scholarly journals Neuronal apoptosis drives remodeling states of microglia and shifts in survival pathway dependence

2022 ◽  
Author(s):  
Sarah Rose Anderson ◽  
Jacqueline M Roberts ◽  
Nate Ghena ◽  
Emmalyn Irvin ◽  
Joon Schwakopf ◽  
...  
Keyword(s):  
Gene Expression ◽  
Neuronal Apoptosis ◽  
Mouse Retina ◽  
Survival Pathway ◽  
Lipid Metabolism Gene ◽  
Complement Receptor 3 ◽  
And Shifts ◽  
Developmental Remodeling ◽  
Stimulating Factor ◽  
Developing Nervous System

Microglia serve critical remodeling roles that shape the developing nervous system, responding to the changing neural environment with phagocytosis or soluble factor secretion. Recent single-cell sequencing (scRNAseq) studies have revealed the context-dependent diversity in microglial properties and gene expression, but the cues promoting this diversity are not well defined. Here, we ask how interactions with apoptotic neurons shape microglial state, including lysosomal and lipid metabolism gene expression and independence from Colony-stimulating factor 1 receptor (CSF1R) for survival. Using early postnatal mouse retina, a CNS region undergoing significant developmental remodeling, we performed scRNAseq on microglia from mice that are wild-type, lack neuronal apoptosis (Bax KO), or are treated with CSF1R inhibitor (PLX3397). We find that interactions with apoptotic neurons drives multiple microglial remodeling states, subsets of which are resistant to CSF1R inhibition. We find that TAM receptor Mer and complement receptor 3 are required for clearance of apoptotic neurons, but that Mer does not drive expression of remodeling genes. We show TAM receptor Axl is negligible for phagocytosis or remodeling gene expression but is consequential for microglial survival in the absence of CSF1R signaling. Thus, interactions with apoptotic neurons shift microglia towards distinct remodeling states and through Axl, alters microglial dependence on survival pathway, CSF1R.

scholarly journals β-Glucan enhances complement-mediated hematopoietic recovery after bone marrow injury

Blood ◽  
2006 ◽  
Vol 107 (2) ◽  
pp. 835-840 ◽  
Author(s):  
Daniel E. Cramer ◽  
Daniel J. Allendorf ◽  
Jarek T. Baran ◽  
Richard Hansen ◽  
Jose Marroquin ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mouse Serum ◽  
Complement Receptor ◽  
Dependent Manner ◽  
Complement Receptor 3 ◽  
Total Body ◽  
Stimulating Factor ◽  
Sublethal Irradiation ◽  
Classic Pathway

AbstractMyelotoxic injury in the bone marrow (BM) as a consequence of total body irradiation (TBI) or granulocyte colony-stimulating factor (G-CSF) mobilization results in the deposition of iC3b on BM stroma (stroma-iC3b). In the present study, we have examined how stroma-iC3b interacts with hematopoietic progenitor cells (HPCs) and the role of complement (C) and complement receptor 3 (CR3) in BM injury/repair. We demonstrate here that stroma-iC3b tethers HPCs via the inserted (I) domain of HPC complement receptor 3 (CR3, CD11b/CD18, Mac-1). Following irradiation, stroma-iC3b was observed in the presence of purified IgM and normal mouse serum (NMS), but not serum from Rag-2-/- mice, implicating a role for antibody (Ab) and the classic pathway of C activation. Furthermore, a novel role for soluble yeast β-glucan, a ligand for the CR3 lectin-like domain (LLD), in the priming of CR3+ HPC is suggested. Soluble yeast β-glucan could enhance the proliferation of tethered HPCs, promote leukocyte recovery following sublethal irradiation, and increase the survival of lethally irradiated animals following allogeneic HPC transplantation in a CR3-dependent manner. Taken together, these observations suggest a novel role for C, CR3, and β-glucan in the restoration of hematopoiesis following injury. (Blood. 2006;107:835-840)

Transduction of mouse retina by insect cell packaged recombinant adeno-associated virusess and their mutants via intravitreal injection

2021 ◽  
Author(s):  
Zheng Wei ◽  
Xiaomei Liu ◽  
Taiming Li ◽  
Xiaofang Li ◽  
Qungang Zhou ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Gene Expression Profiles ◽  
Mouse Retina ◽  
Transduction Efficiency ◽  
Egfp Expression ◽  
Wild Type ◽  
Gene Therapy Vector

Aim: Adeno-associated virus (AAV) is the most preferred gene therapy vector. The purpose of our research is to compare the infection tropism and gene expression efficiency of vitreous injection of recombinant AAVs (rAAVs) and their capsid mutants in mouse retina. Materials & methods: We packaged wild-type rAAV2/2,6,8,9 and their capsid mutants carrying EGFP expression cassette using insect cells. The gene expression profiles of rAAVs and their mutants in mouse retina were evaluated by optical imaging of retinal tissue flat mount and cryosections. Results & conclusion: The results showed that rAAV2 and rAAV2-Y444F mainly targeted retinal ganglion cell; rAAV8, rAAV8-Y733F, rAAV9 and mutants had obvious EGFP expression in retinal pigment epithelium cells. Compared with the wild-type rAAVs, capsid mutants have an improved transduction efficiency in mouse retina cells.

