scholarly journals The cyclin kinase inhibitor p21WAF1, CIP1 is increased in experimental diabetic nephropathy: potential role in glomerular hypertrophy.

1998 ◽  
Vol 9 (6) ◽  
pp. 986-993 ◽  
Author(s):  
C J Kuan ◽  
M al-Douahji ◽  
S J Shankland

High glucose inhibits mesangial cell proliferation in vitro and induces hypertrophy in mesangial cells in culture and in experimental diabetic nephropathy. Cell growth is ultimately controlled at the level of the cell cycle by cell cycle regulatory proteins. Cell cycle progression requires that cyclin-dependent kinases be activated by cyclins. Cyclin kinase inhibitors (CKI) inactivate cyclin-dependent kinases, causing cell cycle arrest. In the current study, high glucose-induced mesangial cell hypertrophy in vitro is shown to be associated with increased levels of the CKI p21, but not p27. In the streptozotocin model of experimental diabetes in the mouse, glomerular hypertrophy was associated with a selective increase in p21 expression, whereas the levels of the CKI p27 and p57 did not change. Unlike many other forms of glomerular injury, diabetic nephropathy was not associated with increased apoptosis. These results support a role for p21 in causing glomerular cell hypertrophy in diabetic nephropathy.

2021 ◽  
Vol 7 ◽  
Author(s):  
Lin Liao ◽  
Jie Chen ◽  
Chuanfu Zhang ◽  
Yue Guo ◽  
Weiwei Liu ◽  
...  

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Minghua Zhang ◽  
Liang Feng ◽  
Junfei Gu ◽  
Liang Ma ◽  
Dong Qin ◽  
...  

Oxidative stress (OS) has been regarded as one of the major pathogeneses of diabetic nephropathy (DN) through damaging kidney which is associated with renal cells dysfunction. The aim of this study was to investigate whether Moutan Cortex (MC) could protect kidney function against oxidative stressin vitroorin vivo. The compounds in MC extract were analyzed by HPLC-ESI-MS. High-glucose-fat diet and STZ (30 mg kg−1) were used to induce DN rats model, while 200 μg mL−1AGEs were for HBZY-1 mesangial cell damage. The treatment with MC could significantly increase the activity of SOD, glutathione peroxidase (GSH-PX), and catalase (CAT). However, lipid peroxidation malondialdehyde (MDA) was reduced markedlyin vitroorin vivo. Furthermore, MC decreased markedly the levels of blood glucose, serum creatinine, and urine protein in DN rats. Immunohistochemical assay showed that MC downregulated significantly transforming growth factor beta 2 (TGF-β2) protein expression in renal tissue. Our data provided evidence to support this fact that MC attenuated OS in AGEs-induced mesangial cell dysfunction and also in high-glucose-fat diet and STZ-induced DN rats.


2015 ◽  
Vol 309 (3) ◽  
pp. F204-F215 ◽  
Author(s):  
Marimuthu Subathra ◽  
Midhun Korrapati ◽  
Lauren A. Howell ◽  
John M. Arthur ◽  
James A. Shayman ◽  
...  

Glycosphingolipids (GSLs) play a role in insulin resistance and diabetes, but their role in diabetic nephropathy (DN) has received limited attention. We used 9- and 17-wk-old nondiabetic db/ m and diabetic db/ db mice to examine the role of GSLs in DN. Cerebrosides or monoglycosylated GSLs [hexosylceramides (HexCers); glucosyl- and galactosylceramides] and lactosylceramide (LacCers) were elevated in db/ db mouse kidney cortices, specifically in glomeruli, and also in urine. In our recent paper (25), we observed that the kidneys exhibited glomerular hypertrophy and proximal tubular vacuolization and increased fibrosis markers at these time points. Mesangial cells contribute to hyperglycemia-induced glomerular hypertrophy in DN. Hyperglycemic culture conditions, similar to that present in diabetes, were sufficient to elevate mesangial cell HexCers and increase markers of fibrosis, extracellular matrix proteins, and cellular hypertrophy. Inhibition of glucosylceramide synthase or lowering glucose levels decreased markers of fibrosis and extracellular matrix proteins and reversed mesangial cell hypertrophy. Hyperglycemia increased phosphorylated (p)SMAD3 and pAkt levels and reduced phosphatase and tensin homolog levels, which were reversed with glucosylceramide synthase inhibition. These data suggest that inhibition of glucosylceramide synthase reversed mesangial cell hypertrophy through decreased pAkt and pSmad3 and increased pathways responsible for protein degradation. Importantly, urinary GSL levels were higher in patients with DN compared with healthy control subjects, implicating a role for these lipids in human DN. Thus, hyperglycemia in type II diabetes leads to renal dysfunction at least in part by inducing accumulation of HexCers and LacCers in mesangial cells, resulting in fibrosis, extracellular matrix production, and hypertrophy.


