TNF-α stimulates colonic myofibroblast migration via COX-2 and Hsp27

Intestinal Stromal Cells in the Turmoil of Inflammation and Defective Connective Tissue Remodeling in Inflammatory Bowel Disease

In steady state, intestinal subepithelial myofibroblasts form a thin layer below the basement membrane. Unlike the rest of the stromal cells in the lamina propria, they express tensile proteins, guide epithelial regeneration, and sense luminal microbiota. Upon inflammation in inflammatory bowel disease (IBD), they express activation markers, accept trophic signaling by infiltrating neutrophils and macrophages, and are activated by cytokines from helper T cells to produce a narrow spectrum of cytokines and a wider spectrum of chemokines, attract cells of innate and adaptive immunity, orchestrate inflammatory responses, and qualitatively and quantitatively modify the extracellular matrix. Thus, beyond being structural tissue components, they assume active roles in the pathogenesis of complicated IBD. Discrimination between myofibroblasts and fibroblasts may be an oversimplification in light of single-cell sequencing data unveiling the complexity of multiple phenotypes of stromal cells with distinct roles and plasticity. Spatial transcriptomics revealed distinct phenotypes by histologic localization and, more intriguingly, the assembly of mucosal neighborhoods that support spatially distinct functions. Current IBD treatments target inflammation but fail in fibrostenotic or fistulizing disease. Baseline and recent findings on stromal cells, molecules, and pathways involved in disrupted extracellular matrix homeostasis are reviewed to provide relevant pharmacologic targets.

Inflammation accelerating intestinal fibrosis: from mechanism to clinic

Intestinal fibrosis is a prevalent complication of IBD that that can frequently be triggered by prolonged inflammation. Fibrosis in the gut can cause a number of issues, which continue as an ongoing challenge to healthcare systems worldwide. The primary causes of intestinal fibrosis are soluble molecules, G protein-coupled receptors, epithelial-to-mesenchymal or endothelial-to-mesenchymal transition, and the gut microbiota. Fresh perspectives coming from in vivo and in vitro experimental models demonstrate that fibrogenic pathways might be different, at least to some extent, independent of the ones that influence inflammation. Understanding the distinctive procedures of intestinal fibrogenesis should provide a realistic foundation for targeting and blocking specific fibrogenic pathways, estimating the risk of fibrotic consequences, detecting early fibrotic alterations, and eventually allowing therapy development. Here, we first summarize the inflammatory and non-inflammatory components of fibrosis, and then we elaborate on the underlying mechanism associated with multiple cytokines in fibrosis, providing the framework for future clinical practice. Following that, we discuss the relationship between modernization and disease, as well as the shortcomings of current studies. We outline fibrosis diagnosis and therapy, as well as our recommendations for the future treatment of intestinal fibrosis. We anticipate that the global review will provides a wealth of fresh knowledge and suggestions for future fibrosis clinical practice.

Molecular docking analysis of natural compounds as TNF-α inhibitors for Crohn's disease management

Crohn's disease (CD) is a type of inflammatory bowel disease that is immune-mediated and affects the gastrointestinal tract. The chronic and severe nature of this condition leads to diminished health-related life quality, and frequent hospitalization. While medications such as sulfasalazine, corticosteroids, and immuno-suppressants are used to manage the condition, there are no definite treatments for pain and inflammation associated with CD. TNF-α is a prominent target, and medicines such as infliximab and adalimumab have pharmacological efficacy; however, they also have significant toxicity. Here, the natural compound library (2706 compounds) was screened against TNF-α to find natural TNF-α inhibitors to combat CD. The compounds namely ZINC5223934, ZINC6482465, ZINC4098633, ZINC1702729, and ZINC4649679 had higher binding affinity and interaction with the TNF-α protein than the positive control. Furthermore, these compounds had promising drug-like properties, indicating their potential for future exploration and optimization as TNF-α inhibitors for the treatment of CD.

