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There is evidence of an association between exposure to ambient fine particulate matter (PM2.5) and female ovarian dysfunction in adults. However, it is not fully clear whether maternal exposure to PM2.5 negatively affects the ovarian function in offspring. The size of primordial follicle pool, definitely assembled during fetal life, determines ovarian reserve and ovarian function. In this study, female C57BL/6 mice were exposed to either ambient PM2.5 (mean daily concentration 49 µg/m3) or filtered air through a whole-body exposure system for 4 weeks before mating, and remained exposed until postpartum. We found that maternal exposure to PM2.5 reduces the initial size of primordial follicle pool and impairs its development in offspring mice. The number of primordial follicles and total follicles was decreased in PM2.5-exposed offspring mice on postnatal day 3 (PND3) and postnatal day 7 (PND7). Maternal PM2.5 exposure promoted the activation of primordial follicles and upregulated the level of p-AKT in offspring mice, accelerating the depletion of primordial follicle pool. While LY294002, a specific inhibitor of PI3K, reversed the overactivation of primordial follicles induced by PM2.5. Besides, maternal PM2.5 exposure induced follicular atresia and granulosa cell apoptosis, increased the accumulation of lipid peroxidation products 4-HNE, and elevated the expression of oxidative stress-related genes and p-p65, p-IκBα in offspring mice. While N-acetylcysteine (NAC) pretreatment abolished the increases of apoptosis, reactive oxygen species (ROS), p-p65 and p-IκBα levels in ovarian granulosa COV434 cells induced by PM2.5 exposure. These findings reveal that maternal exposure to PM2.5 decreases the initial size of primordial follicle pool, and impairs ovarian follicular development in offspring mice. Our data suggest that this involves the activation of the PI3K/AKT/FoxO3a pathway and the ROS-dependent NF-κB pathway. Our study implicates a link between maternal PM2.5 exposure and ovarian reserve in offspring, and improves our understanding of the effects of PM2.5 on reproductive health. [Display omitted] • Maternal PM2.5 exposure reduces ovarian reserve. • Maternal PM2.5 exposure accelerates primordial follicle activation through the PI3K/AKT/FoxO3a pathway. • Maternal PM2.5 exposure induces follicular atresia through ROS-dependent NF-κB pathway. [ABSTRACT FROM AUTHOR]

Objective To investigate the effects of tanshinone II A ( Tan II A) on the intermittent high glucose (IHG)- induced oxidative stress and apoptosis of Schwann cells (SCs) in suckling rat. Methods Cultured SCs of newborn suckling rats were randomized into several groups including control (con, 5.6 mmol/L glucose), stable high glucose (HG, 50 mmol/L glucose), IHG (5.6 and 50.0 mmol/L glucoseper 8 h alternative), osmotic control, ALA (500 µmol/L) and IHG in the presence of 0.1, 1.0, 10.0 µmol/L Tan II A. Apoptosis rate, oxidative stress level, expression of apoptosis related proteins and the mRNA in the cells were detected. Results (1) The percentages of apoptotic cells exposed to HG ((34.57± 2.45)%) and IHG ((40.17±2.33)%) were significantly higher than that in control group ((4.74±0.26)%). Furthermore, apoptosis rate of IHG was much higher than that of HG (t=3.70,P<0.01). (2) ROS and 8-OHdG levels increased significantly in the IHG group compared with those in control and HG groups (F=73.44, 194.21, P<0.01). IHG exposure up-regulated expression of bax protein and mRNA (F=66.78, 126.69, both P<0.01), while down-regulating expression of bcl-2 protein and mRNA (F=151.88,54.99,both P<0.01). In addition, IHG increased activities of caspase-3 and (poly(ADP-ribose) polymerase, PARP) (129% ,18% , 139% ,56% ,all P<0.01). (3) Treatment with 1.0 µmol/L and 10.0 µmol/L of Tan IIA inhibited IHG-enhanced ROS production and 8-OHdG levels (t=3.50-6.47,P<0.05). Bax protein and mRNA (t=3.59-5.39,P<0.01), PARP and caspase-3 activation (42%,61%,13%,34%,all P<0.01), and SC apoptosis (t= 12.39, 21.26, P<0.01)were decreased with Tan µ A, too. Conclusions Tan µ A decreases IHG-induced apoptosis via reducing oxidative stressin SCs of newborn suckling rats. [ABSTRACT FROM AUTHOR]

