Irisin alters D-galactose-induced apoptosis by increasing caveolin-1 expression in C2C12 myoblasts and skeletal muscle fibroblasts.

Muscle atrophy and skeletal muscle fibrosis are significant pathological manifestations of primary sarcopenia. The regulation of C2C12 myoblast and skeletal muscle fibroblast apoptosis is associated with these pathological changes. Previous studies have indicated that irisin, the cleaved form of fibronectin type III domain-containing protein 5 (FNDC5), can alleviate primary sarcopenia. However, the mechanisms of the effect of irisin in age-related apoptosis remain unknown. Our present research aimed to explore the effect of irisin and the underlying mechanism of D-galactose (D-gal)-induced apoptosis in skeletal muscle fibroblasts and C2C12 myoblasts. We found the opposite effects of D-gal on C2C12 myoblasts and fibroblasts. We also found that irisin suppressed C2C12 cell apoptosis and promoted fibroblast apoptosis. Mechanistically, irisin altered D-gal-induced apoptosis by increasing caveolin-1 expression. Taken together, these findings further demonstrated that irisin is a potential agent that can treat aged-relative muscle atrophy and fibrosis.

The key cellular senescence related molecule RRM2 regulates prostate cancer progression and resistance to docetaxel treatment.

BACKGROUND: Prostate cancer is a leading cause of cancer-related deaths among men worldwide. Docetaxel chemotherapy has proven effective in improving overall survival in patients with castration-resistant prostate cancer (CRPC), but drug resistance remains a considerable clinical challenge. METHODS: We explored the role of Ribonucleotide reductase subunit M2 (RRM2), a gene associated with senescence, in the sensitivity of prostate cancer to docetaxel. We evaluated the RRM2 expression, docetaxel resistance, and ANXA1 expression in prostate cancer cell lines and tumour xenografts models. In addition, We assessed the impact of RRM2 knockdown, ANXA1 over-expression, and PI3K/AKT pathway inhibition on the sensitivity of prostate cancer cells to docetaxel. Furthermore, we assessed the sensitivity of prostate cancer cells to the combination treatment of COH29 and docetaxel. RESULTS: Our results demonstrated a positive association between RRM2 expression and docetaxel resistance in prostate cancer cell lines and tumor xenograft models. Knockdown of RRM2 increased the sensitivity of prostate cancer cells to docetaxel, suggesting its role in mediating resistance. Furthermore, we observed that RRM2 stabilizes the expression of ANXA1, which in turn activates the PI3K/AKT pathway and contributes to docetaxel resistance. Importantly, we found that the combination treatment of COH29 and docetaxel resulted in a synergistic effect, further augmenting the sensitivity of prostate cancer cells to docetaxel. CONCLUSION: Our findings suggest that RRM2 regulates docetaxel resistance in prostate cancer by stabilizing ANXA1-mediated activation of the PI3K/AKT pathway. Targeting RRM2 or ANXA1 may offer a promising therapeutic strategy to overcome docetaxel resistance in prostate cancer.

Development and validation of a predicted nomogram for mortality of COVID-19: a multicenter retrospective cohort study of 4,711 cases in multiethnic.

Background: Coronavirus disease 2019 (COVID-19) is an infectious disease spreading rapidly worldwide. As it quickly spreads and can cause severe disease, early detection and treatment may reduce mortality. Therefore, the study aims to construct a risk model and a nomogram for predicting the mortality of COVID-19. Methods: The original data of this study were from the article "Neurologic Syndromes Predict Higher In-Hospital Mortality in COVID-19." The database contained 4,711 multiethnic patients. In this secondary analysis, a statistical difference test was conducted for clinical demographics, clinical characteristics, and laboratory indexes. The least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression analysis were applied to determine the independent predictors for the mortality of COVID-19. A nomogram was conducted and validated according to the independent predictors. The area under the curve (AUC), the calibration curve, and the decision curve analysis (DCA) were carried out to evaluate the nomogram. Results: The mortality of COVID-19 is 24.4%. LASSO and multivariate logistic regression analysis suggested that risk factors for age, PCT, glucose, D-dimer, CRP, troponin, BUN, LOS, MAP, AST, temperature, O2Sats, platelets, Asian, and stroke were independent predictors of CTO. Using these independent predictors, a nomogram was constructed with good discrimination (0.860 in the C index) and internal validation (0.8479 in the C index), respectively. The calibration curves and the DCA showed a high degree of reliability and precision for this clinical prediction model. Conclusion: An early warning model based on accessible variates from routine clinical tests to predict the mortality of COVID-19 were conducted. This nomogram can be conveniently used to facilitate identifying patients who might develop severe disease at an early stage of COVID-19. Further studies are warranted to validate the prognostic ability of the nomogram.

