Intestinal trefoil factor/TFF3 promotes re-epithelialization of corneal wounds

A Novel Ferroptosis Inhibitor UAMC-3203, a Potential Treatment for Corneal Epithelial Wound

Corneal wound, associated with pain, impaired vision, and even blindness, is the most common ocular injury. In this study, we investigated the effect of a novel ferroptosis inhibitor, UAMC-3203 (10 nM-50 µM), in corneal epithelial wound healing in vitro in human corneal epithelial (HCE) cells and ex vivo using alkali-induced corneal wounded mice eye model. We evaluated in vivo acute tolerability of the compound by visual inspection, optical coherence tomography (OCT), and stereomicroscope imaging in rats after its application (100 µM drug solution in phosphate buffer pH 7.4) twice a day for 5 days. In addition, we studied the partitioning of UAMC-3203 in corneal epithelium and corneal stroma using excised porcine cornea. Our study demonstrated that UAMC-3203 had a positive corneal epithelial wound healing effect at the optimal concentration of 10 nM (IC₅₀ value for ferroptosis) in vitro and at 10 µM in the ex vivo study. UAMC-3203 solution (100 µM) was well tolerated after topical administration with no signs of toxicity and inflammation in rats. Ex-vivo distribution study revealed significantly higher concentration (~12-38-fold) and partition coefficient (K_p) (~52 times) in corneal epithelium than corneal stroma. The UAMC-3203 solution (100 µM) was stable for up to 30 days at 4 °C, 37 °C, and room temperature. Overall, UAMC-3203 provides a new prospect for safe and effective therapy for corneal wounds.

Tear proteomics analysis of patient suffered from delayed mustard gas keratopathy

Understanding the molecular and cellular mechanisms involved in the pathogenesis of ocular injured induced by mustard gas can help better identify complications and discover appropriate therapies. This study aimed to analyze the proteomics of tears of chemical warfare victims with mustard gas ocular injuries and compare it with healthy individuals. In this case-control research, 10 mustard gas victims with long-term ocular difficulties (Chronic) were included in the patient group, while 10 healthy persons who were age and sex matched to the patients were included in the control group. Schirmer strips were used to collect the tears of the participants. Proteomics experiments were performed using the high-efficiency TMT10X method to evaluate the tear protein profile, and statistical bioinformatics methods were used to identify the differently expressed proteins. 24 proteins had different expressions between the two groups. Among these 24 proteins, 8 proteins had increased expression in veterans' tears, while the remaining 16 proteins had decreased expression. Reactome pathways were used to look at proteins with various expressions, and 13 proteins were found to be engaged in the immune system, 9 of which were effective in the innate immune system, and 5 proteins were effective in the complement cascade. Ocular mustard gas exposure may cause a compromised immune system on the eye's surface, exposing the cornea to external and endogenous infections, and eventually causing corneal opacity and reduced vision.

Single-cell analysis of endometriosis reveals a coordinated transcriptional programme driving immunotolerance and angiogenesis across eutopic and ectopic tissues

Endometriosis is characterized by the growth of endometrial-like tissue outside the uterus. It affects many women during their reproductive age, causing years of pelvic pain and potential infertility. Its pathophysiology remains largely unknown, which limits early diagnosis and treatment. We characterized peritoneal and ovarian lesions at single-cell transcriptome resolution and compared them to matched eutopic endometrium, unaffected endometrium and organoids derived from these tissues, generating data on over 122,000 cells across 14 individuals. We spatially localized many of the cell types using imaging mass cytometry. We identify a perivascular mural cell specific to the peritoneal lesions, with dual roles in angiogenesis promotion and immune cell trafficking. We define an immunotolerant peritoneal niche, fundamental differences in eutopic endometrium and between lesion microenvironments and an unreported progenitor-like epithelial cell subpopulation. Altogether, this study provides a holistic view of the endometriosis microenvironment that represents a comprehensive cell atlas of the disease in individuals undergoing hormonal treatment, providing essential information for future therapeutics and diagnostics.

Pathological and therapeutic roles of bioactive peptide trefoil factor 3 in diverse diseases: recent progress and perspective

Trefoil factor 3 (TFF3) is the last small-molecule peptide found in the trefoil factor family, which is mainly secreted by intestinal goblet cells and exerts mucosal repair effect in the gastrointestinal tract. Emerging evidence indicated that the TFF3 expression profile and biological effects changed significantly in pathological states such as cancer, colitis, gastric ulcer, diabetes mellitus, non-alcoholic fatty liver disease, and nervous system disease. More importantly, mucosal protection would no longer be the only effect of TFF3, it gradually exhibits carcinogenic activity and potential regulatory effect of nervous and endocrine systems, but the inner mechanisms remain unclear. Understanding the molecular function of TFF3 in specific diseases might provide a new insight for the clinical development of novel therapeutic strategies. This review provides an up-to-date overview of the pathological effects of TFF3 in different disease and discusses the binding proteins, signaling pathways, and clinical application.

Gene Expression Analysis by Real-Time PCR in Nasal Brushings of Adult Patients with Allergic Rhinitis, Suspected Allergic Rhinitis, and Nonallergic Rhinitis

BACKGROUND

Epithelial gene expression in allergic rhinitis patients has been evaluated by microarray. However, gene expression in patients with nonallergic rhinitis and suspected allergic rhinitis who reported allergen-related nasal symptoms but presented a negative atopic test was unknown.

OBJECTIVES

The aim of this study was to observe and compare epithelial gene expression in patients with allergic rhinitis, suspected allergic rhinitis, and nonallergic rhinitis.

METHODS

Nasal brushings were collected from healthy controls and from patients with allergic rhinitis, suspected allergic rhinitis, and nonallergic rhinitis. The expressions of 20 genes selected from a previous microarray study were measured by real-time PCR. Associations of these genes with allergen type, disease duration and severity, the grade of nasal smear eosinophilia, and serum total IgE were analyzed.

RESULTS

Twelve genes were confirmed to be upregulated in current adult allergic rhinitis patients allergic to multiple allergens, and 10 of them were also increased in the suspected allergic rhinitis and nonallergic rhinitis groups. TFF3 and ITLN1 expressions were increased in allergic rhinitis and suspected allergic rhinitis, but not nonallergic rhinitis. Different expressions between the allergic rhinitis and nonallergic rhinitis groups were found for 3 genes: CST1, TFF3, and ITLN1. In the allergic rhinitis patients, all 12 genes were upregulated in the seasonal and perennial groups; 9 of these 12 genes were also upregulated in the mixed group. In suspected allergic rhinitis patients, all 12 genes were upregulated in the perennial group; 8 of these 12 genes were also upregulated in the seasonal group and only 5 in the mixed group. No gene expression was associated with disease duration and serum total IgE. GCNT3 was positively correlated with the grade of nasal smear eosinophilia in the suspected allergic rhinitis group. Different genes were found to be associated with disease severity in different rhinitis groups.

