10th International Workshop on Adverse Drug Reactions and Lipodystrophy in HIV 6-8 November 2008, London, UK

COMPARISON OF THE EFFECTS OF LOPINAVIR/RITONAVIR AND EFAVIRENZ ON GENE EXPRESSION AND DIFFERENTIATION OF HUMAN ADIPOCYTES

Antiviral Therapy 2008; 13(Suppl. 4):A23 (abstract no. P-01)

J Diaz-Delfin¹, JM Gallego-Escuredo¹, M Milanski¹, JC Domingo¹, MM Gutierrez², MG Mateo², P Domingo², M Giralt¹ and F Villarroya^1
1Deptatamento de Bioquimica i Biologia Molecular, Universitat de Barcelona, Barcelona, Spain; ²Hospital de la Santa Creu I Sant Pau, Barcelona, Spain

AIM: Lopinavir/ritonavir and efavirenz are drugs of choice for initial antiretroviral therapy. Several reports indicate deleterious effects of these drugs on adipocytes in vitro as well as their potential contribution to lipodystrophy and metabolic alterations in HIV type-1-infected, highly active antiretroviral therapy (HAART)-treated patients. Our objective was to perform a parallel comparative assessment of the effects of the lopinavir/ritonavir (4:1) combination commonly used in antiretroviral treatment with respect to efavirenz on differentiation and expression of marker genes of adipogenesis, inflammation, mitochondrial toxicity and endoplasmic reticulum (ER) stress in human adipocytes in culture.

METHODS: Human adipocytes were differentiated in primary culture from precursor cells obtained from liposuction from healthy individuals. We determined the effects of exposure to equivalent concentrations of lopinavir/ritonavir (4:1) and efavirenz of pre-adipocytes during their 10-day process of differentiation into adipocytes. The same comparison was performed by studying the effects of 24 h exposure of already differentiated human adipocytes to these drugs. Acquisition of adipocyte morphology, lactate release to the medium (Roche) and changes in mRNA levels for selected genes (TaqMan; Applied Biosystems) were determined.

RESULTS: Lopinavir/ritonavir (4:1) caused a dose–response impairment of morphological human adipocyte differentiation that was, however, less pronounced than that caused by equivalent concentrations of efavirenz. This was paralleled by a dose–response reduction in transcripts of marker genes of adipogenesis (PPARγ, adiponectin and lipoprotein lipase), but always to a lesser extent for lopinavir/ritonavir (4:1) than for equivalent concentrations of efavirenz. Conversely, MCP-1 mRNA levels were induced both by lopinavir/ ritonavir (4:1) and efavirenz, but to a higher extent for efavirenz. Neither the levels of transcripts encoding mitochondrial proteins (COII mRNA and COIV mRNA) nor lactate release to the medium were altered by the drugs. In differentiated adipocytes, lopinavir/ritonavir (4:1) caused a dose-dependent reduction of adipogenesis-related gene expression (that is, 47% reduction of adiponectin mRNA at 4 µM lopinavir/ritonavir (4:1) that was milder than that elicited by efavirenz (85% reduction in adiponectin mRNA at 4 µM efavirenz). In this experimental setting, analysis of GRP78 mRNA levels, the marker of ER stress, was performed. Exposure of adipocytes to lopinavir/ritonavir (4:1) and to efavirenz caused an increase of GRP78 mRNA levels, which was more intense for equivalent concentrations of lopinavir/ritonavir (4:1).

CONCLUSIONS: Exposure of adipocytes to the lopinavir/ritonavir combination used in HAART impairs adipogenesis and increases inflammation-related gene expression, but to a lesser extent than equivalent amounts of efavirenz. Mitochondrial toxicity is not involved in these effects. Preferential induction of ER stress by lopinavir/ritonavir (4:1) does not appear to be associated with worsening the effects of this drugs combination on adipocyte biology with respect to efavirenz.

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2008-11-06
P-01

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