IL-6/STAT3/TFF3 signaling regulates human biliary epithelial cell migration and wound healing in vitro

Intestinal Barrier Dysfunction and Gut Microbiota in Non-Alcoholic Fatty Liver Disease: Assessment, Mechanisms, and Therapeutic Considerations

Non-alcoholic fatty liver disease (NAFLD) is a type of metabolic stress liver injury closely related to insulin resistance (IR) and genetic susceptibility without alcohol consumption, which encompasses a spectrum of liver disorders ranging from simple hepatic lipid accumulation, known as steatosis, to the more severe form of steatohepatitis (NASH). NASH can progress to cirrhosis and hepatocellular carcinoma (HCC), posing significant health risks. As a multisystem disease, NAFLD is closely associated with systemic insulin resistance, central obesity, and metabolic disorders, which contribute to its pathogenesis and the development of extrahepatic complications, such as cardiovascular disease (CVD), type 2 diabetes mellitus, chronic kidney disease, and certain extrahepatic cancers. Recent evidence highlights the indispensable roles of intestinal barrier dysfunction and gut microbiota in the onset and progression of NAFLD/NASH. This review provides a comprehensive insight into the role of intestinal barrier dysfunction and gut microbiota in NAFLD, including intestinal barrier function and assessment, inflammatory factors, TLR4 signaling, and the gut-liver axis. Finally, we conclude with a discussion on the potential therapeutic strategies targeting gut permeability and gut microbiota in individuals with NAFLD/NASH, such as interventions with medications/probiotics, fecal transplantation (FMT), and modifications in lifestyle, including exercise and diet.

Co-Culture of P. gingivalis and F. nucleatum Synergistically Elevates IL-6 Expression via TLR4 Signaling in Oral Keratinocytes

Periodontitis, characterized by persistent inflammation in the periodontium, is intricately connected to systemic diseases, including oral cancer. Bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, play a pivotal role in periodontitis development because they contribute to dysbiosis and tissue destruction. Thus, comprehending the interplay between these bacteria and their impacts on inflammation holds significant relevance in clinical understanding and treatment advancement. In the present work, we explored, for the first time, their impacts on the expressions of pro-inflammatory mediators after infecting oral keratinocytes (OKs) with a co-culture of pre-incubated P. gingivalis and F. nucleatum. Our results show that the co-culture increases IL-1β, IL-8, and TNF-α expressions, synergistically augments IL-6, and translocates NF-kB to the cell nucleus. These changes in pro-inflammatory mediators-associated with chronic inflammation and cancer-correlate with an increase in cell migration following infection with the co-cultured bacteria or P. gingivalis alone. This effect depends on TLR4 because TLR4 knockdown notably impacts IL-6 expression and cell migration. Our study unveils, for the first time, crucial insights into the outcomes of their co-culture on virulence, unraveling the role of bacterial interactions in polymicrobial diseases and potential links to oral cancer.

Delayed recanalization reduced neuronal apoptosis and neurological deficits by enhancing liver-derived trefoil factor 3-mediated neuroprotection via LINGO2/EGFR/Src signaling pathway after middle cerebral artery occlusion in rats

Delayed recanalization at days or weeks beyond the therapeutic window was shown to improve functional outcomes in acute ischemic stroke (AIS) patients. However, the underlying mechanisms remain unclear. Previous preclinical study reported that trefoil factor 3 (TFF3) was secreted by liver after cerebral ischemia and acted a distant neuroprotective factor. Here, we investigated the liver-derived TFF3-mediated neuroprotective mechanism enhanced by delayed recanalization after AIS. A total of 327 male Sprague-Dawley rats and the model of middle cerebral artery occlusion (MCAO) with permanent occlusion (pMCAO) or with delayed recanalization at 3 d post-occlusion (rMCAO) were used. Partial hepatectomy was performed within 5 min after MCAO. Leucine-rich repeat and immunoglobulin-like domain-containing nogo receptor-interacting protein 2 (LINGO2) siRNA was administered intracerebroventricularly at 48 h after MCAO. Recombinant rat TFF3 (rr-TFF3, 30 μg/Kg) or recombinant rat epidermal growth factor (rr-EGF, 100 μg/Kg) was administered intranasally at 1 h after recanalization, and EGFR inhibitor Gefitinib (75 mg/Kg) was administered intranasally at 30 min before recanalization. The evaluation of outcomes included neurobehavior, ELISA, western blot and immunofluorescence staining. TFF3 in hepatocytes and serum were upregulated in a similar time-dependent manner after MCAO. Compared to pMCAO, delayed recanalization increased brain TFF3 levels and attenuated brain damage with the reduction in neuronal apoptosis, infarct volume and neurological deficits. Partial hepatectomy reduced TFF3 levels in serum and ipsilateral brain hemisphere, and abolished the benefits of delayed recanalization on neuronal apoptosis and neurobehavioral deficits in rMCAO rats. Intranasal rrTFF3 treatment reversed the changes associated with partial hepatectomy. Delayed recanalization after MCAO increased the co-immunoprecipitation of TFF3 and LINGO2, as well as expressions of p-EGFR, p-Src and Bcl-2 in the brain. LINGO2 siRNA knockdown or EGFR inhibitor reversed the effects of delayed recanalization on apoptosis and brain expressions of LINGO2, p-EGFR, p-Src and Bcl-2 in rMCAO rats. EGFR activator abolished the deleterious effects of LINGO2 siRNA. In conclusion, our investigation demonstrated for the first time that delayed recanalization may enhance the entry of liver-derived TFF3 into ischemic brain upon restoring blood flow after MCAO, which attenuated neuronal apoptosis and neurological deficits at least in part via activating LINGO2/EGFR/Src pathway.

JNKs protect from cholestatic liver disease progression by modulating Apelin signalling

Background & Aims

Cholestatic liver injury is associated with c-Jun N-terminal kinases (JNK) activation in distinct cell types. Its hepatocyte-specific function during cholestasis, however, has not yet been established. Therefore, in our present study, we investigated the role of JNK1/2 during cholestasis and dissected its hepatocyte-specific function.

Methods

A cohort of patients with primary biliary cholangitis (n = 29) and primary sclerosing cholangitis (n = 37) was examined. Wild-type, hepatocyte-specific knockout mice for Jnk2 (Jnk2Δhepa) or Jnk1 and Jnk2 (Jnk1Δhepa/2Δhepa) were generated. Mice were subjected to bile duct ligation (BDL) or carbon tetrachloride (CCl4) treatment. Finally, Apelin signalling was blocked using a specific inhibitor. As an interventional approach, Jnk1/2 were silenced in wild-type mice using lipid nanoparticles for small interfering RNA delivery.

Results

JNK activation was increased in liver specimens from patients with chronic cholestasis (primary biliary cholangitis and primary sclerosing cholangitis) and in livers of Mdr2-/- and BDL-treated animals. In Jnk1Δhepa/2Δhepa animals, serum transaminases increased after BDL, and liver histology demonstrated enhanced cell death, compensatory proliferation, hepatic fibrogenesis, and inflammation. Furthermore, microarray analysis revealed that hepatocytic Jnk1/2 ablation induces JNK-target genes involved in oxidative stress and Apelin signalling after BDL. Consequently, blocking Apelin signalling attenuated BDL-induced liver injury and fibrosis in Jnk1Δhepa/2Δhepa mice. Finally, we established an interventional small interfering RNA approach of selective Jnk1/2 targeting in hepatocytes in vivo, further demonstrating the essential protective role of Jnk1/2 during cholestasis.

Conclusions

Jnk1 and Jnk2 work together to protect hepatocytes from cholestatic liver disease by controlling Apelin signalling. Dual modification of JNK signalling in hepatocytes is feasible, and enhancing its expression might be an attractive therapeutic approach for cholestatic liver disease.

