1
|
Dhanjal DS, Singh R, Sharma V, Nepovimova E, Adam V, Kuca K, Chopra C. Advances in Genetic Reprogramming: Prospects from Developmental Biology to Regenerative Medicine. Curr Med Chem 2024; 31:1646-1690. [PMID: 37138422 DOI: 10.2174/0929867330666230503144619] [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: 11/12/2022] [Revised: 03/13/2023] [Accepted: 03/16/2023] [Indexed: 05/05/2023]
Abstract
The foundations of cell reprogramming were laid by Yamanaka and co-workers, who showed that somatic cells can be reprogrammed into pluripotent cells (induced pluripotency). Since this discovery, the field of regenerative medicine has seen advancements. For example, because they can differentiate into multiple cell types, pluripotent stem cells are considered vital components in regenerative medicine aimed at the functional restoration of damaged tissue. Despite years of research, both replacement and restoration of failed organs/ tissues have remained elusive scientific feats. However, with the inception of cell engineering and nuclear reprogramming, useful solutions have been identified to counter the need for compatible and sustainable organs. By combining the science underlying genetic engineering and nuclear reprogramming with regenerative medicine, scientists have engineered cells to make gene and stem cell therapies applicable and effective. These approaches have enabled the targeting of various pathways to reprogramme cells, i.e., make them behave in beneficial ways in a patient-specific manner. Technological advancements have clearly supported the concept and realization of regenerative medicine. Genetic engineering is used for tissue engineering and nuclear reprogramming and has led to advances in regenerative medicine. Targeted therapies and replacement of traumatized , damaged, or aged organs can be realized through genetic engineering. Furthermore, the success of these therapies has been validated through thousands of clinical trials. Scientists are currently evaluating induced tissue-specific stem cells (iTSCs), which may lead to tumour-free applications of pluripotency induction. In this review, we present state-of-the-art genetic engineering that has been used in regenerative medicine. We also focus on ways that genetic engineering and nuclear reprogramming have transformed regenerative medicine and have become unique therapeutic niches.
Collapse
Affiliation(s)
- Daljeet Singh Dhanjal
- School of Bioengineering and Biosciences, Lovely Professional University, Phagwara, Punjab, India
| | - Reena Singh
- School of Bioengineering and Biosciences, Lovely Professional University, Phagwara, Punjab, India
| | - Varun Sharma
- Head of Bioinformatic Division, NMC Genetics India Pvt. Ltd., Gurugram, India
| | - Eugenie Nepovimova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, 50003, Czech Republic
| | - Vojtech Adam
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, Brno, CZ 613 00, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Purkynova 123, Brno, CZ-612 00, Czech Republic
| | - Kamil Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, 50003, Czech Republic
- Biomedical Research Center, University Hospital Hradec Kralove, Hradec Kralove, 50005, Czech Republic
| | - Chirag Chopra
- School of Bioengineering and Biosciences, Lovely Professional University, Phagwara, Punjab, India
| |
Collapse
|
2
|
Abidov M, Sokolova K, Danilova I, Baykenova M, Gette I, Mychlynina E, Aydin Ozgur B, Gurol AO, Yilmaz MT. Hepatic insulin synthesis increases in rat models of diabetes mellitus type 1 and 2 differently. PLoS One 2023; 18:e0294432. [PMID: 38019818 PMCID: PMC10686419 DOI: 10.1371/journal.pone.0294432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 11/01/2023] [Indexed: 12/01/2023] Open
Abstract
Insulin-positive (+) cells (IPCs), detected in multiple organs, are of great interest as a probable alternative to ameliorate pancreatic beta-cells dysfunction and insulin deficiency in diabetes. Liver is a potential source of IPCs due to it common embryological origin with pancreas. We previously demonstrated the presence of IPCs in the liver of healthy and diabetic rats, but detailed description and analysis of the factors, which potentially can induced ectopic hepatic expression of insulin in type 1 (T1D) and type 2 diabetes (T2D), were not performed. In present study we evaluate mass of hepatic IPCs in the rat models of T1D and T2D and discuss factors, which may stimulate it generation: glycaemia, organ injury, involving of hepatic stem/progenitor cell compartment, expression of transcription factors and inflammation. Quantity of IPCs in the liver was up by 1.7-fold in rats with T1D and 10-fold in T2D compared to non-diabetic (ND) rats. We concluded that ectopic hepatic expression of insulin gene is activated by combined action of a number of factors, with inflammation playing a decision role.
