title: Stem-cell therapy for erectile dysfunction.
abstract: BACKGROUND
  Erectile dysfunction (ED) is the most common sexual disorder that men report to healthcare providers, and is the male sexual dysfunction that has been most investigated. Current treatments for ED focus on relieving the symptoms of ED and therefore tend to provide a temporary solution rather than a cure or reversing the cause. Recently, therapies based on stem cells (SCs) have had an increasing attention for their potential to restore erectile function. Preclinical studies showed that these cells might reverse the pathophysiological changes leading to ED, rather than treating the symptoms of ED. This review is intended to provide an overview of contemporary reports on the use of SCs to treat ED.
  
  
  METHODS
  We made an extensive search for reports on SC-based therapy for the management of ED, published in English between 1966 and 2013, using the search engines SciVerse-sciencedirect, SciVerse-scopus, Google Scholar and Pubmed, with the search terms 'erectile dysfunction', 'stem cells', 'multipotent stromal cells', 'adipose (tissue) derived stem cells', 'bone-marrow derived stem cells', 'animal model', 'diabetes', 'ageing', 'Peyronie's Disease' and 'cavernous nerve injury'.
  
  
  RESULTS
  Fifty-four papers were identified and contributed, either as an original research report or review thereof, to this review. Several preclinical studies addressed SC-based therapies for the recovery of erectile function caused by a variety of both chronic and acute conditions. Overall, these studies showed beneficial effects of SC therapy, while evidence on the mechanisms of action of SC therapy varied between studies. One clinical trial investigated the short-term effects of SC therapy in diabetic patients with ED. Two more clinical trials are currently recruiting patients.
  
  
  CONCLUSIONS
  The rapidly expanding and highly promising body of preclinical work on SC-based medicine providing a potential cure for ED, rather than merely symptom relief, is indicative of the increasing interest in regenerative options for sexual medicine over the past decade. Clinical trials are currently recruiting patients to test the preclinical results in men with ED.
authors.affiliation: Laboratory for Experimental Urology, Gene and Stem Cells Applications, Department of Development and Regeneration, University of Leuven, Leuven, Belgium.
authors.forename: Maarten
authors.initials: M
authors.lastname: Albersen
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California, San Francisco, CA, USA.
authors.forename: Ching-Shwun
authors.initials: CS
authors.lastname: Lin
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California, San Francisco, CA, USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Lue
keywords: (A)(E)(H)(M) SC, (adult) (embryonic) (haematopoietic) (mesenchymal) stem cell; (e)(n)NOS, (endothelial) (neuronal) NO synthase; AD, adipose tissue-derived; Ageing; BM, bone marrow-derived; CC, corpus cavernosum; CNI, cavernous nerve injury; Cavernous nerve injury; Diabetes; ED, erectile dysfunction; GFP, green fluorescent protein; MD, muscle-derived; MPG, major pelvic ganglion; NO, nitric oxide; PD, Peyronie’s disease; PDE5 (I), phosphodiesterase type 5 (inhibitor); Peyronie’s disease; RP, radical prostatectomy; SVF, stromal vascular fraction