Beraprost sodium,prostacyclin analogue,attenuates glomerular hyperfiltration and glomerular macrophage infiltration by modulating ecNOS expression in diabetic rats

Stable prostacyclin analogue, beraprost sodium (BPS) has recently been reported to attenuate glomerular hyperfiltration in diabetic rats, however, the mechanism has been still unknown. We previously reported that overexpression of endothelial cell nitric oxide synthase (ecNOS) in afferent arterioles and glomeruli induce inappropriate dilatation of afferent arterioles and glomerular hyperfiltration through overproduction of nitric oxide in early stage of diabetic nephropathy. In this study, we tested the hypothesis that BPS ameliorates glomerular hyperfiltration through modulating ecNOS expression in diabetic nephropathy. Furthermore, we examined the effects of BPS on the expression of intercellular adhesion molecule-1 (ICAM-1) and macrophage infiltration in diabetic glomeruli, because glomerular hyperfiltration induces the expression of ICAM-1 resulting in macrophage infiltration. Male Sprague-Dawley (SD) rats were administered continuously with BPS for 4 weeks after induction of diabetes by streptozotocin. In diabetic rats, the diameters of afferent arterioles, glomerular volume, creatinine clearance and urinary excretion of albumin and NO2/NO3 were increased as compared with non-diabetic control rats. Treatment with BPS improved these changes. The expression of ecNOS was increased in afferent arterioles and glomeruli in diabetic rats and suppressed by BPS. Prostacyclin receptor was expressed along afferent arterioles. Our results suggest that BPS attenuates glomerular hyperfiltration by modulating ecNOS expression in early stage of diabetic nephropathy. Moreover, BPS may inhibit ICAM-1-dependent infiltration of macrophages in diabetic glomeruli.     

选择素在脑缺血再灌注损伤中的作用

选择素是黏附分子的一个家族,由P-选择索、L-选择素和E-选择素组成。这3种黏附分子均参与了脑缺血再灌注损伤的炎症过程。P-选择素在激活的血小板和内皮细胞表达,而E-选择素仅在血管内皮细胞表达,两者共同介导白细胞、血小板与内皮细胞的黏附。L-选择素主要在白细胞表达,介导白细胞在微血管内皮细胞上的滚动接触。     

基质金属蛋白酶-9和金属蛋白酶组织抑制物-1在IgA肾病肾组织中的表达

目的 探讨基质金属蛋白酶－9（MMP－9）／金属蛋白酶组织抑制物－1（TIMP－1）系统在IgA肾病肾组织中的表达及其对IgA肾病的进展的影响。方法 采用免疫组织化学和原位杂交技术,分别在蛋白质和基因水平检测38例IgA肾病患者肾组织中的MMP－9和TIMP－1的变化。结果 MMP－9在正常肾脏肾小球的脏层上皮细胞和内皮细胞有少量表达,在肾小管上皮细胞和间质血管壁也有少量表达;在IgA肾病中,MMP－9在系膜增殖性肾小球和间质血管壁的表达均明显增多（P＜0．001）,而在硬化肾小球内的表达则明显减少,肾小管细胞的MMP－9表达无明显变化。TIMP－1在正常肾组织中不能检出,在IgA肾病患者具有系膜增殖性病变的肾小球中有微量表达,在增殖在很重但尚未完全硬化的肾小球内表达增多,在肾小管间质表达最为明显（P＜0．001）,其主要见于肾小管细胞、间质细胞和血管内皮细胞。肾组织中的TIMP－1表达与血清肌酐水平呈显著相关（P＜0．05）,与肾小管间质的纤维化和炎细胞浸润程度亦明显相关（P值均＜0．01）。肾小球中的MMP－9表达与尿蛋白无明显相关性,但与血清肌酐水平呈显著负相关（P＜0．05）。结论 MMP－9和TIMP－1的异常表达可能是影响IgA肾病进展的因素之一。     

The effect of macrophage colony-stimulating factor (M-CSF) on the progression of lipid-induced nephrotoxicity in diabetic nephropathy

In order to elucidate the role of macrophage in lipid-induced nephrotoxicity in diabetic nephropathy, we examined the effect of macrophage colony-stimulating factor (M-CSF) on the progression of renal lesions in hypercholesterolemic steptozotocin (STZ)-diabetic rats fed with high cholesterol chow. Hypercholesterolemia aggravated albuminuria in diabetic rats accompanied by infiltration of macrophages in glomeruli. Treatment with M-CSF suppressed simultaneously infiltration of glomerular macrophages and urinary albumin excretion in hypercholesterolemic diabetic rats. These results suggest that infiltration of glomerular macrophage has a primary role in lipid-induced nephrotoxicity in diabetic nephropathy, and M-CSF is involved in this process as a preventive factor.     

