1
|
He J, Yang X, Zhang C, Li A, Wang W, Xing J, E J, Xu X, Wang H, Yu E, Shi D, Wang H. CNN2 silencing inhibits colorectal cancer development through promoting ubiquitination of EGR1. Life Sci Alliance 2023; 6:e202201639. [PMID: 37188478 PMCID: PMC10185810 DOI: 10.26508/lsa.202201639] [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: 07/29/2022] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/17/2023] Open
Abstract
Colorectal cancer (CRC) is one of the most commonly diagnosed malignant tumors of the digestive tract. H2-calponin (CNN2), an actin cytoskeleton-binding protein, is an isoform of the calponin protein family whose role in CRC is still unknown. Research based on clinical samples showed the up-regulation of CNN2 in CRC and its association with tumor development, metastasis, and poor prognosis of patients. Both in vitro loss-of-function and gain-of-function experiments showed that CNN2 participates in CRC development through influencing malignant cell phenotypes. In vivo, xenografts formed by CNN2 knockdown cells also showed a slower growth rate and smaller final tumors. Furthermore, EGR1 was identified as a downstream of CNN2, forming a complex with CNN2 and YAP1 and playing an essential role in the CNN2-induced regulation of CRC development. Mechanistically, CNN2 knockdown down-regulated EGR1 expression through enhancing its ubiquitination, thus decreasing its protein stability in a YAP1-dependent manner. In summary, CNN2 plays an EGR1-dependent promotion role in the development and progression of CRC, which may be a promising therapeutic target for CRC treatment.
Collapse
Affiliation(s)
- Jinghu He
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Xiaohong Yang
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Chuansen Zhang
- Department of Anatomy, Naval Medical University, Shanghai, China
| | - Ang Li
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Wei Wang
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Junjie Xing
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Jifu E
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Xiaodong Xu
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Hao Wang
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Enda Yu
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Debing Shi
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Hantao Wang
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| |
Collapse
|
2
|
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
|
3
|
Glucose Homeostasis and Pancreatic Islet Size Are Regulated by the Transcription Factors Elk-1 and Egr-1 and the Protein Phosphatase Calcineurin. Int J Mol Sci 2023; 24:ijms24010815. [PMID: 36614256 PMCID: PMC9821712 DOI: 10.3390/ijms24010815] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/29/2022] [Accepted: 12/30/2022] [Indexed: 01/06/2023] Open
Abstract
Pancreatic β-cells synthesize and secrete insulin. A key feature of diabetes mellitus is the loss of these cells. A decrease in the number of β-cells results in decreased biosynthesis of insulin. Increasing the number of β-cells should restore adequate insulin biosynthesis leading to adequate insulin secretion. Therefore, identifying proteins that regulate the number of β-cells is a high priority in diabetes research. In this review article, we summerize the results of three sophisticated transgenic mouse models showing that the transcription factors Elk-1 and Egr-1 and the Ca2+/calmodulin-regulated protein phosphatase calcineurin control the formation of sufficiently large pancreatic islets. Impairment of the biological activity of Egr-1 and Elk-1 in pancreatic β-cells leads to glucose intolerance and dysregulation of glucose homeostasis, the process that maintains glucose concentration in the blood within a narrow range. Transgenic mice expressing an activated calcineurin mutant also had smaller islets and showed hyperglycemia. Calcineurin induces dephosphorylation of Elk-1 which subsequently impairs Egr-1 biosynthesis and the biological functions of Elk-1 and Egr-1 to regulate islet size and glucose homeostasis.
Collapse
|
4
|
Lissek T. Activity-Dependent Induction of Younger Biological Phenotypes. Adv Biol (Weinh) 2022; 6:e2200119. [PMID: 35976161 DOI: 10.1002/adbi.202200119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/11/2022] [Indexed: 01/28/2023]
Abstract
In several mammalian species, including humans, complex stimulation patterns such as cognitive and physical exercise lead to improvements in organ function, organism health and performance, as well as possibly longer lifespans. A framework is introduced here in which activity-dependent transcriptional programs, induced by these environmental stimuli, move somatic cells such as neurons and muscle cells toward a state that resembles younger cells to allow remodeling and adaptation of the organism. This cellular adaptation program targets several process classes that are heavily implicated in aging, such as mitochondrial metabolism, cell-cell communication, and epigenetic information processing, and leads to functional improvements in these areas. The activity-dependent gene program (ADGP) can be seen as a natural, endogenous cellular reprogramming mechanism that provides deep insight into the principles of inducible improvements in cell and organism function and can guide the development of therapeutic approaches for longevity. Here, these ADGPs are analyzed, exemplary critical molecular nexus points such as cAMP response element-binding protein, myocyte enhancer factor 2, serum response factor, and c-Fos are identified, and it is explored how one may leverage them to prevent, attenuate, and reverse human aging-related decline of body function.
Collapse
Affiliation(s)
- Thomas Lissek
- Interdisciplinary Center for Neurosciences, Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany
| |
Collapse
|
5
|
Salguero-Aranda C, Beltran-Povea A, Postigo-Corrales F, Hitos AB, Díaz I, Caballano-Infantes E, Fraga MF, Hmadcha A, Martín F, Soria B, Tapia-Limonchi R, Bedoya FJ, Tejedo JR, Cahuana GM. Pdx1 Is Transcriptionally Regulated by EGR-1 during Nitric Oxide-Induced Endoderm Differentiation of Mouse Embryonic Stem Cells. Int J Mol Sci 2022; 23:ijms23073920. [PMID: 35409280 PMCID: PMC8999925 DOI: 10.3390/ijms23073920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 03/29/2022] [Indexed: 11/16/2022] Open
Abstract
The transcription factor, early growth response-1 (EGR-1), is involved in the regulation of cell differentiation, proliferation, and apoptosis in response to different stimuli. EGR-1 is described to be involved in pancreatic endoderm differentiation, but the regulatory mechanisms controlling its action are not fully elucidated. Our previous investigation reported that exposure of mouse embryonic stem cells (mESCs) to the chemical nitric oxide (NO) donor diethylenetriamine nitric oxide adduct (DETA-NO) induces the expression of early differentiation genes such as pancreatic and duodenal homeobox 1 (Pdx1). We have also evidenced that Pdx1 expression is associated with the release of polycomb repressive complex 2 (PRC2) and P300 from the Pdx1 promoter; these events were accompanied by epigenetic changes to histones and site-specific changes in the DNA methylation. Here, we investigate the role of EGR-1 on Pdx1 regulation in mESCs. This study reveals that EGR-1 plays a negative role in Pdx1 expression and shows that the binding capacity of EGR-1 to the Pdx1 promoter depends on the methylation level of its DNA binding site and its acetylation state. These results suggest that targeting EGR-1 at early differentiation stages might be relevant for directing pluripotent cells into Pdx1-dependent cell lineages.
Collapse
Affiliation(s)
- Carmen Salguero-Aranda
- Department of Pathology, Institute of Biomedicine of Seville (IBiS), Virgen del Rocio University Hospital, CSIC-University of Seville, 41013 Seville, Spain
- Spanish Biomedical Research Network Centre in Oncology, CIBERONC of the Carlos III Health Institute (ISCIII), 28029 Madrid, Spain
- Department of Normal and Pathological Cytology and Histology, School of Medicine, University of Seville, 41004 Seville, Spain
- Correspondence: (C.S.-A.); (G.M.C.)
| | - Amparo Beltran-Povea
- Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, 41013 Seville, Spain; (A.B.-P.); (F.P.-C.); (E.C.-I.); (A.H.); (F.M.); (F.J.B.); (J.R.T.)
| | - Fátima Postigo-Corrales
- Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, 41013 Seville, Spain; (A.B.-P.); (F.P.-C.); (E.C.-I.); (A.H.); (F.M.); (F.J.B.); (J.R.T.)
| | - Ana Belén Hitos
- Biomedical Research Network for Diabetes and Related Metabolic Diseases-CIBERDEM of the Carlos III Health Institute (ISCIII), 08036 Madrid, Spain; (A.B.H.); (I.D.); (B.S.)
| | - Irene Díaz
- Biomedical Research Network for Diabetes and Related Metabolic Diseases-CIBERDEM of the Carlos III Health Institute (ISCIII), 08036 Madrid, Spain; (A.B.H.); (I.D.); (B.S.)
