SKP2-mediated ubiquitination and degradation of KLF11 promotes osteoarthritis via modulation of JMJD3/NOTCH1 pathway

Osteoarthritis (OA) is the main cause of cartilage damage and disability. This study explored the biological function of S-phase kinase-associated protein 2 (SKP2) and Kruppel-like factor 11 (KLF11) in OA progression and its underlying mechanisms. C28/I2 chondrocytes were stimulated with IL-1β to mimic OA in vitro. We found that SKP2, Jumonji domain-containing protein D3 (JMJD3), and Notch receptor 1 (NOTCH1) were upregulated, while KLF11 was downregulated in IL-1β-stimulated chondrocytes. SKP2/JMJD3 silencing or KLF11 overexpression repressed apoptosis and extracellular matrix (ECM) degradation in chondrocytes. Mechanistically, SKP2 triggered the ubiquitination and degradation of KLF11 to transcriptionally activate JMJD3, which resulted in activation of NOTCH1 through inhibiting H3K27me3. What's more, the in vivo study found that KLF11 overexpression delayed OA development in rats via restraining apoptosis and maintaining the balance of ECM metabolism. Taken together, ubiquitination and degradation of KLF11 regulated by SKP2 contributed to OA progression by activation of JMJD3/NOTCH1 pathway. Our findings provide promising therapeutic targets for OA.

Sympathetic Neurotransmitter, VIP, Delays Intervertebral Disc Degeneration via FGF18/FGFR2-Mediated Activation of Akt Signaling Pathway

Neuromodulation-related intervertebral disc degeneration (IVDD) is a novel IVDD pattern and are proposed recently. However, the mechanistic basis of neuromodulation and intervertebral disc (IVD) homeostasis remains unclear. Here, this study aimed to investigate the expression of postganglionic sympathetic nerve fiber-derived vasoactive intestinal peptide (VIP) system in human IVD tissue, and to assess the role of VIP-related neuromodulation in IVDD. Patient samples and in vitro cell experiments showed that the expression of receptors for VIP is negatively correlated with the severity of IVDD, and the administration of exogenous VIP can ameliorate interleukin 1β-induced nucleus pulposus (NP) cell apoptosis and inflammation. Further mRNA-seq analysis revealed that fibroblast growth factor 18- (FGF18)-mediated activation of V-akt murine thymoma viral oncogene homolog signaling pathway is involved in the protective effects of VIP on inflammation-induced NP cell degeneration. Further analysis identified VIP via its receptor vasoactive intestinal peptide receptor 2 can directly result in decreased expression of miR-15a-5p, which targeted FGF18. Finally, in vivo mice lumbar IVDD model confirmed that focally exogenous administration of VIP can effectively ameliorated the progression of IVDD, as shown by the radiological and histological analysis. In conclusion, these results indicated that sympathetic neurotransmitter, VIP, delayed IVDD via FGF18/FGFR2-mediated activation of V-akt murine thymoma viral oncogene homolog signaling pathway, which will broaden the horizon concerning how the neuromodulation correlates with IVDD and shed new light on novel therapeutical alternatives to IVDD.

uPAR (PLAUR) Marks Two Intra-Tumoral Subtypes of Glioblastoma: Insights from Single-Cell RNA Sequencing

Urokinase plasminogen activator receptor (uPAR) encoded by the PLAUR gene is known as a clinical marker for cell invasiveness in glioblastoma multiforme (GBM). It is additionally implicated in various processes, including angiogenesis and inflammation within the tumor microenvironment. However, there has not been a comprehensive study that depicts the overall functions and molecular cooperators of PLAUR with respect to intra-tumoral subtypes of GBM. Using single-cell RNA sequencing data from 37 GBM patients, we identified PLAUR as a marker gene for two distinct subtypes in GBM. One subtype is featured by inflammatory activities and the other subtype is marked by ECM remodeling processes. Using the whole-transcriptome data from single cells, we are able to uncover the molecular cooperators of PLAUR for both subtypes without presuming biological pathways. Two protein networks comprise the molecular context of PLAUR, with each of the two subtypes characterized by a different dominant network. We concluded that targeting PLAUR directly influences the mechanisms represented by these two protein networks, regardless of the subtype of the targeted cell.

PDK4 inhibits osteoarthritis progression by activating the PPAR pathway

BACKGROUND

Osteoarthritis (OA) is a degenerative joint disease caused by the deterioration of cartilage. However, the underlying mechanisms of OA pathogenesis remain elusive.

METHODS

Hub genes were screened by bioinformatics analysis based on the GSE114007 and GSE169077 datasets. The Sprague-Dawley (SD) rat model of OA was constructed by intra-articular injection of a mixture of papain and L-cysteine. Hematoxylin-eosin (HE) staining was used to detect pathological changes in OA rat models. Inflammatory cytokine levels in serum were measured employing the enzyme-linked immunosorbent assay (ELISA). The reverse transcription quantitative PCR (RT-qPCR) was implemented to assess the hub gene expressions in OA rat models. The roles of PDK4 and the mechanism regulating the PPAR pathway were evaluated through western blot, cell counting kit-8 (CCK-8), ELISA, and flow cytometry assays in C28/I2 chondrocytes induced by IL-1β.

RESULTS

Six hub genes were identified, of which COL1A1, POSTN, FAP, and CDH11 expressions were elevated, while PDK4 and ANGPTL4 were reduced in OA. Overexpression of PDK4 inhibited apoptosis, inflammatory cytokine levels (TNF-α, IL-8, and IL-6), and extracellular matrix (ECM) degradation protein expressions (MMP-3, MMP-13, and ADAMTS-4) in IL-1β-induced chondrocytes. Further investigation revealed that PDK4 promoted the expression of PPAR signaling pathway-related proteins: PPARA, PPARD, and ACSL1. Additionally, GW9662, an inhibitor of the PPAR pathway, significantly counteracted the inhibitory effect of PDK4 overexpression on IL-1β-induced chondrocytes.

CONCLUSION

PDK4 inhibits OA development by activating the PPAR pathway, which provides new insights into the OA management.

