Colchicine Improves Survival, Left Ventricular Remodeling, and Chronic Cardiac Function After Acute Myocardial Infarction

Colchicine Prevents Cardiac Rupture in Mice with Myocardial Infarction by Inhibiting P53-Dependent Apoptosis

Cardiac rupture is a fatal complication following myocardial infarction (MI) and there are currently no effective pharmacological strategies for preventing this condition. In this study, we investigated the effect of colchicine on post-infarct cardiac rupture in mice and its underlying mechanisms.We induced MI in mice by permanently ligating the left anterior descending artery. Oral colchicine or vehicle was administered at a dose of 0.1 mg/kg/day from day 1 to day 7 after MI. Cultured neonatal cardiomyocytes and fibroblasts were exposed to normoxia or anoxia and treated with colchicine.Colchicine significantly improved the survival rate (colchicine, n = 46: 82.6% versus vehicle, n = 42: 61.9%, P < 0.05) at 1 week after MI. Histological analysis revealed colchicine significantly reduced the infarct size and the number of macrophages around the infarct area. Colchicine decreased apoptosis in the myocardium of the border zone and cultured cardiomyocytes and fibroblasts as assessed by TUNEL assay. Colchicine also attenuated the activation of p53 and decreased the expression of cleaved-caspase 3 and bax, as assessed by Western blotting.Colchicine prevents cardiac rupture via inhibition of apoptosis, which is attributable to the downregulation of p53 activity. Our findings suggest that colchicine may be a prospective preventive medicine for cardiac rupture, however, large clinical trials are required.

Postnatally overfed mice display cardiac function alteration following myocardial infarction

BACKGROUND

Cardiovascular (CV) pathologies remain a leading cause of death worldwide, often associated with common comorbidities such as overweight, obesity, type 2 diabetes or hypertension. An innovative mouse model of metabolic syndrome induced by postnatal overfeeding (PNOF) through litter size reduction after birth was developed experimentally. This study aimed to evaluate the impact of PNOF on cardiac remodelling and the development of heart failure following myocardial infarction.

METHODS

C57BL/6 male mice were raised in litter adjusted to 9 or 3 pups for normally-fed (NF) control and PNOF group respectively. After weaning, all mice had free access to standard diet and water. At 4 months, mice were subjected to myocardial infarction (MI). Echocardiographic follows-up were performed up to 6-months post-surgery and biomolecular analyses were carried-out after heart collection.

FINDINGS

At 4 months, PNOF mice exhibited a significant increase in body weight, along with a basal reduction in left ventricular ejection fraction (LVEF) and an increase in left ventricular end-systolic area (LVESA), compared to NF mice. Following MI, PNOF mice demonstrated a significant decrease in stroke volume and an increased heart rate compared to their respective initial values, as well as a notable reduction in cardiac output 4-months after MI. After 6-months, left ventricle and lung masses, fibrosis staining, and mRNA expression were all similar in the NF-MI and PNOF-MI groups.

INTERPRETATION

After MI, PNOF mice display signs of cardiac function worsening as evidenced by a decrease in cardiac output, which could indicate an early sign of heart failure decompensation.

The Effects of Colchicum Dispert and Bone Marrow-Derived Mesenchymal Stem Cell Therapy on Skeletal Muscle Injury in a Rat Aortic Ischemia-Reperfusion Model

BACKGROUND

Abdominal aortic aneurysms and peripheral artery disease pose significant health risks, ranking third after heart attacks and cerebral strokes. Surgical interventions often involve temporary aortic clamping, leading to ischemia-reperfusion injury and tissue damage. Colchicine and mesenchymal stem cells have shown promise, individually, in mitigating ischemia-reperfusion injury, but their combined effects remain understudied.

METHODS

This study utilized 42 male Wistar rats, divided into six groups: Control, Sham, Ischemia-Reperfusion, Colchicine, Mesenchymal stem cell, and Mix (colchicine and mesenchymal stem cell). The ischemia-reperfusion model involved clamping the abdominal aorta for 60 min, followed by 120 min of reperfusion. Colchicine and mesenchymal stem cell treatments were administered as pre- and post-ischemia interventions, respectively. Mesenchymal stem cells were cultured, characterized by flow cytometry, and verified for specific surface antigens. Blood and tissue samples were analyzed for oxidative stress markers, nitric oxide metabolites, and apoptosis using TUNEL.

RESULTS

There were significant differences between the groups in terms of the serum total antioxidant capacity (p < 0.001) and inflammation markers (ischemia-modified albumin, p = 0.020). The combined therapy group (Mix) exhibited the lowest inflammation levels. Arginine levels also showed significant variation (p = 0.028), confirming the ischemia-reperfusion injury model. In muscle tissues, the total antioxidant capacity (p = 0.022), symmetric dimethylarginine, and citrulline levels (p < 0.05) indicated nitric oxide metabolism. Apoptosis was notably high in the ischemia-reperfusion injury group as anticipated. It appeared to be reduced by colchicine, mesenchymal stem cells, and their combination, with the most significant decrease observed in the Mix group (p < 0.001).

CONCLUSIONS

This study highlights the potential of using combined colchicine and mesenchymal stem cell therapy to reduce muscle damage caused by ischemia-reperfusion injury. Further research is needed to understand the underlying mechanisms and confirm the clinical significance of this approach in treating extremity ischemia-reperfusion injuries.

Zebrafish as an innovative model for exploring cardiovascular disease induction mechanisms and novel therapeutic interventions: a molecular insight

Cardiovascular disease (CVD) is a common cardiac disorder that leads to heart attacks, strokes, and heart failure. It is primarily characterized by conditions that impact the heart and blood arteries, including peripheral artery disease, arrhythmias, atherosclerosis, myocardial ischemia, congenital heart abnormalities, heart failure, rheumatic heart disease, hypertension, and cardiomyopathies. These conditions are mainly effect the heart and blood vessels, causing blockages or weakened pumping, due to severe hereditary and environmental factors. The frequency of CVD is rising significantly as life expectancy increases. Despite this, no effective treatment or management for its symptoms has been found. One of the most difficult obstacles to overcome, is finding a suitable animal model for drug screening and drug development. Although rodents, mice, swine, and mammals serve as the basis for most animal models of cardiovascular disease, no model accurately captures the epidemiology of the condition. Zebrafish (Danio rerio) have drawn the interest of the international scientific community due to certain shortcomings of the previously discussed animal models because they are smaller, less costly, and have an incredibly high rate of reproduction. This review article emphasizes the significance of using zebrafish as an animal model to investigate the possible facets of cardiovascular disease. Moreover, the ultimate purpose of this review article is to establish the advantages of employing zebrafish over other animal models and to investigate the boundaries of using zebrafish to study human disease. Furthermore, the mechanisms of cardiovascular diseases induction in zebrafish were covered to improve understanding for readers. Finally, the analysis of cardiotoxicity using Zebra fish model, is also explained. In order to stop the health index from deteriorating, the current study also covers some innovative, effective, and relatively safer treatments for treatment and management of cardiotoxicity.

Studying the efficacy of low-dose colchicine on clinical outcomes of patients with STEMI: a randomized controlled trial

BACKGROUND

Numerous studies have underscored the essential role of inflammation across all stages of atherosclerosis. While various anti-inflammatory interventions have been implemented to mitigate inflammation-induced injuries, outcomes have been conflicting. Given the essential role of inflammation in these patients and limited data regarding the efficacy of low-dose Colchicine as an anti-inflammatory drug, we aimed to study the efficacy of low-dose Colchicine on clinical outcomes of patients with STEMI in Iran.

RESULTS

Participants presented with STEMI and qualified revascularization at Shahid Beheshti Hospital in Qom during 2022 and 2023 were included into the study. This study included 172 STEMI patients (114 males and 58 females) within the mean age of 58.93 ± 7.79. Results indicate that colchicine (2 mg for loading dose and 0.5 mg daily for 30 days) and placebo group were not significant differences in identical profiles regarding age and gender. Analyses revealed no significant differences in clinical outcome after the 40-day follow-up period.

CONCLUSIONS

This study revealed that the addition of colchicine did not yield a significant benefit in enhancing the outcomes of patients with STEMI.

CLINICAL TRIAL REGISTRATION

This study was prospectively registered on Iranian registry of clinical trials, with registration number (IRCT20231001059578N1).

