SIRT1 promotes macrophage polarization to enhance efferocytosis by regulating TXNIP/NLRP3 inflammasome pathway

Author(s):  
Qiao Jiang ◽  
Tongda Xu ◽  
Yang Liu ◽  
Hong Zhu ◽  
Yanfeng Ma ◽  
...  

Abstract Objects: This study aimed to determine if SIRT1couldenhance efferocytosis and inhibit apoptosis by modulating cell polarization through the TXNIP/NLRP3 inflammasome pathway in murine peritoneal macrophages.Methods and Results: The effects of SIRT1in peritoneal macrophages were detected using adenovirus-mediated overexpression and knockdown of SIRT1. The apoptotic rate was determined by Annexin V/propidium iodide staining. LDLcholesterol levels were tested by Oil Red O staining and cholesterol testing. Efferocytosisof peritoneal macrophages was determined by fluorescence staining and macrophage markers were determined by flow cytometry, western blot, and ELISA.SIRT1 decreased cholesterol intake andthe apoptotic rate stimulated with ox-LDL in macrophages, which was consistent with upregulation of Bcl-2 and caspase-3 and downregulation of Bax and cleaved caspase-3. SIRT1 increased efferocytosis in macrophages. Expression levels of the M1 macrophage markers IL-6, TNF-α, iNOS, and CD16/32 were decreased, and levels of the M2 markers Dectin-1, IL-10, Arg-1, and CD206 were increased by SIRT1. Moreover, SIRT1 inhibited the ox-LDL stimulated increase in expression of TXNIP and NLRP3 proteins. The effects of SIRT1 were similar to those of TXNIP/NLRP3 inflammasome pathway inhibitor MCC950.Conclusions: These results indicated that SIRT1 exerted an anti-atherosclerosis effect by regulating macrophage polarization to enhance efferocytosis and inhibit apoptosis. Specifically, these effects were generated by downregulation of the TXNIP/NLRP3inflammasome pathway.

Author(s):  
Jing Gong ◽  
Jingbin Li ◽  
Hui Dong ◽  
Guang Chen ◽  
Xin Qin ◽  
...  

Abstract Backgrounds Inflammation is recognized as the key pathological mechanism of type 2 diabetes. The hypoglyceamic effects of berberine (BBR) are related to the inhibition of the inflammatory response, but the mechanism is not completely clear. Methods The inflammatory polarization of Raw264.7 cells and primary peritoneal macrophages were induced by LPS, and then effects and underlying mechanisms of BBR were explored. An inflammatory model was established by LPS treatment at different concentrations for different treatment time. An ELISA assay was used to detect the secretions of TNF-α. RT-PCR was applied to detect M1 inflammatory factors. The F4/80+ ratio and CD11c+ ratio of primary peritoneal macrophages were determined by flow cytometry. The expressions of p-AMPK and TLR4 were detected by Western blot. The cytoplasmic and nuclear distributions of NFκB p65 were observed by confocal microscopy. The binding of TLR4 to MyD88 was tested by CoIP, and the affinity of BBR for TLR4 was assessed by molecular docking. Results Upon exposure to LPS, the secretion of TNF-α and transcription of inflammatory factors in macrophages increased, cell morphology changed and protrusions appeared gradually, the proportion of F4/80+CD11c+ M1 macrophages increased, and the nuclear distribution of NFκB p65 increased. BBR pretreatment partially inhibited the changes mentioned above. However, the expression of TLR4 and p-AMPK did not change significantly after LPS intervention for 3 h. Meanwhile, CoIP showed that the interaction between TLR4 and MyD88 increased, and BBR inhibited the binding. Molecular docking suggested that BBR might interact with TLR4. Conclusions Inflammatory changes were induced in macrophages after LPS stimulation for 3 h, and BBR pretreatment inhibited inflammatory polarization. BBR might interact with TLR4 and disturb TLR4/MyD88/NFκB signalling pathway, and it might be the mechanism by which BBR attenuated inflammation in the early phase.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Keizo Kohno ◽  
Satomi Koya-Miyata ◽  
Akira Harashima ◽  
Takahiko Tsukuda ◽  
Masataka Katakami ◽  
...  

