Anti-HIV drugs decrease the expression of matrix metalloproteinases in astrocytes and microglia

Abstract

The introduction of potent antiretroviral drugs for the treatment of patients with human immunodeficiency virus (HIV) infection has dramatically reduced the prevalence of HIV-associated neurological disorders. Such diseases can be mediated by proteolytic enzymes, i.e. matrix metalloproteinases (MMPs) and, in particular gelatinases, released from glial cells. The aim of this study was to investigate whether the antiretroviral drugs commonly used for the treatment of HIV-infected patients modulate the activity of MMPs in astrocyte and microglial cultures. Primary cultures of rat astrocyte and microglia were treated with different doses of zidovudine (AZT) or indinavir (IDV) for 20 h and simultaneously activated by exposure to lipopolysaccharide (LPS). Culture supernatants collected from astrocytes and microglia after 24 h incubation were subjected to gelatin zymography and western blot analysis for the assessment of MMP-2 (gelatinase A) and MMP-9 (gelatinase B) protein levels. Total RNA was extracted from glial cells and used for reverse transcriptase-polymerase chain reaction for the assessment of mRNA expression. Our results indicate that both astrocyte and microglial cells constitutively express MMP-2 mRNA and protein. LPS treatment increased MMP-2 mRNA and protein expression in astrocytes, but not in microglial cells. The treatment with both AZT and IDV dose-dependently inhibited the expression of MMP-2 in astrocytes, whereas it had no effect on microglial cells. The expression of MMP-9 in both astrocytes and microglia was induced by LPS treatment and was dose-dependently inhibited by AZT and IDV treatment in LPS-stimulated astrocytes and microglia. These results raise the possibility that AZT and IDV interfere directly with MMP production in glial cells and independently from their antiviral activity, thus suggesting the possible therapeutical use in neurological diseases associated with MMPs involvement.

Differential vesicular distribution and trafficking of MMP‐2, MMP‐9, and their inhibitors in astrocytes

“…The apparent discrepancy between these results and our data showing clear MMP-9 expression and LPS-driven upregulation in astrocytes may result from fundamental differences between primary cells and stem cells, which undergo in vivo and in vitro differentiation, respectively, and may be related to differential expression by primary and stem cells of CD14 or LPS-binding protein (LBP), both important for LPS-induced effects in cells (Guillemin et al, 1997;Kitchens, 2000). Using Western blotting, we also show TIMP-1, but not TIMP-2, induction in LPStreated astrocytes, in agreement with previous results in glial cultures (Liu et al, 2007;Liuzzi et al, 2004;Wilczynska et al, 2006). Also, a number of in vivo results, including from our laboratory, indicate that TIMP-1 is induced at high levels in reactive astrocytes (Jaworski, 2000;Rivera et al, 1997Rivera et al, , 2002Wilczynska et al, 2006).…”

A genetic polymorphism of matrix metalloproteinase 9 (MMP-9) affects the changes in circulating MMP-9 levels induced by highly active antiretroviral therapy in HIV patients

“…For example, antiretroviral therapy reduced the capacity of peripheral-blood mononuclear cells to secrete MMP-9 in HIV-infected patients, 32 and zidovudine and indinavir attenuated the increase in MMP-9 expression induced by exposure of both astrocytes and microglia to lipopolysaccharide. 33 It is possible that major methodological differences between these studies and the present study may explain the apparently conflicting findings. The increased pro-MMP-9/TIMP-1 ratios after HAART suggest that HAART increases the cardiovascular risk of AIDS patients through mechanisms involving MMP-9, as suggested by a number of studies showing that net MMP-9 activity levels are associated with cardiovascular diseases and increased cardiovascular risk.…”

Structure-Dependent Inhibition of Gelatinases by Dietary Antioxidants in Rat Astrocytes and Sera of Multiple Sclerosis Patients

“…Gelatinases in cell culture supernatants or in MS sera were detected by SDS-PAGE zymography according to the method of Heussen and Dowdle [38], as modified by Liuzzi et al [39].…”