Previous studies have shown that primordial germ cell‐like cells (PGCLCs) can be obtained from human, porcine and mouse skin‐derived stem cells (SDSCs). In this paper, we found retinoic acid (RA), the active derivative of vitamin A, accelerated the growth of porcine primordial germ cells (pPGCs) and porcine PGCLCs (pPGCLCs) which were derived from porcine SDSCs (pSDSCs). Moreover, flow cytometry results revealed that the proliferation promoting effect of RA was attenuated by U0126, a specific inhibitor of extracellular signal‐regulated kinase (ERK). Western blot analysis showed the protein level of ERK, phosphorylated ERK, cyclin D1 (CCND1), and cyclin‐dependent kinase 2 (CDK2) increased after stimulation with RA, and this effect could also be abolished by U0126. Our data revealed that ablation of ERK expression by U0126 should significantly decrease proliferation of pPGCLCS. This reduction was because CCND1 and CDK2 proteins level decrease and subsequently the pPGCLCs were arrested in the G0/G1 phase. In addition, we also confirmed RA indeed promoted the proliferation of pPGCs isolated from porcine fetal genital ridges in vitro. Furthermore, our data indicated that DNA methylation pattern were changed in pPGCLCs and this pattern were more similar to pPGCs.

This study, using an in vitro ovary culture model, investigates the mechanisms through which di(2‐ethylhexyl)phthalate (DEHP) impairs germ cell cyst breakdown and primordial follicle assembly. The results indicate the latter effects exerted by 10 or 100 µmol/L DEHP in cultured newborn ovaries were associated with increased levels of reactive oxygen species (ROS) and apoptosis. Based on a transcriptome analysis, we found the expression of the oxidative stress–related gene Xdh (xanthine dehydrogenase) was significantly upregulated in DEHP‐cultured ovaries. Two treatments, namely Xdh RNAi or the addition of melatonin to the ovary culture, inhibited the increase in Xdh expression and ROS levels caused by DEHP and, at the same time, reduced apoptosis and the impairment of primordial follicle assembly in the treated ovaries. Together, the results identify Xdh gene as one of the major targets of DEHP in newborn ovaries and that the consequent increased level of ROS is possibly responsible for the increment of apoptosis and primordial follicle assembly impairment. At the same time, they highlight that melatonin alleviates the effects of DEHP as with other endocrine‐disrupting compounds on the ovary.

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Background The transdifferentiation of skin‐derived stem cells (SDSCs) into primordial germ cell‐like cells (PGCLCs) is one of the major breakthroughs in the field of stem cells research in recent years. This technology provides a new theoretical basis for the treatment of human infertility. However, the transdifferentiation efficiency of SDSCs to PGCLCs is very low, and scientists are still exploring ways to improve this efficiency or promote the proliferation of PGCLCs. This study aims to investigate the molecular mechanism of luteinising hormone (LH) to enhance porcine PGCLCs (pPGCLCs) proliferation. Results In this study, we dissected the proliferation regulatory network of pPGCLCs by whole transcriptome sequencing, and the results showed that the pituitary‐secreted reproductive hormone LH significantly promoted the proliferation of pPGCLCs. We combined whole transcriptome sequencing and related validation experiments to explore the mechanism of LH on the proliferation of pPGCLCs, and found that LH could affect the expression of Hippo signalling pathway‐related mRNAs, miRNAs and lncRNAs in pPGCLCs. Conclusions For the first time, we found that LH promotes pPGCLCs proliferation through the competing endogenous RNA (ceRNA) regulatory networks and Hippo signalling pathway. This finding may help to elucidate the molecular mechanism by which LH promotes pPGCLCs proliferation.

BackgroundSkin-derived stem cells (SDSCs) are a class of adult stem cells (ASCs) that have the ability to self-renew and differentiate. The regulation mechanisms involved in the differentiation of ASCs is a hot topic.Porcine models have close similarities to humans and porcine SDSCs (pSDSCs) offer an ideal in vitro model to investigate human ASCs. To date, studies concerning the role of yes-associated protein (YAP) in ASCs are limited, and the mechanism of its in uence on self-renewal and differentiation of ASCs remain unclear. In this paper, we explore the link between the transcriptional regulator YAP and the fate of pSDSCs. ResultsWe found that YAP promotes the pluripotent state of pSDSCs by maintaining the high expression of the pluripotency genes Sox2, Oct4. The overexpression of YAP prevented the differentiation of pSDSCs and the depletion of YAP by small interfering RNA (siRNAs) suppressed the self-renewal of pSDSCs. In addition, we found that YAP regulates the fate of pSDSCs through a mechanism related to the Wnt/βcatenin signaling pathway. When an activator of the Wnt/β-catenin signaling pathway, CHIR99021, was added to pSDSCs overexpressing YAP the ability of pSDSCs to differentiate was partially restored.Conversely, when XAV939 an inhibitor of Wnt/β-catenin signaling pathway, was added to YAP knockdown pSDSCs a higher self-renewal ability resulted. Conclusionsour results suggested that, YAP and the Wnt/β-catenin signaling pathway interact to regulate the fate of pSDSCs.