Deletion of Apoptosis Inhibitor of Macrophage (AIM)/CD5L Attenuates the Inflammatory Response and Infarct Size in Acute Myocardial Infarction

CD5L induces inflammation and survival in RA-FLS through ERK1/2 MAPK pathway

OBJECTIVE

To explore the effect of CD5-like molecule (CD5L) on rheumatoid arthritis (RA) fibroblast-like synoviocytes (RA-FLS) and the relative molecular mechanism of CD5L in it.

METHODS

Recombinant protein CD5L was used to stimulate the cultured RA-FLS cells. The inflammation-related cytokines were determined by real time-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). The signal molecules and apoptosis-related molecules were detected by western blot assay (WB), and cell counting kit-8 (CCK-8) was used to detect the proliferation.

RESULTS

CD5L can increase the production of IL-6, IL-8, and TNF-α and this effect can be inhibited by signal pathway inhibitor. At the same time, CD5L activated ERK1/2 MAPK signal, inhibitor treatment can weaken the intensity of phosphorylation. In addition, CD5L can enhance the proliferation ability of RA-FLS.

CONCLUSION

CD5L induces the production of inflammatory cytokines in RA-FLS through the ERK1/2 MAPK pathway and increases cell survival.

Administration of an antibody against apoptosis inhibitor of macrophage prevents aortic aneurysm progression in mice

Apoptosis inhibitor of macrophage (AIM) is known to induce apoptosis resistance in macrophages and to exacerbate chronic inflammation, leading to arteriosclerosis. The role of AIM in aortic aneurysm (AA) remains unknown. This study examined the effects of an anti-AIM antibody in preventing AA formation and progression. In apolipoprotein E-deficient mice, AA was induced by subcutaneous angiotensin II infusion. Mice were randomly divided into two groups: (i) AIM group; weekly anti-murine AIM monoclonal antibody injection (n = 10), and (ii) IgG group; anti-murine IgG antibody injection as control (n = 14). The AIM group, compared with the IgG group, exhibited reduced AA enlargement (aortic diameter at 4 weeks: 2.1 vs. 2.7 mm, respectively, p = 0.012); decreased loss of elastic lamellae construction; reduced expression levels of IL-6, TNF-α, and MCP-1; decreased numbers of AIM-positive cells and inflammatory M1 macrophages (AIM: 1.4 vs. 8.0%, respectively, p = 0.004; M1 macrophages: 24.5 vs. 55.7%, respectively, p = 0.017); and higher expression of caspase-3 in the aortic wall (22.8 vs. 10.5%, respectively, p = 0.019). Our results suggest that administration of an anti-AIM antibody mitigated AA progression by alleviating inflammation and promoting M1 macrophage apoptosis.

The effects of apoptosis inhibitor of macrophage in kidney diseases

Kidney disease is a progressive and irreversible condition in which immunity is a contributing factor that endangers human health. It is widely acknowledged that macrophages play a significant role in developing and causing numerous kidney diseases. The increasing focus on the mechanism by which macrophages express apoptosis inhibitor of macrophages (AIM) in renal diseases has been observed. AIM is an apoptosis inhibitor that stops different things that cause apoptosis from working. This keeps AIM-bound cell types alive. Notably, the maintenance of immune cell viability regulates immunity. As our investigation progressed, we concluded that AIM has two sides when it comes to renal diseases. AIM can modulate renal phagocytosis, expedite the elimination of renal tubular cell fragments, and mitigate tissue injury. AIM can additionally exacerbate the development of renal fibrosis and kidney disease by prolonging inflammation. IgA nephropathy (IgAN) may also worsen faster if more protein is in the urine. This is because IgA and immunoglobulin M are found together and expressed. In the review, we provide a comprehensive overview of prior research and concentrate on the impacts of AIM on diverse subcategories of nephropathies. We discovered that AIM is closely associated with renal diseases by playing a positive or negative role in the onset, progression, or cure of kidney disease. AIM is thus a potentially effective therapeutic target for kidney diseases.

Circ-SUZ12 Protects Cardiomyocytes from Hypoxia-Induced Dysfunction Through Upregulating SUZ12 Expression to Activate Wnt/β-catenin Signaling Pathway

Acute myocardial infarction (AMI) is a common coronary artery disease. This study attempted to reveal the impact of circ-SUZ12 (hsa_circ_0042961) on cardiomyocyte injury after exposure to hypoxia.Circ-SUZ12 was screened out from the GEO dataset GSE169594. RNA expression and protein level were detected by quantitative real-time PCR (qRT-PCR) and Western blot, respectively. The characteristics of circ-SUZ12 were identified by measuring its resistance to Rnase R or actinomycin D (Act D) treatment. CCK-8 and EdU assays were performed to explore the viability of AC16 cells. Cell apoptosis was assessed through TUNEL assay and flow cytometry analysis. Mechanism experiments were performed to investigate the downstream molecular mechanism of circ-SUZ12.Circ-SUZ12 was highly expressed in blood samples of AMI patients in the GEO dataset and lowly expressed in hypoxia-treated cardiomyocytes. Overexpression of circ-SUZ12 reversed hypoxia-induced cardiomyocyte injury. Circ-SUZ12 regulated SUZ12 polycomb repressive complex 2 subunit (SUZ12) expression by recruiting FUS protein. SUZ12 activated the Wnt/β-catenin signaling pathway by increasing the H3K27me3 level in microRNA (miR)-526b-5p promoter to release catenin beta 1 (CTNNB1). CTNNB1 depletion reversed the effect of circ-SUZ12 on the viability and apoptosis of hypoxia-induced cardiomyocytes.Circ-SUZ12 protects cardiomyocytes from hypoxia-induced dysfunction through upregulating SUZ12 expression to activate the Wnt/β-catenin signaling pathway.

