Abstract 11059: Role of Sirtuin 6 in Macrophage Polarization and Cardiac Repair in Diabetes

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Rajarajan A Thandavarayan ◽  
Darukeshwara Joladarashi ◽  
Sahana S Babu ◽  
Garikipati V Srikanth ◽  
Alexander R Mackie ◽  
...  

Clinical and experimental studies provide evidence that metabolic and inflammatory pathways are functionally interconnected to cardiovascular diseases. Dynamic changes in macrophage activation [classical M1 activation (promote inflammation) or alternative M2 activation (promote wound healing)], in response to various stress signals, modulate cardiac physiopathology in diabetes. Sirtuin 6 (SIRT6), a NAD-dependent nuclear deacetylase plays an important role in genomic stability, cellular metabolism, stress response and aging. However, the mechanism by which SIRT6 activity affects macrophage phenotype and cardiac function in diabetes is still unexplored. Mouse bone marrow-derived macrophages (BMM) exposed to high glucose (HG, 25mM D-glucose) showed reduced expression of SIRT6 as compared to low glucose (LG, 5mM D-glucose)- and osmotic control (OC, 5mM D-glucose+20mM D-mannitol)-treated cells, associated with increased expression of proinflammatory cytokine and transcription factors (NFkb, c-JUN, FOXO, SP1 and STAT1). In addition, SIRT6 level was reduced in peritoneal macrophages of both diabetic models (streptozotocin-induced and db/db mice) as compared to non-diabetic mice. SIRT6 knockdown in RAW 264.7 cells exaggerated inflammatory response when exposed to HG. In contrast, IL-4-induced increase in mRNA expression of macrophage M2 phenotype markers like Arg1, Chi4l4, Retnla and IRS-2, but not IRS-1 expression was repressed suggesting that alternative macrophage (M2) phenotype was defective in SIRT6 deficient BM-macrophages under HG condition. SIRT6 protein expression was low in myocardial infarction-induced (MI) and diabetes-affected hearts. Interestingly, mice receiving intramyocardial injection of SIRT6-deficient macrophages showed further deterioration in left ventricular function, post-MI. Taken together, these data highlight a role for SIRT6 in regulating the balance of M1/M2 polarization, therefore, modulate macrophage mediated cardiac repair and regeneration in numerous inflammatory disease states including diabetes

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
G V Velmurugan ◽  
Suresh K Verma ◽  
Alexander R Mackie ◽  
Erin E Vaughan ◽  
Raj kishore ◽  
...  

Clinical and experimental studies provide evidence that metabolic and inflammatory pathways are functionally interconnected to cardiovascular diseases. Dynamic changes in macrophage activation [classical M1 activation (promote inflammation) or alternative M2 activation (promote wound healing)], in response to various signals, modulate tissue pathology in diabetes. Sirtuin 6 (SIRT6), a NAD-dependent nuclear deacetylase plays an important role in genomic stability, cellular metabolism, stress response and aging. However, the mechanism by which SIRT6 activity affects macrophage function in diabetes is still unclear. Mouse bone marrow-derived macrophages (BMM) exposed to high glucose (HG, 25mM D-glucose) showed reduced expression of SIRT6 as compared to low glucose (LG, 5mM D-glucose)- and osmotic control (OC, 5mM D-glucose+20mM D-mannitol)-treated cells. SIRT6 knockdown in RAW 264.7 cells exaggerated inflammatory response in macrophages exposed to high glucose (HG) and in contrast, IL4-induced alternative macrophage (M2) phenotype was defective in SIRT6 deficient BM-macrophages under high glucose condition. SIRT6 protein expression was low in failing (MI-induced) and diabetes-affected hearts. Interestingly, mice receiving intramyocardial injection of SIRT6-deficient macrophages showed further deterioration in LV function, post-MI. Taken together, these data highlighting a role for SIRT6 in regulating both M1 and M2 polarization might have broad implications for numerous inflammatory disease states including insulin resistance and wound healing.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Rui-zhen Sun ◽  
Ying Fan ◽  
Xiao Liang ◽  
Tian-tian Gong ◽  
Qi Wang ◽  
...  

