Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5562051 | Toxicology Letters | 2017 | 36 Pages |
Abstract
Historically, connexin hemichannels have been considered as structural precursors of gap junctions. However, accumulating evidence points to independent roles for connexin hemichannels in cellular signaling by connecting the intracellular compartment with the extracellular environment. Unlike gap junctions, connexin hemichannels seem to be mainly activated in pathological processes. The present study was set up to test the potential involvement of hemichannels composed of connexin32 and connexin43 in acute hepatotoxicity induced by acetaminophen. Prior to this, in vitro testing was performed to confirm the specificity and efficacy of TAT-Gap24 and TAT-Gap19 in blocking connexin32 and connexin43 hemichannels, respectively. Subsequently, mice were overdosed with acetaminophen followed by treatment with TAT-Gap24 or TAT-Gap19 or a combination of both after 1.5Â h. Sampling was performed 3, 6, 24 and 48Â h following acetaminophen administration. Evaluation of the effects of connexin hemichannel inhibition was based on a series of clinically relevant read-outs, measurement of inflammatory cytokines and oxidative stress. Subsequent treatment of acetaminophen-overdosed mice with TAT-Gap19 only marginally affected liver injury. In contrast, a significant reduction in serum alanine aminotransferase activity was found upon administration of TAT-Gap24 to intoxicated animals. Furthermore, co-treatment of acetaminophen-overdosed mice with both peptides revealed an additive effect as even lower serum alanine aminotransferase activity was observed. Blocking of connexin32 or connexin43 hemichannels individually was found to decrease serum quantities of pro-inflammatory cytokines, while no effects were observed on the occurrence of hepatic oxidative stress. This study shows for the first time a role for connexin hemichannels in acetaminophen-induced acute liver failure.
Keywords
FRAP2-APBCBXNAPQIN-acetyl-p-benzoquinone imineAPAPHBSSALTGSSGGSHtransactivator of transcriptionTNFαAdenosine TriphosphateATPAlanine aminotransferaseProbabilityAcetaminopheninflammationTATanalysis of varianceANOVAEnzyme-linked immunosorbent assayELISAtumor necrosis factor αstandard error of the meanHepatotoxicitygap junctionfluorescence recovery after photobleachingHank’s balanced salt solutionSEMHemichannelcarbenoxoloneconnexinGlutathioneglutathione disulfide
Related Topics
Life Sciences
Environmental Science
Health, Toxicology and Mutagenesis
Authors
Michaël Maes, Sara Crespo Yanguas, Joost Willebrords, James L. Weemhoff, Tereza Cristina da Silva, Elke Decrock, Margitta Lebofsky, Isabel Veloso Alves Pereira, Luc Leybaert, Anwar Farhood, Hartmut Jaeschke, Bruno Cogliati, Mathieu Vinken,