scholarly journals The L1-dependant and Pol III transcribed Alu retrotransposon, from its discovery to innate immunity

2021 ◽  
Vol 48 (3) ◽  
pp. 2775-2789
Author(s):  
Ludwig Stenz
Keyword(s):  
Human Genome ◽  
Viral Infections ◽  
De Novo ◽  
Current Knowledge ◽  
Innate Immune ◽  
De Novo Mutation ◽  
Neuronal Diversity ◽  
Alu Sequences ◽  
Pol Iii ◽  
The Brain

AbstractThe 300 bp dimeric repeats digestible by AluI were discovered in 1979. Since then, Alu were involved in the most fundamental epigenetic mechanisms, namely reprogramming, pluripotency, imprinting and mosaicism. These Alu encode a family of retrotransposons transcribed by the RNA Pol III machinery, notably when the cytosines that constitute their sequences are de-methylated. Then, Alu hijack the functions of ORF2 encoded by another transposons named L1 during reverse transcription and integration into new sites. That mechanism functions as a complex genetic parasite able to copy-paste Alu sequences. Doing that, Alu have modified even the size of the human genome, as well as of other primate genomes, during 65 million years of co-evolution. Actually, one germline retro-transposition still occurs each 20 births. Thus, Alu continue to modify our human genome nowadays and were implicated in de novo mutation causing diseases including deletions, duplications and rearrangements. Most recently, retrotransposons were found to trigger neuronal diversity by inducing mosaicism in the brain. Finally, boosted during viral infections, Alu clearly interact with the innate immune system. The purpose of that review is to give a condensed overview of all these major findings that concern the fascinating physiology of Alu from their discovery up to the current knowledge.

scholarly journals Canonical and Noncanonical Autophagy as Potential Targets for COVID-19

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1619 ◽  
Author(s):  
Melissa Bello-Perez ◽  
Isabel Sola ◽  
Beatriz Novoa ◽  
Daniel J. Klionsky ◽  
Alberto Falco
Keyword(s):  
Molecular Mechanisms ◽  
Viral Infections ◽  
Current Knowledge ◽  
Therapeutic Targets ◽  
Innate Immune ◽  
Interacting Proteins ◽  
Innate Immune Responses ◽  
Molecular Machinery ◽  
Autophagy Pathway

The SARS-CoV-2 pandemic necessitates a review of the molecular mechanisms underlying cellular infection by coronaviruses, in order to identify potential therapeutic targets against the associated new disease (COVID-19). Previous studies on its counterparts prove a complex and concomitant interaction between coronaviruses and autophagy. The precise manipulation of this pathway allows these viruses to exploit the autophagy molecular machinery while avoiding its protective apoptotic drift and cellular innate immune responses. In turn, the maneuverability margins of such hijacking appear to be so narrow that the modulation of the autophagy, regardless of whether using inducers or inhibitors (many of which are FDA-approved for the treatment of other diseases), is usually detrimental to viral replication, including SARS-CoV-2. Recent discoveries indicate that these interactions stretch into the still poorly explored noncanonical autophagy pathway, which might play a substantial role in coronavirus replication. Still, some potential therapeutic targets within this pathway, such as RAB9 and its interacting proteins, look promising considering current knowledge. Thus, the combinatory treatment of COVID-19 with drugs affecting both canonical and noncanonical autophagy pathways may be a turning point in the fight against this and other viral infections, which may also imply beneficial prospects of long-term protection.

scholarly journals The Innate Antiviral Response in Animals: An Evolutionary Perspective from Flagellates to Humans

Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 758 ◽  
Author(s):  
Karim Majzoub ◽  
Florian Wrensch ◽  
Thomas F. Baumert
Keyword(s):  
Viral Infections ◽  
Current Knowledge ◽  
Innate Immune ◽  
Model Organisms ◽  
Animal Cells ◽  
Molecular Systems ◽  
Host Interactions ◽  
Animal Hosts ◽  
Immune Pathways ◽  
Innate Antiviral Response

Animal cells have evolved dedicated molecular systems for sensing and delivering a coordinated response to viral threats. Our understanding of these pathways is almost entirely defined by studies in humans or model organisms like mice, fruit flies and worms. However, new genomic and functional data from organisms such as sponges, anemones and mollusks are helping redefine our understanding of these immune systems and their evolution. In this review, we will discuss our current knowledge of the innate immune pathways involved in sensing, signaling and inducing genes to counter viral infections in vertebrate animals. We will then focus on some central conserved players of this response including Toll-like receptors (TLRs), RIG-I-like receptors (RLRs) and cGAS-STING, attempting to put their evolution into perspective. To conclude, we will reflect on the arms race that exists between viruses and their animal hosts, illustrated by the dynamic evolution and diversification of innate immune pathways. These concepts are not only important to understand virus-host interactions in general but may also be relevant for the development of novel curative approaches against human disease.