Porphyromonas gingivalis-Helicobacter pylori co-incubation enhances Porphyromonas gingivalis virulence and increases migration of infected human oral keratinocytes

Background

Porphyromonas gingivalis is part of the subgingival biofilm and a keystone species in the development of periodontitis. Interactions between P.gingivalis and other bacteria in biofilms have been shown to affect bacterial virulence. Helicobacter pylori also inhabits the subgingival biofilm, but the consequences of interactions there with P.gingivalis remain unknown. Here, we investigated how the pre-incubation of P.gingivalis with H.pylori affects P.gingivalis virulence.

Methods

We assayed P.gingivalis internalization by oral keratinocytes (OKs), hemagglutination and biofilm formation to identify alterations in virulence after pre-incubation with H. pylori. Also, we evaluated viability and migration of OKs infected with P. gingivalis, as well as the role of toll-like receptor 4 (TLR4).   In addition, we quantified the mRNA of genes associated with P.gingivalis virulence.

Results

Pre-incubation of P.gingivalis with H.pylori enhanced P.gingivalis biofilm formation, bacterial internalization into OKs and hemagglutination. Infection with pre-incubated P.gingivalis increased OK migration in a manner dependent on the O-antigen and linked to  increased expression of the gingipain RgpB. Also, OK TLR4 participates in these events, because upon TLR4 knock-down, pre-incubated P.gingivalis no longer stimulated OK migration.

Discussion

We provide here for the first time insight to the consequences of direct interaction between P.gingivalis and H.pylori. In doing so, we shed light on the mechanism by which H. pylori presence in the oral cavity increases the severity or progression of periodontitis.

The Multiple Roles of CD147 in the Development and Progression of Oral Squamous Cell Carcinoma: An Overview

Cluster of differentiation (CD)147, also termed extracellular matrix metalloprotease inducer or basigin, is a glycoprotein ubiquitously expressed throughout the human body, the oral cavity included. CD147 actively participates in physiological tissue development or growth and has important roles in reactive processes such as inflammation, immunity, and tissue repair. It is worth noting that deregulated expression and/or activity of CD147 is observed in chronic inflammatory or degenerative diseases, as well as in neoplasms. Among the latter, oral squamous cell carcinoma (OSCC) is characterized by an upregulation of CD147 in both the neoplastic and normal cells constituting the tumor mass. Most interestingly, the expression and/or activity of CD147 gradually increase as healthy oral mucosa becomes inflamed; hyperplastic/dysplastic lesions are then set on, and, eventually, OSCC develops. Based on these findings, here we summarize published studies which evaluate whether CD147 could be employed as a marker to monitor OSCC development and progression. Moreover, we describe CD147-promoted cellular and molecular events which are relevant to oral carcinogenesis, with the aim to provide useful information for assessing whether CD147 may be the target of novel therapeutic approaches directed against OSCC.

Study on the Action Mechanism of Dkk-1, TGF-β1 and TNF-α Expression Levels in Dupuytren's Contracture

BACKGROUND

The biological mechanism of Dupuytren's contracture needs to be further studied in order to minimize postoperative recurrence and provide a pathological basis for the development of new therapeutic targets.

METHODS

HE staining, immunohistochemistry, PCR and western blotting were performed in pathological palmar aponeurosis specimens and normal palmar aponeurosis tissues for comparative study.

RESULTS

(1) TNF-α expression was up-regulated: TNF-α mRNA was more highly expressed in the pathological tissues of DD patients than in the CT group, P < 0.05, and the difference between the two groups was statistically significant; (2) Dkk-1 expression was down-regulated: Dkk-1 mRNA was lower expressed in the pathological tissues of DD patients than in the CT group, P < 0.05, and the difference between the two groups was statistically significant; (3) TGF-β1 expression was up-regulated: TGF-β1 mRNA was higher expressed in the pathological tissues of DD patients than in the CT group, P < 0.05, and the difference between the two groups was statistically significant; (4) Pearson correlation analysis suggested that TNF-α expression was positively correlated with TGF-β1 expression, TNF-α expression was negatively correlated with DKK-1 expression, and TGF-β1 expression was negatively correlated with DKK-1 expression.