CD5L aggravates rheumatoid arthritis progression via promoting synovial fibroblasts proliferation and activity

Rheumatoid arthritis (RA) is a chronic inflammatory disease with progressive cartilage erosion and joint destruction. Synovial fibroblasts (SFs) play a crucial role in the pathogenesis of RA. This study aims to explore the function and mechanism of CD5L during RA progression. We examined the levels of CD5L in synovial tissues and SFs. The collagen-induced arthritis (CIA) rat models were used to investigate the effect of CD5L on RA progression. We also investigated the effects of exogenous CD5L on the behavior and activity of RA synovial fibroblasts (RASFs). Our results showed that CD5L expression was significantly upregulated in synovium of RA patients and CIA-rats. Histology and Micro-CT analysis showed that synovial inflammation and bone destruction were more severe in CD5L-treated CIA rats compared with control rats. Correspondingly, CD5L blockade alleviated bone damage and synovial inflammation in CIA-rats. The exogenous CD5L treatment promoted RASFs proliferation invasion and proinflammatory cytokine production. Knockdown of CD5L receptor by siRNA significantly reversed the effect of CD5L treatment on RASFs. Moreover, we observed that CD5L treatment potentiated PI3K/Akt signaling in the RASFs. The promoted effects of CD5L on IL-6 and IL-8 expression were significantly reversed by PI3K/Akt signaling inhibitor. In conclusion, CD5L promote RA disease progression via activating RASFs. CD5L blocking is a potential therapeutic approach for RA patients.

Apoptosis inhibitor of macrophage (AIM)/CD5L is involved in the pathogenesis of COPD

BACKGROUND

Alveolar macrophages (AMs) and AM-produced matrix metalloprotease (MMP)-12 are known to play critical roles in the pathogenesis of chronic obstructive pulmonary disease (COPD). The apoptosis inhibitor of the macrophages (AIM)/CD5 molecule-like (CD5L) is a multifunctional protein secreted by the macrophages that mainly exists in the blood in a combined form with the immunoglobulin (Ig)M pentamer. Although AIM has both facilitative and suppressive roles in various diseases, its role in COPD remains unclear.

METHODS

We investigated the role of AIM in COPD pathogenesis using porcine pancreas elastase (PPE)-induced and cigarette smoke-induced emphysema mouse models and an in vitro model using AMs. We also analyzed the differences in the blood AIM/IgM ratio among nonsmokers, healthy smokers, and patients with COPD and investigated the association between the blood AIM/IgM ratio and COPD exacerbations and mortality in patients with COPD.

RESULTS

Emphysema formation, inflammation, and cell death in the lungs were attenuated in AIM-/- mice compared with wild-type (WT) mice in both PPE- and cigarette smoke-induced emphysema models. The PPE-induced increase in MMP-12 was attenuated in AIM-/- mice at both the mRNA and protein levels. According to in vitro experiments using AMs stimulated with cigarette smoke extract, the MMP-12 level was decreased in AIM-/- mice compared with WT mice. This decrease was reversed by the addition of recombinant AIM. Furthermore, an analysis of clinical samples showed that patients with COPD had a higher blood AIM/IgM ratio than healthy smokers. Additionally, the blood AIM/IgM ratio was positively associated with disease severity in patients with COPD. A higher AIM/IgM ratio was also associated with a shorter time to the first COPD exacerbation and higher all-cause and respiratory mortality.

CONCLUSIONS

AIM facilitates the development of COPD by upregulating MMP-12. Additionally, a higher blood AIM/IgM ratio was associated with poor prognosis in patients with COPD.

TRIAL REGISTRATION

This clinical study, which included nonsmokers, healthy smokers, and smokers with COPD, was approved by the Ethics Committee of the Hokkaido University Hospital (012-0075, date of registration: September 5, 2012). The Hokkaido COPD cohort study was approved by the Ethics Committee of the Hokkaido University School of Medicine (med02-001, date of registration: December 25, 2002).

The comprehensive role of apoptosis inhibitor of macrophage (AIM) in pathological conditions

CD5L/AIM (apoptosis inhibitor of macrophage), as an important component in maintaining tissue homeostasis and inflammation, is mainly produced and secreted by macrophages but partially dissociated and released from blood AIM-IgM. AIM plays a regulatory role in intracellular physiological mechanisms, including lipid metabolism and apoptosis. AIM not only increases in autoimmune diseases, directly targets liver cells in liver cancer and promotes cell clearance in acute kidney injury, but also causes arteriosclerosis and cardiovascular events, and aggravates inflammatory reactions in lung diseases and sepsis. Obviously, AIM plays a pleiotropic role in the body. However, to date, studies have failed to decipher the mechanisms behind its different roles (beneficial or harmful) in inflammatory regulation. The inflammatory response is a "double-edged sword," and maintaining balance is critical for effective host defense while minimizing the adverse side effects of acute inflammation. Enhancing the understanding of AIM function could provide the theoretical basis for new therapies in these pathological settings. In this review, we discuss recent studies on the roles of AIM in lipid metabolism, autoimmune diseases and organic tissues, such as liver cancer, myocardial infarction, and kidney disease.

IL-38 attenuates myocardial ischemia-reperfusion injury by inhibiting macrophage inflammation

BACKGROUND

Reperfusion therapy is the most effective approach to resolve coronary occlusion, but myocardial injury caused by excessive inflammation during myocardial ischemia-reperfusion will also pose a new threat to health. Our prior study revealed the expression pattern of interleukin-38 (IL-38) in the peripheral blood serum of patients with ischemic cardiomyopathy and the role of IL-38 in acute myocardial infarction in mice. However, its role and potential mechanisms in myocardial ischemia/reperfusion injury (MIRI) remain to be determined.

METHODS AND RESULTS

The left anterior descending artery of C57BL/6 mice was transiently ligated to induce the MIRI model. We found that MIRI induced the expression of endogenous IL-38, which was mainly produced by locally infiltrating macrophages. Overexpression of IL-38 in C57BL/6 mice attenuated inflammatory injury and decreased myocardial apoptosis after myocardial ischemia-reperfusion. Furthermore, IL-38 inhibited lipopolysaccharide-induced macrophage inflammation in vitro. Cardiomyocytes cocultured with the supernatant of IL-38- and troponin I-treated macrophages showed a lower rate of apoptosis than controls.

CONCLUSIONS

IL-38 attenuates MIRI by inhibiting macrophage inflammation. This inhibitory effect may be partially achieved by inhibiting the activation of NOD-like receptor pyrin domain-related protein 3 inflammasome, resulting in decreased expression of inflammatory factors and reduced cardiomyocyte apoptosis.

