Impact of Salusin-α and -β on Human Macrophage Foam Cell Formation and Coronary Atherosclerosis

The relationship between serum salusins levels and atherosclerosis, endothelial dysfunction and cardiac morphology in autosomal dominant polycystic kidney disease

PURPOSE

We aimed to assess the associations between serum salusins levels and atherosclerosis, endothelial dysfunction and cardiac morphology in autosomal dominant polycystic kidney disease (ADPKD).

METHODS

This study comprised 83 patients with ADPKD, and 53 healthy individuals. Salusin α and β levels were measured by ELISA. Echocardiography, flow-mediated vasodilatation, and carotid artery intima-media thickness measurements were conducted.

RESULTS

Serum salusin α levels were significantly lower and the salusin β/α ratio was significantly higher in the patient group compared to Controls [2.64 (1.83-3.30) pg/mL vs. 3.20 (2.55-7.87) pg/mL, P = 0.002 and 2.81 (2.30-3.54) vs. 2.64 (2.02-3.18), P = 0.041, respectively]. Patients were further categorized into two groups: Group 1 (eGFR ≥ 60 mL/min/1.73 m2) and Group 2 (eGFR = 59-15 mL/min/1.73 m2). The salusin α level was 2.31 (1.73-3.24) pg/mL in Group 2 and 2.72 (1.94-3.32) pg/mL in Group 1. In the correlation analysis performed in Group 2, there was a statistically significant negative correlation between salusin α and left ventricular mass (LVM) and LVM index (P = 0.019, P = 0.015, respectively), as well as a statistically significant positive correlation between salusin β/α ratio and LVM (P = 0.004) and LVM index (P = 0.025). In Group 1, a statistically significant positive correlation was detected between proteinuria and salusin β (P = 0.036).

CONCLUSION

In patients with ADPKD, salusin α was found to be significantly lower, while salusin β/α ratio was found to be significantly higher compared to healthy individuals. Low salusin α levels and high salusin β/α ratio were associated with LVM in advanced stages of ADPKD and salusin β was associated with proteinuria in early stage of ADPKD patients.

Salusin-α attenuates lipid accumulation of C57BL/6 mice with Non-alcoholic fatty liver

With the development of society and economy, Non-alcoholic fatty liver disease (NAFLD) has gradually affected people's health. It is very important to find an effective treatment for NAFLD. Salusin-α is a kind of cardiovascular active peptide that can reduce blood pressure and slow down the heart rate. Studies have shown that Salusin-α can inhibit the development of atherosclerosis by regulating lipid metabolism. However, whether Salusin-α can inhibit the lipid accumulation of C57BL/6 mice with NAFLD has not been reported. Our study found that Salusin-α ameliorated lipid accumulation of NAFLD mice. Salusin-α has a good prospect in the treatment of NAFLD.

Evaluation of salusin-β in paediatric patients with chronic kidney disease or hypertension

PURPOSE

Salusins are newly identified endogenous peptides implicated in the atherosclerotic process. Salusin-β, in particular, is recognized for its proatherogenic role. Given that atherosclerosis can commence in childhood, salusin-β holds promise as a potential biomarker for cardiovascular risk assessment. The objective of our study was to investigate salusin-β levels in children with early stages of chronic kidney disease (CKD) or hypertension (HTN), and compare them to healthy controls. Furthermore, we aimed to evaluate its association with obesity and pulse wave velocity (PWV), the latter being a well-established marker for determining arterial elasticity.

MATERIALS AND METHODS

This cross-sectional study involved 96 paediatric patients, including 46 with CKD and 50 with HTN, as well as 33 healthy controls. Anthropometric measurements, PWV assessments, serum salusin-β values, and basic laboratory investigations were conducted for all participants.

RESULTS

Salusin-β levels were found to be elevated in patients with CKD (p ​= ​0.014), but not in patients with HTN when compared to healthy controls. When correlating salusin-β levels with PWV, a significant but weak correlation was observed (r ​= ​0.211, p ​= ​0.020).

CONCLUSIONS

Salusin-β levels were elevated in paediatric patients with CKD. Additionally, salusin-β levels correlated significantly with PWV. Obesity played a smaller role in these correlations, with significant correlations observed only after combining cardiovascular risk factors revealing certain associations between salusin-β levels and some cardiovascular variables, but with inconclusive findings and, in some instances, even contrary to anticipated outcomes.

Modification macrophage to foam cells in atherosclerosis disease: some factors stimulate or inhibit this process

Background

Atherosclerosis is an arterial blood vessel disease that begins and progresses by turning macrophages into foam cells. Uptake of oxidized low-density lipoprotein (ox-LDL), cholesterol esterification and cholesterol efflux are the most important factors in the formation of foam cells and play an important role in atherosclerosis.

Methods

The present study is based on the data obtained from the PubMed database (1961-2024) using the MeSH search terms "Atherosclerosis", "Macrophages" and "Foam cells". Reviews for writing the main text and non-English-language articles were excluded.

Result

The interaction between ox-LDL and macrophages plays an important role in plaque initiation and promotion processes. Macrophages abnormally digest ox-LDL, resulting in the accumulation of lipids and formation of foam cells. This is an important step in the development of atherosclerosis. Also, several other factors such as inflammatory factors, growth factors, hormones, etc. can play an important role in the development of atherosclerotic lesions or counteract it by affecting the formation of foam cells.

Conclusion

Several factors can affect the progression of atherosclerosis by affecting macrophage activity or its conversion to foam cells. Also, some of these factors play a protective role against the development and atherosclerosis progression. In this paper, we reviewed some of these factors and their effect on atherosclerosis.

Serum salusin-α and -β levels in patients with parkinson's disease

BACKGROUND

The etiology of Parkinson's disease (PD) is not well known and there is increasing evidence that oxidative stress also plays an important role in its pathogenesis. Salusins alpha (salusin-α) and beta (salusin-β) affect the central nervous system, vasculature, and kidneys to increase the inflammatory response in endothelial cells, stimulate oxidative stress, and increase monocyte-endothelial adhesion. Neuroinflammation and oxidative stress play roles in the etiopathogenesis of PD.

PURPOSE

To investigate whether salusin-α and -β are related to PD and whether they are correlated with the development of atherosclerosis, body mass index, disease duration, and the Parkinson's Hoehn and Yahr stage.

RESULTS

The low-density lipoprotein cholesterol (LDL-C), total cholesterol, and salusin-β levels were significantly lower and age was significantly higher in Parkinson patients compared to healthy controls (ρ < 0.005). We found a negative linear correlation between salusin-β and the Hoehn and Yahr stage (ρ < 0.001, r = -0.515) in the patients.

CONCLUSIONS

There was a relationship between salusin-β and PD and a correlation between the salusin-β levels and Parkinson's stage. A possible underlying disease mechanism is an increase in oxidative stress and decrease in neuroprotective effects due to low salusin-β levels. Therefore, the effects of salusin-β in treating Parkinson disease should be evaluated. Further studies are needed to understand the effects of salusin-β treatment on preventing or slowing the course of PD.

Targeting VCAM-1: a therapeutic opportunity for vascular damage

INTRODUCTION

The vascular cell adhesion molecule (VCAM-1) is a transmembrane sialoglycoprotein detected in activated endothelial and vascular smooth muscle cells involved in the adhesion and transmigration of inflammatory cells into damaged tissue. Widely used as a pro-inflammatory marker, its potential role as a targeting molecule has not been thoroughly explored.

AREAS COVERED

We discuss the current evidence supporting the potential targeting of VCAM-1 in atherosclerosis, diabetes, hypertension and ischemia/reperfusion injury.

EXPERT OPINION

There is emerging evidence that VCAM-1 is more than a biomarker and may be a promising therapeutic target for vascular diseases. While there are neutralizing antibodies that allow preclinical research, the development of pharmacological tools to activate or inhibit this protein are required to thoroughly assess its therapeutic potential.

Salusins: advance in cardiovascular disease research

Salusins are discovered in 2003 and divided into salusin-α and salusin-β, which are bioactive peptides with hemodynamic and mitotic activity and mainly distributed in plasma, urine, endocrine glands and kidneys. A large number of studies have shown that salusins can regulate lipid metabolism, inflammatory response and vascular proliferation. Despite the profound and diverse physiological properties of salusins, the exact mechanism of their cardiovascular effects remains to be determined. The potential mechanisms of action of salusins in cardiovascular-related diseases such as atherosclerosis, hypertension, heart failure, myocardial infarction and myocarditis, and their use as biomarkers of cardiovascular disease are discussed. This review aims to provide a new strategy for the diagnosis and prevention of clinical cardiovascular diseases.

