Physiology of Erection and Pathophysiology of Erectile Dysfunction

Exosomes secreted by adipose mesenchymal stem cells overexpressing circPIP5K1C exert

BACKGROUND

Erectile dysfunction (ED) seriously affects men's normal life, and obstructive sleep apnoea (OSA) has been diagnosed as a causative factor. Currently, exosomes secreted by adipose mesenchymal stem cells (ADSC) have been used in the non-clinical experimental treatment of ED disease with prominent efficacy due to the advantages of high stability and no immune exclusion.

METHODS

In this study, chronic intermittent hypoxia (CIH) exposure was used to induce ED-corresponding phenotypes in Sprague Dawley (SD) rats as well as in cavernous smooth muscle cells (CCSMCs). ED symptoms were treated using exosomes secreted by ADSCs overexpressing circPIP5K1C (EXO-circ) injected into the rat corpus cavernosum.

RESULTS

EXO-circ has the effect of ameliorating ED induced by CIH exposure in rats, the mechanism of which is to promote the expression of the downstream target gene SMURF1 after adsorption of miR-153-3p through the sponge so that SMURF1 and PFKFB3 occur protein-protein binding and ubiquitination degradation of PFKFB3 appears to inhibit the occurrence of spongiotic smooth muscle cells glycolysis, and to restore the function of the smooth muscle.

CONCLUSIONS

These findings show that EXO-circ have a promising therapeutic potential in OSA-induced ED.

The role of Cistanches Herba and its ingredients in improving reproductive outcomes: A comprehensive review

BACKGROUND

Infertility patients account for an astonishing proportion of individuals worldwide. Due to its complex etiology and challenging treatment, infertility has imposed significant psychological and economic burdens on many patients. C. Herba (Cistanche tubulosa (Schenk) Wight and Cistanche deserticola Ma), renowned as one of the most prominent Chinese herbal medicines (CHMs), is abundant in diverse bioactive compounds that exhibit therapeutic effects on many diseases related to oxidative stress (OS) and disorders of sex hormone levels.

OBJECTIVE

Due to the limited drugs currently used in clinical practice to improve reproductive outcomes and their inevitable side effects, developing safe and effective new medications for infertility is of significance. This article comprehensively reviewed the phytochemicals of C. Herba, focusing on their efficacy and mechanisms on infertility and their safety for the first time, aiming to offer valuable insights for the development and application of C. Herba, and for developing novel strategies for treating infertility.

METHODS

We used "Cistanche" and its known bioactive components in combination with "sperm", "testicles", "epididymis", "ovaries", "uterus", and "infertility" as keywords to search in PubMed, Web of Science, Scopus and CNKI up to November 2023. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guideline was followed.

RESULTS

The therapeutic effects of C. Herba on infertility are mainly attributed to echinacoside (ECH), verbascoside (VB), salidroside (SAL), polysaccharides, and betaine. They can effectively improve spermatogenic dysfunction, gonadal dysfunction and erectile dysfunction (ED) by exerting anti-oxidation, sex hormones regulation and anti-hypoxia. Moreover, they can also improve premature ovarian failure (POF), ovarian and uterine cancer, oocyte maturation by exerting anti-oxidation, anti-apoptosis, and anti-cancer. C. Herba and its active ingredients also exhibit pleasing safety.

CONCLUSION

C. Herba is a promising source of natural medicine for infertility. Additionally, compared to current therapeutic drugs, its favorable safety also supports its development as a nutritional supplement. However, high-quality clinical studies are required to validate its effectiveness for the development of novel therapeutic strategies.

Polystyrene nanoplastics exposure causes erectile dysfunction in rats

Polystyrene nanoplastics (PS-NPs), emerging and increasingly pervasive environmental contaminants, have the potential to cause persistent harm to organisms. Although previous reports have documented local accumulation and adverse effects in a variety of major organs after PS-NPs exposure, the impact of PS-NPs exposure on erectile function remains unexplored. Herein, we established a rat model of oral exposure to 100 nm PS-NPs for 28 days. To determine the best dose range of PS-NPs, we designed both low-dose and high-dose PS-NPs groups, which correspond to the minimum and maximum human intake doses, respectively. The findings indicated that PS-NPs could accumulate within the corpus cavernosum and high dose but not low dose of PS-NPs triggered erectile dysfunction. Moreover, the toxicological effects of PS-NPs on erectile function include fibrosis in the corpus cavernous, endothelial dysfunction, reduction in testosterone levels, elevated oxidative stress and apoptosis. Overall, this study revealed that PS-NPs exposure can cause erectile dysfunction via multiple ways, which provided new insights into the toxicity of PS-NPs.

Global prevalence of erectile dysfunction and its associated risk factors among men with type 1 diabetes: a systematic review and meta-analysis

Various observational studies have examined the prevalence and determinants of erectile dysfunction (ED) in men with type 1 diabetes across different geographical areas. Nevertheless, a comprehensive systematic review and meta-analysis to consolidate the worldwide prevalence and risk factors remains lacking. Hence, the primary study objective was to perform an extensive systematic review and meta-analysis that specifically examined ED prevalence and determinants in men with type 1 diabetes. A thorough exploration was conducted by examining electronic databases, such as PubMed, Embase, and Web of Science. The general ED prevalence and a 95% confidence interval (CI) in men with type 1 diabetes were summarized. The relevant risk factors were analyzed by deriving a comprehensive odds ratio (OR) from merging the ORs using fixed- or random-effects models. The sources of heterogeneity were investigated using subgroup analyses and meta-regression. This systematic review and meta-analysis included 19 articles involving 3788 men with type 1 diabetes. The meta-analysis revealed that men with type 1 diabetes had a combined ED prevalence of 42.5% (95% CI: 34.3%-50.8%). This prevalence showed significant heterogeneity (I2 = 96.2%, P < 0.01). Meta-regression revealed that age (P = 0.016) and type 1 diabetes duration (P = 0.004) were significant causes of heterogeneity. Furthermore, the ED risk in men with type 1 diabetes was significantly influenced by age, type 1 diabetes duration, body mass index, glycated hemoglobin (HbA1c), retinopathy, and smoking habits (all P < 0.05). In summary, this systematic review and meta-analysis revealed a significant prevalence of ED in men with type 1 diabetes, highlighting the importance of clinicians addressing concerns regarding ED in this specific group of individuals.

