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Mesangial Cells (mesangial + cell)
Kinds of Mesangial Cells Terms modified by Mesangial Cells Selected AbstractsMesangial cell proliferation inhibitors for the treatment of proliferative glomerular diseaseMEDICINAL RESEARCH REVIEWS, Issue 1 2003Yasuhisa Kurogi Abstract Mesangial cells (MC) serve a number of functions in the renal glomerular capillary including structural support of the capillary tuft, modulation of glomerular hemodynamics, and a phagocytic function allowing removal of macromolecules and immune complexes. The proliferation of MC is a prominent feature of glomerular disease including IgA nephropathy, membranoproliferative glomerulonephritis, lupus nephritis, and diabetic nephropathy. In experimental animal models of nephritis, MC proliferation frequently precedes and is linked to the increase of extracellular matrix in the mesangium and glomerulosclerosis. Reduction of MC proliferation in glomerular disease models by treatment with heparin, low-protein diet, or antibodies to platelet-derived growth factor (PDGF), have been shown to reduce extracellular matrix expansion and glomerulosclerotic changes. Therefore, MC proliferation inhibitors may offer therapeutic opportunities for the treatment of proliferative glomerular disease. It is also known that the MC proliferation is inhibited by many kinds of pharmacological drugs, for example, angiotensin converting enzyme (ACE) inhibitors, leukotriene D4 (LTD4) antagonists, PDGF inhibitors, matrix metalloproteinases (MMP) inhibitors, 3-hydroxy-3 methyl glutaryl-coenzymeA (HMG-CoA) inhibitors, cyclin-dependent kinases (CDK) inhibitors, and others. This review summarizes the recently reported MC proliferation inhibitors with their pharmacological properties on the basis of their chemical structures. © 2002 Wiley Periodicals, Inc. Med Res Rev, 23, No. 1, 15,31, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/med.10028 [source] Genomic repertoire of human mesangial cells: comprehensive analysis of gene expression by cDNA array hybridizationNEPHROLOGY, Issue 4 2000Naohiro Yano SUMMARY: Knowing when and where a gene is expressed in a cell often provides a strong clue as to its physiological role. It is estimated the human genome contains 80 000,100 000 genes. Assessment of gene activity on a global genome-wide scale is a fundamental and newly developed experimental strategy to expand the scope of biological investigation from a single gene to studying all genes at once in a systematic way. Capitalizing on the recently developed methodology of cDNA array hybridization, we monitored the simultaneous expression of thousands of genes in primary human mesangial cells. Complex ,- 33P-labelled cDNA probes were prepared from cultured mesangial cells. The probe was hybridized to a high-density array of 18 326 paired target genes. The radioactive hybridization signals were analysed by phosphorimager. Bioinformatics from public genomic databases was utilized to assign a chromosomal location of each expressed transcript. Approximately 7460 different gene transcripts were detected in mesangial cells. Close to 13% (957 genes) were full-length mRNA human transcripts (HTs), the remainder 6503 being expressed sequence tags (ESTs). Using special imaging computer software, the transcriptional level of the 957 HTs was compared with the expression of the ribosomal protein S28 (housekeeping gene). The HTs were also classified by function of the gene product and listed with information on their chromosomal loci. To allow comparison between clinical and experimental studies of gene expression, the detected human gene transcripts were cross-referenced to orthologous mouse genes. Thus, the presented data constitute a quantitative preliminary blueprint of the transcriptional map of the human mesangial cell. The information may serve as a resource for speeding up the discovery of genes underlying human glomerular diseases. The complete listing of the full-length expressed genes is available upon request via E-mail: (Abdalla_Rifai@Brown.edu). [source] The ,II isotype of tubulin is present in the cell nuclei of a variety of cancersCYTOSKELETON, Issue 2 2004I-Tien Yeh Abstract Tubulin, the subunit protein of microtubules, has generally been thought to be exclusively a cytoplasmic protein in higher eukaryotes. We have previously shown that cultured rat kidney mesangial cells contain the ,II isotype of tubulin in their nuclei in the form of an ,,II dimer [Walss et al., 1999: Cell Motil. Cytoskeleton 42:274,284, 1999]. More recently, we examined a variety of cancerous and non-cancerous cell lines and found ,II in the nuclei of all of the former and only a few of the latter (Walss-Bass et al., 2002: Cell Tissue Res. 308:215,223]. In order to determine if ,II -tubulin occurs in the nuclei of actual cancers as well as in cancer cell lines, we used the immunoperoxidase method to look for nuclear ,II in a variety of tumors excised from 201 patients. We found that 75% of these tumors contain ,II in their nuclei. Distribution of nuclear ,II was highly dependent on the type of cancer, with 100% of the colon and prostate cancers, but only 19% of the skin tumors, having nuclear ,II. Nuclear ,II was particularly marked in tumors of epithelial origin, of which 83% showed nuclear ,II, in contrast to 54% in tumors of non-epithelial origin. In many cases, ,II staining occurred very strongly in the nuclei and not in the cytoplasm; in other cases, ,II was present in both. In many cases, particularly metastases, otherwise normal cells adjacent to the tumor also showed nuclear ,II, suggesting that cancer cells may influence nearby cells to synthesize ,II and localize it to their nuclei. Our results have implications for the diagnosis, biology, and chemotherapy of cancer. Cell Motil. Cytoskeleton 57:96,106, 2004. © 2004 Wiley-Liss, Inc. [source] Advanced glycation end products-induced apoptosis attenuated by PPAR, activation and epigallocatechin gallate through NF-,B pathway in human embryonic kidney cells and human mesangial cellsDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 5 2010Yao-Jen Liang Abstract Background Diabetic nephropathy has attracted many researchers' attention. Because of the emerging evidence about the effects of advanced glycation end products (AGEs) and receptor of AGE (RAGE) on the progression of diabetic nephropathy, a number of