1
|
Ng NHJ, Ghosh S, Bok CM, Ching C, Low BSJ, Chen JT, Lim E, Miserendino MC, Tan YS, Hoon S, Teo AKK. HNF4A and HNF1A exhibit tissue specific target gene regulation in pancreatic beta cells and hepatocytes. Nat Commun 2024; 15:4288. [PMID: 38909044 PMCID: PMC11193738 DOI: 10.1038/s41467-024-48647-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/08/2024] [Indexed: 06/24/2024] Open
Abstract
HNF4A and HNF1A encode transcription factors that are important for the development and function of the pancreas and liver. Mutations in both genes have been directly linked to Maturity Onset Diabetes of the Young (MODY) and type 2 diabetes (T2D) risk. To better define the pleiotropic gene regulatory roles of HNF4A and HNF1A, we generated a comprehensive genome-wide map of their binding targets in pancreatic and hepatic cells using ChIP-Seq. HNF4A was found to bind and regulate known (ACY3, HAAO, HNF1A, MAP3K11) and previously unidentified (ABCD3, CDKN2AIP, USH1C, VIL1) loci in a tissue-dependent manner. Functional follow-up highlighted a potential role for HAAO and USH1C as regulators of beta cell function. Unlike the loss-of-function HNF4A/MODY1 variant I271fs, the T2D-associated HNF4A variant (rs1800961) was found to activate AKAP1, GAD2 and HOPX gene expression, potentially due to changes in DNA-binding affinity. We also found HNF1A to bind to and regulate GPR39 expression in beta cells. Overall, our studies provide a rich resource for uncovering downstream molecular targets of HNF4A and HNF1A that may contribute to beta cell or hepatic cell (dys)function, and set up a framework for gene discovery and functional validation.
Collapse
Affiliation(s)
- Natasha Hui Jin Ng
- Stem Cells and Diabetes Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, 138673, Singapore
| | - Soumita Ghosh
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore
| | - Chek Mei Bok
- Stem Cells and Diabetes Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, 138673, Singapore
| | - Carmen Ching
- Stem Cells and Diabetes Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, 138673, Singapore
| | - Blaise Su Jun Low
- Stem Cells and Diabetes Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, 138673, Singapore
| | - Juin Ting Chen
- Stem Cells and Diabetes Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, 138673, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore
- Department of Biochemistry, National University of Singapore, Singapore, 117596, Singapore
| | - Euodia Lim
- Stem Cells and Diabetes Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, 138673, Singapore
- Department of Biochemistry, National University of Singapore, Singapore, 117596, Singapore
| | - María Clara Miserendino
- Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA, Córdoba, Argentina
- Bioinformatics Institute, A*STAR, Singapore, 138671, Singapore
| | - Yaw Sing Tan
- Bioinformatics Institute, A*STAR, Singapore, 138671, Singapore
| | - Shawn Hoon
- Molecular Engineering Laboratory, IMCB, A*STAR, Singapore, 138673, Singapore
| | - Adrian Kee Keong Teo
- Stem Cells and Diabetes Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, 138673, Singapore.
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore.
- Department of Biochemistry, National University of Singapore, Singapore, 117596, Singapore.
- Precision Medicine Translational Research Programme (TRP), National University of Singapore, Singapore, 119228, Singapore.
| |
Collapse
|
2
|
Paganos P, Ronchi P, Carl J, Mizzon G, Martinez P, Benvenuto G, Arnone MI. Integrating single cell transcriptomics and volume electron microscopy confirms the presence of pancreatic acinar-like cells in sea urchins. Front Cell Dev Biol 2022; 10:991664. [PMID: 36060803 PMCID: PMC9437490 DOI: 10.3389/fcell.2022.991664] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 07/21/2022] [Indexed: 01/11/2023] Open
Abstract
The identity and function of a given cell type relies on the differential expression of gene batteries that promote diverse phenotypes and functional specificities. Therefore, the identification of the molecular and morphological fingerprints of cell types across taxa is essential for untangling their evolution. Here we use a multidisciplinary approach to identify the molecular and morphological features of an exocrine, pancreas-like cell type harbored within the sea urchin larval gut. Using single cell transcriptomics, we identify various cell populations with a pancreatic-like molecular fingerprint that are enriched within the S. purpuratus larva digestive tract. Among these, in the region where they reside, the midgut/stomach domain, we find that populations of exocrine pancreas-like cells have a unique regulatory wiring distinct from the rest the of the cell types of the same region. Furthermore, Serial Block-face scanning Electron Microscopy (SBEM) of the exocrine cells shows that this reported molecular diversity is associated to distinct morphological features that reflect the physiological and functional properties of this cell type. Therefore, we propose that these sea urchin exocrine cells are homologous to the well-known mammalian pancreatic acinar cells and thus we trace the origin of this particular cell type to the time of deuterostome diversification. Overall, our approach allows a thorough characterization of a complex cell type and shows how both the transcriptomic and morphological information contribute to disentangling the evolution of cell types and organs such as the pancreatic cells and pancreas.