Foam cell formation and macrophage polarization are involved in the pathologic development of atherosclerosis, one of the most important human diseases affecting large and medium artery walls. This study was designed to assess the effects of rapamycin and FTY720 (fingolimod) on macrophages and foam cells. Mouse peritoneal macrophages were collected and treated with rapamycin and FTY720 to study autophagy, polarization, and lipid accumulation. Next, foam cells were formed by oxidizing low-density lipoprotein to observe changes in lipid accumulation, autophagy, and polarization in rapamycin-treated or FTY720-treated foam cells. Lastly, foam cells that had been treated with rapamycin and FTY720 were evaluated for sphingosine 1-phosphate receptor (S1prs) expression. Autophagy microtubule-associated protein 1 light chain 3- (LC3-) II was increased, and classically activated macrophage phenotype markers interleukin- (IL-) 6, cyclooxygenase-2 (COX2), and inducible nitric oxide synthase (iNOS) were increased, whereas alternatively activated macrophage phenotype markers transforming growth factor- (TGF-)β, arginase 1 (Arg1), and mannose receptor C-type 1 (Mrc1) were decreased by rapamycin in peritoneal macrophages. LC3-II was also obviously enhanced, though polarization markers were unchanged in rapamycin-treated foam cells. Moreover, lipid accumulation was inhibited in rapamycin-treated macrophage cells but was unchanged in rapamycin-treated foam cells. For FTY720, LC3-II did not change, whereas TGF-β, Arg1 and Mrc1 were augmented, and IL-6 was suppressed in macrophages. However, LC3-II was increased, and TGF-β, ARG1 and MRC1 were strikingly augmented, whereas IL-6, COX2 and iNOS could be suppressed in foam cells. Furthermore, lipid accumulation was alleviated in FTY720-treated foam cells. Additionally, S1pr1 was markedly decreased in foam cells (P< .05); S1pr2, S1pr3, S1pr4 and S1pr5 were unchanged in rapamycin-treated foam cells. In FTY720-treated foam cells, S1pr3 and S1pr4 were decreased, and S1pr1, S1pr2 and S1pr5 were unchanged. Therefore, we deduced that rapamycin stimulated classically activated macrophages and supressed early atherosclerosis. Rapamycin may also stabilize artery plaques by preventing apoptosis and S1PR1 in advanced atherosclerosis. FTY720 allowed transformation of foam cells into alternatively activated macrophages through the autophagy pathway to alleviate advanced atherosclerosis.


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Ying Lu ◽  
Jianfang Rong ◽  
Yongkang Lai ◽  
Li Tao ◽  
Xiaogang Yuan ◽  
...  

Background and Objective. Helicobacter pylori (H. pylori) is involved in macrophage polarization, but the specific mechanism is not well understood. Therefore, this study is aimed at investigating the effects of the degree of H. pylori infection on the macrophage polarization state and the crosstalk between reactive oxygen species (ROS) and hypoxia-inducible factor 1 α (HIF-1α) in this process. Methods. The expression of CD86, CD206, and HIF-1α in the gastric mucosa was evaluated through immunohistochemistry. RAW 264.7 cells were cocultured with H. pylori at various multiplicities of infection (MOIs), and iNOS, CD86, Arg-1, CD206, and HIF-1α expression was detected by Western blot, PCR, and ELISA analyses. ROS expression was detected with the fluorescent probe DCFH-DA. Macrophages were also treated with the ROS inhibitor NAC or HIF-1α inhibitor YC-1. Results. Immunohistochemical staining revealed that the macrophage polarization state was associated with the progression of gastric lesions and state of H. pylori infection. The MOI of H. pylori affected macrophage polarization, and H. pylori enhanced the expression of ROS and HIF-1α in macrophages. A low MOI of H. pylori promoted both the M1 and M2 phenotypes, while a high MOI suppressed the M2 phenotype. Furthermore, ROS inhibition attenuated HIF-1α expression and switched macrophage polarization from M1 to M2. However, HIF-1α inhibition suppressed ROS expression and inhibited both the M1 phenotype and the M2 phenotype. Inhibition of ROS or HIF-1α also suppressed the activation of the Akt/mTOR pathway, which was implicated in H. pylori-induced macrophage polarization. Conclusions. Macrophage polarization is associated with the progression of gastric lesions and state of H. pylori infection. The MOI of H. pylori influences the macrophage polarization state. Crosstalk between ROS and HIF-1α regulates H. pylori-induced macrophage polarization via the Akt/mTOR pathway.


