Effect of histone H4 on polarization of alveolar macrophages in mice with acute respiratory distress syndrome / 中国职业医学

Objective To investigate the role of histone H4 in the polarization of alveolar macrophages (AM) in lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) in mice. Methods i) The specific pathogen free male C57BL/6 mice were randomly divided into control group and 2, 4, 6 and 8 mg/kg LPS groups, with six mice in each group. The mice in the LPS groups were intratracheally administered LPS according to their respective doses, while the mice in the control group received an equivalent volume of 0.9% saline. After 12 hours, the arterial blood gas was analyzed, and the pulmonary edema and histopathological changes in lung tissues of mice in each group were observed. The level of histone H4 in bronchoalveolar lavage fluid (BALF) of mice was detected using enzyme-linked immunosorbent assay , and mice AMs of the five group were isolated using adherent method. ii) AMs from normal mice were isolated using adherent method and randomly divided into control group, histone H4 injury group, BALF injury group and anti-histone H4 antibody (anti-H4) intervention group. In the histone H4 injury group, AMs were treated with histone H4 at a final concentration of 20 mg/L. In the BALF injury group and anti-H4 intervention group, AMs were treated with 200 μL BALF supernatant from mice intratracheally administered 6 mg/kg body weight LPS, with the latter group treated with 25 mg/L anti-H4 antibody. The control group AMs were treated with phosphate-buffered saline. iii) After 12 hours of stimulation, the cells were collected, and the relative expression of tumor necrosis factor-α (Tnfa), interleukin-1β (Il1b), differentiation antigen 206 (Cd206) and arginase 1 (Arg1) in AMs was detected using real-time quantitative polymerase chain reaction. Results i) Compared with the control group, mice in all four LPS groups exhibited rapid breathing, inflammatory reaction and lung edema in lung tissues, which were aggravated in a dose-dependent manner. The ratio of partial pressure of arterial oxygen to fraction of inspired oxygen in mice decreased with the increase of LPS dose (P<0.05). The wet/dry weight ratio of lung, the level of histone H4 in BALF and the relative expression of Tnfa and Il1b mRNA in AMs increased with the increase of LPS dose (all P<0.05). The mice in the 6 and 8 mg/kg LPS groups developed ARDS. The level of histone H4 in BALF and the relative expression of Tnfa and Il1b mRNA in AMs of mice in 6 and 8 mg/kg LPS groups were higher than those in the other three groups (all P<0.05). ii) The relative expression of Tnfa and Il1b mRNA increased (both P<0.05), and the relative expression of Cd206 and Arg1 mRNA decreased (both P<0.05) in AMs of histone H4 injury group and BALF injury group compared with the control group. Compared with BALF injury group, the relative mRNA expression of Tnfa and Il1b in AMs of anti-H4 intervention group decreased (both P<0.05), while the relative expression of Arg1 mRNA increased (P<0.05). Conclusion LPS can induce a dose-dependent increase in histone H4 levels in BALF in mice. Histone H4 drives the development of ARDS by activating AMs to M1 polarization. Antagonizing histone H4 to interfere with AM polarization to M1 could be a target for the treatment of ARDS.

Icariin Ameliorates Efferocytosis Dysfunction of Alveolar Macrophages Stimulated by Cigarette Smoke Extract via PPARγ Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of icariin in ameliorating efferocytosis dysfunction and inflammatory response of alveolar macrophages induced by cigarette smoke extract via the peroxisome proliferator-activated receptor gamma （PPARγ） signaling pathway. MethodThe untreated rat alveolar macrophages （NR8383） were taken as the blank group. The NR8383 cells treated with 10% cigarette smoke extract were divided into model， low-， medium-， and high-dose （10， 20， 40 μmol·L-1） icariin， PPARγ inhibitor， and PPARγ inhibitor + low-， medium-， and high-dose icariin groups. Alamar blue colorimetry was employed to examine the proliferation and toxicity of icariin on NR8383 cells. The efferocytosis rate of NR8383 cells was detected by flow cytometry. Enzyme-linked immunosorbent assay was employed to measure the levels of tumor necrosis factor-alpha （TNF-α）， transforming growth factor-β1 （TGF-β1）， and milk fat globule-epidermal growth factor 8 （MFG-E8）. Western blot and Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） were employed to determine the protein and mRNA levels， respectively， of PPARγ， CD36， and RAS-related C3 botulinum toxin substrate 1 （Rac1）. ResultThe efferocytosis dysfunction model of NR8383 was established with the cigarette smoke extract. Compared with the blank control group， the model group showed decreased efferocytosis rate （P<0.05）， elevated TNF-α level （P<0.05）， lowered TGF-β1 and MFG-E8 levels （P<0.01）， and down-regulated mRNA and protein levels of PPARγ， CD36， and Rac1 （P<0.05， P<0.01）. Compared with the model group， the treatment with icariin increased the efferocytosis rate （P<0.05， P<0.01）， lowered the TNF-α level （P<0.01）， elevated TGF-β1 and MFG-E8 levels （P<0.05）， and up-regulated the protein and mRNA levels of PPARγ， CD36， and Rac1 （P<0.05， P<0.01）. Compared with icariin alone， PPARγ inhibitor + icariin decreased the efferocytosis rate （P<0.05） and down-regulated the protein and mRNA levels of PPARγ （P<0.05， P<0.01）. In addition， PPARγ inhibitor + low-dose icariin down-regulated the protein level of CD36 （P<0.01） and PPARγ inhibitor + low-/medium-dose icariin up-regulated the protein level of Rac1 （P<0.05）. ConclusionIcariin ameliorates the cigarette smoke extract-induced efferocytosis dysfunction of alveolar macrophage by regulating the PPARγ signaling pathway and cytoskeletal structure rearrangement.

