scholarly journals TAT-μUtrophin mitigates the pathophysiology of dystrophin and utrophin double-knockout mice

2011 ◽  
Vol 111 (1) ◽  
pp. 200-205 ◽  
Author(s):  
Jarrod A. Call ◽  
James M. Ervasti ◽  
Dawn A. Lowe
Keyword(s):  
Knockout Mice ◽  
Skeletal Muscles ◽  
Ex Vivo ◽  
Eccentric Contraction ◽  
Mdx Mice ◽  
Double Knockout ◽  
Replacement Treatment ◽  
Generating Capacity

Previously, we demonstrated functional substitution of dystrophin by TAT-μUtrophin (TAT-μUtr) in dystrophin-deficient mdx mice. Herein, we addressed whether TAT-μUtr could improve the phenotype of dystrophin and utrophin double-knockout ( mdx:utr−/−) mice. Specifically, we quantitatively compared survival and quality of life assessments in mdx:utr−/− mice receiving TAT-μUtr protein administration against placebo-treated mdx:utr−/− mice (PBS). Additionally, skeletal muscles from TAT-μUtr and PBS mice were tested in vivo and ex vivo for strength and susceptibility to eccentric contraction-induced injury. We found the TAT-μUtr treatment extended life span 45% compared with mice administered PBS. This was attributed to significantly increased food consumption (3.1 vs. 1.8 g/24 h) due to improved ability to search for food as daily cage activities were greater in TAT-μUtr mice (e.g., 364 vs. 201 m ambulation/24 h). The extensor digitorum longus muscles of TAT-μUtr-treated double-knockout mice also displayed increased force-generating capacity ex vivo (8.3 vs. 6.4 N/cm2) and decreased susceptibility to injury ex vivo and in vivo. These data indicate that the functional benefits of TAT-μUtr replacement treatment extend to the mdx:utr−/− double-knockout mouse and support its development as a therapy to mitigate muscle weakness in patients with Duchenne muscular dystrophy.

scholarly journals Adaptive strength gains in dystrophic muscle exposed to repeated bouts of eccentric contraction

2011 ◽  
Vol 111 (6) ◽  
pp. 1768-1777 ◽  
Author(s):  
Jarrod A. Call ◽  
Michael D. Eckhoff ◽  
Kristen A. Baltgalvis ◽  
Gordon L. Warren ◽  
Dawn A. Lowe
Keyword(s):  
Functional Recovery ◽  
Extensor Digitorum Longus ◽  
Eccentric Contraction ◽  
Extensor Digitorum ◽  
Eccentric Contractions ◽  
Mdx Mice ◽  
Dystrophic Muscle ◽  
Generating Capacity ◽  
Isometric Torque

The objective of this study was to determine the functional recovery and adaptation of dystrophic muscle to multiple bouts of contraction-induced injury. Because lengthening (i.e., eccentric) contractions are extremely injurious for dystrophic muscle, it was considered that repeated bouts of such contractions would exacerbate the disease phenotype in mdx mice. Anterior crural muscles (tibialis anterior and extensor digitorum longus) and posterior crural muscles (gastrocnemius, soleus, and plantaris) from mdx mice performed one or five repeated bouts of 100 electrically stimulated eccentric contractions in vivo, and each bout was separated by 10–18 days. Functional recovery from one bout was achieved 7 days after injury, which was in contrast to a group of wild-type mice, which still showed a 25% decrement in electrically stimulated isometric torque at that time point. Across bouts there was no difference in the immediate loss of strength after repeated bouts of eccentric contractions for mdx mice (−70%, P = 0.68). However, after recovery from each bout, dystrophic muscle had greater torque-generating capacity such that isometric torque was increased ∼38% for both anterior and posterior crural muscles at bout 5 compared with bout 1 ( P < 0.001). Moreover, isolated extensor digitorum longus muscles excised from in vivo-tested hindlimbs 14–18 days after bout 5 had greater specific force than contralateral control muscles (12.2 vs. 10.4 N/cm2, P = 0.005) and a 20% greater maximal relaxation rate ( P = 0.049). Additional adaptations due to the multiple bouts of eccentric contractions included rapid recovery and/or sparing of contractile proteins, enhanced parvalbumin expression, and a decrease in fiber size variability. In conclusion, eccentric contractions are injurious to dystrophic skeletal muscle; however, the muscle recovers function rapidly and adapts to repeated bouts of eccentric contractions by improving strength.

