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Wu ZD, Zhang Q, Yin J, Wang XM, Zhang ZJ, Wu WF, Li FJ. Author Correction: Interactions of multiple biological fields in stored grain ecosystems. Sci Rep 2024; 14:4388. [PMID: 38388658 PMCID: PMC10883938 DOI: 10.1038/s41598-024-54618-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024] Open
Affiliation(s)
- Z D Wu
- Jilin University, Changchun, China.
| | - Q Zhang
- University of Manitoba, Winnipeg, Manitoba, Canada.
| | - J Yin
- Academy of National Food and Strategic Reservation Administration, Beijing, China
| | - X M Wang
- Jilin University, Changchun, China
| | - Z J Zhang
- Academy of National Food and Strategic Reservation Administration, Beijing, China
| | - W F Wu
- Jilin University, Changchun, China
| | - F J Li
- Academy of National Food and Strategic Reservation Administration, Beijing, China
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Lin CH, Tsai CH, Chou CC, Wu WF. A Transient π-π or Cation-π Interaction between Degron and Degrader Dual Residues: A Key Step for the Substrate Recognition and Discrimination in the Processive Degradation of SulA by ClpYQ (HslUV) Protease in Escherichia coli. Int J Mol Sci 2023; 24:17353. [PMID: 38139184 PMCID: PMC10743992 DOI: 10.3390/ijms242417353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/06/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
The Escherichia coli ATP-dependent ClpYQ protease constitutes ClpY ATPase/unfoldase and ClpQ peptidase. The Tyr91st residue within the central pore-I site of ClpY-hexamer is important for unfolding and translocating substrates into the catalytic site of ClpQ. We have identified the degron site (GFIMRP147th) of SulA, a cell-division inhibitor recognized by ClpYQ and that the Phe143rd residue in degron site is necessary for SulA native folded structure. However, the functional association of this degron site with the ClpYQ degrader is unknown. Here, we investigated the molecular insights into substrate recognition and discrimination by the ClpYQ protease. We found that the point mutants ClpYY91FQ, ClpYY91HQ, and ClpYY91WQ, carrying a ring structure at the 91st residue of ClpY, efficiently degraded their natural substrates, evidenced by the suppressed bacterial methyl-methane-sulfonate (MMS) sensitivity, the reduced β-galactosidase activity of cpsB::lacZ, and the lowest amounts of MBP-SulA in both in vivo and in vitro degradation analyses. Alternatively, mimicking the wild-type SulA, SulAF143H, SulAF143K and SulAF143W, harboring a ring structure or a cation side-group in 143rd residue of SulA, were efficiently degraded by ClpYQ in the bacterial cells, also revealing shorter half-lives at 41 °C and higher binding affinities towards ClpY in pull-down assays. Finally, ClpYY91FQ and ClpYY91HQ, were capable of effectively degrading SulAF143H and SulAF143K, highlighting a correspondingly functional interaction between the SulA 143rd and ClpY 91st residues. According to the interchangeable substituted amino acids, our results uniquely indicate that a transient π-π or cation-π interaction between the SulA 143rd and ClpY 91st residues could be aptly gripped between the degron site of substrates and the pore site of proteases (degraders) for substrate recognition and discrimination of the processive degradation.
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Affiliation(s)
- Chu-Hsuan Lin
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Chih-Hsuan Tsai
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701401, Taiwan
| | - Chun-Chi Chou
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Whei-Fen Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei 10617, Taiwan
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Kan YT, Wu WF, Yang YF. [A case of cystic fibrosis with cirrhosis as the main manifestation]. Zhonghua Gan Zang Bing Za Zhi 2023; 31:1087-1089. [PMID: 38016775 DOI: 10.3760/cma.j.cn501113-20230202-00030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Affiliation(s)
- Y T Kan
- Department of Hepatology, Nanjing Second Hospital, Nanjing, Jiangsu 210000, China The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Department of Hepatology
| | - W F Wu
- Department of Hepatology, Nanjing Second Hospital, Nanjing, Jiangsu 210000, China The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Department of Hepatology
| | - Y F Yang
- Department of Hepatology, Nanjing Second Hospital, Nanjing, Jiangsu 210000, China The Second Hospital of Nanjing, Affiliated to Nanjing University of Chinese Medicine, Department of Hepatology
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Kuan JE, Tsai CH, Chou CC, Wu C, Wu WF. Enzymatic Characterization of a Novel HSL Family IV Esterase EstD04 from Pseudomonas sp. D01 in Mealworm Gut Microbiota. Molecules 2023; 28:5410. [PMID: 37513282 PMCID: PMC10385968 DOI: 10.3390/molecules28145410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/06/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Pseudomonas sp. D01, capable of growing in tributyrin medium, was isolated from the gut microbiota of yellow mealworm. By using in silico analyses, we discovered a hypothesized esterase encoding gene in the D01 bacterium, and its encoded protein, EstD04, was classified as a bacterial hormone-sensitive lipase (bHSL) of the type IV lipase family. The study revealed that the recombinant EstD04-His(6x) protein exhibited esterase activity and broad substrate specificity, as it was capable of hydrolyzing p-nitrophenyl derivatives with different acyl chain lengths. By using the most favorable substrate p-nitrophenyl butyrate (C4), we defined the optimal temperature and pH value for EstD04 esterase activity as 40 °C and pH 8, respectively, with a catalytic efficiency (kcat/Km) of 6.17 × 103 mM-1 s-1 at 40 °C. EstD04 demonstrated high stability between pH 8 and 10, and thus, it might be capably used as an alkaline esterase in industrial applications. The addition of Mg2+ and NH4+, as well as DMSO, could stimulate EstD04 enzyme activity. Based on bioinformatic motif analyses and tertiary structural simulation, we determined EstD04 to be a typical bHSL protein with highly conserved motifs, including a triad catalytic center (Ser160, Glu253, and His283), two cap regions, hinge sites, and an oxyanion hole, which are important for the type IV enzyme activity. Moreover, the sequence analysis suggested that the two unique discrete cap regions of EstD04 may contribute to its alkali mesophilic nature, allowing EstD04 to exhibit extremely distinct physiological properties from its evolutionarily closest esterase.
