1.Highly efficient production of L-valine by multiplex metabolic engineering of Corynebacterium glutamicum.
Kuo ZHAO ; Jinyu CHENG ; Liang GUO ; Cong GAO ; Wei SONG ; Jing WU ; Jia LIU ; Yadi LIU ; Liming LIU ; Xiulai CHEN
Chinese Journal of Biotechnology 2023;39(8):3253-3272
As a branched chain amino acid, L-valine is widely used in the medicine and feed sectors. In this study, a microbial cell factory for efficient production of L-valine was constructed by combining various metabolic engineering strategies. First, precursor supply for L-valine biosynthesis was enhanced by strengthening the glycolysis pathway and weakening the metabolic pathway of by-products. Subsequently, the key enzyme in the L-valine synthesis pathway, acetylhydroxylate synthase, was engineered by site-directed mutation to relieve the feedback inhibition of the engineered strain. Moreover, promoter engineering was used to optimize the gene expression level of key enzymes in L-valine biosynthetic pathway. Furthermore, cofactor engineering was adopted to change the cofactor preference of acetohydroxyacid isomeroreductase and branched-chain amino acid aminotransferase from NADPH to NADH. The engineered strain C. glutamicum K020 showed a significant increase in L-valine titer, yield and productivity in 5 L fed-batch bioreactor, up to 110 g/L, 0.51 g/g and 2.29 g/(L‧h), respectively.
Valine
;
Corynebacterium glutamicum/genetics*
;
Metabolic Engineering
;
Amino Acids, Branched-Chain
;
Bioreactors
2.Analysis of the difference in metabolites and gene expressions between pre-receptive and receptive endometria.
Qin SHU ; Yan ZHAO ; Ancong WANG ; Wen LI ; Hongyan XU ; Wei DONG ; Qin MENG
Chinese Journal of Medical Genetics 2023;40(12):1496-1503
OBJECTIVE:
To analyze the difference in the gene expression, amino acid and carnitine levels in the cervical secretions between the endometria of pre-receptive and receptive stages, with an aim to provide clues for identifying new molecular markers for endometrial receptivity.
METHODS:
Fifty nine infertile women treated at the Department of Reproductive Medicine of Linyi People's Hospital from January 6, 2020 to January 31, 2022 were selected as as the study subjects, which were matched with 3 pairs (6 cases) of infertile women preparing for embryo transfer based on factors such as age, body mass index, and length of infertility. Endometrial tissue samples were collected for gene transcription and expression analysis. Twenty five women who had become pregnant through assisted reproductive technology were selected as the control group, and 28 non-pregnant women receiving ovulation monitoring at the Outpatient Department were enrolled as the case group. Status of endometrial receptivity was determined by ultrasonography. In the former group, endometrial tissues were sampled for sequencing, and GO and KEGG database enrichment analysis of differentially expressed genes was carried out. In the latter group, cervical secretions were collected, and amino acid and carnitine levels were measured by mass spectrometry. Statistical analysis was carried out using rank sum test, t test and chi-square test with SPSS v25.0 software.
RESULTS:
No difference was found in the clinical data of the patients with regard to age, body mass index, infertility years, AMH, FSH, LH, E2, and type of infertility. Compared with the receptive endometrial tissues, there were 100 significantly up-regulated genes and 191 significantly down-regulated genes in the pre-receptive endometrial tissue, with the most significantly altered ones being HLA-DRB5 and MMP10. The biological processes, molecular functions and pathways enriched by more differentially expressed genes in GO and KEGG were mainly immune regulation, cell adhesion and tryptophan metabolism. Analysis of secretion metabolism also revealed a significant difference in the levels of amino acids and carnitine metabolites between the two groups (P < 0.05), in particular those of Alanine, Valine, 3-hydroxybutyrylcarnitine (C4OH) + malonylcarnitine (C3DC)/captoylcarnitine (C10).
CONCLUSION
A significant difference has been discovered in the levels of gene transcription and protein expression in the endometrial tissues from the pre-receptive and receptive stages. The levels of amino acids and carnitine, such as Alanine, Valine, 3-hydroxybutyryl carnitine (C4OH)+malonyl carnitine (C3DC)/caproyl carnitine (C10), may be associated with the receptive status of the endometrium, though this need to be verified with larger samples.
