Pathogenic and therapeutic role of exosomes in neurodegenerative disorders

Neurodegenerative disorders affect millions of people worldwide,and the prevalence of these disorders is only projected to rise as the number of people over 65 will drastically increase in the coming years.While therapies exist to aid in symptomatic relief,effective treatments that can stop or reve rse the progress of each neurodegenerative disease are lacking.Recently,research on the role of extracellular vesicles as disease markers and therapeutics has been intensively studied.Exosomes,30-150 nm in diameter,are one type of extracellular vesicles facilitating cell-to-cell communication.Exosomes are thought to play a role in disease propagation in a variety of neurodegenerative diseases,such as Alzheimer's disease,Parkinson s disease,and amyotrophic lateral sclerosis.Accordingly,the exosomes derived from the patients are an invaluable source of disease biomarkers.On the other hand,exosomes,especially those derived from stem cells,could serve as a therapeutic for these disorders,as seen by a rapid increase in clinical trials investigating the therapeutic efficacy of exosomes in different neurological diseases.This review summarizes the pathological burden and therapeutic approach of exosomes in neurodegenerative disorders.We also highlight how heat shock increases the yield of exosomes while still maintaining their therapeutic efficacy.Finally,this review concludes with outstanding questions that remain to be addressed in exosomal research.

Physiological levels of ATP negatively regulate proteasome function

Intracellular protein degradation by the ubiquitin-proteasome system is ATP dependent, and the optimal ATP concentration to activate proteasome function in vitro is -100 μM. IntraceUular ATP levels are generally in the low millimolar range, but ATP at a level within this range was shown to inhibit proteasome peptidase activities in vitro. Here, we report new evidence that supports a hypothesis that intracellular ATP at the physiological levels bidirectionally regulates 26S proteasome proteolytic function in the cell. First, we confirmed that ATP exerted bidirectional regulation on the 26S proteasome in vitro, with the optimal ATP concentration （between 50 and 100μM） stimulating proteasome chymotrypsin-like activities. Second, we found that manipulating intracellular ATP levels also led to bidirectional changes in the levels of proteasome-specific protein substrates in cultured cells. Finally, measures to increase intracellular ATP enhanced, while decreasing intraceHular ATP attenuated the ability of proteasome inhibition to induce cell death. These data strongly suggest that endogenous ATP within the physiological concentration range can exert a negative impact on proteasome activities, allowing the cell to rapidly upregulate proteasome activity on ATP reduction under stress conditions.

Compilation and Analysis of Atherosclerosis Gene Expression Data

The objective of this project was to search for consensus in differential gene expression data and in regulation of differentially expressed genes among DNA microarray studies of atherosclerotic vessels and plaque. Seventeen DNA microarray studies of atherosclerosis were analyzed. Only 19 genes were found to be differentially expressed in 3 or more of the studies. The nineteen genes belong to classic gene ontologies known to be involved in atherosclerosis: immunity and defense, metabolism, proteases, receptors, and signal transduction. Four bioinformatics programs (TRED, rVISTA, JASPAR, and Ariadne Pathways) were used to further analyze the promoter regions and common upstream regulators of the 19 genes. Twelve of the genes shared nine common upstream regulators, many of them known to affect atherosclerosis, and one possible new pathway was identified that may be involved in this disease.

c-fos,bax和p53的反义寡聚核苷酸(ASOs)对溶血磷脂酸所致的培养小鼠大脑皮层神经元凋亡的影响(英文)

溶血磷脂酸(lysophosphatidic acid,LPA)在高浓度时( >50μmol/L)显示出对培养大脑皮层神经元致凋亡特性。本研究旨在初步分析溶血磷脂酸致凋亡过程中对相关基因表达的依赖性,在研究中结合琼脂糖电泳,HO33342染色和TUNEL技术观察c-fos,bax和p53三种反义寡聚核苷酸对溶血磷脂酸致培养大脑皮层神经元致凋亡的影响。结果显示结合c-fos, bax和p53三种反义寡聚核苷酸均表现出对溶血磷脂酸致凋亡的神经保护作用。溶血磷脂酸的致凋亡过程为c-fos,bax和p53基因依赖性,不同于b淀粉样蛋白片段31 -35的致凋亡特性。

δ-Opioid receptor as a potential therapeutic target for ischemic stroke

Ischemic stroke is a global epidemic condition due to an inadequate supply of blood and oxygen to a specific area of brain either by arterial blockage or by narrowing of blood vessels.Despite having advancement in the use of thrombolytic and clot removal medicine,significant numbers of stroke patients are still left out without option for treatment.In this review,we summarize recent research work on the activation ofδ-opioid receptor as a strategy for treating ischemic stroke-caused neuronal injury.Moreover,as activation ofδ-opioid receptor by a non-peptidicδ-opioid receptor agonist also modulates the expression,maturation and processing of amyloid precursor protein andβ-secretase activity,the potential role of these effects on ischemic stroke caused dementia or Alzheimer’s disease are also discussed.

TNF<i>α</i>and IL1<i>β</i>Stimulate Differential Gene Expression in Endometrial Stromal Cells

The purpose of this study was to test the hypothesis that specific macrophage-secreted cytokines cause gene expression changes in endometrial stromal cells that reproduce the effects of macro-phages in the development of endometriosis. Telomerase-immortalized human endometrial stromal cells (T-HESC) were treated with tumor necrosis factor α (TNFα, 5 ng/ml) and interleukin 1β (IL1β, 1 ng/ml). Differential expression of 249 genes was identified by DNA microarray. Ontologies such as peptidases, cell adhesion, cell death/cell cycle, growth factors, cytoskeletal organization, defense/immune system, signal transduction, and transcriptional regulation which are related to the development of endometriosis were represented by these genes. The up-regulation of interleukin 8 (IL8), interleukin 6 (IL6), IL1β and matrix metallopro-teinase 3 (MMP3) in response to TNFα ± ILIβ in T-HESC cells was confirmed by real time RT-PCR. TNFα ± ILIβ did not affect the migration or invasion of T-HESC cells. This study reinforces our previous investigations on communication between cells of the immune system and endometrial stromal cells and their potential role in the development of endometriosis.

Cyst aspiration with gonadotropin suppression in ovarian remnant syndrome with ureteral obstruction: A case report

Background: Ovarian remnant syndrome (ORS) is characterized by functional ovarian tissue following bilateral salpingo-oophorectomy. ORS presents with pelvic pain or mass, but may also present with urinary tract symptoms resulting from enlarging residual tissue. Case: A 37 year old woman presented with pelvic pain radiating to her flank due to ureteral obstruction from an enlarging ovarian cyst in ORS. Transvaginal ultrasound guided, ovarian cyst aspiration accompanied by leuprolide acetate gonadotropin suppression resulted in acute and chronic relief of ureteral obstruction. Conclusion: This case demonstrated successful treatment of ureteral obstruction caused by an ovarian cyst in a patient with ORS via cyst aspiration and leuprolide acetate gonadotropin suppression. This treatment is a viable alternative for management of ORS, but sacrifices pathologic diagnosis when compared to traditional surgical resection.