Carrier capability of halloysite nanotubes for the intracellular delivery of antisense PNA targeting mRNA of neuroglobin gene.

Peptide nucleic acid (PNA) is a DNA mimic that shows good stability against nucleases and proteases, forming strongly recognized complementary strands of DNA and RNA. However, due to its feeble ability to cross the cellular membrane, PNA activity and its targeting gene action is limited. Halloysite nanotubes (HNTs) are a natural and low-cost aluminosilicate clay. Because of their peculiar ability to cross cellular membrane, HNTs represent a valuable candidate for delivering genetic materials into cells. Herein, two differently charged 12-mer PNAs capable of recognizing as molecular target a 12-mer DNA molecule mimicking a purine-rich tract of neuroglobin were synthetized and loaded onto HNTs by electrostatic attraction interactions. After characterization, the kinetic release was also assessed in media mimicking physiological conditions. Resonance light scattering measurements assessed their ability to bind complementary single-stranded DNA. Furthermore, their intracellular delivery was assessed by confocal laser scanning microscopy on living MCF-7 cells incubated with fluorescence isothiocyanate (FITC)-PNA and HNTs labeled with a probe. The nanomaterials were found to cross cellular membrane and cell nuclei efficiently. Finally, it is worth mentioning that the HNTs/PNA can reduce the level of neuroglobin gene expression, as shown by reverse transcription-quantitative polymerase chain reaction and western blotting analysis.

Neuroglobin inhibits pancreatic cancer proliferation and metastasis by targeting the GNAI1/EGFR/AKT/ERK signaling axis.

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.

Neuroglobin plays as tumor suppressor by disrupting the stability of GPR35 in colorectal cancer.

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.

A Novel Resveratrol-Induced Pathway Increases Neuron-Derived Cell Resilience against Oxidative Stress.

A promising therapeutic strategy to delay and/or prevent the onset of neurodegenerative diseases (NDs) could be to restore neuroprotective pathways physiologically triggered by neurons against stress injury. Recently, we identified the accumulation of neuroglobin (NGB) in neuronal cells, induced by the 17ß-estradiol (E2)/estrogen receptor ß (ERß) axis, as a protective response that increases mitochondria functionality and prevents the activation of apoptosis, increasing neuron resilience against oxidative stress. Here, we would verify if resveratrol (Res), an ERß ligand, could reactivate NGB accumulation and its protective effects against oxidative stress in neuronal-derived cells (i.e., SH-SY5Y cells). Our results demonstrate that ERß/NGB is a novel pathway triggered by low Res concentrations that lead to rapid and persistent NGB accumulation in the cytosol and in mitochondria, where the protein contributes to reducing the apoptotic death induced by hydrogen peroxide (H2O2). Intriguingly, Res conjugation with gold nanoparticles increases the stilbene efficacy in enhancing neuron resilience against oxidative stress. As a whole, ERß/NGB axis regulation is a novel mechanism triggered by low concentration of Res to regulate, specifically, the neuronal cell resilience against oxidative stress reducing the triggering of the apoptotic cascade.

Neuroglobin Facilitates Neuronal Oxygenation through Tropic Migration under Hypoxia or Anemia in Rat: How Does the Brain Breathe?

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.

Resveratrol Analogs and Prodrugs Differently Affect the Survival of Breast Cancer Cells Impairing Estrogen/Estrogen Receptor α/Neuroglobin Pathway.

