• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1413-1425
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• 2018

Shiga toxins (Stxs) are the main virulence factors expressed by the pathogenic Stx-producing bacteria, namely, Shigella dysenteriae serotype 1 and certain Escherichia coli strains. These bacteria cause widespread outbreaks of bloody diarrhea (hemorrhagic colitis) that in severe cases can progress to life-threatening systemic complications, including hemolytic uremic syndrome (HUS) characterized by the acute onset of microangiopathic hemolytic anemia and kidney dysfunction. Shiga toxicosis has a distinct pathogenesis and animal models of Stx-associated HUS have allowed us to investigate this. Since these models will also be useful for developing effective countermeasures to Stx-associated HUS, it is important to have clinically relevant animal models of this disease. Multiple studies over the last few decades have shown that mice injected with purified Stxs develop some of the pathophysiological features seen in HUS patients infected with the Stx-producing bacteria. These features are also efficiently recapitulated in a non-human primate model (baboons). In addition, rats, calves, chicks, piglets, and rabbits have been used as models to study symptoms of HUS that are characteristic of each animal. These models have been very useful for testing hypotheses about how Stx induces HUS and its neurological sequelae. In this review, we describe in detail the current knowledge about the most well-studied in vivo models of Stx-induced HUS; namely, those in mice, piglets, non-human primates, and rabbits. The aim of this review is to show how each human clinical outcome-mimicking animal model can serve as an experimental tool to promote our understanding of Stx-induced pathogenesis.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4135-4139
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• 2013

Inflammation is potential risk factor of various human malignancies. Inflammatory bowel syndromes such as ulcerative colitis are well known as risk factors for colon cancer. Here, we examined enhancing effects of dextran sulfate sodium (DSS)-associated inflammation on X-irradiation induced colonic tumorigenesis in Min and wild-type (WT) mice. Animals were X-irradiated at 1.5 Gy at 5 weeks of age (at 0 experimental week) and 2% DSS in drinking water was administered at 5 or 11 experimental weeks. Mice were sacrificed at 16 weeks and incidence and multiplicity of colonic tumors were assessed. Incidence of colonic tumors in Min mouse was increased from 33.3% to 100% (p<0.05) with X-irradiation alone, whereas no tumors were developed in WT mice. In DSS-treated Min mice, X-irradiation increased the number of colonic tumors. Total number of colonic tumors was increased 1.57 times to $30.7{\pm}3.83$ tumors/mouse with X-irradiation+DSS at 5 weeks comapared to $19.6{\pm}2.9$ in corresponding DSS alone group (p<0.05). When the duration of inflammation was compared, longer period of DSS effect promoted more colonic tumorigenesis. Collectively, we conclude that X-irradiation and DSS-induced inflammation act synergistically for colonic tumorigenesis.

• Clinical and Experimental Pediatrics
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• v.57 no.2
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• pp.96-99
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• 2014

Hemolytic uremic syndrome (HUS) is one of the most common causes of acute renal failure in childhood and is primarily diagnosed in up to 4.5% of children who undergo chronic renal replacement therapy. Escherichia coli serotype O157:H7 is the predominant bacterial strain identified in patients with HUS; more than 100 types of Shiga toxin-producing enterohemorrhagic E. coli (EHEC) subtypes have also been isolated. The typical HUS manifestations are microangiopathic hemolytic anemia, thrombocytopenia, and renal insufficiency. In typical HUS cases, more serious EHEC manifestations include severe hemorrhagic colitis, bowel necrosis and perforation, rectal prolapse, peritonitis, and intussusceptions. Colonic perforation, which has an incidence of 1%-2%, can be a fatal complication. In this study, we report a typical Shiga toxin-associated HUS case complicated by small intestinal perforation with refractory peritonitis that was possibly because of ischemic enteritis. Although the degree of renal damage is the main concern in HUS, extrarenal complications should also be considered in severe cases, as presented in our case.

