Peroxiredoxin 4 protects against ovarian ageing by ameliorating D-galactose-induced oxidative damage in mice

Role of MFN2 in bovine embryonic development and the mitigation of ER stress

This study investigated the role of mitochondrial fusion protein-2 (MFN2) in bovine embryonic development and its relationship with endoplasmic reticulum (ER) stress, aiming to increase the efficiency of in vitro embryo culture. Western blot analysis revealed that MFN2 expression peaked at the 2-cell stage, decreased at the 4-cell stage, and gradually increased from the 6-8-cell stage to the blastocyst stage. Inhibiting MFN2 at the zygote stage reduced blastocyst formation and proliferation, and this damage was partially reversed by the ER stress protective agent TUDCA. MFN2 inhibition also led to the decreased formation of the inner cell mass (ICM) and reduced expression of the totipotent genes CDX2 and SOX2. Additionally, reactive oxygen species (ROS) levels increased following MFN2 inhibition but decreased after TUDCA treatment. The expression of antioxidative stress-related genes (SOD and CAT) was downregulated after MFN2 inhibition but upregulated following TUDCA treatment. Furthermore, MFN2 inhibition reduced ER fluorescence intensity and increased the expression of UPR signaling markers (GRP78, XBP1, CHOP, IRE1, and ATF6), indicating increased ER stress. TUDCA administration reversed these effects, restoring MFN2 levels and reducing apoptosis. In conclusion, MFN2 is essential for bovine embryonic development because it regulates ER stress and maintains cell function, with MFN2 deficiency leading to developmental disorders and cell damage. ER stress protectors such as TUDCA can effectively mitigate these negative effects, highlighting a potential strategy for improving in vitro embryo culture efficiency.

A comprehensive review of peroxiredoxin 4, a redox protein evolved in oxidative protein folding coupled with hydrogen peroxide detoxification

Peroxiredoxin (PRDX) primarily employs electrons from thioredoxin in order to reduce peroxides. PRDX4 mainly resides either in the endoplasmic reticulum (ER) lumen or in extracellular spaces. Due to the usage of alternative promoters, a first exon is transcribed from different regions of the Prdx4 gene, which results in two types of mRNAs. The first type is designated as Prdx4. It is translated with a cleavable, hydrophobic signal sequence and is expressed in most cells throughout the body. The second type is designated as Prdx4t. The peroxidase activity of PRDX4 is involved in both the reduction of hydrogen peroxides and in the oxidative folding of nascent proteins in the ER. Prdx4 appears to have evolved from an ancestral gene in Eutherians simultaneously with the evolution of sperm protamine to cysteine-rich peptides, and, therefore, the testis-specific PRDX4t is likely involved in spermatogenesis through the oxidative folding of protamine. The dysfunction of PRDX4 leads to oxidative damage and ER stress, and is related to various diseases including diabetes and cancer. In this review article we refer to the results of biological and medical research in order to unveil the functional consequences of this unique member of the PRDX family.

Dietary exposure to di(2-ethylhexyl) phthalate for 6 months alters markers of female reproductive aging in mice†

The female reproductive system ages before any other physiological system, making it a sensitive indicator of aging. Early reproductive aging is associated with the early onset of infertility and an increased risk of several diseases. During aging, systemic and reproductive oxidative stress and inflammation levels increase through inflammasome activation, leading to ovarian follicle loss. Other markers of reproductive aging include increased fibrosis and shortening of telomeres in ovarian cells. The factors that accelerate reproductive aging are unclear, but likely involve exposure to endocrine-disrupting chemicals such as phthalates. Di(2-ethylhexyl) phthalate (DEHP) is a widely used phthalate and humans are exposed to it daily. Several studies show that DEHP induces reproductive toxicity by affecting estrous cyclicity, follicle numbers, and hormone levels. However, little is known about the mechanisms underlying DEHP-induced early onset of reproductive aging. Thus, this study tested the hypothesis that dietary exposure to DEHP induces early reproductive aging by affecting inflammation, fibrosis, and the expression of telomere regulators and antioxidant enzymes. Adult CD-1 female mice were exposed to vehicle (corn oil) or DEHP (0.5, 1.5, or 1500 ppm) via the chow for 6 months. Exposure to DEHP increased the expression of antioxidant enzymes and Caspase 3, increased expression of telomere-associated genes, and increased fibrosis levels in the ovary. In addition, DEHP exposure for 6 months altered ovarian and systemic inflammatory status. Collectively, our novel data suggest that 6-month dietary exposure to DEHP may accelerate reproductive aging by affecting several reproductive aging markers in female mice.

Antioxidant therapy for infertile couples: a comprehensive review of the current status and consideration of future prospects

Oxidative stress (OS) is established as a key factor in the etiology of both male and female infertility, arising from an imbalance between reactive oxygen species (ROS) production and the endogenous antioxidant (AOX) defenses. In men, OS adversely affects sperm function by inducing DNA damage, reducing motility, significantly impairing sperm vitality through plasma membrane peroxidation and loss of membrane integrity, and ultimately compromising overall sperm quality. In women, OS is implicated in various reproductive disorders, including polycystic ovary syndrome, endometriosis, and premature ovarian failure, leading to diminished oocyte quality, disrupted folliculogenesis, and poorer reproductive outcomes. Antioxidant therapy represents a promising intervention to mitigate the harmful effects of ROS on reproductive health in additions to its easy accessibility, safety, and low cost. Despite several findings suggesting improvements in fertility potential with AOX therapy, the data remains inconclusive regarding optimal dosage and combination, duration of treatment, and the specific patient populations most likely to benefit. In this review, we discuss the role of AOXs in the management of infertile couples, focusing on their biological mechanisms, potential adverse effects, therapeutic efficacy, and clinical applications in improving reproductive outcomes in both natural conception and medically assisted reproduction. Additionally, we highlight the current practice patterns and recommendations for AOX supplementation during the course of infertility treatment. Further, we provide an overview on the limitations of the current research on the topic and insights for future studies to establish standardized AOX regimens and to assess their long-term impact on key outcomes such as live birth rates and miscarriage rates.

Characterization of microcirculatory endothelial functions in a D-Galactose-induced aging model

BACKGROUND

Microcirculation health is critical to human health, and aging is an important factor affecting microcirculation health. Although D-Galactose has been widely used in aging research models, there is a lack of relevant studies on D-Galactose simulating microcirculatory aging. Here, we explored microcirculatory endothelial function in D-Galactose-induced aging mice.

METHODS

Intraperitoneal injection of 150 mg/(kg·d) of D-Galactose was given to cause senescence in mice. Aging was evaluated by SA-β-gal (senescence-associated β-galactosidase) staining. The auricular skin and hepatic microcirculation of mice were observed and detected by enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC) and microcirculation apparatus. The aging of microcirculation was analyzed from oxidative stress, endothelial impairment, inflammation, microvascular morphology and hemodynamics.

RESULTS

In aging mice, percentage of SA-β-gal positive area, oxidative stress products reactive oxygen species (ROS) and nitric oxide (NO), endothelial impairment marker syndecan-1 (SDC-1), stromal cell derived factor-1 (SDF-1), intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the senescence-associated secretory phenotype (SASP) were all up-regulated. The tortuosity of microvessels increased in aging mice, the linear density did not change significantly, but the total length of narrow microvessels (TLNMV) increased and wide microvessels (TLWMV) decreased, speculate that vasomotor dysfunction may be present. Hemodynamically, both perfusion and velocity of blood flow were reduced in senescent mice, presumably due to endothelial dysfunction.

CONCLUSION

Microcirculatory endothelial dysfunction is induced by D-Galactose, leading to microcirculatory aging. In vivo, this is manifested by elevated levels of oxidative stress, impaired endothelial glycocalyx (eGC), and a greater production of chemokines and adhesive molecules. These changes cause vasomotor dysfunction and remodeling, ultimately leading to hemodynamic impairment.

Bushen Jianpi Tiaoxue Decoction (BJTD) ameliorates oxidative stress and apoptosis induced by uterus ageing through activation of the SIRT1/NRF2 pathway

BACKGROUND

Uterus ageing is a crucial factor contributing to decreased fertility in older women and is also implicated in menstrual disorders, endometritis, and adenomyosis. Bushen Jianpi Tiaoxue Decoction (BJTD) is a traditional Chinese medicine formulation used to ameliorate endocrine disorders in the female reproductive system and finds extensive application in ageing-related endometrial diseases. However, the mechanisms underlying its improvement of uterus ageing have not been thoroughly investigated.

PURPOSE

To explore the potential components and mechanisms of BJTD in ameliorating uterus ageing through network pharmacology, in vivo, and in vitro experiments.

METHODS

Morphological changes were observed using hematoxylin and eosin staining, collagen deposition was assessed using Masson staining, and apoptotic-related molecules were detected using Western blot. After determining the modeling doses, BJTD intervention was administered at two doses, and the expression of oxidative stress and apoptosis-related genes and proteins was measured. The levels of cellular apoptosis were evaluated using the TUNEL assay kit and Annexin V/FITC-PI assay kit. The main components of BJTD were determined by UPLC-MS, and the potential targets and mechanisms of BJTD action were explored using network pharmacology and molecular docking. BJTD-Containing Serum (BJTD-S) was extracted and applied in vitro experiments using human endometrial stroma cells (hESC) to preliminarily identify the pathways affected.

