1.Endoplasmic reticulum molecular chaperone involved in the impairment of inner ear consistent with the mimetic aging rats.
Jing XIE ; Linhui LUO ; Qiuhong XUE ; Xin LI ; Shusheng GONG
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2010;24(1):28-32
OBJECTIVE:
To explore the involvement of endoplasmic reticulum molecular chaperone GRP78 in the impairment of inner ear consistent with the mimetic aging model.
METHOD:
Twenty-four Wistar rats were randomly divided into two groups. Model group was induced by daily hypodermic injection of 10% D-galactose (800 mg x kg(-1) x d(-1)) for 8 weeks and the control group was given saline accordingly. Spatial learning and memory was measured by Morris-Water-Maze. Colorimetry was used to analyze superoxide dismutase (SOD) and malondialdehyde (MDA) extracted from inner ear tissue. Hearing threshold of rats were detected with Auditory brainstem response (ABR). In addition, expression of GRP78 in the inner ear was detected by immunohistochemistry, RT-PCR and Western blot. The control group was studied parallel.
RESULT:
The escape latency in the model group injected with D-galactose was markedly longer than that in the control group. Accordingly, the changes of SOD and MDA were more significant in the model group, the difference between two groups was significant (t-test, P<0.01). the variation of ABR in two groups was observed, There was no statistically difference of the hearing in the model group compared with the control group (P>0.05). The expression of GRP78 was significantly different between two groups, which is increased in the inner ear tissue of model group (P<0.01).
CONCLUSION
The impairment of inner ear tissue partly dued to the oxidative stress in the model, which was induced by D-galactose and endoplasmic reticulum molecular chaperone was thought to contribute to the impairment mechanism of inner ear in mimetic aging model.
Aging
;
Animals
;
Female
;
Galactose
;
metabolism
;
Heat-Shock Proteins
;
metabolism
;
Rats
;
Rats, Wistar
2.Rational design of L-arabinose isomerase from Lactobacillus fermentum and its application in D-tagatose production.
Juan LI ; Jing WU ; Sheng CHEN ; Wei XIA
Chinese Journal of Biotechnology 2023;39(3):1107-1118
L-arabinose isomerase (L-AI) is the key enzyme that isomerizes D-galactose to D-tagatose. In this study, to improve the activity of L-arabinose isomerase on D-galactose and its conversion rate in biotransformation, an L-arabinose isomerase from Lactobacillus fermentum CGMCC2921 was recombinantly expressed and applied in biotransformation. Moreover, its substrate binding pocket was rationally designed to improve the affinity and catalytic activity on D-galactose. We show that the conversion of D-galactose by variant F279I was increased 1.4 times that of the wild-type enzyme. The Km and kcat values of the double mutant M185A/F279I obtained by superimposed mutation were 530.8 mmol/L and 19.9 s-1, respectively, and the catalytic efficiency was increased 8.2 times that of the wild type. When 400 g/L lactose was used as the substrate, the conversion rate of M185A/F279I reached a high level of 22.8%, which shows great application potential for the enzymatic production of tagatose from lactose.
Galactose/metabolism*
;
Limosilactobacillus fermentum/genetics*
;
Lactose
;
Hexoses/metabolism*
;
Aldose-Ketose Isomerases/genetics*
;
Hydrogen-Ion Concentration
3.Galactosemia.
Hanyang Medical Reviews 2005;25(3):37-41
Galactosemia, a term that denotes the presence of galactose in the blood, is the name of rare inborn error of galactose metabolism due to a deficiency of the enzyme galactokinase (GALK), galactose-1-phosphate uridyltransferase (GALT) and uridine diphosphate-galactose 4-epimerase (GALE). GALT deficiency is the most common and shows the most severe clinical manifestation, including hepatomegaly, cataracts, and mental retardation. The main symptom of GALT deficiency is juvenile cataracts. GALE deficiency has two different forms; benign and severe forms. The benign form has no clinical significance, however, the severe form shows the same clinical manifestations as those of GALT deficiency.
Cataract
;
Galactokinase
;
Galactose
;
Galactosemias*
;
Hepatomegaly
;
Intellectual Disability
;
Metabolism
;
Uridine
;
UTP-Hexose-1-Phosphate Uridylyltransferase
4.Stability of glycosylated platelets under cold storage.
