Attenuated levels of ghrelin in synovial fluid is related to the disease severity of ankle post-traumatic osteoarthritis

Potential Roles of Inflammation on Post-Traumatic Osteoarthritis of the Ankle

Post-traumatic osteoarthritis of the ankle (PTOA) is frequently observed following a debilitating consequence of intra-articular ankle fractures. Numerous risk factors contribute to the pathogenesis of PTOA, including articular incongruity, joint malalignment, and concomitant soft tissue damage. Despite attempts to restore joint anatomy and manage soft tissues to avoid long-term complications after intra-articular ankle fractures, the incidence of PTOA remains markedly elevated. Inflammatory processes triggered by intra-articular ankle fractures have emerged as potential instigators that expedite the progression of PTOA. Injury to the articular cartilage and subchondral bone may lead to the release of inflammatory mediators, which can contribute to cartilage degradation and bone resorption. This study provides a narrative review on the current knowledge concerning the association between inflammation and the development of PTOA following intra-articular ankle fractures. We also discuss novel therapeutic agents that target inflammatory pathways to impede the progression of post-traumatic osteoarthritis after intra-articular ankle fractures. These medication and interventions were summarized within this review article.

Electrogenerated Chemiluminescence Biosensor for Quantization of Matrix Metalloproteinase-3 in Serum via Target-Induced Cleavage of Oligopeptide

A highly sensitive and selective electrogenerated chemiluminescence (ECL) biosensor was developed for the determination of matrix metalloproteinase 3 (MMP-3) in serum via the target-induced cleavage of an oligopeptide. One ECL probe (named as Ir-peptide) was synthesized by covalently linking a new cyclometalated iridium(III) complex ([(3-pba)2Ir(bpy-COOH)](PF6)) (3-pba = 3-(2-pyridyl) benzaldehyde, bpy-COOH = 4'-methyl-2,2'-bipyridine-4-carboxylic acid) with an oligopeptide (CGVPLSLTMGKGGK). An ECL biosensor was fabricated by firstly casting Nafion and gold nanoparticles (AuNPs) on a glassy carbon electrode and then self-assembling both of the ECL probes, 6-mercapto-1-hexanol and zwitterionic peptide, on the electrode surface, from which the AuNPs could be used to amplify the ECL signal and Ir-peptide could serve as an ECL probe to detect the MMP-3. Thanks to the MMP-3-induced cleavage of the oligopeptide contributing to the decrease in ECL intensity and the amplification of the ECL signal using AuNPs, the ECL biosensor could selectively and sensitively quantify MMP-3 in the concentration range of 10-150 ng·mL-1 and with both a limit of quantification (26.7 ng·mL-1) and a limit of detection (8.0 ng·mL-1) via one-step recognition. In addition, the developed ECL biosensor showed good performance in the quantization of MMP-3 in serum samples, with a recovery of 92.6% ± 2.8%-105.6% ± 5.0%. An increased level of MMP-3 was found in the serum of rheumatoid arthritis patients compared with that of healthy people. This work provides a sensitive and selective biosensing method for the detection of MMP-3 in human serum, which is promising in the identification of patients with rheumatoid arthritis.

Role and molecular mechanism of ghrelin in degenerative musculoskeletal disorders

Ghrelin is a brain-gut peptide, and the first 28-peptide that was found in the gastric mucosa. It has a growth hormone (GH)-releasing hormone-like effect and can potently promote the release of GH from pituitary GH cells; however, it is unable to stimulate GH synthesis. Therefore, ghrelin is believed to play a role in promoting bone growth and development. The correlation between ghrelin and some degenerative diseases of the musculoskeletal system has been reported recently, and ghrelin may be one of the factors influencing degenerative pathologies, such as osteoporosis, osteoarthritis, sarcopenia and intervertebral disc degeneration. With population ageing, the risk of health problems caused by degenerative diseases of the musculoskeletal system gradually increases. In this article, the roles of ghrelin in musculoskeletal disorders are summarized to reveal the potential effects of ghrelin as a key target in the treatment of related bone and muscle diseases and the need for further research.