Breast cancer is the first leading tumor in women in terms of incidence worldwide. Seventy percent of cases are estrogen receptor (ER) α-positive. In these malignancies, 17ß-estradiol (E2) via ERα increases the levels of neuroglobin (NGB), a compensatory protein that protects cancer cells from stress-induced apoptosis, including chemotherapeutic drug treatment. Our previous data indicate that resveratrol (RSV), a plant-derived polyphenol, prevents E2/ERα-induced NGB accumulation in this cellular context, making E2-dependent breast cancer cells more prone to apoptosis. Unfortunately, RSV is readily metabolized, thus preventing its effectiveness. Here, four different RSV analogs have been developed, and their effect on the ERα/NGB pathway has been compared with RSV conjugated with highly hydrophilic gold nanoparticles as prodrug to evaluate if RSV derivatives maintain the breast cancer cells' susceptibility to the chemotherapeutic drug paclitaxel as the original compound. Results demonstrate that RSV conjugation with gold nanoparticles increases RSV efficacy, with respect to RSV analogues, reducing NGB levels and enhancing the pro-apoptotic action of paclitaxel, even preventing the anti-apoptotic action exerted by E2 treatment on these cells. Overall, RSV conjugation with gold nanoparticles makes this complex a promising agent for medical application in breast cancer treatment.

Comparative study on the distribution and expression of Neuroglobin and Hypoxia-inducible factor-1α in the telencephalon of yak and cattle / Estudo comparativo da distribuição e expressão de fator-1 indutível por neuroglobina e hipóxia no telencéfalo de iaques e bovinos

Abstract The telencephalon refers to the most highly developed and anterior part of the forebrain, consisting mainly of the cerebral hemispheres. The study determined Neuroglobin (Ngb) and Hypoxia-inducible factor (HIF-1α) expression in the telencephalon of yak and cattle, and compare the expression and distribution pattern of Ngb and HIF-1α in the two animals. Immunohistochemistry (IHC), quantitative real-time Polymerase Chain Reaction (qRT-PCR), and Western blot (WB) were employed to investigate Ngb and Hif-1α expression in the telencephalon of yak and cattle. mRNA and protein expressions of Ngb and HIF-1α showed positive in different tissues of the yak and cattle telencephalon. Ngb expression in tissues of the yak recorded higher as compare to cattle while HIF-1α expression was found higher in cattle than yak. The HIF-1α expression in some tissues of yak telencephalon was consistent with the cattle. The results documented that HIF-1α may have a direct or indirect synergistic effect on Ngb expression in the yak telencephalon to improve hypoxia adaptation. It is suggested that yak may need more Ngb expression for adaptation, but the expression of HIF-1α seems to be down-regulated during long-term adaptation, and the specific causes of this phenomenon needs to be further verified.

Resumo O telencéfalo refere-se à parte anterior e mais desenvolvida do prosencéfalo, consistindo principalmente dos hemisférios cerebrais. O estudo determinou a expressão de neuroglobina (Ngb) e fator indutível por hipóxia (HIF-1α) no telencéfalo de iaques e bovinos e comparou a expressão e o padrão de distribuição de Ngb e HIF-1α nos dois animais. Imuno-histoquímica (IHC), reação em cadeia da polimerase quantitativa em tempo real (qRT-PCR) e Western blot (WB) foram empregados para investigar a expressão de Ngb e Hif-1α no telencéfalo de iaques e bovinos. As expressões de mRNA e proteínas de Ngb e HIF-1α mostraram-se positivas em diferentes tecidos do telencéfalo de iaque e bovino. A expressão de Ngb nos tecidos do iaque foi registrada mais alta em comparação com o gado, enquanto a expressão do HIF-1α foi encontrada mais alta no gado do que no iaque. A expressão de HIF-1α em alguns tecidos do telencéfalo de iaque foi consistente com o gado. Os resultados documentaram que o HIF-1α pode ter um efeito sinérgico direto ou indireto na expressão de Ngb no telencéfalo de iaque para melhorar a adaptação à hipóxia. É sugerido que o iaque pode precisar de mais expressão de Ngb para adaptação, mas a expressão de HIF-1α parece ser regulada para baixo durante a adaptação de longo prazo, e as causas específicas desse fenômeno precisam ser verificadas.

