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1.
EMBO J ; 41(23): e111289, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36221902

RESUMO

The NOD1/2-RIPK2 is a key cytosolic signaling complex that activates NF-κB pro-inflammatory response against invading pathogens. However, uncontrolled NF-κB signaling can cause tissue damage leading to chronic diseases. The mechanisms by which the NODs-RIPK2-NF-κB innate immune axis is activated and resolved remain poorly understood. Here, we demonstrate that bacterial infection induces the formation of endogenous RIPK2 oligomers (RIPosomes) that are self-assembling entities that coat the bacteria to induce NF-κB response. Next, we show that autophagy proteins IRGM and p62/SQSTM1 physically interact with NOD1/2, RIPK2 and RIPosomes to promote their selective autophagy and limit NF-κB activation. IRGM suppresses RIPK2-dependent pro-inflammatory programs induced by Shigella and Salmonella. Consistently, the therapeutic inhibition of RIPK2 ameliorates Shigella infection- and DSS-induced gut inflammation in Irgm1 KO mice. This study identifies a unique mechanism where the innate immune proteins and autophagy machinery are recruited together to the bacteria for defense as well as for maintaining immune homeostasis.


Assuntos
Infecções Bacterianas , NF-kappa B , Camundongos , Animais , NF-kappa B/metabolismo , Camundongos Endogâmicos NOD , Autofagia , Imunidade Inata , Homeostase
2.
Neurochem Res ; 48(1): 82-95, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36001190

RESUMO

Neuropsychiatric upshots following chronic exposure to unpredictable adverse stressors have been well documented in the literature. Considering the significant impact of chronic unpredictable stress (CUS), the literature is elusive regarding the neuroprotective efficacy of taurine against CUS-induced oxidative stress and chromatin condensation in the zebrafish brain. In this study, to ameliorate CUS-persuaded neurological outcomes, waterborne treatment of taurine as a prophylactic intervention was undertaken. Further, our approach also focused on the gross neurobehavioral response of zebrafish, oxidative stress indices and neuromorphology of the zebrafish brain following CUS exposure with taurine treatment. Because taurine provides significant neuroprotection against oxidative insult, the cytosolic level of monoamine oxidase (MAO) in the zebrafish brain following CUS exposure is worth investigating. Further, as heightened MAO activity is associated with augmented oxidative and chromatin condensation, the focus of this study was on whether taurine provides neuroprotection by downregulating MAO levels in the brain. Our findings show that CUS-persuaded altered neurobehavioral response was significantly rescued by taurine. Moreover, our findings firmly support the hypothesis that taurine acts as a radical neuroprotector by restoring glutathione biosynthesis in the zebrafish brain subsequent to CUS exposure. Additionally, the rising level of brain MAO following chronic exposure to CUS is ameliorated by taurine treatment. These findings strongly advocate the role of taurine as a natural MAO inhibitor through the neuroprotection it provides against CUS-instigated oxidative stress in zebrafish. However, the fundamental neuroprotective mechanism of such natural compounds needs to be elucidated to determine their neuroprotective efficacy against stress regimens.


Assuntos
Neuroproteção , Peixe-Zebra , Animais , Taurina/farmacologia , Encéfalo , Monoaminoxidase
3.
EMBO Rep ; 22(11): e52948, 2021 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-34467632

RESUMO

The type I interferon (IFN) response is the major host arsenal against invading viruses. IRGM is a negative regulator of IFN responses under basal conditions. However, the role of human IRGM during viral infection has remained unclear. In this study, we show that IRGM expression is increased upon viral infection. IFN responses induced by viral PAMPs are negatively regulated by IRGM. Conversely, IRGM depletion results in a robust induction of key viral restriction factors including IFITMs, APOBECs, SAMHD1, tetherin, viperin, and HERC5/6. Additionally, antiviral processes such as MHC-I antigen presentation and stress granule signaling are enhanced in IRGM-deficient cells, indicating a robust cell-intrinsic antiviral immune state. Consistently, IRGM-depleted cells are resistant to the infection with seven viruses from five different families, including Togaviridae, Herpesviridae, Flaviviverdae, Rhabdoviridae, and Coronaviridae. Moreover, we show that Irgm1 knockout mice are highly resistant to chikungunya virus (CHIKV) infection. Altogether, our work highlights IRGM as a broad therapeutic target to promote defense against a large number of human viruses, including SARS-CoV-2, CHIKV, and Zika virus.


