Adipose tissue-derived stem cells (ADSC) are routinely isolated from the stromal vascular fraction (SVF) of homogenized adipose tissue. Freshly isolated ADSC display surface markers that differ from those of cultured ADSC, but both cell preparations are capable of multipotential differentiation. Recent studies have inferred that these progenitors may reside in a perivascular location where they appeared to co-express CD34 and smooth muscle actin (α–SMA) but not CD31. However, these studies provided only limited histological evidence to support such assertions. In the present study we employed immunohistochemistry and immunofluorescence to define more precisely the location of ADSC within human adipose tissue. Our results show that α–SMA and CD31 localized within smooth muscle and endothelial cells, respectively, in all blood vessels examined. CD34 localized to both the intima (endothelium) and adventitia, neither of which expressed α–SMA. The niche marker Wnt5a was confined exclusively to the vascular wall, within mural smooth muscle cells. Surprisingly, the widely accepted mesenchymal stem cell marker STRO-1 was expressed exclusively in the endothelium of capillaries and arterioles but not in the endothelium of arteries. The embryonic stem cell marker SSEA1 localized to a pericytic location in capillaries and in certain smooth muscle cells of arterioles. Cells expressing the embryonic stem cell markers telomerase and OCT4 were rare and observed only in capillaries. Based on these findings and evidence gathered from the existing literature, we propose that ADSC are vascular precursor (stem) cells at various stages of differentiation. In their native tissue, ADSC at early stages of differentiation can differentiate into tissue-specific cells such as adipocytes. Isolated, ADSC can be induced to differentiate into additional cell types such as osteoblasts and chondrocytes.

Introduction Erectile dysfunction (ED) remains a major complication after radical prostatectomy. The use of adipose tissue-derived stem cells (ADSC) has shown promising results for the treatment of ED. However, the mechanisms of action for stem cell therapy remain controversial, with increasing evidence pointing to paracrine pathways. Aim To determine the effects and to identify the mechanism of action of ADSC and ADSC-derived lysate in a rat model of cavernous nerve (CN) crush injury. Methods Thirty-two male Sprague-Dawley rats were randomly divided into four equal groups: one group underwent sham operation, while three groups underwent bilateral CN crush. Crush-injury groups were treated at the time of injury with intracavernous injection of ADSC, lysate, or vehicle only (injured controls). Erectile function was assessed by cavernous nerve electrostimulation at 4 weeks. Penile tissue was collected for histology. Main Outcome Measures Intracavernous pressure increase upon CN stimulation; neuronal nitric oxide synthase (nNOS) content in the dorsal penile nerve; smooth muscle content, collagen content, and number of apoptotic cells in the corpus cavernosum. Results Both ADSC and lysate treatments resulted in significant recovery of erectile function, as compared to vehicle treatment. nNOS content was preserved in both the ADSC and lysate group, with significantly higher expression compared to vehicle-treated animals. There was significantly less fibrosis and a significant preservation of smooth muscle content in the ADSC and lysate groups compared to injured controls. The observed functional improvement after lysate injection supports the hypothesis that ADSC act through release of intracellular preformed substances or by active secretion of certain biomolecules. The underlying mechanism of recovery appears to involve neuron preservation and cytoprotection by inhibition of apoptosis. Conclusions Penile injection of both ADSC and ADSC-derived lysate can improve recovery of erectile function in a rat model of neurogenic erectile dysfunction.

Background-Effective treatment for stress urinary incontinence (SUI) is lacking. This study investigates whether transplantation of adipose tissue-derived stem cells (ADSCs) can treat SUI in a rat model.

Background Intracavernous (IC) injection of stem cells has been shown to ameliorate cavernous-nerve (CN) injury-induced erectile dysfunction (ED). However, the mechanisms of action of adipose-derived stem cells (ADSC) remain unclear. Objectives To investigate the mechanism of action and fate of IC injected ADSC in a rat model of CN crush injury. Design, setting, and participants Sprague-Dawley rats (n = 110) were randomly divided into five groups. Thirty-five rats underwent sham surgery and IC injection of ADSC (n = 25) or vehicle (n = 10). Another 75 rats underwent bilateral CN crush injury and were treated with vehicle or ADSC injected either IC or in the dorsal penile perineural space. At 1, 3, 7 (n = 5), and 28 d (n = 10) postsurgery, penile tissues and major pelvic ganglia (MPG) were harvested for histology. ADSC were labeled with 5-ethynyl-2-deoxyuridine (EdU) before treatment. Rats in the 28-d groups were examined for erectile function prior to tissue harvest. Measurements IC pressure recording on CN electrostimulation, immunohistochemistry of the penis and the MPG, and number of EdU-positive (EdU+) cells in the injection site and the MPG. Results and limitations IC, but not perineural, injection of ADSC resulted in significantly improved erectile function. Significantly more EdU+ ADSC appeared in the MPG of animals with CN injury and IC injection of ADSC compared with those injected perineurally and those in the sham group. One day after crush injury, stromal cell-derived factor-1 (SDF-1) was upregulated in the MPG, providing an incentive for ADSC recruitment toward the MPG. Neuroregeneration was observed in the group that underwent IC injection of ADSC, and IC ADSC treatment had beneficial effects on the smooth muscle/collagen ratio in the corpus cavernosum. Conclusions CN injury upregulates SDF-1 expression in the MPG and thereby attracts intracavernously injected ADSC. At the MPG, ADSC exert neuroregenerative effects on the cell bodies of injured nerves, resulting in enhanced erectile response.

