RESUMEN
Globins, such as myoglobin (Mb) and neuroglobin (Ngb), are ideal protein scaffolds for the design of functional metalloenzymes. To date, numerous approaches have been developed for enzyme design. This review presents a summary of the progress made in the design of functional metalloenzymes based on Mb and Ngb, with a focus on the exploitation of covalent interactions, including coordination bonds and covalent modifications. These include the construction of a metal-binding site, the incorporation of a non-native metal cofactor, the formation of Cys/Tyr-heme covalent links, and the design of disulfide bonds, as well as other Cys-covalent modifications. As exemplified by recent studies from our group and others, the designed metalloenzymes have potential applications in biocatalysis and bioconversions. Furthermore, we discuss the current trends in the design of functional metalloenzymes and highlight the importance of covalent interactions in the design of functional metalloenzymes.
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Globinas , Mioglobina , Proteínas del Tejido Nervioso , Neuroglobina , Neuroglobina/metabolismo , Neuroglobina/química , Mioglobina/química , Mioglobina/metabolismo , Globinas/química , Globinas/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Proteínas del Tejido Nervioso/química , Humanos , Animales , Hemo/química , Hemo/metabolismo , Sitios de Unión , Metaloproteínas/química , Metaloproteínas/metabolismo , Ingeniería de Proteínas/métodosRESUMEN
Neuroglobin, a member of the globin superfamily, is abundant in the brain, retina, and cerebellum of mammals and localizes to mitochondria. The protein exhibits neuroprotective capacities by participating in electron transfer, oxygen supply, and protecting against oxidative stress. Our objective was to determine whether neuroglobin overexpression can be used to treat neurological disorders. We chose Harlequin mice, which harbor a retroviral insertion in the first intron of the apoptosis-inducing factor gene resulting in the depletion of the corresponding protein essential for mitochondrial biogenesis. Consequently, Harlequin mice display degeneration of the cerebellum and suffer from progressive blindness and ataxia. Cerebellar ataxia begins in Harlequin mice at the age of 4 months and is characterized by neuronal cell disappearance, bioenergetics failure, and motor and cognitive impairments, which aggravated with aging. Mice aged 2 months received adeno-associated viral vectors harboring the coding sequence of neuroglobin or apoptosis-inducing factor in both cerebellar hemispheres. Six months later, Harlequin mice exhibited substantial improvements in motor and cognitive skills; probably linked to the preservation of respiratory chain function, Purkinje cell numbers and connectivity. Thus, without sharing functional properties with apoptosis-inducing factor, neuroglobin was efficient in reducing ataxia in Harlequin mice.
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Ataxia Cerebelosa , Cerebelo , Globinas , Mitocondrias , Proteínas del Tejido Nervioso , Neuroglobina , Animales , Ratones , Factor Inductor de la Apoptosis/metabolismo , Factor Inductor de la Apoptosis/genética , Ataxia Cerebelosa/metabolismo , Ataxia Cerebelosa/genética , Ataxia Cerebelosa/terapia , Cerebelo/metabolismo , Dependovirus/genética , Modelos Animales de Enfermedad , Expresión Génica , Terapia Genética/métodos , Vectores Genéticos/genética , Vectores Genéticos/administración & dosificación , Globinas/metabolismo , Globinas/genética , Homeostasis , Mitocondrias/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Proteínas del Tejido Nervioso/genética , Neuroglobina/metabolismo , Neuronas/metabolismoRESUMEN
BACKGROUND: This study aims to investigate whether isoquercitrin (Iso) exerts a neuroprotective role effect after cerebral ischemia-reperfusion (CIR) via up-regulating neuroglobin (Ngb) or reducing oxidative stress. METHODS: The middle cerebral artery occlusion/reperfusion (MCAO/R) model was constructed using Sprague Dawley rats. First, we divided 40 mice into 5 groups (n = 8): sham, MCAO/R, Low-dosed Iso (5 mg/kg Iso), Mid-dosed Iso (10 mg/kg Iso), and High-dosed Iso (20 mg/kg Iso). Then, 48 rats were separated into 6 groups (n = 8): sham, MCAO/R, Iso, artificial cerebrospinal fluid, Ngb antisense oligodeoxynucleotides (AS-ODNs), and AS-ODNs ± Iso. The effects of Iso on brain tissue injury and oxidative stress were evaluated using hematoxylin-eosin staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, immunofluorescence, western blotting, and real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and reactive oxygen species (ROS) detection. RESULTS: The neurologic score, infarct volume, histopathology, apoptosis rate, and ROS production were reduced in Iso dose-dependent. The Ngb expression enhanced in Iso dose-dependent. The oxidative stress-related factors SOD, GSH, CAT, Nrf2, HO-1, and HIF-1α levels also increased in Iso dose-dependent, whereas the MDA levels decreased. However, related regulation of Iso on brain tissue damage and oxidative stress were reversed after low expression of Ngb. CONCLUSION: Isoquercitrin played a neuroprotective role after CIR through up-regulating of Ngb and anti-oxidative stress.
