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Hypoxia muscle atrophy

Gommaar D'Hulst, Louise Deldicque
Skeletal muscle wasting has been shown to be a mechanism by which humans are able to adapt to extreme altitude. Nonetheless, the literature is conflicting regarding the altitude or time point at which this phenomenon starts to occur. Using the metric recently suggested by Garvivan-Lewis et al. (8), we propose an hypoxic dose of 5000 km·h as the cut-off point above which hypoxia-induced muscle atrophy starts to develop. As such, we suggest that both elevation and hours of altitude exposure should be incorporated in future studies unraveling hypoxic regulation of muscle mass...
October 14, 2016: Journal of Applied Physiology
Teng Ma, Lei Zhu, Yafeng Yang, Xin Quan, Liangliang Huang, Zhongyang Liu, Zhen Sun, Shu Zhu, Jinghui Huang, Zhuojing Luo
Local hypoxia in the early stages of peripheral nerve injury is a challenge for axonal regeneration. To address this issue, perfluorotributylamine (PFTBA)-based oxygen carrying fibrin hydrogel was prepared and injected into Schwann cell (SC)-seeded collagen-chitosan conduits to increase oxygen supply to SCs within the conduits. The conduit containing PFTBA-SC gel was then applied to bridge a 15-mm sciatic nerve defect in rats. It was observed that most of the GFP-labeled SCs initially seeded in the PFTBA hydrogel remained alive for approximately 28 days after their in vivo implantation...
September 4, 2016: Journal of Tissue Engineering and Regenerative Medicine
Corinna Preuße, Yves Allenbach, Olaf Hoffmann, Hans-Hilmar Goebel, Debora Pehl, Josefine Radke, Alexandra Doeser, Udo Schneider, Rieke H E Alten, Tilmann Kallinich, Olivier Benveniste, Arpad von Moers, Benedikt Schoser, Ulrike Schara, Werner Stenzel
Dermatomyositis (DM) can occur in both adults and juveniles with considerable clinical differences. The links between immune-mediated mechanisms and vasculopathy with respect to development of perifascicular pathology are incompletely understood. We investigated skeletal muscle from newly diagnosed, treatment-naïve juvenile (jDM) and adult dermatomyositis (aDM) patients focusing on hypoxia-related pathomechanisms, vessel pathology, and immune mechanisms especially in the perifascicular region. Therefore, we assessed the skeletal muscle biopsies from 21 aDM, and 15 jDM patients by immunohistochemistry and electron microscopy...
2016: Acta Neuropathologica Communications
Tanja Taivassalo, Sabah N A Hussain
COPD is a significant public health challenge, notably set to become the third leading cause of death and fifth leading cause of chronic disability worldwide by the next decade. Skeletal muscle impairment is now recognized as a disabling, extrapulmonary consequence of COPD that is associated with reduced quality of life and premature mortality. Because COPD typically manifests in older individuals, these clinical features may overlie normal age-associated declines in muscle function and performance. Although physical inactivity, oxidative stress, inflammation, hypoxia, malnutrition, and medications all likely contribute to this comorbidity, a better understanding of the underlying mechanism is needed to develop effective therapies...
May 2016: Chest
Philip Lewis, David Sheehan, Renata Soares, Ana Varela Coelho, Ken D O'Halloran
Mechanisms underpinning chronic sustained hypoxia (CH)-induced structural and functional adaptations in respiratory muscles are unclear despite the clinical relevance to respiratory diseases. The objectives of the present study were to thoroughly assess the putative role of CH-induced redox remodeling in murine diaphragm muscle over time and the subsequent effects on metabolic enzyme activities, catabolic signaling and catabolic processes, and diaphragm muscle contractile function. C57Bl6/J mice were exposed to normoxia or normobaric CH (fraction of inspired oxygen = 0...
