Identification of adropin as a secreted factor linking dietary macronutrient intake with energy homeostasis and lipid metabolism

Discovery of peptides as key regulators of metabolic and cardiovascular crosstalk

Peptides are fundamental regulators of metabolism, with several already developed as drugs, including glucagon-like peptide-1-based peptide therapeutics for diabetes and obesity. Despite their established importance, our understanding of their biosynthesis, modifications, receptor interactions, and signaling pathways remains incomplete. Advances in peptidomics and proteomics, particularly mass spectrometry, have facilitated peptide discovery and characterization, revealing novel roles for known peptides and uncovering previously unrecognized post-translational modifications. With the increasing prevalence of metabolic diseases driven by obesity, understanding the regulatory functions of peptide hormones has significant therapeutic potential. This review discusses the latest insights into peptide biology, highlighting key examples of peptides controlling tissue crosstalk, as well as how multi-omics technologies, computational approaches, and AI-driven methods are likely to expand our knowledge of peptide-mediated metabolic regulation.

The potential role of adipokines and hepatokines in age-related ocular diseases

Age-related ocular diseases, including diabetic retinopathy (DR), age-related macular degeneration (AMD), cataract and glaucoma may lead to visual impairment and even to blindness. Metabolic diseases, such as obesity and metabolic dysfunction-associated steatotic liver disease (MASLD) have emerged as potential risk factors of age-related ocular diseases, especially DR. Visceral adiposity has been associated with increased risk of DR and AMD in most clinical studies, although body mass index has to-date provided conflicting association with DR and AMD. In addition, obesity is recognized as a risk factor of cataract and glaucoma. Similarly to obesity, MASLD appears to be associated with DR in patients with type 1 diabetes mellitus, but probably not in those with type 2 diabetes mellitus. A potential positive association between MASLD and AMD, glaucoma and cataract is supported by limited evidence to-date, thus needing further investigation. Altered secretion patterns of adipokines (adiponectin, leptin, lipocalin-2, resistin) and hepatokines [adropin, fetuin-A, fibroblast growth factor (FGF)-21, retinol binding protein (RBP)-4] seem to disrupt ocular homeostasis and contribute to the development of age-related ocular diseases in the context of obesity and MASLD. In this regard, novel adipokine-based and hepatokine-based therapies may be added to the treatment options for ocular diseases in the future. This narrative review aimed to summarize evidence on the interconnection of obesity and MASLD with age-related ocular diseases, with a specific focus on the roles of adipokines and hepatokines as mediators of these potential associations.

Bridging systemic metabolic dysfunction and Alzheimer's disease: the liver interface

Alzheimer's disease (AD) is increasingly recognized as a systemic disorder with a substantial metabolic disorder component, where the liver significantly impacts the brain via the liver-brain axis. Key mechanisms include the liver's role in clearing peripheral β-amyloid (Aβ), the influence of hepatic enzymes and metabolites on cognitive decline, and the systemic effects of metabolic disorders on AD progression. Hepatokines, liver-secreted proteins including fibroblast growth factor (FGF)-21, selenoprotein P (SELENOP), Fetuin-A, Midbrain astrocyte-derived neurotrophic factor (MANF), apolipoprotein J (ApoJ), sex hormone-binding globulin (SHBG), Adropin and Angiopoietin-like protein 3 (ANGPTL3), could regulate insulin sensitivity, lipid metabolism, oxidative stress, immune responses, and neurotrophic support. These pathways are closely linked to core AD pathologies, including Aβ aggregation, tau hyperphosphorylation, neuroinflammation, oxidative stress and mitochondrial dysfunction. Lifestyle interventions, including exercise and dietary modifications, that regulate hepatokines expression may offer novel preventive and therapeutic strategies for AD. This review synthesizes current knowledge on the liver-brain crosstalk in AD, emphasizing the mechanistic role of liver in bridging metabolic dysfunction with neurodegeneration and underscores the diagnostic and therapeutic potential of hepatokines in addressing AD's complex pathology.

Comparison of Dexmedetomidine and Remifentanil on Adropin Expression in Unilateral Lumbar Microdiscectomy: A Prospective Active Controlled Randomized Trial Study

Background/Objectives: Remifentanil and dexmedetomidine are widely used agents for pain management during general anesthesia. Adropin acts as a regulator of endothelial function by affecting nitric oxide bioavailability and various hemodynamic factors, including blood flow, vascular dilatation, and mean arterial pressure. We aimed to evaluate the effects of remifentanil and dexmedetomidine on adropin and eNOS levels and hemodynamic parameters in patients undergoing unilateral single-level lumbar microdiscectomy under controlled hypotension. Methods: This study included 40 patients who underwent lumbar microdiscectomy and were randomly assigned to two groups: 20 patients received remifentanil, and 20 received dexmedetomidine. Hemodynamic parameters, preoperative and postoperative VAS scores, and intraoperative blood loss were recorded. Adropin and eNOS mRNA levels were measured with RT-qPCR at three time points: preoperative (T1), intraoperative (T2), and postoperative (T3). Adropin protein levels were evaluated using ELISA. Results: The remifentanil and dexmedetomidine groups had similar heart rate, arterial pressure, intraoperative blood loss, surgery time, and VAS scores. The extubation time was longer with remifentanil. Adropin mRNA level was higher in remifentanil at all time points. At T2, the eNOS mRNA level was higher in the remifentanil group. In the dexmedetomidine group, adropin mRNA levels decreased at T2 compared to T1. Adropin protein levels were higher in the remifentanil group at T2 and T3. In the dexmedetomidine group, serum adropin levels decreased at T3 compared to those at T1. Preoperative VAS scores in patients receiving both remifentanil and dexmedetomidine were higher than postoperative VAS scores. No significant correlation was observed between VAS scores and adropin levels or between intraoperative blood loss and adropin protein levels. Conclusions: Both drugs demonstrated similar effects on the hemodynamics of the patients, and adropin levels were not associated with the VAS score and intraoperative blood loss. These findings suggest that dexmedetomidine mediates vasodilation through adropin-independent mechanisms, while remifentanil may provide more favorable surgical conditions through adropin in patients undergoing unilateral single-level lumbar microdiscectomy.

Brain-acting hepatokines: its impact on energy balance and metabolism

The liver is recognized for its central role in energy metabolism, yet emerging evidence highlights its function as an endocrine organ, secreting a variety of proteins-hepatokines-that influence distant tissues. Hepatokines not only regulate metabolic processes by acting on peripheral tissues but also exert direct effects on brain function. In this mini-review, we discuss the existing literature on the role of "brain-acting" hepatokines including IGF-1, FGF21, LEAP2, GDF15, and ANGPTLs, and their impact on energy balance and metabolism. We review the existing evidence regarding their roles in metabolism through their action in the brain, and their potential implications in metabolic disturbances. By integrating insights from recent studies, we aim to provide a comprehensive understanding of how liver-derived signals can modulate energy balance and metabolism.

An Increase of Adropin Can Predict Depression Improvement

Objectives Depression is characterized by a lack of energy, social withdrawal, and fatigue, and it is also associated with increased inflammation in the brain. Some studies suggest that adropin may have anti-inflammatory effects and could reduce the inflammatory processes contributing to depression.

METHODS

We included 54 newly diagnosed patients experiencing their first episode of depression and 56 healthy volunteers in this study. The participants with depression were divided into three subgroups based on DSM-5 and BDI-II criteria. The focus of the study was to compare adropin levels between depressive patients and healthy volunteers, as well as to monitor changes in adropin levels after six months of treatment for depressive patients.

RESULTS

Initial measurements showed no significant differences in standard laboratory parameters or adropin levels between the depression and control groups. However, adropin and vitamin D levels increased in the group of depressive patients during the six-month follow-up.

CONCLUSIONS

Our research indicates that adropin plays a significant role in the development of depression and may influence the effectiveness of depression treatments.

Adropin: A cardio-metabolic hormone in the periphery, a neurohormone in the brain?

Whole-body metabolic homeostasis is regulated by physiological responses across organs and tissues to proteins and peptides (<50 amino acids) released into the interstitial and circulatory spaces. These secreted factors integrate signals of metabolic status at both the cellular and systemic level, regulate the intake and distribution of ingested and stored energy substrates across tissues, and minimize toxicity from excessive excursions in circulating concentrations of energy substrates (for example, glucotoxicity and lipotoxicity). The proteins and peptides that are known to be secreted into circulation that are involved in regulating metabolic processes represent a fraction of the secretome predicted by the Human Proteome Atlas. Many undiscovered leads for targeting new therapies for metabolic diseases may therefore exist. In this review, we discuss the biology of adropin, the peptide encoded by the Energy Homeostasis Associated (ENHO) gene. First described as a feeding-responsive, liver-secreted peptide ("hepatokine") involved in metabolic homeostasis, > 2 decades of research indicate adropin is a stress-responsive peptide acting across multiple tissues, vascular, and organ systems. Adropin modulates the responses of liver and muscle to insulin and glucagon in regulating glucose homeostasis. Adropin inhibits hepatic glucose production and stimulates glycolysis but also inhibits tissue fibrosis and maintains vascular health in aging and metabolic disease states. Adropin is also highly expressed in the central nervous system where recent data suggest neuroprotective actions. Collectively, these results suggest the potential for targeting adropin in reducing risk of both metabolic (metabolic syndrome/type-2 diabetes) and neurodegenerative diseases in the context of aging and obesity.

