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Mitogen - activated protein kinases (MAPKs), including extracellular signal - regulated kinases (ERKs), c - Jun NH2 - terminal kinases (JNKs) and p38 MAPK, play an important role in transducting environmental stimuli to the transcriptional machinery in the nucleus in mammalian cells by virtue of their ability to phosphorylate and regulate the activity of various transcription factors. It was recently found that the changes in activity of MAPKs occurred during ischemia/reperfusion, but the biological significance of the changes was still controversial.
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AIM: To investigate the effects of intracellular free calcium ([Ca 2+ ]i) from different resources on the proliferation mediated by mitogen activated protein kinase (MAPK) in vascular smooth muscle cells (VSMCs). METHODS: Cultured VSMCs were used in all experiments. Calcium influx was stimulated by angiotension Ⅱ(AngⅡ). The release of intracellular calcium stores was induced by inositol trisphosphate(IP 3) and ryanodine(RY). MAPK activity was measured by [?- 32 P]-ATP incorporation , MAPK protein expression by western blot, VSMCs proliferation by -Leucine(-Leu) and -Thymidine(-TdR) incorporation. RESULTS: Compared to the control VSMCs, AngⅡ, IP 3 and RY significantly increased [Ca 2+ ]i concentration , activity of MAPK and its protein content in VSMCs. The promotion of -Leu and -TdR incorporation in VSMCs was also observed ( P
RESUMEN
Mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinases (ERKs), c-Jun NH2-terminal kinases (JNKs) and p38 MAPK, play an important role in transducting environmental stimuli to the transcriptional machinery in the nucleus in mammalian cells by virtue of their ability to phosphorylate and regulate the activity of various transcription factors. It was recently found that the changes in activity of MAPKs occurred during ischemia/reperfusion, but the biological significance of the changes was still controversial.
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BACKGROUND: The growth of cells is closely related to components in a culture medium. There are many reports about cellular characteristics of melanocytes grown in a PMA-contained medium. However, only a few reports have been studied by using a physiologic mitogens-contained medium. To understand melanocyte in vivo, it is necessary to know the cellular biology of melanocytes grown in a physiologic mitogens-contained medium. OBJECTIVE: To investigate any differences between melanocytes grown in phorbol 12-myristate 13-acetate(PMA)-contained medium and in physiologic mitogens-contained medium. METHOD: We examined morphology, number and melanin contents of cultured human melanocytes grown in a PMA-contained medium and physiologic mitogens-, such as bFGF, ET-1 and a a-MSH contained medium. Result : The results are summarized as follows : 1. There were no significant morphologic differences between cells in PMA-contained medium and in physiologic mitogens-contained medium. 2. The number of melanocytes were significantly more numerous in PMA-contained medium on the 2nd day (p<0.05), but significantly less numerous in the same medium on the 6th day (p<0.05). So, the proliferation rate of melanocytes in PMA-contained medium became lower than in physiologic mitogens-contained medium as time went by. 3. Melanocytes grown in PMA-contained medium had significantly increased melanin contents regardless of the time (p<0.05). Conclusion : The proliferation of melanocytes was better in physiologic mitogens-contained medium, the melanization was higher in melanocytes of PMA-contained medium.
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Humanos , Melaninas , MelanocitosRESUMEN
AIM: To investigate the expression kinetics of PD-L1 and PD-L2 on the surface of the resting and activated B/T cells as well as monocytes from healthy human peripheral blood.METHODS: Fluorescent antibody staining together with flow cytometry were used to detect the percentages of the resting as well as the activated B cells and T cells that expressed PD-L1 and PD-L2.Meanwhile the percentages of the resting and activated monocytes that expressed PD-L2 were determined.RESULTS: Both resting B cells and T cells did not express PD-L1 on their surface,however PD-L1 expression was significantly up-regulated on the surface of the activated B cells after 6 h stimulation with LPS or pokeweed mitogen(PWM),and the percentages of B cells that expressed PD-L1 reached a plateau at 24 h,which were(46.26?10.71)% with LPS and(43.67?6.14)% with PWM stimulation,respectively.No markedly change of PD-L1 expression on the surface of the activated T cells after stimulation with LPS was observed,but upregulation of PD-L1 expression was observed when stimulation with PWM.The percentages of T cells that expressed PD-L1 reached a plateau at 24 h,which was(25.42?9.23)%.PD-L2 expression was not found on the resting as well as the activated B cells and T cells.In addition,the resting monocytes did not express PD-L2.Combination of INF-? plus LPS markedly induced the PD-L2 expression,and the percentages of monocytes that expressed PD-L2 reached a peak at 48 h,which was(28.70?14.22)%.CONCLUSION: The activated lymphocytes only express PD-L1,reaching a plateau at 24 h.PD-L2 is expressed on the surface of the activated monocytes,reaching a peak at 48 h.
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AIM: To observe the effect of adrenomedullin(ADM)on proliferation of vascular smooth muscle cells(VSMC) induced by urotensin Ⅱ(UⅡ). METHODS: DNA synthesis of cultured rat aortic VSMC was measured by -TdR incorporation. The activities of mitogen activated protein kinase(MAPK) were determined by isotope tagged with [?- 32 P]-ATP. RESULTS: UⅡ(10 -8 mol/L) significantly increased -TdR incorporation of VSMC and MAPK activities by 38%( P0.05 ), 32%( P0.05 ), 32%( P
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The effects of methionine-enkephalin (M-EnK) on mitogenic and mixed lymphocyte culture (MLC) proliferation of splenocytes from Zn-deficient, restricted and control mice were evaluated. The data from this experiment showed that M-Enk could suppress the responses of splenocyte from th 3 groups to eoncanavalin A(Con A), but less inhibition was observed in the Zn-deficient group. M-Enk could also enhance the responses to Pokeweed Mitogen (PWM) and decrease the response to Lipopolysaceharide (LPS) in all groups. Alteration of proliferative responses to LPS,Con A and FWM was reversible in the presence of 10 ?mol/L naloxone, indicating that the effect of M-Enk on cellular proliferation was mediated by the opioid receptor. In the proliferation of MLC, the response of lymphocytes from Zndeficient mice was increased in the absence of M-Enk and M-Enk could suppress this increased response. It is therefore concluded that Met-Enk can modify the pattern of mitogenic responses and the alteration in Con A and MLC responses can be influenced by zinc deficiency.
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The effects of pokeweed mitogen (PWM) and esculentoside (Es) in inducing immune interferon (IFN-?) from normal traumatic spleen and patient's spleen cells were studied.The interferon induced was proved to be human immune interferon (HUIFN-?) by determination of its sensitivity to pH 2 and unstabitity at 56℃ as well as neutraliztion by monoclonal antibody to HUIFN-?.The average titres of IFN-?,induced with PWM or Es,from the sphen cells of 10 traumatic pesons were 3.40?0.59 and 2.92?0.42 Log10 CPI50 U/ml respectively,and those from the spleen cells of 8 patients were 3.69?0.35 and 3.01?0.35 LogloCPI50 U/ml respectively.The effec of Es in inducing IFN-Y from either traumatic or patient's spleen cells was lower than that of PWM (P