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Biomedical subjects

Chen Liu

Publications and source records attributed to Chen Liu.

6 recordsLinked to original sources
PubMed2026

TMEM176B is co-expressed with TMEM176A and upregulated in peripheral blood monocytes of patients with primary Sjögren's syndrome.

OBJECTIVES: This study aims to determine the role of acid‑sensitive nonspecific cation channels transmembrane protein 176A (TMEM176A) and TMEM176B in autoimmune diseases, with a focus on primary Sjögren's Syndrome (pSS). METHODS: We examined the expression patterns of TMEM176A and TMEM176B across tissues and cells utilizing bulk RNA-seq and scRNA-seq datasets. Immunophenotyping analysis was performed by flow cytometry to compare CD62L expression between TMEM176B⁺ and TMEM176B⁻ monocytes. The proportion of TMEM176B+ cells in monocytes was interrogated in both pSS patients and healthy controls. Clinical correlations of TMEM176B with anti‑SSB antibody and complement C4 levels were also evaluated. RESULTS: TMEM176A and TMEM176B showed conserved co‑expression and were significantly upregulated in autoimmune diseases. TMEM176B⁺ monocytes displayed higher CD62L positivity rate than TMEM176B- monocytes. In pSS patients, the proportion of TMEM176B⁺ monocytes was elevated in total monocytes, classical monocytes (cMo) and intermediate monocytes (iMo). The proportion of TMEM176B+ monocytes positively correlated with anti‑SSB levels, while several TMEM176B-associated monocyte subset markers inversely correlated with C4. CONCLUSION: TMEM176A and TMEM176B are highly correlated. TMEM176B expression in monocytes is linked to pSS and may serve as a novel auxiliary diagnostic biomarker.

Humans↗
PubMed2026

FMRP promotes gastric cancer progression via m6A-dependent stabilization of DVL2 and activation of the Wnt/PCP-JNK pathway.

BACKGROUND: N6-methyladenosine (m6A) modification has emerged as a critical regulator in gastric cancer progression. Fragile X messenger ribonucleoprotein 1 (FMRP), an RNA-binding protein with tumorigenic potential, remains poorly characterized in gastric cancer. METHODS: FMRP expression in gastric cancer was assessed through bioinformatic analyses and tissue microarray-based immunohistochemistry. Its biological functions were examined through loss-of-function experiments in vitro and in vivo. Mechanistic investigations, including RNA interaction, m6A site mutation, and RNA stability analyses, were performed to identify downstream targets and pathways regulated by FMRP. RESULTS: Bioinformatic analyses and tissue microarray-based immunohistochemistry showed that FMRP was significantly upregulated in gastric cancer tissues. FMRP depletion suppressed tumor growth and metastasis. Subsequently, Dishevelled segment polarity protein 2 (DVL2) was identified as a candidate downstream target of FMRP. DVL2 was also significantly upregulated in gastric cancer tissues, and its expression positively correlated with FMRP expression. Mechanistically, FMRP bound to DVL2 mRNA and enhanced its stability in an m6A-dependent manner. Among the candidate sites tested, mutation of 1271A attenuated FMRP-mediated regulation of DVL2 reporter activity, supporting the involvement of this site. Functionally, FMRP promoted activation of the noncanonical Wnt/planar cell polarity (PCP) signaling pathway and enhanced the proliferative, migratory, and invasive capacities of gastric cancer cells via DVL2. CONCLUSIONS: These results define FMRP as an oncogenic driver in gastric cancer that operates via the DVL2/Wnt/PCP axis. Targeting this pathway may provide a potential therapeutic strategy for gastric cancer.

Stomach Neoplasms↗
PubMed2026

Characterization of age-related changes in the gut microbiome and metabolome of Kunming dogs and their associations with police performance.

BACKGROUND: Gut microbiota plays a pivotal role in regulating the host's central nervous system (CNS) activity and behavior. However, its influence on the police performance of Kunming dogs and the underlying mechanisms remain largely unexplored. This study was the first to apply multi-omics technologies to investigate the dynamic variations in gut microbiota and their metabolic profiles across different ages of Kunming dogs. Furthermore, we systematically examined the associations between these microbial alterations and police performance metrics, providing a theoretical foundation for enhancing the working capabilities of Kunming dogs through targeted modulation of intestinal microecology. RESULTS: The study showed that puppies, young dogs and adult dogs had significantly better police performance than elderly dogs, with young dogs exhibiting the highest scores. Analysis of 16S rRNA sequencing demonstrated that gut microbial diversity and stability were highest during the young dog stage, gradually declining with age. Metagenomic analysis revealed that the abundance of Lactobacillus acidophilus, Lactobacillus johnsonii, Limosilactobacillus reuteri, Ligilactobacillus animalis and Muribaculum gordoncarteri were strongly correlated with police performance. The results of metagenome-assembled genomes (MAGs) indicated that the above species have functional genes involved in GABAergic and glutamatergic synapse pathways. Furthermore, metabolomic analysis showed that differential metabolites were enriched in the neuroactive ligand-receptor interaction pathway, in which GABA (γ-aminobutyric acid), histamine and tyramine metabolites were positively correlated with the above species and police performance. CONCLUSION: The species L. acidophilus, L. johnsonii, L. reuteri, L. animalis, and M. gordoncarteri, which were enriched in the gut of puppies and young Kunming dogs, may potentially influence the nervous system through the production of neurotransmitters and neuromodulators, suggesting a possible association with police performance. Video Abstract.

