LARS2 Regulates Apoptosis via ROS-Mediated Mitochondrial Dysfunction and Endoplasmic Reticulum Stress in Ovarian Granulosa Cells

Stem cell-based therapeutic potential in female ovarian aging and infertility

Premature ovarian insufficiency (POI) is defined as onset of menopause characterized by amenorrhea, hypergonadotropism, and hypoestrogenism, before the age of 40 years. The POI is increasing, which seriously affects the quality of patients' life. Due to its diversity of pathogenic factors, complex pathogenesis and limited treatment methods, the search for finding effective treatment of POI has become a hotspot. Stem cells are characterized by the ability of self-renewal and differentiation and play an important role in the regeneration of injured tissues, which is therapy is expected to be used in the treatment of POI. The aim of this review is to summarize the pathogenic mechanisms and the research progress of POI treatment with stem cells from different sources.

hUMSCs restore ovarian function in POI mice by regulating GSK3β-mediated mitochondrial dynamic imbalances in theca cells

Premature ovarian insufficiency (POI), a major cause of female infertility, is defined as follicular atresia and a rapid loss of germ cells in women of reproductive age due to ovarian failure. Recently, findings from several studies have indicated that human umbilical cord mesenchymal stem cells (hUMSCs) can alleviate ovarian dysfunction resulting from POI. However, the mechanisms underlying this effect require further clarification. In this study, a mouse model of POI was established as achieved with an intraperitoneal injection of cyclophosphamide (CTX) into female C57BL/6J mice in vivo. These POI mice received a 1-week intervention of hUMACs. In addition, an in vitro POI model was also included. The cultured supernatants of hUMSCs and glycogen synthase kinase 3 beta (GSK3β) inhibitor (SB216763) were used to treat theca cells (TCs) exposed to CTX. Hematoxylin and Eosin (H&E) staining and Enzyme-linked immunosorbent assay (ELISA) were used to assess ovarian structure and morphology, as well as endocrine function in these POI mice. Based on results from the ELISA and JC-1 labeling, CTX exerted significant detrimental effects on testosterone levels and the mitochondrial membrane potential in TCs. Subsequently, Western Blot, Immunofluorescence staining (IF), and Quantitative real-time polymerase chain reaction (qRT-PCR) were used to evaluate various indicators of testosterone synthesis function and mitochondrial dynamics in ovaries and TCs of POI mice. In vivo, dysfunctions in ovarian structure and function in the POI mouse model were effectively restored following hUMSCs treatment, and abnormalities in hormone synthesis were significantly reduced. Furthermore, when the stem cell supernatants of hUMSCs were applied to TCs in vitro we found that GSK3β expression was reduced, the imbalance of mitochondrial dynamics was alleviated, and the ability of mitochondrial testosterone synthesis was increased. Taken together, our results indicate that hUMSCs treatment can restore the imbalance of mitochondrial dynamics and restart testosterone synthesis of TCs by suppressing GSK3β expression, ultimately alleviating POI damage.

Abnormalities in copper status associated with diminished ovarian reserve: A case-control and cross-sectional study

OBJECTIVE

This study aimed to illustrate the copper status of diminished ovarian reserve in Chinese women, especially the effects of copper, ceruloplasmin, non-ceruloplasmin-bound copper (NCC) and CuZn superoxide dismutase (SOD1).

METHODS

This case-control, cross-sectional investigation included women with diminished ovarian reserve (DOR group, n = 35) and matched normal ovarian reserve (NOR group, n = 35). The serum levels of copper, ceruloplasmin, NCC, SOD1, follicle-stimulating hormone, luteinizing hormone, estradiol, testosterone, and anti-Müllerian hormone were tested and analyzed.

RESULTS

The serum copper concentrations (60.88%), NCC (54.75%) and SOD1 (54.75%) in the DOR group were significantly higher than those in the NOR group (all P < 0.001), and the concentrations of the three markers were higher in most subgroups (P < 0.001). The correlation analysis verified the correlation between copper status and impaired ovarian function. Additionally, linear regression analysis showed that NCC and SOD1 levels were negatively correlated with anti-Müllerian hormone (P < 0.05 or 0.001).

CONCLUSION

Our exploration found significant increases in copper, NCC and SOD1 levels in DOR and suggests a possible link. Copper status is expected to serve as the predictive marker for DOR.

Exome sequencing reveals pathogenic mutations in the LARS2 and HSD17B4 genes associated with Perrault syndrome and D-bifunctional protein deficiency in Moroccan families

BACKGROUND

Syndromic hearing loss (SHL) is characterized by hearing impairment accompanied by other clinical manifestations, reaching over 400 syndromes. Early and accurate diagnosis is essential to understand the progression of hearing loss and associated systemic complications.

