scholarly journals Age-Dependent Changes in Regulatory T Lymphocyte Development and Function: A Mini-Review

Gerontology ◽  
2017 ◽  
Vol 64 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Julie Darrigues ◽  
Joost P.M. van Meerwijk ◽  
Paola Romagnoli
Keyword(s):  
T Lymphocyte ◽  
Tissue Repair ◽  
Dependent Manner ◽  
Peripheral Tissues ◽  
Regulatory T Lymphocytes ◽  
Age Dependent ◽  
And Function ◽  
Secondary Lymphoid Organs ◽  
Two Populations ◽  
Regulatory T Lymphocyte

The generation and function of immuno-suppressive regulatory T lymphocytes (Treg), which can differentiate in the thymus (tTreg) or in the periphery (pTreg), are regulated in an age-dependent manner. tTreg are produced at high levels in the first weeks of age, when they expand and colonize secondary lymphoid organs and peripheral tissues to protect the organism from autoimmune diseases and to promote tissue repair. Once this population of Treg is operational in the periphery, at puberty, thymic output of Treg declines, but self-reactive tTreg generated early on in life are maintained over time and play a major role in preserving homeostasis of the immune system. Extra-thymic pTreg differentiation declines later on in life. pTreg generated throughout life mainly protect the organism from chronic inflammation and the semi-allogeneic fetus from rejection. In this review, age-dependent modulation of the production and function of these two populations of Treg is described.

scholarly journals A LRRK2/dLRRK-mediated lysosomal pathway that contributes to glial cell death and DA neuron survival

2021 ◽  
Author(s):  
Linfang Wang ◽  
Honglei Wang ◽  
Margaret S Ho
Keyword(s):  
Caspase 3 ◽  
Kinase Activity ◽  
Dependent Manner ◽  
Dopaminergic Neurodegeneration ◽  
Age Dependent ◽  
Sporadic Parkinson’S Disease ◽  
Locomotor Deficits ◽  
And Function ◽  
Reduced Activity

Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of familial and sporadic Parkinson's disease (PD). A plethora of evidence has indicated a role for LRRK2 in endolysosomal trafficking in neurons, while LRRK2 function in glia, although highly expressed, remains largely unknown. Here we present evidence that LRRK2/dLRRK mediates a glial lysosomal pathway that contributes to the mechanism of PD. Independent of its kinase activity, glial LRRK2/dLRRK knockdown in the immortalized microglial cells or flies results in enlarged and swelling lysosomes fewer in number. These lysosomes are less mobile, wrongly acidified, and exhibit defective membrane permeability and reduced activity of the lysosome hydrolase cathespin B. In addition, microglial LRRK2 depletion causes increased Caspase 3 levels, leading to glial apoptosis, dopaminergic neurodegeneration, and locomotor deficits in an age-dependent manner. Taken together, these findings demonstrate a functional role of LRRK2/dLRRK in regulating the glial lysosomal pathway; deficits in lysosomal biogenesis and function linking to glial apoptosis potentially underlie the mechanism of DA neurodegeneration, contributing to the progression of PD.

scholarly journals The transcription factor EGR2 is indispensable for tissue-specific imprinting of alveolar macrophages in health and tissue repair

2021 ◽  
Author(s):  
Jack McCowan ◽  
Phoebe M Kirkwood ◽  
Frederic Fercoq ◽  
Wouter T'Jonck ◽  
Connar M Mawer ◽  
...  
Keyword(s):  
Alveolar Macrophages ◽  
Transforming Growth Factor Beta ◽  
Tissue Repair ◽  
Transforming Growth Factor ◽  
Immune Surveillance ◽  
Respiratory Pathogen ◽  
Dependent Manner ◽  
Tissue Specific ◽  
Ppar Γ ◽  
And Function

