Persistent inflammation plays a pivotal role in the initiation and progression of renal fibrosis. Activation of the pattern recognition receptor retinoic acid-inducible gene-I (RIG-I) is implicated in the initiation of inflammation. This study aimed to investigate the upstream mechanisms that regulates the activation of RIG-I and its downstream signaling pathway. Eight-week-old male C57BL/6 mice were used to establish unilateral ureteral obstruction (UUO)-induced renal fibrosis model, and the renal tissue samples were collected 14 days later for analysis. Transforming growth factor-β (TGF-β)-treated mouse renal tubular epithelial cells were used in in vitro studies. The results demonstrated that, compared to the control group, UUO kidney exhibited significant fibrosis, which was accompanied by the increases of RIG-I, p-NF-κB p65 and inflammatory cytokines, such as TNF-α and IL-1β. Additionally, the protein level of the E3 ubiquitin ligase RNF125 was significantly downregulated and predominantly localized in the renal tubular epithelial cells. Similarly, the treatment of tubular cells with TGF-β induced the increases in RIG-I, p-NF-κB p65 and inflammatory cytokines while decreasing RNF125. Co-immunoprecipitation (Co-IP) assays confirmed that RNF125 was able to interact with RIG-I. Overexpression of RNF125 promoted the ubiquitination of RIG-I, and accelerated its degradation via the ubiquitin-proteasome pathway. Overexpression of RNF125 in UUO kidneys and in vitro tubular cells effectively mitigated the inflammatory response and renal fibrosis. In summary, our results demonstrated that the decrease in RNF125 under pathological conditions led to reduction in RIG-I ubiquitination and degradation, activation of the downstream NF-κB signaling pathway and increase in inflammatory cytokine production, which promoted the progression of renal fibrosis.
Animals ; Fibrosis ; Male ; Ubiquitination ; Mice ; Mice, Inbred C57BL ; DEAD Box Protein 58 ; Ubiquitin-Protein Ligases/physiology* ; Inflammation/metabolism* ; Ureteral Obstruction/complications* ; Kidney/pathology* ; Signal Transduction ; Transforming Growth Factor beta/pharmacology*

OBJECTIVES: To explore the mechanism of transforming growth factor-β1 (TGF-β1) induce renal fibrosis. METHODS: Renal fibroblast NRK-49F cells treated with and without TGF-β1 were subjected to RNA-seq analysis. DESeq2 was used for analysis. Differentially expressed genes were screened with the criteria of false discovery rate<0.05 and l o g 2 F C >1. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed for differentially expressed genes. Genes encoding transcription factors were further screened for differential expression genes. Then, the expression of these genes during renal fibrosis was verified using unilateral ureteral obstruction (UUO)-induced mouse renal fibrosis model and a public gene expression dataset (GSE104954). RESULTS: After TGF-β1 treatment for 6, 12 and 24 h, 552, 1209 and 1028 differentially expressed genes were identified, respectively. GO analysis indicated that these genes were significantly enriched in development, cell death, and cell migration. KEGG pathway analysis showed that in the early stage of TGF-β1 induction (TGF-β1 treatment for 6 h), the changes in Hippo, TGF-β and Wnt signaling pathways were observed, while in the late stage of TGF-β1 induction (TGF-β1 treatment for 24 h), the changes of extracellular matrix-receptor interaction, focal adhesion and adherens junction were mainly enriched. Among the 291 up-regulated differentially expressed genes treated with TGF-β1 for 6 h, 13 genes (Snai1, Irf8, Bhlhe40, Junb, Arid5a, Vdr, Lef1, Ahr, Foxo1, Myc, Tcf7, Foxc2, Glis1) encoded transcription factors. Validation in a cell model showed that TGF-β1 induced expression of 9 transcription factors (encoded by Snai1, Irf8, Bhlhe40, Junb, Arid5a, Vdr, Lef1, Myc, Tcf7), while the expression levels of the other 4 genes did not significantly change after TGF-β1 treatment. Validation results in UUO-induced mouse renal fibrosis model showed that Snai1, Irf8, Bhlhe40, Junb, Arid5a, Myc and Tcf7 were up-regulated after UUO, Vdr was down-regulated and there was no significant change in Lef1. Validation based on the GSE104954 dataset showed that IRF8 was significantly overexpressed in the renal tubulointerstitium of patients with diabetic nephropathy or IgA nephropathy, MYC was highly expressed in diabetic nephropathy, and the expressions of the other 7 genes were not significantly different compared with the control group. CONCLUSIONS TGF-β1 induces differentially expressed genes in renal fibroblasts, among which Irf8 and Myc were identified as potential targets of chronic kidney disease and renal fibrosis.
Mice ; Animals ; Humans ; Transforming Growth Factor beta1/metabolism* ; Diabetic Nephropathies/pathology* ; Transcriptome ; Signal Transduction ; Kidney ; Ureteral Obstruction/pathology* ; Fibrosis ; Interferon Regulatory Factors ; Transforming Growth Factor beta/metabolism* ; DNA-Binding Proteins/metabolism* ; Transcription Factors/metabolism*

