The non-canonical bivalent gene Wfdc15a controls spermatogenic protease and immune homeostasis.

Male infertility can be caused by chromosomal abnormalities, mutations and epigenetic defects. Epigenetic modifiers pre-program hundreds of spermatogenic genes in spermatogonial stem cells (SSCs) for expression later in spermatids, but it remains mostly unclear whether and how those genes are involved in fertility. Here, we report that Wfdc15a, a WFDC family protease inhibitor pre-programmed by KMT2B, is essential for spermatogenesis. We found that Wfdc15a is a non-canonical bivalent gene carrying both H3K4me3 and facultative H3K9me3 in SSCs, but is later activated along with the loss of H3K9me3 and acquisition of H3K27ac during meiosis. We show that WFDC15A deficiency causes defective spermiogenesis at the beginning of spermatid elongation. Notably, depletion of WFDC15A causes substantial disturbance of the testicular protease-antiprotease network and leads to an orchitis-like inflammatory response associated with TNFα expression in round spermatids. Together, our results reveal a unique epigenetic program regulating innate immunity crucial for fertility.

Tsga8 is required for spermatid morphogenesis and male fertility in mice.

During spermatogenesis, intricate gene expression is coordinately regulated by epigenetic modifiers, which are required for differentiation of spermatogonial stem cells (SSCs) contained among undifferentiated spermatogonia. We have previously found that KMT2B conveys H3K4me3 at bivalent and monovalent promoters in undifferentiated spermatogonia. Because these genes are expressed late in spermatogenesis or during embryogenesis, we expect that many of them are potentially programmed by KMT2B for future expression. Here, we show that one of the genes targeted by KMT2B, Tsga8, plays an essential role in spermatid morphogenesis. Loss of Tsga8 in mice leads to male infertility associated with abnormal chromosomal distribution in round spermatids, malformation of elongating spermatid heads and spermiation failure. Tsga8 depletion leads to dysregulation of thousands of genes, including the X-chromosome genes that are reactivated in spermatids, and insufficient nuclear condensation accompanied by reductions of TNP1 and PRM1, key factors for histone-to-protamine transition. Intracytoplasmic sperm injection (ICSI) of spermatids rescued the infertility phenotype, suggesting competency of the spermatid genome for fertilization. Thus, Tsga8 is a KMT2B target that is vitally necessary for spermiogenesis and fertility.

[A Case of Stage IV Gastric Cancer Successfully Treated Using Salvage Surgery after S-1/CDDP Therapy].

A 75-year-old man admitted for left lateral abdominal pain was found to have advanced poorly differentiated gastric adenocarcinoma with abdominal para-aortic and Virchow's lymph node metastases, which was diagnosed to be clinical Stage IV (T3N3H0M1[LYM]). As curative surgery was not deemed possible, we started chemotherapy administration using S-1 (120mg/day)administered orally for 3 weeks and cisplatin(CDDP 100mg/body)administered intravenously on day 8. After 6 courses of chemotherapy, a CT scan showed that all lymph nodes metastases had disappeared, resulting in downstaging to clinical Stage II (T3[SE]N0H0P0M0). Thus, we performed total gastrectomy, lymph node dissection(D2), and splenectomy. Histological findings showed no residual tumor cells in any of the lymph nodes. However, cancer cells remained in the primary gastric lesion. The pathological response to chemotherapy was judged to be Grade 2. The patient has been recurrence-free for 5 years after surgery.