Intratympanic steroid treatment can reduce ROS and immune response in human perilymph investigated by in-depth proteome analysis

Intratympanic (IT) steroid treatment is one of the most widely used and effective treatments for inner ear disorders such as sudden sensorineural hearing loss (SNHL). However, a clear mechanism of IT steroids in inner ear recovery has not yet been revealed. Therefore, we investigated proteome changes in extracted human perilymph after steroid treatment. In this study, we applied a tandem mass spectrometry (MS/MS)-based proteomics approach to discover global proteome changes by comparing human perilymph after steroid treatment with non-treated perilymph group. Using liquid chromatography-MS/MS analysis, we selected 156 differentially expressed proteins (DEPs) that were statistically significant according to Student's t-test. Functional annotation analysis showed that upregulated proteins after steroid treatment are related to apoptosis signaling, as well as reactive oxygen species (ROS) and immune responses. The protein-protein interaction (PPI) clusters the proteins associated with these processes and attempts to observe signaling circuitry, which mediates cellular response after IT steroid treatments. Moreover, we also considered the interactome analysis of DEPs and observed that those with high interaction scores were categorized as having equivalent molecular functions (MFs). Collectively, we suggest that DEPs and interacting proteins in human perilymph after steroid treatment would inhibit the apoptotic and adaptive immune processes that may lead to anti-inflammatory effects.

An overview of long noncoding RNAs: Biology, functions, therapeutics, analysis methods, and bioinformatics tools

Long noncoding RNAs (lncRNAs) are a diverse class of RNAs whose functions are widespread in all branches of life and have been the focus of attention in the last decade. While a huge number of lncRNAs have been identified, there is still much work to be done and plenty to be learned. In the current review, we begin with the biogenesis and function of lncRNAs as they are involved in the different cellular processes from regulating the architecture of chromosomes to controlling translation and post-translation modifications. Questions on how overexpression, mutations, or deficiency of lncRNAs can affect the cellular status and result in the pathogenesis of various human diseases are responded to. Besides, we allocate an overview of several studies, concerning the application of lncRNAs either as diagnostic and prognostic biomarkers or novel therapeutics. We also introduce the currently available techniques to explore details of lncRNAs such as their function, cellular localization, and structure. In the last section, as exponentially growing data in this area need to be gathered and organized in comprehensive databases, we have a particular focus on presenting general and specialized databases. Taken together, with this review, we aim to provide the latest information on different aspects of lncRNAs to highlight their importance in physiopathologic states and take a step towards helping future studies.

An antioxidant system through conjugating superoxide dismutase onto metal-organic framework for cardiac repair

Acute myocardial infarction (AMI) remains a dominant origin of morbidity, mortality and disability worldwide. Increases in reactive oxygen species (ROS) are key contributor to excessive cardiac injury after AMI. Here we developed an immobilized enzyme with Superoxide Dismutase (SOD) activity cross-link with Zr-based metal-organic framework (ZrMOF) (SOD-ZrMOF) for mitigate ROS-caused injury. In vitro and in vivo evidence indicates that SOD-ZrMOF exhibits excellent biocompatibility. By efficiently scavenging ROS and suppressing oxidative stress, SOD-ZrMOF can protect the function of mitochondria, reduce cell death and alleviate inflammation. More excitingly, long-term study using an animal model of AMI demonstrated that SOD-ZrMOF can reduce the infarct area, protect cardiac function, promote angiogenesis and inhibit pathological myocardial remodeling. Therefore, SOD-ZrMOF holds great potential as an efficacious and safe nanomaterial treatment for AMI.

CD5L deficiency attenuate acetaminophen-induced liver damage in mice via regulation of JNK and ERK signaling pathway

CD5 molecule like (CD5L), a member of the scavenger receptor cysteine-rich domain superfamily, plays a critical role in immune homeostasis and inflammatory disease. Acetaminophen (APAP) is a safe and effective antipyretic analgesic. However, overdose may cause liver damage or even liver failure. APAP hepatotoxicity is characterized by extensive necrotic cell death and a sterile inflammatory response, in which the role of CD5L remains to be investigated. In this study, we found that the expression of CD5L was increased in the livers of mice after APAP overdose. Furthermore, CD5L deficiency reduced the increase of alanine transaminase (ALT) level, histopathologic lesion area, c-Jun N-terminal kinase (JNK)/extracellular signal-regulated kinase (ERK) phosphorylation level, Transferase-Mediated dUTP Nick End-Labeling positive (TUNEL⁺) cells proportion, vascular endothelial cell permeability and release of inflammatory cytokines induced by excess APAP. Therefore, our findings reveal that CD5L may be a potential therapeutic target for prevention and treatment of APAP-induced liver injury.

Circulating CD5L is associated with cardiovascular events and all-cause mortality in individuals with chronic kidney disease

This study assessed the association of CD5L and soluble CD36 (sCD36) with the risk of a cardiovascular event (CVE), including CV death and all-cause mortality in CKD. We evaluated the association of CD5L and sCD36 with a predefined composite CV endpoint (unstable angina, myocardial infarction, transient ischemic attack, cerebrovascular accident, congestive heart failure, arrhythmia, peripheral arterial disease [PAD] or amputation by PAD, aortic aneurysm, or death from CV causes) and all-cause mortality using Cox proportional hazards regression, adjusted for CV risk factors. The analysis included 1,516 participants free from pre-existing CV disease followed up for 4 years. The median age was 62 years, 38.8% were female, and 26.8% had diabetes. There were 98 (6.5%) CVEs and 72 (4.8%) deaths, of which 26 (36.1%) were of CV origin. Higher baseline CD5L concentration was associated with increased risk of CVE (HR, 95% CI, 1.17, 1.0–1.36), and all-cause mortality (1.22, 1.01–1.48) after adjusting for age, sex, diabetes, systolic blood pressure, dyslipidemia, waist circumference, smoking, and CKD stage. sCD36 showed no association with adverse CV outcomes or mortality. Our study showed for the first time that higher concentrations of CD5L are associated with future CVE and all-cause mortality in individuals with CKD.

