5 /6 肾切除小鼠中矿物质与骨代谢紊乱的特征

摘要: 目的通过制备5 /6 肾切除( 5 /6 Nx) 小鼠慢性肾脏病( CKD) 模型,观察小鼠成纤维生长因子23( FGF23) 及钙磷代谢指标,有助于研究矿物质与骨代谢紊乱的发病机制。方法28 只C57 雄性小鼠适应性饲养1 周后,切除模型组约5 /6 左肾,1周后切除右肾, 16 周后处死后收集血尿和肾脏组织标本,常规检测血尿FGF23、甲状旁腺素( PTH) 、活性维生素D、钙、磷等指标,观察肾脏病理。结果与假手术组和正常对照组相比,术后16 周5 /6 Nx 小鼠出现体质量减低,血清FGF23、PTH,血磷等异常升高,活性维生素D 水平显著降低,尿蛋白增加。肾脏病理发现系膜基质增生、胶原沉积及纤维化明显,和肾小球代偿性肥大。结论5 /6 Nx 小鼠可以出现明显的矿物质与骨代谢紊乱特征,是研究CKD 骨病合适的模型。     

骨质疏松患者FGF23与Crosslaps血清浓度检测与分析

目的:探讨骨质疏松症(Osteoporosis,OP)患者外周血成纤维生长因子23(Fibrobalst growth factor-23,FGF23)、Ⅰ互型胶原交联C末端肽(Crosslaps)与25-(OH)D代谢水平与骨质疏松症的关系.方法:选择骨质疏松女性患者32名,年龄48~90岁(OP组),与21名健康人年龄31~50岁(对照组).采用酶联免疫吸附法检测外周血FGF23,Crosslaps及25-(OH)D水平.采用全自动血液生化分析仪检测血钙、血清无机磷、碱性磷酸酶(Alkaline phosphates,ALP)水平,并对OP患者25-(OH)D与FGF23、Crosslaps、血钙、血磷的相关性进行分析.对53名受试者进行骨密度(Bone mineral density,BMD)测量及医学影像学检测.采集OP患者及健康人股骨骨样进行石蜡包埋、切片、HE染色并观察,采用病理学图像分析系统进行形态计量学分析.结果:与对照组比较,OP组患者血清中FGF23、Crosslaps水平显著升高(P0.05);OP患者血清中25-(OH)D水平与FGF23相关系数为-0.012 2,与Crosslaps相关系数为-0.231 7;通过骨组织形态计量学分析,OP患者骨小梁平均厚度、骨小梁面积百分率较对照组显著减少(P0.05),OP组骨小梁间距较对照组显著增大(P0.05).OP患者左侧股骨颈(Femeralneck,FN),Ward's三角(Ward's)骨密度值与对照组均有显著减少(P0.05).通过影像学检测发现OP组X光片透光度有所增加,骨小梁变细,骨皮质变薄.结论:骨质疏松症患者血清中FGF23,Crosslaps因子水平与25-(OH)D水平存在一定相关性.提示其在骨代谢所引起的血清水平变化,以及三者之间的关系可为骨质疏松症的诊断和治疗提供参考.     

蒲滑散对实验大鼠慢性肾衰的作用研究

目的 研究蒲滑散对大鼠慢性肾衰的作用。方法 采用Platt法诱发慢性肾衰大鼠模型,观察蒲滑散对血肌酐(Scr)、尿素氮(BUN)、血钙(Ca)、血磷(P)、甲状旁腺素(PTH)、中分子物质(MMS)的作用及肾脏病理学改变。结果 蒲滑散可明显改善大鼠肾脏病变,恢复肾脏功能,纠正高磷低钙血症,抑制PTH和MMS。结论 蒲滑散是治疗尿毒症的有效方药之一,其改善患者的临床症状与降低慢性肾功能衰竭(CRF)毒素潴留有关。     