Asunto(s)
Isquemia Encefálica , Fármacos Neuroprotectores , Daño por Reperfusión , Ratas , Ratones , Animales , Ratas Sprague-Dawley , Neuroglobina/metabolismo , Neuroglobina/farmacología , Especies Reactivas de Oxígeno/metabolismo , Daño por Reperfusión/patología , Isquemia Encefálica/prevención & control , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patología , Estrés Oxidativo , Apoptosis , Reperfusión , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/metabolismoRESUMEN
Cerebral ischemia/reperfusion (I/R) injury remains a grievous health threat, and herein effective therapy is urgently needed. This study explored the protection of neuroglobin (Ngb) in rats with cerebral I/R injury. The focal cerebral I/R rat models were established by middle cerebral artery occlusion (MCAO) and neuronal injury models were established by oxygen-glucose deprivation/reoxygenation (OGD/R) treatment. The brain injury of rats was assessed. Levels of Ngb, Bcl-2, Bax, endoplasmic reticulum stress (ERS)-related markers, and Syt1 were measured by immunofluorescence staining and Western blotting. The cytotoxicity in neurons was assessed by lactate dehydrogenase (LDH) release assay. Levels of intracellular Ca2+ and mitochondrial function-related indicators were determined. The binding between Ngb and Syt1 was detected by co-immunoprecipitation. Ngb was upregulated in cerebral I/R rats and its overexpression alleviated brain injury. In OGD/R-induced neurons, Ngb overexpression decreased LDH level and neuronal apoptosis, decreased Ca2+ content, and mitigated mitochondrial dysfunction and ERS-related apoptosis. However, Ngb silencing imposed the opposite effects. Importantly, Ngb could bind to Syt1. Syt1 knockdown partially counteracted the alleviation of Ngb on OGD/R-induced injury in neurons and cerebral I/R injury in rats. Briefly, Ngb extenuated cerebral I/R injury by repressing mitochondrial dysfunction and endoplasmic reticulum stress-mediated neuronal apoptosis through Syt1.
Asunto(s)
Isquemia Encefálica , Daño por Reperfusión , Ratas , Animales , Neuroglobina/metabolismo , Neuroglobina/farmacología , Neuronas , Apoptosis , Isquemia Encefálica/metabolismo , Daño por Reperfusión/prevención & control , Daño por Reperfusión/metabolismo , Estrés del Retículo Endoplásmico , Mitocondrias/metabolismo , Sinaptotagminas/metabolismo , Sinaptotagminas/farmacología , Glucosa/metabolismoRESUMEN
Pancreatic cancer is an extremely aggressive malignancy with a very disappointing prognosis. Neuroglobin (NGB), a member of the globin family, has been demonstrated to have a significant role in a variety of tumor forms. The possible role of NGB as a tumor suppressor gene in pancreatic cancer was investigated in this work. Information from the public dataset TCGA combined with GTEx was used to analyze the finding that NGB was commonly downregulated in pancreatic cancer cell lines and tissues, correlating with patient age and prognosis. The expression of NGB in pancreatic cancer was investigated via RT-PCR, qRT-PCR, and Western blot experiments. In-vitro and in-vivo assays, NGB elicited cell cycle arrest in the S phase and apoptosis, hindered migration and invasion, reversed the EMT process, and suppressed cell proliferation and development. The mechanism of action of NGB was predicted via bioinformatics analysis and validated using Western blot and co-IP experiments revealed that NGB inhibited the EGFR/AKT/ERK pathway by binding to and reducing expression of GNAI1 and p-EGFR. In addition, pancreatic cancer cells overexpressing NGB showed increased drug sensitivity to gefitinib (EGFR-TKI). In conclusion, NGB inhibits pancreatic cancer progression by specifically targeting the GNAI1/EGFR/AKT/ERK signaling axis.
