scholarly journals Growth and differentiation of cultured satellite cells from callipyge and normal lambs

2000 ◽  
Vol 80 (2) ◽  
pp. 297-302 ◽  
Author(s):  
C. E. Carpenter ◽  
B. T. Rodriguez ◽  
N. E. Cockett

We tested whether the muscle enlargement found in callipyge sheep is linked to increased proliferation, differentiation, and protein accrual of cultured satellite cells. Satellite cells were isolated from the longissimus muscle of three callipyge and three normal lambs. The satellite cells were grown using serum from horse, normal lambs, and callipyge lambs and cultured under conditions that promoted differentiation into myotubes and accumulation of myofibrillar protein. There was no difference in the population doubling times (PDT) or fusion percentages for callipyge and normal satellite cells, but PDT was longer (P < 0.05) for satellite cells grown in callipyge serum (pooled mean PDT = 22 h) than for cells grown in normal sheep serum (PDT = 20 h) or horse serum (PDT = 18 h). The protein:DNA ratios of the cultures increased during 96 h in differentiation media (P < 0.01), but there was no difference in protein:DNA ratios between cells from callipyge and normal lambs. These results suggest that muscle hypertrophy of callipyge sheep is not linked to the inherent capacity of their cultured satellite cells to proliferate, fuse or accrue protein, but hypertrophy may be linked to the influence of serum-born factors on satellite cell proliferation. Key words: Satellite cell, callipyge, sheep, cell culture

2018 ◽  
Vol 314 (5) ◽  
pp. R741-R751 ◽  
Author(s):  
Nobuki Moriya ◽  
Mitsunori Miyazaki

Skeletal muscle mass is determined by the net dynamic balance between protein synthesis and degradation. Although the Akt/mechanistic target of rapamycin (mTOR)-dependent pathway plays an important role in promoting protein synthesis and subsequent skeletal muscle hypertrophy, the precise molecular regulation of mTOR activity by the upstream protein kinase Akt is largely unknown. In addition, the activation of satellite cells has been indicated as a key regulator of muscle mass. However, the requirement of satellite cells for load-induced skeletal muscle hypertrophy is still under intense debate. In this study, female germline Akt1 knockout (KO) mice were used to examine whether Akt1 deficiency attenuates load-induced skeletal muscle hypertrophy through suppressing mTOR-dependent signaling and satellite cell proliferation. Akt1 KO mice showed a blunted hypertrophic response of skeletal muscle, with a diminished rate of satellite cell proliferation following mechanical overload. In contrast, Akt1 deficiency did not affect the load-induced activation of mTOR signaling and the subsequent enhanced rate of protein synthesis in skeletal muscle. These observations suggest that the load-induced activation of mTOR signaling occurs independently of Akt1 regulation and that Akt1 plays a critical role in regulating satellite cell proliferation during load-induced muscle hypertrophy.


2006 ◽  
Vol 31 (6) ◽  
pp. 782-790 ◽  
Author(s):  
Gregory R. Adams

Satellite cells are small, mononuclear cells found in close association with striated skeletal muscles cells (myofibers). These cells appear to function as reserve myoblasts. A critical role for these cells in the process of muscle regeneration following injury has been clearly established. In that role, satellite cells have been shown to proliferate extensively. Some of the progeny of these cells then fuse with each other to form replacement myofibers, whereas others return to quiescence, thereby maintaining this reserve population. In response to injury, activated satellite cells can also fuse with damaged but viable myofibers to promote repair and regeneration. It has also been observed that satellite cells are activated during periods of significantly increased muscle loading and that some of these cells fuse with apparently undamaged myofibers as part of the hypertrophy process. The observation that the inactivation of satellite cell proliferation prevents most of the hypertrophy response to chronic increases in loading has lead to the hypothesis that a limitation to the expansion of myofiber size is imposed by the number of myonuclei present. Recent evidence suggests that a potential limitation to muscle hypertrophy, in the absence of a reserve supply of myonuclei, may be the inability to sustain increases in ribosomes, thereby limiting translational capacity.


