Third International Conference on the Management of Erectile Dysfunction: Linking Pathophysiology and Therapeutic Response

MicroRNA-145 engineered bone marrow-derived mesenchymal stem cells alleviated erectile dysfunction in aged rats

Background

Aging is one of the dominant factors contributing to erectile dysfunction (ED), and effective treatments for age-associated ED are urgently demanded. In this study, the therapeutic efficiency of bone marrow-derived mesenchymal stem cells (BMSCs) overexpressing microRNA-145 (miR-145) was evaluated in ED.

Methods

Sixty male Sprague-Dawley rats (24 months old) were randomly divided into 4 treatment groups (n = 15/group): PBS (control), BMSCs, BMSCs transfected with a blank vector (vector-BMSCs), and BMSCs transfected with a lentivirus overexpressing miR-145 (OE-miR-145-BMSCs). Fourteen days after transplantation of BMSCs, erectile function was evaluated by measuring intra-cavernous pressure (ICP) and mean arterial pressure (MAP). Subsequently, penile erectile tissues were harvested and subjected to Masson staining, qRT-PCR, immunofluorescence staining, dual luciferase assay, and Western blot analysis.

Results

Fourteen days after transplantation, the ICP/MAP was 0.79 ± 0.05 in the OE-miR-145-BMSC group, 0.61 ± 0.06 in the BMSC group, 0.57 ± 0.06 in the vector-BMSC group, and 0.3 ± 0.01 in the PBS group. Treatment with OE-miR-145-BMSCs significantly improved ED (P < 0.05), and the treatment increased the smooth muscle content in the penis tissues of ED rats (P < 0.05). In the OE-miR-145-BMSC group, the expression levels of α-SMA, desmin, and SM-MHC were higher than they were in the other ED groups (P < 0.05). In addition, the levels of collagen 1, MMP2, and p-Smad2 in the BMSC-treated group, especially in the OE-miR-145-BMSC group, were lower than those in the control group (P < 0.05).

Conclusions

MicroRNA-145 engineered BMSCs effectively attenuate age-related ED. Transplantation of miR-145-overexpressing BMSCs may provide a promising novel avenue for age-associated ED therapy.

The graying of "sexual health": a critical research agenda

This paper critically interrogates the concept of sexual health as it has evolved in relation to older adults. I draw on social and cultural studies of aging, feminist studies, and science and technology studies to outline a research agenda which treats sexual health as a point of articulation for a range of technologies and processes which shape mid- and late-life sexualities. Such an agenda may be able to more fully interrogate the sites and processes by which sexualities are being shaped, the forms of sexual agency on offer to older people, and the contemporary reconstruction of sexual life courses.

Science, medicine and virility surveillance: 'sexy seniors' in the pharmaceutical imagination

Abstract While historically sex has been seen primarily as the prerogative of the young, more recently, the emphasis has been on the maintenance of active sexuality as a marker of successful ageing. A new cultural consensus appears to have emerged which not only emphasises the importance of continued sexual activity across the lifespan, but links sexual function with overall health and encourages increased self-surveillance of, and medical attention to, late-life sexuality. Drawing on historical accounts, clinical research, popular science reporting and health promotion literatures, I explore several key shifts in models of sexual ageing, culminating in the contemporary model of gender, sexuality and ageing that has made ageing populations a key market for biotechnologies aimed at enhancing sexual function. Two central concepts frame my analysis: 'virility surveillance', where age-related changes in sexual function are taken as indicative of decline, and the 'pharmaceutical imagination', where sexual lifecourses are reconstructed as drug effects revise standards of sexual function. After consideration of how narratives emerging from qualitative research with older adults challenge the narrow depiction of sexual functionality promoted by pharmaculture, conclusions call for continued critical inquiry into the biomedical construction of sex and age.

Erectile dysfunction: does insulin resistance play a part?

OBJECTIVE

To review MEDLINE literature for correlations between insulin resistance and erectile dysfunction (ED).

DESIGN

MEDLINE literature review (1966 to present).

SETTING

Academic medical center.

PATIENT(S)

None.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

None.

RESULT(S)

Erectile dysfunction affects more than half of men over the age of 40. Fortunately, most men with ED can be successfully treated with phosphodiesterase 5A (PDE-5) inhibitors, which up-regulate the vasodilatory effects of nitric oxide (NO). Insulin resistance affects 25% of U.S. adults and increases to a 60% occurrence in individuals who are overweight. Endothelial dysfunction, which is associated with insulin resistance states, can cause disturbances in the subcellular signaling pathways required for NO production. Because endothelial production of NO and insulin sensitivity are positively related in healthy humans, the relationships among insulin resistance, NO, and ED are the target of this review of MEDLINE literature.

CONCLUSION(S)

Insulin resistance states are characterized by defective vascular NO production and impaired insulin-induced vasodilation, both of which are likely to cause ED. Diagnosing and treating insulin resistance should be part of the initial management plan for ED. Future studies concerning the cause and effect relationship of insulin resistance and ED should be implemented.

Comparative analysis of the penis corpora cavernosa in controls and patients with erectile dysfunction

OBJECTIVE

To evaluate the presence of structural disorders of the corpora cavernosa in patients with erectile dysfunction (ED), as despite new drugs being effective in many men with ED, some aspects of structural disorders of the corpora cavernosa remain unknown.