Role of inflammation and evidence for the use of colchicine in patients with acute coronary syndrome

Acute Coronary Syndrome (ACS) significantly contributes to cardiovascular death worldwide. ACS may arise from the disruption of an atherosclerotic plaque, ultimately leading to acute ischemia and myocardial infarction. In the pathogenesis of atherosclerosis, inflammation assumes a pivotal role, not solely in the initiation and complications of atherosclerotic plaque formation, but also in the myocardial response to ischemic insult. Acute inflammatory processes, coupled with time to reperfusion, orchestrate ischemic and reperfusion injuries, dictating infarct magnitude and acute left ventricular (LV) remodeling. Conversely, chronic inflammation, alongside neurohumoral activation, governs persistent LV remodeling. The interplay between chronic LV remodeling and recurrent ischemic episodes delineates the progression of the disease toward heart failure and cardiovascular death. Colchicine exerts anti-inflammatory properties affecting both the myocardium and atherosclerotic plaque by modulating the activity of monocyte/macrophages, neutrophils, and platelets. This modulation can potentially result in a more favorable LV remodeling and forestalls the recurrence of ACS. This narrative review aims to delineate the role of inflammation across the different phases of ACS pathophysiology and describe the mechanistic underpinnings of colchicine, exploring its purported role in modulating each of these stages.

The role of pyroptosis in heart failure and related traditional chinese medicine treatments

Pyroptosis is a type of programmed cell death that is mediated by both typical and atypical pathways and ultimately leads to the lysis and rupture of cell membranes and the release of proinflammatory factors, triggering an intense inflammatory response. Heart failure (HF) is a serious and terminal stage of various heart diseases. Myocardial hypertrophy, myocardial fibrosis, ventricular remodeling, oxidative stress, the inflammatory response and cardiomyocyte ionic disorders caused by various cardiac diseases are all risk factors for and aggravate HF. Numerous studies have shown that pyroptosis can induce and exacerbate these reactions, causing progression to HF. Therefore, targeting pyroptosis is a promising strategy to treat HF. This paper summarizes the role of pyroptosis in the development of HF and the underlying mechanism involved. Recent research progress on the ability of traditional Chinese medicine (TCM) extracts and formulas to inhibit pyroptosis and treat HF was summarized, and some traditional Chinese medicine extracts and formulas can alleviate different types of HF, including heart failure with preserved ejection fraction (HFpEF), heart failure with reduced ejection fraction (HFrEF), and heart failure with midrange ejection fraction (HFmrEF), by targeting pyroptosis. These findings may provide new ideas and evidence for the treatment or adjuvant treatment of HF by targeting pyroptosis.

The Role of Inflammasomes in Heart Failure

Heart failure (HF) poses a significant world health challenge due to the increase in the aging population and advancements in cardiac care. In the pathophysiology of HF, the inflammasome has been correlated with the development, progression, and complications of HF disease. Discovering biomarkers linked to inflammasomes enhances understanding of HF diagnosis and prognosis. Directing inflammasome signaling emerges as an innovative therapeutic strategy for managing HF. The present review aims to delve into this inflammatory cascade, understanding its role in the development of HF, its potential role as biomarker, as well as the prospects of modulating inflammasomes as a therapeutic approach for HF.

Inflammation in heart failure: pathophysiology and therapeutic strategies

A role for inflammation in the development and progression of heart failure (HF) has been proposed for decades. Multiple studies have demonstrated the potential involvement of several groups of cytokines and chemokines in acute and chronic HF, though targeting these pathways in early therapeutic trials have produced mixed results. These studies served to highlight the complexity and nuances of how pro-inflammatory pathways contribute to the pathogenesis of HF. More recent investigations have highlighted how inflammation may play distinct roles based on HF syndrome phenotypes, findings that may guide the development of novel therapies. In this review, we propose a contemporary update on the role of inflammation mediated by the innate and adaptive immune systems with HF, highlighting differences that exist across the ejection fraction spectrum. This will specifically be looked at through the lens of established and novel biomarkers of inflammation. Subsequently, we review how improvements in inflammatory pathways may mediate clinical benefits of existing guideline-directed medical therapies for HF, as well as future therapies in the pipeline targeting HF and inflammation.

Update on the Role of Colchicine in Cardiovascular Disease

PURPOSE OF REVIEW

This review focuses on the use of colchicine to target inflammation to prevent cardiovascular events among those at-risk for or with established coronary artery disease.

RECENT FINDINGS

Colchicine is an anti-inflammatory drug that reduces cardiovascular events through its effect on the IL-1β/IL-6/CRP pathway, which promotes the progression and rupture of atherosclerotic plaques. Clinical trials have demonstrated that colchicine reduces cardiovascular events by 31% among those with chronic coronary disease, and by 23% among those with recent myocardial infarction. Its ability to dampen inflammation during an acute injury may broaden its scope of use in patients at risk for cardiovascular events after major non-cardiac surgery. Colchicine is an effective anti-inflammatory therapy in the prevention of acute coronary syndrome. Ongoing studies aim to assess when, and in whom, colchicine is most effective to prevent cardiovascular events in patients at-risk for or with established coronary artery disease.

The role of the NLRP3 inflammasome and pyroptosis in cardiovascular diseases

An intense, stereotyped inflammatory response occurs in response to ischaemic and non-ischaemic injury to the myocardium. The NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome is a finely regulated macromolecular protein complex that senses the injury and triggers and amplifies the inflammatory response by activation of caspase 1; cleavage of pro-inflammatory cytokines, such as pro-IL-1β and pro-IL-18, to their mature forms; and induction of inflammatory cell death (pyroptosis). Inhibitors of the NLRP3 inflammasome and blockers of IL-1β and IL-18 activity have been shown to reduce injury to the myocardium and pericardium, favour resolution of the inflammation and preserve cardiac function. In this Review, we discuss the components of the NLRP3 inflammasome and how it is formed and activated in various ischaemic and non-ischaemic cardiac pathologies (acute myocardial infarction, cardiac dysfunction and remodelling, atherothrombosis, myocarditis and pericarditis, cardiotoxicity and cardiac sarcoidosis). We also summarize current preclinical and clinical evidence from studies of agents that target the NLRP3 inflammasome and related cytokines.

Prognostic Significance of Soluble PD-L1 on Cardiovascular Outcomes in Patients with Coronary Artery Disease

AIMS

Programmed cell death-1 (PD-1) and its ligand (PD-L1) regulate T cells, leading to immunotolerance. We previously demonstrated that patients with coronary artery disease (CAD) had increased circulating levels of soluble PD-L1 (sPD-L1). However, the prognostic significance of sPD-L1 on cardiovascular outcomes is unknown. In the present study, we evaluated the association between sPD-L1 and cardiovascular events in patients with CAD.

METHODS

We prospectively measured sPD-L1 in patients with CAD admitted to Kumamoto University Hospital between December 2017 and January 2020 and observed their cardiovascular event rate. The primary outcome was a composite of death from non-cardiovascular causes, death from cardiovascular causes, non-fatal myocardial infarction, unstable angina pectoris, revascularization, hospitalization for heart failure, and ischemic stroke.

RESULTS

Finally, 627 patients were enrolled, and 35 patients were lost to follow-up. The median follow-up duration was 522 days. In total, 124 events were recorded. The Kaplan-Meier curve showed that the event rate was higher in the higher sPD-L1 group (median ≥ 136 pg/dL) than in the lower sPD-L1 group (25.0% vs. 16.9%; p=0.028, log-rank test). Univariate Cox proportional hazards analysis showed that high-sensitivity C-reactive protein, an estimated glomerular filtration rate of ＜60 mL/min/1.73m2, B-type natriuretic peptide, left ventricular ejection fraction, and sPD-L1 were significantly associated with cardiovascular events. Multivariable Cox proportional hazards analysis of factors that were significant in univariate analysis identified that sPD-L1 was significantly and independently associated with cardiovascular events (hazard ratio: 1.364, 95% confidence interval: 1.018-1.828, p=0.038).

CONCLUSIONS

Higher sPD-L1 levels were significantly associated with future cardiovascular events in patients with CAD.

Mesenchymal stromal cells for improvement of cardiac function following acute myocardial infarction: a matter of timing

Acute myocardial infarction (AMI) is the leading cause of cardiovascular death and remains the most common cause of heart failure. Reopening of the occluded artery, i.e., reperfusion, is the only way to save the myocardium. However, the expected benefits of reducing infarct size are disappointing due to the reperfusion paradox, which also induces specific cell death. These ischemia-reperfusion (I/R) lesions can account for up to 50% of final infarct size, a major determinant for both mortality and the risk of heart failure (morbidity). In this review, we provide a detailed description of the cell death and inflammation mechanisms as features of I/R injury and cardioprotective strategies such as ischemic postconditioning as well as their underlying mechanisms. Due to their biological properties, the use of mesenchymal stromal/stem cells (MSCs) has been considered a potential therapeutic approach in AMI. Despite promising results and evidence of safety in preclinical studies using MSCs, the effects reported in clinical trials are not conclusive and even inconsistent. These discrepancies were attributed to many parameters such as donor age, in vitro culture, and storage time as well as injection time window after AMI, which alter MSC therapeutic properties. In the context of AMI, future directions will be to generate MSCs with enhanced properties to limit cell death in myocardial tissue and thereby reduce infarct size and improve the healing phase to increase postinfarct myocardial performance.

