Mitochondria in Ovarian Aging and Reproductive Longevity

Exploring potential pathways from oxidative stress to ovarian aging

AIM

In developed nations, women have increasingly deferred childbearing, leading to a rise in demand for infertility treatments and the widespread use of assisted reproductive technologies. However, despite advancements in in vitro fertilization (IVF), live birth rates among women over 40 remain suboptimal. Mitochondrial dysfunction is widely recognized as a key factor in the processes driving the age-related deterioration in both the quantity and quality of oocytes. We aim to summarize current insights into ovarian aging, with a particular focus on pathways that impair mitochondrial function, and explore directions for future research.

METHODS

Electronic databases were searched for articles published up to June 30, 2024.

RESULTS

Ongoing ovulation, luteolysis, and menstruation trigger exogenous reactive oxygen species (ROS)-mediated oxidative stress that damages mitochondrial DNA. This, in turn, reduces nuclear gene expression, compromises mitochondrial oxidative phosphorylation, and diminishes adenosine 5' triphosphate production. Persistent endogenous ROS further exacerbate mitochondrial DNA damage and aneuploidy, ultimately causing irreversible chromosomal abnormalities, leading to oocyte aging.

CONCLUSIONS

We have delineated the pathway from oxidative stress to ovarian aging. Early detection and management of ovarian aging present challenges and opportunities to enhance IVF treatment strategies.

Altered mitochondrial homeostasis on bisphenol-A exposure and its association in developing polycystic ovary syndrome: A comprehensive review

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrinopathy that is known to be one of the most common reproductive pathologies observed in premenopausal women around the globe and is particularly complex as it affects various endocrine and reproductive metabolic pathways. Endocrine-disrupting chemicals (EDCs) are considered to be environmental toxicants as they have hazardous health effects on the functioning of the human endocrine system. Among various classes of EDCs, bisphenol A (BPA) has been under meticulous investigation due to its ability to alter the endocrine processes. As there is emerging evidence suggesting that BPA-induced mitochondrial homeostasis dysfunction in various pathophysiological conditions, this review aims to provide a detailed review of how various pathways associated with ovarian mitochondrial homeostasis are impaired on BPA exposure and its mirroring effects on the PCOS phenotype. BPA exposure might cause significant damage to the mitochondrial morphology and functions through the generation of reactive oxygen species (ROS) and simultaneously downregulates the total antioxidant capacity, thereby leading to oxidative stress. BPA disrupts the mitochondrial dynamics in human cells by altering the expressions of mitochondrial fission and fusion genes, increases the senescence marker proteins, along with significant alterations in the mTOR/AMPK pathway, upregulates the expression of autophagy mediating factors, and downregulates the autophagic suppressor. Furthermore, an increase in apoptosis of the ovarian granulosa cells indicates impaired folliculogenesis. As all these key features are associated with the pathogenesis of PCOS, this review can provide a better insight into the possible associations between BPA-induced dysregulation of mitochondrial homeostasis and PCOS.

Curcumin mitigates sodium fluoride toxicity in Caenorhabditis elegans

Fluoride, a naturally occurring element found in water, soil, food, and atmospheric precipitation, can lead to fluorosis and various health issues when consumed excessively. However, the mechanism of fluorosis is still under investigation. This study utilizes Caenorhabditis elegans as a model organism to investigate the effects of fluoride exposure on biological systems and to explore the mechanisms by which curcumin mitigates fluoride-induced toxicity. Three groups were established: a blank control, a sodium fluoride (NaF) exposure group (concentration 5 mmol/L), and a curcumin intervention group (concentration 25 μmol/L). Physiological parameters, lipofuscin levels, intracellular reactive oxygen species (ROS) levels, mitochondrial membrane potential, and mitochondrial copy numbers were measured to assess the effects of fluoride toxicity and curcumin protection. RNA-seq and qRT-PCR were utilized to investigate the molecular mechanisms underlying fluoride-induced damage and curcumin's mitigating effects. Results indicated that fluoride-exposed nematodes displayed physiological abnormalities, increased ROS production, higher lipofuscin levels, altered mitochondrial membrane potential and mitochondrial copy number, and activated MAPK signaling pathway genes. Curcumin exhibited protective effects on these parameters, suggesting its potential in preventing fluoride-induced harm by modulating oxidative stress and preserving mitochondrial function. This research enhances our understanding of the mechanisms of fluoride toxicity and highlights the potential benefits of curcumin.

Maternal swimming with overload allied to postnatal high-fat, high-sugar diet induce subtle impairment on rat offspring's ovarian redox homeostasis

Context The Developmental Origins of Health and Disease (DOHaD) concept suggests that early-life interventions significantly influence the long-term health outcomes of offspring. Emerging evidence supports that maternal physical exercise and balanced nutrition can positively impact the health of the next generation. Aims This study investigated the effects of maternal swimming combined with postnatal high-fat, high-sugar (HFHS) diet on the ovarian health of adult female Wistar rat offspring. Methods Adult female Wistar rats performed swimming exercise in a controlled temperature environment (32°C, 2% bodyweight overload adjusted daily) during 4weeks, starting 1week prior mating. The female offspring received a control or HFHS diet from postnatal day (PND) 21 to PND 90. We analyzed offspring's body weight, ovarian histomorphology, redox status, and associated molecular pathways 5' adenosine monophosphate-activated protein kinase (AMPKα), forkhead box O3 (FoxO3), and mitofusin 1 (Mfn-1). Key results Our findings reveal that maternal swimming exerted an effect on offspring body weight gain, delaying it. Individually, maternal exercise reduced superoxide dismutase (SOD) activity and mitofusin-1 levels, while the postnatal HFHS diet alone decreased both SOD and glutathione peroxidase (GPx) activities and increased the pFOXO3a/FOXO3a ratio in the ovaries. Conclusions We showed that combination of maternal swimming with a 2% overload and a postnatal HFHS diet can negatively affect the ovarian redox balance in offspring. Implications Prenatal and postnatal lifestyle might affect reproductive function in females.

Acrolein exposure affects ovarian function by interfering with glycolysis and mitochondrial energy metabolism in mouse

Acrolein is a widespread contaminant found in both diet and environment, entering the human body through food, alcohol, smoking, and exposure to fuel combustion fumes. While prior studies have highlighted acrolein's harmful impact on oocyte quality and early embryonic development in vitro, the specific mechanisms by which acrolein affects the female reproductive system in vivo remain poorly understood. This study first confirmed that in vitro acrolein exposure disrupts spindle morphology and chromosome alignment during the mid-MI stage of oocyte development, thus hindering oocyte maturation. Besides, exposure to acrolein not only stunts growth in mice but also impairs ovarian development, decreases the ovarian coefficient, disrupts follicular development, and increases the count of atretic follicles in vivo. Additional research has shown that acrolein exposure reduces the activity of key enzymes in glycolysis, pyruvate metabolism, and the tricarboxylic acid cycle within the ovaries. It also suppresses mitochondrial complex expression and disturbs the balance between mitochondrial fission and fusion, as confirmed by metabolomic analyses. Moreover, acrolein exposure in vivo induced granulosa cell apoptosis and reduced oocyte number. In summary, acrolein exposure impairs glucose metabolism and induces mitochondrial dysfunction in the ovaries.

Mitochondria: the epigenetic regulators of ovarian aging and longevity

Ovarian aging is a major health concern for women. Ovarian aging is associated with reduced health span and longevity. Mitochondrial dysfunction is one of the hallmarks of ovarian aging. In addition to providing oocytes with optimal energy, the mitochondria provide a co-substrate that drives epigenetic processes. Studies show epigenetic alterations, both nuclear and mitochondrial contribute to ovarian aging. Both, nuclear and mitochondrial genomes cross-talk with each other, resulting in two ways orchestrated anterograde and retrograde response that involves epigenetic changes in nuclear and mitochondrial compartments. Epigenetic alterations causing changes in metabolism impact ovarian function. Key mitochondrial co-substrate includes acetyl CoA, NAD+, ATP, and α-KG. Thus, enhancing mitochondrial function in aging ovaries may preserve ovarian function and can lead to ovarian longevity and reproductive and better health outcomes in women. This article describes the role of mitochondria-led epigenetics involved in ovarian aging and discusses strategies to restore epigenetic reprogramming in oocytes by preserving, protecting, or promoting mitochondrial function.

Genetic Landscape of a Cohort of 120 Patients with Diminished Ovarian Reserve: Correlation with Infertility

Diminished ovarian reserve (DOR) and primary ovarian insufficiency (POI) are major causes of female infertility. We recently found a monogenic etiology in 29.3% of POI, leading to personalized medicine. The genetic landscape of DOR is unknown. A prospective study (2018-2023) of an international cohort of 120 patients with unexplained DOR was performed using a large custom targeted next-generation sequencing panel including all known POI-causing genes. The diagnostic yield, based on the American College of Medical Genetics, was 24, 2%. Genes belong to different pathways: metabolism and mitochondria (29.7%), follicular growth (24.3%), DNA repair/meiosis (18.9%), aging (16.2%), ovarian development (8.1%), and autophagy (2.7%). Five genes were recurrently found: LMNA, ERCC6, SOX8, POLG, and BMPR1B. Six genes identified in single families with POI were involved in DOR, GNAS, TGFBR3, XPNPEP2, EXO1, BNC1, ATG, highlighting their role in maintaining ovarian reserve. In our cohort, 26 pregnancies were recorded, but no pregnancy was observed when meiosis/DNA repair genes were involved, suggesting severely impaired oocyte quality. Additional studies should confirm these preliminary results. This study with a large NGS panel defines the genetic landscape of a large cohort of DOR. It supports routine genetic diagnosis. Genetics could be a biomarker predicting infertility and progression to POI.