Alveolar macrophages are the most abundant macrophages in the healthy lung where they play key roles in homeostasis and immune surveillance against air-borne pathogens. Tissue-specific differentiation and survival of alveolar macrophages relies on niche-derived factors, such as colony stimulating factor 2 (CSF-2) and transforming growth factor beta (TGF-β). However, the nature of the downstream molecular pathways that regulate the identity and function of alveolar macrophages and their response to injury remains poorly understood. Here, we identify that the transcriptional factor EGR2 is an evolutionarily conserved feature of lung alveolar macrophages and show that cell-intrinsic EGR2 is indispensable for the tissue-specific identity of alveolar macrophages. Mechanistically, we show that EGR2 is driven by TGF-β and CSF-2 in a PPAR-γ-dependent manner to control alveolar macrophage differentiation. Functionally, EGR2 was dispensable for lipid handling, but crucial for the effective elimination of the respiratory pathogen Streptococcus pneumoniae. Finally, we show that EGR2 is required for repopulation of the alveolar niche following sterile, bleomycin-induced lung injury and demonstrate that EGR2-dependent, monocyte-derived alveolar macrophages are vital for effective tissue repair following injury. Collectively, we demonstrate that EGR2 is an indispensable component of the transcriptional network controlling the identity and function of alveolar macrophages in health and disease.

scholarly journals 5-HT7R/G12 Signaling Regulates Neuronal Morphology and Function in an Age-Dependent Manner

2012 ◽  
Vol 32 (9) ◽  
pp. 2915-2930 ◽  
Author(s):  
F. Kobe ◽  
D. Guseva ◽  
T. P. Jensen ◽  
A. Wirth ◽  
U. Renner ◽  
...  
Keyword(s):  
Neuronal Morphology ◽  
Dependent Manner ◽  
Age Dependent ◽  
And Function

scholarly journals Age-dependent dormant resident progenitors are stimulated by injury to regenerate Purkinje neurons

2018 ◽  
Author(s):  
N. Sumru Bayin ◽  
Alexandre Wojcinski ◽  
Aurelien Mourton ◽  
Hiromitsu Saito ◽  
Noboru Suzuki ◽  
...  
Keyword(s):  
Dependent Manner ◽  
New Paradigm ◽  
Perinatal Brain Injury ◽  
Cerebellar Function ◽  
Efficient Regeneration ◽  
Age Dependent ◽  
Cerebellum Development ◽  
And Function ◽  
The Brain ◽  
Normal Cerebellum

AbstractOutside of the neurogenic niches of the brain, postmitotic neurons have not been found to undergo efficient regeneration. Here we demonstrate that Purkinje cells (PCs), which are born at midgestation and are crucial for both development and function of cerebellar circuits, are rapidly and fully regenerated following their ablation at birth. New PCs are produced by a previously unidentified progenitor population and support normal cerebellum development. The number of PC progenitors and their regenerative capacity, however, diminish soon after birth, and consequently PCs are poorly replenished when ablated at postnatal day 5. Nevertheless, the PC-depleted cerebella reach a normal size by increasing cell size, but scaling of neuron types is disrupted and cerebellar function is impaired. Our findings thus provide a new paradigm in the field of neuron regeneration by identifying a unipotent neural progenitor that buffers against perinatal brain injury in a stage-dependent process.One sentence summaryInjury induces a dormant progenitor population present at birth to regenerate cerebellar neurons in a time-dependent manner.

scholarly journals Transcriptional Regulation of Differentiation and Functions of Effector T Regulatory Cells

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 939 ◽  
Author(s):  
Shin-ichi Koizumi ◽  
Hiroki Ishikawa
Keyword(s):  
Transcriptional Regulation ◽  
Immune Responses ◽  
T Regulatory Cells ◽  
Treg Cells ◽  
Regulatory Cells ◽  
Peripheral Tissues ◽  
Self Tolerance ◽  
And Function ◽  
And Control ◽  
Secondary Lymphoid Organs

Foxp3-expressing regulatory T (Treg) cells can suppress the activity of various types of immune cells and play key roles in the maintenance of self-tolerance and in the regulation of immune responses against pathogens and tumor cells. Treg cells consist of heterogeneous subsets that have distinct phenotypes and functions. Upon antigen stimulation, naïve-like thymus-derived Treg cells, which circulate in secondary lymphoid organs, can differentiate into effector Treg (eTreg) cells and migrate to and control immune homeostasis of peripheral tissues. eTreg cells are heterogeneous in terms of their ability to localize to specific tissues and suppress particular types of immune responses. Differentiation and function of diverse eTreg subsets are regulated by a variety of transcription factors that are activated by antigens and cytokines. In this article, we review the current understanding of the transcriptional regulation of differentiation and function of eTreg cells.

