β3-adrenoceptor (β3-AR) has been shown to promote myocardial apoptosis. However, the exact physiological role and importance of this receptor in the human myocardium, and its underlying mode of action, have not been fully elucidated. The present study aimed to determine the effects of β3-AR on the promotion of myocardial apoptosis and on norepinephrine (NE) injury. We analyzed NE-induced cardiomyocyte (CM) apoptosis by using a TUNEL and an annexin V/propidium iodide apoptosis assay. Furthermore, we investigated the NE-induced expression of the apoptosis marker genes Akt and p38MAPK, their phosphorylated counterparts p-Akt and p-p38MAPK, caspase-3, Bcl-2, and Bax. In addition, we determined the effect of a 48-h treatment with a β3-AR agonist and antagonist on expression of these marker genes. β3-AR overexpression was found to increase CM apoptosis, accompanied by an increased expression of caspase-3, bax/bcl-2, and p-p38MAPK. In contrast, the β3-blocker reduced apoptosis of CMs and the associated elevated Akt expression. We identified a novel and potent anti-apoptosis mechanism via the PI3K/Akt pathway and a pro-apoptosis pathway mediated by p38MAPK.
Adrenergic Agonists ; pharmacology ; Adrenergic Antagonists ; pharmacology ; Animals ; Apoptosis ; Cells, Cultured ; Myocytes, Cardiac ; drug effects ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenergic, beta-3 ; genetics ; metabolism ; Signal Transduction ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo assess the association of T190C polymorphism of β3 adrenergic receptor gene (β3-AR) with chronic heart failure (CHF), and to evaluate the effect of this polymorphism on clinical response to β-AR blockade among patients with CHF.

METHODSThree hundred and thirty patients with stable CHF receiving basic therapy for heart failure were included. Before initiation and 5 months after the maximal tolerated dose of carvedilol was reached, all indices including heart rate (HR), blood pressure (BP), left atrial diameter (LAD), left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular ejection fraction (LVEF), brain natriuretic peptide (BNP) level, 6 min walk distance were measured and compared with the indices of those with a T190C genotype. Distribution of the T190C polymorphisms in the control group and CHF group was compared.

RESULTSThe frequencies of T190C genotypes of the &beta;3-AR gene have fit with the Hardy-Weinberg equilibrium. No significant difference was found between the frequencies of T190C alleles and genotypes between the two groups (P > 0.05). Compared with CC-homozygotes, TT-homozygous patients showed substantially greater improvement in LVEF and BNP (all P < 0.01).

CONCLUSIONNo difference has been detected in the prevalence of the three genotypes between healthy and CHF subjects. The T190C variation of the &beta;3-AR gene was not associated with increased risk for CHF. CHF patients with a T allele have greater response to carvedilol than those carrying a C allele in ethnic Han Chinese.

Adult ; Carbazoles ; therapeutic use ; Chronic Disease ; Female ; Heart Failure ; drug therapy ; genetics ; physiopathology ; Humans ; Male ; Middle Aged ; Polymorphism, Genetic ; Propanolamines ; therapeutic use ; Receptors, Adrenergic, beta-3 ; genetics ; Ventricular Function, Left

OBJECTIVETo investigate the antiobesity effect of Jueming Prescription (JMP), a Chinese herbal medicine formula, and its influence on mRNA expressions of beta3 adrenergic receptor (beta3-AR) and uncoupling protein-2 (UCP-2) in adipose tissue of diet-induced obese rats.

METHODSFifty male Sprague-Dawley rats were randomly divided into the normal control group (n =8) that was on a standard chow diet, and the obese model group (n =42) that was on a diet of high fat chow. Two weeks after the high fat diet, 29 obese rats in the obese model group were further randomly divided into 3 groups: the untreated obese model group (n =9), the metformin group (n =10, metformin 300 mg kg⁻¹ day)⁻¹, and the JMP group (n =10, JMP 4 g kg⁻¹ day⁻¹). After 8-week treatment, body weight, wet weight of visceral fat, and percentage of body fat (PBF) were measured. The levels of fasting blood glucose, serum lipids, and insulin were assessed, and insulin sensitivity index (ISI) was calculated. The adipose tissue section was stained with hematoxylin-Eosin, and the cellular diameter and quantity of adipocytes were evaluated by light microscopy. The mRNA expressions of beta3-AR and UCP-2 from the peri-renal fat tissue were determined by real-time reverse transcription polymerase chain reaction (RT-PCR).