Methylmercury chloride inhibits meiotic maturation of mouse oocytes in vitro by disrupting the cytoskeleton

Methylmercury chloride (MMC) is a persistent heavy metal contaminant that can bioaccumulate in humans via the food chain, exerting detrimental effects on health. Nevertheless, the specific influence of MMC on oocyte meiotic maturation has yet to be elucidated. This research demonstrated that MMC exposure during the in vitro cultivation of mouse oocytes did not influence germinal vesicle breakdown but markedly decreased oocyte maturation rates. Subsequent analysis indicated that MMC exposure resulted in aberrant spindle morphology and disorganized chromosome alignment, alongside continuous activation of the spindle assembly checkpoint (SAC). However, MMC exposure didn't alter the localization pattern of microtubule-organizing center-associated proteins. MMC exposure considerably diminished the acetylation level of α-tubulin, signifying reduced microtubule stability. Additionally, MMC exposure disrupted the dynamic alterations of F-actin. MMC exposure didn't affect mitochondrial localization, mitochondrial membrane potential, adenosine triphosphate content or the concentrations of reactive oxygen species. Nonetheless, MMC exposure triggered DNA damage and modified histone modification levels. Consequently, the defects in oocyte maturation induced by MMC exposure can be attributed to impaired cytoskeleton dynamics and DNA damage. This study offers the first comprehensive elucidation of the negative impacts of MMC on oocyte maturation, highlighting the potential reproductive health risks associated with MMC exposure.

Photobiomodulation ameliorates ovarian aging by alleviating oxidative stress and inflammation damage and improving mitochondrial function

Ovarian aging is a serious clinical concern. Few safe and effective methods are currently available to improve ovarian functions. Photobiomodulation (PBM) is a safe and noninvasive physical therapy that can modulate a series of biological processes. Recently, several studies have noted its potential to improve the function of ovary and reproductive cells. However, the effects of PBM treatment on natural ovarian aging remain unclear. In this study, we used a naturally reproductive aging mouse model to observe the effect of PBM on ovarian function. Young and aged female ICR mice were treated with or without PBM for 2 months. PBM was performed using a semiconductor InGaAlP laser emitting at 650 nm (80 mW, 6.7 mW/cm2 for 5 or 10 min, resulting in a dose of 2 or 4 J/cm2, respectively). After treatment, the effects of PBM and its role in oxidative stress, inflammation, and mitochondrial function were investigated. We found that PBM (4 J/cm2) effectively recovered the levels of sex hormones, increased the number of primordial and growing follicles, improved angiogenesis, and decreased cell apoptosis in naturally aged mice. Moreover, PBM reduced oxidative stress, inhibited chronic ovarian inflammation, and improved mitochondrial function in aged ovaries. Similar protective effects of PBM were observed in a hydrogen peroxide-induced oxidative stress model of human granulosa cell line (KGN) in vitro. Increased cell viability, cell proliferation, hormone secretion, mitochondrial membrane potential, and adenosine triphosphate levels and decreased apoptosis and oxidative stress were detected in KGN cells after PBM treatment. Collectively, this study suggest that PBM treatment is beneficial for restoring ovarian function in naturally reproductive aging mice and has a significant protective effect against oxidative stress damage in KGN cells. The mechanisms underlying the benefits of PBM in ovarian aging include antioxidant stress, reduction of inflammation, and preservation of mitochondrial function. Therefore, this study emphasizes the potential of PBM as a therapeutic intervention to ameliorate ovarian aging.

Post-senescence reproductive rebound in Daphnia associated with reversal of age-related transcriptional changes

A long-lived species of zooplankton microcrustaceans, Daphnia magna, sometimes exhibits late-life rebound of reproduction, briefly reversing reproductive senescence. Such events are often interpreted as terminal investments in anticipation of imminent mortality. We demonstrate that such post-senescence reproductive events (PSREs) neither cause nor anticipate increased mortality. We analyze an RNAseq experiment comparing young, old reproductively senescent, and old PSRE Daphnia females. We first show that overall age-related transcriptional changes are dominated by the increased transcription of guanidine monophosphate synthases and guanylate cyclases, as well as two groups of presumed transposon-encoded proteins, and by a drop in transcription of protein synthesis-related genes. We then focus on gene families and functional groups in which full or partial reversal of age-related transcriptional changes occur. This analysis reveals a reversal, in the PSRE individuals, of age-related up-regulation of apolipoproteins D, lysosomal lipases, and peptidases as well as several proteins related to mitochondrial and muscle functions. While it is not certain which of these changes enable reproductive rejuvenation, and which are by-products of processes that lead to it, we present some evidence that post-senescence reproductive events are associated with the reversal of age-related protein and lipid aggregates removal and apoptosis.

Immp2l Deficiency Induced Granulosa Cell Senescence Through STAT1/ATF4 Mediated UPRmt and STAT1/(ATF4)/HIF1α/BNIP3 Mediated Mitophagy: Prevented by Enocyanin

Dysfunctional mitochondria producing excessive ROS are the main factors that cause ovarian aging. Immp2l deficiency causes mitochondrial dysfunction and excessive ROS production, leading to ovarian aging, which is attributed to granulosa cell senescence. The pathway controlling mitochondrial proteostasis and mitochondrial homeostasis of the UPRmt and mitophagy are closely related with the ROS and cell senescence. Our results suggest that Immp2l knockout led to granulosa cell senescence, and enocyanin treatment alleviated Immp2l deficiency-induced granulosa cell senescence, which was accompanied by improvements in mitochondrial function and reduced ROS levels. Interestingly, redox-related protein modifications, including S-glutathionylation and S-nitrosylation, were markedly increased in Immp2l-knockout granulosa cells, and were markedly reduced by enocyanin treatment. Furthermore, STAT1 was significantly increased in Immp2l-knockout granulosa cells and reduced by enocyanin treatment. The co-IP results suggest that the expression of STAT1 was controlled by S-glutathionylation and S-nitrosylation, but not phosphorylation. The UPRmt was impaired in Immp2l-deficient granulosa cells, and unfolded and misfolded proteins aggregated in mitochondria. Then, the HIF1α/BNIP3-mediated mitophagy pathway was activated, but mitophagy was impaired due to the reduced fusion of mitophagosomes and lysosomes. The excessive aggregation of mitochondria increased ROS production, leading to senescence. Hence, Enocyanin treatment alleviated granulosa cell senescence through STAT1/ATF4-mediated UPRmt and STAT1/(ATF4)/HIF1α/BNIP3-mediated mitophagy.

From Reactive to Proactive - The Future Life Design to Promote Health and Extend the Human Lifespan

Disease treatment and prevention have improved the human lifespan. Current studies on aging, such as the biological clock and senolytic drugs have focused on the medical treatments of various disorders and health maintenance. However, to efficiently extend the human lifespan to its theoretical maximum, medicine can take a further proactive approach and identify the inapparent disorders that affect the gestation, body growth, and reproductive stages of the so-called "healthy" population. The goal is to upgrade the standard health status to a new level by targeting the inapparent disorders. Thus, future research can shift from reaction, response, and prevention to proactive, quality promotion and vigor prolonging; from single disease-oriented to multiple dimension protocol for a healthy body; from treatment of symptom onset to keep away from disorders; and from the healthy aging management to a healthy promotion design beginning at the birth.

Nicotinamide mononucleotide supplementation rescues mitochondrial and energy metabolism functions and ameliorates inflammatory states in the ovaries of aging mice

Noninvasive pharmacological strategies like nicotinamide mononucleotide (NMN) supplementation can effectively address age-related ovarian infertility by maintaining or enhancing oocyte quality and quantity. This study revealed that ovarian nicotinamide adenine dinucleotide levels decline with age, but NMN administration significantly restores these levels, preventing ovarian atrophy and enhancing the quality and quantity of ovulated oocytes. Improvements in serum hormone secretion and antioxidant factors, along with decreased expression of proinflammatory factors, were observed. Additionally, a significant increase in the number of ovarian follicles in aging individuals was noted. Scanning electron microscopy data indicated that NMN significantly alters the density and morphology of lipid droplets and mitochondria in granulosa cells, suggesting potential targets and mechanisms. Transcriptomic analysis and validation experiments collectively suggested that the beneficial effects of NMN on aging ovaries are mediated through enhanced mitochondrial function, improved energy metabolism, and reduced inflammation levels. Our results suggest that NMN supplementation could improve the health status of aging ovaries and enhance ovarian reserve, offering new insights into addressing fertility challenges in older women through assisted reproductive technology.

Melatonin facilitates oocyte growth in goats and mice through increased nutrient reserves and enhanced mitochondrial function

Oogenesis involves two phases: initial volumetric growth driven by nutrient accumulation and subsequent nuclear maturation. While melatonin (MLT) has been employed as a supplement to enhance the quality of fully grown oocytes during nuclear maturation phase, its impact on oocyte growth remains poorly studied. Here, we provide in vivo evidence demonstrating that follicle-stimulating hormone increases MLT content in ovary. Administration of MLT improves oocyte growth and quality in mice and goats by enhancing nutrient reserves and mitochondrial function. Conversely, MLT-deficient mice have smaller oocytes and dysfunctional mitochondria. Exploring the clinical implications of MLT in promoting oocyte growth, we observe that a brief 2-day MLT treatment enhances oocyte quality and reproductive performance in older mice. These findings highlight the role of MLT in regulating oocyte growth and provide a specific treatment window for optimizing oocyte quality and reproductive performance in female animals.

Premature ovarian insufficiency

Premature ovarian insufficiency (POI) is a cause of infertility and endocrine dysfunction in women, defined by loss of normal, predictable ovarian activity before the age of 40 years. POI is clinically characterized by amenorrhoea (primary or secondary) with raised circulating levels of follicle-stimulating hormone. This condition can occur due to medical interventions such as ovarian surgery or cytotoxic cancer therapy, metabolic and lysosomal storage diseases, infections, chromosomal anomalies and autoimmune diseases. At least 1 in 100 women is affected by POI, including 1 in 1,000 before the age of 30 years. Substantial evidence suggests a genetic basis to POI. However, the cause of idiopathic POI remains unknown in most patients, indicating that gene variants associated with this condition remain to be discovered. Over the past 10 years, tremendous progress has been made in our knowledge of genes involved in POI. Genetic approaches in diagnosis are important as they enable patients with familial POI to be identified, with the opportunity for oocyte preservation. Moreover, genetic approaches could provide a better understanding of disease mechanisms, which will ultimately aid the development of improved treatments.

Rescue intracytoplasmic sperm injection improved cumulative live birth rate for cycles with second polar body extrusion rate <50% in young women: generalized addictive model

OBJECTIVE

To determine the indications for early rescue intracytoplasmic sperm injection (ICSI) application.