Diabetic kidney disease (DKD) is the most common complication of diabetes mellitus (DM). Qianjin Wenwu decoction (QWD), a well-known traditional Korean medicine, has been used for the treatment of DKD, with satisfactory therapeutic effects. This study was designed to investigate the active components and mechanisms of action of QWD in the treatment of DKD. The results demonstrated that a total of 13 active components in five types were found in QWD, including flavonoids, flavonoid glycosides, phenylpropionic acids, saponins, coumarins, and lignins. Two key proteins, TGF-β1 and TIMP-1, were identified as the target proteins through molecular docking. Furthermore, QWD significantly suppressed Scr and BUN levels which increased after unilateral ureteral obstruction (UUO). Hematoxylin & eosin (H&E) and Masson staining results demonstrated that QWD significantly alleviated renal interstitial fibrosis in UUO mice. We also found that QWD promoted ECM degradation by regulating MMP-9/TIMP-1 homeostasis to improve renal tubulointerstitial fibrosis and interfere with the expression and activity of TGF- β1 in DKD treatment. These findings explain the underlying mechanism of QWD for the treatment of DKD, and also provide methodological reference for investigating the mechanism of traditional medicine in the treatment of DKD.
Rats ; Mice ; Animals ; Ureteral Obstruction/metabolism* ; Kidney/metabolism* ; Tissue Inhibitor of Metalloproteinase-1/metabolism* ; Molecular Docking Simulation ; Rats, Sprague-Dawley ; Kidney Diseases/drug therapy* ; Extracellular Matrix/metabolism* ; Flavonoids/metabolism* ; Fibrosis

OBJECTIVE: To explore the effect of telmisartan on the expression of metadherin in the kidney of mice with unilateral ureter obstruction. METHODS: Eighteen male C57 mice were randomized into sham-operated group, model group and telmisartan treatment group. In the latter two groups, renal interstitial fibrosis as the result of unilateral ureter obstruction (UUO) was induced by unilateral ureteral ligation with or without telmisartan intervention. Renal pathological changes of the mice were assessed using Masson staining, and immunohistochemistry and Western blotting were used to detect the expression of extracellular matrix proteins and metadherin in the kidney of the mice. In the experiment, cultured mouse renal tubular epithelial cells (mTECs) were stimulated with transforming growth factor-β1 (TGF-β1) and transfected with a siRNA targeting metadherin, and the changes in the expressions of extracellular matrix proteins and metadherin were detected using Western blotting. RESULTS: The expressions of extracellular matrix proteins and metadherin increased significantly in the kidney of mice with UUO ( < 0.05). Intervention with telmisartan significantly lowered the expressions of extracellular matrix proteins and metadherin and alleviated the pathology of renal fibrosis in mice with UUO ( < 0.05). In cultured mTECs, siRNA-mediated knockdown of metadherin obviously reversed TGF-β1-induced increase in the expressions of extracellular matrix proteins and metadherin. CONCLUSIONS Telmisartan can suppress the production of extracellular matrix proteins and the expression of metadhein to attenuate UUO-induced renal fibrosis in mice.
Angiotensin II Type 1 Receptor Blockers ; Animals ; Antihypertensive Agents ; Extracellular Matrix Proteins ; metabolism ; Fibrosis ; Kidney ; drug effects ; metabolism ; pathology ; Male ; Membrane Proteins ; genetics ; metabolism ; Mice ; Mice, Inbred C57BL ; RNA, Small Interfering ; Random Allocation ; Telmisartan ; pharmacology ; Transforming Growth Factor beta1 ; pharmacology ; Ureteral Obstruction ; complications ; metabolism

