Milk fat globule epidermal growth factor-factor 8-derived peptide attenuates organ injury and improves survival in sepsis.
BACKGROUND
Sepsis involves overwhelming inflammatory responses with subsequent immune-suppression that can lead to multiple organ dysfunction and ultimately death. Milk fat globule epidermal growth factor-factor 8 (MFG-E8) is a secretory protein found to have multiple biological activities against autoimmune and inflammatory diseases. MFG-E8 contains an Arg-Gly-Asp (RGD) motif involved in cell-cell and cell-matrix interactions. In sepsis, excessive neutrophils migration through endothelial cells and matrix to sites of inflammation results in organ damage. We hypothesized that MFG-E8-derived short peptides (MSP) flanking its RGD motif could provide protection against organ injury in sepsis.


METHODS
The differentiated human neutrophil-like HL-60 cells (dHL60) were incubated with a series of peptides flanking the RGD motif of human MFG-E8 for a cell adhesion assay to fibronectin or human pulmonary artery endothelial cells (PAECs). For the induction of sepsis, male C57BL/6 mice (20-25 g) were subjected to cecal ligation and puncture (CLP). Peptide MSP68 (1 mg/kg body weight) or normal saline (vehicle) was injected intravenously at 2 h after CLP. Blood and tissue samples were collected at 20 h after CLP for various measurements.


RESULTS
After screening, peptide MSP68 (VRGDV) had the highest inhibition of dHL-60 cell adhesion to fibronectin by 55.8 % and to PAEC by 67.7 %. MSP68 treatment significantly decreased plasma levels of organ injury marker AST by 37.1 % and the proinflammatory cytokines IL-6 and TNF-α by 61.9 % and 22.1 %, respectively after CLP. MSP68 improved the integrity of microscopic architectures, decreased IL-6 levels in the lungs by 85.1 %, and reduced apoptosis. MSP68 treatment also significantly reduced the total number of neutrophil infiltration by 61.9 % and 48.3 % as well as MPO activity by 40.8 % and 47.3 % in the lungs and liver, respectively, after CLP. Moreover, the number of bacteria translocated to mesenteric lymph nodes was decreased by 57 % with MSP68 treatment. Finally, the 10-day survival rate was increased from 26 % in the vehicle group to 58 % in the MSP68-treated group.


CONCLUSIONS
MSP68 effectively inhibits excessive neutrophils infiltrating to organs, leading to moderate attenuation of organ injury and significantly improved survival in septic mice. Thus, MSP68 may be a potential therapeutic agent for treating sepsis.
Department of Surgery, Hofstra North Shore-LIJ School of Medicine, Manhasset, NY, 11030, USA. wlyang@nshs.edu.|Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Dr., Manhasset, NY, 11030, USA. wlyang@nshs.edu.
Weng-Lang
WL
Yang
Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Dr., Manhasset, NY, 11030, USA. asharma11@nshs.edu.
Archna
A
Sharma
Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Dr., Manhasset, NY, 11030, USA. fzhang1@nshs.edu.
Fangming
F
Zhang
Department of Surgery, Hofstra North Shore-LIJ School of Medicine, Manhasset, NY, 11030, USA. Shingo.matsuo123@gmail.com.|Present address: Department of Surgery II, Tokyo Women's Medical University, Tokyo, Japan. Shingo.matsuo123@gmail.com.
Shingo
S
Matsuo
Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Dr., Manhasset, NY, 11030, USA. zwang@nshs.edu.
Zhimin
Z
Wang
Laboratory for Emergency Medicine, The Feinstein Institute for Medical Research, Manhasset, NY, 11030, USA. hwang@nshs.edu.
Haichao
H
Wang
Department of Surgery, Hofstra North Shore-LIJ School of Medicine, Manhasset, NY, 11030, USA. pwang@nshs.edu.|Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Dr., Manhasset, NY, 11030, USA. pwang@nshs.edu.
Ping
P
Wang
D000818:Animals; D000954:Antigens, Surface / Q000008:administration & dosage / Q000627:therapeutic use*; D004195:Disease Models, Animal; D018922:HL-60 Cells; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008894:Milk Proteins / Q000008:administration & dosage / Q000627:therapeutic use*; D009102:Multiple Organ Failure / Q000209:etiology / Q000517:prevention & control*; D020556:Neutrophil Infiltration / Q000187:drug effects; D018805:Sepsis / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology
D000954:Antigens, Surface; C098942:MFGE8 protein, human; D008894:Milk Proteins