scholarly journals mTORC2 combats cellular stress and potentiates immunity during viral infection

2020 ◽  
Author(s):  
Rahul K Suryawanshi ◽  
Chandrashekhar D. Patil ◽  
Alex Agelidis ◽  
Raghuram Koganti ◽  
Joshua M. Ames ◽  
...  
Keyword(s):  
Herpes Simplex ◽  
Brain Injuries ◽  
Viral Infections ◽  
Neuronal Cell Death ◽  
Mammalian Target Of Rapamycin ◽  
Memory Loss ◽  
Neuronal Cell ◽  
Therapeutic Window ◽  
Hsv 1

SummaryHerpes simplex virus type 1 (HSV-1) causes ocular and orofacial infections, which are generally well controlled by the host and nonlethal. In rare cases, HSV-1 causes encephalitis, which leads to permanent brain injuries, memory loss or even death. Host factors protect the organism from viral infections by activating the immune response. However, the factors that confer neuroprotection during viral encephalitis are unknown. Here we show that mammalian target of rapamycin complex 2 (mTORC2) is essential for the host survival of ocular HSV-1 infections in vivo. We found that the loss of mTORC2 causes systemic HSV-1 infection not only because of weak innate and adaptive immune responses but also due to increased ocular and neuronal cell death, which becomes lethal over time. Furthermore, we found that mTORC2 mediates cell survival channels through the inactivation of the proapoptotic factor FoxO3a. Our results demonstrate how mTORC2 potentiates host defenses against viral infections as well as implicating mTORC2 as a necessary host factor for survival. We anticipate our findings may help develop new therapeutic window for severe HSV-1 infections, such as herpes simplex encephalitis.

scholarly journals mTORC2 confers neuroprotection and potentiates immunity during virus infection

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rahul K. Suryawanshi ◽  
Chandrashekhar D. Patil ◽  
Alex Agelidis ◽  
Raghuram Koganti ◽  
Joshua M. Ames ◽  
...  
Keyword(s):  
Brain Injuries ◽  
Viral Infections ◽  
Neuronal Cell Death ◽  
Mammalian Target Of Rapamycin ◽  
Memory Loss ◽  
Neuronal Cell ◽  
Simplex Virus ◽  
Hsv 1

AbstractHerpes simplex virus type-1 (HSV-1) causes ocular and orofacial infections. In rare cases, HSV-1 can cause encephalitis, which leads to permanent brain injuries, memory loss or even death. Host factors protect humans from viral infections by activating the immune response. However, factors that confer neuroprotection during viral encephalitis are poorly understood. Here we show that mammalian target of rapamycin complex 2 (mTORC2) is essential for the survival of experimental animals after ocular HSV-1 infection in vivo. We find the loss of mTORC2 causes systemic HSV-1 infection due to defective innate and adaptive immune responses, and increased ocular and neuronal cell death that turns lethal for the infected mice. Furthermore, we find that mTORC2 mediated cell survival channels through the inactivation of the proapoptotic factor FoxO3a. Our results demonstrate how mTORC2 potentiates host defenses against viral infections and implicate mTORC2 as a necessary factor for survival of the infected host.

scholarly journals The ESCRT-Related ATPase Vps4 Is Modulated by Interferon during Herpes Simplex Virus 1 Infection

mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Jorge Ruben Cabrera ◽  
Richard Manivanh ◽  
Brian J. North ◽  
David A. Leib
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Viral Infections ◽  
Cell Types ◽  
Primary Neurons ◽  
Herpes Simplex Virus 1 ◽  
Escrt Machinery ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACTInterferons (IFNs) and autophagy are critical neuronal defenses against viral infection. IFNs alter neuronal autophagy by promoting the accumulation of IFN-dependent LC3-decorated autophagic structures, termed LC3 clusters. Here, we analyzed LC3 clusters in sensory ganglia following herpes simplex virus 1 (HSV-1) infection. In the vicinity of acutely infected neurons, antigen-negative neurons contained structures resembling accumulated autophagosomes and autolysosomes that culminated in LC3 clusters. This accumulation reflects a delayed completion of autophagy. Theendosomalsortingcomplexesrequired fortransport (ESCRT) machinery participates in autophagosome closure and is also required for HSV-1 replication. In this study, our results showed that HSV-1 infectionin vivoand in primary neurons caused a decrease in Vps4 (a key ESCRT pathway ATPase) RNA and protein with concomitant Stat1 activation and LC3 cluster induction. We also observed that IFNs were sufficient to decrease RNA and protein levels of Vps4 in primary neurons and in other cell types. The accumulation of ubiquitin was also observed at the LC3 cluster sites. Together, our results show that IFNs modulate the ESCRT machinery in neurons in response to HSV-1 infections.IMPORTANCENeurons rely on IFNs and autophagy as major defenses against viral infections, and HSV must overcome such defenses in order to replicate. In addition to controlling host immunity, HSV must also control host membranes in order to complete its life cycle. HSV uses the host ESCRT membrane scission machinery for viral production and transport. Here we present evidence of a new IFN-dependent mechanism used by the host to prevent ESCRT subversion by HSV. This activity also impacts the dynamics of autophagy, possibly explaining the presence of recently described LC3 clusters in the HSV-infected nervous system. The induced accumulations of ubiquitin observed in these LC3 clusters resembled those observed in certain neurodegenerative diseases, suggesting possible mechanistic parallels between these conditions.

