In particular with respect to Barrier-forming and Pore-forming tight junctions comparing to human.
Please take a look at the following
1. Dis Model Mech. 2015 May 8. pii: dmm.019935. [Epub ahead of print]
Glycoprotein A33 deficiency: a new model of impaired intestinal epithelial
barrier function and inflammatory disease.
Williams BB(1), Tebbutt NC(2), Buchert M(1), Putoczki TL(1), Doggett K(3), Bao
S(4), Johnstone CN(5), Masson F(3), Hollande F(6), Burgess AW(1), Scott AM(7),
Ernst M(1), Heath JK(8).
Author information:
(1)The Walter and Eliza Hall Institute and University of Melbourne, Parkville,
Victoria, Australia Department of Medical Biology, University of Melbourne,
Parkville, Victoria, Australia Ludwig Institute for Cancer Research,
Melbourne-Parkville Branch, Victoria, Australia. (2)Ludwig Institute for Cancer
Research, Melbourne-Parkville Branch, Victoria, Australia Ludwig Institute for
Cancer Research, Melbourne-Austin Branch, Victoria, Australia. (3)The Walter and
Eliza Hall Institute and University of Melbourne, Parkville, Victoria, Australia
Department of Medical Biology, University of Melbourne, Parkville, Victoria,
Australia. (4)Discipline of Pathology, School of Medical Science and Bosch
Institute, University of Sydney, NSW, Australia. (5)Ludwig Institute for Cancer
Research, Melbourne-Parkville Branch, Victoria, Australia Trescowthick Research
Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia.
(6)Department of Pathology, University of Melbourne, Parkville, Victoria,
Australia. (7)Ludwig Institute for Cancer Research, Melbourne-Austin Branch,
Victoria, Australia. (8)The Walter and Eliza Hall Institute and University of
Melbourne, Parkville, Victoria, Australia Department of Medical Biology,
University of Melbourne, Parkville, Victoria, Australia Ludwig Institute for
Cancer Research, Melbourne-Parkville Branch, Victoria, Australia
The cells of the intestinal epithelium provide a selectively permeable barrier
between the external environment and internal tissues. The integrity of this
barrier is maintained by tight junctions, specialised cell-cell contacts that
permit the absorption of water and nutrients while excluding microbes, toxins and
dietary antigens. Impairment of intestinal barrier function contributes to
multiple gastrointestinal disorders, including food-hypersensitivity,
inflammatory bowel disease (IBD) and colitis-associated cancer (CAC).
Glycoprotein A33 (GPA33) is an intestinal epithelium-specific cell surface marker
and member of the CTX group of transmembrane proteins. Roles in cell-cell
adhesion have been demonstrated for multiple CTX family members, suggesting a
similar function for GPA33 within the gastrointestinal tract. To test a potential
requirement for GPA33 in intestinal barrier function, we generated Gpa33(-/-)
mice and subjected them to experimental regimens designed to produce food
hypersensitivity, colitis and CAC. Gpa33(-/-) mice exhibit impaired intestinal
barrier function. This was shown by elevated steady-state immunosurveillance in
the colonic mucosa and leakiness to oral TRITC-labelled dextran after short-term
exposure to dextran sodium sulphate (DSS) to injure the intestinal epithelium.
Gpa33(-/-) mice also exhibit rapid onset and reduced resolution of DSS-induced
colitis and a striking increase in the number of colitis-associated tumours
produced by treatment with the colon-specific mutagen azoxymethane (AOM) followed
by two cycles of DSS. In contrast, Gpa33(-/-) mice treated with AOM alone show no
increase in sporadic tumour formation, indicating that their increased tumour
susceptibility is dependent on inflammatory stimuli. Finally, Gpa33(-/-) mice
display hypersensitivity to food allergens, a common co-morbidity in human
patients with IBD. We propose that Gpa33(-/-) mice provide a valuable model to
study the mechanisms linking intestinal permeability and multiple inflammatory
pathologies. Moreover, this model could facilitate pre-clinical studies aimed at
identifying drugs that restore barrier function.
© 2015. Published by The Company of Biologists Ltd.
