Explore the vast range of titles available.

In order to characterize the molecular bases of mineralizing cell evolution, we targeted type X collagen, a nonfibrillar network forming collagen encoded by the Col10a1 gene. It is involved in the process of endochondral ossification in ray-finned fishes and tetrapods (Osteichthyes), but until now unknown in cartilaginous fishes (Chondrichthyes). We show that holocephalans and elasmobranchs have respectively five and six tandemly duplicated Col10a1 gene copies that display conserved genomic synteny with osteichthyan Col10a1 genes. All Col10a1 genes in the catshark Scyliorhinus canicula are expressed in ameloblasts and/or odontoblasts of teeth and scales, during the stages of extracellular matrix protein secretion and mineralization. Only one duplicate is expressed in the endoskeletal (vertebral) mineralizing tissues. We also show that the expression of type X collagen is present in teeth of two osteichthyans, the zebrafish Danio rerio and the western clawed frog Xenopus tropicalis, indicating an ancestral jawed vertebrate involvement of type X collagen in odontode formation. Our findings push the origin of Col10a1 gene prior to the divergence of osteichthyans and chondrichthyans, and demonstrate its ancestral association with mineralization of both the odontode skeleton and the endoskeleton.

Abstract Context Height velocity (HV) is difficult to assess because growth is very slow. The current practice of calculating it from measurements taken at several-month intervals is insufficient for managing children with growth disorders. We identified a bone growth by-product (collagen X biomarker, CXM) in blood that in preliminary analysis in healthy children correlated strongly with conventionally determined HV and displayed a pattern resembling published norms for HV vs age. Objective The goal was to confirm our initial observations supporting the utility of CXM as an HV biomarker in a larger number of individuals and establish working reference ranges for future studies. Design, Settings, and Participants CXM was assessed in archived blood samples from 302 healthy children and 10 healthy adults yielding 961 CXM measurements. A total of 432 measurements were plotted by age, and sex-specific reference ranges were calculated. Serial values from 116 participants were plotted against observed HV. Matched plasma, serum, and dried blood spot readings were compared. Results A correlation of blood CXM with conventional HV was confirmed. Scatter plots of CXM vs age showed a similar pattern to current HV norms, and CXM levels demarcated the pubertal growth spurt both in girls and boys. CXM levels differed little in matched serum, plasma, and dried blood spot samples. Conclusions Blood CXM offers a potential means to estimate HV in real time. Our results establish sex-specific, working reference ranges for assessing skeletal growth, especially over time. CXM stability in stored samples makes it well suited for retrospective studies.

The short-limbed dwarfism metaphyseal chondrodysplasia type Schmid (MCDS) is linked to mutations in type X collagen, which increase ER stress by inducing misfolding of the mutant protein and subsequently disrupting hypertrophic chondrocyte differentiation. Here, we show that carbamazepine (CBZ), an autophagy-stimulating drug that is clinically approved for the treatment of seizures and bipolar disease, reduced the ER stress induced by 4 different MCDS-causing mutant forms of collagen X in human cell culture. Depending on the nature of the mutation, CBZ application stimulated proteolysis of misfolded collagen X by either autophagy or proteasomal degradation, thereby reducing intracellular accumulation of mutant collagen. In MCDS mice expressing the Col10a1.pN617K mutation, CBZ reduced the MCDS-associated expansion of the growth plate hypertrophic zone, attenuated enhanced expression of ER stress markers such as Bip and Atf4, increased bone growth, and reduced skeletal dysplasia. CBZ produced these beneficial effects by reducing the MCDS-associated abnormalities in hypertrophic chondrocyte differentiation. Stimulation of intracellular proteolysis using CBZ treatment may therefore be a clinically viable way of treating the ER stress-associated dwarfism MCDS.

