Practical Approaches to Treat ED in PDE5i Nonresponders

The Association between the Gut Microbiota and Erectile Dysfunction

PURPOSE

Explore the causal relationship between the gut microbiota and erectile dysfunction (ED) at phylum, class, order, family, and genus levels, and identify specific pathogenic bacteria that may be associated with the onset and progression of ED.

MATERIALS AND METHODS

The genetic variation data of 196 human gut microbiota incorporated in our study came from the human gut microbiome Genome Wide Association Studies (GWAS) dataset released by the MiBioGen Consortium. The GWAS statistics for ED were extracted from one study by Bovijn et al., which included 223,805 participants of European ancestry, of whom 6,175 were diagnosed with ED. Subsequently, Mendelian randomization (MR) analysis was carried out to explore whether a causal relationship exists between the gut microbiota and ED. Additionally, bidirectional MR analysis was performed to examine the directionality of the causal relationship.

RESULTS

Through MR analysis, we found that family Lachnospiraceae (odds ratio [OR]: 1.27, 95% confidence interval [CI]: 1.05-1.52, p=0.01) and its subclass genus LachnospiraceaeNC2004 group (OR: 1.17, 95% CI: 1.01-1.37, p=0.04) are associated with a higher risk of ED. In addition, genus Oscillibacter (OR: 1.17, 95% CI: 1.02-1.35, p=0.03), genus Senegalimassilia (OR: 1.32, 95% CI: 1.06-1.64, p=0.01) and genus Tyzzerella3 (OR: 1.14, 95% CI: 1.02-1.27, p=0.02) also increase the risk of ED. In contrast, the inverse variance weighted estimate of genus RuminococcaceaeUCG013 (OR: 0.77, 95% CI: 0.61-0.96, p=0.02) suggests that it has a protective effect against the occurrence of ED.

CONCLUSIONS

This study preliminarily identified 6 bacterial taxa that may have a causal relationship with ED, including family Lachnospiraceae, genus Lachnospiraceae NC2004 group, Oscillibacter, Senegalimassilia, Tyzzerella 3 and Ruminococcaceae UCG013. These identified important bacterial taxa may serve as candidates for microbiome intervention in future ED clinical trials.

Inhibition of multidrug resistance proteins by MK571 restored the erectile function in obese mice through cGMP accumulation

BACKGROUND

Intracellular levels of cyclic nucleotides can also be controlled by the action of multidrug resistance protein types 4 (MRP4) and 5 (MRP5). To date, no studies evaluated the role of their inhibition in an animal model of erectile dysfunction (ED).

OBJECTIVES

To evaluate the effect of a 2-week treatment with MK571, an inhibitor of the efflux of cyclic nucleotides in the ED of obese mice.

MATERIALS AND METHODS

Mice were divided in three groups: (i) lean, (ii) obese, and (iii) obese + MK571. The corpus cavernosum (CC) were isolated, and concentration-response curves to acetylcholine (ACh), sodium nitroprusside (SNP), and tadalafil in addition to electrical field stimulation (EFS) were carried out in phenylephrine pre-contracted tissues. Expression of ABCC4 and ABCC5, intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), the protein levels for pVASP^Ser157 and pVASP^Ser239 , and the intracavernous pressure (ICP) were also determined. The intracellular and extracellular (supernatant) ratios in CC from obese and lean stimulated with a cGMP-increasing substance (BAY 58-2667) in the absence and presence of MK571 (20 μM, 30 min) were also assessed.

RESULTS

The treatment with MK571 completely reversed the lower relaxing responses induced by EFS, ACh, SNP, and tadalafil observed in obese mice CC in comparison with untreated obese mice. Cyclic GMP and p-VASP^Ser239 expression were significantly reduced in CC from obese groups. MK571 promoted a sixfold increase in cGMP without interfering in the protein expression of p-VASP^Ser239 . Neither the cAMP levels nor p-VASP^Ser157 were altered in MK571-treated animals. The ICP was ∼50% lower in obese than in the lean mice; however, the treatment with MK571 fully reversed this response. Expressions of ABCC4 and ABCC5 were not different between groups. The intra/extracellular ratio of cGMP was similar in CC from obese and lean mice stimulated with BAY 58-2667.

CONCLUSIONS

The MRPs inhibition by MK571 favored the accumulation of cGMP in the smooth muscle cells, thus improving the smooth muscle relaxation and the erectile function in obese mice.

