Reactive oxygen species (ROS) are major contributors to radiation therapy-induced side effects in cancer patients. A fusion antioxidant enzyme comprising glutathione S-transferase (GST), superoxide dismutase 1 (SOD1), and a transmembrane peptide has been shown to effectively mitigate ROS-induced damage. To enhance its targeting capability, the fusion protein was further modified by incorporating a matrix metalloproteinase-2/9 substrate peptide (X) and the transmembrane peptide R9, yielding the antioxidant enzyme GST-SOD1-X-R9 (GS1XR). This modification reduced its transmembrane ability in tumor cells, thereby selectively protecting normal cells from oxidative stress. However, the use of non-human GST poses potential immunogenicity risks. In this study, we employed seamless cloning technology to construct an expression vector containing the human GST gene to replace the non-human GST gene, and then expressed and purified novel fusion antioxidant enzymes GS1R and GS1XR. The protective effects of newly constructed GS1R and GS1XR against hydrogen peroxide (H₂O₂)-induced oxidative damage in L-02 cells were then evaluated using GS1 as a control. Enzymatic activity assays revealed that the specific activity of GST in GS1XR remained unchanged compared to the unmodified protein, while SOD activity was enhanced. Exposure to 200 μmol/L H₂O₂ transiently activated the nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway; however, this activation diminished after 24 h, reducing cell viability to 48.4%. Both GS1R and GS1XR effectively scavenged intracellular ROS, directly counteracting oxidative stress and promoting Nrf2 nuclear translocation, thereby activating antioxidant pathways and restoring cell viability to normal levels. The two enzymes showed comparable efficacy. In contrast, GS1, lacking transmembrane capability, was restricted to scavenging extracellular ROS and provided only limited protection. In conclusion, both novel fusion antioxidant enzymes demonstrated significant potential in safeguarding normal cells from ROS-mediated oxidative damage. The findings provide a foundation for further investigation in related field.
Humans ; Oxidative Stress/drug effects* ; Hydrogen Peroxide ; Antioxidants/metabolism* ; Glutathione Transferase/metabolism* ; Recombinant Fusion Proteins/pharmacology* ; Superoxide Dismutase-1 ; Reactive Oxygen Species/metabolism* ; Superoxide Dismutase/biosynthesis*

