Development and study of experimental C57BL/6 mouse lupus nephritis model induced by pristane

AIM To establish a C57BL/6 mouse lupus nephritis model induced by pristane and to explore the pathogenic mechanism of this model. METHODS Thirty C57BL/6 mice were randomly divided into 2 groups. The mice in model group were intraperitoneally injected with 0.5 mL pristane, while the mice in control group were injected with 0.5 mL normal saline. The state of health and survival of the animals were monitored during the whole experiment. The activation of macrophages, granulocytes, dendritic cells and B cells in spleen and the markers on B cells were detected by flow cytometry on the 10th day after injection. The serum levels of antinuclear antibodies (ANA) and anti-double strand DNA antibodies (anti-dsDNA) were measured every month after injection by indirect immunofluorescence assay, and proteinuria was checked mouthy by Albustix test strips. Eight months after injection, all mice were killed, and the kidneys were slided and stained with HE or PE-labeled IgG to analyze the expression of interferon-γ (IFN-γ) and interleukin-4 (IL-4). The evidence of glomerulonephritis was histopathologically observed, and the ultrastructural changes of the glomerulus were determined by transmission electron microscopy. RESULTS Ten days after the pristane injection, the populations of macrophages, granulocytes, dendritic cells and B cells were increased significantly compared with control mice (P<0.05). The expression of B7-1, B7-2 and MHC-II on the B cells was also increased (P<0.05). The serum levels of ANA and anti-dsDNA were increased from 3 to 8 months (P<0.05). Meanwhile, part of the mice showed different degrees of ascites, emaciation or even death, part of the mice had proteinuria 4 months later, and 8 months later, all of the model mice had proteinuria, with 1~20 g/L of urine protein. At the 8th month, a large number of heterotopic lymphoid tissues appeared in the abdominal cavity. The deposition of immune complexes in glomeruli and mesangial areas was serious. The expression of IFN-γ in the renal tissues was increased. Pathological damages such as lymphocyte infiltration, tissue necrosis and deposition of electron dense substances were obvious in the model mice. In control group, autoantibodies and proteinuria was not detected under the same experimental condition. Meanwhile, no evidence of glomerulonephritis in the control mice was observed. CONCLUSION The C57BL/6 mouse model of lupus nephritis induced by pristane is established successfully.     

Protective effect of curcumin on MRL/lpr mice with lupus nephritis and its mechanism

AIM To observe the effect of curcumin （Cur） on lupus nephritis （LN） and its possible mechanism. METHODS Thirty 10-week-old MRL/lpr lupus mice were randomly divided into MRL/lpr group， Cur-L and Cur-H group with 10 mice in each group， and C57BL/6 mice （n=10） served as normal control （NC） group. The mice in Cur-L group and Cur-H group were given intragastric administration of Cur at 100 and 200 mg·kg^-1·d^-1 for 12 weeks， respectively， and the same volume of normal saline was given to the mice in NC group and MRL/lpr group. The urine protein was detected， and the morphological changes of the renal tissue were observed by HE staining after treatment. The levels of serum creatinine （SCr）， blood urea nitrogen （BUN） and serum anti-double-stranded DNA （dsDNA）， and interleukin-1β （IL-1β）， IL-6 and tumor necrosis factor-α （TNF-α） levels in serum and renal tissues were detected. The protein levels of p-IκB， NF-κB， NLRP3 and caspase-1 in the renal tissues were determined by Western blot. RESULTS Compared with MRL/lpr group， the content of urine protein in Cur groups was significantly reduced， and the renal injury was relieved. The SCr， BUN， serum anti-dsDNA， and the serum and renal levels of IL-1， IL-6 and TNF-α were all significantly reduced， and the protein levels of p-IκB， NF-κB， NLRP and caspase-1 in the renal tissue were significantly decreased （P<0.05）. CONCLUSION Cur has a certain protective effect on the kidney of MRL/lpr mice， and its mechanism may be related to the inhibition of NF-κB and NLRP3 signaling pathways.     

