Polycystic ovary syndrome (PCOS) is a common endocrine disorder accompanied by chronic low-grade inflammation; its etiology is still undefined. This study investigated the expression of CXCL12, CXCR4, and CXCR7 in PCOS rats and their role in regulation of apoptosis. To accomplish this, we established an in vivo PCOS rat model and studied KGN cells (human ovarian granulosa cell line) in vitro. In PCOS rats, the ovarian expression of CXCL12, CXCR4, and CXCR7 was reduced, and the apoptosis rate of granulosa cells was increased, accompanied by decreased expression of BCL2 and increased expression of BAX and cleaved CASPASE3 (CASP3). We further showed that recombinant human CXCL12 treatment upregulated BCL2, downregulated BAX, and cleaved CASP3 in KGN cells to inhibit their apoptosis in a concentration-dependent manner; moreover, the effect of CXCL12 was weakened by CXCR4 antagonist AMD3100 and anti-CXCR7 neutralizing antibody. In conclusion, PCOS rats showed decreased CXCL12, CXCR4, and CXCR7 expression and increased apoptosis rate of ovarian granulosa cells. Further, in human KGN cells, CXCL12 regulated the expression of BAX, BCL2, and cleaved CASP3 to inhibit apoptosis through CXCR4- and CXCR7-mediated signal transmission. These findings may provide a theoretical and practical basis for illuminating the role of proinflammatory cytokines in the pathogenesis of PCOS.
Ling Jin, Liang Ren, Jing Lu, Xue Wen, Siying Zhuang, Ting Geng, and Yuanzhen Zhang
Yingying Zhou, Yangying Peng, Qingqing Xia, Dewen Yan, Huiping Zhang, Lingmin Zhang, Ying Chen, Xiumin Zhao, and Jie Li
Indian hedgehog (Ihh) signaling regulates endometrial receptivity and is an indispensable mediator of embryonic implantation. Hedgehog signaling is known to regulate autophagy, and aberrant regulation of autophagy is critically implicated in the pathogenesis of endometriosis and adenomyosis. However, potential dysregulation of Ihh signaling and its role in autophagy modulation in these diseases remain obscure. In this study, we found that components of Ihh signaling were significantly decreased, whereas the autophagy marker protein, LC3BII, was significantly increased in endometrial tissues of women with endometriosis or adenomyosis. Inhibition of Ihh signaling with the small-molecule inhibitor GANT61 or Gli1 silencing in primary endometrial stromal cells increased autophagic activity, as measured by LC3 turnover assay and tandem mCherry-eGFP-LC3B fluorescence microscopy. Furthermore, we observed that GANT61 treatment significantly attenuated hydrogen peroxide-induced cell death, whereas disruption of autophagy with chloroquine diminished this effect. Collectively, these findings reveal that Ihh signaling is suppressed in endometrial tissues of patients with endometriosis or adenomyosis. This abnormal decrease may contribute to endometrial autophagy activation, which may promote aberrant survival of endometrial cells in ectopic sites in these two gynecological diseases.
Yu Tian and Li-quan Zhou
Invasion or damage of the male reproductive system is one of the reported outcomes of viral infection. Current studies have documented that SARS-CoV-2, which causes COVID-19, can damage the male reproductive system in large part by inflammatory damage caused by a cytokine storm. However, whether SARS-CoV-2 can infect the human testis directly and enter semen is controversial. Other adverse effects of SARS-CoV-2 on male reproduction are also of concern and require comprehensive evaluation. Here, we analyze the invasiveness of SARS-CoV-2 in the testis and examine reported mechanisms by which SARS-CoV-2 interferes with male reproduction. Long-term implications of SARS-CoV-2 infection on male reproduction are also discussed. It should be emphasized that although COVID-19 may induce testicular damage, a substantial decrease in male reproductive capacity awaits clinical evidence. We propose that there is an urgent need to track male COVID-19 patients during their recovery. The development of suitable experimental models, including human reproductive organoids, will be valuable to further investigate the viral impact on reproduction for current and future pandemics.
