Robert Gelfand

Effect of muscle-derived stem cells on the restoration of corpora cavernosa smooth muscle and erectile function in the aged rat

To determine whether skeletal muscle‐derived stem cells (MDSCs) convert into smooth muscle cells (SMCs) both in vitro and in vivo, and in so doing ameliorate the erectile dysfunction (ED) of aged rats, and whether endogenous stem cells are present in the rat corpora cavernosa.

Profibrotic Role of Myostatin in Peyronie's Disease

INTRODUCTION The primary histologic finding in many urologic disorders, including Peyronies disease (PD), is fibrosis, mainly mediated by the transforming growth factor beta1 (TGFbeta1). AIM To determine whether another member of the TGFbeta family, myostatin, (i) is expressed in the human PD plaque and normal tunica albuginea (TA), their cell cultures, and the TGFbeta1-induced PD lesion in the rat model; (ii) is responsible for myofibroblast generation, collagen deposition, and plaque formation; and (iii) mediates the profibrotic effects of TGFbeta1 in PD. METHODS Human TA and PD tissue sections, and cell cultures from both tissues incubated with myostatin and TGFbeta1 were subjected to immunocytochemistry for myostatin and alpha-smooth muscle actin (ASMA). The cells were assayed by western blot, Real time-Polymerase chain reaction (RT-PCR), and ribonuclease protection. Myostatin cDNA and shRNA were injected, with or without TGFbeta1, in the rat penile TA, and plaque size was estimated by Masson. MAIN OUTCOME MEASURES Myostatin expression in the human TA, the PD plaque, and their cell cultures, and myostatin effects on the PD-like plaque in the rat. RESULTS A threefold overexpression of myostatin was found in the PD plaque as compared with the TA. In PD cells, myostatin expression was mainly in the myofibroblasts, and in the TA cells, it increased upon passage paralleling myofibroblast differentiation and was up-regulated by TGFbeta1. Myostatin or its cDNA construct increased the myofibroblast number and collagen in TA cells. Myostatin was detected in the TGFbeta1-induced PD-like plaque of the rat partly in the myofibroblasts, and in the TA. Myostatin cDNA injected in the TA induced a plaque and intensified the TGFbeta1 lesion, which was not reduced by myostatin shRNA. CONCLUSIONS Myostatin is overexpressed in the PD plaque, partly because of myofibroblast generation. Although myostatin induces a plaque in the rat TA, it does not appear to mediate the one triggered by TGFbeta1, thus suggesting that both proteins act concurrently and that therapy should target their common downstream effectors.

Oral Bisphenol A (BPA) given to rats at moderate doses is associated with erectile dysfunction, cavernosal lipofibrosis and alterations of global gene transcription

Bisphenol A (BPA), a suspected reproductive biohazard and endocrine disruptor, released from plastics is associated with ED in occupationally exposed workers. However, in rats, despite the induction of hypogonadism, apoptosis of the penile corporal smooth muscle (SM), fat infiltration into the cavernosal tissue and changes in global gene expression with the intraperitoneal administration of high dose BPA, ED was not observed. We investigated whether BPA administered orally rather than intraperitoneally to rats for longer periods and lower doses will lead to ED. Main outcome measures are ED, histological, and biochemical markers in rat penile tissues. In all, 2.5-month-old rats were given drinking water daily without and with BPA at 1 and 0.1 mg kg–1 per day. Two months later, erectile function was determined by cavernosometry and electrical field stimulation (EFS) and serum levels of testosterone (T), estradiol (E2) and BPA were measured. Penile tissue sections were assayed by Masson (SM/collagen), Oil Red O (fat), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) (apoptosis), immunohistochemistry for Oct4 (stem cells), and α-SM actin/calponin (SM and myofibroblasts), applying quantitative image analysis. Other markers were assayed by western blotting. DNA microarrays/microRNA (miR) assays defined transcription profiles. Orally administered BPA did not affect body weight, but (1) decreased serum T and E2; (2) reduced the EFS response and increased the drop rate; (3) increased within the corporal tissue the presence of fat, myofibroblasts and apoptosis; (4) lowered the contents of SM and stem cells, but not nerve terminals; and (5) caused alterations in the transcriptional profiles for both mRNA and miRs within the penile shaft. Long-term exposure of rats to oral BPA caused a moderate corporal veno-occlusive dysfunction (CVOD), possibly due to alterations within the corporal tissue that pose gene transcriptional changes related to inflammation, fibrosis and epithelial/mesenchymal transition (EMT).

