Mybl2 rejuvenates heart explant-derived cells from aged donors after myocardial infarction

Development of a Mouse Cardiac Sarcoidosis Model Using Carbon Nanotubes

Sarcoidosis, a granulomatous disorder of unknown etiology affecting multiple organs. It is often a benign disease but can have significant morbidity and mortality when the heart is involved (often presenting with clinical manifestations such as conduction irregularities and heart failure). This study addresses a critical gap in cardiac sarcoidosis (CS) research by developing a robust animal model. The absence of a reliable animal model for cardiac sarcoidosis is a significant obstacle in advancing understanding and treatment of this condition. The proposed model utilizes carbon nanotube injection and transverse aortic constriction as stressors. Intramyocardial injection of carbon nanotubes induces histiocytes typical of sarcoid granulomas in the heart but shows limited effects on fibrosis or cardiac function. Priming the immune system with transverse aortic constriction prior to intramyocardial injection of carbon nanotubes enhances cardiac fibrosis, diminishes cardiac function, and impairs cardiac conduction. This novel, easily executable model may serve as a valuable tool for disease profiling, biomarker identification, and therapeutic exploration.

Measuring biological age using a functionally interpretable multi-tissue RNA clock

The quantification of the biological age of cells yields great promises for accelerating the discovery of novel rejuvenation strategies. Here, we present MultiTIMER, the first multi-tissue aging clock that measures the biological, rather than chronological, age of cells from their transcriptional profiles by evaluating key cellular processes. We applied MultiTIMER to more than 70,000 transcriptional profiles and demonstrate that it accurately responds to cellular stressors and known interventions while informing about dysregulated cellular functions.

The role of cellular senescence in cardiac disease: basic biology and clinical relevance

Cellular senescence, classically defined as stable cell cycle arrest, is implicated in biological processes such as embryogenesis, wound healing and ageing. Senescent cells have a complex senescence-associated secretory phenotype (SASP), involving a range of pro-inflammatory factors with important paracrine and autocrine effects on cell and tissue biology. Clinical evidence and experimental studies link cellular senescence, senescent cell accumulation, and the production and release of SASP components with age-related cardiac pathologies such as heart failure, myocardial ischaemia and infarction, and cancer chemotherapy-related cardiotoxicity. However, the precise role of senescent cells in these conditions is unclear and, in some instances, both detrimental and beneficial effects have been reported. The involvement of cellular senescence in other important entities, such as cardiac arrhythmias and remodelling, is poorly understood. In this Review, we summarize the basic biology of cellular senescence and discuss what is known about the role of cellular senescence and the SASP in heart disease. We then consider the various approaches that are being developed to prevent the accumulation of senescent cells and their consequences. Many of these strategies are applicable in vivo and some are being investigated for non-cardiac indications in clinical trials. We end by considering important knowledge gaps, directions for future research and the potential implications for improving the management of patients with heart disease.

Integrated bioinformatics analysis reveals novel key biomarkers in diabetic nephropathy

Objectives:

The underlying molecular mechanisms of diabetic nephropathy have yet not been investigated clearly. In this investigation, we aimed to identify key genes involved in the pathogenesis and prognosis of diabetic nephropathy.

Methods:

We downloaded next-generation sequencing data set GSE142025 from Gene Expression Omnibus database having 28 diabetic nephropathy samples and nine normal control samples. The differentially expressed genes between diabetic nephropathy and normal control samples were analyzed. Biological function analysis of the differentially expressed genes was enriched by Gene Ontology and REACTOME pathways. Then, we established the protein–protein interaction network, modules, miRNA-differentially expressed gene regulatory network and transcription factor-differentially expressed gene regulatory network. Hub genes were validated by using receiver operating characteristic curve analysis.

Results:

A total of 549 differentially expressed genes were detected including 275 upregulated and 274 downregulated genes. The biological process analysis of functional enrichment showed that these differentially expressed genes were mainly enriched in cell activation, integral component of plasma membrane, lipid binding, and biological oxidations. Analyzing the protein–protein interaction network, miRNA-differentially expressed gene regulatory network and transcription factor-differentially expressed gene regulatory network, we screened hub genes MDFI, LCK, BTK, IRF4, PRKCB, EGR1, JUN, FOS, ALB, and NR4A1 by the Cytoscape software. The receiver operating characteristic curve analysis confirmed that hub genes were of diagnostic value.

Conclusions:

Taken above, using integrated bioinformatics analysis, we have identified key genes and pathways in diabetic nephropathy, which could improve our understanding of the cause and underlying molecular events, and these key genes and pathways might be therapeutic targets for diabetic nephropathy.

