Study the pathological features of diseases using induced pluripotent stem cells derived form patient's somatic cells
The limited experimental access to disease-affected human tissues has severely impeded the elucidating of molecular mechanisms underlying disease development. Generation of induced pluripotent stem cells (iPSCs) by over-expression of defined transcription factors in somatic cells, in particular in those from patient somatic cells, presents an attractive and promising approach to model the early stages of diseases in vitro and to screen novel biomarkers as well as therapeutic medicines. Recently, many research groups have independently reported that patient-specific iPSC-derived cells recapitulated multiple features of pathological events of a particular disease, offering experimental evidence of utilizing patient-specific iPSCs to model diseases and reevaluate the current therapies. We have derived iPSC lines using somatic cells of patients suffering from Klinefelter's Syndrome (KS) and Alzheimer's Disease (AD) and explored the possibility to use these iPSC lines to recapitulate the pathological features of the diseases. Our results show that patient's specific iPSC lines provide good opportunity to study the development and treatment of diseases.
Study the pathological features of diseases using induced pluripotent stem cells derived form patient's somatic cells
The limited experimental access to disease-affected human tissues has severely impeded the elucidating of molecular mechanisms underlying disease development. Generation of induced pluripotent stem cells (iPSCs) by over-expression of defined transcription factors in somatic cells, in particular in those from patient somatic cells, presents an attractive and promising approach to model the early stages of diseases in vitro and to screen novel biomarkers as well as therapeutic medicines. Recently, many research groups have independently reported that patient-specific iPSC-derived cells recapitulated multiple features of pathological events of a particular disease, offering experimental evidence of utilizing patient-specific iPSCs to model diseases and reevaluate the current therapies. We have derived iPSC lines using somatic cells of patients suffering from Klinefelter's Syndrome (KS) and Alzheimer's Disease (AD) and explored the possibility to use these iPSC lines to recapitulate the pathological features of the diseases. Our results show that patient's specific iPSC lines provide good opportunity to study the development and treatment of diseases.
李于：SIRT1 Regulation of Energy Metabolism: Attenuation of Hepatic Steatosis and Obesity
Fibroblast growth factor 21 (FGF21) is the hepatocyte-derived hormone that regulates fatty acid metabolism and has potential to treat obesity and diabetes. We recently indicate that hepatic overexpression of SIRT1 in diabetic mice attenuates hepatic steatosis and insulin resistance. However, the in vivo long-term consequence of hepatic SIRT1 ablation in liver physiology remains unknown.
We showed that hepatocyte-specific SIRT1 knockout (SIRT1 LKO) mice with the albumin Cre-loxP system exhibited a striking phenotype with greater propensity for obesity on a chow diet, characterized by increased whole body mass and fat mass, reduced energy expenditure, and unaltered food intake and physical activity. The obese phenotypes of SIRT1 LKO mice were associated with reduced hepatic and circulating levels of fasting FGF21.
Hepatic impairment of FGF21 repressed expression of key enzymes involving fatty acid oxidation such as CPT1α and MCAD, and inhibited expression of ketogenic enzymes including ACAT1, HMGCS2, HMGCL, and BDH1, thereby reducing plasma β–hydroxybutyrate levels in SIRT1 LKO mice. Moreover, transcriptional activity of a FGF21 promoter-driven luciferase reporter was stimulated by SIRT1 activators, resveratrol and SRT1720, in SIRT1+/+ MEFs, but not in SIRT1-/- MEFs.
The ability of resveratrol and SRT1720 to stimulate FGF21 protein was abolished by SIRT1 H335A inactive mutant or by nicotinamide and splitomicin in HepG2 cells. Induction of FGF21 by SIRT1 activators enhanced expression of key enzymes for fatty acid oxidation and ketogenesis.
These in vivo and in vitro findings characterize 1) hepatic SIRT1 as a master regulator of FGF21; 2) SIRT1-dependent activation of FGF21 in liver as a component for adaptive fasting response; and 3) defective hepatic SIRT1 and FGF21 signaling as a key pathological determinant of energy metabolic abnormality and obesity susceptibility.
Erich Gnaiger：Life Style and Mitochondrial Competence – Modern Drugs for T2 Diabetes in Aging and Degenerative Diseases.
D. Swarovski Research Laboratory (Mitochondrial Physiology), Dept. General, Visceral and Transplant Surgery, Innsbruck Medical University; and OROBOROS INSTRUMENTS, Innsbruck, Austria. - Email: erich.gnaiger@oroboros.at
The contribution of mitochondrial dysfunction to the etiology of T2 diabetes and a range of preventable metabolic diseases is the subject of intensive current research with world-wide health implications.
Recently these investigations gained depth and scope by technological advances for diagnosis of mitochondrial function by comprehensive OXPHOS analysis using high-resolution respirometry [1,2]. Fundamental questions of a causal relationship, however, between compromised mitochondrial function and development of T2 diabetes remain to be resolved [3,4] to optimize prevention and treatment of insulin resistance.
For preventable diseases such as T2 diabetes, the evolutionary background of mitochondrial competence provides a solid basis for improved and broad application of a well established modern drug, mtLSD.
Post-industrial societies are characterized by a high-energy input lifestyle with diminished physical activity and high incidence of non-transmittable diseases, in comparison to human populations where physical work is essentially important for sustaining life and in which degenerative diseases (T2 diabetes, various cancers, Alzheimer's) are essentially absent [5]. The capacity of oxidative phosphorylation (OXPHOS) is increased or maintained high by a life style involving endurance exercise and strength training [6].
