scholarly journals The Role of Vascular Cells in Pancreatic Beta-Cell Function

2021 ◽  
Vol 12 ◽  
Author(s):  
Guzel Burganova ◽  
Claire Bridges ◽  
Peter Thorn ◽  
Limor Landsman
Keyword(s):  
Endothelial Cells ◽  
Cell Function ◽  
Pancreatic Beta Cell ◽  
Cell Activity ◽  
Vascular Cells ◽  
Β Cells ◽  
Β Cell ◽  
Key Factor ◽  
Insulin Gene Expression ◽  
Pancreatic Beta Cell Function

Insulin-producing β-cells constitute the majority of the cells in the pancreatic islets. Dysfunction of these cells is a key factor in the loss of glucose regulation that characterizes type 2 diabetes. The regulation of many of the functions of β-cells relies on their close interaction with the intra-islet microvasculature, comprised of endothelial cells and pericytes. In addition to providing islet blood supply, cells of the islet vasculature directly regulate β-cell activity through the secretion of growth factors and other molecules. These factors come from capillary mural pericytes and endothelial cells, and have been shown to promote insulin gene expression, insulin secretion, and β-cell proliferation. This review focuses on the intimate crosstalk of the vascular cells and β-cells and its role in glucose homeostasis and diabetes.

scholarly journals Differences between studying an islet β cell and studying whole pancreatic islets: immunological implications

2016 ◽  
Vol 1 (2) ◽  
Keyword(s):  
Endothelial Cells ◽  
Cell Function ◽  
Cell Types ◽  
Main Role ◽  
Β Cells ◽  
Β Cell ◽  
Exciting Field ◽  
Patients With Diabetes ◽  
Β Cell Function ◽  
Paracrine Interaction

The main role of the pancreatic islet β cell is to release the appropriate amount of insulin upon glucose stimulation. For this reason, islet transplantation has been advancing in the past few years as a therapeutic alternative for patients with diabetes, alongside the exciting field of manipulating β cell differentiation for the sake of β cell transplantation. However, do isolated β cells function the same as β cells within an intact islet? Within islets, β cells are surrounded by other cell types, including endocrine cells, endothelial cells and immune cells, a proximity which appears to be relevant for proper glucose homeostasis. Although insulin and glucose are the main regulators in this scenario, other factors, such as angiogenesis, local anti-inflammatory components and the activity profile of resident macrophages, have a profound effect on the function and fate of β cells. A paracrine interaction between β cells and α cell holds a dramatic effect on β cell function, which is additionally dependent on blood flow through the islet. Another important intercellular communication exists between β cells and endothelial cells, in this case a bidirectional interface. Moreover, β cell survival and proliferation is dependent on the potency of ECM proteins. Further parameters distinguish functionally between the isolated β cell and the intact islet, including the deposition of Zinc by β cells, synchronicity by electrical and calcium routes, the physical innervation of islets and more. In this review, we explore major parameters that relate to differences between the function of the isolated β cell and that of the β cell within an intact islet. These and some yet to be investigated aspects of β cell function should be included in the list of considerations when examining therapeutic targets for β cell–related pathologies and for the prospect of effective β cell replacement therapy

scholarly journals The MAFB transcription factor impacts islet α-cell function in rodents and represents a unique signature of primate islet β-cells

2016 ◽  
Vol 310 (1) ◽  
pp. E91-E102 ◽  
Author(s):  
Elizabeth Conrad ◽  
Chunhua Dai ◽  
Jason Spaeth ◽  
Min Guo ◽  
Holly A. Cyphert ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Neural Development ◽  
Cell Function ◽  
Cell Activity ◽  
Cell Formation ◽  
Glucagon Secretion ◽  
Β Cells ◽  
Β Cell ◽  
Physiological Impact ◽  
Unique Signature

Analysis of MafB−/− mice has suggested that the MAFB transcription factor was essential to islet α- and β-cell formation during development, although the postnatal physiological impact could not be studied here because these mutants died due to problems in neural development. Pancreas-wide mutant mice were generated to compare the postnatal significance of MafB ( MafB Δpanc) and MafA/B ( MafAB Δpanc) with deficiencies associated with the related β-cell-enriched MafA mutant (MafA Δpanc). Insulin+ cell production and β-cell activity were merely delayed in MafB Δpanc islets until MafA was comprehensively expressed in this cell population. We propose that MafA compensates for the absence of MafB in MafB Δpanc mice, which is supported by the death of MafAB Δpanc mice soon after birth from hyperglycemia. However, glucose-induced glucagon secretion was compromised in adult MafB Δpanc islet α-cells. Based upon these results, we conclude that MafB is only essential to islet α-cell activity and not β-cell. Interestingly, a notable difference between mice and humans is that MAFB is coexpressed with MAFA in adult human islet β-cells. Here, we show that nonhuman primate (NHP) islet α- and β-cells also produce MAFB, implying that MAFB represents a unique signature and likely important regulator of the primate islet β-cell.