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Affiliation(s)
- Jung-En Kuan
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Chih-Hsuan Tsai
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701401, Taiwan
| | - Chun-Chi Chou
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Cindy Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Whei-Fen Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei 10617, Taiwan
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Hsu YS, Liu YH, Lin CH, Tsai CH, Wu WF. Dual bio-degradative pathways of di-2-ethylhexyl phthalate by a novel bacterium Burkholderia sp. SP4. World J Microbiol Biotechnol 2023; 39:44. [DOI: 10.1007/s11274-022-03490-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022]
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Hsieh FC, Chang LK, Tsai CH, Kuan JE, Wu KF, Wu C, Wu WF. Roles of double-loop (130~159 aa and 175~209 aa) in ClpY(HslU)-I domain for SulA substrate degradation by ClpYQ(HslUV) protease in Escherichia coli. J GEN APPL MICROBIOL 2021; 66:297-306. [PMID: 32435002 DOI: 10.2323/jgam.2019.12.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
An Escherichia coli ATP-dependent two-component protease, ClpYQ(HslUV), targets the SulA molecule, an SOS induced protein. ClpY recognizes, unfolds and translocates the substrates into the proteolytic site of ClpQ for degradation. ClpY is divided into three domains N, I and C. The N domain is an ATPase; the C domain allows for oligomerization, while the I domain coordinates substrate binding. In the ClpYQ complex, two layer pore sites, pore I and II, are in the center of its hexameric rings. However, the actual roles of two outer-loop (130~159 aa, L1 and 175~209 aa, L2) of the ClpY-I domain for the degradation of SulA are unclear. In this study, with ATP, the MBP-SulA molecule was bound to ClpY oligomer(s). ClpYΔL1 (ClpY deleted of loop 1) oligomers revealed an excessive SulA-binding activity. With ClpQ, it showed increased proteolytic activity for SulA degradation. Yet, ClpYΔL2 formed fewer oligomers that retained less proteolytic activity, but still had increased SulA-binding activity. In contrast, ClpYΔpore I had a lower SulA-binding activity. ClpYΔ pore I ΔL2 showed the lowest SulA-binding activity. In addition, ClpY (Q198L, Q200L), with a double point mutation in loop 2, formed stable oligomers. It also had a subtle increase in SulA-binding activity, but displayed less proteolytic activity. As a result, loop 2 has an effect on ClpY oligomerization, substrate binding and delivery. Loop 1 has a role as a gate, to prevent excessive substrate binding. Thus, accordingly, ClpY permits the formation of SulA-ClpY(6x), with ATP(s), and this complex then docks through ClpQ(6x) for ultimate proteolytic degradation.
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Affiliation(s)
- Fan-Ching Hsieh
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University
| | - Lu-Kao Chang
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University
| | - Chih-Hsuan Tsai
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University
| | - Jung-En Kuan
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University
| | - Ke-Feng Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University
| | - Cindy Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University
| | - Whei-Fen Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University
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Abstract
Biological entities such as fungi in stored grain evolve and interact with the environment in similar fashions as physical fields. An experiment was conducted to study the behavior of the biological field of fungi in stored grain, as well as the interactions between the biological field of fungi and the physical fields of temperature and moisture. A framework of the biological field is presented to describe biological systems in which multiple biological entities co-exist and interact among themselves and with the surrounding environment. The proposed biological field describes the spatio-temporal distribution of a biological entity and its ability of influencing (or being influenced by) the surrounding biotic and abiotic entities through exchange of energy, matter, and/or information. The strength of a biological field of fungi was quantified as the rate of energy conversion by fungi from grain starch to heat. The experimental data showed that the strength of biological field of fungi in stored grain varied in both space and time, with the maximum field strength of 120-133 W m-3 occurred at the location where the biological field of fungi interacted strongly with the temperature and moisture fields.
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Affiliation(s)
- Z D Wu
- Jilin University, Changchun, China.
| | - Q Zhang
- University of Manitoba, Winnipeg, Manitoba, Canada.
| | - J Yin
- Academy of National Food and Strategic Reservation Administration, Beijing, China
| | - X M Wang
- Jilin University, Changchun, China
| | - Z J Zhang
- Academy of National Food and Strategic Reservation Administration, Beijing, China
| | - W F Wu
- Jilin University, Changchun, China
| | - F J Li
- Academy of National Food and Strategic Reservation Administration, Beijing, China
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Chien CW, Chan YF, Shih PS, Kuan JE, Wu KF, Wu C, Wu WF. Regulation of metE + mRNA expression by FnrS small RNA in Salmonella enterica serovar Typhimurium. Microbiol Res 2019; 229:126319. [PMID: 31479952 DOI: 10.1016/j.micres.2019.126319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/08/2019] [Accepted: 08/12/2019] [Indexed: 11/18/2022]
Abstract
Methionine is critical for variety of metabolic processes in biological organisms, acting as a precursor or intermediate for many final products. The last step for the synthesis of methionine is the methylation of homocysteine, which is catalyzed by MetE. Here, we use Salmonella enterica serovar Typhimurium LT2 to study the regulation of the metE+ gene by an anaerobically induced small non-coding RNA-FnrS, the expression of which is strictly dependent on the anaerobic regulator-FNR. The MetE-HA protein was expressed at an increased level in the fnrS- and hfq- deficient strains under anaerobic conditions. The Hfq protein is predicted to stabilize the binding between small RNA(s) and their target mRNA(s). A transcriptional (op) and translational (pr) metE::lacZ fusion gene were separately constructed, with the metE+-promoter fused to a lacZ reporter gene. In an anaerobic environment, the metE::lacZ (pr) fusion gene and reverse transcription-PCR identified that FnrS and/or FNR negatively regulate metE+ mRNA levels in the rich media. Analysis of FnrS revealed a sequence complementary to the 5' mRNA translational initiation region (TIR) of the metE+ gene. Mutation(s) predicted to disrupt base pairing between FnrS and metE+ TIR were constructed in fnrS, and most of those resulted in the loss of repressive activity. When compensatory mutation(s) were made in metE+ 5' TIR to restore base pairing with FnrS, the repressive regulation was completely restored. Therefore, in this study, we identified that in anaerobic phase, there is a repression of metE+ gene expression by FnrS and that base-paring, between both expressive transcripts, plays an important role for this negative regulation.
