Induction of MMP-9 release from human dermal fibroblasts by thrombin: involvement of JAK/STAT3 signaling pathway in MMP-9 release. BMC Cell Biol. 2007;8:14. [PMID: 17480240 PMCID: PMC1876221 DOI: 10.1186/1471-2121-8-14]

Dimension reduction, cell clustering, and cell-cell communication inference for single-cell transcriptomics with DcjComm

Advances in single-cell transcriptomics provide an unprecedented opportunity to explore complex biological processes. However, computational methods for analyzing single-cell transcriptomics still have room for improvement especially in dimension reduction, cell clustering, and cell-cell communication inference. Herein, we propose a versatile method, named DcjComm, for comprehensive analysis of single-cell transcriptomics. DcjComm detects functional modules to explore expression patterns and performs dimension reduction and clustering to discover cellular identities by the non-negative matrix factorization-based joint learning model. DcjComm then infers cell-cell communication by integrating ligand-receptor pairs, transcription factors, and target genes. DcjComm demonstrates superior performance compared to state-of-the-art methods.

Treatment of rosacea with upadacitinib and abrocitinib: case report and review of evidence for Janus kinase inhibition in rosacea

Introduction

Conventional rosacea treatments are not uniformly pervasive, and the adverse reactions can potentially constrain their utility. The clinical use of JAK1 inhibitors upadacitinib and abrocitinib in the treatment of refractory rosacea has rarely been explored.

Case report

We presented two cases of patients who received the JAK1 inhibitor upadacitinib and four cases of patients who received the JAK1 inhibitor abrocitinib for the treatment of refractory rosacea.

Discussion

The JAK1 inhibitors upadacitinib and abrocitinib may be promising medical options for patients with refractory rosacea. However, the long-term safety and efficacy of upadacitinib and abrocitinib require prospective controlled studies to assess them more comprehensively.

Interrelationship of Osteopontin, MMP-9 and ADAMTS4 in Patients With Osteoarthritis Undergoing Total Joint Arthroplasty

Osteoarthritis (OA) is a degenerative joint disease characterized by loss of articular cartilage, inflammation and pain, which sometimes necessitates total joint arthroplasty (TJA). Profiling biomarkers of cartilage degradation and inflammation is a promising area of research to understand the pathogenesis of OA. This study aims to report the post-operative fluctuations of 3 biomarkers of OA, osteopontin (OPN), matrix metalloproteinase-9 (MMP-9), and ADAMTS4 (a disintegrin and metalloproteinase with thrombospondin motifs 4), in patients undergoing TJA to further define the interaction among these biomarkers and delineate their role in OA pathogenesis. OPN is an extracellular matrix (ECM) glycoprotein with increased activity in OA and joint damage and is upregulated by either inflammation or cleavage by MMPs and thrombin. MMP-9 is known to cleave OPN and is upregulated by inflammatory markers, such as IL-1, IL-6 and CRP. ADAMTS4 is an enzyme that degrades aggrecan, a major component of cartilage. These biomarkers were measured in deidentified blood samples collected on the day of surgery, 1 day post-operatively, and day 5-7 post-operatively. MMP-9 and OPN levels were significantly elevated at all times, and ADAMTS4 was significantly decreased at baseline versus controls. OPN and ADAMTS4 inversely fluctuated post-operatively, indicating an interrelation between these 2 biomarkers. This study suggests that the upregulation of MMP-9 and therefore OPN then results in the downregulation of ADAMTS4. The relationship between OPN and thrombin also highlights the importance of monitoring for thrombotic complications. These biomarkers, along with thrombin-mediated cleavage products, may be helpful in the prognostic management of OA patients.

Interrelationship of MMP-9, Proteoglycan-4, and Inflammation in Osteoarthritis Patients Undergoing Total Hip Arthroplasty

Osteoarthritis (OA) is a chronic condition marked by joint pain, inflammation and loss of articular cartilage, that can be treated with total joint arthroplasty (TJA) at end stages. TJA is marked by post-operative inflammation, which directly effects levels of cartilage degradation biomarkers, proteoglycan-4 (PRG4) and matrix metalloproteinase-9 (MMP-9). PRG4 is a protective glycoprotein that is decreased in individuals with OA. MMP-9 is a matrix metalloproteinase that contributes to articular cartilage loss and is elevated in OA patients. It is upregulated by pro-inflammatory markers, such as IL-1, IL-6 and CRP. This study aims to elucidate the immediate post-operative changes in levels of PRG4, MMP-9, IL-6, CRP, and WBC in patients undergoing TJA to clarify the role of inflammation in recovery after surgery and in the overall pathogenesis of OA. Blood was collected at 3 time points (day 0, day 1 post-operatively, and days 5-7 post-operatively), from 63 patients undergoing TJA due to OA, and levels of these biomarkers were quantified. IL-6, CRP, WBC and MMP-9 were lowest at day 0, highest at day 1, and stabilized at an intermediate level at days 5-7. Meanwhile, PRG4 followed the opposite trend. These studies suggest that IL-6, CRP and WBC showed predictable fluctuations, with pro-inflammatory biomarkers upregulating MMP-9 and downregulating PRG4. Measuring these biomarkers may help expose the role of inflammation in the post-surgical recovery of TJA patients and in long-term pathogenesis of OA. These levels may help risk stratify patients pre-operatively and help develop individualized post-surgical plans.

PRL-3 exerts oncogenic functions in myeloid leukemia cells via aberrant dephosphorylation of stathmin and activation of STAT3 signaling

PRL-3, an oncogenic dual-specificity phosphatase, is overexpressed in 50% of acute myeloid leukemia patients. Stathmin has been identified as a downstream target of PRL-3 in colorectal cancer. However, the correlation between PRL-3 and stathmin in myeloid leukemia is unclear. In this study, we revealed the positive correlation between PRL-3 and stathmin in myeloid leukemia. Knockdown of the PRL-3 gene by shRNA reduced the expression of downstream stathmin, suppressed cell proliferation, induced G2/M arrest and cell apoptosis, and inhibited migration and invasion in myeloid leukemia cells. Moreover, our study was the first to provide evidence that silencing PRL-3 increased the phosphorylation level in Ser16, Ser25, Ser38, and Ser63 of stathmin, and in turn inhibited the STAT3 and STAT5 signaling in myeloid leukemia cells. This evidence points to a promoted role for PRL-3 in the progression of myeloid leukemia, and PRL-3 could be a possible new treatment target.

