The role of vitamin D in male fertility: A focus on the testis

In the last decade, vitamin D has emerged as a pleiotropic molecule with a multitude of autocrine, paracrine and endocrine functions, mediated by classical genomic as well as non-classical non-genomic actions, on multiple target organs and systems. The expression of vitamin D receptor and vitamin D metabolizing enzymes in male reproductive system, particularly in the testis, suggests the occurrence of vitamin D synthesis and regulation as well as function in the testis. The role of vitamin D in the modulation of testis functions, including hormone production and spermatogenesis, has been investigated in animals and humans. Experimental studies support a beneficial effect of vitamin D on male fertility, by modulating hormone production through genomic and non-genomic actions, and, particularly, by improving semen quality essentially through non-genomic actions. However, clinical studies in humans are controversial. Indeed, vitamin D seems to contribute to the modulation of the bioavailable rather than total testosterone. Moreover, although an increased prevalence or risk for testosterone deficiency was reported in men with vitamin D deficiency in observational studies, the majority of interventional studies demonstrated the lack of effect of vitamin D supplementation on circulating levels of testosterone. The most consistent effect of vitamin D was reported on semen quality. Indeed, vitamin D was shown to be positively associated to sperm motility, and to exert direct actions on spermatozoa, including non-genomic driven modulation of intracellular calcium homeostasis and activation of molecular pathways involved in sperm motility, capacitation and acrosome reaction. The current review provides a summary of current knowledge on the role of vitamin D in male fertility, by reporting clinical and experimental studies in humans and animals addressing the relationship between vitamin D and testis function

Smoke, alcohol and drug addiction and male fertility

In recent decades, the decline in human fertility has become increasingly more worrying: while therapeutic interventions might help, they are vexing for the couple and often burdened with high failure rates and costs. Prevention is the most successful approach to fertility disorders in males and females alike. We performed a literature review on three of the most common unhealthy habits - tobacco, alcohol and drug addiction - and their reported effects on male fertility. Tobacco smoking is remarkably common in most first-world countries; despite a progressive decline in the US, recent reports suggest a prevalence of more than 30% in subjects of reproductive age - a disturbing perspective, given the well-known ill-effects on reproductive and sexual function as well as general health. Alcohol consumption is often considered socially acceptable, but its negative effects on gonadal function have been consistently reported in the last 30 years. Several studies have reported a variety of negative effects on male fertility following drug abuse - a worrying phenomenon, as illicit drug consumption is on the rise, most notably in younger subjects. While evidence in these regards is still far from solid, mostly as a result of several confounding factors, it is safe to assume that cessation of tobacco smoking, alcohol consumption and recreational drug addiction might represent the best course of action for any couple trying to achieve pregnancy

Serum epidermal growth factor predicts cognitive functions in early, drug-naive Parkinson's disease patients

Epidermal growth factor (EGF) has been proposed as a candidate biomarker for cognitive impairment in Parkinson's disease (PD). We aimed to assess the relationship between serum EGF and cognitive functions in early, drug-naive PD patients and evaluate the predictive value of EGF on cognitive functions in a 2-year follow-up study. Serum EGF was measured in 65 early, drug-naive PD patients, that underwent a comprehensive neuropsychological battery. Motor symptoms were assessed by means of the Unified Parkinson's Disease Rating Scale, Part III (UPDRS-III). Neuropsychological evaluation was repeated after 2 years. Spearman's rank correlation was used to assess the relationship between serum EGF levels and neuropsychological variables. Linear regression analysis was used to evaluate the relationship between EGF and neuropsychological scores as well as other variables (age, gender, UPDRS-III, levodopa equivalent dose, and type of treatment at follow-up) potentially affecting cognitive performance. Variation over time in cognitive scores was analyzed using repeated-measures ANOVA. At baseline, EGF was the only significant variable associated with performance on semantic fluency (R (2) = 0.131; p = 0.005). EGF levels (p = 0.025), together with UPDRS-III (p = 0.009) and age (p = 0.011), were associated with performance on frontal assessment battery (R (2) = 0.260). At 2-year follow-up, EGF was the only significant variable to predict performance on semantic fluency (R (2) = 0.147; p = 0.025) and color naming task of Stroop color-word test (R (2) = 0.121; p = 0.044). Serum EGF levels are related to frontal and temporal cognitive functions in early, drug-naive PD patients and predict performance on frontal and posterior cognitive functions at 2-year follow-up. EGF is proposed as a potential serum biomarker for early cognitive impairment in PD

Is diabetes in Cushing's syndrome only a consequence of hypercortisolism?

