Neural cell adhesion molecule regulates chondrocyte hypertrophy in chondrogenic differentiation and experimental osteoarthritis

Proteomic Insights Into Early Detection and Progression of Knee Osteoarthritis: Unveiling Molecular Signatures

AIM

Osteoarthritis (OA) is the eleventh most disabling condition, with radiographic classification based on the Kellgren-Lawrence (KL) grading system. Early detection is critical to implement interventions to slow disease progression and improve patient outcomes. Proteomics, as a powerful strategy, could contribute to a better understanding of the disease pathophysiology and its early detection.

OBJECTIVES

The study aims to identify and confirm proteins associated with early detection and their role in the progression of knee OA.

METHODOLOGY

Synovial fluid (SF) and serum samples from the Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, were categorized by KL classification and subjected to SWATHTM analysis in the discovery phase. Seven samples of each OA grade were analyzed. A mass dynamics tool was used for data analysis and visualization. Significant protein expression level was defined as -1≤ log2FC ≥1 with p-value < 0.05, and ELISA was used for validation in a greater number of patients.

RESULTS

29 significantly modulated proteins were observed in osteoarthritis grade comparisons. Cathepsin G (CTSG) and angiotensinogen (AGT) were upregulated, whereas fumarylacetoacetase (FAH) and neural cell adhesion molecule 1 (NCAM1) were downregulated with radiographic disease progression, as validated by ELISA. CTSG, AGT, and NCAM1 showed good sensitivity and specificity in discriminating between early and late OA grades. Notably, serum and synovial fluid levels of AGT and NCAM1 exhibited significant correlation.

CONCLUSION

This is one of the first studies to comprehensively analyze proteins associated with OA progression. Additionally, the identified protein signatures have great potential for OA progression and differential diagnosis of early and late-stage OA.

Neuropilin2 in Mesenchymal Stromal Cells as a Potential Novel Therapeutic Target in Myelofibrosis

Bone marrow fibrosis in myeloproliferative neoplasm (MPN), myelodysplastic syndromes (MDS), MPN/MDS overlap syndromes and acute myeloid leukemia (AML) is associated with poor prognosis and early treatment failure. Myelofibrosis (MF) is accompanied by reprogramming of multipotent bone marrow mesenchymal stromal cells (MSC) into osteoid and fiber-producing stromal cells. We demonstrate NRP2 and osteolineage marker NCAM1 (neural cell adhesion molecule 1) expression within the endosteal niche in normal bone marrow and aberrantly in MPN, MDS MPN/MDS overlap syndromes and AML (n = 99), as assessed by immunohistochemistry. Increased and diffuse expression in mesenchymal stromal cells and osteoblasts correlates with high MF grade in MPN (p < 0.05 for NRP2 and NCAM1). Single cell RNA sequencing (scRNAseq) re-analysis demonstrated NRP2 expression in endothelial cells and partial co-expression of NRP2 and NCAM1 in normal MSC and osteoblasts. Potential ligands included transforming growth factor β1 (TGFB1) from osteoblasts and megakaryocytes. Murine ThPO and JAK2V617F myelofibrosis models showed co-expression of Nrp2 and Ncam1 in osteolineage cells, while fibrosis-promoting MSC only express Nrp2. In vitro experiments with MC3T3-E1 pre-osteoblasts and analysis of Nrp2-/- mouse femurs suggest that Nrp2 is functionally involved in osteogenesis. In summary, NRP2 represents a potential novel druggable target in patients with myelofibrosis.

Identification of diagnostic biomarkers for osteoarthritis through bioinformatics and machine learning

Osteoarthritis (OA) is a prevalent degenerative joint disease characterized by cartilage degradation, inflammatory arthritis, and joint dysfunction. Currently, there is a lack of effective early diagnostic methods and treatment strategies for OA. Bioinformatics and biomarker research provide new possibilities for early detection and personalized therapy of OA. In this study, we investigated the molecular mechanisms of OA and important signaling pathways involved in disease progression through bioinformatics analysis. Firstly, using the limma package, we analyzed the differentially expressed genes (DEGs) between normal healthy samples and OA cartilage tissue samples. These DEGs were found to be primarily involved in biological processes such as extracellular matrix (ECM) binding, immune receptor activity, and cytokine activity, as well as signaling pathways including cytokine receptors, ECM-receptor interaction, and PI3K-Akt. Gene set enrichment analysis revealed that in the OA group, signaling pathways such as AMPK, B cell receptor, IL-17, and PPAR were downregulated, while calcium signaling pathway, cell adhesion molecules, ECM-receptor interaction, TGF-β signaling pathway, and Wnt signaling pathway were upregulated. Additionally, we constructed a co-expression module network using WGCNA and identified key modules associated with OA, from which we selected 7 most predictive OA characteristic genes. Among them, ANTXR1, KCNS3, SGCD, and LIN7A were correlated with the level of immune cell infiltration. This study elucidates the mechanisms underlying the development of OA and identifies potential diagnostic markers and therapeutic targets, providing important insights for early diagnosis and treatment of OA.