RPN2 promotes metastasis of hepatocellular carcinoma cell and inhibits autophagy via STAT3 and NF-κB pathways

This study aimed to investigate the function and the molecular mechanism of Ribophorin II (RPN2) in regulating Hepatocellular carcinoma (HCC) cell growth, metastasis, and autophagy. Quantitative real-time PCR (qPCR), western blotting analysis, and immunofluorescence assay were utilized to detect the RPN2 expression in HCC cell lines and specimens of HCC patients. We discovered that RPN2 expression was upregulated in HCC cell lines and tissues of HCC patients, which correlated with the low histological grade and low survival rate. Enhanced RPN2 expression stimulated cell proliferation, metastasis, invasion, and epithelial-mesenchymal transition (EMT), and decreased Microtubule-associated protein light chain 3B (LC3B) synthesis and reduced the expression of p62 protein. Further studies suggested that matrix metalloproteinase 9 (MMP-9) was partially upregulated by RPN2 via Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65. Interestingly, we found that phosphorylated RPN2 activated the signal transducer and activator of transcription 3 (STAT3) in HCC cells. It was also accountable for RPN2-stimulated elevated expression of MMP-9 and for invading HCC cells. It can be concluded that over-expression of RPN2 in HCC aggravated the malignant progression into cancerous cells. This research provided new evidences that RPN2 could facilitate tumor invasion by increasing the expression of MMP-9 in HCC cells.

Natriuretic peptide receptor a promotes breast cancer development by upregulating MMP9

Natriuretic peptide receptor A (NPRA), one of the natriuretic peptide receptors, plays important roles in circulatory system. Recently some studies showed that NPRA was involved in tumorigenesis, however, its role in the development of breast cancer remains unclear. In this study, we observed that NPRA expression was upregulated in breast cancer tissues and NPRA high expression was associated with poor clinicopathological features. In addition, we found that patients with high NPRA expression had a worse 5-year survival and NPRA was an independent factor for predicting the prognosis of breast cancer patients. Knocking down NPRA expression reduced the proliferation, migration and invasion of breast cancer cells. Overexpressing NPRA was able to enhance the malignant behaviors of breast cancer cells. Furthermore, NPRA promoted the invasive phenotype through upregulating matrix metalloproteinase-9 (MMP9). Mechanistically, NPRA increased MMP9 expression through activating STAT3. We identified that NPRA might serve as a prognostic marker and p-STAT3 and MMP9 could be a potential target of NPRA in breast cancer patients.

Straight to the heart: Pleiotropic antiarrhythmic actions of oral anticoagulants

Mechanistic understanding of atrial fibrillation (AF) pathophysiology and the complex bidirectional relationship with thromboembolic risk remains limited. Oral anticoagulation is a mainstay of AF management. An emerging concept is that anticoagulants may themselves have potential pleiotropic disease-modifying effects. We here review the available evidence for hemostasis-independent actions of the oral anticoagulants on electrical and structural remodeling, and the inflammatory component of the vulnerable substrate.

Encapsulation of Rat Bone Marrow Derived Mesenchymal Stem Cells in Alginate Dialdehyde/Gelatin Microbeads with and without Nanoscaled Bioactive Glass for In Vivo Bone Tissue Engineering

Alginate dialdehyde (ADA), gelatin, and nano-scaled bioactive glass (nBG) particles are being currently investigated for their potential use as three-dimensional scaffolding materials for bone tissue engineering. ADA and gelatin provide a three-dimensional scaffold with properties supporting cell adhesion and proliferation. Combined with nanocristalline BG, this composition closely mimics the mineral phase of bone. In the present study, rat bone marrow derived mesenchymal stem cells (MSCs), commonly used as an osteogenic cell source, were evaluated after encapsulation into ADA-gelatin hydrogel with and without nBG. High cell survival was found in vitro for up to 28 days with or without addition of nBG assessed by calcein staining, proving the cell-friendly encapsulation process. After subcutaneous implantation into rats, survival was assessed by DAPI/TUNEL fluorescence staining. Hematoxylin-eosin staining and immunohistochemical staining for the macrophage marker ED1 (CD68) and the endothelial cell marker lectin were used to evaluate immune reaction and vascularization. After in vivo implantation, high cell survival was found after 1 week, with a notable decrease after 4 weeks. Immune reaction was very mild, proving the biocompatibility of the material. Angiogenesis in implanted constructs was significantly improved by cell encapsulation, compared to cell-free beads, as the implanted MSCs were able to attract endothelial cells. Constructs with nBG showed higher numbers of vital MSCs and lectin positive endothelial cells, thus showing a higher degree of angiogenesis, although this difference was not significant. These results support the use of ADA/gelatin/nBG as a scaffold and of MSCs as a source of osteogenic cells for bone tissue engineering. Future studies should however improve long term cell survival and focus on differentiation potential of encapsulated cells in vivo.

CXCL8 and CXCL11 chemokine secretion in dermal fibroblasts is differentially modulated by vanadium pentoxide

An increase in skin rashes or atopic dermatitis has been observed in individuals working with vanadium. However, to the best of our knowledge no in vivo or in vitro studies have evaluated the effect of exposure to vanadium in dermal fibroblasts. Cells viability and proliferation were assessed by WST‑1 assay, cells were treated with increasing concentrations of V2O5 (1, 10 and 100 nM). CXCL8 and CXCL11 concentrations were measured in the supernatants using an ELISA assay. V2O5 was not observed as having a significant effect on dermal fibroblast's viability and proliferation. However, it was revealed that V2O5 was able to induce the secretion of CXCL8 and CXCL11 chemokines into dermal fibroblasts. V2O5 synergistically increased the effect of interferon (IFN)γ on CXCL11 secretion. In addition, V2O5 synergistically increased the effect of the tumor necrosis factor α on CXCL8 secretion and abolished the inhibitory effect of IFNγ. V2O5 induction of CXCL8 and CXCL11 chemokines may lead to the appearance and perpetuation of an inflammatory reaction into the dermal tissue. Further studies are required to evaluate dermal integrity and manifestations in subjects occupationally exposed, or living in polluted areas.