The Clinical Significance of Salusins in Systemic Sclerosis-A Cross-Sectional Study

Background: Systemic sclerosis (SSc) is a connective tissue disease manifesting with progressive fibrosis of the skin and internal organs. Its pathogenesis is strictly associated with vascular disfunction and damage. Salusin-α and salusin-β, endogenous peptides regulating secretion of pro-inflammatory cytokines and vascular smooth muscle proliferation, may potentially play a role in SSc pathogenesis. Objectives: The aim of this study was to assess the concentration of salusins in sera of patients with SSc and healthy controls and to evaluate correlations between the salusins levels and selected clinical parameters within the study group. Materials and methods: 48 patients with SSc (44 women; mean age, 56.4, standard deviation, 11.4) and 25 adult healthy volunteers (25 women; mean age, 55.2, standard deviation, 11.2) were enrolled. All patients with SSc were treated with vasodilators and twenty-seven of them (56%) also received immunosuppressive therapy. Results: Circulating salusin-α was significantly elevated in patients with SSc in comparison to healthy controls (U = 350.5, p = 0.004). Patients with SSc receiving immunosuppression had higher serum salusin-α concentrations compared with those without immunosuppressive therapy (U = 176.0, p = 0.026). No correlation was observed between salusins concentrations and skin or internal organ involvement parameters. Conclusions: Salusin-α, a bioactive peptide mitigating the endothelial disfunction, was elevated in patients with systemic sclerosis receiving vasodilators and immunosuppressants. Increased salusin-α concertation may be associated with the initiation of atheroprotective processes in patients with SSc managed pharmacologically, which requires verification in future studies.

Inflammatory biomarkers, angiogenesis and lymphangiogenesis in epicardial adipose tissue correlate with coronary artery disease

In this study, we explored the relationship between inflammatory adipokine levels and coronary artery disease (CAD). We collected subcutaneous adipose tissues(SAT), pericardial adipose tissues(PAT), and epicardial adipose tissues (EAT) and serum samples from 26 inpatients with CAD undergone coronary artery bypass grafting and 20 control inpatients without CAD. Serum inflammatory adipokines were measured by ELISA. Quantitative real-time PCR and western blot were used to measure gene and protein expression. Adipocyte morphology was assessed by H&E staining. Immunohistochemistry and immunofluorescence were used to measure endothelial and inflammatory markers. Serum pro- and anti-inflammatory adipokine levels were higher and lower, respectively, in the CAD group than those in the control group (P < 0.05). In CAD, the pro-inflammatory adipokine levels via ELISA in EAT and PAT were elevated. Pro-inflammatory adipokine mRNA expression was increased, while anti-inflammatory adipokine mRNA expression decreased, in CAD relative to NCAD in EAT and PAT rather than SAT. In EAT, adipocyte area and macrophage-specific staining were lower, while lymphatic vessel marker expression was higher in CAD. Additionally, the endothelial marker expression in EAT was higher than PAT in CAD. The three tissue types had different blood vessel amounts in CAD. The regulation and imbalance expression of the novel biomarkers, including inflammatory adipokine, macrophage infiltration, angiogenesis, and lymphangiogenesis in EAT and PAT, may be related to the pathogenesis of CAD. The serum levels of inflammatory adipokines may correlate to CAD, which requires large sample size studies to get further validation before clinic practice.

A New Insight Into Pathophysiological Mechanism of Abdominal Aortic Aneurysm With Novel Parameters Salusin-β and Arterial Stiffness

BACKGROUND

Abdominal aortic aneurysm (AAA) has risk factors similar to those of atherosclerosis. Salusin-β and arterial stiffness are novel parameters that have been shown to predict atherosclerosis and related cardiovascular disorders. However, their predictive value for detecting AAA remains unclear.

METHODS

Forty-eight patients with AAA and 47 age- and sex-matched participants without AAA were enrolled in the study. Arterial stiffness parameters were obtained via an oscillometric Mobil-O-Graph PWA Monitor device (IEM GmbH) with integrated ARCSolver software (Australian Institute of Technology). Plasma salusin-β levels were analyzed using an enzyme-linked immunosorbent assay reagent kit (Abbkine, Inc). The measured salusin-β levels and arterial stiffness parameters of the AAA and control groups were compared.

RESULTS

Salusin-β levels were significantly lower in patients with AAA (P = .014). There was a significant negative correlation between salusin-β levels and abdominal aorta diameter. No significant difference was detected between AAA and control groups in terms of arterial stiffness parameters (P > .05). In backward multiple regression analysis, the presence of AAA, platelet count, and augmentation index were found to be independent predictors of salusin-β levels (P = .006 and P = .023, respectively).

CONCLUSION

Arterial stiffness parameters were not found to be associated with AAA. Contrary to previous results regarding atherosclerosis and related cardiovascular disorders, salusin-β levels were found to be lower in patients with AAA. Although AAA is thought to have similar risk factors as atherosclerosis, the exact pathophysiologic mechanism remains unclear.

Serum salusin-α and salusin-β levels in patients with psoriatic arthritis

INTRODUCTION

Psoriatic arthritis (PsA) is a chronic inflammatory disease characterized by skin lesions and joint involvement. Salusin-α and salusin-β are two new bioactive molecules. It is reported that salusins may have role in regulation of the immune system and inflammation. The aim of our study was to evaluate the serum salusin-α and salusin-β levels in PsA patients and to establish the possible relationship with the disease features.

MATERIAL AND METHODS

Our study included 40 PsA patients who fulfilled the CASPAR criteria and 40 healthy volunteers. Demographic, clinical, laboratory and radiological data and disease activity indices (PASI, BASDAI, BASFI, HAQ) were recorded in all patients. The enzyme-linked immunosorbent assay (ELISA) method was used to measure serum salusin-α and salusin-β levels.

RESULTS

The demographic data were as follows: 13 patients (32.5%) were males and 27 (67.5%) were female, mean age was 48.5 years and mean disease duration was 2.4 years. Patients' history was taken and clinical assessment was performed; 20 (50%) patients had a family history, 18 (45%) patients were smoker, 19 (47.5%) patients had HLA-B27 positivity, 33 (82.5%) had sacroiliitis, 36 (90%) had enthesitis, 23 (57.5%) had distal interphalangeal (DIP) joint and nail involvement, 26 (65%) had wrist involvement, and 11 (27.5%) had ankle involvement. Laboratory data of the patients were recorded; 20 (50%) patients had elevated CRP level and 25 (62.5%) patients had an elevated ESR level. The study results showed that PsA patients had an elevated serum salusin-α level when compared with the control group (p = 0.004). The association between serum salusin-α level and ankle arthritis was found (p = 0.04). Serum levels of salusin-β were similar in PsA patients and controls both (p = 0.285).

CONCLUSIONS

We found elevated serum salusin-α in PsA patients while the serum salusin-β levels were normal. Salusin-α may have a possible role in disease pathogenesis and it may be use as a reliable biomarker in PsA patients. Multicenter prospective studies are needed in this regard.

A New Marker for Determining Cardiovascular Risk: Salusin Alpha

Background and objective Prevention of atherosclerotic cardiovascular diseases (ASCVD) is possible with early recognition of individuals at risk. Salusin alpha is an endogenous bioactive peptide with anti-atherogenic properties. We aimed to reveal the relationship between salusin alpha levels and cardiovascular (CV) risk using the Systematic COronary Risk Estimation 2 (SCORE2) and Pooled Cohort Equation (PCE) algorithms. Methods A total of 137 asymptomatic outpatients were included in the study. The participants were divided into four quartile groups according to the distribution of salusin alpha levels: Q1 (n = 34), Q2 (n = 35), Q3 (n = 34), and Q4 (n = 34). The relationships of salusin alpha with cardiovascular risk scores and groups were investigated. Results The means of SCORE2 and PCE risk scores (11.24 ± 1.24 and 13.30 ± 1.71, respectively; p < 0.001 for both), baseline scores in the presence of SCORE2 and PCE optimal risk factors (4.82 ± 0.71 (p = 0.034); 4.20 ± 0.77 (p = 0.010)), and means of Δ SCORE2 and Δ PCE risk score (6.41 ± 0.67 and 9.10 ± 1.10, respectively; p < 0.001 for both) were significantly higher in the Q1 group. The SCORE2 "very high" cardiovascular (CV) risk group was significantly represented in the Q1 group (n = 17 (50%)), while the "low-moderate" risk group was more heavily represented in the Q4 group (n = 15 (44.1%)) (p < 0.001). The PCE "high" CV risk group was significantly represented in the Q1 group (n = 9 (26.5%)), while the "low" risk group was more intensely represented in the Q4 group (n = 20 (58.8%)) (p < 0.001). Salusin alpha had a significantly negative moderate correlation with SCORE2 and PCE risk scores. As a result of receiver operating characteristic (ROC) analysis, it was found that salusin alpha had significant diagnostic power in the prediction of CV risk groups determined by SCORE2 and PCE risk scores. Salusin alpha was observed to be a risk-reducing factor in SCORE2 and PCE CV risk groups (odds ratio (OR) (95% confidence interval (CI)): 0.989 (0.982-0.997) (p = 0.002) and OR (95% CI): 0.988 (0.978-0.998) (p = 0.009) respectively). Conclusion Salusin alpha has a negative correlation with SCORE2 and PCE risk scores. It has significant diagnostic power in the prediction of CV risk groups and is an independent variable that has a risk-reducing effect in the distribution of risk groups.

