阿托伐他汀对慢性肾衰竭大鼠肾小球内皮细胞功能的影响

 目的 探讨阿托伐他汀对慢性肾衰竭（chronic renal failure, CRF）大鼠肾小球内皮细胞功能的影响。方法 28只雄性SD大鼠随机分为假手术组（对照组）、慢性肾衰竭组（模型组）及8 mg·kg^-1·d^-1阿托伐他汀干预组（小剂量组）、16 mg·kg^-1·d^-1阿托伐他汀干预组（大剂量组）。采用分阶段5/6肾切除术制备大鼠慢性肾衰竭动物模型。干预组给予阿托伐他汀生理盐水灌胃,其余两组给予等量生理盐水灌胃。8周后检测各组大鼠肾功能,尿蛋白,血脂,肝功能和肌酸激酶的变化,并观察肾组织病理改变。用免疫组化检测肾小球CD34、CD31表达,用逆转录多聚酶链反应（RT-PCR）检测肾组织内皮素-1（endothelin-1, ET-1）、内皮型一氧化氮合酶（endothelial nitric oxide synthase, eNOS）和血管内皮生长因子(vascular endothelial growth factor, VEGF)mRNA的表达。结果 阿托伐他汀治疗组大鼠肾功能明显改善,表现为血肌酐（serum creatinine, Scr）、血尿素氮（blood urea nitrogen, BUN）和尿蛋白水平降低（P0.05）。与模型组比较,阿托伐他汀治疗能显著增加大鼠肾小球CD34、CD31的表达（P     

Olfactory sensory neuron-specific and sexually dimorphic expression of protocadherin 20

Olfactory sensory axons navigate from the nasal cavity to the olfactory bulb and sort from among 1,000 different odorant receptor-expressing types to converge upon the same two or three glomeruli. To achieve this task during development, it is likely that multiple classes of regulatory molecules, including cell adhesion molecules, are involved. Cell adhesion molecules have been shown to be important in controlling axon guidance, fasciculation, and synapse formation. To gain further understanding of the involvement of adhesion molecules in olfactory circuitry development, we examined the dynamic and cell type specific expression of a novel protocadherin, PCDH20, in the olfactory system. PCDH20 is specifically expressed in newly differentiated olfactory sensory neurons and their axons during development. PCDH20 expression is down-regulated in the adult olfactory system, except in a small olfactory sensory neuron population. These small, discrete numbers of PCDH20-positive glomeruli in the adult olfactory bulb are consistently clustered in the ventral-caudal region in both male and female mice. However, adult males have higher numbers of PCDH20-positive glomeruli with a broader distribution, whereas adult females have fewer PCDH20-positive glomeruli with a more restricted distribution. The gender difference in PCDH20 expression may reflect olfactory receptor expression differences for gender-specific social discrimination.     

Increased expression and activity of phospholipase C in renal arterioles of young spontaneously hypertensive rats

BACKGROUND: The aims of this study were to document the presence of phospholipase C (PLC) isozymes beta(1), gamma(1), and delta(1) in freshly isolated renal glomeruli and resistance vessels, to compare their expression and activity to that in aorta, and to contrast values between 6-week-old Wistar-Kyoto (WKY) controls and 6-week-old spontaneously hypertensive rats (SHR) during the developmental phase of genetic hypertension. METHODS: Aorta, preglomerular arterioles, and glomeruli were isolated from 6-week-old rats using standard techniques. PLC isozyme protein level and activity were determined with Western blot analysis and by measuring inositol 1, 4, 5-trisphosphate (IP(3)) production, respectively. RESULTS: Immunoblots indicate that all three PLC isozymes examined are detectable in freshly isolated preglomerular arterioles, glomeruli, and aorta. Increased levels of PLC-beta(1), and -delta(1) were found in all tested vascular tissues of SHR v WKY. No strain difference was noted for PLC-gamma(1). The relative abundance for both groups was glomeruli > preglomerular arterioles = aorta. The strain difference in protein expression correlated with increased PLC activity in each vascular bed of SHR. CONCLUSIONS: Protein levels of PLC-beta(1) and -delta(1) and PLC activity are upregulated in the systemic and renal vasculature in 6-week-old SHR, suggesting a role in exaggerated vascular reactivity during the development of genetic hypertension. A more complete understanding of the physiologic roles of PLC isozymes and their contributions to specific aspects of cellular function should advance our understanding of vascular tone/reactivity and hypertrophy/remodeling in normal and hypertensive states.     

