P-146 Ethanolic extract of Morus alba Linn. leaf increases glucose uptake and glucose transporter 4 translocation in adipose cells of streptozotocin-induced diabetic rats

2008 ◽  
Vol 79 ◽  
pp. S108 ◽  
Author(s):  
Jarinyaporn Naowaboot ◽  
Patchareewan Pannangpetch ◽  
Veerapol Kukongviriyapan ◽  
Upa Kukongviriyapan
2017 ◽  
Vol 41 (5) ◽  
pp. 1777-1787 ◽  
Author(s):  
Zhenwen Zhang ◽  
Penghua Fang ◽  
Lili Guo ◽  
Biao He ◽  
Mingyi Shi ◽  
...  

Background/Aims: Glucose uptake occurs via the activation of an insulin-signaling cascade, resulting in the translocation of glucose transporter 4 (GLUT4) to the plasma membrane of adipocytes and myocytes. Recent research found that galanin could boost insulin-induced glucose uptake. This study aimed to explore whether activation of Akt2 mediates the beneficial effects of galanin on insulin-induced glucose uptake in the adipocytes of diabetic rats. Method: In this experiment, insulin, galanin and MK-2206, an Akt inhibitor, were injected individually or in combination into diabetic rats once a day for ten days. Then, glucose uptake and pAkt2 and its downstream proteins were examined in adipocytes. Results: Administration of galanin significantly enhanced insulin-induced 2-Deoxy-D-[3H]glucose uptake; GLUT4 and vesicle-associated membrane protein 2 contents in plasma membranes; and pAkt2Thr308/Ser473 and Akt2 mRNA expression levels in adipocytes. In addition, Akt2 downstream proteins including phosphorylated AS160 were increased, but the levels of phosphorylated forkhead box O1 and glycogen synthase kinase-3β were reduced. Treatment with MK-2206 may block the beneficial effects of galanin on these insulin-induced events. Conclusions: The results of this study suggest that phosphorylation of Akt2 mediates the beneficial effects of galanin on insulin-induced glucose uptake in the adipocytes of diabetic rats.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Aaraf Dewan ◽  
Maysoon Salih ◽  
Christopher Triggle ◽  
Hong Ding ◽  
Balwant Tuana

As one of the leading causes of heart disease, diabetes is a problem which needs a solution. Regulation of glucose uptake and metabolism within skeletal and cardiac muscle has proven capable of altering systemic glucose levels and impacting metabolism to potentially improve patient outcomes. Unfortunately, to date, very few muscle specific metabolic regulators are known which can allow us to achieve blood glucose uptake and metabolism. Sarcolemmal Membrane Associated Protein Isoform 1 (SLMAP1) is a novel protein expressed predominantly within muscle tissue. It has been linked to diabetes through animal models, although its role in metabolism remains to be defined. Here we describe a novel role for SLMAP1 in glucose metabolism within the myocardium. We engineered a transgenic (TG) mouse with cardiac specific expression of SLMAP1. Using neonatal cardiomyocytes (NCMs) collected from these mice we performed glucose uptake assays with 2-deoxy-glucose (2DG), measured glycolytic rate using an Extracellular Flux XF24e Bioanalyzer, and analyzed glucose transporter 4 (GLUT4) trafficking using Western Blots, qPCR, and immunofluorescence imaging. NCMs extracted from TG hearts expressing SLMAP1 displayed increased levels of 2DG uptake (93% ± 25%, n=5, P<0.01), basal glycolysis (glycolysis (92 ± 40%, n=5, P<0.05), and maximal glycolysis (75 ± 31%, n=5, P<0.05) compared with wildtype littermates. Confocal microscopy revealed both increased localization of glucose transporter 4 (GLUT4) at the cell surface as well as an expansion of GLUT4 early endosomes in TG NCMs. The data here indicates SLMAP1 as a novel regulator of glucose uptake and metabolism in the myocardium. The targeted expression of SLMAP1 in a muscle specific manner may enhance systemic glycemic control and serve to limit cardiovascular disease in metabolic disorders such as diabetes.


