Human manganese superoxide dismutase (hMn-SOD) cDNA was amplified by RT-PCR from total RNA of human liver cell (L02), and cloned into yeast expression vector pPIC9K containing AOX1 promoter and the alpha-factor signal peptide sequence. The resultant pPIC9K-MnSOD was transformed to P. pastoris GS115, screened for Mut+ carrying multiple copies of hMn-SOD. The positive transformants were fermented in flasks and induced by 0.5% methanol. After 4 days of methanol induction, the expressed hMn-SOD was up to 32% of the total proteins in the supernatant by SDS-PAGE with specific activity of 247.7 u/mg.
Cloning, Molecular ; DNA, Complementary ; biosynthesis ; genetics ; Humans ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Superoxide Dismutase ; biosynthesis ; genetics

BACKGROUNDSleep/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.

METHODSElectroencephalogram/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.

RESULTSFor 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).

CONCLUSIONSleep/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.

Amyotrophic Lateral Sclerosis ; genetics ; metabolism ; Animals ; Female ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Male ; Mice ; Mice, Transgenic ; Neuropeptides ; genetics ; metabolism ; Orexins ; Reverse Transcriptase Polymerase Chain Reaction ; Sleep ; physiology ; Superoxide Dismutase ; genetics ; metabolism ; Superoxide Dismutase-1 ; Wakefulness ; physiology

Antioxidant enzymes fused with cell-penetrating peptides could enter cells and protect cells from irradiation damage. However, the unselective transmembrane ability of cell-penetrating peptide may also bring antioxidant enzymes into tumor cells, thus protecting tumor cells and consequently reducing the efficacy of radiotherapy. There are active matrix metalloproteinase (MMP)-2 or MMP-9 in most tumor cellular microenvironments. Therefore, a fusion protein containing an MMP-2/9 cleavable substrate peptide X, a cell-penetrating peptide R9, a glutathione S-transferase (GST), and a human Cu, Zn superoxide dismutase (SOD1), was designed and named GST-SOD1-X-R9. In the tumor microenvironment, GST-SOD1-X-R9 would lose its cell-penetrating peptide and could not enter tumor cells due to the cleavage of substrate X by active MMP-2/9, thereby achieving selected entering normal cells. The complete nucleotide sequence of SOD1-X-R9 was synthesized and inserted into the prokaryotic expression vector pGEX-4T-1. The pGEX4T-1-SOD1-X-R9 recombinant plasmid was obtained, and soluble expression of the fusion protein was achieved. GST-SOD1-X-R9 was purified by ammonium sulfate precipitation and GST affinity chromatography. The molecular weight of the fusion protein was approximately 47 kDa, consistent with the theoretical value. The SOD and GST activities were 2 954 U/mg and 328 U/mg, respectively. Stability test suggested that almost no change in either SOD activity or GST activity of GST-SOD1-X-R9 was observed under physiological conditions. The fusion protein could be partially digested by collagenase Ⅳ in solution. Subsequently, the effect of MMP-2/9 activity on transmembrane ability of the fusion protein was tested using 2D and 3D cultured HepG2 cells. Little extracellular MMP-2 activity of HepG2 cells was observed under 2D culture condition. While under the 3D culture model, the size and the MMP-2 activity of the HepG2 tumor spheroid increased daily. GST-SOD1-R9 proteins showed the same transmembrane efficiency in 2D cultured HepG2 cells, but the transmembrane efficiency of GST-SOD1-X-R9 in 3D cultured HepG2 spheres was reduced remarkably. This study provided a basis for further investigating the selectively protective effect of GST-SOD1-X-R9 against oxidative damage in normal cells.
Ammonium Sulfate ; Antioxidants ; Cell-Penetrating Peptides/pharmacology* ; Endopeptidases ; Glutathione Transferase/metabolism* ; Humans ; Matrix Metalloproteinase 2/genetics* ; Matrix Metalloproteinase 9/genetics* ; Recombinant Fusion Proteins ; Recombinant Proteins ; Superoxide Dismutase/metabolism* ; Superoxide Dismutase-1

OBJECTIVETo study the associations between paraoxonase, 55 Met/Leu (PON1 55 Met/ Leu), paraoxonase2 148 Ala/Gly (PON2 148 Ala/Gly) and manganese superoxide dismutase 9 Ala/Val (MnSOD 9 Ala/Val) genetic polymorphisms and coronary heart disease (CHD), plasma activities of paraoxonase (PON), total superoxide dismutase (T-SOD), MnSOD, as well as plasma concentration of maleic dialdehyde (MDA).

