Age-related amyloidosis outside the brain: A state-of-the-art review

Inside and outside the brain, accumulation of amyloid fibrils plays key roles in the pathogenesis of fatal age-related diseases such as Alzheimer’s and Parkinson’s diseases and wild-type transthyretin amyloidosis. Although the incidence of all amyloidoses increases with age, for some types of amyloidosis aging is known as the main direct risk factor, and these types are typically diseases of elderly people. More than 10 different precursor proteins are known to cause age-associated amyloidosis; these proteins include amyloid β protein, α-synuclein, transthyretin, islet amyloid polypeptide, atrial natriuretic factor, and the newly discovered epidermal growth factor-containing fibulin-like extracellular matrix protein 1. Except for intracerebral amyloidoses, most age-related amyloidoses have been little studied. Indeed, in view of the increasing life expectancy in our societies, understanding how aging is involved in the process of amyloid fibril accumulation and the effects of amyloid deposits on the aging body is extremely important. In this review, we summarize current knowledge about the nature of amyloid precursor proteins, the prevalence, clinical manifestations, and pathogenesis of amyloidosis, and recent advances in our understanding of age-related amyloidoses outside the brain.     

纤维样肾小球病一例报道及文献复习

目的 通过对一例纤维样肾小球病(fibrillary glomerulopathy,FGP)患者的临床和病理资料进行分析,探讨其发病机制、临床表现、诊断、治疗及预后.方法 回顾性分析一例纤维样肾小球病患者的临床表现,并将患者肾穿刺组织进行光镜、免疫荧光、电镜检查,通过以上数据,并结合相关文献系统复习纤维样肾小球病的临床特征.结果 通过其临床表现,肾组织病理学检查,特别是电镜诊断本例为纤维样肾小球病.临床表现多为大量蛋白尿、镜下血尿和高血压等.电镜的检查结果是诊断纤维样肾小球病的主要依据.其主要特点是纤维样物质呈弥漫性或团块状分布于肾小球系膜区和(或)肾小球基底膜,排列紊乱,无规律,纤维僵直,一般无分支.该病预后差,大约50％的患者2～4年内进展为终末期肾脏疾病.结论 电镜结合刚果红染色是诊断纤维样肾小球病的重要方法,该病发病率较低,病理生理机制仍不清楚,预后不佳,目前缺乏较为有效的治疗措施.     

纤维蛋白原β启动子区单倍型对特发型下肢深静脉血栓的影响

目的 观察纤维蛋白原β(FGB)启动子区单倍型对特发型下肢深静脉血栓(IDVT)的影响.方法 IDVT组及健康对照组各120例.采用启动子区完整测序技术及聚合酶链反应-限制性片段长度多态性(PCR-RFLP)双重检测纤维蛋白原β链基因启动子区-1 420G/A、-993 C/T、-854G/A、-455 G/A、-249C/T和-148C/T单核苷酸多态性(SNP)及基因型,对上述SNP连锁不平衡分析并构建单倍型模型.结果-993 C/T与-455 G/A、-993 C/T与-148C/T、-455 G/A与-148C/T之间存在较强的连锁不平衡关系(r2分别为0.699、0.509和0.556);构建出8种单倍型模型:单倍型H3、H6在病例组中的频率高于对照组[比值比(OR)分别为32.085和1.896,P＜0.05];单倍型H1、H4、H5和H7在对照组中的频率高于病例组(OR值分别为0.025、0.119、0.644和0.383,P ＜0.05);其余单倍型(H2和H8)在两组之间差异无统计学意义(P＞0.05).结论 单倍型H3、H6可能是下肢深静脉血栓(DVT)的危险因素;单倍型H1、H4、H5和H7可能是DVT的保护因素.     

Antimicrobial barrier of an in vitro oral epithelial model

OBJECTIVE: Oral epithelia function as a microbial barrier and are actively involved in recognizing and responding to bacteria. Our goal was to examine a tissue engineered model of buccal epithelium for its response to oral bacteria and proinflammatory cytokines and compare the tissue responses with those of a submerged monolayer cell culture. DESIGN: The tissue model was characterized for keratin and beta-defensin expression. Altered expression of beta-defensins was evaluated by RT-PCR after exposure of the apical surface to oral bacteria and after exposure to TNF-alpha in the medium. These were compared to the response in traditional submerged oral epithelial cell culture. RESULTS: The buccal model showed expression of differentiation specific keratin 13, hBD1 and hBD3 in the upper half of the tissue; hBD2 was not detected. hBD1 mRNA was constitutively expressed, while hBD2 mRNA increased 2-fold after exposure of the apical surface to three oral bacteria tested and hBD3 mRNA increased in response to the non-pathogenic bacteria tested. In contrast, hBD2 mRNA increased 3-600-fold in response to bacteria in submerged cell culture. HBD2 mRNA increased over 100-fold in response to TNF-alpha in the tissue model and 50-fold in submerged cell culture. Thus, the tissue model is capable of upregulating hBD2, however, the minimal response to bacteria suggests that the tissue has an effective antimicrobial barrier due to its morphology, differentiation, and defensin expression. CONCLUSIONS: The oral mucosal model is differentiated, expresses hBD1 and hBD3, and has an intact surface with a functional antimicrobial barrier.     

Effects of transforming growth factor beta1 (TGFbeta-1) and dentin non-collagenous proteins (DNCP) on human embryonic ectomesenchymal cells in a three-dimensional culture system

Cranial neural crest-derived ectomesenchymal cells represent a population of pluripotent stem cells giving rise to many of the various oro-facial and dental tissues. The factors determining the terminal fate of these cells are still unclear. The potentiality of human embryonic ectomesenchymal cells from the first branchial arch have been investigated when isolated and grown in a three-dimensional (3D)-collagen gel culture system in the presence of dentin matrix-derived non-collagenous proteins (DNCP) and TGFbeta-1. Functional differentiation of cells showing some characteristics of odontoblast-like cells could be observed when the cells were cultured with DNCP+TGFbeta-1 or DNCP, however, only cytological differentiation was observed during culture with TGFbeta-1 alone. The characteristics of these cells was assessed by morphological appearance, expression of the odontoblast phenotype marker dentin sialophosphoprotein (DSPP), increased alkaline phosphatase levels and formation of mineralised nodules in vitro. The results indicate that these embryonic cells from the first branchial arch are capable of responding to the inductive stimulus of DNCP or DNCP+TGFbeta-1 when isolated and grown in the 3D collagen gel culture system. The capacity of the isolated cells to differentiate into mineralizing cells showing some characteristics of odontoblast-like cells under these growth conditions highlights the potential of such approaches for tissue engineering strategies for hard-tissue regeneration after injury.