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Neuroglobina , Neoplasias Pancreáticas , Proteínas Proto-Oncogénicas c-akt , Humanos , Línea Celular Tumoral , Proliferación Celular , Receptores ErbB/genética , Receptores ErbB/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuroglobina/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismoRESUMEN
BACKGROUND: The incidence of colorectal cancer (CRC) has increased in recent years. Identification of accurate tumor markers has become the focus of CRC research. Early and frequent DNA methylation tends to occur in cancer. Thus, identifying accurate methylation biomarkers would improve the efficacy of CRC treatment. Neuroglobin (NGB) is involved in neurological and oncological diseases. However, there are currently no reports on epigenetic regulation involvement of NGB in CRC. RESULTS: NGB was downregulated or silenced in majority CRC tissues and cell lines. The hypermethylation of NGB was detected in tumor tissue, but no or a very low methylation frequency in normal tissues. Overexpression of NGB induced G2/M phase arrest and apoptosis, suppressed proliferation, migration, invasion in vitro, and inhibited CRC tumor growth and angiogenesis in vivo. Isobaric tag for relative and absolute quantitation (Itraq)-based proteomics identified approximately 40% proteins related to cell-cell adhesion, invasion, and tumor vessel formation in the tumor microenvironment, among which GPR35 was proved critical for NGB-regulated tumor angiogenesis suppression in CRC. CONCLUSIONS: NGB, an epigenetically silenced factor, inhibits metastasis through the GPR35 in CRC. It is expected to grow into a potential cancer risk assessment factor and a valuable biomarker for early diagnosis and prognosis assessment of CRC.
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Neoplasias Colorrectales , Metilación de ADN , Humanos , Neuroglobina/genética , Neuroglobina/metabolismo , Epigénesis Genética , Línea Celular Tumoral , Neoplasias Colorrectales/patología , Biomarcadores/metabolismo , Regulación Neoplásica de la Expresión Génica , Proliferación Celular , Microambiente Tumoral , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismoRESUMEN
The discovery of neuroglobin (Ngb), a brain- or neuron-specific member of the hemoglobin family, has revolutionized our understanding of brain oxygen metabolism. Currently, how Ngb plays such a role remains far from clear. Here, we report a novel mechanism by which Ngb might facilitate neuronal oxygenation upon hypoxia or anemia. We found that Ngb was present in, co-localized to, and co-migrated with mitochondria in the cell body and neurites of neurons. Hypoxia induced a sudden and prominent migration of Ngb towards the cytoplasmic membrane (CM) or cell surface in living neurons, and this was accompanied by the mitochondria. In vivo, hypotonic and anemic hypoxia induced a reversible Ngb migration toward the CM in cerebral cortical neurons in rat brains but did not alter the expression level of Ngb or its cytoplasm/mitochondria ratio. Knock-down of Ngb by RNA interference significantly diminished respiratory succinate dehydrogenase (SDH) and ATPase activity in neuronal N2a cells. Over-expression of Ngb enhanced SDH activity in N2a cells upon hypoxia. Mutation of Ngb at its oxygen-binding site (His64) significantly increased SDH activity and reduced ATPase activity in N2a cells. Taken together, Ngb was physically and functionally linked to mitochondria. In response to an insufficient oxygen supply, Ngb migrated towards the source of oxygen to facilitate neuronal oxygenation. This novel mechanism of neuronal respiration provides new insights into the understanding and treatment of neurological diseases such as stroke and Alzheimer's disease and diseases that cause hypoxia in the brain such as anemia.
