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Abstract Background Our previous study has demonstrated a decreased colonic CD8+CD39+ T cells, enrichment of granzyme A (GZMA), was found in pediatric-onset colitis and inflammatory bowel disease (IBD) characterized by impaired intestinal barrier function. However, the influence of GZMA on intestinal barrier function remains unknown. Methods Western blotting(WB), real-time PCR (qPCR), immunofluorescence (IF) and in vitro permeability assay combined with intestinal organoid culture were used to detect the effect of GZMA on intestinal epithelial barrier function in vivo and in vitro. Luciferase, immunoprecipitation (IP) and subcellular fractionation isolation were performed to identify the mechanism through which GZMA modulated intestinal epithelial barrier function. Results Herein, we, for the first time, demonstrated that CD8+CD39+ T cells promoted intestinal epithelial barrier function through GZMA, leading to induce Occludin(OCLN) and Zonula Occludens-1(ZO-1) expression, which was attributed to enhanced CDX2-mediated cell differentiation caused by increased glutathione peroxidase 4(GPX4)-induced ferroptosis inhibition in vivo and in vitro. Mechanically, GZMA inhibited intestinal epithelial cellular PDE4B activation to trigger cAMP/PKA/CREB cascade signaling to increase CREB nuclear translocation, initiating GPX4 transactivity. In addition, endogenous PKA interacted with CREB, and this interaction was enhanced in response to GZMA. Most importantly, administration of GZMA could alleviate DSS-induced colitis in vivo. Conclusion These findings extended the novel insight of GZMA contributed to intestinal epithelial cell differentiation to improve barrier function, and enhacement of GZMA could be a promising strategy to patients with IBD.

Abstract Patients with glycogen storage disease type Ib (GSD‐Ib) frequently have inflammatory bowel disease (IBD). however, the underlying etiology remains unclear. Herein, this study finds that digestive symptoms are commonly observed in patients with GSD‐Ib, presenting as single or multiple scattered deep round ulcers, inflammatory pseudo‐polyps, obstructions, and strictures, which differ substantially from those in typical IBD. Distinct microbiota profiling and single‐cell clustering of colonic mucosae in patients with GSD are conducted. Heterogeneous oral pathogenic enteric outgrowth induced by GSD is a potent inducer of gut microbiota immaturity and colonic macrophage accumulation. Specifically, a unique population of macrophages with high CCL4L2 expression is identified in response to pathogenic bacteria in the intestine. Hyper‐activation of the CCL4L2‐VSIR axis leads to increased expression of AGR2 and ZG16 in epithelial cells, which mediates the unique progression of IBD in GSD‐Ib. Collectively, the microbiota‐driven pathomechanism of IBD is demonstrated in GSD‐Ib and revealed the active role of the CCL4L2‐VSIR axis in the interaction between the microbiota and colonic mucosal immunity. Thus, targeting gut dysbiosis and/or the CCL4L2‐VISR axis may represent a potential therapy for GSD‐associated IBD.

Background/Aims: The aim of this study was to explore the risk factors for the incidence of gastroscopy-assisted capsule endoscopy and the small bowel transit time in pediatric patients who underwent capsule endoscopy examination. Materials and Methods: A retrospective analysis was performed to analyze the clinical data collected from pediatric patients who underwent capsule endoscopy examination. Results: A total of 239 pediatric patients were enrolled in this study. About 196 (82.0%) patients completed the entire small bowel capsule endoscopy examination, while 3 (1.3%) patients were subjected to capsule retention. Only age, not gender, height, body weight, body mass index, chief complaint, and intestinal preparation medications, has been identified as a risk factor for the incidence of gastroscopy-assisted capsule endoscopy (P < .05) by multivariate logistic regression. Further analysis showed that the small bowel transit time in the self-swallowed group was shorter than that in the gastroscopy-assisted group, while no significant difference was obtained in other factors, including intestinal preparation medications, metoclopramide, and lesions in the small intestine, which did not significantly affect small bowel transit time compared with the corresponding control group (P > .05). Conclusion: A comprehensive assessment is required before performing capsule endoscopy, because age has been identified as a critical risk factor for the incidence of gastroscopy-assisted capsule endoscopy in pediatric patients.

Abstract Introduction Self-limited infantile epilepsy (SeLIE) is a benign epilepsy. Previous studies have shown that monotherapy with most antiseizure medications can effectively relieve seizures in patients with SeLIE, but the efficacy of levetiracetam has not been investigated. Objective This study aimed to investigate the efficacy of levetiracetam in the treatment of SeLIE patients with PRRT2 mutations. Methods The clinical data of 39 SeLIE patients (21 males and 18 females, aged 4.79 ± 1.60 months) with pathogenic variants in PRRT2 or 16p11.2 microdeletion were retrospectively analyzed. Based on the use of initial antiseizure medication (ASM), the patients were classified into two groups: Levetiracetam group (LEG) and Other ASMs group (OAG). The difference of efficacy between the two groups was compared. Results Among the 39 SeLIE patients, 16 were LEG (10 males and 6 females, aged 5.25 ± 2.07 months), with whom two obtained a seizure-free status (12.50%) and 14 ineffective or even deteriorated (87.50%). Among the 14 ineffective or deteriorated cases, 13 were seizure-controlled after replacing levetiracetam with other ASMs including topiramate, oxcarbazepine, lamotrigine, and valproate, and the remaining one finally achieved remission at age 3. Of the 39 patients, 23 were OAG (11 males and 12 females; aged 4.48 ± 1.12 months), of whom 22 achieved seizure remission, except for one patient who was ineffective with topiramate initially and relieved by oxcarbazepine instead. Although there were no significant differences in gender and age of onset between the two groups, the effective rate was significantly different (12.50% in LEG vs. 95.65% in OAG) (P

Abstract Background Metabolic reprogramming is a critical event for cell fate and function, making it an attractive target for clinical therapy. The function of metabolic reprogramming in Helicobacter pylori (H. pylori)-infected gastric intestinal metaplasia remained to be identified. Methods Xanthurenic acid (XA) was measured in gastric cancer cells treated with H. pylori or H. pylori virulence factor, respectively, and qPCR and WB were performed to detect CDX2 and key metabolic enzymes expression. A subcellular fractionation approach, luciferase and ChIP combined with immunofluorescence were applied to reveal the mechanism underlying H. pylori mediated kynurenine pathway in intestinal metaplasia in vivo and in vitro. Results Herein, we, for the first time, demonstrated that H. pylori contributed to gastric intestinal metaplasia characterized by enhanced Caudal-related homeobox transcription factor-2 (CDX2) and mucin2 (MUC2) expression, which was attributed to activation of kynurenine pathway. H. pylori promoted kynurenine aminotransferase II (KAT2)-mediated kynurenine pathway of tryptophan metabolism, leading to XA production, which further induced CDX2 expression in gastric epithelial cells. Mechanically, H. pylori activated cyclic guanylate adenylate synthase (cGAS)-interferon regulatory factor 3 (IRF3) pathway in gastric epithelial cells, leading to enhance IRF3 nuclear translocation and the binding of IRF3 to KAT2 promoter. Inhibition of KAT2 could significantly reverse the effect of H. pylori on CDX2 expression. Also, the rescue phenomenon was observed in gastric epithelial cells treated with H. pylori after IRF3 inhibition in vitro and in vivo. Most importantly, phospho-IRF3 was confirmed to be a clinical positive relationship with CDX2. Conclusion These finding suggested H. pylori contributed to gastric intestinal metaplasia through KAT2-mediated kynurenine pathway of tryptophan metabolism via cGAS-IRF3 signaling, targeting the kynurenine pathway could be a promising strategy to prevent gastric intestinal metaplasia caused by H. pylori infection. Video Abstract

Objective. Microfold cells (M cells) are specific intestinal epithelial cells for monitoring and transcytosis of antigens, microorganisms, and pathogens in the intestine. However, the mechanism for M-cell development remained elusive. Materials and Methods. Real-time polymerase chain reaction, immunofluorescence, and western blotting were performed to analyze the effect of sorbitol-regulated M-cell differentiation in vivo and in vitro, and luciferase and chromatin Immunoprecipitation were used to reveal the mechanism through which sorbitol-modulated M-cell differentiation. Results. Herein, in comparison to the mannitol group (control group), we found that intestinal M-cell development was inhibited in response to sorbitol treatment as evidenced by impaired enteroids accompanying with decreased early differentiation marker Annexin 5, Marcksl1, Spib, sox8, and mature M-cell marker glycoprotein 2 expression, which was attributed to downregulation of receptor activator of nuclear factor kappa-В ligand (RANKL) expression in vivo and in vitro. Mechanically, in the M-cell model, sorbitol stimulation caused a significant upregulation of phosphodiesterase 4 (PDE4) phosphorylation, leading to decreased protein kinase A (PKA)/cAMP-response element binding protein (CREB) activation, which further resulted in CREB retention in cytosolic and attenuated CREB binds to RANKL promoter to inhibit RANKL expression. Interestingly, endogenous PKA interacted with CREB, and this interaction was destroyed by sorbitol stimulation. Most importantly, inhibition of PDE4 by dipyridamole could rescue the inhibitory effect of sorbitol on intestinal enteroids and M-cell differentiation and mature in vivo and in vitro. Conclusion. These findings suggested that sorbitol suppressed intestinal enteroids and M-cell differentiation and matured through PDE4-mediated RANKL expression; targeting to inhibit PDE4 was sufficient to induce M-cell development.

