The circadian clock is an important internal time regulatory system for a range of physiological and behavioral rhythms within living organisms. Testosterone, as one of the most critical sex hormones, is essential for the development of the reproductive system, maintenance of reproductive function, and the overall health of males. The secretion of testosterone in mammals is characterized by distinct circadian rhythms and is closely associated with the regulation of circadian clock genes. Here we review the central and peripheral regulatory mechanisms underlying the influence of circadian clock genes upon testosterone synthesis. We also examined the specific effects of these genes on the occurrence, development, and treatment of common male diseases, including late-onset hypogonadism, erectile dysfunction, male infertility, and prostate cancer.
Testosterone/metabolism* ; Humans ; Male ; Circadian Clocks/genetics* ; Circadian Rhythm Signaling Peptides and Proteins/metabolism* ; Circadian Rhythm/physiology* ; Hypogonadism/metabolism* ; Erectile Dysfunction/metabolism* ; Infertility, Male/metabolism* ; Prostatic Neoplasms/metabolism* ; Men's Health

OBJECTIVE: Previous studies have shown that insomnia is closely related to erectile dysfunction（ED）. However, the causal relationship between them is still unclear. Mendelian randomization (MR) provides a new method for studying the relationship between the two, and the theory of heart-kidney interaction in TCM provides a new idea for exploring the causal relationship between them. METHODS: Based on the statistical data collected by genome-wide association studies (GWAS), the causal relationship between insomnia and ED was discussed by MR. Inverse variance weighted (IVW) is the main analysis method, and weighted median (WME), simple mode (SM), weighted mode (WM) and MR Egger method were the supplementary analysis to evaluate the causal effect. MR-Egger intercept test, Cochran Q test and leave-one-out method were used in sensitivity analysis to verify the reliability of MR results. RESULTS: Thirty-nine SNPs significantly related to insomnia were finally included for MR analysis. The results of IVW method in MR analysis showed that insomnia had a significant causal relationship with the increased risk of ED (OR = 3.111，95% CI= 1.566－6.181，P=1.193×10－3). The results obtained by MR-Egger method, WME method, WM method and SM method were consistent with IVW method in the direction of effect. The sensitivity results suggested that the results of this study were robust. CONCLUSION Our study reveals the causal relationship between insomnia and ED, which provides a new basis for future clinical practice and prevention and treatment of ED.
Causality ; Sleep Initiation and Maintenance Disorders/genetics* ; Erectile Dysfunction/genetics* ; Mendelian Randomization Analysis ; Genome-Wide Association Study ; Humans ; Male ; Heart/physiology* ; Kidney/physiology* ; Polymorphism, Single Nucleotide ; Data Interpretation, Statistical

OBJECTIVE: To evaluate the association between erectile dysfunction (ED) and myocardial infarction (MI) using two sample Mendelian randomization. METHODS: A Mendelian randomization study was conducted using comprehensive data on ED and MI from extensive genome-wide association data. Using inverse variance weighted analysis for causal relationships, and correct for confounding factors using multivariate Mendelian randomization, the potential mediating effects were evaluated as well. Based on Genecard data, the genes related to ED and MI were identified. Molecular docking was used to reveal spontaneously bound drug molecules. RESULTS: Our study found that exposure to ED was a risk factor for MI (OR: 1.001 0, 95% CI: 1.000 2－1.001 8, P=0.017 7), which also held true in the validation dataset (OR: 1.028 5, 95% CI: 1.005 0－1.052 6, P=0.017 2). No statistically significant heterogeneity or horizontal pleiotropy was found. The results of reverse Mendelian randomization analysis showed any reverse causal relationship between ED and MI. In multivariate Mendelian randomization analysis, after excluding confounding factors (excluding triglycerides and high-density lipoprotein), the P-value remained less than 0.05, and the OR ranged from 1.000 1 to 1.000 7, indicating that ED was still a risk factor for MI. In the mediation analysis, it was found that the current mediation ratio of smoking to MI was 13.06%. In summary-data-based mendelian randomization analysis, it was found that the gene PTPN11 was a common target gene for MI and ED (OR=0.990, P<0.001). Subsequent molecular docking with sildenafil, clopidogrel, and dapoxetine could spontaneously bind to the PTPN11 gene receptor. CONCLUSION There is a causal relationship between ED and MI, with smoking as a potential mediating factor, and the gene PTPN11 being a co-target gene.
Humans ; Male ; Mendelian Randomization Analysis ; Myocardial Infarction/genetics* ; Erectile Dysfunction/complications* ; Risk Factors ; Genome-Wide Association Study ; Molecular Docking Simulation ; Polymorphism, Single Nucleotide

