Resveratrol promotes apoptosis and G2/M cell cycle arrest of fibroblast-like synoviocytes in rheumatoid arthritis through regulation of autophagy and the serine-threonine kinase-p53 axis.

Introduction: Resveratrol, a polyphenol extracted from many plant species, has emerged as a promising pro-apoptotic agent in various cancer cells. However, the role of resveratrol in cell proliferation and apoptosis of fibroblast-like synoviocytes in rheumatoid arthritis (RA-FLS) is not fully understood. The study was aimed at elucidating the role of resveratrol in cell proliferation and apoptosis of RA-FLS and the underlying molecular mechanism. Material and methods: Cultured RA-FLSs were subjected to tumour necrosis factor α (TNF-α). The cell proliferation was measured by Cell Counting Kit-8 assay. Cell apoptosis and cell cycle of RA-FLSs were determined by flow cytometry. The levels of apoptosis or autophagy or cell cycle-related protein were detected by immunoblot analysis. Results: In our study, we confirmed that resveratrol reversed TNF-α mediated cell proliferation in RA-FLS. Meanwhile, resveratrol blocked cells at the G2/M stage and reduced the ratio of S phase cells through upregulation of p53 and consequently led to apoptotic cell death. Quite interestingly, we found that resveratrol reversed TNF-α-induced autophagy. Inhibition of autophagy by resveratrol or autophagy inhibitor or Beclin-1 siRNA suppressed TNF-α mediated cell survival and promoted cell apoptosis. However, the autophagy inducer rapamycin (RAPA) reversed the effect of resveratrol on autophagy and cell proliferation. Mechanistic studies revealed that resveratrol inhibited the activation of the phosphoinositide 3-kinases/serine-threonine kinase (PI3K/AKT) pathway. Inhibition of PI3K/AKT pathway by inhibitor LY294002 or resveratrol increased the expression of p53 and decreased the expression of cycle protein (cyclin B1), which further led to block cells in the G2/M arrest. Conclusions: Our preliminary study indicated that resveratrol may suppress RA-FLS cell survival and promote apoptosis at least partly through regulation of autophagy and the AKT-p53 axis.

Mitochondrial Lon protease promotes CD4+ T cell activation by activating the cGAS-STING-TBK1 axis in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease in which autoreactive CD4+ T cells play an essential role. We extracted CD4+ T cells from SLE-prone Fcgr2b-/- mice to elaborate the mechanism of mitochondrial Lon protease in CD4+ T cell activation in SLE. Transcriptome sequencing was performed in SLE-prone Fcgr2b-/- mice, and the stimulator of interferon gene (STING) related to SLE was obtained. It was demonstrated that STING expression was elevated in CD4+ T cells in SLE-prone Fcgr2b-/- mice. The downstream genes and pathways of STING were predicted by GO and KEGG approaches. The data indicated that STING regulated IFN signaling to promote CD4+ T cell activation in SLE-prone Fcgr2b-/- mice. Next, the interaction of cGAS, STING, TBK1, and IFN-I was verified by Co-IP assay. Moreover, the roles of cGAS, STING, and TBK1 in activating CD4+ T cells from SLE-prone Fcgr2b-/- mice were evaluated using gain- or loss-of-function experiments. Mechanistically, cGAS upregulated the IFN-I signaling pathway by directly interacting with STING and TBK1, contributing to CD4+ T cell activation. Besides, cytosolic mtDNA could activate CD4+ T cell activation in SLE-prone Fcgr2b-/- mice by upregulating the cGAS-STING-TBK1 axis. The function of mitochondrial Lon protease in oxidative damage and mtDNA release in CD4+ T cells of SLE-prone Fcgr2b-/- mice were explored. Mitochondrial Lon protease enhanced mtDNA release into the cytoplasm under oxidative stress. Collectively, our work indicates that mitochondrial Lon protease enhances CD4+ T cell activation by inducing mtDNA leakage and offers new candidate targets for developing diagnostic and therapeutic strategies.

Panoramic view of clinical features of lupus erythematosus: a cross-sectional multicentre study from China.

