Stretch overload-induced satellite cell activation in slow tonic muscle from adult and aged Japanese quail

1996 ◽  
Vol 270 (2) ◽  
pp. C578-C584 ◽  
Author(s):  
J. A. Carson ◽  
S. E. Alway

Stretch overload-induced activation of satellite cells in the anterior latissimus dorsi (ALD) muscle was examined in full-grown adult (12 wk old) and aged (90 wk old) Japanese quail. 5'-Bromo-2'-deoxyuridine (BrdU) constant-release pellets (0.22 mg BrdU.g body wt-1.day-1) were implanted subcutaneously before weighting the left wing of each bird. Nuclei that incorporated BrdU were localized by immunohistochemistry after 1 or 2 wk of stretch overload. Total fiber number was quantified by counting all fibers in a histological cross section from the midbelly of the ALD. Aging reduced increases in ALD mass and fiber number during 2 wk of stretch overload. Fiber proliferation in the ALD of aged birds also demonstrated an altered time course. The percentage of BrdU-positive nuclei associated with muscle fibers and the percentage of fibers associated with BrdU-positive nuclei did not differ between age groups. The altered time course of new fiber formation in the ALD of aged birds during 2 wk of stretch overload does not appear to be related to the capability to activate satellite cells.

1991 ◽  
Vol 260 (3) ◽  
pp. C400-C408 ◽  
Author(s):  
S. E. Alway

Stretch-overload has been shown to increase muscle mass in the anterior latissimus dorsi (ALD) of the adult quail by increasing both fiber size and number, but it is not known whether the new muscle fibers or fiber size is maintained after removal of the stretch stimulus. A weight was added to the right wing of 40 adult quail while the left wing in each bird served as an intra-animal control. The weight was removed after 30 days of stretch, and terminal experiments were conducted 0, 30, 60, or 90 days thereafter. Average slow beta-fiber area increased by 53.4 +/- 17.5% (SE) after 30 days of stretch, but it was not different from control area by 30 days poststretch removal. Total fiber number was determined after nitric acid digestion of connective tissue. It increased by 41.3 +/- 2.3% after 30 days of stretch, but it was 28.5 +/- 5.2% greater than control after unweighting for 30- days. Thus, once the overload was removed, fiber number returned to control levels more slowly than fiber mass or volume. The data suggest that mechanisms that downregulate fiber number and fiber size may differ in the ALD of the Japanese quail.


2011 ◽  
Vol 286 (22) ◽  
pp. 19556-19564 ◽  
Author(s):  
Tohru Hosoyama ◽  
Koichi Nishijo ◽  
Suresh I. Prajapati ◽  
Guangheng Li ◽  
Charles Keller

Satellite cells are well known as a postnatal skeletal muscle stem cell reservoir that under injury conditions participate in repair. However, mechanisms controlling satellite cell quiescence and activation are the topic of ongoing inquiry by many laboratories. In this study, we investigated whether loss of the cell cycle regulatory factor, pRb, is associated with the re-entry of quiescent satellite cells into replication and subsequent stem cell expansion. By ablation of Rb1 using a Pax7CreER,Rb1 conditional mouse line, satellite cell number was increased 5-fold over 6 months. Furthermore, myoblasts originating from satellite cells lacking Rb1 were also increased 3-fold over 6 months, while terminal differentiation was greatly diminished. Similarly, Pax7CreER,Rb1 mice exhibited muscle fiber hypotrophy in vivo under steady state conditions as well as a delay of muscle regeneration following cardiotoxin-mediated injury. These results suggest that cell cycle re-entry of quiescent satellite cells is accelerated by lack of Rb1, resulting in the expansion of both satellite cells and their progeny in adolescent muscle. Conversely, that sustained Rb1 loss in the satellite cell lineage causes a deficit of muscle fiber formation. However, we also show that pharmacological inhibition of protein phosphatase 1 activity, which will result in pRb inactivation accelerates satellite cell activation and/or expansion in a transient manner. Together, our results raise the possibility that reversible pRb inactivation in satellite cells and inhibition of protein phosphorylation may provide a new therapeutic tool for muscle atrophy by short term expansion of the muscle stem cells and myoblast pool.