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MESH Headings
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- Base Pairing
- Base Sequence
- Gene Expression Regulation, Bacterial
- Gene Expression Regulation, Enzymologic
- Methyltransferases/chemistry
- Methyltransferases/genetics
- Methyltransferases/metabolism
- Nucleic Acid Conformation
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Small Untranslated/chemistry
- RNA, Small Untranslated/genetics
- RNA, Small Untranslated/metabolism
- Salmonella typhimurium/enzymology
- Salmonella typhimurium/genetics
- Salmonella typhimurium/metabolism
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Affiliation(s)
- Chia-Wei Chien
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan, ROC
| | - Yu-Feng Chan
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan, ROC
| | - Po-Shu Shih
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan, ROC
| | - Jung-En Kuan
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan, ROC
| | - Ke-Feng Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan, ROC
| | - Cindy Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan, ROC
| | - Whei-Fen Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan, ROC.
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Wen WH, Wu WF, Wang X, Wu Y, Kuang ZM, Wang LY. [Interpretation of the Japanese guidance for pediatric familial hypercholesterolemia 2017]. Zhonghua Xin Xue Guan Bing Za Zhi 2019; 47:417-420. [PMID: 31142091 DOI: 10.3760/cma.j.issn.0253-3758.2019.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- W H Wen
- Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China
| | - W F Wu
- Emergency & Critical Care Center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China
| | - X Wang
- Emergency & Critical Care Center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China
| | - Y Wu
- Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China
| | - Z M Kuang
- Department of Hyptension, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China
| | - L Y Wang
- Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China
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Xue YM, Chen MG, Chen DW, Wu WF, Liu YL, Lin FH. [The effect of microRNA-21 on myocardial fibrosis in mice with chronic viral myocarditis]. Zhonghua Xin Xue Guan Bing Za Zhi 2019; 46:450-457. [PMID: 29925181 DOI: 10.3760/cma.j.issn.0253-3758.2018.06.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To explore the effect of microRNA-21 (miR-21) on myocardial fibrosis in mice with chronic viral myocarditis (CVMC) and related mechanisms. Methods: Forty 4-week-old Balb/c male mice were randomly divided into 4 groups (n=10 each): phosphate buffer saline (PBS) group, CVMC group, CVMC+miR-21 inhibitor group, CVMC+isotype control group. The first injection of Coxsackie virus B3 (CVB3) or PBS was performed on day 0, and the total study time was 42 days. Each mouse in CVMC group, CVMC+miR-21 inhibitor group and CVMC+isotype control group was intraperitoneally (i.p) injected with 100TCID50 CVB3 0.1, 0.15, and 0.2 ml on day 0, 14, and 28, respectively. The mice in PBS group were i.p injected with the same dose of PBS at the same time point. After the initial infection, each mouse in CVMC+miR-21 inhibitor group and CVMC+isotype control group was intravenously injected with 0.1 ml miR-21 inhibitor or 0.1 ml isotype control, on day 14 and 28. Cardiac function was measured on surviving mice of 4 groups by echocardiography on day 42. Then, the hearts were removed aseptically to observe the expressions of green fluorescence protein (GFP). The myocardial pathological changes were examined with HE, Masson staining and the myocardial pathological scores (PS), the collagen volume fraction (CVF) were calculated respectively. The levels of miR-21, collagen typeⅠ-A1 (COL1-A1) and collagen type Ⅲ-A1 (COL3-A1) mRNA in heart were detected by quantitative real-time polymerase chain reaction (RT-qPCR). Furthermore, the expressions of transforming growth factor-β1 (TGF-β1) and mothers against decapentaplegic homolog 7(Smad7) in heart were determined with Western blot assay. Results: (1) Cardiac function in 4 groups: Compared with PBS group, left ventricular end systolic diameter (LVESD) and left ventricular end diastolic diameter (LVEDD) were markedly increased in CVMC group and CVMC+isotype control group (all P<0.05), whereas the left ventricular ejection fraction (LVEF) was decreased (P<0.05). LVESD and LVEDD were significantly decreased, and LVEF was increased in CVMC+miR-21 inhibitor group compared with those in CVMC group and CVMC+isotype control group (all P<0.05). (2) Myocardial pathological changes: The expressions of GFP in CVMC+miR-21 inhibitor group and CVMC+isotype control group were visible in heart tissues frozen sections. The hearts in CVMC group and CVMC+isotype control group were enlarged and stiff, inflammatory cells were visible and significantly increased myocardial fibrosis was evidenced in mice of these two groups. Higher PS and CVF were evidenced in CVMC group (PS: 1.14±0.69 vs. 0, CVF: (17.86±2.61)% vs. (5.70±1.42)%, all P<0.05) and CVMC+isotype control group(PS: 1.00±0.63 vs. 0, CVF: (16.78±2.58)% vs. (5.70±1.42)%, all P<0.05) compared to PBS group. Compared with CVMC group and CVMC+isotype control group, degree of cardiac fibrosis was reduced in mice of CVMC+miR-21 inhibitor group (CVF: (11.01±2.55)% vs. (17.86±2.61)%, (11.01±2.55)% vs. (16.78±2.58)%, all P<0.05), whereas PS were similar between them (PS: 0.89±0.60 vs. 1.14±0.69, 0.89±0.60 vs. 1.00±0.63, all P>0.05). (3) Cardiac expressions of miR-21, COL1-A1 and COL3-A1 mRNA: The cardiac expressions of miR-21, COL1-A1 mRNA, COL3-A1mRNA in CVMC group and CVMC+isotype control group were markedly higher than those in PBS group (all P<0.05), which were significantly downregulated in CVMC+miR-21 inhibitor group (all P<0.05 vs. CVMC group and CVMC+isotype control group). (4) The cardiac expressions of TGF-β1 and Smad7 protein: The cardiac expressions of TGF-β1 protein in CVMC group and CVMC+isotype control group were markedly higher, whereas the cardiac Smad7 protein expressions were significantly lower (all P<0.05) than those in PBS group (all P<0.05), these changes could be reversed in CVMC+miR-21 inhibitor group (P<0.05 vs. CVMC group and CVMC+isotype control group). Conclusions: Our results suggest that miR-21 contributes to the myocardial fibrosis in CVMC mice through modulating TGF-β1/Smad7 signaling pathway.
