Calpain: The regulatory point of cardiovascular and cerebrovascular diseases

Calpain, a key member of the Calpain cysteine protease superfamily, performs limited protein hydrolysis in a calcium-dependent manner. Its activity is tightly regulated due to the potential for non-specific cleavage of various intracellular proteins upon aberrant activation. A thorough review of the literature from 2010 to 2023 reveals 121 references discussing cardiovascular and cerebrovascular diseases. Dysregulation of the Calpain system is associated with various pathological phenomena, including lipid metabolism disorders, inflammation, apoptosis, and excitotoxicity. Although recent studies have revealed the significant role of Calpain in cardiovascular and cerebrovascular diseases, the precise mechanisms remain incompletely understood. Exploring the potential of Calpain inhibition as a therapeutic approach for the treatment of cardiovascular and cerebrovascular diseases may emerge as a compelling area of interest for future calpain research.

Development of a new experimental NMR strategy for covalent cysteine protease inhibitors screening: toward enhanced drug discovery

In the development of antiviral drugs, proteases and polymerases are among the most important targets. Cysteine proteases, also known as thiol proteases, catalyze the degradation of proteins by cleaving peptide bonds using the nucleophilic thiol group of cysteine. As part of our research, we are examining how cysteine, an essential amino acid found in the active site of the main protease (Mpro) enzyme in SARS-CoV-2, interacts with electrophilic groups present in ethacrynic acid (EA) and compounds 4, 6, and 8 to form sulfur-carbon bonds. Nuclear magnetic resonance (NMR) spectroscopy was used to monitor the reaction rate between cysteine and Michael acceptors. We found that the inhibitory activity of these compounds towards Mpro is correlated to their chemical reactivity toward cysteine. This approach may serve as a valuable tool in drug development for detecting potential covalent inhibitors of Mpro and other cysteine proteases.

Association between the C-reactive protein-triglyceride glucose index and erectile dysfunction in US males: results from NHANES 2001-2004

The C-reactive protein-triglyceride glucose index (CTI) is emerging as a novel indicator for comprehensively assessing the severity of both inflammation and insulin resistance. However, the association between CTI and erectile dysfunction (ED) remains largely unexplored. Participant data for this study were sourced from NHANES 2001-2004, with exclusion criteria applied to those lacking information on clinical variables. The CTI was defined as 0.412*Ln (CRP) + ln [T.G. (mg/dL) × FPG (mg/dL)/2]. Weighted univariable and multivariable logistic regression models were utilized to examine the correlation between the CTI and ED, assessing the CTI as both a continuous and categorical variable (quartile). Moreover, subgroup analyses were conducted to pinpoint sensitive populations, and interaction analysis was performed to validate the findings. A total of 1502 participants were included in the final analysis, encompassing 302 with ED and 1200 without ED. After adjusting for potential confounders, the CTI was positively associated with ED incidence (OR = 1.56, 95% CI: 1.27-1.90, P = 0.002). The fourth quartile of the CTI significantly increased the incidence of ED (OR = 2.69, 95% CI: 1.07-6.74, P = 0.04), and the lowest quartile of CTI was used as the reference. The dose-response curve revealed a positive linear relationship between the CTI and the incidence of ED. Subgroup analysis confirmed the consistent positive relationship between the CTI and ED. The interaction test indicated no significant impact on this association. Finally, a sensitivity analysis was performed to verify the significant positive correlation between the CTI and severe ED (OR = 1.44, 95% CI: 1.19-1.76, P = 0.004). Our national data indicate that a greater CTI is positively linked to an increased risk of ED in US men, suggesting its potential for use in clinical practice for ED prevention or early intervention. Additional large-scale prospective studies are warranted to substantiate the causative relationship between CTI and ED.