Paradigm of Biased PAR1 (Protease-Activated Receptor-1) Activation and Inhibition in Endothelial Cells Dissected by Phosphoproteomics

OBJECTIVE

Thrombin is the key serine protease of the coagulation cascade and mediates cellular responses by activation of PARs (protease-activated receptors). The predominant thrombin receptor is PAR1, and in endothelial cells (ECs), thrombin dynamically regulates a plethora of phosphorylation events. However, it has remained unclear whether thrombin signaling is exclusively mediated through PAR1. Furthermore, mechanistic insight into activation and inhibition of PAR1-mediated EC signaling is lacking. In addition, signaling networks of biased PAR1 activation after differential cleavage of the PAR1 N terminus have remained an unresolved issue.

APPROACH AND RESULTS

Here, we used a quantitative phosphoproteomics approach to show that classical and peptide activation of PAR1 induce highly similar signaling, that low thrombin concentrations initiate only limited phosphoregulation, and that the PAR1 inhibitors vorapaxar and parmodulin-2 demonstrate distinct antagonistic properties. Subsequent analysis of the thrombin-regulated phosphosites in the presence of PAR1 inhibitors revealed that biased activation of PAR1 is not solely linked to a specific G-protein downstream of PAR1. In addition, we showed that only the canonical thrombin PAR1 tethered ligand induces extensive early phosphoregulation in ECs.

CONCLUSIONS

Our study provides detailed insight in the signaling mechanisms downstream of PAR1. Our data demonstrate that thrombin-induced EC phosphoregulation is mediated exclusively through PAR1, that thrombin and thrombin-tethered ligand peptide induce similar phosphoregulation, and that only canonical PAR1 cleavage by thrombin generates a tethered ligand that potently induces early signaling. Furthermore, platelet PAR1 inhibitors directly affect EC signaling, indicating that it will be a challenge to design a PAR1 antagonist that will target only those pathways responsible for tissue pathology.

Thrombin impairs human endometrial endothelial angiogenesis; implications for progestin-only contraceptive-induced abnormal uterine bleeding

OBJECTIVE

Progestin-only contraceptives induce abnormal uterine bleeding, accompanied by prothrombin leakage from dilated endometrial microvessels and increased thrombin generation by human endometrial stromal cell (HESC)-expressed tissue factor. Initial studies of the thrombin-treated HESC secretome identified elevated levels of cleaved chondroitin sulfate proteoglycan 4 (CSPG4), impairing pericyte-endothelial interactions. Thus, we investigated direct and CSPG4-mediated effects of thrombin in eliciting abnormal uterine bleeding by disrupting endometrial angiogenesis.

STUDY DESIGN

Liquid chromatography/tandem mass spectrometry, enzyme-linked immunosorbent assay (ELISA) and quantitative real-time-polymerase chain reaction (PCR) evaluated conditioned medium supernatant and cell lysates from control versus thrombin-treated HESCs. Pre- and post-Depo medroxyprogesterone acetate (DMPA)-administered endometria were immunostained for CSPG4. Proliferation, apoptosis and tube formation were assessed in human endometrial endothelial cells (HEECs) incubated with recombinant human (rh)-CSPG4 or thrombin or both.

RESULTS

Thrombin induced CSPG4 protein expression in cultured HESCs as detected by mass spectrometry and ELISA (p<.02, n=3). Compared to pre-DMPA endometria (n=5), stromal cells in post-DMPA endometria (n=5) displayed stronger CSPG4 immunostaining. In HEEC cultures (n=3), total tube-formed mesh area was significantly higher in rh-CSPG4 versus control (p<.05). However, thrombin disrupted HEEC tube formation by a concentration- and time-dependent reduction of angiogenic parameters (p<.05), whereas CSPG4 co-treatment did not reverse these thrombin-mediated effects.

CONCLUSION

These results suggest that disruption of HEEC tube formation by thrombin induces aberrant angiogenesis and abnormal uterine bleeding in DMPA users.

IMPLICATIONS

Mass spectrometry analysis identified several HESC-secreted proteins regulated by thrombin. Therapeutic agents blocking angiogenic effects of thrombin in HESCs can prevent or minimize progestin-only contraceptive-induced abnormal uterine bleeding.

New in vivo model to analyse the expression of angiogenic genes in the borders of a cleft lip

Defects in the fusion of facial buds can result from an anomaly in tissue development or apoptosis, or both. Our working hypothesis was that anomalies in the development of tissues could be caused by a genetic angiogenic defect. Our main objective was to design a reproducible experimental model to study the expression of angiogenic genes in the borders of cleft lips with or without cleft palate. We therefore prospectively studied seven non-syndromic patients, three with a cleft lip (2 right, 1 left), and four with a cleft lip and palate (1 bilateral, 2 right, 1 left), with no CGH (comparative genomic hybridisation) array, who had primary operations to repair their clefts. We also used four controls (cultured fibroblasts from healthy skin samples). The mean (range) age at operation was 44 (13-77) days. We studied the lateral and medial borders histologically and did qPCR (quantitative real-time polymerase chain reaction) analysis for gene expression with 22 genes of interest (and two housekeeping genes) involved in cleft lip and angiogenesis. The qPCR analysis found significant (p<0.05) overexpression of eight genes in the medial border and seven in the lateral border, and underexpression of nine genes in the medial, and ten in the lateral border. The difference in expression between the two borders was not significant. This preliminary study has enabled us to develop a new method to analyse the expression of angiogenic genes in the borders of cleft lips.