FZD3 regulates the viability, apoptosis, and extracellular matrix degradation of vaginal wall fibroblasts in pelvic organ prolapse via the Wnt signaling pathway

The occurrence of pelvic organ prolapse (POP) seriously affects women's quality of life. However, the pathogenesis of POP remains unclear. We aimed to clarify the role of Frizzled class receptor 3 (FZD3) in POP. FZD3 expression in the vaginal wall tissues was detected using immunohistochemistry, real-time polymerase chain reaction, and western blot analysis. Then, vaginal wall fibroblasts (VWFs) were isolated from patients with POP and non-POP, and were identified. Cell viability and apoptosis were evaluated using Cell Counting Kit-8 and flow cytometry, respectively. Extracellular matrix (ECM) degradation was assessed by western blot analysis. The results illustrated that FZD3 was downregulated in POP. VWFs from POP had lower cell viability, ECM degradation, and higher apoptosis. Knockdown of FZD3 inhibited cell viability, ECM degradation, and promoted apoptosis of VWFs, whereas overexpression of FZD3 had opposite results. Moreover, IWP-4 (Wingless-type [Wnt] pathway inhibitor) reversed the role of FZD3 overexpression on biological behaviors. Taken together, FZD3 facilitates VWFs viability, ECM degradation, and inhibits apoptosis via the Wnt pathway in POP. The findings provide a potential target for the treatment of POP.

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

BACKGROUND

Osteoarthritis (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.

METHODS

Firstly, 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.

RESULTS

As 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.

CONCLUSION

In 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.

Lipid metabolism disorder promotes the development of intervertebral disc degeneration

Lipid metabolism is a complex process that maintains the normal physiological function of the human body. The disorder of lipid metabolism has been implicated in various human diseases, such as cardiovascular diseases and bone diseases. Intervertebral disc degeneration (IDD), an age-related degenerative disease in the musculoskeletal system, is characterized by high morbidity, high treatment cost, and chronic recurrence. Lipid metabolism disorder may promote the pathogenesis of IDD, and the potential mechanisms are complex. Leptin, resistin, nicotinamide phosphoribosyltransferase (NAMPT), fatty acids, and cholesterol may promote the pathogenesis of IDD, while lipocalin, adiponectin, and progranulin (PGRN) exhibit protective activity against IDD development. Lipid metabolism disorder contributes to extracellular matrix (ECM) degradation, cell apoptosis, and cartilage calcification in the intervertebral discs (IVDs) by activating inflammatory responses, endoplasmic reticulum (ER) stress, and oxidative stress and inhibiting autophagy. Several lines of agents have been developed to target lipid metabolism disorder. Inhibition of lipid metabolism disorder may be an effective strategy for the therapeutic management of IDD. However, an in-depth understanding of the molecular mechanism of lipid metabolism disorder in promoting IDD development is still needed.

Magnolia kobus Extract Suppresses Porphyromonas gingivalis LPS-Induced Proinflammatory Cytokine and MMP Expression in HGF-1 Cells and Regulates Osteoclastogenesis in RANKL-Stimulated RAW264.7 Cells

Clinical prevention is of utmost importance for the management of periodontal diseases. Periodontal disease starts with an inflammatory response in the gingival tissue, and results in alveolar bone destruction and subsequent tooth loss. This study aimed to confirm the anti-periodontitis effects of MKE. To confirm this, we studied its mechanism of action using qPCR and WB in LPS-treated HGF-1 cells and RANKL-induced osteoclasts. We found that MKE suppressed proinflammatory cytokine protein expression by inhibiting the TLR4/NF-κB pathway in LPS-PG-induced HGF-1 cells and blocking ECM degradation by regulating the expression of TIMPs and MMPs. We also confirmed that TRAP activity and multinucleated cell formation were reduced in RANKL-stimulated osteoclasts after exposure to MKE. These results were confirmed by inhibiting TRAF6/MAPK expression, which led to the suppression of NFATc1, CTSK, TRAP, and MMP expression at the gene and protein levels. Our results confirmed that MKE is a promising candidate for the management of periodontal disease based on its anti-inflammatory effects and inhibition of ECM degradation and osteoclastogenesis.

Metastatic phenotype and immunosuppressive tumour microenvironment in pancreatic ductal adenocarcinoma: Key role of the urokinase plasminogen activator (PLAU)

Background

Previous studies have revealed the role of dysregulated urokinase plasminogen activator (encoded by PLAU) expression and activity in several pathways associated with cancer progression. However, systematic investigation into the association of PLAU expression with factors that modulate PDAC (pancreatic ductal adenocarcinoma) progression is lacking, such as those affecting stromal (pancreatic stellate cell, PSC)-cancer cell interactions, tumour immunity, PDAC subtypes and clinical outcomes from potential PLAU inhibition.

Methods

This study used an integrated bioinformatics approach to identify prognostic markers correlated with PLAU expression using different transcriptomics, proteomics, and clinical data sets. We then determined the association of dysregulated PLAU and correlated signatures with oncogenic pathways, metastatic phenotypes, stroma, immunosuppressive tumour microenvironment (TME) and clinical outcome. Finally, using an in vivo orthotopic model of pancreatic cancer, we confirmed the predicted effect of inhibiting PLAU on tumour growth and metastasis.

Results

Our analyses revealed that PLAU upregulation is not only associated with numerous other prognostic markers but also associated with the activation of various oncogenic signalling pathways, aggressive phenotypes relevant to PDAC growth and metastasis, such as proliferation, epithelial-mesenchymal transition (EMT), stemness, hypoxia, extracellular cell matrix (ECM) degradation, upregulation of stromal signatures, and immune suppression in the tumour microenvironment (TME). Moreover, the upregulation of PLAU was directly connected with signalling pathways known to mediate PSC-cancer cell interactions. Furthermore, PLAU upregulation was associated with the aggressive basal/squamous phenotype of PDAC and significantly reduced overall survival, indicating that this subset of patients may benefit from therapeutic interventions to inhibit PLAU activity. Our studies with a clinically relevant orthotopic pancreatic model showed that even short-term PLAU inhibition is sufficient to significantly halt tumour growth and, importantly, eliminate visible metastasis.

Conclusion

Elevated PLAU correlates with increased aggressive phenotypes, stromal score, and immune suppression in PDAC. PLAU upregulation is also closely associated with the basal subtype type of PDAC; patients with this subtype are at high risk of mortality from the disease and may benefit from therapeutic targeting of PLAU.

