Fucoxanthin regulates Nrf2/Keap1 signaling to alleviate myocardial hypertrophy in diabetic rats / 南方医科大学学报

OBJECTIVE@#To investigate the protective effect of fucoxanthin (FX) against diabetic cardiomyopathy and explore the underlying mechanism.@*METHODS@#Rat models of diabetes mellitus (DM) induced by intraperitoneal injection of streptozotocin (60 mg/kg) were randomized into DM model group, fucoxanthin treatment (DM+FX) group and metformin treatment (DM+ Met) group, and normal rats with normal feeding served as the control group. In the two treatment groups, fucoxanthin and metformin were administered after modeling by gavage at the daily dose of 200 mg/kg and 230 mg/kg, respectively for 12 weeks, and the rats in the DM model group were given saline only. HE staining was used to examine the area of cardiac myocyte hypertrophy in each group. The expression levels of fibrotic proteins TGF-β1 and FN proteins in rat hearts were detected with Western blotting. In the cell experiment, the effect of 1 μmol/L FX on H9C2 cell hypertrophy induced by exposure to high glucose (HG, 45 mmol/L) was evaluated using FITC-labeled phalloidin. The mRNA expression levels of the hypertrophic factors ANP, BNP and β-MHC in H9C2 cells were detected using qRT-PCR. The protein expressions of Nrf2, Keap1, HO-1 and SOD1 proteins in rat heart tissues and H9C2 cells were determined using Western blotting. The DCFH-DA probe was used to detect the intracellular production of reactive oxygen species (ROS).@*RESULTS@#In the diabetic rats, fucoxanthin treatment obviously alleviated cardiomyocyte hypertrophy and myocardial fibrosis, increased the protein expressions of Nrf2 and HO-1, and decreased the protein expressions of Keap1 in the heart tissue (P < 0.05). In H9C2 cells with HG exposure, fucoxanthin significantly inhibited the enlargement of cell surface area, lowered the mRNA expression levels of ANP, BNP and β-MHC (P < 0.05), promoted Nrf2 translocation from the cytoplasm to the nucleus, and up-regulated the protein expressions its downstream targets SOD1 and HO-1 (P < 0.05) to enhance cellular antioxidant capacity and reduce intracellular ROS production.@*CONCLUSION@#Fucoxanthin possesses strong inhibitory activities against diabetic cardiomyocyte hypertrophy and myocardial fibrosis and is capable of up-regulating Nrf2 signaling to promote the expression of its downstream antioxidant proteins SOD1 and HO-1 to reduce the level of ROS.

Receptores metabotrópicos de glutamato e sua relação com a Esclerose Lateral Amiotrófica (ELA) / Glutamate metabotropic receptors and its relationship with Amiotrophic Lateral Sclerosis (ALS)

A Esclerose Lateral Amiotrófica (ELA), uma doença neurodegenerativa fatal, que afeta neurônios motores superiores e inferiores, tem como fisiopatologia mais aceita a excitotoxicidade mediada por glutamato. O atual estudo tem como objetivo estabelecer a relação entre esse neurotransmissor e a ELA, a partir de uma revisão de literatura nas bases de dados Pubmed e Medline. O glutamato é o principal neurotransmissor do Sistema Nervoso Central (SNC) e a excitotoxicidade gerada pelo seu acúmulo nas fendas sinápticas é tida como um dos principais mecanismos envolvidos na fisiopatologia da ELA. Os indivíduos afetados pela ELA apresentam diminuição da expressão de determinados grupos de receptores metabotrópicos de glutamato (mGlu) nos neurônios e nas células da glia desses pacientes. Os mGlu possuem um papel de destaque na modulação da excitotoxicidade por glutamato e são subdivididos em três grupos. Os mGlus do grupo 1 amplificam as transmissões sinápticas excitatórias rápidas, e os dos grupos 2 e 3 atuam como neuroprotetores inibindo a liberação do glutamato na fenda sináptica. Os mGlus são, portanto, considerados alvos terapêuticos para a atuação de drogas que combatem a excitotoxicidade e induzem a produção de fatores neurotróficos, constituindo importante atuação no combate à ELA.

Amyotrophic Lateral Sclerosis (ALS), a fatal neurodegenerative disease that affects upper and lower motor neurons, has as the most accepted pathophysiology the glutamate-mediated excitotoxicity. The present study aims to establish the relationship between this neurotransmitter and ALS, based on a literature review in the PubMed and Medline databases. Glutamate is the main neurotransmitter of the central nervous system (CNS) and the excitotoxicity generated by its accumulation in the synaptic clefts is considered one of the main mechanisms involved in the pathophysiology of ALS. People affected by ALS present a decrease in expression of certain metabotropic glutamate receptor (mGlu) groups in neurons and glial cells of these patients. mGlu has a prominent role in modulating glutamate excitotoxicity and are subdivided into three groups. Group 1 mGlu amplifies rapid excitatory synaptic transmissions, while groups 2 and 3 act as neuroprotective agents, since among other functions they inhibit glutamate release into the synaptic cleft. Finally, mGlu are considered therapeutic targets for the action of drugs that fight excitotoxicity and induce the production of neurotrophic factors, constituting an important action in the fight against ALS.

