Apelin-13 Prevents the Delayed Neuropathy Induced by Tri-ortho-cresyl Phosphate Through Regulation the Autophagy Flux in Hens.

Organophosphate-induced delayed neuropathy (OPIDN) is pathologically characterized by the swollen axon containing aggregations of microtubules, neurofilaments, smooth endoplasmic reticulum and multivesicular vesicles. At present, the exact mechanism of OPIDN is unclear and the effective therapeutic methods is not available to counter this syndrome. Recent studies had shown that the autophagy was involved in OPIDN. The adipocytokine Apelin is a peptide, Apelin and its receptor are abundantly expressed in the nervous system. Recent researches illuminated that Apelin was neuroprotective factor and Apelin could regulate the autophagy in vivo and vitro model. So we investigated the effect of Apelin-13 on the OPIDN induced by Tri-ortho-cresyl phosphate (TOCP) in hens and explored the role of autophagy in Apelin-13 preventing OPIDN. Adult Roman hens were given a single dose of 750 mg/kg TOCP by gavage for 21 days to induce OPIDN, and neural dysfunction were detected, and the formation of autophagosomes in spinal cord neurons was observed by transmission electron microscopy, and the molecular markers of autophagy microtubule-associated protein light chain-3 (LC3) and the autophagy substrates p62/SQSTM1 were determined by Western blot analysis. The results demonstrated that the obvious neurological dysfunction such as hindlimb paralysis and paralysis of gait was present, the number of autophagosomes in the neurons of spinal cords was significantly increased, the level of LC3-II and p62 expressions and the ratio of LC3-II/LC3-I in spinal cords and sciatic nerve were significantly increased in the OPIDN model group compared with the control group. Compared with the OPIDN model group, the neurological dysfunction of tens was obviously reduced, the clinical signs scores was significantly decreased, the number of autophagosomes in the neurons of hen spinal cords was significantly decreased, the level of LC3-II and p62 expressions and the ratio of LC3-II/LC3-I in spinal cords and sciatic nerve were significantly decreased in Apelin-13 treatment group. Our results suggested that Apelin-13 prevented against the OPIDN induced by TOCP in hens, which the mechanism might be associated with regulation autophagy flux by Apelin-13.

Role of aldehyde dehydrogenase 2 in 1-methy-4-phenylpyridinium ion-induced aldehyde stress and cytotoxicity in PC12 cells.

Aldehyde stress contributes to molecular mechanisms of cell death and the pathogenesis of Parkinson's disease (PD). The neurotoxin 1-Methy-4-Phenylpyridinium Ion (MPP(+)) is commonly used to model PD. Aldehyde dehydrogenase 2 (ALDH2) is an important enzyme detoxifying aldehydes. The aim of this study is to evaluate whether MPP(+)-induced neurotoxicity is involved in aldehyde stress by modulation of ALDH2. Our results demonstrated that treatment of PC12 cells with MPP(+) leads to aldehyde stress by increasing in loads of malondialdehyde and 4-hydroxynonenal, which indicated that MPP(+)-induced aldehyde stress contributes to its cytotoxicity in PC12 cells. We also showed that MPP(+) up-regulates the expression and activity of ALDH2 in PC12 cells and that inhibition of ALDH2 by its specific inhibitor daidzin prevents MPP(+)-induced decrease in cell viability and increases in apoptosis, oxidative stress and aldehyde stress in PC12 cells. These findings suggest that aldehyde stress contributes to MPP(+)-induced toxicity in PC12 cells by upregulation of ALDH2. This study provides a novel insight into the role of ALDH2 in the neurotoxicity of MPP(+).

Association of Aldehyde Dehydrogenase 2 Gene Polymorphism with Myocardial Infarction.

