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Xie G, Zhang Q, Fang Z, Che L, Lin Y, Xu S, Zhuo Y, Hua L, Jiang X, Li J, Sun M, Zou Y, Huang C, Li L, Wu D, Feng B. Maternal Vitamin D and Inulin Supplementation in Oxidized Oil Diet Improves Growth Performance and Hepatic Innate Immunity in Offspring Mice. Antioxidants (Basel) 2023; 12:1355. [PMID: 37507895 PMCID: PMC10376903 DOI: 10.3390/antiox12071355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/24/2023] [Accepted: 06/25/2023] [Indexed: 07/30/2023] Open
Abstract
Dietary oxidized fat contains harmful materials such as hydrogen peroxide and malondialdehyde (MDA). Excessive oxidized fat intake during pregnancy and lactation not only leads to maternal body injury but also damages offspring health. Our previous study demonstrated that vitamin D (VD) had antioxidative capability in sows. This study was conducted to investigate the effect of maternal VD and inulin supplementation in oxidized oil diet on the growth performance and oxidative stress of their offspring. Sixty 5-month-old C57BL/6N female mice were randomly divided into five groups: Control group (basal diet, n = 12), OF group (oxidized-soybean-oil-replaced diet, n = 12), OFV group (oxidized-soybean-oil-replaced diet + 7000 IU/kg VD, n = 12), OFI group (oxidized-soybean-oil-replaced diet + 5% inulin, n = 12) and OFVI group (oxidized-soybean-oil-replaced diet + 7000 IU/kg VD + 5% inulin, n = 12). Mice were fed with the respective diet during pregnancy and lactation. The offspring were then slaughtered on day 21 of age at weaning. Results showed that a maternal oxidized oil diet impaired body weight and liver weight gain of offspring during lactation compared to the control group, while maternal VD, inulin or VD and inulin mixture supplementation reversed this effect. In addition, the activity of T-AOC in the liver of offspring was lower in the OF group than that in the control group, but could be restored by maternal VD and inulin mixture supplementation. Furthermore, the gene expression of both proinflammatory and anti-inflammatory cytokines, such as Il-6, Tnfα and Il-10, in offspring liver were downregulated by a maternal oxidized oil diet compared with the control group, but they were restored by maternal VD or VD and inulin mixture supplementation. The expressions of Vdr and Cyp27a1 were decreased by a maternal oxidized oil diet compared with the control group, while they could be increased by VD or VD and inulin mixture supplementation. Conclusion: maternal oxidized oil diet intake could impair the growth performance by inducing oxidative stress, but this can be relieved by maternal VD and inulin supplementation.
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Affiliation(s)
- Guangrong Xie
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Qipeng Zhang
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Zhengfeng Fang
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Lianqiang Che
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Yan Lin
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Shengyu Xu
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Yong Zhuo
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Lun Hua
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Xuemei Jiang
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Jian Li
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Mengmeng Sun
- College of Science, Sichuan Agricultural University, Ya'an 625014, China
| | - Yuanfeng Zou
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Chao Huang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Lixia Li
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - De Wu
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Bin Feng
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
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Urso C, Zhou H. Palmitic Acid Lipotoxicity in Microglia Cells Is Ameliorated by Unsaturated Fatty Acids. Int J Mol Sci 2021; 22:ijms22169093. [PMID: 34445796 PMCID: PMC8396597 DOI: 10.3390/ijms22169093] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/16/2021] [Accepted: 08/20/2021] [Indexed: 01/04/2023] Open
Abstract
Obesity and metabolic syndrome are associated with cognitive decline and dementia. Palmitic acid (PA) is increased in the cerebrospinal fluid of obese patients with cognitive impairment. This study was therefore designed to examine fatty acid (FA) lipotoxicity in BV2 microglia cells. We found that PA induced time- and dose-dependent decrease in cell viability and increase in cell death without affecting the cell cycle profile and that PA lipotoxicity did not depend on cell surface free fatty acid receptors but rather on FA uptake. Treatment with sulfosuccinimidyl oleate (SSO), an irreversible inhibitor of fatty acid translocase CD36, significantly inhibited FA uptake in BSA- and PA-treated cells and blocked PA-induced decrease in cell viability. Inhibition of ER stress or treatment with N-acetylcysteine was not able to rescue PA lipotoxicity. Our study also showed that unsaturated fatty acids (UFAs), such as linoleic acid (LA), oleic acid (OA), α-linolenic acid (ALA), and docosahexaenoic acid (DHA), were not lipotoxic but instead protected microglia against PA-induced decrease in cell viability. Co-treatment of PA with LA, OA, and DHA significantly inhibited FA uptake in PA-treated cells. All UFAs tested induced the incorporation of FAs into and the amount of neutral lipids, while PA did not significantly affect the amount of neutral lipids compared with BSA control.
