1
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Liu J, Wei B, Zhang Y, You Y, Zhi Y. Association between PRKG1 Gene and Gene-Environment Interactions with Pediatric Asthma. J Asthma 2024:1-13. [PMID: 38193459 DOI: 10.1080/02770903.2024.2303763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 01/07/2024] [Indexed: 01/10/2024]
Abstract
OBJECTIVE To investigate the relationship between single nucleotide polymorphisms (SNPs) of cGMP-dependent protein kinase I (PRKG1) gene and gene-environment interactions with bronchial asthma in children. METHODS 109 asthma patients and 158 healthy controls from the General Hospital of Northern Theater Command were enrolled, based case-control study. The iMLDR® multiple SNP typing technique was applied to detect the genotypes of rs7903366, rs7081864, rs7070958 and rs7897633 in PRKG1 gene. The percentage of eosinophils (EOS%) in peripheral blood and serum immunoglobulin E (IgE) in the case group were also measured. Gene-environment interactions were examined using the generalized multi-factor dimensionality reduction (GMDR) method. RESULTS There were polymorphisms in four SNPs of PRKG1 gene in the case and control groups. The genotype and allele frequencies distribution of rs7897633 demonstrated statistical significance (p < 0.05). There were no statistically significant differences in EOS% and IgE among genotypes at the four SNPs of PRKG1 gene (p > 0.05). The haplotypes CAGA and TGAC presented significant association with asthma risk (p < 0.05). The four-factor model indicated a potential gene-environment interaction in rs7897633, allergen exposure, residence, and environmental tobacco smoke (ETS) exposure (p < 0.05). CONCLUSIONS The rs7897633 in PRKG1 gene was associated with susceptibility to childhood asthma, and C allele is a protective factor. The haplotype CAGA had a protective effect against asthma risk and TGAC was linked to the high risk of developing asthma. Moreover, the interaction of rs7897633, allergen exposure, residence, and ETS exposure conferred susceptibility to childhood asthma.
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Affiliation(s)
- Jun Liu
- Department of Neonatology, General Hospital of Northern Theater Command, Shenyang, P.R. China
- Post-graduate College, China Medical University, Shenyang, P.R. China
| | - Bing Wei
- Department of Neonatology, General Hospital of Northern Theater Command, Shenyang, P.R. China
| | - Yuxuan Zhang
- Department of Neonatology, General Hospital of Northern Theater Command, Shenyang, P.R. China
| | - Yuan You
- Department of Neonatology, General Hospital of Northern Theater Command, Shenyang, P.R. China
| | - Yanjie Zhi
- Department of Neonatology, General Hospital of Northern Theater Command, Shenyang, P.R. China
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2
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Zhang W, Han Q, Liu Z, Zhou W, Cao Q, Zhou W. Exome sequencing reveals a de novo PRKG1 mutation in a sporadic patient with aortic dissection. BMC MEDICAL GENETICS 2018; 19:218. [PMID: 30577811 PMCID: PMC6303953 DOI: 10.1186/s12881-018-0735-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 12/13/2018] [Indexed: 11/24/2022]
Abstract
Background Thoracic aortic aneurysm and dissection (TAAD) is a common condition associated with high mortality. It is predominantly inherited in an autosomal dominant manner with reduced penetrance and variable expression. The genetic basis of the majority of TAAD cases remains unknown. Case presentation We described a 53 years old male presented with abdominal aortic dissection as well as aortic tortuosity. To investigate the genetic basis of the clinical presentation, whole-exome sequencing was performed. Exome sequencing identified a de novo heterozygous undescribed mutation in the PRKG1 gene (NM_001098512.2: c.1108 G > A), predicted to cause the missense change p.Gly370Ser in the ATP binding motif of the protein. This mutation was not reported in the dbSNP, 1000 Genome Project, and Exome sequencing databases. Furthermore, the Glycine370 residue of PRKG1 is highly conserved among various species and it is predicted to be damaging by multiple in silico programs, suggesting that this substitution may cause a major disruption of protein function. To our knowledge, this is the second reported mutation locus of PRKG1 accounting for the disease. Conclusions Our study expands the mutation spectrum of PRKG1 and clinical phenotype of mutation-carriers. Screening for PRKG1 mutations should be considered in patients with unexplained aortic disease, and identification of the causative gene will aid in individualized, gene-tailored management.
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Affiliation(s)
- Wenwen Zhang
- Department of Vascular Surgery, The Second Affiliated Hospital of Nanchang University, No 1#, Minde Road, Nanchang, China.,Key Laboratory of Molecular Medicine of Jiangxi Province, Nanchang, Jiangxi, China
| | - Qian Han
- Department of Vascular Surgery, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Zhao Liu
- Department of Vascular Surgery, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Wei Zhou
- Department of Vascular Surgery, The Second Affiliated Hospital of Nanchang University, No 1#, Minde Road, Nanchang, China
| | - Qing Cao
- Key Laboratory of Molecular Medicine of Jiangxi Province, Nanchang, Jiangxi, China
| | - Weimin Zhou
- Department of Vascular Surgery, The Second Affiliated Hospital of Nanchang University, No 1#, Minde Road, Nanchang, China.
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3
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Spear ML, Hu D, Pino-Yanes M, Huntsman S, Eng C, Levin AM, Ortega VE, White MJ, McGarry ME, Thakur N, Galanter J, Mak ACY, Oh SS, Ampleford E, Peters SP, Davis A, Kumar R, Farber HJ, Meade K, Avila PC, Serebrisky D, Lenoir MA, Brigino-Buenaventura E, Cintron WR, Thyne SM, Rodriguez-Santana JR, Ford JG, Chapela R, Estrada AM, Sandoval K, Seibold MA, Winkler CA, Bleecker ER, Myers DA, Williams LK, Hernandez RD, Torgerson DG, Burchard EG. A genome-wide association and admixture mapping study of bronchodilator drug response in African Americans with asthma. THE PHARMACOGENOMICS JOURNAL 2018; 19:249-259. [PMID: 30206298 PMCID: PMC6414286 DOI: 10.1038/s41397-018-0042-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 06/08/2018] [Accepted: 06/19/2018] [Indexed: 01/15/2023]
Abstract
Short-acting β2-adrenergic receptor agonists (SABAs) are the most commonly prescribed asthma medications worldwide. Response to SABAs is measured as bronchodilator drug response (BDR), which varies among racial/ethnic groups in the U.S1, 2. However, the genetic variation that contributes to BDR is largely undefined in African Americans with asthma3. To identify genetic variants that may contribute to differences in BDR in African Americans with asthma, we performed a genome-wide association study (GWAS) of BDR in 949 African American children with asthma, genotyped with the Axiom World Array 4 (Affymetrix, Santa Clara, CA) followed by imputation using 1000 Genomes phase III genotypes. We used linear regression models adjusting for age, sex, body mass index (BMI) and genetic ancestry to test for an association between BDR and genotype at single nucleotide polymorphisms (SNPs). To increase power and distinguish between shared vs. population-specific associations with BDR in children with asthma, we performed a meta-analysis across 949 African Americans and 1,830 Latinos (Total=2,779). Lastly, we performed genome-wide admixture mapping to identify regions whereby local African or European ancestry is associated with BDR in African Americans. We identified a population-specific association with an intergenic SNP on chromosome 9q21 that was significantly associated with BDR (rs73650726, p=7.69×10−9). A trans-ethnic meta-analysis across African Americans and Latinos identified three additional SNPs within the intron of PRKG1 that were significantly associated with BDR (rs7903366, rs7070958, and rs7081864, p≤5×10−8). Our results failed to replicate in three additional populations of 416 Latinos and 1,615 African Americans. Our findings indicate that both population specific and shared genetic variation contributes to differences in BDR in minority children with asthma, and that the genetic underpinnings of BDR may differ between racial/ethnic groups.
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Affiliation(s)
- Melissa L Spear
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Donglei Hu
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Maria Pino-Yanes
- Research Unit, Hospital Universitario N.S. de Candelaria, Universidad de La Laguna, Tenerife, Spain.,CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain.,Genomics and Health Group, Department of Biochemistry, Microbiology, Cell Biology and Genetics, Universidad de La Laguna, La Laguna, Tenerife, Spain
| | - Scott Huntsman
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Celeste Eng
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Albert M Levin
- Department of Public Health Sciences, Henry Ford Health System, Detroit, MI, USA
| | - Victor E Ortega
- Department of Internal Medicine, Wake Forest Baptist Medical Center, Winston Salem, NC, USA
| | - Marquitta J White
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Meghan E McGarry
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA, USA
| | - Neeta Thakur
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Joshua Galanter
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA.,Department of Medicine, University of California, San Francisco, San Francisco, CA, USA.,Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
| | - Angel C Y Mak
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Sam S Oh
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Elizabeth Ampleford
- Department of Internal Medicine, Wake Forest Baptist Medical Center, Winston Salem, NC, USA
| | - Stephen P Peters
- Department of Internal Medicine, Wake Forest Baptist Medical Center, Winston Salem, NC, USA
| | - Adam Davis
- UCSF Benioff Children's Hospital Oakland, Center for Community Health and Engagement, Oakland, CA, USA
| | - Rajesh Kumar
- Ann & Robert H. Lurie Children's Hospital of Chicago, Pediatrics, Chicago, IL, USA
| | - Harold J Farber
- Department of Pediatrics, Section of Pulmonology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Kelley Meade
- UCSF Benioff Children's Hospital Oakland, Oakland, CA, USA
| | - Pedro C Avila
- Division of Allergy-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Denise Serebrisky
- Pediatric Pulmonary Division, Jacobi Medical Center, Bronx, NY, USA.,Albert Einstein College of Medicine, Pediatrics, Bronx, NY, USA
| | | | | | | | - Shannon M Thyne
- Department of Pediatrics, David Geffen School of Medicine at ULCA, Olive View-UCLA Medical Center, Sylmar, CA, USA
| | | | | | - Rocio Chapela
- Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
| | - Andrés Moreno Estrada
- National Laboratory of Genomics for Biodiversity (LANGEBIO), CINVESTAV, Irapuato, Guanajuato, Mexico
| | - Karla Sandoval
- National Laboratory of Genomics for Biodiversity (LANGEBIO), CINVESTAV, Irapuato, Guanajuato, Mexico
| | - Max A Seibold
- Department of Pediatrics, National Jewish Health, Denver, CO, USA
| | - Cheryl A Winkler
- Basic Research Laboratory, National Cancer Institute, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD, USA
| | | | - Deborah A Myers
- Department of Medicine, The University of Arizona, Tucson, AZ, USA
| | - L Keoki Williams
- Center for Health Policy and Health Services Research,, Henry Ford Health System, Detroit, MI, USA.,Department of Internal Medicine, Henry Ford Health System, Detroit, MI, USA
| | - Ryan D Hernandez
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA.,California Institute for Quantitative Biosciences (QB3), University of California, San Francisco, CA, USA.,Institute for Human Genetics, University of California, San Francisco, CA, USA
| | - Dara G Torgerson
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Esteban G Burchard
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA. .,Department of Medicine, University of California, San Francisco, San Francisco, CA, USA.
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4
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Akashi S, Ahmed KA, Sawa T, Ono K, Tsutsuki H, Burgoyne JR, Ida T, Horio E, Prysyazhna O, Oike Y, Rahaman MM, Eaton P, Fujii S, Akaike T. Persistent Activation of cGMP-Dependent Protein Kinase by a Nitrated Cyclic Nucleotide via Site Specific Protein S-Guanylation. Biochemistry 2016; 55:751-61. [PMID: 26784639 DOI: 10.1021/acs.biochem.5b00774] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
8-Nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP) is a nitrated derivative of guanosine 3',5'-cyclic monophosphate (cGMP) formed endogenously under conditions associated with production of both reactive oxygen species and nitric oxide. It acts as an electrophilic second messenger in the regulation of cellular signaling by inducing a post-translational modification of redox-sensitive protein thiols via covalent adduction of cGMP moieties to protein thiols (protein S-guanylation). Here, we demonstrate that 8-nitro-cGMP potentially S-guanylates thiol groups of cGMP-dependent protein kinase (PKG), the enzyme that serves as one of the major receptor proteins for intracellular cGMP and controls a variety of cellular responses. S-Guanylation of PKG was found to occur in a site specific manner; Cys42 and Cys195 were the susceptible residues among 11 Cys residues. Importantly, S-guanylation at Cys195, which is located in the high-affinity cGMP binding domain of PKG, causes persistent enzyme activation as determined by in vitro kinase assay as well as by an organ bath assay. In vivo, S-guanylation of PKG was demonstrated to occur in mice without any specific treatment and was significantly enhanced by lipopolysaccharide administration. These findings warrant further investigation in terms of the physiological and pathophysiological roles of S-guanylation-dependent persistent PKG activation.
