C3aR过度活化与糖尿病肾病肾组织损伤的关系

C3aR是补体C3裂解产物C3a的受体.最近的一些研究提示C3aR通路可能参与了糖尿病肾病(DN)的病理过程,但有关C3aR通路在DN中的确切病理作用及有关机制远未清楚.需要特别指出的是,现有的有关C3aR参与DN肾组织损伤的证据主要来自一些动物模型的研究,临床上尚缺乏较为系统全面的对DN患者肾组织C3aR通路与肾组织损伤关系的观察分析.为此,本文首次以较大的样本量分析了不同病理时期DN患者肾组织C3aR和C3a的表达变化情况及其与DN患者肾组织损伤的相关性.在此基础上,进而利用体外细胞模型,对高糖环境下C3aR活化致肾小球足细胞损伤的作用及机制进行了探讨.结果显示:a.与正常对照组相比,DN患者肾组织C3a和C3aR的表达水平随DN的进展而升高,C3aR在DN患者肾组织中的表达上调主要见于肾小管上皮细胞和肾小球足细胞;b.DN患者肾组织C3aR和C3a水平与患者肾组织损伤程度,特别是小管和小管间质损伤程度、肾小球足细胞损伤程度具有显著相关性;c.外加C3a激活C3aR可使高糖环境中的足细胞的细胞骨架发生明显改变、足细胞标记分子表达下调、足细胞通透性增加.这些结果说明:a.DN患者肾组织中确实存在C3a/C3aR轴过度活化的现象;b.C3a/C3aR轴的过度活化很可能在DN患者肾组织损伤,特别是小管和小管间质损伤、肾小球足细胞损伤中具有重要作用;c.可能通过破坏成熟足细胞特有的细胞骨架,改变足细胞标记分子表达,增加足细胞的通透性,C3a/C3aR轴过度活化参与DN足细胞损伤过程.本文不仅为C3a/C3aR通路参与DN病理过程提供了新的必不可少的临床证据,也增加了对C3a/C3aR通路过度活化致DN患者肾组织损伤机制,特别是肾小球足细胞损伤机制的了解,这对于拓展对DN病理机制的认识,发展DN防治新思路,无疑都是有益的.     

肥大细胞及肠嗜铬细胞在人胃消化性溃疡发病中的作用

目的探讨肥大细胞与肠嗜铬细胞在人胃溃疡发病中的作用。方法收集胃溃疡标本90例,正常胃组织30例。采用甲苯胺兰检测肥大细胞的数量、分布,免疫组化染色检测类胰蛋白酶、5-羟色胺表达,另取5例新鲜胃溃疡组织进行电镜检测。结果溃疡组与对照组比较肥大细胞及肠嗜铬细胞数量均明显增加（P〈0.05）,肥大细胞在溃疡组脱颗粒现象明显,线性相关分析显示肥大细胞与肠嗜铬细胞数量呈正相关,相关系数为0.741。结论肥大细胞与肠嗜铬细胞在人胃溃疡发病中均发挥了作用。     

MMP-3、TIMP-3在人胃癌组织中的表达及意义

目的:探讨MMP-3和TIMP-3在人胃癌组织中的表达及其意义.方法:根据胃癌的病理大体分型将40例胃癌组织分为早期组和晚期组.其中,早期组同时不伴有淋巴结转移,晚期组伴有淋巴结转移.采用光镜、透射电镜和免疫组化方法对这两组胃癌组织的超微结构,MMP-3,TIMP-3表达和MMP-3/TIMP-3的比值进行检测.结果:MMP-3和TIMP-3主要表达于癌细胞胞浆内.早期组MMP-3阳性表达细胞较少,晚期组阳性细胞较多,二者数密度和面密度比较,具有统计学意义(P＜0.01);早期组TIMP-3阳性表达细胞较多,晚期组阳性细胞较少,二者比较,具有统计学意义(P＜0.01)MM-3/TIMP-3的比值在胃癌晚期较早期增大,具有统计学意义(P＜0.01);电镜观察显示胃癌早期淋巴细胞浸润较多,癌细胞穿基膜不明显,晚期则淋巴细胞浸润较少,癌细胞穿基膜明显.结论:MMP-3,TIMP-3的表达程度和MMP-3/TIMP-3的比值可作为判定胃癌的侵袭和转移的指标,对其预后的判断具有参考价值.     