A LASSO-derived developing and validating risk model for chronic total occlusion in Asian population before coronary angiography.

Background: Despite several previous studies that have explored the predictors of high morbidity in coronary artery disease (CAD) and developed nomograms for CAD patients prior to coronary angiography (CAG), there is a lack of models available to predict chronic total occlusion (CTO). The aim of this study is to develop a risk model and a nomogram for predicting the probability of CTO prior to CAG. Methods: The study included 1,105 patients with CAG-diagnosed CTO in the derivation cohort and 368 patients in the validation cohort. Clinical demographics, echocardiography results, and laboratory indexes were analyzed using statistical difference tests. Independent risk factors affecting the CTO indication were selected using least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression analysis. A nomogram was built and validated based on these independent indicators. The performance of the nomogram was evaluated using area under the curve (AUC), calibration curve, and decision curve analysis (DCA). Results: LASSO and multivariate logistic regression analysis revealed that 6 variables, including sex (male), lymphocyte percentage (LYM%), ejection fraction (EF), myoglobin (Mb), non-high-density lipoprotein cholesterol (non-HDL), and N-terminal pro-B-type natriuretic peptide (NT-proBNP), were independent predictors of CTO. The nomogram constructed based on these variables showed good discrimination (C index of 0.744) and external validation (C index of 0.729). The calibration curves and DCA demonstrated high reliability and precision for this clinical prediction model. Conclusions: The nomogram based on sex (male), LYM%, EF, Mb, non-HDL, and NT-proBNP could be used to predict CTO in CAD patients, enhancing the ability to predict their prognosis in clinical practice. Further research is needed to validate the efficacy of the nomogram in other populations.

Irisin ameliorates D-galactose-induced skeletal muscle fibrosis via the PI3K/Akt pathway.

Primary sarcopenia is a multicausal skeletal muscle disease associated with muscle strength and mass loss. Skeletal muscle fibrosis is one of the significant pathological manifestations associated with the development of age-related sarcopenia. Irisin, which is cleaved by the extracellular domain of fibronectin type Ⅲ domain-containing protein 5 (FNDC5), has previously been reported to exert antifibrotic effects on the heart, liver, and pancreas, but whether it can rescue skeletal muscle fibrosis remains unknown. In this study, we examined the effects of irisin on D-galactose (D-gal)-induced skeletal muscle fibroblasts. We found that D-gal-induced senescence, fibrosis, and redox imbalance were inhibited by irisin treatment. Mechanistically, irisin or FNDC5 overexpression attenuated D-gal-induced senescence, redox imbalance, and fibrosis by regulating the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. Overall, irisin might be a promising therapeutic candidate for age-related skeletal muscle fibrosis.

Leveraging Machine Learning Techniques to Forecast Chronic Total Occlusion before Coronary Angiography.

