Microglial Morphology Across Distantly Related Species: Phylogenetic, Environmental and Age Influences on Microglia Reactivity and Surveillance States

Microglial immunosurveillance of the brain parenchyma to detect local perturbations in homeostasis, in all species, results in the adoption of a spectrum of morphological changes that reflect functional adaptations. Here, we review the contribution of these changes in microglia morphology in distantly related species, in homeostatic and non-homeostatic conditions, with three principal goals (1): to review the phylogenetic influences on the morphological diversity of microglia during homeostasis (2); to explore the impact of homeostatic perturbations (Dengue virus challenge) in distantly related species (Mus musculus and Callithrix penicillata) as a proxy for the differential immune response in small and large brains; and (3) to examine the influences of environmental enrichment and aging on the plasticity of the microglial morphological response following an immunological challenge (neurotropic arbovirus infection). Our findings reveal that the differences in microglia morphology across distantly related species under homeostatic condition cannot be attributed to the phylogenetic origin of the species. However, large and small brains, under similar non-homeostatic conditions, display differential microglial morphological responses, and we argue that age and environment interact to affect the microglia morphology after an immunological challenge; in particular, mice living in an enriched environment exhibit a more efficient immune response to the virus resulting in earlier removal of the virus and earlier return to the homeostatic morphological phenotype of microglia than it is observed in sedentary mice.

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Evaluating the Effects of Surotomycin Treatment on Clostridium difficile Toxin A and B Production, Immune Response, and Morphological Changes

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00211-16 ◽

2016 ◽

Vol 60 (6) ◽

pp. 3519-3523 ◽

Cited By ~ 8

Author(s):

Bradley T. Endres ◽

Eugénie Bassères ◽

Mohammed Khaleduzzaman ◽

M. Jahangir Alam ◽

Laurent Chesnel ◽

...

Keyword(s):

Immune Response ◽

Clostridium Difficile ◽

Morphological Changes ◽

Toxin Production ◽

Morphological Data ◽

Growth Media ◽

Toxin A ◽

Content Type ◽

Cyclic Lipopeptide ◽

The Impact

Surotomycin is a cyclic lipopeptide in development forClostridium difficile-associated diarrhea. This study aimed to assess the impact of surotomycin exposure onC. difficiletoxin A and B concentrations and the associated changes in immune response in comparison to vancomycin and metronidazole. Time-kill curve assays were performed using strain R20291 (BI/NAP1/027) at supra-MICs (4× and 40×) and sub-MICs (0.5×) of surotomycin and comparators. Following treatment, CFU counts, toxin A and B concentrations, and cellular morphological changes using scanning electron microscopy were examined. Inflammatory response was determined by measuring interleukin-8 (IL-8) concentrations from polarized Caco-2 cells exposed to antibiotic-treatedC. difficilegrowth media. Supra-MICs (4× and 40×) of surotomycin resulted in a reduction of vegetative cells over 72 h (4-log difference,P< 0.01) compared to controls. These results correlated with decreases of 77% and 68% in toxin A and B production at 48 h, respectively (P< 0.005, each), which resulted in a significant reduction in IL-8 concentration compared to controls. Similar results were observed with comparator antibiotics. Bacterial cell morphology showed that the cell wall was broken apart by surotomycin treatment at supra-MICs while sub-MIC studies showed a “deflated” phenotype plus a rippling effect. These results suggest that surotomycin has potent killing effects onC. difficilethat results in reduced toxin production and attenuates the immune response similar to comparator antibiotics. The morphological data also confirm observations that surotomycin is a membrane-active antibiotic.

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Human impacts reduce morphological diversity in an insular species of lizard

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2017.0921 ◽

2017 ◽

Vol 284 (1857) ◽

pp. 20170921 ◽

Cited By ~ 5

Author(s):

Corentin Bochaton ◽

Salvador Bailon ◽

Anthony Herrel ◽

Sandrine Grouard ◽

Ivan Ineich ◽

...