2010 ◽  
Vol 74 (10) ◽  
pp. 2036-2042 ◽  
Author(s):  
Norio YAMAMOTO ◽  
Manabu UEDA ◽  
Kyuichi KAWABATA ◽  
Takuya SATO ◽  
Kengo KAWASAKI ◽  
...  

2017 ◽  
Vol 58 (4) ◽  
pp. 193-198 ◽  
Author(s):  
Anthony L Albiston ◽  
Mauricio Cacador ◽  
Puspha Sinnayah ◽  
Peta Burns ◽  
Siew Yeen Chai

Insulin-regulated aminopeptidase (IRAP) co-localizes with the glucose transporter 4 (GLUT4) in GLUT4 storage vesicles (GSV) in insulin-responsive cells. In response to insulin, IRAP is the only transmembrane enzyme known to translocate together with GLUT4 to the plasma membrane in adipocytes and muscle cells. Although the intracellular region of IRAP is associated with GLUT4 vesicle trafficking, the role of the aminopeptidase activity in insulin-responsive cells has not been elucidated. The aim of this study was to investigate whether the inhibition of the aminopeptidase activity of IRAP facilitates glucose uptake in insulin-responsive cells. In both in vitro and in vivo studies, inhibition of IRAP aminopeptidase activity with the specific inhibitor, HFI-419, did not modulate glucose uptake. IRAP inhibition in the L6GLUT4myc cell line did not alter glucose uptake in both basal and insulin-stimulated state. In keeping with these results, HFI419 did not affect peripheral, whole-body glucose handling after an oral glucose challenge, neither in normal rats nor in the streptozotocin (STZ)-induced experimental rat model of diabetes mellitus (DM). Therefore, acute inhibition of IRAP aminopeptidase activity does not affect glucose homeostasis.


Endocrinology ◽  
2016 ◽  
Vol 157 (11) ◽  
pp. 4094-4103 ◽  
Author(s):  
Zhu Li ◽  
Julie L. Frey ◽  
G. William Wong ◽  
Marie-Claude Faugere ◽  
Michael J. Wolfgang ◽  
...  

2019 ◽  
Vol 11 (3) ◽  
pp. 240
Author(s):  
SurapaneniKrishna Mohan ◽  
Murad Alsawalha ◽  
AbeerMohammed Al-Subaie ◽  
ReemYousuf Al-Jindan ◽  
SrinivasaRao Bolla ◽  
...  

1994 ◽  
Vol 267 (5) ◽  
pp. F816-F824 ◽  
Author(s):  
R. G. Marcus ◽  
R. England ◽  
K. Nguyen ◽  
M. J. Charron ◽  
J. P. Briggs ◽  
...  

Because the insulin-responsive glucose transporter, GLUT4, is expressed in renal vascular and glomerular cells, we determined the effects of experimental diabetes mellitus on GLUT4 expression and glucose uptake by these tissues. Quantitative reverse-transcription polymerase chain reaction studies of microdissected afferent microvessels and renal glomeruli showed that, after 1 wk of diabetes, GLUT4 mRNA was decreased to 26 and 34% of control values, respectively. GLUT4 immunoblots of renal glomerular and microvessel samples showed that GLUT4 polypeptide was decreased to 51% of control values. These results were confirmed by indirect immunofluorescence, which showed decreased GLUT4 expression in glomerular cells and in vascular smooth muscle cells of the afferent microvasculature of diabetic animals. Uptake of the glucose analogue, 2-deoxyglucose, was also depressed in microvessels of diabetic rats to 57% of control values, supporting the conclusion that fewer total glucose transporters were available for glucose uptake into diabetic renal glomerular and microvascular cells. Thus both GLUT4 expression and glucose uptake by glomerular and microvascular cells are decreased in diabetic animals. These results have led us to suggest a mechanism by which decreased renal GLUT4 expression could contribute to glomerular hyperfiltration and hypertension seen in early diabetes.


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