METHODS AND RESULTS

In this study, we investigated the genetic etiology of sensorineural hearing loss in three Moroccan patients using whole exome sequencing (WES). The results revealed in two families Perrault syndrome caused by LARS2, p. Asn153His; p. Thr629Met compound heterozygous variants in two siblings in one family; and p. Thr522Asn, a homozygous variant in two sisters in another. The patient in the third family was diagnosed with D-bifunctional protein deficiency (D-BPD), linked to compound heterozygous mutations p. Asn457Tyr and p. Val643Argfs*5 in HSD17B4. Molecular dynamic simulation results showed that Val643Argfs*5 does not prevent HSD17B4 protein from binding to the PEX5 receptor, but further studies are recommended to verify its effect on HSD17B4 protein functionality.

CONCLUSION

These results highlight the effectiveness of WES in identifying pathogenic mutations involved in heterogeneous disorders and the usefulness of bioinformatics in predicting their effects on protein structure.

Diaph1 knockout inhibits mouse primordial germ cell proliferation and affects gonadal development

BACKGROUND

Exploring the molecular mechanisms of primordial germ cell (PGC) migration and the involvement of gonadal somatic cells in gonad development is valuable for comprehending the origins and potential treatments of reproductive-related diseases.

METHODS

Diaphanous related formin 1 (Diaph1, also known as mDia1) was screened by analyzing publicly available datasets (ATAC-seq, DNase-seq, and RNA-seq). Subsequently, the CRISPR-Cas9 technology was used to construct Diaph1 knockout mice to investigate the role of Diaph1 in gonad development.

RESULTS

Based on data from public databases, a differentially expressed gene Diaph1, was identified in the migration of mouse PGC. Additionally, the number of PGCs was significantly reduced in Diaph1 knockout mice compared to wild type mice, and the expression levels of genes related to proliferation (Dicer1, Mcm9), adhesion (E-cadherin, Cdh1), and migration (Cxcr4, Hmgcr, Dazl) were significantly decreased. Diaph1 knockout also inhibited Leydig cell proliferation and induced apoptosis in the testis, as well as granulosa cell apoptosis in the ovary. Moreover, the sperm count in the epididymal region and the count of ovarian follicles were significantly reduced in Diaph1 knockout mice, resulting in decreased fertility, concomitant with lowered levels of serum testosterone and estradiol. Further research found that in Diaph1 knockout mice, the key enzymes involved in testosterone synthesis (CYP11A1, 3β-HSD) were decreased in Leydig cells, and the estradiol-associated factor (FSH receptor, AMH) in granulosa cells were also downregulated.

CONCLUSIONS

Overall, our findings indicate that the knockout of Diaph1 can disrupt the expression of factors that regulate sex hormone production, leading to impaired secretion of sex hormones, ultimately resulting in damage to reproductive function. These results provide a new perspective on the molecular mechanisms underlying PGC migration and gonadal development, and offer valuable insights for further research on the causes, diagnosis, and treatment of related diseases.

Regulating Lars2 in mitochondria: A potential Alzheimer's therapy by inhibiting tau phosphorylation

Driven by the scarcity of effective treatment options in clinical settings, the present study aimed to identify a new potential target for Alzheimer's disease (AD) treatment. We focused on Lars2, an enzyme synthesizing mitochondrial leucyl-tRNA, and its role in maintaining mitochondrial function. Bioinformatics analysis of human brain transcriptome data revealed downregulation of Lars2 in AD patients compared to healthy controls. During in vitro experiments, the knockdown of Lars2 in mouse neuroblastoma cells (neuro-2a cells) and primary cortical neurons led to morphological changes and decreased density in mouse hippocampal neurons. To explore the underlying mechanisms, we investigated how downregulated Lars2 expression could impede the phosphatidylinositol 3-kinase/protein kinase B (PI3K-AKT) pathway, thereby mitigating AKT's inhibitory effect on glycogen synthase kinase 3 beta (GSK3β). This led to the activation of GSK3β, causing excessive phosphorylation of Tau protein and subsequent neuronal degeneration. During in vivo experiments, knockout of lars2 in hippocampal neurons confirmed cognitive impairment through the Barnes maze test, the novel object recognition test, and nest-building experiments. Additionally, immunofluorescence assays indicated an increase in p-tau, atrophy in the hippocampal region, and a decrease in neurons following Lars2 knockout. Taken together, our findings indicate that Lars2 represents a promising therapeutic target for AD.

