Study on the mechanism of glucocorticoid receptor mitochondrial translocation and glucocorticoid-induced apoptosis in macrophages.

OBJECTIVE: Our research aimed to investigate the therapeutic effects of Tubastatin-A, a glucocorticoid receptor (GR) mitochondrial translocation inhibitor, and mitoquinone (MitoQ), an antioxidant, on attenuating dexamethasone (DEX)-induced macrophage apoptosis. METHODS: We treated RAW264.7 macrophages with different combinations of DEX and either Tubastatin-A or MitoQ. Parameters such as mitochondrial GR translocation, mitochondrial reactive oxygen species levels, mitochondrial membrane potential, mitochondrial permeability transition pore opening, cytochrome C efflux to the cytosol, and apoptosis were subsequently evaluated in the different treatment groups via qRT-PCR, western blotting, and immunofluorescence assays. RESULTS: DEX intervention increased the translocation of GRs into the mitochondria, while reducing the expression of the mitochondrial gene MT-CO1 and the activity of mitochondrial respiratory chain complex IV in macrophages. In addition, DEX administration increased mtROS levels, mitochondrial permeability transition pore opening, and mitochondrial cytochrome C release in macrophages, which promoted their apoptosis. We found that Tubastatin-A inhibited mitochondrial GR translocation and reversed the DEX-induced increase in GR levels within the mitochondria. Furthermore, Tubastatin-A mitigated various mitochondrial changes induced by DEX, including reducing the efflux of mitochondrial cytochrome C and inhibiting macrophage apoptosis. Similarly, MitoQ exerted its effects on macrophage apoptosis by reducing mtROS levels through the mitochondrial pathway. CONCLUSIONS: The DEX-mediated translocation of GR into mitochondria disrupts the mitochondrial function of macrophages, which induces their apoptosis. By inhibiting mitochondrial translocation of GR and reducing mtROS levels, Tubastatin-A and MitoQ can effectively attenuate macrophage apoptosis, which has clinical implications for reducing the notable side effects associated with glucocorticoid use.

Impact of telomere length and mitochondrial DNA copy number variants on survival of newborn cloned calves.

An established technology to create cloned animals is through the use of somatic cell nuclear transfer (SCNT), in which reprogramming the somatic cell nucleus to a totipotent state by enucleated oocyte cytoplasm is a necessary process, including telomere length reprogramming. The limitation of this technology; however, is that the live birth rate of offspring produced through SCNT is significantly lower than that of IVF. Whether and how telomere length play a role in the development of cloned animals is not well understood. Only a few studies have evaluated this association in cloned mice, and fewer still in cloned cows. In this study, we investigated the difference in telomere length as well as the abundance of some selected molecules between newborn deceased cloned calves and normal cows of different ages either produced by SCNT or via natural conception, in order to evaluate the association between telomere length and abnormal development of cloned cows. The absolute telomere length and relative mitochondrial DNA (mtDNA) copy number were determined by real-time quantitative PCR (qPCR), telomere related gene abundance by reverse-transcription quantitative PCR (RT-qPCR), and senescence-associated ß-galactosidase (SA-ß-gal) expression by SA-ß-gal staining. The results demonstrate that the newborn deceased SCNT calves had significantly shortened telomere lengths compared to newborn naturally conceived calves and newborn normal SCNT calves. Significantly lower mtDNA copy number, and significantly lower relative abundance of LMNB1 and TERT, higher relative abundance of CDKN1A, and aberrant SA-ß-gal expression were observed in the newborn deceased SCNT calves, consistent with the change in telomere length. These results demonstrate that abnormal telomere shortening, lower mtDNA copy number and abnormal abundance of related genes were specific to newborn deceased SCNT calves, suggesting that abnormally short telomere length may be associated with abnormal development in the cloned calves.

GPR160 regulates the self-renewal and pluripotency of mouse embryonic stem cells via JAK1/STAT3 signal pathway.