Impact and Implications

The cell-specific function of Jnk genes during cholestasis has not been explicitly explored. In this study, we showed that combined Jnk1/2, but not Jnk2 deficiency, in hepatocytes exacerbates liver damage and fibrosis by enhancing Apelin signalling, which contributes to cholestasis progression. Combined cell-specific Jnk targeting may be a new molecular strategy for treating cholestatic liver disease.

Intestinal activating transcription factor 4 regulates stress-related behavioral alterations via paraventricular thalamus in male mice

Chronic stress induces depression- and anxiety-related behaviors, which are common mental disorders accompanied not only by dysfunction of the brain but also of the intestine. Activating transcription factor 4 (ATF4) is a stress-induced gene, and we previously show that it is important for gut functions; however, the contribution of the intestinal ATF4 to stress-related behaviors is not known. Here, we show that chronic stress inhibits the expression of ATF4 in gut epithelial cells. ATF4 overexpression in the colon relieves stress-related behavioral alterations in male mice, as measured by open-field test, elevated plus-maze test, and tail suspension test, whereas intestine-specific ATF4 knockout induces stress-related behavioral alterations in male mice. Furthermore, glutamatergic neurons are inhibited in the paraventricular thalamus (PVT) of two strains of intestinal ATF4-deficient mice, and selective activation of these neurons alleviates stress-related behavioral alterations in intestinal ATF4-deficient mice. The highly expressed gut-secreted peptide trefoil factor 3 (TFF3) is chosen from RNA-Seq data from ATF4 deletion mice and demonstrated decreased in gut epithelial cells, which is directly regulated by ATF4. Injection of TFF3 reverses stress-related behaviors in ATF4 knockout mice, and the beneficial effects of TFF3 are blocked by inhibiting PVT glutamatergic neurons using DREADDs. In summary, this study demonstrates the function of ATF4 in the gut-brain regulation of stress-related behavioral alterations, via TFF3 modulating PVT neural activity. This research provides evidence of gut signals regulating stress-related behavioral alterations and identifies possible drug targets for the treatment of stress-related behavioral disorders.

A Pro-Regenerative Environment Triggers Premalignant to Malignant Transformation of Senescent Hepatocytes

Unfortunately, available liver cancer treatments are associated with modest survival advantage. The biggest factor improving survival is early detection, but the current understanding of early transformation events is limited. Therefore, we set up a model to study these early events and investigated the relationship of premalignant, senescent hepatocytes, a regenerative environment, and the influence of secreted factors on liver tumorigenesis. Oncogene-induced senescence (OIS) was triggered in a subset of mouse hepatocytes, which under normal conditions, are eliminated by immunosurveillance. Inducing liver damage and regeneration was sufficient to trigger immunosurveillance escape of OIS hepatocytes, resulting in premalignant to malignant transformation and hepatocellular tumor development. Trefoil factor 3 (TFF3) was found to be overexpressed in OIS hepatocytes and in hepatocellular carcinoma. TFF3 deficiency strongly attenuated malignant transformation by increasing insulin-like growth factor binding protein 5 (IGFBP5) expression, which consequently dampened IGF receptor signaling. Furthermore, analysis of precancerous liver tissue validated TFF3 as an early liver cancer biomarker. Altogether, these findings provide mechanistic insights into early transformation and immunosurveillance escape in liver cancer, revealing TFF3 and IGFBP5 to be important players with opposite roles in tumorigenesis.

SIGNIFICANCE

Liver damage induces a compensatory regenerative response that can drive premalignant to malignant transformation of senescent hepatocytes.

Trefoil factor 3: New highlights in chronic kidney disease research

Trefoil factor 3 (TFF3, also known as intestinal trefoil factor) is a small-molecule peptide containing a typical trefoil structure. TFF3 has several biological effects, such as wound healing, immune regulation, neuroprotection, and cell migration and proliferation promotion. Although TFF3 binding sites were identified in rat kidneys more than a decade ago, the specific effects of this small-molecule peptide on kidneys remain unclear. Until recently, much of the research on TFF3 in the kidney field has focused exclusively on its role as a biomarker. Notably, a large prospective randomized study of patients with 29 common clinical diseases revealed that chronic kidney disease (CKD) was associated with the highest serum TFF3 levels, which were 3-fold higher than in acute gastroenteritis, which had the second-highest levels. Examination of each stage of CKD revealed that urine and serum TFF3 levels significantly increased with the progression of CKD. These results suggest that the role of TFF3 in CKD needs further research. The present review summarizes the renal physiological expression, biological functions, and downstream signaling of TFF3, as well as the upstream events that lead to high expression of TFF3 in CKD.

Tff3 Deficiency Protects against Hepatic Fat Accumulation after Prolonged High-Fat Diet

Trefoil factor 3 (Tff3) protein is a small secretory protein expressed on various mucosal surfaces and is involved in proper mucosal function and recovery via various mechanisms, including immune response. However, Tff3 is also found in the bloodstream and in various other tissues, including the liver. Its complete attenuation was observed as the most prominent event in the early phase of diabetes in the polygenic Tally Ho mouse model of diabesity. Since then, its role in metabolic processes has emerged. To elucidate the complex role of Tff3, we used a new Tff3-deficient mouse model without additional metabolically relevant mutations (Tff3-/-/C57BL/6NCrl) and exposed it to a high-fat diet (HFD) for a prolonged period (8 months). The effect was observed in male and female mice compared to wild-type (WT) counter groups (n = 10 animals per group). We monitored the animals’ general metabolic parameters, liver morphology, ultrastructure and molecular genes in relevant lipid and inflammatory pathways. Tff3-deficient male mice had reduced body weight and better glucose utilization after 17 weeks of HFD, but longer HFD exposure (32 weeks) resulted in no such change. We found a strong reduction in lipid accumulation in male Tff3-/-/C57BL/6NCrl mice and a less prominent reduction in female mice. This was associated with downregulated peroxisome proliferator-activated receptor gamma (Pparγ) and upregulated interleukin-6 (Il-6) gene expression, although protein level difference did not reach statistical significance due to higher individual variations. Tff3-/-/C57Bl6N mice of both sex had reduced liver steatosis, without major fatty acid content perturbations. Our research shows that Tff3 protein is clearly involved in complex metabolic pathways. Tff3 deficiency in C57Bl6N genetic background caused reduced lipid accumulation in the liver; further research is needed to elucidate its precise role in metabolism-related events.

Augmented leptin-induced trefoil factor 3 expression and epidermal growth factor receptor transactivation differentially influences neoplasia progression in the stomach and colorectum of dietary fat-induced obese mice

Obesity is a risk factor for gastrointestinal malignancies and tumors. However, which factors either protect or predispose the gastrointestinal organs to high-fat diet (HFD)-induced neoplasia remains unclear. Here, we demonstrate that HFD impacts the stomach to a greater extent as compared to the colorectum, resulting in leptin receptor (LepR) signaling-mediated neoplasia in the tissues. HFD activated leptin signaling, which in turn, accelerates the pathogenesis in the gastric mucosa more than that in the colorectum along with ectopic TFF3 expression. Moreover, in the stomach, higher levels of phosphorylated epidermal growth factor receptor (EGFR) in addition to the activation of STAT3 and Akt were observed as compared to the colorectum. The mice with LepR deletion in the gastrointestinal epithelium exhibited a suppressed induction of leptin, TFF3, and phosphorylated EGFR in the stomach, whereas the levels in the colorectum were insignificant. In co-transfected COS-7 cells with LepR and EGFR plasmid DNA, leptin transactivated EGFR to accelerate TFF3 induction along with activation of STAT3, ERK1/2, Akt, and PI3K p85/p55. Furthermore, TFF3 could bind to EGFR but did not transactivate LepR. Leptin-induced TFF3 induction was markedly suppressed by inhibitors of PI3K (LY294002) and EGFR (Erlotinib). Together, these results suggest a novel role of LepR-mediated signaling in transactivating EGFR that leads to TFF3 expression via the PI3K-Akt pathway. Therefore, this study sheds light on the identification of potentially new therapeutic targets for the treatment of pre-cancerous symptoms in stomach and colorectum.

