32 results on '"Qin, Anqi"'
Search Results
2. Discovery of Novel Dual Inhibitors Targeting Mutant IDH1 and NAMPT for the Treatment of Glioma with IDH1Mutation.
- Author
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Wen, Fei, Gui, Gang, Wang, Xiaoyu, Qin, Anqi, Ma, Tianfang, Chen, Hui, Li, Chunzheng, and Zha, Xiaoming
- Published
- 2024
- Full Text
- View/download PDF
3. Harvesting Vibration Energy for Efficient Cocatalyst-Free Sonocatalytic H 2 Production over Magnetically Separable Ultra-Low-Cost Fe 3 O 4.
- Author
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Zhang, Kailai, Sun, Xiaodong, Hu, Haijun, Qin, Anqi, Huang, Hongwei, Yao, Yali, Zhang, Yusheng, and Ma, Tianyi
- Subjects
IRON oxides ,ENERGY harvesting ,MECHANICAL energy ,CHEMICAL energy ,ULTRASONIC equipment ,MAGNETIC fields - Abstract
The cavitation effect is an important geochemical phenomenon, which generally exists under strong hydrodynamic conditions. Therefore, developing an economical and effective sonocatalyst becomes a vital method in capitalizing on the cavitation effect for energy generation. In this study, we first report a novel Fe
3 O4 sonocatalyst that can be easily separated using a magnetic field and does not require any additional cocatalysts for H2 production from H2 O. When subjected to ultrasonic vibration, this catalyst achieves an impressive H2 production rate of up to 175 μmol/h/USD (where USD stands for dollars), surpassing most previously reported mechanical catalytic materials. Furthermore, the ease and efficiency of separating this catalyst using an external magnetic field, coupled with its effortless recovery, highlight its significant potential for practical applications. By addressing the key limitations of conventional sonocatalysts, our study not only demonstrates the feasibility of using Fe3 O4 as a highly efficient sonocatalyst but also showcases the exciting possibility of using a new class of magnetically separable sonocatalysts to productively transform mechanical energy into chemical energy. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
4. Defect Engineered Microcrystalline Cellulose for Enhanced Cocatalyst‐Free Piezo‐Catalytic H2 Production.
- Author
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Zhang, Kailai, Sun, Xiaodong, Hu, Haijun, Yan, Ge, Qin, Anqi, Ma, Yali, Huang, Hongwei, and Ma, Tianyi
- Published
- 2023
- Full Text
- View/download PDF
5. Calcineurin plays a modulatory role in loading-induced regulation of type I myosin heavy chain gene expression in slow skeletal muscle
- Author
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Pandorf, Clay E., Jiang, Weihua H., Qin, Anqi X., Bodell, Paul W., Baldwin, Kenneth M., and Haddad, Fadia
- Subjects
Myosin -- Genetic aspects ,Myosin -- Physiological aspects ,Myosin -- Research ,Gene expression -- Research ,Muscle proteins -- Physiological aspects ,Muscle proteins -- Genetic aspects ,Muscle proteins -- Research ,Calcineurin -- Physiological aspects ,Calcineurin -- Genetic aspects ,Calcineurin -- Research ,Biological sciences - Abstract
The role of calcineurin (Cn) in skeletal muscle fiber-type expression has been a subject of great interest because of reports indicating that it controls the slow muscle phenotype. To delineate the role of Cn in phenotype remodeling, particularly its role in driving expression of the type I myosin heavy chain (MHC) gene, we used a novel strategy whereby a profound transition from fast to slow fiber type is induced and examined in the absence and presence of cyclosporin A (CsA), a Cn inhibitor. To induce the fast-to-slow transition, we first subjected rats to 7 days of hindlimb suspension (HS) + thyroid hormone [triiodothyronine ([T.sub.3])] to suppress nearly all expression of type I MHC mRNA in the soleus muscle. HS + [T.sub.3] was then withdrawn, and rats resumed normal ambulation and thyroid state, during which vehicle or CsA (30 mg x [kg.sup.-1] x [day.sup.-1]) was administered for 7 or 14 days. The findings demonstrate that, despite significant inhibition of Cn, pre-mRNA, mRNA, and protein abundance of type I MHC increased markedly during reloading relative to HS + [T.sub.3] (P < 0.05). Type I MHC expression was, however, attenuated by CsA compared with vehicle treatment. In addition, type IIa and IIx MHC pre-mRNA, mRNA, and relative protein levels were increased in Cn-treated compared with vehicle-treated rats. These findings indicate that Cn has a modulatory role in MHC transcription, rather than a role as a primary regulator of slow MHC gene expression. hindlimb suspension; cyclosporin A; antisense RNA; myosin heavy chain SDS-PAGE; thyroid hormone doi: 10.1152/ajpregu.00349.2009
- Published
- 2009
6. Overview of Methionine Adenosyltransferase 2A (MAT2A) as an Anticancer Target: Structure, Function, and Inhibitors.
- Author
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Li, Chunzheng, Gui, Gang, Zhang, Li, Qin, Anqi, Zhou, Chen, and Zha, Xiaoming
- Published
- 2022
- Full Text
- View/download PDF
7. Intergenic bidirectional promoter and cooperative regulation of the IIx and IIb MHC genes in fast skeletal muscle
- Author
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Rinaldi, Chiara, Haddad, Fadia, Bodell, Paul W., Qin, Anqi X., Jiang, Weihua, and Baldwin, Kenneth M.
