Thioredoxin-interacting protein (TXNIP) is an important regulatory protein for thioredoxin (TRX) that elicits the generation of reactive oxygen species (ROS) by inhibiting the redox function of TRX. Abundant evidence suggests that TXNIP is involved in the fibrotic process of diabetic kidney disease (DKD). However, the potential mechanism of TXNIP in DKD is not yet well understood. In this study, we found that TXNIP knockout suppressed renal fibrosis and activation of mammalian target of rapamycin complex 1 (mTORC1) and restored transcription factor EB (TFEB) and autophagy activation in diabetic kidneys. Simultaneously, TXNIP interference inhibited epithelial-to-mesenchymal transformation (EMT), collagen I and fibronectin expression, and mTORC1 activation, increased TFEB nuclear translocation, and promoted autophagy restoration in HK-2 cells exposed to high glucose (HG). Rapamycin, an inhibitor of mTORC1, increased TFEB nuclear translocation and autophagy in HK-2 cells under HG conditions. Moreover, the TFEB activators, curcumin analog C1 and trehalose, effectively restored HG-induced autophagy, and abrogated HG-induced EMT and collagen I and fibronectin expression in HK-2 cells. Taken together, these findings suggest that TXNIP deficiency ameliorates renal fibrosis by regulating mTORC1/TFEB-mediated autophagy in diabetic kidney diseases.

Kidney fibrosis is considered to be the ultimate aggregation pathway of chronic kidney disease (CKD), but its underlying mechanism remains elusive. Protein kinase C-delta (PKC-δ) plays critical roles in the control of growth, differentiation, and apoptosis. In this study, we found that PKC-δ was highly upregulated in human biopsy samples and mouse kidneys with fibrosis. Rottlerin, a PKC-δ inhibitor, alleviated unilateral ureteral ligation (UUO)-induced kidney fibrosis, inflammation, VDAC1 expression, and cGAS-STING signaling pathway activation. Adeno-associated virus 9 (AAV9)-mediated VDAC1 silencing or VBIT-12, a VDAC1 inhibitor, attenuated renal injury, inflammation, and activation of cGAS-STING signaling pathway in UUO mouse model. Genetic and pharmacologic inhibition of STING relieved renal fibrosis and inflammation in UUO mice. In vitro, hypoxia resulted in PKC-δ phosphorylation, VDAC1 oligomerization, and activation of cGAS-STING signaling pathway in HK-2 cells. Inhibition of PKC-δ, VDAC1 or STING alleviated hypoxia-induced fibrotic and inflammatory responses in HK-2 cells, respectively. Mechanistically, PKC-δ activation induced mitochondrial membrane VDAC1 oligomerization via direct binding VDAC1, followed by the mitochondrial DNA (mtDNA) release into the cytoplasm, and subsequent activated cGAS-STING signaling pathway, which contributed to the inflammation leading to fibrosis. In conclusion, this study has indicated for the first time that PKC-δ is an important regulator in kidney fibrosis by promoting cGAS-STING signaling pathway which mediated by VDAC1. PKC-δ may be useful for treating renal fibrosis and subsequent CKD.

Renal fibrosis is the most common pathway in progressive kidney diseases. The unilateral ureteral obstruction (UUO) model is used to induce progressive renal fibrosis. We evaluated the effects of irisin on renal interstitial fibrosis in UUO mice. The GSE121190, GSE36496, GSE42303, and GSE96101 datasets were downloaded from the Gene Expression Omnibus (GEO) database. In total, 656 differentially expressed genes (DEGs) were identified in normal and UUO mouse renal samples. Periostin and matrix metalloproteinase-2 (MMP-2) were selected to evaluate the effect of irisin on renal fibrosis in UUO mice. In UUO mice, irisin ameliorated renal function, decreased the expression of periostin and MMP-2, and attenuated epithelial-mesenchymal transition and extracellular matrix deposition in renal tissues. In HK-2 cells, irisin treatment markedly attenuated TGF-β1-induced expression of periostin and MMP-2. Irisin treatment also inhibited TGF-β1-induced epithelial-mesenchymal transition, extracellular matrix formation, and inflammatory responses. These protective effects of irisin were abolished by the overexpression of periostin and MMP-2. In summary, irisin treatment can improve UUO-induced renal interstitial fibrosis through the TGF-β1/periostin/MMP-2 signaling pathway, suggesting that irisin may be used for the treatment of renal interstitial fibrosis.

