/2022] [Indexed: 11/13/2022] Open
Abstract
Toxic misfolding of proinsulin variants in β-cells defines a monogenic diabetes syndrome, designated mutant INS-gene induced diabetes of the young (MIDY). In our first study (previous article in this issue), we described a one-disulfide peptide model of a proinsulin folding intermediate and its use to study such variants. The mutations (LeuB15→Pro, LeuA16→Pro, and PheB24→Ser) probe residues conserved among vertebrate insulins. In this companion study, we describe 1H and 1H-13C NMR studies of the peptides; key NMR resonance assignments were verified by synthetic 13C-labeling. Parent spectra retain nativelike features in the neighborhood of the single disulfide bridge (cystine B19-A20), including secondary NMR chemical shifts and nonlocal nuclear Overhauser effects. This partial fold engages wild-type side chains LeuB15, LeuA16 and PheB24 at the nexus of nativelike α-helices α1 and α3 (as defined in native proinsulin) and flanking β-strand (residues B24-B26). The variant peptides exhibit successive structural perturbations in order: parent (most organized) > SerB24 >> ProA16 > ProB15 (least organized). The same order pertains to (a) overall α-helix content as probed by circular dichroism, (b) synthetic yields of corresponding three-disulfide insulin analogs, and (c) ER stress induced in cell culture by corresponding mutant proinsulins. These findings suggest that this and related peptide models will provide a general platform for classification of MIDY mutations based on molecular mechanisms by which nascent disulfide pairing is impaired. We propose that the syndrome's variable phenotypic spectrum-onsets ranging from the neonatal period to later in childhood or adolescence-reflects structural features of respective folding intermediates.
Collapse
Affiliation(s)
- Yanwu Yang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Michael D. Glidden
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH, United States
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, United States
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | | | - Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Nalinda P. Wickramasinghe
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | | | - Michael A. Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| |
Collapse
|
12
|
Xu X, Huang Y, Li X, Arvan P, Liu M. The Role of TRAPγ/SSR3 in Preproinsulin Translocation Into the Endoplasmic Reticulum. Diabetes 2022; 71:440-452. [PMID: 34857543 PMCID: PMC8893945 DOI: 10.2337/db21-0638] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 11/18/2021] [Indexed: 11/13/2022]
Abstract
In the endoplasmic reticulum (ER), the translocation-associated protein complex (TRAP), also called signal sequence receptor (SSR), includes four integral membrane proteins TRAPα/SSR1, TRAPβ/SSR2, and TRAPδ/SSR4 with the bulk of their extramembranous portions primarily in the ER lumen, whereas the extramembranous portion of TRAPγ/SSR3 is primarily cytosolic. Individually diminished expression of either TRAPα/SSR1, TRAPβ/SSR2, or TRAPδ/SSR4 mRNA is known in each case to lower TRAPα/SSR1 protein levels, leading to impaired proinsulin biosynthesis, whereas forced expression of TRAPα/SSR1 at least partially suppresses the proinsulin biosynthetic defect. Here, we report that diminished TRAPγ/SSR3 expression in pancreatic β-cells leaves TRAPα/SSR1 levels unaffected while nevertheless inhibiting cotranslational and posttranslational translocation of preproinsulin into the ER. Crucially, acute exposure to high glucose leads to a rapid upregulation of both TRAPγ/SSR3 and proinsulin protein without change in the respective mRNA levels, as observed in cultured rodent β-cell lines and confirmed in human islets. Strikingly, pancreatic β-cells with suppressed TRAPγ/SSR3 expression are blocked in glucose-dependent upregulation of proinsulin (or insulin) biosynthesis. Most remarkably, overexpression of TRAPγ/SSR3 in control β-cells raises proinsulin levels, even without boosting extracellular glucose. The data suggest the possibility that TRAPγ/SSR3 may fulfill a rate-limiting function in preproinsulin translocation across the ER membrane for proinsulin biosynthesis.
Collapse
Affiliation(s)
- Xiaoxi Xu
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, MI
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Yumeng Huang
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, MI
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Xin Li
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, MI
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, MI
- Corresponding authors: Peter Arvan, , and Ming Liu,
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
- Corresponding authors: Peter Arvan, , and Ming Liu,
| |
Collapse
|
13
|
Gopi S, Gowri P, Panda JK, Sathyanarayana SO, Gupta S, Chandru S, Chandni R, Raghupathy P, Dayal D, Mohan V, Radha V. Insulin gene mutations linked to permanent neonatal diabetes mellitus in Indian population. J Diabetes Complications 2021; 35:108022. [PMID: 34593315 DOI: 10.1016/j.jdiacomp.2021.108022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/11/2021] [Accepted: 08/11/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND AIM Neonatal diabetes mellitus (NDM) is a rare monogenic disorder of pancreatic beta cell mass and/or function. In the present study we aimed to evaluate the INS gene mutations in a cohort of children with Permanent Neonatal Diabetes Mellitus (PNDM) and to explore the clinical and genetic characteristics of PNDM caused by INS mutations. METHODS Direct sequencing of all exons of INS genes was carried out in 189 children with PNDM. Clinical and biochemical data were collected and correlated. The pathogenicity of mutations was determined based on the American College of Medical Genetics and Genomics and Association of Medical Pathology guidelines. RESULTS Two novel mutations (His34Pro, Leu35Met) in a compound heterozygous state and seven known mutations (Gly32Ser, Phe48Cys, Arg89Cys, Cys96Tyr, Ser98Ile, Try108Asp and Cys109Phe) in the INS gene were identified in 8 patients out of the total of 189 PNDM children studied. Four mutations were involved in defects with disulphide bond formation and hence were in crucial regions of the gene. All the mutations were de novo in origin. CONCLUSIONS This is the first comprehensive study from India to investigate the insulin gene mutations in PNDM and to show that INS gene mutations also contribute to the causation of PNDM.
Collapse
Affiliation(s)
- Sundaramoorthy Gopi
- Department of Molecular Genetics, Madras Diabetes Research Foundation, ICMR Centre for Advanced Research on Diabetes, University of Madras, Chennai, India
| | | | | | | | - Sunil Gupta
- Diabetes Care n' Research Centre, Ramdaspeth, Nagpur, Maharashtra, India
| | | | | | | | - Devi Dayal
- Department of Paediatrics, Postgraduate Institute of Medical Education & Research, Chandigarh, India
| | - Viswanathan Mohan
- Dr. Mohan's Diabetes Specialities Centre, Chennai, Tamilnadu, India; Department of Diabetology, Madras Diabetes Research Foundation, Chennai, India; Dr. Mohan's Diabetes Specialties Centre, IDF Centre of Education, Chennai, India
| | - Venkatesan Radha
- Department of Molecular Genetics, Madras Diabetes Research Foundation, ICMR Centre for Advanced Research on Diabetes, University of Madras, Chennai, India.
| |
Collapse
|
14
|
Alam M, Arunagiri A, Haataja L, Torres M, Larkin D, Kappler J, Jin N, Arvan P. Predisposition to Proinsulin Misfolding as a Genetic Risk to Diet-Induced Diabetes. Diabetes 2021; 70:2580-2594. [PMID: 34462258 PMCID: PMC8564407 DOI: 10.2337/db21-0422] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/10/2021] [Indexed: 02/06/2023]
Abstract
Throughout evolution, proinsulin has exhibited significant sequence variation in both C-peptide and insulin moieties. As the proinsulin coding sequence evolves, the gene product continues to be under selection pressure both for ultimate insulin bioactivity and for the ability of proinsulin to be folded for export through the secretory pathway of pancreatic β-cells. The substitution proinsulin-R(B22)E is known to yield a bioactive insulin, although R(B22)Q has been reported as a mutation that falls within the spectrum of mutant INS-gene-induced diabetes of youth. Here, we have studied mice expressing heterozygous (or homozygous) proinsulin-R(B22)E knocked into the Ins2 locus. Neither females nor males bearing the heterozygous mutation developed diabetes at any age examined, but subtle evidence of increased proinsulin misfolding in the endoplasmic reticulum is demonstrable in isolated islets from the heterozygotes. Moreover, males have indications of glucose intolerance, and within a few weeks of exposure to a high-fat diet, they developed frank diabetes. Diabetes was more severe in homozygotes, and the development of disease paralleled a progressive heterogeneity of β-cells with increasing fractions of proinsulin-rich/insulin-poor cells as well as glucagon-positive cells. Evidently, subthreshold predisposition to proinsulin misfolding can go undetected but provides genetic susceptibility to diet-induced β-cell failure.
Collapse
Affiliation(s)
- Maroof Alam
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Anoop Arunagiri
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Leena Haataja
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Mauricio Torres
- Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI
| | - Dennis Larkin
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - John Kappler
- Barbara Davis Center for Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO
- Department of Immunology and Genomic Medicine, National Jewish Health, Denver, CO
| | - Niyun Jin
- Barbara Davis Center for Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO
- Department of Immunology and Genomic Medicine, National Jewish Health, Denver, CO
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| |
Collapse
|
15
|
Lyu Z, Genereux JC. Methodologies for Measuring Protein Trafficking across Cellular Membranes. Chempluschem 2021; 86:1397-1415. [PMID: 34636167 DOI: 10.1002/cplu.202100304] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/19/2021] [Indexed: 12/11/2022]
Abstract
Nearly all proteins are synthesized in the cytosol. The majority of this proteome must be trafficked elsewhere, such as to membranes, to subcellular compartments, or outside of the cell. Proper trafficking of nascent protein is necessary for protein folding, maturation, quality control and cellular and organismal health. To better understand cellular biology, molecular and chemical technologies to properly characterize protein trafficking (and mistrafficking) have been developed and applied. Herein, we take a biochemical perspective to review technologies that enable spatial and temporal measurement of protein distribution, focusing on both the most widely adopted methodologies and exciting emerging approaches.
Collapse
Affiliation(s)
- Ziqi Lyu
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, 92521, Riverside, CA, USA
| | - Joseph C Genereux
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, 92521, Riverside, CA, USA
| |
Collapse
|
16
|
Germanos M, Gao A, Taper M, Yau B, Kebede MA. Inside the Insulin Secretory Granule. Metabolites 2021; 11:metabo11080515. [PMID: 34436456 PMCID: PMC8401130 DOI: 10.3390/metabo11080515] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/03/2021] [Accepted: 08/03/2021] [Indexed: 12/19/2022] Open
Abstract
The pancreatic β-cell is purpose-built for the production and secretion of insulin, the only hormone that can remove glucose from the bloodstream. Insulin is kept inside miniature membrane-bound storage compartments known as secretory granules (SGs), and these specialized organelles can readily fuse with the plasma membrane upon cellular stimulation to release insulin. Insulin is synthesized in the endoplasmic reticulum (ER) as a biologically inactive precursor, proinsulin, along with several other proteins that will also become members of the insulin SG. Their coordinated synthesis enables synchronized transit through the ER and Golgi apparatus for congregation at the trans-Golgi network, the initiating site of SG biogenesis. Here, proinsulin and its constituents enter the SG where conditions are optimized for proinsulin processing into insulin and subsequent insulin storage. A healthy β-cell is continually generating SGs to supply insulin in vast excess to what is secreted. Conversely, in type 2 diabetes (T2D), the inability of failing β-cells to secrete may be due to the limited biosynthesis of new insulin. Factors that drive the formation and maturation of SGs and thus the production of insulin are therefore critical for systemic glucose control. Here, we detail the formative hours of the insulin SG from the luminal perspective. We do this by mapping the journey of individual members of the SG as they contribute to its genesis.
