Serum Chemerin Levels in relation to Osteoporosis and Bone Mineral Density: A Case-Control Study

Loss of chemerin prevents ovariectomy-induced osteoporosis in mice through intraosseous vascular remodeling

Chemerin, an adipocyte-secreted adipokine, can regulate bone resorption and bone formation and is a promising therapy for postmenopausal osteoporosis. However, the effect of endogenous chemerin on intraosseous vascular remodeling in postmenopausal osteoporosis remains unclear. In this study, we investigated the effect of chemerin on osteogenesis formation and intraosseous vascular remodeling in ovariectomized Rarres2 knockout (Rarres2-/-) mice. The results showed that the bone mineral density (BMD) and volume score, trabecular thickness, cortical thickness, bone formation marker BALP and osteocalcin, and angiogenesis markers CD31 and EMCN significantly increased in ovariectomized Rarres2-/- mice. Furthermore, the expression of biomarkers to osteoblasts (β-catenin and Runx2) and angiogenesis markers (VEGF-A, Noggin, and Ang-1) significantly increased in the bone tissue of ovariectomized Rarres2-/- mice, as well as in bone marrow stromal cells and primary intraosseous vascular endothelial cells of Rarres2-/- mice. Conversely, treatment with chemerin significantly inhibited expression of biomarkers for osteoblasts and angiogenesis markers in bone marrow stromal cells and primary intraosseous vascular endothelial cells of Rarres2-/- mice. More importantly, the supernatants of the primary intraosseous vascular endothelial cells of the Rarres2-/- mice could promote the osteogenic differentiation effect of BMSCs, which could be blocked by treating with the chemerin recombinant protein. These data indicate that endogenous chemerin has an inhibitory effect on intraosseous vascular formation as well as osteoblast differentiation and proliferation in ovariectomy-induced osteoporosis mice. Chemerin effectively promoted postmenopausal osteoporosis development, which is associated with the involvement of chemerin in the reduction of microcirculation within the skeleton.

The role of adipokines in osteoporosis management: a mini review

The prevalence of osteoporosis has been on the rise globally. With ageing populations, research has sought therapeutic solutions in novel areas. One such area is that of the adipokines. Current literature points to an important role for these chemical mediators in relation to bone metabolism. Well-established adipokines have been broadly reported upon. These include adiponectin and leptin. However, other novel adipokines such as visfatin, nesfatin-1, meteorin-like protein (Metrnl), apelin and lipocalin-2 are starting to be addressed pre-clinically and clinically. Adipokines hold pro-inflammatory and anti-inflammatory properties that influence the pathophysiology of various bone diseases. Omentin-1 and vaspin, two novel adipokines, share cardioprotective effects and play essential roles in bone metabolism. Studies have reported bone-protective effects of omentin-1, whilst others report negative associations between omentin-1 and bone mineral density. Lipocalin-2 is linked to poor bone microarchitecture in mice and is even suggested to mediate osteoporosis development from prolonged disuse. Nesfatin-1, an anorexigenic adipokine, has been known to preserve bone density. Animal studies have demonstrated that nesfatin-1 treatment limits bone loss and increases bone strength, suggesting exogenous use as a potential treatment for osteopenic disorders. Pre-clinical studies have shown adipokine apelin to have a role in bone metabolism, mediated by the enhancement of osteoblast genesis and the inhibition of programmed cell death. Although many investigations have reported conflicting findings, sufficient literature supports the notion that adipokines have a significant influence on the metabolism of bone. This review aims at highlighting the role of novel adipokines in osteoporosis while also discussing their potential for treating osteoporosis.

Secretome-based acellular therapy of bone marrow-derived mesenchymal stem cells in degenerative and immunological disorders: A narrative review