Pregnancy
;
Humans
;
Female
;
Infertility, Female/genetics*
;
Endometrium/metabolism*
;
Amino Acids/metabolism*
;
Gene Expression
;
Carnitine
;
Alanine/metabolism*
;
Valine/metabolism*
3.High expression of VARS promotes the growth of multiple myeloma cells by causing imbalance in valine metabolism.
Rui SHI ; Wanqing DU ; Yanjuan HE ; Jian HU ; Han YU ; Wen ZHOU ; Jiaojiao GUO ; Xiangling FENG
Journal of Central South University(Medical Sciences) 2023;48(6):795-808
OBJECTIVES:
Multiple myeloma (MM) is a plasma cell malignancy occurring in middle and old age. MM is still an incurable disease due to its frequent recurrence and drug resistance. However, its pathogenesis is still unclear. Abnormal amino acid metabolism is one of the important characteristics of MM, and the important metabolic pathway of amino acids participates in protein synthesis as basic raw materials. Aminoacyl transfer ribonucleic acid synthetase (ARS) gene is a key regulatory gene in protein synthesis. This study aims to explore the molecular mechanism for ARS, a key factor of amino acid metabolism, in regulating amino acid metabolism in MM and affecting MM growth.
METHODS:
The corresponding gene number was combined with the gene expression profile GSE5900 dataset and GSE2658 dataset in Gene Expression Omnibus (GEO) database to standardize the gene expression data of ARS. GSEA_4.2.0 software was used to analyze the difference of gene enrichment between healthy donors (HD) and MM patients in GEO database. GraphPad Prism 7 was used to draw heat maps and perform data analysis. Kaplan-Meier and Cox regression model were used to analyze the expression of ARS gene and the prognosis of MM patients, respectively. Bone marrow samples from 7 newly diagnosed MM patients were collected, CD138+ and CD138- cells were obtained by using CD138 antibody magnetic beads, and the expression of ARS in MM clinical samples was analyzed by real-time RT-PCR. Human B lymphocyte GM12878 cells and human MM cell lines ARP1, NCI-H929, OCI-MY5, U266, RPMI 8266, OPM-2, JJN-3, KMS11, MM1.s cells were selected as the study objects. The expression of ARS in MM cell lines was analyzed by real-time RT-PCR and Western blotting. Short hairpin RNA (shRNA) lentiviruses were used to construct gene knock-out plasmids (VARS-sh group). No-load plasmids (scramble group) and gene knock-out plasmids (VARS-sh group) were transfected into HEK 293T cells with for virus packaging, respectively. Stable expression cell lines were established by infecting ARP1 and OCI-MY5 cells, and the effects of knockout valyl-tRNA synthetase (VARS) gene on proliferation and apoptosis of MM cells were detected by cell counting and flow cytometry, respectively. GEO data were divided into a high expression group and a low expression group according to the expression of VARS. Bioinformatics analysis was performed to explore the downstream pathways affected by VARS. Gas chromatography time-of-flight mass spectrometry (GC-TOF/MS) and high performance liquid chromatography (HPLC) were used to detect the valine content in CD138+ cells and ARP1, OCI-MY5 cells and supernatant of knockdown VARS gene in bone marrow samples from patients, respectively.