Salusin-β, a TOR2A gene product, promotes proliferation, migration, fibrosis, and calcification of smooth muscle cells and accelerates the imbalance of vasomotor function and vascular remodeling in monocrotaline-induced pulmonary hypertensive rats

Purpose: The hyper-proliferation, promoted migration, fibrosis, and calcification of pulmonary arterial smooth muscle cells (PASMCs) play critical roles in pulmonary artery (PA) continuous contraction and vascular remodeling, leading to elevated pulmonary arterial resistance and pulmonary hypertension (PH). In this study, we sought to ascertain the effects of a TOR2A gene product, salusin-β, on PASMCs’ proliferation, migration, fibrosis, calcification, and the imbalance of vasomotor function as well as pulmonary vascular remodeling in monocrotaline (MCT)-induced PH rats and their underlying mechanisms.

Methods: Knockdown or overexpression of salusin-β in rats or PASMCs was performed through tail vein injection or cell transfection of virus. The right ventricular systolic pressure (RVSP) of the rat was measured by right ventricle catheterization. Sodium nitroprusside (SNP) or acetylcholine (ACh)-induced dose-dependent relaxation was used to evaluate the vasodilatation function. Primary PASMCs were isolated from the PAs of control and PH rats.

Results: The salusin-β protein expressions were significantly increased in PAs and PASMCs isolated from PH rats compared with control rats. Knockdown of salusin-β in rats decreased high K⁺ solution-induced contraction, RVSP and RV hypertrophy index, improved SNP or ACh-induced vascular relaxation of PAs, and relieved vascular remodeling and calcification of PAs from PH rats. Silencing salusin-β in PASMCs isolated from PH rats alleviated the proliferation, migration, fibrosis, and calcification, as well as the NAD(P)H oxidase activity and reactive oxygen species (ROS) level. Overexpression of salusin-β exerted the opposite effects on vasomotor function and vascular remodeling, and PASMCs proliferation, migration, fibrosis and calcification.

Conclusion: Increased salusin-β activity in PAs from PH rats contributes to PASMCs proliferation, migration, fibrosis, and calcification, leading to the imbalance of vascular contraction and relaxation and vascular remodeling through stimulating the production of NAD(P)H oxidase derived ROS.

Toll-Like Receptor 3 in Cardiovascular Diseases

Toll-like receptor 3 (TLR3) is an important member of the innate immune response receptor toll-like receptors (TLRs) family, which plays a vital role in regulating immune response, promoting the maturation and differentiation of immune cells, and participating in the response of pro-inflammatory factors. TLR3 is activated by pathogen-associated molecular patterns and damage-associated molecular patterns, which support the pathophysiology of many diseases related to inflammation. An increasing number of studies have confirmed that TLR3, as a crucial medium of innate immunity, participates in the occurrence and development of cardiovascular diseases (CVDs) by regulating the transcription and translation of various cytokines, thus affecting the structure and physiological function of resident cells in the cardiovascular system, including vascular endothelial cells, vascular smooth muscle cells, cardiomyocytes, fibroblasts and macrophages. The dysfunction and structural damage of vascular endothelial cells and proliferation of vascular smooth muscle cells are the key factors in the occurrence of vascular diseases such as pulmonary arterial hypertension, atherosclerosis, myocardial hypertrophy, myocardial infarction, ischaemia/reperfusion injury, and heart failure. Meanwhile, cardiomyocytes, fibroblasts, and macrophages are involved in the development of CVDs. Therefore, the purpose of this review was to explore the latest research published on TLR3 in CVDs and discuss current understanding of potential mechanisms by which TLR3 contributes to CVDs. Even though TLR3 is a developing area, it has strong treatment potential as an immunomodulator and deserves further study for clinical translation.

Current Knowledge of Selected Cardiovascular Biomarkers in Pediatrics: Kidney Injury Molecule-1, Salusin-α and -β, Uromodulin, and Adropin

Cardiovascular diseases are the leading cause of morbidity and mortality in the modern world. Their common denominator is atherosclerosis, a process beginning in childhood. In pediatrics, the aim of preventive measures is to recognize children and adolescents at risk for accelerated atherosclerosis and possible premature cardiovascular events in adulthood. Several diagnostic procedures and biomarkers are available for cardiovascular risk assessment in adults. However, reliable markers in pediatrics are still insufficiently studied. In this contribution, we discuss five potential biomarkers of particular interest: kidney injury molecule-1, salusin-α and -β, uromodulin, and adropin. Studies regarding the pediatric population are scarce, but they support the evidence from studies in the adult population. These markers might entail both a prognostic and a therapeutic interest.

The role of adropin, salusin-α, netrin-1, and nesfatin-1 in endometriosis and their association with insulin resistance

Objective:

The pathogenesis of endometriosis has not been clearly explained. Inflammatory factors of ectopic implantation and the growth of ectopic endometrial cells have been subjects of major interest. The number of studies evaluating salusin-α and nesfatin-1 markers in patients with endometriosis is limited. No studies have evaluated the levels of anti-inflammatory markers for adropin and netrin-1 in patients with endometriosis. This study investigates how some important inflammatory regulatory markers in the inflammatory process affect the pathogenesis of endometriosis and determines whether any relationship exists between serum levels of these parameters and endometriosis and insulin resistance.

Materials and Methods:

This prospective study included 73 patients with endometriosis diagnosed histopathologically after laparoscopic surgery and 75 healthy controls. Serum adropin, salusin-α, netrin-1, and nesfatin-1 levels and homeostatic model assessment of insulin resistance (HOMA-IR) values of the participants were measured.

Results:

The endometriosis group had significantly lower nesfatin-1 levels than the control group (3.0±0.53 vs 9.5±0.94, p=0.005). Between the patient and control groups, there was no difference regarding serum adropin, salusin-α, and netrin-1 levels (p=0.36, p=0.34, p=0.75, respectively). Nesfatin-1 had a significant positive correlation with adropin, salusin-α, and netrin-1 (r=0.563, p<0.01; r=0.738, p<0.01; r=0.700, p<0.01, respectively), but had a negative correlation with fasting blood glucose (r=−0.343, p<0.05). HOMA-IR values were comparable between both groups.

Conclusion:

The lower nesfatin-1 levels leading to increased inflammatory pathway activity in patients with endometriosis might play a role in endometriosis pathogenesis. Without causing systemic insulin resistance, decreased nesfatin-1 might contribute to endometriosis pathogenesis locally by leading to the reduced insulin susceptibility of endometriosis cells.

Understanding the Stony Bridge between Osteoporosis and Vascular Calcification: Impact of the FGF23/Klotho axis

A relationship between osteoporosis (OP) and vascular calcification (VC) is now proposed. There are common mechanisms underlying the regulation of them. Fibroblast growth factor- (FGF-) 23 and Klotho are hormones associated with the metabolic axis of osteovascular metabolism. Most recently, it was suggested that the FGF23-klotho axis is associated with increasing incidence of fractures and is potentially involved in the progression of the aortic-brachial stiffness ratio. Herein, we discussed the potential role of the FGF23/Klotho axis in the pathophysiology of OP and VC. We want to provide an update review in order to allow a better understanding of the potential role of the FGF23/Klotho axis in comorbidity of OP and VC. We believe that a better understanding of the relationship between both entities can help in proposing new therapeutic targets for reducing the increasing prevalence of OP and VC in the aging population.

Knockdown of Salusin-β Improves Cardiovascular Function in Myocardial Infarction-Induced Chronic Heart Failure Rats

Salusin-β is a biologically active peptide with 20 amino acids that exerts several cardiovascular activity-regulating effects, such as regulating vascular endothelial function and the proliferation of vascular smooth muscle cells. However, the regulatory effects of salusin-β in myocardial infarction-induced chronic heart failure (CHF) are still unknown. The current study is aimed at investigating the effects of silencing salusin-β on endothelial function, cardiac function, vascular and myocardial remodeling, and its underlying signaling pathways in CHF rats induced by coronary artery ligation. CHF and sham-operated (Sham) rats were subjected to tail vein injection of adenoviral vectors encoding salusin-β shRNA or a control-shRNA. The coronary artery (CA), pulmonary artery (PA), and mesenteric artery (MA) were isolated from rats, and isometric tension measurements of arteries were performed. Compared with Sham rats, the plasma salusin-β, leptin and visfatin levels and the salusin-β protein expression levels of CA, PA, and MA were increased, while the acetylcholine- (ACh-) induced endothelium-dependent vascular relaxation of CA, PA, and MA was attenuated significantly in CHF rats and was improved significantly by salusin-β gene knockdown. Salusin-β knockdown also improved cardiac function and vascular and myocardial remodeling, increased endothelial nitric oxide synthase (eNOS) activity and nitric oxide (NO) levels, and decreased NAD(P)H oxidase activity, NOX-2 and NOX-4 expression, and reactive oxygen species (ROS) levels in arteries in CHF rats. The effects of salusin-β knockdown in CHF rats were attenuated significantly by pretreatment with the NOS inhibitor L-NAME. These results indicate that silencing salusin-β contributes to the improvement of endothelial function, cardiac function, and cardiovascular remodeling in CHF by inhibiting NAD(P)H oxidase-ROS generation and activating eNOS-NO production.