Abstract Background NK-4 has been used to promote wound healing since the early-1950s; however, the mechanism of action of NK-4 is unknown. In this study, we examined whether NK-4 exerts a regulatory effect on macrophages, which play multiple roles during wound healing from the initial inflammatory phase until the tissue regeneration phase. Results NK-4 treatment of THP-1 macrophages induced morphological features characteristic of classically-activated M1 macrophages, an inflammatory cytokine profile, and increased expression of the M1 macrophage-associated molecules CD38 and CD86. Interestingly, NK-4 augmented TNF-α production by THP-1 macrophages in combination with LPS, Pam3CSK4, or poly(I:C). Furthermore, NK-4 treatment enhanced THP-1 macrophage phagocytosis of latex beads. These results indicate that NK-4 drives macrophage polarization toward an inflammatory M1-like phenotype with increased phagocytic activity. Efferocytosis is a crucial event for resolution of the inflammatory phase in wound healing. NK-4-treated THP-1 macrophages co-cultured with apoptotic Jurkat E6.1 (Apo-J) cells switched from an M1-like phenotype to an M2-like phenotype, as seen in the inverted ratio of TNF-α to IL-10 produced in response to LPS. We identified two separate mechanisms that are involved in this phenotypic switch. First, recognition of phosphatidylserine molecules on Apo-J cells by THP-1 macrophages downregulates TNF-α production. Second, phagocytosis of Apo-J cells by THP-1 macrophages and activation of PI3K/Akt signaling pathway upregulates IL-10 production. Conclusion It is postulated that the phenotypic switch from a proinflammatory M1-like phenotype to an anti-inflammatory M2-like phenotype is dysregulated due to impaired efferocytosis of apoptotic neutrophils at the wound site. Our results demonstrate that NK-4 improves phagocytosis of apoptotic cells, suggesting its potential as a therapeutic strategy to resolve sustained inflammation in chronic wounds.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 394.1-394
Author(s):  
A. Hukara ◽  
M. Rudnik ◽  
C. B. Rufer ◽  
O. Distler ◽  
P. Blyszczuk ◽  
...  

