Biomedical subjects

Lijun Liu

Publications and source records attributed to Lijun Liu.

3 recordsLinked to original sources

PubMed2026

Functional characterization of lncIMF_17214 in regulating intramuscular fat deposition of yellow-feathered broilers.

Intramuscular fat (IMF) content and lipid composition are key determinants of both the nutritional value and sensory attributes of poultry meat, yet the underlying regulatory mechanisms remain insufficiently elucidated. In this study, triglyceride (TG) content was employed as a quantitative phenotypic proxy to dissect the molecular basis of IMF deposition in yellow-feathered broilers. By integrating TG phenotypic data from 315 individuals with transcriptomic profiles and whole-genome resequencing datasets, a TG-associated long noncoding RNA (lncRNA), lncIMF_17214, was identified. Functional characterization revealed that lncIMF_17214 functions as a negative regulator of lipid deposition. Specifically, its knockdown led to significant increases in TG and total cholesterol concentrations, promoted lipid droplet accumulation, and decreased shear force in breast muscle, whereas its overexpression elicited the opposite effects. Mechanistically, lncIMF_17214 interacts with the RNA-binding protein CNBP, forming a regulatory complex that inhibits lipid accumulation. Furthermore, liver-directed overexpression increased the abundance of lncIMF_17214 in plasma exosomes, while liver-directed manipulation was associated with changes in hepatic and breast-muscle lipid deposition; direct exosome-mediated transfer to intramuscular adipocytes remains to be established. Transcriptomic profiling coupled with pathway enrichment analyses demonstrated that lncIMF_17214 predominantly influences steroid biosynthesis, unsaturated fatty acid metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. This suggests that it may be involved in the regulation of these pathways, although the underlying molecular mechanisms remain to be further elucidated. Collectively, these findings define a lncIMF_17214-centered regulatory axis linking intracellular and systemic lipid metabolism and provide a robust molecular framework for the targeted improvement of meat quality traits in yellow-feathered broilers.

Breast muscle↗

PubMed2026

Prenatal diagnosis and genetic counseling of a de novo 10q11.22q11.23 duplication associated with a normal development at 12 months of age.

BACKGROUND: Copy number variants are an important source of genomic variations, ranging from pathogenic to benign. The 10q11.22q11.23 region contains complex low-copy repeats that predispose to recurrent deletions and duplications via nonallelic homologous recombination. While some reports associate duplications of this region with developmental delay, intellectual disability, and autism spectrum disorders, emerging evidence suggests that such duplications may also be observed in phenotypically normal individuals, indicating incomplete penetrance and variable expressivity. CASE PRESENTATION: A 35-year-old pregnant woman with an unremarkable obstetric history underwent amniocentesis at 20 weeks of gestation. Conventional karyotyping and copy number variation sequencing (CNV-seq) were performed. CNV-seq revealed a de novo 4.56 Mb duplication at 10q11.22q11.23. The duplication was classified as a variant of uncertain significance. After extensive genetic counseling, the parents elected to continue the pregnancy. At 40 weeks of gestation, a female infant was delivered by cesarean section with normal birth parameters. A comprehensive physical examination at birth revealed no abnormalities. At the 12-month follow-up, the infant demonstrated normal growth parameters and age-appropriate neurodevelopmental milestones, with no evidence of dysmorphic features, developmental delay, or other clinical concerns. CONCLUSION: This report describes a prenatal case of a de novo 10q11.22q11.23 duplication with a normal development at 12 months of age. Our findings contribute to the growing body of literature suggesting that duplications in this pericentromeric region may exhibit incomplete penetrance and variable expressivity, and in some cases, may represent benign familial or de novo variants without apparent clinical consequences.

10q11.22q11.23 duplication↗

PubMed2025

Active- and Allosteric-Site Cyclic Peptide Inhibitors of Secreted M. tuberculosis Chorismate Mutase.

The secreted Chorismate mutase enzyme of Mycobacterium tuberculosis (*MtbCM) is an underexplored potential target for the development of new antitubercular agents that are increasingly needed as antibiotic resistance rises in prevalence. As an enzyme suspected to be involved in virulence and host-pathogen interactions, disruption of its function could circumvent the difficulty of treating tuberculosis-infected granulomas. Drug development, however, is limited by novel ligand discovery. Currently, *MtbCM activity is measured by using a low throughput acid/base-mediated product derivatization absorbance assay. Here, we utilized an RNA-display affinity selection approach enabled by the Random Peptides Integrated Discovery (RaPID) system to screen a vast library of macrocyclic peptides (MCP) for novel *MtbCM ligands. Peptides identified from the RaPID selection, and analogs thereof identified by analyzing the selection population dynamics, produced a new class of *MtbCM inhibiting MCPs. Among these were two noteworthy "chorismides", whose binding modes were elucidated by X-ray crystallography. Both were potent inhibitors of the CM enzyme activity. One was identified as an allosteric binding peptide revealing a novel inhibition approach, while the other is an active-site binding peptide that when conjugated to a fluorescent probe allowed for the development of a series of alternative fluorescence-based ligand-displacement assays that can be utilized for the assessment of potential *MtbCM inhibitors.

Mycobacterium tuberculosis↗