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Chen, Y.-s.

Publications and source records attributed to Chen, Y.-s..

3 recordsLinked to original sources

Spatial Total RNA Sequencing of Formalin-Fixed Paraffin Embedded Tissues by spRandom-seq

Current oligo(dT) primers-based spatial transcriptomic methods are limited to fresh or fresh-frozen samples due to the low efficiency of oligo(dT) primers in capturing RNAs in degraded or microbial samples. Here, we have developed a random primer-based spatial total RNA sequencing (spRandom-seq) technology for simultaneously capturing whole host and microbial RNAs in formalin-fixed paraffin-embedded (FFPE) tissues. spRandom-seq eliminated 3 or 5 gene-body biases and outperformed oligo(dT)-based 10X Visium with an 8-fold higher capturing rate for lncRNA and other non-polyadenylated RNA biotypes, including miRNA, snRNA and miscRNA. In the clinical FFPE sections of breast cancer, we revealed the inherent heterogeneity within the tumor region. We also simultaneously captured host and microbial RNAs in Klebsiella pneumoniae-infected sections. Totally, spRandom-seq provided a versatile tool for both clinical pathology and infection biology with established spatial platforms, ensuring ease of operation and large-scale applications.

genomics↗

Identifying dynamic protein and RNA proximity interaction networks of actinin reveals RNA-binding and metabolic regulatory mechanisms

RationaleActinins are actin cross-linkers that are ubiquitously expressed and harbor mutations in heritable diseases. The predominant cardiac actinin is encoded by ACTN2, which is a core structural component of the sarcomere Z-disk. ACTN2 is required for sarcomere function through complex interactions with proteins involved in sarcomere assembly, cell signaling and transcriptional regulation. However, there remain critical gaps in our knowledge of the complete and dynamic cardiac actinin interactome, which could reveal new insights into sarcomere biology. ObjectiveWe sought to examine the cardiac actinin interactome through sarcomere assembly in human cardiomyocytes. Methods and ResultsWe utilized CRISPR/Cas9, induced pluripotent stem cell technology and BioID to reveal cardiac actinin protein interactions in human cardiomyocytes. We identified 324 cardiac actinin proximity partners, analyzed networks, and studied interactome changes associated with sarcomere assembly. We focused additional studies on unexpected actinin interactions with effectors with RNA-binding functions. Using RNA immunoprecipitation followed by sequencing, we determined that RNA-binding partners uncovered by actinin BioID were bound to gene transcripts with electron transport chain and mitochondrial biogenesis functions. Mammalian two-hybrid studies established that IGF2BP2, an RNA-binding protein associated with type 2 diabetes, directly interacted with the rod domain of actinin through its K Homology domain. IGF2BP2 was necessary for electron transport chain transcript localization to vicinal RNA-binding proteins, mitochondrial mass and oxidative metabolism. IGF2BP2 knockdown also impaired sarcomere function in a cardiac microtissue assay. ConclusionsThis study expands our functional knowledge of cardiac actinin, uncovers new sarcomere interaction partners including those regulated by sarcomere assembly, and reveals sarcomere crosstalk with RNA-binding proteins including IGF2BP2 that are important for metabolic functions.

cell biology↗

A contraction stress model of hypertrophic cardiomyopathy due to thick filament sarcomere mutations

Thick filament sarcomere mutations are the most common cause of hypertrophic cardiomyopathy (HCM), a disorder of heart muscle thickening associated with sudden cardiac death and heart failure, with unclear mechanisms. We engineered an isogenic panel of four human HCM induced pluripotent stem cell (iPSc) models using CRISPR/Cas9, and studied iPSc-derived cardiomyocytes (iCMs) in 3-dimensional cardiac microtissue (CMT) assays that resemble in vivo cardiac architecture and biomechanics. HCM mutations result in hypercontractility in association with prolonged relaxation kinetics in proportion to mutation pathogenicity but not calcium dysregulation. RNA sequencing and protein expression studies identified that HCM mutations result in p53 activation secondary to increased oxidative stress, which results in increased cytotoxicity that can be reversed by p53 genetic ablation. Our findings implicate hypercontractility as an early consequence of thick filament mutations, and the p53 pathway as a molecular marker and candidate therapeutic target for thick filament HCM.

cell biology↗