CONCLUSION

TNF-α, DKK-1 and TGF-β1 may play a role in the pathogenesis of palmar aponeurosis contracture, and there is a relationship between them. The study of the relationship between the three and their related signaling pathways provides a therapeutic target and a basis for the prevention and early treatment of palmar aponeurotic contracture.

The Pathogenesis and Clinical Management of Stricturing Crohn Disease

Stricturing of the gastrointestinal tract is a common complication in Crohn disease and is a significant cause of morbidity and mortality among this population. The inflammatory process initiates fibrosis, leading to aberrant wound healing and excess deposition of extracellular matrix proteins. Our understanding of this process has grown and encompasses cellular mechanisms, epigenetic modifications, and inherent genetic predisposition toward fibrosis. Although medications can improve inflammation, there is still no drug to attenuate scar formation. As such, management of stricturing disease requires a multidisciplinary and individualized approach including medical management, therapeutic endoscopy, and surgery. This review details the current understanding regarding the pathogenesis, detection, and management of stricturing Crohn disease.

Upregulation of COX-2 and PGE2 Induced by TNF-α Mediated Through TNFR1/MitoROS/PKCα/P38 MAPK, JNK1/2/FoxO1 Cascade in Human Cardiac Fibroblasts

Purpose

Tumor necrosis factor-α (TNF-α) has been shown to exert as a pathogenic factor in cardiac fibrosis and heart failure which were associated with the up-regulation of cyclooxygenase (COX)-2/prostaglandin E₂ (PGE₂) axis. However, whether TNF-α-induced COX-2/PGE₂ upregulation mediated through ROS-dependent cascade remains elusive in human cardiac fibroblasts (HCFs). This study aims to address the underlying mechanisms of TNF-α-induced COX-2/PGE₂ expression.

Methods

Here, we used TNF receptor neutralizing antibody (TNFR nAb), pharmacologic inhibitors, and siRNAs to dissect the involvement of signaling components examined by Western blot and ELISA in TNF-α-mediated responses in HCFs. MitoSOX Red was used to measure mitoROS generation. Isolation of subcellular fractions was performed to determine membrane translocation of PKCα. Promoter luciferase assay and chromatin immunoprecipitation (ChIP) assay were used to determine the role of transcription factor.

Results

We found that TNF-α time- and concentration-dependently upregulated COX-2 protein and mRNA expression as well as PGE₂ synthesis which was attenuated by TNFR1 nAb, the inhibitor of mitochondrial ROS scavenger (MitoTEMPO), protein kinase C [(PKC)α, Gö6976], p38 MAPK [p38 inhibitor VIII, (p38i VIII)], JNK1/2 (SP600125), or forkhead box protein O1 [(FoxO1), AS1842856], and transfection with their respective siRNAs in HCFs. TNF-α-stimulated PKCα phosphorylation was inhibited by TNFR1 nAb, MitoTEMPO, or Gö6976. TNF-α stimulated phosphorylation of p38 MAPK and JNK1/2 was attenuated by TNFR1 nAb, MitoTEMPO, Gö6976, and their inhibitors p38i VIII and SP600125. Moreover, TNF-α-triggered FoxO1 phosphorylation was abolished by AS1842856, TNFR1 nAb, and its upstream inhibitors MitoTEMPO, Gö6976, p38i VIII, and SP600125. Phosphorylation of FoxO1 could enhance its interaction with the COX-2 promoter element revealed by ChIP assay, which was attenuated by AS1842856.

Conclusion

Our results suggested that TNF-α-induced COX-2/PGE₂ upregulation is mediated through TNFR1-dependent MitoROS/PKCα/p38 MAPK and JNK1/2 cascade to activate FoxO1 binding with the COX-2 promoter in HCFs.

