Seasonal trends in the prevalence of hypospadias: Aetiological implications

Dysregulation of mitochondrial sirtuin genes is associated with human male infertility

Mitochondrial sirtuins (SIRT3, SIRT4, SIRT5) are post-translational modifiers that regulate energy production, body homeostasis and mitochondrial activities via different substrates in response to environmental stressors. The present study aimed at assessing the expression of SIRT3, SIRT4, and SIRT5 in the semen of infertile men. Expression analysis was performed using q-RT PCR. All mitochondrial sirtuin genes were significantly down-regulated in the semen of infertile men compared to fertile men. Mitochondrial sirtuin genes expression levels were correlated with mitochondrial HSP90 expression. HSP90 expression was positively correlated with SIRT3, SIRT4 and SIRT5 expression in the semen of fertile men, while a negative correlation was observed between HSP90 in the semen of infertile men and mitochondrial sirtuin genes in the semen of fertile men. These data suggest that dysregulation of mitochondrial sirtuin genes causes mitochondrial dysfunction due to stress, which appears to be associated with human male infertility by compromising functional and structural sperm integrity.

Di-2-ethylhexyl phthalate induces heart looping disorders during zebrafish development

Di-2-ethylhexyl phthalate (DEHP) is a type of plasticizer widely used in industry. It is well-known for its toxic effects to endocrine and reproductive systems and has been detected in amniotic fluid and placenta. In the present study, we explored the effects of DEHP on heart development by using zebrafish as a model organism. DEHP (0.02 pg) was injected into the yolk sac of zebrafish embryos at the one-cell stage. No significant difference was found in embryonic lethality between control and DEHP groups at 1-day postfertilization (dpf), but mortality significantly increased in DEHP groups at 2 and 3 dpf. The average heart rate was significantly reduced in the surviving DEHP-treated zebrafish larvae at 3 and 4 dpf. In addition, massive pericardial edema was found in DEHP-treated zebrafish (12.6 ± 1.5%), which was significantly higher than that of the control group. Serious heart looping disorder was also observed in DEHP-treated larvae, mainly manifested with an elongated atrial-ventricular distance. Moreover, the expression of heart development transcription factors was affected by DEHP injection. Real-time polymerase chain reaction confirmed that five transcription factors (hand2, tp53, mef2c, esr1, and tbx18) were significantly downregulated in the DEHP group at 2 dpf, and three transcription factors (zic3, tcf21, and gata4) were significantly upregulated. Our results emphasize the need for the development of a nontoxic plasticizer to prevent possible deleterious effects on humans and other life-forms.

Impact of organochlorine pollutants on semen parameters of infertile men in Pakistan

Male infertility is a major problem with important socioeconomic consequences. It is associated with several pathological factors, including but not limited to endocrine disruption as a result of environmental pollution and the alarming decline in sperm count over the decades is indicative of involvement of many environmental and lifestyle changes around the globe. Organochlorine pollutants such as dichlorodiphenyltrichlorethanes (DDTs), polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) disrupt male reproductive system but the exact effect of environmental exposure on semen parameters in human is still not clear. This study was designed to monitor PCBs, DDTs and HCB in hair, urine and serum samples of infertile and healthy fertile men. Solid-phase microextraction gas chromatography-mass spectrometry (SPME/GC-MS) was used to monitor analytes. All tested compounds were detected, indicating recent use/persistent accumulation. Hair samples revealed no significant association with serum/urine concentrations of the analytes, while serum/urine concentrations were significantly correlated positively. Concentrations were higher in serum compared to other samples. The levels of organochlorine pollutants were higher in infertile men compared to controls with few exceptions. Among PCBs, and DDTs, PCB-153 and pp'-DDT were detected in highest concentrations, respectively. op'-DDT and pp'-DDT levels were significantly higher in infertile men compared to controls. HCB was significantly correlated negatively with sperm motility in all samples. Serum concentrations of all compounds were higher in men with defective semen parameters compared to normospermics. Serum was the best biological sample for assessing health outcomes in relation to exposure levels.

Endocrine Disruptors Acting on Estrogen and Androgen Pathways Cause Reproductive Disorders through Multiple Mechanisms: A Review

Increasing contamination of the environment by toxic compounds such as endocrine disrupting chemicals (EDCs) is one of the major causes of reproductive defects in both sexes. Estrogen/androgen pathways are of utmost importance in gonadal development, determination of secondary sex characteristics and gametogenesis. Most of the EDCs mediate their action through respective receptors and/or downstream signaling. The purpose of this review is to highlight the mechanism by which EDCs can trigger antagonistic or agonistic response, acting through estrogen/androgen receptors causing reproductive defects that lead to infertility. In vitro, in vivo and in silico studies focusing on the impact of EDCs on estrogen/androgen pathways and related proteins published in the last decade were considered for the review. PUBMED and PUBCHEM were used for literature search. EDCs can bind to estrogen receptors (ERα and ERβ) and androgen receptors or activate alternative receptors such as G protein-coupled receptors (GPCR), GPR30, estrogen-related receptor (ERRγ) to activate estrogen signaling via downstream kinases. Bisphenol A, dichlorodiphenyltrichloroethane, dichlorodiphenyldichloroethylene, polychlorinated biphenyls and phthalates are major toxicants that interfere with the normal estrogen/androgen pathways leading to infertility in both sexes through many ways, including DNA damage in spermatozoids, altered methylation pattern, histone modifications and miRNA expression.