Evaluation of salusin-α and salusin-β levels in patients with type 2 diabetes mellitus and determination of the impact of severity of hyperglycemia on salusin levels

AIMS

To investigate the usefulness of salusin-α and salusin-β as biomarkers in patients with type 2 diabetes mellitus (T2DM) and to determine whether diabetes severity and obesity have an effect on the salusin levels in diabetic patients.

METHODS

The study included a total of 90 patients, comprising 55 diagnosed with T2DM and 35 healthy volunteers with similar demographic characteristics. Salusins were assayed by a commercially available ELISA kit.

RESULTS

The salusin-β levels were found to be significantly higher in T2DM group compared to control group, while the salusin-α levels were lower (p < 0.05, for both). Furthermore, in patient group, Spearman analysis showed a statistically significant negative correlation between salusin-α and fasting glucose and glycated hemoglobin (HbA1c), whereas salusin-β had a statistically significant positive correlation with fasting glucose and HbA1c (p < 0.05, for both). When analyzed according to the HbA1c groups, the patients with HbA1c > 9% had significantly lower salusin-α and higher salusin-β levels levels compared to those with HbA1c < 9% (p < 0.05, for both). When examined according to body-mass-index groups, there was no significant difference in the salusin levels of the patient and control groups (p > 0.05).

CONCLUSION

We demonstrated that the serum salusin-α level was decreased whereas the salusin-β level was increased in patients with T2DM compared to healthy subjects, and this was more pronounced as T2DM-deteriorated. We also showed that obesity had no effect on salusin levels among diabetics. This study may provide a basis for the availability of salusin-targeted therapies, especially in uncontrolled T2DM.

Effectiveness of Continuous Aerobic Versus High-Intensity Interval Training on Atherosclerotic and Inflammatory Markers in Boys With Overweight/Obesity

PURPOSE

Atherosclerosis is a complex multifactorial disease whose first steps can be initiated from childhood. Therefore, we examined the effects of 2 training models on salusins levels, inflammatory markers, and lipid profile in boys with overweight/obesity.

METHOD

Forty-five boys with overweight/obesity with the mean age of 11.06 (1.0) years were randomly divided into three groups of 15: a high-intensity interval training (HIIT) group (100%-110% of maximum aerobic speed); an aerobic training group (40%-70% of heart rate reserve); and a control group. The intervention included 3 sessions per week for 12 weeks.

RESULTS

Findings showed significant improvements in serum levels of salusins, salusins ratio, interleukin-6 (IL-6), and total cholesterol (TC) in both training groups (P < .001). Also, the serum levels of C-reactive protein (CRP), triglycerides (TG), low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), atherogenic index of plasma (AIP), and cholesterol index improved significantly (P < .01). Except for the TG, HIIT caused higher improvements than aerobic training (P < .001 for salusin-α, salusins ratio, IL-6, CRP, TC, HDL, AIP, and cholesterol index; and P < .01 for salusin-β and LDL).

CONCLUSION

The present study shows that HIIT has more positive effects than aerobic exercise on the atherosclerotic and inflammatory factors, as well as lipid profile variables in children with overweight/obesity.

Influence of irisin on diet-induced metabolic syndrome in experimental rat model

OBJECTIVE

To evaluate the influence of irisin on the experimental paradigm of non-alcoholic fatty liver (NAFL) as a part of MetS cluster.

METHODS

Forty male albino rats were divided into four groups; normal control, standard diet + irisin, high carbohydrate and fat diet (HCHF), and HCHF + irisin. After the experimental period, levels of fasting blood sugar (FBS), insulin, lipid profile, kidney functions, salusin-alpha (Sal-α), adropin, and retinol-binding protein-4 (RBP-4) were evaluated. Peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1α) expression in skeletal muscle was evaluated by quantitative real-time PCR. Aorta, liver, pancreas, and skeletal muscle tissue samples were prepared for histopathological examination.

RESULTS

Rats administrated HCHF showed elevated levels of FBS, lipid profile, kidney functions, RBP-4, and downregulation of PGC-1α expression along with a decline in levels of insulin, Sal-α, and adropin while administration of irisin significantly attenuated these levels.

CONCLUSIONS

Irisin as based therapy could emerge as a new line of treatment against MetS and its related diseases.

Assessment of salusin alpha and salusin beta levels in patients with newly diagnosed dipper and non-dipper hypertension

OBJECTIVE

The pathophysiology of non-dipper hypertension has not been clarified. The relationship between salusins with atherosclerosis and hypertension has gained attention in recent years. The aim of this paper is to investigate whether salusins are associated with circadian blood pressure, left ventricular mass index, and diastolic functions in newly diagnosed hypertensives.

METHODS

The study included 88 newly diagnosed hypertensive individuals. Twenty-four-hour ambulatory blood pressure monitoring and echocardiographic examinations were performed. The patients were assigned to dipper hypertension (n = 41) and non-dipper hypertension (n = 47) groups based on the ambulatory blood pressure monitoring results according to the presence of ≥ a 10% decrease in nighttime blood pressure values or not. Serum salusin α and β levels were determined by electrochemiluminescence immunological test method.

RESULTS

Compared to dipper hypertension, non-dipper hypertension group demonstrated lower salusin α levels (1818.71 ± 221.67 vs 1963 ± 200.75 pg/mL, p = .002), mitral E/A, septal E'/A' and higher salusin β levels (576.24 ± 68.15 vs 516.13 ± 90.7 pg/ml, p = .001) and left ventricular mass index. Multivariate logistic regression analysis revealed salusin-α (OR 0.474, 95% CI 0.262 to 0.986, p = .001), salusin-β (OR 2.550, 95% CI 2.123 to 2.991, p = .018), and left ventricular mass index (OR 2.620, 95% CI 2.124 to 2.860, p = .011) as independent predictors of non-dipper hypertension. As candidate markers to predict non-dipper hypertension, decreased salusin α, and increased salusin β levels may mediate crosstalk between sympathetic and parasympathetic systems and indicate poor cardiovascular prognosis in hypertension.

Salusin- is superior to salusin- as a marker for evaluating coronary atherosclerosis

Objective

This study was performed to evaluate the interaction effect of salusin-α and salusin-β on coronary artery injury or stenosis.

Methods

The salusin-α and salusin-β concentrations were measured by enzyme-linked immunosorbent assay in 256 patients who underwent coronary angiography for chest pain, and coronary artery stenosis was assessed by the SYNTAX scoring system. Multivariate logistic regression was used to analyze the correlation between variables and coronary artery stenosis. The interaction of salusin-α and salusin-β on coronary artery stenosis was further explored by multiple linear regression.

Results

The model goodness of fit (R) for the interaction effect of salusin-α and salusin-β on coronary artery stenosis was 0.863, and the adjusted R value revealed that the interaction could explain 74.3% of the variation in SYNTAX scores. The F-statistic exceeded F_0.05 (3.031485935) and P < 0.001, further showing that salusin-α and salusin-β had a significant interaction effect on coronary artery stenosis. The standard coefficient for salusin-β (0.797) was higher than that for salusin-α (−0.367, indicating an inhibitory effect), showing that salusin-β had a greater effect on coronary artery stenosis.

Conclusions

Salusin-β, a potential marker for assessing coronary atherosclerosis, was superior to salusin-α, contributing to our understanding of the etiology of coronary artery stenosis.

Serum salusin-β in relation to atherosclerosis and ventricular dysfunction in patients with type 2 diabetes mellitus

BACKGROUND AND AIMS

Salusin-β is a newly defined biomarker that plays a role in atherogenesis and in homeostasis. The study aimed to assess serum salusin-β level in relation to atherosclerosis and ventricular dysfunction in type 2 diabetes mellitus (T2DM) patients.

METHODS

Sixty T2DM patients and twenty-five age-matched healthy controls were included. Serum salusin-β was determined by ELISA. Echocardiography and carotid ultrasonography were carried out for all individuals.

RESULTS

Serum salusin-β level was significantly elevated in patients with T2DM than in controls (P < 0.001). It was positively correlated with obesity parameters, insulin resistance index (r = 0.280,P < 0.001), atherogenic dyslipidemia and with carotid intima media thickness (CIMT) (r = 0.411, P < 0.001). Echocardiographic findings showed a positive correlation between salusin-β and left ventricular hypertrophy (LVH) parameters and a negative correlation with left ventricular (LV) diastolic and systolic functions. Regression analysis showed that serum salusin-β level was a significant predictor of diastolic dysfunction.

CONCLUSION

Serum salusin-β may be associated with atherosclerosis and LV dysfunction in T2DM.

