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AIDS Research and Human Retroviruses (1)
Purinergic Signalling (1)
Arteaga, Jose (1)
Arteaga, Jose Luis (1)
Climent, Belén (1)
Fernandes, Vítor S. (1)
García-Sacristán, Albino (1)
Hernández, Juan C. (1)
Hernández, Medardo (1)
Kumar, Ajit (1)
Latz, Eicke (1)
Martínez, María Pilar (1)
Martínez-Sáenz, Ana (1)
Orensanz, Luis M. (1)
Paul, Stéphane (1)
Prieto, Dolores (1)
Recio, Paz (1)
Ribeiro, Ana S. F. (1)
Urcuqui-Inchima, Silvio (1)
Year of Publication
Up-Regulation of TLR2 and TLR4 in Dendritic Cells in Response to HIV Type 1 and Coinfection with Opportunistic Pathogens
Hernández, Juan C.
AIDS Research and Human Retroviruses
The ability to trigger an innate immune response against opportunistic pathogens associated with HIV-1 infection is an important aspect of AIDS pathogenesis. Toll-like receptors (TLRs) play a critical role in innate immunity against pathogens, but in HIV-1 patients coinfected with opportunistic infections, the regulation of TLR expression has not been studied. In this context, we have evaluated the expression of TLR2 and TLR4 in monocytes, plasmacytoid dendritic cells, and myeloid dendritic cells of HIV-1 patients with or without opportunistic infections. Forty-nine HIV-1-infected individuals were classified according to viral load, highly active antiretroviral therapy (HAART), and the presence or absence of opportunistic infections, and 21 healthy subjects served as controls. Increased expression of TLR2 and TLR4 was observed in myeloid dendritic cells of HIV-1 patients coinfected with opportunistic infections (without HAART), while TLR4 increased in plasmacytoid dendritic cells, compared to both HIV-1 without opportunistic infections and healthy subjects. Moreover, TLR2 expression was higher in patients with opportunistic infections without HAART and up-regulation of TLR expression in HIV-1 patients coinfected with opportunistic infections was more pronounced in dendritic cells derived from individuals coinfected with Mycobacterium tuberculosis. The results indicate that TLR expression in innate immune cells is up-regulated in patients with a high HIV-1 load and coinfected with opportunistic pathogens. We suggest that modulation of TLRs expression represents a mechanism that promotes HIV-1 replication and AIDS pathogenesis in patients coinfected with opportunistic pathogens.
Mechanisms involved in the adenosine-induced vasorelaxation to the pig prostatic small arteries
Ribeiro, Ana S. F.
Fernandes, Vítor S.
Orensanz, Luis M.
Martínez, María Pilar
Benign prostatic hypertrophy has been related with glandular ischemia processes and adenosine is a potent vasodilator agent. This study investigates the mechanisms underlying the adenosine-induced vasorelaxation in pig prostatic small arteries. Adenosine receptors expression was determined by Western blot and immunohistochemistry, and rings were mounted in myographs for isometric force recording. A2A and A3 receptor expression was observed in the arterial wall and A2A-immunoreactivity was identified in the adventitia–media junction and endothelium. A1 and A2B receptor expression was not obtained. On noradrenaline-precontracted rings, P1 receptor agonists produced concentration-dependent relaxations with the following order of potency: 5′-N-ethylcarboxamidoadenosine (NECA) = CGS21680 > 2-Cl-IB-MECA = 2-Cl-cyclopentyladenosine = adenosine. Adenosine reuptake inhibition potentiated both NECA and adenosine relaxations. Endothelium removal and ZM241385, an A2A antagonist, reduced NECA relaxations that were not modified by A1, A2B, and A3 receptor antagonists. Neuronal voltage-gated Ca2+ channels and nitric oxide (NO) synthase blockade, and adenylyl cyclase activation enhanced these responses, which were reduced by protein kinase A inhibition and by blockade of the intermediate (IKCa)- and small (SKCa)-conductance Ca2+-activated K+ channels. Inhibition of cyclooxygenase (COX), large-conductance Ca2+-activated-, ATP-dependent-, and voltage-gated-K+ channel failed to modify these responses. These results suggest that adenosine induces endothelium-dependent relaxations in the pig prostatic arteries via A2A purinoceptors. The adenosine vasorelaxation, which is prejunctionally modulated, is produced via NO- and COX-independent mechanisms that involve activation of IKCa and SKCa channels and stimulation of adenylyl cyclase. Endothelium-derived NO playing a regulatory role under conditions in which EDHF is non-functional is also suggested. Adenosine-induced vasodilatation could be useful to prevent prostatic ischemia.
Pig prostatic small arteries; Endothelial A2A purinoceptors; A2A expression; NECA; Vasorelaxation; Adenylyl cyclase; IKCa channels; SKCa channels
Results 1-2 (2)
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