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Affiliation(s)
- Y M Xue
- Fourth Department of Critical Care Medicine, Fujian Provincial Hospital, Provincial Clinical College of Fujian Medical University, Fuzhou 350001, China
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Tsai CH, Ho YH, Sung TC, Wu WF, Chen CS. Escherichia coli Proteome Microarrays Identified the Substrates of ClpYQ Protease. Mol Cell Proteomics 2016; 16:113-120. [PMID: 27864322 DOI: 10.1074/mcp.m116.065482] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Indexed: 01/12/2023] Open
Abstract
Proteolysis is a vital mechanism to regulate the cellular proteome in all kingdoms of life, and ATP-dependent proteases play a crucial role within this process. In Escherichia coli, ClpYQ is one of the primary ATP-dependent proteases. In addition to function with removals of abnormal peptides in the cells, ClpYQ degrades regulatory proteins if necessary and thus let cells adjust to various environmental conditions. In E. coli, SulA, RcsA, RpoH and TraJ as well as RNase R, have been identified as natural protein substrates of ClpYQ. ClpYQ contains ClpY and ClpQ. The ATPase ClpY is responsible for protein recognition, unfolding, and translocation into the catalytic core of ClpQ. In this study, we use an indirect identification strategy to screen possible ClpY targets with E. coli K12 proteome chips. The chip assay results showed that YbaB strongly bound to ClpY. We used yeast two-hybrid assay to confirm the interactions between ClpY and YbaB protein and determined the Kd between ClpY and YbaB by quartz crystal microbalance. Furthermore, we validated that YbaB was successfully degraded by ClpYQ protease activity using ClpYQ in vitro and in vivo degradation assay. These findings demonstrated the YbaB is a novel substrate of ClpYQ protease. This work also successfully demonstrated that with the use of recognition element of a protease can successfully screen its substrates by indirect proteome chip screening assay.
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Affiliation(s)
- Chih-Hsuan Tsai
- From the ‡Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan
| | - Yu-Hsuan Ho
- §Graduate Institute of Systems Biology and Bioinformatics, National Central University, No. 300, Jhongda Rd., Jhongli 32001, Taiwan.,¶Department of Biomedical Sciences and Engineering, National Central University, No. 300, Jhongda Rd., Jhongli 32001, Taiwan
| | - Tzu-Cheng Sung
- §Graduate Institute of Systems Biology and Bioinformatics, National Central University, No. 300, Jhongda Rd., Jhongli 32001, Taiwan.,¶Department of Biomedical Sciences and Engineering, National Central University, No. 300, Jhongda Rd., Jhongli 32001, Taiwan
| | - Whei-Fen Wu
- From the ‡Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan;
| | - Chien-Sheng Chen
- §Graduate Institute of Systems Biology and Bioinformatics, National Central University, No. 300, Jhongda Rd., Jhongli 32001, Taiwan; .,¶Department of Biomedical Sciences and Engineering, National Central University, No. 300, Jhongda Rd., Jhongli 32001, Taiwan
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Chang CY, Hu HT, Tsai CH, Wu WF. The degradation of RcsA by ClpYQ(HslUV) protease in Escherichia coli. Microbiol Res 2016; 184:42-50. [PMID: 26856452 DOI: 10.1016/j.micres.2016.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 12/21/2015] [Accepted: 01/09/2016] [Indexed: 01/30/2023]
Abstract
In Escherichia coli, RcsA, a positive activator for transcription of cps (capsular polysaccharide synthesis) genes, is degraded by the Lon protease. In lon mutant, the accumulation of RcsA leads to overexpression of capsular polysaccharide. In a previous study, overproduction of ClpYQ(HslUV) protease represses the expression of cpsB∷lacZ, but there has been no direct observation demonstrating that ClpYQ degrades RcsA. By means of a MBP-RcsA fusion protein, we showed that RcsA activated cpsB∷lacZ expression and could be rapidly degraded by Lon protease in SG22622 (lon(+)). Subsequently, the comparative half-life experiments performed in the bacterial strains SG22623 (lon) and AC3112 (lon clpY clpQ) indicated that the RcsA turnover rate in AC3112 was relatively slow and RcsA was stable at 30°C or 41°C. In addition, ClpY could interact with RscA in an in vitro pull-down assay, and the more rapid degradation of RcsA was observed in the presence of ClpYQ protease at 41°C. Thus, we conclude that RcsA is indeed proteolized by ClpYQ protease.
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Affiliation(s)
- Chun-Yang Chang
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan, ROC
| | - Hui-Ting Hu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan, ROC
| | - Chih-Hsuan Tsai
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan, ROC
| | - Whei-Fen Wu
- Department of Agricultural Chemistry, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan, ROC.