Common changes in rat cortical gene expression after antidepressant drug treatment: Impacts on metabolism of polyamines, mRNA splicing, regulation of RAS by GAPs, neddylation and GPCR ligand binding

OBJECTIVES

This study sought to identify pathways affected by rat cortical RNA that were changed after treatment with fluoxetine or imipramine.

METHODS

We measured levels of cortical RNA in male rats using GeneChip® Rat Exon 1.0 ST Array after treatment with vehicle (0.9% NaCl), fluoxetine (10 mg/kg/day) or imipramine (20 mg/kg/day) for 28 days. Levels of coding and non-coding RNA in vehicle treated rats were compared to those in treated rats using ANOVA in JMP Genomics 13 and the Panther Gene Ontology Classification System was used to identify pathways involving the changed RNAs.

RESULTS

18,876 transcripts were detected; there were highly correlated changes in 1010 levels of RNA after both drug treatments that would principally affect the metabolism of polyamines, mRNA splicing, regulation of RAS by GAPs, neddylation and GPCR ligand binding. Using our previously published data, we compared changes in transcripts after treatment with antipsychotic and mood stabilising drugs.

CONCLUSIONS

Our study shows there are common, correlated, changes in coding and non-coding RNA in the rat cortex after treatment with fluoxetine or imipramine; we propose the pathways affected by these changes are involved in the therapeutic mechanisms of action of antidepressant drugs.

Identification of key genes and pathways associated with sex difference in osteoarthritis based on bioinformatics analysis

OBJECTIVES

The present study aimed to identify different key genes and pathways between postmenopausal females and males by studying differentially expressed genes (DEGs).

METHODS

GSE32317 and GSE55457 gene expression data were downloaded from the GEO database, and DEGs were discovered using R software to obtain overlapping DEGs. The interaction between overlapping DEGs was further analyzed by establishing the protein-protein interaction (PPI) network. Finally, GO and KEGG were used for enrichment analysis.

RESULTS

924 overlapping DEGs between postmenopausal women and men with osteoarthritis (OA) were identified, including 674 up-regulated genes and 249 down-regulated ones. And 10 hub genes were identified in the PPI network, including BMP4, KDM6A, JMJD1C, NFATC1, PRKX, SRF, ZFX, LAMTOR5, UFD1L and AMBN. The findings of the functional enrichment analysis suggested that these genes were predominantly expressed in MAPK signaling pathway as well as the Thyroid hormone signaling pathway, indicating that those two pathways may be involved in onset and disease progression of OA in postmenopausal patients.

CONCLUSION

BMP4, KDM6A, JMJD1C, PRKX, ZFX and LAMTOR5 are expected to play crucial roles in disease development in postmenopausal patients and may be ideal targets or prognostic markers for the treatment of OA.

Ex Vivo Generation and Characterization of Human Hyaline and Elastic Cartilaginous Microtissues for Tissue Engineering Applications

Considering the high prevalence of cartilage-associated pathologies, low self-repair capacity and limitations of current repair techniques, tissue engineering (TE) strategies have emerged as a promising alternative in this field. Three-dimensional culture techniques have gained attention in recent years, showing their ability to provide the most biomimetic environment for the cells under culture conditions, enabling the cells to fabricate natural, 3D functional microtissues (MTs). In this sense, the aim of this study was to generate, characterize and compare scaffold-free human hyaline and elastic cartilage-derived MTs (HC-MTs and EC-MTs, respectively) under expansion (EM) and chondrogenic media (CM). MTs were generated by using agarose microchips and evaluated ex vivo for 28 days. The MTs generated were subjected to morphometric assessment and cell viability, metabolic activity and histological analyses. Results suggest that the use of CM improves the biomimicry of the MTs obtained in terms of morphology, viability and extracellular matrix (ECM) synthesis with respect to the use of EM. Moreover, the overall results indicate a faster and more sensitive response of the EC-derived cells to the use of CM as compared to HC chondrocytes. Finally, future preclinical in vivo studies are still needed to determine the potential clinical usefulness of these novel advanced therapy products.

Investigating the molecular control of deer antler extract on articular cartilage

BACKGROUND

Deer antler is considered as a precious traditional Chinese medicinal material and has been widely used to reinforce kidney's yang, nourish essence, and strengthen bone function. The most prominent bioactive components in deer antler are water-soluble proteins that play potential roles in bone formation and repair. The aim of this study was to explore the molecular control and therapeutic targets of deer antler extract (DAE) on articular cartilage.

METHODS

DAE was prepared as previously described. All rats were randomly divided into Blank group and DAE group (10 rats per group) after 7-day adaptive feeding. The rats in DAE group were orally administrated with DAE at a dose of 0.2 g/kg per day for 3 weeks, and the rats in Blank group were fed with drinking water. Total RNA was isolated from the articular cartilage of knee joints. RNA sequencing (RNA-seq) experiment combined with quantitative real-time polymerase chain reaction (qRT-PCR) verification assay was carried out to explore the molecular control and therapeutic targets of DAE on articular cartilage.