Up-regulation of CD36 induced by casein-induced inflammation promotes renal injury in mice

AIM: To investigate the role of CD36 in casein-induced mouse renal injury.METHODS: Eight-week-old male C57BL/6J mice and CD36 knockout (CD36KO) mice were randomly divided into C57BL/6J saline injection group, C57BL/6J casein injection group and CD36KO casein injection group (n=8 in each group). After 14 weeks of treatment with high-fat diet, the mouse serum, 24 h urine and kidney tissue samples were collected for analysis. The serum content of tumor necrosis factor-α (TNF-α) was measured by ELISA. The renal function markers in the serum and urine were determined by an automatic biochemical analyzer. The pathological changes of the kidney were observed by HE staining and Masson staining. The expression of CD36 and cytokines/chemokines (TNF-α, IL-6 and MCP-1) at mRNA and protein levels in the renal tissues were determined by real-time PCR and Western blot. The content of tissue hydrogen peroxide (H₂O₂) was measured by a commercial kit. The protein levels of Nrf2 and TGF-β1 in the renal tissues were measured by immunohistochemical staining.RESULTS: Compared with saline injection group, casein injection increased the level of TNF-α in the serum and in the kidney tissues of C57BL/6J mice (P<0.05), suggesting that casein injection successfully induced chronic inflammation in C57BL/6J mice. Casein injection also promoted the protein expression of CD36 and TGF-β1 in the renal tissues of the C57BL/6J mice, accompanied with glomerular sclerosis, proteinuria, increased serum creatinine content, increased H₂O₂ content, and decreased Nrf2 protein level and the ability of antioxidant in the kidneys (P<0.05). Furthermore, CD36 deficiency protected the mice from casein-induced renal injury, as evidenced by improved kidney pathological changes and decreased proteinuria. The content of H₂O₂ in the kidneys of casein-treated CD36 knockout mice was also lower than that in casein-treated C57BL/6J mice.CONCLUSION: Inflammatory responses promote the oxidative stress and renal injury in a CD36-dependent manner.     

Effects of arsenic trioxide on T-bet/GATA3 signal pathway in MRL/lpr mice

AIM: To investigate the effect of arsenic trioxide (ATO) on T-bet/GATA3 signal pathway in MRL/lpr mice.METHODS: MRL/lpr mice and C57BL/6J mice at the age of 20 weeks were chosen and then divided in 2 different sub-groups, respectively. The mice in 2 sub-groups received ATO (0.4 mg·kg^-1·d^-1) and sodium chloride (NS, volume weight-determined) by intraperitoneal injection respectively for 2 months. Afterward, the spleens were isolated from the MRL/lpr and C57BL/6J mice under pathogen-free condition and the suspensions were prepared. The mRNA level of T-bet, GATA3, IFN-γ,IL-4 and the mRNA ratio of T-bet/GATA3 were detected by RT-qPCR. The protein expression of T-bet and GATA3 was determined by Western blot. The serum levels of IFN-γ and IL-4 were measured by ELISA.RESULTS: The mRNA and protein levels of T-bet, IFN-γ and the mRNA ratio of T-bet/GATA3 in NS group of MRL/lpr mice were higher than those in NS group of C57BL/6J mice (P<0.05). However, the GATA3 and IL-4 were lower in NS group of MRL/lpr mice in both mRNA and protein level (P<0.05). In MRL/lpr mice, the mRNA and protein levels of T-bet, IFN-γ and the mRNA ratio of T-bet/GATA3 were lower in ATO group compared with NS group (P<0.05), no difference was found in GATA3 and IL-4. No difference of the indexes mentioned above between ATO group and NS group in C57BL/6J mice was observed.CONCLUSION: ATO may affect the signaling pathway of T-bet/GATA3 to down-regulate the mRNA expression and the protein secretion of IFN-γ by decreasing the expression of T-bet in MRL/lpr mice.     

Effects of amifostine on formation of abdominal aortic aneurysm in mice induced by benzo[a] pyrene