scholarly journals Phagocytosis, Degranulation and Extracellular Traps Release by Neutrophils—The Current Knowledge, Pharmacological Modulation and Future Prospects

2021 ◽  
Vol 12 ◽  
Author(s):  
Barbara Gierlikowska ◽  
Albert Stachura ◽  
Wojciech Gierlikowski ◽  
Urszula Demkow
Keyword(s):  
Molecular Mechanisms ◽  
Viral Infections ◽  
Current Knowledge ◽  
Innate Immune ◽  
Therapeutic Approaches ◽  
Effector Functions ◽  
Pharmacological Modulation ◽  
Synthetic Drugs ◽  
Extracellular Traps

Neutrophils are crucial elements of innate immune system, which assure host defense via a range of effector functions, such as phagocytosis, degranulation, and NET formation. The latest literature clearly indicates that modulation of effector functions of neutrophils may affect the treatment efficacy. Pharmacological modulation may affect molecular mechanisms activating or suppressing phagocytosis, degranulation or NET formation. In this review, we describe the role of neutrophils in physiology and in the course of bacterial and viral infections, illustrating the versatility and plasticity of those cells. This review also focus on the action of plant extracts, plant-derived compounds and synthetic drugs on effector functions of neutrophils. These recent advances in the knowledge can help to devise novel therapeutic approaches via pharmacological modulation of the described processes.

scholarly journals Circulating Monocytes, Tissue Macrophages, and Malaria

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Nida Ozarslan ◽  
Joshua F. Robinson ◽  
Stephanie L. Gaw
Keyword(s):  
Current Knowledge ◽  
Cell Types ◽  
Innate Immune ◽  
Receptor Expression ◽  
Complex Life Cycle ◽  
Cytokine Release ◽  
Tissue Specific ◽  
Hofbauer Cells ◽  
The Relationship ◽  
The Brain

Malaria is a significant cause of global morbidity and mortality. The Plasmodium parasite has a complex life cycle with mosquito, liver, and blood stages. The blood stages can preferentially affect organs such as the brain and placenta. In each of these stages and organs, the parasite will encounter monocytes and tissue-specific macrophages—key cell types in the innate immune response. Interactions between the Plasmodium parasite and monocytes/macrophages lead to several changes at both cellular and molecular levels, such as cytokine release and receptor expression. In this review, we summarize current knowledge on the relationship between malaria and blood intervillous monocytes and tissue-specific macrophages of the liver (Kupffer cells), central nervous system (microglia), and placenta (maternal intervillous monocytes and fetal Hofbauer cells). We describe their potential roles in modulating outcomes from infection and areas for future investigation.

scholarly journals JAK-STAT Pathway: A Novel Target to Tackle Viral Infections

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2379
Author(s):  
Ifeanyi Jude Ezeonwumelu ◽  
Edurne Garcia-Vidal ◽  
Ester Ballana
Keyword(s):  
Viral Infections ◽  
Current Knowledge ◽  
Drug Repurposing ◽  
Innate Immune ◽  
Janus Kinase ◽  
Cellular Target ◽  
Proven Efficacy ◽  
Novel Target ◽  
Remarkable Progress ◽  
Stat Pathway

Modulation of the antiviral innate immune response has been proposed as a putative cellular target for the development of novel pan-viral therapeutic strategies. The Janus kinase–signal transducer and activator of transcription (JAK-STAT) pathway is especially relevant due to its essential role in the regulation of local and systemic inflammation in response to viral infections, being, therefore, a putative therapeutic target. Here, we review the extraordinary diversity of strategies that viruses have evolved to interfere with JAK-STAT signaling, stressing the relevance of this pathway as a putative antiviral target. Moreover, due to the recent remarkable progress on the development of novel JAK inhibitors (JAKi), the current knowledge on its efficacy against distinct viral infections is also discussed. JAKi have a proven efficacy against a broad spectrum of disorders and exhibit safety profiles comparable to biologics, therefore representing good candidates for drug repurposing strategies, including viral infections.

scholarly journals Leukoencephalopathia, demyelinating peripheral neuropathy and dural ectasia explained by a not formerly described de novo mutation in the SAMD9L gene, ends 27 years of investigations – A case report