The importance of circulating levels of salusin-α, salusin-β, and heregulin-β1 in atherosclerotic coronary arterial disease

OBJECTIVE

The relationship between the severity of atherosclerotic coronary artery disease (CAD) and circulating levels of salusin-α, salusin-β and heregulin-β1 has been investigated. In addition, the relationship with these peptides and high sensitive C-reactive protein (hsCRP) has been investigated.

METHODS

The study was conducted on 55 volunteers who had normal coronary angiography (CAG) as the control group, 35 volunteers with the degree of coronary artery stenosis below 50% in CA as the non-critical stenosis group, 37 volunteers with narrowing of one coronary artery above 50% as single vessel group and 41 volunteers with narrowing of more than one coronary artery above 50% as multi-vessel group. One hundred and thirteen volunteers have been included to CAD group.

RESULTS

There was no statistically significant difference in serum salusin-α levels between groups. Serum salusin-β ve hsCRP levels were significantly lower in control group compared to other groups and CAD group. There was no statistically significant difference in salusin-β and salusin-α levels in reciprocal comparison of other groups other than heregulin-β1 levels. Heregulin-β1 levels were significantly lower in 'non-critical occlusion' and 'multiple artery occlusion' groups compared to control group. Heregulin-β1 levels in 'single artery occlusion' group were significantly higher than control, 'non-critical occlusion' and 'multiple artery occlusion' groups.

CONCLUSION

Salusin-α levels does not indicate any significant differences between any groups in our study however the relationship of salusin-α with salusin- β and heregulin-β1 levels drives to cogitate that these peptides can be used as biomarkers and therapeutic approaches in CAD. We think that these peptides will be used in laboratories routinely in future in addition to hsCRP for CAD.

A TOR2A Gene Product: Salusin-β Contributes to Attenuated Vasodilatation of Spontaneously Hypertensive Rats

PURPOSE

Attenuated vasodilatation of small arteries is a hallmark feature of hypertension. Salusin-β, which is a TOR2A gene product and an important vasoactive peptide, has a close relationship with cardiovascular disease. This study aimed to determinate the roles of salusin-β in vasodilatation, and its signal pathways in Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR).

METHODS

Isometric tension experiments were performed. Vasodilatation was induced by acetylcholine (ACh) or sodium nitroprusside (SNP).

RESULTS

Plasma salusin-β levels and their protein expressions in coronary artery (CA), mesenteric artery (MA), and pulmonary artery (PA) of SHR were much higher than that of WKY. Intravenous injection of salusin-β increased arterial blood pressure in SHR, while anti-salusin-β IgG decreased it. Salusin-β further deteriorated, while anti-salusin-β IgG improved, the attenuated ACh-induced relaxation, the decreased nitric oxide (NO) level, and endothelial nitric oxide synthase (eNOS) activity in arteries of SHR, and salusin-β had no significant effect on SNP-induced relaxation. The NAD(P)H oxidase activity and reactive oxygen species (ROS) level in arteries of SHR were much higher than that of WKY, which was further increased by salusin-β but reduced by anti-salusin-β IgG. ROS scavenger NAC or antioxidant apocynin significantly inhibited, while SOD inhibitor DETC aggravated, the effects of salusin-β, and the eNOS inhibitor L-NAME inhibited the effects of anti-salusin-β IgG.

CONCLUSIONS

These results indicated that enhanced salusin-β activity is involved in attenuated endothelium-dependent vasodilatation pathogenesis in SHR by activating NAD(P)H oxidase derived ROS generation and inhibiting eNOS activation and NO release.

Metformin Delays the Development of Atherosclerosis in Type 1 Diabetes Mellitus via the Methylglyoxal Pathway

INTRODUCTION

The aim of our study was to determine the effect of metformin administration on juvenile type 1 diabetes mellitus and atherosclerosis in apolipoprotein E null (ApoE^-/-) mice and to explore the mechanism involved.

METHODS

Eighteen male ApoE^-/- mice were injected with streptozotocin to induce diabetes (diabetic group) and 18 mice who received no streptozotocin injection were assigned to the control (non-diabetic) group. Six mice in each group were then orally administered metformin, simvastatin, or vehicle, respectively, following which the mice were euthanized and tissue samples collected.

RESULTS

Fasting plasma glucose, low-density lipoprotein-cholesterol, and triglyceride concentrations were significantly higher in the three diabetic groups than in the three non-diabetic groups. Plasma N^∈-(carboxymethyl)lysine and N^∈-(carboxyethyl)lysine concentrations were higher in the diabetic mice than in the non-diabetic mice, but metformin treatment reduced these concentrations more effectively than simvastatin. All three diabetic groups demonstrated obvious arterial plaques, but these were largest in the vehicle-treated diabetic group. The expression of extracellular nitric oxide synthase was highest in the simvastatin-treated non-diabetic group, and in diabetic mice it was higher in the simvastatin-treated group than in the other two groups. No significant expression of AMP-activated protein kinase (AMPK) was measured in the three diabetic groups, but a low level of AMPK expression was detected in the non-diabetic groups.

CONCLUSIONS

Metformin can limit the development of atherosclerosis secondary to diabetes in young diabetic mice. A possible mechanism is the removal of methylglyoxal, thereby reducing the formation of advanced glycation endproducts, rather than by lowering the blood glucose level.

FUNDING

This work was supported by the National Natural Science Foundation of China (81901106) and Jinan clinical medical science and technology innovation plan (201907002).

Increased serum salusin-α by aerobic exercise training correlates with improvements in arterial stiffness in middle-aged and older adults

Aging causes arterial stiffening which can be mitigated by increased physical activity. Although low circulating levels of salusin-α are associated with cardiovascular disease, whether salusin-α decreases with aging and whether the reduced arterial stiffening occurring with exercise training is associated with increased serum salusin-α is unknown. Herein we assessed carotid-femoral pulse wave velocity (cfPWV), systolic (SBP) and diastolic (DBP) blood pressures in a cross-sectional study that compared young (20-39-year-old, n=45) versus middle-aged and older (40-80-year-old, n=60) subjects. We also performed an interventional study in which 36 young and 40 middle-aged and older subjects underwent eight weeks of aerobic exercise training. In the cross-sectional study, serum salusin-α levels were lesser in middle-aged and older subjects compared to young individuals and negatively correlated with age, SBP, DBP, or cfPWV. In the interventional study, exercise training increased serum salusin-α in middle-aged and older subjects. Notably, negative correlations were noted between the exercise training-induced changes in serum salusin-α and cfPWV, SBP and DBP. Results indicate that advanced age associates with low circulating salusin-α, the levels of which can be augmented by exercise training. Importantly, increased serum salusin-α with exercise correlates with improvements in arterial stiffness and a reduction in blood pressure.

Effects of Two Types of Moderate- and High-Intensity Interval Training on Serum Salusin-α and Salusin-β Levels and Lipid Profile in Women with Overweight/Obesity

OBJECTIVE

The current study aimed to compare the effects of two modes of moderate- and high-intensity interval training on serum Salusin-α and Salusin-β and lipid profile in women with overweight/obesity.

SUBJECTS AND METHODS

A number of forty females were assigned to each of (1) Control (BMI= 30.2 ± 2.8 kg/m², n=14), (2) Moderate-intensity (BMI= 31.2 ±3.3 kg/m², n=13) and (3) High-intensity interval training (BMI=30.9±3.4 kg/m², n=13) groups. The subjects of experimental groups participated in the selected interval trainings for eight weeks. The first blood sampling was performed within 48 hours prior to the first training session and the second samples were obtained 48 hours after the last training session.

RESULTS

The findings revealed that there were significant increases in Salusin-α (36% vs. 3%; p = 0.001) and high-density lipoprotein levels (7% vs. 5%; P = 0.039), while significant reductions in the levels of Triglyceride (-8% vs. -9%; p= 0.012) and total cholesterol (-1% vs. -8%; P =0.01) levels of moderate- and high-intensity interval training groups, respectively. Also, there were insignificant changes in Salusin-β (-7% vs. -5%; P = 0.108), low-density lipoproteins (-3% vs. -11%; P =0.046) and very-low-density lipoprotein (-10% vs. -8%; P = 0.056) compared to control group. There were only significant differences between Salusin-α and high-density lipoprotein levels of training groups (P<0.05).

CONCLUSION

It is suggested that, although improvements in lipid profile was nearly similar for two training modes, moderate intensity interval training was more effective to prevent and control atherosclerosis.

