Biology subjects

Yu, J. J.

Publications and source records attributed to Yu, J. J..

12 recordsLinked to original sources

bioRxiv2025

Decoding Lymphangioleiomyomatosis (LAM) Niche Environment via Integrative Analysis of Single Cell Multiomics and Spatial Transcriptomics

Lymphangioleiomyomatosis (LAM) is a rare, progressive lung disease characterized by cystic destruction and metastatic growth of smooth muscle-like cells. Despite advances in understanding its genetic basis, the cellular heterogeneity, regulatory mechanisms, and microenvironmental interactions driving LAM progression remain poorly defined. In this study, we employed an integrative multi-omics approach combining single-cell RNA sequencing (scRNA-seq), single-nucleus ATAC sequencing (snATAC-seq), and high-resolution spatial transcriptomics (Visium, Visium HD, and Xenium) to decode the LAM niche in its native environment. We identified two spatially and functionally distinct LAM subtypes: LAMCORE1 and LAMCORE2. LAMCORE1 cells exhibited a uterine smooth muscle-like phenotype, expressing associated markers (ACTA2, MYH11) and were enriched in MTORC1 signaling and myogenic pathways, supporting a uterine origin. In contrast, LAMCORE2 cells displayed fibroblast-like features, with upregulated extracellular matrix (ECM) remodeling genes (COL1A1, MMP11) and epithelial-to-mesenchymal transition (EMT) pathways, suggesting a role in niche formation. Pseudotime and regulon analyses revealed dynamic transitions between these subtypes, driven by distinct transcriptional networks (e.g., HOX/PBX in LAMCORE1, TWIST/ZEB in LAMCORE2). The presence of the two distinct LAM subtypes was further validated by RNAscope and immunofluorescence microscopy. We identified LAM-associated fibroblasts (LAFs) as activated stromal cells expressing canonical markers (FAP, S100A4, VIM, IGFBP7, SPARC) and localized within LAM lesions. Subpopulations of LAFs, LAF-seed (proximal to LAMCORE1) and LAF-niche (surrounding LAM niches), exhibited unique functional profiles, including ECM deposition, TGF-{beta} signaling, and myofibroblast activation. Regulatory network analysis pinpointed EGR1 as a central hub governing LAF phenotype. Our comprehensive spatial profiling revealed niche structures dominated by LAMCORE1 cells and surrounded by lymphatic endothelial cells (LECs), LAFs, scattered LAMCORE2 cells, macrophages, and reprogrammed alveolar epithelial cells (AT2). ECM remodeling and aberrant organization of cable-like structures (-smooth muscle actin+) of the LAM niches were further validated by second harmonic generation microscopy. These findings provide a high-resolution blueprint of LAM pathogenesis, highlighting the interplay between uterine-derived LAMCORE cells, activated fibroblasts, and the remodeled lung microenvironment. They significantly enhance our understanding of the LAM niche microenvironment and offer insights into potential therapeutic targets and strategies for managing this complex disease.

genomics↗

bioRxiv2025

Amyloid pathology reduces dynamic range and disrupts neural coding in a mouse model of Alzheimer's Disease

Alzheimers disease (AD) disrupts neural circuits vital for memory and cognition. Using two-photon calcium imaging in behaving 5xFAD mice, we examined how amyloid pathology alters hippocampal CA1 activity and spatial coding. We found elevated baseline activity but reduced locomotion-driven firing, leading to a diminished neuronal dynamic range. To our knowledge, this is the first direct experimental evidence for reduced dynamic range in an AD model. These abnormalities were strongest near amyloid plaques and became more widespread with age. We also observed altered network synchrony, degraded spatial coding and increased neuronal response variability. Furthermore, place fields emerged more slowly in both familiar and novel environments, indicating impaired recall and learning. By showing a link between local plaque pathology and impaired flexible modulation of CA1 activity and progressive deficits in spatial memory coding, our study offers new insights into the circuit basis of cognitive decline in AD.