Investigating gene signatures associated with immunity in colon adenocarcinoma to predict the immunotherapy effectiveness using NFM and WGCNA algorithms

Colon adenocarcinoma (COAD), a frequently encountered and highly lethal malignancy of the digestive system, has been the focus of intensive research regarding its prognosis. The intricate immune microenvironment plays a pivotal role in the pathological progression of COAD; nevertheless, the underlying molecular mechanisms remain incompletely understood. This study aims to explore the immune gene expression patterns in COAD, construct a robust prognostic model, and delve into the molecular mechanisms and potential therapeutic targets for COAD liver metastasis, thereby providing critical support for individualized treatment strategies and prognostic evaluation. Initially, we curated a comprehensive dataset by screening 2600 immune-related genes (IRGs) from the ImmPort and InnateDB databases, successfully obtaining a rich data resource. Subsequently, the COAD patient cohort was classified using the non-negative matrix factorization (NMF) algorithm, enabling accurate categorization. Continuing on, utilizing the weighted gene co-expression network analysis (WGCNA) method, we analyzed the top 5000 genes with the smallest p-values among the differentially expressed genes (DEGs) between immune subtypes. Through this rigorous screening process, we identified the gene modules with the strongest correlation to the COAD subpopulation, and the intersection of genes in these modules with DEGs (COAD vs COAD vs Normal colon tissue) is referred to as Differentially Expressed Immune Genes Associated with COAD (DEIGRC). Employing diverse bioinformatics methodologies, we successfully developed a prognostic model (DPM) consisting of six genes derived from the DEIGRC, which was further validated across multiple independent datasets. Not only does this predictive model accurately forecast the prognosis of COAD patients, but it also provides valuable insights for formulating personalized treatment regimens. Within the constructed DPM, we observed a downregulation of CALB2 expression levels in COAD tissues, whereas NOXA1, KDF1, LARS2, GSR, and TIMP1 exhibited upregulated expression levels. These genes likely play indispensable roles in the initiation and progression of COAD and thus represent potential therapeutic targets for patient management. Furthermore, our investigation into the molecular mechanisms and therapeutic targets for COAD liver metastasis revealed associations with relevant processes such as fat digestion and absorption, cancer gene protein polysaccharides, and nitrogen metabolism. Consequently, genes including CAV1, ANXA1, CPS1, EDNRA, and GC emerge as promising candidates as therapeutic targets for COAD liver metastasis, thereby providing crucial insights for future clinical practices and drug development. In summary, this study uncovers the immune gene expression patterns in COAD, establishes a robust prognostic model, and elucidates the molecular mechanisms and potential therapeutic targets for COAD liver metastasis, thereby possessing significant theoretical and clinical implications. These findings are anticipated to offer substantial support for both the treatment and prognosis management of COAD patients.

Protective effect of bioactive components from Rubi fructus against oxidative damage in human ovarian granulosa cells induced by 2,2-azobis (2-methylpropionamidine) dihydrochloride

BACKGROUND

Diminished ovarian reserve has a serious impact on female reproduction with an increasing incidence every year. An important cause of this is oxidative stress. Rubi fructus, a traditional medicinal and edible plant, has shown therapeutic effects against gynecological diseases. Vanillic acid, isoquercitrin, kaempferol-3-O-rutinoside, kaempferol-3-O-sophoroside, oleanolic acid, tormentic acid, tiliroside, and ellagic acid are the major bioactive components in R. fructus. However, studies involved in the effectiveness and mechanism of these components in oxidative stress-induced ovarian dysfunction are scarce.

RESULTS

In this study, the protective mechanisms of the bioactive components were evaluated in human ovarian granulosa cells. Isoquercitrin was significantly superior to other bioactive components in relieving damage in human ovarian granulosa cells induced by 2,2-azobis (2-methylpropionamidine) dihydrochloride, considering enhanced cell viability, reduced reactive oxygen species accumulation, and improved mitochondrial membrane potential level. Isoquercitrin protected human ovarian granulosa cells from oxidative stress by regulating the enzyme activity of glutathione peroxidase, inhibiting cell apoptosis, improving the expression of genes related to oxidative stress, and ameliorating heme oxygenase 1 protein expression.

CONCLUSION

Isoquercitrin, a bioactive component in R. fructus, has a significant protective effect on oxidative damage induced by 2,2-azobis (2-methylpropionamidine) dihydrochloride in human ovarian granulosa cells, providing evidence for its potential application in protecting ovarian function. © 2024 Society of Chemical Industry.

Distal colonocytes targeted by C. rodentium recruit T-cell help for barrier defence

Interleukin 22 (IL-22) has a non-redundant role in immune defence of the intestinal barrier1-3. T cells, but not innate lymphoid cells, have an indispensable role in sustaining the IL-22 signalling that is required for the protection of colonic crypts against invasion during infection by the enteropathogen Citrobacter rodentium4 (Cr). However, the intestinal epithelial cell (IEC) subsets targeted by T cell-derived IL-22, and how T cell-derived IL-22 sustains activation in IECs, remain undefined. Here we identify a subset of absorptive IECs in the mid-distal colon that are specifically targeted by Cr and are differentially responsive to IL-22 signalling. Major histocompatibility complex class II (MHCII) expression by these colonocytes was required to elicit sustained IL-22 signalling from Cr-specific T cells, which was required to restrain Cr invasion. Our findings explain the basis for the regionalization of the host response to Cr and demonstrate that epithelial cells must elicit MHCII-dependent help from IL-22-producing T cells to orchestrate immune protection in the intestine.

How Mycobacterium tuberculosis builds a home: Single-cell analysis reveals M. tuberculosis ESX-1-mediated accumulation of anti-inflammatory macrophages in infected mouse lungs

Mycobacterium tuberculosis (MTB) infects and replicates in lung mononuclear phagocytes (MNPs) with astounding ability to evade elimination. ESX-1, a type VII secretion system, acts as a virulence determinant that contributes to MTB's ability to survive within MNPs, but its effect on MNP recruitment and/or differentiation remains unknown. Here, using single-cell RNA sequencing, we studied the role of ESX-1 in MNP heterogeneity and response in mice and murine bone marrow-derived macrophages (BMDM). We found that ESX-1 is required for MTB to recruit diverse MNP subsets with high MTB burden. Further, MTB induces an anti-inflammatory signature in MNPs and BMDM in an ESX-1 dependent manner. Similarly, spatial transcriptomics revealed an upregulation of anti-inflammatory signals in MTB lesions, where monocyte-derived macrophages concentrate near MTB-infected cells. Together, our findings suggest that MTB ESX-1 mediates the recruitment and differentiation of anti-inflammatory MNPs, which MTB can infect and manipulate for survival.

A Comprehensive Prognostic Model for Colon Adenocarcinoma Depending on Nuclear-Mitochondrial-Related Genes

Background: Colon adenocarcinoma (COAD) has increasing incidence and is one of the most common malignant tumors. The mitochondria involved in cell energy metabolism, oxygen free radical generation, and cell apoptosis play important roles in tumorigenesis and progression. The relationship between mitochondrial genes and COAD remains largely unknown. Methods: COAD data including 512 samples were set out from the UCSC Xena database. The nuclear mitochondrial-related genes (NMRGs)-related risk prognostic model and prognostic nomogram were constructed, and NMRGs-related gene mutation and the immune environment were analyzed using bioinformatics methods. Then, a liver metastasis model of colorectal cancer was constructed and protein expression was detected using Western blot assay. Results: A prognostic model for COAD was constructed. Comparing the prognostic model dataset and the validation dataset showed considerable correlation in both risk grouping and prognosis. Based on the risk score (RS) model, the samples of the prognostic dataset were divided into high risk group and low risk group. Moreover, pathologic N and T stage and tumor recurrence in the two risk groups were significantly different. The four prognostic factors, including age and pathologic T stage in the nomogram survival model also showed excellent predictive performance. An optimal combination of nine differentially expressed NMRGs was finally obtained, including LARS2, PARS2, ETHE1, LRPPRC, TMEM70, AARS2, ACAD9, VARS2, and ATP8A2. The high-RS group had more inflamed immune features, including T and CD4+ memory cell activation. Besides, mitochondria-associated LRPPRC and LARS2 expression levels were increased in vivo xenograft construction and liver metastases assays. Conclusion: This study established a comprehensive prognostic model for COAD, incorporating nine genes associated with nuclear-mitochondrial functions. This model demonstrates superior predictive performance across four prognostic factors: age, pathological T stage, tumor recurrence, and overall prognosis. It is anticipated to be an effective model for enhancing the prognosis and treatment of COAD.

MFN2 regulates progesterone biosynthesis and proliferation of granulosa cells during follicle selection in hens

Follicle selection in hens refers to a biological process that only one small yellow follicle (SYF) is selected daily or near-daily for following hierarchical development (from F5/F6 to F1) until ovulation. MFN2 is a kind of GTPases located on the mitochondrial outer membrane, which plays a crucial role in mitochondrial fusion. This study aimed to elucidate the role of MFN2 in proliferation and progesterone biosynthesis of granulosa cells (GCs) during follicle selection in hens. The results showed that GCs began to produce progesterone (P4) after follicle selection, accompanied with changes from multi-layer with flat cells to single layer with cubic cells. MFN2 was detected in GCs of follicles from SYF to F1. After follicle selection, the expression level of MFN2 in GCs upregulated significantly, accompanied with increases in P4 biosynthesis, ATP production, mitochondrial DNA (mtDNA) copy numbers of granulosa cells. FSH (80 ng/mL) facilitated the effects of P4 biosynthesis and secretion, ATP production, mtDNA copy numbers, cell proliferation and the MFN2 transcription of granulosa cells from F5 (F5G) in vitro. However, FSH treatment did not promote P4 secretion in granulosa cells from SYF (SYFG) in vitro. Meanwhile, we observed that change fold of MFN2 transcription, ATP production, mtDNA copy numbers and cell proliferation rate in F5G after treatment with FSH were greater than those in SYFG. Furthermore, expression levels of MFN2 protein and messenger RNA in F5G were significantly higher than those in SYFG after treatment with FSH. P4 biosynthesis, ATP production, mtDNA copy numbers as well as cell proliferation reduced significantly in F5G with MFN2 knockdown. Oppositely, P4 biosynthesis, ATP production, mtDNA copy numbers and cell proliferation increased significantly in SYFG after the overexpression of MFN2. Our results suggest that the upregulation of MFN2 may be involved in the initiation of P4 biosynthesis, and promotion of GCs proliferation during follicle selection.