- Department of Regeneration and Cell Therapy Andalusian, Center for Molecular Biology and Regenerative Medicine (CABIMER), University of Pablo de Olavide-University of Seville-CSIC, 41013 Seville, Spain
| | - Estefanía Caballano-Infantes
- Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, 41013 Seville, Spain; (A.B.-P.); (F.P.-C.); (E.C.-I.); (A.H.); (F.M.); (F.J.B.); (J.R.T.)
- Department of Regeneration and Cell Therapy Andalusian, Center for Molecular Biology and Regenerative Medicine (CABIMER), University of Pablo de Olavide-University of Seville-CSIC, 41013 Seville, Spain
| | - Mario F. Fraga
- Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Cancer Epigenetics and Nanomedicine Laboratory, 33940 El Entrego, Spain;
- Health Research Institute of Asturias (ISPA), 33011 Oviedo, Spain
- Institute of Oncology of Asturias (IUOPA), University of Oviedo, 33006 Oviedo, Spain
- Rare Diseases CIBER (CIBERER) of the Carlos III Health Institute (ISCIII), 28029 Madrid, Spain
| | - Abdelkrim Hmadcha
- Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, 41013 Seville, Spain; (A.B.-P.); (F.P.-C.); (E.C.-I.); (A.H.); (F.M.); (F.J.B.); (J.R.T.)
- Department of Biotechnology, University of Alicante, 03690 Alicante, Spain
| | - Franz Martín
- Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, 41013 Seville, Spain; (A.B.-P.); (F.P.-C.); (E.C.-I.); (A.H.); (F.M.); (F.J.B.); (J.R.T.)
- Biomedical Research Network for Diabetes and Related Metabolic Diseases-CIBERDEM of the Carlos III Health Institute (ISCIII), 08036 Madrid, Spain; (A.B.H.); (I.D.); (B.S.)
- Department of Regeneration and Cell Therapy Andalusian, Center for Molecular Biology and Regenerative Medicine (CABIMER), University of Pablo de Olavide-University of Seville-CSIC, 41013 Seville, Spain
| | - Bernat Soria
- Biomedical Research Network for Diabetes and Related Metabolic Diseases-CIBERDEM of the Carlos III Health Institute (ISCIII), 08036 Madrid, Spain; (A.B.H.); (I.D.); (B.S.)
- Department of Biotechnology, University of Alicante, 03690 Alicante, Spain
- Health Research Institute-ISABIAL Dr Balmis University Hospital and Institute of Bioengineering, University Miguel Hernández de Elche, 03010 Alicante, Spain
| | - Rafael Tapia-Limonchi
- Tropical Disease Institute, Universidad Nacional Toribio Rodríguez de Mendoza, Amazonas 01001, Peru;
| | - Francisco J. Bedoya
- Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, 41013 Seville, Spain; (A.B.-P.); (F.P.-C.); (E.C.-I.); (A.H.); (F.M.); (F.J.B.); (J.R.T.)
- Biomedical Research Network for Diabetes and Related Metabolic Diseases-CIBERDEM of the Carlos III Health Institute (ISCIII), 08036 Madrid, Spain; (A.B.H.); (I.D.); (B.S.)
| | - Juan R. Tejedo
- Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, 41013 Seville, Spain; (A.B.-P.); (F.P.-C.); (E.C.-I.); (A.H.); (F.M.); (F.J.B.); (J.R.T.)
- Biomedical Research Network for Diabetes and Related Metabolic Diseases-CIBERDEM of the Carlos III Health Institute (ISCIII), 08036 Madrid, Spain; (A.B.H.); (I.D.); (B.S.)
- Tropical Disease Institute, Universidad Nacional Toribio Rodríguez de Mendoza, Amazonas 01001, Peru;
| | - Gladys M. Cahuana
- Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, 41013 Seville, Spain; (A.B.-P.); (F.P.-C.); (E.C.-I.); (A.H.); (F.M.); (F.J.B.); (J.R.T.)
- Biomedical Research Network for Diabetes and Related Metabolic Diseases-CIBERDEM of the Carlos III Health Institute (ISCIII), 08036 Madrid, Spain; (A.B.H.); (I.D.); (B.S.)
- Correspondence: (C.S.-A.); (G.M.C.)
| |
Collapse
|
6
|
Nihad M, Shenoy P S, Bose B. Cell therapy research for Diabetes: Pancreatic β cell differentiation from pluripotent stem cells. Diabetes Res Clin Pract 2021; 181:109084. [PMID: 34673084 DOI: 10.1016/j.diabres.2021.109084] [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: 03/23/2021] [Revised: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 12/16/2022]
Abstract
Human pluripotent stem cells (PSCs), both embryonic and induced pluripotent stem cells (iPSCs), have been differentiated into pancreatic β isletsin vitrofor more than a decade. The idea is to get enough β cells for cell transplantation for diabetics. Finding a standard cell therapy for diabetes is essential because of the logarithmic increase in the global population of people with diabetes and the insufficient availability of the human cadaveric pancreas. Moreover, with better insights into developmental biology, thein vitroβ cell differentiation protocols have depended on thein vivoβ cell organogenesis. Various protocols for pancreatic β cell differentiation have been developed. Such protocols are based on the modulation of cell signalling pathways with growth factors, small molecules, RNAi approaches, directed differentiation using transcription factors, genome editing. Growth factor free differentiation protocols, epigenetic modulations, 3D differentiation approaches, and encapsulation strategies have also been reported for better glycemic control and endocrine modulations. Here, we have reviewed various aforementionedin vitroβ cell differentiation protocols from human PSCs, their respective comparisons, challenges, past, present, and future. The literature has been reviewed primarily from PubMed from the year 2000 till date using the mentioned keywords.
Collapse
Affiliation(s)
- Muhammad Nihad
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, Pincode-575 018, Karnataka, India
| | - Sudheer Shenoy P
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, Pincode-575 018, Karnataka, India
| | - Bipasha Bose
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, Pincode-575 018, Karnataka, India.
| |
Collapse
|
7
|
Leu SY, Kuo LH, Weng WT, Lien IC, Yang CC, Hsieh TT, Cheng YN, Chien PH, Ho LC, Chen SH, Shan YS, Chen YW, Chen PC, Tsai PJ, Sung JM, Tsai YS. Loss of EGR-1 uncouples compensatory responses of pancreatic β cells. Theranostics 2020; 10:4233-4249. [PMID: 32226550 PMCID: PMC7086362 DOI: 10.7150/thno.40664] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/19/2020] [Indexed: 01/02/2023] Open
Abstract
Rationale: Subjects unable to sustain β-cell compensation develop type 2 diabetes. Early growth response-1 protein (EGR-1), implicated in the regulation of cell differentiation, proliferation, and apoptosis, is induced by diverse metabolic challenges, such as glucose or other nutrients. Therefore, we hypothesized that deficiency of EGR-1 might influence β-cell compensation in response to metabolic overload. Methods: Mice deficient in EGR-1 (Egr1-/-) were used to investigate the in vivo roles of EGR-1 in regulation of glucose homeostasis and beta-cell compensatory responses. Results: In response to a high-fat diet, Egr1-/- mice failed to secrete sufficient insulin to clear glucose, which was associated with lower insulin content and attenuated hypertrophic response of islets. High-fat feeding caused a dramatic impairment in glucose-stimulated insulin secretion and downregulated the expression of genes encoding glucose sensing proteins. The cells co-expressing both insulin and glucagon were dramatically upregulated in islets of high-fat-fed Egr1-/- mice. EGR-1-deficient islets failed to maintain the transcriptional network for β-cell compensatory response. In human pancreatic tissues, EGR1 expression correlated with the expression of β-cell compensatory genes in the non-diabetic group, but not in the diabetic group. Conclusion: These results suggest that EGR-1 couples the transcriptional network to compensation for the loss of β-cell function and identity. Thus, our study highlights the early stress coupler EGR-1 as a critical factor in the development of pancreatic islet failure.