- Subjects
Genetic regulation -- Physiological aspects ,Genetic regulation -- Research ,Major histocompatibility complex -- Physiological aspects ,Major histocompatibility complex -- Genetic aspects ,Major histocompatibility complex -- Research ,Muscles -- Physiological aspects ,Muscles -- Genetic aspects ,Muscles -- Research ,Biological sciences - Abstract
This study investigated the dynamic regulation of IIx-IIb MHC genes in the fast white medial gastrocnemius (WMG) muscle in response to intermittent resistance exercise training (RE), a model associated with a rapid shift from IIb to IIx expression (11). We investigated the effect of 4 days of RE on the transcriptional activity across the skeletal MHC gene locus in the WMG in female Sprague-Dawley rats. Our results show that RE resulted in significant shifts from lib to IIx observed at both the pre-mRNA and mRNA levels. An antisense RNA (xII NAT) was detected in the intergenic (IG) region between IIx and IIb, extending across the entire IIx gene and into its promoter. The expression of the xII NAT was positively correlated with IIb pre-mRNA (R = +0.8), and negatively correlated with IIx pre-mRNA (R = -0.8). Transcription mapping of the IIx-IIb IG region revealed the generation of sense IIb and xII NATs from a single promoter region. This bidirectional promoter is highly conserved among species and contains several regulatory elements that may be implicated in its regulation. These results suggest that the IIx and the lib genes are physically and functionally linked via the bidirectional promoter. In order for the IIx MHC gene to be regulated, a feedback mechanism from the IG xII NAT is needed. In conclusion, the IG bidirectional promoter generating antisense RNA appears to be essential for the coordinated regulation of the skeletal muscle MHC genes during dynamic pheno-type shifts. gene transcription; pre-mRNA; natural antisense RNA; comparative genomics
- Published
- 2008
8. Intergenic transcription and developmental regulation of cardiac myosin heavy chain genes
- Author
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Haddad, Fadia, Qin, Anqi X., Bodell, Paul W., Jiang, Weihua, Giger, Julia M., and Baldwin, Kenneth M.
- Subjects
Heart muscle -- Chemical properties ,Myosin -- Genetic aspects ,Genetic transcription -- Evaluation ,Genetic regulation -- Evaluation ,Biological sciences - Abstract
Cardiac myosin heavy chain (MHC) gene expression undergoes a rapid transition from [beta]- to [alpha]-MHC during early rodent neonatal development (0-21 days of age). Thyroid hormone (3,5,3'-triiodothyronine, [T.sub.3]) is a major player in this developmental shift; however, the exact mechanism underlying this transition is poorly understood. The goal of this study was to conduct a more thorough analysis of transcriptional activity of the cardiac MHC gene locus during the early postnatal period in the rodent, in order to gain further insight on the regulation of cardiac MHC genes. We analyzed the expression of ct- and [beta]-MHC at protein, mRNA, and pre-mRNA levels at birth and 7, 10, 15, and 21 days after birth in euthyroid and hypothyroid rodents. Using novel technology, we also analyzed RNA expression across the cardiac gene locus, and we discovered that the intergenic (IG) region between the two cardiac genes possesses bidirectional transcriptional activity. This IG transcription results in an antisense RNA product as described previously, which is thought to exert an inhibitory effect on [beta]-MHC gene transcription. On the second half of the IG region, sense transcription occurs, resulting in expression of a sense IG RNA that merges with the [alpha]-MHC pre-mRNA. This sense IG RNA transcription was detected in the [alpha]-MHC gene promoter, approximately -1.8 kb relative to the [alpha]-MHC transcription start site. Both sense and antisense IG RNAs were developmentally regulated and responsive to a hypothyroid state (11, 14). This novel observation provides more complexity to the cooperative regulation of the two genes, suggesting the involvement of epigenetic processes in the regulation of cardiac MHC gene locus. gene transcription; antisense RNA; pre-mRNA; thyroid hormone; reverse transcriptase-polymerase chain reaction; bidirectional promoter; epigenetic regulation; Sprague-Dawley rats
- Published
- 2008
9. IIx myosin heavy chain promoter regulation cannot be characterized in vivo by direct gene transfer
- Author
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Pandorf, Clay E., Haddad, Fadia, Qin, Anqi X., and Baldwin, Kenneth M.
- Subjects
Muscles -- Properties ,Messenger RNA -- Properties ,Polymerase chain reaction -- Observations ,Genetic transcription -- Research ,Physiological research ,Biological sciences - Abstract
In skeletal muscle of the adult mammal IIx is a pivotal myosin heavy chain (MHC) isoform that can be either up- or downregulated depending on both the fiber type of the target muscle and the type of external stimulus imposed. Since little is known about promoter elements of the IIx MHC gene that are important for its transcriptional regulation in vivo, the main goal of this study was to characterize IIx MHC promoter activity and identify potential regulatory elements on the IIx MHC promoter. A direct gene transfer approach was used, and this approach involved transfection of promoter-reporter constructs into intact rat soleus and plantaris muscle under control and denervated conditions, as well as hindlimb suspension (i.e., models to upregulate IIx MHC transcription). Fast-twitch (plantaris) muscle fibers were confirmed to have significantly greater IIx MHC transcriptional products (pre-mRNA and mRNA) than slow-twitch (soleus) muscle fibers. However, promoter sequences corresponding to -2671 to + 1720, -1000 to +392, and -605/+392 relative to the IIx MHC transcription start site, plus an additional construct ligated to a putative embryonic MHC enhancer, failed to produce a fiber type-specific response that is characteristic of the endogenous IIx MHC promoter. Furthermore, the activity of these promoter constructs did not demonstrate the expected response to denervation or hindlimb suspension (i.e., marked upregulation), despite normal uptake and activity of a coinjected [alpha]-actin reference promoter. On the basis of these findings with IIx MHC promoter-reporters we conclude that the loss of the native chromatin environment as well as other necessary cis elements may preclude use of the gene transfer approach, thereby suggesting that there are hidden layers of regulation for the IIx MHC gene. soleus; plantaris; reverse transcription-polymerase chain reaction: pre-messenger RNA; messenger RNA; skeletal muscle
- Published
- 2007
10. Activity of the [beta]-myosin heavy chain antisense promoter responds to diabetes and hypothyroidism
- Author
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Giger, Julia, Qin, Anqi X., Bodell, Paul W., Baldwin, Kenneth M., and Haddad, Fadia
- Subjects
Messenger RNA -- Analysis ,Cell receptors -- Physiological aspects ,Myosin -- Analysis ,Hypothyroidism -- Diagnosis ,Diabetes -- Diagnosis ,Biological sciences - Abstract
Two genes encoding cardiac myosin heavy chain (MHC) isoforms, [beta] and [alpha], are arranged in tandem 4.5 kb apart. We examined pre-mRNA and mature mRNA levels of [beta] and ct genes in control, diabetic (streptozotocin), hypothyroid (propylthiouracil), and hyperthyroid rat hearts and analyzed the naturally occurring antisense (AS) [beta] RNA species that starts in the middle of the 4.5-kb intergenic region and extends upstream to the [beta]-gene promoter. The [beta] and [alpha] genes are expressed antithetically in control, diabetic, hypothyroid, and hyperthyroid hearts. Expression of AS [beta]-RNA was positively correlated with [alpha]-mRNA and negatively correlated with sense [beta] mRNA. These results support the novel idea of common promoter-regulatory elements situated in the intergenic region that likely control transcription of both sense [alpha] and AS [beta] genes and that AS [beta] transcription negatively regulates [beta]-MHC gene expression. To test whether an intergenic promoter drives transcription of AS [beta] RNA, a 1340-bp sequence of the intergenic region was inserted into a luciferase plasmid in the 3'-to-5' AS direction and was injected into rat ventricle. This promoter was activated in control heart and decreased greatly in response to propylthiouracil and streptozotocin and increased in hyperthyroid rats, similar in pattern to the endogenous AS [beta] RNA. When a putative retinoic acid receptor (RAR) site (a known thyroid hormone receptor cofactor) in this promoter was mutated, the reporter activity was almost abolished in control, propylthiouracil, and streptozotocin hearts. We conclude that there is an intergenic promoter that is active in the AS direction and that the putative RAR element is a vital regulatory site. mRNA; hyperthyroidism; in vivo gene injection; retinoic acid receptor; peroxisome proliferator-activated receptor doi: 10.1152/ajpheart.01224.2006.