Our previous study demonstrated that ovarian wild-type P53-induced phosphatase 1 (WIP1) expression decreased with age. We hypothesized that WIP1 activity was related to ovarian aging. The role of WIP1 in regulating ovarian aging and its mechanisms remain to be elucidated. Adult female mice with or without WIP1 inhibitor (GSK2830371) treatment were divided into three groups (Veh, GSK-7.5, GSK-15) to evaluate the effect of WIP1 on ovarian endocrine and reproductive function and the ovarian reserve. In vitro follicle culture and primary granulosa cell culture were applied to explore the mechanisms of WIP1 in regulating follicular development. This study revealed that WIP1 expression in atretic follicle granulosa cells is significantly lower than that in healthy follicles. Inhibiting WIP1 phosphatase activity in mice induced irregular estrous cycles, caused fertility declines, and decreased the ovarian reserve through triggering excessive follicular atresia and primordial follicle activation. Primordial follicle depletion was accelerated via PI3K-AKT-rpS6 signaling pathway activation. In vitro follicle culture experiments revealed that inhibiting WIP1 activity impaired follicular development and oocyte quality. In vitro granulosa cell experiments further indicated that downregulating WIP1 expression promoted granulosa cell death via WIP1-p53-BAX signaling pathway-mediated apoptosis. These findings suggest that appropriate WIP1 expression is essential for healthy follicular development, and decreased WIP1 expression accelerates ovarian aging by promoting follicular atresia and primordial follicle activation. [ABSTRACT FROM AUTHOR]

What role does wild-type p53-induced phosphatase 1 (WIP1) play in the regulation of primordial follicle development? WIP1 expression was detected in the ovaries of mice of different ages by western blotting and immunohistochemical staining. Three-day-old neonatal mouse ovaries were cultured in vitro with or without the WIP1 inhibitor GSK2830371 (10 μM) for 4 days. Ovarian morphology, follicle growth and follicle classification were analysed and the PI3K–AKT–mTOR signal pathway and the WIP1–p53-related mitochondrial apoptosis pathway evaluated. WIP1 expression was downregulated with age. Primordial follicles were significantly decreased in the GSK2830371-treated group, without a significant increase in growing follicles. The ratio of growing follicles to primordial follicles was not significantly different between the control and GSK2830371 groups, and no significant variation was observed in the PI3K–AKT–mTOR signal pathway. The inhibition of WIP1 phosphatase accelerated primordial follicle atresia by activating the p53–BAX–caspase-3 pathway. These findings reveal that WIP1 participates in regulating primordial follicle development and that inhibiting WIP1 phosphatase leads to massive primordial follicle loss via interaction with the p53–BAX–caspase-3 pathway. This might also provide valuable information for understanding decreased ovarian reserve during ovarian ageing. [ABSTRACT FROM AUTHOR]

Abstract Learning disabilities (LDs) in children are a serious global problem. Dibutyl phthalate (DBP), a plasticizer widely used in daily life, has been linked to triggering childhood LDs, however the mechanism underlying this remains unclear. Studies have shown that the ERK 1/2 pathway is closely related to apoptosis of hippocampal neurons. On the basis of these links between LDs, DBP and the ERK 1/2 pathway, we explore whether DBP induces hippocampal neuron apoptosis and increases behavioral disorders in mice via the ERK 1/2 pathway. We looked at oxidative stress, examined the calcium signal, detected the ERK 1/2 pathway and evaluated apoptosis as well as using histological observations, and found that DBP significantly increased oxidative damage and apoptosis in hippocampal neurons via the ERK 1/2 pathway in mice. We also found that pretreatment with the dihydropyridine's (DHP's) Ca2+ antagonist, nimodipine (NMDP), combined with the antioxidant Vitamin E (VE), attenuated ERK 1/2 phosphorylation and DBP-mediated disorders, suggesting that a combined use of VE and NMDP can ameliorate DBP-induced memory deficit and apoptosis via inhibiting the ERK 1/2 pathway. These results indicate that DBP predisposes oxidative damage and apoptosis in hippocampal neurons by activation of the ERK 1/2 pathway, and may be proposed as a possible mechanism underlying LDs in children. Moreover, VE and NMDP may play a certain protective role in the targeted treatment of childhood LDs. Graphical abstract Unlabelled Image Highlights • DBP induces apoptosis of hippocampal neurons via the ERK 1/2 pathway. • DBP activates the ERK 1/2 pathway through ROS accumulation and excessive Ca2+. • VE and NMDP can ameliorate DBP-induced apoptosis by inhibiting the ERK 1/2 pathway. [ABSTRACT FROM AUTHOR]

Spinal cord injury (SCI) leads to irreversible neuronal loss and ultimately leads to paralysis. Bone marrow derived mesenchymal stem cells (BMSCs) have been demonstrated to be an effective approach to treat SCI. The present study was designed to investigate the role of BMSCs in rats with spinal cord injury and in oxygen-glucose deprivation (OGD) treated motor neurons. The results demonstrated that BMSCs could improve locomotor function and decrease expression of pro-apoptotic transcription factor C/EBP homologous protein (CHOP) and apoptosis after SCI. Furthermore, co-culture with BMSCs or conditioned medium from BMSCs could also decrease the expression of CHOP and apoptosis in post-OGD motor neurons, supporting that BMSCs exerts protective effects by decreasing the expression of CHOP in injured motor neurons. Our findings provide a potential novel mechanism for BMSCs treatments in patients with SCI. [ABSTRACT FROM AUTHOR]