RESULTS:
Gene enrichment analysis showed that tRNA processing related genes were significantly enriched in MM compared with HD (P<0.0001). Further screening of tRNA processing-pathway related subsets revealed that cytoplasmic aminoacyl tRNA synthetase family genes were significantly enriched in MM (P<0.0001). The results of gene expression heat map showed that the ARS family genes except alanyl-tRNA synthetase (AARS), arginyl-tRNA synthetase (RARS), seryl-tRNA synthetase (SARS) in GEO data were highly expressed in MM (all P<0.01). With the development of monoclonal gammopathy of undetermined significance (MGUS) to MM, the gene expression level was increased gradually. Kaplan-Meier univariate analysis of survival results showed that there were significant differences in the prognosis of MM patients in methionyl-tRNA synthetase (MARS), asparaginyl-tRNA synthetase (NARS) and VARS between the high expression group and the low expression group (all P<0.05). Cox regression model multivariate analysis showed that the high expression of VARS was associated with abnormal overall survival time of MM (HR=1.83, 95% CI 1.10 to 3.06, P=0.021). The high expression of NARS (HR=0.90, 95% CI 0.34 to 2.38) and MARS (HR=1.59, 95% CI 0.73 to 3.50) had no effect on the overall survival time of MM patients (both P>0.05). Real-time RT-PCR and Western blotting showed that VARS, MARS and NARS were highly expressed in CD138+ MM cells and MM cell lines of clinical patients (all P<0.05). Cell counting and flow cytometry results showed that the proliferation of MM cells by knockout VARS was significantly inhibited (P<0.01), the proportion of apoptosis was significantly increased (P<0.05). Bioinformatics analysis showed that in addition to several pathways including the cell cycle regulated by VARS, the valine, leucine and isoleucine catabolic pathways were upregulated. Non-targeted metabolomics data showed reduced valine content in CD138+ tumor cells in MM patients compared to HD (P<0.05). HPLC results showed that compared with the scramble group, the intracellular and medium supernatant content of ARP1 cells and the medium supernatant of OCI-MY5 in the VARS-shRNA group was increased (all P<0.05).
CONCLUSIONS
MM patients with abnormal high expression of VARS have a poor prognosis. VARS promotes the malignant growth of MM cells by affecting the regulation of valine metabolism.
Humans
;
Valine-tRNA Ligase
;
Multiple Myeloma/genetics*
;
Metabolomics
;
Amino Acids
;
RNA, Transfer
4.Nucleus-targeted Dmp1 transgene fails to rescue dental defects in Dmp1 null mice.
Shu-Xian LIN ; Qi ZHANG ; Hua ZHANG ; Kevin YAN ; Leanne WARD ; Yong-Bo LU ; Jian-Quan FENG
International Journal of Oral Science 2014;6(3):133-141
Dentin matrix protein 1 (DMP1) is essential to odontogenesis. Its mutations in human subjects lead to dental problems such as dental deformities, hypomineralization and periodontal impairment. Primarily, DMP1 is considered as an extracellular matrix protein that promotes hydroxyapatite formation and activates intracellular signaling pathway via interacting with αvβ3 integrin. Recent in vitro studies suggested that DMP1 might also act as a transcription factor. In this study, we examined whether full-length DMP1 could function as a transcription factor in the nucleus and regulate odontogenesis in vivo. We first demonstrated that a patient with the DMP1 M1V mutation, which presumably causes a loss of the secretory DMP1 but does not affect the nuclear translocation of DMP1, shows a typical rachitic tooth defect. Furthermore, we generated transgenic mice expressing (NLS)DMP1, in which the endoplasmic reticulum (ER) entry signal sequence of DMP1 was replaced by a nuclear localization signal (NLS) sequence, under the control of a 3.6 kb rat type I collagen promoter plus a 1.6 kb intron 1. We then crossbred the (NLS)DMP1 transgenic mice with Dmp1 null mice to express the (NLS)DMP1 in Dmp1-deficient genetic background. Although immunohistochemistry demonstrated that (NLS)DMP1 was localized in the nuclei of the preodontoblasts and odontoblasts, the histological, morphological and biochemical analyses showed that it failed to rescue the dental and periodontal defects as well as the delayed tooth eruption in Dmp1 null mice. These data suggest that the full-length DMP1 plays no apparent role in the nucleus during odontogenesis.
Animals
;
Cell Nucleus
;
genetics
;
Codon, Initiator
;
genetics
;
Collagen Type I
;
genetics
;
Endoplasmic Reticulum
;
genetics
;
Extracellular Matrix Proteins
;
genetics
;
Familial Hypophosphatemic Rickets
;
genetics
;
Gene Targeting
;
methods
;
Genetic Vectors
;
genetics
;
Humans
;
Introns
;
genetics
;
Methionine
;
genetics
;
Mice, Inbred C57BL
;
Mice, Transgenic
;
Mutation
;
genetics
;
Odontoblasts
;
cytology
;
Odontogenesis
;
genetics
;
Periodontal Diseases
;
genetics
;
Periodontal Ligament
;
pathology
;
Phosphoproteins
;
genetics
;
Promoter Regions, Genetic
;
genetics
;
Tooth Abnormalities
;
genetics
;
Tooth Eruption
;
genetics
;
Transcription Factors
;
genetics
;
Transgenes
;
genetics
;
Valine
;
genetics
;
Young Adult
5.Lack of association between the LRRK2 A419V variant and Asian Parkinson's disease.