The bone marrow (BM) plays a pivotal role in homeostasis by supporting hematopoiesis and immune cells' activation, maturation, interaction, and deployment. "BMSC-derived secretome" refers to the complete repertoire of secreted molecules, including nucleic acids, chemokines, growth factors, cytokines, and lipids from BM-derived mesenchymal stem cells (BMSCs). BMSC-derived secretomes are the current molecular platform for acellular therapy. Secretomes are highly manipulable and can be synthesised in vast quantities using commercially accessible cell lines in the laboratory. Secretomes are less likely to elicit an immunological response because they contain fewer surface proteins. Moreover, the delivery of BMSC-derived secretomes has been shown in numerous studies to be an effective, cell-free therapy method for alleviating the symptoms of inflammatory and degenerative diseases. As a result, secretome delivery from BMSCs has the same therapeutic effects as BMSCs transplantation but may have fewer adverse effects. Additionally, BMSCs' secretome has therapeutic promise for organoids and parabiosis studies. This review focuses on recent advances in secretome-based cell-free therapy, including its manipulation, isolation, characterisation, and delivery systems. The diverse bioactive molecules of secretomes that successfully treat inflammatory and degenerative diseases of the musculoskeletal, cardiovascular, nervous, respiratory, reproductive, gastrointestinal, and anti-ageing systems were also examined in this review. However, secretome-based therapy has some unfavourable side effects that may restrict its uses. Some of the adverse effects of this modal therapy were briefly mentioned in this review.

Novel Adipokines and Their Role in Bone Metabolism: A Narrative Review

The growing burden of obesity and osteoporosis is a major public health concern. Emerging evidence of the role of adipokines on bone metabolism has led to the discovery of novel adipokines over the last decade. Obesity is recognized as a state of adipose tissue inflammation that adversely affects bone health. Adipokines secreted from white adipose tissue (WAT) and bone marrow adipose tissue (BMAT) exerts endocrine and paracrine effects on the survival and function of osteoblasts and osteoclasts. An increase in marrow fat is implicated in osteoporosis and, hence, it is crucial to understand the complex interplay between adipocytes and bone. The objective of this review is to summarize recent advances in our understanding of the role of different adipokines on bone metabolism.

METHODS

This is a comprehensive review of the literature available in PubMED and Cochrane databases, with an emphasis on the last five years using the keywords.

RESULTS

Leptin has shown some positive effects on bone metabolism; in contrast, both adiponectin and chemerin have consistently shown a negative association with BMD. No significant association was found between resistin and BMD. Novel adipokines such as visfatin, LCN-2, Nesfatin-1, RBP-4, apelin, and vaspin have shown bone-protective and osteoanabolic properties that could be translated into therapeutic targets.

CONCLUSION

New evidence suggests the potential role of novel adipokines as biomarkers to predict osteoporosis risk, and as therapeutic targets for the treatment of osteoporosis.

Association of serum levels of Visfatin, Intelectin-1, RARRES2 and their genetic variants with bone mineral density in postmenopausal females

BACKGROUND

Adipokines are engaged in bone physiology and regulate bone mineral density (BMD) by playing protective or cynical role in bone metabolism. The study is designed to measure and compare BMD, adipokines (retinoic acid receptor responder protein-2 RARRES2, visfatin and Intelectin-1) and their genetic variants in postmenopausal osteoporotic, osteopenic and non-osteoporotic females.

METHODS

This comparative study included postmenopausal non-osteoporotic (n=72), osteopenic (n=72) and osteoporotic (n=100) females with two years of amenorrhea and age between 50 to 70 years. Gold standard DXA was used to measure BMD. Hardy-Weinberg equilibrium was established. Kruskal-Wallis test for comparisons, logistic and multivariate regression analysis were used to rule out the predictors of BMD.

RESULTS

On comparing the three groups, significant differences were observed in serum RARRES2 (p <0.001) and serum visfatin (p=0.050). The significant positive predictor of BMD at lumbar spine and total hip was serum visfatin. BMD at right and left femoral neck was predicted negatively by serum chemerin while BMD at left femoral neck was also predicted positively by serum calcium levels. There was significant difference in BMD at right femoral neck (p = 0.033) between rs7806429 genotypes. The odds of having low BMD increases with increasing serum levels of chemerin and decreasing serum levels of visfatin and calcium.

CONCLUSION

The adipokines RARRES2 and visfatin are associated with BMD. RARRES2 is an independent negative and visfatin is positive predictor of BMD in postmenopausal females. BMD at right femoral neck was significantly low in RARRES2 rs7806429 TC heterozygotes.

Association of High Serum Chemerin with Bone Mineral Density Loss and Osteoporotic Fracture in Elderly Chinese Women

Background

Chemerin has been suggested to be a risk factor for osteoporosis; however, its relationship with osteoporotic fracture is poorly understood. Herein, we intend to explore the association between serum chemerin and osteoporotic fracture.

