Extracellular Matrix Degradation Research Articles

RNF125, transcriptionally regulated by NFATC2, alleviates osteoarthritis via inhibiting the Wnt/β-catenin signaling pathway through degrading TRIM14

Osteoarthritis (OA) is a chronic joint disease characterized by the progressive degradation of articular cartilage. In this study, as determined by histological staining, the cartilage surface of the OA rats was damaged, defective and broken, and chondrocytes and proteoglycan were reduced. While moderate physical exercise showed protective effects on the cartilage. Besides, RNA-seq was performed to select a target protein and RNF125 (an E3 ubiquitin ligase) was decreased in the cartilage tissues of OA rats and increased after physiological exercise. However, the precise role of RNF125 in OA is still unknown. This work aimed to investigate the involvement and underlying mechanism of RNF125 in OA pathogenesis. Our results defined that adenovirus-mediated overexpression of RNF125 inhibited the degradation of extracellular matrix of chondrocytes induced by IL-1β, as revealed by increased chondrocyte viability, upregulated COL2A1 and ACAN levels, and downregulated MMP1, MMP13 and ADAMTS5 levels, which was abrogated by NR4A2 knockdown. In vivo, RNF125 relieved OA, manifested as reduced cartilage injury and increased chondrocytes. Mechanically, NFATC2 bound to the RNF125 promoter and directly regulated RNF125 transcription, as illustrated by luciferase reporter, Ch-IP and DNA pull-down assays. Furthermore, RNF125 overexpression inhibited the nuclear translocation of β-catenin, thus suppressing activation of the Wnt/β-catenin signaling pathway. Also, RNF125 as E3 ubiquitin ligase led to the ubiquitination and degradation of TRIM14 protein, and TRIM14 overexpression efficiently reversed the effects of RNF125 overexpression on OA progression. Totally, this study provides new insights into OA pathogenesis regulated by RNF125. RNF125 may be a novel biomarker for OA therapy.

Role of Metabolomics in Pathogenesis and Prompt Diagnosis of Gastric Cancer Metastasis-A Systematic Review.

Gastric cancer is the fourth most frequently diagnosed form of cancer and the third leading cause of cancer-related mortality worldwide. The aim of this review is to identify individual metabolic biomarkers and their association with accurate diagnostic values, which can predict gastric cancer metastasis. After searching the keywords, 83 articles were found over a period of 13 years. One was eliminated because it was not written in English, and two were published outside the selected period. Seven scientific papers were qualified for this investigation after eliminating duplicates, non-related articles, systematic reviews, and restricted access studies. New metabolic biomarkers with predictive value for gastric cancer metastasis and for elucidating metabolic pathways of the metastatic process have been found. The pathogenic processes can be outlined as follows: pro-oxidant capacity, T-cell inactivation, cell cycle arrest, energy production and mitochondrial enzyme impairment, cell viability and pro-apoptotic effect, enhanced degradation of collagen extracellular matrix, migration, invasion, structural protein synthesis, and tumoral angiogenesis. Metabolic biomarkers have been recognized as independent risk factors in the molecular process of gastric cancer metastasis, with good diagnostic and prognostic value.

Naringenin attenuates inflammation and apoptosis of osteoarthritic chondrocytes via the TLR4/TRAF6/NF-κB pathway.

Naringenin is a flavonoid extracted from the seed coat of Anacardiaceae plants. Increasing evidence indicates that it has several properties of biological significance, such as anti-infection, sterilization, anti-allergy, antioxidant free radical, and anti-tumor. However, its effect on osteoarthritis has not been elucidated properly. In this study, the treatment of primary chondrocytes with interleukin (IL)-1β was found to increase the secretions of IL-6, tumor necrosis factor (TNF)-α, and cyclooxygenase-2 (COX-2). Further, the mRNA expression of matrix metalloproteinase ((MMP)3, MMP9, and MMP13), the protein expression of Recombinant A Disintegrin And Metalloproteinase With Thrombospondin 5 (ADAMTS5), and cell apoptosis increased; the protein expression of Collagen II decreased. The injury of primary chondrocytes induced by IL-1β was reversed under the intervention of naringenin; this reversal was dose-dependent. The mechanistic study showed that naringenin inhibited the toll-like receptor 4 (TLR4)/TNF receptor-associated factor 6 (TRAF6)/NF-κB pathway in IL-1β-stimulated primary cells, and LPS, a TLR4 activator, reversed this inhibitory effect. In addition, a mouse model of osteoarthritis was established and treated with naringenin. The results revealed that naringenin alleviated the pathological symptoms of osteoarthritis in mice, reduced the expression of TLR4 and TRAF6, and the phosphorylation of NF-κB in knee cartilage tissue. It also inhibited the secretion of inflammatory factors, reduced extracellular matrix degradation, and decreased the protein expression of cleaved caspase3. In conclusion, the findings of this study suggest that naringenin may be a potential option for the treatment of osteoarthritis.

