scholarly journals Lipopolysaccharide-induced premature cervical ripening and inflammation in pregnant mice can be alleviated by nicotine

Author(s):  
Xinjia Han ◽  
Wen Ding ◽  
Baohua Lin ◽  
Juanhua Chen ◽  
Tiansong Zhang ◽  
...  

Abstract Background Clinical treatment of preterm birth (PTB) is usually dependent on inhibiting uterine contractions. Such therapy is only effective in the short-term and cannot fundamentally low the incidence of PTB. Premature cervical maturation is another important cause of PTB; it is associated with invasion of macrophages, which produce proinflammatory cytokines. We previously found that activation of the alpha-7 nicotinic acetylcholine receptor (α7nAChR) by nicotine alleviates the systemic inflammatory response in murine models of lipopolysaccharide (LPS)-induced PTB, but the underlying mechanisms remain unclear. Methods Cervical tissues were collected from women in preterm and term labor. An animal model of PTB was established by administering 25 µg/kg lipopolysaccharide (LPS) to normal pregnant C57BL/6 mice on gestational day 16 (GD16). PTB animals received 1 mg/kg of α7nAChR agonist nicotine or nicotine combined with 1 µg/kg α7nAChR antagonist α-bungarotoxin (α-BGT) from GD14 to GD17. The gestational age, the rates of preterm birth and the survival rate of pups were recorded. Immunofluorescence staining were utilized for the quantification of α7nAChR expression on cervical macrophages and changes in macrophage polarization, RT-PCR was used to determine the mRNA levels of M1 and M2 macrophage biomarkers. Elisa assay was used to detect changes in fetal inflammation. Immunofluorescence staining and western blotting were used to investigate the signaling pathways underlying nicotine’s promoting LPS-induced conversion of M1 macrophage to M2 in the cervix of PTB animals. Results α7nAChR expression on cervical macrophages and cervical collagen content was decreased in PTB patients and murine models of LPS-induced PTB. The number of M1 cervical macrophages, other pro-inflammatory mediators in the cervix and fetal inflammation was unregulated in pregnant mice following LPS administration. Nicotine treatment reduced the rate of PTB, decreased fetal inflammation, improved maternal and neonatal outcome; nicotine also increased polarization of cervical macrophages toward the anti-inflammatory M2 phenotype possibly by suppressing activation of the MAP kinases JNK and ERK1/2 and nuclear translocation of NF-κB and rescuing the inhibited JAK2/STAT3 and PI3K/AKT pathways. The effects of nicotine were reversed by the selective α7nAChR antagonist α-bungarotoxin (α-BGT). Conclusions Our findings indicate that nicotine prevents LPS-induced cervical ripening and inflammatory response by inducing M2 macrophage polarization, and nicotine may serve as potential anti-premature cervical maturation agents for treatment of PTB.

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Shan Zhu ◽  
Yuan Wang ◽  
Hongtao Liu ◽  
Wen Wei ◽  
Yi Tu ◽  
...  

Background. Numerous studies have demonstrated that the inflammatory response is involved in the progression of lipopolysaccharide- (LPS-) induced myocardial cell apoptosis. Accumulating evidence has shown that thyroxine participates in diseases by downregulating the inflammatory response. This study aimed at investigating whether thyroxine alleviates LPS-induced myocardial cell apoptosis. Methods. Bone marrow-derived macrophages (Mø) were treated with LPS and thyroxine, and Mø differentiation and Mø-related cytokine expression were measured. The effect of Mø differentiation on mouse cardiomyocyte (MCM) apoptosis was also detected in vitro. In addition, C57BL/6 mice underwent thyroidectomy and were treated with LPS 35 days later; subsequently, Mø differentiation and myocardial cell apoptosis in hearts were analyzed. To determine whether the nuclear factor-kappa B (NF-κB) p65 pathway mediates the effect of thyroxine on Mø differentiation and myocardial cell apoptosis, the specific NF-κB p65 pathway inhibitor JSH-23 was administered to mice that underwent a thyroidectomy. Results. Levothyroxine treatment significantly reduced the activation of the NF-κB p65 pathway, decreased M1 macrophage (Mø1) differentiation and Mø1-related cytokine mRNA levels in LPS-treated Mø, and increased M2 macrophage (Mø2) differentiation and Mø2-related cytokine mRNA expression. The protective effects of levothyroxine on MCM apoptosis mediated by LPS-treated Mø were alleviated by JSH-23. In mice, thyroidectomy aggravated LPS-induced cardiac injury and cardiac dysfunction, further promoted NF-κB p65 activation, and increased cardiac Mø1 expression and myocardial cell apoptosis but decreased cardiac Mø2 expression. JSH-23 treatment significantly ameliorated the thyroidectomy-induced increases in myocardial cell apoptosis and Mø differentiation. Conclusions. Thyroxine alleviated the Mø1/Mø2 imbalance, reduced the inflammatory response, decreased myocardial cell apoptosis, and protected against cardiac injury and cardiac dysfunction in LPS-treated mice. Thyroxine may be a novel therapeutic strategy to prevent and treat LPS-induced cardiac injury.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 646-646
Author(s):  
Alyssa Cull ◽  
Brooke Snetsinger ◽  
Michael J. Rauh

