Dataset Information

PLCG2 regulates endocannabinoid and eicosanoid networks in innate immune cells

ABSTRACT: Human genetic studies have pointed to a prominent role for innate immunity and lipid pathways in human immunological and neurodegenerative disorders. Our understanding of the composition and function of immunomodulatory lipid networks in innate immune cells, however, remains incomplete. Here, we show that phospholipase C gamma 2 (PLCγ2 or PLCG2) – mutations in which are associated with autoinflammatory disorders and Alzheimer’s disease – serves as a principal source of diacylglycerol (DAG) pools that are converted into a cascade of bioactive endocannabinoid (eCB) and eicosanoid lipids by DAG lipase (DAGL) and monoacylglycerol lipase (MGLL) enzymes in innate immune cells. We show that this lipid network is tonically stimulated by disease-relevant human mutations in PLCγ2, as well as Fc receptor activation in primary human and mouse macrophages. Genetic disruption of PLCγ2 in mouse microglia suppressed DAGL/MGLL-mediated eCB-eicosanoid crosstalk and also caused widespread transcriptional and proteomic changes, including the reorganization of immune-relevant lipid pathways reflected in reductions in DAGLB and elevations in PLA2G4A. Despite these changes, Plcg2-/- mice showed generally normal pro-inflammatory cytokine responses to lipopolysaccharide treatment, instead displaying a more restricted deficit in microglial activation that included impairments in prostaglandin production and CD68 expression. Our findings enhance the understanding of PLCγ2 function in innate immune cells, delineating a role in crosstalk with endocannabinoid/eicosanoid pathways and modulation of subsets of cellular responses to inflammatory stimuli.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Cell Culture, Microglial Cell, Macrophage

SUBMITTER: Hui Jing

LAB HEAD: Benjamin F. Cravatt

PROVIDER: PXD027350 | Pride | 2021-10-05

REPOSITORIES: Pride

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	201123_PLG2_microglia_WP_01.raw	Raw
	201123_PLG2_microglia_WP_02.raw	Raw
	201123_PLG2_microglia_WP_03.raw	Raw
	201123_PLG2_microglia_WP_04.raw	Raw
	201123_PLG2_microglia_WP_05.raw	Raw

Items per page:

1 - 5 of 42

Similar Datasets

Project description:Dialkyldiazirines have emerged as a photoaffinity probe of choice for interactome mapping in live cell experiments. Upon irradiation, ‘linear’ dialkyldiazirines produce dialkylcarbenes, which are susceptible to both intramolecular reactions and unimolecular elimination processes, as well as diazoalkanes, which also participate in intermolecular labeling. Cyclobutylidene has a nonclassical bonding structure and is stable enough to be captured in bimolecular reactions. Cyclobutanediazirines have more recently been studied as photoaffinity probes based on cyclobutylidene, but the mechanism, especially with respect to the role of putative diazo intermediates, was not fully understood. Here, we show that photolysis (365 nm) of cyclobutanediazirines can produce cyclobutylidene intermediates as evidenced by formation of their expected bimolecular and unimolecular products, including methylenecyclopropane derivatives. Unlike linear diazirines, cyclobutanediazirine photolysis in the presence of tetramethylethylene produces a [2+1] cycloaddition adduct. By contrast, linear diazirines produce diazo compounds upon low temperature photolysis in THF, whereas diazo compounds are not detected in similar photolyses of cyclobutanediazirines. Diazocyclobutane, prepared by independent synthesis, is labile, reactive toward water, and capable of protein alkylation. The rate of diazocyclobutane decomposition is not affected by 365 nm light, suggesting that the photochemical conversion of diazocyclobutane to cyclobutylidene is not an important pathway. Finally, chemical proteomic studies revealed that a likely consequence of this primary conversion to a highly reactive carbene is a marked decrease in labeling by cyclobutanediazirine-based probes relative to linear diazirine counterparts both at the individual protein and proteome-wide levels. Collectively, these observations are consistent with a mechanistic picture for cyclobutanediazirine photolysis that involves carbene chemistry with minimal formation of diazo intermediates, and contrasts with the photolyses of linear diazirines where alkylation by diazo intermediates plays a more significant role.

Dataset Information

PLCG2 regulates endocannabinoid and eicosanoid networks in innate immune cells

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets