Spermatogenesis dysfunction induced by PM2.5 from automobile exhaust via the ROS-mediated MAPK signaling pathway.

Long-term exposure to particulate matter 2.5 (PM2.5) from automobile exhaust impairs spermatogenesis through oxidative stress injury, but the underlying mechanism is unknown. To investigate the toxic mechanism of PM2.5-induced spermatogenesis impairment, we focused on the MAPK signaling pathway. We also examined the effects of treatment with vitamins C and E on spermatogenic function. Male SD rats were divided randomly into three groups: control (0.9% sterilized saline), PM2.5 exposure (20 mg/kg.b.w.), and PM2.5 exposure (20 mg/kg.b.w.) with vitamin intervention (vitamin C, 100 mg/kg.b.w.; vitamin E, 50 mg/kg.b.w.). Male rats showed a marked decline in fertility and decreased sperm quality after PM2.5 exposure. The expression of SOD and Nrf2 was significantly decreased, and that of MDA was increased markedly. The expression of blood-testis barrier-associated proteins, such as ZO-1, occludin, connexin 43, and ß-catenin, was significantly decreased, the Bcl-2/Bax ratio was downregulated, and the cleaved caspase-3 level was increased. Phosphorylation of MAPKs, including ERKs, JNKs, and p38, was upregulated. Treatment with vitamins C and E reversed the damage induced by PM2.5 exposure. These results suggest that PM2.5 from automobile exhaust disrupted spermatogenesis via ROS-mediated MAPK pathways, and that a combined vitamin C and E intervention effectively mitigated toxicity in the male reproductive system.

Urban fine particulate matter (PM2.5) exposure destroys blood-testis barrier (BTB) integrity through excessive ROS-mediated autophagy.

CONTEXT: Blood-testis barrier (BTB), constituted by tight junctions (TJs), adherens junctions and gap junctions, is important for spermatogenesis. PM2.5 is known to impair testicular functions and reproduction. However, its effects on BTB and the underlying mechanisms remain obscure. OBJECTIVE: To investigate the roles of autophagy in BTB toxicity induced by PM2.5. MATERIALS AND METHODS: Sprague-Dawley rats were developmentally exposed to normal saline (NS) or PM2.5 with the doses of 9 mg/kg b.w. and 24 mg/kg b.w. via intratracheal instillation for seven weeks. Success rate of mating, sperm quality, testicular morphology, expressions of BTB junction proteins and autophagy-related proteins were detected. In addition, expressions of oxidative stress markers were also analyzed. RESULTS: Our results demonstrated that developmental PM2.5 exposure induced noticeable decreased fertility, significantly reduced sperm count, increased sperm abnormality rate and severe testicular damage in histomorphology. The expressions of TJ (such as ZO-1 and occludin), gap junction (such as connexin43) were down-regulated significantly after PM2.5 treatment. Intriguingly, PM2.5 simultaneously increased the number of autophagosomes and the levels of autophagy marker LC3-II and p62, suggesting that the accumulated autophagosomes resulted from impaired autophagy degradation. Moreover, the expressions of HO-1 levels remarkably increased and expression levels of Gpx and SOD were significantly decreased after PM2.5 exposure. Vitamins E and C could alleviate the PM2.5-induced oxidative stress, reverse the autophagy defect and restore the BTB impairment. CONCLUSIONS: Taken together, the results suggest that PM2.5 exposure destroys BTB integrity through excessive ROS-mediated autophagy. Our finding could contribute to a better understanding of PM2.5-induced male reproductive toxicity.

Testicular developmental impairment caused by flutamide-induced and DEHP-induced cryptorchid rat models is mediated by excessive apoptosis and deficient autophagy.

BACKGROUND: Cryptorchidism is a common condition of childhood, and it is known to impair fertility potential. However, the underlying mechanisms remain unclear. METHODS: This study constructed two cryptorchid rat models to investigate the roles of apoptosis and autophagy in testicular impairment induced by cryptorchidism. Pregnant rats were randomly divided into three groups. Group I: non-treated rats were used as controls. Group II: injected with drug Flutamide (Flu) 25 mg/kg/bw/d from gestation day (GD) 11-19. Group III: daily intragastric administration of 750 mg/kg/bw/d di-2-ethylhexylphosphate (DEHP) from GD 7-19. The cubs were feed normally and the testes were excised on postnatal day (PND) 30. RESULTS: Our results demonstrated cryptorchidism models induced noticeable decreased fertility, significantly reduced sperm count, increased sperm abnormality rate, decreased testosterone and severe testicular damage in histomorphology. Intriguingly, the level of apoptosis marker FAS, Cytochrome C and caspase-3 increased in Flu-induced and DEHP-induced groups. DEHP-induced treatment simultaneously increased the number of autophagosomes and the levels of autophagy marker LC3-II and p62. Significant decrease of autophagy gene (LC3-II and p62) expression is found in Flu-induced rats testes. CONCLUSION: Taken together, deficient autophagy is involved in testicular spermatogenesis damage of cryptorchidism rats. And this autophagy defect is caused by deficient degradation.

Cell therapy in patients with heart failure: a comprehensive review and emerging concepts.