Infection by High-Risk Human Papillomaviruses, Epithelial-to-Mesenchymal Transition and Squamous Pre-Malignant or Malignant Lesions of the Uterine Cervix: A Series of Chained Events?

Wound healing requires static epithelial cells to gradually assume a mobile phenotype through a multi-step process termed epithelial-to-mesenchymal transition (EMT). Although it is inherently transient and reversible, EMT perdures and is abnormally activated when the epithelium is chronically exposed to pathogens: this event deeply alters the tissue and eventually contributes to the development of diseases. Among the many of them is uterine cervical squamous cell carcinoma (SCC), the most frequent malignancy of the female genital system. SCC, whose onset is associated with the persistent infection of the uterine cervix by high-risk human papillomaviruses (HR-HPVs), often relapses and/or metastasizes, being resistant to conventional chemo- or radiotherapy. Given that these fearsome clinical features may stem, at least in part, from the exacerbated and long-lasting EMT occurring in the HPV-infected cervix; here we have reviewed published studies concerning the impact that HPV oncoproteins, cellular tumor suppressors, regulators of gene expression, inflammatory cytokines or growth factors, and the interactions among these effectors have on EMT induction and cervical carcinogenesis. It is predictable and desirable that a broader comprehension of the role that EMT inducers play in SCC pathogenesis will provide indications to flourish new strategies directed against this aggressive tumor.

Transcriptome-Wide Analysis of Human Liver Reveals Age-Related Differences in the Expression of Select Functional Gene Clusters and Evidence for a PPP1R10-Governed 'Aging Cascade'

A transcriptome-wide analysis of human liver for demonstrating differences between young and old humans has not yet been performed. However, identifying major age-related alterations in hepatic gene expression may pinpoint ontogenetic shifts with important hepatic and systemic consequences, provide novel pharmacogenetic information, offer clues to efficiently counteract symptoms of old age, and improve the overarching understanding of individual decline. Next-generation sequencing (NGS) data analyzed by the Mann-Whitney nonparametric test and Ensemble Feature Selection (EFS) bioinformatics identified 44 transcripts among 60,617 total and 19,986 protein-encoding transcripts that significantly (p = 0.0003 to 0.0464) and strikingly (EFS score > 0.3:16 transcripts; EFS score > 0.2:28 transcripts) differ between young and old livers. Most of these age-related transcripts were assigned to the categories 'regulome', 'inflammaging', 'regeneration', and 'pharmacogenes'. NGS results were confirmed by quantitative real-time polymerase chain reaction. Our results have important implications for the areas of ontogeny/aging and the age-dependent increase in major liver diseases. Finally, we present a broadly substantiated and testable hypothesis on a genetically governed 'aging cascade', wherein PPP1R10 acts as a putative ontogenetic master regulator, prominently flanked by IGFALS and DUSP1. This transcriptome-wide analysis of human liver offers potential clues towards developing safer and improved therapeutic interventions against major liver diseases and increased insights into key mechanisms underlying aging.

Hepatic cell mobilization for protection against ischemic myocardial injury

The heart is capable of activating protective mechanisms in response to ischemic injury to support myocardial survival and performance. These mechanisms have been recognized primarily in the ischemic heart, involving paracrine signaling processes. Here, we report a distant cardioprotective mechanism involving hepatic cell mobilization to the ischemic myocardium in response to experimental myocardial ischemia–reperfusion (MI-R) injury. A parabiotic mouse model was generated by surgical skin-union of two mice and used to induce bilateral MI-R injury with unilateral hepatectomy, establishing concurrent gain- and loss-of-hepatic cell mobilization conditions. Hepatic cells, identified based on the cell-specific expression of enhanced YFP, were found in the ischemic myocardium of parabiotic mice with intact liver (0.2 ± 0.1%, 1.1 ± 0.3%, 2.7 ± 0.6, and 0.7 ± 0.4% at 1, 3, 5, and 10 days, respectively, in reference to the total cell nuclei), but not significantly in the ischemic myocardium of parabiotic mice with hepatectomy (0 ± 0%, 0.1 ± 0.1%, 0.3 ± 0.2%, and 0.08 ± 0.08% at the same time points). The mobilized hepatic cells were able to express and release trefoil factor 3 (TFF3), a protein mitigating MI-R injury as demonstrated in TFF3^−/− mice (myocardium infarcts 17.6 ± 2.3%, 20.7 ± 2.6%, and 15.3 ± 3.8% at 1, 5, and 10 days, respectively) in reference to wildtype mice (11.7 ± 1.9%, 13.8 ± 2.3%, and 11.0 ± 1.8% at the same time points). These observations suggest that MI-R injury can induce hepatic cell mobilization to support myocardial survival by releasing TFF3.

Investigation of Fascin1, a Marker of Mature Dendritic Cells, Reveals a New Role for IL-6 Signaling in CCR7-Mediated Chemotaxis

Migration of mature dendritic cells (DCs) to lymph nodes is critical for the initiation of adaptive immunity. CCR7, a G-protein-coupled receptor for CCL19/21 chemokines, is known to be essential for chemotaxis of mature DCs, but the molecular mechanism linking inflammation to chemotaxis remains unclear. We previously demonstrated that fascin1, an actin-bundling protein, increases chemotaxis of mature mouse DCs. In this article, we demonstrated that fascin1 enhanced IL-6 secretion and signaling of mature mouse DCs. Furthermore, we demonstrated that IL-6 signaling is required for chemotaxis. Blockage of IL-6 signaling in wild-type DCs with an anti-IL-6 receptor α (IL-6Rα) Ab inhibited chemotaxis toward CCL19. Likewise, knockout of IL-6Rα inhibited chemotaxis of bone marrow-derived DCs. The addition of soluble IL-6Rα and IL-6 rescued chemotaxis of IL-6Rα knockout bone marrow-derived DCs, underscoring the role of IL-6 signaling in chemotaxis. We found that IL-6 signaling is required for internalization of CCR7, the initial step of CCR7 recycling. CCR7 recycling is essential for CCR7-mediated chemotaxis, explaining why IL-6 signaling is required for chemotaxis of mature DCs. Our results have identified IL-6 signaling as a new regulatory pathway for CCR7/CCL19-mediated chemotaxis and suggest that rapid migration of mature DCs to lymph nodes depends on inflammation-associated IL-6 signaling.

MC-LR-induced interaction between M2 macrophage and biliary epithelial cell promotes biliary epithelial cell proliferation and migration through regulating STAT3

Microcystin-leucine-arginine (MC-LR) was produced by toxic cyanobacteria, which has been shown to have potent hepatotoxicity. Our previous study has proved that MC-LR were able to promote intrahepatic biliary epithelial cell excessive proliferation. However, the underlying mechanism is not yet entirely clarified. Herein, mice were fed with different concentrations (1, 7.5, 15, or 30 μg/L) of MC-LR by drinking water for 6 months. As the concentration of MC-LR increased, a growing number of macrophages were evaluated in the portal area of the mouse liver. Next, we built a co-culture system to explore the interaction between macrophages (THP-1 cells) and human intrahepatic biliary epithelial cells (HiBECs) in the presence of MC-LR. Under the exposure of MC-LR, HiBECs secreted a large amount of inflammatory factors (IL-6, IL-8, IL-1β, COX-2, XCL-1) and chemokine (MCP-1), which produced a huge chemotactic effect on THP-1 cells and induced elevation of the surface M2-subtype biomarkers (IL-10, CD163, CCL22, and Arg-1). In turn, high content of IL-6 in the medium activated JAK2/STAT3, MEK/ERK, and PI3K/AKT pathways in HiBECs, inducing HiBEC abnormal proliferation and migration. Together, these results suggested that MC-LR-mediated interaction between HiBECs and macrophages induced the M2-type polarization of macrophages, and activated IL-6/JAK2/STAT3, MEK/ERK, and PI3K/AKT pathways in HiBECs, further enhanced cell proliferation, improved cell migration, and hindered cell apoptosis by activating p-STAT3. MC-LR stimulates HiBECs to produce various inflammatory factors, recruiting a large number of macrophages and promoting the differentiation of macrophages into M2-type. In turn, the M2 macrophages could also produce amounts of IL-6 and activate STAT3 through JAK2/STAT3, MEK/ERK, and PI3K/AKT pathways in HiBECs, resulting in the promotion of cell proliferation, inhibition of apoptosis, and enhancement of migration.

