The Origin

“It is much more important to know what sort of a patient has a disease than what sort of a disease a patient has.”

---Sir William Osler---

Sunday, August 17, 2008

11ß-Hydroxysteroid dehydrogenase type 2 & Hypertension

Epigenetic control of 11 beta-hydroxysteroid dehydrogenase 2 gene promoter is related to human hypertension.
Atherosclerosis. 2008 Aug;199(2):323-7. Epub 2008 Feb 7.
Friso S, Pizzolo F, Choi SW, Guarini P, Castagna A, Ravagnani V, Carletto A, Pattini P, Corrocher R, Olivieri O.
Department of Clinical and Experimental Medicine, University of Verona School of Medicine, Verona, Italy. simonetta.friso@univr.it
BACKGROUND: Lower activity of 11 beta-hydroxysteroid dehydrogenase 2 (11beta-HSD2) classically induces hypertension by leading to an altered tetrahydrocortisol- versus tetrahydrocortisone-metabolites (THFs/THE) shuttle. Recent cell culture and animal studies suggest a role for promoter methylation, a major epigenetic feature of DNA, in regulation of HSD11B2 expression. Little is known, however, of human HSD11B2 epigenetic control and its relationship with the onset of hypertension. OBJECTIVE: To explore the possible relevance of HSD11B2 promoter methylation, by examining human peripheral blood mononuclear cell (PBMC) DNA and urinary THFs/THE ratio as a biochemical indicator of 11beta-HSD2 activity, in blood pressure control. METHODS: Twenty-five essential hypertensives and 32 subjects on prednisone therapy were analyzed, the latter to investigate 11beta-HSD2 function in the development of hypertension. RESULTS: Elevated HSD11B2 promoter methylation was associated with hypertension developing in glucocorticoid-treated patients in parallel with a higher urinary THFs/THE ratio. Essential hypertensives with elevated urinary THFs/THE ratio also showed higher HSD11B2 promoter methylation. CONCLUSIONS: These results show a clear link between the epigenetic regulation through repression of HSD11B2 in PBMC DNA and hypertension.
PMID: 18178212 [PubMed - in process]



Analysis of the 11beta-hydroxysteroid dehydrogenase type 2 gene (HSD11B2) in human essential hypertension.
Am J Hypertens. 2005 Aug;18(8):1091-8.
Mariniello B, Ronconi V, Sardu C, Pagliericcio A, Galletti F, Strazzullo P, Palermo M, Boscaro M, Stewart PM, Mantero F, Giacchetti G.
Division of Endocrinology, Department of Internal Medicine, Università Politecnica delle Marche, Umberto I Hospital, Ancona, Italy.
BACKGROUND: The HSD11B2 gene, encoding the kidney isoenzyme 11beta-hydroxysteroid dehydrogenase, is a candidate for essential hypertension. We previously showed that the frequency of shorter alleles of a CA repeat polymorphism in the first intron of 11beta-HSD2 gene was significantly higher among salt-sensitive than salt-resistant individuals with hypertension. The aim of the study was to analyze the HSD11B2 gene to assess whether some of its variants might be involved in hypertension. METHODS: Exons 2, 3, 4, and 5 were screened by polymerase chain reaction-single-strand conformation polymorphism analysis in 292 hypertensive patients and 163 control subjects. The samples with variant electrophoretic patterns at single-strand conformation polymorphism were re-analyzed using an automated DNA sequencer. A case-control study was then performed by comparing genotype frequencies in hypertensive and normotensive subjects. RESULTS: Analysis of the HSD11B2 showed that in hypertensive patients there is a higher prevalence of two associated polymorphisms, Thr156/Thr(C468A) in exon 2 (ex2) and Glu178/Glu(G534A) in exon 3 (ex3), than in normotensive subjects (9% v 2.4%). This association did not correlate with salt sensitivity. C468A alone correlates significantly with hypertension (9%) and was identified only in 3% of control subjects (P < .05), whereas G534A was identified also in about 7% of normotensive subjects. The urinary free cortisol/urinary free cortisone ratio (UFF/UFE) was significantly higher in hypertensive patients compared with control subjects (P < .01). CONCLUSIONS: Two different polymorphisms of the HSD11B2 gene were observed. The association of both polymorphisms was significantly higher in hypertensive subjects than in control subjects. Its role should be further investigated, but it could be related to other mutations in the promoter region of HSD11B2 or to the modulation of 11beta-HSD2 mRNA processing in hypertensive subjects.
PMID: 16109323 [PubMed - indexed for MEDLINE]



