High relative humidity environment alleviates hypoxia-induced pulmonary arterial hypertension in mice.

The environment has long been considered a crucial factor influencing the onset and progression of pulmonary diseases. Environmental therapy is also a practical treatment approach for many conditions. While research has explored the effects of factors like air pressure and oxygen concentration on pulmonary arterial hypertension (PAH), the impact of air humidity on PAH has not been investigated. In this study, we examined the role of different air humidity levels in a mouse model of PAH by controlling relative humidity. We induced PAH in mice using 10 % hypoxia, which led to significant thickening of the pulmonary vasculature, elevated right ventricular systolic pressure, and an increased right ventricular hypertrophy index (RVHI). However, when exposed to an environment with 80-95 % relative humidity, there was a marked reduction in the extent of pulmonary vascular remodeling, decreased vascular thickening, and lower RVHI, effectively preserving right heart function. Notably, changes in the Bmpr2/Tgf-ß signaling pathway were significant and may play a pivotal role in this protective effect. In summary, our findings indicate that high relative humidity confers a protective effect on hypoxia-induced PAH in mice, providing novel insights into potential treatments for PAH.

Analysis and prediction of research hotspots and trends in heart failure research.

Background and objectives: Comprehensive data analyses in heart failure research can provide academics with information and help policymakers formulate relevant policies. We collected data from reports published between 1945 and 2021 to identify research topics, trends, and cross-domains in the heart failure disease literature. Methods: Text fragments were extracted and clustered from the titles and abstracts in 270617 publications using artificial intelligence techniques. Two algorithms were used to corroborate the results and ensure that they were reliable. Experts named themes and document clusters based on the results of these semiautomated methods. Using consistent methods, we identified and flagged 107 heart failure topics and 16 large document clusters (divided into two groups by time). The annual vocabularies of research hotspots were calculated to draw attention to niche research fields. Results: Clinical research is an expanding field, followed by basic research and population research. The most frequently raised issues were intensive care treatment for heart failure, applications of artificial intelligence technologies, cardiac assist devices, stem cells, genetics, and regional distribution and use of heart failure-related health care. Risk scoring and classification, care for patients, readmission, health economics of treatment and care, and cell regeneration and signaling pathways were among the fastest-growing themes. Drugs, signaling pathways, and biomarkers were all crucial issues for clinical and basic research in the entire population. Studies on intelligent medicine and telemedicine, interventional therapy for valvular disease, and novel coronavirus have emerged recently. Conclusion: Clinical and population research is increasingly focusing on the customization of intelligent treatments, improving the quality of patients' life, and developing novel treatments. Basic research is increasingly focusing on regenerative medicine, translational medicine, and signaling pathways. Additionally, each research field exhibits mutual fusion characteristics. Medical demands, new technologies, and social support are all potential drivers for these changes.

Role and mechanism of FLT4 in high-fat diet-induced obesity in mice.

The FLT4 gene plays an important role in the onset and progression of obesity and is involved in the structure and function of lymphatic vessels. By inducing a mouse obesity model with a high-fat diet and knocking out the FLT4 gene, which is associated with lymphatic vessel growth in mice, FLT4+/- mice were found to be susceptible to high-fat diet-induced obesity, with significant accumulation of visceral fat. BODIPY™ FL C16 imaging revealed dilated and branched mesenteric lymphatic vessels in FLT4+/- mice. Immunofluorescence staining showed that FLT4+/- exacerbated the morphological abnormalities of lymphatic vessels and submucosal lymphatic vessels in visceral adipose tissue of obese mice, accompanied by macrophage infiltration around lymphatic vessels. In addition, FLT4 knock down increased the proportion of M1-type macrophages in the adipose tissue of the epididymis, indicating significant chronic inflammation in FLT4+/- obese mice. These findings provide new evidence for the involvement of lymphatic vessel morphological abnormalities in the onset and progression of obesity and highlight the importance of further investigation of FLT4 to better understand the mechanism of HFD-induced obesity and to develop related treatments.

Exercise training ameliorates myocardial phenotypes in heart failure with preserved ejection fraction by changing N6-methyladenosine modification in mice model.

Heart failure with preserved ejection fraction (HFpEF) shows complicated and not clearly defined etiology and pathogenesis. Although no pharmacotherapeutics have improved the survival rate in HFpEF, exercise training has become an efficient intervention to improve functional outcomes. Here, we investigated N6-methyladenosine (m6A) RNA methylation modification in a "two-hit" mouse model with HFpEF and HFpEF with exercise (HFpEF + EXT). The manner of m6A in HFpEF and HFpEF + EXT hearts was explored via m6A-specific methylated RNA immunoprecipitation followed by high-throughput and RNA sequencing methods. A total amount of 3992 novel m6A peaks were spotted in HFpEF + EXT, and 426 differently methylated sites, including 371 hypermethylated and 55 hypomethylated m6A sites, were singled out for further analysis (fold change >2, p < 0.05). According to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, unique m6A-modified transcripts in HFpEF + EXT were associated with apoptosis-related pathway and myocardial energy metabolism. HFpEF + EXT had higher total m6A levels and downregulated fat mass and obesity-related (FTO) protein levels. Overexpression of FTO cancels out the benefits of exercise in HFpEF + EXT mice by promoting myocyte apoptosis, myocardial fibrosis and myocyte hypertrophy. Totally, m6A is a significant alternation of epitranscriptomic processes, which is also a potentially meaningful therapeutic target.

Changes in N6-Methyladenosine Modification Modulate Diabetic Cardiomyopathy by Reducing Myocardial Fibrosis and Myocyte Hypertrophy.

In this study, we aimed to systematically profile global RNA N6-methyladenosine (m6A) modification patterns in a mouse model of diabetic cardiomyopathy (DCM). Patterns of m6A in DCM and normal hearts were analyzed via m6A-specific methylated RNA immunoprecipitation followed by high-throughput sequencing (MeRIP-seq) and RNA sequencing (RNA-seq). m6A-related mRNAs were validated by quantitative real-time PCR analysis of input and m6A immunoprecipitated RNA samples from DCM and normal hearts. A total of 973 new m6A peaks were detected in DCM samples and 984 differentially methylated sites were selected for further study, including 295 hypermethylated and 689 hypomethylated m6A sites (fold change (FC) > 1.5, P < 0.05). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway analyses indicated that unique m6A-modified transcripts in DCM were closely linked to cardiac fibrosis, myocardial hypertrophy, and myocardial energy metabolism. Total m6A levels were higher in DCM, while levels of the fat mass and obesity-associated (FTO) protein were downregulated. Overexpression of FTO in DCM model mice improved cardiac function by reducing myocardial fibrosis and myocyte hypertrophy. Overall, m6A modification patterns were altered in DCM, and modification of epitranscriptomic processes, such as m6A, is a potentially interesting therapeutic approach.