Extracellular production of recombinant sus scrofa trefoil factor 3 by Brevibacillus choshinensis

Trefoil factor 3 (TFF3) is involved in cell adhesion, motility and apoptosis, regulates mucosal immunity and maintains the functional integrity of intestinal epithelia. The upregulation of TFF3 expression in the weaning rat intestine attracted our interest. The present study hypothesized that TFF3 may serve a role in preventing diarrhea in weaning piglets, which is an important consideration in the pig farming industry. Previous recombinant TFF3 protein expression yields obtained from Escherichia coli were too low and the bioactivity of the protein was poor. Hence, this expression system was unsuitable for industrial applications. The present study explored the production of recombinant sus scrofa TFF3 in a Brevibacillus choshinensis (B. choshinensis) expression system, aiming to enhance the expression level of bioactive protein. To achieve this, the sus scrofa TFF3-encoding gene fragment was fused into an E. coli-Brevibacillus shuttle vector pNCMO2. High levels of TFF3 (30 mg/l) were produced and secreted into the B. choshinensis culture medium in soluble form with a molecular mass of 13.6 kDa and high immunoreactivity in western blotting. Thus, Brevibacillus may be used to produce useful mucosal factors for biochemical analyses and mucosal protection, and in industrial applications to produce novel inhibitors of diarrhea.

Positive role of calcium phosphate ceramics regulated inflammation in the osteogenic differentiation of mesenchymal stem cells

Recently, researches have confirmed the crucial role of inflammatory response in Ca-P ceramic-induced osteogenesis, however, the underlying mechanism has not yet been fully understood. In this study, BCP and β-TCP ceramics were used as material models to investigate the effect of physicochemical properties on inflammatory response in vitro. The results showed that BCP and β-TCP could support macrophages attachment, proliferation, and spreading favorably, as well as promote gene expressions of inflammatory related cytokines (IL-1, IL-6, MCP-1, and TNF-α) and growth factors (TGF-β, FGF, PDGF, VEGF, IGF, and EGF). BCP showed a facilitating function on the gene expressions earlier than β-TCP. Further coculture experiments performed in vitro demonstrated that the CMs containing various increased cytokines for macrophages pre-culture could significantly promote MSCs osteogenic differentiation, which was confirmed by the gene expressions of osteogenic specific markers and the intracellular OCN product accumulation under the stimulation of BCP and β-TCP ceramics. Further evidence was found from the formation of mineralized nodules in BCM and TCM. In addition, this study showed a concise relationship between Ca-P ceramic induced inflammation and its osteoinductivity that the increased cytokines and growth factors from macrophages could promote MSCs osteogenic differentiation.

Differential Expression of TFF1 and TFF3 in Patients Suffering from Chronic Rhinosinusitis with Nasal Polyposis

Trefoil family factor (TFF) proteins contribute to antimicrobial defense and the maintenance of sinonasal epithelial barrier integrity. Dysregulation of TFF expression may be involved in the development of chronic inflammation and tissue remodeling characteristically found in chronic rhinosinusitis with nasal polyposis (CRSwNP). Expressions of TFF1 and TFF3 were determined in specimens of middle nasal turbinate (MNT-0), bulla ethmoidalis (BE), and nasal polyps (NP) from CRSwNP patients (n = 29) and inferior nasal turbinate from a group of control patients (underwent nasal septoplasty, n = 25). An additional MNT sample was collected 6 months after functional endoscopic sinus surgery (FESS, MNT-6). TFF1 mRNA levels were significantly reduced in all specimens by approximately three- to five-fold, while TFF3 was increased in MNT-0, as compared with controls. Six months after surgery their levels were reversed to control values. CRSwNP patients with S. epidermidis isolated from sinus swabs showed upregulation of TFF3 in MNT and NP as compared with patients with sterile swabs. Target gene regulation was not affected by the presence of type 2 inflammation in patients with confirmed allergy. Results of this study imply participation of TFFs genes in the development of CRSwNP.

TFF3 interacts with LINGO2 to regulate EGFR activation for protection against colitis and gastrointestinal helminths

Intestinal epithelial cells (IEC) have important functions in nutrient absorption, barrier integrity, regeneration, pathogen-sensing, and mucus secretion. Goblet cells are a specialized cell type of IEC that secrete Trefoil factor 3 (TFF3) to regulate mucus viscosity and wound healing, but whether TFF3-responsiveness requires a receptor is unclear. Here, we show that leucine rich repeat receptor and nogo-interacting protein 2 (LINGO2) is essential for TFF3-mediated functions. LINGO2 immunoprecipitates with TFF3, co-localizes with TFF3 on the cell membrane of IEC, and allows TFF3 to block apoptosis. We further show that TFF3-LINGO2 interactions disrupt EGFR-LINGO2 complexes resulting in enhanced EGFR signaling. Excessive basal EGFR activation in Lingo2 deficient mice increases disease severity during colitis and augments immunity against helminth infection. Conversely, TFF3 deficiency reduces helminth immunity. Thus, TFF3-LINGO2 interactions de-repress inhibitory LINGO2-EGFR complexes, allowing TFF3 to drive wound healing and immunity.

Down-regulated circPAPPA suppresses the proliferation and invasion of trophoblast cells via the miR-384/STAT3 pathway

Preeclampsia (PE) is the main cause of maternal death in primipara, and commonly results in severe maternal and neonatal complications such as multiple organ dysfunction syndrome. However, the exact pathogenesis of this disease remains unclear. Circular RNAs (circRNAs) are noncoding RNAs that have been shown to be extensively involved in numerous physiological processes, but there is limited knowledge of their functions and mechanisms in PE. In the present study, we found the expression of a circRNA, hsa_circ_0088227 (circRNA of pregnancy-associated plasma protein A, circPAPPA), was down-regulated in both placenta and plasma samples from subjects with PE. Knockdown of circPAPPA led to decreased proliferation and invasion in HTR8-S/Vneo trophoblast cells. miR-384 was identified as a direct target of circPAPPA, and the gene encoding signal transducer and activator of transcription 3 (STAT3) was targeted by miR-384. We found that miR-384 was unregulated in PE, and overexpression of miR-384 could inhibit cell proliferation and invasion. In addition, we showed that the expression of STAT3 was decreased with knockdown of circPAPPA or the overexpression of miR-384 in trophoblast cells, but this decrease was partially reversed when co-transfection was performed with mimics of miR-384 inhibitor and si-circPAPPA. Together, these results suggest that down-regulation of circPAPPA facilitates the onset and development of PE by suppressing trophoblast cells, with involvement of the miR-384/STAT3 signaling pathway. Our study significantly increases the understanding of the occurrence and development of PE, and also provides a molecular target for the treatment of this disorder.

