Lycopene and male infertility

Excessive amounts of reactive oxygen species （ROS） cause a state of oxidative stress, which result in sperm membrane lipid peroxidation, DNA damage and apoptosis, leading to decreased sperm viability and motility. Elevated levels of ROS are a major cause of idiopathic male factor infertility, which is an increasingly common problem today. Lycopene, the most potent singlet oxygen quencher of all carotenoids, is a possible treatment option for male infertility because of its antioxidant properties. By reacting with and neutralizing free radicals, lycopene could reduce the incidence of oxidative stress and thus, lessen the damage that would otherwise be inflicted on spermatozoa. It is postulated that lycopene may have other beneficial effects via nonoxidative mechanisms in the testis, such as gap junction communication, modulation of gene expression, regulation of the cell cycle and immunoenhancement. Various lycopene supplementation studies conducted on both humans and animals have shown promising results in alleviating male infertility--lipid peroxidation and DNA damage were decreased, while sperm count and viability, and general immunity were increased. Improvement of these parameters indicates a reduction in oxidative stress, and thus the spermatozoa is less vulnerable to oxidative damage, which increases the chances of a normal sperm fertilizing the egg. Human trials have reported improvement in sperm parameters and pregnancy rates with supplementation of 4-8 mg of lycopene daily for 3-12 months. However, further detailed and extensive research is still required to determine the dosage and the usefulness of lycopene as a treatment for male infertility.

Bibliometrics： tracking research impact by selecting Lhe appropriate metrics

Traditionally, the success of a researcher is assessed by the number of publications he or she publishes in peer-reviewed, indexed, high impact journals. This essential yardstick, often referred to as the impact of a specific researcher, is assessed through the use of various metrics. While researchers may be acquainted with such matrices, many do not know how to use them to enhance their careers. In addition to these metrics, a number of other factors should be taken into consideration to objectively evaluate a scientist＇s profile as a researcher and academician. Moreover, each metric has its own limitations that need to be considered when selecting an appropriate metric for evaluation. This paper provides a broad overview of the wide array of metrics currently in use in academia and research. Popular metrics are discussed and defined, including traditional metrics and article-level metrics, some of which are applied to researchers for a greater understanding of a particular concept, including varicocete that is the thematic area of this Special Issue of Asian Journal of Andrology. We recommend the combined use of quantitative and qualitative evaluation using judiciously selected metrics for a more objective assessment of scholarly output and research impact.

Proteomic signatures of infertile men with clinical varicocele and their validation studies reveal mitochondrial dysfunction leading to infertility

To study the major differences in the distribution of spermatozoa proteins in infertile men with varicocele by comparative proteomics and validation of their level of expression. The study-specific estimates for each varicocele outcome were combined to identify the proteins involved in varicocele-associated infertility in men irrespective of stage and laterality of their clinical varicocele. Expression levels of 5 key proteins （PKARIA, AK7, CCT6B, HSPA2, and ODF2） involved in stress response and sperm function including molecular chaperones were validated by Western blotting. Ninety-nine proteins were differentially expressed in the varicocele Eroup. Over 87% of the DEP involved in major energy metabolism and key sperm functions were underexpressed in the varicocele group. Key protein functions affected in the varicocele group were spermatogenesis, sperm motility, and mitochondrial dysfunction, which were further validated by Western blotting, corroborating the proteomics analysis. Varicocele is essentially a state of energy deprivation, hypoxia, and hyperthermia due to impaired blood supply, which is corroborated by down-regulation of lipid metabolism, mitochondrial electron transport chain, and Krebs cycle enzymes. To corroborate the proteomic analysis, expression of the 5 identified proteins of interest was validated by Western blotting. This study contributes toward establishing a biomarker ＂fingerprint＂ to assess sperm quality on the basis of molecular parameters.

Leptin and its actions on reproduction in males

Leptin, an adipocyte-derived hormone, serves numerous physiological functions in the body, particularly during puberty and reproduction. The exact mechanism by which leptin activates the gonadotropin-releasing hormone (GnRH) neurons to trigger puberty and reproduction remains unclear. Given the widespread distribution of leptin receptors in the body, both central and peripheral mechanisms involving the hypothalamic-pituitary-gonadal axis have been hypothesized. Leptin is necessary for normal reproductive function, but when present in excess, it can have detrimental effects on the male reproductive system. Human and animal studies point to leptin as a link between infertility and obesity, a suggestion that is corroborated by findings of low sperm count, increased sperm abnormalities, oxidative stress, and increased leptin levels in obese men. In addition, daily leptin administration to normal-weight rats has been shown to result in similar abnormalities in sperm parameters. The major pathways causing these abnormalities remain unidentified;however, these adverse effects have been attributed to leptin-induced increased oxidative stress because they are prevented by concurrently administering melatonin. Studies on leptin and its impact on sperm function are highly relevant in understanding and managing male infertility, particularly in overweight and obese men.

Spermatozoa protein alterations in infertile men with bilateral varicocele

Among infertile men, a diagnosis of unilateral varicocele is made in 90% of varicocele cases and bilateral in the remaining varicocele cases. However, there are reports of under-diagnosis of bilateral varicocele among infertile men and that its prevalence is greater than 10%. In this prospective study, we aimed to examine the differentially expressed proteins （DEP） extracted from spermatozoa cells of patients with bilateral varicocele and fertile donors. Subjects consisted of 17 men diagnosed with bilateral varicocele and 10 proven fertile men as healthy controls. Using the LTQ-orbitrap elite hybrid mass spectrometry system, proteomic analysis was done on pooled samples from 3 patients with bilateral varicocele and 5 fertile men. From these samples, 73 DEP were identified of which 58 proteins were differentially expressed, with 7 proteins unique to the bilateral varicocele group and 8 proteins to the fertile control group. Majority of the DEPs were observed to be associated with metabolic processes, stress responses, oxidoreductase activity, enzyme regulation, and immune system processes. Seven DEP were involved in sperm function such as capacitation, motility, and sperm-zona binding. Proteins TEKT3 and TCP11 were validated by Western blot analysis and may serve as potential biomarkers for bilateral varicocele. In this study, we have demonstrated for the first time the presence of DEP and identified proteins with distinct reproductive functions which are altered in infertile men with bilateral varicocele. Functional proteomic profiling provides insight into the mechanistic implications of bilateral varicocele-associated male infertility.

Are men talking their reproductive health away？

The advent of mobile phones has revolutionized communication trends across the globe. As the popularity of mobile phone usage continues to escalate, there is now growing concern about the effects of radiofrequency electromagnetic waves （RF-EMW） exposure on biological tissues, such as the brain and testes. Researchers have sought to link the much debated decline in human sperm quality in the last decade, with increased exposure to RF-EMW, particularlythrough mobile phone usage. In a recent systematic review and meta-analysis on the effect of mobile phone RF-EMW radiation on sperm quality, Adams et al.1 demonstrated an association between mobile phone exposure and reduced sperm motility and viability, with inconsistent effects on sperm concentration.1 Results from 10 pooled experimental （in vitro） and observational （in vivo） human studies （n = 1492） led these researchers to suggest that exposure to RF-EMW radiation from carrying a mobile phone in the trouser pocket negatively impacts sperm quality.