Molecular cloning, characterisation, and expression analysis of adipocyte fatty acid binding protein gene in Xupu goose (Anser cygnoides domesticus)

1. Adipocyte fatty acid binding protein (A-FABP) plays a key role in fatty acid uptake and intracellular transport. The objective of the present study was to identify and characterise the A-FABP gene in Xupu goose.2. The full-length cDNA of goose A-FABP gene was cloned from the liver tissue using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The distribution of the goose A-FABP in different tissues was determined by quantitative real-time PCR (qRT-PCR).3. The results showed that the full-length cDNA sequence of goose A-FABP was 657 bp, containing a 5'-UTR of 52 bp, a 3'-UTR of 206 bp and an open reading frame (ORF) of 399 bp, which encoded a polypeptide of 132 amino acids (AA).4. The AA sequence of goose A-FABP showed 76.52%, 75.00%, 93.18% and 99.24% identities with previously described homologues from humans (Homo sapiens), mouse (Mus musculus), chicken (Gallus gallus), and duck (Anas platyrhynchos), respectively, and phylogenetic analysis revealed a close relationship among them. The transcript of Xupu goose A-FABP was ubiquitously expressed in all tested tissues, and showed a high-level expression in abdominal fat, sebum and liver.5. A significant positive correlation was identified between A-FABP mRNA abundance in the three adipose tissues and liver weight, ratio of liver to body weight, TG content, and VLDL concentration in the plasma of Xupu goose. A significant negative correlation was observed between the mRNA level of A-FABP and HDL concentration in the plasma of Xupu goose.6. These findings provide a foundation for further research on the function and mechanism of A-FABP in the fat deposition process.

Positive Association of Serum Adipocyte Fatty Acid Binding Protein Level With Peripheral Artery Disease in Hemodialysis Patients

Adipocyte fatty acid binding protein is positively associated with atherosclerosis. Peripheral arterial disease is associated with an increased mortality in hemodialysis patients. This study aimed to evaluate the relationship between serum adipocyte fatty acid binding protein levels and peripheral arterial disease by ankle-brachial index in hemodialysis patients. Among the 90 chronic hemodialysis recipients, 20 patients (22.2%) were in the low ankle-brachial index group who had a higher prevalence of diabetes, hyperlipidemia, statin use, older age, higher body fat mass, higher serum adipocyte fatty acid binding protein level, and lower serum creatinine level compared with patients in the control group. After statistical analysis, body fat mass (P = 0.006) and creatinine level (P = 0.018) were shown to be the independent predictors of adipocyte fatty acid binding protein level. Serum adipocyte fatty acid binding protein (P = 0.021) was found to be positively associated with peripheral arterial disease in hemodialysis patients.

High serum adipocyte fatty acid binding protein concentration linked with increased aortic arterial stiffness in patients with type 2 diabetes

BACKGROUND

Adipocyte fatty acid binding protein (A-FABP) is a novel adipokine that contributes to the development of metabolic disorder, type 2 diabetes mellitus (T2DM) and atherosclerosis. We determined the correlation between serum A-FABP and aortic stiffness in T2DM patients.

METHODS

Fasting blood samples were obtained from 156 patients with T2DM. Serum A-FABP concentration were determined using a commercial enzyme immunoassay. Carotid-femoral pulse wave velocity (cfPWV) was measured using SphygmoCor System, and cfPWV values of >10 m/s were defined as high aortic stiffness.

RESULTS

Sixty participants (38.4%) fell under the high aortic stiffness group. This group, compared to the control group, showed older age (P = .004), higher systolic blood pressure (P < .001), diastolic blood pressure (P = .027), urine albumin-to-creatinine ratio (P = .003), serum A-FABP (P < .001) and lower estimated glomerular filtration rate (P = .001). After adjusting for factors significantly associated with aortic stiffness using multivariable logistic regression analysis, serum A-FABP [OR = 1.029 (1.002-1.058), P = .039] was found to be an independent predictor of aortic stiffness in T2DM patients.

CONCLUSIONS

Serum A-FABP is positively correlated with aortic arterial stiffness in patients with T2DM.

High serum adipocyte fatty acid binding protein level as a potential biomarker of aortic arterial stiffness in hypertensive patients with metabolic syndrome

BACKGROUND

The adipocyte-fatty-acid-binding protein (A-FABP) has been implicated in arterial stiffness, metabolic syndrome (MetS), and cardiovascular disease. We aimed to determine the relationship among serum A-FABP concentration, cardiometabolic risk factors, and central arterial stiffness in a hypertensive population.

