Techniques and reasons to remain interested in the Y chromosome.
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Abortion, Habitual↗
Biomedical subjects
Jacob Rajfer
Publications and source records attributed to Jacob Rajfer.
Myostatin short interfering hairpin RNA gene transfer increases skeletal muscle mass.
BACKGROUND: Myostatin negatively regulates skeletal muscle growth. Myostatin knockout mice exhibit muscle hypertrophy and decreased interstitial fibrosis. We investigated whether a plasmid expressing a short hairpin interfering RNA (shRNA) against myostatin and transduced using electroporation would increase local skeletal muscle mass. METHODS: Short interfering RNAs (siRNAs) targeting myostatin were co-transfected with a myostatin-expressing plasmid into HEK293 cells and identified for myostatin silencing by Western blot. Corresponding shRNAs were cloned into plasmid shRNA expression vectors. Myostatin or a randomer negative control shRNA plasmid was injected and electroporated into the tibialis anterior or its contralateral muscle, respectively, of nine rats that were sacrificed after 2 weeks. Six other rats received a beta-galactosidase reporter plasmid and were sacrificed at 1, 2, and 4 weeks. Uptake of plasmid was examined by beta-galactosidase expression, whereas myostatin expression was determined by real-time polymerase chain reaction (PCR) and Western blotting. Muscle fiber size was determined by histochemistry. Satellite cell proliferation was determined by PAX7 immunohistochemistry. Myosin heavy chain type II (MHCII) expression was determined by Western blot. RESULTS: beta-Galactosidase reporter plasmid was expressed at 1 and 2 weeks but diminished by 4 weeks in tibialis anterior skeletal muscle. Myostatin shRNA reduced myostatin mRNA and protein expression by 27 and 48%, respectively. Tibialis anterior weight, fiber size, and MHCII increased by 10, 34, and 38%, respectively. Satellite cell number was increased by over 2-fold. CONCLUSIONS: This is the first demonstration that myostatin shRNA gene transfer is a potential strategy to increase muscle mass.
Animals↗
Vardenafil prevents fibrosis and loss of corporal smooth muscle that occurs after bilateral cavernosal nerve resection in the rat.
OBJECTIVES: Impotence, specifically corporal veno-occlusive dysfunction (CVOD), occurs after radical prostatectomy. It results from the effects of cavernosal nerve damage, which causes smooth muscle (SM) loss and an increase in collagen within the corpora. Recent reports have suggested that long-term treatment with phosphodiesterase-5 inhibitors after radical prostatectomy may prevent such changes. We aimed to determine whether bilateral cavernosal nerve resection (BCNX) in the rat leads to CVOD and whether long-term phosphodiesterase-5 inhibition ameliorates these histologic and functional impairments. METHODS: Rats (n = 7 to 11/group) underwent either the sham operation, BCNX, or BCNX plus 30 mg/L vardenafil in the drinking water. Before the rats were killed 45 days later, CVOD was assessed by dynamic infusion cavernosometry. The corpora underwent histochemistry/immunohistochemistry with quantitative image analysis for SM/collagen ratio, collagen III/I ratio, alpha-SM actin, inducible nitric oxide synthase (iNOS), proliferating cell nuclear antigen, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling as a marker of apoptosis. RESULTS: Compared with the sham group, the BCNX rats demonstrated CVOD as measured by the drop rate, a 60% reduction in the SM/collagen ratio, a twofold increase in iNOS expression, and a threefold increase in intracorporeal apoptosis. Compared with the BCNX group, vardenafil increased both iNOS and proliferating cell nuclear antigen expression (SM cell replication), with normalization of the dynamic infusion cavernosometry drop rate and SM/collagen ratio. CONCLUSIONS: Long-term treatment with vardenafil may prevent CVOD after radical prostatectomy by preserving SM content and inhibiting corporal fibrosis possibly by its effect on iNOS.
Animals↗
Effects of long-term vardenafil treatment on the development of fibrotic plaques in a rat model of Peyronie's disease.
