Oocytes could rearrange immunoglobulin production to survive over adverse environmental stimuli.

Immunoglobulins are key humoral immune molecules produced and secreted by B lymphocytes at various stages of differentiation. No research has reported whether immunoglobulins are present in the non-proliferative female germ cells-oocytes-and whether they are functionally important for oocyte quality, self-protection, and survival. Herein, we found that IgG was present in the oocytes of immunodeficient mice; the IgG-VDJ regions were highly variable between different oocytes, and H3K27Ac bound and regulated the IgG promoter region. Next, IgG mRNA and protein levels increased in response to LPS, and this increment was mediated by CR2 on the oocyte membrane. Finally, we revealed three aspects of the functional relevance of oocyte IgG: first, oocytes could upregulate IgG to counteract the increased ROS level induced by CSF1; second, oocytes could upregulate IgG in response to injected virus ssRNA to maintain mitochondrial integrity; third, upon bacterial infection, oocytes could secrete IgG, subsequently encompassing the bacteria, thus increasing survival compared to somatic cells. This study reveals for the first time that the female germ cells, oocytes, can independently adjust intrinsic IgG production to survive in adverse environments.

Gm364 coordinates MIB2/DLL3/Notch2 to regulate female fertility through AKT activation.

Many integral membrane proteins might act as indispensable coordinators in specific functional microdomains to maintain the normal operation of known receptors, such as Notch. Gm364 is a multi-pass transmembrane protein that has been screened as a potential female fertility factor. However, there have been no reports to date about its function in female fertility. Here, we found that global knockout of Gm364 decreased the numbers of primordial follicles and growing follicles, impaired oocyte quality as indicated by increased ROS and γ-H2AX, decreased mitochondrial membrane potential, decreased oocyte maturation, and increased aneuploidy. Mechanistically, Gm364 directly binds and anchors MIB2, a ubiquitin ligase, on the membrane. Subsequently, membrane MIB2 ubiquitinates and activates DLL3. Next, the activated DLL3 binds and activates Notch2, which is subsequently cleaved within the cytoplasm to produce NICD2, the intracellular active domain of Notch2. Finally, NICD2 can directly activate AKT within the cytoplasm to regulate oocyte meiosis and quality.

ATP5O Hypo-crotonylation Caused by HDAC2 Hyper-Phosphorylation Is a Primary Detrimental Factor for Downregulated Phospholipid Metabolism under Chronic Stress.

Objective. Chronic stress (CS)-induced abnormal metabolism and other subsequent aspects of abnormality are threatening human health. Little is known regarding whether and how protein post-translational-modifications (PTMs) correlate with abnormal metabolism under CS. The aim of this study was to address this issue and also identify novel key protein PTM. Methods. First, we screened which pan-PTM had significant change between control and CS female mice and whether clinical CS females had similar pan-PTM change. Second, we performed quantitative PTM-omics and metabolomics to verify the correlation between abnormal protein PTMs and atypical metabolism. Third, we performed quantitative phospho-omics to identify the key PTM-regulating enzyme and investigate the interaction between PTM protein and PTM-regulating enzyme. Fourth, we attempted to rectify the abnormal metabolism by correcting the activity of the PTM-regulating enzyme. Finally, we examined whether the selected key protein was also correlated with stress scores and atypical metabolism in clinical women. Results. We initially found that multiple tissues of CS female mice have downregulated pan-crotonylation, and verified that the plasma of clinical CS females also had downregulated pan-crotonylation. Then we determined that ATP5O-K51 crotonylation decreased the most and also caused gross ATP5O decrement, whereas the plasma of CS mice had downregulated phospholipids. Next, downregulating ATP5O crotonylation partially recapitulated the downregulated phospholipid metabolism in CS mice. Next, we verified that HDAC2-S424 phosphorylation determined its decrotonylation activity on ATP5O-K51. Furthermore, correcting HDAC2 hyper-phosphorylation recovered the gross ATP5O level and partially rescued the downregulated phospholipid metabolism in CS mice. Finally, the ATP5O level was also significantly lower and correlated with high stress scores and downregulated phospholipid metabolism in clinical female plasma. Conclusion. This study discovered a novel PTM mechanism involving two distinct types of PTM in CS and provided a novel reference for the clinical precautions and treatments of CS.

