Raftlin is recruited by neuropilin-1 to the activated VEGFR2 complex to control proangiogenic signaling

Association between raftlin and presepsin levels with periodontal healthy and disease conditions

OBJECTIVE

The aim of this study was to examine the association between Raftlin and Presepsin levels in periodontal healthy/diseases, hypothesizing a change in their levels. Also, the study aimed to determine their potential role in diagnosing and predicting the prognosis of periodontal diseases.

DESIGN

A cross-sectional study design was used, including 20 periodontally healthy individuals, 21 gingivitis patients, and 21 periodontitis patients. Clinical measurements and gingival crevicular fluid (GCF) sample collection were conducted, and the levels of Raftlin and Presepsin were analyzed. Statistical analysis was performed to evaluate the differences and correlations among the groups.

RESULTS

Raftlin and Presepsin levels displayed significant variations among groups in both total amount (mean values for Raftlin in periodontitis, gingivitis, and healthy were 33.42, 17.45, 7.70 pg/30 s, respectively; for Presepsin, values were 3.98, 3.01, 1.92 pg/30 s, respectively) (p < 0.001) and concentration levels (pg/μl) (p = 0.007 for Raftlin, p = 0.026 for Presepsin). Particularly noteworthy were the concentration distinctions observed exclusively between the periodontitis and healthy groups.

CONCLUSIONS

The present study offers preliminary insights into the presence and variations of raftlin and prepsepsin in the GCF across different periodontal conditions. While these findings hint at a potential role for these markers in periodontal disease, further research is essential to fully understand their diagnostic and prognostic capabilities.

The Efficacy of Nanoparticle Delivery to Hypoxic Solid Tumors by ciRGD Co-Administration Depends on Neuropilin-1 and Neutrophil Levels

The ability to improve nanoparticle delivery to solid tumors is an actively studied domain, where various mechanisms are looked into. In previous work, the authors have looked into nanoparticle size, tumor vessel normalization, and disintegration, and here it is aimed to continue this work by performing an in-depth mechanistic study on the use of ciRGD peptide co-administration. Using a multiparametric approach, it is observed that ciRGD can improve nanoparticle delivery to the tumor itself, but also to tumor cells specifically better than vessel normalization strategies. The effect depends on the level of tumor perfusion, hypoxia, neutrophil levels, and vessel permeability. This work shows that upon characterizing tumors for these parameters, conditions can be selected that can optimally benefit from ciRGD co-administration as a means to improve NP delivery to solid tumors.

Tryptophan metabolite norharman secreted by cultivated Lactobacillus attenuates acute pancreatitis as an antagonist of histone deacetylases

BACKGROUND

Patients with acute pancreatitis (AP) exhibit specific phenotypes of gut microbiota associated with severity. Gut microbiota and host interact primarily through metabolites; regrettably, little is known about their roles in AP biological networks. This study examines how enterobacterial metabolites modulate the innate immune system in AP aggravation.

METHODS

In AP, alterations in gut microbiota were detected via microbiomics, and the Lactobacillus metabolites of tryptophan were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). By culturing Lactobacillus with tryptophan, differential metabolites were detected by LC-MS/MS. Lipopolysaccharide (LPS)-stimulated RAW264.7 cells and mice with cerulein plus LPS-induced AP were used to evaluate the biological effect of norharman on M1 macrophages activation in AP development. Further, RNA sequencing and lipid metabolomics were used for screening the therapeutic targets and pathways of norharman. Confocal microscopy assay was used to detect the structure of lipid rafts. Molecular docking was applied to predict the interaction between norharman and HDACs. Luciferase reporter assays and chromatin immunoprecipitation (ChIP) were used to explore the direct mechanism of norharman promoting Rftn1 expression. In addition, myeloid-specific Rftn1 knockout mice were used to verify the role of Rftn1 and the reversed effect of norharman.

RESULTS

AP induced the dysfunction of gut microbiota and their metabolites, resulting in the suppression of Lactobacillus-mediated tryptophan metabolism pathway. The Lactobacillus metabolites of tryptophan, norharman, inhibited the release of inflammatory factor in vitro and in vivo, as a result of its optimal inhibitory action on M1 macrophages. Moreover, norharman blocked multiple inflammatory responses in AP exacerbation due to its ability to maintain the integrity of lipid rafts and restore the dysfunction of lipid metabolism. The mechanism of norharman's activity involved inhibiting the enzyme activity of histone deacetylase (HDACs) to increase histone H3 at lysine 9/14 (H3K9/14) acetylation, which increased the transcription level of Rftn1 (Raftlin 1) to inhibit M1 macrophages' activation.