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Anemia , Globinas , Ratas , Animales , Neuroglobina/metabolismo , Globinas/genética , Globinas/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Hipoxia/metabolismo , Encéfalo/metabolismo , Oxígeno , Anemia/metabolismo , Adenosina Trifosfatasas/metabolismoRESUMEN
A double mutant of human H64M/V71C neuroglobin (Ngb) was engineered, which formed a single thioether bond as that in atypical cytochrome c, whereas the heme distal Met64 was oxidized to both sulfoxide (SO-Met) and sulfone (SO2 -Met). By contrast, no Cys-heme cross-link was formed in V71C Ngb with His64/His96 coordination, as shown by the X-ray crystal structure, which indicates that an open distal site facilitates the activation of heme iron for structural modifications.
Asunto(s)
Citocromos c , Sulfuros , Humanos , Citocromos c/genética , Citocromos c/metabolismo , Hemo/química , Neuroglobina/química , Neuroglobina/metabolismo , Oxidación-Reducción , Ingeniería de ProteínasRESUMEN
Besides the canonical pathway of L-arginine oxidation to produce nitric oxide (NO) in vivo, the nitrate-nitrite-NO pathway has been widely accepted as another source for circulating NO in mammals, especially under hypoxia. To date, there have been at least ten heme-containing nitrite reductase-like proteins discovered in mammals with activities mainly identified in vitro, including four globins (hemoglobin, myoglobin, neuroglobin (Ngb), cytoglobin (Cygb)), three mitochondrial respiratory chain enzymes (cytochrome c oxidase, cytochrome bc1, cytochrome c), and three other heme proteins (endothelial nitric oxide synthase, cytochrome P450 and indoleamine 2,3-dioxygenase 1 (IDO1)). The pathophysiological functions of these proteins are closely related to their redox and spectroscopic properties, as well as their protein structure, although the physiological roles of Ngb, Cygb and IDO1 remain unclear. So far, comprehensive summaries of the redox and spectroscopic properties of these nitrite reductase-like hemoproteins are still lacking. In this review, we have mainly summarized the published data on the application of ultraviolet-visible, electron paramagnetic resonance, circular dichroism and resonance Raman spectroscopies, and X-ray crystallography in studying nitrite reductase-like activity of these 10 proteins, in order to sort out the relationships among enzymatic function, structure and spectroscopic characterization, which might help in understanding their roles in redox biology and medicine.
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Proteínas del Tejido Nervioso , Nitrito Reductasas , Animales , Nitrito Reductasas/química , Proteínas del Tejido Nervioso/química , Globinas/química , Citoglobina/metabolismo , Oxidación-Reducción , Neuroglobina/metabolismo , Óxido Nítrico/química , Mamíferos/metabolismoRESUMEN
Neuroglobin is an oxygen-binding heme protein expressed predominantly in the brain. Despite many years of research, the exact distribution and expression of neuroglobin in the neocortical development and under mild hypoxia stress still remain unclear. Therefore, we aim to explore the expression of neuroglobin during neocortex expansion and under mild hypoxia stress in vivo. We used Kunming mice to examine the expression of Ngb protein during neocortex expansion. In addition, we analyzed the density of Ngb-positive neural stem cells using the Image-Pro PLUS (v.6) computer software program (Media Cybernetics, Inc.). Our data indicated that the density of the neuroglobin-positive neurons in mice cerebral cortex displayed a downward trend after birth compared with high expression of neuroglobin in a prenatal period. Similarly, we identified that neurons were capable of ascending neuroglobin levels in response to mild hypoxic stress compared with the no intervention group. These findings suggest that neuroglobin behaves as a compensatory protein regulating oxygen provision in the process of neocortical development or under physiological hypoxia, further contributing to the discovery of novel therapeutic methods for neurological disorders, which is clinically important.
