scholarly journals A shared transcriptional code orchestrates temporal patterning of the central nervous system

PLoS Biology ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. e3001450
Author(s):  
Andreas Sagner ◽  
Isabel Zhang ◽  
Thomas Watson ◽  
Jorge Lazaro ◽  
Manuela Melchionda ◽  
...  

The molecular mechanisms that produce the full array of neuronal subtypes in the vertebrate nervous system are incompletely understood. Here, we provide evidence of a global temporal patterning program comprising sets of transcription factors that stratifies neurons based on the developmental time at which they are generated. This transcriptional code acts throughout the central nervous system, in parallel to spatial patterning, thereby increasing the diversity of neurons generated along the neuraxis. We further demonstrate that this temporal program operates in stem cell−derived neurons and is under the control of the TGFβ signaling pathway. Targeted perturbation of components of the temporal program, Nfia and Nfib, reveals their functional requirement for the generation of late-born neuronal subtypes. Together, our results provide evidence for the existence of a previously unappreciated global temporal transcriptional program of neuronal subtype identity and suggest that the integration of spatial and temporal patterning mechanisms diversifies and organizes neuronal subtypes in the vertebrate nervous system.

Author(s):  
Andreas Sagner ◽  
Isabel Zhang ◽  
Thomas Watson ◽  
Jorge Lazaro ◽  
Manuela Melchionda ◽  
...  

AbstractThe molecular mechanisms that ensure the reproducible generation of neuronal diversity in the vertebrate nervous system are incompletely understood. Here we provide evidence of a temporal patterning program consisting of cohorts of transcription factors expressed in neurons generated at successive developmental timepoints. This program acts in parallel to spatial patterning, diversifying neurons throughout the nervous system and in neurons differentiated in-vitro from stem cells. We demonstrate the TGFβ signalling pathway controls the pace of the temporal program. Furthermore, targeted perturbation of components of the temporal program, Nfia and Nfib, reveals their requirement for the generation of late-born neuronal subtypes. Together, our results provide evidence for the existence of a previously unappreciated global temporal program of neuronal subtype identity and suggest that the integration of spatial and temporal patterning programs diversifies and organises neuronal subtypes in the vertebrate nervous system.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mar Pacheco-Herrero ◽  
Luis O. Soto-Rojas ◽  
Charles R. Harrington ◽  
Yazmin M. Flores-Martinez ◽  
Marcos M. Villegas-Rojas ◽  
...  

The current pandemic caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a public health emergency. To date, March 1, 2021, coronavirus disease 2019 (COVID-19) has caused about 114 million accumulated cases and 2.53 million deaths worldwide. Previous pieces of evidence suggest that SARS-CoV-2 may affect the central nervous system (CNS) and cause neurological symptoms in COVID-19 patients. It is also known that angiotensin-converting enzyme-2 (ACE2), the primary receptor for SARS-CoV-2 infection, is expressed in different brain areas and cell types. Thus, it is hypothesized that infection by this virus could generate or exacerbate neuropathological alterations. However, the molecular mechanisms that link COVID-19 disease and nerve damage are unclear. In this review, we describe the routes of SARS-CoV-2 invasion into the central nervous system. We also analyze the neuropathologic mechanisms underlying this viral infection, and their potential relationship with the neurological manifestations described in patients with COVID-19, and the appearance or exacerbation of some neurodegenerative diseases.


2021 ◽  
Vol 15 ◽  
Author(s):  
Davide Marangon ◽  
Nicolò Caporale ◽  
Marta Boccazzi ◽  
Maria P. Abbracchio ◽  
Giuseppe Testa ◽  
...  

