scholarly journals Integrated Patterning Programs During Drosophila Development Generate the Diversity of Neurons and Control Their Mature Properties

2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Anthony M. Rossi ◽  
Shadi Jafari ◽  
Claude Desplan
Keyword(s):  
Stem Cells ◽  
Nervous System ◽  
Neural Stem Cells ◽  
Cell Types ◽  
Annual Review ◽  
Publication Date ◽  
Temporal Patterning ◽  
Long Time ◽  
Neuronal Types ◽  
And Control

During the approximately 5 days of Drosophila neurogenesis (late embryogenesis to the beginning of pupation), a limited number of neural stem cells produce approximately 200,000 neurons comprising hundreds of cell types. To build a functional nervous system, neuronal types need to be produced in the proper places, appropriate numbers, and correct times. We discuss how neural stem cells (neuroblasts) obtain so-called area codes for their positions in the nervous system (spatial patterning) and how they keep time to sequentially produce neurons with unique fates (temporal patterning). We focus on specific examples that demonstrate how a relatively simple patterning system (Notch) can be used reiteratively to generate different neuronal types. We also speculate on how different modes of temporal patterning that operate over short versus long time periods might be linked. We end by discussing how specification programs are integrated and lead to the terminal features of different neuronal types. Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Spatial Transcriptomics: Molecular Maps of the Mammalian Brain

2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Cantin Ortiz ◽  
Marie Carlén ◽  
Konstantinos Meletis
Keyword(s):  
Nervous System ◽  
Molecular Classification ◽  
Cell Types ◽  
Brain Regions ◽  
Mammalian Brain ◽  
Annual Review ◽  
Publication Date ◽  
Common Reference ◽  
Tissue Organization ◽  
Definition Of

Maps of the nervous system inspire experiments and theories in neuroscience. Advances in molecular biology over the past decades have revolutionized the definition of cell and tissue identity. Spatial transcriptomics has opened up a new era in neuroanatomy, where the unsupervised and unbiased exploration of the molecular signatures of tissue organization will give rise to a new generation of brain maps. We propose that the molecular classification of brain regions on the basis of their gene expression profile can circumvent subjective neuroanatomical definitions and produce common reference frameworks that can incorporate cell types, connectivity, activity, and other modalities. Here we review the technological and conceptual advances made possible by spatial transcriptomics in the context of advancing neuroanatomy and discuss how molecular neuroanatomy can redefine mapping of the nervous system. Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Epithelial Stem and Progenitor Cells in Lung Repair and Regeneration

2020 ◽  
Vol 83 (1) ◽  
Author(s):  
Konstantinos-Dionysios Alysandratos ◽  
Michael J. Herriges ◽  
Darrell N. Kotton
Keyword(s):  
Stem Cells ◽  
Pluripotent Stem Cells ◽  
Cell Types ◽  
Annual Review ◽  
Publication Date ◽  
Lung Epithelium ◽  
Lung Epithelial ◽  
Stem And Progenitor Cells ◽  
Mammalian Lung ◽  
Shed Light

The mammalian lung epithelium is composed of a wide array of specialized cells that have adapted to survive environmental exposure and perform the tasks necessary for respiration. Although the majority of these cells are remarkably quiescent during adult lung homeostasis, a growing body of literature has demonstrated the capacity of these epithelial lineages to proliferate in response to injury and regenerate lost or damaged cells. In this review, we focus on the regionally distinct lung epithelial cell types that contribute to repair after injury, and we address current controversies regarding whether elite stem cells or frequent facultative progenitors are the predominant participants. We also shed light on the newly emerging approaches for exogenously generating similar lung epithelial lineages from pluripotent stem cells. Expected final online publication date for the Annual Review of Physiology, Volume 83 is February 10, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Identification of enhancers that drive the spatially restricted expression of Vsx1 and Rx in the outer proliferation center of the developing Drosophila optic lobe

Genome ◽  
2020 ◽  
pp. 1-9
Author(s):  
Ishrat Maliha Islam ◽  
June Ng ◽  
Priscilla Valentino ◽  
Ted Erclik
Keyword(s):  
Stem Cells ◽  
Transcription Factors ◽  
Neural Stem Cells ◽  
Optic Lobe ◽  
Cell Types ◽  
Temporal Patterning ◽  
Spatial Factors ◽  
Conserved Sequences ◽  
Evolutionarily Conserved ◽  
Powerful Mechanism

Combinatorial spatial and temporal patterning of stem cells is a powerful mechanism for the generation of neural diversity in insect and vertebrate nervous systems. In the developing Drosophila medulla, the neural stem cells of the outer proliferation center (OPC) are spatially patterned by the mutually exclusive expression of three homeobox transcription factors: Vsx1 in the center of the OPC crescent (cOPC), Optix in the main arms (mOPC), and Rx in the posterior tips (pOPC). These spatial factors act together with a temporal cascade of transcription factors in OPC neuroblasts to specify the greater than 80 medulla cell types. Here, we identify the enhancers that are sufficient to drive the spatially restricted expression of the Vsx1 and Rx genes in the OPC. We show that removal of the cOPC enhancer in the Muddled inversion mutant leads to the loss of Vsx1 expression in the cOPC. Analysis of the evolutionarily conserved sequences within these enhancers suggests that direct repression by Optix may restrict the expression of Vsx1 and Rx to the cOPC and pOPC, respectively.