G protein-coupled receptors (GPCRs) are the largest family of transmembrane receptors and regulate various physiological and pathological processes. Despite extensive studies, the roles of GPCRs in mouse embryonic stem cells (mESCs) represent a significant data gap. Here, we show that GPR160, a class A member of GPCRs, is dramatically downregulated concurrent with mESC differentiation into embryoid bodies in vitro. Knockdown of GPR160 leads to downregulation of the expression of pluripotency-associated transcription factors and upregulation of the expression of lineage markers, accompanying with the arrest of the mESC cell cycle in the G0/G1 phase. RNA-seq analysis shows that GPR160 participates in the JAK/STAT signaling pathway crucial for maintaining ESC stemness, and the knockdown of GPR160 results in the downregulation of STAT3 phosphorylation level, which in turn is partially rescued by colivelin, a STAT3 activator. Constant with these observations, GPR160 physically interacts with JAK1, and cooperates with leukemia inhibitory factor receptor (LIFR) and gp130 to activate the STAT3 pathway. In summary, our results suggest that GPR160 regulates mESC self-renewal and pluripotency by interacting with the JAK1-LIFR-gp130 complex to mediate the JAK1/STAT3 signaling pathway.

Reporting and data-sharing level of acupuncture randomised controlled trials: a cross-sectional study protocol.

INTRODUCTION: Randomised controlled trials (RCTs) play an important role in evidence-based medicine. However, an article with low reporting quality may mislead both experts and the general public into an erroneous decision. Data sharing can contribute to the truthfulness and transparency of trials. Acupuncture RCTs have been increasing rapidly these years, but the reporting quality and data-sharing level of acupuncture RCTs are not clear. Thus, this study will provide the current status of the reporting quality and data-sharing level of acupuncture RCTs. METHODS AND ANALYSIS: A cross-sectional study will be conducted. The seven databases including MEDLINE, EMBASE, CENTRAL, CBM, CNKI, Wanfang Database and VIP will be searched between 1 January 2012 and 15 October 2022 to identify acupuncture RCTs. The basic characteristics of included trials will be summarised. The reporting quality for included RCTs will be assessed by the Consolidated Standards for Reporting Trials 2010 statement and the Standards for Reporting Interventions in Controlled Trials of Acupuncture. The data-sharing level will be assessed by open science practices. ETHICS AND DISSEMINATION: Ethical approval is not required for this study. This protocol has been registered in Open Science Framework Registries. The findings of this study will be submitted to a peer-reviewed academic journal.

Maternal Prkce expression in mature oocytes is critical for the first cleavage facilitating maternal-to-zygotic transition in mouse early embryos.

OBJECTIVES: Early embryo development is dependent on the regulation of maternal messages stored in the oocytes during the maternal-to-zygote transition. Previous studies reported variability of oocyte competence among different inbred mouse strains. The present study aimed to identify the maternal transcripts responsible for early embryonic development by comparing transcriptomes from oocytes of high- or low- competence mouse strains. MATERIALS AND METHODS: In vitro fertilization embryos from oocytes of different mouse strains were subject to analysis using microarrays, RNA sequencing, real-time quantitative PCR (RT-qPCR) analysis, Western blotting, and immunofluorescence. One candidate gene, Prkce, was analysed using Prkce knockout mice, followed by a cRNA rescue experiment. RESULTS: The fertilization and 2-cell rate were significantly higher for FVB/NJ (85.1% and 82.0%) and DBA/2J (79.6% and 76.7%) inbred mouse strains than those for the MRL/lpr (39.9% and 35.8%) and 129S3 (35.9% and 36.6%) strains. Thirty-nine differentially expressed genes (DEGs) were noted, of which nine were further verified by RT-qPCR. Prkce knockout mice showed a reduced 2-cell rate (Prkce+/+ 80.1% vs. Prkce-/- 32.4%) that could be rescued by Prkce cRNA injection (2-cell rate reached 76.7%). Global transcriptional analysis revealed 143 DEGs in the knockout mice, which were largely composed of genes functioning in cell cycle regulation. CONCLUSIONS: The transcription level of maternal messages such as Prkce in mature oocytes is associated with different 2-cell rates in select inbred mouse strains. Prkce transcript levels could serve as a potential biomarker to characterize high-quality mature oocytes.

Integration-free methods for generating induced pluripotent stem cells.

