This study aimed to explore the role of miR-130a-3p in cardiomyocyte hypertrophy and its underlying mechanisms. Pressure-overload induced myocardial hypertrophy mice model was constructed by thoracic aortic constriction (TAC). , norepinephrine (NE) was used to stimulate neonatal rat cardiomyocytes (NRCMs) and H9c2 rat cardiomyocytes to induce hypertrophic phenotypes. The expression of miR-130a-3p was detected in mice hypertrophic myocardium, hypertrophic NRCMs and H9c2 cells. The mimics and inhibitors of miR-130a-3p were transfected into H9c2 cells to observe the role of miR-130a-3p on the hypertrophic phenotype change of cardiomyocytes separately. Furthermore, whether miR-130a-3p regulated hypertrophic related signaling pathways was explored. The results showed that the expression of miR-130a-3p was significantly decreased in hypertrophic myocardium, hypertrophic NRCMs and H9c2 cells. After transfection of miR-130a-3p mimics, the expression of hypertrophic marker genes, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and β-myosin heavy chain (β-MHC), and the cell surface area were notably down-regulated compared with the control group (mimics N.C. + NE group). But after transfection of miR-130a-3p inhibitor, the expression of ANP, BNP and β-MHC in H9c2 cells increased significantly, and the cell area increased further. By Western blot, it was found that the protein phosphorylation level of Akt and mTOR were down-regulated after over-expression of miR-130a-3p. These results suggest that miR-130a-3p mimics may alleviate the degree of cardiomyocyte hypertrophy, meanwhile its inhibitor can further aggravate cardiomyocyte hypertrophy. Over-expression of miR-130a-3p may attenuate cardiomyocytes hypertrophy by affecting the Akt pathway.
Animals ; Atrial Natriuretic Factor ; Cardiomegaly ; Mice ; MicroRNAs ; genetics ; Myocardium ; pathology ; Myocytes, Cardiac ; pathology ; Myosin Heavy Chains ; Natriuretic Peptide, Brain ; Nonmuscle Myosin Type IIB ; Proto-Oncogene Proteins c-akt ; Rats

OBJECTIVETo investigate the effects of evodiamine (Evo), a component of Evodiaminedia rutaecarpa (Juss.) Benth, on cardiomyocyte hypertrophy induced by angiotensin II (Ang II) and further explore the potential mechanisms.

METHODSCardiomyocytes from neonatal Sprague Dawley rats were isolated and characterized, and then the cadiomyocyte cultures were randomly divided into control, model (Ang II 0.1 μmol/L), and Evo (0.03, 0.3, 3 μmol/L) groups. The cardiomyocyte surface area, protein level, intracellular free calcium ([Ca]) concentration, activity of nitric oxide synthase (NOS) and content of nitric oxide (NO) were measured, respectively. The mRNA expressions of atrial natriuretic factor (ANF), calcineurin (CaN), extracellular signal-regulated kinase-2 (ERK-2), and endothelial nitric oxide synthase (eNOS) of cardiomyocytes were analyzed by real-time reverse transcriptionpolymerase chain reaction. The protein expressions of calcineurin catalytic subunit (CnA) and mitogen-activated protein kinase phosphatase-1 (MKP-1) were detected by Western blot analysis.

RESULTSCompared with the control group, Ang II induced cardiomyocytes hypertrophy, as evidenced by increased cardiomyocyte surface area, protein content, and ANF mRNA expression; increased intracellular free calcium ([Ca]) concentration and expressions of CaN mRNA, CnA protein, and ERK-2 mRNA, but decreased MKP-1 protein expression (P<0.05 or P<0.01). Compared with Ang II, Evo (0.3, 3 μmol/L) significantly attenuated Ang II-induced cardiomyocyte hypertrophy, decreased the [Ca] concentration and expressions of CaN mRNA, CnA protein, and ERK-2 mRNA, but increased MKP-1 protein expression (P<0.05 or P<0.01). Most interestingly, Evo increased the NOS activity and NO production, and upregulated the eNOS mRNA expression (P<0.05).

CONCLUSIONEvo signifificantly attenuated Ang II-induced cardiomyocyte hypertrophy, and this effect was partly due to promotion of NO production, reduction of [Ca]i concentration, and inhibition of CaN and ERK-2 signal transduction pathways.

