Yttrium nitrate activates the oxidative stress-mediated NF-κB pathway to induce testicular inflammatory response and reduce sperm quality in mice.

The rising environmental levels of yttrium have sparked concerns regarding its possible health hazards. Nevertheless, limited toxicological data are available to determine yttrium's toxicity and potential mechanisms on sperm. In our research, the action of oxidative stress and the NF-κB pathway on decreased sperm quality and testicular inflammatory reaction induced by yttrium exposure was analyzed. Yttrium nitrate (YN), N-Acetyl Cysteine (NAC), and JSH-23 were used to intervene in mice and cells in vivo and in vitro experiments. Eosin-nigrosine staining, in vitro fertilization, Annexin V-FITC/PI staining, ICP-MS, Hematoxylin-eosin staining, RT-qPCR, DCFH-DA staining, biochemical methods, ELISA, and western blot were applied to detect sperm motility, fertilizing capacity, apoptosis, Y3+ accumulation, testicular structure, testicular function, and NF-κB gene expression, ROS, MDA, GSH, pro-inflammatory cytokines, and NF-κB protein expression, respectively. The results revealed that YN exposure reduced sperm motility, increased sperm apoptosis, disrupted testicular tissue structure and function in mice. Exposure to YN increased ROS content and NF-κB pathway activation in testicular tissue and cells, resulting in upregulation of pro-inflammatory cytokines in the testis. When NAC scavenged ROS, the YN-induced sperm damage and inflammatory reaction, and NF-κB pathway abnormal activation in the testis of mice were alleviated. In addition, sperm damage and testicular inflammatory reaction caused by YN were alleviated after blocking the NF-κB pathway with JSH-23 treatment. Our present study elucidated that YN could damage sperm quality and induce testicular inflammatory reaction, establishing YN's toxicological impact on the male reproductive system.