Induced pluripotent stem cell-derived motor neurons from amyotrophic lateral sclerosis (ALS) patients carrying different superoxide dismutase 1 mutations recapitulate pathological features of ALS / 中华医学杂志(英文版)

BACKGROUND@#Investigations of the pathogenic mechanisms in motor neurons (MNs) derived from amyotrophic lateral sclerosis (ALS) disease-specific induced pluripotent stem (iPS) cell lines could improve understanding of the issues affecting MNs. Therefore, in this study we explored mutant superoxide dismutase 1 (SOD1) protein expression in MNs derived from the iPS cell lines of ALS patients carrying different SOD1 mutations.@*METHODS@#We generated induced pluripotent stem cell (iPSC) lines from two familial ALS (FALS) patients with SOD1-V14M and SOD1-C111Y mutations, and then differentiated them into MNs. We investigated levels of the SOD1 protein in iPSCs and MNs, the intracellular Ca2+ levels in MNs, and the lactate dehydrogenase (LDH) activity in the process of differentiation into the MNs derived from the controls and ALS patients' iPSCs.@*RESULTS@#The iPSCs from the two FALS patients were capable of differentiation into MNs carrying different SOD1 mutations and differentially expressed MN markers. We detected high SOD1 protein expression and high intracellular calcium levels in both the MN and iPSCs that were derived from the two SOD1 mutant patients. However, at no time did we observe stronger LDH activity in the patient lines compared with the control lines.@*CONCLUSIONS@#MNs derived from patient-specific iPSC lines can recapitulate key aspects of ALS pathogenesis, providing a cell-based disease model to further elucidate disease pathogenesis and explore gene repair coupled with cell-replacement therapy. Incremental mutant expressions of SOD1 in MNs may have disrupted MN function, either causing or contributing to the intracellular calcium disturbances, which could lead to the occurrence and development of the disease.

Identification of a novel SOD1 variant in a Chinese patient with amyotrophic lateral sclerosis / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese patient with amyotrophic lateral sclerosis (ALS).@*METHODS@#Peripheral blood samples were collected from the patient and his parents for the extraction of genomic DNA. Genetic variant was identified by whole exome sequencing. Candidate variant was verified by Sanger sequencing of his parents and healthy controls.@*RESULTS@#The patient was found to harbor a heterozygous c.420C>G (p.Asn140Lys) variant of the SOD1 gene. The same variant was not detected in his parents and 100 healthy controls. The variant has not been included in HGMD, dbSNP and other databases.@*CONCLUSION@#The c.420C>G variant of the SOD1 gene may underlie the ALS in this patient. Above finding has enriched the spectrum of SOD1 gene variants.

Achados clínicos, histopatológicos e moleculares da mielopatia degenerativa canina: relato de caso / Clinical, histopathological and molecular findings of canine degenerative myelopathy: case report

Objetivou-se descrever os achados clínicos, histopatológicos e moleculares associados à MDC em um cão da raça Pastor-Suiço. O cão possuía uma paraparesia progressiva em membros pélvicos e foi submetido a avaliações clínicas, pelas quais se obteve, entre outros diferenciais, o diagnóstico presuntivo de MDC. Com a evolução dos sinais, o tutor optou pela eutanásia. Os achados histopatológicos da medula espinhal foram compatíveis com uma degeneração segmentar axonal e mielínica. O diagnóstico molecular foi realizado por meio da extração do DNA obtido por swab oral. Uma PCR foi otimizada utilizando-se primers descritos em literatura para amplificar a região do gene SOD1. A amostra foi, então, submetida a sequenciamento unidirecional, que revelou que o animal em questão era homozigoto para o alelo A para a mutação c.118G>A no éxon 2 do gene SOD1. O diagnóstico clínico presuntivo da MDC no presente caso foi esclarecido por meio dos achados histopatológicos, associados aos achados clínicos, e da sua caracterização molecular. Ressalta-se a contribuição deste relato, que traz aspectos clínicos, histopatológicos e moleculares associados à MDC na raça Pastor-Suíço, para a qual, até o presente momento, na literatura consultada, não há relato dessa enfermidade.(AU)