Ginsenoside Rg1 alleviates vascular remodeling in hypoxia-induced pulmonary hypertension mice through the calpain-1/STAT3 signaling pathway

Background

Hypoxic pulmonary hypertension (HPH) is the main pathological change in vascular remodeling, a complex cardiopulmonary disease caused by hypoxia. Some research results have shown that ginsenoside Rg1 (Rg1) can improve vascular remodeling, but the effect and mechanism of Rg1 on hypoxia-induced pulmonary hypertension are not clear. The purpose of this study was to discuss the potential mechanism of action of Rg1 on HPH.

Methods

C57BL/6 mice, calpain-1 knockout mice and Pulmonary artery smooth muscle cells (PASMCs) were exposed to a low oxygen environment with or without different treatments. The effect of Rg1 and calpain-1 silencing on inflammation, fibrosis, proliferation and the protein expression levels of calpain-1, STAT3 and p-STAT3 were determined at the animal and cellular levels.

Results

At the mouse and cellular levels, hypoxia promotes inflammation, fibrosis, and cell proliferation, and the expression of calpain-1 and p-STAT3 is also increased. Ginsenoside Rg1 administration and calpain-1 knockdown, MDL-28170, and HY-13818 treatment showed protective effects on hypoxia-induced inflammation, fibrosis, and cell proliferation, which may be associated with the downregulation of calpain-1 and p-STAT3 expression in mice and cells. In addition, overexpression of calpain 1 increased p-STAT3 expression, accelerating the onset of inflammation, fibrosis and cell proliferation in hypoxic PASMCs.

Conclusion

Ginsenoside Rg1 may ameliorate hypoxia-induced pulmonary vascular remodeling by suppressing the calpain-1/STAT3 signaling pathway.

CAPN5 attenuates cigarette smoke extract-induced apoptosis and inflammation in BEAS-2B cells

INTRODUCTION

Apoptosis and chronic inflammation are the main phenotypes in chronic obstructive pulmonary disease (COPD) pathogenesis. Cigarette smoke exposure is the leading risk factor for COPD, which causes aberrant airway epithelial structure and function. As a non-classical calpain, the molecular function of calpain5 (CAPN5) in COPD remains unclear. This study investigated the role of CAPN5 in mediating cigarette smoke extract (CSE)-induced apoptosis and inflammation.

METHODS

Immunohistochemistry (IHC) and Western blotting (WB) were performed to detect the location and expression of CAPN5. In vitro, BEAS-2B cells were transfected with CAPN5 siRNA or CAPN5 plasmid, followed by phosphate-buffered saline (PBS) or cigarette smoke extract (CSE) treatment. The protein expression levels of CAPN5, NF-κB p65, p-p65, IκBα, p-IκBα and apoptosis proteins (BCL-2, BAX) were measured by WB. Flow cytometry (FCM) was performed to analyze the cell apoptosis index.

RESULTS

CAPN5 was mainly expressed in the airway epithelium and significantly decreased in the COPD-smoker and emphysema-mouse groups. Silencing CAPN5 significantly decreased the protein expression of BCL-2, IκBα, and increased p-p65 and BAX protein expression. Additionally, an increased apoptosis index was detected after silencing CAPN5. Moreover, overexpression of CAPN5 partly inhibited IκBα degradation and p65 activation, and reduced CSE-induced inflammation and apoptosis.

CONCLUSIONS

These combined results indicate that CAPN5 could protect against CSE-induced apoptosis and inflammation, which may provide a potential therapeutic target for smoking-related COPD.

Calpain and Cardiometabolic Diseases

Calpain is defined as a member of the superfamily of cysteine proteases possessing the CysPC motif within the gene. Calpain-1 and -2, which are categorized as conventional isozymes, execute limited proteolysis in a calcium-dependent fashion. Accordingly, the calpain system participates in physiological and pathological phenomena, including cell migration, apoptosis, and synaptic plasticity. Recent investigations have unveiled the contributions of both conventional and unconventional calpains to the pathogenesis of cardiometabolic disorders. In the context of atherosclerosis, overactivation of conventional calpain attenuates the barrier function of vascular endothelial cells and decreases the immunosuppressive effects attributed to lymphatic endothelial cells. In addition, calpain-6 induces aberrant mRNA splicing in macrophages, conferring atheroprone properties. In terms of diabetes, polymorphisms of the calpain-10 gene can modify insulin secretion and glucose disposal. Moreover, conventional calpain reportedly participates in amino acid production from vascular endothelial cells to induce alteration of amino acid composition in the liver microenvironment, thereby facilitating steatohepatitis. Such multifaceted functionality of calpain underscores its potential as a promising candidate for pharmaceutical targets for the treatment of cardiometabolic diseases. Consequently, the present review highlights the pivotal role of calpains in the complications of cardiometabolic diseases and embarks upon a characterization of calpains as molecular targets.