Effect of cold stimulation on phenotype of alveolar macrophages in mice / 中国生物制品学杂志

@#Objective To investigate the effect of cold stimulation on the phenotype of alveolar macrophages(MH-S cells) in mice. Methods MH-S cells were cultured at 37 ℃ for 24 h,and cold stimulated at 36,34 and 32 ℃ for 0,0. 5,1,3,6,9 and 12 h respectively. The mRNA transcription levels of interleukin-1β(IL-1β) and interleukin-10(IL-10) genes in MH-S cells were detected by qRT-PCR. MH-S cells were cultured at 37 ℃ for 24 h,and cold stimulated at 34 ℃ for 0. 5 h,which were detected for the mRNA transcription levels of tumor necrosis factor-α(TNF-α),inducible nitric oxide synthase(iNOS)and Arginase1(Arg1)genes by qRT-PCR(MH-S cells with 0 h cold stimulation as control),detected for the expression of iNOS and Arg1 by immunofluorescence assay(MH-S cells cultured at 37 ℃ for 0. 5 h as negative control)and detected for the expression levels of iNOS,TNF-α and nuclear factor-kappa B(NF-κB)by Western blot(MH-S cells cultured at 37 ℃ for 0. 5 h as negative control). Results The mRNA transcription levels of IL-1β and IL-10 genes in MH-S cells were the highest when the cells were cultured at 34 ℃ for 0. 5 h,therefore,the cold stimulation model of MH-S cells was established under this condition. Compared with the cells cultured for 0 h,the mRNA transcription levels of iNOS,TNF-α and Arg1genes in MH-S cells cultured at 34 ℃ for 0. 5 h increased significantly(t = 3. 733,12. 190 and 6. 793,respectively,each P < 0. 05). Compared with the negative control group,the fluorescence expression intensity of iNOS and Arg1 in MH-S cells in the stimulation group increased,especially iNOS,the expression levels of iNOS and TNF-α proteins increased with no significant difference(t = 0. 675 and 1. 514,respectively,each P > 0. 05),and the expression level of NF-κB increased significantly(t = 3. 092,P < 0. 05). Conclusion Cold stimulation at 34 ℃ for 0. 5 h can increase the expression of inflammatory factors such as IL-1β,IL-10,TNF-α,iNOS,Agr1 and NF-κB in MH-S cells,activate NF-κB signaling pathway in MH-S cells,induce the expression of inflammatory proteins and promote cell activation.

Chlamydia muridarum respiratory infection induces infiltration and polarization of alveolar macrophages and pulmonary interstitial macrophages / 中华微生物学和免疫学杂志

Objective:To investigate the effects of Chlamydia muridarum ( Cm) respiratory tract infection on the infiltration and polarization of alveolar macrophages (AMs) and pulmonary interstitial macrophages (IMs). Methods:A C57BL/6 mouse model of Cm respiratory tract infection was established through nasal inhalation. Flow cytometry was used to detect AMs (CD45 + F4/80 + CD11c + ) and IMs (CD45 + F4/80 + CD11c -) in lung tissues at 0, 3, 7 and 14 d after Cm respiratory tract infection. The proportions of M1 (CD80 + , CD86 + , MHCⅡ + , iNOS + ) and M2 (CD206 + , Arg1 + ) macrophages in AMs and IMs were also detected. Results:(1) Cm respiratory tract infection induced the infiltration of AMs and IMs. Compared with the uninfected group (0 d), the proportions and the numbers of AMs and IMs of were significantly increased 3 d after infection ( P<0.05, P<0.01). The numbers of AMs and IMs reached the peak 7 d after infection ( P<0.001). (2) Compared with the uninfected group, the proportions of CD80 + and CD86 + cells in AMs were significantly up-regulated 3 d after infection ( P<0.05, P<0.01); the proportion of MHCⅡ + cells in AMs increased after infection and reached the peak at 14 d ( P<0.05), while the proportion of CD206 + cells decreased after infection ( P<0.05). (3) Compared with the uninfected group, the proportions of CD80 + and CD86 + cells in IMs were increased 3 d after infection ( P<0.05, P<0.001) and the proportion of MHCⅡ + cells was significantly increased 14 d after infection ( P<0.01), while there was no significant change in the proportion of CD206 + cells. (4) In AMs, the proportion of iNOS + cells increased continuously after infection ( P<0.01), while the proportion of Arg1 + cells decreased continuously after infection, especially at 7 d and 14 d ( P<0.05). In IMs, the proportion of iNOS + cells reached the peak at 7 d ( P<0.001), but the proportion of Arg1 + cells showed no significant change after infection. Conclusions:Cm respiratory tract infection induced the infiltration of AMs and IMs, stimulated the polarization of AMs and IMs towards the M1 phenotype and weakened the polarization of AMs to M2 macrophages, but had no significant influence on the polarization of IMs towards the M2 phenotype.

