scholarly journals Simultaneous Isolation of Stem and Niche Cells of Skeletal Muscle: Applicability for Aging Studies

Author(s):  
Eusebio Perdiguero ◽  
Victoria Moiseeva ◽  
Pura Muñoz-Cánoves
Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6410
Author(s):  
Sandra Magalhães ◽  
Idália Almeida ◽  
Filipa Martins ◽  
Fátima Camões ◽  
Ana R. Soares ◽  
...  

Studying aging is important to further understand the molecular mechanisms underlying this physiological process and, ideally, to identify a panel of aging biomarkers. Animals, in particular mice, are often used in aging studies, since they mimic important features of human aging, age quickly, and are easy to manipulate. The present work describes the use of Fourier Transform Infrared (FTIR) spectroscopy to identify an age-related spectroscopic profile of the cardiac and skeletal muscle tissues of C57BL/6J female mice. We acquired ATR-FTIR spectra of cardiac and skeletal muscle at four different ages: 6; 12; 17 and 24 months (10 samples at each age) and analyzed the data using multivariate statistical tools (PCA and PLS) and peak intensity analyses. The results suggest deep changes in protein secondary structure in 24-month-old mice compared to both tissues in 6-month-old mice. Oligomeric structures decreased with age in both tissues, while intermolecular β-sheet structures increased with aging in cardiac muscle but not in skeletal muscle. Despite FTIR spectroscopy being unable to identify the proteins responsible for these conformational changes, this study gives insights into the potential of FTIR to monitor the aging process and identify an age-specific spectroscopic signature.


Author(s):  
Chiara Cencioni ◽  
Johanna Heid ◽  
Anna Keprelova ◽  
Seyed Mohammad Mahdi Rasa ◽  
Carsten Kuenne ◽  
...  

Aging associates with progressive loss of skeletal muscle function leading up to sarcopenia, a process characterized by impaired mobility and weakening of muscle strength. Molecular mechanisms underpinning sarcopenia are still poorly characterized. Since aging associates with profound epigenetic changes, epigenetic landscape alteration analysis in the skeletal muscle promises to highlight molecular mechanisms of age-associated sarcopenia. The study was conducted exploiting the short-lived turquoise killifish Nothobranchius furzeri (Nfu), a relatively new model for aging studies. The epigenetic analysis suggested for a less accessible and more condensed chromatin in old Nfu skeletal muscle. Specifically, an accumulation of heterochromatin regions was observed as consequence of increased levels of H3K27me3, HP1alpha, polycomb complex subunits and senescence associated heterochromatic foci (SAHFs). Consistently, euchromatin histone marks, including H3K9ac, decreased. The integrative bioinformatics analysis of RNASeq and ChIPSeq, related to skeletal muscle of Nfu at different ages, revealed a down-modulation of genes involved in cell cycle, differentiation and DNA repair and an up-regulation of inflammation and senescence genes. Undoubtedly, more studies are needed to disclose the detailed mechanisms, but this approach revealed an unprecedented specific features of Nfu skeletal muscle aging, potentially associated with sarcopenia onset and consequent impairment of swimming and mobility typical of old Nfu.


Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1169 ◽  
Author(s):  
Chiara Cencioni ◽  
Johanna Heid ◽  
Anna Krepelova ◽  
Seyed Mohammad Mahdi Rasa ◽  
Carsten Kuenne ◽  
...  

Aging associates with progressive loss of skeletal muscle function, sometimes leading to sarcopenia, a process characterized by impaired mobility and weakening of muscle strength. Since aging associates with profound epigenetic changes, epigenetic landscape alteration analysis in the skeletal muscle promises to highlight molecular mechanisms of age-associated alteration in skeletal muscle. This study was conducted exploiting the short-lived turquoise killifish Nothobranchius furzeri (Nfu), a relatively new model for aging studies. The epigenetic analysis suggested a less accessible and more condensed chromatin in old Nfu skeletal muscle. Specifically, an accumulation of heterochromatin regions was observed as a consequence of increased levels of H3K27me3, HP1α, polycomb complex subunits, and senescence-associated heterochromatic foci (SAHFs). Consistently, euchromatin histone marks, including H3K9ac, were significantly reduced. In this context, integrated bioinformatics analysis of RNASeq and ChIPSeq, related to skeletal muscle of Nfu at different ages, revealed a down-modulation of genes involved in cell cycle, differentiation, and DNA repair and an up-regulation of inflammation and senescence genes. Undoubtedly, more studies are needed to disclose the detailed mechanisms; however, our approach enlightened unprecedented features of Nfu skeletal muscle aging, potentially associated with swimming impairment and reduced mobility typical of old Nfu.


Author(s):  
D. E. Philpott ◽  
A. Takahashi

Two month, eight month and two year old rats were treated with 10 or 20 mg/kg of E. Coli endotoxin I. P. The eight month old rats proved most resistant to the endotoxin. During fixation the aorta, carotid artery, basil arartery of the brain, coronary vessels of the heart, inner surfaces of the heart chambers, heart and skeletal muscle, lung, liver, kidney, spleen, brain, retina, trachae, intestine, salivary gland, adrenal gland and gingiva were treated with ruthenium red or alcian blue to preserve the mucopolysaccharide (MPS) coating. Five, 8 and 24 hrs of endotoxin treatment produced increasingly marked capillary damage, disappearance of the MPS coating, edema, destruction of endothelial cells and damage to the basement membrane in the liver, kidney and lung.