Collapse
Affiliation(s)
| | - Paolo Ronchi
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Jil Carl
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Giulia Mizzon
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Pedro Martinez
- Institut Català de Recerca i Estudis Avancats (ICREA), Barcelona, Spain,Genetics Department, University of Barcelona, Barcelona, Spain
| | | | - Maria Ina Arnone
- Stazione Zoologica Anton Dohrn (SZN), Naples, Italy,*Correspondence: Maria Ina Arnone,
| |
Collapse
|
3
|
Barth R, Ruoso C, Ferreira SM, de Ramos FC, Lima FB, Boschero AC, Santos GJD. Hepatocyte Nuclear Factor 4-α (HNF4α) controls the insulin resistance-induced pancreatic β-cell mass expansion. Life Sci 2022; 289:120213. [PMID: 34902439 DOI: 10.1016/j.lfs.2021.120213] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/17/2021] [Accepted: 12/01/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND Regardless of the etiology, any type of DM presents a reduction of insulin-secreting cell mass, so it is important to investigate pathways that induce the increase of this cell mass. AIM Based on the fact that (1) HNF4α is crucial for β-cell proliferation, (2) DEX-induced IR promotes β-cell mass expansion, and (3) the stimulation of β-cell mass expansion may be an important target for DM therapies, we aimed to investigate whether DEX-induced proliferation of β pancreatic cells is dependent on HNF4α. METHODS We used WildType (WT) and Knockout (KO) mice for HNF4-α, treated or not with 100 mg/Kg/day of DEX, for 5 consecutive days. One day after the last injection of DEX the IR was confirmed by ipITT and the mice were euthanized for pancreas removal. RESULTS In comparison to WT, KO mice presented increased glucose tolerance, lower fasting glucose and increased glucose-stimulates insulin secretion (GSIS). DEX induced IR in both KO and WT mice. In addition, DEX-induced β-cell mass expansion and an increase in the Ki67 immunostaining were observed only in WT mice, evidencing that IR-induced β-cell mass expansion is dependent on HNF4α. Also, we observed that DEX-treatment, in an HNF4α-dependent way, promoted an increase in PDX1, PAX4 and NGN3 gene expression. CONCLUSIONS Our results strongly suggest that DEX-induced IR promotes β-cell mass expansion through processes of proliferation and neogenesis that depend on the HNF4α activity, pointing to HNF4α as a possible therapeutic target in DM treatment.
Collapse
Affiliation(s)
- Robson Barth
- Islet Biology and Metabolism Lab - I.B.M. Lab, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis 88040-900, Santa Catarina, Brazil; Multicenter Graduate Program in Physiological Sciences, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil
| | - Carolina Ruoso
- Islet Biology and Metabolism Lab - I.B.M. Lab, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis 88040-900, Santa Catarina, Brazil; Multicenter Graduate Program in Physiological Sciences, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil
| | - Sandra Mara Ferreira
- Laboratory of endocrine pancreas and metabolism - LAPEM, Department of Structural and Functional Biology, Institute of Biology, State University of Campinas - UNICAMP, 13083-862 Campinas, Brazil
| | - Francieli Caroline de Ramos
- Islet Biology and Metabolism Lab - I.B.M. Lab, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis 88040-900, Santa Catarina, Brazil; Multicenter Graduate Program in Physiological Sciences, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil
| | - Fernanda Barbosa Lima
- Islet Biology and Metabolism Lab - I.B.M. Lab, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis 88040-900, Santa Catarina, Brazil; Multicenter Graduate Program in Physiological Sciences, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil
| | - Antônio Carlos Boschero
- Laboratory of endocrine pancreas and metabolism - LAPEM, Department of Structural and Functional Biology, Institute of Biology, State University of Campinas - UNICAMP, 13083-862 Campinas, Brazil
| | - Gustavo Jorge Dos Santos
- Islet Biology and Metabolism Lab - I.B.M. Lab, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis 88040-900, Santa Catarina, Brazil; Multicenter Graduate Program in Physiological Sciences, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil.
