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Abstract This study aimed to explore the effects of peroxisome proliferator-activated receptor α (PPAR-α), a known inhibitor of ferroptosis, in Myocardial ischemia/reperfusion injury (MIRI) and its related mechanisms. In vivo and in vitro MIRI models were established. Our results showed that activation of PPAR-α decreased the size of the myocardial infarct, maintained cardiac function, and decreased the serum contents of creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and Fe2+ in ischemia/reperfusion (I/R)-treated mice. Additionally, the results of H&E staining, DHE staining, TUNEL staining, and transmission electron microscopy demonstrated that activation of PPAR-α inhibited MIRI-induced heart tissue and mitochondrial damage. It was also found that activation of PPAR-α attenuated MIRI-induced ferroptosis as shown by a reduction in malondialdehyde, total iron, and reactive oxygen species (ROS). In vitro experiments showed that intracellular contents of malondialdehyde, total iron, LDH, reactive oxygen species (ROS), lipid ROS, oxidized glutathione disulphide (GSSG), and Fe2+ were reduced by the activation of PPAR-α in H9c2 cells treated with anoxia/reoxygenation (A/R), while the cell viability and GSH were increased after PPAR-α activation. Additionally, changes in protein levels of the ferroptosis marker further confirmed the beneficial effects of PPAR-α activation on MIRI-induced ferroptosis. Moreover, the results of immunofluorescence and dual-luciferase reporter assay revealed that PPAR-α achieved its activity via binding to the 14-3-3η promoter, promoting its expression level. Moreover, the cardioprotective effects of PPAR-α could be canceled by pAd/14-3-3η-shRNA or Compound C11 (14-3-3η inhibitor). In conclusion, our results indicated that ferroptosis plays a key role in aggravating MIRI, and PPAR-α/14-3-3η pathway-mediated ferroptosis and mitochondrial injury might be an effective therapeutic target against MIRI.

There is an urgent need to explore and validate novel biomarkers relevant to patients with myocardial infarction (MI), which is the leading cause of death in the world. Dysregulated microRNAs (miRNAs) and messenger RNAs (mRNAs) based on two Gene Expression Omnibus microarrays were analyzed using bioinformatics technology and experiments. KEGG and GO enrichment analyses were performed to explore potential mechanisms of myocardial infarction progression. Immune infiltration analysis was used to assess the relationship between the immune microenvironment and myocardial infarction. The DOX-induced myocardial injury model was used to simulate myocardial infarction. qRT-PCR was performed to validate the expression of hub genes. 5 downregulated miRNAs and 14 upregulated mRNAs were identified in total. Functional analysis revealed that some immune-related pathways were significantly enriched. T cells CD8+ were mainly enriched in the normal tissues compared to the myocardial infarction tissues. Meanwhile, the T cells CD4+ memory resting were highly enriched in the myocardial infarction tissues compared to the normal tissues. Experimental validation of miRNAs and mRNAs contributed to the identification of 4 miRNAs and 12 mRNAs that may play a crucial role in the DOX-induced myocardial infarction cell model. Our study successfully identified several genes that may be related to myocardial infarction progression.

Abstract Background Lung cancer is one of the most lethal malignant tumors that endangers human health. Lung adenocarcinoma (LUAD) has increased dramatically in recent decades, accounting for nearly 40% of all lung cancer cases. Increasing evidence points to the importance of the competitive endogenous RNA (ceRNA) intrinsic mechanism in various human cancers. However, behavioral characteristics of the ceRNA network in lung adenocarcinoma need further study. Methods Groups based on SLC2A1 expression were used in this study to identify associated ceRNA networks and potential prognostic markers in lung adenocarcinoma. The Cancer Genome Atlas (TCGA) database was used to obtain the patients' lncRNA, miRNA, and mRNA expression profiles, as well as clinical data. Informatics techniques were used to investigate the effect of hub genes on prognosis. The Cox regression analyses were performed to evaluate the prognostic effect of hub genes. The methylation, GSEA, and immune infiltration analyses were utilized to explore the potential mechanisms of the hub gene. The CCK-8, transwell, and colony formation assays were performed to detect the proliferation and invasion of lung cancer cells. Results We eventually identified the ITGB1-DT/ARNTL2 axis as an independent fact may promote lung adenocarcinoma progression. Furthermore, methylation analysis revealed that hypo-methylation may cause the dysregulated ITGB1-DT/ARNTL2 axis, and immune infiltration analysis revealed that the ITGB1-DT/ARNTL2 axis may affect the immune microenvironment and the progression of lung adenocarcinoma. The CCK-8, transwell, and colonu formation assays suggested that ITGB1-DT/ARNTL2 promotes the progression of lung adenocarcinoma. And hsa-miR-30b-3p reversed the ITGB1/ARNTL2-mediated oncogenic processes. Conclusion Our study identified the ITGB1-DT/ARNTL2 axis as a novel prognostic biomarker affects the prognosis of lung adenocarcinoma.

