Adiponectin: key role and potential target to reverse energy wasting in chronic heart failure

Low serum adiponectin level is associated with better physical health-related quality of life in chronic kidney disease

Hyperadiponectemia is paradoxically associated with renal disease progression and mortality in chronic kidney disease (CKD). Its association with health-related quality of life (HR-QOL) is unknown. This study aimed to verify the association between adiponectin and HR-QOL in Korean pre-dialysis CKD cohort. This cross-sectional study analyzed 1551 pre-dialysis CKD patients from KNOW-CKD (KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease). Participants were categorized into three tertiles (T1–T3) according to adiponectin levels. HR-QOL was assessed using SF-36. High physical component summary (PCS) and mental component summary (MCS) were defined as highest quartile of each score. Multivariate logistic regression was used to analyze odds ratio (OR) and 95% confidence interval (CI) for high PCS and MCS. Prevalence of high PCS were 33.3%, 27.5%, and 17.0% and that of high MCS were 31.7%, 24.8%, and 21.3% for T1, T2, and T3 (both p for trend < 0.001). The adjusted OR [95% CI] of T1 and T2 in reference to T3 were 1.56 [1.09–2.23] and 1.19 [0.85–1.68] for high PCS and 1.19 [0.85–1.68] and 0.94 [0.68–1.29] for high MCS. Serum adiponectin level was inversely associated with physical HR-QOL in Korean pre-dialysis CKD patients. This relationship was independent of various cardiovascular risk factors.

Leptin, Galectin-3 and Angiotensin II Type 1 Receptor Polymorphism in Overweight and Obese Patients with Heart Failure - Role and Functional Interplay

Background and Aims

Leptin, one of the best-known adipocytes, together with the renin-angiotensin-aldosterone system and galectin-3 are important players in inflammation, arterial hypertension and heart failure pathophysiology. Moreover, uninucleotide A1166C polymorphism is associated with hypertension and poor prognosis in heart failure. The aim of the study was to investigate a possible relationship between leptin serum values, specific heart failure biomarkers and the presence of AT1 receptor A1166C polymorphism in overweight and obese heart failure patients.

Methods

The study included 88 consecutive overweight and obese patients admitted for decompensated heart failure. NT-proBNP, MR-proANP, galectin-3 and leptin levels were determined on the arrival day. Genotyping of the A1166C allele – AT1 receptor gene was performed in all patients in order to find variants.

Results

We found a strong positive correlation (r = 0.347, p = 0.001) between leptin serum concentrations and BMI. Leptin levels were not correlated with heart failure biomarkers (NT-proBNP, MR-proANP and galectin-3). All homozygote CC variants were hypertensive, but we registered no significant difference in genetic AC and AA variants distribution between hypertensive and normotensive. Leptin was not significantly modified by the presence of potentially pathogenic A1166C–AT 1 receptor genotypes (AC + CC). But, galectin-3 was found in higher concentrations in patients with heterozygous and homozygous A1166C mutations.

Conclusion

Overweight and obese patients with heart failure display high leptin serum levels. Leptin does not offer incremental prognostic value in heart failure overweight and obese patients. But, galectin-3 was found in higher concentrations in patients with heterozygous and homozygous A1166C mutations, suggesting a worse prognosis probably due to more advanced cardiac fibrosis.

Emerging Role of Adipocyte Dysfunction in Inducing Heart Failure Among Obese Patients With Prediabetes and Known Diabetes Mellitus

