The potential impacts of circadian rhythm disturbances on male fertility

Research on the perception of pre-semen collection stress and its influencing factors in men on the day of oocyte retrieval in IVF-ET

PURPOSE

This study aimed to investigate the status and influencing factors of perceived stress in men before sperm collection on the day of oocyte retrieval during IVF-ET, thereby providing a theoretical basis for nursing interventions.

METHODS

A cross-sectional survey was conducted using convenience sampling. We examined 507 male IVF-ET patients undergoing sperm collection using a demographic questionnaire, the Generalized Anxiety Disorder Scale, the Perceived Stress Scale, and the Chinese version of the Connor-Davidson Resilience Scale. Univariate analysis, Pearson correlation, and multivariate linear regression were utilized to identify factors affecting perceived stress before sperm collection.

RESULTS

The average score for perceived stress before sperm collection was 14.64 ± 4.54. For generalized anxiety, it was 6.28 ± 3.92; and for psychological resilience, it was 68.14 ± 18.46. Multivariate linear regression analysis revealed that monthly family income, psychological resilience, and anxiety were significant predictors of perceived stress in men before sperm collection (P < 0.05).

CONCLUSIONS

Men experienced mild anxiety and perceived stress before sperm collection on the day of oocyte retrieval, accompanied by moderate psychological resilience. Monthly family income is independent predictors of perceived stress. Anxiety correlates positively with perceived stress and can predict elevated stress levels, while psychological resilience correlates negatively with stress, serving as a protective factor. Nursing staff must address perceived stress, anxiety, and resilience in men undergoing IVF-ET, providing comprehensive information and support to enhance their psychological well-being.

Dexamethasone is a regulator of clock genes in testicular peritubular cells

BACKGROUND

We recently found that peritubular cells of the human testis are a dominant site of expression of the glucocorticoid receptor (GR; encoded by NR3C1). Activation of GR by dexamethasone (Dex) strongly influences the phenotype of cultured human testicular peritubular cells (HTPCs), causing massive changes of their proteome and secretome. As glucocorticoids (GC) are also known to set the internal clock of peripheral organs by regulating clock genes, we tested such an influence of Dex in HTPCs.

METHODS

We performed cellular studies with HTPCs and immortalized nonhuman primate (Callithrix jacchus; Cj)-derived peritubular cells, organotypic incubations of testicular fragments of Cj, qPCR and proteomic, as well as immunohistochemical studies.

RESULTS

Basal clock gene expression levels, when monitored by qPCR under standard culture conditions, showed alterations over 24 h, suggesting an endogenous circadian rhythm, especially for BMAL1. Dex (1 µM) when added to cells, caused a strong and significant increase of PER1, followed by elevations of BMAL1, and other clock genes. This action was observed as early as 4 h after the addition of Dex. Immunohistochemistry and data mining revealed GR in testicular peritubular cells and other somatic cells of Cj, in situ. We therefore performed organotypic incubations of testicular fragments of Cj (n = 3) and found that upon addition of Dex (1 µM), mRNA levels of BMAL1 and PER1 also increased in samples of two out of three animals after 6 h. Mass spectrometry did, however, not reveal significant alterations of the testicular proteome, possibly due to the short time point and/or the fact that the somatic GR-expressing cells represent only a small portion of the testis. In support for this assumption, Dex (1 µM; 6 h) significantly increased mRNA levels of BMAL1 and PER1 in Cj-derived immortalized testicular peritubular cells.

CONCLUSION

The results indicate that an internal clock system likely exists in peritubular cells of the testis and that Dex, via testicular GR expressed by peritubular cells and other somatic cells, is a strong regulator of this system. In a physiological situation, GC thus may be important regulators of the testicular clock, while in a situation of prolonged stress or GC-medication, derangements in clock gene expression may result.

Chrono-Endocrinology in Clinical Practice: A Journey from Pathophysiological to Therapeutic Aspects

This review was aimed at collecting the knowledge on the pathophysiological and clinical aspects of endocrine rhythms and their implications in clinical practice, derived from the published literature and from some personal experiences on this topic. We chose to review, according to the PRISMA guidelines, the results of original and observational studies, reviews, meta-analyses and case reports published up to March 2024. Thus, after summarizing the general aspects of biological rhythms, we will describe the characteristics of several endocrine rhythms and the consequences of their disruption, paying particular attention to the implications in clinical practice. Rhythmic endocrine secretions, like other physiological rhythms, are genetically determined and regulated by a central hypothalamic CLOCK located in the suprachiasmatic nucleus, which links the timing of the rhythms to independent clocks, in a hierarchical organization for the regulation of physiology and behavior. However, some environmental factors, such as daily cycles of light/darkness, sleep/wake, and timing of food intake, may influence the rhythm characteristics. Endocrine rhythms are involved in important physiological processes and their disruption may cause several disorders and also cancer. Thus, it is very important to prevent disruptions of endocrine rhythms and to restore a previously altered rhythm by an early corrective chronotherapy.