Madhulika Pathak, Venkatappa Vani, Surendra Sharma, and Polani B Seshagiri
Mammalian blastocyst hatching is a critically indispensable process for successful implantation. One of the major challenges in IVF clinics is to achieve superior embryonic development with intrinsically potent hatching-competent blastocyst. However, the molecular regulation of hatching phenomenon is poorly understood. In this study, we examined the expression and function of one of the cytokines, IL-1β during blastocyst hatching in the mouse. In particular, the expression of IL-1β (Interleukin-1β), IL-1ra (Interleukin-1 receptor antagonist) and their functional receptor IL-1rt1 (Interleukin 1 receptor type-1) in morulae, zona intact- and hatched-blastocysts was studied. Supplementation of IL-1β to cultured embryos accelerated blastocyst development with improved hatching (treated: 89.6 ± 3.6% vs untreated: 65.4 ± 4.1%). When embryos were treated with IL-1ra, blastocyst hatching was decreased (treated: 28.8 ± 3.1% vs untreated: 67.5 ± 3.8%). Moreover, IL-1β and IL-1ra influenced the expression of hatching enzymes viz., implantation serine proteases (ISP1 and ISP2). While IL-1β increased the embryonic mRNA expression of ISPs (Isp1: 2–4; Isp2: 9- to 11-fold), IL-1ra decreased expression. The protein localization studies revealed increased nuclear presence predominantly of ISP 2 in IL-1β-treated blastocysts. This is the first report to show the functional significance of embryonic IL-1β in regulating hatching-associated proteases, particularly ISP2. These findings have implications in our understanding of molecular regulation of blastocyst hatching and implantation failure in other species including humans.
Xiaoxu Chen, Qian Sun, Yi Zheng, Zidong Liu, Xiangqian Meng, Wenxian Zeng, and Hongzhao Lu
Infertility caused by male factors is routinely diagnosed by assessing traditional semen parameters. Growing evidence has indicated that the tsRNAs carried in sperm act as epigenetic factors and potential biomarkers for the assessment of sperm quality. We recently demonstrated that tRNAGln-TTG derived small RNAs played notable roles in the first cleavage of a porcine embryo. However, the function of human sperm tRNAGln-TTG derived small RNAs as a diagnostic biomarker and its role in early embryo development remains unclear. In this study, we found that human sperm tRNAGln-TTG derived small RNAs were highly associated with sperm quality. By microinjecting the antisense sequence into human tripronuclear (3PN) zygotes followed by single-cell RNA-sequencing, we found that human sperm tRNAGln-TTG derived small RNAs participated in the development of a human embryo. Furthermore, Gln-TTGs might influence embryonic genome activation by modulating noncoding RNA processing. These findings demonstrated that human sperm tRNAGln-TTG derived small RNAs could be potential diagnostic biomarkers and could be used as a clinical target for male infertility.
K Grace Foley, Michele T Pritchard, and Francesca E Duncan
Inflammaging is a state of chronic, low-grade inflammation associated with aging which contributes to age-related diseases. Recently, an age-associated increase in inflammation has been documented in the mammalian ovary, which is accompanied by a shift in the immune cell profile. In this Point of View article, we consider a unique population of macrophage-derived multinucleated giant cells, found in reproductively old mouse ovaries, as potential markers or functional drivers of inflammation in ovarian aging.