High throughput silencing identifies novel genes in endometrioid endometrial cancer

OBJECTIVE

To validate the gene expression profile obtained from the previous microarray analysis and to further study the biological functions of these genes in endometrial cancer. From our previous study, we identified 621 differentially expressed genes in laser-captured microdissected endometrioid endometrial cancer as compared to normal endometrial cells. Among these genes, 146 were significantly up-regulated in endometrial cancer.

MATERIALS AND METHODS

A total of 20 genes were selected from the list of up-regulated genes for the validation assay. The qPCR confirmed that 19 out of the 20 genes were up-regulated in endometrial cancer compared with normal endometrium. RNA interference (RNAi) was used to knockdown the expression of the upregulated genes in ECC-1 and HEC-1A endometrial cancer cell lines and its effect on proliferation, migration and invasion were examined.

RESULTS

Knockdown of MIF, SOD2, HIF1A and SLC7A5 by RNAi significantly decreased the proliferation of ECC-1 cells (p < 0.05). Our results also showed that the knockdown of MIF, SOD2 and SLC7A5 by RNAi significantly decreased the proliferation and migration abilities of HEC-1A cells (p < 0.05). Moreover, the knockdown of SLC38A1 and HIF1A by RNAi resulted in a significant decrease in the proliferation of HEC1A cells (p < 0.05).

CONCLUSION

We have identified the biological roles of SLC38A1, MIF, SOD2, HIF1A and SLC7A5 in endometrial cancer, which opens up the possibility of using the RNAi silencing approach to design therapeutic strategies for treatment of endometrial cancer.

Desmoplastic Tumor Microenvironment and Immunotherapy in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a dismal disease which often is diagnosed at a late stage where the tumor is locally advanced, metastatic, and, as a result, is associated with low resectability. The heterogeneity of this cancer type is a major reason why the majority of patients fail to respond to therapy, and surgery remains their only curative option. Among patients who undergo surgical intervention, such tumors typically recur in 50% of cases within 1year. Thus, CCA is among the most aggressive and chemoresistant malignancies. CCA is characterized by marked tumor reactive stroma, a fibrogenic connective tissue which surrounds and infiltrates the tumor epithelium. This desmoplastic environment presents a clinical challenge, limiting drug delivery and supporting the growth of the tumor mass. In this review we attempt to highlight key pathways involved in cell to cell communication between the tumor epithelium and stroma, the immune components, and opportunities for novel strategies to improve patient outcome.

Polyriboinosinic-polyribocytidylic acid facilitates interleukin-6, and interleukin-8 secretion in human dermal fibroblasts via the JAK/STAT3 and p38 MAPK signal transduction pathways

Polyriboinosinic-polyribocytidylic acid (polyI:C) is a viral dsRNA analoguethat promotes wounds healing, accelerates re-epithelialization, granulation and neovascularization, and induces pro-inflammatory cytokine release. Little is known about polyI:C mediated induction of inflammatory mediators in human dermal fibroblast (HDFs), which form the primary scaffold for epithelial cells covering the wound. Here, we found that polyI:C enhances IL-6 and IL-8 mRNA expression and induces of IL-6 and IL-8 production in a concentration-dependent and time-dependent manner in HDFs. PolyI:C treatment rapidly increased phosphorylation level of both STAT3 and p38 mitogen-activated protein kinase (MAPK). Moreover, pretreatment with AG490, a Janus kinase (JAK) inhibitor, inhibited polyI:C-induced STAT3 phosphorylation and subsequent IL-6 and IL-8 release. Conversely, pretreatment with SB203580, a selective inhibitor of p38 MAPK, blocked p38 MAPK phosphorylation and IL-6 and IL-8 expression. In conclusion, polyI:C induces IL-6 and IL-8 production in HDFs via the JAK/STAT3 and p38 MAPK signaling pathways.

Overexpression of trefoil factor 3 (TFF3) contributes to the malignant progression in cervical cancer cells

Background

There remains a great need for effective therapies for cervical cancers, the majority of which are aggressive leaving patients with poor prognosis.

Methods and results

Here, we identify a novel candidate therapeutic target, trefoil factor 3 (TFF3) which overexpressed in cervical cancer cells and was associated with reduced postoperative survival. Functional studies demonstrated that TFF3 overexpression promoted the proliferation and invasion of cervical cancer cells, and inhibited the apoptosis by inducing the mRNA changes in SiHa and Hela cell lines. Conversely, TFF3 silencing disrupted the proliferation and invasion of cervical cancer cells, and induced the apoptosis via Click-iT EdU test, flow cytometry analysis and two-dimensional Matrigel Transwell analysis. Western blot analysis showed that overexpression of TFF3 repressed E-cadherin (CDH1) expression to promote the invasion of cervical cancer cells. Furthermore, down-regulated CDH1 via overexpression of TFF3 was significantly up-regulated by virtue of inhibitor of p-STAT3.

Conclusions

These results suggested that TFF3 stimulated the invasion of cervical cancer cells probably by activating the STAT3/CDH1 signaling pathway. Furthermore, overexpression of TFF3 decreased the sensitivity of cervical cancer cells to etoposide by increasing P-glycoprotein (P-gp) functional activity. Overall, our work provides a preclinical proof that TFF3 not only contributes to the malignant progression of cervical cancers and but also is a potential therapeutic target.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-016-0379-1) contains supplementary material, which is available to authorized users.

The Blockade of IL6 Counterparts the Osmolar Stress-Induced Apoptosis in Human Conjunctival Epithelial Cells

To determine the effect of hyperosmolarity on cell survival/apoptosis of conjunctival epithelial cells and evaluate the possible role of IL6, Wong-Kilbourne derivative of Chang conjunctival cell line (WKD) was used in this study. Confluent cells were incubated under different osmolarity (290 mOsm and 500 mOsm) with or without neutralizing IL6 antibody (50 ng/mL). The expression of IL6 level was measured in the supernatant of each conditioned medium. Cell viability/apoptosis assay was performed using Annexin V/Propidium Iodide (PI) and Cell Counting Kit-8 (CCK-8). Western blot was conducted to measure the abundance of apoptotic markers and IL6 related downstream signaling pathway. The concentration of IL6 showed time-dependent increase in cells treated with 500 mOsm. Although apoptosis of WKD cell is increased in treated 500 mOsm for 24 h, apoptosis reduced in WKD cell treated 500 mOsm with anti-IL6 for 24 h. Anti-IL6 inhibited the activation of JAK-STAT signaling pathway, which was induced by hyperosmolarity. Hyperosmolar condition induced apoptosis in conjunctival epithelial cells, along with increase of IL6 production. IL6 neutralizing antibody inhibited apoptosis and JAK-STAT signaling in hyperosmolar condition. These findings suggested that IL6 may be involved in apoptotic change and in hyperosmolarity.

Nuclear Factor Erythroid 2-Related Factor 2 Deficiency Results in Amplification of the Liver Fat-Lowering Effect of Estrogen

Transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) regulates multiple biologic processes, including hepatic lipid metabolism. Estrogen exerts actions affecting energy homeostasis, including a liver fat-lowering effect. Increasing evidence indicates the crosstalk between these two molecules. The aim of this study was to evaluate whether Nrf2 modulates estrogen signaling in hepatic lipid metabolism. Nonalcoholic fatty liver disease (NAFLD) was induced in wild-type and Nrf2-null mice fed a high-fat diet and the liver fat-lowering effect of exogenous estrogen was subsequently assessed. We found that exogenous estrogen eliminated 49% and 90% of hepatic triglycerides in wild-type and Nrf2-null mice with NAFLD, respectively. This observation demonstrates that Nrf2 signaling is antagonistic to estrogen signaling in hepatic fat metabolism; thus, Nrf2 absence results in striking amplification of the liver fat-lowering effect of estrogen. In addition, we found the association of trefoil factor 3 and fatty acid binding protein 5 with the liver fat-lowering effect of estrogen. In summary, we identified Nrf2 as a novel and potent inhibitor of estrogen signaling in hepatic lipid metabolism. Our finding may provide a potential strategy to treat NAFLD by dually targeting Nrf2 and estrogen signaling.