| |
Collapse
|
4
|
Wang Z, Zhang Y, Zhang J, Deng Q, Liang H. Controversial roles of hepatocyte nuclear receptor 4 α on tumorigenesis. Oncol Lett 2021; 21:356. [PMID: 33747213 PMCID: PMC7968000 DOI: 10.3892/ol.2021.12617] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 02/09/2021] [Indexed: 02/06/2023] Open
Abstract
Hepatocyte nuclear receptor 4 α (HNF4α) is known to be a master transcription regulator of gene expression in multiple biological processes, particularly in liver development and liver function. To date, the function of HNF4α in human cancers has been widely investigated; however, the critical roles of HNF4α in tumorigenesis remain unclear. Numerous controversies exist, even in studies from different research groups but on the same type of cancer. In the present review, the critical roles of HNF4α in tumorigenesis will be summarized and discussed. Furthermore, HNF4α expression profile and alterations will be examined by pan-cancer analysis through bioinformatics, in order to provide a better understanding of the functional roles of this gene in human cancers.
Collapse
Affiliation(s)
- Zhu Wang
- Department of Urology, People's Hospital of Longhua, Southern Medical University, Shenzhen, Guangdong 518109, P.R. China
| | - Ying Zhang
- Department of Urology, People's Hospital of Longhua, Southern Medical University, Shenzhen, Guangdong 518109, P.R. China
| | - Jianwen Zhang
- Department of Urology, People's Hospital of Longhua, Southern Medical University, Shenzhen, Guangdong 518109, P.R. China
| | - Qiong Deng
- Department of Urology, People's Hospital of Longhua, Southern Medical University, Shenzhen, Guangdong 518109, P.R. China
| | - Hui Liang
- Department of Urology, People's Hospital of Longhua, Southern Medical University, Shenzhen, Guangdong 518109, P.R. China
| |
Collapse
|
5
|
Jhawat V, Gulia M, Gupta S, Maddiboyina B, Dutt R. Integration of pharmacogenomics and theranostics with nanotechnology as quality by design (QbD) approach for formulation development of novel dosage forms for effective drug therapy. J Control Release 2020; 327:500-511. [PMID: 32858073 DOI: 10.1016/j.jconrel.2020.08.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 12/12/2022]
Abstract
To cater to medication needs in the future healthcare system, we need to shift from the conventional system of drug delivery to modern molecular signature-based drug delivery systems. The current drug therapies are either less effective, ineffective, or produce numerous adverse reactions. One scientific principle or discipline cannot adequately address all the problems, so we need an innovative application of the current scientific principles. Here we are proposing a novel concept of nanoformulation based on pharmacogenomics and theranostics for personalized error-free and targeted therapeutic agent delivery. The addition of more knowledge about the human genome opens the new way to study disease-gene, gene-drug, and drug-effect interactions, which is the basis of future medicines. Pharmacogenomics provides information about the disease etiology, role in genes in disease pathophysiology, disease biomarkers, drug targets, drug effects, and the fate of drugs inside the body. Theranostics approach utilizes the above information in diagnosis, treatment, and monitoring of the disease on a real-time basis. Personalized dosage forms can be formulated into a nanoformulation that provides a better therapeutic effect and minimizes adverse drug reactions. The therapeutic system needs to be shifted from the principle of one drug fits all to one drug unique population. In the present manuscript, we tried to conceptualize a modern therapeutic system by combining the three approaches viz. pharmacogenomics, theranostics, and nanotechnology applied in the area of formulation development to produce a multifunctional single tiny entity.
Collapse
Affiliation(s)
- Vikas Jhawat
- Department of Pharmaceutical Sciences, School of Medical and Allied Sciences, GD Goenka University, Gurugram, Haryana, India.