Circadian disturbance induces erectile dysfunction by impairing endothelial function

In order to explore the impact of circadian disturbance on erectile function, we randomly divided 24 adult male rats into groups of control (light on at 8:00 a.m. and off at 8:00 p.m.), dark/dark (DD; constant dark), light/light (LL; constant light), and shift dark/light (DL; light off at 8:00 a.m. and on at 8:00 p.m.). Four weeks later, erectile function was measured and corpora cavernosa were harvested for analysis. The maximum intracavernous pressure (mICP) and mICP/mean arterial pressure (MAP) ratio in the DD, LL, and DL groups were significantly lower than that in the control group. The LL and DL groups showed significantly attenuated endothelial nitric oxide synthase (eNOS), while DD, LL, and DL showed reduced neuronal nitric oxide synthase (nNOS) at both mRNA and protein levels. The production of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) was inhibited by altered light/dark cycles to varying degrees. Circadian disturbance impaired endothelial function and contributed to erectile dysfunction. For the core circadian elements, mRNA expression of circadian locomotor output cycles kaput ( Clock ) and brain/muscle aryl-hydrocarbon receptor nuclear translocator-like protein 1 ( Bmal1 ) was elevated in the DL group, but their protein expression was not significantly changed. DD, LL, and DL increased period 1 ( Per1 ) and Per3 levels, while LL and DL increased PER1 levels. No significant difference was found for Per2 levels, and PER2 and PER3 concentrations were not significantly changed. Moreover, LL and DL significantly increased cryptochrome-1 (CRY1) and CRY2 at both mRNA and protein levels. The altered light/dark rat model showed that circadian disturbance contributed to erectile dysfunction probably by impairing endothelial function. Meanwhile, the core circadian elements were detected in the corpora cavernosa, but these were disrupted. However, which circadian element regulates erectile function and how it works need further analysis.

The transcription factor VAX1 in VIP neurons of the suprachiasmatic nucleus impacts circadian rhythm generation, depressive-like behavior, and the reproductive axis in a sex-specific manner in mice

Background

The suprachiasmatic nucleus (SCN) within the hypothalamus is a key brain structure required to relay light information to the body and synchronize cell and tissue level rhythms and hormone release. Specific subpopulations of SCN neurons, defined by their peptide expression, regulate defined SCN output. Here we focus on the vasoactive intestinal peptide (VIP) expressing neurons of the SCN. SCN VIP neurons are known to regulate circadian rhythms and reproductive function.

Methods

To specifically study SCN VIP neurons, we generated a novel knock out mouse line by conditionally deleting the SCN enriched transcription factor, Ventral Anterior Homeobox 1 (Vax1), in VIP neurons (Vax1Vip; Vax1fl/fl:VipCre).

Results

We found that Vax1Vip females presented with lengthened estrous cycles, reduced circulating estrogen, and increased depressive-like behavior. Further, Vax1Vip males and females presented with a shortened circadian period in locomotor activity and ex vivo SCN circadian period. On a molecular level, the shortening of the SCN period was driven, at least partially, by a direct regulatory role of VAX1 on the circadian clock genes Bmal1 and Per2. Interestingly, Vax1Vip females presented with increased expression of arginine vasopressin (Avp) in the paraventricular nucleus, which resulted in increased circulating corticosterone. SCN VIP and AVP neurons regulate the reproductive gonadotropin-releasing hormone (GnRH) and kisspeptin neurons. To determine how the reproductive neuroendocrine network was impacted in Vax1Vip mice, we assessed GnRH sensitivity to a kisspeptin challenge in vivo. We found that GnRH neurons in Vax1Vip females, but not males, had an increased sensitivity to kisspeptin, leading to increased luteinizing hormone release. Interestingly, Vax1Vip males showed a small, but significant increase in total sperm and a modest delay in pubertal onset. Both male and female Vax1Vip mice were fertile and generated litters comparable in size and frequency to controls.

Conclusion

Together, these data identify VAX1 in SCN VIP neurons as a neurological overlap between circadian timekeeping, female reproduction, and depressive-like symptoms in mice, and provide novel insight into the role of SCN VIP neurons.

Spermatogenesis recovery treatment in less than four months from zero to almost 16 million sperms per milliliter after several cycles of steroids in 44-year-old healthy man

The most common external factors that men can have influence on, and improve its own spermatogenesis, are related to lifestyle, habits, stress level, sport activities, nutrition quality, and medications. Steroids became one of the key issues in young men during reproductive stage of life. More and more teenagers who are not even developed yet naturally start using supplements very early to build up body and strengths of muscles in the shortest possible time. In this report is presented the case of 44-year-old (November 2022), healthy, and sporty man, who is 1-2 times per year on steroid cycles since he turned 40th. He had intention to become a father; however after 6 months of the last steroid cycle, sperm count was zero. This case will show what was needed and successfully done within less than 4 months after last steroids administration and the moment when sperm count reached almost 16 million sperms per milliliter. However, it has to be clear that this is unique case and additional tests would be needed on bigger population to confirm fast post steroid sperm count recovery in healthy subjects, using approach from this manuscript.

[Male infertility, environment and lifestyle]

BACKGROUND

Since the 1970s, there has been a quantitative and qualitative decline in sperm parameters. The main hypothesis to explain such a rapid evolution is the involvement of environmental and behavioral phenomena.

METHODS

A bibliographic search limited to English and French literature in men published before 7/2023 was carried out on the links between fertility and pollution, xenobiotics, tobacco, narcotics, cannabis, alcohol, weight, sport, sedentary lifestyle, sleep and anabolics.

RESULTS

Profound changes in lifestyle have occurred over the past 50 years: reduced sleep time, sedentary lifestyle, dietary changes, tobacco consumption, use of narcotics and anabolics. These changes have a proven impact on spermogram parameters, and should be corrected in an effort to optimize reproductive health. Other environmental parameters: pollution, exposure to heavy metals, exposure to xenobiotics, phthalates and pesticides… will be more difficult to exclude from patients' daily lives, but deserve to be taken more into account.

CONCLUSION

This review should help the urologist to assess and counsel patients in order to improve their reproductive health. These factors should be routinely investigated in infertile men.