RATIONALE:In some patients with type 2 diabetes mellitus (DM) without hypertension, cardiac hypertrophy and attenuated cardiac function are observed, and this insult is termed diabetic ...cardiomyopathy. To date, microRNA (miRNAs or miR) functions in diabetic cardiomyopathy remain to be elucidated.
OBJECTIVE:To clarify the functions of miRNAs involved in diabetic cardiomyopathy caused by type 2 DM.
METHODS AND RESULTS:C57BL/6 mice were fed a high-fat diet (HFD) for 20 weeks, which induced obesity and type 2 DM. miRNA microarray analyses and real-time polymerase chain reaction revealed that miR-451 levels were significantly increased in the type 2 DM mouse hearts. Because excess supply of saturated fatty acids is a cause of diabetic cardiomyopathy, we stimulated neonatal rat cardiac myocytes with palmitic acid and confirmed that miR-451 expression was increased in a dose- and time-dependent manner. Loss of miR-451 function ameliorated palmitate-induced lipotoxicity in neonatal rat cardiac myocytes. Calcium-binding protein 39 (Cab39) is a scaffold protein of liver kinase B1 (LKB1), an upstream kinase of AMP-activated protein kinase (AMPK). Cab39 was a direct target of miR-451 in neonatal rat cardiac myocytes and Cab39 overexpression rescued the lipotoxicity. To clarify miR-451 functions in vivo, we generated cardiomyocyte-specific miR-451 knockout mice. HFD-induced cardiac hypertrophy and contractile reserves were ameliorated in cardiomyocyte-specific miR-451 knockout mice compared with control mice. Protein levels of Cab39 and phosphorylated AMPK were increased and phosphorylated mammalian target of rapamycin (mTOR) was reduced in cardiomyocyte-specific miR-451 knockout mouse hearts compared with control mouse hearts.
CONCLUSIONS:Our results demonstrate that miR-451 is involved in diabetic cardiomyopathy through suppression of the LKB1/AMPK pathway.
MicroRNAs (miRs) are small non-protein-coding RNAs that bind to specific mRNAs and inhibit translation or promote mRNA degradation. Recent reports have indicated that miR-33, which is located within ...the intron of sterol regulatory element-binding protein (SREBP) 2, controls cholesterol homoeostasis and may be a potential therapeutic target for the treatment of atherosclerosis. Here we show that deletion of miR-33 results in marked worsening of high-fat diet-induced obesity and liver steatosis. Using miR-33(-/-)Srebf1(+/-) mice, we demonstrate that SREBP-1 is a target of miR-33 and that the mechanisms leading to obesity and liver steatosis in miR-33(-/-) mice involve enhanced expression of SREBP-1. These results elucidate a novel interaction between SREBP-1 and SREBP-2 mediated by miR-33 in vivo.
OBJECTIVE—Abdominal aortic aneurysm (AAA) is an increasingly prevalent and ultimately fatal disease with no effective pharmacological treatment. Because matrix degradation induced by vascular ...inflammation is the major pathophysiology of AAA, attenuation of this inflammation may improve its outcome. Previous studies suggested that microRNA-33 inhibition and genetic ablation of microRNA-33 increased serum high-density lipoprotein cholesterol and attenuated atherosclerosis.
APPROACH AND RESULTS—MicroRNA-33a-5p expression in central zone of human AAA was higher than marginal zone. MicroRNA-33 deletion attenuated AAA formation in both mouse models of angiotensin II– and calcium chloride–induced AAA. Reduced macrophage accumulation and monocyte chemotactic protein-1 expression were observed in calcium chloride–induced AAA walls in microRNA-33 mice. In vitro experiments revealed that peritoneal macrophages from microRNA-33 mice showed reduced matrix metalloproteinase 9 expression levels via c-Jun N-terminal kinase inactivation. Primary aortic vascular smooth muscle cells from microRNA-33 mice showed reduced monocyte chemotactic protein-1 expression by p38 mitogen-activated protein kinase attenuation. Both of the inactivation of c-Jun N-terminal kinase and p38 mitogen-activated protein kinase were possibly because of the increase of ATP-binding cassette transporter A1 that is a well-known target of microRNA-33. Moreover, high-density lipoprotein cholesterol derived from microRNA-33 mice reduced expression of matrix metalloproteinase 9 in macrophages and monocyte chemotactic protein-1 in vascular smooth muscle cells. Bone marrow transplantation experiments indicated that microRNA-33–deficient bone marrow cells ameliorated AAA formation in wild-type recipients. MicroRNA-33 deficiency in recipient mice was also shown to contribute the inhibition of AAA formation.
CONCLUSIONS—These data strongly suggest that inhibition of microRNA-33 will be effective as a novel strategy for treating AAA.
Recent studies demonstrate that microRNAs show promising potential, including angiogenesis, in therapeutic intervention. MicroRNA-126 (miR-126) is reported to regulate angiogenesis by blocking ...Sprouty-related EVH1 domain-containing protein 1 (SPRED1), an endogenous inhibitor of vascular endothelial cell growth factor. In this study, we investigated the angiogenic effects of the sustained release of miR-126 loaded with poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) in a murine hindlimb ischemia model.
