The roles of B cells in cardiovascular diseases

Damage to the heart can start the repair process and cause cardiac remodeling. B cells play an important role in this process. B cells are recruited to the injured place and activate cardiac remodeling through secreting antibodies and cytokines. Different types of B cells showed specific functions in the heart. Among all types of B cells, heart-associated B cells play a vital role in the heart by secreting TGFβ1. B cells participate in the activation of fibroblasts and promote cardiac fibrosis. Four subtypes of B cells in the heart revealed the relationship between the B cells' heterogeneity and cardiac remodeling. Many cardiovascular diseases like atherosclerosis, heart failure (HF), hypertension, myocardial infarction (MI), and dilated cardiomyopathy (DCM) are related to B cells. The primary mechanisms of these B cell-related activities will be discussed in this review, which may also suggest potential novel therapeutic targets.

Effect of obstructive sleep apnea on prognosis in patients with acute coronary syndromes with varying numbers of standard modifiable risk factors: insight from the OSA-ACS study

BACKGROUND

Standard modifiable risk factors (SMuRFs) increase the risk of cardiovascular events in patients with acute coronary syndrome (ACS) and are also strongly associated with obstructive sleep apnea (OSA) in a bidirectional relationship. However, the association of OSA with recurrent cardiovascular events in ACS patients based on the number of SMuRFs remains unclear. Hence, we aimed to elucidate the prognostic implication of OSA in ACS patients stratified by the number of SMuRFs.

METHODS

This was a post hoc analysis of the OSA-ACS study (NCT03362385), including 1927 patients admitted for ACS and undergoing portable sleep monitoring. OSA was defined as an apnea hypopnea index ≥ 15 events/h. The primary endpoint was major adverse cardiovascular and cerebrovascular event (MACCE) including cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina or heart failure, and ischemia-driven revascularization. Cox proportional hazards model and Kaplan-Meier analysis were used to investigated the relationship between OSA and subsequent cardiovascular events after patients were stratified by the number of SMuRFs.

RESULTS

Among 1927 patients enrolled, 130 (6.7%) had no SMuRF, 1264 (65.6%) exhibited 1-2 SMuRFs and 533 (27.7%) presented 3-4 SMuRFs. With the increase of the number of SMuRFs, the proportion of OSA in ACS patients tended to increase (47.7% vs. 51.5% vs. 56.6%), but there was no significant difference between them (P = 0.08). After the stratification of ACS patients via SMuRF numbers and adjustment for confounding factors, fully adjusted Cox regression indicated that OSA increased the risk of MACCE (adjusted HR, 1.65; 95%CI, 1.06-2.57; P = 0.026) and ischemia-driven revascularization (adjusted HR, 2.18; 95%CI, 1.03-4.65; P = 0.042) in ACS patients with 3-4 SMuRFs.

CONCLUSIONS

In hospitalized ACS patients, OSA is associated with an increased risk of MACCE and ischemia-driven revascularization among patients with 3-4 SMuRFs. Therefore, screening for OSA should be emphasized in ACS patients with 3-4 SMuRFs, and intervention trials should be prioritized in these high-risk patients.

Dapagliflozin attenuates myocardial remodeling in hypertension by activating the circadian rhythm signaling pathway

Sodium-glucose cotransporter 2 inhibitor (SGLT2i) is a new kind of antidiabetic drug which has shown beneficial effects in reducing heart failure-related hospitalization and cardiovascular-related mortality. The mechanisms are complicated. Our study aimed to investigate the effects of dapagliflozin on the myocardium of spontaneously hypertensive rats (SHRs) without heart failure. Wistar-Kyoto rats were used as normal controls. SHRs were randomly divided into the SHR group and the -treated group. After 8 weeks of dapagliflozin treatment, the morphology of heart tissues was examined. The mRNA expression profiles were identified via RNA sequencing (RNA-Seq). Various analysis methods were used to find the differentially expressed genes (DEGs) to predict gene function and coexpression. After dapagliflozin treatment, systolic blood pressure was significantly reduced compared with that in the SHR group. Myocardial remodeling was ameliorated compared with that in the SHR group. After dapagliflozin intervention, 75 DEGs (|log2-fold change | > 0 and Q value < 0.05) were identified in the heart tissues compared to the SHR group. Quantitative real-time PCR analysis confirmed that the expression of the circadian rhythm genes Per3, Bhlhe41, and Nr1d1 was significantly upregulated, while the results were coincident with the RNA-Seq results. Dapagliflozin may effectively inhibit myocardial remodeling and regulate blood pressure. The mechanisms may be related to the activation of the circadian rhythm signaling pathway.

Transcriptomic profile analysis of the left atrium in spontaneously hypertensive rats in the early stage

Left atrial remodeling, characterized by enlargement and hypertrophy of the left atrium and increased fibrosis, was accompanied by an increased incidence of atrial fibrillation. While before morphological changes at the early stage of hypertension, how overloaded hypertension influences the transcriptomic profile of the left atrium remains unclear. Therefore, RNA-sequencing was performed to define the RNA expressing profiles of left atrium in spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto (WKY) rats as a control group. We also compared the changes in the RNA expression profiles in SHRs treated with an angiotensin receptor blocker (ARB) and angiotensin receptor-neprilysin inhibitor (ARNI) to assess the distinct effects on the left atrium. In total, 1,558 differentially expressed genes were found in the left atrium between WKY rats and SHRs. Bioinformatics analysis showed that these mRNAs could regulate upstream pathways in atrial remodeling through atrial fibrosis, inflammation, electrical remodeling, and cardiac metabolism. The regulated transcripts detected in the left atrial tissue in both the ARB-treated and ARNI-treated groups were related to metabolism. In contrast to the ARB-treated rates, the transcripts in ARNI-treated rats were mapped to the cyclic guanosine monophosphate-protein kinase G signaling pathway.