不同血液净化方式对维持性血液透析患者骨及矿物质的影响

探讨不同血液净化方式对维持性血液透析患者骨及矿物质代谢的影响。选择维持性血液透析患者42例,随机分为3组:HD(普通血液透析)组、HFHDF(高通量血液透析滤过)组、HFHD(高通量血液透析)组,各14例,透析治疗12周,分别测定3组患者治疗前后的血钙、血磷、甲状旁腺激素水平。治疗前,3组患者的血钙、血磷及甲状旁腺激素均无统计学意义(P0.05),具有可比性。透析治疗12周后,与治疗前比较,HD组血磷、甲状旁腺激素无统计学意义(P0.05),HFHDF组和HFHD组血磷、甲状旁腺激素均有统计学意义(P0.05),但HFHDF组和HFHD组组间比较无统计学意义(P0.05)。高通量血液透析及高通量血液透析滤过能够明显改善尿毒症患者的骨及矿物质代谢。     

不同分期慢性肾脏疾病患者血清检测指标对其治疗和预后临床价值的探讨

探讨不同分期慢性肾脏疾病(chronic kidney disease, CKD)患者血清检测指标对其诊断、治疗以及并发症防治的应用价值.采用化学发光法和免疫比浊法检测血清尿素、肌酐、尿酸、胱抑素C、视黄醇结合蛋白和人附睾蛋白4,分析不同分期CDK患者血清指标与CDK分期的关系,采用SPSS软件分析各指标与HE4的相关性.不同分期CKD患者,血清尿素和肌酐各组之间具有明显差异.尿酸结果发现,CKD 5、CKD 4和CKD 3组与CKD 1-2组相比具有差异,但CKD 5、CKD 4和CKD 3各组之间比较无差异.不同分期CKD患者血清胱抑素C和视黄醇结合蛋白也具有明显差异;且随着分期越高,血清各项检测指标越高.不同分期CKD患者血清HE4表达水平具有明显差异,且不同分期之间具有统计学意义;且随着慢性肾病分期越高,患者血清HE4水平也越高.不同分析CKD患者血清HE4与尿素,肌酐,尿酸,胱抑素C、视黄醇结合蛋白和PTH之间的相关性分析发现,血清HE4与UREA、CREA、CysC、RBP和PTH均相关,其相关系数和95%CI分别为0.741 4(0.66～0.80)、0.826 7(0.77～0.87)、0.849 0(0.80～0.89)、0.643 7(0.54～0.73)和0.436 0(0.28～0.57).但血清HE4与UA相关性较差,其相关系数和95%CI为0.204 3(0.04～0.35). HE4与CREA对慢性肾病分期具有相同的效能,尿素对慢性肾病分析的ROC曲线面积为0.971 2,胱抑素C对慢性肾病分析的ROC曲线面积为0.903 7. HE4可以作为CKD分期辅助诊断指标之一,GFR联合HE4可以更好地知道CKD的分期.血清PTH可以作为CKD患者肾脏疾病-矿物质-骨代谢异常并发症的监测指标.不同分期CDK患者血清学指标对疾病的诊断、治疗以及并发症的防治具有重要价值.     

二甲基精氨酸-二甲胺水解酶在疾病中的表达和功能

非对称性-二甲基精氨酸(ADMA)抑制一氧化氮合酶(NOS),是内皮功能损伤、心血管疾病和慢性肾脏疾病的危险因素.二甲基精氨酸-二甲胺水解酶(DDAH)可以代谢ADMA,主要分为两种.DDAH-1主要分布于肾小管、肝脏,从循环中摄取ADMA;DDAH-2主要存在于血管中,分布于内皮细胞胞膜交界处及胞内颗粒、血管平滑肌细胞肌纤维及核被膜中.DDAH的表达、调节和分布均具有特异性.可以特异地调节NO的产生.本文总结了DDAH在心血管疾病和肾脏疾病导致的内皮功能受损中所起的作用.     

