Effect of Asiaticoside on Expression of Th17/Treg Cells in DBA/1 Mice with Collagen-Induced Arthritis / 中国实验方剂学杂志

ObjectiveTo observe the effect of asiaticoside （AC） on the expression of T helper 17 （Th17） cells and regulatory T （Treg） cells in DBA/1 mice with collagen-induced arthritis （CIA）. MethodMale SPF DBA/1 mice were randomized into six groups according to body weight： control group， CIA group， methotrexate group （MTX group， ip， 0.5 mg·kg-1）， and AC low-， medium-， and high-dose groups （ig， 5， 15， 45 mg·kg-1， respectively）. Modeling was performed in rats other than the control group. To be specific， they were immunized with bovine type Ⅱ collagen and complete Freund's adjuvant on the first day and with bovine type Ⅱ collagen and incomplete Freund's adjuvant on the 21st day. Administration began on the day of the second immunization， once a day for 28 days. On the 49th day， related tissues were collected. Then， hematoxylin-eosin （HE） staining was performed to observe the pathological changes of the joints. Immunohistochemical method was used to detect the expression of interleukin-17 （IL-17） and forkhead box protein-3 （FoxP3）， the markers of Th17 and Treg cells， respectively， immunofluorescence double staining the expression of IL-17 and FoxP3 in CD4+T cells of mouse joint tissue， and flow cytometry the proportions of Th17 and Treg cells in mouse lymph nodes. ResultCompared with the control group， CIA group demonstrated joint disorder， damage of articular cartilage and bone， severe bone erosion （P<0.01）， increase in stained CD4 and IL-17 and the integral absorbance （IA） （P<0.01）， decrease in stained FoxP3 and the IA （P<0.01）， rise of Th17/Treg ratio （P<0.01）， elevation of Th17 expression in mouse lymph nodes （P<0.01）， and reduction in Treg expression （P<0.01）. Compared with CIA group， MTX group and three AC groups showed normal joints， alleviated bone erosion and damage， intact and smooth joint surface， and decrease in stained IL-17 and IA （P<0.05， P<0.01）， and MTX group and AC medium-dose and high-dose groups registered decrease in stained CD4 and IA （P<0.01） and reduction in Th17/Treg ratio （P<0.05， P<0.01）. Moreover， AC medium-dose and high-dose groups showed rise in stained FoxP3 and IA （P<0.05， P<0.01）. In the lymph nodes of mice， decrease in expression of Th17 cells （P<0.05， P<0.01） and the increase in expression of Treg cells （P<0.05， P<0.01） were observed in all the three AC group. ConclusionAC can regulate Th17/Treg balance by inhibiting the expression of Th17 cells and promoting the expression of Treg cells in CIA mice.

A High-Tryptophan Diet Reduces Seizure-Induced Respiratory Arrest and Alters the Gut Microbiota in DBA/1 Mice.

Background and Aims: Central 5-hydroxytryptamine (5-HT) defects are responsible for the occurrence of sudden unexpected death in epilepsy (SUDEP). The DBA/1 mouse is an animal model of SUDEP since the mouse exhibits audiogenic seizure-induced respiratory arrest (S-IRA). The synthesis of central 5-HT is closely related to the gut microbiota. Moreover, emerging studies suggest a possible role for the microbiota in mitigating seizure likelihood. Based on this, we aimed to explore the effect of a high-tryptophan diet (HTD) on SUDEP as well as the synthesis and metabolism of central 5-HT. Furthermore, we investigated the involvement of the gut microbiota in this process. Methods: All DBA/1 mice were subjected to acoustic stimulation to induce seizures. Only those mice that exhibited S-IRA were randomly assigned to the normal diet (ND) group (n = 39) or HTD group (n = 53). After 1 month of dietary intervention, (1) S-IRA rates were evaluated, (2) the concentrations of 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the plasma and brain were determined by ultra-high-pressure liquid chromatography, and (3) the fecal flora biodiversity and species composition were analyzed by 16S rDNA microbiota profiling. Results: The S-IRA rate in DBA/1 mice was significantly reduced in the HTD group compared with that in the control group. HTD increased the levels of 5-HT and 5-HIAA in both the telencephalon and midbrain. HTD significantly elevated the species richness and diversity of the gut microbiota. Moreover, there was a significant difference in the gut microbiota composition between the two groups, and the intestinal flora was dominated by Proteobacteria and Actinobacteria after HTD. Conclusions: HTD is efficient in lowering S-IRA rates and elevating the central 5-HT level in DBA/1 mice. The gut microbiota was altered after HTD intervention. The significant increase in Proteobacteria and Actinobacteria may be related to the SUDEP-protective effect of HTD. Our findings shed light on a candidate choice of dietary prevention for SUDEP.

