Downregulated APOD and FCGR2A correlates with immune infiltration and lipid-induced symptoms of irritable bowel syndrome.

Fat intake is among the most significant triggers for symptom development in patients with irritable bowel syndrome (IBS). Nevertheless, long-term restriction in fatty foods ingestion may lead to nutritional inadequacies. This study aimed to identify the crucial genes involved in lipid-induced gastrointestinal symptoms, contributing to helping IBS patients regulate fat. The clinical characteristics of the subjects were collected by questionnaire investigation and analyzed using multivariate logistic regression. Differentially expressed genes (DEG) and signaling pathways were analyzed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. ImmuInfiltration and CIBERSORT packages evaluated small intestine immune cell infiltration. Random forest and SVM-RFE algorithms were used to select hub genes. A receiver operating characteristic curve was used to access the diagnostic significance of each hub gene. Gene Set Enrichment Analysis (GSEA) was performed to identify hub genes' molecular processes in IBS development after lipid infusion. IBS patients' risk, severity, and quality of life increased with fat intake. In total, 116 robust DEGs were identified in IBS patients after lipid infusion using the GSE166869 dataset and were mainly clustered in the immune and inflammatory pathways. IBS patients had greater Neutrophils, CD4+ T cells, and M1 Macrophages than healthy controls. Furthermore, infiltration levels of Neutrophils and resting memory CD4+ T cells were inversely related to the expression of hub genes (IGKV1D-43, IGKV1-12, APOD, FCGR2A and IGKV2-29). After lipid infusion, GSEA results of each hub gene indicated the relevance of proinflammatory pathways in IBS pathogenesis. After verification, only APOD and FCGR2A were stably downregulated in small intestinal mucosa and plasma of IBS patients. The area under the curve of APOD combined with FCGR2A expression was 0.9. APOD and FCGR2A may be promising biomarkers for IBS diagnosis and lipid-sensitive IBS patients. Their potential roles in the immune microenvironment of the small intestinal mucosa may provide a vital clue to IBS precision therapy.

Validation of diagnostic strategies of autoimmune atrophic gastritis: A case report.

BACKGROUND: Autoimmune atrophic gastritis (AAG) is a type of chronic gastritis that mainly affects the gastric corpus. Due to the lack of standard diagnostic criteria and overlaps with the courses of Helicobacter pylori-related atrophic gastritis, reports on the diagnostic strategy of AAG at an early stage are limited. CASE SUMMARY: A 71-year-old woman with severe anemia was diagnosed with AAG. Endoscopic views and pathological findings showed the coexistence of normal mucosa in the gastric antrum and atrophic mucosa in the gastric fundus. Serological tests showed that anti-parietal cell antibodies and anti-intrinsic factor antibodies were both positive. Immunohistochemical results, which showed negative H+-K+ ATPase antibody staining and positive chromogranin A (CgA) staining, confirmed the mechanism of this disease. After vitamin B12 and folic acid supplementation, the patient recovered well. CONCLUSION: Successful diagnosis of AAG includes serological tests, endoscopic characteristics, and immunohistochemistry for H+-K+ ATPase and CgA antibodies.

[The impact and mechanism of glutamate transporter 1-mediated visceral nociception and hyperalgesia following exposure to post-traumatic stress disorder-like stress in spinal cord of rats].

OBJECTIVE: To investigate the expression of glutamate transporter 1 (GLT-1) and determine the effect of GLT-1 overexpression on the visceromotor response ( VMR ) to colorectal distention (CRD) following exposure to post-traumatic stress disorder (PTSD)-like stress. METHODS: A beta-lactam antibiotic, ceftriaxone (CTX) was used to selectively induce transcription of the gene encoding GLT-1 and upregulate GLT-1 expression as an agonist. SD rats were divided into five groups, including control group, PTSD group, CTX-treated group, PTSD+CTX group, PTSD+CTX+ dihydrokainate (DHK) group. Seven rats in each VMR-CRD group eventually completed the study. Ten rats in each group were used to test immunofluorescence of GLT-1, however, 8, 9, 8, 10, 7 rats completed the test respectively. The animal model of PTSD was established using basal ovalbumin (OVA)-sensitization combined with single-prolonged stress model (SPS). The alteration of visceral sensitivity following exposure to PTSD-like stress was evaluated by measuring the VMR to CRD. Spinal GLT-1 expression was evaluated by immunofluorescence using confocal laser scanning microscopy. RESULTS: By immunofluorescence analysis, CTX-treated rats exhibited an increased GLT-1 expression in spinal cord compared with the control group (absorbance: 141.38 ± 2.91 vs 106.25 ± 3.32, P = 0.001). Absorbance of GLT-1 in spinal cord was significantly decreased in PTSD rats, compared with the control rats (86.11 ± 2.73 vs 106.25 ± 3.32, P = 0.001). GLT-1 expression in PTSD rats treated with CTX was significantly increased compared with PTSD group (98.70 ± 3.19 vs 86.11 ± 2.73, P = 0.004 ). VMR to CRD significantly elevated in PTSD group compared with the control group at 20, 40, 60 and 80 mmHg (all P < 0.05, 1 mmHg = 0.133 kPa). VMR significantly declined in PTSD rats treated with CTX when compared with the vehicle at graded CRD pressure (all P < 0.01), however, one-hour pretreatment with selective GLT-1 antagonist dihydrokainate reversed the blunted VMR to CRD produced by CTX (P = 0.002). VMR significantly decreased in CTX group compared with the control group at 40, 60 and 80 mmHg (all P < 0.05). CONCLUSIONS: The study suggests that the PTSD alters visceral sensitivity and GLT-1 overexpression mediated the analgesic effect of CTX following exposure to PTSD-like stress, identifying a specific molecular mechanism for visceral hypersensitivity which may pave the way for novel therapeutic strategies for PTSD-like conditions.