Review Article, J Regen Med Vol: 10 Issue: 5

Long Term Preservation of Human Pancreatic Slices as a Model to Analyse Different Therapeutic Development For Pancreatic Islets Regeneration

Sagorika Rai^*

Department of Pathology, New Industrial Town Faridabad, India

Corresponding Author: Sagorika Rai
Department of Pathology, New Industrial Town Faridabad, India
Tel: 8368177839
E-mail: Sagorikarai2@gmail.com

Received: July 17, 2021 Accepted: August 12, 2021 Published: August 17, 2021

Citation: Rai S (2021) Long Term Preservation of Human Pancreatic Slices as a Model to Analyse Different Therapeutic Development for Pancreatic Islets Regeneration. J Regen Med 10:5.

Abstract

Keywords: Pancreatic islets regeneration, Endocrine and exocrine pancreas, Cytoarchitecture, Diabetes, HPSs, Beta-cells, Therapeutic development, Pluripotent stem cells

Introduction

The recognition of procedure to section, stabilize and culture cuts of live pancreatic tissue shows a subjective leap in our capacity to analyse the function and biology of the pancreas. This in vitro situation conserves a great part of the cytoarchitecture of the organ, taking into consideration the dynamic investigation of islet physiology and the connections between neural, exocrine, vascular, endocrine and the immune cells in anatomical conditions [1-5].

Exocrine acinar cells makes a variety of stomach related digestive enzymes, including proteinases, amylases and lipases which produced into the pancreatic ducts and stream in the small intestine system to separate sugars, protein and fats for ingestion. Endocrine islets shows fewer than 5% of entire pancreatic mass other than however number in excess of a billion cells in people. Every five most important kind of islet cell secretes a code hormone: glucagon (α-cells), insulin (β-cells), pancreatic polypeptide (PP cells), ghrelin (ε-cells) and somatostatin (δ-cells).

Pancreatic and Pancreatitis tumour, most commonly includes ductal carcinomas, start from the exocrine islet whereas the diabetes and uncommon pancreatic neuroendocrine cancer emerge from endocrine islets. Diabetes has been evaluated to suffering well more than the 300 million individuals worldwide and is a significant and developing medical health issue in the present world [6].

Most of diabetic patients experience the ill property of the type 2 diabetes (T2D), an disorder ascribed to insulin opposition by fringe organs including muscle, fat and liver. Ongoing hereditary linkage analyse and histological investigations have confirmed that patients with the T2D likewise have essentially less islet β-cells than the healthy people [7-10]. Type 1diabetes (T1D), which is around 5–10% of all diabetes related cases, is a autoimmune system illness wherein β-cells are specifically damaged, prompting an extreme insulin lack that should be cured with the every day insulin infusions for endurance. Together, these sicknesses represent an enormous and developing patient populace with β-cell insufficiency in pancreas [6].

The endemic of diabetes in current decades has prodded various investigations on the pancreas homeostasis, development and recovery. Animal investigations have proposed that the exocrine pancreas has an inherent capability for fastest regeneration and in this way can make a quick and full recuperation from the exocrine disorders, for example, intense pancreatitis [11]. Also, endocrine islets have restricted regenerative capability in the adult people. In fact, it stays indistinct whether the adult people pancreas can immediately recover β-cells in every physiologically significant manner. β-cell insufficiency consequently shows irreversible diabetes and endocrine insufficiency. There is an rising accord that a regenerative medication method will be very useful, even vital, for the cure of the certain types of diabetes involving T1D and perhaps the seperation of T2D in which the considerable β-cell insufficiency [6]. Figuring out how to improve or prompt the essential regenerative capacity of endocrine islets and contriving new ideas to create insulin-emitting β-cells will have significant suggestions for creating therapeutic cure for diabetes patients. Here we sum up our present comprehension of pancreatic exocrine and endocrine recovery and also review the various strategies for the therapeutic recovery and regeneration.