Background:Fos-like 2 (Fosl-2) is a transcription factor of the AP-1 family and has a broad range in inducing cellular changes affecting fibrosis and inflammatory responses. Pathological effects of Fosl-2 have been associated with systemic sclerosis (SSc). In addition, increased expression of Fosl-2 has been detected in human SSc monocyte-derived macrophages [1]. Monocytes and macrophages play a central role in activating and propagating acute inflammation followed by pathological fibrosis and organ dysfunction. The classification of the macrophage polarization phenotype can be assigned based on the stimulus, for example into classically-activated M(LPS), and alternatively-activated M(IL-4) macrophages [2]. However, the role of the Fosl-2 transcription factor in macrophage polarization remains elusive.Objectives:To investigate the role of Fosl-2 in macrophage polarization in SSc using Fosl-2 overexpressing transgenic (Fosl-2 tg) mice and human blood-derived macrophages from SSc patients.Methods:Thiogylcolate-elicited peritoneal macrophages were isolated from wild-type (wt) and Fosl-2 tg mice. Human peripheral CD14+ blood-derived monocytes were isolated and differentiated to macrophages (hMDM) from healthy controls and SSc patients. Murine and human macrophages were polarized with LPS (10 ng/ml), LPS + recombinant mouse IFN-γ (10 ng/ml), recombinant mouse, resp. human IL-4 (10 ng/ml) or remained untreated. Macrophage surface marker expression was assessed by flow cytometry using a mouse (F4/80, CD11b, CD86, CD80, CD38, MHCII, CD206, PD-L1, PD-L2, CD36) or human (CD38, CD40, CD86, PD-L2, PD-L1, CD163, CD206) designed polarization panel. Phagocytic activity was detected with pHrodo Red E.coli particles by flow cytometry. Gene expression and secretion of pro- and anti-inflammatory markers were measured by RT-qPCR, standard ELISAs and Griess Assay for nitric oxide production.Results:After LPS stimulation, mRNA levels of IL-1β (p<0.01, n=11-12), TNF-α (p=0.05, n=11-12) and IFN-γ (p<0.05, n=7) were reduced, whereas expression of IL-10 (p<0.05, n=11-12) was enhanced in Fosl-2 tg peritoneal macrophages in comparison to wt cells. Secretion of TNF-α (p<0.01, n=9-11) and nitric oxide (p<0.01, n=9) was impaired in Fosl-2 tg peritoneal macrophages compared to wt cells after LPS stimulation. Peritoneal macrophages were analyzed directly after isolation for macrophage polarization cell surface marker expression. Fosl-2 tg peritoneal macrophages showed an increase in the F4/80+CD11b+PD-L2+CD36+ cell population (p<0.01, n=3-6) compared to peritoneal macrophages from wt mice.The expression of cell surface markers of non-polarized and IL-4 stimulated SSc hMDM (n=17) showed an increased percentage of CD40+CD86+CD206+PD-L2+CD163+ cells (p<0.05) compared to healthy control hMDM (n=7). Phagocytic activity was enhanced in SSc hMDM (n=7) compared to healthy untreated (p<0.05), LPS (p=0.05) and IL-4 (p<0.05) hMDM (n=5).Conclusion:Our animal data indicates a role of Fosl-2 in regulating macrophage polarization with a shift from a classically-activated to an alternatively-activated phenotype. Similarly, SSc hMDM resemble a functional M(IL-4) alternative macrophage phenotype.Thus, maintaining a balanced proportion of classically- and alternatively-activated macrophage phenotypes may be an effective tool to control macrophage function in SSc.References:[1]Moreno-Moral, A., et al., Changes in macrophage transcriptome associate with systemic sclerosis and mediate GSDMA contribution to disease risk. Ann Rheum Dis, 2018. 77(4): p. 596-601.[2]Kania, G., M. Rudnik, and O. Distler, Involvement of the myeloid cell compartment in fibrogenesis and systemic sclerosis. Nat Rev Rheumatol, 2019. 15(5): p. 288-302.Disclosure of Interests:Amela Hukara: None declared, Michal Rudnik: None declared, Chantal Brigitta Rufer: None declared, Oliver Distler Speakers bureau: Actelion, Bayer, Boehringer Ingelheim, Medscape, Novartis, Roche, Menarini, Mepha, MSD, iQone, Pfizer, Consultant of: Abbvie, Actelion, Acceleron Pharma, Amgen, AnaMar, Arxx Therapeutics, Bayer, Baecon Discovery, Blade Therapeutics, Boehringer, CSL Behring, ChemomAb, Corpuspharma, Curzion Pharmaceuticals, Ergonex, Galapagos NV, GSK, Glenmark Pharmaceuticals, Inventiva, Italfarmaco, iQvia, Kymera, Medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Roche, Sanofi, UCB, Lilly, Target BioScience, Pfizer, Grant/research support from: Actelion, Bayer, Boehringer Ingelheim, Kymera Therapeutics, Mitsubishi Tanabe, Przemyslaw Blyszczuk: None declared, Gabriela Kania: None declared


2021 ◽  
Vol 19 ◽  
pp. 205873922110008
Author(s):  
Se Hyang Hong ◽  
Jin Mo Ku ◽  
Ye Seul Lim ◽  
Hyo In Kim ◽  
Yong Cheol Shin ◽  
...  

The objective of this study was to investigate the effects of Cervus nippon var. mantchuricus water extract treated with digestive enzymes (CE) on the promotion of M1 macrophage polarization in murine macrophages. Macrophages polarize either to one phenotype after stimulation with LPS or IFN-γ or to an alternatively activated phenotype that is induced by IL-4 or IL-13. Cell viability of RAW264.7 cells was determined by WST-1 assay. NO production was measured by Griess assay. IL-6, IL-12, TNF-α, and iNOS mRNA levels were measured by RT-PCR. IL-6, IL-12, and IL-10 cytokine levels were determined by ELISA. TLR4/MAPK/NF-κB signaling in RAW264.7 cells was evaluated by western blotting. The level of NF-κB was determined by immunoblotting. CE induced the differentiation of M1 macrophages. CE promoted M1 macrophages to elevate NO production and cytokine levels. CE-stimulated M1 macrophages had enhanced IL-6, IL-12, and TNF-α. CE promoted M1 macrophages to activate TLR4/MAPK/NF-κB phosphorylation. M2 markers were downregulated, while M1 markers were upregulated in murine macrophages by CE. Consequently, CE has immunomodulatory activity and can be used to promote M1 macrophage polarization through the TLR4/MAPK/NF-κB signaling pathways.