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Affiliation(s)
- Soichiro Akashi
- Department of Environmental Health Sciences and Molecular Toxicology, Tohoku University Graduate School of Medicine , 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Khandaker Ahtesham Ahmed
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University , 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Tomohiro Sawa
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University , 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency , Kawaguchi, Saitama 332-0012, Japan
| | - Katsuhiko Ono
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University , 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Hiroyasu Tsutsuki
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University , 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Joseph R Burgoyne
- Department of Cardiology, Cardiovascular Division, King's College London, The Rayne Institute, St Thomas' Hospital , London SE1 7EH, U.K
| | - Tomoaki Ida
- Department of Environmental Health Sciences and Molecular Toxicology, Tohoku University Graduate School of Medicine , 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Eiji Horio
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University , Honjo 1-1-1, Kumamoto 860-8556, Japan
| | - Oleksandra Prysyazhna
- Department of Cardiology, Cardiovascular Division, King's College London, The Rayne Institute, St Thomas' Hospital , London SE1 7EH, U.K
| | - Yuichi Oike
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University , Honjo 1-1-1, Kumamoto 860-8556, Japan
| | - Mizanur Md Rahaman
- Department of Environmental Health Sciences and Molecular Toxicology, Tohoku University Graduate School of Medicine , 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Philip Eaton
- Department of Cardiology, Cardiovascular Division, King's College London, The Rayne Institute, St Thomas' Hospital , London SE1 7EH, U.K
| | - Shigemoto Fujii
- Department of Environmental Health Sciences and Molecular Toxicology, Tohoku University Graduate School of Medicine , 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Takaaki Akaike
- Department of Environmental Health Sciences and Molecular Toxicology, Tohoku University Graduate School of Medicine , 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
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5
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Aguilar HN, Tracey CN, Zielnik B, Mitchell BF. Rho-kinase mediates diphosphorylation of myosin regulatory light chain in cultured uterine, but not vascular smooth muscle cells. J Cell Mol Med 2014; 16:2978-89. [PMID: 22947248 PMCID: PMC4393726 DOI: 10.1111/j.1582-4934.2012.01625.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 08/09/2012] [Indexed: 11/27/2022] Open
Abstract
Phosphorylation of myosin regulatory light chain (RLC) triggers contraction in smooth muscle myocytes. Dephosphorylation of phosphorylated RLC (pRLC) is mediated by myosin RLC phosphatase (MLCP), which is negatively regulated by rho-associated kinase (ROK). We have compared basal and stimulated concentrations of pRLC in myocytes from human coronary artery (hVM), which has a tonic contractile pattern to myocytes from human uterus (hUM), which has a phasic contractile pattern. Our studies reveal fundamental differences between hVM and hUM regarding the mechanisms regulating phosphorylation RLC. Whereas hVM responded to stimulation by phosphorylation of RLC at S19, hUM responded by forming diphosphorylated RLC (at T18 and S19; ppRLC), which, compared to pRLC, causes two to threefold greater activation of myosin ATPase that provides energy to power the contraction. Importantly, the conversion of pRLC to ppRLC is mediated by ROK. In hUM, MLCP has high activity for ppRLC and this is inhibited by ROK through phosphorylation of the substrate targeting subunit (MYPT1) at T853. Inhibitors of ROK significantly reduce contractility in both hVM and hUM. We demonstrated that inhibition of ppRLC in phasic myocytes (hUM) is 100-fold more sensitive to ROK inhibitors than is pRLC in tonic myocytes (hVM). We speculate that these differences in phosphorylation of RLC might reflect evolution of different contractile patterns to perform distinct physiological functions. Furthermore, our data suggest that low concentrations of ROK inhibitors might inhibit uterine contractions with minimal effects on vascular tone, thus posing a novel strategy for prevention or treatment of conditions such as preterm birth.
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Affiliation(s)
- Hector N Aguilar
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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6
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Wang GR, Surks HK, Tang KM, Zhu Y, Mendelsohn ME, Blanton RM. Steroid-sensitive gene 1 is a novel cyclic GMP-dependent protein kinase I substrate in vascular smooth muscle cells. J Biol Chem 2013; 288:24972-83. [PMID: 23831687 DOI: 10.1074/jbc.m113.456244] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
NO, via its second messenger cGMP, activates protein kinase GI (PKGI) to induce vascular smooth muscle cell relaxation. The mechanisms by which PKGI kinase activity regulates cardiovascular function remain incompletely understood. Therefore, to identify novel protein kinase G substrates in vascular cells, a λ phage coronary artery smooth muscle cell library was constructed and screened for phosphorylation by PKGI. The screen identified steroid-sensitive gene 1 (SSG1), which harbors several predicted PKGI phosphorylation sites. We observed direct and cGMP-regulated interaction between PKGI and SSG1. In cultured vascular smooth muscle cells, both the NO donor S-nitrosocysteine and atrial natriuretic peptide induced SSG1 phosphorylation, and mutation of SSG1 at each of the two predicted PKGI phosphorylation sites completely abolished its basal phosphorylation by PKGI. We detected high SSG1 expression in cardiovascular tissues. Finally, we found that activation of PKGI with cGMP regulated SSG1 intracellular distribution.
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Affiliation(s)
- Guang-rong Wang
- Molecular Cardiology Research Institute and Division of Cardiology, Tufts Medical Center, Boston, Massachusetts 02111, USA
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7
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Sellak H, Choi CS, Dey NB, Lincoln TM. Transcriptional and post-transcriptional regulation of cGMP-dependent protein kinase (PKG-I): pathophysiological significance. Cardiovasc Res 2013; 97:200-7. [PMID: 23139241 PMCID: PMC3543991 DOI: 10.1093/cvr/cvs327] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 09/26/2012] [Accepted: 10/26/2012] [Indexed: 12/29/2022] Open
Abstract
The ability of the endothelium to produce nitric oxide, which induces generation of cyclic guanosine monophosphate (cGMP) that activates cGMP-dependent protein kinase (PKG-I), in vascular smooth muscle cells (VSMCs), is essential for the maintenance of vascular homeostasis. Yet, disturbance of this nitric oxide/cGMP/PKG-I pathway has been shown to play an important role in many cardiovascular diseases. In the last two decades, in vitro and in vivo models of vascular injury have shown that PKG-I is suppressed following nitric oxide, cGMP, cytokine, and growth factor stimulation. The molecular basis for these changes in PKG-I expression is still poorly understood, and they are likely to be mediated by a number of processes, including changes in gene transcription, mRNA stability, protein synthesis, or protein degradation. Emerging studies have begun to define mechanisms responsible for changes in PKG-I expression and have identified cis- and trans-acting regulatory elements, with a plausible role being attributed to post-translational control of PKG-I protein levels. This review will focus mainly on recent advances in understanding of the regulation of PKG-I expression in VSMCs, with an emphasis on the physiological and pathological significance of PKG-I down-regulation in VSMCs in certain circumstances.
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Affiliation(s)
- Hassan Sellak
- Department of Physiology, College of Medicine, University of South Alabama, Medical Science Building Room 3103, Mobile, AL 36688, USA.
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8
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Mujoo K, Krumenacker JS, Murad F. Nitric oxide-cyclic GMP signaling in stem cell differentiation. Free Radic Biol Med 2011; 51:2150-7. [PMID: 22019632 PMCID: PMC3232180 DOI: 10.1016/j.freeradbiomed.2011.09.037] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 09/27/2011] [Accepted: 09/29/2011] [Indexed: 12/15/2022]
Abstract
The nitric oxide-cyclic GMP (NO-cGMP) pathway mediates important physiological functions associated with various integrative body systems including the cardiovascular and nervous systems. Furthermore, NO regulates cell growth, survival, apoptosis, proliferation, and differentiation at the cellular level. To understand the significance of the NO-cGMP pathway in development and differentiation, studies have been conducted both in developing embryos and in stem cells. Manipulation of the NO-cGMP pathway, by employing activators and inhibitors as pharmacological probes, and genetic manipulation of NO signaling components have implicated the involvement of this pathway in the regulation of stem cell differentiation. This review focuses on some of the work pertaining to the role of NO-cGMP in the differentiation of stem cells into cells of various lineages, particularly into myocardial cells, and in stem cell-based therapy.
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Affiliation(s)
- Kalpana Mujoo
- Brown Foundation Institute of Molecular Medicine, Texas Therapeutics Institute, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
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9
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Aggarwal S, Gross CM, Kumar S, Datar S, Oishi P, Kalkan G, Schreiber C, Fratz S, Fineman JR, Black SM. Attenuated vasodilatation in lambs with endogenous and exogenous activation of cGMP signaling: role of protein kinase G nitration. J Cell Physiol 2011; 226:3104-13. [PMID: 21351102 DOI: 10.1002/jcp.22692] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Pulmonary vasodilation is mediated through the activation of protein kinase G (PKG) via a signaling pathway involving nitric oxide (NO), natriuretic peptides (NP), and cyclic guanosine monophosphate (cGMP). In pulmonary hypertension secondary to congenital heart disease, this pathway is endogenously activated by an early vascular upregulation of NO and increased myocardial B-type NP expression and release. In the treatment of pulmonary hypertension, this pathway is exogenously activated using inhaled NO or other pharmacological agents. Despite this activation of cGMP, vascular dysfunction is present, suggesting that NO-cGMP independent mechanisms are involved and were the focus of this study. Exposure of pulmonary artery endothelial or smooth muscle cells to the NO donor, Spermine NONOate (SpNONOate), increased peroxynitrite (ONOO(-) ) generation and PKG-1α nitration, while PKG-1α activity was decreased. These changes were prevented by superoxide dismutase (SOD) or manganese(III)tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP) and mimicked by the ONOO(-) donor, 3-morpholinosydnonimine N-ethylcarbamide (SIN-1). Peripheral lung extracts from 4-week old lambs with increased pulmonary blood flow and pulmonary hypertension (Shunt lambs with endogenous activation of cGMP) or juvenile lambs treated with inhaled NO for 24 h (with exogenous activation of cGMP) revealed increased ONOO(-) levels, elevated PKG-1α nitration, and decreased kinase activity without changes in PKG-1α protein levels. However, in Shunt lambs treated with L-arginine or lambs administered polyethylene glycol conjugated-SOD (PEG-SOD) during inhaled NO exposure, ONOO(-) and PKG-1α nitration were diminished and kinase activity was preserved. Together our data reveal that vascular dysfunction can occur, despite elevated levels of cGMP, due to PKG-1α nitration and subsequent attenuation of activity.
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Affiliation(s)
- Saurabh Aggarwal
- Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta, Georgia 30912, USA
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10
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Aggarwal S, Rafikov R, Gross CM, Kumar S, Pardo D, Black SM. Purification and functional analysis of protein kinase G-1α using a bacterial expression system. Protein Expr Purif 2011; 79:271-6. [PMID: 21600289 DOI: 10.1016/j.pep.2011.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 05/03/2011] [Accepted: 05/04/2011] [Indexed: 10/18/2022]
Abstract
3',5' Cyclic guanosine monophosphate (cGMP)-dependent protein kinase G-1α (PKG-1α) is an enzyme that is a target of several anti-hypertensive and erectile dysfunction drugs. Binding of cGMP to PKG-1α produces a conformational change that leads to enzyme activation. Activated PKG-1α performs important roles both in blood vessel vasodilation and in maintaining the smooth muscle cell in a differentiated contractile state. Recombinant PKG-1α has been expressed and purified using Sf9-insect cells. However, attempts at purifying full length protein in a soluble and active form in prokaryotes have thus far been unsuccessful. These attempts have been hampered by the lack of proper eukaryotic protein folding machinery in bacteria. In this study, we report the successful expression and purification of PKG-1α using a genetically engineered Escherichia coli strain, Rosetta-gami 2(DE3), transduced with full-length human PKG-1α cDNA containing a C-terminal histidine tag. PKG-1α was purified to homogeneity using sequential nickel affinity chromatography, gel filtration and ion exchange MonoQ columns. Protein identity was confirmed by immunoblot analysis. N-terminal sequencing using Edman degradation demonstrated that the purified protein was full length. Analysis of enzyme kinetics, using a nonlinear regression curve, identified that, at constant cGMP levels (10μM) and varying ATP concentrations, PKG-1α had a maximal velocity (V(max)) of 5.02±0.25pmol/min/μg and a Michaelis-Menten constant (K(m)) of 11.78±2.68μM ATP. Recent studies have suggested that endothelial function can be attenuated by oxidative and/or nitrosative stress but the role of PKG-1α under these conditions is unclear. We found that PKG-1α enzyme activity was attenuated by exposure to the NO donor, spermine NONOate, hydrogen peroxide, and peroxynitrite but not by superoxide, suggesting that the attenuation of PKG-1α activity may be an under-appreciated mechanism underlying the development of endothelial dysfunction in a number of cardiovascular diseases.
