Anti-atherogenic effects of methotrexate carried by a lipid nanoemulsion that binds to LDL receptors in cholesterol-fed rabbits.
OBJECTIVE
Nanoemulsions (LDE) with a lipid composition resembling that of LDL can concentrate in aortic lesions and when associated with anti-blastic agents, such as paclitaxel or etoposide, decrease atherosclerotic lesions induced in rabbits. Our aim was to test the association of a lipophilic derivative of methotrexate, didodecyl-methotrexate (ddMTX) to LDE on the lesions and on the expression of pro-inflammatory and anti-inflammatory genes.


METHODS
Twenty male New Zealand rabbits were fed 1 % cholesterol diet for 60 days. Starting from day 30, 10 animals were treated with 4 weekly LDE-ddMTX injections (4 mg/kg, I.V.) and 10 with LDE injections (20 mg LDE total lipid mass/kg).


RESULTS
LDE-ddMTX reduced the size of the lesion areas by 65 % and the intima-media ratio by 2-fold. Reduction of intimal macrophage was 67 % and of apoptotic cells was 88 %. Smooth muscle cells migration into the intima was unaffected. LDE-ddMTX treatment diminished metalloproteinase-9 in the intima. In aortas of atherosclerotic rabbits, downregulation of 6 pro-inflammatory genes, TNF-α, MCP-1, IL-1β, IL-18, MMP-9, MMP-12 and upregulation of the anti-inflammatory IL-10 gene were observed. Incubation of LDE-ddMTX with HUVEC cells led to downregulation of TNF-α IL1-β VAP-1, TLR2 and CXCL2.


CONCLUSIONS
LDE-ddMTX is potentially useful to threat atherosclerosis by acting on inflammatory processes which are instrumental in the development of the disease.
Lipid Metabolism Laboratory of the Heart Institute (INCOR) and the Medical School Hospital, São Paulo, SP, Brazil.
Adriana
A
Bulgarelli
Antonio C A
AC
Leite
Adriana A M
AA
Dias
Raul C
RC
Maranhão
D000818:Animals; D001013:Aorta, Thoracic / Q000473:pathology; D050197:Atherosclerosis / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002478:Cells, Cultured; D002791:Cholesterol, Dietary; D016207:Cytokines / Q000235:genetics; D004655:Emulsions; D005786:Gene Expression Regulation / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008297:Male; D053508:Matrix Metalloproteinase 12 / Q000235:genetics; D020780:Matrix Metalloproteinase 9 / Q000235:genetics; D008727:Methotrexate / Q000008:administration & dosage* / Q000737:chemistry; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D011817:Rabbits; D011973:Receptors, LDL / Q000378:metabolism*
D002791:Cholesterol, Dietary; D016207:Cytokines; D004655:Emulsions; D008055:Lipids; D011973:Receptors, LDL; D020780:Matrix Metalloproteinase 9; D053508:Matrix Metalloproteinase 12; D008727:Methotrexate