Comparative study of the distribution and expression of Neuroglobin and Hypoxia-inducible factor-1α in the adult and young Yak Brain / Estudo comparativo da distribuição e expressão de neuroglobina e fator-1α indutível por hipóxia em adultos e jovens iaques (Yak Brain)

Background: The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. Aim: The study examined the expression of Neuroglobin (Ngb) and Hypoxia-inducible factor-1α (Hif-1α) in adult and young yak brain tissues, and provided researchers with meaningful insight into the anatomy, physiology, and biochemistry of this mammal. Method: The study employed immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR), and Western blot (WB) to obtain the results. Results: Ngb and Hif-1α were significantly (P<0.05) expressed in the cerebellar cortex, piriform lobe, medulla, and corpus callosum of the adult yak while in the young yak brain tissues, the protein expressions were significantly found in the white matter of the cerebellum, pineal gland, corpus callosum, and cerebellar cortex. The Ngb and Hif-1α expression showed similarities and differences. This may have resulted from similar animal species, source of nutrition, age factors, brain size, emotional activities, and communication. The findings documented that Ngb and Hif-1α are commonly expressed in various adult and young yak brain tissues. Multiple roles in the brain tissues of the adult and young yaks are involved in the expression and distribution and are proposed to play a significant role in the adaptation of the yak to the high altitude environment. Conclusion: This study provides meaningful data to understand the adaptive mechanism to hypoxia and recommended researchers to expand on the adaptive mechanism and brain tissues that are not recorded.

Contexto: O cérebro é um órgão que funciona como o centro do sistema nervoso em todos os animais vertebrados e na maioria dos invertebrados. Objetivo: O estudo examinou a expressão de neuroglobina (Ngb) e fator-1α indutível por hipóxia (Hif-1α) em tecidos cerebrais de iaques adultos e jovens e forneceu aos pesquisadores uma visão significativa da anatomia, fisiologia e bioquímica desse mamífero. Método: O estudo utilizou imuno-histoquímica (IHC), PCR quantitativo em tempo real (qRT-PCR) e western blot (WB) para a obtenção dos resultados. Resultados: Ngb e Hif-1α foram significativamente (P < 0,05) expressos no córtex cerebelar, lobo piriforme, medula e corpo caloso do iaque adulto, enquanto nos tecidos cerebrais do iaque jovem as expressões proteicas foram encontradas significativamente na substância branca do cerebelo, glândula pineal, corpo caloso e córtex cerebelar. A expressão de Ngb e Hif-1α apresentou semelhanças e diferenças. Isso pode ter resultado de espécies animais semelhantes, fonte de nutrição, fatores de idade, tamanho do cérebro, atividades emocionais e comunicação. Os resultados documentaram que o Ngb e o Hif-1α são comumente expressos em vários tecidos cerebrais de iaques adultos e jovens. Múltiplos papéis nos tecidos cerebrais de iaques adultos e jovens estão envolvidos na expressão e distribuição e são propostos para desempenhar um papel significativo na adaptação do iaque ao ambiente de alta altitude. Conclusão: Este estudo fornece dados significativos para compreender o mecanismo adaptativo à hipóxia e recomendou que os pesquisadores expandissem o mecanismo adaptativo e os tecidos cerebrais que não foram registrados.

Comparative study on the distribution and expression of Neuroglobin and Hypoxia-inducible factor-1α in the telencephalon of yak and cattle / Estudo comparativo da distribuição e expressão de fator-1α indutível por neuroglobina e hipóxia no telencéfalo de iaques e bovinos

The telencephalon refers to the most highly developed and anterior part of the forebrain, consisting mainly of the cerebral hemispheres. The study determined Neuroglobin (Ngb) and Hypoxia-inducible factor (HIF-1α) expression in the telencephalon of yak and cattle, and compare the expression and distribution pattern of Ngb and HIF-1α in the two animals. Immunohistochemistry (IHC), quantitative real-time Polymerase Chain Reaction (qRT-PCR), and Western blot (WB) were employed to investigate Ngb and Hif-1α expression in the telencephalon of yak and cattle. mRNA and protein expressions of Ngb and HIF-1α showed positive in different tissues of the yak and cattle telencephalon. Ngb expression in tissues of the yak recorded higher as compare to cattle while HIF-1α expression was found higher in cattle than yak. The HIF-1α expression in some tissues of yak telencephalon was consistent with the cattle. The results documented that HIF-1α may have a direct or indirect synergistic effect on Ngb expression in the yak telencephalon to improve hypoxia adaptation. It is suggested that yak may need more Ngb expression for adaptation, but the expression of HIF-1α seems to be down-regulated during long-term adaptation, and the specific causes of this phenomenon needs to be further verified.