Abstract 18742: Matrilysin (MMP7) as a Robust Predictor of Hypertension Incidence and Complications: Findings From a Proteomic Analysis in the Atherosclerosis Risk in Communities (ARIC) Study

Introduction: Proteomic techniques can be applied for the discovery of common pathways underlying both incident hypertension and hypertension-related cardiovascular outcomes. Research Questions: To identify and validate proteins associated with incident hypertension and to examine the association of these validated proteins with hypertension-related cardiovascular events. Methods: We quantified the association of 4,955 plasma proteins (measured by SomaScan® Version 4 Assay) with incident hypertension (defined as systolic blood pressure (BP) ≥140, diastolic BP ≥ 90 mmHg, or hypertension medication use) in participants free of hypertension at ARIC visit 3 (1993-95) using Cox regression models adjusted for demographics, clinical characteristics and baseline BP. Significant associations were validated using proteomic measurements at ARIC visit 2 (1990-92). We then examined the association of validated proteins with incident coronary heart disease (CHD), stroke, and heart failure (HF) among participants with hypertension at visit 3 using Cox regression models additionally adjusted for hypertension duration and treatment. Results: There were 5,080 participants in the discovery cohort (mean age 59y, 13% Black, 54% women, median follow up 11 y) and 6,810 in the validation cohort (median follow up 3.1y). Four proteins were significantly associated with incident hypertension in the discovery cohort. One protein, Matrilysin (MMP7), remained significantly associated in the validation cohort (HR 1.22 [1.11-1.34]) (Figure1A). MMP7 was also significantly associated with all hypertension-related complications (Figure 1B-D). Conclusions: MMP7, a protein involved in extracellular matrix degradation, was robustly associated with incident hypertension and cardiovascular events. Future research examining the pathophysiologic mechanism of MMP7 could potentially yield drug targets for the prevention and treatment of hypertension.

Fucoxanthin ameliorates endoplasmic reticulum stress and inhibits apoptosis and alleviates intervertebral disc degeneration in rats by upregulating Sirt1.

Endoplasmic reticulum stress (ERS) and apoptosis of nucleus pulposus (NP) cells are considered to be the main pathological factors of intervertebral disc degeneration (IDD). Fucoxanthin (FX), a marine carotenoid extracted from microalgae, has antioxidant, anti-inflammatory, and anticancer properties. The aim of this study was to investigate the effect of FX on NP cells induced by oxidative stress and its molecular mechanism. Primary NP cells of the lumbar vertebrae of rats were extracted and tested in vitro. qRT-PCR, western blot, immunofluorescence, and TUNEL staining were used to detect apoptosis, ERS, extracellular matrix (ECM), and Sirt1-related pathways. In vivo experiments, the recovery of IDD rats was determined by X-ray, hematoxylin and eosin, Safranin-O/Fast Green, Alcian staining, and immunohistochemistry. Our study showed that oxidative stress induced ERS, apoptosis, and ECM degradation in NP cells. After the use of FX, the expression of Sirt1 was up-regulated, the activation of PERK-eIF2α-ATF4-CHOP was decreased, and apoptosis and ECM degradation were decreased. At the same time, FX improved the degree of disc degeneration in rats in vivo. Our study demonstrates the effect of FX on improving IDD in vivo and in vitro, suggesting that FX may be a potential drug for the treatment of IDD.

Centrosome amplification promotes cell invasion via cell-cell contact disruption and Rap-1 activation.

