BackgroundAlveolar macrophages (AMs) are specialized phagocytes in the airways that play a crucial role in maintaining bronchoalveolar homeostasis through phagocytosis, the clearance of apoptotic cells. However, the characteristics and molecular mechanisms of AMs-mediated phagocytosis during the pathogenesis of asthma remain poorly characterized.MethodsAn ovalbumin (OVA)-induced asthma model was established in mice through intraperitoneal sensitization followed by intranasal challenge. AMs were isolated from the bronchoalveolar lavage fluid of control and OVA-induced mice using adherence-based purification. The phagocytic capacity of AMs, as well as the expression levels of CD36 and ADAM17, were quantified by flow cytometry.ResultsA significant reduction in both phagocytic efficiency and CD36 expression was found in the AMs of OVA-induced mice compared to control mice. Blockade of CD36 resulted in a marked decline in the phagocytic efficiency of normal AMs. Expression of ADAM17 was found to be notably elevated on the surface of AMs from OVA-induced mice compared to controls. Knockdown of ADAM17 led to a substantial increase in CD36 expression and a corresponding increase in phagocytic efficiency. Stimulation with tumor necrosis factor-α (TNF-α) resulted in a significant upregulation in ADAM17 and marked downregulation in CD36 expression levels, as well as impaired the phagocytic efficiency of AMs. Importantly, ADAM17 knockdown attenuated the TNF-α-mediated downregulation of CD36 expression and the associated impairment of phagocytic capacity in AMs.ConclusionAMs from OVA-induced mice displayed significantly impaired phagocytic capacity. Airway TNF-α upregulated ADAM17, which in turn downregulated CD36 expression on AMs, ultimately suppressing their phagocytic function.

27-Hydroxycholesterol (27-HC) is an oxidative metabolite of cholesterol and an oxysterol catalysed by the mitochondrial cytochrome P450 enzyme, sterol 27-hydroxylase (CYP27A1). In addition to inducing the release of eosinophil chemotactic factors such as RANTES and Eotaxin, 27-HC enhances the differentiation of lung fibroblasts into myofibroblasts and promotes the production of extracellular matrix proteins. Therefore, it is possible that 27-HC may play a significant role in the pathogenesis of asthma. In this study, we observed elevated expression of CYP27A1 and increased production of 27-HC in the lung tissues of asthmatic mice, with alveolar macrophages (AMs) identified as the primary source of 27-HC. 27-HC induced an increase in total cell count and eosinophil number in the bronchoalveolar lavage fluid of asthmatic mice, exacerbated inflammatory cell infiltration into lung tissues, and heightened airway hyper-responsiveness, thereby aggravating asthma. The alarmin, IL-33, within airways induced 27-HC production by AMs via the NF-κB signalling pathway. Furthermore, 27-HC was shown to inhibit the phagocytosis of apoptotic cells (efferocytosis) by airway epithelial cells (AECs) through AMPK activation. Thus, in asthmatic mice, 27-HC, predominantly derived from AMs, influences the efferocytotic function of AECs, demonstrating that cross-talk between macrophages and epithelial cells regulates asthma pathogenesis. This study provides valuable insight into the molecular mechanisms underlying asthma and offers theoretical and experimental data for identifying novel therapeutic targets for clinical asthma management.

