A comprehensive investigation of human endogenous retroviral syncytin proteins and their receptors in men with normozoospermia and impaired semen quality

Dysfunction of DMT1 and miR-135b in the gut-testis axis in high-fat diet male mice

BACKGROUND

Obese patients have been found to be susceptible to iron deficiency, and malabsorption of dietary iron is the cause of obesity-related iron deficiency (ORID). Divalent metal transporter 1 (DMT1) and ferroportin (FPN), are two transmembrane transporter proteins expressed in the duodenum that are closely associated with iron absorption. However, there have been few studies on the association between these two proteins and the increased susceptibility to iron deficiency in obese patients. Chronic inflammation is also thought to be a cause of obesity-related iron deficiency, and both conditions can have an impact on spermatogenesis and impair male reproductive function. Based on previous studies, transgenerational epigenetic inheritance through gametes was observed in obesity.

RESULTS

Our results  showed that obese mice had decreased blood iron levels (p < 0.01), lower protein and mRNA expression for duodenal DMT1 (p < 0.05), but no statistically significant variation in mRNA expression for duodenal FPN (p > 0.05); there was an increase in sperm miR-135b expression (p < 0.05). Bioinformatics revealed ninety overlapping genes and further analysis showed that they were primarily responsible for epithelial cilium movement, fatty acid beta-oxidation, protein dephosphorylation, fertilization, and glutamine transport, which are closely related to spermatogenesis, sperm development, and sperm viability in mice.

CONCLUSIONS

In obese mice, we observed downregulation of DMT1 in the duodenum and upregulation of miR-135b in the spermatozoa.

Acetyl-L-carnitine attenuates chronic ethanol-induced oxidative stress, ER stress and apoptosis in rat gastric tissue

Consuming alcohol affects almost all organs. Acetaldehyde, formed as the main product as a result of alcohol metabolism, causes the production of free superoxide radicals when oxidized, and accordingly oxidative and apoptotic processes are triggered. There are studies showing that carnitine has effects on oxidative and apoptotic processes that occur in various conditions. However, the mechanisms showing the effects of L-carnitine on these effects of alcohol have not been fully elucidated. In our study, the effects of acetyl-L-carnitine administration on the molecular mechanisms of oxidative stress, endoplasmic reticulum stress, and apoptotic parameters in gastric tissue of rats chronically exposed to alcohol were investigated. Hematoxylin-eosin staining was used for histopathological studies. Endoplasmic reticulum stress markers were detected with immunohistochemical staining and western blotting. Apoptotic index was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. Total oxidant and antioxidant status were examined by ELISA. Our results showed that chronic alcohol administration caused a significant increase in TOS levels, an indicator of oxidative stress, the levels of ER-stress-associated proteins XBP1, GRP78, and CHOP, and % apoptotic index values in rat gastric tissues. Additionally, it was determined that acetyl-L-carnitine administration caused an improvement in those values. Based on our data, we can conclude that acetyl-L-carnitine has a tissue protective effect by scavenging free oxygen radicals and reducing ER stress-related proteins XBP1, GRP78, and CHOP and apoptosis in chronic ethanol-administered rats, and that this natural antioxidant may be beneficial in the treatment of oxidative stress-induced diseases.

Molecular mechanisms of syncytin-1 in tumors and placental development related diseases

Human endogenous retroviruses (HERVs) have evolved from exogenous retroviruses and account for approximately 8% of the human genome. A growing number of findings suggest that the abnormal expression of HERV genes is associated with schizophrenia, multiple sclerosis, endometriosis, breast cancer, bladder cancer and other diseases. HERV-W env (syncytin-1) is a membrane glycoprotein which plays an important role in placental development. It includes embryo implantation, fusion of syncytiotrophoblasts and of fertilized eggs, and immune response. The abnormal expression of syncytin-1 is related to placental development-related diseases such as preeclampsia, infertility, and intrauterine growth restriction, as well as tumors such as neuroblastoma, endometrial cancer, and endometriosis. This review mainly focused on the molecular interactions of syncytin-1 in placental development-related diseases and tumors, to explore whether syncytin-1 can be an emerging biological marker and potential therapeutic target.