Exosomal MALAT1 Derived from High Glucose-Treated Macrophages Up-Regulates Resistin Expression via miR-150-5p Downregulation.

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) plays a crucial role in the pathophysiological process associated with diabetes-related complications. The effect of high glucose levels on macrophage-derived exosomal MALAT1 is unknown. Therefore, we investigated the molecular regulatory mechanisms controlling exosomal MALAT1 in macrophages under high glucose treatment and the therapeutic target of macrophage-derived exosomal MALAT1 using a balloon injury model of vascular disease in diabetic rats. High glucose (25 mM) significantly increased MALAT1 expression in macrophage-derived exosomes. MALAT1 suppressed miR-150-5p expression in macrophage-derived exosomes under high-glucose conditions. Silencing MALAT1 using MALAT1 siRNA significantly reversed miR-150-5p expression induced by macrophage-derived exosomes. Macrophage-derived exosomes under high-glucose treatment significantly increased resistin expression in macrophages. Silencing MALAT1 and overexpression of miR-150-5p significantly decreased resistin expression induced by macrophage-derived exosomes. Overexpression of miR-150-5p significantly decreased resistin luciferase activity induced by macrophage-derived exosomes. Macrophage-derived exosome significantly decreased glucose uptake in macrophages and silencing MALAT1, resistin or overexpression of miR-150-5p significantly reversed glucose uptake. Balloon injury to the carotid artery significantly increased MALAT1 and resistin expression and significantly decreased miR-150-5p expression in arterial tissue. Silencing MALAT1 significantly reversed miR-150-5p expression in arterial tissue after balloon injury. Silencing MALAT1 or overexpression of miR-150-5p significantly reduced resistin expression after balloon injury. In conclusion, high glucose up-regulates MALAT1 to suppress miR-150-5p expression and counteracts the inhibitory effect of miR-150-5p on resistin expression in macrophages to promote vascular disease. Macrophage-derived exosomes containing MALAT1 may serve as a novel cell-free approach for the treatment of vascular disease in diabetes mellitus.

Chrysin boosts KLF2 expression through suppression of endothelial cell-derived exosomal microRNA-92a in the model of atheroprotection.

PURPOSE: Atherosclerosis and its related clinical complications are the leading cause of death. MicroRNA (miR)-92a in the inflammatory endothelial dysfunction leads to atherosclerosis. Krüppel-like factor 2 (KLF2) is required for vascular integrity and endothelial function maintenance. Flavonoids possess many biological properties. This study investigated the vascular protective effects of chrysin in balloon-injured carotid arteries. MATERIALS AND METHODS: Exosomes were extracted from human coronary artery endothelial cell (HCAEC) culture media. Herb flavonoids and chrysin were the treatments in these atheroprotective models. Western blotting and real-time PCRs were performed. In situ hybridization, immunohistochemistry, and immunofluorescence analyses were employed. RESULTS: MiR-92a increased after balloon injury and was present in HCAEC culture media. Chrysin was treated, and significantly attenuated the miR-92a levels after balloon injury, and similar results were obtained in HCAEC cultures in vitro. Balloon injury-induced miR-92a expression, and attenuated KLF2 expression. Chrysin increased the KLF2 but reduced exosomal miR-92a secretion. The addition of chrysin and antagomir-92a, neointimal formation was reduced by 44.8 and 49.0% compared with balloon injury after 14 days, respectively. CONCLUSION: Chrysin upregulated KLF2 expression in atheroprotection and attenuated endothelial cell-derived miR-92a-containing exosomes. The suppressive effect of miR-92a suggests that chrysin plays an atheroprotective role. Proposed pathway for human coronary artery endothelial cell (HCAEC)-derived exosomes induced by chrysin to suppress microRNA (miR)-92a expression and counteract the inhibitory effect of miR-92a on KLF2 expression in HCAECs. This provides an outline of the critical role of the herbal flavonoid chrysin, which may serve as a valuable therapeutic supplement for atheroprotection.

Hyperbaric oxygen-induced long non-coding RNA MALAT1 exosomes suppress MicroRNA-92a expression in a rat model of acute myocardial infarction.