Methods

A total of 111 elderly women patients diagnosed with osteoporotic fracture were selected as the observation group, and 40 healthy subjects were enrolled as controls. Dual-energy X-ray absorptiometry, enzyme-linked immunosorbent assay, electrochemiluminescence immunoassay, and biochemical analysis were separately performed to determine body bone mineral density (BMD), chemerin levels, bone turnover markers, and other parameters. Pearson's correlation analysis was conducted to examine a relationship between chemerin and laboratory parameters. Moreover, the levels of chemokine-like receptor 1 (CMKLR), C-C motif chemokine receptor-like 2 (CCRL2), collagen type I alpha (COLA1), and runt-related transcription factor-2 (RUNX2) were confirmed by quantitative polymerase chain reaction, and the effect of chemerin on osteogenic differentiation of hFOB1.19 cells was indicated by tartrate-resistant acid phosphatase and alkaline phosphatase double staining.

Results

A higher level of chemerin was generally detected in patients with osteoporotic fracture compared with those without (P<0.05). Compared with controls, lower BMD levels and higher β-CTx and P1NP levels were detected in patients with osteoporotic fracture (all P<0.05). Interestingly, chemerin level was negatively correlated to BMD, but positively related to P1NP and β-CTx. Risk of osteoporotic fracture was 2.75-fold higher in subjects with each standard deviation increment of chemerin. Compared with controls, there were no significant differences in CMKLR1 and CCRL2 mRNA after incubation with osteogenic differentiation medium (all P>0.05), whereas there was a remarkable decrease of COLA1 and RUNX2 after incubation with chemerin for nine days (all P<0.05). Furthermore, prolonged incubation with chemerin enhanced osteoclast differentiation and maturation, consequently contributing to an increased risk of fracture.

Conclusion

Chemerin is a strong and independent risk factor for osteoporosis-related fracture among elderly Chinese women.

Loss of chemerin triggers bone remodeling in vivo and in vitro

OBJECTIVE

It was reported that chemerin as an adipocyte-secreted protein could regulate bone resorption and bone formation. However, the specific molecular and gene mechanism of the chemerin role is unclear. The aim of this study is to evaluate the role of chemerin in bone metabolism.

METHODS

In the present study, we investigated the effects of chemerin on bone remodeling in rarres2 knockout (Rarres2-/-) mice and examined the role of chemerin as a determinant of osteoblast and osteoclast differentiation in Mc3t3-E1 and Raw264.7 cell lines.

RESULTS

The results showed that the bone mineral density and volume score, trabecular thickness, weight and bone formation marker BALP increased, but Tb.Sp and bone resorption marker TRACP-5b decreased in Rarres2-/- mice. Furthermore, the mRNA and protein expression of biomarkers of osteoblasts (β-catenin, RANKL and OPG) significantly increased, but those of osteoclasts (CTSK and RANK) decreased in Rarres2-/- mice. In vitro, chemerin markedly suppressed β-catenin and OPG, but increased RANKL, CTSK and RANK expression. Moreover, knockdown of chemerin using RNA interference enhanced osteoblastogenesis genes and inhibited osteoclastogenesis genes in Mc3t3-E1 and Raw264.7 cells.

CONCLUSIONS

Taken together, these data suggest an inhibitive effect of chemerin on osteoblast differentiation and proliferation through inhibition of Wnt/β-catenin signaling, as well as a stimulative effect of chemerin on osteoclast differentiation and proliferation via activation of RANK signaling. The maintenance of a low chemerin level may be a strategy for the prevention and treatment of osteoporosis.

Association of serum chemerin with calcium, alkaline phosphatase and bone mineral density in postmenopausal females

OBJECTIVES

To investigate the association of serum chemerin with calcium, alkaline phosphatase and bone mineral density in postmenopausal non-osteoporotic and osteoporotic females.

METHODS

This cross-section analysis was carried out at the orthopedic department of Madina Teaching Hospital, Faisalabad, Pakistan, in the year 2017-2019. Postmenopausal females were divided into two groups according to their bone mineral density (BMD). All osteoporotic females had a T-score of -2.5 or less. Data were analyzed on SPSS-24.