2021 ◽  
Vol 17 (8) ◽  
pp. 20210200
Author(s):  
Kevin G. Young ◽  
Timothy R. H. Regnault ◽  
Christopher G. Guglielmo

Migratory birds experience bouts of muscle growth and depletion as they prepare for, and undertake prolonged flight. Our studies of migratory bird muscle physiology in vitro led to the discovery that sanderling ( Calidris alba ) muscle satellite cells proliferate more rapidly than other normal cell lines. Here we determined the proliferation rate of muscle satellite cells isolated from five migratory species (sanderling; ruff, Calidris pugnax ; western sandpiper, Calidris mauri ; yellow-rumped warbler, Setophaga coronata ; Swainson's thrush, Catharus ustulatus ) from two families (shorebirds and songbirds) and with different migratory strategies. Ruff and sanderling satellite cells exhibited rapid proliferation, with population doubling times of 9.3 ± 1.3 and 11.4 ± 2 h, whereas the remaining species' cell doubling times were greater than or equal to 24 h. The results indicate that the rapid proliferation of satellite cells is not associated with total migration distance but may be related to flight bout duration and interact with lifespan.


Open Biology ◽  
2016 ◽  
Vol 6 (9) ◽  
pp. 160211 ◽  
Author(s):  
Bilal Al Jaam ◽  
Katy Heu ◽  
Florian Pennarubia ◽  
Alexandre Segelle ◽  
Laetitia Magnol ◽  
...  

Postnatal skeletal muscle growth results from the activation of satellite cells and/or an increase in protein synthesis. The Notch signalling pathway maintains satellite cells in a quiescent state, and once activated, sustains their proliferation and commitment towards differentiation. In mammals, POFUT1-mediated O -fucosylation regulates the interactions between NOTCH receptors and ligands of the DELTA/JAGGED family, thus initiating the activation of canonical Notch signalling. Here, we analysed the consequences of downregulated expression of the Pofut1 gene on postnatal muscle growth in mutant Pofut1 cax/cax (cax, compact axial skeleton) mice and differentiation of their satellite cell-derived myoblasts (SCDMs). Pofut1 cax/cax mice exhibited muscle hypertrophy, no hyperplasia and a decrease in satellite cell numbers compared with wild-type C3H mice. In agreement with these observations, Pofut1 cax/cax SCDMs differentiated earlier concomitant with reduced Pax7 expression and decrease in PAX7 + /MYOD − progenitor cells. In vitro binding assays showed a reduced interaction of DELTA-LIKE 1 ligand (DLL1) with NOTCH receptors expressed at the cell surface of SCDMs, leading to a decreased Notch signalling as seen by the quantification of cleaved NICD and Notch target genes. These results demonstrated that POFUT1-mediated O- fucosylation of NOTCH receptors regulates myogenic cell differentiation and affects postnatal muscle growth in mice.


1975 ◽  
Vol 34 (03) ◽  
pp. 825-839 ◽  
Author(s):  
Francois M Booyse ◽  
Bonnie J Sedlak ◽  
Max E Rafelson

SummaryArterial endothelial cells were obtained from bovine aortae by mild treatment with collagenase and medium perfusion. These cells were cultured in RPMI-1640 medium containing 15 mM Hepes buffer and 35% fetal calf serum at pH 7.35. Essentially ah (90–95%) the effluent cells were viable and 80% of these cells attached to the substratum within 1 hour. Small patches of attached cells coalesced to form confluent monolayers in 3–5 days. Confluent monolayers of endothelial cells consisted of a homogeneous population of tightly packed, polygonal cells. Selected cultures were serially subcultured (trypsin-EDTA) for 12–14 months (30–35 passages) without any apparent change in morphology or loss of growth characteristics. Primary and three-month old (15 passages) cultures had population doubling times of 32–34 hours and 29–31 hours, respectively. These cells (primary and subcultures) did not require a minimum cell number to become established in culture. Bovine endothelial cells (primary, first, fifth and thirteenth passages) were characterized ultrastructurally by the presence of Weibel-Palade bodies, pinocytotic vesicles and microfilaments and immunologically by the presence of thrombosthenin-like contractile proteins and Factor VIII antigen. The intercellular junctions of post-confluent cultures stained specifically with silver nitrate. From these data, we concluded that identifiable endothelial cells could be obtained from bovine aortae and cultured and maintained for prolonged periods of time.