BACKGROUND: Soluble epoxide hydrolase (sEH) expressed by endothelial cells catalyzes the metabolism of epoxyeicosatrienoic acids (EETs), which are vasoactive agents. METHODS: We used a unilateral ureteral obstruction mouse model of kidney fibrosis to determine whether inhibition of sEH activity reduces fibrosis, the final common pathway for chronic kidney disease. RESULTS: sEH activity was inhibited by continuous release of the inhibitor 12-(3-adamantan-1-ylureido)-dodecanoic acid (AUDA) for 1 or 2 weeks. Treatment with AUDA significantly ameliorated tubulointerstitial fibrosis by reducing fibroblast mobilization and enhancing endothelial cell activity. In an in vitro model of endothelial-to-mesenchymal transition (EndMT) using human vascular endothelial cells (HUVECs), AUDA prevented the morphologic changes associated with EndMT and reduced expression of fibroblast-specific protein 1. Furthermore, HUVECs activated by AUDA prevented the epithelial-to-mesenchymal transition (EMT) of tubular epithelial cells in a co-culture system. CONCLUSION: Our findings suggest that regulation of sEH is a potential target for therapies aimed at delaying the progression of kidney fibrosis by inhibiting EndMT and EMT.
Animals ; Coculture Techniques ; Endothelial Cells* ; Epithelial Cells ; Epithelial-Mesenchymal Transition ; Fibroblasts ; Fibrosis* ; Humans ; In Vitro Techniques ; Kidney* ; Metabolism ; Mice ; Renal Insufficiency, Chronic ; Ureteral Obstruction

BACKGROUND: Soluble epoxide hydrolase (sEH) expressed by endothelial cells catalyzes the metabolism of epoxyeicosatrienoic acids (EETs), which are vasoactive agents. METHODS: We used a unilateral ureteral obstruction mouse model of kidney fibrosis to determine whether inhibition of sEH activity reduces fibrosis, the final common pathway for chronic kidney disease. RESULTS: sEH activity was inhibited by continuous release of the inhibitor 12-(3-adamantan-1-ylureido)-dodecanoic acid (AUDA) for 1 or 2 weeks. Treatment with AUDA significantly ameliorated tubulointerstitial fibrosis by reducing fibroblast mobilization and enhancing endothelial cell activity. In an in vitro model of endothelial-to-mesenchymal transition (EndMT) using human vascular endothelial cells (HUVECs), AUDA prevented the morphologic changes associated with EndMT and reduced expression of fibroblast-specific protein 1. Furthermore, HUVECs activated by AUDA prevented the epithelial-to-mesenchymal transition (EMT) of tubular epithelial cells in a co-culture system. CONCLUSION: Our findings suggest that regulation of sEH is a potential target for therapies aimed at delaying the progression of kidney fibrosis by inhibiting EndMT and EMT.
Animals ; Coculture Techniques ; Endothelial Cells* ; Epithelial Cells ; Epithelial-Mesenchymal Transition ; Fibroblasts ; Fibrosis* ; Humans ; In Vitro Techniques ; Kidney* ; Metabolism ; Mice ; Renal Insufficiency, Chronic ; Ureteral Obstruction