| | - Monika Gulia
- Department of Pharmaceutical Sciences, School of Medical and Allied Sciences, GD Goenka University, Gurugram, Haryana, India
| | - Sumeet Gupta
- Department of Pharmaceutical Sciences, Maharishi Markandeshwar (Deemed to be) University, Mullana, Ambala, Haryana, India
| | - Balaji Maddiboyina
- Department of Pharmaceutical Sciences, Vishwa Bharathi College of Pharmaceutical Sciences, Guntur, A.P, India
| | - Rohit Dutt
- Department of Pharmaceutical Sciences, School of Medical and Allied Sciences, GD Goenka University, Gurugram, Haryana, India
| |
Collapse
|
6
|
Krivtsova O, Makarova A, Lazarevich N. Aberrant expression of alternative isoforms of transcription factors in hepatocellular carcinoma. World J Hepatol 2018; 10:645-661. [PMID: 30386458 PMCID: PMC6206146 DOI: 10.4254/wjh.v10.i10.645] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/08/2018] [Accepted: 06/28/2018] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide and the second leading cause of death among all cancer types. Deregulation of the networks of tissue-specific transcription factors (TFs) observed in HCC leads to profound changes in the hepatic transcriptional program that facilitates tumor progression. In addition, recent reports suggest that substantial aberrations in the production of TF isoforms occur in HCC. In vitro experiments have identified distinct isoform-specific regulatory functions and related biological effects of liver-specific TFs that are implicated in carcinogenesis, which may be relevant for tumor progression and clinical outcome. This study reviews available data on the expression of isoforms of liver-specific and ubiquitous TFs in the liver and HCC and their effects, including HNF4α, C/EBPs, p73 and TCF7L2, and indicates that assessment of the ratio of isoforms and targeting specific TF variants may be beneficial for the prognosis and treatment of HCC.
Collapse
Affiliation(s)
- Olga Krivtsova
- Federal State Budgetary Institution, “N. N. Blokhin Medical Research Center of Oncology” of the Ministry of Health of the Russian Federation, Moscow 115478, Russian
- M. V. Lomonosov Moscow State University, Moscow 119991, Russian
| | - Anna Makarova
- Federal State Budgetary Institution, “N. N. Blokhin Medical Research Center of Oncology” of the Ministry of Health of the Russian Federation, Moscow 115478, Russian
| | - Natalia Lazarevich
- Federal State Budgetary Institution, “N. N. Blokhin Medical Research Center of Oncology” of the Ministry of Health of the Russian Federation, Moscow 115478, Russian
- M. V. Lomonosov Moscow State University, Moscow 119991, Russian
| |
Collapse
|
7
|
Kang YBA, Rawat S, Cirillo J, Bouchard M, Noh HM. Layered long-term co-culture of hepatocytes and endothelial cells on a transwell membrane: toward engineering the liver sinusoid. Biofabrication 2013; 5:045008. [PMID: 24280542 DOI: 10.1088/1758-5082/5/4/045008] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This paper presents a novel liver model that mimics the liver sinusoid where most liver activities occur. A key aspect of our current liver model is a layered co-culture of primary rat hepatocytes (PRHs) and primary rat liver sinusoidal endothelial cells (LSECs) or bovine aortic endothelial cells (BAECs) on a transwell membrane. When a layered co-culture was attempted with a thin Matrigel layer placed between hepatocytes and endothelial cells to mimic the space of Disse, the cells did not form completely separated monolayers. However, when hepatocytes and endothelial cells were cultured on the opposite sides of a transwell membrane, PRHs co-cultured with LSECs or BAECs maintained their viability and normal morphology for 39 and 57 days, respectively. We assessed the presence of hepatocyte-specific differentiation markers to verify that PRHs remained differentiated in the long-term co-culture and analyzed hepatocyte function by monitoring urea synthesis. We also noted that the expression of cytochrome P-450 remained similar in the co-cultured system from day 1 to day 48. Thus, our novel liver model system demonstrated that primary hepatocytes can be cultured for extended times and retain their hepatocyte-specific functions when layered with endothelial cells.
Collapse
|
8
|
Harries LW. Messenger RNA processing and its role in diabetes. Diabet Med 2011; 28:1010-7. [PMID: 21699562 DOI: 10.1111/j.1464-5491.2011.03373.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The past few years have seen huge advances in our understanding of the genetics of diabetes. However, definition of the mechanisms that underpin these observations is less clear. It is now becoming apparent that the processes that mediate these effects are complex and interlinked, and will require consideration of other factors in addition to the DNA sequence. The information in our genes is conveyed to the cellular machinery via an intermediate molecule, RNA. However, we now understand that RNA is not merely a messenger, as RNA-based mechanisms are responsible for a large proportion of the fine-tuning of gene expression and gene regulation. The initial RNA transcript produced undergoes a series of modifications known as RNA processing to generate a mature messenger RNA (mRNA). This includes addition of the 5' cap sequences and the poly-A tail of the mRNA molecule, and removal of its intronic sequences. The exact pattern of mRNA processing may vary from cell type to cell type and differ in response to internal and external stimuli. In this review, using examples from my own work, I will outline how mRNA processing mechanisms can sometimes provide a mode of action for mutations causing monogenic diabetes, and also suggest potential explanations for phenotypic variation in this condition. The potential for mRNA processing to impact on more complex causes of diabetes as well will also be considered.