METHODSUsing PCR-RFLP method to identify genotype of PON1 55 Met/Leu, PON2 148 Ala/Gly and MnSOD 9 Ala/Val genetic polymorphisms, and using colorimetry to detect plasma activities of PON, T-SOD, MnSOD and plasma concentration of MDA in 262 CHD patients and 100 controls.

RESULTSCompared with controls, the plasma activities of PON [(349.27 +/- 138.36 vs. 454.75 +/- 166.00) nmol x min(-1) x ml(-1), P < 0.001], T-SOD [(23.61 +/- 16.51 vs. 44.01 +/- 22.68) U/ml, P < 0.001] and MnSOD [(21.56 +/- 13.11 vs. 28.79 +/- 8.65) U/ml, P < 0.001] reduced obviously,while plasma MDA concentration increased markedly [(2.47 +/- 0.73 vs. 2.15 +/- 0.55)nmol/ml, P < 0.01] in CHD patients. There were more LM genotype and Met allele of PON, 55 Met/Leu (24.8% vs. 1.4%, P < 0.001 and 12.4% vs. 0.5%, P = 0.001, respectively), GG and AG genotype and G allele of PON2 148 Ala/Gly (11.8% vs. 5.0%, P < 0.001, 48.1% vs. 24.0%, P < 0.001 and 36.0% vs. 17.0%, P < 0.001, respectively) and AA genotype, A allele of MnSOD 9 Ala/Val genetic polymorphisms (64.2% vs. 43.0%, P = 0.001 and 80.0% vs. 67.0%, P = 0.014, respectively) in CHD patients than in controls. The activities of plasma PON and T-SOD were lower in individuals with PON1 55 LM genotype than those with LL genotype. The activity of plasma PON was also lower in individuals with PON2 148 GG/AG genotype than those with AA genotype. The activities of plasma PON and MnSOD depressed in individuals with MnSOD AA genotype compared with those with VV genotype. Logistic regression analysis demonstrated that PON1 55 LM genotype, PON2 148 GG/AG genotype and G allele were independent risk factors for CHD.

CONCLUSIONThe antioxidative ability decreased, while lipid superoxide increased in CHD patients. Gene polymorphisms of PON1 55 Met/Leu, PON2 148 Ala/Gly and MnSOD 9 Ala/Val seemed to involve in the morbidity of CHD by influencing the plasma activities of PON and MnSOD.

Aryldialkylphosphatase ; genetics ; metabolism ; Case-Control Studies ; China ; Coronary Disease ; enzymology ; genetics ; Genotype ; Humans ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length ; Superoxide Dismutase ; genetics ; metabolism

The total RNA was extracted from ginseng leaves of Panax ginseng. The Cu/Zn-SOD gene was amplified via RT-PCR and the pET-28(a)-Cu/Zn-SOD expression vector was constructed. The pET-28 (a)-Cu/Zn-SOD recombinant plasmid was transformed into Escherichia coli BL21 (DE3) competent cells and was induced by IPTG in order to select optimal induction of expression conditions. The target protein was purified by the nickel ions (Ni ) affinity chromatography and the target protein enzyme activity was determinated by the xanthine oxidase method. The similarity of the Cu/Zn-SOD gene sequences and the Cu/Zn-SOD gene sequences of Korean ginseng in NCBI was 99. 00%. The target protein expression level was about 44.42%, and the molecular weight was 16.30 kDa after the pET-28(a)-Cu/Zn-SOD recombinants were induced by IPTG. The purified Cu/Zn-SOD protease activity reached 10,596.69 U x mg(-1). The P. ginseng pET-28(a)-Cu/Zn-SOD prokaryotic expression vector was built by the method of molecular biology, which provided the foundation for studying the Cu/Zn-SOD biology function.
Cloning, Molecular ; Escherichia coli ; genetics ; Gene Expression ; Genetic Engineering ; methods ; Genetic Vectors ; genetics ; Panax ; enzymology ; genetics ; Sequence Analysis ; Superoxide Dismutase ; genetics ; isolation & purification ; metabolism