Assuntos
Proteínas de Ligação ao GTP/antagonistas & inibidores , Viroses/imunologia , Animais , Antivirais/farmacologia , Humanos , Camundongos , Replicação Viral
4.
Fish Physiol Biochem ; 49(3): 501-514, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37131059

RESUMO

The contamination of life-sustaining environments with synthetic pollutants such as plastic-derived compounds has increased at an alarming rate in recent decades. Among such contaminants, di-2-ethylhexyl phthalate (DEHP) is an extensively used compound in plastics and plastic products to make them flexible. DEHP causes several adverse effects such as reproductive toxicity leading to infertility, miscarriage and litter size reduction, disruption of the thyroid endocrine system, oxidative stress, neurodevelopmental defect and cognitive impairment. An aquatic environment is a fragile site, where the accumulation of DEHP poses a significant threat to living organisms. In this context, the present study focused on whether the neurobehavioural transformation following exposure to DEHP is an outcome of augmented oxidative stress and neuromorphological alteration in the zebrafish brain. Our preliminary findings advocate that DEHP acts as a typical neurotoxicant in inducing neurobehavioural transformation in zebrafish. Furthermore, our study also supports the idea that DEHP itself acts as a potent neurotoxicant by altering the glutathione biosynthetic pathway through the induction of oxidative stress in the zebrafish brain. Similarly, our findings also link the abovementioned neurobehavioural transformation and oxidative stress with augmented neuronal pyknosis and chromatin condensation in the periventricular grey zone of the zebrafish brain following chronic exposure to DEHP. Therefore, the overall conclusion of the present study advocates the potential role of DEHP in inducing neuropathological manifestation in the zebrafish brain. Future research directed towards elucidating the neuroprotective efficacy of natural compounds against DEHP-induced neurotoxicity may provide a new line of intervention.


Assuntos
Dietilexilftalato , Peixe-Zebra , Animais , Peixe-Zebra/fisiologia , Dietilexilftalato/toxicidade , Estresse Oxidativo , Encéfalo , Plásticos/farmacologia , Glutationa
5.
EMBO Rep ; 21(9): e50051, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32715615

RESUMO

Activation of the type 1 interferon response is extensively connected to the pathogenesis of autoimmune diseases. Loss of function of Immunity Related GTPase M (IRGM) has also been associated to several autoimmune diseases, but its mechanism of action is unknown. Here, we found that IRGM is a master negative regulator of the interferon response. Several nucleic acid-sensing pathways leading to interferon-stimulated gene expression are highly activated in IRGM knockout mice and human cells. Mechanistically, we show that IRGM interacts with nucleic acid sensor proteins, including cGAS and RIG-I, and mediates their p62-dependent autophagic degradation to restrain interferon signaling. Further, IRGM deficiency results in defective mitophagy leading to the accumulation of defunct leaky mitochondria that release cytosolic DAMPs and mtROS. Hence, IRGM deficiency increases not only the levels of the sensors, but also those of the stimuli that trigger the activation of the cGAS-STING and RIG-I-MAVS signaling axes, leading to robust induction of IFN responses. Taken together, this study defines the molecular mechanisms by which IRGM maintains interferon homeostasis and protects from autoimmune diseases.


Assuntos
Doenças Autoimunes , Autoimunidade , Animais , Doenças Autoimunes/genética , Autoimunidade/genética , Autofagia , Camundongos , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Transdução de Sinais
6.
Arch Microbiol ; 203(6): 2895-2910, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33763767