Therapeutic candidates for keloid scars identified by qualitative review of scratch assay research for wound healing

The scratch assay is an in vitro technique used to analyze cell migration, proliferation, and cell-to-cell interaction. In the assay, cells are grown to confluence and then ‘scratched’ with a sterile instrument. For the cells in the leading edge, the resulting polarity induces migration and proliferation in attempt to ‘heal’ the modeled wound. Keloid scars are known to have an accelerated wound closure phenotype in the scratch assay, representing an overactivation of wound healing. We performed a qualitative review of the recent literature searching for inhibitors of scratch assay activity that were already available in topical formulations under the hypothesis that such compounds may offer therapeutic potential in keloid treatment. Although several shortcomings in the scratch assay literature were identified, caffeine and allicin successfully inhibited the scratch assay closure and inflammatory abnormalities in the commercially available keloid fibroblast cell line. Caffeine and allicin also impacted ATP production in keloid cells, most notably with inhibition of non-mitochondrial oxygen consumption. The traditional Chinese medicine, shikonin, was also successful in inhibiting scratch closure but displayed less dramatic impacts on metabolism. Together, our results partially summarize the strengths and limitations of current scratch assay literature and suggest clinical assessment of the therapeutic potential for these identified compounds against keloid scars may be warranted.

Assessment of the correlation between oxidative stress and expression of MMP-2, TIMP-1 and COX-2 in human aortic smooth muscle cells

INTRODUCTION

Smooth muscle cells (SMCs) are considered to be the main producer of matrix metalloproteinase-2 (MMP-2) participating primarily in extracellular matrix (ECM) remodeling. Any disturbances in ECM structure may underlie the pathogenesis of many cardiovascular diseases and contribute to angiogenesis, cancer development, invasion or metastasis. The purpose of the study was to examine the effect of oxidative stress on the expression of MMP-2, its tissue inhibitor type 1 (TIMP-1) and cyclooxygenase-2 (COX-2) in human aortic smooth muscle cells (HASMCs).

MATERIAL AND METHODS

HASMCs were treated with exogenously applied H₂O₂ or TNF-α. N-acetylcysteine (NAC) was used as an antioxidant. Gene expression levels were measured by real-time PCR and the protein levels were determined using ELISA assay.

RESULTS

The studies revealed no association between oxidative stress and either mRNA quantity or protein secretion of MMP-2 and TIMP-1. However, we found markedly reduced (p < 0.001) MMP-2 secretion in cells incubated with NAC. HASMCs stimulated with TNF-α demonstrated a significantly increased COX-2 mRNA level as well as enzyme activity. H₂O₂-induced cells showed lowered COX-2 activity in comparison to untreated cells. MMP-2 and TIMP-1 expression did not change after COX-2 inhibition with DuP-697.

CONCLUSIONS

We did not find any effect of oxidative stress on expression of MMP-2 and TIMP-1 in HASMCs. However, COX-2 mRNA and protein level were elevated in these conditions. There was no correlation between COX-2 activity and MMP-2 and TIMP-1 mRNA expression or protein secretion.

Integrative Bioinformatics Analysis Reveals Potential Target Genes and TNFα Signaling Inhibition by Brazilin in Metastatic Breast Cancer Cells

OBJECTIVE

Metastasis is the most significant cause of morbidity and mortality in breast cancer patients. Previously, a combination of brazilin and doxorubicin has been shown to inhibit metastasis in HER2-positive breast cancer cells. This present study used an integrative bioinformatics approach to identify new targets and the molecular mechanism of brazilin in inhibiting metastasis in breast cancer.

METHODS

Cytotoxicity and mRNA arrays data were retreived from the DTP website, whereas genes that regulate metastatic breast cancer cells were retreived from PubMed with keywords "breast cancer metastasis". Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and Drug association analysis were carried out by using WEB-based GEne SeT AnaLysis Toolkit (WebGestalt). Construction of protein-protein interaction (PPI) network analysis was performed by STRING-DB v11.0 and Cytoscape, respectively. The genetic alterations of the potential therapeutic target genes of brazilin (PB) were analyzed using cBioPortal.