BackgroundInflammatory bowel disease (IBD) is a chronic immune-mediated disorder affecting millions worldwide. Due to the complexity of its pathogenesis, the treatment options for IBD are limited. This study focuses on ELF4, a member of the ETS transcription factor family, as a target to elucidate its role in IBD and investigate its mechanism of action in alleviating IBD symptoms by activating IL1RN transcription to suppress the activity of inflammatory TH17 cells.MethodsUsing the GEO database, this study examined LPS-induced intestinal inflammatory genes and their regulation mechanisms. We examined the colon length of LPS-treated mice and derived the Disease Activity Index (DAI). H&E staining, ELISA, and flow cytometry were used to detect mice colon tissue damage, inflammatory factor levels in mouse serum, mouse macrophage types and inflammatory TH17 cell activity. RT-qPCR and Western blot detected ELF4, IL1RN, M1, and M2 polarization markers. In Vitro, using dual-luciferase and ChIP assays, we tested mouse bone marrow-derived macrophages (BMDMs) and mouse intestinal epithelial cells for IL1RN promoter activity and ELF4 enrichment.ResultsBioinformatics showed that LPS-induced colitis animals have reduced ELF4 expression in their colon tissue. In vivo tests confirmed reduced ELF4 expression in mice with LPS-induced colitis. ELF4 overexpression reduced mouse intestinal inflammation. ELF4 activated IL1RN transcription in bioinformatics and in vitro tests. ELF4 promoted IL1RN transcription and macrophage M2 polarization to limit intestinal epithelial cell death and inflammation and reduce mouse intestinal inflammation in vitro. ELF4 also reduced the Th17/Treg ratio by increasing IL1RN transcription.ConclusionELF4 activates IL1RN transcription, suppresses inflammatory TH17 cells, and induces macrophage M2 polarization to treat IBD.

Vimentin is an intermediate filament protein responsible for maintaining cell shape. Here, the authors characterise the role of the Salmonella effector SopB on the vimentin network and its contribution to infection.

Background The number of neutrophils is significantly reduced in myelodysplastic syndrome (MDS), but the molecular basis remains unclear. We recently found that miR-34a was significantly increased in MDS neutrophils. Therefore, this study aims to clarify the effects of aberrant miR-34a expression on neutrophil counts.Methods miR-34a mimics/inhibitor transfection were performed in neutrophil-like differentiated HL60 (dHL60) cells, and a FACSCalibur flow cytometer was used to measure ROS production and apoptosis. In addition, the Cdc42-WASP-Arp2/3 pathway inhibitor (ML141) and activator (CN02) treated the dHL60 cells, and then ROS production, apoptosis and related proteins expression were detected. And, luciferase reporter assay to verify the relationship of miR-34a and the Cdc42-WASP-Arp2/3 pathway.Results overexpression of miR-34a could induce ROS production and apoptosis, decrease the expression levels of DOCK8, p-WASP, WASP, Arp2, Arp3, and increase F-actin’s expression. Meanwhile, knockdown of miR-34a could decrease ROS production and apoptosis, increase the expression of DOCK8, p-WASP, WASP, Arp2, Arp3, and decrease F-actin’s expression. Immunofluorescence staining showed aberrant miR-34a and Cdc42-WASP-Arp2/3 pathway could induce F-actin membrane transfer. Luciferase reporter assay indicated that DOCK8 was a direct target gene of miR-34a.Conclusion These data indicates miR-34a may induce neutrophil apoptosis by regulating Cdc42-WASP-Arp2/3 pathway-mediated F-actin remodeling and ROS production.

Myelodysplastic syndromes (MDS) are a group of heterogeneous myeloid clonal diseases that are characterized by ineffective bone marrow hematopoiesis. Since studies have confirmed the significance of miRNAs in ineffective hematopoiesis in MDS, the current report elucidated the mechanism mediated by miR-155-5p. The bone marrow of MDS patients was collected to detect miR-155-5p and to analyze the correlation between miR-155-5p and clinicopathological variables. Isolated bone marrow CD34+ cells were transfected with lentiviral plasmids that interfere with miR-155-5p, followed by apoptosis analysis. Finally, miR-155-5p-targeted regulation of RAC1 expression was identified, as well as the interaction between RAC1 and CREB, the co-localization of RAC1 and CREB, and the binding of CREB to miR-15b. As measured, miR-155-5p was upregulated in the bone marrow of MDS patients. Further cell experiments validated that miR-155-5p promoted CD34+ cell apoptosis. miR-155-5p could reduce the transcriptional activity of miR-15b by inhibiting RAC1, dissociating the interaction between RAC1 and CREB, and inhibiting the activation of CREB. Upregulating RAC1, CREB, or miR-15b could reduce miR-155-5p-mediated apoptosis promotion on CD34+ cells. Additionally, miR-155-5p could force PD-L1 expression, and this effect was impaired by elevating RAC1, CREB, or miR-15b. In conclusion, miR-155-5p mediates PD-L1-mediated apoptosis of CD34+ cells in MDS by RAC1/CREB/miR-15b axis, thereby inhibiting bone marrow hematopoiesis.

BackgroundEchovirus type 11(E-11) can cause fatal haemorrhage-hepatitis syndrome in neonates. This study aims to investigate clinical risk factors and early markers of E-11 associated neonatal haemorrhage-hepatitis syndrome.MethodsThis is a multicentre retrospective cohort study of 105 neonates with E-11 infection in China. Patients with haemorrhage-hepatitis syndrome (the severe group) were compared with those with mild disease. Clinical risk factors and early markers of haemorrhage-hepatitis syndrome were analysed. In addition, cytokine analysis were performed in selective patients to explore the immune responses.ResultsIn addition to prematurity, low birth weight, premature rupture of fetal membrane, total parenteral nutrition (PN) (OR, 28.7; 95% CI, 2.8–295.1) and partial PN (OR, 12.9; 95% CI, 2.2–77.5) prior to the onset of disease were identified as risk factors of developing haemorrhage-hepatitis syndrome. Progressive decrease in haemoglobin levels (per 10 g/L; OR, 1.5; 95% CI, 1.1–2.0) and platelet (PLT)

Uncontrolled inflammation occurred in sepsis results in multiple organ injuries and shock, which contributes to the death of patients with sepsis. However, the regulatory mechanisms that restrict excessive inflammation are still elusive. Here, we identified an Ig-like receptor called signaling lymphocyte activation molecular family 7 (SLAMF7) as a key suppressor of inflammation during sepsis. We found that the expression of SLAMF7 on monocytes/macrophages was significantly elevated in patients with sepsis and in septic mice. SLAMF7 attenuated TLR-dependent MAPK and NF-κB signaling activation in macrophages by cooperating with Src homology 2–containing inositol-5′‑phosphatase 1 (SHIP1). Furthermore, SLAMF7 interacted with SHIP1 and TNF receptor–associated factor 6 (TRAF6) to inhibit K63 ubiquitination of TRAF6. In addition, we found that tyrosine phosphorylation sites within the intracellular domain of SLAMF7 and the phosphatase domain of SHIP1 were indispensable for the interaction between SLAMF7, SHIP1, and TRAF6 and SLAMF7-mediated modulation of cytokine production. Finally, we demonstrated that SLAMF7 protected against lethal sepsis and endotoxemia by downregulating macrophage proinflammatory cytokines and suppressing inflammation-induced organ damage. Taken together, our findings reveal a negative regulatory role of SLAMF7 in polymicrobial sepsis, thus providing sights into the treatment of sepsis.