CONCLUSIONS

The enterobacterial metabolite norharman can decrease HDACs activity to increase H3K9/14 acetylation of Rftn1, which inhibits M1 macrophage activation and restores the balance of lipid metabolism to relieve multiple inflammatory responses. Therefore, norharman may be a promising prodrug to block AP aggravation.

An overview of receptor endocytosis and signaling

Endocytosis is a cellular process which mediates receptor internalization, nutrient uptake, and the regulation of cell signaling. Microorganisms (many bacteria and viruses) and toxins also use the same process and enter the cells. Generally, endocytosis is considered in the three forms such as phagocytosis (cell eating), pinocytosis (cell drinking), and highly selective receptor-mediated endocytosis (clathrin-dependent and independent). Several endocytic routes exist in an analogous, achieving diverse functions. Most studies on endocytosis have used transformed cells in culture. To visualize the receptor internalization, trafficking, and signaling in subcellular organelles, a green fluorescent protein-tagged receptor has been utilized. It also helps to visualize the endocytosis effects in live-cell imaging. Confocal laser microscopy increases our understanding of receptor endocytosis and signaling. Site-directed mutagenesis studies demonstrated that many short-sequence motifs of the cytoplasmic domain of receptors significantly play a vital role in receptor internalization, subcellular trafficking, and signaling. However, other factors also regulate receptor internalization through clathrin-coated vesicles. Receptor endocytosis can occur through clathrin-dependent and clathrin-independent pathways. This chapter briefly discusses the internalization, trafficking, and signaling of various receptors in normal conditions. In addition, it also highlights the malfunction of the receptor in disease conditions.

Emerging tools for studying receptor endocytosis and signaling

Ligands, agonists, or antagonists use receptor-mediated endocytosis (RME) to reach their intracellular targets. After the internalization of ligand-receptor complexes, it traffics through different subcellular organelles such as early endosome, recycling endosome, lysosome, etc. Further, after the ligand binding to the receptor, different second messengers are generated, such as cGMP, cAMP, IP₃, etc. Several methods have been used, such as radioligand binding assay, western blotting, co-immunoprecipitation (co-IP), qRT-PCR, immunofluorescence and confocal microscopy, microRNA/siRNA, and bioassays to understand the various events, such as internalization, subcellular trafficking, signaling, metabolic degradation, etc. This chapter briefly discusses the key principles and methods used to study internalization, subcellular trafficking, signaling, and metabolic degradation of numerous receptors.

Endocytosis and signaling of 5-HT1A receptor

The neurotransmitter serotonin (also known as 5-hydroxytryptamine, 5-HT) regulates many important physiological as well as pathological functions in the body like psychoemotional, sensation, blood circulation, food intake, autonomic, memory, sleep, pain, etc. 5-HT binds to its receptor 5-HT1A to initiate GTP exchange at the Gi/o protein, which activates the receptor G protein complex. G protein subunits attach to different effectors and generate various responses, such as inhibition of adenyl cyclase enzyme and regulates the opening of Ca⁺⁺ and K⁺ ion channels. Activated signalling cascades activate protein kinase C (PKC) (a second messenger), which further induces the detachment of Gβγ-dependent receptor signaling and leads to 5-HT1A internalization. After internalization, 5-HT1A receptor attaches to the Ras-ERK1/2 pathway. The receptor further trafficks to the lysosome for degradation. Receptor skips the trafficking to the lysosomal compartments and undergoes dephosphorylation. Dephosphorylated receptors now recycled back to the cell membrane. In this chapter, we have discussed the internalization, trafficking and signaling of the 5-HT1A receptor.

