Study Of Urinary TWEAK/Fn14 MRNA In Lupus Nephritis

Background: Systemic lupus erythematosus(SLE)is a chronic autoimmune disease with multi system and organ involvements.It is characterized by a variety of autoantibodies in the serum,the anti-nuclear antibody as the representative.The natural course of lupus is characterized by an alternation of aggravation and remission.Lupus nephritis(LN)is a common and severe complication of SLE.LN has higher morbidity and mortality.The clinical manifestation of LN is complex and varied with hematuria,proteinuria,pyuria,tube type of urine and kidney function decline.Sometimes LN can develop into acute renal failure or end-stage renal disease.Renal biopsy is still the gold standard in the diagnosis of LN and LN pathological classification.Renal biopsy has important guiding significance for treatment,but this invasive method has some limitations in actual clinical practice.With the advances of reliable RNA extraction and real-time PCR techniques,quantification of m RNA expression in urinary sediment has emerged as a novel strategy for screening new biomarkers in SLE and LN.Tumor necrosis factor like weak inducer of apoptosis(TWEAK)is a new member of the tumor necrosis factor superfamily.TWEAK is a multifunctional cytokine that regulates cell survival,growth,migration,inflammation and differentiation by its own known signaling receptor,fibroblast growth factor-inducible 14(Fn14),thereby activating the NF-k B signaling pathways.TWEAK/Fn14 may be involved in the pathogenesis of SLE and LN in a variety of ways.The aim of this study was to use Real-time PCR method for determination of urinary m RNA of TWEAK,Fn14 and MCP-1 in SLE patients,and compared with the clinical indicators of common lupus activity,to investigate the value of urine TWEAK,Fn14 and MCP-1 m RNA levels.The aim of this study is through immunohistochemical method to study different types of LN patients with kidney pathological tissues in the expression level and the location of a TWEAK,Fn14.To observe its relationships with local infiltration of immune cells and to explore the role of TWEAK/Fn14 on the pathogenesis of LN.Method: 1.In this study,31 cases of patients with active SLE(including 15 patients diagnosed with lupus nephritis and 16 patients with no renal involvement)and healthy controls were studied.Urinary cell pellet was collected from each study participant.Total RNA was extracted and c DNA was synthetized.Urine TWEAK,Fn14 and MCP-1 m RNA level were quantified by real-time PCR technology,and correlations between target m RNAs and clinical parameters were examined.2.We used immunohistochemical method to study 40 cases of LN renal puncture tissue.The expression of CD3,CD20,CD68,TWEAK and Fn14 of the renal tissue wax blocks in the patients with LN and control group were detected,and the relationship of the inflammatory cells infiltrating in the pathology of LN kidney was preliminarily discussed.3.We followed up 31 patients with active SLE for 3 years.To investigate the relationship between therapeutic response and urinary TWEAK and Fn14 m RNA levels at baseline and after 3 years was studied.Results: 1.The levels of urinary TWEAK,Fn14 and MCP-1 m RNA were significantly increased in patients with active LN.The expression levels of target gene m RNA were positively correlated with 24 h urinary proteins,SLEDAI and serum anti-ds DNA antibodies.The ROC curve evaluation showed that three urine m RNAs were able to distinguish renal involvement in SLE patients from non-renal involvement and healthy control..2.TWEAK and Fn14 are widely expressed in the cytoplasm of renal tubular epithelial cells of various types of LN.Some glomerular mesangial cells,endothelial cells,and capillary walls are expressed in small amounts.TWEAK,Fn14 expression levels of type ?,? LN patients are more than type ?,? LN.The highest expression level is type ? LN.The expression level of TWEAK was positively correlated with Fn14 level,CD3,CD20 and CD68 positive cells.3.ROC curve evaluation indicated that baseline urine Fn14 m RNA,anti-ds DNA antibody titer,and SLEDAI can predict the therapeutic response of SLE patients to conventional therapy.The higher the urine Fn14 m RNA level in SLE patients,the worse the response to conventional therapy.SLE patients with persistent elevated urine m RNA levels of TWEAK and Fn14 had poor therapeutic response.Conclusion: 1?Urine TWEAK,Fn14 and MCP-1 m RNA levels suggested active renal involvement in SLE patients.Urine TWEAK,Fn14 and MCP-1 m RNA may be biomarkers for renal involvement in SLE patients.2?TWEAK and Fn14 are widely expressed in the cytoplasm of renal tubular epithelial cells of various types of LN.Some glomerular mesangial cells,endothelial cells,and capillary walls are expressed in small amounts.The highest expression level is type ? LN.The expression level of TWEAK was positively correlated with Fn14 level,CD3,CD20 and CD68 positive cells.It is suggested that TWEAK/Fn14 pathway may participate in the LN pathological process by inducing inflammatory cell infiltration.3?The higher baseline level of urine Fn14 m RNA or urine TWEAK,Fn14 m RNA levels continue to rise in SLE patients,the worse the response to conventional therapy of hormone combined immunosuppressive drugs.The detection of urine TWEAK and Fn14 m RNA may be a biomarker for predicting the response of SLE.