CONCLUSIONS

Patients with allergic rhinitis, suspected allergic rhinitis, and nonallergic rhinitis showed much similarity with regard to epithelial gene expression; most genes were related to Th2 inflammation. CST1, TFF3, and ITLN1 might have the ability to differentiate allergic rhinitis from nonallergic rhinitis. Understanding the mechanisms underlying different types of rhinitis may be helpful for rhinitis diagnosis and treatment.

Rotavirus infection induces glycan availability to promote ileum-specific changes in the microbiome aiding rotavirus virulence

Multiple studies have identified changes within the gut microbiome in response to diarrheal-inducing bacterial pathogens. However, examination of the microbiome in response to viral pathogens remains understudied. Compounding this, many studies use fecal samples to assess microbiome composition; which may not accurately mirror changes within the small intestine, the primary site for most enteric virus infections. As a result, the functional significance of small intestinal microbiome shifts during infection is not well defined. To address these gaps, rotavirus-infected neonatal mice were examined for changes in bacterial community dynamics, host gene expression, and tissue recovery during infection. Profiling bacterial communities using 16S rRNA sequencing suggested significant and distinct changes in ileal communities in response to rotavirus infection, with no significant changes for other gastrointestinal (GI) compartments. At 1-d post-infection, we observed a loss in Lactobacillus species from the ileum, but an increase in Bacteroides and Akkermansia, both of which exhibit mucin-digesting capabilities. Concomitant with the bacterial community shifts, we observed a loss of mucin-filled goblet cells in the small intestine at d 1, with recovery occurring by d 3. Rotavirus infection of mucin-producing cell lines and human intestinal enteroids (HIEs) stimulated release of stored mucin granules, similar to in vivo findings. In vitro, incubation of mucins with Bacteroides or Akkermansia members resulted in significant glycan degradation, which altered the binding capacity of rotavirus in silico and in vitro. Taken together, these data suggest that the response to and recovery from rotavirus-diarrhea is unique between sub-compartments of the GI tract and may be influenced by mucin-degrading microbes.

Structure, Function, and Therapeutic Potential of the Trefoil Factor Family in the Gastrointestinal Tract

Trefoil factor family peptides (TFF1, TFF2, and TFF3) are key players in protecting, maintaining, and repairing the gastrointestinal tract. Accordingly, they have the therapeutic potential to treat and prevent a variety of gastrointestinal disorders associated with mucosal damage. TFF peptides share a conserved motif, including three disulfide bonds that stabilize a well-defined three-loop-structure reminiscent of a trefoil. Although multiple functions have been described for TFF peptides, their mechanisms at the molecular level remain poorly understood. This review presents the status quo of TFF research relating to gastrointestinal disorders. Putative TFF receptors and protein partners are described and critically evaluated. The therapeutic potential of these peptides in gastrointestinal disorders where altered mucosal biology plays a crucial role in the underlying etiology is discussed. Finally, areas of investigation that require further research are addressed. Thus, this review provides a comprehensive update on TFF literature as well as guidance toward future research to better understand this peptide family and its therapeutic potential for the treatment of gastrointestinal disorders.

Odyssey of trefoil factors in cancer: Diagnostic and therapeutic implications

Trefoil factors 1, 2, and 3 (TFFs) are a family of small secretory molecules involved in the protection and repair of the gastrointestinal tract (GI). TFFs maintain and restore epithelial structural integrity via transducing key signaling pathways for epithelial cell migration, proliferation, and invasion. In recent years, TFFs have emerged as key players in the pathogenesis of multiple diseases, especially cancer. Initially recognized as tumor suppressors, emerging evidence demonstrates their key role in tumor progression and metastasis, extending their actions beyond protection. However, to date, a comprehensive understanding of TFFs' mechanism of action in tumor initiation, progression and metastasis remains obscure. The present review discusses the structural, functional and mechanistic implications of all three TFF family members in tumor progression and metastasis. Also, we have garnered information from studies on their structure and expression status in different organs, along with lessons from their specific knockout in mouse models. In addition, we highlight the emerging potential of using TFFs as a biomarker to stratify tumors for better therapeutic intervention.

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.

Trefoil Factor 3 (TFF3) Is Involved in Cell Migration for Skeletal Repair

The aim of the study was to explore the possible role of Trefoil Factor Family peptide 3 (TFF3) for skeletal repair. The expression of TFF3 was analyzed in human joint tissues as well as in a murine bone fracture model. Serum levels of TFF3 following a defined skeletal trauma in humans were determined by ELISA. The mRNA expression of TFF3 was analyzed under normoxia and hypoxia. Expression analysis after stimulation of human mesenchymal progenitor cells (MPCs) with TFF3 was performed by RT² Profiler PCR Array. The effect of recombinant human (rh)TFF3 on MPCs was analysed by different migration and chemotaxis assays. The effect on cell motility was also visualized by fluorescence staining of F-Actin. TFF3 was absent in human articular cartilage, but strongly expressed in the subchondral bone and periosteum of adult joints. Strong TFF3 immunoreactivity was also detected in murine fracture callus. Serum levels of TFF3 were significantly increased after skeletal trauma in humans. Expression analysis demonstrated that rhTFF3 significantly decreased mRNA of ROCK1. Wound healing assays showed increased cell migration of MPCs by rhTFF3. The F-Actin cytoskeleton was markedly influenced by rhTFF3. Cell proliferation was not increased by rhTFF3. The data demonstrate elevated expression of TFF3 after skeletal trauma. The stimulatory effects on cell motility and migration of MPCs suggest a role of TFF3 in skeletal repair.

Possible application of trefoil factor family peptides in gastroesophageal reflux and Barrett's esophagus

Gastroesophageal reflux disease (GERD) is a chronic disorder of the digestive tract characterised mainly by a heartburn. Being one of the most common gastrointestinal diseases, the prevalence of GERD reaches up to 25.9% in Europe. Barrett's esophagus (BE) is an acquired condition characterized by the replacement of the normal stratified squamous epithelium with metaplastic columnar epithelium. BE is believed to develop mainly from chronic GERD and is the most important risk factor of esophageal adenocarcinoma. Despite the availability of drugs such as proton pomp inhibitors and antacids, GERD is still a burden to local economy and impairs health-related quality of life in patients. Also, the endoscopic surveillance in patients with BE is burdensome and expensive what drives the need for biomarker of intestinal metaplasia and dysplasia. Trefoil factor family (TFF), consisting of TFF1, TFF2 and TFF3 peptides is gaining more and more attention due to its unique biochemical features and numerous functions. In this review the role of TFF1, TFF2 and TFF3 as potential treatment option and/or biomarker in the upper GI tract is discussed with particular focus on GERD and BE.