Receptor biology: Challenges and opportunities

Receptor biology provides a great opportunity to understand the ligand-receptor signaling involved in health and disease processes. Receptor endocytosis and signaling play a vital role in health conditions. Receptor-based signaling is the main form of communication between cells and cells with the environment. However, if any irregularities happen during these events, the consequences of pathophysiological conditions occur. Various methods are utilized to know structure, function, and regulation of receptor proteins. Further, live-cell imaging and genetic manipulations have aided in the understanding of receptor internalization, subcellular trafficking, signaling, metabolic degradation, etc. Understanding the genetics, biochemistry, and physiology of receptors and ligands is very helpful to explore various aspects such as prognosis, diagnosis, and treatment of disease. However, there are enormous challenges that exist to explore receptor biology further. This chapter briefly discusses the current challenges and emerging opportunities of receptor biology.

Curcumin activates Nrf2/HO-1 signaling to relieve diabetic cardiomyopathy injury by reducing ROS in vitro and in vivo

The hallmark feature of Diabetes mellitus (DM) is hyperglycemia which can lead to excess production of reactive oxygen species (ROS) in the myocardium, contributing to diabetic cardiomyopathy (DCM). Nuclear factor erythroid2-related factor2 (Nrf2), a transcriptional activator, enhances its ability to resist oxidative stress by activating multiple downstream anti-oxidants, anti-inflammatory proteins, and detoxifying enzymes. However, the mechanism of Nrf2 signaling in HG-induced DCM is unclear. In this study, we used HG pretreated H9c2 cells as the experimental basis in vitro, and established a high fat-diet, streptozotocin (STZ) induced Type 2 diabetic rat model in vivo. Meanwhile, we used shRNA-Nrf2 and curcumin (CUR) (as an activator) to affect H9c2 cells, to verify the role of the Nrf2 signaling pathway in DCM. The results showed that the excessive production of ROS caused by HG, which could inhibit the activation of Nrf2-related signaling, resulting in a decrease in cell energy metabolism and an increase in cell apoptosis. Surprisingly, we found that the activation of the Nrf2 signaling pathway significantly increased cardiomyocyte viability, reduced ROS formation, increased antioxidant enzyme activity, and inhibited cardiomyocyte apoptosis. In conclusion, these findings conclusively infer that CUR activation of the Nrf2/HO-1 signaling pathway exerts myocardial protection by reducing ROS formation.

Müller glia-derived exosomal miR-9-3p promotes angiogenesis by restricting sphingosine-1-phosphate receptor S1P1 in diabetic retinopathy

Diabetic retinopathy is a heterogeneous retinal degenerative disease with the microvascular dysfunction being recognized as a hallmark of the advanced stage. In this study, we demonstrated that exosomes collected from the vitreous humor of proliferative diabetic retinopathy patients promoted proliferation, migration and tube formation ability of primary human retinal endothelial cells via its elevated miR-9-3p expression level. Müller glia cells were further recognized as the sole source of the aberrantly expressed miR-9-3p, and both in vitro and in vivo experiments validated that Müller glia-derived exosomes aggravate vascular dysfunction under high glucose. Mechanistically, exosomal miRNA-9-3p was transferred to retinal endothelial cells and bound to the sphingosine-1-phosphate receptor S1P₁ coding sequence, which subsequently activated VEGFR2 phosphorylation and internalization in the presence or absence of exogenous VEGF-A. We successfully orchestrated the dynamic crosstalk between retinal Müller glia cells and endothelial cells in pathological condition, which may provide a novel biomarker or promising therapeutic agents for the treatment of diabetic retinopathy.

Recent Progress in Understanding the Action of Natural Compounds at Novel Therapeutic Drug Targets for the Treatment of Liver Cancer

Liver cancer is the third most common cause of cancer-related death following lung and stomach cancers. As a highly lethal disease, liver cancer is diagnosed frequently in less developed countries. Natural compounds extracted from herbs, animals and natural materials have been adopted by traditional Chinese medicine (TCM) practices and reported to be effective in the development of new medications for the treatment of diseases. It is important to focus on the mechanisms of action of natural compounds against hepatocellular carcinoma (HCC), particularly in terms of cell cycle regulation, apoptosis induction, autophagy mediation and cell migration and invasion. In this review, we characterize novel representative natural compounds according to their pharmacologic effects based on recently published studies. The aim of this review is to summarize and explore novel therapeutic drug targets of natural compounds, which could accelerate the discovery of new anticancer drugs.