AIM: To study the role of amifostine on the formation of benzo[a]pyrene (BaP)-induced abdominal aortic aneurysm (AAA) in C57BL/6J mice and the underlying mechanism. METHODS: RAW246.7 mononuclear macrophage in vitro were divided into control group, DMSO group, BaP group, low dose (1 μmol/L) amfostine treated group, middle dose (5 μmol/L) amfostine treated group and high dose (25μmol/L) amfostine treated group. The influence of BaP on the expression of matrix metalloproteinase (MMP)-9, MMP-12, TNF-α, NF-κB in the RAW246.7 mononuclear macrophages in vitro was determined by Western blot. Male C57BL/6J mice (8 months old) were divided into control group, model group (AngII+BaP group), low dose (50 mg/kg) amfostine treated group and high dose (100 mg/kg) amfostine treated group. After 6 weeks, the abdominal aorta were isolated. The aortic tissues were subjected to HE and Masson staining. The vascular wall structure, infiltration of macrophage, the expression of MMP-9, MMP-12, TNF-α, NF-κB were evaluated by Western blot and immunochemistry staining. RESULTS: Amifostine attenuated BaP-induced expression of TNF-α, MMP-9, MMP-12, NF-κB in the RAW246.7 mononuclear macrophages (P<0.05). The results of animal experiments showed that the incidence of AAA in high dose amifostine treated group were significantly lower than that in low dose amifostine treated group and model group (P<0.05). Immunohistochemistry staining observation showed that amifostine inhibited the aortic macrophage infiltration more obviously in high amifostine treated group compared with model group and low dose amifostine treated group (P<0.05). Compared with model group and low dose amifostine treated group, the MMP-9, MMP-12, TNF-α and NF-κB expression of abdominal aorta in high amifostine treated group was reduced significantly (P<0.05). CONCLUSION: Amifostine inhibits BaP-induced activation of macrophages, and also prevents the formation of abdominal aortic aneurysm in C57BL/6J mice induced by BaP by inhibition of the NF-κB pathway, macrophage infiltration and the expression of TNF-α and MMPs.     

Expression of scavenger receptor B1 (SR-B1) in the liver of high fat and sugar diet-induced diabetic mice

AIM: To investigate serum lipid and the expression of SR-B1 in the livers of diabetic mice. METHODS: Ten normal diet, female C57BL/6J mice, fifteen high fat and sugar diet female C57BL/6J mice, five fed 8 weeks and ten fed 16 weeks were used in the experiment. Serum total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), insulin (INS) and the expression of SR-B1 in the livers were measured. RESULTS: 1. In the high fat and sugar diet mice, serum TC and FBG at 16 weeks were significantly higher than that in normal diet mice (P<0.05). 2. The expression of SR-B1 protein in the liver of high fat and sugar diet mice was the higher than that in normal mice, and the SR-B1 expression in the liver of the mouse fed 16 weeks was also higher than that fed 8 weeks. CONCLUSION: The expression of SR-B1 protein in the liver of type 2 diabetes mice is higher than that in normal mice, perhaps it is related to the decrease in serum HDL-C.     

Effect of lupus recipe on immune system and lymphocyte subsets proliferation in splenic cells of lupus-prone BXSB mice

AIM: To investigate the effects of lupus recipe on immune system and lymphocyte subsets proliferation in splenic cells in BXSB mice. METHODS: Eighteen male BXSB mice model was used in the experiment. The model mice were divided into three groups: un-treated model group, lupus recipe (LR) treated group, and prednisone treated group. All model mice were killed in 10 weeks. The control group consisted of 6 syngeneic normal C57BL/6 male mice. The levels of total IgG and anti-dsDNA antibody in serum were detected by ELISA. The percentages of lymphocyte subsets (CD3+, CD4+, CD8+ T lymphocytes and CD19+, CD23+ B lymphocytes) were detected by using flow cytometry analysis. RESULTS: (1) The serum levels of total IgG and anti-dsDNA antibody in un-treated model group were higher than that in other groups. There was no differences among LR treated group, prednisone treated group and control group. (2) The percentages of CD3+, CD4+, CD8+ T lymphocytes and CD19+, CD23+ B lymphocytes in model group were obviously higher than that in normal control. (3) Compared to un-treated model group, the percentages of CD4+, CD8+ T lymphocytes and CD19+, CD23+ B lymphocytes in LR or prednisone treated group were significantly reduced, which closely reached the levels in normal group. CONCLUSIONS: The immune functions of T and B lymphocytes in BXSB mice are up-regulated. LR inhibits the activation of T and B lymphocytes, reduces the serum levels of IgG and auto-antibody production.     

