Cell line myoblast

Poly(ethyleneimine)-graft-poly(ethyleneglycol) copolymers Cell line (mouse myoblast cell)... 

There are several limitations in using primary cell lines from patients with mitochondrial disease (e.g., fibroblasts and myoblasts) (Jl). They are not immortal, and usually grow very slowly in regular culture media. Some of the cell lines do not retain a fully physiological, differentiated phenotype in culture. In addition, they tend to lose mutant mtDNA as a result of mitotic segregation (Jl). Most importantly, one cannot rule out the effect of the nuclear background on the phenotypic expression of mitochondrial dysfunction under examination. 

Primary cultures of hepatocyte and tubule cells are prepared by collagenase perfusion and dissociation of the liver or kidney into cell suspensions. Primary rat myocardial cells can be similarly prepared by using trypsin to dissociate the cells. Rhythmic contractions of myocardial cells can be observed in such cultures. Changes in these contractions serve as another end point for the measurement of toxicity.The L6 rat skeletal muscle myoblast cell line has been used to screen compounds for potential muscle irritating and damaging activity. ... 

Most cell lines have lost some or many of the functions characteristic of the differentiated cells from which they were derived. Such relatively undifferentiated cells are poor models for investigating the normal functions of specific cell types. Better in this regard are several more-differentiated cell lines that exhibit many properties of normal nontransformed cells. These lines Include the liver tumor (hepatoma) HepG2 line, which synthesizes most of the serum proteins made by normal liver cells (hepatocytes). Another example consists of cells from a certain cultured fibroblast line, which under certain experimental conditions behave as muscle precursor cells, or myoblasts. These cells can be Induced to fuse to form myotubes, which resemble differentiated multlnucleated muscle cells and synthesize many of the specialized proteins associated with contraction. The results of studies with this cell line have provided valuable information about the differentiation of muscle (Chapter 22). Finally, as discussed previously, the MDCK cell line retains many properties of highly differentiated epithelial cells and forms well-defined epithelial sheets in culture (see Figure 6-6). 

Hawker, J.R. and Granger, H.J. (1994) Nuclear accumulation of exogenous basic fibroblast growth factor in endothelial, fibroblast and myoblast cell lines results in diverse biological responses. In vitro Cell. Dev. Biol. Anim. 30A 653-663. 

Adriamycin is completely without effect on cell proliferation in severely iron-deficient Euglena gracilis and has substantially diminished activity in the Fe-deficient mammalian HL-60 tumor and H9c2 (2-1) heart myoblast cell lines. ° Thus, the availability of cellular iron is necessary for much, if not all, of the cytotoxic effects of Adr in tumor and cardiac cell models. 

Suarez Korsness, M. et al., Apoptotic events induced by yessotoxin in myoblast cell lines from rat and mouse, Toxicol In Vitro, 20, 1077, 2006. 

At nanomolar to micromolar concentrations, yessotoxin has been shown to be toxic to many mammalian cells in culture, including a BE(2)-M17 neuroblastoma cell line [37], a human neuroblastoma cell line [38], HeLa S3 cells [39], rat L6 and mouse BC3H1 skeletal muscle myoblast cell lines [40], P388 mouse leukemia cells [41], 3T3 mouse fibroblasts [42], rat hepatocytes [43], and isolated cerebellar neurons [44]. Yessotoxin did not cause significant mortality in MCE breast cancer cells at nanomolar concentrations, although growth was inhibited [45]. Toxicity to an insect cell line (IPLB-LdFB), derived from a lepidopteran larval fat body, has also been demonstrated [42]. 

In neuroblastoma cell lines [37,38], HeLa S3 cells [39], and myoblasts [40,46] yessotoxin-induced cell death occurred through apoptosis, associated with activation of caspases. hi the case of myoblasts, formation of apoptotic bodies has also been observed [40], and apoptosis may occur through activation of the mitochondrial pathway [46]. In contrast, apoptosis was not the primary cause of death in IPLB-LdFB and 3T3 cells exposed to yessotoxin, and it was suggested that lysosomal damage was the trigger for cell death in these cells [42]. 

Korsnes M.S. et al. Induction of apoptosis by YTX in myoblast cell lines via mitochondrial signalling transduction pathway, Toxicol. In Vitro 20, 1419, 2006. 

As noted earlier, glial cells are a potentially important component of the blood-brain barrier. In our laboratory, we are investigating the uptake of thyroid hormone into cultured cells as models of intracellular uptake in the CNS, and we have included a human glioma cell line in these studies. We have also made a point of looking at the uptake of T as well as T3 since the major source of intracellular T3 in nerve cells is from monodeiodination of T after it is taken into the cell. In the glioma cells as well as in human and mouse neuroblastoma cells and human medulloblastoma cells, specific transport of thyroid hormones can be demonstrated at the plasma membrane. Thus, nervous system cells share this property with hepatocytes, skeletal myoblasts and several other cell types that have been investigated ... 

Differentiatioii of a Myoblast Cell Line and Poly(ADP-Ribosyl)ation... 

We have examined the involvement of poly(ADP-ribose) in myogenesis using a highly myogenic clone (E63) which had been isolated by Kaufman et al. from the L8 rat skeletal muscle cell line [15]. Usually 7 x 10 myoblasts were plated in 100 mm dishes and grown in DME medium containing 10% horse serum. Under these conditions proliferation of myoblasts slows down on day 4, and cultures become confluent with replication being essentially turned off on day 5. Fusion and synthesis of muscle specific proteins start on day 6-7 and increases until day 10-12 when > 90% of cell nuclei are in multinucleated myotubes. 

It may be asked whether the changes in the pattern of poly(ADP-ribose) modified proteins are specific for myoblast differentiation. To answer this question we tested a myoblast clone that had lost its capacity to fuse. This clone (Nf-1) was isolated from the E63 myoblast cell line [1 ]. Cultures of Nf-1 were maintained for 8 days and were analyzed for poly(ADP-ribose) modified proteins. Figure 3 shows that the pattern of modified proteins isolated from the nonfusing variant is similar to that of prefusion E63 myoblasts (5 days). The 116 kD modified protein is present in both cultures, whereas the changes in poly(ADP-ribose) acceptor(s) accompanying differentiation are not observed. We have recently observed that the 116 kD modified protein is also formed if differentiation of E63 myoblasts is inhibited by DMSO or UV light. 

Fig. 3 Relationship between ATP depletion and Pgp expression levels in various cells. The studies included human breast carcinoma cells, MCF-7, and their MDR subline, MCF-7/ADR human oral epidermoid carcinoma cells, KB, and their MDR subline, KBv wUd-type porcine kidney epithelial cells, LLC-PKl, and human MDRl-transfected cells, LLC-MDRl human umbilical vein endothelial cells, HUVEC bovine brain microvessel endothelial cells, BBMEC and murine myoblast cells, C2C12. EC50 values for each of the cell lines were determined from the dose response curves as the concentration of Plutonic P85 inducing a 50% decrease in intracellular ATP following 2 h exposure of the cells to the block copolymer. The drug efflux transport proteins were identified using the im-munoblot technique and normalized to constitutively expressed y3-actin. Plotted using data reported in [33]...

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