We studied the activation of β2-adrenergic receptor(β2AR) by norepinephrine, epinephrine and isoprote- renol using docking and molecular dynamics(MD) simulation. The simulation was done on the assumption that β...We studied the activation of β2-adrenergic receptor(β2AR) by norepinephrine, epinephrine and isoprote- renol using docking and molecular dynamics(MD) simulation. The simulation was done on the assumption that β2AR was surrounded with explicit water and infinite lipid bilayer membrane at body temperature. So the result should be close to that under the physiological conditions. We calculated the structure of binding sites in β2AR for the three ac- tivators. We also simulated the change of the conformation ofβ2AR in the transmembrane regions(TMs), in the mo- lecular switches, and in the conserved DRY(Aspartic acid, Arginine and Tyrosine) motif. This study provides detailed information concerning the structure ofβ2AR during activation process.展开更多
Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 + ([Ca^2+ ]i) in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending co...Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 + ([Ca^2+ ]i) in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending coronary artery of rat hearts. Rats in the control group were sham-operated. Cardiomyocytes were dissociated at two, four, eight weeks after myocardial infarction (MI) and [Ca^2+]i was measured via fura-2 fluorescence. The response of cardiomyocytes to isoproterenol in presence or absence of betal-adrenergic antagonist atenolol, beta2-adrenergic antagonist ICI118, 551 or non-selective β1, 2- adrenergic antagonists propranolol was examined. Results The followings were found that ICI 118, 551 had no significant effects on the rise of [Ca^2+]i induced by isoproterenol in normal ventricular myocytes (P 〉 0.05), ICI118, 551 only significantly attenuated the rise of [Ca^2+]i induced by isoproterenol at four weeks and eight weeks after MI (24.5%±5.7% vs 57.8% ± 13.2%, P〈 0.01; 12.2%±7.9% vs 44.6%±11.3%, P〈 0.01). Atenolol had suppressive effects only in the control group and the post-MI group of two weeks (P 〈 0.05), and propranolol had suppressive effects in the control and all the three post-MI groups (P 〈 0.01). Conclusions Beta2-adrenergic antagonist ICI118, 551 may exert negative effects on Ca^2+ overload initiated by sympathetic stimulation after MI.展开更多
Background Chronic obstructive pulmonary disease (COPD) is a heterogeneous and complex disease of which the pathogenesis remains largely unknown. Many factors could influence COPD development and progression. One of...Background Chronic obstructive pulmonary disease (COPD) is a heterogeneous and complex disease of which the pathogenesis remains largely unknown. Many factors could influence COPD development and progression. One of them is the genetic risk factor. A severe hereditary deficiency of alpha-1 antitrypsin is the best genetic proof. Four single nucleotide polymorphisms (SNPs) of beta2-adrenergic receptor (β2AR) result in single amino acid substitution. Two loci had been extensively studied and found that they could change the function of β2AR. Two SNPs consist of substitutions of glycine for arginine at amino acid position 16, glutamic acid for glutamine at position 27. Many studies proved that polymorphisms at position 16 and 27 altered the lung function of COPD patients or the patient's susceptibility to the development of COPD. However, there was no exclusive conclusion. Therefore, a meta analysis was done to investigate the effect of polymorphisms in the 62-adrenergic receptor (ADRB2) gene on the risk of COPD and lung function. Methods Comprehensive searches of MEDLINE, Embase, Ovid, HighWire, Cochrane Library, and Chinese databases (CBMdisc, VIP, CNKI, and Wanfang data) from January 1980 to September 2011 were performed, using the keywords: COPD OR chronic obstructive pulmonary disease AND adrenoreceptor OR adrenergic receptor AND polymorphism OR mutation OR variation. Case-control research or cross sectional studies in which diagnosis of COPD met the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines; all the studies reported the ADRB2 genotype at position 16 or 27. Outcomes measured were genotype frequency and forced expiratory volume in the first second (FEV1%) in both the case and control. Results Twelve case-control studies and eight cross-sectional studies were included. Compared to the control (n= 1225), neither Gly/Gly (n=527) nor Arg/Arg (n=422) homozygotes at position 16 demonstrated increased susceptibility to COPD, with odds ratios (ORs) of 0.95 (95% CI (0.68, 1.31), z=0.33, P=0.740) and 0.82 (95% CI (0.52, 1.28), z=0.88, P=0.381), respectively. Similar