Abstract Introduction: The epigenetic regulator, TET2, catalyzes the conversion of methylcytosine to 5-hydroxymethylcytosine. Inactivating TET2 mutations are common in myeloid cancers such as chronic myelomonocytic leukemia (CMML). Although TET2 has been characterized in hematopoietic stem and progenitor cells, little is known about its role in disease-relevant monocytes/macrophages (MΦ). Previously, we found increased expression of M2 MΦ-associated arginase 1 (Arg1) in TET2 -mutant CMML and Tet2 -deficient MΦ. Therefore, our goals were to (1) characterize Tet family expression during normal murine MΦ differentiation and polarization, (2) determine the effect of Tet2 -deficiency on broader M1-M2 MΦ spectrum gene signatures. Methods: Hematopoietic-specific Tet2+/- and Tet2-/- knockout mice were generated by breeding floxed Tet2(f/f) with Vav-Cre mice (JAX), in accordance with Queen's University's Animal Care protocols. MΦs obtained by peritoneal lavage (PMΦ) and bone marrow differentiation (BMMΦ) from 9-13 week old Tet2-/- and 20-40 week old Tet2+/- mice were treated with an M1 stimulus (100ng/mL LPS) or an M2 stimulus (10ng/mL Il-4). Comparative gene expression analysis was conducted using a 591 candidate gene Mouse Immunology Gene Expression CodeSet (NanoString). Blood plasma samples collected from Tet2f/f and Tet2-/- mice were sent for cytokine/chemokine array analysis (Eve Technologies). Results: A survey of Tet mRNA expression in wild-type C57BL/6 mouse whole BM showed that Tet1 was most abundantly expressed, with Tet2 and Tet3 having relative abundances of 0.56±0.05 and 0.09±0.01 respectively. In contrast, Tet2 expression peaked, while Tet1 expression diminished during BMMΦ differentiation. Suggesting a functional role, loss of murine Tet2 is associated with skewed myelomonocytic differentiation (i.e. CMML phenotype). In terminally-differentiated MΦ, Tet2 was the most abundantly expressed Tet gene, suggesting MΦ-specific functions. Consistent with this, following a 3-hour LPS stimulation, Tet2 mRNA levels increased 2- to 4-fold, whereas Il-4 failed to induce a similar increase in expression. Overall, our results suggested that Tet2 plays a role in M1 but not M2 macrophage polarization. Based on these findings, we hypothesized that loss of Tet2 would lead to M1 program dysregulation. PMΦs were obtained from Tet2f/f and Tet2-/- mice (n=2/ genotype) and RNA was harvested from untreated and LPS- or Il-4-treated cells. Pools of these RNA samples were then screened using Nanostring. Overall, M1-associated markers such as Stat1, Socs1, Nfkbiz, Il-6, Il-27, Il-12, Il-1 and Ccl2 were markedly increased by 2- to 50-fold in resting Tet2-/- PMΦs compared to matched Tet2f/f samples. These same M1 genes demonstrated a reduced ability to be induced by LPS treatment. We also found that while the expression of most M2 genes was similar in controls versus knockouts, Il-1rn and Arg1 were overexpressed, and Marco was decreased. This suggested that Tet2 -deficient MΦs possess a complex phenotype with a potential homeostatic response to M1 gene dysregulation. We have previously seen variable upregulation of Arg1 in mouse BMMΦs and PMΦs. Approximately 60% of Tet2-deficient mice (+/- and -/-) (n=20) tested for MΦ Arg1 mRNA expression demonstrated 2- to 90-fold increases in Arg1 compared to pooled Tet2f/f controls (n=5). We were interested in investigating the underlying mechanisms contributing to this dramatic increase in expression. Using Nanostring on pooled Tet2-deficient PMΦs with low (n=7) or high (n=8) Arg1 mRNA expression, we were able to identify genes whose expression significantly correlated with Arg1 overexpression: Cxcl3 (p=0.0329), Ppbp (p=0.0015), Cxcl1 (p=0.0104) and Ccl6 (p=0.0185). Of note, Ppbp was the most divergently expressed gene (46-fold difference) in Arg1 low vs Arg1 high macrophages, followed by Arg1 itself (14-fold difference). Suggesting a further environmental influence, blood plasma levels of TNF-alpha, Il-1b, Il-4, Il-10, Il-12 and Il-13 were significantly elevated in mice with high PMΦ Arg1 mRNA expression (n=5) compared to those with low expression (n=10). Conclusions: Tet2 is a novel regulator of murine MΦ, induced during MΦ differentiation and M1-polarization. Tet2 loss leads to complex disruption of the M1-M2 spectrum. We are currently exploring whether human TET2 mutations contribute to the abnormal immune environment of myeloid cancers. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yinhe Cai ◽  
Junmao Wen ◽  
Siwen Ma ◽  
Zhexing Mai ◽  
Qunzhang Zhan ◽  
...  

