Sex Differences in the Effect of Resveratrol on DSS-Induced Colitis in Mice.

Resveratrol is a natural polyphenol studied for its possible protective properties in inflammatory bowel diseases. Moreover, it has been shown to interact with estrogen receptors. In the present study, we aimed to investigate possible diverse effects of resveratrol on female and male mice in DSS-induced colitis. Thirty-seven C57BL/6 mice (21 female and 16 male) were divided into three groups for each sex. The first group received pure water (CTRL). The other two groups received 1.5% dextran sulfate sodium (DSS) to induce colitis from which one group was treated with resveratrol (DSS + RSV). Intake of 1.5% DSS caused weight loss in all DSS groups compared to control mice. Weight loss, stool consistency, and discomfort did not show any protective effect of resveratrol in males and showed even adverse effects in females. In females, the activity of myeloperoxidase was lower compared to that in males. However, colon length and spleen weight showed no sex differences, which can indicate the induction of only mild colitis in mice. Resveratrol did not have any effect on TNF-alpha levels. Taken together, these results for the first time propose possible diverse effects of resveratrol in DSS-induced colitis model depending on the sex of the animal. However, this conclusion must be confirmed by further analyses.

Keratins are novel markers of renal epithelial cell injury.

Keratins, the intermediate filaments of the epithelial cell cytoskeleton, are up-regulated and post-translationally modified in stress situations. Renal tubular epithelial cell stress is a common finding in progressive kidney diseases, but little is known about keratin expression and phosphorylation. Here, we comprehensively describe keratin expression in healthy and diseased kidneys. In healthy mice, the major renal keratins, K7, K8, K18, and K19, were expressed in the collecting ducts and K8, K18 in the glomerular parietal epithelial cells. Tubular expression of all 4 keratins increased by 20- to 40-fold in 5 different models of renal tubular injury as assessed by immunohistochemistry, Western blot, and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The up-regulation became significant early after disease induction, increased with disease progression, was found de novo in distal tubules and was accompanied by altered subcellular localization. Phosphorylation of K8 and K18 increased under stress. In humans, injured tubules also exhibited increased keratin expression. Urinary K18 was only detected in mice and patients with tubular cell injury. Keratins labeled glomerular parietal epithelial cells forming crescents in patients and animals. Thus, all 4 major renal keratins are significantly, early, and progressively up-regulated upon tubular injury regardless of the underlying disease and may be novel sensitive markers of renal tubular cell stress.

No harmful effect of different Coca-cola beverages after 6 months of intake on rat testes.

Our laboratory recently reported that a 3-month exposure of rats to cola-like beverages induced sex hormone changes. The aim of the study was to investigate the effects of various types of Coca-cola intake with different composition for 6 months on oxidative status in testes and testosterone in adult male rats. Fifty adult male Wistar rats were divided into control group drinking water, and groups drinking different Coca-cola beverages (regular Coca-cola, Coca-cola caffeine-free, Coca-cola Light and Coca-cola Zero). Oxidative and carbonyl stress markers were measured in the testicular tissue to assess oxidative status together with testicular and plasma testosterone. StAR expression in testes as a marker of steroidogenesis was quantified. No significant differences were found between the groups in any of the measured parameters. In conclusion, oxidative and carbonyl stress in testicular tissue were not influenced by drinking any type of Coca-cola. Additionally, testosterone in testes and in plasma, as well as testicular StAR expression were comparable among the groups.