Regeneration of Cardiomyocytes from Bone Marrow Stem Cells and Application to Cell Transplantation Therapy
Richard K. Burt, Alberto M. Marmont in Stem Cell Therapy for Autoimmune Disease, 2019
Various cardiac contractile protein isoforms are differentially expressed in cardiomyocytes at different developmental stages and in different chambers. At around the time of birth there is a developmental switch in the ventricular muscle of small mammals from expression of β-myosin heavy chain (MHC), which is the predominant fetal form, to expression of a-MHC. There is also a developmental switch from expression of α-skeletal actin, which is the predominant fetal and neonatal form, to that of α-cardiac actin, the predominant adult form. We investigated the contractile protein isoforms of bone marrow-derived CMG cells to characterize their phenotype as cardiomyocytes. Table 1 summarizes the results. Fetal, neonatal, and adult ventricle and atrium were used as controls.14 Expression of both α- and β-MHC was detected in differentiated CMG cells by RT-PCR, but β-MHC expression was overwhelmingly greater than that of α-MHC. CMG cells expressed both α-cardiac and α-skeletal actin, but the α-skeletal actin gene was expressed at markedly higher levels than the α-cardiac actin gene. Interestingly, CMG cells expressed the myosin light chain (MLC)-2v gene, but not the MLC-2a gene. MLC-2v is specifically expressed in ventricular cells, while MLC-2a is specifically expressed in atrial cells. Skeletal muscle cells do not express either a-MHC or MLC-2v. These results indicated that differentiated CMG cells possess the specific phenotype of the fetal ventricular cardiomyocytes.11
Genetics of muscle mass and strength
Adam P. Sharples, James P. Morton, Henning Wackerhage in Molecular Exercise Physiology, 2022
The actinins, abbreviated ACTNs, are actin-binding proteins located in the Z discs of sarcomeres within skeletal muscle. There are two ACTN isoforms of which ACTN2 is expressed in all muscle fibres, whereas ACTN3 is only expressed in fast type II muscle fibres. Initially, an ACTN3 deficiency was found in patients with muscular dystrophies but then a team led by Kathryn North demonstrated that the absence of ACTN3 is common in individuals with no muscle disease and caused by a so-called ACTN3 R577X polymorphism (29). Using PCR and DNA sequencing, they identified a common C→T single nucleotide polymorphism (SNP) in exon 16 of the ACTN3 gene. This one nucleotide difference in the DNA sequence greatly changes the ACTN3 protein because as a consequence, amino acid 577, which is normally an arginine (abbreviated as R), is changed to a stop codon, abbreviated as X. Hence, the polymorphism is abbreviated as ACTN3 R577X.
Nutrigenomics for Sport and Exercise Performance
Peter M. Tiidus, Rebecca E. K. MacPherson, Paul J. LeBlanc, Andrea R. Josse in The Routledge Handbook on Biochemistry of Exercise, 2020
The ACTN3 (rs1815739) gene encodes the alpha-actin 3 protein, which plays a key role in the contraction of fast-twitch or power-type muscle fibres during short bursts of intense activities, such as sprinting or lifting heavy objects (154). Genetic variation in ACTN3 affects the expression of the resulting protein in fast-twitch fibres, and individuals who carry at least one copy of the T variant produce a lower-functioning ACTN3 protein that has been linked to increased risk of muscle damage (52). For example, a recent study showed that experienced endurance athletes with the T variant had higher levels of markers of muscle damage after a competitive marathon (38) compared to individuals with the CC variant. A similar trend was observed in a study where healthy young men performed knee extension exercises, working the quadriceps, in a laboratory setting (39).