Leucocyte-endothelial cell adhesion in a model of intestinal inflammation.

Leucocyte-endothelial cell adhesion is modulated by a variety of adhesion glycoprotein expressed on the surface of leucocytes and endothelial cells. Although in vitro studies show that these adhesion molecules mediate the decrease in leucocyte rolling velocity and the increase in leucocyte adherence and emigration associated with inflammation, there are few in vivo data to support this hypothesis. The aim of this study was to assess the role of leucocyte (CD11b/CD18) and endothelial cell (P- and E-selectin) adhesion molecules in mediating the leucocyte-endothelial cell adhesion elicited in rat mesenteric venules during a model of longlasting intestinal inflammation. Indomethacin was injected 48 and 24 hours before the experiment. The mesenteric microcirculation was observed by intravital microscopy in animals treated with monoclonal antibodies (MAb) directed against either P-selectin, E-selectin, or CD11b/CD18. Leucocyte rolling velocity, and the number of adherent and emigrated leucocytes as well as vessel diameter and erythrocyte velocity were monitored in roughly 30 micron diameter postcapillary venules. Indomethacin treatment resulted in mucosal ulceration and granulocyte infiltration, and a corresponding inflammatory response in the mesentery, which was characterised by an increase in the number of adherent (eightfold) and emigrated (sixfold) leucocytes and a reduction (80%) in leucocyte rolling velocity. The indomethacin induced leucocyte-endothelial cell adhesion in mesenteric venules was significantly reduced by treatment with MAbs against either CD11b/CD18 or E-selectin, but not by the P-selectin MAb. These results suggest that both leukocyte (CD11b/CD18) and endothelial cell (E-selectin) adhesion molecules contribute to the granulocyte accumulation in a chronic model of intestinal inflammation.     

Renal changes in long-term Type 1 (insulin-dependent) diabetic patients with and without clinical nephropathy: a light microscopic,morphometric study of autopsy material

Summary The relationship between clinical diabetic nephropathy and morphological renal changes was studied in autopsy material from 34 long-term Type 1 (insulin-dependent) diabetic patients of juvenile onset. Seventeen had no clinical signs of nephropathy (defined by persistent proteinuria, hypertension, and elevated serum creatinine) while a further 17 age-matched diabetic patients with a similar duration of diabetes had severe clinical nephropathy. The renal tissue was examined by morphometric light microscopy, using a point counting technique and the results compared with renal tissue from subjects who died without diabetes. In the diabetic patients without clinical nephropathy, arteriolohyalinosis was much more pronounced compared with non-diabetic subjects (2p< 0.001) and within the glomeruli the amount of subcapsular fibrosis and glomerular mesangium was increased (2p < 0.05 and < 0.001, respectively). The area of open capillaries was decreased compared with non-diabetic subjects (2p < 0.025), and the percentage of occluded glomeruli was significantly increased (2p< 0.05). The diabetic patients with clinical nephropathy had significantly more interstitial tissue and glomerular mesangium (2p < 0.001) and less open glomerular capillaries (2p < 0.001) than diabetic subjects without clinical nephropathy, but severe glomerulosclerosis could be seen in the diabetic patients without any sign of clinical nephropathy. Serum creatinine correlated with the mesangial area (r = 0.792, 2 < 0.001). No difference was observed between the two diabetic groups regarding the degree of arteriolohyalinosis, the number of Kimmelstiel-Wilson lesions or exudative lesions. A significant negative correlation existed between the relative area of open capillaries and the relative area of mesangium (r =-0.86, 2 <0.001). Remarkable mesangial enhancement was present in most of the diabetic patients with, but also in several diabetic subjects without, clinical nephropathy. On the other hand, the area of open capillaries was within the normal range in most of the patients who did not show any clinical sign of nephropathy. Thus, preservation of a normal area of open capillaries in renal tissue from long-term diabetic patients with glomerulosclerosis seems to be a good light microscopic indicator of absence of clinical nephropathy.     