Plasma gelsolin promotes re-epithelialization

Woundhealing disorders characterized by impaired or delayed re-epithelialization are a serious medical problem that is painful and difficult to treat. Gelsolin (GSN), a known actin modulator, supports epithelial cell regeneration and apoptosis. The aim of this study was to estimate the potential of recombinant gelsolin (rhu-pGSN) for ocular surface regeneration to establish a novel therapy for delayed or complicated wound healing. We analyzed the influence of gelsolin on cell proliferation and wound healing in vitro, in vivo/ex vivo and by gene knockdown. Gelsolin is expressed in all tested tissues of the ocular system as shown by molecular analysis. The concentration of GSN is significantly increased in tear fluid samples of patients with dry eye disease. rhu-pGSN induces cell proliferation and faster wound healing in vitro as well as in vivo/ex vivo. TGF-β dependent transcription of SMA is significantly decreased after GSN gene knockdown. Gelsolin is an inherent protein of the ocular system and is secreted into the tear fluid. Our results show a positive effect on corneal cell proliferation and wound healing. Furthermore, GSN regulates the synthesis of SMA in myofibroblasts, which establishes GSN as a key protein of TGF-β dependent cell differentiation.

Trefoil factor 3 in perinatal pancreas is increased by gestational low protein diet and associated with accelerated β-cell maturation

The endocrine pancreas expands markedly in the first postnatal days and the insulin producing β-cells initiate a functional maturation preceded by a morphological change of the islets of Langerhans. Trefoil factor 3 (TFF3) is a secreted peptide expressed in intestinal epithelia, where it promotes migration, but its role in the pancreas is not characterized. The aim of this study was to examine the expression and function of TFF3 in perinatal rat pancreas, ex vivo cultured fetal rat pancreas and in the rat β-cell line INS-1E. Control or gestational low-protein diet perinatal rat pancreas was harvested at embryonic day 20 (E20), day of birth (P0) and postnatal day 2 (P2). TFF3 mRNA was upregulated 4.5-fold at P0 vs. E20 and downregulated again at P2. In protein-undernourished pups induction of TFF3 at P0 was further increased to 9.7-fold and was increased at P2. TFF3 caused tyrosine phosphorylation of EGFR in INS-1E β-cells, and purified recombinant TFF3 increased both attachment and spreading of INS-1E β-cells. In ex vivo cultures of collagenase digested fetal rat pancreas, a model of perinatal β-cell maturation, TFF3 increased cellular spreading as well as insulin mRNA levels. TFF3 also increased the expression of Pref1/Dlk1 that shares similarities in expression and regulation with TFF3. These results suggest that TFF3 may promote adhesion and spreading of cells to accelerate β-cell maturation. This study indicates a functional role for TFF3 in pancreatic β-cell maturation in the perinatal period, which is altered by low protein diet during gestation.

Epothilone B Speeds Corneal Nerve Regrowth and Functional Recovery through Microtubule Stabilization and Increased Nerve Beading

The successful restoration of corneal innervation and function after a corneal injury is a clinically challenging issue. Structural and functional recovery after a nerve injury involves a complex series of steps in which microtubules play a key role. The aim of the current study was to investigate the effects of epothilone B (EpoB), a microtubule-stabilizing agent, on corneal innervation and the functional recovery of the corneal nerve in mice after corneal epithelial abrasion. The pretreatment of mice with EpoB has a remarkable effect on the stabilization of beta-III tubulin, as demonstrated by substantial increases in the visualization of beta-III tubulin, nerve beading, corneal reinnervation, and reaction to stimuli. Furthermore, a pharmacokinetic analysis showed that EpoB remains at a high concentration in the cornea and the trigeminal ganglion for at least 6 days after administration. In addition, the administration of EpoB at 24 hours after corneal abrasion has a marked therapeutic effect on nerve regrowth and functional recovery. In conclusion, EpoB treatment may have therapeutic utility for improving corneal reinnervation and restoring sensitivity following corneal injury.

Obstructive sleep apnea and rhonchopathy are associated with downregulation of trefoil factor family peptide 3 (TFF3)-Implications of changes in oral mucus composition

Study objectives

Trefoil factor family (TFF) peptides belong to the family of mucin-associated peptides and are expressed in most mucosal surfaces. TFF peptides carry out functions such as proliferation and migration enhancement, anti-apoptosis, and wound healing. Moreover, TFFs are associated with mucins and interact with them as “linker peptides”, thereby influencing mucus viscosity.

To test the hypothesis that in rhonchopathy and obstructive sleep apnea (OSA) changes occur in the expression of TFF3 and -2 that could contribute to changes in mucus viscosity, leading to an increase in upper airway resistance during breathing.

Methods

RT-PCR, Western-blot, immunohistochemistry and ELISA were performed to detect and quantify TFF3 and -2 in uvula samples. In addition, 99 saliva samples from patients with mild, moderate or severe OSA, as well as samples from rhonchopathy patients and from healthy volunteers, were analyzed by ELISA.

Results

TFF3 was detected in all uvula samples. Immunohistochemistry revealed a subjectively decreasing antibody reactivity of the uvula epithelia with increasing disease severity. ELISA demonstrated significantly higher TFF3 saliva protein concentrations in the healthy control group compared to cases with rhonchopathy and OSA. Predisposing factors of OSA such as BMI or age showed no correlation with TFF3. No significant changes were observed with regard to TFF2.

Conclusions

The results suggest the involvement of TFF3 in the pathogenesis of rhonchopathy and OSA and lead to the hypothesis that reduction of TFF3 production by the epithelium and subepithelial mucous glands of the uvula contribute to an increase in breathing resistance due to a change in mucus organization.

Forced Trefoil Factor Family Peptide 3 (TFF3) Expression Reduces Growth, Viability, and Tumorigenicity of Human Retinoblastoma Cell Lines

Trefoil factor family (TFF) peptides have been shown to effect cell proliferation, apoptosis, migration and invasion of normal cells and various cancer cell lines. In the literature TFF peptides are controversially discussed as tumor suppressors and potential tumor progression factors. In the study presented, we investigated the effect of TFF3 overexpression on growth, viability, migration and tumorigenicity of the human retinoblastoma cell lines Y-79, WERI-Rb1, RBL-13 and RBL-15. As revealed by WST-1 and TUNEL assays as well as DAPI and BrdU cell counts, recombinant human TFF3 significantly lowers retinoblastoma cell viability and increases apoptosis levels. Transient TFF3 overexpression likewise significantly increases RB cell apoptosis. Stable, lentiviral TFF3 overexpression lowers retinoblastoma cell viability, proliferation and growth and significantly increases cell death in retinoblastoma cells. Blockage experiments using a broad-spectrum caspase inhibitor and capase-3 immunocytochemistry revealed the involvement of caspases in general and of caspase-3 in particular in TFF3 induced apoptosis in retinoblastoma cell lines. Soft agarose and in ovo chicken chorioallantoic membrane (CAM) assays revealed that TFF3 overexpression influences anchorage independent growth and significantly decreases the size of tumors forming from retinoblastoma cells. Our study demonstrates that forced TFF3 expression exerts a significant pro-apoptotic, anti-proliferative, and tumor suppressive effect in retinoblastoma cells, setting a starting point for new additive chemotherapeutic approaches in the treatment of retinoblastoma.

