scholarly journals Effect of Elevated Glucose on Endothelin-Induced Store-Operated and Non-Store-Operated Calcium Influx in Renal Mesangial Cells

2000 ◽  
Vol 11 (7) ◽  
pp. 1225-1235
Author(s):  
LETA K. NUTT ◽  
ROGER G. O'NEIL
Keyword(s):  
Calcium Signaling ◽  
High Glucose ◽  
Mesangial Cells ◽  
Calcium Influx ◽  
Calcium Entry ◽  
Calcium Signal ◽  
Glomerular Mesangial Cells ◽  
Glucose Levels ◽  
Elevated Glucose ◽  
Acute And Chronic Exposure

Abstract. Early diabetic nephropathy exhibits renal glomerular hyperfiltration and an increase in renal plasma flow. The hyperfiltration is a dysfunctional state that may arise from a hyperglycemic-induced hypocontractility of glomerular mesangial cells that may be associated with depressed Ca2+signaling events. The present study was designed to determine the effects of acute (minutes) and chronic (days) elevated glucose levels on endothelin-induced calcium signaling with a particular emphasis on the potential influence on stores and store-operated Ca2+influx (SOCI ; also called capacitative calcium entry) in glomerular mesangial cells. Primary cultures of rat mesangial cells were grown in either high (30 mM) or normal (5 mM) glucose-containing media and tested in the presence of either high (30 mM) or normal (5 mM) glucose levels. Intracellular calcium levels were monitored with the calcium-sensitive fluorophore fura-2 before and after treatment with either endothelin-1 (10 nM), to induce typical Ca2+signals, or the endoplasmic reticulum (ER) Ca-ATPase inhibitor thapsagargin (1 μM), to unload ER Ca2+stores. Both acute and chronic exposure to high glucose levels depressed the endothelin-induced calcium signal. However, neither release of Ca2+from stores nor SOCI were depressed by high glucose levels. In contrast, an endothelin-induced calcium entry pathway (likely receptor-operated calcium influx), separate from SOCI, was markedly depressed in the presence of both acute and chronic high glucose levels. The depressant effect of high glucose was rapidly (minutes) reversible upon returning to normal glucose levels. It is concluded that high glucose levels depress endothelin-induced calcium signaling in rat mesangial cells by inhibiting non-SOCI Ca2+entry pathways, namely the receptor-operated Ca2+influx pathway. The glucose-induced alterations in the receptor-operated calcium influx pathway may, in part, contribute to the depressed contractile state of glomerular cells during periods of hyperglycemia.

scholarly journals Trigonelline regulates Wnt/β-catenin signaling in glomerular mesangial cells under high glucose conditions

2021 ◽  
Author(s):  
Chen Chen ◽  
Yan Shi ◽  
Zhen Chen ◽  
Xiangjun Li ◽  
Bo Sun ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Flow Cytometry ◽  
High Glucose ◽  
Cell Cycle Progression ◽  
Cell Injury ◽  
Mesangial Cells ◽  
Animal Experiments ◽  
Glomerular Mesangial Cells ◽  
Glucose Levels ◽  
Elevated Glucose

Abstract Background: Trigonelline have hypoglycemic effects. In previous animal experiments, we observed that trigonelline (TRL) treat-ment attenuated metabolic abnormalities associated with hyperglycemic conditions in the experimental DN model. In streptozotocin (STZ)-induced rats, TRL treatment reduced albuminuria, lowered blood sugar, improved renal function and alleviated the pathological alterations within the glomerulus. Methods: We stimulated human mesangial cells (HMC) with high glucose (30 mmol / L) medium. HMCs were transfected with β-catenin plasmid or siRNA to investigate the effect of trigonelline on high glucose-induced excessive proliferation and apoptosis of HMCs, and to understand its mechanism of action. Cell viability was measured by MTT assay. Flow cytometry was used to detect the cell cycle. Cell apoptosis was evaluated by flow cytometry and terminal dUTP transferase nick end labeling (TUNEL) assay. Protein and mRNA expression of β-catenin, Wnt5a, TCF4, Cyclin D1, and CDK4 were detected by western blotting and RT-PCR, respectively. Results: Trigonelline inhibited cell proliferation by blocking cell-cycle progression at the G1 phase and decreased apoptosis via the Wnt/β-catenin pathway. Elevated glucose levels enhanced the expression of β-catenin, an important modulator of diabetic nephropathy, while trigonelline restored up-regulation. Conclusions: High glucose and high expression of β-catenin could lead to cell injury; however, this effect was mitigated by trigonelline via managing the canonical Wnt/β-catenin signaling pathway.

scholarly journals Influence of Acute High Glucose on Protein Abundance Changes in Murine Glomerular Mesangial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Michelle T. Barati ◽  
James C. Gould ◽  
Sarah A. Salyer ◽  
Susan Isaacs ◽  
Daniel W. Wilkey ◽  
...  
Keyword(s):  
Protein Expression ◽  
Posttranslational Modifications ◽  
High Glucose ◽  
Mesangial Cells ◽  
Expression Patterns ◽  
Growth Conditions ◽  
Glomerular Mesangial Cells ◽  
Two Dimensional Gel Electrophoresis ◽  
Glucose Levels ◽  
Flight Mass Spectrometry

