ObjectiveTo investigate the role of Krüppel-like factor 4 (KLF4) mediated monocyte/macrophage subtype switch in the pathological progression of pulmonary fibrosis.MethodsThirty-six patients with interstitial pneumonia were recruited from Characteristic Medical Center of the Chinese People's Armed Police Force between May 2015 and January 2017. Peripheral venous blood and bronchoalveolar lavage fluid were collected in the morning. Pulmonary function and arterial blood gas were tested after admission. Flow cytometry was used to test monocyte subtypes of peripheral blood and macrophage subtypes of bronchoalveolar lavage fluid. KLF4 of peripheral blood was detected by enzyme linked immunosorbent assay. Thirty normal subjects were selected as control group of peripheral blood mononuclear cell subtypes and KLF4 (control group A), and 10 patients without pulmonary fibrosis who needed bronchoscopy were selected as control group of macrophage subtypes in alveolar lavage fluid (control group B). The relationship between the expression of KLF4 and the differentiation of monocytes and macrophages were observed. Furthermore, the relationship between the differentiation of monocytes subtypes, macrophages subtypes and lung function were observed.ResultsMonocyte of CD14++CD16– subtype in pulmonary fibrosis group was significantly lower than that in control group A (P<0.05). Monocyte of CD14++CD16+ subtype in pulmonary fibrosis group was significantly higher than that in control group A (P<0.05). No significant difference was found between the two groups regarding CD14+CD16++. No correlation was found between three subtypes of monocyte and DLCO of patients and between three subtypes of monocyte and PaO2 of patients. M1 macrophage in pulmonary fibrosis group was significantly lower than that in control group B (P<0.05). M2 macrophage in pulmonary fibrosis group was significantly higher than that in control group B (P<0.05). Negative correlation was found between the ratio of M2 subtypes and DLCO of patients and between the ratio of M2 subtypes and PaO2 of patients (P<0.05). KLF4 protein of blood in pulmonary fibrosis group was significantly higher than that in control group A (P<0.05). Positive correlation was found between the ratio of M2 subtypes and KLF4 protein (P<0.05).ConclusionsCD16+ monocyte plays a role in the occurrence and development of pulmonary fibrosis, but no evidence is found there is a direct correlation between monocyte subtypes of peripheral blood and fibrosis degree of lung tissue. M2 macrophage subtype plays an important role in the development of interstitial pneumonia. The number of M2 macrophages is positively correlated with the severity of pulmonary fibrosis. Monocyte/macrophage subtype differentiation by KLF4 may play a role in the pathological progression of pulmonary fibrosis.
Objective To study the effect of water soluble chitosan (WSC) on the apoptosis of peritoneal macrophage induced by lipopolysaccharides (LPS), and discuss the mechanism. Methods Peritoneal macrophages were divided to three groups: phosphate buffered saline (PBS) group, LPS group and LPS plus WSC group. At hour 24, apoptosis cell and active caspase-3 were detected by flow cytometry; nitric oxide (NO) was determined with Griess reagent. Results There were more apoptosis cells in the LPS group than the PBS group. The percentage of apoptosis cells was significantly decreased in the LPS plus WSC group than the LPS group. The expression of active caspase-3 and the secretion of NO were also inhibited by WSC after LPS intervention. Conclusion WSC inhibits apoptosis of peritoneal macrophage induced by LPS.
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.
Objective To explore the effects of several immunosuppressants on the cell numbers of cultured rat macrophages and Schwann’s cells. Methods The macrophages and Schwann’s cells were cultured from the newborn Wistar rats. Different concentrations of methylprednisolone(10-3, 10－4,10－6 and 10－8 mol/L), CsA(10－5, 10－6, 10－7 and 10－8 mol/L) and FK506(10-6, 10－7, 10－8 and 10－9 mol/L) were administrated to the cells, while control group was given no drugs. Twentyfour, 48 and 72 hours after administration, the cells from different concentrations were measured with MTT methods respectively. Theresults were compared and analyzed statistically. Results Only high concentration methylprednisolone (10-4 mol/L) and a certain range of concentrations of CsA (10-6，10-7 and 10-8 mol/L) and FK506 (10-7,10-8 and 10-9 mol/L) can provide protection to culturedrat macrophages. Under most concentrations, CsA and FK506 had no effects onthe cell number of cultured rat Schwann’s cell. Only with high concentration CsA (10-5 mol/L) and methylprednisolone (10-3 mol/L) could significantly decreased the cell number of Schwann’s cell. Long time (72 hours) and low dosage (10-8 mol/L) administration of methylprednisolone could significantlyprotect Schwann’s cell. Conclusion High concentration methylprednisolone and some certain concentration CsA and FK506 can protect cultured rat macrophages. But high concentration CsA and methylprednisolone prohibit the proliferation of Schwann’s cells. Only long time and low dosage methylprednisolonecan protect cultured rat Schwann’s cells.