Goblet cells of the conjunctiva: A review of recent findings

Goblet cells within the conjunctival epithelium are specialized cells that secrete mucins onto the surface of the eye. Recent research has demonstrated new characteristics of the cells, including factors influencing their differentiation, their gene products and their functions at the ocular surface. The following review summarizes the newly discovered aspects of the role of Spdef, a member of the Ets transcription factor family in conjunctival goblet cell differentiation, the newly discovered goblet cell products including claudin2, the Wnt inhibitor Frzb, and the transmembrane mucin Muc16. The current concepts of conjunctival goblet cell function, including debris removal and immune surveillance are reviewed, as are changes in the goblet cell population in ocular surface diseases. Major remaining questions regarding conjunctival cell biology are discussed.

Trefoil factor 3 shows anti-inflammatory effects on activated microglia

Microglial cells are a major source of pro-inflammatory cytokines during central nervous system (CNS) inflammation. They can develop a pro-inflammatory M1 phenotype and an anti-inflammatory M2 phenotype. Shifting the phenotype from M1 to M2 might be an important mechanism to overcome CNS inflammation and to prevent or reduce neuronal damage. Here, we demonstrate that the anti-inflammatory protein trefoil factor 3 (TFF3) is secreted by astrocytes and that its transcription is significantly reduced after incubation with lipopolysaccharide (LPS). Moreover, we demonstrate that microglial cells cultured in the presence of TFF3 show reduced expression and secretion of pro-inflammatory cytokines after LPS stimulation.

Somatostatin supports corneal wound healing in vivo

PURPOSE

To evaluate the influence of somatostatin (SST) and its analog octreotid (Oct) on corneal wound healing processes.

METHODS

The wound healing rate in C57BL/6 mice eyes under SST and Oct treatment was analyzed using an alkali-induced corneal wounding model. Effects of SST and Oct on cell proliferation, migration and quantified protein expression of vascular endothelial growth factor (VEGF) on human corneal epithelial cells (HCE, cell line) were evaluated by means of electric cell-substrate impedance sensing, scratch migration assays and ELISA. ERK1/2 and p38 phosphorylation was investigated by semi-quantitative western blot analysis.

RESULTS

Ten nanograms per microliters of SST significantly accelerated the wound closure rate of corneal defects in vivo. SST and Oct had no influence on HCE cell proliferation and migration and did not activate ERK1/2 or p38 signaling in HCE cells. However, there was increased VEGF protein expression in cytosolic proteins and medium supernatants of HCE upon Oct stimulation for 24h. One and 10ng/ml Oct led to a 2.5-fold and 100ng/ml Oct to a 4-fold upregulation of VEGF protein expression.

CONCLUSION

The data implicate that SST promotes corneal wound healing in a mouse model. However, using a HCE cell line in vitro, the wound healing mechanism does not seem to be supported by proliferation and migration processes or by activation of ERK1/2 and p38 signaling pathways. Other possible mechanisms could be the activation of other pathways and the induction of growth factors such as VEGF that modulate the observed corneal wound healing process.

1,25-dihydroxyvitamin D3 inhibits corneal wound healing in an ex-vivo mouse model

PURPOSE

Impaired healing of corneal injuries can result in ulceration and complete loss of vision, especially in the elderly. Such patients frequently also exhibit vitamin D insufficiency. 1,25-dihydroxyvitamin D3 is the active vitamin D metabolite. As it affects cell proliferation and inflammation, we herein aimed at elucidating its influence on corneal wound healing after alkali burn by using in vitro and ex vivo techniques.

METHODS

mRNA abundance in human corneal epithelial cells in response to vitamin D3 was determined by RT-PCR. Corneal re-epithelialization after alkaline burn was analyzed using enucleated mouse eyes and fluorescein staining.

RESULTS

Human corneal epithelial cells (HCEC) expressed the vitamin D receptor (VDR) and retinoid x receptor (RXR) and were responsive to 1,25- dihydroxyvitamin D3, as shown by induction of the 1,25- dihydroxyvitamin D3 responsive gene cyp-24A1 and slightly reduced abundance of IL-6 mRNA. However, no effect on cell vitality and migration was observed. In contrast, re-epithelialization of mouse corneas ex vivo was dose dependently inhibited by 1,25- dihydroxyvitamin D3.

CONCLUSIONS

These data indicate that topically applied 1,25- dihydroxyvitamin D3 does not seem to be suitable for therapy of corneal lesions.

Serum Biomarkers of Allergic Contact Dermatitis: A Pilot Study

BACKGROUND

Allergic contact dermatitis (ACD) is an inflammatory skin disease caused by repeated skin exposure to contact allergens. The goal of this pilot study was to identify inflammatory proteins which can serve as biomarkers for ACD.

METHODS

We measured levels of 102 cytokines, chemokines, and growth factors in the sera of 16 ACD patients during acute and remission phases, and 16 healthy volunteers.

RESULTS

Serum levels of adiponectin, chemokine (C-C motif) ligand 5 (CCL5), C-reactive protein (CRP), chitinase 3-like 1 (CHI3L1), complement factor D (CFD), endoglin, lipocalin-2, osteopontin, retinol-binding protein 4 (RBP4), and platelet factor 4 (PF4) were significantly higher, whereas levels of trefoil factor 3 (TFF3) were significantly lower, in ACD patients than in healthy controls. In ACD patients, serum levels of CCL5 were elevated, whereas levels of TFF3, soluble intercellular adhesion molecule-1 (sICAM-1), and platelet-derived growth factor (PDGF)-AB/BB were found to be lower during the remission phase of the disease.

CONCLUSIONS

Serum levels of adiponectin, CCL5, CRP, CHI3L1, CFD, endoglin, lipocalin-2, osteopontin, RBP4, PF4, and TFF3 might be exploited as biomarkers for ACD, whereas levels of CCL5, TFF3, sICAM-1, and PDGF-AB/BB might be exploited for evaluation of disease progression and efficacy of ACD treatment.

Limited evidence of chondrocyte outgrowth from adult human articular cartilage

OBJECTIVE

Cellular outgrowth from articular cartilage tissue has been described in a number of recent experimental studies. The aim of this study was to investigate the occurrence of cellular outgrowth from articular cartilage explants isolated from adult human donors.

METHOD

Macroscopically intact articular cartilage specimens were isolated from adult human donors and cultured either in their native status, or in a cleansed status achieved by forced washing to minimize attaching cells. Additionally, the effect of chemotactic stimuli including cell lysate, High-Mobility-Group-Protein B1 (HMGB-1), Trefoil-factor 3 (TFF3), bone morphogenetic protein-2 (BMP-2), transforming growth factor-ß1 (TGF-ß1), or three-dimensional fibrin or collagen matrices were investigated. Co-cultures with synovial membrane served as a positive control for a source of migratory cells. The occurrence of cellular outgrowth was analyzed by histological examination after a culture period of 4 weeks.