MATERIALS AND METHODS

Biopsy specimens were taken from the corpora cavernosa of seven patients (mean age 57.8 years, range 51-72) with severe ED who had a penile prosthesis implanted. The controls tissues were fragments of corpora cavernosa obtained from autopsies of six men (mean age 52.3 years, range 40-66) who died from causes unrelated to the urogenital system. For light microscopy, the specimens were processed routinely to paraffin wax, and by immunohistochemistry to evaluate elastic fibres, and by Masson's trichrome to analyse collagen and smooth muscle fibres. Stereological methods were used to quantitatively evaluate the different elements (as a percentage).

RESULTS

The percentages of the different elements in the human penis of controls and men with ED, respectively, were: elastic fibres 13.2% and 9.1%; collagen fibres 40.8% and 41.6%; and smooth muscle, 40.4% and 42%.

CONCLUSIONS

In patients with ED there was a statistically significant reduction in the percentage of elastic fibres, but no statistically significant difference in collagen and smooth muscle fibres, and no appreciable differences in collagen distribution between the groups.

Gene and stem cell therapy for erectile dysfunction

Erectile dysfunction (ED) is defined as the inability to attain and/or maintain penile erection sufficient for satisfactory sexual performance. ED is a highly prevalent health problem with considerable impact on the quality of life of men and their partners. Although the treatment of ED with oral phosphodiesterase type V (PDE5) inhibitors is effective in a wide range of individuals, it is not efficacious in all patients. The failure of PDE5 inhibitors happens mainly in men with diabetes, non-nerve sparing radical prostatectomy, and high disease severity. Therefore, improved therapies based on a better understanding of the fundamental issues in erectile physiology and pathophysiology have recently been proposed. Here, we summarize studies on ED treatment using gene and stem cell therapies. Adenoviral-mediated intracavernosal transfer of therapeutic genes, such as endothelial nitric oxide synthase (eNOS), calcitonin gene-related peptide (CGRP), superoxide dismutase (SOD), and RhoA/Rho kinase and mesenchymal stem cell-based cell and gene therapy strategy for the treatment of age- and diabetes-related ED are the focus of this review.

Use of combined intracorporal injection and a phosphodiesterase-5 inhibitor therapy for men with a suboptimal response to sildenafil and/or vardenafil monotherapy after radical retropubic prostatectomy

OBJECTIVE

To report experience with combined therapy using intracorporal injection (ICI) of alprostadil and oral phosphodiesterase 5 (PDE-5) inhibitors for the minimally invasive treatment of erectile dysfunction (ED) after radical prostatectomy (RP), as PDE-5 inhibitors are effective but a few patients may have a suboptimal response.

PATIENTS AND METHODS

In a retrospective study, 34 men (aged 46-66 years) had a nerve-sparing retropubic RP and subsequent ED. Patients were titrated on sildenafil citrate or vardenafil to maximum doses. All had a suboptimal response after a maximum of eight doses of oral therapy and were then treated with ICI therapy using 15 or 20 microg alprostadil. Erectile function was assessed with the Sexual Health Inventory for Men (SHIM).

RESULTS

Of the 32 patients who continued combined therapy, 22 (68%) had an improvement in erectile function after ICI therapy, as assessed by the SHIM score. On follow-up, 36% of these patients used ICI therapy only intermittently, instead of regularly, as they felt that this was adequate enough for good results.

CONCLUSIONS

PDE-5 oral pharmacotherapy is the most commonly used effective therapy for ED but may not be as effective in patients who have radical surgery; the addition of testosterone patches may have side-effects or be considered a risk in patients with a history of prostate cancer. The use of ICI therapy as an adjunct or maintenance therapy to their oral medication may be another alternative in these patients.

Methadone Maintenance and Male Sexual Dysfunction

PURPOSE

This study reports the prevalence and types of sexual dysfunction in a sample of men on methadone maintenance for opioid dependence, and describes factors which may contribute to sexual dysfunction.

METHODS

92 opioid-dependent men were recruited from a methadone maintenance clinic and completed two questionnaires, a research interview and laboratory measures.

RESULTS

Fourteen percent reported some sexual dysfunction. Erectile dysfunction (r = 0.24, p = 0.020), libido dysfunction (r = 0.30, p = 0.003), and global dysfunction (r = 0.26, p = 0.013) increased with increasing age of the patient. Methadone dose showed a significant direct correlation with increased orgasm dysfunction, both before and after adjusting for duration of treatment (p = 0.012). None of the sexual dysfunction subscales or global dysfunction were associated with plasma testosterone or plasma prolactin levels.

CONCLUSIONS

The rate of global sexual dysfunction in methadonetreated men is similar to general population studies and should be evaluated using general population guidelines. Orgasm dysfunction is a special case and may respond to methadone dose reduction.

Gene therapy treatments for erectile and bladder dysfunction

The postgenomic age presents many exciting challenges and opportunities for the application of molecular medicine to the treatment of lower urinary tract diseases. Chief among these are the therapeutic possibilities afforded to selectively modulate/alter gene expression in somatic cells to "normalize" aberrant cellular responses to the existing hormonal milieu. In this paper, this therapeutic strategy will be referred to as gene therapy or gene transfer. This article specifically reviews the potential use of gene therapy/transfer to the treatment of bladder and erectile dysfunction. Available treatments for both of these common urologic diseases/disorders have contraindications, untoward side effects, or limited efficacy in certain patient populations. Moreover, that genetic material can be locally administered in the bladder and penis removes a major therapeutic obstacle to the use of gene transfer. Thus far, "proof-of-concept" has been demonstrated in preclinical studies using cellular and molecular strategies on a variety of gene targets. The continuing evolution of gene transfer vectors and gene delivery technologies is expected to further enhance the selectivity, efficacy, and duration of gene therapy, making it a viable treatment option for the amelioration of lower urinary tract diseases/disorders.