共查询到20条相似文献,搜索用时 109 毫秒
1.
目的研究乳酸杆菌DM9811发酵滤液中存在的100200 bp长的RNA片段(Ls-RNA)的免疫调节与抗肿瘤作用。方法采用中性红吞噬试验检测巨噬细胞吞噬功能,用L929细胞检测TNF,用免疫保护试验检测体内抗肿瘤作用。结果Ls-RNA可增强脾巨噬细胞的吞噬活性,对小鼠肝癌Hca-F的生长有抑制作用,延长小鼠的存活时间,但对TG诱导的腹腔巨噬细胞产生TNF无明显调节作用。结论Ls-RNA有一定免疫调节和抗肿瘤作用。 相似文献
2.
3.
本文研究了小鼠腹腔巨噬细胞极低密度脂蛋白(VLDL)受体的调节。用富含甘油三酯(TG)的VLDL与小鼠巨噬细胞预温育后,细胞结合~(125)I-VLDL的最大结合容量(Bmax)比对照细胞只降低5%(1071/1127ng/mg细胞蛋白质),当细胞内TG增加到对照的2.5倍时,细胞摄取及降解~(125)I-VLDL的量分别下降40%和22%;乙酰-低密度脂蛋白(AC-LDL)预温育的细胞结合~(125)I-VLDL的Bmax比对照细胞只降低14%(633/831ng/mg细胞蛋白质),当细胞内胆固醇(Ch)增加到对照的23倍时,细胞摄取及降解~(125)I-VLDL的量只分别下降10%和21%。此后随着细胞内TG或Ch含量的增加,摄取及降解~(125)I-VLDL的量仍保持不变。 结论:细胞内TG或Ch含量对VLDL受体的调节作用微弱,与TG相比,Ch的调节作用更弱。 相似文献
4.
此次研究旨在探讨猫爪草多糖对体外培养的正常状态下的原代小鼠腹腔巨噬细胞活性的调节作用,以及小鼠腹腔巨噬细胞在体外培养条件下的活力变化情况。以原代培养的小鼠腹腔巨噬细胞为研究对象,设对照组(加入100μL DMEM培养基)和实验组(分别加入25μg/mL, 50μg/mL, 100μg/mL, 200μg/mL,400μg/mL的猫爪草多糖),分别采用噻唑蓝(MTT)比色法、CCK-8法、乳酸脱氢酶释放法和中性红吞噬实验检测不同浓度的猫爪草多糖对体外培养的小鼠腹腔巨噬细胞活力的调节作用;同时设置24 h、36 h、48 h、60 h和72 h的不同培养时间,观察在体外培养条件下,小鼠腹腔巨噬细胞活力的变化情况。结果表明:与对照组相比,不同浓度的猫爪草多糖均能增强小鼠腹腔巨噬细胞的活力,且猫爪草多糖浓度在100~400μg/mL的细胞活力极显著增强(p<0.01)。此外,各处理组的巨噬细胞在体外培养24~72 h不更换培养液的条件下,48 h处活性最佳。体外培养条件下,一定浓度的猫爪草多糖可以激活小鼠腹腔巨噬细胞,通过猫爪草多糖激活巨噬细胞,可能是猫爪草发挥提升机体免疫力的作用机制之一。此外,体外培养的巨噬细胞虽能存活长达一个月,但仍有一个最佳活力时间。 相似文献
5.
雪莲对正常及辐射损伤小鼠巨噬细胞功能的影响 总被引:2,自引:0,他引:2
本文研究了50%雪莲水煎剂对正常及5GY60Co一次性全身照射BALB/C小鼠巨噬细胞功能的影响,结果表明:口服50%雪莲水煎剂能增强巨噬细胞吞噬鸡血球及分泌肿瘤坏死因子(TNF)的能力,与相应对照组比较具有显著性差异,提示中药雪莲具有扶正固本提高机体防御机能及促进辐射损伤修复的作用。为该药的临床应用提供了科学依据。 相似文献
6.
7.
