L-2-oxothiazolidine-4-carboxylic acids slow down dialysate-induced senescence in human peritoneal mesothelial cells.

Peritoneal dialysis induces an intraperitoneal inflammatory reaction, which in the long term may cause deterioration of the peritoneal structure and function as the dialysis membrane. We studied the effect of the overnight effluent dialysate from patients on chronic peritoneal dialysis on aging of the human peritoneal mesothelial cells in an in vitro model of replicative cellular senescence. In the control group cells were cultured in the standard medium and in the studied groups in culture medium mixed 1:1 v/v with the dialysate ± L-2-oxothiazolodine-4-carboxylic acid 1 mmol/L (OTZ). OTZ was used as the precursor for the synthesis of glutathione in these cells. Dialysate accelerated senescence of the mesothelial cells as reflected by elongation of their population doubling time, reduced expression of KI-67 gene, and increased ß-galactosidase activity. Also, expression of the genes regulating the production of the inflammatory mediators (interleukin-6, monocyte chemoattractant protein-1, metalloproteinase-2, hyaluronan), proangiogenic (VEGF) and profibrotic (fibronectin) factors was increased in that group. At the same time, these cells secreted more inflammatory mediators. Simultaneous treatment of the cells with the dialysate and OTZ slowed down their senescence, whose intensity was similar to that in the control group. The results presented in this manuscript prove that the intraperitoneal inflammatory reaction induced by repeated infusions of the dialysis fluid accelerates the senescence of the mesothelial cells, which may result in fibrosis and neoangiogenesis within the peritoneum. Simultaneous supplementation of the cells with a glutathione precursor (OTZ) may prevent the development of these pathological changes.

Effect of resveratrol analogue, DMU-212, on antioxidant status and apoptosis-related genes in rat model of hepatocarcinogenesis.

The aim of the study was to examine whether antioxidant properties of 3,4,4',5-tetramethoxystilbene (DMU-212) contribute to its anticarcinogenic activity and whether DMU-212 affects the expression of apoptosis-related genes. Two-stage model of hepatocarcinogenesis was used; male Wistar rats were challenged with N-nitrosodiethylamine (NDEA), 200 mg/kg body weight (b.w.), intraperitoneal, then phenobarbital (PB) in drinking water (0.05%) was administered. Simultaneously, DMU-212 was given per os at a dose 20 or 50 mg/kg b.w. two times a week for 16 weeks. DMU-212 caused a moderate decrease in hepatic thiobarbituric acid reactive substances and protein carbonyls concentration elevated in rats treated with NDEA/PB. The activity of antioxidant enzymes examined reduced by NDEA/PB treatment was not restored in rats coadministered with DMU-212. Effects of DMU-212 on messenger RNA (mRNA) expression of antioxidant enzymes in rats challenged with NDEA/PB were diversified; no changes in their protein expression were noted in any of the groups. The expression of 17,000 genes was analyzed by Affymetrix® Rat Gene 1.1 ST Array; 15 apoptosis-related genes were selected and validated by RT-q PCR. The combined treatment with NDEA/PB and DMU-212 increased the mRNA level of some genes driving mitochondria-mediated apoptosis, whereas the mRNA expression of some anti-apoptotic genes triggering receptor-mediated apoptosis was reduced. The expression of genes encoding caspases-4, -8, -9, and -12 was also increased in rats treated with DMU-212. Although antioxidant effect of DMU-212 in rats challenged with NDEA/PB was moderate, its potential anticarcinogenic properties were demonstrated as evidenced by modulation of apoptosis-related genes.

Microarray analysis of inflammatory response-related gene expression in the uteri of dogs with pyometra.

Pyometra, which is accompanied by bacterial contamination of the uterus, is defined as a complex disease associated with the activation of several systems, including the immune system. The objective of the study was to evaluate the gene expression profile in dogs with pyometra compared with those that were clinically normal. The study included uteri from 43 mongrel bitches (23 with pyometra, 20 clinically healthy). RNA used for the microarray study was pooled to four separated vials for control and pyometra. A total of 17,138 different transcripts were analyzed on the uteri of female dogs with pyometra and of healthy controls. From 264 inflammatory response-related transcripts, we found 23 transcripts that revealed a 10- to 77-fold increased expression. Thereby, the expression of interleukin 8 (IL8), interleukin-1-beta (IL1B), interleukin 18 receptor (IL18RAP), interleukin 1-alpha (IL1A), interleukin receptor antagonist (IL1RN) and interleukin 6 (IL6) increased 77-, 20-, 17-, 13-, 13- and 11-fold, respectively. Furthermore, the expression of the calcium binding proteins S100A8 was 44-fold higher, and that of S100A12 and S100A9 37-fold, respectively, in the uteri of canines with pyometra compared with that of the controls. Moreover, the expression of the transcripts of toll-like receptors (TLR8 and TLR2), integrin beta 2 (ITGB2), chemokine ligand 3 (CCL3), semaphorin 7A (SEMA7A), CD14 and prostaglandin-endoperoxide synthase 2 (PTGS2) was increased between 10- and 18-fold. Furthermore, after using RT-qPCR we found an increased expression of AOAH, IL1A, IL8, CCL3, IL1RN and SERPINE 1 mRNAs which can be served also as markers of the occurrence of pyometra in domestic bitches. In summary, it is concluded that up-regulation of interleukins may be used as a marker of the inflammatory response in dogs with pyometra. Moreover, all of the 23 up-regulated transcripts may be novel molecular markers of the pathogenesis of canine pyometra. Several proteins--–products of these genes--may be recognized as potential biomarkers of this disease or as therapeutic targets in other mammalian species, including humans.

The in vitro culture supplements and selected aspects of canine oocytes maturation.

The maturation of oocytes is one of the most important steps determining their developmental competence. Due to the low percentage of oocytes of bitches that reach the MII stage, searching for reagents that may stimulate the growth and maturation of oocytes is still present in this species of mammals. The most important media supplements include gonadotropins (LH, FSH, hCG), growth factors (IGF, TGF, EGF, FGF), progesterone and follicular fluid. It is suggested that the supplement of EGF, and/or follicular cells may have an important influence on the percentage of cells that reach the MII stage. Despite plenty of research based on the improvement of bitch oocytes in vitro culture, the results obtained are still unsatisfactory. Moreover, in the long stages of canine oocytes maturation many molecular and morphological modifications (including changes in mitochondria structure and configuration in the cytoplasm) are involved. In this article, the influence of selected media supplements on the efficiency of bitch oocytes in vitro maturation was described. The molecular and morphological modifications during canine oocytes maturation were also considered in the text.