Overexpression of recombinant Human Cu, Zn-Superoxide Dismutase (rhCu, Zn-SOD) in E. coli results in the form of insoluble inclusion body. Purity of rhSOD inclusion body was over 80% by isolation and purification. After preliminary renaturation by conventional dilution or dialysis, enzyme preparations was respectively purified by using Copper Metals-Chelating Affinity Chromatography (Copper-MCAC). RhSOD specific activity purified by MCAC (from the sample renatured partly by dialysis) was 2.2 times as much as that by dialysis and protein recovery was 64%. RhSOD specific activity purified by MCAC (from the sample renatured partly by dilution) was 5.3 times as much as that by dilution and protein recovery was 25%. The two rhSOD preparations purified by MCAC had specific activities about 5000 u/mg and activity recoveries were all over 130% of the enzyme activities in the samples renatured partly by dilution or dialysis. The above-mentioned results indicated that Copper-MCAC resulted in a purification and further renaturation of target protein. SDS-PAGE showed that the target protein rhSOD (19 kD) was purified homogeneously and NBT activity identification proved that the purified and renatured rhSOD had very strong SOD activity. In conclusion, Copper Metals-Chelaing Affinity Chromatography appears to be a simple, rapid and efficient procedure for purifying and further renaturing rhCu, Zn-SOD by dilution or dialysis. The method provided a new idea for purifying and renaturing recombinant proteins expressed in the form of inclusion body in E. coli.
Chelating Agents ; chemistry ; Chromatography, Affinity ; methods ; Escherichia coli ; genetics ; metabolism ; Humans ; Inclusion Bodies ; genetics ; Protein Renaturation ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification ; Superoxide Dismutase ; biosynthesis ; genetics

OBJECTIVETo evaluate the effects of Attractin (Atrn) silence on the anti-oxidative and anti-apoptotic abilities of TM4 Sertoli cells and its influence on the expressions of superoxide dismutase (SOD) and caspase6 in the cells.

METHODSWe observed the apoptotic indexes of TM4 Sertoli cells with normal expression (control), partial deletion, and complete deletion of the Atrn gene (psiRNA-TM4, psiAtrn-TM4, and mu-SC). We determined the mRNA and protein expressions of SOD and caspase6 by Q-PCR and Western blot, measured the SOD activity and malondialdehyde (MDA) contentby spectrophotometry, and detected the apoptotic index of the cells by TUNEL.

RESULTSCompared with psiRNA-TM4, after inhibition of the Atrn expression, the Sertoli cells in the psiAtrn-TM4 and mu-SCgroups showed significantly decreased expressions ofSOD mRNA (70.76% and 92.58%) and protein (65.11% and 71.0%) (both P < 0.05). The levels of caspase 6 mRNA and protein were increased 5.28 and 3.40 times in the psiAtrn-TM4 and 2.97 and 2.50 times in the mu-SCgroup as compared with the normal control (both P < 0.05). Atrn deletion markedly increased the apoptotic indexes of the cells in the psiAtrn-TM4 and mu-SC groups by 16.22% and 22.03% (P < 0.05) and reduced the activity of SOD by 23.00% and 39.37% (P < 0.05); it also elevated the level of MDA by 155.22% (P < 0.05).

CONCLUSIONThe Atrn gene exerts influence on the function of Sertoli cells in multiple ways, in which antioxidative stress and apoptosis regulation may play an important role.