Angiotensin II ; Animals ; Atrial Natriuretic Factor ; metabolism ; Calcineurin ; genetics ; metabolism ; Calcium ; metabolism ; Dual Specificity Phosphatase 1 ; genetics ; metabolism ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Hypertrophy ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Quinazolines ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Rats, Sprague-Dawley

In order to improve the expression of recombinant human atrial natriuretic peptide (ANP), a new plasmid (pET28a(+)/ANP₃) containing 3 tandem ANP genes with lysine codon as the interval linker, was constructed. Target gene was transformed into Escherichia coli BL21 (DE3) and induced by IPTG, about 60% of the total-cell-protein was the target protein, His₆-ANP₃. After denaturation and refolding, it was digested by Endoproteinase Lys-C and Carboxypeptidase B (CPB) and then purified by a series of purification processes, about 16 mg purified ANP monomer could be obtained from one liter bacteria broth of shaking culture. Ultimately, the purity of protein was above 90% determined by UPLC and Tricine SDS-PAGE, its molecular weight was 3 080 Da according to LC-MS identification and it was proved to be equivalent to the reference product by ELISA. The use of tandem gene expression can provide a new possible model for the expression of other peptide drugs.
Atrial Natriuretic Factor ; biosynthesis ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; metabolism ; Gene Expression ; Humans ; Metalloendopeptidases ; Peptides ; Plasmids ; genetics ; Recombinant Fusion Proteins ; biosynthesis

OBJECTIVETo investigate the expression of C-type natriuretic peptides (CNP) and natriuretic peptide receptor-B (NPR-B) receptor in diabetic rats renal cortex, and the regulation by Tongluo Recipe (TLR).

METHODSSixty male SD rats were divided into 3 groups: the normal control group, diabetic model group and diabetic TLR group. Each group was further divided into two subgroups of ten in each, according to 4-week or 12-week observation period. Streptozotocin (STZ)-induced diabetic rats were treated with TLR (1.0 g·kg(-1)·d(-1)) for 4 and 12 weeks, respectively. (1) The essential information was collected for comparing renal mass, serum creatinine and 24 h urine albumen on each group was calculated. (2) CNP mRNA and NPR-B mRNA were detected by realtime-polymerase chain reaction (PCR) on rats renal cortex. (3) Concentration of CNP on renal cortex or serum were analyzed by enzyme-linked immunosorbent assay (ELISA). (4) Pathological evaluation and NPR-B immunostaining for renal tissue were also performed.

RESULTS(1) CNP and NPR-B mRNA levels were detected in each treated or untreated group, with slight elevated in untreated diabetes rats administrated with STZ after 4-week and CNP mRNA level remarkable elevated at 39.21 times higher than normal control group after 12 weeks, but NPR-B mRNA level showed a remarkably down-regulation at 98.07% after 12 weeks. CNP mRNA of TLR-treated group was also elevated after 12-week treatment, but less than untreated group. (2) Concentrations of CNP in renal cortex were obviously increased in treated or untreated diabetes rats, within these groups the treatment of TLR was found more significantly on prompting CNP concentration. Comparing to normal group, serum concentrations of CNP were also increased in treated or untreated diabetic groups, but there was no difference between these diabetic groups. (3) Renal lesions like glomerular volume increased are observed mostly in the relative early stage after 4 weeks. Although TLR treated group had no significant difference in their glomerular volume, the degrees of injury of glomerulus were ameliorated, as well as the NPR-B immunostaining enhanced in glomerulus. Weakly positive immunostaining of NPR-B are observed in glomerulus of normal control, and negative in glomerulus of untreated diabetes rats administrated with STZ after 12 weeks, whereas TLR-treatment groups showed a little enhancement.

CONCLUSIONCNP and NPR-B showed different characteristic on renal cortex at different pathological period in diabetes rats, and TLR regulated their expression.

Animals ; Body Weight ; drug effects ; Diabetes Mellitus, Experimental ; complications ; drug therapy ; genetics ; pathology ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Gene Expression Regulation ; drug effects ; Hematuria ; complications ; genetics ; pathology ; Immunohistochemistry ; Kidney ; drug effects ; metabolism ; pathology ; Kidney Cortex ; drug effects ; metabolism ; pathology ; Kidney Glomerulus ; drug effects ; metabolism ; pathology ; Male ; Natriuretic Peptide, C-Type ; genetics ; metabolism ; Organ Size ; drug effects ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Atrial Natriuretic Factor ; genetics ; metabolism ; Staining and Labeling ; Streptozocin

OBJECTIVETo investigate the associations of guanylate cyclase C (GC-C) mRNA and cytokeratin 20 (CK20) mRNA with metastasis and prognosis in early to moderate colorectal cancer patients.