PMID: 26035389 [PubMed - as supplied by publisher]
2. PLoS One. 2015 May 6;10(5):e0124835. doi: 10.1371/journal.pone.0124835.
eCollection 2015.
Intestinal alkaline phosphatase inhibits the translocation of bacteria of
gut-origin in mice with peritonitis: mechanism of action.
Wang W(1), Chen SW(1), Zhu J(1), Zuo S(1), Ma YY(2), Chen ZY(1), Zhang JL(1),
Chen GW(1), Liu YC(1), Wang PY(1).
Author information:
(1)Department of Surgery, Peking University First Hospital, Xi Shi Ku Street,
Beijing, China. (2)Experimental Animal Center, Peking University First Hospital,
Xi Shi Ku Street, Beijing, China.
Exogenous intestinal alkaline phosphatase (IAP), an enzyme produced endogenously
at the brush edge of the intestinal mucosa, may mitigate the increase in aberrant
intestinal permeability increased during sepsis. The aim of this study was to
test the efficacy of the inhibitory effect of IAP on acute intestinal
inflammation and to study the molecular mechanisms underlying IAP in ameliorating
intestinal permeability. We used an in vivo imaging method to evaluate disease
status and the curative effect of IAP. Two Escherichia coli (E.coli) B21 strains,
carrying EGFP labeled enhanced green fluorescent protein (EGFP) and RFP labeled
red fluorescent protein (RFP), were constructed as tracer bacteria and were
administered orally to C57/B6N mice to generate an injection peritonitis (IP)
model. The IP model was established by injecting inflammatory lavage fluid.
C57/B6N mice bearing the tracer bacteria were subsequently treated with (IP+IAP
group), or without IAP (IP group). IAP was administered to the mice via tail vein
injections. The amount of tracer bacteria in the blood, liver, and lungs at 24 h
post-injection was analyzed via flow cytometry (FCM), in vivo imaging, and
Western blotting. Intestinal barrier function was measured using a flux assay
with the macro-molecule fluorescein isothiocyanate dextran, molecular weight
40kD, (FD40). To elucidate the molecular mechanism underlying the effects of IAP,
we examined the levels of ERK phosphorylation, and the expression levels of
proteins in the ERK-SP1-VEGF and ERK-Cdx-2-Claudin-2 pathways. We observed that
IAP inhibited the expression of Claudin-2, a type of cation channel-forming
protein, and VEGF, a cytokine that may increase intestinal permeability by
reducing the levels of dephosphorylated ERK. In conclusion, exogenous IAP shows a
therapeutic effect in an injection peritonitis model. This including inhibition
of bacterial translocation. Moreover, we have established an imaging methodology
for live-animals can effectively evaluate intestinal permeability and aberrant
bacterial translocation in IP models.
PMCID: PMC4422672
PMID: 25946026 [PubMed - in process]
3. Cell Mol Immunol. 2015 Mar 23. doi: 10.1038/cmi.2015.09. [Epub ahead of print]
Colonization of germ-free mice with a mixture of three lactobacillus strains
enhances the integrity of gut mucosa and ameliorates allergic sensitization.
Kozakova H(1), Schwarzer M(1), Tuckova L(1), Srutkova D(1), Czarnowska E(2),
Rosiak I(2), Hudcovic T(1), Schabussova I(3), Hermanova P(1), Zakostelska Z(1),
Aleksandrzak-Piekarczyk T(4), Koryszewska-Baginska A(4), Tlaskalova-Hogenova
H(1), Cukrowska B(2).
Author information:
(1)Laboratory of Gnotobiology, Institute of Microbiology, Academy of Sciences of
the Czech Republic, Novy Hradek, Czech Republic. (2)Department of Pathology, the
Children's Memorial Health Institute, Warsaw, Poland. (3)Institute of Specific
Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria.
(4)Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw,
Poland.