A single-cell atlas of immunocytes in the spleen of a mouse model of Wiskott-Aldrich syndrome

Wiskott-Aldrich syndrome (WAS) is a disorder characterized by rare X-linked genetic immune deficiency with mutations in the Was gene, which is specifically expressed in hematopoietic cells. The spleen plays a major role in hematopoiesis and red blood cell clearance. However, to date, comprehensive analyses of the spleen in wild-type (WT) and WASp-deficient (WAS-KO) mice, especially at the transcriptome level, have not been reported. In this study, single-cell RNA sequencing (scRNA-seq) was adopted to identify various types of immune cells and investigate the mechanisms underlying immune deficiency. We identified 30 clusters and 10 major cell subtypes among 11,269 cells; these cell types included B cells, T cells, dendritic cells (DCs), natural killer (NK) cells, monocytes, macrophages, granulocytes, stem cells and erythrocytes. Moreover, we evaluated gene expression differences among cell subtypes, identified differentially expressed genes (DEGs), and performed enrichment analyses to identify the reasons for the dysfunction in these different cell populations in WAS. Furthermore, some key genes were identified based on a comparison of the DEGs in each cell type involved in specific and nonspecific immune responses, and further analysis showed that these key genes were previously undiscovered pathology-related genes in WAS-KO mice. In summary, we present a landscape of immune cells in the spleen of WAS-KO mice based on detailed data obtained at single-cell resolution. These unprecedented data revealed the transcriptional characteristics of specific and nonspecific immune cells, and the key genes were identified, laying a foundation for future studies of WAS, especially studies into novel and underexplored mechanisms that may improve gene therapies for WAS.

Melatonin-Mediated Suppression of mtROS-JNK-FOXO1 Pathway Alleviates Hypoxia-Induced Apoptosis in Porcine Granulosa Cells

Numerous studies have established that the hypoxic conditions within ovarian follicles induce apoptosis in granulosa cells (GCs), a pivotal hallmark of follicular atresia. Melatonin (N-acetyl-5-methoxytryptamine, MT), a versatile antioxidant naturally present in follicular fluid, acts as a safeguard for maintaining GCs' survival during stress exposure. In this study, we unveil an innovative protective mechanism of melatonin against hypoxia-triggered GC apoptosis by selectively inhibiting mitochondrial ROS (mtROS) generation. Specifically, under hypoxic conditions, a gradual accumulation of mitochondrial ROS occurred, consequently activating the JNK-FOXO1 pathway, and driving GCs toward apoptosis. The blocking of JNK or FOXO1 diminished hypoxia-induced GC apoptosis, but this effect was nullified in the presence of GSH, indicating that mtROS instigates apoptosis through the JNK-FOXO1 pathway. Consistent with this, hypoxic GCs treated with melatonin exhibited decreased levels of mtROS, reduced JNK-FOXO1 activation, and mitigated apoptosis. However, the protective capabilities of melatonin were attenuated upon inhibiting its receptor MTNR1B, accompanied by the decreased expression of antioxidant genes. Notably, SOD2, a key mitochondrial antioxidant gene modulated by the melatonin-MTNR1B axis, effectively inhibited the activation of mtROS-JNK-FOXO1 and subsequent apoptosis, whereas SOD2 knockdown abrogated the protective role of melatonin in hypoxic GCs. In conclusion, our study elucidates that melatonin, through MTNR1B activation, fosters SOD2 expression, effectively quelling mtROS-JNK-FOXO1-mediated apoptosis in follicular GCs under hypoxic stress.