RESULTS

We demonstrated that modeling with 600 mg/kg/day D-Gal for 5 weeks significantly increased collagen deposition in uterine tissues, particularly in the glands and stroma. Additionally, it significantly elevated the levels of TNF-α and IL-1β and increased the expression of p53 and BAX while decreasing BCL-2 expression. BJTD significantly reduced the increased levels of TNF-α and IL-1β induced by D-Gal, and modulated oxidative stress markers such as SOD, MDA, GSH-Px, and T-AOC. BJTD also inhibited the cascade activation of apoptosis induced by D-Gal, suppressing the expression of cleaved-Caspase 8, cleaved-Caspase 3, and BAX. SIRT1 is a potential target of BJTD action. In vitro experiments showed that BJTD-S significantly improved D-Gal-induced apoptosis in hESC cells, and the expression levels of SIRT1, NRF2, and HO-1 were significantly decreased in D-Gal-induced hESC, and BJTD-S significantly increased their expression.

CONCLUSION

BJTD can ameliorate oxidative stress and cell apoptosis levels in D-Gal-induced uterine aging, and its active ingredients can activate the SIRT1/NRF2 pathway to exert its effects. Importantly, our study provides novel insights into the molecular mechanisms by which traditional Chinese medicine influence uterus ageing. By specifically targeting the SIRT1/NRF2 pathway, BJTD presents a unique therapeutic approach that has not been extensively explored in previous studies, marking a significant advancement in the treatment of uterus ageing.

PRDX4 mitigates diabetic retinopathy by inhibiting reactive gliosis, apoptosis, ER stress, oxidative stress, and mitochondrial dysfunction in Müller cells

Diabetic retinopathy (DR) is a neurovascular complication of diabetes. As a crucial player in the retinal physiology, Müller cells are affected in DR, impairments of Müller cell function lead to retinal malfunctions. Therefore, searching for approaches to mitigate diabetes-induced injury in Müller cells is imperative for delaying DR. Peroxiredoxin 4 (PRDX4), an important endoplasmic reticulum (ER)-resident antioxidant, was explored in this study for its potential protective role against DR. Streptozotocin-induced mouse model of diabetes and high glucose (HG)-induced Müller cells were utilized to assess the impact of PRDX4. Compared with WT mice, PRDX4 knockout exacerbated retinal neurodegeneration, reactive gliosis, cell apoptosis, ER stress, oxidative stress, and mitochondrial dysfunction in diabetic retinas. Knockdown of PRDX4 aggravated HG-induced reactive gliosis, apoptosis, ER stress, oxidative stress, and mitochondrial dysfunction in Müller cells. Conversely, PRDX4 overexpression in Müller cells protected against HG-induced cell damage. Mechanistically, PRDX4 promoted the degradation of dipeptidyl peptidase-4, which is associated with DR in type 1 diabetics, thereby alleviating HG-stimulated Müller cell abnormalities. Our study indicated that PRDX4 is a crucial protective regulator in DR progression via destabilization of dipeptidyl peptidase-4 protein and suggested that enhancement of PRDX4 level may represent a promising approach for treating DR.

TET1 overexpression affects cell proliferation and apoptosis in aging ovaries

PURPOSE

Along with the progress of society, human life expectancy has been increasing, and late marriage and late childbearing are the current trend. Since reproductive aging affects fertility, ovarian aging in women has become a major reproductive health issue in the current society. During ovarian aging, DNA methylation levels may change. The ten-eleven translocation (TET) protein family proteins TET1, TET2, and TET3 are important DNA demethylation enzymes, and differential expression of TET1, TET2, and TET3 may affect the proliferation and apoptosis of aging ovarian cells. The aim of this study was to investigate the role of TET1 in the regulation of ovarian aging.

METHODS

The expression of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) was analyzed by immunofluorescence (IF) in young and aging ovaries of six 6-8-week-old female mice and six 6-8-month-old female mice. Then, the expression pattern of the TET protein family in young and aging ovaries of mice was investigated. To determine the impact of TET1 on ovarian development, the aging of IOSE-80, KGN, and SKOV-3 cells was induced with D-galactosidase (D-gal). Cells were then transfected using the TET1 overexpression vector or si-TET1. We assessed the proliferation and apoptosis of aging cells after transfection and analyzed the regulatory effect of TET1 expression on aging cells. Additionally, we verified the Tet1 expression in Tet1-KO mice.

RESULTS

The 5mC to 5hmC transition, oocyte maturation, and blastocyst rate were reduced in aging mice compared to young mice. In aging mice ovaries, the expression levels of Tet1, Tet2, and Tet3 were reduced significantly, with Tet1 being particularly pronounced. The overexpression of TET1 promoted proliferation and inhibited apoptosis in aging human ovarian cells. Furthermore, Tet1 expression was very low in Tet1-KO C57BL/6 J mice ovaries.

CONCLUSION

This study demonstrates that the expression levels of TET family proteins are low in aging ovaries, and the overexpression of TET1 can promote proliferation and inhibit apoptosis in aging ovarian cells.

Trehalose Alleviates D-Galactose-Induced Aging-Related Granulosa Cell Death in Ovaries

Ovarian dysfunction caused by aging restricts female reproductive capacity and is accompanied by oxidative stress and impaired autophagy. Recent studies have shown that trehalose (Tre) can activate autophagy and have antioxidant effects. However, whether Tre can be used to attenuate ovarian aging remains unclear. Therefore, the anti-aging effects of Tre on the ovary were explored both in vivo and in vitro. D-galactose (D-gal) was administered i.p. daily (200 mg/kg body weight) for 8 weeks to establish the mouse ovarian aging model (n = 10). We found that Tre significantly reversed ovarian weight loss and reduced the number of TUNEL-positive granulosa cells caused by D-gal in mouse ovaries. Tre elevated the protein expression levels of LC3-II, Parkin, PINK1, Beclin1, and LAMP2 in ovaries. Mitochondrial-related proteins TOM20 and COX IV expression levels were increased by Tre administration. In vitro studies further supported these findings, showing that Tre treatment significantly reduced the number of SA-β-gal and PI-positive cells, and decreased ROS levels in cultured granulosa cells. Thus, Tre alleviates ovarian aging by activating mitophagy and reducing oxidative stress, suggesting its potential as an anti-aging agent for ovarian health.

Peroxiredoxin 4 Ameliorates T-2 Toxin-Induced Growth Retardation in GH3 Cells by Inhibiting Oxidative Stress and Apoptosis

T-2 toxin, a highly toxic type A trichothecene, is a secondary fungal metabolite produced by various Fusarium species. The consumption of food and feed contaminated with T-2 toxin is a major factor contributing to growth retardation, posing significant risks to both human and animal health. However, the specific targets and mechanisms that mitigate T-2 toxin-induced growth retardation remain unclear. In this study, transcriptomic analysis was employed to identify key differentially expressed genes associated with the alleviation of T-2 toxin-induced growth retardation. Peroxiredoxin 4 (PRDX4), a gene linked to oxidative stress and apoptosis, was found to be one of the most downregulated in T-2 toxin-treated GH3 cells, an in vitro model of growth retardation. The experiments demonstrated that T-2 toxin significantly increased reactive oxygen species' production, apoptosis, and cell cycle arrest while reducing the activity of antioxidant enzymes (superoxide dismutase and glutathione peroxidase) and PRDX4 expression in GH3 cells. Furthermore, PRDX4 silencing exacerbated T-2 toxin-induced oxidative stress and apoptosis, whereas PRDX4 overexpression effectively mitigated these effects. These findings highlight the protective role of PRDX4 in counteracting T-2 toxin-induced oxidative stress and apoptosis, suggesting that PRDX4 can serve as a therapeutic target for the treatment of T-2 toxin-induced growth retardation.

Stem cell transplantation extends the reproductive life span of naturally aging cynomolgus monkeys

The ovary is crucial for female reproduction and health, as it generates oocytes and secretes sex hormones. Transplantation of mesenchymal stem cells (MSCs) has been shown to alleviate pathological ovarian aging. However, it is unclear whether MSCs could benefit the naturally aging ovary. In this study, we first examined the dynamics of ovarian reserve of Chinese women during perimenopause. Using a naturally aging cynomolgus monkey (Macaca fascicularis) model, we found that transplanting human embryonic stem cells-derived MSC-like cells, which we called M cells, into the aging ovaries significantly decreased ovarian fibrosis and DNA damage, enhanced secretion of sex hormones and improved fertility. Encouragingly, a healthy baby monkey was born after M-cell transplantation. Moreover, single-cell RNA sequencing analysis and in vitro functional validation suggested that apoptosis, oxidative damage, inflammation, and fibrosis were mitigated in granulosa cells and stromal cells following M-cell transplantation. Altogether, these findings demonstrate the beneficial effects of M-cell transplantation on aging ovaries and expand our understanding of the molecular mechanisms underlying ovarian aging and stem cell-based alleviation of this process.

Deer Blood Hydrolysate Protects against D-Galactose-Induced Premature Ovarian Failure in Mice by Inhibiting Oxidative Stress and Apoptosis

BACKGROUND

Premature ovarian failure (POF) is a common disease among women, which can cause many complications and seriously threaten women's physical and mental health. Currently, hormone replacement therapy is the primary treatment for premature ovarian failure. However, the side effects are serious and will increase the chance of breast cancer and endometrial cancer. Deer blood hydrolysate (DBH) is the product of enzymatic hydrolysis of deer blood, has antioxidant, anti-ageing, and anti-fatigue effects, and has the potential to improve premature ovarian failure.