We induced mice hindlimb ischemia through femoral artery excision. We randomly assigned the mice to two groups and performed an intramuscular injection of miR-126-loaded PLGA NPs (miR-126) or scrambled miR-loaded PLGA NPs (control) shortly after induction of ischemia.
The miR-126 expression levels in the ischemic limb at 3 days after treatment were significantly higher in mice treated with miR-126-loaded PLGA NPs than in those with scrambled miR, indicating the fair efficiency of local miR transduction (control vs miR-126: 0.33 ± 0.12 vs 0.74 ± 0.42; P < .05; n = 6). Laser Doppler perfusion imaging revealed that limb blood flow in mice treated with miR-126-loaded PLGA NPs was significantly higher at 14 days after treatment (sham vs control vs miR-126: 0.62 ± 0.09 vs 0.58 ± 0.05 vs 0.72 ± 0.07; P < .001; n = 12). Immunohistochemical analysis indicated that CD31-positive cell density and α-smooth muscle actin-positive vessel density were significantly higher in miR-126-treated mice (control vs miR-126: 0.33 ± 0.12 vs 0.74 ± 0.42; P < .05; n = 6). SPRED1 messenger RNA expression levels were significantly lower in miR-126-treated mice (control vs miR-126: 1.00 ± 0.05 vs 0.81 ± 0.07; P < .05; n = 6). Western blotting indicated that protein levels of pERK/ERK mediated by SPRED1 were significantly higher in miR-126-treated mice (control vs miR-126: 0.29 ± 0.10 vs 0.54 ± 0.21; P < .05; n = 6).
This study suggests that sustained release of miR-126-loaded PLGA NPs might be an effective method in therapeutic angiogenesis for hindlimb ischemia.
Severe clinical limb ischemia resistant to conventional treatments, including medication, percutaneous angioplasty, and bypass surgery, remains a serious health care problem. Therapeutic angiogenesis that induces angiogenesis at the ischemic site could be a novel and effective approach for this severe condition. Here, we developed a therapeutic approach combining microRNA-126 and a drug delivery system using poly lactic-co-glycolic acid nanoparticles, which showed novel therapeutic potential on a mouse hindlimb ischemia model. This therapeutic approach could be a promising new strategy after verification of the safety and long-term therapeutic effects in clinical studies in the future.
We herein report a case of congenital long QT syndrome (LQTS) in which the QT interval was prolonged by Takotsubo syndrome (TTS), inducing ventricular fibrillation (VF). The patient was a 55-year-old ...woman who had been diagnosed with LQTS. Cardiopulmonary arrest occurred while coughing during sleep. VF was observed, and her heartbeat returned after two defibrillations. An electrocardiogram showed marked QT prolongation and large negative T waves. Echocardiography demonstrated hyperkinesis at the base of the left ventricle and akinesis at the apex. As there was no significant stenosis in the coronary artery, she was diagnosed with TTS.
Background The cardio-ankle vascular index (CAVI) has been recently reported as a new index of aortic stiffness, which is less influenced by blood pressure than pulse wave velocity (PWV). The present ...study investigated the relationship between the levels of CAVI and carotid and coronary arteriosclerosis. Methods and Results The 443 consecutive patients who underwent CAVI, carotid sonography, and coronary angiography in hospital were examined. Intima - media thickness (IMT) and carotid plaque were evaluated by ultrasonography. The severity of coronary artery disease (CAD) was evaluated by coronary angiography and the subjects were divided into 4 groups (0, no significant organic stenosis: 1, 1-vessel disease: 2, 2-vessel disease: 3, 3-vessel disease). Univariate analyses showed that both CAVI and brachial-ankle PWV (baPWV) were associated with IMT and the presence of carotid plaque. Multiple stepwise regression analyses revealed that CAVI (p=0.0427), but not baPWV, was associated with the IMT. Both CAVI (p<0.0001) and baPWV (p=0.0140) were significantly associated with the severity of CAD. Multiple logistic analyses revealed that CAVI (p=0.0342), but not baPWV (p=0.8027), was associated with the presence of multivessel disease. Conclusion High CAVI implies progression of carotid and coronary arteriosclerosis. CAVI may be more closely linked with arteriosclerosis than baPWV. (Circ J 2008; 72: 1762 - 1767)
Despite recent progress with drug-eluting stents, restenosis and thrombosis after endovascular intervention are still major limitations in the treatment of cardiovascular diseases. These problems are ...possibly caused by inappropriate inhibition of neointimal formation and retardation of re-endothelialization on the surface of the stents. miR-126 has been shown to have the potential to enhance vascular endothelial cell proliferation.