Collapse
Affiliation(s)
- Musa Abidov
- Institute of Immunopathology and Preventive Medicine, Ljubljana, Slovenia
| | - Ksenia Sokolova
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, Yekaterinburg, Russian Federation
| | - Irina Danilova
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, Yekaterinburg, Russian Federation
| | - Madina Baykenova
- Kostanay Oblast Tuberculosis Dispensary, Kostanay, Republic of Kazakhstan
| | - Irina Gette
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, Yekaterinburg, Russian Federation
| | - Elena Mychlynina
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, Yekaterinburg, Russian Federation
| | - Burcin Aydin Ozgur
- Department of Medical Biology and Genetics, Faculty of Medicine, Demiroglu Bilim University, Istanbul, Turkey
- Diabetes Application and Research Center, Demiroglu Bilim University, Istanbul, Turkey
| | - Ali Osman Gurol
- Department of Immunology, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
- Diabetes Application and Research Center, Istanbul University, Istanbul, Turkey
| | - M. Temel Yilmaz
- International Diabetes Center, Acibadem University, Istanbul, Turkey
| |
Collapse
|
3
|
Baeyens L, Lemper M, Staels W, De Groef S, De Leu N, Heremans Y, German MS, Heimberg H. (Re)generating Human Beta Cells: Status, Pitfalls, and Perspectives. Physiol Rev 2018; 98:1143-1167. [PMID: 29717931 DOI: 10.1152/physrev.00034.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Diabetes mellitus results from disturbed glucose homeostasis due to an absolute (type 1) or relative (type 2) deficiency of insulin, a peptide hormone almost exclusively produced by the beta cells of the endocrine pancreas in a tightly regulated manner. Current therapy only delays disease progression through insulin injection and/or oral medications that increase insulin secretion or sensitivity, decrease hepatic glucose production, or promote glucosuria. These drugs have turned diabetes into a chronic disease as they do not solve the underlying beta cell defects or entirely prevent the long-term complications of hyperglycemia. Beta cell replacement through islet transplantation is a more physiological therapeutic alternative but is severely hampered by donor shortage and immune rejection. A curative strategy should combine newer approaches to immunomodulation with beta cell replacement. Success of this approach depends on the development of practical methods for generating beta cells, either in vitro or in situ through beta cell replication or beta cell differentiation. This review provides an overview of human beta cell generation.
Collapse
Affiliation(s)
- Luc Baeyens
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Marie Lemper
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Willem Staels
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Sofie De Groef
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Nico De Leu
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Yves Heremans
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Michael S German
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Harry Heimberg
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| |
Collapse
|
4
|
Dey A, Lakshmanan J. The role of antioxidants and other agents in alleviating hyperglycemia mediated oxidative stress and injury in liver. Food Funct 2014; 4:1148-84. [PMID: 23760593 DOI: 10.1039/c3fo30317a] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Several antioxidants and agents having similar antioxidant effects are known to exert beneficial effects in ameliorating the injurious effects of hyperglycemia on liver in different diabetic in vitro and in vivo models. The review deals with some of the agents which have been shown to exert protective effects on liver against hyperglycemic insult and the various mechanisms involved. The different classes of agents which protect the diabetic liver or decrease the severity of hyperglycemia mediated injury include flavonoids, catechins, and other polyphenolic compounds, curcumin and its derivatives, certain vitamins, hormones and drugs, trace elements, prototypical antioxidants and amino acids. Some of the pronounced changes mediated by the antioxidants in liver exposed to hyperglycemia include decreased oxidative stress, and alterations in carbohydrate and lipid metabolism. Other mechanisms through which the agents ameliorate hyperglycemia mediated liver injury include decrease in oxidative DNA and protein damage, restoration of mitochondrial structural and functional integrity, decrease in inflammation and improved insulin signaling. Thus, antioxidants may prove to be an important mode of defense in maintaining normal hepatic functions in diabetes.
Collapse
Affiliation(s)
- Aparajita Dey
- Life Science Division, AU-KBC Research Centre, MIT Campus of Anna University, Chromepet, Chennai 600044, India.
| | | |
Collapse
|
5
|
Gvazava IG, Vasiliev AV, Balan OV. Compensatory function of submandibular gland in mice with streptozotocin diabetes under conditions of transplantation. Bull Exp Biol Med 2012; 152:699-702. [PMID: 22803168 DOI: 10.1007/s10517-012-1610-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Transplantation of the submandibular gland under the renal capsule of mice with streptozotocin-induced diabetes mellitus stimulated the compensatory function of the recipient submandibular gland. An increase in insulin I and insulin II gene expression in the submandibular gland after transplantation was demonstrated by PCR. More intensive production and extrusion of these proteins in the apical and basal directions in granular compartment cells of the submandibular gland was confirmed by electron microscopy. All these changes led to a reduction of blood glucose levels in diabetic animals as soon as 2-2.5 weeks after transplantation.
