Free radical hypothesis of aging emphasized that the age-related accumulation of free radicals results in cell injury. Alzheimer's disease (AD) is the most common form of neurodegenerative disease characterized by impaired cognition and memory of the elderly. Aging is a key risk factor in AD. Substantial evidence suggests that imbalance between free radical formation and clearance promotes AD pathogenesis. The brain overcomes oxidative stress by inducing expression of a set of genes called vitagenes. The protein products of vitagenes include heat shock proteins, heme oxygenases and thioredoxin systems, which serve as endogenous lifeguard of cells. This paper is a review of the expression and function of vitagenes in aging and AD brain, as well as relevant pharmacological study.
Aging ; genetics ; metabolism ; Alzheimer Disease ; genetics ; metabolism ; Brain ; metabolism ; Heat-Shock Proteins ; genetics ; metabolism ; Heme Oxygenase (Decyclizing) ; genetics ; metabolism ; Humans ; Oxidative Stress ; Thioredoxins ; genetics ; metabolism

Sptrx-1, 2 and 3 are a series of thioredoxins specifically expressed in the testis/sperm. They play a significant role structurally and functionally in the process of spermiogenesis. The genesis and mutation of sptrx-1, 2 and 3 are correlated to male reproduction. Taking sptrx-1, 2 and 3 as the target of study and treatment will open up a new field in the clinical study of male reproduction.
Humans ; Male ; Mutation ; Spermatogenesis ; genetics ; physiology ; Spermatozoa ; chemistry ; cytology ; metabolism ; Testis ; chemistry ; cytology ; metabolism ; Thioredoxins ; biosynthesis ; genetics ; physiology

Genetic modification of barley variety can be an efficient way to improve beer quality. The objective of this study was to understand the effect of trxS gene on hydrolases activities in transgenic and non-transgenic barley seeds. The results showed that alpha-amylase, free beta-amylase and limit dextrinase activity were increased in transgenic seeds in comparison with non-transgenic seeds. Sulfhydryl content of protein in transgenic seeds was also higher than that in non-transgenic seeds, suggesting that trxS gene could express in barley seeds, which opens a new way for breeding new barley varieties to improve beer quality.
Germination ; genetics ; Glucosyltransferases ; metabolism ; Hordeum ; enzymology ; genetics ; Plants, Genetically Modified ; enzymology ; genetics ; Seeds ; enzymology ; genetics ; Sulfhydryl Compounds ; metabolism ; Thioredoxins ; genetics ; alpha-Amylases ; metabolism ; beta-Amylase ; metabolism

We assessed the effects of trxS gene on changes of proteinase activity, contents of different protein fractions and SDS-PAGE profiles in germinating seeds of contrasting transgenic and nontransgenic barley variety. Proteinase activity was enhanced by 70.28% in transgenic than nontransgenic barley seeds, whereas contents of albumin, globulin, hordein and glutelin in transgenic seeds were 3.68%, 23.52%, 31.37%, and 21.04%, lower than those in nontransgenic seeds. Degradation rates of hordein and glutelin in transgenic seeds were faster than those in nontransgenic seedlings as indicated by the SDS-PAGE profiles. Our data imply that the transformation of trxS gene could promote the degradation of protein, providing theoretic basis for the use of trxS gene and barley quality breeding.
Germination ; Hordeum ; genetics ; growth & development ; metabolism ; Peptide Hydrolases ; metabolism ; Plant Proteins ; metabolism ; Plants, Genetically Modified ; genetics ; growth & development ; metabolism ; Seeds ; growth & development ; Thioredoxins ; genetics ; metabolism ; Transformation, Genetic

