Intestinal trefoil factor stimulates mucosal repair processes in vitro and in vivo

Mucosal organs such as the intestine are supported by a rich and complex underlying vasculature. For this reason, the intestine, and particularly barrier-protective epithelial cells, are susceptible to damage related to diminished blood flow and concomitant tissue hypoxia. We sought to identify compensatory mechanisms that protect epithelial barrier during episodes of intestinal hypoxia. Initial studies examining T84 colonic epithelial cells revealed that barrier function is uniquely resistant to changes elicited by hypoxia. A search for intestinal-specific, barrier-protective factors revealed that the human intestinal trefoil factor (ITF) gene promoter bears a previously unappreciated binding site for hypoxia-inducible factor (HIF)-1. Hypoxia resulted in parallel induction of ITF mRNA and protein. Electrophoretic mobility shift assay analysis using ITF-specific, HIF-1 consensus motifs resulted in a hypoxia-inducible DNA binding activity, and loading cells with antisense oligonucleotides directed against the α chain of HIF-1 resulted in a loss of ITF hypoxia inducibility. Moreover, addition of anti-ITF antibody resulted in a loss of barrier function in epithelial cells exposed to hypoxia, and the addition of recombinant human ITF to vascular endothelial cells partially protected endothelial cells from hypoxia-elicited barrier disruption. Extensions of these studies in vivo revealed prominent hypoxia-elicited increases in intestinal permeability in ITF null mice. HIF-1–dependent induction of ITF may provide an adaptive link for maintenance of barrier function during hypoxia.

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Humulene Inhibits Acute Gastric Mucosal Injury by Enhancing Mucosal Integrity

Antioxidants ◽

10.3390/antiox10050761 ◽

2021 ◽

Vol 10 (5) ◽

pp. 761

Author(s):

Dahee Yeo ◽

Su-Jung Hwang ◽

Ye-Seul Song ◽

Hyo-Jong Lee

Keyword(s):

Nuclear Translocation ◽

Adenosine Monophosphate ◽

Gastric Ulcers ◽

Major Constituent ◽

Gastric Injury ◽

Drug Candidate ◽

Trefoil Factor ◽

Expression Levels

This study was designed to determine whether α-humulene, a major constituent in many plants used in fragrances, has a protective role against gastric injury in vivo and in vitro. A rat model of hydrochloric acid (HCl)/ethanol-induced gastritis and human mast cells (HMC-1) were used to investigate the mucosal protective effect of α-humulene. α-Humulene significantly inhibited gastric lesions in HCl/ethanol-induced acute gastritis and decreased gastric acid secretion pyloric ligation-induced gastric ulcers in vivo. In addition, α-humulene reduced the amount of reactive oxygen species and malondialdehyde through upregulation of prostaglandin E2 (PGE2) and superoxide dismutase (SOD). In HMC-1 cells, α-humulene decreased intracellular calcium and increased intracellular cyclic adenosine monophosphate (cAMP) levels, resulting in low histamine levels. α-Humulene also reduced the expression levels of cytokine genes such as interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF) by downregulating nuclear factor-κB (NF-κB) nuclear translocation. Finally, α-humulene upregulated the expression levels of mucin 5AC (Muc5ac), Muc6, trefoil factor 1 (Tff1), trefoil factor 2 (Tff2), and polymeric immunoglobulin receptor (pigr). α-Humulene may attenuate HCl/ethanol-induced gastritis by inhibiting histamine release and NF-κB activation and stimulating antioxidants and mucosal protective factors, particularly Muc5ac and Muc6. Therefore, these data suggest that α-humulene is a potential drug candidate for the treatment of stress-induced or alcoholic gastritis.

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Combined Intestinal Trefoil Factor and Epidermal Growth Factor is Prophylactic against Indomethacin-Induced Gastric Damage in the Rat

Clinical Science ◽

10.1042/cs0880401 ◽

1995 ◽

Vol 88 (4) ◽

pp. 401-403 ◽

Cited By ~ 64

Author(s):

Rebecca Chinery ◽

Raymond J. Playford

Keyword(s):