2021 ◽  
Author(s):  
Huiwen Tian ◽  
Shumei Lin ◽  
Jing Wu ◽  
Ming Ma ◽  
Jian Yu ◽  
...  

Abstract Corneal transplantation rejection remains a major threat to the success rate in high-risk patients. Given the many side effects presented by traditional immunosuppressants, there is an urgency to clarify the mechanism of corneal transplantation rejection and to identify new therapeutic targets. Kaempferol is a natural flavonoid that has been proven in various studies to possess anti-inflammatory, antioxidant, anticancer, and neuroprotective properties. However, the relationship between kaempferol and corneal transplantation remains largely unexplored. To address this, both in vivo and in vitro, we established a model of corneal allograft transplantation in Wistar rats and an LPS-induced inflammatory model in THP-1 derived human macrophages. In the transplantation experiments, we observed an enhancement in the NLRP3 / IL-1 β axis and in M1 macrophage polarization post-operation. In groups to which kaempferol intraperitoneal injections were administered, this response was effectively reduced. However, the effect of kaempferol was reversed after the application of autophagy inhibitors. Similarly, in the inflammatory model, we found that different concentrations of kaempferol can reduce the LPS-induced M1 polarization and NLRP3 inflammasome activation. Moreover, we confirmed that kaempferol induced autophagy and that autophagy inhibitors reversed the effect in macrophages. In conclusion, we found that kaempferol can inhibit the activation of the NLRP3 inflammasomes by inducing autophagy, thus inhibiting macrophage polarization, and ultimately alleviating corneal transplantation rejection. Thus, our study suggests that kaempferol could be used as a potential therapeutic agent in the treatment of allograft rejection.


2020 ◽  
Author(s):  
Chuan-jiang Liu ◽  
Qiang Fu ◽  
Wenjing Zhou ◽  
Xu Zhang ◽  
Rui Chen ◽  
...  

Abstract Background: Methylprednisolone (MP) is a synthetic corticosteroid with potent anti-inflammatory and antioxidant properties used as therapy for a variety of diseases. The underlying mechanism of MP to reduce acute pancreatitis still needs to be elucidated.Methods: Twenty-four male C57BL/6 mice (6-8 weeks) were used to establish SAP mouse model by administering an intraperitoneal injection of Cae and LPS. Amylase expression levels of serum and PLF were measured with an amylase assay kit. The concentrations of IL-1β and TNF-α in the serum and PLF were detected by ELISA. The level of pancreatic and lung tissue damage and inflammation was assessed by H&E staining and immunofluorescence staining. Western blot and qPCR were used to detect the expression levels of NLRP3, IL-1β and TNF-αin vivo and in vitro.Results: In this study, we found MP, used in the early phase of SAP, decreased the levels of IL-1β and TNF-α in serum and peritoneal lavage fluids (PLF), reduced the level of serum amylase and the expression of MPO in lung tissue, attenuated the pathological injury of the pancreas and lungs in a dose-dependent manner. The expression of NLRP3 and IL-1β in pancreas and lungs was down-regulated significantly depending on the MP concentration. In vitro, MP reduced the levels of IL-1β and TNF-α by down-regulating the expression of NLRP3, IL-1β and p-NF-κB in isolated peritoneal macrophages. Conclusion: MP can attenuate the injury of pancreas and lungs, and the inflammatory response in SAP mice by down-regulating the activation of NF-κB and the NLRP3 inflammasome.


2022 ◽  
Vol 20 (4) ◽  
pp. 71-78
Author(s):  
E. S. Trofimova ◽  
M. V. Zykova ◽  
M. G. Danilets ◽  
A. A. Ligacheva ◽  
E. Yu. Sherstoboev ◽  
...  