Berberine protects cyclophosphamide and busulfan-induced premature ovarian insufficiency in mouse model

Premature ovarian insufficiency (POI) is a clinical syndrome that declines ovarian function in women. Berberine (BBR) is a compound with anti-inflammatory, antioxidant, and anti-apoptotic activities. However, the role of BBR on POI is still unknown. In this study, we investigated the role of BBR on ovarian function decline by establishing a POI mouse model using cyclophosphamide (CTX) and busulfan (BU). Our results showed that POI was attenuated by BBR, which was evidenced by enhanced body weight and ovarian weight, improved morphology of ovary, increased the number of healthy follicles, decreased the production of atretic follicles and restored serum hormone levels, including estradiol, anti-Müllerian hormone and follicle-stimulating hormone. In addition, we showed that germ cell function markers, mouse vasa homologue (MVH) and octamer-binding transcription factor 4 (OCT4) were enhanced by BBR, at both protein and mRNA levels. Furthermore, our results revealed that BBR inhibited inflammation and oxidative stress by reducing nuclear factor kappa B (NF-κB) and enhancing nuclear factor erythroid 2-related factor 2 (Nrf2) pathways. Taken together, we demonstrate that BBR can effectively improve ovarian function in POI mice, which is mainly mediated by reducing oxidative stress and inflammatory response. Our study also provides new strategy for POI treatment.

Beyond apoptosis: evidence of other regulated cell death pathways in the ovary throughout development and life

BACKGROUND

Regulated cell death is a fundamental component of numerous physiological processes; spanning from organogenesis in utero, to normal cell turnover during adulthood, as well as the elimination of infected or damaged cells throughout life. Quality control through regulation of cell death pathways is particularly important in the germline, which is responsible for the generation of offspring. Women are born with their entire supply of germ cells, housed in functional units known as follicles. Follicles contain an oocyte, as well as specialized somatic granulosa cells essential for oocyte survival. Follicle loss-via regulated cell death-occurs throughout follicle development and life, and can be accelerated following exposure to various environmental and lifestyle factors. It is thought that the elimination of damaged follicles is necessary to ensure that only the best quality oocytes are available for reproduction.

OBJECTIVE AND RATIONALE

Understanding the precise factors involved in triggering and executing follicle death is crucial to uncovering how follicle endowment is initially determined, as well as how follicle number is maintained throughout puberty, reproductive life, and ovarian ageing in women. Apoptosis is established as essential for ovarian homeostasis at all stages of development and life. However, involvement of other cell death pathways in the ovary is less established. This review aims to summarize the most recent literature on cell death regulators in the ovary, with a particular focus on non-apoptotic pathways and their functions throughout the discrete stages of ovarian development and reproductive life.

SEARCH METHODS

Comprehensive literature searches were carried out using PubMed and Google Scholar for human, animal, and cellular studies published until August 2022 using the following search terms: oogenesis, follicle formation, follicle atresia, oocyte loss, oocyte apoptosis, regulated cell death in the ovary, non-apoptotic cell death in the ovary, premature ovarian insufficiency, primordial follicles, oocyte quality control, granulosa cell death, autophagy in the ovary, autophagy in oocytes, necroptosis in the ovary, necroptosis in oocytes, pyroptosis in the ovary, pyroptosis in oocytes, parthanatos in the ovary, and parthanatos in oocytes.

OUTCOMES

Numerous regulated cell death pathways operate in mammalian cells, including apoptosis, autophagic cell death, necroptosis, and pyroptosis. However, our understanding of the distinct cell death mediators in each ovarian cell type and follicle class across the different stages of life remains the source of ongoing investigation. Here, we highlight recent evidence for the contribution of non-apoptotic pathways to ovarian development and function. In particular, we discuss the involvement of autophagy during follicle formation and the role of autophagic cell death, necroptosis, pyroptosis, and parthanatos during follicle atresia, particularly in response to physiological stressors (e.g. oxidative stress).

WIDER IMPLICATIONS

Improved knowledge of the roles of each regulated cell death pathway in the ovary is vital for understanding ovarian development, as well as maintenance of ovarian function throughout the lifespan. This information is pertinent not only to our understanding of endocrine health, reproductive health, and fertility in women but also to enable identification of novel fertility preservation targets.

Comparative transcriptome and proteome analysis explores the antitumor key regulators of ergosterone in H22 tumor-bearing mice

Ergosterone has been proved to have potential antitumor effect on H22 tumor-bearing mice, but the antitumor mechanism and key regulators are still unclear. The current study was aimed to explore the key regulators responsible for antitumor of ergosterone using whole transcriptome and proteome analysis in H22 tumor-bearing mice model. The model of H22 tumor-bearing mice was constructed according to the histopathological data and biochemical parameters. The isolated tumor tissues of different treatment groups were subjected to transcriptomic and proteomic analysis. Our findings demonstrated that 472 differentially expressed genes and 658 proteins were identified in the tumor tissue of different treatment groups through RNA-Seq and liquid chromatography with tandem mass spectrometry-based proteomic analysis, respectively. The combined omics analysis revealed three critical genes/proteins, including Lars2, Sirpα and Hcls1 that could play a role in antitumor pathways. Furthermore, Lars2, Sirpα and Hcls1 genes/proteins, as key regulators of the antitumor effect of ergosterone, were verified by qRT-PCR and western blotting methods, respectively. In summary, our study provides new insights into analysing the antitumor mechanism of ergosterone from the point of view of gene and protein expression and will encourage further development of the antitumor pharmaceutical industry.