巨噬细胞迁移抑制因子(macrophage migration inhibitory factor, MIF)是一类多效性的前炎症细胞因子,能够促进其他多种前炎症因子的分泌或表达。其基因在大多数哺乳动物基因组中具有90%的同源性。MIF启动子区含有能够与多种转录因子结合的DNA结合位点,同时含有与其表达水平相关的多态性位点。MIF发挥其生物学功能,一方面可以通过非受体介导的内吞作用,实现MIF与c-Jun激活结构域结合蛋白-1(JAB1)的相互作用;另一方面,受体依赖型的MIF能够激活包括PI3K/AKT、MAPK和G蛋白偶联受体相关的信号传导途径等。此外,MIF还能够通过直接或间接方式调节肿瘤抑制基因p53的功能。MIF已经被证实参与调解炎症、肿瘤生成和纤维化等生物学过程。从MIF表达、相关受体、涉及的信号通路与生物学过程等方面,对其分子功能的研究进展进行了总结,并对MIF相关的分子机理进行了综述,旨在为MIF相关疾病的诊断和治疗提供线索。 相似文献
8.
双歧杆菌对裸鼠腹腔巨噬细胞NO形成的调节作用 总被引:2,自引:1,他引:2
给裸小鼠腹腔注射青春型双歧杆菌,每天一次,连续5天,以Gries试剂测定了裸鼠腹腔巨噬细胞分泌NO的含量。结果表明:双歧杆菌注射组其腹腔巨噬细胞产生NO的量显著高于对照组,具有显著的统计学意义(P<001)。提示青春型双歧杆菌可激活巨噬细胞,使之产生一定量的NO,NO在介导双歧杆菌的多种生理功能方面起重要作用 相似文献
9.
目的 研究吲哚丙酸(IPA)对溃疡性结肠炎(UC)小鼠肠道巨噬细胞和肠道菌群的调节作用。方法 将SPF级6~8周龄雄性C57BL/6小鼠按随机数表法分为对照组、葡聚糖硫酸钠组(DSS模型组,饮用3%DSS7 d)及IPA组(在DSS给药前2 d行IPA灌胃),每组12只。每日观察小鼠体质量变化;DSS给药第7天处死小鼠,测量结肠长度及评定病理学评分,采用流式细胞术检测肠道巨噬细胞M1/M2比例,并用16S r RNA基因测序技术检测肠道菌群的变化。结果 与对照组比较,DSS模型组小鼠体质量显著下降,结肠组织病理学评分、肠道巨噬细胞M1/M2比值显著升高,结肠长度显著缩短(均P<0.05);与DSS模型组比较,IPA组小鼠体质量下降程度降低,结肠长度增加,结肠组织病理学评分、肠道巨噬细胞M1/M2比值均降低(均P<0.05);增加了肠道菌群丰度及多样性,显著增加了普雷沃菌属丰度,减少了拟杆菌属和肠球菌属的丰度。结论 IPA可以通过调节肠道巨噬细胞M1/M2的比例和增加肠道菌群多样性缓解UC小鼠的症状。 相似文献
10.
11.
巨噬细胞凋亡及其调控 总被引:4,自引:0,他引:4
巨噬细胞通过介导和调控自身及其他细胞凋亡而实现其免疫调节和效应细胞功能.引起巨噬细胞凋亡的原因有生物、化学、病理、自身等因素.不仅巨噬细胞自身凋亡和凋亡调控有其特点,更为有趣的是,巨噬细胞可根据需要:介导或抑制自身凋亡;介导或抑制其他细胞凋亡;抑制自身凋亡,介导其他细胞凋亡.这可能是巨噬细胞在免疫调节,特别是肿瘤免疫中发挥重要作用的基础. 相似文献
12.
13.
14.
Shaoxiong Yang Yingxin Qi Zonglai Jiang Xiaobo Gong 《Molecular & cellular biomechanics : MCB》2019,16(1):13-26
Vascular diseases during aging process are closely correlated to the age-related changes of mechanical stimuli for resident cells. Characterizing the variations of mechanical environments in vessel walls with advancing age is crucial for a better understanding of vascular remodeling and pathological changes. In this study, the mechanical stress, strain, and wall stiffness of the femoropopliteal arteries (FPAs) were compared among four different age groups from adolescent to young, middle-aged, and aged subjects. The material parameters and geometries adopted in the FPA models were obtained from published experimental results. It is found that high mechanical stress appears at different layers in young and old FPA walls respectively. The characteristics of the middle-aged FPA wall suggests that it is the most capable of resisting high blood pressures and maintaining a mechanical homeostasis during the entire life span. It is demonstrated that the variations of stress and strain rather than that of wall stiffness can be used as an indicator to illustrate the profile of FPA aging. Our results could serve as an age-specific mechanical reference for vascular mechanobiological studies, and allow further exploration of cellular dysfunctions in vessel walls during aging process. 相似文献
15.
《Autophagy》2013,9(12):1490-1499
The ability to respond and adapt to changes in the physical environment is a universal and essential cellular property. Here we demonstrated that cells respond to mechanical compressive stress by rapidly inducing autophagosome formation. We measured this response in both Dictyostelium and mammalian cells, indicating that this is an evolutionarily conserved, general response to mechanical stress. In Dictyostelium, the number of autophagosomes increased 20-fold within 10 min of 1 kPa pressure being applied and a similar response was seen in mammalian cells after 30 min. We showed in both cell types that autophagy is highly sensitive to changes in mechanical pressure and the response is graduated, with half-maximal responses at ~0.2 kPa, similar to other mechano-sensitive responses. We further showed that the mechanical induction of autophagy is TOR-independent and transient, lasting until the cells adapt to their new environment and recover their shape. The autophagic response is therefore part of an integrated response to mechanical challenge, allowing cells to cope with a continuously changing physical environment. 相似文献
16.
17.
The ability to respond and adapt to changes in the physical environment is a universal and essential cellular property. Here we demonstrated that cells respond to mechanical compressive stress by rapidly inducing autophagosome formation. We measured this response in both Dictyostelium and mammalian cells, indicating that this is an evolutionarily conserved, general response to mechanical stress. In Dictyostelium, the number of autophagosomes increased 20-fold within 10 min of 1 kPa pressure being applied and a similar response was seen in mammalian cells after 30 min. We showed in both cell types that autophagy is highly sensitive to changes in mechanical pressure and the response is graduated, with half-maximal responses at ~0.2 kPa, similar to other mechano-sensitive responses. We further showed that the mechanical induction of autophagy is TOR-independent and transient, lasting until the cells adapt to their new environment and recover their shape. The autophagic response is therefore part of an integrated response to mechanical challenge, allowing cells to cope with a continuously changing physical environment. 相似文献
18.
19.
逆境胁迫诱导基因的结构、功能与表达调控 总被引:8,自引:0,他引:8
对有关逆境响应基因的最新进展作了一简要的综述.在逆境条件下,脱落酸(ABA)浓度增加,诱导许多新的基因表达及蛋白质合成.已克隆到几百种逆境响应基因,其中大多数可受外源ABA的诱导.对这些基因及蛋白质的功能已有所了解,认为它们可能与植物的抗逆能力有关.目前认为有多条信号传递途径参与胁迫信号的转导. 相似文献
20.
Regulation of antimicrobial peptide production by autoinducer-mediated quorum sensing in lactic acid bacteria 总被引:2,自引:0,他引:2
Quadri LE 《Antonie van Leeuwenhoek》2002,82(1-4):133-145
Several lactic acid bacteria produce peptides with antimicrobial activity. During the last few years, cell–cell communication has emerged as the key regulatory mechanism that controls the production of many of these antimicrobial peptides via a regulatory strategy denominated quorum sensing. Quorum sensing allows population-wide synchronised production of antimicrobial peptides as a function of cell density. The cell–cell communication phenomenon required for sensing of the cell density is mediated by secreted signalling molecules. These molecular messengers accumulate in the environment as the cell density increases and activate signal transduction cascades that result in the production of antimicrobial peptides by the stimulated bacterial cell. 相似文献