Author(s):  
Mingming Liu ◽  
Meng Yan ◽  
Jinlong He ◽  
Huizhen Lv ◽  
Zhipeng Chen ◽  
...  

Rationale: Timely inhibition of inflammation and initiation of resolution are important to repair injured tissues. Mammalian STE20-like protein kinase 1/2 (MST1/2) acts as a regulator of macrophage-associated immune responses to bacterial infections. However, the role of MST1/2 in regulating macrophage phenotype and function in myocardial infarction (MI) remains unclear. Objective: To determine the function and underlying mechanism of macrophage MST1/2 in cardiac repair post-MI. Methods and Results: Using LysMCre-mediated Mst1/2-deficient mice, we found that MST1 deficiency exacerbated cardiac dysfunction after MI. Single-cell RNA sequencing assay indicated that the effect was attributed to a shift of macrophage subtypes from those expressing Cxcl2 and Cd163 toward Ccl2 and Ccl4 expression. Mass spectrometry identified leukotriene B4 (LTB4) as the lipid mediator that was upregulated in the absence of MST1. We found that MST1 phosphorylated 5-lipoxygenase (5-LOX) at its T218 residue, disrupting the interaction between 5-LOX and 5-LOX-activating protein, resulting in a reduction of LTB4 production. In contrast, a 5-LOXT218A variant showed no response to MST1. Moreover, treatment of peritoneal macrophages with LTB4 or medium conditioned by Mst1-deficient macrophages resulted in high Ccl2 and Ccl4 expression and low Cxcl2 and Cd163 expression, except when the cells were co-treated with the LTB4 receptor 1 (BLT1) antagonist CP105696. Furthermore, CP105696 ameliorated cardiac dysfunction in LysMCre-mediated Mst1/2-deficient mice and enhanced cardiac repair in wild-type mice treated with XMU-MP-1 after MI. Conclusions: Taken together, our results demonstrate that inhibition of MST1/2 impaired post-MI repair through activating macrophage 5-LOX-LTB4-BLT1 axis.


Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1603
Author(s):  
Seon Yeong Ji ◽  
Hyesook Lee ◽  
Hyun Hwangbo ◽  
Su-Hyun Hong ◽  
Hee-Jae Cha ◽  
...  

Antimicrobial peptides (AMPs) are components of the innate immune system and form the first defense against pathogens for various organisms. In the present study, we assessed whether CSP32, a novel AMP oligomer of bacitracin isolated from a strain of Bacillus spp., regulates the polarization of murine macrophage-like RAW 264.7 cells. CSP32 stimulated phagocytosis while inducing the appearance of the typical M1 polarized macrophage phenotype; these M1 macrophages play a role in host defense against pathogens. Furthermore, our results showed that CSP32 enhanced the expression and production of pro-inflammatory mediators, such as cytokines and chemokines. In addition, the CSP32-stimulated inflammatory mediators were induced mainly by the mitogen-activated protein kinase/nuclear factor kappa B (MAPK/NF-κB) signaling pathway during M1 macrophage polarization. In particular, CSP32 markedly increased the numbers of Ca2+-positive macrophages while upregulating phospholipase C and activating protein kinase Cε. Furthermore, the inhibition of intracellular Ca2+ by BAPTA-AM, a Ca2+ chelator, significantly suppressed the CSP32-mediated phagocytosis, inflammatory mediator production, and NF-κB activation. In conclusion, our data suggested that CSP32-stimulated M1 macrophage polarization is dependent on the calcium signaling pathway and may result in enhanced immune capacities.


2021 ◽  
Vol 8 ◽  
Author(s):  
Xun Wu ◽  
Di Wang ◽  
Kele Qin ◽  
Chukwuemeka Daniel Iroegbu ◽  
Kun Xiang ◽  
...  

