OUP accepted manuscript

Possible protective effects of vanillin against stress-induced seminiferous tubule injury via modulation of Nrf2 and ZO1

Around 20% of the human population is distressed. Previous studies have looked into the relationship between restraint immobilization stress (IS) and sexual behavior in male rats. The current study aimed to provide a brief explanation of the mechanisms that generated testicular injury with chronic IS and an attempt to evaluate the mechanisms and effects of vanillin as a novel protective agent. Forty-eight adult male albino rats were divided into six groups: control, vanillin-treated, chronic 2-h IS, 2-h stressed-vanillin-treated, chronic 6-h IS, and 6-h stressed-vanillin treated. The rats were sacrificed, and blood samples were collected for biochemical study. The testes were processed for biochemical and histological study, as well as histological Johnsen score. The results showed that prolonged IS increased both corticosterone and TNF-α levels as well as decreased testosterone, luteinizing hormone, catalase, and Nrf2 levels. This effect was more pronounced after 6 h of IS compared to 2 h. It also induced various testicular injuries with weak ZO-1 and CD34 immunoreactions. On the contrary, vanillin improved all mentioned biochemical and histological alternations induced by stress. Additionally, computational molecular docking analyses were conducted on the compound vanillin within the active site of Zona Occludens-1 (PDB ID: 2JWE). The results demonstrated remarkable docking scores and binding affinity, corroborating its potential protective efficacy. It could be concluded that vanillin is a promising treatment alternative for protecting testicular tissue from the harmful effects of IS via its antioxidant and anti-inflammatory properties.

Could the Effect of Arsenic on the Testis be Reversed after Removing the Insult? A Meta-analysis Study

Arsenic in drinking water has been associated with an increased risk of health concerns. This metalloid is ingested and distributed throughout the body, accumulating in several organs, including the testis. In this organ, arsenic disturbs steroidogenesis and spermatogenesis and affects male fertility. Although testicular impairment induced by arsenic is well documented, it is still controversial whether such disturbance remains days after the removal of arsenic insult. Therefore, we used a meta-analytical approach to evaluate the magnitude of arsenic effects on testicular parameters and verify whether a withdrawal period can mitigate these alterations. The search terms 'testis" and 'arsenic' were used in PubMed/Medline, Scopus, and Web of Science databases. A total of 1,217 articles were obtained from the literature search, and 73 articles were included in this meta-analysis. Our results showed that arsenic negatively affected hormone synthesis and secretion, testicular weight, tubular and intertubular morphometry, and daily sperm production 24 h after ending exposure. Arsenic inhibited antioxidant enzyme activity, culminating in high oxidative metabolite production and apoptosis occurrence. Most of these effects were not observed in the testis between eight and fifty days after arsenic withdrawal, remaining endocrine dysregulation and oxidative metabolite production. Sodium arsenite was the most toxic compound to the testis at subchronic exposure. These findings shed light on the plasticity and regenerative capacity of testicular interstitium and spermatogonial stem cell niche. However, sexual hormone imbalance remained after arsenic removal. This review evidenced the importance of understanding its toxicity's short- and long-term effects on male reproductive competence.

Novel findings from arsenic‑lead combined exposure in mouse testicular TM4 Sertoli cells based on transcriptomics

Arsenic (As) and lead (Pb) exist widespread in daily life, and they are common harmful substances in the environment. As and Pb pollute the environment more often in combination than in isolation. The TM4 Sertoli cell line is one of the most common normal mouse testicular Sertoli cell lines. In vitro, we found that the type of combined action of As and Pb on TM4 Sertoli cells was additive action by using the isobologram analysis. To further investigate the combined toxicity of As and Pb, we performed mRNA and miRNA sequencing on TM4 Sertoli cells exposed to As alone (4 μM NaAsO2) and AsPb combined (4 μM NaAsO2 and 150 μM PbAc), respectively. Compared with the control group, 1391 differentially expressed genes (DEGs) and 6 differentially expressed miRNAs (DEMs) were identified in the As group. Compared with the control group, 2384 DEGs and 44 DEMs were identified in the AsPb group. Compared with the As group, 387 DEGs and 4 DEMs were identified in the AsPb group. Through data analysis, we discovered for the first time that As caused the dysfunction of cholesterol synthesis and energy metabolism, and disrupted cyclic adenosine monophosphate signaling pathway and wingless/integrated (Wnt) signaling pathway in TM4 Sertoli cells. In addition to affecting cholesterol synthesis and energy metabolism, AsPb combined exposure also up-regulated the antioxidant reaction level of TM4 Sertoli cells. Meanwhile, the Wnt signaling pathway of TM4 Sertoli cells was relatively normal when exposed to AsPb. In conclusion, at the transcription level, the combined action of AsPb is not merely additive effect, but involves synergistic and antagonistic effects. The new discovery of the joint toxic mechanism of As and Pb breaks the stereotype of the combined action and provides a good theoretical basis and research clue for future study of the combined-exposure of harmful materials.