Delayed wound healing and dysregulation of IL6/STAT3 signalling in MSCs derived from pre-diabetic obese mice

Metabolic dysfunction that occurs in obesity and Type 2 diabetes results in a low-level inflammatory state which impacts on mesenchymal stem cells (MSCs) capacity to promote wound healing. The ability of either recombinant Interleukin-6 (rIL6) or pioglitazone to modulate MSC migration, essential for wound healing, by targeting the inflammation-modulated IL6/STAT3 signalling pathway was therefore investigated in bone marrow-derived MSCs from control (C57BL/6J) and pre-diabetic obese mice (B6. Cg-Lepob/J). The population doubling time, in vitro wound closure and mRNA expression profile of 84 genes involved in the IL6/STAT3 signalling pathway were assessed. IL6/STAT3 signalling dysregulation, caused by IL6 deficiency, resulted in skewing of the immune modulatory properties of MSCs to favour a pro-inflammatory profile. This could be nullified by addition of either rIL6 or conventional diabetes treatment. Therapies to improve diabetic wound healing should therefore focus on the cellular changes induced by the pathological inflammatory micro-environment.

Interleukin‑6 induces epithelial‑mesenchymal transition in human intrahepatic biliary epithelial cells

The aim of the present study was to determine the role of interleukin-6 (IL-6) in the epithelial-mesenchymal transition (EMT) of human intrahepatic biliary epithelial cell (HIBEC) lines in vitro. HIBECs were stimulated with IL-6 at concentrations of 0, 10, 20, 50 and 100 µg/l for 24 h. A wound healing and Transwell assay were performed to determine the migratory and invasive capacity of HIBECs, respectively. Following 24 h of incubation, IL-6 at 10 and 20 µg/l significantly increased the number of migrated and invaded cells (P<0.05), while stimulation with 50 and 100 µg/l IL-6 resulted in a further increase of the migratory and invasive capacity compared to that in all other groups (P<0.05). Furthermore, reverse-transcription quantitative polymerase chain reaction and western blot analyses were used to detect the mRNA and protein expression of EMT markers E-cadherin and vimentin in HIBECs. Decreased mRNA levels of E-cadherin accompanied by higher mRNA levels of vimentin were observed in the 10, 20, 50, 100 µg/l IL-6 groups compared to those in the 0 µg/l group (all P<0.05). Furthermore, the protein expression of E-cadherin was decreased, while that of vimentin was increased in the 50 and 100 µg/l IL-6 groups compared to those in the 0, 10 and 20 µg/l IL-6 groups (all P<0.05). The present study therefore indicated that IL-6 promoted the process of EMT in HIBECs as characterized by increased migration and invasion of HIBECs and the typical changes in mRNA and protein expression of the EMT markers E-cadherin and vimentin.

Corticotropin-Releasing Hormone Receptor 2 Signaling Promotes Mucosal Repair Responses after Colitis

The corticotropin-releasing hormone family mediates functional responses in many organs, including the intestine. Activation of corticotropin-releasing hormone receptor 2 (CRHR2) in the colonic mucosa promotes inflammation during acute colitis but inhibits inflammation during chronic colitis. We hypothesized that specific modulation of CRHR2 signaling in the colonic mucosa can promote restoration of the epithelium through stimulation of cell proliferative, migratory, and wound healing responses. Mucosal repair was assessed after dextran sodium sulfate (DSS)-induced colitis in mice receiving intracolonic injections of a CRHR2 antagonist or vehicle and in Crhr2(-/-) mice. Histologic damage, cytokine expression, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling, and Ki-67 immunoreactivity were evaluated. Cell viability, proliferation, and migration were compared between parental and CRHR2-overexpressing colonic epithelial cells. Protein lysates were processed for phosphoprotein assays and a wound healing assay performed in vitro. Administration of a CRHR2 antagonist after DSS-induced colitis increased disease activity, delayed healing, and decreased epithelial cell proliferation in vivo. Colons from these mice also showed increased apoptosis and proinflammatory cytokine expression. Compared with controls, Crhr2(-/-) mice showed increased mortality in the DSS healing protocol. CRHR2-overexpressing cells had increased proliferation and migration compared with parental cells. Wound healing and signal transducer and activator of transcription 3 activity were elevated in CRHR2-overexpressing cells after urocortin 2 and IL-6 treatment, suggesting advanced healing progression. Our results suggest that selective CRHR2 activation may provide a targeted approach to enhance mucosal repair pathways after colitis.

The Prognostic Role of SOCS3 and A20 in Human Cholangiocarcinoma

As an antagonist of the JAK/STAT pathway, suppressor of cytokine signaling 3 (SOCS3) plays an integral role in shaping the inflammatory environment, tumorigenesis and disease progression in cholangiocarcinoma (CCA); however, its prognostic significance remains unclear. Although tumor necrosis factor α-induced protein 3 (TNFAIP3, also known as A20) can decrease SOCS3 expression and is involved in the regulation of tumorigenesis in certain malignancies, its role in CCA remains unknown. In this study, we investigated the expression of SOCS3 and A20 in human CCA tissues to assess the prognostic significance of these proteins. The expression of SOCS3 and A20 was initially detected by western blot in 22 cases of freshly frozen CCA tumors with corresponding peritumoral tissues and 22 control normal bile duct tissues. Then, these proteins were investigated in 86 CCA patients by immunohistochemistry (IHC) and were evaluated for their association with clinicopathological parameters in human CCA. The results indicated that SOCS3 expression was significantly lower in CCA tumor tissues than in corresponding peritumoral biliary tissues and normal bile duct tissues. Conversely, A20 was overexpressed in CCA tissues. Thus, an inverse correlation between the expression of SOCS3 and A20 was discovered. Furthermore, patients with low SOCS3 expression or high A20 expression showed a dramatically lower overall survival rate. These proteins were both associated with CCA lymph node metastasis, postoperative recurrence and overall survival rate. However, only A20 showed a significant association with the tumor node metastasis (TNM) stage, while SOCS3 showed a significant association with tumor differentiation. Multivariate Cox analysis revealed that SOCS3 and A20 were independent prognostic indicators for overall survival in CCA. Thus, our study demonstrated that SOCS3 and A20 represent novel prognostic factors for human CCA.

Trefoil factors: Gastrointestinal-specific proteins associated with gastric cancer

Trefoil factor family (TFF), composed of TFF1, TFF2, and TFF3, is a cluster of secreted peptides characterized by trefoil domain (s) and C-terminal dimerization domain. TFF1, a gastric tumor suppressor, is a single trefoil peptide originally detected in breast cancer cell lines but expressed mainly in the stomach; TFF2, a candidate of gastric cancer suppressor with two trefoil domains, is abundant in the stomach and duodenal Brunner's glands; and TFF3 is another single trefoil peptide expressed throughout the intestine which can promote the development of gastric carcinoma. According to multiple studies, TFFs play a regulatory function in the mammals' digestive system, namely in mucosal protection and epithelial cell reconstruction, tumor suppression or promotion, signal transduction and the regulation of proliferation and apoptosis. Action mechanisms of TFFs remain unresolved, but the recent demonstration of a GKN (gastrokine) 2-TFF1 heterodimer implicates structural and functional interplay with gastrokines. This review aims to encapsulate the structural and biological characteristics of TFF.