Hepatokines and their role in cardiohepatic interactions in heart failure

Heart failure is one of the leading causes of death and disease worldwide. It is a condition that affects multiple systems within the body. There is a large body of evidence supporting that the liver is a major organ involved in the pathogenesis of heart failure. Cardiac hepatopathy and cirrhotic cardiomyopathy are two conditions that are associated with poor clinical outcomes in patients with heart failure. Despite the extensive proposed explanations of the mechanisms entailing heart failure, there remains a gap in the role of proteins and metabolic regulators produced by hepatocytes and their effect on the development, progression, and prognosis of heart failure, including adverse cardiac remodeling, fibrosis, cardiac cachexia, and renal dysfunction associated with heart failure. The aim of this review is to identify the major hepatokines being studied (adropin, fetuin-A, fetuin-B, FGF-21, selenoprotein P and α1-microglobulin) as modulators of metabolic homeostasis and cardiac dysfunction in heart failure. Research suggests that these factors play a role in modulating oxidative stress, fibrosis, apoptosis, inflammatory responses, immune cell activation, mitochondrial dysfunction, and cellular migration. The exact role of each of these hepatokines is under on-going research and requires more investigations for future clinical use.

Effect of Gamma Rays on Adropin as a Potential Hepatokine Marker for Liver Damage in Male Albino Rats

Purpose

This work was the first study to show the impact of γ- radiation on adropin levels in the serum and liver tissue of male albino rats.

Methods

Liver tissue and blood samples of rats were collected at 1, 3, 7 and 14 days after whole-body exposure to 7.5 Gy of γ-radiation.

Results

Irradiated groups revealed a marked decrease in adropin associated with a significant increase in STAT3 in the serum and gene expression. Furthermore, lipid profile (cholesterol, T.G, HDL, LDL, VLDL), liver function (AST, ALT, albumin and total protein), complete blood count (RBCs, WBCs, PLT, Hb, Hct%, MCH, MCV, WBCs differential), glucose and insulin were exhibited more noticeable alterations at all time periods of the experiment. In addition, data exhibited an obvious elevation in some inflammatory markers (IL-6) and TOS accompanied by a decline in the TAC.

Conclusion and future scope of work

γ- radiation has adverse effects on adropin that related inversely with STAT3, leading to further damage to liver cells as well as disturbances in lipid and glucose metabolism. Therefore, adropin could be used in people exposed to radiation such radiotherapy to control the serious effects of radiation. Further study is needed to confirm these results.

The Emerging Role of Adropin in Neurological Health: A Systematic Review

Background

Adropin, a peptide hormone has role in various various physiological processes, including metabolic regulation and cardiovascular health. This systematic review aimed to synthesize findings from observational studies on the involvement of adropin in neurological disorders and cognitive performance.

Methods

An extensive literature search was conducted across PubMed, Scopus, Web of Science, Embase, CORE, and Google Scholar using terms such as "adropin," "Neurological Disorders," "cognitive function," "Alzheimer's disease," "Parkinson's disease," "cognition," and "brain function." Studies published from 2020 to 2024 were selected and reviewed. The search and selection process adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Out of 127 screened articles, 5 met the inclusion criteria for this review.

Results

The combined research findings suggest a consistent link between decreased adropin levels and a range of neurological disorders and cognitive impairments. In particular, reduced adropin levels were seen in individuals with dementia, cognitive impairment, bipolar disorder, Parkinson's disease, and multiple sclerosis. These findings highlight adropin's potential role in modulating neurological health and cognitive function.

Conclusion

This systematic review underscores the importance of adropin in neurological health and its potential as a therapeutic agent. Based on the observed connections, adropin might serve as a new focus for treating neurological disorders, prompting the need for more research and trials.

Adropin as a protective agent against renal ischemia-reperfusion injury induced by suprarenal aortic cross-clamping in rats

BACKGROUND

The development of protective therapeutic strategies against acute kidney injury associated with suprarenal aneurysms, renal artery occlusive disease, and suprarenal aortic reconstruction is of paramount importance. Adropin is a peptide hormone that has been shown to protect vascular endothelial cells and reduce oxidative stress, apoptosis, and inflammation. Therefore, in addition to its metabolic and vascular effects, adropin has potential as a therapeutic agent in renal ischemia-reperfusion injury. This study aims to investigate the protective effects of adropine on kidney ischemia-reperfusion (IR) injury under the suprarenal aortic cross clamp.

METHODS

Male Sprague Dawley rats were divided into six groups, with seven rats in each group for the study design. The control and ischemia reperfusion (IR) induced groups were designated as the two groups while the other four groups (TR1 to TR4 ) were administered varying doses of adropin at 0.5 mg/kg, 1 mg/kg, 1.5 mg/kg, and 2 mg/kg for each group. After a 60 min ischemic period, a 24-hour reperfusion period was implemented to assess the outcomes of adropin treatment on renal IR. Histopathological analysis was performed in conjunction with determination of apoptosis, and malondialdehyde (MDA) levels. In addition, serum concentrations of adropin, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), as well as endothelial nitric oxide synthase (eNOS) were measured in order to further define the biochemical reactions of the treatment.

RESULTS

MDA levels were significantly elevated in the IR group compared to the control group, while the activities of eNOS, SOD, and GSH-Px enzymes were significantly decreased (P < 0.05). MDA levels in the treatment groups were lower than those in the IR group, whereas eNOS, SOD, and GSH-Px levels were higher (P < 0.05). Statistically, the lowest adropin levels were observed in the IR group, while the highest levels were noted in the TR4 group (P < 0.05). Histopathological examination revealed a reduction in tissue damage in the treatment groups compared to the IR group.

CONCLUSION

The histological and biochemical findings from this study indicate that adropin provides protective effects against renal ischemia-reperfusion injury in a dose-dependent manner.

Adropin-Driven Browning: Targeting M2 Macrophages to Combat PCOS

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age, associated with chronic low-grade inflammation and metabolic disorders. The exact pathogenesis of PCOS remains unclear. Adropin, a secreted protein encoded by the energy homeostasis gene (Enho), has immunometabolic regulatory functions. In the present study, the serum levels of adropin were significantly lower (P < 0.001) in PCOS mice than controls, and adropin deficiency exacerbated the obesity and inflammatory phenotypes in letrozole (LTZ)-induced PCOS mice. In vitro experiments, it has shown that adropin mediated the phenotypic change of RAW264.7 macrophages to M2 through upregulation of heme oxygenase-1 (HO-1), and then adropin-treated macrophage-conditioned medium (Adr-CM) induced browning of fully differentiated 3T3-L1 adipocytes. Finally, vivo experiments by injecting adropin into PCOS model mice showed that adropin treatment significantly reduced body weight, and promoted macrophage M2 anti-inflammatory phenotypic transformation and browning of white adipose tissue. In summary, the present study reveals a novel mechanism by which adropin indirectly promotes adipose tissue browning by regulating macrophage polarisation, which provides a new perspective and experimental basis for the therapeutic strategy of PCOS and its related metabolic disorders.

Serum adropin levels as a potential biomarker for predicting diabetic kidney disease progression

Background

To investigate the value of serum adropin in predicting chronic kidney disease (CKD) progression in subjects with type 2 diabetes (T2D).

Materials and methods

Serum adropin levels were measured in normal control and T2D patients with various stage of CKD. CKD progression was defined as ≥ 30% decline from the baseline estimated glomerular filtration rate. Logistic regression analysis was applied to assess the association between adropin levels and CKD progression.

Results

The study included 58 subjects with T2D (18 early CKD and 40 advanced CKD) and 9 subjects without diabetes (control). Subjects with T2D had significantly higher adropin levels than controls (6393.10 ± 1611.84 vs. 3470.30 ± 1284.41 pg/ml; P < 0.001). Meanwhile, T2D patients with advanced CKD had higher adropin levels than those with early CKD (6848.89 ± 1287.04 vs. 5380.25 ± 1826.44 pg/ml; P = 0.003). Among T2D patients, subjects experienced CKD progression had higher adropin levels than those without (7520.15 ± 843.21 vs. 6151.16 ± 1661.61 pg/mL, P =0.003). Thus, adropin predicts CKD progression in T2D patients with 86% sensitivity and 70% specificity at 6872.24 pg/ml cutoff value. The association with CKD progression was still significant after adjusting for age, gender and body mass index (adjusted odds ratio = 27.188, 95% confidence interval 1.415-522.527, P =0.029).

Conclusions

The above findings suggest that serum adropin could be applied as a potential biomarker for predicting CKD progression in subjects with T2D. Further research is needed to validate these results and explore the underlying mechanisms.

Predictive biomarkers for cardiometabolic risk in postmenopausal women: insights into visfatin, adropin, and adiponectin

Background

Visfatin, adropin, and adiponectin are involved in many changes associated with obesity and metabolic disorders, and may be related to metabolic syndrome and cardiovascular disease. The selection of visfatin, adropin, and adiponectin as biomarkers is based on their significant roles in metabolic regulation and inflammation, which are critical factors in cardiometabolic risk. Visfatin is known for its pro-inflammatory properties and its ability to modulate insulin resistance. Adropin is involved in energy homeostasis and metabolic health, while adiponectin has anti-inflammatory and insulin-sensitizing effects. During the perimenopausal period, the risk of obesity, and consequently cardiometabolic diseases increases. Therefore, the aim of this study was to assess the relationship between cardiometabolic parameters and circulating levels of visfatin, adropin, and adiponectin in perimenopausal women with regard to their obesity status.

