OBJECTIVE: To investigate the effect of adiponectin on the osteoblast differentiation and its signal transduction. METHODS: Adipopnectin receptor (AdipoR) was detected by immunoblot analysis. Alkaline phosphatase (ALP) activity was measured by enzyme-linked immunosorbent assay. Osteocalcin was measured by a specific radioimmunoassay kit, and the extent of mineralized matrix was determined. RNA interference was used to down-regulate the expression of AdipoR1 in human osteoblasts, and the effect of adiponectin on osteoblast differentiation was investigated. RESULTS: Only AdipoR1 protein was detected in human osteoblasts. Adiponectin could promote osteoblast differentiation, and result in a dose-dependent increase in ALP activity, osteocalcin secretion, and an increase in mineralized nodules. Suppression of AdipoR1 with siRNA could abolish the adiponectin induced ALP expression. Adiponectin could induce the activation of p38 and JNK, but not ERK1/2 in osteoblasts, and the pretreatment of osteoblasts with the p38 inhibitor (SB203580) could block the adiponectin-induced ALP activity. CONCLUSION Adiponectin can induce human osteoblast differentiation via AdipoR1/p38 pathway.
Adiponectin ; pharmacology ; Alkaline Phosphatase ; metabolism ; Cell Differentiation ; drug effects ; Cells, Cultured ; Humans ; Osteoblasts ; cytology ; metabolism ; Osteocalcin ; analysis ; RNA, Small Interfering ; genetics ; Receptors, Adiponectin ; biosynthesis ; Signal Transduction

OBJECTIVETo investigate the effect of adiponectin on hepatocyte steatosis.

METHODSL02 cells were transfected with pEGFP-N1-AdipoQ, a plasmid encoding pEGFP-adiponectin fusion protein, or pEGFP-N1. Lipid droplets in the hepatocytes were observed by oil red staining at 72 h. The contents of TG, FFA and glycerol in hepatocytes were measured.

RESULTSCompared to cells transfected with pEGFP-N1-AdipoQ plasmid, much more lipid droplets were observed in cells transfected with pEGFP-N1 plasmid. TG, FFA and glycerol contents in L02 cells and L02/pEGFP-N1 cells were significantly higher than those in L02/pEGFP-N1-AdipoQ cells.

CONCLUSIONSOverexpression of adiponectin prevent hepatocyte steatosis.

Adiponectin ; genetics ; Cell Line ; Fatty Acids, Nonesterified ; analysis ; Fatty Liver ; metabolism ; Genetic Vectors ; Glycerol ; analysis ; Hepatocytes ; cytology ; metabolism ; Humans ; Plasmids ; Recombinant Fusion Proteins ; genetics ; Transfection ; Triglycerides ; analysis

OBJECTIVETo understand adiponectin, leptin, insulin and ghrelin levels in preterm colostrum and mature milk and their influence on the growth and development of the premature infant.

METHODThe study subjects were divided into two groups: preterm group and control group. Specimens of colostrum and mature milk on 42nd day after delivery were collected, the general situation of maternal and infants growth parameters at birth and at postnatal 42 days were recorded. Leptin, adiponectin, insulin and ghrelin levels in colustrum and mature milk were determined and compared.

RESULTA total of 128 mother-infant pairs were involved. There were 128 specimens of colostrums (80 from preterm group, 48 from control group) and 94 specimens of mature milk(50 from premature group, 44 from control group). The levels of colostrum, mature milk adiponectin, leptin, and insulin were not significantly different between the 2 groups; ghrelin levels in colostrum and mature milk of premature group were significantly lower than those in control group (P = 0.038), adiponectin and leptin levels in colostrum were higher than those of the mature milk (P < 0.05), colostrum ghrelin levels were lower than those of mature milk (P < 0.05). Adiponectin, leptin, and ghrelin showed no significant difference between different gestational age groups ( ≤ 34 weeks group vs. > 34 weeks group). True insulin level of mature milk in 34 weeks group was higher than that of > 34 weeks group (29.3 vs. 21.6 mU/L, P = 0.045); true insulin level in colostrums in ≤ 34 weeks group was lower than that in mature milk (21.7 vs. 29.3 mU/L, P = 0.000). Adiponectin levels in colostrum and 42 days weight gain were negatively correlated (r = -0.362, P = 0.025) . Insulin level in mature milk had a negative correlation with birth weight (r = -0.319, P = 0.029) . Ghrelin levels in colostrum and birth weight, length, head circumference, head circumference on 42(nd) day were positively correlated (r = 0.271,0.261,0.360, P < 0.05); weight, length at 42(nd) day and ghrelin levels showed borderline positive correlation (P = 0.050, 0.058).

