Structural finding of R/S-3,4-dihydro-2,2-dimethyl-6-halo-4-(substituted phenylaminocarbonylamino)-2H-1-benzopyrans as selective pancreatic β-cells KATP-pβ channel openers

2007 ◽  
Vol 85 (12) ◽  
pp. 1053-1063 ◽  
Author(s):  
Sk. Mahasin Alam ◽  
Soma Samanta ◽  
Amit Kumar Halder ◽  
Soumya Basu ◽  
Tarun Jha

R/S-3,4-Dihydro-2,2-dimethyl-6-halo-4-(substituted phenylaminocarbonyl-amino)-2H-1-benzopyrans are pancreatic β-cells potassium (KATP-pβ) channel openers with inhibitory effect on insulin secretion. To find the more active and effective benzopyrans as selective potassium (KATP-pβ) channel openers towards the pancreatic tissues, quantitative structure–activity relationships (QSAR) study was performed using E-state and R-state indices along with Wang–Ford charges, n-octanol/water partition coefficient, molar refractivity, and indicator parameters. QSAR models were developed by statistical techniques, e.g., multiple linear regression (MLR), principle component regression analysis (PCRA), and partial least squares (PLS) analysis. The generated equations were validated by the leave-one-out cross-validation method. The models show the importance of ETSA indices of atom numbers 16, 17, 18, 19, 21 as well as 22. The positive coefficient of S16, S17, S18, S19, S21, and S22 indicate that with the increase of the value of E-state indices, desired activity decreases. RTSA index is also important for the biological activity, and the atom numbers 16, 17, 18, 19, 20 and 22 are involved in van der Waals interactions. RTSA index also possesses negative impact on the inhibition of residual insulin secretion. Wang–Ford charges of some particular atoms are also important for the inhibition. Increase of n-octanol/water partition coefficients of compounds inhibit insulin secretion, and the presence of chlorine atom at m- and p- positions of the phenyl ring B is necessary for the inhibition of residual insulin secretion.Key words: benzopyran derivatives, potassium channel openers, PCRA, PLS, QSAR.

Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 741-748 ◽  
Author(s):  
Paul A. Smith

Somatostatin (SRIF) is a well-established inhibitor of insulin secretion, an effect in part mediated by a direct inhibition of voltage-operated Ca2+-channels. However, the identity of the somatostatin receptor subtypes (SSTRs) and voltage-operated Ca2+-channels involved in this process are unknown. Whole-cell perforated patch-clamp methods were applied to the murine pancreatic β-cell line, MIN6, to explore the molecular pharmacology of this problem. SRIF-14 inhibited voltage-gated Ca2+ currents (ICa2+) by 19 ± 3% (n=24) with a pEC50 = 9.05 (95% confidence limits 9–9.1). This action was mimicked solely by 100 nm CH-275, a selective agonist at the somatostatin type 1 receptor (SSTR1), but not by 100 nm BIM-23027, L-362855, or NNC-269100; agonists selective for the other four SSTRs known to exist in MIN6. The inhibition of ICa2+ produced by SRIF and CH-275 was insensitive to pertussis toxin but was reversed by a prepulse to +100 mV. The inhibition of ICa2+ by SRIF-14 was unaffected by 20 μm nifedipine, an inhibitor of L-type Ca2+ channels. Application of the specific N-type Ca2+ channel (Cav2.2) inhibitor ω-conotoxin GV1A at 100 nm mimicked, and as a consequence abolished, the inhibitory effect of SRIF-14 on ICa2+. SRIF selectively inhibits N-type Ca2+-channels in murine pancreatic β-cells via exclusive coupling with SSTR1. These findings help explain how SSTR1 activation can inhibit insulin secretion in pancreatic β-cells and suggest a possible new therapeutic lead for treatment of hyperinsulinemia. In pancreatic β-cells, somatostatin selectively inhibits N-type, but not other, Ca2+-channels via a direct and exclusive coupling with somatostatin receptor subtype 1.


2020 ◽  
Vol 295 (45) ◽  
pp. 15245-15252
Author(s):  
Fariborz Parandeh ◽  
Stefan Amisten ◽  
Gaurav Verma ◽  
Israa Mohammed Al-Amily ◽  
Pontus Dunér ◽  
...  

