IL-12 directs severe renal injury,crescent formation and Th1 responses in murine glomerulonephritis

Glomerular crescent formation characterizes severe glomerulonephritis (GN). Evidence suggests that crescent formation results from a delayed-type hypersensitivity-like Th1 response. As IL-12 directs Th1 responses, we tested the hypothesis that IL-12 is important in crescentic GN. Neutralization of IL-12 attenuated crescent formation and cell-mediated injury in C57BL/6 mice sensitized to and challenged with sheep anti-mouse glomerular basement membrane (GBM) globulin. Recombinant IL-12 induced severe crescentic GN with enhanced Th1 responses in C57BL/6 mice in which non-crescentic GN was induced by injecting anti-GBM globulin into naive mice. BALB/c mice do not develop significant crescent formation in these models, due either to regulatory effects of IL-4, or to deficits in IL-12 production/responsiveness. Administering IL-12 to BALB/c mice with GN induced Th1 responses and crescent formation, whereas IL-4-deficient BALB/c mice did not develop cell-mediated crescentic injury when GN was induced in sensitized mice. These results establish a central role for IL-12 in severe crescentic GN.     

抗中性粒细胞胞浆抗体在肾小球疾病中的检测及临床意义

目的 观察抗中性粒细胞胞浆抗体(ANCA)在不同肾小球疾病中的发生情况、间接免疫荧光模式和靶抗原特点，并初步探讨ANCA在肾小球疾病中的临床意义。方法 用间接免疫荧光(IIF—ANCA)法测定150例健康供血员和252例各种原、继发肾小球疾病患者的血清，阳性者(≥1：20)进一步检测蛋白酶3(PR3)、髓过氧化物酶(MPO)、乳铁蛋白(LF)特异性酶联免疫吸附(ELISA—ANCA)。252例患者中182例行肾活检。结果 正常对照组150例无1例ANCA阳性，病例组252例中12例血清ANCA阳性，其中C—ANCAl例，atypicaL-ANCAl例，P—ANCAl0例，识别MP0、LF及其他未测抗原，无1例识别PR3；各肾小球疾病中的ANCA的阳性率0％一17％，继发性肾小球疾病以狼疮性肾炎阳性率最高(17％)；病理分布于中重度系膜增生性IgA肾病、局灶坏死性紫癜性肾炎、弥漫增殖型狼疮性肾炎等。结论 ANCA在各肾小球疾病中的发生率约5％，不同疾病中的发生率不同，继发性，肾小球疾病中以狼疮性，肾炎阳性率最高；间接免疫荧光模式以P—ANCA、atyPical—ANCA多见，而C—ANCA少见；靶抗原以MPO、LF多见，而PR3少见；ANCA阳性对狼疮性肾炎、紫癜性肾炎、乙肝病毒相关性肾炎的临床鉴别诊断具有重要参考价值，对相关疾病的治疗及预后具有指导意义。     

用MTT法测定内毒素对培养人肾小球内皮细胞的损伤作用

目的；研究内毒素对人肾小球内皮细胞（ＨＧＶＥＣ）活力的影响，探讨内毒素在烧伤早期损害中的作用。方法：分离人肾小球内皮细胞，把细胞分为正常培养组，内毒素浓度梯度组，内毒素时间梯度组，无血清内毒素作用ＨＧＶＥＣ１２ｈ组，另设烧伤血清时间梯度组为阳性，用ＭＴＴ法测定经内毒素和烧伤血清刺激后ＨＧＶＥＣ活力变化。结果：１μｇ／ｍｌ以上内毒素即可引起ＨＧＶＥＣ活力降低（Ｐ〈０．０１），１μｇ／ｍｌＬＰＳ时间梯     

Projection neurons originating from thermo- and hygrosensory glomeruli in the antennal lobe of the cockroach