OBJECTIVE: This study explored the correlation between myocardial infarction (MI) and the Glu504Lys polymorphism in the aldehyde dehydrogenase 2 (ALDH2) gene in the Qingyuan area. METHODS: The Glu504Lys polymorphism of the ALDH2 gene was analyzed using the polymerase chain reaction and deoxyribonucleic acid microarray analysis for 468 patients diagnosed with MI for the first time and 132 healthy subjects. RESULTS: There was a significant difference in the distribution of the ALDH2 genotype between the MI group and the control group (P = 0.0492), but there was no significant difference in allele frequency between the two groups (P = 0.1363). The clinical data showed that there were statistically significant differences (P < 0.05) in the two groups' gender and age distributions, rates of diabetes and hypertension, levels of alcohol and tobacco use, serological levels of heart markers, blood lipids and glucose. The subgroup analysis of ALDH2 genotypes found that alcohol consumption, high levels of myoglobin, and low levels of high-density lipoprotein cholesterol were significantly associated with a higher incidence of MI (P < 0.05). After adjusting for gender, hypertension, diabetes, and other related influencing factors, logistic regression analysis showed that the ALDH2 genotype GA/AA was an independent risk factor for MI (P < 0.05, OR = 1.479, 95% CI = 1.003-2.179). CONCLUSION: The presence of risk alleles with the genetic effect (ALDH2 genotype GA/AA) is an independent risk factor for MI.

LncRNA SNHG12 inhibits miR-199a to upregulate SIRT1 to attenuate cerebral ischemia/reperfusion injury through activating AMPK signaling pathway.

Cerebral ischemia caused severe disability, and associated with a series of neurological events. Long non-coding RNA SNHG12 was found to be upregulated in mouse brain microvascular endothelial cells by cerebral ischemia. Moreover, it was reported that SNHG12 could directly interact with miR-199a and sirtuin 1 (SIRT1) as a direct target of miR-199a in other diseases. However, the function and mechanism of SNHG12 in cerebral ischemia and reperfusion (I/R) injury of neuronal cells remains unclear. The present study was thus designed to explore the potential effect of SNHG12 and to investigate the underlying mechanism in I/R neuronal cells. we found that SNHG12 was upregulated in primary neuronal cells and N2a cells and peaked at 12 h and 24 h after OGD/R treatment, respectively. Meanwhile, MTT assay showed that knockdown SNHG12 inhibited cell proliferation under OGD/R condition. And flow cytometry analyses revealed more apoptosis rate was caused by SNHG12 knockdown. Mechanistically, SNHG12 interacted with miR-199a and decreased the expression of miR-199a. Overexpression miR-199a largely inhibited the cell proliferation and induced the cell apoptosis. Meanwhile, SNHG12 was proven to target miR-199a and then activated SIRT1 expression, which finally led to activation of AMPK signaling pathway. In summary, we demonstrate SNHG12 targets miR-199a to upregulate SIRT1 expression, which attenuates cerebral ischemia/reperfusion injury through AMPK pathway activation. Our findings provide molecular mechanism by which SNHG12 attenuates cerebral I/R injury and facilitate development of therapeautical strategies for treating ischemia-induced stroke.

Effect of hydrogen sulphide on beta-amyloid-induced damage in PC12 cells.

1. Hydrogen sulphide (H(2)S) is a well-known cytotoxic gas. Recently, H(2)S has been shown to protect neurons against oxidative stress caused by glutamate, peroxynitrite and HOCl. Considerably lower H(2)S levels have been reported in the brain of Alzheimer's disease (AD) patients with accumulation of beta-amyloid (A beta). 2. The aim of present study was to explore the cytoprotection by H(2)S against A beta(25-35)-induced apoptosis and the molecular mechanisms underlying this effect in PC12 cells. 3. Our findings indicated that A beta(25-35) significantly reduced cell viability and induced apoptosis of PC12 cells, along with dissipation of the mitochondrial membrane potential (MMP) and overproduction of reactive oxygen species (ROS). 4. Sodium hydrosulphide (NaHS), an H(2)S donor, protected PC12 cells against A beta(25-35)-induced cytotoxicity and apoptosis not only by reducing the loss of MMP, but also by attenuating the increase in intracellular ROS. 5. The results of the present study suggest that the cytoprotection by H(2)S is related to the preservation of MMP and attenuation of A beta(25-35)-induced intracellular ROS generation. These findings could significantly advance therapeutic approaches to the neurodegenerative diseases that are associated with oxidative stress, such as AD.