scholarly journals The Potential Neuroprotective Role of Free and Encapsulated Quercetin Mediated by miRNA against Neurological Diseases

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1318
Author(s):  
Tarek Benameur ◽  
Raffaella Soleti ◽  
Chiara Porro
Keyword(s):  
Inflammatory Responses ◽  
Pathological Condition ◽  
Neurological Diseases ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
In Vivo Studies ◽  
Innovative Drug ◽  
Chronic Neuroinflammation

Chronic neuroinflammation is a pathological condition of numerous central nervous system (CNS) diseases such as Parkinson’s disease, Alzheimer’s disease, multiple sclerosis, amyotrophic lateral sclerosis and many others. Neuroinflammation is characterized by the microglia activation and concomitant production of pro-inflammatory cytokines leading to an increasing neuronal cell death. The decreased neuroinflammation could be obtained by using natural compounds, including flavonoids known to modulate the inflammatory responses. Among flavonoids, quercetin possess multiple pharmacological applications including anti-inflammatory, antitumoral, antiapoptotic and anti-thrombotic activities, widely demonstrated in both in vitro and in vivo studies. In this review, we describe the recent findings about the neuroprotective action of quercetin by acting with different mechanisms on the microglial cells of CNS. The ability of quercetin to influence microRNA expression represents an interesting skill in the regulation of inflammation, differentiation, proliferation, apoptosis and immune responses. Moreover, in order to enhance quercetin bioavailability and capacity to target the brain, we discuss an innovative drug delivery system. In summary, this review highlighted an important application of quercetin in the modulation of neuroinflammation and prevention of neurological disorders.

scholarly journals Herpes Simplex Virus Type 1 Evades the Effects of Antibody and Complement In Vivo

2002 ◽  
Vol 76 (18) ◽  
pp. 9232-9241 ◽  
Author(s):  
John M. Lubinski ◽  
Ming Jiang ◽  
Lauren Hook ◽  
Yueh Chang ◽  
Chad Sarver ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Type ◽  
Immune Evasion ◽  
Herpes Simplex Virus Type ◽  
Complement Components ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Herpes simplex virus type 1 (HSV-1) encodes a complement-interacting glycoprotein, gC, and an immunoglobulin G (IgG) Fc binding glycoprotein, gE, that mediate immune evasion by affecting multiple aspects of innate and acquired immunity, including interfering with complement components C1q, C3, C5, and properdin and blocking antibody-dependent cellular cytotoxicity. Previous studies evaluated the individual contributions of gC and gE to immune evasion. Experiments in a murine model that examines the combined effects of gC and gE immune evasion on pathogenesis are now reported. Virulence of wild-type HSV-1 is compared with mutant viruses defective in gC-mediated C3 binding, gE-mediated IgG Fc binding, or both immune evasion activities. Eliminating both activities greatly increased susceptibility of HSV-1 to antibody and complement neutralization in vitro and markedly reduced virulence in vivo as measured by disease scores, virus titers, and mortality. Studies with C3 knockout mice indicated that other activities attributed to these glycoproteins, such as gC-mediated virus attachment to heparan sulfate or gE-mediated cell-to-cell spread, do not account for the reduced virulence of mutant viruses. The results support the importance of gC and gE immune evasion in vivo and suggest potential new targets for prevention and treatment of HSV disease.

scholarly journals Structural Variability of the Herpes Simplex Virus 1 GenomeIn VitroandIn Vivo

