Profile of stress and toxicity gene expression in human hepatic cells treated with Efavirenz
ABSTRACT Hepatic toxicity and metabolic disorders are major adverse effects elicited during the pharmacological treatment of the human immunodeficiency virus (HIV) infection. Efavirenz (EFV), the most widely used non-nucleoside reverse transcriptase inhibitor (NNRTI), has been associated with these events, with recent studies implicating it in stress responses involving mitochondrial dysfunction and oxidative stress in human hepatic cells. To expand these findings, we analyzed the influence of EFV on the expression profile of selected stress and toxicity genes in these cells. Significant up-regulation was observed with Cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1), which indicated metabolic stress. Several genes directly related to oxidative stress and damage exhibited increased expression, including Methalothionein 2A (MT2A), Heat shock 70kDa protein 6 (HSPA6), Growth differentiation factor 15 (GDF15) and DNA-damage-inducible transcript 3 (DDIT3). In addition, Early growth response protein 1 (EGR1) was enhanced, whereas mRNA levels of the inflammatory genes Chemokine (C-X-C motif) ligand 10 (CXCL10) and Serpin peptidase inhibitor (nexin, plasminogen activator inhibitor type 1), member 1 (SERPINE1) decreased and increased, respectively. This profile of gene expression supports previous data demonstrating altered mitochondrial function and presence of oxidative stress/damage in EFV-treated hepatic cells, and may be of relevance in the search for molecular targets with therapeutic potential to be employed in the prevention, diagnosis and treatment of the hepatic toxicity associated with HIV therapy.
- [Show abstract] [Hide abstract]
ABSTRACT: Background and PurposeThe non-nucleoside analog reverse transcriptase inhibitor Efavirenz (EFV) has been associated with hepatic toxicity and metabolic disturbances. Although the mechanisms involved are not clear, recent evidence has pinpointed a specific mitochondrial action of EFV accompanied by ER-stress/UPR induction in human hepatic cells. The aim of this study was to further investigate the implication of this organelle by evaluating EFV action on cells lacking functional mitochondria (rho°), and comparing it with that of the typical mitotoxic agent, rotenone (Rot), a standard Complex I inhibitor, and the ER-stress inductor thapsigargin (TG).Experimental approachHep3B rho+ and rho° cells were treated with clinically relevant concentrations of EFV, then mitochondrial function and cytotoxicity were studied using standard cell biology techniques.Key resultsEFV-treated rho° cells exhibited a substantial reduction in parameters indicative of mitochondrial interference, such as increased superoxide production, mitochondrial mass/morphology alterations and enhanced expression of LONP, a highly conserved mitochondrial protease. In line with these results, the cytotoxic effect (cell number, chromatin condensation, cell cycle alterations and induction of apoptosis) of EFV was less pronounced in Hep3B respiration-depleted cells than in WT cells. The response of EFV reveals both similarities and differences with those of two distinct mitochondrial stressors, TG and Rot.Conclusions and ImplicationsCells lacking normal mitochondria (rho°) are less vulnerable to EFV. Our results provide further evidence that the hepatic damage induced by EFV involves acute interference with mitochondria and extend our knowledge of the mitochondria/ER interplay that takes place upon a stress stimulus.British Journal of Pharmacology 11/2014; 172(7). DOI:10.1111/bph.13018 · 4.99 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: The non-nucleoside reverse transcriptase inhibitor efavirenz is a widely prescribed antiretroviral drug used in combined antiretroviral therapy. Despite being an essential and life-saving medication, the required lifelong use of HIV drugs has been associated with a variety of adverse effects, including disturbances in lipid metabolism and increased cardiovascular risk. Efavirenz belongs to those HIV drugs for which cardiovascular and endothelial dysfunctions have been reported. It is here shown that elevated concentrations of efavirenz can inhibit endothelial meshwork formation on extracellular matrix gels by normal and immortalized human umbilical vein cells. This inhibition was associated with an increase in oxidative stress markers, endoplasmic reticulum (ER) stress markers, and autophagy. Induction of ER stress occurred at pharmacologically relevant concentrations of efavirenz and resulted in reduced proliferation and cell viability of endothelial cells, which worsened in the presence of elevated efavirenz concentrations. In combination with the HIV protease inhibitor nelfinavir, both oxidative stress and ER stress became elevated in endothelial cells. These data indicate that pharmacologically relevant concentrations of efavirenz can impair cell viability of endothelial cells and that these effects may be aggravated by either elevated concentrations of efavirenz or by a combined use of efavirenz with other oxidative stress-inducing medications.Cardiovascular Toxicology 02/2015; DOI:10.1007/s12012-015-9314-2 · 2.06 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Efavirenz (EFV) is among the most commonly used antiretroviral drugs globally, causes neurological symptoms that interfere with adherence and reduce tolerability, and may have central nervous system (CNS) effects that contribute in part to HIV associated neurocognitive disorders (HAND) in patients on combination antiretroviral therapy (cART). Thus we evaluated a commonly used EFV containing regimen: EFV/zidovudine (AZT)/lamivudine (3TC) in murine N2a cells transfected with the human "Swedish" mutant form of amyloid precursor protein (SweAPP N2a cells) to assess for promotion of amyloid-beta (Aβ) production. Treatment with EFV or the EFV containing regimen generated significantly increased soluble amyloid beta (Aβ), and promoted increased β-secretase-1 (BACE-1) expression while 3TC, AZT, or, vehicle control did not significantly alter these endpoints. Further, EFV or the EFV containing regimen promoted significantly more mitochondrial stress in SweAPP N2a cells as compared to 3TC, AZT, or vehicle control. We next tested the EFV containing regimen in Aβ - producing Tg2576 mice combined or singly using clinically relevant doses. EFV or the EFV containing regimen promoted significantly more BACE-1 expression and soluble Aβ generation while 3TC, AZT, or vehicle control did not. Finally, microglial Aβ phagocytosis was significantly reduced by EFV or the EFV containing regimen but not by AZT, 3TC, or vehicle control alone. These data suggest the majority of Aβ promoting effects of this cART regimen are dependent upon EFV as it promotes both increased production, and decreased clearance of Aβ peptide.PLoS ONE 04/2014; 9(4):e95500. DOI:10.1371/journal.pone.0095500 · 3.53 Impact Factor