July 2016: American Journal of Respiratory Cell and Molecular Biology
Roxana Rodríguez-Romo, Kenia Benítez, Jonatan Barrera-Chimal, Rosalba Pérez-Villalva, Arturo Gómez, Diana Aguilar-León, Jesús F Rangel-Santiago, Sara Huerta, Gerardo Gamba, Norma Uribe, Norma A Bobadilla
Despite clinical recovery of patients from an episode of acute kidney injury (AKI), progression to chronic kidney disease (CKD) is possible on long-term follow-up. However, mechanisms of this are poorly understood. Here, we determine whether activation of angiotensin-II type 1 receptors during AKI triggers maladaptive mechanisms that lead to CKD. Nine months after AKI, male Wistar rats develop CKD characterized by renal dysfunction, proteinuria, renal hypertrophy, glomerulosclerosis, tubular atrophy, and tubulointerstitial fibrosis...
February 2016: Kidney International
Eilidh Somers, Robert D Lees, Katie Hoban, James N Sleigh, Haiyan Zhou, Francesco Muntoni, Kevin Talbot, Thomas H Gillingwater, Simon H Parson
OBJECTIVE: Spinal muscular atrophy (SMA) is a major inherited cause of infant death worldwide. It results from mutations in a single, ubiquitously expressed gene (SMN1), with loss of lower motor neurons being the primary pathological signature. Systemic defects have also been reported in SMA patients and animal models. We investigated whether defects associated with the vasculature contribute to motor neuron pathology in SMA. METHODS: Development and integrity of the capillary bed was examined in skeletal muscle and spinal cord of SMA mice, and muscle biopsies from SMA patients and controls, using quantitative morphometric approaches on immunohistochemically labeled tissue...
February 2016: Annals of Neurology
Xiangwei Liu, Xiaolei Sun, Hua Liao, Zhen Dong, Jingjing Zhao, Hong Zhu, Peng Wang, Li Shen, Lei Xu, Xin Ma, Cheng Shen, Fan Fan, Cong Wang, Kai Hu, Yunzeng Zou, Junbo Ge, Jun Ren, Aijun Sun
OBJECTIVE: Revascularization is an essential process to compensate for cardiac underperfusion and, therefore, preserves cardiac function in the face of chronic ischemic injury. Recent evidence suggested a vital role of aldehyde dehydrogenase 2 (ALDH2) in cardiac protection after ischemia. This study was designed to determine whether ALDH2 regulates chronic ischemia-induced angiogenesis and to explore the underlying mechanism involved. Moreover, the clinical impact of the ALDH2 mutant allele on the development of coronary collateral circulation (CCC) was evaluated...
October 2015: Arteriosclerosis, Thrombosis, and Vascular Biology
F B Favier, F A Britto, D G Freyssenet, X A Bigard, H Benoit
Skeletal muscle is a metabolically active tissue and the major body protein reservoir. Drop in ambient oxygen pressure likely results in a decrease in muscle cells oxygenation, reactive oxygen species (ROS) overproduction and stabilization of the oxygen-sensitive hypoxia-inducible factor (HIF)-1α. However, skeletal muscle seems to be quite resistant to hypoxia compared to other organs, probably because it is accustomed to hypoxic episodes during physical exercise. Few studies have observed HIF-1α accumulation in skeletal muscle during ambient hypoxia probably because of its transient stabilization...
December 2015: Cellular and Molecular Life Sciences: CMLS
Christian Giordano, Christian Lemaire, Tong Li, R John Kimoff, Basil J Petrof
BACKGROUND: Short-term intermittent hypoxia (IH) is common in patients with acute respiratory disorders. Although prolonged exposure to hypoxia induces atrophy and increased fatigability of skeletal muscle, the response to short-term IH is less well known. We hypothesized that the diaphragm and limb muscles would adapt differently to short-term IH given that hypoxia stimulates ventilation and triggers a superimposed exercise stimulus in the diaphragm. METHODS: We determined the structural, metabolic, and contractile properties of the mouse diaphragm after 4 days of IH (8 hours per day, 30 episodes per hour to a FiO2 nadir=6%), and compared responses in the diaphragm to a commonly studied reference limb muscle, the tibialis anterior...