通腑泄浊法对CKD模型大鼠肾功能及肠道屏障功能的影响

目的探讨通腑泄浊法对慢性肾脏病(CKD)模型大鼠肠道屏障功能的影响,初步探讨其延缓CKD进展的机理。方法应用5/6肾切除法构建CKD大鼠模型,SD雄性大鼠120只随机分为空白组,模型组,通腑泄浊组(高、中、低剂量),药用炭组,每组20只,从模型建立后开始灌肠,疗程4周,第4周末检测血清肌酐,血硫酸吲哚酚水平,观察肾组织病理结构变化。结果 CKD模型组大鼠肾组织可见肾小管上皮细胞变性、间质炎性细胞浸润、纤维组织增生等病理变化,通腑泄浊组与CKD模型组大鼠相比较均有不同程度的改善,其中以通腑泄浊高剂量组改善最为明显。通腑泄浊各剂量组和药用炭组血内毒素、D-乳酸含量明显下降(P0.05),且高剂量组比药用炭组下降更为明显(P0.05)。结论通腑泄浊法具有一定的保护肾脏和抗肾间质纤维化的作用,降低大鼠血内毒素、D-乳酸含量,保护肠粘膜屏障功能可能是其机制之一。     

可溶性血管内皮生长因子受体1在IgAN的研究进展

可溶性血管内皮生长因子受体1（soluble fms-like tyrosine kinase 1,sFlt-1）是已证实的内皮细胞损伤的分子标志物.sFlt-1在循环中结合VEGF（血管内皮生长因子）而调节其功能,拮抗VEGF的营养功能而导致内皮细胞损伤.有研究发现在慢性肾脏疾病（CKD ）患者中sFlt-1有明显升高,过量的sFlt-1与CKD内皮功能障碍有关.而IgAN是我国最常见的CKD,目前国内外缺乏关于sFlt-1在IgAN中的相关研究.sFlt-1与IgAN临床病理之间相关性的研究是一个全新的研究方向.研究sFlt-1与CKD特别是发病率很高的IgAN的相关性并应用其研究成果,对IgAN的诊断、治疗和判断预后是一个新的思路.     

痛风的种类及治疗

痛风是嘌呤代谢紊乱和(或)尿酸排泄障碍所导致的血尿酸增高的一组异质性疾病，其特指急性特征性关节炎和慢性痛风石疾病，重者可出现关节破坏，晚期可并发肾脏病变、肾功能受损，常伴发代谢综合征等表现。随着我国经济的不断发展，人民生活水平的不断提高，我国将逐步迈入老龄化社会。而在老年人中，痛风病是最为常见的疾病之一，该病的发病率也在呈现出逐年增高的态势，它给患者带来极大的痛苦，严重影响到患者的生活质量。所以说了解痛风的相关知识，掌握其种类及其治疗显得尤为重要。     

胃泌素、胃动素测定在胃肠疾病中的意义

<正> 胃泌素和胃动素测定临床已经应用于消化疾病的诊断,但迄今为止,这两种激素在胃肠的一些疾病,特别是胃、十二指肠粘膜病变的疾病中,到底起何作用仍不为临床所认同,各家报道亦不一致。我们测定了部分胃、十二指肠粘膜病变患者及正常人血中胃泌素(GAS)和胃动素(MTL)水平,以探讨GAS和MTL在胃肠疾病中的临床意义。     

Klotho converts canonical FGF receptor into a specific receptor for FGF23

FGF23 is a unique member of the fibroblast growth factor (FGF) family because it acts as a hormone that derives from bone and regulates kidney functions, whereas most other family members are thought to regulate various cell functions at a local level. The renotropic activity of circulating FGF23 indicates the possible presence of an FGF23-specific receptor in the kidney. Here we show that a previously undescribed receptor conversion by Klotho, a senescence-related molecule, generates the FGF23 receptor. Using a renal homogenate, we found that Klotho binds to FGF23. Forced expression of Klotho enabled the high-affinity binding of FGF23 to the cell surface and restored the ability of a renal cell line to respond to FGF23 treatment. Moreover, FGF23 incompetence was induced by injecting wild-type mice with an anti-Klotho monoclonal antibody. Thus, Klotho is essential for endogenous FGF23 function. Because Klotho alone seemed to be incapable of intracellular signalling, we searched for other components of the FGF23 receptor and found FGFR1(IIIc), which was directly converted by Klotho into the FGF23 receptor. Thus, the concerted action of Klotho and FGFR1(IIIc) reconstitutes the FGF23 receptor. These findings provide insights into the diversity and specificity of interactions between FGF and FGF receptors.     