neuroscience↗

bioRxiv2024

STAT1 Promotes PD-L1 Activation and Tumor Growth in Lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a cystic lung disease that primarily affects women. LAM is caused by the invasion of metastatic smooth muscle-like cells into the lung parenchyma, leading to abnormal cell proliferation, lung remodeling and progressive respiratory failure. LAM cells have TSC gene mutations, which occur sporadically or in people with Tuberous Sclerosis Complex. Although it is known that hyperactivation of the mechanistic target of rapamycin complex 1 (mTORC1) due to TSC2 gene mutations contributes to aberrant cell growth in LAM lung, tumor origin and invasive mechanism remain unclear. To determine molecular drivers responsible for aberrant LAM cell growth, we performed integrative single-cell transcriptomic analysis and predicted that STAT1 interacts with Pre-B cell leukemia transcription factor (PBX1) to regulate LAM cell survival. Here, we show activation of STAT1 and STAT3 proteins in TSC2- deficient LAM models. Fludarabine, a potent STAT1 inhibitor, induced the death of TSC2- deficient cells, increased caspase-3 cleavage, and phosphorylation of necroptosis marker RIP1. Fludarabine treatment impeded lung colonization of TSC2-deficient cells and uterine tumor progression, associated with reduced percentage of PCNA-positive cells in vivo. Interestingly, IFN-{gamma} treatment increased STAT1 phosphorylation and PD-L1 expression, indicating that STAT1 aids TSC2-deficient tumor cells in evading immune surveillance in LAM. Our findings indicate that STAT1 signaling is critical for LAM cell survival and could be targeted to treat LAM and other mTORC1 hyperactive tumors.

cancer biology↗

bioRxiv2024

Extracellular vesicles regulate metastable phenotypes of lymphangioleiomyomatosis cells via shuttling ATP synthesis to pseudopodia and activation of integrin adhesion complexes.

Pulmonary lymphangioleiomyomatosis (LAM) is metastatic sarcoma but mechanisms regulating LAM metastasis are unknown. Extracellular vesicle (EV) regulate cancer metastasis but their roles in LAM have not yet been investigated. Here, we report that EV biogenesis is increased in LAM and LAM EV cargo is enriched with lung tropic integrins, metalloproteinases, and cancer stem cell markers. LAM-EV increase LAM cell migration and invasion via the ITG6/{beta}1-c-Src-FAK-AKT axis. Metastable (hybrid) phenotypes of LAM metastasizing cells, pivotal for metastasis, are regulated by EV from primary tumor or metastasizing LAM cells via shuttling ATP synthesis to cell pseudopodia or activation of integrin adhesion complex, respectively. In mouse models of LAM, LAM-EV increase lung metastatic burden through mechanisms involving lung extracellular matrix remodeling. Collectively, these data provide evidence for the role of EV in promoting LAM lung metastasis and identify novel EV-dependent mechanisms regulating metastable phenotypes of tumor cells. Clinical impact of research is that it establishes LAM pathway as novel target for LAM therapy.

cancer biology↗

bioRxiv2024

Construction of Discrete Element Model of Different Moisture Hygroscopic Fertilizer Particles and Fertilizer Discharging Verification

The hygroscopic fertilizer particles were characterized based on discrete element simulation, and its accuracy was verified by the simulation of fertilizer discharge. Firstly, the repose angle of the fertilizer particles served as the key metric for assessment. A mathematical model characterizing the relationship between fertilizer moisture content and the repose angle was established, R2=0.9935; and a mathematical representation of the repose angle for fertilizer moisture content was established, R2=0.9933. Then, the moisture absorbing fertilizer particles was developed utilizing the integrated Hertz Mindlin with JKR model within EDEM system to account for particle adhesion; A robust correlation model between the repose angle of hygroscopic fertilizers and the discrete element method was established, p <0.0001; Finally, a correlation model between moisture content and significant parameters within the discrete element method was established, drawing upon the models for moisture content repose angle and repose angle discrete element parameters. The moisture-absorbing fertilizer particles model at moisture contents of 2% and 6% were resolved, with a relative error of the repose angle not exceeding 1.42% and a single circle fertilizer discharge error below 8.32%. The results show that the moisture content discrete element significant parameter correlation model can reliably and precisely forecast the discrete element parameters of various moisture content hygroscopic fertilizers. The hygroscopic fertilizer particle model can represent surface interaction characteristics of hygroscopic fertilizer granules. which has guiding significance for the design of precision fertilizer discharge technology device.

