The secretome of M1 and M2 microglia differently regulate proliferation, differentiation and survival of adult neural stem/progenitor cell

Microglia has been reported to be able to regulate the proliferation, differentiation and survival of adult Neural stem/progenitor cells (NSPCs) by modulating the microenvironment, which results in different consequences of adult neurogenesis. However, whether the microglial activation is beneficial or harmful to NSPCs is still controversial because of the complexity and variability of microglial activation phenotypes. In this study, we detected the expression levels of M1 marker and M2 marker in IFN-γ- and IL-4-induced microglia at different time, respectively. The phenotypic markers of M1 and M2 microglia were stable for 24 h after removal of IFN-γ and IL-4 intervention, but exhibited different change patterns during the next 24 h. Then, the adult NSPCs were treated by the conditioned medium from IFN-γ- and IL-4-activated microglia. The conditioned medium from IFN-γ-activated microglia promoted apoptosis and astroglial differentiation of NSPCs, while suppressed proliferation and neuronal differentiation of NSPCs. However, the conditioned medium from IL-4-activated microglia exhibited opposite effects on these physiological processes. In addition, the direct treatment of IFN-γ or IL-4 alone did not significantly affect the proliferation, differentiation and survival of NSPCs. These results suggest that the secretome of pro-inflammatory (M1) and anti-inflammatory (M2) microglia differently regulated the proliferation, differentiation and survival of adult NSPCs. These findings will help further study the biological mechanism of microglia regulating neurogenesis, and provide a therapeutic strategy for neurological diseases by regulating microglial phenotypes to affect neurogenesis.

Download Full-text

Heterogeneity of Microglia Phenotypes: Developmental, Functional and Some Therapeutic Considerations

Current Pharmaceutical Design ◽

10.2174/1381612825666190722114248 ◽

2019 ◽

Vol 25 (21) ◽

pp. 2375-2393 ◽

Cited By ~ 5

Author(s):

Yun Yuan ◽

Chunyun Wu ◽

Eng-Ang Ling

Keyword(s):

Brain Lesion ◽

Translocator Protein ◽

Trophic Factors ◽

Microglial Cells ◽

Brain Maturation ◽

Activated Microglia ◽

Proinflammatory Mediators ◽

Pathological Conditions ◽

Positron Emission ◽

M2 Microglia

Background: Microglia play a pivotal role in maintaining homeostasis in complex brain environment. They first exist as amoeboid microglial cells (AMCs) in the developing brain, but with brain maturation, they transform into ramified microglial cells (RMCs). In pathological conditions, microglia are activated and have been classified into M1 and M2 phenotypes. The roles of AMCs, RMCs and M1/M2 microglia phenotypes especially in pathological conditions have been the focus of many recent studies. Methods: Here, we review the early development of the AMCs and RMCs and discuss their specific functions with reference to their anatomic locations, immunochemical coding etc. M1 and M2 microglia phenotypes in different neuropathological conditions are also reviewed. Results: Activated microglia are engaged in phagocytosis, production of proinflammatory mediators, trophic factors and synaptogenesis etc. Prolonged microglia activation, however, can cause damage to neurons and oligodendrocytes. The M1 and M2 phenotypes featured prominently in pathological conditions are discussed in depth. Experimental evidence suggests that microglia phenotype is being modulated by multiple factors including external and internal stimuli, local demands, epigenetic regulation, and herbal compounds. Conclusion: Prevailing views converge that M2 polarization is neuroprotective. Thus, proper therapeutic designs including the use of anti-inflammatory drugs, herbal agents may be beneficial in suppression of microglial activation, especially M1 phenotype, for amelioration of neuroinflammation in different neuropathological conditions. Finally, recent development of radioligands targeting 18 kDa translocator protein (TSPO) in activated microglia may hold great promises clinically for early detection of brain lesion with the positron emission tomography.