OBJECTIVE: Diabetes mellitus (DM) is one of the most frequent complications of Cushing's syndrome (CS). The aim of this study was to define the changes in insulin sensitivity and/or secretion in relation to glucose tolerance categories in newly diagnosed CS patients. DESIGN: Cross-sectional study on 140 patients with CS. METHODS: A total of 113 women (80 with pituitary disease and 33 with adrenal disease, aged 41.7±15.7 years) and 27 men (19 with pituitary disease and eight with adrenal disease, aged 38.1±20.01 years) at diagnosis were divided according to glucose tolerance into normal glucose tolerance (CS/NGT), impaired fasting glucose and/or impaired glucose tolerance (CS/prediabetes), and diabetes (CS/DM) groups. RESULTS: Seventy-one patients had CS/NGT (49.3%), 26 (18.5%) had CS/prediabetes and 43 (30.8%) had CS/DM. Significant increasing trends in the prevalence of family history of diabetes (P<0.001), metabolic syndrome (P<0.001), age (P<0.001) and waist circumference (P=0.043) and decreasing trends in HOMA-β (P<0.001) and oral disposition index (DIo) (P<0.002) were observed among the groups. No significant trends in fasting insulin levels, area under the curve for insulin (AUCINS), Matsuda index of insulin sensitivity (ISI-Matsuda) and visceral adiposity index were detected. CONCLUSIONS: Impairment of glucose tolerance is characterized by the inability of β-cells to adequately compensate for insulin resistance through increased insulin secretion. Age, genetic predisposition and lifestyle, in combination with the duration and degree of hypercortisolism, strongly contribute to the impairment of glucose tolerance in patients with a natural history of CS. A careful phenotypic evaluation of glucose tolerance defects in patients with CS proves useful for the identification of those at a high risk of metabolic complications

The dual targeting of insulin and insulin-like growth factor 1 receptor enhances the mTOR inhibitor-mediated antitumor efficacy in hepatocellular carcinoma

Deregulation of mTOR and IGF pathways is frequent in hepatocellular carcinoma (HCC), thus mTOR and IGF1R represent suitable therapeutic targets in HCC. The aim of this study was to evaluate the effects of mTOR inhibitors (mTORi) and OSI-906, blocker of IGF1R/IR, on HCC cell proliferation, viability, migration and invasion, and alpha-fetoprotein (α-FP) secretion. In HepG2 and HuH-7 we evaluated, the expression of mTOR and IGF pathway components; the effects of Sirolimus, Everolimus, Temsirolimus and OSI-906 on cell proliferation; the effects of Sirolimus, OSI-906, and their combination, on cell secretion, proliferation, viability, cell cycle, apoptosis, invasion and migration. Moreover, intracellular mechanisms underlying these cell functions were evaluated in both cell lines. Our results show that HepG2 and HuH-7 present with the same mRNA expression profile with high levels of IGF2. OSI-906 inhibited cell proliferation at high concentration, while mTORi suppressed cell proliferation in a dose-time dependent manner in both cell lines. The co-treatment showed an additive inhibitory effect on cell proliferation and viability. This effect was not related to induction of apoptosis, but to G0/G1 phase block. Moreover, the co-treatment prevented the Sirolimus-induced AKT activation as escape mechanism. Both agents demonstrated to be differently effective in inhibiting α-FP secretion. Sirolimus, OSI-906, and their combination, blocked cell migration and invasion in HuH-7. These findings indicate that, co-targeting of IGF1R/IR and mTOR pathways could be a novel therapeutic approach in the management of HCC, in order to maximize antitumoral effect and to prevent the early development of resistance mechanisms