Histone Deacetylase 3: A Potential Therapeutic Target for Atherosclerosis.

Atherosclerosis, the pathological basis of most cardiovascular disease, is characterized by plaque formation in the intima. Secondary lesions include intraplaque hemorrhage, plaque rupture, and local thrombosis. Vascular endothelial function impairment and smooth muscle cell migration lead to vascular dysfunction, which is conducive to the formation of macrophage-derived foam cells and aggravates inflammatory response and lipid accumulation that cause atherosclerosis. Histone deacetylase (HDAC) is an epigenetic modifying enzyme closely related to chromatin structure and gene transcriptional regulation. Emerging studies have demonstrated that the Class I member HDAC3 of the HDAC super family has cell-specific functions in atherosclerosis, including 1) maintenance of endothelial integrity and functions, 2) regulation of vascular smooth muscle cell proliferation and migration, 3) modulation of macrophage phenotype, and 4) influence on foam cell formation. Although several studies have shown that HDAC3 may be a promising therapeutic target, only a few HDAC3-selective inhibitors have been thoroughly researched and reported. Here, we specifically summarize the impact of HDAC3 and its inhibitors on vascular function, inflammation, lipid accumulation, and plaque stability in the development of atherosclerosis with the hopes of opening up new opportunities for the treatment of cardiovascular diseases.

Emerging roles of growth differentiation factor-15 in brain disorders (Review).

Brain disorders, such as Alzheimer's and Parkinson's disease and cerebral stroke, are an important contributor to mortality and disability worldwide, where their pathogenesis is currently a topic of intense research. The mechanisms underlying the development of brain disorders are complex and vary widely, including aberrant protein aggregation, ischemic cell necrosis and neuronal dysfunction. Previous studies have found that the expression and function of growth differentiation factor-15 (GDF15) is closely associated with the incidence of brain disorders. GDF15 is a member of the TGFß superfamily, which is a dimer-structured stress-response protein. The expression of GDF15 is regulated by a number of proteins upstream, including p53, early growth response-1, non-coding RNAs and hormones. In particular, GDF15 has been reported to serve an important role in regulating angiogenesis, apoptosis, lipid metabolism and inflammation. For example, GDF15 can promote angiogenesis by promoting the proliferation of human umbilical vein endothelial cells, apoptosis of prostate cancer cells and fat metabolism in fasted mice, and GDF15 can decrease the inflammatory response of lipopolysaccharide-treated mice. The present article reviews the structure and biosynthesis of GDF15, in addition to the possible roles of GDF15 in Alzheimer's disease, cerebral stroke and Parkinson's disease. The purpose of the present review is to summarize the mechanism underlying the role of GDF15 in various brain disorders, which hopes to provide evidence and guide the prevention and treatment of these debilitating conditions.

Role of Exosomes in Brain Diseases.

Exosomes are a subset of extracellular vesicles that act as messengers to facilitate communication between cells. Non-coding RNAs, proteins, lipids, and microRNAs are delivered by the exosomes to target molecules (such as proteins, mRNAs, or DNA) of host cells, thereby playing a key role in the maintenance of normal brain function. However, exosomes are also involved in the occurrence, prognosis, and clinical treatment of brain diseases, such as Alzheimer's disease, Parkinson's disease, stroke, and traumatic brain injury. In this review, we have summarized novel findings that elucidate the role of exosomes in the occurrence, prognosis, and treatment of brain diseases.

Hepatic cholesterol transport and its role in non-alcoholic fatty liver disease and atherosclerosis.

