IgG Fc-binding protein positively regulates the assembly of pore-forming protein complex βγ-CAT evolved to drive cell vesicular delivery and transport

Cell membranes form barriers for molecule exchange between the cytosol and the extracellular environments. βγ-CAT, a complex of pore-forming protein (PFP) BmALP1 (two βγ-crystallin domains with an aerolysin pore-forming domain) and the trefoil factor BmTFF3, has been identified in toad Bombina maxima. It plays pivotal roles, via inducing channel formation in various intra- or extra- cellular vesicles, as well as in nutrient acquisition, maintaining water balance, and antigen presentation. Thus, such a protein machine should be tightly regulated. Indeed, BmALP3 (a paralog of BmALP1) oxidizes BmALP1 to form a water-soluble polymer, leading to dissociation of the βγ-CAT complex and loss of biological activity. Here, we found that the B. maxima IgG Fc-binding protein (FCGBP), a well-conserved vertebrate mucin-like protein with unknown functions, acted as a positive regulator for βγ-CAT complex assembly. The interactions among FCGBP, BmALP1, and BmTFF3 were revealed by co-immunoprecipitation assays. Interestingly, FCGBP reversed the inhibitory effect of BmALP3 on the βγ-CAT complex. Furthermore, FCGBP reduced BmALP1 polymers and facilitated the assembly of βγ-CAT with the biological pore-forming activity in the presence of BmTFF3. Our findings define the role of FCGBP in mediating the assembly of a PFP machine evolved to drive cell vesicular delivery and transport.

Investigation of the Relationship Between Trefoil Factor Family Peptides and Sinonasal Inflammation

The trefoil factor family (TFF) is a relatively new family of peptides. In some studies, an association between trefoil factors and inflammatory diseases of the nasal and paranasal sinuses has been suggested. However, it is still not clear whether there is a relationship between trefoil peptides and inflammation of the respiratory tract. The aims of this study are to determine the presence of TFF1, TFF2, and TFF3 in the nasal mucosa and investigate their relationships with inflammation by using rat models of various sinonasal inflammations. Nasal tampon, lipopolysaccharide, and ovalbumin were used to generate rat models of sinonasal inflammation, i.e., rhinosinusitis and allergic rhinitis. The study was conducted on seventy rats in seven groups, each with ten rats: four groups with rhinosinusitis, two groups with allergic rhinitis, and a control group. Histological evaluation of sinonasal mucosa from all rats was performed, and Trefoil factors were investigated using immunohistochemical methods. All three TFF peptides were detected in rat nasal mucosa by histological evaluation. No significant differences in the trefoil factor scores were observed among the study groups. A significant correlation between the TFF1 and TFF3 scores and loss of cilia was identified (p < 0.05). In conclusion, no direct relationship between sinonasal inflammation and TFF scores was observed. However, a possible association between the TFF and epithelial damage or regeneration in sinonasal inflammation can be suggested based on the correlation observed between the TFF1 and TFF3 scores and scores of cilia loss.

Mechanistic study of PDIA1-catalyzed TFF3 dimerization during sepsis

AIMS

Trefoil factor 3 (TFF3) is a gut mucosal protective molecule that is secreted by intestinal goblet cells. The dimeric structure of TFF3 enables it to function in intestinal mucosal repair and to maintain its own stability. Protein disulfide isomerase a1 (PDIA1) can directly catalyze the formation, isomerization and reduction of disulfide bonds in proteins and may play an important role in the formation of TFF3 dimer. In this study, we focused on the specific molecular mechanism of TFF3 dimerization by PDIA1 and the changes during sepsis.

METHODS

We examined the changes of PDIA1 and TFF3 in sepsis rats and cell models and used a variety of experimental techniques to investigate the specific molecular mechanism of PDIA1-catalyzed TFF3 dimerization.

KEY FINDINGS

We found that PDIA1 can directly catalyze the dimerization of TFF3. Our MD model proposed that two TFF3 monomers form hydrogen bonds with the region b' of PDIA1 through two stepwise reactions. Furthermore, we propose that the Cys24-Cys27 active site at the region a' of PDIA1 mediates disulfide bond formation between the Cys79 residues of each of the two TFF3 monomers via deprotonation and nucleophilic attack. During sepsis, PDIA1 is downregulated and the excessive release of nitric oxide (NO) promoted PDIA1 nitrosylation. This modification reduced PDIA1 activity, which resulted in the corresponding decrease of TFF3 dimerization and compromised TFF3 dimer function.

SIGNIFICANCE

Our study revealed a novel mechanism for the inhibition of intestinal mucosal repair during sepsis and revealed novel targets for the prevention and treatment of sepsis.