Hyperbaric oxygen (HBO) improves angiogenesis. The effect of HBO on metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a pro-angiogenic long non-coding RNA, in cardiac myocyte-derived exosomes and acute myocardial infarction (AMI) is unknown. We aimed to investigate whether MALAT1 is altered in cardiac myocyte-derived exosomes in response to HBO as well as the molecular regulatory mechanisms of MALAT1 in cardiac myocytes treated with HBO. Cardiac myocytes were cultured, and HBO was applied at 2.5 atmosphere absolute in a hyperbaric chamber. Exosomes were extracted from the culture media. A rat model of AMI generated by the ligation of the left anterior descending artery was used. HBO significantly increased MALAT1 expression in cardiac myocytes and HBO-induced MALAT1 and exosomes attenuated miR-92a expression after myocardial infarction. Expression of krüppel-like factor 2 (KLF2) and CD31 was significantly decreased after infarction and HBO-induced exosomes significantly reversed the expression. Silencing of MALAT1 using MALAT1-locked nucleic acid GapmeR significantly attenuated KLF2 and CD31 protein expression after infarction induced by HBO-induced exosomes. HBO-induced exosomes also decreased infarct size significantly. HBO-induced exosomes from cardiac myocytes up-regulate MALAT1 to suppress miR-92a expression and counteract the inhibitory effect of miR-92a on KLF2 and CD31 expression in left ventricular myocardium after myocardial infarction to enhance neovascularization.

Catalpol Ameliorates Neointimal Hyperplasia in Diabetic Rats.

Catalpol, an iridoid glycoside, is an isolated natural product of Rehmannia glutinosa, which has been reported to have antidiabetic properties. This study investigated the vascular protective effects of catalpol in hyperglycemic rats with balloon-injured carotid arteries. Balloon injury stress led to the upregulation of monocyte chemoattractant protein-1 expression in rats with streptozotocin-induced diabetes. Western blotting and real-time PCR were performed. In situ hybridization, immunohistochemistry, and confocal analyses were employed. Monocyte chemoattractant protein-1 levels were increased through streptozotocin induction or balloon injury. After treatment with catalpol, the neointimal hyperplasia area was reduced 2 weeks after balloon injury in hyperglycemic rats. Real-time PCR and immunohistochemical analysis demonstrated reduced levels of monocyte chemoattractant protein-1 2 weeks after the balloon injury. Monocyte chemoattractant protein-1 expression was significantly increased in balloon-injured rats compared with the control groups. Thus, treatment with catalpol affected monocyte chemoattractant protein-1 expression. This study demonstrated that catalpol downregulated monocyte chemoattractant protein-1 expression in carotid arteries and ameliorated neointimal hyperplasia in hyperglycemic rats. The suppressive effect of monocyte chemoattractant protein-1 suggests that it plays a key role in neointimal hyperplasia. The results imply that catalpol is potentially effective for preventing hyperglycemia-related ischemic cardiac diseases.

Genomic landscape of CD34+ hematopoietic cells in myelodysplastic syndrome and gene mutation profiles as prognostic markers.

Myelodysplastic syndrome (MDS) includes a group of diseases characterized by dysplasia of bone marrow myeloid lineages with ineffective hematopoiesis and frequent evolution to acute myeloid leukemia (AML). Whole-genome sequencing was performed in CD34(+) hematopoietic stem/progenitor cells (HSPCs) from eight cases of refractory anemia with excess blasts (RAEB), the high-risk subtype of MDS. The nucleotide substitution patterns were found similar to those reported in AML, and mutations of 96 protein-coding genes were identified. Clonal architecture analysis revealed the presence of subclones in six of eight cases, whereas mutation detection of CD34(+) versus CD34(-) cells revealed heterogeneity of HSPC expansion status. With 39 marker genes belonging to eight functional categories, mutations were analyzed in 196 MDS cases including mostly RAEB (n = 89) and refractory cytopenia with multilineage dysplasia (RCMD) (n = 95). At least one gene mutation was detected in 91.0% of RAEB, contrary to that in RCMD (55.8%), suggesting a higher mutational burden in the former group. Gene abnormality patterns differed between MDS and AML, with mutations of activated signaling molecules and NPM1 being rare, whereas those of spliceosome more common, in MDS. Finally, gene mutation profiles also bore prognostic value in terms of overall survival and progression free survival.