Trefoil Factor 3 (TFF3) Is Regulated by Food Intake, Improves Glucose Tolerance and Induces Mucinous Metaplasia

Trefoil factor 3 (TFF3), also called intestinal trefoil factor or Itf, is a 59 amino acid peptide found as a homodimer predominantly along the gastrointestinal tract and in serum. TFF3 expression is elevated during gastrointestinal adenoma progression and has been shown to promote mucosal wound healing. Here we show that in contrast to other trefoil factor family members, TFF1 and TFF2, TFF3 is highly expressed in mouse duodenum, jejunum and ileum and that its expression is regulated by food intake. Overexpression of TFF3 using a recombinant adeno-associated virus (AAV) vector, or daily administration of recombinant TFF3 protein in vivo improved glucose tolerance in a diet-induced obesity mouse model. Body weight, fasting insulin, triglyceride, cholesterol and leptin levels were not affected by TFF3 treatment. Induction of mucinous metaplasia was observed in mice with AAV-mediated TFF3 overexpression, however, no such adverse histological effect was seen after the administration of recombinant TFF3 protein. Altogether these results suggest that the therapeutic potential of targeting TFF3 to treat T2D may be limited.

Enhanced expression of suppresser of cytokine signaling 3 inhibits the IL-6-induced epithelial-to-mesenchymal transition and cholangiocarcinoma cell metastasis

It was recently demonstrated that interleukin-6 (IL-6) induces the epithelial-to-mesenchymal transition (EMT) in cholangiocarcinoma (CCA), but the underlying molecular mechanism remains to be explored. In this study, we studied the role of suppresser of cytokine signaling 3 (SOCS3), a negative feedback regulator of IL-6/STAT3, in the IL-6-induced EMT in CCA. Treatment with IL-6 induced the EMT by decreasing the E-cadherin expression and increasing the expression of N-cadherin and vimentin. Using wound healing and invasion assays, we found that IL-6 promoted cell motility. Further, a stably transfected cell line overexpressing SOCS3 was constructed. Enhanced SOCS3 expression decreased IL-6-induced cell invasion and EMT in parallel with downregulating the IL-6/STAT3 pathway. In contrast, SOCS3 silencing using siRNA exhibited no effect on the cell invasive ability and EMT. Finally, an in vivo study indicated that the enhancement of SOCS3 expression decreased metastasis compared with the control, and this effect was achieved by the repression of p-STAT3, N-cadherin and vimentin, and the induction of E-cadherin assessed by Western blot analysis. Our results suggest that enhanced expression of SOCS3 can antagonize IL-6-induced EMT and cell metastasis by abrogating the IL-6/STAT3 pathway. These data establish that SOCS3 plays a role in the EMT in CCA and may provide novel therapeutic strategies for CCA.

Synergistic effect of interleukin-6 and hyaluronic acid on cell migration and ERK activation in human keratinocytes

Wound healing is initiated and progressed by complex integrated process of cellular, physiologic, and biochemical events, such as inflammation, cell migration and proliferation. Interleukin 6 (IL-6) is a multifunctional cytokine, and it could regulate the inflammatory response of wound healing process in a timely manner. Hyaluronic acid (HA) is an essential component of the extracellular matrix, and contributes significantly to cell proliferation and migration. The purpose of this study was to investigate the effects of IL-6 or/and HA on the cell migration process in human keratinocytes. Combining IL-6 and HA significantly increased the cell migration in scratch based wound healing assay. The phosphorylation of extracellular-signal-regulated kinase (ERK) was significantly increased after 1 hr of IL-6 and HA treatment, but the phosphorylation of p38 mitogen-activated protein kinase (MAPK) was not. We also found that significant increase of the NF-κB translocation from cytoplasm into nucleus after 1 hr of IL-6 or/and HA treatments. This study firstly showed that synergistic effects of combining IL-6 and HA on the cell migration of wound healing by activation of ERK and NF-κB signaling. Further studies might be required to confirm the synergistic effects of HA and IL-6 in the animal model for the development of a novel therapeutic mixture for stimulation of wound healing process.

Tissue-engineered endometrial model for the study of cell-cell interactions

Endometrial stromal and epithelial cell cross talk is known to influence many of the dynamic changes that occur during the menstrual cycle. We modified our previous model and embedded telomerase-immortalized human endometrial stromal cells and Ishikawa adenocarcinoma epithelial cells in a collagen-Matrigel hydrogel to create a tissue-engineered model of the endometrium. Comparisons of single and cocultured cells examined communication between endometrial stromal and epithelial cells, which were cultured with 0 or 10 nmol/L 17β estradiol; conditioned medium was used to look at the production of paracrine factors. Using this model, we were able to identify the changes in interleukin 6 (IL-6) and active matrix metalloproteinase 2, which appear to be due to paracrine signaling and differences in transforming growth factor β1 (TGF-β1) that do not appear to be due to paracrine signaling. Moreover, IL-6, TGF-β1, and DNA content were also affected by the presence of estradiol in many of the tissues. These results indicate that paracrine and endocrine signaling are involved in human endometrial responses and support the use of coculture models to further investigate cell-cell and cell-matrix interactions.

A mutually beneficial relationship between hepatocytes and cardiomyocytes mitigates doxorubicin-induced toxicity

Use of doxorubicin (DOX) is limited by its toxicity in multiple organs. However, the relationship between different organs in response to DOX-induced injury is not well understood. We found that partial hepatectomy correlated with increased DOX-induced heart injury in vivo while supernatant prepared from DOX-treated hepatocytes mitigated DOX-induced cytotoxicity of cardiomyocytes in vitro. Meanwhile, the supernatant of DOX-treated cardiomyocytes mitigated DOX-induced cytotoxicity of hepatocytes. Investigation of the molecular mechanisms underlying these effects found that interleukin 6 (IL-6) was significantly up-regulated in DOX-treated tissues and cells, and supernatant from IL-6 treated cells had a similar effect to that from DOX-treated cells. Although the concentration of secreted IL-6 in supernatant from DOX-treated cells did not significantly differ, blockade of IL-6 signaling, by overexpressing SOCS3, suppressed expression of the downstream molecules trefoil factor family 3 (TFF3) and hepatocyte growth factor (HGF), impaired the mutually beneficial relationship between hepatocytes and cardiomyocytes. In conclusion, our study shows that a mutually beneficial relationship exists between hepatocytes and cardiomyocytes during the acute injury induced by DOX. Moreover, it demonstrates that this phenomenon may be indirectly caused by increased IL-6 expression and the activation of the downstream molecular mediators TFF3 and HGF in hepatocytes and cardiomyocytes, respectively.

HLA-G regulates the invasive properties of JEG-3 choriocarcinoma cells by controlling STAT3 activation

The expression of human leucocyte antigen-G (HLA-G) in trophoblasts plays a crucial role in successful embryonic implantation, and reduced HLA-G expression might contribute to adverse obstetric outcomes. In this study, we silenced HLA-G expression using RNA interference in JEG-3 cells, resulting in a notably attenuated invasion capacity of the cells in a Transwell assay; however, no alterations in cell proliferation or apoptosis were observed. The down-regulation of HLA-G dampened the activation of signal transducer and activator of transcription 3 (STAT3), whereas the up-regulation of HLA-G promoted STAT3 activation and invasion in JEG-3 cells treated with human galectin-1. Most importantly, interleukin-6 (IL-6), but not galectin-1, was shown to rescue invasion deficiency in a dose-dependent manner. Thus, we demonstrate that HLA-G is able to regulate JEG-3 cell invasion by influencing STAT3 activation, which may underlie the implantation defects accompanying HLA-G hypo-expression in pre-eclampsia.

Trefoil factor 3 peptide regulates migration via a Twist-dependent pathway in gastric cell

Trefoil factor 3 (TFF3) is a member of the TFF-domain peptide family and essential in regulating cell migration and maintaining mucosal integrity in gastrointestinal tract. However, the role of TFF3 and its downstream regulating mechanisms in cancer cell migration remain unclear. We previously reported that TFF3 prolonged the up-regulation of Twist protein to modulate IL-8 secretion in intestinal epithelial cells. In this study, we investigated the role of Twist protein in TFF3-induced migration of SGC7901 cells. While Twist was activated by TFF3, siRNA-mediated knockdown of Twist abolished TFF3-induced cell migration. Furthermore, the migration related marker CK-8 as well as ZO-1 and MMP-9 was also regulated by TFF3 via a Twist-dependent mechanism. Our study suggests that Twist, as an important potential downstream effector, plays a key role in TFF3-modulated metastasis in gastric cancer and can be a promising therapeutic target against intestinal-type gastric cancer.

