ObjectiveTo investigate the effect of graphene oxide (GO)-carboxymethyl chitosan (CMC) hydrogel loaded with interleukin 4 (IL-4) and bone morphogenetic protein 2 (BMP-2) on macrophages M2 type differentiation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs).MethodsGO solution was mixed with CMC, then the phosphate buffered saline (PBS), IL-4, BMP-2, or IL-4+BMP-2 were added to prepare different GO-CMC hydrogel scaffolds with or without different cytokines under crosslinking agents. The characteristics of pure GO-CMC hydrogel were characterized by gross observation, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR), and the CMC hydrogel was used as control. The sustained release of GO-CMC hydrogels with different cytokines was also tested. Macrophages were isolated and cultured from female Sprague Dawley rats aged 4-5 weeks, and then cultured with GO-CMC hydrogels with and without different cytokines, respectively. CD206 immunofluorescence staining was used to detect the differentiation of macrophages after 24 hours. The 3rd generation of rats BMSCs were cultured with GO-CMC hydrogels with and without different cytokines respectively for osteogenic induction. The early osteogenesis was observed by alkaline phosphatase (ALP) staining after 10 days, and the late osteogenesis was observed by alizarin red staining after 21 days.ResultsGenerally, GO-CMC hydrogel was brown and translucent. SEM showed that the pore diameter and wall thickness of GO-CMC hydrogel were similar to that of CMC hydrogel, but the inner wall roughness increased. FTIR test showed that CMC polymerized to form hydrogel. In vitro, the sustained release experiments showed that the properties of GO-CMC hydrogels loaded with different cytokines were similar. CD206 immunofluorescence detection showed that GO-CMC hydrogels could induce macrophages differentiation into M2-type. ALP and alizarin red staining showed that GO-CMC hydrogels could induce BMSCs osteogenic differentiation, in which GO-CMC hydrogel loaded with IL-4+BMP-2 showed the most significant effect (P<0.05).ConclusionThe GO-CMC hydrogel loaded with IL-4 and BMP-2 can induce macrophages differentiation into M2-type and enhance the ability of BMSCs with osteogenic differentiation in vitro, which provide a new strategy for bone defect repair and immune regulation.
ObjectiveTo compare the different effects of ubiquitin(UB) on human umbilical vein endothelial cells (HUVECs) and macrophages under normal circumstances,and analyze whether UB could protect HUVECs from lipopolysaccharide(LPS) induced injury.
MethodsThe morphologic changes of HUVECs in vitro with up-rising concentrations of UB interventions were observed. HUVECs and human macrophages in vitro were divided into 4 groups according to UB concentration (0.01 μg/mL,0.1 μg/mL, 1 μg/mL, and 10 μg/mL). Supernatant and cells of each group were collected in 24 h after UB intervention. The levels of TNF-α and VCAM-1 in supernatant were measured by ELISA while NF-κB protein level in cells was detected by Western blot. HUVECs were divided into a LPS group(LPS 10 μg/mL) and an UB+LPS group(UB 0.1 μg/mL,LPS 10 μg/mL). The supernatant of the two groups were collected in 8,16 and 24 h after LPS and UB intervention. The levels of TNF-α and VCAM-1 in supernatant were measured by ELISA.
ResultsThe injury of HUVECs got worse with the ascending concentrations of UB.At the concentration of 50 μg/mL,UB induced HUVECs got ballooned and died massively. With the increase of UB concentration,the levels of TNF-α and VCAM-1 in HUVECs' supernatant ascended firstly and then descended,while those in human macrophages' supernatant ascended gradually. zHowever,the tendency of the NF-κB protein level in the two kinds of cells was similar when the concentration of UB increased.At the consentration of 0.1 μg/mL or 1 μg/mL,ubiquitin induced NF-κB protein level obviously increased.At the concentration of 0.01 μg/mL or 10 μg/mL,UB induced the protein level was similar with those of the control group and even decreased slightly. There was no significant difference in TNF-α or VCAM-1 levels at each time point between the LPS group and the UB+LPS group.