MMP-3、TIMP-3在人胃癌组织中的表达及意义

目的:探讨MMP-3和TIMP-3在人胃癌组织中的表达及其意义.方法:根据胃癌的病理大体分型将40例胃癌组织分为早期组和晚期组.其中,早期组同时不伴有淋巴结转移,晚期组伴有淋巴结转移.采用光镜、透射电镜和免疫组化方法对这两组胃癌组织的超微结构,MMP-3,TIMP-3表达和MMP-3/TIMP-3的比值进行检测.结果:MMP-3和TIMP-3主要表达于癌细胞胞浆内.早期组MMP-3阳性表达细胞较少,晚期组阳性细胞较多,二者数密度和面密度比较,具有统计学意义(P＜0.01);早期组TIMP-3阳性表达细胞较多,晚期组阳性细胞较少,二者比较,具有统计学意义(P＜0.01)MMP-3/TIMP-3的比值在胃癌晚期较早期增大,具有统计学意义(P＜0.01);电镜观察显示胃癌早期淋巴细胞浸润较多,癌细胞穿基膜不明显,晚期则淋巴细胞浸润较少,癌细胞穿基膜明显.结论:MMP-3,TIMP-3的表达程度和MMP-3/TIMP-3的比值可作为判定胃癌的侵袭和转移的指标,对其预后的判断具有参考价值.     

缺氧通过HIF-1α/NF-κB通路诱导肾小管上皮细胞C3aR表达（英文）

C3aR是补体C3a的受体.在肾脏,已发现C3aR表达于包括肾小管上皮细胞在内的多种细胞.在特定的病理情况下,C3aR表达上调并参与多种肾脏疾病的病理过程,但有关C3aR在肾脏细胞中的表达调控机制仍不清楚.小管间质缺氧是肾脏疾病中的一种常见现象,也是一种重要致病因素.为了探讨缺氧对C3aR的表达调控作用,本文利用体外缺氧模型,对模型条件下C3aR在肾小管上皮细胞中的表达变化情况进行了分析,同时检测了HIF-1α和NF-κB的表达变化及活化情况,以及HIF-1α和NF-κB抑制剂对C3aR的表达影响情况.结果发现缺氧可诱导C3aR mRNA及蛋白质水平的表达上调、HIF-1α和NF-κB的核转移.HIF-1α和NF-κB抑制剂可阻断缺氧对C3aR的诱导作用,且HIF-1α抑制剂可抑制NF-κB的核转移.这些结果说明缺氧可通过HIF-1α/NF-κB通路诱导肾小管上皮细胞C3aR的表达.考虑到C3aR活化可促进肾小管的损伤,我们推测C3aR通路可能参与了缺氧和NF-κB诱导的肾小管损伤过程,可能是防治缺氧和NF-κB诱导肾组织损伤的一个新靶标.     

肥大细胞浸润及原癌基因c-fos表达可引起下肢静脉曲张

为了探究肥大细胞浸润及原癌基因c-fos表达情况与下肢静脉曲张的相关性,本研究选择了我院100名下肢静脉曲张患者,按照下肢静脉曲张的患病程度分成轻度组39人、中度组32人和重度组29人;正常组随机选择35例同期需大隐静脉作供体移植或截肢的无周围血管疾患的患者。采用甲苯胺蓝染色法观察肥大细胞浸润程度,免疫组织化学染色计算血管平滑肌细胞c-fos蛋白阳性细胞百分率,以肥大细胞浸润程度作为自变量、原癌基因c-fos阳性率作为因变量绘制回归曲线并计算肥大细胞浸润程度与原癌基因c-fos表达相关系数。结果显示正常大隐静脉、曲张静脉管壁均有肥大细胞存在,曲张大隐静脉存在病理性肥大细胞浸润,并且随病情加重而增多,阳性细胞数量随静脉曲张程度加重而增多,不同患病程度静脉曲张患者c-fos水平均明显高于正常组(p0.05或p0.01),且随患病程度加重表达增强,但差异无显著性(p0.05)。在下肢静脉曲张静脉壁中,c-fos呈阳性的血管平滑肌细胞(VSMC)比例与肥大细胞数符合线性正相关(r=0.983, p0.01)。从研究结果可以推测,静脉壁发生改变而引起下肢静脉曲张的机理可能是肥大细胞通过释放各种介质激活血管平滑肌细胞中c-fos原癌基因表达,进而促进下肢静脉曲张的发生。     