Neuroprotective effects of lentivirus-mediated cystathionine-beta-synthase overexpression against 6-OHDA-induced parkinson's disease rats.

Parkinson's disease (PD) is age-related neurodegenerative disorder by a progressive loss of dopaminergic(DA) neurons in the substantia nigra (SN) and striatum, which is at least partly associated with α-synuclein protein accumulation in these neurons. Hydrogen sulfide (H2S) plays an important role in the nervous system. Studies have shown that H2S has a protective effect on PD. However, as a kind of gas molecules, H2S is lively, volatile, and not conducive to scientific research and clinical application. Cystathionine-beta-synthase(CBS) is the main enzymes of synthesis of H2S in the brain. In order to examine the neuroprotective effects of CBS on PD, we detected the effects of CBS overexpression on 6-Hydroxydopamine (6-OHDA)-lesioned PD rats using lentivirus-mediated gene transfection techniques. In the injured SN of 6-OHDA-induced PD rats, the CBS expression and the endogenous H2S level markedly decreased, while administration of lentivirus-mediated CBS overexpression increased the CBS expression and the endogenous H2S production.CBS overexpression dramatically reversed apomorphine-induced rotation of the 6-OHDA model rats, decreased the number of TUNEL-positive neurons and the loss of the nigral DA neurons，specifically inhibited 6-OHDA-induced oxidase stress injury, and down-regulated the expression of α-synuclein(α-SYN) in the injured SN. NaHS (an H2S donor) had similar effects to CBS overexpression, while Amino-oxyacetate(AOAA, a CBS inhibitor) had opposite effects on PD rats. In summary, we demonstrated that CBS overexpression was able to provide neuroprotective on PD rats and improving the expression of CBS may be a potential therapeutic method for PD.

[Construction of a lentiviral vector carrying short?hairpin RNA targeting PAX6 and its effect on proliferation of glioma U251 cells in vitro].

OBJECTIVE: To construct a lentiviral vector for delivering short hairpin RNA (shRNA) targeting PAX6 and investigate its effect on the proliferation of glioma U251 cells in vitro. METHODS: Two small interfering RNA sequences targeting PAX6 gene were designed based on the reported sequence of PAX6 and annealed to form a double?stranded chain, which was inserted into a lentiviral vector to construct the recombinant lentiviral vector shRNA?PAX6. The recombinant vector was infected into U251 cells, and the expression of PAX6 mRNA and protein in the cells was detected by real?time PCR and Western blotting, respectively. The changes in the proliferation of U251 cells after the infection was assessed using MTT assay. RESULTS: Double enzyme digestion of the lentiviral vector pLKD?CMV?G&NR?U6?shRNA yielded an 8208?bp fragment, and colony PCR and sequencing analysis confirmed successful construction of the lentiviral vector shRNA?PAX6. Infection of the cells with shRNA?PAX6 caused a significant reduction of the expressions of PAX6 mRNA and protein (P<0.05) and resulted in obviously increased proliferation of U251 cells (P<0.05). CONCLUSION: We successfully constructed the recombinant vector shRNA?PAX6 for silencing PAX6 gene. PAX6 gene silencing results in increased proliferation of U251 cells in vitro.

[miRNA expression change of differentiation of mice marrow mesenchymal stem cells into adipocytes].

