scholarly journals Lipophilicity predicts the ability of nonsulphonylurea drugs to block pancreatic beta-cell KATP channels and stimulate insulin secretion; statins as a test case

2018 ◽  
Vol 1 (2) ◽  
pp. e00017 ◽  
Author(s):  
Joana Real ◽  
Caroline Miranda ◽  
Charlotta S. Olofsson ◽  
Paul A. Smith

1999 ◽  
Vol 22 (2) ◽  
pp. 113-123 ◽  
Author(s):  
T Miki ◽  
K Nagashima ◽  
S Seino

ATP-sensitive K+ channels (KATP channels) play important roles in many cellular functions by coupling cell metabolism to electrical activity. The KATP channels in pancreatic beta-cells are thought to be critical in the regulation of glucose-induced and sulfonylurea-induced insulin secretion. Until recently, however, the molecular structure of the KATP channel was not known. Cloning members of the novel inwardly rectifying K+ channel subfamily Kir6.0 (Kir6.1 and Kir6.2) and the sulfonylurea receptors (SUR1 and SUR2) has clarified the molecular structure of KATP channels. The pancreatic beta-cell KATP channel comprises two subunits: a Kir6.2 subunit and an SUR1 subunit. Molecular biological and molecular genetic studies have provided insights into the physiological and pathophysiological roles of the pancreatic beta-cell KATP channel in insulin secretion.



FEBS Letters ◽  
2005 ◽  
Vol 579 (5) ◽  
pp. 1085-1088 ◽  
Author(s):  
Koichi Sugita ◽  
Saori Endo-Kasahara ◽  
Yoshifumi Tada ◽  
Yang Lijun ◽  
Hiroshi Yasuda ◽  
...  


Metabolites ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 355
Author(s):  
Ingo Rustenbeck ◽  
Torben Schulze ◽  
Mai Morsi ◽  
Mohammed Alshafei ◽  
Uwe Panten

The pancreatic beta-cell transduces the availability of nutrients into the secretion of insulin. While this process is extensively modified by hormones and neurotransmitters, it is the availability of nutrients, above all glucose, which sets the process of insulin synthesis and secretion in motion. The central role of the mitochondria in this process was identified decades ago, but how changes in mitochondrial activity are coupled to the exocytosis of insulin granules is still incompletely understood. The identification of ATP-sensitive K+-channels provided the link between the level of adenine nucleotides and the electrical activity of the beta cell, but the depolarization-induced Ca2+-influx into the beta cells, although necessary for stimulated secretion, is not sufficient to generate the secretion pattern as produced by glucose and other nutrient secretagogues. The metabolic amplification of insulin secretion is thus the sequence of events that enables the secretory response to a nutrient secretagogue to exceed the secretory response to a purely depolarizing stimulus and is thus of prime importance. Since the cataplerotic export of mitochondrial metabolites is involved in this signaling, an orienting overview on the topic of nutrient secretagogues beyond glucose is included. Their judicious use may help to define better the nature of the signals and their mechanism of action.



Science ◽  
1972 ◽  
Vol 175 (4026) ◽  
pp. 1128-1130 ◽  
Author(s):  
L. Orci ◽  
K. H. Gabbay ◽  
W. J. Malaisse


Diabetes ◽  
2021 ◽  
Vol 70 (Supplement 1) ◽  
pp. 38-OR
Author(s):  
ELENI GEORGIADOU ◽  
CHARANYA MURALIDHARAN ◽  
PAULINE L. CHABOSSEAU ◽  
ALEJANDRA TOMAS ◽  
THEODOROS STYLIANIDES ◽  
...  


1993 ◽  
Vol 264 (3) ◽  
pp. E441-E449 ◽  
Author(s):  
E. Christiansen ◽  
H. B. Andersen ◽  
K. Rasmussen ◽  
N. J. Christensen ◽  
K. Olgaard ◽  
...  

beta-Cell function and glucose metabolism were studied in eight insulin-dependent diabetic recipients of combined segmental pancreas and kidney transplant with peripheral insulin delivery (Px), in eight nondiabetic kidney-transplant individuals (Kx), and in eight normal subjects (Ns) after three consecutive mixed meals. All subjects had normal fasting plasma glucose, but increased basal levels of C-peptide were demonstrated in the transplant groups (P < 0.05 relative to Ns). Postprandial hyperglycemia was increased 14% in Kx and 32% in Px (P < 0.05), whereas compared with Ns postprandial C-peptide levels were increased three- and twofold, respectively, in Kx and Px (P < 0.05). Compared with Ns basal insulin secretion rate (combined model) was increased 2-fold in Kx and 1.4-fold in Px (P < 0.05). Maximal insulin secretion rate was reduced 25% in Px compared with Kx (P < 0.05) but not different from that of Ns (P NS). Also, maximal insulin secretion rate occurred later in Px than in controls (Tmax: Px 50 min, Kx 30 min, and Ns 32 min; P < 0.05). The total integrated insulin secretion was increased 1.4-fold in Px compared with Ns (P < 0.05) but decreased 1.4-fold compared with Kx (P < 0.05). Fasting and postprandial proinsulin-to-C-peptide molar ratios were inappropriately increased in Px compared with Kx and Ns. Basal hepatic glucose production was increased 43% in Px and 33% in Kx compared with Ns (P < 0.05). Postprandial total systemic glucose appearance was similar in all three groups, whereas peripheral glucose disposal was 15% reduced in Px (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)



2018 ◽  
Vol 52 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Eiji Yamato

Abstract Objective. Histone deacytylase inhibitors (HDACis) inhibit the deacetylation of the lysine residue of proteins, including histones, and regulate the transcription of a variety of genes. Recently, HDACis have been used clinically as anti-cancer drugs and possible anti-diabetic drugs. Even though HDACis have been proven to protect the cytokine-induced damage of pancreatic beta cells, evidence also shows that high doses of HDACis are cytotoxic. In the present study, we, therefore, investigated the eff ect of HDACis on insulin secretion in a pancreatic beta cell line. Methods. Pancreatic beta cells MIN6 were treated with selected HDACis (trichostatin A, TSA; valproic acid, VPA; and sodium butyrate, NaB) in medium supplemented with 25 mM glucose and 13% heat-inactivated fetal bovine serum (FBS) for indicated time intervals. Protein expression of Pdx1 and Mafa in MIN6 cells was demonstrated by immunohistochemistry and immunocytochemistry, expression of Pdx1 and Mafa genes was measured by quantitative RT-PCR method. Insulin release from MIN6 cells and insulin cell content were estimated by ELISA kit. Superoxide production in MIN6 cells was measured using a Total ROS/Superoxide Detection System. Results. TSA, VPA, and NaB inhibited the expression of Pdx1 and Mafa genes and their products. TSA treatment led to beta cell malfunction, characterized by enhanced insulin secretion at 3 and 9 mM glucose, but impaired insulin secretion at 15 and 25 mM glucose. Th us, TSA induced dysregulation of the insulin secretion mechanism. TSA also enhanced reactive oxygen species production in pancreatic beta cells. Conclusions. Our results showed that HDACis caused failure to suppress insulin secretion at low glucose concentrations and enhance insulin secretion at high glucose concentrations. In other words, when these HDACis are used clinically, high doses of HDACis may cause hypoglycemia in the fasting state and hyperglycemia in the fed state. When using HDACis, physicians should, therefore, be aware of the capacity of these drugs to modulate the insulin secretory capacity of pancreatic beta cells.



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