Differences in ocular adverse events associated with phosphodiesterase-5 inhibitors: a real-world pharmacovigilance study

OBJECTIVE

Our study aims to characterize the ocular safety profiles of phosphodiesterase type 5 (PDE5) inhibitors and explore the differences among different PDE5 inhibitors.

METHODS

We analyzed reports on ocular adverse events associated with sildenafil, vardenafil and tadalafil submitted to the FDA Adverse Event Reporting System (FAERS) database from the first quarter of 2004 to the first quarter of 2023. Disproportionality analysis was conducted to evaluate reporting risk profiles.

RESULTS

Among 61,211 reports qualifying for analysis, 5,127 involved sildenafil, 832 vardenafil, and 3,733 tadalafil. All PDE5 inhibitors showed increased reporting odds ratios (ROR) for ocular adverse events, with vardenafil highest (ROR 4.47) followed by sildenafil and tadalafil. Key ocular adverse events included cyanopsia, optic ischemic neuropathy, visual field defects, unilateral blindness and blindness. Sildenafil showed the highest disproportionality for cyanopsia (ROR 1148.11) while vardenafil and tadalafil showed the highest disproportionality for optic ischemic neuropathy. Time-to-onset analysis also revealed significant differences, with sildenafil having a later median time-to-onset compared to vardenafil and tadalafil.

CONCLUSIONS

This comprehensive pharmacovigilance study reveals distinct patterns of ocular adverse events associated with PDE5 inhibitors. These findings contribute to a better understanding of the safety profiles of PDE5 inhibitors and may guide healthcare professionals in clinical decision-making.

Treatment of sexual dysfunction induced by hyperprolactinemia accompanied by reduced luteinizing hormone levels: A case report

Key Clinical Message

Sexual dysfunction induced by hyperprolactinemia accompanied by reduced luteinizing hormone (LH) is common in anrology clinics. A low dose of bromocriptine is helpful for restoring penile erectile function and libido in patients.

Abstract

Sexual dysfunction is closely related to hormonal disorders, of which prolactin (PRL) and luteinizing hormone (LH) disorders are common. How to treat sexual dysfunction induced by hyperprolactinemia accompanied by reduced LH levels is worth discussing. In this study, we aimed to present the case of a 35-year-old male patient with sexual dysfunction. The treatment process and physical and laboratory examination results were recorded. Before treatment, the PRL and LH levels in this patient were 31.27 ng/mL and 1.62 mIU/mL, respectively. The International Index of Erectile Function-5 (IIEF-5) score was initially 14 points. After regular treatment with low doses of bromocriptine and tadalafil, the hormonal disorder was corrected (PRL: 11.16 ng/mL and LH: 2.28 mIU/mL) and sexual function was recovered (IIEF-5: 23 points). This case report suggested a sufficient exposure to low-dose bromocriptine for such patients. Conversely, the exogenous supplementation of human chorionic gonadotropin may not be appropriate.

Dietary calcium, phosphorus, and potassium intake associated with erectile dysfunction in the National Health and Nutrition Examination Survey (NHANES) 2001 to 2004

BACKGROUND

Erectile dysfunction is now a common disorder of sexual function, and its relationship to dietary calcium, phosphorus, and potassium has not been well studied. We set out to determine if dietary intakes of calcium, phosphorus, and potassium are related to erectile dysfunction in U.S. men.

METHODS

For this cross-sectional investigation, we used data from NHANES 2001-2004. To investigate the connection of dietary calcium, phosphorus, and potassium intake with erectile dysfunction, we employed multivariate logistic regression, smoothed curve fitting, and subgroup analysis.

RESULTS

This cross-sectional study comprised 3,556 eligible male subjects in total, with a weighted mean age of 49.93±18.13 years. After controlling for race and age, the greatest tertile of calcium consumption was found to have a 34% lower risk of erectile dysfunction than the lowest tertile (OR = 0.66; 95% CI = 0.52-0.84; p = 0.0006). The risk of erectile dysfunction was found to be reduced by 33% (OR = 0.67; 95% CI = 0.52-0.87; p = 0.0024) for the highest tertile of phosphorus intake compared to the lowest tertile of phosphorus intake and by 35% (OR = 0.65; 95% CI = 0.50-0.83; p = 0.0006) for the highest tertile of potassium intake compared to the lowest tertile of potassium intake in the fully adjusted model.

CONCLUSION

Erectile dysfunction and dietary consumption of calcium, phosphorus, and potassium are inversely associated with the U.S. population. To confirm the accuracy of our findings, additional prospective studies are necessary. Furthermore, it is imperative to do further fundamental research at the molecular level to gain a deeper understanding of the underlying mechanisms.

Fibroblasts enable penile erection

Perivascular fibroblasts may underlie erectile dysfunction.