OBJECTIVE: Lupus erythematosus (LE) is a complicated disease with highly heterogeneous clinical manifestations. Previous studies have rarely included all subgroups of patients with lupus and have overlooked the importance of the cutaneous manifestations thereof. We aimed to compare the demographic and clinical differences among patients with different subtypes of lupus. METHODS: This is the first real-world study with a relatively large sample size that simultaneously includes patients with isolated cutaneous lupus erythematosus (iCLE) and SLE. All samples were obtained from the Lupus Erythematosus Multicenter Case-control Study in Chinese populations (LEMCSC) (registration number: ChiCTR2100048939). Comparative analyses between different LE subgroups were performed. RESULTS: A total of 2097 patients with lupus were included, with 1865 patients with SLE, 1648 with cutaneous lupus erythematosus (CLE), and 232 with iCLE. Among the patients with CLE, 1330 had acute cutaneous lupus erythematosus (ACLE); 160 had subacute cutaneous lupus erythematosus (SCLE); and 546 had chronic cutaneous lupus erythematosus (CCLE). The study included a relatively large number of patients with CCLE subtypes, including 311 with discoid lupus erythematosus (DLE), 262 with chilblain lupus erythematosus (CHLE) and 45 with lupus erythematosus profundus (LEP). Demographic characteristics, systemic involvement, mucocutaneous manifestations and autoantibodies were significantly different among the groups. CONCLUSIONS: CLE and iCLE are two distinct disease states, and the selection of broad or narrow CLE definitions should be emphasised in scientific reports. LE-non-specific cutaneous lesions imply more severity, while self-reported photosensitivity and LE-specific cutaneous manifestations imply milder severity. Generalised ACLE appears to be a more severe state than localised ACLE, and CHLE appears to be more severe than DLE. Anti-Sjögren's syndrome-related antigen B (SSB) antibodies have higher specific directivity than anti-Sjögren's syndrome-related antigen A (SSA) antibodies for SCLE lesions. Anti-double-stranded DNA antibodies have a higher co-occurrence with ACLE and a lower co-occurrence with SCLE and CCLE. Compared with DLE, CHLE has significantly higher positive rates of anti-SSA/Ro60 (71%) and anti-SSA/Ro52 (42.4%) antibodies, whereas LEP is associated with a higher positive rate of antinucleosome antibodies (31.1%).

A comparison and review of three sets of classification criteria for systemic lupus erythematosus for distinguishing systemic lupus erythematosus from pure mucocutaneous manifestations in the lupus disease spectrum.

Although the original purpose of the systemic lupus erythematosus (SLE) classification criteria was to distinguish SLE from other mimic diseases, and to facilitate sample selection in scientific research, they have become widely used as diagnostic criteria in clinical situations. It is not known yet if regarding classification criteria as diagnostic criteria, what problems might be encountered? This is the first study comparing the three sets of classification criteria for SLE, the 1997 American College of Rheumatology (ACR'97), 2012 Systemic Lupus International Collaborating Clinics (SLICC'12) and 2019 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR'19), for their ability to distinguish patients with SLE from patients with pure mucocutaneous manifestations (isolated cutaneous lupus erythematosus without internal disease, i-CLE) in the lupus disease spectrum. 1,865 patients with SLE and 232 patients with i-CLE were recruited from a multicenter study. We found that, due to low specificity, none of the three criteria are adept at distinguishing patients with SLE from patients with i-CLE. SLICC'12 performed best among the original three criteria, but if a positive ANA was removed as an entry criterion, EULAR/ACR'19 would performed better. A review of previous studies that compared the three sets of criteria was presented in this work.

Safety and efficacy of Rituximab in systemic sclerosis: A systematic review and meta-analysis.

PURPOSE: Rituximab is widely prescribed to treat systemic sclerosis (SSc) by the depletion of pathogenic B cells. Nonetheless, the clinical benefit of Rituximab in SSc remains contentious. This meta-analysis was conducted to systematically evaluate the safety and efficacy profile of Rituximab in SSc patients. PATIENTS AND METHODS: We performed a systematic online query in PubMed, Cochrane, and Web of Science. The available studies on the use of Rituximab in SSc patients were comprehensively reviewed and investigated. RESULTS: In total, 14 studies, including 597 participants, were analyzed. Pooled results showed the long-term improvement in the modified Rodnan skin score (mRSS) for skin function (ΔmRSS: 7.00 at 6 months, 9.70 at 12 months, and 10.93 at 24 months), while forced vital capacity (FVC) (ΔFVC: -0.69 at 6 months, -2.62 at 12 months, and -0.67 at 24 months) and diffusing capacity of the lungs for carbon monoxide (DLCO) (ΔDLCO: -2.39 at 6 months, -3.28 at 12 months, and -0.79 at 24 months) for lung function remained stable in SSc patients after Rituximab treatment. The rate of Rituximab-related adverse events was 12% in the pooled results. CONCLUSION: The pooled results of this meta-analysis indicated that Rituximab is well tolerated, and it is able to improve cutaneous function and stabilize pulmonary function in SSc patients.