Myostatin genetic inactivation inhibits myogenesis by muscle-derived stem cells in vitro but not when implanted in the mdx mouse muscle

IntroductionStimulating the commitment of implanted dystrophin+ muscle-derived stem cells (MDSCs) into myogenic, as opposed to lipofibrogenic lineages, is a promising therapeutic strategy for Duchenne muscular dystrophy (DMD).MethodsTo examine whether counteracting myostatin, a negative regulator of muscle mass and a pro-lipofibrotic factor, would help this process, we compared the in vitro myogenic and fibrogenic capacity of MDSCs from wild-type (WT) and myostatin knockout (Mst KO) mice under various modulators, the expression of key stem cell and myogenic genes, and the capacity of these MDSCs to repair the injured gastrocnemius in aged dystrophic mdx mice with exacerbated lipofibrosis.ResultsSurprisingly, the potent in vitro myotube formation by WT MDSCs was refractory to modulators of myostatin expression or activity, and the Mst KO MDSCs failed to form myotubes under various conditions, despite both MDSC expressing Oct 4 and various stem cell genes and differentiating into nonmyogenic lineages. The genetic inactivation of myostatin in MDSCs was associated with silencing of critical genes for early myogenesis (Actc1, Acta1, and MyoD). WT MDSCs implanted into the injured gastrocnemius of aged mdx mice significantly improved myofiber repair and reduced fat deposition and, to a lesser extent, fibrosis. In contrast to their in vitro behavior, Mst KO MDSCs in vivo also significantly improved myofiber repair, but had few effects on lipofibrotic degeneration.ConclusionsAlthough WT MDSCs are very myogenic in culture and stimulate muscle repair after injury in the aged mdx mouse, myostatin genetic inactivation blocks myotube formation in vitro, but the myogenic capacity is recovered in vivo under the influence of the myostatin+ host-tissue environment, presumably by reactivation of key genes originally silenced in the Mst KO MDSCs.

The Transcriptional Signatures of Cells from the Human Peyronie's Disease Plaque and the Ability of These Cells to Generate a Plaque in a Rat Model Suggest Potential Therapeutic Targets

INTRODUCTION The success of medical therapies for Peyronies disease (PD) has not been optimal, possibly because many of them went directly to clinical application without sufficient preclinical scientific research. Previous studies revealed cellular and molecular pathways involved in the formation of the PD plaque and in particular the role of the myofibroblast. AIMS The current work aimed to determine under normal and fibrotic conditions what differentiates PD cells from tunica albuginea (TA) and corpora cavernosa (CC) cells by defining their global transcriptional signatures and testing in vivo whether PD cells can generate a PD-like plaque. METHODS Human TA, PD, and CC cells were grown with transforming growth factor beta 1 (TGFβ1; TA+, PD+, CC+) or without it (TA-, PD-, CC-) and assayed by (i) immunofluorescence, Western blot and RT-PCR for myofibroblast, smooth muscle cell and stem cell markers; (ii) collagen content; and (iii) DNA microarray analysis. The ability of PD+ cells to induce a PD-like plaque in an immuno-suppressed rat model was assessed by Masson trichrome and Picrosirius Red stainings. MAIN OUTCOMES MEASURES Fibroproliferative features of PD cells and identification of related key genes as novel targets to reduce plaque size. RESULTS Upon TGFβ1stimulation, collagen levels were increased by myofibroblasts in the PD+ but not in the CC+ cells. The transcriptional signature of the PD- cells identified fibroproliferative, myogenic (myofibroblasts), inflammatory, and collagen turnover genes that differentiate them from TA- or CC- cells and respond to TGFβ1 with a PD+ fibrotic phenotype, by upregulation of IGF-1, ACTG2, MYF5, ACTC1, PSTN, COL III, MMP3, and others. The PD+ cells injected into the TA of the rat induce a PD-like plaque. CONCLUSIONS This suggests a novel combination therapy to eliminate a PD plaque by targeting the identified genes to (i) improve collagenase action by stimulating endogenous metalloproteinases specific to key collagen types and (ii) counteract fibromatosis by inhibiting myofibroblast generation, proliferation, and/or apoptosis.

Long-term exposure of MCF-12A normal human breast epithelial cells to ethanol induces epithelial mesenchymal transition and oncogenic features

