Role of apoptosis repressor with caspase recruitment domain (ARC) in cell death and cardiovascular disease

Effect of caspase inhibitors on hemodynamics and inflammatory factors in ARDS model rats

To study the effects of caspase inhibitors on hemodynamics and inflammatory factors in acute respiratory distress syndrome (ARDS) model rats. Sixty healthy male Wistar rats were randomly divided into three groups, namely, the control group, ARDS group and ARDS + Caspase inhibitor group, with 20 rats in each group. The control group was intraperitoneally injected with 2 mL/kg saline, and the ARDS model group was established by intraperitoneally injecting 4 mg/kg Lipopolysaccharide (LPS), ARDS + Caspase inhibitor group was adminstered 20 mg/kg caspase inhibitor after intraperitoneal LPS injection. Changes in pulmonary arterial pressure (PAP) and mean arterial pressure (MAP) at 6 and 12 h before and after administration were recorded. Moreover, arterial blood gas was evaluated with a blood gas analyzer and changes in the partial pressure of O2 (PaO2), partial pressure of CO2 (PaCO2), partial pressure of O2/fraction of inspired O2 (PaO2/FiO2) were evaluated. In addition, the lung wet/dry weight (W/D) ratio and inflammatory factor levels in lung tissue were determined. Finally, pathological sections were used to determine the pulmonary artery media thickness (MT), MT percentage (MT%), and the degree of muscle vascularization. The pulmonary arterial pressure of rats was determined at several time points. Compared with the control group, the model group had a significantly increased pulmonary arterial pressure at each time point (P < 0.01), and the mean arterial pressure significantly increased at 6 h (P < 0.05). Compared with that of rats in the model group, the pulmonary arterial pressure of rats in drug administration group was significantly reduced at each time point after administration (P < 0.01), and the mean arterial pressure was significantly reduced at 6 h (P < 0.05). The arterial blood gas analysis showed that compared with those in the control group, PaO2, PaCO2 and PaO2/FiO2 in the model group were significantly reduced (P < 0.01), and PaO2, PaCO2 and PaO2/FiO2 were significantly increased after caspase inhibitor treatment (P < 0.05 or 0.01). The levels of the inflammatory mediators tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in the model group were significantly higher than those in the control group (P < 0.01), and they were significantly decreased after caspase inhibitor treatment (P < 0.01). In the model group, pulmonary artery MT, MT% and the degree of muscle vascularization were significantly increased (P < 0.05 or 0.01), and pulmonary artery MT and the degree of muscle vascularization were significantly reduced after caspase inhibitor treatment (P < 0.05 or 0.01). Apoptosis Repressor with a Caspase Recuitment Domain (ARC) can alleviate the occurrence and development of pulmonary hypertension (PH) by affecting hemodynamics and reducing inflammation.

How does caspases regulation play role in cell decisions? apoptosis and beyond

Caspases are a family of cysteine proteases, and the key factors behind the cellular events which occur during apoptosis and inflammation. However, increasing evidence shows the non-conventional pro-survival action of apoptotic caspases in crucial processes. These cellular events include cell proliferation, differentiation, and migration, which may appear in the form of metastasis, and chemotherapy resistance in cancerous situations. Therefore, there should be a precise and strict control of caspases activity, perhaps through maintaining the threshold below the required levels for apoptosis. Thus, understanding the regulators of caspase activities that render apoptotic caspases as non-apoptotic is of paramount importance both mechanistically and clinically. Furthermore, the functions of apoptotic caspases are affected by numerous post-translational modifications. In the present mini-review, we highlight the various mechanisms that directly impact caspases with respect to their anti- or non-apoptotic functions. In this regard, post-translational modifications (PTMs), isoforms, subcellular localization, transient activity, substrate availability, substrate selection, and interaction-mediated regulations are discussed.