Soluble guanylate cyclase stimulators and activators: new horizons in the treatment of priapism associated with sickle cell disease

Priapism, defined as a prolonged and often painful penile erection occurring without sexual stimulation or desire, is a common complication in sickle cell disease (SCD), affecting up to 48% of male patients. This condition presents significant clinical challenges and can lead to erectile dysfunction if not properly managed. Current pharmacological treatments for SCD-related priapism are primarily reactive rather than preventative, highlighting a gap in effective medical intervention strategies. A critical factor in developing priapism is the reduced basal bioavailability of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) in erectile tissues. New prevention strategies should ideally target the underlying pathophysiology of the disease. Compounds that stimulate and activate soluble guanylate cyclase (sGC) emerge as potential therapeutic candidates since these compounds have the property of inducing cGMP production by sGC. This review explores the potential of sGC stimulators and activators in treating priapism associated with SCD. We discuss the advantages of these agents in the face of the challenging pathophysiology of SCD. Additionally, the review underscores the impact of intravascular hemolysis and oxidative stress on priapism pathophysiology in SCD, areas in which sGC stimulators and activators may also have beneficial therapeutic effects.

Analysis of vacuum negative pressure therapy and traditional Chinese medicine lavage in combination with tadalafil for vascular erectile dysfunction

This study investigates the clinical effects of the novel Traditional Chinese Medicine (TCM) topical wash used in combination with negative pressure irrigation and tadalafil for the treatment of vascular erectile dysfunction. Eighty-seven patients with vascular erectile dysfunction were divided into an observation group and a control group. The observation group was administered negative pressure irrigation (TCM) in combination with oral tadalafil for four weeks, and the control group was administered oral tadalafil for four weeks. The observation group included 21 patients with arterial erectile dysfunction and 22 with intravenous erectile dysfunction. After treatment, IIEF-5, EHS, GAD scores, PSV, EDV and RI in observation group were improved compared with those before treatment (P = 0.000, 0.000, 0.000, L0.000/R0.000, L0.000/R0.000, L0.003/R0.000). Erectile function (IIEF-5, EHS) was significantly improved compared with the control group (P = 0.008, 0.002). In the observation group, there were 21 cases of arterial erectile dysfunction and 22 cases of intravenous erectile dysfunction. After treatment, PSV of arterial ED improved significantly (P = L0.000/R0.000), but EDV did not decrease significantly (P = L0.084/R 0.098). In patients with venous ED, PSV increased (P = L0.026/R0.032) and EDV decreased significantly (P = L0.000/R0.000). These findings suggest that TCM negative pressure lavage combined with tadalafil improves the blood supply of the penile artery, relaxes smooth muscle, and improves the closing mechanism of venous vessels in patients with vascular erectile dysfunction, ultimately improving the erectile function.

The value of audiovisual sexual stimulation with virtual reality in diagnosing erectile dysfunction

Background

The traditional audiovisual sexual stimulation (AVSS) test may experience limitations including low erectile response rate and lack of unified diagnostic criteria.

Aim

We aimed to explore the clinical value of AVSS with virtual reality (VR-AVSS) test in assessing erectile function and diagnosing erectile dysfunction (ED).

Methods

Participants 18 to 60 years of age were screened for analysis in 3 clinical centers from June 2020 to March 2022. Demographic data, 5-item International Index of Erectile Function (IIEF-5), erectile hardness score (EHS), and self-reported symptom questions were collected. The ED patients and control patients were confirmed according to the IIEF-5 and EHS. All subjects watched a 60-minute erotic video by VR device during RigiScan recording. The parameters including tip average rigidity, tip effective erectile duration (duration of rigidity ≥60%, tip effective erectile duration), base average rigidity, and base effective erectile duration were evaluated.

Outcomes

The main outcome of interest was the application of VR immersion technology to improve the traditional AVSS test.

Results

A total of 301 ED cases and 100 eligible control patients were included for final analysis. Compared with control patients, ED cases had significantly lower IIEF-5 scores, EHS, positive response rate, and erectile rigidity and duration. The positive response rate of ED and control patients were 75.5% and 90.9%, respectively. The cutoff points of tip average rigidity, tip effective erectile duration, base average rigidity, and base effective erectile duration were 40.5% (sensitivity: 77.6%, specificity: 70.2%; P < .001), 4.75 minutes (sensitivity: 75.9%, specificity: 75.4%; P < .001), 48.5% (sensitivity: 77.6%, specificity: 75.1%; P < .001), and 7.75 minutes (sensitivity: 79.3%, specificity: 75.7%; P < .001).

Clinical Implications

The technological superiority of VR will enable the VR-AVSS immersion test to be a more accurate detection than traditional AVSS modes.

Strengths and Limitations

Our study applied VR immersion technology to establish the standard operation procedure for the AVSS test, which could effectively reduce the interference of adverse factors and minimize the detecting errors. However, the test data only included positive response subjects, so the true erectile status of men with a negative response to the AVSS test cannot be obtained.

Conclusions

The VR-AVSS test can effectively improve the diagnostic accuracy of ED. The average rigidity and effective erectile duration were the optimal diagnostic parameters for excluding ED.