RESULTS

A total of 140 women were included in our study (80 osteoporotic and 60 non-osteoporotic). Non significant difference in age and BMI was observed between osteoporotic and non-osteoporotic subjects (p=0.152) and (p=0.291) respectively. There was a significant difference found in total BMD, serum chemerin levels between osteoporotic and non-osteoporotic subjects p<0.001 in both parameters. No significant correlation of serum chemerin was found with serum calcium, serum alkaline phosphatase and BMD in postmenopausal osteoporotic females (p=0.907), (p=0.318) (p=0.664) respectively. A significant negative correlation was found between serum alkaline phosphatase levels and total BMD in postmenopausal osteoporotic females (p=- 0.039). Linear regression analysis of serum alkaline phosphatase levels with total BMD showed no association between BMD and serum alkaline phosphatase levels (p=0.869).

CONCLUSION

There is no association of serum chemerin with calcium, ALP and bone mineral density in non-osteoporotic and osteoporotic postmenopausal females.

The Innovative and Sustainable Use of Dental Panoramic Radiographs for the Detection of Osteoporosis

This bibliometric study evaluated the scientific impact of papers dealing with osteoporosis detected by dental panoramic radiographs by performing citation analysis and cited reference analysis. Retrospective data was extracted from the Web of Science Core Collection database and imported into VOSviewer, CRExplorer, and CitNetExplorer for analyzing semantic contents, cited references, and temporal citation network. The 280 relevant papers identified were cited 4874 times, having an h-index of 38 and 17.4 citations per paper. The top five major contributing countries were Japan (n = 54, 19.3%), USA (n = 43, 15.4%), Brazil (n = 38, 13.6%), Turkey (n = 38, 13.6%), and the UK (n = 32, 11.4%). Citation per paper correlated with publication count among the authors and institutions. Mandibular cortical width was the most frequently used and most cited measurement index. References published during the 1970s and 1980s have built the foundation for the development of research that investigates the potential associations between osteoporosis and radiographic measurements on panoramic radiographs. Osteoporosis detection by dental panoramic radiographs is a perennially investigated research topic with global contributions. Panoramic radiographs are considered early detection and screening tools for osteoporosis by worldwide research.

The cross-sectional association between chemerin and bone health in peri/pre and postmenopausal women: results from the EPIC-Potsdam study

Objective:

Recent in vitro data suggested that the novel adipokine chemerin may influence bone health. However, only limited evidence of the relationship between chemerin and bone health in humans is available. Therefore, this study aimed to investigate the association between chemerin and broadband ultrasound attenuation (BUA) in peri/premenopausal and postmenopausal women.

Methods:

Data from the German population-based European Prospective Investigation into Cancer and Nutrition-Potsdam cohort comprising 404 peri/premenopausal and 279 postmenopausal women were analyzed. Multivariable-adjusted analysis of covariance including age, body mass index, waist circumference, smoking status, education, physical activity, alcohol consumption, and hormone use was used to investigate potential relationships between the adipokine and BUA levels in peri/premenopausal and postmenopausal women, respectively.

Results:

The concentrations of chemerin were lower in peri/premenopausal women (median 118.0 ng/mL, interquartile range [IQR] 99.2-135.0), compared with postmenopausal women (median 140.0 ng/mL, IQR 121.0-167.0). In peri/premenopausal women chemerin was inversely associated with BUA levels; after multivariable adjustment, a 10% increase in the chemerin concentration was significantly associated with 0.83 dB/MHz lower BUA levels (P = 0.0006). In postmenopausal women chemerin was not related to BUA levels (P = 0.8).

Conclusion:

The present study provides evidence for an inverse association between chemerin and BUA in peri/premenopausal women. Therefore, the study suggests that high chemerin concentrations may minimize peak bone mass and thereby may promote age-related bone loss. Further studies are needed to investigate the role of chemerin in bone homeostasis in peri/premenopausal and postmenopausal women.

Adipokines may mediate the relationship between resting metabolic rates and bone mineral densities in obese women

The researchers sought to test the possible link between resting metabolic rate and bone mineral density through four adipokines. Participants with lower resting metabolic rate (RMR) per kilogram demonstrated higher total bone mineral density (BMD), total T-score, and total Z-score. Omentin-1 had a mediatory effect on the relationship between RMR/kg of body weight and bone parameters.