Myelin is the lipidic insulating structure enwrapping axons and allowing fast saltatory nerve conduction. In the central nervous system, myelin sheath is the result of the complex packaging of multilamellar extensions of oligodendrocyte (OL) membranes. Before reaching myelinating capabilities, OLs undergo a very precise program of differentiation and maturation that starts from OL precursor cells (OPCs). In the last 20 years, the biology of OPCs and their behavior under pathological conditions have been studied through several experimental models. When co-cultured with neurons, OPCs undergo terminal maturation and produce myelin tracts around axons, allowing to investigate myelination in response to exogenous stimuli in a very simple in vitro system. On the other hand, in vivo models more closely reproducing some of the features of human pathophysiology enabled to assess the consequences of demyelination and the molecular mechanisms of remyelination, and they are often used to validate the effect of pharmacological agents. However, they are very complex, and not suitable for large scale drug discovery screening. Recent advances in cell reprogramming, biophysics and bioengineering have allowed impressive improvements in the methodological approaches to study brain physiology and myelination. Rat and mouse OPCs can be replaced by human OPCs obtained by induced pluripotent stem cells (iPSCs) derived from healthy or diseased individuals, thus offering unprecedented possibilities for personalized disease modeling and treatment. OPCs and neural cells can be also artificially assembled, using 3D-printed culture chambers and biomaterial scaffolds, which allow modeling cell-to-cell interactions in a highly controlled manner. Interestingly, scaffold stiffness can be adopted to reproduce the mechanosensory properties assumed by tissues in physiological or pathological conditions. Moreover, the recent development of iPSC-derived 3D brain cultures, called organoids, has made it possible to study key aspects of embryonic brain development, such as neuronal differentiation, maturation and network formation in temporal dynamics that are inaccessible to traditional in vitro cultures. Despite the huge potential of organoids, their application to myelination studies is still in its infancy. In this review, we shall summarize the novel most relevant experimental approaches and their implications for the identification of remyelinating agents for human diseases such as multiple sclerosis.


Psychiatry ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 125-134
Author(s):  
E. F. Vasilyeva ◽  
O. S. Brusov

Background: at present, the important role of the monocyte-macrophage link of immunity in the pathogenesis of mental diseases has been determined. In the first and second parts of our review, the cellular and molecular mechanisms of activation of monocytes/macrophages, which secreting proinflammatory CD16 receptors, cytokines, chemokines and receptors to them, in the development of systemic immune inflammation in the pathogenesis of somatic diseases and mental disorders, including schizophrenia, bipolar affective disorder (BAD) and depression were analyzed. The association of high levels of proinflammatory activity of monocytes/macrophages in patients with mental disorders with somatic comorbidity, including immune system diseases, is shown. It is known that proinflammatory monocytes of peripheral blood, as a result of violation of the integrity of the hematoencephalic barrier can migrate to the central nervous system and activate the resident brain cells — microglia, causing its activation. Activation of microglia can lead to the development of neuroinammation and neurodegenerative processes in the brain and, as a result, to cognitive disorders. The aim of review: to analyze the results of the main scientific studies concerning the role of cellular and molecular mechanisms of peripheral blood monocytes interaction with microglial cells and platelets in the development of neuroinflammation in the pathogenesis of mental disorders, including Alzheimer’s disease (AD). Material and methods: keywords “mental disorders, AD, proinflammatory monocytes, microglia, neuroinflammation, cytokines, chemokines, cell adhesion molecules, platelets, microvesicles” were used to search for articles of domestic and foreign authors published over the past 30 years in the databases PubMed, eLibrary, Science Direct and EMBASE. Conclusion: this review analyzes the results of studies which show that monocytes/macrophages and microglia have similar gene expression profiles in schizophrenia, BAD, depression, and AD and also perform similar functions: phagocytosis and inflammatory responses. Monocytes recruited to the central nervous system stimulate the increased production of proinflammatory cytokines IL-1, IL-6, tumor necrosis factor alpha (TNF-α), chemokines, for example, MCP-1 (Monocyte chemotactic protein-1) by microglial cells. This promotes the recruitment of microglial cells to the sites of neuronal damage, and also enhances the formation of the brain protein beta-amyloid (Aβ). The results of modern studies are presented, indicating that platelets are involved in systemic inflammatory reactions, where they interact with monocytes to form monocyte-platelet aggregates (MTA), which induce the activation of monocytes with a pro inflammatory phenotype. In the last decade, it has been established that activated platelets and other cells of the immune system, including monocytes, detached microvesicles (MV) from the membrane. It has been shown that MV are involved as messengers in the transport of biologically active lipids, cytokines, complement, and other molecules that can cause exacerbation of systemic inflammatory reactions. The presented review allows us to expand our knowledge about the cellular and molecular aspects of the interaction of monocytes/macrophages with microglial cells and platelets in the development of neuroinflammation and cognitive decline in the pathogenesis of mental diseases and in AD, and also helps in the search for specific biomarkers of the clinical severity of mental disorder in patients and the prospects for their response to treatment.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Timothy M. OʼShea ◽  
Alexander L. Wollenberg ◽  
Jae H. Kim ◽  
Yan Ao ◽  
Timothy J. Deming ◽  
...  