CONCLUSIONMany bioactive hormones in milk might participate in the regulation of suitable growth after birth. Premature birth affects hormone levels in breast milk. Breast feeding is very important in preterm infants.

Adiponectin ; analysis ; Birth Weight ; physiology ; Breast Feeding ; Colostrum ; chemistry ; Female ; Gestational Age ; Ghrelin ; analysis ; Humans ; Infant ; Infant Nutritional Physiological Phenomena ; Infant, Newborn ; Infant, Premature ; growth & development ; Insulin ; analysis ; Leptin ; analysis ; Male ; Milk, Human ; chemistry ; Weight Gain ; physiology

We hypothesized that lower proportion of serum phospholipid docosahexaenoic acid (DHA) is inversely associated with increased cardiovascular risk and vascular function in metabolically healthy men. To elucidate it, we first compared serum phospholipid free fatty acid (FA) compositions and cardiovascular risk parameters between healthy men (n = 499) and male patients with coronary artery disease (CAD, n = 111) (30-69 years) without metabolic syndrome, and then further-analyzed the association of serum phospholipid DHA composition with arterial stiffness expressed by brachial-ankle pulse wave velocity (ba-PWV) in metabolically healthy men. Basic parameters, lipid profiles, fasting glycemic status, adiponectin, high sensitivity C-reactive protein (hs-CRP) and LDL particle size, and serum phospholipid FA compositions were significantly different between the two subject groups. Serum phospholipid DHA was highly correlated with most of long-chain FAs. Metabolically healthy men were subdivided into tertile groups according to serum phospholipid DHA proportion: lower (< 2.061%), middle (2.061%-3.235%) and higher (> 3.235%). Fasting glucose, insulin resistance, hs-CRP and ba-PWVs were significantly higher and adiponectin and LDL particle size were significantly lower in the lower-DHA group than the higher-DHA group after adjusted for confounding factors. In metabolically healthy men, multiple stepwise regression analysis revealed that serum phospholipid DHA mainly contributed to arterial stiffness (β'-coefficients = -0.127, p = 0.006) together with age, systolic blood pressure, triglyceride (r = 0.548, p = 0.023). Lower proportion of serum phospholipid DHA was associated with increased cardiovascular risk and arterial stiffness in metabolically healthy men. It suggests that maintaining higher proportion of serum phospholipid DHA may be beneficial for reducing cardiovascular risk including arterial stiffness in metabolically healthy men.
Adiponectin ; Blood Pressure ; C-Reactive Protein ; Coronary Artery Disease ; Fasting ; Glucose ; Humans ; Insulin Resistance ; Male ; Particle Size ; Pulse Wave Analysis ; Triglycerides ; Vascular Stiffness*

BACKGROUND AND OBJECTIVES: Ramipril and candesartan have decreased the incidence of new onset diabetes in large scale randomized clinical studies. Because ramipril and candesartan have distinct mechanisms of action in the renin angiotensin aldosterone system, we hypothesized that combination therapy would have additive beneficial metabolic effects in patients with hypertension. SUBJECTS AND METHODS: Thirty-four patients were given ramipril 10 mg and placebo, ramipril 10 mg and candesartan 16 mg, or candesartan 16 mg and placebo daily in a randomized, double-blind, placebo-controlled cross-over trial with three treatment arms and two washout periods (each being 2 months). RESULTS: Ramipril, combination therapy or candesartan significantly increased the plasma adiponectin levels relative to the baseline measurements by 17+/-6% (p=0.038), 25+/-5% (p<0.001), and 14+/-6% (p=0.016), respectively. Combination therapy significantly increased the plasma adiponectin levels more than either ramipril or candesartan alone (p=0.020 by ANOVA). Only combination therapy significantly increased the QUICKI level relative to the baseline measurements (p=0.002). There were no significant correlations between these changes of the metabolic parameters and reduction of the systolic blood pressure (-0.288< or =r< or =0.284) and reduction of the diastolic blood pressure (-0.282< or =r< or =0.190). On multivariate analysis, only the change of adiponectin levels was an independent predictor of the changes in the QUICKI levels (beta=1.549, p=0.040) following combination therapy. CONCLUSION: Ramipril in combination with candesartan increases the plasma adiponectin levels to a greater extent than monotherapy with either drug alone. Only combination therapy significantly improves insulin sensitivity relative to the baseline measurements. The only predictor for the improvement of insulin sensitivity is the increase of plasma adiponectin levels by combination therapy.
Adiponectin* ; Angiotensin-Converting Enzyme Inhibitors ; Arm ; Blood Pressure ; Humans ; Hypertension ; Incidence ; Insulin Resistance* ; Insulin* ; Multivariate Analysis ; Plasma* ; Ramipril* ; Renin-Angiotensin System