Downregulation of the N-myc downstream regulated gene 1 is related to enhanced proliferation, invasion and migration of pancreatic cancer

The N-myc downstream regulated gene 1 (NDRG1) is differently expressed in human malignancies according to the tumor type. We investigated the expression of NDRG1 in pancreatic cancer tissues and cell lines as well as how it affects tumor growth, invasion and migration in pancreatic cancer cells. Experimental groups included NDRG1 overexpression and knockdown pancreatic cancer cell lines. Lentivirus-based empty vector transfected cells (NC group) were considered control groups. Proliferation, invasion and migration related proteins such as STAT3, MMPs, PTEN, PI3K/AKT were assessed by CCK-8, Transwell assay and western blotting. Efficient NDRG1 overexpression results in reduced cell proliferation, invasion and migration. Inversely, downregulation of NDRG1 promoted proliferation, invasion and migration. We also found NDRG1 could deactivate p-STAT3, PI3K, p-AKT, MMP2, MMP9 and activate PTEN. NDRG1 is a potential anti-oncogene. Its upregulation significantly decreases pancreatic cancer tumorigenesis, likely by inhibiting STAT3 and the PI3K/AKT signaling pathway.

Expression of proteinase-activated receptor (PAR)-2 in monocytes from allergic patients and potential molecular mechanism

Serine proteases play an important role in inflammation via PARs. However, little is known of expression levels of PARs on monocytes of allergic patients, and influence of serine proteases and PARs on TNF-α secretion from monocytes. Using quantitative real-time PCR (qPCR) and flowcytometry techniques, we observed that the expression level of PAR-2 in monocytes of patients with allergic rhinitis and asthma was increased by 42.9 and 38.2 %. It was found that trypsin, thrombin, and tryptase induced up to 200, 320, and 310 % increase in TNF-α release from monocytes at 16 h, respectively. PAR-1 agonist peptide, SFLLR-NH₂, and PAR-2 agonist peptide tc-LIGRLO-NH₂ provoked up to 210 and 240 % increase in release of TNF-α. Since SCH 79797, a PAR-1 antagonist, and PD98059, an inhibitor of ERK inhibited thrombin- and SFLLR-NH₂-induced TNF-α release, the action of thrombin is most likely through a PAR-1- and ERK-mediated signaling mechanism. Similarly, because FSLLRN-NH₂, an inhibitor of PAR-2 diminished tryptase- and tc-LIGRLO-NH₂-induced TNF-α release, the action of tryptase appears PAR-2 dependent. Moreover, in vivo study showed that both recombinant cockroach major allergens Per a 1 and Per a 7 provoked upregulation of PAR-2 and PAR-1 expression on CD14+ cells in OVA-sensitized mouse peritoneum. In conclusion, increased expression of PAR-2 in monocytes of AR and asthma implicates that PAR-2 likely play a role in allergy. PAR-2- and PAR-1-mediated TNF-α release from monocytes suggests that these unique protease receptors are involved in the pathogenesis of inflammation.

Mesenchymal stem cells protect against obstruction-induced renal fibrosis by decreasing STAT3 activation and STAT3-dependent MMP-9 production

STAT3 is a transcription factor implicated in renal fibrotic injury, but the role of STAT3 in mesenchymal stem cell (MSC)-induced renoprotection during renal fibrosis remains unknown. We hypothesized that MSCs protect against obstruction-induced renal fibrosis by downregulating STAT3 activation and STAT3-induced matrix metalloproteinase-9 (MMP-9) expression. Male Sprague-Dawley rats underwent renal arterial injection of vehicle or MSCs (1 × 10⁶/rat) immediately before sham operation or induction of unilateral ureteral obstruction (UUO). The kidneys were harvested after 4 wk and analyzed for collagen I and III gene expression, collagen deposition (Masson's trichrome), fibronectin, α-smooth muscle actin, active STAT3 (p-STAT3), MMP-9, and tissue inhibitor of matrix metalloproteinases 1 (TIMP-1) expression. In a separate arm, the STAT3 inhibitor S3I-201 (10 mg/kg) vs. vehicle was administered to rats intraperitoneally just after induction of UUO and daily for 14 days thereafter. The kidneys were harvested after 2 wk and analyzed for p-STAT3 and MMP-9 expression, and collagen and fibronectin deposition. Renal obstruction induced a significant increase in collagen, fibronectin, α-SMA, p-STAT3, MMP-9, and TIMP-1 expression while exogenously administered MSCs significantly reduced these indicators of obstruction-induced renal fibrosis. STAT3 inhibition with S3I-201 significantly reduced obstruction-induced MMP-9 expression and tubulointerstitial fibrosis. These results demonstrate that MSCs protect against obstruction-induced renal fibrosis, in part, by decreasing STAT3 activation and STAT3-dependent MMP-9 production.

Role of STAT3 Phosphorylation in Ethanol-Mediated Proliferation of Breast Cancer Cells

Purpose

In this study, we investigated the molecular mechanism involved in ethanol (EtOH)-mediated proliferation of breast cancer cells.

Methods

EtOH concentration was optimized by studying its effect on cell proliferation in MCF-7 and MDA MB-231 cells. We used flow cytometry and immunoblot analysis to evaluate the increased proliferation caused by the optimized concentrations of EtOH. The mechanism of EtOH-mediated proliferation was determined using reactive oxygen species (ROS) release assay, reverse transcription polymerase chain reaction, and immunoblot studies. Gene silencing followed by quantitative real-time polymerase chain reaction studies and inhibitor studies indicated the involvement of signal transducer and activator of transcription 3 (STAT3) in EtOH-mediated breast cancer proliferation.

Results

Exposure to EtOH caused an increase in cell proliferation and an accumulation of cells in S-phase in MCF-7 (347 µM EtOH) and MDA MB-231 (173 µM EtOH) cells. Additionally, increased release of ROS and the expression of pro-inflammatory cytokines, such as interleukin 6 and tumor necrosis factor α, confirmed that the proliferation was induced by the ROS-linked inflammatory response in breast cancer. The proinflammatory response was followed by phosphorylation of STAT3. The importance of STAT3 activation in EtOH-mediated proliferation was confirmed through the silencing of STAT3, followed by an investigation on the expression of cyclins and matrix metalloproteinases. Finally, studies using specific inhibitors indicated that the EtOH-mediated effect on STAT3 activation could be regulated by phosphoinositide-3-kinase and Janus kinase 2.

Conclusion

The study demonstrates the involvement of STAT3 signaling in EtOH-mediated breast cancer proliferation.