The Protective Role of the Long Pentraxin PTX3 in Spontaneously Hypertensive Rats with Heart Failure

Pentraxin 3 (PTX3) is synthesized locally and released into the circulation, reflecting local inflammation in the cardiovascular system. Therefore, we conducted a study to explore the effect of PTX3 in spontaneously hypertensive heart failure (SHHF) rats. Sprague Dawley (SD) and SHHF rats were treated with recombinant PTX3 protein, and the blood pressure (BP) and echocardiographic parameters were collected. Radioimmunoassay, enzyme immunoassay and enzyme-linked immunosorbent assay (ELISA) were applied to detect plasma levels of atrial/B-type natriuretic peptide (ANP/BNP) and PTX3. The pathological changes in the myocardial tissues were observed by hematoxylin and eosin (HE) and Masson stainings. The mRNA and protein expressions were detected by quantitative real-time reverse-transcription polymerase chain reaction (qPCR) and western blotting. Cardiomyocyte apoptosis was evaluated by TUNEL staining and DNA fragmentation test. Increased plasma concentrations of PTX3 were found in SHHF rats compared with SD rats, which was further enhanced by recombinant PTX3 protein. After injection with recombinant PTX3 protein, the heart function was improved in SHHF rats with the decreased systolic and diastolic BP, and the reduced plasma levels of ANP and BNP. Moreover, PTX3 improved the myocardial damage and interstitial fibrosis in SHHF rats with reduced cardiomyocyte apoptosis and decreased mRNA expressions of pro-inflammatory factors in myocardial tissues. PTX3 could decrease the BP and plasma levels of ANP and BNP in SHHF rats, as well as improve the inflammation, cardiomyocyte apoptosis, and pathological changes of myocardial tissues, suggesting it may be a useful intervention in the treatment of SHHF.

Emerging role of non-coding RNA in health and disease

Human diseases have always been a significant turf of concern since the origin of mankind. It is cardinal to know the cause, treatment, and cure for every disease condition. With the advent and advancement in technology, the molecular arena at the microscopic level to study the mechanism, progression, and therapy is more rational and authentic pave than a macroscopic approach. Non-coding RNAs (ncRNAs) have now emerged as indispensable players in the diagnosis, development, and therapeutics of every abnormality concerning physiology, pathology, genetics, epigenetics, oncology, and developmental diseases. This is a comprehensive attempt to collate all the existing and proven strategies, techniques, mechanisms of genetic disorders including Silver Russell Syndrome, Fascio- scapula humeral muscular dystrophy, cardiovascular diseases (atherosclerosis, cardiac fibrosis, hypertension, etc.), neurodegenerative diseases (Spino-cerebral ataxia type 7, Spino-cerebral ataxia type 8, Spinal muscular atrophy, Opitz-Kaveggia syndrome, etc.) cancers (cervix, breast, lung cancer, etc.), and infectious diseases (viral) studied so far. This article encompasses discovery, biogenesis, classification, and evolutionary prospects of the existence of this junk RNA along with the integrated networks involving chromatin remodelling, dosage compensation, genome imprinting, splicing regulation, post-translational regulation and proteomics. In conclusion, all the major human diseases are discussed with a facilitated technology transfer, advancements, loopholes, and tentative future research prospects have also been proposed.

Overexpression of circRNA SNRK targets miR-103-3p to reduce apoptosis and promote cardiac repair through GSK3β/β-catenin pathway in rats with myocardial infarction

Ischemic cardiomyopathy seriously endangers human health leading to a poor prognosis. Acute myocardial infarction (AMI) is the primary etiology, and the pathophysiological process concludes with the death of cardiomyocytes caused by acute and persistent ischemia and hypoxia in the coronary arteries. We identified a circRNA (circSNRK) which was downregulated in rats with myocardial infarction (MI), however, the role it plays in the MI environment is still unclear. This study contained experiments to investigate the role of circSNRK in the regulation of cardiac survival and explore the mechanisms underlying circSNRK functions. Quantitative real-time PCR (qRT-PCR) was performed to determine the circSNRK expression patterns in hearts. Gain-of-function assays were also conducted in vitro and in vivo to determine the role of circSNRK in cardiac repair. qRT-PCR, western blot, and luciferase reporter assays were used to study circRNA interactions with micro RNAs (miRNAs). Overexpression of circSNRK in cardiomyocytes reduced apoptosis and increased proliferation. Adeno associated virus 9 (AAV9) mediated myocardium overexpression of circSNRK in post MI hearts reduced cardiomyocyte apoptosis, promoted cardiomyocyte proliferation, enhanced angiogenesis, and improved cardiac functions. Overall, upregulation of circSNRK promotes cardiac survival and functional recovery after MI. Mechanistically, circSNRK regulates cardiomyocyte apoptosis and proliferation by acting as a miR-103-3p sponge and inducing increased expression of SNRK which can bind GSK3β to regulate its phosphorylated activity. And thus circSNRK may be a promising therapeutic target for improving clinical prognosis after MI.

Multifaceted Roles of CD5L in Infectious and Sterile Inflammation

CD5L, a protein expressed and secreted mainly by macrophages, is emerging as a critical immune effector. In addition to its well-defined function as an anti-apoptotic protein, research over the last decade has uncovered additional roles that range from pattern recognition to autophagy, cell polarization, and the regulation of lipid metabolism. By modulating all these processes, CD5L plays a key role in highly prevalent diseases that develop by either acute or chronic inflammation, including several infectious, metabolic, and autoimmune conditions. In this review, we summarize the current knowledge of CD5L and focus on the relevance of this protein during infection- and sterile-driven inflammatory pathogenesis, highlighting its divergent roles in the modulation of inflammation.

miR-22 Host Gene Enhances Nuclear Factor-kappa B Activation to Aggravate Hypoxia-induced Injury in AC16 Cardiomyocytes

Myocardial infarction (MI) is a severe life-threatening disease caused by acute and persistent ischemia and hypoxia and eventually leads to heart failure and sudden death. Long noncoding RNAs (lncRNAs) play significant roles in the pathology, diagnosis, and development of various cardiovascular diseases, including MI. This study aimed to explore the effect and molecular mechanism of lncRNA miR-22 host gene (MIR22HG) on hypoxia-induced injury in AC16 cardiomyocytes. The expression of MIR22HG and miR-24 in hypoxia-treated AC16 cardiomyocytes was detected by quantitative real-time polymerase chain reaction. Cell viability, lactate dehydrogenase release, levels of aspartate aminotransferase (AST) and creatine kinase-MB (CK-MB), and apoptosis were detected by Cell Counting Kit-8, lactate dehydrogenase (LDH) release assay, commercial enzyme-linked immune sorbent assay kits, and flow cytometry analysis, respectively. The protein levels of nuclear factor-kappa B (NF-κB) p65 and cytoplasmic inhibitor of kappa B alpha (IκBα) and phosphorylated IκBα were detected by western blot. Results showed that hypoxia treatment decreased viability and increased MIR22HG expression in AC16 cardiomyocytes. MIR22HG overexpression aggravated hypoxia-induced viability reduction, leakage of myocardial injury markers LDH, AST, and CK-MB, and apoptosis in AC16 cardiomyocytes, while MIR22HG knockdown elicited the reverse effects. MIR22HG overexpression enhanced NF-κB activation in hypoxia-treated AC16 cardiomyocytes. Inhibition of NF-κB pathway impaired the effects of MIR22HG overexpression on hypoxia-induced injury in AC16 cardiomyocytes. Moreover, MIR22HG knockdown inhibited the NF-κB pathway by upregulating miR-24 in AC16 cardiomyocytes. Inhibition of miR-24 resisted the effects of MIR22HG silencing on hypoxia-induced injury in AC16 cardiomyocytes. In conclusion, MIR22HG overexpression aggravated hypoxia-induced injury in AC16 cardiomyocytes via enhancing NF-κB activation by targeting miR-24.