Different Injury Models That Used To Examine Pancreatic Regeneration

Pancreatectomy (Px)

Pancreatectomey is the most tested model which is utilized to analyze the regenerative capability of the pancreas [12]. Pancreatectomey model is utilized to examine β-cell recuperation and acinar in the both mice and rats; though since account of the expanded islet mass this model has been widely used to contemplate β-cell recovery [13-15]. Pancreatectomy (PPx) includes resection of under 90% (frequently 50-75%) of the mature mouse or rodent pancreas [15,16].

In Px, expulsion of about 90% of rodent pancreas doesn't influence glucose homeostasis, recommending a huge save capability, as 10% of islet mass is adequate to keep up blood glucose manage [17] Other side, resection of the 50%-60% of pancreas in people suffers insulin- dependent diabetes [18,19]. Mature mouse show growing and tissue development from cut surface after the pancreatectomy [17]. By investigating the rare samples from young child also recommend tissue development after the pancreatectomy [20]. The ability with respect to this kind of recovery, nonetheless decreases sharply in young animals and is missing in young humans [19,21].

Pancreatic duct ligation (PDL)

Pancreatic ductal ligation and obstruction have verifiably been utilized in examining pancreatic recovery [12]. PDL includes in the ligation of one of the most important ducts, which prompts acinar cell loss and inflammation in distal region to ligation. A main benefit with PDL is the unligated segment of pancreas stays unaffected, and subsequently can be utilized as an internal control. Nevertheles, the regenerative procedure in the model, especially the regeneration of acinar, seems to be species dependent. Pancreatic duct ligation in rodents is related with close to finish acinar regeneration through a procedure that includes appearance of the ductular structures, and their separation into the acinar cells [22,23]. In rodents, even though PDL shows result in the arrangement of relative metaplastic ducts, the acinar section doesn't recover [23,24]. Heredity following investigations in rodents show that both enduring acinar cells and Hnf1β- communicating duct cells [24] in the ligated portion of pancreas can include to the growth of ductular structures. PDL has been fundamentally used to give bits of knowledge on islet β-cell period as it is accounted to stimulate the β-cell recovery in both mouse and rodent [22,23]. This PDL model is clinically helpful in assessing the adequacy of medications for pancreatitis and examining systems of multiorgan malfunction while the clinical situation is steady with that in people by ideals of its closely resembling pancreaticobiliary ductal life analysis.

Caerulein-induced pancreatitis

Pancreatitis instigated by cerulein is most generally utilized investigational animal model of severe pancreatitis. This model is extremely economical and reproducible since it uses rodents or mice. The model has been utilized broadly into the research settings, and the pathogenesis of the severe pancreatitis instigated by this type of agents is subsequently very well understood [25,26].

Severe pancreatitis can be actuated by an intraperitoneal or intravenous infusion of an overdose of the cerulean, that is, 5 µg/kg/hr into the rodents and 50 µg/kg a few times at hourly gap in mice. As indicated by past investigations, cerulein is known to prompt pancreatic catalyst activation inside 30 minutes of intravenous organization [27]. Numerous discoveries practically identical to those of counting hyperamylasemia and assorted histopathological discoveries: penetration of the inflammatory cells inside the pancreas, acinar cell vacuolization, pancreatic edema and the occurance of the activated pancreatic catalyst inside the pancreas [26]. separately from the injury to acinar cells, endocrine and ductal cells are not harmed. Also, cerulein-actuated pancreatitis totally settle after cerulein is pulled back [27]. As the histopathological discoveries in cerulein-induced severe pancreatitis directly look like those of severe pancreatitis in people, and is generally used to contemplate the pathogenesis of intense pancreatitis in conditions of the intracellular enzymatic activation and systematic mechanism of inflammatory cell invasion.