Genome-wide association study identifies a novel susceptibility gene for serum TSH levels in Chinese populations.

Thyroid-stimulating hormone (TSH) is a sensitive indicator of thyroid function. High and low TSH levels reflect hypothyroidism and hyperthyroidism, respectively. Even within the normal range, small differences in TSH levels, on the order of 0.5-1.0 mU/l, are associated with significant differences in blood pressure, BMI, dyslipidemia, risk of atrial fibrillation and atherosclerosis. Most of the variance in TSH levels is thought to be genetically influenced. We conducted a genome-wide association study of TSH levels in 1346 Chinese Han individuals. In the replication study, we genotyped four candidate SNPs with the top association signals in an independent isolated Chinese She cohort (n = 3235). We identified a novel serum TSH susceptibility locus within XKR4 at 8q12.1 (rs2622590, Pcombined = 2.21 × 10(-10)), and we confirmed two previously reported TSH susceptibility loci near FOXE1 at 9q22.33 and near CAPZB at 1p36.13, respectively. The rs2622590_T allele at XKR4 and the rs925489_C allele near FOXE1 were correlated with low TSH levels and were found to be nominally associated to patients with papillary thyroid carcinoma (PTC) (OR = 1.41, P= 0.014 for rs2622590_T, and OR = 1.61, P= 0.030 for rs925489_C). The rs2622590 and rs925489 genotypes were also correlated with the expression levels of FOXE1 and XKR4, respectively, in PTC tissues (P = 2.41 × 10(-4) and P= 0.02). Our findings suggest that the SNPs in XKR4 and near FOXE1 are involved in the regulation of TSH levels.

Robust evidence for five new Graves' disease risk loci from a staged genome-wide association analysis.

Graves' disease (GD), characterized by autoantibodies targeting antigens specifically expressed in thyroid tissues causing hyperthyroidism, is triggered by a combination of genetic and environmental factors. However, only a few loci for GD risk were confirmed in the various ethnic groups, and additional genetic determinants have to be detected. In this study, we carried out a three-stage study in 9529 patients with GD and 9984 controls to identify new risk loci for GD and found genome-wide significant associations in the overall populations for five novel susceptibility loci: the GPR174-ITM2A at Xq21.1, C1QTNF6-RAC2 at 22q12.3-13.1, SLAMF6 at 1q23.2, ABO at 9q34.2 and an intergenic region harboring two non-coding RNAs at 14q32.2 and one previous indefinite locus, TG at 8q24.22 (Pcombined < 5 × 10(-8)). The genotypes of corresponding variants at 14q32.2 and 8q24.22 were correlated with the expression levels of C14orf64 and a TG transcript skipping exon 46, respectively. This study increased the number of GD loci with compelling evidence and indicated that non-coding RNAs might be potentially involved in the pathogenesis of GD.

Identification of BACH2 as a susceptibility gene for Graves' disease in the Chinese Han population based on a three-stage genome-wide association study.

The BACH2 gene regulates B cell differentiation and function and has been reported to be a shared susceptibility gene for several autoimmune diseases. Our previous genome-wide association study (GWAS) indicated that several single nucleotide polymorphisms (SNPs) in the BACH2 gene are associated with Graves' disease (GD) in the Chinese Han population; however, the association did not achieve genome-wide significance levels. Recently, this association of BACH2 with GD was confirmed in Caucasians in the UK population, but fine mapping in this region has not yet been reported. Here, we provide a refined analysis of a 331-kb region in the BACH2 gene, which harbors 359 SNPs, using GWAS data from 1,442 GD patients and 1,468 controls. The SNPs rs2474619 and rs9344996 were implied as the independent variants associated with GD by forward and two-locus logistic regression analysis. We genotyped eight out of 10 tagSNPs with P < 1 × 10(-3) in 3,508 GD patients and 3,209 controls, the results also showed that rs2474619 was independently associated with GD in the combined population from GWAS and the second stage (P = 1.81 × 10(-5)). The rs2474619 and rs9344996 were further genotyped in the third stage cohorts, and rs2474619 showed evidence of association with GD at genome-wide significance levels in the combined population (P = 3.28 × 10(-8), odds ratio = 1.13). The association of rs9344996 with GD can be explained by its linkage to rs2474619 in the combined population. Our study clearly demonstrated that BACH2 is a susceptibility gene for GD in the Chinese Han population and further supported rs2474619, in intron 2 of BACH2, is the best association signal with GD. However, the mechanism by which BACH2 confers increased risk of GD requires further study.