Increasing numbers of clinical trials and animal experiments have shown that
probiotic bacteria are promising tools for allergy prevention. Here, we analyzed
the immunomodulatory properties of three selected lactobacillus strains and the
impact of their mixture on allergic sensitization to Bet v 1 using a gnotobiotic
mouse model. We showed that Lactobacillus (L.) rhamnosus LOCK0900, L. rhamnosus
LOCK0908 and L. casei LOCK0919 are recognized via Toll-like receptor 2 (TLR2) and
nucleotide-binding oligomerization domain-containing protein 2 (NOD2) receptors
and stimulate bone marrow-derived dendritic cells to produce cytokines in
species- and strain-dependent manners. Colonization of germ-free (GF) mice with a
mixture of all three strains (Lmix) improved the intestinal barrier by
strengthening the apical junctional complexes of enterocytes and restoring the
structures of microfilaments extending into the terminal web. Mice colonized with
Lmix and sensitized to the Bet v 1 allergen showed significantly lower levels of
allergen-specific IgE, IgG1 and IgG2a and an elevated total IgA level in the sera
and intestinal lavages as well as an increased transforming growth factor (TGF)-β
level compared with the sensitized GF mice. Splenocytes and mesenteric lymph node
cells from the Lmix-colonized mice showed the significant upregulation of TGF-β
after in vitro stimulation with Bet v 1. Our results show that Lmix colonization
improved the gut epithelial barrier and reduced allergic sensitization to Bet v
1. Furthermore, these findings were accompanied by the increased production of
circulating and secretory IgA and the regulatory cytokine TGF-β. Thus, this
mixture of three lactobacillus strains shows potential for use in the prevention
of increased gut permeability and the onset of allergies in humans.Cellular &
Molecular Immunology advance online publication, 23 March 2015;
doi:10.1038/cmi.2015.09.
PMID: 25942514 [PubMed - as supplied by publisher]
4. World J Gastroenterol. 2015 Apr 21;21(15):4499-508. doi:
10.3748/wjg.v21.i15.4499.
Intestinal genetic inactivation of caspase-8 diminishes migration of enterocytes.
Kaemmerer E(1), Kuhn P(1), Schneider U(1), Jeon MK(1), Klaus C(1), Schiffer M(1),
Weisner D(1), Liedtke C(1), Jäkel J(1), Kennes LN(1), Hilgers RD(1), Wagner N(1),
Gassler N(1).
Author information:
(1)Elke Kaemmerer, Paula Kuhn, Ursula Schneider, Min Kyung Jeon, Christina Klaus,
Miriam Schiffer, Danika Weisner, Jörg Jäkel, Nikolaus Gassler, Institute of
Pathology, RWTH Aachen University, 52074 Aachen, Germany.
AIM: To verify the hypothesis that caspase-8 (Casp8), which regulates cellular
apoptosis and necroptosis, is critically involved in enterocyte migration.
METHODS: Casp8-silenced Caco2 cells were used in migration assays. In addition,
enterocyte-specific Casp8 heterozygous (Casp8(+/∆int)) or homozygous knockout
mice (Casp8(∆int)) were generated by crossing genetically modified mice carrying
loxP recombination sites in intron 2 and 4 of the murine Casp8 gene with
transgenic animals expressing a cre-transgene under control of the villin
promoter in a pure C57/BL6 genetic background. The nucleoside analog BrdU was
injected i.p. in male Casp8(+/∆int) and Casp8(∆int) animals 4 h, 20 h, or 40 h
before performing morphometric studies. Locations of anti-BrdU-immunostained
cells (cell(max)) in at least 50 hemi-crypts of 6 histoanatomically distinct
intestinal mucosal regions were numbered and extracted for statistical
procedures. For the mice cohort (n = 28), the walking distance of enterocytes was
evaluated from cell(max) within crypt (n = 57), plateau (n = 19), and villus (n =
172) positions, resulting in a total of 6838 observations. Data analysis was
performed by fitting a three-level mixed effects model to the data.
