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Hypertension induced by highsalt diet in Dahl salt-sensitive rats leads to compensatory cardiac hypertrophy by ~11 wk, cardiac dysfunction at ~17 wk, and death from cardiac dysfunction at ~21 wk. It is unclear what molecular hallmarks distinguish the compensatory hypertrophy from the decompensated cardiac dysfunction phase. Here we compared the gene expression in rat cardiac tissue from the compensatory hypertrophic phase (11 wk, n = 6) with the cardiac dysfunction phase (17 wk, n = 6) and with age-matched normotensive controls. Messenger RNA levels of 93 genes, selected based on predicted association with cardiac dysfunction, were measured by quantitative real-time PCR. In the hypertrophic phase, the expression of three genes, atrial natriuretic peptide (ANP; P = 0.0089), brain natriuretic peptide (P = 0.0012), and endothelin-1 precursor (P = 0.028), significantly increased, whereas there was decreased expression of 24 other genes including SOD2 (P = 0.0148), sarco(endo)plasmic reticulum [Ca.sup.2+]-ATPase 2a (P = 0.0002), and ryanodine receptor 2 (P = 0.0319). In the subsequent heart cardiac dysfunction phase, the expression of an additional 20 genes including inducible nitric oxide synthase (NOS; P = 0.0135), angiotensin I-converting enzyme (P = 0.0082), and IL-1[beta] (P < 0.0001) increased, whereas the expression of seven genes decreased compared with those of age-matched controls. Furthermore, the expression of 22 genes, including prepro-endothelin-1, ANP, angiotensin I-converting enzyme, [[beta].sub.1]-adrenergic receptor, SOD2, and endothelial NOS, significantly changed in the cardiac dysfunction phase compared with the compensatory hypertrophic phase. Finally, principal component analysis successfully segregated animals with decompensatory cardiac dysfunction from controls, as well as from animals at the compensated hypertrophy phase, suggesting that we have identified molecular markers for each stage of the disease. quantitative polymerase chain reaction; diagnosis; heart failure; left ventricular

Activity of voltage-gated [K.sup.+] ([K.sub.v]) channels in pulmonary artery smooth muscle cells (PASMC) plays an important role in control of apoptosis and proliferation in addition to regulating membrane potential and pulmonary vascular tone. Bone morphogenetic proteins (BMPs) inhibit proliferation and induce apoptosis in normal human PASMC, whereas dysfunctional BMP signaling and downregulated [K.sub.v] channels are involved in pulmonary vascular medial hypertrophy associated with pulmonary hypertension. This study evaluated the effect of BMP-2 on [K.sub.v] channel function and expression in normal human PASMC. BMP-2 (100 nM for 18-24 h) significantly (>2-fold) upregulated mRNA expression of KCNA5, KCNA7, KCNA10, KCNC3, KCNC4, KCNF1, KCNG3, KCNS1, and KCNS3 but downregulated (at least 2-fold) KCNAB1, KCNA2, KCNG2, and KCNV2. The most dramatic change was the >10-fold downregulation of KCNG2 and KCNV2, two electrically silent [gamma]-subunits that form heterotetramers with functional [K.sub.v] channel [alpha]-subunits (e.g., KCNB1-2). Furthermore, the amplitude and current density of whole cell [K.sub.v] currents were significantly increased in PASMC treated with BMP-2. It has been demonstrated that [K.sub.+] currents generated by KCNB1 and KCNG1 (or KCNG2) or KCNB1 and KCNV2 heterotetramers are smaller than those generated by KCNB1 homotetramers, indicating that KCNG2 and KCNV2 (2 subunits that were markedly downregulated by BMP-2) are inhibitors of functional [K.sub.v] channels. These results suggest that BMP-2 divergently regulates mRNA expression of various [K.sub.v] channel [alpha]-, [beta]-, and [gamma]-subunits and significantly increases whole cell [K.sub.v] currents in human PASMC. Finally, we present evidence that attenuation of c-Myc expression by BMP-2 may be involved in BMP-2-mediated increase in [K.sub.v] channel activity and regulation of [K.sub.v] channel expression. The increased [K.sub.v] channel activity may be involved in the proapoptotic and/or antiproliferative effects of BMP-2 on PASMC. pulmonary arterial hypertension; patch clamp; membrane potential

In recent years, researchers have made great strides toward understanding the role of endogenous small RNAs (miRNAs) in gene regulation and harnessing the power of exogenous small RNAs (siRNAs and [...]