Alloxan or streptozotocin-induced diabetes

Alloxan and streptozotocin (STZ) are utilized to induce diabetes by the chemical removal of pancreatic β-cells. Alloxan was first depicted in mid 1800, yet its diabetogenic property was accounted for in 1943, and from that point forward alloxan treatment has been utilized as an examining model for the diabetes [28]. STZ was the first utilized as a chemotherapeutic operator in pancreatic islet cell tumours and different malignancies [29], however since its findings as diabetogenic agent in the 1963, it is generally utilized in diabetes study [30]. STZ and alloxan are both harmful glucose analogs that specially collect in insulin creating β-cells by means of the Glut2 glucose carrier [29]. Diabetes as the consequence of the STZ and alloxan treatment isn't related with β-cell regeneration [28,31]. Due to the lack of the spontaneous β-cell recuperation, these type of models have been very valuable apparatuses to investigate a given treatment on β- cell recovery. Also, alloxan-or STZ-treatment can be joined with the pancreatic PDL to consider the impact of hyperglycemia on regenerative procedure into the ligated segment of the pancreas [32-34]. Here, while the grouping of STZ or Alloxan treatment and PDL in rats prompted change of acinar cells or glucagon-creating α-cells into β-cells [33,34], no such α-to β- cell transformation could be discovered when rodents were exposed to a joined STZ or PDL- treatment [32].

Diphtheria toxin-mediated cell ablation

A new technique which empowers cell-specific removal is transgenic enactment of diphtheria poison cell death path utilizing a cell-specific promoter [35,36]. DT receptor (DTR) is membrane- anchored type of heparin bound EGF-like development factor (HB-EGF forerunner) [37]. The simian and human HB-EGF forerunners bind DT and role as the toxin receptors, though HB- EGF from rodents and mice don't tie up with the toxin and in this manner stay insensitive toward DT [38]. As a result, transgenic articulation of simian or human DTR in rats can deliver normally DT-resistant mouse cells DT-delicate [39-41]. Newly, a rodent strain was created (R26DTR), in which loxP-flanked STOP cassette and ORF of simian DTR had been brought into ROSA26 locus [42]. In R26DTR strain, the genetic material encoding DTR is in control by the strong Rosa promoter, however DTR articulation is reliant first on Cre-recombinase expulsion of STOP the cassette [42]. Importantly, the HB-EGF is not fpr the long term activation as EGFR ligand, as transgenic lines shows DTR in various pancreatic genealogies don't show any atypical phenotype [43,44]. In the young pancreas, DTR/DTA-interceded β-cell removal has been utilized to contemplate recovery following α-or β-cell exact losses[43-48], acinar and endocrine cell removal [43,44].

Different Types of Strategies to Create New Endocrine Islet Cells

Most of studies on pancreas recovery have concentrated on the endocrine islets, attributable to their focal significance in diabetes. Many years of clinical investigations have set up that the cadaveric islet transplantation can be useful in the patients with T1D, with certain patients staying liberated from the insulin use for many years [49,50]. However, clinical cadaveric islet transplantation is utilized just on the small level due to the lack of appropriate cadaveric islets and the necessity for long lasting immune suppression concealment to fight allo-and autoimmunity. To treat bigger populaces of the patients, it is helpful to have a dependable and normalized wellspring of human islets for the transplantation, without the requirement for the immune suppression [6]. Other side, therapeutic intercessions that stimulates the endogenous islet recovery could be utilized. In the response of the huge unmet clinical need, a few examination endeavors are presently in progress to assess techniques to create new islets in vitro or stimulate the islet recovery in vivo [6].

Self-replication maintains the β-cell mass

The proliferative pace of β-cells is very high in youthful mouse, however decline quickly with the age [51,52]. For instance, one investigation assessed a multiplication pace of around 4% every day in a one-month-old rodents and 0.5% every day in the seven-month old rodents [53].

Furthermore, checked islet hyperplasia can be induced into the young animal by obesity or pregnancy. In an achievement study, genetic hereditary genealogy following in mice utilizing β-cell-specified drivers demonstrated that main methadology for β-cell recharging in after injury or homeostasis was replication of prior β-cells [54]. The function of replication is substantially less clear in the human being, as very small numbers of replicating human β-cells can be found in pancreas tests samples taken during post-mortem of fit or strong, pregnant, injured or over weighted young humans [55,56].