Background:The primary pathophysiology of diabetic kidney disease (DKD) is tubulointerstitial fibrosis (TIF), and an essential contributing element is excessive extracellular matrix deposition. Irisin is a polypeptide formed by splitting fibronectin type III domain containing 5 (FNDC5), which participates in a number of physiological and pathological processes.Methods:The purpose of this article is to examine irisin's function in DKD and analyze both its in vitro and in vivo effects. The Gene Expression Omnibus (GEO) database was used to download GSE30122, GSE104954, and GSE99325. Analysis of renal tubule samples from nondiabetic and diabetic mice identified 94 differentially expressed genes (DEGs). The transforming growth factor beta receptor 2 (TGFBR2), irisin, and TGF-β1 were utilized as DEGs to examine the impact of irisin on TIF in diabetic kidney tissue, according to the datasets retrieved from the GEO database and Nephroseq database. Additionally, the therapeutic impact of irisin was also examined using Western blot, RT-qPCR, immunofluorescence, immunohistochemistry, and kits for detecting mouse biochemical indices.Results:In vitro, the findings demonstrated that irisin not only down-regulated the expression of Smad4 and β-catenin but also reduced the expression of proteins linked to fibrosis, the epithelial-mesenchymal transition (EMT), and mitochondrial dysfunction in HK-2 cells maintained in high glucose (HG) environment. In vivo, overexpressed FNDC5 plasmid was injected into diabetic mice to enhance its expression. Our studies found that overexpressed FNDC5 plasmid not only reversed the biochemical parameters and renal morphological characteristics of diabetic mice but also alleviated EMT and TIF by inhibiting Smad4/β-catenin signaling pathway.Conclusion:The above experimental results revealed that irisin could reduce TIF in diabetic mice via regulating the Smad4/β-catenin pathway.

Tubulointerstitial fibrosis (TIF) is an important pathological change that occurs during the development of diabetic kidney disease. The epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells is a manifestation of TIF. STAT1, a member of the STAT family of transcription factors, can be modified by the small ubiquitin-related modifier (SUMO), thus affecting the activity of STAT1. The present study investigated the role of STAT1 SUMOylation in high glucose-induced tubular EMT by western blotting, immunocytochemistry, immunofluorescence, co-immunoprecipitation and dual luciferase reporter analysis. The results indicated that in the process of high glucose-induced EMT, STAT1 activation protected the cells from EMT. However, high glucose also increased the SUMOylation of STAT1, which prevented STAT1 from exerting an effective protective role by inhibiting its activity.

目的:探讨思维导图结合翻转课堂的教学方法对病理教学的影响.方法:以试卷测评和问卷调查的形式,评价不同教学方法在病理教学中的效果.结果:应用思维导图结合翻转课堂的实验组学生成绩明显优于对照组(P＜0.01);并且80％以上的学生认可新的教学方法.结论:思维导图结合翻转课堂的教学方法对病理教学效果有显著的促进作用.