Targeting Autophagy for Developing New Therapeutic Strategy in Intervertebral Disc Degeneration

Intervertebral disc degeneration (IVDD) is a prevalent cause of low back pain. IVDD is characterized by abnormal expression of extracellular matrix components such as collagen and aggrecan. In addition, it results in dysfunctional growth, senescence, and death of intervertebral cells. The biological pathways involved in the development and progression of IVDD are not fully understood. Therefore, a better understanding of the molecular mechanisms underlying IVDD could aid in the development of strategies for prevention and treatment. Autophagy is a cellular process that removes damaged proteins and dysfunctional organelles, and its dysfunction is linked to a variety of diseases, including IVDD and osteoarthritis. In this review, we describe recent research findings on the role of autophagy in IVDD pathogenesis and highlight autophagy-targeting molecules which can be exploited to treat IVDD. Many studies exhibit that autophagy protects against and postpones disc degeneration. Further research is needed to determine whether autophagy is required for cell integrity in intervertebral discs and to establish autophagy as a viable therapeutic target for IVDD.

Endothelial cells induce degradation of ECM through enhanced secretion of MMP14 carried on extracellular vesicles in venous malformation

Venous malformations (VMs), featuring localized dilated veins, are the most common developmental vascular anomalies. Aberrantly organized perivascular extracellular matrix (ECM) is one of the prominent pathological hallmarks of VMs, accounting for vascular dysfunction. Although previous studies have revealed various proteins involved in ECM remodeling, the detailed pattern and molecular mechanisms underlying the endothelium-ECM interplay have not been fully elucidated. Our previous studies revealed drastically elevated extracellular vesicle (EV) secretion in VM lesions. Here, we identified increased EV-carried MMP14 in lesion fluids of VMs and culture medium of TIE2-L914F mutant endothelial cells (ECs), along with stronger ECM degradation. Knockdown of RAB27A, a required regulator for vesicle docking and fusion, led to decreased secretion of EV-carried MMP14 in vitro. Histochemical analysis further demonstrated a highly positive correlation between RAB27A in the endothelium and MMP14 in the perivascular environment. Therefore, our results proved that RAB27A-regulated secretion of EV-MMP14, as a new pattern of endothelium-ECM interplay, contributed to the development of VMs by promoting ECM degradation.

LncRNAs in Osteoarthritis

Osteoarthritis (OA) is a progressive joint disease that affects millions of older adults around the world. With increasing rates of incidence and prevalence worldwide, OA has become an enormous global socioeconomic burden on healthcare systems. Long non-coding ribonucleic acids (lncRNAs), essential functional molecules in many biological processes, are a group of non-coding RNAs that are greater than approximately 200 nucleotides in length. Fast-growing and recent developments in lncRNA research are captivating and represent a novel and promising field in understanding the complexity of OA pathogenesis. The involvement of lncRNAs in OA's pathological processes and their altered expressions in joint tissues, blood and synovial fluid make them attractive candidates for the diagnosis and treatment of OA. We focus on the recent advances in major regulator mechanisms of lncRNAs in the pathophysiology of OA and discuss potential diagnostic and therapeutic uses of lncRNAs for OA. We investigate how upregulation or downregulation of lncRNAs influences the pathogenesis of OA and how we can use lncRNAs to elucidate the molecular mechanism of OA. Furthermore, we evaluate how we can use lncRNAs as a diagnostic marker or therapeutic target for OA. Our study not only provides a comprehensive review of lncRNAs regarding OA's pathogenesis but also contributes to the elucidation of its molecular mechanisms and to the development of diagnostic and therapeutic approaches for OA.

Calycosin prevents IL-1β-induced articular chondrocyte damage in osteoarthritis through regulating the PI3K/AKT/FoxO1 pathway

Osteoarthritis (OA) is a joint disorder that is associated with chondrocyte damage under inflammatory environment. Calycosin is an astragalus extract with potential anti-inflammatory and anti-tumor activities. The purpose of this research is to explore the activity and mechanism of calycosin in interleukin-1beta (IL-1β)-induced chondrocyte injury. In the present study, the targets of calycosin and OA were analyzed according to HERB, DisGeNet, String, GO terms, and KEGG pathway enrichment assays. Human primary chondrocytes were treated with calycosin, and stimulated with IL-1β. Cell viability was detected by CCK-8 assay. Cell apoptosis was investigated by flow cytometry, and caspase-3 activity analyses. Inflammation was analyzed according to inflammatory cytokines levels by enzyme-linked immunosorbent assay (ELISA). The proteins associated with extracellular matrix (ECM) degradation and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/forkhead box O1 (FoxO1) signaling pathways were measured using Western blotting. The results showed that total of 25 overlapping targets of calycosin against OA were predicted. These targets might drive the FoxO pathway. Calycosin alone induced little cytotoxicity to chondrocytes, and it alleviated IL-1β-induced viability inhibition, cell apoptosis, inflammatory cytokine secretion, and ECM degradation in chondrocytes. Calycosin repressed IL-1β-induced activation of the PI3K/AKT/FoxO1 signaling. Activation of the PI3K/AKT/FoxO1 signaling mitigated the suppressive effect of calycosin on chondrocyte apoptosis, inflammation, and ECM degradation induced by IL-1β. As a conclusion, calycosin prevents IL-1β-induced chondrocyte apoptosis, inflammation, and ECM degradation through inactivating the PI3K/AKT/FoxO1 pathway.

The regulatory activities of MALAT1 in the development of bone and cartilage diseases

Long non-coding RNAs (lncRNAs) have been comprehensively implicated in various cellular functions by mediating transcriptional or post-transcriptional activities. MALAT1 is involved in the differentiation, proliferation, and apoptosis of multiple cell lines, including BMSCs, osteoblasts, osteoclasts, and chondrocytes. Interestingly, MALAT1 may interact with RNAs or proteins, regulating cellular processes. Recently, MALAT1 has been reported to be associated with the development of bone and cartilage diseases by orchestrating the signaling network. The involvement of MALAT1 in the pathological development of bone and cartilage diseases makes it available to be a potential biomarker for clinical diagnosis or prognosis. Although the potential mechanisms of MALAT1 in mediating the cellular processes of bone and cartilage diseases are still needed for further elucidation, MALAT1 shows great promise for drug development.

