ObjectiveTo investigate the changes of peritoneal macrophages function of mice with gastric cancer in the CO2 pneumoperitoneum environment, as well as its effect on the peritoneal metastasis of gastric cancer. MethodsAn orthotopic implantation model of mouse forestomach cancer was established using the 615 mouse. The mice bearing tumors were randomly divided into five groups (n=30): anesthesia alone, laparotomy, and 2, 4, and 6 mm Hg CO2 insufflation groups. Peritoneal macrophages were collected from six mice in each group and cultured. The macrophage phagocytic function on neutral red and the levels of NO and TNF-α produced by macrophages were measured after 12, 24, 48, and 72 h of culture. The remaining mice were observed after two weeks for the rate of peritoneal metastasis of forestomach cancer cells and the total weight of implanted nodules. ResultsNo death and ascites were found and the difference of weight body was not significant in all mice (Pgt;0.05). The uptake of neutral red by peritoneal macrophages and the levels of NO and TNF-α secreted by peritoneal macrophages in the laparotomy group after 12 h of culture were all significantly higher than those in other four groups (Plt;0.05). The corresponding values in the 2, 4， and 6 mm Hg CO2 insufflation groups after 12 h were all significantly lower than those in the anesthesia alone group (Plt;0.05). Among three insufflation groups, the corresponding values in the 2 mm Hg after 12 h were significantly higher than those in the 4 and 6 mm Hg CO2 insufflation group, though the difference in the two latter was not significant (Pgt;0.05). The uptake of neutral red by peritoneal macrophages and the levels of NO and TNF-α secreted by peritoneal macrophages in the 6 mm Hg CO2 insufflation group after 24 h of culture were all significantly lower than those in other four groups (Plt;0.05), while the difference in the four groups was not significant (Pgt;0.05). The uptake of neutral red by peritoneal macrophages and the levels of NO and TNF-α secreted by peritoneal macrophages after 48 h and 72 h were not significantly different in the five groups (Pgt;0.05). The rate of peritoneal metastasis of mice was significantly lower in the 6 mm Hg insufflation CO2 group (75.0%, 15/20) than that in the anesthesia alone group (100%, 24/24), Plt;0.05, but higher than other three groups(Plt;0.05), which was not different in 2 mm Hg (47.8%, 11/23), 4 mm Hg insufflation group (45.45%, 10/22) and laparotomy group (50.0%, 10/20), Pgt;0.05. The total weight of implanted nodules of mouse forestomach cancer was (1.24±0.48) g, (1.02±0.38) g, (0.96±0.33) g, (0.93±0.45) g, and (1.18±0.37) g in the anesthesia alone group, the laparotomy group, and 2, 4, and 6 mm Hg CO2 insufflation group, and the difference was not significant (Pgt;0.05). ConclusionHigh pressure (6 mm Hg) CO2 pneumoperitoneum can constantly inhibit the phagocytosis and cytokine secretion functions of peritoneal macrophages in gastric cancer-bearing mice and promote peritoneal implantation of gastric cancer.
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.