Extracellular vesicle activities regulating macrophage- and tissue-mediated injury and repair responses

Macrophages are typically identified as classically activated (M1) macrophages and alternatively activated (M2) macrophages, which respectively exhibit pro- and anti-inflammatory phenotypes, and the balance between these two subtypes plays a critical role in the regulation of tissue inflammation, injury, and repair processes. Recent studies indicate that tissue cells and macrophages interact

Nanomedicine for acute respiratory distress syndrome: The latest application, targeting strategy, and rational design

Acute respiratory distress syndrome (ARDS) is characterized by the severe inflammation and destruction of the lung air-blood barrier, leading to irreversible and substantial respiratory function damage. Patients with coronavirus disease 2019 (COVID-19) have been encountered with a high risk of ARDS, underscoring the urgency for exploiting effective therapy. However, proper medications for ARDS are still lacking due to poor pharmacokinetics, non-specific side effects, inability to surmount pulmonary barrier, and inadequate management of heterogeneity. The increased lung permeability in the pathological environment of ARDS may contribute to nanoparticle-mediated passive targeting delivery. Nanomedicine has demonstrated unique advantages in solving the dilemma of ARDS drug therapy, which can address the shortcomings and limitations of traditional anti-inflammatory or antioxidant drug treatment. Through passive, active, or physicochemical targeting, nanocarriers can interact with lung epithelium/endothelium and inflammatory cells to reverse abnormal changes and restore homeostasis of the pulmonary environment, thereby showing good therapeutic activity and reduced toxicity. This article reviews the latest applications of nanomedicine in pre-clinical ARDS therapy, highlights the strategies for targeted treatment of lung inflammation, presents the innovative drug delivery systems, and provides inspiration for strengthening the therapeutic effect of nanomedicine-based treatment.

cGAS/STING signaling pathways induces the secretion of type Ⅰ interferon in porcine alveolar macrophages infected with porcine circovirus type 2 / 生物工程学报

In order to study the signal pathway secreting type Ⅰ interferon in porcine alveolar macrophages (PAMs) infected with porcine circovirus type 2 (PCV2), the protein and the mRNA expression levels of cGAS/STING pathways were analyzed by ELISA, Western blotting and quantitative reverse transcriptase PCR in PAMs infected with PCV2. In addition, the roles of cGAS, STING, TBK1 and NF-κB/P65 in the generation of type I interferon (IFN-I) from PAMs were analyzed by using the cGAS and STING specific siRNA, inhibitors BX795 and BAY 11-7082. The results showed that the expression levels of IFN-I increased significantly at 48 h after infection with PCV2 (P<0.05), the mRNA expression levels of cGAS increased significantly at 48 h and 72 h after infection (P<0.01), the mRNA expression levels of STING increased significantly at 72 h after infection (P<0.01), and the mRNA expression levels of TBK1 and IRF3 increased at 48 h after infection (P<0.01). The protein expression levels of STING, TBK1 and IRF3 in PAMs infected with PCV2 were increased, the content of NF-κB/p65 was decreased, and the nuclear entry of NF-κB/p65 and IRF3 was promoted. After knocking down cGAS or STING expression by siRNA, the expression level of IFN-I was significantly decreased after PCV2 infection for 48 h (P<0.01). BX795 and BAY 11-7082 inhibitors were used to inhibit the expression of IRF3 and NF-κB, the concentration of IFN-I in BX795-treated group was significantly reduced than that of the PCV2 group (P<0.01), while no significant difference was observed between the BAY 11-7028 group and the PCV2 group. The results showed that PAMs infected with PCV2 induced IFN-I secretion through the cGAS/STING/TBK1/IRF3 signaling pathway.