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Southey BR, Bolt CR, Rymut HE, Keever MR, Ulanov AV, Li Z, Rund LA, Johnson RW, Rodriguez-Zas SL. Impact of Weaning and Maternal Immune Activation on the Metabolism of Pigs. Front Mol Biosci 2021; 8:660764. [PMID: 34336923 PMCID: PMC8319725 DOI: 10.3389/fmolb.2021.660764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/21/2021] [Indexed: 12/25/2022] Open
Abstract
Weaning wields environmental, social, and nutritional stresses that are detectable in the blood metabolite levels of the offspring. Prenatal stress in the form of maternal immune activation (MIA) in response to infection, which is associated with health and behavior disorders, also elicits prolonged changes in blood and brain cytokine and metabolite levels of the offspring. The goal of this study was to investigate the effects of weaning and MIA on the offspring’s liver function to advance the understanding of the impact of stressors on peripheral and central nervous systems, physiology, and health. Gas chromatography–mass spectrometry analysis was used to compare the level of hepatic metabolites from 22-day-old pigs (n = 48) evenly distributed among weaning (nursed or weaned), viral MIA exposure (yes or no), and sexes. Weaning effects were detected on 38 metabolites at p-value < 0.05 (28 metabolites at FDR p-value < 0.05), and sex-dependent MIA effects were detected on 11 metabolites. Multiple intermediate and final products of the enriched (FDR p-value < 0.05) glycolysis and gluconeogenesis and pentose phosphate pathways were over-abundant in nursed relative to weaned pigs. The enriched pathways confirm the impact of weaning on hepatic metabolic shift, oxidative stress, and inflammation. Higher levels of the glucogenic amino acid histidine are observed in pigs exposed to MIA relative to controls, suggesting that the role of this metabolite in modulating inflammation may supersede the role of this amino acid as an energy source. The lower levels of cholesterol detected in MIA pigs are consistent with hypocholesterolemia profiles detected in individuals with MIA-related behavior disorders. Our findings underline the impact of weaning and MIA stressors on hepatic metabolites that can influence peripheral and central nervous system metabolic products associated with health and behavior disorders.