Separation of the pluripotent stem cells

Many years of developmental investigations in fish, mice and frog have outlined the essential advances and important signalling actions that lead from the fertilized egg to the arrangement of develop islets in the early childhood [57-59]. This profound comprehension of pancreatic advancement was put to the administration of the regenerative medication in 1998, when the embryonic stem cells of the human (hES cells) were effectively cultured and made the way for creating strategies for getting pancreatic islets from hES cells [60].

In the primary significant investigations of getting pancreatic endocrine cells from the hES cells, a step-wise procedure was developed utilizing blends of signalling particles to manage hES cell separation through four progressive stages (β-like cells, pancreatic epithelium, definitive endoderm, endocrine progenitors) [61,62]. The primary separations of human stem cells into islet cells formed a populace of cells with blended hormone expression, yet not true or mature human β-cells [61]. These examinations, along with the many years of cellular and genetic Hereditary investigations of pancreatic improvement into the animal models, made an outline for in vitro differentiation conventions that directly applied to pluripotent undifferentiated cells.

Redifferentiating β-cells

Pancreatic β-cells turn into dysfunctional under an assortment of stress situation, for example, prolonged hyperlipidaemia (T2D) and hyperglycaemia, pancreatic inflammation because of pancreatic cancer or chronic pancreatitis (type 3c diabetes), or immune system induced inflammation(T1D). Excessive pain could prompt down-regulation and degranulation of β-cell genes. Current investigations have recommended that loss of β-cell properties may shows dedifferentiation described by upregulation of the genes that are normally showed in early stage embryonic islet progenitors, (for example, Neurog3) [63]. It is not clear whether dedifferentiation is a ordinary trait of not working β-cells, and whether dedifferentiation procedure, if that it exists in the human, can be switched. We do realize that the disfunctional β-cells can recuperate in patients with the T2D with very proper system, for example, exercise, diet or intensive insulin treatment. If the pharmacological methods means can be create to 'redifferentiate' the dedifferentiated β-cells, it could comprise another restorative methodology for diabetes and might be seen as an different kind of regenerative treatmen [64]. This treatment would be generally important for the T2D however could possibly be useful for beginning phase T1D too.

Conclusion

Pancreatic recovery depends on a perplexing communication between the cells that give vital recovery signals and cells that are responsive to those the signs. As talked about here, the level, nature and the seriousness of injury are three significant boundaries that decide whether recuperation is accomplished. β-cell recovery is shown to be more delicate to the idea of injury than the acinar recovery. At long last, the level of the injury figures out which cell types would react to these regenerative signs.