Collapse
|
17
|
Ikle JM, Gloyn AL. 100 YEARS OF INSULIN: A brief history of diabetes genetics: insights for pancreatic beta-cell development and function. J Endocrinol 2021; 250:R23-R35. [PMID: 34196608 PMCID: PMC9037733 DOI: 10.1530/joe-21-0067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 06/30/2021] [Indexed: 12/30/2022]
Abstract
Since the discovery of insulin 100 years ago, our knowledge and understanding of diabetes have grown exponentially. Specifically, with regards to the genetics underlying diabetes risk, our discoveries have paralleled developments in our understanding of the human genome and our ability to study genomics at scale; these advancements in genetics have both accompanied and led to those in diabetes treatment. This review will explore the timeline and history of gene discovery and how this has coincided with progress in the fields of genomics. Examples of genetic causes of monogenic diabetes are presented and the continuing expansion of allelic series in these genes and the challenges these now cause for diagnostic interpretation along with opportunities for patient stratification are discussed.
Collapse
Affiliation(s)
- Jennifer M Ikle
- Division of Endocrinology, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
| | - Anna L Gloyn
- Division of Endocrinology, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
- Stanford Diabetes Research Center, Stanford University, Stanford, California, USA
| |
Collapse
|
18
|
Sims EK, Carr ALJ, Oram RA, DiMeglio LA, Evans-Molina C. 100 years of insulin: celebrating the past, present and future of diabetes therapy. Nat Med 2021; 27:1154-1164. [PMID: 34267380 PMCID: PMC8802620 DOI: 10.1038/s41591-021-01418-2] [Citation(s) in RCA: 80] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 05/28/2021] [Indexed: 02/04/2023]
Abstract
The year 2021 marks the centennial of Banting and Best's landmark description of the discovery of insulin. This discovery and insulin's rapid clinical deployment effectively transformed type 1 diabetes from a fatal diagnosis into a medically manageable chronic condition. In this Review, we describe key accomplishments leading to and building on this momentous occasion in medical history, including advancements in our understanding of the role of insulin in diabetes pathophysiology, the molecular characterization of insulin and the clinical use of insulin. Achievements are also viewed through the lens of patients impacted by insulin therapy and the evolution of insulin pharmacokinetics and delivery over the past 100 years. Finally, we reflect on the future of insulin therapy and diabetes treatment, as well as challenges to be addressed moving forward, so that the full potential of this transformative discovery may be realized.
Collapse
Affiliation(s)
- Emily K Sims
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
- The Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
- The Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Alice L J Carr
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - Richard A Oram
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
- The Academic Kidney Unit, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK
| | - Linda A DiMeglio
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
- The Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
- The Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Carmella Evans-Molina
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA.
- The Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA.
- The Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
- Roudebush VA Medical Center, Indianapolis, IN, USA.
| |
Collapse
|
19
|
Liu M, Huang Y, Xu X, Li X, Alam M, Arunagiri A, Haataja L, Ding L, Wang S, Itkin-Ansari P, Kaufman RJ, Tsai B, Qi L, Arvan P. Normal and defective pathways in biogenesis and maintenance of the insulin storage pool. J Clin Invest 2021; 131:142240. [PMID: 33463547 PMCID: PMC7810482 DOI: 10.1172/jci142240] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Both basal and glucose-stimulated insulin release occur primarily by insulin secretory granule exocytosis from pancreatic β cells, and both are needed to maintain normoglycemia. Loss of insulin-secreting β cells, accompanied by abnormal glucose tolerance, may involve simple exhaustion of insulin reserves (which, by immunostaining, appears as a loss of β cell identity), or β cell dedifferentiation, or β cell death. While various sensing and signaling defects can result in diminished insulin secretion, somewhat less attention has been paid to diabetes risk caused by insufficiency in the biosynthetic generation and maintenance of the total insulin granule storage pool. This Review offers an overview of insulin biosynthesis, beginning with the preproinsulin mRNA (translation and translocation into the ER), proinsulin folding and export from the ER, and delivery via the Golgi complex to secretory granules for conversion to insulin and ultimate hormone storage. All of these steps are needed for generation and maintenance of the total insulin granule pool, and defects in any of these steps may, weakly or strongly, perturb glycemic control. The foregoing considerations have obvious potential relevance to the pathogenesis of type 2 diabetes and some forms of monogenic diabetes; conceivably, several of these concepts might also have implications for β cell failure in type 1 diabetes.
Collapse
Affiliation(s)
- Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Yumeng Huang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Xiaoxi Xu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Xin Li
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Maroof Alam
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Anoop Arunagiri
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Leena Haataja
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Li Ding
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Shusen Wang
- Organ Transplant Center, Tianjin First Central Hospital, Tianjin, China
| | | | - Randal J. Kaufman
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Billy Tsai
- Department of Cell and Developmental Biology, and
| | - Ling Qi
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| |
Collapse
|
20
|
Yang Y, Shu H, Hu J, Li L, Wang J, Chen T, Zhen J, Sun J, Feng W, Xiong Y, Huang Y, Li X, Zhang K, Fan Z, Guo H, Liu M. A Novel Nonsense INS Mutation Causes Inefficient Preproinsulin Translocation Into the Endoplasmic Reticulum. Front Endocrinol (Lausanne) 2021; 12:774634. [PMID: 35069438 PMCID: PMC8769375 DOI: 10.3389/fendo.2021.774634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Preproinsulin (PPI) translocation across the membrane of the endoplasmic reticulum (ER) is the first and critical step of insulin biosynthesis. Inefficient PPI translocation caused by signal peptide (SP) mutations can lead to β-cell failure and diabetes. However, the effect of proinsulin domain on the efficiency of PPI translocation remains unknown. With whole exome sequencing, we identified a novel INS nonsense mutation resulting in an early termination at the 46th residue of PPI (PPI-R46X) in two unrelated patients with early-onset diabetes. We examined biological behaviors of the mutant and compared them to that of an established neonatal diabetes causing mutant PPI-C96Y. Although both mutants were retained in the cells, unlike C96Y, R46X did not induce ER stress or form abnormal disulfide-linked proinsulin complexes. More importantly, R46X did not interact with co-expressed wild-type (WT) proinsulin in the ER, and did not impair proinsulin-WT folding, trafficking, and insulin production. Metabolic labeling experiments established that, despite with an intact SP, R46X failed to be efficiently translocated into the ER, suggesting that proinsulin domain downstream of SP plays an important unrecognized role in PPI translocation across the ER membrane. The study not only expends the list of INS mutations associated with diabetes, but also provides genetic and biological evidence underlying the regulation mechanism of PPI translocation.
Collapse
Affiliation(s)
- Ying Yang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Hua Shu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Jingxin Hu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Lei Li
- Department of Endocrinology, The Second Part of Jilin University First Hospital, Jilin, China
| | - Jianyu Wang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Tingting Chen
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Jinyang Zhen
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Jinhong Sun
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Wenli Feng
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Yi Xiong
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Yumeng Huang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Xin Li
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Kai Zhang
- Department of Technology Services, RSR Tianjin Biotech Co., Tianjin, China
| | - Zhenqian Fan
- Department of Endocrinology and Metabolism, The Second Hospital of Tianjin Medical University, Tianjin, China
- *Correspondence: Ming Liu, ; Zhenqian Fan, ; Hui Guo,
| | - Hui Guo
- Department of Endocrinology, The Second Part of Jilin University First Hospital, Jilin, China
- *Correspondence: Ming Liu, ; Zhenqian Fan, ; Hui Guo,
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
- *Correspondence: Ming Liu, ; Zhenqian Fan, ; Hui Guo,
| |
Collapse
|
21
|
Wang H, Saint-Martin C, Xu J, Ding L, Wang R, Feng W, Liu M, Shu H, Fan Z, Haataja L, Arvan P, Bellanné-Chantelot C, Cui J, Huang Y. Biological behaviors of mutant proinsulin contribute to the phenotypic spectrum of diabetes associated with insulin gene mutations. Mol Cell Endocrinol 2020; 518:111025. [PMID: 32916194 PMCID: PMC7734662 DOI: 10.1016/j.mce.2020.111025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 08/30/2020] [Accepted: 08/31/2020] [Indexed: 02/06/2023]
Abstract
Insulin gene mutation is the second most common cause of neonatal diabetes (NDM). It is also one of the genes involved in maturity-onset diabetes of the young (MODY). We aim to investigate molecular behaviors of different INS gene variants that may correlate with the clinical spectrum of diabetes phenotypes. In this study, we concentrated on two previously uncharacterized MODY-causing mutants, proinsulin-p.Gly44Arg [G(B20)R] and p.Pro52Leu [P(B28)L] (a novel mutant identified in one French family), and an NDM causing proinsulin-p.(Cys96Tyr) [C(A7)Y]. We find that these proinsulin mutants exhibit impaired oxidative folding in the endoplasmic reticulum (ER) with blocked ER export, ER stress, and apoptosis. Importantly, the proinsulin mutants formed abnormal intermolecular disulfide bonds that not only involved the mutant proinsulin, but also the co-expressed WT-proinsulin, forming misfolded disulfide-linked proinsulin complexes. This impaired the intracellular trafficking of WT-proinsulin and limited the production of bioactive mature insulin. Notably, although all three mutants presented with similar defects in folding, trafficking, and dominant negative behavior, the degrees of these defects appeared to be different. Specifically, compared to MODY mutants G(B20)R and P(B28)L that partially affected folding and trafficking of co-expressed WT-proinsulin, the NDM mutant C(A7)Y resulted in an almost complete blockade of the ER export of WT-proinsulin, decreasing insulin production, inducing more severe ER stress and apoptosis. We thus demonstrate that differences in cell biological behaviors among different proinsulin mutants correlate with the spectrum of diabetes phenotypes caused by the different INS gene mutations.
Collapse
Affiliation(s)
- Heting Wang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Cécile Saint-Martin
- Department of Genetics, Sorbonne University, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Jialu Xu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Li Ding
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Ruodan Wang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Wenli Feng
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China; Tianjin Institute of Endocrinology, Tianjin, China
| | - Hua Shu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Zhenqian Fan
- Department of Endocrinology and Metabolism, The Second Hospital of Tianjin Medical University, Tianjin, China
| | - Leena Haataja
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Christine Bellanné-Chantelot
- Department of Genetics, Sorbonne University, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.
| | - Jingqiu Cui
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China.
| | - Yumeng Huang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China.
| |
Collapse
|
22
|
Arneth B. Insulin gene mutations and posttranslational and translocation defects: associations with diabetes. Endocrine 2020; 70:488-497. [PMID: 32656694 DOI: 10.1007/s12020-020-02413-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023]
Abstract
The mechanism underlying the pathogenesis of diabetes is complex and poorly understood. Recent investigations have revealed that insulin gene mutations can lead to the development of specific subtypes of diabetes. This systematic review aimed to explore the associations of insulin gene mutations and insulin translocation defects with diabetes. This review was generated using articles from PsycINFO, PubMed, Web of Science, and CINAHL. Search terms and phrases such as "diabetes," "mutations," "insulin," "preproinsulin," "INS gene," "role," "VNTR polymorphisms," and "INS promotor" were used to identify articles relevant to the research topic. The gathered data showed the significant role of insulin gene mutations and insulin translocation defects during diabetes development and progression. Genetic changes can adversely affect the development of various types of diabetes, such as neonatal diabetes mellitus and MIDY. Genetic alterations can affect insulin production, thus compromising the regulation of glucose utilization by tissues. Targeting insulin gene mutations is a potential new avenue for diagnosing and managing diabetes. There are specific subcategories of diabetes, such as MIDY and neonatal diabetes mellitus, caused by insulin gene mutations and defects in posttranslational modification. Further investigations are needed to examine the diagnostic and therapeutic potential of mutation-based biomarkers.