Point mutation of an FGF receptor abolishes phosphatidylinositol turnover and Ca2+ flux but not mitogenesis.

Stimulation of certain receptor tyrosine kinases results in the tyrosine phosphorylation and activation of phospholipase C gamma (PLC gamma), an enzyme that catalyses the hydrolysis of phosphatidylinositol (PtdIns). This hydrolysis generates diacylglycerol and free inositol phosphate, which in turn activate protein kinase C and increase intracellular Ca2+, respectively. PLC gamma physically associates with activated receptor tyrosine kinases, suggesting that it is a substrate for direct phosphorylation by these kinases. Here we report that a fibroblast growth factor (FGF) receptor with a single point mutation at residue 766 replacing tyrosine with phenylalanine fails to associate with PLC gamma in response to FGF. This mutant receptor also failed to mediate PtdIns hydrolysis and Ca2+ mobilization after FGF stimulation. However, the mutant receptor phosphorylated itself and several other cellular proteins, and it mediated mitogenesis in response to FGF. These findings show that a point mutation in the FGF receptor selectively eliminates activation of PLC gamma and that neither Ca2+ mobilization nor PtdIns hydrolysis are required for FGF-induced mitogenesis.     

A PPARγ-FGF1 axis is required for adaptive adipose remodelling and metabolic homeostasis

Although feast and famine cycles illustrate that remodelling of adipose tissue in response to fluctuations in nutrient availability is essential for maintaining metabolic homeostasis, the underlying mechanisms remain poorly understood. Here we identify fibroblast growth factor 1 (FGF1) as a critical transducer in this process in mice, and link its regulation to the nuclear receptor PPARγ (peroxisome proliferator activated receptor γ), which is the adipocyte master regulator and the target of the thiazolidinedione class of insulin sensitizing drugs. FGF1 is the prototype of the 22-member FGF family of proteins and has been implicated in a range of physiological processes, including development, wound healing and cardiovascular changes. Surprisingly, FGF1 knockout mice display no significant phenotype under standard laboratory conditions. We show that FGF1 is highly induced in adipose tissue in response to a high-fat diet and that mice lacking FGF1 develop an aggressive diabetic phenotype coupled to aberrant adipose expansion when challenged with a high-fat diet. Further analysis of adipose depots in FGF1-deficient mice revealed multiple histopathologies in the vasculature network, an accentuated inflammatory response, aberrant adipocyte size distribution and ectopic expression of pancreatic lipases. On withdrawal of the high-fat diet, this inflamed adipose tissue fails to properly resolve, resulting in extensive fat necrosis. In terms of mechanisms, we show that adipose induction of FGF1 in the fed state is regulated by PPARγ acting through an evolutionarily conserved promoter proximal PPAR response element within the FGF1 gene. The discovery of a phenotype for the FGF1 knockout mouse establishes the PPARγ–FGF1 axis as critical for maintaining metabolic homeostasis and insulin sensitization.     

Functions of FGF signalling from the apical ectodermal ridge in limb development

To determine the role of fibroblast growth factor (FGF) signalling from the apical ectodermal ridge (AER), we inactivated Fgf4 and Fgf8 in AER cells or their precursors at different stages of mouse limb development. We show that FGF4 and FGF8 regulate cell number in the nascent limb bud and are required for survival of cells located far from the AER. On the basis of the skeletal phenotypes observed, we conclude that these functions are essential to ensure that sufficient progenitor cells are available to form the normal complement of skeletal elements, and perhaps other limb tissues. In the complete absence of both FGF4 and FGF8 activities, limb development fails. We present a model to explain how the mutant phenotypes arise from FGF-mediated effects on limb bud size and cell survival.     

