scholarly journals Reciprocal regulation of miR-214 and PTEN by high glucose regulates renal glomerular mesangial and proximal tubular epithelial cell hypertrophy and matrix expansion

2017 ◽  
Vol 313 (4) ◽  
pp. C430-C447 ◽  
Author(s):  
Amit Bera ◽  
Falguni Das ◽  
Nandini Ghosh-Choudhury ◽  
Meenalakshmi M. Mariappan ◽  
Balakuntalam S. Kasinath ◽  
...  
Keyword(s):  
High Glucose ◽  
Matrix Protein ◽  
Glycogen Synthase ◽  
Protein Accumulation ◽  
Small Interfering Rnas ◽  
Aberrant Expression ◽  
Akt Activation ◽  
Cell Hypertrophy ◽  
Fibronectin Expression ◽  
Proximal Tubular

Aberrant expression of microRNAs (miRs) contributes to diabetic renal complications, including renal hypertrophy and matrix protein accumulation. Reduced expression of phosphatase and tensin homolog (PTEN) by hyperglycemia contributes to these processes. We considered involvement of miR in the downregulation of PTEN. In the renal cortex of type 1 diabetic mice, we detected increased expression of miR-214 in association with decreased levels of PTEN and enhanced Akt phosphorylation and fibronectin expression. Mesangial and proximal tubular epithelial cells exposed to high glucose showed augmented expression of miR-214. Mutagenesis studies using 3′-UTR of PTEN in a reporter construct revealed PTEN as a direct target of miR-214, which controls its expression in both of these cells. Overexpression of miR-214 decreased the levels of PTEN and increased Akt activity similar to high glucose and lead to phosphorylation of its substrates glycogen synthase kinase-3β, PRAS40, and tuberin. In contrast, quenching of miR-214 inhibited high-glucose-induced Akt activation and its substrate phosphorylation; these changes were reversed by small interfering RNAs against PTEN. Importantly, respective expression of miR-214 or anti-miR-214 increased or decreased the mammalian target of rapamycin complex 1 (mTORC1) activity induced by high glucose. Furthermore, mTORC1 activity was controlled by miR-214-targeted PTEN via Akt activation. In addition, neutralization of high-glucose-stimulated miR-214 expression significantly inhibited cell hypertrophy and expression of the matrix protein fibronectin. Finally, the anti-miR-214-induced inhibition of these processes was reversed by the expression of constitutively active Akt kinase and hyperactive mTORC1. These results uncover a significant role of miR-214 in the activation of mTORC1 that contributes to high-glucose-induced mesangial and proximal tubular cell hypertrophy and fibronectin expression.

scholarly journals Deacetylation of S6 kinase promotes high glucose–induced glomerular mesangial cell hypertrophy and matrix protein accumulation

2019 ◽  
Vol 294 (24) ◽  
pp. 9440-9460 ◽  
Author(s):  
Falguni Das ◽  
Soumya Maity ◽  
Nandini Ghosh-Choudhury ◽  
Balakuntalam S. Kasinath ◽  
Goutam Ghosh Choudhury
Keyword(s):  
High Glucose ◽  
Matrix Protein ◽  
Mesangial Cell ◽  
Protein Accumulation ◽  
Glomerular Mesangial Cell ◽  
S6 Kinase ◽  
Cell Hypertrophy

Hexosamines and TGF-β1 use similar signaling pathways to mediate matrix protein synthesis in mesangial cells

2004 ◽  
Vol 286 (2) ◽  
pp. F409-F416 ◽  
Author(s):  
Lalit P. Singh ◽  
Kenneith Green ◽  
Michelle Alexander ◽  
Shira Bassly ◽  
Errol D. Crook
Keyword(s):  
High Glucose ◽  
Matrix Protein ◽  
Transforming Growth Factor ◽  
Cell Function ◽  
Mesangial Cells ◽  
Rat Kidney ◽  
Protein Accumulation ◽  
Western Blots ◽  
Matrix Production ◽  
Mes Cells