RESULTS

Analysis of cytotoxicity with the public database of COMPARE showed that brazilin exerts almost the same cytotoxicity in the NCI-60 cells panel showing by similar GI50 value, in which the lowest GI50 value was observed in MDA-MB 231, a metastatic breast cancer cells. KEGG enrichment indicated several pathways regulated by brazilin such as TNF signaling pathway, cellular senescence, and pathways in cancer. We found ten drugs that are associated with PB, including protein kinase inhibitors, TNFα inhibitors, enzyme inhibitors, and anti-inflammatory agents.

CONCLUSION

In conclusion, this study identified eight PB, including MMP14, PTGS2, ADAM17, PTEN, CCL2, PIK3CB, MAP3K8, and CXCL3. In addition, brazilin possibly inhibits metastatic breast cancer through inhibition of TNFα signaling. The study results study need to be validated with in vitro and in vivo studies to strengthen scientific evidence of the use of brazilin in breast cancer metastasis inhibition.

Review: Local Tumor Necrosis Factor-α Inhibition in Inflammatory Bowel Disease

Crohn's disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases (IBD) characterized by intestinal inflammation. Increased intestinal levels of the proinflammatory cytokine tumor necrosis factor-α (TNF-α) are associated with disease activity and severity. Anti-TNF-α therapy is administered systemically and efficacious in the treatment of IBD. However, systemic exposure is associated with adverse events that may impede therapeutic treatment. Clinical studies show that the efficacy correlates with immunological effects localized in the gastrointestinal tract (GIT) as opposed to systemic effects. These data suggest that site-specific TNF-α inhibition in IBD may be efficacious with fewer expected side effects related to systemic exposure. We therefore reviewed the available literature that investigated the efficacy or feasibility of local TNF-α inhibition in IBD. A literature search was performed on PubMed with given search terms and strategy. Of 8739 hits, 48 citations were included in this review. These studies ranged from animal studies to randomized placebo-controlled clinical trials. In these studies, local anti-TNF-α therapy was achieved with antibodies, antisense oligonucleotides (ASO), small interfering RNA (siRNA), microRNA (miRNA) and genetically modified organisms. This narrative review summarizes and discusses these approaches in view of the clinical relevance of local TNF-α inhibition in IBD.

Fluorine-Modified Rutaecarpine Exerts Cyclooxygenase-2 Inhibition and Anti-inflammatory Effects in Lungs

Inflammation is the first step that leads to inflammatory cell migration, cytokine release, and myofibroblast formation. Myofibroblasts can deposit excess amounts of extracellular matrix. Cyclooxygenase (COX) inhibitor exhibits strong anti-inflammatory response; however, this is usually achieved with undesirable side effects. In this study, we demonstrated the effects of the fluorine-modified rutaecarpine (RUT), fluoro-2-methoxyrutaecarpine (F-RUT), in inflammatory damage in the lungs. Based on the results, F-RUT retained anti-inflammatory activity both in vitro and in vivo in lungs. Compared to the parent compound, F-RUT showed better COX-2 suppression as a COX-2-selective inhibitor with lower cytotoxicity, and enhanced molecular reactivity and biological activity. F-RUT was also observed to reduce reactive oxygen species (ROS) generation and inflammatory infiltrating neutrophils in lipopolysaccharide (LPS)-stimulated zebrafish and ovalbumin (OVA)/alum-challenged KLF-10-knockout mouse lungs, respectively. Furthermore, F-RUT ameliorated the respiratory function in OVA/alum-challenged BALB/c mice by maintaining the thickness of the blood-air barrier in mouse lungs. Overall, these data suggest that F-RUT may function as an effective therapeutic agent for inflammation-induced lung dysfunction, and a better selection for pharmaceutical purposes than conventionally used anti-inflammatory agents.