INTRODUCTION

The previous results of studies regarding the links between obesity and bone health are controversial. For this reason, the researchers sought to test the possible link between RMR and BMD through the following four adipokines: vaspin, retinol binding protein 4, angiopoietin-like 6 (ANGPL6), and omentin-1.

METHODS

We enrolled 312 obese Iranian women (30 ≤ body mass index <40) in this cross-sectional study. In order to examine the association of serum adipokine levels with RMR and BMD, the participants were grouped based on RMR per body weight. Body composition, dietary intake, bone mineral density, and resting metabolic rate were assessed in all participants. Serum adipokine levels were quantified by the enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

Low levels of RMR/kg were strongly associated with higher weight, body mass index, fat mass, and visceral fat levels. In fact, participants with an RMR/kg of body weight <20 kcal/24 h/kg were more obese (p < 0.05). Another noteworthy finding was that participants with lower RMR/kg demonstrated higher total BMD, total T-score, and total Z-score. Our results showed that omentin-1 had a mediatory effect on the relationship between RMR per kilogram of body weight and bone parameters (p < 0.05). Nevertheless, other adipokines such as vaspin, retinol-binding protein 4 (RBP4), and ANGPL6 did not affect the relationship between RMR and BMD (p > 0.05).

CONCLUSIONS

The inhibitory effect of omentin-1 on TNF-alpha seems to be able to reduce the amount of circulating leptin as adipokine, affecting energy expenditure and improving bone loss induced by estrogen deficiency and controlled effect of RMR on BMD.

Postmenopausal Osteoporosis Is Associated with Serum Chemerin and Irisin but Not with Apolipoprotein M Levels

Objectives

The objective of this study was to describe the levels of chemerin, irisin and apolipoprotein M (apoM) in women with postmenopausal osteoporosis.

Methods

The study included 88 women with postmenopausal osteoporosis. Based on World Health Organization criteria, women with a T-score of ≤ –2.5 were defined as osteoporotic. In this case-control study, postmenopausal women with T-score > –1 were selected as controls (n = 88) and case-matched in a 1:1 ratio based on age (within 2 years) and body mass index (BMI) (within 1.0 kg/m²). ApoM, irisin and chemerin levels were determined by a commercially available enzyme-linked immunosorbent assay (ELISA) kit.

Results

There were no significant differences in age, BMI, parity, cholesterol and apoM levels between the two groups. C-reactive protein levels were significantly increased in women with osteoporosis. Serum chemerin levels (240.1 ± 46.1 vs. 261.5 ± 50.8 ng/mL) were significantly lower in the women with osteoporosis, as compared to the controls (P = 0.004). Serum irisin levels were also decreased in women with osteoporosis (0.7 ± 0.2 vs. 0.8 ± 0.2 ng/mL; P = 0.007).

Conclusion

In the present study, osteoporosis was associated with decreased levels of circulating chemerin and irisin. These findings suggested that adipokines might play a role in the pathogenesis of osteoporosis.

Association of chemerin levels and bone mineral density in Chinese obese postmenopausal women

Increasing evidence suggests the association between obesity and bone metabolism. However, whether excessive fat accumulation has a beneficial or adverse effect on bone health remains controversial. Chemerin is a novel adipocyte-derived hormone and a chemoattractant cytokine that regulates adipogenesis. This study was performed to investigate the associations of serum chemerin with bone mineral density (BMD) and serum pro-inflammatory cytokine levels in 543 Chinese obese postmenopausal women. BMD of the femoral neck and lumbar spine, lean mass, and fat mass were measured using dual energy X-ray absorptiometry. Anthropometric assessment and laboratory measurements were performed. The age, time after menopause, and fat mass were negatively correlated with femoral and lumbar BMD, whereas lean mass was positively correlated with aforementioned variables. Furthermore, BMD at the lumbar spine was inversely associated with serum chemerin and TNF-α levels (r = -0.155, P = 0.001; r = -0.147, P = 0.001). Multiple linear regression analyses showed that serum chemerin levels were negatively correlated with BMD at the lumbar site after controlling for the age, lean, and fat mass (β = -0.125, P = 0.001). Chronic low-grade inflammation state in obese population has an inverse effect on bone mass. Chemerin as an adipocytokine and chemoattractant negatively affects the bone mass of Chinese obese postmenopausal women. Further studies are needed to confirm the potential role of chemerin in the crosstalk between bone and fat accumulation in obese population.