METHODS

Fasting blood samples and baseline characteristics were obtained from 110 hypertensive patients. Serum A-FABP concentrations were determined by enzyme immunoassay kit. High arterial stiffness was defined as carotid-femoral pulse wave velocity values >10m/s via the SphygmoCor system.

RESULTS

Patients with MetS and high arterial stiffness accounted for 67.3% and 42.7% of the study population, respectively. Serum A-FABP was positively associated with MetS and high arterial stiffness (P=0.006 and P<0.001, respectively). Multivariable stepwise linear regression analysis of the significant variables of arterial stiffness revealed that logarithmically transformed A-FABP (log-A-FABP, β=0.278, P=0.002) was positively correlated arterial stiffness in hypertensive patients. Subgroup analysis revealed that log-A-FABP (β=0.327, P=0.003), age (β=0229, P=0.032), and triglyceride (β=0.307, P=0.004) were significantly positively correlated with arterial stiffness in hypertensive patients with MetS.

CONCLUSIONS

Elevated A-FABP concentration could be a predictor for MetS and arterial stiffness in hypertensive patients.

Positive correlation of serum adipocyte fatty acid binding protein levels with metabolic syndrome in kidney transplantation patients

Adipocyte fatty acid binding protein (A-FABP) is significantly expressed in white and brown adipose tissue, monocytes, and macrophages and is a central regulator of systemic insulin sensitivity. Metabolic syndrome (MetS) is a risk factor for post-transplant diabetes mellitus (PTDM), chronic graft dysfunction, graft loss, and patient death in kidney transplantation (KT) patients. This study was undertaken to evaluate the relationship between MetS and fasting serum A-FABP concentration in KT patients. Fasting blood samples were obtained from 70 KT patients. Serum A-FABP levels were measured using a commercial enzyme-linked immunosorbent assay kit. MetS and its components were defined using the diagnostic criteria of the International Diabetes Federation. Twenty-two patients (31.4%) had MetS. KT patients with hypertension (P = 0.011), diabetes (P = 0.002), body weight (P = 0.004), body mass index (BMI, P = 0.001), waist circumference (P < 0.001), body fat mass (P < 0.001), systolic blood pressure (SBP, P = 0.017), total cholesterol (TCH, P = 0.028), triglycerides (TG, P = 0.001), blood urea nitrogen (BUN, P = 0.003), insulin (P < 0.001), homeostasis model assessment of insulin resistance (HOMA-IR, P < 0.001), and A-FABP level (P < 0.001) were higher, while high-density lipoprotein cholesterol (HDL-C, P = 0.010) was lower in KT patients with MetS. Moreover, SBP (β = 0.347, adjusted R² change = 0.108, P = 0.001) and logarithmically transformed triglycerides (log-TG, β = 0.393, adjusted R² change = 0.189, P < 0.001) were associated with A-FABP levels in a multivariable forward stepwise linear regression analysis among KT patients. The results of our study showed that the fasting A-FABP level was positively associated with MetS in KT patients. SBP and log-TG were independent predictors of the serum A-FABP level among KT patients.

Changes in serum adipocyte fatty acid-binding protein in women with gestational diabetes mellitus and normal pregnant women during mid- and late pregnancy

Aims/Introduction

To observe the longitudinal changes in serum adipocyte fatty acid‐binding protein (AFABP), carbohydrate, and lipid metabolism parameters in women with and without gestational diabetes mellitus (GDM) during mid‐ and late pregnancy periods, as well as to identify whether there is any association between AFABP and development of GDM.

Materials and Methods

A total of 40 GDM and 240 normal glucose tolerance participants were enrolled at 24–28 weeks and completed the study. The clinical features, serum AFABP, other adipocytokines (leptin, adiponectin, retinol‐binding protein 4), homeostasis model assessment of insulin resistance, and lipid profiles were measured in the second and third trimesters of pregnancy.

Results

Compared with the normal glucose tolerance group, the GDM group showed greater levels of AFABP, leptin and retinol‐binding protein 4; and a decreased level of adiponectin (P < 0.05 or P < 0.01) during mid‐ and late pregnancy periods. Prepregnancy body mass index was the independent factor impacting serum AFABP levels in the second (β = 0.567, P = 0.004) and third trimesters (β = 0.619, P = 0.001). Furthermore, GDM was independently associated with AFABP concentrations in multiple regression analysis in the second and third trimester (all P < 0.01). Serum AFABP, leptin and retinol‐binding protein 4 are risk factors for GDM; adiponectin is a protective factor for GDM (P < 0.05 or P < 0.01).

