3rd International Workshop on Adverse Drug Reactions and Lipodystrophy in HIV 23-26 October 2001, Athens, Greece

DIFFERENTIAL IN VITRO EFFECTS OF INDINAVIR, NELFINAVIR AND AMPRENAVIR ON CELL DIFFERENTIATION, INSULIN SENSITIVITY AND APOPTOSIS IN AN ADAPTED ADIPOSE CELL MODEL: PREVENTIVE IMPACT OF ROSIGLITAZONE

Antiviral Therapy 2001; 6(Suppl. 4):17 (abstract no. 24)

M Caron, M Auclair, M Kornprobst and J Capeau
INSERMU402, Faculté Médecine St-Antoine, Paris, France

BACKGROUND: Protease inhibitors (PIs) used in the treatment of HIV infection have been causally associated with lipodystrophy and insulin resistance both in vivo and in vitro. We previously showed that indinavir impairs adipocyte differentiation and induces insulin resistance through a mechanism that probably involves SREBP-1 nuclear entry.

OBJECTIVE AND METHODS: To examine the relative impact and mechanism of action of indinavir, nelfinavir and amprenavir, on adipogenesis, response to insulin and apoptosis in 3T3-F442A adipocytes adapted to PI studies. Cell differentiation was identified by counting and staining the adipocytes and by the expression of three adipogenic markers. Insulin sensitivity was measured by the activation of MAPK and Akt/PKB. Cell apoptosis was measured by flow cytometry, and by proteolysis of the caspase death substrate PARP.

RESULTS: The three PIs inhibited adipocyte differentiation, with a rank order gradually decreasing from indinavir to nelfinavir and amprenavir. This was shown by the decreased number of newly-formed adipocytes and the altered expression of SREBP-1, PPARγ and C/EBPα. Confocal microscopy showed that indinavir, nelfinavir and amprenavir promoted sequestration of SREPB-1 at the nuclear periphery, but with a decreasing rank order of effect. PI treatment inhibited insulin action on MAP and Akt/PKB kinases with halfmaximally effective concentrations on MAPK of 16, 25 and >100 µM for indinavir, nelfinavir and amprenavir, respectively. Long-term treatment with indinavir and nelfinavir promoted cell apoptosis, as shown by the 23 and 9% increase in cells with fragmented DNA (FACS), and by the proteolysis of PARP. Amprenavir did not induce apoptosis. Finally, the potent PPARγ agonist rosiglitazone, prevents the effect of PIs on cell differentiation, resistance to insulin and programmed cell death.

CONCLUSIONS: Indinavir, nelfinavir and amprenavir affected several adipocyte key functions. Their effects differ in intensity in accordance with preliminary clinical data. This cell system is important to evaluate the effects of other PIs and/or nucleoside reverse transcriptase inhibitors on adipose cell function, thus giving additional information towards the choice of treatment regimens in the clinic. The prevention by rosiglitazone could represent a therapeutic possibility.

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