The effect of macrophage-cardiomyocyte interactions on cardiovascular diseases and development of potential drugs.

The interaction between macrophages and cardiomyocytes plays an important role not only in maintaining cardiac homeostasis, but also in the development of many cardiovascular diseases (CVDs), such as myocardial infarction (MI) and heart failure (HF). In addition to supporting cardiomyocytes, macrophages and cardiomyocytes have a close and complex relationship. By studying their cross-talk, we can better understand novel mechanisms and target pathogenic mechanisms, and improve the treatment of CVDs. We review macrophage-cardiomyocyte communication through connexin 43 (Cx43)-containing gap junctions (GJs) directly, secreted protein factors indirectly, and discuss the implications of these interactions in cardiac homeostasis and the development of various CVDs, including MI, HF, arrhythmia, cardiac fibrosis and myocarditis. In this section, we review various drugs that work by modulating cytokines or other proteins to reduce inflammation in CVDs. The clinical findings from targeting inflammation in CVDs are also discussed. Additionally, we examine the challenges and opportunities for improving our understanding of macrophage-cardiomyocyte coupling as it relates to pathophysiological disease processes, extending our research scope, and helping identify new molecular targets and improve the effectiveness of existing therapies.

Wogonin mitigates acetaminophen-induced liver injury in mice through inhibition of the PI3K/AKT signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Scutellaria baicalensis Georgi (SBG), a widely used traditional Chinese medicine, exhibits anti-inflammatory and antioxidant properties. Wogonin is one of the primary bioactive components of SBG. Acetaminophen (APAP)-induced liver injury (AILI) represents a prevalent form of drug-induced liver damage and is primarily driven by inflammatory responses and oxidative stress. AIM OF STUDY: To investigate the therapeutic effects of Wogonin on AILI and the underlying mechanisms. MATERIALS AND METHODS: C57BL/6 J mice were pre-treated with Wogonin (1, 2.5, and 5 mg/kg bodyweight) for 3 days, followed by treatment with APAP (300 mg/kg bodyweight). The serum and liver tissue samples were collected at 24 h post-APAP treatment. Bone marrow-derived macrophages and RAW264.7 cells were cultured and pre-treated with Wogonin (5, 10, and 20 µM) for 30 min, followed by stimulation with lipopolysaccharide (LPS; 100 ng/mL) for 3 h. To examine the role of the PI3K/AKT signaling pathway in the therapeutic effect of Wogonin on AILI, mice and cells were treated with LY294002 (a PI3K inhibitor) and MK2206 (an AKT inhibitor). RESULTS: Wogonin pre-treatment dose-dependently alleviated AILI in mice. Additionally, Wogonin suppressed oxidative stress and inflammatory responses. Liver transcriptome analysis indicated that Wogonin primarily regulates immune function and cytokines in AILI. Wogonin suppressed inflammatory responses of macrophages by inhibiting the PI3K/AKT signaling pathway. Consistently, Wogonin exerted therapeutic effects on AILI in mice through the PI3K/AKT signaling pathway. CONCLUSIONS: Wogonin alleviated AILI and APAP-induced hepatotoxicity in mice through the PI3K/AKT signaling pathway.

LncRNA CCRR maintains Ca2+ homeostasis against myocardial infarction through the FTO-SERCA2a pathway.

Cardiac conduction regulatory RNA (CCRR) has been documented as an antiarrhythmic lncRNA in our earlier investigation. This study aimed to evaluate the effects of CCRR on SERCA2a and the associated Ca2+ homeostasis in myocardial infarction (MI). Overexpression of CCRR via AAV9-mediated delivery not only partially reversed ischemia-induced contractile dysfunction but also alleviated abnormal Ca2+ homeostasis and reduced the heightened methylation level of SERCA2a following MI. These effects were also observed in CCRR over-expressing transgenic mice. A conserved sequence domain of CCRR mimicked the protective function observed with the full length. Furthermore, silencing CCRR in healthy mice led to intracellular Ca2+ overloading of cardiomyocytes. CCRR increased SERCA2a protein stability by upregulating FTO expression. The direct interaction between CCRR and FTO protein was characterized by RNA-binding protein immunoprecipitation (RIP) analysis and RNA pulldown experiments. Activation of NFATc3 was identified as an upstream mechanism responsible for CCRR downregulation in MI. This study demonstrates that CCRR is a protective lncRNA that acts by maintaining the function of FTO, thereby reducing the m6A RNA methylation level of SERCA2a, ultimately preserving calcium homeostasis for myocardial contractile function in MI. Therefore, CCRR may be considered a promising therapeutic strategy with a beneficial role in cardiac pathology.

LncRNA CCRR Attenuates Postmyocardial Infarction Inflammatory Response by Inhibiting the TLR Signalling Pathway.

BACKGROUND: Timely and proper suppression of inflammation can effectively reduce myocardial injury and promote the postmyocardial infarction (post-MI) wound-healing process. We have previously found that cardiac conduction regulatory RNA (CCRR), a long noncoding RNA (lncRNA) transcribed by the gene located on chromosome 9, with abundant expression in the heart, elicits antiarrhythmic effects in heart failure, and this is a continuing study on the role of CCRR in MI. METHODS: CCRR was overexpressed in CCRR transgenic mice or after injection of adeno-associated virus-9 (AAV-9). MI surgery was performed, and cardiac function was assessed in vivo by echocardiography, followed by histologic analyses. Western blot analysis and qRT-PCR were performed to investigate the effects of CCRR on macrophages, cardiomyocytes, and cardiomyocytes cocultured with macrophages. Through microarray analysis and RNA-binding protein immunoprecipitation (RIP) and other related techniques were also employed to study the effects of CCRR on Toll-like receptor (TLR)2 and TLR4. RESULTS: We found that CCRR level was significantly decreased with increases in proinflammatory cytokines and activation of the TLR signalling pathway in the heart of the 3-day MI mice. CCRR overexpression downregulated TLR2 and TLR4 in MI and effectively inhibited the inflammatory responses in primary cardiomyocytes and macrophages cultured under hypoxic conditions. Downregulation of CCRR induced excessive inflammatory responses by activating the TLR signalling pathway. CCRR acted by suppressing TLR2 and TLR4 to inhibit the secretion of proinflammatory factors to reduce infarct size, thereby improving cardiac function. CONCLUSIONS: CCRR protected cardiomyocytes against MI injury by suppressing inflammatory response through targeting the TLR signalling pathway.

Research advances on circulating long noncoding RNAs as biomarkers of cardiovascular diseases.

Cardiovascular diseases (CVD) such as myocardial ischemia, myocardial infarction, heart failure, atherosclerosis, hypertension, arrhythmia, and their complications diseases are associated with increased morbidity and mortality, it is necessary to develop new diagnostic markers for CVD. LncRNAs have become a new class of biomarkers in CVD with good development prospects. Numerous studies have confirmed lncRNAs feasibility as diagnostic, prognostic and predictive tools for different types of CVD. In this review, we summarized the available knowledge regarding the clinical application value and pathophysiological mechanism of circulating lncRNA as potential biomarkers of cardiovascular disease. We reviewed the scope of application and changes of circulating lncRNAs such as ZFAS1, CDR1AS, CHAST, UCA1, HOTAIR, MIAT, NEAT1, LIPCAR, H19, NRF, NRON, MHRT, PVT1, Heat2, CASC7, GAS5, MALAT1, APPAT, HIF1A-AS1, KCNQ1OT1, NEXN in different kinds of CVD and discussed their clinical application potential as biomarker, which can help us better understand the mechanism of CVD.