physiology↗

bioRxiv2023

Pulmonary osteoclast-like cells in silica induced pulmonary fibrosis

The pathophysiology of silicosis is poorly understood, limiting development of therapies for those who have been exposed to the respirable particle. We explored the mechanisms of silica-induced pulmonary fibrosis in a mouse model using multiple modalities including wholelung single-nucleus RNA sequencing. These analyses revealed that in addition to pulmonary inflammation and fibrosis, intratracheal silica challenge induced osteoclast-like differentiation of alveolar macrophages and recruited monocytes, driven by induction of the osteoclastogenic cytokine, receptor activator of nuclear factor-{kappa}B ligand (RANKL) in pulmonary lymphocytes and alveolar type II cells. Furthermore, anti-RANKL monoclonal antibody treatment suppressed silica-induced osteoclast-like differentiation in the lung and attenuated silica-induced pulmonary fibrosis. We conclude that silica induces osteoclast-like differentiation of distinct recruited and tissue resident monocyte populations, leading to progressive lung injury, likely due to sustained elaboration of bone resorbing proteases and hydrochloric acid. Interrupting osteoclast-like differentiation may therefore constitute a promising avenue for moderating lung damage in silicosis. One Sentence SummarySilica induces the alveolar epithelium to reprogram recruited and resident pulmonary myeloid cells to become osteoclasts that contribute to pulmonary fibrosis.

pathology↗

bioRxiv2022

Combination of Volasertib and Rapamycin Inhibits the Regrowth of TSC2-Deficient Tumors

Mutations in TSC1 and TSC2 lead to hyperactivation of mTORC1 and cause Tuberous Sclerosis Complex (TSC) and pulmonary Lymphangioleiomyomatosis (LAM). Rapamycin and rapalogs are potent inhibitors of mTORC1 activity and are approved for the treatment of TSC and LAM. Nevertheless, rapalogs do not cause tumor cell death, and cessation of therapy leads to tumor regrowth. Polo-like kinase 1 (PLK1) interacts with and phosphorylates TSC1, and PLK1 inhibition induces apoptosis and attenuates autophagy in TSC1/TSC2-deficient cells. Here we report that the PLK1 inhibitor volasertib decreases the viability and survival and induces apoptosis in 621-101 cells, a TSC-deficient renal angiomyolipoma cell line from a LAM patient. Combined with rapamycin, volasertib further decreased the survival of 621-101 cells. In vivo, volasertib reduced short-term mouse lung colonization by TSC2-deficient cells and decreased the growth of TSC2-deficient subcutaneous tumors. Mice treated with a combination of volasertib and rapamycin had slower tumor relapse after discontinuation of treatment, compared to rapamycin only. Approximately 35 days after discontinuation of treatment, we observed persistent apoptotic markers and gene expression changes for type I interferon signaling in the regrowth tumors from combination-treated mice, compared to rapamycin only. Notably, combination treatment potently inhibited the growth of subcutaneous tumors derived from the rapamycin-refractory cell line ELT3-245. Taken together, our current work demonstrates that for the management of TSC and LAM disease combination of mTORC1 and PLK1 inhibitors in some cases may be advantageous over currently used rapalog monotherapies.

cancer biology↗

bioRxiv2022

Integrative Single Cell Multiomic Profiling Analysis Reveals HOX-PBX Gene Regulatory Network Contributing to the Survival of mTOR Hyperactive Cells