2012 ◽  
Vol 86 (16) ◽  
pp. 8592-8601 ◽  
Author(s):  
Charlotte Mahiet ◽  
Ayla Ergani ◽  
Nicolas Huot ◽  
Nicolas Alende ◽  
Ahmed Azough ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Considerable Proportion ◽  
Inverted Repeats ◽  
Herpes Simplex Virus 1 ◽  
Cell Extracts ◽  
Simplex Virus ◽  
Hsv 1

Herpes simplex virus 1 (HSV-1) is a human pathogen that leads to recurrent facial-oral lesions. Its 152-kb genome is organized in two covalently linked segments, each composed of a unique sequence flanked by inverted repeats. Replication of the HSV-1 genome produces concatemeric molecules in which homologous recombination events occur between the inverted repeats. This mechanism leads to four genome isomers (termed P, IS, IL, and ILS) that differ in the relative orientations of their unique fragments. Molecular combing analysis was performed on DNA extracted from viral particles and BSR, Vero, COS-7, and Neuro-2a cells infected with either strain SC16 or KOS of HSV-1, as well as from tissues of experimentally infected mice. Using fluorescence hybridization, isomers were repeatedly detected and distinguished and were accompanied by a large proportion of noncanonical forms (40%). In both cell and viral-particle extracts, the distributions of the four isomers were statistically equivalent, except for strain KOS grown in Vero and Neuro-2a cells, in which P and IS isomers were significantly overrepresented. In infected cell extracts, concatemeric molecules as long as 10 genome equivalents were detected, among which, strikingly, the isomer distributions were equivalent, suggesting that any such imbalance may occur during encapsidation.In vivo, for strain KOS-infected trigeminal ganglia, an unbalanced distribution distinct from the onein vitrowas observed, along with a considerable proportion of noncanonical assortment.

scholarly journals Functional IRF3 deficiency in a patient with herpes simplex encephalitis

2015 ◽  
Vol 212 (9) ◽  
pp. 1371-1379 ◽  
Author(s):  
Line Lykke Andersen ◽  
Nanna Mørk ◽  
Line S. Reinert ◽  
Emil Kofod-Olsen ◽  
Ryo Narita ◽  
...  
Keyword(s):  
Herpes Simplex ◽  
Autosomal Dominant ◽  
Viral Infections ◽  
Herpes Simplex Encephalitis ◽  
Type I ◽  
Toll Like Receptor ◽  
Loss Of Function ◽  
Impaired Ability ◽  
Increased Susceptibility ◽  
Hsv 1

Herpes simplex encephalitis (HSE) in children has previously been linked to defects in type I interferon (IFN) production downstream of Toll-like receptor 3. Here, we describe a novel genetic etiology of HSE by identifying a heterozygous loss-of-function mutation in the IFN regulatory factor 3 (IRF3) gene, leading to autosomal dominant (AD) IRF3 deficiency by haploinsufficiency, in an adolescent female patient with HSE. IRF3 is activated by most pattern recognition receptors recognizing viral infections and plays an essential role in induction of type I IFN. The identified IRF3 R285Q amino acid substitution results in impaired IFN responses to HSV-1 infection and particularly impairs signaling through the TLR3–TRIF pathway. In addition, the R285Q mutant of IRF3 fails to become phosphorylated at S386 and undergo dimerization, and thus has impaired ability to activate transcription. Finally, transduction with WT IRF3 rescues the ability of patient fibroblasts to express IFN in response to HSV-1 infection. The identification of IRF3 deficiency in HSE provides the first description of a defect in an IFN-regulating transcription factor conferring increased susceptibility to a viral infection in the CNS in humans.

scholarly journals Global Reprogramming of Apoptosis-Related Genes during Brain Development

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2901
Author(s):  
Wei Jiang ◽  
Liang Chen ◽  
Sika Zheng
Keyword(s):  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Term Survival ◽  
Apoptosis Pathway ◽  
Apoptotic Gene ◽  
Histone 3 ◽  
Effector Caspase ◽  
Maturation Stages ◽  
Apoptotic Genes

