410 research outputs found
Generation and Bioenergetic Profiles of Cybrids with East Asian mtDNA Haplogroups
Human mitochondrial DNA (mtDNA) variants and haplogroups may contribute to susceptibility to various diseases and pathological conditions, but the underlying mechanisms are not well understood. To address this issue, we established a cytoplasmic hybrid (cybrid) system to investigate the role of mtDNA haplogroups in human disease; specifically, we examined the effects of East Asian mtDNA genetic backgrounds on oxidative phosphorylation (OxPhos). We found that mtDNA single nucleotide polymorphisms such as m.489T>C, m.10398A>G, m.10400C>T, m.C16223T, and m.T16362C affected mitochondrial function at the level of mtDNA, mtRNA, or the OxPhos complex. Macrohaplogroup M exhibited higher respiratory activity than haplogroup N owing to its higher mtDNA content, mtRNA transcript levels, and complex III abundance. Additionally, haplogroup M had higher reactive oxygen species levels and NAD+/NADH ratios than haplogroup N, suggesting difference in mitonuclear interactions. Notably, subhaplogroups G2, B4, and F1 appeared to contribute significantly to the differences between haplogroups M and N. Thus, our cybrid-based system can provide insight into the mechanistic basis for the role of mtDNA haplogroups in human diseases and the effect of mtDNA variants on mitochondrial OxPhos function. In addition, studies of mitonuclear interaction using this system can reveal predisposition to certain diseases conferred by variations in mtDNA
Time to Benefit of Sodium-Glucose Cotransporter-2 Inhibitors Among Patients With Heart Failure
IMPORTANCE Emerging evidence has consistently demonstrated that sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of heart failure (HF) hospitalization and cardiovascular (CV) death among patients with HF. However, it remains unclear how long a patient needs to live to potentially benefit from SGLT2 inhibitors in this population. OBJECTIVES To estimate the time to benefit from SGLT2 inhibitors among patients with HF. DESIGN, SETTING, AND PARTICIPANTS This comparative effectiveness study systematically searched PubMed for completed randomized clinical trials about SGLT2 inhibitors and patients with HF published until September 5, 2022; 5 trials with the year of publication ranging from 2019 to 2022 were eventually included. Statistical analysis was performed from April to October 2022. INTERVENTION Addition of SGLT2 inhibitors or placebo to guideline-recommended therapy. MAIN OUTCOMES AND MEASURES The primary outcome was the time to first event of CV death or worsening HF, which was broadly comparable across the included trials. RESULTS Five trials consisting of 21 947 patients with HF (7837 [35.7%] were female; mean or median age older than 65 years within each trial) were included. SGLT2 inhibitors significantly reduced the risk of worsening HF or CV death (hazard ratio [HR], 0.77 [95% CI, 0.73-0.82]). Time to first nominal statistical significance (P < .05) was 26 days (0.86 months), and statistical significance was sustained from day 118 (3.93 months) onwards. A mean of 0.19 (95% CI, 0.12-0.35) months were needed to prevent 1 worsening HF or CV death per 500 patients with SGLT2 inhibitors (absolute risk reduction [ARR], 0.002). Likewise, 0.66 (95% CI, 0.43-1.13) months was estimated to avoid 1 event per 200 patients with SGLT2 inhibitors (ARR, 0.005), 1.74 (95% CI, 1.07-2.61) months to avoid 1 event per 100 patients (ARR, 0.010), and 4.96 (95% CI, 3.18-7.26) months to avoid 1 event per 50 patients (ARR, 0.020). Further analyses indicated a shorter time to benefit for HF hospitalization and among patients with diabetes or HF with reduced ejection fraction. CONCLUSIONS AND RELEVANCE In this comparative effectiveness research study of estimating the time to benefit from SGLT2 inhibitors among patients with HF, a rapid clinical benefit in reducing CV death or worsening HF was found, suggesting that their use may be beneficial for most individuals with HF
Probiotic fermentation modifies the structures of pectic polysaccharides from carrot pulp