Adenovirus transfection technique was used in the current study to show if thioredoxin-interacting protein (TXNIP) overexpression can induce cell apoptosis and injury in H9C2 cardiomyocytes cultured in normal glucose condition. And the mechanisms were then investigated. Briefly, H9C2 cardiomyocytes in logarithmic growth phase were randomly divided into three groups: normal cultured group, empty adenovirus vector group (Ad-eGFP) and TXNIP overexpression group (Ad-TXNIP-eGFP). All cells were cultured in DMEM containing normal concentration of glucose (5 mmol/L) and lipid. 72 h after adenovirus transfection, cells and culture mediums were collected for further assay. The results showed that Ad-eGFP and Ad-TXNIP-eGFP adenovirus transfected H9C2 cells successfully, and the transfection efficiency reached the peak at 72 h. Compared with Ad-eGFP group, Ad-TXNIP-eGFP transfection significantly increased TXNIP mRNA (P < 0.05) and protein expression level (P < 0.01). TXNIP overexpression induced remarkable cell apoptosis and injury as evidenced by increased caspase-3 activity (P < 0.05), apoptotic rate (P < 0.01) and LDH activity (P < 0.01). To further analysis the mechanisms of TXNIP-induced cell apoptosis, we also determined Trx activity, Trx related free radical injury and p38 kinase activation, which are involved in free radical induced apoptosis. The results showed that, compared with those in Ad-eGFP group, Trx activity was significantly decreased (P < 0.01), while malondialdehyde (MDA), 3-nitrotyrosine contents and p38 kinase activity were significantly increased (P < 0.01) in TXNIP overexpression group. These results suggest that TXNIP overexpression alone can induce severe apoptosis and injury in H9C2 cardiomyocytes even they are cultured in normal glucose and lipid concentration conditions. The mechanism involved is that overexpressed TXNIP can bind and inhibit Trx, impairs its antioxidative and antiapoptotic function, and then increases free radical induced injury and p38 kinase dependent apoptosis.
Adenoviridae ; genetics ; Animals ; Apoptosis ; Carrier Proteins ; genetics ; metabolism ; Caspase 3 ; metabolism ; Cell Line ; Genetic Vectors ; Myocytes, Cardiac ; cytology ; Rats ; Thioredoxins ; metabolism

Pre-harvest sprouting of wheat is caused by a series of enzymes, in which alpha-amylase plays a key role. Thioredoxin (trx) is an important protein capable of reducing S-S to -SH. The authors transferred the anti-trxs gene into wheat ( Triticum aestivum L.) cultivar Wanmai 48 in 2000 in order to obtain a transgenic line with low activities of trx and alpha-amylase in wheat seeds to enhance their resistance to pre-harvest sprouting. In this work, a pair of specific anti-trxs primers were used in PCR test to validate the transgenic plants in T4 lines. A pair of primers of a wheat actin gene cDNA and a pair of trxs gene primers were used in the reverse transcription PCR test to measure the relative content of trx mRNA in the transgenic positive lines. The experiments of pre-harvest sprouting were carried out to test the resistance to pre-harvest sprouting. The results showed that there were 13 positive lines with the anti-trxs gene among 18 transgenic lines. In the maturity stage, the 8 relative contents of the trx mRNA in the 13 positive lines were reduced evidently (P < 0.01). The trx mRNA was correlated with the sprouting parameters significantly (r = 0.7181) . 6 lines with low trx mRNA showed stronger resistance to pre-harvest sprouting during the period from 30 days after anthesis to 10 days after maturity. Compared with non-transgenic plant (Wanmai 48, CK), the average sprouting time of these lines was postponed by 2.7 days (P < 0.01), the sprouting ratio of seeds on spikes and the spike sprouting degree were reduced by 35.5% (P < 0.01) and 47.5% (P < 0.01), respectively. However, 25 days after maturity, the sprouting capacity of the positive lines recovered gradually, and no significant differences were found between them (P > 0.05) . Thus, it can be concluded that the wheat pre-sprouting was controlled effectively in some 00T89 transgenic lines as a result of the expression of anti-trxs gene.
Genes, Plant ; Germination ; genetics ; Plant Proteins ; genetics ; metabolism ; Plants, Genetically Modified ; genetics ; growth & development ; metabolism ; RNA, Messenger ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Seeds ; genetics ; growth & development ; Thioredoxins ; genetics ; metabolism ; Transformation, Genetic ; Triticum ; genetics ; growth & development ; metabolism ; alpha-Amylases ; metabolism

The G13 domain derived from granulysin shows high antimicrobial activities against Gram-positive and Gram-negative bacteria but does not lyse Jurkat cells or liposomes. To explore a new approach for high expression of the G13 domain, we fused the sequence encoding G13 to thioredoxin (Trx) gene to construct the recombinant expression vector (pThioHisA-G13). A cyanogen bromide (CNBr) cleavage site was introduced between the Trx and G13 to facilitate final release of the recombinant G13. The recombinant expression vector, pThioHisA-G13, was transformed into E. coli BL21 (DE3). Upon induction by IPTG Trx-G13 fusion protein was expressed and took the form of inclusion bodies counting 58% (W/W) of total cellular proteins. The inclusion body was solved by urea (8 mol/L) and then cleaved by CNBr. We purified the recombinant peptide G13 by one-step cation exchange chromatography. Results of agarose diffuse assay analysis indicated that the recombinant G13 exhibited antibacterial activity. The procedure described in this study will provide a reliable and simple method for highly efficient production of some cationic antimicrobial peptides.
Anti-Infective Agents ; metabolism ; Antigens, Differentiation, T-Lymphocyte ; genetics ; Cyanogen Bromide ; pharmacology ; Escherichia coli ; genetics ; metabolism ; GTP-Binding Protein alpha Subunits, G12-G13 ; biosynthesis ; genetics ; Inclusion Bodies ; metabolism ; Protein Structure, Tertiary ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Thioredoxins ; genetics ; Transfection