AbstractBiomaterials hold promise for therapeutic applications in the central nervous system (CNS). Little is known about molecular factors that determine CNS foreign body responses (FBRs) in vivo, or about how such responses influence biomaterial function. Here, we probed these factors in mice using a platform of injectable hydrogels readily modified to present interfaces with different physiochemical properties to host cells. We found that biomaterial FBRs mimic specialized multicellular CNS wound responses not present in peripheral tissues, which serve to isolate damaged neural tissue and restore barrier functions. We show that the nature and intensity of CNS FBRs are determined by definable properties that significantly influence hydrogel functions, including resorption and molecular delivery when injected into healthy brain or stroke injuries. Cationic interfaces elicit stromal cell infiltration, peripherally derived inflammation, neural damage and amyloid production. Nonionic and anionic formulations show minimal levels of these responses, which contributes to superior bioactive molecular delivery. Our results identify specific molecular mechanisms that drive FBRs in the CNS and have important implications for developing effective biomaterials for CNS applications.


2020 ◽  
Vol 16 (5) ◽  
pp. 652-658
Author(s):  
Jianze Wang ◽  
Zhiguo Lu ◽  
Jie Shen ◽  
Huan Peng ◽  
Tianlu Zhang ◽  
...  

Fragrances are extensively applied in food, daily chemicals, tobacco and medicine industries. However, too strong volatility of fragrances results in a fast release rate, thereby reducing the usage time of aromatherapy products. Although loading fragrances into nanomaterials is capable of slowing their rates of release, the encapsulation efficiency of traditional nanomaterials is very low, and the nanomaterials themselves are not stable. Herein, hollow mesoporous silica nanoparticles (hMSNs) were designed for encapsulation of eugenol and the nano-fragrance was named EG@hMSNs. The structure of hMSNs was stable and the encapsulation rate of eugenol reached 46.5%. Besides, EG@hMSNs could significantly slow the release rate of eugenol. Subsequently, the EG@hMSNs were testified that they had positive roles in stress relief by open field tests. The molecular mechanisms of these positive effects on the central nervous system were then explored. Furthermore, the preparation method of hMSCs was simple, and the preparation cost was low. Therefore, EG@hMSNs are expected to be industrially produced and have a great application prospect.


2020 ◽  
Vol 5 (2) ◽  

The accumulation of reliable data on the effects of cannabinoids is essential for understanding their possible beneficial effects on the central nervous system (CNS). Investigating individual substances along with the action of different combinations may show new possibilities for cannabinoids as neuroprotective agents. The data collected so far reveals the complexity of the mechanism of cannabinoids action on CNS, and even more complex and poorly understood are the effects when combined. Moreover, combining cannabinoids with different drugs and chemicals may lead to a decrease in beneficial effects. These characteristics of their action emphasize the complexity of the molecular mechanisms of neuroprotection and the lack of reliable information that may contribute to the safe and effective use of cannabinoids as medicines with valuable neuroprotective properties. The current brief review summarizes present data related to the protective effects of some cannabinoids on CNS and possible mechanisms involved in cannabinoid-mediated neuroprotection.


2017 ◽  
Vol 5 (1) ◽  
pp. 74-78
Author(s):  
V. Tsymbaliuk ◽  
V. Semenova ◽  
L. Pichkur ◽  
O. Velychko ◽  
D. Egorova

The review summarizes the current concepts of cell-tissue and molecular features of development of demyelinating processes in the central nervous system related to multiple sclerosis and its animal model – allergic encephalomyelitis. An analysis of recently published studies of this pathology, carried out with light and electron microscopy and immunohistochemical and molecular genetic methods, is given. New methodological approaches to the study of the pathomorhological aspects of demyelinating disorders allowed receiving in-depth understanding of the etiology and mechanisms of demyelination processes in the brain and spinal cord tissues at the cellular level and identifying the ways to develop effective modern methods of pathogenetic treatment of these diseases using cell therapy.


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