Seq Your Destiny: Neural Crest Fate Determination in the Genomic Era

2021 ◽  
Vol 55 (1) ◽  
Author(s):  
Shashank Gandhi ◽  
Marianne E. Bronner
Keyword(s):  
Nervous System ◽  
Neural Crest ◽  
Cell Lineage ◽  
Cell Types ◽  
The Body ◽  
Annual Review ◽  
Publication Date ◽  
Developmental Potential ◽  
Migratory Patterns ◽  
Modern Genomic

Neural crest stem/progenitor cells arise early during vertebrate embryogenesis at the border of the forming central nervous system. They subsequently migrate throughout the body, eventually differentiating into diverse cell types ranging from neurons and glia of the peripheral nervous system to bones of the face, portions of the heart, and pigmentation of the skin. Along the body axis, the neural crest is heterogeneous, with different subpopulations arising in the head, neck, trunk, and tail regions, each characterized by distinct migratory patterns and developmental potential. Modern genomic approaches like single-cell RNA- and ATAC-sequencing (seq) have greatly enhanced our understanding of cell lineage trajectories and gene regulatory circuitry underlying the developmental progression of neural crest cells. Here, we discuss how genomic approaches have provided new insights into old questions in neural crest biology by elucidating transcriptional and posttranscriptional mechanisms that govern neural crest formation and the establishment of axial level identity. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Epigenetic Signatures and Plasticity of Intestinal and Other Stem Cells

2020 ◽  
Vol 83 (1) ◽  
Author(s):  
Madhurima Saxena ◽  
Ramesh A. Shivdasani
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Activity ◽  
Cell Types ◽  
Regulatory Elements ◽  
Annual Review ◽  
Publication Date ◽  
Specific Cell ◽  
Resident Cell ◽  
Stem Cell Activity

The cardinal properties of adult tissue stem cells are self-renewal and the ability to generate diverse resident cell types. The daily losses of terminally differentiated intestinal, skin, and blood cells require “professional” stem cells to produce replacements. This occurs by continuous expansion of stem cells and their immediate progeny, followed by coordinated activation of divergent transcriptional programs to generate stable cells with diverse functions. Other tissues turn over slowly, if at all, and vary widely in strategies for facultative stem cell activity or interconversion among mature resident cell types (transdifferentiation). Cell fate potential is programmed in tissue-specific configurations of chromatin, which restrict the complement of available genes and cis-regulatory elements, hence allowing specific cell types to arise. Using as a model the transcriptional and chromatin basis of cell differentiation and dedifferentiation in intestinal crypts, we discuss here how self-renewing and other tissues execute homeostatic and injury-responsive stem cell activity. Expected final online publication date for the Annual Review of Physiology, Volume 83 is February 10, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Neural Stem Cells to Glial Cells an Important Factor for Brain Injury

2020 ◽  
Author(s):  
Prithiv K R Kumar
Keyword(s):  
Stem Cells ◽  
Central Nervous System ◽  
Nervous System ◽  
Neural Stem Cells ◽  
Glial Cells ◽  
Brain Injuries ◽  
The Body ◽  
The Central Nervous System ◽  
Near Future

Stem cells have the capacity to differentiate into any type of cell or organ. Stems cell originate from any part of the body, including the brain. Brain cells or rather neural stem cells have the capacitive advantage of differentiating into the central nervous system leading to the formation of neurons and glial cells. Neural stem cells should have a source by editing DNA, or by mixings chemical enzymes of iPSCs. By this method, a limitless number of neuron stem cells can be obtained. Increase in supply of NSCs help in repairing glial cells which in-turn heal the central nervous system. Generally, brain injuries cause motor and sensory deficits leading to stroke. With all trials from novel therapeutic methods to enhanced rehabilitation time, the economy and quality of life is suppressed. Only PSCs have proven effective for grafting cells into NSCs. Neurons derived from stem cells is the only challenge that limits in-vitro usage in the near future.

scholarly journals Neural Stem Cells: What Happens When They Go Viral?

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1468
Author(s):  
Yashika S. Kamte ◽  
Manisha N. Chandwani ◽  
Alexa C. Michaels ◽  
Lauren A. O’Donnell
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Viral Infections ◽  
Wide Spectrum ◽  
Cell Types ◽  
Developmental Abnormalities ◽  
Multipotent Progenitor Cells ◽  
The Central Nervous System ◽  
Simplex Virus ◽  
The Brain

Viruses that infect the central nervous system (CNS) are associated with developmental abnormalities as well as neuropsychiatric and degenerative conditions. Many of these viruses such as Zika virus (ZIKV), cytomegalovirus (CMV), and herpes simplex virus (HSV) demonstrate tropism for neural stem cells (NSCs). NSCs are the multipotent progenitor cells of the brain that have the ability to form neurons, astrocytes, and oligodendrocytes. Viral infections often alter the function of NSCs, with profound impacts on the growth and repair of the brain. There are a wide spectrum of effects on NSCs, which differ by the type of virus, the model system, the cell types studied, and the age of the host. Thus, it is a challenge to predict and define the consequences of interactions between viruses and NSCs. The purpose of this review is to dissect the mechanisms by which viruses can affect survival, proliferation, and differentiation of NSCs. This review also sheds light on the contribution of key antiviral cytokines in the impairment of NSC activity during a viral infection, revealing a complex interplay between NSCs, viruses, and the immune system.

