Dendritic cells （DCs）， as key regulatory cells in the immune system， play a significant role in the pathogenesis of autoimmune diseases. This article reviews the mechanism of action of DCs and related research advances in autoimmune liver diseases （including autoimmune hepatitis， primary biliary cholangitis， and primary sclerosing cholangitis） and autoimmune pancreatitis. By summarizing the functions and heterogeneity of DCs in these diseases， this article reveals the crucial role of DCs in the imbalance of immune tolerance and chronic inflammation. Related research findings provide an important basis for a deep understanding of the role of DCs in autoimmune liver diseases and autoimmune pancreatitis and lay a foundation for the development of precise treatment strategies.

Objective To investigate the regulatory role of the programmed cell death protein 1 (PD-1) and its ligand programmed cell death protein ligand 1 (PD-L1) signaling on the subtypes and functions of natural killer (NK) cells at the maternal-fetal interface during the second trimester in mice following Toxoplasma gondii infection during the first trimester. Methods Twelve 6- to 8-week-old female mice of the C57BL/6J strain were divided into a control group and an infection group, of 6 mice in each group. On the 6.5th day of pregnancy (Gd6.5), each pregnant mouse in the infection group was intraperitoneally injected with 150 tachyzoites of the Toxoplasma gondii PRU strain, while mice in the control group were injected with an equal volume of physiological saline. On the 12.5th day of pregnancy (Gd12.5), uterus and placenta tissues were sampled from pregnant mice for pathological observations, and the mRNA expression levels of PD-1, PD-L1, and tumor necrosis factor-α (TNF-α) were quantified in uterus and placenta tissues. The PD-1 and DX5 expression was measured on NK cells at the maternal-fetal interface using flow cytometry. In addition, the in vitro JEG-3 trophoblast cells and NK-92MI cells co-culture system was established as the control group, and the addition of T. gondii tachyzoites in the co-culture system served as the infection group. The PD-1, PD-L1, and DX5 mRNA expression was quantified in cells using real-time fluorescence quantitative reverse transcription PCR (RT-qPCR) assay, and the TNF-α concentration was measured in the cell culture supernatant using enzyme-linked immunosorbent assay (ELISA). Results On Gd12.5, clear and intact cellular structures of placental decidual tissues were seen in pregnant mice in the control group, with no remarkable abnormal changes found in the uterine columnar epithelial cells, and inflammatory cell infiltration and blood stasis at varying degrees were found in uterine and placental tissues from pregnant mice in the infection group. The relative PD-1, PD-L1, and TNF-α mRNA expression was (1.004 ± 0.004), (1.001 ± 0.001), and (1.001 ± 0.001) in uterine tissues from pregnant mice in the control group and (2.480 ± 0.720), (3.355 ± 0.920), and (2.391 ± 0.073) in the infection group, respectively. The relative PD-1, PD-L1, and TNF-α mRNA expression was (1.007 ± 0.010), (1.006 ± 0.006), and (1.001 ± 0.001) in the uterine tissues in the control group and (6.948 ± 1.918), (3.225 ± 1.034), and (1.536 ± 0.150) in the infection group, respectively. The relative PD-1, PD-L1, and TNF-α mRNA expression was higher in both the uterine (t = 3.55, 4.43 and 33.02, all P values < 0.05) and placental tissues (t = 5.36, 3.72 and 6.18, all P values < 0.05) in the infection group than in the control group. Flow cytometry showed that the proportions of PD-1⁺ NK cells, PD-1⁺ DX5⁺ NK cells, and DX5⁺ NK cells were (12.200 ± 1.082)%, (9.373 ± 7.728)%, and (44.000 ± 4.095)% in uterine tissues from pregnant mice in the control group, and (21.733 ± 1.630)%, (18.767 ± 1.242)%, and (73.367 ± 0.611)% in the infection group, respectively. The proportions of PD-1⁺ NK cells, PD-1⁺ DX5⁺ NK cells, and DX5⁺ NK cells were (1.100 ± 0.510)%, (2.277 ± 1.337)%, and (96.167 ± 2.831)% in placental tissues from mice in the control group, and (26.867 ± 9.722)%, (23.433 ± 6.983)%, and (82.467 ± 2.248)% in the infection group, respectively. The proportions of PD-1⁺ NK cells (t = 8.45, P < 0.05) and DX5⁺ NK cells (t = 12.29, P < 0.05) were higher in uterine tissues from pregnant mice in the infection group than in the control group, and no significant difference was seen in the proportion of PD-1⁺ DX5⁺ NK cells (Z = -1.09, P > 0.05). The proportions of PD-1⁺ NK cells (t = 4.58, P < 0.05) and PD-1⁺ DX5⁺ NK cells (t = 5.15, P < 0.05) were higher in placental tissues from pregnant mice in the infection group than in the control group, while the proportion of DX5⁺ NK cells was lower in the infection group than in the control group (t = -6.56, P < 0.05). RT-qPCR assay revealed that the relative PD-1, PD-L1, and DX5 mRNA expression was (1.010 ± 0.005), (1.002 ± 0.003), and (1.001 ± 0.001) in the JEG-3 cells and NK92MI cells co-culture system and (3.638 ± 1.258), (0.397 ± 0.158), and (4.267 ± 1.750) in the control group, and ELISA measured that the TNF-α concentration was higher in the cell culture supernatant in the infection group [(22.056 ± 3.205) pg/mL] than in the control group [(12.441 ± 0.001) pg/mL] (t = 5.20, P < 0.05). The PD-1(t = 3.62, P < 0.05) and DX5 mRNA expression (t = 3.23, P < 0.05) was higher in the infection group than in the control group, and the PD-L1 mRNA expression was lower in the infection group than in the control group (t = -6.63, P < 0.05). Conclusions Following T. gondii infection, both PD-L1 expression and PD-1 expression on DX5⁺ NK cells at the maternal-fetal interface are upregulated in mice during the second trimester; however, the proportion of DX5⁺ NK cells decreases. These findings suggest that PD-1/PD-L1 signaling may suppress NK cell functions by modulating DX5⁺ NK cell subsets.