Non-alcoholic fatty liver disease (NAFLD) is a quickly emerging global health problem representing the most common chronic liver disease in the world. Atherosclerotic cardiovascular disease represents the leading cause of mortality in NAFLD patients. Cholesterol metabolism has a crucial role in the pathogenesis of both NAFLD and atherosclerosis. The liver is the major organ for cholesterol metabolism. Abnormal hepatic cholesterol metabolism not only leads to NAFLD but also drives the development of atherosclerotic dyslipidemia. The cholesterol level in hepatocytes reflects the dynamic balance between endogenous synthesis, uptake, esterification, and export, a process in which cholesterol is converted to neutral cholesteryl esters either for storage in cytosolic lipid droplets or for secretion as a major constituent of plasma lipoproteins, including very-low-density lipoproteins, chylomicrons, high-density lipoproteins, and low-density lipoproteins. In this review, we describe decades of research aimed at identifying key molecules and cellular players involved in each main aspect of hepatic cholesterol metabolism. Furthermore, we summarize the recent advances regarding the biological processes of hepatic cholesterol transport and its role in NAFLD and atherosclerosis.

N6-Adenosine Methylation (m6A) RNA Modification: an Emerging Role in Cardiovascular Diseases.

N6-methyladenosine (m6A) is the most abundant and prevalent epigenetic modification of mRNA in mammals. This dynamic modification is regulated by m6A methyltransferases and demethylases, which control the fate of target mRNAs through influencing splicing, translation and decay. Recent studies suggest that m6A modification plays an important role in the progress of cardiac remodeling and cardiomyocyte contractile function. However, the exact roles of m6A in cardiovascular diseases (CVDs) have not been fully explained. In this review, we summarize the current roles of the m6A methylation in the progress of CVDs, such as cardiac remodeling, heart failure, atherosclerosis (AS), and congenital heart disease. Furthermore, we seek to explore the potential risk mechanisms of m6A in CVDs, including obesity, inflammation, adipogenesis, insulin resistance (IR), hypertension, and type 2 diabetes mellitus (T2DM), which may provide novel therapeutic targets for the treatment of CVDs.

Development and validation of a Chinese-language instrument measuring empowerment needs of patients after a percutaneous coronary intervention.

Patient empowerment has been shown to have some positive impacts on self-efficacy, self-esteem, and recovery. However, information about the empowerment needs of patients after a percutaneous coronary intervention is scarce. The aim of this study was to develop a Chinese-language instrument to measure empowerment needs of such patients. The initial instrument was generated based on a literature review and interviews with patients after a percutaneous coronary intervention procedure. Content validity was tested with a panel of experts using the Delphi method. In total, 226 patients were recruited for psychometric tests using the revised instrument. Expert authority coefficient was 0.92, and content validity index was 0.95. The internal consistency reliability was demonstrated by Cronbach's α coefficients (0.86 for the total score, 0.66-0.74 for the dimensions). The newly developed 19-item, five-dimension instrument has shown satisfactory validity (face/content validity and construct validity) and internal consistency reliability. The instrument could help clinical nurses who have close contact with patients after a percutaneous coronary intervention to gain a better understanding of their empowerment needs and could help develop appropriate health education to address such needs.

Nicotinate-curcumin ameliorates cognitive impairment in diabetic rats by rescuing autophagic flux in CA1 hippocampus.

INTRODUCTION: Our previous study has confirmed that a novel curcumin derivate nicotinate-curcumin (NC) can facilitate autophagic flux in THP-1 cells induced by oxidized low-density lipoprotein. AIMS: Given that autophagy plays critical roles in neurodegenerative diseases, the present study was carried out to investigate whether NC can improve cognitive function of rats with diabetes mellitus (DM) via restoring autophagic flux in CA1 hippocampus. RESULTS: Our results showed that NC treatment improved cognitive deficit and attenuated neuronal loss as well as cellular ultrastructure impairment in the CA1 region of DM rats induced by streptozotocin. Moreover, NC lowered the expressions of the apoptosis-related proteins Bcl-2, Bax, Cyt-c, and cleaved Caspase-3. Notably, NC treatment reversed autophagic flux impairment as evidenced by the deceases in LC3-II and p62 protein levels, and autophagosome accumulation in the hippocampal CA1 region of DM rats. However, these protective effects of NC were abolished by cotreatment with 3-methyladenine (an autophagy inhibitor) and chloroquine (an autophagic flux inhibitor), respectively. Furthermore, NC treatment decreased the expressions of phosphorylated mammalian target of rapamycin (mTOR) and p70 ribosomal protein S6 kinase (p70S6k) proteins in the CA1 region of DM rats. CONCLUSIONS: These results indicate that NC ameliorates DM-induced cognitive function impairment via restoring autophagic flux might by inhibiting mTOR/p70S6k activation in the CA1 region, and NC may be a promising agent for diabetic cognitive dysfunction prevention and treatment.

