1,720,967 research outputs found
Artesunate induces ROS-mediated apoptosis and counteracts tumor growth in vivo in embryonal rhabdomyosarcoma cells.
No full textEmbryonal rhabdomyosarcoma (ERMS) is the most common soft tissue sarcoma in childhood, and is characterized by the expression of muscle-specific transcription factors and overexpression of PAX7 [1]. Thus, ERMS has been suggested to have an origin in muscle precursor cells that fail to exit the cell cycle and terminally differentiate. Artesunate (ARS) is a semi-synthetic derivate of artemisinin, a Chinese-medicine compound long known as a very effective anti-malarial drug. More recently, artemisinin and its derivatives have been found effective as anticancer drugs since they induce cell cycle arrest or apoptosis in several kinds of cancer [2]. Here we demonstrate that ARS dose-dependently induces cell cycle arrest and apoptosis in the ERMS cell lines, TE671 and RD18. Production of reactive oxygen species (ROS) and activation of p38 MAPK have a central role in triggering ARS-mediated apoptosis in ERMS cells, since either the antioxidant and ROS scavenger, N-acetylcysteine (NAC), or the p38 inhibitor, SB203580, protects ERMS cells from ARS-induced apoptosis. Moreover, ARS treatment in ERMS cells ROS-dependently induces the expression of the specific myo-miRs, miR-133a and miR-206, which are typically down-regulated in ERMS, and downregulates PAX7 expression. Finally, ARS upregulates the expression of the adhesion molecules, NCAM and integrin 1, and reduces migration and invasiveness in ERMS cells in vitro, and ARS treatment reduces ERMS tumor growth in vivo. Our results suggest ARS as a potential candidate for the therapeutic treatment of ERMS.
1. Parham D.M. and Ellison D.A. (2006) Rhabdomyosarcomas in adults and children. An update. Arch. Pathol. Lab. Med. 130:1454-1465
2. Crespo-Ortiz M.P. and Wei M.Q. (2012) Antitumor activity of artemisinin and its derivatives: from a well-known antimalarial agent to a potential anticancer drug. J. Biomed. Biotechnol. 2012:24759
Different intrinsic properties of young and aged human satellite cells.
No full textDuring aging, skeletal muscles undergo a decline in functional capacity due to loss of regenerative ability of satellite cells (SCs), the quiescent stem cells located beneath the basal lamina surrounding each myofiber. There is debate about the influence of age-related extrinsic factors on SC efficiency (the SC niche) vs age-related intrinsic cellular properties of the SCs (1).
In the present work we analyzed several parameters of SCs derived from biopsies from Vastus Lateralis muscle from both healthy non-trained young and aged humans [male and female, divided into young (mean age 31.6 ± 3.6 years; n=5) and aged (mean age 77.3 ± 5.8 years; n=7)].
Aged SCs showed impaired differentiation ability [i.e., lower extent of fusion into myotubes and reduced expression of myogenin and myosin heavy chain, when cultured in differentiation medium (DM)], compared with young SCs, and were characterized by the following: i) a stronger expression of S100B, a Ca2+-binding protein the overexpression of which has been found to interfere with myoblast differentiation (Tubaro C et al., submitted for publication); ii) undetectable levels of full-length RAGE (receptor for advanced glycation end products) protein, a multiligand receptor the engagement of which enhances myoblast differentiation (2), in growth medium (GM), and cytosolic instead of membrane localization of RAGE in DM; and iii) lower expression levels of MyoD and Pax7 transcription factors, in both GM and DM.
These data point to an important role for intrinsic factors, besides extrinsic factors, in defective SC function during aging
Young and Aged Human Muscle Satellite Cells Show Differential Expression of S100B Protein and RAGE.