Materials and methods

This study of 168 perimenopausal women utilized a cross-sectional design with non-random sampling. It involved the use of questionnaires, as well as anthropometric and blood pressure measurements. Blood samples were collected to determine the levels of visfatin, adropin, and adiponectin. Statistical analyses, including correlation coefficients, were performed to evaluate the relationship between these biomarkers and cardiometabolic risk factors, such as insulin resistance, lipid profiles, and inflammatory markers.

Results

In our study, visceral adiposity index and lipid accumulation product negatively correlated with adiponectin levels. Preliminary multivariate linear regression analysis revealed a positive correlation between circulating visfatin and IL-6 levels. Circulating adropin negatively correlated with HbA1C, fasting blood glucose, and insulin. Adiponectin negatively correlated with HbA1C, fasting blood glucose, insulin, and triglycerides. Furthermore, circulating adiponectin positively correlated with HDL, and negatively with HOMA-IR.

Conclusions

Adiponectin is a promising biomarker for predicting cardiometabolic risk in postmenopausal women.

Adropin: a key player in immune cell homeostasis and regulation of inflammation in several diseases

Adropin is a secreted peptide encoded by the energy homeostasis-associated gene (ENHO), located chromosome 9p13.3, with a conserved amino acid sequence across humans and mice. Its expression is regulated by various factors, including fat, LXRα, ERα, ROR, and STAT3. Adropin plays a critical role in glucose and lipid metabolism, as well as insulin resistance, by modulating multiple signaling pathways that contribute to the reduction of obesity and the improvement of blood lipid and glucose homeostasis. Additionally, it influences immune cells and inflammation, exerting anti-inflammatory effects across various diseases. While extensive research has summarized the regulation of cellular energy metabolism by adropin, limited studies have explored its role in immune regulation and inflammation. To enhance the understanding of adropin's immune-modulating and anti-inflammatory mechanisms, this review synthesizes recent findings on its effects in conditions such as atherosclerosis, diabetes, fatty liver, non-alcoholic hepatitis, and inflammation. Furthermore, the review discusses the current research limitations and outlines potential future directions for adropin-related investigations. It is hoped that ongoing research into adropin will contribute significantly to the advancement of medical treatments for various diseases.

Association between Mediterranean diet and metabolic health status among adults was not mediated through serum adropin levels

BACKGROUND

Prevalence of metabolic disorders has been increased in recent years around the world. The relationship between Mediterranean diet (MD) with metabolic health status and serum adropin levels has been less examined in Iranian adults. We investigated the association between MD compliance with metabolic health status and adropin hormone in Iranian adults.

METHODS

This observational study was conducted on 527 men and women. Food intakes were evaluated by a validated food frequency questionnaire. Blood pressure and anthropometric parameters were measured. Fasting blood samples were drawn to measure serum adropin concentrations, blood glucose, triglycerides, high-density lipoprotein cholesterol, high sensitive C-reactive protein and insulin. Metabolic unhealthy (MU) status was defined as having ≥ 2 cardio-metabolic risk factors.

RESULTS

After adjustments for potential confounders, subjects in highest versus lowest tertile of MD had 52% lower odds of MU status (OR = 0.48, 95%CI: 0.23-0.97). Stratified analysis revealed a significant association in normal-weight participants (OR = 0.12; 95%CI: 0.02-0.64), but not in those with overweight/obesity (OR = 0.66, 95%CI: 0.27-1.57). By excluding each component of MD, the association disappeared, except for three components (vegetables, nuts and grains). MD adherence was not significantly related to serum adropin levels in multivariable-adjusted model (unstandardized B= -0.19, 95%CI: -4.97, 4.59; P = 0.94). Serum adropin hormone levels were also not substantially different among metabolic healthy versus unhealthy subjects (P = 0.66).

CONCLUSIONS

This cross-sectional study showed an inverse association between adherence to MD and odds of MU status, especially in subjects with normal-weight. Serum adropin concentrations were not associated with MD adherence or metabolic health status.

Serum adropin is unaltered in adolescents with histology-confirmed steatotic liver disease

OBJECTIVES

Metabolic dysfunction-associated steatotic liver disease (MASLD) in adolescents is increasing. Adropin is a liver-derived peptide involved in glucose and lipid homeostasis that was shown to be reduced in adults with metabolic disorders and cardiovascular disease (CVD). Serum adropin may also be higher in young men than women. A prior study reported that serum adropin was reduced in adolescents with MASLD, but the relationship between liver histology and CVD risk factors was not reported. We tested the hypotheses that adropin is (1) reduced in adolescents with MASLD compared to adolescents with obesity (Ob) or normal weight (NW) without MASLD, (2) correlated with blood pressure (BP), arterial stiffness, and liver histopathology, and (3) higher in boys than girls.

METHODS

Serum adropin was measured in 47 patients with MASLD, and 27 and 29 control participants with Ob or NW, respectively.

RESULTS

Adropin was not reduced but was instead 5% and 20% higher (p > 0.42) in the MASLD compared to the Ob and NW groups, respectively. Adropin concentration was not correlated with arterial stiffness or BP. Adropin was 20% higher in boys than girls in the entire study cohort (p = 0.034). This difference was evident in the Ob group (p = 0.018), but not in the NW (p = 0.537) or the MASLD (p = 0.893) groups. Adropin was positively correlated with age within the MASLD group only (r = 0.46, p < 0.001).

CONCLUSION

Serum adropin was not reduced in adolescents with Ob or MASLD as reported previously. The positive relationship between age and adropin in adolescents with MASLD requires further examination.

Adropin exerts neuroprotection in an experimental rat model of Parkinson's disease

Objectives

This study was planned to elucidate the mechanism of the protective effect of adropin in an experimental rat model of Parkinson's Disease (PD).

Materials and Methods

Three-month-old male Wistar rats were randomly divided into four groups: i) Control, ii) Sham, iii) PD, and iv) PD+Adropin. The performance tests were performed seven days after the 6-Hydroxydopamine hydrochloride (6-OHDA) injection into the striatum. The immunoreactivities for tyrosine hydroxylase (TH), G protein-coupled receptor 19 (GPR19), and vascular endothelial growth factor receptor 2 (VEGFR2) were detected by immunohistochemistry (IHC) in the substantia nigra (SN). Dopamine levels were measured by mass spectrometry. Glycogen synthase kinase 3β (GSK3β) and pGSK3β (Ser9) protein levels were evaluated by western blot analysis.

Results

Our study demonstrated that motor performances were significantly improved by adropin treatment. Central adropin injection prevented the loss of nigral dopaminergic neurons and induced VEGFR2 expression but not GPR19 compared to the PD group. The ratio of p-GSK3β/GSK3β did not differ between groups. However, the level of dopamine in SN was increased with adropin injection in the PD+Adropin group.

Conclusion

Our findings reveal that adropin administration has a protective effect on nigral dopaminergic neurons and acts through the VEGFR2 signaling pathway.

Adropin/Tirzepatide Combination Mitigates Cardiac Metabolic Aberrations in a Rat Model of Polycystic Ovarian Syndrome, Implicating the Role of the AKT/GSK3β/NF-κB/NLRP3 Pathway

Polycystic ovarian syndrome (PCOS) is a multifaceted metabolic and hormonal disorder in females of reproductive age, frequently associated with cardiac disturbances. This research aimed to explore the protective potential of adropin and/or tirzepatide (Tirze) on cardiometabolic aberrations in the letrozole-induced PCOS model. Female Wistar non-pregnant rats were allotted into five groups: CON; PCOS; PCOS + adropin; PCOS + Tirze; and PCOS + adropin+ Tirze. The serum sex hormones, glucose, and lipid profiles were securitized. Cardiac phosphorylated levels of AKT(pAKT), glycogen synthase kinase-3 beta (pGSK-3β), NOD-like receptor family pyrin domain containing 3 (NLPR3), IL-1β and IL-18 were assayed. The cardiac redox status and endoplasmic reticulum stress (ER) parameters including relative glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) gene expressions were detected. Finally, the immunoreactivity of cardiac NF-κB, Bcl2, and BAX were assessed. Our results displayed that adropin and/or Tirze intervention successfully alleviated the PCOS-provoked cardiometabolic derangements with better results recorded for the combination treatment. The synergistic effect of adropin and Tirze is mostly mediated via activating the cardiac Akt, which dampens the GSK3β/NF-κB/NLRP3 signaling pathway, with a sequel of alleviating oxidative damage, inflammatory response, ER stress, and related apoptosis, making them alluring desirable therapeutic targets in PCOS-associated cardiac complications.