ConclusionsUB injuries HUVECs obviously at a low concentration but injuires human macrophages at much higher concentraton. UB can not protect HUVECs from LPS-induced injury in vitro.
Objective To investigate the role of alveolar macrophages ( AMs ) in airway inflammation of smoke-induced COPD rat model and its possible regulating mechanism. Methods Twelve Wistar rats were randomly divided into a COPD group and a control group. The rat model of COPD was established with smoke exposure and LPS intrathacheal instillation. Bronchoalveolar lavage fluid ( BALF)was collected for measurement of total and differential cell counts. Then AMs were isolated and identified byimmunofluorescence. Western blot was employed to analyze the cytoplasmic and nuclear NF-κB p65 expression of AMs. The concentrations of TNF-α,macrophage inflammatory protein 2 ( MIP-2) and IL-10 in cell culture supernatantwere assayed by ELISA.Results The scores of bronchitis and mean liner intercepts in the COPD group were significantly higher than those in the control group [ 4. 33 ±1. 16 vs. 1. 33 ±0. 58,P =0. 016; ( 168. 77 ±11. 35) μm vs. ( 93. 61 ±4. 16) μm, P = 0. 000) ] . The total cell count in BALF of the COPD group was significantly higher than that in the control group ( P lt; 0. 05) , and the AMs and neutrophils were predominant [ ( 72. 00 ±2. 22) % and ( 18. 29 ±8. 34) % ] . The cytoplasmic NF-κB p65 expression of AMs in the COPD group was significantly lower , while the nuclear NF-κB p65 expression was significantly higher ( P lt; 0. 05) compared with the control group. The ELISA results showed that the concentrations of TNF-αand MIP-2 in culture supernatant of AMs in the COPD group were significantly higher than those in the control group ( P lt;0. 05) , while the concentration of IL-10 was not significantly different between the two groups ( P gt;0. 05) . Conclusions COPD rat model was established successfully with smoke exposure and LPS intratracheal instillation with a profile of macrophage-based chronic inflammation and increased secretion of TNF-αand MIP-2. The mechanismis closely related to activation of NF-κB.
Objective To explore the role of macrophage-stimulating protein ( MSP) and receptor tyrosine kinase RON in the airway inflammation of chronic obstructive pulmonary disease( COPD) , and investigate its possible mechanism. Methods The rat COPDmodel was established by exposing the rats to cigarette smoke daily for three months. Rat alveolar macrophages ( AMs) were isolated in vivo and cultured,and then challenged with different concentrations of MSP for 24 hours. The concentrations of MSP in broncho-alveolar lavage fluid ( BALF) and serum, and the levels of IL-1β, TNF-α, IL-8, and IL-10 in the supernatants were measured by ELISA. The expression of RONmRNA in lung tissue was assessed by reverse transcription-polymerase chain reaction. The levels of RON protein in the lung tissue and AMs cultured in vitro were observed by immunohistochemistry. The activity of superoxide dismutase ( SOD) and malondialdehyde ( MDA) content in the culture solution were measured with chromatometry method. Results Compared with the control group, the concentrations of MSP in serum and BALF of the COPD rats were significantly higher ( P lt;0. 01) . The levels of RONmRNA and RON protein in the COPD rats were also upregulated significantly ( P lt; 0. 01) . MSP evoked the AMs isolated from the normal and COPD rats to generate more content of MDA and caused a reduction in activity of SOD. In addition, MSP stimulated TNF-α, IL-8, IL-1βand IL-10 release fromAMs of the normal and COPD rats dose-dependently. The levels of TNF-α, IL-8, and IL-1βwere higher, while the level of IL-10 and the SOD activity were lower in AMs of the COPD group than those of the control group in the same dose of MSP ( P lt;0. 01) . The more significant increase in the levels of TNF-α, IL-8, IL-1β, and the more notable decrease in the activity of SOD was found in the COPD group compared with the control group. But the degree of increasing MDA and IL-10 in the AMs of the COPD group was lower than that in the control group. Linear correlation analysis showed that the MSP concentration and the RON protein level in the COPD rats were positively associated with the total cellcounts and AM counts in BALF, and were related to the indexes for pulmonary emphysema. Conclusions There is a close correlation between the MSP and receptor tyrosine kinase RON with the airway inflammation of COPD. The mechanism might be that MSP promote the macrophages release inflammatory factors and increase the production of oxygen free radicals.