Association between apoptosis inhibitor of macrophage and microsatellite instability status in colorectal cancer

BACKGROUND

The microsatellite instability (MSI) in colorectal cancer (CRC) has a more favorable clinical outcome and is characterized by highly upregulated expression of various immunological checkpoints than microsatellite stable (MSS) tumors. Apoptosis inhibitor of macrophage (AIM) is a circulating protein and circulates throughout the body to remove cellular debris. The aim of this study was to evaluate the association between MSI status and AIM levels in CRC patients.

METHODS

In this study, we evaluated the levels of AIM by Enzyme Linked Immuno-Sorbent Assay (ELISA) in serum of 430 CRC patients. All patients' clinical and laboratory characteristics at initial diagnosis were collected. The relationship between AIM levels and MSI status was examined.

RESULTS

64 patients (14.9%) were identified as having MSI-H (high-frequency MSI) and 366 casess (85.1%) having MSS. Patients with an MSI-H phenotype had lower AIM levels compared with MSS patients. Moreover, AIM levels were correlated with histological type and MSI status. Logistic regression analysis revealed that decreased AIM levels were independently associated with MSI-H phenotype after adjusting confounding factors.

CONCLUSION

Reduced AIM levels are associated with MSI-H subtyping of CRC. Further research on the involvement of AIM in MSI-H CRC is needed.

Statin rosuvastatin inhibits apoptosis of human coronary artery endothelial cells through upregulation of the JAK2/STAT3 signaling pathway

The purpose of the present study was to explore the potential molecular signaling pathway mediated by the statin rosuvastatin in cultured human coronary artery endothelial cells (HCAECs) induced by CoCl2. CoCl2 was used to induce the apoptosis of HCAECs. Myocardial infarction rats were established and received statin or PBS treatment. Reverse transcription‑quantitative PCR, western blotting, ELISA, TUNEL assay and immunohistochemistry were used to analyze the role of statin treatment. The results showed that rosuvastatin treatment decreased apoptosis of HCAECs induced by CoCl2 by increasing anti‑apoptosis Bcl‑xl and Bcl‑2 expression, and decreasing pro‑apoptosis Bax, Bad, caspase‑3 and caspase‑9 expression. The myocardial ischemia rat model demonstrated that rosuvastatin treatment decreased the mitochondrial reactive oxygen species, inflammation, mitochondrial damage, lipid catabolism, heart failure and the myocardial infarction areas, but improved the cardiac function indicators, right and left ventricular ejection fraction and increased expression levels of Janus kinase (JAK) and signal transducer and activator of transcription (STAT)3 in myocardial tissue. In conclusion, the results of the current study revealed that the statin rosuvastatin presents cardioprotective effects by activation of the JAK2/STAT3 signaling pathway.

Therapeutic Targeting of Apoptosis Inhibitor of Macrophage/CD5L in Sepsis

The factors involved in disturbing host homeostasis during sepsis are largely unknown. We sought to determine the immunopathological role of apoptosis inhibitor of macrophage (AIM)/CD5L in sepsis. Here, we show that blockade of AIM led to significantly increased survival after experimental sepsis, and it decreased local and systemic inflammation, reduced tissue injury, and inhibited bacterial dissemination in the blood, in particular at later time points. Supplementation of recombinant AIM in sepsis resulted in increased tissue injury, amplified inflammation, increased bacteremia, and worsened mortality. Interestingly, the most important difference in the production of cytokines and chemokines after in vivo AIM blockade or AIM administration during sepsis was IL-10. In vitro, AIM enhanced IL-10 production from macrophages, neutrophils, or lymphocytes. In vivo, the beneficial effects of AIM blockade and the detrimental effects of AIM addition on experimental sepsis were ablated by treatment with recombinant IL-10 and neutralizing anti-IL-10 antibodies, respectively. This study is the first to identify AIM as an important mediator in disturbing host homeostasis in sepsis.

Plasma CD5L and non-invasive diagnosis of acute heart rejection

BACKGROUND

Acute rejection is one of the most important direct contributors to mortality after heart transplantation. Advances in the development of novel non-invasive approaches for the early identification of allograft rejection are necessary. We conducted a non-targeted proteome characterization focused on identifying multiple plasmatic protein differences to evaluate their diagnostic accuracy for rejection episodes.

METHODS

We included consecutive plasma samples from transplant recipients undergoing routine endomyocardial biopsies. A liquid chromatography-tandem mass spectrometry analysis using isobaric tags (tandem mass tag 10-plex) was performed and concentrations of CD5L were validated using a specific sandwich enzyme-linked immunosorbent assay.

RESULTS

A total of 17 altered proteins were identified as potential markers for detecting heart transplant rejection, most involved in inflammation and immunity. CD5L, an apoptosis inhibitor expressed by macrophages, showed the best results in the proteomic analysis (n = 30). We confirm this finding in a larger patient cohort (n = 218), obtaining a great diagnostic capacity for clinically relevant rejection (≥Grade 2R: area under the curve = 0.892, p < 0.0001) and preserving the accuracy at mild rejection (Grade 1R: area under the curve = 0.774, p < 0.0001). CD5L was a strong independent predictor, with an odds ratio of 14.74 (p < 0.0001), for the presence of rejection.

CONCLUSIONS

Episodes of acute cardiac allograft rejection are related to significant changes in a key inhibitor of apoptosis in macrophages, CD5L. Because of its precision to detect acute cellular rejection, even at mild grade, we propose CD5L as a potential candidate to be included in the studies of molecule combination panel assays. This finding could contribute to improving the diagnostic and preventive methods for the surveillance of cardiac transplanted patients.