Yong GUO ; Ying HAN ; Wen-Bo HU ; Guo-Bo QUAN ; Min-Xia LIU ; An LIU
Journal of Experimental Hematology 2008;16(3):681-686
This study was aimed to investigate the stability and in vitro function of glycosylated platelets concentrates after long-term refrigeration. The experiments were divided into 4 groups: group preserved at room temperature (RT group), group preserved at 4 degrees C (4T group), group glycosylated and preserved at 4 degrees C (U + 4 group) and group preserved at 4 degrees C and glycosylated (4 + U group). All groups followed for up to 14 days. The binding rate of RCA I lectin and expression of Plt surface markers CD62P, CD42b and Annexin V binding were determined by flow cytometry. pH and mean volume were determined by pH meter and hematotocytometer respectively. Platelet aggregation was detected by aggregometer. The results showed that during storage up to 14 days RCAI binding rate of modified groups was 5 - 6 fold of RT group. The pH of platelets suspension had no significant difference between these two groups (p > 0.05). Mean volumes of both groups (10.6 +/- 1.9 fL and 11.14 +/- 1.1 fL) were also no significant difference (p > 0.05). Furthermore, aggregation responsiveness of modified groups was better than that of RT groups (p < 0.05) although both decreased during the storage. The expression level of CD62P, CD42b and Annexin V binding during 5 days of storage had no significant difference between modified and fresh platelet groups (p > 0.05). While the expression level of CD62P and PS increased and the expression level of CD42b decreased during storage up to 14 days, there was significant difference between modified and fresh platelet groups (p < 0.01). It is concluded that the glycan modification is stable during storage up to 14 days. The glycosylated platelets retain in vitro function better than RT platelets during storage, but it shows activation to varying degrees in vitro after storage for 5 days.
Blood Platelets
;
cytology
;
metabolism
;
Blood Preservation
;
Cryopreservation
;
methods
;
Galactose
;
pharmacology
;
Glycosylation
;
Humans
;
Platelet Aggregation
;
drug effects
6.Effect of sijunzi decoction on malondialdehyde content and telomerase activity in heart, liver and brain tissues of D-galactose induced aging model mice.
Jing YANG ; Xiang-hong ZHAN ; Ye SUN
Chinese Journal of Integrated Traditional and Western Medicine 2005;25(6):531-533
OBJECTIVETo investigate the effect of Sijunzi decoction (SJZD) on malondialdehyde (MDA) content and telomerase activity in heart, liver and brain tissues of D-galactose (D-gal) induced aging model mice.
METHODSD-gal aging mice model was established by cervicodorsal region subcutaneous injection with 10% D-gal once a day for six successive months. The model mice in the low-, middle- and high-dose SJZD treated groups were treated with SJZD in a dose of 6 g/kg, 12 g/kg, 24 g/kg per day respectively in the volume of 0.2 ml/10 g for 6 successive weeks. While the mice in the normal control group (NCG, non-modeled) and the model control group (MCG, modeled but untreated) were treated with distilled water instead. The MDA content and telomerase activity in heart, liver and brain tissues of mice was measured with TBA colorimetric method and PCR-ELISA respectively.
RESULTSIn MCG, the MDA content in heart, liver and brain tissues was significantly higher (P < 0.01), and the telomerase activity in liver and heart tissues was significantly lower (P < 0.01) but that in brain tissue was insignificant different to that in NCG (P > 0.05) respectively. As compared with MCG, the MDA content was significantly lower in the three SJZD treated group (P < 0.01). In comparison of telomerase activity between MCG and SJZD treated groups, it was shown that in heart tissue, there was an increased trend of the activity in the low-dose and middle-dose group, but with statistical insignificance (P > 0.05), but it did show a significant increase in the high-dose group (P < 0.05); in liver tissue no significant difference was shown between the three SJZD treated groups and MCG (P > 0.05); as for that in brain tissue, significant increase only shown in the high-dose group (P < 0.01).
CONCLUSIONSJZD can antagonize free radical injury, decrease the MDA content of heart, liver and brain in D-gal aging mice, and increase the telomerase activity in heart and brain tissues but with no effect on that in liver tissue.
Aging ; drug effects ; metabolism ; Animals ; Brain ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Female ; Free Radical Scavengers ; pharmacology ; Galactose ; Liver ; metabolism ; Male ; Malondialdehyde ; metabolism ; Mice ; Myocardium ; metabolism ; Telomerase ; metabolism
7.NADPH oxidase-dependent oxidative stress and mitochondrial damage in hippocampus of D-galactose-induced aging rats.
Zhengde DU ; Yujuan HU ; Yang YANG ; Yu SUN ; Sulin ZHANG ; Tao ZHOU ; Lingling ZENG ; Wenjuan ZHANG ; Xiang HUANG ; Weijia KONG ; Honglian ZHANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(4):466-472
Mitochondrial DNA (mtDNA) common deletion (CD) plays a significant role in aging and age-related diseases. In this study, we used D-galactose (D-gal) to generate an animal model of aging and the involvement and causative mechanisms of mitochondrial damage in such a model were investigated. Twenty 5-week-old male Sprague-Dawley rats were randomly divided into two groups: D-gal group (n=10) and control group (n=10). The quantity of the mtDNA CD in the hippocampus was determined using a TaqMan real-time PCR assay. Transmission electron microscopy was used to observe the mitochondrial ultrastructure in the hippocampus. Western blot was used to detect the protein levels of NADPH oxidase (NOX) and uncoupling protein 2 (UCP2). We found that the level of mtDNA CD was significantly higher in the hippocampus of D-gal-induced aging rats than in control rats. In comparison with the control group, the mitochondrial ultrastructure in the hippocampus of D-gal-treated rats was damaged, and the protein levels of NOX and UCP2 were significantly increased in the hippocampus of D-gal-induced aging rats. This study demonstrated that the levels of mtDNA CD and NOX protein expression were significantly increased in the hippocampus of D-gal-induced aging rats. These findings indicate that NOX-dependent reactive oxygen species generation may contribute to D-gal-induced mitochondrial damage.