Toll-like receptor 4: A potential therapeutic target for multiple human diseases

The immune response plays a pivotal role in the pathogenesis of diseases. Toll-like receptor 4 (TLR4), as an intrinsic immune receptor, exhibits widespread in vivo expression and its dysregulation significantly contributes to the onset of various diseases, encompassing cardiovascular disorders, neoplastic conditions, and inflammatory ailments. This comprehensive review centers on elucidating the architectural and distributive characteristics of TLR4, its conventional signaling pathways, and its mode of action in diverse disease contexts. Ultimately, this review aims to propose novel avenues and therapeutic targets for clinical intervention.

Inhibiting P2Y12 receptor relieves LPS-induced inflammation and endothelial dysfunction

BACKGROUND

Acute lung injury (ALI) is characterized by abnormal inflammatory response without effective therapies. P2Y12 receptor (P2Y12R) plays a vital role in inflammatory response. This study intends to explore whether P2Y12R antagonists can inhibit LPS-induced inflammatory injury of human pulmonary microvascular endothelial cells (HPMVECs) and endothelial cell dysfunction.

METHODS

Using a cell model of ALI, the role of P2Y12R was investigated in LPS-induced HPMVECs. The expression of P2Y12R was detected by RT-qPCR and Western blot analysis assay and TNF-α, IL-1β, and IL-6 levels were analyzed by RT-qPCR. NO levels were also analyzed through NO kit. The levels of NF-κB p65, P-IκB-α, and IκB-α, as well as p-AKT and eNOS levels were detected by Western blot analysis assay. Wound healing assay was performed to evaluate HPMVECs migration. FITC-dextran was used to evaluate endothelial cell permeability, and the analysis of adherens junction protein VE-cadherin and endothelial cell tight junction proteins ZO-1, Claudin 5 and Occludin expression was performed by RT-qPCR and Western blot analysis assay.

RESULTS

In vitro, LPS increased the expression levels of P2Y12R and pro-inflammatory mediators (TNF-α, IL-1β, and IL-6), followed by a decrease in HPMVECs migration. In addition, LPS led to an increase in endothelial cell permeability. P2Y12R antagonists Ticagrelor or clopidogrel treatment significantly reversed these effects of LPS.

CONCLUSION

The inhibitor of P2Y12R was able to decrease inflammatory response, promote migration and improve endothelial cell function and permeability, suggesting a key role of P2Y12R in ALI.

Efficacy of leupeptin in treating ischemia in a rat hind limb model

Prolonged tourniquet use can lead to tissue ischemia and can cause progressive muscle and nerve injuries. Such injuries are accompanied by calpain activation and subsequent Wallerian-like degeneration. Several known inhibitors, including leupeptin, are known to impede the activity of calpain and associated tissue damage. We hypothesize that employment of leupeptin in a rat model of prolonged hind limb ischemia can mitigate muscle and nerve injuries. Sprague-Dawley rats (n = 10) weighing between 300-400 g were employed in this study. Their left hind limbs were subjected to blood flow occlusion for a period of 2-h using a neonatal blood pressure cuff. Five rats were given twice weekly intramuscular leupeptin injections, while the other five received saline. After 2 weeks, the animals were euthanized, their sciatic nerves and gastrocnemius muscles were harvested, fixed, stained, and analyzed using NIH Image J software. The administration of leupeptin resulted in larger gastrocnemius muscle fiber cross-sectional areas for the right (non-tourniquet applied) hindlimb as compared to that treated with the saline (p = 0.0110). However, no statistically significant differences were found between these two groups for the injured left hindlimb (p = 0.1440). With regards to the sciatic nerve cross-sectional areas and sciatic functional index, no differences were detected between the leupeptin and control treated groups for both the healthy and injured hindlimbs. This research provides new insights on how to employ leupeptin to inhibit the degenerative effects of calpain and preserve tissues following ischemia resulting from orthopedic or plastic surgery procedures.