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13
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Wan KS, Wu WF, Chen TC, Wu CS, Hung CW, Chang YS. Comparison of amoxicillin + clavulanate with or without intranasal fluticasone for the treatment of uncomplicated acute rhinosinusitis in children. Minerva Pediatr 2015; 67:489-494. [PMID: 26530491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
AIM Intranasal corticosteroids (INS) have been proven effective in controlling postnasal drip, decreasing inflammatory response, reducing nasal swelling, and increasing aeration of the sinuses such that INS are recommended as treatment of sinusitis. METHODS Fifty children with acute rhinosinusitis, 50 children with acute rhiniosinusitis and allergic rhinitis (AR), and 20 rhiniosinusitis children as control were selected for investigation. Each group had a single-blind treatment of three types: with coamoxiclav only, with coamoxiclav plus INS, and with matched placebo (without antibiotics and INS) for two weeks. Nasal symptoms were then evaluated. The outcome was measured by using major symptom score (MSS) after treatment for 14 days. RESULTS Therapeutic effectiveness was 92% in rhinosinusitis patients treated with co-amoxiclav and 84% in those treated with co-amoxiclav plus INS. Among patients with sinusitis combined with AR, therapeutic efficacy was 88% for those treated with co-amoxiclav and 96% for those treated with co-amoxiclav plus INS. Only 30% of the symptoms were reduced in the placebo group. CONCLUSION There are no statistical differences in the acute sinusitis group treated with co-amoxiclav with or without INS. In the sinusitis with AR group, the efficacy of co-amoxiclav with INS is higher than in children treated with co-amoxiclav alone.
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Affiliation(s)
- K S Wan
- Department of Pediatrics, Taipei City Hospital, Renai Branch, Taiwan -
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Wu WF, Wang FP, Li JH, Yang XW, Xiao X, Pan YX. Iron reduction and mineralization of deep-sea iron reducing bacterium Shewanella piezotolerans WP3 at elevated hydrostatic pressures. Geobiology 2013; 11:593-601. [PMID: 24102974 DOI: 10.1111/gbi.12061] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 08/20/2013] [Indexed: 06/02/2023]
Abstract
In this study, iron reduction and concomitant biomineralization of a deep-sea iron reducing bacterium (IRB), Shewanella piezotolerans WP3, were systematically examined at different hydrostatic pressures (0.1, 5, 20, and 50 MPa). Our results indicate that bacterial iron reduction and induced biomineralization are influenced by hydrostatic pressure. Specifically, the iron reduction rate and extent consistently decreases with the increase in hydrostatic pressure. By extrapolation, the iron reduction rate should drop to zero by ~68 MPa, which suggests a possible shut-off of enzymatic iron reduction of WP3 at this pressure. Nano-sized superparamagnetic magnetite minerals are formed under all the experimental pressures; nevertheless, even as magnetite production decreases, the crystallinity and grain size of magnetite minerals increase at higher pressure. These results imply that IRB may play an important role in iron reduction, biomineralization, and biogeochemical cycling in deep-sea environments.
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Affiliation(s)
- W F Wu
- Biogeomagnetism Group, Paleomagnetism and Geochronology Lab, Key Laboratory of the Earth's Deep Interior, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China; France-China Bio-Mineralization and Nano-Structures Laboratory, Chinese Academy of Sciences, Beijing, China
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15
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Yang C, Huang TW, Wen SY, Chang CY, Tsai SF, Wu WF, Chang CH. Genome-wide PhoB binding and gene expression profiles reveal the hierarchical gene regulatory network of phosphate starvation in Escherichia coli. PLoS One 2012; 7:e47314. [PMID: 23071782 PMCID: PMC3465305 DOI: 10.1371/journal.pone.0047314] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 09/13/2012] [Indexed: 11/19/2022] Open
Abstract
The phosphate starvation response in bacteria has been studied extensively for the past few decades and the phosphate-limiting signal is known to be mediated via the PhoBR two-component system. However, the global DNA binding profile of the response regulator PhoB and the PhoB downstream responses are currently unclear. In this study, chromatin immunoprecipitation for PhoB was combined with high-density tiling array (ChIP-chip) as well as gene expression microarray to reveal the first global down-stream responses of the responding regulator, PhoB in E. coli. Based on our ChIP-chip experimental data, forty-three binding sites were identified throughout the genome and the known PhoB binding pattern was updated by identifying the conserved pattern from these sites. From the gene expression microarray data analysis, 287 differentially expressed genes were identified in the presence of PhoB activity. By comparing the results obtained from our ChIP-chip and microarray experiments, we were also able to identify genes that were directly or indirectly affected through PhoB regulation. Nineteen out of these 287 differentially expressed genes were identified as the genes directly regulated by PhoB. Seven of the 19 directly regulated genes (including phoB) are transcriptional regulators. These transcriptional regulators then further pass the signal of phosphate starvation down to the remaining differentially expressed genes. Our results unveiled the genome-wide binding profile of PhoB and the downstream responses under phosphate starvation. We also present the hierarchical structure of the phosphate sensing regulatory network. The data suggest that PhoB plays protective roles in membrane integrity and oxidative stress reduction during phosphate starvation.
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Affiliation(s)
- Chi Yang
- Institute of Biomedical Informatics, Center for Systems and Synthetic Biology, National Yang Ming University, Taipei, Taiwan
| | - Tzu-Wen Huang
- Division of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Shiau-Yi Wen
- Institute of Biomedical Informatics, Center for Systems and Synthetic Biology, National Yang Ming University, Taipei, Taiwan
| | - Chun-Yang Chang
- Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan
| | - Shih-Feng Tsai
- Division of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Whei-Fen Wu
- Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan
| | - Chuan-Hsiung Chang
- Institute of Biomedical Informatics, Center for Systems and Synthetic Biology, National Yang Ming University, Taipei, Taiwan
- Center for Systems and Synthetic Biology, National Yang Ming University, Taipei, Taiwan
- * E-mail:
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16
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Wu WF, Wan KS, Wang SJ, Yang W, Liu WL. Prevalence, severity, and time trends of allergic conditions in 6-to-7-year-old schoolchildren in Taipei. J Investig Allergol Clin Immunol 2011; 21:556-562. [PMID: 22312941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
BACKGROUND Atopic diseases, including asthma, allergic rhinitis, and atopic eczema, are major illnesses among children. Recent studies conducted worldwide have shown diverse trends in the prevalence of asthma, with a steady increase detected in industrialized countries. Other studies, however, have revealed a leveling trend or even a declining prevalence. OBJECTIVE The purpose of this study was to evaluate the current prevalence of allergic conditions in 6-to7-year-old schoolchildren in Taipei, Taiwan, and to analyze time trends. METHODS We evaluated the prevalence and severity of asthma and other allergic conditions using a phase I International Study of Asthma and Allergies in Childhood core written questionnaire previously administered in Taipei in 1994 and 2002. RESULTS A total of 24 999 first-grade students from 153 elementary schools completed the questionnaire. The proportion of children with wheeze ever and nocturnal cough in the past 12 months was significantly increased in 2007 compared to 1994 and 2002. No significant differences were detected in the prevalence of current wheeze or physician-diagnosed asthma. The prevalence of severe wheezing symptoms in the past 12 months (> or = 4 attacks of wheeze, > or = 1 night of sleep disturbance due to wheeze per week, wheeze-limiting speech, and exercise-induced wheeze) decreased significantly. The prevalence and severity of rhinitis symptoms increased significantly during the 13-year period analyzed. The prevalence of eczema symptoms-defined as recurrent itchy rash and typical atopic eczema distribution in the past 12 months--also increased. CONCLUSIONS We observed an increase only in the prevalence and severity of current allergic symptoms in allergic rhinitis and atopic eczema.
