Association of Circulating Omentin-1 with Osteoporosis in a Chinese Type 2 Diabetic Population

Therapeutic potential of omentin-1 in preeclampsia: enhancing fetal outcomes, vascular function, and reducing inflammation

This study evaluated the therapeutic potential of omentin-1 in preeclampsia (PE). A PE-like mouse model received recombinant human omentin-1 protein (rh-omentin) from gestation day (gd) 13.5 to 16.5. On gd 17.5, fetuses and placentas were weighed, and soluble fms-like tyrosine kinase-1 (sFlt-1) levels were measured. Maternal aortic rings were used for ex vivo vascular reactivity assays. Inflammatory factors and Krüppel-like factor 2 (KLF2) expression in placental and aortic tissues were assessed using qPCR. Human umbilical vein endothelial cells (HUVECs) were exposed to plasma from PE patients or healthy pregnant individuals to evaluate omentin-1 and KLF2 expression by qPCR, with additional evaluation of KLF2 after rh-omentin treatment. Rh-omentin treatment reduced blood pressure in the PE-like model, accompanying by increased fetal and placental weights and higher fetal/placental weight ratios compared to untreated PE mice. Additionally, rh-omentin enhanced endothelial function in maternal aortic rings, as well as reduced placental necrosis and promoted CD31-positive vasculature in the labyrinth zone. Moreover, rh-omentin decreased pro-inflammatory factors in aortic and placental tissues of PE mice. KLF2 expression was restored in both aortic and placental tissues of PE mice and in HUVECs exposed to PE plasma following rh-omentin treatment. Rh-omentin improved fetal and placental outcomes in PE-like mice, enhancing vascular function and reducing inflammation in aortic and placental tissues. It also restored KLF2 expression in PE tissues and HUVECs exposed to PE plasma, suggesting therapeutic potential for addressing endothelial dysfunction in PE.

Serum A20 level is associated with bone mineral density in male patients with type 2 diabetes mellitus

Background

A20, also known as TNF-α-induced protein 3 (TNFAIP3), is a crucial negative regulator of inflammation and immune responses. Emerging evidence suggests that A20 is involved in the regulation of glucose metabolism and plays a significant role in bone metabolic diseases by inhibiting nuclear factor (NF)-κB activation. However, the potential relationship between serum A20 level and bone mineral density (BMD) in patients with type 2 diabetes mellitus (T2DM) has not been explored. This study aims to investigate the association between serum A20 level with BMD and bone turnover markers (BTMs) in patients with T2DM.

Method

A total of 189 patients with T2DM and 183 non-diabetic individuals were included in the study based on the inclusion and exclusion criteria. Participants were categorized into normal BMD and low BMD groups. Baseline clinical histories were collected through face-to-face questionnaires. Participants underwent measurements of blood biochemistry and anthropometric, hand grip strength records and short physical performance battery (SPPB) assessment. Serum A20 level was quantified by enzyme-linked immunosorbent assay kit. Areal BMD was measured using dual-energy x-ray absorptiometry (DXA). A T-score of less than -1.0 at the lumbar spine 1-4, femoral neck and/or total hip was classified as low BMD.

Results

Serum A20 level was lower in patients with T2DM compared to controls [41.30 (29.91, 61.87) vs 76.01 (54.90, 109.64) pg/mL, P<0.001]. Bivariate correlation analysis revealed that A20 level was not associated with SPPB but negatively correlated with waist-to-hip ratio (WHR). Pearson correlation analysis showed A20 level was positively correlated with lumbar spine 1-4 BMD in male diabetic patients (r=0.253, P=0.032). Multivariate regression analysis showed a positive association between serum A20 level and lumbar spine 1-4 BMD (Beta=0.047; 95% CI: 0.007-0.086; P=0.024) after multivariate adjustment. Logistic regression analysis showed that lower serum A20 level predicted low BMD in male patients with T2DM (OR: 0.22; 95% CI: 0.09-0.59; P=0.002).

Conclusions

Type 2 diabetic patients exhibited lower serum A20 level compared to non-diabetic individuals. In male patients with T2DM, serum A20 level showed a significant positive correlation with lumbar spine 1-4 BMD and could serve as an independent negative predictor for low BMD.