METHODS

In our experiment, a mouse model of premature ovarian failure was established through intraperitoneal injection of 400 mg/kg/d of D-gal for 42 days. At the same time, different doses of DBH were gavaged to observe its ameliorative effect on premature ovarian failure.

RESULTS

The experimental findings indicated that DBH could restore the irregular oestrus cycle of POF mice, improve the abnormal amounts in serum hormones follicle-stimulating hormone (FSH), luteinising hormone (LH), progesterone (P) and estradiol (E2), increase the number of primordial follicles and decrease the number of atretic follicles. In addition, DBH also raised the level of superoxide dismutase (SOD) and reduced the level of malondialdehyde (MDA) and reduced the apoptosis of ovarian granulosa cells in mice. The WB assay results showed that gavage of DBH restored the decrease in the indication of nuclear factor erythroid 2-related factor 2 (Nrf2), Heme Oxygenase-1 (Ho-1), and B-cell lymphoma-2 (Bcl-2) proteins and reduced the elevated expression of Kelch-like ECH-associated protein 1 (Keap1), Bcl-2 associated X protein (Bax), and Cysteinyl aspartate specific proteinase-3 (Caspase-3) proteins that were induced by D-gal.

CONCLUSIONS

To sum up, the present research indicated that DBH can ameliorate D-gal-induced oxidative stress and apoptosis by regulating the Nrf2/HO-1 signalling pathway and the Bcl-2/Bax/caspase-3 apoptosis pathway, which can be used for further development as a nutraceutical product to improve premature ovarian failure.

Peroxiredoxin 4 deficiency induces accelerated ovarian aging through destroyed proteostasis in granulosa cells

Ovarian aging, a complex and challenging concern within the realm of reproductive medicine, is associated with reduced fertility, menopausal symptoms and long-term health risks. Our previous investigation revealed a correlation between Peroxiredoxin 4 (PRDX4) and human ovarian aging. The purpose of this research was to substantiate the protective role of PRDX4 against ovarian aging and elucidate the underlying molecular mechanism in mice. In this study, a Prdx4-/- mouse model was established and it was observed that the deficiency of PRDX4 led to only an accelerated decline of ovarian function in comparison to wild-type (WT) mice. The impaired ovarian function observed in this study can be attributed to an imbalance in protein homeostasis, an exacerbation of endoplasmic reticulum stress (ER stress), and ultimately an increase in apoptosis of granulosa cells. Furthermore, our research reveals a noteworthy decline in the expression of Follicle-stimulating hormone receptor (FSHR) in aging Prdx4-/- mice, especially the functional trimer, due to impaired disulfide bond formation. Contrarily, the overexpression of PRDX4 facilitated the maintenance of protein homeostasis, mitigated ER stress, and consequently elevated E2 levels in a simulated KGN cell aging model. Additionally, the overexpression of PRDX4 restored the expression of the correct spatial conformation of FSHR, the functional trimer. In summary, our research reveals the significant contribution of PRDX4 in delaying ovarian aging, presenting a novel and promising therapeutic target for ovarian aging from the perspective of endoplasmic reticulum protein homeostasis.

Lycium barbarum berry extract improves female fertility against aging-related oxidative stress in the ovary

Reproductive aging in female mammals is characterized by ovarian senescence, leading to a significant fertility decline. Lycium barbarum berry, or goji berry, is a food and medicine that appears in various formulas for treating infertility in traditional Chinese medicine. We investigated the function of an aqueous extract of Lycium barbarum berry (LB extract) to improve health status, fertility, and offspring development during female aging. Aged female mice were supplemented with LB extract, and its effects on fertility, locomotor activity, and offspring development were assessed. The results demonstrated that LB extract significantly increased pregnancy and live birth rates in naturally aged female mice. It also effectively improved aged animals' locomotor activity. Moreover, LB extract promoted the growth and development of offspring delivered from the aged animals and reduced the offspring's anxiety. During aging, fertility-related hormones gradually decline. However, the decline of anti-Müllerian hormone (AMH) and estradiol (E2) in the serum of aged mice was restored by LB extract supplementation. Immunohistochemical analysis revealed that the levels of oxidation and the inflammatory IL-6 in intra-ovarian cells were reduced by LB extract, while the antioxidant-associated proteins peroxiredoxin 4 (PRDX4) and nuclear factor erythroid 2-related factor 2 (NRF2) were increased. Bioinformatics analysis revealed a decline in egg PRDX4 expression with age across various species. This suggests that the antioxidant function protected by LB extract through PRDX4 may consistently promote fertility enhancement by improving ovarian function across different species. Importantly, LB extract did not induce significant adverse effects on aged female mice and their offspring. These findings highlight the potential of LB as a protective agent against ovarian oxidative stress, which preserves ovarian function and improves fertility rates in naturally senescent females.

Pterostilbene, a Resveratrol Derivative, Improves Ovary Function by Upregulating Antioxidant Defenses in the Aging Chickens via Increased SIRT1/Nrf2 Expression

Oxidative stress is recognized as a prominent factor contributing to follicular atresia and ovarian aging, which leads to decreased laying performance in hens. Reducing oxidative stress can improve ovarian function and prolong the laying period in poultry. This study investigates the impact of Pterostilbene (PTS), a natural antioxidant, on ovarian oxidative stress in low-laying chickens. Thirty-six Hy-Line White laying chickens were evenly divided into four groups and fed diets containing varying doses of PTS for 15 consecutive days. The results showed that dietary supplementation with PTS significantly increased the laying rate, with the most effective group exhibiting a remarkable 42.7% increase. Furthermore, PTS significantly enhanced the antioxidant capacity of aging laying hens, as evidenced by increased levels of glutathione, glutathione peroxidase, superoxide dismutase, catalase, and total antioxidant capacity in the ovaries, livers, and serum. Subsequent experiments revealed decreased expressions of Bax, Caspase-3, and γ-H2AX, along with an increased expression of BCL-2 in the ovaries and livers of laying hens. PTS supplementation also positively affects fat metabolism by reducing abdominal fat accumulation and promoting fat transfer from the liver to the ovary. To elucidate the mechanism underlying the effects of PTS on ovarian function, a series of in vitro experiments were conducted. These in vitro experiments revealed that PTS pretreatment restored the antioxidant capacity of D-galactose-induced small white follicles by upregulating SIRT1/Nrf2 expression. This protective effect was inhibited by EX-527, a specific inhibitor of SIRT1. These findings suggest that the natural antioxidant PTS has the potential to regulate cell apoptosis and fat metabolism in laying chickens by ameliorating oxidative stress, thereby enhancing laying performance.

Nur77 improves ovarian function in reproductive aging mice by activating mitophagy and inhibiting apoptosis

Reproductive aging not only affects the fertility and physical and mental health of women but also accelerates the aging process of other organs. There is an urgent need newfor novel mechanisms, targets, and drugs to break the vicious cycle of mitochondrial dysfunction, redox imbalance, and germ cell apoptosis associated with ovarian aging. Autophagy, recognized as a longevity mechanism, has recently become a focal point in anti-aging research. Although mitophagy is a type of autophagy, its role and regulatory mechanisms in ovarian aging, particularly in age-related ovarian function decline, remain unclear. Nerve growth factor inducible gene B (Nur77) is an early response gene that can be stimulated by oxidative stress, DNA damage, metabolism, and inflammation. Recent evidence recommends that decreased expression of Nur77 is associated with age-related myocardial fibrosis, renal dysfunction, and Parkinson's disease; however, its association with ovarian aging has not been studied yet. We herein identified Nur77 as a regulator of germ cell senescence, apoptosis, and mitophagy and found that overexpression of Nur77 can activate mitophagy, improve oxidative stress, reduce apoptosis, and ultimately enhance ovarian reserve in aged mice ovaries. Furthermore, we discovered an association between Nur77 and the AKT pathway through String and molecular docking analyses. Experimental confirmation revealed that the AKT/mTOR signaling pathway is involved in the regulation of Nur77 in ovarian function. In conclusion, our results suggest Nur77 as a promising target for preventing and treating ovarian function decline related to reproductive aging.

Integrating network pharmacology with experimental validation to investigate the mechanism of Wuwei Zishen formula in improving perimenopausal syndrome

OBJECTIVES

To investigate the role of the Wuwei Zishen formula (WWZSF) in treating and preventing perimenopausal syndrome (PMS) and to understand its mechanism.

METHODS

Network pharmacology and molecular docking was used to predict active compounds, potential targets, and pathways for PMS treatment using WWZSF. Female Sprague-Dawley (SD) rats were induced with D-galactose (D-gal) to establish a PMS model and treated with Kunbao pill (KBP) and WWZSF. Estrus cycles were observed using vaginal smears. Serum sex hormones were measured using the enzyme-linked immunosorbent assay (ELISA). Histological changes in the uterus and ovaries were evaluated using hematoxylin-eosin staining (HE). Western blot was used to assess the protein expression levels of Cleaved Caspase-3, p62, BAX/Bcl-2, p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR in the uterus and ovaries.