Mitophagy alleviates ischemia/reperfusion-induced microvascular damage through improving mitochondrial quality control

The coronary arteries mainly function to perfuse the myocardium. When coronary artery resistance increases, myocardial perfusion decreases and myocardial remodeling occurs. Mitochondrial damage has been regarded as the primary cause of microvascular dysfunction. In the present study, we explored the effects of mitophagy activation on microvascular damage. Hypoxia/reoxygenation injury induced mitochondrial oxidative stress, thereby promoting mitochondrial dysfunction in endothelial cells. Mitochondrial impairment induced apoptosis, reducing the viability and proliferation of endothelial cells. However, supplementation with the mitophagy inducer urolithin A (UA) preserved mitochondrial function by reducing mitochondrial oxidative stress and stabilizing the mitochondrial membrane potential in endothelial cells. UA also sustained the viability and improved the proliferative capacity of endothelial cells by suppressing apoptotic factors and upregulating cyclins D and E. In addition, UA inhibited mitochondrial fission and restored mitochondrial fusion, which reduced the proportion of fragmented mitochondria within endothelial cells. UA enhanced mitochondrial biogenesis in endothelial cells by upregulating sirtuin 3 and peroxisome proliferator-activated receptor gamma coactivator 1-alpha. These results suggested that activation of mitophagy may reduce hypoxia/reoxygenation-induced cardiac microvascular damage by improving mitochondrial quality control and increasing cell viability and proliferation.

TMEM60 Promotes the Proliferation and Migration and Inhibits the Apoptosis of Glioma through Modulating AKT Signaling

Glioma is a highly fatal malignancy with aggressive proliferation, migration, and invasion metastasis due to aberrant genetic regulation. This work aimed to determine the function of transmembrane protein 60 (TMEM60) during glioma development. The level of TMEM60 in glioma tissues and normal tissues and its correlation with glioma prognosis were checked in The Cancer Genome Atlas (TCGA) database. The levels of TMEM60 in glioma cell lines and normal astrocytes were determined by quantitative real-time PCR and western blotting assay. TMEM60 knockdown and overexpression were conducted, followed by detection of cell viability, migration, invasion, and apoptosis. CCK-8 and colony formation assay were adopted to detect cell viability proliferation. Transwell assay was performed to measure cell migration and invasion. Cell apoptosis was evaluated by flow cytometry. The alternation of key proteins in the PI3K/Akt signaling pathway was measured by western blotting. TMEM60 expression was significantly higher in glioma tissues than that in the healthy control and was correlated with poor overall survival of patients. The protein and mRNA levels of TMEM60 were both elevated in glioma cell lines in comparison with the normal cell lines. Elevated level of TMEM60 led to enhanced proliferation, migration, and invasion and suppressed cell apoptosis. TMEM60 promoted the activation of PI3K/Akt signaling. Our data suggested that TMEM60 plays an oncogenic role in glioma progression via activating the PI3K/Akt signaling pathway.

BI-1 ameliorates myocardial injury by activating the mitochondrial unfolded protein response and FUNDC1-related mitophagy in cardiorenal syndrome type 3

It has been suggested that mitochondrial dysfunction underlies the myocardial injury seen following cardiorenal syndrome type 3 (CRS-3). Both mitophagy and the mitochondrial unfolded protein response (UPR^mt) are protective programs that preserve mitochondrial homeostasis. Here, we explored whether Bax inhibitor-1 (BI-1) overexpression attenuates CRS-3-related myocardial injury through activation of mitophagy and the UPR^mt in cardiomyocytes. Following CRS-3 induction via renal ischemia-reperfusion injury, BI-1 transgenic (BI1^TG) mice showed greater preservation of myocardial integrity and relaxation function and less cardiomyocyte apoptosis than wild-type (WT) mice. Moreover, BI-1 overexpression attenuated CRS-3-mediated myocardial inflammation, as indicated by decreased MCP-1 and IL-6 expression and normalized ATP production in cardiomyocytes. After CRS-3 induction, mitophagy was inhibited in cardiomyocytes from WT mice, as indicated by both decreased Fundc1 transcription and mt-Keima fluorescence, and modest activation of the UPR^mt, denoted by a slight increase in Atf6 mRNA levels. By contrast, activation of mitophagy and marked UPR^mt upregulation were observed in cardiac tissue from BI1^TG mice. shRNA-mediated silencing of Fundc1 or Atf6 greatly impaired mitochondrial metabolism and survival in cultured cardiomyocytes overexpressing BI-1. Thus, upregulation of BI-1 expression aimed at activating mitophagy and the UPR^mt may represent a useful therapeutic approach for the treatment of CRS-3.

