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Morris BJ. Critique of "Sibpair studies implicate chromosome 18 in essential hypertension" by S. Rutherford, M.P. Johnson, and L.R. Griffiths. 2004. Am J Med Genet 126A:241-247. Am J Med Genet A 2005; 132A:456-7; author reply 458-60. [PMID: 15654715 DOI: 10.1002/ajmg.a.30476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Steward LJ, Kennedy MD, Morris BJ, Pratt JA. The atypical antipsychotic drug clozapine enhances chronic PCP-induced regulation of prefrontal cortex 5-HT2A receptors. Neuropharmacology 2005; 47:527-37. [PMID: 15380371 DOI: 10.1016/j.neuropharm.2004.04.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2003] [Revised: 04/16/2004] [Accepted: 04/29/2004] [Indexed: 02/04/2023]
Abstract
The ability of antipsychotic drugs to affect 5-HT(2A) receptor function has been widely suggested to contribute to their therapeutic properties. We have compared the ability of the antipsychotic drugs clozapine and haloperidol, alone and in combination with chronic phencyclidine (PCP), to modulate 5-HT(2A) receptor binding and mRNA. Acute (i.p. 45 min) and chronic (21-day) clozapine (osmotic minipump (OMP); 20 mg/kg/day) produced widespread decreases in 5-HT(2A) receptor binding (-60%-80%), measured using [(3)H]ketanserin autoradiography. Conversely, 5-HT(2A) mRNA levels, determined using in-situ hybridisation, were modestly increased by chronic clozapine treatment (+10%-30%). Chronic PCP treatment, at a dose (2.58 mg/kg i.p. intermittently for 28 days) that reproduces many of the neurochemical deficits of schizophrenia, decreased 5-HT(2A) receptor binding in the prefrontal cortex (PFC; -16%), consistent with the changes in post-mortem brain tissue from schizophrenic patients. Combined chronic PCP (i.p.) and clozapine (OMP) treatment down-regulated 5-HT(2A) receptor binding in many areas, similar to the effects of clozapine treatment alone and clozapine further enhanced the effects of PCP in the prefrontal cortex. In contrast 5-HT(2A) mRNA was not altered. Haloperidol treatment alone (1 mg/kg/day; OMP) and in combination with PCP (i.p.), generally produced no changes in 5-HT(2A) receptor protein or mRNA. Hence chronic PCP treatment, as employed here, mimics the decreased 5-HT(2A) receptor binding observed in the PFC of schizophrenic patients. Clozapine's enhancement of the natural response of PCP to down-regulate PFC 5-HT(2A) receptors may contribute to it's improved therapeutic profile against negative symptoms and cognitive deficits.
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Morris BJ. Cervical human papillomavirus screening by PCR: advantages of targeting the E6/E7 region. Clin Chem Lab Med 2005; 43:1171-7. [PMID: 16232081 DOI: 10.1515/cclm.2005.203] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractPCR is a promising method for detection of human papillomavirus (HPV), the high-risk forms of which are responsible for cervical cancer. PCR primers that target the L1 or E1 region can be unreliable and may miss more advanced disease, whereas those directed at the E6 or E7 regions, which encode oncogenic products, are preferable because 1) the LI/E1 regions, but never the E6/E7 regions, are lost during integration of viral DNA into host genomic DNA, a process that can represent an integral component of progression from infection to tumorigenesis; and 2) the E6/E7 nucleotide sequence exhibits less nucleotide variation. The choice of region used for PCR has implications for HPV screening strategies in the clinical diagnosis and management of cervical cancer.
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Rakhit S, Clark CJ, O'shaughnessy CT, Morris BJ. N-Methyl-D-aspartate and Brain-Derived Neurotrophic Factor Induce Distinct Profiles of Extracellular Signal-Regulated Kinase, Mitogen- and Stress-Activated Kinase, and Ribosomal S6 Kinase Phosphorylation in Cortical Neurons. Mol Pharmacol 2004; 67:1158-65. [PMID: 15625280 DOI: 10.1124/mol.104.005447] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Stimulation of N-methyl-D-aspartate (NMDA) receptors is believed to underlie long-term memory formation, and excessive NMDA receptor activation has been linked to several neuropathological conditions. Phosphorylation and activation of p42/44 mitogen-activated protein kinase (ERK) is believed to mediate many of these effects, but the downstream targets of ERK in response to NMDA activation have not been determined. In primary cultures of rat cortical neurons, we found that NMDA was able to elevate phosphorylation of mitogen- and stress-activated kinase 1 (MSK1) as well as ERK. Likewise, brain-derived neurotrophic factor (BDNF) treatment increased phosphorylation of MSK1 and ERKs. The NMDA-induced MSK1 phosphorylation was sensitive to the MEK inhibitor 2'-amino-3'-methoxyflavone (PD98059) and the p38 inhibitor 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580). MSK1 activation by NMDA was transient, although ERK remained phosphorylated within the neuronal cytoplasm for several hours. Although BDNF increased ribosomal S6 kinase (RSK) phosphorylation, NMDA had no discernable effect on the phosphorylation of RSKs. Thus, phosphorylation and activation of MSK1 but not RSK could be an important step in the pathway linking NMDA-induced ERK phosphorylation to the activation of transcription factors required for the formation of long-term memory.
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Speirs HJL, Katyk K, Kumar NN, Benjafield AV, Wang WYS, Morris BJ. Association of G-protein-coupled receptor kinase 4 haplotypes, but not HSD3B1 or PTP1B polymorphisms, with essential hypertension. J Hypertens 2004; 22:931-6. [PMID: 15097232 DOI: 10.1097/00004872-200405000-00014] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To perform association studies of polymorphisms of the potential candidate essential hypertension (HT) genes GRK4, PTP1B and HSD3B1. METHODS Subjects consisted of 168 unrelated, Caucasian essential hypertensive (HT) patients and 312 normotensive (NT) controls. Biological power was increased by ensuring subjects in each group had parents with the same blood pressure (BP) status as theirs. Three GRK4gamma variants (R65L, A142V and A486V), one HSD3B1 variant (T<---C Leu) and one PTP1B variant (1484insG) were genotyped by polymerase chain reaction and restriction enzyme digestion or by homogenous MassEXTEND Assay. RESULTS The V allele of the A486V variant of GRK4gamma, but not the R65L or A142V variants, showed an association with HT (P = 0.02). The V allele was also associated with an elevation in systolic blood pressure (SBP) (P = 0.002). Although the L65 and the V142 alleles tracked with elevation in diastolic (DBP), this was seen only in male HTs (P = 0.009; P = 0.002, respectively). Haplotype frequencies differed between the HT and NT groups, particularly for the R, V, V haplotype combination of R65L, A142V and A486V, respectively. Neither of the HSD3B1 or PTP1B variants were associated with HT. CONCLUSION Genetic variation in GRK4gamma was associated with HT in the subjects studied.
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Conway AM, James AB, O'Kane EM, Rakhit S, Morris BJ. Regulation of myosin light chain phosphorylation by RhoB in neuronal cells. Exp Cell Res 2004; 300:35-42. [PMID: 15383312 DOI: 10.1016/j.yexcr.2004.06.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2004] [Revised: 06/16/2004] [Indexed: 11/26/2022]
Abstract
The phosphorylation of myosin light chain (MLC) is a key regulatory point in the control of cellular morphology. Evidence suggests that RhoA-a member of the Rho GTPase family-regulates MLC phosphorylation via Rho kinase (ROK). Neurones display subtle alterations in their cytoarchitecture during the synaptic plasticity following high-frequency stimulation. We have recently demonstrated that RhoB, and not RhoA, is activated in neurones by high-frequency stimulation. However, the downstream consequences of RhoB activation in cells are unclear. In this study, we tested the hypothesis that RhoB might stimulate neuronal MLC phosphorylation. Transfection of PC12 cells with constitutively active RhoB increased MLC phosphorylation. Conversely, dominant-negative RhoB vectors reduced MLC phosphorylation. The effect of RhoB was attenuated by pretreatment with a selective ROK inhibitor. This confirms that Rho GTPases are important regulators of MLC phosphorylation, but suggests that, in neuronal cells, the control is exerted via RhoB rather than RhoA.
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Morris BJ, Adams DJ, Beveridge DJ, van der Weyden L, Mangs H, Leedman PJ. cAMP controls human renin mRNA stability via specific RNA-binding proteins. ACTA ACUST UNITED AC 2004; 181:369-73. [PMID: 15283747 DOI: 10.1111/j.1365-201x.2004.01307.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is now recognized that post-transcriptional mechanisms are pivotal to renin production. These involve factors that modulate renin mRNA stability. In 2003 new data has emerged from work in Australia and Germany that has identified several of the, as many as, 20 or so proteins involved. These include CP1 (hnRNP E1), HuR, HADHB, dynamin, nucleolin, YP-1, hnRNP K and MINT-homologous protein. Cyclic AMP (cAMP) is a crucial regulator of renin secretion as well as transcriptional and post-transcriptional control of expression. Many of the RNA-binding proteins that were identified responded to forskolin, increasing in amount by two to 10-fold. The cAMP mechanisms that regulate renin mRNA target, at least in large part, other genes that presumably encode some of these proteins. The increase in the expression of these then facilitates, sequentially, renin mRNA stabilization and destabilization. Our data, using a battery of different techniques, confirm that CP1 and HuR stabilize renin mRNA, whereas HADHB causes destabilization. These proteins target cis-acting C-rich sequences (in the case of CP1) and AU-rich sequences (HuR) in the distal region of the 3'-untranslated region of renin mRNA. We found HADHB was enriched in juxtaglomerular cells and that that within Calu-6 cells HADHB, HuR and CP1 all localized in nuclear subregions, as well as cytoplasm (HADHB and CP1) and mitochondria (HADHB) commensurate with the role each plays in control of renin mRNA stability. The specific proteins that bind to human renin mRNA have begun to be revealed. Cyclic AMP upregulates the binding of several of these proteins, which in turn affect renin mRNA stability and thus overall expression of renin.
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Benjafield AV, Wang WYS, Morris BJ. No association of angiotensin-converting enzyme 2 gene (ACE2) polymorphisms with essential hypertension. Am J Hypertens 2004; 17:624-8. [PMID: 15233982 PMCID: PMC7110370 DOI: 10.1016/j.amjhyper.2004.02.022] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2003] [Accepted: 02/26/2004] [Indexed: 01/21/2023] Open
Abstract
Recent intriguing findings from genetic linkage, knockout, and physiologic studies in mice and rats led us to conduct the first investigation of the novel angiotensin-converting enzyme 2 gene (ACE2) in human hypertension (HT). We genotyped four single nucleotide polymorphisms (SNP) (A→G at nucleotide 1075 in intron 1, G→A at nucleotide 8790 in intron 3, C→G at nucleotide 28330 in intron 11, and G→C at nucleotide 36787 in intron 16) in HT (n = 152) and normotensive (NT, n = 193) groups having inherently high biological power (>80%) due to our inclusion only of subjects whose parents had the same BP status as themselves. The SNPs were in linkage disequilibrium (D′ = 54% to 100%, P = .05 to 0.0001). Because ACE2 is on the X chromosome, data for each sex were analyzed separately. Minor allele frequencies in HT versus NT were as follows: for the intron 1 variant 0.21 versus 0.17 in female subjects (P = .31) and 0.25 versus 0.29 in male subjects (P = .60); intron 3 variant 0.22 versus 0.18 in female subjects (P = .35) and 0.15 versus 0.20 in male subjects (P = .47); intron 11 variant 0.39 versus 0.46 in male subjects (P = 0.17) and 0.31 versus 0.30 in male subjects (P = .96); intron 16 variant 0.20 versus 0.19 in female subjects (P = .72) and 0.17 versus 0.17 in male subjects (P = .95). Haplotype analysis was also negative. These data provide little support for ACE2 in genetic predisposition to HT.