Background Ovarian cancer (OC) represents one of the most lethal gynecological malignancies. Extracellular matrix is present in both primary and metastatic tumors and exhibit significant functional heterogeneity, adaptability and resilience. These cells are crucial for cancer progression because of their complex signaling interactions with different cell types in the tumor microenvironment. The collagen type X alpha 1 chain (COL10A1) is notably overexpressed in extracellular matrix and is closely associated with the initiation and progression of the disease. However, the role of the COL10A1 gene in extracellular matrix remains unexplored. Methods Here, we identified the differentially expressed gene COL10A1 via multiple databases, including the GEO database and the TCGA-OV dataset. We subsequently performed further bioinformatics analyses concerning COL10A1. The external datasets were ultimately analyzed, and clinical samples were collected and examined via immunohistochemistry and quantitative reverse transcription polymerase chain reaction (qRT‒PCR). Results Our findings revealed that COL10A1 expression was markedly elevated in OC extracellular matrix and correlated with adverse clinicopathological characteristics and poorer patient prognosis. Functional enrichment analyses indicated that COL10A1 may facilitate tumorigenesis and progression by modulating several pathways associated with cellular growth, metabolism, proliferation, and survival, particularly the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway and extracellular matrix (ECM)-receptor interactions. Furthermore, we observed that COL10A1 was associated with the infiltration of various immune cells and immune checkpoints. Importantly, in clinical samples, COL10A1 expression was significantly increased in OC, which was related to unfavorable clinicopathological features and poorer patient prognosis. Conclusions Our research indicates that extracellular matrix with elevated COL10A1 expression may enhance OC progression through the modulation of macrophage. Consequently, COL10A1 may serve as a novel biomarker for predicting OC prognosis and provides a promising avenue for developing therapeutic strategies targeting the tumor microenvironment.

Zebrafish are now widely used to study skeletal development and bone-related diseases. To that end, understanding osteoblast differentiation and function, the expression of essential transcription factors, signaling molecules, and extracellular matrix proteins is crucial. We isolated Sp7-expressing osteoblasts from 4-day-old larvae using a fluorescent reporter. We identified two distinct subpopulations and characterized their specific transcriptome as well as their structural, regulatory, and signaling profile. Based on their differential expression in these subpopulations, we generated mutants for the extracellular matrix protein genes col10a1a and fbln1 to study their functions. The col10a1a−/− mutant larvae display reduced chondrocranium size and decreased bone mineralization, while in adults a reduced vertebral thickness and tissue mineral density, and fusion of the caudal fin vertebrae were observed. In contrast, fbln1−/− mutants showed an increased mineralization of cranial elements and a reduced ceratohyal angle in larvae, while in adults a significantly increased vertebral centra thickness, length, volume, surface area, and tissue mineral density was observed. In addition, absence of the opercle specifically on the right side was observed. Transcriptomic analysis reveals up-regulation of genes involved in collagen biosynthesis and down-regulation of Fgf8 signaling in fbln1−/− mutants. Taken together, our results highlight the importance of bone extracellular matrix protein genes col10a1a and fbln1 in skeletal development and homeostasis.

Background Identification of biomarkers to predict the risk of healing delays are of huge clinical interest since 10% of fracture patients progress to delayed or non-union. During endochondral ossification, which takes place in mechanically unstable regions, the bone regenerates through a cartilage intermediate. We previously identified miR-1246, miR-335-5p and miR-193a-5p as fracture-related biomarkers in patient serum, but they appear not to have a functional role in an in vitro model of direct ossification. However, their involvement in other processes related to fracture healing cannot be ruled out and the most common healing process in fracture repair is secondary healing by way of endochondral ossification. Therefore, this study aims to explore the role of miR-1246, miR-335-5p and miR-193a-5p during in vitro endochondral differentiation of human bone marrow-derived mesenchymal stromal cells (BMSCs). Methods The activity of miR-1246, miR-335-5p, and miR-193a-5p was transiently inhibited just before pellet formation and the start of chondrogenic differentiation in human BMSCs ( n  = 5 donors), serving as a model for early endochondral ossification. The effect of miRNA inhibition was assessed by histology (Safranin O/Fast Green), immunohistochemistry (type II and type X collagen), and gene expression analysis by bulk RNA sequencing and RT-qPCR. Results Inhibition of miR-1246 and miR-335-5p enhanced chondrogenic and hypertrophic differentiation in BMSCs from three out of five donors, while miR-193a-5p inhibition had minimal effect. Donors were categorized as “responders” or “non-responders” based on histological and gene expression profiles. RNA sequencing and RT-qPCR identified differentially expressed genes, including a 1.6 and 1.5-fold upregulation of GDF5 and CCN5 respectively ( p  < 0.05) and downregulation of SKIL (fold change: 1.3, p  = 0.0563) after miR-335-5p inhibition, while the same genes were unaltered by miRNA inhibition in non-responders, suggesting donor-specific responses to miRNA inhibition during early chondrogenesis. Conclusions These results suggest that miR-335-5p and miR-1246 have a regulatory effect on endochondral ossification, and genes regulated by miR-335-5p are involved in TGF-β signalling. The function of these miRNAs in human bone formation and repair should be further investigated to validate their potential role as prognostic markers in fracture healing. Graphical Abstract