Roles of Oxidative Stress and Raftlin in Wound Healing Under Negative-Pressure Wound Therapy

Background

Negative-pressure wound therapy (NPWT) is an effective way to promote wound healing. However, its mechanisms have not been investigated thoroughly. Growing evidence suggests that oxidative stress and Raftlin levels play important roles in wound healing. However, whether NPWT promotes wound healing through this mechanism remains unclear.

Purpose

Our study focuses on the different levels of oxidative stress and antioxidant response between wounds treated by NPWT and routine dressing change. The objective of this study was to measure the differences in Raftlin levels between the two groups, which is a new biomarker related to wound healing.

Methods

We divided 48 male Sprague-Dawley rats with identical full-thickness skin defects into two groups. At specific times (0, 3, 5, 7, 9, 11, and 13 days after surgery), wound tissue samples were obtained for immunohistochemistry and biochemical analysis. The expression of Raftlin and levels of oxidative stress, including malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) levels were measured by biochemical analysis. Wound-healing times were also compared.

Results

In the NPWT group, MDA levels were significantly decreased on days 3, 5, and 7. Furthermore, the expressions of SOD and CAT were significantly reduced on days 3 and 5. Our data also revealed that Raftlin was significantly upregulated across the whole period of wound healing. Moreover, wound healing in the NPWT group was significantly more rapid (16 days on average) than in the control group (24 days on average). On day 13 post surgery, the wound-healing percentage in the NPWT group was 91%, while that in the control group was 48%.

Conclusion

NPWT may promote wound healing by upregulating Raftlin and inhibiting oxidative stress levels.

Mst2 Overexpression Inhibits Thyroid Carcinoma Growth and Metastasis by Disrupting Mitochondrial Fitness and Endoplasmic Reticulum Homeostasis

Although the incidence of thyroid carcinoma has increased over the past several decades, it has an excellent prognosis and overall 5-year survival, with a stable mortality rate, except in cases with advanced stages or rare malignant tumor types. Biomarkers have emerged as effective targets of molecular therapy against thyroid carcinoma due to their rapid and convenient detection; however, there has been little clinical application. Macrophage stimulating 2 (Mst2) is a proapoptotic protein with implications in carcinogenesis and metastasis. We found that Mst2 overexpression-induced endoplasmic reticulum (ER) stress in MDA-T32 thyroid carcinoma cells, accompanied by elevated caspase-12 activity, increased apoptotic rate, and reduced cell viability. In addition, Mst2 overexpression contributed to mitochondrial damage, as evidenced by increased mitochondrial oxidative stress and activated the mitochondrial apoptotic pathway. Inhibition of the JNK pathway abolished these effects. These results show Mst2 to be a novel tumor suppressor that induces mitochondrial dysfunction and ER stress via the JNK pathway. Thus, Mst2 could potentially serve as a biomarker for developing targeted therapy against thyroid carcinoma.

MKP-1 Overexpression Reduces Postischemic Myocardial Damage through Attenuation of ER Stress and Mitochondrial Damage

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress contribute to postischemic myocardial damage, but the upstream regulatory mechanisms have not been identified. In this study, we analyzed the role of mitogen-activated protein kinase (MAPK) phosphatase 1 (MKP-1) in the regulation of mitochondrial function and ER stress in hypoxic cardiomyocytes. Our results show that MKP-1 overexpression sustains viability and reduces hypoxia-induced apoptosis among H9C2 cardiomyocytes. MKP-1 overexpression attenuates ER stress and expression of ER stress genes and improves mitochondrial function in hypoxia-treated H9C2 cells. MKP-1 overexpression also increases ATP production and mitochondrial respiration and attenuates mitochondrial oxidative damage in hypoxic cardiomyocytes. Moreover, our results demonstrate that ERK and JNK are the downstream signaling targets of MKP-1 and that MKP-1 overexpression activates ERK, while it inhibits JNK. Inhibition of ERK reduces the ability of MKP-1 to preserve mitochondrial function and ER homeostasis in hypoxic cardiomyocytes. These results show that MKP-1 plays an essential role in the regulation of mitochondrial function and ER stress in hypoxic H9C2 cardiomyocytes through normalization of the ERK pathway and suggest that MKP-1 may serve as a novel target for the treatment of postischemic myocardial injury.