Evaluation of Selected Pro- and Anti-Inflammatory Adipokines in Colostrum from Mothers with Gestational Diabetes Mellitus

Adipokines related to gestational diabetes mellitus (GDM) are an emerging area of interest. The aim of this study was to evaluate the associations between GDM and adipokine levels in human milk. This was an observational cohort study targeting mothers with gestational diabetes, which evaluated the association of maternal hyperglycemia severity, classified as GDM-G1 (diet treatment) and GDM-G2 (insulin treatment), with colostral adipokines involved in pro- and anti-inflammatory processes. Colostrum was collected from hyperglycemic (N = 34) and normoglycemic (N = 26) mothers, and adipokine levels were determined by immunoenzymatic assay. Among anti-inflammatory adipokines, only for irisin and vaspin, but not for obestatin and adropin, were significantly different levels noted between the GDM-G1, GDM-G2 and non-GDM cohorts. Colostrum of the GDM-G2 subgroup contained more vaspin (4.77 ng/mL) than that of normoglycemic mothers (3.12 ng/mL) and more irisin (26.95 μg/mL) than in the GDM-G1 subgroup (17.59 μg/mL). The levels of pro-inflammatory adipokines, namely, dermcidin, chemerin and visfatin, were at similar levels irrespective of maternal glycemia. Moreover, irisin showed a negative correlation with dermcidin in GDM-G2 and non-GDM cohorts. Associations were observed between colostral irisin and maternal preconception BMI, dermcidin and gestational age, and vaspin and maternal age. This study provides evidence that the way of restoring glucose homeostasis in pregnant women has an impact on the anti-inflammatory adipokines irisin and vaspin, but not on obestatin and adropin. GDM, regardless of severity, did not influence the colostral pro-inflammatory adipokines visfatin, chemerin and dermcidin.

Role of the Unique Secreted Peptide Adropin in Various Physiological and Disease States

Adropin, a secreted peptide hormone identified in 2008, plays a significant role in regulating energy homeostasis, glucose metabolism, and lipid metabolism. Its expression is linked to dietary macronutrient intake and is influenced by metabolic syndrome, obesity, diabetes, and cardiovascular diseases. Emerging evidence suggests that adropin might be a biomarker for various conditions, including metabolic syndrome, coronary artery disease, and hypertensive disorders complicating pregnancy. In cerebrovascular diseases, adropin demonstrates protective effects by reducing blood-brain barrier permeability, brain edema, and infarct size while improving cognitive and sensorimotor functions in ischemic stroke models. The protective effects of adropin extend to preventing endothelial damage, promoting angiogenesis, and mitigating inflammation, making it a promising therapeutic target for cardiovascular and neurodegenerative diseases. This review provides a comprehensive overview of adropin's multifaceted roles in physiological and pathological conditions, as well as our recent work demonstrating adropin's role in subarachnoid hemorrhage-mediated neural injury and delayed cerebral infarction.

Adropin regulates macrophage phenotype via PPARγ signalling: A preliminary study of adropin and Crohn's disease

Macrophage polarization is increasingly recognized as a vital pathogenetic factor in Crohn's disease (CD). Adropin is a secreted protein implicated in energy homeostasis, chiefly linked to glucose and lipid metabolism. However, the significance of adropin in CD is not clear. The objective of this study was to detect the expression of adropin in CD patients and investigate the effect of adropin on macrophage polarization induced by lipopolysaccharide (LPS) and its potential mechanism. Our study showed that serum adropin levels were markedly lower in patients with CD in active (CDA) than patients with CD in remission (CDR) and control groups (p < 0.01), however, there was no significant difference between in remission CD and healthy controls (p > 0.05). The colon mucous adropin levels in CDA were distinctly higher than CDR and controls (p < 0.01), while a significant difference between in remission CD and in healthy controls was not observed (p > 0.05). Exploration of the specific mechanism of action indicated that adropin promoted LPS-induced RAW264.7 macrophage polarization to M2 phenotype by modulating the expression and nuclear translocation of peroxisome proliferator receptor gamma (PPARγ), which may help weaken the intestinal inflammatory response. PPARγ inhibitor GW9662 reversed adropin-induced M2 macrophage polarization. Knockdown of GPR19, an adropin receptor, abrogated the M2 macrophage polarization caused by PPARγ. These findings suggest that adropin in colonic mucosa is a protective response in patients with active Crohn's disease.

Explore key genes of Crohn's disease based on glycerophospholipid metabolism: A comprehensive analysis Utilizing Mendelian Randomization, Multi-Omics integration, Machine Learning, and SHAP methodology

BACKGROUND AND AIMS

Crohn's disease (CD) is a chronic, complex inflammatory condition with increasing incidence and prevalence worldwide. However, the causes of CD remain incompletely understood. We identified CD-related metabolites, inflammatory factors, and key genes by Mendelian randomization (MR), multi-omics integration, machine learning (ML), and SHAP.

METHODS

We first performed a mediation MR analysis on 1400 serum metabolites, 91 inflammatory factors, and CD. We found that certain phospholipids are causally related to CD. In the scRNA-seq data, monocytes were categorized into high and low metabolism groups based on their glycerophospholipid metabolism scores. The differentially expressed genes of these two groups of cells were extracted, and transcription factor prediction, cell communication analysis, and GSEA analysis were performed. After further screening of differentially expressed genes (FDR<0.05, log2FC>1), least absolute shrinkage and selection operator (LASSO) regression was performed to obtain hub genes. Models for hub genes were built using the Catboost, XGboost, and NGboost methods. Further, we used the SHAP method to interpret the models and obtain the gene with the highest contribution to each model. Finally, qRT-PCR was used to verify the expression of these genes in the peripheral blood mononuclear cells (PBMC) of CD patients and healthy subjects.

RESULT

MR results showed 1-palmitoyl-2-stearoyl-gpc (16:0/18:0) levels, 1-stearoyl-2-arachidonoyl-GPI (18:0/20:4) levels, 1-arachidonoyl-gpc (20:4n6) levels, 1-palmitoyl-2-arachidonoyl-gpc (16:0/20:4n6) levels, and 1-arachidonoyl-GPE (20:4n6) levels were significantly associated with CD risk reduction (FDR<0.05), with CXCL9 acting as a mediation between these phospholipids and CD. The analysis identified 19 hub genes, with Catboost, XGboost, and NGboost achieving AUC of 0.91, 0.88, and 0.85, respectively. The SHAP methodology obtained the three genes with the highest model contribution: G0S2, S100A8, and PLAUR. The qRT-PCR results showed that the expression levels of S100A8 (p = 0.0003), G0S2 (p < 0.0001), and PLAUR (p = 0.0141) in the PBMC of CD patients were higher than healthy subjects.

CONCLUSION

MR findings suggest that certain phospholipids may lower CD risk. G0S2, S100A8, and PLAUR may be potential pathogenic genes in CD. These phospholipids and genes could serve as novel diagnostic and therapeutic targets for CD.

Hepatokines: unveiling the molecular and cellular mechanisms connecting hepatic tissue to insulin resistance and inflammation

Insulin resistance arising from Non-Alcoholic Fatty Liver Disease (NAFLD) stands as a prevalent global ailment, a manifestation within societies stemming from individuals' suboptimal dietary habits and lifestyles. This form of insulin resistance emerges as a pivotal factor in the development of type 2 diabetes mellitus (T2DM). Emerging evidence underscores the significant role of hepatokines, as hepatic-secreted hormone-like entities, in the genesis of insulin resistance and eventual onset of type 2 diabetes. Hepatokines exert influence over extrahepatic metabolism regulation. Their principal functions encompass impacting adipocytes, pancreatic cells, muscles, and the brain, thereby playing a crucial role in shaping body metabolism through signaling to target tissues. This review explores the most important hepatokines, each with distinct influences. Our review shows that Fetuin-A promotes lipid-induced insulin resistance by acting as an endogenous ligand for Toll-like receptor 4 (TLR-4). FGF21 reduces inflammation in diabetes by blocking the nuclear translocation of nuclear factor-κB (NF-κB) in adipocytes and adipose tissue, while also improving glucose metabolism. ANGPTL6 enhances AMPK and insulin signaling in muscle, and suppresses gluconeogenesis. Follistatin can influence insulin resistance and inflammation by interacting with members of the TGF-β family. Adropin show a positive correlation with phosphoenolpyruvate carboxykinase 1 (PCK1), a key regulator of gluconeogenesis. This article delves into hepatokines' impact on NAFLD, inflammation, and T2DM, with a specific focus on insulin resistance. The aim is to comprehend the influence of these recently identified hormones on disease development and their underlying physiological and pathological mechanisms.

Ultra-processed foods intake in relation to metabolic health status, serum brain-derived neurotrophic factor and adropin levels in adults

BACKGROUND

In recent years, there has been a lot of discussion over the impact of ultra-processed foods (UPFs) intake on overall health of subjects. However, the association between UPFs intake and metabolic unhealthy (MU) status is still in a state of ambiguity. The current study assessed the relationship between UPFs intake and MU status with regard to brain-derived neurotrophic factor (BDNF) and adropin levels.

METHODS

A sample of Iranian adults (aged 20-65 years) was selected to participate in this cross-sectional study using a multistage cluster random-sampling method. UPFs intake was assessed by a validated food frequency questionnaire and NOVA classification. Concentrations of metabolic parameters, BDNF and adropin were determined through fasting blood samples. MU status was assessed according to the criteria proposed by Wildman.

RESULTS

The overall prevalence of MU phenotype among study participants (n = 527) was 42.5%. Higher intake of UPFs was associated with elevated odds of MU status in multivariable-adjusted model (ORT3 vs. T1=1.88; 95%CI: 1.02-3.45). Moreover, a positive association was observed between UPFs intake and hypertriglyceridemia after controlling all confounders (ORT3 vs. T1=2.07; 95%CI: 1.15-3.73). However, each tertile increase in UPFs intake was not significantly associated with serum BDNF ([Formula: see text]=0.15; 95%CI: -0.05, 0.34; P = 0.14) and adropin ([Formula: see text]=-1.37; 95%CI: -6.16, 3.42; P = 0.58) levels in multivariable-adjusted linear regression models.

CONCLUSION

Our findings suggested that higher consumption of UPFs was related to increased likelihood of MU status among a sample of Iranian adults. Further longitudinal studies are needed to verify the directionality and generalizability of the results to all adult populations.