2015: PloS One
Jesus Prieto-Lloret, Maria Ramirez, Elena Olea, Javier Moral-Sanz, Angel Cogolludo, Javier Castañeda, Sara Yubero, Teresa Agapito, Angela Gomez-Niño, Asuncion Rocher, Ricardo Rigual, Ana Obeso, Francisco Perez-Vizcaino, Constancio González
KEY POINTS: Adult animals that have been perinatally exposed to oxygen-rich atmospheres (hyperoxia), recalling those used for oxygen therapy in infants, exhibit a loss of hypoxic pulmonary vasoconstriction, whereas vasoconstriction elicited by depolarizing agents is maintained. Loss of pulmonary hypoxic vasoconstriction is not linked to alterations in oxygen-sensitive K(+) currents in pulmonary artery smooth muscle cells. Loss of hypoxic vasoconstriction is associated with early postnatal oxidative damage and corrected by an antioxidant diet...
June 1, 2015: Journal of Physiology
Portia Thurmond, Jing-Hua Yang, Yedan Li, Lori B Lerner, Kazem M Azadzoi
PURPOSE: Clinical studies have reported a correlation between pelvic ischemia and voiding dysfunction in elderly men. The aim of this study was to identify and compare prostate structural modifications in cultured cells and in a rabbit model after exposure to hypoxia, oxidative stress, and chronic ischemia. MATERIALS AND METHODS: Cultured human prostate smooth muscle cells (SMCs), epithelial cells (ECs), and stromal cells (SCs) were incubated under normoxia, hypoxia, and oxidative stress conditions by use of a computerized oxycycler system...
March 2015: Korean Journal of Urology
H C Heitkamp
Blood flow restriction training has proven to be effective, but it is not well known and is limited by initially producing discomfort. Blood flow restriction (BFR) induces hypoxia and metabolic effects, as well as reduction of proteolysis and induction of anabolic processes. Growth hormone levels are regularly increased. Controversies exist concerning neuromuscular effects. Twenty-eight of 30 studies, showed an increase in strength usually associated with muscle hypertrophy in both men and women, although data for women are sparse...
May 2015: Journal of Sports Medicine and Physical Fitness
Andreia F Fernandes, Heather Fenton, Shannon Martinson, Marion Desmarchelier, Shannon T Ferrell
An approximately 6-mo-old female bald eagle (Haliaeetus leucocephalus) was presented for an inability to fly and bilateral drooped wings. Pectoral muscle atrophy with a moderate polycythemia was present. Over the course of 3 wk, there were no improvements in flight capacity, although the bird gained substantial weight. Further investigation revealed a prominent cyanosis that was responsive to oxygen therapy, a chronic respiratory acidosis with hypoxia, a cardiac murmur, and a persistent polycythemia. No obvious antemortem etiology for the clinical findings was discovered on computerized tomography, angiography, or echocardiography...
December 2014: Journal of Zoo and Wildlife Medicine: Official Publication of the American Association of Zoo Veterinarians
C C de Theije, R C J Langen, W H Lamers, H R Gosker, A M W J Schols, S E Köhler
Hypoxia as a consequence of acute and chronic respiratory disease has been associated with muscle atrophy. This study investigated the sensitivity of oxidative and glycolytic muscles to hypoxia-induced muscle atrophy. Male mice were exposed to 8% normobaric oxygen for up to 21 days. Oxidative soleus and glycolytic extensor digitorum longus (EDL) muscles were isolated, weighed, and assayed for expression profiles of the ubiquitin-proteasome system (UPS), the autophagy-lysosome pathway (ALP), and glucocorticoid receptor (GR) and hypoxia-inducible factor-1α (HIF1α) signaling...