scholarly journals Between biology and medicine: perspectives on the use of dendritic cells in anticancer therapy

2017 ◽  
Vol 71 (0) ◽  
pp. 0-0
Author(s):  
Agnieszka Szczygieł ◽  
Elżbieta Pajtasz-Piasecka
Keyword(s):  
Dendritic Cells ◽  
Ex Vivo ◽  
Anticancer Therapy ◽  
Point Of View ◽  
Proper Function ◽  
Innate And Adaptive Immunity ◽  
Factors Affecting ◽  
Antigen Presenting

Dendritic cells (DCs), as a link between innate and adaptive immunity, play a pivotal role in maintaining homeostasis of the immune system. The DC population is characterized by heterogeneity; it consists of many subpopulations which, despite their phenotypic and localization differences, play an essential function – they are professional antigen presenting cells. Due to their role, DCs can be utilized in a new cancer treatment strategy. Their main purpose is to generate an anticancer response leading to the elimination of cancer cells. The tumor microenvironment, abundant in immunosuppressive factors (e.g. IL-10, TGF-β, Arg1, IDO), impairs the proper function of DCs. For this reason, various strategies are necessary for ex vivo preparation of DC-based vaccines and for the support of in vivo DCs to fight against tumors. DC-based vaccines are combined with other forms of immunotherapy (e.g. blockade of immune checkpoint molecules, e.g. PD-1 or CTLA-4) or conventional types of therapies (e.g. chemotherapy). Despite the enormous progress that has been made in anticancer therapy in the past two decades, there are still many unresolved issues regarding the effectiveness of the DCs usage. In this paper we described, in both a mouse and a human subject, a series of DC subpopulations, differentiating in normal conditions or under the influence of cancer microenvironment. We listed factors affecting the quality of the in vivo and ex vivo generations of antitumoral responses, significant from a therapeutic point of view. Moreover, the most important strategies for the use of DCs in anticancer therapies, as well as further developments on this field, have been discussed.

scholarly journals Role of the captured retroviral envelope syncytin-B gene in the fusion of osteoclast and giant cell precursors and in bone resorption, analyzed ex vivo and in vivo in syncytin-B knockout mice

Bone Reports ◽  
2019 ◽  
Vol 11 ◽  
pp. 100214 ◽  
Author(s):  
Amélie E. Coudert ◽  
François Redelsperger ◽  
Yasmine Chabbi-Achengli ◽  
Cécile Vernochet ◽  
Caroline Marty ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Giant Cell ◽  
Knockout Mice ◽  
Ex Vivo

P.321Diaphragm echodensity and function in mdx mice by non-invasive ultrasonography: validation and correlation with in vivo and ex vivo functional readouts

2019 ◽  
Vol 29 ◽  
pp. S160-S161
Author(s):  
P. Mantuano ◽  
A. Mele ◽  
O. Cappellari ◽  
A. Fonzino ◽  
F. Sanarica ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Mdx Mice ◽  
Non Invasive ◽  
And Function

scholarly journals Rhythmic changes in colonic motility are regulated by period genes

2010 ◽  
Vol 298 (2) ◽  
pp. G143-G150 ◽  
Author(s):  
Willemijntje A. Hoogerwerf ◽  
Vahakn B. Shahinian ◽  
Germaine Cornélissen ◽  
Franz Halberg ◽  
Jonathon Bostwick ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Clock Genes ◽  
Ex Vivo ◽  
Colonic Motility ◽  
Biological Clock ◽  
Circular Muscle ◽  
Organ Bath ◽  
Wild Type ◽  
Double Knockout ◽  
Muscle Contractility

