Shenlian extract attenuates myocardial ischaemia-reperfusion injury via inhibiting M1 macrophage polarization by silencing miR-155

BMSC‑derived exosome‑mediated miR‑25‑3p delivery protects against myocardial ischemia/reperfusion injury by constraining M1‑like macrophage polarization

Myocardial ischemia/reperfusion injury (MIRI) is a significant challenge in the management of myocardial ischemic disease. Extensive evidence suggests that the macrophage‑mediated inflammatory response may play a vital role in MIRI. Mesenchymal stem cells and, in particular, exosomes derived from these cells, may be key mediators of myocardial injury and repair. However, whether exosomes protect the heart by regulating the polarization of macrophages and the exact mechanisms involved are poorly understood. The present study aimed to determine whether exosomes secreted by bone marrow mesenchymal stem cells (BMSC‑Exo) harboring miR‑25‑3p can alter the phenotype of macrophages by affecting the JAK2/STAT3 signaling pathway, which reduces the inflammatory response and protects against MIRI. An in vivo MIRI model was established in rats by ligating the anterior descending region of the left coronary artery for 30 min followed by reperfusion for 120 min, and BMSC‑Exo carrying miR‑25‑3p (BMSC‑Exo‑25‑3p) were administered through tail vein injection. A hypoxia‑reoxygenation model of H9C2 cells was established, and the cells were cocultured with BMSC‑Exo‑25‑3p in vitro. The results of the present study demonstrated that BMSC‑Exo or BMSC‑Exo‑25‑3p could be taken up by cardiomyocytes in vivo and H9C2 cells in vitro. BMSC‑Exo‑25‑3p demonstrated powerful cardioprotective effects by decreasing the cardiac infarct size, reducing the incidence of malignant arrhythmias and attenuating myocardial enzyme activity, as indicated by lactate dehydrogenase and creatine kinase levels. It induced M1‑like macrophage polarization after myocardial ischemia/reperfusion (I/R), as evidenced by the increase in iNOS expression through immunofluorescence staining and upregulation of proinflammatory cytokines through RT‑qPCR, such as interleukin‑1β (IL‑1β) and interleukin‑6 (IL‑6). As hypothesized, BMSC‑Exo‑25‑3p inhibited M1‑like macrophage polarization and proinflammatory cytokine expression while promoting M2‑like macrophage polarization. Mechanistically, the JAK2/STAT3 signaling pathway was activated after I/R in vivo and in LPS‑stimulated macrophages in vitro, and BMSC‑Exo‑25‑3p pretreatment inhibited this activation. The results of the present study indicate that the attenuation of MIRI by BMSC‑Exo‑25‑3p may be related to JAK2/STAT3 signaling pathway inactivation and subsequent inhibition of M1‑like macrophage polarization.

Macrophage dynamics in prostate cancer: Molecular to therapeutic insights

This review provides an in-depth examination of the role that tumor-associated macrophages (TAMs) play in the progression of prostate cancer (PCa), with a particular focus on the factors influencing the polarization of M1 and M2 macrophages and the implications of targeting these cells for cancer progression. The development and prognosis of PCa are significantly influenced by the behavior of macrophages within the tumor microenvironment. M1 macrophages typically exhibit anti-tumor properties by secreting pro-inflammatory cytokines such as interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α), thereby enhancing the immune response. Conversely, M2 macrophages contribute to tumor cell migration and invasion through the production of factors like arginase-1 (Arg1) and interleukin-10 (IL-10). This review not only explores the diverse factors that affect macrophage polarization but also delves into the potential therapeutic strategies targeting macrophage polarization, including the critical roles of non-coding RNA and exosomes in regulating this process. The polarization state of macrophages is highlighted as a key determinant in PCa progression, offering a novel perspective for clinical treatment. Future research should concentrate on gaining a deeper understanding of the molecular mechanisms underlying macrophage polarization and on developing effective targeted therapeutic strategies. The exploration of the potential of combination therapies to improve treatment efficacy is also emphasized. By emphasizing the importance of macrophages as a therapeutic target in PCa, this review aims to provide valuable insights and research directions for clinicians and researchers.