Most insects are equipped with specialized thermo- and hygroreceptors to locate a permissible range of ambient temperature and distant water sources, respectively. In the cockroach, Periplaneta americana, cold, moist, and dry receptor cells in the antennae send axons to particular sets of two or three glomeruli in the dorsocentral part of the antennal lobe (primary olfactory center), designated DC1-3 glomeruli. However, it is not known how thermo- and hygrosensory signals from these glomeruli are represented in higher-order centers, the protocerebrum, in any insect species. With the use of intracellular recording and staining techniques, we identified a new class of interneurons with dendrites almost exclusively in the DC1, DC2, or DC3 glomeruli and axons projecting to the protocerebrum in the cockroach. Remarkably, terminals of all these projection neurons (PNs) covered almost identical areas in the lateral protocerebrum (LP), although their termination areas outside the LP differed from neuron to neuron. The termination areas within the LP were distinct from, but close to, those of uniglomerular and macroglomerular PNs that transmitted signals concerning general odors and female sex pheromones, respectively. PNs originating from DC1, DC2, and DC3 glomeruli exhibited excitatory responses to cold, moist, and dry stimuli, respectively, probably due to excitatory synaptic input from cold, moist, and dry receptor cells, respectively, whereas their responses were often modulated by olfactory stimuli. These findings suggested that dorsocentral PNs participate in neural pathways that lead to behavioral responses to temperature or humidity changes.     

Inhibitory circuitry involving Y cells and Y retinal terminals in the C laminae of the cat dorsal lateral geniculate nucleus

We previously established (Datskovskaia et al. [2001] J Comp Neurol 430:85-100) that roughly 40% of Y retinal terminals contact interneurons in the A lamina of the dorsal lateral geniculate nucleus (dLGN) of the cat. However, we did not establish whether the dendritic terminals of interneurons postsynaptic to Y retinal terminals subsequently contact Y thalamocortical cells. To begin to address this issue, we examined the synaptic targets of Y retinal terminals in the magnocellular C lamina of the dLGN, which is populated almost exclusively by Y thalamocortical cells and interneurons. We utilized material generated from our previous work, in which we injected the superior colliculus with biotinylated dextran amine to backfill the geniculate branches of Y retinogeniculate axons in the dLGN. Sections prepared for electron microscopy were stained for gamma aminobutyric acid (GABA) to distinguish interneurons from thalamocortical cells. We found that the majority of profiles postsynaptic to Y retinal axons were the GABA-negative dendrites of thalamocortical cells (116/200, 58%). The remainder were GABA-positive dendrites of interneurons (84/200, 42%), many of which contained vesicles (F2 profiles; 54/200, 27%). In addition, we examined the synaptic targets of F2 profiles and found that almost all contacts of F2 profiles in the magnocellular C lamina were made onto the GABA-negative dendrites of thalamocortical cells (199/200, 99.5%). Thus, Y retinogeniculate axons contact interneurons and interneurons contact Y thalamocortical cells in the magnocellular C lamina of the dLGN. This indicates that interneurons are involved in modulation of the Y pathway.     

Comparison of the ultrastructure of cortical and retinal terminals in the rat dorsal lateral geniculate and lateral posterior nuclei

We compared the ultrastructure and synaptic targets of terminals of cortical or retinal origin in the rat dorsal lateral geniculate nucleus (LGN) and lateral posterior nucleus (LPN). Following injections of biotinylated dextran amine (BDA) into cortical area 17, two types of corticothalamic terminals were labeled by anterograde transport. Type I terminals, found throughout the LGN and LPN, were small, drumstick-shaped terminals that extended from thin axons. At the ultrastructural level in both the LGN and LPN, labeled type I corticothalamic terminals were observed to be small profiles that contained densely packed round vesicles (RS profiles) and contacted small-caliber dendrites. In tissue stained for gamma amino butyric acid (GABA) using postembedding immunocytochemical techniques, most dendrites postsynaptic to type I corticothalamic terminals did not contain GABA (97%). Type II corticothalamic terminals, found only in the LPN, were large terminals that sometimes formed clusters. At the ultrastructural level, type II terminals were large profiles that contained round vesicles (RL profiles) and contacted large-caliber dendrites, most of which did not contain GABA (98%). Retinogeniculate terminals, identified by their distinctive pale mitochondria, were similar to type II corticothalamic terminals except that 26% of their postsynaptic targets were vesicle-containing profiles that contained GABA (F2 profiles). Our results suggest that type I corticothalamic terminals are very similar across nuclei but that the postsynaptic targets of RL profiles vary. Comparison of the responses to retinal inputs in the LGN and to layer V cortical inputs in the LPN may provide a unique opportunity to determine the function of interneurons in the modulation of retinal signals and, in addition, may provide insight into the signals relayed by cortical layer V.     