Role of HSD11B2 polymorphisms in essential hypertension and the diuretic response to thiazides.
Kidney Int. 2005 Feb;67(2):631-7.
Williams TA, Mulatero P, Filigheddu F, Troffa C, Milan A, Argiolas G, Parpaglia PP, Veglio F, Glorioso N.
Hypertension Unit, Department of Medicine and Experimental Oncology, University of Torino, Torino, Italy.
BACKGROUND: The renal 11beta-hydroxysteroid dehydrogenase type 2 (11beta HSD2) enzyme inactivates 11-hydroxy steroids in the kidney, thereby protecting the nonselective mineralocorticoid (MR) receptor from occupation by glucocorticoids. Loss-of-function mutations in the gene encoding 11beta HSD2 (HSD11B2) result in overstimulation of the MR and cause salt-sensitive hypertension. METHODS: We have investigated the role of HSD11B2 in hypertension in 377 genetically homogeneous essential hypertensives from North Sardinia. RESULTS: Thirty of these patients displayed increased urinary cortisol metabolite ratios (greater than or equal to 2) (tetrahydrocortisol [THF]+allotetrahydrocortisol [aTHF]/tetrahydrocortisone [THE]) reflecting a mild reduction in 11beta HSD2 activity. No mutations in HSD11B2 were detected in these patients. All 377 patients were genotyped for a CA repeat microsatellite in intron 1 of HSD11B2 and a G534A polymorphism in exon 3 of HSD11B2. CA repeat length was associated with the (THF+aTHF)/THE ratio, which in turn was significantly related to PRA levels. No associations were found between the G354A polymorphism and the other parameters. There were no differences in blood pressure (BP) levels between HSD11B2 genotypes, but in a subgroup of 91 patients that underwent diuretic therapy, CA repeat length was strongly associated with the BP response to hydrochlorothiazide. CONCLUSION: This study highlights the role of this HSD11B2 polymorphism in sodium handling and is consistent with a role in the BP response to thiazide diuretics.
PMID: 15673310 [PubMed - indexed for MEDLINE]



