TY - JOUR
T1 - Impact of cell-penetrating peptides (CPPs) melittin and Hiv-1 Tat on the enterocyte brush border using a mucosal explant system
AU - Danielsen, E. Michael
AU - Hansen, Gert H.
PY - 2018
Y1 - 2018
N2 - “Cell penetrating peptides” (CPPs) are natural or synthetic peptides with the ability to interact with cell membranes in order to enter cells and/or deliver cargo. They attract considerable interest as permeation enhancers for oral delivery of therapeutic drugs with poor bioavailability, such as proteins or DNA. A main barrier is the intestinal epithelium where passage needs to proceed through a paracellular -and/or a transcellular pathway. Using an organ cultured mucosal explant model system and a selection of fluorescent polar -and lipophilic tracers, the aim of the present study was to investigate the interaction of two CPPs, melittin and Hiv-1 Tat, with the enterocyte brush border. Melittin belongs to the amphipathic class of CPPs, and within 0.5–1 h it bound to, and penetrated, the enterocyte brush border, causing leakage into the cytosol and increased paracellular passage into the lamina propria. Surprisingly, melittin also abolished endocytosis of tracers from the brush border into early endosomes in the terminal web region (TWEEs), excluding any permeation enhancing effect via such an uptake mechanism. Electron microscopy revealed that melittin caused an elongation of the brush border microvilli and a reduction in their diameter. HIV-1 Tat is a cationic CPP that is internalized by cells due to a sequence, mainly of arginines, from residue 49 to 57, and a peptide containing this sequence permeabilized enterocytes to a polar tracer by a leakage into the cytosol. In conclusion, the CPPs studied acted by causing leakage of tracers into the enterocyte cytosol, not by inducing endocytosis.
AB - “Cell penetrating peptides” (CPPs) are natural or synthetic peptides with the ability to interact with cell membranes in order to enter cells and/or deliver cargo. They attract considerable interest as permeation enhancers for oral delivery of therapeutic drugs with poor bioavailability, such as proteins or DNA. A main barrier is the intestinal epithelium where passage needs to proceed through a paracellular -and/or a transcellular pathway. Using an organ cultured mucosal explant model system and a selection of fluorescent polar -and lipophilic tracers, the aim of the present study was to investigate the interaction of two CPPs, melittin and Hiv-1 Tat, with the enterocyte brush border. Melittin belongs to the amphipathic class of CPPs, and within 0.5–1 h it bound to, and penetrated, the enterocyte brush border, causing leakage into the cytosol and increased paracellular passage into the lamina propria. Surprisingly, melittin also abolished endocytosis of tracers from the brush border into early endosomes in the terminal web region (TWEEs), excluding any permeation enhancing effect via such an uptake mechanism. Electron microscopy revealed that melittin caused an elongation of the brush border microvilli and a reduction in their diameter. HIV-1 Tat is a cationic CPP that is internalized by cells due to a sequence, mainly of arginines, from residue 49 to 57, and a peptide containing this sequence permeabilized enterocytes to a polar tracer by a leakage into the cytosol. In conclusion, the CPPs studied acted by causing leakage of tracers into the enterocyte cytosol, not by inducing endocytosis.
KW - Brush border
KW - Cell penetrating peptides (CPPs)
KW - Enterocyte
KW - HIV-1 Tat
KW - Melittin
KW - Small intestine
U2 - 10.1016/j.bbamem.2018.05.015
DO - 10.1016/j.bbamem.2018.05.015
M3 - Journal article
C2 - 29856994
AN - SCOPUS:85047760327
SN - 0005-2736
VL - 1860
SP - 1589
EP - 1599
JO - Biochimica et Biophysica Acta - Biomembranes
JF - Biochimica et Biophysica Acta - Biomembranes
IS - 8
ER -