Histologic analysis of renal leukocyte infiltration in antineutrophil cytoplasmic antibody-associated vasculitis: importance of monocyte and neutrophil infiltration in tissue damage

OBJECTIVE: The histopathologic lesions in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have been studied extensively, but the exact composition of the cellular infiltrate is unclear. We undertook this study to analyze renal leukocyte infiltration and the cellular distribution within glomeruli and interstitium in 65 renal biopsy samples obtained from patients newly diagnosed as having AAV. METHODS: Renal cellular tissue infiltration was assessed with an immunoperoxidase method. Furthermore, the infiltrating cell types were correlated with clinical and histopathologic data. RESULTS: The predominant interstitial infiltrating cells were T lymphocytes, while monocytes and, to a lesser extent, granulocytes constituted the dominant infiltrating cell types in glomeruli. Interestingly, lymphocyte infiltration was predominantly periglomerular, especially around glomeruli with sclerosis or heavy crescent formation, while interstitial monocyte and neutrophil infiltration was diffusely distributed over the interstitial tissue. A significant correlation was found for the glomerular infiltration of CD68-positive macrophages with the presence of glomerular necrosis as well as with the number of glomeruli with crescents (P < 0.0001 and P = 0.005, respectively). No correlation was found for interstitial fibrosis with the infiltration of any leukocyte subset. Furthermore, a significant correlation was found for the interstitial as well as for the glomerular infiltration of CD68-positive macrophages with serum creatinine concentration at the time of biopsy (P = 0.001 and P = 0.006, respectively). CONCLUSION: These data underscore a major role of monocytes in addition to neutrophils in the tissue damage of AAV.     

Mechanisms of Lactoferrin-induced Leukocyte-Endothelial Cell Adhesion in Postcapillary Venules

Objective : The objective is to determine the contributions of electrostatic charge, endothelial cell adhesion glycoproteins (P- and E-selectins), and histamine to lactoferrin-induced leukocyte adhesion in postcapillary venules. Methods : Rat mesentery was prepared for intravital microscopic observation. Erythrocyte velocity, vessel diameter, leukocyte rolling velocity, number of adherent and emigrated leukocytes, and velocity, flux, and number of rolling leukocytes were monitored in mesenteric venules (25–35 μm initial diameter). After control measurements were obtained for all parameters, lactoferrin, other cationic proteins (histone or α-chymotrypsinogen A), or transferrin (an anionic iron-binding protein) were infused into the superior mesenteric artery, with repeat measurements taken 20 min into the infusion period. In other lactoferrin experiments, animals were treated with either a monoclonal antibody (MAb) directed against P- or E-selectin, an H₁- or H₂-histamine receptor antagonist, or diamine oxidase (histaminase). Results : Increased numbers of rolling and adherent leukocytes were observed during infusion of lactoferrin, histone, or α-chymotrypsinogen A but not with transferrin. The leukocyte-endothelial cell adhesion (LECA) elicited by lactoferrin was substantially greater than that induced by histone and α-chymotrypsinogen A. The P-selectin MAb completely prevented lactoferrin-induced LECA, whereas the E-selectin MAb had no effect. Diamine oxidase and the H_1? (but not the H_2?) receptor antagonist were also effective in attenuating lactoferrin-induced LECA. Conclusions : These results indicate that lactoferrin-induced LECA results from histamine-mediated expression of P-selectin on venular endothelial cells. The cationic nature of lactoferrin accounts for only a small part of its proadhesive actions.     

Computer imaging analysis of the correlation between intensities of glomerular immune-deposits and histopathology in patients with IgA nephropathy.

The relationship between the intensities of IgA, C3c, and C9 deposition in renal glomeruli and the severity of histopathologic injuries in patients with IgA nephropathy was examined using Microscope-Photometer 01K and a computer. Percentages of glomerular adhesion to Bowman's capsules, crescent formation, and glomerular sclerosis were calculated in the renal specimens. There was a significant correlation between the intensity of each C3c and C9 deposition in glomeruli and the degree of glomerular adhesion to Bowman's capsules and crescent formation in patients with IgA nephropathy. There was no significant correlation between the intensity of C3c or C9 deposition in glomeruli and the degree of glomerular sclerosis. No relationship was found between the intensity of IgA deposition in glomeruli and the degree of histopathologic injuries. The patients with negative or trace amounts of glomerular C3c deposits showed less severe glomerular injuries. Thus, the intensity of C3c and C9 deposition in glomeruli appears to be one of the critical factors responsible for the active progression of glomerular inflammatory process in patients with IgA nephropathy.     