Download Full-text

Tailored Hydrogels as Delivery Platforms for Conditioned Medium from Mesenchymal Stem Cells in a Model of Acute Colitis in Mice

Pharmaceutics ◽

10.3390/pharmaceutics13081127 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1127

Author(s):

Juan Sendon-Lago ◽

Lorena Garcia-del Rio ◽

Noemi Eiro ◽

Patricia Diaz-Rodriguez ◽

Leandro Avila ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Body Weight ◽

Conditioned Medium ◽

Local Treatment ◽

Histopathological Analysis ◽

Mrna Levels ◽

Acute Colitis ◽

Tnf Α ◽

Ifn Γ

Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), is increasingly prevalent and current therapies are not completely effective. Mesenchymal stem cells are emerging as a promising therapeutic option. Here, the effect of local hydrogel application loaded with conditioned medium (CM) from human uterine cervical stem cells (hUCESC-CM) in an experimental acute colitis mice model has been evaluated. Colitis induction was carried out in C57BL/6 mice by dissolving dextran sulfate sodium (DSS) in drinking water for nine days. Ulcers were treated by rectal administration of either mesalazine (as positive control) or a mucoadhesive and thermosensitive hydrogel loaded with hUCESC-CM (H-hUCESC-CM). Body weight changes, colon length, and histopathological analysis were evaluated. In addition, pro-inflammatory TNF-α, IL-6, and IFN-γ mRNA levels were measured by qPCR. Treatment with H-hUCESC-CM inhibited body weight loss and colon shortening and induced a significant decrease in colon mucosa degeneration, as well as TNF-α, IFN-γ, and IL-6 mRNA levels. Results indicate that H-hUCESC-CM effectively alleviated DSS-induced colitis in mice, suggesting that H-hUCESC-CM may represent an attractive cell-free therapy for local treatment of IBD.

Download Full-text

Abstract W P222: Activated Microglia Contribute to Neurovascular Integrity and Limit Brain Injury After Acute Neonatal Focal Stroke

Stroke ◽

10.1161/str.45.suppl_1.wp222 ◽

2014 ◽

Vol 45 (suppl_1) ◽

Author(s):

David Fernández-López ◽

Joel Faustino ◽

Alexander Klibanov ◽

Nikita Derugin ◽

katerina Akassoglou ◽

...

Keyword(s):

Brain Injury ◽

Microglial Activation ◽

Injury Severity ◽

Infarct Volume ◽

Artery Occlusion ◽

Microglial Cells ◽

Vascular Density ◽

Relative Role ◽

Morphological Transformation ◽

Activated Microglia

It has been recently shown that microglial cells, which for a long time were considered purely injurious in the context of cerebral ischemia, can also exert beneficial effects following stroke in both adults and neonates1,2. Lack of tools to reliably distinguish resident microglia from infiltrated peripheral monocytes has been a major obstacle on the way to understand the relative role of these subpopulations of cells of the monocyte lineage in the pathophysiology of stroke. We subjected postnatal day 10 (P10) transgenic Cx3cr1GFP/-CCr2RFP/- mice, in which resident microglia (Cx3cr1GFP) and infiltrating monocytes (CCr2RFP) can be distinctively identified, to a transient 3 hour middle cerebral artery occlusion MCAO, a model that we recently developed3. Microglial cells were left unperturbed or were selectively depleted before MCAO by intracortical injection of clodronate-encapsulated liposomes. Depletion of microglia exacerbated injury and significantly increased infarct volume (75.9% Vs. 56.3%, p<0.01). Furthermore, compared to mice with unperturbed microglia, depletion of microglia significantly increased the number of hemorrhages in injured regions, adversely affected vascular density and decreased the number of both adherent and infiltrated monocytes. The extent of RFP+ monocyte adhesion to vessels and infiltration in the brain parenchyma was highly variable among individual mice and did not correlate with brain infarct, whereas a significant correlation between the overall extent of microglial activation (measured by morphological transformation) and the number of infiltrated monocytes was observed. The deleterious effect of microglial depletion on vascular integrity and function and on brain injury indicates that activated microglia act as a buffering component that limits vascular degeneration and injury severity after neonatal stroke. Our data also suggest a direct and dynamic relationship between microglial activation and monocyte recruitment into acutely reperfused neonatal brain. Support: NS55915 (ZV), NS76726 (ZV), NS080015 (ZS, KA), AHA POST10980003 (DFL). 1. Faustino J et al. J Neurosci. 2011. 2. Lalancette-Hebert M et al. J Neurosci. 2007. 3. Woo MS et al. Annals of Neurology. 2012.

Download Full-text

Pre-therapeutic Microglia Activation and Sex Determine Therapy Effects of Chronic Immunomodulation

10.1101/2021.05.30.445761 ◽

2021 ◽

Author(s):

Gloria Biechele ◽

Tanja Blume ◽

Maximilian Deussing ◽

Benedikt Zott ◽

Yuan Shi ◽

...