Molecular mechanisms involved in therapeutic effects of natural compounds against cisplatin-induced cardiotoxicity: a review

Cisplatin is a widely used chemotherapeutic agent for the treatment of various cancers. However, the clinical use of cisplatin is limited by its cardiotoxic side effects. The primary mechanisms implicated in this cardiotoxicity include mitochondrial dysfunction, oxidative stress, inflammation, and apoptotic. Numerous natural compounds (NCs) have been introduced as promising protective factors against cisplatin-mediated cardiac damage. The current review summarized the potential of various NCs as cardioprotective agents at the molecular levels. These compounds exhibited potent antioxidant and anti-inflammatory effects by interaction with the PI3K/AKT, AMPK, Nrf2, NF-κB, and NLRP3/caspase-1/GSDMD pathways. Generally, the modulation of these signaling pathways by NCs represents a promising strategy for improving the therapeutic index of cisplatin by reducing its cardiac side effects.

Exploring the Efficacy Enhancement Mechanism of Qixue Shuangbu prescription after TCM processing for treating chronic heart failure by regulating ERK/Bcl-2/Bax/Caspases-3 signaling pathway

Qixue Shuangbu prescription (QSP) has been used for the treatment of chronic heart failure (CHF) with remarkable curative effect. Processed QSP (PQSP) could significantly improve the treatment of CHF after traditional Chinese medicine (TCM) processing. This study elucidated the underlying efficacy enhancement mechanism of QSP after TCM processing for treating CHF in vitro and in vivo. The injury of rat cardiomyoblast H9c2 cells was induced by anoxia/reoxygenation to mimic CHF state in vitro. Sixty Sprague-Dawley rats were used to established CHF model by intraperitoneally injecting doxorubicin (the accumulative dose 15 mg/kg). Biochemical examinations were performed in serum and cellular supernatant, respectively. Cardiac functions and histopathological changes were evaluated in CHF model rats. The protein and mRNA levels of ERK1/2, Bcl-2, Bax and Caspase-3 were evaluated by Western blot and RT-PCR, respectively. All above results of low dose crude QSP-treated group (L-CQSP), high dose CQSP-treated group (H-CQSP), low dose PQSP-treated group (L-PQSP), high dose PQSP-treated group (H-PQSP) were compared to systematically explore correlations between TCM processing and the efficacy enhancement for treating CHF of PQSP. Compared with the model group, the L-CQSP group showed significant improvement in cardiac function at 8th weeks, while no significant improvement in cardiomyocyte apoptosis and fibrosis. Both H-CQSP, L-PQSP and H-PQSP exerted beneficial therapeutic effects in injured H9c2 cardiomyocytes and CHF model rats. L-PQSP and H-PQSP significantly increased cell viability and the activity of SOD, decreased the activities of LDH, MDA and NO, up-regulated the expression of ERK1/2 and Bcl-2, down-regulated the expression of Bax and Caspase-3 compared to the same dosage of CQSP. The efficacy enhancement mechanism of PQSP after TCM processing for treating CHF was directly related to the regulation of ERK/Bcl-2/Bax/Caspases-3 signaling pathway.

Long-term administration of morphine specifically alters the level of protein expression in different brain regions and affects the redox state

We investigated the changes in redox state and protein expression in selected parts of the rat brain induced by a 4 week administration of morphine (10 mg/kg/day). We found a significant reduction in lipid peroxidation that mostly persisted for 1 week after morphine withdrawal. Morphine treatment led to a significant increase in complex II in the cerebral cortex (Crt), which was accompanied by increased protein carbonylation, in contrast to the other brain regions studied. Glutathione levels were altered differently in the different brain regions after morphine treatment. Using label-free quantitative proteomic analysis, we found some specific changes in protein expression profiles in the Crt, hippocampus, striatum, and cerebellum on the day after morphine withdrawal and 1 week later. A common feature was the upregulation of anti-apoptotic proteins and dysregulation of the extracellular matrix. Our results indicate that the tested protocol of morphine administration has no significant toxic effect on the rat brain. On the contrary, it led to a decrease in lipid peroxidation and activation of anti-apoptotic proteins. Furthermore, our data suggest that long-term treatment with morphine acts specifically on different brain regions and that a 1 week drug withdrawal is not sufficient to normalize cellular redox state and protein levels.

