Figure 1.
Rapamycin decreases the PM deterioration in a PD mouse model. Mice received a daily instillation of standard PD fluid (2 mL per day) through a intraperitoneal catheter during 4 weeks with or without the oral administration of Rapamycin (2 mg/kg/day: PDF, n = 5, and PDF + Rapamycin, n = 6). A control group of mice that were only exposed to the presence of the catheter was also included (control; n = 6). Peritoneal samples were prepared and analyzed as described in Materials and Methods section. (a) Standard PD fluid exposure increases matrix deposition (blue stained zones) and the thickness of the PM (black lines), while Rapamycin administration significantly reduces these effects when measured in Masson's trichrome staining (sections representative slides). Magnification 200x. (b) As shown in immunofluorescence staining of cytokeratin (red) and FSP-1 (green) (counterstained with DAPI in blue), PDF exposure-promoted MMT (cells coexpressing cytokeratin and FSP-1 with double positive staining, yellow) is reduced by Rapamycin administration. Magnification 400x. (c) The peritoneal thickness (μm) is increased in PDF group compared with control mice, and the group PDF with Rapamycin shows a significant reduction of thickness when compared with PDF group. Analysis of variance results in a significance of p = 0.001 (one-way ANOVA test). (d) Measurement of TGF-β1 (pg/mL) in the drained volumes shows a gentle increase (although not statistically significant) of this growth factor in PD fluid-instilled animals while Rapamycin administration tends to reduce TGF-β1 production. The analysis of variance results in a p value of 0.146 (one-way ANOVA test). (e) Numbers of mesothelial cells per field suffering MMT increase during PDF exposition, while Rapamycin is able to reduce the occurrence of this pathological process. The analysis of variance results in a significance of p < 0.0001 (one-way ANOVA test). Box plots graphics represent the median, minimum, and maximum values, as well as the 25th and 75th percentiles. Numbers above boxes depict means ± SE. Symbols represent the statistical differences between groups analyzed by Mann-Whitney U test.