Abstract Mounting evidence has shown that long noncoding RNAs (lncRNAs) play critical roles in carcinogenesis and tumor progression. SNHG12 has been identified in multiple types of malignant tumors. However, the role of SNHG12 in human non‐small cell lung cancer (NSCLC) is poorly characterized, and the relevant underlying mechanism remains unclear. The expression levels of SNHG12, miR‐101‐3p, and CUL4B in collected human NSCLC tumor tissues and NSCLC cell lines were tested via qRT‐PCR. Then, NSCLC cellular proliferation, migration and invasion were determined, followed by MTT, scratch and Transwell assays. Dual‐luciferase reporter assays and RNA pulldown assays were adopted to explore the target site. Moreover, western blotting was performed to detect the relevant protein expression concerning the CUL4B/PI3K/AKT pathway. This study clarified that SNHG12 knockdown significantly reduced proliferation, migration, invasion and EMT of NSCLC cells. Our data indicated that SNHG12 targeted and negatively regulated miR‐101‐3p, and this depletion reversed the inhibitory effect of si‐SNHG12 on NSCLC cells. Furthermore, CUL4B was confirmed as a functional target of miR‐101‐3p, and its knockdown resulted in a strong alleviation of the NSLCL cell phenotype, which was enhanced by the silencing of miR‐101‐3p. Mechanistically, we found that SNHG12 regulated miR‐101‐3p to modulate the PI3K/AKT pathway mediated by CUL4B.These observations suggested that lncRNA SNHG12‐mediated miR‐101‐3p downregulation regulated the malignant phenotype of NSCLC cells by targeting CUL4B through the PI3K/AKT pathway, which may present a path to novel therapeutic strategies for NSCLC therapy.

Septic cardiomyopathy (SCM) is severe organ dysfunction caused by sepsis that is associated with poor prognosis, and its pathobiological mechanisms remain unclear. Autophagy is a biological process that has recently been focused on SCM, yet the current understanding of the role of dysregulated autophagy in the pathogenesis of SCM remains limited and uncertain. Exploring the molecular mechanisms of disease based on the transcriptomes of human pathological samples may bring the closest insights. In this study, we analyzed the differential expression of autophagy-related genes in SCM based on the transcriptomes of human septic hearts, and further explored their potential crosstalk and functional pathways. Key functional module and hub genes were identified by constructing a protein–protein interaction network. Eight key genes (CCL2, MYC, TP53, SOD2, HIF1A, CTNNB1, CAT, and ADIPOQ) that regulate autophagy in SCM were identified after validation in a lipopolysaccharide (LPS)-induced H9c2 cardiomyoblast injury model, as well as the autophagic characteristic features. Furthermore, we found that key genes were associated with abnormal immune infiltration in septic hearts and have the potential to serve as biomarkers. Finally, we predicted drugs that may play a protective role in SCM by regulating autophagy based on our results. Our study provides evidence and new insights into the role of autophagy in SCM based on human septic heart transcriptomes, which would be of great benefit to reveal the molecular pathological mechanisms and explore the diagnostic and therapeutic targets for SCM.

Septic cardiomyopathy (SCM) is a cardiac dysfunction caused by severe sepsis and septic shock that increases the risk of heart failure and death and its molecular mechanism remains unclear. Ferroptosis, a novel form of programmed cell death, has been reported to be present in the heart tissue of patients with sepsis, which demonstrated that ferroptosis may be a potential mechanism of myocardial injury in SCM. Therefore, we explored the role of ferroptosis-related genes (FRGs) in SCM and aimed to identify pivotal ferroptosis-related targets in SCM and potential therapeutic targets involved in the pathological process of SCM. To explore the regulatory mechanisms of ferroptosis in SCM, we identified differentially expressed genes (DEGs) in SCM and FRGs by bioinformatics analysis, and further identified hub genes. And the crucial microRNAs (miRNAs)-FRGs regulatory network was subsequently constructed. Finally, several candidate drugs associated with the hub genes were predicted, and Real-time quantitative reverse Transcription PCR (qRT-PCR) and western blotting analysis were performed to confirm the abnormal expression of hub genes. In this study, we identified several FRGs that may be involved in the pathogenesis of SCM, which helps us further clarify the role of ferroptosis in SCM and deeply understand the molecular mechanisms and potential therapeutic targets of SCM.