Phenotypic and molecular characteristics in eleven Chinese patients with 5α-reductase Type 2 deficiency.

CONTEXT: Steroid 5α-reductase type 2 deficiency (5α-RD2) is a male-limited, autosomal recessive inherited disease. Affected 46, XY individuals usually present with ambiguous genitalia at birth. An early and precise diagnosis is of great value to the long-term prognosis of the disease. OBJECTIVE: To describe the clinical features and molecular determinants in 11 Chinese patients with the SRD5A2 gene mutation and to investigate the functional alteration arising from a novel splicing site mutation identified in one of the patients. SUBJECTS AND METHODS: Eleven subjects born with abnormal external genitalia from 10 unrelated families were recruited. Among them, nine patients who were reared as girls underwent virilization and gender change after puberty. Genotyping analysis of the SRD5A2 gene was performed in each of the patients. Haplotype analysis was performed in five patients with a prevalent mutation of p.G203S to illustrate the founder effect in China. Functional impairment of the new variant was explored by an in vitro splicing study and enzymatic activity assay. RESULTS: Nine mutations in the SRD5A2 gene were detected in the eleven patients. In addition to the previously reported p.G203S, p.R227Q, p.N193S, p.R246Q, p.Q6X, p.A228V, c.655delT and IVS1-2 A>G, a novel splicing site mutation (IVS4 + 2 T>C) was identified. From an in vitro functional study, this mutation was found to result in a skipping of exon 4 in the course of mRNA splicing, leading to a truncated protein of 205 amino acids that lacks the catalysing activity. Two siblings with the same compound heterozygous mutation (IVS1-2A>G/p.G203S) exhibited differing phenotypes and opposite patterns of gender rearing. A prevalent variation p.V89L combined with c.655delT was revealed to cause a mild phenotype of 5α-RD2 with a micropenis. CONCLUSION: This cohort study describes the phenotypic, biochemical and long-term outcome in 11 Chinese patients with 5α-RD2 deficiency and defines the genotypic spectrum of SRD5A2 mutations in China.

Exosomal MALAT1 from macrophages treated with high levels of glucose upregulates LC3B expression via miR-204-5p downregulation.

BACKGROUND: Metastasis-associated lung adenocarcinoma transcript 1 ( MALAT1 ) plays a critical role in the pathophysiology of diabetes-related complications. However, whether macrophage-derived MALAT1 affects autophagic activity under hyperglycemic conditions is unclear. Therefore, we investigated the molecular regulatory mechanisms of macrophage-derived MALAT1 and autophagy under hyperglycemic conditions. METHODS: Hyperglycemia was induced by culturing macrophages in 25 mM glucose for 1 hour. Exosomes were extracted from the culture media. A rat model of carotid artery balloon injury was established to assess the effect of MALAT1 on vascular injury. Reverse transcription, real-time quantitative polymerase chain reaction, western blotting, immunohistochemical staining, and luciferase activity assays were performed. RESULTS: Stimulation with high levels of glucose significantly enhanced MALAT1 expression in macrophage-derived exosomes. MALAT1 inhibited miR-204-5p expression in macrophage-derived exosomes under hyperglycemic conditions. siRNA-induced silencing of MALAT1 significantly reversed macrophage-derived exosome-induced miR-204-5p expression. Hyperglycemic treatment caused a significant, exosome-induced increase in the expression of the autophagy marker LC3B in macrophages. Silencing MALAT1 and overexpression of miR-204-5p significantly decreased LC3B expression induced by macrophage-derived exosomes. Overexpression of miR-204-5p significantly reduced LC3B luciferase activity induced by macrophage-derived exosomes. Balloon injury to the carotid artery in rats significantly enhanced MALAT1 and LC3B expression, and significantly reduced miR-204-5p expression in carotid artery tissue. Silencing MALAT1 significantly reversed miR-204-5p expression in carotid artery tissue after balloon injury. MALAT1 silencing or miR-204-5p overexpression significantly reduced LC3B expression after balloon injury. CONCLUSION: This study demonstrated that hyperglycemia upregulates MALAT1 . MALAT1 suppresses miR-204-5p expression and counteracts the inhibitory effect of miR-204-5p on LC3B expression in macrophages to promote vascular disease.