Adipose tissue dysfunction is a predictor for cardiovascular (CV) events and heart failure (HF) in patient population with obesity, metabolic syndrome, and known type 2 diabetes mellitus. Previous preclinical and clinical studies have yielded controversial findings regarding the role of accumulation of adipose tissue various types in CV risk and HF-related clinical outcomes in obese patients. There is evidence for direct impact of infiltration of epicardial adipocytes into the underlying myocardium to induce adverse cardiac remodeling and mediate HF development and atrial fibrillation. Additionally, perivascular adipocytes accumulation is responsible for release of proinflammatory adipocytokines (adiponectin, leptin, resistin), stimulation of oxidative stress, macrophage phenotype switching, and worsening vascular reparation, which all lead to microvascular inflammation, endothelial dysfunction, atherosclerosis acceleration, and finally to increase in CV mortality. However, systemic effects of white and brown adipose tissue can be different, and adipogenesis including browning of adipose tissue and deficiency of anti-inflammatory adipocytokines (visfatin, omentin, zinc-α2-glycoprotein, glypican-4) was frequently associated with adipose triglyceride lipase augmentation, altered glucose homeostasis, resistance to insulin of skeletal muscles, increased cardiomyocyte apoptosis, lowered survival, and weak function of progenitor endothelial cells, which could significantly influence on HF development, as well as end-organ fibrosis and multiple comorbidities. The exact underlying mechanisms for these effects are not fully understood, while they are essential to help develop improved treatment strategies. The aim of the review is to summarize the evidence showing that adipocyte dysfunction may induce the onset of HF and support advance of HF through different biological mechanisms involving inflammation, pericardial, and perivascular adipose tissue accumulation, adverse and electrical cardiac remodeling, and skeletal muscle dysfunction. The unbalancing effects of natriuretic peptides, neprilysin, and components of renin–angiotensin system, as exacerbating cause of altered adipocytokine signaling on myocardium and vasculature, in obesity patients at high risk of HF are disputed. The profile of proinflammatory and anti-inflammatory adipocytokines as promising biomarker for HF risk stratification is discussed in the review.

Adiponectin ameliorates lung injury induced by intermittent hypoxia through inhibition of ROS-associated pulmonary cell apoptosis

PURPOSE

Obstructive sleep apnea hypopnea syndrome has been reported to be associated with pulmonary hypertension (PH). Adiponectin (Ad) has many protective roles in the human body, including its function as an anti-inflammatory and an anti-oxidant, as well as its role in preventing insulin resistance and atherosclerosis. This study aimed to investigate the molecular mechanism of chronic intermittent hypoxia (CIH)-induced pulmonary injury and the protective role of Ad in experimental rats.

METHODS

Thirty male Sprague-Dawley rats were randomly divided into three groups with 10 rats in each group: normal control (NC) group, CIH group, and CIH + Ad group. Rats in the NC group were kept breathing room air for 12 weeks. Rats in the CIH group were intermittently exposed to a hypoxic environment for 8 h/day for 12 weeks. Rats in the CIH + Ad group received 10 μg Ad twice weekly via intravenous injection. After 12 weeks of CIH exposure, we detected the pulmonary function, pulmonary artery pressure, lung histology, pulmonary cell apoptosis, pulmonary artery endothelial cell apoptosis, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) level. We also analyzed expression proteins involved in the mitochondria-, endoplasmic reticulum (ER) stress-, and Fas receptor-associated pulmonary apoptosis pathways, as well as the SIRT3/SOD2 pathway.

RESULTS

CIH exposure for 12 weeks did not lead to abnormal pulmonary function, PH, or pulmonary artery endothelial cell apoptosis. However, we observed a significant increase in the rate of pulmonary cell apoptosis, the expression of proteins involved in mitochondria-, ER stress-, and Fas receptor-associated pulmonary apoptosis pathways, and the generation of ROS in the CIH group compared with the NC group. In contrast, the MMP and protein expressions of SIRT3/SOD2 pathway were significantly decreased in the CIH group compared with the NC group. Ad supplementation in the CIH + Ad group partially improved these changes induced by CIH.

CONCLUSION

Even though CIH did not cause abnormal pulmonary function or PH, early lung injury was detected at the molecular level in rats exposed to CIH. Treatment with Ad ameliorated the pulmonary injury by activating the SIRT3/SOD2 pathway, reducing ROS generation, and inhibiting ROS-associated lung cell apoptosis.

Serum omentin-1 and risk of one-year mortality in patients with ischemic stroke

BACKGROUND

Prior studies suggested that ischemic stroke patients with high omentin-1 concentrations were at a decreased risk of unstable carotid plaque and 3-month poor functional outcome. We aim to evaluate the association between serum omentin-1 and 1-y mortality after ischemic stroke.