References

1. Ivanova A, Kalaidzidis Y, Dirkx R, Sarov M, Gerlach M, et al. (2013) Age-dependent labeling and imaging of insulin secretory granules. Diabetes 62(11): 3687-3696.
2. Marciniak A, Selck C, Friedrich B, Speier S (2013) Mouse pancreas tissue slice culture facilitates long-term studies of exocrine and endocrine cell physiology in situ. PloS one 8(11): 78706
3. Rodriguez-Diaz  R, Speier S, Molano RD, Formoso A, Gans I, et al. (2012) Noninvasive in vivo model demonstrating the effects of autonomic innervation on pancreatic islet function. Proc Natl Acad Sci 109(52): 21456-21461
4. Almaça J, Weitz J, Rodriguez-Diaz R, Pereira E, Caicedo A (2018) The pericyte of the pancreatic islet regulates capillary diameter and local blood flow. Cell metab 27(3): 630-644.
5. Weitz JR, Makhmutova M, Almaça J, Stertmann J, Aamodt K, et al. (2018) Mouse pancreatic islet macrophages use locally released ATP to monitor beta cell activity. Diabetologia 61(1): 182-192.
6. Zhou Q, Melton DA (2018) Pancreas regeneration. Nature 557(7705): 351-358.
7. McCarthy MI (2010) Genomics, type 2 diabetes, and obesity. N Engl J Med 363(24): 2339-235.
8. Flannick J, Florez JC (2016) Type 2 diabetes: genetic data sharing to advance complex disease research. Nature Reviews Nat Rev Genet 17(9): 535-49.
9. Butler AE, Janson J, Bonner-Weir S, Ritzel R, Rizza RA, et al. (2003) β-cell deficit and increased β-cell apoptosis in humans with type 2 diabetes. Diabetes 52(1): 102-110
10. Rahier J, Guiot Y, Goebbels RM, Sempoux C, Henquin JC (2008) Pancreatic β�?�cell mass in European subjects with type 2 diabetes. Diabetes, Obes Metab 10: 32-42
11. Slack JM (1995) Developmental biology of the pancreas. Development. 121(6): 1569-1580.
12. Weaver CV, Garry DJ (2008) Regenerative biology: a historical perspective and modern applications. Regen Med 3(1): 63-82
13. Bonner�?�Weir S, Toschi E, Inada A, Reitz P, Fonseca SY, et al. (2004) The pancreatic ductal epithelium serves as a potential pool of progenitor cells. Pediatric diabetes 5: 16-22.
14. Brockenbrough JS, Weir GC, Bonner-Weir S (1988) Discordance of exocrine and endocrine growth after 90% pancreatectomy in rats. Diabetes 37(2): 232-236.
15. De Leon DD, Deng S, Madani R, Ahima RS, Drucker DJ, et al. (2003) Role of endogenous glucagon-like peptide-1 in islet regeneration after partial pancreatectomy. Diabetes 52(2): 365-371.
16. Dor Y, Brown J, Martinez OI, Melton DA (2004) Adult pancreatic β-cells are formed by self- duplication rather than stem-cell differentiation. Nature 429(6987): 41-46
17. Lehv M, Fitzgerald PJ (1968) Pancreatic acinar cell regeneration. IV. Regeneration after resection. Am J Pathol 53(4): 513.
18. Kumar AF, Gruessner RW, Seaquist ER (2008) Risk of glucose intolerance and diabetes in hemipancreatectomized donors selected for normal preoperative glucose metabolism. Diabetes Care 31(8): 1639-1643
19. Menge BA, Tannapfel A, Belyaev O, Drescher R, Müller C, et al. (2008) Partial pancreatectomy in adult humans does not provoke β-cell regeneration. Diabetes 57(1): 142-149
20. Berrocal T, Luque AA, Pinilla I (2005) Pancreatic regeneration after near-total pancreatectomy in children with nesidioblastosis. Pediatr Radiol 35(11): 1066-1070
21. Rankin MM, Kushner JA (2009) Adaptive β-cell proliferation is severely restricted with advanced age. Diabetes 58(6): 1365-1372
22. Meier JJ, Bhushan A, Butler PC (2006) The potential for stem cell therapy in diabetes. Pediatric research 59(4): 65-73.
23. Cavelti-Weder C, Shtessel M, Reuss JE, Jermendy A, Yamada T, et al., (2013) Pancreatic duct ligation after almost complete β- cell loss: exocrine regeneration but no evidence of β-cell regeneration. Endocrinology 154(12): 4493-4502.