Rat BAT xenotransplantation recovers the fertility and metabolic health of PCOS mice.

Polycystic ovarian syndrome (PCOS) is a major severe ovary disorder affecting 5-10% of reproductive women around the world. PCOS can be considered a metabolic disease because it is often accompanied by obesity and diabetes. Brown adipose tissue (BAT) contains abundant mitochondria and adipokines and has been proven to be effective for treating various metabolic diseases. Recently, allotransplanted BAT successfully recovered the ovarian function of PCOS rat. However, BAT allotransplantation could not be applied to human PCOS; the most potent BAT is from infants, so voluntary donors are almost inaccessible. We recently reported that single BAT xenotransplantation significantly prolonged the fertility of aging mice and did not cause obvious immunorejection. However, PCOS individuals have distinct physiologies from aging mice; thus, it remains essential to study whether xenotransplanted rat BAT can be used for treating PCOS mice. In this study, rat-to-mouse BAT xenotransplantation, fortunately, did not cause severe rejection reaction, and significantly recovered ovarian functions, indicated by the recovery of fertility, oocyte quality, and the levels of multiple essential genes and kinases. Besides, the blood biochemical index, glucose resistance, and insulin resistance were improved. Moreover, transcriptome analysis showed that the recovered PCOS F0 mother following BAT xenotransplantation could also benefit the F1 generation. Finally, BAT xenotransplantation corrected characteristic gene expression abnormalities found in the ovaries of human PCOS patients. These findings suggest that BAT xenotransplantation could be a novel therapeutic strategy for treating PCOS patients.

Single xenotransplant of rat brown adipose tissue prolonged the ovarian lifespan of aging mice by improving follicle survival.

Prolonging the ovarian lifespan is attractive and challenging. An optimal clinical strategy must be safe, long-acting, simple, and economical. Allotransplantation of brown adipose tissue (BAT), which is most abundant and robust in infants, has been utilized to treat various mouse models of human disease. Could we use BAT to prolong the ovarian lifespan of aging mice? Could we try BAT xenotransplantation to alleviate the clinical need for allogeneic BAT due to the lack of voluntary infant donors? In the current study, we found that a single rat-to-mouse (RTM) BAT xenotransplantation did not cause systemic immune rejection but did significantly increase the fertility of mice and was effective for more than 5 months (equivalent to 10 years in humans). Next, we did a series of analysis including follicle counting; AMH level; estrous cycle; mTOR activity; GDF9, BMP15, LHR, Sirt1, and Cyp19a level; ROS and annexin V level; IL6 and adiponectin level; biochemical blood indices; body temperature; transcriptome; and DNA methylation studies. From these, we proposed that rat BAT xenotransplantation rescued multiple indices indicative of follicle and oocyte quality; rat BAT also improved the metabolism and general health of the aging mice; and transcriptional and epigenetic (DNA methylation) improvement in F0 mice could benefit F1 mice; and multiple KEGG pathways and GO classified biological processes the differentially expressed genes (DEGs) or differentially methylated regions (DMRs) involved were identical between F0 and F1. This study could be a helpful reference for clinical BAT xenotransplantation from close human relatives to the woman.

The ubiquitin ligase KBTBD8 regulates PKM1 levels via Erk1/2 and Aurora A to ensure oocyte quality.

