title: Stem Cell Therapy for Erectile Dysfunction: Progress and Future Directions.
abstract: BACKGROUND
  Erectile dysfunction (ED) is the most common sexual disorder reported by men to their health-care providers and the most investigated male sexual dysfunction. Currently, the treatment of ED focuses on symptomatic relief of ED and therefore tends to provide temporary relief rather than providing a cure or reversing the underlying cause. Recently, stem cell-based therapies have received increasing attention regarding their potential for the recovery of erectile function. Preclinical studies have shown that these cells may reverse pathophysiological changes leading to ED rather than treating the symptom ED.
  
  
  OBJECTIVE
  To review available evidence on the efficacy and mechanisms of action of stem cell application for the treatment of ED.
  
  
  METHODS
  A nonsystematic review was conducted on the available English literature between 1966 and 2013 on the search engines SciVerse-sciencedirect, SciVerse-scopus, Google Scholar, and PubMed.
  
  
  RESULTS
  Several preclinical studies have addressed stem cell-based therapies for the recovery of erectile function following cavernous nerve injury and in Peyronie's disease, diabetes, aging, and hyperlipidemia. Overall, these studies have shown beneficial effects of stem cell therapy, while evidence on the mechanisms of action of stem cell therapy still varies between studies. While many authors propose engraftment and differentiation of stem cells, a recent paradigm shift toward paracrine mechanisms of action is observed. One clinical study investigated stem cell therapy in diabetic patients, and two more clinical trials are currently recruiting patients.
  
  
  CONCLUSIONS
  The development of methods to deliver stem cells to the penis has kindled a keen interest in understanding stem cell biology as it related to restoration of normal penile vascular and neuronal homeostasis. The use of stem cells for the treatment of ED represents an exciting new field, which still requires extensive basic research and human trials in diverse ED patient populations in order to define its role in the treatment of ED. Albersen M, Weyne E, and Bivalacqua TJ. Stem cell therapy for erectile dysfunction: Progress and future directions. Sex Med Rev 2013;1:50-64.
authors: Laboratory for Experimental Urology, Gene and Stem Cells Applications, Department of Development and Regeneration, University of Leuven, Leuven, Belgium. Electronic address: maarten.albersen@uzleuven.be.
authors: Maarten
authors: M
authors: Albersen
authors: Laboratory for Experimental Urology, Gene and Stem Cells Applications, Department of Development and Regeneration, University of Leuven, Leuven, Belgium.
authors: Emmanuel
authors: E
authors: Weyne
authors: The James Buchanan Brady Urological Institute, Department of Urology, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors: Trinity J
authors: TJ
authors: Bivalacqua
keywords: Adipose Tissue‐Derived Stem Cells; Aging; Bone Marrow‐Derived Stem Cells; Cavernous Nerve Injury; Diabetes; Erectile Dysfunction; Peyronie's Disease; Regenerative Medicine; Stromal Vascular Fraction