Sleep has attracted extensive attention due to its significance in health. However, its association with erectile dysfunction (ED) is insufficiently investigated. To investigate the potential causal links between sleep traits (insomnia, sleep duration, and chronotype) and ED, this study was performed. The single-nucleotide polymorphisms (SNPs) associated with insomnia, sleep duration, and chronotype were retrieved from previous genome-wide association studies (GWAS). A conventional two-sample Mendelian randomization (MR) was used to estimate the causal links between sleep traits and ED. The summary statistics of ED were from individuals of European ancestry (6175 cases vs 217 630 controls). As shown by the random effect inverse-variance-weighting (IVW) estimator, genetically predicted insomnia was causally associated with a 1.15-fold risk of ED (95% confidence interval: 1.07-1.23, P < 0.001). Sleep duration and morningness were not causally associated with ED, as indicated by the IVW (all P > 0.05). These findings were consistent with the results of sensitivity analyses. Based on genetic data, this study provides causal evidence that genetically predicted insomnia increases the risk of ED, whereas sleep duration and chronotype do not.
Male ; Humans ; Sleep Initiation and Maintenance Disorders/genetics* ; Genome-Wide Association Study ; Erectile Dysfunction/genetics* ; Sleep/genetics* ; Phenotype ; Polymorphism, Single Nucleotide

MicroRNAs (miRNAs) are short non-coding RNAs consisting of approximately 19－23 nucleotides and involved in many pathological and physiological processes by regulating post-transcriptional gene expressions. ED is one of the common male sexual dysfunctions seriously affecting the patient's quality of life, for which there is currently a lack of effective treatments clinically. More and more experiments have demonstrated that miRNAs are involved in the pathological process of different types of ED. This article presents an overview of the progress in the studies of the pathogenic role of miRNAs in ED.
Erectile Dysfunction/genetics* ; Gene Expression ; Humans ; Male ; MicroRNAs/genetics* ; Quality of Life

The aim of this study was to investigate the mechanism by which a diet inducing high hyperhomocysteinemia (HHcy) leads to the deterioration of erectile function in rats and whether this is inhibited by expression of the human tissue kallikrein-1 (hKLK1) gene. We established a rat model of HHcy by feeding methionine (Met)-rich diets to male Sprague-Dawley (SD) rats. Male wild-type SD rats (WTRs) and transgenic rats harboring the hKLK1 gene (TGRs) were fed a normal diet until 10 weeks of age. Then, 30 WTRs were randomly divided into three groups as follows: the control (n = 10) group, the low-dose (4% Met, n = 10) group, and the high-dose (7% Met, n = 10) group. Another 10 age-matched TGRs were fed the high-dose diet and designated as the TGR+7% Met group. After 30 days, in all four groups, erectile function was measured and penile tissues were harvested to determine oxidative stress, endothelial cell content, and penis fibrosis. Compared with the 7% Met group, the TGR+7% Met group showed diminished HHcy-induced erectile dysfunction (ED), indicating the improvement caused by hKLK1. Regarding corpus cavernosum endothelial cells, hKLK1 preserved endothelial cell-cell junctions and endothelial cell content, and activated protein kinase B/endothelial nitric oxide synthase (Akt/eNOS) signaling. Fibrosis assessment indicated that hKLK1 preserved normal penis structure by inhibiting apoptosis in the corpus cavernosum smooth muscle cells. Taken together, these findings showed that oxidative stress, impaired corpus cavernosum endothelial cells, and severe penis fibrosis were involved in the induction of ED by HHcy in rats, whereas hKLK1 preserved erectile function by inhibiting these pathophysiological changes.
Animals ; Apoptosis ; Diet ; Endothelial Cells ; Erectile Dysfunction/prevention & control* ; Fibrosis ; Humans ; Hyperhomocysteinemia/complications* ; Male ; Methionine ; Oxidative Stress ; Penis/pathology* ; Rats ; Rats, Sprague-Dawley ; Rats, Transgenic ; Signal Transduction/genetics* ; Tissue Kallikreins/genetics*

