trichostatin-a and Keloid

Keloids are benign fibrous overgrowths that occur as a result of abnormal wound healing following cutaneous injury. MicroRNAs (miRNAs/miRs) are short non‑coding RNAs that serve critical roles in numerous important biological processes, such as cell proliferation, differentiation and apoptosis. However, their role in keloid development remains largely unknown. In the present study, the role of miR‑30a‑5p, a miRNA regulated by Trichostatin A (TSA), in apoptosis within cultured keloid fibroblasts was investigated. An MTT assay was used to detect the proliferation of cultured keloid fibroblasts treated with TSA. Cell apoptosis and cell cycle phases were analyzed using flow cytometry. In addition, an miRNA microarray was performed to compare expression profiles between cultured keloid fibroblasts treated with or without 1,000 nM TSA. Reverse transcription‑quantitative polymerase chain reaction analysis was conducted to estimate miRNA expression levels. The direct target of miR‑30a‑5p was identified using a dual‑luciferase reporter assay. Western blotting was employed to assess protein expression levels in keloid fibroblasts. The results demonstrated that TSA inhibited the proliferation of keloid fibroblasts in a time‑ and dose‑dependent manner. The miRNA microarray revealed alterations in the expression of numerous miRNA sequences in response to TSA when compared with controls. Notably, the expression of miR‑30a‑5p was downregulated in keloid tissues. In addition, overexpression of miR‑30a‑5p induced apoptosis by targeting B‑cell lymphoma 2, which was similar to that observed in response to TSA. These results provide important information regarding a novel miR‑30a‑5p‑mediated signaling pathway induced by TSA treatment, and suggest a potential use for TSA and miR‑30a‑5p as effective therapeutic strategies for keloids.

Topics: 3' Untranslated Regions; Antagomirs; Apoptosis; Cell Proliferation; Cluster Analysis; Collagen; Epithelial-Mesenchymal Transition; Fibroblasts; G2 Phase Cell Cycle Checkpoints; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Keloid; MicroRNAs; Proto-Oncogene Proteins c-bcl-2; Skin

Keloids are pathological scars characterized by excessive extracellular matrix production that are prone to form in body sites with increased skin tension. CAV1, the principal coat protein of caveolae, has been associated with the regulation of cell mechanics, including cell softening and loss of stiffness sensing ability in NIH3T3 fibroblasts. Although CAV1 is present in low amounts in keloid fibroblasts (KFs), the causal association between CAV1 down-regulation and its aberrant responses to mechanical stimuli remain unclear. In this study, atomic force microscopy showed that KFs were softer than normal fibroblasts with a loss of stiffness sensing. The decrease of CAV1 contributed to the hyperactivation of fibrogenesis-associated RUNX2, a transcription factor germane to osteogenesis/chondrogenesis, and increased migratory ability in KFs. Treatment of KFs with trichostatin A, which increased the acetylation level of histone H3, increased CAV1 and decreased RUNX2 and fibronectin. Trichostatin A treatment also resulted in cell stiffening and decreased migratory ability in KFs. Collectively, these results suggest a role for CAV1 down-regulation in linking the aberrant responsiveness to mechanical stimulation and extracellular matrix accumulation with the progression of keloids, findings that may lead to new developments in the prevention and treatment of keloid scarring.

Topics: Adult; Biopsy; Caveolin 1; Cell Movement; Cells, Cultured; Core Binding Factor Alpha 1 Subunit; Down-Regulation; Female; Fibroblasts; Gene Knockdown Techniques; Humans; Hydroxamic Acids; Keloid; Male; Microscopy, Atomic Force; Middle Aged; Primary Cell Culture; RNA, Small Interfering; Skin; Young Adult

Keloid, a fibro-proliferative benign tumor of skin, is characterized by an enriched milieu of growth factors and an abundant accumulation of extracellular matrix (ECM). Transforming growth factor (TGF)-β1 is well known as the crucial fibrogenic cytokine promoting ECM production and tissue fibrosis in keloid forming. Epigenetic modifications have been shown to play a role in the pathogenesis of cancer as well as autoimmune and inflammatory disorders. Recent publication reports epigenetic modifications in keloid fibroblasts that include an altered pattern of DNA methylation and histone acetylation. Therefore, the field of epigenetics may provide a new therapeutic idea for keloid treatment strategies. Currently, there is some evidence from experimental studies that histone deacetylase (HDAC) inhibitor Trichostatin A (TSA) causes abrogation of TGF-β1 induced collagen synthesis in skin fibroblasts. Furthermore, TSA could suppress proliferation and induce apoptosis in a broad spectrum of tumor cells both in vitro and in vivo. These findings suggest that TSA could also cause abrogation of TGF-β1 induced collagen synthesis and induce apoptosis of proliferating keloid fibroblasts.

Topics: Adolescent; Adult; Apoptosis; Cell Proliferation; Cell Survival; Cells, Cultured; Child; Collagen; Female; Fibroblasts; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Keloid; Male; Transforming Growth Factor beta1; Young Adult

Keloids are benign dermal tumors that form during wound healing in genetically susceptible individuals. The mechanism(s) of keloid formation is unknown and there is no satisfactory treatment. We have reported differences between fibroblasts cultured from normal scars and keloids that include a pattern of glucocorticoid resistance and altered regulation of genes in several signaling pathways associated with fibrosis, including Wnt and IGF/IGF-binding protein 5 (IGFBP5). As previously reported for glucocorticoid resistance, decreased expression of the Wnt inhibitor secreted frizzled-related protein 1 (SFRP1), matrix metalloproteinase 3 (MMP3), and dermatopontin (DPT), and increased expression of IGFBP5 and jagged 1 (JAG1) are seen only in fibroblasts cultured from the keloid nodule. In vivo, decreased expression of SFRP1 and SFRP2 and increased expression of IGFBP5 proteins are observed only in proliferative keloid tissue. There is no consistent difference in the replicative life span of normal and keloid fibroblasts, and the altered response to hydrocortisone (HC) and differential regulation of a subset of genes in standard culture medium are maintained throughout at least 80% of the culture lifetime. Preliminary studies using ChIP-chip analysis, Trichostatin A, and 5-aza-2'-deoxycytidine further support an epigenetically altered program in keloid fibroblasts that includes an altered pattern of DNA methylation and histone acetylation.

Topics: Acetylation; Azacitidine; Black or African American; Cell Division; Cells, Cultured; Culture Media; Decitabine; Dermis; DNA Methylation; Enzyme Inhibitors; Epigenesis, Genetic; Fibroblasts; Fibrosis; Gene Expression Profiling; Gene Silencing; Histone Deacetylase Inhibitors; Histones; Humans; Hydroxamic Acids; Insulin-Like Growth Factor Binding Protein 5; Intercellular Signaling Peptides and Proteins; Keloid; Membrane Proteins; Oligonucleotide Array Sequence Analysis; Wound Healing