Tubular injury is one of the crucial determinants of progressive renal failure in diabetic nephropathy (DN), while epithelial-to-mesenchymal transition (EMT) of tubular cells contributes to the accumulation of matrix protein in the diabetic kidney. Activation of the nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome leads to the maturation of interleukin (IL)-1B and is involved in the pathogenic mechanisms of diabetes. In this study, we explored the role of NLRP3 inflammasome on high glucose (HG) or transforming growth factor-B1 (TGFB1)-induced EMT in HK-2 cells. We evaluated EMT through the expression of α-smooth muscle actin (α-SMA) and E-cadherin as well as the induction of a myofibroblastic phenotype. Reactive oxygen species (ROS) was observed using the confocal microscopy. HG was shown to induce EMT at 48 h, which was blocked by NLRP3 silencing or antioxidant N-acetyl-L-cysteine (NAC). We found that NLRP3 interference could inhibit HG-induced ROS. Knockdown of NLRP3 could prevent HG-induced EMT by inhibiting the phosphorylation of SMAD3, P38 MAPK and ERK1/2. In addition, P38 MAPK and ERK1/2 might be involved in HG-induced NLRP3 inflammasome activation. Besides, TGFB1 induced the activation of NLRP3 inflammasome and the generation of ROS, which were blocked by NLRP3 interference or NAC. Tubular cells exposed to TGFB1 also underwent EMT, and this could be inhibited by NLRP3 shRNA or NAC. These results indicated that knockdown of NLRP3 antagonized HG-induced EMT by inhibiting ROS production, phosphorylation of SMAD3, P38MAPK and ERK1/2, highlighting NLRP3 as a potential therapy target for diabetic nephropathy.

It is high incidence of tubulointerstitial lesion (TIL) in lupus nephritis (LN) and TIL can affect the prognosis of patients with LN. Signal transducer and activator of transcription (STAT) 3 was activated in LN and STAT3 inhibition could delay the onset of LN. Here, we evaluated the role of a well-known STAT3 inhibitor, S3I-201, on TIL in lupus nephritis. STAT3 was activated in MRL/lpr mice (a mouse model of lupus nephritis), and treatment with S3I-201 inhibited the activation of it. The level of 24-h urine protein and nitrogen urea increased in MRL/lpr mice and adminstration of S3I-201 reduced the level of urinary protein. In addition, S3I-201 attenuated the expression of α-smooth muscle actin (α-SMA), Fibronectin (FN) proteins, as well as the expression of monocyte chemotactic factor-1 (MCP-1) and intercellular adhesion molecule (ICAM-1). However, the expression of E-cadherin improved when treatment with S3I-201. These results revealed that the activation of STAT3 mediates tubulointerstitial lesion in mice with LN. S3I-201, by suppressing STAT3 activity, has therapeutic effect in lupus nephritis.

Thioredoxin-interacting protein (TXNIP) is associated with inflammation, tubulointerstitial fibrosis, and oxidative stress in diabetic kidney disease, yet the potential role of TXNIP in nondiabetic renal injury is not well known. This study aimed to investigate the effect of TXNIP on renal injury by creating a unilateral ureteral obstruction (UUO) model in TXNIP knockout (TKO) mice. We performed sham or UUO surgery in 8-week-old TXNIP KO male mice and age and sex-matched wild-type (WT) mice. Animals were killed at 3, 5, 7, or 14 days after surgery, and renal tissues were obtained for RNA, protein, and other analysis. Our results show that the expression of TXNIP was increased in a time-dependent manner in the ligated kidneys. TXNIP deletion reduced renal fibrosis, apoptosis, α-SMA, TGF-β1 and CTGF expression, and activation of Smad3, p38 MAPK, and ERK1/2 in UUO kidneys. We also found UUO-induced renal F4/80+ macrophage infiltration, MCP-1 expression and activation of NF-κB and NLRP3 inflammasome were attenuated in TKO mice. Furthermore, our study revealed that TXNIP deficiency inhibited the expression of 8-OHdG, heme oxygenase-1 (HO-1) and NADPH oxidase 4 (Nox4) in UUO kidney. In summary, our study suggests that TXNIP plays a key role in the renal inflammation and fibrosis induced by UUO. Inhibition of TXNIP may be a strategy to slow the progression of chronic kidney diseases.