Collapse
Affiliation(s)
- L W Harries
- Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, UK.
| |
Collapse
|
9
|
Hellwege JN, Hicks PJ, Palmer ND, Ng MCY, Freedman BI, Bowden DW. Examination of Rare Variants in HNF4 α in European Americans with Type 2 Diabetes. ACTA ACUST UNITED AC 2011; 2. [PMID: 23227446 DOI: 10.4172/2155-6156.1000145] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The hepatocyte nuclear factor 4-α (HNF4α) gene codes for a transcription factor which is responsible for regulating gene transcription in pancreatic beta cells, in addition to its primary role in hepatic gene regulation. Mutations in this gene can lead to maturity-onset diabetes of the young (MODY), an uncommon, autosomal dominant, non-insulin dependent form of diabetes. Mutations in HNF4α have been found in few individuals, and infrequently have they segregated completely with MODY in families. In addition, due to similarity of phenotypes, it is unclear what proportion of type 2 diabetes (T2DM) in the general population is due to MODY or HNF4α mutations specifically. In this study, 27 documented rare and common variants were genotyped in a European American population of 1270 T2DM cases and 1017 controls from review of databases and literature implicating HNF4α variants in MODY and T2DM. Seventeen variants were found to be monomorphic. Two cases and one control subject had one copy of a 6-bp P2 promoter deletion. The intron 1 variant (rs6103716; MAF = 0.31) was not significantly associated with disease status (p>0.8) and the missense variant Thr130Ile (rs1800961; MAF = 0.027) was also not significantly different between cases and controls (p>0.2), but showed a trend consistent with association with T2DM. Four variants were found to be rare as heterozygotes in small numbers of subjects. Since many variants were infrequent, a pooled chi-squared analysis of rare variants was used to assess the overall burden of variants between cases and controls. This analysis revealed no significant difference (P=0.22). We conclude there is little evidence to suggest that HNF4α variants contribute significantly to risk of T2DM in the general population, but a modest contribution cannot be excluded. In addition, the observation of some mutations in controls suggests they are not highly penetrant MODY-causing variants.
Collapse
Affiliation(s)
- Jacklyn N Hellwege
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA ; Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA ; Program in Molecular Genetics and Genomics, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | | | | | | | | | | |
Collapse
|
10
|
Donelan W, Koya V, Li SW, Yang LJ. Distinct regulation of hepatic nuclear factor 1alpha by NKX6.1 in pancreatic beta cells. J Biol Chem 2010; 285:12181-9. [PMID: 20106981 PMCID: PMC2852957 DOI: 10.1074/jbc.m109.064238] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 01/19/2010] [Indexed: 01/12/2023] Open
Abstract
Hepatic nuclear factor 1alpha (HNF1alpha) is a key regulator of development and function in pancreatic beta cells and is specifically involved in regulation of glycolysis and glucose-stimulated insulin secretion. Abnormal expression of HNF1alpha leads to development of MODY3 (maturity-onset diabetes of the young 3). We report that NK6 homeodomain 1 (NKX6.1) binds to a cis-regulatory element in the HNF1alpha promoter and is a major regulator of this gene in beta cells. We identified an NKX6.1 recognition sequence in the distal region of the HNF1alpha promoter and demonstrated specific binding of NKX6.1 in beta cells by electrophoretic mobility shift and chromatin immunoprecipitation assays. Site-directed mutagenesis of the NKX6.1 core-binding sequence eliminated NKX6.1-mediated activation and substantially decreased activity of the HNF1alpha promoter in beta cells. Overexpression or small interfering RNA-mediated knockdown of the Nkx6.1 gene resulted in increased or diminished HNF1alpha gene expression, respectively, in beta cells. We conclude that NKX6.1 is a novel regulator of HNF1alpha in pancreatic beta cells. This novel regulatory mechanism for HNF1alpha in beta cells may provide new molecular targets for the diagnosis of MODY3.
