scholarly journals Identification and characterization of a non-conventional CD45 negative perivascular macrophage population within the mouse brain.

Author(s):  
Carole Siret ◽  
Max van Lessen ◽  
Hyun-Woo Jeong ◽  
Shuaiwei Wang ◽  
Milesa Simic ◽  
...  

Abstract Perivascular macrophages (pvM) are closely associated with cerebral vasculature and play an essential role in drainage of the brain and regulation of the immune response. Here, using reporter mouse models and immunofluorescence on sections and whole brain, flow cytometry and single cell sequencing, we identify a Lyve1+ brain perivascular population lacking classical macrophage markers such as CD45 and Cx3cr1. We named the new non-conventional CD45 negative perivascular macrophages pvM2. These cells have a similar location, morphology and phagocytic function as conventional pvM. The pvM2 are not derived from hematopoietic stem cells, as they are negative in the VavtdT lineage tracing model. They increase in number after photothrombotic induced stroke established by flow cytometry and 3D immunofluorescence analysis. Since CD45 negative cells were typically excluded from macrophage studies, the presence of pvM2 has been previously missed and their role is of importance to assess in the brain disease models.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lars Velten ◽  
Benjamin A. Story ◽  
Pablo Hernández-Malmierca ◽  
Simon Raffel ◽  
Daniel R. Leonce ◽  
...  

AbstractCancer stem cells drive disease progression and relapse in many types of cancer. Despite this, a thorough characterization of these cells remains elusive and with it the ability to eradicate cancer at its source. In acute myeloid leukemia (AML), leukemic stem cells (LSCs) underlie mortality but are difficult to isolate due to their low abundance and high similarity to healthy hematopoietic stem cells (HSCs). Here, we demonstrate that LSCs, HSCs, and pre-leukemic stem cells can be identified and molecularly profiled by combining single-cell transcriptomics with lineage tracing using both nuclear and mitochondrial somatic variants. While mutational status discriminates between healthy and cancerous cells, gene expression distinguishes stem cells and progenitor cell populations. Our approach enables the identification of LSC-specific gene expression programs and the characterization of differentiation blocks induced by leukemic mutations. Taken together, we demonstrate the power of single-cell multi-omic approaches in characterizing cancer stem cells.


2019 ◽  
Vol 20 (8) ◽  
pp. 1856 ◽  
Author(s):  
Shengming Sun ◽  
Ying Wu ◽  
Hongtuo Fu ◽  
Xianping Ge ◽  
Hongzheng You ◽  
...  

Autophagy is a cytoprotective mechanism triggered in response to adverse environmental conditions. Herein, we investigated the autophagy process in the oriental river prawn (Macrobrachium nipponense) following hypoxia. Full-length cDNAs encoding autophagy-related genes (ATGs) ATG3, ATG4B, ATG5, and ATG9A were cloned, and transcription following hypoxia was explored in different tissues and developmental stages. The ATG3, ATG4B, ATG5, and ATG9A cDNAs include open reading frames encoding proteins of 319, 264, 268, and 828 amino acids, respectively. The four M. nipponense proteins clustered separately from vertebrate homologs in phylogenetic analysis. All four mRNAs were expressed in various tissues, with highest levels in brain and hepatopancreas. Hypoxia up-regulated all four mRNAs in a time-dependent manner. Thus, these genes may contribute to autophagy-based responses against hypoxia in M. nipponense. Biochemical analysis revealed that hypoxia stimulated anaerobic metabolism in the brain tissue. Furthermore, in situ hybridization experiments revealed that ATG4B was mainly expressed in the secretory and astrocyte cells of the brain. Silencing of ATG4B down-regulated ATG8 and decreased cell viability in juvenile prawn brains following hypoxia. Thus, autophagy is an adaptive response protecting against hypoxia in M. nipponense and possibly other crustaceans. Recombinant MnATG4B could interact with recombinant MnATG8, but the GST protein could not bind to MnATG8. These findings provide us with a better understanding of the fundamental mechanisms of autophagy in prawns.


Blood ◽  
2011 ◽  
Vol 118 (2) ◽  
pp. 289-297 ◽  
Author(s):  
Dongdong Ma ◽  
Jing Zhang ◽  
Hui-feng Lin ◽  
Joseph Italiano ◽  
Robert I. Handin

Abstract HSCs are defined by their ability to self-renew and maintain hematopoiesis throughout the lifespan of an organism. The optical clarity of their embryos and the ease of genetic manipulation make the zebrafish (Danio rerio) an excellent model for studying hematopoiesis. Using flow cytometry, we identified 2 populations of CD41-GFP+ cells (GFPhi and GFPlo) in the whole kidney marrow of Tg(CD41:GFP) zebrafish. Past studies in humans and mice have shown that CD41 is transiently expressed in the earliest hematopoietic progenitors and is then silenced, reappearing in the platelet/thrombocyte lineage. We have transplanted flow-sorted GFPhi and GFPlo cells into irradiated adult zebrafish and assessed long-term hematopoietic engraftment. Transplantation of GFPhi cells did not reconstitute hematopoiesis. In contrast, we observed multilineage hematopoiesis up to 68 weeks after primary and secondary transplantation of GFPlo cells. We detected the CD41-GFP transgene in all major hematopoietic lineages and CD41-GFP+ cells in histologic sections of kidneys from transplant recipients. These studies show that CD41-GFPlo cells fulfill generally accepted criteria for HSCs. The identification of fluorescent zebrafish HSCs, coupled with our ability to transplant them into irradiated adult recipients, provide a valuable new tool to track HSC homing, proliferation, and differentiation into hematopoietic cells.


Author(s):  
Francesco Tavanti ◽  
Alfonso Pedone ◽  
Maria Cristina Menziani

One of the principal hallmarks of Alzheimer’s disease (AD) is related to the aggregation of amyloid-β fibrils in an insoluble form in the brain, also known as amyloidosis. Therefore, a prominent therapeutic strategy against AD consists either in blocking the amyloid aggregation and/or destroying the already formed aggregates. Natural products have shown significant therapeutic potential as amyloid inhibitors from in vitro studies as well as in vivo animal tests. In this study, the interaction of five natural biophenols (curcumin, dopamine, (-)-Epigallocatechin-3-gallate, Quercetin, and Rosmarinic acid) with the amyloid-β(1-40) fibrils has been studied through computational simulations. The results allowed the identification and characterization of the different binding modalities of each compounds and their consequences on fibril dynamics and aggregation. It emerges that the lateral aggregation of the fibrils is strongly influenced by the intercalation of the ligands, which modulate the double-layered structure stability.


Hepatology ◽  
1987 ◽  
Vol 7 (4) ◽  
pp. 696-703 ◽  
Author(s):  
Mark Doolittle ◽  
Roger Bohman ◽  
Andres Durstenfeld ◽  
Joseph Cascarano

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