METHODSGC-C mRNA and CK 20 mRNA in peripheral blood of 74 colorectal cancer patients without distant metastasis were detected by fluorescent quantitative PCR (FQ-PCR). Based on their clinicopathological and postoperative follow-up data, the relationship and clinical significance of these data with metastasis hazards and prognosis factors were analyzed.

RESULTSThe positive rate of GC-C mRNA in 74 colorectal cancer patients was 33.8% (25/74), and CK20 mRNA was 31.1% (23/74). The 1-, 2-, 3- year disease-free survival rates of patients were 94.6%, 82.4% and 78.4% respectively. There were significant differences in positive rates of GC-C mRNA and CK20 mRNA, tumor differentiation, mesentery lymph node metastasis, tumor embolus in vessel and postoperative chemotherapy associated with 3-year disease free survival rate by Kaplan-Meier analysis (all P<0.05). While mesentery lymph node metastasis and tumor embolus in vessel were independent risk factors of 3-year disease-free survival (P<0.05). CK20 mRNA and tumor embolus in vessel were independent risk factors of 3-year disease-free survival by analysis stratified with clinical stage (P<0.05).

CONCLUSIONSDetection of CK20 mRNA and GC-C mRNA in peripheral blood may be important for early detection of early metastasis of colorectal cancer.

Adult ; Aged ; Aged, 80 and over ; Colorectal Neoplasms ; blood ; Female ; Follow-Up Studies ; Humans ; Keratin-20 ; blood ; genetics ; Lymphatic Metastasis ; Male ; Middle Aged ; Prognosis ; RNA, Messenger ; blood ; genetics ; Receptors, Atrial Natriuretic Factor ; blood ; genetics ; Risk Factors

OBJECTIVETo investigate the negative regulation of microRNA-1 (miR-1) on L-type calcium channel beta2 subunit (Cavbeta 2) during cardiomyocyte hypertrophy and its mechanism.

METHODSCardiomyocyte hypertrophy was induced by isoproterenol (ISO). The cell surface area was measured by image analysis system (HJ2000). The targets of miR-1 were predicted by online database microCosm. The 3' untranslated region sequence of Cavbeta 2 was cloned into luciferase reporter vector and then transiently transfected into HEK293 cells. The luciferase activities of samples were measured to verify the expression of luciferase reporter vector. The expression of atrial natriuretic peptide (ANP), beta-myosin heavy chain (beta-MHC), miR-1 and the Cavbeta 2 mRNA were detected by qRT-PCR. The protein expression of Cavbeta 2 was detected by Western blot. The level of miR-1 was up-regulated by miR-1 mimic transfection and the expression level of Cavbeta 2 was down-regulated by RNAi, then effects of which on cardiomyocyte hypertrophy were investigated.

RESULTS(1) The expression of miR-1 was significantly reduced in cardiomyocyte hypertrophy. Upregulating the miR-1 level could suppress the increase of cell surface area, the expression of ANP and beta-MHC mRNA (P < 0.05). (2) Cavbeta 2 was the one of potential targets of miR-1 by prediction using online database microCosm. The luciferase activities of HEK293 cells with the plasmid containing miR-1 and wide type Cavbeta 3' UTR sequence was significantly decreased when compared with that of control group (P < 0.01). Up-regulation of the miR-1 level could suppress the protein expression of Cavbeta 2. (3) The expression of Cavbeta 2 was significantly increased in cardiomyocyte hypertrophy induced by ISO. Downregulation of Cavbeta by RNAi could markedly inhibit the increase of cell surface area, the expression of ANP and beta-MHC mRNA.

CONCLUSIONCavbeta2 is one of potential targets of miR-1 by bioinformatics prediction. The experiment data confirms that Cavbeta2 is truly the target of miR-1. MiR-1 can negatively regulate the expression of Cavbeta 2, resulting in the decrease of intracellular Ca2+ content and the attenuation of cardiomyocyte hypertrophy.

