Salusins, newly identified regulators of hemodynamics and mitogenesis, increase in polycystic ovarian syndrome

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.

Intracerebroventricular salusin-β infusion to rats increases hypothalamus-pituitary-testicular axis hormones

Salusin-β (Sal-β), which originates from preprosalusin, is a multifunctional hormone with a peptide structure. Sal-β exists in the hypothalamus and can stimulate the pituitary gland. The present study was conducted to determine the effects of Sal-β on hormones that play roles in the male reproductive system. Forty male Wistar Albino rats were used in the study. No infusions were performed on the control group, and infusions were applied to the infusion groups (artificial cerebrospinal fluid to the sham group, 2 and 20 nM Sal-β to the experimental group) through intracerebroventricular infusion for 7 days at 10 μl/hour rate. The animals were decapitated after 7 days of infusion; and the hypothalamus, testicles, and blood tissue samples were collected. The gonadotropin-releasing hormone (GnRH) mRNA levels were determined from the hypothalamus tissues by using the Real Time-PCR Method, and the serum luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone levels were determined using the ELISA method. Also, Hematoxylin-Eosin Staining Method was used for histopathological evaluations in the testicle tissues. As a result, Sal-β infusion increased GnRH mRNA levels in hypothalamus tissues (p < 0.05) besides, serum LH, FSH, and testosterone levels of the rats were higher at significant levels following Sal-β infusion compared to the control and sham group (p < 0.05). In the histological examination of the testicle tissues, Sal-β application was found to decrease the seminiferous tubule diameter and germinal epithelial thickness (p < 0.05). This evidence is the first, indicating that Sal-β, which is administered to male rats with central infusion, stimulates hypothalamus and pituitary tissues, and causes increased secretion of male reproductive hormones.

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.

Overexpression of salusin-β is associated with poor prognosis in ovarian cancer

Ovarian cancer is recognized as one of the worst gynecologic malignancies associated with rapid metastasis and poor overall survival rate. The identified valuable molecular biomarkers criticize importance of timely diagnosis for ovarian cancer. Salusin-β levels are dramatically increased in women with polycystic ovarian syndrome. However, the roles of salusin-β in ovarian cancer have yet to be fully elucidated. A total of 57 paired ovarian cancer specimens and matched adjacent normal tissues were used to measure the salusin-β levels. The prognostic value of salusin-β for tumor progression and survival rate was investigated. The effects of salusin-β on ovarian cancer cell proliferation and epithelial-mesenchymal transition were also explored. The expression of salusin-β was significantly increased in ovarian cancer tissue specimens compared with matched normal adjacent tissue (P<0.05). The high salusin-β level was closely related with FIGO stage and lymph node metastases. The ovarian cancer patients with high salusin-β had a shorter overall survival (P<0.05). Salusin-β obviously enhanced the proliferation and epithelial mesenchymal-transition of SKOV3 cells. Furthermore, salusin-β substantially decreased the expression of p-GSK-3β and GSK-3β, but stimulated the β-catenin expression and downstream genes of wnt/β-catenin including cyclin D1 and C-myc. Our data demonstrated for the first time that upregulated salusin-β may be a novel independent prognostic biomarker for overall survival of ovarian cancer. Salusin-β accelerated the proliferation and epithelial mesenchymal transition of ovarian cancer cells at least partly via activation of Wnt/β-catenin signaling pathway. Salusin-β may be an important target for therapeutic intervention in ovarian cancer.

Salusins and adropin: New peptides potentially involved in lipid metabolism and atherosclerosis

Dyslipidemia is one of the most potent risk factors for the development of atherosclerosis. The high atherosclerotic risk in dyslipidemic patients is associated with endothelial dysfunction. During the last two decades, novel bioactive peptides have emerged as potential biomarkers of endothelial dysfunction and dyslipidemia-salusins and adropin. Salusin-alpha is likely to prevent atherosclerosis, while salusin-beta may act as a potential proatherogenic factor. Adropin was recently identified as important for energy homeostasis and lipid metabolism. Adropin is closely related to the inhibition of atherosclerosis by up-regulation of the endothelial nitric oxide synthase expression through the vascular endothelial growth factor receptor-2. These peptides represent a novel target to limit diseases characterized by endothelial dysfunction and may form the basis for the development of new therapeutic agents for treating metabolic disorders associated with atherosclerosis.