Biology subjects

Strickland, B. A.

Publications and source records attributed to Strickland, B. A..

3 recordsLinked to original sources

bioRxiv2026

A preclinical platform for focused ultrasound delivery from microplate to awake brain

Background. Focused ultrasound (FUS) has broad therapeutic potential, but its mechanisms of action are poorly understood. Preclinical FUS research enables rigorous interrogation of understudied parameters, but fragmented, single-purpose benchtop devices prevent standardized acoustic exposure across models. Objective. To describe a unified preclinical FUS platform for cell culture, ex vivo tissue, and awake stereotaxic in vivo delivery in one lightweight system, validated using glioblastoma as a disease model. Methods. We performed single-well FUS delivery to 96-well microplates, single-well delivery to freshly resected human glioblastoma tissue, and stereotaxic transcranial delivery to awake, head-fixed mice ambulating freely on a floating cage. Output was independently calibrated in free field, with measured microplate insertion loss. Pulsed low-intensity focused ultrasound (pLIFU) was applied to GL261-bearing mice, resected human glioblastoma, and macrophage cell lines. Results. Awake stereotaxic pLIFU produced acute tumor signal attenuation in GL261-bearing mice (mean log2 fold-change -1.66 versus +5.20 controls, p = 0.016) with bioluminescence evidence consistent with focal targeting. Ex vivo pLIFU produced directionally consistent immunophenotypic shifts in human glioblastoma (increased iNOS+, decreased Arg1+ populations). In vitro, pLIFU reduced CD80 on immunosuppressive macrophages to 73% of baseline in RAW 264.7 cells (p = 0.0008, n = 5) and 64% in THP-1 cells (p = 0.0006, n = 2), with MHC II upregulation in RAW 264.7 (ratio 1.65, p = 0.004) and ARG1 reduction in THP-1 (ratio 0.52, p = 0.0025). Conclusions. A unified preclinical FUS platform validated across in vitro, ex vivo, and awake in vivo applications enables stereotaxically guided transcranial FUS in awake, head-fixed mice ambulating in an exploratory manner during sonication, and single-well microplate treatments.

neuroscience↗

bioRxiv2022

Mucosal gene expression in response to SARS-CoV-2 is associated with early viral load.

Little is known about the relationships between symptomatic early-time SARS-CoV-2 viral load and upper airway mucosal gene expression and immune response. To examine the association of symptomatic SARS-CoV-2 early viral load with upper airway mucosal gene expression, we profiled the host mucosal transcriptome from nasopharyngeal swab samples from 68 adults with symptomatic, mild-to-moderate COVID-19. We measured SARS-CoV-2 viral load using qRT-PCR. We then examined the association of SARS-CoV-2 viral load with upper airway mucosal immune response. We detected SARS-CoV-2 in all samples and recovered >80% of the genome from 85% of the samples from symptomatic COVID-19 adults. The respiratory virome was dominated by SARS-CoV-2, with limited co-detection of common respiratory viruses i.e., only the human Rhinovirus (HRV) being identified in 6% of the samples. We observed a significant positive correlation between SARS-CoV-2 viral load and interferon signaling (OAS2, OAS3, IFIT1, UPS18, ISG15, ISG20, IFITM1, and OASL), chemokine signaling (CXCL10 and CXCL11), and adaptive immune system (IFITM1, CD300E, and SIGLEC1) genes in symptomatic, mild-to-moderate COVID-19 adults, when adjusted for age, sex and race. Interestingly, the expression levels of most of these genes plateaued at a CT value of ~25. Overall, our data shows that early nasal mucosal immune response to SARS-CoV-2 infection is viral load dependent, which potentially could modify COVID-19 outcomes. AUTHOR SUMMARYSeveral prior studies have shown that SARS-CoV-2 viral load can predict the likelihood of disease spread and severity. A higher detectable SARS-CoV-2 plasma viral load was associated with worse respiratory disease severity. However, the relationship between SARS-CoV-2 viral load and airway mucosal gene expression and immune response remains elusive. We profiled the nasal mucosal transcriptome from nasal samples collected from adults infected with SARS-CoV-2 during Spring 2020 with mild-to-moderate symptoms using a comprehensive metatranscriptomics method. We observed a positive correlation between SARS-CoV-2 viral load with interferon signaling, chemokine signaling, and adaptive immune system in adults with COVID-19. Our data suggest that early nasal mucosal immune response to SARS-CoV-2 infection was viral load-dependent and may modify COVID-19 outcomes.

genomics↗

bioRxiv2021

BRG1 defines a genomic subset of inflammatory genes transcriptionally controlled by the glucocorticoid receptor

Glucocorticoids (such as Dexamethasone) are commonly used immunomodulatory drugs with potent anti-inflammatory effects, whose mechanisms of action remain incompletely understood. They bind to the Glucocorticoid Receptor (GR), a nuclear hormone receptor that acts as a transcription factor to directly control the expression of inflammatory genes. To elucidate the complex molecular mechanisms employed by GR during the suppression of innate immune responses, we have performed proteomics, ChIP-seq, ATAC-seq, RNA-seq and bioinformatics together with genetic and pharmacological loss of function studies in primary mouse macrophages. We found that GR interacts with the ATP-dependent SWI/SNF chromatin remodeling complex to regulate a specific subset of target genes. Here we show that the central catalytic subunit BRG1 is required not only for the transcriptional activation of classical GR target genes such as Fkbp5 or Klf9, but also for the transcriptional repression of cytokines and chemokines such as Ccl2, Cxcl10 or Il1a. We demonstrate that loss of BRG1 activity leads to reduced histone deacetylase (HDAC) function, and consequently increased histone acetylation, at these repressive GR binding sites. Altogether, our findings suggest that GR interacts with BRG1 to assemble a functional co-repressor complex at a defined fraction of macrophage cis-regulatory elements. These results may indicate additional non-classical, remodeling-independent functions of the SWI/SNF complex and may have implications for the development of future immunomodulatory therapies. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=50 SRC="FIGDIR/small/472398v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@1d9d238org.highwire.dtl.DTLVardef@1788bb1org.highwire.dtl.DTLVardef@11b3d4dorg.highwire.dtl.DTLVardef@155b9fc_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical Abstract.C_FLOATNO In macrophages (m{Phi}) responding to bacterial LPS and Dexamethasone, the Glucocorticoid Receptor (GR) activates target genes like Klf9 or Fkbp5 via interaction with the BRG1-containing SWI/SNF complex, chromatin remodeling and Mediator recruitment. At the same time, GR represses the expression of inflammatory cytokines and chemokines such as Ccl2, Cxcl10, Il1a etc. by assembling a BRG1-containing co-repressor complex and de-acetylating surrounding histone tails. Loss of BRG1 activity affects both the transcriptional activation and repression of a subset of myeloid GR target genes via distinct mechanisms. (iTF: inflammatory transcription factor; Ac: histone acetylation) (Created with BioRender.com.) C_FIG

genomics↗