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- Ardalan, Maryam, 1979, et al.
(författare)
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Reelin cells and sex-dependent synaptopathology in autism following postnatal immune activation
- 2022
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Ingår i: British Journal of Pharmacology. - : Wiley. - 0007-1188 .- 1476-5381. ; 179:17, s. 4400-4422
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: Autism spectrum disorders (ASD) are heterogeneous neurodevelopmental disorders with considerably increased risk in male infants born preterm and with neonatal infection. Here, we investigated the role of postnatal immune activation on hippocampal synaptopathology by targeting Reelin+ cells in mice with ASD-like behaviours. Experimental Approach: C57/Bl6 mouse pups of both sexes received lipopolysaccharide (LPS, 1 mg·kg−1) on postnatal day (P) 5. At P45, animal behaviour was examined by marble burying and sociability test, followed by ex vivo brain MRI diffusion kurtosis imaging (DKI). Hippocampal synaptogenesis, number and morphology of Reelin+ cells, and mRNA expression of trans-synaptic genes, including neurexin-3, neuroligin-1, and cell-adhesion molecule nectin-1, were analysed at P12 and P45. Key Results: Social withdrawal and increased stereotypic activities in males were related to increased mean diffusivity on MRI-DKI and overgrowth in hippocampus together with retention of long-thin immature synapses on apical dendrites, decreased volume and number of Reelin+ cells as well as reduced expression of trans-synaptic and cell-adhesion molecules. Conclusion and Implications: The study provides new insights into sex-dependent mechanisms that may underlie ASD-like behaviour in males following postnatal immune activation. We identify GABAergic interneurons as core components of dysmaturation of excitatory synapses in the hippocampus following postnatal infection and provide cellular and molecular substrates for the MRI findings with translational value.
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| 2. |
- Sävman, Karin, 1960, et al.
(författare)
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Galectin-3 Modulates Microglia Inflammation in vitro but Not Neonatal Brain Injury in vivo under Inflammatory Conditions
- 2021
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Ingår i: Developmental Neuroscience. - : S. Karger AG. - 0378-5866 .- 1421-9859. ; 43:5, s. 296-311
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Tidskriftsartikel (refereegranskat)abstract
- Microglia may contribute to injury but may also have neuroprotective properties. Galectin-3 has immunomodulatory properties that may affect the microglia phenotype and subsequent development of injury. Galectin-3 contributes to experimental hypoxic-ischemic (HI) injury in the neonatal brain, but it is unclear if galectin-3 has similar effects on infectious and sterile inflammation. Thus, we investigated the effect of galectin-3 on microglia in vitro under normal as well as infectious and sterile inflammatory conditions, and the effect of galectin-3 on neonatal brain injury following an infectious challenge in vivo. Conditions mimicking infectious or sterile inflammation were evaluated in primary microglia cell cultures from newborn mice, using LPS (10 ng/mL) and TNF-alpha (100 ng/mL). The response to galectin-3 was tested alone or together with LPS or TNF-alpha. Supernatants were collected 24 h after treatment and analyzed for 23 inflammatory mediators including pro- and anti-inflammatory cytokines and chemokines using multiplex protein analysis, as well as ELISA for MCP-1 and insulin-like growth factor (IGF)-1. Phosphorylation of proteins (AKT, ERK1/2, I kappa B-alpha, JNK, and p38) was determined in microglia cells. Neonatal brain injury was induced by a combination of LPS and HI (LPS + HI) in postnatal day 9 transgenic mice lacking functional galectin-3 and wild-type controls. LPS and TNF-alpha induced pro-inflammatory (9/11 vs. 9/10) and anti-inflammatory (6/6 vs. 2/6) cytokines, as well as chemokines (6/6 vs. 4/6) in a similar manner, except generally lower amplitude of the TNF-alpha-induced response. Galectin-3 alone had no effect on any of the proteins analyzed. Galectin-3 reduced the LPS- and TNF-alpha-induced microglia response for cytokines, chemokines, and phosphorylation of I kappa B-alpha. LPS decreased baseline IGF-1 levels, and the levels were restored by galectin-3. Brain injury or microglia response after LPS + HI was not affected by galectin-3 deficiency. Galectin-3 has no independent effect on microglia but modulates inflammatory activation in vitro. The effect was similar under infectious and sterile inflammatory conditions, suggesting that galectin-3 regulates inflammation not just by binding to LPS or toll-like receptor-4. Galectin-3 restores IGF-1 levels reduced by LPS-induced inflammation, suggesting a potential protective effect on infectious injury. However, galectin-3 deficiency did not affect microglia activation and was not beneficial in an injury model encompassing an infectious challenge.
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