Salusin-β Promotes Vascular Calcification via Nicotinamide Adenine Dinucleotide Phosphate/Reactive Oxygen Species-Mediated Klotho Downregulation

Aims: Vascular calcification (VC) is a hallmark feature of cardiovascular disease and a significant risk factor for morbidity and mortality. Salusin-β exerts cardiovascular regulating effects in hypertension, atherosclerosis, and diabetes. The present study was designed to examine the roles of salusin-β in the progression of VC and its downstream signaling mechanisms. Results: Salusin-β expression in both the aortas of VC rats induced by vitamin D3 and nicotine and vascular smooth muscle cells (VSMCs) incubated with calcifying media was increased. Salusin-β knockdown remarkably reduced VC, whereas overexpression of salusin-β exacerbated VC both in vitro and in vivo. Overexpression of salusin-β promoted the VSMC osteochondrogenic transition, decreased Klotho protein levels, enhanced Ras-related C3 botulinum toxin substrate 1 (Rac1) activity and the translocation of p47phox to the membrane, increased the expression of nicotinamide adenine dinucleotide phosphate [NAD(P)H] oxidase subunits and the production of reactive oxygen species (ROS) with or without calcifying media; however, salusin-β deficiency played the opposite roles. The calcification and downregulated Klotho protein levels induced by salusin-β were restored by ROS scavenger N-acetyl-l-cysteine, diphenyleneiodonium chloride [an inhibitor of flavin-containing enzyme, including NAD(P)H oxidase], or gene knockdown of NAD(P)H oxidase (NOX)-2, p22phox, or p47phox but were not affected by NOX-1 and NOX-4 knockdown. Klotho knockdown attenuated the protective effect of salusin-β deficiency on VSMC calcification. By contrast, exogenous Klotho ameliorated the development of VC and ROS generation induced by salusin-β overexpression. Innovation: Salusin-β is a critical modulator in VC. Conclusion: Salusin-β regulates VC through activation of NAD(P)H/ROS-mediated Klotho downregulation, suggesting that salusin-β may be a novel target for treatment of VC.

Salusin-β mediates tubular cell apoptosis in acute kidney injury: Involvement of the PKC/ROS signaling pathway

Salusin-β is abundantly expressed in many organs and tissues including heart, blood vessels, brain and kidneys. Recent studies have identified salusin-β as a bioactive peptide that contributes to various diseases, such as atherosclerosis, hypertension, diabetes and metabolic syndrome. However, the role of salusin-β in the pathogenesis of acute kidney injury (AKI) is largely unclear. In the present study, we investigated the roles of salusin-β in cisplatin or lipopolysaccharide (LPS)-induced renal injury. Herein, we found that salusin-β expression was upregulated in both renal tubular cells and kidney tissues induced by both cisplatin and LPS. In vitro, silencing of salusin-β diminished, whereas overexpression of salusin-β exaggerated the increased PKC phosphorylation, oxidative stress, histone γH2AX expression, p53 activation and apoptosis in either cisplatin or LPS-challenged renal tubular cells. More importantly, salusin-β overexpression-induced tubular cell apoptosis were abolished by using the PKC inhibitor Go 6976, reactive oxygen species (ROS) scavenger NAC, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor apocynin (Apo) or p53 inhibitor Pifithrin-α. In animals, blockade of salusin-β alleviated PKC phosphorylation, ROS accumulation, DNA damage, and p53 activation as well as renal dysfunction in mice after administration of cisplatin or LPS. Taken together, these results suggest that overexpressed salusin-β is deleterious in AKI by activation of the PKC/ROS signaling pathway, thereby priming renal tubular cells for apoptosis and death.

Salusin-α mitigates diabetic nephropathy via inhibition of the Akt/mTORC1/p70S6K signaling pathway in diabetic rats

Salusin-α is a bioactive peptide that protects against atherosclerosis and hepatosteatosis. Serum salusin-α level is declined in patients suffering with renal insufficiency. However, it is still undefined whether salusin-α plays a role in diabetic nephropathy. The present study was designed to investigate the potential roles of salusin-α in diabetic renal disease. Herein, we demonstrated that the salusin-α levels in both plasma and kidney tissues from diabetic rats were obviously downregulated. Exogenous administration of salusin-α eliminated the typical characteristics of diabetic nephropathy. Salusin-α treatment decreased renal fibrosis, which was related with reduced epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells. Injection of salusin-α suppressed the production of reactive oxygen species (ROS) via attenuation of NADPH oxidase subunits protein expressions and recovery of the antioxidant system. Mechanistically, the activated Akt/mTORC1/p70S6K signaling pathway in diabetic nephropathy was counteracted by salusin-α treatment. Our results demonstrated that salusin-α exerted protective effect against diabetic nephropathy via reduced oxidative stress and fibrosis, dependent on inactivation of the Akt/mTORC1/p70S6K signaling cascade. Salusin-α may be considered as a promising target for the treatment of diabetic nephropathy.

Relationship of serum salusin beta levels with coronary slow flow

OBJECTIVE

The pathophysiology of coronary slow flow (CSF) has not been clarified. Salusin-β is released predominantly from the atheroma plaques and influences the pathophysiologic processes of atherosclerosis. Therefore, this study aimed to determine serum salusin-β levels in CSF and its correlation with CSF.

METHODS

The study included 39 patients with CSF, and the control group (n=42) consisted of consecutive subjects with normal coronary arteriogram. We measured salusin-β and thrombolysis in myocardial infarction frame count (TFC).

RESULTS

Age, body mass index (BMI), systolic blood pressure, diabetes, hyperlipidemia, and smoking rates were similar (p values>0.05) in both groups. High sensitive C-reactive protein (2.80±1.2 vs. 2.21±1.2 mg/dL, p=0.011), salusin-β [1205 (330-2092) vs. 162 (29-676), pg/ml, p<0.001], corrected TFC of left anterior descending coronary artery (29±9 vs. 19.7±3.7, p<0.001), circumflex artery TFC (25±10 vs. 15±3.2, p<0.001), right coronary artery TFC (28±7.1 vs. 13±3.3, p<0.001), and mean TFC (28±4.4 vs. 16±3.7, p<0.001) were significantly higher in the CSF group. In univariate and multivariate regression analysis, only BMI (unstandardized β±SE=0.178±0.08, p=0.036) and salusin-β levels (unstandardized β±SE=0.006±0.01, p<0.001) were determined as predictors of CSF. There was a good correlation between serum salusin-β and mean TFC values (r=0.564; p<0.001).

CONCLUSION

There is an association between serum salusin-β levels and CSF.

Salusin-α levels are negatively correlated with diastolic blood pressure in children with obesity

Salusins have emerged as a new biomarker that reflects an increased inflammatory state, which is associated with cardiovascular risk. We investigated the predictive value and usefulness of salusins as an inflammatory biomarker in obese children. This prospective cohort study included 75 obese children and 101 healthy children (as a control group). Salusin-α, Salusin-β, and various cardiovascular parameters were assessed in both groups. Correlation analyses of Salusin-α and Salusin-β with body mass index standard deviation scores and inflammatory and cardiovascular markers were performed. The mean patient age was 11.9±2.4 years for the obese group and 12.5±2.1 years for the control group. The obese children had a significantly higher heart rate, systolic blood pressure, diastolic blood pressure, epicardial adipose tissue thickness, and left ventricular mass than did the children in the control group. There was no significant correlation between Salusin-α and Salusin-β and body mass index; however, there was a negative correlation between Salusin- α and diastolic blood pressure (r = 0.277, p = 0.004). Overall, there was no significant difference in the Salusin-α and Salusin-β levels between obese and healthy children. However, a negative correlation was found between Salusin-α and diastolic blood pressure. Although this result suggests that Salusin-α might be an early marker of cardiovascular involvement in obese children, further studies are needed to demonstrate the predictive value of salusins.

Identification of the salusin-β receptor using proteoliposomes embedded with endogenous membrane proteins

Although orphan G protein-coupled receptors (GPCRs) have been used as targets to discover unidentified natural ligands, increasing numbers of non-GPCRs have been found to mediate important biological functions. Bioinformatics of genome and cDNA resources predict putative bioactive peptides, demanding an alternative approach to efficiently unravel cell surface targets. In silico analysis of a full-length cDNA library previously allowed us to identify salusin-β, a parasympathomimetic/pro-atherosclerotic peptide with unique physicochemical properties. Here, we show that the β-chain of ATP synthase is a cell surface receptor for salusin-β by utilizing artificial liposomes embedded with endogenous membrane proteins directly transferred from animal tissues while retaining the ligand-binding capability. Conventional techniques using detergents identified a β-actin-profilin complex as membrane-associated salusin-β-binding proteins, but failed to identify the cell surface receptor. Since the α-chain of ATP synthase is a principal cell surface target for angiostatin, a potent endogenous angiogenesis inhibitor, we investigated whether salusin-β modulates angiogenesis. Salusin-β inhibited cell surface ATP synthase activity and prevented sarcoma cell-induced angiogenesis in an in vivo mouse air sac model. Therefore, salusin-β binds to membrane-bound ATP synthase and acts as an angiogenesis inhibitor. The current methodology allows the identification of novel cell surface targets, irrespective of the receptor structure.

Relationship of salusin-alpha and salusin-beta levels with atherosclerosis in patients undergoing haemodialysis

INTRODUCTION

In patients undergoing haemodialysis, cardiovascular mortality and morbidity, characterised by accelerated atherosclerosis and increased inflammation, are elevated. Salusins are newly defined molecules in the atherosclerotic processes, and while salusin-alpha (Sal-α) acts as an antiatherogenic factor, salusin-beta (Sal-β) has a proatherogenic role. Their roles are as yet undefined in patients undergoing haemodialysis.