Objective. Vitronectin (VTN) has been reported to trigger cell pyroptosis to aggravate inflammation in our previous study. However, the function of VTN in inflammatory bowel disease (IBD) remains to be addressed. Methods. Real-time PCR and western blotting were performed to analyze VTN-regulated intestinal epithelial cell (IEC) differentiation through ferroptosis, and immunofluorescence (IF), luciferase, and chromatin immunoprecipitation were used to identify whether VTN-modulated ferroptosis is dependent on phosphodiesterase 4 (PDE4)/protein kinase A (PKA)/cyclic adenosine monophosphate-response element-binding protein (CREB) cascade pathway. In vivo experiment in mice and a pilot study in patients with IBD were used to confirm inhibition of PDE4-alleviated IECs ferroptosis, leading to cell differentiation during mucosal healing. Results. Herein, we found that caudal-related homeobox transcription factor 2-mediated IECs differentiation was impaired in response to VTN, which was attributed to enhanced ferroptosis characterized by decreased glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 expression. Inhibition of ferroptosis in IECs rescued the inhibitory effect of VTN on cell differentiation. Further analysis showed that VTN triggered phosphorylation of PDE4, leading to inhibit PKA/CREB activation and CREB nuclear translocation, which further reduced GPX4 transactivation. Endogenous PKA interacted with CREB, and this interaction was destroyed in response to VTN stimulation. What is more, overexpression of CREB in CaCO2 cells overcame the promotion of VTN on ferroptosis. Most importantly, inhibition of PDE4 by roflumilast or dipyridamole could alleviate dextran sulfate sodium-induced colitis in mice and in a pilot clinical study confirmed by IF. Conclusions. These findings demonstrated that highly expressed VTN disrupted IECs differentiation through PDE4-mediated ferroptosis in IBD, suggesting targeting PDE4 could be a promising therapeutic strategy for patients with IBD.

Abstract Background The incidence of hand foot and mouth disease (HFMD) has increased in recent years, making it a very common childhood illness worldwide. The relationship between different enterovirus genotypes and disease severity is not clearly understood. Given that enteroviruses are transmitted through the gastrointestinal tract, we hypothesized that variation in intestinal microorganisms of the host might play a role in the prognosis of HFMD. Methods We carried out a meta-transcriptomic-wide association study of fecal samples obtained from a cohort of children (254 patients, 227 tested positive for enterovirus, including 16 patients co-infectied with 2 kinds of enterovirus) with mild and severe HFMD and healthy controls. Results We found there was no significant difference in the amount of each virus type between the mild and severe cases. Genes of enterovirus 71 (EV71) and coxsackievirus A (CV-A) from the severe and mild cases did not show significant clustering. Clostridium sp. L2-50 and Bacteroides stercoris ATCC 43183 were enriched in the guts of children with severe HFMD and KEGG enrichment was found between mild and severe cases. Conclusions Intestinal microorganisms appear to interact with enterovirus to determine the progression of HFMD. Genes of Bacteroides and Clostridium may be used as predictive markers for a more efficient prognosis and intervention. The enrichment of intestinal bacteria genes with functions may facilitate the development of severe symptoms for HFMD patients.

Norovirus infection is the leading cause of foodborne gastroenteritis worldwide, causing more than 200,000 deaths each year. As a result of a lack of reproducible and robust in vitro culture systems and suitable animal models for human norovirus (HuNoV) infection, the pathogenesis of HuNoV is still poorly understood. In recent years, human intestinal enteroids (HIEs) have been successfully constructed and demonstrated to be able to support the replication of HuNoV. The NLRP3 inflammasome plays a key role in host innate immune responses by activating caspase1 to facilitate IL-1β and IL-18 secretion and N-GSDMD-driven apoptosis, while NLRP3 inflammasome overactivation plays an important role in the development of various inflammatory diseases. Here, we found that HuNoV activated enteric stem cell-derived human intestinal enteroids (HIEs) NLRP3 inflammasome, which was confirmed by transfection of Caco2 cells with full-length cDNA clones of HuNoV. Further, we found that HuNoV non-structural protein P22 activated the NLRP3 inflammasome and then matured IL-1β and IL-18 and processed the cleavage of gasdermin-D (GSDMD) to N-GSDMD, leading to pyroptosis. Besides, berberine (BBR) could ameliorate the pyroptosis caused by HuNoV and P22 by inhibiting NLRP3 inflammasome activation. Together, these results reveal new insights into the mechanisms of inflammation and cell death caused by HuNoV and provide potential treatments.

Abstract Background Helicobacter pylori (H. pylori) is a common pathogen in development of peptic ulcers with pyroptosis. Rabeprazole, a critical component of standard triple therapy, has been widely used as the first-line regimen for H. pylori infectious treatment. The aim of this study to explore the function of Rabeprazole on cell pyroptosis in vitro. Methods The clinical sample from patients diagnosed with or without H. pylori-infection were collected to analyze by Immunohistochemistry (IHC). Real-time quantitative PCR (qPCR), western blot (WB) and enzyme linked immunosorbent assay (Elisa) were performed to analyze the effect of Rabeprazole on cell pyroptosis, including LDH, IL-1β and IL-18. Results In this study, we showed that Rabeprazole regulated a phenomenon of cell pyroptosis as confirmed by lactate dehydrogenase (LDH) assay. Further results showed that Rabeprazole inhibited cell pyroptosis in gastric epithelial cells by alleviating GSDMD-executed pyroptosis, leading to decrease IL-1β and IL-18 mature and secretion, which is attributed to NLRP3 inflammasome activation inhibition. Further analysis showed that ASC, NLRP3 and Caspase-1, was significantly repressed in response to Rabeprazole stimulation, resulting in decreasing cleaved-caspase-1 expression. Most important, NLRP3 and GSDMD is significantly increased in gastric tissue of patients with H. pylori infection. Conclusion These findings revealed a critical role of Rabeprazole in cell pyroptosis in patients with H. pylori infection, suggesting that targeting cell pyroptosis is an alternative strategy in improving H. pylori treatment.

Although enterovirus D68 poses a major global threat to children, neither vaccines nor therapeutics are currently available. Using Cryo-EM, Zhang et al. show that two murine-derived monoclonal antibodies with therapeutic efficacy neutralize virions via binding to the canyon region, creating steric hindrance for sialic acid receptor binding.

The increasing incidence of drug-resistant tuberculosis is still an emergency for global public health and a major obstacle to tuberculosis treatment. Therefore, deciphering the novel mechanisms of mycobacterial antibiotic resistance is crucial for combatting the rapid emergence of drug-resistant strains. In this study, we identified an unexpected role of Mycobacterium smegmatis GntR family transcriptional regulator MSMEG_5174 and its homologous gene Mycobacterium tuberculosis Rv1152 in aminoglycoside antibiotic resistance. Deficiency of MSMEG_5174 rendered Mycobacterium smegmatis highly resistant to aminoglycoside antibiotic treatment, and ectopic expression of Rv1152 in MSMEG_5174 mutants restored antibiotic-induced bacterial killing. We further demonstrated that MSMEG_5174 negatively regulates the expression of purine metabolism-related genes and the accumulation of purine metabolites. Moreover, overexpression of xanthine dehydrogenase MSMEG_0871 or xanthine treatment elicited a significant decrease in aminoglycoside antibiotic lethality for Mycobacterium smegmatis. Together, our findings revealed MSMEG_5174 as a metabolic regulator and hint toward unexplored crosstalk between purine metabolism and antibiotic resistance.

ABSTRACT The oxacillin– and cefoxitin-susceptible mecA–positive Staphylococcus aureus is a novel “stealth” methicillin-resistant S. aureus (MRSA) type. Here, we sequenced the whole genome of two oxacillin- and cefoxitin-susceptible mecA-positive MRSA isolates from breast abscesses in a lactating woman and a nasal swab of a healthy student in Guangzhou for investigating the mechanism underlying its occurrence. The reversion of these isolates was selected by exposure to sub-MICs of cefoxitin with or without mupirocin. The mecA expression of both parental strains and their revertants was determined, and the whole genome of the revertants was sequenced. Comparative whole-genome analyses performed for both strains revealed that mecA of the clinical strain was mutated by a single-bp insertion at the 262nd position in the tandem repeat region of the gene, and this mutation that led to the formation of a premature stop codon. The colonizing strain was mutated by a novel G-to-A base substitution in the second promoter region (–35 bp) of mecA. The mecA expression level of strain 697 revertant was 37 times higher than that of the parental strain. Although the mecA expression level was even higher for parental strain 199 compared with that for its revertant, its cDNA sequence contained a single-bp insertion. Collectively, both the missense and single substitution mutations of the second promoter of mecA could render MRSA isolates as “stealth” MRSA, thereby emphasizing the importance of combining phenotype tests with mecA or penicillin-binding protein 2a detection for the identification of MRSA. IMPORTANCE The oxacillin- and cefoxitin-susceptible mecA-positive Staphylococcus aureus is a novel type of “stealth” methicillin-resistant S. aureus (MRSA), which is difficult to be detected using conventional methods. To investigate the genomic basis of their occurrence, we sequenced the whole genome of two previously recovered oxacillin- and cefoxitin-susceptible mecA-positive MRSA isolates from breast abscesses in a lactating woman and a nasal swab of a healthy student in Guangzhou. Complete SCCmec structure was absent except for mecA in clinical isolate 199. Additionally, a novel single-base pair insertion was observed in the clinical strain, which resulted in premature termination and a frameshift mutation. The colonizing isolate 697 had a Scc-mec-type IVa, and the second promoter region (–35 bp) of mecA was mutated by a novel G-to-A base substitution. The reversion of oxacillin- and cefoxitin-susceptible mecA-positive S. aureus to resistant MRSA isolates was selected by exposure to subminimum inhibitory cefoxitin with or without mupirocin.

