Biology subjects

Henderson, B. W.

Publications and source records attributed to Henderson, B. W..

4 recordsLinked to original sources

bioRxiv2025

microRNA-206 is a reproducibly sensitive and specific plasma biomarker of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating and fatal neurodegenerative disease with no current therapeutic to modify disease progression. Reliable biomarkers for ALS are essential for improving diagnosis and evaluating therapeutic efficacy. We combined small-RNA sequencing from a discovery cohort of ALS patients and healthy controls with sequencing data from a previously published ALS cohort to identify candidate biomarkers. Machine learning analysis identified hsa-miR-206 as a strong classifier of ALS status in both cohorts. This finding was validated in an independent ALS cohort using droplet digital PCR (ddPCR), confirming the biomarkers sensitivity and specificity in identifying ALS. Importantly, hsa-miR-206 also displayed high accuracy in differentiating ALS from Parkinsons disease. These results further validate hsa-miR-206 as a circulating small-RNA biomarker for ALS with potential utility in diagnosis and therapeutic monitoring. Further studies in larger, diverse cohorts will be needed to validate its clinical applicability.

genomics↗

bioRxiv2025

Mapping the ISR Landscape in Cognitive Disorders via single-cell multi-omics

Persistent activation of the integrated stress response (ISR) is a major driver of cognitive decline in both neurodevelopmental and neurodegenerative disorders. Using a new mouse model (Ppp1r15bR658C mice) that mimics the persistent ISR activation and cognitive decline observed in humans, we generated the first single-cell ISR atlas of the brain. By integrating single-cell RNA-seq and single-cell ATAC-seq with proteomics, we discovered that distinct brain cell types respond differently to persistent ISR activation and elicit cell-type-specific ISR programs. Interestingly, chromatin accessibility analyses revealed that the ISR downstream factor ATF4 is a key ISR effector in GABAergic neurons, while AP-1 (JUNB) is implicated in glutamatergic neurons. More importantly, selective deletion of ATF4 in GABAergic neurons--but not in glutamatergic neurons--impacts ISR-mediated cognitive decline in Ppp1r15bR658C mice, demonstrating that different neuronal subtypes rely on unique ISR downstream effectors to regulate mnemonic processes. Furthermore, we defined a comprehensive molecular signature of persistent ISR activation, which we showed could serve as a biomarker for cognitive dysfunction across neurodevelopmental, neurodegenerative disorders and normal aging. This multi-omic framework provides a key platform for exploring and validating new scientific hypotheses, significantly advancing our understanding of ISR-related brain disorders.

neuroscience↗

bioRxiv2023

Distinct roles of Bdnf I and Bdnf IV transcript variant expression in hippocampal neurons

Brain-derived neurotrophic factor (Bdnf) plays a critical role in brain development, dendritic growth, synaptic plasticity, as well as learning and memory. The rodent Bdnf gene contains nine 5' non-coding exons (I-IXa), which are spliced to a common 3' coding exon (IX). Transcription of individual Bdnf variants, which all encode the same BDNF protein, is initiated at unique promoters upstream of each non-coding exon, enabling precise spatiotemporal and activity-dependent regulation of Bdnf expression. Although prior evidence suggests that Bdnf transcripts containing exon I (Bdnf I) or exon IV (Bdnf IV) are uniquely regulated by neuronal activity, the functional significance of different Bdnf transcript variants remains unclear. To investigate functional roles of activity-dependent Bdnf I and IV transcripts, we used a CRISPR activation (CRISPRa) system in which catalytically-dead Cas9 (dCas9) fused to a transcriptional activator (VPR) is targeted to individual Bdnf promoters with single guide RNAs (sgRNAs), resulting in transcript-specific Bdnf upregulation. Bdnf I upregulation is associated with gene expression changes linked to dendritic growth, while Bdnf IV upregulation is associated with genes that regulate protein catabolism. Upregulation of Bdnf I, but not Bdnf IV, increased mushroom spine density, volume, length, and head diameter, and also produced more complex dendritic arbors in cultured rat hippocampal neurons. In contrast, upregulation of Bdnf IV, but not Bdnf I, in the rat hippocampus attenuated contextual fear expression. Our data suggest that while Bdnf I and IV are both activity-dependent, BDNF produced from these promoters may serve unique cellular, synaptic, and behavioral functions.

neuroscience↗

bioRxiv2018

Distinct and Complementary Functions of Rho kinase isoforms ROCK1 and ROCK2 in Prefrontal Cortex Structural Plasticity

Twenty-nine protein kinase inhibitors have been used to treat human diseases. Out of these, two are Rho-associated protein kinase (ROCK) 1 and 2 inhibitors. ROCKs are attractive drug targets for a range of neurologic disorders; however a critical barrier to ROCK-based therapeutics is ambiguity over whether there are isoform-specific roles for ROCKs in neuronal structural plasticity. Here, we used a genetics approach to address this long-standing question. Both male and female adult ROCK1+/- and ROCK2+/- mice exhibited anxiety-like behaviors compared to littermate controls. Individual pyramidal neurons in the medial prefrontal cortex (mPFC) were targeted for iontophoretic microinjection of fluorescent dye, followed by high-resolution confocal microscopy and neuronal 3D reconstructions for morphometry analysis. Increased apical and basolateral dendritic length and intersections were observed in ROCK1+/- but not ROCK2+/- mice. Although dendritic spine densities were comparable among genotypes, apical spine extent was decreased in ROCK1+/- but increased in ROCK2+/- mice. Spine head and neck diameter were reduced similarly in ROCK1+/- and ROCK2+/- mice; however certain spine morphologic subclasses were more affected than others in a genotype-dependent manner. Biochemical analyses of ROCK substrates revealed that phosphorylation of LIM kinase was reduced in synaptic fractions from ROCK1+/- or ROCK2+/- mice, correlating to overlapping spine morphology phenotypes. Collectively, these observations implicate ROCK1 as a novel regulatory factor of neuronal dendritic structure and detail distinct and complementary roles of ROCKs in mPFC dendritic spine structural plasticity. This study provides a fundamental basis for current and future development of isoform-selective ROCK inhibitors to treat neurologic disorders.\n\nSignificance StatementThe Rho-associated protein kinases (ROCK) 1 and 2 heavily influence neuronal architecture and synaptic plasticity. ROCKs are exciting drug targets and pan-ROCK inhibitors are clinically approved to treat hypertension, heart failure, glaucoma, spinal cord injury, and stroke. However development of isoform-specific ROCK inhibitors is hampered due to ambiguity over ROCK1- or ROCK2-specific functions in the brain. Our study begins to address this critical barrier and demonstrates that ROCK1 can mediate the dendritic arbor of neurons while both ROCK1 and ROCK2 heavily influence dendritic spine morphology. This study highlights distinct and complementary roles for ROCK1 and ROCK1 in prefrontal cortex structural plasticity and provides a fundamental basis for future development of isoform-selective ROCK inhibitors to treat neurologic disorders.

neuroscience↗