Co-overexpression of VEGF and Smad7 improved the therapeutic effects of adipose-derived stem cells on neurogenic erectile dysfunction in the rat model

Cavernous nerve injury is the main cause of erectile dysfunction (ED) after radical prostatectomy (RP). In our previous study, injection of adipose-derived stem cells (ADSCs) into the cavernosum can repair damaged cavernosum nerves and ED can be restored to a certain extent. In order to improve these therapeutic effects, we evaluated the efficacy of ADSCs co-modified with VEGF and Smad7 in a rat model. SD rats were randomly divided into six groups: a sham surgery group, and the five bilateral cavernous nerve injury (BCNI) groups were injected with ADSC or ADSCs genetically modified by VEGF (ADSC-V), Smad7 (ADSC-S), or VEGF&Smad7 (ADSC-V&S) or phosphate-buffered saline (PBS). The results indicated that the erectile function of the ADSC-V, ADSC-S, and ADSC-V&S groups was significantly recovered, and the erectile function of the ADSC-V&S group was more distinctly recovered as compared to the other groups. The same results are shown in the expression of neuronal nitric oxide synthase and the smooth muscle/collagen ratio of penile tissue comparing the ADSC-V&S group to the ADSC-V and ADSC-S group. These experimental data suggest that ADSCs co-overexpressed with VEGF and Smad7 can significantly improve erectile function after BCNI. This study provides new therapeutic thoughts for ED following RP.

miR-195-5p Regulates the Phenotype Switch of CCSM Cells by Targeting Smad7

Introduction

Phenotype switch refers to the process in which smooth muscle cells change from contractile type to synthetic type and acquire the ability of proliferation. Phenotypic transformation involves many changes of cell function, such as collagen deposition and fibrosis, which affect the normal erectile function of penis.

Aim

To investigate the role of miR-195-5p in regulating the Phenotype switch of the corpus cavernosum smooth muscle (CCSM) cells.

Methods

A small mother against decapentaplegic 7(Smad7) virus vector and a miR-195-5p mimics or an si-Smad7 viral vector and a miR-195-5p inhibitor were transfected into CCSM cells. The cells were obtained by primary culture of rat corpus cavernosum smooth muscle tissue. Real-time polymerase chain reaction (PCR) experiments, Western blotting, hematoxylin-eosin (HE) staining, transwell experiments, MTT assays, and flow cytometry were used to detect miR-195-5p, Smad7, phenotype switch markers of CCSM cells and related protein expression, as well as changes in cell morphology, migration, proliferation and apoptosis.

Main Outcome Measure

To study the regulation of miR-195-5p in CCSM cells by overexpression and silencing strategies.

Results

Overexpressed miR-195-5p promoted the transformation of CCSM cells from a contractile type to a synthetic type. Meanwhile, the migration ability and proliferation ability of CCSM cells increased, and the apoptosis rate decreased. The expression-silencing of miR-195-5p gave rise to the opposite effect. The results of the rescue experiment demonstrated that overexpressed Smad7 rescued the inhibitory of the switch of the CCSM cell phenotype from the contractile type to the synthesis type caused by overexpression of miR-195-5p alone. Moreover, the enhancement effect of the migration ability and proliferation ability of CCSM cells was also eliminated, and the apoptosis rate was increased. Silencing miR-195-5p and Smad7 at the same time resulted in the opposite effect.

Conclusion

miR-195-5p may regulate the phenotype switch of CCSM cells by targeting Smad7.

Zhang J, Zhang X, Zhang J, et al. miR-195-5p Regulates the Phenotype Switch of CCSM Cells by Targeting Smad7. Sex Med 2021;9:100349.

Premature Ejaculation, True or False? Clinical evaluation of PE patients with multiple intercourse in one day

Clinical characteristics of 216 adult males previously diagnosed with premature ejaculation (PE) were studied. Using a survey questionnaire, characteristics included intravaginal ejaculation latency time (IELT), penile hardness scores and the refractory period (RP). Ninety-four PE patients reported they had experienced vaginal intercourse more than once (2 to 4 times) in one day (~44%). IELT was significantly increased at the second and subsequent intercourses, and IIEF-15 (International Index of Erectile Function-15) and relevant subclass scores were markedly improved compared to their first intercourse and also compared to the single intercourse group in this cohort study. Overall sexual satisfaction was achieved in the PE patients with multiple intercourse experiences. The same trend was observed in both the patients diagnosed with lifelong and acquired PE. Based on the evidence, the argument is that the PE patients who were diagnosed using their performance at the first intercourse but who have the ability to participate in multiple vaginal intercourses in one day are unlikely to be true PE. The false PE may account for over 40% of PE patients diagnosed by current guidelines and definitions.