Selective blockade of the lyso-PS lipase ABHD12 stimulates immune responses in vivo

Abstract

ABHD12 metabolizes bioactive lysophospholipids, including lysophosphatidylserine (lyso-PS). Deleterious mutations in human ABHD12 cause the neurological disease PHARC, and ABHD12(−/−) mice display PHARC-like phenotypes, including hearing loss, along with elevated brain lyso-PS and features of stimulated innate immune cell function. Here, we develop a selective and in vivo -active inhibitor of ABHD12 termed DO264 and show that this compound elevates lyso-PS in mouse brain and primary human macrophages. Unlike ABHD12(−/−) mice, adult mice treated with DO264 exhibited minimal perturbations in auditory function. On the other hand, both DO264-treated and ABHD12(−/−) mice displayed heightened immunological responses to lymphocytic choriomeningitis virus (LCMV) clone 13 infection that manifested as severe lung pathology with elevated proinflammatory chemokines. These results reveal similarities and differences in the phenotypic impact of pharmacological versus genetic blockade of ABHD12 and point to a key role for this enzyme in regulating immunostimulatory lipid pathways in vivo .

Three-dimensional bioprinted glioblastoma microenvironments model cellular dependencies and immune interactions

“…Mononuclear cells were isolated by gradient centrifugation using Lymphoprep (#07851 STEMCELL), washed with PBS, and treated with red blood cell lysis buffer. Cells were plated to adhere monocytes and cultured in 10% heat inactivated FBS in RPMI with HEPES, GlutaMAX, 1 mM Sodium Pyruvate, and Pen/Strep with 50 ng/mL M-CSF for 6 days as described by Ogasawara et al 71 Unpolarized M0 macrophages were collected and integrated into 3D bioprinted models as described above.…”

Elevated Levels of Arachidonic Acid-Derived Lipids Including Prostaglandins and Endocannabinoids Are Present Throughout ABHD12 Knockout Brains: Novel Insights Into the Neurodegenerative Phenotype

“…(Kettenmann et al, 2011). It was previously shown that brain levels of lysoPS TLR2 ligands were upregulated with ABHD12 deletion (Blankman et al, 2013; Ogasawara et al, 2018). Consistent with the neuroinflammation and neurodegeneration hypothesis of PHARC, there was increased microglial activation in ABHD12 KO mouse brains (Blankman et al, 2013).…”

Chemical Biology Gateways to Mapping Location, Association, and Pathway Responsivity

“…Perhaps Daniel Bovet's award of the 1957 Nobel Prize for physiology or medicine is the best example of the use of inhibitors for both academic and industrial pursuits 1 . The Nobel Prize in Physiology or Medicine 1957 was awarded to Daniel Bovet “for his discoveries relating to synthetic compounds that inhibit the action of certain body substances, and especially their action on the vascular system and the skeletal muscles.” Inhibitors continue to be used to study age- or context-specific loss of protein function for comparison to genetic knockout studies or to better model diseases (Ogasawara et al, 2018). Of equal importance, since knockout and chemical inhibition are not necessarily the same in terms of percentage of loss of function and the effect on global protein function, such chemical-biology experiments require careful consideration and data interpretation (Hedstrom, 2017).…”