Collapse
|
8
|
Werneck-de-Castro JP, Blandino-Rosano M, Hilfiker-Kleiner D, Bernal-Mizrachi E. Glucose stimulates microRNA-199 expression in murine pancreatic β-cells. J Biol Chem 2020; 295:1261-1270. [PMID: 31882540 PMCID: PMC6996880 DOI: 10.1074/jbc.ra119.010356] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/12/2019] [Indexed: 12/15/2022] Open
Abstract
MicroRNA 199 (miR-199) negatively impacts pancreatic β-cell function and its expression is highly increased in islets from diabetic mice as well as in plasma of diabetic patients. Here we investigated how miR-199 expression is regulated in β-cells by assessing expression of miR-199 precursors (primiR-199a1, primiR-199a2, and primiR-199b) and mature miR-199 (miR-199-3p and miR-199-5p) and promoter transcriptional activity assays in mouse islets and mouse insulinoma cells (MIN6) under different stimuli. We found that mouse islets equally express miR-199-3p and miR-199-5p. However, the primiRNA expression levels differed; although primiR-199a1 expression was about 30% greater than that of primiR-199a2, primiR-199b is barely detected in islets. We observed a 2-fold increase in primiR-199a1 and primiR-199a2 mRNA levels in mouse islets cultured in 10 mm glucose compared with 5.5 mm glucose. Similar responses to glucose were observed in MIN6 cells. Exposure to 30 mm KCl to induce membrane depolarization and calcium influx increased expression of primiR-199a2 but not of primiR-199a1 in MIN6 cells, indicating that calcium influx was involved. Transcriptional activity studies in MIN6 cells also revealed that primiR-199a2 promoter activity was enhanced by glucose and reduced by 2-deoxy-D-glucose-induced starvation. KCl and the potassium channel blocker tolbutamide also stimulated primiR-199a2 promoter activity. Calcium channel blockade by nifedipine reduced primiR-199a2 promoter activity in MIN6 cells, and diazoxide-mediated calcium influx inhibition blunted glucose up-regulation of miR-199-3p in islets. In conclusion, we uncover that glucose acutely up-regulates miR-199 family expression in β-cells. Glucose metabolism and calcium influx are involved in primiR-199a2 expression but not primiR-199a1 expression.
Collapse
Affiliation(s)
- Joao Pedro Werneck-de-Castro
- Division of Endocrinology, Diabetes, and Metabolism, University of Miami, Miller School of Medicine, Miami, Florida 33136,Miami Veterans Affairs Health Care System, Miami, Florida 33136
| | - Manuel Blandino-Rosano
- Division of Endocrinology, Diabetes, and Metabolism, University of Miami, Miller School of Medicine, Miami, Florida 33136
| | | | - Ernesto Bernal-Mizrachi
- Division of Endocrinology, Diabetes, and Metabolism, University of Miami, Miller School of Medicine, Miami, Florida 33136 .,Miami Veterans Affairs Health Care System, Miami, Florida 33136
| |
Collapse
|
9
|
Werneck-de-Castro JP, Blandino-Rosano M, Hilfiker-Kleiner D, Bernal-Mizrachi E. Glucose stimulates microRNA-199 expression in murine pancreatic β-cells. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49884-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
|
10
|
Sabatini PV, Speckmann T, Lynn FC. Friend and foe: β-cell Ca 2+ signaling and the development of diabetes. Mol Metab 2019; 21:1-12. [PMID: 30630689 PMCID: PMC6407368 DOI: 10.1016/j.molmet.2018.12.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/03/2018] [Accepted: 12/19/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The divalent cation Calcium (Ca2+) regulates a wide range of processes in disparate cell types. Within insulin-producing β-cells, increases in cytosolic Ca2+ directly stimulate insulin vesicle exocytosis, but also initiate multiple signaling pathways. Mediated through activation of downstream kinases and transcription factors, Ca2+-regulated signaling pathways leverage substantial influence on a number of critical cellular processes within the β-cell. Additionally, there is evidence that prolonged activation of these same pathways is detrimental to β-cell health and may contribute to Type 2 Diabetes pathogenesis. SCOPE OF REVIEW This review aims to briefly highlight canonical Ca2+ signaling pathways in β-cells and how β-cells regulate the movement of Ca2+ across numerous organelles and microdomains. As a main focus, this review synthesizes experimental data from in vitro and in vivo models on both the beneficial and detrimental effects of Ca2+ signaling pathways for β-cell function and health. MAJOR CONCLUSIONS Acute increases in intracellular Ca2+ stimulate a number of signaling cascades, resulting in (de-)phosphorylation events and activation of downstream transcription factors. The short-term stimulation of these Ca2+ signaling pathways promotes numerous cellular processes critical to β-cell function, including increased viability, replication, and insulin production and secretion. Conversely, chronic stimulation of Ca2+ signaling pathways increases β-cell ER stress and results in the loss of β-cell differentiation status. Together, decades of study demonstrate that Ca2+ movement is tightly regulated within the β-cell, which is at least partially due to its dual roles as a potent signaling molecule.
Collapse
Affiliation(s)
- Paul V Sabatini
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada; Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Thilo Speckmann
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Francis C Lynn
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
| |
Collapse
|
11
|
Karimi S, Ai J, Khorsandi L, Bijan Nejad D, Saki G. Vildagliptin Enhances Differentiation of Insulin Producing Cells from Adipose-Derived Mesenchymal Stem Cells. CELL JOURNAL 2018; 20:477-482. [PMID: 30123993 PMCID: PMC6099143 DOI: 10.22074/cellj.2019.5542] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 12/20/2017] [Indexed: 12/11/2022]
Abstract
Objective Type 1 diabetes is caused by destruction of beta cells of pancreas. Vildagliptin (VG), a dipeptidyl peptidase IV
(DPP IV) inhibitor, is an anti-diabetic drug, which increases beta cell mass. In the present study, the effects of VG on generation
of insulin-producing cells (IPCs) from adipose-derived mesenchymal stem cells (ASCs) is investigated.
Materials and Methods In this experimental study, ASCs were isolated and after characterization were exposed to
differentiation media with or without VG. The presence of IPCs was confirmed by morphological analysis and gene expression
(Pdx-1, Glut-2 and Insulin). Newport Green staining was used to determine insulin-positive cells. Insulin secretion under
different concentrations of glucose was measured using radioimmunoassay method.
Results In the presence of VG the morphology of differentiated cells was similar to the pancreatic islet cells. Expression
of Pdx-1, Glut-2 and Insulin genes in VG-treated cells was significantly higher than the cells exposed to induction media
only. Insulin release from VG-treated ASCs showed a nearly 3.6 fold (P<0.05) increase when exposed to a high-
glucose medium in comparison to untreated ASCs. The percentage of insulin-positive cells in the VG-treated cells was
approximately 2.9-fold higher than the untreated ASCs.
Conclusion The present study has demonstrated that VG elevates differentiation of ASCs into IPCs. Improvement of this
protocol may be used in cell therapy in diabetic patients.
Collapse
Affiliation(s)
- Samaneh Karimi
- Cell and Molecular Research Center, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Jafar Ai
- Tissue Engineering and Applied Cell Sciences, Department-School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Layasadat Khorsandi
- Cell and Molecular Research Center, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Electronic Address:
| | - Darioush Bijan Nejad
- Cell and Molecular Research Center, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ghasem Saki
- Cell and Molecular Research Center, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| |
Collapse
|
12
|
Wu X, Li Z, Chen K, Yin P, Zheng L, Sun S, Chen X. Egr-1 transactivates WNT5A gene expression to inhibit glucose-induced β-cell proliferation. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2018; 1861:S1874-9399(18)30218-9. [PMID: 30025875 DOI: 10.1016/j.bbagrm.2018.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 07/10/2018] [Accepted: 07/13/2018] [Indexed: 02/07/2023]
Abstract
Selective β-cell loss is a characteristic of type 2 diabetes mellitus (T2DM). Inhibition of glucose-stimulated β-cell proliferation is one of the in vivo results of the lipotoxicity of saturated fatty acids (SFAs). However, the mechanism by which lipotoxicity inhibits β-cell proliferation is still unclear. In this study, we found palmitate, a saturated fatty acid, inhibited the β-cell proliferation induced by high glucose through the induction of Wnt5a expression in vitro and in vivo. We also found that Wnt5a was both sufficient and necessary for inhibition of β-cell proliferation. Additionally, Egr-1, but not NF-κB, FOXO1, Smad2, Smad3, SP1 or SP3 mediated the expression of Wnt5a. Deletion and site-directed mutagenesis of the WNT5A promoter revealed that activation of WNT5A gene transcription depends primarily on a putative Egr-binding sequence between nucleotides -52 to -44, upstream of the transcription start site. Furthermore, Egr-1 bound directly to this sequence in response to palmitate treatment, both in vitro and in vivo. Moreover, after mice islets were treated with Egr inhibitors, the expression of Wnt5a decreased significantly and the glucose-induced β-cell proliferation inhibited by palmitate was resumed. These findings establish Wnt5a as an Egr-1 target gene in β-cells, uncovering a novel Egr-1/Wnt5a pathway by which saturated free fatty acids block glucose-induced β-cell proliferation. Our study lends support for the potential of Egr-1 inhibitors or Wnt5a antibodies as therapeutics for the treatment of T2DM.