Collapse
Affiliation(s)
- Borros Arneth
- Institute of Laboratory Medicine and Pathobiochemistry, Molecular Diagnostics, University Hospital of Giessen and Marburg (UKGM), Justus Liebig University Giessen, Feulgenstr 12, 35332, Giessen, Germany.
| |
Collapse
|
23
|
Živná M, Kidd K, Zaidan M, Vyleťal P, Barešová V, Hodaňová K, Sovová J, Hartmannová H, Votruba M, Trešlová H, Jedličková I, Sikora J, Hůlková H, Robins V, Hnízda A, Živný J, Papagregoriou G, Mesnard L, Beck BB, Wenzel A, Tory K, Häeffner K, Wolf MTF, Bleyer ME, Sayer JA, Ong ACM, Balogh L, Jakubowska A, Łaszkiewicz A, Clissold R, Shaw-Smith C, Munshi R, Haws RM, Izzi C, Capelli I, Santostefano M, Graziano C, Scolari F, Sussman A, Trachtman H, Decramer S, Matignon M, Grimbert P, Shoemaker LR, Stavrou C, Abdelwahed M, Belghith N, Sinclair M, Claes K, Kopel T, Moe S, Deltas C, Knebelmann B, Rampoldi L, Kmoch S, Bleyer AJ. An international cohort study of autosomal dominant tubulointerstitial kidney disease due to REN mutations identifies distinct clinical subtypes. Kidney Int 2020; 98:1589-1604. [PMID: 32750457 DOI: 10.1016/j.kint.2020.06.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/09/2020] [Accepted: 06/11/2020] [Indexed: 01/05/2023]
Abstract
There have been few clinical or scientific reports of autosomal dominant tubulointerstitial kidney disease due to REN mutations (ADTKD-REN), limiting characterization. To further study this, we formed an international cohort characterizing 111 individuals from 30 families with both clinical and laboratory findings. Sixty-nine individuals had a REN mutation in the signal peptide region (signal group), 27 in the prosegment (prosegment group), and 15 in the mature renin peptide (mature group). Signal group patients were most severely affected, presenting at a mean age of 19.7 years, with the prosegment group presenting at 22.4 years, and the mature group at 37 years. Anemia was present in childhood in 91% in the signal group, 69% prosegment, and none of the mature group. REN signal peptide mutations reduced hydrophobicity of the signal peptide, which is necessary for recognition and translocation across the endoplasmic reticulum, leading to aberrant delivery of preprorenin into the cytoplasm. REN mutations in the prosegment led to deposition of prorenin and renin in the endoplasmic reticulum-Golgi intermediate compartment and decreased prorenin secretion. Mutations in mature renin led to deposition of the mutant prorenin in the endoplasmic reticulum, similar to patients with ADTKD-UMOD, with a rate of progression to end stage kidney disease (63.6 years) that was significantly slower vs. the signal (53.1 years) and prosegment groups (50.8 years) (significant hazard ratio 0.367). Thus, clinical and laboratory studies revealed subtypes of ADTKD-REN that are pathophysiologically, diagnostically, and clinically distinct.
Collapse
Affiliation(s)
- Martina Živná
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Kendrah Kidd
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic; Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Mohamad Zaidan
- Service de Néphrologie‒Transplantation, Hôpital de Bicêtre, Le Kremlin Bicêtre, France
| | - Petr Vyleťal
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Veronika Barešová
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Kateřina Hodaňová
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jana Sovová
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Hana Hartmannová
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Miroslav Votruba
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Helena Trešlová
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Ivana Jedličková
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jakub Sikora
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Helena Hůlková
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Victoria Robins
- Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Aleš Hnízda
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Jan Živný
- Institute of Pathophysiology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Gregory Papagregoriou
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus, Nicosia, Cyprus
| | - Laurent Mesnard
- Sorbonne Université, Urgences Néphrologiques et Transplantation Rénale, Assistance Publique-Hôpitaux de Paris (APHP), Hôpital Tenon, Paris, France
| | - Bodo B Beck
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Institute of Human Genetics, Cologne, Germany; University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Molecular Medicine Cologne (CMMC) and Center for Rare Diseases Cologneies(ZSEK), Cologne, Germany
| | - Andrea Wenzel
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Institute of Human Genetics, Cologne, Germany; University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Molecular Medicine Cologne (CMMC) and Center for Rare Diseases Cologneies(ZSEK), Cologne, Germany
| | - Kálmán Tory
- MTA-SE Lendület Nephrogenetic Laboratory, Semmelweis University, Budapest, Hungary; First Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Karsten Häeffner
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center, Faculty of Medicine, Universitätsklinikum Freiburg, Freiburg, Germany
| | - Matthias T F Wolf
- Pediatric Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Michael E Bleyer
- Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - John A Sayer
- Renal Services, The Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK; Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; NIHR Newcastle Biomedical Research Centre, Newcastle University, Newcastle upon Tyne, UK
| | - Albert C M Ong
- Kidney Genetics Group, Academic Nephrology Unit, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, UK
| | - Lídia Balogh
- First Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Anna Jakubowska
- Department of Pediatric Nephrology Medical University Wrocław, Poland
| | - Agnieszka Łaszkiewicz
- Laboratory of Molecular and Cellular Immunology, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
| | - Rhian Clissold
- Exeter Kidney Unit, Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, UK
| | - Charles Shaw-Smith
- Exeter Kidney Unit, Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, UK
| | - Raj Munshi
- Division of Nephrology, Department of Pediatrics, Seattle Children's Hospital, University of Washington, Seattle, Washington, USA
| | - Robert M Haws
- Pediatrics-Nephrology, Marshfield Medical Center, Marshfield, Wisconsin, USA
| | - Claudia Izzi
- Division of Nephrology and Dialysis, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia and Montichiari Hospital, Brescia, Italy
| | - Irene Capelli
- Department of Experimental Diagnostic and Specialty Medicine, Nephrology, Dialysis and Renal Transplant Unit, S. Orsola Hospital, University of Bologna, Bologna, Italy
| | | | - Claudio Graziano
- Medical Genetics Unit, Policlinico S. Orsola-Malpighi, Bologna, Italy
| | - Francesco Scolari
- Division of Nephrology and Dialysis, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia and Montichiari Hospital, Brescia, Italy
| | - Amy Sussman
- Department of Medicine, Division of Nephrology, University of Arizona Health Sciences Center, Tucson, Arizona, USA
| | - Howard Trachtman
- Division of Nephrology, Department of Pediatrics, New York University School of Medicine, New York, New York, USA
| | - Stephane Decramer
- Pediatric Nephrology, Centre Hospitalier Universitaire de Toulouse (CHU de Toulouse), Toulouse, France; France Rare Renal Disease Reference Centre (SORARE), Toulouse, France; Centre Hospitalier Universitaire de Toulouse (CHU de Toulouse), Toulouse, France
| | - Marie Matignon
- AP-HP (Assistance Publique-Hôpitaux de Paris), Nephrology and Renal Transplantation Department, Institut Francilien de Recherche en Néphrologie et Transplantation (IFRNT), Groupe Hospitalier Henri-Mondor/Albert-Chenevier, Créteil, France; Université Paris-Est-Créteil, (UPEC), DHU (Département Hospitalo-Universitaire) VIC (Virus-Immunité-Cancer), IMRB (Institut Mondor de Recherche Biomédicale), Equipe 21, INSERM U 955, Créteil, France
| | - Philippe Grimbert
- AP-HP (Assistance Publique-Hôpitaux de Paris), Nephrology and Renal Transplantation Department, Institut Francilien de Recherche en Néphrologie et Transplantation (IFRNT), Groupe Hospitalier Henri-Mondor/Albert-Chenevier, Créteil, France; Université Paris-Est-Créteil, (UPEC), DHU (Département Hospitalo-Universitaire) VIC (Virus-Immunité-Cancer), IMRB (Institut Mondor de Recherche Biomédicale), Equipe 21, INSERM U 955, Créteil, France; AP-HP (Assistance Publique-Hôpitaux de Paris), CIC-BT 504, Créteil, France
| | - Lawrence R Shoemaker
- Division of Nephrology, Department of Pediatrics, University of Florida, Gainesville, Florida, USA
| | | | - Mayssa Abdelwahed
- Laboratory of Human Molecular Genetics, Faculty of Medicine, University of Sfax, Sfax, Tunisia
| | - Neila Belghith
- Laboratory of Human Molecular Genetics, Faculty of Medicine, University of Sfax, Sfax, Tunisia; Medical Genetics Department of Hedi Chaker Hospital, Sfax, Tunisia
| | - Matthew Sinclair
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA; Duke Clinical Research Institute, Durham, North Carolina, USA
| | - Kathleen Claes
- Department of Nephrology and Renal Transplantation, University Hospitals Leuven, Leuven, Belgium; Laboratory of Nephrology, Department of Microbiology and Immunology, Katholieke Universiteit (KU) Leuven, Leuven, Belgium
| | - Tal Kopel
- Nephrology Division, University of Montreal Hospital Centre, Hopital Saint-Luc, Montréal, Québec, Canada
| | - Sharon Moe
- Division of Nephrology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Constantinos Deltas
- Center of Excellence in Biobanking and Biomedical Research, Molecular Medicine Research Center, University of Cyprus, Nicosia, Cyprus
| | - Bertrand Knebelmann
- Department of Nephrology‒Transplantation, Necker Hospital, APHP, Paris, France; Paris Descartes University, Sorbonne Paris Cité, Paris, France; Département Biologie cellulaire, INSERM U1151, Institut Necker Enfants Malades, Paris, France
| | - Luca Rampoldi
- Molecular Genetics of Renal Disorders, Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Stanislav Kmoch
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic; Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Anthony J Bleyer
- Research Unit of Rare Diseases, Department of Pediatric and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic; Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.
| |
Collapse
|
24
|
Cho J, Hiramoto M, Masaike Y, Sakamoto S, Imai Y, Imai Y, Handa H, Imai T. UGGT1 retains proinsulin in the endoplasmic reticulum in an arginine dependent manner. Biochem Biophys Res Commun 2020; 527:668-675. [PMID: 32423812 DOI: 10.1016/j.bbrc.2020.04.158] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 04/30/2020] [Indexed: 12/29/2022]
Abstract
We sought to clarify a pathway by which L- and dD-arginine simulate insulin secretion in mice and cell lines and obtained the following novel two findings. (1) Using affinity magnetic nanobeads technology, we identified that proinsulin is retained in the endoplasmic reticulum (ER) through UDP-glucose:glycoprotein glucosyltransferase 1 (UGGT1) when arginine availability is limited. (2) L- and d-arginine release proinsulin from UGGT1 through competition with proinsulin and promote exit of proinsulin from the ER to Golgi apparatus. The ability of arginine to release proinsulin from UGGT1 closely correlates with arginine-induced insulin secretion in several models of β cells indicating that UGGT1-proinsulin interaction regulates arginine-induced insulin secretion.