Irisin Attenuates Oxidative Stress, Mitochondrial Dysfunction, and Apoptosis in the H9C2 Cellular Model of Septic Cardiomyopathy through Augmenting Fundc1-Dependent Mitophagy

In the present study, we used lipopolysaccharide- (LPS-) stimulated H9C2 cardiomyocytes to investigate whether irisin treatment attenuates septic cardiomyopathy via Fundc1-related mitophagy. Fundc1 levels and mitophagy were significantly reduced in LPS-stimulated H9C2 cardiomyocytes but were significantly increased by irisin treatment. Irisin significantly increased ATP production and the activities of mitochondrial complexes I and III in the LPS-stimulated cardiomyocytes. Irisin also improved glucose metabolism and significantly reduced LPS-induced levels of reactive oxygen species by increasing the activities of antioxidant enzymes, glutathione peroxidase (GPX), and superoxide dismutase (SOD), as well as levels of reduced glutathione (GSH). TUNEL assays showed that irisin significantly reduced LPS-stimulated cardiomyocyte apoptosis by suppressing the activation of caspase-3 and caspase-9. However, the beneficial effects of irisin on oxidative stress, mitochondrial metabolism, and viability of LPS-stimulated H9C2 cardiomyocytes were abolished by silencing Fundc1. These results demonstrate that irisin abrogates mitochondrial dysfunction, oxidative stress, and apoptosis through Fundc1-related mitophagy in LPS-stimulated H9C2 cardiomyocytes. This suggests irisin is a potentially useful treatment for septic cardiomyopathy, though further investigations are necessary to confirm our findings.

LATS2 Deletion Attenuates Myocardial Ischemia-Reperfusion Injury by Promoting Mitochondrial Biogenesis

Reperfusion therapy is the most effective treatment for acute myocardial infarction, but it can damage cardiomyocytes through a mechanism known as myocardial ischemia/reperfusion injury (MIRI). In this study, we investigated whether the large tumor suppressor kinase 2 (LATS2) contributes to the development of myocardial MIRI by disrupting mitochondrial biogenesis. Our in vitro data demonstrate that cardiomyocyte viability was reduced and apoptosis was increased in response to hypoxia/reoxygenation (H/R) injury. However, suppression of LATS2 by shRNA sustained cardiomyocyte viability by maintaining mitochondrial function. Compared to H/R-treated control cardiomyocytes, cardiomyocytes transfected with LATS2 shRNA exhibited increased mitochondrial respiration, improved mitochondrial ATP generation, and more stable mitochondrial membrane potential. LATS2 suppression increased cardiomyocyte viability and mitochondrial biogenesis in a manner dependent on PGC1α, a key regulator of mitochondrial metabolism. These results identify LATS2 as a new inducer of mitochondrial damage and myocardial MIRI and suggest that approaches targeting LATS2 or mitochondrial biogenesis may be beneficial in the clinical management of cardiac MIRI.

Protective Effect of Optic Atrophy 1 on Cardiomyocyte Oxidative Stress: Roles of Mitophagy, Mitochondrial Fission, and MAPK/ERK Signaling