Mitocytosis Is Critical for Phthalate-Induced Injury to the Ovarian Granulosa Cell Layer in Quail (Coturnix japonica)

Phthalates are widely used synthetic chemicals that determine endocrine disruption effects on female reproductivity and oviposition. Our study demonstrated that the mitochondrial quality in ovarian granulosa cells (GCs) is associated with a poor prognosis in female reproduction. However, the molecular mechanism of di-(2-ethylhexyl) phthalate (DEHP) exposure on the quail ovarian GC layer is still unknown. To validate the effects of DEHP on the GC layer, 8 days' old 150 female Japanese quail were treated orally with DEHP (250, 500, and 750 mg/kg BW/day) for 45 days to explore the toxic effects of DEHP on the ovarian GC layer. Histopathological assessment and ultrastructure observation found that DEHP decreased the thickness of the GC layer, resulted in mitochondrial damage, and activated mitocytosis. Additionally, the results further suggested that DEHP impacted the secretion of steroid hormones (reduced FSH, E2, and T levels and boosted Prog, PRL, and LH levels) by triggering mitocytosis (enhanced transcription of MYO19 and protein of KIF5B levels), mitochondrial dynamics (increasing mRNA and protein levels of OPA1, DRP1, MFN1, and MFN2), mitophagy (increasing mRNA and protein levels of Parkin, LC3B, and P62), and inducing GC function disorder. In conclusion, our research provided a new idea to explain the mechanism of DEHP toxicity of the ovarian GC layer in quail and presented insights into the role of mitocytosis in DEHP-induced ovarian GC layer injury.

Chronic stress targets mitochondrial respiratory efficiency in the skeletal muscle of C57BL/6 mice

Episodes of chronic stress can result in psychic disorders like post-traumatic stress disorder, but also promote the development of metabolic syndrome and type 2 diabetes. We hypothesize that muscle, as main regulator of whole-body energy expenditure, is a central target of acute and adaptive molecular effects of stress in this context. Here, we investigate the immediate effect of a stress period on energy metabolism in Musculus gastrocnemius in our established C57BL/6 chronic variable stress (Cvs) mouse model. Cvs decreased lean body mass despite increased energy intake, reduced circadian energy expenditure (EE), and substrate utilization. Cvs altered the proteome of metabolic components but not of the oxidative phosphorylation system (OXPHOS), or other mitochondrial structural components. Functionally, Cvs impaired the electron transport chain (ETC) capacity of complex I and complex II, and reduces respiratory capacity of the ETC from complex I to ATP synthase. Complex I-OXPHOS correlated to diurnal EE and complex II-maximal uncoupled respiration correlated to diurnal and reduced nocturnal EE. Bioenergetics assessment revealed higher optimal thermodynamic efficiencies (ƞ-opt) of mitochondria via complex II after Cvs. Interestingly, transcriptome and methylome were unaffected by Cvs, thus excluding major contributions to supposed metabolic adaptation processes. In summary, the preclinical Cvs model shows that metabolic pressure by Cvs is initially compensated by adaptation of mitochondria function associated with high thermodynamic efficiency and decreased EE to manage the energy balance. This counter-regulation of mitochondrial complex II may be the driving force to longitudinal metabolic changes of muscle physiological adaptation as the basis of stress memory.

Selected Genetic Factors Associated with Primary Ovarian Insufficiency

Primary ovarian insufficiency (POI) is a heterogeneous disease resulting from non-functional ovaries in women before the age of 40. It is characterized by primary amenorrhea or secondary amenorrhea. As regards its etiology, although many POI cases are idiopathic, menopausal age is a heritable trait and genetic factors play an important role in all POI cases with known causes, accounting for approximately 20% to 25% of cases. This paper reviews the selected genetic causes implicated in POI and examines their pathogenic mechanisms to show the crucial role of genetic effects on POI. The genetic factors that can be found in POI cases include chromosomal abnormalities (e.g., X chromosomal aneuploidies, structural X chromosomal abnormalities, X-autosome translocations, and autosomal variations), single gene mutations (e.g., newborn ovary homeobox gene (NOBOX), folliculogenesis specific bHLH transcription factor (FIGLA), follicle-stimulating hormone receptor (FSHR), forkhead box L2 (FOXL2), bone morphogenetic protein 15 (BMP15), etc., as well as defects in mitochondrial functions and non-coding RNAs (small ncRNAs and long ncRNAs). These findings are beneficial for doctors to diagnose idiopathic POI cases and predict the risk of POI in women.