RESUMO

Increasing incidences of neurological disorders, such as Parkinson's disease (PD), multiple sclerosis (MS), Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS) are being reported, but an insight into their pathology remains elusive. Findings have suggested that gut microbiota play a major role in regulating brain functions through the gut-brain axis. A unique bidirectional communication between gut microbiota and maintenance of brain health could play a pivotal role in regulating incidences of neurodegenerative diseases. Contrarily, the present life style with changing food habits and disturbed circadian rhythm may contribute to gut homeostatic imbalance and dysbiosis leading to progression of several neurological disorders. Therefore, dysbiosis, as a primary factor behind intestinal disorders, may also augment inflammation, intestinal and blood-brain barrier permeability through microbiota-gut-brain axis. This review primarily focuses on the gut-brain axis functions, specific gut microbial population, metabolites produced by gut microbiota, their role in regulating various metabolic processes and role of gut microbiota towards development of neurodegenerative diseases. However, several studies have reported a decrease in abundance of a specific gut microbial population and a corresponding increase in other microbial family, with few findings revealing some contradictions. Reports also showed that colonization of gut microbiota isolated from patients suffering from neurodegenerative disease leads to the development of enhance pathological outcomes in animal models. Hence, a systematic understanding of the dominant role of specific gut microbiome towards development of different neurodegenerative diseases could possibly provide novel insight into the use of probiotics and microbial transplantation as a substitute approach for treating/preventing such health maladies.


Assuntos
Encéfalo/fisiologia , Microbioma Gastrointestinal/fisiologia , Doenças Neurodegenerativas/etiologia , Animais , Humanos
7.
Environ Toxicol ; 36(11): 2342-2353, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34403186

RESUMO

Bisphenol A (BPA) has been documented as a mediator for a number of health effects, including inflammation, oxidative stress, carcinogenicity, and mood dysfunction. The literature on the role of BPA in inducing altered neurobehavioral response and brain morphology and plausible neuroprotective role of taurine against BPA induced oxidative stress mediated neurotoxicity is limited. Therefore, the present experimental paradigm was set for 21 days to expound the neuroprotective efficacy of taurine against BPA-induced neurotoxicity in zebrafish (Danio rerio) following waterborne exposure. Neurobehavioral studies were conducted by light-dark preference test (LDPT) and novel tank diving test (NTDT). To validate that the neuroprotective efficacy of taurine against BPA-induced neurotoxicity is associated with the modulation of the antioxidant defense system, we have conducted biochemical studies in zebrafish brain. Changes in brain morphology leading to neurobehavioral variations following co-supplementation of BPA and taurine were evaluated by Hoechst staining and cresyl violet staining (CVS) in periventricular gray zone (PGZ) of zebrafish brain. Our findings show that taurine co-supplementation significantly improved the BPA-induced altered scototaxis and explorative behavior of zebrafish. Further, BPA-induced augmented oxidative stress was considerably ameliorated by taurine co-supplementation. Subsequently, our observation also points toward the neuroprotective role of taurine against BPA-induced neuronal pyknosis and chromatin condensation in PGZ of zebrafish brain. In a nutshell, the findings of the current study show the neuroprotective efficacy of taurine against BPA-induced oxidative stress-mediated neurotoxicity. Elucidation of the underlying signaling mechanism of taurine-mediated neuroprotection would provide novel strategies for the prevention/treatment of BPA-persuaded serious neurological consequences.


Assuntos
Taurina , Peixe-Zebra , Animais , Compostos Benzidrílicos/toxicidade , Neuroproteção , Estresse Oxidativo , Fenóis , Taurina/farmacologia
8.
Scand J Gastroenterol ; 52(12): 1315-1319, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28906161

RESUMO

Increased environmental temperature exerts a visible impact on an individual's physiology. At the onset of heat stress, there is an increase in core body temperature which triggers peripheral vasodilation and sweating in an effort to dissipate the elevated body heat. The increase in peripheral circulation however reduces blood flow to the internal organs which are thus adversely affected. In particular, the gastrointestinal (GI) tract gets adversely affected during hyperthermia resulting in loosening of the tight junctions (TJs) that finally leads to higher intestinal permeability. At the cellular level, elevated levels of heat shock proteins (HSPs) induced in response to heat stress mediated cytoprotection by maintaining proper protein folding, releasing survival signals and preserving cytoskeleton integrity. Recent studies have indicated that HSPs play a crucial role in maintaining the localization of TJ proteins. Dietary supplements have also shown to have a positive effect on the maintenance of intestinal TJs. Therefore, it becomes imperative to understand the cellular, molecular and physiological alterations in response to heat stress in GI tract. In the present report, the effect of thermal stress on GI tract has been summarized. Specific role of HSPs along with mitogen activated protein (MAP) kinase signaling pathway in response to hyperthermia has also been discussed.


