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Biology subjects

Park, W. Y.

Publications and source records attributed to Park, W. Y..

4 recordsLinked to original sources

Pan-cancer single-cell analysis identifies a FOXF1/FOXF2-associated transitional CAF-like fibroblast state

Fibroblast heterogeneity shapes tumor progression, yet the transitional states linking normal-associated fibroblasts to cancer-associated fibroblasts (CAFs) remain poorly defined. Here, we integrated single-cell transcriptomic profiles of more than 90,000 stromal cells from 281 samples across nine cancer types to construct a pan-cancer atlas of fibroblast diversity. We identified a distinct CAF-like population positioned between normal-activated fibroblasts and established CAF subsets along the inferred fibroblast activation trajectory. Integration with single-nucleus chromatin accessibility data nominated FOXF1 and FOXF2 as candidate regulators of this CAF-like state. Functionally, CAF-like fibroblasts were characterized by non-canonical WNT activity, WNT5A-associated stromal communication, and a candidate GZMA-F2R/PAR immune-stromal signaling axis supported by spatial transcriptomics. Clinically, the CAF-like signature showed context-dependent prognostic relevance, with high expression associated with poorer survival in the tumor compartment of TCGA stomach adenocarcinoma. Together, this study defines a FOXF1/FOXF2-associated CAF-like transitional fibroblast state and links it to stromal signaling, immune-stromal communication, and cancer-type-specific clinical relevance.

cancer biology↗

Systemic inhibition of de novo purine biosynthesis prevents weight gain and improves metabolic health by increasing thermogenesis and decreasing food intake

ObjectiveObesity is a major health concern, largely because it contributes to type 2 diabetes mellitus (T2DM), cardiovascular disease, and various malignancies. Increase in circulating amino acids and lipids, in part due to adipose dysfunction, have been shown to drive obesity-mediated diseases. Similarly, elevated purines and uric acid, a degradation product of purine metabolism, are found in the bloodstream and in adipose tissue. These metabolic changes are correlated with metabolic syndrome, but little is known about the physiological effects of targeting purine biosynthesis. MethodsTo determine the effects of purine biosynthesis on organismal health we treated mice with mizoribine, an inhibitor of inosine monophosphate dehydrogenase 1 and 2 (IMPDH1/2), key enzymes in this pathway. Mice were fed either a low-fat (LFD; 13.5% kcal from fat) or a high-fat (HFD; 60% kcal from fat) diet for 30 days during drug or vehicle treatment. We ascertained the effects of mizoribine on weight gain, body composition, food intake and absorption, energy expenditure, and overall metabolic health. ResultsMizoribine treatment prevented mice on a HFD from gaining weight, but had no effect on mice on a LFD. Body composition analysis demonstrated that mizoribine significantly reduced fat mass but did not affect lean mass. Although mizoribine had no effect on lipid absorption, food intake was reduced. Furthermore, mizoribine treatment induced adaptive thermogenesis in skeletal muscle by upregulating sarcolipin, a regulator of muscle thermogenesis. While mizoribine-treated mice exhibited less adipose tissue than controls, we did not observe lipotoxicity. Rather, mizoribine-treated mice displayed improved glucose tolerance and reduced ectopic lipid accumulation. ConclusionsInhibiting purine biosynthesis prevents mice on a HFD from gaining weight, and improves their metabolic health, to a significant degree. We also demonstrated that the purine biosynthesis pathway plays a previously unknown role in skeletal muscle thermogenesis. A deeper mechanistic understanding of how purine biosynthesis promotes thermogenesis and decreases food intake may pave the way to new anti-obesity therapies. Crucially, given that many purine inhibitors have been FDA-approved for use in treating various conditions, our results indicate that they may benefit overweight or obese patients. HighlightsO_LIA purine biosynthesis inhibitor, mizoribine, protects against diet-induced weight gain C_LIO_LIMizoribine prevents fat mass gain in high-fat diet-fed male mice C_LIO_LIMizoribine reduces food intake and increases thermogenesis C_LIO_LIMizoribine induces expression of sarcolipin, a regulator of thermogenesis C_LIO_LIMizoribine treatment reduces ectopic lipids and increases glucose tolerance C_LI

physiology↗

Open-top Bessel beam two-photon light sheet microscopy for three-dimensional pathology

Nondestructive pathology based on three-dimensional (3D) optical microscopy holds promise as a complement to traditional destructive hematoxylin and eosin (H&E) stained slide-based pathology by providing cellular information in high throughput manner. However, conventional techniques provided superficial information only due to shallow imaging depths. Herein, we developed open-top two-photon light sheet microscopy (OT-TP-LSM) for intraoperative 3D pathology. An extended depth of field two-photon excitation light sheet was generated by scanning a nondiffractive Bessel beam, and selective planar imaging was conducted with cameras at 400 frames/s max during the lateral translation of tissue specimens. Intrinsic second harmonic generation was collected for additional extracellular matrix (ECM) visualization. OT-TP-LSM was tested in various human cancer specimens including skin, pancreas, and prostate. High imaging depths were achieved owing to long excitation wavelengths and long wavelength fluorophores. 3D visualization of both cells and ECM enhanced the ability of cancer detection. Furthermore, an unsupervised deep learning network was employed for the style transfer of OT-TP-LSM images to virtual H&E images. The virtual H&E images exhibited comparable histological characteristics to real ones. OT-TP-LSM may have the potential for histopathological examination in surgical and biopsy applications by rapidly providing 3D information.

pathology↗

Monopogen: single nucleotide variant calling from single cell sequencing

Distinguishing how genetics impact cellular processes can improve our understanding of variable risk for diseases. Although single-cell omics have provided molecular characterization of cell types and states on diverse tissue samples, their genetic ancestry and effects on cellular molecular traits are largely understudied. Here, we developed Monopogen, a computational tool enabling researchers to detect single nucleotide variants (SNVs) from a variety of single cell transcriptomic and epigenomic sequencing data. It leverages linkage disequilibrium from external reference panels to identify germline SNVs from sparse sequencing data and uses Monovar to identify novel SNVs at cluster (or cell type) levels. Monopogen can identify 100K~3M germline SNVs from various single cell sequencing platforms (scRNA-seq, snRNA-seq, snATAC-seq etc), with genotyping accuracy higher than 95%, when compared against matched whole genome sequencing data. We applied Monopogen on human retina, normal breast and Asian immune diversity atlases, showing that that derived genotypes enable accurate global and local ancestry inference and identification of admixed samples from ancestrally diverse donors. In addition, we applied Monopogen on ~4M cells from 65 human heart left ventricle single cell samples and identified novel variants associated with cardiomyocyte metabolic levels and epigenomic programs. In summary, Monopogen provides a novel computational framework that brings together population genetics and single cell omics to uncover genetic determinants of cellular quantitative traits.

bioinformatics↗