Author(s):  
Joachim R. Sommer ◽  
Nancy R. Wallace

After Howell (1) had shown that ruthenium red treatment of fixed frog skeletal muscle caused collapse of the intermediate cisternae of the sarcoplasmic reticulum (SR), forming a pentalaminate structure by obi iterating the SR lumen, we demonstrated that the phenomenon involves the entire SR including the nuclear envelope and that it also occurs after treatment with other cations, including calcium (2,3,4).From these observations we have formulated a hypothesis which states that intracellular calcium taken up by the SR at the end of contraction causes the M rete to collapse at a certain threshold concentration as the first step in a subsequent centrifugal zippering of the free SR toward the junctional SR (JSR). This would cause a) bulk transport of SR contents, such as calcium and granular material (4) into the JSR and, b) electrical isolation of the free SR from the JSR.


Author(s):  
A. V. Somlyo ◽  
H. Shuman ◽  
A. P. Somlyo

Electron probe analysis of frozen dried cryosections of frog skeletal muscle, rabbit vascular smooth muscle and of isolated, hyperpermeab1 e rabbit cardiac myocytes has been used to determine the composition of the cytoplasm and organelles in the resting state as well as during contraction. The concentration of elements within the organelles reflects the permeabilities of the organelle membranes to the cytoplasmic ions as well as binding sites. The measurements of [Ca] in the sarcoplasmic reticulum (SR) and mitochondria at rest and during contraction, have direct bearing on their role as release and/or storage sites for Ca in situ.


Author(s):  
Joachim R. Sommer ◽  
Teresa High ◽  
Betty Scherer ◽  
Isaiah Taylor ◽  
Rashid Nassar

We have developed a model that allows the quick-freezing at known time intervals following electrical field stimulation of a single, intact frog skeletal muscle fiber isolated by sharp dissection. The preparation is used for studying high resolution morphology by freeze-substitution and freeze-fracture and for electron probe x-ray microanlysis of sudden calcium displacement from intracellular stores in freeze-dried cryosections, all in the same fiber. We now show the feasibility and instrumentation of new methodology for stimulating a single, intact skeletal muscle fiber at a point resulting in the propagation of an action potential, followed by quick-freezing with sub-millisecond temporal resolution after electrical stimulation, followed by multiple sampling of the frozen muscle fiber for freeze-substitution, freeze-fracture (not shown) and cryosectionmg. This model, at once serving as its own control and obviating consideration of variances between different fibers, frogs etc., is useful to investigate structural and topochemical alterations occurring in the wake of an action potential.


Author(s):  
C. Uphoff ◽  
C. Nyquist-Battie ◽  
T.B. Cole

Ultrastructural alterations of skeletal muscle have been observed in adult chronic alcoholic patients. However, no such study has been performed on individuals prenatally exposed to ethanol. In order to determine if ethanol exposure in utero in the latter stages of muscle development was deleterious, skeletal muscle was obtained from newborn guinea pigs treated in the following manner. Six Hartly strain pregnant guinea pigs were randomly assigned to either the ethanol or the pair-intubated groups. Twice daily the 3 ethanol-treated animals were intubated with Ensure (Ross Laboratories) liquid diet containing 30% ethanol (6g/Kg pre-pregnant body weight per day) from day 35 of gestation until parturition at day 70±1 day. Serum ethanol levels were determined at 1 hour post-intubation by the Sigma alcohol test kit. For pair-intubation the Ensure diet contained sucrose substituted isocalorically for ethanol. Both food and water intake were monitored.


Author(s):  
S.L. White ◽  
C.B. Jensen ◽  
D.D. Giera ◽  
D.A. Laska ◽  
M.N. Novilla ◽  
...  

In vitro exposure to LY237216 (9-Deoxo-11-deoxy-9,11-{imino[2-(2-methoxyethoxy)ethylidene]-oxy}-(9S)-erythromycin), a macrolide antibiotic, was found to induce cytoplasmic vacuolation in L6 skeletal muscle myoblast cultures (White, S.L., unpubl). The present study was done to determine, by autoradiographic quantitative analysis, the subcellular distribution of 3H-LY237216 in L6 cells.L6 cells (ATCC, CRL 1458) were cultured to confluency on polycarbonate membrane filters (Millipore Corp., Bedford, MA) in M-199 medium (GIBCO® Labs) with 10% fetal bovine serum. The cells were exposed from the apical surface for 1-hour to unlabelled-compound (0 μCi/ml) or 50 (μCi/ml of 3H-LY237216 at a compound concentration of 0.25 mg/ml. Following a rapid rinse in compound-free growth medium, the cells were slam-frozen against a liquid nitrogen cooled, polished copper block in a CF-100 cryofixation unit (LifeCell Corp., The Woodlands, TX). Specimens were dried in the MDD-C Molecular Distillation Drier (LifeCell Corp.), vapor osmicated and embedded in Spurrs low viscosity resin. Ultrathin sections collected on formvar coated stainless steel grids were counter-stained, then individually mounted on corks. A monolayer of Ilford L4 nuclear emulsion (Polysciences, Inc., Warrington, PA) was placed on the sections, utilizing a modified “loop method”. The emulsions were exposed for 7-weeks in a light-tight box at 4°C. Autoradiographs were developed in Microdol-X developer and examined on a Philips EM410LS transmission electron microscope. Quantitative analysis of compound localization employed the point and circle approach of Williams; incorporating the probability circle method of Salpeter and McHenry.


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