Inhibitory action of lipopolysaccharide-induced caspase-1 expression by alpha-1-antitrypsin in human trophoblasts

Abstract

s / Placenta 36 (2015) A1eA60 A24 P1.37. INHIBITORY ACTION OF LIPOPOLYSACCHARIDE-INDUCED CASPASE-1 EXPRESSION BY ALPHA-1-ANTITRYPSIN IN HUMAN TROPHOBLASTS Takanori Okubo , Kazuhiro Tamura , Mikihiro Yoshie , Gen Ishikawa , Akihito Nakai , Toshiyuki Takeshita , Takeshi Matsutani , Wakana Ohneda , Naoko Kuwabara , Eiichi Tachikawa . Dept. of Endocrine and Neutral Pharmacology, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan; Division of Reproductive Medicine, Perinatology and Gynecologic Oncology, Nippon Medical School, Tokyo, Japan; Dept. of Gastrointestinal and HepatoBiliary-Pancreatic Surgery, Nippon Medical School, Tokyo, Japan Objective: The trophoblast expresses the Toll-like receptor (TLRs) and Nod-like receptors (NLRs) which control the innate immune system in response to pathogens and metabolic stress. The trophoblast is known to produce pro-inflammatory cytokines and chemokines through TLRs. Alpha-1-antitrypsin (a1-AT), a 52 kDa elastase inhibitor is localized to the syncytiotrophoblasts and this protein has been recently identified as a preeclamsia-related protein. Our recent observations support that a1-AT might be a protective factor for exacerbated inflammation in the reproductive tract. To explore the physiological significance of a1-AT in the placenta, possible regulatory action of a1-AT in the expression of inflammation-related factors was tested using isolated trophoblast. Methods: Human term placentae were collected and the trophoblast. Cells were cultured with both lipopolysaccharide (LPS) and ATP in the presence of a1-AT or under the condition of a1-AT knock-down. The expression of the inflammasome components, prin domain-containing 3 (NLRP3) and the adaptor apoptosis-associated speck-like protein (ASC) as well as TLR4, caspase-1 and IL-1bwas assessed using quantitative real-time RT-PCR. The content of caspase-1 protein was evaluated by western blot. Results: a1-AT treatment exhibited only the tendency to decrease LPS/ ATP-stimulated caspase-1 and IL-1b expression. However, knocking down a1-AT expression significantly enhanced LPS/ATP-stimulated caspase-1 mRNA and protein. The knock-down of a1-AT also stimulated the inflammasomes (NLRP3, ASC) and TLR4 gene transcription. Conclusions: These findings suggest that endogenous a1-AT protein in trophoblasts may attenuate LPS/ATP-induced inflammatory response in part through down-regulation of the inflammasome molecules, supporting the notion the pathophysiological significance of a1-AT at maternalfetal interface and involvement in infection-associated pregnancy complication, like preterm labor. P1.38. RELATIONSHIP BETWEEN PLACENTAL HEPATITIS B VIRUS (HBV) INFECTION WITH TLR3 AND TNF-A EXPRESSION IN GRAVIDAE SCREENED POSITIVE FOR HEPATITIS B VIRUS INFECTION Bo Wah Leung, Terence, Tzu-Hsi Lao. The Chinese University of Hong Kong,