- Published
- 2007
11. A Regulatory Role for Antisense RNA in Myosin Gene Expression during Differentiation of Rat Skeletal Muscle: 1738: Board #271 June 1 2:00 PM - 3:30 PM
- Author
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Pandorf, Clay E., Haddad, Fadia, Qin, Anqi X., Jiang, Weihua, Bodell, Paul W., and Baldwin, Kenneth M.
- Published
- 2011
- Full Text
- View/download PDF
12. Is Artificial Gravity An Effective Countermeasure To Microgravity: 2258: Board #146 May 28 3:30 PM - 5:00 PM
- Author
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Caiozzo, Vincent, Blank, Jason, Baker, Mike, Kreitenberg, Art, Qin, Anqi, Haddad, Fadia, Adams, Greg, and Baldwin, Kenneth M.
- Published
- 2009
- Full Text
- View/download PDF
13. Function Of Natural Antisense RNA In Coordinating Myosin Heavy Chain Gene Switching In Skeletal Muscle: 1272 Board #127 2:00 PM - 3:30 PM
- Author
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Pandorf, Clay E., Haddad, Faddia, Roy, Roland R., Qin, Anqi X., Edgerton, V. Reggie, and Baldwin, Kenneth M.
- Published
- 2005
14. Potential pitfalls in the accuracy of analysis of natural sense-antisense RNA pairs by reverse transcription-PCR
- Author
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Guo Hongyan, Giger Julie M, Qin Anqi X, Haddad Fadia, and Baldwin Kenneth M
- Subjects
Biotechnology ,TP248.13-248.65 - Abstract
Abstract Background The ability to accurately measure patterns of gene expression is essential in studying gene function. The reverse transcription polymerase chain reaction (RT-PCR) has become the method of choice for the detection and measurement of RNA expression patterns in both cells and small quantities of tissue. Our previous results show that there is a significant production of primer-independent cDNA synthesis using a popular RNase H- RT enzyme. A PCR product was amplified from RT reactions that were carried out without addition of RT-primer. This finding jeopardizes the accuracy of RT-PCR when analyzing RNA that is expressed in both orientations. Current literature findings suggest that naturally occurring antisense expression is widespread in the mammalian transcriptome and consists of both coding and non-coding regulatory RNA. The primary purpose of this present study was to investigate the occurrence of primer-independent cDNA synthesis and how it may influence the accuracy of detection of sense-antisense RNA pairs. Results Our findings on cellular RNA and in vitro synthesized RNA suggest that these products are likely the results of RNA self-priming to generate random cDNA products, which contributes to the loss of strand specificity. The use of RNase H+ RT enzyme and carrying the RT reaction at high temperature (50°C) greatly improved the strand specificity of the RT-PCR detection. Conclusion While RT PCR is a basic method used for the detection and quantification of RNA expression in cells, primer-independent cDNA synthesis can interfere with RT specificity, and may lead to misinterpretation of the results, especially when both sense and antisense RNA are expressed. For accurate interpretation of the results, it is essential to carry out the appropriate negative controls.
- Published
- 2007
- Full Text
- View/download PDF
15. Estimation of PM2.5 mortality burden in China with new exposure estimation and local concentration-response function.