Oncostatin M and leukaemia inhibitory factor trigger signal transducer and activator of transcription 3 and extracellular signal-regulated kinase 1/2 pathways but result in heterogeneous cellular responses in trophoblast cells

Leukaemia inhibitory factor (LIF) and oncostatin M (OSM) are pleiotropic cytokines present at the implantation site that are important for the normal development of human pregnancy. These cytokines share the cell membrane receptor subunit gp130, resulting in similar functions. The aim of this study was to compare the response to LIF and OSM in several trophoblast models with particular regard to intracellular mechanisms and invasion. Four trophoblast cell lines with different characteristics were used: HTR-8/SVneo, JEG-3, ACH-3P and AC1-M59 cells. Cells were incubated with LIF, OSM (both at 10 ng mL–1) and the signal transducer and activator of transcription (STAT) 3 inhibitor S3I-201 (200 µM). Expression and phosphorylation of STAT3 (tyr705) and extracellular regulated kinase (ERK) 1/2 (thr202/204) and the STAT3 DNA-binding capacity were analysed by Western blotting and DNA-binding assays, respectively. Cell viability and invasiveness were assessed by the methylthiazole tetrazolium salt (MTS) and Matrigel assays. Enzymatic activity of matrix metalloproteinase (MMP)-2 and MMP-9 was investigated by zymography. OSM and LIF triggered phosphorylation of STAT3 and ERK1/2, followed by a significant increase in STAT3 DNA-binding activity in all tested cell lines. Stimulation with LIF but not OSM significantly enhanced invasion of ACH-3P and JEG-3 cells, but not HTR-8/SVneo or AC1-M59 cells. Similarly, STAT3 inhibition significantly decreased the invasiveness of only ACH-3P and JEG-3 cells concomitant with decreases in secreted MMP-2 and MMP-9. OSM shares with LIF the capacity to activate ERK1/2 and STAT3 pathways in all cell lines tested, but their resulting effects are dependent on cell type. This suggests that LIF and OSM may partially substitute for each other in case of deficiencies or therapeutic interventions.

Impact of high glucose on metastasis of colon cancer cells

AIM: To investigate the possible mechanism of how glucose promotes invasion and metastasis of colon cancer cells.

METHODS: CT-26 rat colorectal cancer cells were cultured in different concentrations of glucose environments (10, 20, and 30 mmol/L). Wound healing assay and transwell chamber invasion assay were utilized to test the migration and invasion, respectively. In order to understand the role of signal transducer and activator of transcription 3 (STAT3) in the process, STAT3 inhibitors, including Stattic (an STAT3 specific inhibitor) and small interfering RNA targeting STAT3, were used to block STAT3 function to evaluate their impact on CT-26 cell motion. To verify whether STAT3 and matrix metalloproteinase-9 (MMP-9) protein expression is associated with glucose-induced cell movement, Western blot was used to compare the differences in the expression of MMP-9 and STAT3 in cells incubated with and without STAT3 inhibitors in high glucose condition.

RESULTS: In both wound healing and invasion assays, the migration and invasion of CT-26 cells increased gradually with the increase in glucose concentration. However, the glucose-induced migration and invasion were obviously inhibited by STAT3 inhibitors (P < 0.05). Similarly, in Western blot assessment, both MMP-9 and STAT3 expression increased under a high glucose environment and the highest expression was achieved when 30 mmol/L glucose was used. However, in cells treated with 30 mmol/L mannitol, either MMP-9 or STAT3 expression did not increase (P > 0.05). When STAT3 inhibitors were added in the 30 mM glucose group, not only STAT3 but also MMP-9 expression decreased significantly (P < 0.05).

CONCLUSION: Our study provides evidence that glucose can promote both migration and invasion of CT-26 cells, and that the STAT3-induced MMP-9 signal pathway is involved in this process.

Effects of tissue factor, PAR-2 and MMP-9 expression on human breast cancer cell line MCF-7 invasion

OBJECTIVE

This study aimed to explore the expression of tissue factor (TF), protease activated receptor-2 (PAR-2), and matrix metalloproteinase-9 (MMP-9) in the MCF-7 breast cancer cell line and influence on invasiveness.

METHODS

Stable MCF-7 cells transfected with TF cDNA and with TF ShRNA were established. TF, PAR-2, and MMP-9 protein expression was analyzed using indirect immunofluorescence and invasiveness was evaluated using a cell invasion test. Effects of an exogenous PAR-2 agonist were also examined.

RESULTS

TF protein expression significantly differed between the TF cDNA and TF ShRNA groups. MMP-9 protein expression was significantly correlated with TF protein expression, but PAR-2 protein expression was unaffected. The PAR- 2 agonist significantly enhanced MMP-9 expression and slightly increased TF and PAR-2 expression in the TF ShRNA group, but did not significantly affect protein expression in MCF-7 cells transfected with TF cDNA. TF and MMP-9 expression was positively correlated with the invasiveness of tumor cells.

CONCLUSION

TF, PAR-2, and MMP-9 affect invasiveness of MCF-7 cells. TF may increase MMP-9 expression by activating PAR-2.

A novel small molecular STAT3 inhibitor, LY5, inhibits cell viability, cell migration, and angiogenesis in medulloblastoma cells

Signal transducers and activators of transcription 3 (STAT3) signaling is persistently activated and could contribute to tumorigenesis of medulloblastoma. Numerous studies have demonstrated that inhibition of the persistent STAT3 signaling pathway results in decreased proliferation and increased apoptosis in human cancer cells, indicating that STAT3 is a viable molecular target for cancer therapy. In this study, we investigated a novel non-peptide, cell-permeable small molecule, named LY5, to target STAT3 in medulloblastoma cells. LY5 inhibited persistent STAT3 phosphorylation and induced apoptosis in human medulloblastoma cell lines expressing constitutive STAT3 phosphorylation. The inhibition of STAT3 signaling by LY5 was confirmed by down-regulating the expression of the downstream targets of STAT3, including cyclin D1, bcl-XL, survivin, and micro-RNA-21. LY5 also inhibited the induction of STAT3 phosphorylation by interleukin-6 (IL-6), insulin-like growth factor (IGF)-1, IGF-2, and leukemia inhibitory factor in medulloblastoma cells, but did not inhibit STAT1 and STAT5 phosphorylation stimulated by interferon-γ (IFN-γ) and EGF, respectively. In addition, LY5 blocked the STAT3 nuclear localization induced by IL-6, but did not block STAT1 and STAT5 nuclear translocation mediated by IFN-γ and EGF, respectively. A combination of LY5 with cisplatin or x-ray radiation also showed more potent effects than single treatment alone in the inhibition of cell viability in human medulloblastoma cells. Furthermore, LY5 demonstrated a potent inhibitory activity on cell migration and angiogenesis. Taken together, these findings indicate LY5 inhibits persistent and inducible STAT3 phosphorylation and suggest that LY5 is a promising therapeutic drug candidate for medulloblastoma by inhibiting persistent STAT3 signaling.