RESULTSCompared with the obese model group, treatment with JMP resulted in significantly lower body weight, wet weight of visceral fat, PBF, and diameter of adipocytes, and significantly higher level of high-density lipoprotein cholesterol, ISI (all P<0.01), JMP increased the mRNA expressions of beta3-AR and UCP-2 from perirenal fat tissue (P <0.05, P<0.01).

CONCLUSIONSJMP could reduce body weight and adipocyte size; and the effect was associated with the up-regulation of beta3-AR and UCP-2 expressions in the adipose tissue and improvement of insulin sensitivity.

Adipocytes ; drug effects ; metabolism ; pathology ; Adiposity ; drug effects ; Animals ; Blood Glucose ; metabolism ; Body Weight ; drug effects ; Cell Size ; drug effects ; Diet, High-Fat ; Drugs, Chinese Herbal ; pharmacology ; Epididymis ; drug effects ; pathology ; Fasting ; blood ; Gene Expression Regulation ; drug effects ; Insulin ; blood ; Intra-Abdominal Fat ; drug effects ; metabolism ; pathology ; Ion Channels ; genetics ; metabolism ; Lipids ; blood ; Male ; Mitochondrial Proteins ; genetics ; metabolism ; Obesity ; blood ; genetics ; pathology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenergic, beta-3 ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Uncoupling Protein 2 ; Weight Loss ; drug effects

BACKGROUNDIt has been shown that the &beta;3-adrenergic receptor (&beta;3-AR) gene Trp64Arg mutation was closely related to obesity and insulin resistance, and may be related to the prevalence of metabolic syndrome (MS). The aim of this study was to investigate the relationship between the &beta;3-AR gene mutation and the prevalence of MS.

METHODSA seven-year follow-up study was initiated in 2000, with 496 samples of simplex obese subjects (body mass index ≥ 25 kg/m(2)) and 248 normal-weight subjects. According to the &beta;3-AR genotypes, the subjects were classified as Trp64 homozygote group and Arg64 carrier group and after 7 years the prevalence of MS was determined.

RESULTSAccording to the baseline profile, there were no significant differences in the adiposity, blood pressure, lipid profile, fasting plasma glucose and fasting insulin between Trp64 homozygote group and Arg64 carrier group either in obesity or normal-weight subjects. The results of follow-up study indicated that in obese men the prevalence rate of MS was much higher in Arg64 carrier group than that in Trp64 homozygote group (54.76% vs. 40.85%, P < 0.05), but there was no statistical difference in women of the above groups. The prevalence rate of MS in obese men of both Trp64 homozygote group and Arg64 carrier obese group were obviously higher than that in women of the above groups (40.85% vs. 18.27% and 54.76% vs 21.28%, all P < 0.005). Differences were not statistically significant in the prevalence of MS for normal weight Trp64 homozygote group and normal weight Arg64 carrier group, either between men, between women, or between men and women. Comparison of populations indicated that no matter with the &beta;3-AR gene mutation or not, the prevalence of MS in obese subjects was significantly higher than normal weight subjects (χ(2) = 28.240 and χ(2) = 15.586, all P < 0.005). Logistic analysis showed that the mutation of &beta;3-AR gene was associated with the prevalence of MS in men.

CONCLUSIONThe mutation of &beta;3-AR gene is the independent risk factor for the prevalence of MS in men.

Adult ; Body Mass Index ; Female ; Follow-Up Studies ; Humans ; Insulin Resistance ; Logistic Models ; Male ; Metabolic Syndrome ; etiology ; genetics ; Middle Aged ; Mutation ; Receptors, Adrenergic, beta-3 ; genetics

AIMTo provide further evidence for the synthesis of catecholamines (CAs) in lymphocytes and to investigate the effect of the endogenous CAs synthesized by lymphocytes on function of the lymphocytes themselves and the receptor mechanisms involved in the effect.

METHODSRT-PCR was performed to detect the expression of TH mRNA in the lymphocytes from the mesenteric lymph nodes of rats. Different concentrations of pargyline, an inhibitor of monoamine oxydase, and antagonists of alpha1-, alpha2-, beta1-, and beta2-adrenergic receptor (AR) were added to the lymphocyte cultures, and then proliferative response of the lymphocytes to mitogen concanavalin A (Con A) were measured via methyl-thiazole-tetrazolium (MTT) assay.