The effect of exposure time and concentration of airborne PM2.5 on lung injury in mice: A transcriptome analysis

The association between airborne fine particulate matter (PM2.5) concentration and the risk of respiratory diseases has been well documented by epidemiological studies. However, the mechanism underlying the harmful effect of PM2.5 has not been fully understood. In this study, we exposed the C57BL/6J mice to airborne PM2.5 for 3 months (mean daily concentration ~50 or ~110 μg/m3, defined as PM2.5-3L or PM2.5-3H) or 6 months (mean daily concentration ~50 μg/m3, defined as PM2.5-6L) through a whole-body exposure system. Histological and biochemical analysis revealed that PM2.5-3H exposure caused more severe lung injury than did PM2.5-3L, and the difference was greater than that of PM2.5-6L vs PM2.5-3L exposure. With RNA-sequencing technique, we found that the lungs exposed with different concentration of PM2.5 have distinct transcriptional profiles. PM2.5-3H exposure caused more differentially expressed genes (DEGs) in lungs than did PM2.5-3L or PM2.5-6L. The DEGs induced by PM2.5-3L or PM2.5-6L exposure were mainly enriched in immune pathways, including Hematopoietic cell lineage and Cytokine-cytokine receptor interaction, while the DEGs induced by PM2.5-3H exposure were mainly enriched in cardiovascular disease pathways, including Hypertrophic cardiomyopathy and Dilated cardiomyopathy. In addition, we found that upregulation of Cd5l and reduction of Hspa1 and peroxiredoxin-4 was associated with PM2.5-induced pulmonary inflammation and oxidative stress. These results may provide new insight into the cytotoxicity mechanism of PM2.5 and help to development of new strategies to attenuate air pollution associated respiratory disease.

CD5L contributes to the pathogenesis of methicillin-resistant Staphylococcus aureus-induced pneumonia

Staphylococcus aureus is a major causative microorganism in community- and healthcare-acquired pneumonia. CD5L is an important protein in the control of immune homeostasis. In this study, we found that patients with S. aureus pneumonia displayed increased levels of circulating CD5L. Likewise, mice with S. aureus pneumonia had elevated CD5L levels in the lungs. Anti-CD5L antibody protected mice from lethal pneumonia induced by methicillin-resistant S. aureus. The survival benefit obtained with antibody against CD5L was associated with an improvement of bacterial clearance and a reduction of pulmonary inflammatory cytokines and chemokines. Conversely, co-injection of recombinant CD5L and S. aureus markedly increased the lethality of S. aureus pneumonia. These findings suggest that CD5L contributed to the immunopathology of S. aureus pneumonia.

Silk fibroin/poly(L-lactic acid-co-ε-caprolactone) electrospun nanofibrous scaffolds exert a protective effect following myocardial infarction

Electrospinning using biocompatible polymer scaffolds, seeded with or without stem cells, is considered a promising technique for producing fibrous scaffolds with therapeutic possibilities for ischemic heart disease. However, no optimal scaffolds for treating ischemic heart disease have been identified thus far. In the present study, it was evaluated whether electrospun silk fibroin (SF)-blended poly(L-lactic acid-co-ε-caprolactone) [P(LLA-CL)] scaffolds that were seeded with cluster of differentiation 117 (c-kit)⁺ bone marrow (BM) cells may serve a protective role in cardiac remodeling following myocardial infarction (MI). Mechanical characteristics and cytocompatibility were compared between SF/P(LLA-CL) and P(LLA-CL) electrospun nanofibrous scaffolds in vitro. It was observed that MI led to a significant increase of the c-kit⁺ BM cell subpopulation in mice. Magnetic activated cell sorting was performed to harvest the c-kit⁺ cell population from the BM of mice following MI. c-kit⁺ BM cells were seeded on SF/P(LLA-CL) and P(LLA-CL) electrospun nanofibrous scaffolds. Results indicated that SF/P(LLA-CL) electrospun nanofibrous scaffolds were superior to P(LLA-CL) electrospun nanofibrous scaffolds in improving c-kit⁺ BM cell proliferation. Additionally, compared with pure SF/P(LLA-CL) electrospun nanofibrous scaffolds, SF/P(LLA-CL) scaffolds seeded with c-kit⁺ BM cells resulted in lower levels of MI markers and reduced infarct size, leading to greater global heart function improvement in vivo. The findings of the present study indicated that SF/P(LLA-CL) electrospun nanofibrous scaffolds seeded with c-kit⁺ BM cells exert a protective effect against MI and may be a promising approach for cardiac regeneration after ischemic heart disease.

Down-regulation of myocardial infarction associated transcript 1 improves myocardial ischemia-reperfusion injury in aged diabetic rats by inhibition of activation of NF-κB signaling pathway

OBJECTIVE

This study is performed to investigate the effect of long chain noncoding RNA myocardial infarction associated transcript 1 (MIRT1) on myocardial ischemia reperfusion (I/R) injury in aged diabetic rats.

METHODS

The aged diabetic rat model and myocardial I/R injury model were established. Through injecting MIRT1 siRNA into caudal vein of rats, the cardiac function, myocardial pathological injury, myocardial fibrosis, cardiomyocytes apoptosis, oxidative stress and inflammatory injury of myocardial tissue of rats were measured.

RESULTS

For diabetic I/R rats, the expression of MIRT1 in myocardial tissue was increased, the activation of nuclear factor kappa B (NF-κB) signaling pathway was increased, the degree of damage to cardiac function was aggravated, the area of myocardial pathological injury and myocardial fibrosis was enlarged, the degree of cardiomyocytes apoptosis was increased, the degree of oxidative stress and inflammatory injury was increased. After inhibiting the expression of MIRT1, the activation of NF-κB signaling pathway was inhibited, the damage of cardiac function and cardiomyopathy was alleviated, the area of myocardial fibrosis was decreased, the degree of myocardial apoptosis was decreased, the degree of oxidative stress and inflammatory injury was obviously improved.

CONCLUSION

Our study highlights that down-regulation of MIRT1 improves myocardial I/R injury in aged diabetic rats by inhibition of activation of NF-κB signaling pathway.

