Pravastatin activates activator protein 2 alpha to augment the angiotensin II-induced abdominal aortic aneurysms

Citronellal can alleviate vascular endothelial dysfunction by reducing ectopic miR-133a expression

AIMS

Endothelial dysfunction (ED) is the initial cause of atherosclerosis (AS) and an early marker of many cardiovascular diseases (CVD). Citronellal (CT), a monoterpenoid natural product extracted from grass plant Citronella, has been shown to have anti-thrombotic, anti-hypertensive and anti-diabetic cardiomyopathy activities. The aim of this study is to investigate the effects of citronellal on vascular endothelial dysfunction and the underlying mechanisms.

MATERIALS AND METHODS

The left common carotid artery was subjected to one-time balloon injury to cause vascular endothelial injury, and the AS model was established by feeding with high-fat diet. Use of HUVECs H2O2 treatment induced HUVECs oxidative stress damage model. The blood lipid level, histopathology, Western blot, immunohistochemistry, RT-PCR, ELISA and in situ fluorescence hybridization of common carotid artery tissues and HUVECs were studied.

KEY FINDINGS

CT significantly reduced vascular plate area and endothelial lipid and cholesterol deposition in the common carotid artery of mice in a dose-dependent manner. CT increased the expression of activated protein 2α (AP-2α/TFAP2A) and circRNA_102979, and inhibited the ectopic expression level of miR-133a. However, the constructed lentivirus with AP-2α silencing and circRNA_102979 silencing reversed this phenomenon.

SIGNIFICANCE

The current study verifies CT can increase the expression levels of AP-2α and circRNA_102979 in vascular endothelium, increase the adsorption effect of circRNA_102979 on miR-133a and relieve the inhibitory effect of miR-133a on target genes, thereby alleviating AS-induced ED.

Effect of statins on abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a prevalent condition which causes progressive growth and rupture of aortic wall with a high death rate. Several studies have found that treatment with statins may decrease the progress of AAA and the risk of rupture by suppressing the inflammatory mediators, decreasing oxidative stress, and inhibiting mechanisms involved in extracellular matrix (ECM) degradation. Moreover, some studies have reported that prehospital therapy with statins can decrease mortality after surgery. The novelty of this paper is that different studies including those performed in humans and animals were reviewed and the potential mechanisms by which statins can have an effect on AAA were summarized. Overall, the evidence suggested an association between treatment with statins and improvement of AAA.

Targeting autophagy in aortic aneurysm and dissection

Autophagy is a well-conserved biological process that maintains homeostasis. Accumulating evidence has revealed that autophagy plays an important role in various cardiovascular diseases, such as aneurysm, aortic dissection, atherosclerosis, and myocardial ischemia-reperfusion injury. Here, we summarize the current experimental evidence on the function of autophagy and autophagy proteins in aortic aneurysm and dissection (AAD). AAD is a very serious aortic disease, and there are currently no effective drug treatment options. Studies have shown that autophagy is activated during AAD. However, the role of autophagy in AAD is still controversial. For example, knocking out autophagy related 5 (ATG5) or ATG7 to inhibit autophagy and excessive autophagy activation can promote the occurrence of AAD. Recently, multiple studies have demonstrated that rapamycin and metformin, which are autophagy activators, can delay the progression of AAD. Thus, targeting autophagy has the potential to become a new therapeutic strategy for AAD. In addition, we discuss the recent research progress on AAD from the perspective of single-cell RNA sequencing. Moreover, we offer our perspective on current challenges and barriers in this research field.