缺氧通过HIF-1α/NF-κB通路诱导肾小管上皮细胞C3aR表达

C3aR是补体C3a的受体．在肾脏,已发现C3aR表达于包括肾小管上皮细胞在内的多种细胞．在特定的病理情况下,C3aR表达上调并参与多种肾脏疾病的病理过程,但有关C3aR在肾脏细胞中的表达调控机制仍不清楚．小管间质缺氧是肾脏疾病中的一种常见现象,也是一种重要致病因素．为了探讨缺氧对C3aR的表达调控作用,本文利用体外缺氧模型,对模型条件下C3aR在肾小管上皮细胞中的表达变化情况进行了分析,同时检测了HIF-1α和NF-κB的表达变化及活化情况,以及HIF-1α和NF-κB抑制剂对C3aR的表达影响情况．结果发现缺氧可诱导C3aR mRNA及蛋白质水平的表达上调、HIF-1α和NF-κB的核转移．HIF-1α和NF-κB抑制剂可阻断缺氧对C3aR的诱导作用,且HIF-1α抑制剂可抑制NF-κB的核转移．这些结果说明缺氧可通过HIF-1α/NF-κB通路诱导肾小管上皮细胞C3aR的表达．考虑到C3aR活化可促进肾小管的损伤,　我们推测C3aR通路可能参与了缺氧和NF-κB诱导的肾小管损伤过程,可能是防治缺氧和NF-κB诱导肾组织损伤的一个新靶标．     

人胃癌组织中乙酰肝素酶和S-100蛋白的表达及其意义

目的:探讨乙酰肝素酶和S-100蛋白在人胃癌组织中的表达及其意义。方法:根据胃癌的病理大体分型将40例胃癌组织分为早期组和晚期组。其中,早期组同时未伴有淋巴结转移,晚期组伴有淋巴结转移。采用光镜、透射电镜、原位杂交和免疫组化方法对这两组胃癌组织的超微结构,乙酰肝素酶和S-100蛋白表达进行检测。结果:早期组乙酰肝素酶阳性表达细胞较少,晚期组阳性细胞较多,二者数密度和面密度比较。具有统计学意义(P<0.01);早期组S-100蛋白阳性表达细胞较晚期组多,二者比较,具有统计学意义(P<0.01);电镜观察可见:在胃癌早期,淋巴细胞和树突状细胞浸润较多,树突状细胞突起与淋巴细胞相接触,基底膜基本完整。晚期,基底膜几乎消失。淋巴细胞和树突状细胞浸润较少,癌细胞穿基膜明显。结论:乙酰肝素酶和S-100蛋白的表达程度可作为判定胃癌的侵袭和转移的指标,对其预后的判断具有参考价值。     

过敏毒素受体(C3aR)在db/db糖尿病肾病小鼠肾脏中的表达及病理意义分析

利用半定量RT-PCR、免疫组化和Western blotting的方法,同时从mRNA水平和蛋白质水平对过敏毒素受体(C3aR)在不同病理阶段的2型糖尿病肾病模型小鼠——db/db小鼠肾脏中的表达情况进行了较为系统的分析．结果发现：a．在糖尿病前的db/db小鼠(4周龄的db/db小鼠),C3aR与作为正常对照的db/m小鼠相比没有明显差异．随着肥胖的加剧,高血糖、蛋白尿的发生和发展,C3aR在db/db小鼠肾脏中的表达显著升高．b．免疫组化分析显示,C3aR广泛地表达于db/m和db/db小鼠肾脏的皮质和髓质,分布于肾脏的上皮细胞中(包括肾小管上皮细胞、肾小球中的脏层上皮细胞(足细胞)和壁层上皮细胞)．从部位来看,皮髓交界处的肾小管中C3aR表达量明显要比其他部位的多．在肾小球,C3aR特异地存在于足细胞部位．在db/m小鼠,不同周龄小鼠肾脏中C3aR的表达量并没有明显变化,但在db/db小鼠,从8周龄开始,分布在db/db小鼠肾小管上皮细胞和小球足细胞中的C3aR均随小鼠周龄的增加而增加,至少在时间上,与小鼠糖尿病肾病的发生发展相关,其中尤以足细胞中和皮髓交界处肾小管上皮细胞中的变化最为明显． c．在糖尿病肾病小鼠中高表达C3aR的肾小管上皮细胞常有空泡变性的情况．上述工作印证了先前对2型糖尿病肾病患者肾小球基因表达谱的分析结果,更加明确了C3aR与糖尿病肾病的相关性,同时揭示了C3aR在正常小鼠和糖尿病肾病小鼠肾脏中的表达、分布和变化规律,有利于进一步揭示C3aR的功能及其在糖尿病肾病发生、发展过程中的可能作用,探讨糖尿病肾病的分子机制．     

