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Gc JB, Szlenk CT, Diyaolu A, Obi P, Wei H, Shi X, Gibson KM, Natesan S, Roullet JB. Allosteric modulation of α1β3γ2 GABA A receptors by farnesol through the neurosteroid sites. Biophys J 2023; 122:849-867. [PMID: 36721367 PMCID: PMC10027449 DOI: 10.1016/j.bpj.2023.01.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 12/13/2022] [Accepted: 01/23/2023] [Indexed: 02/02/2023] Open
Abstract
In mammalian cells, all-trans farnesol, a 15-carbon isoprenol, is a product of the mevalonate pathway. It is the natural substrate of alcohol dehydrogenase and a substrate for CYP2E1, two enzymes implicated in ethanol metabolism. Studies have shown that farnesol is present in the human brain and inhibits voltage-gated Ca2+ channels at much lower concentrations than ethanol. Here we show that farnesol modulates the activity of γ-aminobutyric acid type A receptors (GABAARs), some of which also mediate the sedative activity of ethanol. Electrophysiology experiments performed in HEK cells expressing human α1β3γ2 or α6β3γ2 GABAARs revealed that farnesol increased chloride currents through positive allosteric modulation of these receptors and showed dependence on both the alcoholic functional group of farnesol and the length of the alkyl chain for activity. In silico studies using long-timescale unbiased all-atom molecular dynamics (MD) simulations of the human α1β3γ2 GABAA receptors revealed that farnesol modulates the channel by directly binding to the transmembrane neurosteroid-binding site, after partitioning into the surrounding membrane and reaching the receptor by lateral diffusion. Channel activation by farnesol was further characterized by several structural and dynamic variables, such as global twisting of the receptor's extracellular domain, tilting of the transmembrane M2 helices, radius, cross-sectional area, hydration status, and electrostatic potential of the channel pore. Our results expand the pharmacological activities of farnesol to yet another class of ion channels implicated in neurotransmission, thus providing a novel path for understanding and treatment of diseases involving GABAA receptor dysfunction.
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Affiliation(s)
- Jeevan B Gc
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Christopher T Szlenk
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Ayobami Diyaolu
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Peter Obi
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Haiyang Wei
- Eurofins Panlabs, Inc., St. Charles, Missouri
| | - Xutong Shi
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - K Michael Gibson
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Senthil Natesan
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington.
| | - Jean-Baptiste Roullet
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington.
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Alghamdi J, Alqadi A, Alharf A, Almuzzaini B, Mahmud A, Barhoumi T, Badreldin HA, Alaamery M, Padmanabhan S. Blood pressure–lowering activity of statins: a systematic literature review and meta-analysis of placebo-randomized controlled trials. Eur J Clin Pharmacol 2020; 76:1745-1754. [DOI: 10.1007/s00228-020-02965-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 07/16/2020] [Indexed: 01/28/2023]
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Kaleli-Durman D, Alp-Yıldırım Fİ, Özdemir O, Uydeş-Doğan BS. Relaxant effect of atorvastatin on isolated rat gastric fundus strips: implications for Ca 2+-signalling mechanisms. Can J Physiol Pharmacol 2019; 97:413-421. [DOI: 10.1139/cjpp-2018-0723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Statins are determined to have various pleiotropic effects apart from their lipid-lowering properties. Herein, we investigated the direct effects of atorvastatin on gastric smooth muscle tone. Atorvastatin effectively relaxed isolated rat gastric fundus strips precontracted with acetylcholine, potassium chloride, and serotonin. Incubation of the strips with nitric oxide synthase inhibitor, l-NOARG (10−4 M, 20 min), l-type voltage-operated Ca2+ channel (VOCC) blocker, nifedipine (10−6 M, 30 min), KATP channel blocker, glibenclamide (10−5 M, 30 min), or precursor of cholesterol, mevalonate (10−2 M, 45 min) did not change the relaxations to atorvastatin. However, pretreatment of fundus strips with atorvastatin (3×10−5–3×10−4 M, 30 min) inhibited the contractions to calcium chloride (10−4–10−1 M), acetylcholine (10–4 M), and caffeine (20 mM) in the calcium-free medium. Moreover, atorvastatin reduced the contractions induced by sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) inhibitor, cyclopiazonic acid (10−7–3×10−5 M). The current study demonstrated that atorvastatin produces an acute relaxant effect on gastric fundus strips, which appears to be mediated by several Ca2+-signalling mechanisms such as the blockade of l-type VOCC-independent Ca2+ entry, decrease in smooth muscle Ca2+ sensitivity, inhibition of IP3- and ryanodine-sensitive intracellular stores to mediate Ca2+ release, as well as the activation of SERCA. This acute relaxing effect seems unlikely to be related with nitric oxide, KATP channels, and the mevalonate pathway.