Human bowel movements usually occur during the day and seldom during the night, suggesting a role for a biological clock in the regulation of colonic motility. Research has unveiled molecular and physiological mechanisms for biological clock function in the brain; less is known about peripheral rhythmicity. This study aimed to determine whether clock genes such as period 1 ( per1) and period2 ( per2) modulate rhythmic changes in colonic motility. Organ bath studies, intracolonic pressure measurements, and stool studies were used to examine measures of colonic motility in wild-type and per1per2 double-knockout mice. To further examine the mechanism underlying rhythmic changes in circular muscle contractility, additional studies were completed in neuronal nitric oxide synthase (nNOS) knockout mice. Intracolonic pressure changes and stool output in vivo, and colonic circular muscle contractility ex vivo, are rhythmic with greatest activity at the start of night in nocturnal wild-type mice. In contrast, rhythmicity in these measures was absent in per1per2 double-knockout mice. Rhythmicity was also abolished in colonic circular muscle contractility of wild-type mice in the presence of Nω-nitro-l-arginine methyl ester and in nNOS knockout mice. These findings suggest that rhythms in colonic motility are regulated by both clock genes and a nNOS-mediated inhibitory process and suggest a connection between these two mechanisms.

scholarly journals Fluid Structural Analysis of Urine Flow in a Stented Ureter

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
J. Carlos Gómez-Blanco ◽  
F. Javier Martínez-Reina ◽  
Domingo Cruz ◽  
J. Blas Pagador ◽  
Francisco M. Sánchez-Margallo ◽  
...  
Keyword(s):  
Computational Models ◽  
Mechanical Characterization ◽  
Ex Vivo ◽  
Biological Tissues ◽  
Urine Flow ◽  
Computational Environment ◽  
Computational Fluid Dynamics Cfd

Many urologists are currently studying new designs of ureteral stents to improve the quality of their operations and the subsequent recovery of the patient. In order to help during this design process, many computational models have been developed to simulate the behaviour of different biological tissues and provide a realistic computational environment to evaluate the stents. However, due to the high complexity of the involved tissues, they usually introduce simplifications to make these models less computationally demanding. In this study, the interaction between urine flow and a double-J stented ureter with a simplified geometry has been analysed. The Fluid-Structure Interaction (FSI) of urine and the ureteral wall was studied using three models for the solid domain: Mooney-Rivlin, Yeoh, and Ogden. The ureter was assumed to be quasi-incompressible and isotropic. Data obtained in previous studies from ex vivo and in vivo mechanical characterization of different ureters were used to fit the mentioned models. The results show that the interaction between the stented ureter and urine is negligible. Therefore, we can conclude that this type of models does not need to include the FSI and could be solved quite accurately assuming that the ureter is a rigid body and, thus, using the more simple Computational Fluid Dynamics (CFD) approach.

scholarly journals Regenerative capacity of the dystrophic (mdx) diaphragm after induced injury

2004 ◽  
Vol 287 (4) ◽  
pp. R961-R968 ◽  
Author(s):  
Stefan Matecki ◽  
Ghiabe H. Guibinga ◽  
Basil J. Petrof
Keyword(s):  
Connective Tissue ◽  
Isometric Force ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Wild Type ◽  
Regenerative Capacity ◽  
Generating Capacity ◽  
Massive Necrosis ◽  
Characteristic Features

Duchenne muscular dystrophy is characterized by myofiber necrosis, muscle replacement by connective tissue, and crippling weakness. Although the mdx mouse also lacks dystrophin, most muscles show little myofiber loss or functional impairment. An exception is the mdx diaphragm, which is phenotypically similar to the human disease. Here we tested the hypothesis that the mdx diaphragm has a defective regenerative response to necrotic injury, which could account for its severe phenotype. Massive necrosis was induced in mdx and wild-type (C57BL10) mouse diaphragms in vivo by topical application of notexin, which destroys mature myofibers while leaving myogenic precursor satellite cells intact. At 4 h after acute exposure to notexin, >90% of diaphragm myofibers in both wild-type and mdx mice demonstrated pathological sarcolemmal leakiness, and there was a complete loss of isometric force-generating capacity. Both groups of mice showed strong expression of embryonic myosin within the diaphragm at 5 days, which was largely extinguished by 20 days after injury. At 60 days postinjury, wild-type diaphragms exhibited a persistent loss (∼25%) of isometric force-generating capacity, associated with a trend toward increased connective tissue infiltration. In contrast, mdx diaphragms achieved complete functional recovery of force generation to noninjured values, and there was no increase in muscle connective tissue over baseline. These data argue against any loss of intrinsic regenerative capacity within the mdx diaphragm, despite characteristic features of major dystrophic pathology being present. Our findings support the concept that significant latent regenerative capacity resides within dystrophic muscles, which could potentially be exploited for therapeutic purposes.