Vitamin B6 Alleviates Lipopolysaccharide-induced Myocardial Injury by Ferroptosis and Apoptosis Regulation

Vitamin B6 (VitB6) is a water-soluble vitamin and includes pyridoxine, pyridoxal, pyridoxamine, and their phosphorylated forms. In the current study, we demonstrated that VitB6 could improve lipopolysaccharide (LPS)-induced myocardial injury. We demonstrated that VitB6 can suppress LPS-induced oxidative stress and lipid peroxidation that lead to ferroptosis and apoptosis in vivo and in vitro. Moreover, we found that VitB6 can regulate the expression of iron regulatory proteins, maintaining intracellular iron homeostasis. To confirm that VitB6 could inhibit LPS-induced ferroptosis and apoptosis, we pretreated mice with ferrostatin-1 (Fer-1) and emricasan that efficiently mimicked VitB6 pharmacological effects. This improved the survival rate of mice challenged with a high LPS dose. In addition, VitB6 regulated the expression of LPS-induced apoptosis-related proteins and iron regulatory proteins. It mediated the expression of Nrf2, transcription factor NF-E2-related factor 2, which promoted the expression of antioxidant enzymes and restrained LPS-induced ferroptosis and apoptosis. Overall, our results indicated that VitB6 can be used on novel therapies to relieve LPS-induced myocardial injury.

Expression of MicroRNA-1281, C-Reactive Protein, and Renal Function in Individuals with Abdominal Aortic Aneurysm and their Clinical Correlation after Endovascular Repair

Introduction:

The treatment of infrarenal aortic aneurysms has changed in the last three decades. Endovascular aneurysm repair (EVAR) has become the primary treatment option in anatomically suitable patients with infrarenal aortic aneurysms. However, there is no serum biomarker to be used in EVAR follow-up.

Methods:

This is a prospective single-centre study of 30 consecutive patients with abdominal aortic aneurysm (AAA) who underwent EVAR. Serum dosages of micro ribonucleic acid 1281 (miRNA-1281), creatinine, total cholesterol, triglycerides, and C-reactive protein (CRP) were evaluated and angiotomographic evaluations were performed preoperatively and six months after the intervention.

Results:

There was a hyperexpression of miRNA-1281 in patients with AAA and a significant reduction of it after EVAR, from 1.66-fold before EVAR to 0.27 after the procedure (P<0.0001). MiRNA-1281 expression was not influenced by renal function (creatinine: 1.14±0.29, P=0.68), total cholesterol (179.9±59.9, P=0.22), or CRP (1.17±3.5; P=0.48). There is correlation between AAA size and CRP serum levels, however there was no statically significant reduction of CRP after EVAR.

Discussion:

MiRNA-1281 expression may be influenced by cholesterol, triglycerides levels, and renal function. We found no difference in these markers before and six months after EVAR. However, miRNA-1281 presents a significant reduction in patients with no follow-up complications. We hypothesize that miRNA-1281 expression may be related to aortic wall stress or flow changes.

Conclusion:

MiRNA-1281 may contribute as a possible marker of EVAR follow-up.

Metformin and insulin-resistant related diseases: Emphasis on the role of microRNAs

Metformin is one of the most prescribed drugs in type II diabetes (T2DM) which has recently found new applications in the prevention and treatment of various illnesses, from metabolic disorders to cardiovascular and age-related diseases. Metformin improves insulin resistance (IR) by modulating metabolic mechanisms and mitochondrial biogenesis. Alternation of microRNAs (miRs) in the treatment of IR-related illnesses has been observed by metformin therapy. MiRs are small non-coding RNAs that play important roles in RNA silencing, targeting the 3'untranslated region (3'UTR) of most mRNAs and inhibiting the translation of related proteins. As a result, their dysregulation is associated with many diseases. Metformin may alter miRs levels in the treatment of various diseases by AMPK-dependent or AMPK-independent mechanisms. Here, we summarized the therapeutic role of metformin by modifying the aberrant expression of miRs as potential biomarkers or therapeutic targets in diseases in which IR plays a key role.

Excessive expression of miR-1a by statin causes skeletal injury through targeting mitogen-activated protein kinase kinase kinase 1

Backgrounds: A major side effect of statin, a widely used drug to treat hyperlipidemia, is skeletal myopathy through cell apoptosis. The aim of this study is to investigate the roles of microRNA in statin-induced injury.

Methods: Apolipoprotein E knockout (ApoE-/-) mice were administered with simvastatin (20 mg/kg/day) for 8 weeks. Exercise capacity was evaluated by hanging grid test, forelimb grip strength, and running tolerance test.