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.

Trefoil factor(s) and CA19.9: A promising panel for early detection of pancreatic cancer

Background

Trefoil factors (TFF1, TFF2, and TFF3) are small secretory molecules that recently have gained significant attention in multiple studies as an integral component of pancreatic cancer (PC) subtype-specific gene signature. Here, we comprehensively investigated the diagnostic potential of all the member of trefoil family, i.e., TFF1, TFF2, and TFF3 in combination with CA19.9 for detection of PC.

Methods

Trefoil factors (TFFs) gene expression was analyzed in publicly available cancer genome datasets, followed by assessment of their expression in genetically engineered spontaneous mouse model (GEM) of PC (KrasG12D; Pdx1-Cre (KC)) and in human tissue microarray consisting of normal pancreas adjacent to tumor (NAT), precursor lesions (PanIN), and various pathological grades of PC by immunohistochemistry (IHC). Serum TFFs and CA19.9 levels were evaluated via ELISA in comprehensive sample set (n = 362) comprised of independent training and validation sets each containing benign controls (BC), chronic pancreatitis (CP), and various stages of PC. Univariate and multivariate logistic regression and receiver operating characteristic curves (ROC) were used to examine their diagnostic potential both alone and in combination with CA19.9.

Findings

The publicly available datasets and expression analysis revealed significant increased expression of TFF1, TFF2, and TFF3 in human PanINs and PC tissues. Assessment of KC mouse model also suggested upregulated expression of TFFs in PanIN lesions and early stage of PC. In serum analyses studies, TFF1 and TFF2 were significantly elevated in early stages of PC in comparison to benign and CP control group while significant elevation in TFF3 levels were observed in CP group with no further elevation in its level in early stage PC group. In receiver operating curve (ROC) analyses, combination of TFFs with CA19.9 emerged as promising panel for discriminating early stage of PC (EPC) from BC (AUC_{TFF1+TFF2+TFF3+CA19.9} = 0.93) as well as CP (AUC_{TFF1+TFF2+TFF3+CA19.9} = 0.93). Notably, at 90% specificity (desired for blood-based biomarker panel), TFFs combination improved CA19.9 sensitivity by 10% and 25% to differentiate EPC from BC and CP respectively. In an independent blinded validation set, the combination of TFFs and CA19.9 (AUC_{TFF1+TFF2+TFF3+CA19.9} = 0.82) also improved the overall efficacy of CA19.9 (AUC_CA19.9 = 0.66) to differentiate EPC from CP proving unique biomarker capabilities of TFFs to distinguish early stage of this deadly lethal disease.

Interpretation

In silico, tissue and serum analyses validated significantly increased level of all TFFs in precursor lesions and early stages of PC. The combination of TFFs enhanced sensitivity and specificity of CA19.9 to discriminate early stage of PC from benign control and chronic pancreatitis groups.

Proteolytic effects of gingipains on trefoil factor family peptides

OBJECTIVES

The present study was aimed to determine whether trefoil factor family (TFF) peptides which were generally considered to be resistant to proteolysis could be digested by gingipains, a major proteinases produced by Porphyromonas gingivalis.

MATERIALS AND METHODS

Recombinant human TFF1, TFF2, and TFF3 peptides were used as substrates. Gingipains including arginine gingipain (RgpB) and lysine gingipain (Kgp) were used as enzymes. Trypsin was used as a control protease. Matrix-assisted laser desorption/ionization with time-of-flight / time-of-flight (MALDI-TOF/TOF) and liquid chromatography mass spectrometry (LC-MS) were used for analyzing peptide mass signals and amino acid sequences of digested TFF peptides.

RESULTS

MALDI-TOF/TOF analyses demonstrated that Kgp, RgpB, and trypsin were able to cleave TFF1 and TFF2 peptides, resulting in different patterns of digested fragments. However, impurity in recombinant TFF3 peptide substrates affected the interpretations of enzymatic reaction by MALDI-TOF/TOF. LC-MS analyses demonstrated that identified fragments of TFF1, TFF2, and TFF3 from digestion by gingipains were similar to those by trypsin.

CONCLUSIONS

Using MALDI-TOF/TOF and LC-MS, the present study provides new information that gingipains containing trypsin-like activities are able to digest TFF peptides.

CLINICAL RELEVANCE

The proteolytic effects of gingipains on TFF peptides may be responsible for reduction of salivary TFF peptides in chronic periodontitis patients. Further investigations to determine the pathological effects of gingipains on TFF peptides in saliva and periodontal tissues of patients with chronic periodontitis would be of interest.

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.