Cell death in atherosclerosis

A complex and evolutionary process that involves the buildup of lipids in the arterial wall and the invasion of inflammatory cells results in atherosclerosis. Cell death is a fundamental biological process that is essential to the growth and dynamic equilibrium of all living things. Serious cell damage can cause a number of metabolic processes to stop, cell structure to be destroyed, or other irreversible changes that result in cell death. It is important to note that studies have shown that the two types of programmed cell death, apoptosis and autophagy, influence the onset and progression of atherosclerosis by controlling these cells. This could serve as a foundation for the creation of fresh atherosclerosis prevention and treatment strategies. Therefore, in this review, we summarized the molecular mechanisms of cell death, including apoptosis, pyroptosis, autophagy, necroptosis, ferroptosis and necrosis, and discussed their effects on endothelial cells, vascular smooth muscle cells and macrophages in the process of atherosclerosis, so as to provide reference for the next step to reveal the mechanism of atherosclerosis.

14-3-3ε: a protein with complex physiology function but promising therapeutic potential in cancer

Over the past decade, the role of the 14-3-3 protein has received increasing interest. Seven subtypes of 14-3-3 proteins exhibit high homology; however, each subtype maintains its specificity. The 14-3-3ε protein is involved in various physiological processes, including signal transduction, cell proliferation, apoptosis, autophagy, cell cycle regulation, repolarization of cardiac action, cardiac development, intracellular electrolyte homeostasis, neurodevelopment, and innate immunity. It also plays a significant role in the development and progression of various diseases, such as cardiovascular diseases, inflammatory diseases, neurodegenerative disorders, and cancer. These immense and various involvements of 14-3-3ε in diverse processes makes it a promising target for drug development. Although extensive research has been conducted on 14-3-3 dimers, studies on 14-3-3 monomers are limited. This review aimed to provide an overview of recent reports on the molecular mechanisms involved in the regulation of binding partners by 14-3-3ε, focusing on issues that could help advance the frontiers of this field. Video Abstract.

Gut-derived 4-hydroxyphenylacetic acid attenuates sepsis-induced acute kidney injury by upregulating ARC to inhibit necroptosis

BACKGROUND

Studies have found that the plasma content of gut-derived 4-hydroxyphenylacetic acid (4-HPA) was significantly increased in septic patients. However, the mechanism of 4-HPA elevation during sepsis and its relationship with sepsis-induced acute kidney injury (SAKI) remain unclear.

METHODS

Cecal ligation and puncture (CLP) was performed in C57BL/6 mice to establish the SAKI animal model. Human renal tubular epithelial (HK-2) cells stimulated with lipopolysaccharide were used to establish the SAKI cell model. The widely targeted metabolomics was applied to analyze the renal metabolite changes after CLP. Proteomics was used to explore potential target proteins regulated by 4-HPA. The blood sample of clinical sepsis patients was collected to examine the 4-HPA content.

RESULTS

We found that renal gut-derived 4-HPA levels were significantly increased after CLP. The high permeability of intestinal barrier after sepsis contributed to the dramatic increase of renal 4-HPA. Intriguingly, we demonstrated that exogenous 4-HPA administration could further significantly reduce CLP-induced increases in serum creatinine, urea nitrogen, and cystatin C, inhibit renal pathological damage and apoptosis, and improve the survival of mice. Mechanistically, 4-HPA inhibited necroptosis in renal tubular epithelial cells by upregulating the protein expression of apoptosis repressor with caspase recruitment domain (ARC) and enhancing the interaction between ARC and receptor-interacting protein kinase 1 (RIPK1).

CONCLUSIONS

The increase of gut-derived 4-HPA in the kidney after sepsis could play a protective effect in SAKI by upregulating ARC to inhibit necroptosis.