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Affiliation(s)
- Deniz Kaleli-Durman
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, 34116, Beyazıt, Istanbul, Turkey
| | - F. İlkay Alp-Yıldırım
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, 34116, Beyazıt, Istanbul, Turkey
| | - Osman Özdemir
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, 34116, Beyazıt, Istanbul, Turkey
- Department of Pharmacology, Faculty of Health Sciences, Cyprus International University, Lefkoşa, North Cyprus, Cyprus
| | - B. Sönmez Uydeş-Doğan
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, 34116, Beyazıt, Istanbul, Turkey
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Scoppola A, Galiano P. The Mevalonate Pathway and Renal Diseases: Experimental and Clinical Implications. Int J Artif Organs 2018. [DOI: 10.1177/039139889802100506] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- A. Scoppola
- Department of Internal Medicine and Cardiology I.D.I. (IRCCS), Roma - Italy
| | - P. Galiano
- Department of Internal Medicine and Cardiology I.D.I. (IRCCS), Roma - Italy
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Alp Yildirim Fİ, Kaleli Durman D, Aypar E, Ark M, Özdemir O, Uydeş Doğan BS. Atorvastatin acutely reduces the reactivity to spasmogens in rat aorta: implication of the inhibition of geranylgeranylation and MYPT-1 phosphorylation. Fundam Clin Pharmacol 2016; 30:96-106. [DOI: 10.1111/fcp.12173] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 11/03/2015] [Accepted: 11/20/2015] [Indexed: 12/17/2022]
Affiliation(s)
- Fatoş İlkay Alp Yildirim
- Department of Pharmacology; Faculty of Pharmacy; Istanbul University; 34116, Beyazit, Istanbul Turkey
| | - Deniz Kaleli Durman
- Department of Pharmacology; Faculty of Pharmacy; Istanbul University; 34116, Beyazit, Istanbul Turkey
| | - Eda Aypar
- Department of Pharmacology; Faculty of Pharmacy; Gazi University; 06330, Etiler, Ankara Turkey
| | - Mustafa Ark
- Department of Pharmacology; Faculty of Pharmacy; Gazi University; 06330, Etiler, Ankara Turkey
| | - Osman Özdemir
- Department of Pharmacology; Faculty of Pharmacy; Istanbul University; 34116, Beyazit, Istanbul Turkey
- Department of Pharmacology; Faculty of Health Sciences; Cyprus International University; Lefkoşa North Cyprus Cyprus
| | - Birsel Sönmez Uydeş Doğan
- Department of Pharmacology; Faculty of Pharmacy; Istanbul University; 34116, Beyazit, Istanbul Turkey
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Tarhzaoui K, Valensi P, Leger G, Cohen-Boulakia F, Lestrade R, Behar A. Rosuvastatin positively changes nerve electrophysiology in diabetic rats. Diabetes Metab Res Rev 2009; 25:272-8. [PMID: 19172598 DOI: 10.1002/dmrr.920] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE To examine the effect of rosuvastatin on peripheral nerve function in diabetic rats using electrophysiological measurements. BACKGROUND Diabetes was induced in 5-day-old male Wistar rats by intraperitoneal (i.p.) injection of streptozotocin (STZ). As many as 45 diabetic rats were randomized to three groups: one treated with rosuvastatin (group R), another with rosuvastatin and mevalonate (group MR) and the other was untreated (group U). The data were compared with a group of normal age-matched rats i.e. control rats (group C). METHODS Neurophysiological measurements were performed at the age of 3 months (T1) and again at the age of 8 months (T2), after 3 months of treatment. RESULTS At T1, there was a trend to lower amplitude of compound motor action potential (CMAP) in the three diabetic groups as compared to controls, and no difference for motor nerve conduction velocity (MNCV), amplitude of sensory nerve action potential (SNAP), sensory nerve conduction velocity (SNCV) between diabetic groups and controls. At T2, the amplitude of CMAP was significantly lower in groups R and MR versus group U and control rats. MNCV was significantly and similarly decreased in the three diabetic groups; the latency of the first sensory peak (fastest sensory fibres) was significantly increased in group U but was normal in groups R and MR. CONCLUSIONS This study shows that: 1.rosuvastatin exerts a beneficial effect on the conduction of the fastest sensory fibres;2.these effects are independent of blood pressure and lipid changes.