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Affiliation(s)
- Saurabh Aggarwal
- Pulmonary Disease Program, Vascular Biology Center, Medical College of Georgia, Augusta, GA, United States
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Genes involved in vasoconstriction and vasodilation system affect salt-sensitive hypertension. PLoS One 2011; 6:e19620. [PMID: 21573014 PMCID: PMC3090407 DOI: 10.1371/journal.pone.0019620] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 04/12/2011] [Indexed: 01/11/2023] Open
Abstract
The importance of excess salt intake in the pathogenesis of hypertension is widely recognized. Blood pressure is controlled primarily by salt and water balance because of the infinite gain property of the kidney to rapidly eliminate excess fluid and salt. Up to fifty percent of patients with essential hypertension are salt-sensitive, as manifested by a rise in blood pressure with salt loading. We conducted a two-stage genetic analysis in hypertensive patients very accurately phenotyped for their salt-sensitivity. All newly discovered never treated before, essential hypertensives underwent an acute salt load to monitor the simultaneous changes in blood pressure and renal sodium excretion. The first stage consisted in an association analysis of genotyping data derived from genome-wide array on 329 subjects. Principal Component Analysis demonstrated that this population was homogenous. Among the strongest results, we detected a cluster of SNPs located in the first introns of PRKG1 gene (rs7897633, p = 2.34E-05) associated with variation in diastolic blood pressure after acute salt load. We further focused on two genetic loci, SLC24A3 and SLC8A1 (plasma membrane sodium/calcium exchange proteins, NCKX3 and NCX1, respectively) with a functional relationship with the previous gene and associated to variations in systolic blood pressure (the imputed rs3790261, p = 4.55E-06; and rs434082, p = 4.7E-03). In stage 2, we characterized 159 more patients for the SNPs in PRKG1, SLC24A3 and SLC8A1. Combined analysis showed an epistatic interaction of SNPs in SLC24A3 and SLC8A1 on the pressure-natriuresis (p interaction = 1.55E-04, p model = 3.35E-05), supporting their pathophysiological link in cellular calcium homeostasis. In conclusions, these findings point to a clear association between body sodium-blood pressure relations and molecules modulating the contractile state of vascular cells through an increase in cytoplasmic calcium concentration.
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12
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Sellak H, Lincoln TM, Choi CS. Stabilization of cGMP-dependent protein kinase G (PKG) expression in vascular smooth muscle cells: contribution of 3'UTR of its mRNA. J Biochem 2011; 149:433-41. [PMID: 21292805 DOI: 10.1093/jb/mvr003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The type-I cGMP-dependent protein kinase (PKG-I) expression regulation is not yet completely understood. In this study, we examined the role of 3'-untranslated region (3'UTR)-PKG-I messenger RNA (mRNA) in the control of PKG-I expression in vascular smooth muscle cells (VSMCs). Using a 3'-rapid amplification of cDNA ends (RACE) for the amplification of complementary DNA (cDNA) ends, we generated and cloned a 1.2-kb-3'UTR mRNA PKG-I in pGL3 control vector downstream of the luciferase reporter gene. Serial deletions and functional studies revealed that among the deleted constructs, only the 1.2-kb-3'UTR PKG-I mRNA possesses the highest activity in transfected VSMC. Kinetic luciferase assays in the presence of actinomycin D showed that this construct stabilizes luciferase activity compared to the control vector. Sequence analysis of 3'UTR-PKG-I mRNA revealed the existence of four AU-rich regions (AU1 through AU4) in addition to a potential poly(A) site. Different riboprobes were generated either by 5'-end-labelling of designed ribonucleotides, containing individual AU-rich regions or by in vitro transcription assay using cloned 1.2-kb cDNA as a template. RNA-electrophoretic mobility shift assay (EMSA) and ultra-violet cross-linking (UV-CL) assays showed that AU1, AU3, AU4 and 1.2-kb probes were able to retard cytosolic and nuclear proteins. Taken together, these data suggest that PKG-I expression is subjected to post-transcriptional regulation in VSMC through the 3'UTR of its mRNA.
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Affiliation(s)
- Hassan Sellak
- University of South Alabama, College of Medicine, Department of Physiology, Mobile, AL 36688, USA.
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13
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Chamorro-Jorganes A, Calleros L, Griera M, Saura M, Luengo A, Rodriguez-Puyol D, Rodriguez-Puyol M. Fibronectin upregulates cGMP-dependent protein kinase type Iβ through C/EBP transcription factor activation in contractile cells. Am J Physiol Cell Physiol 2010; 300:C683-91. [PMID: 21160032 DOI: 10.1152/ajpcell.00251.2010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The nitric oxide (NO)-soluble guanylate cyclase (sGC) pathway exerts most of its cellular actions through the activation of the cGMP-dependent protein kinase (PKG). Accumulation of extracellular matrix is one of the main structural changes in pathological conditions characterized by a decreased activity of this pathway, such as hypertension, diabetes, or aging, and it is a well-known fact that extracellular matrix proteins modulate cell phenotype through the interaction with membrane receptors such as integrins. The objectives of this study were 1) to evaluate whether extracellular matrix proteins, particularly fibronectin (FN), modulate PKG expression in contractile cells, 2) to analyze the mechanisms involved, and 3) to evaluate the functional consequences. FN increased type I PKG (PKG-I) protein content in human mesangial cells, an effect dependent on the interaction with β(1)-integrin. The FN upregulation of PKG-I protein content was due to increased mRNA expression, determined by augmented transcriptional activity of the PKG-I promoter region. Akt and the transcription factor CCAAT enhancer-binding protein (C/EBP) mediated the genesis of these changes. FN also increased PKG-I in another type of contractile cell, rat vascular smooth muscle cells (RVSMC). Tirofiban, a pharmacological analog of FN, increased PKG-I protein content in RVSMC and rat aortic walls and magnified the hypotensive effect of dibutyryl cGMP in conscious Wistar rats. The present results provide evidence of a mechanism able to increase PKG-I protein content in contractile cells. Elucidation of this novel mechanism provides a rationale for future pharmacotherapy in certain vascular diseases.
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Affiliation(s)
- Aranzazu Chamorro-Jorganes
- Dept. of Physiology, Facultad de Medicina, Universidad de Alcalá, Campus Universitario s/n, Alcalá de Henares, 28871 Madrid, Spain
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14
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Zhuang D, Balani P, Pu Q, Thakran S, Hassid A. Suppression of PKG by PDGF or nitric oxide in differentiated aortic smooth muscle cells: obligatory role of protein tyrosine phosphatase 1B. Am J Physiol Heart Circ Physiol 2010; 300:H57-63. [PMID: 21057040 DOI: 10.1152/ajpheart.00225.2010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Treatment of aortic smooth muscle cells with PDGF induces the upregulation of protein tyrosine phosphatase 1B (PTP1B). PTP1B, in turn, decreases the function of several growth factor receptors, thus completing a negative feedback loop. Studies have reported that PDGF induces the downregulation of PKG as part of a repertoire of dedifferentiation of vascular smooth muscle cells. Other studies have reported that chronic nitric oxide (NO) treatment also induces the downregulation of PKG. In the present study, we tested the hypothesis that the downregulation of PKG by PDGF or NO in differentiated rat aortic smooth muscle cells can be attributed to the upregulation of PTP1B. We found that treatment with PDGF or NO induced an upregulation of PTP1B levels. Overexpression of PTP1B induced a marked downregulation of PKG mRNA and protein levels, whereas the expression of dominant negative PTP1B or short interfering RNA directed against PTP1B blocked the capacity of PDGF or NO to decrease PKG levels. We conclude that the upregulation of PTP1B by PDGF or NO is both necessary and sufficient to induce the downregulation of PKG via an effect on PKG mRNA levels.
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Affiliation(s)
- Daming Zhuang
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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15
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Protein kinase G activity prevents pathological-level nitric oxide-induced apoptosis and promotes DNA synthesis/cell proliferation in vascular smooth muscle cells. Cardiovasc Pathol 2010; 19:e221-31. [DOI: 10.1016/j.carpath.2009.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2009] [Revised: 08/26/2009] [Accepted: 11/02/2009] [Indexed: 11/19/2022] Open
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16
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Inhibition of the mitochondrial permeability transition by protein kinase A in rat liver mitochondria and hepatocytes. Biochem J 2010; 431:411-21. [PMID: 20738255 DOI: 10.1042/bj20091741] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
NO and cGMP administered at reperfusion after ischaemia prevent injury to hepatocytes mediated by the MPT (mitochondrial permeability transition). To characterize further the mechanism of protection, the ability of hepatic cytosol in combination with cyclic nucleotides to delay onset of the calcium-induced MPT was evaluated in isolated rat liver mitochondria. Liver cytosol plus cGMP or cAMP dose-dependently inhibited the MPT, required ATP hydrolysis for inhibition and did not inhibit mitochondrial calcium uptake. Specific peptide inhibitors for PKA (protein kinase A), but not PKG (protein kinase G), abolished cytosol-induced inhibition of MPT onset. Activity assays showed a cGMP- and cAMP-stimulated protein kinase activity in liver cytosol that was completely inhibited by PKI, a PKA peptide inhibitor. Size-exclusion chromatography of liver cytosol produced a single peak of cGMP/cAMP-stimulated kinase activity with an estimated protein size of 180-220 kDa. This fraction was PKI-sensitive and delayed onset of the MPT. Incubation of active catalytic PKA subunit directly with mitochondria in the absence of cytosol and cyclic nucleotide also delayed MPT onset, and incubation with purified outer membranes led to phosphorylation of a major 31 kDa band. After ischaemia, administration at reperfusion of membrane-permeant cAMPs and cAMP-mobilizing glucagon prevented reperfusion injury to hepatocytes. In conclusion, PKA in liver cytosol activated by cGMP or cAMP acts directly on mitochondria to delay onset of the MPT and protect hepatocytes from cell death after ischaemia/reperfusion.
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17
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Choi C, Sellak H, Brown FM, Lincoln TM. cGMP-dependent protein kinase and the regulation of vascular smooth muscle cell gene expression: possible involvement of Elk-1 sumoylation. Am J Physiol Heart Circ Physiol 2010; 299:H1660-70. [PMID: 20802137 DOI: 10.1152/ajpheart.00677.2010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Although the regulation of smooth muscle cell (SMC) gene expression by cGMP-dependent protein kinase (PKG) is now recognized, the mechanisms underlying these effects are not fully understood. In this study, we report that PKG-I stimulates myocardin/serum response factor (SRF)-dependent gene expression in vascular SMCs. The expression of PKG in PKG-deficient cells enhanced myocardin-induced SM22 promoter activity in a concentration-dependent fashion. However, neither SRF nor myocardin expression was affected. To investigate alternative mechanisms, we examined whether PKG affects the phosphorylation of E26-like protein-1 (Elk-1), a SRF/myocardin transcription antagonist. The activation of PKG caused an increase in a higher molecular mass form of phospho-Elk-1 that was determined to be small ubiquitin-related modifier (sumo)ylated Elk-1. PKG increased Elk-1 sumoylation twofold compared with the PKG-deficient cells, and Elk-1 sumoylation was reduced using dominant-negative sumo-conjugating enzyme, DN-Ubc9, confirming PKG-dependent sumoylation of phospho-Elk-1 in vascular SMCs. In addition, PKG stimulated Elk-1 sumoylation in COS-7 cells overexpressing Elk-1, sumo-1, and PKG-I. The increased expression of PKG in vascular SMCs inhibited Elk-1 binding to SMC-specific promoters, SM22 and smooth muscle myosin heavy chain, as measured by EMSA and chromatin immunoprecipitation assay, and PKG suppressed the Elk-1 inhibition of SM22 reporter gene expression. Taken together, these data suggest that PKG-I decreases Elk-1 activity by sumo modification of Elk-1, thereby increasing myocardin-SRF activity on SMC-specific gene expression.
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Affiliation(s)
- ChungSik Choi
- Department of Physiology, College of Medicine, University of South Alabama, Mobile, Alabama 36609, USA
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18
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Khan LH, Rosenfeld CR, Liu XT, Magness RR. Regulation of the cGMP-cPKG pathway and large-conductance Ca2+-activated K+ channels in uterine arteries during the ovine ovarian cycle. Am J Physiol Endocrinol Metab 2010; 298:E222-8. [PMID: 19920217 PMCID: PMC2822482 DOI: 10.1152/ajpendo.00375.2009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The follicular phase of the ovine ovarian cycle demonstrates parallel increases in ovarian estrogens and uterine blood flow (UBF). Although estrogen and nitric oxide contribute to the rise in UBF, the signaling pathway remains unclear. We examined the relationship between the rise in UBF during the ovarian cycle of nonpregnant sheep and changes in the uterine vascular cGMP-dependent pathway and large-conductance Ca(2+)-activated K(+) channels (BK(Ca)). Nonpregnant ewes (n = 19) were synchronized to either follicular or luteal phase using a vaginal progesterone-releasing device (CIDR), followed by intramuscular PGF(2alpha), CIDR removal, and treatment with pregnant mare serum gonadotropin. UBF was measured with flow probes before tissue collection, and second-generation uterine artery segments were collected from nine follicular and seven luteal phase ewes. The pore-forming alpha- and regulatory beta-subunits that constitute the BK(Ca), soluble guanylyl cyclase (sGC), and cGMP-dependent protein kinase G (cPKG) isoforms (cPKG(1alpha) and cPKG(1beta)) were measured by Western analysis and cGMP levels by RIA. BK(Ca) subunits were localized by immunohistochemistry. UBF rose >3-fold (P < 0.04) in follicular phase ewes, paralleling a 2.3-fold rise in smooth muscle cGMP and 32% increase in cPKG(1alpha) (P < 0.05). sGC, cPKG(1beta), and the BK(Ca) alpha-subunit were unchanged. Notably, expression of beta(1)- and beta(2)-regulatory subunits rose 51 and 79% (P <or= 0.05), respectively. Increases in endogenous ovarian estrogens in follicular-phase ewes result in increases in UBF associated with upregulation of the cGMP- and cPKG-dependent pathway and increased vascular BK(Ca) beta/alpha-subunit stoichiometry, suggesting enhanced BK(Ca) activation contributes to the follicular phase rise in UBF.
