Identification of marker genes associated with N6-methyladenosine and autophagy in ulcerative colitis

BACKGROUND

Both N6-methyladenosine (m6A) methylation and autophagy are considered relevant to the pathogenesis of ulcerative colitis (UC). However, a systematic exploration of the role of the com-bination of m6A methylation and autophagy in UC remains to be performed.

AIM

To elucidate the autophagy-related genes of m6A with a diagnostic value for UC.

METHODS

The correlation between m6A-related genes and autophagy-related genes (ARGs) was analyzed. Finally, gene set enrichment analysis (GSEA) was performed on the characteristic genes. Additionally, the expression levels of four characteristic genes were verified in dextran sulfate sodium (DSS)-induced colitis in mice.

RESULTS

GSEA indicated that BAG3, P4HB and TP53INP2 were involved in the inflammatory response and TNF-α signalling via nuclear factor kappa-B. Furthermore, polymerase chain reaction results showed significantly higher mRNA levels of BAG3 and P4HB and lower mRNA levels of FMR1 and TP53INP2 in the DSS group compared to the control group.

CONCLUSION

This study identified four m6A-ARGs that predict the occurrence of UC, thus providing a scientific reference for further studies on the pathogenesis of UC.

Clinicopathological features and expression of regulatory mechanism of the Wnt signaling pathway in colorectal sessile serrated adenomas/polyps with different syndrome types

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer worldwide, with the fourth highest mortality among all cancers. Reportedly, in addition to adenomas, serrated polyps, which account for 15%-30% of CRCs, can also develop into CRCs through the serrated pathway. Sessile serrated adenomas/polyps (SSAs/Ps), a type of serrated polyps, are easily misdiagnosed during endoscopy.

AIM

To observe the difference in the Wnt signaling pathway expression in SSAs/Ps patients with different syndrome types.

METHODS

From January 2021 to December 2021, patients with SSAs/Ps were recruited from the Endoscopy Room of Shanghai Traditional Chinese Medicine-Integrated Hospital, affiliated with Shanghai University of Traditional Chinese Medicine. Thirty cases each of large intestine damp-heat (Da-Chang-Shi-Re, DCSR) syndrome and spleen-stomach weakness (Pi-Wei-Xu-Ruo) syndrome were reported. Baseline comparison of the general data, typical tongue coating, colonoscopy findings, and hematoxylin and eosin findings was performed in each group. The expression of the Wnt pathway-related proteins, namely β-catenin, adenomatous polyposis coli, and mutated in colorectal cancer, were analyzed using immunohistochemistry.

RESULTS

Significant differences were observed with respect to the SSAs/Ps size between the two groups of patients with different syndrome types (P = 0.001). The other aspects did not differ between the two groups. The Wnt signaling pathway was activated in patients with SSAs/Ps belonging to both groups, which was manifested as β-catenin protein translocation into the nucleus. However, SSAs/Ps patients with DCSR syndrome had more nucleation, higher β-catenin expression, and negative regulatory factor (adenomatous polyposis coli and mutated in colorectal cancer) expression (P < 0.0001) than SSA/P patients with Pi-Wei-Xu-Ruo syndrome. In addition, the SSA/P size was linearly correlated with the related protein expression.

CONCLUSION

Patients with DCSR syndrome had a more obvious Wnt signaling pathway activation and a higher risk of carcinogenesis. A high-quality colonoscopic diagnosis was essential. The thorough assessment of clinical diseases can be improved by combining the diseases of Western medicine with the syndromes of traditional Chinese medicine.

Single-cell RNA-sequencing combined with bulk RNA-sequencing analysis of peripheral blood reveals the characteristics and key immune cell genes of ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a complicated disease caused by the interaction between genetic and environmental factors that affects mucosal homeostasis and triggers an inappropriate immune response. Single-cell RNA sequencing (scRNA-seq) can be used to rapidly obtain the precise gene expression patterns of thousands of cells in the intestine, analyze the characteristics of cells with the same phenotype, and provide new insights into the growth and development of intestinal organs, the clonal evolution of cells, and immune cell changes. These findings can provide new ideas for the diagnosis and treatment of intestinal diseases.

AIM

To identify clinical phenotypes and biomarkers that can predict the response of UC patients to specific therapeutic drugs and thus aid the diagnosis and treatment of UC.

METHODS

Using the Gene Expression Omnibus (GEO) database, we analyzed peripheral blood cell subtypes of patients with UC by scRNA-seq combined with bulk RNA sequencing (RNA-seq) to reveal the core genes of UC. We then combined weighted gene correlation network analysis (WGCNA) and least absolute shrinkage and selection operator (LASSO) analysis to reveal diagnostic markers of UC.

RESULTS

After processing the scRNA-seq data, we obtained data from approximately 24340 cells and identified 17 cell types. Through intercellular communication analysis, we selected monocyte marker genes as the candidate gene set for the prediction model. Construction of a WGCNA coexpression network identified RhoB, cathepsin D (CTSD) and zyxin (ZYX) as core genes. Immune infiltration analysis showed that these three core genes were strongly correlated with immune cells. Functional enrichment analysis showed that the differentially expressed genes were closely related to immune and inflammatory responses, which are associated with many challenges in the diagnosis and treatment of UC.

CONCLUSION

Through scRNA-seq analysis, LASSO diagnostic model building and WGCNA, we identified RhoB, CTSD and ZYX as core genes of UC that are closely related to monocyte infiltration that may serve as diagnostic markers and molecular targets for UC therapeutic intervention.