Assuntos
Febre/fisiopatologia , Trato Gastrointestinal/fisiopatologia , Proteínas de Choque Térmico/fisiologia , Junções Íntimas/fisiologia , Animais , Humanos , Sistema de Sinalização das MAP Quinases/fisiologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-38944366

RESUMO

Di-2-ethylhexyl phthalate (DEHP) is the most commonly preferred synthetic organic chemical in plastics and its products for making them ductile, flexible and durable. As DEHP is not chemically bound to the macromolecular polymer of plastics, it can be easily leached out to accumulate in food and environment. Our recent report advocated that exposure to DEHP significantly transformed the innate bottom-dwelling and scototaxis behaviour of zebrafish. Our present study aimed to understand the possible role of DEHP exposure pertaining towards the development of aggressive behaviour and its association with amplified monoamine oxidase activity and neurodegeneration in the zebrafish brain. As heightened monoamine oxidase (MAO) is linked with genesis of aggressive behaviour, our observation also coincides with DEHP-persuaded aggressive neurobehavioral transformation in zebrafish. Our preliminary findings also showed that DEHP epitomized as a prime factor in transforming native explorative behaviour and genesis of aggressive behaviour through oxidative stress induction and changes in the neuromorphology in the periventricular grey zone (PGZ) of the zebrafish brain. With the finding demarcating towards heightened chromatin condensation in the PGZ of zebrafish brain, our further observation by immunohistochemistry showed a profound augmentation in apoptotic cell death marker cleaved caspase 3 (CC3) expression following exposure to DEHP. Our further observation by immunoblotting study also demarcated a temporal augmentation in CC3 and tyrosine hydroxylase expression in the zebrafish brain. Therefore, the gross findings of the present study delineate the idea that chronic exposure to DEHP is associated with MAO-instigated aggressive neurobehavioral transformation and neurodegeneration in the zebrafish brain.

10.
Environ Toxicol Pharmacol ; 97: 104027, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36462733

RESUMO

As bisphenol A (BPA) effortlessly crosses the blood-brain barrier, its serious impacts on the neuronal microenvironment towards precocious induction of oxidative stress and neuromorphological alteration can't be ignored. Incidentally, a symmetric study establishing the possible link of transformed neurobehavior with heightened monoamine oxidase (MAO) activity and neuromorphological alteration in zebrafish brain subsequent to BPA-exposure is limiting in the literature. The study was conducted to delineate the role of BPA towards the genesis of aggressive behaviour in zebrafish and its correlation with brain MAO activity. Mirror biting test and open field test were conducted to evaluate the aggressive and explorative behaviour respectively. Biochemical studies were performed to delineate the modulation of the antioxidant defence system. Cresyl violet staining and Hoechst staining in the periventricular grey zone of the zebrafish brain were conducted to evaluate neuronal pyknosis and chromatin condensation. Our study showed that BPA exposure is associated with the genesis of aggressive neurobehavioral response. Moreover, the brain MAO activity, oxidative stress and chromatin condensation were increased with increase in exposure duration. The results of the present study gave conclusive evidence that BPA act as a potent neurotoxicant in transforming the native neurobehavioral response of zebrafish through heightened oxidative stress, MAO activity and altered neuromorphology.


Assuntos
Encéfalo , Peixe-Zebra , Animais , Peixe-Zebra/metabolismo , Encéfalo/metabolismo , Antioxidantes , Compostos Benzidrílicos/toxicidade , Monoaminoxidase/metabolismo
11.
Cell Rep ; 42(11): 113275, 2023 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-37874678

RESUMO

Type I interferon (IFN-I) response is the first line of host defense against invading viruses. In the absence of definite mouse models, the role of IFN-I in SARS-CoV-2 infection remains perplexing. Here, we develop two mouse models, one with constitutively high IFN-I response (hACE2; Irgm1-/-) and the other with dampened IFN-I response (hACE2; Ifnar1-/-), to comprehend the role of IFN-I response. We report that hACE2; Irgm1-/- mice are resistant to lethal SARS-CoV-2 infection. In contrast, a severe SARS-CoV-2 infection along with immune cell infiltration, cytokine storm, and enhanced pathology is observed in the lungs and brain of hACE2; Ifnar1-/- mice. The hACE2; Irgm1-/-Ifnar1-/- double-knockout mice display loss of the protective phenotype observed in hACE2; Irgm1-/- mice, suggesting that heightened IFN-I response accounts for the observed immunity. Taking the results together, we demonstrate that IFN-I protects from lethal SARS-CoV-2 infection, and Irgm1 (IRGM) could be an excellent therapeutic target against SARS-CoV-2.