The objective of this study was to describe the clinical, histopathological and molecular findings associated with MDC in a Swiss Shepherd dog. The dog had a progressive paraparesis in pelvic limbs and was submitted to clinical evaluations where, among other differentials, the presumptive diagnosis of MDC was obtained. With the progression of the nervous deficits tutor opted for euthanasia. The histopathological findings of the spinal cord were compatible with axonal and myelinic segmental degeneration. Molecular diagnosis was performed by extracting the DNA obtained by oral swab. PCR was optimized using primers described in the literature to amplify the SOD1 gene region. The sample was then subjected to one-way sequencing which revealed that the animal in question was homozygous for the A allele for the c.118G>A mutation in exon 2 of the SOD1 gene. The presumptive diagnosis of MDC in the present case was clarified by histopathological findings, as well as by its molecular characterization. The contribution of this report brings clinical, histopathological and molecular aspects associated with canine degenerative myelopathy in the Swiss Shepherd breed, that until this moment, in the literature consulted, there is no report of this disease in the breed mentioned.(AU)

miR-9-1 gene methylation and DNMT3B (rs2424913) polymorphism may contribute to periodontitis

Abstract Genetic and epigenetic changes have been associated with periodontitis in various genes; however, little is known about genes involved in epigenetic mechanisms and in oxidative stress. Objective: This study aims to investigate the association of polymorphisms C677T in MTHFR (rs1801133) and −149C→T in DNMT3B (rs2424913), as well as the methylation profiles of MTHFR, miR-9-1, miR-9-3, SOD1, and CAT with periodontitis. The association between polymorphisms and DNA methylation profiles was also analyzed. Methodology: The population studied was composed of 100 nonsmokers of both sexes, divided into healthy and periodontitis groups. Genomic DNA was extracted from the epithelial buccal cells, which were collected through a mouthwash. Polymorphism analysis was performed through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), while methylation-specific PCR (MSP) or combined bisulfite restriction analysis techniques were applied for methylation analysis. Results: For DNMT3B, the T allele and the TT genotype were detected more frequently in the periodontitis group, as well as the methylated profile on the miR-9-1 promoter region. There was also a tendency towards promoter region methylation on the CAT sequence of individuals with periodontal disease. Conclusion: The polymorphism −149C→T in DNMT3B (rs2424913) and the methylated profile of the miR-9-1 promoter region are associated with periodontitis.

Genetic approach in amyotrophic lateral sclerosis

The superoxide dismutase type 1 (SOD1) gene is the first responsible gene mapped in amyotrophic lateral sclerosis type 1 (ALS1), and it codes for the enzyme SOD1, the function of which is to protect against damage mediated by free radicals deriving from oxygen. Its pathophysiological mechanism in ALS1 is related to ischemia. Several molecular studies of the SOD1 gene show that point mutations are the most frequent. The most common mutations in familial cases are p.A4V, p.I113Y, p.G37R, p.D90A and p.E100G, which account for more than 80% of cases, although intronic mutations have also been described as responsible for ALS1. Sporadic cases are explained by mutations in other genes such as SETX and C9orf72. ALS1 is a complex disease with genetic heterogeneity. On the other hand, familial and sporadic cases have a different etiology, which is explained by molecular heterogeneity and multiple pathogenic mechanisms that lead to ALS1; oxidative stress and ischemia are not the only cause. In Mexico, ALS molecular genetics studies are scarce. Clinical studies show an increase in cytokines such as adipsin in cerebrospinal fluid.

Baroreflex Control of Heart Rate in Mice Overexpressing Human SOD1: Functional Changes in Central and Vagal Efferent Components / 神经科学通报·英文版

Excessive reactive oxygen species (ROS) (such as the superoxide radical) are commonly associated with cardiac autonomic dysfunctions. Though superoxide dismutase 1 (SOD1) overexpression may protect against ROS damage to the autonomic nervous system, superoxide radical reduction may change normal physiological functions. Previously, we demonstrated that human SOD1 (hSOD1) overexpression does not change baroreflex bradycardia and tachycardia but rather increases aortic depressor nerve activity in response to arterial pressure changes in C57B6SJL-Tg (SOD1)2 Gur/J mice. Since the baroreflex arc includes afferent, central, and efferent components, the objective of this study was to determine whether hSOD1 overexpression alters the central and vagal efferent mediation of heart rate (HR) responses. Our data indicate that SOD1 overexpression decreased the HR responses to vagal efferent nerve stimulation but did not change the HR responses to aortic depressor nerve (ADN) stimulation. Along with the previous study, we suggest that SOD1 overexpression preserves normal baroreflex function but may differentially alter the functions of the ADN, vagal efferents, and central components. While SOD1 overexpression likely enhanced ADN function and the central mediation of bradycardia, it decreased vagal efferent control of HR.