ObjectiveTo investigate the changes of inflammatory cytokines in bronchoalveolar lavage fluid (BALF) in rats exposed to paraquat (PQ). MethodsAdult healthy SD rats were randomly divided into a control group (n=8) and three experimental groups (PQ in low dosage of 15 mg/kg,medium dosage of 30 mg/kg,and high dosage of 60 mg/kg,n=24 in each group). The rats in three experimental groups were intragastrically administered with PQ,and the rats in the control group were treated with saline by gavage. Two rats in the control group and six rats in three experimental groups were sacrificed on 1st,7th,14th,and 21st day after exposure respectively. BALF was collected for measurement of interleukin-1(IL-1),IL-6,macrophage inflammatory protein-2(MIP-2),monocyte chemoattractant protein-1(MCP-1),and biopterin by ELISA. ResultsThe levels of cytokines in all experimental groups were higher than those in the control group at any time point. In the exposure day 1 to day 14, IL-1 and biopterin levels in BALF increased significantly with the increase in PQ dose. On 14th and 21st day,IL-6 level in BALF increased significantly with the increase in PQ dosage. The levels of IL-1,IL-6,and biopterin in the experimental groups reached the peak on 14th day. On 14th day,the MIP-2 level in BALF of high-dosage group was significantly higher than that of low-dosage and medium-dosage groups (all P<0.05). The level of MCP-1 in the low-dosage group was lower than that in the medium-dosage and high-dosage groups at any time point (P<0.05). ConclusionIL-1,IL-6,MIP-2,MCP-1,and biopterin may play important roles in the development and progression of PQ-induce lung inflammation.
Objective To study the effect of pravastatin on the survival of islet xenografts.MethodsPigtomouse islet transplantation was performed. The models were divided into 4 groups: group A (control); group B, treated with CsA; group C, treated with pravastatin; group D, treatment with combined CsA with pravastatin. The survival time (ST) of the grafts in each group were recorded. Histological examination was used to detect the inflammation and islet cells in the graft. The infiltrated cells were detected by immunohistochemistry with CD4+, CD8+ and CD68 monoclonal antibody. The serum NO was measured. RTPCR was used in the test of IFNγ mRNA.ResultsThe ST of group A,B,C,D was (6.2±0.82) d, (9.2±1.92) d, (7.2±1.30) d, (11.2±1.76) d respectively, the ST of group D was much longer than that of the other groups (P＜0.05).Compared to that in other groups, less infiltrated cell in group D was found. On the 4th postoperative day, the serum NO in group A was (105.0±19.3) mmol/L,significantly higher than that in group B 〔(88.20±21.04) mmol/L〕, in group C 〔(70.7±17.8) mmol/L)〕 and in group D 〔(56.30±16.4) mmol/L〕. When rejection occurred, the serum NO in group C and D was (83.7±10.6) mmol/L and (71.3±13.8) mmol/L, also lower than that in group A (P＜0.05), the serum NO in group B was (104.7±16.3) mmol/L, compared that in group A, no significance was present (Pgt;0.05）. On the 4th postoperative day, the serum expression of IFNγ mRNA in group D was 23.5±4.6, lower than that in group A (28.8±4.8), and no significance was present compared with that in group B and C. ConclusionPravastatin can abate the role of macrophages, especially combined with Cyclosporine, and can prolong the survival of islet xenograft.
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.
