Cloning, characterization, and expression analysis of goat (Capra hircus) phospholipid hydroperoxide glutathione peroxidase (PHGPx)

Function and regulation of GPX4 in the development and progression of fibrotic disease

Fibrosis is a common feature of fibrotic diseases that poses a serious threat to global health due to high morbidity and mortality in developing countries. There exist some chemical compounds and biomolecules associated with the development of fibrosis, including cytokines, hormones, and enzymes. Among them, glutathione peroxidase 4 (GPX4), as a selenoprotein antioxidant enzyme, is widely found in the embryo, testis, brain, liver, heart, and photoreceptor cells. Moreover, it is shown that GPX4 elicits diverse biological functions by suppressing phospholipid hydroperoxide at the expense of decreased glutathione (GSH), including loss of neurons, autophagy, cell repair, inflammation, ferroptosis, apoptosis, and oxidative stress. Interestingly, these processes are intimately related to the occurrence of fibrotic disease. Recently, GPX4 has been reported to exhibit a decline in fibrotic disease and inhibit fibrosis, suggesting that alterations of GPX4 can change the course or dictate the outcome of fibrotic disease. In this review, we summarize the role and underlying mechanisms of GPX4 in fibrosis diseases such as lung fibrosis, liver fibrosis, kidney fibrosis, cardiac fibrosis, and myelofibrosis.

Dietary supplementation of nano-selenium improves reproductive performance, sexual behavior and deposition of selenium in the testis and ovary of Japanese quail

Objective

Selenium (Se), as the form of selenite, is commonly supplemented in poultry diet, which has low bioavailability and high toxicity. Here, we compared the effects of the supplementation of the diet with Se nanoparticles (nano-Se) on the growth, sexual behavior, and reproductive performance (gonad size, sperm quality traits, and plasma testosterone levels for males and egg production for females) of Japanese quail (Coturnix coturnix japonica).

Materials and Methods

Quail chicks (n = 300) aging 14 days were divided into three groups: Group 1 (basal diet and Se at 0.2 mg/kg ration), Group 2 (basal diet and nano-Se at 0.2 mg/kg ration), and Group 3 (basal diet and nano-Se at 0.1 mg/kg ration). Several parameters relating to body weight and egg were measured. Sexual behaviors of the birds were observed by continuous visual scanning. The sperm viability, sperm morphology, and concentration of spermatozoa were determined after staining and microscopic examination. The plasma testosterone levels were determined by indirect enzyme immunoassay assay. The Se concentrations in the testicular, ovarian, and ration samples were measured by flame emission atomic absorption spectrophotometer.

Results

The type or concentration of nano-Se administration had no impact on body weight, feed efficiency, egg production, or egg weight. However, the total feed intake throughout the experiment was reduced in Group 2 at 0.2 mg/kg. Nano-Se supplementation significantly increased the sexual behavior. In general, the deposition of Se in the testicular and ovarian tissues increased with increasing supplement concentration. At the same supplement concentration, the tissue deposition of nano-Se was more enhanced than that of inorganic Se. Nano-Se supplementation improved the testicular functions by enhancing plasma testosterone level and sperm quality traits (sperm count, motility, and viability). This improvement was found more prominent with the lower supplement concentration (when comparing 0.1 vs. 0.2 mg/kg diet).

Conclusion

It is concluded that the use of nano-Se (at 0.1 mg/kg) in the ration of Japanese quail improves several reproductive performance parameters.

Cloning and characterization of PHGPx and its synergistic role with p53 in mediating stress in Penaeus monodon

Phospholipid-hydroperoxide glutathione peroxidase (PHGPx), a ubiquitous antioxidant enzyme in the glutathione peroxidase (GPx) family, plays multiple roles in different organisms. Here, a novel PHGPx (PmPHGPx) was identified from Penaeus monodon. The full-length PmPHGPx cDNA was 1885 bp in length with a 489-bp open reading frame (ORF) containing a selenocysteine codon, TGA^177-179, and a selenocysteine insertion sequence in the 3'-UTR. The typical signature motifs of the GPx family were also detected in the PmPHGPx amino acid sequence. The PmPHGPx expression pattern showed tissue-specific variations, with the highest expression level in the heart and the lowest expression level in the muscle. To examine the relationship between Pmp53 and PmPHGPx, Pmp53 was successfully silenced with a dsRNA-p53 injection, and an obvious down-regulation in PmPHGPx expression was apparent. To clarify the functional roles of Pmp53 and PmPHGPx, their expression patterns were also assessed after pH-induced stress, salinity stress and heavy metal (Cu, Zn, and Cd) challenges. Similar trends in the expression profiles for PmPHGPx and Pmp53 were detected in both the gills and hepatopancreas in response to all stressors. Therefore, we conclude from the results that PmPHGPx acts synergistically and subsequently works cooperatively with Pmp53 toward mediating cell stress. This study improves our understanding of PmPHGPx and its synergistic role with Pmp53 in counteracting stressors in P. monodon.