DESIGN

A retrospective cohort study.

SETTING

A center for reproductive medicine.

PATIENT(S)

The study included 19,808 patients who underwent conventional in vitro fertilization (IVF) or rescue ICSI for their first cycles between February 2017 and December 2021.

INTERVENTION(S)

Rescue ICSI cycles constituted the study group, where oocytes that had not extruded the second polar body 4-6 hours after insemination were rescued by ICSI. The control group consisted of conventional IVF cycles with no interventions to rescue oocytes without the second polar body. Generalized additive models were constructed to describe the relationship between the second polar body extrusion rate and cumulative live birth rate in conventional IVF and rescue ICSI cycles, respectively. The cutoff value of the second polar body extrusion rate guiding rescue ICSI application was determined from the intersection point of generalized additive models. Maternal age range applicable to rescue ICSI was further analyzed using the same method. Clinical outcomes were compared between conventional IVF and rescue ICSI cycles across different second polar body extrusion rate and maternal age subgroups.

MAIN OUTCOME MEASURE(S)

The second polar body extrusion rate and maternal age range for rescue ICSI application, normal fertilization rate, and cumulative live birth rate.

RESULT(S)

Generalized additive models showed that the cutoff value for the second polar body extrusion rate about rescue ICSI application was 50%. When the rate <50%, normal fertilization rate and cumulative live birth rate (63.7% vs. 46.1%; odds ratio, 1.609; 95% confidence interval, 1.276-2.030) were significantly higher in rescue ICSI cycles than conventional IVF cycles. When the rate ≥50%, rescue ICSI cycles had similar normal fertilization rate and cumulative live birth rate compared with conventional IVF cycles. Further analysis on maternal age in cycles with second polar body extrusion rate <50% released that rescue ICSI cycles showed a higher cumulative live birth rate (67.7% vs. 48.3%; odds ratio, 1.732; 95% confidence interval, 1.361-2.202) than conventional IVF cycles for women aged <38 years.

CONCLUSION(S)

In vitro fertilization cycles with second polar body extrusion rate <50% in women aged <38 years was applicable to early rescue ICSI.

Late reproduction is associated with extended female survival but not with familial longevity

RESEARCH QUESTION

Are age at last childbirth and number of children, as facets of female reproductive health, related to individual lifespan or familial longevity?

DESIGN

This observational study included 10,255 female participants from a multigenerational historical cohort, the LINKing System for historical family reconstruction (LINKS), and 1258 female participants from 651 long-lived families in the Leiden Longevity Study (LLS). Age at last childbirth and number of children, as outcomes of reproductive success, were compared with individual and familial longevity using the LINKS dataset. In addition, the genetic predisposition in the form of a polygenic risk score (PRS) for age at menopause was studied in relation to familial longevity using the LLS dataset.

RESULTS

For each year increase in the age of the birth of the last child, a woman's lifespan increased by 0.06 years (22 days; P = 0.002). The yearly risk for having a last child was 9% lower in women who survived to the oldest 10% of their birth cohort (hazard ratio 0.91, 95% CI 0.86-0.95). Women who came from long-living families did not have a higher mean age of last childbirth. There was no significant association between familial longevity and genetic predisposition to age at menopause.

CONCLUSIONS

Female reproductive health associates with a longer lifespan. Familial longevity does not associate to extended reproductive health. Other factors in somatic maintenance that support a longer lifespan are likely to have an impact on reproductive health.

Biallelic FANCA variants detected in sisters with isolated premature ovarian insufficiency

Premature ovarian insufficiency is a common form of female infertility affecting up to 4% of women and characterised by amenorrhea with elevated gonadotropin before the age of 40. Oocytes require controlled DNA breakage and repair for homologous recombination and the maintenance of oocyte integrity. Biallelic disruption of the DNA damage repair gene, Fanconi anemia complementation group A (FANCA), is a common cause of Fanconi anaemia, a syndrome characterised by bone marrow failure, cancer predisposition, physical anomalies and POI. There is ongoing dispute about the role of heterozygous FANCA variants in POI pathogenesis, with insufficient evidence supporting causation. Here, we have identified biallelic FANCA variants in French sisters presenting with POI, including a novel missense variant of uncertain significance and a likely pathogenic deletion that initially evaded detection. Functional studies indicated no discernible effect on DNA damage sensitivity in patient lymphoblasts. These novel FANCA variants add evidence that heterozygous loss of one allele is insufficient to cause DNA damage sensitivity and POI. We propose that intragenic deletions, that are relatively common in FANCA, may be missed without careful analysis, and could explain the presumed causation of heterozygous variants. Accurate variant curation is critical to optimise patient care and outcomes.

SCM-198 ameliorates the quality of postovulatory and maternally aged oocytes by reducing oxidative stress

Oocyte aging is a key constraint on oocyte quality, leading to fertilization failure and abnormal embryonic development. In addition, it is likely to generate unfavorable assisted reproductive technology (ART) outcomes. SCM-198, a synthetic form of leonurine, was found to rescue the rate of oocyte fragmentation caused by postovulatory aging. Therefore, the aim of this study was to conduct a more in-depth investigation of SCM-198 by exploring its relationship with aged oocytes after ovulation or maternal aging and clarifying whether it affects cell quality. The results indicate that, compared to the postovulatory aged group, the 50 µM SCM-198 group significantly improved sperm-egg binding and increased fertilization of aged oocytes, restoring the spindle apparatus/chromosome structure, cortical granule distribution, and ovastacin and Juno protein distribution. The 50 µM SCM-198 group showed significantly normal mitochondrial distribution, low levels of reactive oxygen species (ROS), and a small quantity of early oocyte apoptosis compared to the postovulatory aged group. Above all, in vivo supplementation with SCM-198 effectively eliminated excess ROS and reduced the spindle/chromosome structural defects in aged mouse oocytes. In summary, these findings indicate that SCM-198 inhibits excessive oxidative stress in oocytes and alters oocyte quality both in vitro and in vivo.

Toxicity mechanism of acrolein on energy metabolism disorder and apoptosis in human ovarian granulosa cells

Acrolein (ACR), an unsaturated, highly reactive aldehyde, is a widespread environmental toxin. ACR exerts permanent and irreversible side effects on ovarian functions. Granulosa cells play a crucial role in supporting ovarian function. Thus, in this study, we investigated the toxicity effects of granulosa cells induced by ACR. Following treatment with varying ACR concentrations (0, 12.5, 25, 50, and 100 μM), we observed that ACR exposure induced reactive oxygen species accumulation, mitochondrial energy metabolism disorder, and apoptosis in KGN cells (a human ovarian granulosa cell line) in a dose-dependent manner. In addition, mitochondrial biogenesis in KGN cells displayed biphasic changes after ACR exposure, with activation at a low ACR dose (12.5 μM), but inhibition at higher ACR doses (≥50 μM). SIRT1/PGC-1α-mediated mitochondrial biogenesis is crucial for maintaining intracellular mitochondrial homeostasis and cellular function. The inhibition/activation of the SIRT1/PGC-1α pathway in KGN cells validated its role in ACR-induced damage. The results indicated that the inhibition of the SIRT1/PGC-1α pathway aggravated ACR-induced cell damage, whereas its activation partially counteracted ACR-induced cell damage. This study attempted to uncover a novel mechanism of ACR-induced ovarian toxicity so as to provide an effective treatment option for safeguarding female reproductive health from the adverse effects of ACR.

Enhancing Oocyte Quality in Aging Mice: Insights from Mesenchymal Stem Cell Therapy and FOXO3a Signaling Pathway Activation

Ovarian aging reduced the quality of oocytes, resulting in age-related female infertility. It is reported that mesenchymal stem cells (MSCs) therapy can improve age-related ovarian function decline and the success rate of in vitro maturation (IVM) in assisted reproductive therapy. In order to investigate the effectiveness and mechanisms of MSCs to enhance oocyte quality of cumulus oocyte complexes (COCs) in advanced age, this study focus on the respective functional improvement of oocytes and granulosa cells (GCs) from aging mice and further to explore and verify the possible mechanisms. Here, we studied a popular but significant protein of follicular development, Forkhead box O-3a (FOXO3a), which is a transcription factor that mediates a variety of cellular processes, but the functions of which in regulating oocyte quality in MSCs therapy still remain inconclusive. In this study, the RNA-seq data of metaphase II (MII) oocytes and GCs isolated from COCs confirmed that, GCs of immature follicles show the most potential to be the targeted cells of bone marrow mesenchymal stem cells (BMSCs) by FOXO3a signaling pathway. Furthermore, we demonstrated the effectiveness of BMSCs co-culture with aging COCs to enhance oocyte quality and found its mechanism to function via ameliorating the biological function of GCs by alleviating FOXO3a levels. These results provide significant fundamental research on MSCs therapy on ovarian aging, as well as offering guidance for raising the success rate of assisted reproductive technology such IVM in clinical and non-clinical settings.

Type III adenylyl cyclase is essential for follicular development in female mice and their reproductive lifespan

Premature ovarian failure (POF) is a complex and heterogeneous disease that causes infertility and subfertility. However, the molecular mechanism of POF has not been fully elucidated. Here, we show that the loss of adenylyl cyclase III (Adcy3) in female mice leads to POF and a shortened reproductive lifespan. We found that Adcy3 is abundantly expressed in mouse oocytes. Adcy3 knockout mice exhibited the excessive activation of primordial follicles, progressive follicle loss, follicular atresia, and ultimately POF. Mechanistically, we found that mitochondrial oxidative stress in oocytes significantly increased with age in Adcy3-deficient mice and was accompanied by oocyte apoptosis and defective folliculogenesis. In contrast, compared with wild-type female mice, humanized ADCY3 knock-in female mice exhibited improved fertility with age. Collectively, these results reveal that the previously unrecognized Adcy3 signaling pathway is tightly linked to female ovarian aging, providing potential pharmaceutical targets for preventing and treating POF.