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Affiliation(s)
- K Tarhzaoui
- Laboratory of Nutrition, Metabolic Diseases and Cardiovascular Prevention, Paris Nord University, CRNH-IdF, Bobigny, France
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Davis L, Roullet JB, Thornburg KL, Shokry M, Hohimer AR, Giraud GD. Augmentation of coronary conductance in adult sheep made anaemic during fetal life. J Physiol 2003; 547:53-9. [PMID: 12562949 PMCID: PMC2342629 DOI: 10.1113/jphysiol.2002.023283] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Maximal coronary conductance with adenosine in anaemic fetal sheep is twice that of non-anaemic fetuses. To investigate whether this increase in conductance persists into adulthood we studied twin sheep as fetuses and again as adults. Nine anaemic fetuses (118 days gestation) underwent isovolaemic haemorrhage for 18.0 +/- 4.6 days (means +/- S.D.) during which time the haematocrit was reduced from 39.9 +/- 5.2 % to 16.3 +/- 3.4 % and oxygen content from 8.6 +/- 1.3 to 2.3 +/- 0.2 ml dl-1. At 138 days the anaemic fetuses were transfused; at delivery the haematocrit was 29.3 +/- 6.8 % compared to nine control fetuses in which the haematocrit was 38.5 +/- 4.3 %. The weight at delivery was 3.5 +/- 0.36 kg in the anaemic fetuses vs. 4.2 +/- 0.83 kg in controls. Twenty-eight weeks later, we placed an occluder on the descending thoracic aorta and inferior vena cava, a flow probe around the proximal left circumflex coronary artery, and catheters in the left atrial appendage, jugular and carotid vessels. Maximal coronary conductance was determined in the adults by recording coronary blood flow as driving pressure was altered by inflating the occluders while adenosine was infused into the left atrium. Right atrial, left atrial, systolic and mean arterial pressures, systemic vascular resistance and haematocrit were not different between 'in utero anaemic' and control adults. The adults that were anaemic in utero weighed less than the controls 39.4 +/- 4.6 kg vs. 45.0 +/- 5.6 kg. Maximal conductance was greater in the adults that were anaemic in utero: 11.2 +/- 4.0 ml min(-1) (100 g)(-1) mmHg-1 as compared to 6.1 +/- 1.8 ml min(-1) (100 g)(-1) mmHg(-1) in the controls. Vascular reactivity of the mesenteric arteries was not different. These data suggest that coronary conductance can be modified in utero by anaemia (high flow and hypoxaemia) and that the remodelled coronary tree persists to adulthood.
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Affiliation(s)
- L Davis
- Department of Obstetrics and the Heart Research Center, Oregon Health Sciences University, Portland, OR 97239-3098, USA.
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Gervais M, Pons S, Nicoletti A, Cosson C, Giudicelli JF, Richer C. Fluvastatin prevents renal dysfunction and vascular NO deficit in apolipoprotein E-deficient mice. Arterioscler Thromb Vasc Biol 2003; 23:183-9. [PMID: 12588757 DOI: 10.1161/01.atv.0000051404.84665.49] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The objective of this study was to investigate the effects of fluvastatin on atherosclerosis, systemic and regional hemodynamics, and vascular reactivity in apolipoprotein E-deficient (ApoE(-/-)) mice. METHODS AND RESULTS Hemodynamics (fluospheres) and vasomotor responses of thoracic aorta and carotid artery were evaluated in male wild-type (WT) and untreated (ApoE(-/-) Control) or fluvastatin-treated (50 mg/kg per day for 20 weeks) ApoE(-/-) mice, all fed a Western-type diet. Plasma cholesterol and aortic root atherosclerotic lesions (ALs) were greater in ApoE(-/-) Control mice (19+/-1 mmol/L and 63,0176+/-38,785 micro m(2), respectively) than in WT mice (2+/-1 mmol/L and 1+/-1 micro m(2), respectively, P<0.01). Fluvastatin significantly decreased plasma cholesterol (-53%) but failed to limit ALs. Renal blood flow was significantly reduced in ApoE(-/-) Control versus WT (-25%, P<0.05) mice. This reduction was prevented by fluvastatin. Aortic and carotid endothelium-dependent relaxations to acetylcholine were not altered in ApoE(-/-) Control versus WT mice. In carotid arteries from WT mice, these responses were abolished after nitro-L-arginine (L-NA), whereas those from ApoE(-/-) Control were only partially inhibited after L-NA but fully abolished after L-NA+diclofenac. Thus, in carotid arteries from ApoE(-/-) mice, vasodilating prostanoids compensate the deficit in NO availability. Fluvastatin prevented this carotid NO deficit. CONCLUSIONS In ApoE(-/-) mice, chronic fluvastatin treatment preserved renal perfusion and vascular NO availability independently from atherosclerotic lesion prevention.
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Affiliation(s)
- Marianne Gervais
- Département de Pharmacologie, Faculté de Médecine Paris-Sud and INSERM E00.01, Le Kremlin-Bicêtre, France
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Sari R, Nemeth J, Porszasz R, Horvath P, Blasig IE, Ferdinandy P, Nagy I, Lonovics J, Szilvassy Z. Impairment by lovastatin of neural relaxation of the rabbit sphincter of Oddi. Eur J Pharmacol 2001; 432:91-7. [PMID: 11734192 DOI: 10.1016/s0014-2999(01)01454-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We sought whether inhibition of cholesterol biosynthesis by lovastatin influenced the nitrergic relaxation response of the sphincter of Oddi. Rabbit sphincters of Oddi rings were tested for changes in isometric tension in response to field stimulation in the presence of 4 microM guanethidine and 1 microM atropine. Tissue samples were then analyzed for cAMP and cGMP content by radioimmunoassay for nitric oxide concentration by electron spin resonance and for vasoactive intestinal peptide and calcitonin gene-related peptide (CGRP) release by radioimmunoassay. Membrane G(salpha) protein was determined by Western blot analysis. Field stimulation relaxed the preparations with an increase in nitric oxide, cAMP and cGMP concentrations at increased calcitonin gene-related peptide and vasoactive intestinal polypeptide (VIP) release. Preparations from rabbits pre-treated with lovastatin (5 mg/kg/day intragastrically, over 5 days) contracted under the same conditions with an attenuated cGMP-increase at preserved increase in NO content and neuropeptide release. The relaxation was recaptured combining lovastatin with farnesol (1 mg/kg intravenously, twice a day for 5 days). The field stimulation-induced increase in cyclic nucleotides was also restored. Lovastatin decreased membrane G(salpha) protein content, which was re-normalized by farnesol. Farnesol treatment reinstates neurogenic relaxation of the sphincter of Oddi deteriorated by lovastatin possibly by normalizing G-protein coupling.
