title: A myristoylated alanine-rich C kinase substrate-related peptide suppresses cytokine mRNA and protein expression in LPS-activated canine neutrophils.
abstract: Myristoylated alanine-rich C kinase substrate (MARCKS) is a ubiquitously expressed protein kinase C substrate that has emerged as a potential therapeutic target for the amelioration of mucin secretion and inflammation in patients with chronic obstructive pulmonary disease. MARCKS also plays a key role in regulating the adhesion, migration, and degranulation of neutrophils. Moreover, given its biological role in epithelial and immune cells, we hypothesized that MARCKS may play an integral role in cytokine secretion by neutrophils. Because the amino terminus of MARCKS is highly conserved across vertebrate species, we successfully applied the well-characterized human MARCKS inhibitory peptide, myristoylated N-terminal sequence (MANS), to attenuate the function of MARCKS in isolated canine neutrophils. Pretreatment of canine neutrophils with MANS peptide significantly reduced both mRNA and protein expression in a broad range of LPS-induced cytokines, including IL-8, a chemokine (C-X-C motif) ligand-1 orthologue, and TNF-α, in comparison with untreated cells or those treated with a control peptide. This reduction in cytokine expression was observed even when neutrophils were treated with MANS 2 hours after LPS exposure. The observed reduction in cytokine secretion was not attributable to protein retention or cell death, but was associated with reduced cytokine transcript synthesis. These observations identify MARCKS protein as a promising therapeutic target in the treatment of inflammatory diseases or syndromes attributed to neutrophil influx and inflammatory cytokine production, such as sepsis, acute lung injury, and acute respiratory distress syndrome.
authors.affiliation: Comparative Biomedical Sciences Graduate Program, North Carolina State University, Raleigh, NC 27606, USA.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Li
authors.forename: Melissa A
authors.initials: MA
authors.lastname: D'Annibale-Tolhurst
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Adler
authors.forename: Shijing
authors.initials: S
authors.lastname: Fang
authors.forename: Qui
authors.initials: Q
authors.lastname: Yin
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Birkenheuer
authors.forename: Michael G
authors.initials: MG
authors.lastname: Levy
authors.forename: Samuel L
authors.initials: SL
authors.lastname: Jones
authors.forename: Eui Jae
authors.initials: EJ
authors.lastname: Sung
authors.forename: Eleanor C
authors.initials: EC
authors.lastname: Hawkins
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Yoder
authors.forename: Shila K
authors.initials: SK
authors.lastname: Nordone
mesh_terms: D000818:Animals; D004285:Dogs; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism*; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism
chemical_list: D016209:Interleukin-8; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; C000619710:MARCKS protein, human; D008565:Membrane Proteins; D010455:Peptides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D000076250:Myristoylated Alanine-Rich C Kinase Substrate