Dense mapping of IL2RA shows no association with Graves' disease in Chinese Han population.

OBJECTIVE: Associations between IL2RA and various autoimmune diseases have been reported in Caucasians. We investigated whether genetic polymorphisms at the IL2RA locus were associated with Graves' disease (GD) in the Chinese Han population. DESIGN: We performed a genome-wide association study (GWAS) in 1 536 GD patients and 1 516 controls. The 1000 Genomes Project data were adopted as references for imputation analysis. After forward and conditional logistic regressions, we found that rs11256313 was the major risk variant in the CD25/IL2RA region. Thus, we further genotyped rs11256313 in a replication cohort with 3 694 GD patients and 3 510 controls using ABI 7900HT TaqMan Real-Time PCR System. RESULTS: Nine single nucleotide polymorphisms (SNPs) in the IL2RA block were nominally associated with GD in our GWAS (0·01 < P < 0·05). After imputation analysis, 13 imputed SNPs in the IL2RA block were weakly associated with GD (P ≤ 0·05). Logistic regression analysis suggested that the imputed rs11256313 could represent the IL2RA block (P = 0·003). However, we failed to replicate the association of rs11256313 in a larger cohort (P = 0·145). A subphenotype analysis of rs11256313 on thyroid hormone receptor antibody (TRAb) and gender showed that there was no association in any of the subphenotype groups (P > 0·05). CONCLUSIONS: The results suggested that common genetic polymorphisms at IL2RA do not exert a significant genetic effect on the development of GD in the Chinese Han population. Previously reported associations between CD25/IL2RA and autoimmune diseases including GD in Caucasians again imply that heterogeneity exists in different ethnic populations.

Stevioside ameliorates high-fat diet-induced insulin resistance and adipose tissue inflammation by downregulating the NF-κB pathway.

Accumulating evidence suggests that adipose tissue is the main source of pro-inflammatory molecules that predispose individuals to insulin resistance. Stevioside (SVS) is a widely used sweetener with multiple beneficial effects for diabetic patients. In this study, we investigated the effect of SVS on insulin resistance and the pro-inflammatory state of adipose tissue in mice fed with a high-fat diet (HFD). Oral administration of SVS for 1month had no effect on body weight, but it significantly improved fasting glucose, basal insulin levels, glucose tolerance and whole body insulin sensitivity. Interestingly, these changes were accompanied with decreased expression levels of several inflammatory cytokines in adipose tissue, including TNF-α, IL6, IL10, IL1ß, KC, MIP-1α, CD11b and CD14. Moreover, macrophage infiltration in adipose tissue was remarkably reduced by SVS. Finally, SVS significantly suppressed the nuclear factor-kappa b (NF-κB) signaling pathway in adipose tissue. Collectively, these results suggested that SVS may ameliorate insulin resistance in HFD-fed mice by attenuating adipose tissue inflammation and inhibiting the NF-κB pathway.

Functional study of an aberrant splicing variant of the human luteinizing hormone (LH) receptor.