Keyword(s):

Late Pleistocene ◽

Human Impacts ◽

Morphological Changes ◽

Morphological Evolution ◽

Morphological Diversity ◽

Apparent Size ◽

Climatic Transition ◽

Long Term Impact ◽

The Impact

Fossil remains provide useful insights into the long-term impact of anthropogenic phenomena on faunas and are often used to reveal the local (extirpations) or global (extinctions) losses of populations or species. However, other phenomena such as minor morphological changes can remain inconspicuous in the fossil record depending on the methodology used. In this study, we used the anole of Marie-Galante Island ( Anolis ferreus ) in Guadeloupe (French, West Indies) as a model to demonstrate how the morphological evolution of an insular lizard can be tracked through the Pleistocene/Holocene climatic transition and the recent anthropization of the island. We used a fossil assemblage of nearly 30 000 remains and a combination of anatomical description, traditional morphometry and geometric morphometrics. These fossils are attributed to a single taxon, most likely to be A. ferreus on the basis of morphological and morphometric arguments. Our results show the disappearance of a distinct (sub)population of large specimens that were about 25% larger than the modern representatives of A. ferreus . We also demonstrate an apparent size stability of the main fossil population of this species since the Late Pleistocene but with the possible occurrence of a reduction in morphological diversity during the Late Holocene. These results highlight the impact of anthropic disturbances on a lizard whose morphology otherwise remained stable since the Late Pleistocene.

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The impact of environmental enrichment on the murine inflammatory immune response

JCI Insight ◽

10.1172/jci.insight.90723 ◽

2017 ◽

Vol 2 (7) ◽

Cited By ~ 8

Author(s):

Samuel Brod ◽

Thomas Gobbetti ◽

Beatrice Gittens ◽

Masahiro Ono ◽

Mauro Perretti ◽

...

Keyword(s):

Immune Response ◽

Environmental Enrichment ◽

Inflammatory Immune Response ◽

The Impact

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Limbic Encephalitis Brain Damage Induced by Cocal Virus in Adult Mice Is Reduced by Environmental Enrichment: Neuropathological and Behavioral Studies

Viruses ◽

10.3390/v13010048 ◽

2020 ◽

Vol 13 (1) ◽

pp. 48

Author(s):

Priscilla dos Santos Lieuthier Freitas ◽

Ana Victória de Lima Lima ◽

Karina Glazianne Barbosa Carvalho ◽

Tatyane da Silva Cabral ◽

Alexandre Maia de Farias ◽

...

Keyword(s):

Disease Progression ◽

Environmental Enrichment ◽

Limbic Encephalitis ◽

Morphological Changes ◽

Experimental Models ◽

Behavioral Changes ◽

Cytokine Concentration ◽

Morphological Response ◽

Viral Antigens ◽

Adult Mice

We previously demonstrated, using the Piry virus model, that environmental enrichment promotes higher T-cell infiltration, fewer microglial changes, and faster central nervous system (CNS) virus clearance in adult mice. However, little is known about disease progression, behavioral changes, CNS cytokine concentration, and neuropathology in limbic encephalitis in experimental models. Using Cocal virus, we infected C57Bl6 adult mice and studied the neuroanatomical distribution of viral antigens in correlation with the microglial morphological response, measured the CNS cytokine concentration, and assessed behavioral changes. C57Bl6 adult mice were maintained in an impoverished environment (IE) or enriched environment (EE) for four months and then subjected to the open field test. Afterwards, an equal volume of normal or virus-infected brain homogenate was nasally instilled. The brains were processed to detect viral antigens and microglial morphological changes using selective immunolabeling. We demonstrated earlier significant weight loss and higher mortality in IE mice. Additionally, behavioral analysis revealed a significant influence of the environment on locomotor and exploratory activity that was associated with less neuroinvasion and a reduced microglial response. Thus, environmental enrichment was associated with a more effective immune response in a mouse model of limbic encephalitis, allowing faster viral clearance/decreased viral dissemination, reduced disease progression, and less CNS damage.