different therapies to inhibit AGE or RAGE are under investigation. The purpose of the present study was to examine whether peroxisome proliferator-activated receptor , (PPAR,) agonist (L-165041) or epigallocatechin gallate (EGCG) alters AGE-induced pro-inflammatory gene expression and apoptosis in human embryonic kidney cells (HEK293) and human mesangial cells (HMCs). Methods The HEK cells and HMC were separated into the following groups: 100 µg/mL AGE alone for 18 h; AGE treated with 1 µM L-165041 or 10 µM EGCG, and untreated cells. Inflammatory cytokines, nuclear factor-,B pathway, RAGE expression, superoxide dismutase and cell apoptosis were determined. Results AGE significantly increased tumour necrosis factor-, (TNF-,), a major pro-inflammatory cytokine. The mRNA and protein expression of RAGE were up-regulated. These effects were significantly attenuated by pre-treatment with L-165041 or EGCG. AGE-induced nuclear factor-,B pathway activation and both cells apoptosis were also inhibited by L-165041 or EGCG. Furthermore, both L-165041 and EGCG increased superoxide dismutase levels in AGE-treated HEK cells and HMC. Conclusions This study demonstrated that PPAR, agonist and EGCG decreased the AGE-induced kidney cell inflammation and apoptosis. This study provides important insights into the molecular mechanisms of EGCG and PPAR, agonist in attenuation of kidney cell inflammation and may serve as a therapeutic modality to treat patients with diabetic nephropathy. Copyright © 2010 John Wiley & Sons, Ltd. [source] Collagen type VIII expression in human diabetic nephropathyEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2007J. Gerth Abstract Background, Collagen type VIII is a non-fibrillar short-chain collagen that may modulate migration, proliferation and adherence of various cells. Only very sparse information exists on collagen type VIII expression in human diabetic nephropathy. Material and methods, We retrospectively studied mRNA expression for the two collagen type VIII chains (COL8A1 and COL8A2) in 20 biopsies with histologically confirmed diabetic nephropathy by real-time PCR, and compared glomerular and tubular expression with normal kidney [pre-transplant biopsies (n = 10)]. Expression of collagen type VIII was also studied in biopsies from patients with benign nephrosclerosis (BNS; n = 16) and focal-segmental glomerulosclerosis (FSGS; n = 9). Results, A strong specific induction of COL8A1 mRNA was found in diabetic nephropathy in both glomerular and tubular compartments. There was also a robust induction of COL8A2 in diabetic nephropathy, but overall expression was lower than that of COL8A1 transcripts. No significant increase in COL8A1 and COL8A2 mRNAs expression was found in biopsies from patients with BNS and FSGS compared with normal kidneys. The cross-reactivity of the used anti-,1(VIII) antibody with human tissue was confirmed by Western blots. Immunohistological analysis revealed only little staining for collagen type VIII in the normal kidney, localized to vessels. There was an up-regulation of collagen type VIII protein expression as shown by immunohistochemistry in the diabetic nephropathy biopsies mainly localized to mesangial cells, tubules and the interstitium. Proteinuria and serum creatinine did not correlate with glomerular or tubular COL8A1 and COL8A2 mRNA expression in diabetic patients. Conclusion, Our study systemically investigates collagen type VIII expression in human biopsies. Induction of collagen type VIII was specific for diabetic nephropathy and did not occur in the other renal diseases studied. More specific factors of the diabetic environment are likely involved in the stimulated expression because there was no correlation of collagen type VIII mRNA expression with proteinuria. Since collagen type VIII may influence proliferation and migration of cells, it is possible that an increase in renal expression of collagen type VIII initiates other pathophysiological processes (e.g. proliferation of renal fibroblasts) involved in diabetic nephropathy. [source] Activation of the Nrf2/antioxidant response pathway increases IL-8 expressionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2005Xiaolan Zhang Abstract Oxidant stress can initiate or enhance inflammatory responses during tissue injury, possibly through activation of redox-sensitive chemokines. Because the transcription factor Nrf2 (NF-E2-related factor,2) is responsive to oxidative stress, and induces expression of cytoprotective and antioxidant genes that attenuate tissue injury, we postulated that Nrf2 may also regulate chemokine expression. To test this hypothesis, Nrf2 expression was directly increased in primary human kidney mesangial cells and aortic endothelial cells, or cell lines with an adenoviral construct, and the effects on the pro-inflammatory chemokine interleukin-8 (IL-8) were assessed. Nrf2 expression significantly increased IL-8 mRNA levels and protein secretion. Nrf2 caused only a weak induction of IL-8 transcription, but significantly increased the half-life of IL-8 mRNA. These data demonstrate that activation of the Nrf2/antioxidant response pathway induces expression of IL-8. The dominant mechanism of Nrf2-mediated IL-8 induction is through mRNA stabilization. Considering the evidence that Nrf2 activation is mainly cytoprotective, these observations raise the possibility that under certain circumstances IL-8 may serve an anti-inflammatory role and thereby contribute to the resolution of tissue injury. See accompanying commentary http://dx.doi.org/10.1002/eji.200535489 [source] Astaxanthin protects mesangial cells from hyperglycemia-induced oxidative signaling,JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2008Emiko Manabe Abstract Astaxanthin (ASX) is a carotenoid that has potent protective effects on diabetic nephropathy in mice model of type 2 diabetes. In this study, we investigated the protective mechanism of ASX on the progression of diabetic nephropathy using an in vitro model of hyperglycemia, focusing on mesangial cells. Normal human mesangial cells (NHMCs) were cultured in the medium containing normal (5 mM) or high (25 mM) concentrations of D -glucose. Reactive oxygen species (ROS) production, the activation of nuclear transcription factors such as nuclear factor kappa B (NF,B) and activator protein-1 (AP-1), and the expression/production of transforming growth factor-beta 1 (TGF,1) and monocyte chemoattractant protein-1 (MCP-1) were evaluated in the presence or absence of ASX. High glucose (HG) exposure induced significant ROS production in mitochondria of NHMCs, which resulted in the activation of transcription factors, and subsequent expression/production of cytokines that plays an important role in the mesangial expansion, an important event in the pathogenesis of diabetic nephropathy. ASX significantly suppressed HG-induced ROS production, the activation of transcription factors, and cytokine expression/production by NHMCs. In addition, ASX accumulated in the mitochondria of NHMCs and reduced the production of ROS-modified proteins in mitochondria. ASX may prevent the progression of diabetic nephropathy mainly through ROS scavenging effect in mitochondria of mesangial cells and thus is expected to be very useful for the prevention of diabetic nephropathy. J. Cell. Biochem. 