Bone-marrow mononuclear cells and acellular human amniotic membrane improve global cardiac function without inhibition of the NLRP3 Inflammasome in a rat model of heart failure

Recent studies have suggested that therapies with stem cells and amniotic membrane can modulate the inflammation following an ischemic injury in the heart. This study evaluated the effects of bone-marrow mononuclear cells (BMMC) and acellular human amniotic membrane (AHAM) on cardiac function and NLRP3 complex in a rat model of heart failure.On the 30th day,the echocardiographic showed improvements on ejection fraction and decreased pathological ventricular remodeling on BMMC and AHAM groups.Oxidative stress analysis was similar between the three groups,and the NLRP3 inflammasome activity were not decreased with the therapeutic use of both BMMC and AHAM,in comparison to the control group.

Colchicine Inhibits NETs and Alleviates Cardiac Remodeling after Acute Myocardial Infarction

PURPOSE

Colchicine, a multipotent anti-inflammatory drug, has been reported to alleviate cardiac remodeling and improve cardiac function after acute myocardial infarction (AMI). However, the underlying mechanism remains incompletely understood. Because neutrophils extracellular traps (NETs) enhance inflammation and participate in myocardial ischemia injury, and colchicine can inhibit NETosis, we thus aimed to determine whether colchicine exerts cardioprotective effects on AMI via suppressing NETs.

METHODS

Adult C57BL/6 mice were subjected to permanent ligation of the left anterior descending coronary artery and treated with colchicine (0.1 mg/kg/day) or Cl-amidine (10 mg/kg/day) for 7 or 28 days after AMI. Cardiac function was evaluated by echocardiography, and NETs detected by immunofluorescence. ROS production was detected using 2',7'-dichlorodihydrofluorescein diacetates (DCFH-DA) fluorometry. Intracellular Ca2+ concentration was assessed by a fluorometric ratio technique.

RESULTS

We found that colchicine treatment significantly increased mice survival (89.8% in the colchicine group versus 67.9% in control, n = 32 per group; log-rank test, p < 0.05) and improved cardiac function at day 7 (left ventricular ejection fraction (LVEF): 28.0 ± 9.2% versus 12.6 ± 3.9%, n = 8 per group; p < 0.001) and at day 28 (LVEF: 26.2 ± 7.2% versus 14.8 ± 6.7%, n = 8 per group; p < 0.001) post-AMI. In addition, the administration of colchicine inhibited NETs formation and inflammation. Furthermore, colchicine inhibited NETs formation by reducing NOX2/ROS production and Ca2+ influx. Moreover, prevention of NETs formation with Cl-amidine significantly alleviated AMI-induced cardiac remodeling.

CONCLUSIONS

Colchicine inhibited NETs and cardiac inflammation, and alleviated cardiac remodeling after acute myocardial infarction.

Colchicine ameliorates myocardial injury induced by coronary microembolization through suppressing pyroptosis via the AMPK/SIRT1/NLRP3 signaling pathway

BACKGROUND

Coronary microembolization(CME)is a common complication in acute coronary syndrome and percutaneous coronary intervention, which is closely related to poor prognosis. Pyroptosis, as an inflammatory programmed cell death, has been found to be associated with CME-induced myocardial injury. Colchicine (COL) has potential benefits in coronary artery disease due to its anti-inflammatory effect. However, the role of colchicine in pyroptosis-related CME-induced cardiomyocyte injury is unclear. This study was carried out to explore the effects and mechanisms of colchicine on myocardial pyroptosis induced by CME.

METHODS

The CME animal model was constructed by injecting microspheres into the left ventricle with Sprague-Dawley rats, and colchicine (0.3 mg/kg) pretreatment seven days before and on the day of modeling or compound C(CC)co-treatment was given half an hour before modeling. The study was divided into 4 groups: Sham group, CME group, CME + COL group, and CME + COL + CC group (10 rats for each group). Cardiac function, serum myocardial injury markers, myocardial histopathology, and pyroptosis-related indicators were used to evaluate the effects of colchicine.

RESULTS

Colchicine pretreatment improved cardiac dysfunction and reduced myocardial injury induced by CME. The main manifestations were the improvement of left ventricular systolic function, the decrease of microinfarction area, and the decrease of mRNA and protein indexes related to pyroptosis. Mechanistically, colchicine increased the phosphorylation level of adenosine monophosphate-activated protein kinase (AMPK), promoted the expression of silent information regulation T1 (SIRT1), and inhibited the expression of NOD-like receptor pyrin containing 3 (NLRP3) to reduce myocardial pyroptosis. However, after CC co-treatment with COL, the effect of colchicine was partially reversed.

CONCLUSION

Colchicine improves CME-induced cardiac dysfunction and myocardial injury by inhibiting cardiomyocyte pyroptosis through the AMPK/SIRT1/NLRP3 signaling pathway.

Colchicine prevents oxidative stress-induced endothelial cell senescence via blocking NF-κB and MAPKs: implications in vascular diseases

BACKGROUND

Smoking, alcohol abuse, and hypertension are - among others, potential risk factors for cardiovascular diseases. These risk factors generate oxidative stress and cause oxidative stress-induced DNA damage, resulting in cellular senescence and senescence-associated secretory phenotype (SASP). The SASP factors in feed-forward response exacerbate inflammation and cause tissue remodeling, resulting in atherosclerotic plaque formation and rupture.

RESULTS

Colchicine inhibited ROS generation and mitigated oxidative stress-induced DNA damage. It dampened oxidative stress-induced endothelial cell senescence and improved the expression of DNA repair protein KU80 and aging marker Lamin B1. The drug attenuated the expression of senescence marker P21 at mRNA and protein levels. The pathway analysis showed that colchicine inhibited NF-κB and MAPKs pathways and subdued mTOR activation. Colchicine also attenuated mRNA expression of interleukin (IL)-1β, IL-6, IL-8, MCP-1, ICAM-1, and E-selectin. Furthermore, colchicine reduced the mRNA and protein expression of matrix metalloproteinase (MMP-2).

CONCLUSION

In summary, colchicine blocked oxidative stress-induced senescence and SASP by inhibiting the activation of NF-κB and MAPKs pathways.

Heart graft preservation technics and limits: an update and perspectives

Heart transplantation, the gold standard treatment for end-stage heart failure, is limited by heart graft shortage, justifying expansion of the donor pool. Currently, static cold storage (SCS) of hearts from donations after brainstem death remains the standard practice, but it is usually limited to 240 min. Prolonged cold ischemia and ischemia-reperfusion injury (IRI) have been recognized as major causes of post-transplant graft failure. Continuous ex situ perfusion is a new approach for donor organ management to expand the donor pool and/or increase the utilization rate. Continuous ex situ machine perfusion (MP) can satisfy the metabolic needs of the myocardium, minimizing irreversible ischemic cell damage and cell death. Several hypothermic or normothermic MP methods have been developed and studied, particularly in the preclinical setting, but whether MP is superior to SCS remains controversial. Other approaches seem to be interesting for extending the pool of heart graft donors, such as blocking the paths of apoptosis and necrosis, extracellular vesicle therapy, or donor heart-specific gene therapy. In this systematic review, we summarize the mechanisms involved in IRI during heart transplantation and existing targeting therapies. We also critically evaluate all available data on continuous ex situ perfusion devices for adult donor hearts, highlighting its therapeutic potential and current limitations and shortcomings.

Early long-term low-dosage colchicine and major adverse cardiovascular events in patients with acute myocardial infarction: a systematic review and meta-analysis

Background

Current evidence on the efficacy and safety of colchicine after acute myocardial infarction (AMI) remains controversial. This study aims to clarify early low-dose long-term colchicine's exact efficacy and safety in AMI patients via more studies.

Methods

We searched PubMed, Web of Science, Embase, and Cochrane Library databases for randomized controlled trials assessing the efficacy of colchicine on major adverse cardiovascular events (MACE) in recent AMI patients from inception to January 29, 2023, without any restriction. Additionally, we conducted subgroup analyses to assess the impact of early (≤3 days) long-term (≥1 year) low-dosage (0.5 mg/d) colchicine. Summary estimates were computed using Mantel-Haenszel and reported as risk ratios (RRs) or standard mean differences (SMDs), mean differences (MDs) with 95% confidence intervals (CIs). Sensitivity analyses were performed to explore the potential sources of heterogeneity. Review Manager software was used for the meta-analysis.

Results

Eight studies identified from 564 screened records were analyzed, with 5,872 patients after AMI. The length of follow-up varied from five days to 22.7 months, and 0.5-1.0 mg colchicine was administered daily. In summary, compared to the control group, colchicine reduced the occurrence of MACE (RR, 0.56; 95% CI, 0.48-0.67) with 2.99-fold gastrointestinal adverse events in patients with recent AMI. Moreover, the relation referred to a gradual decrease in the occurrence of MACE with a longer follow-up duration (≥1 year) and lower dosage (0.5 mg/d) without leading more gastrointestinal adverse events. Colchicine decreased the follow-up levels of C-reactive protein (CRP) (MD -0.66, 95% CI, -0.98- -0.35) and neutrophils (SMD -0.22, 95% CI, -0.39- -0.55) when the follow-up period was 30 days.