Lymphangioleiomyomatosis (LAM) is a rare, debilitating lung disease that predominantly affects women of reproductive age. LAM is characterized by the infiltration of the lungs by abnormally proliferating smooth muscle-like cells of unknown origin via an estrogen-dependent metastatic mechanism. LAM cells carry deleterious mutations of tuberous sclerosis complex (TSC1/TSC2) genes, resulting in hyperactivation of the mechanistic target of rapamycin complex 1 (mTORC1) and ultimately dysregulated cell growth. Sirolimus, an FDA approved mTORC1 inhibitor and current best-choice medication for LAM stabilizes lung function in most LAM patients. However, it requires sustained application and remains inefficacious in some patients. The greatest barriers to finding a cure for LAM include its undetermined origin and unclear underlying pathogenesis. Our study aims to advance knowledge on the origin of LAM, and ultimately serve as a premise for the development of novel therapeutic targets for LAM. Single cell RNA sequencing (scRNA-seq) is a powerful tool in biomedical research that informs gene expression differences at the cellular level and may provide insights into the most fundamental origin of LAM cells. Our scRNA-seq analysis of LAM cells revealed a unique population of cells (LAMCORE), expressing uterine-similar homeobox transcription factors (HOX) and Pre-B-cell leukemia homeobox 1 (PBX1), which are absent in normal lung, suggesting that the uterus is the primary origin of LAM. PBX1 is a transcription factor critical for female reproductive tract development and maintenance, and its overexpression is implicated in some female reproductive cancers. In this study we hypothesize that PBX1 promotes survival and lung colonization of LAM (TSC2-null) cells. Using LAM patient-derived cells, we validated the transcriptional profile, gene expression and protein levels of PBX1. We have the first functional evidence that PBX1 and its downstream targets are upregulated in LAM cells. In a mouse model of LAM, we monitored the effect of suppression of PBX1 by short hairpin RNA-mediated gene silencing on lung colonization and tumor growth. We also found that pharmacological suppression of PBX1 attenuates LAM lung colonization and promotes death of LAM cells in vivo and vitro. Our data collectively suggests that PBX1 is a critical regulator of LAM progression.

cancer biology↗

bioRxiv2022

Dysregulation of Acid Ceramidase-mediated Sphingolipid Metabolism Contributes to Tumor Progression in Tuberous Sclerosis Complex

Tuberous Sclerosis Complex (TSC) is disorder of multi-system benign neoplasia in the brain, heart, kidneys and lungs. Lymphangioleiomyomatosis (LAM) is a progressive pulmonary disease affecting exclusively women. Both are caused by mutations in TSC1 and TSC2, resulting in mTORC1 hyperactivation. Single cell RNA sequencing of LAM lungs identified activation of genes in the sphingolipid pathway. Independent validation studies showed that acid ceramidase (ASAH1) and dihydroceramide desaturase (DEGS1), key enzyme for regulating sphingolipid and ceramide metabolism, were significantly increased in TSC2-null cells, and their expression and activity were rapamycin-insensitive. TSC2 negatively regulated the biosynthesis of tumorigenic sphingolipids. Suppression of ASAH1 by shRNA or the inhibitor ARN14976 (17a) markedly decreased the viability of TSC2-null cells. In vivo, 17a significantly decreased the growth of Tsc2-null cell derived mouse xenografts. When combined with rapamycin, 17a more strongly inhibited the progression of renal cystadenomas in Tsc2+/- mice than either agent alone, evaluated by pathology and MRI. Collectively, our studies identify a rapamycin-insensitive disorder of sphingolipid metabolism in TSC2-null cells and tumors and validate the novel hypothesis that TSC2 regulates sphingolipid production and action via ASAH1. Targeting aberrant sphingolipid metabolism pathways may have therapeutic value in TSC and LAM, and possibly in mTORC1-hyperactive neoplasms.

cell biology↗

bioRxiv2021

Novel insights into pulmonary phosphate homeostasis and osteoclastogenesis emerge from the study of pulmonary alveolar microlithiasis.