Assuntos
COVID-19 , Interferon Tipo I , Camundongos , Animais , Camundongos Transgênicos , SARS-CoV-2 , Camundongos Knockout , Anticorpos , Modelos Animais de Doenças , Pulmão
12.
Behav Brain Res ; 418: 113672, 2022 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-34785260

RESUMO

Modelling of chronic stress conditions in experimental animals and its neuropsychiatric outcomes has been well documented in literature. Zebrafish (Danio rerio) by exhibiting significant genetic and epidemiological similarities with human beings, has now emerged as a promising animal model of translational research. In this line, risk assessment following exposure to chronic unpredictable stress (CUS) towards neurobehavioral response and neuromorphology of sensitive brain region in zebrafish is the prime objective of the present study. With the existing knowledge on CUS in affecting diverse neurobehavioral aspects, we were primarily interested in whether this neurobehavioral transformation is an outcome of altered glutathione biosynthesis in zebrafish. We were also concerned about whether the precocious neurobehavioral transformation has been linked to altered neuromorphology in the periventricular grey zone (PGZ) of the zebrafish brain. Our basic findings showed that CUS itself represented as a universal factor in altering native bottom-dwelling and scototaxis behaviour of zebrafish. Our findings also backing the argument that CUS itself represented a collective stress regimen by altering the brain glutathione biosynthesis in zebrafish. Correspondingly, a temporal transformation in CUS instigated augmentation in neuronal pyknosis and chromatin condensation were observed in PGZ of the zebrafish brain. Collectively, these findings designate that CUS induced temporal neurobehavioral transformation is an outcome of augmented oxidative stress and neuromorphological alteration in the zebrafish brain. However, the underlying mechanism of such neuropathological manifestation associated with CUS might provide novel insight towards the development of prophylactic/therapeutic intervention to counter such co-morbid behavioral alteration.


Assuntos
Comportamento Animal , Encéfalo/metabolismo , Glutationa/metabolismo , Estresse Psicológico/metabolismo , Peixe-Zebra/metabolismo , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Modelos Animais de Doenças , Humanos , Locomoção , Masculino , Estresse Oxidativo
13.
FEBS J ; 289(14): 4112-4131, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34826185

RESUMO

Extensive crosstalk exists between autophagy and innate immune signalling pathways. The stimuli that induce pattern recognition receptor (PRR)-mediated innate immune signalling pathways, also upregulate autophagy. The purpose of this increased autophagy is to eliminate the stimuli and/or suppress the inflammatory pathways by targeted degradation of PRRs or intermediary proteins (termed 'inflammophagy'). By executing these functions, autophagy dampens excess inflammation triggered by the innate immune signalling pathways. Thus, autophagy helps in the maintenance of the body's innate immune homeostasis to protect from inflammatory and autoimmune diseases. Many autophagy-dependent mechanisms that could control innate immune signalling have been studied over the last few years. However, still, the understanding is incomplete, and studies that are more systematic should be undertaken to delineate the mechanisms of inflammophagy. Here, we discuss the available knowledge of crosstalk between autophagy and PRR signalling pathways.


Assuntos
Autofagia , Imunidade Inata , Homeostase , Humanos , Inflamação , Transdução de Sinais
14.
Behav Brain Res ; 396: 112895, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32890597