103: 1925,1937, 2007. © 2007 Wiley-Liss, Inc. [source] High glucose levels upregulate upstream stimulatory factor 2 gene transcription in mesangial cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2008Lihua Shi Abstract Previously, we demonstrated that upstream stimulatory factor 2 (USF2) mediates high glucose-induced thrombospondin1 (TSP1) gene expression and TGF-, activity in glomerular mesangial cells and plays a role in diabetic renal complications. In the present studies, we further determined the molecular mechanisms by which high glucose levels regulate USF2 gene expression. In primary rat mesangial cells, we found that glucose treatment time and dose-dependently up-regulated USF2 expression (mRNA and protein). By using cycloheximide to block the de novo protein synthesis, similar rate of USF2 degradation was found under either normal glucose or high glucose conditions. USF2 mRNA stability was not altered by high glucose treatment. Furthermore, high glucose treatment stimulated USF2 gene promoter activity. By using the luciferase-promoter deletion assay, site-directed mutagenesis, and transactivation assay, we identified a glucose-responsive element in the USF2 gene promoter (,1,740 to ,1,620, relative to the transcription start site) and demonstrated that glucose-induced USF2 expression is mediated through a cAMP-response element-binding protein (CREB)-dependent transactivation of the USF2 promoter. Furthermore, siRNA-mediated CREB knock down abolished glucose-induced USF2 expression. Taken together, these data indicate that high glucose levels up-regulate USF2 gene transcription in mesangial cells through CREB-dependent transactivation of the USF2 promoter. J. Cell. Biochem. 103: 1952,1961, 2007. © 2007 Wiley-Liss, Inc. [source] p38, MAP kinase protects rat mesangial cells from TNF-,-induced apoptosisJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 4 2001Yan-Lin Guo Abstract p38 MAP kinases (p38) and c-Jun N-terminal protein kinases (JNK) have been associated with TNF-,-induced apoptosis. However, recent studies indicate that an early but brief activation of JNK and/or p38 may actually protect some cells from TNF-,-induced apoptosis. Whether the activation of JNK and p38 provides a pro- or anti-apoptotic signal for TNF-, has been controversial. In this study, we investigated the role of p38 in the regulation of TNF-, cytotoxicity in rat mesangial cells. Treatment of the cells with TNF-, alone had little effect on their viability, but they became very sensitive to apoptosis when treated with TNF-, in the presence of the p38 inhibitor SB 203580. These results suggested that the p38 pathway is critical for mesangial cells to survive the toxic effect of TNF-,. Using adenovirus-mediated gene transfer technique, we further demonstrated that p38,, but not p38,, is essential to protect the cells from TNF-, toxicity. It has been speculated that there is a synergetic interaction between the p38 and the nuclear factor-,B (NF-,B) pathways in protecting certain cells from apoptosis. However, expression of neither p38, nor its dominant negative mutant in mesangial cells interfered with TNF-,-induced translocation of NF-,B, the initial step of NF-,B activation. While it is unclear whether p38, regulates NF-,B transcription activity at other steps, it is apparent that p38, does not affect TNF-,-induced NF-,B activation at the stage of nuclear translocation. J. Cell. Biochem. 82: 556,565, 2001. © 2001 Wiley-Liss, Inc. [source] Relationship between levels of urinary type IV collagen and renal injuries in patients with IgA nephropathyJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 1 2004Hiroaki Io Abstract Because type IV collagen is synthesized by podocytes and mesangial cells, we investigated the relationship between levels of urinary type IV collagen (uIV) and renal injuries in patients with IgA nephropathy. uIV was measured by a highly sensitive one-step sandwich enzyme immunoassay prior to renal biopsy. Patients with IgA nephropathy were classified into four grades (grade 1 = good prognosis, grade 2 = relatively good prognosis, grade 3 = relatively poor prognosis, and grade 4 = poor prognosis) by the prognostic criteria of the Ministry of Health, Labor, and Welfare of Japan. Levels of uIV in grade 4 were significantly higher than those in grades 1,3. These levels tended to increase gradually due to progression of renal injuries. The grades were further divided into two groups: group I (good or relatively good prognoses) and group II (relatively poor or poor prognoses). Patients with proteinuria of <1.0 g/day were defined as groups Ip and IIp. The levels of uIV in group II were significantly higher than those in group I, and those in group IIp were significantly higher than those in group Ip. It appears that the level of uIV can be a useful marker for detection of renal injuries in IgA nephropathy. J. Clin. Lab. Anal. 18:14,18, 2004. © 2004 Wiley-Liss, Inc. [source] Decorin transfection in human mesangial cells downregulates genes playing a role in the progression of fibrosisJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 4 2002Antonia Costacurta Abstract The proteoglycan decorin inhibits TGF-,; therefore, it could antagonize progression of fibrotic diseases associated with activation of TGF-,1. The effect of decorin transfection in human mesangial cells (HMCs) on the expression of genes related to kidney fibrosis was investigated. HMCs, isolated from glomeruli of healthy portions of human kidneys removed