Evaluation on potential contributions of protease activated receptors related mediators in allergic inflammation

Protease activated receptors (PARs) have been recognized as a distinctive four-member family of seven transmembrane G protein-coupled receptors (GPCRs) that can be cleaved by certain serine proteases. In recent years, there has been considerable interest in the role of PARs in allergic inflammation, the fundamental pathologic changes of allergy, but the potential roles of PARs in allergy remain obscure. Since many of these proteases are produced and actively involved in the pathologic process of inflammation including exudation of plasma components, inflammatory cell infiltration, and tissue damage and repair, PARs appear to make important contribution to allergy. The aim of the present review is to summarize the expression of PARs in inflammatory and structural cells, the influence of agonists or antagonists of PARs on cell behavior, and the involvement of PARs in allergic disorders, which will help us to better understand the roles of serine proteases and PARs in allergy.

The application of the starfish hatching enzyme for the improvement of scar and keloid based on the fibroblast-populated collagen lattice

Various bioactivities of the starfish hatching enzyme (HE) including collagen gel contraction, MMPs activity, hydroxyproline release, and gene regulation based on the fibroblast-populated collagen lattice (FPCL) in three-dimensional medium were investigated for the improvement of scar and keloid. The starfish HE significantly inhibited the collagen gel contraction over 2 days of culture. MMP-2 and MMP-9 activities were also identified by gelatin zymography and RT-PCR products with both HE and collagenase treatments, which resulted in the high amount of hydroxyproline release. The HE treatment on the FPCL significantly inhibited the fibroblast proliferation at 3 days of culture. The LPS-induced NO level and iNOS mRNA expression at low concentrations of HE presented a certain ability to inflammatory response. The COX-2 mRNA from the FPCL indicated no significant inflammation-mediated activity at 5 μg/mL of HE, whereas the cytokines of TNF-α and IL-1β were significantly higher than those of the control. Hence, the starfish hatching enzyme can regulate the fibroblast-populated collagen gel conditions by the contraction, MMP production, inflammatory gene expression, etc. Therefore, the starfish HE could be a potential cosmeceutical to heal the scar and keloid tissue.

A host deficiency of discoidin domain receptor 2 (DDR2) inhibits both tumour angiogenesis and metastasis

Discoidin domain receptor 2 (DDR2) is a unique receptor tyrosine kinase (RTK) that signals in response to collagen binding and is implicated in tumour malignant phenotypes such as invasion and metastasis. Although it has been reported that DDR2 expression is up-regulated in activated endothelial cells (ECs), functional studies are lacking. Herein, we found that enforced expression of DDR2 promoted proliferation, migration and tube formation of primary human umbilical vein endothelial cells (HUVECs). The results of immunohistochemical analysis showed a strikingly high level of DDR2 in human tumour ECs. Most significantly, we discovered that a host deficiency of DDR2 inhibits subcutaneous angiogenesis induced by either VEGF or tumour cells. In addition, the remaining tumour vessels in DDR2-deficient mice exhibit some normalized properties. These vascular phenotypes are accompanied by the up-regulation of anti-angiogenic genes and down-regulation of pro-angiogenic genes, as well as by alleviated tumour hypoxia. By use of a tail vein metastasis model of melanoma, we uncovered that loss of stromal DDR2 also suppresses tumour metastasis to the lung. Hence, our current data disclose a new mechanism by which DDR2 affects tumour progression, and may strengthen the feasibility of targeting DDR2 as an anticancer strategy.

CCR1-mediated STAT3 tyrosine phosphorylation and CXCL8 expression in THP-1 macrophage-like cells involve pertussis toxin-insensitive Gα(14/16) signaling and IL-6 release

Agonists of CCR1 contribute to hypersensitivity reactions and atherosclerotic lesions, possibly via the regulation of the transcription factor STAT3. CCR1 was demonstrated to use pertussis toxin-insensitive Gα(14/16) to stimulate phospholipase Cβ and NF-κB, whereas both Gα(14) and Gα(16) are also capable of activating STAT3. The coexpression of CCR1 and Gα(14/16) in human THP-1 macrophage-like cells suggests that CCR1 may use Gα(14/16) to induce STAT3 activation. In this study, we demonstrated that a CCR1 agonist, leukotactin-1 (CCL15), could indeed stimulate STAT3 Tyr(705) and Ser(727) phosphorylation via pertussis toxin-insensitive G proteins in PMA-differentiated THP-1 cells, human erythroleukemia cells, and HEK293 cells overexpressing CCR1 and Gα(14/16). The STAT3 Tyr(705) and Ser(727) phosphorylations were independent of each other and temporally distinct. Subcellular fractionation and confocal microscopy illustrated that Tyr(705)-phosphorylated STAT3 translocated to the nucleus, whereas Ser(727)-phosphorylated STAT3 was retained in the cytosol after CCR1/Gα(14) activation. CCL15 was capable of inducing IL-6 and IL-8 (CXCL8) production in both THP-1 macrophage-like cells and HEK293 cells overexpressing CCR1 and Gα(14/16). Neutralizing Ab to IL-6 inhibited CCL15-mediated STAT3 Tyr(705) phosphorylation, whereas inhibition of STAT3 activity abolished CCL15-activated CXCL8 release. The ability of CCR1 to signal through Gα(14/16) provides a linkage for CCL15 to regulate IL-6/STAT3-signaling cascades, leading to expression of CXCL8, a cytokine that is involved in inflammation and the rupture of atherosclerotic plaque.

