Regulation of Glucose Uptake in Mesangial Cells Stimulated by High Glucose: Role of Angiotensin II and Insulin

2009 ◽  
Vol 234 (9) ◽  
pp. 1095-1101 ◽  
Author(s):  
Carine P. Arnoni ◽  
Carla Lima ◽  
Priscila C. Cristovam ◽  
Edgar Maquigussa ◽  
Daniela B. Vidotti ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Glucose Uptake ◽  
High Glucose ◽  
Glucose Transporter ◽  
Mesangial Cells ◽  
Dependent Manner ◽  
Beneficial Effects ◽  
Fibronectin Expression ◽  
Insulin Dependent

Mesangial cells (MCs) play a central role in the pathogenesis of diabetic nephropathy (DN). MC dysfunction arises from excessive glucose uptake through insulin-independent glucose transporter (GLUT1). The role of the insulin-dependent transporter (GLUT4) remains unknown. This study evaluated the effect of high glucose on GLUT1, GLUT4, and fibronectin expression levels. Glucose uptake was determined in the absence and presence of insulin. Angiotensin II has been implicated as a mediator of MC abnormalities in DN, and its effects on the GLUTs expression were evaluated in the presence of losartan. MCs were exposed to normal (NG, 10 m M) or high (HG, 30 m M) glucose for 1, 4, 12, 24, and 72 hrs. Glucose uptake was elevated from 1 hr up to 24 hrs of HG, but returned to NG levels after 72 hrs. HG induced an early (1-, 4-, and 12-hrs) rise in GLUT1 expression, returning to NG levels after 72 hrs, whereas GLUT4 was overexpressed at later timepoints (24 and 72 hrs). HG during 4 hrs induced a 40% rise in glucose uptake, which was unaffected by insulin. In contrast, after 72 hrs, glucose uptake was increased by 50%, only under insulin stimulus. Losartan blunted the effects of HG on GLUT1, GLUT4, and fibronectin expression and on glucose uptake. Results suggest that MCs can be highly susceptible to the HG environment since they uptake glucose in both an insulin-independent and insulin-dependent manner. The beneficial effects of angiotensin II inhibition in DN may also involve a decrease in the rate of glucose uptake by MCs.

scholarly journals Functional role of sodium glucose transporter in high glucose-mediated angiotensin type 1 receptor downregulation in human proximal tubule cells

2012 ◽  
Vol 303 (5) ◽  
pp. F766-F774 ◽  
Author(s):  
Rekha Yesudas ◽  
Russell Snyder ◽  
Thomas Abbruscato ◽  
Thomas Thekkumkara
Keyword(s):  
Proximal Tubule ◽  
Glucose Uptake ◽  
High Glucose ◽  
Glucose Transporter ◽  
Glucose Transporters ◽  
Ang Ii ◽  
Angiotensin Type ◽  
Human Proximal Tubule

Previously, we have demonstrated human angiotensin type 1 receptor (hAT1R) promoter architecture with regard to the effect of high glucose (25 mM)-mediated transcriptional repression in human proximal tubule epithelial cells (hPTEC; Thomas BE, Thekkumkara TJ. Mol Biol Cell 15: 4347–4355, 2004). In the present study, we investigated the role of glucose transporters in high glucose-mediated hAT1R repression in primary hPTEC. Cells were exposed to normal glucose (5.5 mM) and high glucose (25 mM), followed by determination of hyperglycemia-mediated changes in receptor expression and glucose transporter activity. Exposure of cells to high glucose resulted in downregulation of ANG II binding (4,034 ± 163.3 to 1,360 ± 154.3 dpm/mg protein) and hAT1R mRNA expression (reduced 60.6 ± 4.643%) at 48 h. Under similar conditions, we observed a significant increase in glucose uptake (influx) in cells exposed to hyperglycemia. Our data indicated that the magnitude of glucose influx is concentration and time dependent. In euglycemic cells, inhibiting sodium-glucose cotransporters (SGLTs) with phlorizin and facilitative glucose transporters (GLUTs) with phloretin decreased glucose influx by 28.57 ± 0.9123 and 54.33 ± 1.202%, respectively. However, inhibiting SGLTs in cells under hyperglycemic conditions decreased glucose influx by 53.67 ± 2.906%, while GLUT-mediated glucose uptake remained unaltered (57.67 ± 3.180%). Furthermore, pretreating cells with an SGLT inhibitor reversed high glucose-mediated downregulation of the hAT1R, suggesting an involvement of SGLT in high glucose-mediated hAT1R repression. Our results suggest that in hPTEC, hyperglycemia-induced hAT1R downregulation is largely mediated through SGLT-dependent glucose influx. As ANG II is an important modulator of hPTEC transcellular sodium reabsorption and function, glucose-mediated changes in hAT1R gene expression may participate in the pathogenesis of diabetic renal disease.