Efeito de aldeídos de colesterol na esclerose lateral amiotrófica: estudo em modelo animal e na agregação da SOD1 in vitro / Effect of secosterol aldehydes on Amyotrophic Lateral Sclerosis: study in animal model and SOD1 aggregation in vitro

Aldeídos de colesterol (Secosterol A e Secosterol B) têm sido detectados em amostras de cérebro humano e investigados em modelos de doenças neurodegenerativas como possíveis marcadores e intermediários do processo patológico. Estes oxisteróis constituem uma classe de eletrófilos derivados de lipídeos que podem modificar e induzir agregação de proteínas. A esclerose lateral amiotrófica (ELA) é um distúrbio neurodegenerativo associado ao acúmulo de agregados imunorreativos de superóxido dismutase (Cu, Zn-SOD, SOD1). O objetivo deste trabalho foi avaliar a presença de aldeídos de colesterol em ratos modelo ELA e sua capacidade de induzir a formação de agregados de SOD1 in vitro. Aldeídos de colesterol foram analisados no plasma, medula espinhal e córtex motor de ratos ELA. Uma quantidade elevada de Secosterol B foi detectada no córtex motor desses ratos em comparação com animais controle. Adicionalmente, os experimentos in vitro mostraram que Secosterol B e Secosterol A induziram a agregação da SOD1 em uma forma amiloidogênica que se liga à tioflavina T. Esta agregação não foi observada com o colesterol e os seus hidroperóxidos. Usando aldeídos de colesterol marcados com grupo alquinil e um ensaio de click chemistry, foi observado que os agregados de SOD1 estão ligados covalentemente aos aldeídos. A modificação covalente da proteína foi confirmada por análise de MALDI-TOF, que mostrou a adição de até cinco moléculas de aldeídos de colesterol à proteína por base de Schiff. Curiosamente, a análise comparativa com outros eletrófilos derivados de lipídeos (e.g. HHE e HNE) demonstrou que a agregação de SOD1 aumentou proporcionalmente à hidrofobicidade dos aldeídos, observando-se a maioragregação com aldeídos de colesterol. Os sítios de modificação da SOD1 foram caracterizados por nanoLC-MS/MS após digestão da proteína com tripsina, onde foram identificadas lisinas como o principal aminoácido modificado. Em geral, nossos dados mostram que a oxidação do colesterol que leva à produção de aldeídos de colesterol é aumentada no cérebro de ratos ELA e que os aldeídos altamente hidrofóbicos derivados de colesterol podem promover eficientemente modificação e agregação de SOD1

Secosterol aldehydes (Secosterol B and Secosterol A) have been detected in human brain samples and investigated in models of neurodegenerative diseases as possible markers and intermediates of the pathological process. These oxysterols constitute a class of lipid-derived electrophiles that can modify and induce aggregation of proteins. Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder associated with the accumulation of immunoreactive aggregates of superoxide dismutase (Cu, Zn-SOD, SOD1). The objective of this work is to evaluate the presence of secosterol aldehydes in ALS rats and their ability to induce formation of SOD1 aggregates in vitro. Secosterol aldehydes were analyzed in plasma, spinal cord and motor cortex of ALS rats. A higher amount of Secosterol B was detected in the motor cortex of these rats compared to control animals. In addition, in vitro experiments have shown that Secosterol B and Secosterol A induce aggregation of SOD1 into an amyloidogenic form that binds to thioflavin T. This aggregation was not apparent in incubations with cholesterol and its hydroperoxides. Using alkynyl-labeled secosterol aldehydes and a click chemistry assay, it was found that the SOD1 aggregates are covalently linked to the aldehydes. Covalent modification of the protein was confirmed by MALDI-TOF analysis, which showed the addition of up to five molecules of secosterol aldehydes to the protein by Schiff base formation. Interestingly, the comparative analysis with other lipid-derived electrophiles (e.g. HHE and HNE) demonstrated that the aggregation of SOD1 increased according to the hydrophobicity of the aldehydes. Compared to the other electrophiles, a higher SOD1 aggregation was observed with secosterol aldehydes. SOD1 modification sites were characterized by nanoLC-MS/MS afterprotein digestion with trypsin, revealing lysine as the major amino acid modified in these experiments. Collectively, our data show that cholesterol oxidation leads to the production of secosterol aldehydes, which are increased in the brain of ALS rats, and that these highly hydrophobic aldehydes can efficiently promote the modification and aggregation of SOD1

Terminalia arjuna bark extract attenuates picrotoxin-induced behavioral changes by activation of serotonergic, dopaminergic, GABAergic and antioxidant systems / 中国天然药物

Stress and emotion are associated with several illnesses from headaches to heart diseases and immune deficiencies to central nervous system. Terminalia arjuna has been referred as traditional Indian medicine for several ailments. The present study aimed to elucidate the effect of T. arjuna bark extract (TA) against picrotoxin-induced anxiety. Forty two male Balb/c mice were randomly divided into six experimental groups (n = 7): control, diazepam (1.5 mg·kg), picrotoxin (1 mg·kg) and three TA treatemt groups (25, 50, and 100 mg/kg). Behavioral paradigms and PCR studies were performed to determine the effect of TA against picrotoxin-induced anxiety. The results showed that TA supplementation increased locomotion towards open arm (EPM) and illuminated area (light-dark box test), and increased rearing frequency (open field test) in a dose dependent manner, compared to picrotoxin (P < 0.05). Furthermore, TA increased number of licks and shocks in Vogel's conflict. PCR studies showed an up-regulation of several genes, such as BDNF, IP, DL, CREB, GABA, SOD, GPx, and GR in TA administered groups. In conclusion, alcoholic extract of TA bark showed protective activity against picrotoxin in mice by modulation of genes related to synaptic plasticity, neurotransmitters, and antioxidant enzymes.