• Biomedical Science Letters
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• v.15 no.3
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• pp.261-263
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• 2009

Methylprednisolone is a synthetic glucocorticoid which is usually taken intravenously for many neurosurgical diseases which cause edema including brain tumor, and trauma including spinal cord injury. Methylprednisolone reduces swelling and decreases the body's immune response. It is also used to treat many immune and allergic disorders, such as arthritis, lupus, psoriasis, asthma, ulcerative colitis, and Crohn's disease. To identify genes expressed during methylprednisolone treatment against neurons of rats (PC12 cells), DNA microarray method was used. We have isolated 2 gene groups (up- or down-regulated genes) which are methylprednisolone differentially expressed in neurons. Lipocalin 3 is the gene most significantly increased among 772 up-regulated genes (more than 2 fold over-expression) and Aristaless 3 is the gene most dramatically decreased among 959 down-regulated genes (more than 2 fold down-expression). The gene increased expression of Fgb, Thbd, Cfi, F3, Kngl, Serpinel, C3, Tnfrsf4 and Il8rb are involved stress-response gene, and Nfkbia, Casp7, Pik3rl, I11b, Unc5a, Tgfb2, Kitl and Fgf15 are strongly associated with development. Cell cycle associated genes (Mcm6, Ccnb2, Plk1, Ccnd1, E2f1, Cdc2a, Tgfa, Dusp6, Id3) and cell proliferation associated genes (Ccl2, Tnfsf13, Csf2, Kit, Pim1, Nr3c1, Chrm4, Fosl1, Spp1) are down-regulated more than 2 times by methylprednisolone treatment. Among the genes described above, 4 up-regulated genes are confirmed those expression by RT-PCR. We found that methylprednisolone is related to expression of many genes associated with stress response, development, cell cycle, and cell proliferation by DNA microarray analysis. However, We think further experimental molecular studies will be needed to figure out the exact biological function of various genes described above and the physiological change of neuronal cells by methylprednisolone. The resulting data will give the one of the good clues for understanding of methylprednisolone under molecular level in the neurons.

• Clinical and Experimental Pediatrics
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• v.50 no.10
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• pp.931-937
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• 2007

The hemolytic uremic syndrome (HUS) is a rare disease of microangiopathic hemolytic anemia, low platelet count and renal impairment. HUS usually occurs in young children after hemorrhagic colitis by shigatoxin-producing enterohemorrhagic E. coli (D+HUS). HUS is the most common cause of acute renal failure in infants and young children, and is a substantial cause of acute mortality and morbidity; however, renal function recovers in most of them. About 10% of children with HUS do not reveal preceding diarrheal illness, and is referred to as D- HUS or atypical HUS. Atypical HUS comprises a heterogeneous group of thrombomicroangiopathy (TMA) triggered by non-enteric infection, virus, drug, malignancies, transplantation, and other underlying medical condition. Emerging data indicate dysregulation of alternative complement pathway in atypical HUS, and genetic analyses have identified mutations of several regulatory genes; i.e. the fluid phase complement regulator Factor H (CFH), the integral membrane regulator membrane cofactor protein (MCP; CD46) and the serine protease Factor I (IF). The uncontrolled activation of the complement alternative pathway results in the excessive consumption of C3. Plasma exchange or plasma infusion is recommended for treatment of, and has dropped the mortality rate. However, overall prognosis is poor, and many patients succumb to end-stage renal disease. Clinical presentations, response to plasma therapy, and outcome after renal transplantation are influenced by the genotype of the complement regulators. Thrombotic thrombocytopenic purpura (TTP), another type of TMA, occurs mainly in adults as an acquired disease accompanied by fever, neurologic deficits and renal abnormalities. However, less frequent cases of congenital or hereditary TTP associated with ADAMTS-13 (a disintegrin and metalloprotease, with thrombospondin 1-like domains 13) gene mutations have been reported, also. Recent advances in molecular genetics better allow various HUS to be distinguished on the basis of their pathogenesis. The genetic analysis of HUS is important in defining the underlying etiology, predicting the genotype-related outcome and optimizing the management of the patients.

