Effect of pachyman polysaccharides on Th17/Treg balance in systemic lupus erythematosus patients

AIM: To investigate the immunomodulatory effect of pachyman polysaccharides (PPS) on T helper 17 cell (Th17)/regulatory T cell (Treg) balance in the peripheral blood of systemic lupus erythematosus (SLE) patients. METHODS: The CD4⁺ T cells were isolated from the peripheral blood samples obtained from 45 SLE patients and 35 healthy controls enrolled in our study using magnetic bead separation method. The proportions of Th17 and Treg cells were measured by flow cytometry. The CD4⁺ T cells from SLE patients and healthy controls were treated with PPS. The cytoto-xicity of PPS was evaluated by detecting cell viability with MTT assay. The contents of interleukin-17 (IL-17), IL-6, IL-10 and transforming growth factor-β (TGF-β) were measured by ELISA. The expression of retinoid-related orphan receptor γt (RORγt) and forkhead box protein P3 (Foxp3) at mRNA and protein levels was determined by RT-qPCR and Western blot, respectively. RESULTS: The Th17 cells were significantly elevated, while Treg cells were obviously decreased in the SLE patients compared with the healthy control group (P<0.05). Compare with control group, the contents of IL-17 and IL-6 were decreased, while the contents of IL-10 and TGF-β were increased (P<0.05). The expression of RORγt at mRNA and protein levels was down-regulated and the expression of Foxp3 was up-regulated (P<0.05). The ratio of Th17/Treg was decreased in 100 μg/L nontoxic PPS-treated CD4⁺ T cells isolated from the SLE patients (P<0.05). CONCLUSION: PPS treatment inhibits Th17 cells and elevates Treg cells in the CD4⁺ T cells isolated from SLE patients, which may have a therapeutic effect on SLE patients.     

Pathogenesis,prevention and treatment of COVID-19 based on Th17/Treg immune imbalance

The extremely severe epidemic situation of coronavirus disease 2019 （COVID-19） outbreak around the world with high infectiousness and rapid spread has become a public health emergency of international concern. The disease is caused by severe acute respiratory syndrome coronavirus 2 （SARS-CoV-2）, and cytokine storm is an important pathological manifestation. Related studies have shown that cytokine storm and dysregulation of host immune responses characterized by lymphopenia are important mechanisms for the pathogenesis of severe COVID-19. The immune response disorder of COVID-19 is closely related to T helper 17 cell/regulatory T cell （Th17/Treg） immune imbalance. SARS-CoV-2 infection leads to excessive activation of lung immune cells, forming a cytokine storm dominated by interleukin-6 （IL-6）. Then, the Th17/Treg immune balance is broken, forming a vicious circle, which eventually promotes the rapid aggravation of the disease. Finally, COVID-19 progresses into acute respiratory distress syndrome, and even respiratory failure until death. Therefore, it is more important to discuss the prevention and treatment of COVID-19 from the perspective of immune imbalance. On the view of treatment, before effective antiviral drugs and vaccines are successfully developed, we should pay attention to immune regulation for severe and critically ill patients. Treatments with inflammatory factor blockers, glucocorticoids, recovered plasma and traditional Chinese medicine have certain immunomodulatory effect. This article discusses the pathogenesis of COVID-19 based on Th17/Treg immune imbalance, and elaborates on immunomodulatory therapy, aiming to provide reference for the prevention and treatment of COVID-19 and drug development.     

中国园艺学会2012年学术年会暨庆祝《园艺学报》创刊50周年—园艺学进展论坛征文通知

"中国园艺学会2012年学术年会暨庆祝《园艺学报》创刊50周年—园艺学进展论坛"将于2012年10月在西安举行,即日起征集:①研究论文摘要,②有关园艺学进展的综述文章。经审查合格的摘要和综述将分别收入"中国园艺学会2012年学术年会论文摘要集"和"庆祝《园艺学报》创刊50周年—园艺学进展论坛专辑",并于会前以     

Bone marrow-derived mesenchymal stem cells regulate the function of Th17/ Treg in peripheral blood of severe asthmatic children