BACKGROUND: Chronic total occlusion (CTO) remains the most challenging procedure in coronary artery disease (CAD) for interventional cardiology. Although some clinical risk factors for CAD have been identified, there is no personalized prognosis test available to confidently identify patients at high or low risk for CTO CAD. This investigation aimed to use a machine learning algorithm for clinical features from clinical routine to develop a precision medicine tool to predict CTO before CAG. METHODS: Data from 1473 CAD patients were obtained, including 1105 in the training cohort and 368 in the testing cohort. The baseline clinical characteristics were collected. Univariate and multivariate logistic regression analyses were conducted to identify independent risk factors that impact the diagnosis of CTO. A CTO predicting model was established and validated based on the independent predictors using a machine learning algorithm. The area under the curve (AUC) was used to evaluate the model. RESULTS: The CTO prediction model was developed with the training cohort using the machine learning algorithm. Eight variables were confirmed as 'important': gender (male), neutrophil percentage (NE%), hematocrit (HCT), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), ejection fraction (EF), troponin I (TnI), and N-terminal pro-B-type natriuretic peptide (NT-proBNP). The model achieved good concordance indices of 0.724 and 0.719 in the training and testing cohorts, respectively. CONCLUSIONS: An easy-to-use tool to predict CTO in patients with CAD was developed and validated. More research with larger cohorts are warranted to improve the prediction model, which can support clinician decisions on the early discerning CTO in CAD patients.

Knowledge mapping and current trends of immunotherapy for prostate cancer: A bibliometric study.

Background: Prostate cancer (PCa) is the second most common malignancy in men worldwide. Growing evidence substantiates the important role of immunotherapy in human tumors. Given that immunotherapy is often unsatisfactory on PCa, many studies have been conducted on PCa immunotherapy to improve treatment efficacy. However, no relevant bibliometric study of PCa immunotherapy has hitherto been reported. A bibliometric analysis was performed to evaluate the global scientific production of PCa immunotherapy research and characterize the development trends for future studies in this article. Methods: The publications related to PCa immunotherapy were extracted from the Web of Science Core Collection. The contribution and co-occurrence relationships of countries/regions, institutions, journals, references, authors, and keywords were assessed and visualized by VOSviewer and CiteSpace to identify research hotspots and potential future trends. Results: A total of 3,583 publications related to PCa immunotherapy from 1999 to 2021 were collected. The results of annual publications and citations exhibited a steady increase over the past 22 years. The National Cancer Institute in the USA published far more papers during the study than any institute. Accordingly, the USA had the most publications (n = 1,954, 54.54%). Gulley, James L. had the most number of published papers, and Small, Eric J. was the most co-cited authors in this field. Cancer Immunology Immunotherapy was the most productive journal, with 145 publications on PCa immunotherapy. Keyword cluster and keyword burst analyses showed that research in PCa immunotherapy shifted from "t cell infiltration" and "sipuleucel t" to "immune checkpoint inhibitor", "CTLA-4", and "PD-L1 expression". Conclusion: PCa immunotherapy has attracted much attention, reflected by the increasing number of annual publications and citations. Much emphasis has been placed on exploring the complex immunogenicity and tumor microenvironment for PCa and identifying the patient population who can benefit from immunotherapy. Combining immune checkpoint inhibitors with other therapeutic options and cancer vaccines represents the future development trends in PCa immunotherapy.

Analysis of parametric and non-parametric option pricing models.

In this paper, a closed-form analytical solution of option price under the Bi-Heston model is derived. Through empirical analysis, the advantages and disadvantages of the parametric pricing model are compared and analysed with those of the non-parametric model. The analysis shows that: (1) the parametric pricing model significantly outperforms the machine learning model in terms of in-sample pricing effects, while the Bi-Heston model slightly outperforms the Heston model. (2) In terms of out-of-sample pricing, the machine learning model is inferior to the parametric model for call options, while the Bi-Heston model is significantly better than the other two models for put options, and the other two models are similar. (3) In the robustness analysis of the three pricing models, the machine learning model shows strong instability, while the Bi-Heston model shows a more stable side.

The Whole-transcriptome Landscape of Diabetes-related Sarcopenia Reveals the Specific Function of Novel lncRNA Gm20743.