Centrosome amplification (CA) is a prominent feature of human cancers linked to tumourigenesis in vivo. Here, we report mechanistic contributions of CA induction alone to tumour architecture and extracellular matrix (ECM) remodelling. CA induction in non-tumourigenic breast cells MCF10A causes cell migration and invasion, with underlying disruption of epithelial cell-cell junction integrity and dysregulation of expression and subcellular localisation of cell junction proteins. CA also elevates expression of integrin β-3, binding partner fibronectin-1, matrix metalloprotease enzymes promoting cell-ECM attachment, ECM degradation, and a migratory and invasive cell phenotype. Using a Chicken Embryo xenograft model for in vivo validation, we show that +CA MCF10A cells invade into the chick mesodermal layer, with inflammatory cell infiltration and marked focal reactions between chorioallantoic membrane and cell graft. We also demonstrate a key role of small GTPase Rap-1 signalling through inhibition using GGTI-298, which blocked various CA-induced effects. These insights reveal that in normal cells, CA induction alone (without additional pro-tumorigenic alterations) is sufficient to confer early pro-tumourigenic changes within days, acting through Rap-1-dependent signalling to alter cell-cell contacts and ECM disruption.

β-elemene Suppresses Migration of Esophageal Squamous Cell Carcinoma by Modulating Expression of MMP9 through the PI3K/Akt/NF-κB Pathway.

β-elemene is a plant-derived drug with broad-spectrum anticancer activity. Studies have found that β-elemene can inhibit tumor cell proliferation, induce tumor cell apoptosis, and resist tumor cell migration and invasion. Esophageal cancer is a common digestive tract malignant tumor. Progress has been made in the treatment of esophageal cancer, including the use of β-elemene, but the mechanism of anti-migration is unclear. PI3K/Akt/NF- κB/MMP9 signaling pathway is involved in the regulation of tumor cell proliferation, migration, extracellular matrix(ECM), and basement membrane(BM) degradation. This study aims to investigate the effect of β-elemene on the migration of esophageal squamous cell carcinoma (ESCC) and its related mechanisms by bioinformatics, network pharmacology, and molecular docking methods. In this study, the differentially expressed genes (DEGs) of ESCC were screened through GeneCards and BATMAN-TCM databases combined with the Gene Expression Omnibus (GEO) database (GSE17351). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to identify the functions and related pathways of the genes. The protein-protein interaction (PPI) network of these DEGs was constructed with the STRING database. Five hub genes were screened by CytoHubba plug-in Cytoscape according to the principle of degree value and the expressions of which were validated by the UALCAN database from the Cancer Genome Atlas (TCGA). The hub gene with the strongest binding energy was identified by molecular docking. A wound healing assay was subjected to assess the migration ability. RT-PCR was used to detect the content of migration-related mRNA. Western blotting was performed to examine the expression rates of Akt, NF-κB, and MMP9 in ESCC tissues by β-elemene and SC79. 71 target genes were obtained which were mainly involved in biological processes such as epidermal development and extracellular matrix decomposition. In addition, critical pathways, including PI3K/AKT signaling pathway and focal adhesion, were verified to be subject to β-elemene regulation. It exhibited marked binding affinity between β-elemene and MMP9 with an excellent docking score of -6.56 kcal/mol. The expression levels of Akt, NF-κB, and MMP9 in ESCC tissues were significantly upregulated compared to normal tissues. Western blot detection demonstrated that β-elemene specifically reduced the phosphorylation level of Akt, and its downstream target molecule NF-κB, thus resulting in reduced levels of their target proteins, including MMP9 in ESCC. A wound healing assay showed β-elemene inhibited the migration of ESCC cells. RT-PCR results found that the mRNA expression of Akt, NF-κB, and MMP9 in the β-elemene group was significantly lower than that in the control group. However, the application of SC79 partially reversed the effect of β-elemene. In summary, our study suggests that the anti-tumor migration effect of β-elemene on ESCC is associated with the inhibition of PI3K/Akt/NF-κB/MMP9 signalling pathway, and it provides a theoretical reference for further rational clinical application.