Implicações da dieta hiperlipídica e do exercício de natação sobre os parâmetros imunológicos em ratas

RESUMO Objetivou-se avaliar alterações imunes, entre obesidade e exercício (natação). Ratas Wistar foram alocadas, conforme regime dietético: Grupo Labina (GL) e Grupo Hiperlipídico (GH); e, aos 60 dias, segundo o exercício. Após protocolo de exercício, avaliaram-se parâmetros murinométricos, gordura visceral, série branca do sangue e cultura de macrófagos. Observamos aumento nos parâmetros murinométricos, na gordura visceral do GH sedentário e nos linfócitos, neutrófilos e basófilos do GH exercitado. A taxa de fagocitose e a produção de óxido nítrico estimulado com lipopolissacarídeos aumentaram nos ratos exercitados. A natação parece reverter o fenótipo de sobrepeso, promovido pela dieta hiperlipídica, atenuou os efeitos dessa no sistema imune e melhorou sua resposta.

ABSTRACT The aim was to evaluate immune changes between obesity and swimming. Wistar rats were allocated according to dietary regimen: Labina Group (LG) and Hyperlipid Group (HG); and at 60 days, according to the exercise. After exercise protocol, murinometric parameters, visceral fat, white blood series and macrophage culture were evaluated. We observed an increase in the murinometric parameters and visceral fat of the sedentary HG, and in the lymphocytes, neutrophils and basophils of the exercised HG. The rate of phagocytosis and the production of nitric oxide stimulated with lipopolysaccharides increased in the exercised rats. Swimming seems to reverse the overweight phenotype promoted by the hyperlipid diet and attenuated the effects it on the immune system, improving its response.

RESUMEN El objetivo de este artículo fue evaluar cambios inmunológicos entre obesidad y ejercicio (natación). Se distribuyó a ratas Wistar según el régimen dietético: grupo labina (GL) y grupo hiperlipídico (GH). Y a los 60 días, según el ejercicio. Después del protocolo de ejercicio, se evaluaron los parámetros murinométricos, grasa visceral, serie blanca de la sangre y cultivo de macrófagos. Se observó un aumento de los parámetros murinométricos y de la grasa visceral del GH sedentario, así como en los linfocitos, neutrófilos y basófilos del GH ejercitado. La tasa de fagocitosis y la producción de óxido nítrico estimulado con lipopolisacárido aumentaron en las ratas ejercitadas. Parece que la natación revierte el fenotipo de sobrepeso promovido por la dieta hiperlipídica y atenúa los efectos de esta en el sistema inmunitario, por lo que mejora su respuesta.

Effect of electroacupuncture on pulmonary function and M1 polarization of alveolar macrophages in rats with chronic obstructive pulmonary disease / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Zusanli" (ST36) and "Feishu" (BL13) on M1 polarization of alveolar macrophages (AM) in rats with chronic obstructive pulmonary disease(COPD), so as to explore its anti-inflammatory mechanism underlying improvement of COPD. METHODS: Forty SD rats were randomly divided into normal and normal＋EA, COPD model and COPD＋EA groups (n＝10 in each group). The COPD model was established by simple fumigation. EA (4 Hz/20 Hz, 1 to 2 mA) was applied to bilateral ST36 and BL13 for 30 min, once every other day for 2 weeks. The pulmonary function including the forced vital capacity (FVC), forced expiratory volume in 0.1 and 0.3 s (FEV0.1, FEV0.3, FEV0.1/FVC, and FEV0.3/FVC) was detected by using a small animal respiratory function detector. Histopathological changes of the lung were displayed by H．E. staining. The contents of tumor necrosis factor-α (TNF-α) and induced nitric oxide synthase (iNOS) in the broncho alveolar lavage fluid (BALF) were assayed by ELISA. The expression of M1 polarization markers (CD86，iNOS), myeloid differentiation factor 88(MyD88) and nuclear factor-κB p65(NF-κB p65) in AM were detected by Western blot and quantitative real time-PCR, separately. The distribution and expression of CD86 in the lung were detected by immunohistochemistry. RESULTS: Following modeling, the levels of FVC, FEV0.1, FEV0.3, ratios of FVE0.1/FVC and FEV0.3/FVC were significantly decreased (P<0.01), while the contents of TNF-α and iNOS in the BALF, expression of CD86, iNOS, MyD88 and NF-κB p65 mRNAs and proteins in the AM, and CD86 immunoactivity in the lung were significantly increased in the model group relevant to the normal group (P<0.01). After the intervention, the decrease of the lung function and increase of the above-mentioned genes and proteins were all reversed in the COPD＋EA group (P<0.05, P<0.01). CONCLUSION: EA at ST36 and BL13 can reduce pulmonary inflammation in COPD rats, which may be related to its function in inhibiting M1 polarization of AM via down-regulating MyD88/NF-κB p65 signaling pathway.

