scholarly journals Effects of Hydroxysafflor Yellow A on the PI3K/AKT Pathway and Apoptosis of Pancreatic β-Cells in Type 2 Diabetes Mellitus Rats

2020 ◽  
Vol Volume 13 ◽  
pp. 1097-1107 ◽  
Author(s):  
Maosheng Lee ◽  
Huilin Li ◽  
Hengxia Zhao ◽  
Miao Suo ◽  
Deliang Liu
2021 ◽  
Vol 22 (3) ◽  
pp. 1059
Author(s):  
Bodo C. Melnik

Epidemiological studies associate milk consumption with an increased risk of Parkinson’s disease (PD) and type 2 diabetes mellitus (T2D). PD is an α-synucleinopathy associated with mitochondrial dysfunction, oxidative stress, deficient lysosomal clearance of α-synuclein (α-syn) and aggregation of misfolded α-syn. In T2D, α-syn promotes co-aggregation with islet amyloid polypeptide in pancreatic β-cells. Prion-like vagal nerve-mediated propagation of exosomal α-syn from the gut to the brain and pancreatic islets apparently link both pathologies. Exosomes are critical transmitters of α-syn from cell to cell especially under conditions of compromised autophagy. This review provides translational evidence that milk exosomes (MEX) disturb α-syn homeostasis. MEX are taken up by intestinal epithelial cells and accumulate in the brain after oral administration to mice. The potential uptake of MEX miRNA-148a and miRNA-21 by enteroendocrine cells in the gut, dopaminergic neurons in substantia nigra and pancreatic β-cells may enhance miRNA-148a/DNMT1-dependent overexpression of α-syn and impair miRNA-148a/PPARGC1A- and miRNA-21/LAMP2A-dependent autophagy driving both diseases. MiRNA-148a- and galactose-induced mitochondrial oxidative stress activate c-Abl-mediated aggregation of α-syn which is exported by exosome release. Via the vagal nerve and/or systemic exosomes, toxic α-syn may spread to dopaminergic neurons and pancreatic β-cells linking the pathogenesis of PD and T2D.


Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 128
Author(s):  
Yaser Albadr ◽  
Andrew Crowe ◽  
Rima Caccetta

The prevalence of type 2 diabetes mellitus is rising globally and this disease is proposed to be the next pandemic after COVID-19. Although the cause of type 2 diabetes mellitus is unknown, it is believed to involve a complex array of genetic defects that affect metabolic pathways which eventually lead to hyperglycaemia. This hyperglycaemia arises from an inability of the insulin-sensitive cells to sufficiently respond to the secreted insulin, which eventually results in the inadequate secretion of insulin from pancreatic β-cells. Several treatments, utilising a variety of mechanisms, are available for type 2 diabetes mellitus. However, more medications are needed to assist with the optimal management of the different stages of the disease in patients of varying ages with the diverse combinations of other medications co-administered. Throughout modern history, some lead constituents from ancient medicinal plants have been investigated extensively and helped in developing synthetic antidiabetic drugs, such as metformin. Teucrium polium L. (Tp) is a herb that has a folk reputation for its antidiabetic potential. Previous studies indicate that Tp extracts significantly decrease blood glucose levels r and induce insulin secretion from pancreatic β-cells in vitro. Nonetheless, the constituent/s responsible for this action have not yet been elucidated. The effects appear to be, at least in part, attributable to the presence of selected flavonoids (apigenin, quercetin, and rutin). This review aims to examine the reported glucose-lowering effect of the herb, with a keen focus on insulin secretion, specifically related to type 2 diabetes mellitus. An analysis of the contribution of the key constituent flavonoids of Tp extracts will also be discussed.


2018 ◽  
Vol 10 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Hirotaka Watada ◽  
Masanari Shiramoto ◽  
Shin Irie ◽  
Yasuo Terauchi ◽  
Yuichiro Yamada ◽  
...  

Endocrinology ◽  
2011 ◽  
Vol 152 (5) ◽  
pp. 1800-1808 ◽  
Author(s):  
Peter Kuehnen ◽  
Katharina Laubner ◽  
Klemens Raile ◽  
Christof Schöfl ◽  
Franz Jakob ◽  
...  