AIM：To investigate the regulatory function of bone marrow-derived mesenchymal stem cells (MSCs) on T helper 17 cells (Th17) and regulatory T cells (Treg) in peripheral blood of severe asthmatic children. METHODS：MSCs were isolated, cultured and identified in vitro. MSCs digested with mitomycin were cocultured with T lymphocytes (TLC) at different ratios (1∶1, 1∶2, 1∶10 and 1∶20) from severe asthmatic children for 72 h. The proliferation of TLC was measured by CCK-8 method. In the coculture system of the 1∶2 ratio and the single TLC system, the supernatant levels of interleukin-17 (IL-17) and transforming growth factor-β (TGF-β) were measured by ELISA. The mRNA expression of retinoic acid-related orphan nuclear receptor C (RORC) and forkhead box protein 3 (Foxp3) in TLC was detected by qRT-PCR. RESULTS：After cocultured with MSCs, the proliferation of TLC decreased significantly in a dose-dependent manner (P<0.05). It also showed decreases in IL-17 (3 799±441 vs 4 890 ±373, P<0.05) and RORC mRNA level (1.21±0.14 vs 3.85±0.48, P<0.05), while an increase in TGF-β level (209±32 vs 117±26, P<0.05) was observed. No influence on the mRNA expression of Foxp3 was found (P>0.05). CONCLUSION：MSCs suppresses Th17 polarization of naive peripheral blood CD4+ T cells and matures Th17 cells secreting IL-17, which may effectively revise Th17/Treg imbalance of asthma.     

Protective effects of DAPT on rat model with atherosclerotic ischemic brain stroke by blocking Notch pathway

AIM: To investigate the protective effects of DAPT on rat model with atherosclerotic (AS) ischemic brain stroke by blocking Notch pathway. METHODS: SD rats (n=24) were randomly divided into control group and model group, and the rats in model group were fed high-fat diet for 6 weeks to establish the AS model. The AS rats were randomly divided into 3 groups (n=6 in each group):AS-sham group, AS rats with ischemia (AS-ishemia) group, and DAPT administration (AS-ishemia-DAPT) group. The histopathological changes of carotid aorta were observed by HE staining. The serum levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured by automatic biochemical analyzer. The levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were detected by ELISA. The protein levels of Notch1 and Hes1 in rat artery, and nuclear factor-κB (NF-κB) and Toll-like receptor 4 (TLR4) in rat brain were determined by Western blot. RESULTS: Notch signaling pathway inhibitor DAPT significantly reduced intimal thickening, vascular stenosis and the formation of AS plaque. Compared with AS-ischemia group, the serum levels of lipids and inflammatory factors were decreased significantly in AS-ischemia-DAPT group, and the protein levels of Notch1 and Hes1 in the rat carotid artery and NF-κB and TLR4 protein expression in rat brain were also decreased significantly (P<0.05). CONCLUSION: Blocking Notch pathway by DAPT not only improves the blood lipid levels, but also inhibits the serum inflammatory cytokine release and NF-κB/TLR4 pathway activation.     

Relationship between Th17/Treg cells and microinflammatory state in uremia patients

AIM: To investigate the changes of T-helper 17(Th17) and regulatory T (Treg) cells in uremic patients by determining the mRNA expression of retinoid-related orphan receptor γt (RORγt)and forkhead box P3 protein (Foxp3), and to observe the correlation with the status of microinflammation. METHODS: Thirty uremia patients enrolled in our blood purification center during July 2010 to July 2011 were selected in the study and divided into maintaining hemodialysis (MHD) group (n=20) and chronic kidney disease (CKD) group (n=10). Twenty matched healthy volunteers served as controls. Serum samples were collected from all the patients in the morning. The mRNA expression of RORγt and Foxp3,plasma interleukin (IL)-6, IL-10 and IL-17 in these patients were measured by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The content of high-sensitivity C-reactive protein (hs-CRP) was detected by immunoturbidimetric assay (ITA). The relationship between the ratio of Treg/Th17 cells and the status of microinflammation was also analyzed. RESULTS: RORγt mRNA, IL-6 and IL-17 were significantly higher in uremia groups than those in control group (P<0.05), while mRNA expression of Foxp3 and the level of plasma IL-10 were significantly lower in uremia group than those in control group (P<0.05). The ratio of RORγt/Foxp3 mRMA was higher in uremia group than that in control group (P<0.05), and no significant difference between MHD group and CKD group was observed. The concentration of hs-CRP, which was higher than 3 mg/L, was significantly higher in uremia group than that in control group (P<0.05). The level of hs-CRP had positive correlation with RORγt, and negative correlation with Foxp3. CONCLUSION: The ratio of Th17 Treg is abnormal in uremia patients. The disequilibrium of Th17 and Treg cells has a close relationship with the status of microinflammation.     

