The Effect of Epigenetic Therapy on Congenital Neurogenic Bladders—A Pilot Study

Abstract

OBJECTIVES-To demonstrate that human smooth muscle cells derived from neurogenic bladders produce more collagen in vitro than smooth muscle cells derived from normal bladders, and that epigenetic therapy may normalize this increased collagen production.METHODS-Human smooth muscle cells from normal (n = 3) and neurogenic bladders (n = 3) were cultured in normal culture media and at different concentrations of the histone deacetylase inhibitors trichostatin A, valproic acid, and the DNA methylation inhibitor 5-azacytidine (5-aza). Collagen type I and III gene expression was measured using real-time quantitative reverse transcription-polymerase chain reaction after varying doses of drug exposure. Cell viability was measured using trypan blue. RESULTS-The smooth muscle cells from neurogenic bladders released significantly more collagen than the normal bladder cells (mean 4.1 vs 1.8 μg/mL in control media) when grown in normal conditions. Treatment with trichostatin A at 50 ng/mL decreased the collagen level in cells from neurogenic bladders to almost normal levels (2.1 μg/mL). In addition, valproic acid treatment decreased collagen types I and III gene expression relative to controls, with maximal effect at 300 mg/mL. These treatments had little effect on cell viability. CONCLUSIONS-Histone deacetylase inhibitors decreased collagen production of smooth muscle cells from neurogenic bladders in vitro. These agents may be a means of effectively preventing bladder fibrosis in patients with this condition.In children with myelodysplasia, a primary concern is the maintenance of low bladder storage pressure. Elevated intravesical pressure caused by a poorly compliant bladder in patients with spinal dysraphism is associated with damage to the upper urinary tract, and if not appropriately treated, renal failure. 1 Many treatment modalities have been developed to prevent or treat this disease process. One example is the use of chronic oral antimuscarinic therapy from an early age, coupled with clean intermittent catheterization. 2 Intravesical instillation of oxybutynin and other agents also has been attempted. 3,4 However, these therapies vary in efficacy and are associated with a number of side effects. Thus, development of novel treatment options is desirable.Neuropathic bladders have an increased ratio of type-III to type-I collagen, with an absolute increase in the amount of type-III collagen. 5 This increased collagen content is at least in part produced by detrusor smooth muscle cells and is thought to be a major cause of

Phenotypic Switching Induced by Damaged Matrix Is Associated with DNA Methyltransferase 3A (DNMT3A) Activity and Nuclear Localization in Smooth Muscle Cells (SMC)

“…Visceral SMC from neurogenic bladder possess a synthetic phenotype (producing more collagen than normal SMC). This collagen-production has been shown to be inhibited by 5′-aza-deoxycytidine, an inhibitor of DNA methylation [47]. Neurogenic compared to normal bladder SMC also proliferate at a higher rate and continue to express unique expression patterns, even after many passages [48], [49].…”

Epigenetic regulation of smooth muscle cell plasticity

“…The DNA methylation inhibitor, 5-Aza, was shown to partially inhibit collagen type I and III genes in visceral SMC isolated from neurogenic bladders [60]. Furthermore, 5-Aza attenuated PDGF-induced airway SMC migration and proliferation, and was able to increase cellular contractility [61].…”

Inhibition of histone deacetylase 2 mitigates profibrotic TGF-β1 responses in fibroblasts derived from Peyronie's plaque

“…12 Recent studies have demonstrated that HDACs are involved in tissue fibrosis in various organs, including urinary bladder, kidney, liver, heart and lung. 10,13,14 In addition, small-molecule inhibitors of HDAC abrogate the activation and proliferation of fibroblasts in vitro and lessen tissue fibrosis in vivo. 10,13 Although the exact mechanisms by which HDAC mediates fibrotic responses remain largely unknown, HDAC inhibitors are known to repress the TGF-b pathway.…”

“…10,13,14 In addition, small-molecule inhibitors of HDAC abrogate the activation and proliferation of fibroblasts in vitro and lessen tissue fibrosis in vivo. 10,13 Although the exact mechanisms by which HDAC mediates fibrotic responses remain largely unknown, HDAC inhibitors are known to repress the TGF-b pathway. 15 However, none of the currently available HDAC inhibitors is specific for a single isoform of HDAC, which increases toxicity and limits the clinical applications.…”

“…For example, trichostatin A has been known to inhibit fibrotic responses in a variety of animal models or in cell culture systems. 10,13,15,20 However, it was reported that trichostatin A also up-regulates the expression of connective tissue growth factor and intracellular adhesion molecule-1, which are responsible for the pathogenesis of systemic sclerosis. By contrast, silencing of HDAC7 demonstrated an anti-fibrotic effect without influencing the expression of these profibrotic molecules in fibroblasts isolated from patients with systemic sclerosis.…”