Predicting Anxiety and Depression Among Erectile Dysfunction Patients: A Cross-Sectional Study

In Vietnam, erectile dysfunction (ED) is prevalent and recognized to be associated with mental disorders; however, societal taboos impede a comprehensive understanding of this connection. Our study aims to investigate the factors related to higher levels of anxiety and/or depression (HAD) in individuals with ED. Between November 2022 and March 2023, a face-to-face survey was conducted at the Center for Andrology of Viet Duc University Hospital, involving 390 patients diagnosed with ED. The survey included 51 questions covering general patient information, the International Index of Erectile Function-15 (IIEF-15), the Patient Health Questionnaire-9 (PHQ-9), and the Generalized Anxiety Disorder-7 (GAD-7). The stepwise Akaike Information Criterion (AIC) method was used to identify factors associated with HAD. The study revealed an average age of 37.63 (11.84) years among participants, with a HAD prevalence of 17.69%. Several factors were associated with a higher likelihood of belonging to the HAD group in ED patients. These factors included non-office workers (OR: 1.11; 95% CI: [1.01, 1.21], p = .025), medium and high levels of work-related stress (OR: 1.23; [1.06, 1.44], p = .008; OR: 1.22; [1.04, 1.45], p = .018), multiple shameful experiences related to ED (OR: 1.16; [1.08, 1.25], p < .001), moderate and severe ED (OR: 1.17; [1.03, 1.32], p = .013; OR: 1.31; [1.14, 1.51], p < .001), and dissatisfaction with intercourse skills (OR: 1.09; [1.01, 1.17], p = .028). Our findings suggest a 16% higher likelihood of HAD status in individuals with multiple shameful experiences related to ED, while moderate and severe ED are associated with respective increases of 17% and 31% in the likelihood. These findings emphasize the importance of considering mental health in the care of individuals with ED.

Sildenafil Reverses the Neuropathological Alzheimer's Disease Phenotype in Cholinergic-Like Neurons Carrying the Presenilin 1 E280A Mutation

Background

Familial Alzheimer's disease (FAD) presenilin 1 E280A (PSEN 1 E280A) is characterized by functional impairment and the death of cholinergic neurons as a consequence of amyloid-β (Aβ) accumulation and abnormal phosphorylation of the tau protein. Currently, there are no available therapies that can cure FAD. Therefore, new therapies are urgently needed for treating this disease.

Objective

To assess the effect of sildenafil (SIL) on cholinergic-like neurons (ChLNs) harboring the PSEN 1 E280A mutation.

Methods

Wild-type (WT) and PSEN 1 E280A ChLNs were cultured in the presence of SIL (25μM) for 24 h. Afterward, proteinopathy, cell signaling, and apoptosis markers were evaluated via flow cytometry and fluorescence microscopy.

Results

We found that SIL was innocuous toward WT PSEN 1 ChLNs but reduced the accumulation of intracellular Aβ fragments by 87%, decreased the non-physiological phosphorylation of the protein tau at residue Ser202/Thr205 by 35%, reduced the phosphorylation of the proapoptotic transcription factor c-JUN at residue Ser63/Ser73 by 63%, decreased oxidized DJ-1 at Cys106-SO3 by 32%, and downregulated transcription factor TP53 (tumor protein p53), BH-3-only protein PUMA (p53 upregulated modulator of apoptosis), and cleaved caspase 3 (CC3) expression by 20%, 32%, and 22%, respectively, compared with untreated mutant ChLNs. Interestingly, SIL also ameliorated the dysregulation of acetylcholine-induced calcium ion (Ca2+) influx in PSEN 1 E280A ChLNs.

Conclusions

Although SIL showed no antioxidant capacity in the oxygen radical absorbance capacity and ferric ion reducing antioxidant power assays, it might function as an anti-amyloid and antiapoptotic agent and functional neuronal enhancer in PSEN 1 E280A ChLNs. Therefore, the SIL has therapeutic potential for treating FAD.

Novel erectile analyses revealed augmentable penile Lyve-1, the lymphatic marker, expression

Purpose

The pathophysiology of penis extends to erectile dysfunction (ED) to conditions including sexually transmitted diseases (STDs) and cancer. To date, there has been little research evaluating vascular drainage from the penis. We aimed to evaluate penile blood flow in vivo and analyze its possible relationship with the lymphatic maker.

Materials and Methods

We established an in vivo system designed to assess the dynamic blood outflow from the corpus cavernosum (CC) by dye injection. To analyze lymphatic characteristics in the CC, the expression of Lyve-1, the key lymphatic endothelium marker, was examined by the in vitro system and lipopolysaccharide (LPS) injection to mimic the inflammatory conditions.

Results

A novel cavernography methods enable high-resolution morphological and functional blood drainage analysis. The expression of Lyve-1 was detected along the sinusoids. Furthermore, its prominent expression was also observed after penile LPS injection and in the erectile condition.

Conclusions

The current in vivo system will potentially contribute to the assessment of penile pathology from a novel viewpoint. In addition, current analyses revealed inducible Lyve-1 expression for LPS injection and the erection state, which requires further analyses on penile lymphatic system.

Predictive value of Prognostic Nutritional Index (PNI) for the severity of vasculogenic erectile dysfunction

PURPOSE

Our aim was to investigate the association of prognostic nutritional index (PNI) score with erectile dysfunction (ED), therefore, we prospectively evaluated the relationship between penile doppler ultrasonography (PDU) findings, PNI and Sexual Health Inventory for Men (SHIM) scores in patients with ED.

METHODS

A total of 414 patients' characteristics, laboratory findings, SHIM and PNI scores were recorded. The PNI is calculated using the formula: 10 × serum albumin + 0.005 × total lymphocyte count. PDU was performed in patients with a SHIM score of 17 and below, while patients with a SHIM score ≥ 18 were recruited for the control group. Correlation analysis was performed to evaluate the relationship between PNI, SHIM scores and PDU parameters. The predictive value of variables for severe ED was assessed with regression analysis.