Hyperglycemia-induced alterations in mesangial (MES) cell function and extracellular matrix (ECM) protein accumulation are seen in diabetic glomerulopathy. Transforming growth factor-β1 (TGF-β1) mediates high-glucose-induced matrix production in the kidney. Recent studies demonstrated that some of the effects of high glucose on cellular metabolism are mediated by the hexosamine biosynthesis pathway (HBP) in which fructose-6-phosphate is converted to glucosamine (GlcN) 6-phosphate. We previously showed that the high-glucose-mediated fibronectin and laminin synthesis in MES cells is mediated by the HBP and that GlcN is more potent than glucose in inducing TGF-β1 promoter luciferase activity. In this study, we investigated the hypothesis that the effects of glucose on MES matrix production occur via hexosamine regulation of TGF-β1. Culturing simian virus (SV)-40-transformed rat kidney MES cells in 25 mM glucose (HG) for 48 h increases cellular fibronectin and laminin levels about twofold on Western blots compared with low glucose (5 mM). GlcN (1.5 mM) or TGF-β1 (2.5-5 ng/ml) for 24-48 h also increases ECM synthesis. However, the effects of HG or GlcN with TGF-β1 are not additive. The presence of anti-TGF-β1 antibodies (20 μg/ml) blocks both TGF-β1- and GlcN-induced fibronectin synthesis. TGF-β1 increased ECM levels via PKA (laminin and fibronectin) and PKC (fibronectin) pathways. Similarly, TGF-β1 and hexosamines led to nonadditive increases in phosphorylation of the cAMP responsive element binding transcription factor. These results suggest that the effects of excess glucose on MES ECM synthesis occur via HBP-mediated regulation of TGF-β1.

scholarly journals Therapy with antisense TGF-β1 oligodeoxynucleotides reduces kidney weight and matrix mRNAs in diabetic mice

2000 ◽  
Vol 278 (4) ◽  
pp. F628-F634 ◽  
Author(s):  
Dong Cheol Han ◽  
Brenda B. Hoffman ◽  
Soon Won Hong ◽  
Jia Guo ◽  
Fuad N. Ziyadeh
Keyword(s):  
Proximal Tubule ◽  
High Glucose ◽  
Leucine Incorporation ◽  
Diabetic Mice ◽  
Renal Hypertrophy ◽  
Kidney Weight ◽  
Cell Hypertrophy ◽  
Proximal Tubular ◽  
Tgf Β1

Inhibition of gene expression by antisense oligodeoxynucleotides (ODNs) relies on their ability to bind complementary mRNA sequences and prevent translation. The proximal tubule is a suitable target for ODN therapy in vivo because circulating ODNs accumulate in the proximal tubule in high concentrations. Because increased proximal tubular transforming growth factor- β1 (TGF-β1) expression may mediate diabetic renal hypertrophy, we investigated the effects of antisense TGF-β1 ODN on the high-glucose-induced proximal tubular epithelial cell hypertrophy in tissue culture and on diabetic renal hypertrophy in vivo. Mouse proximal tubular cells grown in 25 mM d-glucose and exposed to sense ODN as control (1 μM) exhibited increased3[H]leucine incorporation by 120% and total TGF-β1 protein by 50% vs. culture in 5.5 mM d-glucose. Antisense ODN significantly decreased the high-glucose-stimulated TGF-β1 secretion and leucine incorporation. Continuous infusion for 10 days of ODN (100 μg/day) was achieved via osmotic minipumps in diabetic and nondiabetic mice. Sense ODN-treated streptozotocin-diabetic mice had 15.3% increase in kidney weight, 70% increase in α1(IV) collagen and 46% increase in fibronectin mRNA levels compared with nondiabetic mice. Treatment of diabetic mice with antisense ODN partially but significantly decreased kidney TGF-β1 protein levels and attenuated the increase in kidney weight and the α1(IV) collagen and fibronectin mRNAs. In conclusion, therapy with antisense TGF-β1 ODN decreases TGF-β1 production and attenuates high-glucose-induced proximal tubular cell hypertrophy in vitro and partially prevents the increase in kidney weight and extracellular matrix expression in diabetic mice.