YAP1 inhibits the senescence of alveolar epithelial cells by targeting Prdx3 to alleviate pulmonary fibrosis

The senescence of alveolar type II (AT2) cells impedes self-repair of the lung epithelium and contributes to lung injury in the setting of idiopathic pulmonary fibrosis (IPF). Yes-associated protein 1 (YAP1) is essential for cell growth and organ development; however, the role of YAP1 in AT2 cells during pulmonary fibrosis is still unclear. YAP1 expression was found to be downregulated in the AT2 cells of PF patients. Deletion of YAP1 in AT2 cells resulted in lung injury, exacerbated extracellular matrix (ECM) deposition, and worsened lung function. In contrast, overexpression of YAP1 in AT2 cells promoted alveolar regeneration, mitigated pulmonary fibrosis, and improved lung function. In addition, overexpression of YAP1 alleviated bleomycin (BLM) -induced senescence of alveolar epithelial cells both in vivo and in vitro. Moreover, YAP1 promoted the expression of peroxiredoxin 3 (Prdx3) by directly interacting with TEAD1. Forced expression of Prdx3 inhibited senescence and improved mitochondrial dysfunction in BLM-treated MLE-12 cells, whereas depletion of Prdx3 partially abrogated the protective effect of YAP1. Furthermore, overexpression of Prdx3 facilitated self-repair of the injured lung and reduced ECM deposition, while silencing Prdx3 attenuated the antifibrotic effect of YAP1. In conclusion, this study demonstrated that YAP1 alleviates lung injury and pulmonary fibrosis by regulating Prdx3 expression to improve mitochondrial dysfunction and block senescence in AT2 cells, revealing a potential novel therapeutic strategy for pulmonary fibrosis.

Targeting mitochondria for ovarian aging: new insights into mechanisms and therapeutic potential

Ovarian aging is a complex process characterized by a decline in oocyte quantity and quality, directly impacting fertility and overall well-being. Recent researches have identified mitochondria as pivotal players in the aging of ovaries, influencing various hallmarks and pathways governing this intricate process. In this review, we discuss the multifaceted role of mitochondria in determining ovarian fate, and outline the pivotal mechanisms through which mitochondria contribute to ovarian aging. Specifically, we emphasize the potential of targeting mitochondrial dysfunction through innovative therapeutic approaches, including antioxidants, metabolic improvement, biogenesis promotion, mitophagy enhancement, mitochondrial transfer, and traditional Chinese medicine. These strategies hold promise as effective means to mitigate age-related fertility decline and preserve ovarian health. Drawing insights from advanced researches in the field, this review provides a deeper understanding of the intricate interplay between mitochondrial function and ovarian aging, offering valuable perspectives for the development of novel therapeutic interventions aimed at preserving fertility and enhancing overall reproductive health.

Bisphenol A and its structural analogues exhibit differential potential to induce mitochondrial dysfunction and apoptosis in human granulosa cells

Bisphenol A (BPA) is an endocrine disruptor strongly associated with ovarian dysfunction. BPA is being substituted by structurally similar chemicals, such as bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF). However, the toxicity of these analogues in female reproduction remains largely unknown. This study evaluated the effects of BPA and its analogues BPS, BPF, and BPAF on the mitochondrial mass and function, oxidative stress, and their potential to induce apoptosis of human granulosa cells (KGN cells). BPA and its analogues, especially BPA and BPAF, significantly decreased mitochondrial activity and cell viability. The potential of bisphenols to reduce mitochondrial mass and function differed in the following order: BPAF > BPA > BPF > BPS. Flow cytometry revealed that exposure to bisphenols significantly increased mitochondrial ROS levels and increased mitochondrial Ca2+ levels. Thus, bisphenols exposure causes mitochondrial stress in KGN cells. At the same time, bisphenols exposure significantly induced apoptosis. These results thus emphasize the toxicity of these bisphenols to cells. Our study suggests the action mechanism of BPA and its analogues in damage caused to ovarian granulosa cells. Additionally, these novel analogues may be regrettable substitutes, and the biological effects and potential risks of BPA alternatives must be evaluated.

Gui ShenWan prevent premature ovarian insufficiency by modulating autophagy and angiogenesis via facilitating VDR

ETHNOPHARMACOLOGICAL RELEVANCE

Gui Shen Wan (GSW) stands out as a promising therapeutic approach for addressing Premature Ovarian Insufficiency (POI). With deep roots in traditional medicine, GSW highlights the ethnopharmacological significance of herbal interventions in addressing nuanced aspects of women's health, with a specific emphasis on ovarian functionality. Recognizing the importance of GSW in gynecological contexts resonates with a rich tradition of using botanical formulations to navigate the intricacies of reproductive health. Delving into GSW's potential for treating POI emphasizes the crucial role of ethnopharmacological insights in guiding modern research endeavors.

AIM OF THE STUDY

GSW is extensively utilized in gynecological disorders and has recently emerged as a potential therapeutic approach for POI. The present investigation aimed to assess the efficacy of GSW in treating POI in rats and elucidate its underlying molecular mechanisms.

MATERIALS AND METHODS

The study employed GSW for POI treatment in rats. GSW, prepared as pills, underwent HPLC fingerprinting for quality control. Reagents and drugs, including VCD and dehydroepiandrosterone (DHEA), were sourced from reputable providers. Eighty Sprague-Dawley rats were categorized into groups for POI induction and treatment. Ovarian tissue underwent HE staining, immunohistochemical staining, Western Blot, qRT-PCR, and vaginal secretion testing. ELISA was utilized for target molecule detection. This methodology ensures a robust and reliable experimental framework.

RESULTS

The results highlight a robust collaborative improvement in POI among rats subjected to combined GSW and DHEA treatment. Particularly noteworthy is the substantial enhancement in the expression of vascular regeneration-related molecules-VDR-Klotho-VEGFR-accompanied by a significant elevation in autophagy levels. Post-GSW administration, rat ovarian morphology demonstrated increased stability, hormone levels exhibited more consistent maintenance, and there was a marked reduction in inflammatory response compared to other groups (p < 0.01). Furthermore, GSW intervention resulted in a more pronounced upregulation of ovarian autophagy (p < 0.05).

CONCLUSION

By modulating VDR-Klotho signaling, GSW exerts regulatory control over ovarian autophagy and vascular regeneration, thereby mitigating the occurrence and progression of POI in rats.

Intravascular Laser Blood Irradiation (ILIB) Enhances Antioxidant Activity and Energy Metabolism in Aging Ovaries

BACKGROUND

Ovarian aging is characterized by the accumulation of free radicals, leading to tissue damage and affecting reproductive health. Intravascular laser irradiation of blood (ILIB, using a low-energy He-Ne laser) is known for its efficacy in treating vascular-related diseases by reducing free radicals and inflammation. However, its impact on ovarian aging remains unexplored. This study aimed to investigate the effects of ILIB on oxidative stress and energy metabolism in aging ovaries.

METHODS

Genetic analysis was conducted on 75 infertile patients with aging ovaries, divided into ILIB-treated and control (CTRL) groups. Patients underwent two courses of laser treatment, and clinical parameters were evaluated. Cumulus cells were collected for the genetic analysis of oxeiptosis, glycolysis, and the tricarboxylic acid (TCA) cycle.

RESULTS

The analysis of gene expression patterns revealed intriguing findings in ILIB-treated patients compared to the untreated group. Notably, ILIB treatment resulted in significant upregulation of oxeiptosis-related genes AIFM1 and NRF2, suggesting a potential protective effect against oxidative stress-induced cell death. Furthermore, ILIB treatment led to a downregulation of glycolysis-associated gene hexokinase 2 (HK2), indicating a shift away from anaerobic metabolism, along with an increase in PDHA levels, indicative of enhanced mitochondrial function. Consistent with these changes, ILIB-treated patients exhibited elevated expression of the key TCA cycle genes citrate synthase (CS), succinate dehydrogenase complex subunit A (SDHA), and fumarate hydratase (FH), signifying improved energy metabolism.

CONCLUSION

The findings from this study underscore the potential of ILIB as a therapeutic strategy for mitigating ovarian aging. By targeting oxidative stress and enhancing energy metabolism, ILIB holds promise for preserving ovarian function and reproductive health in aging individuals. Further research is warranted to elucidate the underlying mechanisms and optimize the application of ILIB in clinical settings, with the ultimate goal of improving fertility outcomes in women experiencing age-related ovarian decline.

[Research Progress in the Role of Mitochondrial Dysfunction in Endometriosis-Associated Infertility]

Endometriosis (EMT), a common benign gynecological disease, is a leading cause of infertility in women. EMT affects female fertility in various aspects. However, the underlying mechanisms have not been fully elucidated. Mitochondria are known as the "powerhouse" of a cell. They play pivotal roles in the physiological processes of cellular energy metabolism, calcium homeostasis, oxidative stress, autophagy, the regulation of cell cycle, and cell death, and are involved in the pathophysiology of many diseases. Cellular mitochondria are highly dynamic, continuously undergoing cyclic fission and fusion to meet the demands of cellular activities. Balanced mitochondrial dynamics are critical for maintaining normal reproductive function in women. In addition, mitochondria are the major source of reactive oxygen species (ROS). Cell damage, cell death, and fibrosis mediated by the imbalance in the oxidative-antioxidant system in EMT patients lead to decreased oocyte quality and ovarian reserve. Currently, the treatment of EMT-associated infertility remains a challenging and controversial topic. We herein reviewed the latest findings on the role of mitochondrial dysfunction in EMT-associated infertility and the potential therapeutic targets.