Abstract Background Coronavirus disease 2019 (COVID-19) share similar symptoms with influenza A (IA), but it is more worthwhile to understand the disparities of the two infections regarding their clinical characteristics on admission. Methods A total of 71 age-matched pediatric IA and COVID-19 patient pairs were formed and their clinical data on admission were compared. Results Fever, cough, nasal congestion and nausea/vomiting were the most common symptoms on admission for both infections but occurred less often in COVID-19. The IA patients were more likely to have lower-than-normal levels of lymphocyte count and percentage and to have higher-than-normal levels of activated partial thromboplastin time, prothrombin time, serum C-reactive protein, and serum procalcitonin, while the COVID-19 patients had higher odds of having lower-than-normal levels of neutrophil count and percentage. Conclusions This study suggests that influenza A is more symptomatic than COVID-19 for children and might be an overall more severe infection at the time of admission.

Abstract Background The new emerging coronavirus disease 2019 (COVID-19) overall shares similar symptoms with other common respiratory viral infections. We aimed in this study to compare COVID-19 and human adenovirus (HAdV) infections in pediatric patients regarding the frequencies of major clinical symptoms and the potential disparities in laboratory and imaging parameters. Methods Following a case–control-like design, we built 72 age-matched pediatric COVID-19 and HAdV patient pairs. Their early symptoms and laboratory and imaging characteristics were then retrieved and compared. Results Fever and cough were the most common symptoms for both infections but were seen more often in HAdV than in COVID-19 patients (92% vs. 66% and 60% vs. 18%, respectively). Compared with COVID-19 patients, children with HAdV infection had statistically significantly higher values of neutrophil count, neutrophil percentage, activated partial thromboplastin time, prothrombin time, lactate dehydrogenase, C-reactive protein, procalcitonin but lower values of lymphocyte percentage, total bilirubin, potassium and sodium. Thoracic computed tomography also revealed more anomalies in HAdV patients than in COVID-19 patients (95% vs. 67%). Conclusions COVID-19 is an overall less symptomatic and less severe infection at admission compared to HAdV respiratory infection in pediatric population.

Abstract Pathogenicity of Staphylococcus aureus is induced by staphylococcal enterotoxin B (SEB). A mutant form of SEB (mSEB) is immunogenic as well as less toxic. Recombinant mSEB and SEB were expressed in pET28a prokaryotic plasmids. Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels in mSEB-stimulated macrophages were lower than those in SEB-stimulated macrophages (p

Abstract Background Mast cells (MCs) have been found to play a critical role during development of inflammatory bowel disease (IBD) that characterized by dysregulation of inflammation and impaired intestinal barrier function. However, the function of MCs in IBD remains to be fully elucidated. Results In our study, we used exosomes isolated from human mast cells-1 (HMCs-1) to culture with NCM460, HT-29 or CaCO2 of intestinal epithelial cells (IECs) to investigate the communication between MCs and IECs. We found that MCs-derived exosomes significantly increased intestinal epithelial permeability and destroyed intestinal barrier function, which is attributed to exosome-mediated functional miRNAs were transferred from HMCs-1 into IECs, leading to inhibit tight junction-related proteins expression, including tight junction proteins 1 (TJP1, ZO-1), Occludin (OCLN), Claudin 8 (CLDN8). Microarray and bioinformatic analysis have further revealed that a panel of miRNAs target different tight junction-related proteins. Interestingly, miR-223 is enriched in mast cell-derived exosome, which inhibit CLDN8 expression in IECs, while treatment with miR-223 inhibitor in HT-29 cells significantly reversed the inhibitory effect of HMCs-1-derived exosomes on CLDN 8 expression. Most importantly, enrichment of MCs accumulation in intestinal mucosa of patients with IBD compared with those healthy control. Conclusions These results indicated that enrichment of exosomal miR-223 from HMCs-1 inhibited CLDN8 expression, leading to destroy intestinal barrier function. These finding provided a novel insight of MCs as a new target for therapeutic treatment of IBD.

Human norovirus (HNV) is one of the emerging and rapidly spreading groups of pathogens and the main cause of epidemic viral gastroenteritis globally. Due to a lack of in vitro culture systems and suitable animal models for HNV infection, murine norovirus (MNV) has become a common model. A recent study showed that MNV activates NLRP3 inflammasome leading to pyroptosis. Jatrorrhizine (JAT) is a natural isoquinoline alkaloid isolated from Coptis Chinensis, which has been proven to have antibacterial, anti-inflammatory, and antitumor effects. However, whether JAT has an effect on norovirus gastroenteritis and the underlying molecular mechanism remain unclear. Here, we found that JAT could ameliorate NLRP3-N-GSDMD-dependent pyroptosis induced by MNV infection through inhibiting the MAPKs/NF-κB signaling pathways and decrease MNV replication in RAW264.7 macrophages, suggesting that JAT has the potential to be a therapeutic agent for treating norovirus gastroenteritis.

Background: Alteration of polyol pathway is a critical event in serials of disease, including inflammatory bowel disease (IBD). Shikonin, an inhibitor of PKM2, has been reported to exert a wide range of biological and pharmacological properties. However, the function of shikonin-mediated polyol pathway in IBD remained to be addressed. Methods: We conducted WB and qPCR to analyze the effect of shikonin on intestinal epithelial cell differentiation. IF, IP, luciferase assay and ChIP were employed to demonstrate the mechanism that shikonin regulated cell differentiation through polyol pathway. Elisa was used to measure the serum sorbitol in subjects enrolled in this study, and the clinical sample was collected to detect PKM2, AR and NRF2 expression. Results: Herein, we showed that shikonin treatment in HT-29 and CaCO2 cells not only contributed to CDX2 and its targets expression, including MUC2 and villin, leading to cell differentiation, but also induced NRF2-mediated AKR1B1 and AKR1B10 expression, resulting in increasing AR activity. A synergistic effect on CDX2-mediated cell differentiation was observed in CaCO2 cells in response to cotreatment with shikonin and AR agonist bortezomib for 24 hours, while aldose reductase inhibitor fidarestat treatment in CaCO2 cells reversed the enhanced CDX2 expression caused by shikonin. Mechanistically, PKM2 interacted with NRF2, and this interaction was enhanced in response to shikonin stimulation, resulting in NRF2 phosphorylation and nuclear translocation, which further increased AKR1B1 and AKR1B10 transactivation. Moreover, both AKR1B1 and AKR1B10 expression were decreased, while PKM2 was increased in intestinal epithelial cells labeled with E-cadherin in patients with IBD, and a negative clinical relationship was observed between PKM2 and AKR1B1/AKR1B10, respectively. What's more, the serum sorbitol level was decreased in patients with IBD. Conclusion: These results suggested that shikonin could promote intestinal cell differentiation through NRF2-mediated polyol pathway, implying that shikonin may be a promising therapeutic drug for the treatment of IBD.

Gastric CD4+T cells contribute to Helicobacter pylori (H. pylori)-induced gastritis by amplifying mucosal inflammation and exacerbating mucosal injuries. However, the pathogenic CD4+ T cell subset involved in gastritis and the potential regulators are still unclear. Here we identified an IL-21-producing gastric CD4+T cell subset, which exhibited tissue-resident CXCR5−BTLA−PD-1hi TFH-like phenotype in H. pylori-positive gastritis patients. Meanwhile, we identified glucocorticoid-induced tumor necrosis factor receptor (GITR) as an important regulator to facilitate IL-21 production by CD4+T cells and accelerate mucosal inflammation in gastritis patients with H. pylori infection. Moreover, GITR expression was increased in gastric CD4+T cells of gastritis patients compared to healthy controls, along with the upregulated expression of its ligand GITRL in mucosal macrophages (Mϕ) of gastritis patients. Further observations showed that the activation of GITR/GITRL signal promoted the IL-21 production of CD4+T cells via the STAT3 pathway. Besides this, IL-21 from CD4+T cells induced the proliferation of B cell and promoted the production of inflammatory cytokines IL-1β and IL-6 and chemokines MIP-3α and CCL-25 as well as matrix metalloproteinase (MMP)-3 and MMP-9 by human gastric epithelial cells, suggesting the facilitating effect of IL-21-producing CD4+T cells on mucosal inflammation and injuries. Taking these data together, we revealed that GITR/GITRL signal promoted the polarization of mucosal IL-21-producing CD4+T cells in H. pylori-positive gastritis, which may provide therapeutic strategies for the clinical treatment of H. pylori-induced gastritis.