High humidity aggravates the severity of arthritis in collagen-induced arthritis mice by upregulating xylitol and L-pyroglutamic acid.

BACKGROUND: Humidity was an unfavorable factor for patients with rheumatoid arthritis (RA). RA disease activity was severe in high humidity conditions. However, there is no evidence to demonstrate the effects of humidity on arthritis in the animal experiments and explore its relevant mechanism. METHODS: Using the DBA/1 mice, this study addressed the effects of a high humidity (80 ± 5%) on arthritis in collagen-induced arthritis (CIA) mice. Then, this study used the gas chromatography-mass spectrometer (GC-MS) to explore alterations in serum metabolome caused by the high humidity. Furthermore, xylitol and L-pyroglutamic acid, which were both significantly upregulated by the high humidity, were selected to further study their effects on arthritis in the CIA mice. RESULTS: The high humidity (80 ± 5%) could aggravate arthritis variables including increasing arthritis score and swelling, serum autoantibodies (anti-COII and anti-CCP), and proinflammatory cytokines (IL-6, IL-17A, and G-CSF). In addition, the high humidity could cause significant alterations in serum metabolome in the CIA mice. Xylitol and L-pyroglutamic acid were the representative serum metabolites that were significantly upregulated by the high humidity. Further experiments demonstrated that the supplementation of 0.4 mg/mL xylitol in drinking water after inducing the CIA model and 2.0 mg/mL in drinking water before inducing the CIA model could both aggravate arthritis in the CIA mice. CONCLUSIONS: These data demonstrated that high humidity was not beneficial for arthritis development and its mechanism might be associated with xylitol and L-pyroglutamic acid.

Effect of Fangji Huangqitang on DBA/1 Mice Collagen Induced Arthritis and Synovial Angiogenesis / 中国实验方剂学杂志

Objective:To observe the effect of Fangji Huangqitang （FJHQT） on collagen induced arthritis （CIA） and synovial angiogenesis in DBA/1 mice. Method:DBA/1 mice were randomly divided into normal group， CIA group and FJHQT group. DBA/1 mice in CIA group and FJHQT group were immunized with bovine type Ⅱ collagen and complete Freund's adjuvant on the first day， and DBA/1 mice were immunized with bovine type Ⅱ collagen and incomplete Freund's adjuvant on the 21^st day to establish CIA model. On the day of the second immunization， the drug was given by gavage once a day for 28 days. On the 22^nd day， the arthritis score and other symptoms of CIA mice were observed. On the 49^th day， Hematoxylin eosin （HE） staining was carried out to observe the angiogenesis in the synovium of CIA mice， the expression of vascular endothelial cell marker platelet endothelial cell adhesion molecule-1 （CD31） and vascular endothelial growth factor （VEGF） in the synovium of CIA mice were detected. Immunofluorescence double staining was used to detect the mature and immature vessels in the synovium of CIA mice. And the microvascular growth of the rat thoracic aortic ring was induced by VEGF （20 μg·L^-1）. The effects of FJHQT （0.25， 0.5， 1 g·L^-1） at different concentrations were observed under microscope. Result:Compared with the normal group， the inflammation， joints， red and swelling of the inflammatory joints of the CIA group were significantly increased （<italic>P</italic><0.01）. The scores of clinical arthritis， the incidence rate， synovial inflammation and angiogenesis were significantly increased （<italic>P</italic><0.01）. The density of blood vessels， the positive expression of CD31 and VEGF， the number of immature vessels in synovial membrane were significantly increased （<italic>P</italic><0.01）. And compared with the CIA group， the inflammation， joint swelling， and malformation of the FJHQT group were significantly improved， the clinical arthritis score， incidence rate， synovial inflammation and angiogenesis were significantly reduced （<italic>P</italic><0.01）. The vascular density， the positive expression of CD31 and VEGF， and the number of immature blood vessels in synovial membrane were significantly increased （<italic>P</italic><0.01）. Compared with blank group， VEGF could significantly induce the growth of microvasculature in rat thoracic aortic ring （<italic>P</italic><0.01）. Compared with VEGF group， FJHQT（0.25， 0.5， 1 g·L^-1） could significantly inhibit the formation of microvasculature in rat thoracic aortic ring （<italic>P</italic><0.01）. Conclusion:FJHQT can effectively alleviate the clinical symptoms and condition of CIA mice， reduce the clinical arthritis score and incidence rate，and inhibit the synovial angiogenesis of CIA mice joints and VEGF induced microvascular formation in rat thoracic aortic rings.

Specific subcortical structures are activated during seizure-induced death in a model of sudden unexpected death in epilepsy (SUDEP): A manganese-enhanced magnetic resonance imaging study.