due to carcinoma, were histochemically typed. Decorin cDNA cloned in a eukaryotic expression vector was transfected into HMCs. Gene expression of fibrogenetic cytokines and fibrotic proteins TGF-,1, PDGF-,, ,1 collagen type IV, ,1 collagen type I, fibronectin, and tenascin was analyzed, by reverse transcription polymerase chain reaction (RT-PCR), 24 hr after transfection. Immunoblotting analysis of protein extracts using anti-decorin IgG, revealed a positive signal of about 52 MDa, corresponding to the molecular weight of decorin, in cultures transfected with the decorin gene. Decorin mRNA increased about 12 times in cultures transfected with the construct pCR3.1-Deco. Cells with increased decorin synthesis showed a 61% decrease of TGF-,1 mRNA, a 71% reduction of ,1 collagen type IV mRNA, and a 29% reduction of fibronectin mRNA. This study is the first to investigate decorin transfection into human mesangial cells, and supports the use of the decorin gene to control the progression of glomerular and interstitial fibrosis in kidney diseases. © 2002 Wiley-Liss, Inc. [source] Cellular activation by plasmid DNA in various macrophages in primary cultureJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 10 2008Hiroyuki Yoshida Abstract Macrophages are an important group of cells responsible for the inflammatory response to unmethylated CpG dinucleotide (CpG motif) in plasmid DNA (pDNA) via Toll-like receptor 9 (TLR9). This finding is primarily based on in vitro studies. Previous in vivo studies also have suggested that tissue macrophages are involved in inflammatory cytokine release in the circulation following intravenous administration of pDNA to mice. However, the relationship between the in vitro and in vivo studies has not been sufficiently clarified. To gain insight into which types of cells are responsible for the production of cytokines upon interaction with pDNA, peritoneal macrophages, splenic macrophages, hepatic nonparenchymal cells (NPCs) including Kupffer cells and mesangial cells were isolated from mice. All types of primary cultured cells, except for mesangial cells, express TLR9 at varying levels. Splenic macrophages and hepatic NPCs were activated to produce tumor necrosis factor-, (TNF-,) by naked pDNA, whereas peritoneal macrophages and mesangial cells were not. pDNA complexed with N -[1-(2,3-dioleyloxy)propyl]- N,N,N -trimethyl-ammonium chloride/cholesterol liposome induced TNF-, in the splenic macrophages but not in the other cell types. These results indicate that splenic macrophages and hepatic NPCs are closely involved in TNF-, production in response to pDNA. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:4575,4585, 2008 [source] Inhibitory Effects of Ethanol on Rat Mesangial Cell Proliferation via Protein Kinase C PathwayALCOHOLISM, Issue 3 2002Kayoko Segawa A large body of evidence has shown that ethanol inhibits the cell growth and cell proliferation in a variety of cell types. However, it has not been studied whether ethanol inhibits the proliferation of mesangial cells (MC) in the kidney. We examined the effects of ethanol on cell proliferation in cultured rat MC. Treatment with ethanol (10,200 mM) for 48 hr inhibited [3H]thymidine incorporation into MC in a concentration-dependent manner. The same concentrations of ethanol also inhibited the increase in cell number of MC. GF109203X and chelerythrine chloride, inhibitors for protein kinase C, eliminated the inhibitory effects of ethanol; and protein kinase C activator, PMA, mimicked the effects of ethanol. In contrast, neither the protein kinase A inhibitor H-89 nor the protein kinase G inhibitor KT5823 had any effect. These findings suggest that ethanol has inhibitory effects on the proliferation of MC, probably via activation of the protein kinase C pathway. [source] Statins and progressive renal diseaseMEDICINAL RESEARCH REVIEWS, Issue 1 2002Michele Buemi Abstract Thanks to the administration of hypocholesterolemic drugs, important advances have been made in the treatment of patients with progressive renal disease. In vitro and in vivo findings demonstrate that statins, the inhibitors of HMG-CoA reductase, can provide protection against kidney diseases characterized by inflammation and/or enhanced proliferation of epithelial cells occurring in rapidly progressive glomerulonephritis, or by increased proliferation of mesangial cells occurring in IgA nephropathy. Many of the beneficial effects obtained occur independent of reduced cholesterol levels because statins can directly inhibit the proliferation of different cell types (e.g., mesangial, renal tubular, and vascular smooth muscle cells), and can also modulate the inflammatory response, thus inhibiting macrophage recruitment and activation, as well as fibrosis. The mechanisms underlying the action of statins are not yet well understood, although recent data in the literature indicate that they can directly affect the proliferation/apoptosis balance, the down-regulation of inflammatory chemokines, and the cytogenic messages mediated by the GTPases Ras superfamily. Therefore, as well as reducing serum lipids, statins and other lipid-lowering agents may directly influence intracellular signaling pathways involved in the prenylation of low molecular weight proteins that play a crucial role in cell signal transduction and cell activation. Statins appear to have important potential in the treatment of progressive renal disease, although further studies are required to confirm this in humans. © 2001 John Wiley & Sons, Inc. Med Res Rev, 22, No. 1, 76,84, 2002 [source] Roxithromycin inhibits transforming growth factor-, production by cultured human mesangial cellsNEPHROLOGY, Issue 6 2006HIDEAKI YAMABE SUMMARY: Background: Transforming growth factor-, (TGF-,) plays an important role in progression of renal injury. However, few materials which inhibit TGF-, have been known. Roxithromycin (ROX), macrolide antibiotics, is known to have anti-inflammatory, immunomodulatory and tissue reparative effects besides its bacteriostatic activity, although the exact mechanism of its anti-inflammatory and immunomodulatory effects was not defined. We examined the effect of ROX on production of TGF-, and type IV collagen by cultured human mesangial cells (HMC). Methods: Human mesangial cells were incubated with several concentrations of ROX and TGF-, and type IV collagen levels in the culture supernatants