Objective To investigate the possible mechanism of aggregation and activation of neu-trophils(polymorphonuclear neutrophils,PMN)in mice with chlamydial pneumonitis. Methods C57BL/ 6 mice were inoculated intranasally with 3×103 inclusion-forming units(IFU)of Chlamydia muridarum(Cm) to induce the murine model of chlamydial pneumonitis. Samples of lung tissues collected at different time points after infection were stained by hematoxylin and eosin for histopathological assessment of inflammation. The levels of myelo-peroxidase(MPO)were detected for the evaluation of PMN aggregation. The mononu-clear cells were isolated from lung tissues. The inflammatory cells were counted with Giemsaˊs staining. CD11b+Gr1+ cell population and CD11b expression in lung mononuclear cells were analyzed by flow cytome-try. The expression of chemokines(MIP-2,LIX,KC and MCP-1)in lung tissues at mRNA level was meas-ured by RT-PCR. Results Chlamydial pneumonitis was induced in mice by intranasal inoculation of 3×103 IFU of Cm. Compared with the mice from control group,large amounts of inflammatory cells including PMN, monocytes and lymphocytes were induced in lung tissues of mice with Cm infection. PMN responded earlier than monocytes to the infection. The levels of MPO were significantly increased in mice with Cm infection and reached the highest level on the 7th day after infection. A decline in MPO levels was observed on the 14th day but the levels were still higher than those on day 0. The percentages and total numbers of CD11b+Gr1+ cells were significantly increased after Cm infection. Moreover,an increased expression of PMN CD11b was also detected by flow cytometry. The expression of chemokines(MIP-2,LIX,KC and MCP-1)was in-creased in lung tissues of mice after Cm infection. The results of the study indicated that Cm infection in-duced the expression of PMN chemoattractants,resulting in the recruitment of PMN. Conclusion The infil-tration and activation of PMN in lung tissues of mice were induced by Cm infection through increasing the ex-pression of chemokines. PMN played an important role in immune responses against Cm infection.

Objective:To investigate the effect of IL-17A on the differentiation and maturation of murine bone marrow-derived dendritic cells( BMDCs ) . Methods: Murine bone marrow cells were isolated and cultured in RPMI1640 complete medium in the presence of GM-CSF(20 ng/ml) for 8 days to induce differentiation of murine bone marrow cells to DC progenitors. Then these cells were treated with LPS(1 μg/ml) for 36 h which polarized immature DCs into mature DCs. Different concentrations of rmIL-17A(10 or 100 ng/ml) was added to the culture medium at different stages of BMDC differentiation and maturation. Co-stimulatory molecules expression on BMDC were analyzed by flow cytometry,and the culture supernatants were analyzed for IL-12p40 and IL-10 level by ELISA. Results:rmIL-17 could promote co-stimulatory molecules( CD40,CD80,CD86 and MHCⅡ) expression on BMDCs in a does-dependent manner,especially,the expression of CD40 and MHCⅡhad a significant increase in high concentration of rmIL-17A group;rmIL-17A was added while LPS induced maturation of BMDCs. CD40,CD80,CD86 and MHCⅡexpression on BMDC increased sharply in LPS plus rmIL-17A stimulation group,besides,CD86,MHCⅡ showed a higher level expression on BMDC with the increase of con-centration of rmIL-17A. Furthermore,secretion of IL-12p40 and IL-10 increased significantly in the group of DCs treated with LPS plus low concentration of rmIL-17 compared with the group without rmIL-17(P<0. 001). However,high concentration of rmIL-17A group showed significantly higher levels of IL-12p40(P<0. 001),but there was no difference in IL-10. Conclusion:IL-17A promotes the phe-notypic development of BMDC progenitors propagated in GM-CSF and cooperate with LPS to induce BMDC differentiation and matura-tion.