“2012年园艺植物染色体倍性操作与遗传改良学术研讨会”预备通知

自2008年11月在中国农业科学院郑州果树研究所成功召开园艺植物染色体倍性操作与遗传改良研讨会以来,我国科研人员在该领域的研究取得了可喜的成绩。为进一步总结近几年来在该领域的研究进展,促进园艺植物倍性育种研究,同时为该领域的专家、学者和同仁们提供良好的交流平台。中国园艺学会定于2012年4月中旬在重庆召开园艺植物染色体倍性操作与遗传改良学术研讨会。欢迎从事该研究领域及相关研究工作的人员参加。     

Increase in proliferation of adventitial fibroblasts at early stage of atherosclerosis in apoE(-/-) mice

AIM: To study the relationship between the proliferation of adventitial fibroblasts and the early formation of atherosclerotic lesion. METHODS: ApoE(-/-) mice and wild-type C57BL/6 black mice (6-week old) were used in this experiment. 5-Bromo-2-deoxyuridine (BrdU) was administered 24 h before the animals were sacrificed at time points of 0, 2, 4 or 10 weeks after hyperlipidic diet, respectively. The ascending aorta was removed for serial sectioning. The morphological changes of the aortic tissues were observed under microscope with HE staining. Some sections of the aorta were used to observe the BrdU labeling in the adventitia and intima at different time points by the method of immunohistochemistry. In addition the arterial adventitial fibroblasts derived from apoE(-/-) mice and C57BL/6 mice after hyperlipidic diet for 2 weeks were cultured. The proliferation of the cells was examined by BrdU incorporation. The cell cycle was examined by flow cytometry. RESULTS: In vivo the BrdU-labeled cells were first found in the adventitia of apoE(-/-) mice after feeding with hyperlipidic diet for 2 weeks, the time point that no visible intimal lesion formation was found, and then subsequently emerged in the intimal lesion. No BrdU labeling was observed in C57BL/6 mice at any time point. The number of BrdU labeled cells in the adventitial fibroblasts of apoE(-/-) mice was significantly higher than that in C57BL/6 mice in vitro (P<0.01). The adventitial fibroblasts of apoE(-/-) mice exhibited higher percentages of S and G₂/M phases than those in C57BL/6 mice (P<0.05). CONCLUSION: The proliferation of arterial adventitial fibroblasts might participate in the early formation of atherosclerotic lesions.     

Effect of GLP-1 receptor agonist on lipolysis in adipose tissue of obese mice and its underlying mechanism

AIM: To investigate the effects of glucagon-like peptide-1(GLP-1) receptor agonist exendin-4 on white adipose tissue (WAT) and the underlying mechanisms. METHODS: Male C57BL/6J mice (8 weeks) were challenged by high-fat diet for 12 weeks, and were randomly divided into saline group and exendin-4 group. The mRNA expression of sirtuin 1(SIRT1), adipose triglyceride lipase (ATGL), TNF-α and adiponectin of WAT was detected by real-time PCR. 3T3-L1 adipocytes or mouse embryonic fibroblasts cells were treated with exendin-4 for 24 h. The protein levels of SIRT1, ATGL and hormone-sensitive lipase (HSL) were determined by Western blot.RESULTS: Exendin-4 significantly decreased epididymal fat weight, fasting blood glucose and serum triglyceride levels (P<0.05), and reduced body weight and serum TNF-α level. The mRNA expression of SIRT1, ATGL and adiponectin in WAT was all significantly up-regulated by exendin-4, which were contrary to the down-regulation of TNF-α mRNA expression (P<0.05). Exendin-4 promoted the protein expression of SIRT1, ATGL, and HSL in 3T3-L1 adipocytes in a dose-dependent manner. Less lipid droplets with up-regulation of lipolytic protein expression were observed when combined with SIRT1 agonist treatment, which were suppressed by SIRT1 inhibitor. Deletion of SIRT1 led to larger adipocytes with more lipid droplets, and the effect of exendin-4 on the lipolysis disappeared when SIRT1 was deficient.CONCLUSION: Exendin-4 promotes lipolysis in WAT of obese mice via activation of SIRT1.     