Nobiletin reduces LPL-mediated lipid accumulation and pro-inflammatory cytokine secretion through upregulation of miR-590 expression.

Nobiletin has protective effects on cardiovascular diseases, but the mechanism is not clear. In this study, we examined whether nobiletin affects the expression of miR-590/LPL and its relative effects on lipid accumulation and pro-inflammatory cytokine secretion in human THP-1 macrophages. RT-qPCR analysis showed that nobiletin increased the expression of miR-590. Western blot analysis showed that nobiletin-suppressed LPL expression was enhanced by miR-590 mimic and abrogated by miR-590 inhibitor. Oil Red O staining and high-performance liquid chromatography assays showed that nobiletin attenuated lipid accumulation in macrophages. Treatment with nobiletin and miR-590 mimic decreased cellular lipid accumulation, whereas treatment with miR-590 inhibitor increased cellular lipid accumulation. ELISA illustrated that nobiletin alleviated pro-inflammatory cytokine secretion in macrophages as measured by, which was reduced by miR-590 mimic and increased by miR-590 inhibitor. In conclusion, nobiletin may alleviate lipid accumulation and secretion of pro-inflammatory cytokines by enhancing the inhibitory effect of miR-590 on LPL expression, suggesting a promising strategy for potential drug development for atherosclerosis.

MicroRNA-296: a promising target in the pathogenesis of atherosclerosis?

Atherosclerosis has been recognized as an inflammatory disease involving the vascular wall. MicroRNAs are a group of small noncoding RNAs to regulate gene expression at the transcriptional level through mRNA degradation or translation repression. Recent studies suggest that miR-296 may play crucial roles in the regulation of angiogenesis, inflammatory response, cholesterol metabolism, hypertension, cellular proliferation and apoptosis. In this review, we primarily discussed the molecular targets of miR-296 involved in the development of atherosclerosis, which may provide a basis for future investigation and a better understanding of the biological functions of miR-296 in atherosclerosis.

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.

Lipoprotein lipase: Biosynthesis, regulatory factors, and its role in atherosclerosis and other diseases.

Lipoprotein lipase (LPL) is a rate-limiting enzyme that catalyzes hydrolysis of the triglyceride (TG) core of circulating TG-rich lipoproteins including chylomicrons (CM), low-density lipoproteins (LDL) and very low-density lipoproteins (VLDL). A variety of parenchymal cells can synthesize and secrete LPL. Recent studies have demonstrated that complicated processes are involved in LPL biosynthesis, secretion and transport. The enzyme activity of LPL is regulated by many factors, such as apolipoproteins, angiopoietins, hormones and miRNAs. In this article, we also reviewed the roles of LPL in atherosclerosis, coronary heart disease, cerebrovascular accident, Alzheimer disease and chronic lymphocytic leukemia. LPL in different tissues exerts differential physiological functions. The role of LPL in atherosclerosis is still controversial as reported in the literature. Here, we focused on the properties of LPL derived from macrophages, endothelial cells and smooth muscle cells in the vascular wall. We also explore the existence of crosstalk between LPL and those cells when the molecule mainly plays a proatherogenic role. This review will provide insightful knowledge of LPL and open new therapeutic perspectives.

miR-758-5p regulates cholesterol uptake via targeting the CD36 3'UTR.

miR-758-3p plays an important role via regulting ABCA1-mediated cholesterol efflux in atherosclerosis. However, the mechanism of miR-758-5p in cholesterol metabolism is still unclear. Here, we revealed that miR-758-5p decreased total cholesterol accumulation in THP-1 macrophage derived foam cells through markedly reducing cholesterol uptake, and no effect on the cholesterol efflux. Interestingly, computational analysis suggests that CD36 may be a target gene of miR-758-5p. Our study further demonstrated that miR-758-5p decreased CD36 expression at both protein and mRNA levels via targeting the CD36 3'UTR in THP-1 macrophage derived foam cells. The present present study concluded that miR-758-5p decreases lipid accumulation of foam cell via regulating CD36-mediated the cholesterol uptake. Therefore, targeting miR-758-5p may offer a promising strategy to treat atherosclerotic vascular disease.