O telencéfalo refere-se à parte anterior e mais desenvolvida do prosencéfalo, consistindo principalmente dos hemisférios cerebrais. O estudo determinou a expressão de neuroglobina (Ngb) e fator indutível por hipóxia (HIF-1α) no telencéfalo de iaques e bovinos e comparou a expressão e o padrão de distribuição de Ngb e HIF-1α nos dois animais. Imuno-histoquímica (IHC), reação em cadeia da polimerase quantitativa em tempo real (qRT-PCR) e Western blot (WB) foram empregados para investigar a expressão de Ngb e Hif-1α no telencéfalo de iaques e bovinos. As expressões de mRNA e proteínas de Ngb e HIF-1α mostraram-se positivas em diferentes tecidos do telencéfalo de iaque e bovino. A expressão de Ngb nos tecidos do iaque foi registrada mais alta em comparação com o gado, enquanto a expressão do HIF-1α foi encontrada mais alta no gado do que no iaque. A expressão de HIF-1α em alguns tecidos do telencéfalo de iaque foi consistente com o gado. Os resultados documentaram que o HIF-1α pode ter um efeito sinérgico direto ou indireto na expressão de Ngb no telencéfalo de iaque para melhorar a adaptação à hipóxia. É sugerido que o iaque pode precisar de mais expressão de Ngb para adaptação, mas a expressão de HIF-1α parece ser regulada para baixo durante a adaptação de longo prazo, e as causas específicas desse fenômeno precisam ser verificadas.

Comparative study of the distribution and expression of Neuroglobin and Hypoxia-inducible factor-1α in the adult and young Yak Brain / Estudo comparativo da distribuição e expressão de neuroglobina e fator-1α indutível por hipóxia em adultos e jovens iaques (Yak Brain)

Abstract Background The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. Aim The study examined the expression of Neuroglobin (Ngb) and Hypoxia-inducible factor-1α (Hif-1α) in adult and young yak brain tissues, and provided researchers with meaningful insight into the anatomy, physiology, and biochemistry of this mammal. Method The study employed immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR), and Western blot (WB) to obtain the results. Results Ngb and Hif-1α were significantly (P<0.05) expressed in the cerebellar cortex, piriform lobe, medulla, and corpus callosum of the adult yak while in the young yak brain tissues, the protein expressions were significantly found in the white matter of the cerebellum, pineal gland, corpus callosum, and cerebellar cortex. The Ngb and Hif-1α expression showed similarities and differences. This may have resulted from similar animal species, source of nutrition, age factors, brain size, emotional activities, and communication. The findings documented that Ngb and Hif-1α are commonly expressed in various adult and young yak brain tissues. Multiple roles in the brain tissues of the adult and young yaks are involved in the expression and distribution and are proposed to play a significant role in the adaptation of the yak to the high altitude environment. Conclusion This study provides meaningful data to understand the adaptive mechanism to hypoxia and recommended researchers to expand on the adaptive mechanism and brain tissues that are not recorded.