METHODS

A total of 303 ischemic stroke patients were prospectively followed up at 1 y. Outcome was defined as death occurred during the follow-up period. A multivariable Cox model was used to evaluate the association between serum omentin-1 concentrations and 1-y mortality among ischemic stroke patients.

RESULTS

From lowest to highest tertile of serum omentin-1, the 1-y cumulative death rate was 12%, 3.7% and 2.1%, respectively (P = 0.006). The hazard ratio (95% confidence interval) of the highest tertile compared with the lowest tertile was 0.19 (0.04-0.88) for mortality after multivariable adjustment (P for trend < 0.01). The net reclassification index and integrated discrimination improvement were significantly improved in predicting 1-y mortality when omentin-1 data was added to the multivariable Cox regression model.

CONCLUSIONS

Among patients with ischemic stroke, high baseline serum omentin-1 was associated with a decreased risk of 1-y mortality. These findings, if confirmed by clinical trials, suggest that increasing omentin-1 concentrations may lower the risk of mortality among ischemic stroke patients.

LINKS BETWEEN RENIN-ANGIOTENSIN SYSTEM GENETIC POLYMORPHISMS AND LEPTIN SECRETION IN OBESE HEART FAILURE PATIENTS

Chronic heart failure (CHF) and obesity are two conditions frequently associated and which, despite all the advances made in their management in the recent years, their prevalence continues to rise. Obese patients present unique challenges in the diagnosis of CHF and also therapeutic particularities. The genetic differences may be a possible explanation for the fact that some people, irrespective of their lifestyle and common classical cardiovascular risk factors, are more susceptible to develop heart failure. Moreover, the adipose tissue, a huge endocrine organ which secretes adipokines, is also a well-established source of all renin-angiotensin-aldosterone system components, being strongly involved in the pathogenesis of CHF. That is why this review will explore the possible links between the RAS genetic polymorphisms and leptin secretion in obese HF patients, trying to bring a more precise understanding of this relationship, which will undoubtedly facilitate a more appropriate treatment of HF in obese patients. We also try to explain the possible incriminated mechanisms, and plausible biological explanations for the relationship between RAS genetic polymorphisms and adipokines secretion in obese heart failure patients.

Beneficial effects of exercise training in heart failure are lost in male diabetic rats

Exercise training has been demonstrated to have beneficial effects in patients with heart failure (HF) or diabetes. However, it is unknown whether diabetic patients with HF will benefit from exercise training. Male Wistar rats were fed either a standard (Sham, n = 53) or high-fat, high-sucrose diet ( n = 66) for 6 mo. After 2 mo of diet, the rats were already diabetic. Rats were then randomly subjected to either myocardial infarction by coronary artery ligation (MI) or sham operation. Two months later, heart failure was documented by echocardiography and animals were randomly subjected to exercise training with treadmill for an additional 8 wk or remained sedentary. At the end, rats were euthanized and tissues were assayed by RT-PCR, immunoblotting, spectrophotometry, and immunohistology. MI induced a similar decrease in ejection fraction in diabetic and lean animals but a higher premature mortality in the diabetic group. Exercise for 8 wk resulted in a higher working power developed by MI animals with diabetes and improved glycaemia but not ejection fraction or pathological phenotype. In contrast, exercise improved the ejection fraction and increased adaptive hypertrophy after MI in the lean group. Trained diabetic rats with MI were nevertheless able to develop cardiomyocyte hypertrophy but without angiogenic responses. Exercise improved stress markers and cardiac energy metabolism in lean but not diabetic-MI rats. Hence, following HF, the benefits of exercise training on cardiac function are blunted in diabetic animals. In conclusion, exercise training only improved the myocardial profile of infarcted lean rats fed the standard diet. NEW & NOTEWORTHY Exercise training is beneficial in patients with heart failure (HF) or diabetes. However, less is known of the possible benefit of exercise training for HF patients with diabetes. Using a rat model where both diabetes and MI had been induced, we showed that 2 mo after MI, 8 wk of exercise training failed to improve cardiac function and metabolism in diabetic animals in contrast to lean animals.