were measured by enzyme-linked immunoassay. Amount of TGF-, mRNA was also quantified by using a colourimetric mRNA quantification kit and semiquantitative reverse transcriptase polymerase chain reaction. We also examined the effect of ROX on tyrosine kinase, MAP kinase and NF-,B stimulated by thrombin. Results: Roxithromycin (0.1,10.0 µg/mL) inhibited TGF-, production by HMC in a dose- and time-dependent manner without inducing cell injury. ROX (10.0 µg/mL) also inhibited mRNA expression of TGF-, in HMC. Thrombin (5 U/mL) stimulated TGF-, production by HMC and ROX significantly inhibited the stimulating effect of thrombin on TGF-, production. ROX also inhibited the increment of type IV collagen production stimulated by thrombin. ROX (10.0 µg/mL) suppressed the thrombin-induced NF-,B activation, although ROX did not inhibit the activation of tyrosine kinase and MAP kinase by thrombin. Conclusion: Roxithromycin has an inhibitory effect on TGF-, production by HMC possibly via inhibition of NF-,B. ROX may be a potential agent for the treatment of glomerulosclerosis. [source] IgA nephropathy and mesangial cell proliferation: shared global gene expression profilesNEPHROLOGY, Issue 2002Hideto SAKAI SUMMARY: It is well established that mesangial cell proliferation plays a major role in glomerular injury and progressive renal injury. the expression of a number of different genes has been reported in proliferative mesangial cells in culture. However, the relevance of these genes to renal injury in general and IgA nephropathy (IgAN) remains to be established. Assessment of gene activity on a global genome-wide scale is a fundamental and newly developed molecular strategy to expand the scope of clinical investigation from a single gene to studying all genes at once in a systematic pattern. Capitalizing on the recently developed methodology of high cDNA array hybridization, the simultaneous expression of thousands of genes in primary human proliferating mesangial cells was monitored and compared with renal tissue of IgAN. Complex [,- 33P]-labelled cDNA targets were prepared from cultured mesangial cells, remnant tissue from five IgAN renal biopsies and four nephrectomies (controls). Each target was hybridized to a high-density array of 18 326 paired target genes. the radioactive hybridization signals were analysed by phosphorimager. Approximately 8212±530 different gene transcripts were detected per target. Close to 5% (386±90 genes) were full-length mRNA human transcripts (HT) and the remainder were expressed sequence tags (EST). Using a relational database, electronic subtraction was performed and matching was carried out to allow identification of 203 HT with shared expression in proliferative mesangial cells and IgAN renal biopsies. In addition hierarchical clustering analysis was performed on the HT of IgAN and controls to establish differential expression profiles of mesangial HT in IgAN and controls. Collectively the presented data constitutes a preliminary renal bioinformatics database of the transcriptional profiles in IgAN. More importantly, the information may help to speed up the discovery of genes underlying human IgAN. [source] Genomic repertoire of human mesangial cells: comprehensive analysis of gene expression by cDNA array hybridizationNEPHROLOGY, Issue 4 2000Naohiro Yano SUMMARY: Knowing when and where a gene is expressed in a cell often provides a strong clue as to its physiological role. It is estimated the human genome contains 80 000,100 000 genes. Assessment of gene activity on a global genome-wide scale is a fundamental and newly developed experimental strategy to expand the scope of biological investigation from a single gene to studying all genes at once in a systematic way. Capitalizing on the recently developed methodology of cDNA array hybridization, we monitored the simultaneous expression of thousands of genes in primary human mesangial cells. Complex ,- 33P-labelled cDNA probes were prepared from cultured mesangial cells. The probe was hybridized to a high-density array of 18 326 paired target genes. The radioactive hybridization signals were analysed by phosphorimager. Bioinformatics from public genomic databases was utilized to assign a chromosomal location of each expressed transcript. Approximately 7460 different gene transcripts were detected in mesangial cells. Close to 13% (957 genes) were full-length mRNA human transcripts (HTs), the remainder 6503 being expressed sequence tags (ESTs). Using special imaging computer software, the transcriptional level of the 957 HTs was compared with the expression of the ribosomal protein S28 (housekeeping gene). The HTs were also classified by function of the gene product and listed with information on their chromosomal loci. To allow comparison between clinical and experimental studies of gene expression, the detected human gene transcripts were cross-referenced to orthologous mouse genes. Thus, the presented data constitute a quantitative preliminary blueprint of the transcriptional map of the human mesangial cell. The information may serve as a resource for speeding up the discovery of genes underlying human glomerular diseases. The complete listing of the full-length expressed genes is available upon request via E-mail: (Abdalla_Rifai@Brown.edu). [source] Role of translational research advancing the understanding of the pathogenesis of light chain-mediated glomerulopathiesPATHOLOGY INTERNATIONAL, Issue 7 2007Jiamin Teng Glomerulopathic light chains engage in pathological interactions with mesangial cells resulting in alterations in glomerular homeostasis. The crucial pathological events are centered in the mesangium and, therefore, research dealing with pathogenesis of these disorders is focused on this glomerular compartment. Particular physicochemical characteristics of these light chains are responsible for their ability to alter mesangial milieu leading to glomerular damage. An in vitro model has been used to dissect the processes involved. This model has been instrumental in providing a solid platform from which to observe in a dynamic fashion how mesangial cells handle pathogenic light chains and the sequential steps that are involved in the progressive glomerular damage. Key steps amenable to possible modulation have been defined and should provide a solid platform to design and test therapeutic interventions. In the past significant difficulties