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Affiliation(s)
- W F Wu
- Department of Pediatrics, Taipei City Hospital, Ren-Ai Branch, Taipei, Taiwan
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17
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Chiang BY, Chen TC, Pai CH, Chou CC, Chen HH, Ko TP, Hsu WH, Chang CY, Wu WF, Wang AHJ, Lin CH. Protein S-thiolation by Glutathionylspermidine (Gsp): the role of Escherichia coli Gsp synthetASE/amidase in redox regulation. J Biol Chem 2010; 285:25345-53. [PMID: 20530482 DOI: 10.1074/jbc.m110.133363] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Certain bacteria synthesize glutathionylspermidine (Gsp), from GSH and spermidine. Escherichia coli Gsp synthetase/amidase (GspSA) catalyzes both the synthesis and hydrolysis of Gsp. Prior to the work reported herein, the physiological role(s) of Gsp or how the two opposing GspSA activities are regulated had not been elucidated. We report that Gsp-modified proteins from E. coli contain mixed disulfides of Gsp and protein thiols, representing a new type of post-translational modification formerly undocumented. The level of these proteins is increased by oxidative stress. We attribute the accumulation of such proteins to the selective inactivation of GspSA amidase activity. X-ray crystallography and a chemical modification study indicated that the catalytic cysteine thiol of the GspSA amidase domain is transiently inactivated by H(2)O(2) oxidation to sulfenic acid, which is stabilized by a very short hydrogen bond with a water molecule. We propose a set of reactions that explains how the levels of Gsp and Gsp S-thiolated proteins are modulated in response to oxidative stress. The hypersensitivities of GspSA and GspSA/glutaredoxin null mutants to H(2)O(2) support the idea that GspSA and glutaredoxin act synergistically to regulate the redox environment of E. coli.
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Affiliation(s)
- Bing-Yu Chiang
- Institute of Biological Chemistry, Facilities for Proteomics Research, Academia Sinica, 128 Academia Road, Section 2, Taipei 11529, Taiwan
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18
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Wang P, Luo JD, Wu WF, Wang S, Cai SL, Shen BH, Shi SF, Wei KX, Zhang ZG, Chen ZD. Multiple factor analysis of metachronous upper urinary tract transitional cell carcinoma after radical cystectomy. Braz J Med Biol Res 2007; 40:979-84. [PMID: 17653452 DOI: 10.1590/s0100-879x2006005000104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2006] [Accepted: 02/02/2007] [Indexed: 11/22/2022] Open
Abstract
Transitional cell carcinoma (TCC) of the urothelium is often multifocal and subsequent tumors may occur anywhere in the urinary tract after the treatment of a primary carcinoma. Patients initially presenting a bladder cancer are at significant risk of developing metachronous tumors in the upper urinary tract (UUT). We evaluated the prognostic factors of primary invasive bladder cancer that may predict a metachronous UUT TCC after radical cystectomy. The records of 476 patients who underwent radical cystectomy for primary invasive bladder TCC from 1989 to 2001 were reviewed retrospectively. The prognostic factors of UUT TCC were determined by multivariate analysis using the COX proportional hazards regression model. Kaplan-Meier analysis was also used to assess the variable incidence of UUT TCC according to different risk factors. Twenty-two patients (4.6%). developed metachronous UUT TCC. Multiplicity, prostatic urethral involvement by the bladder cancer and the associated carcinoma in situ (CIS) were significant and independent factors affecting the occurrence of metachronous UUT TCC (P = 0.0425, 0.0082, and 0.0006, respectively). These results were supported, to some extent, by analysis of the UUT TCC disease-free rate by the Kaplan-Meier method, whereby patients with prostatic urethral involvement or with associated CIS demonstrated a significantly lower metachronous UUT TCC disease-free rate than patients without prostatic urethral involvement or without associated CIS (log-rank test, P = 0.0116 and 0.0075, respectively). Multiple tumors, prostatic urethral involvement and associated CIS were risk factors for metachronous UUT TCC, a conclusion that may be useful for designing follow-up strategies for primary invasive bladder cancer after radical cystectomy.
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Affiliation(s)
- P Wang
- Department of Urology, The First Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, Zhejiang Province, China
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19
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Lian YX, Long XY, Wu WF. [Clinical and experimental study of shuangcao tuihuang granule-1 in treating severe jaundice of acute icterohepatitis]. Zhongguo Zhong Xi Yi Jie He Za Zhi 2001; 21:649-51. [PMID: 12575547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To observe the effect of Shuangcao Tuihuang Granule-1 (SCTH-1) in treating severe jaundice of acute icterohepatitis and to study its mechanism. METHODS Thirty-four patients with severe jaundice of acute icterohepatitis were treated with SCTH-1, their therapeutic effects were analyzed. In the experimental studies, the influences of SCTH-1 on acute liver injury, liver superoxide dismutase (SOD) and serum ALT and AST were monitored. RESULTS The markedly effective rate and effective rate of the treated group were 73.5% and 23.5% respectively. The markedly effective rate of the treated group was obviously higher than that of the control group (P < 0.05). Experimental study revealed that SCTH-1 could reduce the level of serum transaminase and inflammation of liver tissue in mice with acute liver damage. In addition, SCTH-1 could raise the activity of liver SOD (P < 0.05). CONCLUSION SCTH-1 could accelerate the jaundice subsidence, improve the liver function and ameliorate the liver injury, its mechanism was possibly correlated with raising SOD activity, scavenging the oxygen free radicals.