RESUMO

Heat exposure is an environmental stress that causes diverse heat related pathophysiological changes under extreme conditions. The brain including hippocampal region which is associated with learning and memory is significantly affected by heat stress resulting in memory impairment. However, the effect of heat on the spatial memory remains unclear. The present study aimed to explore the effect of heat stress on hippocampus and spatial memory in rats. Rat model of acute heat stress was used which was divided into two groups, viz. moderate heat stress (MHS) and severe heat stress (SHS). Redox parameters evaluation revealed that MHS and SHS exposure markedly increase the production of malondialdehyde (MDA), oxidised glutathione (GSSG), reactive oxidative species (ROS), protein oxidation level and decrease the reduced glutathione (GSH) levels in the hippocampal tissue. Furthermore, Cresyl Violet (CV) staining of hippocampal region showed higher pyknosis in rats exposed to SHS. Pronounced increase of caspase3 expression and Fluoro Jade-C (FJ-C) positive cells were observed in SHS resulting in neuronal injury and apoptosis in CA3 region of hippocampus culminating in spatial memory deficit. Our data also suggest that heat stress induces phospho Extracellular signal-regulated kinases (pERK)1/2 activation induced by Brain-derived neurotrophic factor (BDNF) leading to further activation of phospho cAMP-response element binding protein (pCREB) under MHS. However, during SHS, BDNF and pCREB expression were completely dysregulated and not sufficient to rescue cognitive decline in rats. In conclusion, SHS induces pathological alterations that include oxidative damage and apoptosis of hippocampal neurons, disturbing BDNF/ERK1/2/CREB axis that may affect spatial memory.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Região CA3 Hipocampal , Proteína de Ligação a CREB/metabolismo , Resposta ao Choque Térmico/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Transtornos da Memória , Estresse Oxidativo/fisiologia , Memória Espacial/fisiologia , Animais , Comportamento Animal/fisiologia , Região CA3 Hipocampal/metabolismo , Região CA3 Hipocampal/patologia , Região CA3 Hipocampal/fisiopatologia , Modelos Animais de Doenças , Masculino , Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/etiologia , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Transtornos da Memória/fisiopatologia , Ratos , Ratos Sprague-Dawley
15.
Autophagy ; 17(2): 578-580, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32813580

RESUMO

IRGM is a genetic risk factor for several autoimmune diseases. However, the mechanism of IRGM-mediated protection in autoimmunity remains undetermined. The abnormal activation of type I interferon (IFN) response is one of the significant factors in the pathogenesis of several autoimmune diseases. In our recent study, we showed that IRGM is a master suppressor of the interferon response. We found that the depletion of IRGM results in constitutively activated CGAS-STING1, DDX58/RIG-I-MAVS, and TLR3-TICAM1/TRIF signaling pathways resulting in upregulation of almost all IFN-responsive genes. Mechanistically, IRGM utilizes a two-pronged mechanism to suppress the interferon response. First, it mediates SQSTM1/p62-dependent selective macroautophagy/autophagy of nucleic acid sensor proteins, including CGAS, DDX58/RIG-I, and TLR3. Second, it facilitates the removal of defective mitochondria by mitophagy and avoids a buildup of mito-ROS and mito-damage/danger-associated molecular patterns (DAMPs). Thus, IRGM deficiency results in increased nucleic acid sensors and DAMPs engaging a vicious cycle of aberrant activation of IFN response that is known to occur in systemic autoimmune-like conditions.


Assuntos
Autoimunidade/imunologia , Autofagia/fisiologia , Proteínas de Ligação ao GTP/metabolismo , Mitocôndrias/metabolismo , Doenças Autoimunes/genética , Doenças Autoimunes/metabolismo , Doenças Autoimunes/patologia , Humanos , Transdução de Sinais/fisiologia
16.
Autophagy ; 15(5): 924-926, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30806139

RESUMO

The formation of protein aggregates is linked to several diseases collectively called proteinopathies. The mechanisms and the molecular players that control the turnover of protein aggregates are not well defined. We recently showed that TRIM16 acts as a key regulatory protein to control the biogenesis and degradation of protein aggregates. We show that TRIM16 interacts with, enhances K63-linked ubiquitination of, and stabilizes NFE2L2/NRF2 leading to its activation. The activated NFE2L2 upregulates the SQSTM1/p62 and ubiquitin pathway proteins, which interact with and ubiquitinate the misfolded proteins resulting in protein aggregate formation. TRIM16 is physically present around the protein aggregates and acts as a scaffold protein to recruit SQSTM1 and macroautophagy/autophagy initiation proteins for sequestration of the protein aggregates within autophagosomes, leading to their degradation. Hence, TRIM16 utilizes a two-pronged approach to safely dispose of the stress-induced misfolded proteins and protein aggregates, and protect cells from oxidative and proteotoxic stresses. This study could provide a framework for understanding the mechanisms of protein aggregate formation in neurodegeneration. The enhancement of TRIM16 activity could be a beneficial therapeutic approach in proteinopathies. On the flip side, cancer cells appear to hijack this machinery for their survival under stress conditions; hence, depleting TRIM16 could be a beneficial therapeutic strategy for treating cancer.