Objective:: Ulcerative colitis (UC) is a chronic non-specific inflammatory disease of the rectum and colon with unknown etiology. A growing number of evidence suggest that the pathogenesis of UC is related to excessive apoptosis and production of inflammatory cytokines. However, the functions and molecular mechanisms associated with UC remain unclear. Materials and Methods: The in vivo and in vitro models of UC were established in this study. MiRNA or gene expression was measured by qRT-PCR assay. ELISA, CCK-8, TUNEL, and flow cytometry assays were applied for analyzing cellular functions. The interactions between miR-146a and TAB1 were verified by luciferase reporter and miRNA pull-down assays. Results:: MiR-146a was obviously increased in UC patients, DSS-induced colitis mice, and TNF-ɑ-induced YAMC cells, when compared to the corresponding controls. MiR- 146a knockdown inhibited the inflammatory response and apoptosis in DSS-induced colitis mice and TNF-ɑ-induced YAMC cells. Mechanistically, we found that TAB1 was the target of miR-146a and miR-146a knockdown suppressed the activation of NF-κB pathway in UC. More importantly, TAB1 could overturn the inhibitory effect of antagomiR-146a on cell apoptosis and inflammation in UC. Conclusion:: MiR-146a knockdown inhibited cell apoptosis and inflammation via targeting TAB1 and suppressing NF-κB pathway, suggesting that miR-146a may be a new therapeutic target for UC treatment

Asthma is a common condition involving chronic airway inflammation that primarily affects women and boys. Estrogen levels correlate with the observed differences in the prevalence of asthma between the sexes, but the exact mechanism is unclear. This study established a castration mice (OVX) model through bilateral ovariectomy surgery, and subcutaneously injected estradiol (E2) into OVX asthmatic mice to analyze the effect of E2 on the onset of asthma. Then, airway inflammation was evaluated in the mice using airway resistance measurements, lung tissue hematoxylin and eosin staining, and eosinophil counts. Furthermore, the proportion of CD206-positive cells and the expression of M2 polarization markers, such as Arg1 and YM1, were detected in alveolar macrophages (AMs). The effects of different concentrations of E2 on M2 polarization of AMs were examined in vitro, and the types of estrogen receptors (ERs) involved were investigated. Transcriptome analysis combined with volcano plots and heatmaps were used to compare the differentially expressed genes to investigate the mechanism by which E2 affects M2 polarization of AMs. The results showed that female asthmatic mice had more severe airway inflammation and higher airway responsiveness than male asthmatic mice. E2 increased airway inflammation and airway resistance in asthmatic mice. E2 not only promoted M2 polarization of AMs in asthmatic mice in vivo, but also increased the expression of M2 markers, such as Arg1 and YM1, by AMs in vitro. The use of ERα antagonist AZD9496 reduced the effect of E2 on the promotion of M2 polarization in AMs. Analysis of transcriptome differences indicated that E2 upregulated expression of M2 breast cancer metastasis suppressor gene 1 (Brms1) in AMs. Notably, antagonism of ERα inhibited this upregulation of Brms1 gene expression. Interference with Brms1 mRNA production reduced the gene expression of Arg1 and YM1 in AMs undergoing M2 polarization after E2 stimulation. In summary, E2 exacerbates airway inflammation in asthmatic mice and binds to ERα, upregulating Brms1 expression and mediating M2 polarization of AMs.

Surfactant protein A (SP-A), a natural immune molecule, plays an important role in lung health. SP-A recognizes and binds microbial surface glycogroups through the C-type carbohydrate recognition domain, and then binds corresponding cell surface receptors (such as C1qRp, CRT-CD91 complex, CD14, SP-R210, Toll-like receptor, SIRP-α, CR3, etc.) through collagen-like region, and subsequently mediates biological effects. SP-A regulates lung innate immunity by promoting surfactant absorption by alveolar type II epithelial cells and phagocytosis of pathogenic microorganisms by alveolar macrophages. SP-A also regulates lung adaptive immunity by inhibiting DC maturation, and T cell proliferation and differentiation. This article reviews latest relationships between SP-A and adaptive and intrinsic immunity.