• BMB Reports
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• v.54 no.10
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• pp.534-539
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• 2021

IL-10⁺ regulatory B (Breg) cells play a vital role in regulating the immune responses in experimental autoimmune encephalomyelitis, colitis, and contact hypersensitivity (CHS). Several stimulants such as lipopolysaccharide (LPS), CD40 ligand, and IL-21 spur the activation and maturation of IL-10⁺ Breg cells, while the epigenetic mechanism for the IL-10 expression remains largely unknown. It is well accepted that the histone acetylation/deacetylation is an important mechanism that regulates the expression of IL-10. We found that entinostat, an HDAC inhibitor, stimulated the induction of IL-10⁺ Breg cells by LPS in vitro and the formation of IL-10⁺ Breg cells to suppress CHS in vivo. We further demonstrated that entinostat inhibited HDAC1 from binding to the proximal region of the IL-10 expression promoter in splenic B cells, followed by an increase in the binding of NF-κB p65, eventually enhancing the expression of IL-10 in Breg cells.

• Clinical and Experimental Vaccine Research
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• v.13 no.1
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• pp.42-53
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• 2024

Purpose: Conduct a systematic review of case reports and case series regarding the development of acute abdomen following coronavirus disease 2019 (COVID-19) vaccination, to describe the possible association and the clinical and demographic characteristics in detail. Materials and Methods: This study included case report studies and case series that focused on the development of acute abdomen following COVID-19 vaccination. Systematic review studies, literature, letters to the editor, brief comments, and so forth were excluded. PubMed, Scopus, EMBASE, and Web of Science databases were searched until June 15, 2023. The Joanna Briggs Institute tool was used to assess the risk of bias and the quality of the study. Descriptive data were presented as frequency, median, mean, and standard deviation. Results: Seventeen clinical case studies were identified, evaluating 17 patients with acute abdomen associated with COVID-19 vaccination, which included acute appendicitis (n=3), acute pancreatitis (n=9), diverticulitis (n=1), cholecystitis (n=2), and colitis (n=2). The COVID-19 vaccine most commonly linked to acute abdomen was Pfizer-BioNTech (messenger RNA), accounting for 64.71% of cases. Acute abdomen predominantly occurred after the first vaccine dose (52.94%). All patients responded objectively to medical (88.34%) and surgical (11.76%) treatment and were discharged within a few weeks. No cases of death were reported. Conclusion: Acute abdomen is a rare complication of great interest in the medical and surgical practice of COVID-19 vaccination. Our study is based on a small sample of patients; therefore, it is recommended to conduct future observational studies to fully elucidate the underlying mechanisms of this association.

• Clinical and Experimental Pediatrics
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• v.46 no.2
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• pp.143-153
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• 2003

Purpose : Infection with Shiga-like toxin (SLT)-producing Escherichia coli, an emerging human pathogen found particularly in young children under 5 years of age, causes a spectrum of illnesses with high morbidity and mortality, ranging from diarrhea to hemorrhagic colitis and hemolytic uremic syndrome. Host mediators play an important role in the pathogenesis of SLT-I toxicity. The experiments described here were designed to investigate the effect of SLT-I on TNF-${\alpha}$ production and to understand the effect of TNF-${\alpha}$ on GB3 expression. We also further examine the relationship between the Gb3 level and the differential susceptibility of cells to the cytotoxic action of SLT-I. Methods : The effect of purified SLT-1 from E. coli O157 : H7 (ATCC 43890) on tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) production in Raw264.7 cells was investigated. Many mediators regulate endothelial cell membrane expression of the glycolipid globotriaosyleramide (Gb3), which serves as the toxin receptor, suggesting that the host response to the toxin or other bacterial products may contribute to pathogenesis by regulating target cell sensitivity to the toxins. Therefore, the relationships between Gb3 expression and cytotoxicity against SLT-I on three types of cells were evaluated. Results : Detectable levels of TNF-${\alpha}$ were produced as early as six hours after induction and continued to increase during 48 hours by SLT-I. It was also found that Vero cells and dendritic cells (DC2.4 cells) expressed high levels of Gb3, 83% and 68%, respectively, and that Raw264.7 cells had a low level of Gb3 (29%) and appeared refractory to cytotoxicity against SLT-I. Vero cells and DC2.4 cells expressing high levels of Gb3 were highly susceptible to SLT-I. Furthermore, macrophages showed a resistance to SLT-I cytotoxicity, despite the fact that Gb3 expression was enhanced. Conclusion : These results strongly suggest that the expression of Gb3 is necessary but not sufficient to confer sensitivity of macrophages to SLT-I and further underpin the important role of SLT-I and its Gb3 receptors in the pathogenesis of E. coli O157 infection.