Aroma Agape GOPALAI ; Shen Yang LIM ; Zariah Abdul AZIZ ; Soo Kun LIM ; Li Ping TAN ; Yip Boon CHONG ; Chong Tin TAN ; Santhi PUVANARAJAH ; Shanti VISWANATHAN ; Rishikesan KUPPUSAMY ; Ai Huey TAN ; Thien Thien LIM ; Gaik Bee EOW ; Mohamed Ibrahim NORLINAH ; Hui Hua LI ; Yi ZHAO ; Azlina AHMAD-ANNUAR
Annals of the Academy of Medicine, Singapore 2013;42(5):237-240
INTRODUCTIONThe G2385R and R1628P LRRK2 gene variants have been associated with an increased risk of Parkinson's disease (PD) in the Asian population. Recently, a new LRRK2 gene variant, A419V, was reported to be a third risk variant for PD in Asian patients. Our objective was to investigate this finding in our cohort of Asian subjects.
MATERIALS AND METHODSEight hundred and twenty-eight subjects (404 PD patients, and 424 age and gender-matched control subjects without neurological disorders) were recruited. Genotyping was done by Taqman® allelic discrimination assay on an Applied Biosystems 7500 Fast Real-Time PCR machine.
RESULTSThe heterozygous A419V genotype was found in only 1 patient with PD, compared to 3 in the control group (0.4% vs 1.3%), giving an odds ratio of 0.35 (95% confidence interval (CI), 0.01 to 3.79; P = 0.624).
CONCLUSIONA419V is not an important LRRK2 risk variant in our Asian cohort of patients with PD. Our data are further supported by a literature review which showed that 4 out of 6 published studies reported a negative association of this variant in PD.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Alanine ; genetics ; Case-Control Studies ; China ; ethnology ; Cohort Studies ; Cytosine ; Female ; Gene Frequency ; Genetic Variation ; genetics ; Genotype ; Heterozygote ; Humans ; India ; ethnology ; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 ; Malaysia ; ethnology ; Male ; Middle Aged ; Parkinson Disease ; genetics ; Polymorphism, Genetic ; genetics ; Protein-Serine-Threonine Kinases ; genetics ; Risk Factors ; Singapore ; Thymine ; Valine ; genetics ; Young Adult
6.The effect of valsartan on the expression of the receptor for advanced glycation end products in human glomerular mesangial cells.
Lin-na ZHONG ; Guo-liang HUANG ; Min FENG ; Ying ZHANG
Chinese Journal of Applied Physiology 2011;27(3):338-342
OBJECTIVETo elucidate the effect of valsartan on human glomerular mesangial cells oxidative stress and the expression of the receptor for advanced glycation end products (RAGE) induced by the advanced glycation end-products (AGEs).
METHODSHuman glomerular mesangial cells were treated with advanced glycation end-product-bovine serum albumin (AGE-BSA) in the presence of valsartan. The reactive oxygen species (ROS) in cells were measured by Flow cytometry, and the mRNA of p47 phox, which was the primary subunits of NADPH oxidase, was detected by semi-quantitative reberse transcription polymerase chain reaction (RT-PCR). The mRNA of RAGE was detected by RT-PCR and the RAGE protein was assayed by immunocytochemistry.
RESULTSThe product of ROS, and the expression of p47 phox and RAGE in mesangial cells, which were treated with AGE-BSA in the presence of valsartan, were down-regulated compared with the groups treated with AGE-BSA (P < 0.05). Valsartan dose-dependently and time-dependently inhibited the AGE-elicited overexpression of RAGE, ROS and p47(phox) in mesangial cells.
CONCLUSIONValsartan could inhibit RAGE expression through downregulation of oxidative stress.
Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Antioxidants ; pharmacology ; Glycation End Products, Advanced ; pharmacology ; Humans ; Mesangial Cells ; cytology ; metabolism ; Oxidative Stress ; drug effects ; RNA, Messenger ; genetics ; metabolism ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; genetics ; metabolism ; Serum Albumin, Bovine ; pharmacology ; Tetrazoles ; pharmacology ; Valine ; analogs & derivatives ; pharmacology ; Valsartan
7.Intermedin (IMD) gene expression in hypertrophic cardiac myocyte of renal vascular hypertension rats and the intervention of Valsartan, Amlodipine and Enalapril in the expression.
Jing DONG ; Xiaoping CHEN ; Yanling SO ; Hongbo XIN ; Wei JIANG ; Lingyun JIANG
Journal of Biomedical Engineering 2009;26(5):1082-1087
This experiment on rats was aimed to investigate the expression of intermedin (IMD) in hypertrophic cardiac myoctye of renal vascular hypertension induced by incomplete ligation of the left renal artery, and so to detect and compare the changes of the expression after administration of Valsartan, Amlodipine and Enalapril respectively. The criterion for standard modeling was systolic pressure > or = 140 mmHg. At 4 weeks after successful modeling, 60 SD male rats were randomly divided into 5 groups, namely the hypertrophy group, the 3 drug-treatment groups, and the sham-operation group as control. Blood pressure, left ventricular mass index (LVMI), and the left ventricular mean transverse diameter of myocardial cell (LVTDM) were investigated at the 10th week after model establishment. Gene expression of IMD mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR), and the optical density of the band was measured by use of the Gel Documentation System. The ratio of IMD mRNA to beta-actin mRNA was considered the relative amount of IMD. When compared with control, the blood pressure increased significantly in the hypertrophy group. There was no statistically significant difference between the treatment groups. No significant difference in heart rate was noted at 4 weeks after operation in all groups. LVMI and LVTDM levels were significantly higher in the hypertrophy group than in the other groups; LVMI and LVTDM levels showed no significant difference among the treatment groups but they were obviously higher than those of the Sham-operation group. The gene expression of IMD mRNA in the hypertrophy group was upregulated in the myocardium, when compared with that in the other groups. Meanwhile, although IMD mRNA in the treament groups was higher than that in the Sham-operation group, no statistically significant difference of myocardial IMD mRNA was found between the treament groups. These results suggested that, in this experiment, intracardiac IMD mRNA was upregulated and could participate in the regulation of cardiac remodeling in renal vascular hypertension-induced cardiac hypertrophy. This upregulation could improve the pathologic and physiologic process of cardiac hypertrophy, and could associate with the pressure loading or myocardia hypertrophy. However, the change did not display any difference that could be attributed to the variety of hypotensive drugs.
Adrenomedullin
;
genetics
;
metabolism
;
Amlodipine
;
therapeutic use
;
Animals
;
Antihypertensive Agents
;
therapeutic use
;
Cardiomegaly
;
etiology
;
metabolism
;
Enalapril
;
therapeutic use
;
Hypertension, Renovascular
;
complications
;
drug therapy
;
metabolism
;
Male
;
Myocardium
;
metabolism
;
Neuropeptides
;
genetics
;
metabolism
;
RNA, Messenger
;
genetics
;
metabolism
;
Random Allocation
;
Rats
;
Rats, Sprague-Dawley
;
Tetrazoles
;
therapeutic use
;
Valine
;
analogs & derivatives
;
therapeutic use
;
Valsartan
8.Permanent myopathy caused by mutation of SCN4A Metl592Val: Observation on myogenesis in vitro and on effect of basic fibroblast growth factor on the muscle.
Yu FENG ; Hong WANG ; Xiao-Guang LUO ; Yan REN
Neuroscience Bulletin 2009;25(2):61-66
OBJECTIVEThe present study is to observe in vitro the proliferation ability of the muscle cells from permanent myopathy (PM) patients of nomokalaemic periodic paralysis (normKPP), which is caused by mutations of Met1592Val in the skeletal muscle voltage gated sodium channel (SCN4A) gene on chromosome 17q23.1. We also evaluate the possible effect of the foreign basic fibroblast growth factor (bFGF) in preventing and curing PM.
