The Molecular Mechanism Of Renal Interstitial Fibrosis And Colchicine Preventive Effect

Renal Interstitial Fibrosis (RIF), a major consequence and common pathway of all kidney diseases associated with progression to end-stage renal failure, is the result of proliferation of fibroblasts within the interstitium, infiltration of the interstitium by monocytes or inflamed cells, and the excess production of matrix within the interstitium. The severity and degree of RIF is strongly correlation between renal functional loss and the prognosis of renal patients, recent studies have shown that histological grading of the fibrosis of the tubulointerstitium is more closely correlated with the loss of renal function than the histological grading of glomerulosclerosis. The mechanisms of RIF, especially the molecular pathogenesis of which, were little understood, So the recent interests of nephrologists have focused on elucidating pathogenesis of RIF and how to ameliorate the courses of progressive renal diseases.As a specific microtubule disrupter, colchicine has been succeeding used for centuries in treatment of gout. Recently its anti-inflammatory and antifibrotic properties of colchicine have been employed for an increasing number of suggested and approved indications of anti-fibrosis effects (including primary biliary cirrhosis, idiopathic pulmonary fibrosis, liver fibrosis). However, the effects of colchicine on the RIF were unclear.In order to research the mechanisms of RIF, and to understand the roles of treatment of RIF by colchicine, the present study consists five parts.Part I: Morphological research on treatment of RIF in rats with Unilateral ureteral obstruction (UUO) by colchicineObjective: The purpose of this study was to observe the effects of colchicine on RIF in UUO rats.Methods: 26 male Sprague-Dawley rats were divided into three groups: sham-operated control group (16 rats), colchicine-treated group (20 rats): UUO + colchicine 100ug/kg.d I.P for 5 days per week, model group (group of unilateral ureteral obstruction, 20 rats): UUO+ saline 100ug/kg.d I.P for 5 days per week. The rats of three groups were sacrificed at 3, 7, 14, 21 days. The renal tissues were stained by hematoxylin and eosin (HE), periodic acid-Schiff reaction (PAS), Masson's trichrome in general morphological research; and expression of PCNA and COL III were also evaluated immunohistochemically in this study.Results: (1) the extensive and progressive of renal tubular lesions were found in morphologically in UUO in rats, the changes of tubular damages were ameliorated after treatment with colchicine. Colchicine could be beneficial in regenerations of renal tubular epithelial cells, and inhibit the inflammatory cells infiltration in tubulointerstitium. (2) The numbers of infiltrated cells in interstitium were significantly loss in colchicine-treatment groups than those of model groups. (3) Colchicine could decrease the deposition of extracellular matrix (including collagen type III) in renal tubulointerstitium space.Conclusion: Colchicine had beneficial effects on interstitial fibrosis in rats with UUO Sprague-Dawley.Part II: The study on molecular mechanisms of renal interstitial fibrosis and its influences of that with treatment of colchicineObjective: To Screen the genes involved in RIF and investigate the effect of colchicine on the fibrosis and to elucidate the expression profile of cytokines and chemokines in UUO rats.Methods: (1) The gene expression pattern of renal tissues from both UUO group and those from colchicine-treated group was detected by cDNA microarray and the resulting information was analyzed with bioinformatics. (2)The expression pattern of TGF-β1, IL-1β, VCAM-1, and ICAM-1 were confirmed by RT-PCR and immunohistochemistry.Results: (1) Differently expressed gene pattern consists of the genes encode the Immune/cell adhesiveness, transcription of DNA, post-transcriptional modification of protein, signal transduction, cell division and differentiation, energy metabolism, substance transportation, as well as cytoskeleton associated gene nes...