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects the joints. The pathogenesis of RA is complex, involving membrane lipid antioxidant systems, oxidative stress, and lipid peroxidation. In this study, it was found that cysteine dioxygenase 1 (CDO1) is significantly upregulated in RA fibroblast-like synoviocytes (RA-FLS) and that exosomes derived from these RA-FLS deliver CDO1 to promote M1 polarization of macrophages, thus facilitating RA progression. In the immune microenvironment, CD8+T cells play a role in immune regulation by producing cytokines such as interferon gamma (IFNγ) in various diseases. The results of this study suggested that in RA-FLS, CD8+T cells deliver IFNγ, which not only inhibits the viability of RA-FLS but also affects glutathione (GSH) through CDO1, regulating the GPX4 antioxidant signaling pathway to promote ferroptosis and autophagy in cells. It was also discovered that IFNγ enhances the expression of TRI69, ubiquitinates and degrades FSP1, thereby forming a cooperative regulation process of GPX4 and FSP1 in ferroptosis. These findings provide a new direction for the treatment of RA.

Objective To investigate the effect of interleukin-6 (IL-6) on the phagocytosis of MH-S alveolar macrophages and its related mechanisms. Methods A mouse acute lung injury (ALI) model was constructed by instilling lipopolysaccharide (LPS) into the airway. ELISA was used to detect the content of IL-6 in bronchoalveolar lavage fluid (BALF). In vitro cultured MH-S cells, in the presence or absence of signal transducer and activator 3 of transcription(STAT3) inhibitor Stattic (5 μmol/L), IL-6 (10 ng/mL~500 ng/mL) was added to stimulate for 6 hours, and then incubated with fluorescent microspheres for 2 hours. The phagocytosis of MH-S cells was detected by flow cytometry. Western blot analysis was used to detect the expression levels of phosphorylated Janus kinase 2 (p-JAK2), phosphorylated STAT3 (p-STAT3), actin-related protein 2 (Arp2) and filamentous actin (F-actin). Results The content of IL-6 in BALF was significantly increased after the mice were injected with LPS through the airway. With the increase of IL-6 stimulation concentration, the phagocytic function of MH-S cells was enhanced, and the expression levels of Arp2 and F-actin proteins in MH-S cells were increased. The expression levels of p-JAK2 and p-STAT3 proteins increased in MH-S cells stimulated with IL-6(100 ng/mL). After blocking STAT3 signaling, the effect of IL-6 in promoting phagocytosis of MH-S cells disappeared completely, and the increased expression of Arp2 and F-actin proteins in MH-S cells induced by IL-6 was also inhibited. Conclusion IL-6 promotes the expression of Arp2 and F-actin proteins by activating the JAK2/STAT3 signaling pathway, thereby enhancing the phagocytic function of MH-S cells.

Cluster of differentiation 47 (CD47) is a transmembrane protein that is widely and moderately expressed on the surface of various cells and can have an essential role in mediating cell proliferation, migration, phagocytosis, apoptosis, immune homeostasis and other related responses by binding to its ligands, integrins, thrombospondin-1 and signal regulatory protein alpha. The poor prognosis of cancer patients is closely associated with high expression of CD47 in glioblastoma, ovarian cancer, breast cancer, bladder cancer, colon cancer and hepatocellular carcinoma. Upregulation of CD47 expression facilitates the growth of numerous types of tumor cells, while downregulation of its expression promotes phagocytosis of tumor cells by macrophages, thereby limiting tumor growth. In addition, blocking CD47 activates the cyclic GMP-AMP (cGAMP) synthase/cGAMP/interferon gene stimulating factor signaling pathway and initiates an adaptive immune response that kills tumor cells. The present review describes the structure, function and interactions of CD47 with its ligands, as well as its regulation of phagocytosis and tumor cell fate. It summarizes the therapeutics, mechanisms of action, research advances and challenges of targeting CD47. In addition, this paper provides an overview of the latest therapeutic options for targeting CD47, such as chimeric antigen receptor (CAR) T-cells, CAR macrophages and nanotechnology-based delivery systems, which are essential for future clinical research on targeting CD47.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor originally identified as a stimulus that induces the differentiation of bone marrow progenitor cells into granulocytes and macrophages. GM-CSF is now considered to be a multi-origin and pleiotropic cytokine. GM-CSF receptor signals activate JAK2 and induce nuclear signals through the JAK-STAT, MAPK, PI3K, and other pathways. In addition to promoting the metabolism of pulmonary surfactant and the maturation and differentiation of alveolar macrophages, GM-CSF plays a key role in interstitial lung disease, allergic lung disease, alcoholic lung disease, and pulmonary bacterial, fungal, and viral infections. This article reviews the latest knowledge on the relationship between GM-CSF and lung balance and lung disease, and indicates that there is much more to GM-CSF than its name suggests.