The TFPI2–PPARγ axis induces M2 polarization and inhibits fibroblast activation to promote recovery from post-myocardial infarction in diabetic mice

BackgroundDiabetes mellitus is one of the causes of poor ventricular remodelling and poor cardiac recovery after myocardial infarction (MI). We previously reported that tissue factor pathway inhibitor-2 (TFPI2) was downregulated in response to hyperglycaemia and that it played a pivotal role in extracellular matrix (ECM) degradation and cell migration. Nonetheless, the function and mechanism of TFPI2 in post-MI remodelling under diabetic conditions remain unclear. Therefore, in the present study, we investigated the role of TFPI2 in post-MI effects in a diabetic mouse model.ResultsTFPI2 expression was markedly decreased in the infarcted myocardium of diabetic MI mice compared with that in non-diabetic mice. TFPI2 knockdown in the MI mouse model promoted fibroblast activation and migration as well as matrix metalloproteinase (MMP) expression, leading to disproportionate fibrosis remodelling and poor cardiac recovery. TFPI2 silencing promoted pro-inflammatory M1 macrophage polarization, which is consistent with the results of TFPI2 downregulation and M1 polarization under diabetic conditions. In contrast, TFPI2 overexpression in diabetic MI mice protected against adverse cardiac remodelling and functional deterioration. TFPI2 overexpression also inhibited MMP2 and MMP9 expression and attenuated fibroblast activation and migration, as well as excessive collagen production, in the infarcted myocardium of diabetic mice. TFPI2 promoted an earlier phenotype transition of pro-inflammatory M1 macrophages to reparative M2 macrophages via activation of peroxisome proliferator-activated receptor gamma.ConclusionsThis study highlights TFPI2 as a promising therapeutic target for early resolution of post-MI inflammation and disproportionate ECM remodelling under diabetic conditions.

The Role of Extracellular Matrix and Inflammation in the Stratification of Bleeding and Thrombotic Risk of Atrial Fibrillation on Oral Anticoagulant Therapy: Insights from Strat-Af Study.

In anticoagulated atrial fibrillation (AF) patients, the validity of models recommended for the stratification of the risk ratio between benefits and hemorrhage risk is limited. We hypothesize that both circulating and neuroimaging-based markers might improve the prediction of bleeding and thrombotic risk in anticoagulated AF patients. The Strat-AF study is an observational, prospective, single-center study enrolling 170 patients with AF; recruited patients are evaluated by means of a comprehensive protocol, with clinical, cerebral magnetic resonance imaging and circulating biomarkers assessment. The main outcome is the evaluation of cerebral microangiopathy related to the levels of circulating biomarkers of inflammation and extracellular matrix (ECM) remodeling. At multivariate logistic regression analysis adjusted for age, sex, CHA2DS2-VASc, HAS-BLED and type of anticoagulant, matrix metalloproteinases (MMP)-2 levels were significantly and positively associated with the presence of cerebral microbleeds (CMBs). A significant association between MMP-2, tissue inhibitor of metalloproteinases (TIMP)-1,-2,-4 levels and white matter hyperintensity was also found. Concerning the small vessel disease (SVD) score, MMP-2 and TIMP-1,-2 levels were associated with the presence of two and three or more signs of SVD, whereas TIMP-4 levels were associated with the presence of three signs of SVD with respect to patients with no instrumental signs of SVD. As regarding the presence of enlarged perivascular spaces (EPVS), a significant association was found for high levels of interleukin (IL)-8 and TIMP 1-2-3. These results demonstrate that patients with AF have evidence of impaired ECM degradation, which is an independent risk factor for thrombotic complications of AF patients on oral anticoagulant therapy. The incorporation of these markers in the prognostic schemes might improve their clinical capability in predicting stroke risk and thrombotic complications.

Xanthohumol alleviates palmitate-induced inflammation and prevents osteoarthritis progression by attenuating mitochondria dysfunction/NLRP3 inflammasome axis

Osteoarthritis (OA) is a prevalent chronic degenerative joint disease worldwide. Obesity has been linked to OA, and increased free fatty acid levels (e.g., palmitate) contribute to inflammatory responses and cartilage degradation. Xanthohumol (Xn), a bioactive prenylated chalcone, was shown to exhibit antioxidative, anti-inflammatory, and anti-obesity capacities in multiple diseases. However, a clear description of the preventive effects of Xn on obesity-associated OA is unavailable. This study aimed to assess the chondroprotective function of Xn on obesity-related OA. The in vitro levels of inflammatory and ECM matrix markers in human chondrocytes were assessed after the chondrocytes were treated with PA and Xn. Additionally, in vivo cartilage degeneration was assessed following oral administration of HFD and Xn. This study found that Xn treatment completely reduces the inflammation and extracellular matrix degradation caused by PA. The proposed mechanism involves AMPK signaling pathway activation by Xn, which increases mitochondrial biogenesis, attenuates mitochondrial dysfunction, and inhibits NLRP3 inflammasome and the NF-κB signaling pathway induced by PA. In summary, this study highlights that Xn could decrease inflammation reactions and the degradation of the cartilage matrix induced by PA by inhibiting the NLRP3 inflammasome and attenuating mitochondria dysfunction in human chondrocytes.