MicroRNA-155 and exosomal microRNA-155: Small pieces in the cardiovascular diseases puzzle

MicroRNAs (miRs, miRNAs) are known to have a part in various human illnesses, such as those related to the heart. One particular miRNA, miR-155, has been extensively studied and has been found to be involved in hematopoietic lineage differentiation, immunity, viral infections, inflammation, as well as vascular remodeling. These processes have all been connected to cardiovascular diseases, including heart failure, diabetic heart disease, coronary artery disease, and abdominal aortic aneurysm. The impacts of miR-155 depend on the type of cell it is acting on and the specific target genes involved, resulting in different mechanisms of disease. Although, the exact part of miR-155 in cardiovascular illnesses is yet not fully comprehended, as some studies have shown it to promote the development of atherosclerosis while others have shown it to prevent it. As a result, to comprehend the underlying processes of miR-155 in cardiovascular disorders, further thorough study is required. It has been discovered that exosomes that could be absorbed by adjacent or distant cells, control post-transcriptional regulation of gene expression by focusing on mRNA. Exosomal miRNAs have been found to have a range of functions, including participating in inflammatory reactions, cell movement, growth, death, autophagy, as well as epithelial-mesenchymal transition. An increasing amount of research indicates that exosomal miRNAs are important for cardiovascular health and have a major role in the development of a number of cardiovascular disorders, including pulmonary hypertension, atherosclerosis, acute coronary syndrome, heart failure, and myocardial ischemia-reperfusion injury. Herein the role of miR-155 and its exosomal form in heart diseases are summarized.

Islet-resident macrophage-derived miR-155 promotes β cell decompensation via targeting PDX1

Chronic inflammation is critical for the initiation and progression of type 2 diabetes mellitus via causing both insulin resistance and pancreatic β cell dysfunction. miR-155, highly expressed in macrophages, is a master regulator of chronic inflammation. Here we show that blocking a macrophage-derived exosomal miR-155 (MDE-miR-155) mitigates the insulin resistances and glucose intolerances in high-fat-diet (HFD) feeding and type-2 diabetic db/db mice. Lentivirus-based miR-155 sponge decreases the level of miR-155 in the pancreas and improves glucose-stimulated insulin secretion (GSIS) ability of β cells, thus leading to improvements of insulin sensitivities in the liver and adipose tissues. Mechanistically, miR-155 increases its expression in HFD and db/db islets and is released as exosomes by islet-resident macrophages under metabolic stressed conditions. MDE-miR-155 enters β cells and causes defects in GSIS function and insulin biosynthesis via the miR-155-PDX1 axis. Our findings offer a treatment strategy for inflammation-associated diabetes via targeting miR-155.

Targeting the JAK2/STAT3 signaling pathway with natural plants and phytochemical ingredients: A novel therapeutic method for combatting cardiovascular diseases

The aim of this article is to introduce the roles and mechanisms of the JAK2/STAT3 pathway in various cardiovascular diseases, such as myocardial fibrosis, cardiac hypertrophy, atherosclerosis, myocardial infarction, and myocardial ischemiareperfusion. In addition, the effects of phytochemical ingredients and different natural plants, mainly traditional Chinese medicines, on the regulation of different cardiovascular diseases via the JAK2/STAT3 pathway are discussed. Surprisingly, the JAK2 pathway has dual roles in different cardiovascular diseases. Future research should focus on the dual regulatory effects of different phytochemical ingredients and natural plants on JAK2 to pave the way for their use in clinical trials.

Therapeutic Role of Chinese Medicine Targeting Nrf2/HO-1 Signaling Pathway in Myocardial Ischemia/Reperfusion Injury

Acute myocardial infarction (AMI), characterized by high incidence and mortality rates, poses a significant public health threat. Reperfusion therapy, though the preferred treatment for AMI, often exacerbates cardiac damage, leading to myocardial ischemia/reperfusion injury (MI/RI). Consequently, the development of strategies to reduce MI/RI is an urgent priority in cardiovascular therapy. Chinese medicine, recognized for its multi-component, multi-pathway, and multi-target capabilities, provides a novel approach for alleviating MI/RI. A key area of interest is the nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. This pathway is instrumental in regulating inflammatory responses, oxidative stress, apoptosis, endoplasmic reticulum stress, and ferroptosis in MI/RI. This paper presents a comprehensive overview of the Nrf2/HO-1 signaling pathway's structure and its influence on MI/RI. Additionally, it reviews the latest research on leveraging Chinese medicine to modulate the Nrf2/HO-1 pathway in MI/RI treatment.

The macrophage polarization by miRNAs and its potential role in the treatment of tumor and inflammation (Review)

The characteristics of monocyte/macrophage lineage are diversity and plasticity, mainly manifested by M1 and M2 subtypes in the body tissues, and playing different roles in the immunity. In the polarization process of macrophages, the classic molecular mechanism is related to sequential transcription factors. Whether in tumor or inflammatory local microenvironment, the pathological factors of the local microenvironment often affect the polarization of M1 and M2 macrophages, and participate in the occurrence and development of these pathological processes. In recent years, a growing number of research results demonstrated that non‑coding RNA (ncRNA) also participates in the polarization process of macrophages, in addition to traditional cytokines and transcriptional regulation signal pathway molecules. Among numerous ncRNAs, microRNAs (miRNAs) have attracted more attention from scholars both domestically and internationally, and significant progress has been made in basic and clinical research. Therefore, for improved understanding of the molecular mechanism of miRNAs in macrophage polarization and analysis of the potential value of this regulatory pathway in tumor and inflammatory intervention therapy, a comprehensive review of the progress of relevant literature research was conducted and some viewpoints and perspectives were proposed.