To enable long-term survival, mammalian adult neurons exhibit unique apoptosis competence. Questions remain as to whether and how neurons globally reprogram the expression of apoptotic genes during development. We systematically examined the in vivo expression of 1923 apoptosis-related genes and associated histone modifications at eight developmental ages of mouse brains. Most apoptotic genes displayed consistent temporal patterns across the forebrain, midbrain, and hindbrain, suggesting ubiquitous robust developmental reprogramming. Although both anti- and pro-apoptotic genes can be up- or downregulated, half the regulatory events in the classical apoptosis pathway are downregulation of pro-apoptotic genes. Reduced expression in initiator caspases, apoptosome, and pro-apoptotic Bcl-2 family members restrains effector caspase activation and attenuates neuronal apoptosis. The developmental downregulation of apoptotic genes is attributed to decreasing histone-3-lysine-4-trimethylation (H3K4me3) signals at promoters, where histone-3-lysine-27-trimethylation (H3K27me3) rarely changes. By contrast, repressive H3K27me3 marks are lost in the upregulated gene groups, for which developmental H3K4me3 changes are not predictive. Hence, developing brains remove epigenetic H3K4me3 and H3K27me3 marks on different apoptotic gene groups, contributing to their downregulation and upregulation, respectively. As such, neurons drastically alter global apoptotic gene expression during development to transform apoptosis controls. Research into neuronal cell death should consider maturation stages as a biological variable.

scholarly journals Modulating the Pro-apoptotic Activity of Cytochrome c at a Biomimetic Electrified Interface

2021 ◽  
Author(s):  
Alonso Gamero-Quijano ◽  
Shayon Bhattacharya ◽  
Pierre-André Cazade ◽  
Andrés F. Molina-Osorio ◽  
Cillian Beecher ◽  
...  
Keyword(s):  
Cell Death ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Inner Mitochondrial Membrane ◽  
Foetal Development ◽  
Drug Molecules ◽  
Electrified Interface ◽  
Conformational Plasticity ◽  
Apoptotic Activity

<p>Programmed cell death <i>via</i> apoptosis is a natural defence against excessive cell division, crucial at all stages of life from foetal development to maintenance of homeostasis and elimination of precancerous and senescent cells. Here we demonstrate an electrified liquid bio-interface that replicates the molecular machinery of the inner mitochondrial membrane at the onset of apoptosis. By mimicking <i>in vivo</i> cytochrome <i>c</i> (Cyt <i>c</i>) interactions with cell membranes, our platform allows us to modulate the conformational plasticity of the protein by simply varying the electrochemical environment at an aqueous|organic interface. As proof-of-concept, we use our electrified liquid bio-interface to identify drug molecules that can potentially downregulate Cyt <i>c</i> and protect against uncontrolled neuronal cell death in Alzheimer’s disease and other neurodegenerative disorders.</p>

scholarly journals In vivo regulation of cell death by embryonic (pro)insulin and the insulin receptor during early retinal neurogenesis

Development ◽  
2000 ◽  
Vol 127 (8) ◽  
pp. 1641-1649
Author(s):  
B. Diaz ◽  
J. Serna ◽  
F. De Pablo ◽  
E.J. de la Rosa
Keyword(s):  
Cell Death ◽  
Embryonic Development ◽  
Insulin Receptor ◽  
Neural Development ◽  
Developmental Process ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
In Ovo ◽  
Retinal Neurogenesis

Programmed cell death is an established developmental process in the nervous system. Whereas the regulation and the developmental role of neuronal cell death have been widely demonstrated, the relevance of cell death during early neurogenesis, the cells affected and the identity of regulatory local growth factors remain poorly characterized. We have previously described specific in vivo patterns of apoptosis during early retinal neurogenesis, and that exogenous insulin acts as survival factor (Diaz, B., Pimentel, B., De Pablo, F. and de la Rosa, E. J. (1999) Eur. J. Neurosci. 11, 1624–1632). Proinsulin mRNA was found to be expressed broadly in the early embryonic chick retina, and decreased later between days 6 and 8 of embryonic development, when there was increased expression of insulin-like growth factor I mRNA, absent or very scarce at earlier stages. Consequently, we studied whether proinsulin and/or insulin ((pro)insulin) action in prevention of cell death has physiological relevance during early neural development. In ovo treatment at day 2 of embryonic development with specific antibodies against (pro)insulin or the insulin receptor induced apoptosis in the neuroretina. The distribution of apoptotic cells two days after the blockade was similar to naturally occurring cell death, as visualized by TdT-mediated dUTP nick end labeling. The apoptosis induced by the insulin receptor blockade preferentially affected to the Islet1/2 positive cells, that is, the differentiated retinal ganglion cells. In parallel, the insulin survival effect on cultured retinas correlated with the activation of Akt to a greater extent than with the activation of MAP kinase. These results suggest that the physiological cell death occurring in early stages of retinal development is regulated by locally produced (pro)insulin through the activation of the Akt survival pathway.

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