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Affiliation(s)
- Liaqat H Khan
- Division of Neonatal-Perinatal Medicine, University of Texas Southwestern Medical School, Dallas, Texas, USA
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19
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Bachiller PR, Nakanishi H, Roberts JD. Transforming growth factor-beta modulates the expression of nitric oxide signaling enzymes in the injured developing lung and in vascular smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 2009; 298:L324-34. [PMID: 20023176 DOI: 10.1152/ajplung.00181.2009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Nitric oxide signaling has an important role in regulating pulmonary development and function. Expression of soluble guanylate cyclase (sGC) and cGMP-dependent protein kinase I (PKGI), both critical mediators of nitric oxide (NO) signaling, is diminished in the injured newborn lung through unknown mechanisms. Recent studies suggest that excessive transforming growth factor-beta (TGF-beta) activity inhibits injured newborn lung development. To explore mechanisms that regulate pulmonary NO signaling, we tested whether TGF-beta decreases sGC and PKGI expression in the injured developing lung and pulmonary vascular smooth muscle cells (SMC). We found that chronic oxygen-induced lung injury decreased pulmonary sGCalpha(1) and PKGI immunoreactivity in mouse pups and that exposure to a TGF-beta-neutralizing antibody prevented this reduction of sGC and PKGI protein expression. In addition, TGF-beta(1) decreased expression of NO signaling enzymes in freshly isolated pulmonary microvascular SMC/myofibroblasts, suggesting that TGF-beta has a direct role in modulating NO signaling in the pup lung. Moreover, TGF-beta(1) decreased sGC and PKGI expression in pulmonary artery and aortic SMC from adult rats and mice, suggesting a general role for TGF-beta in modulating NO signaling in vascular SMC. Although other cytokines decrease sGC mRNA stability, TGF-beta did not modulate sGCalpha(1) or PKGIbeta mRNA turnover in vascular SMC. These studies indicate for the first time that TGF-beta decreases NO signaling enzyme expression in the injured developing lung and pulmonary vascular SMC. Moreover, they suggest that TGF-beta-neutralizing molecules might counteract the effects of injury on NO signaling in the newborn lung.
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Affiliation(s)
- Patricia R Bachiller
- Cardiovascular Research Center, Massachusetts General Hospital-East, 149 13th St., Charlestown, MA 02129, USA
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20
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Cook ALM, Haynes JM. Phosphorylation of the PKG substrate, vasodilator-stimulated phosphoprotein (VASP), in human cultured prostatic stromal cells. Nitric Oxide 2007; 16:10-7. [PMID: 17049286 DOI: 10.1016/j.niox.2006.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Revised: 08/06/2006] [Accepted: 09/05/2006] [Indexed: 11/29/2022]
Abstract
Nitric oxide (NO) is known to regulate contractility and proliferation of cells within the prostate, however, the mechanism by which this occurs is unknown. The cGMP-dependent protein kinase (PKG) signalling pathway may be involved, and recent work has shown that activation of this pathway can be assessed by analysis of phosphorylation of vasodilator-stimulated phosphoprotein (VASP). The aim of the current study is to characterise the expression of VASP in the human prostate and human cultured prostatic stromal cells (HCPSCs), and to investigate whether NO activates PKG in these cells. Our studies revealed that VASP is expressed, and that incubation of HCPSCs with PKG-activating cGMP-analogues or the NO-donor, SNP, caused a significant PKG-dependent increase in VASP serine-239 phosphorylation. In addition, SNP elicited a reduction in intracellular K(+) in a time frame consistent with the phosphorylation of VASP and activation of PKG. These data demonstrate that VASP can be used to assess the NO/cGMP/PKG signalling pathway in HCPSCs. In addition, we demonstrate for the first time that SNP, probably via NO release, leads to phosphorylation of VASP in a manner consistent with PKG activation.
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Affiliation(s)
- Anna-Louise M Cook
- School of Biomedical Sciences, Curtin University of Technology, Bentley, WA, USA
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21
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Zeng Y, Zhuang S, Gloddek J, Tseng CC, Boss GR, Pilz RB. Regulation of cGMP-dependent protein kinase expression by Rho and Kruppel-like transcription factor-4. J Biol Chem 2006; 281:16951-16961. [PMID: 16632465 DOI: 10.1074/jbc.m602099200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Type I cGMP-dependent protein kinase (PKG I) plays a major role in vascular homeostasis by mediating smooth muscle relaxation in response to nitric oxide, but little is known about the regulation of PKG I expression in smooth muscle cells. We found opposing effects of RhoA and Rac1 on cellular PKG I expression: (i) cell density-dependent changes in PKG I expression varied directly with Rac1 activity and inversely with RhoA activity; (ii) RhoA activation by calpeptin suppressed PKG I, whereas RhoA down-regulation by small interfering RNA increased PKG I expression; and (iii) PKG I promoter activity was suppressed in cells expressing active RhoA or Rho-kinase but was enhanced in cells expressing active Rac1 or a dominant negative RhoA. Sp1 consensus sequences in the PKG I promoter were required for Rho regulation and bound nuclear proteins in a cell density-dependent manner, including the Krüppel-like factor 4 (KLF4). KLF4 was identified as a major trans-acting factor at two proximal Sp1 sites; active RhoA suppressed KLF4 DNA binding and trans-activation potential on the PKG I promoter. Experiments with actin-binding agents suggested that RhoA could regulate KLF4 via its ability to induce actin polymerization. Regulation of PKG I expression by RhoA may explain decreased PKG I levels in vascular smooth muscle cells found in some models of hypertension and vascular injury.
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Affiliation(s)
- Ying Zeng
- Department of Medicine and Cancer Center, University of California at San Diego, La Jolla, California 92093
| | - Shunhui Zhuang
- Department of Medicine and Cancer Center, University of California at San Diego, La Jolla, California 92093
| | - Jutta Gloddek
- Department of Medicine and Cancer Center, University of California at San Diego, La Jolla, California 92093
| | - Chi-Chuan Tseng
- Section of Gastroenterology, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Gerry R Boss
- Department of Medicine and Cancer Center, University of California at San Diego, La Jolla, California 92093
| | - Renate B Pilz
- Department of Medicine and Cancer Center, University of California at San Diego, La Jolla, California 92093.
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22
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Taniguchi M, Kwak YL, Jones KA, Warner DO, Perkins WJ. Nitric oxide sensitivity in pulmonary artery and airway smooth muscle: a possible role for cGMP responsiveness. Am J Physiol Lung Cell Mol Physiol 2005; 290:L1018-27. [PMID: 16326756 DOI: 10.1152/ajplung.00402.2005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
We aimed to assess intrinsic smooth muscle mechanisms contributing to greater nitric oxide (NO) responsiveness in pulmonary vascular vs. airway smooth muscle. Porcine pulmonary artery smooth muscle (PASM) and tracheal smooth muscle (TSM) strips were used in concentration-response studies to the NO donor (Z)-1-[N-2-aminoethyl-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NO). PASM consistently exhibited greater relaxation at a given DETA-NO concentration (NO responsiveness) than TSM NO responsiveness, with DETA-NO log EC(50) being -6.55 +/- 0.11 and -5.37 +/- 0.13 for PASM and TSM, respectively (P < 0.01). We determined relationships between tissue cGMP concentration ([cGMP](i)) and relaxation using the particulate guanylyl cyclase agonist atrial natriuretic peptide. Atrial natriuretic peptide resulted in nearly complete relaxation, with no detectable increase in [cGMP](i) in PASM and only 20% relaxation (10-fold increase in [cGMP](i)) in TSM, indicating that TSM is less cGMP responsive than PASM. Total cGMP-dependent protein kinase I (cGKI) mRNA expression was greater in PASM than in TSM (2.23 +/- 0.36 vs. 0.93 +/- 0.31 amol mRNA/mug total RNA, respectively; P < 0.01), but total cGKI protein expression was not significantly different (0.56 +/- 0.07 and 0.49 +/- 0.04 ng cGKI/mug protein, respectively). The phosphotransferase assay for the soluble fraction of tissue homogenates demonstrated no difference in the cGMP EC(50) between PASM and TSM. The maximal phosphotransferase activity indexed to the amount of total cGKI in the homogenate differed significantly between PASM and TSM (1.61 +/- 0.15 and 1.04 +/- pmol.min(-1).ng cGKI(-1), respectively; P < 0.05), suggesting that cGKI may be regulated differently in the two tissues. A novel intrinsic smooth muscle mechanism accounting for greater NO responsiveness in PASM vs. TSM is thus greater cGMP responsiveness from increased cGKI-specific activity in PASM.
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Affiliation(s)
- Miwa Taniguchi
- Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
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Sellak H, Choi C, Browner N, Lincoln TM. Upstream stimulatory factors (USF-1/USF-2) regulate human cGMP-dependent protein kinase I gene expression in vascular smooth muscle cells. J Biol Chem 2005; 280:18425-33. [PMID: 15741164 DOI: 10.1074/jbc.m500775200] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclic GMP-dependent protein kinase I plays a pivotal role in regulating smooth muscle cell relaxation, growth, and differentiation. Expression of the enzyme varies greatly in smooth muscle and in other tissues and cell types, yet little is known regarding the mechanisms regulating cGMP-dependent protein kinase gene expression. The present work was undertaken to characterize the mechanisms controlling kinase gene expression in vascular smooth muscle cells. A 2-kb human cGMP-dependent protein kinase I 5'-noncoding promoter sequence was characterized by serial deletion, and functional studies demonstrated that a 591-bp 5'-promoter construct possessed the highest activity compared with all other constructs generated from the larger promoter. Analysis of the sequence between -472 and -591 bp from the transcriptional start site revealed the existence of two E-like boxes known to bind upstream stimulatory factors. Electrophoretic mobility shift assays and functional studies using luciferase reporter gene assays identified upstream stimulatory factors as the transcription factors bound to the E-boxes in the 591-bp promoter. Site-directed mutagenesis of the E-boxes abolished the binding of upstream stimulatory factor proteins and decreased the activity of the cGMP-dependent protein kinase I 591-bp promoter, thus confirming the involvement of these transcription factors in mediating gene expression. Cotransfection experiments demonstrated that overexpression of upstream stimulatory factors 1 and 2 increased cGMP-dependent protein kinase I promoter activity. Collectively, these data suggest that the human proximal cGMP-dependent protein kinase I promoter is regulated by tandem E-boxes that bind upstream stimulatory factors.
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Affiliation(s)
- Hassan Sellak
- Department of Physiology, University of South Alabama, College of Medicine, Mobile, Alabama 36688, USA
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Yamamoto T, Suzuki N. Expression and function of cGMP-dependent protein kinase type I during medaka fish embryogenesis. J Biol Chem 2005; 280:16979-86. [PMID: 15710621 DOI: 10.1074/jbc.m412433200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We isolated and characterized cDNA clones (PKG Ialpha and PKG Ibeta) for medaka fish cGMP-dependent protein kinase (PKG) Ialpha and Ibeta, and demonstrated that both are expressed in the embryos after late gastrula stage. Whole-mount in situ hybridization using each isoform-specific probe revealed that the transcripts of the PKG Ialpha gene were present in the spinal cord and gill arch, whereas those of the PKG Ibeta gene were only weakly expressed in these organs, but highly expressed in the otic vesicles. Injection of PKG Ialpha-specific morpholino antisense oligonucleotides (Ialpha-MO) into two-cell stage medaka fish embryos caused severe abnormalities in the developing embryos, such as the development of a hammer-like head, fusion of the developing eyes, and degeneration of cells around the eyes, whereas injection of PKG Ibeta-specific morpholino antisense oligonucleotides (Ibeta-MO) caused fewer abnormalities in the embryos, even when injected at higher concentrations than Ialpha-MO. The PKG I-overexpressing embryos exhibited smaller eyes and enlargement of the forebrain, a phenotype similar to that observed in the cAMP-dependent protein kinase (PKA)-depressed embryos. In the PKG-deficient embryos, a sonic hedgehog (shh)-target gene, HNF-3beta, was expressed weakly, and this phenotype was similar to that observed in the PKA-overexpressing embryos suggesting that the cGMP/PKG signaling pathway is involved in some steps of shh signaling. We also demonstrated that Gli proteins, shh-downstream molecules, are phosphorylated by the NO/cGMP signaling pathway, probably by PKG in NG108-15 neuroblastoma cells. These results imply that PKG and PKA share common substrates and work in an opposite manner during the early embryogenesis of medaka fish.
