PURPOSE: The expression of natriuretic peptides in the neural bundles of the anterior portion of the optic nerves and their functions in regulating vessel tone and blood flow may suggest a possible role in the pathogenesis of glaucoma. The purpose of this study was to investigate the association between normal-tension glaucoma and the genetic variations of atrial natriuretic peptide (Nppa) and natriuretic peptide receptor A (Npr1) gene. METHODS: Sixty-seven Korean normal-tension glaucoma (NTG) patients and 100 healthy subjects (as normal controls) were enrolled. DNA from peripheral blood leukocytes was extracted, and the genotypes of five polymorphisms (c.94G>A, c.454T>C, IVS1+16C>T, IVS2+701G>A, and c.-764C>G) in the Nppa gene and one polymorphism (c.1023G>C) in the Npr1 gene were determined using the restriction fragment length polymorphism and the SNaPshot methods. The genotype and allele frequencies of these polymorphisms in patients with NTG and normal controls were compared using the Fisher's exact test and the chi-square test. RESULTS: In both groups, the genotype distributions were in accordance with the Hardy-Weinberg equilibrium. There was no significant difference in the frequency of the Nppa and Npr1 alleles or genotypes in the normal-tension glaucoma group as compared to the control group. CONCLUSIONS: Nppa and Npr1 gene polymorphisms are not associated with normal-tension glaucoma, suggesting that this gene does not have an important role in the pathogenesis of optic neuropathy in this disease.
Receptors, Atrial Natriuretic Factor/*genetics ; *Polymorphism, Single Nucleotide ; Middle Aged ; Male ; *Intraocular Pressure ; Humans ; Guanylate Cyclase/*genetics ; Glaucoma/genetics/*physiopathology ; Genotype ; Gene Frequency ; Female ; Atrial Natriuretic Factor/*genetics ; Adult

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

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

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 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

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

A technique based on release of the human atrial natriuretic peptide (hANP) from plasmid hANP cDNA transfected Chinese hamster ovary (CHO) cells encapsulated in polycaprolactone (PCL)-capsules was used for a potential therapeutic approach to hypertension or congestive heart failure (CHF). The plasmid combining with hANP cDNA was transfected into CHO cells, and then encapsulated plasmid hANP cDNA transfected CHO cells were implanted into two-kidney, one-clip (2K1C) hypertensive rats intraperitoneally. The morphological changes, histological changes were investigated after the implantation of PCL-capsules in 2K1C hypertensive rats. The results showed that the implantation of encapsulated hANP-producing cells caused a significant delay of blood pressure (BP) increase after the encapsulated cells being implanted in 2K1C hypertensive rats. These effects were reflected morphologically by an attenuation of the glomerular sclerotic lesions, tubular damage and renal arterial thickening, comparing with control group. The plasma levels of hANP in 2K1C rats implanted with the PCL-capsules containing hANP-producing cells were higher than that of the control rats. These results demonstrated the usefulness of encapsulated hANP gene transfected cells as a new tool for hANP gene delivery in studying renovascular hypertension and cardiovascular diseases, thus implying the potential of using gene transfected cells as therapeutic agents in the treatment of cardiovascular diseases.
Animals ; Atrial Natriuretic Factor ; biosynthesis ; genetics ; therapeutic use ; CHO Cells ; Capsules ; Cell Transplantation ; Cricetinae ; DNA, Complementary ; biosynthesis ; genetics ; Genetic Therapy ; methods ; Humans ; Hypertension, Renovascular ; pathology ; therapy ; Kidney ; pathology ; Male ; Plasmids ; Rats ; Rats, Wistar ; Recombination, Genetic ; Transfection ; Transgenes

OBJECTIVETo investigate the role of endothelin-1 and its receptors on hypertrophy or proliferation of cultured cardial cells.

METHODSCardiomyocytes and cardiac fibroblasts were isolated by trypsin digestion method, DNA and protein synthesis were measured by 3H-dexyribonucleotidethymine (3H-TdR) and 3H-Leucine (3H-Leu) incorporation, while protein content was measured by Bradford method. Atrial natriuretic peptide (ANP) mRNA expression of cardiomyocyte was measured by reverse transcripted-polymerase chain reaction. Selective endothelin (ET) receptor subtype antagonists BQ123 and BQ788 were used to block ET(A) receptors (ET(A)R) and ET(B)R respectively and to observe the effects of the two receptors during cardiac hypertrophy.

RESULTSET-1 significantly increased the 3H-TdR and 3H-Leu incorporation rate of cardiomyocytes and cardiac fibroblasts in a dose-dependent manner and increased protein content. Furthermore, ET-1 promoted the ANP mRNA expression of cardiomyocyte. ET(A)R antagonist remarkably blocked these effects, while ET(B)R antagonist had no obvious effect.

CONCLUSIONSET-1 can induce the hypertrophy for cardiomyocytes and the proliferation for cardiac fibroblasts. These effects are mediated by ET(A)R.

Animals ; Animals, Newborn ; Atrial Natriuretic Factor ; biosynthesis ; genetics ; Cell Proliferation ; Cells, Cultured ; Endothelin-1 ; physiology ; Fibroblasts ; cytology ; pathology ; Hypertrophy ; Myocytes, Cardiac ; cytology ; pathology ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Sprague-Dawley ; Receptor, Endothelin A ; physiology

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