Effect of M1/M2 Alveolar Macrophage Subsets in COVID-19 and Regulatory Mechanism of Traditional Chinese Medicine / 中国实验方剂学杂志

The pathological anatomical results of coronavirus disease-2019 (COVID-19) patients showed that excessive inflammatory reaction in the lungs is one of the important causes for such complications as acute lung injury or acute respiratory distress syndrome. Therefore, regulation of immune response may be an effective measure for COVID-19. Alveolar macrophages have a high heterogeneity and plasticity. The dynamic changes of subsets balance and function of M1/M2 alveolar macrophages have a significant effect on pulmonary inflammatory response during the early and late stages of infection. This paper reviews the classification and function of macrophages and explores the mechanism of alveolar macrophage in the pathological process of COVID-19 at different stages and the pharmacodynamic mechanism of traditional Chinese medicine. Besides, it provides ideas for the treatment of COVID-19 with traditional Chinese medicine and other drugs' research and development based on the regulation of macrophage polarization.

Mechanism of curcumin in inhibiting silica-induced NLRP3 inflammasome activation in mouse alveolar macrophages / 中国职业医学

OBJECTIVE: To explore the molecular mechanism of curcumin in inhibiting the nucleotide-binding oligomerization domain like receptor family pyrin domain-containing(NLRP3) inflammatory bodies induced by silica(SiO_2) in mouse alveolar macrophages(AM). METHODS: AMs were isolated from the bronchoalveolar lavage fluid of specific pathogen free C57 BL/6 mice and divided into 6 groups. Among them, the AM of the control group received no stimulation; the AM in the SiO_2 stimulation group was stimulated with SiO_2 suspension at the final mass concentration of 50 mg/L; the AM in nuclear factor(NF-κB)inhibition group was pretreated with 5-(4-fluorophenyl)-2-urea-thiophene-3-formamide with a final concentration of 200 nmoL/L for 1 hour, the AM in the low-, medium-and high-dose curcumin groups were pretreated with curcumin with the final concentrations of 20, 40 and 50 μmol/L for 1 hour, respectively, and then stimulated with SiO_(2 )suspension with a final concentration of 50 mg/L. Samples were collected after 6 hours of incubation. The mRNA expression of NLRP3 inflammasome related genes such as NLRP3, Caspase-1 and interleukin(IL)-1β was detected by real-time fluorescence quantitative polymerase chain reaction. The secretion level of maturation IL-1β(mIL-1β) and IL-18 in AM was detected by enzyme-linked immunosorbent assay. The protein expression and secretion level of cleaved Caspase-1, precursor-IL-1β(pro-IL-1β) and mIL-1β were analyzed by Western blotting. RESULTS: The mRNA relative expression of NLRP3, Caspase-1 and IL-1β, and the secretion levels of mIL-1β and IL-18, and the protein relative expression of Caspase-1, pro-IL-1β and mIL-1β, as well as the secretion levels of cleaved Caspase-1 and mIL-1β increased in the SiO_2 stimulated group compared with the control group(P<0.05). Except for the relative expression and the secretion level of cleaved Caspase-1, the other 8 indexes in the NF-κB inhibition group were lower than that in the SiO_2 stimulation group(P<0.05). Except for the relative expression of cleaved Caspase-1 and mIL-1β proteins in the low-dose curcumin group, the relative expression of all the above 10 indexes was lower in the three curcumin treated groups than that in the SiO_2 stimulation group(P<0.05). In addition, all the above indexes decreased with the increase of curcumin intervention dose(P<0.05). The mRNA relative expression of NLRP3 and IL-1β, and the protein relative expression of pro-IL-1β increased in the medium-dose curcumin group(P<0.05), the secretion levels of mIL-1β and IL-18, as well as the protein relative expression and secretion levels of cleaved Caspase-1 and mIL-1β decreased(P<0.05), compared with the NF-κB inhibition group. CONCLUSION: Curcumin can inhibit SiO_2-induced AM NLRP3 inflammasome activation in a dose-response relationship. This process may be related to the inhibition of NF-κB signaling pathway by curcumin and the down-regulating NLRP3 inflammasome-related genes at the transcriptional level. The important mechanism may be that curcumin directly blocks the activation, assembly, and downstream shearing of NLRP3 in inflammasomes.

