Anti-EDEM1 monoclonal antibody, clone 3E4

Backgrounds 3,4-Dichloroaniline (3,4-DCA) is a transformation product of herbicides that is commonly used as a reference in developmental toxicity studies (OECD TG 236) (Bonnet et al. in Environ Toxicol 22:78-91, 2007). However, the mechanisms underlying 3,4-DCA-induced hepatotoxicity are not well known. Methods We exposed zebrafish larvae at 72 hpf to 3,4-DCA for 3 days and observed lipid accumulation in liver treated with 10-mu M 3,4-DCA using oil red O staining. Subsequently, we performed qRT-PCR analysis to determine the genes involved in the observed lipid accumulation. Results We found that genes related to lipogenesis (srebp1, ppar gamma, lipin1, and scd1) and ER stress (bip, atf4, ddit3, dnajc3, and edem1) were significantly upregulated. In addition, we found that ROS generation increased in the larvae treated with 10-mu M 3,4-DCA. Moreover, glutathione-S-transferase activity in these larvae was increased by 3,4-DCA in a dose-dependent manner, and the expression of the inflammation marker il-1 beta increased. Conclusion Our results indicated that exposure to 3,4-DCA induced fatty liver in zebrafish larvae and that this, in association with additional factors such as ER stress response, can promote liver damage. We accordingly suggest that 3,4-DCA could be used to induce fatty liver in zebrafish larvae.

Alpha-1-antitrypsin deficiency (AATD) is an inherited disease characterized by emphysema and liver disease. AATD is most often caused by a single amino acid substitution at amino acid 342 in the mature protein, resulting in the Z mutation of the alpha-1-antitrypsin gene (ZAAT). This substitution is associated with misfolding and accumulation of ZAAT in the endoplasmic reticulum(ER) of hepatocytes and monocytes, causing a toxic gain of function. Retained ZAAT is eliminated by ER-associated degradation and autophagy. We hypothesized that alpha-1-antitrypsin (AAT)-interacting proteins play critical roles in quality control of human AAT. Using co-immunoprecipitation, we identified ERdj3, an ER-resident Hsp40 family member, as a part of the AAT trafficking network. Depleting ERdj3 increased the rate of ZAAT degradation in hepatocytes by redirecting ZAAT to the ER calreticulin-EDEM1 pathway, followed by autophagosome formation. In the Huh7.5 cell line, ZAATER clearance resulted from enhancing ERdj3-mediated ZAAT degradation by silencing ERdj3 while simultaneously enhancing autophagy. In this context, ERdj3 suppression may eliminate the toxic gain of function associated with polymerization of ZAAT, thus providing a potential new therapeutic approach to the treatment of AATD-related liver disease. (C) 2017 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals Inc.