Role of Api6 in lung inflammation induced by high fat/cholesterol food in C57BL/6J mice

AIM：To investigate the function of apoptosis inhibitor 6 (Api6) in lung inflammation induced by high-fat high-cholesterol diet (HFD/HCD) in male C57BL/6J mice. METHODS：Male C57BL/6J mice (6~8 weeks old) were randomly divided into 2 groups and treated with regular diet and HFD/HCD, respectively. After 16 weeks of feeding, the lung tissues were collected and the pulmonary inflammatory status was determined by immunohistochemistry and ELISA. The mRNA and protein expression levels of Api6 were determined by real-time PCR and Western blotting. The apoptotic rate of bronchioalveolar lavage cells was examined by flow cytometry. RAW264.7 cells were cultured in vitro and the apoptosis induced by oxidized low-density lipoprotein (oxLDL) was detected by flow cytometry. RESULTS：Accumulation of macrophages and increases in both tumor necrosis factor α and monocyte chemoattractant protein 1 were observed in the lung tissues of 16-week HFD/HCD-fed C57BL/6J mice. Compared with the regular diet-fed mice, the expression of Api6 at mRNA and protein levels in the lung tissues was highly increased in the HFD/HCD-fed mice (P<0.01). Meanwhile, the apoptotic rate of bronchioalveolar lavage macrophages from the HFD/HCD-fed mice was highly inhibited (P<0.01). In vitro, 500 μg/L recombinant Api6 significantly inhibited the apoptosis of RAW264.7 cells induced by oxLDL (P<0.05). CONCLUSION：HFD/HCD feeding results in the accumulation of macrophages in the lung of C57BL/6J mice, which may partly due to the increased expression of Api6 and its anti-apoptotic role in macrophages.     

PPARγ gene and protein expression in aortic plaque of different week-old apoE-knock out mice and the relationship with the composition of aortic plaque

AIM: To investigate the relationship of PPARγ gene expression with the composition of aortic plaque in apoE-knock out mice. METHODS: PPARγ gene and protein in aortic area of 20-week-old and 40-week-old apoE-knock out mice were investigated using RT-PCR and immunoblotting. The same aged wild type mice (C57BL/6J) were served as control (n=10). The composition of aortic plaques was analyzed by Movat method and oil red O staining. The expression of antigens such as PPARγ, SM-actin and MOMA-2 in aortic plaque were compared using immunohistochemistry. The relationship of PPARγ with macrophage, smooth muscle cells (SMC), lipid, elastic fiber, collagen and proteoglycan in aortic plaque were analyzed using immunofluorescence. RESULTS: PPARγ gene and protein in aortic wall and plaque of apoE-knock out mice were more significant than that in the same aged C57BL/6J mice (P<0.05). PPARγ expression at 40-week-old apoE-knock out mice was most significant and very low in C57BL/6J mice. More PPARγ expression of gene and protein at 20-week-old C57BL/6J mice than 40-week-old C57BL/6J mice were observed. Compared with 20-week-old apoE^-/- mice, the lipid pool in aortic plaque at 40-week-old apoE^-/- mice were increased remarkably, while elastic fiber, collagen and proteoglycan in plaque were decreased and aortic remodeling was very significant. Even, upregulation of MOMA-2 and downregulation of SM-actin were also detected in latter (P<0.05). In addition to SMC of aortic tunica media, PPARγ also expressed in SMC and macrophages in the aortic plaque of apoE^-/- mice. PPARγ was very enriched in lipid pool of the plaque. CONCLUSION: PPARγ expression level decreases with aging in C57BL/6J mice, while increases with plaque progression in apoE-knock out mice. There is positive correlation between PPARγ expression and lipid composition in plaque. The observed upregulation of PPARγ gene expression in aortic plaque may be a compensatory behavior and protective mechanism in apoE-knock out mice.     

Resveratrol regulates iNOS to inhibit atherosclerosis in C57BL/6J mice

AIM: To investigate the effect of resveratrol on the lipids(CHOL, TG, LDL-C and HDL-C), nitric oxide(NO), peroxynitrite anion(ONOO^-) and the expression of inducible nitric oxide synthase(iNOS) in the artery of the mice with ovariotomy(OVX).METHODS: The lipid levels and NO level in the serum were measured. The changes of atherosclerosis were evaluated with Oil Red O staining. The expression of iNOS was measured by DAB staining and Western blot. The ONOO^- production was measured by DAB staining.RESULTS: Compared with sham group, the levels of the lipids and NO production in OVX+ high fat(HF) group were increased(P<0.05). Compared with OVX+HF group, the levels of the lipids and NO production in resveratrol group were decreased(P<0.05). Fourteen weeks later, the atherosclerosis model was successfully established. Compared with OVX+HF group, the iNOS expression and the ONOO^- production in resveratrol group were decreased(P<0.05), while those in sham group were increased(P<0.05).CONCLUSION: Resveratrol prevents and treats atherosclerosis by inhibiting the iNOS expression in C57BL/6J mice.     

