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.

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

PURPOSE: The study aims to investigate first the presence of Syncytin 2 and its receptor, MFSD2, in human sperm, and second whether the expressions of Syncytin 1, Syncytin 2, and their receptors, SLC1A5 and MFSD2, differ between normozoospermic, asthenozoospermic, oligozoospermic, and oligoasthenozoospermic human sperm samples. METHODS: The localization patterns and expression levels of syncytins and their receptors were evaluated in normozoospermic (concentration = 88.9 ± 5.5 × 106, motility = 79.2 ± 3.15%, n = 30), asthenozoospermic (concentration = 51.7 ± 7.18 × 106, motility = 24.0 ± 3.12%, n = 15), mild oligozoospermic (concentration = 13.5 ± 2.17 × 106, motility = 72.1 ± 6.5%, n = 15), moderate oligozoospermic (concentration = 8.4 ± 3.21 × 106, motility = 65.1 ± 8.9%, n = 15), severe oligozoospermic (concentration = 2.1 ± 1.01 × 106, motility = 67.5 ± 3.2%, n = 15), and oligoasthenozoospermic (concentration = 5.5 ± 3.21 × 106, motility = 18.5 ± 1.2%, n = 15) samples by immunofluorescence staining and western blot. RESULTS: Syncytins and their receptors visualized by immunofluorescence showed similar staining patterns with slight staining of the tail in all spermatozoa regardless of normozoospermia, asthenozoospermia, oligozoospermia, or oligoasthenozoospermia. The localization patterns were categorized as equatorial segment, midpiece region, acrosome, and post-acrosomal areas. The combined staining patterns were also detected as acrosomal cap plus post acrosomal region, the midpiece plus equatorial segment, and midpiece plus acrosomal region. However, some sperm cells were categorized as non-stained. Both syncytin proteins were most intensely localized in the midpiece region, while their receptors were predominantly present in the midpiece plus acrosomal region. Conspicuously, syncytins and their receptors showed decreased expression in asthenozospermic, oligozoospermic, and oligoasthenozoospermic samples compared to normozoospermic samples. CONCLUSION: The expression patterns of HERV-derived syncytins and their receptors were identical regardless of the spermatozoa in men with normozoospermia versus impaired semen quality. Further, asthenozoospermia, oligozoospermia, and oligoasthenozoospermia as male fertility issues are associated with decreased expression of both syncytins and their receptors.

Acute and Chronic Exposure to 900 MHz Radio Frequency Radiation Activates p38/JNK-mediated MAPK Pathway in Rat Testis.

The use of electronic devices such as mobile phones has had a long stretch of rapid growth all over the world. Therefore, exposure to radio frequency radiation (RFR) has increased enormously. Here, we aimed to assess the balance between cell death and proliferation and also investigate the involvement of the JNK/p38 MAPK signaling pathway in the testis of rats exposed to 900 MHz RFR in acute and chronic periods (2 h/day, 5 days/week) for 1 or 10 weeks, respectively. The expression of proliferating cell nuclear antigen (PCNA), Bcl-xL, cleaved caspase-3, phosphorylated-JNK (p-JNK), and phosphorylated-p38 (p-p38) was analyzed in line with histopathology and TUNEL analysis in rat testis. There were no histopathological differences between sham and RFR groups in the acute and chronic groups. PCNA expression was not altered between groups in both periods. However, alterations for cleaved caspase-3 and Bcl-xL were observed depending on the exposure period. TUNEL analysis showed a significant increase in the RFR group in the acute period, whereas no difference in the chronic groups for the apoptotic index was reported. In addition, both p-p38 and p-JNK protein expressions increased significantly in RFR groups in both periods. Our study indicated that 900 MHz RFR might result in alterations during acute period exposure for several parameters, but this can be ameliorated in the chronic period in rat testis. Here, we also report the involvement of the p38/JNK-mediated MAPK pathway after exposure to 900 MHz RFR. Hence, this information might shed light in future studies toward detailed molecular mechanisms in male reproduction and infertility.