RESUMEN
Estrogen dysregulation causes hair disorder. Clinical observations have demonstrated that estrogen raises the telogen/anagen ratio and inhibits hair shaft elongation of female scalp hair follicles. In spite of these clinical insights, the properties of estrogen on hair follicles are poorly dissected. In the present study, we show that estrogen induced apoptosis of precortex cells and caused premature catagen by up-regulation of TGF ß2. Immediately after the premature catagen, the expression of anagen chalone BMP4 increased. The up-regulation of BMP4 may further function to prevent anagen transition and maintain telogen. Interestingly, the hair follicle stem cell niche was not destructed during these drastic structural changes caused by estrogen. Additionally, dermal papilla cells, the estrogen target cells in hair follicles, kept their signature gene expressions as well as their hair inductive potential after estrogen treatment. Retention of the characteristics of both hair follicle stem cells and dermal papilla cells determined the reversibility of the hair cycle suppression. These results indicated that estrogen causes reversible hair cycle retardation by inducing premature catagen and maintaining telogen.
Asunto(s)
Estrógenos/farmacología , Cabello/efectos de los fármacos , Cabello/metabolismo , Animales , Apoptosis/efectos de los fármacos , Proteína Morfogenética Ósea 4/metabolismo , Puntos de Control del Ciclo Celular/efectos de los fármacos , Dermis/efectos de los fármacos , Dermis/metabolismo , Estrógenos/administración & dosificación , Folículo Piloso/efectos de los fármacos , Folículo Piloso/metabolismo , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Masculino , Fenotipo , Transducción de Señal/efectos de los fármacos , Células Madre/efectos de los fármacos , Células Madre/metabolismo , Factor de Crecimiento Transformador beta2/farmacologíaRESUMEN
The skin is susceptible to different injuries and diseases. One major obstacle in skin tissue engineering is how to develop functional three-dimensional (3D) substitute for damaged skin. Previous studies have proved a 3D dynamic simulated microgravity (SMG) culture system as a "stimulatory" environment for the proliferation and differentiation of stem cells. Here, we employed the NASA-approved rotary bioreactor to investigate the proliferation and differentiation of human epidermal stem cells (hEpSCs). hEpSCs were isolated from children foreskins and enriched by collecting epidermal stem cell colonies. Cytodex-3 micro-carriers and hEpSCs were co-cultured in the rotary bioreactor and 6-well dish for 15 days. The result showed that hEpSCs cultured in rotary bioreactor exhibited enhanced proliferation and viability surpassing those cultured in static conditions. Additionally, immunostaining analysis confirmed higher percentage of ki67 positive cells in rotary bioreactor compared with the static culture. In contrast, comparing with static culture, cells in the rotary bioreactor displayed a low expression of involucrin at day 10. Histological analysis revealed that cells cultured in rotary bioreactor aggregated on the micro-carriers and formed multilayer 3D epidermis structures. In conclusion, our research suggests that NASA-approved rotary bioreactor can support the proliferation of hEpSCs and provide a strategy to form multilayer epidermis structure.
Asunto(s)
Reactores Biológicos , Células Madre/citología , Técnicas de Cultivo de Célula , Diferenciación Celular/fisiología , Proliferación Celular , Células Epidérmicas , Epidermis/metabolismo , Técnica del Anticuerpo Fluorescente , Humanos , Integrina beta1/metabolismo , Células Madre/metabolismoRESUMEN
OBJECTIVE: To optimize the conditions of the vacuum belt drying process (VBD) for drying Panax notoginseng extract and compare with methods of vacuum freezing drying and spray drying. METHOD: The optimum conditions of VBD were obtained by orthogonal design and validated by determinations of moisture content of the dried product and recovery of active ingredients. Experiments on different drying methods were also conducted. RESULT AND CONCLUSION: The optimum conditions are as follows, the feeding speed was 15 mL x min(-1), the belt speed was 4 mm x min(-1), and the heating temperature was (105, 100 degrees C). Comparing with the drying methods of vacuum freezing drying and spray drying, vacuum belt drying possesses some advantages, such as higher recovery of active ingredients, less moisture content of dried product and better overall yield.