Conclusion

Early long-term low-dose colchicine decreases the risk of MACE via anti-inflammation without leading more gastrointestinal adverse events in patients with AMI.

The Role of Small Extracellular Vesicles Derived from Mesenchymal Stromal Cells on Myocardial Protection: a Review of Current Advances and Future Perspectives

Small extracellular vesicles (SEVs) secreted by mesenchymal stromal cells (MSCs) are considered one of the most promising biological therapies in recent years. The protective effect of MSCs-derived SEVs on myocardium is mainly related to their ability to deliver cargo, anti-inflammatory properties, promotion of angiogenesis, immunoregulation, and other factors. Herein, this review focuses on the biological properties, isolation methods, and functions of SEVs. Then, the roles and potential mechanisms of SEVs and engineered SEVs in myocardial protection are summarized. Finally, the current situation of clinical research on SEVs, the difficulties encountered, and the future fore-ground of SEVs are discussed. In conclusion, although there are some technical difficulties and conceptual contradictions in the research of SEVs, the unique biological functions of SEVs provide a new direction for the development of regenerative medicine. Further exploration is warranted to establish a solid experimental and theoretical basis for future clinical application of SEVs.

Albumin protects the ultrastructure of the endothelial glycocalyx of coronary arteries in myocardial ischemia-reperfusion injury in vivo

Myocardial ischemia-reperfusion (I/R) injury induces endothelial glycocalyx (GCX) degradation. Several candidate GCX-protective factors including albumin have been identified, few have been demonstrated in in vivo studies and most albumins used to date have been heterologous. Albumin is a carrier protein for sphingosine 1-phosphate (S1P), which has protective effects on the cardiovascular system. However, changes inhibited by albumin in the endothelial GCX structure in I/R in vivo via the S1P receptor has not been reported. In this study, we aimed to determine whether albumin prevents the shedding of endothelial GCX in response to I/R in vivo. Rats were divided into four groups: control (CON), I/R, I/R with albumin preload (I/R + ALB), and I/R + ALB with S1P receptor agonist fingolimod (I/R + ALB + FIN). FIN acts as an initial agonist of S1P receptor 1 and downregulates the receptor in an inhibitory manner. The CON and I/R groups received saline and I/R + ALB and I/R + ALB + FIN groups received albumin solution before left anterior descending coronary artery ligation. Our study used rat albumin. Shedding of endothelial GCX was evaluated in the myocardium by electron microscopy, and the concentration of serum syndecan-1 was measured. Thus, albumin administration maintained the structure of endothelial GCX and prevented shedding of endothelial GCX via the S1P receptor in myocardial I/R, and FIN annihilated the protective effect of albumin against I/R injury.

Progranulin (PGRN) as a regulator of inflammation and a critical factor in the immunopathogenesis of cardiovascular diseases

Immune dysregulation has been identified as a critical cause of the most common types of cardiovascular diseases (CVDs). Notably, the innate and adaptive immune responses under physiological conditions are typically regulated with high sensitivity to avoid the exacerbation of inflammation, but any dysregulation can probably be associated with CVDs. In this respect, progranulin (PGRN) serves as one of the main components of the regulation of inflammatory processes, which significantly contributes to the immunopathogenesis of such disorders. PGRN has been introduced among the secreted growth factors as one related to wound healing, inflammation, and human embryonic development, as well as a wide variety of autoimmune diseases. The relationship between the serum PGRN and TNF-α ratio with the spontaneous bacterial peritonitis constitute one of the independent predictors of these conditions. The full-length PGRN can thus effectively reduce the calcification of valve interstitial cells, and the granulin precursor (GRN), among the degradation products of PGRN, can be beneficial. Moreover, it was observed that, PGRN protects the heart against ischemia-reperfusion injury. Above all, PGRN also provides protection in the initial phase following myocardial ischemia-reperfusion injury. The protective impact of PGRN on this may be associated with the early activation of the PI3K/Akt signaling pathway. PGRN also acts as a protective factor in hyperhomocysteinemia, probably by down-regulating the wingless-related integration site Wnt/β-catenin signaling pathway. Many studies have further demonstrated that SARS-CoV-2 (COVID-19) has dramatically increased the risks of CVDs due to inflammation, so PGRN has drawn much more attention among scholars. Lysosomes play a pivotal role in the inflammation process, and PGRN is one of the key regulators in their functioning, which contributes to the immunomodulatory mechanism in the pathogenesis of CVDs. Therefore, investigation of PGRN actions can help find new prospects in the treatment of CVDs. This review aims to summarize the role of PGRN in the immunopathogenesis of CVD, with an emphasis on its treatment.

Colchicine Does Not Reduce Abdominal Aortic Aneurysm Growth in a Mouse Model

Background and Aims

The nacht domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome is upregulated in human abdominal aortic aneurysm (AAA), but its pathogenic role is unclear. The aims of this study were firstly to examine whether the inflammasome was upregulated in a mouse model of AAA and secondly to test whether the inflammasome inhibitor colchicine limited AAA growth.

Methods

AAA was induced in eight-week-old male C57BL6/J mice with topical application of elastase to the infrarenal aorta and oral 3-aminopropionitrile (E-BAPN). For aim one, inflammasome activation, abdominal aortic diameter, and rupture were compared between mice with AAA and sham controls. For aim two, 3 weeks after AAA induction, mice were randomly allocated to receive colchicine (n = 28, 0.2 mg/kg/d) or vehicle control (n = 29). The primary outcome was the rate of maximum aortic diameter increase measured by ultrasound over 13 weeks.

Results

There was upregulation of NLRP3 markers interleukin- (IL-) 1β (median, IQR; 15.67, 7.11-22.60 pg/mg protein versus 6.87, 4.54-11.60 pg/mg protein, p = .048) and caspase-1 (109, 83-155 relative luminosity units (RLU) versus 45, 38-65 RLU, p < .001) in AAA samples compared to controls. Aortic diameter increase over 80 days (mean difference, MD, 4.3 mm, 95% CI 3.3, 5.3, p < .001) was significantly greater in mice in which aneurysms were induced compared to sham controls. Colchicine did not significantly limit aortic diameter increase over 80 days (MD -0.1 mm, 95% CI -1.1, 0.86, p = .922).

Conclusions

The inflammasome was activated in this mouse model of AAA; however, daily oral administration of colchicine did not limit AAA growth.

Effect of different doses of colchicine on high sensitivity C-reactive protein in patients with acute minor stroke or transient ischemic attack: A pilot randomized controlled trial

BACKGROUND AND PURPOSE

Patients with elevated levels of high-sensitivity C-reactive protein (hsCRP) are at increased risk of recurrent stroke. Colchicine is a unique anti-inflammatory medication that has shown promise in reducing cardiovascular event. The current study mainly tested the ability of colchicine at different doses to reduce hsCRP levels after stroke.

METHODS

This was a randomized controlled and open label trial. Eligible patients with acute minor ischemic stroke or transient ischemic attack (TIA) were randomized within 24 hours after symptom onset in a 1:1:1:1 ratio to four groups with different doses of colchicine. Group 1: 0.5 mg of colchicine per day for 14 days; groups 2: starting with 1mg of colchicine on days 1 through 7, and maintaining with 0.5 mg per day on days 8 through 14; group 3 and 4: respectively 2 mg and 3 mg of colchicine on day 1, following with 1mg per day on days 2 through 7 and continuing with 0.5 mg per day on days 8 through 14. Blood specimens were collected at randomization, 24 hours, 72 hours, 7 days and 14 days after index event for hsCRP measurements. The primary outcome was the change of hsCRP levels between baseline and 14 days.

RESULTS

A total of 39 patients were enrolled. Patients in group 2 had reduced level of hsCRP at 14-day compared with baseline value (p=0.005). Time-course analyses showed that patients in groups of 1 and 2 had lower hsCRP level at 7-day than that at baseline, and patients in groups of 1, 2 and 3 had lower ratios of hsCRP levels at 72 hours to those at baseline. Low dose of colchicine was well tolerated without discontinuation of drug.

CONCLUSION

Early treatment with low dose of colchicine reduced hsCRP levels in the patients with acute minor ischemic stroke and TIA.