MicroRNA-182 Promotes Lipoprotein Lipase Expression and Atherogenesisby Targeting Histone Deacetylase 9 in Apolipoprotein E-Knockout Mice.

BACKGROUND: Lipoprotein lipase (LPL) expressed in macrophages plays an important role in promoting the development of atherosclerosis or atherogenesis. MicroRNA-182 (miR-182) is involved in the regulation of lipid metabolism and inflammation. However, it remains unclear how miR-182 regulates LPL and atherogenesis.Methods and Results:Using bioinformatics analyses and a dual-luciferase reporter assay, we identified histone deacetylase 9 (HDAC9) as a target gene of miR-182. Moreover, miR-182 upregulated LPL expression by directly targetingHDAC9in THP-1 macrophages. Hematoxylin-eosin (H&E), Oil Red O and Masson's trichrome staining showed that apolipoprotein E (ApoE)-knockout (KO) mice treated with miR-182 exhibited more severe atherosclerotic plaques. Treatment with miR-182 increased CD68 and LPL expression in atherosclerotic lesions in ApoE-KO mice, as indicated by double immunofluorescence staining in the aortic sinus. Increased miR-182-induced increases in LPL expression in ApoE-KO mice was confirmed by real-time quantitative polymerase chain reaction and western blotting analyses. Treatment with miR-182 also increased plasma concentrations of proinflammatory cytokines and lipids in ApoE-KO mice. CONCLUSIONS: The results of the present study suggest that miR-182 upregulates LPL expression, promotes lipid accumulation in atherosclerotic lesions, and increases proinflammatory cytokine secretion, likely through targetingHDAC9, leading to an acceleration of atherogenesis in ApoE-KO mice.

MicroRNA-27 Prevents Atherosclerosis by Suppressing Lipoprotein Lipase-Induced Lipid Accumulation and Inflammatory Response in Apolipoprotein E Knockout Mice.

Atherosclerotic lesions are lipometabolic disorder characterized by chronic progressive inflammation in arterial walls. Previous studies have shown that macrophage-derived lipoprotein lipase (LPL) might be a key factor that promotes atherosclerosis by accelerating lipid accumulation and proinflammatory cytokine secretion. Increasing evidence indicates that microRNA-27 (miR-27) has beneficial effects on lipid metabolism and inflammatory response. However, it has not been fully understood whether miR-27 affects the expression of LPL and subsequent development of atherosclerosis in apolipoprotein E knockout (apoE KO) mice. To address these questions and its potential mechanisms, oxidized low-density lipoprotein (ox-LDL)-treated THP-1 macrophages were transfected with the miR-27 mimics/inhibitors and apoE KO mice fed high-fat diet were given a tail vein injection with miR-27 agomir/antagomir, followed by exploring the potential roles of miR-27. MiR-27 agomir significantly down-regulated LPL expression in aorta and peritoneal macrophages by western blot and real-time PCR analyses. We performed LPL activity assay in the culture media and found that miR-27 reduced LPL activity. ELISA showed that miR-27 reduced inflammatory response as analyzed in vitro and in vivo experiments. Our results showed that miR-27 had an inhibitory effect on the levels of lipid both in plasma and in peritoneal macrophages of apoE KO mice as examined by HPLC. Consistently, miR-27 suppressed the expression of scavenger receptors associated with lipid uptake in ox-LDL-treated THP-1 macrophages. In addition, transfection with LPL siRNA inhibited the miR-27 inhibitor-induced lipid accumulation and proinflammatory cytokines secretion in ox-LDL-treated THP-1 macrophages. Finally, systemic treatment revealed that miR-27 decreased aortic plaque size and lipid content in apoE KO mice. The present results provide evidence that a novel antiatherogenic role of miR-27 was closely related to reducing lipid accumulation and inflammatory response via downregulation of LPL gene expression, suggesting a potential strategy to the diagnosis and treatment of atherosclerosis.