This review summarizes the results of clinical trials of cell therapy in patients with heart failure (HF). In contrast to acute myocardial infarction (where results have been consistently negative for more than a decade), in the setting of HF the results of Phase I-II trials are encouraging, both in ischaemic and non-ischaemic cardiomyopathy. Several well-designed Phase II studies have met their primary endpoint and demonstrated an efficacy signal, which is remarkable considering that only one dose of cells was used. That an efficacy signal was seen 6-12 months after a single treatment provides a rationale for larger, rigorous trials. Importantly, no safety concerns have emerged. Amongst the various cell types tested, mesenchymal stromal cells derived from bone marrow (BM), umbilical cord, or adipose tissue show the greatest promise. In contrast, embryonic stem cells are not likely to become a clinical therapy. Unfractionated BM cells and cardiosphere-derived cells have been abandoned. The cell products used for HF will most likely be allogeneic. New approaches, such as repeated cell treatment and intravenous delivery, may revolutionize the field. As is the case for most new therapies, the development of cell therapies for HF has been slow, plagued by multifarious problems, and punctuated by many setbacks; at present, the utility of cell therapy in HF remains to be determined. What the field needs is rigorous, well-designed Phase III trials. The most important things to move forward are to keep an open mind, avoid preconceived notions, and let ourselves be guided by the evidence.

Clinical and socioeconomic factors associated with delayed orchidopexy in cryptorchid boys in China: a retrospective study of 2423 cases.

We investigated the associations of clinical and socioeconomic factors with delayed orchidopexy for cryptorchidism in China. A retrospective study was conducted on cryptorchid boys who underwent orchidopexy at Children's Hospital at Chongqing Medical University in China from January 2012 to December 2017. Of 2423 patients, 410 (16.9%) received timely repair by 18 months of age, beyond which surgery was considered delayed. Univariate analysis suggested that the laterality of cryptorchidism (P = 0.001), comorbidities including inguinal hernia/scrotal hydrocele (P < 0.001) or urinary tract disease (P = 0.016), and whether patients lived in a poverty county (P < 0.001) could influence whether orchidopexy was timely or delayed. Logistic regression analysis suggested that the following factors were associated with delayed repair: unilateral rather than bilateral cryptorchidism (odds ratio [OR] = 1.752, P < 0.001), absence of inguinal hernia or hydrocele (OR = 2.027, P = 0.019), absence of urinary tract disease (OR = 3.712, P < 0.001), and living in a poverty county (OR = 2.005, P < 0.001). The duration of postoperative hospital stay and hospital costs increased with the patient's age at the time of surgery.

[Effect of Di-(2-ethylhcxyl) phthalate exposure on blood-testis barrier integrity in rats].

OBJECTIVE: To investigate mechanism of di-(2-ethylhcxyl)phthalate (DEHP) exposure in causing blood-testis barrier (BTB) impairment in rats. METHODS: Two-months-old male SD rats were randomly divided into corn oil control group and DEHP (750 mg/kg) exposure group for daily intragastic treatment for 30 consecutive days. After the treatments the rats were examined for histomorphological changes of the testicle using HE staining and the expressions of the junction proteins N-cadherin ß-catenin, occludin and connexin43 of the BTB using Western blot. In the in vitro study, the vitality and ROS generation level in Sertoli cells exposed to different concentrations of DEHP were examined with MTT and ROS assay kits, respectively, and Nrf2 and p-p38 expressions were detected with Western blot. RESULTS: Compared with the control group, the rats with DEHP exposure showed structural damage of the seminiferous tubule and polarity loss of the spermatids. DEHP exposure caused significantly decreased expressions of occludin and connexin43 but increased expressions of N-cadherin and ß-catenin in the testicle tissues of the rats (P<0.05). The vitality of Sertoli cells was obviously decreased and ROS level increased significantly after exposure of the cells to increasing concentrations of DEHP, which also resulted in significantly up-regulated Nrf2 and p-p38 expressions (P<0.05). CONCLUSIONS: DEHP exposure causes increased oxidative stress in the Sertoli cells of the testis, activates p38 MAPK signaling pathway, and results eventually in impaired spermatogenesis in rats.

Urban fine particulate matter exposure causes male reproductive injury through destroying blood-testis barrier (BTB) integrity.

Blood-testis barrier (BTB) provides a suitable microenvironment for germ cells that is required for spermatogenesis. Exposure to particulate matter (PM) is recognized to occasion male reproductive impairment, but the mechanism of which remains unclear. Male Sprague-Dawley (SD) rats were used to establish animal models with PM2.5 exposure concentration of 0, 10, and 20mg/kg.b.w. once a day for four weeks. Success rate of mating, sperm quality, epididymal morphology, expressions of spermatogenesis markers, superoxide dismutases (SOD) activity and expression in testicular tissues, and expressions of BTB junction proteins were detected. In addition, in vitro experiments were also performed. After PM2.5 treatment, reactive oxygen species (ROS) production and apoptosis of Sertoli cells were analyzed. Our results indicated that after PM2.5 exposure male rats presented inferior uberty and sperm quality, with decreased expressions of spermatogenesis markers, escalated SOD activity and expression levels, and reduced expressions of tight junction, adherens junction, and gap junction proteins in testicular tissues. Meantime, PM2.5-treated Sertoli cells displayed increased SOD production and apoptosis. PM2.5 exposure engenders male reproductive function injury through breaking BTB integrity.