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Affiliation(s)
- R Sari
- First Department of Medicine, University of Szeged, Koranyi fasor 8, H-6720, Szeged, Hungary
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Pongo E, Balla Z, Mubagwa K, Flameng W, Edes I, Szilvassy Z, Ferdinandy P. Deterioration of the protein kinase C-K(ATP) channel pathway in regulation of coronary flow in hypercholesterolaemic rabbits. Eur J Pharmacol 2001; 418:217-23. [PMID: 11343693 DOI: 10.1016/s0014-2999(01)00954-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We studied the effect of experimental hypercholesterolaemia/atherosclerosis on changes in coronary flow and cardiac function, induced by protein kinase C and ATP-sensitive K(+) (K(ATP)) channel modulators in isolated Langendorff-perfused rabbit hearts. Both phorbol 12-myristate-13-acetate (PMA) and phorbol 12,13-dibutyrate (PDB, 0.1 microM each), activators of protein kinase C, decreased, whereas staurosporine, (0.1 microM), a protein kinase C inhibitor, increased coronary flow and left ventricular dP/dt, an index of ventricular contractility. Glyburide (5-50 microM), a K(ATP) channel inhibitor, blocked the effect of staurosporine. The phorbol esters were without effect in the presence of pinacidil (5 microM), a K(ATP) channel activator. Neither the protein kinase C modulators nor glyburide produced any effect on coronary flow and left ventricular contractility, when the hearts were prepared from animals either maintained on a cholesterol (1.5%)-enriched diet or treated with lovastatin (5 mg/kg/day per os). Treatment with farnesol (1 mg/kg twice a day for 7 days intravenously) restored the reactivity of hearts from either hypercholesterolaemic or lovastatin-treated animals to protein kinase C modulators. We conclude that non-cholesterol mevalonate products are necessary for the functional integrity of the protein kinase C-K(ATP) channel pathway in the rabbit heart.
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Affiliation(s)
- E Pongo
- Centre of Experimental Surgery and Anaesthesiology, Katholieke Universiteit Minderbroedenstraat 17, B-3000, Leuven, Belgium
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Abstract
The beneficial effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) on coronary events have generally been attributed to their hypocholesterolaemic properties. However, as mevalonate and other intermediates of cholesterol synthesis (isoprenoids) are necessary for cell proliferation and other important cell functions, effects other than cholesterol reduction may explain the pharmacological properties of statins. In the present review, we discuss the current knowledge on the nonlipid-related effects of statins, with a special emphasis on their potential benefits in different diseases, such as atherosclerosis and cancer. The mechanism(s) responsible for their favourable properties are also reviewed.
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Affiliation(s)
- S Bellosta
- Institute of Pharmacological Sciences, University of Milan, Italy
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Lindenthal B, von Bergmann K. Urinary excretion and serum concentration of mevalonic acid during acute intake of alcohol. Metabolism 2000; 49:62-6. [PMID: 10647065 DOI: 10.1016/s0026-0495(00)90713-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The influence of 2 different alcoholic beverages containing an equal amount of alcohol (48 g), 1 with mevalonic acid (beer) and 1 without (vodka), on the urinary excretion and serum concentration of mevalonic acid was investigated in 7 healthy subjects. Drinking 1 L of beer at night containing 608 microg/L mevalonic acid more than doubled the urinary excretion of mevalonic acid the following 12 hours, on average from 103 +/- 15 microg/12 h to 211 +/- 17 microg/12 h (P < .001; 18% of the administered dose). Drinking the same amount of alcohol as vodka had no effect, but urinary mevalonic acid output increased slightly the following day (7 AM to 7 PM) after ingestion of both alcoholic beverages. Serum concentrations of mevalonic acid were significantly increased the following morning after ingestion of beer (from 3.22 +/- 0.20 ng/mL to 6.79 +/- 0.58 ng/mL) or vodka (from 3.23 +/- 0.37 ng/mL to 5.36 +/- 0.55 ng/mL, P < .002 for both). An increase in the ratio of lathosterol to cholesterol in serum, another indicator of 3beta-hydroxy-3beta-methylglutaryl coenzyme A reductase activity in the liver, was also observed (+18% and +25%, respectively). After oral administration of [13C2] mevalonic acid at night, 20% +/- 0.7% of the dose was excreted in urine the following 12 hours, and only trace amounts thereafter. No [13C2] mevalonic acid could be detected in serum the following morning. We conclude that the absorption of dietary mevalonic acid and alcohol-induced mevalonic acid synthesis affects the urinary excretion and serum concentration of this cholesterol precursor. Therefore, studies using mevalonic acid as a marker of cholesterol synthesis must be carefully monitored regarding dietary mevalonic acid intake and alcohol consumption.
