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Oosting A, Harvey L, Ringler S, van Dijk G, Schipper L. Beyond ingredients: Supramolecular structure of lipid droplets in infant formula affects metabolic and brain function in mouse models. PLoS One 2023; 18:e0282816. [PMID: 37531323 PMCID: PMC10395839 DOI: 10.1371/journal.pone.0282816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/28/2023] [Indexed: 08/04/2023] Open
Abstract
Human milk beneficially affects infant growth and brain development. The supramolecular structure of lipid globules in human milk i.e., large lipid globules covered by the milk fat globule membrane, is believed to contribute to this effect, in addition to the supply of functional ingredients. Three preclinical (mouse) experiments were performed to study the effects of infant formula mimicking the supramolecular structure of human milk lipid globules on brain and metabolic health outcomes. From postnatal day 16 to 42, mouse offspring were exposed to a diet containing infant formula with large, phospholipid-coated lipid droplets (structure, STR) or infant formula with the same ingredients but lacking the unique structural properties as observed in human milk (ingredient, ING). Subsequently, in Study 1, the fatty acid composition in liver and brain membranes was measured, and expression of hippocampal molecular markers were analyzed. In Study 2 and 3 adult (Western-style diet-induced) body fat accumulation and cognitive function were evaluated. Animals exposed to STR compared to ING showed improved omega-3 fatty acid accumulation in liver and brain, and higher expression of brain myelin-associated glycoprotein. Early exposure to STR reduced fat mass accumulation in adulthood; the effect was more pronounced in animals exposed to a Western-style diet. Additionally, mice exposed to STR demonstrated better memory performance later in life. In conclusion, early life exposure to infant formula containing large, phospholipid-coated lipid droplets, that are closer to the supramolecular structure of lipid globules in human milk, positively affects adult brain and metabolic health outcomes in pre-clinical animal models.
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Affiliation(s)
| | | | | | - Gertjan van Dijk
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Lidewij Schipper
- Danone Nutricia Research, Utrecht, The Netherlands
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
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Muñoz EM. Microglia in Circumventricular Organs: The Pineal Gland Example. ASN Neuro 2022; 14:17590914221135697. [PMID: 36317305 PMCID: PMC9629557 DOI: 10.1177/17590914221135697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The circumventricular organs (CVOs) are unique areas within the central nervous system. They serve as a portal for the rest of the body and, as such, lack a blood-brain barrier. Microglia are the primary resident immune cells of the brain parenchyma. Within the CVOs, microglial cells find themselves continuously challenged and stimulated by local and systemic stimuli, even under steady-state conditions. Therefore, CVO microglia in their typical state often resemble the activated microglial forms found elsewhere in the brain as they are responding to pathological conditions or other stressors. In this review, I focus on the dynamics of CVO microglia, using the pineal gland as a specific CVO example. Data related to microglia heterogeneity in both homeostatic and unhealthy environments are presented and discussed, including those recently generated by using advanced single-cell and single-nucleus technology. Finally, perspectives in the CVO microglia field are also included.Summary StatementMicroglia in circumventricular organs (CVOs) continuously adapt to react differentially to the diverse challenges they face. Herein, I discuss microglia heterogeneity in CVOs, including pineal gland. Further studies are needed to better understand microglia dynamics in these unique brain areas. .
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Affiliation(s)
- Estela M. Muñoz
- Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos (IHEM), Universidad Nacional de Cuyo (UNCuyo), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina,Estela M. Muñoz, IHEM-UNCuyo-CONICET, Parque General San Martin, Ciudad de Mendoza, M5502JMA, Mendoza, Argentina.
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Goldwater PN. The Science (or Nonscience) of Research Into Sudden Infant Death Syndrome (SIDS). Front Pediatr 2022; 10:865051. [PMID: 35498810 PMCID: PMC9051368 DOI: 10.3389/fped.2022.865051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
UNLABELLED This Viewpoint paper presents a timely and constructive critique of mainstream SIDS research. It is concerning that twenty-first century medical science has not provided an answer to the tragic enigma of SIDS. The paper helps explain why this is so and illustrates possible shortcomings in the investigation of Sudden Infant Death Syndrome/Sudden Unexplained Infant Death (SIDS/SUID) by mainstream researchers. Mainstream findings are often based on questionable and dogmatic assumptions that return to founding notions such as the Triple Risk Hypothesis and the contention that the mechanisms underlying SIDS/SUID are heterogeneous in nature. The paper illustrates how the pathological findings in SIDS have been under-investigated (or ignored) and that key epidemiological risk factors have slipped from memory. This apparent amnesia has resulted in failure to use these established SIDS facts to substantiate the significance of various neuropathological, neurochemical, or other research findings. These unsupported findings and their derivative hypotheses are therefore ill-founded and lack scientific rigor. CONCLUSION The deficits of SIDS "science" revealed in this paper explain why the SIDS enigma has not yet been solved. To make progress in understanding SIDS, it is important that researchers, as scientists, uphold standards of research. Encouragement for new directions of research is offered.
