A critical role for thrombin in regulating chondrocytes catabolism through RNA-Seq and experimental validation
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ABSTRACT: Purpose: To reveal the effects of thrombin on the proliferation, morphology, and gene expression in chondrocytes. Methods: Rat primary chondrocytes were cultured with RS, RP and RPT for 24hours, and RNA was extracted for sequencing. The chondrocytes’ morphology was investigated under inverted microscope. Chondrocyte’s proliferation was evaluated by Edu staining, CCK8 methods and PPI network of proliferation-associated genes. The differential gene expression was visualized using a volcano plot. The variance in expression levels of the genes was visualized by the heatmap. GO-based functional annotation clustering analysis was performed on the upregulated and downregulated DEGs, which included biological process, cellular component, and molecular function. The endoplasmic reticulum of chondrocytes from three groups were labeled by molecular probes. The expression levels of Col2a1 and proteoglycan synthesis were detected by cellular immunofluorescence and Safranin O staining separately. The expression levels of Lox were determined by immunocytochemistry staining. The following genes including Comp, Eln, P3H1 and Colgalt1 were examined by RT-qPCR. The expression of MMPs and Sox9 were evaluated by Western Blot. Further analysis of PPI network was performed, and the corresponding modules were selected. Results: As compared with RP group, chondrocytes proliferation was obvious and normal chondrocytes quickly transformed into fibroblast-like chondrocytes in the presence of RS and RPT. we found that 727 genes were up-regulated, and 1162 genes were down-regulated in Venn diagram through analyzing differentially expressed genes (DEGs). The results of GO analyses showed that both the expression of ECM and MMPs were significantly influenced by RS and RPT. Both the labeled endoplasmic reticulum and the expression of representative genes analyzed from the results of RNA sequencing confirmed that chondrocytes were dominated by catabolism. The expression of ECM, MMPs, inflammatory factors and chemokines were verified at the protein level or at the RNA level which agreed with PPI network and functional modules. Conclusions: Thrombin stimulated the proliferation and promoted the morphology transformation towards fibrotic chondrocytes. Thrombin improved the chondrocytes’ catabolism by regulating the expression of the key enzymes which were responsible for ECM synthesis. Meanwhile thrombin increased the expression of MMPs and chemokines that aimed at extracellular ECM degradation.
Project description:Rat chondrocytes were divided into control group (RP), thrombin group (RPT), and thrombin plus inhibitor group (RPTi). The differential genes were identified by RNA-sequencing, and verified by western blot (WB), quantitative polymerase chain reaction (qPCR), cell immunofluorescence (IF), endoplasmic reticulum (ER) staining, functional enrichment analysis, and Gene Ontology (GO).
Project description:Knowledge of cell signaling pathways that drive human neural crest differentiation into craniofacial chondrocytes is incomplete, yet essential for using stem cells to regenerate craniomaxillofacial structures. To accelerate translational progress, we developed a differentiation protocol that generated self-organizing craniofacial cartilage organoids from human embryonic stem cell-derived neural crest stem cells. Histological staining of cartilage organoids revealed tissue architecture and staining typical of elastic cartilage. Protein and post-translational modification (PTM) mass spectrometry and snRNASeq data showed that chondrocyte organoids expressed robust levels of cartilage extracellular matrix (ECM) components: many collagens, aggrecan, perlecan, proteoglycans, and elastic fibers. We identified two populations of chondroprogenitor cells, mesenchyme cells and nascent chondrocytes and the growth factors involved in paracrine signaling between them. We show that ECM components secreted by chondrocytes not only create a structurally resilient matrix that defines cartilage, but also play a pivotal autocrine cell signaling role to determine chondrocyte fate.
Project description:Transcriptional profiling of mouse chondrocytes cells comparing control untreated chondrocytes cells with chondrocytes cells plated in stiff and soft ECM. Goal was to determine the effects of ECM stiffness on gene expression.
Project description:To explore the cellular response of stem cell derived from human exfoliated deciduous teeth (SHED) in response to inorganic pyrophosphate (PPi). SHED was extracted from human primary exfoliated teeth. The cellular responses including cell proliferation, apoptosis, migration, transcriptomic expression was investigated afterward PPi treatment at the distinct concentration. Additionally, Alizarin red, oil red O, and alcian blue staining were performed to evaluate the multipotency. Inorganic pyrophosphate (PPi) had no although effect on cell cycle, yet enhanced migratory cell, compared to control. Additionally, PPi abolished the gene expression of osteogenic genes and also calcium deposition. Interestingly, the inhibition of mineralization by PPi was not reversed though Pi3K and MAPK family, including ERK, P38, and JNK signalling pathway. On the contrary, PPi induced the ALPL and COL1A1 gene expression and reduced RANKL mRNA and protein in the condition medium, resulting in a decrease of osteoclast formation. The transcriptomic profiles illustrated PPi modulated interferon ⍺/ , TGF-β1, NOTCH signalling pathway, and metabolism of lipid. In summary, our study revealed that PPi enhanced migratory ability, however inhibited osteo/odontogenic, adipogenic and chondrogenic differentiation. This study implicated that PPi can modulate cellular responses of SHED.
Project description:Analysis of early gene expression and how this correlates to MMP gene expression seen at 24 hours. The hypothesis. Results provide important information of the early gene expression that precedes the catabolic expression of MMPs in chondrocytes.