- Author
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Li, Jin, Liu, Huan, Lv, Zhaofeng, Zhao, Ruzhang, Deng, Fanyuan, Wang, Chufan, Qin, Anqi, and Yang, Xiaofan
- Subjects
PARTICULATE matter ,LAND use ,REGRESSION analysis ,AIR pollution ,PHOTOCHEMICAL oxidants - Abstract
Abstract The estimation of PM 2.5 -related mortality is becoming increasingly important. The accuracy of results is largely dependent on the selection of methods for PM 2.5 exposure assessment and Concentration-Response (C-R) function. In this study, PM 2.5 observed data from the China National Environmental Monitoring Center, satellite-derived estimation, widely collected geographic and socioeconomic information variables were applied to develop a national satellite-based Land Use Regression model and evaluate PM 2.5 exposure concentrations within 2013–2015 with the resolution of 1 km × 1 km. Population weighted concentration declined from 72.52 μg/m
3 in 2013 to 57.18 μg/m3 in 2015. C-R function is another important section of health effect assessment, but most previous studies used the Integrated Exposure Regression (IER) function which may currently underestimate the excess relative risk of exceeding the exposure range in China. A new Shape Constrained Health Impact Function (SCHIF) method, which was developed from a national cohort of 189,793 Chinese men, was adopted to estimate the PM 2.5 -related premature deaths in China. Results showed that 2.19 million (2013), 1.94 million (2014), 1.65 million (2015) premature deaths were attributed to PM 2.5 long-term exposure, different from previous understanding around 1.1–1.7 million. The top three provinces of the highest premature deaths were Henan, Shandong, Sichuan, while the least ones were Tibet, Hainan, Qinghai. The proportions of premature deaths caused by specific diseases were 53.2% for stroke, 20.5% for ischemic heart disease, 16.8% for chronic obstructive pulmonary disease and 9.5% for lung cancer. IER function was also used to calculate PM 2.5 -related premature deaths with the same exposed level used in SCHIF method, and the comparison of results indicated that IER had made a much lower estimation with less annual amounts around 0.15–0.5 million premature deaths within 2013–2015. Graphical abstract Image 1 Highlights • Developing LUR model for PM 2.5 combined satellite and surface observation. • The spatial resolution of our study is 1 km × 1 km, more elaborate than previous studies. • Updating PM 2.5 -related premature deaths using local concentration–response function. • Our estimation of premature deaths shows higher results than previous understanding. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
16. Intergenic bidirectional promoter and cooperative regulation of the lIx and IIb MHC genes in fast skeletal muscle.
- Author
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Rinaldi, Chiara, Haddad, Fadia, Bodell, Paul W., Qin, Anqi X., Weihua Jiang, and Baldwin, Kenneth M.
- Subjects
LABORATORY rats ,GENES ,MUSCLES ,EXERCISE ,RNA ,MESSENGER RNA - Abstract
This study investigated the dynamic regulation of lIx-IIb MHC genes in the fast white medial gastrocnemius (WMG) muscle in response to intermittent resistance exercise training (RE), a model associated with a rapid shift from IIb to IIx expression (11). We investigated the effect of 4 days of RE on the transcriptional activity across the skeletal MHC gene locus in the WMG in female Sprague-Dawley rats. Our results show that RE resulted in significant shifts from lIb to lIx observed at both the pre-mRNA and mRNA levels. An antisense RNA (xlI NAT) was detected in the intergenic (10) region between lIx and IIb, extending across the entire lIx gene and into its promoter. The expression of the xlI NAT was positively correlated with lIb pre-mRNA (R = +0.8), and negatively correlated with lIx pre-mRNA (R = -0.8). Transcription mapping of the lIx-lIb 10 region revealed the generation of sense IIb and xlI NATs from a single promoter region. This bidirectional promoter is highly conserved among species and contains several regulatory elements that may be implicated in its regulation. These results suggest that the lIx and the IIb genes are physically and functionally linked via the bidirectional promoter. In order for the lIx MHC gene to be regulated, a feedback mechanism from the 10 xII NAT is needed. In conclusion, the IG bidirectional promoter generating antisense RNA appears to be essential for the coordinated regulation of the skeletal muscle MHC genes during dynamic phenotype shifts. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
17. Activity of the β-myosin heavy chain antisense promoter responds to diabetes and hypothyroidism.
- Author
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Giger, Julia, Qin, Anqi X., Bodell, Paul W., Baldwin, Kenneth M., and Haddad, Fadia
- Subjects
- *
GENES , *MYOSIN , *MESSENGER RNA , *ANTISENSE RNA , *GENETIC transcription , *STREPTOZOTOCIN , *HEART - Abstract
Two genes encoding cardiac myosin heavy chain (MHC) isoforms, β and α, are arranged in tandem 4.5 kb apart. We examined pre-mRNA and mature mRNA levels of β and α genes in control, diabetic (streptozotocin), hypothyroid (pro-pylthiouracil), and hyperthyroid rat hearts and analyzed the naturally occurring antisense (AS) β RNA species that starts in the middle of the 4.5-kb intergenic region and extends upstream to the β-gene promoter. The β and a genes are expressed antithetically in control, diabetic, hypothyroid, and hyperthyroid hearts. Expression of AS β-RNA was positively correlated with α-mRNA and negatively correlated with sense β mRNA. These results support the novel idea of common promoter-regulatory elements situated in the intergenic region that likely control transcription of both sense α and AS β genes and that AS β transcription negatively regulates β-MHC gene expression. To test whether an intergenic promoter drives transcription of AS ′ RNA, a 1340-bp sequence of the intergenic region was inserted into a luciferase plasmid in the 3′-to-5′ AS direction and was injected into rat ventricle. This promoter was activated in control heart and decreased greatly in response to propylthiouracil and streptozotocin and increased in hyperthyroid rats, similar in pattern to the endogenous AS β RNA. When a putative retinoic acid receptor (RAR) site (a known thyroid hormone receptor cofactor) in this promoter was mutated, the reporter activity was almost abolished in control, propylthiouracil, and streptozotocin hearts. We conclude that there is an intergenic promoter that is active in the AS direction and that the putative RAR element is a vital regulatory site. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