RESULTS

A total of 70 active compounds and 440 potential targets were screened out. Important targets and pathways, including AKT1, Bcl-2, Caspase-3, mTOR, and the PI3K/AKT/mTOR pathways, and molecular docking verified their high affinities to key WWZSF components. In vivo experiments showed that WWZSF can ameliorate the morphological abnormalities of the uterus and ovaries, increase sex hormone levels and organ index, and restore the estrus cycles in PMS rats. Moreover, the western blot results showed decreased Cleaved Caspase-3 and BAX/Bcl-2 protein levels in the ovarian and uterine tissues after WWZSF therapy. Concurrently, there was an increase in the expression of p62 and the ratios of p-AKT/AKT, p-mTOR/mTOR, and p-PI3K/PI3K.

CONCLUSION

The PI3K/AKT/mTOR signaling pathway-mediated apoptosis and autophagy pathways may be how WWZSF efficiently reduces PMS.

Honghua Xiaoyao tablet combined with estradiol improves ovarian function in D-galactose-induced aging mice by reducing apoptosis and affecting the release of reproductive hormones: an in vivo study

Context: It is very necessary to delay ovarian aging and prevent age-related health problems. The active ingredient in Honghua Xiaoyao tablet (HHXYT) has the effects of anti-oxidation, anti-inflammation, immune regulation and so on. Objective: To explore the effect and mechanism of Honghua Xiaoyao tablet on aging model mice. Materials and methods: The aging model was established by intraperitoneal injection of D-galactose in model mice. The mice in the HHXYT-L,M,H group were given 0.3 g/kg, 0.6 g/kg and 1.2 g/kg Honghua Xiaoyao tablet suspension respectively, and the HHXYT-M + E2 group was given 0.6 g/kg HHXYT +0.13 mg/kg estradiol valerate for 30 days. In this study, ELISA, HE, Western blot, IH and TUNEL were used. Results: HHXYT + E2 can improve the gonadal index, estrous cycle of aging mice. In HHXYT-M + E2 group, the level of FSH and LH decreased, while E2 and AMH increased significantly. The number of growing follicles in HHXYT-M + E2 group increased, which was better than that of HHXYT alone. Western blot results showed that HHXYT-M + E2 group decreased the expression of Bax, cleaved-Parp, cleaved-Casp-3 and CytC molecules and increased the expression of Bcl-2 in ovarian tissue. FSHR expression decreased in model group and increased in HHXYT group. TUNEL staining showed that the number of apoptotic cells in HHXYT group was reduced, and the HHXYT-M + E2 group was the most significantly. Discussion and conclusion: HHXYT can improve the level of sex hormones and increase the number of growing follicles in aging mice. HHXYT-M + E2 group has the best effect, and its mechanism may be related to reducing ovarian granulosa cell apoptosis.

Indole-3-carbinol ameliorates ovarian damage in female old mice through Nrf2/HO-1 pathway activation

Ovarian aging leads to infertility and birth defects. We aimed to clarify the role of Indole-3-carbinol (I3C) in resistance to oxidative stress, apoptosis, and fibrosis in ovarian aging. I3C was administered via intraperitoneal injection for 3 weeks in young or old mice. Immunohistochemistry; Masson, Sirius red, and TUNEL staining; follicle counting; estrous cycle analysis; and Western blotting were used for validating the protective effect of I3C against ovarian senescence. Human granulosa-like tumor cell line and primary granulosa cells were used for in vitro assay. The results indicated that I3C inhibited ovarian fibrosis and apoptosis while increasing the number of primordial follicles. Mechanistic studies have shown that I3C promoted the nuclear translocation of nuclear factor-erythroid 2-related factor (Nrf2) and upregulated the expression of heme oxygenase 1 (HO-1). Additionally, I3C increased cell viability and decreased lactate dehydrogenase, malondialdehyde, reactive oxygen species and JC-1 levels. Furthermore, the antioxidant effect of I3C was found to be dependent on the activation of Nrf2 and HO-1, as demonstrated by the disappearance of the effect upon inhibition of Nrf2 expression. In conclusion, I3C can alleviate the ovarian damage caused by aging and may be a protective agent to delay ovarian aging.

Short-term regulation of TSFM level does not alter amyloidogenesis and mitochondrial function in type-specific cells

BACKGROUND

Mitochondrial Ts translation elongation factor (TSFM) is an enzyme that catalyzes exchange of guanine nucleotides. By forming a complex with mitochondrial Tu translation elongation factor (TUFM), TSFM participates in mitochondrial protein translation. We have previously reported that TUFM regulates translation of beta-site APP cleaving enzyme 1 (BACE1) via ROS (reactive oxygen species)-dependent mechanism, suggesting a potential role in amyloid precursor protein (APP) processing associated with Alzheimer's disease (AD), which led to the speculation that TSFM may regulate APP processing in a similar way to TUFM.

METHODS AND RESULTS

Here, we report that in cultured cells, knockdown or overexpression TSFM did not change protein levels in BACE1 and APP. Besides, the levels of cytoplasmic ROS and mitochondrial superoxide, in addition to ATP level, cell viability and mitochondrial membrane potential were not significantly altered by TSFM knockdown in the short term. Further transcriptome analysis revealed that expression of majority of mitochondrial genes were not remarkably changed by TSFM silencing. The possibility of TSFM involved in cardiomyopathy and cancer development was uncovered using bioinformatics analysis.

CONCLUSIONS

Collectively, short-term regulation of TSFM level in cultured cells does not cause a significant change in proteins involved in APP processing, levels in ROS and ATP associated with mitochondrial function. Whereas our study could contribute to comprehend certain clinical features of TSFM mutations, the roles of TSFM in cardiomyopathy and cancer development might deserve further investigation.

N-Acetylcysteine Alleviates D-Galactose-Induced Injury of Ovarian Granulosa Cells in Female Rabbits by Regulating the PI3K/Akt/mTOR Signaling Pathway

The ovary plays a crucial role in the reproductive system of female animals. Ovarian problems such as ovarian insufficiency, premature aging, polycystic ovary syndrome, and ovarian cysts may lead to ovulation disorders, abnormal hormone secretion, or luteal dysfunction, thereby increasing the risk of infertility and abortion. Only when the ovarian function and other organs in the reproductive system remain healthy and work normally can female animals be ensured to carry out reproductive activities regularly, improve the pregnancy rate and litter size, promote the healthy development of the fetus, and then improve their economic value. The follicle, as the functional unit of the ovary, is composed of theca cells, granulosa cells (GCs), and oocytes. GCs are the largest cell population and main functional unit in follicles and provide the necessary nutrients for the growth and development of follicles. N-acetylcysteine (NAC) is a prevalent and cell-permeable antioxidant molecule that effectively prevents apoptosis and promotes cellular survival. Over the past few years, its function in boosting reproductive performance in animals at the cellular level has been widely acknowledged. However, its specific role and mechanism in influencing GCs is yet to be fully understood. The objective of this study was to examine the effects of NAC on ovarian damage in female rabbits. For this purpose, D-galactose (D-gal) was first used to establish a model of damaged GCs, with exposure to 1.5 mg/mL of D-gal leading to substantial damage. Subsequently, varying concentrations of NAC were introduced to determine the precise mechanism through which it influences cell damage. Based on the results of the Cell Counting Kit-8 assay, flow cytometry, and Western blotting, it was found that 0.5 mg/mL of NAC could significantly suppress cell apoptosis and promote proliferation. In particular, it decreased the expression levels of Bax, p53, and Caspase-9 genes, while concurrently upregulating the expression of the BCL-2 gene. Moreover, NAC was found to alleviate intracellular oxidative stress, suppress the discharge of mitochondrial Cytochrome c, and boost the enzymatic activities of CAT (Catalase), GSH (Glutathione), and SOD (Superoxide dismutase). RNA sequencing analysis subsequently underscored the critical role of the PI3K/Akt/mTOR pathway in governing proliferation and apoptosis within GCs. These findings demonstrated that NAC could significantly influence gene expression within this pathway, thereby clarifying the exact relationship between the PI3K/Akt/mTOR signaling cascade and the underlying cellular processes controlling proliferation and apoptosis. In conclusion, NAC can reduce the expression of Bax, p53, and Caspase-9 genes, inhibit the apoptosis of GCs, improve cell viability, and resist D-gal-induced oxidative stress by increasing the activity of CAT, GSH, and SOD. The molecular mechanism of NAC in alleviating D-gal-induced ovarian GC injury in female rabbits by regulating the PI3K/Akt/mTOR signaling pathway provides experimental evidence for the effect of NAC on animal reproductive function at the cellular level.

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.

[Gly14]-humanin exerts a protective effect against D-galactose-induced primary ovarian insufficiency in mice

RESEARCH QUESTION

Is there a protective effect of the humanin derivative [Gly14]-humanin (HNG) on a D-gal-induced mouse model of primary ovarian insufficiency (POI), and what is the underlying mechanism?

DESIGN

D-gal (200 mg/kg/day) was injected subcutaneously for 6 weeks to induce the mouse POI model. Mice treated with HNG were injected intraperitoneally with different concentrations for 6 weeks. Ovarian morphology, function, levels of sex hormones and states of oxidative stress in the ovary and body were evaluated.