Research has been conducted on the nonregular heteropyrimidine sequence oligonucleotides that can form self-associated parallel-stranded structures. The identification of these structures via neutral and acidic pH UV melting transitions and other methods has been carried out.

Activity of voltage-gated K+ (Kv) channels in pulmonary artery smooth muscle cells (PASMC) plays an important role in control of apoptosis and proliferation in addition to regulating membrane potential and pulmonary vascular tone. Bone morphogenetic proteins (BMPs) inhibit proliferation and induce apoptosis in normal human PASMC, whereas dysfunctional BMP signaling and downregulated Kv channels are involved in pulmonary vascular medial hypertrophy associated with pulmonary hypertension. This study evaluated the effect of BMP-2 on Kv channel function and expression in normal human PASMC. BMP-2 (100 nM for 18–24 h) significantly (>2-fold) upregulated mRNA expression of KCNA5, KCNA7, KCNA10, KCNC3, KCNC4, KCNF1, KCNG3, KCNS1, and KCNS3 but downregulated (at least 2-fold) KCNAB1, KCNA2, KCNG2, and KCNV2. The most dramatic change was the >10-fold downregulation of KCNG2 and KCNV2, two electrically silent γ-subunits that form heterotetramers with functional Kv channel α-subunits (e.g., KCNB1-2). Furthermore, the amplitude and current density of whole cell Kv currents were significantly increased in PASMC treated with BMP-2. It has been demonstrated that K+ currents generated by KCNB1 and KCNG1 (or KCNG2) or KCNB1 and KCNV2 heterotetramers are smaller than those generated by KCNB1 homotetramers, indicating that KCNG2 and KCNV2 (2 subunits that were markedly downregulated by BMP-2) are inhibitors of functional Kv channels. These results suggest that BMP-2 divergently regulates mRNA expression of various Kv channel α-, β-, and γ-subunits and significantly increases whole cell Kv currents in human PASMC. Finally, we present evidence that attenuation of c-Myc expression by BMP-2 may be involved in BMP-2-mediated increase in Kv channel activity and regulation of Kv channel expression. The increased Kv channel activity may be involved in the proapoptotic and/or antiproliferative effects of BMP-2 on PASMC. [ABSTRACT FROM AUTHOR]

The efficiency of cleavage of DNA duplexes with single EcoRII recognition sites by the EcoRII restriction endonuclease decreases with increasing substrate length. DNA duplexes of more than 215 bp are not effectively cleaved by this enzyme. Acceleration of the hydrolysis of long single-site substrates by EcoRII is observed in the presence of 11–14-bp substrates. The stimulation of hydrolysis depends on the length and concentration of the second substrate. To study the mechanism of EcoRII endonuclease stimulation, DNA duplexes with base analogs and modified internucleotide phosphate groups in the EcoRII site have been investigated as activators. These modified duplexes are cleaved by EcoRII enzyme with different efficiences or are not cleaved at all. It has been discovered that the resistance of some of them can be overcome by incubation with a susceptible canonical substrate. The acceleration of cleavage of long single-site substrates depends on the type of modification of the activator. The modified DNA duplexes can activate EcoRII catalyzed hydrolysis if they can be cleaved by EcoRII themselves or in the presence of the second canonical substrate. It has been demonstrated that EcoRII endonuclease interacts in a cooperative way with two recognition sites in DNA. The cleavage of one of the recognition sites depends on the cleavage of the other. We suggest that the activator is not an allosteric effector but acts as a second substrate. [ABSTRACT FROM AUTHOR]