RESULTS

Spontaneous cellular outgrowth from cleansed cartilage specimens was not observed at a relevant level and could not significantly be induced by chemotactic stimuli or three-dimensional matrices either. A forming cartilage-adjoining cell layer was only apparent in the case of native cartilage explants with cellular remnants from surgical isolation or in co-culture experiments with synovial membrane.

CONCLUSION

The relevance of cellular outgrowth from cartilage tissue is largely absent in the case of adult human articular cartilage samples. A cartilage-adjoining cell layer forming around the explants may instead originate from still attaching cells that remained from surgical isolation.

Trefoil factor family peptides – friends or foes?

Trefoil factor family (TFF) peptides are a group of molecules bearing a characteristic three-loop trefoil domain. They are mainly secreted in mucous epithelia together with mucins but are also synthesized in the nervous system. For many years, TFF peptides were only known for their wound healing and protective function, e.g. in epithelial protection and restitution. However, experimental evidence has emerged supporting a pivotal role of TFF peptides in oncogenic transformation, tumorigenesis and metastasis. Deregulated expression of TFF peptides at the gene and protein level is obviously implicated in numerous cancers, and opposing functions as oncogenes and tumor suppressors have been described. With regard to the regulation of TFF expression, epigenetic mechanisms as well as the involvement of various miRNAs are new, promising aspects in the field of cancer research. This review will summarize current knowledge about the expression and regulation of TFF peptides and the involvement of TFF peptides in tumor biology and cancerogenesis.

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.

Epidermal growth factor containing culture supernatant enhances intestine development of early-weaned pigs in vivo: potential mechanisms involved

We have previously generated epidermal factor expressing Lactococcus lactis (EGF-LL) using a bioengineering approach, and shown that EGF-LL fermentation supernatant enhanced newly weaned pigs growth. The objective of the current study was to further understand the mechanisms behind this improved performance. Sixty-four piglets were weaned at 3 weeks of age and then fed ad libitum according to a 2-phase feeding program. Four pens with 8 pigs per pen were assigned to each of two treatments for 3 weeks: (1) EGF containing supernatant from EGF-LL culture (SuperEGF) or (2) blank M17GE media (Control). Consistent with previous findings, SuperEGF pigs had an increased average daily gain during week 3 post-weaning (433.4 ± 10.86 vs 388.7 ± 7.76 g; P<0.05) and overall gain:feed ratio (0.757 ± 0.03 vs 0.677 ± 0.01 kg/kg, P < 0.05). Moreover, jejunal structure development was enhanced, and inflammation index was minimized in SuperEGF pigs as indicated by increased villi height (P<0.05), decreased lamina propria width (P<0.05), and higher expression of anti-inflammatory cytokine, IL-13 (P<0.05). Further, goblet cell numbers and Muc2 levels were increased in SuperEGF pigs. Interestingly, the weaning-induced decrease of glucose cotransporter sodium-glucose linked transporter 1 (SGLT1) and glucagon-like peptide-2 (GLP2) levels was reversed by SuperEGF supplementation. Our findings add to our understanding of the mechanisms behind enhancing piglet performance by EGF containing fermentation product.

Genomic instability in liver cells caused by an LPS-induced bystander-like effect

Bacterial infection has been linked to carcinogenesis, however, there is lack of knowledge of molecular mechanisms that associate infection with the development of cancer. We analyzed possible effects of the consumption of heat-killed E. coli O157:H7 cells or its cellular components, DNA, RNA, protein or lipopolysaccharides (LPS) on gene expression in naïve liver cells. Four week old mice were provided water supplemented with whole heat-killed bacteria or bacterial components for a two week period. One group of animals was sacrificed immediately, whereas another group was allowed to consume uncontaminated tap water for an additional two weeks, and liver samples were collected, post mortem. Liver cells responded to exposure of whole heat-killed bacteria and LPS with alteration in γH2AX levels and levels of proteins involved in proliferation, DNA methylation (MeCP2, DNMT1, DNMT3A and 3B) or DNA repair (APE1 and KU70) as well as with changes in the expression of genes involved in stress response, cell cycle control and bile acid biosynthesis. Other bacterial components analysed in this study did not lead to any significant changes in the tested molecular parameters. This study suggests that lipopolysaccharides are a major component of Gram-negative bacteria that induce molecular changes within naïve cells of the host.

Lacritin and the tear proteome as natural replacement therapy for dry eye

Tear proteins are potential biomarkers, drug targets, and even biotherapeutics. As a biotherapeutic, a recombinant tear protein might physiologically rescue the ocular surface when a deficiency is detected. Such a strategy pays more attention to the natural prosecretory and protective properties of the tear film and seeks to alleviate symptoms by addressing cause, rather than the current palliative, non-specific and temporary approaches. Only a handful of tear proteins appear to be selectively downregulated in dry eye, the most common eye disease. Lacritin and lipocalin-1 are two tear proteins selectively deficient in dry eye. Both proteins influence ocular surface health. Lacritin is a prosecretory mitogen that promotes basal tearing when applied topically. Levels of active monomeric lacritin are negatively regulated by tear tissue transglutaminase, whose expression is elevated in dry eye with ocular surface inflammation. Lipocalin-1 is the master lipid sponge of the ocular surface, without which residual lipids could interfere with epithelial wetting. It also is a carrier for vitamins and steroid hormones, and is a key endonuclease. Accumulation of DNA in tears is thought to be proinflammatory. Functions of these and other tear proteins may be influenced by protein-protein interactions. Here we discuss new advances in lacritin biology and provide an overview on lipocalin-1, and newly identified members of the tear proteome.

Insulin-like factor 3 promotes wound healing at the ocular surface

Tear fluid is known to contain many different hormones with relevance for ocular surface homeostasis. We studied the presence and functional role of insulin-like factor 3 (INSL3) and its cognate receptor RXFP2 (relaxin/insulin-like family peptide receptor 2) at the ocular surface and in tears. Expression of human INSL3 and RXFP2 was determined in tissues of the ocular surface and lacrimal apparatus; in human corneal (HCE), conjunctival (HCjE), and sebaceous (SC) epithelial cell lines; and in human tears by RT-PCR and ELISA. We investigated effects of human recombinant INSL3 (hrINSL3) on cell proliferation and cell migration and the influence of hrINSL3 on the expression of MMP2, -9, and -13 and TIMP1 and -2 was quantified by real-time PCR and ELISA in HCE, HCjE, and SC cells. We used a C57BL/6 mouse corneal defect model to elucidate the effect of topical application of hrINSL3 on corneal wound healing. INSL3 and RXFP2 transcripts and INSL3 protein were detected in all tissues and cell lines investigated. Significantly higher concentrations of INSL3 were detected in tears from male vs. female volunteers. Stimulation of HCE, HCjE, and SC with hrINSL3 significantly increased cell proliferation in HCjE and SC and migration of HCjE. Treatment with hrINSL3 for 24 hours regulated MMP2, TIMP1, and TIMP2 expression. The local application of hrINSL3 onto denuded corneal surface resulted in significantly accelerated corneal wound healing in mice. These findings suggest a novel and gender-specific role for INSL3 and cognate receptor RXFP2 signaling in ocular surface homeostasis and determined a novel role for hrINSL3 in corneal wound healing.