Serum adiponectin and protein-energy wasting in predialysis chronic kidney disease

OBJECTIVE

Adiponectin (ADPN) has antiatherogenic, anti-inflammatory, and insulin-sensitizing effects. Serum ADPN levels are increased in patients with chronic kidney diseases (CKD), and higher ADPN is paradoxically a predictor of mortality in these patients. The aim of this study was to determine the association between serum ADPN levels and protein-energy wasting (PEW) in predialysis CKD.

METHOD

We examined serum ADPN concentrations and PEW in 1303 patients from the KNOW-CKD (KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease) study. PEW was defined as the presence of three or more of the following four indicators: serum albumin <3.8 g/dL, body mass index <23 kg/m², urine creatinine excretion (UCE) below the lower quartile, and daily dietary protein intake <0.6 g/kg. We analyzed the association between PEW and ADPN using a multivariate regression model after adjustment for socioeconomic factors, comorbidities, and laboratory findings.

RESULTS

Among 1303 predialysis CKD patients, 72 (5.5%) had PEW. In multivariate logistic regression analysis, higher ADPN level was associated with PEW (odds ratio, 1.04; 95% confidence interval [CI], 1.01-1.08 by 1 μg/mL ADPN). The highest ADPN quartile was associated with PEW in comparison with the lowest quartile (odds ratio, 10.54; 95% CI, 1.28-86.74). In multiple linear regression with PEW indicators, ADPN was more strongly associated with UCE (β = -2.21; 95% CI, -4.13 to -0.28; R² = 0.67).

CONCLUSION

High ADPN is independently associated with PEW. Among PEW indicators, serum ADPN is closely associated with UCE as an indirect measure of muscle mass.

Adiponectin resistance in skeletal muscle: pathophysiological implications in chronic heart failure

Skeletal muscle wasting is a common complication of chronic heart failure (CHF) and linked to poor patient prognosis. In recent years, adiponectin was postulated to be centrally involved in CHF-associated metabolic failure and muscle wasting. This review discusses current knowledge on the role of adiponectin in CHF. Particular emphasis will be given to the complex interaction mechanisms and the intracellular pathways underlying adiponectin resistance in skeletal muscle of CHF patients. In this review, we propose that the resistance process is multifactorial, integrating abnormalities emanating from insulin signalling, mitochondrial biogenesis, and ceramide metabolism.

Tumor necrosis factor-α impairs adiponectin signalling, mitochondrial biogenesis, and myogenesis in primary human myotubes cultures

Skeletal muscle metabolic changes are common in patients with chronic heart failure (HF). Previously, we demonstrated a functional skeletal muscle adiponectin resistance in HF patients with reduced left ventricular ejection fraction (HFrEF). We aimed to examine the impact of adiponectin receptor 1 (AdipoR1) deficiency and TNF-α treatment on adiponectin signaling, proliferative capacity, myogenic differentiation, and mitochondrial biogenesis in primary human skeletal muscle cells. Primary cultures of myoblasts and myotubes were initiated from the musculus vastus lateralis of 10 HFrEF patients (left ventricular ejection fraction; 31.30 ± 2.89%) and 10 age- and gender-matched healthy controls. Healthy control cultures were transfected with siAdipoR1 and/or exposed to TNF-α (10 ng/ml; 72 h). Primary cultures from HFrEF patients preserved the features of adiponectin resistance in vivo. AdipoR1 mRNA was negatively correlated with time to reach maximal cell index (r = -0.7319, P = 0.003). SiRNA-mediated AdipoR1 silencing reduced pAMPK (P < 0.01), AMPK activation (P = 0.046), and myoblast proliferation rate (xCELLigence Real-Time Cellular Analysis; P < 0.0001). Moreover, TNF-α decreased the mRNA expression of genes involved in glucose (APPL1, P = 0.0002; AMPK, P = 0.021), lipid (PPARα, P = 0.025; ACADM, P = 0.003), and mitochondrial (FOXO3, P = 0.018) metabolism, impaired myogenesis (MyoD1, P = 0.053; myogenin, P = 0.048) and polarized cytokine secretion toward a growth-promoting phenotype (IL-10, IL-1β, IFN-γ, P < 0.05 for all; Meso Scale Discovery Technology). Major features of adiponectin resistance are retained in primary cultures from the skeletal muscle of HFrEF patients. In addition, our results suggest that an increased inflammatory constitution contributes to adiponectin resistance and confers alterations in skeletal muscle differentiation, growth, and function.