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Affiliation(s)
- Bruce R Southey
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Courtni R Bolt
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Haley E Rymut
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Marissa R Keever
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Alexander V Ulanov
- Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Zhong Li
- Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Laurie A Rund
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Rodney W Johnson
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Sandra L Rodriguez-Zas
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, United States.,Illinois Informatics Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States.,Department of Statistics, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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Reuschel E, Toelge M, Haeusler S, Deml L, Seelbach-Goebel B, Solano ME. Perinatal Gram-Positive Bacteria Exposure Elicits Distinct Cytokine Responses In Vitro. Int J Mol Sci 2020; 22:ijms22010332. [PMID: 33396944 PMCID: PMC7795300 DOI: 10.3390/ijms22010332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 12/21/2020] [Indexed: 01/31/2023] Open
Abstract
During pregnancy, infections caused by the gram-positive bacteria Enterococcus faecalis (E. faecalis), Streptococcus agalacticae (S. agalacticae), and Staphylococcus aureus (S. aureus) are major reasons for preterm labor, neonatal prematurity, meningitis, or sepsis. Here, we propose cytokine responses to bacterial infections by the immature perinatal immune system as central players in the pathogenesis of preterm birth and neonatal sepsis. We aimed to close the gap in knowledge about such cytokine responses by stimulating freshly isolated umbilical blood mononuclear cells (UBMC) with lysates of E. faecalis, S. agalacticae, and S. aureus collected from pregnant women in preterm labor. Bacterial lysates and, principally, S. aureus and S. agalacticae distinctly triggered most of the eleven inflammatory, anti-inflammatory, TH1/TH2 cytokines, and chemokines quantified in UBMC culture media. Chemokines depicted the most robust induction. Among them, MIP-1β was further enhanced in UBMC from female compered to male newborn infants. Due to its stability and high levels, we investigated the diagnostic value of IL-8. IL-8 was critically upregulated in cord blood of preterm neonates suffering from infections compared to gestational age-matched controls. Our results provide novel clues about perinatal immunity, underscoring a potential value of IL-8 for the timely detection of infections and suggesting that MIP-1β constitutes an early determinant of sex-specific immunity, which may contribute, e.g., to male’s vulnerability to preterm birth.
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Affiliation(s)
- Edith Reuschel
- University Department of Obstetrics and Gynecology At The Hospital St. Hedwig of The Order of St. John, University of Regensburg, 93049 Regensburg, Germany; (S.H.); (B.S.-G.)
- Correspondence: (E.R.); (M.E.S.)
| | - Martina Toelge
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg, 93053 Regensburg, Germany; (M.T.); (L.D.)
| | - Sebastian Haeusler
- University Department of Obstetrics and Gynecology At The Hospital St. Hedwig of The Order of St. John, University of Regensburg, 93049 Regensburg, Germany; (S.H.); (B.S.-G.)
| | - Ludwig Deml
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg, 93053 Regensburg, Germany; (M.T.); (L.D.)
| | - Birgit Seelbach-Goebel
- University Department of Obstetrics and Gynecology At The Hospital St. Hedwig of The Order of St. John, University of Regensburg, 93049 Regensburg, Germany; (S.H.); (B.S.-G.)
| | - Maria Emilia Solano
- Department of Obstetrics and Feto-Maternal Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- Correspondence: (E.R.); (M.E.S.)
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Zarate MA, Nguyen LM, De Dios RK, Zheng L, Wright CJ. Maturation of the Acute Hepatic TLR4/NF-κB Mediated Innate Immune Response Is p65 Dependent in Mice. Front Immunol 2020; 11:1892. [PMID: 32973783 PMCID: PMC7472845 DOI: 10.3389/fimmu.2020.01892] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/14/2020] [Indexed: 12/27/2022] Open
Abstract
Compared to adults, neonates are at increased risk of infection. There is a growing recognition that dynamic qualitative and quantitative differences in immunity over development contribute to these observations. The liver plays a key role as an immunologic organ, but whether its contribution to the acute innate immune response changes over lifetime is unknown. We hypothesized that the liver would activate a developmentally-regulated acute innate immune response to intraperitoneal lipopolysaccharide (LPS). We first assessed the hepatic expression and activity of the NF-κB, a key regulator of the innate immune response, at different developmental ages (p0, p3, p7, p35, and adult). Ontogeny of the NF-κB subunits (p65/p50) revealed a reduction in Rela (p65) and Nfkb1 (p105, precursor to p50) gene expression (p0) and p65 subunit protein levels (p0 and p3) vs. older ages. The acute hepatic innate immune response to LPS was associated by the degradation of the NF-κB inhibitory proteins (IκBα and IκBβ), and nuclear translocation of the NF-κB subunit p50 in all ages, whereas nuclear translocation of the NF-κB subunit p65 was only observed in the p35 and adult mouse. Consistent with these findings, we detected NF-κB subunit p65 nuclear staining exclusively in the LPS-exposed adult liver compared with p7 mouse. We next interrogated the LPS-induced hepatic expression of pro-inflammatory genes (Tnf, Icam1, Ccl3, and Traf1), and observed a gradually increase in gene expression starting from p0. Confirming our results, hepatic NF-κB subunit p65 nuclear translocation was associated with up-regulation of the Icam1 gene in the adult, and was not detected in the p7 mouse. Thus, an inflammatory challenge induces an NF-κB-mediated hepatic innate immune response activation across all developmental ages, but nuclear translocation of the NF-κB subunit p65 and associated induction of pro-inflammatory genes occurred only after the first month of life. Our results demonstrate that the LPS-induced hepatic innate immune response is developmentally regulated by the NF-κB subunit p65 in the mouse.