OBJECTIVES: Liver disease is the most common extra-intestinal manifestation of ulcerative colitis (UC), but the underlying pathogenesis is still not clarified. It is well accepted that the occurrence of UC-related liver disease has close correlation with immune activation, intestinal bacterial liver translocation, inflammatory cytokine storm, and the disturbance of bile acid circulation. The occurrence of UC-related liver disease makes the therapy difficult, therefor study on the pathogenesis of UC-related liver injury is of great significance for its prevention and treatment. Glutathione (GSH) shows multiple physiological activities, such as free radical scavenging, detoxification metabolism and immune defense. The synthesis and the oxidation-reduction all contribute to GSH antioxidant function. It is reported that the deficiency in hepatic GSH antioxidant function participates in multiple liver diseases, but whether it participates in the pathogenesis of UC-related liver injury is still not clear. This study aims to investigate the feature and underlying mechanism of GSH synthesis and oxidation-reduction function during the development of UC, which will provide useful information for the pathogenesis study on UC-related liver injury. METHODS: UC model was induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS)-ethanol solution (5 mg/0.8 mL per rat, 50% ethanol) via intra-colonic administration in rats, and the samples of serum, liver, and colon tissue of rats were collected at the 3rd, 5th, and 7th days post TNBS. The severity degree of colitis was evaluated by measuring the disease activity index, colonic myeloperoxidase activity, and histopathological score, and the degree of liver injury was evaluated by histopathological score and the serum content of alanine aminotransferase. Spearman correlation analysis was also conducted between the degree of colonic lesions and index of hepatic histopathological score as well as serum aspartate aminotransferase level to clarify the correlation between liver injury and colitis. To evaluate the hepatic antioxidant function of GSH in UC rats, hepatic GSH content, enzyme activity of GSH peroxidase (GSH-Px), and GSH reductase (GR) were determined in rats at the 3rd, 5th, and 7th days post TNBS, and the protein expressions of glutamine cysteine ligase (GCL), GSH synthase, GSH-Px, and GR in the liver of UC rats were also examined by Western blotting. RESULTS: Compared with the control, the disease activity index, colonic myeloperoxidase activity, and histopathological score were all significantly increased at the 3rd, 5th, and 7th days post TNBS (all P<0.01), the serum aspartate aminotransferase level and hepatic histopathologic score were also obviously elevated at the 7th day post TNBS (all P<0.05). There was a significant positive correlation between the degree of liver injury and the severity of colonic lesions (P=0.000 1). Moreover, compared with the control, hepatic GSH content and the activity of GSH-Px and GR were all significantly decreased at the 3rd and 5th days post TNBS (P<0.05 or P<0.01), and the protein expressions of GCL, GSH-Px, and GR were all obviously down-regulated at the 3rd, 5th, and 7th days post TNBS (P<0.05 or P<0.01). CONCLUSIONS There is a significant positive correlation between the degree of liver injury and the severity of colonic lesions, and the occurrence of reduced hepatic GSH synthesis and decreased GSH reduction function is obviously earlier than that of the liver injury in UC rats. The reduced hepatic expression of enzymes that responsible for GSH synthesis and reduction may contribute to the deficiency of GSH synthesis and oxidation-reduction function, indicating that the deficiency in GSH antioxidant function may participate in the pathogenesis of UC related liver injury.
Animals ; Antioxidants ; Aspartate Aminotransferases ; Colitis/chemically induced* ; Colitis, Ulcerative/metabolism* ; Colon/pathology* ; Glutathione/biosynthesis* ; Liver/metabolism* ; Peroxidase/metabolism* ; Rats ; Trinitrobenzenesulfonic Acid

Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of gamma-glutamylcysteine synthetase (gamma-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH.
Animals ; Antioxidants/*metabolism/*pharmacology ; Apoptosis/drug effects ; Caspase 3/metabolism ; Caspase 8/metabolism ; Cell Line ; Cisplatin/*toxicity ; Cysteine/*analogs & derivatives/pharmacology ; Gene Expression Regulation/*drug effects ; Gene Knockdown Techniques ; Glutathione/*metabolism ; Heme Oxygenase-1/genetics ; Intracellular Space/metabolism ; Male ; Metabolic Detoxication, Phase II/genetics ; Mice ; NF-E2-Related Factor 2/genetics ; Nitric Oxide/biosynthesis ; Organ of Corti/*drug effects/*metabolism ; RNA Interference ; Rats ; Reactive Oxygen Species/metabolism ; Superoxide Dismutase/genetics

Non-steroidal anti-inflammatory drugs (NSAIDs) induce tissue damage and oxidative stress in animal models of stomach damage. In the present study, the protective effects of wheat peptides were evaluated in a NSAID-induced stomach damage model in rats. Different doses of wheat peptides or distilled water were administered daily by gavage for 30 days before the rat stomach damage model was established by administration of NSAIDs (aspirin and indomethacin) into the digestive tract twice. The treatment of wheat peptides decreased the NSAID-induced gastric epithelial cell degeneration and oxidative stress and NO levels in the rats. Wheat peptides significantly increased the superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and decreased iNOS activity in stomach. The mRNA expression level of μ-opioid receptor was significantly decreased in wheat peptides-treated rats than that in in the control rats. The results suggest that NSAID drugs induced stomach damage in rats, wchih can be prevented by wheat peptides. The mechanisms for the protective effects were most likely through reducing NSAID-induced oxidative stress.
Animals ; Anti-Inflammatory Agents, Non-Steroidal ; adverse effects ; Antioxidants ; pharmacology ; Aspirin ; adverse effects ; Gastric Mucosa ; drug effects ; Gene Expression ; Glutathione Peroxidase ; drug effects ; Indomethacin ; adverse effects ; Male ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase ; chemical synthesis ; Oxidation-Reduction ; Oxidative Stress ; drug effects ; Plant Proteins ; pharmacology ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Receptors, Opioid, mu ; drug effects ; Stomach ; drug effects ; Superoxide Dismutase ; drug effects ; Triticum ; chemistry

OBJECTIVETo construct the vectors of human glutathione S-transferase A1 (GSTA1), P1 (GSTP1), T1(GSTT1) genes and express in Escherichia coli (E. coli).