Lupus ◽  
2021 ◽  
pp. 096120332199010
Author(s):  
Vineeta Shobha ◽  
Anu Mohan ◽  
AV Malini ◽  
Puneet Chopra ◽  
Preethi Karunanithi ◽  
...  

Objective Despite the significant advancement in the understanding of the pathophysiology of systemic lupus erythematosus (SLE) variable clinical response to newer therapies remain a major concern, especially for patients with lupus nephritis and neuropsychiatric systemic lupus erythematosus (NPSLE). We performed this study with an objective to comprehensively characterize Indian SLE patients with renal and neuropsychiatric manifestation with respect to their gene signature, cytokine profile and immune cell phenotypes. Methods We characterized 68 Indian SLE subjects with diverse clinical profiles and disease activity and tried to identify differentially expressed genes and enriched pathways. To understand the temporal profile, same patients were followed at 6 and 12-months intervals. Additionally, auto-antibody profile, levels of various chemokines, cytokines and the proportion of different immune cells and their activation status were captured in these subjects. Results Multiple IFN-related pathways were enriched with significant increase in IFN-I gene signature in SLE patients as compared to normal healthy volunteers (NHV). We identified two transcriptionally distinct clusters within the same cohort of SLE patients with differential immune cell activation status, auto-antibody as well as plasma chemokines and cytokines profile. Conclusions Identification of two distinct clusters of patients based on IFN-I signature provided new insights into the heterogeneity of underlying disease pathogenesis of Indian SLE cohort. Importantly, patient within those clusters retain their distinct expression dynamics of IFN-I signature over the time course of one year despite change in disease activity. This study will guide clinicians and researchers while designing future clinical trials on Indian SLE cohort.


2001 ◽  
Vol 86 (07) ◽  
pp. 164-171 ◽  
Author(s):  
Thalia Romani de Wit ◽  
Jan van Mourik

SummaryVon Willebrand factor (VWF) is a multifunctional plasma protein that plays a prominent role in haemostasis. In endothelial cells, processing of its precursor pro-VWF results in the formation of two large polypeptides, mature VWF and a propeptide. These proteins are co-secreted on an equimolar basis but are cleared from the circulation at different rates. VWF levels are frequently elevated in response to vascular disorders. Similarly, propeptide levels are increased under these conditions, although primarily in fulminant vascular disease, such as thrombotic thrombocytopenic purpura and septicemia. In chronic vascular disease, e.g. diabetes or peripheral vascular disease, propeptide levels are much less elevated. The differential response of VWF and propeptide levels to vascular disease could provide a means to assess the extent and time course of endothelial cell activation. After secretion, the propeptide may play a role in modulating cellular adhesion processes. Thus, enhanced propeptide secretion seems not to be of merely diagnostic significance.


1994 ◽  
Vol 14 (8) ◽  
pp. 5523-5532
Author(s):  
D R Stover ◽  
K A Walsh

We describe a potential regulatory mechanism for the transmembrane protein-tyrosine phosphatase CD45. Phosphorylation on both tyrosine and serine residues in vitro results in an activation of CD45 specifically toward one artificial substrate but not another. The activation of these kinases appears to be order dependent, as it is enhanced when phosphorylation of tyrosine precedes that of serine but phosphorylation in the reverse order yields no activation. Any of four protein-tyrosine kinases tested, in combination with the protein-serine/threonine kinase, casein kinase II, was capable of mediating this activation in vitro. The time course of phosphorylation of CD45 in response to T-cell activation is consistent with the possibility that this regulatory mechanism is utilized in vivo.