Advances in research on the role of alveolar macrophage burial function in chronic obstructive pulmonary disease / 中华危重病急救医学

As one of the top three causes of death in the world, chronic obstructive pulmonary disease (COPD) is a serious hazard to human health. Macrophages play an important role in COPD, and their efferocytosis function is essential for ending chronic inflammation of COPD. Efferocytosis damage of alveolar macrophages (AM) in patients with COPD causes the rising of bacterial infection and airway bacterial colonization risk in lungs, which is the main reason for the acute exacerbation and the rising of incidence rate and mortality rate in COPD. In recent years, the regulation of macrophage efferocytosis function in COPD has becoming a research hotspot. Progress on the role of macrophage efferocytosis function on COPD, and the breakthrough points of improving AM efferocytosis dysfunction by traditional Chinese medicine is reviewed, so as to provide new ideas for the prevention and treatment of COPD.

Research advances in interaction between il-4 and il-13, and m2 alveolar macrophages in pulmonary fibrosis / 中国药理学与毒理学杂志

Type-2 helper T cells (Th2) are a group of cells differentiated from CD4∗ T cells after antigen stimulation. lnterleukin-4(IL-4) and IL-13 secreted by Th2 cells act on macrophages and acti-vate them into M2 macrophages via "alternative activation". When lung tissue is continuously stimulated by the antigen, the alveolar and interstitial macrophages are activated by IL-4 and IL-13 secreted by Th2 cells to form M2 type alveolar macrophages, thereby participating in pulmonary fibrosis (PF). The process shows that M2 alveolar macrophages play an important role in PF. In this review, we investigated the role of cytokine IL-4 and IL-13 in PF, the anti-inflammatory and profibrotic effects of M2 alveolar macrophages, the role of IL-4 and IL-13 receptors in the treatment of PF and the dual role of M2 alveolar macrophages activated by IL-4 and IL-13 in PF. Hoping to spark novel ideas for the study of anti-PF drugs.

Regulation of angiotensin Ⅱ type 2 receptor in mechanically ventilated lung injury / 中华急诊医学杂志

Objective Through the study of angiotensin Ⅱ-type 2 receptor agonist(AT2R)after pretreatment of mechanical ventilation lung injury(VILI)in rats model,to clarify the role of angiotensin Ⅱ-type 2 receptor agonist(C21)in alleviating VILI inflammation and the damage of immune function and its possible mechanism.Methods In this experiment,the acute lung injury model was established by mechanical spring-volume ventilation in SD rats,and C21 pretreatment was performed to observe the pathological condition of lung tissue in rats with different ventilation duration,and to detect the inflammatory changes of BALF lavage fluid.Flow cytometry was used to detect the CD68+/INOS+labeled M 1 type Amφ and the CD68+/Arg-1+labeled M2 type Amφ in alveolar lavage fluid.Results The mechanical VILI rat model was successfully established.The pathological injury score of the mechanical ventilation 4 h model,the wet/dry weight of lung tissue,the number of cells and protein in BALF lavage fluid were increased significantly,the levels of TNF-α and IL-1 were increased significantly,the levels of IL-4 and IL-10 were decreased significantly,and the level of inflammatory reaction decreased with the increase of ventilation time.The M1/M2 ratio in the 4 h ventilation model group was the highest,which was significantly different from the control group(P＜0.05).Compared to the model group,the C21 pretreatment significantly reduced the levels of proinflammatory factors TNF-α and IL-1,and increased the levels of anti-inflammatory factors IL-4 and IL-10 in BALF(P＜O.O1).After the intervention of AT2R agonist at 4 h,6 h and 8 h,the M1/M2 ratio of the model was lower than that of the model without AT2R agonist at 4 h,6 h and 8 h.Conclusion Mechanical ventilation for 4 h in SD rats can establish a mechanical ventilation lung injury model.AT2R agonist C21 can promote the polarization of macrophages to m2-type,and C21 pretreatment may alleviate VILI inflammation and immune damage by altering the polarization of macrophages.

Regulation of angiotensin Ⅱ type 2 receptor in mechanically ventilated lung injury / 中华急诊医学杂志

Objective@#Through the study of angiotensinⅡ- type 2 receptor agonist (AT2R) after pretreatment of mechanical ventilation lung injury (VILI) in rats model, to clarify the role of angiotensin Ⅱ - type 2 receptor agonist (C21) in alleviating VILI inflammation and the damage of immune function and its possible mechanism.@*Methods@#In this experiment, the acute lung injury model was established by mechanical spring-volume ventilation in SD rats, and C21 pretreatment was performed to observe the pathological condition of lung tissue in rats with different ventilation duration, and to detect the inflammatory changes of BALF lavage fluid. Flow cytometry was used to detect the CD68+/iNOS+ labeled M1 type AMφ and the CD68+/Arg-1+ labeled M2 type AMφ in alveolar lavage fluid.@*Results@#The mechanical VILI rat model was successfully established. The pathological injury score of the mechanical ventilation 4 h model, the wet/dry weight of lung tissue, the number of cells and protein in BALF lavage fluid were increased significantly, the levels of TNF-α and IL - 1 were increased significantly, the levels of IL-4 and IL-10 were decreased significantly, and the level of inflammatory reaction decreased with the increase of ventilation time. The M1/M2 ratio in the 4 h ventilation model group was the highest, which was significantly different from the control group (P<0.05). Compared to the model group, the C21 pretreatment significantly reduced the levels of proinflammatory factors TNF-αand IL-1, and increased the levels of anti-inflammatory factors IL-4 and IL-10 in BALF (P<0.01). After the intervention of AT2R agonist at 4 h, 6 h and 8 h, the M1/M2 ratio of the model was lower than that of the model without AT2R agonist at 4 h, 6 h and 8 h.@*Conclusion@#Mechanical ventilation for 4 h in SD rats can establish a mechanical ventilation lung injury model. AT2R agonist C21 can promote the polarization of macrophages to m2-type, and C21 pretreatment may alleviate VILI inflammation and immune damage by altering the polarization of macrophages.

