Biology subjects

Liao, H.-C.

Publications and source records attributed to Liao, H.-C..

5 recordsLinked to original sources

bioRxiv2026

Aging-Associated Decline in Macrophage STAT6-OXPHOS Programs Promotes Tumor-Like Multinucleated Syncytia

Aging can alter macrophage functions through changes in intracellular processing, mitochondrial activity, and chronic inflammatory activation; however, whether aging-associated macrophage deregulation contributes to tumor-associated multinucleated syncytial formation remains poorly understood. Here, we investigated the role of aging macrophages in promoting tumor-like multinucleated syncytia and explored the underlying metabolic mechanisms. Immunohistochemical analyses of metastatic tissue sections from patients with prostate, breast, and lung cancers demonstrated enrichment of CD68+/panCK+ multinucleated tumor-like osteoclast syncytia in elderly patients. Using ex vivo co-culture systems, aged bone marrow-derived macrophages exhibited significantly increased propensity to generate multinucleated syncytia containing proliferative Ki67-positive cancer-associated nuclei. These syncytia displayed attenuated mitochondrial oxidative phosphorylation (OXPHOS) programs characterized by reduced oxygen consumption rates and decreased expression of mitochondrial respiratory proteins, such as ATP5a and SDHB. Pharmacologic inhibition of STAT6 further enhanced syncytial formation and suppressed OXPHOS-associated programs, whereas treatment with the EP2 antagonist C52 partially restored mitochondrial gene expression and reduced syncytial formation. Together, these findings identify a previously unrecognized aging-associated mechanism linking macrophage deregulation, attenuated STAT6-associated mitochondrial programs, and tumor-like multinucleated syncytial formation.

cancer biology↗

bioRxiv2025

Identifying the Minimal Number of Protein Markers for Cell Type Annotation Using MiniMarS

Over the past decade, there has been an explosion in the characterisation and discovery of cell populations using single-cell technologies. Single-cell multi-omics data, particularly those incorporating gene and protein expression, are increasingly commonplace and can lead to more refined characterisation of cell types. A common challenge for biologists is to isolate cells of interest using a minimal number of markers for cytometry experiments. Although several methods exist for marker selection, there is limited guidance on the relative performance of these methods, and a wrapper package that combines multiple methods is lacking. The method that performs best can vary depending on the dataset and it can be challenging for researchers to test multiple methods for a given dataset. To address these issues, we present MiniMarS (Minimal Marker Selection), an R package that serves as a wrapper for 10 different algorithms. It allows users to determine the best-performing algorithm for identifying the optimal number of markers that will delineate cell populations in their dataset. MiniMarS uses pre-annotated cells with protein features from CyTOF or sequencing-based assays such as CITE-seq and Abseq as input. Outputs include 1) the minimum number of protein markers required to identify the annotated cell populations using a range of marker selection algorithms, and 2) a range of metrics to evaluate the performance of each algorithm. MiniMarS effectively differentiated populations across various datasets, including those from human blood, bone marrow, thymus, mouse spleen, and lymph nodes, even after subsampling over 41,000 cells to 2,500 cells. MiniMarS also identified 15 markers from CITE-seq data, which were then used to successfully identify the same 11 cell subsets in a CyTOF dataset (F1 score>0.9). Additionally, we showed that by appropriately combining clusters, MiniMarS improves the F1 score of a rare population identification (<1% of total cells) by 28.7%. Together, these findings highlight the broad applicability of MiniMarS in identifying appropriate markers for distinguishing cell populations.

bioinformatics↗

bioRxiv2024

MAssively-Parallel Flow cytometry Xplorer (MAPFX): A Toolbox for Analysing Data from the Massively-Parallel Cytometry Experiments