scholarly journals Lipid droplets protect human β cells from lipotoxic-induced stress and cell identity changes

2021 ◽  
Author(s):  
Xin Tong ◽  
Roland W Stein
Keyword(s):  
Er Stress ◽  
Cell Function ◽  
Cell Activity ◽  
Cell Types ◽  
Human Cell Line ◽  
Human Islet ◽  
Structural Protein ◽  
Β Cells ◽  
Β Cell ◽  
Β Cell Function

Free fatty acids (FFAs) are often stored in lipid droplet (LD) depots for eventual metabolic and/or synthetic use in many cell types, such a muscle, liver, and fat. In pancreatic islets, overt LD accumulation was detected in humans but not mice. LD buildup in islets was principally observed after roughly 11 years of age, increasing throughout adulthood under physiologic conditions, and also enriched in type 2 diabetes. To obtain insight into the role of LDs in human islet β cell function, the levels of a key LD structural protein, perilipin2 (PLIN2), were manipulated by lentiviral-mediated knock-down (KD) or over-expression (OE) in EndoCβH2-Cre cells, a human cell line with adult islet β-like properties. Glucose stimulated insulin secretion was blunted in PLIN2KD cells and improved in PLIN2OE cells. An unbiased transcriptomic analysis revealed that limiting LD formation induced effectors of endoplasmic reticulum (ER) stress that compromised the expression of critical β cell function and identity genes. These changes were aggravated by exogenous treatment with FFAs toxic to islet β cells, and essentially reversed by PLIN2OE or using the ER stress inhibitor, tauroursodeoxycholic acid. These results strongly suggest that LDs are essential for adult human islet β cell activity by preserving FFA homeostasis.

970-P: Comparative Assessment of the Effect of Vildagliptin and Metformin on Pancreatic Beta-Cell Function and Insulin Sensitivity in Newly Diagnosed Asian Indians with Type 2 Diabetes

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 970-P
Author(s):  
KRISHNAMOORTHY SATHEESH ◽  
CHAMUKUTTAN SNEHALATHA ◽  
ARUN NANDITHA ◽  
ARUN RAGHAVAN ◽  
RAMACHANDRAN VINITHA ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Insulin Sensitivity ◽  
Beta Cell Function ◽  
Asian Indians ◽  
Cell Function ◽  
Pancreatic Beta Cell ◽  
Comparative Assessment ◽  
Newly Diagnosed ◽  
Pancreatic Beta Cell Function

Compensation in pancreatic beta-cell function in subjects with glucokinase mutations

Diabetes ◽  
1994 ◽  
Vol 43 (5) ◽  
pp. 718-723 ◽  
Author(s):  
J. Sturis ◽  
I. J. Kurland ◽  
M. M. Byrne ◽  
E. Mosekilde ◽  
P. Froguel ◽  
...  
Keyword(s):  
Beta Cell ◽  
Beta Cell Function ◽  
Cell Function ◽  
Pancreatic Beta Cell ◽  
Pancreatic Beta Cell Function ◽  
Glucokinase Mutations

Effect of troglitazone on insulin sensitivity and pancreatic beta-cell function in women at high risk for NIDDM

Diabetes ◽  
1996 ◽  
Vol 45 (11) ◽  
pp. 1572-1579 ◽  
Author(s):  
K. Berkowitz ◽  
R. Peters ◽  
S. L. Kjos ◽  
J. Goico ◽  
A. Marroquin ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
High Risk ◽  
Beta Cell ◽  
Beta Cell Function ◽  
Cell Function ◽  
Pancreatic Beta Cell ◽  
Pancreatic Beta Cell Function

scholarly journals An autophagy enhancer ameliorates diabetes of human IAPP-transgenic mice through clearance of amyloidogenic oligomer

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jinyoung Kim ◽  
Kihyoun Park ◽  
Min Jung Kim ◽  
Hyejin Lim ◽  
Kook Hwan Kim ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Function ◽  
Therapeutic Potential ◽  
Therapeutic Modality ◽  
Protective Effects ◽  
Β Cells ◽  
Β Cell ◽  
Islet Amyloid ◽  
Amyloid Accumulation ◽  
Human Diabetes

