title: Cytokine-like Activity of Liver Type Fatty Acid Binding Protein (L-FABP) Inducing Inflammatory Cytokine Interleukin-6.
abstract: It has been reported that fatty acid binding proteins (FABPs) do not act only as intracellular mediators of lipid responses but also have extracellular functions. This study aimed to investigate whether extracellular liver type (L)-FABP has a biological activity and to determined serum L-FABP levels in patients with end-stage renal disease (ESRD). We isolated L-FABP complementary deoxyribonucleic acid (cDNA) from the Huh7 human hepatocarcinoma cell line and expressed the recombinant L-FABP protein inEscherichia coli. A549 lung carcinoma and THP-1 monocytic cells were stimulated with the human recombinant L-FABP. Human whole blood cells were also treated with the human recombinant L-FABP or interleukin (IL)-1α. IL-6 levels were measured in cell culture supernatants using IL-6 enzyme-linked immunosorbent assay (ELISA). Human recombinant L-FABP induced IL-6 in a dose-dependent manner in A549, THP-1 cells, and whole blood cells. The blood samples of healthy volunteers and patients with ESRD were taken after an overnight fast. The serum levels of L-FABP in healthy volunteers and ESRD patients were quantified with L-FABP ELISA. The values of L-FABP in patients with ESRD were significantly lower than those in the control group. Our results demonstrated the biological activity of L-FABP in human cells suggesting L-FABP can be a mediator of inflammation.
authors: Division of Nephrology, Department of Internal Medicine, Jeju National University School of Medicine, Jeju 63243, Korea.; Department of Medicine, University of Colorado Denver, Aurora, Colorado 80045, USA.
authors: Hyunwoo
authors: H
authors: Kim
authors: Laboratory of Cytokine Immunology, Department of Biomedical Science and Technology, Konkuk University, Seoul 05029, Korea.
authors: Gaae
authors: G
authors: Gil
authors: Laboratory of Cytokine Immunology, Department of Biomedical Science and Technology, Konkuk University, Seoul 05029, Korea.; YbdYbiotech research center, Seoul 08589, Korea.
authors: Siyoung
authors: S
authors: Lee
authors: Laboratory of Cytokine Immunology, Department of Biomedical Science and Technology, Konkuk University, Seoul 05029, Korea.; College of Veterinary Medicine, Konkuk University, Seoul 05029, Korea.
authors: Areum
authors: A
authors: Kwak
authors: Laboratory of Cytokine Immunology, Department of Biomedical Science and Technology, Konkuk University, Seoul 05029, Korea.; College of Veterinary Medicine, Konkuk University, Seoul 05029, Korea.
authors: Seunghyun
authors: S
authors: Jo
authors: Laboratory of Cytokine Immunology, Department of Biomedical Science and Technology, Konkuk University, Seoul 05029, Korea.
authors: Ensom
authors: E
authors: Kim
authors: Laboratory of Cytokine Immunology, Department of Biomedical Science and Technology, Konkuk University, Seoul 05029, Korea.
authors: Tam T
authors: TT
authors: Nguyen
authors: Laboratory of Cytokine Immunology, Department of Biomedical Science and Technology, Konkuk University, Seoul 05029, Korea.
authors: Sinae
authors: S
authors: Kim
authors: Laboratory of Cytokine Immunology, Department of Biomedical Science and Technology, Konkuk University, Seoul 05029, Korea.; College of Veterinary Medicine, Konkuk University, Seoul 05029, Korea.
authors: Hyunjhung
authors: H
authors: Jhun
authors: Division of Nephrology, Department of Internal Medicine, Jeju National University School of Medicine, Jeju 63243, Korea.
authors: Somi
authors: S
authors: Kim
authors: Division of Nephrology, Department of Internal Medicine, Jeju National University School of Medicine, Jeju 63243, Korea.
authors: Miyeon
authors: M
authors: Kim
authors: Department of Medicine, Pusan Paik Hospital, College of Medicine, Inje University, Busan 47392, Korea.
authors: Youngmin
authors: Y
authors: Lee
authors: Laboratory of Cytokine Immunology, Department of Biomedical Science and Technology, Konkuk University, Seoul 05029, Korea.; College of Veterinary Medicine, Konkuk University, Seoul 05029, Korea.
authors: Soohyun
authors: S
authors: Kim
keywords: End stage renal disease; Liver type fatty acid binding protein; Whole blood cells