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Affiliation(s)
- Miguel A Zarate
- Section of Neonatology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, United States
| | - Leanna M Nguyen
- Section of Neonatology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, United States
| | - Robyn K De Dios
- Section of Neonatology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, United States
| | - Lijun Zheng
- Section of Neonatology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, United States
| | - Clyde J Wright
- Section of Neonatology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, United States
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Butler B, De Dios R, Nguyen L, McKenna S, Ghosh S, Wright CJ. Developmentally Regulated Innate Immune NFκB Signaling Mediates IL-1α Expression in the Perinatal Murine Lung. Front Immunol 2019; 10:1555. [PMID: 31354715 PMCID: PMC6637303 DOI: 10.3389/fimmu.2019.01555] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/21/2019] [Indexed: 12/17/2022] Open
Abstract
Bronchopulmonary dysplasia (BPD) is the most common morbidity complicating premature birth. Importantly, preclinical models have demonstrated that IL-1 receptor antagonism prevents the lung injury and subsequent abnormal development that typically results following perinatal exposure to inflammatory stresses. This receptor is activated by two pro-inflammatory cytokines, IL-1α and IL-1β. While many studies have linked IL-1β to BPD development, IL-1α is relatively under-studied. The objective of our study was to determine whether systemic inflammatory stress induces IL-1α expression in the neonatal lung, and if so, whether this expression is mediated by innate immune NFκB signaling. We found that endotoxemia induced IL-1α expression during the saccular stage of neonatal lung development and was not present in the other neonatal organs or the adult lung. This IL-1α expression was dependent upon sustained pulmonary NFκB activation, which was specific to the neonatal lung. Using in vivo and in vitro approaches, we found that pharmacologic and genetic inhibition of NFκB signaling attenuated IL-1α expression. These findings demonstrate that innate immune regulation of IL-1α expression is developmentally regulated and occurs via an NFκB dependent mechanism. Importantly, the specific role of developmentally regulated pulmonary IL-1α expression remains unknown. Future studies must determine the effect of attenuating innate immune IL-1α expression in the developing lung before adopting broad IL-1 receptor antagonism as an approach to prevent neonatal lung injury.
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Affiliation(s)
- Brittany Butler
- Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States
| | - Robyn De Dios
- Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States
| | - Leanna Nguyen
- Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States
| | - Sarah McKenna
- Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States
| | - Sankar Ghosh
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Clyde J Wright
- Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States
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Le Rouzic V, Wiedinger K, Zhou H. Attenuated mRNA expression of inflammatory mediators in neonatal rat lung following lipopolysaccharide treatment. J Inflamm Res 2012; 5:99-109. [PMID: 23055766 PMCID: PMC3461607 DOI: 10.2147/jir.s33737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Neonates are known to exhibit increased susceptibility to bacterial and viral infections and increasing evidence demonstrates that the increased susceptibility is related to their attenuated immune response to infections. The lung is equipped with an innate defense system involving both cellular and humoral mediators. The present study was performed to characterize the expression of inflammatory mediators in the lung of neonatal rats in comparison with older animals. Rats at postnatal day 1 (P1), P21, and P70 were treated with saline or 0.25 mg/kg lipopolysaccharide (LPS) via intraperitoneal injection. Two hours later, animals were sacrificed and the transcriptional response of key inflammatory mediators and enzyme activity of myeloperoxidase (MPO) in the lung of these animals were examined. LPS-induced messenger RNA (mRNA) expression of pro-inflammatory cytokines, namely interleukin (IL)-1β, IL-6, and tumor necrosis factor-α, antiinflammatory cytokines, namely IL-10 and IL-1 receptor antagonist (IL-1ra), and chemokines, namely macrophage inflammatory protein (MIP)-1β, MIP-2, and