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

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.

Advances of Heat Shock Family in Ulcerative Colitis

Ulcerative Colitis (UC) is a non-specific and chronic inflammatory disease of colonic mucosa whose exact etiology and mechanisms remain unclear. The incidence rate of UC is increasing year by year worldwide. What followed is that the medical costs are also rising rapidly. Therefore, it is urgent to understand the pathogenesis and find promising therapeutic targets for UC. Intestinal mucosal homeostasis is essential for normal bowel function, and its imbalance may be an important pathogenesis of UC. Endogenous homeostatic regulators play roles in repairing intestinal mucosa injury after stress. Heat shock family proteins are essential endogenous homeostasis factors. They can inhibit inflammation, regulate intestinal epithelial cells’ survival and death, and promote mucosal healing. Thus, they play important roles in sustaining intestinal mucosal homeostasis and protecting against UC progression. However, the heat shock family may promote UC carcinogenesis. Here, we summarize the advances in the research of the functions of the heat shock family in UC. And this review is an attempt to light on the etiopathogenesis of UC, highlighting the endogenous protective mechanisms, hoping to provide a novel therapeutic target for UC treatment.

A modular map of Bradykinin-mediated inflammatory signaling network

Bradykinin, a member of the kallikrein-kinin system (KKS), is associated with an inflammatory response pathway with diverse vascular permeability functions, including thrombosis and blood coagulation. In majority, bradykinin signals through Bradykinin Receptor B2 (B2R). B2R is a G protein-coupled receptor (GPCR) coupled to G protein family such as Gα_qs, Gα_q/Gα_11, Gα_i1, and Gβ1_γ2_. B2R stimulation leads to the activation of a signaling cascade of downstream molecules such as phospholipases, protein kinase C, Ras/Raf-1/MAPK, and PI3K/AKT and secondary messengers such as inositol-1,4,5-trisphosphate, diacylglycerol and Ca²⁺ ions. These secondary messengers modulate the production of nitric oxide or prostaglandins. Bradykinin-mediated signaling is implicated in inflammation, chronic pain, vasculopathy, neuropathy, obesity, diabetes, and cancer. Despite the biomedical importance of bradykinin, a resource of bradykinin-mediated signaling pathway is currently not available. Here, we developed a pathway resource of signaling events mediated by bradykinin. By employing data mining strategies in the published literature, we describe an integrated pathway reaction map of bradykinin consisting of 233 reactions. Bradykinin signaling pathway events included 25 enzyme catalysis reactions, 12 translocations, 83 activation/inhibition reactions, 11 molecular associations, 45 protein expression and 57 gene regulation events. The pathway map is made publicly available on the WikiPathways Database with the ID URL: https://www.wikipathways.org/index.php/Pathway:WP5132. The bradykinin-mediated signaling pathway map will facilitate the identification of novel candidates as therapeutic targets for diseases associated with dysregulated bradykinin signaling.

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.

T-cadherin inhibits invasion and migration of endometrial stromal cells in endometriosis

STUDY QUESTION

What is the expression level of T-cadherin in endometriosis, and does T-cadherin play a role in regulating invasion and migration of endometrial stromal cells?

SUMMARY ANSWER

T-cadherin expression was reduced in ectopic endometriotic lesions compared to eutopic endometrium, and T-cadherin overexpression inhibited the invasion and migration of endometrial stromal cells.

WHAT IS KNOWN ALREADY

Endometriosis is a disease that involves active cell invasion and migration. T-cadherin can inhibit cell invasion, migration and proliferation in various cancer cells, but its role in endometriosis has not been investigated.

STUDY DESIGN, SIZE, DURATION

We explored the expression status of T-cadherin in 40 patients with and 24 without endometriosis. We also isolated endometrial stromal cells to study the invasion, migration and signaling pathway regulation of T-cadherin overexpression.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients were recruited at the Guangzhou Women and Children's Medical Center to study the expression levels of T-cadherin. The expression of T-cadherin was detected by immunohistochemistry staining and western blot. H-score was used to evaluate the staining intensity of T-cadherin. The correlation between T-cadherin expression levels (H-score) and endometriosis patients' age, stage, lesion size and adhesion was analyzed. Endometrial stromal cells from patients with and without endometriosis were isolated, and cell invasion and migration were detected by transwell assays after T-cadherin overexpression. The expression of vimentin in T-cadherin-overexpressed cells was detected by western blot. After T-cadherin overexpression, the phosphorylation profile of signaling pathway proteins was detected with the Proteome Profiler Human Phospho-Kinase Array Kit.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no difference in the expression of T-cadherin in the normal endometrium of control patients and the eutopic endometrium of endometriotic patients, but it was significantly decreased in the ectopic endometrium of endometriotic patients, compared with control endometrium and eutopic endometrium of endometriosis patients (P < 0.0001, for both). Western blot analysis also showed that the expression of T-cadherin was decreased in ectopic endometriotic lesions, but not the normal control endometrium or the endometriotic eutopic endometrium. The results of transwell assays indicated that T-cadherin overexpression inhibited the invasion and migration of endometrial stromal cells. In addition, T-cadherin overexpression promoted the phosphorylation of HSP27 (S78/S82) and JNK 1/2/3 (T183/Y185, T221/Y223) and decreased the expression of vimentin, MMP2 and MMP9 in eutopic endometriosis stromal cells.