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Globinas , Proteínas del Tejido Nervioso , Animales , Encéfalo/metabolismo , Globinas/genética , Globinas/metabolismo , Hipoxia/metabolismo , Ratones , Proteínas del Tejido Nervioso/metabolismo , Neuroglobina/metabolismo , OxígenoRESUMEN
Since its discovery in 2000 [...].
Asunto(s)
Globinas , Neoplasias , Encéfalo/metabolismo , Globinas/metabolismo , Humanos , Proteínas del Tejido Nervioso/metabolismo , Neuroglobina/metabolismoRESUMEN
Purpose: In this study, we used broadband near-infrared spectroscopy, a non-invasive optical technique, to investigate in real time the possible role of neuroglobin in retinal hemodynamics and metabolism. Methods: Retinae of 12 C57 mice (seven young and five old) and seven young neuroglobin knockouts (Ngb-KOs) were exposed to light from a low-power halogen source, and the back-reflected light was used to calculate changes in the concentration of oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (HHb), and oxidized cytochrome c oxidase (oxCCO). Results: The degree of change in the near-infrared spectroscopy signals associated with HHb, HbO2, and oxCCO was significantly greater in young C57 mice compared to the old C57 mice (P < 0.05) and the Ngb-KO model (P < 0.005). Conclusions: Our results reveal a possible role of Ngb in regulating retinal function, as its absence in the retinae of a knockout mouse model led to suppressed signals that are associated with hemodynamics and oxidative metabolism. Translational Relevance: Near-infrared spectroscopy enabled the non-invasive detection of characteristic signals that differentiate between the retina of a neuroglobin knockout mouse model and that of a wild-type model. Further work is needed to evaluate the source of the signal differences and how these differences relate to the presence or absence of neuroglobin in the ganglion, bipolar, or amacrine cells of the retina.
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Neuroglobina , Oxihemoglobinas , Retina , Animales , Hemodinámica , Ratones , Neuroglobina/metabolismo , Oxihemoglobinas/metabolismo , Retina/metabolismoRESUMEN
We produced a neuroglobin variant, namely, Ngb CDless, with the excised CDloop- and D-helix, directly joining the C- and E-helices. The CDless variant retained bis-His hexacoordination, and we investigated the role of the CDloop-D-helix unit in controlling the CO binding and structural dynamics by an integrative approach based on X-ray crystallography, rapid mixing, laser flash photolysis, resonance Raman spectroscopy, and molecular dynamics simulations. Rapid mixing and laser flash photolysis showed that ligand affinity was unchanged with respect to the wild-type protein, albeit with increased on and off constants for rate-limiting heme iron hexacoordination by the distal His64. Accordingly, resonance Raman spectroscopy highlighted a more open distal pocket in the CO complex that, in agreement with MD simulations, likely involves His64 swinging inward and outward of the distal heme pocket. Ngb CDless displays a more rigid overall structure with respect to the wild type, abolishing the structural dynamics of the CDloop-D-helix hypothesized to mediate its signaling role, and it retains ligand binding control by distal His64. In conclusion, this mutant may represent a tool to investigate the involvement of CDloop-D-helix in neuroprotective signaling in a cellular or animal model.
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Neuroglobina/química , Animales , Hemo/química , Ligandos , Ratones , Neuroglobina/metabolismoRESUMEN
Most neurodegenerative diseases such as Alzheimer's disease are proteinopathies linked to the toxicity of amyloid oligomers. Treatments to delay or cure these diseases are lacking. Using budding yeast, we report that the natural lipid tripentadecanoin induces expression of the nitric oxide oxidoreductase Yhb1 to prevent the formation of protein aggregates during aging and extends replicative lifespan. In mammals, tripentadecanoin induces expression of the Yhb1 orthologue, neuroglobin, to protect neurons against amyloid toxicity. Tripentadecanoin also rescues photoreceptors in a mouse model of retinal degeneration and retinal ganglion cells in a Rhesus monkey model of optic atrophy. Together, we propose that tripentadecanoin affects p-bodies to induce neuroglobin expression and offers a potential treatment for proteinopathies and retinal neurodegeneration.