The cellular responses of corneal fibroblasts to cyclic stretching loads

Mechanical signaling plays a crucial role in maintaining extracellular matrix (ECM) homeostasis in various structures. In this study, we investigated the responses of corneal fibroblasts to cyclic stretching loads using an in vitro cell culture system. Bovine corneal fibroblasts were cultured and subjected to equibiaxial cyclic strain of 15% for 72 h at a frequency of 0.25 Hz, with bovine skin fibroblasts used as a comparison. We explored various cellular behaviors, including morphological changes, cell proliferation, and metabolism in response to mechanical stretching loads. The expression of genes, protein secretion, and enzymatic activity for several major metalloproteinases was also determined through Q-PCR, Western blot, and gel zymography. Additionally, we investigated the involvement of mitogen-activated protein kinases (MAPKs) signaling pathways in the corneal fibroblasts when subjected to mechanical stimuli. Our findings revealed that, compared to skin fibroblasts, corneal fibroblasts were reluctant to morphological changes in response to a prolonged (72 h) and high-amplitude (15% of strain) cyclic stretching load. However, cyclic stretching loads stimulated the upregulation of MMP-2 expression in corneal fibroblasts via the MAPK signaling pathways involving extracellular signal-regulated kinase and p38. Together with a lack of upregulation in type I collagen expression, our results indicate the induction of the ECM degradation process in corneal fibroblasts in response to cyclic stretching. These findings emphasize the mechanoresponsive nature of corneal fibroblasts and shed light on the potential impact of intense mechanical stress on the cornea in both normal and pathological conditions such as keratoconus, providing valuable insights for understanding corneal mechanobiology.

The Role of Cysteine Protease Cathepsins B, H, C, and X/Z in Neurodegenerative Diseases and Cancer.

Papain-like cysteine proteases are composed of 11 human cysteine cathepsins, originally located in the lysosomes. They exhibit broad specificity and act as endopeptidases and/or exopeptidases. Among them, only cathepsins B, H, C, and X/Z exhibit exopeptidase activity. Recently, cysteine cathepsins have been found to be present outside the lysosomes and often participate in various pathological processes. Hence, they have been considered key signalling molecules. Their potentially hazardous proteolytic activities are tightly regulated. This review aims to discuss recent advances in understanding the structural aspects of these four cathepsins, mechanisms of their zymogen activation, regulation of their activities, and functional aspects of these enzymes in neurodegeneration and cancer. Neurodegenerative effects have been evaluated, particularly in Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, multiple sclerosis, and neuropsychiatric disorders. Cysteine cathepsins also participate in tumour progression and metastasis through the overexpression and secretion of proteases, which trigger extracellular matrix degradation. To our knowledge, this is the first review to provide an in-depth analysis regarding the roles of cysteine cathepsins B, H, C, and X in neurodegenerative diseases and cancer. Further advances in understanding the functions of cysteine cathepsins in these conditions will result in the development of novel, targeted therapeutic strategies.

Salvianolic acid A contributes to cartilage endplate cell restoration by regulating miR-940 and miR-576-5p

To investigate whether Salvianolic acid A (SAA) can restore cartilage endplate cell degeneration of intervertebral discs and to identify the mechanism via regulation of micro-RNA. Cartilage endplate cells were isolated from lumbar intervertebral disc surgical samples and were treated with serum containing a series of concentrations of SAA (2, 5, and 10 ?M) for 24, 48, and 72 h to identify a proper dose and treatment time of SAA. The effect SAA on interlenkin-1β (IL-1β)-induced extracellular matrix degradation of cartilage endplate cells were analyzed by Alcian blue staining and assessment of the expression levels of ADAMTS-5, MMP3 and Col2a1. Further, the potential target miRNAs were preliminarily screened by micro-RNA sequencing combining qRT-PCR and Western blot, and then, the miRNAs mimics and inhibitors were used to verify the regulatory effect of SAA on potential target miRNAs. The 10 μM SAA treatment for 48 h significantly enhanced the viability of cartilage endplate cells, and increased Col2a1 expression and glycosaminoglycan accumulation that were repressed by IL-1β, and reduced the effect of IL-1β on ADAMTS-5, and MMP3. Screening analysis based on micro-RNA sequencing and Venny analysis identified the downstream micro-RNAs, including miR-940 and miR-576-5p. Then, the miR-940-mimic or miR-576-5p-mimic were transfected into CEPCs. Compared with the SAA group, the expression of ADAMTS-5 and MMP3 increased significantly and the expression of COL2A1 obviously decreased after overexpression of miR-940 or miR-576-5p in CEPCs. Salvianolic acid A attenuated the IL-1β-induced extracellular matrix degradation of cartilage endplate cells by targeting regulate the miR-940 and the miR-576-5p.