Bone marrow-derived matrix metalloproteinase-9 is associated with fibrous adhesion formation after murine flexor tendon injury

The pathogenesis of adhesions following primary tendon repair is poorly understood, but is thought to involve dysregulation of matrix metalloproteinases (Mmps). We have previously demonstrated that Mmp9 gene expression is increased during the inflammatory phase following murine flexor digitorum (FDL) tendon repair in association with increased adhesions. To further investigate the role of Mmp9, the cellular, molecular, and biomechanical features of healing were examined in WT and Mmp9^−/− mice using the FDL tendon repair model. Adhesions persisted in WT, but were reduced in Mmp9^−/− mice by 21 days without any decrease in strength. Deletion of Mmp9 resulted in accelerated expression of neo-tendon associated genes, Gdf5 and Smad8, and delayed expression of collagen I and collagen III. Furthermore, WT bone marrow cells (GFP⁺) migrated specifically to the tendon repair site. Transplanting myeloablated Mmp9^−/− mice with WT marrow cells resulted in greater adhesions than observed in Mmp9^−/− mice and similar to those seen in WT mice. These studies show that Mmp9 is primarily derived from bone marrow cells that migrate to the repair site, and mediates adhesion formation in injured tendons. Mmp9 is a potential target to limit adhesion formation in tendon healing.

STAT3 knockdown reduces pancreatic cancer cell invasiveness and matrix metalloproteinase-7 expression in nude mice

Aims

Transducer and activator of transcription-3 (STAT3) plays an important role in tumor cell invasion and metastasis. The aim of the present study was to investigate the effects of STAT3 knockdown in nude mouse xenografts of pancreatic cancer cells and underlying gene expression.

Methods

A STAT3 shRNA lentiviral vector was constructed and infected into SW1990 cells. qRT-PCR and western immunoblot were performed to detect gene expression. Nude mouse xenograft assays were used to assess changes in phenotypes of these stable cells in vivo. HE staining was utilized to evaluate tumor cell invasion and immunohistochemistry was performed to analyze gene expression.

Results

STAT3 shRNA successfully silenced expression of STAT3 mRNA and protein in SW1990 cells compared to control cells. Growth rate of the STAT3-silenced tumor cells in nude mice was significantly reduced compared to in the control vector tumors and parental cells-generated tumors. Tumor invasion into the vessel and muscle were also suppressed in the STAT3-silenced tumors compared to controls. Collagen IV expression was complete and continuous surrounding the tumors of STAT3-silenced SW1990 cells, whereas collagen IV expression was incomplete and discontinuous surrounding the control tumors. Moreover, microvessel density was significantly lower in STAT3-silenced tumors than parental or control tumors of SW1990 cells. In addition, MMP-7 expression was reduced in STAT3-silenced tumors compared to parental SW1990 xenografts and controls. In contrast, expression of IL-1β and IgT7α was not altered.

Conclusion

These data clearly demonstrate that STAT3 plays an important role in regulation of tumor growth, invasion, and angiogenesis, which could be act by reducing MMP-7 expression in pancreatic cancer cells.

Thrombin-induced Migration and Matrix Metalloproteinase-9 Expression Are Regulated by MAPK and PI3K Pathways in C6 Glioma Cells

Glioblastoma multiforme is one of the most common and aggressive tumors in central nervous system. It often possesses characteristic necrotic lesions with hemorrhages, which increase the chances of exposure to thrombin. Thrombin has been known as a regulator of MMP-9 expression and cancer cell migration. However, the effects of thrombin on glioma cells have not been clearly understood. In the present study, influences of thrombin on glioma cell migration were examined using Boyden chamber migration assay and thrombin-induced changes in MMP-9 expression were measured using zymography, semi-quantitative RT-PCR, and Western blotting. Furthermore, underlying signaling pathways by which thrombin induces MMP-9 expression were examined. Thrombin-induced migration and MMP-9 expression were significantly potentiated in the presence of wortmannin, a PI3K inhibitor, whereas MAPK inhibitors suppressed thrombin-induced migration and MMP-9 expression in C6 glioma cells. The present data strongly demonstrate that MAPK and PI3K pathways evidently regulate thrombin-induced migration and MMP-9 expression of C6 glioma cells. Therefore, the control of these pathways might be a beneficial therapeutic strategy for treatment of invasive glioblastoma multiforme.

Identification of a structural motif in the tumor-suppressive protein GRIM-19 required for its antitumor activity

We have previously isolated GRIM-19, a novel growth suppressor, using a genetic method. GRIM-19 ablates cell growth by inhibiting the transcription factor signal transducer and activator of transcription 3 (STAT3). Up-regulation of STAT3 and growth promotion were observed in a number of human tumors. Although the tumor-suppressive actions of GRIM-19 are known, the structural elements required for its antitumor actions are not understood. Mutational and protein sequence analyses identified a motif in the N terminus of GRIM-19 that exhibited similarity to certain RNA viral proteins. We show that disruption of specific amino acids within this motif cripples the antitumor actions of GRIM-19. These mutants fail to interact with STAT3 efficiently and consequently do not inhibit growth-promoting gene expression. More importantly, we show that a clinically observed mutation in the N terminus of GRIM-19 also weakened its interaction with STAT3 and antitumor action. Together, these studies identify a major role for the N terminus of GRIM-19 in mediating its tumor-suppressive actions.

Down-regulation of GRIM-19 expression is associated with hyperactivation of STAT3-induced gene expression and tumor growth in human cervical cancers

Cervical cancer is the most common malignant disease responsible for the deaths of a large number of women in the developing world. Although certain strains of human papillomavirus (HPV) have been identified as the cause of this disease, events that lead to formation of malignant tumors are not fully clear. STAT3 is a major oncogenic transcription factor involved in the development and progression of a number of human tumors. However, the mechanisms that result in loss of control over STAT3 activity are not understood. Gene associated with Retinoid-Interferon-induced Mortality-19 (GRIM-19) is a tumor-suppressive protein identified using a genetic technique in the interferon/retinoid-induced cell death pathway. Here, we show that reduction in GRIM-19 protein levels occur in a number of primary human cervical cancers. Consequently, these tumors tend to express a high basal level of STAT3 and its downstream target genes. More importantly, using a surrogate model, we show that restoration of GRIM-19 levels reestablishes the control over STAT3-dependent gene expression and tumor growth in vivo. GRIM-19 suppressed the expression of tumor invasion- and angiogenesis-associated factors to limit tumor growth. This study identifies another major novel molecular pathway inactivated during the development of human cervical cancer.