Previous studies have suggested that water-soluble polysaccharides from fermented carrot pulp (WSP-p) have stronger anti-diabetic effects than those from un-fermented carrot pulp (WSP-n). This study aimed to improve understanding of these functional differences by comparing their molecular structures. Weight-average molecular weights of WSP-p fractions were lower than those of the corresponding WSP-n fractions. While both WSPs had similar functional groups, more fragmented particles were observed on the surface of large particles of WSP-n than WSP-p. Monosaccharide composition and methylation analysis confirmed that both WSP-p and WSP-n were pectic polysaccharides, containing rhamnogalacturonan-I-type polysaccharides with 1,4-linked α-d-galacturonic acid residues and homogalacturonan regions with 1,4-GalpA linkages. 1H and 13C NMR showed that they had similar linkage patterns. These findings suggested that probiotic fermentation of WSP mainly cleaved the linkages between repeating units, and resulted in less polydisperse molecular size distributions
Interleukin-17A Contributes to Myocardial Ischemia/Reperfusion Injury by Regulating Cardiomyocyte Apoptosis and Neutrophil Infiltration
ObjectivesThis study tested whether interleukin (IL)-17A is involved in the pathogenesis of mouse myocardial ischemia/reperfusion (I/R) injury and investigated the mechanisms.BackgroundInflammatory processes play a major role in myocardial I/R injury. We recently identified IL-17A as an important cytokine in inflammatory cardiovascular diseases such as atherosclerosis and viral myocarditis. However, its role in myocardial I/R injury remains unknown.MethodsThe involvement of IL-17A was assessed in functional assays in mouse myocardial I/R injury by neutralization/repletion or genetic deficiency of IL-17A, and its mechanism on cardiomyocyte apoptosis and neutrophil infiltration were further studied in vivo and in vitro.ResultsInterleukin-17A was elevated after murine left coronary artery ligation and reperfusion. Intracellular cytokine staining revealed that γδT lymphocytes but not CD4+ helper T cells were a major source of IL-17A. Anti–IL-17A monoclonal antibody treatment or IL-17A knockout markedly ameliorated I/R injury, as demonstrated by reduced infarct size, reduced cardiac troponin T levels, and improved cardiac function. This improvement was associated with a reduction in cardiomyocyte apoptosis and neutrophil infiltration. In contrast, repletion of exogenous IL-17A induced the opposite effect. In vitro study showed that IL-17A mediated cardiomyocyte apoptosis through regulating the Bax/Bcl-2 ratio, induced CXC chemokine-mediated neutrophil migration and promoted neutrophil-endothelial cell adherence through induction of endothelial cell E-selectin and inter-cellular adhesion molecule-1 expression.ConclusionsIL-17A mainly produced by γδT cells plays a pathogenic role in myocardial I/R injury by inducing cardiomyocyte apoptosis and neutrophil infiltration
Analysis of postoperative ocular surface changes and intervention effect after pars plana vitrectomy in meibomian gland dysfunction dry eye patients
AIM: To observe ocular surface changes after phacovitrectomy in patients with mild to moderate meibomian gland dysfunction (MGD)-type dry eye and track clinical treatment response using a Keratograph 5M and a LipiView interferometer. METHODS: Forty cases were randomized into control group A and treatment group B; the latter received meibomian gland treatment 3d before phacovitrectomy and sodium hyaluronate before and after surgery. The average non-invasive tear film break-up time (NITBUTav), first non-invasive tear film break-up time (NITBUTf), non-invasive measured tear meniscus height (NTMH), meibomian gland loss (MGL), lipid layer thickness (LLT) and partial blink rate (PBR) were measured preoperatively and 1wk, 1 and 3mo postoperatively. RESULTS: The NITBUTav values of group A at 1wk (4.38±0.47), 1mo (6.76±0.70), and 3mo (7.25±0.68) were significantly lower than those of group B (7.45±0.78, 10.46±0.97, and 11.31±0.89; P=0.002, 0.004, and 0.001, respectively). The NTMH values of group B at 1wk (0.20±0.01) and 1mo (0.22±0.01) were markedly higher than those of group A (0.15±0.01 and 0.15±0.01; P=0.008 and P<0.001, respectively); however, there was no difference at 3mo. The LLT of group B at 3mo [91.5 (76.25-100.00)] significantly exceeded that of group A [65.00 (54.50-91.25), P=0.017]. No obvious intergroup difference was found in MGL or PBR (P>0.05). CONCLUSION: Mild to moderate MGD dry eye worsens in the short term after phacovitrectomy. Preoperative cleaning, hot compresses, and meibomian gland massage as well as preoperative and postoperative sodium hyaluronate promote the rapid recovery of tear film stability
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Liver-heart crosstalk controls IL-22 activity in cardiac protection after myocardial infarction.