scholarly journals High glucose enhances microRNA-26a to activate mTORC1 for mesangial cell hypertrophy and matrix protein expression

2015 ◽  
Vol 27 (7) ◽  
pp. 1276-1285 ◽  
Author(s):  
Nirmalya Dey ◽  
Amit Bera ◽  
Falguni Das ◽  
Nandini Ghosh-Choudhury ◽  
Balakuntalam S. Kasinath ◽  
...  
Keyword(s):  
Protein Expression ◽  
High Glucose ◽  
Matrix Protein ◽  
Mesangial Cell ◽  
Cell Hypertrophy

Cation-independent mannose 6-phosphate receptor inhibitor (PXS25) inhibits fibrosis in human proximal tubular cells by inhibiting conversion of latent to active TGF-β1

2011 ◽  
Vol 301 (1) ◽  
pp. F84-F93 ◽  
Author(s):  
Muh Geot Wong ◽  
Usha Panchapakesan ◽  
Weier Qi ◽  
Diego G. Silva ◽  
Xin-Ming Chen ◽  
...  
Keyword(s):  
High Glucose ◽  
Matrix Protein ◽  
Collagen Iv ◽  
Matrix Proteins ◽  
Matrix Metalloproteinase 2 ◽  
Proximal Tubular Cells ◽  
Tubular Cells ◽  
Hypoxic Conditions ◽  
Proximal Tubular ◽  
Mannose 6 Phosphate

Hyperglycemia and hypoxia have independent and convergent roles in the development of renal disease. Transforming growth factor-β1(TGF-β1) is a key cytokine promoting the production of extracellular matrix proteins. The cationic-independent mannose 6-phosphate receptor (CI-M6PR) is a membrane protein that binds M6P-containing proteins. A key role is to activate latent TGF-β1. PXS25, a novel CI-MPR inhibitor, has antifibrotic properties in skin fibroblasts, but its role in renal fibrosis is unclear. The aim was to study the role of PXS25 in matrix protein production under high glucose ± hypoxic conditions in human proximal tubule (HK-2) cells. HK-2 cells were exposed to high glucose (30 mM) ± 100 μM PXS25 in both normoxic (20% O2) and hypoxic (1% O2) conditions for 72 h. Cellular fibronectin, collagen IV, and matrix metalloproteinase-2 (MMP-2) and MMP-9 were assessed. Total and active TGF-β1were measured by ELISA. High glucose and hypoxia independently induced TGF-β1production. Active TGF-β1, but not total TGF-β1was reduced with concurrent PXS25 in the presence of high glucose, but not in hyperglycemia+hypoxia conditions. Hyperglycemia induced fibronectin and collagen IV production ( P < 0.05), as did hypoxia, but only hyperglycemia-induced increases in matrix proteins were suppressed by concurrent PXS25 exposure. High glucose induced MMP-2 and -9 in normoxic and hypoxic conditions, which was not modified in the presence of PXS25. High glucose and hypoxia can independently induce endogenous active TGF-β1production in human proximal tubular cells. PXS25 inhibits conversion of high glucose-induced release of active TGF-β1, only in the absence of hypoxia.

scholarly journals Reelin Signals through Phosphatidylinositol 3-Kinase and Akt To Control Cortical Development and through mTor To Regulate Dendritic Growth

2007 ◽  
Vol 27 (20) ◽  
pp. 7113-7124 ◽  
Author(s):  
Yves Jossin ◽  
André M. Goffinet
Keyword(s):  
Cortical Neurons ◽  
Hippocampal Neurons ◽  
Matrix Protein ◽  
Glycogen Synthase ◽  
Extracellular Matrix Protein ◽  
Cortical Plate ◽  
Target Cells ◽  
Neuronal Cultures ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphatidylinositol 3