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Amiloide , Lípidos , Agregación Patológica de Proteínas , Animales , Ratones , Enfermedad de Alzheimer , Amiloide/efectos de los fármacos , Amiloide/metabolismo , Péptidos beta-Amiloides/efectos de los fármacos , Péptidos beta-Amiloides/metabolismo , Dioxigenasas , Hemoproteínas , Lípidos/farmacología , Mamíferos , Neuroglobina/efectos de los fármacos , Neuroglobina/metabolismo , Cuerpos de Procesamiento/efectos de los fármacos , Cuerpos de Procesamiento/metabolismo , Agregación Patológica de Proteínas/genética , Agregación Patológica de Proteínas/metabolismo , Células Ganglionares de la Retina/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiaeRESUMEN
Schistosomes are blood-dwelling parasites that are constantly exposed to high-level oxidative stress arising from parasite-intrinsic and host defense mechanisms. To survive in their hosts, schistosomes require an antioxidant system to minimize with oxidative stress. Several schistosome antioxidant enzymes have been identified and have been suggested to play indispensable antioxidant roles for the parasite. In addition to antioxidant enzymes, non-enzymatic antioxidants including small molecules, peptides, and proteins have been identified and characterized. Neuroglobin (Ngb), a nervous system-specific heme-binding protein, has been classified as a non-enzymatic antioxidant and is capable of scavenging a variety of free radical species. The antioxidant activity of Ngb has been well-studied in humans. Ngb is involved in cellular oxygen homeostasis and reactive oxygen/nitrogen scavenging in the central and peripheral nervous systems, but its functions in schistosome parasites have not yet been characterized. In this study, we aimed to characterize the molecular properties and functions of Schistosoma mekongi Ngb (SmeNgb) using bioinformatic, biochemical, and molecular biology approaches. The amino acid sequence of Ngb was highly conserved among schistosomes as well as closely related trematodes. SmeNgb was abundantly localized in the gastrodermis, vitelline, and ovary of adult female S. mekongi worms as well as in the tegument of adult male worms. Assessment of antioxidant activity demonstrated that recombinant SmeNgb had Fe2+ chelating and hydrogen peroxide scavenging activities. Intriguingly, siRNA silencing of SmeNgb gene expression resulted in tegument pathology. Understanding the properties and functions of SmNgb will help in future development of effective treatments and vaccines against S. mekongi, other schistosome parasites, and other platyhelminths.
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Antioxidantes , Schistosoma , Animales , Antioxidantes/metabolismo , Femenino , Masculino , Neuroglobina/metabolismo , Estrés Oxidativo , Oxígeno/metabolismo , Schistosoma/genética , Schistosoma/metabolismoRESUMEN
Sevoflurane, a commonly used inhaled anesthetic, causes endogenous apoptosis in fetal rats. Microglia polarization is associated with inflammation, and the IL-10/STAT3/SOCS3 pathway is involved in this process. Neuroglobin (Ngb) is a neuroprotective protein which exhibits an anti-inflammatory effect. The purpose of this study was to investigate whether neurotoxicity induced by sevoflurane exposure in prenatal rats correlates with neuroinflammation and microglia polarization and whether Ngb can moderate this response. We found that exposure to sevoflurane on the 20th day of gestation (G20) induced discernable inflammation in postnatal day 0 (P0) rats, promoted M1 polarization of microglia, and inhibited M2 polarization. Hemin-mediated Ngb elevation inhibited sevoflurane-induced neuroinflammation. Additionally, elevated Ngb inhibited M1 polarization and promoted M2 polarization of microglia. We also found that elevated Ngb could alleviate the effect of sevoflurane on the expression of Interleukin-10 (IL-10), phosphorylated-signal transduction and activators of transcription 3 (P-STAT3), and suppressor of cytokine signaling 3 (SOCS3). Furthermore, we found that elevated Ngb ameliorated the effects of sevoflurane on long-term exploratory behavior and learning and memory in the offspring. Our results show that Ngb alleviates the neurotoxicity of sevoflurane to fetal rats by inhibiting neuroinflammation and affecting microglial polarization, a process which may involve the IL-10/STAT3/SOCS3 pathway.