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease. Activation of the nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome has been reported in diabetic kidney, yet the potential role of NLRP3 inflammasome in DN is not well known. In this study, we explored the role of NLRP3 inflammasome on inflammation and fibrosis in diabetic kidney using NLRP3 knockout mice. Renal expression of NLRP3, caspase-1 p10, interleukin-18 (IL-18) and cleaved IL-1β was increased in diabetic wild-type (WT) mice at 24 weeks. NLRP3 knockout (KO) improved renal function, attenuated glomerular hypertrophy, glomerulosclerosis, mesangial expansion, interstitial fibrosis, inflammation and expression of TGF-β1 and connective tissue growth factor (CTGF), as well as the activation of Smad3 in kidneys of STZ-induced diabetic mice. In addition, NLRP3 KO inhibited expression of thioredoxin-interacting protein (TXNIP) and NADPH oxidase 4 (Nox4) and superoxide production in diabetic kidneys. The diabetes-induced increase in urinary level of 8-hydroxydeoxyguanosine (8-OHdG) was attenuated in NLRP3 KO mice. In vitro experiments, using HK-2 cells, revealed that high glucose (HG)-mediated expression of TXNIP and Nox4 was inhibited by transfection with NLRP3 shRNA plasmid or antioxidant tempol treatment. Silencing of the NLRP3 resulted in reduced generation of reactive oxygen species (ROS) in HK-2 cells under HG conditions. Furthermore, we also found exposure of IL-1β to HK-2 cells induced ROS generation and expression of TXNIP and Nox4. Taken together, inhibition of NLRP3 inflammasome activation inhibits renal inflammation and fibrosis at least in part via suppression of oxidative stress in diabetic nephropathy.

Nudel is a newly discovered factor related to cell migration. The tubular epithelial-mesenchymal transition (EMT) includes four steps: the loss of the adhesive properties of epithelial cells, the acquisition of a mesenchymal cell phenotype, the destruction of the tubular basal membrane, and the migration into the renal interstitium. The purpose of this study was to investigate the role of Nudel in the high-glucose-induced EMT of tubular epithelial cells. Human renal proximal tubular epithelial cells (HKCs) were treated with Nudel shRNA to clarify the role and mechanism of Nudel in tubular EMT induced by high glucose. We found that Nudel was expressed at a high level in high-glucose-stimulated HKCs, and the expression of Nudel was associated with the activation of signal transducer and activator of transcription 3. After transfection with Nudel shRNA, we detected the expression levels of E-cadherin, α-smooth muscle actin (α-SMA), and the Wiskott-Aldrich syndrome family of proteins (including WASP, N-WASP, WAVE1, WAVE2, and WAVE3) via assay. Cell migration was analyzed by the scratching method. The results showed that high glucose downregulated E-cadherin expression, upregulated α-SMA expression, and promoted the migration of HKCs. The expression levels of N-WASP, WAVE1, and WAVE2 were also elevated in HKCs treated with high glucose. All changes induced by high glucose were ameliorated by Nudel depletion. We conclude that Nudel participates in the transition and the migration of tubular epithelial cells via the regulation of WASP family proteins.

The purpose of this study was to investigate the role of oncostatin M (OSM) in tubulointerstitial lesion (TIL) in lupus nephritis (LN). We found that OSM was highly expressed in the renal tissue of LN mice. OSM is one of the interleukin-6 cytokine family members. In order to clarify the role and mechanism of OSM in LN, mice with LN were treated with anti-OSM antibody or isotype antibody. We evaluated the tubular epithelial-mesenchymal transdifferentiation (EMT) by detecting the E-cadherin, α-smooth muscle actin (α-SMA), and fibronectin (FN) expression. We analyzed the inflammation by observing the monocyte chemotactic factor-1 (MCP-1) and intercellular adhesion molecule (ICAM-1) expression and calculated the tubulointerstitial fibrosis area by Masson staining. The results showed that anti-OSM antibody, rather than isotype antibody, improved EMT, inflammation, and tubulointerstitial fibrosis. In addition, the signal transducer and activator of transcription (STAT) 1 and STAT3 signaling was activated by tyrosine phosphorylation in LN mouse renal tissue, indicating that the phosphorylated STAT1 (p-STAT1) and p-STAT3 were involved in kidney injury. Moreover, decreased p-STAT3 instead of p-STAT1 has been observed after anti-OSM antibody injection. Thus, we concluded that OSM is associated with TIL in lupus nephritis, which may be connected with the activation of STAT3 rather than that of STAT1.