目的 探讨新生儿脐血中性粒细胞(PMN)吞噬功能的变化及其影响因素.方法 收集2021年6—8月来自本院的健康成人血和脐血标本各13例,分离新鲜PMN,流式细胞仪检测PMN吞噬大肠杆菌的情况,ELISA法检测成人外周血和新生儿脐血血清中前列腺素E2(PGE2)的含量.应用不同浓度的PGE2(0-500 ng/ml)刺激PMN株HL-60细胞及PGE2(100 ng/ml)刺激新鲜分离的成人PMN 48小时后,流式细胞术观察HL-60细胞和PMN吞噬大肠杆菌的情况.结果 与成人PMN相比,新生儿PMN吞噬大肠杆菌百分率明显降低(P<0.01),但脐血PGE2的浓度较成人外周血明显升高(P<0.01);PGE2(100-500 ng/ml)刺激组HL-60细胞吞噬细菌百分率明显低于0 ng/ml组(P<0.01);成人PMN受PGE2(100 ng/ml)刺激后吞噬百分率明显降低(P<0.05).结论 新生儿脐血PMN吞噬功能降低,这可能是由于PGE2对PMN的抑制作用引起.

目的 探讨热休克蛋白70(heat shock protein 70,HSP70)对急性肺损伤(acute lung injury,ALI)小鼠发病的影响及其相关机制.方法 构建ALI模型小鼠,免疫印迹法检测肺组织中HSP70的表达情况,酶联免疫法检测支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)中HSP70的分泌情况.ALI小鼠经鼻滴HSP70抗体(anti-HSP70)后,抽取BALF,检测其中肿瘤坏死因子α(tumor necrosis factorα,TNF-α)、白细胞介素6(interleukin 6,IL-6)、白细胞介素1β(interleukin 1β,IL-1β)和蛋白的含量,并计数中性粒细胞的数目;获取肺组织进行苏木精-伊红染色并计算肺湿/干重比.以LPS刺激小鼠肺泡上皮细胞株MLE-12细胞,酶联免疫法检测培养上清液中TNF-α和IL-1β的含量.不同浓度的HSP70(10～500 ng/mL)刺激小鼠肺泡上皮细胞(alveolar epithelial cells,AECs)后,流式细胞术检测AEC吞噬凋亡细胞的情况.结果 与正常对照组小鼠相比,ALI小鼠肺组织中HSP70的表达及BALF中HSP70的分泌均增加(均P<0.05).与ALI组小鼠相比,经anti-HSP70鼻滴治疗后的ALI小鼠,其BALF中TNF-α、IL-6、IL-1β和蛋白的含量均降低(均P<0.05),中性粒细胞数目减少(P<0.05);其肺组织中炎性细胞浸润减少,肺湿/干重比降低(P<0.05).与LPS刺激组相比,anti-HSP70+LPS组MLE-12细胞培养上清液中TNF-α和IL-1β含量均减少(均P<0.05).与未刺激组相比,10～500 ng/mL HSP70刺激组MLE-12细胞吞噬凋亡细胞百分率明显降低,其中以200 ng/mL HSP70刺激组降低最为明显(P<0.01);与未刺激组相比,200 ng/mL HSP70刺激的小鼠原代肺泡上皮细胞吞噬率降低(P<0.01).结论 HSP70促进ALI小鼠肺部炎症反应,这一效应可能与HSP70降低肺泡上皮细胞吞噬凋亡细胞的功能相关.

