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Biology subjects

Wong, L. P.

Publications and source records attributed to Wong, L. P..

7 recordsLinked to original sources

Differentiation stage-specific use of cap-independent and cap-dependent translation initiation in hematopoiesis

Cell stress can increase the use of m7G-cap-independent, IRES-mediated translation initiation relative to cap-dependent translation (IRES/Cap). Reporters that quantify IRES/Cap have demonstrated differential activity across cultured cell types and stress conditions. By generating an IRES/Cap reporter mouse, we were able to systematically evaluate IRES/Cap across distinct tissues and cell types during physiological stresses and lineage commitment. Caloric stress invoked the expected boost in IRES/Cap translation regardless of differentiation state, but unexpectedly IRES/Cap progressively increased during hematopoietic and epithelial (hair follicle) differentiation under normal, homeostatic conditions. This was independent of total protein output or cell cycle. Even within cells of a given differentiation state, cells with lower relative-IRES utilization had markedly higher multipotent capability in vivo. The RNA processing protein PTBP1 is a mediator of this translation initiation preference. Therefore, low IRES/Cap is a signature of high stemness and suggests modulation of translation initiation participates in cell differentiation state.

developmental biology↗

Integrative reverse vaccinology approach for identification of a vaccine antigen candidate with immunoprotective and anti-fibrotic potential against Schistosoma japonicum-associated liver fibrosis

Schistosoma japonicum-associated liver fibrosis (SSLF) is a major cause of morbidity in Schistosomiasis, yet no licensed vaccines or specific therapies exist to prevent or treat this complication. Current vaccine development has focused mainly on infection prevention, with limited attention to pathology-driven outcomes such as fibrosis. To address this gap, we developed an in-silico pipeline integrating host single-cell transcriptomic analysis, parasite antigen screening, and structure-based modeling. Single-cell RNA-seq of liver tissues from SSLF and controls identified three fibrosis-related hub proteins: FYN, BCL2, and AKT3. In parallel, parasite antigens curated from public databases were evaluated for immunogenicity and safety using reverse vaccinology principles. Among these, DRE2_SCHJA, an Anamorsin homolog involved in Fe-S cluster assembly, was prioritized as the top candidate. Docking analysis predicted the strongest interaction between DRE2_SCHJA and FYN ({Delta}G = -14.9 kcal/mol), linking the antigen to a central regulator of fibrosis. Unlike Saracatinib, which inhibits FYN at the ATP-binding pocket, DRE2_SCHJA bound to the SH2 domain through both canonical and non-canonical contacts, indicating a different regulatory mechanism. Taken together, these findings suggest DRE2_SCHJA as a potential vaccine candidate with both protective and anti-fibrotic potential against SSLF. While experimental validation is required, this study supports the early identification of SSLF vaccine candidates in a rapid and cost-effective manner and provides a framework applicable to other neglected tropical diseases. Athor summarySchistosoma japonicum (S. japonicum) is a parasitic disease that remains a major health problem in parts of Asia, especially in China. One of its most harmful consequences is liver fibrosis, which causes long-term illness and reduces quality of life. Currently, there are no drugs or vaccines that specifically prevent or treat this condition. In this study, we used a fast and low-cost computer-based method to search for vaccine targets against liver fibrosis caused by S. japonicum. We identified a parasite protein that could serve as a vaccine target, with the potential to prevent fibrosis from developing and to slow its progression. If future studies confirm its role, such a vaccine could greatly improve the long-term health of people living with schistosomiasis and inspire new strategies for vaccine development in other neglected tropical diseases.

bioinformatics↗

Interrupting Elmsan1 repression of nuclear Acetyl-CoA production therapeutically reprograms cancer cells

Metabolites are essential substrates for epigenetic modifications. Although nuclear acetyl-CoA constitutes a small fraction of the whole cell pool, it regulates cell fate by locally providing histone acetylation substrate. Here, we combined phenotypic chemical screen and genome-wide CRISPR screen to demonstrate a nucleus-specific acetyl-CoA regulatory mechanism that can be modulated to achieve therapeutic cancer cell reprogramming. While previously thought that nucleus-localized pyruvate dehydrogenase complex (nPDC) is constitutively active, we found that nPDC is constitutively inhibited by the nuclear protein ELMSAN1 through direct interaction. Pharmacologic inhibition of the ELMSAN1-nPDC interaction derepressed nPDC activity, enhancing nuclear acetyl-CoA generation and reprogramming cancer cells to a postmitotic state with diminished cell-of-origin signatures. Reprogramming was synergistically enhanced by histone deacetylase 1/2 inhibition, resulting in inhibited tumor growth, durably suppressed tumor-initiating ability, and improved survival in multiple cancer types in vivo, including therapy-resistant sarcoma patient-derived xenografts and carcinoma cell line xenografts. Our findings highlight the potential of targeting ELMSAN1-nPDC as epigenetic cancer therapy.

cancer biology↗

Hematopoietic stem cells undergo bidirectional fate transitions in vivo.