1993 ◽  
Vol 75 (3) ◽  
pp. 1263-1271 ◽  
Author(s):  
J. Antonio ◽  
W. J. Gonyea

Intermittent stretch of the anterior latissimus dorsi (ALD) muscle produces fiber hypertrophy without fiber hyperplasia (J. Appl. Physiol. 74: 1893–1898, 1993). This study was undertaken to determine if a progressive increase in load and duration of stretch would induce extremely large muscle fiber areas or if the fibers would reach a critical size before the onset of fiber hyperplasia. Weights ranging from 10 to 35% of the bird's mass were attached to the right wing of 26 adult quail while the left wing served as the intra-animal control. The stretch protocol was as follows: day 1 (10% wt), days 2 and 3 (rest), day 4 (15% wt), days 5–7 (rest), day 8 (20% wt), days 9 and 10 (rest), days 11–14 (25% wt), days 15 and 16 (rest), and days 17–38 (35% wt). Birds were killed after 12, 16, 20, 24, and 28 days of stretch not including rest days. Muscle mass increased 174% (12 days), 196% (16 days), 225% (20 days), 264% (24 days), and 318% (28 days). Muscle length increased 60% (12 days), 34% (16 days), 59% (20 days), 50% (24 days), and 51% (28 days). Mean fiber area increased 111% (12 days), 142% (16 days), 75% (20 days), 90% (24 days), and 39% (28 days). Fiber number, which was measured histologically, increased significantly by 82% only in the 28 days of stretch group. The percentage of slow tonic fibers did not change for any of the time points examined.(ABSTRACT TRUNCATED AT 250 WORDS)


Blood ◽  
1996 ◽  
Vol 87 (1) ◽  
pp. 331-340
Author(s):  
WE Kaminski ◽  
E Jendraschak ◽  
K Baumann ◽  
R Kiefl ◽  
S Fischer ◽  
...  

Lipoxygenases (LXs) catalyze formation of leukotrienes and hydroxy-eicosatetraenoic acids (HETEs), proinflammatory, and spasmogenic autacoids that are critical for host defense systems. We studied the expression and regulation of LX genes (12-LX, 5-LX, and 15-LX) and the 5-lipoxygenase activating protein (FLAP) in human mononuclear cells (MNC) and granulocytes using a quantitative reverse transcription polymerase chain reaction (RT-PCR) technique. We show that 12-LX mRNA is constitutively expressed in resting platelet-free MNC. 12-LX gene expression was upregulated by activation with lipopolysaccharide (LPS). The formation of 12-HETE was inducible with ionophore in MNC, as assessed by high-performance liquid chromatography (HPLC) and gas chromatography, and increased after LPS pretreatment. In addition to 12- LX, resting MNC expressed the genes for 5-LX and FLAP constitutively. Quantitative time course analyses of 12-LX, 5-LX, and FLAP gene expression suggested coregulation of 12-LX and FLAP mRNAs, and reciprocal regulation of 5-LX and FLAP mRNAs. During cell stimulation with LPS 5-LX mRNA levels remained unchanged, whereas FLAP gene expression increased. No 15-LX mRNA expression or 15-HETE formation was detectable in unstimulated and activated MNC. In contrast to MNC, quantitative RT-PCR mRNA analysis showed intermittent intraindividual expression of the 5-LX and FLAP genes in resting granulocytes. mRNAs for 12-LX and 15-LX were not expressed. On stimulation of granulocytes ex vivo, mRNA expression of 5-LX and FLAP was upregulated. Stimulation by LPS differed from that by ionophore A23187. Neither LPS nor ionophore induced gene expression of 12-LX or 15-LX in granulocytes. Our data indicate that resting human MNC and granulocytes express LX and FLAP genes in a cell-specific manner. Cell activation induces coordinated upregulation of 12-LX and FLAP genes in MNC, and 5-LX and FLAP genes in granulocytes, respectively. The constitutive expression of 12-LX mRNA, its upregulation on cell activation, and the formation of 12-HETE clearly indicate the presence of a functional 12-LX in human MNC.