ABSTRACT Reelin is an extracellular matrix protein with various functions during development and in the mature brain. It activates different signaling cascades in target cells, one of which is the phosphatidylinositol 3-kinase (PI3K) pathway, which we investigated further using pathway inhibitors and in vitro brain slice and neuronal cultures. We show that the mTor (mammalian target of rapamycin)-S6K1 (S6 kinase 1) pathway is activated by Reelin and that this depends on Dab1 (Disabled-1) phosphorylation and activation of PI3K and Akt (protein kinase B). PI3K and Akt are required for the effects of Reelin on the organization of the cortical plate, but their downstream partners mTor and glycogen synthase kinase 3β (GSK3β) are not. On the other hand, mTor, but not GSK3β, mediates the effects of Reelin on the growth and branching of dendrites of hippocampal neurons. In addition, PI3K fosters radial migration of cortical neurons through the intermediate zone, an effect that is independent of Reelin and Akt.

Abstract P415: ACE N-domain Regulates High-glucose Mediated Interleukin-1 beta Production by Renal Epithelial Cells Independently From Angiotensin II Generation

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Jorge F Giani ◽  
Ellen A Bernstein ◽  
Masahiro Eriguchi ◽  
Romer A Gonzalez-Villalobos ◽  
Kenneth E Bernstein
Keyword(s):  
Diabetic Nephropathy ◽  
Angiotensin Ii ◽  
Epithelial Cells ◽  
High Glucose ◽  
Interleukin 1 ◽  
Kidney Injury ◽  
Fold Increase ◽  
Renal Epithelial Cells ◽  
Proximal Tubular ◽  
Sense And Respond

Research studies demonstrated that interleukin (IL)-1β contributes to the development of diabetic nephropathy and hypertension. However, the origin and regulation of IL-1β synthesis during diabetic kidney injury are still unknown. Here, we hypothesize that renal epithelial cells produce IL-1β in response to a high glucose stress and that angiotensin converting enzyme (ACE) plays a key role in this process. To study this, we isolated proximal tubular (PT) epithelial cells from wild-type (WT) and mice lacking either the ACE N-domain (NKO) or the C-domain (CKO) catalytic activity. These cells were exposed to normal (5 mM) or high (30 mM) glucose for 24 hours. IL-1β produced by PT cells were assessed by ELISA and RT-PCR. High glucose induced WT PT cells to release significant amounts of IL-1β (from 5±1 to 70±6 pg/ml, p<0.001; n=6). When WT PT cells were exposed to a high glucose media in the presence of an ACE inhibitor (lisinopril, 10 mM), IL-1β levels were significantly reduced (from 70±6 to 38±6 pg/ml, p<0.01). In contrast, AT1 receptor blockade by losartan did not change the amount of IL-1β produced by WT PT cells. To determine which ACE domain is associated with IL-1β production, NKO and CKO PT cells were exposed to high glucose. Strikingly, NKO PT cells released lower amounts of IL-1β when exposed to high glucose compared to WT (NKO: 15±7 vs. WT: 79±9 pg/ml, p<0.01, n=4). No differences were observed between WT and CKO PT cells. Since the ACE N-domain degrades the anti-inflammatory tetrapeptide N-acetyl-Ser-Asp-Lys-Pro (AcSDKP), we tested whether the lower IL-1β production in NKO PT cells was due to an accumulation of AcSDKP. For this, we pre-treated NKO PT cells with a prolyl endopeptidase inhibitor (S17092, 50μM) to prevent the production of AcSDKP. Notably, this treatment increased the IL-1β response to high glucose in NKO PT cells (2.1±0.3-fold increase, p<0.01, n=4). Our data indicate that: 1) PT cells can sense and respond to high glucose by secreting IL-1β and 2) the absence of the ACE N-domain blunts the production of IL-1β through a mechanism that involves AcSDKP accumulation. In conclusion, ACE might contribute to the inflammatory response that underlays diabetic nephropathy independently from angiotensin II generation.

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