RESULTS

A significant difference was demonstrated between the ED subgroups and control group for total cholesterol (p = 0.04), serum albumin (p = 0.03), total lymphocyte count (p = 0.02), BDI score (p < 0.001), and PNI score (p = 0.03). A strong positive correlation between PNI score and PSV (rho = 0.73; p = 0.001), a moderate negative correlation between PNI score and EDV (rho = - 0.54; p = 0.02), and a moderate positive correlation between PNI and SHIM scores (rho = 0.61; p = 0.02) were demonstrated. PNI score ≤ 40 (OR: 3.49; p = 0.01), age (OR: 2.15; p = 0.03) and total cholesterol (OR: 2.03; p = 0.04) were determined as significant predictors of severe ED in multivariate analysis.

CONCLUSION

Our results demonstrated that PNI score is significantly lower in patients with severe and moderate ED. It has been also revealed that the PNI score is an independent predictive factor for severe ED.

Hydroxyurea does not reverse functional alterations of the nitric oxide-cGMP pathway associated with priapism phenotype in corpus cavernosum from sickle cell mouse

Sickle cell disease (SCD) is a genetic disorder that has been associated with priapism. The role of hydroxyurea, a common SCD therapy, in influencing the nitric oxide (NO)-cGMP pathway and its effect on priapism is unclear. To investigate the effect of hydroxyurea treatment on smooth muscle relaxation of corpus cavernosum induced by stimulation of the NO-cGMP pathway in SCD transgenic mice and endothelial NO synthase gene-deficient (eNOS-/-) mice, which are used as model of priapism associated with the low bioavailability of endothelial NO. Four-month-old wild-type (WT, C57BL/6), SCD transgenic, and eNOS-/- male mice were treated with hydroxyurea (100 mg/Kg/day) or its vehicle (saline) daily for three weeks via intraperitoneal injections. Concentration-response curves for acetylcholine (ACh), sodium nitroprusside (SNP), and electrical field stimulation (EFS) were generated using strips of mice corpus cavernosum. The SCD mice demonstrated an amplified CC relaxation response triggered by ACh, EFS, and SNP. The corpus cavernosum relaxation responses to SNP and EFS were found to be heightened in the eNOS-/- group. However, the hydroxyurea treatment did not alter these escalated relaxation responses to ACh, EFS, and SNP in the corpus cavernosum of the SCD group, nor the relaxation responses to EFS and SNP in the eNOS-/- group. In conclusion, hydroxyurea is not effective in treating priapism associated with SCD. It is likely that excess plasma hemoglobin and reactive oxygen species, which are reported in SCD, are reacting with NO before it binds to GCs in the smooth muscle of the corpus cavernosum, thus preventing the restoration of baseline NO/cGMP levels. Furthermore, the downregulation of eNOS in the penis may impair the pharmacological action of hydroxyurea at the endothelial level in SCD mice. This study emphasize the urgency for exploring alternative therapeutic avenues for priapism in SCD that are not hindered by high plasma hemoglobin and ROS levels.

Efficacy and safety assessment of traditional Chinese medicine for erectile dysfunction: A meta-analysis and trial sequential analysis

BACKGROUND

Several patients with erectile dysfunction do not accept or benefit from conventional therapy with phosphodiesterase type 5 inhibitors; thus, alternative and complementary therapies are in need. Traditional Chinese medicine has been treating erectile dysfunction in China, but its clinical value is inconclusive.

OBJECTIVE

To systematically evaluate the efficacy and safety of traditional Chinese medicine in treating erectile dysfunction.

METHODS

Randomized controlled trials were retrieved from a comprehensive search in the literature published in the past decade from the Web of Science, PubMed, Embase, Cochrane Library, SinoMed, China National Knowledge Internet, WanFang, and VIP. We performed a meta-analysis of the International Index of Erectile Function 5 questionnaire scores, clinical recovery rates, and testosterone levels using Review Manager 5.4 software. The trial sequential analysis was conducted to check the results.

RESULTS

A total of 45 trials with 5016 patients were included. Meta-analysis results showed that traditional Chinese medicine effectively improved the International Index of Erectile Function 5 questionnaire scores (weighted mean difference = 3.78, 95% confidence interval: 3.12, 4.44; p < 0.001), clinical recovery rates (risk ratio = 1.57, 95% confidence interval: 1.38, 1.79; p < 0.001), testosterone levels (weighted mean difference = 2.42, 95% confidence interval: 1.59, 3.25; p < 0.001) compared with the controls. The single and add-on applications of traditional Chinese medicine could improve the International Index of Erectile Function 5 questionnaire score (p < 0.001). The trial sequential analysis confirmed the robustness of the analysis of the International Index of Erectile Function 5 questionnaire scores. A significant difference in the incidence of adverse effects between the treatment and control groups was not observed (risk ratio = 0.82, 95% confidence interval: 0.65, 1.05; p = 0.12).

CONCLUSION

Traditional Chinese medicine can gain better responses in improving the International Index of Erectile Function 5 questionnaire scores, clinical recovery rates, and testosterone levels as an alternative and complementary treatment, with no increase in side effects. However, more standardized, long-term, traditional Chinese medicine and integrative therapy clinical trials are needed to support the clinical application of traditional Chinese medicine.