Collapse
Affiliation(s)
- XingEr Wu
- The Molecular Diagnostic Center, Zhongshan City People's Hospital, Zhongshan 528403, Guangdong, China; Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong, China
| | - ZeHong Li
- Guzhen Sub-bureau, Zhongshan Public Security Bureau, Zhongshan 528400, Guangdong, China
| | - Kang Chen
- Zhongshan City People's Hospital, Zhongshan 528403, Guangdong, China
| | - PeiHong Yin
- Zhongshan City People's Hospital, Zhongshan 528403, Guangdong, China
| | - Lei Zheng
- Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong, China.
| | - ShiJun Sun
- The Molecular Diagnostic Center, Zhongshan City People's Hospital, Zhongshan 528403, Guangdong, China.
| | - XiaoYu Chen
- The Eighth Affiliated Hospital of Sun Yat-Sen University, Futian, 518000 Shenzhen, China.
| |
Collapse
|
13
|
Tsugata T, Nikoh N, Kin T, Miyagi-Shiohira C, Nakashima Y, Saitoh I, Noguchi Y, Ueki H, Watanabe M, Kobayashi N, Shapiro AMJ, Noguchi H. Role of Egr1 on Pancreatic Endoderm Differentiation. CELL MEDICINE 2018; 10:2155179017733177. [PMID: 32634182 PMCID: PMC6172987 DOI: 10.1177/2155179017733177] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/18/2017] [Accepted: 04/27/2017] [Indexed: 11/17/2022]
Abstract
The low efficiency of in vitro differentiation of human embryonic stem cells (hESCs) or human-induced pluripotent stem cells (iPSCs) into insulin-producing cells is a crucial hurdle for the clinical implementation of human pluripotent stem cells (PSCs). Our previous investigation into the key factors for the differentiation of PSCs into insulin-producing cells suggested that the expression of GATA binding protein 6 (GATA6) and Gremlin 1 (GREM1) and inhibition of early growth response protein 1 (Egr1) may be important factors. In this study, we investigated the role of Egr1 in pancreas development. The transfection of small interfering RNA (siRNA) of Egr1 in the early phase induced the differentiation of iPSCs derived from fibroblasts (FiPSCs) into pancreatic endoderm and insulin-producing cells. In contrast, the downregulation of Egr1 in the late phase suppressed the differentiation of FiPSCs into pancreatic endoderm and insulin-producing cells. In addition, the overexpression of Egr1 suppressed the differentiation of iPSCs derived from pancreatic cells into pancreatic endoderm and insulin-producing cells. These data suggest that the downregulation of Egr1 in the early phase can efficiently induce the differentiation of iPSCs into insulin-producing cells.
Collapse
Affiliation(s)
- Takako Tsugata
- Natural and Environmental Sciences Program, The Open University of Japan, Chiba, Japan
| | - Naruo Nikoh
- Natural and Environmental Sciences Program, The Open University of Japan, Chiba, Japan
| | - Tatsuya Kin
- Clinical Islet Transplant Program, University of Alberta, Edmonton, Alberta, Canada
| | - Chika Miyagi-Shiohira
- Department of Regenerative Medicine, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Yoshiki Nakashima
- Department of Regenerative Medicine, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Issei Saitoh
- Division of Pediatric Dentistry, Graduate School of Medical and Dental Science, Niigata University, Niigata, Japan
| | - Yasufumi Noguchi
- Department of Socio-environmental Design, Hiroshima International University, Hiroshima, Japan
| | - Hideo Ueki
- Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Masami Watanabe
- Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | | | | | - Hirofumi Noguchi
- Department of Regenerative Medicine, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| |
Collapse
|
14
|
Mao L, Wang H, Ma F, Guo Z, He H, Zhou H, Wang N. Exposure to static magnetic fields increases insulin secretion in rat INS-1 cells by activating the transcription of the insulin gene and up-regulating the expression of vesicle-secreted proteins. Int J Radiat Biol 2017; 93:831-840. [PMID: 28593826 DOI: 10.1080/09553002.2017.1332439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
PURPOSE To evaluate the effect of static magnetic fields (SMFs) on insulin secretion and explore the mechanisms underlying exposure to SMF-induced insulin secretion in rat insulinoma INS-1 cells. MATERIALS AND METHODS INS-1 cells were exposed to a 400 mT SMF for 72 h, and the proliferation of INS-1 cells was detected by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The secretion of insulin was measured with an enzyme linked immunosorbent assays (ELISA), the expression of genes was detected by real-time PCR, and the expression of proteins was measured by Western blotting. RESULTS Exposure to an SMF increased the expression and secretion of insulin by INS-1 cells but did not affect cell proliferation. Moreover, SMF exposure up-regulated the expression of several pancreas-specific transcriptional factors. Specifically, the activity of the rat insulin promoter was enhanced in INS-1 cells exposed to an SMF, and the expression levels of synaptosomal-associated protein 25 (SNAP-25) and syntaxin-1A were up-regulated after exposure to an SMF. CONCLUSIONS SMF exposure can promote insulin secretion in rat INS-1 cells by activating the transcription of the insulin gene and up-regulating the expression of vesicle-secreted proteins.
Collapse
Affiliation(s)
- Libin Mao
- a Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology , Tianjin University of Science and Technology , Tianjin , P.R. China
| | - Huiqin Wang
- a Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology , Tianjin University of Science and Technology , Tianjin , P.R. China
| | - Fenghui Ma
- a Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology , Tianjin University of Science and Technology , Tianjin , P.R. China
| | - Zhixia Guo
- a Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology , Tianjin University of Science and Technology , Tianjin , P.R. China
| | - Hongpeng He
- a Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology , Tianjin University of Science and Technology , Tianjin , P.R. China
| | - Hao Zhou
- a Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology , Tianjin University of Science and Technology , Tianjin , P.R. China
| | - Nan Wang
- a Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology , Tianjin University of Science and Technology , Tianjin , P.R. China
| |
Collapse
|
15
|
Wang C, Husain K, Zhang A, Centeno BA, Chen DT, Tong Z, Sebti SM, Malafa MP. EGR-1/Bax pathway plays a role in vitamin E δ-tocotrienol-induced apoptosis in pancreatic cancer cells. J Nutr Biochem 2015; 26:797-807. [PMID: 25997867 DOI: 10.1016/j.jnutbio.2015.02.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 12/13/2022]
Abstract
The anticancer activity of δ-tocotrienol, a bioactive vitamin E present in whole grain cereals, annatto beans and palm fruit, is strongly dependent on its effect on the induction of apoptosis. δ-Tocotrienol-induced apoptosis is associated with consistent induction in the expression of the proapoptotic protein Bcl-2-associated X protein (Bax). The molecular mechanism by which δ-tocotrienol regulates Bax expression is unknown. We carried out a DNA microarray study that identified δ-tocotrienol induction of the zinc finger transcription factor EGR-1 in pancreatic cancer cells. Here, we provide evidence linking δ-tocotrienol-induced apoptosis in pancreatic cancer cells to EGR-1 regulation of Bax expression. Forced expression of EGR-1 induces Bax expression and apoptosis in pancreatic cancer cells. In contrast, knockdown of δ-tocotrienol-induced EGR-1 by small interfering RNA attenuated δ-tocotrienol-induced Bax expression and reduced δ-tocotrienol-induced apoptosis. Further analyses showed that de novo protein synthesis was not required for δ-tocotrienol-induced EGR-1 expression, suggesting a direct effect of δ-tocotrienol on EGR-1 expression. Furthermore, a chromatin immunoprecipitation assay demonstrated that EGR-1 binds to the Bax gene promoter. Finally, δ-tocotrienol treatment induced Bax expression and activated EGR-1 in the pancreatic neoplastic cells of the PDX-Cre Kras genetically engineered model of pancreatic cancer. Our study provides the first evidence for EGR-1 as a direct target of vitamin E δ-tocotrienol, suggesting that EGR-1 may act as a proapoptotic factor in pancreatic cancer cells via induction of Bax.
