midostaurin and HIV-Infections

Midostaurin is a multi-kinase inhibitor with antineoplastic activity. We assessed the capacity of midostaurin to affect early and late steps of HIV-1 infection and to reactivate HIV-1 latently infected cells, alone or in combination with histone deacetylase inhibitors (HDACi) known to act as latency-reversing agents (LRA). Acute HIV-1 infection was assessed by flow cytometry in three cell types treated with midostaurin in the presence or absence of SAMHD1. Non-infected cells were treated with midostaurin and harvested for Western blot analysis. Macrophage infections were also measured by quantitative RT-PCR. HIV-1 latency reactivation was assessed in several latency models. Midostaurin induced G2/M arrest and inhibited CDK2, preventing the phosphorylation of SAMHD1 associated to inhibition of its dNTPase activity. In the presence of SAMHD1, midostaurin blocked HIV-1 DNA formation and viral replication. However, following Vpx-mediated SAMHD1 degradation, midostaurin increased viral transcripts and virus replication. In three out of four HIV-1 latency models, including primary CD4

Topics: CD4-Positive T-Lymphocytes; Cell Cycle Checkpoints; Cells, Cultured; Histone Deacetylase Inhibitors; HIV Infections; HIV-1; Humans; Macrophages; Phosphorylation; Protein Kinase Inhibitors; SAM Domain and HD Domain-Containing Protein 1; Staurosporine; Virus Activation; Virus Latency; Virus Replication

Inhibition of mixed lineage kinase 3 (MLK3) is a potential strategy for treatment of Parkinson's disease and HIV-1 associated neurocognitive disorders (HAND), requiring an inhibitor that can achieve significant brain concentration levels. We report here URMC-099 (1) an orally bioavailable (F = 41%), potent (IC50 = 14 nM) MLK3 inhibitor with excellent brain exposure in mouse PK models and minimal interference with key human CYP450 enzymes or hERG channels. The compound inhibits LPS-induced TNFα release in microglial cells, HIV-1 Tat-induced release of cytokines in human monocytes and up-regulation of phospho-JNK in Tat-injected brains of mice. Compound 1 likely functions in HAND preclinical models by inhibiting multiple kinase pathways, including MLK3 and LRRK2 (IC50 = 11 nM). We compare the kinase specificity and BBB penetration of 1 with CEP-1347 (2). Compound 1 is well tolerated, with excellent in vivo activity in HAND models, and is under investigation for further development.

Topics: Administration, Oral; Animals; Area Under Curve; Biological Availability; Blood-Brain Barrier; Brain; Carbazoles; Cells, Cultured; Cognition Disorders; Drug Discovery; HIV Infections; Humans; JNK Mitogen-Activated Protein Kinases; Male; MAP Kinase Kinase Kinases; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase Kinase Kinase 11; Models, Chemical; Molecular Structure; Monocytes; Phosphorylation; Protein Kinase Inhibitors; Pyridines; Pyrroles; tat Gene Products, Human Immunodeficiency Virus; Tumor Necrosis Factor-alpha