P62 promotes FSH-induced antral follicle formation by directing degradation of ubiquitinated WT1

In females, the pathophysiological mechanism of poor ovarian response (POR) is not fully understood. Considering the expression level of p62 was significantly reduced in the granulosa cells (GCs) of POR patients, this study focused on identifying the role of the selective autophagy receptor p62 in conducting the effect of follicle-stimulating hormone (FSH) on antral follicles (AFs) formation in female mice. The results showed that p62 in GCs was FSH responsive and that its level increased to a peak and then decreased time-dependently either in ovaries or in GCs after gonadotropin induction in vivo. GC-specific deletion of p62 resulted in subfertility, a significantly reduced number of AFs and irregular estrous cycles, which were same as pathophysiological symptom of POR. By conducting mass spectrum analysis, we found the ubiquitination of proteins was decreased, and autophagic flux was blocked in GCs. Specifically, the level of nonubiquitinated Wilms tumor 1 homolog (WT1), a transcription factor and negative controller of GC differentiation, increased steadily. Co-IP results showed that p62 deletion increased the level of ubiquitin-specific peptidase 5 (USP5), which blocked the ubiquitination of WT1. Furthermore, a joint analysis of RNA-seq and the spatial transcriptome sequencing data showed the expression of steroid metabolic genes and FSH receptors pivotal for GCs differentiation decreased unanimously. Accordingly, the accumulation of WT1 in GCs deficient of p62 decreased steroid hormone levels and reduced FSH responsiveness, while the availability of p62 in GCs simultaneously ensured the degradation of WT1 through the ubiquitin‒proteasome system and autophagolysosomal system. Therefore, p62 in GCs participates in GC differentiation and AF formation in FSH induction by dynamically controlling the degradation of WT1. The findings of the study contributes to further study the pathology of POR.

[Mechanisms of the Effect of Maternal Age-Related Oocyte Aging on Fertility: Transcriptomic Sequencing Analysis of a Zebrafish Model]

Objective

Female fertility gradually decreases with the increase in women's age. The underlying reasons include the decline in the quantity and quality of oocytes. Oocyte aging is an important manifestation of the decline in oocyte quality, including in vivo oocyte aging before ovulation and in vitro oocyte aging after ovulation. Currently, few studies have been done to examine oocyte aging, and the relevant molecular mechanisms are not fully understood. Therefore, we used zebrafish as a model to investigate oocyte aging. Three different age ranges of female zebrafish were selected to mate with male zebrafish of the best breeding age. In this way, we studied the effects of maternal age-related oocyte aging on fertility and investigated the potential molecular mechanisms behind maternal age-related fertility decline.

Methods

Eight female zebrafish aged between 158 and 195 d were randomly selected for the 6-month age group (180±12) d, 8 female zebrafish aged between 330 and 395 d were randomly selected for the 12-month age group (360±22) d, and 8 female zebrafish aged between 502 and 583 d were randomly selected for the 18-month age group (540±26) d. Male zebrafish of (180±29) d were randomly selected from zebrafish aged between 158 and 195 d and mated with female zebrafish in each group. Each mating experiment included 1 female zebrafish and 1 male zebrafish. Zebrafish embryos produced by the mating experiments were collected and counted. The embryos at 4 hours post-fertilization were observed under the microscope, the total number of embryos and the number of unfertilized embryos were counted, and the fertilization rate was calculated accordingly. The numbers of malformed embryos and dead embryos were counted 24 hours after fertilization, and the rates of embryo malformation and mortality were calculated accordingly. The primary outcome measure was the embryo fertilization rate, and the secondary outcome measures were the number of embryos per spawn (the total number of embryos laid within 1.5 hours after the beginning of mating and reproduction of the zebrafish), embryo mortality, and embryo malformation rate. The outcome measures of each group were compared. The blastocyst embryos of female zebrafish from each group born after mating with male zebrafish in their best breeding period were collected for transcriptomics analysis. Fresh oocytes of female zebrafish in each group were collected for transcriptomics analysis to explore the potential molecular mechanisms of maternal age-related fertility decline.

Results

Compared with that of the 6-month group (94.9%±3.6%), the embryo fertilization rate of the 12-month group (92.3%±4.2%) showed no significant difference, but that of the 18-month group (86.8%±5.5%) decreased significantly (P<0.01). In addition, the fertilization rate in the 18-month group was significantly lower than that in the 12-month group (P<0.05). Compared with that of the 6-month group, the embryo mortality of the female zebrafish in the 12-month group and that in the 18-month group were significantly higher than that in the 6-month group (P<0.000 1, P<0.001). There was no significant difference in the number of embryos per spawn or in the embryo malformation rate among the three groups. The results of the transcriptomics analysis of blastocyst embryos showed that some genes, including dusp5, bdnf, ppip5k2, dgkg, aldh3a2a, acsl1a, hal, mao, etc, were differentially expressed in the 12-month group or the 18-month group compared with their expression levels in the 6-month group. According to the KEGG enrichment analysis, these differentially expressed genes (DEGs) were significantly enriched in the MAPK signaling pathway, the phosphatidylinositol signaling system, and the fatty acid degradation and histidine metabolism pathway (P<0.05). The analysis of the expression trends of the genes expressed differentially among the three groups (the 6-month group, the 12-month group, and the 18-month group in turn) showed that the gene expression trends of fancc, fancg, fancb, and telo2, which were involved in Fanconi anemia pathway, were statistically significant (P<0.05). In the results of oocyte transcriptomics analysis, the genes that were differentially expressed in the 12-month group or the 18-month group compared with the 6-month group were mainly enriched in cell adhesion molecules and the protein digestion and absorption pathway (P<0.05). The results of the trends of gene expression in the zebrafish oocytes of the three groups (the 6-month group, the 12-month group, and the 18-month group in turn) showed that three kinds of gene expression trends of declining fertility with growing maternal age had significant differences (P<0.05). Further analysis of the three significantly differential expression trends showed 51 DEGs related to mitochondria and 5 DEGs related to telomere maintenance and DNA repair, including tomm40, mpc2, nbn, tti1, etc.

Conclusion

With the increase in the maternal age of the zebrafish, the embryo fertilization rate decreased significantly and the embryo mortality increased significantly. In addition, with the increase in the maternal age of the zebrafish, the expression of mitochondria and telomere-related genes, such as tomm40, mpc2, nbn, and tti1, in female zebrafish oocytes decreased gradually. Maternal age may be a factor contributing to the decrease in oocyte fertilization ability and the increase in early embryo mortality. Maternal age-related oocyte aging affects the fertility and embryo development of the offspring.

Nicotinamide Mononucleotide and Nicotinamide Riboside Reverse Ovarian Aging in Rats Via Rebalancing Mitochondrial Fission and Fusion Mechanisms

PURPOSE

This study examined the effects of nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR) on folliculogenesis and mitochondrial dynamics (fission and fusion mechanisms) in ovaries of middle-aged female rats.

METHODS

Experimental groups were young, middle-aged (control), middle-aged + NMN and middle-aged + NR. NMN was administered at a concentration of 500 mg/kg intraperitoneally but NR at a concentration of 200 mg/kg by gavage. Follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels were analyzed by ELISA. Hematoxylin-eosin staining sections were used for histopathological examination and follicles-counting. Expression levels of mitochondrial fission (Drp1, Mff and Fis1) and fusion (Mfn1, Mfn2, Opa1, Fam73a and Fam73b) genes as well as Sirt1 gene were analyzed by RT-PCR. Expression levels of fission-related proteins (DRP1, MFF, FIS1 and SIRT1) were analyzed by Western Blot.

RESULTS

Higher ovarian index, more corpus luteum and antral follicles were detected in NMN and NR groups compared to the control. NMN or NR could rebalance LH/FSH ratio. The control group was determined to possess higher expression levels of fission genes and lower expression levels of fusion genes when compared the young group. In comparison with the control group, both NMN and NR group were found to exhibit less mitochondrial fission but more mitochondrial fussion. Higher gene and protein levels for Sirt1 were measured in NMN and NR groups compared to the control group.

CONCLUSION

This study reveals that NMN alone or NR alone can rebalance mitochondrial dynamics by decreasing excessive fission in middle-aged rat ovaries, thus alleviating mitochondrial stress and correcting aging-induced folliculogenesis abnormalities.

Combination of bone marrow mesenchymal stem cells and moxibustion restores cyclophosphamide-induced premature ovarian insufficiency by improving mitochondrial function and regulating mitophagy

BACKGROUND

Premature ovarian insufficiency (POI) is a major cause of infertility. In this study, we aimed to investigate the effects of the combination of bone marrow mesenchymal stem cells (BMSCs) and moxibustion (BMSCs-MOX) on POI and evaluate the underlying mechanisms.

METHODS

A POI rat model was established by injecting different doses of cyclophosphamide (Cy). The modeling of POI and the effects of the treatments were assessed by evaluating estrous cycle, serum hormone levels, ovarian weight, ovarian index, and ovarian histopathological analysis. The effects of moxibustion on BMSCs migration were evaluated by tracking DiR-labeled BMSCs and analyzing the expression of chemokines stromal cell-derived factor 1 (Sdf1) and chemokine receptor type 4 (Cxcr4). Mitochondrial function and mitophagy were assessed by measuring the levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), ATP, and the mitophagy markers (Drp1, Pink1, and Parkin). Furthermore, the mitophagy inhibitor Mdivi-1 and the mitophagy activator CCCP were used to confirm the role of mitophagy in Cy-induced ovarian injury and the underlying mechanism of combination therapy.

RESULTS

A suitable rat model of POI was established using Cy injection. Compared to moxibustion or BMSCs transplantation alone, BMSCs-MOX showed improved outcomes, such as reduced estrous cycle disorders, improved ovarian weight and index, normalized serum hormone levels, increased ovarian reserve, and reduced follicle atresia. Moxibustion enhanced Sdf1 and Cxcr4 expression, promoting BMSCs migration. BMSCs-MOX reduced ROS levels; upregulated MMP and ATP levels in ovarian granulosa cells (GCs); and downregulated Drp1, Pink1, and Parkin expression in ovarian tissues. Mdivi-1 significantly mitigated mitochondrial dysfunction in ovarian GCs and improved ovarian function. CCCP inhibited the ability of BMSCs-MOX treatment to regulate mitophagy and ameliorate Cy-induced ovarian injury.

CONCLUSIONS

Moxibustion enhanced the migration and homing of BMSCs following transplantation and improves their ability to repair ovarian damage. The combination of BMSCs and moxibustion effectively reduced the excessive activation of mitophagy, which helped prevent mitochondrial damage, ultimately improving ovarian function. These findings provide a novel approach for the treatment of pathological ovarian aging and offer new insights into enhancing the efficacy of stem cell therapy for POI patients.

Perilipin 5 regulates hepatic stellate cell activation and high-fat diet-induced non-alcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases globally. Hepatic stellate cells (HSCs) are the major effector cells of liver fibrosis. HSCs contain abundant lipid droplets (LDs) in their cytoplasm during quiescence. Perilipin 5 (PLIN 5) is a LD surface-associated protein that plays a crucial role in lipid homeostasis. However, little is known about the role of PLIN 5 in HSC activation.

