Human mitochondrial tRNAs in health and disease

The human mitochondrial genome encodes 13 proteins, all subunits of the respiratory chain complexes and thus involved in energy metabolism. These genes are translated by 22 transfer RNAs (tRNAs), also encoded by the mitochondrial genome, which form the minimal set required for reading all codons. Human mitochondrial tRNAs gained interest with the rapid discovery of correlations between point mutations in their genes and various neuromuscular and neurodegenerative disorders. In this review, emerging fundamental knowledge on the structure/function relationships of these particular tRNAs and an overview of the large variety of mechanisms within translation, affected by mutations, are summarized. Also, initial results on wide-ranging molecular consequences of mutations outside the frame of mitochondrial translation are highlighted. While knowledge of mitochondrial tRNAs in both health and disease increases, deciphering the intricate network of events leading different genotypes to the variety of phenotypes requires further investigation using adapted model systems.Received 3 December 2002; received after revision 14 January 2003; accepted 27 January 2003     

丙二醛可用作神经退行性疾病进程的衡量指标

大量实证表明，自由基介导的氧化损伤与神经退行性疾病的发病机理相关。虽然丙二醛等不饱和醛酮作为氧化损伤指标的临床诊断价值不高，但实验证实它们在帕金森病、肌萎缩性侧索硬化病和阿尔茨采姆病等几种神经退行性疾病的机体组织中普遍增加。丙二醛测定方法简单、廉价、快速，利用测定丙二醛含量跟踪疾病的进程和检测不同治疗方法的功效有实用价值和重要意义。     

Chitotriosidase: the yin and yang

The enzyme chitotriosidase (ChT), the human analogue of chitinases from non-vertebrate species, is one of the most abundant and indicative proteins secreted by activated macrophages. Its enzymatic activity is elevated in serum of patients suffering from Gaucher’s disease type 1 and in some other inherited lysosomal storage disorders, as well as in diseases in which macrophages are activated. The last decade has witnessed the appearance of a substantial number of studies attempting to unravel its cellular functions, which have yet not been fully defined. A great deal of progress has been made in the study of the physiological roles of ChT. This review is looks at the key areas of investigations addressed to further illuminate whether ChT activation might have different functional meanings in various diseases. Received 7 June 2006; received after revision 24 July 2006; accepted 21 September 2006     

Prion: the chameleon protein

From Creutzfeldt-Jakob disease (CJD) to variant CJD through Gerstmann-Str?ussler-Scheinker syndrome, kuru and fatal familial insomnia, the journey leading to current understanding of the basic aspects of human prion diseases has been full of unexpected, but often dramatic and always fascinating twists. Recent progress in modeling prion diseases and characterization of the various prion protein forms reveal that such a wide spectrum of the diseases is associated with the chameleon-like conformational features of prions.     

Abnormal protein aggregation and neurodegenerative diseases

Abnormal protein aggregation or amyloid is the major cause of many neurodegenerative disorders. The present review focuses on the correlation between sequence and structure features of proteins related to the diseases and abnormal protein aggregation. Recent progress has improved our knowledge on understanding the mechanism of amyloid formation. We suggest a nucleation model for ordered protein aggregation, which can also explain pathogenesis mechanisms of these neurodegenerative diseases in vivo.     

"Protein-only" or "virino" in prion diseases?

60-year prion and scrapie research has led to a dilemma in understanding the unknown aetiology of the infectious neurodegenerative disorders with intriguing features. Current progress and dilemma in prion research are briefly but critically reviewed. Instead of providing a comprehensive coverage of the research history, attentions in this view are drawn toward both the major breakthrough in the advancement of protein-only hypothesis, and the puzzle why this hypothesis has not been fully accepted. In order to resolve the prion enigma in neuroscience, it is suggested that both technical and concept barriers remain to be crossed. Since prion research is a multi-interdisciplinary subject, this view is intended to both facilitate a better understanding of prion phenomenon by more scientists in natural science, and invite scientists outside the fields of molecular genetics and protein science for collaboration.     

"Protein-only" or "virino" in prion diseases?

60-year prion and scrapie research has led to a dilemma in understanding the unknown aetiology of the infectious neurodegenerative disorders with intriguing features. Current progress and dilemma in prion research are briefly but critically reviewed. Instead of providing a comprehensive coverage of the research history, attentions in this view are drawn toward both the major breakthrough in the advancement of protein-only hypothesis, and the puzzle why this hypothesis has not been fully accepted. In order to resolve the prion enigma in neuroscience, it is suggested that both technical and concept barriers remain to be crossed. Since prion research is a multi-interdisciplinary subject, this view is intended to both facilitate a better understanding of prion phenomenon by more scientists in natural science, and invite scientists outside the fields of molecular genetics and protein science for collaboration.     

Melatonin regulation of antioxidant enzyme gene expression

Antioxidant enzymes (AOEs) are part of the primary cellular defense against free radicals induced by toxins and/or spontaneously formed in cells. Melatonin (MLT) has received much attention in recent years due to its direct free radical scavenging and antioxidant properties. In the present work we report that MLT, at physiological serum concentrations (≈ 1 nM), increases the mRNA of both superoxide dismutases (SODs) and glutathione peroxidase (GPx) in two neuronal cell lines. The MLT effect on both SODs and GPx mRNA was mediated by a de novo synthesized protein. MLT alters mRNA stability for Cu-Zn SOD and GPx. Experiments with a short time treatment (pulse action) of MLT suggest that the regulation of AOE gene expression is likely to be receptor mediated, because 1-h treatment with MLT results in the same response as a 24-h treatment. Received 18 June 2002; received after revision 5 August 2002; accepted 27 August 2002 RID="*" ID="*"Corresponding author.     

绿茶多酚在药物开发领域的研究进展

阐述了绿茶多酚的化学组成、生物代谢以及在药物开发领域的进展,主要集中在对癌症、神经退行性疾病、糖尿病的预防和治疗方面.茶多酚潜在的抗肿瘤活性可以通过干预肿瘤发生、发展、转移等各个阶段来进行,但茶多酚发展成为治疗药物还是面临很多挑战,比如,低生物药效率.基于纳米颗粒的药物传递系统相比单纯的茶多酚具有特别的优势,同时,为了处理新出现的安全问题和潜在的局部药物过量效应,有必要确定包裹纳米粒子以后的药物实际用量和药理学机制.     

骨髓间充质干细胞研究进展

干细胞移植是目前治疗器官损伤、神经退行性疾病研究的热点,国内外学者分别对神经干细胞、胚胎干细胞等进行了探索,渴望从中找出细胞移植领域的候选细胞,但是这些细胞大多面临着伦理、来源、免疫排斥等多方面的问题.然而,近年来发现的骨髓间充质干细胞在一定程度上弥补了这一不足.骨髓间充质干细胞凭借其多向分化潜能、强大的自我复制能力和可移植性,成为细胞移植、基因治疗中重要的候选细胞.骨髓间充质干细胞移植为器官损伤、神经退行性疾病的临床治疗带来了新的希望,本文对其生物学特性及临床应用方面做一综述.