Bone marrow mesenchymal stem cells (BMSCs) therapy for tissue repair is limited by low survival of cells transplanted in the recipient sites after spinal cord injury (SCI). Here, we investigated the effects of a calpain inhibitor (MDL28170) on BMSCs survival by a rat model of spinal cord injury in vitro and in vivo. Conditioned medium from hypoxia injured VSC4.1 motor neurons (Hypoxia-CM) were collected to mimic the micro-environment of injured spinal cord. Tunicamycin was also applied to induce endoplasmic reticulum (ER) stress in BMSCs. The CCK-8 assay, LDH leakage assay and flow cytometer assay demonstrated that MDL28170 could enhance BMSCs survival in response to Hypoxia-CM and tunicamycin. Moreover, MDL28170 significantly enhanced GFP-positive BMSCs survival in vivo after transplantation into the contused spinal cord of SCI rats. The protective effects of MDL28170 on BMSCs survival may inhibit the activation of calpain and the downstream ER stress-induced apoptosis. The present results suggested for the first time that MDL28170 with BMSCs transplant helped to rescue cells in injured spinal cord by modulating the ER stress-induced apoptosis. The calpain inhibitor, MDL28170 may have the promising new strategies for promoting the survival of transplanted BMSCs on cell-based regenerative medicine. [ABSTRACT FROM AUTHOR]

• SIRT3 can enhance the sensitivity of small cell lung cancer cells to cisplatin. • SIRT3 deacetylate mutant p53, reduce its expression by the ubiquitin proteasome pathway. • The relationship between SIRT3 and mutant p53 maybe a new SCLC treatment approach. Small-cell lung cancer (SCLC) is the most invasive of all lung cancer subtypes, and is characterized by its rapid response to chemotherapy resistance. Overcoming chemotherapy resistance is therefore the key to treating SCLC. P53 is mutated in most SCLCs, which has an effect of enhancing chemotherapy resistance. Regulation of p53 proteins by a variety of post-translational modifications, such as acetylation, which affects their function. Acetylation and deacetylation of p53 may be potential targets for modulating chemosensitivity. Recent studies have shown that SIRT3 acts as a deacetylase that regulates acetylation of p53. However, whether SIRT3 can regulate the post-translational modification of mutant p53 has not been studied. In the present study, we found that SIRT3 can deacetylate mutant p53, thus reducing its expression, inducing apoptosis in SCLC cells, and increasing SCLC chemosensitivity. The relationship between SIRT3 and mutant p53 could be the basis of a new SCLC treatment approach. [ABSTRACT FROM AUTHOR]

Myelodysplastic syndromes (MDS) represent a family of hematopoietic stem cell disorders characterized by ineffective hematopoiesis. While the functions of many microRNAs have been identified in MDS, microRNA-144 (miR-144) remains poorly understood. Thus, the aim of the present study was to determine the effects of miR-144 on cell proliferation and apoptosis in MDS cells and mechanism thereof. MDS-related microarrays were used for screening differentially expressed genes in MDS. The relationship between miR-144 and A-kinase anchoring protein 12 (AKAP12) was determined by a dual luciferase reporter gene assay. Subsequently, gain- and loss-function approaches were used to assess the effects of miR-144 and AKAP12 on cell proliferation, cell cycle and cell apoptosis by MTT assay and flow cytometry. Following the induction of a mouse model with MDS, the tumor tissues were extract for evaluation of apoptosis and the expression of miR-144, AKAP12, and the relevant genes associated with extracellular-regulated protein kinases 1/2 (ERK1/2) signaling pathway and apoptosis. We observed significantly diminished expression of AKAP12 in MDS samples. miR-144 directly bound to AKAP12 3′UTR and reduced its expression in hematopoietic cells. Downregulation of miR-144 or upregulation of AKAP12 was observed to prolong cell cycle, inhibit cell proliferation, and induce apoptosis, accompanied by increased expression of AKAP12, p-ERK1/2, caspase-3, caspase-9, Bax, and p53, as well as decreased expression of Bcl-2. The transplanted tumors in mice with down-regulated miR-144 exhibited a lower mean tumor diameter and weight, and increased apoptosis index and expression of AKAP12 and ERK1/2. Taken together, these studies demonstrate the stimulative role of miR-144 in MDS progression by regulating AKAP12-dependent ERK1/2 signaling pathway. • This is a report that miR-144 regulates AKAP12-mediated ERK1/2 signaling pathway. • MiR-144 is highly expressed in MDS cells while AKAP12 is lowly expressed. • MiR-144 promotes MDS by inhibiting expression of AKAP12, a target gene of miR-144. • Down-regulation of miR-144 can activate the ERK1/2 axis and treat MDS. • This study provides a basis for proliferation and apoptosis in MDS cells. [ABSTRACT FROM AUTHOR]