CRISPR/Cas9-mediated targeted gene correction in amyotrophic lateral sclerosis patient iPSCs

Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disease with cellular and molecular mechanisms yet to be fully described. Mutations in a number of genes including SOD1 and FUS are associated with familial ALS. Here we report the generation of induced pluripotent stem cells (iPSCs) from fibroblasts of familial ALS patients bearing SOD1 and FUS mutations, respectively. We further generated gene corrected ALS iPSCs using CRISPR/Cas9 system. Genome-wide RNA sequencing (RNA-seq) analysis of motor neurons derived from SOD1 and corrected iPSCs revealed 899 aberrant transcripts. Our work may shed light on discovery of early biomarkers and pathways dysregulated in ALS, as well as provide a basis for novel therapeutic strategies to treat ALS.

Shielding of the geomagnetic field reduces hydrogen peroxide production in human neuroblastoma cell and inhibits the activity of CuZn superoxide dismutase

Accumulative evidence has shown the adverse effects of a geomagnetic field shielded condition, so called a hypomagnetic field (HMF), on the metabolic processes and oxidative stress in animals and cells. However, the underlying mechanism remains unclear. In this study, we evaluate the role of HMF on the regulation of cellular reactive oxygen species (ROS) in human neuroblastoma SH-SY5Y cells. We found that HMF exposure led to ROS decrease, and that restoring the decrease by additional HO rescued the HMF-enhanced cell proliferation. The measurements on ROS related indexes, including total anti-oxidant capacity, HO and superoxide anion levels, and superoxide dismutase (SOD) activity and expression, indicated that the HMF reduced HO production and inhibited the activity of CuZn-SOD. Moreover, the HMF accelerated the denaturation of CuZn-SOD as well as enhanced aggregation of CuZn-SOD protein, in vitro. Our findings indicate that CuZn-SOD is able to response to the HMF stress and suggest it a mediator of the HMF effect.

Increased orexin expression promotes sleep/wake disturbances in the SOD1-G93A mouse model of amyotrophic lateral sclerosis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Sleep/wake disturbances in patients with amyotrophic lateral sclerosis (ALS) are well-documented, however, no animal or mechanistic studies on these disturbances exist. Orexin is a crucial neurotransmitter in promoting wakefulness in sleep/wake regulation, and may play an important role in sleep disturbances in ALS. In this study, we used SOD1-G93A transgenic mice as an ALS mouse model to investigate the sleep/wake disturbances and their possible mechanisms in ALS.</p><p><b>METHODS</b>Electroencephalogram/electromyogram recordings were performed in SOD1-G93A transgenic mice and their littermate control mice at the ages of 90 and 120 days, and the samples obtained from these groups were subjected to quantitative reverse transcriptase-polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>For the first time in SOD1-G93A transgenic mice, we observed significantly increased wakefulness, reduced sleep time, and up-regulated orexins (prepro-orexin, orexin A and B) at both 90 and 120 days. Correlation analysis confirmed moderate to high correlations between sleep/wake time (total sleep time, wakefulness time, rapid eye movement [REM] sleep time, non-REM sleep time, and deep sleep time) and increase in orexins (prepro-orexin, orexin A and B).</p><p><b>CONCLUSION</b>Sleep/wake disturbances occur before disease onset in this ALS mouse model. Increased orexins may promote wakefulness and result in these disturbances before and after disease onset, thus making them potential therapeutic targets for amelioration of sleep disturbances in ALS. Further studies are required to elucidate the underlying mechanisms in the future.</p>

