Roles of Exosome-Like Vesicles Released from Inflammatory C2C12 Myotubes: Regulation of Myocyte Differentiation and Myokine Expression

Background/Aims: The complicated differentiation processes of cells in skeletal muscle against inflammation that induce muscle atrophy are not fully elucidated. Given that skeletal muscle is a secretory organ, we evaluated the effects of inflammation on myogenic signals and myokine expression, and the roles of inflammatory exosomes released by myotubes in myogenic differentiation. Methods: Inflammation was induced by treatment of fully differentiated C2C12 myotubes with a cytokine mixture of TNF-α and INF-γ. Exosome-like vesicles (ELVs) were isolated from conditioned media of control or inflamed myotubes and incubated with myoblasts. The expression of molecular switches that contribute to myogenic differentiation, including several kinases, their downstream targets, and myokines, were evaluated using immunoblot analysis in inflamed myotubes and in myoblasts treated with ELVs. Results: Inflammation activated molecular mechanisms contributing to muscle atrophy, including AMPK, p-38 MAPK and JNK, while inhibiting Akt-mediated myogenic signals. In addition, inflammation induced myostatin expression with suppression of a myostatin-counteracting myokine, decorin. Well-characterized ELVs released from inflamed myotubes induced myoblast inflammation and inhibited myogenic mechanisms while stimulating atrophic signals. Conclusion: Inflammation of skeletal muscle induces muscle atrophy via multiple mechanisms, including the regulation of myokines and kinases. Inflammatory ELVs are likely to contribute to inflammation-induced muscle atrophy

Time-to-Event Genome-Wide Association Study for Incident Cardiovascular Disease in People with Type 2 Diabetes Mellitus

BACKGROUND: Type 2 diabetes mellitus (T2D) confers a two- to three-fold increased risk of cardiovascular disease (CVD). However, the mechanisms underlying increased CVD risk among people with T2D are only partially understood. We hypothesized that a genetic association study among people with T2D at risk for developing incident cardiovascular complications could provide insights into molecular genetic aspects underlying CVD. METHODS: From 16 studies of the Cohorts for Heart & Aging Research in Genomic Epidemiology (CHARGE) Consortium, we conducted a multi-ancestry time-to-event genome-wide association study (GWAS) for incident CVD among people with T2D using Cox proportional hazards models. Incident CVD was defined based on a composite of coronary artery disease (CAD), stroke, and cardiovascular death that occurred at least one year after the diagnosis of T2D. Cohort-level estimated effect sizes were combined using inverse variance weighted fixed effects meta-analysis. We also tested 204 known CAD variants for association with incident CVD among patients with T2D. RESULTS: A total of 49,230 participants with T2D were included in the analyses (31,118 European ancestries and 18,112 non-European ancestries) which consisted of 8,956 incident CVD cases over a range of mean follow-up duration between 3.2 and 33.7 years (event rate 18.2%). We identified three novel, distinct genetic loci for incident CVD among individuals with T2D that reached the threshold for genome-wide significance ( P<5.0×10 -8): rs147138607 (intergenic variant between CACNA1E and ZNF648) with a hazard ratio (HR) 1.23, 95% confidence interval (CI) 1.15 - 1.32, P=3.6×10 -9, rs11444867 (intergenic variant near HS3ST1) with HR 1.89, 95% CI 1.52 - 2.35, P=9.9×10 -9, and rs335407 (intergenic variant between TFB1M and NOX3) HR 1.25, 95% CI 1.16 - 1.35, P=1.5×10 -8. Among 204 known CAD loci, 32 were associated with incident CVD in people with T2D with P<0.05, and 5 were significant after Bonferroni correction ( P<0.00024, 0.05/204). A polygenic score of these 204 variants was significantly associated with incident CVD with HR 1.14 (95% CI 1.12 - 1.16) per 1 standard deviation increase ( P=1.0×10 -16). CONCLUSIONS: The data point to novel and known genomic regions associated with incident CVD among individuals with T2D

Findings of Angiography and Carotid Vessel Wall Imaging Associated with Post-Procedural Clinical Events after Carotid Artery Stenting

