Cadmium induces ovarian granulosa cell damage by activating PERK-eIF2α-ATF4 through endoplasmic reticulum stress.

This study aimed to investigate whether cadmium induces ovarian granulosa cell damage by activating protein kinase R-like endoplasmic reticulum kinase (PERK)-eIF2α-ATF4 through endoplasmic reticulum (ER) stress and to elucidate the underlying regulation mechanism. Two models of cadmium exposure were established. In one model, ovarian granulosa cells isolated from 21-day-old female Sprague Dawley rats were cultured in vitro for 36 h and exposed to CdCl2 (0, 5, 10, and 20 µM), and in another model, a human ovarian granulosa tumor cell line (COV434) was used to construct the binding immunoglobulin protein (BIP)-knockdown cell line sh-BIP and exposed to 0 and 20 µM CdCl2. After exposure to cadmium for 12 h, the expression mRNA and protein levels of BIP, p-PERK, and p-eIF2α were determined in the two models. miRNAs related to BIP were also detected in granulosa cells after cadmium exposure. We found that mRNA and protein levels of all factors were upregulated in each cadmium-dose group, except for BIP mRNA expression in the 5 µM Cd group. The BIP gene was knocked down in COV434 cells before exposure to cadmium. All factors were upregulated in COV434 cells exposed to Cd, and the expression of the p-eIF2α protein was downregulated in sh-BIP cells exposed to Cd. In addition, no differences in BIP-related miRNAs were detected in cadmium-exposed rat ovarian granulosa cells versus the control group. Cadmium induces ovarian granulosa cell damage by inducing ER stress.

Small non-coding RNAs and their associated proteins in spermatogenesis.

The importance of the gene regulation roles of small non-coding RNAs and their protein partners is of increasing focus. In this paper, we reviewed three main small RNA species which appear to affect spermatogenesis. MicroRNAs (miRNAs) are single stand RNAs derived from transcripts containing stem-loops and hairpins which target corresponding mRNAs and affect their stability or translation. Many miRNA species have been found to be related to normal male germ cell development. The biogenesis of piRNAs is still largely unknown but several models have been proposed. Some piRNAs and PIWIs target transposable elements and it is these that may be active in regulating translation or stem cell maintenance. endo-siRNAs may also participate in sperm development. Some possible interactions between different kinds of small RNAs have even been suggested. We also show that male germ granules are seen to have a close relationship with a considerable number of mRNAs and small RNAs. Those special structures may also participate in sperm development.

Endometrial stromal cells and decidualized stromal cells: origins, transformation and functions.

Decidualization of endometrium, which is characterized by endometrial stromal cell (ESC) decidualization, vascular reconstruction, immune cell recruitment, and plentiful molecule production, is a crucial step for uterus to become receptive for embryo. When implantation takes place, ESCs surround and directly interact with embryo. Decidualized stromal cells (DSCs) are of great importance in endometrial decidualization, having a broad function in regulating immune activity and vascular remodeling of uterus. DSCs are shown to have a higher metabolic level and looser cytoskeleton than ESCs. What's the origin of ESCs and how ESCs successfully transform into DSCs had puzzled scientists in the last decades. Breakthrough had been achieved recently, and many studies had elucidated some of the characters and functions of DSCs. However, several questions still remain unclear. This paper reviews current understanding of where ESCs come from and how ESCs differentiate into DSCs, summarizes some characters and functions of DSCs, analyzes current studies and their limitations and points out research areas that need further investigation.

[Effects of bisphenol A on OCT4 and SOX2 genes expression in mouse embryonic stem cells].

OBJECTIVE: To explore the effects of bisphenol A (BPA) exposure on toxicity characteristic and OCT4 and SOX2 gene expression of mouse embryonic stem cells (mESC). METHODS: mESC were cultured, and treated with the doses of 10(-8), 10(-7), 10(-6), 10(-5), 10(-4) mol/L respectively of BPA and DMSO (the solvent control group)for 24 hours, and three groups of cells were treated with the same method. The morphological changes of mESC in the control and exposure groups were observed through an inverted microscope. Cell counting kit 8 (CCK8) was used to detect the effects of BPA on proliferation of mESC, and based on the results, the half inhibitory concentration (IC50) was calculated. Real-time fluorescent quantitative polymerase chain reaction (RT-QPCR) and western blotting were used to detect the expression of OCT4 and SOX2. RESULTS: BPA had certain toxicity on mESC, the treatment of BPA significantly increased cell toxicity in a concentration-dependent manner, and the IC50 was 4.3×10(-4) mol/L, combined with the BPA exposure concentration of the environment and the related literature, eventually taking the five concentrations of 10(-8), 10(-7), 10(-6), 10(-5), 10(-4) mol/L as the experimental groups. The mESC morphology were effected after the treatment of BPA for 24 h, compared with the control group, the number of cells decreased, appearing some floating cells, and the cell cloning became irregular and differentiation in the higher concentration groups. The OCT4 mRNA expression level in the 10(-7) mol/L (1.146 ± 0.087), 10(-6) mol/L (1.156 ± 0.030), 10(-5) mol/L (1.158 ± 0.103) and the 10(-4) mol/L (1.374 ± 0.053) dose group were all significantly higher than the control group (1.000 ± 0.000) (t values were -2.384, -2.953, -3.203, -4.021 respectively, P value all < 0.05). Meanwhile, the SOX2 mRNA expression level in the 10(-4) mol/L (1.113 ± 0.052) were higher than the control group (1.000 ± 0.000) (t value was -2.765, P value < 0.05). Moreover, the OCT4 protein expression level in the 10(-5) mol/L (1.360 ± 0.168) and 10(-4) mol/L (1.602 ± 0.151) were all significantly higher than the control group (1.000 ± 0.000) (t values were -3.538, -4.002 respectively, P value all < 0.05), while no obvious change of the SOX2 protein expression level was detected in all treated groups. CONCLUSION: BPA in a certain dose range could upregulate the expression of OCT4 gene in mouse embryonic stem cells while had no significant effect on the expression of SOX2 gene.

Nuclear factors: roles related to mitochondrial deafness.

Hearing loss (HL) is a common disorder with mitochondrial dysfunction as one of the major causes leading to deafness. Mitochondrial dysfunction may be caused by either mutations in nuclear genes leading to defective nuclear-encoded proteins or mutations in mitochondrial genes leading to defective mitochondrial-encoded products. The specific nuclear genes involved in HL can be classified into two categories depending on whether mitochondrial gene mutations co-exist (modifier genes) or not (deafness-causing genes). TFB1M, MTO1, GTPBP3, and TRMU are modifier genes. A mutation in any of these modifier genes may lead to a deafness phenotype when accompanied by the mitochondrial gene mutation. OPA1, TIMM8A, SMAC/DIABLO, MPV17, PDSS1, BCS1L, SUCLA2, C10ORF2, COX10, PLOG1and RRM2B are deafness-causing genes. A mutation in any of these deafness-causing genes will directly induce variable phenotypic HL.