Biomedical subjects

Kun Liu

Publications and source records attributed to Kun Liu.

4 recordsLinked to original sources

PubMed2026

Multilevel genomic, transcriptomic, and epidemiologic evidence linking diabetic retinopathy to Alzheimer disease.

BACKGROUND: Diabetic retinopathy (DR) and Alzheimer disease (AD) share metabolic and vascular dysfunctions, but the extent to which they reflect overlapping genetic susceptibility and neurovascular-metabolic regulatory pathways remains unclear. We combined multi-omics analyses with population-based data to examine the genetic convergence, cellular pathways, and longitudinal association between DR and AD. METHODS: We performed a two-sample Mendelian randomisation (MR) to estimate the association between genetically predicted DR liability and AD risk. We used Bayesian colocalisation analysis to identify shared genomic loci, and summary-data-based MR (SMR) to detect expression-mediated genes jointly associated with DR and AD. We analysed single-cell RNA sequencing data to characterise shared cellular features and related biological pathways. We also conducted an MR-based mediation analysis to explore whether lipid-related, metabolic, or inflammatory traits mediated the observed DR-AD association, and a longitudinal analysis of the UK Biobank cohort to assess the association between DR and incident AD. RESULTS: With the MR analysis, we found that genetically predicted liability to DR was associated with a modest increase in AD risk. Colocalisation analysis supported a shared genetic signal. We identified three genes with shared expression-mediated associations across DR and AD through SMR. Functional enrichment analyses revealed partially overlapping neurovascular and metabolic pathways. Using MR-based mediation analysis, we found no significant intermediary traits linking DR and AD. Findings from the UK Biobank cohort were directionally consistent with the genetic analyses. CONCLUSIONS: Genetic liability to DR is associated with an increased risk of AD and is accompanied by shared expression-mediated effects and convergent neurovascular-metabolic pathways. These findings support the possibility that DR may serve as a clinically accessible indicator of increased neurodegenerative vulnerability.

Humans↗

PubMed2026

The clinical value of adding immune checkpoint inhibitors to radiotherapy for cancer: a systematic review and meta-analysis.

BACKGROUND: While several randomized clinical trials (RCTs) have explored the addition of immune checkpoint inhibitor (ICI) treatment for patients undergoing radiotherapy, studies systematically assessing the clinical value of such interventions are lacking. METHODS: PubMed, Embase, and Cochrane Library databases were searched for relevant RCTs of cancers that received ICIs plus radiotherapy or radiotherapy. Eligible studies were those published in English as of 14 April 2024. Two independent reviewers screened the included studies and extracted relevant data, then selected the random or fixed-effects model based on the I2 statistic. The main outcomes were hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) and progression-free survival (PFS); Odds ratios (ORs) with 95% CIs for objective response rate (ORR), disease control rate (DCR), and adverse events (AEs). Stratified analysis was performed based on cancer type, ICI type, and the timing of ICI addition. The study was registered on PROSPERO (CRD42024551008). RESULTS: 15 RCTs with 7947 patients were included. Pooled HRs were 0.865 (95% CI, 0.730-1.000; I2 = 72.1%) for OS and 0.799 (0.677-0.922; I2 = 82.0%) for PFS in cancer patients. In cancer types, adding immunotherapy to radiotherapy significantly improved patients with non-small-cell lung cancer (OS: 0.544 [0.371-0.717]; PFS: 0.527 [0.438-0.617]) and cervical cancer (OS: 0.722 [0.578-0.867] and PFS: 0.754 [95%CI, 0.621-0.887]). Regarding the ICIs schedule, adjuvant ICI therapy with pooled HRs was 0.742 (0.649-0.834) for OS and 0.638 (0.579-0.697) for PFS. In addition, the pooled ORs for the incidence of grade 3 or higher treatment-related and immune-related adverse events were 1.227 (1.059-1.421; I2 = 71.9%) and 2.217 (1.743-2.821; I2 = 74.0%), respectively. CONCLUSION: Adding immunotherapy to radiotherapy can provide significant clinical benefits for patients with NSCLC and cervical cancer, and the addition of these ICIs in the adjuvant stage is supported.

Humans↗

PubMed2026

Reprogrammed Komagataella phaffii for enhanced secretory expression of human lactoferrin.

Human lactoferrin (hLF) is a multifunctional glycoprotein of the transferrin family derived from milk and mucosal secretions, which exhibits antibacterial, anti-tumor, and immunomodulatory functions, and is an important component of infant formula. Conventional methods for lactoferrin expression are often inefficient, primarily due to inadequate protein synthesis capabilities and poor stability within microbial hosts. Herein, a Komagataella phaffii yeast strain capable of high-level secretory expression of hLF was constructed by reprogramming the endoplasmic reticulum (ER) and vacuole using CRISPR/Cas9 technology. A dual-expression cassette containing the AOX1 promoter, an α-secretion signal peptide, the hLF gene, and a terminator was integrated into three different sites of the K. phaffii genome. The stepwise strategy combining expansion of the ER membrane involved in protein synthesis with knockout of vacuolar proteases further enhanced hLF production. Subsequently, 0.1 g/L FeCl₃ was added to the medium to reduce the toxicity of hLF and improve its stability. After high-density cultivation of K. phaffii through optimization of cultivation conditions in shake flasks and a 5 L bioreactor, the secretory intact hLF titer reached 2214 mg/L, representing a 76.3-fold increase achieved through these engineering strategies. In addition, antibacterial experiments demonstrated that this secretory hLF had a significant inhibitory effect on Escherichia coli, Staphylococcus aureus, and yeast. Overall, the developed K. phaffii protein expression platform enabled efficient production of lactoferrin, demonstrating its potential for expressing other lactoproteins.

Lactoferrin↗

PubMed2026

Widespread Molecular Imprints in the Serum Proteome of COVID-19 Convalescents Uncovering Immune System Sequelae.

Post-COVID-19 sequelae have become an emerging global health issue, but the mechanisms for the sustained susceptibility of convalescents to the sequelae remain poorly understood. Here we report the use of a restricted open-search approach to explore the molecular imprints of SARS-CoV-2 infection left on the proteome of 412 COVID-19 patients and convalescences. A total of 827 non-standard amino acid variations, chemically modified residues as well as post-translational modifications, termed non-coded amino acids (ncAAs), are found spreading over 29,814 sites in patient's serum proteins. Markedly, widespread ncAAs are induced and sustainedly imprinted on the serum proteome predominately perturbing the immunoglobulin-mediated immune response, complement activation and coagulation regulation even 12 months after recovery. Sustained amino acid variations and chemical modifications are found in the complementary‑determining regions (CDRs) of the variable region of immunoglobulin contributing to the interactions between the emerging antibody and antigens; durable chemical amino acid modifications found in the hyper ncAA-modified regions of the constant region of immunoglobulin important for the interaction with the complement and regulatory receptors. In the complement system, inducible ncAAs are memorized in the components essential for the complement activation, amplification cascades and membrane attack processes. Thus, the workflow described in this study can be used to identify the molecular imprints of viral infection at the proteomic scale, particularly the specific antibodies and the immune targets left in COVID-19 patients and convalescents.

Humans↗