Scavenger receptor CD36 is a transmembrane protein as well as pattern recognition receptor expressed on the surfaces of multiple types of cells such as monocytes, macrophages, microvascular endothelial cells, smooth muscle cells, and platelets. In recent years, studies have found that the expression of CD36 is increased in some diseases, including type 2 diabetes, atherosclerosis, non-alcoholic fatty liver, and obesity. This paper collates the latest progress in the studies of scavenger receptor CD36, illuminates the role of CD36 receptor in metabolic inflammatory diseases by inflammation control, endoplasmic reticulum stress, macrophage phenotype transformation, and insulin resistance, and briefly introduces that CD36 can be a serum marker of metabolic inflammatory diseases, in order to provide potential therapeutic targets for treatment of metabolic inflammatory diseases.
Objective To investigate the role of macrophage stimulating protein (MSP) in the pathogenesis of chronic obstructive pulmonary disease (COPD). Methods Ninety subjects were recruited from health examination center, outpatient or inpatient department in Affiliated Hospital of North Sichuan Medical College from July 2013 to December 2013. They were divided intoahealthy control group, a stable COPD group, and an acute exacerbation of COPD (AECOPD) group with 30 subjects in each group. The levels of MSP, interleukin-6 (IL-6), IL-8 and tumor necrosis factor-α (TNF-α) in the plasma of all subjects, as well as the levels of MSP in the induced sputum of the AECOPD and the stable COPD patients were assessed by enzyme-linked-immuno-sorbent assay. Results The concentrations of MSP, IL-6, IL-8 and TNF-α in the plasma of the patients with COPD were obviously higher than those of the healthy controls (P<0.05) while much higher in AECOPD patients than those in stable COPD patients (P<0.01).The concentration of MSP in the induced sputum of the patients with AECOPD was higher than that in the stable COPD patients (P<0.01). The concentrations of MSP in the serum and induced sputum as well as serum levels of IL-6, IL-8 and TNF-α in the patients with COPD were negatively correlated with the level of FEV1%pred. The concentrations of MSP in the serum and induced sputum in the COPD patients were positively correlated with the concentrations of IL-6, IL-8 and TNF-α. Conclusions The concentrations of serum and induced sputum MSP, and the serum concentrations of IL-6, IL-8 and TNF-α in COPD patients are related to the severity of the disease. MSP may play an important role in the pathogenesis of COPD. The mechanism might be mainly involved in the regulation of airway inflammation.
Objective To study the effect of mechanical stretch on the microenvironment of BEAS-2B on macrophage polarization and the role of polarized macrophages in the epithelial-mesenchymal transition (EMT) of BEAS-2B. Methods Using enzyme linked immunosorbent assay to detect the changes in the levels of cytokines such as interferon-γ, granulocyte-macrophage colony stimulating factor, tumor necrosis factor-α, interleukin (IL)-4, IL-6, IL-10 in the supernatant of lung epithelial cells cultured statically and mechanically stretched. The M0 macrophages (derived from THP-1) were stimulated by stretch/static conditioned medium of BEAS-2B. The surface markers of M1 (CD197) /M2 (CD206) macrophages were detected by flow cytometer. Stretch/static conditioned medium were used to stimulate the co-culture system of macrophages and BEAS-2B in the presence or absence of platelet-derived growth factor receptor inhibitor (PDGFRi), then the protein expression level of EMT makers was examined by Western blot. Results Exposure of BEAS-2B to mechanical stretch resulted in significantly higher production of the pro-M1/M2 polarized factor. The EMT of the co-culture system of M0 and BEAS-2B could be induced by stretch conditioned medium, epithelial marker cytokeratin (CK)-8 and E-cadherin were decreased, while mesenchymal marker α-smooth muscle actin, N-cadherin and vimentin were increased in stretch conditioned medium group. The expression of platelet-derived growth factor (PDGF) was significantly higher in stretch conditioned medium group. The PDGFRi can block the EMT in stretch conditioned medium group. Conclusions The lung epithelial cell supernatant induced by mechanical stretch can promote the polarization of macrophages to M1 and M2. Polarized macrophages promote EMT in human lung epithelial cells via PDGF, and blocking PDGF might attenuate the VILI-associated lung fibrosis.