No full textDuring aging, skeletal muscles show reduced functional capacity due to loss of the regenerative ability of satellite cells (SCs), the quiescent stem cells located beneath the basal lamina
surrounding each myofiber. Both age-related extrinsic factors and age-related intrinsic properties of SCs appear to contribute to SC efficiency (Aging Cell 7 (2008) 590-8). In the present work we analyzed several parameters of SCs derived from biopsies of Vastus Lateralis muscle from healthy non-trained young and aged humans (male and female, divided into young [mean age
31.0 ± 5.35 years; n=7] and aged [mean age 76.44 ± 6.12 years; n=9]). Compared to young SCs, aged SCs showed impaired differentiation, i.e. reduced myotube formation and reduced expression of myogenin and myosin heavy chain when cultured in differentiation medium (DM), and exhibited the following: i) reduced proliferation; ii) higher expression levels of S100B, a Ca2+-binding protein and negative regulator of myoblast differentiation (submitted for publication); iii)
undetectable levels of full-length RAGE (receptor for advanced glycation end products), a multiligand receptor of the immunoglobulin superfamily the engagement of which enhances
myoblast differentiation (Mol Cell Biol 24 (2004) 4880-4894; J Biol Chem 281 (2006) 8242-8253), and presence of a truncated form of RAGE in growth medium (GM) the amount of which
decreased in DM in parallel with appearance of full-length RAGE; and iv) lower expression levels of the transcription factors, MyoD and Pax7, in both GM and DM. Also, transient transfection of
young SCs with S100B expression vector resulted in reduced differentiation compared to controls (i.e., acquisition of an aged phenotype), while either transfection of aged SCs with full-length RAGE expression vector or knocking down S100B by siRNA resulted in enhanced differentiation (i.e., acquisition of a young phenotype). These data point to an important role for intrinsic factors (e.g., MyoD, Pax7, S100B and RAGE) in defective SC function in aged skeletal muscles
Human muscle satellite cells show age-related differential expression of S100B protein and RAGE.
No full textDuring aging, skeletal muscles show reduced mass and functional capacity largely due to loss of the regenerative ability of satellite cells (SCs), the quiescent stem cells located beneath the basal lamina surrounding each myofiber. While both the external environment and intrinsic properties of SCs appear to contribute to the age-related SC deficiency, the latter ones have been poorly investigated especially in humans. In the present work, we analyzed several parameters of SCs derived from biopsies of vastus lateralis muscle from healthy non-trained young (28.7 ± 5.9 years; n = 10) and aged (77.3 ± 6.4 years; n = 11) people. Compared with young SCs, aged SCs showed impaired differentiation when cultured in differentiation medium, and exhibited the following: (1) reduced proliferation; (2) higher expression levels of S100B, a negative regulator of myoblast differentiation; (3) undetectable levels in growth medium of full-length RAGE (receptor for advanced glycation end products), a multiligand receptor of the immunoglobulin superfamily, the engagement of which enhances myoblast differentiation; and (4) lower expression levels of the transcription factors, MyoD and Pax7. Also, either overexpression of full-length RAGE or knockdown of S100B in aged SCs resulted in enhanced differentiation, while overexpression of either a non-transducing mutant of RAGE (RAGEΔcyto) or S100B in young SCs resulted in reduced differentiation compared with controls. Moreover, while aged SCs maintained the ability to respond to mitogenic factors (e.g., bFGF and S100B), they were no longer able to secrete these factors, unlike young SCs. These data support a role for intrinsic factors, besides the extracellular environment in the defective SC function in aged skeletal muscles
Artesunate induces ROS- and p38 MAPK-mediated apoptosis and counteracts tumor growth in vivo in embryonal rhabdomyosarcoma cells
No full textRhabdomyosarcoma represents about 50% of soft-tissue sarcomas and 10% of malignant solid tumors in childhood. Embryonal rhabdomyosarcoma (ERMS) is the most frequent subtype, suggested to have an origin in muscle precursor cells that fail to exit the cell cycle and terminally differentiate mainly because of overexpression of the transcription factor, PAX7, which sustains proliferation, migration and invasiveness in ERMS cells. Artesunate (ARS) is a semi-synthetic derivative of artemisinin, a natural compound well known as an anti-malarial drug. However, artemisinin and its derivatives have been found efficacious even as anticancer drugs that induce cell cycle arrest and/or apoptosis in several kinds of cancer. Here we show that ARS dose-dependently induces DNA damage and apoptosis in ERMS cell lines. Production of reactive oxygen species (ROS) and activation of p38 MAPK have a central role in triggering ARS-mediated apoptosis in ERMS cells; indeed either the antioxidant, N-acetylcysteine, or the p38 MAPK inhibitor, SB203580, protects ERMS cells from ARS-induced apoptosis. Moreover, ARS treatment in ERMS cells ROS-dependently induces the expression of the myo-miRs, miR-133a and miR-206, which are down-regulated in RMS, and reduces PAX7 protein levels. Finally, ARS upregulates the expression of the adhesion molecules, NCAM and integrin β1, and reduces migration and invasiveness of ERMS cells in vitro, and ARS treatment reduces of about 50% the growth of ERMS xenografts in vivo. Our results are the first evidence of efficacy of artemisinin derivatives in restraining ERMS growth in vivo, and suggest ARS as a potential candidate for therapeutic treatment of ERMS
Differential expression of S100B protein and RAGE in young and aged human satellite cells.