While the exact mechanism remains unclear, type 2 diabetes mellitus increases the risk of sarcopenia which is characterized by decreased muscle mass, strength, and function. Whole-transcriptome RNA sequencing and informatics were performed on the diabetes-induced sarcopenia model of db/db mice. To determine the specific function of lncRNA Gm20743, the detection of Mito-Sox, reactive oxygen species, Ethynyl-2'-deoxyuridine, and myosin heavy chain was performed in overexpressed and knockdown-Gm20743 C2C12 cells. RNA-seq data and informatics revealed the key lncRNA-mRNA interactions and indicated a potential regulatory role of lncRNAs. We characterized three core candidate lncRNAs Gm20743, Gm35438, 1700047G03Rik, and their potential function. Furthermore, the results suggested lncRNA Gm20743 may be involved in regulating mitochondrial function, oxidative stress, cell proliferation, and myotube differentiation in skeletal muscle cells. These findings significantly improve our understanding of lncRNAs that may mediate muscle mass, strength, and function in diabetes and represent potential therapeutic targets for diabetes-induced sarcopenia.

CHRNA1 induces sarcopenia through neuromuscular synaptic elimination.

Sarcopenia seriously affects the quality of life of the elderly, but its molecular mechanism is still unclear. Degeneration in muscle innervation is related to age-related movement disorders and muscle atrophy. The expression of CHRNA1 is increased in the skeletal muscle of the elderly, and in aging rodents. Therefore, we investigated whether CHRNA1 induces the occurrence and development of sarcopenia. Compared with the control group, local injection of AAV9-CHRNA1 into the hindlimb muscles decreased the percentage of muscle innervation. At the same time, the skeletal muscle mass decreased, as manifested by a decrease in the gastrocnemius mass index and the cross-sectional area of the muscle fibers. The function of skeletal muscle also decreased, which was manifested by decreases of compound muscle action potential and muscle contractility. Therefore, we concluded that upregulation of CHRNA1 can induce and aggravate sarcopenia.

Corrigendum: Identification of Signature Genes Associated With Invasiveness and the Construction of a Prognostic Model That Predicts the Overall Survival of Bladder Cancer.

[This corrects the article DOI: 10.3389/fgene.2021.694777.].

Lysyl oxidase-like 2 inhibitor rescues D-galactose-induced skeletal muscle fibrosis.

Aging-related sarcopenia is currently the most common sarcopenia. The main manifestations are skeletal muscle atrophy, replacement of muscle fibers with fat and fibrous tissue. Excessive fibrosis can impair muscle regeneration and function. Lysyl oxidase-like 2 (LOXL2) has previously been reported to be involved in the development of various tissue fibrosis. Here, we investigated the effects of LOXL2 inhibitor on D-galactose (D-gal)-induced skeletal muscle fibroblast cells and mice. Our molecular and physiological studies show that treatment with LOXL2 inhibitor can alleviate senescence, fibrosis, and increased production of reactive oxygen species in fibroblasts caused by D-gal. These effects are related to the inhibition of the TGF-ß1/p38 MAPK pathway. Furthermore, in vivo, mice treatment with LOXL2 inhibitor reduced D-gal-induced skeletal muscle fibrosis, partially enhanced skeletal muscle mass and strength and reduced redox balance disorder. Taken together, these data indicate the possibility of using LOXL2 inhibitors to prevent aging-related sarcopenia, especially with significant fibrosis.

MiR-501-5p alleviates cardiac dysfunction in septic patients through targeting NR4A3 to prevent its binding with Bcl-2.

Sepsis-induced myocardial dysfunction is a common complication in septic patients. To date, a limited number of biomarkers that could predict cardiomyocyte apoptosis have been explored. In this study, we successfully established a cecal ligation and puncture (CLP)-induced septic model, and it was found that miR-501-5p expression was down-regulated in peripheral blood samples of septic patients with cardiac dysfunction, lipopolysaccharide (LPS)-induced cardiomyocytes, and the myocardium and peripheral blood in the septic model. Moreover, it was revealed that miR-501-5p overexpression could increase left ventricular diastolic pressure (LVDP), fractional shortening (FS), ejection fraction (EF), and maximum rate of the rise of left ventricular pressure (+dp/dt) in vivo, while it decreased the levels of myocardial injury-related indicators. In addition, LPS induction accelerated apoptosis and elevated the inflammation in HL-1 and HCM cells, which could be reversed by miR-501-5p overexpression. Mechanistically, we considered nuclear receptor subfamily 4 group A member 3 (NR4A3) as the target of miR-501-5p, and it was found that miR-501-5p prevented the binding between NR4A3 and Bcl-2. It was found that miR-501-5p exerted an inhibitory effect on cardiomyocyte apoptosis and inflammation in a NR4A3-dependent manner. Overall, our results may provide evidence for consideration of miR-501-5p in the therapy of sepsis.