January 15, 2015: Journal of Applied Physiology
Florian A Britto, Gwenaelle Begue, Bernadette Rossano, Aurélie Docquier, Barbara Vernus, Chamroeun Sar, Arnaud Ferry, Anne Bonnieu, Vincent Ollendorff, François B Favier
REDD1 (regulated in development and DNA damage response 1) has been proposed to inhibit the mechanistic target of rapamycin complex 1 (mTORC1) during in vitro hypoxia. REDD1 expression is low under basal conditions but is highly increased in response to several catabolic stresses, like hypoxia and glucocorticoids. However, REDD1 function seems to be tissue and stress dependent, and its role in skeletal muscle in vivo has been poorly characterized. Here, we investigated the effect of REDD1 deletion on skeletal muscle mass, protein synthesis, proteolysis, and mTORC1 signaling pathway under basal conditions and after glucocorticoid administration...
December 1, 2014: American Journal of Physiology. Endocrinology and Metabolism
Dustin R Slivka, Matthew W S Heesch, Charles L Dumke, John S Cuddy, Walter S Hailes, Brent C Ruby
BACKGROUND: The ability to physically perform at high altitude may require unique strategies to acclimatize before exposure. The effect of acute hypoxic exposure on the metabolic response of the skeletal muscle may provide insight into the value of short-term preacclimatization strategies. OBJECTIVE: To determine the human skeletal muscle response to a single acute bout of exercise in a hypoxic environment on metabolic gene expression. METHODS: Eleven recreationally active male participants (24 ± 4 years, 173 ± 20 cm, 82 ± 12 kg, 15...
December 2014: Wilderness & Environmental Medicine
Shanjun Ma, Tianjian Zhou
OBJECTIVE: To evaluate the effectiveness of the median nerve constrictive operation combined with tendon transfer to treat the brain paralysis convulsive deformity of the hand. METHODS: The clinical data from 21 cases with brain paralysis convulsive deformity of the hand were analyzed retrospectively between August 2009 and April 2012. Of them, there were 13 males and 8 females with an average age of 15 years (range, 10-29 years). The causes of the convulsive cerebral palsy included preterm deliveries in 11 cases, hypoxia asphyxia in 7, traumatic brain injury in 2, and encephalitis sequela in 1...
May 2014: Chinese Journal of Reparative and Reconstructive Surgery
Tatsuya Noguchi, Yoshihiko Kakinuma, Mikihiko Arikawa, Kayo Okazaki, Eri Hoshino, Tatsuo Iiyama, Toru Kubo, Hiroaki Kitaoka, Yoshinori Doi, Takayuki Sato
BACKGROUND: Saving more limbs of patients with peripheral arterial disease (PAD) from amputation by accelerating angiogenesis in affected limbs has been anticipated for years. We hypothesized that an anti-Alzheimer drug, donepezil (DPZ), can activate angiomyogenic properties of satellite cells, myogenic progenitors, and thus be an additional pharmacological therapy against PAD. METHODS AND RESULTS: In a murine hindlimb ischemia model, we investigated the angiogenic effects of a clinical dose of DPZ (0...
2014: Circulation Journal: Official Journal of the Japanese Circulation Society
Simon Hauerslev, John Vissing, Thomas O Krag
Muscular dystrophies comprise a large group of inherited disorders that lead to progressive muscle wasting. We wanted to investigate if targeting satellite cells can enhance muscle regeneration and thus increase muscle mass. We treated mice with hepatocyte growth factor and leukemia inhibitory factor under three conditions: normoxia, hypoxia and during myostatin deficiency. We found that hepatocyte growth factor treatment led to activation of the Akt/mTOR/p70S6K protein synthesis pathway, up-regulation of the myognic transcription factors MyoD and myogenin, and subsequently the negative growth control factor, myostatin and atrophy markers MAFbx and MuRF1...
2014: PloS One
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