Ultrahigh Enzyme Loading Metal-Organic Frameworks for Deep Tissue Pancreatic Cancer Photoimmunotherapy.

Protein drugs hold promise in treating multiple complex diseases, including cancer. The priority of protein drug application is precise delivery of substantial bioactive protein into tumor site. Metal-organic-framework (MOF) is widely considered as a promising carrier to encapsulate protein drug owing to the noncovalent interaction between carrier and protein. However, limited loading efficiency and potential toxicity of metal ion in MOF restrict its application in clinical research. Herein, a tumor targeted collagenase-encapsulating MOF via protein-metal ion-organic ligand coordination (PMOCol ) for refining deep tissue pancreatic cancer photoimmunotherapy is developed. By an expedient method in which the ratio of metal ion, histidine residues of protein and ligand is precisely controlled, PMOCol is constructed with ultrahigh encapsulation efficiency (80.3 wt%) and can release collagenase with high enzymatic activity for tumor extracellular matrix (ECM) regulation after reaching tumor microenvironment (TME). Moreover, PMOcol exhibits intensively poorer toxicity than the zeolitic imidazolate framework-8 biomineralized protein. After treatment, the pancreatic tumor with abundant ECM shows enhanced immunocyte infiltration owing to extracellular matrix degradation that improves suppressive TME. By integrating hyperthermia agent with strong near-infrared absorption (1064 nm), PMOCol can induce acute immunogenicity to host immunity activation and systemic immune memory production to prevent tumor development and recurrence.

An Inverse Modeling Approach to Estimate Three-Dimensional Aortic Valve Interstitial Cell Stress Fiber Force Levels.

Within the aortic valve (AV) leaflet exists a population of interstitial cells (AVICs) that maintain the constituent tissues by extracellular matrix (ECM) secretion, degradation, and remodeling. AVICs can transition from a quiescent, fibroblast-like phenotype to an activated, myofibroblast phenotype in response to growth or disease. AVIC dysfunction has been implicated in AV disease processes, yet our understanding of AVIC function remains quite limited. A major characteristic of the AVIC phenotype is its contractile state, driven by contractile forces generated by the underlying stress fibers (SF). However, direct assessment of the AVIC SF contractile state and structure within physiologically mimicking three-dimensional environments remains technically challenging, as the size of single SFs are below the resolution of light microscopy. Therefore, in the present study, we developed a three-dimensional (3D) computational approach of AVICs embedded in 3D hydrogels to estimate their SF local orientations and contractile forces. One challenge with this approach is that AVICs will remodel the hydrogel, so that the gel moduli will vary spatially. We thus utilized our previous approach (Khang et al. 2023, "Estimation of Aortic Valve Interstitial Cell-Induced 3D Remodeling of Poly (Ethylene Glycol) Hydrogel Environments Using an Inverse Finite Element Approach," Acta Biomater., 160, pp. 123-133) to define local hydrogel mechanical properties. The AVIC SF model incorporated known cytosol and nucleus mechanical behaviors, with the cell membrane assumed to be perfectly bonded to the surrounding hydrogel. The AVIC SFs were first modeled as locally unidirectional hyperelastic fibers with a contractile force component. An adjoint-based inverse modeling approach was developed to estimate local SF orientation and contractile force. Substantial heterogeneity in SF force and orientations were observed, with the greatest levels of SF alignment and contractile forces occurring in AVIC protrusions. The addition of a dispersed SF orientation to the modeling approach did not substantially alter these findings. To the best of our knowledge, we report the first fully 3D computational contractile cell models which can predict locally varying stress fiber orientation and contractile force levels.