BACKGROUND/AIMS: There has been controversy about the role of Toll-like receptor 2 (TLR2) in renal injury following ureteric obstruction. Although inhibition of the renin angiotensin system (RAS) reduces TLR2 expression in mice, the exact relationship between TLR2 and RAS is not known. The aim of this study was to determine whether the RAS modulates TLR2. METHODS: We used 8-week-old male wild type (WT) and TLR2-knockout (KO) mice on a C57Bl/6 background. Unilateral ureteral obstruction (UUO) was induced by complete ligation of the left ureter. Angiotensin (Ang) II (1,000 ng/kg/min) and the direct renin inhibitor aliskiren (25 mg/kg/day) were administrated to mice using an osmotic minipump. Molecular and histologic evaluations were performed. RESULTS: Ang II infusion increased mRNA expression of TLR2 in WT mouse kidneys (p < 0.05). The expression of renin mRNA in TLR2-KO UUO kidneys was significantly higher than that in WT UUO kidneys (p < 0.05). There were no differences in tissue injury score or mRNA expression of monocyte chemotactic protein 1 (MCP-1), osteopontin (OPN), or transforming growth factor beta (TGF-beta) between TLR2-KO UUO and WT UUO kidneys. However, aliskiren decreased the tissue injury score and mRNA expression of TLR2, MCP-1, OPN, and TGF-beta in WT UUO kidneys (p < 0.05). Aliskiren-treated TLR2-KO UUO kidneys showed less kidney injury than aliskiren-treated WT UUO kidneys. CONCLUSIONS: TLR2 deletion induced activation of the RAS in UUO kidneys. Moreover, inhibition of both RAS and TLR2 had an additive ameliorative effect on UUO injury of the kidney.
Amides/*pharmacology ; Angiotensin II/pharmacology ; Animals ; Disease Models, Animal ; Fibrosis ; Fumarates/*pharmacology ; Kidney/*drug effects/metabolism/pathology ; Male ; Mice, Inbred C57BL ; Mice, Knockout ; Nephritis, Interstitial/genetics/metabolism/pathology/*prevention & control ; RNA, Messenger/genetics/metabolism ; Renin/*antagonists & inhibitors/metabolism ; Renin-Angiotensin System/*drug effects ; Toll-Like Receptor 2/deficiency/drug effects/genetics/*metabolism ; Ureteral Obstruction/*drug therapy/genetics/metabolism/pathology

To isolate bone marrow mesenchymal stem cells (BM-MSCs) and establish the model of chronic kidney disease (CKD) of Wuzhishan (WZS) mini-pig, and to study the repairment effect of BM-MSCs on CKD-induced renal fibrosis in vitro.
 Methods: Density gradient method was used to isolate and culture BM-MSCs. The cells were verified by morphology, phenotype, differentiation and so on. The left partial ureteral obstruction (LPUUO) was used to establish the CKD model, which was evaluated by B-ultrasound, single-photon emission computed tomography (SPECT), HE and Masson staining. The cells were divided into 3 groups, the tissue plus BM-MSCs group, the tissue group, and the BM-MSCs group, respectively. Seven days later, the supernatants were collected to observe the changes of hepatocyte growth factor (HGF) cumulative release. HE and Masson staining was used to observe the changes of renal tissue.
 Results: The isolated BM-MSCs possessed the features as follow: fibroblast-like adherent growth; positive in CD29 and CD90 expression while negative in CD45 expression; osteogenic induction and alizarin red staining were positive; alcian blue staining were positive after chondrogenic induction. Twelve weeks after the operation of LPUUO, B-ultrasound showed the thin renal cortical with pelvis effusion; SPETCT showed the left kidney delayed filling and renal impairment. The accumulation of HGF in the tissue plus BM-MSCs group was significantly higher than that in the tissue alone group at the 1st, 5th, 6th, 7th day, respectively (P<0.05). HE staining showed the different degree of renal lesions between the tissue plus BM-MSCs+CKD group and the tissue alone group, which was aggravated with the time going. Masson staining showed that the cumulative optical density of blue-stained collagen fibers in tissue plus BM-MSCs group was significantly lower than that in the tissue group at the 5th to 7th day (P<0.05).
 Conclusion: BM-MSCs from WZS mini-pig can inhibit or delay the progress of CKD-induced renal fibrosis through autocrine HGF in vitro.
Animals ; Autocrine Communication ; physiology ; Bone Marrow Cells ; Cells, Cultured ; Fibrosis ; physiopathology ; prevention & control ; Hepatocyte Growth Factor ; metabolism ; Kidney ; drug effects ; pathology ; physiopathology ; Mesenchymal Stem Cells ; drug effects ; Renal Insufficiency, Chronic ; complications ; physiopathology ; Swine ; Swine, Miniature ; Ureteral Obstruction ; complications

BACKGROUNDSrc homology 2 domain-containing protein tyrosine phosphatase-2 (SHP-2) is a kind of intracellular protein tyrosine phosphatase. Studies have revealed its roles in various disease, however, whether SHP-2 involves in renal fibrosis remains unclear. The aim of this study was to explore the roles of myeloid cells SHP-2 in renal interstitial fibrosis.