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Microglía , Síndromes de Neurotoxicidad , Animales , Femenino , Microglía/metabolismo , Neuroglobina/metabolismo , Neuroglobina/farmacología , Enfermedades Neuroinflamatorias , Síndromes de Neurotoxicidad/metabolismo , Embarazo , Ratas , Sevoflurano/farmacologíaRESUMEN
Neuroglobin is expressed in vertebrate brain and belongs to a branch of the globin family that diverged early in evolution. Sequence conservation and presence in nervous cells of several taxa suggests a relevant role in the nervous system, with tight structural restraints. Twenty years after its discovery, a rich scientific literature provides convincing evidence of the involvement of neuroglobin in sustaining neuron viability in physiological and pathological conditions however, a full and conclusive picture of its specific function, or set of functions is still lacking. The difficulty of unambiguously assigning a precise mechanism and biochemical role to neuroglobin might arise from the participation to one or more cell mechanism that redundantly guarantee the functioning of the highly specialized and metabolically demanding central nervous system of vertebrates. Here we collect findings and hypotheses arising from recent biochemical, biophysical, structural, in cell and in vivo experimental work on neuroglobin, aiming at providing an overview of the most recent literature. Proteins are said to have jobs and hobbies, it is possible that, in the case of neuroglobin, evolution has selected for it more than one job, and support to cover for its occasional failings. Disentangling the mechanisms and roles of neuroglobin is thus a challenging task that might be achieved by considering data from different disciplines and experimental approaches.
Asunto(s)
Globinas , Proteínas del Tejido Nervioso , Animales , Encéfalo/metabolismo , Globinas/química , Globinas/genética , Humanos , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/genética , Neuroglobina/metabolismo , Neuronas/metabolismoRESUMEN
Microglia are the immune competent cell of the central nervous system (CNS), promoting brain homeostasis and regulating inflammatory response against infection and injury. Chronic or exacerbated neuroinflammation is a cause of damage in several brain pathologies. Endogenous carbon monoxide (CO), produced from the degradation of heme, is described as anti-apoptotic and anti-inflammatory in several contexts, including in the CNS. Neuroglobin (Ngb) is a haemoglobin-homologous protein, which upregulation triggers antioxidant defence and prevents neuronal apoptosis. Thus, we hypothesised a crosstalk between CO and Ngb, in particular, that the anti-neuroinflammatory role of CO in microglia depends on Ngb. A novel CO-releasing molecule (ALF826) based on molybdenum was used for delivering CO in microglial culture.BV-2 mouse microglial cell line was challenged with lipopolysaccharide (LPS) for triggering inflammation, and after 6 h ALF826 was added. CO exposure limited inflammation by decreasing inducible nitric oxide synthase (iNOS) expression and the production of nitric oxide (NO) and tumour necrosis factor-α (TNF-α), and by increasing interleukine-10 (IL-10) release. CO-induced Ngb upregulation correlated in time with CO's anti-inflammatory effect. Moreover, knocking down Ngb reversed the anti-inflammatory effect of CO, suggesting that dependents on Ngb expression. CO-induced Ngb upregulation was independent on ROS signalling, but partially dependent on the transcriptional factor SP1. Finally, microglial cell metabolism is also involved in the inflammatory response. In fact, LPS treatment decreased oxygen consumption in microglia, indicating a switch to glycolysis, which is associated with a proinflammatory. While CO treatment increased oxygen consumption, reverting LPS effect and indicating a metabolic shift into a more oxidative metabolism. Moreover, in the absence of Ngb, this phenotype was no longer observed, indicating Ngb is needed for CO's modulation of microglial metabolism. Finally, the metabolic shift induced by CO did not depend on alteration of mitochondrial population. In conclusion, neuroglobin emerges for the first time as a key player for CO signalling against exacerbated inflammation in microglia.