METHODSThe gastrocnemius muscle cells were taken from two male patients with PM of the same Chinese family with Met1592Val mutation of SCN4A, determined by gene screening. Four male patients suffering from the skeletal injury without PM were taken as control. All preparations were protogenerationally cultured in vitro. Proliferation of the cultured preparations was measured by MTT. Activities of the lactic dehydrogenase (LDH), creatine kinase (CK), and protein content in these cells were also detected. The effects of bFGF with different doses (10 ng/mL, 20 ng/mL, 40 ng/mL, 80 ng/mL, 120 ng/mL and 160 ng/mL) on the above mentioned parameters were also evaluated.
RESULTSCells from both PM and control subjects were successfully cultured in vitro. The cultivation of the muscle cells from PM patients in vitro was not yet seen. Results indicated the obvious stimulation of bFGF on cell proliferation, activities of LDH and CK, protein synthesis, in a dose dependent manner. The optimal dose of bFGF was 120 ng/mL (P<0.05), beyond which greater dose caused a less effect. The effect of bFGF on 160 ng /mL was stronger than that on 80 ng/mL, but there was no significant difference (P>0.05).
CONCLUSIONMyoblastic cells from patients with PM had a weaker ability of developing into the myotubules, thus they were unable to perform effective regeneration, which resulted in a progressive necrosis. The exogenous bFGF could promote the division and proliferation of the muscle cells in vitro. These results shield a light on bFGFos potential role in preventing and treating PM.
Adult ; Cell Proliferation ; drug effects ; Cells, Cultured ; Creatine Kinase ; metabolism ; Dose-Response Relationship, Drug ; Fibroblast Growth Factor 2 ; pharmacology ; Humans ; L-Lactate Dehydrogenase ; metabolism ; Male ; Methionine ; genetics ; Middle Aged ; Muscle Development ; genetics ; physiology ; Muscular Diseases ; genetics ; pathology ; Mutation ; genetics ; Myoblasts ; drug effects ; NAV1.4 Voltage-Gated Sodium Channel ; Sodium Channels ; genetics ; Valine ; genetics
9.Age-dependent dichotomous effect of superoxide dismutase Ala16Val polymorphism on oxidized LDL levels.
George V DEDOUSSIS ; Stavroula KANONI ; Demosthenes B PANAGIOTAKOS ; Eirini LOUIZOU ; Efi GRIGORIOU ; Christina CHRYSOHOOU ; Christos PITSAVOS ; Christodoulos STEFANADIS
Experimental & Molecular Medicine 2008;40(1):27-34
We investigated the association between superoxide dismutase (SOD) Ala16Val polymorphism and the levels of oxidized LDL lipoprotein-C (ox-LDL-C) in two age-different Greek cohorts. Four hundred fifteen middle-aged (n=147 females: 43.2+/-13 years, n=268 males: 43.3+/-14 years) Caucasian Greek subjects consisted the middle aged cohort. One hundred seventy five elderly (n=88 females: 79.9+/-4 years; n=87 males: 80.6+/-4 years) were selected from the elderly cohort. Genotype data were obtained for all of them. Multiple linear regression analysis, stratified by gender and adjusted for age, smoking habits and body mass index as covariates, showed higher ox-LDL-C levels for the middle aged men with the Val/Val genotype, compared to the other allele (Ala/Ala and Ala/Val) carriers (65.9+/-25.7 vs. 55.7+/-20.5 mg/dl; standardized beta coefficient=0.192, P=0.012). On the contrary, elderly women with the Val/Val genotype occurred with lower ox-LDL-C levels compared to the Ala/Ala or Ala/Val genotype (74.2+/-22.1 vs. 86.5+/-26.6 mg/dl; standardized beta coefficient= -0.269, P=0.015). The same trend was also recorded in elderly men, however without reaching statistical significance (standardized b coefficient= -0.187, P=0.077). Moreover, elderly men and women with the Ala/Ala or Ala/Val genotype presented higher triglycerides levels compared to Val/Val (women: 145.2+/-68.7 vs. 114.3+/-34.3 mg/dl, P= 0.027; men: 147.8+/-72.4 vs. 103.7 +/-38.0 mg/dl, P=0.002). Additionally, middle aged men with the Val/Val genotype had higher HDL-C levels compared to the Ala allele carriers. The results suggest that SOD Ala16Val polymorphism is an age-dependent modulator of ox-LDL-C levels in middle-aged men and elderly women.