Keyword(s):

Spatial Learning ◽

Microglial Activation ◽

Translocator Protein ◽

Learning Performance ◽

Peroxisome Proliferator ◽

Peroxisome Proliferator Activated Receptor ◽

Activated Microglia ◽

Ppar Γ ◽

Amyloid Accumulation ◽

Β Amyloid

Modulation of the innate immune system is emerging as a promising therapeutic strategy against Alzheimer's disease (AD). However, determinants of a beneficial therapeutic effect are ill-understood. Thus, we investigated the potential of 18 kDa translocator protein positron-emission-tomography (TSPO-PET) for assessment of microglial activation in mouse brain before and during chronic immunomodulation. Serial TSPO-PET was performed during five months of chronic microglia modulation by stimulation of peroxisome proliferator-activated receptor (PPAR)-γ with pioglitazone in two different mouse models of AD (PS2APP, AppNL-G-F). Using mixed statistical models on longitudinal TSPO-PET data, we tested for effects of therapy and sex on treatment response. We tested correlations of baseline with longitudinal measures of TSPO-PET, and correlations between PET results with spatial learning performance and β-amyloid accumulation of individual mice. Immunohistochemistry was used to determine the molecular source of the TSPO-PET signal. Pioglitazone-treated female PS2APP and AppNL-G-F mice showed attenuation of the longitudinal increases in TSPO-PET signal when compared to vehicle controls, whereas treated male AppNL-G-F mice showed the opposite effect. Baseline TSPO-PET strongly predicted changes in microglial activation in treated mice (R=-0.874, p<0.0001) but not in vehicle controls (R=-0.356, p=0.081). Reduced TSPO-PET signal upon treatment was associated with better spatial learning and higher fibrillar β-amyloid accumulation. Immunohistochemistry confirmed activated microglia to be the source of the TSPO-PET signal (R=0.952, p<0.0001). TSPO-PET represents a sensitive biomarker for monitoring of immunomodulation and closely reflects activated microglia. Pre-therapeutic assessment of baseline microglial activation and sex are strong predictors of individual immunomodulation effects and could serve for responder stratification.

Download Full-text

Inhibited CSF1R Alleviates Ischemia Injury via Inhibition of Microglia M1 Polarization and NLRP3 Pathway

Neural Plasticity ◽

10.1155/2020/8825954 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11 ◽

Cited By ~ 3

Author(s):

Xiaoxue Du ◽

Yuzhen Xu ◽

Shijia Chen ◽

Marong Fang

Keyword(s):

Treatment Group ◽

Neurological Diseases ◽

Cerebral Stroke ◽

Mice Model ◽

Neuron Death ◽

Triphenyltetrazolium Chloride ◽

Neurobehavioral Function ◽

M2 Microglia ◽

M1 Polarization ◽

Rota Rod Test

Ischemia cerebral stroke is one of the common neurological diseases with severe inflammatory response and neuron death. The inhibition of colony-stimulating factor 1 receptor (CSF1R) which especially expressed in microglia/macrophage exerted neuroprotection in stroke. However, the underlying neuroinflammatory regulation effects of CSF1R in ischemia stroke are not clear. In this study, cerebral ischemia stroke mice model was established. The C57/B6J mice were administered with Ki20227, a CSF1R inhibitor, by gavage for 7 consecutive days (0.002 mg/kg/day) before modeling. The Rota-Rod test and neurobehavioral score test were investigated to assess neurobehavioral functions. The area of infarction was assessed by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. The mRNA expressions of M1/M2 microglia markers were evaluated by real-time PCR. Immunofluorescence and Western blot were utilized to detect the changes of Iba1 and NLRP3 pathway proteins. Results showed that neurobehavioral function improvement was demonstrated by an increased stay time on the Rota-Rod test and a decreased neurobehavioral score in the Ki20227 treatment group. The area of infarction reduced in Ki20227 group when compared to the stroke group. Moreover, the mRNA expression of M1 microglia markers (TNF-α and iNOS) decreased while M2 microglia markers (IL-10 and Arg-1) increased. Meanwhile, compared to the stroke and stroke+PBS group, Ki20227 administration downregulated the expression of NLRP3, active caspase 1, and NF-κB protein in the ischemia penumbra of Ki20227 treatment group mice. In short, the CSF1R inhibitor, Ki20227, played vital neuroprotective roles in ischemia cerebral stroke mice, and the mechanisms may be via inhibiting microglia M1 polarization and NLRP3 inflammasome pathway activation. Our study provides a potential new target for the treatment of ischemic stroke injury.