Attenuation of FGF signalling in mouse beta-cells leads to diabetes

Fibroblast growth factor (FGF) signalling has been implicated in patterning, proliferation and cell differentiation in many organs, including the developing pancreas. Here we show that the FGF receptors (FGFRs) 1 and 2, together with the ligands FGF1, FGF2, FGF4, FGF5, FGF7 and FGF10, are expressed in adult mouse beta-cells, indicating that FGF signalling may have a role in differentiated beta-cells. When we perturbed signalling by expressing dominant-negative forms of the receptors, FGFR1c and FGFR2b, in the pancreas, we found that that mice with attenuated FGFR1c signalling, but not those with reduced FGFR2b signalling, develop diabetes with age and exhibit a decreased number of beta-cells, impaired expression of glucose transporter 2 and increased proinsulin content in beta-cells owing to impaired expression of prohormone convertases 1/3 and 2. These defects are all characteristic of patients with type-2 diabetes. Mutations in the homeobox gene Ipf1/Pdx1 are linked to diabetes in both mouse and human. We also show that Ipf1/Pdx1 is required for the expression of FGFR1 signalling components in beta-cells, indicating that Ipf1/Pdx1 acts upstream of FGFR1 signalling in beta-cells to maintain proper glucose sensing, insulin processing and glucose homeostasis.     

梅花鹿FGF10基因的生物信息学分析

应用生物信息学的方法对梅花鹿FGF10基因的核苷酸和氨基酸序列进行了初步的生物信息学分析,包括理化性质分析、信号肽和跨膜结构域分析、磷酸化位点和疏水性分析、蛋白质二级结构分析、功能结构域分析以及系统进化分析.结果表明:梅花鹿FGF10基因编码213个氨基酸,蛋白相对分子量为23.84kD,为碱性不稳定蛋白;存在信号肽和跨膜结构域;共有26个磷酸化位点;二级结构主要由α螺旋、β转角、延伸链和随机卷曲组成.具有FGF典型的FGF结构域.系统进化分析显示,梅花鹿FGF10与哺乳动物FGF10相似性较高,并且与牛、羊在亲缘关系上最相近.为梅花鹿FGF10基因的结构和功能的进一步研究打下了坚实的理论基础.     

Point mutation in FGF receptor eliminates phosphatidylinositol hydrolysis without affecting mitogenesis.

Stimulation of growth factor receptors with tyrosine kinase activity is followed by rapid receptor dimerization, tyrosine autophosphorylation and phosphorylation of signalling molecules such as phospholipase C gamma (PLC gamma) and the ras GTPase-activating protein. PLC gamma and GTPase-activating protein bind to specific tyrosine-phosphorylated regions in growth factor receptors through their src-homologous SH2 domains. Growth factor-induced tyrosine phosphorylation of PLC gamma is essential for stimulation of phosphatidylinositol hydrolysis in vitro and in vivo. We have shown that a short phosphorylated peptide containing tyrosine at position 766 from a conserved region of the fibroblast growth factor (FGF) receptor is a binding site for the SH2 domain of PLC gamma (ref. 8). Here we show that an FGF receptor point mutant in which Tyr 766 is replaced by a phenylalanine residue (Y766F) is unable to associate with and tyrosine-phosphorylate PLC gamma or to stimulate hydrolysis of phosphatidylinositol. Nevertheless, the Y766F FGF receptor mutant can be autophosphorylated, and can phosphorylate several cellular proteins and stimulate DNA synthesis. Our data show that phosphorylation of the conserved Tyr 766 of the FGF receptor is essential for phosphorylation of PLC gamma and for hydrolysis of phosphatidylinositol, but that elimination of this hydrolysis does not affect FGF-induced mitogenesis.