Results: In cultured skeletal muscle cells, statin increased the levels of miR-1a but decreased the levels of mitogen-activated protein kinase kinase kinase 1 (MAP3K1) in a time or dose dependent manner. Both computational target-scan analysis and luciferase gene reporter assay indicated that MAP3K1 is the target gene of miR-1a. Statin induced cell apoptosis of skeletal muscle cells, but abolished by downregulating of miR-1a or upregulation of MAP3K1. Further, the effects of miR-1a inhibition on statin-induced cell apoptosis were ablated by MAP3K1 siRNA. In ApoE-/- mice, statin induced cell apoptosis of skeletal muscle cells and decreased exercise capacity in mice infected with vector, but not in mice with lentivirus-mediated miR-1a gene silence.

Conclusion: Statin causes skeletal injury through induction of miR-1a excessive expression to decrease MAP3K1 gene expression.

Vitamin B6 inhibits macrophage activation to prevent lipopolysaccharide-induced acute pneumonia in mice

Macrophage activation participates in the pathogenesis of pulmonary inflammation. As a coenzyme, vitamin B6 (VitB6) is mainly involved in the metabolism of amino acids, nucleic acids, glycogen and lipids. We have previously reported that activation of AMP‐activated protein kinase (AMPK) produces anti‐inflammatory effects both in vitro and in vivo. Whether VitB6 via AMPK activation prevents pulmonary inflammation remains unknown. The model of acute pneumonia was induced by injecting mice with lipopolysaccharide (LPS). The inflammation was determined by measuring the levels of interleukin‐1 beta (IL‐1β), IL‐6 and tumour necrosis factor alpha (TNF‐α) using real time PCR, ELISA and immunohistochemistry. Exposure of cultured primary macrophages to VitB6 increased AMP‐activated protein kinase (AMPK) Thr172 phosphorylation in a time/dose‐dependent manner, which was inhibited by compound C. VitB6 downregulated the inflammatory gene expressions including IL‐1β, IL‐6 and TNF‐α in macrophages challenged with LPS. These effects of VitB6 were mirrored by AMPK activator 5‐aminoimidazole‐4‐carboxamide ribonucleoside (AICAR). However, VitB6 was unable to inhibit LPS‐induced macrophage activation if AMPK was in deficient through siRNA‐mediated approaches. Further, the anti‐inflammatory effects produced by VitB6 or AICAR in LPS‐treated macrophages were abolished in DOK3 gene knockout (DOK3^−/−) macrophages, but were enhanced in macrophages if DOK3 was overexpressed. In vivo studies indicated that administration of VitB6 remarkably inhibited LPS‐induced both systemic inflammation and acute pneumonia in wild‐type mice, but not in DOK3^−/− mice. VitB6 prevents LPS‐induced acute pulmonary inflammation in mice via the inhibition of macrophage activation.

Administration of losartan improves aortic arterial stiffness and reduces the occurrence of acute coronary syndrome in aged patients with essential hypertension

BACKGROUNDS AND AIMS

Increased arterial stiffness may increase cardiovascular morbidity and mortality. Angiotensin II type 1 receptor blocker losartan is potentially useful in controlling the central blood pressure and arterial stiffness in mild to moderate essential hypertension, while the effects of losartan in aged patients with essential hypertension are not entirely investigated.

METHODS

The carotid-femoral arterial pulse wave velocity (PWV) was measured in aged patients with essential hypertension.

RESULTS

In a cross-sectional study, PWV value was significantly higher in these old patients with essential hypertension, compared with patients without essential hypertension. Logistic regression analysis indicated that age, hypertension duration, and losartan treatment are risk factors of arterial stiffness. In a perspective study, long-term administration of losartan (50 mg/d) remarkably reduced PWV in aged patients with essential hypertension. In a longitudinal study, PWV is an independent predictor of the occurrence of acute coronary syndrome (ACS) in elderly patients with essential hypertension by using multivariate analysis. Further, the ACS occurrence was reduced by long-term administration of losartan in aged patients with essential hypertension, compared with the old hypertensive patients without taking losartan.

