DFG Research Training Group "TJ-Train" (GRK 2318)
Tight junctions and their proteins
Molecular features and actions in health and disease
& Prof. Dr.
Med. Klinik m.S. Gastroenterologie, Infektiologie & Rheumatologie,
Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin
Epithelial dyspolarity in chronic intestinal inflammation
It is well established that polarity processes in epithelial cells are central to the barrier function these cells impose. A set of polarity complex proteins regulates
the molecular composition of the apical junctional complex that includes the tight junction (TJ) and the adherens junction. We and others have shown that inflammatory conditions induce
dyspolarities in intestinal epithelia that might precede the emergence of barrier defects. Mucosal barrier defects are central to the development of inflammatory bowel diseases (IBD), as Crohn´s
disease (CD) or ulcerative colitis. Thus, we ask for the role of polarity regulation in IBD.
will be the action of interleukin-22 (IL-22), a TH17 cytokine being central in the immune reaction leading to CD and with its receptor being expressed on epithelia. Preliminary data reveal a
strong activity of IL-22 in regulation of epithelial polarity but also in colitis-associated carcinogenesis.
We hypothesize that IBD-associated mucosal inflammation can cause polarity defects of intestinal epithelia.
Thus, we are going to examine polarity complex in IBD and will associate this with determining paracellular permeability. Moreover, we hypothesize that certain cytokines are responsible for this
polarity phenotype by inducing a mis-trafficking of certain polarity proteins. Candidates from preliminary experiments are Par-3, Dlg1 and Crb-3.
Central techniques of this project will include standard molecular biology and cell biology techniques (i.e.
immunostaining, confocal microscopy, Western blotting) as well as physiological techniques to characterize barrier function (using Ussing chambers, i.e. impedance spectroscopy, flux measurements).
The newly developed sandwich assay will be used to spatially correlate polarity defects and barrier leaks. Trafficking and expression of polarity proteins (Pard3, Dlg1, Crb3, PIP-binding moieties)
will be analyzed by live-cell-confocal microscopy using a 3D-cyst model of intestinal Caco-2 cells expressing fluorescently-tagged polarity proteins.
In summary, our specific thesis projects for two doctoral students (1 PhD and 1 MD) are:
(i) Examine establishment and loss of epithelial polarity in Crohn´s disease and ulcerative colitis by combining a
cell culture-based approach and ex vivo experiments using human mucosal tissue samples.
mechanisms leading to defective intracellular trafficking in polarity proteins as Par-3 in intestinal epithelial cells under conditions of inflammation.
PhD doctoral student
Deborah Delbue da Silva
MD doctoral student
If a paper is not accessible, please mail to
Krug SM, Siegmund B, Neurath MF, Becker C (2017)
Mend your fences: The epithelial barrier and its relationship with mucosal immunity in inflammatory bowel disease.
Cell. Mol. Gastroent. Hepatol.
4(1): 33-46 [PubMed] [WebPage]
Richter JF, Schmauder R, Krug SM, Gebert A, Schumann M (2016) A novel method for imaging sites of
paracellular passage of macromolecules in epithelial sheets. J. Control Release 229: 70-79 [PubMed]
Inflamm. Bowel Dis.
21: 1297-1305 [PubMed]
Lissner D, Schumann M, Batra A, Kredel LI, Kühl AA, Erben U, May C, Schulzke JD, Siegmund B (2015) Monocyte
and M1 macrophage-induced barrier defect contributes to chronic intestinal inflammation in IBD.
Kredel LI, Batra A, Stroh T, Kühl AA, Zeitz M, Erben U,
Siegmund B (2013) Adipokines from local fat cells shape the macrophage compartment of the creeping fat in Crohn’s disease.
Batra A, Heimesaat MM, Bereswill S, Fischer A, Glauben R, Kunkel D, Scheffold A, Erben U, Kühl A, Loddenkemper C, Lehr HA,
Schumann M, Schulzke JD, Zeitz M, Siegmund B (2012) Mesenteric fat-control site for bacterial translocation in colitis?
Schumann M, Günzel D, Buergel N, Richter JF, Troeger H, May C, Fromm A,
Sorgenfrei D, Daum S, Bojarski C, Heyman M, Zeitz M, Fromm M, Schulzke JD (2012) Cell polarity-determining proteins Par-3 and PP-1 are involved in epithelial tight junction defects in coeliac
protein mediates regulatory T cell development via induction of the Foxp3 transcription factor.
Schuster M, Glauben R, Plaza-Sirvent C, Schreiber L, Annemann M, Floess S, Kühl AA, Clayton LK, Sparwasser T, Schulze-Osthoff K,
Pfeffer K, Huehn J, Siegmund B, Schmitz I (2012)
Gerling M, Glauben R, Habermann JK, Kühl AA, Loddenkemper C, Lehr HA, Zeitz M, Siegmund B (2011) Characterization of
chromosomal instability in murine colitis-associated colorectal cancer.
Glauben R, Batra A, Stroh T, Erben U, Fedke I, Lehr HA, Leoni F, Mascagni P, Dinarello CA, Zeitz M, Siegmund B (2008)
Histone deacetylases: novel targets for prevention of colitis-associated cancer in mice.
Schumann M, Richter JF, Wedell I, Moos V, Zimmermann-Kordmann M, Schneider T,
Daum S, Zeitz M, Fromm M, Schulzke JD (2008) Mechanisms of epithelial translocation of the alpha(2)-gliadin-33mer in coeliac sprue.
Stroh T, Batra A, Glauben R, Fedke I, Erben U, Kroesen A, Heimesaat MM, Bereswill S, Girardin S, Zeitz M, Siegmund B
(2008) Nucleotide oligonerization domains 1 and 2: regulation of expression and function in preadipocytes.
Am. J. Pathol.
Batra A, Pietsch J, Fedke I, Glauben R, Okur B, Stroh T, Zeitz M,
Siegmund B (2007) Leptin-dependent toll-like receptor expression and responsiveness in preadipocytes and adipocytes.
Siegmund B, Sennello JA, Jones-Carson J, Gamboni-Robertson F, Lehr HA, Batra A, Fedke I, Zeitz M, Fantuzzi G (2004)
Leptin receptor expression on T lymphocyte modulates chronic intestinal inflammation in mice.
Siegmund B, Lehr HA, Fantuzzi G (2002) Leptin: a pivotal mediator of intestinal inflammation in mice.