Neurotrophin-3 is expressed in a discrete subset of olfactory receptor neurons in the mouse

In transgenic neurotrophin-3 lacZ-neo (NT-3(lacZneo)) mice, in which the coding region for NT-3 is replaced by Eschericia coli lacZ, the expression of beta-galactosidase faithfully mimics the expression of NT-3 (Vigers AJ, Baquet ZC, Jones KR [2000], J Comp Neurol 416:398-416). During embryonic and early postnatal development, beta-galactosidase is detected in the olfactory system, beginning at embryonic day 11.5 in the nasal epithelium and at embryonic day 16.5 in the olfactory bulb. Levels of beta-galactosidase rise with age, reaching a peak during the second postnatal week, when beta-galactosidase reactivity is visible in up to 50% of the glomeruli. As the animal matures, the beta-galactosidase levels decline, but staining remains present in axons and cell bodies of a specific subset of olfactory receptor neurons (ORNs) projecting to a limited subset of glomeruli. The heavily labeled ORNs do not follow the typical OR expression zones in the epithelium but appear similar to the "patch" expression pattern of mOR37 receptors. The most heavily reactive glomeruli exhibit a striking reproducible pattern in the ventral olfactory bulb (OB). Some glomeruli of the OB contain calcitonin gene-related peptide (CGRP)-immunoreactive fibers of the trigeminal nerve. However, double-label immunocytochemistry for CGRP and beta-galactosidase rendered no correlation between trigeminal innervation and the degree of innervation by NT-3-expressing ORNs. Thus, the timing and presence of beta-galactosidase in a subset of ORNs suggests that NT-3 plays a role in synaptogenesis and/or synapse function in a specific subset of ORNs within the olfactory bulb.     

12-脂氧化酶对系膜细胞血管紧张素Ⅱ1型受体表达的影响

目的 探讨12-脂氧化酶(12-LO)对系膜细胞血管紧张素(Ang)Ⅱ1型受体(AT1R)表达的影响。方法 用AngⅡ刺激正常和12-LO基因敲除小鼠肾系膜细胞后，观察p38 MAPK活性和细胞外基质(ECM)蛋白的变化。用12-LO的作用产物12(S)-HETE刺激的系膜细胞、转染12-LO基因的系膜细胞和采用显微切割法从正常和12-LO基因敲除小鼠肾脏提取的肾小球来观察AT1R的表达。采用RT-PCR和Western印迹分别检测目标基因mRNA和蛋白的表达。结果 AngⅡ的刺激可诱导正常系膜细胞p38 MAPK活性和ECM蛋白表达增高。然而，AngⅡ的刺激不能诱导12-LO基因敲除小鼠系膜细胞p38 MAPK活性和ECM蛋白表达升高。剂量依赖性和时间依赖性实验结果表明12(S)-HETE刺激可引起系膜细胞AT1蛋白水平增高，且AT1R mRNA水平升高有统计学意义(P < 0.01)。敲除肾小球内12-LO基因可有效地降低AT1R mRNA的表达(P < 0.01)，转染12-LO基因至系膜细胞使AT1R蛋白和mRNA的表达明显增多(P < 0.01)。结论 12-LO可上调系膜细胞AT1R的表达。     

The structural relationship between mesangial cells and basement membrane of the renal glomerulus

Summary It has been shown by many studies that mesangial cell contraction exerts considerable influences on glonerular filtration dynamics. However, experimental findings about the geometrical changes within the glomerular tuft going along with mesangial cell contractions are lacking. This study analyzes the geometry of mesangial cells and their relationship to glomerular capillaries, especially to the glomerular basement membrane (GBM).By applying a new staining technique of unosmicated specimens for TEM, the cellular outlines of glomerular cells (mesangial, endothelial and epithelial) and the distribution of extracellular matrices can be more easily studied than in conventionally osmicated specimens. It became obvious that mesangial cells and the GBM are extensively connected with each other, either by direct attachments or indirectly by microfibrils. These connections are especially prominent mesangial angles, i.e. at sites where the GBM deviates from its pericapillary course and covers the mesangium. Thereby, the GBM is not only coupled to the mesangium out—via mesangial cell processes—also to the GBM at the opposing mesangial angle. It seems possible that contraction of mesangial cells can bring the GBM from opposing mesangial angles closer together. Therefore we conclude that the GBM and the contractile mesangial cells together establish a biomechanical unit capable of developing wall tension in glomerular capillaries and of changing the geometry of glomerular capillaries following mesangial contraction or relaxation.Fellow of the Alexander von Humboldt Foundation