Macrophage Polarization and the Regulation of Bone Immunity in Bone Homeostasis

Bone homeostasis is a dynamic equilibrium state of bone formation and absorption, ensuring skeletal development and repair. Bone immunity encompasses all aspects of the intersection between the skeletal and immune systems, including various signaling pathways, cytokines, and the crosstalk between immune cells and bone cells under both homeostatic and pathological conditions. Therefore, as key cell types in bone immunity, macrophages can polarize into classical pro-inflammatory M1 macrophages and alternative anti-inflammatory M2 macrophages under the influence of the body environment, participating in the regulation of bone metabolism and playing various roles in bone homeostasis. M1 macrophages can not only act as precursors of osteoclasts (OCs), differentiate into mature OCs, but also secrete pro-inflammatory cytokines to promote bone resorption; while M2 macrophages secrete osteogenic factors, stimulating the differentiation and mineralization of osteoblast precursors and mesenchymal stem cells (MSCs), and subsequently increase bone formation. Once the polarization of macrophages is imbalanced, the resulting immune dysregulation will cause inflammatory stimulation, and release a large amount of inflammatory factors affecting bone metabolism, leading to pathological conditions such as osteoporosis (OP), rheumatoid arthritis (RA), and steroid-induced femoral head necrosis (SANFH). In this review, we introduce the signaling pathways and related factors of macrophage polarization, as well as their relationships with immune factors, OB, OC, and MSC. We also discuss the roles of macrophage polarization and bone immunity in various diseases of bone homeostasis imbalance, as well as the factors regulating them, which may help to develop new methods for treating bone metabolic disorders.

[Akt2 inhibitor promotes M2 macrophage polarization in rats with periapical inflammation by reducing miR-155-5p expression]

OBJECTIVE

To investigate the effect of Akt2 inhibitor on macrophage polarization in the periapical tissue in a rat model of periapical inflammation.

METHODS

Rat models of periapical inflammation were established in 28 normal SD rats by opening the pulp cavity of the mandibular first molars, followed by injection of normal saline and Akt2 inhibitor into the left and right medullary cavities, respectively. Four rats without any treatment served as the healthy control group. At 7, 14, 21 and 28 days after modeling, 7 rat models and 1 control rat were randomly selected for observation of inflammatory infiltration in the periapical tissues by X-ray and HE staining. Immunohistochemistry was used to detect the expression and localization of Akt2, macrophages and the inflammatory mediators. RT-PCR was performed to detect the mRNA expressions of Akt2, CD86, CD163, inflammatory mediators, miR-155-5p and C/EBPβ to analyze the changes in macrophage polarization.

RESULTS

X-ray and HE staining showed that periapical inflammation was the most obvious at 21 days after modeling in the rats. Immunohistochemistry and RT-PCR showed that compared with those in the control rats, the expressions of Akt2, CD86, CD163, miR-155-5p, C/EBPβ, and IL-10 increased significantly in the rat models at 21 days (P < 0.05). Compared with saline treatment, treatment with the Akt2 inhibitor significantly decreased the expression levels of Akt2, CD86, miR-155-5p and IL-6 and the ratio of CD86+M1/CD163+M2 macrophages (P < 0.05) and increased the expression levels of CD163, C/EBPβ and IL-10 in the rat models (P < 0.05).

CONCLUSION

Inhibition of Akt2 can delay the progression of periapical inflammation in rats and promote M2 macrophage polarization in the periapical inflammatory microenvironment possibly by reducing miR-155-5p expression and activating the expression of C/EBPβ in the Akt signaling pathway.

The Role of ncRNAs in Cardiac Infarction and Regeneration

Myocardial infarction is the most prevalent cardiovascular disease worldwide, and it is defined as cardiomyocyte cell death due to a lack of oxygen supply. Such a temporary absence of oxygen supply, or ischemia, leads to extensive cardiomyocyte cell death in the affected myocardium. Notably, reactive oxygen species are generated during the reperfusion process, driving a novel wave of cell death. Consequently, the inflammatory process starts, followed by fibrotic scar formation. Limiting inflammation and resolving the fibrotic scar are essential biological processes with respect to providing a favorable environment for cardiac regeneration that is only achieved in a limited number of species. Distinct inductive signals and transcriptional regulatory factors are key components that modulate cardiac injury and regeneration. Over the last decade, the impact of non-coding RNAs has begun to be addressed in many cellular and pathological processes including myocardial infarction and regeneration. Herein, we provide a state-of-the-art review of the current functional role of diverse non-coding RNAs, particularly microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in different biological processes involved in cardiac injury as well as in distinct experimental models of cardiac regeneration.