BACKGROUNDThe fat derived protein adiponectin plays an important role in the regulation of glucose metabolism. The aim of this study was to provide the experimental basis for further investigating on adiponectin (ADPN) function. Its eukaryotic recombinant was constructed and expressed in precursor cells of 3T3-L1 adipocytes. The effects of dexamethasone on peroxisome proliferator activated receptor-gamma (PPAR-gamma) mRNA expression in 3T3-L1 cells with human recombinant adiponectin were assessed.

METHODSThe recombinant plasmid pMD18-T-hADPN and eukaryotic expression vector pcDNA3.1(+) were digested by two restrictive endonucleases and adiponectin and linear pcDNA3.1(+) were obtained. Then, they were ligated and translated into JM109. The recombinant pcDNA3.1(+)-hADPN so obtained was identified by digestion by restrictive endonuclease and nucleotide sequencing. The 3T3-L1 precursor cells were transfected using SuperFect Transfection Reagent (Qiagen). Furthermore, 3T3-L1 cells with human recombinant adiponectin incubated with dexamethasone (0.5 mmol/L) for 24 hours, cells were collected and total RNA was extracted. The PPAR-gamma mRNA expression was quantified by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSAfter eukaryotic recombinant was digested by Hind III and EcoR I, fragments of 800 bp and 5.4 kb were identified by nucleotide sequence scanning and consistent with theoretical values. Electrophoretogram of RT-PCR in 3T3-L1 precursors showed only one band in front of 250 bp, which was consistent with theoretical value 234 bp. In the 3T3-L1 cells, 3T3-L1 cells with plasmid and 3T3-L1 cells human recombinant adiponectin, treatment with dexamethasone (0.5 mmol/L) decreased PPAR-gamma mRNA expression compared to untreated controls (P < 0.01). Effect of dexamethasone on PPAR-gamma mRNA expression in 3T3-L1 cells was reversed by stably transfected human recombinant adiponectin.

CONCLUSIONThe 3T3-L1 cells stably transfected human recombinant adiponectin had increased PPAR-gamma mRNA expression. Dexamethasone suppressed PPAR-gamma mRNA expression in the 3T3-L1 cells. Effect of dexamethasone on PPAR-gamma mRNA expression in 3T3-L1 cells was reversed by stably transfected human recombinant adiponectin.

3T3-L1 Cells ; Adiponectin ; physiology ; Animals ; Dexamethasone ; pharmacology ; Insulin Resistance ; Mice ; PPAR gamma ; genetics ; RNA, Messenger ; analysis ; Reverse Transcriptase Polymerase Chain Reaction

Adiponectin ; blood ; C-Reactive Protein ; analysis ; Cardiovascular Diseases ; etiology ; Continuous Positive Airway Pressure ; Humans ; Inflammation ; complications ; Sleep Apnea, Obstructive ; blood ; complications ; therapy

OBJECTIVETo study the distribution characteristics of adiponectin gene +45 single nucleotide polymorphisms (SNP) in Chinese children, and to determine the role of adiponectin gene +45 polymorphisms in the pathogenesis of childhood obesity.

METHODSA total of 147 Chinese obese and 118 healthy children were randomly selected and enrolled to identify adiponectin gene SNP+45 polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Plasma adiponectin levels were determined using ELISA. Waist circumference (WC), waist to hip ratio (WHR), percentage of body fat (%BF), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG), serum triglycerides (TG), total cholesterol (TC), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), plasma fasting insulin (FINS), and homeostasis model assessment of insulin resistance (HOMA-IR) were measured.

RESULTSThe allelic frequency of adiponectin gene SNP+45 in children with obesity and healthy controls were 40.5% and 25.4%, respectively. There were significant differences in the distribution of genotypes and the allelic frequency between the two groups (P<0.05). The plasma adiponectin levels were significantly higher, in contrast, %BF, HOMA-IR, TC and LDL-C levels were significantly lower in obese children with TT genotype than those in obese children with TG or GG genotype.