OBJECTIVES: To determine whether the phosphodiesterase-5 (PDE5) inhibitor, vardenafil, given orally and in different regimens, has a similar effect to that of the PDE5 inhibitor sildenafil, which prevented the development of a Peyronie's disease (PD)-like plaque formation induced by injecting transforming growth factor beta1 (TGF-beta1) into the tunica albuginea of the rat. MATERIALS AND METHODS: Vardenafil was given to male rats (eight per group) either in the drinking water or as an oral instillation once daily, at approximately 1 and approximately 3 mg/kg/day for 45 days after one injection with TGF-beta1 into the tunica albuginea, as an 'early preventive' treatment for TGF-beta1-induced formation of a PD-like plaque. Other groups received the two doses of vardenafil only in the drinking water, starting with a well-formed plaque, for 42 days ('late, therapeutic' administration). Sections of penile tissue were stained histochemically or immunohistochemically, followed by quantitative image analysis for collagen/smooth muscle and collagen III/I ratios, myofibroblast content (alpha-smooth muscle actin), TGF-beta1 expression, and apoptotic index. RESULTS: Preventative treatment with vardenafil at the higher dose (both continuous and once-daily treatments) reduced the collagen/smooth muscle and collagen III/I ratios, and the numbers of myofibroblasts and TGF-beta1-positive cells, and selectively increased the apoptotic index in the PD-like plaque. The lower dose was less effective, When vardenafil was given continuously in the drinking water for 41 days after the PD-like plaque was formed, there was only a partial reduction of the plaque. CONCLUSIONS: Long-term oral treatment with vardenafil slows and reverses the early stages of an experimental PD-like plaque in the rat, and might ameliorate a more advanced plaque.
Administration, Oral↗
Pioglitazone prevents corporal veno-occlusive dysfunction in a rat model of type 2 diabetes mellitus.
OBJECTIVE: To determine whether corporal veno-occlusive dysfunction (CVOD), corporal smooth muscle (SM) loss, fibrosis and oxidative stress occur in a rat model of type 2 diabetes, and whether these are counteracted by pioglitazone, as pioglitazone is vasculoprotective, and corporal SM is an extension of arterial SM. MATERIALS AND METHODS: Male obese Zucker fa/fa rats were fed chow containing 0%, 0.001% or 0.02% pioglitazone for 2 or 5 months, using untreated lean Zucker and Fischer 344 rats as controls. Functional changes were determined by dynamic-infusion cavernosometry. Histological changes were assessed by histochemistry and immunohistochemistry followed by quantitative image analysis and/or quantitative Western blot. RESULTS: CVOD was detected at 4.5 months of diabetes, accompanied by a lower corporal SM/collagen ratio, and increases in collagen, collagen III/I ratio, apoptotic index, and systemic and tissue oxidative stress. In the short-term treatment, high-dose pioglitazone normalized glycaemia and ameliorated fibrosis and oxidative stress, but induced CVOD, whereas the effects with the low dose were not significant. However, low-dose pioglitazone for 5 months corrected all alterations. CONCLUSION: Type 2 diabetes in Zucker fa/fa rats was associated with penile corporal fibrosis, oxidative stress, and CVOD, which were ameliorated by long-term low-dose pioglitazone, suggesting that this drug might protect the SM, independently from its antidiabetic effect.
Animals↗
Case report: Avoidance of palpable corporal fibrosis due to priapism with upregulators of nitric oxide.
INTRODUCTION: Recent evidence suggests that blocking inducible nitric oxide (NO) synthase in the penis may exacerbate fibrotic processes and that application of medications known to increase NO in tissues may prevent fibrosis. AIM: To report the use of an antifibrotic regimen consisting of medications known to upregulate NO production in two patients with refractory priapism. METHODS: Two patients presented with priapism of greater than 48-hour duration. After corporal aspiration/irrigation and shunting procedures failed, both were prescribed a daily antifibrotic regimen comprising the phosphodiesterase inhibitors pentoxifylline and sildenafil, and the NO precursor, L-arginine. RESULTS: At 1 year, both patients were found to have supple corpora without evidence of corporal fibrosis. CONCLUSIONS: An antifibrotic regimen consisting of upregulators of NO production may ameliorate the corporal fibrosis associated with recalcitrant priapism.
Arginine↗
Phosphodiesterase type 5 is not upregulated by tadalafil in cultures of human penile cells.