Introduction Impotence, or erectile dysfunction (ED), is a major complication of type-II diabetes, and many diabetic men with ED are refractory to common ED therapies. Aim To determine whether autologous adipose tissue derived stem cells (ADSC) injected into the penis of impotent obese type-II diabetic rats survive and improve erectile function. Main outcome measures Intracorporal pressure (ICP) increase with cavernous nerve (CN) electrostimulation, immunohistochemistry, real-time PCR, and serum glucose and testosterone assays. Methods Twenty-two 10-week old male fatty type-II diabetic ZDF rats underwent weight and blood glucose measurement every 2 weeks. At age 22 weeks, all animals underwent unilateral CN electrostimulation and ICP measurement to confirm impotence, and paragonadal adipose tissue (5 grams) was harvested and digested to yield 1.5 million ADSC. Impotent animals were randomized to ADSC treatment and sham control groups. At age 23 weeks, treatment group animals underwent penile injection of 1.5 million ADSC; control group animals received only PBS. Erectile function studies were repeated at age 26 weeks, followed by harvest of tissue and serum. Results Pre- and post-treatment stimulation ICP increase was significantly different between groups (p<0.002). In the control group, mean (SD) pre- and post-treatment stimulation ICP increase was 33.8 (15.9) and 31.4 (24.3) cmH2O, respectively, whereas in the treatment group they were 27.4 (14.8) and 65.3 (15.4) cmH2O. BrdU-labeled ADSC were observed within corporal tissue of the treatment group. TUNEL staining (p<0.0001) and caspase-3 m-RNA expression (p<0.05) were significantly higher within corporal tissue of control group versus treatment group animals. Conclusion Autologous ADSCs injected into the penis appear to survive and improve erectile function. Autologous ADSC therapy is a promising approach to treat diabetic impotence.

BACKGROUND Obesity is a risk factor for prostate cancer development, but the underlying mechanism is unknown. The present study tested the hypothesis that stromal cells of the adipose tissue might be recruited by cancer cells to help tumor growth. METHODS PC3 prostate cancer cells were transplanted into the subcutaneous space of the right flank of athymic mice. One week later, adipose tissue-derived stromal or stem cells (ADSC) or phosphate-buffered saline (PBS, as control) was transplanted similarly to the left flank. Tumor size was monitored for the next 34 days; afterwards, the mice were sacrificed and their tumors harvested for histological examination. The ability of PC3 cells to attract ADSC was tested by migration assay. The involvement of the CXCL12/CXCR4 axis was tested by migration assay in the presence of a specific inhibitor AMD3100. RESULTS Throughout the entire course, the average size of PC3 tumors in ADSC-treated mice was larger than in PBS-treated mice. ADSC were identified inside the tumors of ADSC-treated mice; CXCR4 expression was also detected. Migration assay indicated the involvement of the CXCL12/CXCR4 axis in the migration of ADSC toward PC3 cells. Capillary density was twice as high in the tumors of ADSC-treated mice than in the tumors of PBS-treated mice. VEGF expression was similar but FGF2 expression was significantly higher in tumors of ADSC-treated mice than in the tumors of PBS-tread mice. CONCLUSION Prostate cancer cells recruited ADSC by the CXCL12/CXCR4 axis. ADSC helps tumor growth by increasing tumor vascularity, and which was mediated by FGF2.

Introduction Erectile dysfunction (ED) caused by pelvic injuries is a common complication of civil and battlefield trauma with multiple neurovascular factors involved, and no effective therapeutic approach is available. Aims To test the effect and mechanisms of low-energy shock wave (LESW) therapy in a rat ED model induced by pelvic neurovascular injuries. Methods Thirty-two male Sprague-Dawley rats injected with 5-ethynyl-2′-deoxyuridine (EdU) at newborn were divided into 4 groups: sham surgery (Sham), pelvic neurovascular injury by bilateral cavernous nerve injury and internal pudendal bundle injury (PVNI), PVNI treated with LESW at low energy (Low), and PVNI treated with LESW at high energy (High). After LESW treatment, rats underwent erectile function measurement and the tissues were harvested for histologic and molecular study. To examine the effect of LESW on Schwann cells, in vitro studies were conducted. Main Outcome Measurements The intracavernous pressure (ICP) measurement, histological examination, and Western blot (WB) were conducted. Cell cycle, Schwann cell activation-related markers were examined in in vitro experiments. Results LESW treatment improves erectile function in a rat model of pelvic neurovascular injury by leading to angiogenesis, tissue restoration, and nerve generation with more endogenous EdU+ progenitor cells recruited to the damaged area and activation of Schwann cells. LESW facilitates more complete re-innervation of penile tissue with regeneration of neuronal nitric oxide synthase (nNOS)-positive nerves from the MPG to the penis. In vitro experiments demonstrated that LESW has a direct effect on Schwann cell proliferation. Schwann cell activation-related markers including p-Erk1/2 and p75 were upregulated after LESW treatment. Conclusion LESW-induced endogenous progenitor cell recruitment and Schwann cell activation coincides with angiogenesis, tissue, and nerve generation in a rat model of pelvic neurovascular injuries.

Background-Thymidine analog bromodeoxyuridine (5-bromo-2-deoxyuridine, BrdU) has been widely used to label cells in culture and in tissue. The labeled cells can also be tracked when transplanted into a suitable host. In the present study we tested a new thymidine analog 5-ethynyl-2-deoxyuridine (EdU) for labeling and tracking of mesenchymal stem cells (MSC), specifically adipose tissue-derived stem cells (ADSC).