Proteomic profile of primary isolated rat mesangial cells in high-glucose culture condition and decreased expression of PSMA6 in renal cortex of diabetic ratsThis paper is one of a selection of papers published in this special issue entitled “Second International Symposium on Recent Advances in Basic, Clinical, and Social Medicine” and has undergone the Journal's usual peer review process.

2010 ◽  
Vol 88 (4) ◽  
pp. 635-648 ◽  
Author(s):  
Zhiguo Li ◽  
Haojun Zhang ◽  
Xi Dong ◽  
Frank J. Burczynski ◽  
Patrick Choy ◽  
...  

Diabetic nephropathy (DN) is one of the most important complications of diabetic patients and is characterized histologically by an accumulation of extracellular matrix (ECM) protein in the glomerular mesangium. Therefore, mesangial cells likely play an important role in the development of diabetic nephropathy. Here, we employed proteomic techniques to investigate the protein profile of rat mesangial cells under high-glucose culture conditions. Primary isolated rat glomerular mesangial cells were cultured under different concentrations of glucose (5.4 mmol·L–1 for normal control and 30 mmol·L–1 for high glucose) for 0, 8, 16, and 72 h, as well as for 25 days. Cellular total proteins were isolated from these cells and employed for two-dimensional gel electrophoresis (2-DE). Differentially expressed proteins were identified by matrix-assisted laser desorption – ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and some of these proteins were documented in rat models of diabetes by Western blot. Rat mesangial cells were successfully isolated in the laboratory and their proliferation rates were significantly inhibited by high glucose. Two-dimensional gel electrophoresis analyses revealed 28 differentially expressed protein spots between the normal and high-glucose groups. After MALDI-TOF-MS analysis, all 28 protein spots were successfully identified with the peptide mass fingerprint (PMF) method. Representatively, SOD1, PCBP1 and PSMA6 were validated by Western blot analysis following protein extractions from the normal and high-glucose groups. Abundance of these proteins was consistent with that found in 2-DE. Moreover, expression of SOD1, PCBP1, and PSMA6 in renal cortex was further examined in two rat models of diabetes (streptozotocin-induced and spontaneous OLETF diabetic models). Abundance of SOD1 and PCBP1 proteins did not show any significant difference between normal control and diabetic rats. However, abundance of the PSMA6 protein was significantly reduced in the renal cortex of both STZ-induced and spontaneous OLETF diabetic rats. Proteomic analysis identified 28 differentially expressed proteins in primary isolated rat mesangial cells between normal and high glucose treatments. Expression of one identified protein was found to be consistent with expression in the renal cortex of two rat diabetic models. Therefore, identification of protein expression patterns in mesangial cells can be employed to develop a therapeutic target for treatment of diabetic nephropathy.

2011 ◽  
Vol 115 (4) ◽  
pp. 789-795 ◽  
Author(s):  
Zhengping Zhuang ◽  
Meng Qi ◽  
Jie Li ◽  
Hiroaki Okamoto ◽  
David S. Xu ◽  
...  

Object Astrocytomas and oligodendrogliomas are primary CNS tumors that remain a challenge to differentiate histologically because of their morphological variability and because there is a lack of reliable differential diagnostic markers. To identify proteins that are differentially expressed between astrocytomas and oligodendrogliomas, the authors analyzed the proteomic expression patterns and identified uniquely expressed proteins in these neoplasms. Methods Proteomes of astrocytomas and oligodendrogliomas were analyzed using 2D gel electrophoresis and subsequent computerized gel analysis to detect differentially expressed proteins. The proteins were identified using high-performance liquid chromatography accompanied by tandem mass spectrometry. To determine the role of the differentially expressed proteins in astrocytes, undifferentiated glial cell cultures were treated with dibutyryl–cyclic adenosine monophosphate (cAMP). Results Two-dimensional gel electrophoresis revealed that glutamine synthetase was differentially expressed in astrocytomas and oligodendrogliomas. Western blot and immunohistochemical analyses confirmed the increased expression of glutamine synthetase in astrocytomas compared with oligodendrogliomas. Whereas glutamine synthetase expression was demonstrated across all grades of astrocytomas (Grade II–IV [15 tumors]) and oligoastrocytomas (4 tumors), it was expressed in only 1 oligodendroglioma (6% [16 tumors]). Treatment of undifferentiated glial cell cultures with dibutyryl-cAMP resulted in astrocyte differentiation that was associated with increased levels of glial fibrillary acidic protein and glutamine synthetase. Conclusions These data indicate that glutamine synthetase expression can be used to distinguish astrocytic from oligodendroglial tumors and may play a role in the pathogenesis of astrocytomas.