Assuntos
Autofagia , Agregados Proteicos , Proteína Sequestossoma-1 , Proteínas Ubiquitinadas , Ubiquitinação
17.
Autophagy ; 15(9): 1645-1647, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31177914

RESUMO

IRGM is an established genetic risk factor for Crohn disease (CD) and several other inflammatory disorders. However, the mechanisms employed by IRGM to restrain the inflammation are not known. In our recent study, we showed that IRGM negatively regulates NLRP3 inflammasome activation. IRGM employs 2 parallel approaches to constrain inflammasome activation. First, IRGM directly interacts with NLRP3 and PYCARD/ASC, and mediates their SQSTM1/p62-dependent macroautophagic/autophagic degradation. Second, IRGM impedes inflammasome assembly by blocking the polymerization of NLRP3 and PYCARD. We also found that IRGM suppresses NLRP3-mediated exacerbated outcomes of dextran sodium sulfate (DSS)-induced colitis in a mouse model. Taken together, this study presents evidence that IRGM can directly regulate inflammation and protect from inflammatory diseases.


Assuntos
Autofagia , Inflamassomos , Animais , Sulfato de Dextrana , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Proteína Sequestossoma-1
18.
Neuroscience ; 358: 79-92, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28663093

RESUMO

Heat Stress (HS) induces diverse pathophysiological changes, which include brain ischemia, oxidative stress and neuronal damage. The present study was undertaken with the objective to ascertain whether neuroinflammation in Hypothalamus (HTH) caused under HS affects monoamine levels and hence, its physiological role in thermoregulation. Rats were exposed to HS in a heat simulation environmental chamber (Ambient temperature, Ta=45±0.5°C and Relative Humidity, RH=30±10%) with real-time measurement of core temperature (Tc) and skin temperature (Ts). Animals were divided into two subgroups: Moderate HS (MHS) (Tc=40°C) and Severe HS (SHS)/Heat stroke (Tc=42°C). Rats with MHS showed an increase in Mean Arterial Pressure (MAP) and Heart Rate (HR) while fall in MAP and rise in HR was observed in rats with SHS. In addition, oxidative stress and an increase in pyknotic neurons were observed in HTH. High levels of Adrenocorticotropic-hormone (ACTH), Epinephrine (EPI), Norepinephrine (NE) and Dopamine (DA) in the systemic circulation and progressive increase in EPI and DA levels in HTH were recorded after the thermal insult. Moreover, a substantial increase in Glutamate (Glu) level was observed in HTH as well as in systemic circulation of heat stroke rats. We found a rise in NE whereas a fall in Serotonin (5-HT) level in HTH at MHS, without perturbing inflammatory mediators. However, rats with SHS exhibited significant elevations in NF-kB, IL-1ß, COX2, GFAP and Iba1 protein expression in HTH. In conclusion, the data suggest that SHS induces neuroinflammation in HTH, which is associated with monoamines and Glu imbalances, leading to thermoregulatory disruption.


Assuntos
Monoaminas Biogênicas/metabolismo , Temperatura Corporal/fisiologia , Encefalite , Temperatura Alta/efeitos adversos , Zearalenona/análogos & derivados , Hormônio Adrenocorticotrópico/metabolismo , Análise de Variância , Animais , Pressão Sanguínea/fisiologia , Hormônio Liberador da Corticotropina/metabolismo , Ciclo-Oxigenase 2/metabolismo , Encefalite/etiologia , Encefalite/patologia , Encefalite/fisiopatologia , Proteína Glial Fibrilar Ácida/metabolismo , Frequência Cardíaca/fisiologia , Masculino , NF-kappa B/metabolismo , Estresse Oxidativo/fisiologia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Zearalenona/metabolismo
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