Left Ventricular Remodeling after Myocardial Infarction: From Physiopathology to Treatment

Myocardial infarction (MI) is the leading cause of death and morbidity worldwide, with an incidence relatively high in developed countries and rapidly growing in developing countries. The most common cause of MI is the rupture of an atherosclerotic plaque with subsequent thrombotic occlusion in the coronary circulation. This causes cardiomyocyte death and myocardial necrosis, with subsequent inflammation and fibrosis. Current therapies aim to restore coronary flow by thrombus dissolution with pharmaceutical treatment and/or intravascular stent implantation and to counteract neurohormonal activation. Despite these therapies, the injury caused by myocardial ischemia leads to left ventricular remodeling; this process involves changes in cardiac geometry, dimension and function and eventually progression to heart failure (HF). This review describes the pathophysiological mechanism that leads to cardiac remodeling and the therapeutic strategies with a role in slowing the progression of remodeling and improving cardiac structure and function.

The NLRP3 Inflammasome as a Novel Therapeutic Target for Cardiac Fibrosis

Cardiac fibrosis often has adverse cardiovascular effects, including heart failure, sudden death, and malignant arrhythmias. However, there is no targeted therapy for cardiac fibrosis. Inflammation is known to play a crucial role in the disorder, and the NLR pyrin domain-containing-3 (NLRP3) inflammasome is closely associated with innate immunity. Therefore, further understanding the pathophysiological role of the inflammasome in cardiac fibrosis may provide novel strategies for the prevention and treatment of the disorder. The aim of this review was to summarize the present knowledge of NLRP3 inflammasome-related mechanisms underlying cardiac fibrosis and to suggest potential targeted therapy that could be used to treat the condition.

Colchicine Impacts Leukocyte Trafficking in Atherosclerosis and Reduces Vascular Inflammation

Background

Inflammation strongly contributes to atherosclerosis initiation and progression. Consequently, recent clinical trials pharmacologically targeted vascular inflammation to decrease the incidence of atherosclerosis-related complications. Colchicine, a microtubule inhibitor with anti-inflammatory properties, reduced cardiovascular events in patients with recent acute coronary syndrome and chronic coronary disease. However, the biological basis of these observations remains elusive. We sought to explore the mechanism by which colchicine beneficially alters the course of atherosclerosis.

Methods and Results

In mice with early atherosclerosis (Apoe-/- mice on a high cholesterol diet for 8 weeks), we found that colchicine treatment (0.25 mg/kg bodyweight once daily over four weeks) reduced numbers of neutrophils, inflammatory monocytes and macrophages inside atherosclerotic aortas using flow cytometry and immunohistochemistry. Consequently, colchicine treatment resulted in a less inflammatory plaque composition and reduced plaque size. We next investigated how colchicine prevented plaque leukocyte expansion and found that colchicine treatment mitigated recruitment of blood neutrophils and inflammatory monocytes to plaques as revealed by adoptive transfer experiments. Causally, we found that colchicine reduced levels of both leukocyte adhesion molecules and receptors for leukocyte chemoattractants on blood neutrophils and monocytes. Further experiments showed that colchicine treatment reduced vascular inflammation also in post-myocardial infarction accelerated atherosclerosis through similar mechanisms as documented in early atherosclerosis. When we examined whether colchicine also decreased numbers of macrophages inside atherosclerotic plaques by impacting monocyte/macrophage transitioning or in-situ proliferation of macrophages, we report that colchicine treatment did not influence macrophage precursor differentiation or macrophage proliferation using cell culture experiments with bone marrow derived macrophages.

Conclusions

Our data reveal that colchicine prevents expansion of plaque inflammatory leukocytes through lowering recruitment of blood myeloid cells to plaques. These data provide novel mechanistic clues on the beneficial effects of colchicine in the treatment of atherosclerosis and may inform future anti-inflammatory interventions in patients at risk.

The Role of Colchicine in Atherosclerosis: From Bench to Bedside

Inflammation is a key feature of atherosclerosis. The inflammatory process is involved in all stages of disease progression, from the early formation of plaque to its instability and disruption, leading to clinical events. This strongly suggests that the use of anti-inflammatory agents might improve both atherosclerosis progression and cardiovascular outcomes. Colchicine, an alkaloid derived from the flower Colchicum autumnale, has been used for years in the treatment of inflammatory pathologies, including Gout, Mediterranean Fever, and Pericarditis. Colchicine is known to act over microtubules, inducing depolymerization, and over the NLRP3 inflammasome, which might explain its known anti-inflammatory properties. Recent evidence has shown the therapeutic potential of colchicine in the management of atherosclerosis and its complications, with limited adverse effects. In this review, we summarize the current knowledge regarding colchicine mechanisms of action and pharmacokinetics, as well as the available evidence on the use of colchicine for the treatment of coronary artery disease, covering basic, translational, and clinical studies.

Colchicine prevents ventricular arrhythmias vulnerability in diet-induced obesity rats

AIMS

This study aimed to assess the role of colchicine in ventricular arrhythmias (VAs) induced by high fat diet (HFD)-fed rats.

METHODS AND RESULTS

Male rats were divided into four groups: CTL, normal diet plus saline; CTC, normal diet plus colchicine; HFD, HFD plus saline; HFC: HFD plus colchicine. Metabolic parameters, ECG parameters, ventricular electrophysiological parameters, ventricular histology, Western blot and RT-qPCR were measured. Compared with the HFD group, colchicine treatment significantly improved metabolic parameters, reduced ventricular fibrosis, increased the expression of Cav1.2, Kv4.2, Nav1.5, and Cx43, reduced CaMKII, p-CaMKII, p-RyR2 (S2808), and p-RyR2 (S2814) expression in LV. Furthermore, colchicine inhibited the inflammatory responses, prolonged ventricular effective refractory period (ERP), reduced corrected QT interval (QTc) and Tpeak-Tend interval, so as to reduce the susceptibility to VAs in obesity rats.

CONCLUSIONS

Colchicine could mitigate ventricular fibrosis, ventricular electrical remodeling, as well as the expression of ion channels, and inhibit obesity-induced inflammatory responses, which provides a new idea for colchicine to prevent VAs in obese individuals.

Colchicine for Coronary Artery Disease: A Review

Coronary artery disease is a serious threat to human health. More and more evidences indicate chronic inflammatory plays a key role in the development of this disease. Inflammation markers are gradually used in the diagnosis and treatment. Although the treatment of coronary heart disease with colchicine is still controversial, more and more studies showed that patients can benefit from this medicine. In this review, we discuss and summarize colchicine on essential pharmacology, anti-inflammatory mechanism of action, and the most important and recent clinical studies. According to these literatures, colchicine possibly will possibly become a new valuable and cheap medicine for the treatment of coronary artery disease.

The microtubule cytoskeleton in cardiac mechanics and heart failure

The microtubule network of cardiac muscle cells has unique architectural and biophysical features to accommodate the demands of the working heart. Advances in live-cell imaging and in deciphering the 'tubulin code' have shone new light on this cytoskeletal network and its role in heart failure. Microtubule-based transport orchestrates the growth and maintenance of the contractile apparatus through spatiotemporal control of translation, while also organizing the specialized membrane systems required for excitation-contraction coupling. To withstand the high mechanical loads of the working heart, microtubules are post-translationally modified and physically reinforced. In response to stress to the myocardium, the microtubule network remodels, typically through densification, post-translational modification and stabilization. Under these conditions, physically reinforced microtubules resist the motion of the cardiomyocyte and increase myocardial stiffness. Accordingly, modified microtubules have emerged as a therapeutic target for reducing stiffness in heart failure. In this Review, we discuss the latest evidence on the contribution of microtubules to cardiac mechanics, the drivers of microtubule network remodelling in cardiac pathologies and the therapeutic potential of targeting cardiac microtubules in acquired heart diseases.

NLRP3 Inflammasome Activation: A Therapeutic Target for Cerebral Ischemia–Reperfusion Injury

Millions of patients are suffering from ischemic stroke, it is urgent to figure out the pathogenesis of cerebral ischemia–reperfusion (I/R) injury in order to find an effective cure. After I/R injury, pro-inflammatory cytokines especially interleukin-1β (IL-1β) upregulates in ischemic brain cells, such as microglia and neuron. To ameliorate the inflammation after cerebral I/R injury, nucleotide-binding oligomerization domain (NOD), leucine-rich repeat (LRR), and pyrin domain-containing protein 3 (NLRP3) inflammasome is well-investigated. NLRP3 inflammasomes are complicated protein complexes that are activated by endogenous and exogenous danger signals to participate in the inflammatory response. The assembly and activation of the NLRP3 inflammasome lead to the caspase-1-dependent release of pro-inflammatory cytokines, such as interleukin (IL)-1β and IL-18. Furthermore, pyroptosis is a pro-inflammatory cell death that occurs in a dependent manner on NLRP3 inflammasomes after cerebral I/R injury. In this review, we summarized the assembly and activation of NLRP3 inflammasome; moreover, we also concluded the pivotal role of NLRP3 inflammasome and inhibitors, targeting the NLRP3 inflammasome in cerebral I/R injury.