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Affiliation(s)
- B Lindenthal
- Department of Clinical Pharmacology, University of Bonn, Germany
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Roullet JB, Spaetgens RL, Burlingame T, Feng ZP, Zamponi GW. Modulation of neuronal voltage-gated calcium channels by farnesol. J Biol Chem 1999; 274:25439-46. [PMID: 10464274 DOI: 10.1074/jbc.274.36.25439] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The modulation of presynaptic voltage-dependent calcium channels by classical second messenger molecules such as protein kinase C and G protein betagamma subunits is well established and considered a key factor for the regulation of neurotransmitter release. However, little is known of other endogenous mechanisms that control the activity of these channels. Here, we demonstrate a unique modulation of N-type calcium channels by farnesol, a dephosphorylated intermediate of the mammalian mevalonate pathway. At micromolar concentrations, farnesol acts as a relatively non-discriminatory rapid open channel blocker of all types of high voltage-activated calcium channels, with a mild specificity for L-type channels. However, at 250 nM, farnesol induces an N-type channel-specific hyperpolarizing shift in channel availability that results in approximately 50% inhibition at a typical neuronal resting potential. Additional experiments demonstrated the presence of farnesol in the brain (rodents and humans) at physiologically relevant concentrations (100-800 pmol/g (wet weight)). Altogether, our results indicate that farnesol is a selective, high affinity inhibitor of N-type Ca(2+) channels and raise the possibility that endogenous farnesol and the mevalonate pathway are implicated in neurotransmitter release through regulation of presynaptic voltage-gated Ca(2+) channels.
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Affiliation(s)
- J B Roullet
- Division of Nephrology, Hypertension, and Clinical Pharmacology, Oregon Health Sciences University, Portland, Oregon 97201, USA
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Tesfamariam B, Frohlich BH, Gregg RE. Differential effects of pravastatin, simvastatin, and atorvastatin on Ca2+ release and vascular reactivity. J Cardiovasc Pharmacol 1999; 34:95-101. [PMID: 10413074 DOI: 10.1097/00005344-199907000-00016] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The direct effects of the cholesterol-lowering agents, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG CoA) reductase inhibitors, on vascular smooth muscle responsiveness were examined by incubation of isolated aorta from normocholesterolemic rats with simvastatin, atorvastatin, or pravastatin. The smooth muscle contractions caused by phenylephrine were progressively inhibited with increasing concentrations of simvastatin. Similarly, atorvastatin at the higher concentration caused decreased responses to phenylephrine. In contrast, incubation with pravastatin had no significant effect at all concentrations studied. In Ca2+-free buffer, the transient contraction caused by phenylephrine, which results from intracellular release of Ca2+, also was inhibited by simvastatin and atorvastatin but not by pravastatin. In cultured rat aortic smooth muscle cells loaded with fura-2, increases in intracellular free-Ca2+ concentration ([Ca2+]i) induced by angiotensin II were markedly inhibited in cells incubated with simvastatin and atorvastatin but not pravastatin. The inhibitory effects of simvastatin and atorvastatin were reversed by mevalonate. These findings demonstrate that inhibition of HMG CoA reductase by using simvastatin and atorvastatin, but not pravastatin, has effects on vascular smooth muscle cell responsiveness that involve alteration of Ca2+ homeostasis through a mevalonate-dependent pathway.
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Affiliation(s)
- B Tesfamariam
- Department of Metabolic Diseases, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543, USA
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Gross V, Schneider W, Schunck WH, Mervaala E, Luft FC. Chronic effects of lovastatin and bezafibrate on cortical and medullary hemodynamics in deoxycorticosterone acetate-salt hypertensive mice. J Am Soc Nephrol 1999; 10:1430-9. [PMID: 10405198 DOI: 10.1681/asn.v1071430] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Cholesterol synthesis inhibitors and fibrates both exercise effects that could influence BP and renal function in hypertension. To test this issue, transit-time ultrasound flow probes, implanted optical fibers, and laser-Doppler flowmetry were used for measurements of total and regional renal blood flows in lovastatin (40 mg/kg body wt) and bezafibrate (50 mg/kg body wt) chronically treated deoxycorticosterone acetate (DOCA)-salt hypertensive mice. Total renal blood flow was well autoregulated between 70 and 150 mmHg (approximately 3.5 ml/min per g kidney weight in DOCA-salt mice). Both lovastatin and bezafibrate increased renal blood flow to a range between 4.7 and 5.5 ml/min per g kidney weight. In the renal perfusion pressure ranges investigated, renal vascular resistance increased in lovastin- and bezafibrate-treated DOCA-salt mice, but not as steeply as in vehicle-treated DOCA-salt mice. During a stepwise increase in renal perfusion pressure in lovastatin-treated DOCA-salt mice, medullary blood flow increased up to 130% of baseline values, which was not seen in vehicle- or bezafibrate-treated mice. After extracellular volume expansion with 1% saline, 1 ml over 1 min, total renal blood flow was also higher in lovastatin- or bezafibrate-treated DOCA-salt mice, whereas medullary blood flow increased more steeply in lovastatin-, compared with bezafibrate- or vehicle-treated mice. Systemic BP was significantly decreased in lovastatin-treated DOCA-salt mice compared with vehicle-treated mice. Lovastatin prevented histologic evidence for hemostasis in the medullary circulation of DOCA-salt mice. The results suggest that both lovastatin and bezafibrate diminished DOCA-salt-induced reductions in total renal blood flow. Lovastatin also abolished the perturbed medullary blood flow reactions to increased perfusion pressure or to volume expansion. Finally, lovastatin decreased systemic BP in DOCA-salt mice. These data suggest that cholesterol synthesis inhibition or fibrate treatment improve disturbed renal function in a mouse model of salt-dependent hypertension.
