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Biology subjects

Lai, H.-M.

Publications and source records attributed to Lai, H.-M..

5 recordsLinked to original sources

REZCUE: Rescuing 3D spatial omics from archived FFPE tissue

Archived formalin-fixed, paraffin-embedded (FFPE) tissue represents a vast clinical resource, yet three-dimensional imaging and molecular profiling remain largely incompatible because current antigen retrieval and clearing can degrade nucleic acids. We developed REZCUE, a depth-invariant antigen retrieval chemistry based on in situ protein refolding that enables 3D multiplexed immunofluorescence imaging of intact FFPE tissue while preserving DNA, RNA, and protein for subsequent assays. REZCUE restores antigenicity in tissue archived for up to 30 years, supports 160 commercial antibodies across tissue types, and enables imaging to 4 mm depth. Imaging before destructive molecular profiling establishes a 3D spatial reference for registering molecular assays to intact tissue architecture. In a 25-year-archived breast cancer specimen, REZCUE integrated 3D image-guided clonal segmentation with spatial transcriptomics, mass spectrometry, miRNA sequencing, and whole-genome sequencing, identifying a luminalB/HER2-positive clone missed by conventional section-based spatial-omics. REZCUE transforms archived FFPE specimens into spatially registered substrates for sequential 3D multi-omic interrogation.

bioengineering↗

A neural circuit basis for bilateral olfactory input-enhanced chemosensory avoidance navigation

Our understanding of how bilaterian animals utilize parallel input channels from paired sensory organs to optimize chemosensory behavior and the underlying neural circuit mechanisms are limited. Here we developed microfluidics-based behavioral and brainwide imaging platforms to study the neural integration of binasal inputs and chemosensory avoidance in larval zebrafish. We show that larval zebrafish efficiently escape from cadaverine-carrying streams by making more frequent swim bouts and larger undirected turns. Binasal inputs are strictly required for the nasal input-dependent component of klinokinesis, while each nasal input additively enhances angular orthokinesis. Throughout brain regions, including those along the olfactory processing pathways, a distributed neural representation with a wide spectrum of ipsilateral-contralateral nasal stimulus selectivity is maintained. Nonlinear sensory information gain with bilateral signal convergence is especially prominent in neurons weakly encoding unilateral cadaverine stimulus, and associated with stronger activation of sensorimotor neurons in the downstream brain regions. Collectively, these results provide insights into how the vertebrate model sums parallel input signals to guide chemosensory avoidance behavior.

neuroscience↗

Genome-wide reversal of glial and neurovascular cell transcriptomic aging signatures by GLP-1R agonism

Pharmacological reversal of brain aging is a long-sought yet challenging strategy for the prevention and treatment of age-related neurodegeneration, due to the diverse cell types and complex cellular pathways impacted by the aging process. Here, we report the genome-wide reversal of transcriptomic aging signatures in multiple major brain cell types, including glial and mural cells, by glucagon-like peptide-1 receptor (GLP-1R) agonist (GLP-1RA) treatment. The age-related expression changes reversed by GLP-1RA encompass both shared and cell type-specific functional pathways that are implicated in aging and neurodegeneration. Concomitantly, Alzheimers disease (AD)-associated transcriptomic signature in microglia that arises from aging is reduced. These results show the feasibility of reversing brain aging by pharmacological means, provide mechanistic insights into the neurological benefits of GLP-1RAs in diabetic patients, and imply that GLP-1R agonism may be a generally applicable pharmacological intervention for patients at risk of age-related neurodegeneration.

neuroscience↗

Simeprevir suppresses SARS-CoV-2 replication and synergizes with remdesivir

The outbreak of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global threat to human health. Using a multidisciplinary approach, we identified and validated the hepatitis C virus (HCV) protease inhibitor simeprevir as an especially promising repurposable drug for treating COVID-19. Simeprevir potently reduces SARS-CoV-2 viral load by multiple orders of magnitude and synergizes with remdesivir in vitro. Mechanistically, we showed that simeprevir inhibits the main protease (Mpro) and unexpectedly the RNA-dependent RNA polymerase (RdRp). Our results thus reveal the viral protein targets of simeprevir, and provide preclinical rationale for the combination of simeprevir and remdesivir for the pharmacological management of COVID-19 patients. One Sentence SummaryDiscovery of simeprevir as a potent suppressor of SARS-CoV-2 viral replication that synergizes with remdesivir.

microbiology↗

Zonation-dependent single-endothelial cell transcriptomic changes in the aged brain

With advances in single-cell genomics, molecular signatures of cells comprising the brain vasculature are revealed in unprecedented detail1,2, yet the ageing-associated cell subtype transcriptomic changes which may contribute to neurovascular dysfunction in neurodegenerative diseases3-7 remain elusive. Here, we performed single-cell transcriptomic profiling of brain endothelial cells (EC) in young adult and aged mice to characterize their ageing-associated genome-wide expression changes. We identified zonation-dependent transcriptomic changes in aged brain EC subtypes, with capillary ECs exhibiting the most transcriptomic alterations. Pathway enrichment analysis revealed altered immune/cytokine signaling in ECs of all vascular segments, while functional changes impacting the blood-brain barrier (BBB) and glucose/energy metabolism were most prominently implicated in ECs of the capillary bed - the primary site where ECs and other neurovascular unit (NVU) cell types closely interact and coordinate to regulate BBB and cerebral blood flow in health and diseased conditions8-17. Furthermore, an overrepresentation of Alzheimers disease (AD)-associated genes identified from GWAS studies was evident among the human orthologs of differentially expressed genes of aged capillary ECs but not other EC subtypes. Importantly, for numerous EC-enriched differentially expressed genes with important functional roles at the BBB and/or association with AD, we found concordant expression changes in human aged or AD brains. Finally, we demonstrated that treatment with exenatide, a glucagon-like peptide-1 receptor (GLP-1R) agonist, strongly reverses transcriptomic changes in ECs and largely reduces BBB leakage in the aged brain. Thus, our study provides insights into detailed transcriptomic alterations underlying brain EC ageing that are complex with subtype specificity yet amenable to pharmacological interventions.

neuroscience↗