Purpose Vessel wall imaging (VWI) for carotid plaque is better for detecting unstable carotid plaque such as intraplaque hemorrhage (IPH), lipid-rich necrotic core (LRNC), and thin/ruptured fibrous cap. However, the role of VWI before carotid artery stenting (CAS) is unclear. Thus, this study aimed to determine the findings of symptomatic carotid stenosis before CAS on angiography and carotid VWI and to evaluate the imaging findings associated with post-procedural clinical events after CAS. Materials and Methods This retrospective study included 173 consecutive patients who underwent carotid VWI, CAS, and post-procedural diffusion-weighted imaging (DWI) after CAS. Findings of unstable plaque on carotid VWI and unstable findings on angiography were analyzed. We also analyzed the incidence of post-procedural clinical events, any stroke, myocardial infarction (MI), and death within 30 days of CAS. Results Of 173 patients, 101 (58.4%) had initial ischemic symptoms and positive findings on DWI. Symptomatic patients were significantly higher in patients with IPH than in patients without IPH (62.4% vs. 45.8%, P=0.031). Degree of stenosis, thrombus of the stenotic lesion, flow delay of internal carotid artery, and flow arrest by filter thrombus had significantly higher prevalence in the symptomatic group. Twenty patients (11.6%) had post-procedural clinical events such as any stroke, clinical symptoms, and/or MI. Hyperlipidemia and intraluminal thrombus on angiography were identified as significant factors influencing post-procedural events after CAS. Conclusion An intraluminal thrombus on angiography was identified as a significant factor influencing post-procedural clinical events after CAS

Experimental Models of Sarcopenia: Bridging Molecular Mechanism and Therapeutic Strategy

Sarcopenia has been defined as a progressive decline of skeletal muscle mass, strength, and functions in elderly people. It is accompanied by physical frailty, functional disability, falls, hospitalization, and mortality, and is becoming a major geriatric disorder owing to the increasing life expectancy and growing older population worldwide. Experimental models are critical to understand the pathophysiology of sarcopenia and develop therapeutic strategies. Although its etiologies remain to be further elucidated, several mechanisms of sarcopenia have been identified, including cellular senescence, proteostasis imbalance, oxidative stress, and &ldquo;inflammaging.&rdquo; In this article, we address three main aspects. First, we describe the fundamental aging mechanisms. Next, we discuss both in vitro and in vivo experimental models based on molecular mechanisms that have the potential to elucidate the biochemical processes integral to sarcopenia. The use of appropriate models to reflect sarcopenia and/or its underlying pathways will enable researchers to understand sarcopenia and develop novel therapeutic strategies for sarcopenia. Lastly, we discuss the possible molecular targets and the current status of drug candidates for sarcopenia treatment. In conclusion, the development of experimental models for sarcopenia is essential to discover molecular targets that are valuable as biochemical biomarkers and/or therapeutic targets for sarcopenia

Development of Alzheimer&rsquo;s Disease Biomarkers: From CSF- to Blood-Based Biomarkers

In the 115 years since the discovery of Alzheimer&rsquo;s disease (AD), our knowledge, diagnosis, and therapeutics have significantly improved. Biomarkers are the primary tools for clinical research, diagnostics, and therapeutic monitoring in clinical trials. They provide much insightful information, and while they are not clinically used routinely, they help us to understand the mechanisms of this disease. This review charts the journey of AD biomarker discovery and development from cerebrospinal fluid (CSF) amyloid-beta 1-42 (A&beta;42), total tau (T-tau), and phosphorylated tau (p-tau) biomarkers and imaging technologies to the next generation of biomarkers. We also discuss advanced high-sensitivity assay platforms for CSF A&beta;42, T-tau, p-tau, and blood analysis. The recently proposed A&beta; deposition/tau biomarker/neurodegeneration or neuronal injury (ATN) scheme might facilitate the definition of the biological status underpinning AD and offer a common language among researchers across biochemical biomarkers and imaging. Moreover, we highlight blood-based biomarkers for AD that offer a scalable alternative to CSF biomarkers through cost-saving and reduced invasiveness, and may provide an understanding of disease initiation and development. We discuss different groups of blood-based biomarker candidates, their advantages and limitations, and paths forward, from identification and analysis to clinical validation. The development of valid blood-based biomarkers may facilitate the implementation of future AD therapeutics and diagnostics

<i>Drosophila Eyes Absent</i> Is Required for Normal Cone and Pigment Cell Development