Trefoil factor family protein 3 (TFF3) is present in cartilage during endochondral ossification in the developing mouse fetus

Trefoil factor family protein 3 (TFF3) is found in cartilage affected by osteoarthritis and septic arthritis, whereas no TFF3 presence is observed in healthy cartilage. During endochondral ossification, bone tissue replaces degenerating cartilage. There is no data about the role of TFF3 in this process. Our aim was to study the localization of TFF3 in cartilage during endochondral ossification in the mouse fetus. CD1 mouse fetuses, days 14-17, were isolated, fixed, and paraffin embedded. Fetuses were cut into 6μm sections, and processed for immunohistochemical staining with affinity purified polyclonal rabbit anti-TFF3 antibody. TFF3 was present in cartilage chondrocytes undergoing endochondral ossification, particularly in zone of proliferation, hypertrophy and calcification as well as in zone of cartilage degeneration during the monitored fetal period. Resting cartilage showed no presence of TFF3, while during endochondral ossification TFF3 localization showed an analogous pattern to that reported in cartilage affected by osteoarthritis and septic arthritis. Our data indicate that the role of TFF3 in these pathological conditions is similar to its role in the physiological process of endochondral ossification.

Cardioprotective proteins upregulated in the liver in response to experimental myocardial ischemia

Myocardial ischemia (MI) activates innate cardioprotective mechanisms, enhancing cardiomyocyte tolerance to ischemia. Here, we report a MI-activated liver-dependent mechanism for myocardial protection. In response to MI in the mouse, hepatocytes exhibited 6- to 19-fold upregulation of genes encoding secretory proteins, including α-1-acid glycoprotein (AGP)2, bone morphogenetic protein-binding endothelial regulator (BMPER), chemokine (C-X-C motif) ligand 13, fibroblast growth factor (FGF)21, neuregulin (NRG)4, proteoglycan 4, and trefoil factor (TFF)3. Five of these proteins, including AGP2, BMPER, FGF21, NRG4, and TFF3, were identified as cardioprotective proteins since administration of each protein significantly reduced the fraction of myocardial infarcts (37 ± 9%, 34 ± 7%, 32 ± 8%, 39 ± 6%, and 31 ± 7%, respectively, vs. 48 ± 7% for PBS at 24 h post-MI). The serum level of the five proteins elevated significantly in association with protein upregulation in hepatocytes post-MI. Suppression of a cardioprotective protein by small interfering (si)RNA-mediated gene silencing resulted in a significant increase in the fraction of myocardial infarcts, and suppression of all five cardioprotective proteins with siRNAs further intensified myocardial infarction. While administration of a single cardioprotective protein mitigated myocardial infarction, administration of all five proteins furthered the beneficial effect, reducing myocardial infarct fractions from PBS control values from 46 ± 6% (5 days), 41 ± 5% (10 days), and 34 ± 4% (30 days) to 35 ± 5%, 28 ± 5%, and 24 ± 4%, respectively. These observations suggest that the liver contributes to cardioprotection in MI by upregulating and releasing protective secretory proteins. These proteins may be used for the development of cardioprotective agents.

High trefoil factor 1 (TFF1) expression in human retinoblastoma cells correlates with low growth kinetics, increased cyclin-dependent kinase (CDK) inhibitor levels and a selective down-regulation of CDK6

Trefoil factor family (TFFs) peptides facilitate epithelial restitution, but also effect cell proliferation and apoptosis of normal and various cancer cell lines. In a recent study by our group, TFF2 expression was demonstrated in the murine retina, where it exhibits pro-proliferative and pro-apoptotic effects. In the present study, we investigated the expression and function of TFF peptides in eight human retinoblastoma cell lines. TFF1 was the only TFF peptide expressed at detectable levels in immunoblots of retinoblastoma cells. TFF1 expression levels were highly variable in different retinoblastoma cell lines and negatively correlated with cell growth curves. Recombinant human TFF1 had a negative effect on cell viability and caused a reduction in cell proliferation. Retinoblastoma cell lines with high TFF1 expression levels exhibited a selective down-regulation of cyclin-dependent kinase (CDK) 6, whereas CDK4 and CDK2 seem to be unaffected by TFF1 expression. In immunocytochemical studies, we observed a nuclear co-localization of TFF1 and CDK2 in Cajal bodies (CBs). In high TFF1 expressing human retinoblastoma cell lines CBs were smaller and higher in number compared to retinoblastoma lines with low TFF1 expression, indicating differences in cell cycle status between the different retinoblastoma cell lines. Our data further support the notion for a potential tumor suppressor function of TFF1. The nuclear localization of TFF1 in CBs--considered to play a role in cell cycle progression, potentially acting as a platform for CDK-cyclin function-offers a new impetus in the ongoing search for potential TFF1 interacting proteins.

Bone marrow cells and CD117-positive haematopoietic stem cells promote corneal wound healing

PURPOSE

The present study was conducted to evaluate the therapeutic effects of topically applied bone marrow (BM) cells and CD117-positive haematopoietic stem (CD117(+)) cells on alkali-induced corneal ulcers.

METHODS

Bone marrow cells and CD117(+) cells were isolated from syngenic mice and labelled with an intracellular cell tracer. Defined corneal wounds were produced in 89 eyes of syngenic mice and allowed to partially heal in vivo for 6 hr. The alkali-burned eyes were enucleated 6 hr postinjury and randomly divided into three groups. Control group (33 eyes) was incubated with medium only. The treatment groups received either BM cells (30 eyes) or CD117(+) cells (26 eyes) suspended in medium. Re-epithelialization process of corneal defects was qualitatively and quantitatively assessed and statistically analysed. The corneas were examined by histological and immunohistochemical methods.

RESULTS

We found that the re-epithelialization of corneal wounds in both treatment groups was significantly accelerated as compared to the control group. During the follow-up period (85 hr), the corneal transparency was comparable in all groups. Morphological investigations of corneas from control and treatment group showed no evident differences in the phenotype of the regenerated epithelium. Additionally, corneas in the treatment groups were devoid of donor-derived BM cells and CD117(+) cells, respectively.

CONCLUSIONS

This study provides evidence that topical application of BM cells or CD117(+) cells can be used to reconstruct corneal surfaces. Because neither BM cells nor CD117(+) cells were integrated into the corneal epithelium, we suggest that soluble factors could be responsible for the positive effect of BM cells and CD117(+) cells on corneal wound healing.