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Comparative assessment of morphological mechanisms of maintaining structural liver homeostasis in the dynamics of exposure to coal-rock dust and sodium fluoride on the body

Russian Journal of Occupational Health and Industrial Ecology ◽

10.31089/1026-9428-2020-60-3-189-194 ◽

2020 ◽

pp. 189-194

Author(s):

M. S. Bugaeva ◽

O. I. Bondarev ◽

N. N. Mikhailova ◽

L. G. Gorokhova

Keyword(s):

Sodium Fluoride ◽

Morphological Changes ◽

The Body ◽

System Level ◽

Production Factor ◽

Coal Rock ◽

The Impact ◽

Structural Homeostasis ◽

Rock Dust

Introduction. The impact on the body of such factors of the production environment as coal-rock dust and fluorine compounds leads to certain shift s in strict indicators of homeostasis at the system level. Maintaining the relative constancy of the internal environment of the body is provided by the functional consistency of all organs and systems, the leading of which is the liver. Organ repair plays a crucial role in restoring the structure of genetic material and maintaining normal cell viability. When this mechanism is damaged, the compensatory capabilities of the organ are disrupted, homeostasis is disrupted at the cellular and organizational levels, and the development of the main pathological processes is noted.The aim of the study is to compare the morphological mechanisms of maintaining structural homeostasis of the liver in the dynamics of the impact on the body of coal-rock dust and sodium fluoride.Materials and methods. Experimental studies were conducted on adult white male laboratory rats. Features of morphological mechanisms for maintaining structural homeostasis of the liver in the dynamics of exposure to coal-rock dust and sodium fluoride were studied on experimental models of pneumoconiosis and fluoride intoxication. For histological examination in experimental animals, liver sampling was performed after 1, 3, 6, 9, 12 weeks of the experiment.Results. The specificity of morphological changes in the liver depending on the harmful production factor was revealed. It is shown that chronic exposure to coal-rock dust and sodium fluoride is characterized by the development of similar morphological changes in the liver and its vessels from the predominance of the initial compensatory-adaptive to pronounced violations of the stromal and parenchymal components. Long-term inhalation of coal-rock dust at 1–3 weeks of seeding triggers adaptive mechanisms in the liver in the form of increased functional activity of cells, formation of double-core hepatocytes, activation of immunocompetent cells and endotheliocytes, ensuring the preservation of the parenchyma and the general morphostructure of the organ until the 12th week of the experiment. Exposure to sodium fluoride leads to early disruption of liver compensatory mechanisms and the development of dystrophic changes in the parenchyma with the formation of necrosis foci as early as the 6th week of the experiment.Conclusions. The study of mechanisms for compensating the liver structure in conditions of long-term exposure to coal-rock dust and sodium fluoride, as well as processes that indicate their failure, and the timing of their occurrence, is of theoretical and practical importance for developing recommendations for the timely prevention and correction of pathological conditions developing in employees of the aluminum and coal industry.The authors declare no conflict of interests.

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Methionine Diet Evoked Hyperhomocysteinemia Causes Hippocampal Alterations, Metabolomics Plasma Changes and Behavioral Pattern in Wild Type Rats

International Journal of Molecular Sciences ◽

10.3390/ijms22094961 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4961

Author(s):

Maria Kovalska ◽

Eva Baranovicova ◽

Dagmar Kalenska ◽

Anna Tomascova ◽

Marian Adamkov ◽

...

Keyword(s):

Morphological Changes ◽

Brain Area ◽

Critical Role ◽

Cerebrovascular Diseases ◽

Behavioral Pattern ◽

Cell Physiology ◽

Male Wistar Rats ◽

High Level ◽

Hippocampal Alterations ◽

The Impact

L-methionine, an essential amino acid, plays a critical role in cell physiology. High intake and/or dysregulation in methionine (Met) metabolism results in accumulation of its intermediate(s) or breakdown products in plasma, including homocysteine (Hcy). High level of Hcy in plasma, hyperhomocysteinemia (hHcy), is considered to be an independent risk factor for cerebrovascular diseases, stroke and dementias. To evoke a mild hHcy in adult male Wistar rats we used an enriched Met diet at a dose of 2 g/kg of animal weight/day in duration of 4 weeks. The study contributes to the exploration of the impact of Met enriched diet inducing mild hHcy on nervous tissue by detecting the histo-morphological, metabolomic and behavioural alterations. We found an altered plasma metabolomic profile, modified spatial and learning memory acquisition as well as remarkable histo-morphological changes such as a decrease in neurons’ vitality, alterations in the morphology of neurons in the selective vulnerable hippocampal CA 1 area of animals treated with Met enriched diet. Results of these approaches suggest that the mild hHcy alters plasma metabolome and behavioural and histo-morphological patterns in rats, likely due to the potential Met induced changes in “methylation index” of hippocampal brain area, which eventually aggravates the noxious effect of high methionine intake.