results were obtained for position 27, with ORs of 0.97 (95% CI (0.77, 1.23), z=0.21, P=0.833) for Glu/Glu homozygotes (n=357) and 0.82 (95% CI (0.53, 1.29), z=0.85, P=0.393) for Gin/Gin homozygotes (n=704) (control=1183). In patients with COPD, Arg/Arg homozygotes (n=41) had a similar FEV1% compared with Gly/Gly homozygotes (n=102) (standardized mean difference (SMD)=0.88, 95% CI (-0.85, 2.62), z=1.00, P=0.319). The genotype distribution was different between Caucasian and Asian populations (all P 〈0.05 except the genotype Arg/Gly) for both position 16 and 27. Conclusions Polymorphisms of ADRB2 at positions 16 and 27 did not change the risk of COPD nor affect lung function or disease severity. The genotype distribution for these polymorphisms was different between Caucasian and Asian populations.展开更多
Adipose tissue is a promising target for treating obesity and metabolic diseases.However,pharmacological agents usually fail to effectively engage adipocytes due to their extraordinarily large size and insufficient va...Adipose tissue is a promising target for treating obesity and metabolic diseases.However,pharmacological agents usually fail to effectively engage adipocytes due to their extraordinarily large size and insufficient vascularization,especially in obese subjects.We have previously shown that during cold exposure,connexin43(Cx43)gap junctions are induced and activated to connect neighboring adipocytes to share limited sympathetic neuronal input amongst multiple cells.We reason the same mechanism may be leveraged to improve the efficacy of various pharmacological agents that target adipose tissue.Using an adipose tissue-specific Cx43 overexpression mouse model,we demonstrate effectiveness in connecting adipocytes to augment metabolic efficacy of theβ_(3)-adrenergic receptor agonist Mirabegron and FGF21.Additionally,combing those molecules with the Cx43 gap junction channel activator danegaptide shows a similar enhanced efficacy.In light of these findings,we propose a model in which connecting adipocytes via Cx43 gap junction channels primes adipose tissue to pharmacological agents designed to engage it.Thus,Cx43 gap junction activators hold great potential for combination with additional agents targeting adipose tissue.展开更多
基金Supported by the Young and Middle-Aged Scientists Research Awards Foundation of Shangdong Province,China(No.BS2011SW002)the Research Foundation for Advanced Talents of Ludong University,China(No.LY2011017)
文摘We studied the activation of β2-adrenergic receptor(β2AR) by norepinephrine, epinephrine and isoprote- renol using docking and molecular dynamics(MD) simulation. The simulation was done on the assumption that β2AR was surrounded with explicit water and infinite lipid bilayer membrane at body temperature. So the result should be close to that under the physiological conditions. We calculated the structure of binding sites in β2AR for the three ac- tivators. We also simulated the change of the conformation ofβ2AR in the transmembrane regions(TMs), in the mo- lecular switches, and in the conserved DRY(Aspartic acid, Arginine and Tyrosine) motif. This study provides detailed information concerning the structure ofβ2AR during activation process.
文摘Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 + ([Ca^2+ ]i) in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending coronary artery of rat hearts. Rats in the control group were sham-operated. Cardiomyocytes were dissociated at two, four, eight weeks after myocardial infarction (MI) and [Ca^2+]i was measured via fura-2 fluorescence. The response of cardiomyocytes to isoproterenol in presence or absence of betal-adrenergic antagonist atenolol, beta2-adrenergic antagonist ICI118, 551 or non-selective β1, 2- adrenergic antagonists propranolol was examined. Results The followings were found that ICI 118, 551 had no significant effects on the rise of [Ca^2+]i induced by isoproterenol in normal ventricular myocytes (P 〉 0.05), ICI118, 551 only significantly attenuated the rise of [Ca^2+]i induced by isoproterenol at four weeks and eight weeks after MI (24.5%±5.7% vs 57.8% ± 13.2%, P〈 0.01; 12.2%±7.9% vs 44.6%±11.3%, P〈 0.01). Atenolol had suppressive effects only in the control group and the post-MI group of two weeks (P 〈 0.05), and propranolol had suppressive effects in the control and all the three post-MI groups (P 〈 0.01). Conclusions Beta2-adrenergic antagonist ICI118, 551 may exert negative effects on Ca^2+ overload initiated by sympathetic stimulation after MI.
基金This study was supported by the grants from the National Natural Science Foundation of China (30770939) and Doctoral Fund of Ministry of Education (20090001110093).