Hippophae rhamnoides L. leaves extract enhances cell proliferation and neuroblast differentiation through upregulation of intrinsic factors in the dentate gyrus of the aged gerbil / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Hippophae rhamnoides L. (HL) exerts antioxidant activities against various oxidative stress conditions. In this study, we investigated effects of extract from HL leaves (HLE) on cell proliferation and neuroblast differentiation in the subgranular zone (SGZ) of the dentate gyrus (DG) of aged gerbils.</p><p><b>METHODS</b>Aged gerbils (24 months) were divided into vehicle (saline)-treated- and HLE-treated-groups. The vehicle and HLE were orally administered with 200 mg/kg once a day for 20 days before sacrifice. Cell proliferation and neuroblast differentiation were examined in the DG using Ki67 and doublecortin (DCX), respectively. We also observed changes in immunoreactivities of superoxide dismutase 1 (SOD1) and superoxide dismutase 2 (SOD2), brain-derived neurotrophic factor (BDNF), and phospho-glycogen synthase kinase-3-beta (p-GSK-3β) to examine their relation with neurogenesis using immunohistochemistry.</p><p><b>RESULTS</b>The administration of HLE significantly increased the number of Ki67-positive cells and DCX-positive neuroblasts with well-developed processes in the SGZ of the DG of the HLE-treated-group. In addition, immunoreactivities of SOD1, SOD2, BDNF, and p-GSK-3β were significantly increased in granule and polymorphic cells of the DG in the HLE-treated-group compared with those in the vehicle-treated-group.</p><p><b>CONCLUSIONS</b>HLE treatment significantly increased cell proliferation and neuroblast differentiation, showing that immunoreactivities of SOD1, SOD2, BDNF, and p-GSK-3β were significantly increased in the DG. These indicate that increased neuroblast differentiation neurogenesis may be closely related to upregulation of SOD1, SOD2, BDNF, and p-GSK-3β in aged gerbils.</p>

Neuroprotection via maintenance or increase of antioxidants and neurotrophic factors in ischemic gerbil hippocampus treated with tanshinone I / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Danshen (Radix Salvia miltiorrhizae) has been used as a traditional medicine in Asia for treatment of various microcirculatory disturbance related diseases. Tanshinones are mainly hydrophobic active components, which have been isolated from Danshen and show various biological functions. In this study, we observed the neuroprotective effect of tanshinone I (TsI) against ischemic damage in the gerbil hippocampal CA1 region (CA1) after transient cerebral ischemia and examined its neuroprotective mechanism.</p><p><b>METHODS</b>The gerbils were divided into vehicle-treated-sham-group, vehicle-treated-ischemia-group, TsI-treated-sham-group, and TsI-treated-ischemia-group. TsI was administrated intraperitoneally three times (once a day for three days) before ischemia-reperfusion. The neuroprotective effect of TsI was examined using H&E staining, neuronal nuclei (NeuN) immunohistochemistry and Fluoro-Jade B staining. To investigate the neuroprotective mechanism of TsI after ischemia-reperfusion, immunohistochemical (IHC) and Western blotting analyses for Cu, Zn-superoxide dismutase (SOD1), Mn-superoxide dismutase (SOD2), brain-derived neurotrophic factor (BDNF) and insulin-like growth factor-I (IGF-I) were performed.</p><p><b>RESULTS</b>Treatment with TsI protected pyramidal neurons from ischemia-induced neuronal death in the CA1 after ischemia-reperfusion. In addition, treatment with TsI maintained the levels of SOD1 and SOD2 as determined by IHC and Western blotting in the CA1 after ischemia-reperfusion compared with the vehicle-ischemia-group. In addition, treatment with TsI increased the levels of BDNF and IGF-I determined by IHC and Western blotting in the TsI-treated-sham-group compared with the vehicle-treated-sham-group, and their levels were maintained in the stratum pyramidale of the ischemic CA1 in the TsI-treated-ischemia-group.</p><p><b>CONCLUSION</b>Treatment with TsI protects pyramidal neurons of the CA1 from ischemic damage induced by transient cerebral ischemia via the maintenance of antioxidants and the increase of neurotrophic factors.</p>

Avaliação do efeito do ácido docosahexaenoico e de seus hidroperóxidos na oligomerização de SOD1 em um modelo da doença esclerose lateral amiotrófica / Evaluation of the effect of docosahexaenoic acid and its hydroperoxides in oligomerization of SOD1 in a model of the disease amyotrophic lateral sclerosis

A Esclerose Lateral Amiotrófica (ELA) é uma doença progressiva e fatal causada pela degeneração seletiva dos neurônios motores do cérebro e medula. Dos casos familiares de ELA (fELA), 20% são causados por mutações pontuais no gene da sod1. O ácido docosahexaenoico (C22:6, n-3, DHA) é um ácido graxo altamente insaturado, sendo um dos principais ácidos graxos da massa cinzenta do cérebro. Estudos têm correlacionado mutações de SOD1 com a formação de agregados que poderiam ser induzidos por ácidos graxos insaturados. O objetivo deste estudo foi avaliar os efeitos e mecanismos do DHA e de seus hidroperóxidos (DHAOOH) na agregação de SOD1 in vitro. As análises de dicroísmo circular (CD) mostraram mudanças na estrutura secundária de ambas as proteínas apo-SOD1WT e G93A promovidas pelo DHA, resultando em aumento de superfície hidrofóbica e formação de estruturas do tipo beta-amilóide, como mostrado pelos ensaios do bis- ANS e Tioflavina, respectivamente. Estas mudanças resultam na formação de agregados amorfos como observado por microscopia eletrônica de varredura (MEV). Espécies de alto peso molecular foram observadas nas incubações do DHA com as formas apo da SOD1 por SDS-PAGE sob condições não redutoras e também por cromatografia de exclusão por tamanho. A formação dos agregados mostrou-se dependente de resíduos de Cys na sua forma desprotonada, visto que agregados não foram observados na presença de beta-mercaptoetanol e sua formação foi inibida na presença de bloqueador de tióis e em pH ácido. Além disso, análises por cromatografia de exclusão mostraram que a agregação é dependente da insaturação e conformação cis dos ácidos graxos. Comparativamente ao DHA, os hidroperóxidos do DHA tiveram um efeito menor na agregação de SOD1, porém revelaram a propriedade de induzir a dimerização covalente de SOD1. No geral, os dados mostram que o DHA induz a agregação de SOD1, através de um processo envolvendo a exposição de superfícies hidrofóbicas, formação de pontes dissulfeto e também de possíveis cross-links envolvendo reações do tipo "ene-tiol"