Myocardial infarction is associated with oxidative stress and mitochondrial damage. However, the regulatory mechanisms underlying cardiomyocyte oxidative stress during myocardial infarction are not fully understood. In the present study, we explored the cardioprotective action of optic atrophy 1- (Opa1-) mediated mitochondrial autophagy (mitophagy) in oxidative stress-challenged cardiomyocytes, with a focus on mitochondrial homeostasis and the MAPK/ERK pathway. Our results demonstrated that overexpression of Opa1 in cultured rat H9C2 cardiomyocytes, a procedure that stimulates mitophagy, attenuates oxidative stress and increases cellular antioxidant capacity. Activation of Opa1-mediated mitophagy suppressed cardiomyocyte apoptosis by downregulating Bax, caspase-9, and caspase-12 and upregulating Bcl-2 and c-IAP. Using mitochondrial tracker staining and a reactive oxygen species indicator, our assays showed that Opa1-mediated mitophagy attenuated mitochondrial fission and reduced ROS production in cardiomyocytes. In addition, we found that inhibition of the MAPK/ERK pathway abolished the antioxidant action of Opa1-mediated mitophagy in these cells. Taken together, our data demonstrate that Opa1-mediated mitophagy protects cardiomyocytes against oxidative stress damage through inhibition of mitochondrial fission and activation of MAPK/ERK signaling. These findings reveal a critical role for Opa1 in the modulation of cardiomyocyte redox balance and suggest a potential target for the treatment of myocardial infarction.

Coronary microvascular injury in myocardial infarction: perception and knowledge for mitochondrial quality control

Endothelial cells (ECs) constitute the innermost layer in all blood vessels to maintain the structural integrity and microcirculation function for coronary microvasculature. Impaired endothelial function is demonstrated in various cardiovascular diseases including myocardial infarction (MI), which is featured by reduced myocardial blood flow as a result of epicardial coronary obstruction, thrombogenesis, and inflammation. In this context, understanding the cellular and molecular mechanisms governing the function of coronary ECs is essential for the early diagnosis and optimal treatment of MI. Although ECs contain relatively fewer mitochondria compared with cardiomyocytes, they function as key sensors of environmental and cellular stress, in the regulation of EC viability, structural integrity and function. Mitochondrial quality control (MQC) machineries respond to a broad array of stress stimuli to regulate fission, fusion, mitophagy and biogenesis in mitochondria. Impaired MQC is a cardinal feature of EC injury and dysfunction. Hence, medications modulating MQC mechanisms are considered as promising novel therapeutic options in MI. Here in this review, we provide updated insights into the key role of MQC mechanisms in coronary ECs and microvascular dysfunction in MI. We also discussed the option of MQC as a novel therapeutic target to delay, reverse or repair coronary microvascular damage in MI. Contemporary available MQC-targeted therapies with potential clinical benefits to alleviate coronary microvascular injury during MI are also summarized.

Novel Insight into the Role of Endoplasmic Reticulum Stress in the Pathogenesis of Myocardial Ischemia-Reperfusion Injury

Impaired function of the endoplasmic reticulum (ER) is followed by evolutionarily conserved cell stress responses, which are employed by cells, including cardiomyocytes, to maintain and/or restore ER homeostasis. ER stress activates the unfolded protein response (UPR) to degrade and remove abnormal proteins from the ER lumen. Although the UPR is an intracellular defense mechanism to sustain cardiomyocyte viability and heart function, excessive activation initiates ER-dependent cardiomyocyte apoptosis. Myocardial ischemia/reperfusion (I/R) injury is a pathological process occurring during or after revascularization of ischemic myocardium. Several molecular mechanisms contribute to the pathogenesis of cardiac I/R injury. Due to the dual protective/degradative effects of ER stress on cardiomyocyte viability and function, it is of interest to understand the basic concepts, regulatory signals, and molecular processes involved in ER stress following myocardial I/R injury. In this review, therefore, we present recent findings related to the novel components of ER stress activation. The complex effects of ER stress and whether they mitigate or exacerbate myocardial I/R injury are summarized to serve as the basis for research into potential therapies for cardioprotection through control of ER homeostasis.

Role of Active Components of Medicinal Food in the Regulation of Angiogenesis

Angiogenesis refers to the formation of new blood vessels from the endothelial cells of existing arteries, veins, and capillaries. Angiogenesis is involved in a variety of physiological and pathological processes, such as the formation of malignant and development of atherosclerosis and other diseases. In recent years, many studies have shown that the active components of food have a certain regulatory effect on angiogenesis and negligible clinical limitations. With the increasing attention being paid to medicine and food homology, exploring the effect of active food components on angiogenesis is of great significance. In this review, we discuss the source, composition, pharmacological activity, and mechanism of action of certain active components of medicinal foods in detail. These could help prevent angiogenesis-related complications or provide a basis for healthier dietary habits. This review can provide a theoretical basis for the research and development of highly efficient anti-angiogenic drugs with low toxicity.