Calpain inhibitor prevents atherosclerosis in apolipoprotein E knockout mice by regulating mRNA expression of genes related to cholesterol uptake and efflux

PURPOSE

We previously reported that a calpain inhibitor (CAI) prevents the development of atherosclerosis in rats. This study aimed to investigate the effects of CAI (1 mg/kg) on atherosclerosis in apolipoprotein E knockout (ApoE KO) mice that were fed a high-fat diet (HFD) and explore the underlying mechanism by analyzing the expression of genes related to the uptake and efflux of cholesterol.

METHODS

Atherosclerotic plaques were evaluated. The activity of calpain in the aorta and that of superoxide dismutase (SOD) in the serum were assessed. Lipid profiles in the serum and liver were examined. Serum oxidized low-density lipoprotein (oxLDL), malondialdehyde (MDA), tumor necrosis factor (TNF-α), and interleukin-6 (IL-6) levels were measured. The mRNA expressions of CD68, TNF-α, IL-6, CD36, scavenger receptor (SR-A), peroxisome proliferator-activated receptor gamma (PPAR-γ), liver-x-receptor alpha (LXR-α), and ATP-binding cassette transporter class A1 (ABCA1) in the aorta and peritoneal macrophages were also evaluated.

RESULTS

CAI reduced calpain activity in the aorta. CAI also impeded atherosclerotic lesion formation and mRNA expression of CD68 in the aorta and peritoneal macrophages of ApoE KO mice compared with those of mice receiving HFD. However, CAI had no effect on body weight and lipid levels in both the serum and liver. CAI significantly decreased MDA, oxLDL, TNF-α, and IL-6 levels and increased SOD activity in the serum. Moreover, CAI significantly inhibited the mRNA expression of TNF-α and IL-6 genes in the aorta and peritoneal macrophages. In addition, CAI significantly downregulated the mRNA expression of scavenger receptors CD36 and SR-A and upregulated the expression of genes involved in the cholesterol efflux pathway, i.e., PPAR-γ, LXR-α, and ABCA1 in the aorta and peritoneal macrophages.

CONCLUSIONS

CAI inhibited the development of atherosclerotic lesions in ApoE KO mice, and this effect might be related to the reduction of oxidative stress and inflammation and the improvement of cholesterol intake and efflux pathways.

PAR-4/Ca2+-calpain pathway activation stimulates platelet-derived microparticles in hyperglycemic type 2 diabetes

Background

Patients with type 2 diabetes (T2DM) have a prothrombotic state that needs to be fully clarified; microparticles (MPs) have emerged as mediators and markers of this condition. Thus, we investigate, in vivo, in T2DM either with good (HbA1c ≤ 7.0%; GGC) or poor (HbA1c > 7.0%; PGC) glycemic control, the circulating levels of MPs, and in vitro, the molecular pathways involved in the release of MPs from platelets (PMP) and tested their pro-inflammatory effects on THP-1 transformed macrophages.

Methods

In 59 T2DM, and 23 control subjects with normal glucose tolerance (NGT), circulating levels of CD62E+, CD62P+, CD142+, CD45+ MPs were determined by flow cytometry, while plasma levels of ICAM-1, VCAM-1, IL-6 by ELISA. In vitro, PMP release and activation of isolated platelets from GGC and PGC were investigated, along with their effect on IL-6 secretion in THP-1 transformed macrophages.