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Affiliation(s)
- Y X Lian
- Guangzhou 8th People's Hospital of Guangdong Province, Guangzhou 510060
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20
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Jan JS, Wu WF. Acute effect of glucocorticoid treatment on serum osteocalcin levels in asthmatic children. J Microbiol Immunol Infect 2000; 33:25-8. [PMID: 10806960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The serum levels of osteocalcin (OC), a sensitive and specific biochemical marker of bone formation, were measured in 36 asthmatic children before and after intravenous administration of glucocorticoid (GC), methylprednisolone (1 mg/kg/6 h). A statistically significant (p < 0.005) decrease in OC level (13.5-2.7 microg/L) after the completion of 1-day treatment. In patients who received 2-day treatment, the OC levels further declined and reached about 20% of the pretreatment levels. Blood samples collected from patients who received 3-day treatment showed serum OC had declined to an even lower level after the completion of therapy (11.5-1.8 microg/L). An inverse relationship was found between the OC concentration and the duration of GC therapy. GC therapy induced a minor, significant decrease of serum alkaline phosphatase level but did not influence serum calcium level. A tendency toward decrease of serum phosphate level was also noted during GC treatment. An acute effect of GC therapy on the suppression of osteoblasts was biochemically revealed by the finding of reduced serum OC levels. The results suggest that early change in serum OC may be a useful indicator for patients at high risk of bone loss.
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Affiliation(s)
- J S Jan
- Department of Pediatrics, Taipei Municipal Jen Ai Hospital, Taiwan, ROC
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Abstract
The ClpYQ (HslUV) ATP-dependent protease of Escherichia coli consists of an ATPase subunit closely related to the Clp ATPases and a protease component related to those found in the eukaryotic proteasome. We found that this protease has a substrate specificity overlapping that of the Lon protease, another ATP-dependent protease in which a single subunit contains both the proteolytic active site and the ATPase. Lon is responsible for the degradation of the cell division inhibitor SulA; lon mutants are UV sensitive, due to the stabilization of SulA. lon mutants are also mucoid, due to the stabilization of another Lon substrate, the positive regulator of capsule transcription, RcsA. The overproduction of ClpYQ suppresses both of these phenotypes, and the suppression of UV sensitivity is accompanied by a restoration of the rapid degradation of SulA. Inactivation of the chromosomal copy of clpY or clpQ leads to further stabilization of SulA in a lon mutant but not in lon+ cells. While either lon, lon clpY, or lon clpQ mutants are UV sensitive at low temperatures, at elevated temperatures the lon mutant loses its UV sensitivity, while the double mutants do not. Therefore, the degradation of SulA by ClpYQ at elevated temperatures is sufficient to lead to UV resistance. Thus, a protease with a structure and an active site different from those of Lon is capable of recognizing and degrading two different Lon substrates and appears to act as a backup for Lon under certain conditions.
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Affiliation(s)
- W F Wu
- Laboratory of Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892-4255, USA
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Abstract
Transcription of the metE gene in Salmonella typhimurium and Escherichia coli is positively regulated by the MetR protein, with homocysteine serving as a coactivator. It was shown previously that MetR binds to and protects from DNase I digestion a 24-bp sequence in the metE metR regulatory region from nucleotides -48 to -71 relative to the metE transcription initiation site (designated as site 1). In this study, we show that purified MetR protein also binds to and protects a second 24-bp sequence adjacent to the original site, from nucleotides -24 to -47 relative to the metE transcription initiation site (designated as site 2). Single and multiple base changes were introduced into sites 1 and 2 in a metE-lacZ fusion. Base pair changes in site 1 or site 2 away from the MetR consensus binding sequence resulted in decreased metE-lacZ expression, suggesting that both sites are necessary for expression. DNase I footprint analysis showed that MetR bound at the high-affinity site 1 enhances MetR binding at the low-affinity site 2. A 2-bp change in site 2 toward the MetR consensus binding sequence resulted in high metE-lacZ expression; the increased expression was MetR dependent but homocysteine independent.
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Affiliation(s)
- W F Wu
- Department of Microbiology, University of Iowa, Iowa City 52242
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Wu WF, Urbanowski ML, Stauffer GV. MetJ-mediated regulation of the Salmonella typhimurium metE and metR genes occurs through a common operator region. FEMS Microbiol Lett 1993; 108:145-50. [PMID: 8486240 DOI: 10.1111/j.1574-6968.1993.tb06090.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In Salmonella typhimurium the metE and metR promoters overlap and are divergently transcribed. Three tandem repeats of an 8 bp sequence defined previously as the metE operator site for MetJ-mediated repression also overlap the -35 region of the metR promoter. Starting with a metE-lacZ.metR-galK double gene fusion, site-directed mutagenesis was used to change nucleotides in each of the repeat units from the consensus sequence. Each mutation, along with the wild-type metE-lacZ.metR-galK gene fusion, was cloned into phage lambda gt2. Regulation of the metE and metR genes was examined by measuring beta-galactosidase and galactokinase levels in Escherichia coli strains lysogenized with phage carrying the wild-type and mutant fusions. Mutations in each of the 8 bp repeat units disrupt MetJ-mediated repression for both the metE-lacZ and metR-galK gene fusions, suggesting that the metE and metR genes share a common operator site for the MetJ repressor.