scholarly journals The Environmental Light Influences the Circulatory Levels of Retinoic Acid and Associates with Hepatic Lipid Metabolism

Endocrinology ◽  
2008 ◽  
Vol 149 (12) ◽  
pp. 6336-6342 ◽  
Author(s):  
Wenqiang Pang ◽  
Chunying Li ◽  
Yue Zhao ◽  
Shiming Wang ◽  
Wei Dong ◽  
...  
Keyword(s):  
Gene Expression ◽  
Retinoic Acid ◽  
Adenosine Receptors ◽  
Light Exposure ◽  
Retinoic Acid Receptor ◽  
Hepatic Lipase ◽  
Mouse Retina ◽  
Acid Receptor ◽  
Hepatic Lipid ◽  
Environmental Light

Environmental light is involved in the regulation of photochemical reaction in mouse retina. It remains unclear whether light-mediated increase in all-trans retinoic acid (ATRA) synthesis in retina will result in altering the circulatory levels of ATRA and regulating downstream gene expression and physiological function. Here we showed circulatory levels of ATRA decreased in mice under constant darkness and elevated by light exposure. Fat gene pancreatic lipase-related protein 2 (mPlrp2) and its partner procolipase (mClps), but not hepatic lipase (mHl), activated in livers for responding to lack of light illuminating. Light-triggered alterations in circulatory ATRA levels regulated ecto-5′-nucleotidase gene expression by retinoic acid receptor retinoic acid receptor-α and modulated 5′-AMP levels in blood and were associated with mPlrp2 and mClps expression in the livers. Mice deficient in adenosine receptors displayed mPlrp2 and mClps expression in livers under 12-h light, 12-h dark cycles. Caffeine blocked adenosine receptors and induced hepatic mPlrp2 and mClps expression in wild-type mice. Mice activated in hepatic mPlrp2 and mClps expression lowered hepatic and serum lipid levels and markedly elevated circulatory levels of all-trans retinol. Our results suggest environmental light influence hepatic lipid homeostasis by light-modulated retinoic acid signaling associated with mPlrp2 and mClps gene expression in livers.

scholarly journals Downregulation of c-fms gene expression in human monocytes treated with phorbol esters and colony-stimulating factor 1

Blood ◽  
1989 ◽  
Vol 74 (1) ◽  
pp. 123-129 ◽  
Author(s):  
E Sariban ◽  
K Imamura ◽  
M Sherman ◽  
V Rothwell ◽  
P Pantazis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Esters ◽  
Constitutive Expression ◽  
Human Monocytes ◽  
Colony Stimulating Factor ◽  
Protein Levels ◽  
Kinase C ◽  
Stimulating Factor

Abstract The colony-stimulating factor-1 (CSF-1) regulates survival, growth, and differentiation of monocytes by binding to a single class of high- affinity receptors. The CSF-1 receptor is identical to the product of the c-fms protooncogene. The present studies monitored the effects of TPA and CSF-1 on c-fms gene expression in human monocytes. The results demonstrate that TPA downmodulates the constitutive expression of c-fms mRNA to low but detectable levels. Treatment of human monocytes with TPA was similarly associated with decreases in levels of the 138- and 125-Kd c-fms-encoded proteins. However, the kinetics of c-fms protein downmodulation indicated independent effects of TPA on c-fms expression at the RNA and protein levels. Furthermore, c-fms protein levels subsequently recovered despite persistently low levels of c-fms mRNA. Although previous studies demonstrated that c-fms protein is down- regulated in the presence of CSF-1, the present results indicate that CSF-1 also downregulates levels of c-fms mRNA. Moreover, the results indicate that CSF-1 increases protein kinase C activity in the membrane fraction. Together, these findings suggest that c-fms gene expression is differentially regulated at both the RNA and protein levels after activation of protein kinase C in human monocytes treated with TPA and CSF-1.

scholarly journals Direct neuronal reprogramming by temporal identity factors

2021 ◽  
Author(s):  
Camille Boudreau-Pinsonneault ◽  
Awais Javed ◽  
Michel Fries ◽  
Pierre Mattar ◽  
Michel Cayouette
Keyword(s):  
Gene Expression ◽  
Expression System ◽  
Lineage Tracing ◽  
Developmental Competence ◽  
Rapid Screening ◽  
Mouse Retina ◽  
Genetic Lineage ◽  
Differentiated Cells ◽  
Temporal Identity