Elevation of blood Th17 cells and CD3+CD8-IL-21+ T cells in patients with cervical cancer

AIM: To investigate the role of Th17 cells in the patients with cervical cancer.METHODS: We measured the peripheral levels of Th17 cells and CD3⁺CD8^-IL-21⁺ T cells in 37 cervical cancer (CC) patients, 25 cervical intraepithelial neoplasia (CIN) patients and 18 healthy controls by flow cytometry. The percentages of Th17 cells and CD3⁺CD8^-IL-21⁺ T cells in total CD4⁺ cells were calculated.RESULTS: Compared with controls, the patients with CC or CIN had higher proportions of Th17 cells (all P<0.01) and CD3⁺CD8^-IL-21⁺ T cells (all P<0.05). Notably, in CC patients, the increased percentages of Th17 cells and CD3⁺CD8^-IL-21⁺ T cells were independently associated with the clinical stage(all P<0.05), lymph node metastasis (P<0.01,P<0.05) and vasoinvasion (all P<0.01), while the elevated percentage of CD3⁺CD8^-IL-21⁺ T cells was also associated with the tumor size(P<0.01). Furthermore, the percentage of Th17 cells was positively correlated with that of CD3⁺CD8^-IL-21⁺ T cells in healthy controls and CC patients, but not in CIN patients.CONCLUSION: Our results indicates a possible role of Th17 cells in CC patients correlated with CD3⁺CD8^-IL-21⁺T cells, and the elevated percentage of circulating Th17 cells may be involved in the development and progression of cervical cancer.     

Role of Th17/IL-17A in chronic inflammatory airway diseases

The idea has been popular for a long time that Th1/Th2 imbalance is the major cause of many diseases. However, the Th1/Th2 paradigm has encountered increasing challenge since the discovery of a novel subset of Th cells, Th17. Th17 cells secrete a series of cytokines (IL-17A~F, IL-21 and IL-22), which is quite different from those produced by Th1 and Th2 cells. It is now generally accepted that Th17/IL-17A plays a pivotal role in autoimmune and host defense. Although first discovered in autoimmune diseases, emerging studies begin to explore the way in which Th17/IL-17A acts in chronic inflammatory airway diseases, such as asthma and chronic obstructive pulmanary disease. In this review, we will summarize the differentiation and function of Th17, and introduce the progress in the correlation between Th17/IL-17A and chronic inflammatory airway diseases. Further elucidating the mechanism of Th17/IL-17A-related pathophysiological changes will contribute to prevention and treatment of chronic inflammatory airway diseases.     

Balance of Treg/Th17 in synovium of collagen-induced arthritis rats and impact of TNF-α blockage therapy

AIM: To investigate the balance of Treg/Th17 in synovium of collagen-induced arthritis (CIA) and the impact of tumor necrosis factor α(TNF-α) blockage therapy. METHODS: Rat CIA model was established by bovine II collagen injection. The pathological score was evaluated by HE staining and toluidine blue staining. The TNF-α level in plasma was measured by ELISA. The expression of Treg/Th17 in synovium was detected by double staining immunofluorescence. RESULTS: The plasma level of TNF-α in CIA group was significantly higher than that in control group and TNFR-Fc treatment group (P<0.01), whereas no significant difference was found between TNFR-Fc treatment group and control group (P>0.05). No significant difference between CIA group and control group in the ratio of CD4⁺Foxp3⁺Treg cells/CD4⁺ cells in synovium (23.12%±4.93% vs 24.66%±5.82%, P>0.05) was observed, whereas the ratio in TNFR-Fc treatment group was significantly increased(33.07%±5.14%). The ratio of CD4⁺RORγt⁺Th17 cells/CD4⁺ cells in CIA group was significantly higher than that in control group and TNFR-Fc treatment group (9.74%±2.23% vs 1.00%±0.59%, 5.63%±1.76%, P<0.01). CONCLUSION: Differentiation disturbance of Treg/Th17 exists in the synovium of CIA rats. TNFR-Fc may restore the balance of Treg/Th17 by inhibiting Th17 cell differentiation and inducing the production or accumulation of Treg.     