Aortic dissection (AD) is a catastrophic cardiovascular emergency with a poor prognosis, and little preceding symptoms. Abnormal lipid metabolism is closely related to the pathogenesis of AD. However, comprehensive lipid alterations related to AD pathogenesis remain unclear. Moreover, there is an urgent need for new or better biomarkers for improved risk assessment and surveillance of AD. Therefore, an untargeted lipidomic approach based on ultra-high-performance liquid chromatograph-mass spectrometry was employed to unveil plasma lipidomic alterations and potential biomarkers for AD patients in this study. We found that 278 of 439 identified lipid species were significantly altered in AD patients (n = 35) compared to normal controls (n = 32). Notably, most lipid species, including fatty acids, acylcarnitines, cholesteryl ester, ceramides, hexosylceramides, sphingomyelins, lysophosphatidylcholines, lysophosphatidylethanolamines, phosphatidylcholines, phosphatidylinositols, diacylglycerols, and triacylglycerols with total acyl chain carbon number ≥54 and/or total double bond number ≥4 were decreased, whereas phosphatidylethanolamines and triacylglycerols with total double bond number

Acute myocardial infarction is a life-threatening condition with high mortality and complication rates. Although myocardial reperfusion can preserve ischemic myocardial tissue, it frequently exacerbates tissue injury, a phenomenon known as ischemia-reperfusion injury (IRI). However, the underlying pathological mechanisms of IRI remain to be completely understood. Ferroptosis is a novel type of regulated cell death that is associated with various pathological conditions, including angiocardiopathy. The purpose of this article was to elucidate the possible mechanistic role of ferroptosis in IRI through bioinformatics analysis and experimental validation. Healthy and IRI heart samples were screened for differentially expressed ferroptosis-related genes and functional enrichment analysis was performed to determine the potential crosstalk and pathways involved. A protein-protein interaction network was established for IRI, and 10 hub genes that regulate ferroptosis, including HIF1A, EGFR, HMOX1, and ATF3 were identified. In vitro, an anoxia/reoxygenation (A/R) injury model was established using H9c2 cardiomyoblasts to validate the bioinformatics analysis results, and extensive ferroptosis was detected. A total of 4 key hub genes and 3 key miRNAs were also validated. It was found that IRI was related to the aberrant infiltration of immune cells and the small-molecule drugs that may protect against IRI by preventing ferroptosis were identified. These results provide novel insights into the role of ferroptosis in IRI, which can help identify novel therapeutic targets. [ABSTRACT FROM AUTHOR]

Nuclear receptor binding SET domain 2 (NSD2)-mediated metabolic reprogramming has been demonstrated to regulate oncogenesis via catalyzing the methylation of histones. The present study aimed to investigate the role of NSD2-mediated metabolic abnormality in pulmonary arterial hypertension (PAH). Monocrotaline (MCT)-induced PAH rat model was established and infected with adeno-associated virus carrying short hairpin RNA (shRNA) targeting NSD2. Hemodynamic parameters, ventricular function, and pathology were evaluated by microcatheter, echocardiography, and histological analysis. Metabolomics changes in lung tissue were analyzed by LC-MS. The results showed that silencing of NSD2 effectively ameliorated MCT-induced PAH and right ventricle dysfunction, and partially reversed pathological remodeling of pulmonary artery and right ventricular hypertrophy. In addition, the silencing of NSD2 markedly reduced the di-methylation level of H3K36 (H3K36me2 level) and inhibited autophagy in pulmonary artery. Non-targeted LC-MS based metabolomics analysis indicated that trehalose showed the most significant change in lung tissue. NSD2-regulated trehalose mainly affected ABC transporters, mineral absorption, protein digestion and absorption, metabolic pathways, and aminoacyl-tRNA biosynthesis. In conclusion, we reveal a new role of NSD2 in the pathogenesis of PAH related to the regulation of trehalose metabolism and autophagy via increasing the H3K36me2 level. NSD2 is a promising target for PAH therapy. [ABSTRACT FROM AUTHOR]

We consider a multivariate Markov-switching GARCH model which allows for regime-specific volatility dynamics, leverage effects, and correlation structures. Conditions for stationarity and expressions for the moments of the process are derived. A Lagrange Multiplier test against misspecification of the within-regime correlation dynamics is proposed, and a simple recursion for multi-step-ahead conditional covariance matrices is deduced. We use this methodology to model the dynamics of the joint distribution of global stock market and real estate equity returns. The empirical analysis highlights the importance of the conditional distribution in Markovswitching time series models. Specifications with Student's t innovations dominate their Gaussian counterparts both in- and out-of-sample. The dominating specification appears to be a two-regime Student's t process with correlations which are higher in the turbulent (high-volatility) regime. [ABSTRACT FROM AUTHOR]