Collapse
Affiliation(s)
- I G Gvazava
- N. K. Koltsov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia.
| | | | | |
Collapse
|
6
|
Newsholme P, Rebelato E, Abdulkader F, Krause M, Carpinelli A, Curi R. Reactive oxygen and nitrogen species generation, antioxidant defenses, and β-cell function: a critical role for amino acids. J Endocrinol 2012; 214:11-20. [PMID: 22547566 DOI: 10.1530/joe-12-0072] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Growing evidence indicates that the regulation of intracellular reactive oxygen species (ROS) and reactive nitrogen species (RNS) levels is essential for maintaining normal β-cell glucose responsiveness. While long-term exposure to high glucose induces oxidative stress in β cells, conflicting results have been published regarding the impact of ROS on acute glucose exposure and their role in glucose stimulated insulin secretion (GSIS). Although β cells are considered to be particularly vulnerable to oxidative damage, as they express relatively low levels of some peroxide-metabolizing enzymes such as catalase and glutathione (GSH) peroxidase, other less known GSH-based antioxidant systems are expressed in β cells at higher levels. Herein, we discuss the key mechanisms of ROS/RNS production and their physiological function in pancreatic β cells. We also hypothesize that specific interactions between RNS and ROS may be the cause of the vulnerability of pancreatic β cells to oxidative damage. In addition, using a hypothetical metabolic model based on the data available in the literature, we emphasize the importance of amino acid availability for GSH synthesis and for the maintenance of β-cell function and viability during periods of metabolic disturbance before the clinical onset of diabetes.
Collapse
Affiliation(s)
- P Newsholme
- School of Biomedical Sciences, Curtin University, PO Box U1987, Perth, Western Australia 6845, Australia.
| | | | | | | | | | | |
Collapse
|
7
|
Long-term enteral arginine supplementation in rats with intestinal ischemia and reperfusion. J Surg Res 2011; 175:67-75. [PMID: 21470625 DOI: 10.1016/j.jss.2011.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 11/23/2010] [Accepted: 02/03/2011] [Indexed: 11/21/2022]
Abstract
BACKGROUND The effects of short-term enteral arginine supplementation on intestinal ischemia-reperfusion (IR) injury have been widely studied, especially the ischemic preconditioning supplementation. The aim of this study was to investigate the effects of long-term intra-duodenal supplementation of arginine on intestinal morphology, arginine-associated amino acid metabolism, and inflammatory responses in rats with intestinal IR. MATERIALS AND METHODS Male Wistar rats with or without three hours of ileal ischemia underwent duodenal cannulation for continuous infusion of formula with 2% arginine or commercial protein powder for 7 d. The serological examinations, plasma amino acid and cytokine profiles, and intestinal morphology were assessed. RESULTS Intestinal IR injury had significant impacts on the decreases in circulating red blood cells, hemoglobin, ileum mass, and villus height and crypt depth of the distal jejunum. In addition, arginine supplementation decreased serum cholesterol and increased plasma arginine concentrations. In rats with intestinal IR injury, arginine supplementation significantly decreased serum nitric oxide, plasma citrulline and ornithine, and the mucosal protein content of the ileum. CONCLUSIONS These results suggest that long-term intra-duodenal arginine administration may not have observable benefits on intestinal morphology or inflammatory response in rats with intestinal ischemia and reperfusion injury. Therefore, the necessity of long-term arginine supplementation for patients with intestinal ischemia and reperfusion injury remains questionable and requires further investigation.