Emerging Roles of Inflammasomes in Cardiovascular Diseases

Cardiovascular diseases are known as the leading cause of morbidity and mortality worldwide. As an innate immune signaling complex, inflammasomes can be activated by various cardiovascular risk factors and regulate the activation of caspase-1 and the production and secretion of proinflammatory cytokines such as IL-1β and IL-18. Accumulating evidence supports that inflammasomes play a pivotal role in the progression of atherosclerosis, myocardial infarction, and heart failure. The best-known inflammasomes are NLRP1, NLRP3, NLRC4, and AIM2 inflammasomes, among which NLRP3 inflammasome is the most widely studied in the immune response and disease development. This review focuses on the activation and regulation mechanism of inflammasomes, the role of inflammasomes in cardiovascular diseases, and the research progress of targeting NLRP3 inflammasome and IL-1β for related disease intervention.

Colchicine prevents disease progression in viral myocarditis via modulating the NLRP3 inflammasome in the cardiosplenic axis

Aim

The acute phase of a coxsackievirus 3 (CVB3)‐induced myocarditis involves direct toxic cardiac effects and the systemic activation of the immune system, including the cardiosplenic axis. Consequently, the nucleotide‐binding oligomerization domain‐like receptor pyrin domain‐containing‐3 (NLRP3) inflammasome pathway is activated, which plays a role in disease pathogenesis and progression. The anti‐inflammatory drug colchicine exerts its effects, in part, via reducing NLRP3 activity, and has been shown to improve several cardiac diseases, including acute coronary syndrome and pericarditis. The aim of the present study was to evaluate the potential of colchicine to improve experimental CVB3‐induced myocarditis.

Methods and results

C57BL6/j mice were intraperitoneally injected with 1 × 10⁵ plaque forming units of CVB3. After 24 h, mice were treated with colchicine (5 μmol/kg body weight) or phosphate‐buffered saline (PBS) via oral gavage (p.o.). Seven days post infection, cardiac function was haemodynamically characterized via conductance catheter measurements. Blood, the left ventricle (LV) and spleen were harvested for subsequent analyses. In vitro experiments on LV‐derived fibroblasts (FB) and HL‐1 cells were performed to further evaluate the anti‐(fibro)inflammatory and anti‐apoptotic effects of colchicine via gene expression analysis, Sirius Red assay, and flow cytometry. CVB3 + colchicine mice displayed improved LV function compared with CVB3 + PBS mice, paralleled by a 4.7‐fold (P < 0.01) and 1.7‐fold (P < 0.001) reduction in LV CVB3 gene expression and cardiac troponin‐I levels in the serum, respectively. Evaluation of components of the NLRP3 inflammasome revealed an increased percentage of apoptosis‐associated speck‐like protein containing a CARD domain (ASC)‐expressing, caspase‐1‐expressing, and interleukin‐1β‐expressing cells in the myocardium and in the spleen of CVB3 + PBS vs. control mice, which was reduced in CVB3 + colchicine compared with CVB3 + PBS mice. This was accompanied by 1.4‐fold (P < 0.0001), 1.7‐fold (P < 0.0001), and 1.7‐fold (P < 0.0001) lower numbers of cardiac dendritic cells, natural killer cells, and macrophages, respectively, in CVB3 + colchicine compared with CVB3 + PBS mice. A 1.9‐fold (P < 0.05) and 4.6‐fold (P < 0.001) reduced cardiac gene expression of the fibrotic markers, Col1a1 and lysyl oxidase, respectively, was detected in CVB3 + colchicine mice compared with CVB3 + PBS animals, and reflected by a 2.2‐fold (P < 0.05) decreased Collagen I/III protein ratio. Colchicine further reduced Col3a1 mRNA and collagen protein expression in CVB3‐infected FB and lowered apoptosis and viral progeny release in CVB3‐infected HL‐1 cells. In both CVB3 FB and HL‐1 cells, colchicine down‐regulated the NLRP3 inflammasome‐related components ASC, caspase‐1, and IL‐1β.

Conclusions

Colchicine improves LV function in CVB3‐induced myocarditis, involving a decrease in cardiac and splenic NLRP3 inflammasome activity, without exacerbation of CVB3 load.

Effects of Colchicine in a Rat Model of Diet-Induced Hyperlipidemia

Inflammation and hyperlipidemia play an essential role in the pathophysiology of endothelial dysfunction as well as atherosclerotic plaque formation, progression and rupture. Colchicine has direct anti-inflammatory effects by inhibiting multiple inflammatory signaling pathways. The purpose of our study was to evaluate colchicine activity in an animal model of hyperlipidemia induced by diet. A total of 24 male rats (wild type, WT) were divided into three groups: group one fed with a basic diet (BD) (WT + BD, n = 8), group two fed with a high-fat diet (HFD) (WT + HFD, n = 8)), and group three which received HFD plus drug treatment (colchicine, 0.5 mg/kg, i.p., daily administration). Total cholesterol, LDL-, HDL-cholesterol and triglycerides were determined. In addition, plasma transaminases, inflammation of oxidative stress markers, were measured. Tissue samples were evaluated using hematoxylin-eosin and red oil stain. At the end of the study, rats presented increased serum lipid levels, high oxidative stress and pro-inflammatory markers. The aortic histopathological section revealed that HFD induced signs of endothelial dysfunction. Colchicine treatment significantly resolved and normalized these alterations. Moreover, colchicine did not influence NAFLD activity score but significantly increased ALT and AST levels, suggesting that colchicine amplified the hepatocellular injury produced by the diet. Colchicine reduces plasma lipid levels, oxidative stress and inflammation markers and leads to more favorable histopathologic vascular and cardiac results. However, the adverse effects of colchicine could represent an obstacle to its safe use.

Role of NLRP3 Inflammasome in Myocardial Ischemia-Reperfusion Injury and Ventricular Remodeling

Reperfusion therapy is the optimal therapy for acute myocardial infarction (AMI), but acute inflammatory injury and chronic heart failure (HF) after myocardial ischemia and reperfusion (MI/R) remain the leading cause of death after AMI. Pyroptosis, a newly discovered form of cell death, has been proven to play a significant role in the acute reperfusion process and the subsequent chronic process of ventricular remodeling. Current research shows that multiple stimuli activate the pyroptotic signaling pathway and contribute to cell death and nonbacterial inflammation after MI/R. These stimuli promote the assembly of the nucleotide-binding and oligomerization-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome by activating NLRP3. The mature NLRP3 inflammasome cleaves procaspase-1 to active caspase-1, which leads to mature processing of interleukin (IL)-18, IL-1β, and gasdermin D (GSDMD) protein. That eventually results in cell lysis and generation of nonbacterial inflammation. The present review summarizes the mechanism of NLRP3 inflammasome activation after MI/R and discusses the role that NLRP3-mediated pyroptosis plays in the pathophysiology of MI/R injury and ventricular remodeling. We also discuss potential mechanisms and targeted therapy for which there is evidence supporting treatment of ischemic heart disease.

Combination of Colchicine and Ticagrelor Inhibits Carrageenan-Induced Thrombi in Mice

The formation of a thrombus is closely related to oxidative stress and inflammation. Colchicine is one of the most commonly prescribed medication for gout treatment, with anti-inflammation and antioxidative stress properties. Therefore, we speculated that it is possible for colchicine to treat thrombosis. In this study, we used carrageenan to induce thrombosis in BALB/c mice and fed mice with colchicine, ticagrelor, and their combination, respectively. We found colchicine inhibited carrageenan-induced thrombi in mouse tail, and the inhibition was enhanced by ticagrelor. In vitro, colchicine inhibited thrombin-induced retraction of human platelet clots. Mechanically, colchicine inhibited platelet activation by reducing the expression of platelet receptors, protease-activated receptor 4 (PAR4) and CD36, and inactivating of AKT and ERK1/2 pathways. Furthermore, in human umbilical vein endothelial cells (HUVECs), colchicine showed antioxidative stress effects through increasing protein expression of glutathione peroxidase-1 (GPx-1), and mRNA levels of forkhead box O3 (FOXO3a) and superoxide dismutase 2 (SOD2). In RAW264.7 cells, colchicine reduced LPS-enhanced inflammatory response through attenuating toll-like receptor 4 (TLR4) activation. In addition, colchicine reduced LPS or ox-LDL-induced monocyte adhesion to HUVECs by inhibiting intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) levels. Taken together, our study demonstrates that colchicine exerts antithrombotic function by attenuating platelet activation and inhibiting oxidative stress and inflammation. We also provide a potential new strategy for clinical treatment.

A Meta-Analysis Evaluating the Colchicine Therapy in Patients With Coronary Artery Disease

Background: Evidence from recent studies has shown the benefits of colchicine for patients with coronary artery disease. The aim was to assess the effect of colchicine treatment on cardiovascular events, with an estimation of the risk of discontinuation and net clinical benefit.