1995 ◽  
Vol 78 (1) ◽  
pp. 293-299 ◽  
Author(s):  
J. A. Carson ◽  
M. Yamaguchi ◽  
S. E. Alway

The purpose of this study was to determined whether fibers in the anterior latissimus dorsi (ALD) muscle from aged Japanese quail have decreased hypertrophic or proliferative responses to 30 days of stretch overload compared with fibers from adult birds. Two groups of quail were studied, 12-wk-old quail (adult; n = 16) and 90-wk-old quail (aged; n = 16). The left wing of each bird was overloaded with a weight corresponding to 10% of the bird's body weight, and the right wing served as the intra-animal control. Quails were killed after 30 days of stretch overload. Total fiber number was quantified by counting all the fibers in a transverse section from the midbelly of the ALD muscle. ALD muscles in aged quails retained the capacity to increase their muscle mass (145%), total fiber number (49%), and fiber cross-sectional area (54%) in response to stretch overload. The ALD muscle in aged quail had a significantly lower increase in muscle mass (33%) and mass corrected for nonmuscle tissue (36%) compared with the ALD from young adult birds. Age had no effect on fiber type distribution shifts with stretch. These results suggest that although muscles in old birds have a substantial ability to adapt to enlarge, stretch-induced hypertrophy is attenuated in muscles from old quail.


1982 ◽  
Vol 92 (1) ◽  
pp. 73-83 ◽  
Author(s):  
H. F. URBANSKI ◽  
B. K. FOLLETT

Male Japanese quail were castrated when sexually immature and immediately exposed to one of the following stimulatory lighting regimes for 52 days: 11 h light: 13 h darkness/day (11L : 13D), 12L : 12D, 13L : 11D, 14L : 10D, 15L : 9D, 16L : 8D, 20L : 4D or 23L : 1D. One group was retained on short days (8L : 16D). Clearcut differences in the plasma levels of LH and FSH emerged between the various groups. Levels remained very low in castrated quail on 8L : 16D but were much greater in those on 14L : 10D, 15L : 9D, 16L : 8D, 20L : 4D and 23L : 1D, eventually becoming 15 to 20 times higher. Less pronounced castration responses developed on 13L : 11D, 12L : 12D or 11L : 13D. Alterations in photoperiod after day 52 caused an appropriate rise or fall in LH secretion. Photoperiodically induced suppressions were rapid, being highly significant within 4 days, but increases usually had a slower time course. When sexually mature quail (on 16L : 8D) were castrated and transferred to 8L : 16D they also exhibited a rapid suppression in LH secretion. Thus in quail, unlike some mammals, the photoperiodic control over gonadotrophin secretion is independent of the reproductive status of the animal at the time of castration. The results confirm the view that changes in sensitivity of the hypothalamo-pituitary axis to gonadal steroids are not a primary factor in the neural mechanisms underlying photoperiodism in quail.


2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Theodora Pavlidou ◽  
Milica Marinkovic ◽  
Marco Rosina ◽  
Claudia Fuoco ◽  
Simone Vumbaca ◽  
...  

The regeneration of the muscle tissue relies on the capacity of the satellite stem cell (SC) population to exit quiescence, divide asymmetrically, proliferate, and differentiate. In age-related muscle atrophy (sarcopenia) and several dystrophies, regeneration cannot compensate for the loss of muscle tissue. These disorders are associated with the depletion of the satellite cell pool or with the loss of satellite cell functionality. Recently, the establishment and maintenance of quiescence in satellite cells have been linked to their metabolic state. In this work, we aimed to modulate metabolism in order to preserve the satellite cell pool. We made use of metformin, a calorie restriction mimicking drug, to ask whether metformin has an effect on quiescence, proliferation, and differentiation of satellite cells. We report that satellite cells, when treated with metformin in vitro, ex vivo, or in vivo, delay activation, Pax7 downregulation, and terminal myogenic differentiation. We correlate the metformin-induced delay in satellite cell activation with the inhibition of the ribosome protein RPS6, one of the downstream effectors of the mTOR pathway. Moreover, in vivo administration of metformin induces a belated regeneration of cardiotoxin- (CTX-) damaged skeletal muscle. Interestingly, satellite cells treated with metformin immediately after isolation are smaller in size and exhibit reduced pyronin Y levels, which suggests that metformin-treated satellite cells are transcriptionally less active. Thus, our study suggests that metformin delays satellite cell activation and differentiation by favoring a quiescent, low metabolic state.


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