Two-photon fluorescence lifetime imaging monitors metabolic changes during wound healing of corneal epithelial cells in vitro

BACKGROUND

Early and correct diagnosis of delayed or absent corneal epithelial wound healing is a key factor in the prevention of infection and consecutive destruction of the corneal stroma with impending irreversible visual loss. Two-photon microscopy (TPM) is a novel technology that has potential to depict epithelial cells and to evaluate cellular function by measuring autofluorescence properties such as fluorescence intensity and fluorescence lifetimes of metabolic co-factors such as NAD(P)H.

METHODS

Using non-invasive TPM in a tissue-culture scratch model and an organ-culture erosion model, fluorescence intensity and fluorescence lifetimes of NAD(P)H were measured before and during closure of the epithelial wounds. Influence of temperature and selective inhibition of metabolism on intensity and lifetimes were tested additionally.

RESULTS

Decrease of temperature resulted in significant increase of fluorescence lifetimes and decrease of the relative amount of free NAD(P)H due to decreased global metabolism. Increase in temperature and upregulation of glycolysis through blocking the mitochondrial electron transport chain by rotenone resulted in increased intensity, decreased lifetimes and increase in the relative amount of free NAD(P)H. Changes of lifetimes and free:protein-bound NAD(P)H ratios were similar to changes measured during wound healing in both scratch and erosion models.

CONCLUSIONS

Fluorescence lifetime measurements (FLIM) detected enhancement of cellular metabolism following epithelial damage in both models. The prospective detection of cellular autofluorescence in vivo, in particular FLIM of metabolic cofactor NAD(P)H, has the potential to become an indispensible tool in clinical use to differentiate healing from non-healing epithelial cells and to evaluate effects of newly developed substances on cellular metabolism in preclinical and clinical trials.

Trefoil factor 2 rapidly induces interleukin 33 to promote type 2 immunity during allergic asthma and hookworm infection

The repair protein trefoil factor 2 promotes Th2 responses to helminth infection and allergens in part by inducing IL-33.

The molecular mechanisms that drive mucosal T helper type 2 (T_H2) responses against parasitic helminths and allergens remain unclear. In this study, we demonstrate in mice that TFF2 (trefoil factor 2), an epithelial cell–derived repair molecule, is needed for the control of lung injury caused by the hookworm parasite Nippostrongylus brasiliensis and for type 2 immunity after infection. TFF2 is also necessary for the rapid production of IL-33, a T_H2-promoting cytokine, by lung epithelia, alveolar macrophages, and inflammatory dendritic cells in infected mice. TFF2 also increases the severity of allergic lung disease caused by house dust mite antigens or IL-13. Moreover, TFF2 messenger RNA expression is significantly increased in nasal mucosal brushings during asthma exacerbations in children. These experiments extend the biological functions of TFF2 from tissue repair to the initiation and maintenance of mucosal T_H2 responses.

Trefoil factor family peptide 2 acts pro-proliferative and pro-apoptotic in the murine retina

Although expression of trefoil factor family (TFF) peptides has been reported in the brain, nothing is known about TFF expression in the retina. The aim of this study was to test whether TFF peptides are expressed in the murine retina and have any function here. In contrast to most tissues studied, where TFF1 and TFF3 are the predominant peptides, TFF2 is the only peptide expressed in the murine retina. Immunohistochemical studies on murine retinal sections indicate that cells of the ganglion cell layer are the retinal source for murine TFF2 (Tff2). In organotypic murine retina cell cultures recombinant TFF2 exerted a strong pro-apoptotic and pro-proliferative rather than an anti-apoptotic and anti-proliferating effect described in most human cancer cell lines investigated so far. In blockage experiments we were able to demonstrate that the pro-apoptotic effect of TFF2 is caspase-dependent. Western blot analysis of TFF2 treated retinal wholemount homogenates revealed significant reductions in the phosphorylation level of ERK and STAT3 proteins compared to basal conditions, suggesting that in the developing murine retina survival mechanism are down-regulated upon TFF2 administration. Our results suggest that during retinal cell death periods, requiring a tightly regulated balance between cell survival and cell death, TFF2 acts pro-proliferative and pro-apoptotic at least in developing mouse retinae cultured in vivo.

Upregulated expression of hITF in Crohn's disease and screening of hITF Interactant by a yeast two-hybrid system

AIMS

To study the expression of human intestinal trefoil factor (hITF) mRNA in Crohn's disease and to screen the cellular proteins that can interact with the hITF protein by a yeast two-hybrid system in order to explore the mechanism of hITF in protecting intestinal mucosa from injury.

METHODS

Seventy-eight patients underwent double-balloon enteroscopy (DBE). Expression of hITF mRNA was detected by quantitative real-time polymerase chain reaction analysis (qRT-PCR). The hITF gene was amplified by PCR and cloned into vector pDEST32. The yeast cells cotransformed with pDEST32-hITF and the human jejunal cDNA library were plated in a selective SC-Leu-Trp-His-Ura medium. The subsequent screen was performed with χ-gal detection, and true-positive clones were sequenced and analyzed with bioinformatics. Co-immunoprecipitation (Co-IP) was performed to confirm the binding of putative proteins to the hITF protein.

RESULTS

Thirty-nine patients were diagnosed with Crohn's disease. We found that the expression of hITF mRNA is significantly increased in Crohn's disease compared to normal controls. A total of ten colonies were selected and sequenced. Among these, six colonies were Homo sapiens zinc finger protein 193 (ZNF193), three colonies were Homo sapiens Aldo-keto reductase family 1C 1 (AKR1C1), and one colony was of an unknown gene. A reverse two-hybrid experiment and Co-IP indicated that ZNF193 and AKR1C1 might interact with hITF.

CONCLUSIONS

The expression of hITF mRNA is increased in Crohn's disease. ZNF193 and AKR1C1 are proteins that can interact with the hITF protein by a yeast two-hybrid system and Co-IP, hITF may contribute to the mucosal repair through this interaction.

In vivo action of trefoil factor 2 (TFF2) to speed gastric repair is independent of cyclooxygenase

OBJECTIVE

Trefoil factor (TFF) peptides are expressed in gastric tissues, where they are part of the epithelial defences. To complement previous in vitro work, the goal of the present study was to examine directly if TFF2 was essential for gastric restitution in vivo during the recovery from microscopic damage.

DESIGN

TFF2 mutant (KO) mice were examined to study the epithelial repair process in vivo after laser-induced photodamage (LPD). Using two-photon laser energy absorption (710 nm), LPD was imposed on an approximately 3-5 cell region of surface epithelium in anaesthetised mouse stomach. Responses to damage were evaluated during confocal time-lapse microscopy; including area of damage and the extracellular pH adjacent to the damaged surface (Cl-NERF pH sensor).

RESULTS

In control (TFF2+/+ and TFF2+/-) mice, damaged cells were exfoliated and the damaged epithelium was repaired by indomethacin. The resting surface pH was similar between control and TFF2-KO animals, but the post-LPD alkalisation of surface pH observed in control mice (pH 0.3 + or - 0.05, n=21) was attenuated in the TFF2-KO stomach (pH -0.08 + or - 0.09, n=18). Recobinant rat TFF3 partially rescued the attenuated surface pH change in TFF2-KO stomach, in the presence or absence of indomethacin.