Objective:To explore the characteristics of SMN1 gene variants and carry out functional verification for two children with Spinal muscular atrophy (SMA). Methods:Two male children with complicated SMA diagnosed at the Children′s Hospital Affiliated to Capital Institute of Pediatrics respectively in July 2021 and April 2022 due to delayed or retrograde motor development were selected as the study subjects. Clinical data of the children were collected. Primary culture of skin fibroblasts was carried out, and peripheral blood samples were collected from both children and their parents. Multiplex ligation-dependent probe amplification, combined long-range PCR and nested PCR, and Sanger sequencing were carried out to detect the copy number and variants of the SMN1 gene. Absolute quantitative real-time PCR, Western blotting and immunofluorescence were used to determine the transcriptional level of the SMN gene, expression of the SMN protein, and the number of functional SMN protein complexes (gems body), respectively. This study was approved by Medical Ethics Committee of the Children′s Hospital Affiliated to Capital Institute of Pediatrics (Ethics No. SHERLLM2021009). Results:Child 1, a 1-year-old boy, was clinically diagnosed with type 1 SMA. Child 2, a 2-and-a-half-year-old boy, was clinically diagnosed with type 3 SMA. Both children were found to harbor a paternally derived SMN1 deletion and a maternally derived SMN1 gene variant, namely c. 824G>T (p.Gly275Val) and c. 884A>T (p.*295Leu). Compared with the normal controls and carriers, the levels of full-length SMN1 transcripts in their peripheral blood and skin fibroblast cell lines were significantly decreased ( P<0.05), and the levels of SMN protein normalized to that of β-actin, and the numbers of gems bodies in the primary fibroblast cells were also significantly lower ( P<0.05). Based on the guidelines from the American College of Medical Genetics and Genomics, both variants were classified as likely pathogenic (PS3+ PM3+ PM5+ PP3; PS3+ PM3+ PM4+ PP3). Following the diagnosis, both children had received nusinersen treatment. Although their motor function was improved, child 1 still died at the age of 2 due to severe pulmonary infection. The walking ability of child 2 was significantly improved, and his prognosis appeared to be good. Conclusion:Two cases of clinically complicated SMA have been confirmed by genetic testing and experimental studies, which has provided a reference for their accurate treatment.