18. Potential pitfalls in the accuracy of analysis of natural sense-antisense RNA pairs by reverse transcription-PCR.
- Author
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Haddad, Fadia, Qin, Anqi X, Giger, Julie M, Guo, Hongyan, and Baldwin, Kenneth M
- Subjects
- *
POLYMERASE chain reaction , *POLYMERIZATION , *GENE amplification , *ENZYMES , *RNA - Abstract
Background: The ability to accurately measure patterns of gene expression is essential in studying gene function. The reverse transcription polymerase chain reaction (RT-PCR) has become the method of choice for the detection and measurement of RNA expression patterns in both cells and small quantities of tissue. Our previous results show that there is a significant production of primerindependent cDNA synthesis using a popular RNase H- RT enzyme. A PCR product was amplified from RT reactions that were carried out without addition of RT-primer. This finding jeopardizes the accuracy of RT-PCR when analyzing RNA that is expressed in both orientations. Current literature findings suggest that naturally occurring antisense expression is widespread in the mammalian transcriptome and consists of both coding and non-coding regulatory RNA. The primary purpose of this present study was to investigate the occurrence of primer-independent cDNA synthesis and how it may influence the accuracy of detection of sense-antisense RNA pairs. Results: Our findings on cellular RNA and in vitro synthesized RNA suggest that these products are likely the results of RNA self-priming to generate random cDNA products, which contributes to the loss of strand specificity. The use of RNase H+ RT enzyme and carrying the RT reaction at high temperature (50°C) greatly improved the strand specificity of the RT-PCR detection. Conclusion: While RT PCR is a basic method used for the detection and quantification of RNA expression in cells, primer-independent cDNA synthesis can interfere with RT specificity, and may lead to misinterpretation of the results, especially when both sense and antisense RNA are expressed. For accurate interpretation of the results, it is essential to carry out the appropriate negative controls. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
19. Effect of unloading on type I myosin heavy chain gene regulation in rat soleus muscle.
- Author
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Giger, Julia M., Haddad, Fadia, Qin, Anqi X., Ming Zeng, and Baldwin, Kenneth M.
- Subjects
MUSCLE proteins ,GENETIC regulation ,GENETIC transformation ,MESSENGER RNA ,MYOSIN ,GENETIC recombination ,RNA ,LABORATORY rats - Abstract
Slow-twitch soleus, a weight-bearing hindlimb muscle, predominantly expresses the type l myosin heavy chain (MHC) isoform. However, under unloading conditions, a transition in MHC expression occurs from slow type I toward the fast-type isoforms. Transcriptional processes are believed to be involved in this adaptation. To test the hypothesis that the downregulation of MHC
1 in soleus muscle following unloading is controlled through cis element(s) in the proximal region of the promoter, the MHC1 promoter was injected into soleus muscles of control rats and those subjected to 7 days of hindlimb suspension. Mutation analyses of six putative regulatory elements within the -408-bp region demonstrated that three elements, an A/T-rich, the proximal muscle-type CAT (βe3), and an E-box (-63 bp), play an important role in the basal level of MHC1 gene activity in the control soleus and function as unloading- responsive elements. Gel mobility shift assays revealed a diminished level of complex formation of the βe3 and E-box probes with nuclear extract from hindlimb suspension soleus compared with control soleus. Supershift assays indicated that transcriptional enhancer factor 1 and myogenin factors bind the βe3 and E-box elements, respectively, in the control soleus. Western blots showed that the relative concentrations of the transcriptional enhancer factor 1 and myogenin factors were significantly attenuated in the unloaded soleus compared with the control muscle. We conclude that the downregulation of MHC1 in response to unloading is due, in part, to a significant decrease in the concentration of these transcription factors available for binding the positive regulatory elements. [ABSTRACT FROM AUTHOR]- Published
- 2005
- Full Text
- View/download PDF
20. Effect of cyclosporin A treatment on the in vivo regulation of type I MHC gene expression.
- Author
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Giger, Julia M., Haddad, Fadia, Qin, Anqi X., and Balwdin, Kenneth M.
- Subjects
CYCLOSPORINE ,MYOSIN ,GENE expression ,GENETIC mutation ,T cells ,MESSENGER RNA ,PROMOTERS (Genetics) - Abstract
Rat soleus muscle consists predominantly of slow type I fibers. We have shown previously through deletion analysis that the highest level of reporter activity that we measure when injecting type I myosin heavy chain (MHC) promoter (MHC
1 )-linked luciferase plasmid into soleus muscles depends on the presence of a 550-bp upstream enhancer (3,450–2,900) region of the promoter. Because the calcineurin-nuclear factor of activated T cells (NFAT) pathway has been implicated in the regulation of the slow muscle gene program, particularly the MHC1 isoform, and the MHC1 promoter contains several putative NFAT sites, we examined via deletion and mutation analyses whether this pathway is involved in the regulation of promoter activity in soleus. Nine days of treatment with the calcineurin inhibitor cyclosporin A (CsA) caused a significant decrease in activity of the −3,500- and −3,450-bp promoters compared with vehicle-treated rats. Truncation of the promoter to −2,900 bp or smaller reduced the activity and also eliminated the CsA responsiveness, thus implying that the enhancer region is required for CsA responsiveness. Surprisingly, mutating the two NFAT elements within the enhancer region had no obvious effect on promoter activity. CsA treatment resulted in an increase in the mRNA levels of fast-type IIa and IIx MHC isoforms, but RT-PCR analysis of MHC1 pre-mRNA and mature mRNA expression in soleus muscles revealed no differences between vehicle- and CsA-treated rats. Although CsA affects the activity of the MHC1 promoter, it appears that its effect is not through direct binding of NFAT to sites on the promoter. [ABSTRACT FROM AUTHOR]- Published
- 2004
- Full Text
- View/download PDF
21. Functional overload increases β-MHC promoter activity in rodent fast muscle via the proximal MCAT (βe3) site.
- Author
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GIGER, JULIA M., HADDAD, FADIA, QIN, ANQI X., and BALDWIN, KENNETH M.
- Abstract
Functional overload (OL) of the rat plantaris muscle by the removal of synergistic muscles induces a shift in the myosin heavy chain (MHC) isoform expression profile from the fast isoforms toward the slow type I, or, β-MHC isoform. Different length rat β-MHC promoters were linked to a firefly luciferase reporter gene and injected in control and OL plantaris muscles. Reporter activities of -3,500, -914, -408, and -215 bp promoters increased in response to 1 wk of OL. The smallest -171 bp promoter was not responsive to OL. Mutation analyses of putative regulatory elements within the -171 and -408 bp region were performed. The -408 bp promoters containing mutations of the βe1, distal muscle CAT (MCAT; βe2), CACC, or A/T-rich (GATA), were still responsive to OL. Only the proximal MCAT (βe3) mutation abolished the OL response. Gel mobility shift assays revealed a significantly higher level of complex formation of the βe3 probe with nuclear protein from OL plantaris compared with control plantaris. These results suggest that the βe3 site functions as a putative OL-responsive element in the rat β-MHC gene promoter. [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
22. Thyroid receptor plasticity in striated muscle types: Effects of altered thyroid state.
- Author
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Haddad, Fadia, Qin, Anqi X., McCue, Samuel A., and Baldwin, Kenneth M.