No full textDuring aging, skeletal muscles undergo a decline of functional capacity due to loss of regenerative ability of satellite cells (SCs), the quiescent stem cells located beneath the basal lamina surrounding each myofiber. There is debate about the influence of age-related extrinsic factors on SC efficiency (the SC niche theory) vs. age-related intrinsic properties of SCs (1). In the present work we analyzed several parameters of SCs derived from biopsies from Vastus Lateralis muscle from healthy non-trained young and aged humans (male and female, divided into young [mean age 31.6 ± 3.6 years; n=5] and aged [mean age 77.3 ± 5.8 years; n=7]). Aged SCs showed impaired differentiation manifested as a smaller extent of fusion into myotubes and reduced expression of myogenin and myosin heavy chain when cultured in differentiation medium (DM), compared to young SCs, and were characterized by the following: 1) reduced proliferation; 2) higher expression levels of S100B, a Ca2+-binding protein the overexpression of which has been found to interfere with myoblast differentiation (C. Tubaro et al., submitted for publication); 3) undetectable levels of full-length RAGE (receptor for advanced glycation end products) protein, a multiligand receptor of the immunoglobulin superfamily the engagement of which enhances myoblast differentiation (2), and presence of a membrane-bound, truncated form of RAGE in growth medium (GM) the amount of which decreased in DM in parallel with appearance of full-length RAGE; and 4) lower expression levels of the transcription factors, MyoD and Pax7, in both GM and DM. Also, transient transfection of young SCs with S100B expression vector resulted in a reduced differentiation potential compared to controls (i.e., acquisition of an aged phenotype), while transfection of aged SCs with full-length RAGE expression vector resulted in an enhanced differentiation (i.e., acquisition of a young phenotype). By contrast, transient transfection of young SCs with RAGEΔcyto, a RAGE mutant lacking the cytoplasmic and transducing domain, resulted in a reduced differentiation potential compared to controls. These data point to an important role for intrinsic factors (e.g., MyoD, Pax7, S100B and RAGE), besides extrinsic factors, in defective SC function in aged skeletal muscles.
1. Gopinath SD and Rando TA (2008) Aging Cell 7:590-8; 2. Sorci G et al. (2004) Mol Cell Biol 24:4880-94
Aged vs young human satellite cells: altered expression of S100B and RAGE, and defective ability in conditioning the medium contribute to impaired myogenic potential.
No full textAge-dependent imbalance of the antioxidative system in human satellite cells.
No full textThe mature myofibres of human skeletal muscle are surrounded by a type of adult stem cell, known as the satellite cell, which lies outside the sarcolemma but within the basal lamina. These cells remain quiescent until external stimuli trigger their re-entry into the cell cycle. In humans, ageing is characterised by a progressive loss of muscle mass and strength (sarcopenia) associated with a decline in functional ability. One of the possible causes of this decline in muscle performance is a decrease in the antioxidative capacity of skeletal muscle, resulting in an abnormal accumulation of the reactive oxygen species (ROS) critical for cell life. The present study shows that: (i) the antioxidant activity of Catalase and Gluthatione transferase in satellite cells derived from the elderly is drastically reduced compared to that in cells isolated from young individuals; (ii) cell membrane fluidity is considerably different between the two age groups; and (iii) basal [Ca2+]i levels in satellite cells increase significantly in an age-dependent manner. In view of the data obtained, we hypothesise that the destabilising oxidative damage that occurs during ageing in skeletal muscle also affects quiescent satellite cells, which spend their life in close anatomic and functional contact with adult fibres. This status is derived from a decrease in the antioxidative capacity, and may negatively affect the ageing satellite cells ability to repair muscle
Age-dependent imbalance of the antioxidative system in human satellite cells
No full text: The mature myofibres of human skeletal muscle are surrounded by a type of adult stem cell, known as the satellite cell, which lies outside the sarcolemma but within the basal lamina. These cells remain quiescent until external stimuli trigger their re-entry into the cell cycle. In humans, ageing is characterised by a progressive loss of muscle mass and strength (sarcopenia) associated with a decline in functional ability. One of the possible causes of this decline in muscle performance is a decrease in the antioxidative capacity of skeletal muscle, resulting in an abnormal accumulation of the reactive oxygen species (ROS) critical for cell life. The present study shows that: (i) the antioxidant activity of Catalase and Gluthatione transferase in satellite cells derived from the elderly is drastically reduced compared to that in cells isolated from young individuals; (ii) cell membrane fluidity is considerably different between the two age groups; and (iii) basal [Ca(2+)](i) levels in satellite cells increase significantly in an age-dependent manner. In view of the data obtained, we hypothesise that the destabilising oxidative damage that occurs during ageing in skeletal muscle also affects quiescent satellite cells, which spend their life in close anatomic and functional contact with adult fibres. This status is derived from a decrease in the antioxidative capacity, and may negatively affect the ageing satellite cells ability to repair muscle
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