Incretins and microvascular complications of diabetes: neuropathy, nephropathy, retinopathy and microangiopathy

Glucagon-like peptide-1 receptor agonists (GLP-1RAs, incretin mimetics) and dipeptidyl peptidase-4 inhibitors (DPP-4is, incretin enhancers) are glucose-lowering therapies with proven cardiovascular safety, but their effect on microvascular disease is not fully understood. Both therapies increase GLP-1 receptor agonism, which is associated with attenuation of numerous pathological processes that may lead to microvascular benefits, including decreased reactive oxygen species (ROS) production, decreased inflammation and improved vascular function. DPP-4is also increase stromal cell-derived factor-1 (SDF-1), which is associated with neovascularisation and tissue repair. Rodent studies demonstrate several benefits of these agents in the prevention or reversal of nephropathy, retinopathy and neuropathy, but evidence from human populations is less clear. For nephropathy risk in human clinical trials, meta-analyses demonstrate that GLP-1RAs reduce the risk of a composite renal outcome (doubling of serum creatinine, eGFR reduction of 30%, end-stage renal disease or renal death), whereas the benefits of DPP-4is appear to be limited to reductions in the risk of albuminuria. The relationship between GLP-1RAs and retinopathy is less clear. Many large trials and meta-analyses show no effect, but an observed increase in the risk of retinopathy complications with semaglutide therapy (a GLP-1RA) in the SUSTAIN-6 trial warrants caution, particularly in individuals with baseline retinopathy. Similarly, DPP-4is are associated with increased retinopathy risk in both trials and meta-analysis. The association between GLP-1RAs and peripheral neuropathy is unclear due to little trial evidence. For DPP-4is, one trial and several observational studies show a reduced risk of peripheral neuropathy, with others reporting no effect. Evidence in other less-established microvascular outcomes, such as microvascular angina, cerebral small vessel disease, skeletal muscle microvascular disease and autonomic neuropathies (e.g. cardiac autonomic neuropathy, gastroparesis, erectile dysfunction), is sparse. In conclusion, GLP-1RAs are protective against nephropathy, whereas DPP-4is are protective against albuminuria and potentially peripheral neuropathy. Caution is advised with DPP-4is and semaglutide, particularly for patients with background retinopathy, due to increased risk of retinopathy. Well-designed trials powered for microvascular outcomes are needed to clarify associations of incretin therapies and microvascular diseases.

Altered Functional Connectivity of Large-Scale Brain Networks in Psychogenic Erectile Dysfunction Associated with Cognitive Impairments

Purpose

Several studies have demonstrated that psychogenic erectile dysfunction (pED) patients potentially suffer from cognitive dysfunction. Despite that previous neuroimaging studies have reported abnormal functional connections of brain areas associated with cognitive function in pED, the underlying mechanisms of cognitive dysfunction in pED remain elusive. This study aims to investigate the underlying mechanisms of cognitive dysfunction by analyzing large-scale brain networks.

Patients and Methods

A total of 30 patients with pED and 30 matched healthy controls (HCs) were recruited in this study and scanned by resting-state functional magnetic resonance imaging. The Dosenbach Atlas was used to define large-scale networks across the brain. The resting-state functional connectivity (FC) within and between large-scale brain networks was calculated to compare pED patients with HCs. The relationship among cognitive performances and altered FC of large-scale brain networks was further explored in pED patients.

Results

Our results showed that the decreased FC within visual network, and between visual network and default mode network, visual network and frontoparietal network, and ventral attention and default mode network were found in pED patients. Furthermore, there was a positive correlation between immediate memory score and FC within visual network. The visuospatial score was negatively correlated with decreased FC between ventral attention network and default mode network.

Conclusion

Taken together, our findings revealed the relationship between cognitive impairments and altered FC between large-scale brain networks in pED patients, providing the new evidence about the neural mechanisms of cognitive dysfunction in pED patients.

Effect of hypoandrogenism on expression of transient receptor potential vanilloid channels in rat penile corpus cavernosum and erectile function

BACKGROUND

Hypoandrogenism is a cause of erectile dysfunction (ED). Vascular smooth muscle cell contraction and relaxation are regulated by TRPV1-4 channels. However, the influence of hypoandrogenism on TRPV1-4 and its relationship with erectile function remain unclear.

AIM

To reveal whether hypoandrogenism affects erectile function by influencing TRPV1-4 expression in the corpus cavernosum of rats.

METHODS

Male Sprague-Dawley rats (N = 36) aged 8 weeks were assigned to 6 groups at random (n = 6): sham operation, castrated, castrated + testosterone replacement, sham operation + transfection, castrated + transfection, and castrated + empty transfection. Four weeks after castration, 20 μL of lentiviral vector (1 × 108 TU/mL) carrying the TRPV4 gene was injected into the penile cavernous tissue of the transfection groups. One week after transfection, the maximum intracavernous pressure (ICPmax)/mean arterial pressure (MAP) and the content of TRPV1-4, phosphorylated eNOS (p-eNOS)/eNOS, and nitric oxide (NO) in penile cavernous tissue of each group were measured.

OUTCOMES

Under low androgen conditions, TRPV4 expression in endothelial cells in the rat penile cavernosum was sharply reduced, resulting in a decrease in p-eNOS/eNOS and NO content, which could inhibit erectile function.

RESULTS

In rat penile cavernous tissue, TRPV1-4 was expressed in the cell membranes of endothelial cells and smooth muscle cells. The ICPmax/MAP and the content of TRPV4, p-eNOS/eNOS, and NO end product nitrite level in rat penile cavernous tissue was markedly reduced in the castrated group as compared with the sham group (P < .05). The ICPmax/MAP and the content of TRPV4, p-eNOS/eNOS, and NO end product nitrite level in rat penile cavernous tissue were markedly improved in the castrated + transfection group vs the castrated group (P < .01).

CLINICAL IMPLICATIONS

Upregulation of TRPV4 expression in penile cavernosum tissue might be a viable therapeutic for ED caused by hypoandrogenism.