Persistence of Symptoms After Discharge of Patients Hospitalized Due to COVID-19.

Many patients who had coronavirus disease 2019 (COVID-19) had at least one symptom that persisted after recovery from the acute phase. Our purpose was to review the empirical evidence on symptom prevalence, complications, and management of patients with long COVID. We systematically reviewed the literature on the clinical manifestations of long COVID-19, defined by the persistence of symptoms beyond the acute phase of infection. Bibliographic searches in PubMed and Google Scholar were conducted to retrieve relevant studies on confirmed patients with long COVID that were published prior to August 30, 2021. The most common persistent symptoms were fatigue, cough, dyspnea, chest pains, chest tightness, joint pain, muscle pain, loss of taste or smell, hair loss, sleep difficulties, anxiety, and depression. Some of the less common persistent symptoms were skin rash, decreased appetite, sweating, inability to concentrate, and memory lapses. In addition to these general symptoms, some patients experienced dysfunctions of specific organs, mainly the lungs, heart, kidneys, and nervous system. A comprehensive understanding of the persistent clinical manifestations of COVID-19 can improve and facilitate patient management and referrals. Prompt rehabilitative care and targeted interventions of these patients may improve their recovery from physical, immune, and mental health symptoms.

MICU3 regulates mitochondrial Ca2+-dependent antioxidant response in skeletal muscle aging.

Age-related loss of skeletal muscle mass and function, termed sarcopenia, could impair the quality of life in the elderly. The mechanisms involved in skeletal muscle aging are intricate and largely unknown. However, more and more evidence demonstrated that mitochondrial dysfunction and apoptosis also play an important role in skeletal muscle aging. Recent studies have shown that mitochondrial calcium uniporter (MCU)-mediated mitochondrial calcium affects skeletal muscle mass and function by affecting mitochondrial function. During aging, we observed downregulated expression of mitochondrial calcium uptake family member3 (MICU3) in skeletal muscle, a regulator of MCU, which resulted in a significant reduction in mitochondrial calcium uptake. However, the role of MICU3 in skeletal muscle aging remains poorly understood. Therefore, we investigated the effect of MICU3 on the skeletal muscle of aged mice and senescent C2C12 cells induced by D-gal. Downregulation of MICU3 was associated with decreased myogenesis but increased oxidative stress and apoptosis. Reconstitution of MICU3 enhanced antioxidants, prevented the accumulation of mitochondrial ROS, decreased apoptosis, and increased myogenesis. These findings indicate that MICU3 might promote mitochondrial Ca2+ homeostasis and function, attenuate oxidative stress and apoptosis, and restore skeletal muscle mass and function. Therefore, MICU3 may be a potential therapeutic target in skeletal muscle aging.

Identification of Signature Genes Associated With Invasiveness and the Construction of a Prognostic Model That Predicts the Overall Survival of Bladder Cancer.