Resumo Contexto O cérebro é um órgão que funciona como o centro do sistema nervoso em todos os animais vertebrados e na maioria dos invertebrados. Objetivo O estudo examinou a expressão de neuroglobina (Ngb) e fator-1α indutível por hipóxia (Hif-1α) em tecidos cerebrais de iaques adultos e jovens e forneceu aos pesquisadores uma visão significativa da anatomia, fisiologia e bioquímica desse mamífero. Método O estudo utilizou imuno-histoquímica (IHC), PCR quantitativo em tempo real (qRT-PCR) e western blot (WB) para a obtenção dos resultados. Resultados Ngb e Hif-1α foram significativamente (P < 0,05) expressos no córtex cerebelar, lobo piriforme, medula e corpo caloso do iaque adulto, enquanto nos tecidos cerebrais do iaque jovem as expressões proteicas foram encontradas significativamente na substância branca do cerebelo, glândula pineal, corpo caloso e córtex cerebelar. A expressão de Ngb e Hif-1α apresentou semelhanças e diferenças. Isso pode ter resultado de espécies animais semelhantes, fonte de nutrição, fatores de idade, tamanho do cérebro, atividades emocionais e comunicação. Os resultados documentaram que o Ngb e o Hif-1α são comumente expressos em vários tecidos cerebrais de iaques adultos e jovens. Múltiplos papéis nos tecidos cerebrais de iaques adultos e jovens estão envolvidos na expressão e distribuição e são propostos para desempenhar um papel significativo na adaptação do iaque ao ambiente de alta altitude. Conclusão Este estudo fornece dados significativos para compreender o mecanismo adaptativo à hipóxia e recomendou que os pesquisadores expandissem o mecanismo adaptativo e os tecidos cerebrais que não foram registrados.

Editorial for Special Issue: Neuroglobin from Brain Protection to Cancer Progression.

Since its discovery in 2000 [...].

The X-ray crystal structure of human A15C neuroglobin reveals both native/de novo disulfide bonds and unexpected ligand-binding sites.

Human neuroglobin (Ngb) contains a heme group and three Cys residues (Cys46, Cys55, and Cys120) in the polypeptide chain. By introducing an additional Cys at position 15, the X-ray structure of A15C Ngb mutant was solved at a high resolution of 1.35 Å, which reveals the formation of both the native (C46C55) and the engineered (C15C120) disulfide bonds, likely playing a functional and structural role, respectively, according to the geometry analysis. Unexpectedly, 1,4-dioxane from the crystallization reagents was bound not only to the protein surface, but also to the heme distal pocket, providing insights into protein-ligand interactions for the globin and guiding the design of functional heme enzymes.

Carbon Monoxide-Neuroglobin Axis Targeting Metabolism Against Inflammation in BV-2 Microglial Cells.

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.

Overexpression of Neuroglobin Promotes Energy Metabolism and Autophagy Induction in Human Neuroblastoma SH-SY5Y Cells.

Neuroglobin (NGB) is an O2-binding globin mainly expressed in the central and peripheral nervous systems and cerebrospinal fluid. Previously, it was demonstrated that NGB overexpression protects cells from hypoxia-induced death. To investigate processes promoted by NGB overexpression, we used a cellular model of neuroblastoma stably overexpressing an NGB-FLAG construct. We used a proteomic approach to identify the specific profile following NGB overexpression. To evaluate the role of NGB overexpression in increasing energetic metabolism, we measured oxygen consumption rate (OCR) and the extracellular acidification rate through Seahorse XF technology. The effect on autophagy induction was evaluated by analyzing SQSTM1/p62 and LC3-II expression. Proteomic analysis revealed several differentially regulated proteins, involved in oxidative phosphorylation and integral mitochondrial proteins linked to energy metabolism. The analysis of mitochondrial metabolism demonstrated that NGB overexpression increases mitochondrial ATP production. Indeed, NGB overexpression enhances bioenergetic metabolism, increasing OCR and oxygen consumption. Analysis of autophagy induction revealed an increase of LC3-II together with a significant decrease of SQSTM1/p62, and NGB-LC3-II association during autophagosome formation. These results highlight the active participation of NGB in several cellular processes that can be upregulated in response to NGB overexpression, playing a role in the adaptive response to stress in neuroblastoma cells.

Effect of Dexmedetomidine on The Neuroglobin Expression in Elderly Patients With Minimally Invasive Coronary Artery Bypass Graft Surgery.