The Role of Heat Shock Proteins in Regulating Receptor Signal Transduction

Heat shock proteins (Hsp) are a class of stress-inducible proteins that mainly act as molecular protein chaperones. This chaperone activity is diverse, including assisting in nascent protein folding and regulating client protein location and translocation within the cell. The main proteins within the Hsp family, particularly Hsp70 and Hsp90, also have a highly diverse and numerous set of protein clients, which when combined with the high expression levels of Hsp proteins (2%-6% of total protein content) establishes these molecules as "central regulators" of cell protein physiology. Among the client proteins, Hsps regulate numerous signal-transduction and receptor-regulatory kinases, and indeed directly regulate some receptors themselves. This also makes the Hsps, particularly Hsp90, central regulators of signal-transduction machinery, with important impacts on endogenous and drug ligand responses. Among these roles, Hsp90 in particular acts to maintain mature signaling kinases in a metastable conformation permissive for signaling activation. In this review, we will focus on the roles of the Hsps, with a special focus on Hsp90, in regulating receptor signaling and subsequent physiologic responses. We will also explore potential means to manipulate Hsp function to improve receptor-targeted therapies. Overall, Hsps are important regulators of receptor signaling that are receiving increasing interest and exploration, particularly as Hsp90 inhibitors progress toward clinical approval for the treatment of cancer. Understanding the complex interplay of Hsp regulation of receptor signaling may provide important avenues to improve patient treatment.

Buckwheat and buckwheat enriched products exert an anti-inflammatory effect on the myofibroblasts of colon CCD-18Co

Buckwheat (BW) constitutes a good source of bioactive components that show anti-inflammatory effects in vitro and in vivo. The use of functional foods in the prevention and treatment of inflammatory bowel diseases (IBDs) has aroused increasing interest. This study investigates the effect of in vitro digested BW and BW-enriched products (BW-enriched wheat breads, roasted BW groats -fermented and non-fermented-, and BW sprouts) on colon myofibroblasts, the cells involved in the regulation of inflammatory response in the intestine. The cells were treated with different digested-BW products, alone or together with TNF-α (20 ng mL-1), and the effects on the cell migration, mitochondrial membrane potential and cell cycle, processes altered during intestinal inflammation, were investigated. A significant reduction in TNF-α-induced migration (25.5%, p < 0.05) and attenuation of the TNF-α-altered cell cycle (p < 0.05) was observed in myofibroblasts treated with BW-enriched white wheat bread. These results contribute to extend the beneficial effects derived from BW bioactive compounds, and suggest that BW consumption can exert beneficial effects on IBDs.

The role of kinins in the proliferation of fibroblast primed with TNF in scratch wound assay: Kinins and cell proliferation

The aim of this study was to evaluate the involvement of both B₁ and B₂ kinins receptors (B₁R and B₂R) in the fibroblast proliferation induced by the cytokine tumour necrosis factor (TNF) attempting to establish an in vitro model of wound healing. Murine fibroblasts L-929 were cultivated in 24 wells plaque until total confluence (DMEM (Vitrocell®); 5% fetal bovine serum, 5% CO₂, 37 °C) and then submitted to the scratch assay. The cells were treated with PBS, TNF (2 ng/mL) and/or mr-TNF antibody (200 μg/mL), or PDTC. The cells received the second set of treatment (3 h later): PBS; 1 μM HOE-140; 1 μM des-Arg⁹-Leu⁸-BK (DALBK) or 100 μM PDTC. TNF was able to increase the cell proliferation when compared with the group treated with PBS. The co-treatment with the TNF antibody completely reversed the TNF effect. The TNF-proliferative effect was blocked by B₁ (DALBK) and B₂ (HOE-140) kinin receptor antagonists administered separately or along, suggesting the involvement of both receptors in the TNF mechanism of action. Furthermore, the treatment with a NF-ĸB inhibitor PDTC completely blocked the cell proliferation. The TNF cell proliferation was incremented with BK (1 μM) treatment, and its effect was totally reversed by HOE-140 treatment. No effect was observed for TNF plus DABK. Eventually, TNF treatment was able to increase TNF level in the growing medium; however, this increase was suppressed by BK treatment. These results suggest that TNF induces cell proliferation and the induced signalling cascade has the B₂R participation. All these events seem to be totally dependent on the NF-ĸB activation. These inflammatory mediators can improve the wound healing in the resolution of inflammation.