have been encountered in the development of animal models of light chain-induced glomerular damage. However, in the last few years a new generation of animal models has emerged to address whether what has been documented in vitro retains significance in vivo. Preliminary observations appear to substantiate this. [source] Mangiferin prevents diabetic nephropathy progression in streptozotocin-induced diabetic ratsPHYTOTHERAPY RESEARCH, Issue 6 2010Xuan Li Abstract Diabetic nephropathy is one of the most severe diabetic microangiopathies and accounting for approximately one-third of all cases of end-stage renal disease. In the present study, we investigated the effect of mangiferin, a polyphenol from Anemarrhena asphodeloides Bge. or Mangifera indica L., on diabetic nephropathy and the possible mechanisms by using a developed diabetic nephropathy rat model and cultured rat mesangial cells. Serum-advanced glycation end-products level, malonaldehyde level, sorbitol concentration of red blood cell, 24,h albuminuria excretion were significantly decreased, whereas activity of serum superoxide dismutase and glutathione peroxidase and creatinine clearance rate were increased by mangiferin. Blood glucose level remained unaffected. Mangiferin significantly inhibited glomerular extracellular matrix expansion and accumulation and transforming growth factor-beta 1 overexpression in glomeruli of diabetic nephropathy rats. Moreover, mangiferin was observed to inhibit proliferation of mesangial cells induced by high glucose and the overexpression of collagen type IV of mesangial cells induced by advanced glycation end products. In summary, mangiferin could significantly prevent progression of diabetic nephropathy and improve renal function. Copyright © 2009 John Wiley & Sons, Ltd. [source] Characterization of gelatin nanofibers electrospun using ethanol/formic acid/water as a solventPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 2 2009Hsin-Chieh Chen Abstract Gelatin nanofibers were prepared via electrospinning using aqueous solutions of formic acid and ethanol as the solvent instead of cytotoxic solvents. The resulting mat was further crosslinked with glutaraldehyde (GTA). The influence of the storing time on the viscosity and gel point of the solution was investigated. The gelatin nanofibers were examined using a field emission scanning electron microscope (FESEM) for the fiber size and morphology. The lowest diameter of gelatin fiber (85,nm, without beads) was achieved when the gelatin concentration was 20,wt% and electrospinning was conducted with a voltage of 20,kV over a distance of 10,cm at ambient temperature. The results from differential scanning calorimetry (DSC) showed that the softening temperature of gelatin nanofibers crosslinked with GTA was elevated. In addition, GTA-crosslinked gelatin nanofibers exhibited cell compatibility for mouse mesangial cells (CRL 1927). Copyright © 2008 John Wiley & Sons, Ltd. [source] Lessons from studies on focal segmental glomerulosclerosis: an important role for parietal epithelial cells?THE JOURNAL OF PATHOLOGY, Issue 3 2006B Smeets Abstract Glomerular diseases are caused by multiple mechanisms. Progressive glomerular injury is characterized by the development of segmental or global glomerulosclerosis independent of the nature of the underlying renal disease. Most studies on glomerular disease focus on the constituents of the filtration barrier (podocytes, glomerular basement membrane (GBM), endothelial cells) or the mesangial cells. Little attention is given to the epithelial cells lining Bowman's capsule, the so called parietal epithelial cells (PECs). This ,lack of attention' is partly explained by the presumed ,passive' function of PECs, which are large, flattened cells that cover Bowman's capsule in a single cell layer and form a barrier between the ultrafiltrate and the periglomerular interstitium, in normal glomerular physiology. A more important reason has been the lack of an established primary role for the parietal epithelium in glomerular diseases. However, in recent years, several studies have demonstrated that PECs are involved in extracapillary proliferation. In addition, PECs can become highly active, proliferating cells, expressing many growth factors, chemokines, cytokines, and their receptors. It was recently demonstrated that PECs also play a part in the development of focal segmental glomerulosclerosis (FSGS). This review summarises current knowledge of the PEC, with emphasis on the role of PECs in the development of FSGS. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Anti-DNA antibody induction of protein kinase C phosphorylation and fibronectin synthesis in human and murine lupus and the effect of mycophenolic acidARTHRITIS & RHEUMATISM, Issue 7 2009Susan Yung Objective To examine fibronectin (FN) expression in human lupus nephritis and the effect of anti-DNA antibodies on transforming growth factor ,1 (TGF,1) and FN synthesis in cultured human mesangial cells. The effects of mycophenolic acid (MPA) on this pathway, and the effects of mycophenolate mofetil (MMF) treatment in (NZB × NZW)F1/J mice were also studied. Methods Immunohistochemical analyses of renal biopsy samples from patients with active diffuse proliferative lupus nephritis were performed. Cultured human mesangial cells were incubated with human polyclonal anti-DNA antibodies, with or without MPA. (NZB × NZW)F1/J mice with active nephritis were randomized to receive either MMF (100 mg/kg/day) or vehicle treatment for 12 weeks. Results Glomerular FN expression was increased in patients with lupus nephritis, and it colocalized with IgG deposition. Anti-DNA antibodies induced protein kinase C, (PKC,), PKC,I, and PKC,II activation, increased levels of bioactive TGF,1, and increased FN synthesis in human mesangial cells (P < 0.001 for each comparison versus control conditions). Pretreatment of anti-DNA antibodies with exogenous DNA reduced their cellular binding and abrogated their induction of TGF,1 and FN synthesis. Inhibition of PKC activation in human mesangial cells prior to anti-DNA antibody stimulation had no effect on cell proliferation, but resulted in significantly reduced antibody-mediated TGF,1 secretion and FN synthesis. MPA treatment down-regulated PKC,, PKC,I, and PKC,II phosphorylation, reduced levels of TGF,1 bioactivation, and decreased FN synthesis and deposition into the