OBJECTIVE: To explore the role of transforming growth factor-β1/integrin-linked kinase/fibroblast-specific protein 1 (TGF- β1/ILK/FSP1) signaling pathway in cyclosporine A (CsA)-induced renal tubular epithelial cell transdifferentiation. METHODS: Rat renal tubular epithelial NRK-52E cells were induced with 1 mg/L CsA, treated with TGF-β1 inhibitor (SB431542, 10 μmol/L), or transfected with the ILK-RNAi lentiviral expression vector (ILKshRNA) or a negative control vector before CsA induction. The expressions of TGF-β1, ILK and FSP-1 mRNAs and proteins in the cells were detected using real-time PCR and Western blotting. The positive cells for α-SMA expression were detected by immunohistochemistry. RESULTS: Compared with the blank control cells, the cells treated with CsA showed significantly increased levels of TGF-β1, ILK and FSP-1 mRNAs and proteins ( < 0.05). The expressions of TGF-β1, ILK and FSP-1 were significantly lower in TGF-β1 inhibitor group than in CsA group ( < 0.05). The levels of ILK and FSP-1 were significantly decreased after shRNA-mediated ILK silencing ( < 0.05). The number of positive cells for -SMA was significantly lower in cells treated with SB431542 and in cells with ILK silencing than in the cells treated with CsA alone ( < 0.05). CONCLUSIONS The activation of TGF-β1/ILK/FSP-1 signaling pathway is an important mechanism for CsA-induced transdifferentiation in rat renal tubular epithelial cells. ILK participates in CsA-induced epithelialmesenchymal transition of renal tubular epithelial cells.
Animals ; Calcium-Binding Proteins ; Cells, Cultured ; Cyclosporine ; Epithelial Cells ; Epithelial-Mesenchymal Transition ; Protein-Serine-Threonine Kinases ; Rats ; Signal Transduction ; Transforming Growth Factor beta1

Objective:To investigate the effect of specific inhibition of transforming growth factor-β1 (TGF-β1) with SB-431542 on the Smad2/3 and integrin-linked kinase (ILK) signaling molecules in tubule interstitial fibrosis(TIF)-induced cyclosporine A(CsA) in mouse.Methods:50 BALB/c mice were randomly divided into 5 groups (10 mice per group):the CsA model group (CMG),the interventional model group (IMG),the solvent control group (SCG),the low-salt control group (LCG),and the normal control group (NCG).The model mouse was established with low-sodium diet and intragastric administration of cyclosporine A,which was dissolved in olive oil at a dose of 60 mg/(kg·d).After 4 weeks,a specific inhibitor of TGF-β1 (SB-431542)was administered intraperitoneally with 10 mg/(kg·2 d) for 10 days (every other days).Mice were sacrificed at day 38.Serum creatinine (Scr) was measured,hydroxyp roline (Hyp)level and morphological changes of renal tissue were analyzed,expression levels of TGF-β1,P-Smad 2/3 and ILK were respectively detected by immunohistochemistry or Western blot,mRNA levels of TGF-β1,Smad 2/3 and ILK were respectively detected real-time polymerase chain reaction (RT-PCR).Results:Compared with three control groups (NCG,LCG and SCG),mice weight was decreased significantly,Scr level was increased significantly in two modeling groups (CMG and IMG) (P<0.01),and these changes in CMG were more obvious than those of IMG (P<0.05).Different levels of tubulointerstitial injury,interstitial infiltration of inflammatory cells and blue collagen staining in two modeling groups were observed,and particularly evident in CMG.TGF-β1,P-Smad2/3 and ILK immunostaining were mainly expressed in tubulointerstitium.The TGF-β1,P-Smad2/3 and ILK mRNA and immunostaining levels in two modeling groups were significantly increased as compared with three control groups (P<0.01),but their levels in IMG were significantly lower than those of CMG (P<0.05).The level of Hyp in renal tissue was positively correlated with Scr,TGF-β1,Smad2/3 and ILK (r=0.860,0.711,0.776,0.676,P<0.01).Conclusion:The activation of the TGF-β1/Smads signaling pathway plays an important role in the development of chronic CsA-induced TIF.The activation of ILK is closely correlated with the development of TIF,and may be used as a downstream factor of TGF-β1/Smads signaling pathway in regulating CsA-induced TIF.

BACKGROUND: Magnetic resonance imaging(MRI)is considered safe for diagnosis of meniscus injury,having accuracy as high as 80% to 100%.However,it is found that there are some false positive and false negative in the clinic.OBJECTIVE: Through assessment of menisci injuries of the knee using magnetic resonance imaging and arthroscopy,to investigate MRI manifestation in different types of meniscal injuries.METHODS: A study from January 2003 to December 2008 was performed in 212 patients with knee injury undergoing preoperative MRI.Radiograph was read by physicians who had a senior professional title from radiology and orthopaedics departments,and meniscus damage and damage morphology were predicted.Arthroscopy was conducted by chief physician.Meniscus damage during surgery was considered as gold standards.The accuracy of them was compared.The statistics of accuracy of MRI diagnosis was gathered.RESULTS AND CONCLUSION: Totally 212 patients and 230 knees were included,and a total of 215 knees of meniscus injury were described by MRI diagnosis and 213 knees of meniscus injury were proven by arthroscopy.The sensitivity,specificity and accuracy of MRI diagnosis of meniscus injury respectively were 93.5%,64.7%,93.0%.It is found that the sensitivity of MRI diagnosis of bucket-handle damage is high.MRI is easy to miss diagnosis in a light meniscus posterior horn tear,and resuts are more false positive in lateral meniscus injury.It needs arthroscope operation or further surgery in some condition such as gradeⅢ type injury,meniscus displacement after injury and articular capsule separation,which indicates instable meniscus.