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Decitabine Promotes Modulation in Phenotype and Function of Monocytes and Macrophages That Drive Immune Response Regulation

Cells ◽

10.3390/cells10040868 ◽

2021 ◽

Vol 10 (4) ◽

pp. 868

Author(s):

Fabiana Albani Zambuzi ◽

Priscilla Mariane Cardoso-Silva ◽

Ricardo Cardoso Castro ◽

Caroline Fontanari ◽

Flavio da Silva Emery ◽

...

Keyword(s):

Immune Response ◽

Hematological Malignancies ◽

M2 Macrophage ◽

M2 Polarization ◽

Tnf Α ◽

Monocytes And Macrophages ◽

Ifn Γ ◽

And Function ◽

The Impact

Decitabine is an approved hypomethylating agent used for treating hematological malignancies. Although decitabine targets altered cells, epidrugs can trigger immunomodulatory effects, reinforcing the hypothesis of immunoregulation in treated patients. We therefore aimed to evaluate the impact of decitabine treatment on the phenotype and functions of monocytes and macrophages, which are pivotal cells of the innate immunity system. In vitro decitabine administration increased bacterial phagocytosis and IL-8 release, but impaired microbicidal activity of monocytes. In addition, during monocyte-to-macrophage differentiation, treatment promoted the M2-like profile, with increased expression of CD206 and ALOX15. Macrophages also demonstrated reduced infection control when exposed to Mycobacterium tuberculosis in vitro. However, cytokine production remained unchanged, indicating an atypical M2 macrophage. Furthermore, when macrophages were cocultured with lymphocytes, decitabine induced a reduction in the release of inflammatory cytokines such as IL-1β, TNF-α, and IFN-γ, maintaining IL-10 production, suggesting that decitabine could potentialize M2 polarization and might be considered as a therapeutic against the exacerbated immune response.

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NLRP7 Promotes Choriocarcinoma Growth and Progression through the Establishment of an Immunosuppressive Microenvironment

Cancers ◽

10.3390/cancers13122999 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2999

Author(s):

Deborah Reynaud ◽

Roland Abi Nahed ◽

Nicolas Lemaitre ◽

Pierre-Adrien Bolze ◽

Wael Traboulsi ◽

...

Keyword(s):

Immune Response ◽

Tumor Cells ◽

Major Gene ◽

Critical Role ◽

Orthotopic Model ◽

Independent Manner ◽

Maternal Immune Response ◽

The Impact

The inflammatory gene NLRP7 is the major gene responsible for recurrent complete hydatidiform moles (CHM), an abnormal pregnancy that can develop into gestational choriocarcinoma (CC). However, the role of NLRP7 in the development and immune tolerance of CC has not been investigated. Three approaches were employed to define the role of NLRP7 in CC development: (i) a clinical study that analyzed human placenta and sera collected from women with normal pregnancies, CHM or CC; (ii) an in vitro study that investigated the impact of NLRP7 knockdown on tumor growth and organization; and (iii) an in vivo study that used two CC mouse models, including an orthotopic model. NLRP7 and circulating inflammatory cytokines were upregulated in tumor cells and in CHM and CC. In tumor cells, NLRP7 functions in an inflammasome-independent manner and promoted their proliferation and 3D organization. Gravid mice placentas injected with CC cells invalidated for NLRP7, exhibited higher maternal immune response, developed smaller tumors, and displayed less metastases. Our data characterized the critical role of NLRP7 in CC and provided evidence of its contribution to the development of an immunosuppressive maternal microenvironment that not only downregulates the maternal immune response but also fosters the growth and progression of CC.