Download Full-text

Protective Effects of Melatonin on Neurogenesis Impairment in Neurological Disorders and Its Relevant Molecular Mechanisms

International Journal of Molecular Sciences ◽

10.3390/ijms21165645 ◽

2020 ◽

Vol 21 (16) ◽

pp. 5645

Author(s):

Joseph Wai-Hin Leung ◽

Kwok-Kuen Cheung ◽

Shirley Pui-Ching Ngai ◽

Hector Wing-Hong Tsang ◽

Benson Wui-Man Lau

Keyword(s):

Therapeutic Strategy ◽

Molecular Mechanisms ◽

Neural Progenitor Cells ◽

Neurological Diseases ◽

Protective Effects ◽

Neurological Outcomes ◽

Pathological Conditions ◽

Neurological Illnesses ◽

Neurological Conditions ◽

Traditional Understanding

Neurogenesis is the process by which functional new neurons are generated from the neural stem cells (NSCs) or neural progenitor cells (NPCs). Increasing lines of evidence show that neurogenesis impairment is involved in different neurological illnesses, including mood disorders, neurogenerative diseases, and central nervous system (CNS) injuries. Since reversing neurogenesis impairment was found to improve neurological outcomes in the pathological conditions, it is speculated that modulating neurogenesis is a potential therapeutic strategy for neurological diseases. Among different modulators of neurogenesis, melatonin is a particularly interesting one. In traditional understanding, melatonin controls the circadian rhythm and sleep–wake cycle, although it is not directly involved in the proliferation and survival of neurons. In the last decade, it was reported that melatonin plays an important role in the regulation of neurogenesis, and thus it may be a potential treatment for neurogenesis-related disorders. The present review aims to summarize and discuss the recent findings regarding the protective effects of melatonin on the neurogenesis impairment in different neurological conditions. We also address the molecular mechanisms involved in the actions of melatonin in neurogenesis modulation.

Download Full-text

Prion Protein Expression Differences in Microglia and Astroglia Influence Scrapie-Induced Neurodegeneration in the Retina and Brain of Transgenic Mice

Journal of Virology ◽

10.1128/jvi.00865-07 ◽

2007 ◽

Vol 81 (19) ◽

pp. 10340-10351 ◽

Cited By ~ 31

Author(s):

Lisa Kercher ◽

Cynthia Favara ◽

James F. Striebel ◽

Rachel LaCasse ◽

Bruce Chesebro

Keyword(s):

Transgenic Mice ◽

Prion Protein ◽

Microglial Activation ◽

Prion Diseases ◽

Cell Types ◽

Mouse Strains ◽

Activation Markers ◽

Activated Microglia ◽

Morphological Criteria ◽

Scrapie Infection

ABSTRACT Activated microglia and astroglia are known to be involved in a variety of neurodegenerative diseases, including prion diseases. In the present experiments, we studied activation of astroglia and microglia after intraocular scrapie infection in transgenic mice expressing prion protein (PrP) in multiple cell types (tg7 mice) or in neurons only (tgNSE mice). In this model, scrapie infection and protease-resistant PrP deposition occurs in the retinas of both strains of mice, but retinal degeneration is observed only in tg7 mice. Our results showed that the retinas of tg7 and tgNSE mice both had astroglial activation with increased chemokine expression during the course of infection. However, only tg7 retinas exhibited strong microglial activation compared to tgNSE retinas, which showed little microglial activation by biochemical or morphological criteria. Therefore, microglial PrP expression might be required for scrapie-induced retinal microglial activation and damage. Furthermore, microglial activation preceded retinal neurodegeneration in tg7 mice, suggesting that activated microglia might contribute to the degenerative process, rather than being a response to the damage. Surprisingly, brain differed from retina in that an altered profile of microglial activation markers was upregulated, and the profiles in the two mouse strains were indistinguishable. Microglial activation in the brain was associated with severe brain vacuolation and neurodegeneration, leading to death. Thus, retinal and brain microglia appeared to differ in their requirements for activation, suggesting that different activation pathways occur in the two tissues.

Download Full-text

Angioblast Derived from ES Cells Construct Blood Vessels and Ameliorate Diabetic Polyneuropathy in Mice

Journal of Diabetes Research ◽

10.1155/2015/257230 ◽

2015 ◽

Vol 2015 ◽

pp. 1-17 ◽

Cited By ~ 8

Author(s):

Tatsuhito Himeno ◽

Hideki Kamiya ◽

Keiko Naruse ◽

Zhao Cheng ◽

Sachiko Ito ◽

...