Adropin promotes testicular functions by modulating redox homeostasis in adult mouse

PURPOSE

Adropin is an emerging metabolic hormone that has a role in regulating energy homeostasis. The present study aimed to explore the impact of adropin on redox homeostasis and its possible role in testicular functions in adult mouse testis.

METHODS

Western blot, flow-cytometry, and TUNEL assay were performed to explore the impact of intra-testicular treatment of adropin (0.5 μg/testis) on testicular functions of adult mice. Hormonal assay was done by ELISA. Further, antioxidant enzyme activities were measured.

RESULTS

Adropin treatment significantly increased the sperm count and testicular testosterone by increasing the expression of GPR19 and steroidogenic proteins. Also, adropin treatment reduced the oxidative/nitrosative stress by facilitating the translocation of NRF2 and inhibiting NF-κB into the nucleus of germ cells. Enhanced nuclear translocation of NRF2 leads to elevated biosynthesis of antioxidant enzymes, evident by increased HO-1, SOD, and catalase activity that ultimately resulted into declined LPO levels in adropin-treated mice testes. Furthermore, adropin decreased nuclear translocation of NF-κB in germ cells, that resulted into decreased NO production leading to decreased nitrosative stress. Adropin/GPR19 signaling significantly increased its differentiation, proliferation, and survival of germ cells by elevating the expression of PCNA and declining caspase 3, cleaved caspase 3 expression, Bax/Bcl2 ratio, and TUNEL-positive cells. FACS analysis revealed that adropin treatment enhances overall turnover of testicular cells leading to rise in production of advanced germ cells, notably spermatids.

CONCLUSION

The present study indicated that adropin improves testicular steroidogenesis, spermatogenesis via modulating redox potential and could be a promising target for treating testicular dysfunctions.

Unveiling the multifaceted role of adropin in various diseases (Review)

Adropin is a secreted peptide encoded by the energy homeostasis‑associated gene, which also functions as a membrane‑bound protein facilitating intercellular communication. This peptide has been detected in various tissues and body fluids, including the brain, liver, kidney, heart, pancreas, small intestine, endothelial cells and colostrum. Notably, the amino acid sequences of adropin are identical in humans, mice and rats. Previous studies have demonstrated that adropin levels fluctuate under different physiological and pathological conditions. Adropin plays a role in regulating carbohydrate metabolism, lipid metabolism and intercellular molecular signaling pathways, implicating its involvement in the progression of numerous diseases, such as acute myocardial infarction, lung injury, non‑alcoholic fatty liver disease/non‑alcoholic steatohepatitis, kidney disease, polycystic ovary syndrome, obesity, and diabetes, atherosclerosis, systemic sclerosis and cancer. Despite its significance, the precise role and mechanism of this protein remain inadequately understood and studied. To elucidate the function of adropin and its clinical research status, a systematic review of recent studies on adropin across various diseases was conducted. Additionally, several challenges and limitations associated with adropin research in both animal and clinical contexts were identified, aiming to offer valuable insights for future investigation.

Investigating the Effect of a Multicomponent Exercise Program on Adropin, Endothelial Function, Insulin Resistance, and Sleep Quality in Overweight Older Adults (a Link With Physiological Indexes and Sleep Quality): Results of a Randomized Controlled Study

The aim of the present study was to investigate the effects of multicomponent training on adropin, endothelial function, insulin resistance, and sleep quality in overweight older adults. In this randomized controlled study, 40 overweight older adults were randomly divided into training and control groups. The multicomponent training program including aerobic, resistance, and balance exercise was followed for 8 weeks, 3 days a week. Study variables were measured 48 hr before and after the intervention. After 8 weeks of multicomponent training, adropin (p = .01), nitric oxide (p = .01), and maximal oxygen uptake (VO2max; p = .002) increased, and glucose (p = .001), insulin (p = .001), insulin resistance (p = .01), systolic blood pressure (p = .01), and sleep disorders (p = .01) decreased significantly. Also, Pearson's test results showed a significant inverse relationship between adropin level (p = .01 and r = -.55) and glucose (p = .01 and r = -.51) with sleep disorders. It seems that multicomponent training increases adropin and improves insulin resistance, endothelial function, and sleep quality in older adults.

Adropin Is Expressed in Pancreatic Islet Cells and Reduces Glucagon Release in Diabetes Mellitus

Diabetes mellitus affects 537 million adults around the world. Adropin is expressed in different cell types. Our aim was to investigate the cellular localization in the endocrine pancreas and its effect on modulating pancreatic endocrine hormone release in streptozotocin (STZ)-induced diabetic rats. Adropin expression in the pancreas was investigated in normal and diabetic rats using immunohistochemistry and immunoelectron microscopy. Serum levels of insulin, glucagon pancreatic polypeptide (PP), and somatostatin were measured using a Luminex® χMAP (Magpix®) analyzer. Pancreatic endocrine hormone levels in INS-1 832/3 rat insulinoma cells, as well as pancreatic tissue fragments of normal and diabetic rats treated with different concentrations of adropin (10-6, 10-9, and 10-12 M), were measured using ELISA. Adropin was colocalized with cells producing either insulin, glucagon, or PP. Adropin treatment reduced the number of glucagon-secreting alpha cells and suppressed glucagon release from the pancreas. The serum levels of GLP-1 and amylin were significantly increased after treatment with adropin. Our study indicates a potential role of adropin in modulating glucagon secretion in animal models of diabetes mellitus.

The Evaluation of Adropin and Autotaxin as Potential Markers of Endothelial Dysfunction in Preeclampsia

Endothelial dysfunction (ED) plays a prominent role in the pathogenesis of preeclampsia (PE). There is a need for non-invasive methods to assess endothelial function in preeclamptic patients. In the present study, adropin, autotaxin (ATX), and lysophosphatidic acid (LPA) were evaluated as indicators of ED. Patients diagnosed with PE and healthy pregnant women (n = 42 for each group) were compared. After measuring flow-mediated dilation (FMD), the participants were stratified as ED (+) or ED (-) based on a cut-off value of 6.5%. The PE patients were divided as early/late onset PE and severe/mild PE. Adropin, ATX, and LPA levels were measured, and their relevance to ED was evaluated. Student t, Mann-Whitney U, or ANOVA tests were used for statistics, as appropriate. Adropin levels were diminished in the ED (+) group, whereas ATX and LPA levels were increased. The decrease in adropin levels was more pronounced in severe PE, showing a positive correlation with the FMD. In the logistic regression model, adropin was the only parameter that was an independent variable for the FMD test (P < .001). Adropin measurements in serum may be of value for disease follow-up in patients with PE.

Correlation between Serum Levels of Nitric Oxide and Adropin and Erectile Dysfunction in Males with Nonalcoholic Fatty Liver Disease: An Observational Study

The current study aimed to evaluate the serum levels of nitric oxide (NO) and adropin in males with non-alcoholic fatty liver disease (NAFLD) induced erectile dysfunction (ED) and NAFLD patients without ED and controls. The current study selected 165 participants from the hepatology department from November 2021 to November 2022. The patients were either suffering from NAFLD with normal liver functions or non-alcoholic steatohepatitis with abnormal liver functions. They were diagnosed by abdominal ultrasonography. Participants were evaluated using the validated Arabic version of the International Index of Erectile Function (ArIIEF-5), the Arabic form of the Generalized Anxiety Disorder-7 (GAD-7) questionnaire and the Patient Health Questionnaire-9 (PHQ-9). Noteworthy, there were significant positive correlations between ArIIEF-5 score, NO, adropin and total testosterone (r = 0.380, p = 0.001; r = 0.507, p =  < 0.001; r = 0.246, p = 0.038, respectively). Meanwhile, there were significant negative correlations between ArIIEF-5 score, creatinine, duration of the disease and scores of GAD-7 and PHQ-9 (r = -0.656, p =  < 0.001; r = -0.368, p = 0.002; r = -0.663, p =  < 0.001; r = -0.248, p = 0.037, respectively). Finally, a linear regression analysis revealed that GAD-7, creatinine, and adropin were the only strong independent predictors of ArIIEF-5, as the 95% confidence interval in the form of upper and lower bounds was -0.349, -0.843, p < 0.001, -6.507, -18.402, p < 0.001, 0.476, 0.117, and p 0.002, respectively. Impaired NO and adropin levels play a potential role in the development of ED in patients with NAFLD.

Adropin may regulate ovarian functions by improving antioxidant potential in adult mouse

The corpus luteum (CL) is a temporary endocrine gland that synthesizes progesterone. The luteal progesterone plays a central role in the regulation of the estrous cycle as well as the implantation and maintenance of pregnancy. Our previous study showed the expression of adropin and its receptor, GPR19, in the luteal cells and its significant role in luteinization. The aim of the present study was to investigate the in vitro effect of adropin on hCG-induced ovarian functions in adult mice. We also evaluated the effect of exogenous treatment with adropin on ovarian steroidogenesis and anti-oxidant parameters, with special emphasis on CL function. Our results demonstrated that adropin acts synergistically with hCG to promote ovarian steroidogenesis and survival by increasing the expression of StAR, 3β-HSD, and aromatase proteins and decreasing the BAX/BCL2 ratio. Exogenous adropin treatment increased progesterone production by increasing the expression of GPR19, StAR and 3β-HSD enzymes in the mouse ovary. Also, adropin inhibited the luteal oxidative stress by increasing nuclear translocation of NRF-2 in CL, which resulted in increased HO-1 expression and SOD, catalase activity. Decreased oxidative stress might inhibit the translocation of NF-κB into the nucleus of luteal cells, resulting into increased survival and decreased apoptosis, as evident by decreased lipid peroxidation, BAX/BCL2 ratio, caspase 3, active caspase 3 expression, and TUNEL-positive cells in adropin treated mice. Our findings suggest that adropin can be a promising candidate that can enhance the survivability of the CL.