Evaluation of the Effect of Hyaluronic Acid–Based Biomaterial Enriched With Tenascin-C on the Behavior of the Neural Stem Cells

2021 ◽  
pp. 109158182110024
Author(s):  
Maryam Shahi ◽  
Daruosh Mohammadnejad ◽  
Mohammad Karimipour ◽  
Reza Rahbarghazi ◽  
Ali Abedelahi
Keyword(s):  
Stem Cells ◽  
Hyaluronic Acid ◽  
Neural Stem Cells ◽  
Mtt Assay ◽  
Dapi Staining ◽  
Biological Assays ◽  
Tenascin C ◽  
Electron Scanning Microscopy ◽  
Ethidium Bromide Staining ◽  
And Control

One of the most important natural extracellular constituents is hyaluronic acid (HA) with the potential to develop a highly organized microenvironment. In the present study, we enriched HA hydrogel with tenascin-C (TN-C) and examined the viability and survival of mouse neural stem cells (NSCs) using different biological assays. Following NSCs isolation and expansion, their phenotype was identified using flow cytometry analysis. Cell survival was measured using MTT assay and DAPI staining after exposure to various concentrations of 50, 100, 200, and 400 nM TN-C. Using acridine orange/ethidium bromide staining, we measured the number of live and necrotic cells after exposure to the combination of HA and TN-C. MTT assay revealed the highest NSCs viability rate in the group exposed to 100 nM TN-C compared to other groups, and a combination of 1% HA + 100 nM TN-C increased the viability of NSCs compared to the HA group after 24 hours. Electron scanning microscopy revealed the higher attachment of these cells to the HA + 100 nM TN-C substrate relative to the HA substrate. Epifluorescence imaging and DAPI staining of loaded cells on HA + 100 nM TN-C substrate significantly increased the number of NSCs per field over 72 hours compared to the HA group ( P < 0.05). Live and dead assay revealed that the number of live NSCs significantly increased in the HA + 100 TN-C group compared to HA and control groups. The enrichment of HA substrate with TN-C promoted viability and survival of NSCs and could be applied in neural tissue engineering approaches and regenerative medicine.

Pathogenic Mechanisms Underlying Idiopathic Pulmonary Fibrosis

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Benjamin J. Moss ◽  
Stefan W. Ryter ◽  
Ivan O. Rosas
Keyword(s):  
Epithelial Cell ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Cell Activation ◽  
Alveolar Epithelial Cell ◽  
Cell Types ◽  
Annual Review ◽  
Publication Date ◽  
Metabolic Dysfunction ◽  
Epithelial Repair

The pathogenesis of idiopathic pulmonary fibrosis (IPF) involves a complex interplay of cell types and signaling pathways. Recurrent alveolar epithelial cell (AEC) injury may occur in the context of predisposing factors (e.g., genetic, environmental, epigenetic, immunologic, and gerontologic), leading to metabolic dysfunction, senescence, aberrant epithelial cell activation, and dysregulated epithelial repair. The dysregulated epithelial cell interacts with mesenchymal, immune, and endothelial cells via multiple signaling mechanisms to trigger fibroblast and myofibroblast activation. Recent single-cell RNA sequencing studies of IPF lungs support the epithelial injury model. These studies have uncovered a novel type of AEC with characteristics of an aberrant basal cell, which may disrupt normal epithelial repair and propagate a profibrotic phenotype. Here, we review the pathogenesis of IPF in the context of novel bioinformatics tools as strategies to discover pathways of disease, cell-specific mechanisms, and cell-cell interactions that propagate the profibrotic niche. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease, Volume 17 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Design and Control of Drones

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Mark W. Mueller ◽  
Seung Jae Lee ◽  
Raffaello D’Andrea
Keyword(s):  
Energy Consumption ◽  
Motion Planning ◽  
Recent Progress ◽  
Scaling Laws ◽  
Autonomous Systems ◽  
Annual Review ◽  
Publication Date ◽  
Trade Offs ◽  
Active Research ◽  
And Control

The design and control of drones remain areas of active research, and here we review recent progress in this field. In this article, we discuss the design objectives and related physical scaling laws, focusing on energy consumption, agility and speed, and survivability and robustness. We divide the control of such vehicles into low-level stabilization and higher-level planning such as motion planning, and we argue that a highly relevant problem is the integration of sensing with control and planning. Lastly, we describe some vehicle morphologies and the trade-offs that they represent. We specifically compare multicopters with winged designs and consider the effects of multivehicle teams. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 5 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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