RESULTS

Compared with the D-gal group, 10 mg/kg HNG improved the abnormal ovarian morphology and oestrous cycle (P = 0.0036), increased the number of ovarian follicles (P = 0.0016) and litters (P = 0.0127), and increased the levels of oestrogen (P = 0.0043) and AMH (P = 0.0147). Antioxidant indicators in the ovaries and serum of mice, including total antioxidant capacity (P = 0.0004 and P = 0.0032, respectively), catalase (P = 0.0173 and P = 0.0103, respectively) and glutathione (both P < 0.0001) were significantly increased. The oxidation indicator malondialdehyde decreased significantly (all P < 0.01). Apoptosis of ovarian granulosa cells was significantly reduced (P = 0.0140) as was the expression of senescence-related proteins p53, p21 and p16 (all P < 0.01). The level of autophagy in ovarian tissue of mice treated with high increased (significantly increased LC3 protein [P < 0.0001] and significantly reduced p62 protein [P = 0.0007]).

CONCLUSIONS

HNG inhibited D-gal-induced oxidative stress, apoptosis and ovarian damage, promoting ovarian autophagy. HNG may be a potential prophylactic agent against POI.

Metformin protects ovarian granulosa cells in chemotherapy-induced premature ovarian failure mice through AMPK/PPAR-γ/SIRT1 pathway

Premature ovarian failure (POF) caused by chemotherapy is a growing concern for female reproductive health. The use of metformin (MET), which has anti-oxidative and anti-inflammatory effects, in the treatment of POF damaged by chemotherapy drugs remains unclear. In this study, we investigated the impact of MET on POF caused by cyclophosphamide (CTX) combined with busulfan (BUS) and M1 macrophages using POF model mice and primary granule cells (GCs). Our findings demonstrate that intragastric administration of MET ameliorates ovarian damage and alleviates hormonal disruption in chemotherapy-induced POF mice. This effect is achieved through the reduction of inflammatory and oxidative stress-related harm. Additionally, MET significantly relieves abnormal inflammatory response, ROS accumulation, and senescence in primary GCs co-cultured with M1 macrophages. We also observed that this protective role of MET is closely associated with the AMPK/PPAR-γ/SIRT1 pathway in cell models. In conclusion, our results suggest that MET can protect against chemotherapy-induced ovarian injury by inducing the expression of the AMPK pathway while reducing oxidative damage and inflammation.

Analysis of the Differentially Expressed Proteins in Donkey Milk in Different Lactation Stages

Proteins in donkey milk (DM) have special biological activities. However, the bioactive proteins and their expression regulation in donkey milk are still unclear. Thus, the differentially expressed proteins (DEPs) in DM in different lactation stages were first investigated by data-independent acquisition (DIA) proteomics. A total of 805 proteins were characterized in DM. The composition and content of milk proteins varied with the lactation stage. A total of 445 candidate DEPs related to biological processes and molecular functions were identified between mature milk and colostrum. The 219 down-regulated DEPs were mainly related to complement and coagulation cascades, staphylococcus aureus infection, systemic lupus erythematosus, prion diseases, AGE-RAGE signaling pathways in diabetic complications, and pertussis. The 226 up-regulated DEPs were mainly involved in metabolic pathways related to nutrient (fat, carbohydrate, nucleic acid, and vitamin) metabolism. Some other DEPs in milk from the lactation period of 30 to 180 days also had activities such as promoting cell proliferation, promoting antioxidant, immunoregulation, anti-inflammatory, and antibacterial effects, and enhancing skin moisture. DM can be used as a nutritional substitute for infants, as well as for cosmetic and medical purposes. Our results provide important insights for understanding the bioactive protein differences in DM in different lactation stages.

Developmental expression of peroxiredoxin gene family in early embryonic development of Xenopus tropicalis

Peroxidase genes (Prdx) encode a family of antioxidant proteins, which can protect cells from oxidative damage by reducing various cellular peroxides. This study investigated the spatiotemporal expression patterns of gene members in this family during the early development of Xenopus tropicalis. Real-time quantitative PCR showed that all members of this gene family have a distinct temporal expression pattern during the early development of X. tropicalis embryos. Additionally, whole mount in situ hybridization revealed that individual prdx genes display differential expression patterns, with overlapping expression in lymphatic vessels, pronephros, proximal tubule, and branchial arches. This study provides a basis for further study of the function of the prdx gene family.

Paxillin knockout in mouse granulosa cells increases fecundity†

Paxillin is an intracellular adaptor protein involved in focal adhesions, cell response to stress, steroid signaling, and apoptosis in reproductive tissues. To investigate the role of paxillin in granulosa cells, we created a granulosa-specific paxillin knockout mouse model using Cre recombinase driven by the Anti-Müllerian hormone receptor 2 gene promoter. Female granulosa-specific paxillin knockout mice demonstrated increased fertility in later reproductive age, resulting in higher number of offspring when bred continuously up to 26 weeks of age. This was not due to increased numbers of estrous cycles, ovulated oocytes per cycle, or pups per litter, but this was due to shorter time to pregnancy and increased number of litters in the granulosa-specific paxillin knockout mice. The number of ovarian follicles was not significantly affected by the knockout at 30 weeks of age. Granulosa-specific paxillin knockout mice had slightly altered estrous cycles but no difference in circulating reproductive hormone levels. Knockout of paxillin using clustered regularly interspaced short palindromic repeat-associated protein 9 (CRISPR-Cas9) in human granulosa-derived immortalized KGN cells did not affect cell proliferation or migration. However, in cultured primary mouse granulosa cells, paxillin knockout reduced cell death under basal culture conditions. We conclude that paxillin knockout in granulosa cells increases female fecundity in older reproductive age mice, possibly by reducing granulosa cell death. This study implicates paxillin and its signaling network as potential granulosa cell targets in the management of age-related subfertility.

Development of novel celastrol-ligustrazine hybrids as potent peroxiredoxin 1 inhibitors against lung cancer

The disruption of oxidation-reduction equilibrium through inhibiting reactive oxygen species (ROS) clearance or enhancing ROS production has emerged as a novel and promising strategy for cancer therapy. Herein, a series of celastrol-ligustrazine hybrids were designed and synthesized as effective ROS promoters, and their biological activities were further evaluated. Among them, compound 7e stood out as the most potent peroxiredoxin 1 (PRDX1) inhibitor (IC50 = 0.164 μM), which was significant super to the recognized PRDX1 inhibitor Conoidin A (IC50 = 14.80 μM) and the control compound celastrol (IC50 = 1.622 μM). Furthermore, 7e dramatically promoted intracellular ROS accumulation, and inhibited the proliferation, invasion and migration of cancer cells besides inducing apoptosis in vitro. Additionally, 7e suppressed the key signaling pathways (AKT and ERK) and promoted the expression of apoptosis-related proteins (cleaved caspase-3/8 and cleaved PARP) in A549 cells, which resulted in the prevention of tumor progression. Most importantly, compound 7e (TGI = 77.47%) showed more considerable in vivo antitumor efficacy and less toxicity than celastrol (TGI = 71.00%). Overall, this work indicates 7e as the most potential PRDX1 inhibitor and may be a promising candidate for the therapy of lung cancer.

Endoplasmic reticulum stress and alterations of peroxiredoxins in aged hearts

Aging-related cardiovascular disease is influenced by multiple factors, with oxidative stress being a key contributor. Aging-induced endoplasmic reticulum (ER) stress exacerbates oxidative stress by impairing mitochondrial function. Furthermore, a decline in antioxidants, including peroxiredoxins (PRDXs), augments the oxidative stress during aging. To explore if ER stress leads to PRDX degradation during aging, young adult (3 mo.) and aged (24 mo.) male mice were studied. Treatment with 4-phenylbutyrate (4-PBA) was used to alleviate ER stress in young adult and aged mice. Aged hearts showed elevated oxidative stress levels compared to young hearts. However, treatment with 4-PBA to attenuate ER stress reduced oxidative stress in aged hearts, indicating that ER stress contributes to increased oxidative stress in aging. Moreover, aging resulted in reduced levels of peroxiredoxin 3 (PRDX3) in mitochondria and peroxiredoxin 4 (PRDX4) in myocardium. While 4-PBA treatment improved PRDX3 content in aged hearts, it did not restore PRDX4 content in aged mice. These findings suggest that ER stress not only leads to mitochondrial dysfunction and increased oxidant stress but also impairs a vital antioxidant defense through decreased PRDX3 content. Additionally, the results suggest that PRDX4 may contribute an upstream role in inducing ER stress during aging.

SIRT6 reduces the symptoms of premature ovarian failure and alleviates oxidative stress and apoptosis in granulosa cells by degrading p66SHC via H3K9AC

CONTEXT

Substantial evidence suggests that ovarian oxidative stress can result in severe ovarian dysfunction.

OBJECTIVE

The purpose of this article is to investigate the potential of SIRT6 in alleviating premature ovarian failure (POF) by inhibiting oxidative stress.

METHODS

To mimic POF, mice were administered daily subcutaneous injections of d-galactose. The levels of E2, FSH, LH, AMH, and progesterone in serum were measured, along with changes in follicles and SIRT6 levels. Mice were treated with the SIRT6 agonist MDL-800, SIRT6 levels, follicles, and aforementioned hormones were reassessed. The effects of MDL-800 on oxidative stress and apoptosis were subsequently identified. Primary granulosa cells were isolated from mice, and the effects of H2O2 and MDL-800 on cell viability, oxidative stress, SIRT6 level, and apoptosis were evaluated. In addition, the regulation of SIRT6 on H3K9AC/p66SHC was verified by examining changes in protein levels, promoter activity, and the reversal effects of p66SHC overexpression.