Methods and Results: Fourteen trials with a total of 13,186 patients were selected through a systematic search. Colchicine therapy significantly reduced the relative risk of primary endpoint by about 30% [RR 0.70 (95%CI:0.56–0.88)]. Compared with placebo, colchicine significantly reduced the risk of ischemia-driven revascularization [RR 0.57 (95%CI 0.41–0.80)], ischemia-driven revascularization and resuscitation [RR 0.50 (95%CI 0.34–0.73)], myocardial infarction [RR 0.73 (95%CI 0.57–0.95)], and stroke [RR 0.49 (95%CI 0.30–0.7)]. Patients treated with colchicine in comparison with placebo have a significant increase in the risk of treatment cessation (RR 1.60 95%CI 1.06–2.42). However, in the analysis which excluded studies without placebo, the relative risk of discontinuation was smaller (RR 1.34 95%CI 0.97–1.84) and in the three largest studies, the risk of discontinuation was lower and insignificant [RR 1.26 (95%CI 0.87–1.83)]. The net clinical benefit was 17.8/1,000 patients (p < 0.001).

Conclusion: In coronary artery disease, low-dose colchicine significantly reduces the risk of the primary composite endpoint by about 30%. The drug should be considered as part of the preventive treatment in patients with good tolerance.

The inflammasome in heart failure

The NACHT, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome is a macromolecular structure responsible for the inflammatory response to injury or infection. Several types of heart disease are linked to the activity of the NLRP3 inflammasome and its cytokines, interleukin-1β (IL-1β), and IL-18. Recent pieces of evidence collected from human samples, together with experimental animal models, demonstrate a causative role for the pathogenesis and progression of heart failure (HF). Preclinical research showed that NLRP3 inhibition is a viable strategy to reduce adverse cardiac remodeling and improve left ventricular function in HF. Early phase clinical studies proved to be safe and effective supporting the potential benefit of blocking the NLRP3 inflammasome pathway in patients with HF.

Targeting the NLRP3 inflammasome in cardiovascular diseases

The NACHT, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome is an intracellular sensing protein complex that plays a major role in innate immunity. Following tissue injury, activation of the NLRP3 inflammasome results in cytokine production, primarily interleukin(IL)-1β and IL-18, and, eventually, inflammatory cell death - pyroptosis. While a balanced inflammatory response favors damage resolution and tissue healing, excessive NLRP3 activation causes detrimental effects. A key involvement of the NLRP3 inflammasome has been reported across a wide range of cardiovascular diseases (CVDs). Several pharmacological agents selectively targeting the NLRP3 inflammasome system have been developed and tested in animals and early phase human studies with overall promising results. While the NLRP3 inhibitors are in clinical development, multiple randomized trials have demonstrated the safety and efficacy of IL-1 blockade in atherothrombosis, heart failure and recurrent pericarditis. Furthermore, the non-selective NLRP3 inhibitor colchicine has been recently shown to significantly reduce cardiovascular events in patients with chronic coronary disease. In this review, we will outline the mechanisms driving NLRP3 assembly and activation, and discuss the pathogenetic role of the NLRP3 inflammasome in CVDs, providing an overview of the current and future therapeutic approaches targeting the NLRP3 inflammasome.

Regulation and functions of NLRP3 inflammasome in cardiac fibrosis: Current knowledge and clinical significance

Cardiac fibrosis can lead to heart failure, arrhythmia, and sudden cardiac death, representing one of the leading causes of death due to cardiovascular diseases. Cardiac fibrosis involves several multifactorial processes that cannot be effectively controlled by the available therapies. Therefore, current research has focused on the development of novel drugs that can be used to prevent cardiac fibrosis. Recent studies on the functions of inflammasome have provided an in-depth understanding of the regulatory functions of inflammasome in cardiac fibrosis. This review summarizes the latest research on the functions of the NLRP3 inflammasome in various cardiovascular diseases. The latest findings indicate that the NLRP3 inflammasome mediates several inflammatory responses and is associated with pyroptosis, mitochondrial regulation, and myofibroblast differentiation in cardiac fibrosis. These novel findings provide insight into the vital role of the NLRP3 inflammasome in the pathogenesis of cardiac fibrosis, which can be used to identify new targets for its prevention and treatment.

Colchicine efficacy and safety for the treatment of cardiovascular diseases

The emerging role of colchicine in the treatment of cardiovascular diseases is a strong demand for a comprehensive understanding of its efficacy and safety. This meta-analysis and systematic review aimed to study the efficacy in the reduction of adverse cardiovascular outcomes (CO), and the risk of colchicine-related adverse events (CRAEs). Fourteen thousand and nine eighty three patients from 22 randomized controlled trials (RCTs) were included, 9 in patients with coronary artery disease-CAD, 9 in patients with pericarditis, 4 in patients with atrial fibrillation-AF or heart failure. Colchicine was efficacious in the reduction of adverse CO across different settings: pericardial diseases (reduced risk of recurrent pericarditis, 17.6% vs. 35%, RR 0.50, 95% CI 0.41-0.61), CAD (reduced risk of cardiac death, myocardial infarction, stroke,coronary revascularization or hospitalization, 6.1% vs. 8.5%, RR 0.73, 95% CI 0.64-0.83), AF (reduced risk of arrhythmia recurrence, 14.2% vs. 22.7%, RR 0.62, 95% CI 0.44-0.88). Colchicine was associated with increased risk of gastrointestinal CRAEs (11.2% vs. 8.8%, RR 1.87, 95% CI 1.41-2.47) and drug discontinuation (5.4% vs. 3.7%, RR 1.58, 95% CI 1.25-1.99). In both cases, the risk was proportional to the daily dose or duration of treatment, possibly due to early drug discontinuation or tolerance. Other CRAEs (muscle-related, liver,hematologic,cutaneous, infections) were not increased by colchicine, as long as all-cause death (2.2% vs. 1.9%, RR 1.11, 95% CI 0.79-1.54) or non-cardiovascular death (1.5% vs. 1%, RR 1.43, 95% CI 0.93-2.19). Colchicine is efficacious and safe for the treatment of cardiovascular diseases. The risk of gastrointestinal CRAEs and drug discontinuation is not significant if colchicine is used at lower doses (0.5 mg daily) or for longer periods of time (> 6 months).

Colchicine-Containing Nanoparticles Attenuates Acute Myocardial Infarction Injury by Inhibiting Inflammation

PURPOSE

Anti-inflammatory therapy is important for reducing myocardial injury after acute myocardial infarction (MI). New anti-inflammatory drugs and their mechanism are necessary to be explored to improve clinical efficacy. We aimed to improve the efficacy of colchicine on attenuating MI injury by nano-drug delivery systems and to investigate the mechanism of anti-inflammatory.

METHODS

A colchicine-containing delivery system based on calcium carbonate nanoparticles (ColCaNPs) was synthesized. The protection against MI by ColCaNPs was evaluated using an in vivo rat model established by ligating the left anterior descending coronary artery. Macrophage polarization and the levels of inflammatory cytokines were determined using immunohistochemistry, Western blot, and ELISA analysis.

RESULTS

ColCaNP treatment showed about a 45% reduction in myocardial infarct size and attenuating myocardial fibrosis compared with groups without drug intervention after MI. Furthermore, ColCaNPs significantly decreased the levels of CRP, TNF-α, and IL-1β in serum and the expression of proinflammatory cytokine in myocardial tissues after MI (p < 0.05). We also found that ColCaNPs notably restrained pyroptosis and inhibited inflammatory response by modulating on M1/M2 macrophage polarization and suppressing TLR4/NFκB/NLRP3 signal pathway.

CONCLUSION

Colchicine-containing nanoparticles can protect against MI injury in a clinically relevant rat model by reducing inflammation. In addition, calcium carbonate nanoparticles can increase the cardioprotective effects of colchicine.

Promise of the NLRP3 Inflammasome Inhibitors in In Vivo Disease Models

Nucleotide-binding oligomerization domain NOD-like receptors (NLRs) are conserved cytosolic pattern recognition receptors (PRRs) that track the intracellular milieu for the existence of infection, disease-causing microbes, as well as metabolic distresses. The NLRP3 inflammasome agglomerates are consequent to sensing a wide spectrum of pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs). Certain members of the NLR family have been documented to lump into multimolecular conglomerates called inflammasomes, which are inherently linked to stimulation of the cysteine protease caspase-1. Following activation, caspase-1 severs the proinflammatory cytokines interleukin (IL)-1β and IL-18 to their biologically active forms, with consequent commencement of caspase-1-associated pyroptosis. This type of cell death by pyroptosis epitomizes a leading pathway of inflammation. Accumulating scientific documentation has recorded overstimulation of NLRP3 (NOD-like receptor protein 3) inflammasome involvement in a wide array of inflammatory conditions. IL-1β is an archetypic inflammatory cytokine implicated in multiple types of inflammatory maladies. Approaches to impede IL-1β's actions are possible, and their therapeutic effects have been clinically demonstrated; nevertheless, such strategies are associated with certain constraints. For instance, treatments that focus on systemically negating IL-1β (i.e., anakinra, rilonacept, and canakinumab) have been reported to result in an escalated peril of infections. Therefore, given the therapeutic promise of an NLRP3 inhibitor, the concerted escalated venture of the scientific sorority in the advancement of small molecules focusing on direct NLRP3 inflammasome inhibition is quite predictable.