Adipose-derived stem cells mediate immunosuppression of Th17 in multiple sclerosis

AIM: To investigate how human adipose-derived stem cells (hASCs) regulates the differentiation of Th17 cells in multiple sclerosis. METHODS: hASCs were isolated from the adipose tissues. Magnetic-activated cell sorting (MACS) kit was used to isolate CD4⁺ T cells from peripheral blood mononuclear cells (PBMCs) which were isolated by density gradient centrifugation. The percentage of CD4⁺ T cells was detected by flow cytometry. The activated CD4⁺ T cells were co-cultured with hASCs for about 4 d at different ratios of hASCs to CD4⁺ T cells (1:4 and 1:10) in a Th17 polarised condition. Another group adding anti-leukemia inhibitory factor (LIF) antibody was set up. Th17 cell proportion of the CD4⁺ T cells was determined by flow cytometry. The level of LIF in the supernatant of co-cultured system was measured by ELISA. The mRNA expression of retinoid-related orphan receptor γt (RORγt), interleukin-6 receptor (IL-6R), interleukin-23 receptor (IL-23R), LIF and leukemia inhibitory factor receptor (LIFR) was detected by real-time PCR. RESULTS: The result of flow cytometry suggested there were mainly hASCs, and the percentage of CD4⁺ T cells in the PBMCs were above 90% after MACS. The Th17 cell proportion decreased in 1:4 and 1:10 co-cultured groups in a dose-dependent manner. The mRNA expression of IL-6R, IL-23R and RORγt was downregulated and the expression of LIFR and LIF was up-regulated. When the anti-LIF was added into the co-cultured system, the ratio of Th17 cells increased and reached to the control level. The protein level of LIF obviously increased after co-cultured. After anti-LIF added, the mRNA expression of RORγt and IL-6R was up-regulated. CONCLUSION: hASCs inhibits the differentiation of Th17 cells from multiple sclerosis patients through the competitive inhibition of LIF/IL-6 by secreting LIF.     

Diagnostic value of Th17 cells in symptom severity and prognosis of chronic obstructive pulmonary disease

AIM: To observed the correlation between Th17 cell level and the symptom severity and prognostic factors of chronic obstructive pulmonary disease (COPD), and to explore the clinical application value of Th17 cell level in assessing the prognosis of patients with COPD. METHODS: The patients with diagnosed COPD (n=110) in our hospital during May 2013 to December 2014, and 40 healthy subjects were enrolled in the study. According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD), the COPD patients were divided into group A (low risk, less symptoms), group B (low risk, more symptoms), group C (high risk, less symptoms) and group D (high risk, more symptoms), which were given inhaled corticosteroid/long-acting β₂ agonist or corticosteroid/long-acting β₂ agonist+long-acting antimuscarinic agent treatment for 3 months. The proportion of Th17 cells, cytokines (IL-17 and IL-6), the COPD assessment test (CAT) score, age, body mass index, pulmonary function and the times of acute exacerbation of COPD in previous 1 year were observed before and after treatment. The correlation analysis between the level of Th17 cells and other clinical characteristics was performed. RESULTS: Th17 cell, IL-17 and IL-6 levels in COPD group were significantly higher than those in control group (P < 0.05). With the increase in the severity of COPD symptoms, Th17 cells, cytokines (IL-17 and IL-6) and CAT score in groups B and D were significantly higher than those in groups A and C (P < 0.05). The univariate analysis showed that the levels of Th17 cells in groups B and D before treatment were positively correlated with the CAT score (P < 0.05), which were negatively correlated with FEV₁ , FEV₁% Pred, FVC and FVC% Pred. The levels of Th17 cells were not correlated with the CAT score, FEV₁, FEV₁% Pred, FVC and FVC% Pred in groups A and C. The levels of Th17 cells after treatment were positively correlated with the CAT score, which were negatively correlated with FEV₁ , FEV₁% Pred, FVC and FVC% Pred (P < 0.05). CONCLUSION: The peripheral Th17 cell level has a good correlation with IL-17, IL-6, CAT score and pulmonary function in COPD patients, suggesting a potential value to predict the symptom severity and prognosis of COPD.     