ALS is a progressive and fatal disease caused by selective degeneration of motor neurons in the brain and spinal cord. Twenty percent of familial ALS (fALS) cases are caused mainly by point mutations in the sod1 gene. Docosahexaenoic acid (C22:6, n-3, DHA) is a highly unsaturated fatty acid, wich is one of the main fatty acids in the cerebral gray matter. Studies have linked SOD1 mutations to the formation of aggregates that could be induced by unsaturated fatty acids. The aim of this study was to evaluate the effect of DHA on aggregation of SOD1 fALS mutants in vitro and its mechanisms. CD analysis shows changes in the secondary structure of both apo-SOD1WT and G93A promoted by DHA resulting in an increase in the surface hydrophobicity and formation of structures such as beta amyloid, which was also confirmed by bis-ANS assay and Thioflavin, respectively. These changes enhance the interaction of SOD1 and DHA, leading to amorphous aggregates as revealed by FESEM. Incubation of DHA with apo-SOD1 forms results in high-molecular weight species as detected by SDS-PAGE analyses under non-reducing conditions and also by size exclusion chromatography. This appears to require Cys residues in their thiolate forms because high aggregates are not observed under reducing conditions and also by size exclusion chromatography or at acidic pH. Also, size-exclusion chromatography indicates that the mutant apo-SOD1 aggregation is dependent on the unsaturation and cis-conformation of fatty acids. Compared to the DHA, DHAOOH had a minor effect on SOD1 aggregation, however revealed the ability to induce covalent dimerization of SOD1. Overall, the data suggest a mechanism of DHA aggregation, by a process involving exposure to hydrophobic surfaces, formation of disulfide bonds and also for possible cross-links involving reactions such "thiol-ene"

Effects of noise exposure level on the relationship between SNPs of SOD1 and the susceptibility to noise-induced hearing loss (NIHL) / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the effects of noise exposure level and cumulative noise exposure (CNE) on the relationship between rs2070424 and rs10432782 SNPs in SOD1 and the susceptibility to noise-induced hearing loss (NIHL).</p><p><b>METHODS</b>A case-control study was performed for investigating the effects of environmental risk factors on the susceptibility to NIHL in 201 sensitive workers and 202 resistant workers.A questionnaire was utilized to investigate the occupational health and to identify the occupational risk factors. The noise exposure levels were detected according to the Chinese standard Measurement of noise in the workplace (GBZ/T 189.8-2007). The peripheral blood samples (5 ml blood for each sample) were from sensitive workers and resistant workers. Genomic DNA was extracted on the basis of the standard procedures of Takara kit. SNPs were detected using standard procedures of TaqMan probe allele identification method.</p><p><b>RESULTS</b>In group exposed to 85 - 92 dB noise (A), the risk of NIHL in the subjects with the AA genotype of rs2070424 was lower than that in the subjects with the GG genotype, OR = 0.37 (95%CI: 0.17∼ 0.80). In group exposed to > 82 dB CNE (A), the AA genotype of rs2070424 is a protective factor of NIHL, as compared with the GG genotype, OR = 0.25 (95%CI: 0.09 ∼ 0.70). In group exposed to 85 - 92 dB noise (A), the risk of NIHL in the subjects with the GG genotype of rs10432782 was compared with the risk of NIHL in the subjects with the TT genotype, OR = 3.17 (95%CI: 1.16 ∼ 6.89). The GT genotype was compared with TT genotype, OR = 2.39 (95%CI: 1.16 ∼ 4.97). In group exposed to 75 ∼ 82 dB CNE (A), the risk of NIHL in the subjects with the GG genotype was compared with the risk of NIHL in the subjects with the TT genotype, OR = 2.35 (95%CI: 0.96 ∼ 5.72), P = 0.06. The GG genotype may bea risk factor of NIHJ.</p><p><b>CONCLUSION</b>The noise exposure level and CNE may influence the relationship between rs2070424, rs10432782 SNPs in SOD1 and noise-induced hearing loss.</p>