Objective:To investigate whether interleukin(IL)-1β is involved in pyroptosis which leads to mouse islet β cell line βTC-6 cell damage, and to explore the role of JNK inhibitor SP600125 in inhibiting IL-1β induced βTC-6 cell pyroptosis.Methods:βTC-6 cell line and mouse islets were incubated with IL-1β for 48 h or intervened with both JNK inhibitor SP600125 and IL-1R antagonist IL-1Ra, then GSDMD expression and β cell pyroptosis morphology were detected by immunofluorescence staining of GSDMD and DAPI. The expression levels of Gsdmd, IL-1β and IL-18 mRNAs were detected by real time fluorescence PCR, and apoptosis was examined by Annexin-V/7-AAD staining combined with flow cytometry.Results:βTC-6 cell pyroptotic body was significantly increased in the IL-1β treated group compared with the control group, and the expressions of pyroptosis related genes Gsdmd, IL-1β, and IL-18 mRNA were significantly higher( P<0.05), and apoptosis was increased, suggesting that IL-1β effectively induced the βTC-6 cell pyroptosis, IL-1Ra prevented IL-1β induced βTC-6 cell pyroptosis. In the presence of JNK inhibitor SP600125, IL-1β treatment failed to induce the expressions of Gsdmd and IL-18 mRNA, markers of pyroptosis, and reduced the rate of apoptosis, indicating that SP600125 suppressed IL-1β induced βTC-6 cell pyroptosis. Conclusion:Pyroptosis is one of the mechanisms of βTC-6 cell impairment caused by IL-1β, and SP600125, a JNK inhibitor, can block the IL-1β induced pyroptosis pathway and has a potential role in inhibiting βTC-6 cell pyroptosis.

Objective:To investigate the correlations of β cell dedifferentiation in non-diabetic subjects with risk factors for type 2 diabetes mellitus(T2DM).Methods:Immunofluorescence staining with insulin and β cell dedifferentiated marker ALDH1A3 was used to evaluate the β cell dedifferentiation levels in 38 non-diabetic and 23 T2DM. Correlation analyses were performed between β cell dedifferentiation levels and available clinical parameters including age, body mass index, HbA 1C level, triglycerides, and cholesterol levels in non-diabetic subjects. Results:β cell dedifferentiation level defined by the positive expression of ALDH1A3 in β cells(ALDH1A3 + INS + cell proportion) was significantly elevated in T2DM subjects( P<0.001). In PreD subjects, ALDH1A3 + INS + cells proportion were decreased( P=0.050) and negatively correlated with HbA 1C( r=-0.44, P=0.006), but not with age and body mass index. The analysis of correlation with lipidemic parameters showed that ALDH1A3 + INS + cells proportion was positively correlated with plasma total cholesterol level( r=0.39, P=0.045), but not plasma total triglyceride. Conclusion:ALDH1A3 + INS + cells were found to be decreased in prediabetes, suggesting that there may be enhanced β-cell identity in prediabetes to compensate for insulin secretion requirements; ALDH1A3 + INS + cells were elevated in people with high plasma total cholesterol levels, suggesting that total cholesterol may be one of the factors that induce β-cell dedifferentiation.

Background and Objectives: Adipose tissue-derived mesenchymal stem cells (ASCs) are recognized as an advantaged source for the prevention and treatment of diverse diseases including type 2 diabetes mellitus (T2DM). However, alterations in characteristics of ASCs from the aforementioned T2DM patients are still obscure, which also hinder the rigorous and systematic illumination of progression and pathogenesis. Methods: and Results: In this study, we originally isolated peripancreatic adipose tissue-derived mesenchymal stem cells from both human type 2 diabetic and non-diabetic donors (T2DM-ASCs, ND-ASCs) with the parental consent, respectively. We noticed that T2DM-ASCs exhibited indistinguishable immunophenotype, cell vitality, chondrogenic differentiation and stemness as ND-ASCs. Simultaneously, there’s merely alterations in migration and immunoregulatory capacities in T2DM-ASCs. However, differing from ND-ASCs, T2DM-ASCs exhibited deficiency in adipogenic and osteogenic differentiation, and in particular, the delayed cell cycle and different cytokine expression spectrum. Conclusions The conservative alterations of T2DM-ASCs in multifaceted characteristics indicated the possibility of autologous application of ASCs for cell-based T2DM treatment in the future.

