Paligenosis: Cellular Remodeling During Tissue Repair

2021 ◽  
Vol 84 (1) ◽  
Author(s):  
Jeffrey W. Brown ◽  
Charles J. Cho ◽  
Jason C. Mills
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Tissue Repair ◽  
Annual Review ◽  
Publication Date ◽  
Cell Plasticity ◽  
Evolutionarily Conserved ◽  
Single Cell Rna Sequencing ◽  
Multicellular Organisms ◽  
New Framework

Complex multicellular organisms have evolved specific mechanisms to replenish cells in homeostasis and during repair. Here, we discuss how emerging technologies (e.g., single-cell RNA sequencing) challenge the concept that tissue renewal is fueled by unidirectional differentiation from a resident stem cell. We now understand that cell plasticity, i.e., cells adaptively changing differentiation state or identity, is a central tissue renewal mechanism. For example, mature cells can access an evolutionarily conserved program (paligenosis) to reenter the cell cycle and regenerate damaged tissue. Most tissues lack dedicated stem cells and rely on plasticity to regenerate lost cells. Plasticity benefits multicellular organisms, yet it also carries risks. For one, when long-lived cells undergo paligenotic, cyclical proliferation and redifferentiation, they can accumulate and propagate acquired mutations that activate oncogenes and increase the potential for developing cancer. Lastly, we propose a new framework for classifying patterns of cell proliferation in homeostasis and regeneration, with stem cells representing just one of the diverse methods that adult tissues employ. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Immunosensation: Neuroimmune Cross Talk in the Skin

2021 ◽  
Vol 39 (1) ◽  
Author(s):  
Masato Tamari ◽  
Aaron M. Ver Heul ◽  
Brian S. Kim
Keyword(s):  
Immune System ◽  
Host Immunity ◽  
The Body ◽  
Annual Review ◽  
Publication Date ◽  
Protective Behaviors ◽  
Evolutionarily Conserved ◽  
Structural Barrier ◽  
Thermal Stimuli ◽  
Antimicrobial Immunity

Classically, skin was considered a mere structural barrier protecting organisms from a diversity of environmental insults. In recent decades, the cutaneous immune system has become recognized as a complex immunologic barrier involved in both antimicrobial immunity and homeostatic processes like wound healing. To sense a variety of chemical, mechanical, and thermal stimuli, the skin harbors one of the most sophisticated sensory networks in the body. However, recent studies suggest that the cutaneous nervous system is highly integrated with the immune system to encode specific sensations into evolutionarily conserved protective behaviors. In addition to directly sensing pathogens, neurons employ novel neuroimmune mechanisms to provide host immunity. Therefore, given that sensation underlies various physiologies through increasingly complex reflex arcs, a much more dynamic picture is emerging of the skin as a truly systemic organ with highly coordinated physical, immunologic, and neural functions in barrier immunology. Expected final online publication date for the Annual Review of Immunology, Volume 39 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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.

Dissecting Organismal Morphogenesis by Bridging Genetics and Biophysics

2021 ◽  
Vol 55 (1) ◽  
Author(s):  
Nikhil Mishra ◽  
Carl-Philipp Heisenberg
Keyword(s):  
Cell Fate ◽  
Regulatory Networks ◽  
Annual Review ◽  
Publication Date ◽  
Technological Advances ◽  
Complex Shapes ◽  
Gene Regulatory ◽  
And Mathematics ◽  
Multicellular Organisms ◽  
Shape Changes

Multicellular organisms develop complex shapes from much simpler, single-celled zygotes through a process commonly called morphogenesis. Morphogenesis involves an interplay between several factors, ranging from the gene regulatory networks determining cell fate and differentiation to the mechanical processes underlying cell and tissue shape changes. Thus, the study of morphogenesis has historically been based on multidisciplinary approaches at the interface of biology with physics and mathematics. Recent technological advances have further improved our ability to study morphogenesis by bridging the gap between the genetic and biophysical factors through the development of new tools for visualizing, analyzing, and perturbing these factors and their biochemical intermediaries. Here, we review how a combination of genetic, microscopic, biophysical, and biochemical approaches has aided our attempts to understand morphogenesis and discuss potential approaches that may be beneficial to such an inquiry in the future. 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.