METHODS

In this cross-sectional study, salusin levels, carotid intima-media thickness (CIMT) from the common carotid artery and pulse wave velocity (PWV) were measured for 180 patients undergoing haemodialysis and 90 healthy controls.

RESULTS

Mean Sal-α and Sal-β levels in patients undergoing haemodialysis (Sal-α: 726.4 ± 578.7 pg/mL; Sal-β: 1,080.4 ± 757.1 pg/mL) and healthy controls (Sal-α: 325.8 ± 303.7 pg/mL; Sal-β: 268.1 ± 409.0 pg/mL) were determined. Negative correlation was observed between Sal-α levels and CIMT (patients undergoing haemodialysis: r = -0.330, p < 0.0001; healthy controls: r = -0.223, p = 0.035) and PWV (patients undergoing haemodialysis: r = -0.210, p = 0.005; healthy controls: r = -0.378, p < 0.0001) in both groups. In patients undergoing haemodialysis, positive correlation was observed between Sal-β/Sal-α ratio and CIMT (r = 0.190, p = 0.012) and PWV (r = 0.155, p = 0.041). On subgroup analysis, Sal-α levels were found to be low in patients with diabetes mellitus.

CONCLUSION

Patients undergoing haemodialysis have higher Sal-β and Sal-α levels, and their higher Sal-β/Sal-α ratio, in comparison with healthy controls, might have cardiovascular risk implications.

Adropin Contributes to Anti-Atherosclerosis by Suppressing Monocyte-Endothelial Cell Adhesion and Smooth Muscle Cell Proliferation

Adropin, a peptide hormone expressed in liver and brain, is known to improve insulin resistance and endothelial dysfunction. Serum levels of adropin are negatively associated with the severity of coronary artery disease. However, it remains unknown whether adropin could modulate atherogenesis. We assessed the effects of adropin on inflammatory molecule expression and human THP1 monocyte adhesion in human umbilical vein endothelial cells (HUVECs), foam cell formation in THP1 monocyte-derived macrophages, and the migration and proliferation of human aortic smooth muscle cells (HASMCs) in vitro and atherogenesis in Apoe-/- mice in vivo. Adropin was expressed in THP1 monocytes, their derived macrophages, HASMCs, and HUVECs. Adropin suppressed tumor necrosis factor α-induced THP1 monocyte adhesion to HUVECs, which was associated with vascular cell adhesion molecule 1 and intercellular adhesion molecule 1 downregulation in HUVECs. Adropin shifted the phenotype to anti-inflammatory M2 rather than pro-inflammatory M1 via peroxisome proliferator-activated receptor γ upregulation during monocyte differentiation into macrophages. Adropin had no significant effects on oxidized low-density lipoprotein-induced foam cell formation in macrophages. In HASMCs, adropin suppressed the migration and proliferation without inducing apoptosis via ERK1/2 and Bax downregulation and phosphoinositide 3-kinase/Akt/Bcl2 upregulation. Chronic administration of adropin to Apoe-/- mice attenuated the development of atherosclerotic lesions in the aorta, with reduced the intra-plaque monocyte/macrophage infiltration and smooth muscle cell content. Thus, adropin could serve as a novel therapeutic target in atherosclerosis and related diseases.

Salusin-α attenuates hepatic steatosis and atherosclerosis in high fat diet-fed low density lipoprotein receptor deficient mice

Salusin-α is an endogenous bioactive peptide and likely to prevent atherosclerosis. But its protective effect against atherosclerosis in vivo remains poorly understood. The aim of the present study was to determine the potential effects of salusin-α on atherosclerosis and its associated metabolic disorders in high fat diet (HFD)-fed low density lipoprotein receptor deficient (LDLr^-/-) mice, and also explore the possible underlying mechanisms involved. Our data showed that after 12 weeks treatment, salusin-α ameliorated HFD-induced weight gain, hyperlipidemia, and serum levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Salusin-α suppressed HFD-induced hepatic steatosis and regulated gene expression of fatty acid synthase, acetyl coenzyme A carboxylase-α, peroxisome proliferator-activated receptor-α, camitine palmitoyltransferase-1α and CYP7A1 in liver. Salusin-α reduced atherosclerotic plaque area and macrophage foam cell formation. Salusin-α prevented hepatic and aortic inflammation as evidenced by the reduced macrophage recruitment and mRNA expression of IL-6 and TNF-α in both liver and aorta. Salusin-α also reduced hepatic and aortic oxidative stress by normalizing activities of antioxidant enzymes in liver and suppressing reactive oxygen species generation and protein expressions of NADPH-oxidase (NOX) 2 and NOX4 in both liver and aorta. Our present data suggest that salusin-α could reduce hepatic steatosis and atherosclerosis via its pleiotropic effects, including amelioration of lipid profiles, regulation of some key molecules involved in lipid metabolism in liver, anti-oxidative effect and anti-inflammatory action.

Emerging Roles of Tumor Necrosis Factor-Stimulated Gene-6 in the Pathophysiology and Treatment of Atherosclerosis

Tumor necrosis factor-stimulated gene-6 (TSG-6) is a 35-kDa glycoprotein that has been shown to exert anti-inflammatory effects in experimental models of arthritis, acute myocardial infarction, and acute cerebral infarction. Several lines of evidence have shed light on the pathophysiological roles of TSG-6 in atherosclerosis. TSG-6 suppresses inflammatory responses of endothelial cells, neutrophils, and macrophages as well as macrophage foam cell formation and vascular smooth muscle cell (VSMC) migration and proliferation. Exogenous TSG-6 infusion and endogenous TSG-6 attenuation with a neutralizing antibody for four weeks retards and accelerates, respectively, the development of aortic atherosclerotic lesions in ApoE-deficient mice. TSG-6 also decreases the macrophage/VSMC ratio (a marker of plaque instability) and promotes collagen fibers in atheromatous plaques. In patients with coronary artery disease (CAD), plasma TSG-6 levels are increased and TSG-6 is abundantly expressed in the fibrous cap within coronary atheromatous plaques, indicating that TSG-6 increases to counteract the progression of atherosclerosis and stabilize the plaque. These findings indicate that endogenous TSG-6 enhancement and exogenous TSG-6 replacement treatments are expected to emerge as new lines of therapy against atherosclerosis and related CAD. Therefore, this review provides support for the clinical utility of TSG-6 in the diagnosis and treatment of atherosclerotic cardiovascular diseases.

Neopterin Counters Vascular Inflammation and Atherosclerosis

BACKGROUND

Neopterin, a metabolite of GTP, is produced by activated macrophages and is abundantly expressed within atherosclerotic lesions in human aorta and carotid and coronary arteries. We aimed to clarify the influence of neopterin on both vascular inflammation and atherosclerosis, as neither effect had been fully assessed.

METHODS AND RESULTS

We investigated neopterin expression in coronary artery lesions and plasma from patients with coronary artery disease. We assessed the atheroprotective effects of neopterin in vitro using human aortic endothelial cells, human monocyte-derived macrophages, and human aortic smooth muscle cells. In vivo experiments included a study of aortic lesions in apolipoprotein E-deficient mice. Neopterin expression in coronary artery lesions and plasma was markedly increased in patients with versus without coronary artery disease. In human aortic endothelial cells, neopterin reduced proliferation and TNF-α (tumor necrosis factor α)-induced upregulation of MCP-1 (monocyte chemotactic protein 1), ICAM-1 (intercellular adhesion molecule 1), and VCAM-1 (vascular cell adhesion molecule 1). Neopterin attenuated TNF-α-induced monocyte adhesion to human aortic endothelial cells and the inflammatory macrophage phenotype via NF-κB (nuclear factor-κB) downregulation. Neopterin suppressed oxidized low-density lipoprotein-induced foam cell formation associated with CD36 downregulation and upregulation of ATP-binding cassette transporters A1 and G1 in human monocyte-derived macrophages. In human aortic smooth muscle cells, neopterin suppressed angiotensin II-induced migration and proliferation via c-Src/Raf-1/ERK1/2 downregulation without inducing apoptosis. Exogenous neopterin administration and endogenous neopterin attenuation with its neutralizing antibody for 4 weeks retarded and promoted, respectively, the development of aortic atherosclerotic lesions in apolipoprotein E-deficient mice.

CONCLUSIONS

Our results indicate that neopterin prevents both vascular inflammation and atherosclerosis and may be induced to counteract the progression of atherosclerotic lesions. Consequently, neopterin could be of use as a novel therapeutic target for atherosclerotic cardiovascular diseases.