METHODS

PLIN 5 was overexpressed in HSCs of Sprague-Dawley rats by lentivirus transfection. At the same time, PLIN 5 gene knockout mice were constructed and fed with a high-fat diet (HFD) for 20 weeks to study the role of PLIN 5 in NAFLD. The corresponding reagent kits were used to measure TG, GSH, Caspase 3 activity, ATP level, and mitochondrial DNA copy number. Metabolomic analysis of mice liver tissue metabolism was performed based on UPLC-MS/MS. AMPK, mitochondrial function, cell proliferation, and apoptosis-related genes and proteins were detected by western blotting and qPCR.

RESULTS

Overexpression of PLIN 5 in activated HSCs led to a decrease in ATP levels in mitochondria, inhibition of cell proliferation, and a significant increase in cell apoptosis through AMPK activation. In addition, compared with the HFD-fed C57BL/6J mice, PLIN 5 knockout mice fed with HFD showed reduced liver fat deposition, decreased LD abundance and size, and reduced liver fibrosis.

CONCLUSION

These findings highlight the unique regulatory role of PLIN 5 in HSCs and the role of PLIN 5 in the fibrosis process of NAFLD.

Treatment With a Patented 3.6:1 Myo-Inositol to D-chiro-Inositol Ratio, Antioxidants, Vitamins and Minerals Food Supplement in Women With a History of Assisted Reproductive Technique (ART) Failures: A Series of Case Reports

Infertility affects 15% of couples in reproductive age worldwide. In women in particular, infertility can be caused by various abnormalities, with polycystic ovary syndrome (PCOS) being the most common. Currently, there are many assisted reproductive techniques (ART) available to combat the burden of infertility. However, positive results are not guaranteed. The administration of inositol has been shown to increase positive reproductive outcomes in women undergoing ART. Here we present a series of clinical cases in which women with a history of infertility and previously failed ART, supplemented with a specific 3.6:1 MYO:DCI ratio, antioxidants, vitamins, and minerals for a period of 1 to 3 months before undergoing in vitro fertilization (IVF). In this series of case reports, we provide preliminary evidence that supplementation with a specific 3.6:1 MYO to DCI ratio, as well as antioxidants, vitamins, and minerals may contribute positively to female fertility in women undergoing IVF, with a history of primary or secondary infertility and previously failed ART.

Minerals and the Menstrual Cycle: Impacts on Ovulation and Endometrial Health

The role of minerals in female fertility, particularly in relation to the menstrual cycle, presents a complex area of study that underscores the interplay between nutrition and reproductive health. This narrative review aims to elucidate the impacts of minerals on key aspects of the reproductive system: hormonal regulation, ovarian function and ovulation, endometrial health, and oxidative stress. Despite the attention given to specific micronutrients in relation to reproductive disorders, there is a noticeable absence of a comprehensive review focusing on the impact of minerals throughout the menstrual cycle on female fertility. This narrative review aims to address this gap by examining the influence of minerals on reproductive health. Each mineral's contribution is explored in detail to provide a clearer picture of its importance in supporting female fertility. This comprehensive analysis not only enhances our knowledge of reproductive health but also offers clinicians valuable insights into potential therapeutic strategies and the recommended intake of minerals to promote female reproductive well-being, considering the menstrual cycle. This review stands as the first to offer such a detailed examination of minerals in the context of the menstrual cycle, aiming to elevate the understanding of their critical role in female fertility and reproductive health.

Nobiletin Ameliorates Aging of Chicken Ovarian Prehierarchical Follicles by Suppressing Oxidative Stress and Promoting Autophagy

With the increase in the age of laying chickens, the aging of follicles is accelerated, and the reproductive ability is decreased. Increased oxidative stress and mitochondrial malfunction are indispensable causes of ovarian aging. In this study, the physiological condition of prehierarchical small white follicles (SWFs) was compared between D280 high-producing chickens and D580 aging chickens, and the effect of a plant-derived flavonoid nobiletin (Nob), a natural antioxidant, on senescence of SWFs granulosa cells (SWF-GCs) was investigated. The results showed that Nob treatment activated cell autophagy by activating the AMP-activated protein kinase (AMPK) and Sirtuin-1 (SIRT1) pathways in D-galactose (D-gal)-generated senescent SWF-GCs, restoring the expression of proliferation-related mRNAs and proteins. In addition, the expression of inflammation-related protein NF-κB was significantly enhanced in aging GCs that were induced by D-gal. Nob supplementation significantly increased the antioxidant capacity and decreased the expression of several genes associated with cell apoptosis. Furthermore, Nob promoted activation of PINK1 and Parkin pathways for mitophagy and alleviated mitochondrial edema. Either the AMPK inhibitor dorsomorphin (Compound C) or SIRT1 inhibitor selisistat (EX-527) attenuated the effect of Nob on mitophagy. The protective effect of Nob on natural aging, GC proliferation, and elimination of the beneficial impact on energy regulation of naturally aging ovaries was diminished by inhibition of Nob-mediated autophagy. These data suggest that Nob treatment increases the expression of mitophagy-related proteins (PINK1 and Parkin) via the AMPK/SIRT1 pathways to prevent ovarian aging in the laying chickens.

Mitochondrial Unfolded Protein Response Gene Clpp Is Required for Oocyte Function and Female Fertility

Mitochondrial unfolded protein stress response (mtUPR) plays a critical role in regulating cellular and metabolic stress response and helps maintain protein homeostasis. Caseinolytic peptidase P (CLPP) is one of the key regulators of mtUPR and promotes unfolded protein degradation. Previous studies demonstrated that global deletion of Clpp resulted in female infertility, whereas no impairment was found in the mouse model with targeted deletion of Clpp in cumulus/granulosa cells. These results suggest the need to delineate the function of Clpp in oocytes. In this study, we aimed to further explore the role of mtUPR in female reproductive competence and senescence using a mouse model. Oocyte-specific targeted deletion of Clpp in mice resulted in female subfertility associated with metabolic and functional abnormalities in oocytes, thus highlighting the importance of CLPP-mediated protein homeostasis in oocyte competence and reproductive function.

Mitochondrial abnormality in ovarian granulosa cells of patients with polycystic ovary syndrome

The quality of oocytes in patients with polycystic ovary syndrome (PCOS) decreases, which is closely related to the function of oocytes' mitochondria. If mitochondrial dysfunction is involved in PCOS, it is likely to affect the function of cumulus cells. However, the mechanism of mitochondrial dysfunction remains unclear. In the present study, granulosa cells were collected from women attending the Hebei Reproductive Health Hospital and were divided into the normal ovarian reserve group (CON group) and the PCOS group. The mitochondrial ultrastructure was observed by transmission electron microscope, and the mitochondrial function was determined by detecting the ATP content, reactive oxygen species levels, the number of mitochondria and the mitochondrial membrane potential. Additionally, western blotting was used to compare the expression levels of mitochondrial kinetic protein, the related channel protein, between the two groups. In the present study, it was found that patients with PCOS had abnormal granulosa cell morphology, increased mitochondrial abnormalities, decreased mitochondrial function and disturbed mitochondrial dynamics. In addition, the silent information regulator 1/phosphorylated‑AMP‑activated protein kinase/peroxisome proliferator‑activated receptor‑γ coactivator 1α pathway expression was decreased, and it was hypothesized that the decreased mitochondrial mass in the PCOS group was associated with it.

Antimullerian Hormone, a Marker of Ovarian Reserve, Is Protective Against Presence and Severity of NASH in Premenopausal Women

BACKGROUND & AIMS

Antimüllerian hormone (AMH) is a marker of ovarian reserve with emerging data linking lower levels to some metabolic and inflammatory diseases in women. Whether AMH levels influence nonalcoholic fatty liver disease (NAFLD) is unknown.

METHODS

Leveraging the NASH Clinical Research Network we determined the association of AMH levels within 6 months of liver biopsy with presence and severity of histologic measures of NAFLD in premenopausal women. Outcomes included presence of nonalcoholic steatohepatitis (NASH), presence and severity of fibrosis, and NAFLD Activity Score and its components. Logistic and ordinal logistic regression models were adjusted for age, race/ethnicity, homeostatic model assessment for insulin resistance, body mass index, dyslipidemia, polycystic ovary syndrome, estrogen-progestin use, and menstrual cyclicity.

RESULTS

Median cohort age was 35 years; 73% were white and 24% Hispanic. Thirty-three percent had diabetes, 81% had obesity, and 95% had dyslipidemia. On biopsy 71% had NASH, 68% had any fibrosis, and 15% had advanced fibrosis. On adjusted analysis (n = 205), higher AMH quartiles were inversely associated with NAFLD histology including prevalent NASH (adjusted odds ratio [AOR], 0.64; 95% confidence interval [CI], 0.41-1.00), NAFLD Activity Score ≥5 (AOR, 0.52; 95% CI, 0.35-0.77), Mallory hyaline (AOR, 0.54; 95% CI, 0.35-0.82), and higher fibrosis stage (AOR, 0.70; 95% CI, 0.51-0.98). The protective effects of AMH were more pronounced among women without polycystic ovary syndrome (n = 164), including lower odds of NASH (AOR, 0.53; 95% CI, 0.32-0.90) and any NASH fibrosis (AOR, 0.54; 95% CI, 0.32-0.93).

CONCLUSIONS

AMH may reflect a unique biomarker of NASH in premenopausal women and findings suggest a novel link between reproductive aging and histologic severity of NAFLD in women.

Promising anti-ovarian aging herbal formulation He's Yangchao promotes in vitro maturation of oocytes from advanced maternal age mice

ETHNOPHARMACOLOGICAL RELEVANCE

Marveled at the discovery of artemisinin, the world's expectations for traditional Chinese medicine are rising. He's Yangchao formula (HSYC) is a traditional Chinese herbal formula with the effects of tonifying kidney and essence, and reconciling yin and yang. It has been clinically proven to have anti-ovarian aging effects. Age is the primary cause of diminished ovarian reserve and assisted reproductive failure in women, whether HSYC has the potential to improve in vitro maturation of oocytes from advanced maternal age (AMA) mice has yet to be determined.