Effect of miR-182-5p on apoptosis in myocardial infarction

Objective

This study aimed to delineate the diagnostic significance of miR-182-5p by investigating its influence on myocardial apoptosis and function, employing both in vivo and in vitro myocardial infarction models.

Methods

A rat myocardial infarction model was established. Myocardial infarction area was detected using the 2,3,5-chlorotriphenyltetrazolium (TTC) method, myocardial enzyme spectrums were measured using enzyme-linked immunosorbent assay (ELISA), myocardial structure was detected by hematoxylin and eosin (HE) staining, myocardial apoptosis was detected using the TUNEL method, and expression levels of miR-182-5p and apoptosis-related molecules were detected using real-time fluorescence quantitative PCR (qPCR) and Western blot. miR-182-5p mimics and inhibitor were transfected into rat H9C2 cardiomyocytes and mouse HL-1 cardiomyocytes to establish a hypoxia model. Cardiomyocyte viability was detected using the CCK-8 method, expression levels of apoptosis-related indicators were detected using Western blot, and caspase-3/7 activity was detected using a caspase-3/7 activity detection kit. AAV9 adeno-associated virus was used to construct an miR-182-5p overexpression virus, which was injected into mice through the tail vein to create a mouse myocardial infarction model. TTC, ELISA, HE staining, echocardiography, real-time fluorescence qPCR, and Western blot methods were used to detect the effects of AAV9-miR-182-5p on myocardial injury, myocardial function, and myocardial apoptosis levels in myocardial infarction.

Results

The rat model displayed reduced miR-182-5p expression concurrent with an increase in apoptosis. The in vitro H9C2 and HL-1 hypoxia models revealed that miR-182-5p augmented the hypoxia-induced decrease in myocardial cell viability, suppressed Bcl-2 expression, and increased Bax, Bnip3, and caspase-3/7 activity levels. The injection of AAV9-miR-182-5p significantly exacerbated myocardial tissue damage, impaired myocardial function, and enhanced apoptosis.

Conclusion

miR-182-5p escalates myocardial injury during myocardial infarction by fostering apoptosis. Interventions that aim to reduce miR-182-5p levels might be crucial in halting the progression of myocardial infarction.

Advances in the knowledge on the role of apoptosis repressor with caspase recruitment domain in hemorrhagic stroke

The apoptosis repressor with caspase recruitment domain (ARC) plays a critical role in extrinsic apoptosis initiation via death receptor ligands, physiological stress, infection response in a tissue-dependent manner, endoplasmic reticulum (ER) stress, genotoxic drugs, ionizing radiation, oxidative stress, and hypoxia. Recent studies have suggested that regulating apoptosis-related pathways can improve outcomes for patients with neurological diseases, such as hemorrhagic stroke. ARC expression is significantly correlated with acute cerebral hemorrhage. However, the mechanism by which it mediates the anti-apoptosis pathway remains poorly known. Here, we discuss the function of ARC in hemorrhagic stroke and argue that it could serve as an effective target for the treatment of hemorrhagic stroke.

Targeted delivery and apoptosis induction activity of peptide-transferrin targeted mesoporous silica encapsulated resveratrol in MCF-7 cells

OBJECTIVES

Resveratrol (Res) was a naturally occurring polyphenol compound. It has various beneficial effects, including anti-inflammatory, anti-oxidant and anti-cancer effects. However, the anti-cancer activity was hindered by its low targeting and drug release performance. Thus, we synthesized transferrin-cathepsin B cleavable peptide modified mesoporous silica nanoparticle encapsulated Res (Tf-Res-MSN).

METHODS

Res was encapsulated in mesoporous silica nanoparticles (MSN), which was a kind of drug carrier complex. Tf was modified to recognize the cancer cells. Cathepsin B cleavable peptide (Pep) was used to combine Res-MSN complex and Tf to construct the final product. Pep was used as linker and trigger for Res release.