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Affiliation(s)
- V Gross
- Franz Volhard Clinic and Max Delbrück Center for Molecular Medicine, Medical Faculty of the Charité, Humboldt University of Berlin, Germany
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Luft UC, Bychkov R, Gollasch M, Gross V, Roullet JB, McCarron DA, Ried C, Hofmann F, Yagil Y, Yagil C, Haller H, Luft FC. Farnesol blocks the L-type Ca2+ channel by targeting the alpha 1C subunit. Arterioscler Thromb Vasc Biol 1999; 19:959-66. [PMID: 10195923 DOI: 10.1161/01.atv.19.4.959] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We recently demonstrated that farnesol, a 15-carbon isoprenoid, blocks L-type Ca2+ channels in vascular smooth muscle cells. To elucidate farnesol's mechanism of action, we performed whole-cell and perforated-patch clamp experiments in rat aortic A7r5 cells and in Chinese hamster ovary (CHO) C9 cells expressing smooth muscle Ca2+ channel alpha 1C subunits. Farnesol dose-dependently and voltage-independently inhibited Ba2+ currents in both A7r5 and CHOC9 cells, with similar half-maximal inhibitions at 2.6 and 4.3 micromol/L, [corrected] respectively (P=NS). In both cell lines, current inhibition by farnesol was prominent over the whole voltage range without changes in the current-voltage relationship peaks. Neither intracellular infusion of the stable GDP analogue guanosine-5'-O-(2-thiodiphosphate) (100 micromol/L) [corrected] via the patch pipette nor strong conditioning membrane depolarization prevented the inhibitory effect of farnesol, which indicates G protein-independent inhibition of Ca2+ channels. In an analysis of the steady-state inactivation curve for voltage dependence, farnesol induced a significant, negative shift ( approximately 10 mV) of the potential causing 50% channel inactivation in both cell lines (P<0. 001). In contrast, the steepness factor characterizing the voltage sensitivity of the channels was unaffected. Unlike pharmacological Ca2+ channel blockers, farnesol blocked Ca2+ currents in the resting state: initial block was 63+/-8% in A7r5 cells and 50+/-9% in CHOC9 cells at a holding potential of -80 mV. We then gave 500 mg/kg body weight farnesol by gavage to Sabra hypertensive and normotensive rats and found that farnesol reduced blood pressure significantly in the hypertensive strain for at least 48 hours. We conclude that farnesol may represent an endogenous smooth muscle L-type Ca2+ channel antagonist. Because farnesol is active in cells expressing only the pore-forming alpha1 subunit, the data further suggest that this subunit represents the molecular target for farnesol binding and principal action. Finally, farnesol has a blood pressure-lowering action that may be relevant in vivo.
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Affiliation(s)
- U C Luft
- Franz Volhard Clinic and Max Delbrück Center for Molecular Medicine, Virchow Klinikum-Charité, Humboldt University of Berlin, Berlin, Germany.
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18
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De Lima JJ, Xue H, Coburn L, Andoh TF, McCarron DA, Bennett WM, Roullet JB. Effects of FK506 in rat and human resistance arteries. Kidney Int 1999; 55:1518-27. [PMID: 10201018 DOI: 10.1046/j.1523-1755.1999.00366.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND FK506 is widely used in organ transplantation and causes hypertension. However, little is known about the impact of the drug on the cardiovascular system. METHODS We therefore investigated the effect of FK506 on resistance artery and blood pressure responsiveness to vasoconstrictors and vasodilators. Studies were conducted in vitro using human and murine resistance artery, ex vivo in resistance artery isolated from rats treated with FK506 (6 mg/kg/day), and in vivo in conscious, treated animals. RESULTS In vitro exposure (24 hr) of human and rat resistance artery to FK506 (1000 ng/ml) increased the sensitivity to norepinephrine (NE) and impaired the response to acetylcholine (Ach) and sodium nitroprusside (SNp). In contrast, arteries isolated from rats given FK506 for eight days showed a reduced sensitivity to NE (P < 0.05) and a normal endothelium-dependent relaxation. Their incubation with L-arginine caused a significant reduction in Ach sensitivity in the FK506 group (P < 0.05) but not in controls, suggesting enhancement of nitric oxide production by the drug. The sensitivity to SNp was reduced, as in the in vitro experiments (P < 0.05). Rats given FK506 for eight days presented blood pressure similar to that in controls but also presented signs of a compensatory response to excess vasodilation: tachycardia (P < 0.01), reduced blood pressure sensitivity to NE and Ach, blunted heart rate response to both agonists, and exaggerated hypotension at high doses of Ach. After 21 days of treatment, blood pressure remained similar to that in controls, but resistance artery showed further functional deterioration, with significant impairment of the maximum responses to Ach and to SNp. CONCLUSION FK506 presents significant vascular toxicity affecting mainly smooth muscle relaxation and alters vascular hemodynamics. The data suggest that similar cardiovascular changes may occur in transplant patients and represent the forerunner of hypertension often seen with more prolonged use of the drug.