AIM OF THE STUDY

This study aims to evaluate the efficacy and possible mechanism of HSYC in promoting in vitro maturation of oocytes from AMA mice.

MATERIALS AND METHODS

The GV oocytes were obtained from young and aged mice. The GV oocytes from young mice were cultured in drops of M16 medium, and the GV oocytes from AMA mice were randomly divided four groups: Vehicle group (cultured in 90% M16 medium +10% blank serum), Low HSYC group (cultured in 90% M16 medium + 10% Low HSYC-medicated serum), High-HSYC group (cultured in 90% M16 medium +10% High HSYC-medicated serum), and Quercetin group (cultured in M16 medium supplemented with 10 μM quercetin). The rates of first polar body extrusion, reactive oxygen species (ROS), intracellular calcium, and mitochondrial membrane potential levels in each groups were observed. In addition, expression levels of mitochondrial function, autophagy, DNA damage, and antioxidant-related proteins were assessed.

RESULTS

Supplementation of HSYC in vitro alleviated age-associated meiotic progression defects in maternally aged oocytes. Importantly, HSYC supplementation eliminated the age-related ROS accumulation to suppress DNA damage and autophagy during the in vitro maturation of maternally aged oocytes. Meanwhile, the mitochondrial function was improved after HSYC treatment, as manifested by higher mitochondrial membrane potential and lower Ca2+ levels. Furthermore, we found that HSYC supplementation during in vitro maturation of maternally aged oocytes upregulated the expression level of SIRT3, a crucial protein in regulating mitochondrial function. Consistently, the expression levels of the SOD2, PCG1α, and TFAM were increased, while the SOD2 acetylation level was decreased, which further proved its antioxidant function.

CONCLUSIONS

HSYC supplementation promotes in vitro maturation of oocytes from AMA mice mainly via improving mitochondrial function and alleviating oxidative stress. The mechanism may be related to the regulation of SIRT3-dependent deacetylation of the SOD2 pathway.

ErZhiTianGui Decoction alleviates age-related ovarian aging by regulating mitochondrial homeostasis and inhibiting ferroptosis

AIM

This study was designed to investigate the pharmacological effects and mechanisms of ErZhiTianGui Decoction (EZTG) for age-related ovarian aging in mice.

METHODS

This study used naturally aging mice as a model, and EZTG was used for intragastric administration. Ovarian pathological changes, as well as follicular reserve were assessed by hematoxylin and eosin staining, and serum hormone levels (anti-mullerian hormone, follicle-stimulating hormone), mitochondrial reactive oxygen species (ROS) and mitochondrial DNA (mtDNA) damage marker 8-hydroxy-2'-deoxyguanosine(8-OHdG), and lipid peroxidation markers glutathione(GSH) and malondialdehyde(MDA) were determined by enzyme-linked immunosorbent assay. Mitochondrial membrane potential (MMP) levels in ovaries were determined using flow cytometry. The levels of PINK1 and Parkin were observed using immunofluorescence staining. Mitochondrial-derived vesicles (MDVs) and mitochondrial morphology were observed using electron microscopy. Prussian blue staining was used to observe iron ion aggregation in ovarian tissue. The Iron assay kits detected total iron levels. Western blot was used to detect the expression of proteins related to mitochondrial and ferroptosis related genes.

RESULTS

After EZTG treatment, aged mice showed increased ovarian reserve, improved serum hormone levels, increased MMP, GSH levels, and decreased mitochondrial ROS, 8-OHdG, and MDA levels. Immunofluorescence staining showed decreased levels of PINK1 and Parkin, and the same trend was observed for the Western blot. Meanwhile, electron microscopy showed that EZTG improved the mitochondrial morphology in the ovaries of aged mice. EZTG also decreased the total iron and protein levels of Acyl-CoA synthetase long-chain family4 (ACSL4) and increased the protein level of glutathione peroxidase 4 (GPX4) in the ovaries of aged mice.

CONCLUSIONS

EZTG can maintain PINK1/Parkin-mediated mitochondrial homeostasis, reduce the lipid peroxidation caused by the accumulation of ROS, and inhibit the occurrence of ferroptosis and delaying ovarian aging. These findings suggest that EZTG may be a promising drug for treating age-related ovarian aging in females.

Mitochondrial-related microRNAs and their roles in cellular senescence

Aging is a natural aspect of mammalian life. Although cellular mortality is inevitable, various diseases can hasten the aging process, resulting in abnormal or premature senescence. As cells age, they experience distinctive morphological and biochemical shifts, compromising their functions. Research has illuminated that cellular senescence coincides with significant alterations in the microRNA (miRNA) expression profile. Notably, a subset of aging-associated miRNAs, originally encoded by nuclear DNA, relocate to mitochondria, manifesting a mitochondria-specific presence. Additionally, mitochondria themselves house miRNAs encoded by mitochondrial DNA (mtDNA). These mitochondria-residing miRNAs, collectively referred to as mitochondrial miRNAs (mitomiRs), have been shown to influence mtDNA transcription and protein synthesis, thereby impacting mitochondrial functionality and cellular behavior. Recent studies suggest that mitomiRs serve as critical sensors for cellular senescence, exerting control over mitochondrial homeostasis and influencing metabolic reprogramming, redox equilibrium, apoptosis, mitophagy, and calcium homeostasis-all processes intimately connected to senescence. This review synthesizes current findings on mitomiRs, their mitochondrial targets, and functions, while also exploring their involvement in cellular aging. Our goal is to shed light on the potential molecular mechanisms by which mitomiRs contribute to the aging process.

Association between migraine and mitochondria: A Mendelian randomization study

BACKGROUND AND OBJECTIVE

Mitochondria are important organelles functioning in metabolic processes, inflammatory response and neurological disorders. Migraines are chronic and paroxysmal neurological disorders characterized by recurrent episodes of severe headache and other neurological symptoms. We explored whether mitochondria may be genetically and/or causally associated with migraine.

METHODS

Summary-level statistics of mitochondrial DNA copy number (mtDNA-CN), 69 mitochondria related exposures and migraine with aura, migraine without aura, migraine with aura and triptan purchases, migraine with aura, drug-induced, migraine without aura and triptan purchases and migraine without aura, drug-induced, were collected from genome-wide association studies (GWAS). The analysis employed two-sample Mendelian randomization, utilizing various methods including MR-Egger, inverse-variance weighted (IVW), MR-PRESSO (MR-pleiotropy residual sum and outlier), maximum likelihood, and weighted median.

RESULTS

We observed a potential association with decreased levels of mtDNA-CN with the risk of migraine without aura (Odds ratio (OR) 1.517, 95% Confidence interval (CI) 1.072-2.147, p = 0.019). Besides, for every 1 unit in NAD-dependent protein deacylase sirtuin-5 (SIRT5), relative risk of migraine without aura increased by 16.4%. For every 1 unit increase in Phenylalanine-transfer RNA (tRNA) ligase, relative risk of migraine without aura increased by 13.5%. For every 1 unit increase in Apoptosis-inducing factor 1, relative risk of migraine without aura increased by 27.4%.

CONCLUSION

This study indicates fresh evidence of association between mtDNA-CN, mitochondrial related exposures and migraine especially migraine without aura. The findings may shed light on developing interventions targeting on the causal pathway from mitochondria to migraine.

The Impact of Mitochondria in Ovarian Cancer Cell Metabolism, Proliferation, and Metastasis

Mitochondrial dysfunctions are significantly implicated in cancer initiation, progression, and metastasis, which have been shown for several cancers including ovarian cancer.An increase in mitochondrial dysfunction is also associated with drug resistance along with cancer progression, which in part is related to its specific microenvironment that is characterized by ascites, low glucose levels, and hypoxia that causes ovarian cancer cells to switch to mitochondrial respiration to enable their survival. Peritoneal ascitic fluid accumulation is a specific feature of ovarian cancer, and it is a major cause of its metastatic spread that also presents challenges for effective treatment. Among the treatment difficulties for ovarian cancer is the mutation rate and frequency of mtDNA in ovarian cancer tissue that can affect the efficiency of chemotherapeutic drugs. The varied and multiple mutations of different types enable metabolic reprogramming, cancer cell proliferation, and drug resistance.New specific information on mechanisms underlying several of the mitochondrial dysfunctions has led to proposing various mitochondrial determinants as targets for ovarian cancer therapy, which include targeting specific mitochondrial proteins and phosphoproteins as well as reactive oxygen species (ROS) that accumulate abnormally in cancer cells. Because of the genetically and histologically heterogeneous nature of the disease, combination therapy approaches will be necessary to combat the disease and achieve progress in effective treatment of ovarian cancer. This chapter will address (1) mitochondrial vulnerabilities underlying dysfunction and disease; (2) mitochondrial dysfunction in ovarian cancer; (3) present treatment difficulties for ovarian cancer and new potential treatment strategies to target ovarian cancer mitochondrial metabolism; and (4) biobehavioral factors influencing ovarian cancer development.

High-fat diet-induced L-saccharopine accumulation inhibits estradiol synthesis and damages oocyte quality by disturbing mitochondrial homeostasis

High-fat diet (HFD) has been linked to female infertility. However, the specific age at which HFD impacts ovarian function and the underlying mechanisms remain poorly understood. Here, we administered a HFD to female mice at various developmental stages: pre-puberty (4 weeks old), post-puberty (6 weeks old), young adult (9 weeks old), and middle age (32 weeks old). Our observations indicated that ovarian function was most significantly compromised when HFD was initiated at post-puberty. Consequently, post-puberty mice were chosen for further investigation. Through transplantation of fecal bacteria from the HFD mice to the mice on a normal diet, we confirmed that gut microbiota dysbiosis contributed to HFD-induced deteriorated fertility and disrupted estradiol synthesis. Utilizing untargeted and targeted metabolomics analyses, we identified L-saccharopine as a key metabolite, which was enriched in the feces, serum, and ovaries of HFD and HFD-FMT mice. Subsequent in vitro and in vivo experiments demonstrated that L-saccharopine disrupted mitochondrial homeostasis by impeding AMPKα/MFF-mediated mitochondrial fission. This disruption ultimately hindered estradiol synthesis and compromised oocyte quality. AICAR, an activator of AMPKα, ameliorated L-saccharopine induced mitochondrial damage in granulosa cells and oocytes, thereby enhancing E2 synthesis and improving oocyte quality. Collectively, our findings indicate that the accumulation of L-saccharopine may play a pivotal role in mediating HFD-induced ovarian dysfunction. This highlights the potential therapeutic benefits of targeting the gut microbiota-metabolite-ovary axis to address HFD-induced ovarian dysfunction.