Collapse
Affiliation(s)
- William Donelan
- From the Department of Pathology, Immunology, and Laboratory Medicine, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Vijay Koya
- From the Department of Pathology, Immunology, and Laboratory Medicine, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Shi-Wu Li
- From the Department of Pathology, Immunology, and Laboratory Medicine, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Li-Jun Yang
- From the Department of Pathology, Immunology, and Laboratory Medicine, University of Florida College of Medicine, Gainesville, Florida 32610
| |
Collapse
|
11
|
Harries LW, Brown JE, Gloyn AL. Species-specific differences in the expression of the HNF1A, HNF1B and HNF4A genes. PLoS One 2009; 4:e7855. [PMID: 19924231 PMCID: PMC2773013 DOI: 10.1371/journal.pone.0007855] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Accepted: 10/21/2009] [Indexed: 11/19/2022] Open
Abstract
Background The HNF1A, HNF1B and HNF4A genes are part of an autoregulatory network in mammalian pancreas, liver, kidney and gut. The layout of this network appears to be similar in rodents and humans, but inactivation of HNF1A, HNF1B or HNF4A genes in animal models cause divergent phenotypes to those seen in man. We hypothesised that some differences may arise from variation in the expression profile of alternatively processed isoforms between species. Methodology/Principal Findings We measured the expression of the major isoforms of the HNF1A, HNF1B and HNF4A genes in human and rodent pancreas, islet, liver and kidney by isoform-specific quantitative real-time PCR and compared their expression by the comparative Ct (ΔΔCt) method. We found major changes in the expression profiles of the HNF genes between humans and rodents. The principal difference lies in the expression of the HNF1A gene, which exists as three isoforms in man, but as a single isoform only in rodents. More subtle changes were to the balance of HNF1B and HNF4A isoforms between species; the repressor isoform HNF1B(C) comprised only 6% in human islets compared with 24–26% in rodents (p = 0.006) whereas HNF4A9 comprised 22% of HNF4A expression in human pancreas but only 11% in rodents (p = 0.001). Conclusions/Significance The differences we note in the isoform-specific expression of the human and rodent HNF1A, HNF1B and HNF4A genes may impact on the absolute activity of these genes, and therefore on the activity of the pancreatic transcription factor network as a whole. We conclude that alterations to expression of HNF isoforms may underlie some of the phenotypic variation caused by mutations in these genes.
Collapse
Affiliation(s)
- Lorna W Harries
- Institute of Biomedical and Clinical Sciences, Peninsula Medical School, University of Exeter, Exeter, United Kingdom.
| | | | | |
Collapse
|
12
|
Huang J, Levitsky LL, Rhoads DB. Novel P2 promoter-derived HNF4alpha isoforms with different N-terminus generated by alternate exon insertion. Exp Cell Res 2009; 315:1200-11. [PMID: 19353766 DOI: 10.1016/j.yexcr.2009.01.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hepatocyte nuclear factor 4alpha (HNF4alpha) is a critical transcription factor for pancreas and liver development and functions in islet beta cells to maintain glucose homeostasis. Mutations in the human HNF4A gene lead to maturity onset diabetes of the young (MODY1) and polymorphisms are associated with increased risk for type 2 diabetes mellitus (T2DM). Expression of six HNF4alpha variants, three each from two developmentally regulated promoters, has been firmly established. We have now detected a new set of HNF4alpha variants designated HNF4alpha10-12 expressed from distal promoter P2. These variants, generated by inclusion of previously undetected exon 1E (human=222 nt, rodent=136 nt) following exon 1D have an altered N-terminus but identical remaining reading frame. HNF4alpha10-alpha12 are expressed in pancreatic islets (and liver) and exhibit transactivation potentials similar to the corresponding alpha7-alpha9 isoforms. DNA-binding analyses implied much higher protein levels of HNF4alpha10-alpha12 in liver than expected from the RT-PCR data. Our results provide evidence for a more complex expression pattern of HNF4alpha than previously appreciated. We recommend inclusion of exon 1E and nearby DNA sequences in screening for HNF4alpha mutations and polymorphisms in genetic analyses of MODY1 and T2DM.
Collapse
Affiliation(s)
- Jianmin Huang
- MassGeneral Hospital for Children, Harvard Medical School, Boston, Massachusetts 02114-2696, USA.
| | | | | |
Collapse
|
13
|
Current literature in diabetes. Diabetes Metab Res Rev 2009; 25:i-xii. [PMID: 19405078 DOI: 10.1002/dmrr.973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|