Neuron-derived CCL2 contributes to microglia activation and neurological decline in hepatic encephalopathy

BACKGROUND: CCL2 was up-regulated in neurons and involved in microglia activation and neurological decline in mice suffering from hepatic encephalopathy (HE). However, no data exist concerning the effect of neuron-derived CCL2 on microglia activation in vitro. METHODS: The rats were pretreated with CCL2 receptor inhibitors (INCB or C021, 1 mg/kg/day i.p.) for 3 days prior to thioacetamide (TAA) administration (300 mg/kg/day i.p.) for inducing HE model. At 8 h following the last injection (and every 4 h after), the grade of encephalopathy was assessed. Blood and whole brains were collected at coma for measuring CCL2 and Iba1 expression. In vitro, primary neurons were stimulated with TNF-α, and then the medium were collected for addition to microglia cultures with or without INCB or C021 pretreatment. The effect of the medium on microglia proliferation and activation was evaluated after 24 h. RESULTS: CCL2 expression and microglia activation were elevated in the cerebral cortex of rats received TAA alone. CCL2 receptors inhibition improved neurological score and reduced cortical microglia activation. In vitro, TNF-α treatment induced CCL2 release by neurons. Medium from TNF-α stimulated neurons caused microglia proliferation and M1 markers expression, including iNOS, COX2, IL-6 and IL-1ß, which could be suppressed by INCB or C021 pretreatment. The medium could also facilitate p65 nuclear translocation and IκBα phosphorylation, and NF-κB inhibition reduced the increased IL-6 and IL-1ß expression induced by the medium. CONCLUSION: Neuron-derived CCL2 contributed to microglia activation and neurological decline in HE. Blocking CCL2 or inhibiting microglia excessive activation may be potential strategies for HE.

Newer targeted therapies in psoriasis.

Psoriasis is a common, chronic, inflammatory skin disease that can have a significant impact on the quality of life of those who are afflicted due to chronicity of the disease and frequent remissions and relapses. Many available systemic therapies, however, are unsuitable for chronic administration due to the risk of cumulative toxicity. Recent advances in the understanding of the pathophysiology of psoriasis have led to the development of new, genetically engineered, targeted therapies for this disease. These include approaches targeting antigen presentation and co-stimulation, T-cell activation and leukocyte adhesion, action on pro-inflammatory mediators, and modulating the cytokine balance. Although only preliminary data are available so far and there is limited data supporting their use, these trials contribute to a further understanding of the disease and will eventually lead to new therapeutic options for psoriasis.

Newer targeted therapies in psoriasis.

Psoriasis is a common, chronic, inflammatory skin disease that can have a significant impact on the quality of life of those who are afflicted due to chronicity of the disease and frequent remissions and relapses. Many available systemic therapies, however, are unsuitable for chronic administration due to the risk of cumulative toxicity. Recent advances in the understanding of the pathophysiology of psoriasis have led to the development of new, genetically engineered, targeted therapies for this disease. These include approaches targeting antigen presentation and co-stimulation, T-cell activation and leukocyte adhesion, action on pro-inflammatory mediators, and modulating the cytokine balance. Although only preliminary data are available so far and there is limited data supporting their use, these trials contribute to a further understanding of the disease and will eventually lead to new therapeutic options for psoriasis.

Chemokines and chemokine receptors in HIV infection: role in pathogenesis and therapeutics.

Chemokines are known to function as regulatory molecules in leukocyte maturation, traffic, homing of lymphocytes and in the development of lymphoid tissues. Besides these functions in the immune system, certain chemokines and their receptors are involved in HIV pathogenesis. In order to infect a target cell, the HIV envelope glycoprotein gp120 has to interact with the cellular receptor CD-4 and co-receptor, CC or CXC chemokine receptors. Genetic findings have yielded major insights into the in vivo roles of individual co-receptors and their ligands in providing resistance to HIV infection. Mutations in chemokine receptor genes are associated with protection against HIV infections and also involved in delayed progression to AIDS in infected individuals. Blocking of chemokine receptors interrupts HIV infection in vitro and this offers new options for therapeutic strategies. Approaches have been made to study the CCR-5 inhibitors as antiviral therapies and possibly as components of a topical microbicide to prevent HIV-1 sexual transmission. Immune strategies aimed at generating anti-CCR-5 antibodies at the level of the genital mucosa might be feasible and represent a strategy to induce mucosal HIV- protective immunity. It also remains to be seen how these types of agents will act in synergy with existing HIV-1 targeted anti viral or those currently in developments. Beyond providing new perspectives in fundamental aspects of the HIV-1 transmission and pathogenesis, chemokines and their receptors suggest new areas for developing novel therapeutic and preventive strategies against HIV infections. Studies in this review were identified through a search for relevant literature in the pubmed database of the national library of medicine. In this review, some developments in chemokine research with particular focus on their roles in HIV pathogenesis, resistance and therapeutic applications have been discussed.

CC-chemokine receptors: a potential therapeutic target for Trypanosoma cruzi-elicited myocarditis

The comprehension of the pathogenesis of Trypanosoma cruzi-elicited myocarditis is crucial to delineate new therapeutic strategies aiming to ameliorate the inflammation that leads to heart dysfunction, without hampering parasite control. The augmented expression of CCL5/RANTES and CCL3/MIP-1alpha, and their receptor CCR5, in the heart of T. cruzi-infected mice suggests a role for CC-chemokines and their receptors in the pathogenesis of T. cruzi-elicited myocarditis. Herein, we discuss our recent results using a CC-chemokine receptor inhibitor (Met-RANTES), showing the participation of CC-chemokines in T. cruzi infection and unraveling CC-chemokine receptors as an attractive therapeutic target for further evaluation in Chagas disease.