The aim of this study is to investigate the expression of OSM (oncostatin M) in the renal cortex of MRL/lpr mice.MRL/MpJ mice were designated as the control group and MRL/lpr mice were designated as the lupus group.The expression of OSM was detected by the methods of immunohistochemistry and enzyme linked immunosorbent assay.Western blot and quantitative Real-time PCR (qRT-PCR) analysis were used to determine the protein and mRNA expression of E-cadherin,α-SMA (a-smooth muscle actin) and Col Ⅰ (collagen Ⅰ).qRT-PCR analysis was used to detected the expression of fibronectin (FN) mRNA.The results suggested that the OSM expression increased in lupus mice compared with control mice.And the expression level of OSM is positively correlated with blood urea nitrogen,24 h urinary protein and the expression level of α-SMA,Col Ⅰ and FN but is negatively correlated with the expression level of E-cadherin.The results indicated that OSM expression is increased in kidney in lupus mice,which may connected with the renal dysfunction and tubular-epithelial cell transdifferentiation.

Purpose To investigate the effect of grape seed proanthocyanidins on the phenotype-transforming marker protein expression of db/db renal cells in mice model of type 2 diabetes,and to explore the protective mechanism of grape seed extract on diabetic renal injury in db/db mice.Methods Male db/db diabetic mice were randomly divided into two groups:diabetic group (db/db group) and diabetic + grape seed proanthocyanidin extract group (db/db + GSPE).The same week-old male db/m mice was used as normal controls (db/m) and grape seed proanthocyanidin extract gavage treatment group (db/m +grape seed proanthocyanidin extract group,db/m + GSPE).The mice of db/db + GSPE group and db/m + GSPE group were administered daily with grape seed proanthocyanidin extract (5mg/kg) by gavage.Results Renal tissues of db/db diabetic mice showed increased expression of α-SMA,p-p38MAPK,pERK1/2 and 8-OHdG level,and down-regulation in E-cadherin expression compared with db/m group (P ＜ 0.05).However,the alternations of α-SMA,p-p38,p-ERK1/2,E-cadherin protein levels,and 8-OHdG level,in db/db group were reversed by addition of grape seed proanthocyanidin extract (P ＜ 0.05).Conclusion Grape seed proanthocyanidin extract inhibits the epithelial to mesenchymal transition (EMT) associated protein,by decreasing ROS production,and activating p38 MAPK and ERK1/2.These findings suggest that grape seed proanthocyanidin extract provides a treatment option for diabetic nephropathy.

Tumor necrosis factor-α (TNF-α) is suggested to induce mitochondrial dysfunction and apoptosis of renal tubular epithelial cells that possibly exacerbates renal function in chronic kidney disease (CKD). Here we investigated whether suppressor of cytokine signaling-1 (SOCS-1), an inhibitor of cytokine signaling, was involved in TNF-α-induced human renal tubular epithelial cells (HKCs) oxidative stress and apoptosis. TNF-α promoted the protein and mRNA expression of SOCS-1 in a time and dose dependent manner, along with increased cell apoptosis and activation of apoptosis signal regulating kinase-1(ASK1) in HKCs. Furthermore, overexpression of SOCS-1 in HKCs reduced TNF-α-mediated oxidative stress and apoptosis. Meanwhile, We also found that overexpression of SOCS-1 could regulate the activity of JAK/STAT signaling pathway. In addition, a specific JAK2 inhibitor, AG490, that both attenuated TNF-α-induced oxidative stress, also reduced apoptosis. Taken together, overexpression of SOCS-1 prevented TNF-α-mediated cell oxidative stress and apoptosis may be via suppression of JAK/STAT signaling pathway activation in HKCs.