Adropin: A crucial regulator of cardiovascular health and metabolic balance

Adropin, a peptide discovered in 2008, has gained recognition as a key regulator of cardiovascular health and metabolic balance. Initially identified for its roles in energy balance, lipid metabolism, and glucose regulation, adropin has also been found to improve cardiovascular health by enhancing endothelial function, modulating lipid profiles, and reducing oxidative stress. These protective mechanisms suggest that adropin may be able to help prevent conditions such as atherosclerosis, hypertension, and other cardiovascular diseases. Research has established connections between adropin and cardiovascular risk factors, such as obesity, insulin resistance, and dyslipidemia, positioning it as a valuable biomarker for evaluating cardiovascular disease risk. New studies highlight adropin's diagnostic and prognostic significance, showing that higher levels are linked to better cardiovascular outcomes, while lower levels are associated with a higher risk of cardiovascular diseases. This review aims to summarize current knowledge on adropin, emphasizing its significance as a promising focus in the intersection of cardiovascular health and metabolic health. By summarizing the latest research findings, this review aims to offer insights into the potential applications of adropin in both clinical practice and research, leading to a deeper understanding of its role in maintaining cardiovascular and metabolic health.

Adropin Predicts Asymptomatic Heart Failure in Patients with Type 2 Diabetes Mellitus Independent of the Levels of Natriuretic Peptides

In patients with type 2 diabetes mellitus (T2DM), asymptomatic adverse cardiac remodeling plays a pivotal role in the development of heart failure (HF). Patients with T2DM often have low or near-normal levels of natriuretic peptides, including N-terminal brain natriuretic peptide (NT-proBNP), which have been inconclusive in predicting the transition from asymptomatic adverse cardiac remodeling to HF with preserved ejection fraction (HFpEF). The aim of this study was to elucidate the predictive ability of adropin for HFpEF depending on the circulating levels of NT-proBNP. We prospectively enrolled 561 T2DM patients (glycated hemoglobin < 6.9%) with echocardiographic evidence of structural cardiac abnormalities and left ventricular ejection fractions >50%. All patients underwent B-mode transthoracic echocardiographic and Doppler examinations. Circulating biomarkers, i.e., NT-proBNP and adropin, were assessed at baseline. All individuals were divided into two groups according to the presence of low levels (<125 pmol/mL; n = 162) or elevated levels (≥125 pmol/mL; n = 399) of NT-proBNP. Patients with known asymptomatic adverse cardiac remodeling and elevated NT-proBNP were classified as having asymptomatic HFpEF. A multivariate logistic regression showed that low serum levels of adropin (<3.5 ng/mL), its combination with any level of NT-proBNP, and use of SGLT2 inhibitors were independent predictors of HFpEF. However, low levels of adropin significantly increased the predictive ability of NT-proBNP for asymptomatic HFpEF in patients with T2DM, even though the concentrations of NT-proBNP were low, while adropin added discriminatory value to all concentrations of NT-proBNP. In conclusion, low levels of adropin significantly increase the predictive ability of NT-proBNP for asymptomatic HFpEF in patients with T2DM.

Ameliorating effects of adropin on letrozole-induced polycystic ovary syndrome via regulating steroidogenesis and the microbiota inflammatory axis in rats

Growing evidence supports the role of gut microbiota in chronic inflammation, insulin resistance (IR) and sex hormone production in polycystic ovary syndrome (PCOS). Adropin plays a pivotal role in the regulation of glucose and lipid metabolism and is negatively correlated with IR, which affects intestinal microbiota and sex hormones. However, the effect of adropin administration in PCOS has yet to be investigated. The present study aimed to assess the effects of adropin on letrozole (LTZ)-induced PCOS in rats and the potential underlying mechanisms. The experimental groups were normal, adropin, letrozole and LTZ + adropin. At the end of the experiment, adropin significantly ameliorated PCOS, as evidenced by restoring the normal ovarian structure, decreasing the theca cell thickness in antral follicles, as well as serum testosterone and luteinizing hormone levels and luteinizing hormone/follicle-stimulating hormone ratios, at the same time as increasing granulosa cell thickness in antral follicles, oestradiol and follicle-stimulating hormone levels. The ameliorating effect could be attributed to its effect on sex hormone-binding globulin, key steroidogenic genes STAR and CYP11A1, IR, lipid profile, gut microbiota metabolites-brain-ovary axis components (short chain fatty acids, free fatty acid receptor 3 and peptide YY), intestinal permeability marker (zonulin and tight junction protein claudin-1), lipopolysaccharides/Toll-like receptor 4/nuclear factor kappa B inflammatory pathway and oxidative stress makers (malondialdehyde and total antioxidant capacity). In conclusion, adropin has a promising therapeutic effect on PCOS by regulating steroidogenesis, IR, lipid profile, the gut microbiota inflammatory axis and redox homeostasis. KEY POINTS: Adropin treatment reversed endocrine and ovarian morphology disorders in polycystic ovary syndrome (PCOS). Adropin regulated the ovarian steroidogenesis and sex hormone-binding globulin in PCOS. Adropin improved lipid profile and decreased insulin resistance in PCOS. Adropin modulated the components of the gut-brain-ovary axis (short chain fatty acids, free fatty acid receptor 3 and peptide YY) in PCOS. Adropin improved intestinal barrier integrity, suppressed of lipopolysaccharides/Toll-like receptor 4/nuclear factor kappa B signalling pathway and oxidative stress in PCOS.

Protective Effects of Adropin in Experimental Subarachnoid Hemorrhage

PURPOSE

We aimed to investigate early effects of exogenously administered adropin (AD) on neurological function, endothelial nitric oxide synthase (eNOS) expression, nitrite/nitrate levels, oxidative stress, and apoptosis in subarachnoid hemorrhage (SAH).

METHODS

Following intracerebroventricular AD administration (10 µg/5 µl at a rate of 1 µl/min) SAH model was carried out in Sprague-Dawley rats by injection of autologous blood into the prechiasmatic cistern. The effects of AD were assessed 24 h following SAH. The modified Garcia score was employed to evaluate functional insufficiencies. Adropin and caspase-3 proteins were measured by ELISA, while nitrite/nitrate levels, total antioxidant capacity (TAC) and reactive oxygen/nitrogen species (ROS/RNS) were assayed by standard kits. eNOS expression and apoptotic neurons were detected by immunohistochemical analysis.

RESULTS

The SAH group performed notably lower on the modified Garcia score compared to sham and SAH + AD groups. Adropin administration increased brain eNOS expression, nitrite/nitrate and AD levels compared to SHAM and SAH groups. SAH produced enhanced ROS/RNS generation and reduced antioxidant capacity in the brain. Adropin boosted brain TAC and diminished ROS/RNS production in SAH rats and no considerable change amongst SHAM and SAH + AD groups were detected. Apoptotic cells were notably increased in intensity and number after SAH and were reduced by AD administration.

CONCLUSIONS

Adropin increases eNOS expression and reduces neurobehavioral deficits, oxidative stress, and apoptotic cell death in SAH model. Presented results indicate that AD provides protection in early brain injury associated with SAH.

Systemic impacts of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) on heart, muscle, and kidney related diseases

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease (NAFLD), is the most common liver disorder worldwide, with an estimated global prevalence of more than 31%. Metabolic dysfunction-associated steatohepatitis (MASH), formerly known as non-alcoholic steatohepatitis (NASH), is a progressive form of MASLD characterized by hepatic steatosis, inflammation, and fibrosis. This review aims to provide a comprehensive analysis of the extrahepatic manifestations of MASH, focusing on chronic diseases related to the cardiovascular, muscular, and renal systems. A systematic review of published studies and literature was conducted to summarize the findings related to the systemic impacts of MASLD and MASH. The review focused on the association of MASLD and MASH with metabolic comorbidities, cardiovascular mortality, sarcopenia, and chronic kidney disease. Mechanistic insights into the concept of lipotoxic inflammatory "spill over" from the MASH-affected liver were also explored. MASLD and MASH are highly associated (50%-80%) with other metabolic comorbidities such as impaired insulin response, type 2 diabetes, dyslipidemia, hypertriglyceridemia, and hypertension. Furthermore, more than 90% of obese patients with type 2 diabetes have MASH. Data suggest that in middle-aged individuals (especially those aged 45-54), MASLD is an independent risk factor for cardiovascular mortality, sarcopenia, and chronic kidney disease. The concept of lipotoxic inflammatory "spill over" from the MASH-affected liver plays a crucial role in mediating the systemic pathological effects observed. Understanding the multifaceted impact of MASH on the heart, muscle, and kidney is crucial for early detection and risk stratification. This knowledge is also timely for implementing comprehensive disease management strategies addressing multi-organ involvement in MASH pathogenesis.