Methicillin-susceptible (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization predisposes individuals for endogenous infections and is a major threat to children. Recently, oxacillin/cefoxitin-susceptible mecA-positive S. aureus (OS-MRSA) has been reported worldwide. Herein, a prospective, cross-sectional study was conducted across five schools, representing three educational stages, in Guangzhou, China. Nasal swabs from 2,375 students were cultured for S. aureus and all isolates were subjected to antibiotic susceptibility testing phenotypically and confirmed by femB and mecA genetic detection; all the isolates were classified as MSSA, MRSA, or OS-MRSA. All strains were also analyzed by multi-locus sequence typing. Among the 2,375 swabs, S. aureus was detected in 744 children (31.3%, 95% CI: 25.9–36.7%), of whom 72 had MRSA (3.0%, 95% CI: 0.6–5.4%) and 4 had OS-MRSA (0.2%, 95% CI: 0.1–0.3%), of which an oxacillin- and cefoxitin-susceptible MRSA strain was identified. The prevalence of S. aureus and MRSA was higher in younger children. The highest percentage of drug resistance of the S. aureus isolates (n = 744) was to penicillin (85.5%), followed by erythromycin (43.3%) and clidamycin (41.0%). The most prevalent sequence types (STs) were ST30, ST45, and ST188 in MSSA, accounting for 38.7% of the total isolates, whereas ST45, ST59, and ST338 accounted for 74.6% of the MRSA isolates and ST338 accounted for 50.0% of the OS-MRSA isolates. The MRSA and OS-MRSA isolates (n = 76) were grouped into three clades and one singleton, with clonal complex (CC) 45 as the most predominant linkage. The top nine multi-locus sequence typing-based CCs (CC30, CC45, CC5, CC1, CC15, CC944, CC398, CC59, CC7) represented 86.7% of all S. aureus isolates. All CC30 isolates were resistant to erythromycin and clidamycin, and almost all these isolates were also resistant to penicillin (99.2%). The CC45 and CC59 isolates exhibited high resistance rates to oxacillin at 31.5 and 59.0%, respectively. This study provides updated data valuable for designing effective control strategies to mitigate the burden of disease and to improve the adequacy of empirical antimicrobial treatments for potentially harmful infections.

Human norovirus (HuNoV) is the leading cause of epidemic acute gastroenteritis worldwide. Type I interferons (IFN)-α/β are highly potent cytokines that are initially identified for their essential roles in antiviral defense. It was reported that HuNoV infection did not induce IFN-β expression but was controlled in the presence of IFN-β in human intestinal enteroids and a gnotobiotic pig model, suggesting that HuNoV has likely developed evasion countermeasures. In this study, we found that a cDNA clone of GII.4 HuNoV, the predominantly circulating genotype worldwide, inhibits the production of IFN-β and identified the viral NTPase as a key component responsible for such inhibition. HuNoV NTPase not only inhibits the activity of IFN-β promoter but also the mRNA and protein production of IFN-β. Additional studies indicate that NTPase inhibits the phosphorylation and nuclear translocation of interferon-regulatory factor-3 (IRF-3), leading to the suppression of IFN-β promoter activation. Mechanistically, NTPase interacts with IkB kinase ε (IKKε), an important factor for IRF-3 phosphorylation, and such interaction blocks the association of IKKε with unanchored K48-linked polyubiquitin chains, resulting in the inhibition of IKKε phosphorylation. Further studies demonstrated that the 1-179 aa domain of NTPase which interacts with IKKε is critical for the suppression of IFN-β production. Our findings highlight the role of HuNoV NTPase in the inhibition of IFN-β production, providing insights into a novel mechanism underlying how HuNoV evades the host innate immunity.

NLRP3 inflammasome has emerged as a crucial regulator of inflammatory bowel disease (IBD) characterized by a chronic inflammatory disease of the gastrointestinal tract. The expression of MCT4 is significantly increased in intestinal mucosal tissue of IBD, which has been identified to regulate intestinal barrier function. However, the function of MCT4 in cell pyroptosis remained unknown. In this study, we have established a stable cell line with MCT4 overexpression in HT-29 and CaCO2 cells, respectively. Functional analysis revealed that ectopic expression of MCT4 in CaCO2 cells contributed to cell pyroptosis as evidenced by LDH assay, which is largely attributed to Caspase-1-mediated canonical pyroptosis, but not Caspase-4 and Caspase-5, leading to cleave pro-IL-1β and IL-18 into mature form and release mediated by cleaved GSDMD. Mechanically, MCT4 overexpression in HT-29 and CaCO2 cell triggered the phosphorylation of ERK1/2 and NF-κB p65, while inhibition of MCT4 by MCT inhibitor α-Cyano-4-hydroxycinnamic acid (α-CHCA) in HT-29 and CaCO2 cells led to a significant downregulation of ERK1/2 and NF-κB activity. What’s more, blockade of ERK1/2-NF-κB pathway could reverse the promotion effect of MCT4 on IL-1β expression. Importantly, both MCT4 and Caspase-1, GSDMD were significantly increased in patients with IBD, and a positive clinical correlation between MCT4 and Caspase-1 expression was observed (p < 0.001). Taken together, these findings suggested that MCT4 promoted Caspase-1-mediated canonical cell pyroptosis to aggravate intestinal inflammation in intestinal epithelial cells (IECs) through the ERK1/2-NF-κB pathway.

Purpose: Nontyphoidal Salmonella (NTS) is a common pathogen responsible for acute gastroenteritis among all ages; however, information on the prevalence, serotypes, and antibiotic susceptibility of NTS isolates is limited. We aimed to explore the characteristics of NTS isolated from paediatric patients in Guangzhou, China. Methods: This was a retrospective study of 4586 stool culture collected at Guangzhou Women and Children’s Medical Center from 2014 to 2016. Results: We identified 220 (4.80%) NTS isolates in stool samples. Fourteen serotypes were identified among the 220 NTS isolates. Salmonella serotype Typhimurium was the most common serotype, representing 69.09%. The highest rate of resistance was recorded in relation to AMP (76.61%), followed by SXT (29.95%), CTX (29.93%), CHL (29.77%), CAZ (23.20%), CIP (7.51%), and CFS (7.18%). The resistance rates of NTS and serotype Typhimurium to CAZ in 2015 were significantly higher than those in 2014. The average hospitalisation duration of inpatients infected by NTS resistant to three or more clinically important agents was significantly longer than that of patients infected with NTS with less antibiotic resistance. Conclusion: NTS represents a major cause of paediatric gastroenteritis in Guangzhou, China, and the high level of resistance to third-generation cephalosporins coupled with increasing resistance to quinolones among isolated NTS from paediatric gastroenteritis is a serious public health concern that requires continued monitoring and rational usage of antibiotics. Keywords: Salmonella, Gastroenteritis, Paediatric, Serotyping, Drug resistance

Background: Pancreatic carcinoma (PC) is one of the most aggressive cancers affecting human health. It is essential to identify candidate biomarkers for the diagnosis and prognosis of PC. The present study aimed to investigate the diagnosis and prognosis biomarkers of PC. Methods: Differentially expressed genes (DEGs) were identified from the mRNA expression profiles of GSE62452, GSE28735 and GSE16515. Functional analysis and the protein-protein interaction network analysis was performed to explore the biological function of the identified DEGs. Diagnosis markers for PC were identified using ROC curve analysis. Prognosis markers were identified via survival analysis of TCGA data. The protein expression pattern of the identified genes was verified in clinical tissue samples. A retrospective clinical study was performed to evaluate the correlation between the expression of candidate proteins and survival time of patients. Moreover, comprehensive analysis of the combination of multiple genes/proteins for the prognosis prediction of PC was performed using both TCGA data and clinical data. In vitro studies were undertaken to elaborate the potential roles of these biomarkers in clonability and invasion of PC cells. Findings: In total, 389 DEGs were identified. These genes were mainly associated with pancreatic secretion, protein digestion and absorption, cytochrome P450 drug metabolism, and energy metabolism pathway. The top 10 genes were filtered out following Fisher's exact test. ROC curve analysis demonstrated that TMPRSS4, SERPINB5, SLC6A14, SCEL, and TNS4 could be used as biomarkers for the diagnosis of PC. Survival analysis of TCGA data and clinical data suggested that TMC7, TMPRSS4, SCEL, SLC2A1, CENPF, SERPINB5 and SLC6A14 can be potential biomarkers for the prognosis of PC. Comprehensive analysis show that a combination of identified genes/proteins can predict the prognosis of PC. Mechanistically, the identified genes attributes to clonability and invasiveness of PC cells. Interpretation: We synthesized several sets of public data and preliminarily clarified pathways and functions of PC. Candidate molecular markers were identified for diagnosis and prognosis prediction of PC including a novel gene, TMC7. Moreover, we found that the combination of TMC7, TMPRSS4, SCEL, SLC2A1, CENPF, SERPINB5 and SLC6A14 can serve as a promising indicator of the prognosis of PC patients. The candidate proteins may attribute to clonability and invasiveness of PC cells. This research provides a novel insight into molecular mechanisms as well as diagnostic and prognostic markers of PC. Fund: National Natural Science Foundation of China [No. 81602646 & 81802339], Natural Science Foundation of Guangdong Province [No. 2016A030310254] and China Postdoctoral Science Foundation [No. 2016M600648]. Keywords: Pancreatic carcinoma, Diagnosis, Prognosis, Biomarker, Function