We designed and constructed a 27-nt double strand RNA (dsRNA) conjugated to cholesterol, which has high membrane permeability, and formed mature miR-126 after transfection. For site-specific induction of miR-126, we utilized poly (DL-lactide-co-glycolide) nanoparticles (NPs). miR-126-dsRNA-containing NPs (miR-126 NPs) significantly reduced the protein expression of a previously identified miR-126 target, SPRED1, in human umbilical vascular endothelial cells (HUVECs), and miR-126 NPs enhanced the proliferation and migration of HUVECs. On the other hand, miR-126 NPs reduced the proliferation and migration of vascular smooth muscle cells, via the suppression of IRS-1. Finally, we developed a stent system that eluted miR-126. This delivery system exhibited significant inhibition of neointimal formation in a rabbit model of restenosis.
miR-126 NP-conjugated stents significantly inhibited the development of neointimal hyperplasia in rabbits. The present study may indicate the possibility of a novel therapeutic option to prevent restenosis after angioplasty.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Vaccinations are the main tool being used to control the COVID-19 pandemic. When the Japanese Ministry of Health approved the Moderna mRNA-1273 vaccination in May 2021, it was limited to patients ...over 18 years old; however, using the additional data of efficacy and safety from clinical trials, vaccination was approved for 12- to 17-year-olds in Japan in July 2021. A previous study reported that myocarditis after the mRNA-1273 vaccination was more prevalent in young men; however, no patients under 18 years old with myocarditis diagnosed by cardiovascular magnetic resonance (CMR) findings after mRNA-1273 vaccination have been reported in Japan. In the present case, a 17-year-old healthy male developed arthralgia and had fever on the day of the second mRNA-1273 vaccination for severe acute respiratory syndrome coronavirus 2. Three days after the vaccination, the patient felt severe chest pain with broad ST elevations on electrocardiography and troponin T elevations. Symptoms and findings rapidly improved; however, on CMR, myocarditis remained. Thus, it is necessary to be vigilant of potential acute myocarditis in young men following mRNA-1273 vaccination.
Although it is very rare, acute myocarditis after mRNA-1273 (Moderna) vaccination developed within 3–5 days following the second dose of the vaccine.
Most reported cases were mild or moderate in severity, but there were cases of cardiogenic shock. We need to be vigilant of acute myocarditis in young men following mRNA-1273 vaccination.
MicroRNAs (miRs) are small non-protein-coding RNAs that bind to specific mRNAs and inhibit translation or promote mRNA degradation. Recent reports, including ours, indicated that miR-33a located ...within the intron of sterol regulatory element-binding protein (SREBP) 2 controls cholesterol homeostasis and can be a possible therapeutic target for treating atherosclerosis. Primates, but not rodents, express miR-33b from an intron of SREBF1. Therefore, humanized mice, in which a miR-33b transgene is inserted within a Srebf1 intron, are required to address its function in vivo. We successfully established miR-33b knock-in (KI) mice and found that protein levels of known miR-33a target genes, such as ABCA1, ABCG1, and SREBP-1, were reduced compared with those in wild-type mice. As a consequence, macrophages from the miR-33b KI mice had a reduced cholesterol efflux capacity via apoA-I and HDL-C. Moreover, HDL-C levels were reduced by almost 35% even in miR-33b KI hetero mice compared with the control mice. These results indicate that miR-33b may account for lower HDL-C levels in humans than those in mice and that miR-33b is possibly utilized for a feedback mechanism to regulate its host gene SREBF1. Our mice will also aid in elucidating the roles of miR-33a/b in different genetic disease models.
Recently, it has been reported that specific microRNA (miRNA) levels are elevated in serum and can be used as biomarkers in patients with cardiovascular diseases. However, miRNAs expression profiles ...and their sources in pericardial fluid (PF) are unclear.
The purpose of this study was to identify the levels of miRNAs in PF in relation to those in the serum in patients undergoing cardiac surgery. Serum (S) and PF from patients undergoing coronary artery bypass graft (CABG) due to stable angina pectoris (sAP) and unstable AP (uAP) and aortic valve replacement due to aortic stenosis (AS) were analyzed for the detection of miRNAs. We named these samples S-sAP, S-uAP, S-AS, PF-sAP, PF-uAP, and PF-AS, respectively. We first measured the levels of miR-423-5p, which was recognized previously as a biomarker for heart failure. miR-423-5p levels were significantly higher in PF than serum. Although there was no difference in miR-423-5p levels among the PF-AS, PF-sAP, and PF-uAP, its levels were significantly elevated in S-uAP compared with those in S-AS and S-sAP. In order to clarify the source of miR-423-5p in PF, we measured the levels of muscle-enriched miR-133a and vascular-enriched miR-126 and miR-92a in the same samples. miR-133a levels were significantly higher in serum than in PF, and it was elevated in S-uAP compared with S-AS. miR-126 level was significantly increased in serum compared with PF, and the level of miR-92a the similar tendency. miR-423-5p is located in the first intron of NSRP1. There is another miRNA, miR-3184, encoded in the opposite direction in the same region. In vitro experiments indicated that the duplex of miR-423-5p and miR-3184-3p was more resistant to RNase than the duplex of miR-423-5p and miR-133-3p, which may help to stabilize miR-423-5p in the PF.
Our results suggested that miR-423-5p is enriched in PF, and serum miR-423-5p may be associate with uAP. Its expression pattern was different to that of muscle- and vascular-enriched miRNAs, miR-133a, miR-126, and miR-92a.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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