Hinz, F. I. | Search bioRxiv

bioRxiv2024

SARM1 orthosteric base exchange inhibitors cause subinhibitory SARM1 activation

SARM1, an octameric NADase, is a key regulator of axon degeneration and an emerging target in small molecule drug discovery to treat a wide range of neurodegenerative diseases. Recently, a structurally diverse series of adduct-forming, orthosteric SARM1 inhibitors have been discovered. Here, we show that subinhibitory concentrations of these orthosteric inhibitors, under mildly SARM1 activating conditions, cause sustained SARM1 activation. This synergistic adverse effect leads to increased nicotinamide adenine dinucleotide (NAD) consumption, neurodegeneration and release of the biomarker neurofilament-light (NfL) in cultured cortical neurons. In two distinct animal models, we found that low-dose treatment with these orthosteric SARM1 inhibitors results in increased plasma NfL and adverse events when combined with cellular stress or injury conditions. This may present a critical liability for orthosteric SARM1 inhibitors in certain patient populations.

neuroscience↗

bioRxiv2018

A single cell transcriptomic analysis of human neocortical development

Defining the number, proportion, or lineage of distinct cell types in the developing human brain is an important goal of modern brain research. We defined single cell transcriptomic profiles for 40,000 cells at mid-gestation to identify cell types in the developing human neocortex. We define expression profiles corresponding to all known major cell types at this developmental period and identify multiple transcription factors and co-factors expressed in specific cell types, providing an unprecedented resource for understanding human neocortical development including the first single-cell characterization of human subplate neurons. We characterize major developmental trajectories during early neurogenesis, showing that cell type differentiation occurs on a continuum that involves transitions that tie cell cycle progression with early cell fate decisions. We use these data to deconvolute regulatory networks and map neuropsychiatric disease genes to specific cell types, implicating dysregulation of specific cell types, as the mechanistic underpinnings of several neurodevelopmental disorders. Together these results provide an extensive catalog of cell types in human neocortex and extend our understanding of early cortical development, human brain evolution and the cellular basis of neuropsychiatric disease.\n\nOne Sentence SummaryComprehensive single cell transcriptomes in developing human cortex inform models of cell diversity, differentiation and disease risk.

neuroscience↗