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O'Kane EM, Stone TW, Morris BJ. Increased long-term potentiation in the CA1 region of rat hippocampus via modulation of GTPase signalling or inhibition of Rho kinase. Neuropharmacology 2004; 46:879-87. [PMID: 15033347 DOI: 10.1016/j.neuropharm.2003.11.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2003] [Revised: 11/10/2003] [Accepted: 11/20/2003] [Indexed: 11/20/2022]
Abstract
There is accumulating evidence that Ras, and Ras-related GTPases of the Rho family, such as RhoA, RhoB and Rac1, are involved in synaptic plasticity in brain regions such as the hippocampus. We have recently shown that Rho family GTPases are activated by synaptic transmission in the CA1 region of the hippocampus. Since the function of these GTPases is dependent on post-translational isoprenylation by either farnesyl or geranylgeranyl transferases, we tested the hypothesis that inhibition of isoprenylation would modify long-term potentiation (LTP). Farnesyl transferase inhibition, which suppressed activation of RhoB and Ras but not RhoA or Rac1, reduced the magnitude of LTP, while geranylgeranyl transferase inhibition, which inhibited RhoA and Rac1 but not RhoB, increased the magnitude of LTP. In addition, Y-27632, a specific inhibitor of a downstream effector of Rho GTPases-Rho-kinase-also increased the magnitude of LTP. This provides strong evidence that GTPases are important mediators of synaptic plasticity, and demonstrates that Rho-kinase acts to reduce the degree of plasticity at hippocampal synapses during LTP. Rho-kinase inhibitors have the unusual property of increasing the magnitude of LTP, and so may be potential cognitive enhancers.
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Blessing EM, Solomon SG, Hashemi-Nezhad M, Morris BJ, Martin PR. Chromatic and spatial properties of parvocellular cells in the lateral geniculate nucleus of the marmoset (Callithrix jacchus). J Physiol 2004; 557:229-45. [PMID: 15047769 PMCID: PMC1665047 DOI: 10.1113/jphysiol.2003.058065] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2003] [Accepted: 03/24/2004] [Indexed: 11/08/2022] Open
Abstract
The parvocellular (PC) division of the afferent visual pathway is considered to carry neuronal signals which underlie the red-green dimension of colour vision as well as high-resolution spatial vision. In order to understand the origin of these signals, and the way in which they are combined, the responses of PC cells in dichromatic ('red-green colour-blind') and trichromatic marmosets were compared. Visual stimuli included coloured and achromatic gratings, and spatially uniform red and green lights presented at varying temporal phases and frequencies.The sensitivity of PC cells to red-green chromatic modulation was found to depend primarily on the spectral separation between the medium- and long-wavelength-sensitive cone pigments (20 or 7 nm) in the two trichromatic marmoset phenotypes studied. The temporal frequency dependence of chromatic sensitivity was consistent with centre-surround interactions. Some evidence for chromatic selectivity was seen in peripheral PC cells. The receptive field dimensions of parvocellular cells were similar in dichromatic and trichromatic animals, but the achromatic contrast sensitivity of cells was slightly higher (by about 30%) in dichromats than in trichromats. These data support the hypothesis that the primary role of the PC is to transmit high-acuity spatial signals, with red-green opponent signals appearing as an additional response dimension in trichromatic animals.
