Mitochondrial membrane potential and apoptosis of blood mononuclear cells in untreated HIV-1 infected patients.

OBJECTIVES: Infection with HIV leads to progressive CD4 T-cell loss, resulting in AIDS. Apoptosis is the main mechanism for the loss of infected and bystander cells, but the complex interacting factors inducing and inhibiting apoptosis are not fully understood. Mitochondrial dysfunction is a pivotal step of the apoptotic cascade and can result in reduced mitochondrial membrane potential. METHODS: The mitochondrial membrane potential of peripheral blood mononuclear cells (PBMC) was measured by flow cytometry using the dye JC-1 (Molecular Probes Inc). Apoptotic cells were identified using the Annexin V assay (Becton Dickinson GmbH). RESULTS: The mitochondrial membrane potential of PBMC was significantly decreased and apoptotic cell rate was increased in HIV-infected therapy-naïve patients compared with HIV-negative controls. There was a highly significant correlation between the mitochondrial membrane potential and the rate of apoptosis. CD4 cell count was correlated negatively to the apoptotic rate and positively to the mitochondrial membrane potential. CONCLUSIONS: The JC-1 assay is a sensitive tool to detect changes of mitochondrial membrane potential associated with apoptosis in HIV-infected therapy-naïve patients. We could show in vivo that a reduction of mitochondrial membrane potential is correlated to apoptosis of PBMC, CD4 cell count and HIV viral load during HIV infection.

Increased red cell corpuscular volume and hepatic mitochondrial function in NRTI-treated HIV infected patients.

An increase of the mean corpuscular volume of the red blood cells has been repeatedly described in antiretroviral treated patients. Most commonly macrocytosis was associated with the use of certain nucleoside reverse transcriptase inhibitors. The aim of this study was to analyse if macrocytosis might be a marker of mitochondrial toxicity in antiretrovirally treated HIV-infected patients. Using the (13)C-methionine breath test we analysed the hepatic mitochondrial function in vivo in antiretrovirally treated HIV-infected patients with macrocytosis. MCV was significantly negatively correlated to the breath test results. For the first time we could show a significant association between an increase of the mean corpuscular erythrocyte volume by treatment with nucleoside reverse transcriptase inhibitors (NRTI) and the hepatic mitochondrial function in vivo.

The influence of HIV infection and antiretroviral therapy on the mitochondrial membrane potential of peripheral mononuclear cells.

OBJECTIVES: Clinical disorders occurring in HIV-infected patients on antiretroviral therapy (ART) have been linked to mitochondrial dysfunction, for example, lactic acidosis and lipodystrophy. Mitochondrial membrane potential (delta psi m) is the most direct measure of the state of energization of the mitochondria. We analysed delta psi m, of peripheral blood mononuclear cells (PBMCs) in HIV-negative, healthy subjects (n=8), HIV-infected, treatment-naive patients (n=30), and HIV-infected patients on ART (n=58). The influence of ART was analysed in six patients who started their first regimen. METHODS: The delta psi m of PBMC was measured by flow cytometry using the dye JC-1. RESULTS: The delta psi m was significantly lower in HIV-infected patients than in HIV-negative controls. This difference was detected in both treated (P = 0.0001) and untreated patients (P = 0.001). The delta psi m of PBMCs was highly correlated with CD4+ T-cell count in therapy-naive patients (P = 0.002, r = 0.546) and in treated patients (P = 0.028, r = 0.288). The delta psi m increased significantly in therapy-naive patients after starting ART (P = 0.001). Patients with lipoatrophy had significantly lower delta psi m than patients without lipodystrophy or with lipohypertrophy (P = 0.023). CONCLUSIONS: In HIV-infected persons delta psi m is significantly reduced. Patients with lipoatrophy have significantly reduced delta psi m. This is the first study showing that the delta psi m of PBMCs is highly correlated with CD4+ T-cell count in HIV infection.

Macroenzyme creatine kinase (CK) type 2 in HIV-infected patients is significantly associated with TDF and consists of ubiquitous mitochondrial CK.

OBJECTIVE: To evaluate the prevalence and origin of macroenzyme creatine kinase type 2 (Macro CK2) in HIV-1-infected patients on antiretroviral treatment. DESIGN: CK, CK-MB activity and protein weight, electrophoretic behaviour, glomerular filtration rate (GFR), aspartate aminotransferase (AST), alanine aminotransferase (ALT), bone alkaline phosphatase (AP), beta2-microglobulin serum levels and proteinuria were analysed in 468 HIV-infected outpatients. Sera with detectable Macro CK2 were further analysed using immunoblotting. RESULTS: CK-MB isoenzyme activity and mass concentration revealed the presence of Macro CK2 in 32/408 (7.8%) outpatients. Tenofovir DF (TDF) treatment was a prominent common feature in these patients. Prospective examination of sera from 41 patients collected prior to and during TDF exposure showed Macro CK2 in 20/41 (48%) TDF-treated patients and in 0/19 control sera from patients with TDF-free regimens. Macro CK2 was not present prior to TDF exposure. Patients with Macro CK2 showed a significant elevation of serum beta2-microglobulin levels. GFR, AST/ALT ratio, bone AP and proteinuria remained unchanged. Electrophoresis and immunoblotting demonstrated that the Macro CK2 in TDF-treated patients consisted of the ubiquitous (uMtCK) and not the sarcomeric type (sMtCK) of mitochondrial CK (MtCK). CONCLUSIONS: Macro CK2 consisting of uMtCK is associated with the use of TDF-containing regimens. Whether the appearance of uMtCK in these patients reflects mitochondrial damage remains to be clarified.