Biology subjects

Liang, O. D.

Publications and source records attributed to Liang, O. D..

6 recordsLinked to original sources

bioRxiv2026

Impaired SOX17 Expression Causes Endothelial Dysfunction and Pulmonary Arterial Hypertension by Insufficient Suppression of RUNX1

Genome-wide association studies have identified rare and common mutations associated with increased risk of pulmonary arterial hypertension (PAH), but the mechanism by which impaired SOX17 expression increases PAH risk is not known. Notably, SOX17 plays a critical role in endothelial identity during development by suppressing RUNX1 through binding to its promoter and directing stem and progenitor cells toward an endothelial rather than a hematopoietic cell fate. RUNX1 functions as a key regulator of myeloid differentiation, aberrant angiogenesis and adverse cardiac remodeling. Previously, we found that RUNX1 inhibition reverses pulmonary hypertension (PH) in multiple animal models. Here, we hypothesize that impaired expression of SOX17 in PAH leads to endothelial cell (EC) dysfunction by failing to suppress RUNX1. METHODSHuman pulmonary artery endothelial cells (HPAECs) with stable SOX17 CRISPR/Cas9 knockout or RUNX1 overexpression were generated and examined for endothelial and hematopoietic gene expression, proliferation, migration, apoptosis, and angiogenesis. Immortalized lymphoblastoid cell lines (LCLs) from PAH patients with SOX17 mutations and healthy controls were reprogrammed into induced pluripotent stem cells (iPSCs) and differentiated into ECs. The effect of RUNX1 inhibition on Sugen/hypoxia-PH was examined in rats, SOX17 enhancer knockout (SOX17enhKO) mice, and Cdh5-CreERT2;Runx1(flox/flox);SOX17enhKO triple transgenic mice. SOX17 and RUNX1 expression were analyzed in peripheral blood samples from PAH patients (n=359). RESULTSHPAECs with SOX17 deletion or RUNX1 overexpression exhibited decreased expression of EC markers, enhanced proliferation and migration, defective angiogenesis, and decreased apoptosis. RUNX1 siRNA knockdown or RUNX1 inhibition by Ro5-3335 partially restored the endothelial properties in SOX17 KO HPAECs. ECs differentiated from SOX17 mutant PAH patient iPSCs exhibited upregulated RUNX1 expression and loss of endothelial identity, which was also partially restored by RUNX1 siRNA or Ro5-3335. In addition, SOX17enhKO mice had increased RUNX1 expression and susceptibility to Sugen/hypoxia-induced PH (SuHx-PH). Treatment with RUNX1 inhibitors or inducible endothelial-specific deletion of RUNX1 rescued SuHx-PH susceptibility in SOX17enhKO mice. RUNX1 inhibitors Ro5-3335 and Ro24-7429 also reversed SuHx-PH in wild-type rats. In addition, plasma RUNX1 expression was higher in PAH patients lacking detectable SOX17 expression than in patients with detectable SOX17 expression. CONCLUSIONSImpaired SOX17 expression increases the risk of PAH through insufficient suppression of RUNX1, leading to pulmonary endothelial dysfunction. RUNX1 inhibition mitigates PH associated with SOX17 deficiency and may represent a novel therapeutic strategy for PAH, especially those with rare or common SOX17 mutations.