从甲状腺肥大细胞探讨胎儿器官肥大细胞的差异

研究肥大细胞在人胎儿甲状腺发育中数量、分布及组化性质的改变,以探讨胎儿器官发育中肥大细胞的差异。取45例不同胎龄的人胎甲状腺石蜡切片做甲苯胺蓝染色和阿尔辛蓝－－藏红染色,并测定肥大细胞的临界电解质浓度值及进行硫酸小蘖硷荧光染色。结果显示：3月龄胎儿甲状腺内开始出现肥大细胞,数量极少,主要分布在被膜及小叶间结缔组织内,甲苯胺蓝染色肥大细胞颗粒呈淡紫蓝色,阿尔辛蓝－－藏红染色呈蓝色,临界电解质浓度值较低,硫酸小蘖硷染色未见显黄色荧乐的肥大细胞,从3月龄到足月随着胎龄增长,肥大细胞数量缓慢增多,8月龄时肥大细胞经甲苯胺蓝染色,其颗粒呈紫红色,阿尔辛蓝－－藏红染色出现少量含红色和红蓝混合染色颗粒的肥大细胞,临界电解质浓度值偏高,可见少量显黄色荧光的肥大细胞,结果表明：在人胎儿3月龄时甲状腺发育中开始出现肥大细胞,但随胎儿发育肥大细胞的组化性质改变不明显。     

Regulation of C3a receptor signaling in human mast cells by G protein coupled receptor kinases

Background

The complement component C3a activates human mast cells via its cell surface G protein coupled receptor (GPCR) C3aR. For most GPCRs, agonist-induced receptor phosphorylation leads to receptor desensitization, internalization as well as activation of downstream signaling pathways such as ERK1/2 phosphorylation. Previous studies in transfected COS cells overexpressing G protein coupled receptor kinases (GRKs) demonstrated that GRK2, GRK3, GRK5 and GRK6 participate in agonist-induced C3aR phosphorylation. However, the roles of these GRKs on the regulation of C3aR signaling and mediator release in human mast cells remain unknown.

Methodology/Principal Findings

We utilized lentivirus short hairpin (sh)RNA to stably knockdown the expression of GRK2, GRK3, GRK5 and GRK6 in human mast cell lines, HMC-1 and LAD2, that endogenously express C3aR. Silencing GRK2 or GRK3 expression caused a more sustained Ca²⁺ mobilization, attenuated C3aR desensitization, and enhanced degranulation as well as ERK1/2 phosphorylation when compared to shRNA control cells. By contrast, GRK5 or GRK6 knockdown had no effect on C3aR desensitization, but caused a significant decrease in C3a-induced mast cell degranulation. Interestingly, GRK5 or GRK6 knockdown rendered mast cells more responsive to C3a for ERK1/2 phosphorylation.

Conclusion/Significance

This study demonstrates that GRK2 and GRK3 are involved in C3aR desensitization. Furthermore, it reveals the novel finding that GRK5 and GRK6 promote C3a-induced mast cell degranulation but inhibit ERK1/2 phosphorylation via C3aR desensitization-independent mechanisms. These findings thus reveal a new level of complexity for C3aR regulation by GRKs in human mast cells.     