OBJECTIVE: Tadalafil, a long-acting phosphodiesterase type 5 (PDE5) inhibitor, improves the erectile response by inhibiting cyclic guanosine monophosphate (cGMP) breakdown. Sustained higher levels of cGMP may hypothetically upregulate PDE5 expression and/or activity and lead to tachyphylaxis. We have investigated whether PDE5 upregulation occurs in vitro in cultures of human penile cells subjected to long-term incubation with increasing concentrations of tadalafil in the presence of a nitric oxide (NO) donor. METHODS: Human corpora cavernosa smooth muscle cells (CSMC) and tunica albuginea fibroblasts (TAF) primary cultures were characterized by immunocytochemistry and Western blot, and incubated with graded concentrations of tadalafil for 14 days, adding S-nitroso-N-acetyl penicillamine (SNAP) as an NO donor for the last 24 hours or at time zero, and cGMP levels were measured. Incubations were repeated for 7, 10, and 14 days, in the presence of SNAP, and PDE5 was estimated by Western blot, and at 14 days, by immunocytochemistry combined with quantitative image analysis, and by real-time reverse transcriptase polymerase chain reaction (RT-PCR). Constructs of the human PDE5A promoter expressing luciferase were cloned and transfected into CSMC, and promoter activation by 8-deoxybromo-cGMP (8-Br-cGMP) was measured by luminometry. RESULTS: Incubations of CSMC with SNAP and tadalafil up to 14 days did not upregulate PDE5 mRNA or protein levels. With TAF, PDE5 protein was also not upregulated despite a slight increase in mRNA levels. PDE5 enzyme activity was unaffected by tadalafil in either CSMC or TAF. No upregulation of the PDE5 promoter was observed with up to 2 mM 8-Br-cGMP. CONCLUSIONS: Long-term incubation of human penile cells with tadalafil at concentrations above the in vitro IC50, and around the in vivo Cmax utilized in the clinical setting, did not upregulate PDE5A expression nor decrease cGMP levels. These data suggest that PDE5 upregulation is unlikely to occur in vivo on long-term tadalafil treatment.
3',5'-Cyclic-GMP Phosphodiesterases↗
Sperm health in the aging male.
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Journal Article↗
Enhancement of sperm motility in assisted reproduction.
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Journal Article↗
TESA or TESE: Which Is Better for Sperm Extraction?
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Journal Article↗
Evidence that osteogenic progenitor cells in the human tunica albuginea may originate from stem cells: implications for peyronie disease.
Tissue ossification in Peyronie disease (commonly known as Peyronie's disease [PD]), a localized fibrotic lesion within the tunica albuginea (TA) of the penis, may result from osteogenic differentiation of fibroblasts, myofibroblasts, and/or adult stem cells in the TA, and may be triggered by chronic inflammation, oxidative stress, and profibrotic factors like transforming growth factor beta 1 (TGFB1). In this study, we have investigated whether cultures of cells from normal TA and PD plaques undergo osteogenesis, express markers for stem cells, and originate other cell lineages via processes modulated by TGFB1. We found that TA and PD cells in osteogenic medium (OM) expressed osteogenic markers, alkaline phosphatase, and osteopontin and underwent calcification. PD cells, but not TA cells, formed foci in soft agar that were positive for alkaline phosphatase and calcification and expressed the mRNAs for osteoblast-specific factors pleiotrophin and periostin and bone morphogenic protein 2. Both cultures expressed stem cell marker CD34 antigen but not protein tyrosine phosphatase, receptor type c. TA and PD cells expressed smooth-muscle cell markers smoothelin and transgelin. None of the cultures underwent adipogenesis in adipogenic medium. Incubation with TGFB1 increased osteogenesis and myofibroblast differentiation and reduced CD34 antigen expression in both cultures. TA and PD cells modulated the differentiation of the multipotent C3H 10T(1/2) cells in dual cultures, into osteoblasts and myofibroblasts. In conclusion, both TA and PD cultures contain cells, presumably stem cells, that undergo osteogenic and myofibroblast differentiation, and may induce these processes by paracrine interactions. This may explain progression of fibrosis in the PD plaque and its eventual calcification.
Adipose Tissue↗
Conservative management options for Peyronie's disease.