Results

We found that MPs CD62P⁺ (PMP) and CD142⁺ (tissue factor-bearing MP) were significantly higher in PGC T2DM than GGC T2DM and NGT. Among MPs, PMP were also correlated with HbA1c and IL-6. In vitro, we showed that acute thrombin exposure stimulated a significantly higher PMP release in PGC T2DM than GGC T2DM through a more robust activation of PAR-4 receptor than PAR-1 receptor. Treatment with PAR-4 agonist induced an increased release of PMP in PGC with a Ca²⁺-calpain dependent mechanism since this effect was blunted by calpain inhibitor. Finally, the uptake of PMP derived from PAR-4 treated PGC platelets into THP-1 transformed macrophages promoted a marked increase of IL-6 release compared to PMP derived from GGC through the activation of the NF-kB pathway.

Conclusions

These results identify PAR-4 as a mediator of platelet activation, microparticle release, and inflammation, in poorly controlled T2DM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01267-w.

MAPK/iNOS pathway is involved in swine kidney necrosis caused by cadmium exposure

Cadmium (Cd) pollution in the environment could cause toxic damage to animals and humans. MAPK pathways could regulate their downstream inflammatory factors, and plays a crucial role in necrosis. Since the swine kidney tissue is an important accumulation site of Cd and target organ of its toxic damage, but the damage form of Cd to swine kidney and the role of MAPK pathways in it are still not clear, we selected six week old weaned piglets as the research object, and fed a diet supplemented CdCl₂ (20 mg/kg) to establish the model of liver injury induced by Cd. The expressions and phosphorylation of MAPK pathways (ERK, JNK, p38), expression levels of inflammatory factors (TNF-α, NF-κB, iNOS, COX-2 and PTGE) and necrosis related genes (MLKL, RIPK1, RIPK3 and FADD) and heat shock proteins (HSPs) were detected by RT-PCR and Western blot. H.E. staining was used to determine the damage of kidney caused by Cd exposure. The results showed that Cd exposure could activate p38 and JNK pathway phosphorylation, rather than ERK 1/2, up regulated the expressions of inflammatory factors, finally induced programmed necrosis (increasing the expressions of MLKL, RIPK1, RIPK3 and FADD) in swine kidney. Our study elucidated the mechanism of Cd-damage to swine kidney and the relationship among MAPK pathways, inflammatory factors and programmed necrosis in swine.

High Plasma Levels of Soluble Talin-1 in Patients with Coronary Artery Disease

Aims

Talin-1 is a cytoskeletal protein that binds integrin, thereby leading to integrin activation and affecting focal adhesions. Recently, talin-1 expression was reported to be downregulated in human atherosclerotic plaques. However, blood levels of soluble talin-1 (sTalin-1) in patients with atherosclerotic disease, such as coronary artery disease (CAD), have not been elucidated.

Methods

We measured plasma sTalin-1 levels in 349 patients undergoing elective coronary angiography. The severity of CAD was represented as the number of stenotic coronary vessels and segments.

Results

Of the 349 study patients, CAD was found in 194 patients, of whom 88 had 1-vessel disease (1-VD), 60 had 2-vessel disease (2-VD), and 46 had 3-vessel disease (3-VD). Plasma sTalin-1 levels were higher in 194 patients with CAD than in 155 without CAD (CAD(-) group) (median 0.30 vs. 0.23 ng/mL, P < 0.005). A stepwise increase in sTalin-1 levels was found depending on the number of >50% stenotic coronary vessels: 0.23 in CAD(-), 0.29 in 1-VD, 0.30 in 2-VD, and 0.32 ng/mL in 3-VD group, respectively, (P < 0.05). High sTalin-1 level (>0.28 ng/mL) was found in 36% of CAD(-), 51% of 1-VD, 53% of 2-VD, and 59% of 3-VD group (P < 0.025). sTalin-1 levels also correlated with the number of >50% stenotic segments (r = 0.14, P < 0.02). The multivariate analysis revealed that sTalin-1 levels were independently associated with CAD. The odds ratio for CAD was 1.83 (95%CI = 1.14 - 2.93) for high sTalin-1 level (>0.28 ng/mL) (P < 0.02).