RESULTS

MDL-800 mitigated hormone fluctuations, reduced follicle depletion in ovarian tissue, and attenuated oxidative stress and apoptosis in mice. In vitro experiments demonstrated that MDL-800 enhanced the resilience of primary granulosa cells against H2O2, as evidenced by increased cell viability and reduced oxidative stress and apoptosis. Furthermore, SIRT6 was found to decrease H3K9AC and p66SHC levels, as well as attenuate p66SHC promoter activity. The protective effects of MDL-800 on cells were reversed upon p66SHC overexpression.

CONCLUSION

In summary, this study highlights that activation of SIRT6 can alleviate POF and reduce oxidative stress by degrading H3K9AC and suppressing p66Shc levels in granulosa cells.

Integrated gut microbiota and fecal metabolome analyses of the effect of Lycium barbarum polysaccharide on D-galactose-induced premature ovarian insufficiency

Premature ovarian insufficiency (POI) has become one of the greatest health threats to the reproduction of women during their fertile age. Lycium barbarum polysaccharides (LBPs) are known for anti-aging and reproductive protective functions. Here, we investigated the protective effect of LBP on POI mice and revealed its possible mechanism by a combination of 16S rRNA sequencing and metabolomics analysis. In the current study, female C57BL/6J mice treated with D-galactose were used as a model to investigate the reversal effect of LBP on the degenerative ovarian function. The ameliorative effect of LBP on POI was evaluated from the estrous cycle, ovarian reserve, serum sex hormone levels, and fertility testing. Additionally, 16S rRNA gene sequencing and untargeted metabolomics were integrated to analyze the effects of LBP on the gut microbiota and fecal metabolic profile in the POI mice. The results showed that LBP administration significantly increased the total number of follicles and the number of follicles at different developmental stages in the POI mice. In addition, LBP was effective in reducing the serum levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), regularizing the disordered estrous cycle, and increasing the number of offspring of the POI mice. The results from 16S rRNA sequencing showed that LBP had beneficial effects on the composition and structure of the gut microbiota in the POI mice. In a metabolomics study, a total of 23 metabolites were finally identified as potential biomarkers of POI, and multiple pathways were regulated after the treatment of LBP, especially the arginine biosynthesis, glycerophospholipid metabolism and steroid hormone biosynthesis pathways. Pearson's correlation analysis showed that the regulation effect of LBP on metabolites was closely related to Faecalibaculum, Bilophila and Anaerofustis in the gut microbiota. In summary, the results demonstrated that LBP could improve the ovarian reserve and provides evidence both on the gut microbiota and metabolism, which provide beneficial support for the applications of LBP in female ovarian function degeneration.

Therapeutic effects of human umbilical cord mesenchymal stem cell-derived extracellular vesicles on ovarian functions through the PI3K/Akt cascade in mice with premature ovarian failure

Premature ovarian failure (POF) mainly refers to ovarian dysfunction in females younger than forty. Mesenchymal stem cells (MSCs) are considered an increasingly promising therapy for POF. This study intended to uncover the therapeutic effects of human umbilical cord MSC-derived extracellular vesicles (hucMSCEVs) on POF. hucMSCs were identified by observing morphology and examining differentiation capabilities. EVs were extracted from hucMSCs and later identified utilizing nanoparticle tracking analysis, transmission electron microscopy, and Western blotting. POF mouse models were established by injecting D-galactose (Dgal). The estrous cycles were assessed through vaginal cytology, and serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-mullerian hormone (AMH), estradiol (E2), and progesterone (P) were measured by ELISA. The human ovarian granulosa cell line KGN was used for in vitro experiments. The uptake of hucMSC-EVs by KGN cells was detected. After D-gal treatment, cell proliferation and apoptosis were assessed via CCK-8 assay and flow cytometry. The PI3K/Akt pathway-related proteins were determined by Western blotting. Our results revealed that POF mice had prolonged estrous cycles, increased FSH and LH levels, and decreased AMH, E2, and P levels. Treatment with hucMSC-EVs partially counteracted the above changes. D-gal treatment reduced proliferation and raised apoptosis in KGN cells, while hucMSC-EV treatment annulled the changes. D-gal-treated cells exhibited downregulated p-PI3K/PI3K and p-Akt/Akt levels, while hucMSC-EVs activated the PI3K/Akt pathway. LY294002 suppressed the roles of hucMSC-EVs in promoting KGN cell proliferation and lowering apoptosis. Collectively, hucMSC-EVs facilitate proliferation and suppress apoptosis of ovarian granulosa cells by activating the PI3K/Akt pathway, thereby alleviating POF.

EETs alleviate alveolar epithelial cell senescence by inhibiting endoplasmic reticulum stress through the Trim25/Keap1/Nrf2 axis

Alveolar epithelial cell (AEC) senescence is a key driver of a variety of chronic lung diseases. It remains a challenge how to alleviate AEC senescence and mitigate disease progression. Our study identified a critical role of epoxyeicosatrienoic acids (EETs), downstream metabolites of arachidonic acid (ARA) by cytochrome p450 (CYP), in alleviating AEC senescence. In vitro, we found that 14,15-EET content was significantly decreased in senescent AECs. Exogenous EETs supplementation, overexpression of CYP2J2, or inhibition of EETs degrading enzyme soluble epoxide hydrolase (sEH) to increase EETs alleviated AECs' senescence. Mechanistically, 14,15-EET promoted the expression of Trim25 to ubiquitinate and degrade Keap1 and promoted Nrf2 to enter the nucleus to exert an anti-oxidant effect, thereby inhibiting endoplasmic reticulum stress (ERS) and alleviating AEC senescence. Furthermore, in D-galactose (D-gal)-induced premature aging mouse model, inhibiting the degradation of EETs by Trifluoromethoxyphenyl propionylpiperidin urea (TPPU, an inhibitor of sEH) significantly inhibited the protein expression of p16, p21, and γH2AX. Meanwhile, TPPU reduced the degree of age-related pulmonary fibrosis in mice. Our study has confirmed that EETs are novel anti-senescence substances for AECs, providing new targets for the treatment of chronic lung diseases.

Red Ginseng Improves D-galactose-Induced Premature Ovarian Failure in Mice Based on Network Pharmacology

In this study, we evaluated the ameliorative effect and molecular mechanism of red ginseng (Panax ginseng C.A. Meyer) extract (RGE) on D-galactose (D-gal)-induced premature ovarian failure (POF) using network pharmacology analysis. Ginsenosides are important active ingredients in ginseng, which also contains some sugar and amino acid derivatives. We aimed to determine the key proteins through which RGE regulates POF. In this work, we retrieved and screened for active ingredients in ginseng and the corresponding POF disease targets in multiple databases. A PPI network of genes was constructed in the STRING database and core targets were screened using topological analysis. Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were conducted in R software. Finally, molecular docking was conducted to validate the results. Female ICR mice were used to establish a POF mouse model for in vivo experiments. Serum levels of relevant estrogens were determined using ELISA and expression levels of relevant proteins in ovarian tissues were detected using immunofluorescence and western blot analysis. Network pharmacology analysis predicted that PI3K, Akt, Bax, Bcl-2, p16, and other proteins were highly correlated with POF and RGE. The results clearly showed that RGE could increase estradiol (E2) and lower follicle-stimulating hormone (FSH) levels in D-gal-fed mice. RGE restored the expression levels of related proteins by reducing Nrf2-mediated oxidative stress, PI3K/Akt-mediated apoptosis, and senescence signaling pathways. Overall, RGE has the potential to prevent and treat POF and is likely to be a promising natural protector of the ovaries.

Molecular cloning and functional characterization of peroxiredoxin 4 (prx 4) in freshwater crayfish, Procambarus clarkii

Peroxiredoxin (Prx), which is a newly discovered member of the antioxidant protein family, performs important biological functions in intracellular signal transduction. In the present study, a peroxiredoxin 4 gene was cloned from crayfish for the first time and named Pc-prx 4. According to the amino acid sequence signature, Pc-Prx 4 was identified as the typical 2-Cys Prx molecule, which possessed two conserved cysteines (Cys98 and Cys219). Time-course expression patterns post V. harveyi infection revealed that Pc-prx 4 was likely related to crayfish innate immune defense responses. In particular, the highest fold upregulation of the Pc-prx 4 mRNA transcript reached approximately 170 post V. harveyi infection in the crayfish hepatopancreas. The results of the mixed functional oxidase assay showed that rPc-Prx 4^△ could resist the damaging effect of reactive oxygen species generated from the thiol/Fe³⁺/O₂^- reaction system to some extent. In addition, the results of the RNAi assay revealed that the crayfish survival rate was obviously increased post injection of V. harveyi when Pc-prx 4 was knocked down. Further study revealed that both hemolymph melanization and PO activity were strengthened to different degrees in the RNAi assay. Therefore, we speculated that the increase in the crayfish survival rate was likely due to the increase in hemolymph melanization. The obviously reinforced hemolymph melanization was directly caused by the upregulation of hemolymph PO activity, which was induced by the knockdown of Pc-prx 4. However, further studies are still indispensable for illuminating the molecular mechanism of Pc-prx 4 in the crayfish innate immune defense system.