Keyword(s):

Stem Cells ◽

Embryonic Stem Cells ◽

Blood Vessels ◽

Progenitor Cell ◽

Therapeutic Strategy ◽

Es Cells ◽

Embryonic Stem ◽

Diabetic Polyneuropathy ◽

Mouse Embryonic Stem Cells ◽

Intraepidermal Nerve Fiber

Background. Although numerous reports addressing pathological involvements of diabetic polyneuropathy have been conducted, a universally effective treatment of diabetic polyneuropathy has not yet been established. Recently, regenerative medicine studies in diabetic polyneuropathy using somatic stem/progenitor cell have been reported. However, the effectiveness of these cell transplantations was restricted because of their functional and numerical impairment in diabetic objects. Here, we investigated the efficacy of treatment for diabetic polyneuropathy using angioblast-like cells derived from mouse embryonic stem cells.Methods and Results. Angioblast-like cells were obtained from mouse embryonic stem cells and transplantation of these cells improved several physiological impairments in diabetic polyneuropathy: hypoalgesia, delayed nerve conduction velocities, and reduced blood flow in sciatic nerve and plantar skin. Furthermore, pathologically, the capillary number to muscle fiber ratios were increased in skeletal muscles of transplanted hindlimbs, and intraepidermal nerve fiber densities were ameliorated in transplanted plantar skin. Transplanted cells maintained their viabilities and differentiated to endothelial cells and smooth muscle cells around the injection sites. Moreover, several transplanted cells constructed chimeric blood vessels with recipient cells.Conclusions. These results suggest that transplantation of angioblast like cells induced from embryonic stem cells appears to be a novel therapeutic strategy for diabetic polyneuropathy.

Download Full-text

Conditioned Medium from Activated Microglia Promotes Cholinergic Differentiation in the Basal Forebrainin Vitro

Developmental Biology ◽

10.1006/dbio.1996.0147 ◽

1996 ◽

Vol 177 (1) ◽

pp. 85-95 ◽

Cited By ~ 35

Author(s):

G.Miller Jonakait ◽

Marla B. Luskin ◽

Rongtai Wei ◽

Xue-Feng Tian ◽

Li Ni

Keyword(s):

Conditioned Medium ◽

Activated Microglia

Download Full-text

Superantigen immune stimulation activates epithelial STAT-1 and PI 3-K: PI 3-K regulation of permeability

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.2000.279.5.g1094 ◽

2000 ◽

Vol 279 (5) ◽

pp. G1094-G1103 ◽

Cited By ~ 16

Author(s):

Derek M. McKay ◽

Fernando Botelho ◽

Peter J. M. Ceponis ◽

Carl D. Richards

Keyword(s):

Epithelial Cells ◽

Conditioned Medium ◽

Intracellular Signaling ◽

Mononuclear Cells ◽

Interferon Γ ◽

Transepithelial Resistance ◽

Mobility Shift ◽

Peripheral Blood Mononuclear ◽

Ussing Chambers ◽

Ifn Γ

Signal transducers and activators of transcription (STATs) are critical intracellular signaling molecules for many cytokines. We compared the ability of T84 epithelial cells to activate STATs in response to cytokines [interferon-γ (IFN-γ), interleukin (IL)-4, IL-10, and tumor necrosis factor-α (10 ng/ml)] and conditioned medium from superantigen [ Staphylococcus aureus enterotoxin B (SEB)]-activated peripheral blood mononuclear cells (PBMC) using electrophoretic mobility shift assays (EMSA). Of the cytokines tested, only IFN-γ caused a STAT-1 response. Exposure to SEB-PBMC-conditioned medium resulted in STAT-1 or STAT-1/3 activation, and inclusion of anti-IFN-γ antibodies in the conditioned medium abolished the STAT-1 signal. Cells treated with transcription factor decoys, DNA oligonucleotides bearing the STAT-1 recognition motif, and then SEB-PBMC-conditioned medium displayed a reduced STAT-1 signal on EMSA, yet this treatment did not prevent the drop in transepithelial resistance (measured in Ussing chambers) caused by SEB-PBMC-conditioned medium. In contrast, the phosphatidylinositol 3′-kinase (PI 3-K) inhibitor LY-294002 significantly reduced the drop in transepithelial resistance caused by SEB-PBMC-conditioned medium. Thus data are presented showing STAT-1 (±STAT-3) and PI 3-K activation in epithelial cells in response to immune mediators released by superantigen immune activation. Although the involvement of STAT-1/-3 in the control of barrier function remains a possibility, PI-3K has been identified as a regulator of T84 paracellular permeability.

Download Full-text