RESULTS: In cell culture experiments with Caco2 cells, Casp8 knockdown efficiency
mediated by RNA interference on Casp8 transcripts was 80% controlled as
determined by Western blotting. In the scratch assay, migration of Casp8-deleted
Caco2 cells was significantly diminished when compared with controls
(Casp8(∆scramble) and Caco2). In BrdU-labeled Casp8(∆int) mice, cell(max)
locations were found along the hemi-crypts in a lower position than it was for
Casp8(+/∆int) or control (cre-negative) animals. Statistical data analysis with a
three-level mixed effects model revealed that in the six different intestinal
locations (distinct segments of the small and large intestine), cell movement
between the three mice groups differed widely. Especially in duodenal
hemi-crypts, enterocyte movement was different between the groups. At 20 h,
duodenal cell(max) location was significantly lower in Casp8(∆int) (25.67 ± 2.49)
than in Casp8(+/∆int) (35.67 ± 4.78; P < 0.05) or control littermates (44.33 ±
0.94; P < 0.01).
CONCLUSION: Casp8-dependent migration of enterocytes is likely involved in
intestinal physiology and inflammation-related pathophysiology.
PMCID: PMC4402296
PMID: 25914458 [PubMed - in process]
5. BMC Microbiol. 2015 Mar 21;15(1):67. doi: 10.1186/s12866-015-0400-1.
Faecalibacterium prausnitzii prevents physiological damages in a chronic
low-grade inflammation murine model.
Martín R(1,)(2,)(3), Miquel S(4,)(5), Chain F(6,)(7), Natividad JM(8), Jury J(9),
Lu J(10), Sokol H(11,)(12,)(13,)(14), Theodorou V(15), Bercik P(16), Verdu
EF(17), Langella P(18,)(19,)(20), Bermúdez-Humarán LG(21,)(22).
Author information:
(1)INRA, Commensal and Probiotics-Host Interactions Laboratory, UMR 1319 Micalis,
F-78350, Jouy-en-Josas, France. [email protected].
(2)AgroParisTech, UMR1319 Micalis, F-78350, Jouy-en-Josas, France.
[email protected]. (3)Farncombe Family Digestive Health Research
Institute, McMaster University, 1200 Main St West, H.Sc. 3N6, Hamilton, Ontario,
Canada. [email protected]. (4)INRA, Commensal and Probiotics-Host
Interactions Laboratory, UMR 1319 Micalis, F-78350, Jouy-en-Josas, France.
[email protected]. (5)AgroParisTech, UMR1319 Micalis, F-78350, Jouy-en-Josas,
France. [email protected]. (6)INRA, Commensal and Probiotics-Host Interactions
Laboratory, UMR 1319 Micalis, F-78350, Jouy-en-Josas, France.
[email protected]. (7)AgroParisTech, UMR1319 Micalis, F-78350,
Jouy-en-Josas, France. [email protected]. (8)Farncombe Family Digestive
Health Research Institute, McMaster University, 1200 Main St West, H.Sc. 3N6,
Hamilton, Ontario, Canada. [email protected]. (9)Farncombe Family
Digestive Health Research Institute, McMaster University, 1200 Main St West,
H.Sc. 3N6, Hamilton, Ontario, Canada. [email protected]. (10)Farncombe Family
Digestive Health Research Institute, McMaster University, 1200 Main St West,
H.Sc. 3N6, Hamilton, Ontario, Canada. [email protected]. (11)INRA,
Commensal and Probiotics-Host Interactions Laboratory, UMR 1319 Micalis, F-78350,
Jouy-en-Josas, France. [email protected]. (12)AgroParisTech, UMR1319 Micalis,
F-78350, Jouy-en-Josas, France. [email protected]. (13)INSERM, Equipe AVENIR
U1057 / UMR CNRS 7203, 75012, Paris, France. [email protected].
(14)Department of Gastroenterology and Nutrition, AP-HP, Hôpital Saint-Antoine
F-75012 and UPMC Univ Paris 06F-75005, Paris, France. [email protected].
(15)INRA, Neuro-Gastroenterology and Nutrition Team, UMR 1331 Toxalim, F-31931,
Toulouse, France. [email protected]. (16)Farncombe Family
Digestive Health Research Institute, McMaster University, 1200 Main St West,
H.Sc. 3N6, Hamilton, Ontario, Canada. [email protected]. (17)Farncombe Family
Digestive Health Research Institute, McMaster University, 1200 Main St West,
H.Sc. 3N6, Hamilton, Ontario, Canada. [email protected]. (18)INRA, Commensal and
Probiotics-Host Interactions Laboratory, UMR 1319 Micalis, F-78350,
Jouy-en-Josas, France. [email protected]. (19)AgroParisTech, UMR1319
Micalis, F-78350, Jouy-en-Josas, France. [email protected].