Pathogenetic Mechanisms of the Relationship Between Osteoarthritis and Intestinal Dysbiosis

The potential association between dysbiosis of the gut microbiota and osteoarthritis is confirming by a growing number of studies. Given the social significance, the high prevalence of osteoarthritis, and evidences that quantitative and qualitative modification of the gut microbiota affects its progression, it seems important to clarify the underlying mechanisms of this association. Osteoarthritis is a multifactorial joint disease, which is based primarily on the progressive degeneration of articular cartilage. Impaired metabolic activity of chondrocytes, consisting in an imbalance in the extracellular matrix synthesis and degradation processes, causes the persistent release of molecular patterns associated with damage. This leads to the activation of a wide range of innate immune cells receptors and is the basis for the development of an inflammatory reaction in the joint. The involvement of macrophages in the synovial membrane and their activation leads to the production of pro-inflammatory cytokines, leading to the development of chronic low-grade inflammation in the joint, supporting the synthesis of catabolic enzymes by chondrocytes and escalating the cartilage degeneration. Microbial dysbiosis, defined as an adverse modification in the diversity, structure, or metabolic activity of the gut microbiota, is a hidden risk factor, accompanied by metabolic endotoxemia and, consequently, by increased production of pro-inflammatory cytokines, that support the systematic low-grade inflammation and pathophysiological mechanisms of osteoarthritis. It has been shown that dysbiosis of the gut microbiota intestinal takes part in the formation of other osteoarthritis risk factors for, for example, obesity and metabolic disorders. The identification of important interrelated pathophysiological mechanisms of these pathologies will contribute to the development of new pathogenetic treatment methods with their subsequent active introduction into clinical practice.

High expression of RAB7A is associated with poor prognosis of gastric cancer by promoting tumor invasion

To explore the expression level of Ras-related protein 7A (RAB7A) in gastric cancer and its prognostic implications. Based on data from public databases and a cohort of 104 patients undergoing radical gastrectomy for gastric cancer in our hospital, we analyzed RAB7A expression level in gastric cancer and adjacent tissues and its association with clinicopathological parameters and prognosis of the patients. Bioinformatic analysis was performed to predict the pathways of RAB7A to affect gastric cancer invasion. In gastric cancer MGC803 cells with lentivirus-mediated interference or overexpression of RAB7A, the changes in extracellular matrix (ECM) degradation and cell migration and invasion were analyzed using immunoblotting, wound healing assay and Transwell experiments. The data from public cancer databases and clinical samples showed a significantly higher expression of RAB7A in gastric cancer tissues than in normal or adjacent tissues (P<0.01) with a close correlation with a poorer patient survival (P<0.01) and a positive correlation with serum carcinoembryonic antigen and carbohydrate antigen 19-9 levels (P<0.001). Univariate and multivariate Cox regression analyses suggested that a high RAB7A expression was an independent risk factor affecting the 5-year survival rate of gastric cancer patients (HR: 2.882; 95% CI: 1.459-5.693). ROC curve analysis showed that at the cut-off value of 2.625, RAB7A expression level had a sensitivity of 84.62% and a specificity of 71.15% for predicting postoperative 5-year mortality of the patients. Bioinformatic analysis suggested that RAB7A was involved in ECM degradation and activation of PI3K/AKT signaling in gastric cancer. MGC803 cells with RAB7A overexpression showed activation of the PI3K/AKT signaling pathway (P<0.01) with enhanced expressions of MMP-2 and MMP-9 (P<0.01) and cell migration and invasion capacities (P<0.01). RAB7A is highly expressed in gastric cancer tissues and affects the patients' prognosis possibly by activating the PI3K/AKT signaling pathway and enhancing ECM degradation to promote tumor invasion.

PLXNC1 interference alleviates the inflammatory injury, apoptosis and extracellular matrix degradation of IL-1β-exposed chondrocytes via suppressing GRP78 expression