The luteinizing hormone receptor (LHR) is a member of a subfamily of G protein-coupled receptors that is characterized by its alternative splicing. In a previous study, we identified a splice site mutation of intron 6 (IVS6-3C>A) in a patient suffering from Leydig cell hypoplasia, which leads to aberrant splicing of LHR mRNA. In vitro expression analysis confirmed that this mutation results in the skipping of exon 7 in the mature mRNA of the LHR gene. In this study, we determined the impact of IVS6-3C>A on the RNA secondary structure and function of LHR-Del7. The three-dimensional structure of the leucine-rich repeats in LHR was predicted by molecular modeling. Radioactive ligand-binding assays verified that LHR-Del7 has no binding affinity for hCG. Furthermore, we detected negligible cAMP production in cells transfected with LHR-Del7. Cells co-expressing LHR-WT and LHR-Del7 were able to generate cAMP in response to hCG, but there was no significant difference between cells transfected with LHR-WT/vector and LHR-WT/LHR-Del7, although the variant was able to localize to cell surface, similar to wild-type receptor. These results indicated that LHR-Del7 does not have a dominant negative effect on LHR-WT cell surface expression, and although the pathological splicing variant LHR-Del7 was able to localize to cell membranes it failed to bind hCG and had no effect on wild-type LHR.

Functional SNPs in the SCGB3A2 promoter are associated with susceptibility to Graves' disease.

Graves' disease (GD) is one of the most common human autoimmune diseases, and recent data estimated a prevalence of clinical hyperthyroidism of 0.25-1.09% in the population. Several reports have linked GD to the region 5q12-q33; and a locus between markers D5s436 and D5s434 was specifically linked to GD susceptibility in the Chinese population. In the present study, association analysis was performed using a large number of single-nucleotide polymorphisms (SNPs) at this locus in 2811 patients with GD recruited from different geographic regions of China. The strongest associations with GD in the combined Chinese Han cohorts were mapped to two SNPs in the promoter (pSNP) of SCGB3A2 [SNP76, rs1368408, P = 1.43 x 10(-6), odds ratio (OR) = 1.28 and SNP75, -623 - -622, P = 7.62 x 10(-5), OR = 1.32, respectively], a gene implicated in immune regulation. On the other hand, pSNP haplotypes composed of the SNP76 (rs1368408)+SNP74 (rs6882292) or SNP76+SNP75 (-623 approximately -622, AG/T) variants are correlated with high disease susceptibility (P = 0.0007, and P = 0.0192, respectively) in this combined Chinese Han cohort. Furthermore, these haplotypes were associated with reduced SCGB3A2 gene expression levels in human thyroid tissue, while functional analysis revealed a relatively low efficiency of SCGB3A2 promoters of the SNP76+SNP75 and SNP76+SNP74 haplotypes in driving gene expression. These results suggest that the SCGB3A2 gene may contribute to GD susceptibility.

Lack of association between the TGF-ß(1) gene and development of COPD in Asians: a case-control study and meta-analysis.

Abnormalities in the transforming growth factor-ß(1) (TGF-ß(1)) gene are thought to be linked to chronic obstructive pulmonary disease (COPD). We investigated the association between the single nuclear polymorphisms (SNPs) of TGF-ß(1) and the risk of COPD in a case-control study and meta-analysis. We genotyped 160 cases and 177 control subjects in a local hospital using the Mass-Array(TM) Technology Platform and then tested the association of four SNPs in TGF-ß(1) (rs6957, rs1800469, rs2241712, and rs2241718) with COPD. Plasma TGF-ß(1) level measurement was performed later. A database covering all papers published up to October 30, 2010, was then reviewed. Statistical analysis was performed using Revman 5.0 and STATA 11.0 software. No association was found between TGF-ß(1) gene SNPs and an increased risk of COPD in Asians. By meta-analysis, the link of two polymorphisms, rs1800469 and rs1982073, was investigated in seven and eight studies, respectively, involving 1,508 COPD patients and 2,608 control subjects. The results showed that there was no significant association between an increased risk of COPD in carriers of the T allele (TT+TC) versus the CC genotype in rs1800469 and rs1982073. In ethnic subgroup analysis, the risk of COPD associated with the rs1800469 T allele was not significantly elevated among Asians. TGF-ß(1) gene polymorphisms are not associated with an increased risk of COPD in the Asian population.