2005 ◽  
Vol 388 (2) ◽  
pp. 537-544 ◽  
Author(s):  
Elodie MASSON ◽  
Nicolas WIERNSPERGER ◽  
Michel LAGARDE ◽  
Samer El BAWAB

Alterations in proliferation and hypertrophy of renal mesangial cells are typical features of diabetic nephropathy. The HP (hexosamine pathway) has been proposed as a biochemical hypothesis to explain microvascular alterations due to diabetic nephropathy; however, involvement of HP in the regulation of mesangial cell growth or hypertrophy has been poorly studied. Although gangliosides are known to regulate cell proliferation, their potential role in mesangial cell-growth perturbations has hardly been explored. In the present study, we investigated the effects of the HP activation, mimicked by GlcN (glucosamine) treatment, on mesangial cell growth and hypertrophy and the potential implication of gangliosides in these processes. Our results indicate that GlcN induced hypertrophy of mesangial cells, as measured by an increase in the protein/cell ratio, and it caused cell-cycle arrest by an increase in the expression of cyclin-dependent kinase inhibitor p21Waf1/Cip1. Furthermore, GlcN treatment resulted in a massive increase in the levels of gangliosides GM2 and GM1. Treatment of cells with exogenous GM2 and GM1 reproduced the effects of 0.5 mM GlcN on p21Waf1/Cip1 expression, cell-cycle arrest and hypertrophy, suggesting that gangliosides GM2 and GM1 are probably involved in mediating GlcN effects. These results document a new role of the HP in the regulation of mesangial cell growth and hypertrophy. They also suggest a potential new mechanism of action of the HP through modulation of ganglioside levels.


2009 ◽  
Vol 297 (5) ◽  
pp. F1229-F1237 ◽  
Author(s):  
Danqing Min ◽  
J. Guy Lyons ◽  
James Bonner ◽  
Stephen M. Twigg ◽  
Dennis K. Yue ◽  
...  

Infiltration of macrophages to the kidney is a feature of early diabetic nephropathy. For this to happen monocytes must become activated, migrate from the circulation, and infiltrate the mesangium. This process involves degradation of extracellular matrix, a process mediated by matrix metalloproteinases (MMPs). In the present study we investigate the expression of proinflammatory cytokines TNF-α, IL-6, and MMP-9 in glomeruli of control and diabetic rodents and use an in vitro coculture system to examine whether factors secreted by mesangial cells in response to a diabetic milieu can induce monocyte MMP-9 expression and infiltration. After 8 wk of diabetes, the glomerular level of TNF-α, IL-6, and macrophage number and colocalization of MMP-9 with macrophage were increased ( P < 0.01). Coculture of THP1 monocytes and glomerular mesangial cells in 5 or 25 mM glucose increased MMP-9 (5 mM: 65% and 25 mM: 112%; P < 0.05) and conditioned media degradative activity (5 mM: 30.0% and 25 mM: 33.5%: P < 0.05). These effects were reproduced by addition of mesangial cell conditioned medium to THP1 cells. High glucose (25 mM) increased TNF-α, IL-6, and monocyte chemoattractant protein-1 in mesangial cell conditioned medium. These cytokines all increased adhesion and differentiation of THP1 cells ( P < 0.05), but only TNF-α and IL-6 increased MMP-9 expression (50- and 60-fold, respectively; P < 0.05). Our results show that mesangial cell-secreted factors increase monocyte adhesion, differentiation, MMP expression, and degradative capacity. High glucose could augment these effects by increasing mesangial cell proinflammatory cytokine secretion. This mesangial cell-monocyte interaction may be important in activating monocytes to migrate from the circulation to the kidney in the early stages of diabetic nephropathy.


2015 ◽  
Vol 308 (7) ◽  
pp. F728-F736 ◽  
Author(s):  
Hua Su ◽  
Qiang Wan ◽  
Xiu-Juan Tian ◽  
Fang-Fang He ◽  
Pan Gao ◽  
...  