Anti-cyclic citrullinated peptide antibody predicts the development of rheumatoid arthritis in patients with undifferentiated arthritis.

BACKGROUND: Clinical outcomes of undifferentiated arthritis (UA) are diverse, and only 40% of patients with UA develop rheumatoid arthritis (RA) after 3 years. Discovering predictive markers at disease onset for further intervention is critical. Therefore, our objective was to analyze the clinical outcomes of UA and ascertain the predictors for RA development. METHODS: We performed a prospective, multi-center study from January 2013 to October 2016 among Chinese patients diagnosed with UA in 22 tertiary-care hospitals. Clinical and serological parameters were obtained at recruitment. Follow-up was undertaken in all patients every 12 weeks for 2 years. Predictive factors of disease progression were identified using multivariate Cox proportional hazards regression. RESULTS: A total of 234 patients were recruited in this study, and 17 (7.3%) patients failed to follow up during the study. Among the 217 patients who completed the study, 83 (38.2%) patients went into remission. UA patients who developed RA had a higher rheumatoid factor (RF)-positivity (42.9% vs. 16.8%, χ = 8.228, P = 0.008), anti-cyclic citrullinated peptide (CCP) antibody-positivity (66.7% vs. 10.7%, χ = 43.897, P < 0.001), and double-positivity rate of RF and anti-CCP antibody (38.1% vs. 4.1%, χ = 32.131, P < 0.001) than those who did not. Anti-CCP antibody but not RF was an independent predictor for RA development (hazard ratio 18.017, 95% confidence interval: 5.803-55.938; P < 0.001). CONCLUSION: As an independent predictor of RA, anti-CCP antibody should be tested at disease onset in all patients with UA.

T cell receptor ß repertoires as novel diagnostic markers for systemic lupus erythematosus and rheumatoid arthritis.

OBJECTIVE: T cell receptor (TCR) diversity determines the autoimmune responses in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) and is closely associated with autoimmune diseases prognosis and prevention. However, the characteristics of variations in TCR diversity and their clinical significance is still unknown. Large series of patients must be studied in order to elucidate the effects of these variations. METHODS: Peripheral blood from 877 SLE patients, 206 RA patients and 439 healthy controls (HC) were amplified for the TCR repertoire and sequenced using a high-throughput sequencer. We have developed a statistical model to identify disease-associated TCR clones and diagnose autoimmune diseases. RESULTS: Significant differences were identified in variable (V), joining (J) and V-J pairing between the SLE or RA and HC groups. These differences can be utilised to discriminate the three groups with perfect accuracy (V: area under receiver operating curve > 0.99). One hundred ninety-eight SLE-associated and 53 RA-associated TCRs were identified and used for diseases classification by cross validation with high specificity and sensitivity. Disease-associated clones showed common features and high similarity between both autoimmune diseases. SLE displayed higher TCR heterogeneity than RA with several organ specific properties. Furthermore, the association between clonal expansion and the concentration of disease-associated clones with disease severity were identified, and pathogen-related TCRs were enriched in both diseases. CONCLUSIONS: These characteristics of the TCR repertoire, particularly the disease-associated clones, can potentially serve as biomarkers and provide novel insights for disease status and therapeutical targets in autoimmune diseases.

Molecular analysis of oral microflora in patients with primary Sjögren's syndrome by using high-throughput sequencing.