Identification of a locus for autosomal dominant high myopia on chromosome 5p13.3-p15.1 in a Chinese family.

PURPOSE: Myopia and its extreme form, high myopia, are common vision disorders worldwide, especially in Asia. Identifying genetic markers is a useful step toward understanding the genetic basis of high myopia, particularly in the Chinese population, where it is highly prevalent. This study was conducted to provide evidence of linkage for autosomal dominant high myopia to a locus on chromosome 5p13.3-p15.1 in a large Chinese family. METHODS: After clinical evaluation, genomic DNA from 29 members of this family was genotyped. A genome-wide screen was then performed using 382 markers with an average inter-marker distance of 10 cM, and two-point linkage was analyzed using the MLINK program. Mutation analysis of the candidate genes was performed using direct sequencing. RESULTS: Linkage to the known autosomal dominant high myopia loci was excluded. The genome-wide screening identified a maximum two-point LOD score of 3.71 at θ=0.00 with the microsatellite marker D5S502. Fine mapping and haplotype analysis defined a critical region of 11.69 cM between D5S2096 and D5S1986 on chromosome 5p13.3-p15.1. Sequence analysis of the candidate genes inside the linked region did not identify any causative mutations. CONCLUSIONS: A genetic locus was mapped to chromosome 5p13.3-p15.1 in a large Chinese family with autosomal dominant high myopia.

(-)-Epigallocatechin Gallate Promotes MicroRNA 145 Expression against Myocardial Hypoxic Injury through Dab2/Wnt3a/ß-catenin.

MicroRNA 145 (miR-145) is a critical modulator of cardiovascular diseases. The downregulation of myocardial miR-145 is followed by an increase in disabled-2 (Dab2) expression in cardiomyocytes. (-)-epigallocatechin gallate (EGCG) is a flavonoid that has been evaluated extensively due to its diverse pharmacological properties including anti-inflammatory effects. The aim of this study was to investigate the cardioprotective effects of EGCG under hypoxia-induced stress in vitro and in vivo. The hypoxic insult led to the suppression of miR-145 expression in cultured rat cardiomyocytes in a concentration-dependent manner. Western blotting and real-time PCR were performed. In rat myocardial infarction study, in situ hybridization, and immunofluorescent analyses were adopted. The western blot and real-time PCR data revealed that hypoxic stress with 2.5% O2 suppressed the expression of miR-145 and Wnt3a/ß-catenin in cultured rat cardiomyocytes but augmented Dab2. Treatment with EGCG attenuated Dab2 expression, but increased Wnt3a and ß-catenin in hypoxic cultured cardiomyocytes. Following in vivo myocardial infarction (MI) study, the data revealed the myocardial infarct area reduced by 48.5%, 44.6%, and 48.5% in EGCG (50mg/kg) or miR-145 dominant or Dab2 siRNA groups after myocardial infarction for 28 days, respectively. This study demonstrated that EGCG increased miR-145, Wnt3a, and ß-catenin expression but attenuated Dab2 expression. Moreover, EGCG ameliorated myocardial ischemia in vivo. The novel suppressive effect was mediated through the miR-145 and Dab2/Wnt3a/ß-catenin pathways.

Expression of adiponectin receptors in mouse adrenal glands and the adrenocortical Y-1 cell line: adiponectin regulates steroidogenesis.

Obesity is frequently associated with malfunctions of the hypothalamus-pituitary-adrenal (HPA) axis and hyperaldosteronism, but the mechanism underlying this association remains unclear. Since the adrenal glands are embedded in adipose tissue, direct cross-talk between adipose tissue and the adrenal gland has been proposed. A previous study found that adiponectin receptor mRNA was expressed in human adrenal glands and aldosterone-producing adenoma (APA). However, the expression of adiponectin receptors in adrenal glands has not been confirmed at the protein level or in other species. Furthermore, it is unclear whether adiponectin receptors expressed in adrenal cells are functional. We found, for the first time, that adiponectin receptor (AdipoR1 and AdipoR2) mRNA and protein were expressed in mouse adrenal and adrenocortical Y-1 cells. However, adiponectin itself was not expressed in mouse adrenal or Y-1 cells. Furthermore, adiponectin acutely reduced basal levels of corticosterone and aldosterone secretion. ACTH-induced steroid secretion was also inhibited by adiponectin, and this was accompanied by a parallel change in the expression of the key genes involved in steroidogenesis. These findings indicate that adiponectin may take part in the modulation of steroidogenesis. Thus, adiponectin is likely to have physiological and/or pathophysiological significance as an endocrine regulator of adrenocortical function.