Macrophage polarization plays a vital impact in triggering atherosclerosis (AS) progression and regression. Huang-Lian-Jie-Du Decoction (HLJDD), a famous traditional Chinese decoction, displays notable anti-inflammatory and lipid-lowering effects in different animal models. However, its effects and mechanisms on AS have not been clearly defined. We determined whether HLJDD attenuated atherosclerosis and plaques vulnerability by regulating macrophage polarization in ApoE−/− mice induced by high-fat diet (HFD). Furthermore, we investigated the effects of HLJDD on macrophage polarization in oxidized low-density lipoprotein (ox-LDL) induced RAW264.7 cells. For in vivo assay, compared with the model group, HLJDD ameliorated lipid metabolism, with significantly decreased levels of serum triglyceride, total cholesterol (CHOL), and lipid density lipoprotein. HLJDD suppressed serum tumor necrosis factor α (TNF-α) and IL-1β levels with increased serum IL-10 level, and inhibited mRNA level of NLRP3 inflammasome in carotid tissues. HLJDD enhanced carotid lesion stability by decreasing macrophage infiltration together with increased expression of collagen fibers and α-SMA. Moreover, HLJDD inhibited M1 macrophage polarization, which decreased the expression and mRNA levels of M1 markers [inducible nitric oxide synthase (iNOS) and CD86]. HLJDD enhanced alternatively activated macrophage (M2) activation, which increased the expression and mRNA levels of M2 markers (Arg-1 and CD163). For in vitro assay, HLJDD inhibited foam cell formation in RAW264.7 macrophages disturbed by ox-LDL. Besides, groups with ox-LDL plus HLJDD drug had a lower expression of CD86 and mRNA levels of iNOS, CD86, and IL-1β, but higher expression of CD163 and mRNA levels of Arg-1, CD163, and IL-10 than ox-LDL group. Collectively, our results revealed that HLJDD alleviated atherosclerosis and promoted plaque stability by suppressing M1 polarization and enhancing M2 polarization.


Biomaterials ◽  
2015 ◽  
Vol 37 ◽  
pp. 116-123 ◽  
Author(s):  
Daniela P. Vasconcelos ◽  
Madalena Costa ◽  
Isabel F. Amaral ◽  
Mário A. Barbosa ◽  
Artur P. Águas ◽  
...  

2020 ◽  
Author(s):  
Wei Liu ◽  
Muyu Yu ◽  
Feng Chen ◽  
Dong Xie ◽  
Longqing Wang ◽  
...  

Abstract Background: Many patients suffer from implant loosening after the implantation of titanium alloy caused by immune response to the foreign bodies and this could inhibit osteogenesis, which could possibly give rise to poor osteointegration and there is currently no appropriate solution in clinical practice. Exosomes overexpressing miRNA has been proven to be a suitable candidate for solving this problem. In this study, we explored whether miR-181b could exert beneficial effect on promoting M2 macrophage polarization, thus inhibiting inflammation as well as promoting osteogenesis and elaborated the underlying mechanism in vitro. Furthermore, we aimed to find whether exosomes overexpressing miR-181b (Exo-181b) could enhance osteointegration in vivo.Methods: In vitro and in vivo studies were carried out for assessing the anti-inflammatory and pro-osteogenesis effect of miR-181b. In vitro, ELISA was applied for the detection of the inflammation factors levels including IL-6, TNF-α, as well as IL-10 and the percentage of M1 or M2 polarization was determined by flow cytometry. Also, qRT-PCR was used for the detection of the relative gene expression of the CCR7, CD206, Arg-1, iNOS, VEGF and BMP-2 genes. Western blotting was applied for detecting the protein expression of PRKCD, AKT and p-AKT. In vivo, we established air pouch model for evaluating the effect of Exo-181b on macrophage polarization and distal femoral bone defect model was established for determining the osteointegration effect of Exo-181b by MicroCT, sequential fluorescent labeling and histological analysis. Results: In vitro, we firstly verified that miR-181b significantly enhanced M2 polarization and inhibited inflammation by suppressing PRKCD and activating p-AKT. Then, in vivo, we verified that Exo-181b enhanced M2 polarization, reduced the inflammatory response and enhanced osteointegration. Conclusions: MiR-181b could suppress inflammatory response by regulating the PRKCD/AKT signaling pathway and promoting M2 polarization, which further promoting osteogenesis of hBMSC in vitro and Exo-181b could promote osteointegration in vivo.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Wei Liu ◽  
Muyu Yu ◽  
Feng Chen ◽  
Longqing Wang ◽  
Cheng Ye ◽  
...  