A natural generalization of the first-order GARCH processes family introduced in 1999 to allow for higher-order past errors and conditional variances on the current conditional variance equation is proposed. This new family of GARCH processes includes many well-known GARCH processes. A sufficient and necessary condition for the existence of stationary solution of the family of GARCH processes is given. In particular, we proved the stationarity of the so-called family of IGARCH processes. [ABSTRACT FROM AUTHOR]

This paper investigates stationarity of the so-called integrated Markov-switching generalized autoregressive conditionally heteroskedastic (GARCH) process, which is an important subclass of the Markov-switching GARCH process introduced by Francq, Roussignol, and Zakoïan (2001, Journal of Time Series Analysis 22, 197-220) and a Markov-switching version of the integrated GARCH (IGARCH) process.We show that, like the classical IGARCH process, a stationary solution with infinite variance for the integrated Markov-switching GARCH process may exist. To this purpose, an alternative condition for the existence of a strictly stationary solution of the Markov-switching GARCH process is presented, and some results obtained in Hennion (1997, Annals of Probability 25, 1545-1587) are employed. In addition, we also discuss conditions for the existence of a strictly stationary solution of the Markov-switching GARCH process with finite variance, which is a modification of Theorem 2 in Francq et al. (2001). [ABSTRACT FROM AUTHOR]

In this paper, some structural properties of a family of generalized autoregressive conditionally heteroskedastic (GARCH) processes are considered. First, a sufficient and necessary condition for the strict stationarity of this family of GARCH processes is given. Second, some simple conditions for the existence of the moments of the family of GARCH processes are also derived. Finally, we describe the tail of the marginal distribution of the family of GARCH processes. [ABSTRACT FROM AUTHOR]

This article investigates some structural properties of the Markov-switching GARCH process introduced by Haas, Mittnik, and Paolella. First, a sufficient and necessary condition for the existence of the weakly stationary solution of the process is presented. The solution is weakly stationary, and the causal expansion of the Markov-switching GARCH process is also established. Second, the general conditions for the existence of any integer-order moment of the square of the process are derived. The technique used in this article for the weak stationarity and the high-order moments of the process is different from that used by Haas, Mittnik, and Paolella and avoids the assumption that the process started in the infinite past with finite variance. Third, a sufficient and necessary condition for the strict stationarity of the Markov switching GARCH process with possibly infinite variance is given. Finally, the strict stationarity of the so-called integrated Markov-switching GARCH process is also discussed. [ABSTRACT FROM AUTHOR]

Objective: Although growing evidences have showed that long non-coding RNA (lncRNAs) plasmacytoma variant translocation 1 (PVT1) plays a critical role in the progression of non-small cell lung cancer (NSCLC), there are still many unsolved mysteries remains to be deeply elucidated. This study aimed to find a new underlying mechanism of PVT1 in regulating the tumorigenesis and development of NSCLC. Materials and Methods: In this experimental study, Quantitative reverse transcription polymerase chain reaction (qRTPCR) was used to profile the expression of PVT1 in NSCLC tissues and cells. The effects of PVT1 on cell growth, migration and invasion were detected by colony formation assay, Matrigel-free transwell and Matrigel transwell assays, respectively. Changes of the key protein expression in Hippo and NOTCH signaling pathways, as well as epithelialmesenchymal transition (EMT) markers, were analyzed using western blot. Interaction of PVT1 with enhancer of zeste homolog 2 (EZH2) was verified by RNA pull-down, and their binding to the downstream targets was detected by Chromatin Immunoprecipitation (ChIP) assays. Results: These results showed that PVT1 was up-regulated in NSCLC tissue and cell lines, promoting NSCLC cell proliferation, migration and invasion. Knockdown of PVT1 inhibited the expression of Yes-associated protein 1 (YAP1) and NOTCH1 signaling activation. Further, we have confirmed that PVT1 regulated expression of YAP1 through EZH2-mediated miR-497 promoter methylation resulting in the inhibition of miR-497 transcription and its target YAP1 upregulation, and finally NOTCH signaling pathway was activated, which promoted EMT and invasion and metastasis. Conclusions: These results suggested that lncRNA PVT1 promotes NSCLC metastasis through EZH2-mediated activation of Hippo/NOTCH1 signaling pathways. This study provides a new opportunity to advance our understanding in the potential mechanism of NSCLC development. [ABSTRACT FROM AUTHOR]