RESULTSThe lymphocytes could express TH mRNA, and the expression of TH mRNA was significantly higher in the Con A-activated lymphocytes than in the resting ones. The treatment of pargyline of 10(-6) and 10(-5) mol/L (not 10(-7) mol/L) notably attenuated Con A-induced lymphocyte proliferation. Beta2-AR antagonist ICI118551 (10(-7) and 10(-6) mol/L) completely blocked, but alpha1-AR antagonist corynanthine and alpha2-AR antagonist yohimbine (10(-7) and 10(-6) mol/L) partly blocked the suppressive effect of pargyline on the Con A-induced lymphocyte proliferation. Nevertheless, atenolol, an antagonist of beta1-AR, had no blocking effect on pargyline inhibition of lymphocyte proliferation.

CONCLUSIONLymphocytes have the ability to synthesize CAs and the ability is enhanced in the activated lymphocytes. The endogenous CAs synthesized by lymphocytes can inhibit T cell proliferation and the inhibition of T cells by the CAs is mediated predominantly by beta2-AR on the lymphocytes.

Animals ; Catecholamines ; biosynthesis ; physiology ; Cell Proliferation ; drug effects ; Concanavalin A ; pharmacology ; Female ; Lymphocyte Activation ; Lymphocytes ; metabolism ; Male ; Neuroimmunomodulation ; physiology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenergic, beta ; physiology ; T-Lymphocytes ; cytology ; immunology ; Tyrosine 3-Monooxygenase ; genetics ; metabolism

OBJECTIVETo understand the influence of angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and beta3-adrenergic receptor (beta3-AR) gene Trp64Arg polymorphism on fetal growth and neonatal insulin sensitivity.

METHODSTotally 296 newborn infants were selected into our study and divided into 2 groups according to gestational age and birth weight: adequate-for-gestational-age (AGA) group (222 cases) and small-for-gestational-age (SGA) group (74 case). Serum glucose and insulin were examined in the morning of the 3rd day before milk. Insulin sensitivity was evaluated by homeostasis model assessment (HOMA) equation. beta3-AR gene Trp64Arg polymorphism and ACE gene I/D polymorphism (202 cases) were analysed using polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) technique. Gestational age, birth weight, birth weight percentage, serum glucose, insulin and HOMA-IR were compared among different genotype groups. Statistical analysis was performed with the SPSS 10.0 software.

RESULTSNo significant difference was found between the serum glucose level of SGA group (4.03 +/- 1.05 mmol/L) and AGA group (4.05 +/- 1.14 mmol/L), P = 0.008. The serum insulin level (converted into Ln) of SGA group (2.262 +/- 0.746) was significantly higher than that of AGA group (1.757 +/- 0.805), P < 0.001. The HOMA-IR (also converted into Ln) level of SGA group (0.217 +/- 0.367) was also significantly higher than that of AGA group (0.001 +/- 0.378), P < 0.001. In the SGA group beta3-AR gene Arg64 allele carriers had higher serum insulin and HOMA-IR level (both changed to Ln, 2.654 +/- 0.701, 0.371 +/- 0.338) compared with noncarriers (2.074 +/- 0.698, 0.143 +/- 0.360), P < 0.05. The ACE gene DD genotype carriers had higher serum insulin and HOMA-IR level (both were converted into Ln, 2.19 +/- 0.91, 0.51 +/- 1.01) compared with II (1.77 +/- 0.85, 0.02 +/- 0.93) and ID genotype group (1.77 +/- 0.83, 0.05 +/- 0.91), P < 0.05. The ACE gene DD carriers had lower birth weight percentage compared with II and ID genotype group, P < 0.05. When both genes' polymorphisms were taken into account, the newborns who had both DD genotype and Arg64 allele had obviously higher serum insulin level (Ln, 2.560 +/- 1.160) than the neonates who had only one of the polymorphisms mentioned above (1.970 +/- 0.821, 1.992 +/- 0.706) and the neonates who had neither of the two polymorphisms (1.683 +/- 0.832), P < 0.05. The newborns who had both DD genotype and Arg64 allele also had significantly higher HOMA-IR level (Ln, 1.042 +/- 1.315) than the neonates who had only one of the polymorphisms mentioned above (0.247 +/- 0.710, 0.230 +/- 0.890) and the neonates who had neither of the two polymorphisms (-0.053 +/- 0.924), P < 0.05.

CONCLUSIONNewborns SGA had impaired insulin sensitivity. beta3-AR gene Trp64Arg polymorphism and ACE gene I/D polymorphism are important factors that may connect IUGR with insulin resistance syndrome in adulthood.