KEY FINDINGS

The smart nanocarriers were increased the drug release performance of Res in human breast cancer (MCF-7) cells. The physicochemical properties of Tf-Res-MSN were assessed by zeta potential, UV-Prove, diffraction scanning calorimetry (DSC), nitrogen physisorption analysis and transmission electron microscope (TEM). MTT assay, AO and Annexin V-FITC/PI staining were performed to explore the anti-tumour activity of Tf-Res-MSN. The results showed that Tf-Res-MSN significantly decreased cell viability and increased cell apoptosis. The inhibition rate and apoptotic rate of Tf-Res-MSN in MCF-7 cells were 95.75% and 80.8%, respectively.

CONCLUSION

Our study demonstrated that Tf-Res-MSN was a valuable technique with potential value in breast cancer applications.

A double-edged sword: role of apoptosis repressor with caspase recruitment domain (ARC) in tumorigenesis and ischaemia/reperfusion (I/R) injury

Apoptosis repressor with caspase recruitment domain (ARC) acts as a potent and multifunctional inhibitor of apoptosis, which is mainly expressed in postmitotic cells, including cardiomyocytes. ARC is special for its N-terminal caspase recruitment domain and caspase recruitment domain. Due to the powerful inhibition of apoptosis, ARC is mainly reported to act as a cardioprotective factor during ischaemia‒reperfusion (I/R) injury, preventing cardiomyocytes from being devastated by various catastrophes, including oxidative stress, calcium overload, and mitochondrial dysfunction in the circulatory system. However, recent studies have found that ARC also plays a potential regulatory role in tumorigenesis especially in colorectal cancer and renal cell carcinomas, through multiple apoptosis-associated pathways, which remains to be explored in further studies. Therefore, ARC regulates the body and maintains the balance of physiological activities with its interesting duplex. This review summarizes the current research progress of ARC in the field of tumorigenesis and ischaemia/reperfusion injury, to provide overall research status and new possibilities for researchers.

Ferulic acid: An extraordinarily neuroprotective phenolic acid with anti-depressive properties

BACKGROUND

Depression, one of the most common mental illnesses and mood disorder syndromes, can seriously harm physical and mental health. As the pathophysiology of depression remains unclear, there is a need to find novel therapeutic agents. Ferulic acid (FA), a phenolic compound found in various Chinese herbal medicines, has anti-inflammatory and free radical scavenging properties as well as a wide range of therapeutic effects against depression.

PURPOSE

In this review, we appraised preclinical research to fully discuss the anti-depression capacity of FA and discussed FAs' holistic characteristics that can contribute to better management of depression.

STUDY DESIGN

We reviewed the results of in vitro and in vivo experiments using FA to treat depression and explored the possible antidepressant pharmacological mechanisms of FA for the clinical treatment of depression.

METHODS

Electronic databases, including PubMed, Google Scholar, and China National Knowledge Infrastructure, were searched from the beginning of the database creation to December 2021.

RESULTS

Studies on the antidepressant effects of FA show that it may exert such effects through various mechanisms. These include the following: the regulation of monoamine and non-monoamine neurotransmitter levels, inhibition of hypothalamic-pituitary-adrenal axis hyperfunction and neuroinflammation, promotion of hippocampal neurogenesis and upregulation brain-derived neurotrophic factor level, neuroprotection (inhibition of neuroinflammation, oxidative stress, mitochondrial dysfunction, and apoptosis), and downregulation of oxidative stress.

CONCLUSION

Preclinical studies on the antidepressant effects of FA were reviewed in this study, and research on the antidepressant mechanisms of FA was summarized, confirming that FA can exert antidepressant effects through various pharmacological mechanisms. However, more multicenter clinical case-control studies are needed to confirm the clinical efficacy of FA.