<div><p>In <i>Drosophila</i>, development of the compound eye is orchestrated by a network of highly conserved transcriptional regulators known as the retinal determination (RD) network. The retinal determination gene <i>eyes absent</i> (<i>eya</i>) is expressed in most cells within the developing eye field, from undifferentiated retinal progenitors to photoreceptor cells whose differentiation begins at the morphogenetic furrow (MF). Loss of <i>eya</i> expression leads to an early block in retinal development, making it impossible to study the role of <i>eya</i> expression during later steps of retinal differentiation. We have identified two new regulatory regions that control <i>eya</i> expression during retinal development. These two enhancers are necessary to maintain <i>eya</i> expression anterior to the MF (<i>eya-IAM</i>) and in photoreceptors (<i>eya-PSE</i>), respectively. We find that deleting these enhancers affects developmental events anterior to the MF as well as retinal differentiation posterior to the MF. In line with previous results, we find that reducing <i>eya</i> expression anterior to the MF affects several early steps during early retinal differentiation, including cell cycle arrest and expression of the proneural gene <i>ato</i>. Consistent with previous observations that suggest a role for <i>eya</i> in cell proliferation during early development we find that deletion of <i>eya-IAM</i> leads to a marked reduction in the size of the adult retinal field. On the other hand, deletion of <i>eya-PSE</i> leads to defects in cone and pigment cell development. In addition we find that <i>eya</i> expression is necessary to activate expression of the cone cell marker Cut and to regulate levels of the Hedgehog pathway effector Ci. In summary, our study uncovers novel aspects of <i>eya</i>-mediated regulation of eye development. The genetic tools generated in this study will allow for a detailed study of how the RD network regulates key steps in eye formation.</p></div

RNAi-mediated knockdown of <i>eya</i> or <i>so</i> strongly reduce Cut expression.

<p>Cut (green) and Elav (magenta) expression in third instar eye discs (A-C, E-G, I-K, and M-O) and adult eyes (D, H, L and P) are shown. <i>GMR-Gal4/+; UAS-eyaRNAi/+</i> (A-D), <i>GMR-Gal4; UAS-soRNAi</i> (E-H), <i>UAS-eyaRNAi/+</i> (I-L), <i>UAS-soRNAi</i>/+ (M-P).</p

Distinct hydrophobic-hydrophilic dual interactions occurring in the clathrate hydrates of 3,3-dimethyl-1-butanol with help gases

To unlock the potential of clathrates hydrate for versatile applications in energy and environmental application such as energy storage, gas separation, and novel functional materials, profound understanding of their hidden nature must be secured. In this study, we focused on the complex host-guest and heterogeneous guest-guest interactions occurring on the sH hydrates of 3,3-dimethyl-1-butanol with help gases of CH4 or CO2. The density functional theory calculations and spectroscopic experimental analyses showed that the dynamics of the large 3,3-dimethyl-1-butanol guest molecule as well as the host water frameworks of sH hydrate were significantly influenced by the type of gaseous co-guest molecules via complex host-guest and/or guest-guest interactions. The flexible hydrogen-bonded water framework underwent contraction or elongation in the O:H-O hydrogen and O-H polar-covalent bonds induced by distinct occupation patterns of the co-guest help gases, and it was observed that, depending on the type, the co-guest help gases triggered the transformation of torsional configuration of the hydrophobic moieties of the large 3,3-dimethyl-1-butanol guest molecule while the hydrophilic part was incorporated into the host water framework

<i>eya</i> is required for normal Cyclin B and Ato expression.

<p>Cyclin B (A), Ato (B) and Elav (C) expression in <i>eya^cliIID</i> clones rescued by <i>eya^GRΔIAM</i>. <i>eya^cliIID</i> clones are marked by the absence of β-galactosidase expression (green in B, C, E, F, H, and I). Yellow dashed lines and arrowheads indicate the position of the MF, cyan arrowheads in A-C indicate the position of the second mitotic wave. In panel D, cyan and yellow brackets mark Ato expression in <i>eya^cliIID</i> clones and <i>eya^cliIID</i> heterozygous tissue, respectively.</p

<i>eya</i> is required for development of cone and pigment cells.

<p>Pupal retina (A, B), Adult plastic sections (C-F) of <i>eya^GR</i> and <i>eya^ΔPSE</i>. Clones of <i>eya^ΔPSE</i> in third instar eye disc (G-L). Pupae stained for Dlg (white, A and B) show cone cells and pigment cells. The adult eye sections show the rhabdomere structure of adult eyes. <i>eya^GR</i> (A and C) <i>eya^GRΔPSE</i> (B, E and F) <i>eya^GRΔIAM</i> (D). Arrow heads indicate pigment cells and asterisks show cone cells, respectively. Clones of <i>eya^cliIID</i> rescued by <i>eya^GRΔPSE</i> stained for Cut (white in G, magenta in I) and Ci expression (white in J, magenta in L). <i>eya^cliIID</i> clones are marked by the absence of β-galactosidase expression (white in H and K, green in I and L).</p