scholarly journals High Glucose Induces Sumoylation of Smad4 via SUMO2/3 in Mesangial Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Xueqin Zhou ◽  
Chenlin Gao ◽  
Wei Huang ◽  
Maojun Yang ◽  
Guo Chen ◽  
...  
Keyword(s):  
High Glucose ◽  
Laser Scanning ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Critical Role ◽  
Confocal Laser ◽  
Dependent Manner ◽  
High Glucose Condition ◽  
Dose Dependent

Recent studies have shown that sumoylation is a posttranslational modification involved in regulation of the transforming growth factor-β(TGF-β) signaling pathway, which plays a critical role in renal fibrosis in diabetic nephropathy (DN). However, the role of sumoylation in the regulation of TGF-βsignaling in DN is still unclear. In the present study, we investigated the expression of SUMO (SUMO1 and SUMO2/3) and Smad4 and the interaction between SUMO and Smad4 in cultured rat mesangial cells induced by high glucose. We found that SUMO1 and SUMO2/3 expression was significantly increased in the high glucose groups compared to the normal groupP<0.05. Smad4 and fibronectin (FN) levels were also increased in the high glucose groups in a dose-dependent manner. Coimmunoprecipitation and confocal laser scanning revealed that Smad4 interacted and colocalized with SUMO2/3, but not with SUMO1 in mesangial cells. Sumoylation (SUMO2/3) of Smad4 under high glucose condition was strongly enhanced compared to normal controlP<0.05. These results suggest that high glucose may activate TGF-β/Smad signaling through sumoylation of Samd4 by SUMO2/3 in mesangial cells.

Effect of High Glucose on Superoxide in Human Mesangial Cells: Role of Angiotensin II

2005 ◽  
Vol 100 (1) ◽  
pp. 46-53 ◽  
Author(s):  
David J. Leehey ◽  
Majd A. Isreb ◽  
Sonja Marcic ◽  
Ashok K. Singh ◽  
Rekha Singh
Keyword(s):  
Angiotensin Ii ◽  
High Glucose ◽  
Mesangial Cells ◽  
Human Mesangial Cells

scholarly journals Drosophila Solute Carrier 5A5 Regulates Systemic Glucose Homeostasis by Mediating Glucose Absorption in the Midgut

2021 ◽  
Vol 22 (22) ◽  
pp. 12424
Author(s):  
Yue Li ◽  
Weidong Wang ◽  
Hui-Ying Lim
Keyword(s):  
Glucose Uptake ◽  
Glucose Homeostasis ◽  
Metabolic Disorders ◽  
Glucose Transporter ◽  
Apical Membrane ◽  
Molecular Genetic ◽  
Glucose Absorption ◽  
Dependent Manner ◽  
Solute Carrier

The small intestine is the initial site of glucose absorption and thus represents the first of a continuum of events that modulate normal systemic glucose homeostasis. A better understanding of the regulation of intestinal glucose transporters is therefore pertinent to our efforts in curbing metabolic disorders. Using molecular genetic approaches, we investigated the role of Drosophila Solute Carrier 5A5 (dSLC5A5) in regulating glucose homeostasis by mediating glucose uptake in the fly midgut. By genetically knocking down dSLC5A5 in flies, we found that systemic and circulating glucose and trehalose levels are significantly decreased, which correlates with an attenuation in glucose uptake in the enterocytes. Reciprocally, overexpression of dSLC5A5 significantly increases systemic and circulating glucose and trehalose levels and promotes glucose uptake in the enterocytes. We showed that dSLC5A5 undergoes apical endocytosis in a dynamin-dependent manner, which is essential for glucose uptake in the enterocytes. Furthermore, we showed that the dSLC5A5 level in the midgut is upregulated by glucose and that dSLC5A5 critically directs systemic glucose homeostasis on a high-sugar diet. Together, our studies have uncovered the first Drosophila glucose transporter in the midgut and revealed new mechanisms that regulate glucose transporter levels and activity in the enterocyte apical membrane.