Histone Methyltransferase Enhancer of Zeste Homolog 2-Mediated ABCA1 Promoter DNA Methylation Contributes to the Progression of Atherosclerosis.

ATP-binding cassette transporter A1 (ABCA1) plays a critical role in maintaining cellular cholesterol homeostasis. The purpose of this study is to identify the molecular mechanism(s) underlying ABCA1 epigenetic modification and determine its potential impact on ABCA1 expression in macrophage-derived foam cell formation and atherosclerosis development. DNA methylation induced foam cell formation from macrophages and promoted atherosclerosis in apolipoprotein E-deficient (apoE-/-) mice. Bioinformatics analyses revealed a large CpG island (CGI) located in the promoter region of ABCA1. Histone methyltransferase enhancer of zeste homolog 2 (EZH2) downregulated ABCA1 mRNA and protein expression in THP-1 and RAW264.7 macrophage-derived foam cells. Pharmacological inhibition of DNA methyltransferase 1 (DNMT1) with 5-Aza-dC or knockdown of DNMT1 prevented the downregulation of macrophage ABCA1 expression, suggesting a role of DNA methylation in ABCA1 expression. Polycomb protein EZH2 induced DNMT1 expression and methyl-CpG-binding protein-2 (MeCP2) recruitment, and stimulated the binding of DNMT1 and MeCP2 to ABCA1 promoter, thereby promoting ABCA1 gene DNA methylation and atherosclerosis. Knockdown of DNMT1 inhibited EZH2-induced downregulation of ABCA1 in macrophages. Conversely, EZH2 overexpression stimulated DNMT1-induced ABCA1 gene promoter methylation and atherosclerosis. EZH2-induced downregulation of ABCA1 gene expression promotes foam cell formation and the development of atherosclerosis by DNA methylation of ABCA1 gene promoter.

Apelin-13 Prevents the Delayed Neuropathy Induced by Tri-ortho-cresyl Phosphate Through Regulation the Autophagy Flux in Hens.

Organophosphate-induced delayed neuropathy (OPIDN) is pathologically characterized by the swollen axon containing aggregations of microtubules, neurofilaments, smooth endoplasmic reticulum and multivesicular vesicles. At present, the exact mechanism of OPIDN is unclear and the effective therapeutic methods is not available to counter this syndrome. Recent studies had shown that the autophagy was involved in OPIDN. The adipocytokine Apelin is a peptide, Apelin and its receptor are abundantly expressed in the nervous system. Recent researches illuminated that Apelin was neuroprotective factor and Apelin could regulate the autophagy in vivo and vitro model. So we investigated the effect of Apelin-13 on the OPIDN induced by Tri-ortho-cresyl phosphate (TOCP) in hens and explored the role of autophagy in Apelin-13 preventing OPIDN. Adult Roman hens were given a single dose of 750 mg/kg TOCP by gavage for 21 days to induce OPIDN, and neural dysfunction were detected, and the formation of autophagosomes in spinal cord neurons was observed by transmission electron microscopy, and the molecular markers of autophagy microtubule-associated protein light chain-3 (LC3) and the autophagy substrates p62/SQSTM1 were determined by Western blot analysis. The results demonstrated that the obvious neurological dysfunction such as hindlimb paralysis and paralysis of gait was present, the number of autophagosomes in the neurons of spinal cords was significantly increased, the level of LC3-II and p62 expressions and the ratio of LC3-II/LC3-I in spinal cords and sciatic nerve were significantly increased in the OPIDN model group compared with the control group. Compared with the OPIDN model group, the neurological dysfunction of tens was obviously reduced, the clinical signs scores was significantly decreased, the number of autophagosomes in the neurons of hen spinal cords was significantly decreased, the level of LC3-II and p62 expressions and the ratio of LC3-II/LC3-I in spinal cords and sciatic nerve were significantly decreased in Apelin-13 treatment group. Our results suggested that Apelin-13 prevented against the OPIDN induced by TOCP in hens, which the mechanism might be associated with regulation autophagy flux by Apelin-13.