BACKGROUND: To study the effect of dexmedetomidine (Dex) on the expression of Neuroglobin (Ngb) and postoperative cognitive function in elderly patients undergoing minimally invasive coronary artery bypass surgery. METHODS: Forty patients, who underwent elective minimally invasive off-pump coronary artery bypass grafting in our hospital from January 2018 to December 2019, were randomly divided into the Dex group (N = 20) and control group (N = 20). Venous blood samples were taken to determine the expression level of Ngb in both groups. Mini mental status examination (MMSE) was used to detect the cognitive function of patients. RESULTS: The expression level of Ngb in the Dex group was significantly higher than that in the control group at 6h after one-lung ventilation and postoperative 24h (P < .01). The MMSE score of the Dex group was significantly higher than the control group at postoperative 7 days and postoperative 30 days (P < .01). Although with no statistical significance, the MMSE score of the Dex group was higher than the control group at postoperative 90 days (P > .05). The incidence of postoperative cognitive dysfunction (POCD) in the Dex group was significantly lower than that in the control group at postoperative 7 days and postoperative 30 days (P < .05). CONCLUSION: Dex used in elderly patients undergoing minimally invasive coronary artery bypass graft surgery can effectively increase the expression level of Ngb and reduce the incidence of POCD.

Neuroglobin effectively halts vision loss in Harlequin mice at an advanced stage of optic nerve degeneration.

Mitochondrial diseases are among the most prevalent groups of inherited neurological disorders, affecting up to 1 in 5000 adults. Despite the progress achieved on the identification of gene mutations causing mitochondrial pathologies, they cannot be cured so far. Harlequin mice, a relevant model of mitochondrial pathology due to apoptosis inducing factor depletion, suffer from progressive disappearance of retinal ganglion cells leading to optic neuropathy. In our previous work, we showed that administering adeno-associated virus encompassing the coding sequences for neuroglobin, (a neuroprotective molecule belonging to the globin family) or apoptosis-inducing factor, before neurodegeneration onset, prevented retinal ganglion cell loss and preserved visual function. One of the challenges to develop an effective treatment for optic neuropathies is to consider that by the time patients become aware of their handicap, a large amount of nerve fibers has already disappeared. Gene therapy was performed in Harlequin mice aged between 4 and 5 months with either a neuroglobin or an apoptosis-inducing factor vector to determine whether the increased abundance of either one of these proteins in retinas could preserve visual function at this advanced stage of the disease. We demonstrated that gene therapy, by preserving the connectivity of transduced retinal ganglion cells and optic nerve bioenergetics, results in the enhancement of visual cortex activity, ultimately rescuing visual impairment. This study demonstrates that: (a) An increased abundance of neuroglobin functionally overcomes apoptosis-inducing factor absence in Harlequin mouse retinas at a late stage of neuronal degeneration; (b) The beneficial effect for visual function could be mediated by neuroglobin localization to the mitochondria, thus contributing to the maintenance of the organelle homeostasis.

Role of Neuroglobin in the Neuroprotective Actions of Estradiol and Estrogenic Compounds.

Estradiol exerts neuroprotective actions that are mediated by the regulation of a variety of signaling pathways and homeostatic molecules. Among these is neuroglobin, which is upregulated by estradiol and translocated to the mitochondria to sustain neuronal and glial cell adaptation to injury. In this paper, we will discuss the role of neuroglobin in the neuroprotective mechanisms elicited by estradiol acting on neurons, astrocytes and microglia. We will also consider the role of neuroglobin in the neuroprotective actions of clinically relevant synthetic steroids, such as tibolone. Finally, the possible contribution of the estrogenic regulation of neuroglobin to the generation of sex differences in brain pathology and the potential application of neuroglobin as therapy against neurological diseases will be examined.

Neuroglobin: A New Possible Marker of Estrogen-Responsive Breast Cancer.