Objective To investigate the effect of insulin-like growth factor 1 (IGF-1) on the migration of alveolar epithelial cells (AECs) and its related mechanisms. Methods The MLE-12 cells (mouse AEC line) were stimulated by IGF-1 and sphingosine 1 phosphate (S1P) in the presence or absence of the PI3K inhibitor Wortmannin. Then, the cell migration was detected by the scratch test and the expression of p-Akt was detected by Western blot. With AECs stimulated by IGF-1, the secretion and expression of S1P were tested by ELISA and Western blot respectively. In the blocking experiment, the effect of IGF-1 on cell migration or p-Akt expression was detected by scratch test or Western blot after the interference of AEC S1P receptor 1 (S1PR1) or the action of S1PR1 blocking antibody. Results After 12 hours of IGF-1 stimulation, the expression of p-Akt in AECs increased and the migration of AECs accelerated. When blocking PI3K signal, the effect of IGF-1 on promoting AEC migration was partially eliminated. IGF-1 induced AECs to produce S1P, which accelerated AEC migration through S1PR1. The expression of p-Akt in AECs increased after S1P stimulation. When blocking the PI3K pathway, the ability of S1P to accelerate the migration of AECs was reduced. When S1PR1 in AECs was blocked or interfered, the effect of IGF-1 on accelerating AEC migration and promoting AEC p-Akt expression was partially reduced. Conclusion IGF-1 activates the PI3K pathway through S1P-S1PR1 signal to promote the migration of AECs.

目的 探讨nanos1基因在日本血吸虫的定位以及不同发育时期的表达情况.方法 在NCBI上搜索日本血吸虫nanos1基因,PCR扩增、测序并将其全长序列经BLAST软件分析,利用DNAMAN6.0和ClustalX2.0.9进行多重序列比对,利用MAGA 5.05构建进化树进行系统进化分析.体外转录地高辛(DIG)标记的RNA探针,并将其用于日本血吸虫感染后第18、24和42天3个发育时期的雌雄虫整体原位杂交,以确定nanos1基因在日本血吸虫的定位.结果 PCR扩增获得日本血吸虫nanos1基因,生物信息学分析结果表明其编码的蛋白与曼氏血吸虫nanos2蛋白同源性最高.体外转录成功的RNA探针用于日本血吸虫整体原位杂交,在感染后第24、42天雌虫的卵巢和卵黄腺以及18天雌虫的卵巢检测到阳性杂交信号,而各个发育阶段的雄虫均未观察到明显阳性杂交信号.结论 日本血吸虫nanos1基因高表达于感染后第18天雌虫的卵巢以及第24、42天雌虫的卵巢和卵黄腺.该研究初步揭示了日本血吸虫nanos1基因的表达模式,为研究nanos1基因的功能提供了重要线索.

Nanos is a necessary factor in the differentiation and migration of primordial germ cells. It is closely associated with the development of genitalia in a wide range of species. We questioned whether Nanos was involved in the reproductive organ development of Schistosoma japonicum. Firstly, by in situ hybridization, S. japonicum Nanos1 (SjNanos1) gene was expressed mainly in reproductive organs of S. japonicum. Then, the paired schistosome of 28 days post-infection (dpi) was transfected with SjNanos1 small interfering RNA three times and cultured in vitro for 10 days. SjNanos1 expression suppression in the mRNA and protein levels were confirmed compared to that of the controls. The morphological changes in reproductive organs and egg production were observed after SjNanos1 gene knockdown. The results observed by confocal laser scanning microscopy showed significant changes in the morphology of reproductive organs of parasites, especially the female ovaries, vitellarium, and the male testes, after RNAi. In addition, SjNanos1 silencing also induced the reduction of eggs, and affected the changes of reproduction-related genes, like Pumilio, CNOT6L, and Fs800. Therefore, our findings demonstrate that the SjNanos1 gene is essential in the development of reproductive organs and the egg production of S. japonicum.