METHODSMyeloid cells SHP-2 gene was conditionally knocked-out (CKO) in mice using loxP-Cre system, and renal interstitial fibrosis was induced by unilateral ureter obstruction (UUO). The total collagen deposition in the renal interstitium was assessed using picrosirius red stain. F4/80 immunostaing was used to evaluate macrophage infiltration in renal tubular interstitium. Quantitative real-time polymerase chain reaction and enzyme linked immunosorbent assay were used to analyze the production of cytokines in the kidney. Transferase-mediated dUTP nick-end labeling stain was used to assess the apoptotic renal tubular epithelial cells.

RESULTSSrc homology 2 domain-containing protein tyrosine phosphatase-2 gene CKO in myeloid cells significantly reduced collagen deposition in the renal interstitium after UUO. Macrophage infiltration was evidently decreased in renal tubular interstitium of SHP-2 CKO mice. Meanwhile, the production of pro-inflammatory cytokines was significantly suppressed in SHP-2 CKO mice. However, no significant difference was observed in the number of apoptotic renal tubular epithelial cells between wild-type and SHP-2 CKO mice.

CONCLUSIONSOur observations suggested that SHP-2 in myeloid cells plays a pivotal role in the pathogenesis of renal fibrosis, and that silencing of SHP-2 gene in myeloid cells may protect renal from inflammatory damage and prevent renal fibrosis after renal injury.

Animals ; Enzyme-Linked Immunosorbent Assay ; Female ; Fibrosis ; enzymology ; pathology ; Immunohistochemistry ; Kidney Diseases ; enzymology ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Myeloid Cells ; metabolism ; Protein Tyrosine Phosphatase, Non-Receptor Type 11 ; genetics ; metabolism ; Ureteral Obstruction ; enzymology ; pathology

OBJECTIVETo observe the effect of Shenluotong Decoction (SD) on serum levels of aldosterone, monocyte chemoattractant protein-1 (MCP-1), α-smooth muscle protein (α-SMA), and nuclear factor-KB (NF-κB) in obstructive nephropathy rats, and to explore the initial mechanism of SD for inhibiting renal interstitial fibrosis.

METHODSTotally 48 healthy Wistar rats were randomly divided into the sham-operation group (n =12) and the model group (n =36). Renal interstitial fibrosis rat model was established by unilateral ureteral obstruction (UUO). After successful modeling, 36 rats were randomly divided into the model group, the Chinese medicine group, and the Western medicine group, 12 in each group. Eplerenone was added in the forage at the daily dose of 100 mg/kg for rats in the Western medicine group. Chinese medicine was added in the forage at the daily dose of 26 g/kg for rats in the Chinese medicine group. Equal volume of normal saline was administered to rats in the sham-operation group and the model group. All medication was performed once daily. The obstructive kidneys were extracted ten days after medication. The pathomorphological changes were observed. The contents of serum aldosterone and MCP-1, and the protein or mRNA expression of MCP-1, α-SMA, and NF-KB were detected.

RESULTSCompared with the sham-operation group, infiltration of a large amount of inflammatory cells and collagen deposition significantly increased, serum contents of aldosterone and MCP-1 obviously increased (P < 0.01), the expression of MCP-1 mRNA and protein were significantly up-regulated (P <0.01), the protein expression of α-SMA and NF-KB were significantly enhanced in the model group (P <0.01). Com- pared with the model group, infiltration of inflammatory cells and renal collagen deposition were attenua- ted in the Chinese medicine group and the Western medicine group, the serum MCP-1 level were reduced, and the mRNA and protein expression of MCP-1 were significantly down-regulated (P <0.01), the protein expression of α-SMA and NF-KB were obviously inhibited (P <0. 01). At the same time, serum aldosterone level was reduced in the Chinese medicine group (P <0.01).

CONCLUSIONSinflammatory lesions of the renal tissue could promote the progress of interstitial fibrosis in rats with obstructive nephropathy. SD could attenuate interstitial fibrosis through reducing serum contents of aldosterone and MCP-1, down-regulating MCP-1/ NF-KB, and inhibiting the expression of α-SMA.

Animals ; Chemokine CCL2 ; drug effects ; metabolism ; Down-Regulation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Fibrosis ; Kidney ; drug effects ; Kidney Diseases ; drug therapy ; genetics ; NF-kappa B ; drug effects ; metabolism ; RNA, Messenger ; biosynthesis ; Rats, Sprague-Dawley ; Ureteral Obstruction ; drug therapy ; genetics