Combining simple patient-oriented tests with state-of-the-art molecular diagnostics for early diagnosis of cancer

Early diagnosis is an important strategy to improve outcomes from cancer. Oesophageal adenocarcinoma is an example of a cancer that presents late, with very poor outcomes, and for which the presence of the precursor lesion Barrett's oesophagus provides the opportunity to intervene at an early stage. In this review, I describe the challenges in the field and the work that we have done to devise a conceptually novel approach to early diagnosis, using a cell collection device (Cytosponge), coupled with molecular assays. This is a personal perspective in which I also describe the career pathway that led me into academic gastroenterology, and the rewards and challenges of translational research in molecular diagnostics. There are fantastic opportunities for clinicians wishing to pursue academic medicine, because it is a time when massive strides are being made in a whole number of areas; for example: imaging, sequencing technology and targeted therapies. Clinicians who can straddle the laboratory and the clinic are essential, to maximise the progress that can be made for the benefit of patients.

Trefoil factor 3 as a marker of intestinal cell damage during sepsis

Objective

Gastrointestinal dysfunction or gut failure frequently occurs in seriously ill patients and can be responsible for multi-organ failure. Trefoil factor 3 (TFF3) was characterized for its role in reconstitution of an epithelial barrier after mucosal injury in the jejunum. The aims of our study was an analysis of TFF3 levels dynamics in patients with sepsis and the correlation of TFF3 with severity of sepsis and mortality.

Methods

Prospective observational study, a ten days evaluation period in children aged 0–19 years with systemic inflammatory response syndrome or septic state. Blood tests to determine levels of TFF3 were obtained as long as the patient met the criteria for systemic inflammatory response syndrome or sepsis.

Results

Analysis of dynamics revealed steady levels of TFF3 during the 10 day period evaluated. TFF3 levels could not differentiate between various septic conditions in patients until a marked organ dysfunction developed. Higher Area Under Curve was noticed between control group and patients with sepsis. We could not make any strong conclusions based on mortality model.

Conclusions

Levels of TFF3 are elevated in paediatric patients with sepsis through organ dysfunction.

The tumor suppressor gastrokine-1 is expressed in placenta and contributes to the regulation of trophoblast migration

INTRODUCTION

Gastrokine-1 (GKN1) is a secreted auto-/paracrine protein, described to be expressed in the gastric mucosa. In gastric cancers GKN1 expression is commonly down-regulated. While current research focusses on the exploration of tumor-suppressive properties of GKN1 with regard to its potential clinical use in the treatment of gastroenterologic tumor disease, nothing is known about GKN1 expression and function in other organ systems. We investigated GKN1 expression in placental tissue and cells.

MATERIALS AND METHODS

GKN1 was localized using immunohistochemistry in first and third trimester placental tissue, hydatidiform moles and various gestational trophoblastic neoplasias. We determined the expression of GKN1 in immunomagnetic bead-separated term placental cells and in choriocarcinoma cell lines. The role of GKN1 for JEG-3 migration was studied using live cell imaging. E-cadherin, MMP-2 and -9, TIMP-1 and -2, as well as urokinase (uPA) expression levels were determined.

RESULTS

GKN1 is expressed in healthy third trimester placentas. Its expression is specifically limited to the extravillous trophoblast (EVT). GKN1 expression is significantly reduced in choriocarcinoma cell lines and gestational trophoblastic neoplasias. GKN1 attenuates the migration of JEG-3 choriocarcinoma cells in vitro, possibly via AKT-mediated induction of E-cadherin. GKN1 treatment reduced MMP-9 expression in JEG-3.

DISCUSSION

Besides its role in gastric physiology our results clearly indicate regulatory functions of GKN1 in the EVT at the feto-maternal interface during pregnancy. Based on our findings in the JEG-3 choriocarcinoma cell line, an auto-/paracrine role of GKN1 for EVT motility and villous anchorage at the basal plate is conceivable. Thus, the tumor suppressor GKN1 is expressed in placental EVT and might contribute to the regulation of EVT migration/invasion.