Growth Factor ◽

Epidermal Growth Factor ◽

Cellular Proliferation ◽

Biological Effects ◽

Trefoil Factor ◽

Intestinal Trefoil Factor ◽

Cell Functions ◽

Epidermal Growth ◽

Gastrointestinal Ulceration

1. The availability of recombinant epidermal growth factor provides a potentially exciting development for the treatment of gastrointestinal ulceration. However, because of its potent mitogenic activity, there is a need for strategies which reduce the dose required. Intestinal trefoil factor stimulates mucosal healing without increasing proliferation. Studies were undertaken to examine the biological effects of rat intestinal trefoil factor and/or human epidermal growth factor upon gastrointestinal epithelial cell functions pertinent to mucosal protection, using two wounding models. 2. The study of epithelial restitution in vitro demonstrated a marked synergistic effect on the rate of migration of the wound edge when intestinal trefoil factor was used in combination with epidermal growth factor. There was no increased cellular proliferation due to the addition of intestinal trefoil factor to the cells when given alone, or to the stimulatory effect of cells treated with epidermal growth factor. In the rat model of gastric ulceration, the presence of both epidermal growth factor and intestinal trefoil factor protected against the development of indomethacin-induced gastric lesions. 3. We conclude that combination therapy of epidermal growth factor with intestinal trefoil factor could provide a more potent, safer approach to the treatment of human gastrointestinal ulceration.

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A pore-forming protein drives macropinocytosis to facilitate toad water maintaining

10.1101/2021.07.31.454564 ◽

2021 ◽

Author(s):

Zhong Zhao ◽

Zhihong Shi ◽

Chenjun Ye ◽

Yun Zhang

Keyword(s):

Environmental Cues ◽

Trefoil Factor ◽

Toad Skin ◽

Hypertonic Stress ◽

Terrestrial Environments ◽

Skin Secretions ◽

Real Challenge ◽

Bombina Maxima

Maintaining water balance is a real challenge for amphibians in terrestrial environments. Our previous studies with toad Bombina maxima discovered a secretory aerolysin family pore-forming protein and trefoil factor complex βγ-CAT, which is assembled under tight regulation depending on environmental cues. Here we report an unexpected role for βγ-CAT in toad water maintaining. Deletion of toad skin secretions, in which βγ-CAT is a major component, increased animal mortality under hypertonic stress. βγ-CAT was constitutively expressed in toad osmoregulatory organs, which was inducible under the variation of osmotic conditions. The protein induced and participated in macropinocytosis in vivo and in vitro. During extracellular hyperosmosis, βγ-CAT stimulated macropinocytosis to facilitate water intake and enhanced exosomes release, which simultaneously regulated aquaporins distribution. Collectively, these findings uncovered that besides membrane integrated aquaporins, a secretory pore-forming protein can facilitate toad water maintaining via macropinocytosis induction and exocytosis modulation, especially in responses to osmotic stress.

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A silencer inhibitor confers specific expression of intestinal trefoil factor in gobletlike cell lines

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.2001.280.6.g1114 ◽

2001 ◽

Vol 280 (6) ◽

pp. G1114-G1123 ◽

Cited By ~ 15

Author(s):

Dai Iwakiri ◽

Daniel K. Podolsky

Keyword(s):

Cell Lines ◽

Goblet Cell ◽

Regulatory Element ◽

Goblet Cells ◽

Transient Transfection ◽

Trefoil Factor ◽

Intestinal Trefoil Factor ◽

Specific Expression ◽

Silencer Element

Intestinal trefoil factor (ITF) is selectively expressed in intestinal goblet cells. Previous studies identified cis-regulatory elements in the proximal promoter of ITF, but these were insufficient to recapitulate the exquisite tissue- and cell-specific expression of native ITF in vivo. Preliminary studies suggested that goblet cell-specific expression of murine ITF requires elements far upstream that include a silencer element that effectively prevents ITF expression in non-goblet cells. Transient transfection studies using native or mutant ITF 5′-flanking sequences identified a region that restores expression in goblet cells. This element, designated goblet cell silencer inhibitor (GCSI) element, enables human and murine goblet cell-like cell lines to override the silencing effect of more proximal elements. The GCSI has no intrinsic enhancer activity and regulates expression only when the silencer element is present. Ligation of GCSI and silencer elements to sucrase-isomaltase conferred goblet cell-specific expression. Goblet cells but not non-goblet cells possess a nuclear protein that binds to the GCSI regulatory element (GCSI binding protein; GCSI-BP). Both transient transfection and gel mobility shift assay studies localize the GCSI and GCSI-BP to −2216 to −2204. We conclude that goblet cell-specific transcription of ITF in vivo depends on a regulatory element designated GCSI.

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Epithelial CD47 is critical for mucosal repair in the murine intestine in vivo

Nature Communications ◽

10.1038/s41467-019-12968-y ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 6

Author(s):

Michelle Reed ◽

Anny-Claude Luissint ◽

Veronica Azcutia ◽

Shuling Fan ◽

Monique N. O’Leary ◽

...

