Oxidative stress modulation induced by chitosan-glutathione nanoparticles in chondrocytes.

The use of nanometric systems to deliver biologically active substances is a successful tool in different fields. In this study, we investigated nanometric systems with antioxidant capacity to modulate events associated with the redox state in human chondrocytes. We used nanoparticles (NPs) prepared with chitosan and glutathione (GSH) and an in vitro model: primary cultures of human chondrocytes were extracted from hyaline cartilage. The cells were exposed to CdCl2 in the presence or absence of NPs. CdCl2 is a widely known oxidizing agent. Fluorescence and confocal microscopy showed the location of the NPs within the cells. The results obtained showed that the NPs did not significantly affect cell viability. We studied the antioxidant capacity of the NPs by estimating the GSH, TBARs, and Cell Rox content and the enzymatic activity of glutathione peroxidase (GPx). In vitro assays showed that GSH levels, GPx activity and reactive oxygen species (Cell Rox) levels were modified with both concentrations of NPs, while lipoperoxidation (TBARs) decreased when cells exposed to CdCl2 were in contact with the NPs. All these results suggest the ability of NPs to modulate the cell redox state in a dose-dependent manner.

Relative expression analysis of IL-5 and IL-6 genes in tropical sheep breed Pelibuey infected with Haemonchus contortus.

Haemonchus contortus is a parasitic nematode of Pelibuey sheep, a meat breed used in tropical regions. Due to anthelmintic problems, the identification of hosts resistant to H. contortus is another option of control. The aim of this study was to analyse the relative expression of IL-5 and IL-6 genes in Pelibuey sheep after H. contortus infection. Nineteen lambs infected with H. contortus and three more lambs without infection were studied. The haemonchosis was determined by the number of eggs per gram of faeces (epg) and by the estimation of the percentage of the packed cell volume (%pcv). Peripheral blood mononuclear cells (PBMCs) were obtained to extract RNA at 0, 1, 2, 7, 14, 21 and 28 days after infection to quantify the relative expression of IL-5, IL-6 and GAPDH by real-time PCR. Five lambs were classified as low responders (lr) to haemonchosis with averages of 1519 ± 315·3 epg and 31·49 ± 5·13%pcv, and 14 lambs were identified as high responders (hr) with averages of 530 ± 132 epg and 34·88 ± 3·75%pcv. The expression ratio of IL-5 was significantly different compared with control lambs at 2, 7 and 14 days post-infection (PI), and IL-6 was significantly different after 14 days. The highest level of relative expression for IL-5 and IL-6 genes was 9·9-fold and 12-fold after 2 and 14 days for hr hosts (P < 0·05) compared with control group, respectively. In conclusion, the Pelibuey breed in grazing areas exhibited different expression of IL-5 and IL-6 obtained from PBMCs against H. contortus, suggesting the importance of these cytokines in regulating the nematode infection.

Hypoxia-Inducible Factors (HIFs) in the articular cartilage: a systematic review.

Osteoarthritis (OA) is the most common joint disease, and in recent years has become a major public health problem. The hallmark of OA is cartilage destruction with local commitment of subchondral bone and the synovial membrane. Hypoxia-inducible factors (HIFs) are transcriptional factors and key regulators of the cellular response to hypoxia. To date, three members of the human HIF-α protein family have been described: HIF-1α, HIF-2α, and HIF-3α. HIF-1α plays an essential role in the articular cartilage (a hypoxic tissue), as it has a protective effect in the maintenance of the articular cartilage matrix, HIF-2α has a harmful effect on the articular cartilage matrix, and HIF-3α acts as a negative regulator of HIF-1α and HIF-2α. Due to the recent growing interest in the role of HIFs in rheumatic diseases, we focused this review on the potential role of these key regulators in articular cartilage maintenance as the central axis in OA development.