Leptin inhibits insulin secretion from pancreatic β-cells, and in turn, insulin stimulates leptin biosynthesis and secretion from adipose tissue. Dysfunction of this adipoinsular feedback loop has been proposed to be involved in the development of hyperinsulinemia and type 2 diabetes mellitus. At the molecular level, leptin acts through various pathways, which in combination confer inhibitory effects on insulin biosynthesis and secretion. The aim of this study was to identify molecular mechanisms of leptin action on insulin secretion in pancreatic β-cells. To identify novel leptin-regulated genes, we performed subtraction PCR in INS-1 β-cells. Regulated expression of identified genes was confirmed by RT-PCR and Northern and Western blotting. Furthermore, functional impact on β-cell function was characterized by insulin-secretion assays, intracellular Ca2+ concentration measurements, and enzyme activity assays. PP-1α, the catalytic subunit of protein phosphatase 1 (PP-1), was identified as a novel gene down-regulated by leptin in INS-1 pancreatic β-cells. Expression of PP-1α was verified in human pancreatic sections. PP-1α mRNA and protein expression is down-regulated by leptin, which culminates in reduction of PP-1 enzyme activity in β-cells. In addition, glucose-induced insulin secretion was inhibited by nuclear inhibitor of PP-1 and calyculin A, which was in part mediated by a reduction of PP-1-dependent calcium influx into INS-1 β-cells. These results identify a novel molecular pathway by which leptin confers inhibitory action on insulin secretion, and impaired PP-1 inhibition by leptin may be involved in dysfunction of the adipoinsular axis during the development of hyperinsulinemia and type 2 diabetes mellitus.


2019 ◽  
Vol 33 (12) ◽  
pp. 14760-14771
Author(s):  
Zheng-Da Pang ◽  
Yan Wang ◽  
Xiao-Jing Wang ◽  
Gang She ◽  
Xiao-Zhen Ma ◽  
...  

2014 ◽  
Vol 61 (4) ◽  
Author(s):  
Khalid Khalaf Alharbi ◽  
Imran Ali Khan ◽  
Yazeed A Al-Sheikh ◽  
Fawiziah Khalaf Alharbi ◽  
Fahad Khalaf Alharbi ◽  
...  

The ubiquitin-conjugating enzyme E2E 2 (UBE2E2) gene plays an important role in insulin synthe-sis and secretion under conditions in which stress to the endoplasmic reticu-lum is increased in β-cells. In this case-control study, we have selected rs7612462 polymorphism within UBE2E2 gene to identify in a Saudi population the type 2 diabetes mellitus (T2DM) subjects. In total, 376 subjects with T2DM and 380 controls were enrolled in this study. We have collected 5 mL of peripheral blood from each participant for biochemical and molecular analyses. PCR-RFLP was used to generate genotypes at rs7612462 in all of the study subjects. Clinical data and anthropometric measurements of the patients were significantly different from those of the controls (p


2020 ◽  
Vol 57 (11) ◽  
pp. 1383-1393
Author(s):  
Qingqing Zhao ◽  
Jinxin Zhou ◽  
Yu Pan ◽  
Huijun Ju ◽  
Liying Zhu ◽  
...  

Abstract Aims Steroid diabetes mellitus (SDM) is a metabolic syndrome caused by an increase in glucocorticoids, and its pathogenesis is unclear. 18F-FDG PET/CT can reflect the glucose metabolism of tissues and organs under living conditions. Here, PET/CT imaging of SDM and type 2 diabetes mellitus (T2DM) rats was used to visualize changes in glucose metabolism in the main glucose metabolizing organs and investigate the pathogenesis of SDM. Methods SDM and T2DM rat models were established. During this time, PET/CT imaging was used to measure the %ID/g value of skeletal muscle and liver to evaluate glucose uptake. The pancreatic, skeletal muscle and liver were analyzed by immunohistochemistry. Results SDM rats showed increased fasting blood glucose and insulin levels, hyperplasia of islet α and β cells, increased FDG uptake in skeletal muscle accompanied by an up-regulation of PI3Kp85α, IRS-1, and GLUT4, no significant changes in liver uptake, and that glycogen storage in the liver and skeletal muscle increased. T2DM rats showed atrophy of pancreatic islet β cells and decreased insulin levels, significantly reduced FDG uptake and glycogen storage in skeletal muscle and liver. Conclusions The pathogenesis of SDM is different from that of T2DM. The increased glucose metabolism of skeletal muscle may be related to the increased compensatory secretion of insulin. Glucocorticoids promote the proliferation of islet α cells and cause an increase in gluconeogenesis in the liver, which may cause increased blood glucose.


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