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Affiliation(s)
- J J De Lima
- Department of Nephrology, Hypertension, and Clinical Pharmacology, Oregon Health Sciences University, Portland, USA
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19
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Szilvassy Z, Sari R, Nemeth J, Nagy I, Csati S, Lonovics J. Improvement of nitrergic relaxation by farnesol of the sphincter of Oddi from hypercholesterolaemic rabbits. Eur J Pharmacol 1998; 353:75-8. [PMID: 9721042 DOI: 10.1016/s0014-2999(98)00449-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Field stimulation relaxed the rabbit sphincter of Oddi muscle rings after incubation with atropine (1 microM) and guanethidine (4 microM) with a threefold increase in tissue cyclic cGMP content, a response previously shown to be essentially nitrergic. Preparations from hypercholesterolaemic rabbits (1.5% dietary cholesterol load over 8 weeks increasing serum total cholesterol from pre-diet 1.4+/-0.3 to 22.6+/-3.8 mmol/l) exhibited contractions with no change in cyclic GMP content under the same conditions. The nitrergic relaxation was recaptured with a twofold increase in tissue cyclic GMP content in preparations from hypercholesterolaemic rabbits undergone a treatment with 30 microM/kg farnesol i.v. twice a day over the last 3 days of the dietary period. We conclude that farnesol treatment restores nitrergic relaxation of the sphincter of Oddi in hypercholesterolaemia.
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Affiliation(s)
- Z Szilvassy
- 1st Department of Medicine, Albert Szent-Gyorgyi Medical University Szeged, Hungary.
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Roullet JB, Luft UC, Xue H, Chapman J, Bychkov R, Roullet CM, Luft FC, Haller H, McCarron DA. Farnesol inhibits L-type Ca2+ channels in vascular smooth muscle cells. J Biol Chem 1997; 272:32240-6. [PMID: 9405427 DOI: 10.1074/jbc.272.51.32240] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Earlier experiments with animal and human arteries have shown that farnesol, a natural 15-carbon (C15) isoprenoid, is an inhibitor of vasoconstriction (Roullet, J.-B., Xue, H., Chapman, J., McDougal, P., Roullet, C. M., and McCarron, D. A. (1996) J. Clin. Invest. 97, 2384-2390). We report here that farnesol reduced KCl- and norepinephrine-dependent cytosolic Ca2+ transients in fura-2-loaded intact arteries. An effect on Ca2+ signaling was also observed in cultured aortic smooth muscle cells (A10 cells). In these cells, farnesol reduced KCl-induced [Ca2+]i transients and mimicked the inhibitory effect of Ca2+-free medium on the [Ca2+]i response to both 12,13-phorbol myristate acetate, a protein kinase C activator, and thapsigargin, a specific endoplasmic reticulum ATPase inhibitor. Perforated patch-clamp experiments further showed in two vascular smooth muscle cell lines (A10 and A7r5), a reversible, dose-dependent inhibitory effect of farnesol on L-type Ca2+ currents (IC50 = 2.2 microM). Shorter (C10, geraniol) and longer (C20, geranylgeraniol) isoprenols were inactive. L-type Ca2+ channel blockade also occurred under tight (gigaohm) seal configuration using cell-attached, single-channel analysis, thus suggesting a possible action of farnesol from within the intracellular space. We finally demonstrated that farnesol did not affect Ca2+-sensitive pathways implicated in smooth muscle contraction, as tested with alpha-toxin permeabilized arteries. Altogether, our results indicate that farnesol is an inhibitor of vascular smooth muscle Ca2+ signaling with plasma membrane Ca2+ channel blocker properties. The data have implications for the endogenous and pharmacological regulation of vascular tone by farnesol or farnesol analogues.
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Affiliation(s)
- J B Roullet
- Department of Nephrology, Hypertension and Clinical Pharmacology, Oregon Sciences Health University, Portland, Oregon 97201, USA.