Endothelial stem cells attenuate cardiac apoptosis via downregulating cardiac microRNA-146a in a rat model of coronary heart disease

Coronary artery disease (CAD) is one of the main causes of hospitalization worldwide and has high morbidity. It has previously been demonstrated that stem cells serve an important role in improving myocardial function. MicroRNA (miRNA)-146a downregulation has been reported to inhibit vascular smooth muscle cell apoptosis in a rat model of coronary heart disease. The aim of the present study was to investigate the mechanisms underlying the effects of endothelial stem cell (ESC)-derived paracrine factors and cardiac miRNAs in CAD. Acute myocardial infarction was induced in 20 rats. Autologous ESCs (n=10; experimental group) or PBS (n=10; control group) were injected in the border zone. Reverse transcription-quantitative polymerase chain reaction, ELISA and immunohistochemistry assays were performed to analyze the therapeutic effects of ESCs in rats with coronary heart disease rats. Serum interleukin (IL)-1, IL-17 and tumor necrosis factor-α were reduced in the experimental group compared with control rats, as was the number of circulating proatherogenic cells. The results demonstrated that ESC transplantation markedly downregulated miRNA-146a expression and decreased apoptosis in the myocardium compared with the control group. Rats in the experimental group also had higher levels of vascular endothelial growth factor compared with the control group. In addition, it was demonstrated that miRNA-146 knockdown reduced cardiac apoptosis and increased VEGF expression. Furthermore, the infarct area in the border zone or rats with CAD was reduced in the experimental group compared with the control group. In conclusion, these results suggest that ESC transplantation may improve cardiac function via downregulating miR-146a, which may be have potential as a treatment for CAD.

Elevation of serum CD5L concentration is correlated with disease activity in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is characterized by an autoantibody- and immune complex-mediated inflammatory disease. Since CD5-like (CD5L), also known as apoptosis inhibitor of macrophage (AIM), is as an apoptosis inhibitor that protects the survival of macrophages, T cells, and NKT against proapoptotic agents, which plays an important role in the pathogenesis of various inflammatory diseases, we investigated the possible aberrant production of CD5L and its clinical implications in SLE patients. We measured the serum concentration and ex vivo production of CD5L in 68 SLE patients and 60 sex- and age- matched control individuals using an enzyme-linked immunoabsorbent assay. Serum CD5L concentrations were significantly higher in SLE patients than in healthy control subjects. Increase in CD5L concentration correlated positively and significantly with SLE Disease Activity Index (SLEDAI) score in all SLE patients. Besides, CD5L titers were positively correlated with anti-double stranded DNA antibody (anti-dsDNA) titers, ESR and C-reactive protein (CRP) levels, and negatively correlated with complement 3 (C3) and C4 levels. Serum CD5L concentrations could be significantly decreased after effective treatment of SLE. In addition, the ex vivo release of CD5L upon mitogen activation of peripheral blood mononuclear cells was significantly higher in the SLE groups than in the healthy control group. The above results suggest that the up-regulated production of CD5L is important in the immunopathogenesis of SLE, and may serve as a potential disease marker for the monitoring of SLE disease severity and therapeutic efficacy.

Protein Biomarkers of Cardiovascular Disease and Mortality in the Community

BACKGROUND

The discovery of novel and highly predictive biomarkers of cardiovascular disease (CVD) has the potential to improve risk-stratification methods and may be informative regarding biological pathways contributing to disease.

METHODS AND RESULTS

We used a discovery proteomic platform that targeted high-value proteins for CVD to ascertain 85 circulating protein biomarkers in 3523 Framingham Heart Study participants (mean age, 62 years; 53% women). Using multivariable-adjusted Cox models to account for clinical variables, we found 8 biomarkers associated with incident atherosclerotic CVD, 18 with incident heart failure, 38 with all-cause mortality, and 35 with CVD death (false discovery rate, q<0.05 for all; P-value ranges, 9.8×10-34 to 3.6×10-2). Notably, a number of regulators of metabolic and adipocyte homeostasis were associated with cardiovascular events, including insulin-like growth factor 1 (IGF1), insulin-like growth factor binding protein 1 (IGFBP1), insulin-like growth factor binding protein 2 (IGFBP2), leptin, and adipsin. In a multimarker approach that accounted for clinical factors, growth differentiation factor 15 (GDF15) was associated with all outcomes. In addition, N-terminal pro-b-type natriuretic peptide, C-reactive protein, and leptin were associated with incident heart failure, and C-type lectin domain family 3 member B (CLEC3B; tetranectin), N-terminal pro-b-type natriuretic peptide, arabinogalactan protein 1 (AGP1), soluble receptor for advanced glycation end products (sRAGE), peripheral myelin protein 2 (PMP2), uncarboxylated matrix Gla protein (UCMGP), kallikrein B1 (KLKB1), IGFBP2, IGF1, leptin receptor, and cystatin-C were associated with all-cause mortality in a multimarker model.

CONCLUSIONS

We identified numerous protein biomarkers that predicted cardiovascular outcomes and all-cause mortality, including biomarkers representing regulators of metabolic homeostasis and inflammatory pathways. Further studies are needed to validate our findings and define clinical utility, with the ultimate goal of improving strategies for CVD prevention.

Myocardial infarction remodeling that progresses to heart failure: a signaling misunderstanding

After myocardial infarction, remodeling of the left ventricle involves a wound-healing orchestra involving a variety of cell types. In order for wound healing to be optimal, appropriate communication must occur; these cells all need to come in at the right time, be activated at the right time in the right amount, and know when to exit at the right time. When this occurs, a new homeostasis is obtained within the infarct, such that infarct scar size and quality are sufficient to maintain left ventricular size and shape. The ideal scenario does not always occur in reality. Often, miscommunication can occur between infarct and remote spaces, across the temporal wound-healing spectrum, and across organs. When miscommunication occurs, adverse remodeling can progress to heart failure. This review discusses current knowledge gaps and recent development of the roles of inflammation and the extracellular matrix in myocardial infarction remodeling. In particular, the macrophage is one cell type that provides direct and indirect regulation of both the inflammatory and scar-forming responses. We summarize current research efforts focused on identifying biomarker indicators that reflect the status of each component of the wound-healing process to better predict outcomes.