cell biology↗

bioRxiv2025

The Liver is an Inflammatory Mediator of Pulmonary Arterial Hypertension

The livers contribution to pulmonary arterial hypertension (PAH) pathogenesis remains unclear. We hypothesized that the liver promotes inflammatory injury to the pulmonary endothelium. PAH patients without liver disease with pulmonary artery endothelial cell (PAEC) biopsies were included. Liver serologies and imaging were analyzed by unsupervised classification and regression tree (CART) to identify subclinical liver dysfunction clusters. Two machine-learning models predicted cluster assignment and informed differential expression. PAEC transcriptomes were compared to liver and lung data from monocrotaline and Sugen-Hypoxia rats. Liver fibrosis was assessed in rat and human PAH livers. Among 25 PAH patients (76% female, median age 61 [30 - 84] years), CART identified clusters distinguished by Model for End-Stage Liver Disease Sodium (MELD-Na) [≥]12, predicting higher pulmonary vascular resistance ({beta}=0.5 Wood units per point increase in MELD-Na, 95% CI 0.2-0.8, p=0.005) after adjustment for right atrial pressure. Subjects with MELD-Na [≥]12 had decreased 6-minute walk distance (353 [120 - 576] m vs. 411[300 - 600] m, p=0.03), with upregulation of apelin, beta-catenin, and immune signaling. Rat lung ECs demonstrated survival and hepatic growth-factor signaling, while rat livers showed immune activation. Rat (20.8 vs 16.6 % area stained, p=0.09) and human PAH livers revealed fibrosis despite absent right ventricular failure, supporting a pathogenic lung-liver axis in PAH.

cell biology↗

bioRxiv2025

Liver angiocrine myeloid-derived growth factor protects against endothelial dysfunction in pulmonary arterial hypertension

Myeloid-derived growth factor (MYDGF) is a hepatic angiokine with protective effects in systemic vascular beds, but its role in pulmonary arterial hypertension (PAH) is unknown. We hypothesized that hepatic MYDGF deficiency contributes to pulmonary endothelial activation in PAH and that recombinant MYDGF could rescue endothelial injury. In the Sugen-hypoxia (SuHx) rat model, hepatic MYDGF expression was decreased, while pulmonary vascular cell adhesion molecule-1 (VCAM-1) expression was increased. Human hepatic sinusoidal endothelial cells exposed to pro-inflammatory macrophage conditioned media downregulated MYDGF, and recombinant MYDGF restored pulmonary artery endothelial cell resistance to inflammatory activation via MAP4K4-NF{kappa}B signaling. In the Brown University PHiNE PAH cohort (n=41 PAH, n=27 controls), plasma proteomics demonstrated increased MYDGF in PAH patients compared with controls, but MYDGF levels declined with worsening liver stiffness and correlated with higher pulmonary vascular resistance. In the independent Servetus PAH cohort (n=117), higher plasma MYDGF was associated with mortality and right ventricular dilation. Together, these findings demonstrate hepatic MYDGF deficiency in experimental PAH, tissue specificity of endothelial MYDGF to the liver, and MYDGFs potential to mitigate pulmonary endothelial inflammation. However, human data suggest a paradoxical association of elevated circulating MYDGF with adverse outcomes, underscoring the complex biology of angiogenic growth factors in PAH. MYDGF may represent a novel hepatic angiokine linking systemic inflammation, liver dysfunction, and pulmonary vascular disease.

molecular biology↗

bioRxiv2025

Myeloid Specific Ablation of SHIP1 Boosts ex vivo Expansion and Regulatory Function of Myeloid-Derived Suppressor Cells in Inflammatory Arthritis

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous cell population and the immunosuppressive function of MDSCs has been well established in tumor microenvironment. Recent studies show that adoptive transfer of MDSCs can ameliorate collagen-induced inflammatory arthritis (CIA), a mouse model of human rheumatoid arthritis (RA). Src homology 2 domain- containing inositol polyphosphate 5-phosphatase 1 (SHIP1) was previously shown to regulate MDSC differentiation. In this study, we aimed to generate immunosuppressive MDSCs from mouse bone marrow (BM) through genetic modification combined with cytokine treatments, and to investigate the ability of these ex vivo induced BM-MDSCs to suppress inflammatory responses in the CIA mouse model of RA. We found that myeloid specific ablation of SHIP1 increased the ratio of MDSCs and enhanced their regulatory functions in cytokine induced BM culture. MDSCs from LysMcre:SHIP1flox/flox mouse BM culture demonstrated stronger inhibitory effect on T cell proliferation than those from control mouse BM. Ex vivo induced MDSCs from either control mice or mice with myeloid specific ablation of SHIP1 were administered to the CIA mice as a cell-based therapy to treat inflammatory arthritis. Adoptive transfer of either BM-MDSCs significantly reduced disease incidence and severity, but SHIP1 deficient BM-MDSCs exhibited even higher efficacy compared to wild-type BM-MDSCs. Furthermore, pharmacological inhibition of SHIP1 enhanced the expression of immune regulatory genes in BM-derived MDSCs, and adoptive transfer of these cells protected against CIA development. In conclusion, myeloid specific ablation of SHIP1 boosts ex vivo expansion and immune regulatory function of MDSCs in experimental inflammatory arthritis. These ex vivo generated BM-MDSCs may provide novel therapeutic opportunities for the treatment of RA and other inflammatory diseases.