Collapse
Affiliation(s)
- Jaeyong Cho
- Department Aging Intervention, National Center for Geriatrics and Gerontology, Obu, Aichi, 474-8511, Japan.
| | - Masaki Hiramoto
- Department Aging Intervention, National Center for Geriatrics and Gerontology, Obu, Aichi, 474-8511, Japan; Department of Biochemistry, Tokyo Medical University, Shinjyuku, Tokyo 160-8402, Japan.
| | - Yuka Masaike
- Department of Nanoparticle Translational Research, Tokyo Medical University, Shinjyuku, Tokyo, 160-8402, Japan.
| | - Satoshi Sakamoto
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Kanagawa, 223-8503, Japan.
| | - Yoichi Imai
- Department of Hematology/Oncology, Research Hospital, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan.
| | - Yumi Imai
- Department of Internal Medicine, Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
| | - Hiroshi Handa
- Department of Nanoparticle Translational Research, Tokyo Medical University, Shinjyuku, Tokyo, 160-8402, Japan.
| | - Takeshi Imai
- Department Aging Intervention, National Center for Geriatrics and Gerontology, Obu, Aichi, 474-8511, Japan.
| |
Collapse
|
25
|
Identification of Ala2Thr mutation in insulin gene from a Chinese MODY10 family. Mol Cell Biochem 2020; 470:77-86. [PMID: 32405973 DOI: 10.1007/s11010-020-03748-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/06/2020] [Indexed: 12/26/2022]
Abstract
More than 80% of maturity-onset diabetes of the young (MODY) in Chinese is genetically unexplained. To investigate whether the insulin gene (INS) mutation is responsible for some Chinese MODY, we screened INS mutations causing MODY10 in MODY pedigrees and explored the potential pathogenic mechanisms. INS mutations were screened in 56 MODY familial probands. Structure-function characterization and clinical profiling of identified INS mutations were conducted. An INS mutation, at the position 2 alanine-to-threonine substitution (A2T), was identified and co-segregated with hyperglycemia in a MODY pedigree. The A2T mutation converted an α-helix into a β-sheet at the N-terminal of the signal peptide (SP) of preproinsulin. The A2T mutation did not affect preproinsulin translocation across endoplasmic reticulum (ER) membrane, but impaired its SP cleavage within the ER. In INS-1 cells transfected with an A2T mutant, glucose-stimulated insulin secretion (GSIS) was significantly decreased, while BiP luciferase activities were significantly increased compared to that of wild type (WT). We identified an INS-A2T mutation cosegregating with diabetes in a Chinese MODY pedigree. This mutation severely impaired SP cleavage and thus blocked the formation of proinsulin, resulting in enhanced ER stress, which may be responsible for decreased insulin secretion and subsequently, the onset of MODY10.
Collapse
|
26
|
Sun J, Xiong Y, Li X, Haataja L, Chen W, Mir SA, Lv L, Madley R, Larkin D, Anjum A, Dhayalan B, Rege N, Wickramasinghe NP, Weiss MA, Itkin-Ansari P, Kaufman RJ, Ostrov DA, Arvan P, Liu M. Role of Proinsulin Self-Association in Mutant INS Gene-Induced Diabetes of Youth. Diabetes 2020; 69:954-964. [PMID: 32139596 PMCID: PMC7171958 DOI: 10.2337/db19-1106] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/22/2020] [Indexed: 02/06/2023]
Abstract
Abnormal interactions between misfolded mutant and wild-type (WT) proinsulin (PI) in the endoplasmic reticulum (ER) drive the molecular pathogenesis of mutant INS gene-induced diabetes of youth (MIDY). How these abnormal interactions are initiated remains unknown. Normally, PI-WT dimerizes in the ER. Here, we suggest that the normal PI-PI contact surface, involving the B-chain, contributes to dominant-negative effects of misfolded MIDY mutants. Specifically, we find that PI B-chain tyrosine-16 (Tyr-B16), which is a key residue in normal PI dimerization, helps confer dominant-negative behavior of MIDY mutant PI-C(A7)Y. Substitutions of Tyr-B16 with either Ala, Asp, or Pro in PI-C(A7)Y decrease the abnormal interactions between the MIDY mutant and PI-WT, rescuing PI-WT export, limiting ER stress, and increasing insulin production in β-cells and human islets. This study reveals the first evidence indicating that noncovalent PI-PI contact initiates dominant-negative behavior of misfolded PI, pointing to a novel therapeutic target to enhance PI-WT export and increase insulin production.
Collapse
Affiliation(s)
- Jinhong Sun
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Yi Xiong
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Xin Li
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Leena Haataja
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Wei Chen
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Saiful A Mir
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | - Li Lv
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Rachel Madley
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Dennis Larkin
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Arfah Anjum
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
| | - Nischay Rege
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH
| | | | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
| | - Pamela Itkin-Ansari
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Randal J Kaufman
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | - David A Ostrov
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Ming Liu
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| |
Collapse
|
27
|
Li X, Itani OA, Haataja L, Dumas KJ, Yang J, Cha J, Flibotte S, Shih HJ, Delaney CE, Xu J, Qi L, Arvan P, Liu M, Hu PJ. Requirement for translocon-associated protein (TRAP) α in insulin biogenesis. SCIENCE ADVANCES 2019; 5:eaax0292. [PMID: 31840061 PMCID: PMC6892615 DOI: 10.1126/sciadv.aax0292] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 10/07/2019] [Indexed: 05/26/2023]
Abstract
The mechanistic basis for the biogenesis of peptide hormones and growth factors is poorly understood. Here, we show that the conserved endoplasmic reticulum membrane translocon-associated protein α (TRAPα), also known as signal sequence receptor 1, plays a critical role in the biosynthesis of insulin. Genetic analysis in the nematode Caenorhabditis elegans and biochemical studies in pancreatic β cells reveal that TRAPα deletion impairs preproinsulin translocation while unexpectedly disrupting distal steps in insulin biogenesis including proinsulin processing and secretion. The association of common intronic single-nucleotide variants in the human TRAPα gene with susceptibility to type 2 diabetes and pancreatic β cell dysfunction suggests that impairment of preproinsulin translocation and proinsulin trafficking may contribute to the pathogenesis of type 2 diabetes.
Collapse
Affiliation(s)
- Xin Li
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Omar A. Itani
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Leena Haataja
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kathleen J. Dumas
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jing Yang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Jeeyeon Cha
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Stephane Flibotte
- Departments of Zoology and Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hung-Jen Shih
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Colin E. Delaney
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jialu Xu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Ling Qi
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Peter Arvan
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Patrick J. Hu
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN, USA
- Division of Hematology and Oncology, Vanderbilt University Medical Center, Nashville, TN, USA
| |
Collapse
|
28
|
Zhu R, Li X, Xu J, Barrabi C, Kekulandara D, Woods J, Chen X, Liu M. Defective endoplasmic reticulum export causes proinsulin misfolding in pancreatic β cells. Mol Cell Endocrinol 2019; 493:110470. [PMID: 31158417 PMCID: PMC6613978 DOI: 10.1016/j.mce.2019.110470] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/30/2019] [Accepted: 05/30/2019] [Indexed: 02/06/2023]
Abstract
Endoplasmic reticulum (ER) homeostasis is essential for cell function. Increasing evidence indicates that, efficient protein ER export is important for ER homeostasis. However, the consequence of impaired ER export remains largely unknown. Herein, we found that defective ER protein transport caused by either Sar1 mutants or brefeldin A impaired proinsulin oxidative folding in the ER of β-cells. Misfolded proinsulin formed aberrant disulfide-linked dimers and high molecular weight proinsulin complexes, and induced ER stress. Limiting proinsulin load to the ER alleviated ER stress, indicating that misfolded proinsulin is a direct cause of ER stress. This study revealed significance of efficient ER export in maintaining ER protein homeostasis and native folding of proinsulin. Given the fact that proinsulin misfolding plays an important role in diabetes, this study suggests that enhancing ER export may be a potential therapeutic target to prevent/delay β-cell failure caused by proinsulin misfolding and ER stress.
Collapse
Affiliation(s)
- Ruimin Zhu
- Department of Physiology, School of Medicine, Wayne State University, Detroit, MI, USA; Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Xin Li
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Jialu Xu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Cesar Barrabi
- Department of Physiology, School of Medicine, Wayne State University, Detroit, MI, USA
| | - Dilini Kekulandara
- Department of Physiology, School of Medicine, Wayne State University, Detroit, MI, USA
| | - James Woods
- Department of Physiology, School of Medicine, Wayne State University, Detroit, MI, USA
| | - Xuequn Chen
- Department of Physiology, School of Medicine, Wayne State University, Detroit, MI, USA.
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China.
| |
Collapse
|
29
|
Liu S, Li X, Yang J, Zhu R, Fan Z, Xu X, Feng W, Cui J, Sun J, Liu M. Misfolded proinsulin impairs processing of precursor of insulin receptor and insulin signaling in β cells. FASEB J 2019; 33:11338-11348. [PMID: 31311313 PMCID: PMC6766638 DOI: 10.1096/fj.201900442r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Insulin resistance in classic insulin-responsive tissues is a hallmark of type 2 diabetes (T2D). However, the pathologic significance of β-cell insulin resistance and the underlying mechanisms contributing to defective insulin signaling in β cells remain largely unknown. Emerging evidence indicates that proinsulin misfolding is not only the molecular basis of mutant INS-gene–induced diabetes of youth (MIDY) but also an important contributor in the development and progression of T2D. However, the molecular basis of β-cell failure caused by misfolded proinsulin is still incompletely understood. Herein, using Akita mice expressing diabetes-causing mutant proinsulin, we found that misfolded proinsulin abnormally interacted with the precursor of insulin receptor (ProIR) in the endoplasmic reticulum (ER), impaired ProIR maturation to insulin receptor (IR), and decreased insulin signaling in β cells. Importantly, using db/db insulin-resistant mice, we found that oversynthesis of proinsulin led to an increased proinsulin misfolding, which resulted in impairments of ProIR processing and insulin signaling in β cells. These results reveal for the first time that misfolded proinsulin can interact with ProIR in the ER, impairing intracellular processing of ProIR and leading to defective insulin signaling that may contribute to β-cell failure in both MIDY and T2D.—Liu, S., Li, X., Yang, J., Zhu, R., Fan, Z., Xu, X., Feng, W., Cui, J., Sun, J., Liu, M. Misfolded proinsulin impairs processing of precursor of insulin receptor and insulin signaling in β cells.
Collapse
Affiliation(s)
- Shiqun Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Xin Li
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Jing Yang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Ruimin Zhu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Zhenqian Fan
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Xiaoxi Xu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Wenli Feng
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Jingqiu Cui
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Jinhong Sun
- Department of Health Management, Tianjin Medical University General Hospital, Tianjin, China
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| |
Collapse
|
30
|
Ghiasi SM, Dahlby T, Hede Andersen C, Haataja L, Petersen S, Omar-Hmeadi M, Yang M, Pihl C, Bresson SE, Khilji MS, Klindt K, Cheta O, Perone MJ, Tyrberg B, Prats C, Barg S, Tengholm A, Arvan P, Mandrup-Poulsen T, Marzec MT. Endoplasmic Reticulum Chaperone Glucose-Regulated Protein 94 Is Essential for Proinsulin Handling. Diabetes 2019; 68:747-760. [PMID: 30670477 PMCID: PMC6425875 DOI: 10.2337/db18-0671] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 12/26/2018] [Indexed: 12/18/2022]
Abstract
Although endoplasmic reticulum (ER) chaperone binding to mutant proinsulin has been reported, the role of protein chaperones in the handling of wild-type proinsulin is underinvestigated. Here, we have explored the importance of glucose-regulated protein 94 (GRP94), a prominent ER chaperone known to fold insulin-like growth factors, in proinsulin handling within β-cells. We found that GRP94 coimmunoprecipitated with proinsulin and that inhibition of GRP94 function and/or expression reduced glucose-dependent insulin secretion, shortened proinsulin half-life, and lowered intracellular proinsulin and insulin levels. This phenotype was accompanied by post-ER proinsulin misprocessing and higher numbers of enlarged insulin granules that contained amorphic material with reduced immunogold staining for mature insulin. Insulin granule exocytosis was accelerated twofold, but the secreted insulin had diminished bioactivity. Moreover, GRP94 knockdown or knockout in β-cells selectively activated protein kinase R-like endoplasmic reticulum kinase (PERK), without increasing apoptosis levels. Finally, GRP94 mRNA was overexpressed in islets from patients with type 2 diabetes. We conclude that GRP94 is a chaperone crucial for proinsulin handling and insulin secretion.