scholarly journals High Glucose and Lipopolysaccharide Prime NLRP3 Inflammasome via ROS/TXNIP Pathway in Mesangial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hong Feng ◽  
Junling Gu ◽  
Fang Gou ◽  
Wei Huang ◽  
Chenlin Gao ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Nlrp3 Inflammasome ◽  
High Glucose ◽  
Mesangial Cells ◽  
Central Component ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Interacting Protein

While inflammation is considered a central component in the development in diabetic nephropathy, the mechanism remains unclear. The NLRP3 inflammasome acts as both a sensor and a regulator of the inflammatory response. The NLRP3 inflammasome responds to exogenous and endogenous danger signals, resulting in cleavage of procaspase-1 and activation of cytokines IL-1β, IL-18, and IL-33, ultimately triggering an inflammatory cascade reaction. This study observed the expression of NLRP3 inflammasome signaling stimulated by high glucose, lipopolysaccharide, and reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine in glomerular mesangial cells, aiming to elucidate the mechanism by which the NLRP3 inflammasome signaling pathway may contribute to diabetic nephropathy. We found that the expression of thioredoxin-interacting protein (TXNIP), NLRP3, and IL-1βwas observed by immunohistochemistry in vivo. Simultaneously, the mRNA and protein levels of TXNIP, NLRP3, procaspase-1, and IL-1βwere significantly induced by high glucose concentration and lipopolysaccharide in a dose-dependent and time-dependent manner in vitro. This induction by both high glucose and lipopolysaccharide was significantly inhibited by N-acetyl-L-cysteine. Our results firstly reveal that high glucose and lipopolysaccharide activate ROS/TXNIP/ NLRP3/IL-1βinflammasome signaling in glomerular mesangial cells, suggesting a mechanism by which inflammation may contribute to the development of diabetic nephropathy.

scholarly journals LncRNA NEAT1 Promotes High Glucose-Induced Mesangial Cell Hypertrophy by Targeting miR-222-3p/CDKN1B Axis

2021 ◽  
Vol 7 ◽  
Author(s):  
Lin Liao ◽  
Jie Chen ◽  
Chuanfu Zhang ◽  
Yue Guo ◽  
Weiwei Liu ◽  
...  
Keyword(s):  
High Glucose ◽  
Noncoding Rna ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Morphological Alteration ◽  
Glomerular Hypertrophy ◽  
Cell Hypertrophy ◽  
Rna Immunoprecipitation ◽  
Lncrna Neat1

Glomerular hypertrophy is an early morphological alteration in diabetic nephropathy. Cyclin-Dependent Kinases have been shown to be required for high glucose (HG)-induced hypertrophy; however, the upstream regulators of CDKN1B in glomerular hypertrophy remain unclear. Herein we describe a novel pathway in which Long noncoding RNA (lncRNA) NEAT1 regulates the progression of mesangial cell hypertrophy via a competing endogenous RNA (ceRNA) mechanism. Real-time PCR was performed to detect the relative NEAT1 and miR-222-3p expressions and further confirmed the relationship between NEAT1 and miR-222-3p. Cell cycle was evaluated by flow cytometry. The related mechanisms were explored by Western blot, RNA immunoprecipitation and chromatin immunoprecipitation assay. We show that NEAT1 forms double stranded RNA (dsRNA) with miR-222-3p, thus limiting miR-222-3p’s binding with CDKN1B. This release of CDKN1B mRNA leads to elevated CDKN1B protein expression, resulting in hypertrophy. In addition, we demonstrated that STAT3 which is activated by HG induces the transcription of NEAT1 by binding to its promoter. Our findings underscore an unexpected role of lncRNAs on gene regulation and introduce a new mode of proliferation regulation in mesangial cells.

scholarly journals Sauchinone Protects Renal Mesangial Cell Dysfunction against Angiotensin II by Improving Renal Fibrosis and Inflammation

2020 ◽  
Vol 21 (19) ◽  
pp. 7003
Author(s):  
Jung Joo Yoon ◽  
Hyeon Kyoung Lee ◽  
Hye Yoom Kim ◽  
Byung Hyuk Han ◽  
Ho Sub Lee ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Diabetic Nephropathy ◽  
Angiotensin Ii ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Tissue Growth ◽  
Biologically Active ◽  
Dependent Manner ◽  
Saururus Chinensis ◽  
Mesangial Cell Proliferation