Association between SNPs in SOD1 and noise-induced hearing loss in Chinese Han population / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the association between SNPs in SOD1 (rs1041740, rs2070424, rs10432782 and rs4998557) and noise-induced hearing loss in Chinese Han population.</p><p><b>METHODS</b>A case-control study was used to study the effects of environmental risk factors on the susceptibility to noise induced hearing loss (NIHL) in 201 sensitive workers and 202 resistant workers. A questionnaire was designed to carry out an investigation, and an occupational health survey was used to identify the occupational risk factors. Genomic DNA was extracted from peripheral blood cells using standard procedures of Takara kit, and 5 ml blood was from each subject. SNPs were detected using standard procedures of TaqMan probe allele identification method.</p><p><b>RESULTS</b>In SOD1 gene, the A allele of rs2070424 was a protective factor of NIHL, compared with the G allele (OR = 0.67, 95%CI: 0.50 approximately 0.88). The risk with NIHL in subjects with AA genotype was significantly lower than that in subjects with GG genotype (OR = 0.48, 95%CI: 0.26 approximately 0.79). After adjusting the confusion factors, OR was 0.44 and 95%CI was 0.25 approximately 0.78.</p><p><b>CONCLUSION</b>In Chinese Han population, the SNP of rs2070424 in SOD1 may be associated with the susceptibility to NIHL.</p>

Design of functional small interfering RNAs targeting amyotrophic lateral sclerosis-associated mutant alleles / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>RNA interference (RNAi) is a potential cure for amyotrophic lateral sclerosis (ALS) caused by dominant, gain-of-function superoxide dismutase 1 (SOD1) mutations. The success of such therapy relies on the functional small interfering RNAs (siRNAs) that can effectively deliver RNAi. This study aimed to design the functional siRNAs targeting ALS-associated mutant alleles.</p><p><b>METHODS</b>A modified dual luciferase system containing human SOD1 mRNA target was established to quantify siRNA efficacy. Coupled with validated siRNAs identified in the literature, we analyzed the rationale of siRNA design and subsequently developed an asymmetry rule-based strategy for designing siRNA. We then further tested the effectiveness of this design strategy in converting a naturally symmetric siRNA into functional siRNAs with favorable asymmetry for gene silencing of SOD1 alleles.</p><p><b>RESULTS</b>The efficacies of siRNAs could vary tremendously by one base-pair position change. Functional siRNAs could target the whole span of SOD1 mRNA coding sequence as well as non-coding region. While there is no distinguishable pattern of the distribution of nucleobases in these validated siRNAs, the high percent of GC count at the last two positions of siRNAs (P18 and P19) indicated a strong effect of asymmetry rule. Introducing a mismatch at position 1 of the 5' of antisense strand of siRNA successfully converted the inactive siRNA into functional siRNAs that silence SOD1 with desired efficacy.</p><p><b>CONCLUSIONS</b>Asymmetry rule-based strategy that incorporates a mismatch into siRNA most consistently enhances RNAi efficacy and guarantees producing functional siRNAs that successfully silence ALS-associated SOD1 mutant alleles regardless target positions. This strategy could also be useful to design siRNAs for silencing other disease-associated dominant, gain-of-function mutant genes.</p>

Copper (Cu2+) induces degeneration of dopaminergic neurons in the nigrostriatal system of rats / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To study the effects of intranigral injection of different doses of CuSO4.5H2O on dopaminergic neuron in the nigrostriatal system of rats.</p><p><b>METHODS</b>Wistar rats were divided into four groups, including control group, 10 nmol, 50 nmol and 200 nmol copper injected into left substantia nigra (SN) groups. Seven days after the intranigral injection of copper, dopamine (DA) contents in the striatum (Str) were measured by high performance lipid chromotophotography (HPLC); the density of tyrosine hydroxylase (TH) positive axons in the Str was measured by TH staining method; TH and Caspase-3 mRNA expression in the SN were measured by semi-quantitative RT-PCR. We detected the activity of superoxide dismutase (SOD) in the lesioned midbrain of rats using biochemical methods.</p><p><b>RESULTS</b>DA and its metabolites contents had no significant difference between control group and low dose (10 nmol) copper group. But from 50 nmol copper group, DA contents in the lesioned sides were reduced with the increase in the copper doses injected, showing a significant linear correlation (F = 34.16, P < 0.01). In the 50 nmol copper group, TH positive axons in the Str decreased compared with those of the control and unlesioned sides (F = 121.9, P < 0.01). In the 50 nmol copper group, TH mRNA expression decreased (t = 3.12, P < 0.01) while Caspase-3 mRNA expression increased (t = 8.96, P < 0.01) in the SN compared with the control. SOD activity decreased in the midbrain of rats treated with 50 nmol copper compared with that of the control (t = 2.33, P < 0.01).</p><p><b>CONCLUSION</b>Copper could induce damage of dopaminergic neurons in the SN of rats through destroying antioxidant defenses and promoting apoptosis.</p>