Clinical significance of elevated serum interleukin 15 in patients with active lupus nephritis

AIM: To detect interleukin 15 (IL-15) levels in peripheral blood from patients with active lupus nephritis and investigate its clinical significance. METHODS: IL-15 level was determined by enzyme linked immunosorbent assay (ELISA). The peripheral blood mononuclear cells (PBMCs) were isolated with grads density abaxiality. The inhibitory effects of dexamethasone on production of IL-15, IgG and anti-dsDNA antibody in cultured PBMCs from LN patients were also investigated. RESULTS: (1) Serum IL-15 level in LN patients was significantly higher than that in normal controls (P<0.01). Serum IL-15 level in active LN patients was significantly higher than that in remised patients (P<0.05). (2) Serum IL-15 level was positively correlated with SLEDAI, anti-dsDNA antibody and 24 h urine protein excretion in active LN patients. (3) Serum IL-15 level was significantly reduced in LN patients treated with combination of cyclophosphamide (CTX) and steroid for 12 weeks. (4) Secretion of IL-15, IgG and dsDNA antibody in cultured PBMCs from active LN patients was significantly higher than that in normal control group, and IL-15 level in supernatant of cultured PBMCs from active LN patients was positively correlated with IgG and dsDNA antibody. Dexamethasone inhibited the secretion of IL-15, IgG and dsDNA antibody in cultured PBMCs from LN patients. CONCLUSION: Serum IL-15 level in patients with active lupus nephritis is significantly elevated, suggesting that IL-15 may be involved in the pathophysiological process of LN. IL-15 may be used as an index to assess the activity of LN.     

Effect of L-glutamine on obesity and insulin resistance in high-fat diet-induced C57BL/6J mice

AIM:To explore the effect of L-glutamine (Gln) on obesity and insulin resistance in high-fat diet(HFD)-induced C57BL/6J mice. METHODS:Male C57BL/6J mice (n=60) were randomly divided into normal control (NC) group, HFD group, HFD+L-alanine (Ala) group and HFD+Gln group. Each group had 15 mice. The body weight of the mice was recorded weekly. Fasting blood glucose (FBG) of the mice was tested after 12-h fasting only with water-drinking at the end of the 16th week. The mice were sacrificed and epididymal fat pad was measured. The levels of insulin (INS), leptin (LEP), adiponectin (APN) and glucagon-like peptide-1 (GLP-1) were measured by ELISA. The insulin resistance index (IRI) and insulin sensitivity index (ISI) were calculated. RESULTS:Compared with NC group, the body weight, epididymal fat pad weight, and the levels of FBG, INS, IRI and LEP increased significantly in HFD group (P<0.05), while the levels of ISI and APN decreased significantly (P<0.05). Compared with HFD group, the body weight, and the levels of FBG, IRI and LEP decreased significantly in HFD+Gln group (P<0.05), while the levels of ISI and APN increased significantly (P<0.05). No significant difference of serum GLP-1 levels the four groups was observed. CONCLUSION:L-glutamine reduces the body weight and attenuates the insulin resistance of HFD-induced mice.     

Influence of chronic corticosterone injection on depression-like behavior and brain glycogen levels in mice

AIM: To study the effect of chronic corticosterone (CORT) injection on the depression-like behaviors and the brain glycogen level in mice. METHODS: Male C57BL/6N mice (n=40) were randomly divided into normal control group and model group. The mice in model group were subcutaneously consecutively injected with CORT for 4 weeks. The mouse model of chronic stress depression was constructed. The forced swim test and open field experiment were conducted to prove chronic stress model. The serum level of CORT in the mice was measured by radioimmunoassay. The protein levels of hippocampal synaptophysin (SYP) and brain-derived neurotrophic factor (BDNF) were detected by Western blot. Hippocampus glycogen, glycogen synthase and glycogen phosphorylase were determined by indirect fluorescence measurement. RESULTS: Compared with normal control group, the immobility time of the forced swim test in model group was significantly lengthened (P<0.01), and the ability of spontaneous activity was reduced (P<0.01), indicating that chronic CORT injection induced depression-like behaviors in mice. The CORT level increased significantly (P<0.01) in model group. CORT injection decreased the protein expression of hippocampal SYP and BDNF (P<0.01), reduced hippocampal glycogen level (P<0.05) and glycogen synthase activity (P<0.05), and increased glycogen phosphorylase activity (P<0.05). CONCLUSION: Chronic CORT injection causes hippocampal neuron damage and induces the depression-like behaviors of mice, which may be associated with decreasing hippocampal glycogen level by CORT.     