METHODSHuman GSTA1, GSTP1 and GSTT1 gene whole length cDNAs were amplified by RT-PCR and then subcloned into pET-28a(+) vectors. The proteins were expressed in E. coli BL21(DE3). After purified by Ni2+ affinity chromatography, the enzymatic activities of GSTs were measured with 1-chloro-2,4 -dinitrobenzene (CDNB) as substrate.

RESULTSThe correct GSTA1, GSTP1 and GSTT1 genes were cloned. And soluble GSTA1, GSTT1, GSTP1 proteins were expressed in E.coli. After purification, GSTA1, GSTT1 and GSTP1 showed good enzymatic activities, which were 17.55, 0.02, 18.75 μmol·min-1·mg-1, respectively.

CONCLUSIONThe expression plasmids for GSTA1, GSTT1 and GSTP1 have been constructed and the recombinant proteins are expressed successfully.

DNA, Complementary ; genetics ; Escherichia coli ; genetics ; Genetic Vectors ; Glutathione S-Transferase pi ; biosynthesis ; genetics ; Glutathione Transferase ; biosynthesis ; genetics ; Humans ; Recombinant Proteins ; biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo examine if the ultra-highly diluted homeopathic remedy Thuja 30C can ameliorate benzo(a)pyrene (BaP)-induced DNA damage, stress and viability of perfused lung cells of Swiss albino mice in vitro.

METHODSPerfused normal lung cells from mice were cultured in 5% Roswell Park Memorial Institute medium and exposed to BaP, a potent carcinogen, at the half maximal inhibitory concentration dose (2.2 μmol/L) for 24 h. Thereafter, the intoxicated cells were either treated with Thuja 30C (used against tumor or cancer) or its vehicle media, succussed alcohol 30C. Relevant parameters of study involving reactive oxygen species (ROS) accumulation, total glutathione (GSH) content, and generations of heat shock protein (hsp)-90 were measured; the cell viability and other test parameters were measured after treatment with either Thuja 30C or its vehicle media. Circular dichroism spectroscopy was performed to examine if Thuja 30C directly interacted with calf thymus DNA as target. For ascertaining if DNA damaged by BaP could be partially repaired and restituted by the remedy, 4',6-diamidino-2-phenylindole staining was performed.

RESULTSThuja 30C increased cell viability of BaP-intoxicated cells significantly, as compared to drug-untreated or drug-vehicle control. A minimal dose of Thuja 30C significantly inhibited BaP-induced stress level, by down-regulating ROS and hsp-90, and increasing GSH content. Thuja 30C itself had no DNA-damaging effect, and no direct drug-DNA interaction. However, it showed quite striking ability to repair DNA damage caused by BaP.

CONCLUSIONThuja 30C ameliorates BaP-induced toxicity, stress and DNA damage in perfused lung cells of mice and it apparently has no effect on normal lung cells.

Animals ; Benzo(a)pyrene ; toxicity ; Cell Survival ; drug effects ; DNA Damage ; drug effects ; Glutathione ; metabolism ; HSP90 Heat-Shock Proteins ; biosynthesis ; Homeopathy ; Mice ; Mice, Inbred Strains ; Reactive Oxygen Species ; metabolism ; Thuja