OBJECTIVE: To explore miRNA expression change of differentiation of mice marrow mesenchymal stem cells (MSCs) into adipocytes, which lay the foundation for further studies on molecular mechanism of miRNA regulating the differentiation of MSCs into adipocytes. METHODS: C57BL/6 mice MSCs were isolated, cultured through the whole bone marrow method, amplified by the differential adherent method. Cell growth was observed by morphology and the expression of superficial antigen CD29, CD44, CD34 were detected through immunohistochemistry. MSCs was induced to differentiation into adipocytes with adipocyte differentiation medium, and adipogenic differentiation of MSCs was analyzed by oil Red O staining. MicroRNA microarray was used to investigate the differentially expressed miRNAs in MSCs and adipocytes. RESULTS: (1) The fifth passage of MSCs had high purity under an inverted m icroscope. Immunohistochemistry staining showed that CD29, CD44 were positive and CD34 was negative in more than 90% MSCs. There were a large number of lipid droplets in cytoplasm after MSCs were induced with adipocyte differentiation medium, Oil O staining was positive. (2) The microarray experiment showed that 75 differentially expressed miRNAs were obtained in adipocytes compared with MSCs, 20 up-regulated and 55 down-regulated miRNAs were observed among them. CONCLUSION: There was a expression change of miRNA of differentiation of MSCs into adipocytes, some miRNAs might play important roles in MSCs adipogenic differentiation.

Hydrogen sulfide antagonizes homocysteine-induced neurotoxicity in PC12 cells.

Hydrogen sulfide (H2S) has been shown to protect neurons against oxidative stress. Lower levels of H(2)S as well as accumulation of homocysteine (Hcy), a strong risk of Alzheimer's disease (AD), are reported in the brains of AD patients. The aim of present study is to explore the protection of H2S against Hcy-induced cytotoxicity and apoptosis and the molecular mechanisms underlying in PC12 cells. We show that sodium hydrosulfide (NaHS), a H2S donor, protects PC12 cells against Hcy-mediated cytotoxicity and apoptosis by preventing both the loss of mitochondrial membrane potential (MMP) and the increase in intracellular reactive oxygen species (ROS) induced by Hcy. NaHS not only promotes the expression of bcl-2, but also blocks the down-regulation of bcl-2 by Hcy. These results indicate that H2S protects neuronal cells against neurotoxicity of Hcy by preserving MMP and attenuating ROS accumulation through up-regulation of bcl-2 level. Our study suggests a promising future of H2S-based therapies for neurodegenerative diseases such as AD.

Hydrogen sulfide inhibits MPP(+)-induced apoptosis in PC12 cells.

AIMS: Hydrogen sulfide (H2S) is a well-known cytotoxic gas. Recently it has been shown to protect neurons against oxidative stress caused by glutamate, hypochlorous acid (HOCl), and beta-amyloid. The aim of the present study is to explore the cytoprotection of H2S against 1-methyl-4-phenylpyridinium ion (MPP(+))-induced apoptosis and the molecular mechanisms underlying in PC12 cells, a rat cell line derived from pheochromocytoma cells. MAIN METHODS: Cell viability was determined by the conventional 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay. Apoptosis was assessed by Hoechst 33258 nuclear staining and flow cytometric (FCM) analysis after propidium iodide staining. The mitochondrial membrane potential (MMP) was measured by rhodamine 123 (Rh123) probe and reactive oxygen species (ROS) were measured by dihydrorhodamine probe using FCM analysis. KEY FINDINGS: MPP(+) reduced the cell viability and induced apoptosis of PC12 cells along with dissipation of MMP as well as overproduction of ROS. Sodium hydrosulfide (NaHS), a H2S donor, protected PC12 cells against MPP(+)-induced cytotoxicity and apoptosis not only by reducing the loss of MMP, but also by attenuating an increase in intracellular ROS. SIGNIFICANCE: H2S significantly protected PC12 cells against cytotoxicity and apoptosis induced by MPP(+), which was associated with the inhibition by H(2)S of MPP(+)-induced dissipation of MMP and overproduction of ROS. These findings can significantly advance therapeutic approaches to the neurodegenerative diseases which are associated with oxidative stress, such as Parkinson's disease.