Abstract Background Many patients suffer from implant loosening after the implantation of titanium alloy caused by immune response to the foreign bodies and this could inhibit the following osteogenesis, which could possibly give rise to aseptic loosening and poor osteointegration while there is currently no appropriate solution in clinical practice. Exosome (Exo) carrying miRNA has been proven to be a suitable nanocarrier for solving this problem. In this study, we explored whether exosomes overexpressing miR-181b (Exo-181b) could exert beneficial effect on promoting M2 macrophage polarization, thus inhibiting inflammation as well as promoting osteogenesis and elaborated the underlying mechanism in vitro. Furthermore, we aimed to find whether Exo-181b could enhance osteointegration. Results In vitro, we firstly verified that Exo-181b significantly enhanced M2 polarization and inhibited inflammation by suppressing PRKCD and activating p-AKT. Then, in vivo, we verified that Exo-181b enhanced M2 polarization, reduced the inflammatory response and enhanced osteointegration. Also, we verified that the enhanced M2 polarization could indirectly promote the migration and osteogenic differentiation by secreting VEGF and BMP-2 in vitro. Conclusions Exo-181b could suppress inflammatory response by promoting M2 polarization via activating PRKCD/AKT signaling pathway, which further promoting osteogenesis in vitro and promote osteointegration in vivo. Graphic abstract


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Da-yong Zhang ◽  
Zheng-yang Pan ◽  
Xiong-kai Yu ◽  
Yi-fan Chen ◽  
Chen-hao Gao ◽  
...  

Immunosenescence comprises a set of dynamic changes occurring in innate and adaptive immune systems, and macrophage aging plays an important role in innate and adaptive immunosenescence. However, function and polarization changes in aging macrophages have not been fully evaluated, and no effective method for delaying macrophage senescence is currently available. The results of this study reveal that D-galactose (D-gal) can promote J774A.1 macrophage senescence and induce macrophage M1 polarization differentiation. Bifidobacterium lactis BB-12 can significantly inhibit J774A.1 macrophage senescence induced by D-gal. IL-6 and IL-12 levels in the BB-12 groups remarkably decreased compared with that in the D-gal group, and the M2 marker, IL-10, and Arg-1 mRNA levels increased in the BB-12 group. BB-12 inhibited the expression of p-signal transducer and activator of transcription 1 (STAT1) and promoted p-STAT6 expression. In summary, the present study indicates that BB-12 can attenuate the J774A.1 macrophage senescence and induce M2 macrophage polarization, thereby indicating the potential of BB-12 to slow down immunosenescence and inflamm-aging.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jialiang Zhang ◽  
Fangyang Huang ◽  
Li Chen ◽  
Guoyong Li ◽  
Wenhua Lei ◽  
...  

Background. After myocardial infarction, anti-inflammatory macrophages perform key homeostatic functions that facilitate cardiac recovery and remodeling. Several studies have shown that lactate may serve as a modifier that influences phenotype of macrophage. However, the therapeutic role of sodium lactate in myocardial infarction (MI) is unclear. Methods. MI was established by permanent ligation of the left anterior descending coronary artery followed by injection of saline or sodium lactate. Cardiac function was assessed by echocardiography. The cardiac fibrosis area was assessed by Masson trichrome staining. Macrophage phenotype was detected via qPCR, flow cytometry, and immunofluorescence. Signaling proteins were measured by Western blotting. Results. Sodium lactate treatment following MI improved cardiac performance, enhanced anti-inflammatory macrophage proportion, reduced cardiac myocytes apoptosis, and increased neovascularization. Flow-cytometric analysis results reported that sodium lactate repressed the number of the IL-6+, IL-12+, and TNF-α+ macrophages among LPS-stimulated bone marrow-derived macrophages (BMDMs) and increased the mRNA levels of Arg-1, YM1, TGF-β, and IL-10. Mechanistic studies revealed that sodium lactate enhanced the expression of P-STAT3. Furthermore, a STAT3 inhibitor eliminated sodium lactate-mediated promotion macrophage polarization. Conclusion. Sodium lactate facilitates anti-inflammatory M2 macrophage polarization and protects against MI by regulating P-STAT3.


Sign in / Sign up

Export Citation Format

Share Document