RESULTS

We demonstrated that DAE significantly increased the expression levels of functional genes involved in cartilage formation, growth, and repair and decreased the expression levels of susceptibility genes involved in the pathophysiology of osteoarthritis.

CONCLUSIONS

DAE might serve as a candidate supplement for maintaining cartilage homeostasis and preventing cartilage degeneration and inflammation. These effects were possibly achieved by accelerating the expression of functional genes involved in chondrocyte commitment, survival, proliferation, and differentiation and suppressing the expression of susceptibility genes involved in the pathophysiology of osteoarthritis. Thus, our findings will contribute towards deepening the knowledge about the molecular control and therapeutic targets of DAE on the treatment of cartilage-related diseases.

Neural Cell Adhesion Molecule Regulates Osteoblastic Differentiation Through Wnt/β-Catenin and PI3K-Akt Signaling Pathways in MC3T3-E1 Cells

Neural cell adhesion molecule (NCAM) is involved in cell multi-directional differentiation, but its role in osteoblast differentiation is still poorly understood. In the present study, we investigated whether and how NCAM regulates osteoblastic differentiation. We found that NCAM silencing inhibited osteoblast differentiation in pre-osteoblastic MC3T3-E1 cells. The function of NCAM was further confirmed in NCAM-deficient mesenchymal stem cells (MSCs), which also had a phenotype with reduced osteoblastic potential. Moreover, NCAM silencing induced decrease of Wnt/β-catenin and Akt activation. The Wnt inhibitor blocked osteoblast differentiation, and the Wnt activator recovered osteoblast differentiation in NCAM-silenced MC3T3-E1 cells. We lastly demonstrated that osteoblast differentiation of MC3T3-E1 cells was inhibited by the PI3K-Akt inhibitor. In conclusion, these results demonstrate that NCAM silencing inhibited osteoblastic differentiation through inactivation of Wnt/β-catenin and PI3K-Akt signaling pathways.

A comprehensive understanding about the pharmacological effect of diallyl disulfide other than its anti-carcinogenic activities

Diallyl disulfide (DADS), an oil-soluble sulfur compound that is responsible for the biological effects of garlic, displays numerous biological activities, among which its anti-cancer activities are the most famous ones. In recent years, the pharmacological effects of DADS other than its anti-carcinogenic activities have attracted numerous attentions. For example, it has been reported that DADS can prevent the microglia-mediated neuroinflammatory response and depression-like behaviors in mice. In the cardiovascular system, DADS administration was found to ameliorate the isoproterenol- or streptozotocin-induced cardiac dysfunction via the activation of the nuclear factor E2-related factor 2 (Nrf2) and insulin-like growth factor (IGF)-phosphatidylinositol-3-kinase (PI3K)-protein kinase B (Akt) signaling. DADS administration can also produce neuroprotective effects in animal models of Alzheimer's disease and protect the heart, endothelium, liver, lung, and kidney against cellular or tissue damages induced by various toxic factors, such as the oxidized-low density lipoprotein (ox-LDL), carbon tetrachloride (CCl₄), ethanol, acetaminophen, Cis-Diammine Dichloroplatinum (CisPt), and gentamicin. The major mechanisms of action of DADS in disease prevention and/or treatment include inhibition of inflammation, oxidative stress, and cellular apoptosis. Mechanisms, including the activation of Akt, extracellular signal-regulated kinase 1/2 (ERK1/2), protein kinase A (PKA), and cyclic adenosine monophosphate-response element binding protein (CREB) and the inhibition of histone deacetylases (HDACs), can also mediate the cellular protective effects of DADS in different tissues and organs. In this review, we summarize and discuss the pharmacological effects of DADS other than its anti-carcinogenic activities, aiming to reveal more possibilities for DADS in disease prevention and/or treatment.

Neural cell adhesion molecule regulates chondrocyte hypertrophy in chondrogenic differentiation and experimental osteoarthritis

Chondrocyte hypertrophy-like change is an important pathological process of osteoarthritis (OA), but the mechanism remains largely unknown. Neural cell adhesion molecule (NCAM) is highly expressed and involved in the chondrocyte differentiation of mesenchymal stem cells (MSCs). In this study, we found that NCAM deficiency accelerates chondrocyte hypertrophy in articular cartilage and growth plate of OA mice. NCAM deficiency leads to hypertrophic chondrocyte differentiation in both murine MSCs and chondrogenic cells, in which extracellular signal-regulated kinase (ERK) signaling plays an important role. Moreover, NCAM expression is downregulated in an interleukin-1β-stimulated OA cellular model and monosodium iodoacetate-induced OA rats. Overexpression of NCAM substantially inhibits hypertrophic differentiation in the OA cellular model. In conclusion, NCAM could inhibit hypertrophic chondrocyte differentiation of MSCs by inhibiting ERK signaling and reduce chondrocyte hypertrophy in experimental OA model, suggesting the potential utility of NCAM as a novel therapeutic target for alleviating chondrocyte hypertrophy of OA.