Biomedical subjects

Zhaoli Sun

Publications and source records attributed to Zhaoli Sun.

4 recordsLinked to original sources

PubMed2026

Proteomic Identification of Pig Xenoantigens for Clinical Xenotransplantation.

Xenotransplantation using genetically engineered pig organs offers a promising solution to the shortage of donor organs for life-saving transplantations. However, human-preformed antibodies against unknown pig xenoantigens remain a significant barrier to successful xenotransplantation. Current methods for characterizing these antibodies or xenoantigens are limited to cellular-level cross-match assays. In this study, we developed a novel approach to identify pig xenoantigens, including peptide and glycopeptide epitopes, that react with human-preformed antibodies. First, human-preformed antibodies against xenoantigens were enriched from plasma using immobilized pig kidney proteins. The enriched antibodies were then immobilized and used to isolate pig kidney proteins, peptides, and intact glycopeptides, followed by liquid chromatography-tandem mass spectrometry analysis. This dual-level approach identified 221 peptides corresponding to 153 proteins, with a significant enrichment of plasma membrane and extracellular proteins. Notably, 11 peptides were unique to pig sequences, suggesting their potential role in driving xenogeneic immune responses. Glycoproteomic analysis identified 122 intact glycopeptides, predominantly complex/hybrid glycoforms, and Neu5Gc-containing glycans. Our method effectively identifies peptides and intact glycopeptides reactive to human-preformed antibodies, providing critical insights for discovering xenoantigens. These findings could guide genetic engineering strategies and enhance recipient candidate screening for xenotransplantation, ultimately increasing the feasibility and success of xenogeneic organ transplantation.

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PubMed2026

Spatiotemporal transcriptomic analysis during cold ischemic injury to the murine kidney reveals compartment-specific changes.

BACKGROUND: Kidney transplantation is the preferred treatment strategy for end-stage kidney disease. Deceased donor kidneys usually undergo cold storage until kidney transplantation, leading to cold ischemia injury that may contribute to poor graft outcomes. However, the molecular characterization of potential mechanisms of cold ischemia injury remains incomplete. RESULTS: To bridge this knowledge gap, we leverage 10x Visium spatial transcriptomic technology to perform full transcriptome profiling of murine kidneys subject to varying durations of cold ischemia typical in a deceased donor kidney transplant setting. We develop a computational workflow to identify and compare spatiotemporal transcriptomic changes that accompany the injury pathophysiology in a tissue compartment-specific manner. We identify proportional enrichment of oxidative phosphorylation (OXPHOS) genes with increasing duration of cold ischemia injury within the oxygen-lean inner medulla region, suggestive of atypical metabolic presentation. This is distinct in cold ischemia injury tissue compared to warm ischemia-reperfusion kidney injury tissue. Spatiotemporal trends are validated by qPCR and immunofluorescence in a larger cohort of mice. CONCLUSIONS: Altogether, our spatiotemporal transcriptomic analysis identifies coordinated molecular changes within metabolic pathways such as OXPHOS deep within the cold ischemic kidney, highlighting the need for increased attention to the inner medulla and potential opportunities for new insights beyond those available from superficial biopsy-focused tissue examination.

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PubMed2026

Genetic regulation of AIF1 shapes immune and liver injury profiles in chronic alcohol use.

BACKGROUNDIn chronic alcohol consumers, immune cells may drive the progression from mild liver injury to more severe alcohol-associated liver disease (ALD), including alcohol-associated hepatitis (AAH) and cancer. Liver macrophages, both resident and infiltrating, express allograft inflammatory factor 1 (AIF1), which is upregulated during inflammation and enhances immune activation.METHODSUsing serum and urine samples from 868 individuals classified as having alcohol use disorder or not, based on DSM-IV/V criteria, along with serum and liver biopsy tissue from a second cohort of 27 patients diagnosed with AAH, we evaluated the impact of the AIF1 promoter single-nucleotide polymorphism (SNP) (rs3132451; C/C, C/G, G/G) on liver function markers and immune cell profiles.RESULTSAIF1 transcript levels were genotype dependent: C/C homozygotes expressed 5.2% of the levels observed in G/G individuals, while C/G heterozygotes expressed 46%. Unlike most SNPs associated with harmful effects, the G/G genotype is highly prevalent, present in about 70% of patients. Among chronic alcohol users, G/G individuals exhibited elevated markers of liver injury and a more than 3-fold increase in hepatic immune cells, including infiltrating AIF1+ macrophages and neutrophils. Despite similar durations of alcohol misuse, G/G individuals had higher Model for End-Stage Liver Disease scores compared with C/G individuals, indicating a significantly greater 90-day mortality risk. Notably, some immune abnormalities, such as elevated neutrophils, persisted in G/G males even after alcohol abstinence.CONCLUSIONThese findings suggest that functional genetic variation in AIF1 may contribute to the severity and persistence of ALD.TRIAL REGISTRATIONClinicalTrials.gov NCT02231840.FUNDINGResearch support was provided from the National Institute on Alcohol Abuse and Alcoholism of the NIH under grants 1ZIAAA000440-02 and R24AA025017.

Humans↗

PubMed2025

Silencing FAF2 mitigates alcohol-induced hepatic steatosis by modulating lipolysis and PCSK9 pathway.

BACKGROUND: Chronic alcohol consumption leads to lipid accumulation, oxidative stress, cellular damage, and inflammation in the liver, collectively referred to as alcohol-associated liver disease (ALD). FAF2/UBXD8/ETEA (Fas-associated factor 2) is a ubiquitin ligase adaptor protein that plays a crucial role in the ubiquitin-mediated degradation of misfolded proteins in the endoplasmic reticulum. A recent genome-wide association study indicated an association between FAF2 and ALD; however, the exact contribution of FAF2 to ALD pathogenesis remains unclear. METHODS: FAF2 was knocked down using AAV-delivered shRNA in C57/BL6 mice. Mice were subjected to a chronic-plus-single binge ethanol feeding (NIAAA) model. Nine hours after gavage, liver, blood, and other organs of interest were collected for gene expression and biochemical analyses. RESULTS: We first observed a significant elevation in hepatic FAF2 protein expression in individuals with ALD and in mice subjected to an ethanol-binge model. Interestingly, knocking down FAF2 in the liver using adeno-associated virus serotype 8-delivered short hairpin RNA conferred a protective effect against alcohol-induced liver steatosis in ethanol-binged mice. Transcriptomic analysis revealed that differentially expressed genes were enriched in multiple lipid metabolism regulation pathways. Further analysis of transcription factors regulating these differentially expressed genes suggested potential regulation by SREBP1. Several SREBP1 target genes, including Fasn, Scd1, Lpin1, and Pcsk9 (proprotein convertase subtilisin/kexin type 9), were dysregulated in the livers of ethanol-fed FAF2 knockdown mice. Additionally, Pcsk9 could be regulated through the FOXO3-SIRT6 pathway in the livers of ethanol-fed FAF2 knockdown mice, leading to increased liver low-density lipoprotein receptor expression and reduced plasma LDL cholesterol levels. Furthermore, FAF2 knockdown in mouse liver enhanced adipose triglyceride lipase lipolytic activity by upregulating the adipose triglyceride lipase activator, comparative gene identification-58, and downregulating the adipose triglyceridelipase transport inhibitor, Elmod2, contributing to the alleviation of liver steatosis. CONCLUSIONS: Our study uncovers a novel mechanism involving FAF2 in the pathogenesis of ALD.

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