(20)Farncombe Family Digestive Health Research Institute, McMaster University,
1200 Main St West, H.Sc. 3N6, Hamilton, Ontario, Canada.
[email protected]. (21)INRA, Commensal and Probiotics-Host
Interactions Laboratory, UMR 1319 Micalis, F-78350, Jouy-en-Josas, France.
[email protected]. (22)AgroParisTech, UMR1319 Micalis, F-78350,
Jouy-en-Josas, France. [email protected].
BACKGROUND: The human gut houses one of the most complex and abundant ecosystems
composed of up to 10(13)-10(14) microorganisms. The importance of this intestinal
microbiota is highlighted when a disruption of the intestinal ecosystem
equilibrium appears (a phenomenon called dysbiosis) leading to an illness status,
such as inflammatory bowel diseases (IBD). Indeed, the reduction of the commensal
bacterium Faecalibacterium prausnitzii (one of the most prevalent intestinal
bacterial species in healthy adults) has been correlated with several diseases,
including IBD, and most importantly, it has been shown that this bacterium has
anti-inflammatory and protective effects in pre-clinical models of colitis. Some
dysbiosis disorders are characterized by functional and physiological
alterations. Here, we report the beneficial effects of F. prausnitzii in the
physiological changes induced by a chronic low-grade inflammation in a murine
model. Chronic low-grade inflammation and gut dysfunction were induced in mice by
two episodes of dinitro-benzene sulfonic acid (DNBS) instillations. Markers of
inflammation, gut permeability, colonic serotonin and cytokine levels were
studied. The effects of F. prausnitzii strain A2-165 and its culture supernatant
(SN) were then investigated.
RESULTS: No significant differences were observed in classical inflammation
markers confirming that inflammation was subclinical. However, gut permeability,
colonic serotonin levels and the colonic levels of the cytokines IL-6, INF-γ,
IL-4 and IL-22 were higher in DNBS-treated than in untreated mice. Importantly,
mice treated with either F. prausnitzii or its SN exhibited significant decreases
in intestinal permeability, tissue cytokines and serotonin levels.
CONCLUSIONS: Our results show that F. prausnitzii and its SN had beneficial
effects on intestinal epithelial barrier impairment in a chronic low-grade
inflammation model. These observations confirm the potential of this bacterium as
a novel probiotic treatment in the management of gut dysfunction and low-grade
inflammation.
PMCID: PMC4391109
PMID: 25888448 [PubMed - in process]
6. Antimicrob Agents Chemother. 2015 Mar 30. pii: AAC.04794-14. [Epub ahead of
print]
Berberine blocks the relapse of Clostridium difficile infection in C57BL/6 mice
after vancomycin standard treatment.
Lv Z(1), Peng G(2), Liu W(3), Xu H(4), Su J(5).
Author information:
(1)Clinical Laboratory Center, Beijing Friendship Hospital, Capital Medical
University, Beijing, China. (2)Clinical Laboratory, Beijing Gong An Hospital,
Beijing, China. (3)Department of pathology, Beijing Friendship Hospital, Capital
Medical University, Beijing, China. (4)Animal Center, Beijing Friendship
Hospital, Capital Medical University, Beijing, China. (5)Clinical Laboratory
Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
BACKGROUND: Vancomycin is a preferred antibiotic for treating Clostridium
difficile Infection (CDI) and has been associated with as many as 20% recurrence
of CDI in treated patients. Recent studies have suggested that berberine, an
alternative medical therapy for treating gastroenteritis and diarrhea exhibits
several beneficial effects, including anti-inflammatory responses and restoring
intestinal barrier function. This study investigated therapeutic effects of
berberine on preventing CDI relapse and restoring gut microbiota in a mouse
model.