Pulmonary alveolar microlithiasis (PAM) is an autosomal recessive lung disease caused by a deficiency in the pulmonary epithelial Npt2b sodium-phosphate co-transporter that results in accumulation of phosphate and formation of hydroxyapatite microliths in the alveolar space. The single cell transcriptomic analysis of a PAM lung explant showing a robust osteoclast gene signature in alveolar monocytes and the finding that calcium phosphate microliths contain a rich protein and lipid matrix that includes bone resorbing osteoclast enzymes suggested a role for osteoclast-like cells in the defense against microliths. While investigating the mechanisms of microlith clearance, we found that Npt2b modulates pulmonary phosphate homeostasis through effects on alternative phosphate transporter activity and alveolar osteoprotegerin, and that microliths induce osteoclast formation and activity in a receptor activator of nuclear factor-{kappa}B ligand (RANKL) and dietary phosphate dependent manner. This work reveals that Npt2b and pulmonary osteoclast-like cells play key roles in pulmonary homeostasis and suggest potential new therapeutic targets for the treatment of lung disease.

molecular biology↗

bioRxiv2020

Connectivity analysis of single cell RNA-sequencing derived transcriptional signature of lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare pulmonary disease affecting women of childbearing age that is characterized by the aberrant proliferation of smooth-muscle (SM)-like cells and emphysema-like lung remodeling. In LAM, mutations in TSC1 or TSC2 genes results in the activation of the mechanistic target of rapamycin complex 1 (mTORC1) and thus sirolimus, an mTORC1 inhibitor, has been approved by FDA to treat LAM patients. Sirolimus stabilizes lung function and improves symptoms. However, the disease recurs with discontinuation of the drug, potentially because of the sirolimus-induced refractoriness of the LAM cells. Therefore, there is a critical need to identify remission inducing cytocidal treatments for LAM. Recently released Library of Integrated Network-based Cellular Signatures (LINCS) L1000 transcriptional signatures of chemical perturbations has opened new avenues to study cellular responses to existing drugs and new bioactive compounds. Connecting transcriptional signature of a disease to these chemical perturbation signatures to identify bioactive chemicals that can "revert" the disease signatures can lead to novel drug discovery. We developed methods for constructing disease transcriptional signatures and performing connectivity analysis using single cell RNA-seq data. The methods were applied in the analysis of scRNA-seq data of naive and sirolimus-treated LAM cells. The single cell connectivity analyses implicated mTORC1 inhibitors as capable of reverting the LAM transcriptional signatures while the corresponding standard bulk analysis did not. This indicates the importance of using single cell analysis in constructing disease signatures. The analysis also implicated other classes of drugs, CDK, MEK/MAPK and EGFR/JAK inhibitors, as potential therapeutic agents for LAM.

systems biology↗

bioRxiv2019

Identification of the lymphangioleiomyomatosis cell and its uterine origin

Lymphangioleiomyomatosis (LAM) is a metastasizing neoplasm of reproductive age women that causes cystic lung remodeling and progressive respiratory failure. The source of LAM cells that invade the lung and the reasons that LAM targets women have remained elusive. We employed single cell and single nuclei RNA sequencing on LAM lesions within explanted LAM lungs, known to contain smooth muscle like cells bearing mTOR activating mutations in TSC1 or TSC2, and identified a unique population of cells that were readily distinguished from those of endogenous lung cells. LAMCORE cells shared closest transcriptomic similarity to normal uterus and neural crest. Immunofluorescence microscopy demonstrated the expression of LAMCORE cell signature genes within LAM lesions in both lung and uterus. Serum aptamer proteomics and ELISA identified biomarkers predicted to be secreted by LAMCORE cells. Single cell transcriptomics strongly supports a uterine neural crest origin of LAMCORE cells; providing insights into disease pathogenesis and informing future treatment strategies for LAM.\n\nSIGNIFICANCEPresent study identified a novel population of LAMCORE cells, which is likely originated from uterine neural crest; identified novel LAM cell-specific secretome proteins that hold promise as potential biomarkers and therapeutic targets. Advancing the understanding of LAM pathogenesis and metastasis model may yield broader insights into the biology of cancer.

cancer biology↗