544: Pressure Induces Epithelial Mesenchymal Transition [EMT] in Renal Epithelial Cells [EC]
Year: 2006
Type: conference-abstract
Abstract: INTRODUCTION AND OBJECTIVE: EMT is an important biological process in which EC lose their epithelial phenotype and instead express characteristics associated with mesenchymal cells.EC which have undergone EMT express characteristics of fibroblasts including an elongated shape, expression of Fibroblast Specific protein-1 [FSP-1] and the capacity to synthesize collagen.EMT contributes to important processes in development, metastasis and fibrosis.Unilateral ureteral obstruction [UUO] is characterized by decreases in renal function, tubular cell atrophy and apoptosis, and interstitial fibrosis.Recent studies have provided direct evidence for EMT in UUO.Changes in interstitial and intrapelvic pressure are also characteristic of UUO, especially early in obstructive disease.We have developed a system to pressurize cells in vitro and provide evidence that pressure RESULTS: in EMT of renal EC.METHODS: HKC-8 cells [ human renal EC line] were placed in culture and were subject to pressure when they reached approximately 50 -60% confluence.Cells were subject to pressure [ 0-120 mm Hg] for up to 36 hours.Expression of FSP-1 was assessed using PCR, immunoperoxidase [IP] and immunofluorescence [IF].An antibody to S-100A4 [identical to FSP-1] was used for both the IP and IF assays.For IF, slides were also stained with DAPI to identify nuclei.IF slides were observed by epifluorescent microscopy (Nikon Eclipse TE-2000); TGF-f3 and Collagen I expression were assessed by PCR.Results: HKC-8 cells subject to pressure were compared to cells under ambient pressure.By ten hours of incubation, some cells had undergone the shape change characteristic of EMT.Cells exposed to 60 mm Hg for 16 hours demonstrated both increased TGF-f3 mRNA expression and expression of Collagen I mRNA as compared to cells exposed to ambient pressure.Increased FSP mRNA expression was noted by 10 hours.After 36 hours, increased FSP expression was found using both IP and IF.Cells incubated without primary antibody showed no staining CONCLUSIONS: UUO is characterized by increased fibrosis; EMT and FSP-1 expression have been demonstrated in UUO.It has been previously shown that both TGF-f3 and stretch induce EMT in renal EC.We now demonstrate that pressure is an additional inducer of EMT in renal EC.It is known that TGF-f3, stretch and pressure are all increased in the obstructed kidney.Our results suggest that these changes can contribute to the fibrosis of UUO, through their effects on EMT.Further this suggests that EMT could be a target for intervention in UUO.
Source: The Journal of Urology
Language: English
Topic: TGF-β signaling in diseases
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2793135255