Cells containing IgE in the intestinal mucosa of mice infected with the nematode parasite Trichinella spiralis are predominantly of a mast cell lineage

To determine whether IgE+ cells in the intestinal mucosa of nematode-infected mice were of a mast cell or a lymphocyte lineage, the intestinal mucosae of mast cell-deficient w/wv mice were examined for IgE+ cells after inoculation with Trichinella spiralis muscle-stage larvae. Immunofluorescence staining techniques were used to detect IgE associated with cells in the intestinal mucosa. Comparisons were made among four strains of mice, w/wv (mast cell-deficient), +/+ (normal congenic littermates of w/wv), BALB/c, and SJL, that were either uninfected controls or inoculated with T. spiralis. Tissue sections from the small intestine of T. spiralis-infected BALB/c, SJL, and +/+ mice were fixed in ethanol and were stained with an affinity-purified F(ab')2 rabbit anti-mouse IgE followed by FITC goat anti-rabbit IgG. Large numbers of cells in the intestinal mucosa exhibited bright fluorescence. When other sections of intestines from these mice were processed in Carnoy's fixative and were stained with alcian blue at low pH (a metachromatic stain for mast cells) or alcian blue followed by immunofluorescence staining for IgE, large numbers of mast cells were observed in the intestinal mucosa, and 70 to 90% stained positively for IgE. There was a considerable number of cells in the intestinal mucosa which were IgE+ but which did not stain with alcian blue. Few alcian blue-positive cells and no IgE+ staining cells were present in the intestinal mucosa of control, uninfected +/+, BALB/c, and SJL mice. To determine whether these IgE+ alcian blue-negative cells were of a lymphocyte or a mast cell lineage, the mast cell-deficient w/wv mouse strain was examined after infection with T. spiralis. In contrast to BALB/c, SJL, or +/+ mice, few cells in the intestinal mucosa of T. spiralis-infected w/wv mice stained with alcian blue or were positive for IgE. However, when the IgE response in the MLN of the w/wv mice was compared to the IgE response of BALB/c, SJL, and +/+ mice, numerous IgE+ cells, but no alcian blue-positive cells, were observed in the parenchyma of the MLN from all four strains of T. spiralis-infected mice. In addition, flow microfluorometric analysis of MLN cells stained for surface IgE in suspension showed a comparable proportion of IgE-bearing cells, which were mostly B lymphocytes, among all four strains of T. spiralis-infected mice.(ABSTRACT TRUNCATED AT 400 WORDS)     

Aging-associated shifts in functional status of mast cells located by adult and aged mesenteric lymphatic vessels

We had previously proposed the presence of permanent stimulatory influences in the tissue microenvironment surrounding the aged mesenteric lymphatic vessels (MLV), which influence aged lymphatic function. In this study, we performed immunohistochemical labeling of proteins known to be present in mast cells (mast cell tryptase, c-kit, prostaglandin D(2) synthase, histidine decarboxylase, histamine, transmembrane protein 16A, and TNF-α) with double verification of mast cells in the same segment of rat mesentery containing MLV by labeling with Alexa Fluor 488-conjugated avidin followed by toluidine blue staining. Additionally, we evaluated the aging-associated changes in the number of mast cells located by MLV and in their functional status by inducing mast cell activation by various activators (substance P; anti-rat DNP Immunoglobulin E; peptidoglycan from Staphyloccus aureus and compound 48/80) in the presence of ruthenium red followed by subsequent staining by toluidine blue. We found that there was a 27% aging-associated increase in the total number of mast cells, with an ～400% increase in the number of activated mast cells in aged mesenteric tissue in resting conditions with diminished ability of mast cells to be newly activated in the presence of inflammatory or chemical stimuli. We conclude that higher degree of preactivation of mast cells in aged mesenteric tissue is important for development of aging-associated impairment of function of mesenteric lymphatic vessels. The limited number of intact aged mast cells located close to the mesenteric lymphatic compartments to react to the presence of acute stimuli may be considered contributory to the aging-associated deteriorations in immune response.     

Distinct tissue site-specific requirements of mast cells and complement components C3/C5a receptor in IgG immune complex-induced injury of skin and lung.