Cellular battle against endoplasmic reticulum stress and its adverse effect on health

The endoplasmic reticulum (ER) is a dynamic organelle and a reliable performer for precisely folded proteins. To maintain its function and integrity, arrays of sensory and quality control systems enhance protein folding fidelity and resolve the highest error-prone areas. Yet numerous internal and external factors disrupt its homeostasis and trigger ER stress responses. Cells try to reduce the number of misfolded proteins via the UPR mechanism, and ER-related garbage disposals systems like ER-associated degradation (ERAD), ER-lysosome-associated degradation (ERLAD), ER-Associated RNA Silencing (ERAS), extracellular chaperoning, and autophagy systems, which activates and increase the cell survival rate by degrading misfolded proteins, prevent the aggregated proteins and remove the dysfunctional organelles. Throughout life, organisms must confront environmental stress to survive and develop. Communication between the ER & other organelles, signaling events mediated by calcium, reactive oxygen species, and inflammation are linked to diverse stress signaling pathways and regulate cell survival or cell death mechanisms. Unresolved cellular damages can cross the threshold limit of their survival, resulting in cell death or driving for various diseases. The multifaceted ability of unfolded protein response facilitates the therapeutic target and a biomarker for various diseases, helping with early diagnosis and detecting the severity of diseases.

Erxian decoction alleviates cisplatin-induced premature ovarian failure in rats by reducing oxidation levels in ovarian granulosa cells

ETHNOPHARMACOLOGICAL RELEVANT

Erxian Decoction (EXD) has been used empirically for more than 70 years to treat premature ovarian failure (POF), but more research is needed to understand how it works.

AIM OF THE RESEARCH

The study aims to ascertain both in vivo and in vitro rewards of EXD.

MATERIALS AND METHODS

EXD is composed of Curculiginis Rhizoma, Epimedii Folium, Morindae Officinalis, Angelicae Sinensis, Anemarrhenae Rhizoma, and Phellodendri Chinensis Cortex. UPLC/MS analysis was used to investigate the components of EXD. Using a POF model created by administering cisplatin to rats intraperitoneally, the pharmacodynamic effects of EXD were investigated. Three dose groups of EXD were garaged into rats: high (15.6 g/kg), medium (7.8 g/kg), and low (3.9 g/kg). By using a vaginal smear, the impact of EXD on the rat estrous cycle was evaluated. An ELISA test was used to measure the anti-Mullerian hormone (AMH), estradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels in the serum of rats. By using HE stains, pathological alterations in the ovaries may be seen. MDA and SOD levels in ovarian samples were used to measure the degree of ovarian oxidation. TUNEL labeling of ovarian sections was used to find apoptosis levels. By using ATP, energy production was evaluated. The relative expression of proteins connected to aging and the RAGE pathway was assessed using Western blot. Then, using H₂O₂, a model of senescent human ovarian granulosa cells (KGN) was created in vitro. The impact of EXD and H₂O₂ on cellular senescence was discovered using-galactosidase staining. Cell apoptosis levels were found using PI/Hoechest33342. By using DCFH-DA, intracellular ROS was examined. MDA and SOD concentrations were used to measure the degree of cellular oxidation. RAGE-related mRNA and protein expression were evaluated using RT-qPCR and western blotting.

RESULTS

Using UPLC/MS analysis, 39 chemicals in EXD were found. Rats' estrous cycles were enhanced by EXD, which increased ovarian index and follicle count and reduced the proportion of atretic follicles in the rats. EXD reduced LH and FSH output while restoring AMH and E2 secretion. In ovarian tissues, EXD reduced the amount of apoptosis and MDA while raising SOD activity and ATP levels. The protein levels of p16, p21, p53, and Lamin A/C were among the senescence-related proteins that EXD lowered, along with the levels of RAGE, PI3K, BAX, and CASPASE 3. Anti-apoptotic protein BCL-2 was also raised in the RAGE pathway. Senescence, apoptosis, ROS, and MDA levels in the KGN cells were lowered in vitro by EXD. Additionally, EXD increased the anti-apoptotic potential by changing the expression of CAT, SOD2, and SIRT1. RAGE, BAX, BCL-2, CASPASE 3, and p38 expression levels were altered by EXD, enhancing its anti-apoptotic capability.

CONCLUSION

EXD boosted the ovary's antioxidant and anti-apoptotic capabilities while enhancing the estrous cycle and hormone output. These findings strongly suggested that EXD may contribute to the alleviation of POF and ovarian granulosa cells senescence.

Changes in key life-history traits and transcriptome regulations of marine rotifer Brachionus plicatilis in eliminating harmful algae Phaeocystis

Rotifers have great potential in controlling the harmful algae Phaeocystis blooms that frequently occur in coastal waters. To evaluate the effects of harmful algae on the key life-history traits of rotifer in eliminating Phaeocystis and reveal the underlying mechanism of these effects, we fed Brachionus plicatilis with Chlorella vulgaris and Phaeocystis globosa respectively, recorded the key life-history traits, and conducted transcriptomic analysis. Results showed that the rotifers feeding on P. globosa significantly decreased total offspring but obviously prolonged lifespan compared to those feeding on C. vulgaris, indicating that there was a trade-off between the reproduction and lifespan of rotifers feeding on algae with different nutrient contents. Nevertheless, rotifers can completely eliminate the population of P. globosa. The changes in the reproduction and lifespan of rotifers are highly correlated with algal key nutrition and the expression of some related genes. Transcriptomic analysis showed that the changes in the key life history traits of rotifers feeding on harmful algae are determined by regulating the expression of some key genes involved in the pathways of carbohydrate digestion and absorption, glycolysis, gluconeogenesis, unsaturated fatty acid biosynthesis, and environmental stress. Understanding the trade-off of the key life history traits of zooplankton in eliminating harmful algae from the underlying mechanism helps improve their application for controlling harmful algae.

The Activation of Reticulophagy by ER Stress through the ATF4-MAP1LC3A-CCPG1 Pathway in Ovarian Granulosa Cells Is Linked to Apoptosis and Necroptosis

Female infertility is caused by premature ovarian failure (POF), which is triggered by the endoplasmic reticulum (ER) stress-mediated apoptosis of granulosa cells. The ER unfolded protein response (UPR^er) is initiated to promote cell survival by alleviating excessive ER stress, but cellular apoptosis is induced by persistent or strong ER stress. Recent studies have reported that reticulophagy is initiated by ER stress. Whether reticulophagy is activated in the ER stress-mediated apoptosis of granulosa cells and which pathway is initiated to activate reticulophagy during the apoptosis of granulosa cells are unknown. Therefore, the role of reticulophagy in granulosa cell death and the relationship between ER stress and reticulophagy were investigated in this work. Our results suggest that the ER stress inducer tunicamycin causes POF in mice, which is attributed to the apoptosis of granulosa cells and is accompanied by the activation of UPR^er and reticulophagy. Furthermore, granulosa cells were treated with tunicamycin, and granulosa cell apoptosis was triggered and increased the expression of UPR^er and reticulophagy molecules. The expression of ATF4 was then downregulated by RNAi, which decreased the levels of autophagy and the reticulophagy receptor CCGP1. Furthermore, ATF4 targets MAP1LC3A, as revealed by the ChIP sequencing results, and co-IP results demonstrated that MAP1LC3A interacts with CCPG1. Therefore, reticulophagy was activated by ER stress through the ATF4-MAP1LC3A-CCPG1 pathway to mitigate ER stress. Additionally, the role of reticulophagy in granulosa cells was investigated by the knockdown of CCPG1 with RNAi. Interestingly, only a small number of granulosa cells died by apoptosis, whereas the death of most granulosa cells occurred by necroptosis triggered by STAT1 and STAT3 to impair ER proteostasis and the ER protein quality control system UPR^er. Taken together, the results indicate that the necroptosis of granulosa cells is triggered by up- and downregulating the reticulophagy receptor CCPG1 through STAT1/STAT3-(p)RIPK1-(p)RIPK3-(p)MLKL and that reticulophagy is activated by ER stress through the ATF4-MAP1LC3A-CCPG1 pathway.

D-galactose protects the intestine from ionizing radiation-induced injury by altering the gut microbiome

This article aims to investigate the protection of the intestine from ionizing radiation-induced injury by using D-galactose (D-gal) to alter the gut microbiome. In addition, this observation opens up further lines of research to further increase therapeutic potentials. Male C57BL/6 mice were exposed to 7.5 Gy of total body irradiation (TBI) or 13 Gy of total abdominal irradiation (TAI) in this study. After adjustment, D-gal was intraperitoneally injected into mice at a dose of 750 mg/kg/day. Survival rates, body weights, histological experiments and the level of the inflammatory factor IL-1β were observed after TBI to investigate radiation injury in mice. Feces were collected from mice for 16S high-throughput sequencing after TAI. Furthermore, fecal microorganism transplantation (FMT) was performed to confirm the effect of D-gal on radiation injury recovery. Intraperitoneally administered D-gal significantly increased the survival of irradiated mice by altering the gut microbiota structure. Furthermore, the fecal microbiota transplanted from D-gal-treated mice protected against radiation injury and improved the survival rate of recipient mice. Taken together, D-gal accelerates gut recovery following radiation injury by promoting the growth of specific microorganisms, especially those in the class Erysipelotrichia. The study discovered that D-gal-induced changes in the microbiota protect against radiation-induced intestinal injury. Erysipelotrichia and its metabolites are a promising therapeutic option for post-radiation intestinal regeneration.