Osteoblast-derived semaphorin3A (Sema3A) has been reported to be involved in bone protection, and Sema3A knockout mice have been reported to exhibit chondrodysplasia. From these reports, Sema3A is considered to be involved in chondrogenic differentiation and skeletal formation, but there are many unclear points about its function and mechanism in chondrogenic differentiation. This study investigated the pharmacological effects of Sema3A in chondrogenic differentiation. The amount of Sema3A secreted into the culture supernatant was measured using an enzyme-linked immunosorbent assay. The expression of chondrogenic differentiation-related factors, such as Type II collagen (COL2A1), Aggrecan (ACAN), hyaluronan synthase 2 (HAS2), SRY-box transcription factor 9 (Sox9), Runt-related transcription factor 2 (Runx2), and Type X collagen (COL10A1) in ATDC5 cells treated with Sema3A (1,10 and 100 ng/mL) was examined using real-time reverse transcription polymerase chain reaction. Further, to assess the deposition of total glycosaminoglycans during chondrogenic differentiation, ATDC5 cells were stained with Alcian Blue. Moreover, the amount of hyaluronan in the culture supernatant was measured by enzyme-linked immunosorbent assay. The addition of Sema3A to cultured ATDC5 cells increased the expression of Sox9, Runx2, COL2A1, ACAN, HAS2, and COL10A1 during chondrogenic differentiation. Moreover, it enhanced total proteoglycan and hyaluronan synthesis. Further, Sema3A was upregulated in the early stages of chondrogenic differentiation, and its secretion decreased later. Sema3A increases extracellular matrix production and promotes chondrogenic differentiation. To the best of our knowledge, this is the first study to demonstrate the role of Sema3A on chondrogenic differentiation.

Meniscus injury is frequently encountered in clinical practice. Current surgical therapy involving partial or complete meniscectomy relieves pain in the short‐term but often leads to osteoarthritis (OA) in the long‐term. In this study, we report a new strategy of articular cartilage protection by intra‐articular injection of novel human meniscus stem/progenitor cells (hMeSPCs). We found that hMeSPCs displayed both mesenchymal stem cell characteristics and high expression levels of collagen II. In the rat meniscus injury model, hMeSPC transplantation not only led to more neo‐tissue formation and better‐defined shape but also resulted in more rounded cells and matured extracellular matrix. Stromal cell‐derived factor‐1 (SDF‐1) enhanced the migration of hMeSPCs, whereas AMD3100 abolished the chemotactic effects of SDF‐1 on hMeSPCs, both in vitro and in vivo. In an experimental OA model, transplantation of hMeSPCs effectively protected articular cartilage, as evidenced by reduced expression of OA markers such as collagen I, collagen X, and hypoxia‐inducible factor 2α but increased expression of collagen II. Our study demonstrated for the first time that intra‐articular injection of hMeSPCs enhanced meniscus regeneration through the SDF‐1/CXCR4 axis. Our study highlights a new strategy of intra‐articular injection of hMeSPCs for meniscus regeneration. Current surgical therapy involving partial or complete meniscectomy relieves pain in the short‐term but often leads to osteoarthritis in the long‐term. Results show that intra‐articular injection of human meniscus stem/progenitor cells enhanced meniscus regeneration through the stromal cell‐derived factor‐1/CXCR4 axis. This is a new strategy of intra‐articular injection of human meniscus stem/progenitor cells for meniscus regeneration.