Alcoholism is associated with breast cancer incidence and progression, and moderate chronic consumption of ethanol is a risk factor. The mechanisms involved in alcohols oncogenic effects are unknown, but it has been speculated that they may be mediated by acetaldehyde. We used the immortalized normal human epithelial breast cell line MCF-12A to determine whether short- or long-term exposure to ethanol or to acetaldehyde, using in vivo compatible ethanol concentrations, induces their oncogenic transformation and/or the acquisition of epithelial mesenchymal transition (EMT). Cultures of MCF-12A cells were incubated with 25 mM ethanol or 2.5 mM acetaldehyde for 1 week, or with lower concentrations (1.0–2.5 mM for ethanol, 1.0 mM for acetaldehyde) for 4 weeks. In the 4-week incubation, cells were also tested for anchorage-independence, including isolation of soft agar selected cells (SASC) from the 2.5 mM ethanol incubations. Cells were analyzed by immunocytofluorescence, flow cytometry, western blotting, DNA microarrays, RT/PCR, and assays for miRs. We found that short-term exposure to ethanol, but not, in general, to acetaldehyde, was associated with transcriptional upregulation of the metallothionein family genes, alcohol metabolism genes, and genes suggesting the initiation of EMT, but without related phenotypic changes. Long-term exposure to the lower concentrations of ethanol or acetaldehyde induced frank EMT changes in the monolayer cultures and in SASC as demonstrated by changes in cellular phenotype, mRNA expression, and microRNA expression. This suggests that low concentrations of ethanol, with little or no mediation by acetaldehyde, induce EMT and some traits of oncogenic transformation such as anchorage-independence in normal breast epithelial cells.

Long-term exposure of MCF-7 breast cancer cells to ethanol stimulates oncogenic features

Alcohol consumption is a risk factor for breast cancer. Little is known regarding the mechanism, although it is assumed that acetaldehyde or estrogen mediated pathways play a role. We previously showed that long-term exposure to 2.5 mM ethanol (blood alcohol ~0.012%) of MCF-12A, a human normal epithelial breast cell line, induced epithelial mesenchymal transition (EMT) and oncogenic transformation. In this study, we investigated in the human breast cancer cell line MCF-7, whether a similar exposure to ethanol at concentrations ranging up to peak blood levels in heavy drinkers would increase malignant progression. Short-term (1-week) incubation to ethanol at as low as 1–5 mM (corresponding to blood alcohol concentration of ~0.0048–0.024%) upregulated the stem cell related proteins Oct4 and Nanog, but they were reduced after exposure at 25 mM. Long-term (4-week) exposure to 25 mM ethanol upregulated the Oct4 and Nanog proteins, as well as the malignancy marker Ceacam6. DNA microarray analysis in cells exposed for 1 week showed upregulated expression of metallothionein genes, particularly MT1X. Long-term exposure upregulated expression of some malignancy related genes (STEAP4, SERPINA3, SAMD9, GDF15, KRT15, ITGB6, TP63, and PGR, as well as the CEACAM, interferon related, and HLA gene families). Some of these findings were validated by RT-PCR. A similar treatment also modulated numerous microRNAs (miRs) including one regulator of Oct4 as well as miRs involved in oncogenesis and/or malignancy, with only a few estrogen-induced miRs. Long-term 25 mM ethanol also induced a 5.6-fold upregulation of anchorage-independent growth, an indicator of malignant-like features. Exposure to acetaldehyde resulted in little or no effect comparable to that of ethanol. The previously shown alcohol induction of oncogenic transformation of normal breast cells is now complemented by the current results suggesting alcohols potential involvement in malignant progression of breast cancer.

Chronic high dose intraperitoneal bisphenol A (BPA) induces substantial histological and gene expression alterations in rat penile tissue without impairing erectile function.

INTRODUCTION Bisphenol A (BPA), released from plastics and dental sealants, is a suspected endocrine disruptor and reproductive toxicant. In occupationally exposed workers, BPA has been associated with erectile dysfunction (ED). AIMS To determine whether long-term exposure to high doses of BPA in the rat affects serum levels of testosterone (T) and estradiol (E2), and induces corporal histopathology and resultant ED. METHODS Young rats were injected intraperitoneal (IP) injection daily with BPA at 25 mg/kg/day or vehicle (n = 8/group). Erectile function was measured at 3 months by cavernosometry and electrical field stimulation (EFS). BPA was assayed in serum, urine, and penile tissue, and serum T and E2 were determined. Quantitative Masson trichrome, terminal deoxynucleotidyl transferase dUTP nick end labeling, Oil Red O, immunohistochemistry for calponin, α-smooth muscle actin, and Oct 4 were applied to penile tissue sections. Protein markers were assessed by Western blots and 2-D minigels, and RNA by DNA microarrays. MAIN OUTCOME MEASURES Erectile function, histological, and biochemical markers in corporal tissue. RESULTS In the BPA-treated rats, total and free BPA levels were increased in the serum, urine, and penile tissue while serum T and E2 levels were reduced. In addition, the corpora cavernosa demonstrated a reduction in smooth muscle (SM) content, SM/collagen ratio, together with an increase in myofibroblasts, fat deposits, and apoptosis, but no significant change in collagen content or stem cells (nuclear/perinuclear Oct 4). In the penile shaft, BPA induced a downregulation of Nanog (stem cells), neuronal nitric oxide synthase (nitrergic terminals), and vascular endothelial growth factor (angiogenesis), with genes related to SM tone and cytoskeleton upregulated 5- to 50-fold, accompanied by changes in the multiple protein profile. However, both cavernosometry and EFS were unaltered by BPA. CONCLUSIONS While rats treated chronically with a high IP dose of BPA developed hypogonadism and a corporal histo- and molecular-pathology usually associated with ED, no changes were detected in erectile function as measured by EFS and cavernosometry. Further studies using alternate routes of BPA administration with various doses and length of exposure are needed to expand these findings.