Cytokine Receptor Profiling in Human Colonic Subepithelial Myofibroblasts: A Differential Effect of Th Polarization-Associated Cytokines in Intestinal Fibrosis

BACKGROUND

Colonic subepithelial myofibroblasts (cSEMFs) are mesenchymal cells with a pivotal role in the pathophysiology of Crohn's disease (CD) fibrosis. Here, we demonstrate for the first time a complete expression mapping of cytokine receptors, implicated in inflammatory bowel diseases, in primary human cSEMFs and how pro-inflammatory cytokines regulate this expression. Furthermore, we show the effect of Th1-, Th2-, Th17- and Treg-related cytokines on a fibrosis-related phenotype of cSEMFs.

METHODS

Colonic subepithelial myofibroblasts were isolated from healthy individuals' colonic biopsies. Interleukin (IL)-1α- and/or tumor necrosis factor (TNF)-α-induced mRNA and protein expression of cytokine receptors was assayed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunofluorescence, respectively. Th-related cytokine effects on mRNA and protein profibrotic factor expression were analyzed by qRT-PCR and/or colorimetric assays and on the wound-healing capacity of cSEMFs by scratch test.

RESULTS

In cSEMFs, we observed basal cytokine receptor expression, which was modified by IL-1α and TNF-α. Th1-related cytokines upregulated tissue factor (TF), collagen, fibronectin and matrix metalloproteinase (MMP)-1 and downregulated α-smooth muscle actin (α-SMA), MMP-9, and wound healing rate. Th2-related cytokines upregulated collagen, TF, α-SMA, MMP-1, and wound healing rate and downregulated fibronectin and MMP-9. IL-17 and IL-23 upregulated fibronectin, and IL-22 downregulated TF. IL-17 and IL-22 decreased wound healing rate. Similar to TGF-β, IL-23 upregulated MMP-1, tissue inhibitor of metalloproteinases-1, collagen expression, and wound healing rates.

CONCLUSIONS

Our results suggest that cSEMFs have a central role in inflammation and fibrosis, as they express a great variety of Th-related cytokine receptors, making them responsive to pro-inflammatory cytokines, abundant in the inflamed mucosa of CD patients.

IL-4 up-regulates cyclooxygenase-1 expression in macrophages

Macrophages use various cell-surface receptors to sense their environment and undergo polarized responses. The cytokines, interleukin (IL)-4 and IL-13, released from T-helper type 2 (Th2) cells, drive macrophage polarization toward an alternatively activated phenotype (M2). This phenotype is associated with the expression of potent pro-resolving mediators, such as the prostaglandin (PG) D₂-derived cyclopentenone metabolite, 15d-PGJ₂, produced by the cyclooxygenase (Ptgs; Cox) pathway. Interestingly, IL-4 treatment of bone marrow-derived macrophages (BMDMs) significantly down-regulates Cox-2 protein expression, whereas Cox-1 levels are significantly increased. This phenomenon not only challenges the dogma that Cox-1 is only developmentally regulated, but also demonstrates a novel mechanism in which IL-4-dependent regulation of Cox-1 involves the activation of the mechanistic target of rapamycin complex (mTORC). Using specific chemical inhibitors, we demonstrate here that IL-4-dependent Cox-1 up-regulation occurs at the post-transcriptional level via the Fes-Akt-mTORC axis. Activation of AMP-activated protein kinase (AMPK) by metformin, inhibition of mTORC by torin 1, or CRISPR/Cas9-mediated genetic knock-out of tuberous sclerosis complex-2 (Tsc2) blocked the IL-4-dependent expression of Cox-1 and the ability of macrophages to polarize to M2. However, use of 15d-PGJ₂ partially rescued the effects of AMPK activation, suggesting the importance of Cox-1 in macrophage polarization as also observed in a model of gastrointestinal helminth clearance. In summary, these findings suggest a new paradigm where IL-4-dependent up-regulation of Cox-1 expression may play a key role in tissue homeostasis and wound healing during Th2-mediated immune responses, such as parasitic infections.

