RESUMO
Major depressive disorder is associated with abnormalities in the brain and the immune system. Chronic stress in animals showed that epigenetic and inflammatory mechanisms play important roles in mediating resilience and susceptibility to depression. Here, through a high-throughput screening, we identify two phytochemicals, dihydrocaffeic acid (DHCA) and malvidin-3'-O-glucoside (Mal-gluc) that are effective in promoting resilience against stress by modulating brain synaptic plasticity and peripheral inflammation. DHCA/Mal-gluc also significantly reduces depression-like phenotypes in a mouse model of increased systemic inflammation induced by transplantation of hematopoietic progenitor cells from stress-susceptible mice. DHCA reduces pro-inflammatory interleukin 6 (IL-6) generations by inhibiting DNA methylation at the CpG-rich IL-6 sequences introns 1 and 3, while Mal-gluc modulates synaptic plasticity by increasing histone acetylation of the regulatory sequences of the Rac1 gene. Peripheral inflammation and synaptic maladaptation are in line with newly hypothesized clinical intervention targets for depression that are not addressed by currently available antidepressants.
Assuntos
Antocianinas/farmacologia , Ácidos Cafeicos/farmacologia , Epigênese Genética , Glucosídeos/farmacologia , Inflamação/genética , Plasticidade Neuronal/genética , Estresse Psicológico/genética , Animais , Antocianinas/administração & dosagem , Ácidos Cafeicos/administração & dosagem , Ilhas de CpG/efeitos dos fármacos , Depressão/tratamento farmacológico , Avaliação Pré-Clínica de Medicamentos/métodos , Glucosídeos/administração & dosagem , Interleucina-6/antagonistas & inibidores , Interleucina-6/genética , Antígenos Comuns de Leucócito/genética , Masculino , Camundongos Endogâmicos C57BL , Plasticidade Neuronal/efeitos dos fármacos , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Polifenóis/farmacologia , Comportamento Social , Estresse Psicológico/tratamento farmacológico , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismoRESUMO
Postsynaptic remodeling of glutamatergic synapses on ventral striatum (vSTR) medium spiny neurons (MSNs) is critical for shaping stress responses. However, it is unclear which presynaptic inputs are involved. Susceptible mice exhibited increased synaptic strength at intralaminar thalamus (ILT), but not prefrontal cortex (PFC), inputs to vSTR MSNs following chronic social stress. Modulation of ILT-vSTR versus PFC-vSTR neuronal activity differentially regulated dendritic spine plasticity and social avoidance.