BACKGROUND: The objective of this study was to characterize the oral microflora profile of primary Sjögren's syndrome (pSS) patients, thereby revealing the connection between oral bacterial composition and dental caries, and to identify the "core microbiome" in the oral cavities of pSS patients and systemic healthy individuals by using a high-throughput sequencing technique. METHODS: Twenty-two pSS patients and 23 healthy controls were enrolled in this study. Their clinical data and oral rinse samples were collected. The V3-V4 hypervariable regions of the bacterial 16S rRNA gene of samples were amplified and analyzed by high-throughput sequencing on the Illumina Miseq PE300 platform. RESULTS: Both two groups were age- and sex-matched. There were significantly higher decayed, missing and filled teeth (DMFT) and decayed, missing and filled surfaces (DMFS) in the pSS group than in the control group (p < 0.01). Alpha diversity was depleted in pSS patients, compared with healthy controls (p < 0.01), while beta diversity between the two groups was not significantly different. Seven discriminative genera (LDA > 4) were found between the two groups in LEfSe (LDA Effect Size) analysis. The relative abundance of Veillonella in pSS patients was fourfold higher, while Actinomyces, Haemophilus, Neisseria, Rothia, Porphyromonas and Peptostreptococcus were significantly lower in pSS patients than in healthy controls. However, the correlation between Veillonella and DMFT/DMFS was not significant (p > 0.05). In Venn diagram analysis, nine genera shared by all samples of two groups, which comprised 71.88% and 67.64% in pSS patients and controls, respectively. DISCUSSION: These findings indicate a microbial dysbiosis in pSS patients; notably, Veillonella might be recognized as a biomarker in pSS patients. The core microbiome in pSS patients was similar to the systemic healthy population. These provide insight regarding advanced microbial prevention and treatment of severe dental caries in pSS patients. This study also provides basic data regarding microbiology in pSS.

Identification of ANKDD1B variants in an ankylosing spondylitis pedigree and a sporadic patient.

BACKGROUND: Ankylosing spondylitis (AS) is a debilitating autoimmune disease affecting tens of millions of people in the world. The genetics of AS is unclear. Analysis of rare AS pedigrees might facilitate our understanding of AS pathogenesis. METHODS: We used genome-wide linkage analysis and whole-exome sequencing in combination with variant co-segregation verification and haplotype analysis to study an AS pedigree and a sporadic AS patient. RESULTS: We identified a missense variant in the ankyrin repeat and death domain containing 1B gene ANKDD1B from a Han Chinese pedigree with dominantly inherited AS. This variant (p.L87V) co-segregates with all male patients of the pedigree. In females, the penetrance of the symptoms is incomplete with one identified patient out of 5 carriers, consistent with the reduced frequency of AS in females of the general population. We further identified a distinct missense variant affecting a conserved amino acid (p.R102L) of ANKDD1B in a male from 30 sporadic early onset AS patients. Both variants are absent in 500 normal controls. We determined the haplotypes of four major known AS risk loci, including HLA-B*27, 2p15, ERAP1 and IL23R, and found that only HLA-B*27 is strongly associated with patients in our cohort. CONCLUSIONS: Together these results suggest that ANKDD1B variants might be associated with AS and genetic analyses of more AS patients are warranted to verify this association.

[Research progress in renal injury relevant to primary Sjögren's syndrome].

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease characterized by lymphoplasmacytic infiltration of the exocrine glands that results in multiple organs and systems damage. Renal injury affects 0.3%-27.0% patients. The most frequent form of nephropathy in pSS is tubulointerstitial nephritis. The main clinical manifestation is renal tubular acidosis. The renal prognosis in patients with pSS is usually favorable, but renal failure may occur. At present, it still lacks of strict consensus or guideline for the treatment.

Associations between the SLC22A12 gene and gout susceptibility: a meta-analysis.