Collapse
Affiliation(s)
- Seyed Mojtaba Ghiasi
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tina Dahlby
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Leena Haataja
- Division of Metabolism, Endocrinology, & Diabetes, University of Michigan Medical Center, Ann Arbor, MI
| | - Sólrun Petersen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Mingyu Yang
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Celina Pihl
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Muhammad Saad Khilji
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kristian Klindt
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Oana Cheta
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marcelo J Perone
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society, Polo Científico Tecnológico, Buenos Aires, Argentina
| | - Björn Tyrberg
- Translational Science, Cardiovascular, Renal and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Clara Prats
- Center for Healthy Ageing, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sebastian Barg
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Peter Arvan
- Division of Metabolism, Endocrinology, & Diabetes, University of Michigan Medical Center, Ann Arbor, MI
| | | | - Michal Tomasz Marzec
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
31
|
Liu M, Weiss MA, Arunagiri A, Yong J, Rege N, Sun J, Haataja L, Kaufman RJ, Arvan P. Biosynthesis, structure, and folding of the insulin precursor protein. Diabetes Obes Metab 2018; 20 Suppl 2:28-50. [PMID: 30230185 PMCID: PMC6463291 DOI: 10.1111/dom.13378] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/04/2018] [Accepted: 05/23/2018] [Indexed: 02/06/2023]
Abstract
Insulin synthesis in pancreatic β-cells is initiated as preproinsulin. Prevailing glucose concentrations, which oscillate pre- and postprandially, exert major dynamic variation in preproinsulin biosynthesis. Accompanying upregulated translation of the insulin precursor includes elements of the endoplasmic reticulum (ER) translocation apparatus linked to successful orientation of the signal peptide, translocation and signal peptide cleavage of preproinsulin-all of which are necessary to initiate the pathway of proper proinsulin folding. Evolutionary pressures on the primary structure of proinsulin itself have preserved the efficiency of folding ("foldability"), and remarkably, these evolutionary pressures are distinct from those protecting the ultimate biological activity of insulin. Proinsulin foldability is manifest in the ER, in which the local environment is designed to assist in the overall load of proinsulin folding and to favour its disulphide bond formation (while limiting misfolding), all of which is closely tuned to ER stress response pathways that have complex (beneficial, as well as potentially damaging) effects on pancreatic β-cells. Proinsulin misfolding may occur as a consequence of exuberant proinsulin biosynthetic load in the ER, proinsulin coding sequence mutations, or genetic predispositions that lead to an altered ER folding environment. Proinsulin misfolding is a phenotype that is very much linked to deficient insulin production and diabetes, as is seen in a variety of contexts: rodent models bearing proinsulin-misfolding mutants, human patients with Mutant INS-gene-induced Diabetes of Youth (MIDY), animal models and human patients bearing mutations in critical ER resident proteins, and, quite possibly, in more common variety type 2 diabetes.
Collapse
Affiliation(s)
- Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China 300052
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor 48105 MI USA
| | - Michael A. Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis 46202 IN USA
- Department of Biochemistry, Case-Western Reserve University, Cleveland 44016 OH USA
| | - Anoop Arunagiri
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor 48105 MI USA
| | - Jing Yong
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92307 USA
| | - Nischay Rege
- Department of Biochemistry, Case-Western Reserve University, Cleveland 44016 OH USA
| | - Jinhong Sun
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China 300052
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor 48105 MI USA
| | - Leena Haataja
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor 48105 MI USA
| | - Randal J. Kaufman
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92307 USA
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor 48105 MI USA
| |
Collapse
|
32
|
Zhou J, Zhu P, Hu X, Lu H, Yu Y. Improved secretory expression of lignocellulolytic enzymes in Kluyveromyces marxianus by promoter and signal sequence engineering. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:235. [PMID: 30279722 PMCID: PMC6116501 DOI: 10.1186/s13068-018-1232-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/20/2018] [Indexed: 06/05/2023]
Abstract
BACKGROUND Taking into account its thermotolerance, high growth rate, and broad substrate spectrum, Kluyveromyces marxianus can be considered an ideal consolidated bioprocessing (CBP). A major obstacle to ethanol production using K. marxianus is the low production of lignocellulolytic enzymes, which reduces the cellulose hydrolysis and ethanol production. Thus, further improvement of enzyme expression and secretion is essential. RESULTS To improve the expression of lignocellulolytic enzymes, the inulinase promoter and signal sequence from K. marxianus was optimized through mutagenesis. A T(-361)A mutation inside the promoter, a deletion of AT-rich region inside 5'UTR (UTR∆A), and a P10L substitution in the signal sequence increased the secretory expression of the feruloyl esterase Est1E by up to sixfold. T(-361)A and UTR∆A increased the mRNA expression, while the P10L substitution extended the hydrophobic core of signal sequence and promoted secretion of mature protein. P10L and T(-361)A mutations increased secretory expressions of other types of lignocellulolytic enzymes by up to threefold, including endo-1,4-β-glucanase RuCelA, endo-1,4-β-endoxylanase Xyn-CDBFV, and endo-1,4-β-mannanase MAN330. During the fed-batch fermentation of strains carrying optimized modules, the peak activities of RuCelA, Xyn-CDBFV, MAN330, and Est1E reached 24 U/mL, 25,600 U/mL, 10,200 U/mL, and 1220 U/mL, respectively. Importantly, higher yield of enzymes by optimized promoter and signal sequence were achieved in all tested carbon sources, including the major end products of lignocellulose saccharification and fermentation, with growth on xylose resulting in the highest production. CONCLUSIONS The engineered promoter and signal sequence presented increased secretory expressions of different lignocellulolytic enzymes in K. marxianus by means of various carbon resources. Activities of lignocellulolytic enzymes in fed-batch fermentation were the highest activities reported for K. marxianus so far. Our engineered modules are valuable in producing lignocellulolytic enzymes by K. marxianus and in constructing efficient CBP strains for cellulosic ethanol production.
Collapse
Affiliation(s)
- Jungang Zhou
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
- Shanghai Engineering Research Center of Industrial Microorganisms, Shanghai, 200438 China
| | - Peixia Zhu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
- Shanghai Engineering Research Center of Industrial Microorganisms, Shanghai, 200438 China
| | - Xiaoyue Hu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
- Shanghai Engineering Research Center of Industrial Microorganisms, Shanghai, 200438 China
| | - Hong Lu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
- Shanghai Engineering Research Center of Industrial Microorganisms, Shanghai, 200438 China
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai, 200237 China
| | - Yao Yu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
- Shanghai Engineering Research Center of Industrial Microorganisms, Shanghai, 200438 China
| |
Collapse
|
33
|
Millership SJ, Da Silva Xavier G, Choudhury AI, Bertazzo S, Chabosseau P, Pedroni SM, Irvine EE, Montoya A, Faull P, Taylor WR, Kerr-Conte J, Pattou F, Ferrer J, Christian M, John RM, Latreille M, Liu M, Rutter GA, Scott J, Withers DJ. Neuronatin regulates pancreatic β cell insulin content and secretion. J Clin Invest 2018; 128:3369-3381. [PMID: 29864031 PMCID: PMC6063487 DOI: 10.1172/jci120115] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 05/17/2018] [Indexed: 02/06/2023] Open
Abstract
Neuronatin (Nnat) is an imprinted gene implicated in human obesity and widely expressed in neuroendocrine and metabolic tissues in a hormone- and nutrient-sensitive manner. However, its molecular and cellular functions and precise role in organismal physiology remain only partly defined. Here we demonstrate that mice lacking Nnat globally or specifically in β cells display impaired glucose-stimulated insulin secretion leading to defective glucose handling under conditions of nutrient excess. In contrast, we report no evidence for any feeding or body weight phenotypes in global Nnat-null mice. At the molecular level neuronatin augments insulin signal peptide cleavage by binding to the signal peptidase complex and facilitates translocation of the nascent preprohormone. Loss of neuronatin expression in β cells therefore reduces insulin content and blunts glucose-stimulated insulin secretion. Nnat expression, in turn, is glucose-regulated. This mechanism therefore represents a novel site of nutrient-sensitive control of β cell function and whole-animal glucose homeostasis. These data also suggest a potential wider role for Nnat in the regulation of metabolism through the modulation of peptide processing events.
Collapse
Affiliation(s)
- Steven J. Millership
- MRC London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Gabriela Da Silva Xavier
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | | | - Sergio Bertazzo
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Pauline Chabosseau
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - Silvia M.A. Pedroni
- MRC London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Elaine E. Irvine
- MRC London Institute of Medical Sciences, London, United Kingdom
| | - Alex Montoya
- MRC London Institute of Medical Sciences, London, United Kingdom
| | - Peter Faull
- MRC London Institute of Medical Sciences, London, United Kingdom
| | - William R. Taylor
- Computational Cell and Molecular Biology Laboratory, Francis Crick Institute, London, United Kingdom
| | - Julie Kerr-Conte
- European Genomic Institute for Diabetes, UMR 1190 Translational Research for Diabetes, INSERM, CHU Lille, University of Lille, Lille, France
| | - Francois Pattou
- European Genomic Institute for Diabetes, UMR 1190 Translational Research for Diabetes, INSERM, CHU Lille, University of Lille, Lille, France
| | - Jorge Ferrer
- Beta Cell Genome Regulation Laboratory, Department of Medicine, Imperial College London, London, United Kingdom
| | - Mark Christian
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Rosalind M. John
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | | | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Guy A. Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - James Scott
- National Heart and Lung Institute, Department of Medicine, Imperial College London, London, United Kingdom
| | - Dominic J. Withers
- MRC London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| |
Collapse
|
34
|
Neelankal John A, Jiang FX. An overview of type 2 diabetes and importance of vitamin D3-vitamin D receptor interaction in pancreatic β-cells. J Diabetes Complications 2018; 32:429-443. [PMID: 29422234 DOI: 10.1016/j.jdiacomp.2017.12.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 12/03/2017] [Accepted: 12/07/2017] [Indexed: 02/07/2023]
Abstract
One significant health issue that plagues contemporary society is that of Type 2 diabetes (T2D). This disease is characterised by higher-than-average blood glucose levels as a result of a combination of insulin resistance and insufficient insulin secretions from the β-cells of pancreatic islets of Langerhans. Previous developmental research into the pancreas has identified how early precursor genes of pancreatic β-cells, such as Cpal, Ngn3, NeuroD, Ptf1a, and cMyc, play an essential role in the differentiation of these cells. Furthermore, β-cell molecular characterization has also revealed the specific role of β-cell-markers, such as Glut2, MafA, Ins1, Ins2, and Pdx1 in insulin expression. The expression of these genes appears to be suppressed in the T2D β-cells, along with the reappearance of the early endocrine marker genes. Glucose transporters transport glucose into β-cells, thereby controlling insulin release during hyperglycaemia. This stimulates glycolysis through rises in intracellular calcium (a process enhanced by vitamin D) (Norman et al., 1980), activating 2 of 4 proteinases. The rise in calcium activates half of pancreatic β-cell proinsulinases, thus releasing free insulin from granules. The synthesis of ATP from glucose by glycolysis, Krebs cycle and oxidative phosphorylation plays a role in insulin release. Some studies have found that the β-cells contain high levels of the vitamin D receptor; however, the role that this plays in maintaining the maturity of the β-cells remains unknown. Further research is required to develop a more in-depth understanding of the role VDR plays in β-cell function and the processes by which the beta cell function is preserved.
