Biomedical subjects

Kexin Chen

Publications and source records attributed to Kexin Chen.

3 recordsLinked to original sources

PubMed2026

MYDGF as a telomerase activator and therapeutic target for osteoarthritis.

Osteoarthritis (OA) involves progressive cartilage breakdown. This is driven by impaired chondrocyte function and an imbalance in the extracellular matrix homeostasis. However, the key upstream regulators that maintain healthy chondrocytes are still not fully known. Here, we report that myeloid-derived growth factor (MYDGF) is a novel regulator of telomerase activity and is critical for cartilage health. Using a genome-wide CRISPR-Cas9 screen with a TERT reporter system, MYDGF was identified as a strong positive regulator of telomerase. Functional studies confirmed that MYDGF positively regulates TERT expression and telomerase activity in both HeLa and ATDC5 cells. In a mouse surgical destabilization of the medial meniscus (DMM) OA model, MYDGF knockout (KO) mice exhibited more severe cartilage damage. Conversely, delivering MYDGF into the knee joint using AAV virus partially alleviated cartilage injury. Transcriptome profiling revealed that MYDGF-deficient chondrocytes exhibit downregulated key pathways involved in matrix building and upregulated inflammatory signals, indicating a shift in cell state. In summary, our work establishes MYDGF as a key upstream factor for both telomerase and cartilage matrix homeostasis remodeling. It connects telomerase function to chondrocyte health. These findings also highlight MYDGF as a promising new target for treating osteoarthritis.

Cartilage degeneration↗

PubMed2025

Endogenous fine-mapping and prioritization of functional regulatory elements in complex genetic loci.

Most genetic loci linked to polygenic traits are in non-coding regions, with complex regulation and linkage disequilibrium (LD), complicating causal variant and gene prioritization. We used multiplexed single-cell CRISPR interference and activation perturbations to investigate cis-regulatory element (CRE) and gene expression relationships within tight LD in the endogenous chromatin context. We demonstrated the prevalence of multiple causality in perfect LD (pLD) for independent expression quantitative trait loci (eQTLs) and uncovered fine-grained genetic effects on gene expression within pLD, which are difficult to decipher using traditional eQTL fine-mapping or existing computational methods. We found that over one-third of the causal CREs lack classical epigenetic markers prior to perturbation, and we functionally validated one of these hidden regulatory mechanisms. Leveraging Multiome single-cell epigenetic and sequence perturbations, we highlighted the regulatory plasticity of the human genome. Our study will guide the exploration of missing causal mechanisms underlying molecular trait regulation and disease development.

Humans↗

PubMed2025

Stratifying Lung Adenocarcinoma Risk with Multi-ancestry Polygenic Risk Scores in East Asian Never-Smokers.

BACKGROUND: Lung adenocarcinoma (LUAD) in never-smokers is a major public health burden, especially among East Asian women. Polygenic risk scores (PRSs) are promising for risk stratification but are primarily developed in European-ancestry populations. We aimed to develop and validate single- and multi-ancestry PRSs for East Asian never-smokers to improve LUAD risk prediction. METHODS: PRSs were developed using genome-wide association study summary statistics from East Asian (8,002 cases; 20,782 controls) and European (2,058 cases; 5,575 controls) populations. Single-ancestry models included PRS-25, PRS-CT, and LDpred2; multi-ancestry models included LDpred2+PRS-EUR128, PRS-CSx, and CT-SLEB. Performance was evaluated in independent East Asian data from the Female Lung Cancer Consortium (FLCCA) and externally validated in the Nanjing Lung Cancer Cohort (NJLCC). We assessed predictive accuracy via AUC, with 10-year and (age 30-80) absolute risks estimates. RESULTS: The best multi-ancestry PRS, using East Asian and European data via CT-SLEB (clumping and thresholding, super learning, empirical Bayes), outperformed the best East Asian-only PRS (LDpred2; AUC=0.629, 95% CI:0.618,0.641), achieving an AUC of 0.640 (95% CI:0.629,0.653) and odds ratio of 1.71 (95% CI:1.61,1.82) per SD increase. NJLCC Validation confirmed robust performance (AUC =0.649, 95% CI: 0.623, 0.676). The top 20% PRS group had a 3.92-fold higher LUAD risk than the bottom 20%. Further, the top 5% PRS group reached a 6.69% lifetime absolute risk. Notably, this group reached the average population 10-year LUAD risk at age 50 (0.42%) by age 41, nine years earlier. CONCLUSIONS: Multi-ancestry PRS approaches enhance LUAD risk stratification in East Asian never-smokers, with consistent external validation, suggesting future clinical utility.

East Asian never smokers↗