Tight control of energy metabolism is essential for normal cell function and organism survival. PKM (pyruvate kinase, muscle) isoforms 1 and 2 originate from alternative splicing of PKM pre-mRNA. They are key enzymes in oxidative phosphorylation and aerobic glycolysis, respectively, and are essential for ATP generation. The PKM1:PKM2 expression ratio changes with development and differentiation, and may also vary under metabolic stress and other conditions. Until now, there have been no reports about the function and regulation of PKM isozymes in oocytes. Here, we demonstrate that PKM1 or PKM2 depletion significantly disrupts ATP levels and mitochondrial integrity, and exacerbates free-radical generation and apoptosis in mouse oocytes. We also show that KBTBD8, a female fertility factor in the KBTBD ubiquitin ligase family, selectively regulates PKM1 levels through a signaling cascade that includes Erk1/2 and Aurora A kinases as intermediates. Finally, using RNA sequencing and protein network analysis, we identify several regulatory proteins that may be govern generation of mature PKM1 mRNA. These results suggest KBTBD8 affects PKM1 levels in oocytes via a KBTBD8→Erk1/2→Aurora A axis, and may also affect other essential processes involved in maintaining oocyte quality.

Placenta-specific 1 regulates oocyte meiosis and fertilization through furin.

Placenta-specific 1 (Plac1) has been found to be essential for placentation, and abnormal Plac1 expression and distribution is highly correlated with preeclampsia and implantation failure; however, its function in mammalian oocytes has not been elucidated. Here, we report that Plac1 was more prominent in mouse oocytes and enriched at the membrane region throughout meiosis. On the one hand, Plac1 knockdown severely disrupted microvillus organization; however, on the other hand, Plac1 significantly decreased oocyte maturation and increased aneuploidy, consequently disrupting normal fertilization. On the basis of immunoprecipitate matrix-assisted laser desorption/ionization, we established a working model, then verified and suggested that, at the germinal vesicle stage, Plac1 enriches the membrane to activate furin, and active furin subsequently activates IGF-1 receptor to maintain regular microvillus organization. Upon meiosis onset, active furin/IGF-1 receptor relocates into the cytoplasm to activate (phosphorylate) Akt to promote meiosis. In summary, our finding suggests that Plac1, a protein that is crucial for placentation, is also essential for oocyte meiosis and fertilization.-Shi, L.-Y., Ma, Y., Zhu, G.-Y., Liu, J.-W., Zhou, C.-X., Chen, L.-J., Wang, Y., Li, R.-C., Yang, Z.-X., Zhang, D. Placenta-specific 1 regulates oocyte meiosis and fertilization through furin.

[Clinical value of cast post-core porcelain fused to metal crown in restorating residual root and crown of molars].

OBJECTIVE: To investigate the effect of cast post-core porcelain fused to metal crown on the restoration of residual root and crown of molars. METHODS: One hundred and sixty-four residual roots and crowns of molars were treated with root canal therapy and restored by cast core porcelain fused to metal crown. The restoration effect was assessed at the 3rd, 6th, 12th and 24th month. RESULTS: The strength of dental prosthesis retention, marginal fitness, and strength of crowns were satisfactory. The effective rate reached 95.12% during the 2 year follow-up. CONCLUSION: The cast post-core porcelain fused to metal crown is a better method in treating the residual root and crown of molars.

[Detection of telomerase activity in salivary tumor and its significance].

OBJECTIVE: To investigate telomerase activity in human salivary cancer and corresponding adjacent tissues and to explore the possibility of telomerase as a tumor marker and its clinical significance. METHODS: Twenty-eight salivary cancers, 28 adjacent peritumoral tissues, 10 mixed tumors, 6 adenolymphomas, and 5 normal salivary tissues were examined for telomerase activity by the silver-staining TRAP assay based on PCR. RESULTS: Twenty-five of the 28 salivary cancers and 2 of the 28 adjacent peritumoral tissue specimens were positive for telomerase activity with a positive rate of 89.3% and 6.3%, respectively. Telomerase activity was negative in the 10 mixed tumors, 6 adenolymphomas, and 5 normal salivary tissues. There was no correlation between the clinical stage of salivary cancer and its expression of telomerase activity (P > 0.05). CONCLUSION: Positive telomerase activity occurs in the majority of salivary cancers examined. It can be used as a tumor marker in the diagnosis of salivary cancer. Detection of telomerase activity in the adjacent peritumoral tissues can be used as a monitoring marker after treatment.