Collapse
Affiliation(s)
- Abraham Neelankal John
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia; School of Medicine and Pharmacology, University of Western Australia, Carwley, Western Australia, Australia
| | - Fang-Xu Jiang
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia; School of Medicine and Pharmacology, University of Western Australia, Carwley, Western Australia, Australia.
| |
Collapse
|
35
|
Lindert U, Gnoli M, Maioli M, Bedeschi MF, Sangiorgi L, Rohrbach M, Giunta C. Insight into the Pathology of a COL1A1 Signal Peptide Heterozygous Mutation Leading to Severe Osteogenesis Imperfecta. Calcif Tissue Int 2018; 102:373-379. [PMID: 29101475 PMCID: PMC5818590 DOI: 10.1007/s00223-017-0359-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 10/30/2017] [Indexed: 12/22/2022]
Abstract
Osteogenesis imperfecta or "brittle bone disease" is a congenital disorder of connective tissue causing the bone to break easily. Around 85-90% of cases are due to autosomal dominant mutations in the genes encoding type I collagen, the major organic component of bone. Genotype-phenotype correlations have shown that quantitative defects of collagen type I lead to mild OI, whereas structural defects show a wide clinical range from mild to perinatal lethal. This may partially be explained by the type of amino acid substitution and the relative location in the domain structure. To fully understand the variability of the clinical manifestation and the underlying pathomechanisms, further investigations are required. Here we provide the first biochemical characterization of a mutation at the signal peptide cleavage site of COL1A1, a domain not yet characterized. By steady-state analysis, we observed reduced production of collagen type I. Furthermore, by pulse-chase analysis we detected delayed secretion and partial intracellular retention of collagen I. In the cellular fraction, the electrophoretic migration was abnormal; however, secreted type I collagen showed a normal migration pattern. The intracellular retention of collagen I was confirmed by immunofluorescent staining. Moreover, transmission electron microscopy of cultured fibroblasts revealed enlargement of ER cisternae. These results further support the hypothesis that mechanisms interfering with ER integrity play an important role in the pathology of severe OI.
Collapse
Affiliation(s)
- U Lindert
- Connective Tissue Unit, Division of Metabolism and Children's Research Center, University Children's Hospital, Steinwiesstrasse 75, 8032, Zurich, Switzerland
| | - M Gnoli
- Department of Medical Genetics and Skeletal Rare Diseases, Rizzoli Orthopaedic Institute, Bologna, Italy
| | - M Maioli
- Department of Medical Genetics and Skeletal Rare Diseases, Rizzoli Orthopaedic Institute, Bologna, Italy
| | - M F Bedeschi
- Medical Genetics Unit, Fondazione IRCCS Ca'Granda Ospedale Maggiore Policlinico, Milano, Italy
| | - L Sangiorgi
- Department of Medical Genetics and Skeletal Rare Diseases, Rizzoli Orthopaedic Institute, Bologna, Italy
| | - M Rohrbach
- Connective Tissue Unit, Division of Metabolism and Children's Research Center, University Children's Hospital, Steinwiesstrasse 75, 8032, Zurich, Switzerland
| | - C Giunta
- Connective Tissue Unit, Division of Metabolism and Children's Research Center, University Children's Hospital, Steinwiesstrasse 75, 8032, Zurich, Switzerland.
| |
Collapse
|
36
|
Ushijima K, Fukami M, Ayabe T, Narumi S, Okuno M, Nakamura A, Takahashi T, Ihara K, Ohkubo K, Tachikawa E, Nakayama S, Arai J, Kikuchi N, Kikuchi T, Kawamura T, Urakami T, Hata K, Nakabayashi K, Matsubara Y, Amemiya S, Ogata T, Yokota I, Sugihara S. Comprehensive screening for monogenic diabetes in 89 Japanese children with insulin-requiring antibody-negative type 1 diabetes. Pediatr Diabetes 2018; 19:243-250. [PMID: 28597946 DOI: 10.1111/pedi.12544] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 04/03/2017] [Accepted: 05/02/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Mutations in causative genes for neonatal diabetes or maturity-onset diabetes of the young have been identified in multiple patients with autoantibody-negative type 1 diabetes (T1D). OBJECTIVES We aimed to clarify the prevalence and phenotypic characteristics of monogenic abnormalities among 89 children with autoantibody-negative insulin-requiring T1D. METHODS Mutations in 30 genes were screened using next-generation sequencing, and copy-number alterations of 4 major causative genes were examined using multiplex-ligation-dependent probe amplification. We compared the clinical characteristics between mutation carriers and non-carriers. RESULTS We identified 11 probable pathogenic substitutions (6 in INS , 2 in HNF1A , 2 in HNF4A , and 1 in HNF1B ) in 11 cases, but no copy-number abnormalities. Only 2 mutation carriers had affected parents. De novo occurrence was confirmed for 3 mutations. The non-carrier group, but not the carrier group, was enriched with susceptible HLA alleles. Mutation carriers exhibited comparable phenotypes to those of non-carriers, except for a relatively normal body mass index (BMI) at diagnosis. CONCLUSIONS This study demonstrated significant genetic overlap between autoantibody-negative T1D and monogenic diabetes. Mutations in INS and HNF genes, but not those in GCK and other monogenic diabetes genes, likely play critical roles in children with insulin-requiring T1D. This study also suggests the relatively high de novo rates of INS and HNF mutations, and the etiological link between autoimmune abnormalities and T1D in the non-carrier group. Carriers of monogenic mutations show non-specific phenotypes among all T1D cases, although they are more likely to have a normal BMI at diagnosis than non-carriers.
Collapse
Affiliation(s)
- Kikumi Ushijima
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Maki Fukami
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Tadayuki Ayabe
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan.,Department of Pediatrics, Sanaikai General Hospital, Misato, Japan
| | - Satoshi Narumi
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Misako Okuno
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan.,Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan
| | - Akie Nakamura
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
| | | | - Kenji Ihara
- Department of Pediatrics, Oita University School of Medicine, Oita, Japan
| | - Kazuhiro Ohkubo
- Department of Pediatrics, Kyushu University School of Medicine, Fukuoka, Japan
| | - Emiko Tachikawa
- Department of Pediatrics, Tokyo Women's Medical University Hospital, Tokyo, Japan
| | - Shoji Nakayama
- Department of Pediatrics, Mominoki Hospital, Kochi, Japan
| | - Junichi Arai
- Department of Pediatrics, Hosogi Hospital, Kochi, Japan
| | - Nobuyuki Kikuchi
- Department of Pediatrics, Yokohama City Minato Red Cross Hospital, Yokohama, Japan
| | - Toru Kikuchi
- Department of Pediatrics, Saitama Medical University Faculty of Medicine, Saitama, Japan
| | - Tomoyuki Kawamura
- Department of Pediatrics, Osaka City University School of Medicine, Osaka, Japan
| | - Tatsuhiko Urakami
- Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan
| | - Kenichiro Hata
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Kazuhiko Nakabayashi
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Yoichi Matsubara
- Institute Director, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Shin Amemiya
- Department of Pediatrics, Saitama Medical University Faculty of Medicine, Saitama, Japan
| | - Tsutomu Ogata
- Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Ichiro Yokota
- Department of Pediatrics, Division of Pediatric Endocrinology and Metabolism, Shikoku Medical Center for Children and Adults, Kagawa, Japan
| | - Shigetaka Sugihara
- Department of Pediatrics, Tokyo Women's Medical University Medical Center East, Tokyo, Japan
| | | |
Collapse
|
37
|
Guo H, Sun J, Li X, Xiong Y, Wang H, Shu H, Zhu R, Liu Q, Huang Y, Madley R, Wang Y, Cui J, Arvan P, Liu M. Positive charge in the n-region of the signal peptide contributes to efficient post-translational translocation of small secretory preproteins. J Biol Chem 2017; 293:1899-1907. [PMID: 29229776 DOI: 10.1074/jbc.ra117.000922] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 11/30/2017] [Indexed: 12/17/2022] Open
Abstract
Increasing evidence indicates that many small secretory preproteins can undergo post-translational translocation across the membrane of the endoplasmic reticulum. Although the cellular machinery involved in post-translational translocation of small secretory preproteins has begun to be elucidated, the intrinsic signals contained within these small secretory preproteins that contribute to their efficient post-translational translocation remain unknown. Here, we analyzed the eukaryotic secretory proteome and discovered the small secretory preproteins tend to have a higher probability to harbor the positive charge in the n-region of the signal peptide (SP). Eliminating the positive charge of the n-region blocked post-translational translocation of newly synthesized preproteins and selectively impaired translocation efficiency of small secretory preproteins. The pathophysiological significance of the positive charge in the n-region of SP was underscored by recently identified preproinsulin SP mutations that impair translocation of preproinsulin and cause maturity onset diabetes of youth (MODY). Remarkably, we have found that slowing the polypeptide elongation rate of small secretory preproteins could alleviate the translocation defect caused by loss of the n-region positive charge of the signal peptide. Together, these data reveal not only a previously unrecognized role of the n-region's positive charge in ensuring efficient post-translational translocation of small secretory preproteins, but they also highlight the molecular contribution of defects in this process to the pathogenesis of genetic disorders such as MODY.
Collapse
Affiliation(s)
- Huan Guo
- From the Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China.,the Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105, and
| | - Jinhong Sun
- From the Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China.,the Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105, and
| | - Xin Li
- From the Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Yi Xiong
- the Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105, and
| | - Heting Wang
- From the Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Hua Shu
- From the Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Ruimin Zhu
- From the Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Qi Liu
- From the Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Yumeng Huang
- From the Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Rachel Madley
- the Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105, and
| | - Yulun Wang
- the Division of Endocrinology, Tianjin People's Hospital, Tianjin 300120, China
| | - Jingqiu Cui
- From the Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Peter Arvan
- the Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105, and
| | - Ming Liu
- From the Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China, .,the Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105, and
| |
Collapse
|
38
|
Demirtas L, Guclu A, Erdur FM, Akbas EM, Ozcicek A, Onk D, Turkmen K. Apoptosis, autophagy & endoplasmic reticulum stress in diabetes mellitus. Indian J Med Res 2017; 144:515-524. [PMID: 28256459 PMCID: PMC5345297 DOI: 10.4103/0971-5916.200887] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The prevalence of diabetes mellitus (DM) is increasing secondary to increased consumption of food and decreased physical activity worldwide. Hyperglycaemia, insulin resistance and hypertrophy of pancreatic beta cells occur in the early phase of diabetes. However, with the progression of diabetes, dysfunction and loss of beta cells occur in both types 1 and 2 DM. Programmed cell death also named apoptosis is found to be associated with diabetes, and apoptosis of beta cells might be the main mechanism of relative insulin deficiency in DM. Autophagic cell death and apoptosis are not entirely distinct programmed cell death mechanisms and share many of the regulator proteins. These processes can occur in both physiologic and pathologic conditions including DM. Besides these two important pathways, endoplasmic reticulum (ER) also acts as a cell sensor to monitor and maintain cellular homeostasis. ER stress has been found to be associated with autophagy and apoptosis. This review was aimed to describe the interactions between apoptosis, autophagy and ER stress pathways in DM.
Collapse
Affiliation(s)
- Levent Demirtas
- Department of Internal Medicine, Erzincan University, Erzincan, Turkey
| | - Aydin Guclu
- Division of Nephrology, Kırsehir Training and Research Hospital, Kırsehir, Turkey
| | - Fatih Mehmet Erdur
- Department of Internal Medicine, Necmettin Erbakan University, Meram School of Medicine, Konya, Turkey
| | - Emin Murat Akbas
- Department of Internal Medicine, Erzincan University, Erzincan, Turkey
| | - Adalet Ozcicek
- Department of Internal Medicine, Erzincan University, Erzincan, Turkey
| | - Didem Onk
- Department of Reanimation & Anesthesiology, Erzincan University, Erzincan, Turkey
| | - Kultigin Turkmen
- Department of Internal Medicine, Necmettin Erbakan University, Meram School of Medicine, Konya, Turkey
| |
Collapse
|
39
|
Haataja L, Manickam N, Soliman A, Tsai B, Liu M, Arvan P. Disulfide Mispairing During Proinsulin Folding in the Endoplasmic Reticulum. Diabetes 2016; 65:1050-60. [PMID: 26822090 PMCID: PMC4806660 DOI: 10.2337/db15-1345] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 01/14/2016] [Indexed: 02/06/2023]
Abstract
Proinsulin folding within the endoplasmic reticulum (ER) remains incompletely understood, but it is clear that in mutant INS gene-induced diabetes of youth (MIDY), progression of the (three) native disulfide bonds of proinsulin becomes derailed, causing insulin deficiency, β-cell ER stress, and onset of diabetes. Herein, we have undertaken a molecular dissection of proinsulin disulfide bond formation, using bioengineered proinsulins that can form only two (or even only one) of the native proinsulin disulfide bonds. In the absence of preexisting proinsulin disulfide pairing, Cys(B19)-Cys(A20) (a major determinant of ER stress response activation and proinsulin stability) preferentially initiates B-A chain disulfide bond formation, whereas Cys(B7)-Cys(A7) can initiate only under oxidizing conditions beyond that existing within the ER of β-cells. Interestingly, formation of these two "interchain" disulfide bonds demonstrates cooperativity, and together, they are sufficient to confer intracellular transport competence to proinsulin. The three most common proinsulin disulfide mispairings in the ER appear to involve Cys(A11)-Cys(A20), Cys(A7)-Cys(A20), and Cys(B19)-Cys(A11), each disrupting the critical Cys(B19)-Cys(A20) pairing. MIDY mutations inhibit Cys(B19)-Cys(A20) formation, but treatment to force oxidation of this disulfide bond improves folding and results in a small but detectable increase of proinsulin export. These data suggest possible therapeutic avenues to ameliorate ER stress and diabetes.