[Overexpression of angiotensin converting enzyme 2 inhibits inflammatory response of atherosclerotic plaques in hypercholesterolemic rabbits].

OBJECTIVE: Angiotensin converting enzyme 2 (ACE2) efficiently hydrolyses the potent vasoconstrictor angiotensin II to vasodilative angiotensin (1-7). We hypothesized that ACE2 overexpression may inhibit inflammation response in atherosclerotic plaque by degrading Ang II into Ang-(1-7). METHODS: Atherosclerosis (AS) plaques were induced in the abdominal aorta of 38 rabbits by endothelial injury and atherogenic diet for 3 months. Rabbits were then underwent injection of a recombinant adenovirus (2.5 x 10(9) pfu/ml) carrying a murine ACE2 gene (Ad-ACE2) through a catheter into the abdominal aortic segments rich in plaques (n = 19) or injection of a control vector Ad-EGFP (n = 19). One month later, all rabbits were sacrificed and plaques from aortic segments were analyzed. RESULTS: ACE2 expression in aortic tissues of the Ad-ACE2 group were confirmed by immunohistochemistry. Macrophage infiltration (13.6% +/- 4.2% vs. 23.6% +/- 6.9%, P < 0.01) and MCP-1 expression (13.2% +/- 0.4% vs. 25.0% +/- 7.4%, P < 0.01) were significantly reduced in Ad-ACE2 group compared to Ad-EGFP group. CONCLUSIONS: Overexpression of ACE2 inhibited atherosclerotic plaque inflammation response in hypercholesterolemic rabbits.

Hyperbaric oxygen boosts long noncoding RNA MALAT1 exosome secretion to suppress microRNA-92a expression in therapeutic angiogenesis.

BACKGROUND: Hyperbaric oxygen (HBO) could improve wound healing by enhancement of angiogenesis. The effect of HBO on metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a proangiogenic long noncoding RNA, and on endothelial cell-derived exosome is unknown. We aim to investigate both whether MALAT1 is altered in human coronary artery endothelial cells (HCAECs)-derived exosomes in response to HBO as well as the molecular regulatory mechanisms of MALAT1 in HCAECs under HBO treatment. METHODS AND RESULTS: HCAECs were cultured and HBO was applied at 2.5 atmosphere absolute (ATA) in a hyperbaric chamber. Exosomes were extracted from culture media. A rat model of hind-limb ischemia was performed by ligation of the right femoral artery. HBO at 2.5 ATA significantly increased MALAT1 expression in HCAECs and HCAECs-derived exosomes. MALAT1 suppressed miR-92a expression in HCAEC-derived exosomes under HBO. Silencing MALAT1 by MALAT1 siRNA significantly inhibited KLF2 mRNA expression induced by HBO, as did MiR-92a. MiR-92a significantly decreased KLF2 luciferase activity in HCAECs under HBO. HBO and HBO-induced exosomes significantly increased cell proliferation and the capillary-like network formation of HCAECs. MALAT1 siRNA and miR-92a overexpression significantly attenuated the cell proliferation and tube formation caused by HBO-induced exosome. HBO and HBO-induced exosomes significantly improved neovascularization in a rat model of hind-limb ischemia. CONCLUSIONS: HBO upregulates MALAT1 to suppress miR-92a expression and counteracts the inhibitory effect of miR-92a on KLF2 expression in HCAECs to enhance neovascularization. HBO-induced derivation of exosomes from HCAECs enhances angiogenesis. Exosomes containing MALAT1 might serve as a valuable therapeutic tool for neovascularization by HBO.