Objective To discuss the clinical features,differential diagnosis and complication treatment of a patient with genetic visceral myopathy.Methods Medical history,physical examination and laboratory results of the patient were collected in detail.The pathology of previous surgery was reviewed.The patient's peripheral blood DNA was extracted and submitted for whole-exome sequencing.Subsequent Sanger sequencing was used to complete the pedigree verification of the mutation site.Results The patient was a young female presented with repeated in-complete intestinal obstruction since early childhood.She used to be misdiagnosed as Hirschsprung's disease for a long period and underwent multiple gastrointestinal segment resections.Her intestinal obstruction symptoms were temporarily relieved by surgeries,but severe diarrhea,mucus and bloody stools and malnutrition gradually occurred after the last operation.The patient had bacterial overgrowth in small intestinal tract and followed by intestinal op-portunistic infections secondary to chronic intestinal pseudo-obstruction.The symptoms improved after anti-infection and enteral element diet treatment.Further pathological consultation and whole-exome gene sequencing confirmed the diagnosis of visceral myopathy related to ATCG2 R148L mutation.Conclusions Patients with early onset of chronic intestinal pseudo-obstruction and have poor response to conventional treatment are recommended to perform genetic test.The patients with hereditary visceral myopathy are susceptible to opportunistic intestinal infection.At-tentions should also be paid to the prevention and treatment of complications to avoid unnecessary surgery.

Background/Aims: Crohn’s disease (CD) has a progressive nature and commonly perianal involvement. The aim of this study is to assess the prevalence, surgical treatment, and outcome of perianal fistulizing CD with associated risk factors in a large Chinese cohort. Methods: Hospitalized patients diagnosed with CD in our center were consecutively enrolled between January 2000 and December 2018. Transition of disease behavior was classified according to the presence or absence of penetrating behavior (B3 in the Montreal classification) at diagnosis and at a median follow-up of 102 months. Results: A total of 504 patients were included, of whom 207 (41.1%) were classified as B3 and 348 (69.0%) as L2/3 at follow-up. Transition of behavior to B3 was observed in 86 patients (17.1%). The incidence of perianal fistulizing lesions was 10.9% at 10 years with a final prevalence of 27.0% (n = 136) at the end of follow-up. Multivariate Cox regression identified independent risks of perianal fistulizing lesions for persistent B3 (hazard ratio, 4.72; 95% confidence interval, 1.91–11.66) and behavior transition of progressed to B3 (hazard ratio, 9.90; 95% confidence interval, 4.60–21.33). Perianal surgical treatments were performed in 104 patients (20.6%). Thirty-six cases (7.1%) were refractory, and it is independently associated with behavior of persistent B3 (P= 0.011). Conclusions Perianal fistulizing lesions occurred frequently in Chinese CD patients. Its incidence and refractory outcome were closely associated with the penetrating CD behavior. An additional risk of perianal fistulizing lesions was indicated for CD patients with behavior of progressing to B3, suggesting further attention.

Objective:To investigate the effect of S100 calcium-binding protein A9(S100A9)activation of nuclear factor kappa-B(NF-κB)on the upregulation of toll-like receptor 7(TLR7)expression and the release of inflammatory factors in microglia,as well as its underlying mechanism.Methods:The viability of BV2 microglia was assessed using CCK-8 kit.Transcriptome sequencing was employed to compare differential genes(DEGs)and identify target genes from the pool of differentially expressed genes.This analysis was complemented by GO analysis,KEGG enrichment analysis and the STRING database.The expression of TLR7 mRNA was verified by real time RT-PCR.The expressions of CD68 and CD206 were detected using immunofluorescence.The expressions of CD68,CD206,TLR7,p65,and p-p65 were detected using Western Blot.The level of interleukin 6(IL-6)and tumor necrosis factor alpha(TNF-α)were verified by ELISA.Results:Moderate concentrations of S100A9 had no inhibitory effect on microglial viability.Compared to the control group,the experimental group showed a significant increase in the expression level of CD68 pro-tein,while the CD206 protein was decreased.This suggests that S100A9 promotes the activation of BV2 microglia into pro-inflammatory types.TAK-242,an inhibitor of toll-like receptor 4(TLR4),significantly inhibited the expression levels of TNF-α and IL-6 after S100A9 stimulated BV2 cells.Activation of the TLR4/NF-κB pathway promoted the ex-pression of TLR7 protein.Conclusion:The moderate concentration of S100A9 can promote the polarization of microglia towards a proinflammatory direction.It also promotes the expression of TLR7 and the release of various inflammatory factors,including TNF-α and IL-6,through the activation of the TLR4/NF-κB pathway.This activation has an obvious proinflammatory effect.