Interleukin (IL)-22 regulates tissue inflammation and repair. Here we report participation of the liver in IL-22-mediated cardiac repair after acute myocardial infarction (MI). Methods: We induced experimental MI in mice by ligation of the left ascending artery and evaluated the effect of IL-22 on post-MI cardiac function and ventricular remodeling. Results: Daily subcutaneous injection of 100 µg/kg mouse recombinant IL-22 for seven days attenuated adverse ventricular remodeling and improved cardiac function in mice at 28 days after left anterior descending coronary artery ligation-induced MI. Pharmacological inhibition of signal transducer and activator of transcription (STAT3) muted these IL-22 activities. While cardiomyocyte-selective depletion of STAT3 did not affect IL-22 activities in protecting post-MI cardiac injury, hepatocyte-specific depletion of STAT3 fully muted these IL-22 cardioprotective activities. Hepatocyte-derived fibroblast growth factor (FGF21) was markedly increased in a STAT3-dependent manner following IL-22 administration and accounted for the cardioprotective benefit of IL-22. Microarray analyses revealed that FGF21 controlled the expression of cardiomyocyte genes that are involved in cholesterol homeostasis, DNA repair, peroxisome, oxidative phosphorylation, glycolysis, apoptosis, and steroid responses, all of which are responsible for cardiomyocyte survival. Conclusions: Supplementation of IL-22 in the first week after acute MI effectively prevented left ventricular dysfunction and heart failure. This activity of IL-22 involved crosstalk between the liver and heart after demonstrating a role of the hepatic STAT3-FGF21 axis in IL-22-induced post-MI cardiac protection
CSST Strong Lensing Preparation: a Framework for Detecting Strong Lenses in the Multi-color Imaging Survey by the China Survey Space Telescope (CSST)
Strong gravitational lensing is a powerful tool for investigating dark matter
and dark energy properties. With the advent of large-scale sky surveys, we can
discover strong lensing systems on an unprecedented scale, which requires
efficient tools to extract them from billions of astronomical objects. The
existing mainstream lens-finding tools are based on machine learning algorithms
and applied to cut-out-centered galaxies. However, according to the design and
survey strategy of optical surveys by CSST, preparing cutouts with multiple
bands requires considerable efforts. To overcome these challenges, we have
developed a framework based on a hierarchical visual Transformer with a sliding
window technique to search for strong lensing systems within entire images.
Moreover, given that multi-color images of strong lensing systems can provide
insights into their physical characteristics, our framework is specifically
crafted to identify strong lensing systems in images with any number of
channels. As evaluated using CSST mock data based on an Semi-Analytic Model
named CosmoDC2, our framework achieves precision and recall rates of 0.98 and
0.90, respectively. To evaluate the effectiveness of our method in real
observations, we have applied it to a subset of images from the DESI Legacy
Imaging Surveys and media images from Euclid Early Release Observations. 61 new
strong lensing system candidates are discovered by our method. However, we also
identified false positives arising primarily from the simplified galaxy
morphology assumptions within the simulation. This underscores the practical
limitations of our approach while simultaneously highlighting potential avenues
for future improvements.Comment: The paper is accepted by the AJ. The complete code could be
downloaded with DOI of: 10.12149/101393. Comments are welcom
Nuclear Export Signal Mutation of Epidermal Growth Factor Receptor Enhances Malignant Phenotypes of Cancer Cells
Nuclear epidermal growth factor receptor (EGFR) has been shown to be correlated with drug resistance and a poor prognosis in patients with cancer. Previously, we have identified a tripartite nuclear localization signal (NLS) within EGFR. To comprehensively determine the functions and underlying mechanism of nuclear EGFR and its clinical implications, we aimed to explore the nuclear export signal (NES) sequence of EGFR that is responsible for interacting with the exportins. We combined in silico prediction with site-directed mutagenesis approaches and identified a putative NES motif of EGFR, which is located in amino acid residues 736-749. Mutation at leucine 747 (L747) in the EGFR NES led to increased nuclear accumulation of the protein via a less efficient release of the exportin CRM1. Interestingly, L747 with serine (L747S) and with proline (L747P) mutations were found in both tyrosine kinase inhibitor (TKI)-treated and -naïve patients with lung cancer who had acquired or de novo TKI resistance and a poor outcome. Reconstituted expression of the single NES mutant EGF
Review and application of Artificial Neural Networks models in reliability analysis of steel structures
This paper presents a survey on the development and use of Artificial Neural Network (ANN) models in structural reliability analysis. The survey identifies the different types of ANNs, the methods of structural reliability assessment that are typically used, the techniques proposed for ANN training set improvement and also some applications of ANN approximations to structural design and optimization problems. ANN models are then used in the reliability analysis of a ship stiffened panel subjected to uniaxial compression loads induced by hull girder vertical bending moment, for which the collapse strength is obtained by means of nonlinear finite element analysis (FEA). The approaches adopted combine the use of adaptive ANN models to approximate directly the limit state function with Monte Carlo simulation (MCS), first order reliability methods (FORM) and MCS with importance sampling (IS), for reliability assessment. A comprehensive comparison of the predictions of the different reliability methods with ANN based LSFs and classical LSF evaluation linked to the FEA is provided
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