Collapse
Affiliation(s)
- Chen Wang
- Department of Gastrointestinal Oncology, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL; Department of Breast Oncology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Kazim Husain
- Department of Gastrointestinal Oncology, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL
| | - Anying Zhang
- Department of Gastrointestinal Oncology, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL; Department of School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Barbara A Centeno
- Department of Pathology, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL
| | - Dung-Tsa Chen
- Department of Biostatistics, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL
| | - Zhongsheng Tong
- Department of Breast Oncology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Säid M Sebti
- Department of Drug Discovery, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL
| | - Mokenge P Malafa
- Department of Gastrointestinal Oncology, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL; Department of Drug Discovery, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL.
| |
Collapse
|
16
|
Loss of Egr-1 sensitizes pancreatic β-cells to palmitate-induced ER stress and apoptosis. J Mol Med (Berl) 2015; 93:807-18. [DOI: 10.1007/s00109-015-1272-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 01/23/2015] [Accepted: 02/11/2015] [Indexed: 01/07/2023]
|
17
|
Lesch A, Rubil S, Thiel G. Activation and inhibition of transient receptor potential TRPM3-induced gene transcription. Br J Pharmacol 2014; 171:2645-58. [PMID: 24895737 DOI: 10.1111/bph.12524] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND AND PURPOSE Transient receptor potential-3 (TRPM3) channels function as Ca2+ permeable cation channels. While the natural ligands for these channels are still unknown, several compounds have been described that either activate or inhibit TRPM3 channel activity. experimental approach: We assessed TRPM3-mediated gene transcription, which relies on the induction of intracellular signalling to the nucleus following activation of TRPM3 channels. Activator protein-1 (AP-1) and Egr-1-responsive reporter genes were integrated into the chromatin of the cells. This strategy enabled us to analyse gene transcription of the AP-1 and Egr-1-responsive reporter genes that were packed into an ordered chromatin structure. KEY RESULTS The neurosteroid pregnenolone sulfate strikingly up-regulated AP-1 and Egr-1 transcriptional activity, while nifedipine and D-erythro-sphingosine, also putative activators of TRPM3 channels, exhibited either no or TRPM3-independent effects on gene transcription. In addition, pregnenolone sulfate robustly enhanced the transcriptional activation potential of the ternary complex factor Elk-1. Pregnenolone sulfate-induced activation of gene transcription was blocked by treatment with mefenamic acid and, to a lesser extent, by the polyphenol naringenin. In contrast, progesterone, pregnenolone and rosiglitazone reduced AP-1 activity in the cells, but had no inhibitory effect on Egr-1 activity in pregnenolone sulfate-stimulated cells. CONCLUSION AND IMPLICATIONS Pregnenolone sulfate is a powerful activator of TRPM3-mediated gene transcription, while transcription is completely inhibited by mefenamic acid in cells expressing activated TRPM3 channels. Both compounds are valuable tools for further investigating the biological functions of TRPM3 channels.
Collapse
|
18
|
Tsugata T, Nikoh N, Kin T, Saitoh I, Noguchi Y, Ueki H, Watanabe M, James Shapiro AM, Noguchi H. Potential Factors for the Differentiation of ESCs/iPSCs Into Insulin-Producing Cells. CELL MEDICINE 2014; 7:83-93. [PMID: 26858897 DOI: 10.3727/215517914x685178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The low efficiency of in vitro differentiation of human embryonic stem cells (ESCs) or human induced pluripotent stem cells (iPSCs) into insulin-producing cells thus creates a crucial hurdle for the clinical implementation of human pluripotent stem cells (PSCs). In this study, we investigated the key factors for the differentiation of PSCs into insulin-producing cells. We obtained microarray data of HUES8 and HUES6 from two GeneChips (GPL3921: Affymetrix HT Human Genome U133A Array, GPL570: Affymetrix Human Genome U133 Plus 2.0 Array) in a database of GEO (NCBI), since HUES8 can differentiate into pancreatic cells, while HUES6 hardly demonstrates any differentiation at all. The genes with more than fourfold higher expressions in HUES8 compared to HUES6 included RPS4Y1, DDX3Y, EIF1AY, GREM1, GATA6, and NLGN4Y. Since there were four genes, RPS4Y1, DDX3Y, EIF1AY, and NLGN4Y, on the Y chromosome and HUES8 was a male cell line and HUES6 was a female cell line, we excluded these genes in this study. On the other hand, genes with more than fourfold higher expressions in HUES6 compared to HUES8 included NLRP2, EGR1, and SMC3. We next compared iPSCs derived from pancreatic cells (PiPSCs) and iPSCs derived from fibroblasts (FiPSCs). PiPSCs differentiated into insulin-producing cells more easily than FiPSCs because of their epigenetic memory. The gene expressions of GREM1, GATA6, NLRP2, EGR1, and SMC3 in PiPSCs and FiPSCs were also investigated. The expression level of GREM1 and GATA6 in PiPSCs were higher than in FiPSCs. On the other hand, EGR1, which was lower in HUES8 than in HUES6, was predictably lower in PiPSCs than FiPSCs, while NLRP2 and SMC3 were higher in PiPSCs than FiPSCs. These data suggest that the expression of GATA6 and GREM1 and the inhibition of EGR1 may be important factors for the differentiation of PSCs into insulin-producing cells.
Collapse
Affiliation(s)
- Takako Tsugata
- Natural and Environmental Sciences Program, The Open University of Japan , Chiba , Japan
| | - Naruo Nikoh
- Natural and Environmental Sciences Program, The Open University of Japan , Chiba , Japan
| | - Tatsuya Kin
- † Clinical Islet Transplant Program, University of Alberta , Edmonton, Alberta , Canada
| | - Issei Saitoh
- ‡ Division of Pediatric Dentistry, Graduate School of Medical and Dental Science, Niigata University , Niigata , Japan
| | - Yasufumi Noguchi
- § Department of Socio-environmental Design, Hiroshima International University , Hiroshima , Japan
| | - Hideo Ueki
- ¶ Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences , Okayama , Japan
| | - Masami Watanabe
- ¶ Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences , Okayama , Japan
| | | | - Hirofumi Noguchi
- Natural and Environmental Sciences Program, The Open University of Japan, Chiba, Japan; #Department of Regenerative Medicine, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| |
Collapse
|
19
|
Influence of Egr-1 in cardiac tissue-derived mesenchymal stem cells in response to glucose variations. BIOMED RESEARCH INTERNATIONAL 2014; 2014:254793. [PMID: 24967343 PMCID: PMC4054710 DOI: 10.1155/2014/254793] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 05/06/2014] [Indexed: 01/03/2023]
Abstract
Mesenchymal stem cells (MSCs) represent a promising cell population for cell therapy and regenerative medicine applications. However, how variations in glucose are perceived by MSC pool is still unclear. Since, glucose metabolism is cell type and tissue dependent, this must be considered when MSCs are derived from alternative sources such as the heart. The zinc finger transcription factor Egr-1 is an important early response gene, likely to play a key role in the glucose-induced response. Our aim was to investigate how short-term changes in in vitro glucose concentrations affect multipotent cardiac tissue-derived MSCs (cMSCs) in a mouse model of Egr-1 KO (Egr-1−/−). Results showed that loss of Egr-1 does not significantly influence cMSC proliferation. In contrast, responses to glucose variations were observed in wt but not in Egr-1−/− cMSCs by clonogenic assay. Phenotype analysis by RT-PCR showed that cMSCs Egr-1−/− lost the ability to regulate the glucose transporters GLUT-1 and GLUT-4 and, as expected, the Egr-1 target genes VEGF, TGFβ-1, and p300. Acetylated protein levels of H3 histone were impaired in Egr-1−/− compared to wt cMSCs. We propose that Egr-1 acts as immediate glucose biological sensor in cMSCs after a short period of stimuli, likely inducing epigenetic modifications.