Female ; Fetal Development ; genetics ; Humans ; INDEL Mutation ; Infant, Newborn ; Infant, Small for Gestational Age ; Insulin Resistance ; Male ; Peptidyl-Dipeptidase A ; genetics ; Polymorphism, Genetic ; Receptors, Adrenergic, beta-3 ; genetics

OBJECTIVETo study the effect of beta3 adrenergic receptor (beta3AR) Trp64Arg and peroxisome proliferator activated receptor gamma 2 (PPARgamma2) Prol2Ala polymorphisms on insulin resistance.

METHODSOne hundred and eight dizygotic twin pairs were enrolled in this study. Microsatellite polymorphism was used to diagnose zygosity of twins. Insulin sensitivity was estimated with logarithm transformed homeostasis model assessment (HOMA). PCR-RFLP analysis was performed to detect the variants. As a supplement to the sib-pair method, identity by state (IBS) was used to analyze the association of polymorphisms with insulin sensitivity.

RESULTSThe genotype frequencies of Trp64Trg, Trp64Arg, and Arg64Arg were 72.3%, 23.8%, and 3.9%, respectively, while the genotype frequencies of Prol2Pro, Prol2Ala, and Alal2Ala were 89.9%, 9.6%, and 0.5%, respectively. For beta3AR Trp64Arg the interclass co-twin correlations of Waist-to-hip ratio (WHR), blood glucose (GLU), and insulin (INS), homeostasis model assessment insulin resistance index (HOMA-IR) of the twin pairs sharing 2 alleles of IBS were greater than those sharing 0-1 allele of IBS, and HOMA-IR had statistic significance. For PPARgamma2 Pro12Ala most traits of twin pairs sharing 2 alleles of IBS had greater correlations and statistic significance in body mass index (BMI), WHR, percent of body fat (PBF) and GLU, but there were low correlations of either insulin or HOMA-IR of twin pairs sharing 1 or 2 alleles of IBS. The combined effects of the two variations showed less squared significant twin-pair differences of INS and HOMA-IR among twins sharing 4 alleles of IBS.

CONCLUSIONSBeta3AR Trp64Arg and PPARgamma2 Pro12Ala polymorphisms might be associated with insulin resistance and obesity, and there might be slight synergistic effects between this two gene loci, and further studies are necessary to confirm this finding.

Adolescent ; Child ; Child, Preschool ; Genotype ; Humans ; Insulin Resistance ; genetics ; Obesity ; genetics ; PPAR gamma ; genetics ; Polymorphism, Genetic ; Receptors, Adrenergic, beta-3 ; genetics ; Twins, Dizygotic ; genetics ; metabolism

BACKGROUNDStimulation of the heart beta 3-adrenoceptor (AR) may result in a negative inotropic effect. Being up-regulated, beta 3-AR plays a more important role in the regulation of cardiac function during heart failure. However, the effect of chronic blocking of beta 3-AR on heart failure has not been fully elucidated. In this study, we used a selective beta 3-AR antagonist SR59230A to treat a well defined heart failure rat model chronically, then evaluated its effect on cardiac function and investigated the mechanism.

METHODSMale Wistar rats were chosen randomly as controls (n = 8). Isoproterenol induced heart failure rats were randomly divided into ISO group (n = 10) and SR group (n = 10). The ISO group received intraperitoneal injection of 1 ml saline twice a day; the SR group received intraperitoneal injection of SR59230A 85 nmol in 1 ml saline twice a day; and the control group received no treatment. The treatment was started 24 hours after the last isoproterenol injection and continued for 7 weeks. Then we measured the following indexes: the ratio of heart weight to body weight (HW/BW) and the ratio of left ventricular weight to body weight (LVW/BW), collagen volume fraction (CVF), left ventricular end diastolic dimension (LVEDd), left ventricular end systolic dimension (LVESd), ejection fraction (EF), fractional shortening (FS) and the ratio of E wave to A wave (E/A), the mRNA and protein expression of beta 3-AR and eNOS, and cGMP level in the heart.

RESULTSThe ratios HW/BW and LVW/BW were significantly increased in the ISO group compared with the control group (P < 0.01), but they were limited in the SR group (P < 0.05 compared with the ISO group). CVF increased in the ISO group and the SR group (P < 0.01), but it was significantly attenuated in the SR group (P < 0.01). LVEDd, LVESd and E/A ratio were significantly increased in the ISO group compared with the control group (P < 0.01), while EF and FS were significantly decreased (P < 0.01). Compared with the ISO group, the SR group showed that LVEDd, LVESd and E/A ratio were significantly decreased (P < 0.01), whereas EF and FS were significantly increased (P < 0.01). beta(3)-AR and eNOS mRNA and protein in the ISO group were significantly increased when compared with the control group (P < 0.01). These increases were all attenuated in the SR group compared with the ISO group (P < 0.01). The level of cGMP in myocardial tissue was significantly increased in the ISO group compared with the control group (P < 0.01), whereas SR59230A treatment normalized this increment (P < 0.01).