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Abstract
A polymorphism in intron 10 of the serine-threonine kinase with no lysine (K) 4 gene WNK4 (G-->A, base 1156666 on chromosome 17) has recently been associated with essential hypertension in a white American population. We have attempted to replicate this finding in a well characterized cohort of 184 unrelated hypertensive Australians of British extraction in which biological power was enhanced by them each having 2 hypertensive parents. Controls were 219 normotensive ethnically matched subjects whose parents were both normotensive. Genotyping was performed using the homogeneous MassEXTEND Assay. This showed a frequency of 0.10 for the minor allele in each group (P=0.88). Moreover, blood pressure, body mass index, sex, and plasma lipid levels were similar across genotypes. In conclusion, our study provides no support for an association of the intron 10 variant of WNK4 with essential hypertension in the Anglo-Australian population studied.
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Alier KA, Morris BJ. Differential regulation of MAP2 and αCamKII expression in hippocampal neurones by forskolin and calcium ionophore treatment. ACTA ACUST UNITED AC 2004; 122:10-6. [PMID: 14992811 DOI: 10.1016/j.molbrainres.2003.11.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/19/2003] [Indexed: 10/26/2022]
Abstract
The genes encoding microtubule-associated protein 2 (MAP2), and the alpha subunit of calcium/calmodulin-dependent protein kinase II (alphaCaMKII), are members of a small number of genes whose expression is increased in hippocampal neurones during the intermediate phase of long-term potentiation (LTP)-a phase dependent on mRNA translation but not on gene transcription. However, the intracellular signalling pathways which mediate these increases in expression are largely unknown. Organotypic slice cultures of rat hippocampus were exposed to either forskolin (to elevate cAMP levels), A23187 (to increase intracellular Ca(2+) levels) or the corresponding vehicle. The levels of immunoreactive (ir-) MAP2 were increased 4 h after forskolin treatment, but were unaffected by A23187 treatment. Conversely, the levels of ir-alphaCaMKII were increased 4 h after A23187 treatment, but were unaffected by forskolin. The regulation of the expression of these proteins was the same in the CA3 region as in the CA1 and dentate gyrus of the hippocampus. While rapamycin reduced the basal levels of ir-MAP2, it did not affect the ability of either forskolin or A23187 to enhance ir-MAP2 or ir-alphaCaMKII levels. These results suggest that cAMP and Ca(2+) differentially modulate the expression of these two plasticity-related genes, and that translational enhancement via the mammalian target of rapamycin kinase is not involved in these effects.
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Adams DJ, Beveridge DJ, van der Weyden L, Mangs H, Leedman PJ, Morris BJ. HADHB, HuR, and CP1 bind to the distal 3'-untranslated region of human renin mRNA and differentially modulate renin expression. J Biol Chem 2003; 278:44894-903. [PMID: 12933794 DOI: 10.1074/jbc.m307782200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Production of renin is critically dependent on modulation of REN mRNA stability. Here we sought to elucidate the molecular mechanisms involved. Transfections of renin-expressing Calu-6 cells with reporter constructs showed that a cis-acting 34-nucleotide AU-rich "renin stability regulatory element" in the REN 3'-untranslated region (3'-UTR) contributes to basal REN mRNA instability. Yeast three-hybrid screening with the REN 3'-UTR as bait isolated HADHB (hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase/enoyl-CoA hydratase (trifunctional protein) beta-subunit) as a novel REN mRNA-binding protein. Recombinant HADHB bound specifically to the 3'-UTR of REN mRNA, as did the known mRNA stabilizers HuR and CP1 (poly(C)-binding protein-1). This required the renin stability regulatory element. Forskolin, which augments REN mRNA stability in Calu-6 cells, increased binding of several proteins, including HuR and CP1, to the REN 3'-UTR, whereas 4-bromocrotonic acid, a specific thiolase inhibitor, decreased binding and elevated renin protein levels. Upon decreasing HADHB mRNA with RNA interference, renin protein and mRNA stability increased, whereas RNA interference against HuR caused these to decrease. Immunoprecipitation and reverse transcription-PCR of Calu-6 extracts confirmed that HADHB, HuR, and CP1 each associate with REN mRNA in vivo. Intracellular imaging revealed distinct localization of HADHB to mitochondria, HuR to nuclei, and CP1 throughout the cell. Immunohistochemistry demonstrated enrichment of HADHB in renin-producing renal juxtaglomerular cells. In conclusion, HADHB, HuR, and CP1 are novel REN mRNA-binding proteins that target a cis-element in the 3'-UTR of REN mRNA and regulate renin production. cAMP-mediated increased REN mRNA stability may involve stimulation of HuR and CP1, whereas REN mRNA decay may involve thiolase-dependent pathways.
