RESUMO
Neuroinflammation characterizes multiple neurologic diseases, including primary inflammatory conditions such as multiple sclerosis and classical neurodegenerative diseases. Aberrant activation of the innate immune system contributes to disease progression, but drugs modulating innate immunity, particularly within the central nervous system (CNS), are lacking. The CNS-penetrant natural product bryostatin-1 attenuates neuroinflammation by targeting innate myeloid cells. Supplies of natural bryostatin-1 are limited, but a recent scalable good manufacturing practice (GMP) synthesis has enabled access to it and its analogs (bryologs), the latter providing a path to more efficacious, better tolerated, and more accessible agents. Here, we show that multiple synthetically accessible bryologs replicate the anti-inflammatory effects of bryostatin-1 on innate immune cells in vitro, and a lead bryolog attenuates neuroinflammation in vivo, actions mechanistically dependent on protein kinase C (PKC) binding. Our findings identify bryologs as promising drug candidates for targeting innate immunity in neuroinflammation and create a platform for evaluation of synthetic PKC modulators in neuroinflammatory diseases.
Assuntos
Briostatinas/farmacologia , Desenho de Fármacos , Imunidade Inata/efeitos dos fármacos , Inflamação/tratamento farmacológico , Proteína Quinase C-delta/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Animais , Briostatinas/síntese química , Briostatinas/química , Feminino , Imunidade Inata/imunologia , Inflamação/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Conformação Molecular , Gravidez , Proteína Quinase C-delta/metabolismo , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , EstereoisomerismoRESUMO
Using a function-oriented synthesis strategy, we designed, synthesized, and evaluated the simplest bryostatin 1 analogues reported to date, in which bryostatin's A- and B-rings are replaced by a glutarate linker. These analogues, one without and one with a C26-methyl group, exhibit remarkably different protein kinase C (PKC) isoform affinities. The former exhibited bryostatin-like binding to several PKC isoforms with Ki's < 5 nM, while the latter exhibited PKC affinities that were up to â¼180-fold less potent. The analogue with bryostatin-like PKC affinities also exhibited bryostatin-like PKC translocation kinetics in vitro, indicating rapid cell permeation and engagement of its PKC target. This study exemplifies the power of function-oriented synthesis in reducing structural complexity by activity-informed design, thus enhancing synthetic accessibility, while still maintaining function (biological activity), collectively providing new leads for addressing the growing list of therapeutic indications exhibited by PKC modulators.
Assuntos
Macrolídeos , Proteína Quinase C , Briostatinas/farmacologia , LactonasRESUMO
The marine natural product bryostatin 1 has demonstrated procognitive and antidepressant effects in animals and has been entered into human clinical trials for treating Alzheimer's disease (AD). The ability of bryostatin 1 to enhance learning and memory has largely been attributed to its effects on the structure and function of hippocampal neurons. However, relatively little is known about how bryostatin 1 influences the morphology of cortical neurons, key cells that also support learning and memory processes and are negatively impacted in AD. Here, we use a combination of carefully designed chemical probes and pharmacological inhibitors to establish that bryostatin 1 increases cortical synaptogenesis while decreasing dendritic spine density in a protein kinase C (PKC)-dependent manner. The effects of bryostatin 1 on cortical neurons are distinct from those induced by neural plasticity-promoting psychoplastogens such as ketamine. Compounds capable of increasing synaptic density with concomitant loss of immature dendritic spines may represent a unique pharmacological strategy for enhancing memory by improving signal-to-noise ratio in the central nervous system.
Assuntos
Espinhas Dendríticas , Proteína Quinase C , Animais , Briostatinas/farmacologia , Humanos , NeurogêneseRESUMO
HIV latency in resting CD4+ T cell represents a key barrier preventing cure of the infection with antiretroviral drugs alone. Latency reversing agents (LRAs) can activate HIV expression in latently infected cells, potentially leading to their elimination through virus-mediated cytopathic effects, host immune responses, and/or therapeutic strategies targeting cells actively expressing virus. We have recently described several structurally simplified analogs of the PKC modulator LRA bryostatin (termed bryologs) designed to improve synthetic accessibility, tolerability in vivo, and efficacy in inducing HIV latency reversal. Here we report the comparative performance of lead bryologs, including their effects in reducing cell surface expression of HIV entry receptors, inducing proinflammatory cytokines, inhibiting short-term HIV replication, and synergizing with histone deacetylase inhibitors to reverse HIV latency. These data provide unique insights into structure-function relationships between A- and B-ring bryolog modifications and activities in primary cells, and suggest that bryologs represent promising leads for preclinical advancement.
Assuntos
Briostatinas/química , Briostatinas/farmacologia , Desenho de Fármacos , HIV-1/efeitos dos fármacos , Latência Viral/efeitos dos fármacos , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/virologia , Células Cultivadas , Citocinas/efeitos dos fármacos , Citocinas/metabolismo , Infecções por HIV/virologia , HIV-1/fisiologia , Inibidores de Histona Desacetilases , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Ativação Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacosRESUMO
Bryostatin 1 is an exceedingly scarce marine-derived natural product that is in clinical development directed at HIV/AIDS eradication, cancer immunotherapy, and the treatment of Alzheimer's disease. Despite this unique portfolio of indications, its availability has been limited and variable, thus impeding research and clinical studies. Here, we report a total synthesis of bryostatin 1 that proceeds in 29 total steps (19 in the longest linear sequence, >80% average yield per step), collectively produces grams of material, and can be scaled to meet clinical needs (~20 grams per year). This practical solution to the bryostatin supply problem also opens broad, facile, and efficient access to derivatives and potentially superior analogs.