CONCLUSIONS

In the gastric epithelium in vivo, TFFs promote epithelial restitution via a mechanism that does not require cyclooxygenase activation. A novel role for TFFs to affect gastric surface pH is observed.

Synthesis and localization of trefoil factor family (TFF) peptides in the human urinary tract and TFF2 excretion into the urine

Trefoil factor family (TFF) peptides promote regeneration and repair processes of mucous epithelia. They also probably play a key role in the remarkable regenerative capacity of the urinary tract epithelia. We have localized TFF1, TFF2, and TFF3 expression systematically in surgical specimens from the urinary tract by reverse transcription with the polymerase chain reaction, Western blot analysis, and immunohistochemistry. Urine samples from patients suffering from nephrolithiasis have been investigated and compared with those of healthy controls. TFF synthesis is detectable along the entire urinary tract epithelia. TFF3 synthesis is the most pronounced followed by TFF1, whereas TFF2 synthesis is occasionally detectable but only in trace amounts. In contrast, TFF2 is the predominant TFF peptide excreted into the urine, and significantly increased urinary TFF2 levels (together with occasionally raised TFF3 levels) have been observed in patients suffering from nephrolithiasis. Thus, we consider that TFF3 plays a major part in regeneration and restitution processes in urinary tract epithelia. TFF2 and probably also TFF3 are candidate biomarkers for nephrolithiasis and possibly other inflammatory conditions of the urinary tract.

Trefoil factor 3 is induced during degenerative and inflammatory joint disease, activates matrix metalloproteinases, and enhances apoptosis of articular cartilage chondrocytes

OBJECTIVE

Trefoil factor 3 (TFF3, also known as intestinal trefoil factor) is a member of a family of protease-resistant peptides containing a highly conserved motif with 6 cysteine residues. Recent studies have shown that TFF3 is expressed in injured cornea, where it plays a role in corneal wound healing, but not in healthy cornea. Since cartilage and cornea have similar matrix properties, we undertook the present study to investigate whether TFF3 could induce anabolic functions in diseased articular cartilage.

METHODS

We used reverse transcriptase-polymerase chain reaction, Western blot analysis, and immunohistochemistry to measure the expression of TFF3 in healthy articular cartilage, osteoarthritis (OA)-affected articular cartilage, and septic arthritis-affected articular cartilage and to assess the effects of cytokines, bacterial products, and bacterial supernatants on TFF3 production. The effects of TFF3 on matrix metalloproteinase (MMP) production were measured by enzyme-linked immunosorbent assay, and effects on chondrocyte apoptosis were studied by caspase assay and annexin V assay.

RESULTS

Trefoil factors were not expressed in healthy human articular cartilage, but expression of TFF3 was highly up-regulated in the cartilage of patients with OA. These findings were confirmed in animal models of OA and septic arthritis, as well as in tumor necrosis factor alpha- and interleukin-1beta-treated primary human articular chondrocytes, revealing induction of Tff3/TFF3 under inflammatory conditions. Application of the recombinant TFF3 protein to cultured chondrocytes resulted in increased production of cartilage-degrading MMPs and increased chondrocyte apoptosis.

CONCLUSION

In this study using articular cartilage as a model, we demonstrated that TFF3 supports catabolic functions in diseased articular cartilage. These findings widen our knowledge of the functional spectrum of TFF peptides and demonstrate that TFF3 is a multifunctional trefoil factor with the ability to link inflammation with tissue remodeling processes in articular cartilage. Moreover, our data suggest that TFF3 is a factor in the pathogenesis of OA and septic arthritis.

Relationship between TFF3 expression and gastric cardiac carcinogenesis

AIM: To explore the relationship between the expression of trefoil factor 3 (TFF3) protein and the evolution of gastric cardiac adenocarcinoma.

METHODS: The streptavidin-peroxidase immunohistochemistry method was used to detect TFF3 protein expression in 24 cardiac gastritis specimens, 52 intestinal metaplasia specimens, 65 specimens of intestinal metaplasia with dysplasia and 35 gastric cardiac adenocarcinoma specimens from a high incidence area of gastric cardiac adenocarcinoma in Henan.

RESULTS: TFF3 protein is predominantly expressed in the striated border of the columnar cells in cardiac gastritis and intestinal metaplasia tissues, and in the cytoplasm in dysplasia and carcinoma tissues. The positive rates of TFF3 protein in cardiac gastritis, intestinal metaplasia, dysplasia, and carcinoma tissues were 20.8%, 44.2%, 46.2% and 54.3%, respectively. The expression of TFF3 was correlated well with the pathological grade of the lesions (r = 0.232, P < 0.05). The location of TFF3 expression was correlated with the pathological types of the lesions (Kappa = 0.490).

CONCLUSION: Overexpression of TFF3 protein in the cytoplasm is involved in gastric cardiac carcinogenesis and might be one of important risk factors for gastric cardiac adenocarcinoma.

Colitis-associated variant of TLR2 causes impaired mucosal repair because of TFF3 deficiency

BACKGROUND & AIMS

Goblet cells (GC) facilitate mucosal protection and epithelial barrier repair, yet the innate immune mechanisms that selectively drive GC functions have not been defined. The aim of this study was to determine whether Toll-like receptor (TLR) 2 and modulation of GC-derived trefoil factor (TFF) 3 are functionally linked in the intestine.

METHODS

GC modulation was assessed using quantitative real-time polymerase chain reaction analysis (qRT-PCR), Western blotting, and confocal microscopy. Dextran sulfate sodium (DSS) colitis was induced in wild-type, TFF3(-/-), and TLR2(-/-) mice. Recombinant TLR2 ligand or TFF3 peptide were orally administered after DSS termination. Caco-2 cells overexpressing full-length TLR2 or mutant TLR2-R753Q were tested for TFF3 synthesis and functional-related effects in a wounding assay.

RESULTS

Data from in vitro (Ls174T) and ex vivo models of murine and human GC reveal that TLR2 activation selectively induces synthesis of TFF3. In vivo studies using TFF3(-/-) or TLR2(-/-) mice demonstrate the ability for oral treatment with a TLR2 agonist to confer antiapoptotic protection of the intestinal mucosa against inflammatory stress-induced damage through TFF3. Recombinant TFF3 rescues TLR2-deficient mice from increased morbidity and mortality during acute colonic injury. Severe ulcerative colitis (UC) has recently been found to be associated with the R753Q polymorphism of the TLR2 gene. The relevance of the observed functional effect of TLR2 in regulating GC is confirmed by the finding that the UC-associated TLR2-R753Q variant is functionally deficient in the ability to induce TFF3 synthesis, thus leading to impaired wound healing.

CONCLUSIONS

These data demonstrate a novel function of TLR2 in intestinal GC that links products of commensal bacteria to innate immune protection of the host via TFF3.