RESUMEN
Forkhead box-O1 (FoxO1) is a key nutrient- and growth factor-dependent regulator of metabolism, but its functional role in human primary keratinocytes (HPKs) is less known. To investigate the role of FoxO1 in HPKs and effect of insulin-like growth factor 1 (IGF-1) and isotretinoin on FoxO1 expression, HPKs were treated with 1.2 mmol/L calcium chloride, 1-20 ng/mL IGF-1 and 0.1-10 µmol/L isotretinoin. Recombinant adenovirus expressing FoxO1 or FKHR shRNA lentivirus transfection was introduced to upregulate or silence FoxO1 expression. Epidermal FoxO1 immunostaining was lower in acne lesion than in normal skin. FoxO1 overexpression induced involucrin expression, G2/M arrest and apoptosis but suppressed proliferation, while FoxO1 silencing decreased involucrin expression but increased proliferation, S phase and viable cells in HPKs. IGF-1 downregulated FoxO1 and involucrin but upregulated p-Akt expression in HPKs, which was blocked by pretreatment with LY294002. Isotretinoin enhanced FoxO1, p53 and p21 but inhibited p-FoxO1 and involucrin expression in HPKs. These results demonstrate that FoxO1 promotes differentiation and apoptosis in HPKs. IGF-1 may reduce keratinocyte differentiation through PI3K/Akt/FoxO1 pathway, while isotretinoin can reinforce FoxO1 expression. FoxO1 may be involved in acne pathogenesis and could serve as a potential therapeutic target.
Asunto(s)
Apoptosis/genética , Puntos de Control del Ciclo Celular/genética , Diferenciación Celular/genética , Proteína Forkhead Box O1/genética , Queratinocitos/fisiología , Acné Vulgar/metabolismo , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/genética , Supervivencia Celular/genética , Células Cultivadas , Cromonas/farmacología , Fármacos Dermatológicos/farmacología , Inhibidores Enzimáticos/farmacología , Proteína Forkhead Box O1/metabolismo , Expresión Génica/efectos de los fármacos , Silenciador del Gen , Humanos , Factor I del Crecimiento Similar a la Insulina/farmacología , Isotretinoína/farmacología , Morfolinas/farmacología , Fosforilación , Cultivo Primario de Células , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Transfección , Proteína p53 Supresora de Tumor/metabolismo , Regulación hacia ArribaRESUMEN
Sebocyte differentiation is a continuous process, but its potential molecular mechanism remains unclear. We aimed to establish a novel sebocyte differentiation model using human primary sebocytes and to identify the expression profiles of differentiation-associated proteins. Primary human sebocytes were cultured on Sebomed medium supplemented with 2% serum for 7 days. Flow cytometry showed that S phase cells were decreased time-dependently, while G1 and subG1 (apoptosis) phase cells increased under serum starvation. Transmission electron microscopy and Oil Red O staining revealed a gradual increase of intracellular lipid accumulation. Expression of proliferation marker was diminished, while expression of differentiation, apoptosis, and lipogenic markers elevated gradually during 7-day culture. iTRAQ analysis identified 3582 expressed proteins in this differentiation model. Compared with day 0, number of differentially expressed proteins was 132, 54, 321, and 96 at days 1, 3, 5, and 7, respectively. Two overexpressed proteins (S100 calcium binding protein P and ferredoxin reductase) and 2 downexpressed proteins (adenosine deaminase and keratin 10) were further confirmed by Western blot and immunohistochemistry.
Asunto(s)
Diferenciación Celular , Células Epiteliales/citología , Modelos Biológicos , Proteoma/metabolismo , Proteómica/métodos , Sebo/citología , Acné Vulgar/patología , Apoptosis , Biomarcadores/metabolismo , Proliferación Celular , Células Cultivadas , Humanos , Lipogénesis , Reproducibilidad de los Resultados , Piel/patologíaRESUMEN
BACKGROUND: The transcription factor Sox9 is pivotal in the morphogenesis of hair follicles, but its role in sebocytes is poorly understood. OBJECTIVE: We investigated the effect of Sox9 on human sebocyte proliferation, differentiation and lipogenesis. METHODS: Sox9 expression was detected by immunohistochemistry in normal skin and acne lesion. Primary cultured human sebocytes were transfected with adenovirus expressing GFP-Sox9 or Sox9 microRNA. Sox9 and peroxisome proliferator-activated receptor (PPAR)γ expression in sebocytes was detected by quantitative real-time PCR, Western blot and immunocytofluorescence; cell proliferation was measured by MTS and [3H]-thymidine incorporation assays; cell cycle distribution and apoptosis were evaluated by propidium iodide staining-based flow cytometry; and intracellular lipid levels were assessed by Oil Red O stain. RESULTS: Sox9 immunostaining was increased in mature sebocytes of acne lesion compared with normal skin. Expression of Sox9 mRNA and protein and PPARγ protein was elevated with cell confluent levels in sebocytes. Sox9 overexpression enhanced proliferation, differentiation, proportion of S and G2/M cells, lipogenesis and PPARγ expression in sebocytes, while Sox9 silencing caused inhibition of differentiation, lipogenesis and PPARγ expression, and increase of G1 and sub-G1 (apoptotic) cell fraction. The suppression of Sox9 knockdown on sebocyte growth was observed using [3H]-thymidine incorporation but not MTS assay. CONCLUSION: These results demonstrate that Sox9 can reinforce sebocyte proliferation, differentiation and lipogenesis. The G1/S transition arrest and apoptotic induction might contribute to inhibitory effect of Sox9 silencing on sebocyte proliferation.