2019 ◽  
Author(s):  
Sofia Thunström ◽  
Markus Axelsson
Keyword(s):  
Case Report ◽  
De Novo ◽  
Age Of Onset ◽  
De Novo Mutation ◽  
Missense Mutations ◽  
Case Presentation ◽  
Whole Exome ◽  
Demyelinating Peripheral Neuropathy ◽  
The Brain ◽  
Multiple Cysts

Abstract Background: Missense mutations in SAMD9L gene is associated with ataxia-pancytopenia syndrome (ATXPC), OMIM#159550. Common clinical features in these patients include neurological and hematological symptoms. The phenotype and age of onset is variable. Case presentation: In this case report whole exome sequencing (WES) revealed a not previously reported de novo variant c.2686T>G, p.(Phe896Val) in SAMD9L in a patient with widespread findings of slow developing pathology in the peripheral and central nervous system. The clinical picture was dominated by neurological symptoms, unlike previously described cases, and in addition dural ectasias and multiple cysts in the brain was observed using magnetic resonance imaging. Conclusions: This case underscores the effect of variable expressivity, i.e. different mutations in the same gene can cause different phenotypes.

scholarly journals Retrotransposons in the development and progression of amyotrophic lateral sclerosis

2018 ◽  
Vol 90 (3) ◽  
pp. 284-293 ◽  
Author(s):  
Abigail L Savage ◽  
Gerald G Schumann ◽  
Gerome Breen ◽  
Vivien J Bubb ◽  
Ammar Al-Chalabi ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Human Genome ◽  
De Novo ◽  
Current Knowledge ◽  
Human Diseases ◽  
Regulatory Domains ◽  
Novel Transcripts ◽  
Retrotransposon Activity ◽  
Lateral Sclerosis

Endogenous retrotransposon sequences constitute approximately 42% of the human genome, and mobilisation of retrotransposons has resulted in rearrangements, duplications, deletions, novel transcripts and the introduction of new regulatory domains throughout the human genome. Both germline and somatic de novo retrotransposition events have been involved in a range of human diseases, and there is emerging evidence for the modulation of retrotransposon activity during the development of specific diseases. Particularly, there is unequivocal consensus that endogenous retrotransposition can occur in neuronal lineages. This review addresses our current knowledge of the different mechanisms through which retrotransposons might influence the development of and predisposition to amyotrophic lateral sclerosis.

scholarly journals Back to the future: lessons from past viral infections and the link with Parkinsons disease

2021 ◽  
Author(s):  
Declan Mckernan ◽  
Eilís Dowd
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Viral Infections ◽  
Current Knowledge ◽  
Noticeable Increase ◽  
The Future ◽  
Potential Link ◽  
The Central Nervous System ◽  
The Brain

During the current COVID-19 pandemic, there has been noticeable increase in the reporting of neurological symptoms in patients. There is still uncertainty around the significance and long-term consequence of these symptoms. There are also many outstanding questions on whether the causative virus SARS-CoV2 can directly infect the central nervous system. Given the long association between viral infections with neurodegenerative conditions such as Parkinson’s disease, it seems timely to review this literature again in the context of the COVID-19 pandemic and to glean some useful information from studies on similar viruses. In this commentary, we will consider the current knowledge on viral infections in the brain. In addition, we review the link between viral infection and neurodegeneration in Parkinson’s disease, and review the recent literature on SARS infections, the potential link with Parkinson’s disease and the potential areas of study in the future

scholarly journals Leukoencephalopathia, demyelinating peripheral neuropathy and dural ectasia explained by a not formerly described de novo mutation in the SAMD9L gene, ends 27 years of investigations – A case report

2019 ◽  
Author(s):  
Sofia Thunström ◽  
Markus Axelsson
Keyword(s):  
Case Report ◽  
De Novo ◽  
Age Of Onset ◽  
De Novo Mutation ◽  
Missense Mutations ◽  
Case Presentation ◽  
Whole Exome ◽  
Demyelinating Peripheral Neuropathy ◽  
The Brain ◽  
Multiple Cysts

Abstract Background: Missense mutations in SAMD9L gene is associated with ataxia-pancytopenia syndrome (ATXPC), OMIM#159550. Common clinical features in these patients include neurological and hematological symptoms. The phenotype and age of onset is variable. Case presentation: In this case report whole exome sequencing (WES) revealed a not previously reported de novo variant c.2686T>G, p.(Phe896Val) in SAMD9L in a patient with widespread findings of slow developing pathology in the peripheral and central nervous system. The clinical picture was dominated by neurological symptoms, unlike previously described cases, and in addition dural ectasias and multiple cysts in the brain was observed using magnetic resonance imaging. Conclusions: This case underscores the effect of variable expressivity, i.e. different mutations in the same gene can cause different phenotypes.

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