The effects of acute exposure to high glucose levels as experienced by glomerular mesangial cells in postprandial conditions and states such as in prediabetes were investigated using proteomic methods. Two-dimensional gel electrophoresis and matrix assisted laser desorption ionization time of flight mass spectrometry methods were used to identify protein expression patterns in immortalized rat mesangial cells altered by 2 h high glucose (HG) growth conditions as compared to isoosmotic/normal glucose control (NG⁎) conditions. Unique protein expression changes at 2 h HG treatment were measured for 51 protein spots. These proteins could be broadly grouped into two categories: (1) proteins involved in cell survival/cell signaling and (2) proteins involved in stress response. Immunoblot experiments for a protein belonging to both categories, prohibitin (PHB), supported a trend for increased total expression as well as significant increases in an acidic PHB isoform. Additional studies confirmed the regulation of proteasomal subunit alpha-type 2 and the endoplasmic reticulum chaperone and oxidoreductase PDI (protein disulfide isomerase), suggesting altered ER protein folding capacity and proteasomal function in response to acute HG. We conclude that short term high glucose induces subtle changes in protein abundances suggesting posttranslational modifications and regulation of pathways involved in proteostasis.

scholarly journals CYLD Deubiquitinase Negatively Regulates High Glucose-Induced NF-κB Inflammatory Signaling in Mesangial Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Yanhui Li ◽  
Wei Huang ◽  
Youhua Xu ◽  
Luping Zhou ◽  
Yaling Liang ◽  
...  
Keyword(s):  
High Glucose ◽  
Mesangial Cells ◽  
Pressure Control ◽  
Ubiquitin Proteasome System ◽  
Negative Regulator ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Inflammatory Signaling ◽  
Mediated Effects ◽  
Elevated Glucose

Nuclear factor-kappa B (NF-κB) is the key part of multiple signal transduction of inflammation in the pathogenesis of diabetic nephropathy (DN). The ubiquitin-proteasome system is extensively involved in the regulation of the NF-κB pathway. Cylindromatosis (CYLD) has deubiquitinase activity and acts as a negative regulator of the NF-κB signaling pathway. However, the association between CYLD and NF-κB inflammatory signaling in DN is unclear. In the present study, mouse glomerular mesangial cells (GMCs) and rat GMCs were stimulated by elevated concentrations of glucose (10, 20, and 30 mmol/L high glucose) or mannitol as the osmotic pressure control. CYLD was overexpressed or suppressed by transfection with a CYLD expressing vector or CYLD-specific siRNA, respectively. Our data showed that high glucose significantly inhibited the protein and mRNA expression of CYLD in a dose- and time-dependent manner (both p<0.05). siRNA-mediated knockdown CYLD facilitated the high glucose-induced activation of NF-κB signaling and triggered the release of MCP-1, IL-6, and IL-8 (all p<0.05). However, these high glucose-mediated effects were blunted by overexpression of CYLD (p<0.05). The present results support the involvement of CYLD in the regulation of NF-κB inflammatory signaling induced by elevated glucose, implicating CYLD as a potential therapeutic target of DN.

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.

Increased extracellular matrix synthesis and mRNA in mesangial cells grown in high-glucose medium

1991 ◽  
Vol 260 (2) ◽  
pp. F185-F191 ◽  
Author(s):  
S. H. Ayo ◽  
R. A. Radnik ◽  
W. F. Glass ◽  
J. A. Garoni ◽  
E. R. Rampt ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Protein Synthesis ◽  
High Glucose ◽  
Mesangial Cells ◽  
Matrix Proteins ◽  
Cell Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mrna Levels ◽  
Glomerular Mesangial Cells ◽  
Glomerular Mesangium

Nodular expansion of glomerular mesangium with increased amounts of extracellular matrix (ECM) material is pathognomic of diabetic nephropathy. The precise mechanisms involved in this accumulation are unknown. Recently, we reported using a solid-phase enzyme-linked immunosorbent assay (ELISA) technique that glomerular mesangial cells, the principal cell type residing in glomerular mesangium, accumulate 50–60% more fibronectin (FN), laminin (LM), and type IV collagen (T-IV) when cultured in medium containing high glucose (30 mM) (S. H. Ayo, R. A. Rodnik, J. Garoni, W. F. Glass II, and J. I. Kreiberg. Am. J. Pathol. 136: 1339-1348, 1990). ECM assembly is controlled by its rate of synthesis and degradation, as well as its binding and rate of incorporation into the ECM. To elucidate the mechanisms involved, pulse-chase experiments were designed to estimate ECM protein synthesis from the incorporation of Trans-35S [( 35S]methionine, [35S]cysteine) into immunoprecipitated FN, LM, and T-IV. mRNA levels were examined, and degradation rates were estimated from the disappearance of radioactivity from matrix proteins in mesangial cells previously incubated with Trans-35S. One week of growth in 30 mM glucose resulted in approximately 40–50% increase in the synthesis of all three matrix proteins compared with 10 mM glucose-grown cells. This was accompanied by a significant increase in the transcripts for all three matrix proteins (approximately twofold). The specific activity of the radiolabel in trichloroacetic acid-precipitable cell protein showed no difference between cells grown in 10 or 30 mM glucose, indicating that total protein synthesis was unchanged. After 1 wk, the rate of FN, LM, and T-IV collagen degradation was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

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