1991 ◽  
Vol 260 (2) ◽  
pp. C206-C212 ◽  
Author(s):  
P. K. Winchester ◽  
M. E. Davis ◽  
S. E. Alway ◽  
W. J. Gonyea

Satellite cell activity was examined in the stretch-enlarge anterior latissimus dorsi muscle (ALD) of the adult quail. Thirty-seven birds had a weight equal to 10% of their body mass attached to one wing while the contralateral wing served as an intra-animal control. At various time intervals after application of the wing weight (from 1 to 30 days), the birds were injected with tritiated thymidine and killed 1 h later. Stretched muscle length was greater by day 1 and mass by day 3 when compared with the contralateral muscle. Satellite cells actively synthesizing DNA were quantitated in fiber segments of the control and stretched ALD. A minimum of 1,500 muscle nuclei (satellite cell nuclei and myonuclei) were counted in each muscle. Labeling in stretched muscle was expressed by the percent labeled nuclei per total nuclei counted. Satellite cell labeling was initiated by day 1, peaked between days 3 and 7, and was not statistically different from control values at day 30. These results demonstrate that satellite cells are induced to enter the cell cycle in the stretch-enlarged ALD muscle from the adult quail, and the peak of proliferative activity is within the first week of stretch.


2006 ◽  
Vol 290 (4) ◽  
pp. C981-C989 ◽  
Author(s):  
X. D. Wang ◽  
F. Kawano ◽  
Y. Matsuoka ◽  
K. Fukunaga ◽  
M. Terada ◽  
...  

The effects of mechanical unloading and reloading on the properties of rat soleus muscle fibers were investigated in male Wistar Hannover rats. Satellite cells in the fibers of control rats were distributed evenly throughout the fiber length. After 16 days of hindlimb unloading, the number of satellite cells in the central, but not the proximal or distal, region of the fiber was decreased. The number of satellite cells in the central region gradually increased during the 16-day period of reloading. The mean sarcomere length in the central region of the fibers was passively shortened during unloading due to the plantarflexed position at the ankle joint: sarcomere length was maintained at <2.1 μm, which is a critical length for tension development. Myonuclear number and domain size, fiber cross-sectional area, and the total number of mitotically active and quiescent satellite cells of whole muscle fibers were lower than control fibers after 16 days of unloading. These values then returned to control values after 16 days of reloading. These results suggest that satellite cells play an important role in the regulation of muscle fiber properties. The data also indicate that the satellite cell-related regulation of muscle fiber properties is dependent on the level of mechanical loading, which, in turn, is influenced by the mean sarcomere length. However, it is still unclear why the region-specific responses, which were obvious in satellite cells, were not induced in myonuclear number and fiber cross-sectional area.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 104-105
Author(s):  
Shihuan Kuang ◽  
Feng Yue ◽  
Stephanie Oprescu

Abstract Single Cell RNA-sequencing (scRNA-seq) is a powerful technique to deconvolute gene expression of various subset of cells intermingled within a complex tissue, such as the skeletal muscle. We first used scRNA-seq to understand dynamics of cell populations and their gene expression during muscle regeneration in murine limb muscles. This leads to the identification of a subset of satellite cells (the resident stem cells of skeletal muscles) with immune gene signatures in regenerating muscles. Next, we used scRNA-seq to examine gene expression dynamics of satellite cells at various status: quiescence, activation, proliferation, differentiation and self-renewal. This analysis uncovers stage-dependent changes in expression of genes related to lipid metabolism. Further analyses lead to the discovery of previously unappreciated dynamics of lipid droplets in satellite cells; and demonstrate that the abundance of the lipid droplets in newly divided satellite daughter cells is linked to cell fate segregation into differentiation versus self-renewal. Perturbation of lipid droplet dynamics through blocking lipolysis disrupts cell fate homeostasis and impairs muscle regeneration. Finally, we show that lipid metabolism regulates the function of satellite cells through two mechanisms. On one hand, lipid metabolism functions as an energy source through fatty acid oxidation (FAO), and blockage of FAO reduces energy production that is critical for satellite cell function. On the other hand, lipid metabolism generates bioactive molecules that influence signaling transduction and gene expression. In this scenario, lipid metabolism and FAO regulate the intracellular levels of acetyl-coA and selective acetylation of PAX7, a pivotal transcriptional factor underlying function of satellite cells. These results together reveal for the first time a critical role of lipid metabolism and lipid droplet dynamics in muscle satellite cell fate determination and regenerative function; and underscore a potential role of dietary fatty acids in satellite cell-dependent muscle development, growth and regeneration.


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