Role of CCL17 and CCL22 expression in dendritic cells in maternal-fetal immune tolerance

AIM: To determine the expression of CCL17 and CCL22 in dendritic cells (DC) from human decidua and endometria. METHODS: The decidua were collected from normal pregnant women undergoing induced abortion and recurrent spontaneous abortion (RSA) women undergoing early abortion.The endometria were cllected from non-pregnant women undergoing abdominal hysterectomy.The mononuclear cells in the decidua and endometria were isolated. DC were induced by GM-CSF and IL-4, cultured in vitro and identified. The expression of CCL17 and CCL22 in DC at mRNA and protein levels was analyzed by real-time PCR and ELISA. RESULTS: The mRNA levels of CCL17 and CCL22 in decidual DC in normal pregnancy group were 3.04?0.40 and 1.83?0.24, respectively, significantly higher than those in endometrial DC in non-pregnancy group (0.85?0.24 and 0.31?0.08, respectively, P<0.01) and those in decidual DC in RSA group (1.65?0.14 and 0.96?0.09,respectively,P<0.01). Decidual DC continually and strongly secreted CCL17 and CCL22. The levels of CCL17 and CCL22 in normal pregnancy group were significantly higher than those in non-pregnancy group and RSA group at the same culture time point (P<0.01). CONCLUSION: The expression of CCL17 and CCL22 in decidual DC in pregnant woman increases. This may attract more CD4⁺CD25⁺ regulatory T cells to decidua and play an important role in the establishment of maternal-fetal immune tolerance.     

Effect of mesalazine on Th1, Th17 and Treg cells in mice with DSS-induced ulcerative colitis

AIM: To investigate the effect of mesalazine treatment on regulation of Th1, Th17 and Treg cells in mice with dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). METHODS: The expression of IL-17, IFN-gamma and Foxp3 in the peripheral blood mononuclear cells (PBMC) and intestinal mucosa lamina propria mononuclear cells (LPMC) of DSS-induced UC mice was detected by flow cytometry analysis. The effect of mesalazine treatment on regulaiton of Th1, Th17 and Treg cells in the mice with DSS-induced ulcerative colitis was examined.RESULTS: The expression of IL-17, IFN-γ and Foxp3 on CD4+T cells were significantly higher in the PBMC of DSS-induced mice than those in control group. CD4+ IFN-γ+T cells and CD4+ Foxp3+T cells were higher in LPMC than those in control group, except CD4+IL-17+T cells. Moreover, the Th1, Th17 and Treg cells were higher in DSS group than those in control group in LPMC. However, only Tregs was higher in PBMC. Pre-treatment with mesalazine significantly decreased the number of Th17, Th1 and Treg cells of UC model mice both in PBMC and LPMC.CONCLUSION: The Th1, Th17 and Tregs cells in DSS-induced mice were significantly higher than those in control mice, suggesting that CD4+T cell subsets play an important role in the pathogenesis of UC. Mesalazine may play a role in the treatment of UC by regulating the Th1, Th17 and Tregs cells.     

Effect of 1α, 25-dihydroxyvitamin D3 on T helper cell 17 and expression of related cytokines in penetrating keratoplasty in mice

AIM: To evaluate the effects of 1α, 25-dihydroxyvitamin D3 on T helper cell 17 (Th17 cells) and its related cytokines in a mouse model of corneal allograft transplantation. METHODS: C57BL/6 mice were transplanted with corneal grafts from BALB/c mice and treated intraperitoneally with 1.0 μg 1α, 25-dihydroxyvitamin D3 or soybean oil every other day after operation. The transparency of the corneal grafts was evaluated for potential rejection signs by slit lamp biomicroscopy and histopathology. The expression levels of IL-17, RORγt and IFN-γ in the spleen were measured by real-time PCR. Moreover, the protein expression of RORγt and IL-17 in the peripheral blood was analyzed by Western blotting. IL-17 and IFN-γ in peripheral blood were measured by flow cytometry. RESULTS: 1α, 25-dihydroxyvitamin D3 significantly inhibited the rejection of the corneal allograft and reduced the numbers of inflammatory infiltrates in the corneal graft. In the spleen, 1α, 25-dihydroxyvitamin D3 treatment reduced the expression levels of IL-17, RORγt and IFN-γ. In the peripheral blood, 1α, 25-dihydroxyvitamin D3 treatment downregulated the expression levels of RORγt, IL-17 and IFN-γ. CONCLUSION: The effects of 1α, 25-dihydroxyvitamin D3 on suppressing corneal transplantation-induced allograft rejection in mice are closely associated with its modulation on IL-17 and related cytokine RORγt.     