Stress-deprivation induces an up-regulation of versican and connexin-43 mRNA and protein synthesis and increased ADAMTS-1 production in tendon cells in situ

Purpose: The proper function of the tenocyte network depends on cell-matrix as well as intercellular communication that is mechanosensitive. Building on the concept that the etiopathogenic stimulus for tendon degeneration is the catabolic response of tendon cells to mechanobiologic under-stimulation, we studied the pericellular matrix rich in versican and its predominant proteolytic enzyme ADAMTS-1, as well as Connexin-43 (Cx43), a major gap junction forming protein in tendons, in stress-deprived rat tail tendon fascicles (RTTfs).Materials and Methods: RTTfs were stress-deprived for up to 7 days under tissue culture conditions. RT-qPCR was used to measure mRNA expression of versican, ADAMTS-1, and Cx43. Protein synthesis was determined using Western blotting and immunohistochemistry.Results: Stress-deprivation (SD) caused a statistically significant up-regulation of versican, ADAMTS-1, and Cx43 mRNA expression that was persistent over the 7-day test period. Western blot analysis and immunohistochemical assessment of protein synthesis revealed a marked increase of the respective proteins with SD. Inhibition of proteolytic enzyme activity with ilomastat prevented the increased versican degradation and Cx43 synthesis in 3 days stress-deprived tendons when compared with non-treated, stress-deprived tendons.Conclusion: In the absence of mechanobiological signaling the immediate pericellular matrix is modulated as tendon cells up-regulate their production of ADAMTS-1, and versican with subsequent proteoglycan degradation potentially leading to cell signaling cues increasing Cx43 gap junctional protein. The results also provide further support for the hypothesis that the cellular changes associated with tendinopathy are a result of decreased mechanobiological signaling and a loss of homeostatic cytoskeletal tension.

High Temperature Requirement A (HtrA) protease of Listeria monocytogenes and its interaction with extracellular matrix molecules

High Temperature Requirement A (HtrA) was identified as a secreted virulence factor in many pathogenic bacteria, including Listeria monocytogenes. Recently, it was discovered that Helicobacter pylori and Campylobacter jejuni HtrAs can directly cleave the human cell-adhesion molecule E-cadherin, which facilitates bacterial transmigration. HtrAs also interact with extracellular matrix (ECM) molecules. However, only a limited number of studies have been carried out in this regard. In the present study, the protease and ECM binding properties of L. monocytogenes HtrA (LmHtrA) were studied using native rLmHtrA, catalytically inactive rLmHtrA(S343A) and rLmHtrA lacking the PDZ domain (∆PDZ) to gain more insights into HtrA-ECM molecule interaction. The results show that (1) native rLmHtrA cleaves fibrinogen, fibronectin, plasminogen and casein in a time and temperature dependent manner, (2) interaction of rLmHtrA with various host proteins was found in the micromolar to nanomolar range, (3) in the absence of PDZ domain, rLmHtrA exhibits no drastic change in binding affinity toward the host molecules when compared with native rLmHtrA and (4) the PDZ domain plays an important role in the substrate cleavage as rLmHtrA1-394∆PDZ cleaves the substrates only under certain conditions. The proteolysis of various ECM molecules by rLmHtrA possibly highlights the role of HtrA in L. monocytogenes pathogenesis involving ECM degradation.

Cellular and Molecular Mechanisms Underlying Liver Fibrosis Regression

Chronic liver injury of different etiologies may result in hepatic fibrosis, a scar formation process consisting in altered deposition of extracellular matrix. Progression of fibrosis can lead to impaired liver architecture and function, resulting in cirrhosis and organ failure. Although fibrosis was previous thought to be an irreversible process, recent evidence convincingly demonstrated resolution of fibrosis in different organs when the cause of injury is removed. In the liver, due to its high regenerative ability, the extent of fibrosis regression and reversion to normal architecture is higher than in other tissues, even in advanced disease. The mechanisms of liver fibrosis resolution can be recapitulated in the following main points: removal of injurious factors causing chronic hepatic damage, elimination, or inactivation of myofibroblasts (through various cell fates, including apoptosis, senescence, and reprogramming), inactivation of inflammatory response and induction of anti-inflammatory/restorative pathways, and degradation of extracellular matrix. In this review, we will discuss the major cellular and molecular mechanisms underlying the regression of fibrosis/cirrhosis and the potential therapeutic approaches aimed at reversing the fibrogenic process.

Dynamin 2 and BAR domain protein pacsin 2 cooperatively regulate formation and maturation of podosomes

Podosomes are actin-rich adhesion structures formed in a variety of cell types, such as monocytic cells or cancer cells, to facilitate attachment to and degradation of the extracellular matrix (ECM). Previous studies showed that dynamin 2, a large GTPase involved in membrane remodeling and actin organization, is required for podosome function. However, precise roles of dynamin 2 at the podosomes remain to be elucidated. In this study, we identified a BAR (Bin-Amphiphysin-Rvs167) domain protein pacsin 2 as a functional partner of dynamin 2 at podosomes. Dynamin 2 and pacsin 2 interact and co-localize to podosomes in Src-transformed NIH 3T3 (NIH-Src) cells. RNAi of either dynamin 2 or pacsin 2 in NIH-Src cells inhibited podosome formation and maturation, suggesting essential and related roles at podosomes. Consistently, RNAi of pacsin 2 prevented dynamin 2 localization to podosomes, and reciprocal RNAi of dynamin 2 prevented pacsin 2 localization to podosomes. Taking these results together, we conclude that dynamin 2 and pacsin 2 co-operatively regulate organization of podosomes in NIH-Src cells.