CTRP3 promotes energy production by inducing mitochondrial ROS and up-expression of PGC-1α in vascular smooth muscle cells

C1q/tumor necrosis factor-related protein-3 (CTRP3) is an adipokine with modulation effects on metabolism and inflammation. Adenosine triphosphate (ATP) exerts multiple biological effects in vascular smooth muscle cells (VSMCs) and energy imbalance is involved in vascular diseases. This study aimed to explore the effect of CTRP3 on energy production and its underlying mechanism in VSMCs. Our results indicated that exogenous CTRP3 increased ATP synthesis and the protein expression of oxidative phosphorylation (OXPHOS)-related molecules, including peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α, sirtuin-3 (SIRT3), complex I, II, III, and V in cultured VSMCs. Depletion of endogenous CTRP3 by small interfering RNA (siRNA) reduced ATP synthesis and the expression of those molecules. PGC-1α knockdown abrogated CTRP3-induced ATP production and OXPHOS-related protein expression. Furthermore, CTRP3 increased mitochondrial reactive oxygen species (ROS) production and mitochondrial membrane potential level. Pretreatment with N-acetyl-L-cysteine, a reactive oxygen species scavenger, and cyanidem-chlorophenylhydrazone, an uncoupler of OXPHOS, suppressed CTRP3-induced ROS production, PGC-1α expression and ATP synthesis. In conclusion, CTRP3 modulates mitochondrial energy production through targets of ROS and PGC-1α in VSMCs.

Essential roles of insulin, AMPK signaling and lysyl and prolyl hydroxylases in the biosynthesis and multimerization of adiponectin

Post-translational modifications (PTMs) of the adiponectin molecule are essential for its full bioactivity, and defects in PTMs leading to its defective production and multimerization have been linked to the mechanisms of insulin resistance, obesity, and type-2 diabetes. Here we observed that, in differentiated 3T3-L1 adipocytes, decreased insulin signaling caused by blocking of insulin receptors (InsR) with an anti-InsR blocking antibody, increased rates of adiponectin secretion, whereas concomitant elevations in insulin levels counteracted this effect. Adenosine monophosphate-activated protein kinase (AMPK) signaling regulated adiponectin production by modulating the expression of adiponectin receptors, the secretion of adiponectin, and eventually the expression of adiponectin itself. We found that lysyl hydroxylases (LHs) and prolyl hydroxylases (PHs) were expressed in white-adipose tissue of ob/ob mice, wherein LH3 levels were increased compared with controls. In differentiated 3T3-L1 adipocytes, both non-specific inhibition of LHs and PHs by dipyridyl, and specific inhibition of LHs by minoxidil and of P4H with ethyl-3,4-dihydroxybenzoate, caused significant suppression of adiponectin production, more particularly of the higher-order isoforms. Transient gene knock-down of LH3 (Plod3) caused a suppressive effect, especially on the high molecular-weight (HMW) isoforms. These data indicate that PHs and LHs are both required for physiological adiponectin production and in particular are essential for the formation/secretion of the HMW isoforms.

Adiponectin protects rat heart from left ventricular remodeling induced by chronic intermittent hypoxia via inhibition of TGF-β/smad2/3 pathway

OBJECTIVE

Obstructive sleep apnea syndrome (OSAS) is associated with many cardiovascular disorders. Chronic intermittent hypoxia (CIH) is the primary player in OSAS of the many associated factors. This study was in order to investigate the effects of the Adiponectin (Ad) on left ventricular remodeling induced by CIH.

METHODS

Forty-five rats were randomly divided into three groups: normal control (NC) group, CIH group and CIH plus Ad supplemented (CIH + Ad) group. After 35 days' CIH exposure, masson analysis was used to detect the left ventricular fibrosis and western blot was used to measure the protein expression of collagen I, collagen III and TGF-β/smad2/3 pathway. Gene analysis by RT-PCR was used to study the MMP2 and TIMP2.