Evaluation of ghrelin as a distinguishing marker for human articular cartilage-derived chondrocytes and chondroprogenitors

Purpose of the study

Cell-based therapeutics for articular cartilage repair primarily employed bone marrow-derived mesenchymal stem cells and chondrocytes. Research to overcome their limitation of formation of a functionally poor fibro-hyaline type of repair tissue led to the discovery of chondroprogenitors (CPCs), cartilage resident stem cells. These cells isolated by adhesion assay using fibronectin (FAA-CPs) and migration of progenitors from explants (MCPs) display higher chondrogenic and lower terminal differentiation potential. During in-vitro culture, chondrocytes tend to de-differentiate and acquire characteristics similar to stem cells, thus making it challenging to distinguish them from other cell groups. Ghrelin, a cytoplasmic growth hormone secretagogue, has been proposed to play a vital role in chondrogenesis, with reports of its higher expression in chondrocytes than BM-MSCs. The aim of this study was to compare the mRNA expression of Ghrelin between BM-MSCs, chondrocytes, FAA-CPs and MCP and the possibility of it serving as a distinguishing marker.

Methods

The four populations isolated from three human osteoarthritic knee joints were characterised by CD marker expression for positive (CD 90, CD73 and CD105) and negative (HLA-DR, CD34 and CD45) MSC markers and trilineage differentiation (adipogenic, osteogenic and chondrogenic) and subjected to qRT-PCR to assess Ghrelin's gene expression.

Results

This study showed that all groups exhibited similar expression of CD markers and multilineage potential. Though chondrocytes showed greater expression of Ghrelin, it was not statistically significant to classify it as a distinguishing marker between these cell populations.

Conclusion

Ghrelin does not serve to differentiate the subpopulations in terms of their mRNA expression. Further evaluation using their associated enzymes and receptors could provide valuable information to uncover their potential as unequivocal biomarkers.

Ghrelin is associated with anti-mullerian hormone levels in Chinese systemic lupus erythematosus

PROBLEM

Ghrelin has been thought of as a potential link between energy homeostasis and fertility. The aim of this study was to evaluate levels of ghrelin in obese and non-obese systemic lupus erythematosus (SLE) patients, and to reveal a possible association between ghrelin and Anti-Mullerian hormone (AMH) in SLE patients.

METHOD OF STUDY

One hundred SLE patients (50 obese and 50 non-obese subjects) at childbearing age and 100 age-matched healthy controls (50 obese and 50 non-obese subjects) were included. Ghrelin and leptin were examined by enzyme-linked immunosorbent assay. AMH was tested through electrochemiluminescence. Demographics, clinical and laboratory indicators were obtained from medical records.

RESULTS

Ghrelin levels were significantly lower in obese SLE patients than non-obese SLE patients (P = .000) and obese controls (P = .002). Non-obese SLE patients and non-obese controls had similar ghrelin levels. Ghrelin levels were correlated positively with AMH (r = .2683, P = .0070) in SLE patients. And ghrelin were negatively associated with leptin (r = -.1969, P = .0496) and BMI (r = - .2401, P = .0161).

CONCLUSION

Our results provide evidence for a potential relationship between ghrelin and AMH in SLE patients, indicating that ghrelin may play a part in energy homeostasis and ovarian damage of SLE patients.

Reduced miR-519d-3p levels in the synovium and synovial fluid facilitate the progression of post-traumatic osteoarthritis by targeting VEGF

The present study aimed to investigate the expression and clinical significance of miR-519d-3p in patients with post-traumatic osteoarthritis (PTOA). The levels of miR-519d-3p in the synovium and synovial fluid (SF) of all subjects were detected by reverse transcription-quantitative polymerase chain reaction. The results of the present study demonstrated that the levels of miR-519d-3p in the synovium and SF of patients with PTOA were significantly lower, but that the VEGF content was significantly higher, compared with that of control group. Dual-luciferase reporter and Western blot assays demonstrated that VEGF was a target gene of miR-519d-3p. Furthermore, miR-519d-3p inhibitor-induced cell apoptosis, and cell cycle arrest could be partially reversed by silencing VEGF. Additionally, the level of miR-519d-3p in the synovium and SF of patients with PTOA was negatively correlated with the level of VEGF. ROC analysis demonstrated that miR-519d-3p levels in the synovium and SF could effectively differentiate patients with PTOA from healthy controls, with areas under the ROC curve of 0.928 and 0.896, respectively. In conclusion, reduction of miR-519d-3p in the synovium and SF resulted in the upregulation of VEGF in patients with PTOA, and miR-519d-3p may be a potential therapeutic target of PTOA.