Abnormal and excessive growth of mesangial cells is important in the pathophysiologic processes of diabetes-associated interstitial fibrosis and glomerulosclerosis, leading to diabetic nephropathy, which eventually turns into end-stage renal disease. Sauchinone, a biologically-active lignan isolated from aerial parts of Saururus chinensis, has anti-inflammatory and anti-viral activities effects on various cell types. However, there are no studies reporting the effects of sauchinone on diabetic nephropathy. The present study aims to investigate the role of sauchinone in mesangial cell proliferation and fibrosis induced by angiotensin II, as well as the underlying mechanisms of these processes. Human renal mesangial cells were induced by angiotensin II (AngII, 10 μM) in the presence or absence of sauchinone (0.1–1 μM) and incubated for 48 h. In this study, we found that AngII induced mesangial cell proliferation, while treatment with sauchinone inhibited the cell proliferation in a dose-dependent manner. Pre-treatment with sauchinone induced down-regulation of cyclins/CDKs and up-regulation of CDK inhibitor, p21, and p27kip1 expression. In addition, AngII-enhanced expression of fibrosis biomarkers such as fibronectin, collagen IV, and connective tissue growth factor (CTGF), which was markedly attenuated by sauchinone. Sauchinone also decreased AngII-induced TGF-β1 and Smad-2, Smad-3, and Smad-4 expression. This study further revealed that sauchinone ameliorated AngII-induced mesangial inflammation through disturbing activation of inflammatory factors, and NLRP3 inflammasome, which is composed of the NLRP3 protein, procaspase-1, and apoptosis-associated speck-like protein containing a CARD (ASC). Moreover, pretreatment of sauchinone inhibited NF-κB translocation and ROS production in AngII-exposed mesangial cells. These data suggest that sauchinone has a protective effect on renal proliferation, fibrosis and inflammation. Therefore, sauchinone might be a potential pharmacological agent in prevention of AngII-induced renal damage leading to diabetic nephropathy.

Molecular mechanism of ADP-ribosyl cyclase activation in angiotensin II signaling in murine mesangial cells

2008 ◽  
Vol 294 (4) ◽  
pp. F982-F989 ◽  
Author(s):  
Seon-Young Kim ◽  
Rukhsana Gul ◽  
So-Young Rah ◽  
Suhn Hee Kim ◽  
Sung Kwang Park ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Protein Tyrosine Kinase ◽  
Nuclear Translocation ◽  
Mesangial Cells ◽  
Dependent Manner ◽  
Ang Ii ◽  
Akt Phosphorylation ◽  
Cyclase Activation ◽  
Adp Ribosyl Cyclase ◽  
Phosphoinositide 3 Kinase

ADP-ribosyl cyclase (ADPR-cyclase) produces a Ca2+-mobilizing second messenger cyclic ADP-ribose (cADPR) from NAD+. In this study, we investigated the molecular basis of ADPR-cyclase activation and the following cellular events in angiotensin II (ANG II) signaling in mouse mesangial cells (MMCs). Treatment of MMCs with ANG II induced an increase in intracellular Ca2+ concentrations through a transient Ca2+ release via an inositol 1,4,5-trisphosphate receptor and a sustained Ca2+ influx via L-type Ca2+ channels. The sustained Ca2+ signal, but not the transient Ca2+ signal, was blocked by a cADPR antagonistic analog, 8-bromo-cADPR (8-Br-cADPR), and an ADPR-cyclase inhibitor, 4,4′-dihydroxyazobenzene (DHAB). In support of the results, ANG II stimulated cADPR production in a time-dependent manner, and DHAB inhibited ANG II-induced cADPR production. Application of pharmacological inhibitors revealed that activation of ADPR-cyclase by ANG II involved ANG II type 1 receptor, phosphoinositide 3-kinase, protein tyrosine kinase, and phospolipase C-γ1. Moreover, DHAB as well as 8-Br-cADPR abrogated ANG II-mediated Akt phosphorylation, nuclear translocation of nuclear factor of activated T cell, and uptake of [3H]thymidine and [3H]leucine in MMCs. These results demonstrate that ADPR-cyclase in MMCs plays a pivotal role in ANG II signaling for cell proliferation and protein synthesis.

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