Animals ; Apoptosis ; Caspase 6 ; metabolism ; Cells, Cultured ; Gene Deletion ; Male ; Membrane Proteins ; genetics ; metabolism ; Mice ; Oxidative Stress ; Sertoli Cells ; metabolism ; pathology ; Superoxide Dismutase ; metabolism

Animals ; Antioxidants ; pharmacology ; Fatigue ; prevention & control ; Male ; Mice ; Physical Exertion ; physiology ; Random Allocation ; Recombinant Proteins ; genetics ; metabolism ; pharmacology ; Superoxide Dismutase ; genetics ; metabolism ; pharmacology ; Swimming ; physiology

OBJECTIVETo investigate the protective effect of manganese superoxide dismutase (MnSOD) gene transfer to small intestinal epithelial cells from radiation injury.

METHODSHerpes simplex virus (HSV) vector containing both the human MnSOD and GFP genes was introduced into mouse small intestine. Expression of MnSOD by the intestinal villi was confirmed by nested RT-PCR, immunofluorescence and enzyme activity assay. Mice were then given various doses of irradiation over the abdomen. The height of intestinal villi was measured on histopathology sections by SZ-PT optical system before irradiation, 24 h and 72 h post-irradiation. All comparisons were performed by one-way analysis of variance using the SPSS statistical software to analyze the significance between groups.

RESULTSNested RT-PCR, immunofluorescence and enzyme activity assay of MnSOD demonstrated overexpression and increased activity of MnSOD in the inoculated intestine of mice. Control (sham inoculated) irradiated mice showed decreased villi height by 40.1%-59.3% on day 1 and 44.2%-65.1% on day 3 (7.5-15 Gy). Treatment of mice with HSV-MnSOD prior to radiation led to statistically significant radioprotection of the small bowel with mean villi height decreased by only 3.1%-12.4% on day 1 and 6.3%-29.1% on day 3.

CONCLUSIONThe results demonstrate that overexpression of human MnSOD via a replication defective herpes simplex viral vector is an effective method to protect the small intestine from damage caused by ionizing radiation.

Animals ; Epithelial Cells ; metabolism ; Genetic Therapy ; Genetic Vectors ; Intestine, Small ; metabolism ; Mice ; Radiation Injuries, Experimental ; prevention & control ; Simplexvirus ; genetics ; Superoxide Dismutase ; genetics ; Transfection

OBJECTIVETo study the effect of SOD2 and its C47T mutation on oxidative injury in cochlea hair cells.

METHODSHEI-OC1 cells were transfected with the SOD2 of Ala16 and Vla16. Cells' proliferation ability was determined by MTT assay. The intracellular SOD2 activities were detected by xanthine oxidase method. Intracellular ROS were determined by DCFH-DA after exposure to 100 µmol/L t-BHP and the early apoptotic and necrotic rate or late apoptotic rate were quantified by flow cytometry (FCM) using Annexin V/PI double staining.

RESULTSMTT method showed the transfection of SOD2 gene and empty plasmid did not affect the proliferation capacity. SOD2 vitality in Ala(16) and Val(16) SOD2 transfected cells increased 2.51 and 2.71 times respectively (P < 0.01), but the difference between the two transfection groups was not statistically significant (P > 0.05). After exposed to t-BHP, the majority of the untransfected and empty plasmid transfected cells sent '++' class bright fluorescence, while in Ala(16) and Val(16) SOD2 transfected groups, only about half cells sent '±' ∼ '+' level fuzzy fluorescence. determination of FCM suggested the early apoptotic and necrotic rate or late apoptotic rate decreased after SOD2 transfection (P < 0.01), but the difference between the two genotypes of SOD2 was not statistically significant (P > 0.05).

CONCLUSIONHigh expression of SOD2 below 3.71 times can reduce intracellular ROS level in HEI-OC1 cells, while SOD2 C47T mutation had no effect on them. SOD2 can be considered as NIHL susceptibility gene and its rs4880 SNP may be not directly related to NIHL genetic susceptibility.

Cell Line ; Cochlea ; metabolism ; Hair Cells, Auditory ; metabolism ; Humans ; Mutation ; Oxidative Stress ; Polymorphism, Single Nucleotide ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; genetics