Liraglutide repairs the infarcted heart: The role of the SIRT1/Parkin/mitophagy pathway

Liraglutide is glucagon‑like peptide‑1 receptor agonist used for treating patients with type 2 diabetes mellitus. The present study aimed to investigate the role and mechanism of liraglutide in repairing the infarcted heart following myocardial infarction. The results of the present study demonstrated that amplification of the dose of liraglutide for ~28 days was able to reduce cardiac fibrosis, inflammatory responses and myocardial death in the post‑infarcted heart. In vitro, liraglutide protected cardiomyocyte mitochondria against the chronic hypoxic damage, inhibiting the mitochondrial apoptosis pathways. Mechanistically, liraglutide elevated the expression of NAD‑dependent protein deacetylase sirtuin‑1 (SIRT1), which increased the expression of Parkin, leading to mitophagy activation. Protective mitophagy reversed cellular adenosine 5'‑triphosphate production, reduced cellular oxidative stress and balanced the redox response, sustaining mitochondrial homeostasis. Notably, following blockade of glucagon‑like peptide 1 receptor or knockdown of Parkin, the beneficial effects of liraglutide on mitochondria disappeared. In conclusion, the results of the present study illustrated the protective role of liraglutide in repairing the infarcted heart via regulation of the SIRT1/Parkin/mitophagy pathway.

Apoptosis inhibitor of macrophage depletion decreased M1 macrophage accumulation and the incidence of cardiac rupture after myocardial infarction in mice

Background

Cardiac rupture is an important cause of death in the acute phase after myocardial infarction (MI). Macrophages play a pivotal role in cardiac remodeling after MI. Apoptosis inhibitor of macrophage (AIM) is secreted specifically by macrophages and contributes to macrophage accumulation in inflamed tissue by maintaining survival and recruiting macrophages. In this study, we evaluated the role of AIM in macrophage accumulation in the infarcted myocardium and cardiac rupture after MI.

Methods and results

Wild-type (WT) and AIM^‒/‒ mice underwent permanent left coronary artery ligation and were followed-up for 7 days. Macrophage accumulation and phenotypes (M1 pro-inflammatory macrophage or M2 anti-inflammatory macrophage) were evaluated by immunohistological analysis and RT-PCR. Matrix metalloproteinase (MMP) activity levels were measured by gelatin zymography. The survival rate was significantly higher (81.1% vs. 48.2%, P<0.05), and the cardiac rupture rate was significantly lower in AIM^‒/‒ mice than in WT mice (10.8% vs. 31.5%, P<0.05). The number of M1 macrophages and the expression levels of M1 markers (iNOS and IL-6) in the infarcted myocardium were significantly lower in AIM^‒/‒ mice than in WT mice. In contrast, there was no difference in the number of M2 macrophages and the expression of M2 markers (Arg-1, CD206 and TGF-β1) between the two groups. The ratio of apoptotic macrophages in the total macrophages was significantly higher in AIM^‒/‒ mice than in WT mice, although MCP-1 expression did not differ between the two groups. MMP-2 and 9 activity levels in the infarcted myocardium were significantly lower in AIM^‒/‒ mice than in WT mice.

Conclusions

These findings suggest that AIM depletion decreases the levels of M1 macrophages, which are a potent source of MMP-2 and 9, in the infarcted myocardium in the acute phase after MI by promoting macrophage apoptosis, and leads to a decrease in the incidence of cardiac rupture and improvements in survival rates.

Monocyte-derived alveolar macrophages drive lung fibrosis and persist in the lung over the life span

Misharin et al. elucidate the fate and function of monocyte-derived alveolar macrophages during the course of pulmonary fibrosis. These cells persisted throughout the life span, were enriched for the expression of profibrotic genes, and their genetic ablation ameliorated development of pulmonary fibrosis.

Little is known about the relative importance of monocyte and tissue-resident macrophages in the development of lung fibrosis. We show that specific genetic deletion of monocyte-derived alveolar macrophages after their recruitment to the lung ameliorated lung fibrosis, whereas tissue-resident alveolar macrophages did not contribute to fibrosis. Using transcriptomic profiling of flow-sorted cells, we found that monocyte to alveolar macrophage differentiation unfolds continuously over the course of fibrosis and its resolution. During the fibrotic phase, monocyte-derived alveolar macrophages differ significantly from tissue-resident alveolar macrophages in their expression of profibrotic genes. A population of monocyte-derived alveolar macrophages persisted in the lung for one year after the resolution of fibrosis, where they became increasingly similar to tissue-resident alveolar macrophages. Human homologues of profibrotic genes expressed by mouse monocyte-derived alveolar macrophages during fibrosis were up-regulated in human alveolar macrophages from fibrotic compared with normal lungs. Our findings suggest that selectively targeting alveolar macrophage differentiation within the lung may ameliorate fibrosis without the adverse consequences associated with global monocyte or tissue-resident alveolar macrophage depletion.

Deletion of Apoptosis Inhibitor of Macrophage (AIM)/CD5L Attenuates the Inflammatory Response and Infarct Size in Acute Myocardial Infarction

Background

An excessive inflammatory response after myocardial infarction (MI) increases myocardial injury. The toll‐like receptor (TLR)‐4 is activated by the recognition of endogenous ligands and is proinflammatory when there is myocardial tissue injury. The apoptosis inhibitor of the macrophage (AIM) is known to provoke an efflux of saturated free fatty acids (FFA) due to lipolysis, which causes inflammation via the TLR‐4 pathway. Therefore, this study investigated the hypothesis that AIM causes a proinflammatory response after MI.

Methods and Results

The left anterior descending coronary artery was ligated to induce MI in both AIM‐knockout (AIM^−/−) and wild‐type (WT) mice. After 3 days, the inflammatory response from activation of the TLR‐4/NFκB pathway was assessed, and infarct size was measured by staining with triphenyltetrazolium chloride. In addition, left ventricular remodeling was examined after 28 days. Although the area at risk was similar between AIM^−/− and WT mice, the infarct size was significantly smaller in AIM^−/− mice (P=0.02). The heart weight–to–body weight ratio and myocardial fibrosis were also decreased in the AIM^−/− mice, and the 28‐day survival rate was improved (P<0.01). With the reduction of plasma FFA in AIM^−/− mice, myocardial IRAK4 and NFκB activity were decreased (all P<0.05). Moreover, there was a reduction in myeloperoxidase activity and inducible nitric oxide synthase as part of the inflammatory response (P<0.01, P=0.03, respectively). Furthermore, NFκB DNA‐binding activation via TLR‐4, neutrophil infiltration, and inflammatory mediators were decreased in AIM^−/− mice.

Conclusions

The deletion of AIM reduced the inflammatory response and infarct size and improved survival after myocardial infarction.