Background/Aims: Increasing evidence indicates that the systemic inflammatory response plays a vital role in carcinogenesis. The Glasgow Prognostic Score or modified Glasgow Prognostic Score (GPS/mGPS) is a novel inflammatory indicator which consists of CRP and albumin. Here, we performed a meta-analysis to evaluate the prognostic value of the GPS/ mGPS in patients with colorectal cancer (CRC) and to assess its consistency in different CRC therapies. Methods: The electronic databases PubMed, Embase, Scopus, Web of Science, and Cochrane Library were searched from inception through December 2017 for the association between the GPS/mGPS and clinical outcomes. Study characteristics and prognostic data were extracted from each relevant study. Overall survival (OS) and cancer-specific survival (CSS) were considered the primary outcomes, and hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. The quality of each study was pooled using the random-effects Mantel-Haenszel model. Finally, subgroup analyses were performed to detect the heterogeneity of different CRC treatments. Results: Thirty-four studies, with a combined total of 8834 patients, were eligible for this meta-analysis. Data on OS and CSS were available in 23 and 22 studies, respectively. By comparing the prognostic values of different levels of the GPS in CRC patients, the summary HRs for OS and CSS were 2.18 (95% CI 1.83-2.60) and 1.82 (95% CI 1.57-2.11), respectively. According to the different tumor stages, the subgroup analyses were stratified by different treatments, including curative or palliative therapy. The results robustly confirmed the prognostic role of the GPS/mGPS. Conclusion: Our results suggest that the GPS/mGPS is a novel and effective prognostic indicator for the OS and CSS of patients with CRC.

Mucosal associated invariant T (MAIT) cells play a critical role in Helicobacter pylori (H. pylori)-induced gastritis by promoting mucosal inflammation and aggravating mucosal injuries (1, 2). However, the underlying mechanism and key molecules involved are still uncertain. Here we identified OX40, a co-stimulatory molecule mainly expressed on T cells, as a critical regulator to promote proliferation and IL-9 production by MAIT cells and facilitate mucosal inflammation in H. pylori-positive gastritis patients. Serum examination revealed an increased level of IL-9 in gastritis patients. Meanwhile, OX40 expression was increased in mucosal MAIT cells, and its ligand OX40L was also up-regulated in mucosal dendritic cells (DCs) of gastritis patients, compared with healthy controls. Further results demonstrated that activation of the OX40/OX40L pathway promoted IL-9 production by MAIT cells, and MAIT cells displayed a highly-activated phenotype after the cross-linking of OX40 and OX40L. Moreover, the level of IL-9 produced by MAIT cells was positively correlated with inflammatory indexes in the gastric mucosa, suggesting the potential role of IL-9-producing MAIT cells in mucosal inflammation. Taken together, we elucidated that OX40/OX40L axis promoted mucosal MAIT cell proliferation and IL-9 production in H. pylori-induced gastritis, which may provide potential targeting strategies for gastritis treatment.

Human norovirus (HuNoV) is one of the major pathogens of acute nonbacterial gastroenteritis. Due to the lack of a robust and reproducible in vitro culture system and an appropriate animal model, the mechanism underlying HuNoV-caused diarrhea remains unknown. In the current study, we found that HuNoV transfection induced the expression of aquaporin 1 (AQP1), which was further confirmed in the context of virus infection, whereas the enterovirus EV71 (enterovirus 71) did not have such an effect. We further revealed that VP1, the major capsid protein of HuNoV, was crucial in promoting AQP1 expression. Mechanistically, HuNoV induces AQP1 production through the NF-κB signaling pathway via inducing the expression, phosphorylation and nuclear translocation of p65. By using a model of human intestinal epithelial barrier (IEB), we demonstrated that HuNoV and VP1-mediated enhancement of small molecule permeability is associated with the AQP1 channel. Collectively, we revealed that HuNoV induced the production of AQP1 by activating the NF-κB signaling pathway. The findings in this study provide a basis for further understanding the significance of HuNoV-induced AQP1 expression and the potential mechanism underlying HuNoV-caused diarrhea.

Background: De novo lipogenesis (DNL) has been reported to involve in a serial types of disease. A standard triple therapy, including a PPI, omeprazole, and antibiotics (clarithromycin and amoxicillin), is widely used as the first-line regimen for helicobacter pylori (H. pylori)-infectious treatment. The objective of this study is to explore the function of a standard triple therapy on DNL. Methods and results: We collected the clinical sample from the patients diagnosed with or without H. pylori infection. Oil red staining, real-time PCR, western blotting (WB) and adipored experiment were performed to detect the effect of a standard triple therapy on DNL. The expression of relative key enzymes was assessed in gastric mucosa of clinical sample by IHC. Both 54 cases with H. pylori-negative and 37 cases with H. pylori-positive were enrolled in this study, and IHC assay showed that both fatty acid synthase (FASN) and ATP-citrate lyase (ACLY) expression, the critical enzymes involved in DNL, were increased in gastric mucosa of patients with H. pylori-positive compared with that with H. pylori-negative. Real-time PCR and WB analysis showed that neither clarithromycin nor amoxicillin inhibited FASN and ACLY expression, while treatment of BGC823 cells with omeprazole with 200 μM or 300 μM significantly abolished FASN and ACLY expression, leading to reduce lipid content. Conclusion: These findings suggested that omeprazole suppressed DNL in gastric cells, implying that targeting DNL is an alternative strategy in improving the treatment of patients with H. pylori infection.

CD103 is considered as a surface marker for the resident immune cells. However, little is known about the intrinsic function of CD103 in infection and inflammation. In this study, we found that CD103 was highly expressed in CD4+T cells of the gastric mucosa from patients with H. pylori-positive gastritis. Mucosal resident CD103+CD4+T cells exhibited an increase in the CD45RO+CCR7− effector memory phenotype and high expression of the chemokine receptors CXCR3 and CCR9 compared with those in CD103−CD4+T cells. An In vitro coculture study demonstrated that H. pylori-specific antigen CagA/VacA-primed dendritic cells (DCs) induced proliferation and IFN-γ, TNF as well as IL-17 production by CD103+CD4+T cells from patients with H. pylori-positive gastritis, while blocking CD103 with a neutralizing antibody reduced proliferation and IFN-γ, TNF, and IL-17 production by CD103+CD4+T cells cocultured with DCs. Moreover, immunoprecipitation revealed that CD103 interacted with TCR α/β and CD3ζ, and activation of CD103 enhanced the phosphorylation of ZAP70 induced by the TCR signal. Finally, increased T-bet and Blimp1 levels were also observed in CD103+CD4+T cells, and activating CD103 increased T-bet and Blimp1 expression in CD4+T cells. Our results explored the intrinsic function of CD103 in gastric T cells from patients with H. pylori-positive gastritis, which may provide a therapeutic target for the treatment of gastritis.

Background:Staphylococcus aureus (S. aureus) is a major pathogen of human infections. Its fecal carriage serves as a risk factor for nosocomial transmission and disease development. However, the rate of S. aureus fecal carriage among Chinese children has not yet been reported. Therefore, we sought to investigate the prevalence, characterization, and drug resistance of S. aureus isolated from pediatric patients' feces in Southern China.Methods: Fecal samples (2059) from pediatric patients in three centers in Guangzhou were cultured. From which, 412 S. aureus isolates were identified via selective mediums and automated VITEK Mass Spectrometer analysis. Antibiotic susceptibility was determined and DNA sequencing of seven housekeeping genes were used for multilocus sequence typing analysis.Results: The fecal carriage rates were 20.0% for S. aureus and 4.5% for methicillin-resistant S. aureus (MRSA). Moreover, S. aureus fecal carriage was positively correlated with outpatient status and gastroenteritis diagnosis. Moreover, age-related patterns were observed with respect to prevalence of S. aureus. Besides, a total of 76 sequence types (STs) were identified, including 25 newly assigned STs and 28 clonal complexes (CCs). ST188, ST6, and ST15 were the most prevalent methicillin-sensitive S. aureus (MSSA) clones, while ST59 and ST45 were the major MRSA clones. S. aureus isolates also exhibited high rates of penicillin (84.2%), erythromycin (38.8%), and clindamycin (35.9%) resistance. Specifically, all ST30 and ST338 isolates were resistant to erythromycin and clindamycin, 61% of ST7 were resistant to tetracycline, and 84% of ST45 exhibited resistance and intermediate resistance to rifampicin. Also, CC59 (ST338 and ST59) and CC45 exhibited different antibiotic resistance patterns.Conclusion: These results demonstrate the colonization dynamics and molecular epidemiology of S. aureus in child feces in Southern China. Further, they suggest an urgency for strengthening the surveillance programs in China and provide important information for the prevention and treatment of S. aureus infection.