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Affiliation(s)
- Takehiro Yamamoto
- Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
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Kulhanek-Heinze S, Gerbes AL, Gerwig T, Vollmar AM, Kiemer AK. Protein kinase A dependent signalling mediates anti-apoptotic effects of the atrial natriuretic peptide in ischemic livers. J Hepatol 2004; 41:414-20. [PMID: 15336444 DOI: 10.1016/j.jhep.2004.05.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2003] [Revised: 05/17/2004] [Accepted: 05/27/2004] [Indexed: 12/30/2022]
Abstract
BACKGROUND/AIMS Preconditioning of livers with atrial natriuretic peptide (ANP) attenuates ischemia-reperfusion injury (IRI) via the particulate guanylate cyclase. Recently, we have shown that ANP affects the p38 MAPK signalling cascade in the liver. Thus, aim of the present study was to elucidate the role of cGMP- and p38 MAPK-dependent signalling pathways in ANP-mediated anti-apoptotic effects. METHODS Rat livers were perfused with KH-buffer with or without ANP, 8-Br-cGMP (+/-kinase inhibitors) and kept in UW solution (4 degrees C, 24h). Caspase-3-like activity was measured by a fluorometric assay. Expression of cGMP-dependent protein kinases (PKG) in liver tissue was determined by RT-PCR, BAD phosphorylation by Western blot, and cAMP-dependent protein kinase (protein kinase A, PKA) activity by in vitro phosphorylation. RESULTS Compared to control organs, ANP-preconditioning reduced post-ischemic caspase-3-like activity. Neither perfusion with a p38 MAPK inhibitor nor with a PKG inhibitor abolished the ANP-mediated anti-apoptotic action. The two PKG isoforms were demonstrated not to be expressed in the liver. In contrast, liver perfusion with a selective PKA inhibitor abrogated the anti-apoptotic effect of ANP. Phosphorylation of pro-apoptotic BAD by ANP-activated PKA might inhibit liver cell apoptosis. CONCLUSIONS ANP mediates its anti-apoptotic action during ischemic injury via a crosstalk with the PKA pathway.
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Affiliation(s)
- Stefanie Kulhanek-Heinze
- Department of Pharmacy, Center of Drug Research, University of Munich, Butenandtstr. 5-13, 81377 Munich, Germany
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26
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Abstract
The natriuretic peptides, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP), are a family of polypeptide mediators exerting numerous actions in cardiovascular homeostasis. ANP and BNP are cardiac derived, being secreted and up-regulated in myocardium in response to many pathophysiological stimuli. CNP is an endothelium-derived mediator. The classical endocrine effects of ANP and BNP on fluid homeostasis and blood pressure, especially in conditions characterised by left ventricular dysfunction, are well recognised and extensively researched. However, there is accumulating evidence that, in addition to endocrine actions, ANP and BNP exhibit important autocrine and paracrine functions within the heart and coronary circulation. These include regulation of myocyte growth, inhibition of fibroblast proliferation and extracellular matrix deposition, a cytoprotective anti-ischaemic (preconditioning-like) function, and influences on coronary endothelium and vascular smooth muscle proliferation and contractility. Most if not all of these actions can be ascribed to particulate guanylyl cyclase activation because the ANP/BNP receptor, natriuretic peptide receptor (NPR)-A, has an intracellular guanylyl cyclase domain. Subsequent elevation of the intracellular second messenger cGMP may exert diverse physiological effects through activation of cGMP-dependent protein kinases (cGK), predominantly cGK-I. However, there appear to be other contributory mechanisms in several of these actions, including the augmentation of nitric oxide synthesis. These diverse actions may represent counterregulatory mechanisms in the pathophysiology of many cardiovascular diseases, not just those typified by left ventricular dysfunction. Ultimately, insights from the autocrine/paracrine actions of natriuretic peptides may provide routes to therapeutic application in cardiac diseases of natriuretic peptides and drugs that modify their availability.
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27
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Chang S, Hypolite JA, Velez M, Changolkar A, Wein AJ, Chacko S, DiSanto ME. Downregulation of cGMP-dependent protein kinase-1 activity in the corpus cavernosum smooth muscle of diabetic rabbits. Am J Physiol Regul Integr Comp Physiol 2004; 287:R950-60. [PMID: 15205187 DOI: 10.1152/ajpregu.00639.2003] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Increased guanosine 3',5'-cyclic monophosphate (cGMP), induced by nitric oxide release, is crucial for corpus cavernosum smooth muscle (CCSM) relaxation within the penis. This CCSM relaxation (necessary for penile erection) is impaired in men with erectile dysfunction (ED), especially those men with diabetes. One of the effector proteins for cGMP is cGMP-dependent protein kinase-1 (PKG-1). PKG-1 knockout mice exhibit detrusor overactivity (Am J Physiol Regul Integr Comp Physiol 279: R1112-R1120, 2000) and, more relevant to this study, ED (Proc Natl Acad Sci USA 97: 2349-2354, 2000), suggesting an in vivo role for PKG-1 in urogenital smooth muscle relaxation. In the current study, using normal rabbit CCSM, Western blot analysis revealed high expression of PKG-1 at levels almost equivalent to aorta (previously shown to have high PKG-1 expression) and that the two known alternatively spliced isoforms of PKG-1 (alpha and beta) are expressed in nearly equal amounts in the CCSM. However, in response to alloxan-induced diabetes, there was a decrease in expression of both PKG-1 isoforms at the mRNA and protein levels as determined by real-time RT-PCR and Western blotting, respectively, but with the PKG-1alpha isoform expression decreased to a greater extent. Moreover, diabetes was associated with significantly decreased PKG-1 activity of CCSM in vitro, correlating with decreased CCSM relaxation. Immunofluorescence microscopy revealed a diabetes-associated decrease in PKG-1 in the CCSM cells. In conclusion, our results demonstrate for the first time a significant downregulation of PKG-1 expression associated with decreased PKG-1 activity in the CCSM in response to diabetes. Furthermore, these results suggest a mechanistic basis for the decreased efficacy of phosphodiesterase V inhibitors in treating diabetic patients with ED.
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Affiliation(s)
- Shaohua Chang
- Room 744, Forchheimer Bldg., Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10411, USA
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28
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Buxton ILO. Regulation of uterine function: a biochemical conundrum in the regulation of smooth muscle relaxation. Mol Pharmacol 2004; 65:1051-9. [PMID: 15102932 DOI: 10.1124/mol.65.5.1051] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Premature birth accounts for the majority of fetal morbidity and mortality in the developed world and is disproportionately represented in some populations, such as African Americans in the United States. The costs associated with prematurity are staggering in both monetary and human terms. Present therapeutic approaches for the treatment of labor leading to preterm delivery are inadequate and our understanding of the regulation of myometrial smooth muscle contraction-relaxation is incomplete. The ability of nitric oxide to relax smooth muscle has led to an interest in employing nitric oxide-donors in the treatment of preterm labor. Fundamental differences exist, however, in the regulation of uterine smooth muscle relaxation and that of other smooth muscles and constitute a conundrum in our understanding. We review the evidence that nitric oxide-mediated relaxation of myometrial smooth muscle, unlike vascular or gastrointestinal smooth muscle, is independent of global elevation of cyclic guanosine 5'-monophosphate. Applying our current understanding of microdomain signaling and taking clues from genomic studies of pregnancy, we offer a framework in which to view the apparent conundrum and suggest testable hypotheses of uterine relaxation signaling that can explain the mechanistic distinctions. We propose that understanding these mechanistic distinctions in myometrium will reveal molecular targets that are unique and thus may be explored as therapeutic targets in the development of new uterine smooth muscle-specific tocolytics.
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Affiliation(s)
- Iain L O Buxton
- Department of Pharmacology, University of Nevada School of Medicine, Reno, NV 89557, USA.
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29
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Krumenacker JS, Hanafy KA, Murad F. Regulation of nitric oxide and soluble guanylyl cyclase. Brain Res Bull 2004; 62:505-15. [PMID: 15036565 DOI: 10.1016/s0361-9230(03)00102-3] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2002] [Accepted: 02/17/2003] [Indexed: 02/08/2023]
Abstract
Since the discoveries that have verified nitric oxide (NO) as an endogenously produced cell signaling molecule, research surrounding its production and mechanisms of action have been studied at an exponentially increasing rate. NO is produced by a family of enzymes termed the NO synthases (NOS), which are regulated independently by various stimuli. Once produced, NO can solicit numerous biological events by reacting with various metals, thiols, and oxygen species to modify proteins, DNA and lipids. One of the most biologically relevant actions of NO is its binding to the heme moiety in the heterodimeric enzyme, soluble guanylyl cyclase (sGC). Activation of sGC by NO results in the production of the second messenger molecule, 3',5'-cyclic guanosine monophosphate (cGMP), which can regulate numerous physiological events such as vasodilatation and neurotransmission. Here we will review the synthesis and fate of NO, and discuss the activation and regulation of the NO receptor, sGC.
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Affiliation(s)
- Joshua S Krumenacker
- Department of Integrative Biology and Pharmacology, Institute of Molecular Medicine, University of Texas Houston Medical School, 6431 Fannin Street, Houston, TX 77030, USA
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30
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Browner NC, Sellak H, Lincoln TM. Downregulation of cGMP-dependent protein kinase expression by inflammatory cytokines in vascular smooth muscle cells. Am J Physiol Cell Physiol 2004; 287:C88-96. [PMID: 14985234 DOI: 10.1152/ajpcell.00039.2004] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
NO and cGMP have antigrowth and anti-inflammatory effects on the vessel wall in response to injury. It is well established that after vascular injury proinflammatory cytokines are involved in vascular wall remodeling. The purpose of this study was to ascertain the signaling mechanisms involved in cGMP-dependent protein kinase (PKG) suppression by inflammatory cytokines in primary bovine aortic vascular smooth muscle cells (VSMC). Interleukin (IL)-Ibeta, tumor necrosis factor (TNF)-alpha, and LPS decreased the mRNA and protein levels of PKG in VSMC. IL-Ibeta, TNF-alpha, and LPS increased inducible nitric oxide synthase (iNOS) expression and cGMP production. Treatment of cells with selective inhibitors of iNOS or soluble guanylate cyclase (sGC) reversed the downregulation of PKG expression induced by cytokines and LPS. The NO donor (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA NONOate) and 3-(5-hydroxymethyl-2-furyl)-1-benzylindazole (YC-1), a NO-independent sGC activator, decreased PKG mRNA and protein expression in bovine aortic VSMC. Cyclic nucleotide analogs [8-(4-chlorophenylthio)guanosine 3',5'-cyclic monophosphate (CPT-cGMP) and 8-(4-chlorophenylthio)adenosine 3,5'-cyclic monophosphate (CPT-cAMP)] also suppressed PKG mRNA and protein expression. However, CPT-cAMP was more effective than CPT-cGMP in decreasing PKG mRNA levels. Selective inhibition of PKA with the Rp isomer of 8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphorothioate (Rp-8p-CPT cAMPS) prevented the downregulation of PKG by LPS. In contrast, the Rp isomer of 8-(4-chlorophenylthio)guanosine 3,5'-cyclic monophosphorothioate (Rp-8p-CPT cGMPS; inhibitor of PKG) had no effect on LPS-induced inhibition of PKG mRNA and protein expression. These studies suggest that cross-activation of PKA in response to iNOS expression by inflammatory mediators downregulates PKG expression in bovine aortic VSMC.
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MESH Headings
- Animals
- Aorta
- Cattle
- Cells, Cultured
- Cyclic GMP-Dependent Protein Kinases/metabolism
- Down-Regulation
- Enzyme Activators/pharmacology
- Enzyme Inhibitors/pharmacology
- Humans
- Indazoles/pharmacology
- Interleukin-1/metabolism
- Interleukin-1/pharmacology
- Lipopolysaccharides/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Nitric Oxide Donors/pharmacology
- Nitroso Compounds/pharmacology
- Nucleotides, Cyclic/pharmacology
- Oxadiazoles/pharmacology
- Quinoxalines/pharmacology
- Recombinant Proteins/pharmacology
- Tumor Necrosis Factor-alpha/metabolism
- Tumor Necrosis Factor-alpha/pharmacology
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Affiliation(s)
- Natasha C Browner
- Department of Physiology, University of South Alabama, Mobile, AL 36688, USA
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31
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Richie-Jannetta R, Francis SH, Corbin JD. Dimerization of cGMP-dependent protein kinase Ibeta is mediated by an extensive amino-terminal leucine zipper motif, and dimerization modulates enzyme function. J Biol Chem 2003; 278:50070-9. [PMID: 12933804 DOI: 10.1074/jbc.m306796200] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
All mammalian cGMP-dependent protein kinases (PKGs) are dimeric. Dimerization of PKGs involves sequences located near the amino termini, which contain a conserved, extended leucine zipper motif. In PKG Ibeta this includes eight Leu/Ile heptad repeats, and in the present study, deletion and site-directed mutagenesis have been used to systematically delete these repeats or substitute individual Leu/Ile. The enzymatic properties and quaternary structures of these purified PKG mutants have been determined. All had specific enzyme activities comparable to wild type PKG. Simultaneous substitution of alanine at four or more of the Leu/Ile heptad repeats ((L3A/L10A/L17A/I24A), (L31A/I38A/L45A/I52A), (L17A/I24A/L31A/I38A/L45A/I52A), and (L3A/L10A/L45A/I52A)) of the motif produces a monomeric PKG Ibeta. Mutation of two Leu/Ile heptad repeats can produce either a dimeric (L3A/L10A) or monomeric (L17A/I24A and L31A/I38A) PKG. Point mutation of Leu-17 or Ile-24 (L17A or I24A) does not disrupt dimerization. These results suggest that all eight Leu/Ile heptad repeats are involved in dimerization of PKG Ibeta. Six of the eight repeats are sufficient to mediate dimerization, but substitutions at some positions (Leu-17, Ile-24, Leu-31, and Ile-38) appear to have greater impact than others on dimerization. The Ka of cGMP for activation of monomeric mutants (PKG Ibeta (delta1-52) and PKG Ibeta L17A/I24A/L31A/I38A/L45A/I52A) is 2- to 3-fold greater than that for wild type dimeric PKG Ibeta, and there is a corresponding 2- to 3-fold increase in cGMP-dissociation rate of the high affinity cGMP-binding site (site A) of these monomers. These results indicate that dimerization increases sensitivity for cGMP activation of the enzyme.