The effect of epigallocatechin-3-gallate, a constituent of green tea, on transforming growth factor-beta1-stimulated wound contraction

Dermal fibrosis, or scarring, following surgical incisions, traumatic wounds and burns presents a major clinical burden. Transforming growth factor (TGF)-beta1 is a major factor known to stimulate fibroblast proliferation, collagen production, and the differentiation of fibroblast to myofibroblast promoting wound contraction. Furthermore, excessive or prolonged TGF-beta1 has been shown to be associated with scarring. Green tea contains high amounts of polyphenols with the major polyphenolic compound being epigallocatechin-3-gallate (EGCG). EGCG has been shown to be anti-inflammatory, anti-oxidant, and may improve wound healing and scarring, though its precise effect on TGF-beta1 remains unclear. This study aimed at determining the effect of EGCG on TGF-beta1 collagen contraction, gene expression and the differentiation of fibroblast to myofibroblast. EGCG appears to affect the role that TGF-beta1 plays in fibroblast populated collagen gel contraction and this seems to be through both myofibroblast differentiation and connective tissue growth factor gene expression and reduces the expression of collagen type I gene regulation.

Thrombin-mediated impairment of fibroblast growth factor-2 activity

Thrombin generation increases in several pathological conditions, including cancer, thromboembolism, diabetes and myeloproliferative syndromes. During tumor development, thrombin levels increase along with several other molecules, including cytokines and angiogenic factors. Under such conditions, it is reasonable to predict that thrombin may recognize new low-affinity substrates that usually are not recognized under low-expression levels conditions. In the present study, we hypothesized that fibroblast growth factor (FGF)-2 may be cleaved by thrombin and that such action may lead to an impairment of its biological activity. The evidence collected in the present study indicates that FGF-2-induced proliferation and chemotaxis/invasion of SK-MEL-110 human melanoma cells were significantly reduced when FGF-2 was pre-incubated with active thrombin. The inhibition of proliferation was not influenced by heparin. Phe-Pro-Arg-chloromethyl ketone, a specific inhibitor of the enzymatic activity of thrombin, abolished the thrombin-induced observed effects. Accordingly, both FGF-2-binding to cell membranes as well as FGF-2-induced extracellular signal-regulated kinase phosphorylation were decreased in the presence of thrombin. Finally, HPLC analyses demonstrated that FGF-2 is cleaved by thrombin at the peptide bond between residues Arg42 and Ile43 of the mature human FGF-2 sequence. The apparent k(cat)/K(m) of FGF-2 hydrolysis was 1.1 x 10(4) M(-1) x s(-1), which is comparable to other known low-affinity thrombin substrates. Taken together, these results demonstrate that thrombin digests FGF-2 at the site Arg42-Ile43 and impairs FGF-2 activity in vitro, indicating that FGF-2 is a novel thrombin substrate.

Thrombin induces osteoprotegerin synthesis via phosphatidylinositol 3'-kinase/mammalian target of rapamycin pathway in human periodontal ligament cells

BACKGROUND AND OBJECTIVE

Thrombin influences the biological behavior of periodontal ligament cells and plays multiple roles in the early stages of bone healing. Osteoprotegerin (OPG) is one of the key molecules that regulate bone homeostasis and prevent osteoclastogenesis. The purpose of this study was to evaluate the biological effects of thrombin on OPG synthesis in human periodontal ligament (HPDL) cells in vitro.

MATERIAL AND METHODS

Cells were treated with various concentrations (0.001, 0.01 and 0.1 U/mL) of thrombin. The mRNA expression and protein synthesis of OPG, as well as of receptor activator of nuclear factor kappaB ligand (RANKL), were determined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. The influence of thrombin on OPG synthesis and its signaling pathway were investigated using inhibitors.

RESULTS

Thrombin profoundly induces protein synthesis of OPG at 0.1 U/mL. The inductive effect was inhibited by cycloheximide, but not by indomethacin. The phosphatidylinositol 3'-kinase (PI3K) inhibitor, LY294002, and the mammalian target of rapamycin (mTOR) inhibitor, rapamycin, exerted an inhibitory effect on the thrombin-induced OPG synthesis. In addition, the effect was inhibited by protease-activated receptor (PAR)-1 antagonist. Activation of phospho-Akt (p-Akt) was observed and the effect was abolished by LY294002.

CONCLUSION

Thrombin induces OPG synthesis in HPDL cells post-transcriptionally, possibly through PAR-1. The regulation was through the PI3K/Akt and mTOR pathway. This finding suggests that thrombin may play a significant role in alveolar bone repair and homeostasis of periodontal tissue, partly through the OPG/RANKL system.

Proteinase-activated receptor-1-triggered activation of tumor progression locus-2 promotes actin cytoskeleton reorganization and cell migration

Tumor progression locus 2 (Tpl2), a mitogen-activated protein kinase kinase kinase (MAP3K) that is activated by provirus insertion in retrovirus-induced rodent lymphomas and mammary adenocarcinomas, is known to transduce Toll-like receptor, interleukin 1, tumor necrosis factor alpha, and CD40 signals and to play an important role in inflammation. Here we show that Tpl2 is also required for the transduction of cell migration and gene expression signals originating in the G-protein-coupled receptor proteinase-activated receptor 1 (PAR1). PAR1 signals transduced by Tpl2 activate Rac1 and focal adhesion kinase, and they are required for reorganization of the actin cytoskeleton and cell migration. PAR1 expressed in fibroblasts can be triggered by proteinases produced by tumor cells, and PAR1 expressed in tumor cells can be triggered by proteinases produced by fibroblasts. These data suggest that signals that regulate cell migration and gene expression flow between stromal and tumor cells in both directions and that Tpl2 plays a pivotal role in this process.