Background. Antigen-presenting cells (APCs), especially macrophages, play an important role in the body defense against various pathogens. Their dysfunction and polarization are associated with most inflammatory and autoimmune diseases. The inflammatory process is regulated by activation and / or inhibition of genes differentially expressed by macrophages. Successful correction of inflammation leads firstly to elimination of inflammatory stimuli and then to remodeling and restoration of tissues and organs. It was experimentally confirmed that silvercontaining bionanocomposites based on natural humic substances (HS) obtained from coal of different origin, as well as initial matrices of these HS, are capable of activating pro- and anti-inflammatory properties of macrophages.Aim. To study cytotoxic, pyrogenic, and immunomodulatory properties (arginine balance) of initial HS samples and samples of silver nanoparticles ultradispersed in these HS matrices (HS-AgNPs) in the cell culture of peritoneal macrophages, as well as their effect on pro- and anti-inflammatory properties of APCs.Materials and methods. Cultural and biochemical methods were used in the study.Results. The study showed that the samples CHE-K, CHE-AgNPs, CHS-K, and CHP-K increased M1 macrophage polarization due to stimulation of the NO-synthase activity and inhibition of arginase. The samples CHI-K, CHIAgNPs, CHP-AgNPs, and CHS-AgNPs modulated an alternative M2 or M2-like state of macrophage activation. At the same time, HS are not cytotoxic at effective concentrations, and three out of four studied samples did not contain pyrogenic impurities.Conclusion. The use of HS and their silver-containing bionanocomposites, which have the ability to greatly affect the polarization of antigen-presenting cells, is a promising research area in correction of the inflammatory response for solving an important social and medical problem of treating chronic wounds. 


Blood ◽  
2020 ◽  
Vol 136 (4) ◽  
pp. 501-515 ◽  
Author(s):  
Kunpeng Wu ◽  
Yan Yuan ◽  
Huihui Yu ◽  
Xin Dai ◽  
Shu Wang ◽  
...  

Abstract The diversity of the human microbiome heralds the difference of the impact that gut microbial metabolites exert on allogenic graft-versus-host (GVH) disease (GVHD), even though short-chain fatty acids and indole were demonstrated to reduce its severity. In this study, we dissected the role of choline-metabolized trimethylamine N-oxide (TMAO) in the GVHD process. Either TMAO or a high-choline diet enhanced the allogenic GVH reaction, whereas the analog of choline, 3,3-dimethyl-1-butanol reversed TMAO-induced GVHD severity. Interestingly, TMAO-induced alloreactive T-cell proliferation and differentiation into T-helper (Th) subtypes was seen in GVHD mice but not in in vitro cultures. We thus investigated the role of macrophage polarization, which was absent from the in vitro culture system. F4/80+CD11b+CD16/32+ M1 macrophage and signature genes, IL-1β, IL-6, TNF-α, CXCL9, and CXCL10, were increased in TMAO-induced GVHD tissues and in TMAO-cultured bone marrow–derived macrophages (BMDMs). Inhibition of the NLRP3 inflammasome reversed TMAO-stimulated M1 features, indicating that NLRP3 is the key proteolytic activator involved in the macrophage’s response to TMAO stimulation. Consistently, mitochondrial reactive oxygen species and enhanced NF-κB nuclear relocalization were investigated in TMAO-stimulated BMDMs. In vivo depletion of NLRP3 in GVHD recipients not only blocked M1 polarization but also reversed GVHD severity in the presence of TMAO treatment. In conclusion, our data revealed that TMAO-induced GVHD progression resulted from Th1 and Th17 differentiation, which is mediated by the polarized M1 macrophage requiring NLRP3 inflammasome activation. It provides the link among the host choline diet, microbial metabolites, and GVH reaction, shedding light on alleviating GVHD by controlling choline intake.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3153-3153
Author(s):  
Ashraf Badros ◽  
Sunita Philip ◽  
Patricia Lesho ◽  
Mariola Sadowska ◽  
Dianna Weikel ◽  
...  