Collapse
|
20
|
Thiel G, Müller I, Rössler OG. Expression, signaling and function of Egr transcription factors in pancreatic β-cells and insulin-responsive tissues. Mol Cell Endocrinol 2014; 388:10-9. [PMID: 24631481 DOI: 10.1016/j.mce.2014.03.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 02/26/2014] [Accepted: 03/03/2014] [Indexed: 12/15/2022]
Abstract
Egr-1 and the related zinc finger transcription factors Egr-2, Egr-3, and Egr-4 are stimulated by many extracellular signaling molecules and represent a convergence point for intracellular signaling cascades. Egr-1 expression is induced in insulinoma cells and pancreatic β-cells following stimulation with either glucose, or pregnenolone sulfate. Moreover, stimulation of Gαq and Gαs-coupled receptors enhances EGR-1 gene transcription. Functional studies revealed that Egr transcription factors control insulin biosynthesis via regulation of Pdx-1 expression. Glucose homeostasis and pancreatic islet size are regulated by Egr transcription factors, indicating that these proteins control central physiological parameters regulated by pancreatic β-cells. In addition, Egr-1 is an integral part of the insulin receptor signaling cascade in insulin-responsive tissues and influences insulin resistance.
Collapse
Affiliation(s)
- Gerald Thiel
- Department of Medical Biochemistry and Molecular Biology, University of Saarland Medical Center, D-66421 Homburg, Germany.
| | - Isabelle Müller
- Department of Medical Biochemistry and Molecular Biology, University of Saarland Medical Center, D-66421 Homburg, Germany
| | - Oliver G Rössler
- Department of Medical Biochemistry and Molecular Biology, University of Saarland Medical Center, D-66421 Homburg, Germany
| |
Collapse
|
21
|
Sabatini PV, Krentz NA, Zarrouki B, Westwell-Roper CY, Nian C, Uy RA, Shapiro AJ, Poitout V, Lynn FC. Npas4 is a novel activity-regulated cytoprotective factor in pancreatic β-cells. Diabetes 2013; 62:2808-20. [PMID: 23656887 PMCID: PMC3717850 DOI: 10.2337/db12-1527] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cellular homeostasis requires intrinsic sensing mechanisms to temper function in the face of prolonged activity. In the pancreatic β-cell, glucose is likely a physiological trigger that activates an adaptive response to stimulation, thereby maintaining cellular homeostasis. Immediate early genes (IEGs) are activated as a first line of defense in cellular homeostasis and are largely responsible for transmitting an environmental cue to a cellular response. Here we examine the regulation and function of the novel β-cell IEG, neuronal PAS domain protein 4 (Npas4). Using MIN6 cells, mouse and human islets, as well as in vivo infusions, we demonstrate that Npas4 is expressed within pancreatic islets and is upregulated by β-cell depolarizing agents. Npas4 tempers β-cell function through a direct inhibitory interaction with the insulin promoter and by blocking the potentiating effects of GLP-1 without significantly reducing glucose-stimulated secretion. Finally, Npas4 expression is induced by classical endoplasmic reticulum (ER) stressors and can prevent thapsigargin- and palmitate-induced dysfunction and cell death. These results suggest that Npas4 is a key activity-dependent regulator that improves β-cell efficiency in the face of stress. We posit that Npas4 could be a novel therapeutic target in type 2 diabetes that could both reduce ER stress and cell death and maintain basal cell function.
Collapse
Affiliation(s)
- Paul V. Sabatini
- Diabetes Research Group, Child and Family Research Institute, Vancouver, British Columbia, Canada
- Department of Surgery and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nicole A.J. Krentz
- Diabetes Research Group, Child and Family Research Institute, Vancouver, British Columbia, Canada
- Department of Surgery and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Bader Zarrouki
- Montreal Diabetes Research Center, CRCHUM, and Department of Medicine, Université de Montréal, Montréal, Quebec, Canada
| | - Clara Y. Westwell-Roper
- Diabetes Research Group, Child and Family Research Institute, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Cuilan Nian
- Diabetes Research Group, Child and Family Research Institute, Vancouver, British Columbia, Canada
- Department of Surgery and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ryan A. Uy
- Diabetes Research Group, Child and Family Research Institute, Vancouver, British Columbia, Canada
| | | | - Vincent Poitout
- Montreal Diabetes Research Center, CRCHUM, and Department of Medicine, Université de Montréal, Montréal, Quebec, Canada
| | - Francis C. Lynn
- Diabetes Research Group, Child and Family Research Institute, Vancouver, British Columbia, Canada
- Department of Surgery and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- Corresponding author: Francis C. Lynn,
| |
Collapse
|
22
|
Abstract
Transient receptor potential melastatin 3 (TRPM3) channels are non-selective cation channels that are expressed in insulinoma cells and pancreatic β-cells. Stimulation of TRPM3 with the neurosteroid pregnenolone sulfate induces an intracellular signaling cascade, involving a rise in intracellular Ca(2)(+) concentration, activation of the protein kinases Raf and ERK, and a change in the gene expression pattern of the cells. In particular, biosynthesis of insulin is altered following activation of TRPM3 by pregnenolone sulfate. Moreover, a direct effect of TRPM3 stimulation on insulin secretion has been reported. The fact that stimulation of TRPM3 induces a signaling cascade that is very similar to the signaling cascade induced by glucose in β-cells suggests that TRPM3 may influence main functions of pancreatic β-cells. The view that TRPM3 represents an ionotropic steroid receptor of pancreatic β-cells linking insulin release with steroid hormone signaling is discussed.
Collapse
Affiliation(s)
- Gerald Thiel
- Department of Medical Biochemistry and Molecular Biology, University of Saarland Medical Center, Building 44, D-66421 Homburg, Germany.
| | | | | |
Collapse
|
23
|
Abstract
When cellular reducing enzymes fail to shield the cell from increased amounts of reactive oxygen species (ROS), oxidative stress arises. The redox state is misbalanced, DNA and proteins are damaged and cellular transcription networks are activated. This condition can lead to the initiation and/or to the progression of atherosclerosis, tumors or pulmonary hypertension; diseases that are decisively furthered by the presence of oxidizing agents. Redox sensitive genes, like the zinc finger transcription factor early growth response 1 (Egr-1), play a pivotal role in the pathophysiology of these diseases. Apart from inducing apoptosis, signaling partners like the MEK/ERK pathway or the protein kinase C (PKC) can activate salvage programs such as cell proliferation that do not ameliorate, but rather worsen their outcome. Here, we review the currently available data on Egr-1 related signal transduction cascades in response to oxidative stress in the progression of epidemiologically significant diseases. Knowing the molecular pathways behind the pathology will greatly enhance our ability to identify possible targets for the development of new therapeutic strategies.
Collapse
|
24
|
Müller I, Rössler OG, Wittig C, Menger MD, Thiel G. Critical role of Egr transcription factors in regulating insulin biosynthesis, blood glucose homeostasis, and islet size. Endocrinology 2012; 153:3040-53. [PMID: 22597533 DOI: 10.1210/en.2012-1064] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Expression of early growth response protein (Egr)-1, a protein of the Egr family of zinc finger transcription factors, is stimulated in glucose-treated pancreatic β-cells and insulinoma cells. The purpose of this study was to elucidate the role of Egr transcription factors in pancreatic β-cells in vivo. To overcome the problem associated with redundancy of functions between Egr proteins, conditional transgenic mice were generated expressing a dominant-negative mutant of Egr-1 in pancreatic β-cells. The Egr-1 mutant interferes with DNA binding of all Egr proteins and thus impairs the biological functions of the entire Egr family. Expression of the Egr-1 mutant reduced expression of TGFβ and basic fibroblast growth factor, known target genes of Egr-1, whereas the expression of Egr-1, Egr-3, Ets-like gene-1 (Elk-1), and specificity protein-3 was not changed in the presence of the Egr-1 mutant. Expression of the homeobox protein pancreas duodenum homeobox-1, a major regulator of insulin biosynthesis, was reduced in islets expressing the Egr-1 mutant. Accordingly, insulin mRNA and protein levels were reduced by 75 or 25%, respectively, whereas expression of glucagon and somatostatin was not altered after expression of the Egr-1 mutant in β-cells. Glucose tolerance tests revealed that transgenic mice expressing the Egr-1 mutant in pancreatic β-cells displayed impaired glucose tolerance. In addition, increased caspase-3/7 activity was detected as a result of transgene expression, leading to a 20% decrease of the size of the islets. These results show that Egr proteins play an important role in controlling insulin biosynthesis, glucose homeostasis, and islet size of pancreatic β-cells in vivo.