ObjectiveTo investigate the expressions of microRNA-155 (miR-155) in different phenotypes of activated macrophages.
MethodsThe THP-1 cells underwent polarized activation into M1, M2 or tumor-associated macrophages (TAMs), and the phenotypes were confirmed by flow cytometry. The miR-155 expression was determined by qRt-PCR in M1 macrophages, M2 macrophages and TAMs.
ResultsThe miR-155 expression significantly decreased in the M2 macrophages (1.83±0.337, P=0.000), TAMs (1.60±0.233, P=0.000) compared with the M1 (6.580±0.637). The phenotype of TAMs was similar to M2. There was no statistically significant difference between TAMs and M2 macrophages in the expression of miR-155 (P=0.546).
ConclusionDifferent expressions of miR-155 in macrophages M1-type and M2-type may be associated with the differentiation or their cellular functions. The phenotypic characteristics TAMs may transform to macrophages to M2-type. And they may have the same functions.
ObjectiveTo establish a methodology for alveolar macrophages (AMs) phagocytosis of AlexaFluor 488 (AF488) labeled bacteria by flow cytometry.MethodsStaphylococcus aureus and Streptococcus pneumoniae were labeled with different concentrations of AF488. A flow cytometric assay was used to quantify in vivo bacterial uptake by AMs. AMs and different ratio of fluorescent-labeled bacteria were incubated at 37 ℃ for 2 hours, 4 hours, 6 hours and 8 hours, respectively. AMs were washed with DPBS and extracellular fluorescence was quenched with 1% (w/v) trypan blue. Trypan blue was aspirated and phagocytosis of fluorescent-labeled bacteria by AMs was measured using a flow cytometry. Confocal microscopy was performed to ensure that bacterial in positive AM had been internalized rather than bound to the cell surface.ResultsWhen the concentration of AF488 was more than 50 μg/mL, the labeling rates of Staphylococcus aureus and Streptococcus pneumoniae were higher than 92% (P<0.05), and has quickly reached the upper limit. With the prolongation of incubation time, the phagocytic rate of AMs increased from 20.4% at 2 hours to 76.5% at 8 hours. With the increase in the number of bacteria, the phagocytic rate of AMs increased from 7.7% by ratio of 1∶10 to 85.1% by ratio of 1∶300.ConclusionDetection of AMs phagocytosis of AF488 labeled bacteria by flow cytometry is an effective method, but the dye concentration, incubation time and the proportion of bacteria will influence the results.