Life style changes from the age of 20-30 years to the elderly, but is subject to change and intervention. Depending on group selection in cross-sectional studies, OXPHOS capacity declines from the age of 20-30 years [7,8], or is independent of age up to 80 years [9,10].
Independent of age, there is a strong decline of OXPHOS capacity in human vastus lateralis from BMI of 20 to 30 [1]. At a BMI >30, a threshold OXPHOS capacity is reached in human v. lateralis that may be characteristic of a low-grade inflammatory state (‘mitochondrial fever’).
Onset of degenerative diseases (T2 diabetes, neuromuscular degeneration, various cancers) and mitochondrial dysfunction interact in an amplification loop progressing slowly with age, such that cause and effect of mitochondrial dysfunction cannot be distinguished. Diminished antioxidant capacity at low mitochondrial density is an important mechanistic candidate in the state of mitochondrial fever.
For implementing a life style supporting mitochondrial competence and preventing degenerative diseases in modern societies, we need (1) extended research programmes focused on the causative link between mitochondrial competence and effective prevention of degenerative diseases, (2) educational programmes on mitochondrial physiology targeted at general practitioners, teachers and the society at large, (3) cooperation of health care and insurance organizations to support preventive life style activities, and (4) do not miss any opportunity in taking the lead in living the mtLife Style Drug (mtLSD).
秦正红：DRAM1 regulates autophagy flux and Bid-mediated cell death via lysosomes
秦正红，博士，教授，神经药理专业博士生导师。1994年在美国宾州医学院研究生院获博士学位，先后在美国国家卫生研究院(NIH)及麻省总医院和哈佛大学医学院从事研究工作。2003年从哈佛大学引进，现为苏州大学医学部基础医学与生物科学学院科研中心实验室主任，中国药理学会生化药理学专业委员会委员，中国药理学会神经药理学专业委员会委员，美国神经科学学会会员。
Damage-regulated autophagy modulator1 (DRAM1), a novel TP53 target gene, is an evolutionarily conserved lysosomal protein and plays an essential role in TP53-dependent autophagy activation and apoptosis (Crighton et al, 2006). However, the mechanisms by which DRAM1 promotes autophagy and apoptosis are not clear.
3-Nitropropionic acid (3-NP) is an inhibitor of mitochondrial respiratory complex II. Intrastriatal administration of 3-NP produces neuropathology resemble to Huntington disease. 3-NP-induced neuronal death was involved in autophagy and apoptosis. In vitro studies with 3-NP in TP53 wt and null cells, 3-NP or CCCP increased the protein levels of DRAM1 in a TP53-dependent or independent manner. DRAM1 induction contributed to 3-NP-induced autophagy activation. Knock-down of DRAM1 with siRNA inhibited the activity of V-ATPase, acidification of lysosomes and activation of lysosomal proteases. Knock-down of DRAM1 reduced the clearance of autophagososmes.
3-NP also induced a transcription independent upregulation of BAX protein levels. Knock-down of DRAM1 suppressed the increase in BAX levels. Co-immunoprecipitation and pull-down studies revealed an interaction of DRAM1 and BAX protein. Stably expression of exogenous DRAM1 increased the half-life of BAX. Upregulation of DRAM1 recruited BAX to lysosomes and induced cathepsin B-dependent cleavage of Bid and cytochrome c release. Knockdown of DRAM1, BAX or inhibition of lysosomal enzymes reduced 3-NP-induced cytochrome c release and cell death.
These data suggest that DRAM1 plays important roles in regulating autophagy flux and apoptosis. DRAM1 promotes autophagy flux through a mechanism involves activation of V-ATPase and enhances the acidification of lysosomes. DRAM1 promotes apoptosis via a mechanism involving recruitment of BAX to lysosomes to trigger cathepsin B-mediated Bid cleavage.
Immunoblot Analysis Sean Gallagher(UVP,LLC)and Deb Chakravart(Proteomic Center)
Immunoblot Analysis Sean Gallagher(UVP,LLC)and Deb Chakravart(Proteomic Center)
CellSearch检测CTC--陈巍学基因（30）
欢迎来到【陈巍学基因】,我们这个节目，主要是为大家介绍基因组学，和临床分子诊断的最新技术进展。
今天，会和大家谈一下Jassen公司（强生公司）出品的CellSearch系统。它的主要应用是：检测循环肿瘤细胞，并对癌症给出预后信息。以下是课程内容概括：
1.什么是循环肿瘤细胞(CTC)及其“液体活检”的难点。
2. CellSearch系统的检测原理：（1）用微磁珠对CTC细胞进行富集；（2）用针对DNA的荧光染色剂“DAPI”进行染色，以排除红细胞；（3）区分白细胞和CTC细胞。
3.CellSearch系统实际操作的演示。
4.CTC检测，在癌症诊疗方面所起到的作用。
综上所述：CellSearch系统，是第一个标准化的、半自动化的，循环肿瘤细胞检测系统。它通过快速、精确地确定血液样本中的CTC细胞数量。可以帮助医生在整个治疗过程当中，提供准确的预后评估手段。
布鲁斯·艾伯茨：Learning from Failure
Alberts declares "Success doesn't really teach you much, failure teaches you a lot." Speaking from his personal experience, Alberts asserts that all scientists make mistakes and suffer setbacks but learning from those failures is what allows one ultimately to succeed.
Introducing the EnSight™ Multimode Plate Reader from PerkinElmer
PerkinElmer's EnSight Multimode Plate Reader is the first benchtop system to offer well-imaging alongside label-free and labeled detection technologies - for a whole new perspective on your research. For more information, please visit the EnSight website - http://bit.ly/T4IDPh