Cardiac Regeneration: New Hope for an Old Dream

2020 ◽  
Vol 83 (1) ◽  
Author(s):  
Florian Weinberger ◽  
Thomas Eschenhagen
Keyword(s):  
Cell Cycle ◽  
Public Health Problem ◽  
Cardiac Regeneration ◽  
Annual Review ◽  
Publication Date ◽  
Major Public Health Problem ◽  
Regenerative Capacity ◽  
Heart Repair ◽  
Technology Strategies ◽  
Regenerative Therapies

The regenerative capacity of the heart has long fascinated scientists. In contrast to other organs such as liver, skin, and skeletal muscle, the heart possesses only a minimal regenerative capacity. It lacks a progenitor cell population, and cardiomyocytes exit the cell cycle shortly after birth and do not re-enter after injury. Thus, any loss of cardiomyocytes is essentially irreversible and can lead to or exaggerate heart failure, which represents a major public health problem. New therapeutic options are urgently needed, but regenerative therapies have remained an unfulfilled promise in cardiovascular medicine until today. Yet, through a clearer comprehension of signaling pathways that regulate the cardiomyocyte cell cycle and advances in stem cell technology, strategies have evolved that demonstrate the potential to generate new myocytes and thereby fulfill an essential central criterion for heart repair. 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.

Regulation of the Plant Cell Cycle in Response to Hormones and the Environment

2021 ◽  
Vol 72 (1) ◽  
Author(s):  
Akie Shimotohno ◽  
Shiori S. Aki ◽  
Naoki Takahashi ◽  
Masaaki Umeda
Keyword(s):  
Cell Cycle ◽  
Plant Cell ◽  
Cell Cycle Progression ◽  
Current Model ◽  
Annual Review ◽  
Publication Date ◽  
Cell Cycle Regulators ◽  
Environmental Signals ◽  
Plant Cell Cycle ◽  
Internal And External Factors

Developmental and environmental signals converge on cell cycle machinery to achieve proper and flexible organogenesis under changing environments. Studies on the plant cell cycle began 30 years ago, and accumulated research has revealed many links between internal and external factors and the cell cycle. In this review, we focus on how phytohormones and environmental signals regulate the cell cycle to enable plants to cope with a fluctuating environment. After introducing key cell cycle regulators, we first discuss how phytohormones and their synergy are important for regulating cell cycle progression and how environmental factors positively and negatively affect cell division. We then focus on the well-studied example of stress-induced G2 arrest and view the current model from an evolutionary perspective. Finally, we discuss the mechanisms controlling the transition from the mitotic cycle to the endocycle, which greatly contributes to cell enlargement and resultant organ growth in plants. Expected final online publication date for the Annual Review of Plant Biology, Volume 72 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Biophysics of Notch Signaling

2021 ◽  
Vol 50 (1) ◽  
Author(s):  
David Sprinzak ◽  
Stephen C. Blacklow
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Annual Review ◽  
Publication Date ◽  
Dynamic Features ◽  
Signaling Mechanism ◽  
Cell Fate Decisions ◽  
Notch Intracellular Domain ◽  
Numerous Cell ◽  
Multicellular Organisms

Notch signaling is a conserved system of communication between adjacent cells, influencing numerous cell fate decisions in the development of multicellular organisms. Aberrant signaling is also implicated in many human pathologies. At its core, Notch has a mechanotransduction module that decodes receptor–ligand engagement at the cell surface under force to permit proteolytic cleavage of the receptor, leading to the release of the Notch intracellular domain (NICD). NICD enters the nucleus and acts as a transcriptional effector to regulate expression of Notch-responsive genes. In this article, we review and integrate current understanding of the detailed molecular basis for Notch signal transduction, highlighting quantitative, structural, and dynamic features of this developmentally central signaling mechanism. We discuss the implications of this mechanistic understanding for the functionality of the signaling pathway in different molecular and cellular contexts. Expected final online publication date for the Annual Review of Biophysics, Volume 50 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Dynamic Nutrient Signaling Networks in Plants