Three-dimensional architecture of glomerular extracellular matrices in diabetic glomerulosclerosis

The three-dimensional ultrastructural changes of the glomerular extracellular matrices in diabetic glomerulosclerosis were studied in acellular rat and human diabetic glomeruli by scanning electron microscopy. The mesangial matrix appeared as fenestrated septa with oval stomata between the glomerular capillaries in normal control specimens. In diabetic glomerulosclerosis, both in humans and rats, expansion of mesangial matrix and narrowing of the mesangial fenestrae were observed. A thin layer of the mesangial matrix extended into the peripheral glomerular basement membrane (GBM) subendothelially. Thickening of the GBM in diabetic nephropathy might be due to expansion of the mesangial matrix into the peripheral GBM.     

Monocytes initiate a cycle of leukocyte recruitment when cocultured with endothelial cells

During the development of atherosclerotic plaque, monocytes and T-lymphocytes are recruited to the arterial intima by endothelial cells (EC) lining the vessel. This process is associated with chronic arterial inflammation and requires the activation-dependent expression of adhesion receptors and chemokines on EC. Here we show that monocytes can activate cocultured EC so that they support the adhesion, activation and transmigration of a secondary bolus of flowing peripheral blood monocytes or lymphocytes. The number of adherent leukocytes and their behaviour was comparable to that seen on EC activated with tumour necrosis factor-alpha (TNF-alpha). Depending upon the duration of endothelial cell/monocyte coculture different patterns of adhesion receptors were utilised by leukocytes. After 4 h coculture, antibodies against E-selectin, P-selectin and vascular cell adhesion molecule-1 (VCAM-1) reduced mononuclear leukocyte adhesion. After 24 h coculture, antibodies against E-selectin and VCAM-1 but not P-selectin were effective. Immunofluorescence analysis confirmed that monocyte coculture induced endothelial expression of E-selectin and VCAM-1, while P-selectin was at the limit of detection. We conclude that EC stimulated by monocytes can support the adhesion of flowing mononuclear leukocytes. We hypothesise that this mode of EC activation and leukocyte recruitment could initiate a self-perpetuating cycle of inflammation that could be relevant to atherogenesis and other chronic inflammatory disease states.     

Inhibition of selectin function and leukocyte rolling protects against dextran sodium sulfate-induced murine colitis

BACKGROUND: The selectin family of adhesion molecules (P-, E- and L-selectin) plays an important role in inflammatory reactions by mediating interactions between leukocytes and activated endothelial cells. However, a recent study using gene-targeted mice has suggested that adhesion molecules (P- and E-selectin and ICAM-1) may not be relevant targets in intestinal inflammation. The objective of the present study was to re-evaluate the potential role of selectins in experimental colitis in wild-type mice using the polysaccharide fucoidan, which inhibits the function of P- and L-selectin. METHODS: For this purpose, Balb/c mice were exposed to 5% dextran sodium sulfate (DSS) in the drinking water for 5 days with and without daily administration of fucoidan (25 mg/kg, i.v.). In separate experiments, the effect of fucoidan on leukocyte-endothelium interactions was examined by use of intravital microscopy. RESULTS: It was found that pretreatment with fucoidan (25 mg/kg/day) reduced mucosal damage and crypt destruction in the colon of DSS-treated mice. Moreover, this fucoidan treatment markedly reduced the colonic MPO activity in mice exposed to DSS. In vivo microscopy revealed that the dose of fucoidan used in the present study abolished TNF-alpha-induced venular leukocyte rolling and extravascular recruitment. CONCLUSIONS: These results suggest that selectins mediate leukocyte infiltration and tissue damage in experimental colitis. Moreover, our data support the concept that functional interference with adhesion molecules of the selectin family may have a beneficial effect in the treatment of inflammatory bowel disease.     