Change of intestinal flora and its relationship with IL-23/IL-17 axis in patients with ulcerative colitis

AIM:To investigate the change of intestinal flora distribution and its relationship with interleukin-23 (IL-23)/IL-17 axis in ulcerative colitis (UC) patients. METHODS:The fresh fecal samples from 20 patients with active UC and 20 healthy controls were collected. The distribution of the flora was analyzed by direct smear and traditional bacterial culture. The changes of bacteria were detected by real-time PCR. The hemoglobin, albumin, erythrocyte sedimentation, and C-reactive protein levels were tested routinely. Both normal and damaged mucosal tissues of UC patients were examined and obtained by colonoscopy, and further assessed by Mayo scoring, Baron grading and HE staining. The expression of IL-17 and IL-23 was observed by immunohistochemistry and Western blot. RESULTS:(1) The degree of flora imbalance in active UC patients was higher than that in the healthy controls (P<0.05). (2) The results of aerobic culture showed that the number of Escherichia coli in the UC patients was significantly lower than that in the normal controls (P<0.01), while Enterococcus was increased obviously (P<0.01). The results of anaerobic culture revealed that the numbers of Bacteroidetes, Bifidobacterium bifidum and Lactobacilli in the UC patients were significantly decreased (P<0.01). (3) Quantitative analysis of target bacteria showed that the relative quantification of Escherichia coli, Bacteroidetes, Bifidobacterium bifidum and Lactobacilli in the UC patients was significantly lower than that in the normal subjects, and the number of Enterococcus was significantly increased (P<0.01). (4) Compared with control group, no significant change of hemoglobin in the UC patients was ovserved, albumin was significantly decreased (P<0.05), but erythrocyte sedimentation and C-reactive protein levels were elevated obviously (P<0.01). (5) The Mayo score, Baron grade, and histopathological score were all increased (P<0.01). (6) High IL-17 and IL-23 expression levels were detected in the UC patients (P<0.01). (7) Correlation analysis showed that the average absorbance values of IL-17 and IL-23 expression were positively correlated with Baron grade (r=0.717, P=0.02; r=0.849, P=0.016) and pathological score (r=0.660, P=0.03; r=0.675, P=0.032). Meanwhile, the average absorbance value of IL-23 expression was negatively correlated with the number of Escherichia coli (r=-0.699, P=0.025), and positively correlated with Enterococcus (r=0.872, P=0.010). Furthermore, the average absorbance value of IL-17 expression was positively correlated with Enterococcus (r=0.764, P=0.046), and both of them were not correlated with other bacteria. CONCLUSION:Obvious flora imbalance exists in active UC patients, changed intestinal microflora is closely related with the degree of inflammation. IL-23/IL-17 axis, as a key factor in the development of UC, may be related to the changes of intestinal microflora. The interaction between intestinal microflora and IL-23/IL-17 axis plays an important role in the pathogenesis of UC.     

Effect of adoptive transfer of CD4+ T cells with miR-7 knockdown on acute liver injury in mice

AIM:To study the effect of adoptive transfer of CD4⁺ T cells with microRNA-7 (miR-7) knockdown (KD) on mouse acute liver injury model and to investigate its significance. METHODS:CD4⁺ CD62L⁺ T cells were purified from the spleen of normal wild-type (WT) mice and miR-7KD mice by magnetic bead sorting, and were stained with CFSE. These 2×10⁶ CFSE-labeling cells were injected into normal mice via tail vein, and then the mouse acute liver injury model was induced by intraperitoneal injection of 30 mg/kg concanavalin A. After 72 h, the appearance, weight and weight index of the liver were investigated. The pathological change of the liver tissues was observed by HE staining. Real-time PCR was used to examine the mRNA expression of Bax and P53. The expression levels of CD62L, interleukin-4 (IL-4) and interferon-γ (IFN-γ) in the CD4⁺ T cells were analyzed by flow cytometry. RESULTS:We found that the liver tissue became lighter, and the weight (P<0.01) and weight index (P<0.05) were changed significantly in miR-7KD mice compared with control group. Moreover, HE staining showed that the liver cell damage was increased in the liver of miR-7KD mice. Meanwhile, the expression levels of Bax and P53 were significantly increased in miR-7KD group (P<0.05). The percentage of CD62L in CD4⁺ T cells was significantly decreased (P<0.01) in miR-7KD mice, with high expression of IFN-γ (P<0.05) and low expression of IL-4 (P<0.01) in CD4⁺T cells. CONCLUSION:These findings suggest that miR-7 knockdown significantly promotes the pathology of CD4⁺ T cell-mediated acute liver injury, which provides a preliminary experimental basis for further exploration on the mechanism of acute liver injury occurrence.     