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Abstract
Ras-related GTPases of the Rho family, such as RhoA and RhoB, are well-characterised mediators of morphological change in peripheral tissues via their effects on the actin cytoskeleton. We tested the hypothesis that Rho family GTPases are involved in synaptic transmission in the CA1 region of the hippocampus. We show that GTPases are activated by synaptic transmission. RhoA and RhoB were activated by low frequency stimulation, while the induction of long-term potentiation (LTP) by high frequency stimulation was associated with specific activation of RhoB via NMDA receptor stimulation. This illustrates that these GTPases are potential mediators of synaptic transmission in the hippocampus, and raises the possibility that RhoB may play a role in plasticity at hippocampal synapses during LTP.
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Benjafield AV, Katyk K, Morris BJ. Association of EDNRA
, but not WNK4
or FKBP1B
, polymorphisms with essential hypertension. Clin Genet 2003; 64:433-8. [PMID: 14616768 DOI: 10.1034/j.1399-0004.2003.00148.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In a study of the genetic basis of essential hypertension (HT), we tested four variants in three candidate genes not previously investigated in HT. These encoded the endothelin receptor type A (EDNRA), which transduces most of the vasoconstrictive properties of endothelin-1, protein kinase lysine deficient 4 (WNK4) whose gene resides in a HT linkage region on chromosome 17, and FK506-binding protein 1B (FKBP1B), which can reduce blood pressure by increasing nitric oxide. The variants were: for EDNRA, a G-->A in the 5'-UTR and C-->T in exon 8; for WNK4, a tetranucleotide repeat in intron 10; and for FKBP1B, a T-->C in exon 4. Subjects were Anglo-Celtic white Australians and included 155 HTs with two HT parents and 245 normotensives (NTs) whose parents were both NT. For EDNRA, we found a weak association of the exon 8 variant with HT (p = 0.019) and association of the 5'-UTR variant with elevation in systolic and diastolic blood pressure (BP) (p = 0.038 and 0.0031, respectively). The WNK4 intron 10 variant and the FKP1B exon 4 variant showed no association with HT, but tracking with BP was seen for the latter (p = 0.015 and 0.0011 for systolic and diastolic BP, respectively). Our study thus suggests possible involvement of EDNRA in essential HT.
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Lin RCY, Schyvens CG, Zhang Y, Whitworth JA, Morris BJ. Tumor necrosis factor receptor 2 mRNA in rat models of hypertension. Am J Hypertens 2003; 16:685-8. [PMID: 12878376 DOI: 10.1016/s0895-7061(03)00916-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In human hypertension (HT) plasma tumor necrosis factor (TNF-alpha) and soluble TNF receptor 2 fragment (sTNF-R2) are increased, and the TNF-R2 gene (TNFRSF1B) has been implicated. Therefore, we measured Tnfr2 mRNA in kidney, adrenal, heart, and aorta from rats with ACTH-induced, corticosterone-induced, and spontaneous HT (SHR), and tested the effect of blockade of TNF-alpha by a recombinant TNF-R2 fragment (huTNFR:Fc) on development of HT in the ACTH model. Tnfr2 mRNA was quantified by real-time polymerase chain reaction, as were internal controls, beta-actin, and glyceraldehyde-3-phosphate dehydrogenase mRNA. The results showed no differences in tissue Tnfr2 mRNA between HT and control rats. The ACTH-induced HT was not affected by huTNFR:Fc coadministration. The findings thus offer no support for altered Tnfr2 expression in the rat models studied.