狼疮性肾炎肾组织CD80与CD86的表达及其意义

目的 研究T淋巴细胞活化分子CD80与CD86在狼疮性肾炎患者肾组织中的表达变化及其与临床指标之间的相关性.方法 肾组织标本来源于2004年12月-2008年10月哈尔滨医科大学附属第一医院住院患者,其中女性44例,男性5例,年龄(28±16)岁.用免疫组织化学法检测狼疮性肾炎及微小病变患者肾组织中的CD80与CD86的表达情况,免疫比浊法检测24 h尿蛋白定量,全自动生化分析仪检测血尿素氮、血肌酐及血浆白蛋白等临床指标.结果 CD80在肾小管上皮细胞、肾间质有阳性表达,在肾小球无表达,而CD86在肾小管上皮细胞、肾间质及肾小球均有表达.CD80与CD86在肾小管间质中的表达水平随着狼疮性肾炎患者肾小管间质病变程度的加重而增强(r=0.574,P<0.001;r=0.534,P<0.001),且CD80的表达与CD86的表达成正相关.CD80与CDB6的表达与患者系统性红斑狼疮疾病活动指数积分(r=0.319,P=0.011;r=0.324,P=0.011)、24 h尿蛋白定量(r=0.424,P=0.003;r:0.408,P=0.004)、肌酐清除率(r=-0.535,P=0.000;r=-0.543,P=0.000)及抗dsDNA抗体滴度(r=0.353,P=0.012;r=0.359,P=0.013)具有明显相关性.结论 CD80与CD86在狼疮性肾炎患者肾组织中的表达水平与肾间质病变具有明显相关性,并且与狼疮性肾炎患者肾活检时的肾功能及活动性明显相关.     

Decreased leukocyte recruitment in the mesenteric microcirculation of rats with cirrhosis is partially restored by treatment with peginterferon: an in vivo study

BACKGROUND/AIMS: Patients with liver cirrhosis are predisposed to develop bacterial infections. An essential process in inflammatory responses is the recruitment of circulating leukocytes through the activation of adhesion molecules. Interferon-alpha2a is a cytokine reported to influence the expression of adhesion molecules. We investigated the effect of peginterferon-alpha2a (PegIFN-alpha(2a)) in vivo on the leukocyte recruitment in the mesenteric microcirculation of cirrhotic rats after lipopolysaccharide exposure. METHODS: Leukocyte rolling, adhesion and extravasation were visualized by intravital microscopy in sham-operated and common bile duct ligated (CBDL) rats. PegIFN-alpha(2a) was administered to influence leukocyte recruitment. Endothelial P-selectin, E-selectin and ICAM-1 expression were studied by immunohistochemistry. RESULTS: CBDL placebo rats showed significantly impaired rolling, adhesion and extravasation of leukocytes compared to Sham-operated placebo rats. Endothelial P-selectin, E-selectin and ICAM-1 expressions in CBDL placebo rats were significantly reduced compared to Sham-operated placebo rats. PegIFN-alpha(2a) 18 microg normalized number of rolling leukocytes in CBDL rats, without influencing on adhering and extravasated leukocytes. PegIFN-alpha(2a) upregulates the expression of P-selectin and E-selectin in CBDL rats, but ICAM-1 expression remained significantly lower than in Sham rats. CONCLUSIONS: Leukocyte recruitment is significantly impaired in the mesenteric microcirculation of cirrhotic rats. This deficiency appears to result from a reduced endothelial P-selectin, E-selectin and ICAM-1 expression. Peginterferon-alpha(2a) treatment normalizes rolling of leukocytes in cirrhotic rats by upregulation of P-selectin and E-selectin expressions, but has no influence on adhesion and extravasation possibly due to the absence of effect on ICAM-1 expression.     

Activation of vascular adhesion protein-1 on liver endothelium results in an NF-kappaB-dependent increase in lymphocyte adhesion

Vascular adhesion protein-1 (VAP-1) is an adhesion molecule and amine oxidase that is expressed at high levels in the human liver. It promotes leukocyte adhesion to the liver in vivo and drives lymphocyte transmigration across hepatic sinusoidal endothelial cells in vitro. We report that in addition to supporting leukocyte adhesion, provision of specific substrate to VAP-1 results in hepatic endothelial cell activation, which can be abrogated by treatment with the enzyme inhibitor semicarbazide. VAP-1-mediated activation was rapid; dependent upon nuclear factor-kappaB, phosphatidylinositol-3 kinase, and mitogen-activated protein kinase pathways; and led to upregulation of the adhesion molecules E-selectin, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 and secretion of the chemokine CXCL8. This response resulted in enhanced lymphocyte adhesion, was restricted to hepatic endothelial cells that expressed VAP-1, and was not observed in human umbilical vein endothelial cells. Conclusion: We propose that as well as directly promoting adhesion via interactions with the as yet unknown ligand, binding of enzyme substrate to VAP-1 can indirectly promote inflammatory cell recruitment via upregulation of adhesion molecules and chemokines. This response is likely to be important for the recruitment of leukocytes to the liver and suggests that VAP-1 inhibitors have therapeutic potential for treating chronic inflammatory liver disease.