Moxibustion mitigates mitochondrial dysfunction and NLRP3 inflammatory activation in cyclophosphamide-induced premature ovarian insufficiency rats

AIMS

This study aimed to investigate the protective effects of moxibustion on ovarian dysfunction in rats with cyclophosphamide (Cy)-induced premature ovarian insufficiency (POI). It also aimed at revealing its potential mechanisms and emphasizing its role in mitigating the mitochondrial dysfunction and NLRP3 inflammatory activation.

MATERIALS AND METHODS

POI models were established by the intraperitoneal administration of Cy using female Sprague-Dawley rats. Moxibustion (BL23 or CV4, CV8) was used to treat POI models for fifteen days. Vaginal smears, enzyme-linked immunosorbent assay, hematoxylin-eosin, tunnel staining, flow cytometry analysis, immunohistochemistry staining, qRT-PCR, and western blotting were conducted to evaluate the ovarian function, mitochondrial dysfunction, and NLRP3 inflammatory activation in this study.

KEY FINDINGS

Moxibustion could improve the disorder of the estrous cycles and reproductive hormone levels, promote follicular growth, reduce the number of atresia follicles, and alleviate the apoptosis of ovarian granulosa cells (GCs) in rats with POI. Furthermore, moxibustion mitigated the mitochondrial damage, reversed the elevated serum levels of IL-18 and IL-1β, and decreased their protein expression in the ovaries of rats with POI. Moxibustion significantly inhibited the expression of the mRNAs and proteins of NOD-like receptor thermal protein domain-associated protein 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), caspase 1, and gasdermin D (GSDMD) in the ovaries of rats with POI.

SIGNIFICANCE

These results supported that moxibustion may ameliorate Cy-induced POI by mitigating the mitochondrial dysfunction and NLRP3 inflammatory activation. Targeted treatment of mitochondrial damage and NLRP3 inflammatory activation may be a novel therapeutic strategy for POI.

Hydrogen sulfide plays an important role by regulating endoplasmic reticulum stress in myocardial diseases

Endoplasmic reticulum (ER) is an important organelle for protein translation, folding and translocation, as well as the post-translational modification and assembly of newly synthesized secreted proteins. When the excessive accumulation of misfolded and/or unfolded proteins exceeds the processing capacity of ER, ER stress is triggered. The integrated intracellular signal cascade, namely the unfolded protein response, is induced to avoid ER stress. ER stress is involved in many pathological and physiological processes including myocardial diseases. For a long time, hydrogen sulfide (H₂S) has been considered as a toxic gas with the smell of rotten eggs. However, more and more evidences indicate that H₂S is an important gas signal molecule after nitric oxide and carbon monoxide, and regulates a variety of physiological and pathological processes in mammals. In recent years, increasing studies have focused on the regulatory effects of H₂S on ER stress in myocardial diseases, however, the mechanism is not very clear. Therefore, this review focuses on the role of H₂S regulation of ER stress in myocardial diseases, and deeply analyzes the relevant mechanisms so as to lay the foundation for the future researches.

Shaoyao-Gancao Decoction Promoted Microglia M2 Polarization via the IL-13-Mediated JAK2/STAT6 Pathway to Alleviate Cerebral Ischemia-Reperfusion Injury

Microglia in the penumbra shifted from M2 to M1 phenotype between 3 and 5 days after cerebral ischemia-reperfusion, which promoted local inflammation and injury. Shaoyao-Gancao Decoction (SGD) has been found to result in a significant upregulation of IL-13 in the penumbra, which has been shown to induce polarization of M2 microglia. There was thus a hypothesis that SGD could exert an anti-inflammatory and neuroprotective effect by activating IL-13 to induce microglia polarization towards M2 phenotype, and the purpose of this study was to explore the influence of SGD on microglia phenotype switching and its possible mechanism. Rats who received middle cerebral artery occlusion surgery (MCAO) were treated with SGD for 3 or 6 days, to investigate the therapeutic effect and the underlying mechanism of SGD for cerebral ischemia-reperfusion injury (CI/RP). The results indicated that SGD improved neurobehavioral scores and reduced apoptosis. Furthermore, SGD significantly decreased M1 microglia and M1-like markers, but increased M2 microglia and M2 markers. Moreover, higher levels of IL-13 and ratios of p-JAK2/JAK2 and p-STAT6/STAT6 were found in the SGD group compared to the MCAO. In conclusion, it was verified that SGD prevented injury by driving microglia phenotypic switching from M1 to M2, probably via IL-13 and its downstream JAK2-STAT6 pathway. Given that no further validation tests were included in this study, it is necessary to conduct more experiments to confirm the reliability of the above results.