24. Solar M, Cardalda C, Houbracken I, Martín M, Maestro MA, et al. (2009) Pancreatic exocrine duct cells give rise to insulin- producing β cells during embryogenesis but not after birth. Dev Cell 17(6): 849-860.
25. Lampel M, Kern HF (1977) Acute interstitial pancreatitis in the rat induced by excessive doses of a pancreatic secretagogue. Virchows Archiv. A Pathol Anat Histol 373(2): 97-117
26. Saluja A, Saito I, Saluja M, Houlihan MJ, Powers RE, et al. (1985) In vivo rat pancreatic acinar cell function during supramaximal stimulation with caerulein. Am J Physiol 249(61): 702-710.
27. Hyun JJ, Lee HS (2014) Experimental models of pancreatitis. Clinical endoscopy 47(3): 212-216.
28. Szkudelski T (2001) The mechanism of alloxan and streptozotocin action in B cells of the rat pancreas. Physiol res 50(6): 537-546.
29. Lenzen S (2008) The mechanisms of alloxan-and streptozotocin-induced diabetes. Diabetologia 51(2): 216- 226.
30. Eleazu CO, Eleazu KC, Chukwuma S, Essien UN (2013) Review of the mechanism of cell death resulting from streptozotocin challenge in experimental animals, its practical use and potential risk to humans. J Diabetes Meta Disorders 12(1): 60.
31. Xiao X, Chen Z, Shiota C, Prasadan K, Guo P, et al. (2013) No evidence for β cell neogenesis in murine adult pancreas. J Clin Invest 123(5): 2207-2217.
32. Cavelti-Weder C, Shtessel M, Reuss JE (2013) Pancreatic duct ligation after almost complete β- cell loss: exocrine regeneration but no evidence of β-cell regeneration. Endocrinology 154(12): 4493-4502
33. Chung CH, Hao E, Piran R, Keinan E (2010) Pancreatic β�?�cell neogenesis by direct conversion from mature α�?�cells. Stem Cells 28(9): 1630- 1638.
34. Pan FC, Bankaitis ED, Boyer D (2013) Spatiotemporal patterns of multipotentiality in Ptf1a-expressing cells during pancreas organogenesis and injury-induced facultative restoration. Development 140(4): 751-764.
35. Breitman ML, Clapoff S, Rossant J (1987) Genetic ablation: targeted expression of a toxin gene causes microphthalmia in transgenic mice. Science 238(4833): 1563-1565.
36. Palmiter RD, Behringer RR, Quaife CJ, Maxwell F, Maxwell IH et al. (1987) Cell lineage ablation in transgenic mice by cell-specific expression of a toxin gene. Cell 50(3): 435-443.
37. Naglich JG, Metherall JE, Russell DW, Eidels L (1992) Expression cloning of a diphtheria toxin receptor: Identity with a heparin-binding EGF-like growth factor precursor. Cell 69(6): 1051-1061.
38. Mitamura T, Higashiyama S, Taniguchi N, Klagsbrun M, Mekada E (1995) Diphtheria toxin binds to the epidermal growth factor (EGF)-like domain of human heparin-binding EGF-like growth factor/diphtheria toxin receptor and inhibits specifically its mitogenic activity. J Biol Chem 270(3): 1015-1019.
39. Cha JH, Chang MY, Richardson JA, Eidels L (2003) Transgenic mice expressing the diphtheria toxin receptor are sensitive to the toxin. Mol Microbiol 49(1): 235-240.
40. Jung S, Unutmaz D, Wong P, Sano GI, De los Santos K, et al. (2002) In vivo depletion of CD11c+ dendritic cells abrogates priming of CD8+ T cells by exogenous cell-associated antigens. Immunity 17(2): 211-220.
41. Saito M, Iwawaki T, Taya C, Yonekawa H, Noda M, et al. (2001) Diphtheria toxin receptor–mediated conditional and targeted cell ablation in transgenic mice. Nat Biotechnol. 19(8): 746-750.
42. Buch T, Heppner FL, Tertilt C, Heinen TJ, Kremer M, et al. (2005) A Cre-inducible diphtheria toxin receptor mediates cell lineage ablation after toxin administration. Nat Methods 2(6): 419-426.