Relationships between phagocytosis, mucoid phenotype, and genetic characteristics of Klebsiella pneumoniae clinical isolates

Abstract INTRODUCTION The relationships between phagocytosis, and mucoid phenotype, plasmid profile and virulence, and resistance genetic characteristics of Klebsiella pneumoniae clinical isolates were evaluated. METHODS Thirty isolates were used to determine the mucoid aspect. Four were selected for analysis of phagocytosis by alveolar macrophages. RESULTS Thirty percent of the samples presented the mucoid phenotype. The phagocytosis rate ranged from 21.5% to 43.43%. Phagocytosis was not correlated with the plasmid profile, but was apparently correlated with mucoid phenotype and antibiotic susceptibility. CONCLUSIONS: Several virulence factors act in parallel in K. pneumoniae to impair host defense.

Signal molecule 3-oxo-C12-HSL of Pseudomonas aeruginosa promotes autophagy of mouse alveolar macrophages MH-S cells / 基础医学与临床

Objective To investigate the effect of 3-oxo-C12-HSL on autophagy in mouse alveolar macrophages MH-S cells. Methods MH-S cells were treated with culture supernatants of the mutant and wild type Pseudomonas aeruginosa(PA) strains of LasI gene(3-oxo-C12-HSL synthetic gene) and chemically synthesized 3-oxo-C12-HSL signaling molecules. GFP puncta was observed by laser confocal fluorescence microscopy and the ratio of LC3Ⅱ/LC3Ⅰ was detected by Western blot to detect the formation of autophagic.Autophagic flux was also detected by mo-nitoring the degradation of p62 and the change of chloroquine to LC3Ⅱ/LC3Ⅰratio. Results The supernatant of the culture medium of the wild type PA strain increased the GFP puncta of the MH-S cells(P<0.05) and the ra-tio of LC3Ⅱ/LC3Ⅰ(P<0.01),The mutant PA strain of LasI gene could not cause the above changes related to autophagy. The chemically synthesized 3-oxo-C12-HSL signal molecules could increase the number of autophagic bodies and the expression of LC3Ⅱ (P<0.01). Autophagic substrate p62 was degraded by 3-oxo-C12-HSL. Chloroquine, a lysosomal inhibitor, enhanced LC3Ⅱaccumulation caused by 3-oxo-C12-HSL (P<0.05,P<0.01).Conclusions 3-oxo-C12-HSL increases the level of autophagy in MH-S cells.

The inflammatory effect of exosomes derived from alveolar epithelial cells stimulated by lipopolysaccharide on the alveolar macrophages / 中华急诊医学杂志