Microchimerism in renal allografts: clinicopathological associations according to the type of chimeric cells

Ferlicot S, Vernochet A, Romana S, Ortin‐Serrano M, Letierce A, Brégerie O, Durrbach A & Guettier C
(2010) Histopathology 56, 188–197 Microchimerism in renal allografts: clinicopathological associations according to the type of chimeric cells Aims: Recent studies have highlighted the presence of microchimerism in various solid allografts. The biological significance of these chimeric cells is controversial. They may be beneficial, leading to better tolerance of grafts or participating in tissue repair or, in contrast, deleterious if involved in chronic lesions. The aim was to assess the frequency and cellular nature of microchimerism in female renal grafts of male recipients by combined fluorescence in situ hybridization (FISH) for Y chromosome and immunohistochemistry and to investigate associations between intragraft microchimerism and histological lesions or allograft outcome. Methods and results: We screened 33 renal biopsy specimens, including 11 with acute T‐cell‐mediated rejection and nine with transplant glomerulopathy, from 22 male recipients transplanted with female kidneys by FISH and immunohistochemistry with antibodies against smooth muscle actin (mesangial cells), CD31 (endothelial cells), KL1 (epithelial cells), CD45 (leucocyte common antigen) and glomerular epithelial protein 1 (podocytes). Tubular microchimerism was detected in 71% of the patients with a mean percentage of chimeric epithelial cells of 1.4%. Glomerular microchimerism involving podocytes, mesangial and endothelial cells was present with a mean number of chimeric cells per glomerular section of, respectively, 0.6, 2.66 and 3.53. There was an association between endothelial microchimerism and a previous episode of acute T‐cell‐mediated rejection. Conclusions: In conclusion, microchimerism in renal grafts occurs frequently, but at a low level and affects tubular cells and all glomerular cell compartments in human renal allografts.     

Effects of advanced glycosylation endproducts on perlecan core protein of glomerular epithelium

Perlecan is one of major heparan sulfate proteoglycans in the glomerular basement membrane and is reduced in the renal parenchyma of diabetic patients and animals with proteinuria. To examine the effects of glucose and advanced glycosylated end-products (AGE) on perlecan, we cultured rat glomerular epithelial cells (GEpC) on AGE- or bovine serum albumin (BSA)-coated plates under normal (NG, 5 mM) and high-glucose (HG, 30 mM) conditions and measured the change in perlecan core protein production by a sandwich ELISA and northern blot analysis. We observed significant decreases of perlecan core protein under HG conditions at 1 week incubation, specifically on the AGE-coated compared with the BSA-coated surface, by 22.2% and 4.7%, respectively. The expression of mRNA for perlecan promoter was decreased under HG conditions on AGE-coated surfaces by 19.7% at 2 days and 61.1% at 1 week. Even under NG condition, the expression of mRNA was reduced by 30% at 1 week if GEpC were grown on an AGE-coated surface. In conclusion, HG and AGE have an additive effect in reducing the production of perlecan core protein by GEpC in vitro. AGE had a greater effect than HG, implying that the inhibition of AGE formation may be more effective than short-term glucose control in the prevention of diabetic proteinuria.     

Changes in reelin expression in the mouse olfactory bulb after chemical lesion to the olfactory epithelium

To explore the functional roles of Reelin in the adult olfactory system, we examined changes in the expression of reelin mRNA and Reelin protein in the olfactory bulb (OB) of adult mice after a chemical lesion to the olfactory epithelium. Following intranasal irrigation with 2% zinc sulphate solution, animals were perfused at various times between 5 and 40 days post-lesion. The expression of reelin mRNA in mitral cells in the OB was slightly reduced at 5 days post-lesion, completely abolished by 20 days, but restored almost to the normal level at 40 days post-lesion. Similarly, the expression of Reelin protein in mitral cells of the deafferented OB also recovered, although not to the normal level. No recovery of either reelin mRNA or Reelin immunoreactivity was seen in the periglomerular cells and external tufted cells. The expression profile of reelin mRNA and Reelin protein in the OB coincided with the time course of degeneration and regeneration of olfactory nerves, as indicated by anterograde labeling of olfactory nerves with WGA-HRP. These results suggest that expression of reelin mRNA in the adult OB is regulated by olfactory inputs.     

Olfactory marker protein modulates primary olfactory axon overshooting in the olfactory bulb

Olfactory marker protein (OMP) is expressed by mature primary olfactory sensory neurons during development and in adult mice. In mice that lack OMP, olfactory sensory neurons have perturbed electrophysiological activity, and the mice exhibit altered responses and behavior to odor stimulation. To date, defects in axon guidance in mice that lack OMP have not been investigated. During development of the olfactory system in mouse, primary olfactory axons often overshoot their target glomerular layer and project into the deeper external plexiform layer. These aberrant axonal projections are normally detected within the external plexiform layer up to postnatal day 12. We have examined the projections of primary olfactory axons in OMP-tau:LacZ mice and OMP-GFP mice, two independent lines in which the OMP coding region has been replaced by reporter molecules. We found that axons overshoot their target layer and grow into the external plexiform layer in these OMP null mice as they do in wild-type animals. However, in the absence of OMP, overshooting axons are more persistent and remain prominent until 5 weeks postnatally, after which their numbers decrease. Overshooting axons are still present in these mice even at 8 months of age. In heterozygous mice, axons also overshoot into the external plexiform layer; however, there are fewer axons, and they project for shorter distances, compared with those in a homozygous environment. Our results suggest that perturbed electrophysiological responses, caused by loss of OMP in primary olfactory neurons, reduce the ability of primary olfactory axons to recognize their glomerular target.     