CONCLUSIONSThe adiponectin gene SNP+45 polymorphism may be associated with pathogenesis of obesity in children. T→G variance may be associated an increased risk of childhood obesity and result in a decreased level of adiponectin.

Adiponectin ; genetics ; Adolescent ; Blood Glucose ; analysis ; Blood Pressure ; Child ; Female ; Genotype ; Humans ; Lipids ; blood ; Male ; Obesity ; blood ; etiology ; genetics ; Polymorphism, Single Nucleotide

OBJECTIVETo examine plasma adiponectin (ADPN) and tumor necrosis factor-alpha (TNF-alpha) levels and their correlation in children with obesity in order to investigate the roles of both in the development of childhood obesity.

METHODSOne hundred and forty-seven children with obesity and 118 normal children who were randomly sampled from five primary schools from the Kaifu District in Changsha were enrolled. Physical shape indexes, including height, weight, waist circumference, hip circumference, and waist to hip ratio (WHR) were measured. Body mass index (BMI) was calculated. Blood pressure was measured. Percentage of body fat (%BF) was measured with dual energy X-ray absorptiometry. Plasmal levels of ADPN and TNF-alpha were detected using ABC-ELISA. Blood concentrations of triglycerides (TG), total cholesterol (TC), high density lipoprotein-cholesterol (HDL-C) and low density lipoprotein-cholesterol (LDL-C) were measured by automatic biochemistry analyzer. Fasting blood glucose level was measured by glucose oxidase method. Fasting blood insulin level was assayed by radioimmunity. Homeostasis model assessment for insulin resistance (HOMA-IR) was performed.

RESULTSPlasma ADPN levels in obese children significantly decreased compared with those in normal children (8.12+/-2.54 mg/L vs 12.22+/-4.68 mg/L; p<0.05), and had a negative correlation with plasma TNF-alpha levels, BMI, WHR and HOMA-IR (p<0.01), and with %BF, fasting insulin, systolic blood pressure and TG (p<0.05). Plasma TNF-alpha levels in obese children significantly increased compared to normal children (171.38+/-34.33 ng/L vs 91.07+/-21.60 ng/L; p<0.01) and positively correlated with BMI, WHR, %BF, fasting insulin, HOMA-IR, TG and systolic blood pressure (p<0.01), and negatively with HDL (p<0.05). Multiple stepwise regression analysis showed that ADPN, BMI and TNF-alpha were main influential factors for %BF (R2=0.926, p<0.01). There was a significant interaction between ADPN and TNF-alpha (p<0.05).

CONCLUSIONSPlasma ADPN levels decreased and plasma TNF-alpha levels increased in children with obesity and both were main influential factors for %BF in children. There was an interaction between ADPN and TNF-alpha, suggesting that they both participate in the development of childhood obesity.

Adiponectin ; blood ; Adolescent ; Blood Pressure ; Body Mass Index ; Child ; Cholesterol, HDL ; blood ; Female ; Humans ; Insulin Resistance ; Male ; Obesity ; blood ; etiology ; Regression Analysis ; Tumor Necrosis Factor-alpha ; blood

OBJECTIVETo investigate the changes and value of plasma angiopoietin-related growth factor (AGF) in patients with abdominal aortic aneurysm (AAA).

METHODSSerum AGF level was analyzed in 50 AAA patients and in 56 healthy subjects. AGF and adiponectin were quantified by enzyme-linked immunosorbent assay. Routine testing of blood biochemistry and high-sensitivity C-reactive protein were performed.

RESULTSThe plasma AGF level was significantly higher in AAA patients than in the controls [(87.91±96.87) μg/L vs. (56.89±41.32) μg/L, P=0.040],while serum adiponectin level showed no significant difference between these two groups. The plasma AGF level in patients with an AAA>5 cm and those with AAA between 3 cm and 5 cm were (96.08±68.61) μg/L and (75.27±46.05) μg/L.

CONCLUSIONSPlasma AGF is highly expressed in AAA patients. Higher serum AGF level is associates with larger AAA. Thus, AGF may be a potential serum biomarker for AAA.

Adiponectin ; blood ; Angiopoietin-like Proteins ; Angiopoietins ; blood ; Aortic Aneurysm, Abdominal ; blood ; Biomarkers ; blood ; C-Reactive Protein ; analysis ; Case-Control Studies ; Enzyme-Linked Immunosorbent Assay ; Humans