Hepatic interoception in health and disease

The liver is a large organ with crucial functions in metabolism and immune defense, as well as blood homeostasis and detoxification, and it is clearly in bidirectional communication with the brain and rest of the body via both neural and humoral pathways. A host of neural sensory mechanisms have been proposed, but in contrast to the gut-brain axis, details for both the exact site and molecular signaling steps of their peripheral transduction mechanisms are generally lacking. Similarly, knowledge about function-specific sensory and motor components of both vagal and spinal access pathways to the hepatic parenchyma is missing. Lack of progress largely owes to controversies regarding selectivity of vagal access pathways and extent of hepatocyte innervation. In contrast, there is considerable evidence for glucose sensors in the wall of the hepatic portal vein and their importance for glucose handling by the liver and the brain and the systemic response to hypoglycemia. As liver diseases are on the rise globally, and there are intriguing associations between liver diseases and mental illnesses, it will be important to further dissect and identify both neural and humoral pathways that mediate hepatocyte-specific signals to relevant brain areas. The question of whether and how sensations from the liver contribute to interoceptive self-awareness has not yet been explored.

Attenuation of fibroblast activation and fibrosis by adropin in systemic sclerosis

Fibrotic diseases impose a major socioeconomic challenge on modern societies and have limited treatment options. Adropin, a peptide hormone encoded by the energy homeostasis-associated (ENHO) gene, is implicated in metabolism and vascular homeostasis, but its role in the pathogenesis of fibrosis remains enigmatic. Here, we used machine learning approaches in combination with functional in vitro and in vivo experiments to characterize adropin as a potential regulator involved in fibroblast activation and tissue fibrosis in systemic sclerosis (SSc). We demonstrated consistent down-regulation of adropin/ENHO in skin across multiple cohorts of patients with SSc. The prototypical profibrotic cytokine TGFβ reduced adropin/ENHO expression in a JNK-dependent manner. Restoration of adropin signaling by therapeutic application of bioactive adropin34-76 peptides in turn inhibited TGFβ-induced fibroblast activation and fibrotic tissue remodeling in primary human dermal fibroblasts, three-dimensional full-thickness skin equivalents, mouse models of bleomycin-induced pulmonary fibrosis and sclerodermatous chronic graft-versus-host-disease (sclGvHD), and precision-cut human skin slices. Knockdown of GPR19, an adropin receptor, abrogated the antifibrotic effects of adropin in fibroblasts. RNA-seq demonstrated that the antifibrotic effects of adropin34-76 were functionally linked to deactivation of GLI1-dependent profibrotic transcriptional networks, which was experimentally confirmed in vitro, in vivo, and ex vivo using cultured human dermal fibroblasts, a sclGvHD mouse model, and precision-cut human skin slices. ChIP-seq confirmed adropin34-76-induced changes in TGFβ/GLI1 signaling. Our study characterizes the TGFβ-induced down-regulation of adropin/ENHO expression as a potential pathomechanism of SSc as a prototypical systemic fibrotic disease that unleashes uncontrolled activation of profibrotic GLI1 signaling.

Subarachnoid hemorrhage-associated brain injury and neurobehavioral deficits are reversed with synthetic adropin treatment through sustained Ser1179 phosphorylation of endothelial nitric oxide synthase

Background

Subarachnoid hemorrhage (SAH) is a life-threatening vascular condition without satisfactory treatment options. The secreted peptide adropin is highly expressed in the human brain and has neuroprotective effects in brain injury models, including actions involving the cerebrovasculature. Here, we report an endothelial nitric oxide synthase (eNOS)-dependent effect of synthetic adropin treatment that reverses the deleterious effects of SAH.

Methods

We tested the molecular, cellular, and physiological responses of cultured brain microvascular endothelial cells and two mouse models of SAH to treatment using synthetic adropin peptide or vehicle.

Results

SAH decreases adropin expression in cultured brain microvascular endothelial cells and in murine brain tissue. In two validated mouse SAH models, synthetic adropin reduced cerebral edema, preserved tight junction protein expression, and abolished microthrombosis at 1 day post-SAH. Adropin treatment also prevented delayed cerebral vasospasm, decreased neuronal apoptosis, and reduced sensorimotor deficits at seven days post-SAH. Delaying initial treatment of adropin until 24 h post-SAH preserved the beneficial effect of adropin in preventing vasospasm and sensorimotor deficits. Mechanistically, adropin treatment increased eNOS phosphorylation (Ser1179) at 1 & 7 days post-SAH. Treating eNOS-/- mice with adropin failed to prevent vasospasm or behavioral deficits, indicating a requirement of eNOS signaling.

Conclusions

Adropin is an effective treatment for SAH, reducing cerebrovascular injury in both the acute (1 day) and delayed (7 days) phases. These findings establish the potential of adropin or adropin mimetics to improve outcomes following subarachnoid hemorrhage.

Serum adropin level in wet-type age-related macular degeneration

PURPOSE

Our objective was to compare the serum Adropin levels between patients with wet-type Age-Related Macular Degeneration (AMD) and otherwise healthy individuals.

METHOD

The study included 45 patients with wet-type AMD and 45 individuals without age-related macular degeneration. Patients with co-morbidities such as diabetes, hypertension, autoimmune diseases, and a previous history of visual impairment; were excluded. FBS, Hemoglobin A1C (HbA1C), lipid profile, and serum Adropin level were checked.

RESULTS

The mean serum Adropin level of patients with wet-type AMD was significantly lower than the control group (P-value < 0.001). Also, the mean High-sensitivity C-reactive protein ( hsCRP) level and High Density Lipoprotein (HDL) were significantly higher in wet-type AMD patients (P-value = 0.031 and < 0.001 respectively).

CONCLUSIONS

In our study, wet-type AMD was associated with a lower level of serum Adropin. Because of Adropin involvement in glucose metabolism and age-related changes, it may have a role in the pathogenesis of AMD, but it requires more investigations at the molecular level to elucidate its function.

Dietary Phytochemical Index in Relation to Metabolic Health Status, Serum Adropin, and Brain-Derived Neurotrophic Factor Levels in Adults

Background

Little is known about the relationship between dietary intake of phytochemicals with metabolic health status and underlying mechanisms.

Objectives

Little is known about the relationship between dietary intake of phytochemicals with metabolic health status and underlying mechanisms. We hypothesized that dietary phytochemical index (DPI) improves metabolic health status by ameliorating serum concentrations of brain-derived neurotrophic factor (BDNF) and adropin.

Methods

A cross-sectional study was performed in 527 adults (286 males and 241 females). The dietary intakes of participants were collected by a 168-item food frequency questionnaire, and DPI was estimated as a percentage of energy intake derived from phytochemical-rich foods. Anthropometric variables, blood pressure, glycemic and lipid profiles, and biochemical variables were assessed. The metabolically unhealthy (MU) phenotype was determined based on the definition presented by Wildman et al.

Results

The MU phenotype was identified in 51.4% of male and 32.0% of female participants. Participants in the third tertile of DPI had 59% lower odds of MU than those in the first tertile (OR: 0.41; 95% CI: 0.19, 0.87) after considering potential confounders. Stratified analysis by sex and body mass index indicated that DPI was inversely related to MU phenotype in females (OR: 0.28; 95% CI: 0.08, 0.97) and normal-weight individuals (OR: 0.11; 95% CI: 0.02, 0.62). DPI was also inversely associated with hyperglycemia, hypertriglyceridemia, and chronic inflammation. Nonsignificant reduced odds of low BDNF (OR: 0.87; 95% CI: 0.42, 1.84) and adropin (OR: 0.75; 95% CI: 0.31, 1.79) were observed in individuals in the top tertile of DPI compared with those in the bottom tertile.

Conclusions

This study showed that individuals with higher dietary intake of phytochemicals had lower odds of MU, particularly females and normal-weight individuals. No significant relationship was observed between serum BDNF and adropin with phytochemical intake.

Low circulating adropin concentrations predict increased risk of cognitive decline in community-dwelling older adults

The secreted peptide adropin is highly expressed in human brain tissues and correlates with RNA and proteomic risk indicators for dementia. Here we report that plasma adropin concentrations predict risk for cognitive decline in the Multidomain Alzheimer Preventive Trial (ClinicalTrials.gov Identifier, NCT00672685; mean age 75.8y, SD = 4.5 years, 60.2% female, n = 452). Cognitive ability was evaluated using a composite cognitive score (CCS) that assessed four domains: memory, language, executive function, and orientation. Relationships between plasma adropin concentrations and changes in CCS (∆CCS) were examined using Cox Proportional Hazards Regression, or by grouping into tertiles ranked low to high by adropin values and controlling for age, time between baseline and final visits, baseline CCS, and other risk factors (e.g., education, medication, APOE4 status). Risk of cognitive decline (defined as a ∆CCS of - 0.3 or more) decreased with increasing plasma adropin concentrations (hazard ratio = 0.873, 95% CI 0.780-0.977, P = 0.018). Between adropin tertiles, ∆CCS was significantly different (P = 0.01; estimated marginal mean ± SE for the 1st to 3rd tertile, - 0.317 ± 0.064; - 0.275 ± 0.063; - 0.042 ± 0.071; n = 133,146, and 130, respectively; P < 0.05 for 1st vs. 2nd and 3rd adropin tertiles). Normalized plasma Aß42/40 ratio and plasma neurofilament light chain, indicators of neurodegeneration, were significantly different between adropin tertile. These differences were consistent with reduced risk of cognitive decline with higher plasma adropin levels. Overall, these results suggest cognitive decline is reduced in community-dwelling older adults with higher circulating adropin levels. Further studies are needed to determine the underlying causes of the relationship and whether increasing adropin levels can delay cognitive decline.