scholarly journals Repair cell first, then regenerate the tissues and organs

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiao-Bing Fu
Keyword(s):  
Tissue Repair ◽  
Cell Damage ◽  
Ischemia Reperfusion ◽  
Severe Trauma ◽  
Basic Unit ◽  
Basic Process ◽  
Tissue Repair And Regeneration ◽  
Healing Tissue ◽  
Organ Repair ◽  
And Function

AbstractWound healing, tissue repair and regenerative medicine are in great demand, and great achievements in these fields have been made. The traditional strategy of tissue repair and regeneration has focused on the level of tissues and organs directly; however, the basic process of repair at the cell level is often neglected. Because the cell is the basic unit of organism structure and function; cell damage is caused first by ischemia or ischemia-reperfusion after severe trauma and injury. Then, damage to tissues and organs occurs with massive cell damage, apoptosis and even cell death. Thus, how to achieve the aim of perfect repair and regeneration? The basic process of tissue or organ repair and regeneration should involve repair of cells first, then tissues and organs. In this manuscript, it is my consideration about how to repair the cell first, then regenerate the tissues and organs.

scholarly journals The Cross-Talk between Mesenchymal Stem Cells and Immune Cells in Tissue Repair and Regeneration

2021 ◽  
Vol 22 (5) ◽  
pp. 2472
Author(s):  
Carl Randall Harrell ◽  
Valentin Djonov ◽  
Vladislav Volarevic
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Immune Cells ◽  
Tissue Repair ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Multipotent Stem Cells ◽  
Tissue Repair And Regeneration ◽  
Almost All ◽  
And Function

Mesenchymal stem cells (MSCs) are self-renewable, rapidly proliferating, multipotent stem cells which reside in almost all post-natal tissues. MSCs possess potent immunoregulatory properties and, in juxtacrine and paracrine manner, modulate phenotype and function of all immune cells that participate in tissue repair and regeneration. Additionally, MSCs produce various pro-angiogenic factors and promote neo-vascularization in healing tissues, contributing to their enhanced repair and regeneration. In this review article, we summarized current knowledge about molecular mechanisms that regulate the crosstalk between MSCs and immune cells in tissue repair and regeneration.

Second-trimester maternal lipid profiles predict pregnancy complications in an age-dependent manner

2019 ◽  
Vol 299 (5) ◽  
pp. 1253-1260 ◽  
Author(s):  
Qi Wu ◽  
Lixia Zhang ◽  
Licong Huang ◽  
Yu Lei ◽  
Lin Chen ◽  
...  
Keyword(s):  
Pregnancy Complications ◽  
Lipid Profiles ◽  
Dependent Manner ◽  
Second Trimester ◽  
Age Dependent

Deletion of murine tau gene increases tau aggregation in a human mutant tau transgenic mouse model

2010 ◽  
Vol 38 (4) ◽  
pp. 1001-1005 ◽  
Author(s):  
Kunie Ando ◽  
Karelle Leroy ◽  
Céline Heraud ◽  
Anna Kabova ◽  
Zehra Yilmaz ◽  
...  
Keyword(s):  
Mouse Model ◽  
Transgenic Mouse ◽  
Double Mutant ◽  
Transgenic Mouse Model ◽  
Tau Proteins ◽  
Dependent Manner ◽  
Age Dependent ◽  
Ad Alzheimer’S Disease ◽  
Tau Aggregation ◽  
The Brain

We have reported previously a tau transgenic mouse model (Tg30tau) overexpressing human 4R1N double-mutant tau (P301S and G272V) and that develops AD (Alzheimer's disease)-like NFTs (neurofibrillary tangles) in an age-dependent manner. Since murine tau might interfere with the toxic effects of human mutant tau, we set out to analyse the phenotype of our Tg30tau model in the absence of endogenous murine tau with the aim to reproduce more faithfully a model of human tauopathy. By crossing the Tg30tau line with TauKO (tau-knockout) mice, we have obtained a new mouse line called Tg30×TauKO that expresses only exogenous human double-mutant 4R1N tau. Whereas Tg30×TauKO mice express fewer tau proteins compared with Tg30tau, they exhibit augmented sarkosyl-insoluble tau in the brain and an increased number of Gallyas-positive NFTs in the hippocampus. Taken together, exclusion of murine tau causes accelerated tau aggregation during aging of this mutant tau transgenic model.

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