Leelabati Biswas, Katarzyna Tyc, Warif El Yakoubi, Katie Morgan, Jinchuan Xing, and Karen Schindler
Idiopathic or ‘unexplained’ infertility represents as many as 30% of infertility cases worldwide. Conception, implantation, and term delivery of developmentally healthy infants require chromosomally normal (euploid) eggs and sperm. The crux of euploid egg production is error-free meiosis. Pathologic genetic variants dysregulate meiotic processes that occur during prophase I, meiotic resumption, chromosome segregation, and in cell cycle regulation. This dysregulation can result in chromosomally abnormal (aneuploid) eggs. In turn, egg aneuploidy leads to a broad range of clinical infertility phenotypes, including primary ovarian insufficiency and early menopause, egg fertilization failure and embryonic developmental arrest, or recurrent pregnancy loss. Therefore, maternal genetic variants are emerging as infertility biomarkers, which could allow informed reproductive decision-making. Here, we select and deeply examine human genetic variants that likely cause dysregulation of critical meiotic processes in 14 female infertility-associated genes: SYCP3, SYCE1, TRIP13, PSMC3IP, DMC1, MCM8, MCM9, STAG3, PATL2, TUBB8, CEP120, AURKB, AURKC, andWEE2. We discuss the function of each gene in meiosis, explore genotype-phenotype relationships, and delineate the frequencies of infertility-associated variants.
Daqian Dong, Jinmeng Yang, Yining Chen, Guofan Peng, Heran Cao, Huihui Gao, Tianqi Jin, Fangxia Yang, and Wuzi Dong
Epididymal specific proteins play a crucial role in sperm maturation. Some of the post-translational modified proteins are transported from the caput to the cauda of the epididymis through exosomes which regulate the function of sperm in cauda epididymis. Rat beta-galactosidase-1-like protein 4 (GLB1L4) expressed specifically in the caput epididymis, localizes on the sperm; however, the regulatory ways in which GLB1L4 protein interacts with sperm to maintain sperm function are unclear. In this study, knockdown of rat GLB1L4 could inhibit in vitro capacitation of sperm in cauda epididymis and reduce the fertility of the male rats by injection of special lentivirus-shRNA into caput epididymis. Moreover, a considerable proportion of GLB1L4 proteins from rat caput epididymis were loaded on exosomes. The exosomes loaded GLB1L4 from in vitro primary rat caput epididymal epithelial cells could bind with spermatozoa in cauda epididymis. Further, the palmitoylation status of cysteine residues at the 12th and 15th sites of the protein molecule could significantly affect cellular localization of GLB1L4 protein. It was identified that most of GLB1L4 was palmitoylated in the presence of exosomes from primary caput epididymal cells and the level of palmitoylated GLB1L4 in the exosomes could be inhibited by 2-bromopalmitate (2-BP). These results suggested that the palmitoylated GLB1L4 from rat caput epididymis could be transported to the cauda epididymis to regulate the sperm function by exosomes.
Harleen Kaur, Alison S Care, Rebecca L Wilson, Sandra G Piltz, Paul Q Thomas, Beverly S Muhlhausler, Claire T Roberts, and Kathryn L Gatford
Animal models are needed to develop interventions to prevent or treat intrauterine growth restriction (IUGR). Foetal growth rates and effects of in utero exposures differ between sexes, but little is known about sex-specific effects of increasing litter size. We established a murine IUGR model using pregnancies generated by multiple embryo transfers, and evaluated sex-specific responses to increasing litter size. CBAF1 embryos were collected at gestation day 0.5 (GD0.5) and 6, 8, 10 or 12 embryos were transferred into each uterine horn of pseudopregnant female CD1 mice (n = 32). Foetal and placental outcomes were measured at GD18.5. In the main experiment, foetuses were genotyped (Sry) for analysis of sex-specific outcomes. The number of implantation sites (P = 0.033) and litter size (number of foetuses, P = 0.008) correlated positively with the number of embryos transferred, while placental weight correlated negatively with litter size (both P < 0.01). The relationship between viable litter size and foetal weight differed between sexes (interaction P = 0.002), such that foetal weights of males (P = 0.002), but not females (P = 0.233), correlated negatively with litter size. Placental weight decreased with increasing litter size (P < 0.001) and was lower in females than males (P = 0.020). Our results suggest that male foetuses grow as fast as permitted by nutrient supply, whereas the female maintains placental reserve capacity. This strategy reflecting sex-specific gene expression is likely to place the male foetus at greater risk of death in the event of a ‘second hit’.