Temporal identity factors are sufficient to reprogram developmental competence of neural progenitors, but whether they could also reprogram the identity of fully differentiated cells is unknown. To address this question, we designed a conditional gene expression system combined with genetic lineage tracing that allows rapid screening of potential reprogramming factors in the mouse retina. Using this assay, we report that co-expression of the early temporal identity transcription factor Ikzf1, together with Ikzf4, another Ikaros family member, is sufficient to directly convert adult Muller glial cells into neuron-like cells in vivo, without inducing a proliferative progenitor state. scRNA-seq analysis shows that the reprogrammed cells share some transcriptional signatures with both cone photoreceptors and bipolar cells. Furthermore, we show that co-expression of Ikzf1 and Ikzf4 can reprogram mouse embryonic fibroblasts to induced neurons by remodeling chromatin and promoting a neuronal gene expression program. This work uncovers general neuronal reprogramming properties for temporal identity factors in differentiated cells, opening new opportunities for cell therapy development.

scholarly journals Lipid Metabolism Gene Expression And Cellularity of Intramuscular Adipocytes Within The Longissimus Muscle of Angus- And Wagyu-Sired Cattle When Raised To A Similar Age or Body Weight

2021 ◽  
Author(s):  
Jerad Jaborek ◽  
Francis Fluharty ◽  
Kichoon Lee ◽  
Henry Zerby ◽  
Alejandro Relling
Keyword(s):  
Gene Expression ◽  
Body Weight ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Binding Protein ◽  
Peroxisome Proliferator ◽  
Longissimus Muscle ◽  
Peroxisome Proliferator Activated Receptor ◽  
Lipid Metabolism Gene ◽  
Metabolism Gene

Abstract Background: This study investigates intramuscular (IM) adipocyte development and growth in the Longissimus muscle (LM) between Wagyu- and Angus-sired steers compared at a similar age and days on feed (DOF) endpoint or similar body weight (BW) endpoint by measuring IM adipocyte cell area and lipid metabolism gene expression. Methods: Angus-sired steers (AN, n=6) were compared with steers from two different Wagyu sires, selected for either growth or marbling, to be compared at a similar DOF (WA-GD, n=5 and WA-MD, n=5) in experiment 1 or BW (WA-GB, n=4 and WA-MB, n=5) in experiment 2, respectively. Results: In experiment 1, WA-MD steers had a greater percentage of IM fat in the LM compared with AN and WA-GD steers. In experiment 2, WA-MB steers had a greater percentage of IM fat in the LM compared with AN and WA-GB steers. The distribution of IM adipocyte area was unimodal at all biopsy collections, with IM adipocyte area becoming progressively larger as cattle age and BW increased (P≤0.01). Peroxisome proliferator activated receptor delta (PPARd) was upregulated earlier for WA-MD and WA-MB cattle compared with other steers at a similar age and BW (P≤0.02; treatment×biopsy interaction). An earlier upregulation of PPARd is believed to have then upregulated peroxisome proliferator activated receptor gamma (PPARg) at a lesser BW for WA-MB steers (P=0.09; treatment×biopsy interaction), while WA-MD steers had a greater (P≤0.04) overall mean PPARg expression compared with other steers. Glycerol-3-phosphate acyltransferase, lipin 1, and hormone sensitive lipase demonstrated expression patterns similar to PPARg and PPARd or CCAAT enhancer binding protein beta, which emphasizes their importance in marbling development and growth. Additionally, WA-MD and WA-MB steers often had a greater early expression of fatty acid transporters (fatty acid transport protein 1; P<0.02; treatment×biopsy interaction) and binding proteins (fatty acid binding protein 4) compared with other steers. With many lipolytic genes upregulated at harvest, acetyl-CoA carboxylase beta may be inhibiting fatty acid oxidation in the LM to allow greater IM fat accumulation.Conclusions: Cattle with a greater marbling propensity appear to upregulate adipogenesis at a lesser maturity through PPARd, PPARg, and possibly adipogenic regulating compounds in lysophosphatidic acid and diacylglycerol.

Control of hematopoietic cell growth regulators during mouse fetal development

1987 ◽  
Vol 7 (9) ◽  
pp. 3361-3364
Author(s):  
M Azoulay ◽  
C G Webb ◽  
L Sachs
Keyword(s):  
Gene Expression ◽  
Cell Growth ◽  
Growth Regulators ◽  
Fetal Development ◽  
Hematopoietic Cell ◽  
Regulatory Proteins ◽  
Colony Stimulating Factor ◽  
Cell Lineages ◽  
Stimulating Factor ◽  
Extraembryonic Tissues

Gene expression for the four different growth-regulatory proteins for cells of the myeloid hematopoietic cell lineages was analyzed in mouse fetal and extraembryonic tissues at various stages of development. The macrophage growth inducer MGI-1M (colony-stimulating factor 1) was the only myeloid hematopoietic growth regulator detected as both mRNA and bioactive protein during fetal development. This regulator was produced predominantly in extraembryonic tissues, and the production of hematopoietic growth regulators in embryogenesis was regulated by transcriptional and posttranscriptional controls.

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