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Monóxido de Carbono , Microglía , Animales , Monóxido de Carbono/metabolismo , Monóxido de Carbono/farmacología , Inflamación/patología , Lipopolisacáridos/farmacología , Ratones , Microglía/metabolismo , Neuroglobina/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismoRESUMEN
Oxidative stressinduced neuronal cell death contributes significantly to the physiological processes of a number of neurological disorders. Polydatin (PD) has been reported to protect against Alzheimer's disease (AD), ischemic stroke and traumatic brain injury. However, the underlying neuroprotective mechanisms remain to be elucidated. The current study suggested that PD activates AKT/cAMP response elementbinding protein (CREB) signaling and induces neuroglobin (Ngb) to protect neuronal cells from hydrogen peroxide (H2O2) in vitro. PD inhibited the H2O2induced neuronal cell death of primary mouse cortical neurons and N2a cells. Functional studies showed that PD attenuated H2O2induced mitochondrial dysfunction and mitochondrial reactive oxygen species production. Mechanistically, PD was verified to induce the phosphorylation of AKT and CREB and increase the protein level of Ngb. The luciferase assay results showed that Ngb transcriptional activity was activated by CREB, especially after PD treatment. It was further indicated that PD increased the transcription of Ngb by enhancing the binding of CREB to the promoter region of Ngb. Finally, Ngb knockdown largely attenuated the neuroprotective role of PD against H2O2. The results indicated that PD protected neuronal cells from H2O2 by activating CREB/Ngb signaling in neuronal cells, indicating that PD has a neuroprotective effect against neurodegenerative diseases.
Asunto(s)
Glucósidos/farmacología , Neuronas/metabolismo , Estilbenos/farmacología , Animales , Muerte Celular/efectos de los fármacos , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/efectos de los fármacos , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Femenino , Glucósidos/metabolismo , Peróxido de Hidrógeno/efectos adversos , Masculino , Ratones , Ratones Endogámicos C57BL , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neuroglobina/efectos de los fármacos , Neuroglobina/metabolismo , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/metabolismo , Fármacos Neuroprotectores/farmacología , Oxidación-Reducción/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno , Transducción de Señal/efectos de los fármacos , Estilbenos/metabolismoRESUMEN
Globin proteins exist in every cell type of the vasculature, from erythrocytes to endothelial cells, vascular smooth muscle cells, and peripheral nerve cells. Many globin subtypes are also expressed in muscle tissues (including cardiac and skeletal muscle), in other organ-specific cell types, and in cells of the central nervous system (CNS). The ability of each of these globins to interact with molecular oxygen (O2) and nitric oxide (NO) is preserved across these contexts. Endothelial α-globin is an example of extraerythrocytic globin expression. Other globins, including myoglobin, cytoglobin, and neuroglobin, are observed in other vascular tissues. Myoglobin is observed primarily in skeletal muscle and smooth muscle cells surrounding the aorta or other large arteries. Cytoglobin is found in vascular smooth muscle but can also be expressed in nonvascular cell types, especially in oxidative stress conditions after ischemic insult. Neuroglobin was first observed in neuronal cells, and its expression appears to be restricted mainly to the CNS and the peripheral nervous system. Brain and CNS neurons expressing neuroglobin are positioned close to many arteries within the brain parenchyma and can control smooth muscle contraction and thus tissue perfusion and vascular reactivity. Overall, reactions between NO and globin heme iron contribute to vascular homeostasis by regulating vasodilatory NO signals and scavenging reactive species in cells of the mammalian vascular system. Here, we discuss how globin proteins affect vascular physiology, with a focus on NO biology, and offer perspectives for future study of these functions.