Isolation,Purification and Differentiation of Hematopoietic Stem Cells into Dendritic Cells in Mouse Lung Tissue / 中国实验血液学杂志

OBJECTIVE@#To explore the method of isolation, purification and differentiation of hematopoietic stem cells (HSCs) into dendritic cells (DC) in lung tissue of mouse, so as to provide theoretical basis and experimental methods for the study of hematopoietic stem cells in mouse lung tissue.@*METHODS@#Lung tissues of 4 male C57 mice were digested, separated and purified into mononuclear cells by type I collagenase, type I DNA enzyme and lymphocyte isolation solution. LinSca-1c-Kit cells, which are hematopoietic stem cells (HSCs) were identified and sorted by flow cytometry. Stem cell factor (SCF) and interleukin 3 (IL-3) were added in the obtained HSCs to promote cell proliferation. After discontinuation of SCF and IL-3, granulocyte-macrophage colony stimulating factor (GM-CSF) and IL-4 were added to induce differentiation of HSCs into DCs, and lipopolysaccharide (LPS) was added to promote cell maturation. The morphology of DCs was observed under inverted microscope, the expression of CD80, CD86, CD11c and MII-II on the surface of DCs was analyzed by flow cytometry, and the expression level of IL-12 was detected by enzyme-linked immunosorbent assay (ELISA).@*RESULTS@#2419.67±247.59 HSCs were collected from lung tissue mononuclear cells of 4 mice identified by flow cytometry with purity: (7.16±0.43)%. HSCs were amplified 62.34±3.23 times by induction with SCF and IL-3 for 7 days. After induction culture for 15 days, mature dendritic cells were obtained with typical dendrites on the cell surface, the DC expressed dendritic cell-specific surface molecules CDllc (92.62±3.68)%,MHC-II (83.89±6.28)%， CD80 (75.96±5.13)%, CD86(72.07±4.38)%, and the expression level of IL-12 was 136.12±16.59 pg/ml detected by ELISA.@*CONCLUSION@#There are HSCs in lung tissue, which can be transformed into DCs by cytokine induction and proliferation.

Advanced glycated albumin induces macrophage pyroptosis via upregulating nucleotide-binding oligomerization domain-like receptor protein 3 / 生理学报

The purpose of the present study was to investigate the effect of advanced glycated albumin (AGE-alb) on pyroptosis of macrophages and the underlying molecular mechanisms. RAW264.7 macrophages were treated with AGE-alb (1, 2, 4 and 6 g/L) and control albumin (C-alb, 4 g/L) for 24 h, or preincubated with MCC950 (1 μmol/L) for 1 h and then treated with AGE-alb (4 g/L) for 24 h. Cell viability and caspase-1 activity were measured by MTT and assay kits, respectively. Lactate dehydrogenase (LDH) activity and the levels of interleukin-1β (IL-1β) and IL-18 in media were detected. Cell death degree was evaluated by TUNEL and Hoechst 33342/PI staining. The protein levels of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), procaspase-1 and cleaved caspase-1 were assessed by Western blot. The results showed that AGE-alb treatment caused obvious decrease in cell viability and increases in LDH leakage and the percentages of TUNEL- or PI-positive cells in a concentration-dependent manner. Additionally, AGE-alb promoted IL-1β and IL-18 secretion, upregulated NLRP3 expression, and increased caspase-1 activity especially at the dose of 4 and 6 g/L. However, MCC950 (an NLRP3 inhibitor) pretreatment inhibited significantly the decrease in cell viability and the increases in LDH leakage and percentages of TUNEL- or PI-positive cells induced by AGE-alb. Furthermore, MCC950 attenuated obviously AGE-alb-induced IL-1β and IL-18 secretion and caspase-1 activation. These results indicate that AGE-alb may induce macrophage pyroptosis, and the mechanism is at least partially by activating NLRP3-caspase-1 pathway.