Factor XII: New life for an old protein

2010 ◽  
Vol 104 (11) ◽  
pp. 915-918 ◽  
Author(s):  
Gretchen LaRusch ◽  
Alvin Schmaier
Keyword(s):  
Cell Growth ◽  
Knockout Mice ◽  
Ex Vivo ◽  
Umbilical Vein ◽  
Antigen Expression ◽  
Mitogen Activated Protein Kinase ◽  
Factor Xii ◽  
Contact Activation ◽  
Urokinase Plasminogen Activator Receptor

SummaryRatnoff and his coworkers recognised that factor XII (XII) stimulates cell growth and activates mitogen-activated protein kinase. We determined the receptor(s) for this function and the consequence of this signalling pathway. Investigations show that the urokinase plasminogen activator receptor serves as the XII binding site on cultured umbilical vein endothelial cells. When XII binds, it stimulates ERK1/2 and Akt S473 phosphorylation. These events are distinct because when cell mTORC2 is absent, XII phosphorylates ERK1/2 but not Akt S473. Zymogen XII is an equal stimulator of signalling as XIIa or inhibitor-treated XIIa. Peptides from uPAR domain 2 block XII binding and ERK1/2 and Akt phosphorylation. Furthermore, antibodies to the integrins β1 and α5 block XII signalling. Likewise, inhibitors to the EGFR block XII-induced phosphorylation events. XII stimulates cell growth and proliferation. XII induces angiogenesis ex vivo in normal aortic sprouts and in vivo in matrigel plugs in normal mice, but not in aorta from uPAR knockout mice or matrigel plugs placed into uPAR-deleted mice. Skin biopsies constitutively or in a wound nine days after injury show reduced CD31 antigen expression in specimens from XII knockout mice compared to wild-type mice. These studies indicate that XII stimulates angiogenesis, a physiologic function independent of contact activation.

scholarly journals Ultrasonography validation for early alteration of diaphragm echodensity and function in the mdx mouse model of Duchenne muscular dystrophy

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245397
Author(s):  
Antonietta Mele ◽  
Paola Mantuano ◽  
Adriano Fonzino ◽  
Francesco Rana ◽  
Roberta Francesca Capogrosso ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Mouse Model ◽  
Ex Vivo ◽  
Eccentric Contraction ◽  
Invasive Technique ◽  
Mdx Mouse ◽  
Early Stages ◽  
Over Time

The mdx mouse model of Duchenne muscular dystrophy is characterized by functional and structural alterations of the diaphragm since early stages of pathology, closely resembling patients’ condition. In recent years, ultrasonography has been proposed as a useful longitudinal non-invasive technique to assess mdx diaphragm dysfunction and evaluate drug efficacy over time. To date, only a few preclinical studies have been conducted. Therefore, an independent validation of this method by different laboratories is needed to increase results reliability and reduce biases. Here, we performed diaphragm ultrasonography in 3- and 6-month-old mdx mice, the preferred age-window for pharmacology studies. The alteration of diaphragm function over time was measured as diaphragm ultrasound movement amplitude. At the same time points, a first-time assessment of diaphragm echodensity was performed, as an experimental index of progressive loss of contractile tissue. A parallel evaluation of other in vivo and ex vivo dystrophy-relevant readouts was carried out. Both 3- and 6-month-old mdx mice showed a significant decrease in diaphragm amplitude compared to wild type (wt) mice. This index was well-correlated either with in vivo running performance or ex vivo isometric tetanic force of isolated diaphragm. In addition, diaphragms from 6-month-old dystrophic mice were also highly susceptible to eccentric contraction ex vivo. Importantly, we disclosed an age-dependent increase in echodensity in mdx mice not observed in wt animals, which was independent from abdominal wall thickness. This was accompanied by a notable increase of pro-fibrotic TGF-β1 levels in the mdx diaphragm and of non-muscle tissue amount in diaphragm sections stained by hematoxylin & eosin. Our findings corroborate the usefulness of diaphragm ultrasonography in preclinical drug studies as a powerful tool to monitor mdx pathology progression since early stages.

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