The stromal microenvironment and ovarian aging: mechanisms and therapeutic opportunities

For decades, most studies of ovarian aging have focused on its functional units, known as follicles, which include oocytes and granulosa cells. However, in the ovarian stroma, there are a variety of somatic components that bridge the gap between general aging and ovarian senescence. Physiologically, general cell types, microvascular structures, extracellular matrix, and intercellular molecules affect folliculogenesis and corpus luteum physiology alongside the ovarian cycle. As a result of damage caused by age-related metabolite accumulation and external insults, the microenvironment of stromal cells is progressively remodeled, thus inevitably perturbing ovarian physiology. With the established platforms for follicle cryopreservation and in vitro maturation and the development of organoid research, it is desirable to develop strategies to improve the microenvironment of the follicle by targeting the perifollicular environment. In this review, we summarize the role of stromal components in ovarian aging, describing their age-related alterations and associated effects. Moreover, we list some potential techniques that may mitigate ovarian aging based on their effect on the stromal microenvironment.

Impact of NAD+ metabolism on ovarian aging

Nicotinamide adenine dinucleotide (NAD+), a crucial coenzyme in cellular redox reactions, is closely associated with age-related functional degeneration and metabolic diseases. NAD exerts direct and indirect influences on many crucial cellular functions, including metabolic pathways, DNA repair, chromatin remodeling, cellular senescence, and immune cell functionality. These cellular processes and functions are essential for maintaining tissue and metabolic homeostasis, as well as healthy aging. Causality has been elucidated between a decline in NAD levels and multiple age-related diseases, which has been confirmed by various strategies aimed at increasing NAD levels in the preclinical setting. Ovarian aging is recognized as a natural process characterized by a decline in follicle number and function, resulting in decreased estrogen production and menopause. In this regard, it is necessary to address the many factors involved in this complicated procedure, which could improve fertility in women of advanced maternal age. Concerning the decrease in NAD+ levels as ovarian aging progresses, promising and exciting results are presented for strategies using NAD+ precursors to promote NAD+ biosynthesis, which could substantially improve oocyte quality and alleviate ovarian aging. Hence, to acquire further insights into NAD+ metabolism and biology, this review aims to probe the factors affecting ovarian aging, the characteristics of NAD+ precursors, and the current research status of NAD+ supplementation in ovarian aging. Specifically, by gaining a comprehensive understanding of these aspects, we are optimistic about the prominent progress that will be made in both research and therapy related to ovarian aging.

Autologous non-invasively derived stem cells mitochondria transfer shows therapeutic advantages in human embryo quality rescue

BACKGROUND

The decline in the quantity and quality of mitochondria are closely associated with infertility, particularly in advanced maternal age. Transferring autologous mitochondria into the oocytes of infertile females represents an innovative and viable strategy for treating infertility, with no concerns regarding ethical considerations. As the donor cells of mitochondria, stem cells have biological advantages but research and evidence in this area are quite scarce.

METHODS

To screen out suitable human autologous ooplasmic mitochondrial donor cells, we performed comprehensive assessment of mitochondrial physiology, function and metabolic capacity on a varity of autologous adipose, marrow, and urine-derived mesenchymal stromal cells (ADSC, BMSC and USC) and ovarian germline granulosa cells (GC). Further, to explore the biosafety, effect and mechanism of stem cell-derived mitochondria transfer on human early embryo development, randomized in-vitro basic studies were performed in both of the young and aged oocytes from infertile females.

RESULTS

Compared with other types of mesenchymal stromal cells, USC demonstrated a non-fused spherical mitochondrial morphology and low oxidative stress status which resembled the oocyte stage. Moreover, USC mitochondrial content, activity and function were all higher than other cell types and less affected by age, and it also exhibited a biphasic metabolic pattern similar to the pre-implantation stage of embryonic development. After the biosafety identification of the USC mitochondrial genome, early embryos after USC mitochondrial transfer showed improvements in mitochondrial content, activity, and cytoplasmic Ca2+ levels. Further, aging embryos also showed improvements in embryonic morphological indicators, euploidy rates, and oxidative stress status.

CONCLUSION

Autologous non-invasively derived USC mitochondria transfer may be an effective strategy to improve embryonic development and metabolism, especially in infertile females with advanced age or repeated pregnancy failure. It provides evidence and possibility for the autologous treatment of infertile females without invasive and ethical concerns.

Human ovarian aging is characterized by oxidative damage and mitochondrial dysfunction

STUDY QUESTION

Are human ovarian aging and the age-related female fertility decline caused by oxidative stress and mitochondrial dysfunction in oocytes?

SUMMARY ANSWER

We found oxidative damage in oocytes of advanced maternal age, even at the primordial follicle stage, and confirmed mitochondrial dysfunction in such oocytes, which likely resulted in the use of alternative energy sources.

WHAT IS KNOWN ALREADY

Signs of reactive oxygen species-induced damage and mitochondrial dysfunction have been observed in maturing follicles, and even in early stages of embryogenesis. However, although recent evidence indicates that also primordial follicles have metabolically active mitochondria, it is still often assumed that these follicles avoid oxidative phosphorylation to prevent oxidative damage in dictyate arrested oocytes. Data on the influence of ovarian aging on oocyte metabolism and mitochondrial function are still limited.

STUDY DESIGN, SIZE, DURATION

A set of 39 formalin-fixed and paraffin-embedded ovarian tissue biopsies were divided into different age groups and used for immunofluorescence analysis of oxidative phosphorylation activity and oxidative damage to proteins, lipids, and DNA. Additionally, 150 immature oocytes (90 germinal vesicle oocytes and 60 metaphase I oocytes) and 15 cumulus cell samples were divided into different age groups and used for targeted metabolomics and lipidomics analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Ovarian tissues used for immunofluorescence microscopy were collected through PALGA, the nationwide network, and registry of histo- and cytopathology in The Netherlands. Comprehensive metabolomics and lipidomics were performed by liquid-liquid extraction and full-scan mass spectrometry, using oocytes and cumulus cells of women undergoing ICSI treatment based on male or tubal factor infertility, or fertility preservation for non-medical reasons.

MAIN RESULTS AND THE ROLE OF CHANCE

Immunofluorescence imaging on human ovarian tissue indicated oxidative damage by protein and lipid (per)oxidation already at the primordial follicle stage. Metabolomics and lipidomics analysis of oocytes and cumulus cells in advanced maternal-age groups demonstrated a shift in the glutathione-to-oxiglutathione ratio and depletion of phospholipids. Age-related changes in polar metabolites suggested a decrease in mitochondrial function, as demonstrated by NAD+, purine, and pyrimidine depletion, while glycolysis substrates and glutamine accumulated, with age. Oocytes from women of advanced maternal age appeared to use alternative energy sources like glycolysis and the adenosine salvage pathway, and possibly ATP which showed increased production in cumulus cells.

LIMITATIONS, REASONS FOR CAUTION

The immature oocytes used in this study were all subjected to ovarian stimulation with high doses of follicle-stimulating hormones, which might have concealed some age-related differences.

WIDER IMPLICATIONS OF THE FINDINGS

Further studies on how to improve mitochondrial function, or lower oxidative damage, in oocytes from women of advanced maternal age, for instance by supplementation of NAD+ precursors to promote mitochondrial biogenesis, are warranted. In addition, supplementing the embryo medium of advanced maternal-age embryos with such compounds could be a treatment option worth exploring.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the Amsterdam UMC. The authors declare to have no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Moschus ameliorates glutamate-induced cellular damage by regulating autophagy and apoptosis pathway

Alzheimer's disease (AD), a neurodegenerative disorder, causes short-term memory and cognition declines. It is estimated that one in three elderly people die from AD or other dementias. Chinese herbal medicine as a potential drug for treating AD has gained growing interest from many researchers. Moschus, a rare and valuable traditional Chinese animal medicine, was originally documented in Shennong Ben Cao Jing and recognized for its properties of reviving consciousness/resuscitation. Additionally, Moschus has the efficacy of "regulation of menstruation with blood activation, relief of swelling and pain" and is used for treating unconsciousness, stroke, coma, and cerebrovascular diseases. However, it is uncertain whether Moschus has any protective effect on AD patients. We explored whether Moschus could protect glutamate (Glu)-induced PC12 cells from cellular injury and preliminarily explored their related action mechanisms. The chemical compounds of Moschus were analyzed and identified by GC-MS. The Glu-induced differentiated PC12 cell model was thought to be the common AD cellular model. The study aims to preliminarily investigate the intervention effect of Moschus on Glu-induced PC12 cell damage as well as their related action mechanisms. Cell viability, lactate dehydrogenase (LDH), mitochondrial reactive oxygen species, mitochondrial membrane potential (MMP), cell apoptosis, autophagic vacuoles, autolysosomes or autophagosomes, proteins related to apoptosis, and the proteins related to autophagy were examined and analyzed. Seventeen active compounds of the Moschus sample were identified based on GC-MS analysis. In comparison to the control group, Glu stimulation increased cell viability loss, LDH release, mitochondrial damage, loss of MMP, apoptosis rate, and the number of cells containing autophagic vacuoles, and autolysosomes or autophagosomes, while these results were decreased after the pretreatment with Moschus and 3-methyladenine (3-MA). Furthermore, Glu stimulation significantly increased cleaved caspase-3, Beclin1, and LC3II protein expression, and reduced B-cell lymphoma 2/BAX ratio and p62 protein expression, but these results were reversed after pretreatment of Moschus and 3-MA. Moschus has protective activity in Glu-induced PC12 cell injury, and the potential mechanism might involve the regulation of autophagy and apoptosis. Our study may promote research on Moschus in the field of neurodegenerative diseases, and Moschus may be considered as a potential therapeutic agent for AD.