Collapse
Affiliation(s)
- Isabelle Müller
- Department of Medical Biochemistry and Molecular Biology, Building 44, University of Saarland Medical Center, d-66421 Homburg, Germany
| | | | | | | | | |
Collapse
|
25
|
Wijesekara N, Dai FF, Hardy AB, Giglou PR, Bhattacharjee A, Koshkin V, Chimienti F, Gaisano HY, Rutter GA, Wheeler MB. Beta cell-specific Znt8 deletion in mice causes marked defects in insulin processing, crystallisation and secretion. Diabetologia 2010; 53:1656-68. [PMID: 20424817 PMCID: PMC6101216 DOI: 10.1007/s00125-010-1733-9] [Citation(s) in RCA: 224] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Accepted: 02/05/2010] [Indexed: 02/01/2023]
Abstract
AIMS/HYPOTHESIS Zinc is highly concentrated in pancreatic beta cells, is critical for normal insulin storage and may regulate glucagon secretion from alpha cells. Zinc transport family member 8 (ZnT8) is a zinc efflux transporter that is highly abundant in beta cells. Polymorphisms of ZnT8 (also known as SLC30A8) gene in man are associated with increased risk of type 2 diabetes. While global Znt8 knockout (Znt8KO) mice have been characterised, ZnT8 is also present in other islet cell types and extra-pancreatic tissues. Therefore, it is important to find ways of understanding the role of ZnT8 in beta and alpha cells without the difficulties caused by the confounding effects of ZnT8 in these other tissues. METHODS We generated mice with beta cell-specific (Znt8BKO) and alpha cell-specific (Znt8AKO) knockout of Znt8, and performed in vivo and in vitro characterisation of the phenotypes to determine the functional and anatomical impact of ZnT8 in these cells. Thus we assessed zinc accumulation, insulin granule morphology, insulin biosynthesis and secretion, and glucose homeostasis. RESULTS Znt8BKO mice are glucose-intolerant, have reduced beta cell zinc accumulation and atypical insulin granules. They also display reduced first-phase glucose-stimulated insulin secretion, reduced insulin processing enzyme transcripts and increased proinsulin levels. In contrast, Znt8AKO mice show no evident abnormalities in plasma glucagon and glucose homeostasis. CONCLUSIONS/INTERPRETATION This is the first report of specific beta and alpha cell deletion of Znt8. Our data indicate that while, under the conditions studied, ZnT8 is absolutely essential for proper beta cell function, it is largely dispensable for alpha cell function.
Collapse
Affiliation(s)
- N Wijesekara
- Department of Physiology, University of Toronto, 1 King's College Circle Room 3352, Toronto, ON, Canada M5S 1A8
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Katsarou K, Lavdas AΑ, Tsitoura P, Serti E, Markoulatos P, Mavromara P, Georgopoulou U. Endocytosis of hepatitis C virus non-enveloped capsid-like particles induces MAPK-ERK1/2 signaling events. Cell Mol Life Sci 2010; 67:2491-506. [PMID: 20358251 PMCID: PMC11115770 DOI: 10.1007/s00018-010-0351-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 03/08/2010] [Accepted: 03/11/2010] [Indexed: 12/12/2022]
Abstract
Although HCV is an enveloped virus, naked nucleocapsids have been reported in the serum of infected patients. The HCV core particle serves as a protective capsid shell for the viral genome and recombinant in vitro assembled HCV core particles induce strong specific immunity. We investigated the post-binding mechanism of recombinant core particle uptake and its intracellular fate. In hepatic cells, these particles are internalized, most likely in a clathrin-dependent pathway, reaching early to late endosomes and finally lysosomes. The endocytic acidic milieu is implicated in trafficking process. Using specific phosphoantibodies, signaling pathway inhibitors and chemical agents, ERK(1/2) was found to be activated in a sustained way after endocytosis, followed by downstream immediate early genes (c-fos and egr-1) modulation. We propose that the intriguing properties of cellular internalization of HCV non-enveloped particles can induce specific ERK(1/2)-MAPKs events that could be important in HCV life cycle and pathogenesis of HCV infection.
Collapse
Affiliation(s)
| | - Alexandros Α. Lavdas
- Laboratory of Cellular and Molecular Neurobiology, Hellenic Pasteur Institute, Athens, Greece
| | - Panagiota Tsitoura
- Present Address: Insect Molecular Genetics and Biotechnology, Institute of Biology, NCSR Demokritos, Athens, Greece
| | - Elisavet Serti
- Molecular Virology Laboratory, Hellenic Pasteur Institute, Athens, Greece
| | | | - Penelope Mavromara
- Molecular Virology Laboratory, Hellenic Pasteur Institute, Athens, Greece
| | | |
Collapse
|
27
|
Transcriptional regulation of glucose sensors in pancreatic β-cells and liver: an update. SENSORS 2010; 10:5031-53. [PMID: 22399922 PMCID: PMC3292162 DOI: 10.3390/s100505031] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 05/07/2010] [Accepted: 05/13/2010] [Indexed: 01/17/2023]
Abstract
Pancreatic β-cells and the liver play a key role in glucose homeostasis. After a meal or in a state of hyperglycemia, glucose is transported into the β-cells or hepatocytes where it is metabolized. In the β-cells, glucose is metabolized to increase the ATP:ADP ratio, resulting in the secretion of insulin stored in the vesicle. In the hepatocytes, glucose is metabolized to CO(2), fatty acids or stored as glycogen. In these cells, solute carrier family 2 (SLC2A2) and glucokinase play a key role in sensing and uptaking glucose. Dysfunction of these proteins results in the hyperglycemia which is one of the characteristics of type 2 diabetes mellitus (T2DM). Thus, studies on the molecular mechanisms of their transcriptional regulations are important in understanding pathogenesis and combating T2DM. In this paper, we will review a recent update on the progress of gene regulation of glucose sensors in the liver and β-cells.
Collapse
|
28
|
Humphrey RK, Yu SM, Flores LE, Jhala US. Glucose regulates steady-state levels of PDX1 via the reciprocal actions of GSK3 and AKT kinases. J Biol Chem 2010; 285:3406-16. [PMID: 19833727 PMCID: PMC2823452 DOI: 10.1074/jbc.m109.006734] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 10/09/2009] [Indexed: 12/31/2022] Open
Abstract
The pancreatic beta cell is sensitive to even small changes in PDX1 protein levels; consequently, Pdx1 haploinsufficiency can inhibit beta cell growth and decrease insulin biosynthesis and gene expression, leading to compromised glucose-stimulated insulin secretion. Using metabolic labeling of primary islets and a cultured beta cell line, we show that glucose levels modulate PDX1 protein phosphorylation at a novel C-terminal GSK3 consensus that maps to serines 268 and 272. A decrease in glucose levels triggers increased turnover of the PDX1 protein in a GSK3-dependent manner, such that PDX1 phosphomutants are refractory to the destabilizing effect of low glucose. Glucose-stimulated activation of AKT and inhibition of GSK3 decrease PDX1 phosphorylation and delay degradation. Furthermore, direct pharmacologic inhibition of AKT destabilizes, and inhibition of GSK3 increases PDX1 protein stability. These studies define a novel functional role for the PDX1 C terminus in mediating the effects of glucose and demonstrate that glucose modulates PDX1 stability via the AKT-GSK3 axis.