Targeting TSP-1 decreased periodontitis by attenuating extracellular matrix degradation and alveolar bone destruction

An important factor in periodontitis pathogenesis relates to a network of interactions of various cytokines. Thrombospondin-1 (TSP-1) is upregulated in several inflammatory diseases. We previously found that Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS)-induced TSP-1 production, and that TSP-1 simultaneously and effectively elevated inflammatory cytokines in THP-1 macrophages. This suggests that TSP-1 plays an important role in the pathology of periodontitis. However, the function of TSP-1 on oral cells is largely unknown. This study aimed to elucidate the underlying molecular mechanisms of TSP-1 in human periodontal fibroblasts (hPDLFs). We demonstrated that TSP-1 is highly expressed in the gingival crevicular fluid of patients with chronic periodontitis and in the inflammatory gingival tissues of rats. TSP-1 overexpression or treatment with recombinant human TSP-1(rTSP-1) promoted the expression of MMP-2, MMP-9 and RANKL/OPG in hPDLFs, while anti-TSP-1 inhibited cytokines production from P. gingivalis LPS-treated hPDLFs. Additional experiments showed that SB203580 (a special p38MAPK inhibitor) inhibited MMP-2, MMP-9 and RANKL/OPG expression induced by rTSP-1. Thus, TSP-1 effectively promoted P. gingivalis LPS-induced periodontal tissue (extracellular matrix (ECM) and alveolar bone) destruction by the p38MAPK signalling pathway, indicating that it may be a potential therapeutic target against periodontitis.

Xanthohumol Attenuated Inflammation and ECM Degradation by Mediating HO-1/C/EBPβ Pathway in Osteoarthritis Chondrocytes

Osteoarthritis (OA) is the most frequent and disabling disease in developed countries. The progressive degeneration of articular cartilage characterized as thinner and erosive. Inflammation is well-known to be involved in OA development. However, there are no effective therapeutic strategies to cure it. Xanthohumol (XH) is a natural prenylflavonoid isolated from hops and beer. The protective activity of XH against OA chondrocytes inflammation and ECM degradation is unclear. In this article, we found that XH significantly inhibited inflammatory responses, attenuated catabolic enzymes expression, and ameliorated ECM degradation, as showed by decreased production of NO, PGE2, TNFα, and IL-6, decreased expression of MMP-3/-13 and ADAMTS-4/-5, and increased expression of collagen-II and aggrecan. In addition, XH activated HO-1 signaling and attenuated IL-1β-induced C/EBPβ. XH promoted the interaction between HO-1 and C/EBPβ, inhibiting the nuclear translocation of C/EBPβ. HO-1 knockdown could abrogate the protective effects of XH in IL-1β-treated chondrocytes. Collectively, XH attenuated inflammatory responses and ECM degradation by mediating HO-1 and C/EBPβ signaling pathways in osteoarthritis chondrocytes.

MiR-126a-5p limits the formation of abdominal aortic aneurysm in mice and decreases ADAMTS-4 expression

Abdominal aortic aneurysm (AAA) is a serious vascular disease featured by inflammatory infiltration in aortic wall, aortic dilatation and extracellular matrix (ECM) degradation. Dysregulation of microRNAs (miRNAs) is implicated in AAA progress. By profiling miRNA expression in mouse AAA tissues and control aortas, we noted that miR-126a-5p was down-regulated by 18-fold in AAA samples, which was further validated with real-time qPCR. This study was performed to investigate miR-126a-5p's role in AAA formation. In vivo, a 28-d infusion of 1 μg/kg/min Angiotensin (Ang) II was used to induce AAA formation in Apoe-/- mice. MiR-126a-5p (20 mg/kg; MIMAT0000137) or negative control (NC) agomirs were intravenously injected to mice on days 0, 7, 14 and 21 post-Ang II infusion. Our data showed that miR-126a-5p overexpression significantly improved the survival and reduced aortic dilatation in Ang II-infused mice. Elastic fragment and ECM degradation induced by Ang II were also ameliorated by miR-126a-5p. A strong up-regulation of ADAM metallopeptidase with thrombospondin type 1 motif 4 (ADAMTS-4), a secreted proteinase that regulates matrix degradation, was observed in smooth muscle cells (SMCs) of aortic tunica media, which was inhibited by miR-126a-5p. Dual-luciferase results demonstrated ADAMTS-4 as a new and valid target for miR-126a-5p. In vitro, human aortic SMCs (hASMCs) were stimulated by Ang II. Gain- and loss-of-function experiments further confirmed that miR-126-5p prevented Ang II-induced ECM degradation, and reduced ADAMTS-4 expression in hASMCs. In summary, our work demonstrates that miR-126a-5p limits experimental AAA formation and reduces ADAMTS-4 expression in abdominal aortas.

MEG3 promotes proliferation and inhibits apoptosis in osteoarthritis chondrocytes by miR-361-5p/FOXO1 axis

Background

This study aimed to investigate the role of long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) and related molecular mechanisms, in osteoarthritis (OA).

Methods

Cartilage tissues of OA patients and healthy volunteers were isolated and cultured. After transfection with the appropriate constructs, chondrocytes were classified into Blank, pcDNA3.1-NC, pcDNA3.1-MEG3, si-NC, si-MEG3, pcDNA3.1-NC + mimics NC, pcDNA3.1-MEG3 + mimics NC, pcDNA3.1-NC + miR-361-5p mimics and pcDNA3.1-MEG3 + miR-361-5p mimics groups. qRT-PCR was used to detect the expression of MEG3, miR-361-5p and FOXO1. Western blot, luciferase reporter assay, RIP, CCK-8, and flow cytometry analysis were performed to reveal the morphology, proliferation, and apoptotic status of cartilage cells. Histological analysis and immunostaining were conducted in the OA rat model.

Results

Expression of MEG3 and FOXO1 was significantly decreased in OA compared with the normal group, while the expression of miR-361-5p was increased. MEG3 might serve as a ceRNA of miR-361-5p in OA chondrocytes. Moreover, using western blot analyses and the CCK-8 assay, MEG3 was shown to target miR-361-5p/FOXO1, elevate cell proliferation, and impair cell apoptosis. Functional analysis in vivo showed that MEG3 suppressed degradation of the cartilage matrix.

Conclusion

MEG3 can contribute to cell proliferation and inhibit cell apoptosis and degradation of extracellular matrix (ECM) via the miR-361-5p/FOXO1 axis in OA chondrocytes.

Icariin Alleviates IL-1β-Induced Matrix Degradation By Activating The Nrf2/ARE Pathway In Human Chondrocytes

Objective

Osteoarthritis (OA) is characterized by progressive matrix destruction of articular cartilage. This study aimed to investigate the potential antioxidative and chondroprotective effects and underlying mechanism of Icariin (ICA) in interleukin-1 beta (IL-1β)-induced extracellular matrix (ECM) degradation of OA cartilage.

Methods

Human chondrocyte cell line HC-A was treated with different doses of ICA, and then MTT assay and PI staining were used to estimate ICA-induced chondrocyte apoptosis. Intracellular ROS and superoxide dismutase (SOD) and glutathione peroxidase (GPX) were measured after treatment by IL-1β with or without ICA. The mRNA and protein expression levels of redox transcription factor Nrf2 and the downstream effector SOD-1, SOD-2, NQO-1 and HO-1 were assayed to explore the detailed mechanism by which ICA alleviates ECM degradation. Finally, to expound the role of Nrf2 in ICA-mediated chondroprotection, we specifically depleted Nrf2 in human chondrocytes and then pretreated them with ICA followed by IL-1β.

Results

ICA had no cytotoxic effects on human chondrocytes and 10⁻⁹ M was selected as the optimum concentration. ROS induced by IL-1β could drastically activate matrix-degrading proteases and ICA could significantly rescue the matrix degradation and excess ROS generation caused by IL-1β. We observed that ICA activated the Nrf2/ARE pathway, consequently upregulating the generation of GPX and SOD. Ablation of Nrf2 abrogated the chondroprotective and antioxidative effects of ICA in IL-1β-treated chondrocytes.

Conclusion

ICA alleviates IL-1β-induced matrix degradation and eliminates ROS by activating the Nrf2/ARE pathway.

Angiopoietin-like 2 upregulation promotes human chondrocyte injury via NF-κB and p38/MAPK signaling pathway

Several cellular and molecular processes participate in the pathologic changes of osteoarthritis (OA). However, the core molecular regulators of these processes are unclear, and no effective treatment for OA disease has been developed so far. ANGPTL2 is well known for its tissue remolding and pro-inflammation properties. However, the role of ANGPTL2 in osteoarthritis (OA) still remains unclear. To explore the expression level of ANGPTL2 in human OA cartilage and investigate the function of ANGPTL2 in human chondrocytes injury, qRT-PCR, western blot and immunohistochemistry were employed to investigate the expression of ANGPTL2 between human OA and normal cartilage samples. Next, human primary chondrocytes were treated with IL-1β to mimic OA progress in vitro, and the expression of ANGPTL2 were tested by qRT-PCR and western blot. Furthermore, the effect of ANGPTL2 in the expression of pro-inflammation cytokines (IL-1β, IL-6), proteolytic enzymes (MMP-1, MMP-13) and component of the cartilage matrix (COL2A1 and aggrecan) in human primary chondrocyte were explored by gain-of-function and loss-of-function methods. Finally, the nuclear factor kappa B (NF-κB) and p38/MAPK signaling pathways were also tested by western blot analysis. In this study, firstly, the expression level of ANGPTL2 was elevated both in human OA cartilage samples and IL-1β stimulated human chondrocytes. Secondly, ANGPTL2 upregulation promotes extracellular matrix (ECM) degradation and inflammation mediator production in human chondrocytes. Finally, ANGPTL2 activated the NF-κB and p38/MAPK signaling pathways via integrin α5β1. This study, for the first time, highlights that ANGPTL2 secreted by human chondrocytes plays a negative role in the pathogenesis of osteoarthritis, and it may be a potential therapeutic target in OA.

Ligustilide alleviated IL-1β induced apoptosis and extracellular matrix degradation of nucleus pulposus cells and attenuates intervertebral disc degeneration in vivo

Intervertebral disc degeneration is a multifactorial and complicated degenerative disease that imposes a huge economic burden on society. However, there is no effective treatment that can delay and reverse the progression of disc degeneration. The inflammatory response causes the death of nucleus pulposus cells and the degradation of extracellular matrix are main factors of intervertebral disc degeneration. Ligustilide is a bioactive phthalide that is said to have an anti-inflammatory effect and anti-apoptosis effect on various disorders. Therefore, we further explored the protective effect of ligustilide on intervertebral disc degeneration and its potential mechanism. In this study, we found that ligustilide inhibited apoptosis, suppressed the expression of related inflammatory mediators (iNOS and COX-2) and decreased the expression of inflammatory cytokines (TNF-a and IL-6) in nucleus pulposus cells under IL-1β stimulation. At the same time, the degradation of extracellular matrix of nucleus pulposus cells induced by IL-1β was inhibited. In addition, we also found that ligustilide inhibits the inflammation response by inhibiting the NF-κB signaling pathway. Moreover, TUNEL assay and histological analysis showed that ligustilide could inhibit the apoptosis of nucleus pulposus cells and ameliorate the progression of intervertebral disc degeneration in punctured Rat IDD model. In summary, ligustilide may become a new potential treatment for intervertebral disc degeneration.

Utility of Glycosylated TIMP3 molecules: Inhibition of MMPs and TACE to improve cardiac function in rat myocardial infarct model

Tissue Inhibitor of Metalloproteinase 3 (TIMP3) is a secreted protein that has a great utility to inhibit elevated metalloproteinase (MMP) activity in injured tissues including infarcted cardiac tissue, inflamed vessels, and joint cartilages. An imbalance between TIMP3 and active MMP levels in the local tissue area may cause worsening of disease progression. To counter balance elevated MMP levels, exogenous administration of TIMP3 appeared to be beneficial in preclinical studies. However, the current form of WT-TIMP3 molecule has a limitation to be a therapeutic candidate due to low production yield, short plasma half-life, injection site retention, and difficulty in delivery, etc. We have engineered TIMP3 molecules by adding extra glycosylation sites or fusing with albumin, Fc, and antibody to improve pharmacokinetic properties. In general, the C-terminal fusion of TIMP3 improved expression and production in mammalian cells and extended half-lives dramatically 5-20 folds. Of note, a site-specific glycosylation at K22S/F34N resulted in a higher level of expression and better cardiac function compared to other fusion proteins in the context of left ventricle ejection fraction (LVEF) changes in a rat myocardial infarction model. It appeared that cardiac efficacy depends on a high ECM binding affinity, in which K22S/F34N and N-TIMP3 showed a higher binding to the ECM compared to other engineered molecules. In conclusion, we found that the ECM binding and sustained residence of injected TIMP3 molecules are important for cardiac tissue localization and inhibition of adverse remodeling activity.