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Glazer AA, Inman SR, Stowe NT, Novick AC. Renal microcirculatory effects of lovastatin in a rat model of reduced renal mass. Urology 1997; 50:812-7. [PMID: 9372901 DOI: 10.1016/s0090-4295(97)00338-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES Patients with reduced renal mass are at increased risk of developing renal failure. A remnant kidney model has been used to study the hemodynamic and structural changes that occur. We recently reported that the lipid-lowering agent lovastatin preserves renal function in this model. The purpose of the present study was to determine the specific effects of lovastation on the renal microcirculation of rats with reduced renal mass. METHODS We used the rat hydronephrotic kidney preparation with a 5/6 partial nephrectomy. This model allows direct visualization of preglomerular and postglomerular vessels using videomicroscopy. The diameters and vascular responses to acetylcholine and angiotensin II of the interlobular, afferent, and efferent vessels were determined in two groups of animals with renal mass reduction: 15 rats with no lovastatin treatment and 18 rats treated with oral lovastatin (15 mg/kg body weight/day) for 2 weeks. RESULTS In the lovastatin-treated rats, the baseline efferent vessel diameter was smaller by 21% (P < 0.05), but the interlobular and afferent vessel baseline diameters were not different from those in the untreated rats. Serum creatinine levels were lower in the treated rats (1.5 +/- 0.1 versus 2.0 +/- 0.2 mg/dL, P < 0.05), but serum lipids were not different. In the lovastatin-treated rats, vascular reactivity to acetylcholine was enhanced in the afferent and decreased in the efferent vessels. CONCLUSIONS In this renal ablation model, lovastatin preserved renal function as measured by serum creatinine without lowering plasma lipid levels. Lovastatin treatment resulted in smaller efferent vessel diameters. Lovastatin also increased the vasodilatory response to acetylcholine in the afferent vessels. Together, these preglomerular and postglomerular changes would increase the single-nephron glomerular filtration rate. The renal protective effect of lovastatin may be due to these vasoactive effects on the renal microcirculation.
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Affiliation(s)
- A A Glazer
- Department of Urology, Cleveland Clinic Foundation, OH 44195, USA
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Scoppola A, De Paolis P, Menzinger G, Lala A, Di Giulio S. Plasma mevalonate concentrations in uremic patients. Kidney Int 1997; 51:908-12. [PMID: 9067929 DOI: 10.1038/ki.1997.128] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Mevalonic acid (mevalonate or MVA), is an obligate precursor in the biosynthetic pathway of cholesterol. It is partially metabolized by the kidneys and its plasma concentrations are an index of endogenous cholesterol synthesis. The aim of the present study was to evaluate plasma MVA concentrations in uremic patients with different degrees of chronic renal failure (CRF; group A), and the effects of a single hemodialysis treatment on plasma MVA in a group of patients with end-stage renal disease (ESRD; group B). CRF patients exhibited a higher mean basal mevalonate concentration (13.3 +/- 6.5 ng/ml) than control subjects (4.68 +/- 1.32 ng/ml; P < 0.001). A statistically significant direct correlation was evident in CRF patients between mevalonate and creatinine plasma levels (r = 0.86; P < 0.001). A single hemodialysis treatment was associated with a significant reduction of plasma mevalonate concentrations four hours after the hemodialysis session (-57%; P < 0.001) and an increase up to the basal values 24 hours after the end of the treatment. In conclusion, our results demonstrated: (i) higher plasma MVA concentrations in patients with decreased renal function; (ii) a direct relationship between plasma MVA levels and the degree of kidney failure as expressed by creatinine plasma concentrations; and (iii) a clear cut reduction of elevated plasma MVA levels after a single hemodialysis treatment.
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Affiliation(s)
- A Scoppola
- Cattedra di Endocrinologia Università di Roma Tor Vergata, Italy
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Roullet JB, Xue H, Chapman J, McDougal P, Roullet CM, McCarron DA. Farnesyl analogues inhibit vasoconstriction in animal and human arteries. J Clin Invest 1996; 97:2384-90. [PMID: 8636420 PMCID: PMC507320 DOI: 10.1172/jci118682] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Recent studies have suggested that nonsterol, mevalonate-derived metabolites are implicated in the control of vascular tone and blood pressure. Because of the metabolic importance of farnesyl pyrophosphate, a 15-carbon (C15) intermediate of the cholesterol pathway, the vasoactive properties of the farnesyl motif were investigated. Two farnesyl analogues were used: farnesol, the natural dephosphorylated form of farnesyl pyrophosphate, and N-acetyl-S-trans,trans-farnesyl-L-cysteine (AFC), a synthetic mimic of the carboxyl terminus of farnesylated proteins. Both compounds inhibited NE-induced vasoconstriction in rat aortic rings at micromolar concentration. Their action was rapid, dose dependent, and reversible. Shorter (C10) and longer (C20) isoprenols as well as N-acetyl-S-geranyl-L-cysteine (C10) did not inhibit the response to NE. In contrast, N-acetyl-S-geranylgeranyl-L-cysteine (C20), exhibited vasoactive properties similar to AFC. It was further demonstrated that AFC and farnesol inhibited KCl and NaF-induced contractions, suggesting a complex action on Ca2+ channels and G protein-dependent pathways. Finally, the effect of farnesol and AFC on the NE response was reproduced in human resistance arteries. In conclusion, mevalonate-derived farnesyl analogues are potent inhibitors of vasoconstriction. The study suggests that farnesyl cellular availability is an important determinant of vascular tone in animals and humans, and provides a basis for exploring farnesyl metabolism in humans with compromised vascular function as well as for using farnesyl analogues as regulators of arterial tone in vivo.
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Affiliation(s)
- J B Roullet
- Department of Nephrology, Hypertension and Clinical Pharmacology, Oregon Health Sciences University, Portland 97201, USA
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