2009 ◽  
Vol 297 (3) ◽  
pp. F822-F834 ◽  
Author(s):  
D. Wu ◽  
F. Peng ◽  
B. Zhang ◽  
A. J. Ingram ◽  
D. J. Kelly ◽  
...  

Glomerular matrix accumulation is a hallmark of diabetic nephropathy. We have recently shown that epidermal growth factor receptor (EGFR) transactivation mediates high glucose (HG)-induced collagen I upregulation through PI3K-PKCβ1-Akt signaling in mesangial cells (MC). Phospholipase Cγ1 (PLCγ1) interacts with activated growth factor receptors and activates classic PKC isoforms. We thus studied its role in HG-induced collagen I upregulation in MC. Primary rat MC were treated with HG (30 mM) or mannitol as osmotic control. Protein kinase activation was assessed by Western blotting and collagen I upregulation by Northern blotting. Diabetes was induced in rats by streptozotocin. HG treatment for 1 h led to PLCγ1 membrane translocation and Y783 phosphorylation, both indicative of its activation. Mannitol was without effect. PLCγ1 Y783 phosphorylation was also seen in cortex and glomeruli of diabetic rats. HG induced a physical association between EGFR and PLCγ1 as identified by coimmunoprecipitation. PLCγ1 activation required EGFR kinase activity since it was prevented by the EGFR inhibitor AG1478 or overexpression of kinase-inactive EGFR (K721A). Phosphoinositide-3-OH kinase inhibition also prevented PLCγ1 activation. HG-induced Akt S473 phosphorylation, effected by PKCβ1, was inhibited by the PLCγ inhibitor U73122. PLCγ1 inhibition or downregulation by small interference RNA also prevented HG-induced collagen I upregulation. Our results indicate that EGFR-PLCγ1 signaling mediates HG-induced PKCβ1-Akt activation and subsequent collagen I upregulation in MC. Inhibition of EGFR or PLCγ1 may provide attractive therapeutic targets for the treatment of diabetic nephropathy.


2021 ◽  
Vol 22 (9) ◽  
pp. 4741
Author(s):  
Makiyo Okamura ◽  
Noboru Fukuda ◽  
Shu Horikoshi ◽  
Hiroki Kobayashi ◽  
Akiko Tsunemi ◽  
...  

Upstream stimulatory factor 1 (USF1) is a transcription factor that is increased in high-glucose conditions and activates the transforming growth factor (TGF)-β1 promoter. We examined the effects of synthetic pyrrole-imidazole (PI) polyamides in preventing USF1 binding on the TGF-β1 promoter in Wistar rats in which diabetic nephropathy was established by intravenous administration of streptozotocin (STZ). High glucose induced nuclear localization of USF1 in cultured mesangial cells (MCs). In MCs with high glucose, USF1 PI polyamide significantly inhibited increases in promoter activity of TGF-β1 and expression of TGF-β1 mRNA and protein, whereas it significantly decreased the expression of osteopontin and increased that of h-caldesmon mRNA. We also examined the effects of USF1 PI polyamide on diabetic nephropathy. Intraperitoneal injection of USF1 PI polyamide significantly suppressed urinary albumin excretion and decreased serum urea nitrogen in the STZ-diabetic rats. USF1 PI polyamide significantly decreased the glomerular injury score and tubular injury score in the STZ-diabetic rats. It also suppressed the immunostaining of TGF-β1 in the glomerulus and proximal tubules and significantly decreased the expression of TGF-β1 protein from kidney in these rats. These findings indicate that synthetic USF1 PI polyamide could potentially be a practical medicine for diabetic nephropathy.