Collapse
Affiliation(s)
- Leena Haataja
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, MI
| | - Nandini Manickam
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, MI
| | - Ann Soliman
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, MI
| | - Billy Tsai
- Department of Cell & Developmental Biology, University of Michigan Medical Center, Ann Arbor, MI
| | - Ming Liu
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, MI Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, MI
| |
Collapse
|
40
|
Cui J, Chen W, Sun J, Guo H, Madley R, Xiong Y, Pan X, Wang H, Tai AW, Weiss MA, Arvan P, Liu M. Competitive Inhibition of the Endoplasmic Reticulum Signal Peptidase by Non-cleavable Mutant Preprotein Cargos. J Biol Chem 2015; 290:28131-28140. [PMID: 26446786 DOI: 10.1074/jbc.m115.692350] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 12/30/2022] Open
Abstract
Upon translocation across the endoplasmic reticulum (ER) membrane, secretory proteins are proteolytically processed to remove their signal peptide by signal peptidase (SPase). This process is critical for subsequent folding, intracellular trafficking, and maturation of secretory proteins. Prokaryotic SPase has been shown to be a promising antibiotic target. In contrast, to date, no eukaryotic SPase inhibitors have been reported. Here we report that introducing a proline immediately following the natural signal peptide cleavage site not only blocks preprotein cleavage but also, in trans, impairs the processing and maturation of co-expressed preproteins in the ER. Specifically, we find that a variant preproinsulin, pPI-F25P, is translocated across the ER membrane, where it binds to the catalytic SPase subunit SEC11A, inhibiting SPase activity in a dose-dependent manner. Similar findings were obtained with an analogous variant of preproparathyroid hormone, demonstrating that inhibition of the SPase does not depend strictly on the sequence or structure of the downstream mature protein. We further show that inhibiting SPase in the ER impairs intracellular processing of viral polypeptides and their subsequent maturation. These observations suggest that eukaryotic SPases (including the human ortholog) are, in principle, suitable therapeutic targets for antiviral drug design.
Collapse
Affiliation(s)
- Jingqiu Cui
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China,; Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Wei Chen
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105,; Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Jinhong Sun
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Huan Guo
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Rachel Madley
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Yi Xiong
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Xingyi Pan
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Hongliang Wang
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Andrew W Tai
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Michael A Weiss
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106.
| | - Peter Arvan
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China,; Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| |
Collapse
|
41
|
He K, Cunningham CN, Manickam N, Liu M, Arvan P, Tsai B. PDI reductase acts on Akita mutant proinsulin to initiate retrotranslocation along the Hrd1/Sel1L-p97 axis. Mol Biol Cell 2015; 26:3413-23. [PMID: 26269577 PMCID: PMC4591687 DOI: 10.1091/mbc.e15-01-0034] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 08/05/2015] [Indexed: 02/06/2023] Open
Abstract
Protein disulfide isomerase acts as a reductase to reduce a mutant proinsulin called Akita, priming it for retrotranslocation across the endoplasmic reticulum (ER) membrane by using the Sel1L-Hrd1-p97 ER-associated degradation machinery. In mutant INS gene–induced diabetes of youth (MIDY), characterized by insulin deficiency, MIDY proinsulin mutants misfold and fail to exit the endoplasmic reticulum (ER). Moreover, these mutants bind and block ER exit of wild-type (WT) proinsulin, inhibiting insulin production. The ultimate fate of ER-entrapped MIDY mutants is unclear, but previous studies implicated ER-associated degradation (ERAD), a pathway that retrotranslocates misfolded ER proteins to the cytosol for proteasomal degradation. Here we establish key ERAD machinery components used to triage the Akita proinsulin mutant, including the Hrd1-Sel1L membrane complex, which conducts Akita proinsulin from the ER lumen to the cytosol, and the p97 ATPase, which couples the cytosolic arrival of proinsulin with its proteasomal degradation. Surprisingly, we find that protein disulfide isomerase (PDI), the major protein oxidase of the ER lumen, engages Akita proinsulin in a novel way, reducing proinsulin disulfide bonds and priming the Akita protein for ERAD. Efficient PDI engagement of Akita proinsulin appears linked to the availability of Hrd1, suggesting that retrotranslocation is coordinated on the lumenal side of the ER membrane. We believe that, in principle, this form of diabetes could be alleviated by enhancing the targeting of MIDY mutants for ERAD to restore WT insulin production.
Collapse
Affiliation(s)
- Kaiyu He
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Corey Nathaniel Cunningham
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109 Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Nandini Manickam
- Division of Metabolism Endocrinology and Diabetes, Comprehensive Diabetes Center, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Ming Liu
- Division of Metabolism Endocrinology and Diabetes, Comprehensive Diabetes Center, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Peter Arvan
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI 48109 Division of Metabolism Endocrinology and Diabetes, Comprehensive Diabetes Center, University of Michigan Medical School, Ann Arbor, MI 48109 ) )
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109 Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI 48109 ) )
| |
Collapse
|
42
|
Sun J, Cui J, He Q, Chen Z, Arvan P, Liu M. Proinsulin misfolding and endoplasmic reticulum stress during the development and progression of diabetes. Mol Aspects Med 2015; 42:105-18. [PMID: 25579745 PMCID: PMC4404191 DOI: 10.1016/j.mam.2015.01.001] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 12/31/2014] [Accepted: 01/02/2015] [Indexed: 02/06/2023]
Abstract
To maintain copious insulin granule stores in the face of ongoing metabolic demand, pancreatic beta cells must produce large quantities of proinsulin, the insulin precursor. Proinsulin biosynthesis can account for up to 30-50% of total cellular protein synthesis of beta cells. This puts pressure on the beta cell secretory pathway, especially the endoplasmic reticulum (ER), where proinsulin undergoes its initial folding, including the formation of three evolutionarily conserved disulfide bonds. In normal beta cells, up to 20% of newly synthesized proinsulin may fail to reach its native conformation, suggesting that proinsulin is a misfolding-prone protein. Misfolded proinsulin molecules can either be refolded to their native structure or degraded through ER associated degradation (ERAD) and autophagy. These degraded molecules decrease proinsulin yield but do not otherwise compromise beta cell function. However, under certain pathological conditions, proinsulin misfolding increases, exceeding the genetically determined threshold of beta cells to handle the misfolded protein load. This results in accumulation of misfolded proinsulin in the ER - a causal factor leading to beta cell failure and diabetes. In patients with Mutant INS-gene induced diabetes of Youth (MIDY), increased proinsulin misfolding due to insulin gene mutations is the primary defect operating as a "first hit" to beta cells. Additionally, increased proinsulin misfolding can be secondary to an unfavorable ER folding environment due to genetic and/or environmental factors. Under these conditions, increased wild-type proinsulin misfolding becomes a "second hit" to the ER and beta cells, aggravating beta cell failure and diabetes. In this article, we describe our current understanding of the normal proinsulin folding pathway in the ER, and then review existing links between proinsulin misfolding, ER dysfunction, and beta cell failure in the development and progression of type 2, type 1, and some monogenic forms of diabetes.
Collapse
Affiliation(s)
- Jinhong Sun
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI 48105, USA
| | - Jingqiu Cui
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Qing He
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Zheng Chen
- School of Life Sciences, Northeast Normal University, Changchun, Jilin 130024, China
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI 48105, USA.
| | - Ming Liu
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI 48105, USA; Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300052, China.
| |
Collapse
|
43
|
Dusatkova L, Dusatkova P, Vosahlo J, Vesela K, Cinek O, Lebl J, Pruhova S. Frameshift mutations in the insulin gene leading to prolonged molecule of insulin in two families with Maturity-Onset Diabetes of the Young. Eur J Med Genet 2015; 58:230-4. [PMID: 25721872 DOI: 10.1016/j.ejmg.2015.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 02/12/2015] [Indexed: 02/06/2023]
Abstract
Mutations in the insulin (INS) gene rarely occur in patients with Maturity-Onset Diabetes of the Young (MODY). We aimed to describe in detail two MODY families with INS mutations. The INS gene was screened by direct sequencing. The probands and their affected relatives underwent a mixed-meal test. Mutation predictions were modeled using I-TASSER and were visualized by Swiss-PdbViewer. A novel heterozygous frameshift mutation p.Gln78fs in the INS gene was found in three generations of patients with clinically distinct diabetes. The single nucleotide deletion (c.233delA) is predicted to change and prolong amino acid sequence, resulting in aberrant proinsulin without native structures of C-peptide and A-chain. In the second family, the heterozygous mutation c.188-31G>A within the terminal intron was detected. The mother and her daughter were misdiagnosed as having type 1 diabetes since the ages of 6 and 2 years, respectively. This result is in contrast to the previously described carrier of the same mutation who was diagnosed with permanent neonatal diabetes. We identified a novel coding frameshift mutation and an intronic mutation in the INS gene leading to childhood-onset diabetes. INS mutations may result in various phenotypes, suggesting that additional mechanisms may be involved in the pathogenesis and clinical manifestation of diabetes.
Collapse
Affiliation(s)
- Lenka Dusatkova
- Department of Pediatrics, Charles University in Prague, 2nd Faculty of Medicine and University Hospital Motol, Prague, CZ-150 06, Czech Republic
| | - Petra Dusatkova
- Department of Pediatrics, Charles University in Prague, 2nd Faculty of Medicine and University Hospital Motol, Prague, CZ-150 06, Czech Republic.
| | - Jan Vosahlo
- Department of Pediatrics, Charles University in Prague, 3rd Faculty of Medicine and University Hospital Kralovske Vinohrady, Prague, CZ-100 34, Czech Republic
| | - Klara Vesela
- Department of Pediatrics, Charles University in Prague, 2nd Faculty of Medicine and University Hospital Motol, Prague, CZ-150 06, Czech Republic
| | - Ondrej Cinek
- Department of Pediatrics, Charles University in Prague, 2nd Faculty of Medicine and University Hospital Motol, Prague, CZ-150 06, Czech Republic
| | - Jan Lebl
- Department of Pediatrics, Charles University in Prague, 2nd Faculty of Medicine and University Hospital Motol, Prague, CZ-150 06, Czech Republic
| | - Stepanka Pruhova
- Department of Pediatrics, Charles University in Prague, 2nd Faculty of Medicine and University Hospital Motol, Prague, CZ-150 06, Czech Republic
| |
Collapse
|
44
|
Liu M, Sun J, Cui J, Chen W, Guo H, Barbetti F, Arvan P. INS-gene mutations: from genetics and beta cell biology to clinical disease. Mol Aspects Med 2014; 42:3-18. [PMID: 25542748 DOI: 10.1016/j.mam.2014.12.001] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 12/02/2014] [Accepted: 12/04/2014] [Indexed: 02/06/2023]
Abstract
A growing list of insulin gene mutations causing a new form of monogenic diabetes has drawn increasing attention over the past seven years. The mutations have been identified in the untranslated regions of the insulin gene as well as the coding sequence of preproinsulin including within the signal peptide, insulin B-chain, C-peptide, insulin A-chain, and the proteolytic cleavage sites both for signal peptidase and the prohormone convertases. These mutations affect a variety of different steps of insulin biosynthesis in pancreatic beta cells. Importantly, although many of these mutations cause proinsulin misfolding with early onset autosomal dominant diabetes, some of the mutant alleles appear to engage different cellular and molecular mechanisms that underlie beta cell failure and diabetes. In this article, we review the most recent advances in the field and discuss challenges as well as potential strategies to prevent/delay the development and progression of autosomal dominant diabetes caused by INS-gene mutations. It is worth noting that although diabetes caused by INS gene mutations is rare, increasing evidence suggests that defects in the pathway of insulin biosynthesis may also be involved in the progression of more common types of diabetes. Collectively, the (pre)proinsulin mutants provide insightful molecular models to better understand the pathogenesis of all forms of diabetes in which preproinsulin processing defects, proinsulin misfolding, and ER stress are involved.