Trefoil factor 2 expression and its significance as a predictor of severity of sepsis in children

Intestinal injury significantly contributes to critical illness, sepsis and multiorgan failure. TFF2 (Trefoil Factor 2) is expressed and secreted preferentially by gastric mucous neck cells. TFF2 gene expression is promptly increased after gut injury, and its expression profile broadens to include the regenerative epithelia of virtually the entire gastrointestinal tract. The first objective of our study was an analysis of TFF2 levels dynamics in patients with Systemic Inflammatory Response Syndrome (SIRS) or septic condition during a 5-day period after admission. The second objective was to determine optimal cut-off value and quantify diagnostic characteristics of TFF2 between controls and patients with various septic states. The study included 57 children aged 0-19 years, with expected or proven SIRS and septic condition. The degree of severity was evaluated according to PELOD Score (Pediatric Logistic Organ Dysfunction). Blood samples to determine levels of TFF2 factor were taken during the time patient met the criteria of SIRS or sepsis. Control group samples to determine the serum levels of TFF2 were taken from patients undergoing elective surgery. Analysis of TFF2 levels dynamics revealed that TFF2 levels kept steady state during the 5-day period. Significantly higher levels of TFF2 were in patients with Multiple Organ Dysfunction Syndrome (MODS). The difference was noticed also in ROC analysis.

Trefoil factor: implications for clinical laboratory diagnostics

Trefoil factors (TFF), expressed physiologically in the secretory cells of gastrointestinal mucosa and other mucosal tissues, compose a unique peptide family with important biologic functions. Aberrant expression and/or continued secretion of TFF might exist concurrently with the processes of digestive system inflammation, tumor or other related pathological changes. Previous pathological studies have shown that the abnormal expression of TFF is associated with the prognosis of digestive system diseases. The results obtained from gene expression profiling, tumor secretomics and bioinformatic analysis have positively confirmed that clinical detection of TFF peptides or mRNAs has an excellent diagnostic performance to detect digestive system diseases, especially for the monitoring of recurrence or metastasis of tumors and for the estimation of therapeutic efficacy and prognosis. Therefore, TFF is a potential biomarker for diagnosis, treatment and prognosis of digestive system diseases.

Expression of trefoil factors 1 and 2 in precancerous condition and gastric cancer

AIM: To study the expression of trefoil factor 1 (TFF1) and TFF2 in precancerous condition and gastric cancer and to explore the relationship between TFFs and tumorigenesis, precancerous condition and gastric cancer.

METHODS: The expression of TFF1 and TFF2 was immunohistochemically analyzed in paraffin-embedded samples from 140 patients including 35 cases of chronic superficial gastritis (CSG), 35 cases of gastric ulcer (GU), 35 cases of chronic atrophic gastritis (CAG) and 35 cases of gastric cancer (GC).

RESULTS: TFF1 and TFF2 were located in cytoplasm of gastric mucous cells. In CSG, GU, CAG and GC, the level of TFF1 expression had a decreased tendency (P < 0.05). The expression of TFF2 was higher in GU than in CSG, but the difference was not significant. The expression of TFF2 also had a decreased tendency in GU, CAG, and GC (P < 0.05).

CONCLUSION: The reduced expression of TFF1 and TFF2 in precancerous conditions and gastric cancer may be associated with the proliferation and malignant transformation of gastric mucosa. More investigations are needed to explore the mechanism of TFFs and the relationship between TFFs and gastric cancer.

Relationship between trefoil factor 1 expression and gastric mucosa injuries and gastric cancer

AIM: To determine whether trefoil factor 1 (TFF1) is associated with mucosa healing and carcinoma suppression, we assess the expression of trefoil factor 1 in normal and pathologic gastric mucosa.

METHODS: TFF1 in normal and pathologic gastric mucosa was assessed by immunohistochemical method, and the average positive A was estimated by Motic Images Advanced 3.0 software.

RESULTS: Increased TFF1 was detected in gastritis, gastric ulcer and duodenal ulcer compared with normal mucosa. The same result could be seen in multiple and compound ulcer compared with simple ulcer. There was no significant difference between gastric ulcer and duodenal ulcer, gastritis and simple ulcer respectively. Increased TFF1 was detected in the peripheral mucosa of the gastric adenocarcinoma compared with normal mucosa. The expression of TFF1 in gastric adenocarcinoma was related to the differentiation of adenocarcinoma. The lower the differentiation of adenocarcinoma, the weaker the expression of TFF1. There was no TFF1 expressed in low-differentiated adenocarcinoma. The expression of TFF1 in middle and highly differentiated adenocarcinoma was a little lower than that in normal mucosa. But there was no significant difference. No TFF1 was assessed in esophageal squamous carcinoma and peripheral tissue. There was no significant difference between male and female.

CONCLUSION: The expression of TFF1 was higher in gastritis and peptic ulcer than that in normal mucosa, and was also higher in multiple and compound ulcer than in simple ulcer. It seems that TFF1 plays a role in gastric mucosa protection and epithelial restitution. Increased expression of TFF1 in peripheral tissue suggests that TFF1 is associated with mechanism of carcinoma suppression and differentiation. Decreased expression of TFF1 in carcinoma and its relativity to the differentiation suggests that TFF1 is related to gland and cell destruction of carcinoma.