Abstract 5559: Long-term exposure of breast cell lines to ethanol affects the transcriptional signature for some oncogenic gene families, but has little effect on this phenotype in mammospheres or on the expression of stem cell markers

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Objectives. Chronic alcoholism is a risk factor for breast cancer but the mechanism of its potential oncogenic effects is unknown. Stem cells have been found in the epithelium of normal breast tissue and are postulated to convert into cancer stem cells driving tumor generation and metastasis. Breast stem cells are assumed to be enriched within multiple-cell spheroids named mammospheres. Here we aimed to determine whether ethanol, or its metabolite, acetaldehyde, stimulate the in vitro proliferation and malignant transformation of human breast stem cells within epithelial cell cultures and mammospheres, and whether this process is defined by specific gene expression signatures denoting oncogenesis, stemness and/or alcohol-regulation. Methods. Cultures of monolayer attached cells and mammospheres from MCF-12 (“normal”) and MCF-7 (“malignant”) cell lines were incubated +/- 25 mM ethanol and subjected to DNA microarray analysis, or in triplicate with increasing concentrations of ethanol (0-25 mM) or acetaldehyde (0-12.5 mM) for 6 days, followed by immunocytofluorescence, quantitative western blot for stem cell markers Oct4 and nanog, and by RT-PCR, the formazan assay and growth in soft agar. Results. Low levels of mRNAs for stem cell markers were seen by DNA microarrays in all cultures, but except for Sox4 and Jag1 were not responsive to ethanol. Oct4 and nanog proteins were detected in the nuclei of MCF-7 attached cells, and expressed respectively as 45 (Oct4a) and 38 kDa bands for the active isoforms, whereas in MCF-12 attached cells they were detected as the variant 33 (Oct4b) and 55 kDa proteins. Ethanol reduced Oct4a moderately in MCF-7 attached cells and acetaldehyde increased it, but no changes occurred in mammospheres. Ethanol increased Oct4b and reduced nanog in MCF-12 attached cells, with no change (Oct4) or an increase (nanog) in mammospheres. In both MCF-7 and MCF-12 attached cells, but not in mammospheres, ethanol upregulated by >2 several alcohol-responsive metallothioneins (mainly 1F, 1X, and 2A), and related trans-membrane proteases serine (TMPRSS), as well as centromer-associated protein and PAI 1, while reducing other serpines and caspase 4, all malignancy-associated genes. Conclusions. Although stem cell markers were expressed in MCF-7 and MCF-12 attached cells, they were not increased in mammospheres, raising doubts about the putative stem cell enrichment in these spheroids. The inconsistent modulation of stem cell number by ethanol and acetaldehyde requires confirmation by cell sorting. The identification of several ethanol-responsive, malignancy-associated genes in both MCF-7 and MCF-12 attached cells may support an oncogenic risk for high alcohol levels. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5559. doi:10.1158/1538-7445.AM2011-5559

Myostatin, a profibrotic factor and the main inhibitor of striated muscle mass, is present in the penile and vascular smooth muscle

Myostatin is present in striated myofibers but, except for myometrial cells, has not been reported within smooth muscle cells (SMC). We investigated in the rat whether myostatin is present in SMC within the penis and the vascular wall and, if so, whether it is transcriptionally expressed and associated with the loss of corporal SMC occurring in certain forms of erectile dysfunction (ED). Myostatin protein was detected by immunohistochemistry/fluorescence and western blots in the perineal striated muscles, and also in the SMC of the penile corpora, arteries and veins, and aorta. Myostatin was found in corporal SMC cultures, and its transcriptional expression (and its receptor) was shown there by DNA microarrays. Myostatin protein was measured by western blots in the penile shaft of rats subjected to bilateral cavernosal nerve resection (BCNR), that were left untreated, or treated (45 days) with muscle-derived stem cells (MDSC), or concurrent daily low-dose sildenafil. Myostatin was not increased by BCNR (compared with sham operated animals), but over expressed after treatment with MDSC. This was reduced by concurrent sildenafil. The presence of myostatin in corporal and vascular SMC, and its overexpression in the corpora by MDSC therapy, may have relevance for the stem cell treatment of corporal fibrosis and ED.