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Affiliation(s)
- W F Wu
- Department of Microbiology, University of Iowa, Iowa City 52242
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Huang CP, Wu WF, Chiang TP, Horne CC, Yeh YS, Huang TW. [Pancreatoblastoma: report of one case]. Zhonghua Min Guo Xiao Er Ke Yi Xue Hui Za Zhi 1992; 33:388-96. [PMID: 1296451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Pancreatoblastoma is an extremely rare pancreatic tumor in childhood, comprising 0.5% of pancreatic non-endocrine tumors. It mostly affects children of under 8 years old without special sexual predilection. Abdominal mass is the dominant clinical feature and abdominal X-ray, sonography, UGI series, CT scan are of assistance in establishing diagnosis. The presence of acinar cells with zymogen granules, squamous metaplasia and endocrine components makes the diagnosis. We report a case of 4-year-old girl, who suffered from abdominal pain for two months. Abdominal mass was found at our OPD and abdominal sonography, UGI series, CT scan all indicated a parapancreatic tumor. AFP was 4700 ng/ml. Laparotomy confirmed a pancreatic tumor and only partial excision was performed due to tumor invasion and adhesion to major vessels. Diagnosis of pancreatoblastoma was made by pathohistology, cytochemical special stains and electronic microscopic examination of the tumor. Neither chemotherapy nor radiotherapy was performed due to family refusal. Then patient followed up at NTUH OPD regularly. Unfortunately patient expired because of the regrowth of residual tumor eight months later.
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Affiliation(s)
- C P Huang
- Department of Pediatrics, Taipei Municipal Jen-Ai Hospital, Taiwan, R.O.C
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Abstract
The vitamin B12 (B12)-mediated repression of the metE gene in Escherichia coli and Salmonella typhimurium requires the B12-dependent transmethylase, the metH gene product. It has been proposed that the MetH-B12 holoenzyme complex is involved directly in the repression mechanism. Using Escherichia coli strains lysogenized with a lambda phage carrying a metE-lacZ gene fusion, we examined B12-mediated repression of the metE-lacZ gene fusion. Although B12 supplementation results in a 10-fold repression of metE-lacZ expression, homocysteine addition to the growth medium overrides the B12-mediated repression. In addition, B12-mediated repression of the metE-lacZ fusion is dependent on a functional MetR protein. When a metB mutant was transformed with a high-copy-number plasmid carrying the metE gene, which would be expected to reduce intracellular levels of homocysteine, metE-lacZ expression was reduced and B12 supplementation had no further effect. In a metJ mutant, B12 represses metE-lacZ expression less than twofold. When the metJ mutant was transformed with a high-copy-number plasmid carrying the metH gene, which would be expected to reduce intracellular levels of homocysteine, B12 repression of the metE-lacZ fusion was partially restored. The results indicate that B12-mediated repression of the metE gene is primarily a loss of MetR-mediated activation due to depletion of the coactivator homocysteine, rather than a direct repression by the MetH-B12 holoenzyme.
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Affiliation(s)
- W F Wu
- Department of Microbiology, University of Iowa, Iowa City 52242
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Moss-Salentijn L, Kember NF, Shinozuka M, Wu WF, Bose A. Computer simulations of chondrocytic clone behaviour in rabbit growth plates. J Anat 1991; 175:7-17. [PMID: 2050577 PMCID: PMC1224465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The growth behaviour of chondrocytic clones in the cell columns of the proximal tibial growth plates of young rabbits was modelled in computer simulations. Simulations were performed, modelling either clones in large groups of columns or clones in one single column. The former were based on morphological data and measurements of cell columns from an earlier study while the latter utilised previous findings of cellular kinetics in rabbit growth plates. Simulation results that resembled most closely the actual observations on rabbit growth plates were those in which a distribution of values was assumed both for clone length (ranging from 1000 to 2000 microns) and for the lengths of the discontinuities between clones. When the assumption was made in the models that the disappearing (metaphyseal) end of an 'old' clone moved more rapidly than the developing (epiphyseal) end of a 'new' clone, replacing the former, the length of the discontinuity between these two clones increased with time. This assumption, which could be modelled in the simulations of clones in a single column based on cell growth behaviour, was found to provide an explanation for an earlier finding that there are more short columns at the epiphyseal side than at the metaphyseal side of a growth plate.
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Affiliation(s)
- L Moss-Salentijn
- Department of Anatomy and Cell Biology, Columbia University, New York, NY 10032
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Abstract
The large subunit of phage lambda terminase, gpA, the gene product of the phage A gene, interacts with the small subunit, gpNul, to form functional terminase. Terminase binds to lambda DNA at cosB to form a binary complex. The terminase:DNA complex binds a prohead to form a ternary complex. Ternary complex formation involves an interaction of the prohead with gpA. The amino terminus of gpA contains a functional domain for interaction with gpNul, and the carboxy-terminal 38 amino acids of gpA contain a functional domain for prohead binding. This information about the structure of gpA was obtained through the use of hybrid phages resulting from recombination between lambda and the related phage 21. lambda and 21 encode terminases that are analogous in structural organization and have ca. 60% sequence identity. In spite of these similarities, lambda and 21 terminases differ in specificity for DNA binding, subunit assembly, and prohead binding. A lambda-21 hybrid phage produces a terminase in which one of the subunits is chimeric and had recombinant specificities. In the work reported here; a new hybrid, lambda-21 hybrid 67, is characterized. lambda-21 hybrid 67 is the result of a crossover between lambda and 21 in the large subunit genes, such that the DNA from the left chromosome end is from 21, including cosB phi 21, the 1 gene, and the first 48 codons for the 2 gene. The rest of the hybrid 67 chromosome is lambda DNA, including 593 codons of the A gene. The chimeric gp2/A of hybrid 67 binds gp1 to form functional terminase.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- W F Wu
- Department of Microbiology, College of Medicine, University of Iowa, Iowa City 52242
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Wu WF. [Treatment of chronic virus hepatitis with Chinese medicinal herbs--man gan ning]. Zhong Xi Yi Jie He Za Zhi 1985; 5:347-9, 324. [PMID: 3161651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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