Objective:To explore the distribution of the copy number of survival motor neuron gene 2 ( SMN2) and the transcript level of the full-length SMN2 ( fl-SMN2) transcript level in patients with type 1-3 spinal muscular atrophy (SMA), and to evaluate their influences on disease severity, progression, and prognosis. Methods:It was a retrospective study involving 78 therapy-naive SMA patients with SMN1 gene homozygous deletion who were diagnosed and treated in the Capital Institute of Pediatrics from January 2019 to December 2021.Cross-sectional clinical data, including age at onset, motor milestones, and complications were recorded.They were followed up for monitoring motor function degeneration and survival.The copy number of SMN2 and the transcript level of fl-SMN2 were detected.Differences between groups were compared by the Student′s t-test or One- Way ANOVA or Chi- square test.Kaplan-Meier analysis was used for survival analysis, and Kendall′ s tau- c was performed to assess the correlation of these two biomarkers with SMA phenotypes, age at onset, motor milestones, and survival. Results:Of the 78 SMA patients, there were 17 cases (21.8%) of type 1, 34 cases(43.6%) of type 2, and 27 cases(34.6%) of type 3.Seven cases(41.2%) type 1 SMA patients died, with a median survival time of 11 months, and no deaths were observed in type 2 and type 3 SMA patients.There was a significant difference in the median age at onset among SMA patients with 2, 3, and 4 copies of SMN2 (1.8, 12.0, and 24.0 months, respectively; F=4.943, P=0.01). The mean transcript level of fl-SMN2 in type 1, 2 and 3 SMA patients were 196.25±68.79, 331.21±108.79 and 455.69±122.27, respectively ( F=37.154, P<0.001). The survival rate of SMA with 2 SMN2 copies at 1, 2, and 5 years were 50.5%, 0, and 0, respectively, and their median survival age was 7 months.The survival rate of SMA with 3 and 4 SMN2 copies at 5 years were 97.4% and 100.0%, respectively.Moreover, a negative correlation was observed between the transcript level of fl-SMN2 and phenotype severity ( Kendall′ s tau- c=-0.444, P<0.001), and the transcript level of fl-SMN2 of the survival group was much higher than that of the death group (342.93±125.74 vs.212.14±92.31). More copies of SMN2 and higher transcript level of fl- SMN2 indicated more motor function acquisitions (head control, sitting and walking) ( P<0.001). In addition, there was a significant difference in the transcription level of fl-SMN2 between the undegenerated group and the degenerated group in sitting and standing ( F=5.432, P=0.023 and F=4.315, P=0.047, respectively). Conclusions:Both the copy number of SMN2 and the transcript level of fl-SMN2 are correlated with SMA severity, survival, and motor milestones, serving as valuable biomarkers for evaluating phenotypic severity of SMA.The transcript level of fl-SMN2 s may play an important role in the degeneration of sitting and standing.

Inflammatory bowel disease (IBD) is a non-specific inflammatory disease of the gastrointestinal (GI) tract that is generally accepted to be closely related to intestinal dysbiosis in the host. GI infections contribute a key role in the pathogenesis of IBD; however, although the results of recent clinical studies have revealed an inverse correlation between Helicobacter pylori (H. pylori) infection and IBD, the exact mechanism underlying the development of IBD remains unclear. H. pylori, as a star microorganism, has been a focus for decades, and recent preclinical and real-world studies have demonstrated that H. pylori not only affects the changes in the gastric microbiota and microenvironment but also influences the intestinal microbiota, indicating a potential correlation with IBD. Detailed analysis revealed that H. pylori infection increased the diversity of the intestinal microbiota, reduced the abundance of Bacteroidetes, augmented the abundance of Firmicutes, and produced short-chain fatty acid-producing bacteria such as Akkermansia. All these factors may decrease vulnerability to IBD. Further studies investigating the H. pylori-intestinal microbiota metabolite axis should be performed to understand the mechanism underlying the development of IBD.
Chronic Disease ; Dysbiosis/microbiology* ; Gastrointestinal Microbiome ; Helicobacter Infections ; Helicobacter pylori ; Humans ; Inflammatory Bowel Diseases/microbiology* ; Microbiota

Since the rising rates of obesity, alcohol consumption and tobacco smoking, along with the improvement in quality of clinical diagnosis, the incidence of pancreatitis continues growing and causes a huge socioeconomic burden. How to prevent pancreatitis effectively has become a major medical and social issue. This article reviewed the holistic preventive strategies and measures of pancreatitis at primary, secondary and tertiary levels for decreasing the incidence of pancreatitis and its sequelae, and improving the prognosis of patients.