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With the development of medical education,the traditional cell biology teaching modes and methods need constant adjustment to adapt to the current teaching.In view of the present high-speed development of cell biology,we seriously picked some representative themes to carry out thematic teaching.Students were encouraged to read some references about the corresponding content and thought primarily before the class.After the lesson,the teacher guided students to discuss and find the answers to the questions they asked before.Participation in class discussion and homework completion accounted for 10％ of the final assessment results.The thematic teaching helped to optimize classical teaching contents and frontier progress.This teaching mode not only stimulated learning interest but also fully exercised learning ability.
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Cell biology is one of the life science's four basic disciplines.With the rapid development of knowledge,network teaching breaks through the traditional class teaching's limitations,and is significant to constructing innovative teaching modes.In view of the medical undergraduate teaching characteristics,we have summed up the experience of network teaching platform's establishment and application and found that interactive network teaching is helpful to knowledge updating,conducive for students to play a principal role,and beneficial to enhancing the communication between teachers and students.
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Objective To establish a cell culture method for differentiation of keratinocyte in serum free medium mediated by the Ca 2+ concentration. Methods Keratinocytes were cultured in serum and Ca 2+ free keratinocyte growth medium (KGM). Differentiation of keratinocytes was regulated by the change of Ca 2+ concentration in medium, and the expression of K10 and tPA that is elevated in psoriasis were detected by immunocytochemistry (ICC). Results When Ca 2+ concentration in medium was 0.09 mmol/L, keratinocytes were in the state of undifferentiation, K10 expression was negative, and tPA expressed weakly. When cells were exposed to 1.5 mmol/L Ca 2+ medium, terminal differentiation of keratinocyte was induced, K10 expression was positive, and tPA expression was significantly increased. Conclusion The changes of Ca 2+ concentration in mediating the keratinocyte differentiation can be used in the study on keratinocyte differentiation in KGM.
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Objective To explore the annexinⅡexpression in the differentiation of human epidermal keratinocytes. Methods Immunohistochemistry was used to detect annexinⅡexpression in early, middle, late human embryonic skin and adult skin, respectively. Results The expression of annexinⅡ in embryonic epidermis was significantly increased with the development of embryo and annexin Ⅱ expressed much higher in adult epidermis than in embryonic epidermis. Annexin Ⅱ localized in the membrane of keratinocyte, mainly in suprabasal, the more differentiated layers of the epidermis. Conclusion Annexin Ⅱ may be involved in regulating the differentiation of human epidermal keratinocytes.
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Objective To investigate the expression and distribution of fibroblast growth factor-13(FGF-13) in rat vibrissa follicle at anagen and the cultured cells derived from bulge region.Methods FGF-13 expression was detected using immunohistochemistry and immunocytochemistry.Results The in vitro cultured cells from bulge region and the vibrissa follicle expressed FGF-13.In vivo,the cells expressing FGF-13 distributed in the outermost layer of the outer root-sheath(ORS) in the isthmus portion of the follicle.No cells expressing FGF-13 were present in the hair follicle bulb,including matrix cells and ORS.Conclusion In vibrissa follicle at anagen FGF-13 may be involved in the migration of stem cells located at the bulge region to the hair bulb.
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Objective To investigate the regulatory effect of TNF ? on the expression of plasminogen activator inhibitor 2(PAI 2) and its biological significance. Methods Using immunocytochemistry(ICC), terminal deoxynucleotidyl transferase mediated end labeling (TUNEL) and ICC/TUNEL double label methods, the expression of PAI 2 in and the apoptosis of the cultured epidermal keratinocytes treated by TNF ? were detected. Results After the mouse epidermal keratinocytes were incubated with TNF ?, compared with the unshed cells, the expression of PAI 2 in shed cells and the cellular apoptosis increased obviously. The increased PAI 2 expression also appeared in the apoptotic cells, especially in larger and multi angled apoptotic cells. Conclusion In highly differentiated epidermal keratinocytes, TNF ? can enhance the expression of PAI 2 as well as apoptosis. Furthermore, according to the relation with the keratinocytes apoptosis, there are two types of PAI 2 induced by TNF ?, one of which is related to apoptosis, but the other is not.
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Objective To investigate the distribution, isolation and culture of the epidermal stem cells from rats. Methods Immnohistochemical methods were used to confirm the location of the epidermal stem cells. The skin of neonatal rats were dissociated into single cells by dispaseⅡ and trypsin solution,the rapidly adherent cells to collgenⅣ were cultured with KSFM,and those no rapidly adherent cells were regarded as control. Immunohistology and flow cytometry were conducted to identify the epidermal stem cells. Results ? 6-integrin and K15 were expressed in the basal layer cells and hair follicle bulge cells, while the CD71 was negative negatively expressed. CD34 were expressed in the hair follicle bulge cells while not in the basal layer cells. The epidermal stem cells isolated by collgenⅣ had higher colony forming efficiency. Immunocytochemical staining showed that ? 6-integrin and K15 were strongly expressed in the cultured epidermal stem cells. Flow cytometry indicated that 84% cultured epidermal stem cells were expressed ? 6-integrin. Conclusion The epidermal stem cells of rats are located at the basal layer of epidermis and the hair follicle bulge.
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Objective To study the expression changes of?-catenin in the hair follicle before and after GasderminA3 gene mutation.Methods Using SP immunohistochemical staining,RT-PCR,Western blotting to detect the expression of?-catenin in the hair follicle in GSDMa3 mutant and C57BL/6(B6) mice on postnatal 11(anagen) ,16(early catagen) ,18(late catagen) and 24 d(telogen) respectively.Results The expression of?-catenin is gradually weakened from 11 d to 24 d in GSDMa3 mutation mice and B6 mice,but stronger expression was found in GSDMa3 mutation mice than in the B6 mice at different time points.In anagen,?-catenin was expressed in the inner and outer root sheath and hair matrix cells,with stronger expression in GSDMa3 mutant mice than in B6 mice.In catagen,?-catenin was mainly expressed in the outer root sheath and hair matrix cells,with more stronger expression in GSDMa3 mutant mice than in B6 mice.In telogen,?-catenin was expressed in the outer root sheath cells in the mutant mice while little in the hair follicle in B6 mice.Conclusion GSDMa3 gene affects the hair follicle growth and development,probably through regulating the expression of?-catenin.