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Affiliation(s)
- Robyn Richie-Jannetta
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0615, USA
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32
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Wollert KC, Yurukova S, Kilic A, Begrow F, Fiedler B, Gambaryan S, Walter U, Lohmann SM, Kuhn M. Increased effects of C-type natriuretic peptide on contractility and calcium regulation in murine hearts overexpressing cyclic GMP-dependent protein kinase I. Br J Pharmacol 2003; 140:1227-36. [PMID: 14609817 PMCID: PMC1574150 DOI: 10.1038/sj.bjp.0705567] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. C-type natriuretic peptide (CNP) and its receptor guanylyl cyclase (GC-B) are expressed in the heart and modulate cardiac contractility in a cGMP-dependent manner. Since the distal cellular signalling pathways remain unclear, we evaluated the peptide effects on cardiac function and calcium regulation in wild-type (WT) and transgenic mice with cardiac overexpression of cGMP-dependent protein kinase I (PKG ITG). 2. In isolated, perfused working WT hearts, CNP (10 nm) provoked an immediate increase in the maximal rates of contraction and relaxation, a small increase in the left ventricular systolic pressure and a decrease in the time of relaxation. These changes in cardiac function were accompanied by a marked increase in the levels of Ser16-phosphorylated phospholamban (PLB). 3. In PKG ITG hearts, the effects of CNP on cardiac contractility and relaxation as well as on PLB phosphorylation were markedly enhanced. 4. CNP increased cell shortening and systolic Cai2+ levels, and accelerated Cai2+ decay in isolated, Indo-1/AM-loaded WT cardiomyocytes, and these effects were enhanced in PKG I-overexpressing cardiomyocytes. 5. 8-pCPT-cGMP, a membrane-permeable PKG activator, mimicked the contractile and molecular actions of CNP, the effects again being more pronounced in PKG ITG hearts. In contrast, the cardiac responses to beta-adrenergic stimulation were not different between genotypes. 6. Taken together, our data indicate that PKG I is a downstream target activated by the CNP/GC-B/cGMP-signalling pathway in cardiac myocytes. cGMP/PKG I-stimulated phosphorylation of PLB and subsequent activation of the sarcoplasmic reticulum Ca2+ pump appear to mediate the positive inotropic and lusitropic responses to CNP.
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Affiliation(s)
- Kai C Wollert
- Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany
| | - Sevdalina Yurukova
- Institute of Pharmacology and Toxicology, Universitäts Klinikum Münster, Domagkstrasse 12, Münster D-48129, Germany
| | - Ana Kilic
- Institute of Pharmacology and Toxicology, Universitäts Klinikum Münster, Domagkstrasse 12, Münster D-48129, Germany
| | - Frank Begrow
- Institute of Pharmacology and Toxicology, Universitäts Klinikum Münster, Domagkstrasse 12, Münster D-48129, Germany
| | - Beate Fiedler
- Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany
| | - Stepan Gambaryan
- Institute of Clinical Biochemistry and Pathobiochemistry, University of Würzburg, Würzburg, Germany
| | - Ulrich Walter
- Institute of Clinical Biochemistry and Pathobiochemistry, University of Würzburg, Würzburg, Germany
| | - Suzanne M Lohmann
- Institute of Clinical Biochemistry and Pathobiochemistry, University of Würzburg, Würzburg, Germany
| | - Michaela Kuhn
- Institute of Pharmacology and Toxicology, Universitäts Klinikum Münster, Domagkstrasse 12, Münster D-48129, Germany
- Author for correspondence:
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33
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Wang S, Wu X, Lincoln TM, Murphy-Ullrich JE. Expression of constitutively active cGMP-dependent protein kinase prevents glucose stimulation of thrombospondin 1 expression and TGF-beta activity. Diabetes 2003; 52:2144-50. [PMID: 12882934 DOI: 10.2337/diabetes.52.8.2144] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Hyperglycemia is a crucial factor in the development of diabetic nephropathy. We previously showed that high glucose upregulates thrombospondin 1 (TSP1)-dependent transforming growth factor (TGF)-beta activation by altering cGMP-dependent protein kinase (PKG) activity as a result of decreased nitric oxide signaling. In the present study, we showed that high glucose concentrations significantly reduced endogenous PKG activity. To further examine the mechanisms by which PKG regulates TSP1 expression and TSP1-dependent TGF-beta activation, we generated stably transfected rat mesangial cells (RMCs) with inducible expression tetracycline-induced gene expression of the catalytic domain of PKG. After tetracycline induction, the catalytic domain of PKG is expressed as a cGMP-independent active kinase. Expression of the catalytic domain prevented high glucose-mediated increases in transcription of the TSP1 gene with no alteration in TSP1 mRNA stability. Glucose stimulation of TSP1 protein expression and TGF-beta bioactivity were also downregulated. TGF-beta-dependent fibronectin and type IV collagen expression under high glucose conditions were significantly reduced upon catalytic domain expression in transfected RMCs. These results show that constitutively active PKG inhibits the fibrogenic potential of high glucose through repression of TSP1-dependent TGF-beta bioactivity, suggesting that gene transfer of the catalytic domain of PKG might provide a new strategy for treatment of diabetic renal fibrosis.
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Affiliation(s)
- Shuxia Wang
- Department of Pathology, Division of Molecular and Cellular Pathology, Cell Adhesion and Matrix Research Center, University of Alabama at Birmingham, Birmingham, Alabama, USA
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34
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Yamahara K, Itoh H, Chun TH, Ogawa Y, Yamashita J, Sawada N, Fukunaga Y, Sone M, Yurugi-Kobayashi T, Miyashita K, Tsujimoto H, Kook H, Feil R, Garbers DL, Hofmann F, Nakao K. Significance and therapeutic potential of the natriuretic peptides/cGMP/cGMP-dependent protein kinase pathway in vascular regeneration. Proc Natl Acad Sci U S A 2003; 100:3404-9. [PMID: 12621153 PMCID: PMC152305 DOI: 10.1073/pnas.0538059100] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Natriuretic peptides (NPs), which consist of atrial, brain, and C-type natriuretic peptides (ANP, BNP, and CNP, respectively), are characterized as cardiac or vascular hormones that elicit their biological effects by activation of the cGMPcGMP-dependent protein kinase (cGK) pathway. We recently reported that adenoviral gene transfer of CNP into rabbit blood vessels not only suppressed neointimal formation but also accelerated reendothelialization, a required step for endothelium-dependent vasorelaxation and antithrombogenicity. Accordingly, we investigated the therapeutic potential of the NPscGMPcGK pathway for vascular regeneration. In transgenic (Tg) mice that overexpress BNP in response to hindlimb ischemia, neovascularization with appropriate mural cell coating was accelerated without edema or bleeding, and impaired angiogenesis by the suppression of nitric oxide production was effectively rescued. Furthermore, in BNP-Tg mice, inflammatory cell infiltration in ischemic tissue and vascular superoxide production were suppressed compared with control mice. Ischemia-induced angiogenesis was also significantly potentiated in cGK type I Tg mice, but attenuated in cGK type I knockout mice. NPs significantly stimulated capillary network formation of cultured endothelial cells by cGK stimulation and subsequent Erk12 activation. Furthermore, gene transfer of CNP into ischemic muscles effectively accelerated angiogenesis. These findings reveal an action of the NPscGMPcGK pathway to exert multiple vasculoprotective and regenerative actions in the absence of apparent adverse effects, and therefore suggest that NPs as the endogenous cardiovascular hormone can be used as a strategy of therapeutic angiogenesis in patients with tissue ischemia.
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MESH Headings
- Animals
- Atrial Natriuretic Factor/genetics
- Atrial Natriuretic Factor/physiology
- Atrial Natriuretic Factor/therapeutic use
- Blood Vessels/drug effects
- Blood Vessels/physiology
- Cells, Cultured
- Cyclic GMP/physiology
- Cyclic GMP-Dependent Protein Kinases/physiology
- Gene Expression
- Gene Transfer Techniques
- Humans
- Inflammation/etiology
- Inflammation/pathology
- Ischemia/therapy
- Mice
- Mice, Knockout
- Mice, Transgenic
- Natriuretic Peptide, Brain/genetics
- Natriuretic Peptide, Brain/physiology
- Natriuretic Peptide, Brain/therapeutic use
- Natriuretic Peptide, C-Type/genetics
- Natriuretic Peptide, C-Type/physiology
- Natriuretic Peptide, C-Type/therapeutic use
- Neovascularization, Physiologic
- Regeneration/drug effects
- Regeneration/physiology
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Affiliation(s)
- Kenichi Yamahara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
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35
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West GA, Meno JR, Nguyen TSK, Ngai AC, Simard JM, Winn HR. cGMP-dependent and not cAMP-dependent kinase is required for adenosine-induced dilation of intracerebral arterioles. J Cardiovasc Pharmacol 2003; 41:444-51. [PMID: 12605023 DOI: 10.1097/00005344-200303000-00013] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Adenosine (ADO) is a potent cerebral vasodilator and has been proposed as a metabolic regulator of cerebral blood flow. However, the signal transduction pathway by which ADO causes vasodilation in cerebral microvessels is currently unknown. The current study was designed to investigate the role of cyclic nucleotides and cyclic nucleotide-dependent protein kinases in ADO-induced dilation of resistance-sized rat cerebral arterioles that develop spontaneous tone. Arterioles were cannulated and perfused intraluminally at constant flow (2 microl/min) and pressure (60 mm Hg). ADO (29.7 +/- 2.0%; 1 microM), CGS-21680 (16 +/- 4%, 1 microM), 8-bromo-cyclic guanosine monophosphate (8 Br-cGMP; 29.9 +/- 3.9%; 100 microM), sodium nitroprusside (SNP; 30.6 +/- 3.3%, 1 microM), cyclic guanine monophosphate-dependent protein kinase activator (Sp-8-pCPT-cGMPS, 25.9 +/- 4.2%; 10 microM), forskolin (30.5 +/- 5.9%; 0.1 microM), and pH 6.8 all produced large dilations. The selective cGMP-dependent protein kinase inhibitor, Rp-8-pCPT-cGMPS (10 microM), had no effect on resting diameter or reactivity to acidic pH, but significantly ( < 0.05) attenuated arteriolar dilations to ADO (59%, n = 8), CGS-21680 (60%, n = 4), SNP (62%, n = 3), 8 Br-cGMP (88%, n = 3), and Sp-8-pCPT-cGMPS (98%, n = 3). H8, the less-selective cyclic nucleotide-dependent protein kinase inhibitor, had similar effects as Rp-8-pCPT-cGMPS. Additionally, the inhibitor of the soluble guanylate cyclase, 1H-[1,24]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ), blocked the response to SNP (70% inhibition) and significantly inhibited the ADO response (43% inhibition). In contrast, inhibition of the cyclic ADO monophosphate (cAMP)-dependent protein kinase Rp-8-CPT-cAMPS had no effect on the ADO, SNP, or pH responses, but significantly blocked forskolin-induced vasodilation (53%). It is concluded that ADO-induced vasodilation in cerebral microvessels, at least in part, involves cGMP and cGMP-dependent protein kinase, but not cAMP or cAMP-dependent kinase. Our data therefore provides a new insight into mechanisms by which ADO invokes vasodilation in cerebral microvascular arterioles.
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Affiliation(s)
- G Alexander West
- Department of Neurological Surgery, University of Washington, Seattle, Washington 98104, USA.