Abstract Introduction BRONJ is a complex process that involves interplay of drug effect, bacteria-host immune interactions, and alteration of cytokines and inflammatory mediators leading to impaired healing of the mucosa. In this prospective study, we evaluated MM patients on long term BP therapy to define risk factors and explore cytokine changes in relationship to BP infusion and development of BRONJ. Methods and patients 110 MM patients were enrolled on the study and followed for 18 months. Patients were receiving zoledronic acid infusions once a month (n=75) or every 3 months (n=35) for those in stable remission > 3 years. Patients had clinical and oral evaluations at each visit. Blood samples were collected at baseline and every 6 months. Saliva samples were obtained every 3 months (before and 15 minutes after zoledronic acid infusions). Cytokine expression was analyzed using MULLIPLEX MAP Multiplex Assay (EMD Millipore, MA). Results Median time from MM diagnosis was 3.7 years (range: 2.5-13) for 100 patients; 10 newly diagnosed patients had a median of 7 months (range: 1-9). Median age was 57 years (range: 33-81); 58 were Caucasians, 49 African American, 3 Asians; 68 were males. At study entry, 87 (79%) patients were in remission: CR (n=35, 32%) of them 15 were in CR for > 7 years, PR (n=52, 47%) and PD (n=23, 21%). At study entry, 24 patients were not receiving any MM therapy; most were on maintenance with lenalidomide (n=59), and 10 were receiving induction. While on study, 50 patients progressed and received salvage therapies that included: bortezomib based (n=14), lenalidomide (n=6), carfilzomib (n=16) and other clinical trials (n=14). Thirteen patients died: 9 from complications of relapsed MM and 4 from other causes. Eighteen patients withdrew consent for sample collection and dental evaluations but were followed clinically. Most patients had history of dental procedures (extractions, n=80). The predominant pathology detected during dental evaluations included: moderate/severe periodontal disease (n=45) and gross dental caries (n=15); while on the study, 66 patients continued regular dental cleaning and 10 had dental extractions. During the 18 months of follow up, 14 patients developed new lesions with exposed bone for 8 weeks, meeting the definition of BRONJ. Median time from MM diagnosis to BRONJ was 5.7 years (the 95% CI: 1.9-12.0). BRONJ patients were in remission (n=9), receiving monthly zoledronic acid (n=9), dental extractions (n=9) and three had recurrent BRONJ. There was no association found between BRONJ and diabetes, smoking, or dental pathology. BRONJ treatment was conservative consisting of antibiotics and holding BP therapy. There are 5 patients who continue to have non-healing BRONJ lesions. Saliva and serum samples obtained during this study (baseline, midpoint (6-9 months), end (12-18 months) were assessed for the following cytokines: interleukins (IL)-1β, -6, and -17; TNF-α, IFN-α, TGF-β, MIP-1 α β, MMP-9, Osteopontin, Osteocalcin, RANKL, Osteoprotregerin, VEGF and EGF in 43 patients with ONJ (n=13) and without ONJ (n=30). There were statistically significant lower levels of VEGF and TGF- β (p= .04 and .02, respectively) in the serum overtime in patients who developed BRONJ, figure below. In the saliva cytokines levels were significantly lower in patients who developed BRONJ vs no BRONJ at baseline, before and after zoledronic acid infusions: [Mean pg/ml (SD), p value]: MIP-1 β [14 (3) vs 6(2), p=0.01]; IL-1 β [1824 (1518) vs 72 (38), p=0.04]; IL-6 [15 (4) vs 3 (3), p=0.02]; TNF-α [10 (3) vs 3 (2), p=0.09]. Osteoprotregerin [213 (39) vs 125 (26), p=0.07] was borderline higher in those without BRONJ. Conclusion the incidence of BRONJ remains high at 12% after a median of 5 years of BP use. Dental extraction remains the most significant risk factor for BRONJ. The salivary cytokine repertoire suggests M1 macrophage polarization (recently reported by Zhang et, Clin Cancer Res 2013), in response to injury. The low levels of VEGF and TGF in the serum in response to injury further impair the mucosal healing. Time points 1. Baseline, 2. Midpoint (6-9 months), 3. End of study (12-18 months) Disclosures: No relevant conflicts of interest to declare.


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