Animals↗
PubMed2026

Cross-kingdom genomic variation in chicken gut microbiomes: insights from China's diverse local breeds.

BACKGROUND: The gut microbiome possesses substantial genetic diversity that supports microbial adaptation, but the genomic variation patterns across its prokaryotic and viral populations remain incompletely characterized. RESULTS: Through integrated metagenomic and metatranscriptomic analysis of ten indigenous chicken breeds from China, we recovered 1527 representative prokaryotic MAGs, 37,555 representative DNA viral contigs, and 1867 representative RNA viral contigs (primarily comprising Bacillota/Bacteroidota, Uroviricota, and Lenarviricota/Pisuviricota, respectively). By integrating complementary short-read and long-read metagenomics with metatranscriptomics, we identified structural variants (SVs) and single-nucleotide variants (SNVs) in these cross-kingdom genomes. Positive SV-SNV density correlations occurred consistently across all microbial groups, indicating coordinated mutational processes. DNA viruses exhibited the highest variant prevalence (86.9% SNVs, 47.7% SVs), with temperate phages accumulating significantly more variants than virulent phages. Functionally, prokaryotic variants accumulated in carbohydrate metabolism and amino acid metabolism, while viral variants demonstrated broad metabolic hijacking. Horizontal gene transfer (HGT) was characterized by a strong virus-associated signature (69.40% of 536 events) and marked by an asymmetric pattern, with phage-to-bacteria (P-to-B) flow alone constituting 37.50% of all events. Random forest analysis revealed a strong bidirectional predictive relationship between SV and SNV densities across prokaryotic, DNA viral, and RNA viral populations, suggesting coupled genomic instability. Niche breadth emerged as a major driver of SNVs across kingdoms and was positively correlated with variant density. In prokaryotes, HGT events significantly shaped variant patterns. For viruses, genomic GC content was an important factor and consistently showed a negative correlation with SNV density in both DNA and RNA viruses. CONCLUSIONS: These findings demonstrate that coordinated mutational processes and kingdom-specific intrinsic factors drive genomic variation, with viruses serving as key genetic exchange vectors in chicken gut ecosystems. Video Abstract.

Animals↗
PubMed2024

Bacteroides ovatus alleviates dysbiotic microbiota-induced graft-versus-host disease.

Acute lower gastrointestinal GVHD (aLGI-GVHD) is a serious complication of allogeneic hematopoietic stem cell transplantation. Although the intestinal microbiota is associated with the incidence of aLGI-GVHD, how the intestinal microbiota impacts treatment responses in aLGI-GVHD has not been thoroughly studied. In a cohort of patients with aLGI-GVHD (n = 37), we found that non-response to standard therapy with corticosteroids was associated with prior treatment with carbapenem antibiotics and a disrupted fecal microbiome characterized by reduced abundances of Bacteroides ovatus. In a murine GVHD model aggravated by carbapenem antibiotics, introducing B. ovatus reduced GVHD severity and improved survival. These beneficial effects of Bacteroides ovatus were linked to its ability to metabolize dietary polysaccharides into monosaccharides, which suppressed the mucus-degrading capabilities of colonic mucus degraders such as Bacteroides thetaiotaomicron and Akkermansia muciniphila, thus reducing GVHD-related mortality. Collectively, these findings reveal the importance of microbiota in aLGI-GVHD and therapeutic potential of B. ovatus.

Graft vs Host Disease↗
PubMed2023

Bacteroides ovatus alleviates dysbiotic microbiota-induced intestinal graft-versus-host disease.

Acute gastrointestinal intestinal GVHD (aGI-GVHD) is a serious complication of allogeneic hematopoietic stem cell transplantation, and the intestinal microbiota is known to impact on its severity. However, an association between treatment response of aGI-GVHD and the intestinal microbiota has not been well-studied. In a cohort of patients with aGI-GVHD (n=37), we found that non-response to standard therapy with corticosteroids was associated with prior treatment with carbapenem antibiotics and loss of Bacteroides ovatus from the microbiome. In a mouse model of carbapenem-aggravated GVHD, introducing Bacteroides ovatus reduced severity of GVHD and improved survival. Bacteroides ovatus reduced degradation of colonic mucus by another intestinal commensal, Bacteroides thetaiotaomicron, via its ability to metabolize dietary polysaccharides into monosaccharides, which then inhibit mucus degradation by Bacteroides thetaiotaomicron and reduce GVHD-related mortality.

Bacteroides ovatus↗