- Subjects
- *
NUCLEAR receptors (Biochemistry) , *MYOSIN - Abstract
Highlights a study which investigated the maximum binding capacity and dissociation constant of the nuclear thyroid receptor (TR). Information on the TR isoform mRNA expression in rodent cardiac; Details on the slow-twitch type I myosin heavy-chain expression; Methodology used to conduct the study; Results of the study.
- Published
- 1998
23. Activity of the IIx myosin heavy chain promoter cannot be characterized with gene transfer in vivo.
- Author
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Pandorf, Clay E., Haddad, Fadia, Qin, Anqi X., and Baldwin, Kenneth M.
- Subjects
MYOSIN ,GENETIC regulation ,GENETIC transformation ,MUSCLES ,MESSENGER RNA ,LABORATORY rats - Abstract
In the adult mammal the IIx is a pivotal myosin heavy chain (MHC) isoform that can be either up- or down- regulated depending on both the target muscle and the type of stimulus applied. Since little is known about promoter elements of the IIx MHC gene that are important for its transcriptional regulation in vivo, we characterized the regulatory elements of the IIx promoter using a gene transfer approach involving injected promoter-reporter constructs into intact rat soleus and plantaris muscle under control and denervated conditions (a model to upregulate type IIx transcription). The fast (plantaris) muscle fibers were confirmed to have significantly greater IIx transcriptional products (pre-mRNA and mRNA) than slow (soleus) muscle fibers. However, promoter sequences corresponding to -1000 to +392 and -2671 to +1720 relative to the IIx transcription start site, plus an additional construct ligated to a putative embryonic MHC enhancer, failed to produce a fiber type specific response that reflected the activity of the endogenous IIx promoter. Further, the activity of these promoter constructs did not demonstrate the expected response to denervation (i.e. marked upregulation), despite normal uptake and activity of a co-injected α-actin reference promoter. Other MHC promoters that have been examined (e.g. type I and IIb) are apparently regulated in accordance with classical models of gene regulation that can be delineated with the gene transfer approach. However, based on these findings with the IIx promoter we conclude that the loss of both the native chromatin environment as well as its proper genomic positioning may preclude use of this approach, thereby suggesting that there are hidden layers of regulation for the IIx MHC gene. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
24. A combination of bioinformatics analysis and rational design strategies to enhance keratinase thermostability for efficient biodegradation of feathers.
- Author
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Su, Chang, Gong, Jin-Song, Qin, Anqi, Li, Heng, Li, Hui, Qin, Jiufu, Qian, Jian-Ying, Xu, Zheng-Hong, and Shi, Jin-Song
- Published
- 2022
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25. Role of Antisense RNA in Coordinating Cardiac Myosin Heavy Chain Gene Switching.
- Author
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Haddad, Fadia, Bodell, Paul W., Qin, Anqi X., Giger, Julia M., and Baldwin, Kenneth M.
- Subjects
- *
ANTISENSE DNA , *MYOSIN , *MYOCARDIUM , *BIOCHEMISTRY - Abstract
Presents a study on the expression of an antisense beta myosin heavy chain (MHC) RNA in the normal rodent myocardium. Pattern of expression of the antisense beta-MHC RNA under altered thyroid state and in diabetes; Origin of the antisense transcript; Transcriptional activity of the beta-alpha MHC intergenic DNA.
- Published
- 2003
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26. Dynamics of Myosin Heavy Chain Gene Regulation in Slow Skeletal Muscle: ROLE OF NATURAL ANTISENSE RNA.
- Author
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Pandorf, Clay E., Haddad, Fadia, Roy, Roland R., Qin, Anqi X., Edgerton, V. Reggie, and Baldwin, Kenneth M.
- Subjects
- *
MYOSIN antibodies , *GENE expression , *MUSCULOSKELETAL system , *MESSENGER RNA , *ANTISENSE DNA , *CHROMOSOME analysis - Abstract
The evolutionarily conserved order of the skeletal muscle myosin heavy chain (MHC) genes and their close tandem proximity on the same chromosome are intriguing and may be important for their coordinated regulation. We investigated type II MHC gene regulation in slow-type muscle fibers undergoing a slow to fast MHC transformation in response to inactivity, 7 days after spinal cord isolation (SI) in rats. We examined the transcriptional products of both the sense and antisense strands across the IIa-IIx-IIb MHC gene locus. A strand-specific reverse transcription (RT)-PCR approach was utilized to study the expression of the mRNA, the primary transcript (pre-mRNA), the antisense RNA overlapping the MHC genes, and both the intergenic sense and antisense RNAs. Results showed that the mRNA and pre-mRNA of each MHC had a similar response to SI, suggesting regulation of these genes at the transcriptional level. In addition, we detected previously unknown antisense strand transcription that produced natural antisense transcripts (NATs). RT-PCR mapping of the RNA products revealed that the antisense activity resulted in the formation of three major products: aII, xII, and bII NATs (antisense products of the IIa, IIx, and IIb genes, respectively). The aII NAT begins in the IIa-IIx intergenic region in close proximity to the IIx promoter, extends across the 27-kb IIa MHC gene, and continues to the ha MHC gene promoter. The expression of the aII NAT was significantly up-regulated in muscles after SI, was negatively correlated with IIa MHC gene expression, and was positively correlated with IIx MHC gene expression. The exact role of the aII NAT is not clear; however, it is consistent with the inhibition of ha MHC gene transcription. In conclusion, NATs may mediate cross-talk between adjacent genes, which may be essential to the coordinated regulation of the skeletal muscle MHC genes during dynamic phenotype shifts. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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27. A pancancer analysis of histone deacetylase 3 in human tumors.
