MiR-223 regulates proliferation and apoptosis of IL-22-stimulated HaCat human keratinocyte cell lines via the PTEN/Akt pathway.

Psoriasis, a chronic inflammatory skin disorder disease, is closely associated with hyperproliferation of keratinocytes. Upregulated miR-223 has been found in peripheral blood mononuclear cells from patients with psoriasis and from psoriatic skin. However, its role in keratinocytes remains unknown. We thus aimed to investigate the function of miR-223 in psoriasis. Interleukin-22 (IL-22) is a crucial keratinocyte trigger in the T-cell-mediated immune response to psoriasis. We found miR-223 to be overexpressed in psoriatic lesions and in IL-22-stimulated HaCaT cells. HaCaT cells then were transfected with a miR-223 mimic or inhibitor to overexpress or inhibit expression of miR-223, respectively. A Cell Counting Kit-8 assay revealed that miR-223 overexpression promoted and miR-223 downregulation inhibited proliferation in IL-22-stimulated HaCaT cells. Flow cytometry analysis certified that miR-223 overexpression decreased HaCaT cell apoptosis, whereas miR-223 downregulation increased it. A dual-luciferase reporter assay demonstrated that miR-223 directly targeted the phosphatase and tensin homolog (PTEN) gene. MiR-223 also negatively regulated mRNA and protein expression of PTEN and modulated the PTEN/Akt pathway in IL-22-stimulated HaCaT cells. PTEN silencing attenuated the activity of the miR-223 inhibitor in these cells via the PTEN/Akt pathway. Overall, the results showed that miR-223 increased proliferation and inhibited apoptosis of IL-22-stimulated keratinocytes via the PTEN/Akt pathway.

Wang R ，Wang FF ，Cao HW ，Yang JY ... -  《-》

CircRAB3B suppresses proliferation, motility, cell cycle progression and promotes the apoptosis of IL-22-induced keratinocytes depending on the regulation of miR-1228-3p/PTEN axis in psoriasis.

Lu J ，Xu X ，Li Y ，Yu N ，Ding Y ，Shi Y ... -  《-》

MiR-26a inhibits proliferation and migration of HaCaT keratinocytes through regulating PTEN expression.

MicroRNAs (miRNAs) have been shown to be associated with differentiation, migration and apoptosis in keratinocyte. Although it has been reported that microRNA-26a (miR-26a) plays important roles in tumor cells, its biological functions in keratinocytes are still not well elucidated. In this study, we confirmed expression of miR-26a in human keratinocytes using RT-PCR and further studied the role of miR-26a in cell proliferation and cell migration. Ectopic expression of MiR-26a mimic or inhibitor increased or decreased miR-26a expression respectively in HaCaT cells. Proliferation of HaCaT keratinocyte can be suppressed or promoted by overexpression or down-expression of miR-26a. In scratch wound-healing assay and Boyden chamber cell migration assay, upregulating miR-26a expression blocked cell migration, while downregulating miR-26a expression enhanced the migration. Using quantitative RT-PCR (qRT-PCR) and western blot, we further discovered that both mRNA and protein level of phosphatase and tensin homolog deleted from chromosome 10(PTEN) were regulated by miR-26a in HaCaT cells. Meanwhile the level of active form of AKT was also regulated by the miR-26a. In rescue experiment, knockdown of PTEN in the miR-26a mimic transduced cells recovered the migration ability of HaCaT cells. Together these results suggest that miR-26a modulates the proliferation and migration of keratinocytes via regulating PTEN/AKT signaling pathway.

Yu N ，Yang Y ，Li X ，Zhang M ，Huang J ，Wang X ，Long X ... -  《-》

MiR-20a-3p regulates TGF-β1/Survivin pathway to affect keratinocytes proliferation and apoptosis by targeting SFMBT1 in vitro.

Psoriasis is a common immune-mediated chronic inflammatory skin disease characterized by abnormal keratinocyte proliferation, differentiation and apoptosis. However, the exact etiology and pathogenesis are still unclear. Evidence is rapidly accumulating for the role of microRNAs in psoriasis. It has been demonstrated that Interleukin-22 (IL-22) plays vital role in T cell-mediated immune response by interacting with keratinocytes in the pathogenesis of psoriasis. The aim of our study was to explore the possible functional role of miR-20a-3p in psoriasis and in IL-22 induced keratinocyte proliferation. Here, we found that miR-20a-3p was down-regulated in psoriatic lesions and in HaCaT cells (human keratinocyte cell line) treated by IL-22 stimulation. Functional experiments showed that overexpression of miR-20a-3p in HaCaT cells suppressed proliferation and induced apoptosis while its knockdown promoted cell proliferation and reduces cell apoptosis. Mechanistically, SFMBT1 was identified as the direct target of miR-20a-3p by dual luciferase reporter assay. SFMBT1 knockdown was demonstrated to inhibit cell growth and induced apoptosis, which was consistent with the function of miR-20a-3p upregulation in HaCaT cells. In addition, results of western blot analysis showed that miR-20a-3p upregulation or SFMBT1 knockdown changed the protein expression levels of TGF-β1 and survivin. Our findings suggest that miR-20a-3p play roles through targeting SFMBT1 and TGF-β1/Survivin pathway in HaCaT cells, and loss of miR-20a-3p in psoriasis may contribute to hyperproliferation and aberrant apoptosis of keratinocytes.

Li R ，Qiao M ，Zhao X ，Yan J ，Wang X ，Sun Q ... -  《-》

IL-22-induced miR-122-5p promotes keratinocyte proliferation by targeting Sprouty2.

Psoriasis is a common inflammatory skin disease, but the exact pathogenesis is largely unknown. Interleukin-22 (IL-22) has demonstrated its vital role in T-cell-mediated immune response by interacting with keratinocytes in the pathogenesis of psoriasis. Here, we showed the differentially expressed miRNAs and their potential targets in HaCaT cells stimulated by IL-22 using miRNA and mRNA microarrays. We revealed a total of 20 significantly changed (more than twofold) miRNAs in HaCaT cells and validated the results with quantitative reverse transcriptase PCR (qRT-PCR). We demonstrated that miR-122-5p was up-regulated both in HaCaT cells stimulated by IL-22 and in psoriatic lesions. Then, we aimed to investigate the biological roles and potential mechanism of miR-122-5p in keratinocytes. As a result, CCK-8 assay indicated that overexpression of miR-122-5p in keratinocytes promoted proliferation and conversely inhibition of endogenous miR-122-5p suppressed proliferation. According to the microarray analysis, we assumed that Sprouty2 (Spry2), a negative regulator of extracellular signal regulated kinase/mitogen-activated protein kinase signalling pathway, was a direct target gene of miR-122-5p. We found that the staining of Spry2 in cytoplasm was mainly localized in both basal and suprabasal layers of epidermis and showed a markedly decreased expression in psoriasis than in normal control by immunohistochemistry. Luciferase reporter and Western blot assays in HaCaT cells demonstrated that Spry2 was a direct target gene of miR-122-5p. In conclusion, IL-22-induced miR-122-5p promotes keratinocyte proliferation possibly by downregulating the expression of Spry2 thus playing important roles in the pathogenesis of psoriasis.

Jiang M ，Ma W ，Gao Y ，Jia K ，Zhang Y ，Liu H ，Sun Q ... -  《-》