Relationship between serum level of miR-338-3p and miR-105-3p and bone metabolic markers in patients with diabetes nephropathy

OBJECTIVES

Diabetic nephropathy (DN) is one of the most common and serious complications of diabetes. The purpose of this study was to explore the relationship between serum microRNA-338-3p (miR-338-3p) and miR-105-3p and bone metabolic markers in patients with DN at different stages.

METHODS

A total of 153 patients diagnosed and treated in the Department of Nephrology from July 2020 to October 2021 were selected as the study objects. According to the staging criteria of diabetic nephropathy and 24-h urinary albumin quantitative level, the patients were divided into control group (35 cases), microalbuminuria group (37 cases), clinical stage albuminuria group (27 cases) and renal failure group (54 cases). Gene expressions were measured by real-time fluorescence quantitative PCR. The correlation was analyzed by Spearman. Serum miR-338-3p and miR-150-5p in the prediction of renal failure in DN was analyzed by ROC curve.

RESULTS

The levels of urinary albumin and serum creatinine were markedly increased with the increase of DN stage (p < 0.05). Compared with the microalbuminuria group, the expression levels of serum miR-383-3p, serum miR-105-3p, 25(OH)-D, BGP and PINP were obviously decreased, but the expression of parathyroid hormone (PTH) and type I collagen (β-CTX) was largely increased in clinical proteinuria group (p < 0.05). Compared with the clinical proteinuria group, the expression levels of serum miR-383-3p, serum miR-105-3p, 25(OH)-D, BGP and PINP were largely decreased, but the expression of PTH and β-CTX was obviously increased in the renal failure group (p < 0.05). Spearman correlation results showed that serum expressions of miR-383-3p and miR-105-3p were negatively correlated with PTH and β-CTX, and positively correlated with 25(OH)-D, BGP and PINP (p < 0.05). ROC curve analysis showed that the AUC of serum miR-338-3p and miR-150-5p was 0.896 with the specificity and sensitivity of 96.66% and 73.47%, which had certain predictive value for the occurrence of renal failure in DN.

CONCLUSIONS

The expression levels of serum miR-383-3p and miR-105-3p were significantly correlated with bone metabolism markers. The combined test can provide new ideas and insights for the clinical treatment of osteoporosis in DN.

Omentin-1 and diabetes: more evidence but far from enough

AIMS AND BACKGROUND

Omentin-1 (oment-1) is a type of adipokines that is mainly expressed in visceral fat tissue. Based on accumulating evidence, oment-1 is closely related to diabetes and its complications. However, so far data about oment-1 and diabetes is fragmented. In this review, we focus on the role of oment-1 on diabetes, including its possible signalling pathways, the correlation of circulating omens-1 levels with diabetes and its complications.

METHODS

The web of PubMed was searched for articles of relevant studies published until February, 2023.

RESULTS AND CONCLUSIONS

Oment-1 might exert its effects by inhibiting the NF-κB pathway and activating the Akt and AMPK-dependent pathways. The level of circulating oment-1 is negatively correlated with the occurrence of type 2 diabetes and some complications, including diabetic vascular disease, cardiomyopathy, and retinopathy, which can be affected by anti-diabetic therapies. Oment-1 could be a promising marker for screening and targeted therapy for diabetes and its complications; however, more studies are still needed.

Omentin reduces venous neointimal hyperplasia in arteriovenous fistula through hypoxia-inducible factor-1 alpha inhibition