Protective effect of ischemic preconditioning on rat brain with ischemia/reperfusion injury

AIM:To study whether ischemic preconditioning(IPC) has a protective effect against ischemia/reperfusion(I/R) injury in brain, and the possible relationship between IPC and the regulating function of microcirculation.METHODS:The I/R models were established both in I/R and IPC groups of Sprague-Dawley rats. Additional procedure was performed of short term cerebral ischemic preconditioning in IPC group 24 hours before I/R. Skull windows were performed through which microcirculation features were measured before ischemia, during ischemia, and reperfusion. Finally, brains were cut into slices and stained with red tetrazoline(TTC).RESULTS:Most TTC stained brains in I/R group presented irregular palely red areas which were few in IPC group. Compared with I/R group, IPC group presented relatively increase in accumulated length of capillaries, mean cerebral microcirculatory perfusion, and microcirculatory velocity in ischemic and reperfusion phase. There was no-reflow phenomenon in I/R group in reperfusion phase, which was substituted by the course of increasing reperfusion in IPC group.CONCLUSIONS:IPC could relieve the reduction of tissue perfusion during ischemia and the no-reflow phenomenon during reperfusion by improving the regulating function of microcirculation, which relatively promote the opening of capillaries and accelerating of microvascular flow, therefore protect brain from I/R injury.     

Effect of microRNA-7 knockdown on ConA-induced acute liver injury in mice

AIM: To study the effect of microRNA-7 (miR-7) knockdown (KD) on concanavalin A (ConA)-induced acute liver injury (ALI) in mice.METHODS: Wild type (WT) mice and miR-7KD mice were received ConA (30 mg/kg) to induced acute liver injury model by intraperitoneal injection, and the morphological changes, liver weight and weight index were measured 48 h later. The pathological changes of the liver tissues were observed by HE staining. The levels of serum alanine aminotransferase (ALT), IL-4 and IFN-γ were detected by ELISA. The proportional changes of CD4⁺ T cells and the relative levels of IL-4 and IFN-γ were analyzed by flow cytometry.RESULTS: The color of the liver tissue became lighter, and the weight and weight index were changed significantly in miR-7KD mice compared with control group (P<0.05). HE staining showed that the inflammatory cell infiltration was increased in the liver of miR-7KD mice. Moreover, the level of serum ALT was significantly increased (P<0.05). The serum level of IFN-γ elevated significantly (P<0.01), while the IL-4 levels decreased significantly (P<0.01) in the serum of miR-7KD mice. Furthermore, the proportion of CD4⁺ T cells and relative IFN-γ cells increased obviously (P<0.01).CONCLUSION: miR-7 knockdown promotes the pathogenesis of the ConA-induced acute liver injury in mice.     

Effect of edaravone on expression of Aβ and AQP4 and activity of MMP2 and MMP9 in acute cerebral ischemia/reperfusion rats

AIM: To investigate the effect of edaravone on acute cerebral ischemia/reperfusion rats. METHODS: SD rats were randomly divided into sham operation group (saline), model group (modeling given saline), low dose group (edaravone at 6 mg/kg) and high dose group (edaravone at 10 mg/kg). The rat model was established by Zea Longa suture method. The nerve function scores were evaluated after operation, and the infarct volume was measured by TTC assay. The mRNA expression of aquaporin 4 (AQP4) and amyloid β-protein (Aβ) in the brain tissue was detected by RT-qPCR. The protein levels of APQ4 and Aβ were determined by Western blot. The activity of matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9(MMP9) was detected by gelatin zymography. RESULTS: Compared with model group, edaravone administration markedly alleviated neurological deficits, histological damages and brain edema. The mRNA and protein levels of AQP4 and Aβ, and the activity of MMP2 and MMP9 were downregulated (P<0.05). Furthermore, the improvements in high dose group were significantly more effective than those in low dose group. CONCLUSION: Edaravone significantly reduces neurological deficits and brain edema in the rats with acute ischemic stroke, and the mechanisms may be related to the downregulation of AQP4 and Aβ, and the activation of MMP2 and MMP9.