It is well documented that mitotic arrest deficiency (MAD)2B can inhibit the anaphase-promoting complex/cyclosome (APC/C) via cadherin (Cdh)1 and, consequently, can destroy the effective mitotic spindle checkpoint control. Podocytes have been observed to rapidly detach and die when being forced to bypass cell cycle checkpoints. However, the role of MAD2B, a cell cycle regulator, in podocyte impairment of diabetic nephropathy (DN) is unclear. In the present study, we investigated the significance of MAD2B in the pathogenesis of DN in patients, an animal model, and in vitro podocyte cultures. By Western blot and immunohistochemistry analyses, we found that MAD2B was evidently upregulated under high glucose milieu in vivo and in vitro, whereas Cdh1 was inhibited with high glucose exposure. Overexpression of MAD2B in podocytes by plasmid DNA transfection suppressed expression of Cdh1 and triggered the accumulation of cyclin B1 and S phase kinase-associated protein (Skp)2, two key molecules involving in cell cycle regulation, and the subsequent podocyte insult. In contrast, MAD2B deletion alleviated the high glucose-induced reduction of Cdh1 as well as the elevation of cyclin B1 and Skp2, which rescued the podocyte from damage. Taken together, our data demonstrate that MAD2B may play an important role in high glucose-mediated podocyte injury of DN via modulation of Cdh1, cyclin B1, and Skp2 expression.


2020 ◽  
Vol 28 (3) ◽  
pp. 963-974 ◽  
Author(s):  
Yi-Chun Tsai ◽  
Mei-Chuan Kuo ◽  
Wei-Wen Hung ◽  
Ling-Yu Wu ◽  
Ping-Hsun Wu ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 334
Author(s):  
Ashraf N. Abdalla ◽  
Waleed H. Malki ◽  
Amal Qattan ◽  
Imran Shahid ◽  
Mohammad Akbar Hossain ◽  
...  

Colorectal cancer (CRC) remains one of the main causes of death worldwide and in Saudi Arabia. The toxicity and the development of resistance against 5 fluorouracil 5FU pose increasing therapeutic difficulties, which necessitates the development of personalized drugs and drug combinations. Objectives: First, to determine the most important kinases and kinase pathways, and the amount of ABC transporters and KRAS in samples taken from Saudi CRC patients. Second, to investigate the chemosensitizing effect of LY294002 and HAA2020 and their combinations with 5FU on HT29, HT29-5FU, HCT116, and HCT116-5FU CRC cells, their effect on the three ABC transporters, cell cycle, and apoptosis, in light of the important kinase pathways resulting from the first part of this study. Methods: The PamChip® peptide micro-array profiling was used to determine the level of kinase and targets in the Saudi CRC samples. Next, RT-PCR, MTT cytotoxicity, Western blotting, perturbation of cell cycle, annexin V, and immunofluorescence assays were used to investigate the effect on CRC, MRC5, and HUVEC cells. Results: The kinase activity profiling highlighted the importance of the PI3K/AKT, MAPK, and the growth factors pathways in the Saudi CRC samples. PIK3CA was the most overexpressed, and it was associated with increased level of mutated KRAS and the three ABC transporters, especially ABCC1 in the Saudi samples. Next, combining HAA2020 with 5FU exhibited the best synergistic and resistance-reversal effect in the four CRC cells, and the highest selectivity indices compared to MRC5 and HUVEC normal cells. Additionally, HAA2020 with 5FU exerted significant inhibition of ABCC1 in the four CRC cells, and inhibition of PIK3CA/AKT/MAPK7/ERK in HT29 and HT29-5FU cells. The combination also inhibited EGFR, increased the preG1/S cell cycle phases, apoptosis, and caspase 8 in HT29 cells, while it increased the G1 phase, p21/p27, and apoptosis in HT29-5FU cells. Conclusion: We have combined the PamChip kinase profiling of Saudi CRC samples with in vitro drug combination studies in four CRC cells, highlighting the importance of targeting PIK3CA and ABCC1 for Saudi CRC patients, especially given that the overexpression of PIK3CA mutations was previously linked with the lack of activity for the anti-EGFRs as first line treatment for CRC patients. The combination of HAA2020 and 5FU has selectively sensitized the four CRC cells to 5FU and could be further studied.


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