Objective: We investigated the potency of cardiac repair based on echocardiography-guided multiple percutaneous left ventricular intramyocardial injection of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) after myocardial infarction (MI).Methods: Mice with surgically induced MI were randomly divided into three groups (n = 8 in each group) and subjected to echocardiography-guided percutaneous left ventricular infarcted border injection of hiPSC-CMs (single dose; 10 μl 3 × 105 cells) or repeated injections of hiPSC-CMs at post-MI weeks 1 and 2 (multiple doses). The sham group of animals underwent all surgical procedures necessary for MI induction except for ligation. Then 4 weeks after MI, heart function was measured with transthoracic echocardiography. Engraftment was evaluated through the detection of human-specific cardiac troponin T. Infarct size and collagen volume were calculated with Sirius Red/Fast Green staining. Angiogenesis was evaluated with isolectin B4 staining. Cardiac remodeling was evaluated from the cardiomyocyte minimal fiber diameter in the infarcted border zone. Apoptosis was detected via TdT-mediated dUTP Nick-End Labeling (TUNEL) staining in cardiomyocytes from the infarcted border zone.Results: No mice died after echocardiography-guided percutaneous left ventricular intramyocardial injection. hiPSC-CMs were about nine-fold higher in the multiple-dose group at week 4 compared to the single-dose group. Multiple-dose transplantation was associated with significant improvement in left ventricular function, infarct size, angiogenesis, cardiac remodeling, and cardiomyocyte apoptosis.Conclusion: Echocardiography-guided multiple percutaneous left ventricular intramyocardial injection is a feasible, satisfactory, repeatable, relatively less invasive, and effective method of delivering cell therapy. The delivery of hiPSC-CMs indicates a novel therapy for MI.


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


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A923-A923
Author(s):  
Víctor Cortés-Morales ◽  
Juan Montesinos ◽  
Luis Chávez-Sánchez ◽  
Sandra Espíndola-Garibay ◽  
Alberto Monroy-García ◽  
...  

BackgroundMacrophages are immunological cells that sense microenvironmental signals that may result in the polarized expression of either proinflammatory (M1) or anti-inflammatory (M2) phenotype.1 Macrophages M2 are present in tumoral microenvironment and their presence in patients with cervical cancer (CeCa) is related with less survival.2Mesenchymal Stromal Cells (MSCs) are also present in tumor microenvironment of cervical cancer (CeCa-MSC), which have shown immunoregulatory effects over CD8 T cells, decreasing their cytotoxic effect against tumoral cells.3 Interestingly, MSCs from bone marrow (BM-MSC) decrease M1 and increase M2 macrophage polarization in an in vitro coculture system.4 Macrophages and MSCs are present in microenvironment of cervical cancer, however it is unknown if MSCs play a role in macrophage polarization. In the present study, we have evaluated the immunoregulatory capacity of CeCa-MSCs to induce macrophage polarization.MethodsCD14 monocytes were isolated from peripheral blood and cultivated in the absence or presence of MSCs from BM, normal cervix (NCx) and CeCa. Two culture conditions were included, in the presence of induction medium to favors M1 (GM-CSF, LPS and IFNg) or M2 (M-CSF, IL-4 and IL-13) macrophage polarization. M1 (HLA-DR, CD80, CD86 and IFNg) or M2 (CD14, CD163, CD206, IDO and IL-10) macrophage molecular markers were evaluated by flow cytometry. Finally, we evaluated concentration of IL-10 and TNFa in conditioned medium form all coculture conditions.ResultsWe observed that CeCa-MSCs and BM-MSCs in presence of M1 induction medium, decreased M1 macrophage markers (HLA-II, CD80, CD86 and IFNg), and increase the expression of CD14 (M2 macrophage marker). Interestingly, in presence of M2 induction medium, BM-MSCs and CaCe-MSCs but not CxN-MSC increased CD163, CD206, IDO and IL-10 (M2 macrophage markers). We observed a decreased concentration of TNFa in the supernatant medium from all cocultures with MSCs, but only in presence of CeCa-MSCs, increased IL-10 concentration was detected in such cocultures.ConclusionsIn contrast to NCx-MSCs, CeCa-MSCs similarly to BM-MSCs have in vitro capacity to decrease M1 and increase M2 macrophage phenotype.AcknowledgementsAcknowledgments The authors are indebted to gratefully acknowledge to CONACYT (Grant No. 272793) and IMSS (Grant no. 1731) for support to Juan J. Montesinos research.ReferencesMartinez FO, Gordon S. The M1 and M2 paradigm of macrophage activation: time for reassessment. F1000Prime Rep 2014;6-13.Petrillo M, Zannoni GF, Martinelli E, et al. Polarization of tumor-associated macrophages toward M2 phenotype correlates with poor response to chemoradiation and reduced survival in patients with locally advanced cervical cancer. PLoS One 2015;10: e0136654.Montesinos JJ, Mora-García Mde L, et al. In vitro evidence of the presence of mesenchymal stromal cells in cervical cancer and their role in protecting cancer cells from cytotoxic T cell activity. Stem Cells Dev 2013;22:2508-2519.Vasandan AB, Jahnavi S, Shashank C. Human mesenchymal stem cells program macrophage plasticity by altering their metabolic status via a PGE 2-dependent mechanism. Sci Rep 2016;6:38308.