Induced pluripotent stem (iPS) cells can be generated from mouse or human fibroblasts by exogenous expression of four factors, Oct4, Sox2, Klf4 and c-Myc, and hold great potential for transplantation therapies and regenerative medicine. However, use of retroviral vectors during iPS cell generation has limited the technique's clinical application due to the potential risks resulting from genome integration of transgenes, including insertional mutations and altered differentiation potentials of the target cells, which may lead to pathologies such as tumorigenesis. Here we review recent progress in generating safer transgene-free or integration-free iPS cells, including the use of non-integrating vectors, excision of vectors after integration, DNA-free delivery of factors and chemical induction of pluripotency.

Donor-host mitochondrial compatibility improves efficiency of bovine somatic cell nuclear transfer.

BACKGROUND: The interaction between the karyoplast and cytoplast plays an important role in the efficiency of somatic cell nuclear transfer (SCNT), but the underlying mechanism remains unclear. It is generally accepted that in nuclear transfer embryos, the reprogramming of gene expression is induced by epigenetic mechanisms and does not involve modifications of DNA sequences. In cattle, oocytes with various mitochondrial DNA (mtDNA) haplotypes usually have different ATP content and can further affect the efficiency of in vitro production of embryos. As mtDNA comes from the recipient oocyte during SCNT and is regulated by genes in the donor nucleus, it is a perfect model to investigate the interaction between donor nuclei and host oocytes in SCNT. RESULTS: We investigated whether the in vitro development of reconstructed bovine embryos produced by SCNT would be influenced by mtDNA haplotype compatibility between the oocytes and donor cells. Embryos from homotype A-A or B-B showed significantly higher developmental ability at blastocyst stages than the heterotype A-B or B-A combinations. Post-implantation development ability, pregnancy rate up to day 90 of gestation, as well as percent of term births were higher in the homotype SCNT groups than in the heterotype groups. In addition, homotype and heterotype SCNT embryos showed different methylation patterns of histone 3-lysine 9 (H3K9) genome-wide and at pluripotency-related genes (Oct-4, Sox-2, Nanog). CONCLUSION: Both histone and DNA methylation show that homotype SCNT blastocysts have a more successful epigenetic asymmetry pattern than heterotype SCNT blastocysts, which indicates more complete nuclear reprogramming. This may result from variability in their epigenetic patterns and responses to nuclear reprogramming. This suggests that the compatibility of mtDNA haplotypes between donor cells and host oocytes can significantly affect the developmental competence of reconstructed embryos in SCNT, and may include an epigenetic mechanism.

Improved efficiency of bovine somatic cell nuclear transfer by optimizing operational procedures.

To improve bovine somatic cell nuclear transfer (SCNT) efficiency, we studied various aspects to optimize the experimental procedures. Firstly, donor cells were treated with pronase, which resulted in a higher fusion rate than that of cells without the pronase treatment (78.3 vs. 53.9%). Secondly, when fused embryos were activated either by chemical (ionomycin + cyclohemixide (CHX)) or electrical + CHX stimulation, the cleavage and blastocyst formation rates were comparable amongst these treatment groups (P>0.05); however, mortality following electrical + CHX activation was significantly higher than that observed with the chemical activation, regardless of the pronase treatment (P<0.05). Finally, we compared the culture conditions of the reconstructed embryos using ACM medium plus mouse embryonic fibroblasts (MEF) vs. B2 medium plus granulose cells (GC), and the results clearly demonstrated that the former culture conditions led to a higher blastocyst rate, 90-day pregnancy rate, and newborn rate, than that observed for culture in B2 medium plus GC (46.7 vs. 34.7%, 36.1 vs. 9.6% and 25.9 vs. 5.8% for the blastocyst, pregnancy and newborn rates, respectively). In summary, the efficiency of bovine SCNT can be greatly improved using optimized operational procedures, including treating the donor cells with pronase, activation of fused embryos by ionomycin + CHX and the culture of the reconstructed embryos in ACM + MEF media.

[Two vital transcriptional factors Oct-4 and Nanog to keep the pluripotency and self-renewal of stem cells and related regulation network].

Oct-4 and Nanog are two critical transcriptional factors to keep pluripotency and self-renewal of stem cells in vivo and in vitro, and they usually express only in pluripotent cells and not in differentiated cells. They bind to the regulatory regions of targeted gene and often interact with other transcriptional factors and extracellular signal path components, such as Sox-2, FoxD3, LIF and BMP in specific tissues or developmental stages. So that all of these constitute a transcriptional crosstalk, and finally determine the cells destiny: keeping pluripotency or turning to differentiation.