Conclusions

Plasma sTalin-1 levels in patients with CAD were found to be high and to be associated with the presence and severity of CAD, suggesting a role of sTalin-1 in the progression of coronary atherosclerosis.

The identification and function of a Netrin-1 mutation in a pedigree with premature atherosclerosis

BACKGROUND AND AIMS

Neuroimmune guidance cues have been shown to play a role in atherosclerosis, but their exact role in human pathophysiology is largely unknown. In the current study, we investigated the role of a c.1769G > T variant in Netrin-1 in (premature) atherosclerosis.

METHODS

To determine the effect of the genetic variation, purified Netrin-1, either wild type (wtNetrin-1) or the patient observed variation (mutNetrin-1), was used for migration, adhesion, endothelial barrier function and bindings assays. Expression of adhesion molecules and transcription proteins was analyzed by RT-PCR, Western blot or ELISA. To further delineate how mutNetrin-1 mediates its effect on cell migration, lenti-viral knockdown of UNC5B or DCC was used.

RESULTS

Bindings assays revealed a decreased binding capacity of mutNetrin-1 to the receptors UNC5B, DCC and β3-integrin and an increased binding capacity to neogenin, heparin and heparan sulfate compared to wtNetrin-1. Exposure of endothelial cells to mutNetrin-1 resulted in enhanced monocyte adhesion and expression of IL-6, CCL2 and ICAM-1 compared to wtNetrin-1. In addition, mutNetrin-1 lacks the inhibitory effect on the NF-κB pathway that is observed for wtNetrin-1. Moreover, the presence of mutNetrin-1 diminished migration of macrophages and smooth muscle cells. Importantly, UNC5B or DCC specific knockdown showed that mutNetrin-1 is unable to act through DCC resulting in enhanced inhibition of migration.

CONCLUSIONS

Our data demonstrates that mutNetrin-1 fails to exert anti-inflammatory effects on endothelial cells and more strongly blocks macrophage migration compared to wtNetrin-1, suggesting that the carriers of this genetic molecular variant may well be at risk for premature atherosclerosis.

Retinoic acid attenuates cardiac injury induced by hyperglycemia in pre- and post-delivery mice

The aim of the present study is to explore the effect of retinoic acid (RA) on cardiac injury induced by gestational diabetes mellitus (GDM). GDM mice were given 3 mg/kg RA once daily until the 19th day of pregnancy or the 7th day of post-partum. Compared to normal control and normal pregnant control mice, GDM mice before and after delivery showed significantly cardiac injury. RA treatment attenuated cardiac injury as evidenced by decreased heart mass and left ventricular mass, mRNA expressions of ANP and BNP, and cardiac fibrosis compared with that in GDM mice. The protective effect of RA on GDM cardiomyopathy was related to the decreased MDA content and ROS generation, the increased GSH-Px and SOD content as well as the reduced TNF-α and IL-1β content and inhibition of NF-κB signaling. In addition, RA treatment delayed the continuous rise of blood glucose before delivery and decreased the higher level of glucose after delivery. In conclusion, RA treatment could increase the activity of the antioxidant enzyme and suppress the oxidative stress, inflammation response, and activation of NF-κB signaling, thereby improving blood glucose level and cardiac injury of GDM mice before and after delivery.

Lycium barbarum polysaccharide attenuates cardiac hypertrophy, inhibits calpain-1 expression and inhibits NF-κB activation in streptozotocin-induced diabetic rats