The Effect and mechanism of gestational estrogen and progesterone level on H-Y mismatched skin graft survival in murine model

AIM: To investigate the effect of estrogen(E₂) and progesterone(P₄) alone or applied together to H-Y skin graft and the potential mechanism.METHODS: The female C57BL/6 mice were ovariectomized and divided into four groups(n=12 in each). The mice were treated consecutively for 14 d with subcutaneous injection of saline, E₂ and P₄ alone or in combination, respectively. Before and after H-Y skin grafting, half mice of each group were sacrificed, and the CD4⁺CD25⁺Foxp3⁺ regulatory T cells of peripheral blood and the serum cytokines were detected by flow cytometry and ELISA, respectively. The skin graft survivals of the other half were observed.RESULTS: E₂ alone could significantly augment the proportion of regulatory T cells. In the presence of H-Y antigen, this effect was further enhanced(P<0.05). By contrast, P₄ had no effect on the expression of Foxp3, regardless of the presence of H-Y antigen or not(P>0.05). The effect of E₂ in combination with P₄ was similar to that of E₂ alone(P>0.05). The administration of sex hormone regardless of E₂ and P₄ alone or in combination, significantly decreased production of pro-inflammatory cytokines, but increased production of anti-inflammatory cytokines(P<0.05). The skin graft survivals were significantly prolonged in the different experimental groups compared to vehicle control group. E₂ and P₄ had a synergistic effect to prolong the skin graft survivals(P<0.05). CONCLUSION: E₂ and P₄ suppress the inflammatory response and enhance the regulatory response to exogenous antigen, through influencing the levels of cytokines and/or the proportion of regulatory T cells, which may contribute to induce the transplant tolerance.     

The therapeutic effect of embryonic stem cells on acute lung injury induced by bleomycin in mice

AIM: The aim of this study was to observe and compare the therapy effect of different kinds of embryonic stem cells (ESCs) on pulmonary injury of mice exposed to bleomycin. These embryonic stem cells were C57BL/6J-ESC,S8-ESC and human-ESC.METHODS: (1) Fifty C57BL/6J female mice were divided randomly into five groups, which were blank control group, bleomycin model group, bleomycin model injected with C57BL/6J-ESC group, bleomycin model with S8-ESC group and bleomycin model with human ESC group. Every group has ten mice. (2) The mice of control group were administrated 0.9% sodium chloride solution and the mice in other four groups were administrated bleomycin intratracheally. Three different kinds of ESCs were administrated to the mice in three different ESCs-treated groups respectively one hour after bleomycin exposure. The life-span and hydrocyproline concentration were examined. The pathologic changes of the lung and the engraftment of the ESCs in the injured lung were observed. RESULTS: (1) The death rate in three different ESCs-treated groups declined much more obviously than that in the control group on 8 days after bleomycin exposure (bleomycin model group 50%, C57BL/6J-ESC group 37.5%, S8-ESC group 20%, human-ESC group 20%). (2) The extent of pathologic changes of the lung in S8-ESC group was lighter significantly than that in the bleomycin model group, but in C57BL/6J-ESC group and human-ESC group, their pathologic changes were similar to that in bleomycin model group. (3) The hydrocyproline concentration in S8-ESC group was lower distinctly than that in bleomycin model group (P<0.01); the hydrocyproline concentration in human-ESC group was also lower than that in bleomycin model group (P<0.05); there was no significant difference between C57BL/6J-ESC group and bleomycin model group (P>0.05). (4) The positive signals of three kinds of ESCs could be found in the lung at 1, 3, 12 and 24 hours after the stem cells were administrated, but signals were the strongest 3 hours after stem cells were given. All of the signals disappeared three days later. CONCLUSION: S8-ESCs transplantation can improve the tolerence of mice to bleomycin and ameliorate acute lung injury.