Identification of polymorphisms in the human 11beta-hydroxysteroid dehydrogenase type 2 gene promoter: functional characterization and relevance for salt sensitivity
The FASEB Journal. 2007;21:3618-3628.
Rasoul Alikhani-Koupaei*, Fatemeh Fouladkou*, Pierre Fustier*, Bruno Cenni, Arya M. Sharma, Hans-Christian Deter, Brigitte M. Frey*,1 and Felix J. Frey*
* Nephrology and Hypertension and Clinical Research; Institute for Clinical Chemistry, University Hospital of Berne, Berne, Switzerland; Canada Research Chair for Cardiovascular Obesity Research and Management, McMaster University, Hamilton General Hospital, Hamilton, Ontario, Canada; and Department of Psychosomatics and Psychotherapy, Charité Campus Benjamin Franklin, Berlin
1Correspondence: Department of Nephrology and Hypertension, University Hospital, Freiburgstrasse 15, 3010 Bern-Inselspital, Switzerland. E-mail:
brigitte.frey@dkf.unibe.ch
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Reduced activity of 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) plays a role in essential hypertension and the sensitivity of blood pressure to dietary salt. Nonconservative mutations in the coding region are extremely rare and do not explain the variable 11beta-HSD2 activity. We focused therefore on the 5'-regulatory region and identified and characterized the first promoter polymorphisms. Transfections of variants G-209A and G-126A into SW620 cells reduced promoter activity and affinity for activators nuclear factor 1 (NF1) and Sp1. Chromatin immunoprecipitation revealed Sp1, NF1, and glucocorticoid receptor (GR) binding to the HSD11B2 promoter. Dexamethasone induced expression of mRNA and activity of HSD11B2. GR and/or NF1 overexpression increased endogenous HSD11B2 mRNA and activity. GR complexes cooperated with NF1 to activate HSD11B2, an effect diminished in the presence of the G-209A variant. When compared to salt-resistant subjects (96), salt-sensitive volunteers (54) more frequently had the G-209A variant, higher occurrence of alleles A4/A7 of polymorphic microsatellite marker, and higher urinary ratios of cortisol to cortisone metabolites. First, we conclude that the mechanism of glucocorticoid-induced HSD11B2 expression is mainly mediated by cooperation between GR and NF1 on the HSD11B2 promoter and, second, that the newly identified promoter variants reduce activity and cooperation of cognate transcription factors, resulting in diminished HSD11B2 transcription, an effect favoring salt sensitivity.—Alikhani-Koupaei, R., Fouladkou, F., Fustier, P., Cenni, B., Sharma, A. M., Deter, H.-C., Frey, B. M., Frey, F. J. Identification of polymorphisms in the human 11beta-hydroxysteroid dehydrogenase type 2 gene promoter: functional characterization and relevance for salt sensitivity.



11ß-Hydroxysteroid dehydrogenase type 2 activity is associated with left ventricular mass in essential hypertension.
European Heart Journal 2005 26(5):498-504; doi:10.1093/eurheartj/ehi070
Nicola Glorioso1,*, Fabiana Filigheddu1, Paolo Pinna Parpaglia2, Aldo Soro1, Chiara Troffa1, Giuseppe Argiolas1 and Paolo Mulatero3
1Hypertension and Cardiovascular Prevention Centre, ASL n.1-University of Sassari, Italy2Emergency Department, ASL n.1, Sassari, Italy3Hypertension Centre, University of Torino, Italy
Received 9 July 2004; revised 4 October 2004; accepted 28 October 2004; online publish-ahead-of-print 15 December 2004.
* Corresponding author. Tel:/fax: +39 079 228388. E-mail address: glorioso@uniss.it
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Aims Left ventricular mass (LVM) is under the control of aldosterone and angiotensin II in experimental hypertension, but the effect of aldosterone on LVM is controversial in essential hypertension (EH). Some EH patients show a mild impairment of 11ß-hydroxysteroid dehydrogenase type 2 (11ß-HSD2) activity without clinical features of the syndrome of apparent mineralocorticoid excess, where the incomplete cortisol-to-cortisone conversion leads to glucocorticoid-mediated mineralocorticoid effects. The mineralocorticoid receptor and 11ß-HSD2 are co-expressed in human heart. We investigated whether LVM may be regulated by glucocorticoids in EH patients.
Methods and results The ratio between 24 h urinary tetrahydro derivatives of cortisol and cortisone (THFs/THE), plasma renin activity, 24 h urinary aldosterone, blood pressure, and LVM indexed for height2.7 (LVMh2.7) were analysed in 493 never-treated hypertensives and 98 normotensives. THFs/THE was associated with LVMh2.7 in hypertensives and normotensives (r=0.32, P<0.001, and r=0.17, P=0.04, respectively) and persisted after adjusting for confounders (multiple regression analysis). Body mass index, sex, recumbent plasma renin activity, and THFs/THE accounted for 26.1% of LVMh2.7 variation. Urinary aldosterone was not correlated with LVMh2.7.
Conclusion We suggest that glucocorticoids may take part in the regulation of LVM in EH patients as a function of 11ß-HSD2 activity, and contribute to the target organ damage associated with essential hypertension.


Link for Full Text: http://eurheartj.oxfordjournals.org/cgi/reprint/26/5/498

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