Background: Bladder cancer has become the tenth most diagnosed cancer worldwide. The prognosis has been shown to differ between non-muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC). We aimed to identify signature genes that are associated with the invasiveness and survival of bladder cancer and to identify potential treatments. Methods: We downloaded gene expression profiles of bladder cancer from the Gene Expression Omnibus database to identify differentially expressed genes and perform weighted gene co-expression network analysis. Functional enrichment was analyzed by GO and KEGG analyses. Hub genes were identified from the significant module. Another dataset was also acquired to verify the expression of hub genes. Univariate and multivariate Cox regression analyses were applied to the dataset downloaded from The Cancer Genome Atlas database. Risk scores were calculated and the effect was evaluated by Kaplan-Meier survival analysis. A nomogram was constructed and validated using training and testing samples, respectively. Analysis of the tumor immune microenvironment was conducted with the CIBERSORT algorithm. Results: In total, 1,245 differentially expressed genes (DEGs) were identified. A distinct module was identified that was significantly correlated to invasiveness. The genes within this module were found to be significantly associated with extracellular exosomes, GTPase activity, metabolic pathways, etc. Three hub genes (VSIG2, PPFIBP2, and DENND2D) were identified as biomarkers of invasiveness; two of these (PPFIBP2 and DENND2D) were closely associated with prognosis. The risk score was regarded as an independent prognostic factor. The nomogram was associated with acceptable accuracy for predicting 1- and 5-year overall survival. The infiltrating levels of resting NK cells, activated natural killer (NK) cells, CD8+ T cells, activated memory CD4+ T cells, and T follicular helper cells, were significantly higher in the group with lower risk scores. The group with higher risk scores showed predominant infiltration by regulatory T cells (Tregs). Conclusion: We successfully identified three signature genes related to invasiveness and constructed a nomogram of bladder cancer with acceptable performance. Differences suggested by risk scores between groups of patients showing diverse patterns of immune cell infiltration may be beneficial for selecting therapeutic approaches and predicting prognosis.

FGF19 protects skeletal muscle against obesity-induced muscle atrophy, metabolic derangement and abnormal irisin levels via the AMPK/SIRT-1/PGC-α pathway.

Obesity is associated with biological dysfunction in skeletal muscle. As a condition of obesity accompanied by muscle mass loss and physical dysfunction, sarcopenic obesity (SO) has become a novel public health problem. Human fibroblast growth factor 19 (FGF19) plays a therapeutic role in metabolic diseases. However, the protective effects of FGF19 on skeletal muscle in obesity and SO are still not completely understood. Our results showed that FGF19 administration improved muscle loss and grip strength in young and aged mice fed a high-fat diet (HFD). Increases in muscle atrophy markers (FOXO-3, Atrogin-1, MuRF-1) were abrogated by FGF19 in palmitic acid (PA)-treated C2C12 myotubes and in the skeletal muscle of HFD-fed mice. FGF19 not only reduced HFD-induced body weight gain, excessive lipid accumulation and hyperlipidaemia but also promoted energy expenditure (PGC-1α, UCP-1, PPAR-γ) in brown adipose tissue (BAT). FGF19 treatment restored PA- and HFD-induced hyperglycaemia, impaired glucose tolerance and insulin resistance (IRS-1, GLUT-4) and mitigated the PA- and HFD-induced decrease in FNDC-5/irisin expression. However, these beneficial effects of FGF19 on skeletal muscle were abolished by inhibiting AMPK, SIRT-1 and PGC-1α expression. Taken together, this study suggests that FGF19 protects skeletal muscle against obesity-induced muscle atrophy, metabolic derangement and abnormal irisin secretion partially through the AMPK/SIRT-1/PGC-α signalling pathway, which might be a potential therapeutic target for obesity and SO.

Near-surface softening and healing in eastern Honshu associated with the 2011 magnitude-9 Tohoku-Oki Earthquake.

The near-surface part of the crust, also called the skin of the earth, is the arena of human activity of which the stiffness is of great concern to engineers in infrastructure construction. The stiffness reduction of near-surface geomaterials also plays a vital role in geohazards triggering. However, the physical mechanism behind the material softening is still not fully understood. Here, we report a coseismic shear-wave velocity reduction in the near surface by up to a few tens of percent during the strongest shaking from the 11 March 2011 Tohoku-Oki Earthquake and a subsequent two-stage healing process including a rapid recovery within a few minutes and a slow recovery over many years. We also present a theoretical contact model between mineral grains in geomaterials containing multiple metastable contacts at small separations due to the oscillatory hydration interaction, which can explain the emergence of different stages in the healing process.