ADH1B promotes mesothelial clearance and ovarian cancer infiltration

Primary debulking surgery followed by adjuvant chemotherapy is the standard treatment for ovarian cancer. Residual disease after primary surgery is associated with poor patient outcome. Previously, we discovered ADH1B to be a molecular biomarker of residual disease. In the current study, we investigated the functional role of ADH1B in promoting ovarian cancer cell invasiveness and contributing to residual disease. We discovered that ADH1B overexpression leads to a more infiltrative cancer cell phenotype, promotes metastasis, increases the adhesion of cancer cells to mesothelial cells, and increases extracellular matrix degradation. Live cell imaging revealed that ADH1B-overexpressing cancer cells efficiently cleared the mesothelial cell layer compared to control cells. Moreover, gene array analysis revealed that ADH1B affects several pathways related to the migration and invasion of cancer cells. We also discovered that hypoxia increases ADH1B expression in ovarian cancer cells. Collectively, these findings indicate that ADH1B plays an important role in the pathways that promote ovarian cancer cell infiltration and may increase the likelihood of residual disease following surgery.

Pentagalloyl glucose increases elastin deposition, decreases reactive oxygen species and matrix metalloproteinase activity in pulmonary fibroblasts under inflammatory conditions

Emphysema is characterized by degradation of lung alveoli that leads to poor airflow in lungs. Irreversible elastic fiber degradation by matrix metalloproteinases (MMPs) and reactive oxygen species (ROS) activity leads to loss of elasticity and drives the progression of this disease. We investigated if a polyphenol, pentagalloyl glucose (PGG) can increase elastin production in pulmonary fibroblasts. We also studied the effect of PGG treatment in reducing MMP activity and ROS levels in cells. We exposed rat pulmonary fibroblasts to two different types of inflammatory environments i.e., tumor necrosis factor-α (TNF-α) and cigarette smoke extract (CSE) to mimic the disease. Parameters like lysyl oxidase (LOX) and elastin gene expression, MMP-9 activity in the medium, lysyl oxidase (LOX) activity and ROS levels were studied to assess the effect of PGG on pulmonary fibroblasts. CSE inhibited lysyl oxidase (LOX) enzyme activity that resulted in a decreased elastin formation. Similarly, TNF-α treated cells showed less elastin in the cell layers. Both these agents caused increase in MMP activity and ROS levels in cells. However, when supplemented with PGG treatment along with these two inflammatory agents, we saw a significant increase in elastin deposition, reduction in both MMP activity and ROS levels. Thus PGG, which has anti-inflammatory, anti-oxidant properties coupled with its ability to aid in elastic fiber formation, can be a multifunctional drug to potentially arrest the progression of emphysema.

Antioxidative therapy in an ex vivo human cartilage trauma-model: attenuation of trauma-induced cell loss and ECM-destructive enzymes by N-acetyl cysteine

OBJECTIVE

Mechanical trauma of articular cartilage results in cell loss and cytokine-driven inflammatory response. Subsequent accumulation of reactive oxygen (ROS) and nitrogen (RNS) species enhances the enzymatic degradation of the extracellular matrix (ECM). This study aims on the therapeutic potential of N-acetyl cysteine (NAC) in a human ex vivo cartilage trauma-model, focusing on cell- and chondroprotective features.

DESIGN

Human full-thickness cartilage explants were subjected to a defined impact trauma (0.59 J) and treated with NAC. Efficiency of NAC administration was evaluated by following outcome parameters: cell viability, apoptosis rate, anabolic/catabolic gene expression, secretion and activity of matrix metalloproteinases (MMPs) and proteoglycan (PG) release.

RESULTS

Continuous NAC administration increased cell viability and reduced the apoptosis rate after trauma. It also suppressed trauma-induced gene expression of ECM-destructive enzymes, such as ADAMTS-4, MMP-1, -2, -3 and -13 in a dosage- and time-depending manner. Subsequent suppression of MMP-2 and MMP-13 secretion reflected these findings on protein level. Moreover, NAC inhibited proteolytic activity of MMPs and reduced PG release.

CONCLUSION

In the context of this ex vivo study, we showed not only remarkable cell- and chondroprotective features, but also revealed new encouraging findings concerning the therapeutically effective concentration and treatment-time regimen of NAC. Its defense against chondrocyte apoptosis and catabolic enzyme secretion recommends NAC as a multifunctional add-on reagent for pharmaceutical intervention after cartilage injury. Taken together, our data increase the knowledge on the therapeutic potential of NAC after cartilage trauma and presents a basis for future in vivo studies.

Mechanical strength vs. degradation of a biologically-derived surgical mesh over time in a rodent full thickness abdominal wall defect

The use of synthetic surgical mesh materials has been shown to decrease the incidence of hernia recurrence, but can be associated with undesirable effects such as infection, chronic discomfort, and adhesion to viscera. Surgical meshes composed of extracellular matrix (i.e., biologically-derived mesh) are an alternative to synthetic meshes and can reduce some of these undesirable effects but are less frequently used due to greater cost and perceived inadequate strength as the mesh material degrades and is replaced by host tissue. The present study assessed the temporal association between mechanical properties and degradation of biologic mesh composed of urinary bladder matrix (UBM) in a rodent model of full thickness abdominal wall defect. Mesh degradation was evaluated for non-chemically crosslinked scaffolds with the use of (14)C-radiolabeled UBM. UBM biologic mesh was 50% degraded by 26 days and was completely degraded by 90 days. The mechanical properties of the UBM biologic mesh showed a rapid initial decrease in strength and modulus that was not proportionately associated with its degradation as measured by (14)C. The loss of strength and modulus was followed by a gradual increase in these values that was associated with the deposition of new, host derived connective tissue. The strength and modulus values were comparable to or greater than those of the native abdominal wall at all time points.