extracellular matrix. MMF treatment in (NZB × NZW)F1/J mice resulted in a reduction in glomerular IgG deposition, PKC activation, and FN expression, as well as an amelioration of proteinuria. Conclusion Human polyclonal anti-DNA antibodies induce TGF,1 and FN synthesis in human mesangial cells through PKC activation, which is inhibited by MPA. [source] Urinary lipocalin-2 is associated with renal disease activity in human lupus nephritisARTHRITIS & RHEUMATISM, Issue 6 2007Milena Pitashny Objective Pathogenic monoclonal anti,double-stranded DNA (anti-dsDNA) antibodies up-regulate the expression of lipocalin-2 in glomerular mesangial cells. This study was undertaken to investigate whether polyclonal anti-dsDNA antibodies promote the local secretion of lipocalin-2 in the kidneys of patients with systemic lupus erythematosus (SLE), and whether urinary lipocalin-2 represents a marker of kidney involvement in SLE. Methods Hispanic, African American, and white patients with SLE and normal healthy control subjects from affiliated hospitals of the Albert Einstein College of Medicine were recruited for this cross-sectional study. Patients were classified based on the presence of active renal disease according to the SLE Disease Activity Index (SLEDAI). Correlations of clinical and laboratory data with urinary and serum levels of lipocalin-2 were assessed. Results Among SLE patients, urinary lipocalin-2 levels were significantly higher in those with lupus nephritis (LN) (median 17.1 ng/mg creatinine, interquartile range [IQR] 10.3,45.4; n = 32) than in those without LN (median 11.2 ng/mg creatinine, IQR 3.1,20.3; n = 38) (P = 0.023). Compared with the values in normal controls (median 4 ng/ml, IQR 0,11.1; n = 14), urinary levels of lipocalin-2 in SLE patients were significantly higher (non-normalized median 19.3 ng/ml, IQR 8,34.2) (P = 0.004). The presence of lipocalin-2 in the urine of patients with LN correlated significantly with the renal SLEDAI score (r = 0.452, P = 0.009), but not with extrarenal disease activity. Conclusion The high prevalence of LN in SLE patients and the prognostic significance of kidney disease support the need for identifying early biomarkers to assess the risk of nephritis development and for following up patients with established disease. These findings indicate that urinary lipocalin-2 is a potential marker of the presence and severity of renal involvement in adult patients with SLE. [source] Nephritogenic Anti-DNA antibodies regulate gene expression in MRL/lpr mouse glomerular mesangial cellsARTHRITIS & RHEUMATISM, Issue 7 2006Xiaoping Qing Objective Lupus-associated IgG anti,double-stranded DNA antibodies are thought to be pathogenic in the kidney due to cross-reaction with glomerular antigens, leading subsequently to immune complex formation in situ and complement activation. We undertook this study to determine if pathogenic anti-DNA antibodies may also contribute to renal damage by directly influencing mesangial gene expression. Methods Complementary DNA microarray gene profiling was performed in primary mesangial cells (derived from lupus-prone MRL/lpr mice) treated with pathogenic, noncomplexed anti-DNA antibodies. Significant gene up-regulation induced by anti-DNA antibodies as determined by microarray analysis was further investigated by real-time polymerase chain reaction and methods to detect the relevant proteins. Induction of proinflammatory genes by pathogenic antibodies was confirmed by comparing gene expression in glomeruli of old versus young MRL/lpr mice, and by antibody injection in vivo. Results Pathogenic, but not nonpathogenic, antibodies significantly induced a number of transcripts, including CXCL1/KC, LCN2, iNOS, CX3CL1/fractalkine, SERPINA3G, and I,B, ("marker genes"). Blocking of Fc, receptors or using Fc, chain,knockout mesangial cells had no effect on the gene regulation effect of the pathogenic antibody R4A, indicating a non,Fc-dependent mechanism. The glomerular expression of these marker genes increased over time with the development of glomerular antibody deposition and active nephritis in MRL/lpr mice. Moreover, injection of R4A into SCID mice in vivo significantly up-regulated glomerular marker gene expression. Conclusion These findings indicate that the renal pathogenicity of anti-DNA antibodies may be attributed in part to their ability to directly modulate gene expression in kidney mesangial cells through both Fc-dependent and non,Fc-dependent mechanisms. [source] Heterologous desensitization of the sphingosine-1-phosphate receptors by purinoceptor activation in renal mesangial cellsBRITISH JOURNAL OF PHARMACOLOGY, Issue 5 2004Cuiyan Xin Sphingosine-1-phosphate (S1P) is considered a potent mitogen for mesangial cells and activates the classical mitogen-activated protein kinase (MAPK) cascade via S1P receptors. In this study, we show that S1P signalling is rapidly desensitized upon S1P receptor activation. A complete loss of S1P sensitivity occurs after 10 min of S1P pretreatment and remains for at least 8 h. A similar desensitization is also seen with the S1P mimetic FTY720-phosphate, but not with the nonphosphorylated FTY720, nor with sphingosine or ceramide. Prestimulating the cells with extracellular ATP or UTP, which bind to and activate P2Y receptors on mesangial cells, a similar rapid desensitization of the S1P receptor occurs, suggesting a heterologous desensitization of S1P receptors by P2Y receptor activation. Furthermore, adenosine binding to P1 receptors triggers a similar desensitization. In contrast, two other growth factors, PDGF-BB and TGF,2, have no significant effect on S1P-induced MAPK activation. S1P also triggers increased inositol trisphosphate (IP3) formation, which is completely abolished by S1P pretreatment but only partially by ATP pretreatment, suggesting that IP3 formation and MAPK activation stimulated by S1P involve different receptor subtypes. Increasing intracellular cAMP levels by forskolin pretreatment has a similar effect on desensitization as adenosine. Moreover, a selective A3 adenosine receptor agonist, which couples to phospholipase C and increases IP3 formation, exerted a similar effect. Pretreatment of cells with various protein kinase C (PKC) inhibitors prior to ATP prestimulation and subsequent S1P stimulation leads to a differential reversal of the ATP effect. Whereas the broad-spectrum protein kinase inhibitor staurosporine