Identification and quantification of plasma free salusin-β, an endogenous parasympathomimetic peptide

Salusin-β is an endogenous parasympathomimetic proatherosclerotic peptide. Salusin-β was initially predicted from bioinformatic analyses and later immunologically detected in human biofluids. However, elucidation of salusin-β bioactivity has faced enormous challenges because of its unique physicochemical characteristics that cause it to strongly adhere to laboratory apparatus materials. In the strictest sense, the discovery of bioactive peptides is not complete until their exact native sequences have been confirmed in the peripheral circulation. In this study, we determined the plasma molecular form and levels of free salusin-β to determine its pathophysiological significance. Ultra-high-yield enrichment and preseparation of non-tryptic human plasma was followed by LC-MS/MS, and full-length salusin-β and seven different endogenous fragment sequences were identified. We established a new ELISA that specifically detects plasma free salusin-β without cross-reacting with any of its identified endogenous fragments. Free salusin-β levels exhibited a profound early morning nadir and rapidly decreased in response to parasympathetic nervous augmentation. Our technical advance in plasma native peptide analysis successfully identified a hard-to-detect bioactive peptide, salusin-β, together with its formerly unrecognized fragments, and further suggests that conventional immunological measurements of target peptides may not be fully representative.

The time changes of endogenous salusin-β in septic rats

Salusin-α and salusin-β are newly found bioactive peptides of 28 and 20 amino acids, respectively, which are widely distributed in the hematopoietic system, endocrine system, and central nervous system. Salusins exert cardiovascular effects, including hypotension and bradycardia; promote vascular inflammation; and so on. However, little information is available yet on the relationships of salusin-β with sepsis. In this study, we investigated the distribution and content of endogenous salusin-β in septic rats. A total of 72 specified pathogen-free (SPF) male Sprague-Dawley (SD) rats were randomly divided into control group (sham operation, n = 36) and experimental group (n = 36) with sepsis rat model by cecal ligation and puncture (CLP). The model group rats were sacrificed after 6, 12, and 24 h of treatment. The concentration of salusin-β in spleen, stomach, small intestine, hypothalamus, and serum specimens was detected by enzyme-linked immunosorbent assay (ELISA). It showed that salusin-β was endogenously generated in rat tissues, including spleen, stomach, small intestine, hypothalamus, and serum. The content of salusin-β in the spleen was higher than that in other tissues. The content of salusin-β in the spleen, stomach, and small intestine, together with the serum level of salusin-β, increased significantly at 6 h after CLP compared with the control group ( P < 0.05). The content of salusin-β in spleen and serum peaked at 12 h, and in small intestine, it reached the summit at 24 h. Meanwhile, no significant fluctuations in salusin-β content were observed in the stomach. The content of salusin-β in hypothalamus began to increase at 6 h, and a significant increase appeared 12 h after CLP ( P < 0.05). In conclusion, this study shows that the time-dependent alterations of salusin-β in septic rats suggest that salusin-β might be involved in the pathogenesis of sepsis.

The cardiovascular functions of salusin-β mediated by muscarinic receptors, glutamate receptors or L-type calcium channels within the rostral ventrolateral medulla of rats

Salusin-α and salusin-β are newly identified bioactive peptides of 28 and 20 amino acids, respectively, that were initially predicted using in silico analyses and are widely distributed in the endocrine system, hematopoietic system, and central nervous system. The goal of our study was to investigate the cardiovascular effect of salusin-β microinjections into the rostral ventrolateral medulla (RVLM) in anesthetized rats and study their mechanism of action. Microinjection of the artificial cerebrospinal fluid (aCSF) into the RVLM did not affect the blood pressure (BP) or heart rate (HR) in anesthetized rats. Topical application of salusin-β into the RVLM produced a dose-dependently increase of BP in anesthetized rats. Microinjection of higher dose salusin-β produced significant tachycardia. Prior application of the L-NAME into the RVLM of rats did not alter the hypertension and tachycardia induced by intra-RVLM salusin-β. Notable, the cardiovascular functions elicited by intra-RVLM salusin-β were significantly decreased by pretreatment with Nic, KYN and atropine. In conclusion, the present study shows that the hypertension and tachycardia induced by intra-RVLM salusin-β might be partly mediated, at least in our opinion, by muscarinic receptors, glutamate receptors or L-type calcium channels.

IS SALUSIN-ALPHA A NEW MARKER OF CARDIOVASCULAR DISEASE RISK IN HYPOTHYROIDISM?

Introduction

Salusins are multifunctional endogenous peptides shown in human and rat tissues. Serum salusin α level is decreased in coronary artery disease and lack of salusin α enhances coronary atherosclerosis. Hypothyroidism is a chronic inflammatory disease that has a high risk of developing cardiovascular disease. Here we aimed to search the relationship of overt hypothyroidism and subclinical hypothyroidism with salusin α and other inflammatory markers, also the effect of L-thyroxine treatment on these findings.

Material and Methods

32 patients with overt hypothyroidism taking L-thyroxine treatment, 18 patients with subclinical hypothyroidism without treatment and 25 healthy patients as control group were included in the study. Serum salusin α, TNF α, sCRP, glucose, insulin and lipid levels were tested for all groups and results were evaluated with SPSS statistical analysis method.

Results

HDL, sCRP, salusin mean values were statistically significantly different in all 3 groups. HDL level was statistically significantly higher in control group compared to treatment group. sCRP level was higher and salusin level was lower in both treatment and non-treatment hypothyroidism groups compared to control group. When treatment and non-treatment hypothyroidism groups were compared, there was no statistically significant difference for salusin α, but HDL level was high and insulin level was low statistically significant in treatment group.

Conclusions

Salusin α that is shown to be protective for coronary artery disease and hypertension, is found to be significantly low in hypothyroidism, thus it is a marker that increases the cardiovascular disease risk in this specific patient group.

Atheroprotective Effects of Tumor Necrosis Factor-Stimulated Gene-6

Tumor necrosis factor-stimulated gene-6 (TSG-6), an anti-inflammatory protein, was shown to be localized in the neointima of injury-induced rat arteries. However, the modulatory effect of TSG-6 on atherogenesis has not yet been reported. We aimed to evaluate the atheroprotective effects of TSG-6 on human endothelial cells (HECs), human monocyte-derived macrophages (HMDMs), human aortic smooth muscle cells (HASMCs) in vitro, and aortic lesions in apolipoprotein E-deficient mice, along with expression levels of TSG-6 in coronary lesions and plasma from patients with coronary artery disease (CAD). TSG-6 was abundantly expressed in HECs, HMDMs, and HASMCs in vitro. TSG-6 significantly suppressed cell proliferation and lipopolysaccharide-induced up-regulation of monocyte chemotactic protein-1, intercellular adhesion molecule-1, and vascular adhesion molecule-1 in HECs. TSG-6 significantly suppressed inflammatory M1 phenotype and suppressed oxidized low-density lipoprotein-induced foam cell formation associated with down-regulation of CD36 and acyl-CoA:cholesterol acyltransferase-1 in HMDMs. In HASMCs, TSG-6 significantly suppressed migration and proliferation, but increased collagen-1 and -3 expressions. Four-week infusion of TSG-6 into apolipoprotein E-deficient mice significantly retarded the development of aortic atherosclerotic lesions with decreased vascular inflammation, monocyte/macrophage, and SMC contents and increased collagen fibers. In addition, it decreased peritoneal M1 macrophages with down-regulation of inflammatory molecules and lowered plasma total cholesterol levels. In patients with CAD, plasma TSG-6 levels were significantly increased, and TSG-6 was highly expressed in the fibrous cap within coronary atherosclerotic plaques. These results suggest that TSG-6 contributes to the prevention and stability of atherosclerotic plaques. Thus, TSG-6 may serve as a novel therapeutic target for CAD.

Genetic Modifiers of White Blood Cell Count, Albuminuria and Glomerular Filtration Rate in Children with Sickle Cell Anemia

Discovery and validation of genetic variants that influence disease severity in children with sickle cell anemia (SCA) could lead to early identification of high-risk patients, better screening strategies, and intervention with targeted and preventive therapy. We hypothesized that newly identified genetic risk factors for the general African American population could also impact laboratory biomarkers known to contribute to the clinical disease expression of SCA, including variants influencing the white blood cell count and the development of albuminuria and abnormal glomerular filtration rate. We first investigated candidate genetic polymorphisms in well-characterized SCA pediatric cohorts from three prospective NHLBI-supported clinical trials: HUSTLE, SWiTCH, and TWiTCH. We also performed whole exome sequencing to identify novel genetic variants, using both a discovery and a validation cohort. Among candidate genes, DARC rs2814778 polymorphism regulating Duffy antigen expression had a clear influence with significantly increased WBC and neutrophil counts, but did not affect the maximum tolerated dose of hydroxyurea therapy. The APOL1 G1 polymorphism, an identified risk factor for non-diabetic renal disease, was associated with albuminuria. Whole exome sequencing discovered several novel variants that maintained significance in the validation cohorts, including ZFHX4 polymorphisms affecting both the leukocyte and neutrophil counts, as well as AGGF1, CYP4B1, CUBN, TOR2A, PKD1L2, and CD163 variants affecting the glomerular filtration rate. The identification of robust, reliable, and reproducible genetic markers for disease severity in SCA remains elusive, but new genetic variants provide avenues for further validation and investigation.