Contractile Muscle Tissue Research Articles

Expression of intramuscular extracellular matrix proteins in vastus lateralis muscle fibres between atrophic and non-atrophic COPD.

Extracellular matrix (ECM) proteins are the major constituents of the muscle cell micro-environment, imparting instructive signalling, steering cell behaviour and controlling muscle regeneration. ECM remodelling is among the most affected signalling pathways in COPD and aged muscle. As a fraction of COPD patients present muscle atrophy, we questioned whether ECM composition would be altered in patients with peripheral muscle wasting (atrophic COPD) compared to those without muscle wasting (non-atrophic COPD). A set of ECM molecules with known impact on myogenesis were quantified in vastus lateralis muscle biopsies from 29 COPD patients (forced expiratory volume in 1 s 55±12% predicted) using ELISA and real-time PCR. COPD patients were grouped to atrophic or non-atrophic based on fat-free mass index (<17 or ≥17 kg·m-2). Atrophic COPD patients presented a lower average vastus lateralis muscle fibre cross-sectional area (3872±258 μm2) compared to non-atrophic COPD (4509±198 μm2). Gene expression of ECM molecules was found significantly lower in atrophic COPD compared to non-atrophic COPD for collagen type I alpha 1 chain (COL1A1), fibronectin (FN1), tenascin C (TNC) and biglycan (BGN). In terms of protein levels, there were no significant differences between the two COPD cohorts for any of the ECM molecules tested. Although atrophic COPD presented decreased contractile muscle tissue, the differences in ECM mRNA expression between atrophic and non-atrophic COPD were not translated at the protein level, potentially indicating an accumulation of long-lived ECM proteins and dysregulated proteostasis, as is typically observed during deconditioning and ageing.

Evaluation of rehabilitation exercise effects by using gradation-based skeletal muscle echo intensity in older individuals: a one-group before-and-after trial study

BackgroundHigher muscle echo intensity (EI) reflects higher content of fat and/or connective tissue within skeletal muscle, eventually inducing lower muscle strength, physical dysfunction, and metabolic impairment. Continuous exercise decreases muscle EI in older individuals; however, it is not well understood how several months’ rehabilitation exercise affects gradation-based EI. The purpose of this study was to investigate the effects of 6 months of rehabilitation exercise on gradation-based higher and lower EI in older men and women.MethodsTwenty-seven men and women (7 men, 20 women; age, 75.6 ± 6.4 years; height, 154.3 ± 8.5 cm; weight, 55.8 ± 9.7 kg) participated in this study. This study was a one-group before-and-after trial. They needed long-term care for activities of daily living. They performed rehabilitation exercises consisting of resistance exercises using a hydraulic resistance machine, stretching, and aerobic exercises using a recumbent bicycle once or twice a week for 6 months. B-mode ultrasonographic transverse image was taken from thigh muscles, e.g., rectus femoris, vastus lateralis, and biceps femoris. We calculated gradation-based cross-sectional area (CSA) from thigh muscles by dividing 256 greyscale level to 10 different components levels (e.g., 0–24, 25–49, 50–74, …, 200–224 and 225–249 a.u.).ResultsLowest EI (e.g., 0–24 a.u.) CSA of thigh muscle was significantly increased after the exercise (0.3 ± 0.3 to 1.0 ± 0.8 cm2; P < 0.05). Middle to higher EI (e.g., 50–74, 75–99, 100–124, 125–149, 150–174, 175–199 and 200–224 a.u.) CSAs were significantly decreased from 23.0 to 68.7% after the exercise (P < 0.05).ConclusionsSeveral months’ rehabilitation exercise affected both lower and higher EI in older men and women. This result suggests that rehabilitation exercise changes muscle composition by increasing contractile muscle tissue and decreasing fat and connective tissues.