• Journal of Life Science
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• v.27 no.8
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• pp.873-878
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• 2017

We previously reported that NAD(P)H:quinone oxidoreductase 1 (NQO1)-knockout (KO) mice exhibited spontaneous inflammation in the gut. We also found that NQO1-KO mice showed highly increased inflammatory responses compared with NQO1-WT control mice when subjected to DSS-induced experimental colitis. In a Clostridium difficile toxin-induced mouse enteritis model, NQO1-KO mice were also sensitive compared with NQO1-WT mice. Moreover, numerous studies have shown that NQO1 is functionally associated with immune regulation. Here, we assessed whether NQO1 defects can alter macrophage activation. We found that peritoneal macrophages isolated from NQO1-KO mice produced more IL-6 and $TNF-{\alpha}$ than those isolated from NQO1-WT mice. Moreover, the dicumarol-induced inhibition of NQO1 significantly increased IL-6 and $TNF-{\alpha}$ production in peritoneal macrophages isolated from NQO1-WT mice, as well as in the cultured mouse macrophage cell line, RAW264.7. These results indicate that NQO1 may negatively regulate the activation of macrophages. Knockout or chemical inhibition of NQO1 markedly reduced the expression of $I{\kappa}B$ (inhibitor of $NF{\kappa}B$) in both mouse peritoneal macrophages and RAW264.7 cells. Finally, RAW264.7 cells treated with dicumarol exhibited morphological changes reflecting macrophage activation. Our results suggest that NQO1 may suppress the $NF{\kappa}B$ pathways in macrophages, thereby suppressing the activation of these cells. Thus, immunosuppressive activity may be among the many possible functions of NQO1.

• Clinical and Experimental Pediatrics
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• v.61 no.10
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• pp.327-331
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• 2018

Purpose: The incidence of inflammatory bowel disease (IBD) is rapidly increasing, and several reports have described the renal complications of IBD. We sought to evaluate the clinical manifestations of renal complications in children with IBD in order to enable early detection and prompt treatment of the complications. Methods: We retrospectively reviewed the medical records of 456 children and adolescents aged <20 years who had been diagnosed with IBD since 2000. We analyzed patient age, sex, medication use, IBD disease activity, and clinical manifestations of renal symptoms. Results: Our study comprising 456 children with IBD included 299 boys (65.6%) and 157 girls (34.4%). The study included 346 children with Crohn disease and 110 children with ulcerative colitis. The incidence of kidney-related symptoms was 14.7%, which was significantly higher than that in normal children. We observed 26 children (38.8%) with isolated hematuria, 30 children (44.8%) with isolated proteinuria, and 11 children (16.4%) with hematuria and concomitant proteinuria. A renal biopsy was performed in 7 children. Histopathological examination revealed immunoglobulin A nephropathy in 5 children (71.4%). All children presented with mild disease and well-controlled disease activity of IBD. Conclusion: Children with IBD are more likely to show kidney-related symptoms than healthy children and adolescents are. Therefore, regular screening of urine and evaluation of renal function in such children are necessary for early detection of renal complications.