Cardiac hypertrophy is one of the key structural changes that occurs in diabetic cardiomyopathy. Previous studies have indicated that the activation of NF-κB by calpain-1, a Ca²⁺-dependent cysteine protease, serves an important role in cardiac hypertrophy. The aim of the present study was to assess the effect of 30 and 60 mg/kg Lycium barbarum polysaccharide (LBP) treatment, the major active ingredient extracted from Lycium barbarum, on cardiac hypertrophy in streptozotocin (STZ) induced diabetic rats. In addition, the present study examined the possible underlying mechanisms of this effect by assessing calpain-1 expression and the NF-κB pathway. The mRNA expression of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) was determined by reverse transcription-quantitative PCR. Western blotting was used to detect the protein expressions of calpain-1, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1) and toll-like receptor-4 (TLR-4) in the heart tissue. The results revealed that compared with non-diabetic rats, diabetic rats exhibited cardiac hypertrophy. Cardiac hypertrophy was defined by the following: Dysfunction of the cardiac hemodynamics, an increase in the ratios of left ventricular weight/body weight and heart weight/body weight and the increased expressions of ANP and BNP, which serve as hypertrophic markers in cardiac tissue. However, all of these changes were attenuated in diabetic rats treated with LBP. In addition, the protein expression of calpain-1 was increased in the heart tissue of diabetic rats compared with that of non-diabetic rats, where it was inhibited by LBP. LBP also decreased the protein expression of certain inflammatory mediators, IL-6, TNF-α, ICAM-1, VCAM-1 and TLR-4 in diabetic heart tissue. Furthermore, LBP treatment reduced the production of reactive oxygen species, upregulated the protein expression of endothelial nitric oxide synthase and downregulated the protein expression of inducible nitric-oxide synthase. Additionally, LBP increased the protein expression of p65, the subunit of NF-κB and inhibitory protein кB-α in the cytoplasm and reduced p65 expression in the nucleus. In conclusion, LBP improves cardiac hypertrophy, inhibits the expression of calpain-1 and inhibits the activation of NF-κB in diabetic rats.

Simvastatin Improves Cardiac Hypertrophy in Diabetic Rats by Attenuation of Oxidative Stress and Inflammation Induced by Calpain-1-Mediated Activation of Nuclear Factor-κB (NF-κB)

BACKGROUND Simvastatin, an HMG-CoA reductase inhibitor, has been reported to exert multiple protective effects on the cardiovascular system. However, the molecular mechanism remains to be examined. The present study was designed to study the effects of simvastatin on cardiac hypertrophy in diabetic rats and to explore its potential mechanism. MATERIAL AND METHODS Sprague-Dawley rats were assigned into a control (Con) group, a streptozotocin (STZ) group, and a STZ+simvastatin (STZ+SIM) group. The level of reactive oxygen species (ROS) was measured by using dihydroethidium (DHE) staining. The protein expressions of p65, IκBα, vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), calpain-1, and endothelial nitric oxide synthase (eNOS) were examined by Western blot analysis. qPCR was used to detect the levels of brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP). RESULTS Simvastatin improved the cardiac hypertrophy of diabetic rats, as demonstrated by decreases in the ratios of left ventricular weight/body weight (LVW/BW) and heart weight/body weight (HW/BW) and by the downregulation of mRNA expression of BNP and ANP in the heart tissue. Simvastatin decreased the protein expressions of VCAM-1, ICAM-1, IL-6, and TNF-α, increased eNOS protein expression, and limited an increase in ROS levels in the heart tissue. Simvastatin increased IkBa protein expression in cytoplasm and inhibited the translocation of p65, the subunit of nuclear factor-κB (NF-κB) to the nucleus from the cytoplasm of the heart tissue. Furthermore, simvastatin attenuated the activity of calpain and calpain-1 protein expression in heart tissue. CONCLUSIONS Simvastatin attenuates cardiac hypertrophy in diabetic rats, which might be due to the attenuation of oxidative stress and inflammation induced by calpain-1-mediated activation of NF-κB.

Netrin-1 prevents the attachment of monocytes to endothelial cells via an anti-inflammatory effect