Differentiation of haematopoietic stem and progenitor cells (HSPCs) is widely considered unidirectional in vivo. Here, we developed clonal phylogenetic tracing (CP-tracer) by sequential genetic barcoding, which enabled high-resolution analysis of 181,695 subclones derived from 847 individually labelled HSPCs. This approach uncovered bidirectional fate transitions between myeloid-biased (My-) and lineage-balanced haematopoietic stem cells (HSCs). Individual HSC clones, distinguished by temporally unique serial barcodes, exhibited durable lineage bidirectionality, with dynamics favouring progressive accumulation of My-HSCs over time. CRISPR-Cas9 screening identified the homeobox gene Hhex as a suppressor of myeloid differentiation that enables pivoting toward balanced output. Hhex function is age-dependent, with its expression declining in aged HSCs. Together, these findings demonstrate unexpected plasticity in HSC differentiation, modulated in part by Hhex-mediated repression, that shifts over time to drive the myeloid bias characteristic of ageing.

cell biology↗

The glutathione S-transferase Gstt1 is a robust driver of survival and dissemination in metastases

Identifying adaptive mechanisms of metastatic cancer cells remains an elusive question in the treatment of metastatic disease, particularly in pancreatic cancer (PDA), where the majority of patients present with metastatic lesions at the time of diagnosis. A loss-of-function shRNA targeted screen in metastatic-derived cells identified Gstt1, a member of the glutathione S-transferase superfamily, as uniquely required for metastasis and dissemination however dispensable for primary tumor growth. Gstt1 is expressed in early disseminated tumor cells (DTCs), is retained within a subpopulation of slow-cycling cells within established metastases and its inhibition led to a regression of macrometastatic lesions. This distinct Gstt1high population is highly metastatic and retains slow-cycling phenotypes, EMT features, and DTC characteristics compared to the Gstt1low population. Mechanistic studies indicate that in this subset of cells, Gstt1 maintains metastases by binding to and modifying intracellular fibronectin, regulating Fibronectin secretion from cancer cells and deposition into the metastatic microenvironment. We identified Gstt1 as a novel mediator of metastasis, highlighting the importance of metastatic heterogeneity and its influence on the metastatic tumor microenvironment.

cancer biology↗

Human enteric viruses shape disease phenotype through divergent innate immunomodulation

Altered enteric microorganisms in concert with host genetics shape inflammatory bowel disease (IBD) phenotypes. However, insight is limited to bacteria and fungi. We found virus like particles (VLPs) enriched from normal human colon resections, containing eukaryotic viruses and bacteriophages (collectively, the virome), actively elicited atypical anti-inflammatory innate immune programs. Conversely, IBD patient VLPs provoked inflammation, which was successfully dampened by healthy VLPs. The IBD colon tissue virome was perturbed, including enriched Picornovirus Enterovirus B, not previously observed in fecal virome studies. Mice with humanized healthy colon tissue viromes had attenuated intestinal inflammation while those with IBD-derived viromes exhibited exacerbated inflammation in a nucleic acid sensing-dependent fashion. Furthermore, there were detrimental consequences for IBD-associated MDA5 loss-of-function on patient intestinal epithelial cells exposed to healthy or IBD viromes. Our results demonstrate that innate recognition of either healthy or IBD human viromes autonomously influences disease phenotypes in IBD. Harnessing the virome may offer therapeutic and biomarker potential. One Sentence SummaryHuman viromes divergently shape host immunity and disease

immunology↗

Identification of topoisomerase as a precision-medicine target in chromatin reader SP140-driven Crohns disease

How mis-regulated chromatin directly impacts human immunological disease is poorly understood. Speckled Protein 140 (SP140) is an immune-restricted PHD and bromodomain-containing chromatin reader whose loss-of-function associates with Crohns disease (CD), multiple sclerosis (MS) and chronic lymphocytic leukemia (CLL). However, mechanisms underlying SP140-driven pathogenicity and therapeutic approaches that rescue SP140 remain unexplored. Using a global proteomic strategy, we identified SP140 as a repressor of topoisomerases (TOP) that maintains heterochromatin and immune cell fate. In humans and mice, SP140 loss resulted in unleashed TOP activity, genome instability, severely compromised lineage-defining and microbe-inducible innate transcriptional programs and defective bacterial killing. Pharmacological inhibition of TOP1 or TOP2 rescued these defects. Furthermore, exacerbated colitis was restored with TOP1 or TOP2 inhibitors in Sp140-/- mice, but not wild-type mice, in vivo. Collectively, we identify SP140 as a repressor of topoisomerases and reveal repurposing of TOP inhibition as a precision strategy for reversing SP140-driven immune disease.

immunology↗