Collapse
Affiliation(s)
- Rohan K. Humphrey
- From the Department of Pediatrics, University of California San Diego, La Jolla, California 92037
| | - Shu-Mei Yu
- From the Department of Pediatrics, University of California San Diego, La Jolla, California 92037
| | - Luis E. Flores
- From the Department of Pediatrics, University of California San Diego, La Jolla, California 92037
| | - Ulupi S. Jhala
- From the Department of Pediatrics, University of California San Diego, La Jolla, California 92037
| |
Collapse
|
29
|
Kang JH, Chang SY, Jang HJ, Cho JM, Kim DB, Lee SS, Ko SH, Park YM, Needs PW, Jo YH, Kim MJ. Quercetin-induced upregulation of human GCLC gene is mediated bycis-regulatory element for early growth response protein-1 (EGR1) in INS-1 beta-cells. J Cell Biochem 2009; 108:1346-55. [DOI: 10.1002/jcb.22365] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
30
|
Ferguson LA, Docherty HM, MacKenzie AE, Docherty K. An engineered zinc finger protein reveals a role for the insulin VNTR in the regulation of the insulin and adjacent IGF2 genes. FEBS Lett 2009; 583:3181-6. [PMID: 19733567 DOI: 10.1016/j.febslet.2009.08.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Revised: 08/05/2009] [Accepted: 08/29/2009] [Indexed: 01/27/2023]
Abstract
An engineered zinc finger protein (eZFP) was isolated from a library based on its ability to activate expression of the endogenous insulin gene in HEK-293 cells. Using a panel of insulin promoter constructs, the eZFP was shown to act through the variable number of tandem repeat (VNTR) region located 365 base pairs upstream of the transcription start site. The eZFP also activated expression of the IGF2 gene that lies close to INS on chromosome 11p15. These results demonstrate that the INSVNTR controls expression of the insulin and IGF2 genes and provide a mechanistic explanation for previous studies that demonstrated an association between INSVNTR genotypes and placental levels of IGF2.
Collapse
Affiliation(s)
- Laura A Ferguson
- School of Medical Sciences, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, UK
| | | | | | | |
Collapse
|
31
|
Chan IHS, Tang NLS, Leung TF, Huang W, Lam YYO, Wong GWK, Chan JCN, Chan MHM, Wong CK, Zhang YP, Lam CWK. Association of early growth response-1 gene polymorphisms with total IgE and atopy in asthmatic children. Pediatr Allergy Immunol 2009; 20:142-50. [PMID: 18507785 DOI: 10.1111/j.1399-3038.2008.00757.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Early growth response-1 (Egr-1) is expressed in human airways and found to modulate tumor necrosis factor, immunoglobulin E (IgE), airway responsiveness, and interleukin-13-induced inflammation in mice. We investigated the effects of Chinese-tagging single nucleotide polymorphisms (SNPs) of Egr-1 on asthma traits in 298 Chinese asthmatic children and 175 controls, and a replication community cohort of 191 controls. Tag SNP (-4071 A-->G) and three additional SNPs (-1427 C-->T, -151 C-->T and IVS1 -42 C-->T) were genotyped by restriction fragment length polymorphism (RFLP). Significant associations were found between plasma total IgE concentration and -4071 A-->G (p = 0.008) and IVS1 -42 C-->T (p = 0.027) in asthmatic patients. After Bonferroni correction, only -4071 A-->G showed significant association. Multivariate regression analysis confirmed this significant association with a standardized coefficient beta of 0.156 (95% CI: 0.046-0.317; p = 0.009) in asthmatics among the three SNPs with age and gender-adjusted. In -4071 A-->G, IgE(log) was significantly higher in patients with the GG genotype than the AA genotype (p = 0.009). In addition, -4071 A-->G was significantly associated with atopy (p = 0.016) and high total IgE concentration (p = 0.030) among asthmatics. Patients with the G allele had a 3.5-fold risk of having atopy and a 2.0-fold risk of having high total IgE concentration than those homozygous for the A allele. This is the first report to show significant association of Egr-1 polymorphisms with plasma total IgE and atopy in asthmatics. It may help to explore the pharmacogenetics of Egr-1 inhibitors.
Collapse
Affiliation(s)
- Iris H S Chan
- Department of Chemical Pathology, The Chinese University of Hong Kong, Hong Kong
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Naito M, Shenoy A, Aoyama I, Koopmeiners JS, Komers R, Schnaper HW, Bomsztyk K. High ambient glucose augments angiotensin II-induced proinflammatory gene mRNA expression in human mesangial cells: effects of valsartan and simvastatin. Am J Nephrol 2009; 30:99-111. [PMID: 19225232 DOI: 10.1159/000203619] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Accepted: 01/16/2009] [Indexed: 12/28/2022]
Abstract
BACKGROUND Hyperglycemia may potentiate the adverse renal effects of angiotensin II (AII). In the kidney, the major target of AII action is the glomerular mesangial cell, where its hemodynamic and proinflammatory action contributes to renal injury. AII action is mediated by several types of cell receptors. Among those, the AT1 receptor has been best studied using specific AII receptor blockers (ARBs). These agents have emerged as major new modalities in the prevention and amelioration of renal disease where the ARB renoprotective anti-inflammatory properties could be more important than previously appreciated. Like the ARBs, statins may also modulate inflammatory responses that are renoprotective and complement their cholesterol-lowering effects. AIM The aim of this project was to (i) identify a repertoire of proinflammatory mesangial cell AII-inducible mRNAs; (ii) determine if the AII-induced proinflammatory mRNA responses depend on ambient glucose, and (iii) test the anti-inflammatory effectiveness of an ARB, valsartan, either alone or in combination with a statin, simvastatin. RESULTS/CONCLUSIONS Using high-density microarrays and real-time PCR we identified several AII-inducible proinflammatory mesangial genes that exhibited augmented mRNA responses in high-glucose milieu. Valsartan blocked the AII-induced mRNA expression of proinflammatory genes (i.e. MCP-1, LIF and COX-2) maintained in normal and high glucose. These observations add to the mounting evidence that ARBs have anti-inflammatory effects in the kidney, a beneficial effect that may be more important in protecting renal function in diabetic patients. While simvastatin inhibited expression of some mRNAs encoding chemokines/cytokines, it enhanced expression of mRNA encoding COX-2, a key mediator of inflammation. Thus, the non-cholesterol effects of statins on inflammatory responses appear complex.
Collapse
Affiliation(s)
- Masayo Naito
- UW Medicine Lake Union Research, University of Washington, Seattle, WA 98109, USA
| | | | | | | | | | | | | |
Collapse
|
33
|
Bibliography. Current world literature. Diabetes and the endocrine pancreas II. Curr Opin Endocrinol Diabetes Obes 2007; 14:329-57. [PMID: 17940461 DOI: 10.1097/med.0b013e3282c3a898] [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: 11/25/2022]
|
34
|
Eto K, Kaur V, Thomas MK. Regulation of pancreas duodenum homeobox-1 expression by early growth response-1. J Biol Chem 2006; 282:5973-83. [PMID: 17150967 DOI: 10.1074/jbc.m607288200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The homeodomain transcription factor pancreas duodenum homeobox-1 (PDX-1) is a key regulator of pancreatic beta-cell development, function, and survival. Deficits in PDX-1 expression result in insulin deficiency and hyperglycemia. We previously found that the glucose-responsive transcription factor early growth response-1 (Egr-1) activates the insulin promoter in part by increasing expression levels of PDX-1. We now report that Egr-1 binds and activates multiple regulatory sites within the pdx-1 promoter. We identified consensus Egr-1 recognition sequences within proximal and distal regions of the mouse pdx-1 promoter and demonstrated specific binding of Egr-1 by chromatin immunoprecipitation and electrophoretic mobility shift assays. Overexpression of Egr-1 increased transcriptional activation of the -4500 proximal pdx-1 promoter and of the highly conserved regulatory Areas I, II, and III. Mutagenesis of a specific Egr-1 binding site within Area III substantially decreased Egr-1-mediated activation. Egr-1 increased the transcriptional activation of Areas I and II, despite the absence of Egr-1 recognition sequences within this promoter segment, suggesting that Egr-1 also can regulate the pdx-1 promoter indirectly. Egr-1 increased, and a dominant-negative Egr-1 mutant repressed, the transcriptional activation of distal pdx-1 promoter sequences. Mutagenesis of a specific Egr-1 binding site within regulatory Area IV reduced basal and Egr-1-mediated transcriptional activation. Our data indicate that Egr-1 regulates expression of PDX-1 in pancreatic beta-cells by both direct and indirect activation of the pdx-1 promoter. We propose that Egr-1 expression levels may act as a sensor in pancreatic beta-cells to translate extracellular signals into changes in PDX-1 expression levels and pancreatic beta-cell function.
Collapse
Affiliation(s)
- Kazuhiro Eto
- Laboratory of Molecular Endocrinology and Diabetes Unit, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts 02114, USA
| | | | | |
Collapse
|