Single-cell transcriptome analysis revealed the heterogeneity and microenvironment of gastrointestinal stromal tumors.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the human gastrointestinal tract. In this study, we performed single-cell RNA sequencing (RNA-seq) on intra- and peri-tumor tissues from GIST patients with the aim of discovering the heterogeneity of tumor cells in GIST and their interactions with other cells. We found four predominating cell types in GIST tumor tissue, including T cells, macrophages, tumor cells, and NK cells. Tumor cells could be clustered into two groups: one was highly proliferating and associated with high risk of metastasis, the other seemed "resting" and associated with low risk. Their clinical relevance and prognostic values were confirmed by RNA-seq of 65 GIST samples. T cells were the largest cell type in our single-cell data. Two groups of CD8+ effector memory (EM) cells were in the highest clonal expansion and performed the highest cytotoxicity but were also the most exhausted among all T cells. A group of macrophages were found polarized to possess both M1 and M2 signatures, and increased along with tumor progression. Cell-to-cell interaction analysis revealed that adipose endothelial cells had high interactions with tumor cells to facilitate their progression. Macrophages were at the center of the tumor microenvironment, recruiting immune cells to the tumor site and having most interactions with both tumor and nontumor cells. In conclusion, we obtained an overview of the GIST microenvironment and revealed the heterogeneity of each cell type and their relevance to risk classifications, which provided a novel theoretical basis for learning and curing GISTs.

Efficacy and safety of over-the-scope-clips in the therapy of acute nonvariceal upper gastrointestinal bleeding: Meta-analysis.

BACKGROUND: Acute nonvariceal upper gastrointestinal bleeding (ANVUGIB) is a frequent life-threatening acute condition in gastroenterology associated with high morbidity and mortality. Over-the-scope-clip (OTSC) is a new endoscopic hemostasis technique, which is being used in ANVUGIB and is more effective. AIM: To summarize and analyze the effects of the OTSC in prevention of recurrent bleeding, clinical success rate, procedure time, hospital stay, and adverse events in the treatment of ANVUGIB, to evaluate whether OTSC can replace standard endoscopic therapy as a new generation of treatment for ANVUGIB. METHODS: The literature related to OTSC and standard therapy for ANVUGIB published before January 2023 was searched in PubMed, Web of Science, EMBASE, Cochrane, Google, and CNKI databases. Changes in recurrent bleeding (7 or 30 days), clinical results (clinical success rate, conversion rate to surgery, mortality), therapy time (procedure time, hospital stay), and adverse events in the OTSC intervention group were summarized and analyzed, and the MD or OR of 95%CI is calculated by Review Manager 5.3. RESULTS: This meta-analysis involved 11 studies with 1266 patients. Total risk of bias was moderate-to-high. For patients in the OTSC group, 7- and 30-days recurrent bleeding rates, as well as procedure time, hospital stay, and intensive care unit stay, were greatly inhibited. OTSC could significantly improve the clinical success rate of ANVUGIB. OTSC therapy did not cause serious adverse and was effective in reducing patient mortality. CONCLUSION: OTSC may provide more rapid and sustained hemostasis, and thus, promote recovery and reduce mortality in patients with ANVUGIB. In addition, the safety of OTSC is assured.

N-acetyl-L-leucine protects MPTP-treated Parkinson's disease mouse models by suppressing Desulfobacterota via the gut-brain axis.

Parkinson's disease (PD) is the second most common neurodegenerative disease, and communication between the gut and brain (the gut-brain axis) has been found to be essential in behavior and cognitive function. However, the exact mechanisms underlying microbiota dysbiosis in PD progression have not yet been elucidated. Our study aimed to investigate the correlation between gut microbiota disturbances and feces metabolic disorders in PD. We used 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce PD models and observed mice's motor symptoms, dopaminergic (DA) neuron death, and gastrointestinal dysfunction. To identify alterations in microbiota and metabolome, feces were collected from mice and analyzed using 16 S ribosomal RNA sequencing feces metabolomics. Pearson analysis was utilized to investigate correlations between the abundances of gut microbiota components and the levels of gut microbiota metabolites, displaying their interaction networks. Our findings revealed a significant increase in Desulfobacterota in the PD mouse model and 151 differentially expressed fecal metabolites between PD and vehicle mice. Moreover, Pearson correlation analysis suggested that the protective factor N-acetyl-L-leucine (NALL) may be associated with neuroinflammation in the striatum and substantia nigra, which also had a negative relationship with the concentration of Desulfobacterota. Additionally, we found that oral administration of NALL alleviated MPTP-induced Motor Impairments and DA neuronal deficits. All in all, we concluded that the decrease of NALL might lead to a significant increase of Desulfobacterota in the MPTP model mouse and subsequently result in the damage of DA neurons via the gut-brain aix pathway.