Lymphatic endothelial cells actively regulate prostate cancer cell invasion

Lymphatic vessels serve as the primary route for metastatic spread to lymph nodes. However, it is not clear how interactions between cancer cells and lymphatic endothelial cells (LECs), especially within hypoxic microenvironments, affect the invasion of cancer cells. Here, using an MR compatible cell perfusion assay, we investigated the role of LEC-prostate cancer (PCa) cell interaction in the invasion and degradation of the extracellular matrix (ECM) by two human PCa cell lines, PC-3 and DU-145, under normoxia and hypoxia, and determined the metabolic changes that occurred under these conditions. We observed a significant increase in the invasion of ECM by invasive PC-3 cells, but not poorly invasive DU-145 cells when human dermal lymphatic microvascular endothelial cells (HMVEC-dlys) were present. Enhanced degradation of ECM by PC-3 cells in the presence of HMVEC-dlys identified interactions between HMVEC-dlys and PCa cells influencing cancer cell invasion. The enhanced ECM degradation was partly attributed to increased MMP-9 enzymatic activity in PC-3 cells when HMVEC-dlys were in close proximity. Significantly higher uPAR and MMP-9 expression levels observed in PC-3 cells compared to DU-145 cells may be one mechanism for increased invasion and degradation of matrigel by these cells irrespective of the presence of HMVEC-dlys. Hypoxia significantly decreased invasion by PC-3 cells, but this decrease was significantly attenuated when HMVEC-dlys were present. Significantly higher phosphocholine was observed in invasive PC-3 cells, while higher glycerophosphocholine was observed in DU-145 cells. These metabolites were not altered in the presence of HMVEC-dlys. Significantly increased lipid levels and lipid droplets were observed in PC-3 and DU-145 cells under hypoxia reflecting an adaptive survival response to oxidative stress. These results suggest that in vivo, invasive cells in or near lymphatic endothelial cells are likely to be more invasive and degrade the ECM to influence the metastatic cascade. Copyright © 2016 John Wiley & Sons, Ltd.

RNA sequencing identifies crucial genes in papillary thyroid carcinoma (PTC) progression

PURPOSE

The study aims to uncover molecular mechanisms of PTC (papillary thyroid carcinoma) progression and provide therapeutic biomarkers.

METHODS

The paired tumor and control tissues were obtained from 5 PTC patients. RNA was extracted and cDNA libraries were constructed. RNA-sequencing (RNA-seq) was performed on the Illumina HiSeq2000 platform using paired-end method. After preprocessing of the RNA-seq data, gene expression value was calculated by RPKM. Then the differentially expressed genes (DEGs) were identified with edgeR. Functional enrichment and protein-protein interaction (PPI) network analyses were conducted for the DEGs. Module analysis of the PPI network was also performed. Transcription factors (TFs) of DEGs were predicted.

RESULTS

A cohort of 496 up-regulated DEGs mainly correlating with the ECM degradation pathways, and 440 down-regulated DEGs predominantly enriching in transmembrane transport process were identified. Hub nodes in the PPI network were RRM2 and a set of collagens (COL1A1, COL3A1 and COL5A1), which were also remarkable in module 3 and module 5, respectively. Genes in module 3 were associated with cell cycle pathways, while in module 5 were related to ECM degradation pathways. PLAU, PSG1 and EGR2 were the crucial TFs with higher transcriptional activity in PTC than in control.

CONCLUSION

Several genes including COL1A1, COL3A1, RRM2, PLAU, and EGR2 might be used as biomarkers of PTC therapy. Among them, COL1A1 and COL3A1 might exert their functions via involving in ECM degradation pathway, while RRM2 through cell cycle pathway. PLAU might be an active TF, whereas EGR2 might be a tumor suppressor.

p53 regulates cytoskeleton remodeling to suppress tumor progression

Cancer cells possess unique characteristics such as invasiveness, the ability to undergo epithelial-mesenchymal transition, and an inherent stemness. Cell morphology is altered during these processes and this is highly dependent on actin cytoskeleton remodeling. Regulation of the actin cytoskeleton is, therefore, important for determination of cell fate. Mutations within the TP53 (tumor suppressor p53) gene leading to loss or gain of function (GOF) of the protein are often observed in aggressive cancer cells. Here, we highlight the roles of p53 and its GOF mutants in cancer cell invasion from the perspective of the actin cytoskeleton; in particular its reorganization and regulation by cell adhesion molecules such as integrins and cadherins. We emphasize the multiple functions of p53 in the regulation of actin cytoskeleton remodeling in response to the extracellular microenvironment, and oncogene activation. Such an approach provides a new perspective in the consideration of novel targets for anti-cancer therapy.

Membrane-type matrix metalloproteinases: Their functions and regulations

Membrane-type matrix metalloproteinases (MT-MMPs) form a subgroup of the matrix metalloproteinase (MMP) family, and there are 6 MT-MMPs in humans. MT-MMPs are further sub-classified into type I transmembrane-type (MT1, -MT2-, MT3- and MT5-MMPs) and glycosylphosphatidylinositol (GPI)-anchored type (MT4- and MT6-MMPs). In either case MT-MMPs are tethered to the plasma membrane, and this cell surface expression provides those enzymes with unique functionalities affecting various cellular behaviours. Among the 6 MT-MMPs, MT1-MMP is the most investigated enzyme and many of its roles and regulations have been revealed to date, but the potential roles and regulatory mechanisms of other MT-MMPs are gradually getting clearer as well. Further investigations of MT-MMPs are likely to reveal novel pathophysiological mechanisms and potential therapeutic strategies for different diseases in the future.

Automated analysis of invadopodia dynamics in live cells

Multiple cell types form specialized protein complexes that are used by the cell to actively degrade the surrounding extracellular matrix. These structures are called podosomes or invadopodia and collectively referred to as invadosomes. Due to their potential importance in both healthy physiology as well as in pathological conditions such as cancer, the characterization of these structures has been of increasing interest. Following early descriptions of invadopodia, assays were developed which labelled the matrix underneath metastatic cancer cells allowing for the assessment of invadopodia activity in motile cells. However, characterization of invadopodia using these methods has traditionally been done manually with time-consuming and potentially biased quantification methods, limiting the number of experiments and the quantity of data that can be analysed. We have developed a system to automate the segmentation, tracking and quantification of invadopodia in time-lapse fluorescence image sets at both the single invadopodia level and whole cell level. We rigorously tested the ability of the method to detect changes in invadopodia formation and dynamics through the use of well-characterized small molecule inhibitors, with known effects on invadopodia. Our results demonstrate the ability of this analysis method to quantify changes in invadopodia formation from live cell imaging data in a high throughput, automated manner.