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Affiliation(s)
- Paul Nathan Goldwater
- Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, Australia
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Machaalani R, Vivekanandarajah A, Despotovski V, Rodriguez M, Waters KA. Morphology of the Dentate Gyrus in a Large Cohort of Sudden Infant Deaths-Interrelation Between Features but Not Diagnosis. J Neuropathol Exp Neurol 2021; 81:61-75. [PMID: 34865047 DOI: 10.1093/jnen/nlab119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Morphological differences in the dentate gyrus (DG) have been reported in sudden unexpected deaths in infancy (SUDI), with the feature of focal granule cell (GC) bilamination (FGCB) reported as increased in unexplained SUDI, including sudden infant death syndrome (SIDS), compared with explained SUDI (eSUDI). However, it remains to be determined how these morphologies relate to each other and their extent along the anteroposterior length. This retrospective study evaluated the prevalence of FGCB, single or clustered ectopic GCs, granule cell dispersion (GCD), heterotopia, hyperconvolution, gaps, thinning, blood vessel dissection (BVD), and cuffing (BV cuffing), in an Australian SUDI cohort, and compared the prevalence of these features in eSUDI and unexplained SUDI. We analyzed 850 formalin-fixed paraffin-embedded serial and subserial sections of the hippocampus at the level of the lateral geniculate nucleus from 90 infants, and identified GCD in 97% of infants, single ectopic cells, hyperconvolution, thinning, and BVD in 60%-80%, heterotopia in 36%, gaps, clusters of ectopic cells and BV cuffing in 9%-15%, and FGCB in 18%. These features are clustered within 3-5 serial sections. The presence of FGCB correlated with single ectopic GCs and hyperconvolution. There were no differences in the prevalence of these features between unexplained SUDI (n = 74) and eSUDI (n = 16). Our findings highlight that DG morphological features are highly localized, extending 14-35 µm at their focal location(s) along the anteroposterior length. Consequently, multiple sections along the longitudinal extent are required to identify them. No feature differentiated SUDI from eSUDI in our cohort, thus we cannot conclude that any of these features are abnormal and it remains to be determined their functional significance.
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Affiliation(s)
- Rita Machaalani
- From the Discipline of Medicine, Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia (RM, AV, VD, KAW); Discipline of Child and Adolescent Health, Children's Hospital at Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia (RM, KAW); and Discipline of Pathology, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia (MR)
| | - Arunnjah Vivekanandarajah
- From the Discipline of Medicine, Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia (RM, AV, VD, KAW); Discipline of Child and Adolescent Health, Children's Hospital at Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia (RM, KAW); and Discipline of Pathology, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia (MR)
| | - Vanessa Despotovski
- From the Discipline of Medicine, Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia (RM, AV, VD, KAW); Discipline of Child and Adolescent Health, Children's Hospital at Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia (RM, KAW); and Discipline of Pathology, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia (MR)
| | - Michael Rodriguez
- From the Discipline of Medicine, Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia (RM, AV, VD, KAW); Discipline of Child and Adolescent Health, Children's Hospital at Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia (RM, KAW); and Discipline of Pathology, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia (MR)
| | - Karen A Waters
- From the Discipline of Medicine, Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia (RM, AV, VD, KAW); Discipline of Child and Adolescent Health, Children's Hospital at Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia (RM, KAW); and Discipline of Pathology, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia (MR)
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Shin TH, Lee DY, Manavalan B, Basith S, Na YC, Yoon C, Lee HS, Paik MJ, Lee G. Silica-coated magnetic nanoparticles activate microglia and induce neurotoxic D-serine secretion. Part Fibre Toxicol 2021; 18:30. [PMID: 34384435 PMCID: PMC8359100 DOI: 10.1186/s12989-021-00420-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 07/13/2021] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Nanoparticles have been studied for brain imaging, diagnosis, and drug delivery owing to their versatile properties due to their small sizes. However, there are growing concerns that nanoparticles may exert toxic effects in the brain. In this study, we assessed direct nanotoxicity on microglia, the resident macrophages of the central nervous system, and indirect toxicity on neuronal cells exerted by silica-coated magnetic nanoparticles containing rhodamine B isothiocyanate dye [MNPs@SiO2(RITC)]. METHODS We investigated MNPs@SiO2(RITC)-induced