Project description:Extracellular matrix (ECM) assembly/disassembly is a critical regulator for airway epithelial development and remodeling. Airway organoid is widely used in respiratory research, yet there is limited study to indicate the roles and mechanismsof ECM organization in epithelial growth and differentiation by using in vitro organoid system. Moreover, most of current Matrigel-based airway organoids are in basal-out orientation where accessing the apical surface is challenging. We present a novel human apical-out airway organoid using a biochemically defined hybrid hydrogel system. During human nasal epithelial progenitor cells (hNEPCs) differentiation, thegel gradually degraded, leading to the organoid apical surfaces facing outward. The expression and activity of ECM-degrading enzymes, matrix metalloproteinases (MMP7, MMP9, MMP10 and MMP13) increased during organoid differentiation,where inhibition of MMPs significantly suppressed the normal ciliation, resulting in increased goblet cell proportion. Moreover, a decrease of MMPs was found in goblet cell hyperplastic epithelium in inflammatory mucosa. This system reveals essential roles of epithelial-derived MMPs on epithelial cell fate determination, and provides an applicable platform enabling further study for ECM in regulating airway development in health and diseases.
Project description:Corneal injuries remain a major cause of consultation in the ophthalmology clinics worldwide. Repair of corneal wounds is a complex mechanism that involves cell death, migration, proliferation, differentiation, and extracellular matrix (ECM) remodeling. In the present study, we used a tissue-engineered, two-layers (epithelium and stroma) human cornea as a biomaterial to study both the cellular and molecular mechanisms of wound healing. Gene profiling on microarrays revealed important alterations in the pattern of genes expressed by tissue-engineered corneas in response to wound healing. Expression of many MMPs-encoding genes was shown by microarray and qPCR analyses to increase in the migrating epithelium of wounded corneas. Many of these enzymes were converted into their enzymatically active form as wound closure proceeded. In addition, expression of MMPs by human corneal epithelial cells (HCECs) was affected both by the stromal fibroblasts and the collagen-enriched ECM they produce. Most of all, results from mass spectrometry analyses provided evidence that a fully stratified epithelium is required for proper synthesis and organization of the ECM on which the epithelial cells adhere. In conclusion, and because of the many characteristics it shares with the native cornea, this human two layers corneal substitute may prove particularly useful to decipher the mechanistic details of corneal wound healing. Primary cultures of human corneal epithelial cells cultivated on BSA (number of replicates: 7), Collagen type I (number of replicates: 2), Collagen type IV (number of replicates: 2), Fibronectin (number of replicates: 2), Tenascin C (number of replicates: 2) and Laminin (number of replicates: 2) matrix. Central, internal and external ring of wounded Tissue-engineered human cornea.
Project description:Cartilage aging is a quintessential feature of knee osteoarthritis, and extracellular matrix (ECM) stiffening is a typical feature of cartilage aging. However, the mechanism of ECM stiffening to influence chondrocytes and downstream molecules is still poorly understood. Here, we mimicked the physiological and pathological stiffness of human cartilage by using polydimethylsiloxane-based substrates. We show that the epigenetic regulation of Parkin by histone deacetylase 3 (HDAC3) represents a new mechanosensitive mechanism by which the stiff matrix affects the physiology of chondrocytes. We found that ECM stiffening could accelerate the senescence of cultured chondrocytes in vitro, and also found that stiff ECM downregulated HDAC3, drove Parkin acetylation to activate excessive mitophagy, and accelerated chondrocyte senescence and osteoarthritis in mice. In contrast, intra-articular injection of adeno-associated virus expressing HDAC3 restored the young phenotype of aged chondrocytes stimulated by ECM stiffening and alleviated osteoarthritis in mice. Our findings indicate that changes in the mechanical properties of ECM initiate pathogenic mechanotransduction signals, promote the acetylation of Parkin and hyperactivate mitophagy, and damage the health of chondrocytes. These findings may provide new insights into how the mechanical properties of ECM regulate chondrocytes.
Project description:Corneal injuries remain a major cause of consultation in the ophthalmology clinics worldwide. Repair of corneal wounds is a complex mechanism that involves cell death, migration, proliferation, differentiation, and extracellular matrix (ECM) remodeling. In the present study, we used a tissue-engineered, two-layers (epithelium and stroma) human cornea as a biomaterial to study both the cellular and molecular mechanisms of wound healing. Gene profiling on microarrays revealed important alterations in the pattern of genes expressed by tissue-engineered corneas in response to wound healing. Expression of many MMPs-encoding genes was shown by microarray and qPCR analyses to increase in the migrating epithelium of wounded corneas. Many of these enzymes were converted into their enzymatically active form as wound closure proceeded. In addition, expression of MMPs by human corneal epithelial cells (HCECs) was affected both by the stromal fibroblasts and the collagen-enriched ECM they produce. Most of all, results from mass spectrometry analyses provided evidence that a fully stratified epithelium is required for proper synthesis and organization of the ECM on which the epithelial cells adhere. In conclusion, and because of the many characteristics it shares with the native cornea, this human two layers corneal substitute may prove particularly useful to decipher the mechanistic details of corneal wound healing.
Project description:Matrix metalloproteinases (MMPs) collectively degrade all extracellular matrix (ECM) proteins. MMP-9 has the strongest link to development of cardiac dysfunction. Aging is associated with increased MMP-9 expression in the left ventricle (LV) and reduced cardiac function. We investigated the effect of MMP-9 deletion on the cardiac ECM in aged mice. Based on label-free mass spectrometry analyses, MMP-9 dependent age-related changes were found in the mouse cardiac ECM proteome, suggesting MMP-9 as a possible therapeutic target for the aging patient