Netrin-1 is best known for its function guiding axon growth and migration. Netrin-1 has been shown to be involved in regulating cardiovascular function. In this study, we aimed to understand the biological role of Netrin-1 and its receptor Unc5b in endothelial cells. Our results demonstrate that Unc5b was moderately expressed in human aortic endothelial cells (HAECs) and TNF-α had a dose-dependent inhibitory effect on Unc5b level. Netrin-1 potently suppressed TNF-α-induced vascular adhesion molecules VCAM-1, ICAM-1, E-selectin and blocked the adhesion of monocytes to endothelial cells. Netrin-1 also suppressed TNF-α-induced production of cytokines including MCP-1, IL-1β, and IL-6. Importantly, Netrin-1 suppressed toll like receptor 4 (TLR4) expression and prevented NF-κB activation. Mechanistically, Netrin-1 reduced TNF-α-induced IKK and IκBα activation and prevented degradation of IκBα. Netrin-1 reduced nuclear accumulation of p65 and strongly suppressed NF-κB promoter activation. Collectively, our data demonstrated that signaling of Netrin-1 and its receptor Unc5b had an anti-inflammatory effect in endothelial cells. Netrin-1 signaling could be imperative for normal endothelial function.

Cardiovascular oncology: exploring the effects of targeted cancer therapies on atherosclerosis

PURPOSE OF REVIEW

Targeted cancer therapies have revolutionized the treatment of cancer in the past decade, but cardiovascular toxicity is a rising problem in cancer patients. Here we discuss the effects of targeted cancer therapies on atherosclerosis. Increasing the awareness of these adverse effects will promote the development of evidence-based preventive strategies in the emerging field of cardiovascular oncology.

RECENT FINDINGS

Vascular endothelial growth factor inhibitors, immunomodulatory imide drugs, tyrosine kinase inhibitors and immune checkpoint inhibitors are successfully used as treatment for many types of solid and hematologic malignancies. However, clinical and experimental studies have demonstrated that these drugs can drive atherosclerosis, thereby causing adverse cardiovascular events such as myocardial infarction, stroke and peripheral arterial occlusive diseases.

SUMMARY

In this review, we discuss how on-target and off-target effects of novel cancer drugs may affect atherosclerosis and we postulate how these cardiovascular adverse events can be prevented in the future.

Visceral adipose tissue-derived serine protease inhibitor accelerates cholesterol efflux by up-regulating ABCA1 expression via the NF-κB/miR-33a pathway in THP-1 macropahge-derived foam cells

Atherosclerosis is a dyslipidemia disease characterized by foam cell formation driven by the accumulation of lipids. Visceral adipose tissue-derived serine protease inhibitor (vaspin) is known to suppress the development of atherosclerosis via its anti-inflammatory properties, but it is not yet known whether vaspin affects cholesterol efflux in THP-1 macrophage-derived foam cells. Here, we investigated the effects of vaspin on ABCA1 expression and cholesterol efflux, and further explored the underlying mechanism. We found that vaspin decreased miR-33a levels, which in turn increased ABCA1 expression and cholesteorl efflux. We also found that inhibition of NF-κB reduced miR-33a expression and vaspin suppressed LPS-mediated NF-κB phosphorylation. Our findings suggest that vaspin is not only a regular of inflammasion but also a promoter of cholesterol efflux.

Defective Protein Catabolism in Atherosclerotic Vascular Inflammation

Vascular inflammation in atheroprone vessels propagates throughout the arterial tree in dyslipidemic patients, thereby accelerating atherosclerotic progression. To elucidate the mechanism of vascular inflammation, most previous studies have focused on inflammation-related signals that are sent in response to vasoactive stimuli. However, it is also important to understand how normal blood vessels become defective and start degenerating. Growing evidence suggests that major protein catabolism pathways, including the ubiquitin-proteasome, autophagy, and calpain systems, are disturbed in atheroprone vessels and contribute to the pathogenesis of atherosclerosis. Indeed, dysregulation of ubiquitin-proteasome pathways results in the accumulation of defective proteins in blood vessels, leading to vascular endothelial dysfunction and apoptosis in affected cells. Impaired autophagy-lysosomal degradation affects smooth muscle cell transformation and proliferation, as well as endothelial integrity and phagocytic clearance of cellular corpses. Dysregulation of the calpain system confers proatherogenic properties to endothelial cells, smooth muscle cells, and macrophages. In this review article, we will discuss the current information available on defective protein catabolism in atheroprone vessels and its potential interrelation with inflammation-related signals.