Sudden unexpected death in epilepsy (SUDEP) is a major concern for patients with epilepsy. In most witnessed cases of SUDEP generalized seizures and respiratory failure preceded death, and pre-mortem neuroimaging studies in SUDEP patients observed changes in specific subcortical structures. Our study examined the role of subcortical structures in the DBA/1 mouse model of SUDEP using manganese-enhanced magnetic resonance imaging (MEMRI). These mice exhibit acoustically-evoked generalized seizures leading to seizure-induced respiratory arrest (S-IRA) that results in sudden death unless resuscitation is rapidly instituted. MEMRI data in the DBA/1 mouse brain immediately after acoustically-induced S-IRA were compared to data in C57 (control) mice that were exposed to the same acoustic stimulus that did not trigger seizures. The animals were anesthetized and decapitated immediately after seizure in DBA/1 mice and after an equivalent time in control mice. Comparative T1 weighted MEMRI images were evaluated using a 14T MRI scanner and quantified. We observed significant increases in activity in DBA/1 mice as compared to controls at previously-implicated auditory (superior olivary complex) and sensorimotor-limbic [periaqueductal gray (PAG) and amygdala] networks and also in structures in the respiratory network. The activity at certain raphe nuclei was also increased, suggesting activation of serotonergic mechanisms. These data are consistent with previous findings that enhancing the action of serotonin prevents S-IRA in this SUDEP model. Increased activity in the PAG and the respiratory and raphe nuclei suggest that compensatory mechanisms for apnea may have been activated by S-IRA, but they were not sufficient to prevent death. The present findings indicate that changes induced by S-IRA in specific subcortical structures in DBA/1 mice are consistent with human SUDEP findings. Understanding the changes in brain activity during seizure-induced death in animals may lead to improved approaches directed at prevention of human SUDEP.

Immunization with mixed peptides derived from glucose-6-phosphate isomerase induces rheumatoid arthritis in DBA/1 mice / 中国病理生理杂志

[ ABSTRACT] AIM:To establish an animal model of rheumatoid arthritis ( RA) in DBA/1 mice induced by im-munodominant mixed peptides derived from glucose-6-phosphate isomerase (GPI).METHODS: The DBA/1 mice were immunized with emulsified mixed peptide fragments of hGPI 325-339+hGPI469-483 or single peptide hGPI325-339 in com-plete Freund′s adjuvant by subcutaneous injection to induce the model of RA .Body weight , ankle joint symptom scores , the pathological change of the ankle joint , the levels of CD4 +T cells in the spleen and peripheral blood , the proportion of iNKT cells in the peripheral blood , and the levels of TNF-αand IL-6 in serum were detected to evaluate and analyze the model.RESULTS:The hind paw of the model mice appeared red swelling on the 8th day, and then aggravated gradually to the limbs.The red swelling reached peak on the 14th day, and then relieved gradually .Inflammation response dominated by lymphocytes and monocytes was observed in the ankle joint .The inflammatory effect of mixed peptides was more obvious than that of the single one (P<0.05).Compared with control group and the mice treated with single peptide , the weight gain was slow, the amount of CD4 +T cells in the peripheral blood and spleen were increased , the proportion of peripheral iNKT cells in the inflammatory peak was decreased (P<0.05), and the serum level of TNF-αwas increased significantly ( P<0.05) in the mice treated with mixed peptide fragments .CONCLUSION: The immunological characteristics of RA model induced by mixed GPI peptides in DBA/1 mice is closer to that in RA patients , especially in the immunopathology of iNKT cells.Therefore, this model can be used as a new tool for studying the mechanism and immunological intervention of RA.

Eye-mediated immune tolerance to Type II collagen in arthritis-prone strains of mice.

Type II collagen (CII) is a cartilage structural protein that plays important roles in joint function, arthritis and ageing. In studying the ability of CII to induce eye-mediated specific immune tolerance, we have recently proven that CII is capable of inducing anterior chamber-associated immune deviation (ACAID) in Balb/c mice. Here, we study the ability of CII to induce eye-mediated immune tolerance in strains of mice that are prone to the induction of rheumatoid arthritis. Thus, we hypothesized that CII induces ACAID in DBA/1 mice and in C57BL/6 mice through the AC route (direct injection) or the intravenous route (adoptive transfer of in vitro-generated CII-specific ACAID macrophages or of CII-specific in vitro-generated T regulatory cells). Specific immune tolerance induction was assessed using both delayed-type hypersensitivity (DTH) and local adoptive transfer (LAT) assays. Results indicated the ability of CII to generate CII-specific ACAID-mediated immune tolerance in vivo and in vitro in both DBA/1 mice and C57BL/6 mice. These findings could be beneficial in studies of immune tolerance induction using CII.