CONCLUSION

Losartan treatment is a negative risk factor of arterial stiffness and reduces the risk of ACS in aged patients with essential hypertension.

Angiotensin II type 1 receptor blockers prevent aortic arterial stiffness in elderly patients with hypertension

Backgrounds and aims: Increased arterial stiffness may increase cardiovascular morbidity and mortality. Angiotensin II type 1 receptor blockers (ARBs) are potentially useful in controlling the central blood pressure and arterial stiffness in mild to moderate essential hypertension, while the effects of ARBs in aged patients with essential hypertension are not entirely investigated. Methods: The carotid-femoral arterial pulse wave velocity (PWV) was measured in aged patients with essential hypertension. Results: In a cross-sectional study, PWV value was significantly higher in these old patients with essential hypertension, compared to patients without essential hypertension. In correlation analysis, PWV was associated positively with age, hypertension duration, and carotid atherosclerosis. However, there was no relationship between PWV and gender in aged patients with essential hypertension. In a perspective study, 6-12 months administration of ARBs (losartan, 50 mg/day; telmisartan, 40 mg/day; valsartan 80 mg/day; irbesartan, 150 mg/day) remarkably reduced PWV in aged patients with essential hypertension. Regression analyses of multiple factors indicated that the effects of ARBs on arterial stiffness were not associated with the reduction of blood pressure. Conclusion: ARB treatment is a negative risk factor of arterial stiffness in aged patients with essential hypertension.

AMPKα inactivation destabilizes atherosclerotic plaque in streptozotocin-induced diabetic mice through AP-2α/miRNA-124 axis

Diabetes mellitus is one of risk factors of cardiovascular diseases including atherosclerosis. Whether and how diabetes promotes the formation of unstable atherosclerotic plaque is not fully understood. Here, we show that streptozotocin-induced type 1 diabetes reduced collagen synthesis, leading to the formation of unstable atherosclerotic plaque induced by collar placement around carotid in apolipoprotein E knockout (Apoe^-/-) mice. These detrimental effects of hyperglycemia on plaque stability were reversed by metformin in vivo without altering the levels of blood glucose and lipids. Mechanistically, we found that high glucose reduced the phosphorylated level of AMP-activated protein kinase alpha (AMPKα) and the transcriptional activity of activator protein 2 alpha (AP-2α), increased the expression of miR-124 expression, and downregulated prolyl-4-hydroxylase alpha 1 (P4Hα1) protein expression and collagen biosynthesis in cultured vascular smooth muscle cells. Importantly, these in vitro effects produced by high glucose were abolished by AMPKα pharmacological activation or adenovirus-mediated AMPKα overexpression. Further, adenovirus-mediated AMPKα gain of function remitted the process of diabetes-induced plaque destabilization in Apoe^-/- mice injected with streptozotocin. Administration of metformin enhanced pAP-2α level, reduced miR-124 expression, and increased P4Hα1 and collagens in carotid atherosclerotic plaque in diabetic Apoe^-/- mice. We conclude that streptozotocin-induced toxic diabetes promotes the formation of unstable atherosclerotic plaques based on the vulnerability index in Apoe^-/- mice, which is related to the inactivation of AMPKα/AP-2α/miRNA-124/P4Hα1 axis. Clinically, targeting AMPKα/AP-2α/miRNA-124/P4Hα1 signaling should be considered to increase the plaque stability in patients with atherosclerosis.

KEY MESSAGES

Hyperglycemia reduced collagen synthesis, leading to the formation of unstable atherosclerotic plaque induced by collar placement around carotid in apolipoprotein E knockout mice. Hyperglycemia destabilizes atherosclerotic plaque in vivo through an AMPKα/AP-2α/miRNA-124/P4Hα1-dependent collagen synthesis. Metformin functions as a stabilizer of atherosclerotic plaque to reduce acute coronary accent.