CONCLUSIONSChronic blocking of beta 3-AR could ameliorate cardiac function in heart failure rats and its mechanism involves inhibition of the negative inotropic effect and attenuation of cardiac remodeling.

Adrenergic beta-3 Receptor Antagonists ; Adrenergic beta-Antagonists ; pharmacology ; therapeutic use ; Animals ; Blotting, Western ; Disease Models, Animal ; Echocardiography ; Enzyme-Linked Immunosorbent Assay ; Heart Failure ; drug therapy ; physiopathology ; Male ; Myocardium ; pathology ; Nitric Oxide Synthase Type III ; genetics ; Propanolamines ; pharmacology ; Rats ; Rats, Wistar ; Receptors, Adrenergic, beta-3 ; physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Ventricular Function, Left ; drug effects

OBJECTIVETo investigate the alteration of expressions of beta(1)-, beta(2)-, beta(3)-adrenoceptor mRNA in human myocardial tissue and the relation between their expressions and cardiac function in patient with heart failure.

METHODSThe mRNA expressions of beta(1)-, beta(2)- and beta(3)-adrenergic receptors in myocardial tissue were analyzed by using the reverse transcriptase-polymerase chain reaction in 24 patients with heart failure of valvular heart disease and 5 control subjects.

RESULTSBeta(1)-adrenergic receptor mRNA expressions in myocardium were significantly lower in patients with heart failure than those in control subjects, and progressively reduced with aggravation of heart function. By contrast, beta(3)-adrenoceptor mRNA expressions were significantly higher in patients with heart failure than those in controls, and progressively elevated with aggravation of cardiac function. No difference was observed in beta(2)-adrenergic receptor among all groups.

CONCLUSIONThe changes of beta-adrenergic receptor mRNA expression are associated with the severity of heart failure.

Adult ; Case-Control Studies ; Female ; Heart Failure ; genetics ; metabolism ; physiopathology ; Humans ; Male ; Middle Aged ; RNA, Messenger ; metabolism ; Receptors, Adrenergic, beta-1 ; genetics ; metabolism ; Receptors, Adrenergic, beta-2 ; genetics ; metabolism ; Receptors, Adrenergic, beta-3 ; genetics ; metabolism

DNA was extracted from the peripheral venous blood of 338 subjects using BLOOD DNA MINI KIT. The 5 site SNP in 3 subtypes of Beta-AR were genotyped by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) and allele-specific primer PCR techniques. The genotypes combination distribution of SNP at 5 sites in the 3 subtypes of Beta-AR were determined by clustering analysis technique. The natural combination distribution characteristics for SNP at 5 sites in the 3 subtypes of Beta-AR in 338 subjects were obtained. Sixty-seven combinations types were found. The preceding 5 combinations in the natural combination distribution of the SNP were: (1) The genotype combination of forty subjects was B1-AR S/S49+B1-AR R/R389+B2-AR R/G16+B2-AR Q/E27+B3-AR W/W64, its probability was 11.83%. (2) The genotype combination of thirty-three subjects was B1-AR S/S49+B1-AR R/R389+B2-AR R/G16+B2-AR Q/Q27+B3-AR W/W64, its probability was 9.76%. (3) The genotype combination of nineteen subjects was B1-AR S/S49+B1-AR R/G389+B2-AR R/G16+B2-AR Q/Q27+B3-AR W/W64, its probability was 5.62%. (4) The genotype combination of sixteen subjects was B1-AR S/S49+B1-AR R/G389+B2-AR R/G16+B2-AR Q/E27+B3-AR W/W64, its probability was 4.74%. (5) The genotype combination of thirteen subjects was B1-AR S/G49+B1-AR R/R389+B2-AR R/G16+B2-AR Q/E27+B3-AR W/W64, its probability was 3.85%. The obvious correlations exist among full sample and female or male subgroup, and between female and male subgroups.
Adult ; Aged ; Aged, 80 and over ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Polymerase Chain Reaction ; methods ; Polymorphism, Single Nucleotide ; genetics ; Receptors, Adrenergic, beta ; classification ; genetics ; Receptors, Adrenergic, beta-1 ; genetics ; Receptors, Adrenergic, beta-2 ; genetics ; Receptors, Adrenergic, beta-3 ; genetics