OBJECTIVES: The aim of this study is to explore whether the polymorphisms of rs475688 and rs3825016 in the solute carrier family 22 member 12 (SLC22A12) gene are associated with the susceptibility to gout or hyperuricaemia. METHODS: Relevant studies were enrolled by searching databases systematically. The pooled odds ratios (ORs) with 95% confidence interval (CI) were used to evaluate the associations. Q-test and I2 statistics were used to evaluate the heterogeneity. Publication bias was evaluated using Begg's funnel plots and Egger regression test. RESULTS: A total of 7 articles involving 1216 patients and 1844 healthy controls were included in this meta-analysis. Significant association was detected between rs475688 polymorphism and gout susceptibility in three genetic models (C vs. T: OR=1.464, 95% CI 1.078-1.989, p=0.015; CC+CT vs. TT: OR=2.028, 95% CI 1.488-2.763, p=0.000; CC vs. CT+TT: OR=2.226, 95% CI 1.746-2.838, p=0.000). Significant association was observed between rs3825016 polymorphism and hyperuricaemia susceptibility only in allelic comparison (C vs. T: OR=1.274, 95% CI 1.101-1.474, p=0.001). CONCLUSIONS: The rs475688 polymorphism is associated with gout susceptibility. The correlation between rs3825016 polymorphism of SLC22A12 and hyperuricaemia susceptibility is possible.

[Clinical effect of tocilizumab on patients with severe active rheumatoid arthritis].

OBJECTIVE: To evaluate therapeutic effects and adverse reactions of tocilizumab on patients with severe active rheumatoid arthritis (RA).
 Methods: Twelve patients with severe refractory RA were treated with tocilizumab. The clinical and laboratory indices and the side effects were recorded after treatment.
 Results: The clinical and laboratory indices and the disease activity score 28 (DAS28) were observed in all patients, which were significantly improved after TCZ therapy (P<0.05), and no obvious adverse reactions were found.
 Conclusion: Tocilizumab can effectively relieve the symptoms and improve the conditions of severe active RA.

An update on the animal models in hyperuricaemia research.

Hyperuricaemia is a metabolic disease caused by purine metabolic abnormalities, mainly due to the increased formation or reduced excretion of uric acid. In recent years, it has been proved that hyperuricaemia is an important risk factor for chronic kidney disease (CKD) and cardiovascular disease, and it also takes part in the pathophysiology of metabolic syndrome. In addition, more attention has been concentrated on the pathogenesis or treatment of hyperuricaemia. Since establishing an animal model on hyperuricaemia is the foundation for further researches, several methods to establish the hyperuricaemia model have been developed. In this article, remarkable progress on the modelling approach are summarised, and a comparison study on different methods of developing hyperuricaemia animal models was conducted.

IFI44L promoter methylation as a blood biomarker for systemic lupus erythematosus.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a clinically heterogeneous disease with limited reliable diagnostic biomarkers. We investigated whether gene methylation could meet sensitivity and specificity criteria for a robust biomarker. METHODS: IFI44L promoter methylation was examined using DNA samples from a discovery set including 377 patients with SLE, 358 healthy controls (HCs) and 353 patients with rheumatoid arthritis (RA). Two independent sets including 1144 patients with SLE, 1350 HCs, 429 patients with RA and 199 patients with primary Sjögren's syndrome (pSS) were used for validation. RESULTS: Significant hypomethylation of two CpG sites within IFI44L promoter, Site1 (Chr1: 79 085 222) and Site2 (Chr1: 79 085 250; cg06872964), was identified in patients with SLE compared with HCs, patients with RA and patients with pSS. In a comparison between patients with SLE and HCs included in the first validation cohort, Site1 methylation had a sensitivity of 93.6% and a specificity of 96.8% at a cut-off methylation level of 75.5% and Site2 methylation had a sensitivity of 94.1% and a specificity of 98.2% at a cut-off methylation level of 25.5%. The IFI44L promoter methylation marker was also validated in an European-derived cohort. In addition, the methylation levels of Site1 and Site2 within IFI44L promoter were significantly lower in patients with SLE with renal damage than those without renal damage. Patients with SLE showed significantly increased methylation levels of Site1 and Site2 during remission compared with active stage. CONCLUSIONS: The methylation level of IFI44L promoter can distinguish patients with SLE from healthy persons and other autoimmune diseases, and is a highly sensitive and specific diagnostic marker for SLE.

Smad Anchor for Receptor Activation Regulates High Glucose-Induced EMT via Modulation of Smad2 and Smad3 Activities in Renal Tubular Epithelial Cells.