- Author
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Chen H, Xu F, Qin A, Guo S, Zhang G, Yu B, and Zheng Q
- Abstract
Background: Histone deacetylase 3 ( HDAC3 ) is known to be an important role in various kinds of cancer, but its effect has not been examined on the pancancer level. Thus, a systematic pancancer analysis was conducted to explore its potential role in pancancer diagnosis, prognosis, and immune correlation research., Methods: We used a series of databases including The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx) Project, The University of Alabama at Birmingham Cancer data analysis portal (UALCAN), Tumor Immune Estimation Resource (TIMER), and Search Tool for the Retrieval of Interacting Genes/Proteins (STRING), among others, to analyze the relationship between the expression of HDAC3 and the diagnosis and prognosis of cancer, the tumor microenvironment (TME), immune infiltration, tumor mutational burden (TMB), microsatellite instability (MSI), mismatch repair (MMR) system using various bioinformatics methods. Downstream pathways of HDAC3 were identified by gene set enrichment analysis (GSEA). Furthermore, the protein expression of HDAC3 in tumor tissues and normal tissues of 17 patients with gliomas was analyzed via western blotting., Results: The expression of HDAC3 changed in most types of tumors, which was closely related to most tumor diagnoses and negatively related to some patients' overall survival (OS) and recurrence-free survival (RFS). The pan-cancer analysis demonstrated that it was tightly correlated to DNA methylation and RNA methylation modifications and associated with TMB and MSI. The expression level of HDAC3 was positively correlated with many immune checkpoint molecules and regulators and positively associated with the infiltration levels of immune cells in the TME in most tumor types. Furthermore, enrichment analysis revealed that transcriptional misregulation in cancer and RNA splicing functions were involved in the functional mechanism of HDAC3 -related genes. Experimental research showed that the protein expression of HDAC3 was elevated in tumor tissues of patients with glioma., Conclusions: Through our comprehensive bioinformatics analysis, we evaluated the role of HDAC3 in pancancer, and our findings suggest that it may be an indicator for some cancer diagnoses and influence immune balance., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tcr.amegroups.com/article/view/10.21037/tcr-23-1228/coif). The authors have no conflicts of interest to declare., (2024 Translational Cancer Research. All rights reserved.)
- Published
- 2024
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28. Defect Engineered Microcrystalline Cellulose for Enhanced Cocatalyst-Free Piezo-Catalytic H 2 Production.
- Author
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Zhang K, Sun X, Hu H, Yan G, Qin A, Ma Y, Huang H, and Ma T
- Abstract
Mechanical energy driven piezocatalytic hydrogen (H
2 ) production is a promising way to solve the energy crisis . But limited by the slow separation and transfer efficiency of piezoelectric charges generated on the surface of piezocatalysts , the piezocatalytic performance is still not satisfactory. Here, defect engineering is first used to optimize the piezocatalytic performance of microcrystalline cellulose (MCC). The piezocatalytic H2 production rate of MCC with the optimal defect concentration can reach up to 84.47 µmol g-1 h-1 under ultrasonic vibration without any co-catalyst, which is ≈3.74 times higher than that of the pure MCC (22.65 µmol g-1 h-1 ). The enhanced H2 production rate by piezoelectric catalysis is mainly due to the introduction of defect engineering on MCC, which disorders the symmetry of MCC crystal structure, improves the electrical conductivity of the material, and accelerates the separation and transfer efficiency of piezoelectric charges. Moreover, the piezocatalytic H2 production rate of MCC with the optimal defect concentration can still reach up to 93.61 µmol g-1 h-1 in natural seawater, showingits commendable practicability. This study presents a novel view for designing marvelous-performance biomass piezocatalysts through defect engineering, which can efficiently convert mechanical energy into chemical energy ., (© 2023 The Authors. Small published by Wiley-VCH GmbH.)- Published
- 2023
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29. Estimation of PM 2.5 mortality burden in China with new exposure estimation and local concentration-response function.
- Author
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Li J, Liu H, Lv Z, Zhao R, Deng F, Wang C, Qin A, and Yang X
- Subjects
- Air Pollutants toxicity, Air Pollution analysis, China epidemiology, Cohort Studies, Environmental Monitoring, Humans, Lung Neoplasms chemically induced, Male, Mortality, Premature, Myocardial Ischemia chemically induced, Particulate Matter toxicity, Pulmonary Disease, Chronic Obstructive chemically induced, Stroke chemically induced, Tibet, Air Pollutants analysis, Environmental Exposure adverse effects, Lung Neoplasms mortality, Myocardial Ischemia mortality, Particulate Matter analysis, Pulmonary Disease, Chronic Obstructive mortality, Stroke mortality
- Abstract
The estimation of PM
2.5 -related mortality is becoming increasingly important. The accuracy of results is largely dependent on the selection of methods for PM2.5 exposure assessment and Concentration-Response (C-R) function. In this study, PM2.5 observed data from the China National Environmental Monitoring Center, satellite-derived estimation, widely collected geographic and socioeconomic information variables were applied to develop a national satellite-based Land Use Regression model and evaluate PM2.5 exposure concentrations within 2013-2015 with the resolution of 1 km × 1 km. Population weighted concentration declined from 72.52 μg/m3 in 2013 to 57.18 μg/m3 in 2015. C-R function is another important section of health effect assessment, but most previous studies used the Integrated Exposure Regression (IER) function which may currently underestimate the excess relative risk of exceeding the exposure range in China. A new Shape Constrained Health Impact Function (SCHIF) method, which was developed from a national cohort of 189,793 Chinese men, was adopted to estimate the PM2.5 -related premature deaths in China. Results showed that 2.19 million (2013), 1.94 million (2014), 1.65 million (2015) premature deaths were attributed to PM2.5 long-term exposure, different from previous understanding around 1.1-1.7 million. The top three provinces of the highest premature deaths were Henan, Shandong, Sichuan, while the least ones were Tibet, Hainan, Qinghai. The proportions of premature deaths caused by specific diseases were 53.2% for stroke, 20.5% for ischemic heart disease, 16.8% for chronic obstructive pulmonary disease and 9.5% for lung cancer. IER function was also used to calculate PM2.5 -related premature deaths with the same exposed level used in SCHIF method, and the comparison of results indicated that IER had made a much lower estimation with less annual amounts around 0.15-0.5 million premature deaths within 2013-2015., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2018
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30. Regulation of an antisense RNA with the transition of neonatal to IIb myosin heavy chain during postnatal development and hypothyroidism in rat skeletal muscle.