AbstractWe have reported that autophagy is crucial for clearance of amyloidogenic human IAPP (hIAPP) oligomer, suggesting that an autophagy enhancer could be a therapeutic modality against human diabetes with amyloid accumulation. Here, we show that a recently identified autophagy enhancer (MSL-7) reduces hIAPP oligomer accumulation in human induced pluripotent stem cell-derived β-cells (hiPSC-β-cells) and diminishes oligomer-mediated apoptosis of β-cells. Protective effects of MSL-7 against hIAPP oligomer accumulation and hIAPP oligomer-mediated β-cell death are significantly reduced in cells with knockout of MiTF/TFE family members such as Tfeb or Tfe3. MSL-7 improves glucose tolerance and β-cell function of hIAPP+ mice on high-fat diet, accompanied by reduced hIAPP oligomer/amyloid accumulation and β-cell apoptosis. Protective effects of MSL-7 against hIAPP oligomer-mediated β-cell death and the development of diabetes are also significantly reduced by β-cell-specific knockout of Tfeb. These results suggest that an autophagy enhancer could have therapeutic potential against human diabetes characterized by islet amyloid accumulation.

scholarly journals Pericytes contribute to the islet basement membranes to promote beta-cell gene expression

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lina Sakhneny ◽  
Alona Epshtein ◽  
Limor Landsman
Keyword(s):  
Gene Expression ◽  
Cell Function ◽  
Basement Membranes ◽  
Cell Physiology ◽  
Β Cells ◽  
Β Cell ◽  
Cell Clustering ◽  
Β Cell Function ◽  
Cell Gene Expression ◽  
Glucose Stimulated Insulin Secretion

Abstractβ-Cells depend on the islet basement membrane (BM). While some islet BM components are produced by endothelial cells (ECs), the source of others remains unknown. Pancreatic pericytes directly support β-cells through mostly unidentified secreted factors. Thus, we hypothesized that pericytes regulate β-cells through the production of BM components. Here, we show that pericytes produce multiple components of the mouse pancreatic and islet interstitial and BM matrices. Several of the pericyte-produced ECM components were previously implicated in β-cell physiology, including collagen IV, laminins, proteoglycans, fibronectin, nidogen, and hyaluronan. Compared to ECs, pancreatic pericytes produce significantly higher levels of α2 and α4 laminin chains, which constitute the peri-islet and vascular BM. We further found that the pericytic laminin isoforms differentially regulate mouse β-cells. Whereas α2 laminins promoted islet cell clustering, they did not affect gene expression. In contrast, culturing on Laminin-421 induced the expression of β-cell genes, including Ins1, MafA, and Glut2, and significantly improved glucose-stimulated insulin secretion. Thus, alongside ECs, pericytes are a significant source of the islet BM, which is essential for proper β-cell function.

scholarly journals Favorable Effects of GLP-1 Receptor Agonist against Pancreatic β-Cell Glucose Toxicity and the Development of Arteriosclerosis: “The Earlier, the Better” in Therapy with Incretin-Based Medicine

2021 ◽  
Vol 22 (15) ◽  
pp. 7917
Author(s):  
Hideaki Kaneto ◽  
Tomohiko Kimura ◽  
Masashi Shimoda ◽  
Atsushi Obata ◽  
Junpei Sanada ◽  
...  
Keyword(s):  
Large Scale ◽  
Cell Function ◽  
Apoptotic Cell ◽  
Early Stage ◽  
Insulin Biosynthesis ◽  
Protective Effects ◽  
Pancreatic Β Cell ◽  
Β Cells ◽  
Β Cell ◽  
Glucose Toxicity

Fundamental pancreatic β-cell function is to produce and secrete insulin in response to blood glucose levels. However, when β-cells are chronically exposed to hyperglycemia in type 2 diabetes mellitus (T2DM), insulin biosynthesis and secretion are decreased together with reduced expression of insulin transcription factors. Glucagon-like peptide-1 (GLP-1) plays a crucial role in pancreatic β-cells; GLP-1 binds to the GLP-1 receptor (GLP-1R) in the β-cell membrane and thereby enhances insulin secretion, suppresses apoptotic cell death and increase proliferation of β-cells. However, GLP-1R expression in β-cells is reduced under diabetic conditions and thus the GLP-1R activator (GLP-1RA) shows more favorable effects on β-cells at an early stage of T2DM compared to an advanced stage. On the other hand, it has been drawing much attention to the idea that GLP-1 signaling is important in arterial cells; GLP-1 increases nitric oxide, which leads to facilitation of vascular relaxation and suppression of arteriosclerosis. However, GLP-1R expression in arterial cells is also reduced under diabetic conditions and thus GLP-1RA shows more protective effects on arteriosclerosis at an early stage of T2DM. Furthermore, it has been reported recently that administration of GLP-1RA leads to the reduction of cardiovascular events in various large-scale clinical trials. Therefore, we think that it would be better to start GLP-1RA at an early stage of T2DM for the prevention of arteriosclerosis and protection of β-cells against glucose toxicity in routine medical care.

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