Type-2 diabetes (T2D) is a global disease caused by the inability of pancreatic β-cells to secrete adequate insulin. However, the molecular mechanisms underlying the failure of β-cells to respond to glucose in T2D remains unknown. Here, we investigated the relative contribution of UDP-glucose (UDP-G), a P2Y14-specific agonist, in the regulation of insulin release using human isolated pancreatic islets and INS-1 cells. P2Y14 was expressed in both human and rodent pancreatic β-cells. Dose-dependent activation of P2Y14 by UDP-G suppressed glucose-stimulated insulin secretion (GSIS) and knockdown of P2Y14 abolished the UDP-G effect. 12-h pretreatment of human islets with pertussis-toxin (PTX) improved GSIS and prevented the inhibitory effect of UDP-G on GSIS. UDP-G on GSIS suppression was associated with suppression of cAMP in INS-1 cells. UDP-G decreased the reductive capacity of nondiabetic human islets cultured at 5 mm glucose for 72 h and exacerbated the negative effect of 20 mm glucose on the cell viability during culture period. T2D donor islets displayed a lower reductive capacity when cultured at 5 mm glucose for 72 h that was further decreased in the presence of 20 mm glucose and UDP-G. Presence of a nonmetabolizable cAMP analog during culture period counteracted the effect of glucose and UDP-G. Islet cultures at 20 mm glucose increased apoptosis, which was further amplified when UDP-G was present. UDP-G modulated glucose-induced proliferation of INS-1 cells. The data provide intriguing evidence for P2Y14 and UDP-G's role in the regulation of pancreatic β-cell function.


2020 ◽  
Vol 33 (5) ◽  
pp. 671-674
Author(s):  
Tashunka Taylor-Miller ◽  
Jayne Houghton ◽  
Paul Munyard ◽  
Yadlapalli Kumar ◽  
Clinda Puvirajasinghe ◽  
...  

AbstractBackgroundCongenital hyperinsulinism (CHI), a condition characterized by dysregulation of insulin secretion from the pancreatic β cells, remains one of the most common causes of hyperinsulinemic, hypoketotic hypoglycemia in the newborn period. Mutations in ABCC8 and KCNJ11 constitute the majority of genetic forms of CHI.Case presentationA term macrosomic male baby, birth weight 4.81 kg, born to non-consanguineous parents, presented on day 1 of life with severe and persistent hypoglycemia. The biochemical investigations confirmed a diagnosis of CHI. Diazoxide was started and progressively increased to 15 mg/kg/day to maintain normoglycemia. Sequence analysis identified compound heterozygous mutations in ABCC8 c.4076C>T and c.4119+1G>A inherited from the unaffected father and mother, respectively. The mutations are reported pathogenic. The patient is currently 7 months old with a sustained response to diazoxide.ConclusionsBiallelic ABCC8 mutations are known to result in severe, diffuse, diazoxide-unresponsive hypoglycemia. We report a rare patient with CHI due to compound heterozygous mutations in ABCC8 responsive to diazoxide.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nana Kobayashi ◽  
Shogo Okazaki ◽  
Oltea Sampetrean ◽  
Junichiro Irie ◽  
Hiroshi Itoh ◽  
...  

2020 ◽  
Vol 11 ◽  
Author(s):  
Mengmeng Liu ◽  
Lele Ren ◽  
Xiangqin Zhong ◽  
Yaqin Ding ◽  
Tao Liu ◽  
...  

2016 ◽  
Vol 14 (11) ◽  
pp. 823-834 ◽  
Author(s):  
Xiao-Meng WAN ◽  
Mu ZHANG ◽  
Pei ZHANG ◽  
Zhi-Shen XIE ◽  
Feng-Guo XU ◽  
...  

2012 ◽  
Vol 287 (36) ◽  
pp. 30368-30375 ◽  
Author(s):  
Xin-Ya Chen ◽  
Xiu-Ting Gu ◽  
Hexige Saiyin ◽  
Bo Wan ◽  
Yu-Jing Zhang ◽  
...  

2011 ◽  
Vol 120 (9) ◽  
pp. 403-413 ◽  
Author(s):  
Mark A. Russell ◽  
Noel G. Morgan

Common polymorphisms within the FTO (fat mass and obesity-associated) gene correlate with increased BMI (body mass index) and a rising risk of Type 2 diabetes. FTO is highly expressed in the brain but has also been detected in peripheral tissues, including the endocrine pancreas, although its function there is unclear. The aim of the present study was to investigate the role of FTO protein in pancreatic β-cells using a conditional expression system developed in INS-1 cells. INS-1 cells were stably transfected with FTO–HA (haemagluttinin) incorporated under the control of a tetracycline-inducible promoter. Induction of FTO protein resulted in localization of the tagged protein to the nucleus. The level of FTO–HA protein achieved in transfected cells was tightly regulated, and experiments with selective inhibitors revealed that FTO–HA is rapidly degraded via the ubiquitin/proteasome pathway. The nuclear localization was not altered by proteasome inhibitors, although following treatment with PYR-41, an inhibitor of ubiquitination, some of the protein adopted a perinuclear localization. Unexpectedly, modestly increased expression of FTO–HA selectively enhanced the first phase of insulin secretion when INS-1 monolayers or pseudoislets were stimulated with 20 mM glucose, whereas the second phase remained unchanged. The mechanism responsible for the potentiation of glucose-induced insulin secretion is unclear; however, further experiments revealed that it did not involve an increase in insulin biosynthesis or any changes in STAT3 (signal transducer and activator of transcription 3) expression. Taken together, these results suggest that the FTO protein may play a hitherto unrecognized role in the control of first-phase insulin secretion in pancreatic β-cells.


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