This study was aimed to investigate the expression of GST-CML28 in Escherichia Coli and to prepare its antibody. The constructed recombinant expression vectors CML28-pGEX-3X were transformed into Escherichia Coli BL21 under IPTG induction. The protein was abstracted from the transformers, and purified by a GSTrap FF column. The rabbits were immunized by the purified fusion protein to produce serum with anti-CML28 antibody. The serum was purified by chromatographic column stuffed with glutathione Sephamse 4B to get the antibody. The specific antibody against CML28 was further identified by ELISA, Western blot, immunohistochemistry and quantum dot luminescence. The results indicated that GST-CML28 fusion protein was expressed in Escherichia coli and its specific polyclonal antibody was obtained. It is concluded that the anti-CML28 polyclonal antibodies with high titer and specificity are successfully prepared. These antibodies provide an useful experimental tool to profoundly research the physiological significance and biological function of the CML28 gene.
Animals ; Antibodies ; immunology ; isolation & purification ; metabolism ; Antigens, Neoplasm ; biosynthesis ; immunology ; isolation & purification ; Cells, Cultured ; Escherichia coli ; metabolism ; Exosome Multienzyme Ribonuclease Complex ; biosynthesis ; immunology ; isolation & purification ; Genetic Vectors ; Glutathione Transferase ; biosynthesis ; isolation & purification ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; RNA-Binding Proteins ; biosynthesis ; immunology ; isolation & purification ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis ; immunology ; isolation & purification

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

Prokaryotic expression vector of mouse HPV16E6 gene was constructed. A pair of primers were designed according to the digestion sites in plasmid pGEX-KG and the HPV16E6 gene sequence published by GenBank. The DNA fragment of 321bp was amplified by PCR from the HPV recombinant plasmid with HPV16E6 gene, then cloned into pGEX-KG and transformed into the host E. coli strain JM109. The fragment was conformed to the original sequence, which indicated that fusion expression vector pGEX-KG-HPV16E6 was constructed. The pGEX-KG-HPV16E6 plasmid was taken and transformed into BL21(DE3) for expression. Induced by IPTG at 37 degrees C, the expression product of HPV16E6 gene was identified by SDS-PAGE and Western blot. HPV16E6 fusion protein had been expressed successfully in the form of inclusion bodies, the molecular weight of fusion protein being 38 kD. Meanwhile, the optimum condition of HPV16E6 fusion protein expression was induced with 1.0 mmol/L IPTG for 4h. The fusion protein reacted specifically with the antibodies against HPV16E6. HPV16E6 gene was successfully expressed in E. coli, which could be used as a basis for preparing HPV16E6 vaccine in human.
Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Glutathione Transferase ; biosynthesis ; genetics ; Humans ; Oncogene Proteins, Viral ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Repressor Proteins ; biosynthesis ; genetics ; Viral Vaccines ; immunology

Bcel-2 family proteins (Bcl-x(L), Bcl-2, Mel-1 etc.) are key regulators of some life processes, including apoptosis and autophagy. They are currently considered as promising targets for developing new anti-tumor therapies. In our study, the human Bcl-2/Bcl-x(L) chimeric gene and the human/mouse Mel-1 chimeric gene were designed and cloned, and the prokaryotic expression vectors for expressing glutathione S-transferase (GST) fusion proteins and histidine tag fusion proteins were constructed respectively. These two proteins as well as the GST-Bcl-x(L) fusion protein were all successfully expressed in E. coli and subsequently purified. In addition, we measured the binding of these Bcl-2 family proteins to the Bid BH3 peptide by fluorescence polarization-based assay. The dissociation constants (Kd) obtained by us were in general agreement with the data reported in literature. The Kd values of all three proteins with or without the GST tag were almost identical. All these results validate the biological functions of these Bcl-2 family proteins obtained by us. These proteins can be used in the experimental screening of small-molecule regulators of Bcl-2 family proteins in vitro.
Escherichia coli ; genetics ; metabolism ; Fluorescence Polarization ; methods ; Glutathione Transferase ; biosynthesis ; genetics ; Humans ; Myeloid Cell Leukemia Sequence 1 Protein ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; isolation & purification ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification ; bcl-X Protein ; biosynthesis ; genetics ; isolation & purification