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36
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Harumi T, Watanabe T, Yamamoto T, Tanabe Y, Suzuki N. Expression of membrane-bound and soluble guanylyl cyclase mRNAs in embryonic and adult retina of the medaka fish Oryzias latipes. Zoolog Sci 2003; 20:133-40. [PMID: 12655176 DOI: 10.2108/zsj.20.133] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Localization of mRNAs for four membrane-bound guanylyl cyclases (membrane GCs; OlGC3, OlGC4, OlGC5, and OlGC-R2), three soluble guanylyl cyclase subunits (soluble GC; OlGCS-alpha(1), OlGCS-alpha(2), and OlGCS-beta(1)), neuronal nitric oxide synthase (nNOS), and cGMP-dependent protein kinase I (cGK I) was examined in the embryonic and adult retinas of the medaka fish Oryzias latipes by in situ hybridization. All of the membrane GC mRNAs were detected in the photoreceptor cells of the adult and embryonic retinas, but in different parts; the OlGC3 and OlGC5 mRNAs were expressed in the proximal part and the OlGC4 and OlGC-R2 mRNAs were expressed in the outer nuclear layer. The mRNA for nNOS was expressed in a scattered fashion on the inner side of the inner nuclear layer in the adult and embryonic retinas. The mRNAs (OlGCS-alpha(2) and OlGCS- beta(1)) of two soluble GC subunits (alpha(2) and beta(1)) were expressed mainly in the inner nuclear layer and the ganglion cell layer of the embryonic retina while the mRNAs of the soluble GC alpha(1) subunit and cGK I were not detected in either the adult or embryonic retina. These results suggest that NO itself and/or the cGMP generated by soluble GC (alpha(2)/beta(1) heterodimer) play a novel role in the neuronal signaling and neuronal development in the medaka fish embryonic retina in addition to the role played by phototransduction through membrane GCs in the adult and embryonic retinas.
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Affiliation(s)
- Tatsuo Harumi
- Department of Anatomy, Asahikawa Medical College, Hokkaido, Japan.
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Murthy KS, Zhou H. Selective phosphorylation of the IP3R-I in vivo by cGMP-dependent protein kinase in smooth muscle. Am J Physiol Gastrointest Liver Physiol 2003; 284:G221-30. [PMID: 12529267 DOI: 10.1152/ajpgi.00401.2002] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This study examined the expression of inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R) types and PKG isoforms in isolated gastric smooth muscle cells and determined the ability of PKG and PKA to phosphorylate IP(3)Rs and inhibit IP(3)-dependent Ca(2+) release, which mediates the initial phase of agonist-induced contraction. PKG-Ialpha and PKG-Ibeta were expressed in gastric smooth muscle cells, together with IP(3)-R-associated cG-kinase substrate, a protein that couples PKG-Ibeta to IP(3)R-I. IP(3)R-I and IP(3)R-III were also expressed, but only IP(3)R-I was phosphorylated by PKA and PKG in vitro and exclusively by PKG in vivo. Sequential phosphorylation by PKA and by PKG-Ialpha in vitro showed that PKA phosphorylated the same site as PKG (presumably S(1755)) and an additional PKA-specific site (S(1589)). In intact muscle cells, agents that activated PKG or both PKG and PKA induced IP(3)R-I phosphorylation that was reversed by the PKG inhibitor (8R,9S,11s)-(-)-9-methoxy-carbamyl-8-methyl-2,3,9,10-tetrahydro-8,11-epoxy-1H,8H,1H,-2,7b,11a-trizadizo-benzo9(a,g)cycloocta(c,d,e)-trinden-1-one. Agents that activated PKA induced IP(3)R-I phosphorylation in permeabilized but not intact muscle cells, implying that PKA does not gain access to IP(3)R-I in intact muscle cells. The pattern of IP(3)R-I phosphorylation in vivo and in vitro was more consistent with phosphorylation by PKG-Ialpha. Phosphorylation of IP(3)R-I in microsomes by PKG, PKA, or a combination of PKG and PKA inhibited IP(3)-induced Ca(2+) release to the same extent, implying that inhibition was mediated by phosphorylation of the PKG-specific site. We conclude that IP(3)R-I is selectively phosphorylated by PKG-I in intact smooth muscle resulting in inhibition of IP(3)-dependent Ca(2+) release.
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Affiliation(s)
- Karnam S Murthy
- Department of Physiology, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 23298-0711, USA.
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Wang S, Shiva S, Poczatek MH, Darley-Usmar V, Murphy-Ullrich JE. Nitric oxide and cGMP-dependent protein kinase regulation of glucose-mediated thrombospondin 1-dependent transforming growth factor-beta activation in mesangial cells. J Biol Chem 2002; 277:9880-8. [PMID: 11784717 DOI: 10.1074/jbc.m108360200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Excessive transforming growth factor-beta (TGF-beta) activity in hyperglycemia contributes to the development of diabetic nephropathy. Glucose stimulation of TGF-beta activity and matrix synthesis are dependent on autocrine thrombospondin 1 (TSP1) to convert latent TGF-beta to its biologically active form. The mechanisms by which glucose regulates TSP1 are not known. High glucose inhibits nitric oxide (NO) bioavailability and decreased NO increases TGF-beta activity and extracellular matrix accumulation. Yet, the impact of NO signaling on TSP1 activation of TGF-beta is unknown. We tested the role of NO signaling in the regulation of TSP1 expression and TSP1-dependent TGF-beta activity in rat mesangial cells exposed to high glucose. On exposure to 30 mm glucose, NO accumulation in the conditioned media and intracellular cGMP levels were significantly decreased. The addition of an NO donor prevented the glucose-dependent increase in TSP1 mRNA, protein, and TGF-beta bioactivity. The effects of the NO donor were blocked by ODQ (a soluble guanylate cyclase inhibitor) or Rp-8-pCPT-cGMPS (an inhibitor of cGMP-dependent protein kinase). These effects of high glucose were also reversed by the nitric-oxide synthase cofactor tetrahyrobiopterin (BH(4)). These results show that high glucose mediates increases in TSP1 expression and TSP1-dependent TGF-beta bioactivity through down-modulation of NO-cGMP-dependent protein kinase signaling.
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Affiliation(s)
- Shuxia Wang
- Department of Pathology, Division of Molecular and Cellular Pathology, The Cell Adhesion and Matrix Research Center, University of Alabama, Birmingham 35294-0019, USA
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39
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Mazzetti L, Ruocco C, Giovannelli L, Ciuffi M, Franchi-Micheli S, Marra F, Zilletti L, Failli P. Guanosine 3': 5'-cyclic monophosphate-dependent pathway alterations in ventricular cardiomyocytes of spontaneously hypertensive rats. Br J Pharmacol 2001; 134:596-602. [PMID: 11588114 PMCID: PMC1572975 DOI: 10.1038/sj.bjp.0704275] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. We investigated the effect of the NO-donor S-nitroso-N-acetyl-DL-penicillamine (SNAP) on cardiomyocytes isolated from control normotensive Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats. 2. Ventricular cardiomyocytes were isolated from SHR and WKY hearts and imaging analysis of fura-2-loaded cells was performed in order to evaluate calcium transient in electrical field paced (0.5 Hz) cells. 3. In WKY cardiomyocytes, 1 - 200 microM SNAP dose-dependently increased cyclic GMP content. In basal conditions, cyclic GMP content of SHR cardiomyocytes was significantly higher than in WKY, but SNAP failed to further increase cyclic GMP over the basal level. 4. In control conditions, the Delta F/F and decay time of the calcium transient were similar in both strains. In WKY cardiomyocytes, SNAP (1 - 100 microM) reduced the decay time. In SHR cardiomyocytes, SNAP was ineffective. Dibutyryl cyclic GMP (10(-6) - 10(-8) M), a membrane permeable cyclic GMP analogue, behaved similarly to SNAP. 5. In WKY and SHR cardiomyocytes, 10(-8) M isoprenaline similarly increased Delta F/F and decreased the decay time. SNAP and dibutyryl cyclic GMP prevented the effect of isoprenaline in WKY, whereas both molecules were ineffective in SHR cardiomyocytes. In WKY, SNAP effects were blocked by pretreating cells with the cGK inhibitor KT-5823. 6. Western blotting analysis of cGK type I showed that the enzyme was expressed in WKY isolated cardiomyocytes, but absent in four out of five SHR preparations. 7. We concluded that the low expression of cGKI may determine the lack of NO/cyclic GMP-dependent regulation on calcium transient in SHR cardiomyocytes. This alteration may contribute to the development of heart hypertrophy in hypertensive status.
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Affiliation(s)
- Luca Mazzetti
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Carlo Ruocco
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Lisa Giovannelli
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Mario Ciuffi
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Sergio Franchi-Micheli
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Fabio Marra
- Department of Internal Medicine, Viale Morgagni, 85, University of Florence, 50139 Florence, Italy
| | - Lucilla Zilletti
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Paola Failli
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
- Author for correspondence:
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Lincoln TM, Dey N, Sellak H. Invited review: cGMP-dependent protein kinase signaling mechanisms in smooth muscle: from the regulation of tone to gene expression. J Appl Physiol (1985) 2001; 91:1421-30. [PMID: 11509544 DOI: 10.1152/jappl.2001.91.3.1421] [Citation(s) in RCA: 388] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
cGMP is a second messenger that produces its effects by interacting with intracellular receptor proteins. In smooth muscle cells, one of the major receptors for cGMP is the serine/threonine protein kinase, cGMP-dependent protein kinase (PKG). PKG has been shown to catalyze the phosphorylation of a number of physiologically relevant proteins whose function it is to regulate the contractile activity of the smooth muscle cell. These include proteins that regulate free intracellular calcium levels, the cytoskeleton, and the phosphorylation state of the regulatory light chain of smooth muscle myosin. Other studies have shown that vascular smooth muscle cells (VSMCs) that are cultured in vitro may cease to express PKG and will, coincidentally, acquire a noncontractile, synthetic phenotype. The restoration of PKG expression to the synthetic phenotype VSMC results in the cells acquiring a more contractile phenotype. These more recent studies suggest that PKG controls VSMC gene expression that, in turn, regulates phenotypic modulation of the cells. Therefore, the regulation of PKG gene expression appears to be linked to phenotypic modulation of VSMC. Because several vascular disorders are related to the accumulation of synthetic, fibroproliferative VSMC in the vessel wall, it is likely that changes in the activity of the nitric oxide/cGMP/PKG pathway is involved the development of these diseases.
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Affiliation(s)
- T M Lincoln
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0019, USA.
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41
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Mishra M, Wagner MB, Wang Y, Joyner RW, Kumar R. Expression of cGMP-dependent protein kinase in human atrium. J Mol Cell Cardiol 2001; 33:1467-76. [PMID: 11448135 DOI: 10.1006/jmcc.2001.1410] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have shown that cGMP-dependent protein kinase (PKG) mediates stimulation of L-type calcium current by cGMP in rabbit atrial myocytes. The human atrium may have similar PKG-dependent regulation of calcium current. To elucidate the significance of PKG in cardiac function, we have isolated human PKG type I alpha cDNA (+1 to 2016), determined the nucleotide sequence and analyzed specific expression of PKG in human atrium. We obtained full-length cDNA of PKG type I alpha from human atrial RNA using reverse transcriptase-polymerase chain reaction (RT-PCR). The coding region of human cardiac PKG I alpha showed 99.9% homology to previously published human PKG I alpha except for base No. 1983. At this position G was substituted for T and this resulted in an amino acid substitution from Leu649 to Phe649. The cloned PKG I alpha cDNA was expressed in COS cells and the expressed PKG showed cGMP-stimulated PKG enzyme activity and immunoreactivity. Ribonuclease protection assay, Western blot analysis, and PKG enzyme activity assays in homogenates from human atrial tissue demonstrated the presence of PKG mRNA and protein in human atrial tissue. Immunofluorescence staining confirmed that PKG is highly expressed in human atrial myocytes. These findings suggest that PKG is highly expressed in human atrium and that PKG-dependent phosphorylation may be important in regulation of calcium channel activity in human atrial myocytes.
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Affiliation(s)
- M Mishra
- The Todd Franklin Cardiac Research Laboratory, The Sibley Children's Heart Center, Department of Pediatrics, 2040 Ridgewood Dr. NE, Atlanta, GA 30322, USA
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Sawada N, Itoh H, Yamashita J, Doi K, Inoue M, Masatsugu K, Fukunaga Y, Sakaguchi S, Sone M, Yamahara K, Yurugi T, Nakao K. cGMP-dependent protein kinase phosphorylates and inactivates RhoA. Biochem Biophys Res Commun 2001; 280:798-805. [PMID: 11162591 DOI: 10.1006/bbrc.2000.4194] [Citation(s) in RCA: 186] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Small GTPase Rho and cGMP/cGMP-dependent protein kinase (cGK) pathways exert opposing effects in specific systems such as vascular contraction and growth. However, the direct interaction between these pathways has remained elusive. We demonstrate that cGK phosphorylates RhoA in vitro at Ser188, the same residue phosphorylated by cAMP-dependent protein kinase. In HeLa cells transfected with constitutively active cGK (C-cGK), stress fiber formation induced by lysophosphatidic acid or V14RhoA was blocked. By contrast, C-cGK failed to inhibit stress fiber formation in cells transfected with mutant RhoA with substitution of Ser188 to Ala. C-cGK did not affect actin reorganization induced by Rac1 or Rho-associated kinase, one of the effectors for RhoA. Furthermore, C-cGK expression inhibited the membrane translocation of RhoA. Collectively, our findings suggest that cGK phosphorylates RhoA at Ser188 and inactivates RhoA signaling. The physiological relevance of the direct interaction between RhoA and cGK awaits further investigation.