Collapse
Affiliation(s)
- Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, 300052, China; Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI, 48105, USA.
| | - Jinhong Sun
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Jinqiu Cui
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Wei Chen
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Huan Guo
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Fabrizio Barbetti
- Department of Experimental Medicine, University of Tor Vergata, Rome and Bambino Gesù Children's Hospital, Rome, Italy
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI, 48105, USA.
| |
Collapse
|
45
|
Ksenofontova OI. [Introduction of mutations in insulin molecule: positive and negative mutations]. BIOMEDIT︠S︡INSKAI︠A︡ KHIMII︠A︡ 2014; 60:430-7. [PMID: 25249526 DOI: 10.18097/pbmc20146004430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Introduction of mutations in an insulin molecule is one of the important approaches to drug development for treatment of diabetes mellitus. Generally, usage of mutations is aimed at activation of insulin and insulin receptor interaction. Such mutations can be considered as positive. Mutations that reduce the binding efficacy are negative. There are neutral mutations as well. This article considers both natural mutations that are typical for various members of the insulin superfamily and artificial ones which are introduced to improve the insulin pharmacological characteristics. Data presented here can be useful in developing new effective insulin analogues for treatment of diabetes mellitus.
Collapse
|
46
|
Abstract
Proteins and peptides are well-documented as useful marker adjuncts to cardiovascular clinical decision-making. Most markers measured derive from a defined, stable proprotein region of their respective gene. However, a neglected portion of preproproteins known as the signal peptide (SP) is also present in the circulation and may also present as a measurable marker. SPs were assumed to be degraded intracellularly after directing secretion, but a small, growing body of evidence is identifying SPs as not being degraded within and without cells. In this article, evidence for the persistence of SPs after translation is presented and their role as potential cardiovascular biomarkers is discussed.
Collapse
|
47
|
Kim J, Cheon H, Jeong YT, Quan W, Kim KH, Cho JM, Lim YM, Oh SH, Jin SM, Kim JH, Lee MK, Kim S, Komatsu M, Kang SW, Lee MS. Amyloidogenic peptide oligomer accumulation in autophagy-deficient β cells induces diabetes. J Clin Invest 2014; 124:3311-24. [PMID: 25036705 DOI: 10.1172/jci69625] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 05/29/2014] [Indexed: 02/06/2023] Open
Abstract
Islet amyloid accumulation is a hallmark of human type 2 diabetes (T2D). In contrast to human islet amyloid polypeptide (hIAPP), murine islet amyloid polypeptide (mIAPP) does not exhibit amyloidogenic propensity. Because autophagy is important in the clearance of amyloid-like proteins, we studied transgenic mice with β cell-specific expression of hIAPP to evaluate the contribution of autophagy in T2D-associated accumulation of hIAPP. In mice with β cell-specific expression of hIAPP, a deficiency in autophagy resulted in development of overt diabetes, which was not observed in mice expressing hIAPP alone or lacking autophagy alone. Furthermore, lack of autophagy in hIAPP-expressing animals resulted in hIAPP oligomer and amyloid accumulation in pancreatic islets, leading to increased death and decreased mass of β cells. Expression of hIAPP in purified monkey islet cells or a murine β cell line resulted in pro-hIAPP dimer formation, while dimer formation was absent or reduced dramatically in cells expressing either nonamyloidogenic mIAPP or nonfibrillar mutant hIAPP. In autophagy-deficient cells, accumulation of pro-hIAPP dimers increased markedly, and pro-hIAPP trimers were detected in the detergent-insoluble fraction. Enhancement of autophagy improved the metabolic profile of hIAPP-expressing mice fed a high-fat diet. These results suggest that autophagy promotes clearance of amyloidogenic hIAPP, autophagy deficiency exacerbates pathogenesis of human T2D, and autophagy enhancers have therapeutic potential for islet amyloid accumulation-associated human T2D.
Collapse
|
48
|
Guo H, Xiong Y, Witkowski P, Cui J, Wang LJ, Sun J, Lara-Lemus R, Haataja L, Hutchison K, Shan SO, Arvan P, Liu M. Inefficient translocation of preproinsulin contributes to pancreatic β cell failure and late-onset diabetes. J Biol Chem 2014; 289:16290-302. [PMID: 24770419 DOI: 10.1074/jbc.m114.562355] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Among the defects in the early events of insulin biosynthesis, proinsulin misfolding and endoplasmic reticulum (ER) stress have drawn increasing attention as causes of β cell failure. However, no studies have yet addressed potential defects at the cytosolic entry point of preproinsulin into the secretory pathway. Here, we provide the first evidence that inefficient translocation of preproinsulin (caused by loss of a positive charge in the n region of its signal sequence) contributes to β cell failure and diabetes. Specifically, we find that, after targeting to the ER membrane, preproinsulin signal peptide (SP) mutants associated with autosomal dominant late-onset diabetes fail to be fully translocated across the ER membrane. The newly synthesized, untranslocated preproinsulin remains strongly associated with the ER membrane, exposing its proinsulin moiety to the cytosol. Rather than accumulating in the ER and inducing ER stress, untranslocated preproinsulin accumulates in a juxtanuclear compartment distinct from the Golgi complex, induces the expression of heat shock protein 70 (HSP70), and promotes β cell death. Restoring an N-terminal positive charge to the mutant preproinsulin SP significantly improves the translocation defect. These findings not only reveal a novel molecular pathogenesis of β cell failure and diabetes but also provide the first evidence of the physiological and pathological significance of the SP n region positive charge of secretory proteins.
Collapse
Affiliation(s)
- Huan Guo
- From the Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Yi Xiong
- From the Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Piotr Witkowski
- the Division of Organ Transplantation, University of Chicago, Chicago, Illinois 60637
| | - Jingqing Cui
- From the Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105, the Division of Metabolism, Tianjin Medical University General Hospital, Tianjin, China 300052
| | - Ling-jia Wang
- the Division of Organ Transplantation, University of Chicago, Chicago, Illinois 60637
| | - Jinhong Sun
- From the Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Roberto Lara-Lemus
- From the Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105, the Department of Research in Biochemistry, National Institute of Respiratory Diseases "Ismael Cosío Villegas", Mexico City 14080, Mexico, and
| | - Leena Haataja
- From the Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Kathryn Hutchison
- From the Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Shu-ou Shan
- the Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Peter Arvan
- From the Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105,
| | - Ming Liu
- From the Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105, the Division of Metabolism, Tianjin Medical University General Hospital, Tianjin, China 300052,
| |
Collapse
|
49
|
Setyowati Karolina D, Sepramaniam S, Tan HZ, Armugam A, Jeyaseelan K. miR-25 and miR-92a regulate insulin I biosynthesis in rats. RNA Biol 2014; 10:1365-78. [PMID: 24084692 DOI: 10.4161/rna.25557] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The 3' UTR of insulin has been identified as a critical region that confers mRNA stability, which is crucial for promoting transcription in response to glucose challenge. miRNAs are endogenously encoded non-coding RNAs that function as regulators of gene expression. This regulatory function is generally mediated by complementary binding to the 3'UTR of its mRNA targets that affects subsequent translational process. Genes involved in the regulation of glucose homeostasis, particularly in insulin production, have been found as targets of several miRNAs. Yet, no direct miRNA-based regulators of insulin biosynthesis have been identified. In this study, identification of possible miRNA-based regulators of insulin production is explored. Members of a miRNA family, miR-25 and miR-92a, are found as direct modulators of insulin expression. Overexpression of miR-25 or miR-92a reduced insulin expression while inhibition of miR-25 and miR-92a expression using corresponding antagomiRs promoted insulin expression and ultimately enhanced glucose-induced insulin secretion. Furthermore, suppression of insulin secretion by pre miR-9 could be attenuated by treatment with anti-miR-25 or miR-92a. Interestingly, we found the binding site of miR-25 and miR-92a to overlap with that of PTBP1, an important RNA binding molecule that stabilizes insulin mRNA for translation. Despite the increase in PTBP1 protein in the pancreas of diabetic rats, we observed insulin expression to be reduced alongside upregulation of miR-25 and miR-92a, suggesting an intricate regulation of insulin (bio)synthesis at its mRNA level.
Collapse
Affiliation(s)
- Dwi Setyowati Karolina
- Department of Biochemistry; Yong Loo Lin School of Medicine; National University Health System; Singapore
| | | | | | | | | |
Collapse
|
50
|
Hara T, Mahadevan J, Kanekura K, Hara M, Lu S, Urano F. Calcium efflux from the endoplasmic reticulum leads to β-cell death. Endocrinology 2014; 155:758-68. [PMID: 24424032 PMCID: PMC3929724 DOI: 10.1210/en.2013-1519] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
It has been established that intracellular calcium homeostasis is critical for survival and function of pancreatic β-cells. However, the role of endoplasmic reticulum (ER) calcium homeostasis in β-cell survival and death is not clear. Here we show that ER calcium depletion plays a critical role in β-cell death. Various pathological conditions associated with β-cell death, including ER stress, oxidative stress, palmitate, and chronic high glucose, decreased ER calcium levels and sarcoendoplasmic reticulum Ca(2+)-ATPase 2b expression, leading to β-cell death. Ectopic expression of mutant insulin and genetic ablation of WFS1, a causative gene for Wolfram syndrome, also decreased ER calcium levels and induced β-cell death. Hyperactivation of calpain-2, a calcium-dependent proapoptotic protease, was detected in β-cells undergoing ER calcium depletion. Ectopic expression of sarcoendoplasmic reticulum Ca(2+)-ATPase 2b, as well as pioglitazone and rapamycin treatment, could prevent calcium efflux from the ER and mitigate β-cell death under various stress conditions. Our results reveal a critical role of ER calcium depletion in β-cell death and indicate that identification of pathways and chemical compounds restoring ER calcium levels will lead to novel therapeutic modalities and pharmacological interventions for type 1 and type 2 diabetes and other ER-related diseases including Wolfram syndrome.
Collapse
Affiliation(s)
- Takashi Hara
- Department of Medicine (T.H., J.M., K.K., M.H., S.L., F.U.), Division of Endocrinology, Metabolism, and Lipid Research, and Department of Pathology and Immunology (F.U.), Washington University School of Medicine, St Louis, Missouri 63110; and Cardiovascular-Metabolics Research Laboratories (T.H.), Daiichi Sankyo Co, Ltd, Tokyo 103-8426, Japan
| | | | | | | | | | | |
Collapse
|