Vasa, an enzyme belonging to the helicase family, contributes to the regulation of reproductive system development in many species. Thus, we hypothesized that the Vasa3 gene may function in the reproductive system of the parasite Schistosoma japonicum (S. japonicum), which is a major causative agent of schistosomiasis. It is a severe disease globally affecting humans and animals. To test this hypothesis, we firstly conducted whole mount in situ hybridization analyses and found that the S. japonicum Vasa3 (SjVasa3) gene was expressed mainly in the reproductive organs. We then explored the reproductive functions of Vasa3 in S. japonicum using RNA interference (RNAi) techniques. Coupled schistosomes collected from mice 28days post infection (dpi) were transfected three times with SjVasa3-specific small interfering RNA (siRNA) and cultured in vitro for up to 10days. As measured by quantitative PCR (qPCR) and Western blot analysis, levels of SjVasa3 mRNA and protein in Vasa siRNA treated worms were significantly reduced compared with untreated and scrambled siRNA treated worms. Confocal laser scanning microscopy (CLSM) images showed markedly siRNA induced changes in the morphology of the reproductive organs, especially in the female ovary, vitellarium and the male testes. SjVasa3 gene silencing also significantly reduced egg production. These data demonstrate that SjVasa3 is essential in reproductive organ development and egg production in S. japonicum, and could be a potential target for developing novel compounds to treat schistosomiasis.

The Vasa gene is a vital germline marker to study the origin and development of germ cells and gonads in many organisms. Until now, little information was available about the characteristics of the Vasa gene in Schistosoma japonicum (S. japonicum). In this study, we cloned the open reading frame (ORF) of the S. japonicum Vasa-like gene (Sj-Vasa). The expression pattern and tissue localization of Sj-Vasa were also analyzed. Our results showed that Sj-Vasa shared the general feature of DEAD-box family member proteins. Sj-Vasa was transcribed and expressed throughout the S. japonicum life cycle with transcription exhibiting high levels at day 24 in both male and female worms, and the expression level in the female was always higher than that in the male. Sj-Vasa protein was localized in a variety of tissues of adult schistosomes, including the gonads (ovary, vitellarium, and testes), the subtegument, and some cells of the parenchyma. To our knowledge, this is the first report of preliminary characterization and expression of the Vasa-like gene that may play an important role in the development of the worm, especially in reproductive organs of S. japonicum.

Objective To explore the role of mouse interleukin-6 receptor fusion protein (mIL-6RFP)for the pro-tection of liver cells in the model of BALB /c mice infected with Schistosoma japonicum.Methods Nickel ion col-umn was used to obtain purified recombinant mIL-6RFP protein.In vitro,HepG2 cells were used to verify the bio-logical activity of mIL-6RFP.BALB /c mice were administrated by tail vein injection with 100 μg of mIL-6RFP or equal volume solvent,at 24,26,28,30,32,34,36,38,and 40 days after infection.Mice were sacrificed 48 h after the last injection.The granuloma size was measured in the mouse liver by HE staining.Interleukin-1β(IL-1β),interleukin-13 (IL-13 ),tumor necrosis factor-α (TNF-α) and chemokine (C-X-C motif) ligand 1 (CXCL1)mRNA levels in mouse liver tissue were detected by RT-PCR.Alanine aminotransferase (ALT)and as-partate transaminase (AST)were measured by the continuous monitoring method.Results HepG2 cells experi-ments showed that mIL-6RFP could reduce the effect of IL-6 on HepG2 cells,fibrinogen (FGG)and haptoglobin (HP)was significantly reduced (P <0.05).In the BALB /c mice infected with Schistosoma japonicum,when IL-6 was blocked the levels of ALT and AST were decreased significantly (P <0.05)compared with that of the solvent group,while there was no significant difference on granuloma formation.Conclusion In the BALB /c mice infec-ted with Schistosoma japonicum,mIL-6RFP can significantly improve the liver function but no obvious effect on granuloma formation.