VDR activation attenuates osteoblastic ferroptosis and senescence by stimulating the Nrf2/GPX4 pathway in age-related osteoporosis

Ferroptosis plays an essential role in the pathology of osteoporosis. This study investigated whether vitamin D receptor (VDR) activation could protect against age-related osteoporosis through an anti-ferroptosis mechanism. d-galactose (D-gal)-induced mice and VDR-knockout mice were used in the in-vivo study. The VDR activator (1,25(OH)₂D₃) attenuated senescence and ferroptosis in the D-gal-induced bone, as illustrated by downregulated senescence-associated secretory phenotype genes, improved mitochondrial morphology, elevated glutathione, and decreased lipid peroxidation markers (malondialdehyde and 4-hydroxynonenal). The pre-osteoblast MC3T3-E1 cells and primary rat osteoblasts were applied in the in-vitro studies. 1,25(OH)₂D₃ or ferroptosis inhibitor (ferrostatin-1) treatment downregulated the cellular senescence markers in D-gal-induced osteoblasts. Mechanistically, 1,25(OH)₂D₃ activated the VDR and its downstream nuclear factor erythroid 2-related factor 2 (Nrf2)/glutathione peroxidase 4 (GPX4) signaling pathway, resulting in the downregulation of lipid peroxidation. Nrf2 knockdown or addition of GPX4 inhibitor (RSL-3) blocked the protective effect of 1,25(OH)₂D₃ against D-gal-induced ferroptosis and senescence. VDR knockdown impeded the 1,25(OH)₂D₃-induced activation of Nrf2/GPX4 pathway in osteoblasts. Proteomics and immunofluorescence analysis confirmed that ferroptosis and suppression of the Nrf2/GPX4 pathway occurred in VDR-knockout mice. Our data demonstrated that ferroptosis played an essential role in age-related osteoporosis. The VDR activation attenuated osteoblast ferroptosis via stimulating the Nrf2/GPX4 signaling pathway.

ER stress in cardiac aging, a current view on the D-galactose model

Longitudinal studies are mandatory to study aging, however, they have certain drawbacks, for example, they require strict maintenance that is expensive given the breeding time (approximately 2 years) and with a low survival rate, having some animals to study very limitedly. In vitro studies provide useful and invaluable information on the cellular and molecular mechanisms that help understand the aging process to overcome these aspects. In particular, the model of premature aging induced by chronic exposure to D-galactose (D-Gal) offers a very similar picture to that which occurs in natural aging. This model mimics most of the old animals' cellular processes, such as oxidative stress, mitochondrial dysfunction, increased advanced glycation end products (AGEs), inflammation, and senescence-associated secretory phenotype (SASP). However, the information related to the endoplasmic reticulum (ER) stress and, subsequently, the unfolded protein response (UPR) is not fully elucidated. Therefore, this review brings together the most current information on this response in the D-Gal-induced aging model and its effect on cardiac structure and function.

Follicle-Stimulating Hormone Alleviates Ovarian Aging by Modulating Mitophagy- and Glycophagy-Based Energy Metabolism in Hens

As a predominant hormone in the reproductive axis, follicle-stimulating hormone (FSH) is known as the primary surviving factor for follicular growth. In this study, the alleviating effect of FSH on aging chicken granulosa cells (GCs) was investigated. Results showed that FSH activated mitophagy and relieved mitochondrial edema in D-gal-induced senescent GCs, which was evidenced by an increased number of mitophagosomes as well as increased mitochondria-light chain 3 (LC3) colocalization. Mitophagy activation was accompanied by the activation of the AMP-activated protein kinase (AMPK) signaling pathway. Furthermore, upregulated glycophagy was demonstrated by an increased interaction of starch-binding domain protein 1 (STBD1) with GABA type A receptor-associated protein-like 1 (GABARAPL1) in D-gal-induced senescent GCs. FSH treatment further promoted glycophagy, accompanied by PI3K/AKT activation. PI3K inhibitor LY294002 and AKT inhibitor GSK690693 attenuated the effect of FSH on glycophagy and glycolysis. The inhibition of FSH-mediated autophagy attenuated the protective effect of FSH on naturally aging GC proliferation and glycolysis. The simultaneous blockage of PI3K/AKT and AMPK signaling also abolished the positive effect of FSH on naturally senescent ovarian energy regulation. These data reveal that FSH prevents chicken ovarian aging by modulating glycophagy- and mitophagy-based energy metabolism through the PI3K/AKT and AMPK pathways.

Role of Reactive Oxygen Species in Aging and Age-Related Diseases: A Review

Research on the role of reactive oxygen species (ROS) in the aging process has advanced significantly over the last two decades. In light of recent findings, ROS takes part in the aging process of cells along with contributing to various physiological signaling pathways. Antioxidants being cells' natural defense mechanism against ROS-mediated alteration, play an imperative role to maintain intracellular ROS homeostasis. Although the complete understanding of the ROS regulated aging process is yet to be fully comprehended, current insights into various sources of cellular ROS and their correlation with the aging process and age-related diseases are portrayed in this review. In addition, results on the effect of antioxidants on ROS homeostasis and the aging process as well as their advances in clinical trials are also discussed in detail. The future perspective in ROS-antioxidant dynamics on antiaging research is also marshaled to provide future directions for ROS-mediated antiaging research fields.

Curcumin Inhibits Hyperandrogen-Induced IRE1α-XBP1 Pathway Activation by Activating the PI3K/AKT Signaling in Ovarian Granulosa Cells of PCOS Model Rats

Background

Hyperandrogenism is a common characteristic of polycystic ovary syndrome (PCOS). Long-term, continuous exposure to hyperandrogenic environments may cause excessive endoplasmic reticulum (ER) stress in ovarian granulosa cells (GCs). Curcumin is a polyphenol extracted from turmeric rhizomes which has several pharmacological effects that may benefit patients with PCOS. To explore whether curcumin can inhibit hyperandrogen-induced ER stress in ovarian GCs of PCOS rats and to elucidate the possible underlying mechanisms.

Methods

We developed PCOS model rats by exposure to hyperandrogenic conditions and divided the rats into control, PCOS, and PCOS+curcumin (200 mg/kg, for 8 weeks) groups. The levels of ER stress-related proteins and PI3K/AKT phosphorylation were measured in the ovarian tissue of all experimental groups by real-time quantitative PCR, western blotting, immunohistochemistry, and immunofluorescence. Subsequent in vitro analysis on primary cultured GCs was performed to confirm the influence of curcumin on ER stress inhibition by immunofluorescence and western blotting.

Results

Curcumin protects GCs from hyperandrogen-induced apoptosis in PCOS model rats by inhibiting the ER stress-related IRE1α-XBP1 pathway and activating the PI3K/AKT signaling pathway.

Conclusions

These observations indicate that curcumin might be a safe and useful supplement for PCOS patients.

Metabolomics and biochemical insights on the regulation of aging-related diabetes by a low-molecular-weight polysaccharide from green microalga Chlorella pyrenoidosa

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C. pyrenoidosa polysaccharide (CPP) have hypoglycemic activity and oxidation resistance.

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CPP prevents oxidative stress and stimulates insulin via affecting phenylpyruvic acid.

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CPP can regulate the GLP-1R/IL-6R and ZO-1/MMP-2 pathways.

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CPP activated BCL-6 to promote cell survival in brain.

Globally, aging and diabetes are considered prevalent threats to human health. Chlorella pyrenoidosa polysaccharide (CPP) is a natural active ingredient with multiple health benefits including antioxidant and hypolipidemic activities. In this study, the aging-related diabetic (AD) mice model was established to investigate the underlying hypoglycemic and antioxidant mechanisms of CPP. It improved superoxide dismutase, catalase (CAT), glutathione peroxidase (GSH-px), and malondialdehyde activities in liver and insulin secretion. CAT and GSH-px activity in the brain increased after CPP administration. In addition, through histopathological examinations, it was evident that injuries in the liver, brain, jejunum, and pancreas were restored by CPP. This restoration was likely mediated via the activation of glucagon-like peptide-1 receptor/FOXO-1 (forkhead box O1) pathway concurrent with the inhibition of interleukin-6 receptor/FOXO-1 pathway. Furthermore, metabolomics and correlation analysis revealed that CPP possibly relived AD through changes in insulin levels and declined oxidative stress as regulated by phenylpyruvic acid. These findings suggested that CPP exerted antioxidant and hypoglycemic roles in an AD mice model, thereby providing a sound scientific foundation for further development and utilization of CPP.

Peroxiredoxin, Senescence, and Cancer

Peroxiredoxins are multifunctional enzymes that play a key role in protecting cells from stresses and maintaining the homeostasis of many cellular processes. Peroxiredoxins were firstly identified as antioxidant enzymes that can be found in all living organisms. Later studies demonstrated that peroxiredoxins also act as redox signaling regulators, chaperones, and proinflammatory factors and play important roles in oxidative defense, redox signaling, protein folding, cycle cell progression, DNA integrity, inflammation, and carcinogenesis. The versatility of peroxiredoxins is mainly based on their unique active center cysteine with a wide range of redox states and the ability to switch between low- and high-molecular-weight species for regulating their peroxidase and chaperone activities. Understanding the molecular mechanisms of peroxiredoxin in these processes will allow the development of new approaches to enhance longevity and to treat various cancers. In this article, we briefly review the history of peroxiredoxins, summarize recent advances in our understanding of peroxiredoxins in aging- and cancer-related biological processes, and discuss the future perspectives of using peroxiredoxins in disease diagnostics and treatments.