Objective To retrospectively compare the efficacy of Serva NB1 collagenase with Vitacyte GOLD collagenase on islet isolation of pancreas.Methods All the human pancreata were obtained from Chinese organ donors.In GMP laboratory,the pancreata were trimmed and distended with Serva NB1 collagenase (Serva NB1,n =12) or Vitacyte GOLD collagenase (Vitacyte GOLD,n =5) and digested according to a modified Ricordi semi-automatic protocol,and the digestion duration was recorded.The digested islets were then collected and washed,followed by the continuous density purification in a Cobe 2991 cell separator.The islet yield,purity,viability and glucose-stimulated insulin release (GSI) were determined each time after purification.Quantity and quality of isolated islets were determined by digestion efficacy.Results The digestion duration in Vitacyte GOLD collagenase group was significantly shorter than in Serva NB1 collagenase group to achieve the same digestion endpoint (P＜ 0.05).The islets yields of different sizes were variable between the two groups.The Vitacyte GOLD collagenase digestion produced more islets with a diameter range of 50-100 μm than the ServaNB1 collagenase digestion (P＜0.05),but the latter yielded more islets with a diameter range of 251-300 μm and 301-350μm (P＜0.05).There was no significant difference in total islets yields,viability,and GSI between two collagenase digestions (P＞0.05).Conclusion Both Vitacyte GOLD collagenase and Serva NB1 collagenase can be used for the clinical islet isolation in China.

Objective:To investigate the changes of β-cell dedifferentiation in type 2 diabetes mellitus(T2DM) and aging subjects.Methods:Using pancreatic samples from 12 prediabetic individuals, 21 type 2 diabetic patients, and 27 control, the level of β-cell dedifferentiation was assessed by immunofluorescence staining for FOXO1 and insulin expression. Correlation analyses were performed between β-cell dedifferentiation levels and hemoglobin A 1C(HbA 1C) level in 60 human pancreatic samples. Correlation analyses were performed between β-cell dedifferentiation levels and age in non-diabetic and T2DM. Results:FOXO1 was mainly expressed in the cytoplasm of human islet β-cells. The proportion of FOXO1 -INS + /INS + cells in T2DM significantly increased compared with control and pre-diabetes, and positively correlated with HbA 1C level( r=0.623, P<0.001). The proportion of FOXO1 -INS + /INS + cells in the young group of T2DM was significantly higher than that in the non-diabetic young and elderly groups, and further significantly increased in elderly group. In T2DM, the proportion of FOXO1 -INS + /INS + cells was positively correlated with age( r=-0.53, P<0.05). Conclusion:Hyperglycemia and aging lead to an increased level of β-cell dedifferentiation in T2DM.

Objective To investigate the influences of IL-17 on regulatory T ( Treg) cells during Chlamydia trachomatis infection. Methods Wild-type ( WT) C57BL/6 mice and IL-17-/- mice were in-tranasally injected with 1×103inclusion forming units (IFU) of Chlamydia muridarum (Cm) to establish the mouse model of Chlamydia trachomatis respiratory tract infection. Mouse spleen and lung single cells were prepared. The percentages of CD4+CD25+T and CD4+CD25+Foxp3+T cells were detected by flow cytome-try. Expression of Foxp3 and TGF-β at mRNA level in lung was detected by RT-PCR. The levels of IL-10 in bronchoalveolar lavage fluid samples were detected by ELISA. Results Compared with the WT mice, the IL-17-/- mice had higher percentages of CD4+CD25+T and CD4+CD25+Foxp3+T cells in spleen and lung on the third day of Cm infection. Both of the expression of Foxp3 at mRNA level in lung and the secretion of IL-10 in bronchoalveolar lavage fluid were increased in IL-17-/- mice as compared with those in WT mice. No significant difference in the expression of TGF-β at mRNA level in lung tissues was found between the two groups. Conclusion IL-17 might inhibit the proliferation of Treg cells and the secretion of IL-10 in the very early stage of Cm respiratory tract infection.