Rejuvenating the Aging Heart by Enhancing the Expression of the Cisd2 Prolongevity Gene

Aging is the major risk factor for cardiovascular disease, which is the leading cause of mortality worldwide among aging populations. Cisd2 is a prolongevity gene that mediates lifespan in mammals. Previously, our investigations revealed that a persistently high level of Cisd2 expression in mice is able to prevent age-associated cardiac dysfunction. This study was designed to apply a genetic approach that induces cardiac-specific Cisd2 overexpression (Cisd2 icOE) at a late-life stage, namely a time point immediately preceding the onset of old age, and evaluate the translational potential of this approach. Several discoveries are pinpointed. Firstly, Cisd2 is downregulated in the aging heart. This decrease in Cisd2 leads to cardiac dysfunction and impairs electromechanical performance. Intriguingly, Cisd2 icOE prevents an exacerbation of age-associated electromechanical dysfunction. Secondly, Cisd2 icOE ameliorates cardiac fibrosis and improves the integrity of the intercalated discs, thereby reversing various structural abnormalities. Finally, Cisd2 icOE reverses the transcriptomic profile of the aging heart, changing it from an older-age pattern to a younger pattern. Intriguingly, Cisd2 icOE modulates a number of aging-related pathways, namely the sirtuin signaling, autophagy, and senescence pathways, to bring about rejuvenation of the heart as it enters old age. Our findings highlight Cisd2 as a novel molecular target for developing therapies targeting cardiac aging.

Identifying molecular targets for reverse aging using integrated network analysis of transcriptomic and epigenomic changes during aging

Aging is associated with widespread physiological changes, including skeletal muscle weakening, neuron system degeneration, hair loss, and skin wrinkling. Previous studies have identified numerous molecular biomarkers involved in these changes, but their regulatory mechanisms and functional repercussions remain elusive. In this study, we conducted next-generation sequencing of DNA methylation and RNA sequencing of blood samples from 51 healthy adults between 20 and 74 years of age and identified aging-related epigenetic and transcriptomic biomarkers. We also identified candidate molecular targets that can reversely regulate the transcriptomic biomarkers of aging by reconstructing a gene regulatory network model and performing signal flow analysis. For validation, we screened public experimental data including gene expression profiles in response to thousands of chemical perturbagens. Despite insufficient data on the binding targets of perturbagens and their modes of action, curcumin, which reversely regulated the biomarkers in the experimental dataset, was found to bind and inhibit JUN, which was identified as a candidate target via signal flow analysis. Collectively, our results demonstrate the utility of a network model for integrative analysis of omics data, which can help elucidate inter-omics regulatory mechanisms and develop therapeutic strategies against aging.

Construction of a MicroRNA-mRNA Network Underlying Decidualized Endometriotic Cyst Stromal Cells Using Bioinformatics Analysis

Background

Decidualization of ectopic endometrium often leads to the extensive proliferation of local tissue and is easily misdiagnosed as malignant tumors. The study is aimed at constructing a microRNA- (miRNA-) mRNA network underlying decidualized endometriotic cyst stromal cells (ECSCs).

Methods

All data were collected from the Gene Expression Omnibus (GEO) database. Firstly, the differentially expressed genes (DEGs, adj. P-Val < 0.05, | log FC | ≥1) and miRNAs (DEMs, P-Val < 0.05, ∣log FC | ≥1) were analyzed by the limma package. Secondly, we predicted the target genes (TGs) of these DEMs through the TargetScan, miRDB, and miRTarBase databases. The overlapping genes between DEGs and TGs were screened out. Thirdly, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) enrichment analyses of the overlapping genes were performed for integrated discovery, visualization, and annotation. Then, the protein-protein interaction (PPI) network of the overlapping genes was conducted by the STRING database. Finally, we combined the PPI network and the miRNA-mRNA pairs to build a miRNA-mRNA network.

Results

There are 29 DEMs and 523 DEGs. Fourteen overlapping genes were screened out, and these genes were significantly enriched in metabolism and immunity. What is more, a miRNA-mRNA network, including 14 mRNAs and 9 miRNAs, was successfully constructed.

Conclusions

Taken together, the miRNA-mRNA regulatory networks described in this study may provide new insights in the decidualization of ECSCs, suggesting further investigations in novel pathogenic mechanisms.

Mybl2 rejuvenates heart explant-derived cells from aged donors after myocardial infarction

While cell therapy is emerging as a promising option for patients with ischemic cardiomyopathy (ICM), the influence of advanced donor age and a history of ischemic injury on the reparative performance of these cells are not well defined. As such, intrinsic changes that result from advanced donor age and ischemia are explored in hopes of identifying a molecular candidate capable of restoring the lost reparative potency of heart explant‐derived cells (EDCs) used in cell therapy. EDCs were cultured from myocardial biopsies obtained from young or old mice 4 weeks after randomization to experimental myocardial infarction or no intervention. Advanced donor age reduces cell yield while increasing cell senescence and the secretion of senescence‐associated cytokines. A history of ischemic injury magnifies these effects as cells are more senescent and have lower antioxidant reserves. Consistent with these effects, intramyocardial injection of EDCs from aged ischemic donors provided less cell‐mediated cardiac repair. A transcriptome comparison of ICM EDCs shows aging modifies many of the pathways responsible for effective cell cycle control and DNA damage/repair. Over‐expression of the barely explored antisenescent transcription factor, Mybl2, in EDCs from aged ICM donors reduces cell senescence while conferring salutary effects on antioxidant activity and paracrine production. In vivo, we observed an increase in cell retention and vasculogenesis after treatment with Mybl2‐over‐expressing EDCs which improved heart function in infarcted recipient hearts. In conclusion, Mybl2 over‐expression rejuvenates senescent EDCs sourced from aged ICM donors to confer cell‐mediated effects comparable to cells from young nonischemic donors.