Biology subjects

Hackos, D. H.

Publications and source records attributed to Hackos, D. H..

3 recordsLinked to original sources

bioRxiv2023

Human motor neurons are rare and can be transcriptomically divided into known subtypes

We performed single-nucleus RNA-sequencing on adult human spinal cord using a neuronal nuclei enrichment strategy. We obtained transcriptomic profiles of >14,000 spinal neurons, including a small population of motor neurons that shares similarities with mouse motor neurons and can be subdivided into alpha and gamma subtypes. We sought to compare our results to those from a recent study by Yadav and colleagues, which provides a single-nucleus transcriptomic atlas of the human spinal cord. While most neuronal nuclei from both studies share similar features, our results from motor neurons differ substantially. We reanalyzed their RNA-sequencing data and provide evidence that the authors incorrectly identified cholinergic cellular debris as motor neuron nuclei in their dataset, raising doubts about their conclusions regarding motor neurons. Our findings underscore the challenges associated with transcriptionally profiling motor neurons from the spinal cord because of their rarity. We propose specific enrichment strategies and recommend important quality control measures for future transcriptional profiling studies involving human spinal cord tissue and rare cell types.

neuroscience↗

bioRxiv2022

CryoEM reveals unprecedented binding site for NaV1.7 inhibitors enabling rational design of potent hybrid inhibitors

The voltage-gated sodium (NaV) channel NaV1.7 has been identified as a potential novel pain target due to its striking human genetics. However, clinically available drugs (e.g. lidocaine, carbamazepine, etc.) are not selective among the nine NaV channel subtypes, NaV1.1-NaV1.9, and the two currently known classes of NaV1.7 subtype-selective inhibitors (aryl- and acylsulfonamides) have undesirable characteristics that may limit their development. Moreover, understanding of the structure-activity relationships of the acylsulfonamide class of NaV1.7 inhibitors, exemplified by the clinical development candidate GDC-0310, has been based solely on a single co-crystal structure of an arylsulfonamide inhibitor series. To advance inhibitor design targeting the NaV1.7 channel, we established an iterative system to routinely obtain high-resolution ligand-bound NaV1.7 structures using cryogenic electron microscopy (cryo-EM). We report that GDC-0310 engages the NaV1.7 voltage-sensing domain 4 (VSD4) through an unexpected binding mode orthogonal to the arylsulfonamide class binding pose, which identifies a previously unknown ligand binding site in NaV channels. This finding enabled the design of a novel hybrid inhibitor series that bridges the aryl and acylsulfonamide binding pockets and allows for the generation of molecules with substantially differentiated structures and properties. Overall, this study highlights the power of cryo-EM methods to pursue challenging drug targets using iterative and high-resolution structure-guided inhibitor design. It also underscores an important role of the membrane bilayer in the discovery of selective NaV channel modulators.

bioengineering↗

bioRxiv2022

High-resolution cross-species transcriptomic atlas of dorsal root ganglia reveals species-specific programs for sensory function

Sensory neurons of the dorsal root ganglion (DRG) play a crucial role in maintaining tissue homeostasis by sensing and initiating responses to stimuli. While most preclinical studies of DRGs are conducted in rodents, much less is known about the mechanisms of sensory perception in primates. We generated a transcriptome atlas of mouse, guinea pig, cynomolgus monkey, and human DRGs using a framework that implements a common laboratory workflow and multiple data-integration approaches to generate high-resolution cross-species mappings of sensory neuron subtypes. Using our atlas, we identified conserved core modules highlighting subtype-specific biological processes related to inflammatory response. We also identified divergent expression of key genes involved in DRG function, suggesting species-specific adaptations. Among these, we validated that Tafa4, a member of the druggable genome, was expressed in distinct populations of DRG neurons across species, highlighting species-specific programs that are critical for therapeutic development.

neuroscience↗