Animals ; Atrial Natriuretic Factor ; metabolism ; Calcium Channels, L-Type ; genetics ; Cardiomegaly ; genetics ; Gene Expression Regulation ; HEK293 Cells ; Humans ; MicroRNAs ; genetics ; Rats ; Rats, Sprague-Dawley ; Transfection ; Ventricular Myosins ; metabolism

OBJECTIVETo construct the folic acid deficient model in zebrafish and observe the abnormal cardiac phenotypes, to find the optimal period for supplementing folic acid that can most effectively prevent the heart malformation induced by folic acid deficiency, and to investigate the possible mechanisms by which folic acid deficiency induces malformations of heart.

METHODThe folic acid deficient zebrafish model was constructed by using both the folic acid antagonist methotrexate (MTX) and knocking-down dhfr (dihydrofolate reductase gene). Exogenous tetrahydrofolic acid rescue experiment was performed. Folic acid was given to folic acid deficient groups in different periods. The percent of cardiac malformation, the cardiac phenotypes, the heart rate and the ventricular shortening fraction (VSF) were recorded. The out flow tract (OFT) was observed by using fluorescein micro-angiography. Whole-mount in situ hybridization and real-time PCR were performed to detect vmhc, amhc, tbx5 and nppa expressions.

RESULTAbout (78.00 ± 3.74)% embryos in MTX treated group and (68.00 ± 6.32)% embryos in dhfr knocking-down group had heart malformations, including the abnormal cardiac shapes, the hypogenesis of OFT and the reduced heart rate and VSF. Giving exogenous tetrahydrofolic acid rescued the above abnormalities. Given the folic acid on 8 - 12 hours post-fertilization (hpf), both the MTX treated group (20.20% ± 3.77%) and dhfr knocking-down group (43.40% ± 4.51%) showed the most significantly reduced percent of cardiac malformation and the most obviously improved cardiac development. In folic acid deficient group, the expressions of tbx5 and nppa were reduced while the expressions of vmhc and amhc appeared normal. After being given folic acid to MTX treated group and dhfr knocking-down group, the expressions of tbx5 and nppa were increased.

CONCLUSIONSThe synthesis of tetrahydrofolic acid was decreased in our folic acid deficient model. Giving folic acid in the middle period, which is the early developmental stage, can best prevent the abnormal developments of hearts induced by folic acid deficiency. Folic acid deficiency did not disrupt the differentiations of myosins in ventricle and atrium. The cardiac malformations caused by folic acid deficiency were related with the reduced expressions of tbx5 and nppa.

Animals ; Atrial Natriuretic Factor ; metabolism ; Cell Differentiation ; drug effects ; Folic Acid ; metabolism ; Folic Acid Deficiency ; genetics ; metabolism ; Gene Knockdown Techniques ; Heart ; drug effects ; embryology ; growth & development ; T-Box Domain Proteins ; metabolism ; Zebrafish ; embryology ; genetics

To investigate the potential of gene therapy for the treatment of chronic diseases such as hypertension, chronic heart failure, and chronic renal failure, we established the neonatal rat fibroblast line engineered to secrete the mutant human atrial natriuretic peptide (mhANP), and then transplanted the cell line into young spontaneously hypertensive rats (SHR) subcutaneously. We found that a single transplantation of the cell line caused an obvious rise in the concentration of mhANP in serum 7 d after transplantation ((135 +/- 8) vs (106 +/- 7) pg/mL, P < 0.01). The animals' blood pressure in test group was always remarkably lower than that of empty vector group within 42 d after transplantation, even though the blood pressure in all groups was constantly increasing in the process of ontogeny ((175 +/- 10) mm Hg vs (189 +/- 12) mm Hg, P < 0.05). A maximal blood pressure reduction of 33 mm Hg ((157 +/- 9) mm Hg vs (124 +/- 112) mm Hg, P < 0.01) was observed 14 d post cell transplantation. There was a marked increase in urine volume in test group from second week after treatment beginning ((5.9 +/- 0.7) mL/6 h vs (4.3 +/- 0.8) mL/6 h, P < 0.01) and the effect lasted 14 d ((6.1 +/- 1.1) mL/6 h vs (4.0 +/- 0.8) mL/6 h, P < 0.01), however the statistical difference in concentration of K+ and Na+ in serum and urine was not observed. The results suggested that subcutaneous implantation of fibroblasts-expressing mhANP significantly reduced blood pressure in young SHR during the period of ontogeny and efficiently improved their renal function and the somatic gene transfer of mhANP may have potential value in the treatment of human chronic diseases such as hypertension, chronic heart failure, and chronic renal failure.
Animals ; Atrial Natriuretic Factor ; genetics ; physiology ; Cell Line ; Fibroblasts ; cytology ; metabolism ; transplantation ; Gene Expression ; Genetic Therapy ; methods ; Humans ; Hypertension ; genetics ; physiopathology ; therapy ; Male ; Mutation ; Rats ; Rats, Inbred SHR ; Transfection ; Urination

OBJECTIVETo investigate the role of homeobox gene Nkx2-5 in cardiac myogenesis.

METHODSTwo P19 cell lines, namely cells transfected with exogenous expression of Nkx2-5 gene and non-transfected cells, were cultured in suspension for 4 days to induce cell aggregation, and the cell aggregates were transferred to the Petri dish for further adherent culture. On days 4, 8, 12 and 16 of adherent culture, the expressions of α-sarcomeric actin (α-SA) and cardiac troponin T (cTnT) protein were detected by immunocytochemistry, and the mRNA expressions of GATA-4, α-myosin heavy chain (α-MHC) and atrial natriuretic factor (ANF) genes by RT-PCR.

RESULTSIn the transfected cells, α-SA and cTnT protein expressions were detected on days 8, 12 and 16 of adhere culture, and their expressions increased gradually with time. α-SA and cTnT expression was significantly higher on day 16 than on day 8 of culture (P<0.01). RT-PCR analysis of the transfected cell showed the presence of GATA-4 expression on day 4 of adherent culture, and the expression increased on days 8 and 12 but decreased on day 16. ANF and α-MHC expressions were found on days 8, 12, and 16, increasing gradually over time and showing significant differences from those on day 4 (P<0.05 or P<0.01). The expression of α-MHC was significantly higher on days 12 and 16 than on day 8 (P<0.05 or P<0.01), and ANF expression was significantly higher on day 16 than on days 8 and 12 (P<0.01). The non-transfected cells were negative for the expressions of all these genes.

CONCLUSIONExogenous expression of Nkx2-5 gene can induce P19 cells to express cardiac markers in vitro.

Actins ; metabolism ; Animals ; Atrial Natriuretic Factor ; metabolism ; Cell Culture Techniques ; Cell Differentiation ; Cell Line ; GATA4 Transcription Factor ; metabolism ; Gene Expression ; Homeobox Protein Nkx-2.5 ; Homeodomain Proteins ; genetics ; metabolism ; Mice ; Myocytes, Cardiac ; cytology ; metabolism ; Myosin Heavy Chains ; metabolism ; Transcription Factors ; genetics ; metabolism ; Transfection ; Troponin T ; metabolism

BACKGROUNDHypertrophic cardiomyopathy (HCM) is a primary autosomal dominant inheritant myocardial disease with heterogeneity in clinical manifestations, natural history and prognosis. Even carrying an identical gene mutation among family members, a variety of clinical phenotypes have been found in patients with HCM. Modifier genes may contribute to the diversity. The plasma levels of atrial natriuretic peptides (ANP) were found previously to be elevated in HCM. Our studies suggested that ANP gene promoter polymorphism is associated with left ventricular hypertrophy in hypertension. The present study aimed to determine whether the two SNPs in the ANP gene are associated with HCM.

METHODSWe determined the relationships between the ANP gene polymorphism and HCM in 262 HCM patients and 614 age- and sex-matched healthy individuals. All of the subjects were genotyped for -A2843G and A188G polymorphisms.

RESULTSThe genotype frequency in the -A2843G and A188G polymorphisms of the ANP gene was not significantly different between the HCM patients and controls. The -A2843G and A188G polymorphisms were also not associated with clinical phenotype in cardiomyopathy patients.

CONCLUSIONSThe polymorphisms of the ANP gene are not associated with increasing risk of HCM or clinical phenotypes. The variations of the ANP gene may not serve as a genetic modifier for the development of HCM.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Atrial Natriuretic Factor ; genetics ; Cardiomyopathy, Hypertrophic ; genetics ; Case-Control Studies ; Echocardiography ; Female ; Genotype ; Humans ; Linkage Disequilibrium ; Male ; Middle Aged ; Phenotype ; Polymorphism, Genetic ; genetics ; Young Adult