目的：研究冬凌草甲素促进U937人淋巴瘤细胞分化的蔬噬细胞吞噬调亡小体的机制。方法：光学显微镜下计数检测吞噬率，PKC活力检测盒测定PKC活力，吖啶橙染色，Hoechst 33258染色及Western blot法。结果：酪氨酸蛋白激酶（PTK）抑制剂genistein和蛋白激酶C（PKC）广泛的抑制剂stauroporine均不同程度地抑制了冬凌草甲素诱导U937分化的蔬噬细胞对调亡小体的吞噬增强效果。2.7umol·L-1的冬凌草甲素处理U937细胞后，时间依赖性地增加了PKC活力。ERK磷酸化抑制剂PD98059阻断了冬凌草甲素的吞噬增强作用。免疫印迹结果显示冬凌草甲素作用U937细胞后，ERK磷酸化程度增加，而PD98059逆转了ERK磷酸化。结论：冬凌草甲素增加U937细胞对凋亡小体的吞噬作用，其吞噬机制是通过激活PTK和PKC激酶，导致下游ERK途径活化，从而增强吞噬过程。

目的：研究科凌草甲素诱导人组织淋巴瘤U937细胞凋亡的机制及ERK激酶在凋亡过程中的作用。方法：噻唑蓝（MTT）法，Hoechst 33258 梁色法，DNA凝胶电泳及Western blot检测法。结果：冬凌草甲素对U937细胞生长抑制作用呈时间剂量依赖性。27umol·L-1冬凌草甲素作用细胞12h后，Hoechst 33258 梁色细胞，出现明显凋亡小体，并诱导ERK发生磷酸化。ERK磷酸化抑制剂PD98059阻断了冬凌草甲素诱导的细胞生长抑制及DNA片段化。细胞内抑制调亡蛋白Bc-XL表达量时间依赖性减少，促调亡蛋白Bax表达量增加，而ERK抑制剂可逆转这种作用。结论：冬凌草甲素（27umol·L-1）诱导U937细胞调亡，这种作用是通过活佛ERK激酶，改变其下游Bax/Bcl-XL的表达比率，从而促进U937的细胞发生调亡

Our previous study showed that oridonin isolated from Rabdosia rubescens enhanced phagocytosis of apoptotic cells by macrophage-like U937 cells through tumor necrosis factor (TNF) α and interleukin (IL)-1β release. In this study, we further investigated signaling events involved in oridonin-augmented phagocytosis. Phagocytic stimulation was significantly suppressed by inhibitors, including a phosphoinositide 3-kinases (PI3K) inhibitor (wortmannin), a protein kinase C (PKC) inhibitor (stauroporine), and a phospholipase C (PLC) inhibitor (U73122). Exposure of U937 cells to oridonin caused an increase in PKC activity timedependently, which was prevented by pretreatment with inhibitors of PI3K and PLC. Simultaneously, the activation of protein kinase B (PKB /Akt) and the increased expression of PLCγ2 were also blocked by wortmannin. In addition, an extracellular signal-regulated kinase (ERK) MAPK inhibitor, PD98059, suppressed oridonin-augmented phagocytosis, whereas the p38 MAPK inhibitor (SB203580) and c-Jun N-terminal kinase (JNK) MAPK inhibitor (SP98059) had no inhibitory effect. Furthermore, pretreatment of U937 cells with anti-TNFα and anti-IL-1β antibodies blocked oridonin-induced phagocytic stimulation as well as phosphorylation of ERK, but did not block the activation of PKC, indicating that these signaling events are triggered by oridonin, whereas secreted TNFα or IL-1β only activate the ERK-dependent pathway. Taken together, oridonin is suggested to enhance phagocytosis of apoptotic bodies by activating PI3K, PKC, and ERK-dependent pathways.

A strain of Aeromonas hydrophila producing copolyesters of 3-hydroxybutyrate and 3-hydroxyhexanoate, abbreviated as PHBHHx, was successfully transformed by electroporation. The plasmid used was a broad host range plasmid pBBR1MCS. Electroporation conditions were varied systemically to develop an electroporation protocol. The optimal yield of transformant was approximately 4£102 CFU/ g DNA at 12.5 kV/cm and 1000, resulting in a time constant of approximately 5ms. The A. hydrophila transformants expressed plasmid-encoded resistance to chloromphenicol. Plasmid DNA in the A. hydrophila transformant was stably maintained. This is the Wrst report of transformation of bacteria A. hydrophila.

We previously reported that oridonin, a major component isolated from the plant Rabdosia rubescens HEMSL, induced apoptosis in human melanoma A375-S2 and cervical cancer HeLa cells. In the present study, oridonin was first evaluated for its effect on phagocytosis of apoptotic cells by macrophages. Preincubation of human histocytic lymphoma U937 cell-derived macrophages with 2.7mM oridonin significantly augmented phagocytosis of UV-irradiated (2.4 J/cm2, 4 min) U937 cells undergoing apoptosis in a dose-and time-dependent manner. However, less effect on synthetic fluoresbrite microspheres indicated that enhancement of apoptotic U937 cell uptake by oridonin was a selective effect. The oridonin-augmented phagocytosis was attenuated by anti-human TNFa and IL-1b antisera, suggesting that TNFa and IL-1b participate in the phagocytosis by oridonin-treated U937 cell-derived macrophages. In addition, the similar effect of phagocytosis was observed in oridonin-treated human monocyte-derived macrophages at 4 d maturation. Taken together, oridonin facilitates the phagocytic activity against apoptotic cells through TNFa and IL-1b release, which may be contribute to its antitumor activities.