Five structural important residues of rice nonspecific lipid transfer protein LTP110 were mutated by site-directed mutagenesis. Sequence results showed that they were all mutated successfully. After trying various E. coli expression systems, thioredoxin fusion expression system was found to be a proper system to express wild type and mutant LTP110. cDNA sequences encoding wild type LTP110 and the mutants Y17A, P72L, R46A, D43A, C50A were cloned into two kinds of thioredoxin fusion expression vectors. The expression results were compared. In pTrxFus/GI724 expression system, wild type LTP110 and the mutants Y17A, P72L, R46A could be expressed at low level while D43A and C50A could not be expressed normally; in pET32a(+)/BL21 (DE3) trxB- expression system, wild type LTP110 and all mutant proteins could be expressed very well and the levels were higher than that in pTrxFus/GI724 system. LTP110 fusion protein expressed in pET32a(+) vector was purified and its activity was checked by fluorescence labeled fatty acid. Results indicated that the recombinant LTP110 fusion protein has lipid binding activity. This work provides good basis for the further study.
Amino Acid Sequence ; Carrier Proteins ; genetics ; isolation & purification ; metabolism ; Gene Expression ; Genetic Engineering ; Genetic Vectors ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; Oryza ; genetics ; Plant Proteins ; genetics ; isolation & purification ; metabolism ; Recombinant Fusion Proteins ; genetics ; isolation & purification ; metabolism ; Thioredoxins ; genetics

Antimicrobial peptides (AMPs) are of great significance in the field of food, feed and medicine due to their wide spectrum of antimicrobial activity and new mechanism of action different from conventional antibiotics. AMPs production from natural sources is usually limited, and chemical synthesis is not economically practical, especially for the production of long peptides. Therefore, heterologous expression of AMPs has been widely studied as an alternative, and fusion expression plays an important role in increasing production. The present review mainly focuses on the types and bioactivities of AMPs. In addition, the recent strategies to the most commonly used carrier proteins for fusion expression of AMPs and prospects for future research were also discussed.
Anti-Infective Agents ; metabolism ; Antimicrobial Cationic Peptides ; biosynthesis ; genetics ; Escherichia coli ; genetics ; metabolism ; Glutathione Transferase ; biosynthesis ; genetics ; Green Fluorescent Proteins ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Thioredoxins ; biosynthesis ; genetics

BACKGROUNDMostly because of the limited number and proliferative ability of the transplanted hepatocytes, hepatocyte transplantation offers only temporary support to the hepatic function with rather poor functional replacement of the damaged liver parenchyma. This study aimed to observe the therapeutic effect of human thioredoxin (hTrx) gene-modified hepatocytes on experimental acute liver failure in rats.

METHODShTrx cDNA was obtained by reverse transcription-polymerase chain reaction (RT-PCR) from human osteosarcoma 143 (TK-) cells to construct the recombinant retrovirus vector pLEGFP/hTrx, which was packaged into PA317 cells to collect the recombinant retrovirus containing hTrx gene. After titration and characterization, the recombinant retrovirus was applied to primary cultured rat hepatocyte for infection to generate hTrx gene-modified rat hepatocytes, whose viability and antioxidative capacity were examined by immunohistochemistry and MTT assay, respectively. In a Sprague-Dawley (SD) rat model of acute liver failure, the modified hepatocytes were injected into the spleen, and the hepatic function and survival rate of the recipient rats were evaluated at different time points after the transplantation.

RESULTSNIH3T3 cells infected by the recombinant retrovirus were capable of expressing bioactive hTrx in the form of fusion proteins. Immunohistochemistry demonstrated normal function of the hTrx gene-modified hepatocytes, which possessed strong antioxidative capacity as shown by MTT assay. Transplantation of the modified hepatocytes in rats with acute liver failure resulted in significantly lowered serum alanine aminotransferase (ALT) and total bilirubin (TBIL) levels (P < 0.05). The hepatocytes exhibited long-term survival and efficient proliferation after transplantation. Fourteen days after the operation, the rat models receiving hTrx gene-modified hepatocytes had significantly higher survival rate than those without the transplantation.

CONCLUSIONhTrx gene-modified hepatocyte transplantation can effectively alleviate acute liver failure in rats.

Animals ; Hepatocytes ; metabolism ; transplantation ; Humans ; Liver Failure, Acute ; therapy ; Mice ; NIH 3T3 Cells ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Thioredoxins ; genetics