BackgroundOsteoarthritis (OA) is a frequently encountered debilitating joint disorder. Whether plexin C1 (PLXNC1) is implicated in OA is far from being investigated despite its well-documented pro-inflammatory property in human diseases. The goal of this study is to expound the specific role of PLXNC1 in OA and elaborate the probable action mechanism.MethodsFirstly, PLXNC1 expression in the cartilage tissues of patients with OA was examined with GEO database. In interleukin-1beta (IL-1β)-induced OA cell model, RT-qPCR and western blotting tested the expression of PLXNC1, glucose-regulating protein 78 (GRP78) and extracellular matrix (ECM) degradation-related factors. Cell viability and inflammation were respectively judged by CCK-8 assay and RT-qPCR. TUNEL and western blotting estimated cell apoptosis. The potential binding between PLXNC1 and GRP78 was corroborated by Co-IP assay. Western blotting also tested the expression of endoplasmic reticulum stress (ERS)-associated proteins.ResultsAs it turned out, PLXNC1 expression was elevated in the cartilage tissues of patients with OA and IL-1β-treated chondrocytes. When PLXNC1 was depleted, the viability injury, inflammation, apoptosis and ECM degradation of chondrocytes exposed to IL-1β were obstructed. Besides, GRP78 bond to PLXNC1 in IL-1β-treated chondrocytes. The ascending GRP78 expression in the chondrocytes exposed to IL-1β was depleted after PLXNC1 was silenced. Meanwhile, the impacts of PLXNC1 deficiency on the viability, inflammatory response, apoptosis, ECM degradation as well as ERS in IL-1β-exposed chondrocytes were abolished by GRP78 up-regulation.ConclusionIn summary, PLXNC1 silencing might interact with and down-regulate GRP78 to mitigate the apoptosis, inflammation, and ECM degradation of IL-1β-insulted chondrocytes in OA.

Inhibition of LncRNA SNHG14 protects chondrocyte from injury in osteoarthritis via sponging miR-137

Long-chain noncoding small nucleolar RNA host gene 14 (LncRNA SNHG14) is highly expressed in various diseases and promotes diseases progression, but the role and mechanism of LncRNA SNHG14 on targeting miR-137 in promoting osteoarthritis (OA) chondrocyte injury remains unclear. To measure the expression of the LncRNAs SNHG14 and miR-137, cell survival, inflammatory response, chondrocyte apoptosis, and extracellular matrix (ECM) levels, we subjected human chondrocytes to a variety of lipopolysaccharide (LPS) concentrations. To measure the luciferase activity of SNHG14-WT and SNHG14-MUT transfected with miR-137 mimic or miR-NC mimic, luciferase reporter genes were utilized. The results showed that chondrocyte viability was significantly inhibited with LPS treatment and chondrocyte inflammatory response, apoptosis and extracellular matrix degradation were significantly increased. However, the above results were significantly reversed after LncRNA SNHG14 inhibition. The luciferase activity bound to miR-137 was decreased in SNHG14-WT group, but there was no change in SNHG14-mut group, which indicated that LncRNA SNHG14 inhibited miR-137 expression as a miRNA sponge. In conclusion, inhibition of LncRNA SNHG14 attenuates chondrocyte inflammatory response, apoptosis and extracellular matrix degradation by targeting miR-137 in LPS induced chondrocytes.

A novel view to varicose veins pathogenesis: Proteomic profiling suggests a pivotal role of extracellular matrix degradation.

Although morphological and anatomical studies indicate that venous wall weakening and subendothelial fibrosis characterize varicose veins (VV), the pathogenesis of VV remains poorly understood. The aim of this study is to obtain protein expression profiles in patients with VV and thereby get a step closer to understanding the pathogenesis of VV. Specimens were obtained from total of 10 patients, that is, from 5 patients undergoing VV surgical stripping and from 5 non-VV patients undergoing bypass surgery. Specimens were collected from the same layers of venous wall. Proteins were extracted from each specimen and analyzed by ion mobility spectrometry (IMS-MS). In total, 1387 were identified and 486 proteins were identified in all samples. From these, 15 proteins were differentially expressed between VV and non-VV samples (p < .05) and 12 of these showed a fold change >1.5. Interestingly, among the differentially expressed proteins, only two proteins were significantly increased in the VV tissue, that is, GAPDH (p = .028, fold change 2.74), where several proteins involved in maintaining the homeostasis in the extracellular matrix, that is, the CXXC zinc finger protein 5 (CXXC5) and nucleoporin (SEH1) were prominently downregulated (p = .049, fold change 37.8, and p = .040, fold change 3.46). The downregulation in protein expression of CXXC5 and SEH1 as well as upregulation of GAPDH were validated by Western blotting. The identified differentially expressed proteins suggest an altered profile of the connective tissue proteins as well as an increased proteolytic enzyme activity which both may be central in the pathophysiology of varicose veins.