STRENGTHS AND LIMITATIONS

The specific mechanism of TRPV4 in ED needs to be further verified by androgen receptor or TRPV4 gene knockout experiments.

CONCLUSION

Hypoandrogenism may cause ED by reducing the expression of TRPV4 in rat penile cavernous tissue. Upregulation of TRPV4 expression in penile cavernous tissue can increase the ratio of p-eNOS/eNOS and NO levels and ameliorate the erectile function of castrated rats.

Effects of comfort food diet on the penile morphology of stressed rats

Purpose

To investigate the effects of chronic stress, associated or not with comfort food, on the morphology of the penis.

Materials & methods

Thirty-two adult Wistar rats were divided into four experimental groups: Control group (C), receiving standard rat chow, and under normal conditions; Stressed group (S), receiving standard chow, and submitted to stressful situations; Control + comfort food group (C + CF), receiving standard chow and comfort food, and under normal conditions; and Stressed + comfort food group (S + CF), receiving standard chow and comfort food, and submitted to stressful situations. At 10 weeks of age, food supply and stress were initiated. All groups had ad libitum access to standard chow and water, and groups receiving comfort food also had access to Froot Loops®. Chronic stress was induced by restriction, animals were contained daily in polypropylene tubes for 2 h, for eight weeks. After eight weeks all animals were killed; penises were removed for histomorphometric analysis.

Results

Body mass was similar among the groups. Food intake in S + CF group was lower than in other groups. Concerning food preference, groups C + CF and S + CF preferred comfort food over the standard chow, with this preference being higher in S + CF than in C + CF. The area of the corpora cavernosa without tunica albuginea was lower in group S + CF than in group C. Most interestingly, the surface density of connective tissue in the corpora cavernosa was higher in groups S and S + CF compared to group C. In contrast, smooth muscle surface density was markedly lower in S + CF compared to groups C and C + CF, while group S also had reduced smooth muscle in comparison to group C.

Conclusion

Chronic stress caused a morphological alteration on penile histomorphometry. Also, stress increased the preference for comfort foods which caused more deleterious effects in some parameters.

The rs2682826 Polymorphism of the NOS1 Gene Is Associated with the Degree of Disability of Erectile Dysfunction

Erectile dysfunction (ED) is a common male disorder, often associated with cardiovascular disease and ageing. The Sildenafil, a PDE5 inhibitor, can improve the erectile function by prolonging the nitric oxide (NO) downstream effect. NO is a molecule of pivotal importance in erection physiology and is mainly produced by neuronal nitric oxide synthase (nNOS) and endothelial NO synthase (eNOS). While it has been shown that eNOS and nNOS genetic polymorphisms could be associated with Sildenafil responsiveness in ED, no study so far has assessed whether nNOS polymorphisms and PDE5A polymorphism could be associated with increased risk to ED or with intensity of symptoms. A total of 119 ED patients and 114 controls were studied, with evaluation of the clinical disability by the International Index for Erectile Function instrument, plasma assessment of nitrite levels and genomic DNA analysis regarding the rs41279104 and rs2682826 polymorphisms of the NOS1 gene and the rs2389866, rs3733526 and rs13124532 polymorphisms of the PDE5A gene. We have found a significant association of the rs2682826 with lower IIEF scores in the clinical ED group. While this result should be confirmed in other populations, it may be helpful in establishing a genetic panel to better assess disease risk and prognosis on ED therapy.

Lessons learned from the first 15 years of penile transplantation and updates to the Baltimore Criteria

Since 2006, five penis transplants have been performed worldwide. Mixed outcomes have been reported, and two of the five penile transplants have required explantation. However, the long-term outcomes have been encouraging when compliance is implemented, whether standard induction and triple therapy maintenance, or single therapy maintenance. Follow-up monitoring of transplant recipients has enabled a synthesis of technical considerations for surgical success and has shown stable leukocyte counts and renal function after a donor bone-marrow-based immunomodulatory regimen followed by tacrolimus monotherapy as long as 3 years post-transplant, as well as continuous nerve regeneration of penile allografts 3 years post-transplant. Areas of uncertainty include the ethics of donor-recipient colour mismatch, surveillance for sexually transmitted infections and how to optimize patient compliance. Questions also remain with respect to the long-term immunological sequelae of penile tissue, functional outcomes, psychosocial implications and patient selection. Patient counselling should be modified to mention the possibility of long-term improvement in nerve regeneration and sufficient renal function with single-therapy maintenance, and to build a longitudinal dialogue and partnership between the patient and the multidisciplinary care team regarding the risks of sexually transmitted infection instead of surveillance.

Emerging structural and pathological analyses on the erectile organ, corpus cavernous containing sinusoids

Background

The corpus cavernosum (CC) containing sinusoids plays fundamental roles for erection. Analysis of pathological changes in the erectile system is studied by recent experimental systems. Various in vitro models utilizing genital mesenchymal-derived cells and explant culture systems are summarized.

Methods

3D reconstruction of section images of murine CC was created. Ectopic chondrogenesis in aged mouse CC was shown by a gene expression study revealing the prominent expression of Sox9. Various experimental strategies utilizing mesenchyme-derived primary cells and tissue explants are introduced.

Main Findings

Possible roles of Sox9 in chondrogenesis and its regulation by several signals are suggested. The unique character of genital mesenchyme is shown by various analyses of external genitalia (ExG) derived cells and explant cultures. Such strategies are also applied to the analysis of erectile contraction/relaxation responses to many signals and aging process.

Conclusion

Erectile dysfunction (ED) is one of the essential topics for the modern aged society. More comprehensive studies are necessary to reveal the nature of the erectile system by combining multiple cell culture strategies.