Liver transcriptome analysis reveals biological pathways and transcription factors in response to high ammonia exposure
Published in Inhalation Toxicology, 2022
Daojie Li, Shuangzhao Chen, Chun Liu, Baoxing Wei, Xiaoping Li
A previous study showed that ammonia exposure induced apoptosis in chicken livers (Xu et al. 2020). In this study, some core genes (ACTG1, PIK3CA, RB1, TAF1, KAT5, FOS, JUNB, and ATF3) that were related with apoptosis changed their expression after ammonia exposure. ACTG1 is a member of the actin family and the decrease of its expression promoted apoptosis (Zhou et al. 2020; Wu et al. 2021). In our transcriptome data, ACTG1 was a significantly down-regulated gene, indicating that it may be involved in the apoptosis process in pig liver under 80 ppm ammonia exposure. PIK3CA gene encode an important subunit of phosphatidylinositol-3-kinases (PI3Ks), and PI3K pathway is known to be important for apoptosis (Hellwinkel et al. 2008). RB1, TAF1, and KAT5 genes were also reported to play key roles in apoptosis (Indovina et al. 2015; Oh et al. 2017; Humbert et al. 2020). FOS and JUNB encode components of the dimeric transcription factor AP-1 (Rassidakis et al. 2005; Takada et al. 2010). AP-1 is an essential regulator of cell proliferation, inflammation and apoptosis. In addition, transcription factor ATF3, encoded by ATF3 gene, regulates inflammatory response and apoptosis under a stress condition (Jang et al. 2012). In our results, the changed expression of these genes indicated that ammonia may induce apoptosis in pig livers.
Enhancement in the ATP level and antioxidant capacity of Caenorhabditis elegans under continuous exposure to extremely low-frequency electromagnetic field for multiple generations
Published in International Journal of Radiation Biology, 2020
Yahong Wang, Yongyan Sun, Ziyan Zhang, Zhihui Li, Hongying Zhang, Yanyan Liao, Chao Tang, Peng Cai
Adult worms in the C and E groups were collected at 60 h in the F1 and F15 generations, with approximately 20,000, using real-time fluorescent quantitative PCR to detect changes in the ATP synthase (r53.4, hpo-18, atp-5, unc-32, atp-3) and SOD synthase (sod-1, sod-2, sod-3) mRNA levels. The methods were as follows: RNA was extracted using the Trizol method (Invitrogen, CA, USA), a reverse transcription kit (cDNA Synthesis Kit, Ta Ka Ra) was used to reverse transcribe the RNA into cDNA, and finally, the mRNA expression of the gene was detected using a fluorescent quantitative PCR kit (TB Green TM Premix Ex Taq TM II kit). The relative quantification of targeted genes was detected in comparison with the reference gene actin-1. The relative expression of the gene was determined using the 2−△△t method. The experiment was repeated three times, and the primer sequences involved in the experiment are shown in Table 1.
Performance of ImproGene cfDNA blood collection tubes for mutation analysis in cancer patients
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 2022
Shu Zhang, Dongyao Zhou, Siyun Li, Yingming Bai, Bo Huang, Jianhong Han, Mingfei Xu, Sina Wang, Guanhua Deng
Plasma average cfDNA concentration in ImproGene tube at days 0, 3 and 7 were 1.13 ± 0.73 ng/μL, 1.11 ± 0.66 ng/μL and 1.07 ± 0.52 ng/μL respectively (Figure 2(A)). The average concentration on day 3 and day 7 were reduced 0.022 ng/μL and 0.060 ng/μL respectively by compared to day 0 (p = .79 and .51). And that on day 7 was reduced 0.039 ng/μL by compared to day 3 (p = .63). There was no significant increase or decrease of cfDNA concentration in blood stored in ImproGene tubes according to statistical analysis results. Also, the cfDNA had no significant difference in quantity (p = .62, Figure 3(A)) between samples in ImproGene tubes and Streck tubes and had consistent fragment size (Figure 4). β-actin and LINE1 gene were representative of genomic DNA. The Ct value changes of β-actin and LINE1 were within ±1 which means no obvious release of genomic DNA up to 7 days (Figure 2(B,C)). And the artificially added exogenous gene fragment in ImproGene tubes could be preserved for 7 days (Figure 2(D)). The exogenous fragment was stable and intact, and the additive in ImproGene tubes did not interfere with PCR reagent system.
Related Knowledge Centers
- Actin
- Aspartic Acid
- Glutamic Acid
- Leucine
- Methionine
- Sarcomere
- Threonine
- Alpha-Actinin-2
- Serine
- C-Terminus