文摘Background Chronic obstructive pulmonary disease (COPD) is a heterogeneous and complex disease of which the pathogenesis remains largely unknown. Many factors could influence COPD development and progression. One of them is the genetic risk factor. A severe hereditary deficiency of alpha-1 antitrypsin is the best genetic proof. Four single nucleotide polymorphisms (SNPs) of beta2-adrenergic receptor (β2AR) result in single amino acid substitution. Two loci had been extensively studied and found that they could change the function of β2AR. Two SNPs consist of substitutions of glycine for arginine at amino acid position 16, glutamic acid for glutamine at position 27. Many studies proved that polymorphisms at position 16 and 27 altered the lung function of COPD patients or the patient's susceptibility to the development of COPD. However, there was no exclusive conclusion. Therefore, a meta analysis was done to investigate the effect of polymorphisms in the 62-adrenergic receptor (ADRB2) gene on the risk of COPD and lung function. Methods Comprehensive searches of MEDLINE, Embase, Ovid, HighWire, Cochrane Library, and Chinese databases (CBMdisc, VIP, CNKI, and Wanfang data) from January 1980 to September 2011 were performed, using the keywords: COPD OR chronic obstructive pulmonary disease AND adrenoreceptor OR adrenergic receptor AND polymorphism OR mutation OR variation. Case-control research or cross sectional studies in which diagnosis of COPD met the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines; all the studies reported the ADRB2 genotype at position 16 or 27. Outcomes measured were genotype frequency and forced expiratory volume in the first second (FEV1%) in both the case and control. Results Twelve case-control studies and eight cross-sectional studies were included. Compared to the control (n= 1225), neither Gly/Gly (n=527) nor Arg/Arg (n=422) homozygotes at position 16 demonstrated increased susceptibility to COPD, with odds ratios (ORs) of 0.95 (95% CI (0.68, 1.31), z=0.33, P=0.740) and 0.82 (95% CI (0.52, 1.28), z=0.88, P=0.381), respectively. Similar results were obtained for position 27, with ORs of 0.97 (95% CI (0.77, 1.23), z=0.21, P=0.833) for Glu/Glu homozygotes (n=357) and 0.82 (95% CI (0.53, 1.29), z=0.85, P=0.393) for Gin/Gin homozygotes (n=704) (control=1183). In patients with COPD, Arg/Arg homozygotes (n=41) had a similar FEV1% compared with Gly/Gly homozygotes (n=102) (standardized mean difference (SMD)=0.88, 95% CI (-0.85, 2.62), z=1.00, P=0.319). The genotype distribution was different between Caucasian and Asian populations (all P 〈0.05 except the genotype Arg/Gly) for both position 16 and 27. Conclusions Polymorphisms of ADRB2 at positions 16 and 27 did not change the risk of COPD nor affect lung function or disease severity. The genotype distribution for these polymorphisms was different between Caucasian and Asian populations.
基金supported in part by a research grant from Novo Nordsik(USA,to Philipp E.Scherer)by NIH Grants(USA)R01-DK55758,R01-DK099110,R01-DK127274,R01DK131537 and P01-AG051459 to Philipp E.Scherer,NIH Grant R00-DK114498+4 种基金NIH Grant K99-AG068239 to Shangang ZhaoNIH Grant K01-DK125447 to Yu A.AnNIH grants R01 DK119169 and P01 DK119130-5830 to Kevin W.WilliamsUSDA ARS(cooperative agreement 309251000-062)to Yi ZhuAHA Career Development Award 855170(USA)to Qingzhang Zhu。
文摘Adipose tissue is a promising target for treating obesity and metabolic diseases.However,pharmacological agents usually fail to effectively engage adipocytes due to their extraordinarily large size and insufficient vascularization,especially in obese subjects.We have previously shown that during cold exposure,connexin43(Cx43)gap junctions are induced and activated to connect neighboring adipocytes to share limited sympathetic neuronal input amongst multiple cells.We reason the same mechanism may be leveraged to improve the efficacy of various pharmacological agents that target adipose tissue.Using an adipose tissue-specific Cx43 overexpression mouse model,we demonstrate effectiveness in connecting adipocytes to augment metabolic efficacy of theβ_(3)-adrenergic receptor agonist Mirabegron and FGF21.Additionally,combing those molecules with the Cx43 gap junction channel activator danegaptide shows a similar enhanced efficacy.In light of these findings,we propose a model in which connecting adipocytes via Cx43 gap junction channels primes adipose tissue to pharmacological agents designed to engage it.Thus,Cx43 gap junction activators hold great potential for combination with additional agents targeting adipose tissue.