Objective To explore the expression of myeloid differentiation protein2 ( MD-2) in rat lung and its role in acute lung injury ( ALI) induced by lipopolysaccharide ( LPS) . Methods Twenty male SD rats were randomly divided into a LPS group and a control group. The wet/dry ratios of lung tissues were measured and the histological changes of lung tissues were observed under microscope. Alveolar macrophages were collected from bronchial alveolar lavage fluid ( BALF) . The MD-2 mRNA and protein expressions were detected by RT-PCR, Western blot, and immunohistochemistry respectively. The MD2-siRNA oligo were transfected into NR8383 cells and 1 μg/mL LPS was used to stimulate the cells. The expressions of MD-2 mRNA and protein were detected by RT-PCR and Western blot. The levels of TNF-αin rat serum and cell culture supernatant were detected by ELISA. Results Compared with the control group, the expressions of MD-2 mRNA and protein in alveolar macrophages and lung tissue were elevated ( P lt;0. 01) , as well as the level of TNF-αin rat serum. The expressions of MD-2 mRNA and protein in NR8383 cell and the level ofTNF-αin supernatant increased obviously after LPS stimulation ( P lt;0. 01) . There were no changes of MD-2 mRNA and protein expressions and TNF-α of NR8383 cells treated by MD-2 siRNA with or without LPS stimulation ( P gt;0. 05) . Conclusions The expression of MD-2 in lung increases obviously after challengedby LPS. KnockdownMD-2 gene of NR8383 cell byMD-2 siRNA can inhibit TNF-αsecretion induced by LPS stimulation.MD-2 may play an important role in rat ALI induced by LPS.
In the tumor microenvironment, tumor-associated macrophage, as polarized macrophages M2 phenotype, can promote tumor progression and affect the prognosis of cancer. Significant attention has been drawn towards tumor-associated macrophage in recent years. In this review, we describe the polarization state of macrophages determined by tumor microenvironment and the recruitment of tumor-associated macrophage. We also pay special attention to the interaction between tumor-associated macrophages and tumors, discuss and summarize various targeted therapy strategies for tumor-associated macrophages, aiming to provide a reference for the future development of these novel and effective anti-cancer treatments.
Objective To explore the association of macrophages with carcinogenesis and development of gastric cancer. Method The related literatures at home and abroad were consulted and reviewed. Results The microenvironment of gastric cancer could induce the polarization of macrophages，and then the activated macrophages，especially the tumor associated macrophages，could in turn motivate the growth，invasion，and metastasis of tumor cells by secreting a series of active substances. Conclusions Macrophages，especially the tumor associated macrophages play an importantrole in the carcinogenesis and development of gastric cancer. Investigating the macrophages and their interaction with gastric cancer may lead to a profound understanding of carcinogenesis of gastric cancer as well as opening up a new prospectfor treatment.
ObjectiveTo investigate the effect of miR-190a-5p on the polarization of bone-marrow-derived macrophage (BMDM) induced by lipopolysaccharides to M1- and M2-types.MethodsBMDM (M1-type) induced by bacterial lipopolysaccharide was a M1 group. The macrophage M1-type interfered with negative control miRNA mimics was a NC group. miR-190a-5p mimics interfered with the M1-type of macrophages in the miR-190a-5p group. Morphological changes of macrophages were observed under a microscope, and the proportion of M2-type macrophages (CD206+, F4/80) was detected by flow cytometry. The mRNA expression levels of argininase-1 (Arg1), inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), target gene C/EBPα and PU.1 were detected by fluorescence quantitative PCR to verify whether C/EBPα and PU.1 were potential target genes of miR-190a-5p. The expression of pathway proteins C/EBPα and PU.1 were detected by Western blotting.ResultsAfter miR-190a-5p mimics interfered with macrophage M1-type, the antenna of macrophages elongated and showed long cord M2-type cell morphological characteristics. miR-190a-5p mimics interfered with M1-type macrophages for 24 h, and the percentage of M2-type macrophages increased significantly (P<0.05). Effects of miR-190a-5p simulator on mRNA expression levels of M1-type macrophages included: the expression of iNOS and TNF-α was significantly decreased (P<0.05), the expression of Arg1 marked by M2 macrophages was significantly increased (P<0.05), and the mRNA expression levels of target genes C/EBPα and PU.1 were significantly decreased (P<0.05). Western blotting results showed that the overexpression of miR-190a-5p significantly inhibited the protein expressions of C/EBPα and PU.1, while the miR-190a-5p inhibitor increased the expressions of both proteins.ConclusionmiR-190a-5p can promote the polarization of BMDM from M1-type to M2-type.