Adropin, a novel hepatokine: localization and expression during postnatal development and its impact on testicular functions of pre-pubertal mice

Adropin, a multifaceted peptide, was identified as a new metabolic hormone responsible for regulating gluco-lipid homeostasis. However, its role in the testicular function is not yet understood. We aimed to investigate the localization and expression of adropin and GPR19 during different phases of postnatal development. Immunohistochemical study revealed the intense reactivity of adropin in the Leydig cells during all phases of postnatal development, while GPR19 showed intense immunoreactivity in the pachytene spermatocytes and mild immunoreactivity in Leydig cells as well as primary and secondary spermatocytes. Western blot study revealed maximum expression of GPR19 in pre-pubertal mouse testis that clearly indicates maximum responsiveness of adropin during that period. So, we hypothesized that adropin may act as an autocrine/paracrine factor that regulates pubertal changes in mouse testis. To examine the effect of adropin on pubertal onset, we gave bilateral intra-testicular doses (0.5 and 1.5 µg/testis) to pre-pubertal mice. Adropin treatment promoted testicular testosterone synthesis by increasing the expression of StAR, 3β-HSD, and 17β-HSD. Adropin also promoted germ cell survival and proliferation by upregulating the expression of PCNA and downregulating the Bax/Bcl2 ratio and Caspase 3 expression resulting in fewer TUNEL-positive cells in adropin-treated groups. FACS analysis demonstrated that adropin treatment not only increases 1C to 4C ratio but also significantly increases the 1C (spermatid) and 1C to 2C ratio which demarcates accelerated germ cell differentiation and turnover of testicular cells. In conclusion, adropin promotes steroidogenesis, germ cell survival, as well as the proliferation in the pre-pubertal mouse testis that may hasten the pubertal transition in an autocrine/paracrine manner.

Bridging neurotrophic factors and bioactive peptides to Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder. As the demographic shifting towards an aging population, AD has emerged as a prominent public health concern. The pathogenesis of AD is complex, and there are no effective treatment methods for AD until now. In recent years, neurotrophic factors and bioactive peptides including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), irisin, melatonin, have been discovered to exert neuroprotective functions for AD. Bioactive peptides can be divided into two categories based on their sources: endogenous and exogenous. This review briefly elaborates on the pathogenesis of AD and analyzes the regulatory effects of endogenous and exogenous peptides on the pathogenesis of AD, thereby providing new therapeutic targets for AD and a theoretical basis for the application of bioactive peptides as adjunctive therapies for AD.

Development and validation of a new diagnostic prediction model of ENHO and NOX4 for early diagnosis of systemic sclerosis

Objective

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by fibrosis. The challenge of early diagnosis, along with the lack of effective treatments for fibrosis, contribute to poor therapeutic outcomes and high mortality of SSc. Therefore, there is an urgent need to identify suitable biomarkers for early diagnosis of SSc.

Methods

Three skin gene expression datasets of SSc patients and healthy controls were downloaded from Gene Expression Omnibus (GEO) database (GSE130955, GSE58095, and GSE181549). GSE130955 (48 early diffuse cutaneous SSc and 33 controls) were utilized to screen differentially expressed genes (DEGs) between SSc and normal skin samples. Least absolute shrinkage and selection operator (LASSO) regression and support vector machine recursive feature elimination (SVM-RFE) were performed to identify diagnostic genes and construct a diagnostic prediction model. The results were further validated in GSE58095 (61 SSc and 36 controls) and GSE181549 (113 SSc and 44 controls) datasets. Receiver operating characteristic (ROC) curves were applied for assessing the level of diagnostic ability. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to verify the diagnostic genes in skin tissues of out cohort (10 SSc and 5 controls). Immune infiltration analysis were performed using CIBERSORT algorithm.

Results

A total of 200 DEGs were identified between SSc and normal skin samples. Functional enrichment analysis revealed that these DEGs may be involved in the pathogenesis of SSc, such as extracellular matrix remodeling, cell-cell interactions, and metabolism. Subsequently, two critical genes (ENHO and NOX4) were identified by LASSO and SVM-RFE. ENHO was found down-regulated while NOX4 was up-regulated in skin of SSc patients and their expression levels were validated by above three datasets and our cohort. Notably, these differential expressions were more pronounced in patients with diffuse cutaneous SSc than in those with limited cutaneous SSc. Next, we developed a novel diagnostic model for SSc using ENHO and NOX4, which demonstrated strong predictive power in above three cohorts and in our own cohort. Furthermore, immune infiltration analysis revealed dysregulated levels of various immune cell subtypes within early SSc skin specimens, and a negative correlation was observed between the levels of ENHO and Macrophages M1 and M2, while a positive correlation was observed between the levels of NOX4 and Macrophages M1 and M2.

Conclusion

This study identified ENHO and NOX4 as novel biomarkers that can be serve as a diagnostic prediction model for early detection of SSc and play a potential role in the pathogenesis of the disease.

Adropin may promote insulin stimulated steroidogenesis and spermatogenesis in adult mice testes

Adropin is a versatile peptide which was discovered as a novel metabolic hormone that is involved in the regulation of lipid and glucose homeostasis. However, its possible role in the testicular function is not yet understood. The aim of our study was to explore the distribution pattern of adropin and GPR19 in various cell types and its possible role in testicular functions of adult mice. Immunohistochemical study revealed the intense immunoreactivity of adropin in the Leydig cells, while GPR19 showed intense immunoreactivity in the pachytene spermatocytes and mild immunoreactivity in Leydig cells and primary as well as secondary spermatocytes in mouse testis. Enho mRNA was also found to be expressed in the mouse testis. These findings suggested that adropin-GPR19 signaling may act in autocrine/paracrine manner to modulate testicular functions. Furthermore, to find out the direct role of adropin in the testicular function, in vitro study was performed in which testicular slices were cultured with adropin alone (10 and 100 ng/mL) and in combination with insulin (5 μg/mL). Adropin alone inhibited testicular testosterone synthesis by inhibiting the expression of P450-SCC, 3β-HSD, and 17β-HSD while along with insulin stimulated the testicular testosterone synthesis by increasing the expression of GPR19, IR, StAR, P450-SCC, 3β-HSD, and 17β-HSD. Adropin alone or in combination with insulin promoted germ cell survival and proliferation by upregulating the expression of PCNA, Bcl2, and pERK1/2. Thus, it can be concluded that adropin-GPR19 signaling promotes insulin stimulated steroidogenesis and germ cell survival as well as proliferation in the mice testes in an autocrine/paracrine manner.

Protective effect of ellagic acid against high-glucose-induced injury in human umbilical venous endothelial cells

Objective

There is escalating evidence suggesting the beneficial effects of ellagic acid (EA) on the cardiovascular system. The aim of the present study was to investigate the protective effect of EA in human umbilical vein endothelial cells (HUVECs) against high glucose (HG)- induced endothelial dysfunction and to study the potential roles of adropin and nitric oxide (NO) in this regard.

Materials and Methods

The experimental groups consisted of normal and HG (30 mM, 48 hr)-treated HUVECs incubated without or with 5 or 10 μM of EA (6 groups of at least 6 replicates, each). The cell count and viability were studied. Moreover, the markers of the redox state, including malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and catalase enzymes, and ferric reducing anti-oxidant power (FRAP), were assayed. The levels of adropin and eNOS gene expression were also studied using RT-qPCR.

Results

A high concentration of glucose reduced cell count and caused lipid peroxidation, reduced anti-oxidant capacity of the cells, decreased NO levels, and downregulated the expression of NOS3 (encoding eNOS) and ENHO (encoding adropin) genes. Ellagic acid reversed all these effects.

Conclusion

These results suggest a significant protective effect for EA against HG-induced injury in HUVECs. The improved redox state and upregulation of NOS3 and ENHO genes seem to play critical roles in this regard.

Diet in relation to Metabolic, sleep and psychological health Status (DiMetS): protocol for a cross-sectional study

INTRODUCTION

Metabolic disturbances are of major health concerns in the world. In addition to their high prevalence, these disorders have substantial roles in developing other physical and mental diseases. Diet could have a considerable influence on managing the progression of these conditions and their consequent health-related effects. The aim of the 'Diet in relation to Metabolic, sleep and psychological health Status' Project is to explore the association of nutrition with metabolic, sleep and mental health, considering potential mediators including brain-derived neurotrophic factor (BDNF) and adropin.

METHODS AND ANALYSIS

This cross-sectional study will be conducted on adults (20-65 years) working in schools of Isfahan, Iran. A multistage cluster random sampling method will be used to select participants. Anthropometric, body composition and biochemical values including fasting blood glucose, lipid profile, 25-hydroxy vitamin D, insulin, BDNF, adropin, malondialdehyde, superoxide dismutase, glutathione peroxidase, uric acid, creatinine and C reactive protein will be measured for each participant. National Cholesterol Education Program and Adult Treatment Panel III will be considered to define metabolic syndrome. Diet will be assessed through a validated Food Frequency Questionnaire. Furthermore, sleep status, mental health, quality of life, physical activity and demographic status of individuals will be assessed by validated questionnaires. The collected data will be analysed using appropriate statistical methods.

ETHICS AND DISSEMINATION

The study protocol was approved by the local Ethics Committee of Isfahan University of Medical Sciences. All participants will provide written informed consent. Dissemination will be through conference presentations and publications in peer-reviewed journals.