biological changes in BV2 murine microglial cells via RNA-sequencing-based transcriptome analysis and gas chromatography-mass spectrometry-based intracellular and extracellular amino acid profiling. Morphological changes were analyzed by transmission electron microscopy. Indirect effects of MNPs@SiO2(RITC) on neuronal cells were assessed by Transwell-based coculture with MNPs@SiO2(RITC)-treated microglia. MNPs@SiO2(RITC)-induced biological changes in the mouse brain in vivo were examined by immunohistochemical analysis. RESULTS BV2 murine microglial cells were morphologically activated and the expression of Iba1, an activation marker protein, was increased after MNPs@SiO2(RITC) treatment. Transmission electron microscopy analysis revealed lysosomal accumulation of MNPs@SiO2(RITC) and the formation of vesicle-like structures in MNPs@SiO2(RITC)-treated BV2 cells. The expression of several genes related to metabolism and inflammation were altered in 100 µg/ml MNPs@SiO2(RITC)-treated microglia when compared with that in non-treated (control) and 10 µg/ml MNPs@SiO2(RITC)-treated microglia. Combined transcriptome and amino acid profiling analyses revealed that the transport of serine family amino acids, including glycine, cysteine, and serine, was enhanced. However, only serine was increased in the growth medium of activated microglia; especially, excitotoxic D-serine secretion from primary rat microglia was the most strongly enhanced. Activated primary microglia reduced intracellular ATP levels and proteasome activity in cocultured neuronal cells, especially in primary cortical neurons, via D-serine secretion. Moreover, ubiquitinated proteins accumulated and inclusion bodies were increased in primary dopaminergic and cortical neurons cocultured with activated primary microglia. In vivo, MNPs@SiO2(RITC), D-serine, and ubiquitin aggresomes were distributed in the MNPs@SiO2(RITC)-treated mouse brain. CONCLUSIONS MNPs@SiO2(RITC)-induced activation of microglia triggers excitotoxicity in neurons via D-serine secretion, highlighting the importance of neurotoxicity mechanisms incurred by nanoparticle-induced microglial activation.
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Affiliation(s)
- Tae Hwan Shin
- Department of Physiology, Ajou University School of Medicine, 206 World cup-ro, 16499 Suwon, Republic of Korea
| | - Da Yeon Lee
- Department of Physiology, Ajou University School of Medicine, 206 World cup-ro, 16499 Suwon, Republic of Korea
| | - Balachandran Manavalan
- Department of Physiology, Ajou University School of Medicine, 206 World cup-ro, 16499 Suwon, Republic of Korea
| | - Shaherin Basith
- Department of Physiology, Ajou University School of Medicine, 206 World cup-ro, 16499 Suwon, Republic of Korea
| | - Yun-Cheol Na
- Western Seoul Center, Korea Basic Science Institute, 150 Bugahyeon-ro, 03759 Seoul, Republic of Korea
| | - Cheolho Yoon
- Ochang Center, Korea Basic Science Institute, 162 Yeongudanji-ro, 28119 Cheongju, Republic of Korea
| | - Hyeon-Seong Lee
- College of Pharmacy, Sunchon National University, 255 Jungang-ro, 57922 Suncheon, Republic of Korea
| | - Man Jeong Paik
- College of Pharmacy, Sunchon National University, 255 Jungang-ro, 57922 Suncheon, Republic of Korea
| | - Gwang Lee
- Department of Physiology, Ajou University School of Medicine, 206 World cup-ro, 16499 Suwon, Republic of Korea
- Department of Molecular Science and Technology, Ajou University, 206 World cup-ro, 16499 Suwon, Republic of Korea
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Immunostaining for NeuN Does Not Show all Mature and Healthy Neurons in the Human and Pig Brain: Focus on the Hippocampus. Appl Immunohistochem Mol Morphol 2021; 29:e46-e56. [PMID: 33710124 DOI: 10.1097/pai.0000000000000925] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 01/27/2021] [Indexed: 01/20/2023]
Abstract
Neuronal nuclei (NeuN) is a neuron-specific nuclear protein, reported to be stably expressed in most postmitotic neurons of the vertebrate nervous system. Reduced staining has been interpreted by some to indicate loss of cell viability in human studies, while others suggest this may be because of changes in the antigenicity of the target epitope. Preliminary studies in our laboratory found low immunostaining for the NeuN antibody on formalin fixed and paraffin embedded (FFPE) human brain tissue. We report on the techniques and results used to enhance the staining for NeuN in that tissue. In parallel, we stained NeuN in piglet brain tissue, sourced from an experimental model where methodological parameters, including those for tissue fixation and storage, were tightly controlled. In human FFPE brain tissue, we were unable to enhance NeuN immunostaining to a degree sufficient for cell counting. In contrast, we found consistently high levels of staining in the piglet brain tissue. We conclude that processes used for fixation and storage of human FFPE brain tissue are responsible for the reduced staining. These results emphasize that a cautionary approach should be taken when interpreting NeuN staining outcomes in human FFPE brain tissue.
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