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Smo-Shh signaling activator purmorphamine ameliorates neurobehavioral, molecular, and morphological alterations in an intracerebroventricular propionic acid-induced experimental model of autism

Human & Experimental Toxicology ◽

10.1177/09603271211013456 ◽

2021 ◽

pp. 096032712110134

Author(s):

S Rahi ◽

R Gupta ◽

A Sharma ◽

S Mehan

Keyword(s):

Propionic Acid ◽

Developmental Process ◽

Morphological Changes ◽

Neuronal Cell Death ◽

Neuronal Cell ◽

Autism Spectrum ◽

Neurodevelopmental Disease ◽

Shh Pathway ◽

Apoptotic Markers ◽

The Impact

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disease characterized by cognitive and sensorimotor impairment. Numerous research findings have consistently shown that alteration of Smo-Shh (smoothened-sonic hedgehog) signaling during the developmental process plays a significant role in ASD and triggers neuronal changes by promoting neuroinflammation and apoptotic markers. Purmorphamine (PUR), a small purine-derived agonist of the Smo-Shh pathway, shows resistance to hippocampal neuronal cell oxidation and decreases neuronal cell death. The goal of this study was to investigate the neuroprotective potential of PUR in brain intoxication induced by intracerebroventricular-propionic acid (ICV-PPA) in rats, with a focus on its effect on Smo-Shh regulation in the brain of rats. In addition, we analyze the impact of PUR on myelin basic protein (MBP) and apoptotic markers such as Caspase-3, Bax (pro-apoptotic), and Bcl-2 (anti-apoptotic) in rat brain homogenates. Chronic ICV-PPA infusion was administered consecutively for 11 days to induce autism in rats. In order to investigate behavioral alterations, rats were tested for spatial learning in the Morris Water Maze (MWM), locomotive alterations using actophotometer, and beam crossing task, while Forced Swimming Test (FST) for depressive behavior. PUR treatment with 5 mg/kg and 10 mg/kg (i.p.) was administered from day 12 to 44. Besides cellular, molecular and neuroinflammatory analyses, neurotransmitter levels and oxidative markers have also been studied in brain homogenates. The results of this study have shown that PUR increases the level of Smo-Shh and restores the neurochemical levels, and potentially prevents morphological changes, including demyelination.

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Ellagitannins, Gallotannins and their Metabolites- The Contribution to the Anti-Inflammatory Effect of Food Products and Medicinal Plants

Current Medicinal Chemistry ◽

10.2174/0929867323666160919111559 ◽

2019 ◽

Vol 25 (37) ◽

pp. 4946-4967 ◽

Cited By ~ 18

Author(s):

Anna K. Kiss ◽

Jakub P. Piwowarski

Keyword(s):

Immune Response ◽

Gastrointestinal Tract ◽

Gut Microbiota ◽

Health Effects ◽

Biological Effects ◽

Food Products ◽

Anti Inflammatory ◽

The Impact

The popularity of food products and medicinal plant materials containing hydrolysable tannins (HT) is nowadays rapidly increasing. Among various health effects attributable to the products of plant origin rich in gallotannins and/or ellagitannins the most often underlined is the beneficial influence on diseases possessing inflammatory background. Results of clinical, interventional and animal in vivo studies clearly indicate the antiinflammatory potential of HT-containing products, as well as pure ellagitannins and gallotannins. In recent years a great emphasis has been put on the consideration of metabolism and bioavailability of natural products during examination of their biological effects. Conducted in vivo and in vitro studies of polyphenols metabolism put a new light on this issue and indicate the gut microbiota to play a crucial role in the health effects following their oral administration. The aim of the review is to summarize the knowledge about HT-containing products’ phytochemistry and their anti-inflammatory effects together with discussion of the data about observed biological activities with regards to the current concepts on the HTs’ bioavailability and metabolism. Orally administered HT-containing products due to the limited bioavailability of ellagitannins and gallotannins can influence immune response at the level of gastrointestinal tract as well as express modulating effects on the gut microbiota composition. However, due to the chemical changes being a result of their transit through gastrointestinal tract, comprising of hydrolysis and gut microbiota metabolism, the activity of produced metabolites has to be taken into consideration. Studies regarding biological effects of the HTs’ metabolites, in particular urolithins, indicate their strong and structure-dependent anti-inflammatory activities, being observed at the concentrations, which fit the range of their established bioavailability. The impact of HTs on inflammatory processes has been well established on various in vivo and in vitro models, while influence of microbiota metabolites on silencing the immune response gives a new perspective on understanding anti-inflammatory effects attributed to HT containing products, especially their postulated effectiveness in inflammatory bowel diseases (IBD) and cardiovascular diseases.

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