ObjectiveTo investigate the effect of succinate induced polarization of MH-S murine alveolar macrophage cells on hyperoxia-induced epithelial-mesenchymal transition (EMT) of MLE-12 mouse alveolar epithelial cells. Methods Determine the exposure time: MLE-12 cells was cultured in an incubator with 95%O2 for different time to establish a cell model of acute hyperoxia-induced lung injury. The relative expression of EMT-related proteins (E-cadherin, N-cadherin, vimentin) was determined by Western blotting. Co-culture of MLE-12 and MH-S to explore the influence of MH-S on EMT: MLE-12 was divided into hyperoxia group for 0h, hyperoxia group for 48h and co-cultured with MH-S hyperoxia group for 48h (Co). The relative expression of EMT-related proteins was determined by Western blotting. Determination of succinate concentration and its effect on MH-S polarization and succinate receptor GPR91: MLE-12 was cultured in different concentrations of succinate medium for 24h, and the cell viability was determined by CCK-8. MH-S was divided into control group (C) and succinate group (S). Group C was cultured for 24h, and group S was added with succinate at the above concentration. The relative expression of GPR91 and polarization-related factor mRNA in MH-S was measured by RT-qPCR, and the expression of macrophage polarization-related proteins (CD11b, CD206, CD86) was measured by flow cytometry. Study on the effect of succinate on EMT by cell co-culture: MLE-12 and MH-S were co-cultured in a Transwell chamber and divided into control group (Co), succinate group (SUC) and GPR91 inhibitor group (I). Results Expression of EMT-related proteins in four groups of MLE-12 at different times: Compared with 0h, the expression of vimentin and N-cadherin in 24h and 48h increased, while the expression of E-cadherin in 48 h and 72 h decreased (P<0.05), and there was no significant difference in other groups. The follow-up experiment was conducted under hyperoxia conditions for 48h. Influence of MH-S on EMT: The expression of vimentin and N-cadherin in Co group was higher than that in 48h, and the expression of E-cadherin was lower than that in 48h (P<0.05). After 24 h of intervention with different concentrations of succinate on MLE-12, compared with the 0mmol/L, the cell viability of 2.5mmol/L, 1mmol/L and 500 μmol/L increased (P<0.05), and there was no significant difference in other groups, so the 1mmol/L succinate concentration was selected for subsequent experiment. Compared with group C, the expression of GPR91 mRNA in group S increased, and the expression of iNOS and CD86 mRNA in group S increased (P<0.05), but there was no significant difference in other groups. The analysis of flow cytometry showed that 1mmol/L succinate could increase the number and proportion of CD86+CD206– alveolar macrophages. Compared with Co group, the expression of vimentin and N-cadherin in SUC group increased, while the expression of E-cadherin decreased. Compared with SUC group, the expression of vimentin and N-cadherin in group I decreased, while the expression of E-cadherin increased (P<0.05). Conclusion Succinate can induce mouse alveolar macrophages polarization to M1 through GPR91, enhance EMT of mouse alveolar epithelial cell injury model under hyperoxia, and promote the formation of pulmonary fibrosis.
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.
Lung cancer has a high morbidity and mortality, and invasion is one of the major factors that cause recurrence and death in lung cancer patients. Tumor-associated macrophages (TAMs) are cells that have the potential to secrete cytokines, growth hormones, inflammatory substrates, and protein hydrolases, which are associated with the growth, invasion and metastasis of tumors. In this article, we will explore the various chemicals that are manufactured to promote the invasion of lung cancer, as well as the numerous clinical therapeutic features that TAMs possess in the treatment of lung cancer. In addition, we look at the possibility that TAMs might be beneficial in the treatment of lung cancer. We have an innovative investigation of the huge variety of complex substances generated by TAMs, with the goal of determining whether or not the molecules under investigation have the potential to serve as new therapeutic targets. Throughout the whole of the presentation, a significant focus is placed on doing in-depth research to ascertain whether TAMs have the capability to reinforce as viable carriers for unique and creative medications. This not only provides novel concepts for the creation of new targeted therapies but also leads to the development of brand-new, cutting-edge methods for the manufacture of individualized medicines and drug carriers.