We evaluated whether LIM-kinase 2 inhibitor (LIMK2i) could improve erectile function by suppressing corporal fibrosis through the normalization of the Rho-associated coiled-coil protein kinase 1 (ROCK1)/LIMK2/Cofilin pathway in a rat model of cavernous nerve crush injury (CNCI). Sixty 11-week-old male Sprague-Dawley rats were divided equally into five groups: sham surgery (S), CNCI (I), and CNCI treated with low-dose (L), medium-dose (M), and high-dose (H) LIMK2i. The L, M, and H groups were treated with a daily intraperitoneal injection of LIMK2i (2.5, 5.0, and 10.0 mg kg^-1 body weight, respectively) for 1 week after surgery. The erectile response was assessed using electrostimulation at 1 week, postoperatively. Penile tissues were processed for Masson's trichrome staining, double immunofluorescence, and Western blot assay. Erectile responses in the H group improved compared with the I group, while the M group showed only partial improvement. A significantly decreased smooth muscle/collagen ratio and an increased content of fibroblasts positive for phospho-LIMK2 were noted in the I group. The M and H groups revealed significant improvements in histological alterations and the dysregulated LIMK2/Cofilin pathway, except for LIMK2 phosphorylation in the M group. The inhibition of LIMK2 did not affect the ROCK1 protein expression. The content of fibroblasts positive for phospho-LIMK2 in the H group returned to the level found in the S group, whereas it did not in the M group. However, the L group did not exhibit such improvements. Our data suggest that the inhibition of LIMK2, particularly with administration of 10.0 mg kg^-1 body weight LIMK2i, can improve corporal fibrosis and erectile function by normalizing the LIMK2/Cofilin pathway.
Animals ; Cofilin 1/metabolism* ; Electric Stimulation ; Erectile Dysfunction/etiology* ; Fibroblasts/pathology* ; Fibrosis/drug therapy* ; Lim Kinases/antagonists & inhibitors* ; Male ; Penile Diseases/drug therapy* ; Penis/innervation* ; Peripheral Nerve Injuries/pathology* ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; Signal Transduction/drug effects* ; rho-Associated Kinases/genetics*

Men with diabetic erectile dysfunction (ED) respond poorly to the currently available oral phosphodiesterase-5 inhibitors. Therefore, functional therapies for diabetic ED are needed. Stromal vascular fraction (SVF) and the adenovirus-mediated cartilage oligomeric matrix angiopoietin-1 (Ad-COMP-Ang1) gene are known to play critical roles in penile erection. We previously reported that SVF and Ad-COMP-Ang1 have only a short-term effect in restoring erectile function. Further improvements to ED therapy are needed for long-lasting effects. In the present study, we aimed to test if the combination of SVF and Ad-COMP-Ang1 could extend the erection effect in diabetic ED. We found that the combination therapy showed a long-term effect in restoring erectile function through enhanced penile endothelial and neural cell regeneration. Combination therapy with SVF and Ad-COMP-Ang1 notably restored cavernous endothelial cell numbers, pericyte numbers, endothelial cell-cell junctions, decreased cavernous endothelial cell permeability, and promoted neural regeneration for at least 4 weeks in diabetic mice. In summary, this is an initial description of the long-term effect of combination therapy with SVF and Ad-COMP-Ang1 in restoring erectile function through a dual effect on endothelial and neural cell regeneration. Such combination therapy may have therapeutic potential for the treatment of diabetic ED.
Angiopoietin-1/genetics* ; Animals ; Diabetes Mellitus, Experimental/metabolism* ; Endothelium, Vascular/metabolism* ; Erectile Dysfunction/therapy* ; Genetic Therapy/methods* ; Intercellular Junctions/metabolism* ; Male ; Mesenchymal Stem Cell Transplantation ; Mice ; Penile Erection/physiology* ; Permeability

Erectile dysfunction (ED) is a disease associated with a variety of factors such as age, psychological factors, physical conditions, and lifestyle, and it severely affects the patients quality of life. In the past, some non-coding RNAs (ncRNAs) transcribed by genes but not translated into the protein were regarded as the "waste" in the process of gene expression. But in the recent years, ncRNAs have been found to play a crucial role in regulating gene expression and its products, which may affect penile erectile function. This review focuses on the recent progress in the studies of the relationship between ncRNAs and erectile dysfunction.
Erectile Dysfunction ; genetics ; Gene Expression ; Humans ; Male ; Quality of Life ; RNA, Untranslated ; physiology

Erectile dysfunction (ED), as a common male disease, seriously affects the patients' sexual life quality. Most ED patients benefit from phosphodiesterase type 5 (PDE5) inhibitors, but some refractory ED sufferers fail to respond to them. With the rapid development of molecular biology, the relevant molecular signaling pathways of penile erection and molecular pathogenesis of ED have been gradually clarified, and attempts have been made at a better management or a complete cure of ED with advanced molecular biological methods such as the gene therapy. This article presents an overview on the research progress in the molecular signaling pathways, molecular pathogenesis, and gene therapy of ED.
Biomedical Research ; Erectile Dysfunction ; genetics ; therapy ; Genetic Therapy ; Humans ; Male ; Penile Erection ; genetics ; Phosphodiesterase 5 Inhibitors ; therapeutic use ; Quality of Life ; Signal Transduction