PIWI proteins play important roles in germline development in the mammals. However, the functions of PIWIs in crustaceans remain unknown. In the present study, we identified three Piwis from the testis of Eriocheir sinensis (E. sinensis). Three Piwi genes encoded proteins with typical features of PIWI subfamilies and were highly expressed in the testis. Three PIWIs could be detected in the cytoplasm of spermatocytes and spermatids, while in spermatozoa, we could only detect PIWI1 and PIWI3 in the nucleus. The knockdown of PIWIs by dsRNA significantly affected the formation of the nuclei in spermatozoa, which resulted in deviant and irregular nuclei. PIWI defects significantly inhibited the apoptosis of abnormal germ cells through the caspase-dependent apoptosis pathway and p53 pathway. Knockdown of PIWIs inhibited the expression of caspase3, 7, 8, and p53 without affecting Bcl2 (B-cell lymphoma gene 2), Bax (B-cell lymphoma-2-associated X) and BaxI (B-cell lymphoma-2-associated X inhibitor), which further significantly increased abnormal spermatozoa in the knockdown-group crabs. These results show a new role of PIWI proteins in crustaceans that is different from that in mammals. In summary, PIWIs play roles in the formation of the germline nucleus and can maintain apoptosis in abnormal germ cells to remove abnormal germ cells in E. sinensis.
Bang-Hong Wei, Jia-Hao Ni, Tong Yang, Shuang-Li Hao, and Wan-Xi Yang
Tong Sun, Shi-Jie Li, Hong-Lu Diao, Chun-Bo Teng, Hong-Bin Wang, and Zeng-Ming Yang
Cyclooxygenase (COX), a rate-limiting enzyme that produces prostaglandins (PGs) from arachidonic acid, exists in two isoforms, COX-1 and COX-2. PGE2 synthase (PGES) is a terminal prostanoid synthase and can enzymatically convert the cyclooxygenase product PGH2 to PGE2, including two isoforms: microsomal PGES (mPGES) and cytosolic PGES (cPGES). cPGES is predominantly linked with COX-1 to promote the immediate response. mPGES is preferentially coupled with the inducible COX-2 to promote delayed PGE2 generation. COX-2-deficient female mice are infertile with abnormalities in ovulation, fertilization, implantation and decidualization. The aim of this study was to examine immunohistochemically the expression pattern of COX-1, COX-2, mPGES and cPGES proteins in the endometrium of the rhesus monkey during the menstrual cycle. COX-1 immunostaining was mainly localized in the luminal epithelium and glandular epithelium near the lumen, and detected in all the stages during the menstrual cycle. COX-2 immunostaining was mainly localized in the luminal and glandular epithelium, and strongly shown during the mid-luteal phase (days 16 and 20) of the menstrual cycle. There was a strong cPGES immunostaining in the luminal and glandular epithelium on days 12, 16, 20 and 25 of the menstrual cycle. mPGES immunostaining was strongly detected in the glandular epithelium on days 20 and 25 of the menstrual cycle. These data suggest that the coupling of cPGES and COX-1 in the luminal epithelium may be responsible for the synthesis of PGE2 in monkey endometrium, and the coupling of mPGES and COX-2 in the glandular epithelium may be of importance for preparing the receptive endometrium.
Xuan-Tong Liu, Hui-Ting Sun, Zhong-Fang Zhang, Ru-Xia Shi, Li-Bing Liu, Jia-Jun Yu, Wen-Jie Zhou, Chun-Jie Gu, Shao-Liang Yang, Yu-Kai Liu, Hui-Li Yang, Feng-Xuan Xu, and Ming-Qing Li
It has been reported that the impaired cytotoxicity of natural killer (NK) cells and abnormal cytokines that are changed by the interaction between ectopic endometrial cells and immune cells is indispensable for the initiation and development of endometriosis (EMS). However, the mechanism of NK cells dysfunction in EMS remains largely unclear. Here, we found that NK cells in peritoneal fluid from women with EMS highly expressed indoleamine 2,3-dioxygenase (IDO). Furthermore, IDO+NK cells possessed lower NKp46 and NKG2D but higher IL-10 than that of IDO-NK. Co-culture with endometrial stromal cells (nESCs) from healthy control or ectopic ESCs (eESCs) from women with EMS led to a significant increase in the IDO level in NK cells from peripheral blood, particularly eESCs, and an anti-TGF-β neutralizing antibody suppressed these effects in vitro. NK cells co-cultured with ESC more preferentially inhibited the viability of nESCs than eESCs did, and pretreating with 1-methyl-tryptophan (1-MT), an IDO inhibitor, reversed the inhibitory effect of NK cells on eESC viability. These data suggest that ESCs induce IDO+NK cells differentiation partly by TGF-β and that IDO further restricts the cytotoxicity of NK cells in response to eESCs, which provides a potential therapeutic strategy for EMS patients, particularly those with a high number of impaired cytotoxic IDO+NK cells.