Peyronie's disease is an acquired condition that presents clinically with a palpable induration, a distinct plaque, or a curvature of the erect penis. At times, the erections are painful. Erectile dysfunction (ED) often is associated with Peyronie's disease. The current era of phosphodiesterase therapy for the treatment of ED seems to have increased the number of patients presenting for treatment of Peyronie's disease. During the past decade, significant advances have been made in understanding the pathophysiology of the disease, resulting in numerous nonsurgical therapies proposed for the treatment of Peyronie's disease. These medical treatments can be administered systemically, locally, or intralesionally. Unfortunately, there are few randomized, placebo-controlled trials to evaluate most of these proposed therapies. In evaluating therapies for Peyronie's disease, it must be remembered that the natural disease history includes spontaneous resolution of pain and even a small improvement in penile curvature in some men. This article reviews the natural history, scientific understanding, and nonsurgical treatment options for the mild to moderate Peyronie's deformities. Surgical therapy remains the mainstay of treatment for severe and refractory cases of Peyronie's disease that result in a physical or psychologic dysfunction.
Humans↗
Androgen deficiency in the etiology and treatment of erectile dysfunction.
The evaluation and management of erectile dysfunction (ED) has evolved dramatically following the introduction of oral phosphodiesterase-5 inhibitors. Despite the limited role of directed diagnostic testing in the evaluation of the impotent patient, routine de-termination of a serum testosterone likely is indicated based on evidence that testosterone modulates erectile function, that hypogonadism is prevalent among elderly men and men with ED, and that symptomatology alone rarely detects hypogonadism. Forms of testosterone commonly used include oral, parenteral, transdermal, and implantable preparations, each with significant advantages and disadvantages. The risks and benefits of testosterone supplementation have been characterized incompletely and will require further validation before widespread use of testosterone as hormone replacement therapy in aging men.
Adult↗
Peyronie's disease associated with increase in plasminogen activator inhibitor in fibrotic plaque.
OBJECTIVES: To investigate whether tissue expression of plasminogen activator inhibitor type 1 (PAI-1) is increased in the fibrotic plaque of human Peyronie's disease (PD). Increased tissue levels of PAI-1, an inhibitor of both fibrinolysis and collagenolysis, have been found in a variety of fibrotic conditions. Recently, it was reported that PAI-1 expression was also increased in the fibrotic plaque of an animal model of PD induced by the injection of fibrin into the tunica albuginea (TA) of the penis. METHODS: Tissue (n = 10/group) and cells (n = 4/group) obtained from the penile TA plaque of patients with PD or from normal TA were subjected to RNA extraction and real-time reverse transcriptase-polymerase chain reaction. Tissues were also analyzed by immunohistochemistry (n = 8/group) for the detection of PAI-1 expression at the transcription and protein levels. RESULTS: A significant 3.5-fold to 16-fold increase was found in both PAI-1 mRNA and protein levels in the human PD plaque and the respective fibroblast cultures compared with the normal non-PD TA. CONCLUSIONS: The observed increase in PAI-1 in the human PD plaque agrees with what has been observed in the rat and suggests that PAI-1 may be a key pro-fibrotic factor in the development of human PD.
Humans↗
Mechanisms of Disease: new insights into the cellular and molecular pathology of Peyronie's disease.
Peyronie's disease (PD) is characterized by fibrotic plaques in the penile tunica albuginea that cause curvature of the erect penis, and is often accompanied by pain and/or erectile dysfunction. This condition affects up to 9% of men. Treatment is mainly surgical, as pharmacologic therapy has limited efficacy. The pathophysiology of PD is poorly understood, but development of two rat models, extrapolation of what is known about the molecular pathology of other fibrotic conditions, and emphasis on the role of myofibroblasts and adult stem cells are helping to clarify etiology and identify new pharmacologic targets. Recent studies demonstrate a role for oxidative stress and cytokine release-primarily transforming-growth-factor beta1-in development of PD fibrotic plaques. There is evidence indicating that these profibrotic factors interact with antifibrotic defense mechanisms, such as decrease of myofibroblast accumulation, elimination of reactive oxygen species by inducible nitric oxide synthase and neutralization of transforming-growth-factor beta1 by decorin, such that some plaques are in dynamic turnover. Injury to the erect penis is thought to trigger PD by inducing extravasation of fibrin and subsequent synthesis of transforming-growth-factor beta1. Despite the lack of statistical support for a causal association between trauma and PD, it is possible that undetected microtrauma is involved. It is not known whether ossification of PD plaques is linked to fibrosis progression or is a manifestation of an alternative pathway. Both processes seem to be related to activation of fibroblast/myofibroblast differentiation in the tunica albuginea and to osteogenic commitment of stem cells in this tissue.
Disease Progression↗