Danger control programs cause tissue injury and remodeling

Are there common pathways underlying the broad spectrum of tissue pathologies that develop upon injuries and from subsequent tissue remodeling? Here, we explain the pathophysiological impact of a set of evolutionary conserved danger control programs for tissue pathology. These programs date back to the survival benefits of the first multicellular organisms upon traumatic injuries by launching a series of danger control responses, i.e., 1. Haemostasis, or clotting to control bleeding; 2. Host defense, to control pathogen entry and spreading; 3. Re-epithelialisation, to recover barrier functions; and 4. Mesenchymal, to repair to regain tissue stability. Taking kidney pathology as an example, we discuss how clotting, inflammation, epithelial healing, and fibrosis/sclerosis determine the spectrum of kidney pathology, especially when they are insufficiently activated or present in an overshooting and deregulated manner. Understanding the evolutionary benefits of these response programs may refine the search for novel therapeutic targets to limit organ dysfunction in acute injuries and in progressive chronic tissue remodeling.

IL-6 augmented motility of airway epithelial cell BEAS-2B via Akt/GSK-3β signaling pathway

Cell migration plays a pivotal role in airway repair and remodeling involved in respiratory diseases such as asthma. Interleukin-6 (IL-6) and fascin-1 are involved in cell migration upon stimulation; however, the roles of IL-6 and fascin-1 in migration of airway epithelial cell remain sketchy. The present study was aimed to investigate influence of IL-6 on cell motility with emphasis on the association with fascin-1. Wound healing assay and transmigration assay were performed to examine effect of IL-6 on migration and invasiveness of human bronchial epithelial cell BEAS-2B. Level of mRNA expression was determined by RT-PCR and quantitative real-time RT-PCR (Q-PCR). Involvement of kinase and transcription factor signaling in IL-6-induced cell migration was investigated using immunoblot and specific inhibitors. IL-6 significantly augmented cell migration and invasiveness in parallel with elevated fascin-1 expression. Further investigation showed that IL-6 dose-dependently upregulated fascin-1 expression in both mRNA and protein levels. We showed that IL-6 activated Akt and inhibited glycogen synthase kinase-3β (GSK-3β), highly associating with fascin-1 mRNA expression. Additionally, IL-6-induced migration was significantly diminished by phosphatidyl inositol 3-phosphate kinase (PI3K) inhibitor (wortamannin) and β-catenin inhibitor FH535. Moreover, LiCl and SB216763, inhibitors of GSK-3β augmented cell migration as well as fascin-1 mRNA expression. Conclusively, these findings reveal that IL-6-induced migration of BEAS-2B cell may be attributed to activation of Akt, inhibition of GSK-3β, and the associated increase of β-catenin and fascin-1 expression, indicating an important role of Akt/GSK-3β signaling and β-catenin/fascin-1 in IL-6 associated airway remodeling.

Advances in cholangiocyte immunobiology

Cholangiocytes, or bile duct epithelia, were once thought to be the simple lining of the conduit system comprising the intra- and extrahepatic bile ducts. Growing experimental evidence demonstrated that cholangiocytes are in fact the first line of defense of the biliary system against foreign substances. Experimental advances in recent years have unveiled previously unknown roles of cholangiocytes in both innate and adaptive immune responses. Cholangiocytes can release inflammatory modulators in a regulated fashion. Moreover, they express specialized pattern-recognizing molecules that identify microbial components and activate intracellular signaling cascades leading to a variety of downstream responses. The cytokines secreted by cholangiocytes, in conjunction with the adhesion molecules expressed on their surface, play a role in recruitment, localization, and modulation of immune responses in the liver and biliary tract. Cholangiocyte survival and function is further modulated by cytokines and inflammatory mediators secreted by immune cells and cholangiocytes themselves. Because cholangiocytes act as professional APCs via expression of major histocompatibility complex antigens and secrete antimicrobial peptides in bile, their role in response to biliary infection is critical. Finally, because cholangiocytes release mediators critical to myofibroblastic differentiation of portal fibroblasts and hepatic stellate cells, cholangiocytes may be essential in the pathogenesis of biliary cirrhosis.

Four danger response programs determine glomerular and tubulointerstitial kidney pathology: clotting, inflammation, epithelial and mesenchymal healing

Renal biopsies commonly display tissue remodeling with a combination of many different findings. In contrast to trauma, kidney remodeling largely results from intrinsic responses, but why? Distinct danger response programs were positively selected throughout evolution to survive traumatic injuries and to regenerate tissue defects. These are: (1) clotting to avoid major bleeding, (2) immunity to control infection, (3) epithelial repair and (4) mesenchymal repair. Collateral damages are acceptable for the sake of host survival but causes for kidney injury commonly affect the kidneys in a diffuse manner. This way, coagulation, inflammation, deregulated epithelial healing or fibrosis contribute to kidney remodeling. Here, I focus on how these ancient danger response programs determine renal pathology mainly because they develop in a deregulated manner, either as insufficient or overshooting processes that modulate each other. From a therapeutic point of view, immunopathology can be prevented by suppressing sterile renal inflammation, a useless atavism with devastating consequences. In addition, it appears as an important goal for the future to promote podocyte and tubular epithelial cell repair, potentially by stimulating the differentiation of their newly discovered intrarenal progenitor cells. By contrast, it is still unclear whether selectively targeting renal fibrogenesis can preserve or bring back lost renal parenchyma, which would be required to maintain or improve kidney function. Thus, renal pathology results from ancient danger responses that evolved because of their evolutional benefits upon trauma. Understanding these causalities may help to shape the search for novel treatments for kidney disease patients.

A forward loop between glioma and microglia: glioma-derived extracellular matrix-activated microglia secrete IL-18 to enhance the migration of glioma cells

The mediators and cellular effectors of inflammation are important constituents of the local environment of tumors. In some occasions, oncogenic changes induce an inflammatory microenvironment that promotes the progression of tumors. In gliomas, the presence of microglia may represent tumor-related inflammation and microglia activation, and subsequent inflammatory responses may influence tumor growth and metastasis. Here, we found that C6 glioma--but not primary astrocyte-derived extracellular matrix (ECM) could activate microglia, including primary microglia and BV-2 cell line, and activated microglia-secreted interleukin (IL)-18, a potent inflammatory cytokine of the IL-1 family, to promote C6 migration. In addition, by coating purified ECM components, it was found that secretion of IL-18 by activated microglia was enhanced when microglia encountered with fibronectin and vitronectin. Furthermore, IL-18-induced C6 migration and microfilament disassembly were antagonized by iNOS inhibitor, guanylate cyclase inhibitor, and protein kinase G inhibitor. Taken together, these results indicate that IL-18 secreted by microglia, which was activated by C6 glioma-derived ECM, enhanced migration of C6 glioma through NO/cGMP pathway.

Luteolin suppresses growth and migration of human lung cancer cells

Luteolin, 3',4',5,7-tetrahydroxyflavone, has been shown to possess antioxidant, anti-inflammation and anti-cancer properties. However, its role in lung cancer remains poorly understood. Here we examined the anti-tumorigenic role of luteolin in a commonly used lung cancer cell line. Luteolin inhibited the growth of A549 cells by inducing G1 phase cell cycle arrest and apoptosis. Furthermore, stress fiber assembly and cell migration in A549 cells was markedly suppressed by luteolin.