Objective To explore the inflammatory effect of exosomes derived from alveolar epithelial cells stimulated by lipopolysaccharide (LPS) on the alveolar macrophages (NR8383). Methods The alveolar epithelial cells disposed with different treatments were co-cultured with alveolar macrophages by using a Transwell system separately. Alveolar epithelial cells (RLE-6TN) were randomly divided into 4 groups: normal group, LPS-stimulated group, exosome inhibitor group, and exosome inhibitor pretreatment + LPS stimulation group. NR8383 cultured alone was considered as a blank control. After the 12-h co-culture, the real-time PCR (qPCR) was performed to examine the mRNA relative expression of IL-6, TNF-α, and IL-1β in NR8383 cells. To further explore the role of exosomes derived from RLE-6TN on alveolar macrophages mediated inflammationary response, the experimental exosomes (exosomes derived from LPS-induced RLE-6TN) and control exosomes exosomes derived from normal RLE-6TN were extracted by gradient ultracentrifugation. Transmission electron microscopy and Western blotting analyses was performed to identify the exosomes, and qNano particle diameter analyzer was conducted to measure the particle diameter of exosomes. In vitro, NR8383 cells were divided into 3 groups which were cultured with exosomes derived from LPS-stimulated RLE-6TN at a concentration of 10 μg/mL (experimental group), exosomes derived from untreated RLE-6TN at the same concentration of 10 μg/mL (control group), and the PBS at the same volume with experimental group (PBS group), respectively for 12 h. After the treatment, the phagocytosis of NR8383 cells was observed by laser confocal microscope and the release of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α in supernatants of NR8383 was detected by enzyme-linked immunosorbent assay ELISA Results (1)In the co-culture experiment, the mRNA relative expression of pro-inflammatory cytokine in the LPS group was significantly increased compared with the blank control group (P<0.01), however comparing the exosome inhibitor pretreatment+LPS group with the LPS group, the expression of pro-inflammatory cytokine was decreased (P<0.01). (2) The extracted exosomes were observed as circular or elliptical vesicles with a diameter of 40-100 nm under the transmission electron microscopy. Western blotting analyses showed that the extracted exosomes express the protein marker, such as CD63 and CD9; After incubation with NR8383 cells for 5 h, laser scanning confocal microscope showed that the exosomes labeled with red fluorescent were uptaken by NR8383 cells. (3)After the exosomes derived from the LPS-disposed RLE-6TN and the normal RLE-6TN cells were incubated with NR8383 cells respectively. The ELISA test showed that treated the alveolar macrophages with LPS induced alveolar epithelial secreted exosomes led to a robustly increased release of pro-inflammatory cytokine (P<0.01), but there was no significant difference between the control group and PBS group (P>0.05). Conclusions Exosomes derived from LPS-disposed alveolar epithelial cells activate the alveolar macrophage-mediated inflammatory response.

The protective effect of broneol on LPS induced acute lung injury / 中国药理学通报

Aim To investigate the effect of broneol on acute lung injury(ALI) induced by lipopolysaccharide (LPS). Methods Male C57 mice were randomly di-vided into saline group, model group, broneol group and dexamethasone group, then the ALI mouse model was induced by instilling intratracheally with LPS. The levels of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),interleukin-6(IL-6) and keratinocyte-de-rived cytokine (KC) were measured at 6h, 12h and 24h after instillation of LPS, and the pathological changes of lung were observed. Mice alveolar macro-phages (MHS) and epithelial cells (MLE-12) were stimulated by LPS. After the stimulation of 1h, 3h, 6h,9h, 12h, 24h, the levels of TNF-α and IL-6 in MHS cells and the contents of KC and macrophage in-flammatory protein-2 (MIP-2) in MLE-12 cells were measured. Results Broneol could inhibit the secre-tion of TNF-α,KC and IL-1β;the early effect of bro-neol on IL-6 was not obvious,but the later effect after the treatment of 24 hours was obvious. After LPS instil-lation 6h and 12h,Broneol could significantly improve lung tissue pathological changes. Broneol had no effect on TNF-α secretion of MHS cells, but it obviously af-fected IL-6 secretion in the later stage. In addition, broneol significantly inhibited KC and MIP2 secretion in MLE-12 cells at the later stage of LPS stimulation. Conclusions Broneol can protect LPS-induced acute lung injury. The mechanism may be related to the inhi-bition of the release of inflammatory factors,the activa-tion of inflammatory cells and the aggregation of neutro-phils.

Role of Endoplasmic Reticulum Stress in Silica-induced Apoptosis in RAW264.7 Cells / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>We investigated the role of endoplasmic reticulum stress (ERS) in silica-induced apoptosis in alveolar macrophages in vitro.</p><p><b>METHODS</b>RAW264.7 cells were incubated with 200 μg/mL silica for different time periods. Cell viability was assayed by the MTT assay. Cell apoptosis was evaluated by DAPI staining, flow cytometry analysis, and Western blot analysis of caspase-3. Morphological changes in the endoplasmic reticulum were observed by transmission electron microscopy. The expression of ERS markers binding protein (BiP) and CCAAT-enhancer-binding protein homologous protein (CHOP) was examined by Western blotting and real-time PCR. As an inhibitor of ERS, 4-phenylbutyric acid (4-PBA) was used in the experiments.</p><p><b>RESULTS</b>Silica exposure induced nuclear condensation and caspase-3 expression in RAW264.7 cells. The number of apoptotic cells increased after silica exposure in a time-dependent manner. Silica treatment induced expansion of the endoplasmic reticulum. In addition, the expression of BiP and CHOP increased in silica-stimulated cells. Furthermore, 4-PBA treatment inhibited silica-induced endoplasmic reticulum expansion and the expression of BiP and CHOP. Moreover, 4-PBA treatment attenuated nuclear condensation, reduced apoptotic cells, and downregulated caspase-3 expression in silica-stimulated cells.</p><p><b>CONCLUSION</b>Silica-induced ERS is involved in the apoptosis of alveolar macrophages.</p>