ObjectiveTo study the effect and mechanism of lipopolysaccharide (LPS) on osteoclasts formation and its bone resorption function.MethodsBone marrow-derived macrophages (BMMs) were extracted from the marrow of femur and tibia of 4-week-old male C57BL/6 mice. Flow cytometry was used to detect BMMs. The effect of different concentrations of LPS (0, 100, 200, 500, 1 000, 2 000 ng/mL) on BMMs activity was examined by cell counting kit 8 (CCK-8) activity test. In order to investigate the effect of LPS on osteoclastogenesis, BMMs were divided into macrophage colony-stimulating factor (M-CSF) group, M-CSF+receptor activator of nuclear factor κB ligand (RANKL) group, M-CSF+RANKL+50 ng/mL LPS group, M-CSF+RANKL+100 ng/mL LPS group. After the completion of culture, tartrate resistant acid phosphatase (TRAP) staining was used to observe the formation of osteoclasts. In order to investigate the effect of LPS on the expression of Connexin43, BMMs were divided into the control group (M-CSF+RANKL) and the LPS group (M-CSF+RANKL+100 ng/mL LPS); and the control group (M-CSF+RANKL), 50 ng/mL LPS group (M-CSF+RANKL+50 ng/mL LPS), and 100 ng/mL LPS group (M-CSF+RANKL+100 ng/mL LPS). The expressions of Connexin43 mRNA and protein were detected by Western blot and real-time fluorescent quantitative PCR, respectively. In order to investigate the effect of LPS on osteoclast bone resorption, BMMs were divided into M-CSF group, M-CSF+RANKL group, M-CSF+RANKL+50 ng/mL LPS group, and M-CSF+RANKL+100 ng/mL LPS group. Bone absorption test was used to detect the ratio of bone resorption area.ResultsThe flow cytometry test confirmed that the cultured cells were BMMs, and CCK-8 activity test proved that the 100 ng/mL LPS could promote the proliferation of BMMs, showing significant differences when compared with the 0, 200, 500, 1 000, and 2 000 ng/mL LPS (P<0.05). TRAP staining showed no osteoclast formation in M-CSF group. Compared with M-CSF+RANKL group, the osteoclasts in M-CSF+RANKL+50 ng/mL LPS group and M-CSF+RANKL+100 ng/mL LPS group were larger with more nuclei, while the osteoclasts in M-CSF+RANKL+100 ng/mL LPS group were more obvious, and the differences in the ratio of osteoclast area between groups were statistically significant (P<0.05). Western blot result showed that the relative expression of Connexin43 protein in LPS group was significantly higher than that in control group (P<0.05). Real-time fluorescent quantitative PCR showed that the relative expression of Connexin43 mRNA in control group, 50 ng/mL LPS group, and 100 ng/mL LPS group increased gradually, and the differences between groups were statistically significant (P<0.05). Bone resorption test showed that osteoclast bone resorption did not form in M-CSF group, but the ratio of bone resorption area increased gradually in M-CSF+RANKL group, M-CSF+RANKL+50 ng/mL LPS group, and M-CSF+RANKL+100 ng/mL LPS group, and the differences between groups were statistically significant (P<0.05).ConclusionLPS at concentration of 100 ng/mL can promote the expression of Connexin43, resulting in increased osteoclastogenesis and enhanced osteoclastic bone resorption.
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 understand the interplay between tumor-associated macrophages (TAMs) and T lymphocytes, as well as the effect on the pathogenesis of hepatocellular carcinoma (HCC) again, so that providing new ideas and methods for the immunotherapy of HCC.MethodSearched the literatures about the interplay between TAMs and T lymphocytes in HCC to analyze and summarize the relationship between TAMs and T lymphocytes in HCC.ResultsWhile TAMs and T lymphocytes themselves regulate the process of tumorigenesis and development, they also had a mutual regulatory mechanism to further promote the development of HCC.ConclusionsThere is an interaction between TAMs and T lymphocytes, and this interaction forms a vicious circle to a large extent and promotes the development of HCC. Recognizing and making rational use of this interaction can provide new ideas and methods for the future immunotherapy of HCC.
Acute pancreatitis (AP) is a gastroenterological emergency with an acute onset and a high mortality rate. The main pathogenesis of AP is pancreatic damage and excessive activation of inflammatory cells induced by multiple factors. Due to anatomical features, the liver is the first extrapancreatic organ to be attacked by high concentrations of trypsin and inflammatory mediators during AP. Hepatic macrophages have been shown to be a major source of AP-related inflammatory factors. Interventions targeting hepatic macrophages may be critical to block liver injury/failure during AP, promote tissue repair, and reduce systemic symptoms. This review summarizes the pathological role of hepatic macrophages in AP and targeted interventions to provide new ideas and approaches to resolve the pathogenesis of AP and alleviate concurrent liver injury.
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.