Aging
;
metabolism
;
physiology
;
Animals
;
Galactose
;
adverse effects
;
metabolism
;
Hippocampus
;
metabolism
;
physiology
;
Male
;
Mitochondria
;
metabolism
;
physiology
;
NADPH Oxidases
;
metabolism
;
Oxidative Stress
;
physiology
;
Rats
;
Rats, Sprague-Dawley
8.Biochemical characters and antibiotic susceptibility of Staphylococcus aureus isolates.
Subhankari Prasad CHAKRABORTY ; Santanu Kar MAHAPATRA ; Somenath ROY
Asian Pacific Journal of Tropical Biomedicine 2011;1(3):212-216
OBJECTIVETo observe the biochemical characters and antibiotic susceptibility of isolated Staphylococcus aureus (S. auerus) strains against some conventional and traditional antibiotics.
METHODSThirty post operative pathogenic isolated S. aureus strains were used in this study. Bacterial culture was done in Mueller-Hinton broth at 37 °C. Characters of these strains were determined by traditional biochemical tests such as hydrolysis test of gelatin, urea, galactose, starch and protein, and fermentation of lactose and sucrose. Antibiotic susceptibility were carried out by minimum inhibitory concentration test, minium bactericidal concentration test, disc agar diffusion test and brain heart infusion oxacillin screening agar.
RESULTSFrom this study, it was observed that 100% S. aureus isolates showed positive results in gelatin, urea and galactose hydrolysis test, 50% isolates were positive in starch hydrolysis test, 35% in protein hydrolysis test, 100% isolates in lactose fermenting test, but no isolate was positive in sucrose fermenting test. Antibiotic susceptibility testing suggested that 20% of isolates were resistant to kanamycin and 46.67% were resistant to oxacillin.
CONCLUSIONSThese findings show that all these isolates have gelatin, urea, galactose hydrolysis and lactose fermenting activity. 20% of these isolates were resistant to kanamycin and 46.67% were resistant to oxacillin.
Anti-Bacterial Agents ; pharmacology ; Disk Diffusion Antimicrobial Tests ; Galactose ; metabolism ; Gelatin ; metabolism ; Hydrolysis ; Microbial Sensitivity Tests ; Staphylococcus aureus ; drug effects ; isolation & purification ; metabolism ; Starch ; metabolism ; Urea ; metabolism
9.Expression of the glycoprotein in atrioventricular cell membrane of acute myocardial infarction in human.
Zhao-hui LI ; Hua-lan JING ; Xiao-shan LIU
Journal of Forensic Medicine 2003;19(3):136-137
OBJECTIVE:
To study the expression of the glycoprotein in atrioventricular cell membrane of the acute myocardial infarction.
METHODS:
The glycoprotein changes occurred at the atrioventricular cell membrane of the acute myocardial infarction of 8 cases were observed by using immunohistochemical methods.
RESULTS:
Positive staining of PNA could be observed in atrioventricular cell membrane.
CONCLUSION
This experiment proved that atrioventricular cell membrane expressed D-galactose as same as myocardial cell membrane in the acute myocardial infarction.
Atrioventricular Node/metabolism*
;
Cell Membrane/metabolism*
;
Forensic Medicine
;
Galactose/genetics*
;
Humans
;
Male
;
Membrane Glycoproteins/genetics*
;
Middle Aged
;
Myocardial Infarction/metabolism*
;
Myocardium/metabolism*
10.Screening of food-grade microorganisms for biotransformation of D-tagatose and cloning and expression of L-arabinose isomerase.
Yan MEN ; Yueming ZHU ; Yuping GUAN ; Tongcun ZHANG ; Ken IZUMORI ; Yuanxia SUN
Chinese Journal of Biotechnology 2012;28(5):592-601
L-Arabinose isomerase (L-AI) is an intracellular enzyme that catalyzes the reversible isomerization of D-galactose and D-tagatose. Given the widespread use of D-tagatose in the food industry, food-grade microorganisms and the derivation of L-AI for the production of D-tagatose is gaining increased attention. In the current study, food-grade strains from different foods that can convert D-galactose to D-tagatose were screened. According to physiological, biochemical, and 16S rDNA gene analyses, the selected strain was found to share 99% identity with Pediococcus pentosaceus, and was named as Pediococcus pentosaceus PC-5. The araA gene encoding L-AI from Pediococcus pentosaceus PC-5 was cloned and overexpressed in E. coli BL21. The yield of D-tagatose using D-galactose as the substrate catalyzed by the crude enzyme in the presence of Mn2+ was found to be 33% at 40 degrees C.
Aldose-Ketose Isomerases
;
biosynthesis
;
genetics
;
Biotransformation
;
Cloning, Molecular
;
Escherichia coli
;
genetics
;
metabolism
;
Galactose
;
metabolism
;
Genetic Vectors
;
genetics
;
Hexoses
;
metabolism
;
Pediococcus
;
classification
;
genetics
;
isolation & purification
;
Recombinant Proteins
;
biosynthesis
;
genetics