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MESH Headings
- Adrenocorticotropic Hormone
- Animals
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Blood Pressure/physiology
- Corticosterone
- Hypertension/chemically induced
- Hypertension/genetics
- Hypertension/metabolism
- Male
- RNA, Messenger/biosynthesis
- Rats
- Rats, Inbred SHR
- Rats, Inbred WKY
- Rats, Sprague-Dawley
- Receptors, Tumor Necrosis Factor/biosynthesis
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor, Type II
- Reverse Transcriptase Polymerase Chain Reaction
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Kumar NN, Benjafield AV, Lin RC, Wang WY, Stowasser M, Morris BJ. Haplotype analysis of aldosterone synthase gene (CYP11B2) polymorphisms shows association with essential hypertension. J Hypertens 2003; 21:1331-7. [PMID: 12817181 DOI: 10.1097/00004872-200307000-00022] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The CYP11B2 locus is an important candidate region in essential hypertension (HT). We therefore investigated CYP11B2 polymorphisms T-344C, T4986C and A6547G for association with essential HT. This included haplotype analysis and measurement of plasma aldosterone levels. METHODS The three single nucleotide polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis of genomic DNA from 146 HT and 291 normotensive (NT) white subjects of Anglo-Celtic descent, in whom parental blood pressure status was the same as the subjects'. Genotype and allele frequencies in HTs and NTs were compared by chi2 analysis. Linkage disequilibrium and haplotype frequencies were estimated by the program 'snphap'. Phenotype-genotype relationships were tested using one-way analysis of variance. RESULTS The T-344C variant was associated with HT (chi2 = 7.4, P = 0.0064). This association was confined to female HTs (P = 0.0061 for genotypes, P = 0.0013 for alleles). A strong association with HT was also seen for the A6547G variant (P = 0.0015), being greatest in females (P < 0.0001). No association was seen for the T4986C variant. Haplotype analysis of the three single nucleotide polymorphisms across eight different haplotype combinations showed a significant association with HT (chi2 = 24, seven degrees of freedom, P < 0.001). No significant tracking of plasma aldosterone with genotype was observed. CONCLUSION The T-344C and A6547G, but not the T4986C, variants of the aldosterone synthase gene are associated with HT in females of the Anglo-Celtic population studied. This was reinforced by haplotype analysis.
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Abstract
Herein we review all of the data from linkage by genome scanning and from association studies in essential hypertension. Genome scans have yielded loci linked to hypertension on almost every chromosome. We tabulate all of these loci to highlight the striking inconsistency. Similarly, association studies have implicated > 66 genes to date, which we also list, but virtually all have failed to show consistent replication in other settings. Nevertheless, we believe that molecular genetics should eventually find all of the major gene variants for essential hypertension. This will be a great scientific achievement and lead to new treatments. The dream, however, of using this information in clinical genetic testing could turn out to be a nightmare. Thus at present the hype surrounding genes for complex polygenic diseases like hypertension far exceeds the reality.
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McDermott CJ, Bradley KN, McCarron JG, Palmer AM, Morris BJ. Striatal neurones show sustained recovery from severe hypoglycaemic insult. J Neurochem 2003; 86:383-93. [PMID: 12871579 DOI: 10.1046/j.1471-4159.2003.01853.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Glucose deprivation provides a reliable model to investigate cellular responses to metabolic dysfunction, and is reportedly associated with permanent cell death in many paradigms. Consistent with previous studies, primary cultures of rat striatal neurones exposed to 24-h hypoglycaemia showed dramatically decreased sodium 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) metabolism (used as a marker of cell viability) and increased TUNEL staining, suggesting widespread DNA damage typical of apoptotic cell death. Remarkably, restoration of normal glucose levels initiated a sustained recovery in XTT staining, along with a concomitant decrease in TUNEL staining, even after 24 h of hypoglycaemia, suggesting recovery of damaged neurones and repair of nicked DNA. No alterations in the levels of four DNA repair proteins could be detected during hypoglycaemia or recovery. A reduction in intracellular calcium concentration was seen in recovered cells. These data suggest that striatal cells do not die after extended periods of glucose deprivation, but survive in a form of suspended animation, with sufficient energy to maintain membrane potential.