Effects of resveratrol on activation of NLRP3 inflammasome in HSC-T6 cells

AIM

To investigate the effect of resveratrol (Res) on the activation of nod-like receptor protein 3 (NLRP3) inflammasome in hepatic stellate cell (HSC)-T6 cells and to explore the anti-fibrotic mechanism of Res.

METHODS

Rat hepatic stellate cell (HSC) line HSC-T6 was used. HSC-T6 cells were seeded into cell culture plates with high glucose DMEM medium containing 10% fetal bovine serum for 24 h. Then, the cells were incubated with Res (4, 8, and 16 μmol/L) or acetylcysteine (NAC; 5 mmol/L) for 24 h. Oxidative stress (OS) was induced by exposure to hydrogen peroxide (H₂O₂; 0.2 mmol/L) for 4 h. MTT method was used to observe the effect of Res on HSC-T6 cell proliferation. ELISA was used to detect the contents of type I collagen (COL-I), transforming growth factor β1 (TGF-β1), interleukin (IL)-1β, IL-18, malondialdehyde (MDA), and superoxide dismutase (SOD) in cell culture supernatant. Reactive oxygen species (ROS) production was measured with a fluorescence microplate reader following staining with DCFH-DA probe. Western blot analysis was used to detect the expression of alpha-smooth muscle actin (α-SMA), NLRP3, apoptosis-associated speck-like protein (ASC), and cysteinyl aspartate specific proteinase 1 (caspase 1) in HSC-T6 cells.

RESULTS

Compared with control cells, Res at concentrations from 4 μmol/L to 64 μmol/L significantly suppressed the proliferation of HSC-T6 cells. Compared with control cells, OS induction significantly increased the proliferation of HSC-T6 cells, the contents of COL-1, TGF-β1, MDA, IL-1β, and IL-18 in cell culture supernatant, intracellular ROS production, and the protein expression of α-SMA, NLRP3, ASC, and caspase 1-p10 (P < 0.01), but decreased the content of SOD in cell culture supernatant (P < 0.01). Compared with the OS group, treatment with low-, medium-, or high-dose Res or positive control NAC significantly decreased the proliferation of HSC-T6 cells, the contents of COL-1, TGF-β1, MDA, IL-1β, and IL-18 in cell culture supernatant, intracellcular ROS production, and the protein expression of α-SMA, NLRP3, ASC, and caspase 1-p10 (P < 0.01), but increased the content of SOD in cell culture supernatant (P < 0.01).

CONCLUSION

Res could suppress the proliferation and activation of HSC-T6 cells via down-regulation of ROS-NLRP3 inflammasome signaling.

Effect of saikosaponin-d on expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in activated HSC-T6 cells: Underlying mechanism

AIM: To investigate the effect of saikosaponin-d (SSd) on the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and matrix metalloproteinase-1 (MMP-1) in activated HSC-T6 cells and the underlying mechanism, and to explore the mechanism of action of phytoestrogens on liver fibrosis to provide a theoretical basis for their clinical application.

METHODS: Rat hepatic stellate cell line HSC-T6 was used. Cells were seeded into cell culture plates with DMEM high glucose medium containing 10% fetal bovine serum for 24 h. After 1 h pretreatment with estrogen receptor (ER) antagonist (1 µmol/L) or P38 MAPK antagonist SB203580 (50 µmol/L), cells were incubated with SSd (5 µmol/L) or estradiol (E₂) (1 µmol/L) for 24 h. ELISA was used to detect the contents of type I collagen (COL-I), MMP-1, and TIMP-1 in cell culture supernatants. Western blot analysis was used to detect the expression of MMP-1, TIMP-1, P38 and PP38 in HSC-T6 cells.

RESULTS: Compared with the control group, SSd or E₂ treatment significantly decreased COL-1 (140.95 ± 12.14, 143.58 ± 4.81 vs 198.98 ± 15.08) and TIMP-1 contents (0.23 ± 0.01, 0.21 ± 0.01 vs 0.31 ± 0.01) in cell culture supernatants and P-P38 expression (0.51 ± 0.14, 0.52 ± 0.12 vs 1.00 ± 0.11), and significantly elevated MMP-1 content (0.0127 ± 0.0008, 0.0116 ± 0.0004 vs 0.0049 ± 0.0001, P < 0.01). In the inhibitor group, the expression levels of COL-1, TIMP-1 and P-P38 increased (P < 0.01) and MMP-1 content decreased (P < 0.01). MMP-1 expression was significantly increased in cells treated with P38 inhibitor SB203580 for 24 h compared with the control group (3.58 ± 0.35 vs 1.00 ± 0.15, P < 0.01), and TIMP-1 expression was significantly decreased (0.52 ± 0.14 vs 1.00 ± 0.18, P < 0.05).

CONCLUSION: The anti-fibrotic effect of SSd may be attributed to its inhibition of P38/MAPK activation and modulation of downstream molecules MMP-1 and TIMP-1 expression, which can promote the degradation of extracellular matrix via stimulating ERβ.

Primary hepatic tuberculosis misdiagnosed as hepatocellular carcinoma: A case report

Primary hepatic tuberculosis has a low morbidity rate. Owing to the lack of specific symptoms and signs, the misdiagnosis rate is high. This paper reports a case of primary hepatic tuberculosis which was misdiagnosed as hepatocellular carcinoma. We systematically analyze the liver masses of the patient by iconography, gross appearance and pathology, and elaborate the objective and subjective reasons for the misdiagnosis, with an aim to improve the diagnostic skills of clinicians and reduce the rate of misdiagnosis.