RESULTS

After CIH exposure, the fibrosis of left ventricular in CIH group was significantly remarkable than that in both NC and CIH + Ad groups (P<0.05), although statistical difference existed between NC and CIH + Ad groups (P<0.05). In addition, the protein expression of collagen I as well as collagen III and the ratio of mRNA levels of MMP2/TIMP2 were the highest in CIH group but the lowest in NC group, with CIH + Ad group in between. There was a significant difference among three groups (all P<0.05). The TGF-β/smad2/3 pathway was activated obviously in CIH group, but less noticeably in CIH + Ad group (P<0.05) with a significant difference in the two groups.

CONCLUSIONS

The present study showed that Ad could ameliorate the left ventricular remodeling induced by CIH via inhibition of the expression of TGF-β/smad2/3 pathway.

Association of adiponectin with peripheral muscle status in elderly patients with heart failure

BACKGROUND

Reduced peripheral muscle mass was demonstrated in patients with chronic heart failure (HF). Adipokines may have potent metabolic effects on skeletal muscle. The associations between adipokines, peripheral muscle mass, and muscle function have been poorly investigated in patients with HF.

METHODS

We measured markers of fat and bone metabolism (adiponectin, leptin, 25-hydroxy vitamin D, parathyroid hormone, osteoprotegerin, RANKL), N-terminal pro B-type natriuretic peptide (NT-pro-BNP) in 73 non-cachectic, non-diabetic, male patients with chronic HF (age: 68 ± 7 years, New York Heart Association class II/III: 76/26%, left ventricular ejection fraction 29 ± 8%) and 20 healthy controls of similar age. Lean mass as a measure of skeletal muscle mass was measured by dual energy X-ray absorptiometry (DEXA), while muscle strength was assessed by hand grip strength measured by Jamar dynamometer.

RESULTS

Serum levels of adiponectin, parathyroid hormone, osteoprotegerin, RANKL, and NT-pro-BNP were elevated in patients with chronic HF compared to healthy controls (all p<0.0001), while no difference in serum levels of leptin, testosterone or SHBG was noted. Levels of 25-hydroxy vitamin D were reduced (p=0.002) in HF group. Peripheral lean mass and hand grip strength were reduced in patients with HF compared to healthy subjects (p=0.006 and p<0.0001, respectively). Using backward selection multivariable regression, serum levels of increased adiponectin remained significantly associated with reduced arm lean mass and muscle strength.

CONCLUSIONS

Our findings may indicate a cross-sectional metabolic association of increased serum adiponectin with reduced peripheral muscle mass and muscle strength in non-cachectic, non-diabetic, elderly HF patients.

Adiponectin levels are elevated in patients with pulmonary arterial hypertension

BACKGROUND

In addition to insulin-sensitizing effects, adiponectin influences several mechanisms involved in pulmonary arterial hypertension (PAH) pathobiology. Insulin resistance has been associated with PAH, and elevated adiponectin levels have been described in left heart failure (HF) as a response to the increased metabolic stress. No studies have been performed in right HF or PAH patients.

HYPOTHESIS

Compared to healthy controls, PAH patients have a different plasma adipocytokine profile, higher insulin resistance, and higher inflammatory systemic activation.

METHODS

A case-control study was conducted in PAH patients individually matched for sex, age, and body mass index. We characterized the clinical features, functional status (6-minute walking test), and hemodynamic profile of cases (n=25). We measured insulin resistance (homeostasis model assessment and high-density lipoprotein/triglycerides ratio), inflammatory systemic activation (high-sensitivity C-reactive protein), and plasma adipocytokine profile (adiponectin, leptin, visfatin, and resistin) in cases and controls.

RESULTS

PAH patients had significantly higher adiponectin levels than controls (12.4±6.9 vs 8.1±4.5 µg/mL; P<0.05) and higher high-sensitivity C-reactive protein (2.96±3.2 vs 1.08±1.1; P<0.05). No statistically significant differences were found in plasma levels of leptin, visfatin, and resistin between groups.

CONCLUSIONS

Adiponectin levels are increased in PAH patients compared to controls. Further studies are needed to study the potential role of adiponectin as a PAH biomarker.