Project description:During the course of multiple sclerosis (MS), inflammatory insults drive neuro-axonal loss and disability progression. Here we leverage translating ribosome affinity purification (TRAP) to extract ribosome-bound mRNA from Chat-positive motor neurons of mice undergoing experimental autoimmune encephalomyelitis (EAE), the animal model of MS. This unique dataset allows to follow the temporal dynamics of neuronal responses to inflammation and enables the extractions of molecular targets for therapeutic intervention.
Project description:Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by progressive paralysis resulting from specific degeneration of upper and lower motor neurons (MNs). Chronic neuroinflammation, mediated by activated microglia, is a hallmark of patients diagnosed with ALS, and correlates with disease pathogenesis. Protecting MNs, particularly from toxic insults caused by neuroinflammation, could lead to effective treatments of ALS patient. Here, we report a screening campaign identifying a series of pyrazolotriazines that cell-autonomously protect MNs against neuroinflammation. We demonstrate that these compounds inhibit Cyclin-dependent kinase 5 (CDK5) and Glycogen synthase kinase 3 (GSK3), and we use phospho-proteomics to show that neuroprotection is linked to alterations in microtubule dynamics.
Project description:Neuroinflammatory processes are a prominent contributor to the pathology of Parkinson’s disease (PD), characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN) and deposits of α-synuclein aggregates. MLKL-mediated cell necroptosis might occur in the onset of PD and lead to neuronal dopaminergic degeneration. However, the link between α-synuclein, neuroinflammatory processes, and neurodegeneration in PD remains unclear. Here, our in vitro study indicated that inhibition of MLKL exerted a protective effect against 6-OHDA- and TNF-α-induced neuronal cell death. Furthermore, we created a mouse model (Tg-Mlkl-/-) with typical progressive Parkinson traits by crossbreeding SNCA A53T transgenic mice with MLKL knockout mice. Tg-Mlkl-/ mice displayed dramatically improved motor symptoms and reduced hyperphosphorylated α-synuclein expression. More data suggested that MLKL deficiency protected dopaminergic neurons, blocked neuronal cell death, and attenuated neuroinflammation by inhibiting the activation of the microglia and astrocytes. Single-cell RNA-seq analysis revealed reduced microglial cells and damped neuron death in the SN of the Tg-Mlkl-/- mice. Subcluster analysis identified a unique cell type-specific transcriptome profiling in the MLKL deficiency mice. Thus, MLKL represents a critical therapeutic target for reducing neuroinflammation and preventing dopaminergic neuron degeneration.
Project description:RNA modifications are essential for the establishment of cellular identity. Although increasing evidence indicates that RNA modifications control the innate immune response, their role in monocyte-to-macrophage differentiation and polarisation is unclear. We profile translatomes of monocytes and macrophages at resting, pro- and anti-inflammatory states.
Project description:Neuroinflammation plays a role in the progression of several neurodegenerative disorders. We used a lipolysaccharide (LPS) model of neuroinflammation to characterize the gene expression changes underlying the inflammatory and behavioral effects of neuroinflammation. A single intracerebroventricular injection of LPS (5 ug) was administered into the lateral ventricle of mice and, 24 hours later, we examined gene expression in the cerebral cortex and hippocampus using microarray technology. Gene Ontology (GO) terms for inflammation and the ribosome were significantly enriched by LPS, whereas GO terms associated with learning and memory had decreased expression. We detected 224 changed transcripts in the cerebral cortex and 170 in the hippocampus. Expression of Egr1 (also known as Zif268) and Arc, two genes associated with learning and memory, was significantly lower in the cortex, but not hippocampus, of LPS-treated animals. Overall, altered expression of these genes may underlie some of the inflammatory and behavioral effects of neuroinflammation. Mice were given intracerebroventricular injections of saline vehicle (n = 4) or lipopolysaccharide (n = 4). Twenty-four hours later, we dissected the hippocampus and cerebral cortex and processed the tissue for microarray analysis. Gene expression changes observed in the microaray data were validated with quantitative real-time PCR.
Project description:Neuroinflammation is a hallmark of ischemic stroke, which is a leading cause of death and longterm disability. Understanding the exact cellular signaling pathways that initiate and propagate neuroinflammation after stroke will be critical for developing immunomodulatory stroke therapies. In particular, the precise mechanisms of inflammatory signaling in the clinically relevant hyperacute period, hours after stroke, have not been elucidated. We used the RiboTag technique to obtain Astrocyte IP and microglia-derived mRNA transcripts in a hyperacute (4 hours) and acute (3 days) period after stroke, as these two cell types are key modulators of acute neuroinflammation. Microglia initiated a rapid response to stroke at 4 hours by adopting an inflammatory profile associated with the recruitment of immune cells. The hyperacute Astrocyte IP profile was marked by stress response genes and transcription factors, such as Fos and Jun, involved in pro-inflammatory pathways such as TNF-α. By 3 days, microglia shift to a proliferative state and Astrocyte IPs strengthen their inflammatory response. The Astrocyte IP pro-inflammatory response at 3 days is partially driven by the upregulation of the transcription factors C/EBPβ, Spi1, and Rel, which comprise 25% of upregulated transcription factor-target interactions. Surprisingly, few sex differences across all groups were observed. Expression and log2 fold data for all sequenced genes are available on a user-friendly website for researchers to examine gene changes and generate hypotheses for stroke targets. Taken together our data comprehensively describe the Astrocyte IP and microglia-specific translatome response in the hyperacute and acute period after stroke and identify pathways critical for initiating neuroinflammation.
Project description:The aim of this study is to profile gene expression dynamics during the in vitro differentiation of embryonic stem cells into ventral motor neurons. Expression levels were profiled using Affymetrix microarrays at six timepoints during in vitro differentiation: ES cells (Day 0), embryoid bodies (Day 2), retinoid induction of neurogenesis (Day 2 +8hours of exposure to retinoic acid), neural precursors (Day 3), progenitor motor neurons (Day 4), postmitotic motor neurons (Day 7). The differentiation of ventral motor neurons is induced by treating embryonic stem cell cultures with retinoic acid and hedgehog agonist. Here, gene expression patterns are profiled at various defined stages during the differentiation process using Affymetrix expression arrays.