Autophagy is an important homoeostatic mechanism for the lysosomal degradation of protein aggregates and damaged cytoplasmic components. Recent studies suggest that autophagy which is induced by TGF-β1 suppresses kidney fibrosis in renal tubular epithelial cells (RTECs) of obstructed kidneys. Sphingosine kinase 1(SK1), converting sphingosine into endogenous sphingosine-1-phosphate (S1P), was shown to modulate autophagy and involved in the processes of fibrotic diseases. Since SK1 activity is also up-regulated by TGF-β1, we explored its effect on the induction of autophagy and development of renal fibrosis in this study. In vitro, SK1 expression and activity were markedly increased by TGF-β1 stimulation in a time and concentration dependent manner, and concomitant changes in autophagic response were observed in HK-2 cells. Further, knockdown of SK-1 led to a decrease of autophagy whereas overexpression of SK1 caused a greater induction of autophagy. In addition, overexpression of SK1 resulted in decreased of mature TGF-β levels through autophagic degradation. In vivo, SK1 enzymatic activity and autophagic response were both up-regulated in a mouse model of kidney fibrosis induced by unilateral ureteral obstruction (UUO); meanwhile, increased of mature TGF-β1 and deposition of extracellular matrix (ECM) were observed in tubulointerstitial areas compared with sham-operated mice. However, aggravation of renal fibrosis was detected when SK1 inhibitor PF-543 was applied to suppress SK1 enzymatic activity in UUO mice. At the same time, autophagy was also inhibited by PF-543. Thus, our findings suggest that SK1 activation is renoprotective via induction of autophagy in the fibrotic process.

Abnormal lipid metabolism contributes to the renal lipid accumulation, which is associated with diabetic kidney disease, but its precise mechanism remains unclear. The growing evidence demonstrates that thioredoxin-interacting protein is involved in regulating cellular glucose and lipid metabolism. Here, we investigated the effects of thioredoxin-interacting protein on lipid accumulation in diabetic kidney disease. In contrast to the diabetic wild-type mice, the physical and biochemical parameters were improved in the diabetic thioredoxin-interacting protein knockout mice. The increased renal lipid accumulation, expression of acetyl-CoA carboxylase, fatty acid synthase and sterol regulatory element binding protein-1, and phosphorylated Akt and mTOR associated with diabetes in wild-type mice was attenuated in diabetic thioredoxin-interacting protein knockout mice. Furthermore, thioredoxin-interacting protein knockout significantly increased the expression of peroxisome proliferator-activated receptor-α, acyl-coenzyme A oxidase 1 and carnitine palmitoyltransferaser 1 in diabetic kidneys. In vitro experiments, using HK-2 cells, revealed that knockdown of thioredoxin-interacting protein inhibited high glucose-mediated lipid accumulation, expression of acetyl-CoA carboxylase, fatty acid synthase and sterol regulatory element binding protein-1, as well as activation of Akt and mTOR. Moreover, knockdown of thioredoxin-interacting protein reversed high glucose-induced reduction of peroxisome proliferator-activated receptor-α, acyl-coenzyme A oxidase 1 and carnitine palmitoyltransferaser 1 expression in HK-2 cells. Importantly, blockade of Akt/mTOR signaling pathway with LY294002, a specific PI3K inhibitor, replicated these effects of thioredoxin-interacting protein silencing. Taken together, these data suggest that thioredoxin-interacting protein deficiency alleviates diabetic renal lipid accumulation through regulation of Akt/mTOR pathway, thioredoxin-interacting protein may be a potential therapeutic target for diabetic kidney disease.