potently reverses the effect, the PKC- , inhibitor CGP41251, the PKC- , inhibitor rottlerin and calphostin C show only a partial reversal at maximal concentrations. Suramin, which is reported as a selective S1P3 receptor antagonist compared to the other S1P receptor subtypes, has no effect on the S1P-induced MAPK activation, thus excluding the involvement of S1P3 in this response. In summary, these data document a rapid homologous and also heterologous desensitization of S1P signalling in mesangial cells, which is mechanistically triggered by PKC activation and eventually another staurosporine-sensitive protein kinase, as well as by increased cAMP formation. British Journal of Pharmacology (2004) 143, 581,589. doi:10.1038/sj.bjp.0705980 [source] Dilazep, a nucleoside transporter inhibitor, modulates cell cycle progression and DNA synthesis in rat mesangial cells in vitroCELL PROLIFERATION, Issue 1 2000T. Sakumura The direct effects of the nucleoside transporter inhibitor dilazep on the cell cycle of mesangial cells have not before been investigated. The purpose of this study was to elucidate whether dilazep can inhibit the proliferation of mesangial cells and how it interferes with the cell cycle of these cells. DNA histograms were used and BrdUrd uptake rate was measured by flow cytometry. There was no significant difference in the cell numbers among the untreated group and the 10,5M, 10,6M or 10,7M dilazep-treated groups at 24 h of incubation. However, at 48 and 72 h, the cell numbers in the dilazep-treated groups were significantly lower compared with that of the untreated group (P0.005). The DNA histograms of cultured rat mesangial cells at 12, 24, and 48 h of incubation with 10,5 M dilazep showed that the ratio of the S phase population in the dilazep-treated group decreased by 2.2% at 12 h, by 9.6% at 24 h, and by 18.9% at 48 h compared with the untreated group. The ratio of the G0/G1 phase population in the dilazep-treated group significantly increased: 6.8% at 12h (P 0.05), 13.9% at 24 h (P 0.001), and 76.5% at 48 h (P 0.001) compared with the untreated group. A flow cytometric measurement of bivariate DNA/BrdUrd distribution demonstrated that the DNA synthesis rate in the S phase decreased after 6 h (P 0.005) and 12 h (P 0.05) of incubation compared with the untreated group. These results suggest that dilazep inhibits the proliferation of cultured rat mesangial cells by suppressing the G1/S transition by prolonging G2/M and through decreasing the DNA synthesis rate [source] DIFFERENTIAL REGULATION OF ANGIOTENSIN II RECEPTORS DURING RENAL INJURY AND COMPENSATORY HYPERTROPHY IN THE RATCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 4 2005Emma Joly SUMMARY 1.,The renin-angiotensin system may be involved in the compensatory adaptations occurring after the reduction of renal mass and during the consecutive changes leading to chronic renal failure. We therefore investigated the regulation of angiotensin II receptors in two models of renal hypertrophy in the rat: hypertrophy following uninephrectomy (UNx) or subtotal nephrectomy (STNx). The level of angiotensin type 1 (AT1A -R and AT1B -R) and type 2 (AT2 -R) receptor mRNA was quantified by competitive reverse transcription-polymerase chain reaction (RT-PCR) in specific renal zones and the intrarenal distribution of angiotensin II receptors was analysed by immunohistochemistry. 2.,In the UNx rats, AT1 -R mRNA expression was not modified in the cortex or in the inner stripe of the outer medulla of the residual kidney at any time after the surgery (1, 4 and 12 weeks). In contrast, AT1 -R mRNA expression was significantly reduced in these zones in STNx rats (,33% and ,40%, respectively). This downregulation was organ-specific, as AT1 -R mRNA levels were not modified in the liver. The proportions of AT1 -R subtype (AT1A and AT1B) mRNA were unchanged by UNx or STNx. Very low levels of AT2 -R mRNA were found in the cortex of all groups. Immunostaining revealed a similar localization of AT1 -R in mesangial cells, proximal tubule, basolateral membrane of thick ascending limb, in both models of hypertrophy. AT1 -R labelling was also detected in the apical membrane of intercalated cells of cortical collecting ducts. 3.,This differential mRNA expression of angiotensin II receptors during compensatory hypertrophy and renal injury suggests that the development of renal hypertrophy is independent of AT1 -R and AT2 -R gene expression levels. [source] Renal And Cardiovascular Actions Of 20-Hydroxyeicosatetraenoic Acid And Epoxyeicosatrienoic AcidsCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 11 2000Richard J Roman SUMMARY 1. Arachidonic acid (AA) is metabolized by cytochrome P450 (CYP)-dependent pathways to epoxyeicosatrienoic acids (EET) and 20-hydroxyeicosatetraenoic acid (20-HETE) in the kidney and the peripheral vasculature. 2. The present short review summarizes the renal and cardiovascular actions of these important mediators. 3. Epoxyeicosatrienoic acids are vasodilators produced by the endothelium that hyperpolarize vascular smooth muscle (VSM) cells by opening Ca2+ -activated K+ (KCa) channels. 20-Hydroxyeicosatetraenoic acid is a vasoconstrictor that inhibits the opening of KCa channels in VSM cells. Cytochrome P450 4A inhibitors block the myogenic response of small arterioles to elevations in transmural pressure and autoregulation of renal and cerebral blood flow in vivo. Cytochrome P450 4A blockers also attenuate the vasoconstrictor response to elevations in tissue PO2, suggesting that this system may serve as a vascular oxygen sensor. Nitric oxide and carbon monoxide inhibit the formation of 20-HETE and a fall in 20-HETE levels contributes to the activation of KCa channels in VSM cells and the vasodilator response to these gaseous mediators. 20-Hydroxyeicosatetraenoic acid also mediates the inhibitory actions of peptide hormones on sodium transport in the kidney and the mitogenic effects of growth factors in VSM and mesangial cells. A deficiency in the renal production of 20-HETE is associated with the development of hypertension in Dahl salt-sensitive rats. 4. In summary, the available evidence indicates that CYP metabolites of AA play a central role in the regulation of renal, pulmonary and vascular function and that abnormalities in this system may contribute to the pathogenesis of cardiovascular diseases. [source] | ||||||||||||||||||||||||||||