Arteriovenous fistula (AVF) failure often involves venous neointimal hyperplasia (VNH) driven by elevated hypoxia-inducible factor-1 alpha (HIF-1α) in the venous wall. Omentin, known for its anti-inflammatory and anti-hyperplasia properties, has an uncertain role in early AVF failure. This study investigates omentin's impact on VNH using a chronic renal failure (CRF) rabbit model. The CRF rabbit model of AVF received omentin-expressing adenoviral vector or control β-gal vector to assess omentin's effects on VNH. Human vascular smooth muscle cells (HVSMCs), stimulated with tumor necrosis factor-α (TNF-α), were exposed to recombinant human omentin (Rh-OMT) to study its influence on cell proliferation and migration. The AMP-activated protein kinase (AMPK) inhibitor compound C and the mammalian target of rapamycin (mTOR) activator MHY1485 were employed to explore omentin's mechanisms in VNH reduction through HIF-1α inhibition. Omentin treatment reduced VNH in CRF rabbits, concomitant with HIF-1α down-regulation and the suppression of downstream factors, including vascular endothelial growth factor and matrix metalloproteinases. Rh-OMT inhibited TNF-α-induced HVSMC proliferation and migration by modulating both cell cycle and cell adhesion proteins. Additionally, omentin reduced HIF-1α expression through the AMPK/mTOR pathway activation. Notably, the blockade of AMPK/mTOR signaling reversed omentin-mediated inhibition of VNH, cell proliferation, and migration, both in vivo and in vitro. In conclusion, omentin mitigates VNH post-AVF creation by restraining HIF-1α via AMPK/mTOR signaling. Strategies boosting circulating omentin levels may offer promise in averting AVF failure.

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.

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.

Plasma EBF1 as a Novel Biomarker for Postmenopausal Osteoporosis

Postmenopausal osteoporosis (OPO) is one of the most common types of primary osteoporosis. There is currently lack of a plasma biomarker for sensitive and early diagnosis of OPO. Here we aimed to explore the potential of early B cell factor 1 (EBF1) as a new plasma biomarker of OPO. Quantitative real-time PCR was used to measure the plasma EBF1 levels. Absorptiometry markers, such as lumbar spine (LS) bone mineral density (BMD) and LS T score were obtained after X-ray scans. Biochemical analyses used to measure osteopontin (OPN), β-isomerized C-terminal telopeptides and total N-terminal procollagen of type-I collagen levels of patients with osteopenia (OPE, n = 81), osteoporosis (OPO, n = 98) as well as healthy subjects (NC, n = 110). Quantitative real-time PCR was used to measure the plasma levels of PAX5 and GSTP1, which are target genes of EBF1. EBF1 was downregulated in OPO patients. Levels of EBF1 were positively correlated to clinicopathological characteristics, including LS BMD and LS T scores, and negatively correlated to OPN and total N-terminal procollagen of type-I collagen levels. Increased PAX5 and GSTP1 levels also demonstrated strong correlations with higher EBF1, LS BMD and LS T score. Anti-osteoporotic treatment resulted in significant upregulation of EBF1, PAX5 and GSTP1 at 6 mo after treatment. Our study suggests that plasma EBF1 is a potential biomarker for diagnosing and assessing treatment outcome of OPO.

Lower Visceral Fat Area in Patients with Type 2 Diabetic Peripheral Neuropathy

OBJECTIVE

There is preliminary evidence that visceral fat area (VFA) was associated with the presence of type 2 diabetic peripheral neuropathy (DPN) in the Korean population; however, no studies have reported the association in Chinese population. The purpose of this study was to explore the possible correlation of VFA with DPN in such a population.

METHODS

A total of 2498 hospitalized patients with type 2 diabetes mellitus (T2DM) undergone VFA measurement, and were divided into DPN group (n=900) and non-DPN group (n=1594). The association of VFA with the presence of DPN was evaluated by correlation and multiple logistic regression analyses, generalized additive model with a smooth curve fitting, and receiver operating characteristic (ROC) curve analysis.

RESULTS

The VFA was significantly lower in the DPN group than in the non-DPN group (P < 0.001). VFA was significantly and positively associated with sural nerve conduction velocity (SNCV) and amplitude potential (SNAP) and negatively associated with the presence of DPN (all P< 0.001); there was no significant difference in the curve fitting (P = 0.344). Multivariate logistic regression analysis showed that the risk of presence of DPN decreased progressively across the VFA quartiles (P for trend < 0.001) and was significantly lower in patients in the highest VFA quartile than in those in the lowest quartile (OR: 0.382, 95% CI 0.151-0.968, P< 0.001) after multivariate adjustment. The ROC analysis revealed that the best cut-off value of VFA for predicting the presence of DPN was 50.5cm² (sensitivity 84.40%; specificity 34.00%).

CONCLUSION

These results suggest that lower VFA level may be associated with increased risk of the presence of DPN in T2DM patients.