Collapse
|
8
|
Gefen-Halevi S, Rachmut IH, Molakandov K, Berneman D, Mor E, Meivar-Levy I, Ferber S. NKX6.1 promotes PDX-1-induced liver to pancreatic β-cells reprogramming. Cell Reprogram 2011; 12:655-64. [PMID: 21108535 DOI: 10.1089/cell.2010.0030] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Reprogramming adult mammalian cells is an attractive approach for generating cell-based therapies for degenerative diseases, such as diabetes. Adult human liver cells exhibit a high level of developmental plasticity and have been suggested as a potential source of pancreatic progenitor tissue. An instructive role for dominant pancreatic transcription factors in altering the hepatic developmental fate along the pancreatic lineage and function has been demonstrated. Here we analyze whether transcription factors expressed in mature pancreatic β-cells preferentially activate β-cell lineage differentiation in liver. NKX6.1 is a transcription factor uniquely expressed in β-cells of the adult pancreas, its potential role in reprogramming liver cells to pancreatic lineages has never been analyzed. Our results suggest that NKX6.1 activates immature pancreatic markers such as NGN-3 and ISL-1 but not pancreatic hormones gene expression in human liver cells. We hypothesized that its restricted capacity to activate a wide pancreatic repertoire in liver could be related to its incapacity to activate endogenous PDX-1 expression in liver cells. Indeed, the complementation of NKX6.1 by ectopic PDX-1 expression substantially and specifically promoted insulin expression and glucose regulated processed hormone secretion to a higher extent than that of PDX-1 alone, without increasing the reprogrammed cells. This may suggest a potential role for NKX6.1 in promoting PDX-1 reprogrammed cells maturation along the β-cell-like lineage. By contrast, NKX6.1 repressed PDX-1 induced proglucagon gene expression. The individual and concerted effects of pancreatic transcription factors in adult extra-pancreatic cells, is expected to facilitate developing regenerative medicine approaches for cell replacement therapy in diabetics.
Collapse
Affiliation(s)
- Shiraz Gefen-Halevi
- Sheba Regenerative Medicine, Stem cells and Tissue engineering Center , Sheba Medical Center, Tel-Hashomer, Israel
| | | | | | | | | | | | | |
Collapse
|
9
|
Abstract
Regenerative medicine aims at producing new cells for repair or replacement of diseased and damaged tissues. Embryonic and adult stem cells have been suggested as attractive sources of cells for generating the new cells needed. The leading dogma was that adult cells in mammals, once committed to a specific lineage, become "terminally differentiated" and can no longer change their fate. However, in recent years increasing evidence has accumulated demonstrating the remarkable ability of some differentiated cells to be converted into a different cell type via a process termed developmental redirection or adult cells reprogramming. For example, abundant human cell types, such as dermal fibroblasts and adipocytes, could potentially be harvested and converted into other, medically important cell types, such as neurons, cardiomyocytes, or pancreatic beta cells. In this chapter, we describe a method of activating the pancreatic lineage and beta-cells function in adult human liver cells by ectopic expression of pancreatic transcription factors. This approach aims to generate custom-made autologous surrogate beta cells for treatment of diabetes, and possibly bypass both the shortage of cadaveric human donor tissues and the need for life-long immune-suppression.
Collapse
|
10
|
Guo S, Vanderford NL, Stein R. Phosphorylation within the MafA N terminus regulates C-terminal dimerization and DNA binding. J Biol Chem 2010; 285:12655-61. [PMID: 20208071 DOI: 10.1074/jbc.m110.105759] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Phosphorylation regulates transcription factor activity by influencing dimerization, cellular localization, activation potential, and/or DNA binding. Nevertheless, precisely how this post-translation modification mediates these processes is poorly understood. Here, we examined the role of phosphorylation on the DNA-binding properties of MafA and MafB, closely related transcriptional activators of the basic-leucine zipper (b-Zip) family associated with cell differentiation and oncogenesis. Many common phosphorylation sites were identified by mass spectrometry. However, dephosphorylation only precluded the detection of MafA dimers and consequently dramatically reduced DNA-binding ability. Analysis of MafA/B chimeras revealed that sensitivity to the phosphorylation status of MafA was imparted by sequences spanning the C-terminal dimerization region (amino acids (aa) 279-359), whereas the homologous MafB region (aa 257-323) conveyed phosphorylation-independent DNA binding. Mutational analysis showed that formation of MafA dimers capable of DNA binding required phosphorylation within the distinct N-terminal transactivation domain (aa 1-72) and not the C-terminal b-Zip region. These results demonstrate a novel relationship between the phosphoamino acid-rich transactivation and b-Zip domains in controlling MafA DNA-binding activity.