Conclusions

The GDM group had a higher level of AFABP during mid‐ and late stages of pregnancy; prepregnancy body mass index and GDM were the independent factors with respect to serum AFABP. AFABP might be closely related to obesity, insulin resistance and leptin resistance in pregnancy, and is a major risk factor for GDM.

The mAb against adipocyte fatty acid-binding protein 2E4 attenuates the inflammation in the mouse model of high-fat diet-induced obesity via toll-like receptor 4 pathway

Adipocyte fatty acid-binding protein (A-FABP) plays an important role in fatty acid-mediated processes and related metabolic and inflammatory responses. In this study, we prepared a novel monoclonal antibody against A-FABP, designated 2E4. Our data showed that 2E4 specifically binded to the recombinant A-FABP and native A-FABP of mice adipose tissue. Furthermore, we investigated the effect of 2E4 on metabolic and inflammatory responses in C57BL/6J obese mice fed on a high fat diet. 2E4 administration improved glucose response in high-fat-diet induced obese mice. The 2E4 treated groups exhibited lower free fatty acids, cholesterol, and triglycerides in a concentration-dependent manner. These changes were accompanied by down-regulated expression of pro-inflammatory cytokines in adipose tissue, including tumor necrosis factor α, monocyte chemotactic protein-1, and interleukin-6. Meanwhile, our data demonstrated that 2E4 significantly decreased the mRNA and protein levels of A-FABP in adipose tissue of mice. Further experiments showed that 2E4 notably suppressed the phosphorylation of IκBα and jun-N-terminal kinase through toll-like receptor 4 signaling pathway. Taken together, 2E4 is an effective monoclonal antibody against A-FABP, which attenuated the inflammatory responses induced in the high-fat-diet mice. These findings may provide scientific insight into the treatment of chronic low-grade inflammation in obesity.

Lipocalin-2, A-FABP and inflammatory markers in relation to flow-mediated vasodilatation in patients with essential hypertension

Lipocalin families including lipocalin-2 and adipocyte fatty acid binding protein (A-FABP) were recently identified as novel adipokines to be associated with the cardiovascular risk variables of the metabolic syndrome. We evaluated the lipocalin-2 and A-FABP levels in 62 patients with essential hypertension (EHT) and 16 age-, gender- and body mass index-matched normotensive healthy subjects (NT). Furthermore, we evaluated the correlation between lipocalin-2, A-FABP levels, inflammatory markers including hsCRP and IL-10, and flow-mediated vasodilatation (FMD). In EHT, circulating lipocalin-2 levels were significantly higher than in NT (85.0 ± 37.6 ng/ml versus 43.8 ± 13.1 ng/ml, p < 0.001). However, A-FABP levels were not different between patients with EHT and NT. Serum lipocalin-2 levels were positively associated with SBP (r = 0.54, p < 0.001), DBP (r = 0.34, p = 0.003) and fasting glucose levels (r = 0.25, p = 0.032), On the other hand, circulating A-FABP levels were significantly associated with variables such as BMI, fasting insulin, insulin resistance index and hsCRP. Multiple linear regression analysis showed that mean arterial pressure was associated with fasting glucose, lipocalin-2 levels, age, BMI and hsCRP levels (R²= 0.456). However, circulating lipocalin-2 levels were not associated with FMD. In conclusion, lipocalin-2 levels were significantly higher in patients with EHT, and were independently associated with mean arterial pressure.

Obesity as the common soil of non-alcoholic fatty liver disease and diabetes: Role of adipokines

Non‐alcoholic fatty liver disease (NAFLD) describes a spectrum of liver conditions from simple steatosis, steatohepatitis to end‐stage liver disease. The prevalence of NAFLD has been on the rise in many parts of the world, including Asia, and NAFLD is now the liver disease associated with the highest mortality, consequent to the increased risk of cardiovascular diseases and hepatocellular carcinoma. Whereas NAFLD is an independent risk factor for type 2 diabetes, increased hepatic and peripheral insulin resistance contribute to the pathogenesis of both NAFLD and diabetes, which are associated with enhanced cardiovascular risk. Studies in humans and animal models have suggested obesity as the common link of these two diseases, likely mediated by adipose tissue inflammation and dysregulated adipokine production in obesity. In the present review, we discuss recent advances in our understanding of the role of several novel adipokines (adiponectin, adipocyte fatty acid binding protein and fibroblast growth factor‐21) in the pathophysiology of NAFLD and diabetes, as well as their use as potential biomarkers and therapeutic targets for dysglycemia in NAFLD patients.