- Author
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Pandorf CE, Jiang W, Qin AX, Bodell PW, Baldwin KM, and Haddad F
- Subjects
- Animals, Female, Hypothyroidism chemically induced, Muscle, Skeletal metabolism, Propylthiouracil adverse effects, RNA, Antisense genetics, Rats, Transcription, Genetic, Gene Expression Regulation, Developmental, Hypothyroidism metabolism, Muscle, Skeletal growth & development, Myosin Heavy Chains genetics, Nonmuscle Myosin Type IIB genetics, RNA, Antisense metabolism
- Abstract
Postnatal development of fast skeletal muscle is characterized by a transition in expression of myosin heavy chain (MHC) isoforms, from primarily neonatal MHC at birth to primarily IIb MHC in adults, in a tightly coordinated manner. These isoforms are encoded by distinct genes, which are separated by ∼17 kb on rat chromosome 10. The neonatal-to-IIb MHC transition is inhibited by a hypothyroid state. We examined RNA products [mRNA, pre-mRNA, and natural antisense transcript (NAT)] of developmental and adult-expressed MHC genes (embryonic, neonatal, I, IIa, IIx, and IIb) at 2, 10, 20, and 40 days after birth in normal and thyroid-deficient rat neonates treated with propylthiouracil. We found that a long noncoding antisense-oriented RNA transcript, termed bII NAT, is transcribed from a site within the IIb-Neo intergenic region and across most of the IIb MHC gene. NATs have previously been shown to mediate transcriptional repression of sense-oriented counterparts. The bII NAT is transcriptionally regulated during postnatal development and in response to hypothyroidism. Evidence for a regulatory mechanism is suggested by an inverse relationship between IIb MHC and bII NAT in normal and hypothyroid-treated muscle. Neonatal MHC transcription is coordinately expressed with bII NAT. A comparative phylogenetic analysis also suggests that bII NAT-mediated regulation has been a conserved trait of placental mammals for most of the eutherian evolutionary history. The evidence in support of the regulatory model implicates long noncoding antisense RNA as a mechanism to coordinate the transition between neonatal and IIb MHC during postnatal development.
- Published
- 2012
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31. Cloning and sequencing of myosin heavy chain isoform cDNAs in golden-mantled ground squirrels: effects of hibernation on mRNA expression.
- Author
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Rourke BC, Qin A, Haddad F, Baldwin KM, and Caiozzo VJ
- Subjects
- Animals, Base Sequence, Protein Isoforms genetics, Protein Isoforms metabolism, Protein Modification, Translational, Sciuridae metabolism, Cloning, Molecular, DNA, Complementary genetics, Hibernation physiology, Myosin Heavy Chains genetics, Myosin Heavy Chains metabolism, RNA, Messenger metabolism, Sciuridae physiology
- Abstract
The golden-mantled ground squirrel is a small rodent hibernator that demonstrates unusual myosin heavy chain (MHC) isoform plasticity during several months of torpor, punctuated by bouts of rewarming and shivering thermogenesis. We measured MHC mRNA levels to determine whether pretranslational control mechanisms were responsible for differences in MHC2x protein expression, as we previously observed between active and hibernating ground squirrels. We first cloned cDNA using the 3' rapid amplification of cDNA ends (3' RACE) technique and identified three sequences corresponding to MHC1, MHC2x, and MHC2b. A DNA control fragment was developed to be used in conjunction with a coupled RT-PCR reaction to simultaneously measure MHC mRNA levels for each isoform in the skeletal muscle of ground squirrels. MHC mRNA and protein expression were strongly correlated, and type IIx and IIb mRNA levels were significantly different between active and hibernating ground squirrels. Pretranslational control of MHC protein is apparently an important process during hibernation, although the exact stimulus is not known. The techniques presented can be used to obtain MHC cDNA sequences and to measure mRNA expression in many vertebrate groups.
- Published
- 2004
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- View/download PDF
32. Functional overload increases beta-MHC promoter activity in rodent fast muscle via the proximal MCAT (betae3) site.
- Author
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Giger JM, Haddad F, Qin AX, and Baldwin KM
- Subjects
- Animals, Biomechanical Phenomena, Body Weight, Female, Genes, Reporter, Humans, Hypertrophy, Muscle Fibers, Fast-Twitch, Mutagenesis, Site-Directed, Myosin Heavy Chains metabolism, Nuclear Proteins genetics, Nuclear Proteins metabolism, Organ Size, Protein Isoforms, Rats, Rats, Sprague-Dawley, Stress, Mechanical, Muscle, Skeletal physiology, Myosin Heavy Chains genetics, Promoter Regions, Genetic
- Abstract
Functional overload (OL) of the rat plantaris muscle by the removal of synergistic muscles induces a shift in the myosin heavy chain (MHC) isoform expression profile from the fast isoforms toward the slow type I, or, beta-MHC isoform. Different length rat beta-MHC promoters were linked to a firefly luciferase reporter gene and injected in control and OL plantaris muscles. Reporter activities of -3,500, -914, -408, and -215 bp promoters increased in response to 1 wk of OL. The smallest -171 bp promoter was not responsive to OL. Mutation analyses of putative regulatory elements within the -171 and -408 bp region were performed. The -408 bp promoters containing mutations of the betae1, distal muscle CAT (MCAT; betae2), CACC, or A/T-rich (GATA), were still responsive to OL. Only the proximal MCAT (betae3) mutation abolished the OL response. Gel mobility shift assays revealed a significantly higher level of complex formation of the betae3 probe with nuclear protein from OL plantaris compared with control plantaris. These results suggest that the betae3 site functions as a putative OL-responsive element in the rat beta-MHC gene promoter.
- Published
- 2002
- Full Text
- View/download PDF
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