BACKGROUND: SARA is an essential adaptor protein in TGF-ß1 signaling and it is also involved in the process of Epithelial-mesenchymal transition (EMT) and fibrosis. Our aim was to investigate the effect of SARA on high glucose (HG)-induced EMT and extracellular matrix (ECM) synthesis in renal tubular epithelial cells. METHODS: The cells were transfected with the following plasmids: wild-type SARA (SARA-WT), SARA-dSBD (SARA with Smad binding domain deletion) and then subjected to HG ambience (30 mM). The expression levels were assessed by Western-blot, real-time PCR and immunofluorescence. RESULTS: HG-induced EMT phenotype with increased expression of ECM protein in HK-2 cells. This was associated with the decreased expression of SARA and Smad2. In comparison with the HG group, overexpression of SARA in HK-2 cells, a relatively high upregulation of ZO-1 expression was seen, while that of Vimentin, fibronectin and collagen I was decreased. The Smad2 protein expression was increased in HK-2 cells after transfection with SARA (WT) plasmid. Interestingly, the overexpression of SARA prolonged the activity period of Smad2 and shortened that of Smad3, which seemed consistent with the change of EMT phenotype and ECM changes in HK-2 cell induced by HG. CONCLUSIONS: SARA regulates HG-induced EMT and ECM excretion via modulation of the activation of Smad2 and Smad3 in renal tubular epithelial cells. In view of these findings, it is conceivable that SARA may serve as a potential novel target in pre-EMT states for the amelioration renal fibrosis seen in chronic kidney diseases.

Pharmacogenomics of biological treatment in rheumatoid arthritis.

INTRODUCTION: Rheumatoid arthritis (RA) demonstrates a high heterogeneity in clinical responses to treatment. Although the efficacy of biological therapy has undoubtedly been established, the response differs considerably between individuals. This variability between individuals has aroused the research for biomarkers predictive of treatment response. Pharmacogenomics underlying individual responses to drugs is rapidly developed and has the potential of realizing the personalized therapy in RA. This review will summarize the pharmacogenomics of biological therapies approved for clinical RA treatment. AREAS COVERED: The pharmacogenomics underlies individual responses to biological drugs in RA. Current studies on pharmacogenomics of biological therapy in RA are presented. EXPERT OPINION: The personalized treatment in RA according to pharmacogenomics is promising, but the available pharmacogenomic data on biological treatment in RA are not adequate and consistent and still require further larger sample studies to corroborate.

[Meta analysis of infection risks of anti-TNF-α treatment in rheumatoid arthritis].

OBJECTIVE: To systematically evaluate the risks of anti-TNF-α treatment-associated infection, severe infection and tuberculosis in rheumatoid arthritis (RA) patients, and to reduce the infection incidences associated with anti-TNF-α therapy. METHODS: We used Meta analysis to systematically review randomized controlled trials on anti- TNF-α treatment associated risks of infection, severe infection and tuberculosis in RA patients. RESULTS: Although no statistically significant differences were detected in TB risk between anit- TNF-α treatment and the control group (0.5% vs 0.07%; P=0.27, OR=1.85, 95% CI: 0.62-5.52), there still existed a clinically obvious elevation of TB risk in monoclonal anti-TNF-α treatment, which was illustrated by the results that no TB case was reported in the etanercept group, but 11 TBs in 2050 infliximab-treated cases, and 3 TBs in 722 adalimumab-treated cases. The total infection and severe infection risks were also significantly higher in patients receiving anti-TNF-α treatment (P<0.05). Subanalysis revealed that etanercept showed no significantly higher infection or severe infection risk than control group (P>0.05), while both kinds of monoclonal antibodies of TNF-α blockers showed a significantly elevated infection or severe infection risks (P<0.05). High doses of anti-TNF-α treatment were associated with statistically increased risks of severe infection (6.0% vs 2.8%, P=0.04, OR=1.68, 95% CI: 1.02-2.78). CONCLUSION: The TB risk of anti-TNF-α treatment deserves close attention, especially in places with high rate of BCG vaccination and MTb infection. Monoclonal anti-TNF-α treatment brings higher risks of infection and severe infection than soluble TNF-α receptor.

HSP47 regulates ECM accumulation in renal proximal tubular cells induced by TGF-ß1 through ERK1/2 and JNK MAPK pathways.