monocyte chemotactic protein-1, in P1 lung was much reduced compared to that in P21 and P70 animals at 2 hours postinjection. These data suggest that LPS-induced transcriptional response of cytokines and chemokines was much reduced in P1 lung even though the protein levels of these genes were not ascertained and mRNA levels of these genes may not reflect their final protein levels. MPO activity in LPS-treated P1 lung was also significantly attenuated compared to that in LPS-treated P70 lung, suggesting impaired neutrophil infiltration in P1 lung at 2 hours following LPS treatment. In parallel, the baseline mRNA expression of LPS-binding protein (LBP) in P1 lung was much lower than that in P21 and P70 lungs. While the protein level of LBP was not examined and the mRNA level of LBP may not reflect its final protein level, the reduced transcriptional response of cytokines and chemokines in P1 lung at 2 hours following LPS treatment may be attributed to lower LBP expression in P1 lung as compared to P21 and P70 lungs.
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Affiliation(s)
- Valerie Le Rouzic
- Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA
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Kronforst KD, Mancuso CJ, Pettengill M, Ninkovic J, Power Coombs MR, Stevens C, Otto M, Mallard C, Wang X, Goldmann D, Levy O. A neonatal model of intravenous Staphylococcus epidermidis infection in mice <24 h old enables characterization of early innate immune responses. PLoS One 2012; 7:e43897. [PMID: 22970147 PMCID: PMC3435332 DOI: 10.1371/journal.pone.0043897] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 07/30/2012] [Indexed: 11/28/2022] Open
Abstract
Staphylococcus epidermidis (SE) causes late onset sepsis and significant morbidity in catheterized preterm newborns. Animal models of SE infection are useful in characterizing disease mechanisms and are an important approach to developing improved diagnostics and therapeutics. Current murine models of neonatal bacterial infection employ intraperitoneal or subcutaneous routes at several days of age, and may, therefore, not accurately reflect distinct features of innate immune responses to bacteremia. In this study we developed, validated, and characterized a murine model of intravenous (IV) infection in neonatal mice <24 hours (h) old to describe the early innate immune response to SE. C57BL/6 mice <24 h old were injected IV with 106, 107, 108 colony-forming units (CFU) of SE 1457, a clinical isolate from a central catheter infection. A prospective injection scoring system was developed and validated, with only high quality injections analyzed. Newborn mice were euthanized between 2 and 48 h post-injection and spleen, liver, and blood collected to assess bacterial viability, gene expression, and cytokine production. High quality IV injections demonstrated inoculum-dependent infection of spleen, liver and blood. Within 2 h of injection, SE induced selective transcription of TLR2 and MyD88 in the liver, and increased systemic production of plasma IL-6 and TNF-α. Despite clearance of bacteremia and solid organ infection within 48 h, inoculum-dependent impairment in weight gain was noted. We conclude that a model of IV SE infection in neonatal mice <24 h old is feasible, demonstrating inoculum-dependent infection of solid organs and a pattern of bacteremia, rapid and selective innate immune activation, and impairment of weight gain typical of infected human neonates. This novel model can now be used to characterize immune ontogeny, evaluate infection biomarkers, and assess preventative and therapeutic modalities.
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Affiliation(s)
- Kenny D. Kronforst
- Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, United States of America
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
| | - Christy J. Mancuso
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
| | - Matthew Pettengill
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jana Ninkovic
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | | | - Chad Stevens
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, National Institute of Health, Bethesda, Maryland, United States of America
| | - Carina Mallard
- Physiology, The University of Gothenburg, Gothenburg, Sweden
| | - Xiaoyang Wang
- Physiology, The University of Gothenburg, Gothenburg, Sweden
| | - Donald Goldmann
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ofer Levy
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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