We induced the passive reverse Arthus reaction to IgG immune complexes (IC) at different tissue sites in mice lacking C3 treated or not with a C5aR-specific antagonist, or in mice lacking mast cells (Kit(W)/Kit(W-v) mice), and compared the inflammatory responses with those in the corresponding wild-type mice. We confirmed that IC inflammation of skin can be mediated largely by mast cells expressing C5aR and FcgammaRIII. In addition, we provided evidence for C3-independent C5aR triggering, which may explain why the cutaneous Arthus reaction develops normally in C3(-/-) mice. Furthermore, some, but not all, of the acute changes associated with the Arthus response in the lung were significantly more intense in normal mice than in C3(-/-) or Kit(W)/Kit(W-v) mice, indicating for C3- and mast cell-dependent and -independent components. Finally, we demonstrated that C3 contributed to the elicitation of neutrophils to alveoli, which corresponded to an increased synthesis of TNF-alpha, macrophage-inflammatory protein-2, and cytokine-induced neutrophil chemoattractant. While mast cells similarly influenced alveolar polymorphonuclear leukocyte influx, the levels of these cytokines remained largely unaffected in mast cell deficiency. Together, the phenotypes of C3(-/-) mice and Kit(W)/Kit(W-v) mice suggest that complement and mast cells have distinct tissue site-specific requirements acting by apparently distinct mechanisms in the initiation of IC inflammation.     

Staining properties of duodenal mast cells in 48/80-treated rats

Summary Mast cells in the tongue, mesentery and lamina propria of the duodenal mucosa in normal and 48/80-treated rats were observed at different time intervals. The tissues were studied comparatively after staining with toluidine blue, acridine orange or alcian bluesafranin. Under the experimental conditions used, the mast cells in the tongue and mesentery showed constant positive reactions to toluidine blue and acridine orange, both of which failed to demonstrate the presence of mast cells in the lamina propria of the duodenal mucosa. The combined alcian blue-safranin stain elicited a safranin-positive reaction in the mast cells of the tongue and mesentery and an alcian blue reaction in those of the lamina propria of the duodenal mucosa. This alcianophilia of the duodenal mast cells was not affected by compound 48/80. On the other hand, the safranin stain of the tongue and mesentery mast cells was altered to alcian blue by the drug. The results are discussed in the light of recent developments in mast cell research.This work was supported by grant MA-2236 of the Medical Research Council of Canada.     

C3a Receptor Antagonist Ameliorates Inflammatory and Fibrotic Signals in Type 2 Diabetic Nephropathy by Suppressing the Activation of TGF-β/smad3 and IKBα Pathway

Objective

Diabetic nephropathy (DN) is a serious complication for patients with diabetes mellitus (DM). Emerging evidence suggests that complement C3a is involved in the progression of DN. The aim of this study was to investigate the effect of C3a Receptor Agonist (C3aRA) on DN and its potential mechanism of action in rats with type 2 diabetes mellitus (T2DM).

Methods

T2DM was induced in SD rats by a high fat diet (HFD) plus repeated low dose streptozocin (STZ) injections. T2DM rats were treated with vehicle or C3aRA for 8 weeks. Biochemical analysis, HE and PAS stains were performed to evaluate the renal function and pathological changes. Human renal glomerular endothelial cells (HRGECs) were cultured and treated with normal glucose (NG), high glucose (HG), HG+C3a, HG+C3a+C3aRA and HG+C3a+BAY-11-7082 (p-IKBα Inhibitor) or SIS3 (Smad3 Inhibitor), respectively. Real-time PCR, immunofluorescent staining and western blot were performed to detect the mRNA and protein levels, respectively.

Results

T2DM rats showed worse renal morphology and impaired renal function compared with control rats, including elevated levels of serum creatinine (CREA), blood urea nitrogen (BUN) and urine albumin excretion (UACR), as well as increased levels of C3a, C3aR, IL-6, p-IKBα, collagen I, TGF-β and p-Smad3 in the kidney of T2DM rats and C3a-treated HRGECs. In contrast, C3aRA treatment improved renal function and morphology, reduced CREA, UACR and the intensity of PAS and collagen I staining in the kidney of T2DM rats, and decreased C3a, p-IKBα, IL-6, TGF-β, p-Smad3 and collagen I expressions in HRGECs and T2DM rats.

Conclusion

C3a mediated pro-inflammatory and pro-fibrotic responses and aggravated renal injury in T2DM rats. C3aRA ameliorated T2DN by inhibiting IKBα phosphorylation and cytokine release, and also TGF-β/Smad3 signaling and ECM deposition. Therefore, complement C3a receptor is a potential therapeutic target for DN.