Idiopathic central precocious puberty (ICPP) is a relatively common condition in preadolescent girls, and its pathogenesis remains to be uncovered. A variety of studies have highlighted the association of gut microbiota (GM) with endocrine diseases, such as obesity, which is commonly associated with ICPP. However, the relationship between GM and ICPP remains unexplored. Feces samples were collected from 25 girls with ICPP (ICPP group) and 23 healthy girls (Control group). We applied 16S rDNA sequencing to compare the GM between two groups. The ICPP group had higher GM diversity and was enriched for several GM species, including Ruminococcus gnavus, Ruminococcus callidus, Ruminococcus bromii, Roseburia inulinivorans, Coprococcus eutactus, Clostridium leptum, and Clostridium lactatifermentans, which are known to be associated with obesity and are related to the production of short-chain fatty acids. Additionally, 36 candidate GM biomarkers for patients with ICPP screening were identified with high accuracy (AUC = 0.95, 95% CI 0.88 to 1). We observed that the GM of the ICPP group was enriched for the microbial functions of cell motility, signal transduction, and environmental adaptation. Positive correlations were also detected between Fusobacterium and follicle-stimulating hormone, and Gemmiger and luteinizing hormone. This study documents relationships between GM and ICPP, and the implication of these findings remains to be determined.

Abstract Background Protein kinase N2 (PKN2) is a PKC-related serine/threonine-protein kinase. PKN2 is required for tumor cell migration, invasion and apoptosis. However, the functional role of PKN2 in regulating tumor associated macrophages (TAMs) polarization in colon cancer has never been reported. Methods PKN2 expression in human colon cancer tissues was examined with immunohistochemistry (IHC). M1/M2 macrophage signatures were evaluated by RT-PCR, IHC and flow cytometry. The effects of PKN2 on tumor growth and TAM polarization were investigated both in vitro and in vivo. PKN2 targeted cytokines/pathway were analyzed by gene expression analysis and further confirmed by PCR, luciferase assay or western blot. Correlations between PKN2 and transcriptional factors for IL4 and IL10 were confirmed by ChIP-qPCR. The catalytic activities of PKN2 and DUSP6 were determined by kinase activity assay. Interactions between PKN2 and DUSP6 were confirmed by Co-IP. Results The expression of PKN2 in colon cancer cells predicted a favorable prognosis and was associated with low M2 macrophage content in human colon cancer tissues. PKN2 inhibited tumor growth in mice xenograft model and inhibited M2 phenotype polarization both in vitro and in vivo. Mechanistically, PKN2 suppresses the expression of IL4 and IL10 from colon cancer cells by inhibiting Erk1/2 phosphorylation, which is required for phosphorylation and binding of CREB and Elk-1 to the promoters of IL4 and IL10. DUSP6, which is phosphorylated and activated through direct association with PKN2, suppresses Erk1/2 activation. Conclusions The expression of PKN2 in colon cancer cells suppresses tumor associated M2 macrophage polarization and tumor growth. Targeting PKN2 signaling pathway may provide a potential therapeutic strategy for colon cancer.

Abstract Lactose is the main carbohydrate in human and mammalian milk. Lactose requires enzymatic hydrolysis by lactase into D-glucose and D-galactose before it can be absorbed. Term infants express sufficient lactase to digest about one liter of breast milk daily. Physiological lactose malabsorption in infancy confers beneficial prebiotic effects, including the establishment of Bifidobacterium-rich fecal microbiota. In many populations, lactase levels decline after weaning (lactase non-persistence; LNP). LNP affects about 70% of the world’s population and is the physiological basis for primary lactose intolerance (LI). Persistence of lactase beyond infancy is linked to several single nucleotide polymorphisms in the lactase gene promoter region on chromosome 2. Primary LI generally does not manifest clinically before 5 years of age. LI in young children is typically caused by underlying gut conditions, such as viral gastroenteritis, giardiasis, cow’s milk enteropathy, celiac disease or Crohn’s disease. Therefore, LI in childhood is mostly transient and improves with resolution of the underlying pathology. There is ongoing confusion between LI and cow’s milk allergy (CMA) which still leads to misdiagnosis and inappropriate dietary management. In addition, perceived LI may cause unnecessary milk restriction and adverse nutritional outcomes. The treatment of LI involves the reduction, but not complete elimination, of lactose-containing foods. By contrast, breastfed infants with suspected CMA should undergo a trial of a strict cow’s milk protein-free maternal elimination diet. If the infant is not breastfed, an extensively hydrolyzed or amino acid-based formula and strict cow’s milk avoidance are the standard treatment for CMA. The majority of infants with CMA can tolerate lactose, except when an enteropathy with secondary lactase deficiency is present.

Abstract Elevated levels of Creatine Kinase-MB (CK-MB) Isoenzyme are a common phenomenon among rotavirus (RV) diarrhea. However, few studies have addressed this issue using large sample size. In current study, 1,118 children (age

Abstract HCV infection can decrease NAD+/NADH ratio, which could convert lipid metabolism to favor HCV replication. In hepatocytes, quinolinate phosphoribosyl transferase (QPRT) catabolizes quinolinic acid (QA) to nicotinic acid mononucleotide (NAMN) for de novo NAD synthesis. However, whether and how HCV modulates QPRT hence the lipogenesis is unknown. In this work, we found QPRT was reduced significantly in livers of patients or humanized C/OTg mice with persistent HCV infection. Mechanistic studies indicated that HCV NS3/4A promoted proteasomal degradation of QPRT through Smurf2, an E3 ubiquitin-protein ligase, in Huh7.5.1 cells. Furthermore, QPRT enzymatic activity involved in suppression of HCV replication in cells. Activation of QPRT with clofibrate (CLO) or addition of QPRT catabolite NAD both inhibited HCV replication in cells, probably through NAD+-dependent Sirt1 inhibition of cellular lipogenesis. More importantly, administration of CLO, a hypolipidemic drug used in clinics, could significantly reduce the viral load in HCV infected C/OTg mice. Take together, these results suggested that HCV infection triggered proteasomal degradation of QPRT and consequently reduced de novo NAD synthesis and lipogenesis, in favor of HCV replication. Hepatic QPRT thus likely served as a cellular factor that dampened productive HCV replication.

Zika virus (ZIKV) is a newly emerging flavivirus that broadly exhibits in various bodily tissues and fluids, especially in the brain, and ZIKV infection often causes microcephaly. Previous studies have been reported that ZIKV can infect renal cells and can be detected in the urine samples of infected individuals. However, whether ZIKV infection causes renal diseases and its pathogenic mechanisms remains unknown. Here, we identified that ZIKV infection resulted in acute kidney injury (AKI) in both newborn and adult mouse models by increasing the levels of AKI-related biomarkers [e.g., serum creatinine (Scr), kidney injury molecular−1 (Kim-1), and neutrophil gelatinase-associated lipocalin (NGAL)]. ZIKV infection triggered the inflammatory response and renal cell injury by activating Nod-like receptor 3 (NLRP3) inflammasome and secreting interleukin-1β (IL-1β). IL-1β inhibited aquaporins expression and led to water re-absorption disorder. Furthermore, ZIKV infection induced a decreased expression of B-cell lymphoma-2 (Bcl-2) in the kidney. Overexpression of Bcl-2 attenuated ZIKV-induced NLRP3 inflammasome activation in renal cells and down-regulated PARP/caspase-3-mediated renal apoptosis. Overall, our findings demonstrated that ZIKV infection induced AKI by activating NLRP3 inflammasome and apoptosis through suppressing Bcl-2 expression, which provided potential therapeutic targets for ZIKV-associated renal diseases.