WBC count predicts heart failure in diabetes and coronary artery disease patients: a retrospective cohort study

Aims

White blood cell (WBC) count in healthy people is associated with the risk of coronary artery disease (CAD) and mortality. This study aimed to determine whether WBC count predicts heart failure (HF) requiring hospitalization as well as all‐cause death, acute myocardial infarction (AMI) and stroke in patients with Type 2 diabetes mellitus and established CAD.

Methods

We conducted this retrospective registry study that enrolled consecutive patients with Type 2 diabetes mellitus and CAD based on coronary arteriography records and medical charts at 70 teaching hospitals in Japan from 2005 to 2015. A total of 7608 participants (28.2% women, mean age 68 ± 10 years) were eligible. In the cohort, the median (interquartile range) and mean follow‐up durations were 39 (16.5–66.1 months) and 44.3 ± 32.7 months, respectively. The primary outcome was HF requiring hospitalization. The secondary outcomes were AMI, stroke, all‐cause death, 3‐point major adverse cardiovascular events (MACE) (AMI/stroke/death) and 4‐point MACE (AMI/stroke/death/HF requiring hospitalization). Outcomes were reported as cumulative incidences (proportion of patients experiencing an event) and incidence rates (events/100 person‐years). The primary and secondary outcomes were assessed using the Kaplan–Meier method and were compared using the log‐rank test stratified by the baseline WBC count. The association between the WBC count at baseline and each MACE was assessed using the Cox proportional hazard model and expressed as the hazard ratio (HR) and 95% confidence interval (CI) after adjusting for other well‐known risk factors for MACE.

Results

During the follow‐up, 880 patients were hospitalized owing to HF. The WBC Quartile 4 (≥7700 cells/μL) had significantly lower HF event‐free survival rate (log‐rank test, P < 0.001). The HRs for HF events requiring hospitalization with each WBC quartile compared with the lowest in the first WBC quartile were 1 for Quartile 1 (WBC < 5300 cells/μL), 1.20 (95% CI, 0.96–1.5; P = 0.1) for Quartile 2 (5300 ≤ WBC < 6400), 1.34 (95% CI, 1.08–1.67; P = 0.009) for Quartile 3 (6400 ≤ WBC < 7700) and 1.62 (95% CI, 1.31–2.00; P < 0.001) for Quartile 4 after adjusting for covariates. Similar findings were observed for the risk of AMI and death; however, no significant difference was found for stroke. WBC Quartile 4 patients had a significantly lower 3‐ or 4‐point MACE‐free survival rate (log‐rank test, P < 0.0001).

Conclusions

A higher WBC count is a predictor of hospitalization for HF, all‐cause death and AMI but not for stroke in patients with concurrent Type 2 diabetes mellitus and established CAD.

Mitochondrial Arrest on the Microtubule Highway-A Feature of Heart Failure and Diabetic Cardiomyopathy?

A pathophysiological consequence of both type 1 and 2 diabetes is remodelling of the myocardium leading to the loss of left ventricular pump function and ultimately heart failure (HF). Abnormal cardiac bioenergetics associated with mitochondrial dysfunction occurs in the early stages of HF. Key factors influencing mitochondrial function are the shape, size and organisation of mitochondria within cardiomyocytes, with reports identifying small, fragmented mitochondria in the myocardium of diabetic patients. Cardiac mitochondria are now known to be dynamic organelles (with various functions beyond energy production); however, the mechanisms that underpin their dynamism are complex and links to motility are yet to be fully understood, particularly within the context of HF. This review will consider how the outer mitochondrial membrane protein Miro1 (Rhot1) mediates mitochondrial movement along microtubules via crosstalk with kinesin motors and explore the evidence for molecular level changes in the setting of diabetic cardiomyopathy. As HF and diabetes are recognised inflammatory conditions, with reports of enhanced activation of the NLRP3 inflammasome, we will also consider evidence linking microtubule organisation, inflammation and the association to mitochondrial motility. Diabetes is a global pandemic but with limited treatment options for diabetic cardiomyopathy, therefore we also discuss potential therapeutic approaches to target the mitochondrial-microtubule-inflammatory axis.

Efficacy and Safety of Colchicine in Post-acute Myocardial Infarction Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Inflammation plays a key role in atherosclerotic plaque destabilization and adverse cardiac remodeling. Recent evidence has shown a promising role of colchicine in patients with coronary artery disease. We evaluated the efficacy and safety of colchicine in post–acute myocardial infarction (MI) patients.

Methods: We searched five electronic databases from inception to January 18, 2021, for randomized controlled trials (RCTs) evaluating colchicine in post–acute MI patients. Primary outcomes were cardiovascular mortality and recurrent MI. Secondary outcomes were all-cause mortality, stroke, urgent coronary revascularization, levels of follow-up high-sensitivity C-reactive protein (hs-CRP), and drug-related adverse events. All meta-analyses used inverse-variance random-effects models.

Results: Six RCTs involving 6,005 patients were included. Colchicine did not significantly reduce cardiovascular mortality [risk ratio (RR), 0.91; 95% confidence interval (95% CI), 0.52–1.61; p = 0.64], recurrent MI (RR, 0.87; 95% CI, 0.62–1.22; p = 0.28), all-cause mortality (RR, 1.06; 95% CI, 0.61–1.85; p = 0.78), stroke (RR, 0.28; 95% CI, 0.07–1.09; p = 0.05), urgent coronary revascularization (RR, 0.46; 95% CI, 0.02–8.89; p = 0.19), or decreased levels of follow-up hs-CRP (mean difference, −1.95 mg/L; 95% CI, −12.88 to 8.98; p = 0.61) compared to the control group. There was no increase in any adverse events (RR, 0.97; 95% CI, 0.89–1.07; p = 0.34) or gastrointestinal adverse events (RR, 2.49; 95% CI, 0.48–12.99; p = 0.20). Subgroup analyses by colchicine dose (0.5 vs. 1 mg/day), time of follow-up (<1 vs. ≥1 year), and treatment duration (≤30 vs. >30 days) showed no changes in the overall findings.

Conclusion: In post–acute MI patients, colchicine does not reduce cardiovascular or all-cause mortality, recurrent MI, or other cardiovascular outcomes. Also, colchicine did not increase drug-related adverse events.

Inflammasome Activation-Induced Hypercoagulopathy: Impact on Cardiovascular Dysfunction Triggered in COVID-19 Patients

Coronavirus disease 2019 (COVID-19) is the most devastating infectious disease in the 21st century with more than 2 million lives lost in less than a year. The activation of inflammasome in the host infected by SARS-CoV-2 is highly related to cytokine storm and hypercoagulopathy, which significantly contribute to the poor prognosis of COVID-19 patients. Even though many studies have shown the host defense mechanism induced by inflammasome against various viral infections, mechanistic interactions leading to downstream cellular responses and pathogenesis in COVID-19 remain unclear. The SARS-CoV-2 infection has been associated with numerous cardiovascular disorders including acute myocardial injury, myocarditis, arrhythmias, and venous thromboembolism. The inflammatory response triggered by the activation of NLRP3 inflammasome under certain cardiovascular conditions resulted in hyperinflammation or the modulation of angiotensin-converting enzyme 2 signaling pathways. Perturbations of several target cells and tissues have been described in inflammasome activation, including pneumocytes, macrophages, endothelial cells, and dendritic cells. The interplay between inflammasome activation and hypercoagulopathy in COVID-19 patients is an emerging area to be further addressed. Targeted therapeutics to suppress inflammasome activation may have a positive effect on the reduction of hyperinflammation-induced hypercoagulopathy and cardiovascular disorders occurring as COVID-19 complications.

NLRP3 Inflammasome Inhibitors in Cardiovascular Diseases

Virtually all types of cardiovascular diseases are associated with pathological activation of the innate immune system. The NACHT, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome is a protein complex that functions as a platform for rapid induction of the inflammatory response to infection or sterile injury. NLRP3 is an intracellular sensor that is sensitive to danger signals, such as ischemia and extracellular or intracellular alarmins during tissue injury. The NLRP3 inflammasome is regulated by the presence of damage-associated molecular patterns and initiates or amplifies inflammatory response through the production of interleukin-1β (IL-1β) and/or IL-18. NLRP3 activation regulates cell survival through the activity of caspase-1 and gasdermin-D. The development of NLRP3 inflammasome inhibitors has opened the possibility to targeting the deleterious effects of NLRP3. Here, we examine the scientific evidence supporting a role for NLRP3 and the effects of inhibitors in cardiovascular diseases.