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Biomedical subjects

Xiao He

Publications and source records attributed to Xiao He.

3 recordsLinked to original sources

Structural Basis for Stepwise Substrate Transport and Disease Phenotypic Heterogeneity of the Mitochondrial ADP/ATP Carrier.

The mitochondrial ADP/ATP carrier (AAC) is essential for cellular energy metabolism and responsible for exchanging ADP for ATP across the inner mitochondrial membrane. However, the precise molecular determinants of substrate binding and the mechanisms underlying the phenotypic heterogeneity of AAC-related diseases remain poorly understood. Here, we combined AlphaFold3 predictions, molecular dynamics simulations, and experimental validation to identify and characterize a previously unrecognized ADP-binding site in AAC (site S2), which is distinct from the canonical bottom site (site S1). AlphaFold3 predictions on AAC variants with disrupted site S1 consistently placed ADP at site S2, interacting with residues R188, K92, and K96, a finding that was independently corroborated by our prior MD simulations. Systematic mutagenesis and functional analysis revealed distinct roles for site S2 residues: R188 serves as the primary phosphate-specific anchor; K92 and K96 facilitate initial recruitment and stabilization; and the aromatic ladder (Y187/Y191/F192/Y195) assists the conformational transition of ADP from anti to syn, a critical step enabling downward translocation. Functional characterization demonstrated that mutations in site S2 significantly impaired ADP transport and oxidative phosphorylation. Notably, the spatial distribution of AAC disease mutations correlates with this bipartite architecture: mild PEOA2-associated mutations cluster near site S2 and perturb the local conformation without abolishing binding, whereas lethal mutations cluster near site S1 and disrupt both ADP binding and structural integrity of the m-gate. Our findings provide new mechanistic insights into stepwise substrate transport and potential therapeutic targets for AAC-related diseases.

Mitochondrial ADP, ATP Translocases

Large-Scale Plasma Proteomics Identifies Early Molecular Deviations and Improves Risk Prediction for Heart Failure Among Individuals With Obesity.

AIMS: Heart failure (HF) is a major global public health challenge, with obesity being one of its key risk factors. Although several HF risk prediction models have been developed in the general population, few are specifically tailored to individuals with obesity. This underscores the urgent need for precise biomarkers to improve individual risk stratification and enable personalized prevention strategies. We aimed to develop and validate a plasma proteomics-based protein risk score (PRS) to predict incident HF among individuals with obesity. MATERIALS AND METHODS: We analysed 9831 participants with obesity (BMI ≥ 30 kg/m2) from the UK Biobank with baseline measurements of 2911 circulating proteins and up to 16 years of follow-up. Multivariable Cox regression identified proteins associated with incident HF after comprehensive covariate adjustment. A PRS was constructed using LASSO regression and evaluated in a held-out test set. Protein trajectories before HF onset were reconstructed using LOESS modelling. To enhance clinical feasibility, a minimal protein panel was identified using LightGBM with forward feature selection. RESULTS: A total of 727 participants developed HF during follow-up. Multivariable cox analyses identified 578 proteins significantly associated with HF. LASSO regression further selected 81 proteins to build the PRS, which showed a strong association with HF risk in both training (HR 3.57; 95% CI 3.19-4.00) and test cohorts (HR 2.45; 95% CI 2.20-2.74). Adding the PRS improved prediction beyond age and sex (ΔC = 0.091) and beyond the Pooled Cohort Equations to Prevent Heart Failure (PCP-HF) model (ΔC = 0.052), with consistent gains in NRI and IDI. Proteomic deviations were detectable up to 16 years before diagnosis. A four-protein panel (GDF15, NT-proBNP, TNFRSF10B, CTHRC1) achieved robust discrimination (AUC 0.789), outperforming NT-proBNP alone (AUC 0.695) and complementing the PCP-HF model (combined AUC 0.803). DISCUSSION: Large-scale plasma proteomics substantially improves HF risk prediction in individuals with obesity and reveals long-standing molecular alterations preceding clinical onset. A simplified four-protein panel maintains robust predictive accuracy and provides a practical approach for the early detection and targeted prevention of obesity-related HF.

Humans

NAD activates olfactory receptor 1386 to regulate type I interferon responses in Plasmodium yoelii YM infection.

Olfactory receptors (Olfr) are G protein-coupled receptors that are normally expressed on olfactory sensory neurons to detect volatile chemicals or odorants. Interestingly, many Olfrs are also expressed in diverse tissues and function in cell-cell recognition, migration, and proliferation as well as immune responses and disease processes. Here, we showed that many Olfr genes were expressed in the mouse spleen, linked to Plasmodium yoelii genetic loci significantly, and/or had genome-wide patterns of LOD scores (GPLSs) similar to those of host Toll-like receptor genes. Expression of specific Olfr genes such as Olfr1386 in HEK293T cells significantly increased luciferase signals driven by IFN-β and NF-κB promoters, with elevated levels of phosphorylated TBK1, IRF3, P38, and JNK. Mice without Olfr1386 were generated using the CRISPR/Cas9 method, and the Olfr1386-/- mice showed significantly lower IFN-α/β levels and longer survival than wild-type (WT) littermates after infection with P. yoelii YM parasites. Inhibition of G protein signaling and P38 activity could affect cyclic AMP-responsive element promoter-driven luciferase signals and IFN-β mRNA levels in HEK293T cells expressing the Olfr1386 gene, respectively. Screening of malaria parasite metabolites identified nicotinamide adenine dinucleotide (NAD) as a potential ligand for Olfr1386, and NAD could stimulate IFN-β responses and phosphorylation of TBK1 and STAT1/2 in RAW264.7 cells. Additionally, parasite RNA (pRNA) could significantly increase Olfr1386 mRNA levels. This study links multiple Olfrs to host immune response pathways, identifies a candidate ligand for Olfr1386, and demonstrates the important roles of Olfr1386 in regulating type I interferon (IFN-I) responses during malaria parasite infections.

Animals