Adult
;
Aged
;
Aged, 80 and over
;
Aging/*genetics
;
Alanine/*genetics
;
Female
;
Genotype
;
Humans
;
Lipoproteins, LDL/*metabolism
;
Male
;
Middle Aged
;
Polymorphism, Single Nucleotide/*genetics
;
Regression Analysis
;
Sex Characteristics
;
Superoxide Dismutase/*genetics
;
Valine/*genetics
10.Effect of valsartan on the expression of angiotensin II receptors in the lung of chronic antigen exposure rats.
Tong WANG ; Kai-sheng YIN ; Kou-yin LIU ; Guo-jun LU ; Yu-hua LI ; Jun-di CHEN
Chinese Medical Journal 2008;121(22):2312-2319
BACKGROUNDMany studies have suggested that angiotensin II (Ang II) and its receptors may be involved in the development of asthma. However, the expression of angiotensin II receptors (AGTR) is not clear in the lung tissue of chronic asthmatics. This study was designed to determine the relationship between airway remodeling, dysfunction and the expression of AGTRs in a rat model of asthma.
METHODSRats were sensitized with ovalbumin (OVA) for 2 weeks. Sixty minutes before an inhalation challenge, the rats were pretreated either with valsartan (15, 30, 50 mg x kg(-1) x d(-1)) or saline intragastrically. Then the rats received an OVA challenge for 30 alternative days. Acetylcholine (Ach)-induced bronchoconstriction was measured after the final antigen challenge. White cell counts in bronchoalveolar lavage fluid (BALF) and morphological changes in the airways were then assessed. The levels of transforming growth factor-beta 1 (TGF-beta(1)) and platelet-derived growth factor (PDGF) in BALF were detected by ELISA. The levels of AGTR1 and AGTR2 mRNA and protein in lung tissues were measured by RT-PCR and Western blotting.
RESULTSAGTR1 mRNA and protein levels in repeatedly OVA-challenged rats were significantly increased as compared with negative controls. The AGTR1 mRNA expression versus white cell counts of BALF and airway wall thickness (mainly in small airways) in lungs of chronic antigen-exposed rats were positively correlated. Valsartan decreased the level of AGTR1 in repeatedly OVA-challenged rats. However, AGTR2 mRNA and protein levels in the OVA-challenged rats and high-dose valsartan-treated rats (50 mg x kg(-1) x d(-1)) were also increased. Valsartan significantly decreased inflammatory cell accumulation and attenuated Ach-evoked bronchoconstriction in repeatedly antigen-challenged rats. Valsartan also decreased allergen-induced structural changes in rat airway (including total airway wall thickness and smooth muscle area) and the levels of TGF-beta(1) and PDGF in BALF.
CONCLUSIONSAGTR1 expression is potentially associated with airway remodeling and dysfunction in asthma. Ang II and AGTR1 may participate in airway inflammation and airway remodeling of chronic antigen-exposed rats. Valsartan, a AGTR1 antagonist, could inhibit AGTR1 expression and partially inhibits structural airway changes as well as airway inflammation in chronic OVA-exposed rats.
Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Angiotensin Receptor Antagonists ; Animals ; Asthma ; chemically induced ; genetics ; metabolism ; Blotting, Western ; Bronchoalveolar Lavage Fluid ; chemistry ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; drug effects ; Lung ; drug effects ; metabolism ; pathology ; Male ; Ovalbumin ; Platelet-Derived Growth Factor ; metabolism ; Rats ; Rats, Wistar ; Receptor, Angiotensin, Type 1 ; genetics ; metabolism ; Receptor, Angiotensin, Type 2 ; genetics ; metabolism ; Receptors, Angiotensin ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Tetrazoles ; pharmacology ; Transforming Growth Factor beta1 ; metabolism ; Valine ; analogs & derivatives ; pharmacology ; Valsartan

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