Collapse
Affiliation(s)
- Shuangli Guo
- From the Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | | | | |
Collapse
|
11
|
Juhl K, Bonner-Weir S, Sharma A. Regenerating pancreatic beta-cells: plasticity of adult pancreatic cells and the feasibility of in-vivo neogenesis. Curr Opin Organ Transplant 2010; 15:79-85. [PMID: 19907327 PMCID: PMC2834213 DOI: 10.1097/mot.0b013e3283344932] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW Diabetes results from inadequate functional mass of pancreatic beta-cells and therefore replenishing with new glucose-responsive beta-cells is an important therapeutic option. In addition to replication of pre-existing beta-cells, new beta-cells can be produced from differentiated adult cells using in-vitro or in-vivo approaches. This review will summarize recent advances in in-vivo generation of beta-cells from cells that are not beta-cells (neogenesis) and discuss ways to overcome the limitations of this process. RECENT FINDINGS Multiple groups have shown that adult pancreatic ducts, acinar and even endocrine cells exhibit cellular plasticity and can differentiate into beta-cells in vivo. Several different approaches, including misexpression of transcription factors and tissue injury, have induced neogenesis of insulin-expressing cells in vivo and ameliorated diabetes. SUMMARY Recent breakthroughs demonstrating cellular plasticity of adult pancreatic cells to form new beta-cells are a positive first step towards developing in-vivo regeneration-based therapy for diabetes. Currently, neogenesis processes are inefficient and do not generate sufficient amounts of beta-cells required to normalize hyperglycemia. However, an improved understanding of mechanisms regulating neogenesis of beta-cells from adult pancreatic cells and of their maturation into functional glucose-responsive beta-cells can make therapies based on in-vivo regeneration a reality.
Collapse
Affiliation(s)
- Kirstine Juhl
- Section of Islet Transplantation and Cell Biology, Joslin Diabetes Center, Boston, Massachusetts 02215, USA
| | | | | |
Collapse
|
12
|
Yi J, Horky LL, Friedlich AL, Shi Y, Rogers JT, Huang X. L-arginine and Alzheimer's disease. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2008; 2:211-38. [PMID: 19079617 PMCID: PMC2600464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Accepted: 09/10/2008] [Indexed: 05/27/2023]
Abstract
Alzheimer's disease (AD), the most common form of dementia, is characterized by progressive neurodegeneration and loss of cognitive and memory functions. Although the exact causes of AD are still unclear, evidence suggests that atherosclerosis, redox stress, inflammation, neurotransmitter dysregulation, and impaired brain energy metabolism may all be associated with AD pathogenesis. Herein, we explore a possible role for L-arginine (L-arg) in AD, taking into consideration known functions for L-arg in atherosclerosis, redox stress and the inflammatory process, regulation of synaptic plasticity and neurogenesis, and modulation of glucose metabolism and insulin activity. L-arg, a precursor of nitric oxide and polyamine, exhibits multiple functions in human health and may play a prominent role in age-related degenerative diseases such as AD.
Collapse
Affiliation(s)
- Jing Yi
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical SchoolCharlestown, MA 02129, USA
| | - Laura L. Horky
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Brigham and Women's Hospital and Harvard Medical SchoolBoston, MA 02115, USA
| | - Avi L. Friedlich
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical SchoolCharlestown, MA 02129, USA
| | - Ying Shi
- Conjugate and Medicinal Chemistry Laboratory, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Brigham and Women's Hospital and Harvard Medical SchoolBoston, MA 02115, USA
| | - Jack T. Rogers
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical SchoolCharlestown, MA 02129, USA
| | - Xudong Huang
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical SchoolCharlestown, MA 02129, USA
- Conjugate and Medicinal Chemistry Laboratory, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Brigham and Women's Hospital and Harvard Medical SchoolBoston, MA 02115, USA
| |
Collapse
|
13
|
Abstract
Production and secretion of insulin from the β-cells of the pancreas is very crucial in maintaining normoglycaemia. This is achieved by tight regulation of insulin synthesis and exocytosis from the β-cells in response to changes in blood glucose levels. The synthesis of insulin is regulated by blood glucose levels at the transcriptional and post-transcriptional levels. Although many transcription factors have been implicated in the regulation of insulin gene transcription, three β-cell-specific transcriptional regulators, Pdx-1 (pancreatic and duodenal homeobox-1), NeuroD1 (neurogenic differentiation 1) and MafA (V-maf musculoaponeurotic fibrosarcoma oncogene homologue A), have been demonstrated to play a crucial role in glucose induction of insulin gene transcription and pancreatic β-cell function. These three transcription factors activate insulin gene expression in a co-ordinated and synergistic manner in response to increasing glucose levels. It has been shown that changes in glucose concentrations modulate the function of these β-cell transcription factors at multiple levels. These include changes in expression levels, subcellular localization, DNA-binding activity, transactivation capability and interaction with other proteins. Furthermore, all three transcription factors are able to induce insulin gene expression when expressed in non-β-cells, including liver and intestinal cells. The present review summarizes the recent findings on how glucose modulates the function of the β-cell transcription factors Pdx-1, NeuroD1 and MafA, and thereby tightly regulates insulin synthesis in accordance with blood glucose levels.
Collapse
|