MicroRNA-590 Inhibits Lipoprotein Lipase Expression and Prevents Atherosclerosis in apoE Knockout Mice.

Recent studies have suggested that miR-590 may play critical roles in cardiovascular disease. This study was designed to determine the effects of miR-590 on lipoprotein lipase (LPL) expression and development of atherosclerosis in apolipoprotein E knockout (apoE-/-) mice and explore the potential mechanisms. En face analysis of the whole aorta revealed that miR-590 significantly decreased aortic atherosclerotic plaque size and lipid content in apoE-/- mice. Double immunofluorescence staining in cross-sections of the proximal aorta showed that miR-590 agomir reduced CD68 and LPL expression in macrophages in atherosclerotic lesions. MiR-590 agomir down-regulated LPL mRNA and protein expression as analyzed by RT-qPCR and western blotting analyses, respectively. Consistently, miR-590 decreased the expression of CD36 and scavenger receptor A1 (SRA1) mRNA and protein. High-performance liquid chromatography (HPLC)analysis confirmed that treatment with miR-590 agomir reduced lipid levels either in plasma orinabdominal cavity macrophages of apoE-/- mice. ELISA analysis showed that miR-590 agomir decreased plasma levels of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), monocyte chemotactic protein-1 (MCP-1), interleukin-1ß (IL-1ß)and interleukin-6 (IL-6). In contrast, treatment with miR-590 antagomir prevented or reversed these effects. Taken together, these results reveal a novel mechanism of miR-590 effects, and may provide new insights into the development of strategies for attenuating lipid accumulation and pro-inflammatory cytokine secretion.

Diosgenin inhibits atherosclerosis via suppressing the MiR-19b-induced downregulation of ATP-binding cassette transporter A1.

RATIONALE: Diosgenin (Dgn), a structural analogue of cholesterol, has been reported to have the hypolipidemic and antiatherogenic properties, but the underlying mechanisms are not fully understood. Given the key roles of macrophages in cholesterol metabolism and atherogenesis, it is critical to investigate macrophage cholesterol efflux and development of atherosclerotic lesion after Dgn treatment. OBJECTIVE: This study was designed to evaluate the potential effects of Dgn on macrophage cholesterol metabolism and the development of aortic atherosclerosis, and to explore its underlying mechanisms. METHODS AND RESULTS: Dgn significantly up-regulated the expression of ATP-binding cassette transporter A1 (ABCA1) protein, but didn't affect liver X receptor α levels in foam cells derived from human THP-1 macrophages and mouse peritoneal macrophages (MPMs) as determined by western blotting. The miR-19b levels were markedly down-regulated in Dgn-treated THP-1 macrophages/MPM-derived foam cells. Cholesterol transport assays revealed that treatment with Dgn alone or together with miR-19b inhibitor notably enhanced ABCA1-dependent cholesterol efflux, resulting in the reduced levels of total cholesterol, free cholesterol and cholesterol ester as determined by high-performance liquid chromatography. The fecal 3H-sterol originating from cholesterol-laden MPMs was increased in apolipoprotein E knockout mice treated with Dgn or both Dgn and antagomiR-19b. Treatment with Dgn alone or together with antagomiR-19b elevated plasma high-density lipoprotein levels, but reduced plasma low-density lipoprotein levels. Accordingly, aortic lipid deposition and plaque area were reduced, and collagen content and ABCA1 expression were increased in mice treated with Dgn alone or together with antagomiR-19b. However, miR-19b overexpression abrogated the lipid-lowering and atheroprotective effects induced by Dgn. CONCLUSION: The present study demonstrates that Dgn enhances ABCA1-dependent cholesterol efflux and inhibits aortic atherosclerosis progression by suppressing macrophage miR-19b expression.