Purpose To investigate the role of S3I-201 on tubular interstitial lesion in lupus nephritis.Methods MRt/MpJ mice were designated as the control group.MRL/lpr nice were randomly divided into LN group,S3I-201 group and DMSO group.The serum and 24 h-urine were collected to detect the serum creatinine,blood urea nitrogen and urine protein.Immunohistochemistry was used to detect the expression of FN.Western blotting analysis was used to determine the expression of E-cadherin,α-SMA,MCP-1,ICAM1,STAT3 and p-STAT3.Results Compared with the expression level in control group,the protein level of α-SMA,MCP-1,ICAM1 and FN were increased in renal tissue of MRL/lpr mice,while the expression of E-cadherin was markedly decreased.And the STAT3 was activated in renal tissue of MRL/lpr mice.The administration of S3I-201 could inhibite the activation of STAT3 and ameliorate the expression of E-cadherin,α-SMA,MCP-1,ICAM-1 and FN.Conclusion S3I-201 can relieve the tubular interstitial leison,which maybe concerned with the phosphorylation of STAT3.

目的 探讨STAT蛋白在抑瘤素M(oncostatin M,OSM)诱导的肾小管上皮细胞表型转化及分泌功能中的作用.方法 体外培养人肾近曲小管上皮细胞,分为对照组(C组)、OSM(20 ng/ml)组(OSM组)、OSM+雷帕霉素(100 ng/ml)组(OSM+R组)和OSM+氟达拉滨(100 ng/ml)组(OSM+F组).培养72 h后收集细胞及上清液,透射电镜观察细胞超微结构改变;免疫细胞化学和Western blot法检测CK18、d-SMA蛋白表达;采用Western blot法检测信号转导及转录激活因子(STAT1、STAT3、p-STAT1、p-STAT3)的表达;酶联免疫吸附实验测定细胞上清液中Ⅰ型胶原(collagen Ⅰ,Col Ⅰ)和纤维连接蛋白(fibronectin,FN)的分泌.结果 与对照组相比,细胞经OSM刺激后CK18的表达下调,而α-SMA的表达上调并分泌过多的细胞外基质蛋白Col Ⅰ和FN;此外,OSM还可磷酸化激活STAT1和STAT3.OSM的上述作用可被雷帕霉素和氟达拉滨所阻断.结论 OSM具有促纤维化特性,而STAT1和STAT3信号活化在OSM介导的纤维化进程中发挥同等重要的作用.

该文探讨了细胞因子信号传导抑制蛋白1(suppressors ofcytokine sigmaling 1,SOCS1)在糖尿病小鼠肾小管间质病变中的作用.通过腹腔注射链脲佐菌素(streptozotocin,STZ)诱发糖尿病小鼠模型,于成模后8周给予尾静脉快速注射pEF-FLAG-I/mSOCS1质粒(1 mg/kg),每隔7d注射一次.于成模后12周收集标本,检测各组动物的血糖、24 h尿蛋白;应用RT-PCR检测肾组织中SOCS1、角蛋白18(cytokeratin,CK18)和α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA) mRNA的表达;应用免疫组化或Western blot检测SOCS1、CK18、t-SMA和纤维黏连蛋白(fibronectin,FN)的表达;酶联免疫吸附实验检测肾组织中白细胞介素-1β(interleutin-1β,IL-1β)和转化生长因子-β1 (transforming growth factor-β1,TGF-β1)的表达;流式细胞术检测肾皮质中巨噬细胞标志蛋白CD68的表达.结果发现,与对照组相比,糖尿病小鼠肾组织中IL-1β、TGF-β1及FN的表达增强,巨噬细胞的数量增多;此外,肾小管上皮细胞自身标志蛋白CK18的表达减少而肌成纤维细胞标志蛋白α-SMA的表达增强.SOCS1质粒转染能降低24 h尿蛋白、抑制肾组织中CD68、IL-1β、TGF-β1和α-SMA的表达,同时部分恢复CK18的表达.结果表明,SOCS1可能通过抑制肾组织炎症反应和肾小管上皮细胞转分化从而缓解糖尿病小鼠肾小管间质病变.