2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Hua Wang ◽  
Xiaoyan Zhang ◽  
Shauna M. Dorsey ◽  
Jeremy R. McGarvey ◽  
Kenneth S. Campbell ◽  
...  

Myocardial contractility of the left ventricle (LV) plays an essential role in maintaining normal pump function. A recent ex vivo experimental study showed that cardiomyocyte force generation varies across the three myocardial layers of the LV wall. However, the in vivo distribution of myocardial contractile force is still unclear. The current study was designed to investigate the in vivo transmural distribution of myocardial contractility using a noninvasive computational approach. For this purpose, four cases with different transmural distributions of maximum isometric tension (Tmax) and/or reference sarcomere length (lR) were tested with animal-specific finite element (FE) models, in combination with magnetic resonance imaging (MRI), pressure catheterization, and numerical optimization. Results of the current study showed that the best fit with in vivo MRI-derived deformation was obtained when Tmax assumed different values in the subendocardium, midmyocardium, and subepicardium with transmurally varying lR. These results are consistent with recent ex vivo experimental studies, which showed that the midmyocardium produces more contractile force than the other transmural layers. The systolic strain calculated from the best-fit FE model was in good agreement with MRI data. Therefore, the proposed noninvasive approach has the capability to predict the transmural distribution of myocardial contractility. Moreover, FE models with a nonuniform distribution of myocardial contractility could provide a better representation of LV function and be used to investigate the effects of transmural changes due to heart disease.


Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 855
Author(s):  
Ekaterina A. Litvinova ◽  
Victoria D. Bets ◽  
Natalya A. Feofanova ◽  
Olga V. Gvozdeva ◽  
Kseniya M. Achasova ◽  
...  

Intestinal mucus protects epithelial and immune cells from the gut resident microorganisms, and provides growth-promoting factors as mucus-derived O-glycans for beneficial bacteria. A lack of intestinal protective mucus results in changes in the commensal microflora composition, mucosal immune system reprogramming, and inflammation. Previous work has shown that fucose, the terminal glycan chain component of the intestinal glycoprotein Mucin2, and fucoidan polysaccharides have an anti-inflammatory effect in some mouse models of colitis. This study evaluates the effect of fucose on reproductive performance in heterozygous mutant Muc2 female mice. We found that even though Muc2+/− females are physiologically indistinguishable from C57Bl/6 mice, they have a significantly reduced reproductive performance upon dietary fucose supplementation. Metagenomic analysis reveals that the otherwise healthy wild-type siblings of Muc2−/− animals have reduced numbers of some of the intestinal commensal bacterial species, compared to C57BL/6 mice. We propose that the changes in beneficial microflora affect the immune status in Muc2+/− mice, which causes implantation impairment. In accordance with this hypothesis, we find that macrophage polarization during pregnancy is impaired in Muc2+/− females upon addition of fucose. Metabolic profiling of peritoneal macrophages from Muc2+/− females reveals their predisposition towards anaerobic glycolysis in favor of oxidative phosphorylation, compared to C57BL/6-derived cells. In vitro experiments on phagocytosis activity and mitochondrial respiration suggest that fucose affects oxidative phosphorylation in a genotype-specific manner, which might interfere with implantation depending on the initial status of macrophages. This hypothesis is further confirmed in BALB/c female mice, where fucose caused pregnancy loss and opposed implantation-associated M2 macrophage polarization. Taken together, these data suggest that intestinal microflora affects host immunity and pregnancy outcome. At the same time, dietary fucose might act as a differential regulator of macrophage polarization during implantation, depending on the immune status of the host.


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