Embryonic stem cell-derived mesenchymal stem cells alleviate skeletal muscle injury induced by acute compartment syndrome

Background

Acute compartment syndrome (ACS), a well-known complication of musculoskeletal injury, results in muscle necrosis and cell death. Embryonic stem cell-derived mesenchymal stem cells (ESC-MSCs) have been shown to be a promising therapy for ACS. However, their effectiveness and potentially protective mechanism remain unknown. The present study was designed to investigate the efficacy and underlying mechanism of ESC-MSCs in ACS-induced skeletal muscle injury.

Method

A total of 168 male Sprague–Dawley (SD) rats underwent 2 h of intracompartmental pressure elevation by saline infusion into the anterior compartment of the left hindlimb to establish the ACS model. ESC-MSCs were differentiated from the human embryonic stem cell (ESC) line H9. A dose of 1.2 × 10⁶ of ESC-MSCs was intravenously injected during fasciotomy. Post-ACS assessments included skeletal edema index, serum indicators, histological analysis, apoptosis, fibrosis, regeneration, and functional recovery of skeletal muscle. Then, fluorescence microscopy was used to observe the distribution of labeled ESC-MSCs in vivo, and western blotting and immunofluorescence analyses were performed to examine macrophages infiltration in skeletal muscle. Finally, we used liposomal clodronate to deplete macrophages and reassess skeletal muscle injury in response to ESC-MSC therapy.

Result

ESC-MSCs significantly reduced systemic inflammatory responses, ACS-induced skeletal muscle edema, and cell apoptosis. In addition, ESC-MSCs inhibited skeletal muscle fibrosis and increased regeneration and functional recovery of skeletal muscle after ACS. The beneficial effects of ESC-MSCs on ACS-induced skeletal muscle injury were accompanied by a decrease in CD86-positive M1 macrophage polarization and an increase in CD206-positive M2 macrophage polarization. After depleting macrophages with liposomal clodronate, the beneficial effects of ESC-MSCs were attenuated.

Conclusion

Our findings suggest that embryonic stem cell-derived mesenchymal stem cells infusion could effectively alleviate ACS-induced skeletal muscle injury, in which the beneficial effects were related to the regulation of macrophages polarization.

Melatonin Inhibits OGD/R-Induced H9c2 Cardiomyocyte Pyroptosis via Regulation of MT2/miR-155/FOXO3a/ARC Axis

Emerging literature suggests that pyroptosis plays a critical role in ischemia/hypoxia (I/R) -induced myocardial injury. Melatonin has been implicated in attenuating I/R-induced injury of cardiomyocytes. Nevertheless, whether melatonin inhibits I/R-induced pyroptosis of cardiomyocytes and the underlying molecular mechanisms remain unexploited.H9c2 cardiomyocytes were cultured under oxygen-glucose deprivation/reperfusion (OGD/R) condition to establish a myocardial pyroptosis model in vitro. OGD/R-induced pyroptosis was evaluated by CCK-8 assay, IL-1β and IL-18 release, and western blotting. Luciferase reporter assay was utilized to validate the association between miR-155 and Forkhead box O3a (FOXO3a).Melatonin could inhibit OGD/R-induced pyroptosis of H9c2 cells and upregulation of FOXO3a contributed to the antipyroptotic effect of melatonin. Melatonin reduced miR-155 expression, which led to FOXO3a upregulation and inhibition of pyroptosis in OGD/R-exposed H9c2 cells. miR-155 inhibitor enhanced the antipyroptotic effect of melatonin in OGD/R-exposed H9c2 cells. Melatonin-induced downregulation of miR-155 and upregulation of FOXO3a were reversed by melatonin receptor 2 (MT2) siRNA. Melatonin treatment also led to an increased level of apoptosis repressor with caspase recruitment domain (ARC), which was inhibited by FOXO3a siRNA. Moreover, silencing ARC by siRNA significantly blocked the antipyroptotic actions of melatonin, whereas ARC overexpression enhanced the antipyroptotic actions of melatonin in OGD/R-exposed H9c2 cells.Our findings demonstrated that melatonin prevented OGD/R-induced pyroptosis via regulating the MT2/miR-155/FOXO3a/ARC axis in cardiomyocytes.