LARGE-SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

The control group were patients with benign gynecological conditions (e.g. uterus myoma, endometrial or cervical polyp), which may have genetic or epigenetic variations associated with T-cadherin expression and signaling pathways. The case numbers of involved endometriosis and control patients were limited. This study only used endometrial stromal cells from patients with or without endometriosis. Ideally, ectopic endometrial stromal cells of the ovarian endometriotic lesions should also be utilized to explore the function of T-cadherin.

WIDER IMPLICATIONS OF THE FINDINGS

Further investigation of the role of T-cadherin in endometriosis may generate new potential therapeutic targets for this complex disorder.

STUDY FUNDING AND COMPETING INTEREST(S)

This study was supported by the Natural Science Foundation of Guangdong Province (2016A030313495), National Natural Science Foundation of China (81702567, 81671406, 31871412), the Science and Technology Programs of Guangdong (2017A050501021), Medical Science Technology Research Fund of Guangdong Province (A2018075), the Science and Technology Programs of Guangzhou City (201704030103), Internal Project of Family Planning Research Institute of Guangdong Province (S2018004), Post-doc initiation fund of Guangzhou (3302) and Post-doc science research initiation fund of Guangzhou Women and Children's Medical Center (20160322). There are no conflicts of interest.

Multifaceted Functions of Protein Kinase D in Pathological Processes and Human Diseases

Protein kinase D (PKD) is a family of serine/threonine protein kinases operating in the signaling network of the second messenger diacylglycerol. The three family members, PKD1, PKD2, and PKD3, are activated by a variety of extracellular stimuli and transduce cell signals affecting many aspects of basic cell functions including secretion, migration, proliferation, survival, angiogenesis, and immune response. Dysregulation of PKD in expression and activity has been detected in many human diseases. Further loss- or gain-of-function studies at cellular levels and in animal models provide strong support for crucial roles of PKD in many pathological conditions, including cancer, metabolic disorders, cardiac diseases, central nervous system disorders, inflammatory diseases, and immune dysregulation. Complexity in enzymatic regulation and function is evident as PKD isoforms may act differently in different biological systems and disease models, and understanding the molecular mechanisms underlying these differences and their biological significance in vivo is essential for the development of safer and more effective PKD-targeted therapies. In this review, to provide a global understanding of PKD function, we present an overview of the PKD family in several major human diseases with more focus on cancer-associated biological processes.

Heat shock transcription factor 2 predicts mucosal healing and promotes mucosal repair of ulcerative colitis

Background: Mucosal healing(MH) is a treatment goal in ulcerative colitis (UC). Our previous studies showed heat shock transcription factor 2 (HSF2) was positively correlated with the activity of UC and had anti-inflammatory potential in DSS-induced colitis, but the role of HSF2 in MH remains unknown. This study aimed to reveal the predictive value and mechanisms of HSF2 in the MH of UC.Methods: Fecal samples were collected from 51 UC patients and 10 healthy controls. Correlation analyses among HSF2, fecal calprotectin(FC) and Mayo endoscopic subscore(MES) were conducted by Pearson correlation coefficient. Diagnostic accuracy and cutoffs to predict MH were analyzed by ROC curves. 231 UC patients were enrolled to verify the diagnostic validity of the cutoffs. HSF2 siRNA and HSF2-FLAG recombinant plasmids were transfected into HT-29 cells. IL-1β, TNF-α and TGF-β levels in supernatants were determined by ELISA. The expression and phosphorylation levels of MAPKs and Smad2/3 were detected by Western blotting.Results: Positive correlations existed between HSF2 and MES (r = 0.81), FC and MES (r = 0.85), and HSF2 and FC (r = 0.91). Optimal cutoffs of HSF2 was 1.97 ng/ml (AUC 0.919) and that of FC was 678 µg/g (AUC 0.958). HSF2 and FC achieved high sensitivity (73.7% vs 84.2%) and negative predictive value (89.1% vs 93.9%). HSF2 decreased IL-1β and TNF-α secretion via suppression of MAPK signaling pathway activation. HSF2 promoted the expression of TGF-β via increasing phosphorylation of Smad2/3.Conclusions: HSF2 may be a predictor of MH in UC patients. HSF2 inhibited inflammation and promoted mucosal repair.

Regulation of Osteoclast Differentiation at Multiple Stages by Protein Kinase D Family Kinases

Balanced osteoclast and osteoblast activity is necessary for skeletal health, whereas unbalanced osteoclast activity causes bone loss in many skeletal conditions. A better understanding of pathways that regulate osteoclast differentiation and activity is necessary for the development of new therapies to better manage bone resorption. The roles of Protein Kinase D (PKD) family of serine/threonine kinases in osteoclasts have not been well characterized. In this study we use immunofluorescence analysis to reveal that PKD2 and PKD3, the isoforms expressed in osteoclasts, are found in the nucleus and cytoplasm, the mitotic spindle and midbody, and in association with the actin belt. We show that PKD inhibitors CRT0066101 and CID755673 inhibit several distinct aspects of osteoclast formation. Treating bone marrow macrophages with lower doses of the PKD inhibitors had little effect on M-CSF + RANKL-dependent induction into committed osteoclast precursors, but inhibited their motility and subsequent differentiation into multinucleated mature osteoclasts, whereas higher doses of the PKD inhibitors induced apoptosis of the preosteoclasts. Treating post-fusion multinucleated osteoclasts with the inhibitors disrupted the osteoclast actin belts and impaired their resorptive activity. In conclusion, these data implicate PKD kinases as positive regulators of osteoclasts, which are essential for multiple distinct processes throughout their formation and function.

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 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.

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.