Massively-Parallel Cytometry (MPC) experiments allow cost-effective quantification of more than 200 surface proteins at single-cell resolution. The Infinity Flow (Inflow) analysis protocol was developed to measure highly informative protein backbone markers on all cells in all wells distributed across three 96-well plates, along with well-specific exploratory protein infinity markers. Backbone markers can be used to impute the infinity markers on cells in all other wells using machine learning methods. This protocol offers unprecedented opportunities for more comprehensive classification of cell types. However, some aspects of the protocol can be improved, including methods for background correction and removal of unwanted variation. Here, we propose MAPFX as an end-to-end toolbox that carefully pre-processes the raw data from MPC experiments, and further imputes the missing infinity markers in the wells without those measurements. Our pipeline starts by performing background correction on raw intensities to remove the noise from electronic baseline restoration and fluorescence compensation by adapting a normal-exponential convolution model. Unwanted technical variation, from sources such as well effects, is then removed using a log-normal model with plate, column, and row factors, after which infinity markers are imputed using the informative backbone markers as predictors. The completed dataset can then be used for clustering and other statistical analyses. Unique features of our approach include performing background correction prior to imputation and removing unwanted variation from the data at the cell-level, while explicitly accounting for the potential association between biology and unwanted factors. We benchmark our pipeline against alternative pipelines and demonstrate that our approach is better at preserving biological signals, removing unwanted variation, and imputing unmeasured infinity markers.

bioinformatics↗

bioRxiv2022

Subtyping of major SARS-CoV-2 variants reveals different transmission dynamics

SARS-CoV-2 continues to evolve, causing waves of the pandemic. Up to March 2022, eight million genome sequences have accumulated, which are classified into five major variants of concern. With the growing number of sequenced genomes, analysis of the big dataset has become increasingly challenging. Here we developed systematic approaches for comprehensive subtyping and pattern recognition for transmission dynamics. By analyzing the first two million viral genomes as of July 2021, we found that different subtypes of the same variant exhibited distinct temporal trajectories. For example, some Delta subtypes did not spread rapidly, while others did. We identified sets of characteristic single nucleotide variations (SNVs) that appeared to enhance transmission or decrease efficacy of antibodies for some subtypes of the Delta and Alpha variants. We also identified a set of SNVs that appeared to suppress transmission or increase viral sensitivity to antibodies. These findings are later confirmed in an analysis of six million genomes as of December 2021. For the Omicron variant, the dominant type in the world, we identified the subtypes with enhanced and suppressed transmission in an analysis of seven million genomes as of January 2022 and further confirmed the findings in a later analysis of eight million genomes as of March 2022. While the "enhancer" SNVs exhibited an enriched presence on the spike protein, the "suppressor" SNVs are mainly elsewhere. Disruption of the SNV correlation largely destroyed the enhancer-suppressor phenomena. These results suggest the importance of fine subtyping of variants, and point to potential complex interactions among SNVs.

bioinformatics↗

bioRxiv2020

Genomic, geographic and temporal distributions of SARS-CoV-2 mutations

The COVID-19 pandemic is the most significant public health issue in recent history. Its causal agent, SARS-CoV-2, has evolved rapidly since its first emergence in December 2019. Mutations in the viral genome have critical impacts on the adaptation of viral strains to the local environment, and may alter the characteristics of viral transmission, disease manifestation, and the efficacy of treatment and vaccination. Using the complete sequences of 1,932 SARS-CoV-2 genomes, we examined the genomic, geographic and temporal distributions of aged, new, and frequent mutations of SARS-CoV-2, and identified six phylogenetic clusters of the strains, which also exhibit a geographic preference in different continents. Mutations in the form of single nucleotide variations (SNVs) provide a direct interpretation for the six phylogenetic clusters. Linkage disequilibrium, haplotype structure, evolutionary process, global distribution of mutations unveiled a sketch of the mutational history. Additionally, we found a positive correlation between the average mutation count and case fatality, and this correlation had strengthened with time, suggesting an important role of SNVs on disease outcomes. This study suggests that SNVs may become an important consideration in virus detection, clinical treatment, drug design, and vaccine development to avoid target shifting, and that continued isolation and sequencing is a crucial component in the fight against this pandemic. Significance StatementMutation is the driving force of evolution for viruses like SARS-CoV-2, the causal agent of COVID-19. In this study, we discovered that the genome of SARS-CoV-2 is changing rapidly from the originally isolated form. These mutations have been spreading around the world and caused more than 2.5 million of infected cases and 170 thousands of deaths. We found that fourteen frequent mutations identified in this study can characterize the six main clusters of SARS-CoV-2 strains. In addition, we found the mutation burden is positively correlated with the fatality of COVID-19 patients. Understanding mutations in the SARS-CoV-2 genome will provide useful insight for the design of treatment and vaccination.

microbiology↗