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Affiliation(s)
- N Sawada
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
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43
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Abstract
The endothelium plays a pivotal role in many physiological and pathological processes and is known to be an exceptionally active transcriptional site. To advance our understanding of endothelial cell biology and to elucidate potential pharmaceutical targets, we developed a new database screening approach to permit identification of novel endothelial-specific genes. The UniGene gene index was screened using high stringency BLAST against a pool of endothelial expressed sequence tags (ESTs) and a pool of nonendothelial ESTs constructed from cell-type-specific dbEST libraries. UniGene clusters with matches in the endothelial pool and no matches in the nonendothelial pool were selected. The UniGene/EST approach was then combined with serial analysis of gene expression (SAGE) library subtraction and reverse transcription polymerase chain reaction to further examine interesting clusters. Four novel genes were identified and labeled: endothelial cell-specific molecules (ECSM) 1-3 and magic roundabout (similar to the axon guidance protein roundabout). In summary, we present a powerful novel approach for comparative expression analysis combining two datamining strategies followed by experimental verification.
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Affiliation(s)
- L Huminiecki
- Molecular Angiogenesis Laboratory, Imperial Cancer Research Fund, Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
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44
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Abstract
Contraction and relaxation of smooth muscle is a tightly regulated process involving numerous endogenous substances and their intracellular second messengers. We examine the key role of cyclic guanosine monophosphate (cGMP) in mediating smooth muscle relaxation. We briefly review the current art regarding cGMP generation and degradation, while focusing on the recent identification of the molecular mechanisms underlying cGMP-mediated smooth muscle relaxation. cGMP-induced SM relaxation is mediated mainly by cGMP-dependent protein kinase activation. It involves several molecular events culminating in a reduction in intracellular Ca(2+) concentration and a decrease in the sensitivity of the contractile system to Ca(2+). We propose that the cGMP-induced decrease in Ca(2+) sensitivity is a strategic way to achieve "active relaxation" of the smooth muscle. In summary, we present compelling evidence supporting a key role for cGMP as a mediator of smooth muscle relaxation in physiological and pharmacological settings.
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Affiliation(s)
- J A Carvajal
- Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of Maryland-Baltimore, Baltimore, Maryland 21201, USA.
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45
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Browning DD, McShane MP, Marty C, Ye RD. Nitric oxide activation of p38 mitogen-activated protein kinase in 293T fibroblasts requires cGMP-dependent protein kinase. J Biol Chem 2000; 275:2811-6. [PMID: 10644746 DOI: 10.1074/jbc.275.4.2811] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
An increase in cellular levels of cyclic nucleotides activates serine/threonine-dependent kinases that lead to diverse physiological effects. Recently we reported the activation of the p38 mitogen-activated protein kinase (MAPK) pathway in neutrophils by a cGMP-dependent mechanism. In this study we demonstrated that exogenously supplied nitric oxide leads to activation of p38 MAPK in 293T fibroblasts. Phosphorylation of p38 corresponded with an increase in ATF-2-dependent gene expression. The effect of nitric oxide was mimicked by addition of 8-bromo-cGMP, indicating that activation of soluble guanylyl cyclase was involved. The importance of cGMP-dependent protein kinase in the activation of p38 MAPK by nitric oxide in 293T cells was assessed in a transfection based assay. Overexpression of cGMP-dependent protein kinase-1alpha caused phosphorylation of p38 in these cells and potentiated the effectiveness of cGMP. Overexpression of a catalytically inactive mutant form of this enzyme (T516A) blocked the ability of both nitric oxide and 8-bromo-cGMP to activate p38 as measured by both p38 phosphorylation and ATF-2 driven gene expression. Together, these data demonstrate that nitric oxide stimulates a novel pathway leading to activation of p38 MAPK that requires activation of cGMP-dependent protein kinase.
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Affiliation(s)
- D D Browning
- Department of Pharmacology, MC868, University of Illinois at Chicago, Chicago, Illinois 60612, USA
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46
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Surks HK, Mochizuki N, Kasai Y, Georgescu SP, Tang KM, Ito M, Lincoln TM, Mendelsohn ME. Regulation of myosin phosphatase by a specific interaction with cGMP- dependent protein kinase Ialpha. Science 1999; 286:1583-7. [PMID: 10567269 DOI: 10.1126/science.286.5444.1583] [Citation(s) in RCA: 393] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Contraction and relaxation of smooth muscle are regulated by myosin light-chain kinase and myosin phosphatase through phosphorylation and dephosphorylation of myosin light chains. Cyclic guanosine monophosphate (cGMP)-dependent protein kinase Ialpha (cGKIalpha) mediates physiologic relaxation of vascular smooth muscle in response to nitric oxide and cGMP. It is shown here that cGKIalpha is targeted to the smooth muscle cell contractile apparatus by a leucine zipper interaction with the myosin-binding subunit (MBS) of myosin phosphatase. Uncoupling of the cGKIalpha-MBS interaction prevents cGMP-dependent dephosphorylation of myosin light chain, demonstrating that this interaction is essential to the regulation of vascular smooth muscle cell tone.
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Affiliation(s)
- H K Surks
- Molecular Cardiology Research Institute and Cardiology Division, Department of Medicine, Tufts University School of Medicine and New England Medical Center, Boston, MA 02111, USA
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47
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Nakamura M, Ichikawa K, Ito M, Yamamori B, Okinaka T, Isaka N, Yoshida Y, Fujita S, Nakano T. Effects of the phosphorylation of myosin phosphatase by cyclic GMP-dependent protein kinase. Cell Signal 1999; 11:671-6. [PMID: 10530875 DOI: 10.1016/s0898-6568(99)00036-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cyclic GMP-dependent protein kinase (PKG) phosphorylated, in vitro, the large (MYPT1) and small (M20) regulatory subunits of myosin phosphatase (MP) with maximum stoichiometries of 1.8 and 0.6 mol of phosphate/mol subunit, respectively. The phosphorylation of these subunits by PKG did not affect the phosphatase activity towards the 20 kDa myosin light chain. However, phosphorylation of the MP holoenzyme decreased the binding of MP to phospholipid. The phosphorylation of the serine residue of the C-terminal part of MYPT1 was crucial for these interactions. These results suggest that the phosphorylation of MP by PKG is not a direct mechanism in activating MP activity, and that other indirect mechanisms, including the interaction between MP and phospholipids, might be candidates for Ca2+ desensitization via cGMP in smooth muscle.
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Affiliation(s)
- M Nakamura
- First Department of Internal Medicine, Mie University School of Medicine, Tsu, Japan
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48
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Idriss SD, Gudi T, Casteel DE, Kharitonov VG, Pilz RB, Boss GR. Nitric oxide regulation of gene transcription via soluble guanylate cyclase and type I cGMP-dependent protein kinase. J Biol Chem 1999; 274:9489-93. [PMID: 10092632 DOI: 10.1074/jbc.274.14.9489] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nitric oxide (NO) regulates the expression of multiple genes but in most cases its precise mechanism of action is unclear. We used baby hamster kidney (BHK) cells, which have very low soluble guanylate cyclase and cGMP-dependent protein kinase (G-kinase) activity, and CS-54 arterial smooth muscle cells, which express these two enzymes, to study NO regulation of the human fos promoter. The NO-releasing agent Deta-NONOate (ethanamine-2,2'-(hydroxynitrosohydrazone)bis-) had no effect on a chloramphenicol acetyltransferase (CAT) reporter gene under control of the fos promoter in BHK cells transfected with an empty vector or in cells transfected with a G-kinase Ibeta expression vector. In BHK cells transfected with expression vectors for guanylate cyclase, Deta-NONOate markedly increased the intracellular cGMP concentration and caused a small (2-fold) increase in CAT activity; the increased CAT activity appeared to be from cGMP activation of cAMP-dependent protein kinase. In BHK cells co-transfected with guanylate cyclase and G-kinase expression vectors, CAT activity was increased 5-fold in the absence of Deta-NONOate and 7-fold in the presence of Deta-NONOate. Stimulation of CAT activity in the absence of Deta-NONOate appeared to be largely from endogenous NO since we found that: (i) BHK cells produced high amounts of NO; (ii) CAT activity was partially inhibited by a NO synthase inhibitor; and (iii) the inhibition by the NO synthase inhibitor was reversed by exogenous NO. In CS-54 cells, we found that NO increased fos promoter activity and that the increase was prevented by a guanylate cyclase inhibitor. In summary, we found that NO activates the fos promoter by a guanylate cyclase- and G-kinase-dependent mechanism.
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Affiliation(s)
- S D Idriss
- Department of Pediatrics, University of California, San Diego, La Jolla, California 92093-0652, USA
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49
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Collins SP, Uhler MD. Cyclic AMP- and cyclic GMP-dependent protein kinases differ in their regulation of cyclic AMP response element-dependent gene transcription. J Biol Chem 1999; 274:8391-404. [PMID: 10085070 DOI: 10.1074/jbc.274.13.8391] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ability of cGMP-dependent protein kinases (cGKs) to activate cAMP response element (CRE)-dependent gene transcription was compared with that of cAMP-dependent protein kinases (cAKs). Although both the type Ibeta cGMP-dependent protein kinase (cGKIbeta) and the type II cAMP-dependent protein kinase (cAKII) phosphorylated the cytoplasmic substrate VASP (vasodilator- and A kinase-stimulated phosphoprotein) to a similar extent, cyclic nucleotide regulation of CRE-dependent transcription was at least 10-fold higher in cAKII-transfected cells than in cGKIbeta-transfected cells. Overexpression of each kinase in mammalian cells resulted in a cytoplasmic localization of the unactivated enzyme. As reported previously, the catalytic (C) subunit of cAKII translocated to the nucleus following activation by 8-bromo-cyclic AMP. However, cGKIbeta did not translocate to the nucleus upon activation by 8-bromo-cyclic GMP. Replacement of an autophosphorylated serine (Ser79) of cGKIbeta with an aspartic acid resulted in a mutant kinase with constitutive kinase activity in vitro and in vivo. The cGKIbetaS79D mutant localized to the cytoplasm and was only a weak activator of CRE-dependent gene transcription. However, an amino-terminal deletion mutant of cGKIbeta was found in the nucleus as well as the cytoplasm and was a strong activator of CRE-dependent gene transcription. These data suggest that the inability of cGKs to translocate to the nucleus is responsible for the differential ability of cAKs and cGKs to activate CRE-dependent gene transcription and that nuclear redistribution of cGKs is not required for NO/cGMP regulation of gene transcription.
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Affiliation(s)
- S P Collins
- Department of Biological Chemistry and the Mental Health Research Institute, University of Michigan, Ann Arbor, Michigan 48109, USA
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50
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Chiche JD, Schlutsmeyer SM, Bloch DB, de la Monte SM, Roberts JD, Filippov G, Janssens SP, Rosenzweig A, Bloch KD. Adenovirus-mediated gene transfer of cGMP-dependent protein kinase increases the sensitivity of cultured vascular smooth muscle cells to the antiproliferative and pro-apoptotic effects of nitric oxide/cGMP. J Biol Chem 1998; 273:34263-71. [PMID: 9852090 DOI: 10.1074/jbc.273.51.34263] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Studies in vitro have underestimated the importance of cGMP-dependent protein kinase (PKG) in the modulation of vascular smooth muscle cell (SMC) proliferation and apoptosis in vivo. This is attributable, in part, to a rapid decline in PKG levels as vascular SMC are passaged in culture. We used a recombinant adenovirus encoding PKG (Ad.PKG) to augment kinase activity in cultured rat pulmonary artery SMC (RPaSMC). Incubation of Ad. PKG-infected RPaSMC (multiplicity of infection = 200) with 8-Br-cGMP decreased serum-stimulated DNA synthesis by 85% and cell proliferation at day 5 by 74%. The effect of 8-Br-cGMP on DNA synthesis in Ad.PKG-infected RPaSMC was blocked by KT5823 (PKG inhibitor), but not by KT5720 (cAMP-dependent protein kinase inhibitor). A nitric oxide (NO) donor compound, S-nitrosoglutathione, at concentrations as low as 100 nM, inhibited DNA synthesis in Ad. PKG-infected RPaSMC, but not in uninfected cells or in cells infected with a control adenovirus. In addition, 8-Br-cGMP and S-nitrosoglutathione induced apoptosis in serum-deprived RPaSMC infected with Ad.PKG, but not in uninfected cells or in cells infected with a control adenovirus. These results demonstrate that modulation of PKG levels in vascular SMC can alter the sensitivity of these cells to NO and cGMP. Moreover, these observations suggest an important role for PKG in the regulation of vascular SMC proliferation and apoptosis by NO and cGMP.
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Affiliation(s)
- J D Chiche
- Department of Anesthesia and Critical Care, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA. chiche@etherdome
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