Background Psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA) are chronic inflammatory rheumatic diseases with complex origins. Both are characterized by altered extracellular matrix remodeling in joints and entheses that results in destructive and osteochondral proliferative lesions. There is a need for biomarkers reflecting core disease pathways for diagnosis and disease mapping. Pro-C2 reflects mature cartilage collagen type IIB formation, while C-Col10 represents turnover of type X collagen, which is exclusively expressed by hypertrophic chondrocytes. The objectives of this study were to study cartilage metabolism in axSpA and PsA by assessing Pro-C2 and C-Col10 and to evaluate their diagnostic utility against a healthy reference population. Methods Patients with PsA ( n  = 101) or axSpA ( n  = 110) were recruited consecutively from three rheumatology outpatient clinics. Demographic and clinical disease measures were recorded. Pro-C2 and C-Col10 were quantified in serum by using newly developed and specific competitive enzyme-linked immunosorbent assays based on monoclonal antibodies. One-way analysis of variance and Tukey’s multiple comparison tests were performed on log-transformed data. ROC curve analysis was carried out to evaluate their discriminative power. Results Pro-C2 levels in serum were significantly increased in both axSpA (median concentration 1.11 ng/ml, 0.67–1.64) and PsA (median concentration 1.03 ng/ml, 0.53–1.47) compared with healthy controls (median concentration 0.30 ng/ml, 0.16–0.41) ( p  < 0.0001). Pro-C2 did not differ according to treatment. C-Col10 was slightly but equally elevated in the PsA and axSpA groups vs. the control group, but it was significantly lower in patients with axSpA undergoing tumor necrosis factor-α inhibitor (TNFi) treatment. ROC curve analysis revealed AUCs of 0.85 (95 % CI 0.79–0.89) for axSpA and 0.81 (95 % CI 0.75–0.86) for PsA. Conclusions These findings indicate that cartilage collagen metabolism was enhanced in the axSpA and PsA groups compared with the healthy control group. The lower C-Col10 level in patients with axSpA undergoing TNFi treatment may reflect that hypertrophic chondrocytes in axSpA are targeted by TNFi. ROC curve analysis showed a diagnostic potential for Pro-C2 in axSpA and PsA.

Indian hedgehog (Ihh) regulates endochondral ossification in both a parathyroid hormone-related protein (PTHrP)-dependent and -independent manner by activating transcriptional mediator Gli2. However, the molecular mechanisms underlying these processes remain elusive. Here by using in vivo microarray analysis, we identify forkhead box C1 (Foxc1) as a transcriptional partner of Gli2. Foxc1 stimulates expression of Ihh target genes, including PTHrP and Col10a1, through its physical and functional interaction with Gli2. Conversely, a dominant negative Foxc1 inhibits the Ihh target gene expression. In a spontaneous loss of Foxc1 function mouse (Foxc1 ch/ch ), endochondral ossification is delayed and the expression of Ihh target genes inhibited. Moreover, the pathological Foxc1 missense mutation observed in the Axenfeld–Rieger syndrome impairs Gli2–Foxc1 association as well as Ihh function. Our findings suggest that Foxc1 is an important transcriptional partner of Ihh–Gli2 signalling during endochondral ossification, and that disruption of the Foxc1–Gli2 interaction causes skeletal abnormalities observed in the Axenfeld–Rieger syndrome. Skeletal development relies on endochondral ossification. Here the authors show that transcription factors Foxc1 and Gli2 interact to modulate expression of Ihh target genes that control endochondral ossification, and that disruption of this interaction partly underlies skeletal disorders in the Axenfeld–Rieger syndrome.