METHODS: Berberine was administered through gavage to C57BL/6 mice with
established CDI -induced intestinal injury and colitis. Disease activity index
(DAI), mean relative weight, histopathology scores and toxins A&B in feces
samples were measured. Illumina sequencing based analysis of 16SrRNA genes was
used to determine the overall structural change of microbiota in the mice
ileocecus.
RESULTS: Berberine administration significantly promoted the restoration of
intestinal microbiota by inhibiting the expansion of Enterobacteriaceae and
counteracting the side effects of vancomycin treatment. The vancomycin combined
berberine therapy prevented weight loss, improved DAI and histopathology scores,
and effectively decreased mortality rate.
CONCLUSIONS: Berberine prevents CDI from relapsing and significantly improves
survival in the CDI mouse model. Our data indicates that a combination of
berberine and vancomycin is more effective than vancomycin alone for treating
CDI. One of possible mechanisms for preventing CDI relapse by berberine is
through modulating gut microbiota. Although this conclusion is generated in the
case of the mouse model, this combination may represent a novel therapeutic
approach targeting CDI.
Copyright © 2015, American Society for Microbiology. All Rights Reserved.
PMID: 25824219 [PubMed - as supplied by publisher]
7. J Infect Dis. 2015 Mar 24. pii: jiv184. [Epub ahead of print]
Proton-Pump Inhibitor Exposure Aggravates Clostridium difficile-Associated
Colitis: Evidence From a Mouse Model.
Hung YP(1), Ko WC(2), Chou PH(3), Chen YH(3), Lin HJ(1), Liu YH(3), Tsai HW(4),
Lee JC(5), Tsai PJ(6).
Author information:
(1)Department of Internal Medicine, Tainan Hospital, Ministry of Health and
Welfare Department of Internal Medicine Graduate Institute of Clinical Medicine,
National Health Research Institutes, Tainan, Taiwan. (2)Department of Internal
Medicine Center for Infection Control, National Cheng Kung University Hospital
Department of Medicine, National Cheng Kung University Medical College.
(3)Department of Medical Laboratory Science and Biotechnology. (4)Department of
Pathology. (5)Department of Internal Medicine. (6)Department of Medical
Laboratory Science and Biotechnology Center of Infectious Disease and Signaling
Research, National Cheng Kung University.
BACKGROUND: Clostridium difficile is currently the leading cause of infectious
diarrhea in hospitalized patients. In addition to the infection due to toxigenic
C. difficile in the gastrointestinal tract of susceptible hosts, other
predisposing factors for C. difficile infection (CDI) are identified, including
advanced age, a prolonged hospital stay, and use of acid-suppressive drugs. Of
note, exposure to gastric acid-reducing agents, such as H2 blockers and proton
pump inhibitors (PPIs), remains a controversial risk factor, and has been
associated with CDI in some studies but not in others. A mouse model of
antibiotic-associated clostridial colitis was established to examine the role of
PPIs for CDI.
MATERIALS AND METHODS: A mouse model of antibiotic-associated clostridial
colitis was set up. NF-κB reporter mice were used to address the in vivo spatial
and temporal inflammatory patterns of C. difficile-associated colitis. Serum
levels of lipopolysaccharide and dextran-FITC were measured to reflect the
barrier permeability of affected intestines.
RESULTS: Mice with CDI that were exposed to PPI exhibited greater losses of
stool consistency and body and cecal weights than those that were not exposed to
PPI. Further, more neutrophilic infiltrations, epithelial damage, and
inflammatory cytokine expression were noted in colon specimens of the mice with
PPI exposure. More-evident inflammatory responses were detected by in vivo
imaging of NF-κB reporter mice with CDI that were exposed to PPI. Gut barrier
permeability was increased to a greater extent, as reflected by higher serum
levels of lipopolysaccharide and dextran-FITC in mice with CDI that were exposed
to PPI.
CONCLUSIONS: Our mouse model demonstrates that PPI exposure increases the
severity of intestinal inflammation in mice with C. difficile-associated colitis.
© The Author 2015. Published by Oxford University Press on behalf of the
Infectious Diseases Society of America. All rights reserved. For Permissions,
please e-mail: [email protected].
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