Clostridium difficile toxin A decreases acetylation of tubulin, leading to microtubule depolymerization through activation of histone deacetylase 6, and this mediates acute inflammation.
Clostridium difficile toxin A is known to cause actin disaggregation through the enzymatic inactivation of intracellular Rho proteins. Based on the rapid and severe cell rounding of toxin A-exposed cells, we speculated that toxin A may be involved in post-translational modification of tubulin, leading to microtubule instability. In the current study, we observed that toxin A strongly reduced α-tubulin acetylation in human colonocytes and mouse intestine. Fractionation analysis demonstrated that toxin A-induced α-tubulin deacetylation yielded monomeric tubulin, indicating the presence of microtubule depolymerization. Inhibition of the glucosyltransferase activity against Rho proteins of toxin A by UDP-2',3'-dialdehyde significantly abrogated toxin A-induced α-tubulin deacetylation. In colonocytes treated with trichostatin A (TSA), an inhibitor of the HDAC6 tubulin deacetylase, toxin A-induced α-tubulin deacetylation and loss of tight junction were completely blocked. Administration of TSA also attenuated proinflammatory cytokine production, mucosal damage, and epithelial cell apoptosis in mouse intestine exposed to toxin A. These results suggest that toxin A causes microtubule depolymerization by activation of HDAC6-mediated tubulin deacetylation. Indeed, blockage of HDAC6 by TSA markedly attenuates α-tubulin deacetylation, proinflammatory cytokine production, and mucosal damage in a toxin A-induced mouse enteritis model. Tubulin deacetylation is an important component of the intestinal inflammatory cascade following toxin A-mediated Rho inactivation in vitro and in vivo.
Nam
Hyo Jung
HJ
From the Department of Life Science, College of Natural Science, Daejin University, Pocheon, Gyeonggido 487-711, Korea.
Kang
Jin Ku
JK
From the Department of Life Science, College of Natural Science, Daejin University, Pocheon, Gyeonggido 487-711, Korea.
Kim
Sung-Kuk
SK
From the Department of Life Science, College of Natural Science, Daejin University, Pocheon, Gyeonggido 487-711, Korea.
Ahn
Keun Jae
KJ
Department of Dermatology and Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul 102-752, Korea.
Seok
Heon
H
School of Nano-Biotechnology and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798, Korea.
Park
Sang Joon
SJ
Department of Veterinary Histology, College of Veterinary Medicine, Kyungpook National University, Taeku 702-701, Korea.
Chang
Jong Soo
JS
From the Department of Life Science, College of Natural Science, Daejin University, Pocheon, Gyeonggido 487-711, Korea.
Pothoulakis
Charalabos
C
Division of Digestive Diseases, David Geffen School of Medicine, UCLA, Los Angeles, California 90095.
Lamont
John Thomas
JT
Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215.
Kim
Ho
H
From the Department of Life Science, College of Natural Science, Daejin University, Pocheon, Gyeonggido 487-711, Korea. Electronic address: hokim@daejin.ac.kr.
D000107:Acetylation / Q000187:drug effects; D000208:Acute Disease; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001427:Bacterial Toxins / Q000633:toxicity*; D002460:Cell Line; D003106:Colon / Q000378:metabolism / Q000473:pathology; D016207:Cytokines / Q000096:biosynthesis; D004751:Enteritis / Q000139:chemically induced / Q000188:drug therapy / Q000378:metabolism*; D004768:Enterotoxins / Q000633:toxicity*; D004789:Enzyme Activation / Q000187:drug effects; D004847:Epithelial Cells / Q000378:metabolism; D000073864:Histone Deacetylase 6; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006655:Histone Deacetylases / Q000378:metabolism*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008870:Microtubules / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D014404:Tubulin / Q000235:genetics / Q000378:metabolism*; D014530:Uridine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D020741:rho GTP-Binding Proteins / Q000378:metabolism
D001427:Bacterial Toxins; D016207:Cytokines; D004768:Enterotoxins; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D014404:Tubulin; C041348:tcdA protein, Clostridium difficile; C012589:trichostatin A; D014530:Uridine Diphosphate; C433811:HDAC6 protein, human; C499033:Hdac6 protein, mouse; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases; D020741:rho GTP-Binding Proteins