Management of male erectile dysfunction: From the past to the future

Erectile dysfunction is a common disease of the male reproductive system, which seriously affects the life quality of patients and their partners. At present, erectile dysfunction is considered as a social-psychological-physiological disease with complex etiology and various treatment methods. Oral PDE5I is the first-line treatment for erectile dysfunction with the advantages of high safety, good effect and non-invasiveness. But intracavernosal injection, hormonal replacement therapy, vacuum erection device, penile prosthesis implantation can also be alternative treatments for patients have organic erectile dysfunction or tolerance to PDE5I. With the rapid development of technologies, some new methods, such as low-intensity extracorporeal shock wave and stem cell injection therapy can even repair the organic damage of the corpora cavernosa. These are important directions for the treatment of male erectile dysfunction in the future. In this mini-review, we will introduce these therapies in detail.

A visualization system for erectile vascular dynamics

Erection is an essential process which requires the male penis for copulation. This copulatory process depends on the vascular dynamic regulation of the penis. The corpus cavernosum (CC) in the upper (dorsal) part of the penis plays a major role in regulating blood flow inside the penis. When the CC is filled with blood, the sinusoids, including micro-vessels, dilate during erection. The CC is an androgen-dependent organ, and various genital abnormalities including erectile dysfunction (ED) are widely known. Previous studies have shown that androgen deprivation by castration results in significantly decreased smooth muscles of the CC. Experimental works in erectile biology have previously measured intracavernosal penile pressure and mechanical tension. Such reports analyze limited features without assessing the dynamic aspects of the erectile process. In the current study, we established a novel explant system enabling direct visual imaging of the sinusoidal lumen to evaluate the dynamic movement of the cavernous space. To analyze the alternation of sinusoidal spaces, micro-dissected CC explants by patent blue dye injection were incubated and examined for their structural alternations during relaxation/contraction. The dynamic process of relaxation/contraction was analyzed with various external factors administered to the CC. The system enabled the imaging of relaxation/contraction of the lumens of the sinusoids and the collagen-containing tissues. Histological analysis on the explant system also showed the relaxation/contraction. Thus, the system mimics the regulatory process of dynamic relaxation/contraction in the erectile response. The current system also enabled evaluating the erectile pathophysiology. In the current study, the lumen of sinusoids relaxed/contracted in castrated mice similarly with normal mice. These results suggested that the dynamic erectile relaxation/contraction process was similarly retained in castrated mice. However, the system also revealed decreased duration time of erection in castrated mice. The current study is expected to promote further understanding of the pathophysiology of ED, which will be useful for new treatments in the future. Hence, the current system provides unique information to investigate the novel regulations of erectile function, which can provide tools for analyzing the pathology of ED.

Intra-cavernosal injection of botulinum toxin in the treatment of erectile dysfunction: a systematic review and meta-analysis

OBJECTIVE

To evaluate the role of botulinum toxin in treating erectile dysfunction as a novel treatment strategy avoiding morbid and irreversible surgeries.

METHODS

A systematic review of literature was conducted from January 1990 through July 31, 2021. Search engines used included PubMed, Embase and Medline databases, to identify studies investigating botulinum toxin in erectile dysfunction, published in English. Seven studies in total were included in our review including two pre-clinical studies. A meta-analysis was performed on three outcomes included commonly in at least two studies. Among the different parameters assessed were, Erection Hardness Score (EHS), Peak Systolic Velocity in cavernosal artery (PSV) and the Sexual Health Inventory for Men (SHIM) score.

RESULTS

A clear benefit was noted for intracavernosal injection (ICI) of botulinum toxin (BoNT-A) on PSV with a mean difference (MD) of 10.82 [4.99, 16.65] and a heterogeneity of I2=61%. EHS results favored BoNT-A as well over placebo with a MD of 0.7 [0.47, 0.93] and a heterogeneity of I2=94%. As for SHIM score, with a heterogeneity of I2=85%, no statistically significant difference was found (MD 0.58 [-0.03, 1.20]).

CONCLUSION

Our review and meta-analysis have shown statistical significance for the benefit of BoNT-A in terms of EHS and PSV. However, this statistical significance should be interpreted in the light of the given limitations: small sample size, heterogeneity in data collection, patient selection bias, and clinical significance of the measured differences. ICI of BoNT-A should currently be limited to clinical studies to further elucidate its clinical benefit.

Impact of atorvastatin on erectile dysfunction: A meta-analysis and systematic review

Atorvastatin may be an effective treatment for erectile dysfunction (ED). The purpose of this meta-analysis was to determine whether atorvastatin therapy is effective in the treatment of ED. All published research on atorvastatin in the treatment of ED patients in EMBASE, PubMed, Web of Science and Cochrane were investigated till 30 October 2021. A meta-analysis of randomized controlled trials (RCTs) was done to investigate the efficacy of atorvastatin and placebo in the treatment of ED. Moreover, we also performed a meta-analysis based on single-arm trials (SATs) to explore the atorvastatin treatment on the efficacy of ED. In a meta-analysis based on RCTs, the weighted mean difference of the change of International Index for Erectile Function-5 (IIEF-5) score in the atorvastatin treatment group with or without treatment was 4.53 (95 per cent confidence interval [CI] of 3.28-5.79) higher than in the control group. In an SAT-based meta-analysis, the ES of the change in IIEF-5 score in the atorvastatin treatment group before and after treatment was 3.22 (95 per cent CI of 1.32-5.12). Atorvastatin is an effective therapeutic drug for patients with ED. However, we expect that more multicentre clinical trials will be conducted to support this assertion.