The expression of the α-subtype of Estrogen Receptor (ERα) characterizes most breast cancers (more than 75%), for which endocrine therapy is the mainstay for their treatment. However, a high percentage of ERα+ breast cancers are de novo or acquired resistance to endocrine therapy, and the definition of new targets for improving therapeutic interventions and the prediction of treatment response is demanding. Our previous data identified the ERα/AKT/neuroglobin (NGB) pathway as a common pro-survival process activated in different ERα breast cancer cell lines. However, no in vivo association between the globin and the malignity of breast cancer has yet been done. Here, we evaluated the levels and localization of NGB in ERα+ breast ductal carcinoma tissue of different grades derived from pre-and post-menopausal patients. The results indicate a strong association between NGB accumulation, ERα, AKT activation, and the G3 grade, while no association with the menopausal state has been evidenced. Analyses of the data set (e.g., GOBO) strengthen the idea that NGB accumulation could be linked to tumor cell aggressiveness (high grade) and resistance to treatment. These data support the view that NGB accumulation, mainly related to ER expression and tumor grade, represents a compensatory process, which allows cancer cells to survive in an unfavorable environment.

Proteomic and Bioinformatic Investigation of Altered Pathways in Neuroglobin-Deficient Breast Cancer Cells.

Neuroglobin (NGB) is a myoglobin-like monomeric globin that is involved in several processes, displaying a pivotal redox-dependent protective role in neuronal and extra-neuronal cells. NGB remarkably exerts its function upon upregulation by NGB inducers, such as 17ß-estradiol (E2) and H2O2. However, the molecular bases of NGB's functions remain undefined, mainly in non-neuronal cancer cells. Human MCF-7 breast cancer cells with a knocked-out (KO) NGB gene obtained using CRISPR/Cas9 technology were analyzed using shotgun label-free quantitative proteomics in comparison with control cells. The differential proteomics experiments were also performed after treatment with E2, H2O2, and E2 + H2O2. All the runs acquired using liquid chromatography-tandem mass spectrometry were elaborated within the same MaxQuant analysis, leading to the quantification of 1872 proteins in the global proteomic dataset. Then, a differentially regulated protein dataset was obtained for each specific treatment. After the proteomic study, multiple bioinformatics analyses were performed to highlight unbalanced pathways and processes. Here, we report the proteomic and bioinformatic investigations concerning the effects on cellular processes of NGB deficiency and cell treatments. Globally, the main processes that were affected were related to the response to stress, cytoskeleton dynamics, apoptosis, and mitochondria-driven pathways.

Plasma S100ß and neuron-specific enolase, but not neuroglobin, are associated with early cognitive dysfunction after total arch replacement surgery: A pilot study.

ABSTRACT: To investigate whether plasma concentrations of S100ß protein, neuron-specific enolase (NSE), and neuroglobin (NGB) correlate with early postoperative cognitive dysfunction (POCD) in patients undergoing total arch replacement.This prospective study analyzed 40 patients who underwent total arch replacement combined with stented elephant trunk implantation at our hospital between March 2017 and January 2019. Cognitive function was assessed using the Mini-mental State Examination (MMSE) preoperatively, on the day after extubation and on day 7 after surgery. Plasma levels of S100ß, NSE, and NGB POCD were assayed preoperatively and at 1, 6, and 24 hours after cardiopulmonary bypass. POCD was defined as a decrease of at least 1 unit in the MMSE score from before surgery until day 7, and patients were stratified into those who experienced POCD or not. The 2 groups were compared in clinicodemographic characteristics and plasma levels of the 3 proteins.Plasma levels of all 3 biomarkers increased significantly during and after cardiopulmonary bypass. Levels of S100ß and NSE, but not NGB, were significantly higher in the 15 patients who showed POCD than in the remainder who did not. For prediction of early POCD, S100ß showed an area under the receiver operating characteristic curve (AUC) of 0.71 (95% confidence interval [CI] 0.55-0.87), sensitivity of 48%, and specificity of 87%. The corresponding values for NSE were 0.77 (95%CI 0.60-0.94), 92%, and 67%. Together, S100ß and NSE showed an AUC of 0.81 (95%CI 0.66-0.96), sensitivity of 73%, and specificity of 80%. NGB did not significantly predict early POCD (AUC 0.62, 95%CI 0.43-0.80).Plasma S100ß protein and NSE, but not NGB, may help predict early POCD after total arch replacement.