Expression of the neuronal calcium sensor protein NCS-1 in the developing mouse olfactory pathway

Neuron specific calcium sensor 1 (NCS-1) is widely expressed in the developing and adult nervous system. Like calmodulin, NCS-1 is a member of a family of calcium binding proteins that contain EF-hand motifs, which bind calcium and induce conformational changes in the protein. Their binding varies with calcium concentration, allowing them to act as true calcium sensors rather than just calcium binding proteins. This family of proteins has been implicated in important synaptic events including neurotransmitter release and synapse formation. We examined the expression of NCS-1 in the developing and mature olfactory system to determine whether this molecule may be playing a role in establishing and/or maintaining olfactory circuitry. During development, expression of NCS-1 in the olfactory epithelium was localized in the dendritic knobs and axons of olfactory sensory neurons. Axonal expression was down-regulated after synapse formation. In the developing olfactory bulb, NCS-1 was expressed in the processes of mitral/tufted and granule cells. However, in the adult olfactory bulb, strongest expression was found in a subset of periglomerular cells (PGCs). This subset of PGCs did not express other known markers of PGCs including tyrosine hydroxylase, glutamic acid decarboxylase, calbindin, or calretinin, and only partially overlapped with the subpopulation of PGCs that express parvalbumin. Together, these data suggest multiple and overlapping roles of NCS-1 in the developing and mature olfactory system.     

Pheromone processing center in the protocerebrum of Bombyx mori revealed by nitric oxide-induced anti-cGMP immunocytochemistry

The antennal lobe (AL) of the male silkworm moth Bombyx mori contains 60 +/- 2 ventrally located antennal glomeruli and a dorsal macroglomerular complex (MGC) consisting of three subdivisions. The response patterns of MGC projection neurons (PNs) to pheromonal stimuli correlate with their dendritic arborization in the subdivisions of the MGC. However, the representation of this pheromonal information in the lateral protocerebrum (LPC), which is the target site of the AL PNs, is not well known. We performed nitric oxide (NO)-induced anti-cGMP immunohistochemistry and found that the PNs which respond to the major pheromone component (bombykol) express strong immunoreactivity. They project to a specific area, the delta area in the inferior lateral protocerebrum (DeltaILPC), which clearly represents the processing center for the major pheromone component. Furthermore, to examine the projection sites in the LPC from each subdivision of the MGC, we performed double-labeling of each type of MGC-PNs, combined with NO-induced anti-cGMP immunohistochemistry. We revealed that projections from each subdivision of the MGC overlapped or separated in specific regions of the DeltaILPC. These results suggest that integration and segregation of pheromone information may occur in the DeltaILPC.     

热休克蛋白27/转录激活因子5复合物在高糖诱导足细胞凋亡中的意义

目的研究足细胞内热休克蛋白27(HSP27)是否与转录激活因子5(ATF5)形成复合物及其在足细胞凋亡中的意义。方法高糖刺激体外培养的小鼠肾小球足细胞系建立细胞凋亡模型,应用Hochest染色、流式细胞技术测定细胞凋亡。应用Western印迹分析技术检测丝裂原活化蛋白激酶(MAPK)信号途径的活化,应用免疫共沉淀技术检测HSP27和ATF5形成复合物的变化,阻断实验观察MAPK信号途径对高糖调节足细胞HSP27与ATF5形成复合物以及足细胞凋亡的影响。结果成功建立了高糖刺激足细胞凋亡的模型,30mmol/L高糖刺激48h凋亡率(27.2%±8.9%)显著高于5.5mmol/L正常糖(对照)48h组(10.6%±2.7%,P<0.05)。正常糖(对照)组细胞HSP27与ATF5即可形成复合物,而在高糖刺激12hHSP27与ATF5形成的复合物明显增加为正常糖组的195%±36%(P<0.05)。高糖刺激30min即可使细胞外信号调节激酶(ERK1/2)和p38活化。进一步阻断实验显示ERK1/2活化抑制剂可以减弱高糖刺激引起HSP27和ATF5形成复合物的效应(PD98059+高糖组为109%±19%,高糖组211%±46%,P<0.05),同时加重高糖诱导细胞凋亡(PD98059+高糖组凋亡率为51%±4%,高糖组凋亡率为27%±9%)(P<0.05)。p38活化抑制剂不影响高糖刺激引起的HSP27和ATF5形成复合物(SB20358+高糖组为290%±43%,高糖组为231%±20%,P>0.05),但可减轻高糖诱导细胞凋亡(SB20358+高糖组凋亡率为16%±6%,高糖组凋亡率为27%±9%)(P<0.05)。结论高糖依赖ERK1/2信号通路而不是p38信号通路刺激足细胞HSP27与ATF5形成复合物的增加,蛋白复合物可能在高糖诱导的足细胞凋亡中起保护作用。