Objective. HMGCS2 is the rate-limiting enzyme of ketogenesis, which is vital for tumor initiation or metastasis. The aim of this study is to determine the relationship between HMGCS2 and tumor angiogenesis. Materials and Methods. The study consisted of 100 cases with colorectal cancer and healthy control, the expression of HMGCS2 and the microvessel density (MVD) (marker: CD31) were analyzed by immunohistochemistry and tube formation, and the centration of β-hydroxybutyrate in serum was assessed by biochemical analysis. Results. The results showed that HMGCS2 expression is significantly reduced in colorectal cancer compared with healthy control, which is inversely correlated with MVD in colorectal cancer by IHC analysis. What is more, knockdown HMGCS2 expression in HT-29 cells significantly contributed endothelial cell tube formation. Conclusion. These findings implying HMGCS2 may have a negative regulation of tumor angiogenesis and provide an approach to inhibit tumor angiogenesis.

HSV-2 infection-induced CXCR3 ligands are important for the recruitment of virus-specific CD8+ T cells, but their impact on CD4+ T cell trafficking remains to be further determined. Given that recruitment of CD4+ T cells to infection areas may be one of the mechanisms that account for HSV-2 infection-mediated enhancement of HIV-1 sexual transmission, here we investigated the functionality of HSV-2 infection-induced CXCR3 ligands CXCL9, CXCL10, and CXCL11 in vivo and in vitro, and determined the viral components responsive for such induction and the underlying mechanisms. We first found that the expression of CXCR3 ligands CXCL9, CXCL10, and CXCL11 was increased in mice following vaginal challenge with HSV-2, while CXCL9 played a predominant role in the recruitment of CD4+ T cells to the vaginal foci of infected mice. HSV-2 infection also induced the production of CXCL9, CXCL10, and CXCL11 in human cervical epithelial cells. Of note, although HSV-2 induced the expression of all the three CXCR3 ligands, the induced CXCL9 appeared to play a predominant role in promoting CD4+ T cell migration, reflecting that the concentrations of CXCL10 and CXCL11 required for CD4+ T cell migration are higher than that of CXCL9. We further revealed that, ICP4, an immediate-early protein of HSV-2, is crucial in promoting CXCR3 ligand expression through the activation of p38 MAPK pathway. Mechanistically, ICP4 binds to corresponding promoters of CXCR3 ligands via interacting with the TATA binding protein (TBP), resulting in the transcriptional activation of the corresponding promoters. Taken together, our study highlights HSV-2 ICP4 as a vital viral protein in promoting CXCR3 ligand expression and CXCL9 as the key induced chemokine in mediating CD4+ T cell migration. Findings in this study have shed light on HSV-2 induced leukocyte recruitment which may be important for understanding HSV-2 infection-enhanced HIV-1 sexual transmission and the development of intervention strategies.

The prevalent Staphylococcus aureus clones and antibiotic susceptibility profiles are known to change dynamically and geographically; however, recent S. aureus strains causing infections in women and children in China have not been characterized. In this study, we analyzed the molecular epidemiology and antimicrobial resistance of S. aureus isolated from patients in four centers for women and children in Guangzhou, China. In total, 131 S. aureus isolates (100 from children and 31 from women) were analyzed by spa typing, multi-locus sequence typing, virulence gene and antimicrobial resistance profiling, staphylococcal chromosomal cassette mec typing, and mutation analyses of rpoB. A total of 58 spa types, 27 sequence types (STs), and 10 clonal complexes (CCs) were identified. While CC59 (ST59-IV, 48.8%; ST338-III, 35.7%) and CC45 (ST45-IV, 100%) were the major clones (84.4%) among MRSA isolates, CC5 (ST188, 24.3%; ST1, 21.6%) and CC398 (ST398, 70%) were the major ones (70.1%) among MSSA isolates. ST338-MRSA-III mostly found in pus but hardly in respiratory tract samples while ST45-MRSA-IV was on the opposite, even though they both found in blood and cerebrospinal fluid sample frequently. Staphylococcal enterotoxin genes seb-seq-sek were strongly associated with ST59 and ST338, while sec was associated with ST45, ST121, ST22, and ST30. All ST338, ST1232, and SCCmec III isolates carried lukF/S-PV genes. A total of 80% of ST338 isolates were resistant to erythromycin, clindamycin, and tetracycline. All ST45 isolates exhibited intermediate or complete resistance to rifampicin. In total, 481 HIS/ASN mutations in rpoB were found in rifampicin-resistant or intermediate-resistant isolates. ST338-III and ST45-IV emerged as two of three major clones in MRSA isolates from women and children in Guangzhou, China, though ST59-MRSA-IV remained the most prevalent MRSA clone. Clonal distribution of S. aureus varied, depending on the specimen source. Virulence genes and antibiograms were closely associated with the clonal lineage. These results clarified the molecular epidemiology of S. aureus from women and children in Guangzhou, China, and provide critical information for the control and treatment of S. aureus infections.

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus that can potentially threaten South China. A Chinese family of four returning from Venezuela to China was found to be positive for ZIKV when the youngest son’s fever was first detected at an airport immigration inspection. They were isolated temporarily in a local hospital in Enping city, Guangdong province, where their clinical data were recorded and urine and saliva were collected to isolate ZIKV and to obtain viral sequences. All of them except the mother presented mild symptoms of rash and fever. Envelope gene sequences from the father, daughter and son were completely identical. Phylogenetic analysis demonstrated that this strain is similar to several imported strains reported in recent months, which are all clustered into a group isolated from 2015 ZIKA outbreaks in Brazil. Together with the climatic features in Venezuela, New York and Guangdong in February, it can be concluded that our subjects are imported cases from Venezuela. With the same viral sequence being shared between family members, neither direct human-to-human nor vector transmission can be ruled out in this study, but the former seems more likely. Although our subjects had mild illness, epidemiologists and public health officials should be aware of the risk of further expansion of ZIKV transmission by local competent vectors.

How T cells differentiate in the neonate may critically determine the ability of the infant to cope with infections, respond to vaccines and avert allergies. Previously, we found that naïve cord blood CD4+ T cells differentiated toward an IL-4-expressing phenotype when activated in the presence of TGF-β and monocyte-derived inflammatory cytokines, the latter are more highly secreted by infants who developed food allergy. Here, we show that in the absence of IL-2 or IL-12, naïve cord blood CD8+ T cells have a natural propensity to differentiate into IL-4-producing non-classic TC2 cells when they are activated alone, or in the presence of TGF-β and/or inflammatory cytokines. Mechanistically, non-classic TC2 development is associated with decreased expression of IL-2 receptor alpha (CD25) and glycolysis, and increased fatty acid metabolism and caspase-dependent cell death. Consequently, the short chain fatty acid, sodium propionate (NaPo), enhanced IL-4 expression, but exogenous IL-2 or pan-caspase inhibition prevented IL-4 expression. In children with endoscopically and histologically confirmed non-inflammatory bowel disease and non-infectious pediatric idiopathic colitis, the presence of TGF-β, NaPo, and IL-1β or TNF-α promoted TC2 differentiation in vitro. In vivo, colonic mucosa of children with colitis had significantly increased expression of IL-4 in CD8+ T cells compared with controls. In addition, activated caspase-3 and IL-4 were co-expressed in CD8+ T cells in the colonic mucosa of children with colitis. Thus, in the context of colonic inflammation and limited IL-2 signaling, CD8+ T cells differentiate into non-classic TC2 that may contribute to the pathology of inflammatory/allergic diseases in children.

Background. Nontyphoidal Salmonella infection is a common cause for acute bacterial gastroenteritis in children in China. There have been no reports of the prevalence of lactose intolerance or food allergies in children with nontyphoidal Salmonella infection. The aim of this study was to characterize nontyphoidal Salmonella gastroenteritis in a tertiary children’s hospital and evaluate clinical presentation, lactose intolerance, and food allergies in children with prolonged nontyphoidal Salmonella gastroenteritis. Methods. A retrospective case-series analysis was carried out in a tertiary children’s hospital in Guangzhou, China. We included all infants and children who were diagnosed with nontyphoidal Salmonella gastroenteritis between 1 January 2014 and 31 December 2016. Patients’ clinical features, feeding patterns, laboratory tests, and treatment outcomes were reviewed. Results. A total of 142 infants and children were diagnosed with nontyphoidal Salmonella gastroenteritis. 52.1% of cases occurred in infants ≤ 12 months of age and the majority (89.4%) in children younger than 3 years old. The most common symptoms were diarrhea (100%), fever (62%), and vomiting (18.3%). Salmonella Typhimurium was the predominant serotype, accounting for 82.4%. 91.5% of patients were treated with antibiotics. Forty-one (28.9%) and 9 (6.3%) children improved with a lactose-free diet and hypoallergenic formula, respectively, when diarrhea persisted for more than a week. Conclusions. Salmonella Typhimurium was the predominant serotype. Most patients with nontyphoidal Salmonella gastroenteritis were younger than 3 years old. Lactose intolerance occurred frequently in children with nontyphoidal Salmonella gastroenteritis and dietary modification should be considered when diarrhea is persistent and prolonged.