Nephrotoxicity issues of organophosphates

Organophosphates are a large class of chemicals, initially invented in 1850 and since then they have been applied in numerous aspects of science to serve our purposes. Their mechanism of action in living organisms involves the irreversible inhibition of acetylcholinesterase, therefore they interfere with neuromuscular signal transmission. Due to the systematic and exaggerated use of these chemicals, there is massive exposure to them, hence there is great concern regarding the ramifications to all mammalian organisms. It has been widely accepted that over-exposure to organophosphates, has a deleterious impact on the renal tissue and subsequently on the renal function. Despite the significance of this global issue, limited knowledge exists, regarding the effect of these substances on our health. Therefore, new and extensive research is required to expand our knowledge and ensure proper guidance regarding the use of organophosphates as well the protection against their detrimental consequences. The aim of this review is to negotiate the effect of organophosphate exposure on renal tissue and kidney function.

Molecular and clinical aspects of embryotoxicity induced by acetylcholinesterase inhibitors

Acetylcholinesterase inhibitors are widely used for a variety of medical, agricultural and public health purposes. Consequently, exposure is highly possible during lifetime. However, their systematic use raises concerns for the potential impact on the fetus and newborn since these substances may affect angiogenesis, the neonatal and maternal intensive care, neuroimmune function and response, mammary growth/lactation via cholinergic/non-cholinergic central and peripheral neuroendocrine pathways. New methodologies, neuroscientific technologies and research studies are needed to harness existing knowledge along with the proper management, availability for new acetylcholinesterase inhibitors, with stable pharmacodynamics and clinical outcomes.

Association of pesticide exposure with human congenital abnormalities

Human pesticide exposure can occur both occupationally and environmentally during manufacture and after the application of indoor and outdoor pesticides, as well as through consumption via residues in food and water. There is evidence from experimental studies that numerous pesticides, either in isolation or in combination, act as endocrine disruptors, neurodevelopmental toxicants, immunotoxicants, and carcinogens. We reviewed the international literature on this subject for the years between 1990 and 2017. The studies were considered in this review through MEDLINE and WHO resources. Out of the n = 1817 studies identified, n = 94 were reviewed because they fulfilled criteria of validity and addressed associations of interest. Epidemiological studies have provided limited evidence linking pre- and post-natal exposure to pesticides with cancers in childhood, neurological deficits, fetal death, intrauterine growth restriction, preterm birth, and congenital abnormalities (CAs). In this review, the potential association between pesticide exposure and the appearance of some human CAs (including among others musculoskeletal abnormalities; neural tube defects; urogenital and cardiovascular abnormalities) was investigated. A trend towards a positive association between environmental or occupational exposure to some pesticides and some CAs was detected, but this association remains to be substantiated. Main limitations of the review include inadequate exposure assessment and limited sample size. Adequately powered studies with precise exposure assessments such as biomonitoring, are warranted to clarify with certainty the potential association between pesticide exposure and human CAs.

THE POTENTIAL OF DIETHYLHEXYL-PHTHALATE AND GENISTEIN TO INDUCE TESTICULAR CHANGES IN RAT'S OFFSPRING

OBJECTIVE

To study the effect of diethylhexyl phthalate (DEHP) alone or in combination with genistein (GEN) on the reproductive system of offspring rats, focus on the induction of reproductive outcomes.

METHOD

180 Wistar rats were divided in 6 groups (30 animals per group): DEHP 250 mg/kg/day group, DEHP 1000 mg/kg/day group, DEHP 2500 mg/kg/day group treated with DEHP 2500 mg/kg/day, DEHP (2500 mg/kg) + GEN (50 mg/kg) group, DEHP (2500 mg/kg) + GEN (500 mg/kg) group and control group treated with the same quantity of corn oil. The differences in sperm quality and reproductive organs were observed.

RESULTS

After DEHP administration we observed an increase in rat's abestrus, metaestrus and all estrus cycle (P < 0.05), a decrease in rat testicle's organ coefficient and relative energy of testis Sertoli cells and an increase in the early, late and total apoptotic rate of testicular Sertoli cells in a dose dependent manner (P < 0.05). When combine DEHP with GEN the sperm density, sperm quality, the cell activity rate and testis tissue's changes will decrease compared with the group that receive only DEHP in a dose dependent manner.

CONCLUSION

DEHP exposure induces cryptorchidism in offspring rats and this is aggravated by adding GEN.