Paroxetine suppresses reactive microglia-mediated but not lipopolysaccharide-induced inflammatory responses in primary astrocytes

Abstract

Background: Astrocytes are the most abundant glial cells in a brain that mediate inflammatory responses and provide trophic support for neurons. We have previously disclosed that paroxetine, a common selective serotonin reuptake inhibitor, ameliorates LPS-induced microglia activation. However, it remains elusive of the role of paroxetine in astrocytic responses. Methods: Isolated primary astrocytes were pretreated with paroxetine and stimulated with different stimuli, lipopolysaccharide (LPS) or microglia conditioned medium pre-activated with LPS (M/Lps). Inflammatory and neurotrophic responses, underlying mechanisms and the impact on neuronal survival were assessed. Results: Paroxetine had no impact on LPS-stimulated iNOS, TNF-α and IL-1β expression, but inhibited M/Lps-induced TNF-α and IL-1β expression in primary astrocytes. Paroxetine suppressed M/Lps- but not LPS-induced activation of NF-κB and had no impact on activation of MAPKs and STAT3. Incubation with the resulted astrocyte conditioned media caused no change in viability of SH-SY5Y cells. BDNF and MANF mRNA expressions were upregulated by M/Lps and paroxetine, respectively. However, M/Lps- or LPS-induced extracellular releases of NO, TNF-α and/or BDNF in astrocytes were in minor amount compared to those by microglia. Conclusions: Paroxetine ameliorates the reactive microglia-mediated inflammatory responses in astrocytes partially via inhibition of NF-κB pathway, but has no impact on LPS-stimulated astrocyte activation. While the effect of paroxetine on secondary astrocytic responses are not robust compared to its effect on the innate immune responses of microglia, the results together may implicate a therapeutic potential of paroxetine against neuroinflammation-associated neurological disorders such as Parkinson’s disease. Keywords: paroxetine, astrocytes, microglia, neuroinflammation, Parkinson’s disease

Glucose availability limits microglial nitric oxide production

“…Some authors have reported a robust response of astrocytes to LPS/IFNγ (e.g. Hamby et al, 2010; Hua et al, 2002), whereas others report no response (Possel et al, 2000; Sheng et al, 2011; Zhang et al, 2020), as observed here. The reasons for these differences are not clear but could stem from contaminating microglia in putatively pure astrocyte cultures or to differing culture conditions.…”

Differential and paradoxical roles of new-generation antidepressants in primary astrocytic inflammation

“…As a comparison, in a recent study where primary astrocytes were cultured with serum-containing medium, paroxetine was shown to suppress microglia conditioned medium-stimulated astrocytic in ammation partially via the p65/NFκB pathway, but not by STAT3 and JNK1/2. In addition, paroxetine showed no impact on lipopolysaccharide-induced astrocytic responses [18]. These results indicate that the phenotype (A1, A2, resting, or mixed) and the stimulus matter how antidepressants play a role in astrocytes.…”

“…Inhibitors SP600125 (S1876) and AG490 (HY-12000) were respectively purchased from Beyotime (Shanghai, China) and MedChemExpress (Monmouth Junction, NJ, USA). Immuno uorescence As previously described [18], cells were xed in 4% paraformaldehyde for 30 min and washed with phosphate buffered saline (PBS), followed by permeabilization in 0.2% Triton X-100 for 20 min. Samples were blocked with 5% bovine serum albumin (ST023; Beyotime, Shanghai, China) for 1 h and then incubated with primary antibodies against GFAP (MAB360; Merck Millipore, Billerica, MA, USA), p65 (8242; Cell Signaling, Boston, MA, USA), C3 (EPR9394; Abcam, Cambridge, United Kingdom) or S100A10 (11250-1-AP; Proteintech, Rosemont, IL, USA) at 4 °C overnight.…”

Molecular Mechanism of Sevoflurane Preconditioning Based on Whole-transcriptome Sequencing of Lipopolysaccharide-induced Cardiac Dysfunction in Mice

“…Otud1 (OTU Deubiquitinase 1) is a deubiquitinating enzyme that can regulate the content of IFN regulatory factor 3 in mice after LPS stimulation. 34 Manf (mesencephalic astrocyte–derived neurotrophic factor), an anti-inflammatory factor, 35 reduces LPS-induced IL-1β, TNF-α, and Interferon γ proinflammatory cytokines by regulating the phosphorylation of NF-κB and p38 MAPK pathways. 36 In addition, it has been shown to be a potential target gene for the treatment of acute kidney injury.…”