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Lei Li ◽  
Kun-hsiang Liu ◽  
Jen Sheen
Keyword(s):  
Plant Biomass ◽  
Metabolic Reprogramming ◽  
Signaling Networks ◽  
Annual Review ◽  
Publication Date ◽  
Cellular Mechanisms ◽  
Growth And Survival ◽  
Coordinate Gene Expression ◽  
Evolutionarily Conserved ◽  
Nutrient Signaling

Nutrients are vital to life through intertwined sensing, signaling, and metabolic processes. Emerging research focuses on how distinct nutrient signaling networks integrate and coordinate gene expression, metabolism, growth, and survival. We review the multifaceted roles of sugars, nitrate, and phosphate as essential plant nutrients in controlling complex molecular and cellular mechanisms of dynamic signaling networks. Key advances in central sugar and energy signaling mechanisms mediated by the evolutionarily conserved master regulators HEXOKINASE1 (HXK1), TARGET OF RAPAMYCIN (TOR), and SNF1-RELATED PROTEIN KINASE1 (SNRK1) are discussed. Significant progress in primary nitrate sensing, calcium signaling, transcriptome analysis, and root–shoot communication to shape plant biomass and architecture are elaborated. Discoveries on intracellular and extracellular phosphate signaling and the intimate connections with nitrate and sugar signaling are examined. This review highlights the dynamic nutrient, energy, growth, and stress signaling networks that orchestrate systemwide transcriptional, translational, and metabolic reprogramming, modulate growth and developmental programs, and respond to environmental cues. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Young Children's Interactions with Objects: Play as Practice and Practice as Play

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Jeffrey J. Lockman ◽  
Catherine S. Tamis-LeMonda
Keyword(s):  
Developmental Psychology ◽  
The Self ◽  
Annual Review ◽  
Publication Date ◽  
Unified Framework ◽  
Manual Skill ◽  
Immense Potential ◽  
New Framework ◽  
Imagined Interactions ◽  
Play Development

Objects permeate human culture and saturate the imagination. This duality offers both opportunity and challenge. Here we ask how young human children learn to exploit the immense potential afforded by objects that can exist simultaneously in physical and imaginary realms. To this end, we advance a new framework that integrates the presently siloed literatures on manual skill and play development. We argue that developments in children's real and imagined use of objects are embodied, reciprocal, and intertwined. Advances in one plane of action influence and scaffold advances in the other. Consistent with this unified framework, we show how real and imagined interactions with objects are characterized by developmental parallels in how children ( a) transcend the present to encompass future points in time and space, ( b) extend beyond the self, and ( c) gradually move beyond objects’ designed functions. In addition, we highlight bidirectional influences in children's real and imagined interactions with objects: Play engenders practice and skill in using objects, but just the same, practice using objects engenders advances in play. We close by highlighting the theoretical, empirical, and translational implications of this embodied and integrated account of manual skill and play development. Expected final online publication date for the Annual Review of Developmental Psychology, Volume 3 is December 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.

scholarly journals Cell cycle heterogeneity directs the timing of neural stem cell activation from quiescence

Science ◽  
2018 ◽  
Vol 360 (6384) ◽  
pp. 99-102 ◽  
Author(s):  
L. Otsuki ◽  
A. H. Brand
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Neural Stem Cells ◽  
Signaling Pathway ◽  
Insulin Signaling ◽  
Cell Activation ◽  
Akt Activation ◽  
Evolutionarily Conserved ◽  
Quiescent Stem Cells

Quiescent stem cells in adult tissues can be activated for homeostasis or repair. Neural stem cells (NSCs) in Drosophila are reactivated from quiescence in response to nutrition by the insulin signaling pathway. It is widely accepted that quiescent stem cells are arrested in G0. In this study, however, we demonstrate that quiescent NSCs (qNSCs) are arrested in either G2 or G0. G2-G0 heterogeneity directs NSC behavior: G2 qNSCs reactivate before G0 qNSCs. In addition, we show that the evolutionarily conserved pseudokinase Tribbles (Trbl) induces G2 NSCs to enter quiescence by promoting degradation of Cdc25String and that it subsequently maintains quiescence by inhibiting Akt activation. Insulin signaling overrides repression of Akt and silences trbl transcription, allowing NSCs to exit quiescence. Our results have implications for identifying and manipulating quiescent stem cells for regenerative purposes.

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