Keyword(s):

Wound Healing ◽

Epithelial Cell ◽

Wound Repair ◽

Inflammatory Responses ◽

Critical Role ◽

Primary Cultures ◽

Intestinal Barrier ◽

Mucosal Repair

Abstract CD47 is a ubiquitously expressed transmembrane glycoprotein that regulates inflammatory responses and tissue repair. Here, we show that normal mice treated with anti-CD47 antibodies, and Cd47-null mice have impaired intestinal mucosal wound healing. Furthermore, intestinal epithelial cell (IEC)-specific loss of CD47 does not induce spontaneous immune-mediated intestinal barrier disruption but results in defective mucosal repair after biopsy-induced colonic wounding or Dextran Sulfate Sodium (DSS)-induced mucosal damage. In vitro analyses using primary cultures of CD47-deficient murine colonic IEC or human colonoid-derived IEC treated with CD47-blocking antibodies demonstrate impaired epithelial cell migration in wound healing assays. Defective wound repair after CD47 loss is linked to decreased epithelial β1 integrin and focal adhesion signaling, as well as reduced thrombospondin-1 and TGF-β1. These results demonstrate a critical role for IEC-expressed CD47 in regulating mucosal repair and raise important considerations for possible alterations in wound healing secondary to therapeutic targeting of CD47.

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Trefoil Factor Family (TFF) Peptides and their Different Roles in the Mucosal Innate Immune Defense and More: An Update

Current Medicinal Chemistry ◽

10.2174/0929867328666210215114140 ◽

2021 ◽

Vol 28 ◽

Author(s):

Werner Hoffmann

Keyword(s):

Cysteine Residue ◽

Immune Defense ◽

Innate Immune ◽

Molecular Forms ◽

Trefoil Factor ◽

Gastric Mucus ◽

Innate Immune Defense ◽

Trefoil Factor Family

: Mucous epithelia are protected by complex mucus barrier layers, which are part of the innate immune defense. Trefoil factor family peptides TFF1, TFF2, and TFF3 have lectin activities and are predominantly co-secreted together with mucins from these epithelia. TFF1 and TFF2 are mainly expressed in the gastric mucosa; whereas TFF3 is rather widely secreted from most mucous epithelia and their glands. TFF1 and TFF3 consist of a single TFF domain and an additional free 7th cysteine residue; whereas TFF2 contains two TFF domains. Systematic analyses of the molecular forms of TFFs gave new insights into their diverse molecular functions. TFF1 mainly exists as a monomer with an unusual free thiol group and only minor amounts form a disulfide linked homodimer as well as heterodimers with gastrokine-2 and IgG-Fc-binding protein (FCGBP). TFF3 mainly forms a heterodimer with FCGBP in vivo, but binds also Deleted in Malignant Brain Tumors/gp340 (DMBT1gp340) in vitro. In contrast, TFF2 binds as a lectin to a conserved O-linked carbohydrate moiety of the mucin MUC6. Both FCGBP and DMBT1gp340 are secreted from most mucous epithelia and their glands and are involved in mucosal innate immunity. Thus, a new picture emerged pointing to functions of TFF3-FCGBP (and TFF1-FCGBP) for mucosal innate immune defense, e.g. supporting the clearing of microorganisms. Such a function could be well be supported by DMBT1gp340. In contrast, the TFF2/MUC6 complex probably stabilizes physically the inner adherent gastric mucus layer. Furthermore, there are indications that TFF3-FCGBP might play also a role in blood vessels.

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Impact of G-Quadruplexes on the Regulation of Genome Integrity, DNA Damage and Repair

Biomolecules ◽

10.3390/biom11091284 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1284

Author(s):

Anzhela V. Pavlova ◽

Elena A. Kubareva ◽

Mayya V. Monakhova ◽

Maria I. Zvereva ◽

Nina G. Dolinnaya

Keyword(s):

Dna Damage ◽

Genome Instability ◽

Critical Role ◽

Dna Lesions ◽

Genome Integrity ◽

Dna Breaks ◽

Dna Damage And Repair ◽

Repair Processes

DNA G-quadruplexes (G4s) are known to be an integral part of the complex regulatory systems in both normal and pathological cells. At the same time, the ability of G4s to impede DNA replication plays a critical role in genome integrity. This review summarizes the results of recent studies of G4-mediated genomic and epigenomic instability, together with associated DNA damage and repair processes. Although the underlying mechanisms remain to be elucidated, it is known that, among the proteins that recognize G4 structures, many are linked to DNA repair. We analyzed the possible role of G4s in promoting double-strand DNA breaks, one of the most deleterious DNA lesions, and their repair via error-prone mechanisms. The patterns of G4 damage, with a focus on the introduction of oxidative guanine lesions, as well as their removal from G4 structures by canonical repair pathways, were also discussed together with the effects of G4s on the repair machinery. According to recent findings, there must be a delicate balance between G4-induced genome instability and G4-promoted repair processes. A broad overview of the factors that modulate the stability of G4 structures in vitro and in vivo is also provided here.

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