2008 ◽  
Vol 109 (3) ◽  
pp. 536-546 ◽  
Author(s):  
Jie Li ◽  
Hiroaki Okamoto ◽  
Chunyue Yin ◽  
Jay Jagannathan ◽  
Jun Takizawa ◽  
...  

Object The lack of primary lymphoid tissue within the central nervous system (CNS) confounds our understanding of the pathogenesis of primary CNS lymphomas (PCNSLs). Comparing the protein expression of PCNSLs and sporadic systemic lymphomas (SSLs) provides a useful strategy for identifying a molecular signature that characterizes disease-associated features and provides information regarding tumor initiation and progression. Methods Seven diffuse large B-cell PCNSLs were selected to undergo 2D gel electrophoresis, and profiled proteomes from these PCNSLs were compared with those from 7 diffuse large B-cell SSLs. Distinguishing proteins were sequenced using mass spectrometry. Results Two-dimensional gel electrophoresis identified an average of 706 proteins from each specimen. Computerized gel analysis and manual reconfirmation revealed a 96% similarity in the proteomes of PCNSLs and SSLs. Comparative analysis identified 9 proteins significantly overexpressed (p < 0.05) and 16 proteins downregulated in PCNSLs. The proteomic findings were further validated using Western blot and immunohistochemical staining. Conclusions The similarities in proteomic patterns between PCNSLs and SSLs suggest that these tumor types share structural similarities, acquired during differentiation. The ultimate fate of lymphomatous cells (CNS vs systemic) may be related to differentially expressed proteins, which function in homing and host processing. Elucidating the roles of these differentially expressed proteins will prove valuable in understanding the pathogenesis of PCNSL.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jie Yun ◽  
Jinyu Ren ◽  
Yufei Liu ◽  
Lijuan Dai ◽  
Liqun Song ◽  
...  

Abstract Background Circular RNAs (circRNAs) have been considered as pivotal biomarkers in Diabetic nephropathy (DN). CircRNA ARP2 actin-related protein 2 homolog (circ-ACTR2) could promote the HG-induced cell injury in DN. However, how circ-ACTR2 acts in DN is still unclear. This study aimed to explore the molecular mechanism of circ-ACTR2 in DN progression, intending to provide support for the diagnostic and therapeutic potentials of circ-ACTR2 in DN. Methods RNA expression analysis was conducted by the quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Cell growth was measured via Cell Counting Kit-8 and EdU assays. Inflammatory response was assessed by Enzyme-linked immunosorbent assay. The protein detection was performed via western blot. Oxidative stress was evaluated by the commercial kits. The molecular interaction was affirmed through dual-luciferase reporter and RNA immunoprecipitation assays. Results Circ-ACTR2 level was upregulated in DN samples and high glucose (HG)-treated human renal mesangial cells (HRMCs). Silencing the circ-ACTR2 expression partly abolished the HG-induced cell proliferation, inflammation and extracellular matrix accumulation and oxidative stress in HRMCs. Circ-ACTR2 was confirmed as a sponge for miR-205-5p. Circ-ACTR2 regulated the effects of HG on HRMCs by targeting miR-205-5p. MiR-205-5p directly targeted high-mobility group AT-hook 2 (HMGA2), and HMGA2 downregulation also protected against cell injury in HG-treated HRMCs. HG-mediated cell dysfunction was repressed by miR-205-5p/HMGA2 axis. Moreover, circ-ACTR2 increased the expression of HMGA2 through the sponge effect on miR-205-5p in HG-treated HRMCs. Conclusion All data have manifested that circ-ACTR2 contributed to the HG-induced DN progression in HRMCs by the mediation of miR-205-5p/HMGA2 axis.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hong Feng ◽  
Junling Gu ◽  
Fang Gou ◽  
Wei Huang ◽  
Chenlin Gao ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document