Stromal and immune cells in gut fibrosis: the myofibroblast and the scarface

Post-inflammatory scarring is the end-result of excessive extracellular matrix (ECM) accumulation and tissue architectural destruction. It represents a failure to effectively remodel ECM and achieve proper reinstitution and healing during chronic relapsing inflammatory processes. Scarring may affect the functionality of any organ, and in the case of inflammatory bowel disease (IBD)-associated fibrosis leads to stricture formation and often surgery to remove the affected bowel. The activated myofibroblast is the final effector cell that overproduces ECM under the influence of various mediators generated by an intense interplay of classic and non-classic immune cells. This review focuses on how proinflammatory mediators from various sources produced in different stages of intestinal inflammation can form profibrotic pathways that eventually lead to tissue scarring through sustained activation of myofibroblasts.

Bradykinin stimulates protein kinase D-mediated colonic myofibroblast migration via cyclooxygenase-2 and heat shock protein 27

BACKGROUND

Inflammatory bowel disease is characterized by episodic intestinal injury and repair. Myofibroblasts are gastrointestinal tract stromal cells that regulate the reparative process and are known targets of inflammatory mediators including bradykinin (BK). However, the mechanisms through which inflammation regulates myofibroblast-induced wound healing remain incompletely understood. Here, we demonstrate, for the first time, that BK stimulates myofibroblast migration through protein kinase D (PKD)-mediated activation of the cyclooxygenase-2 (COX-2) and heat shock protein 27 (Hsp27) pathways.

MATERIALS AND METHODS

CCD-18Co is a human colonic myofibroblast cell line used from passages 8 to 14. An in vitro scratch assay assessed the effect of BK (100 nM) on myofibroblast migration over 24 h in the presence or absence of several inhibitors (CID755673 [10 μM] and NS398 [10 μM]). Hsp27 small interfering RNA evaluated the effect of Hsp27 on colonic myofibroblast migration. Antibodies to pPKD, pHsp27, and COX-2 evaluated expression levels by Western blot.

RESULTS

BK stimulated myofibroblast migration over 24 h. BK also led to rapid and sustained phosphorylation of PKD at Ser-916, rapid phosphorylation of Hsp27 at Ser-82, and increased COX-2 expression over 4 h. BK-mediated COX-2 expression and Hsp27 phosphorylation were both inhibited by the PKD inhibitor CID755673. Similarly, BK-induced myofibroblast migration was significantly inhibited by CID755673 (P < 0.05), by the direct COX-2 inhibitor NS398 (P < 0.05), and by Hsp27 small interfering RNA (P < 0.05).

CONCLUSIONS

BK stimulates myofibroblast migration through PKD-mediated activation of COX-2 and Hsp27. PKD, COX-2, and Hsp27 all appear to regulate myofibroblast cell migration, a stromal population that may play an important role in mucosal healing in the setting of inflammation.

ADAM17 in tumor associated leukocytes regulates inflammatory mediators and promotes mammary tumor formation

The presence of inflammatory cells within the tumor microenvironment has been tightly linked to mammary tumor formation and progression. Specifically, interactions between tumor cells and infiltrating macrophages can contribute to the generation of a pro-tumorigenic microenvironment. Understanding the complex mechanisms that drive tumor cell-macrophage cross-talk will ultimately lead to the development of approaches to prevent or treat early stage breast cancers. As described here, we demonstrate that the cell surface protease a disintegrin and metalloproteinase 17 (ADAM17) is expressed by macrophages in mammary tumors and contributes to regulating the expression of pro-inflammatory mediators, including inflammatory cytokines and the inflammatory mediator cyclooxygenase-2 (Cox-2). Furthermore, we demonstrate that ADAM17 is expressed on leukocytes, including macrophages, within polyoma middle T (PyMT)-derived mammary tumors. Genetic deletion of ADAM17 in leukocytes resulted in decreased onset of mammary tumor growth, which was associated with reduced expression of the Cox-2 within the tumor. These findings demonstrate that ADAM17 regulates key inflammatory mediators in macrophages and that leukocyte-specific ADAM17 is an important promoter of mammary tumor initiation. Understanding the mechanisms associated with early stage tumorigenesis has implications for the development of preventive and/or treatment strategies for early stage breast cancers.