43. Criscimanna A, Coudriet GM, Gittes GK, Piganelli JD (2014) Activated macrophages create lineage-specific microenvironments for pancreatic acinar-and β-cell regeneration in mice. Gastroenterology 147(5): 1106-1118.
44. Criscimanna A, Speicher JA, Houshmand G, Shiota C, Prasadan K, et al. (2011) Duct cells contribute to regeneration of endocrine and acinar cells following pancreatic damage in adult mice. Gastroenterology 141(4): 1451-1462
45. Chera S, Baronnier D, Ghila L, Cigliola V, Jensen JN, et al. (2014) Diabetes recovery by age-dependent conversion of pancreatic δ- cells into insulin producers. Nature 514(7523): 503-507.
46. Nir T, Melton DA, Dor Y (2007) Recovery from diabetes in mice by β cell regeneration. J Clin Invest 117(9) 2553-2561
47. Shiota C, Prasadan K, Guo, P, El-Gohary, Y, Wiersch J, et al. (2013) α-Cells are dispensable in postnatal morphogenesis and maturation of mouse pancreatic islets. American J Physiol Endocrinol Metab 305(8): 1030-1040.
48. Thorel F, Herrera PL (2010) Conversion of adult pancreatic alpha-cells to beta-cells in diabetic mice. Med sci 26(11): 906.
49. Lakey JR, Mirbolooki M, Shapiro AJ (2006) Current status of clinical islet cell transplantation. In Transplantation Immunology 47-103.
50. Hering BJ, Clarke WR, Bridges ND, Eggerman TL, Alejandro R, et al. (2016) Phase 3 trial of transplantation of human islets in type 1 diabetes complicated by severe hypoglycemia. Diabetes Care 39(7): 1230-1240.
51. Finegood DT, Scaglia L, Bonner-Weir S (1995) Dynamics of β-cell mass in the growing rat pancreas: estimation with a simple mathematical model. Diabetes 44(3): 249-256.
52. Teta M, Long SY, Wartschow LM, Rankin MM (2005) Very slow turnover of β-cells in aged adult mice. Diabetes 54(9): 2557-2567.
53. Montanya E, Nacher V, Biarnés M, Soler J (2000) Linear correlation between beta-cell mass and body weight throughout the lifespan in Lewis rats: role of beta-cell hyperplasia and hypertrophy. Diabetes 49(8): 1341-1346.
54. Dor Y, Brown J, Martinez OI, Melton DA (2004) Adult pancreatic β-cells are formed by self- duplication rather than stem-cell differentiation. Nature 429(6987): 41-46.
55. Menge BA, Tannapfel A, Belyaev O, Drescher R, Müller C, et al. (2008) Partial pancreatectomy in adult humans does not provoke β-cell regeneration. Diabetes 57(1): 142-149.
56. Saisho Y, Butler AE, Manesso E, Elashoff D, Rizza RA, et al. (2013) β-cell mass and turnover in humans: effects of obesity and aging. Diabetes Care 36(1): 111-117.
57. Arda HE, Benitez CM, Kim SK (2013) Gene regulatory networks governing pancreas development. Dev Cell 25(1): 5-13.
58. McCracken KW, Wells JM (2012) Molecular pathways controlling pancreas induction. Semin Cell Dev Biol 23(6): 656-662.
59. Murtaugh LC, Melton DA (2003) Genes, signals, and lineages in pancreas development. Annu Rev Cell Dev Biol 19(1): 71-89.
60. Thomson JA, Itskovitz-Eldor J, Shapiro SS, Waknitz MA, Swiergiel JJ, et al. (1998) Embryonic stem cell lines derived from human blastocysts. science 282(5391) 1145-1147.
61. Damour KA, Bang AG, Eliazer S, Kelly OG, Agulnick AD, et al. (2006) Production of pancreatic hormone–expressing endocrine cells from human embryonic stem cells. Nat Biotechnol 24(11): 1392-1401.
62. Kroon E, Martinson LA, Kadoya K, Bang AG, Kelly OG, et al. (2008) Pancreatic endoderm derived from human embryonic stem cells generates glucose-responsive insulin-secreting cells in vivo. Nat Biotechnol 26(4): 443-452.
63. Talchai C, Xuan S, Lin HV, Sussel L (2012) Pancreatic β cell dedifferentiation as a mechanism of diabetic β cell failure. Cell 150(6): 1223- 1234.
64. Accili D, Talchai SC, Kim Muller J, Cinti F, Ishida E, et al. (2016) When β�?�cells fail: lessons from dedifferentiation. Diabetes Obes Metab 18: 117-122.