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Plambeck CA, Kwan AHY, Adams DJ, Westman BJ, van der Weyden L, Medcalf RL, Morris BJ, Mackay JP. The structure of the zinc finger domain from human splicing factor ZNF265 fold. J Biol Chem 2003; 278:22805-11. [PMID: 12657633 DOI: 10.1074/jbc.m301896200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Identification of the protein domains that are responsible for RNA recognition has lagged behind the characterization of protein-DNA interactions. However, it is now becoming clear that a range of structural motifs bind to RNA and their structures and molecular mechanisms of action are beginning to be elucidated. In this report, we have expressed and purified one of the two putative RNA-binding domains from ZNF265, a protein that has been shown to bind to the spliceosomal components U1-70K and U2AF35 and to direct alternative splicing. We show that this domain, which contains four highly conserved cysteine residues, forms a stable, monomeric structure upon the addition of 1 molar eq of Zn(II). Determination of the solution structure of this domain reveals a conformation comprising two stacked beta-hairpins oriented at approximately 80 degrees to each other and sandwiching the zinc ion; the fold resembles the zinc ribbon class of zinc-binding domains, although with one less beta-strand than most members of the class. Analysis of the structure reveals a striking resemblance to known RNA-binding motifs in terms of the distribution of key surface residues responsible for making RNA contacts, despite a complete lack of structural homology. Furthermore, we have used an RNA gel shift assay to demonstrate that a single crossed finger domain from ZNF265 is capable of binding to an RNA message. Taken together, these results define a new RNA-binding motif and should provide insight into the functions of the >100 uncharacterized proteins in the sequence data bases that contain this domain.
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Morris BJ. Circumcision for phimosis and other medical indications in Western Australian boys. Med J Aust 2003; 178:588-9; author reply 589-90. [PMID: 12830813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
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Lin RCY, Wang XL, Dalziel B, Caterson ID, Morris BJ. Association of obesity, but not diabetes or hypertension, with glucocorticoid receptor N363S variant. OBESITY RESEARCH 2003; 11:802-8. [PMID: 12805402 DOI: 10.1038/oby.2003.111] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To determine whether the N363S variant in the glucocorticoid receptor (encoded by nuclear receptor subfamily 3, group C, member 1: NR3C1) is associated with obesity, type 2 diabetes, or hypertension. RESEARCH METHODS AND PROCEDURES This was a cross-sectional case-control study involving 951 Anglo-Celtic/Northern European subjects from Sydney. This study consisted of the following: 1) an obesity clinic group, most of whom had "morbid obesity" (mean BMI for group = 43 +/- 8 kg/m(2); n = 152); 2) a type 2 diabetes clinic group (n = 356); 3) patients with essential hypertension who had a strong family history (n = 141); and 4) normal healthy controls (n = 302). N363S genotype, BMI, and a range of other parameters relevant to each group were measured. RESULTS Compared with the frequency of 0.04 in nonobese healthy subjects, the S363 allele was significantly higher in obesity clinic patients (0.17; p = 5.6 x 10(-8)), subjects with diabetes who were also obese (0.09; p = 0.0045), subjects with hypertension who were also overweight (0.08; p = 0.0016), and overweight healthy subjects (0.12; p = 0.0004). DISCUSSION The NR3C1 N363S variant is associated with obesity and overweight in a range of patient settings but is not associated with hypertension or type 2 diabetes.
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