Heat shock protein (HSP)47 is a collagen-specific molecular chaperone that is essential for the biosynthesis of collagen molecules. It is likely that increased levels of HSP47 contribute to the assembly of procollagen and thereby cause an excessive accumulation of collagens in disease processes associated with fibrosis. Although HSP47 promotes renal fibrosis, the underlying mechanism and associated signaling events have not been clearly delineated. We examined the role of HSP47 in renal fibrosis using a rat unilateral ureteral obstruction model and transforming growth factor (TGF)-ß(1)-treated human proximal tubular epithelial (HK-2) cells. An upregulation of HSP47 in both in vivo and in vitro models was observed, which correlated with the increased synthesis of extracellular matrix (ECM) proteins and expression of tissue-type plasminogen activator inhibitor (PAI)-1. Blockade of HSP47 by short interfering RNA suppressed the expression of ECM proteins and PAI-1. In addition, TGF-ß(1)-induced HSP47 expression in HK-2 cells was attenuated by ERK1/2 and JNK MAPK inhibitors. These data suggest that ERK1/2 and JNK signaling events are involved in modulating the expression of HSP47, the chaperoning effect of which on TGF-ß(1) would ultimately contribute to renal fibrosis by enhancing the synthesis and deposition of ECM proteins.

[New pathologic classification of diabetic nephropathy (retrospective study of 37 cases)].

OBJECTIVE: To investigate the new pathological classification of diabetic nephropathy (DN) published by Research Committee of the Renal Pathology Society in 2010. METHODS: Renal biopsy specimens were obtained from 37 patients with type 2 diabetes mellitus with micro-albuminuria (MAU) or clinical albuminuria (CAU). These samples were classified according to new pathological classification for DN and new standard scores for interstitial vascular injury. RESULTS: Before the classification, DN was seen in 26 palients. After re-analysis according to the new pathological classification, the patients diagnosed with DN increased to 32. In these 32 DN patients, 1 was classified as type I, 3 as type IIa, 2 as type IIb, 23 as type III and 3 as type IV; 12 patients had mild interstitial injury, 15 had midrange interstitial injury, while 5 had severe interstitial injury. CONCLUSION: The new pathological classification of DN can increase the diagnosis rate and attract more attention to tubular and interstitial damage in DN, contributing to the early diagnosis and treatment of DN.

Low-dose paclitaxel ameliorates fibrosis in the remnant kidney model by down-regulating miR-192.

Transforming growth factor (TGF)-ß has been shown to play a central role in the development of tubulointerstitial fibrosis, which can be corrected via treatment with paclitaxel. The biology of microRNA (miR) can be modulated by paclitaxel. We hypothesized that paclitaxel may attenuate renal fibrosis in a rat model of remnant kidney disease by inhibiting TGF-ß induced-miRs. Rats in groups of 12 were subjected to 5/6 nephrectomy and received low-dose intraperitoneal injection of paclitaxel. Renal functions were assessed at 8 weeks. The TGF-ß signalling cascade and ECM proteins were evaluated by real-time polymerase chain reaction (TRT-PCR) and immunofluorescence microscopy. Animals with remnant kidneys developed hypertension, which was not relieved with paclitaxel treatment. However, paclitaxel treatment resulted in dampening the proteinuric response, reduction in serum BUN, creatinine levels and urine protein : creatinine ratio and normalization of creatinine clearance. These effects were accompanied by the inhibition of Smad2/3 activation, attenuation of renal fibrosis and normalization of integrin-linked kinase (ILK), COL(I)A1, COL(IV)A2 and α-SMA expression. Also, paclitaxel down-regulated the expression of miR-192, miR-217 and miR -377, while miR-15 was up-regulated in the remnant kidney. In vitro, in tubular epithelial cells (NRK-52E), paclitaxel also inhibited TGF-ß1-induced Smad2/3 activation and normalized ILK, COL(I)A1, COL(IV)A2 and α-SMA expression. Furthermore, ChIP analyses indicated that Taxol suppressed Smad3-mediated miR-192 transcriptional activity. Over-expression of miR-192 in NRK-52E mimicked the changes seen in the remnant kidney, while inclusion of miR-192 inhibitor in the culture medium blocked TGF-ß1-induced COL(I)A1 and COL(IV)A2 expression, while ILK and α-SMA were unaffected. These data suggest that low-dose paclitaxel ameliorates renal fibrosis via modulating miR-192 pathobiology and TGF-ß/Smad signalling.