immunology↗

bioRxiv2025

Enabling CAR-T Cell Immunotherapy in Glioblastoma by Modifying Tumor Microenvironment via Oncolytic Adenovirus Encoding Bispecific T Cell Engager

Recent clinical trials show that CAR-T cell therapies can initially blunt tumor growth in glioblastoma (GBM) patients. However, the tumor microenvironment activates mechanisms that inhibit tumor-killing potential of the CAR-T cells and limit their therapeutic efficacy. To counteract this, we have utilized oncolytic adenovirus (OV) Ad5-{Delta}24-RGD as a platform to overexpress a bispecific T cell engager (BiTE) targeting both T cell marker CD3 and GBM specific tumor associated antigen IL-13R2. We first demonstrated that OV-BiTE could enhance recruitment of T cells to GBM in vitro and in vivo. We then showed that intratumoral injection of OV-BiTE followed by infusion of combined EGFR- and EGFRvIII-CAR-T cells was more effective than OV-BiTE supplemented with either CAR-T therapy alone, and led to significant tumor eradication in a GBM xenograft mouse model. In conclusion, our multimodal OV-BiTE & CAR-T cell immunotherapy is capable of overcoming immunosuppressive tumor microenvironment and GBM resistance to treatment. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=160 SRC="FIGDIR/small/667708v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@c55b15org.highwire.dtl.DTLVardef@deffb2org.highwire.dtl.DTLVardef@64ff90org.highwire.dtl.DTLVardef@c65fc2_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTSO_LIOncolytic adenovirus encoding bispecific T cell engager (OV-BiTE) combines two immunotherapeutic agents into one. C_LIO_LIOV-BiTE strategy modifies tumor microenvironment and enhances recruitment of T cells to glioblastoma (GBM) in vitro and in vivo. C_LIO_LIMultimodal OV-BiTE & CAR-T cell immunotherapy effectively reduced tumor mass in a GBM xenograft mouse model and is superior to either immunotherapy alone. C_LI

cancer biology↗

bioRxiv2021

LRRC15 is an inhibitory receptor blocking SARS-CoV-2 spike-mediated entry in trans

SARS-CoV-2 infection is mediated by the entry receptor ACE2. Although attachment factors and co-receptors facilitating entry are extensively studied, cellular entry factors inhibiting viral entry are largely unknown. Using a surfaceome CRISPR activation screen, we identified human LRRC15 as an inhibitory receptor for SARS-CoV-2 entry. LRRC15 directly binds to the receptor-binding domain (RBD) of spike protein with a moderate affinity and inhibits spike-mediated entry. Analysis of human lung single cell RNA sequencing dataset reveals that expression of LRRC15 is primarily detected in fibroblasts and particularly enriched in pathological fibroblasts in COVID-19 patients. ACE2 and LRRC15 are not co-expressed in the same cell types in the lung. Strikingly, expression of LRRC15 in ACE2-negative cells blocks spike-mediated viral entry in ACE2+ cell in trans, suggesting a protective role of LRRC15 in a physiological context. Therefore, LRRC15 represents an inhibitory receptor for SARS-CoV-2 regulating viral entry in trans.

microbiology↗