Six Months’ Rehabilitation Exercise Affects Lower And Higher Muscle Echo Intensity In Elderly Individuals

Muscle echo intensity (EI) reflects the content of fat and connective tissue within a skeletal muscle. Muscle EI becomes higher with aging and/or inactivity caused by increase of fat and connective tissues, and eventually it may induce lower muscle strength. We have previously reported that the EI improved after a few months’ resistance and endurance training in elderly individuals. This result would be led by decreasing of fat and connective tissues (i.e. decrease higher EI area) and/or increasing of contractive muscle tissue (i.e. increase lower EI area); however, it is not well understood how the muscle EI change by several months rehabilitation exercise. PURPOSE: The purpose of this study was to investigate the effects of 6 months rehabilitation exercise on gradation-based muscle EI area in elderly men and women. METHODS: Five men and women (2 men and 3 women; age, 75 ± 5 years; height, 156 ± 4 cm; weight, 53 ± 9 kg) participated in this study. They performed rehabilitation exercises consisting of resistance exercises, stretching, and aerobic exercises once or twice a week for 6 months because they needed long-term care during a part of daily living. B-mode ultrasonographic transverse image was taken from rectus femoris. To obtain EI, region of interest (ROI) was set on rectus femoris as large as possible exclude fascia. Average muscle EI, which was shown by 256 gray scale level, was measured within a ROI. We also calculated cross-sectional area based on 256 grey scale level divided into 6 different components (e.g. 0-49, 50-99, 100-149, 150-199, 200-249 and 250-256 a.u.). RESULTS: Average EI decreased after six months exercise (72.70 ± 7.55 vs. 53.50 ± 15.51 a.u., p < 0.05). Lower ranged EI area was significantly increased after the exercise (0-49; 1.13 ± 0.88 vs. 1.93 ± 1.00 cm2, p < 0.05). Middle to higher ranged EI areas were significantly decreased after the exercise (100-149; 0.44 ± 0.20 vs. 0.24 ± 0.15 cm2, 150-199; 0.08 ± 0.05 vs. 0.03 ± 0.04 cm2, p < 0.05). CONCLUSIONS: Six months rehabilitation exercise improved muscle EI in elderly men and women. This result might be induced by decreasing fat and connective tissues and increasing contractile muscle tissue.

I.6Arthrogryposis multiplex congenita; new genes & old acquaintances

Arthrogryposis multiplex congenita (AMC) is a multi-facetted disease that is characterized by congenital contractures in two or more body regions, which might or might not be accompanied by additional symptoms, being termed "syndromic" or "isolated" arthrogryposis. The disease is further clinically divided into "proximal" and "distal" arthrogryposis, depending on whether large or smaller distal joints of hands and feet are predominantly affected. AMC results from an overall lack of fetal movement (fetal akinesia), which in turn might have a multitude of etiologies with presently more than 120 having a genetic underpinning. Genetic defects mainly revolve around the development and maintenance of the motor unit and the reflex arch. Mutations may affect proteins with a role in the development of connective and contractile muscle tissue, in the biogenesis of the neuromuscular endplate, and in neuronal myelination. Other proteins may be involved in neuronal pathfinding, signaling, and cellular transport mechanisms or participate in the local or central control of muscle tension. This lecture will give an overview over the multiple etiologies and will try a classification on genetic and clinical grounds, which could support the diagnosing physicians to find the correct diagnosis in their patients. Finally, we will present a novel genetic defect that causes spontaneously regressing AMC associated with dilated cardiomyopathy.

A Micro Peristaltic Pump Using an Optically Controllable Bioactuator

Abstract Peristalsis is widely seen in nature, as this pumping action is important in digestive systems for conveying sustenance to every corner of the body. In this paper, we propose a muscle-powered tubular micro pump that provides peristaltic transport. We utilized Drosophila melanogaster larvae that express channelrhodopsin-2 (ChR2) on the cell membrane of skeletal muscles to obtain light-responsive muscle tissues. The larvae were forced to contract with blue light stimulation. While changing the speed of the propagating light stimulation, we observed displacement on the surface of the contractile muscle tissues. We obtained peristaltic pumps from the larvae by dissecting them into tubular structures. The average inner diameter of the tubular structures was about 400 μm and the average outer diameter was about 750 μm. Contractions of this tubular structure could be controlled with the same blue light stimulation. To make the inner flow visible, we placed microbeads into the peristaltic pump, and thus determined that the pump could transport microbeads at a speed of 120 μm·s−1.

An MRI Investigating of the Lower Limb Musculature in Patients with Chronic Inflammatory Demyelinating Polyneuropathy

IntroductionChronic inflammatory demyelinating polyneuropathy (CIDP) is an autoimmune disease characterized by peripheral nerve demyelination. Patients present with sensory and motor deficits, including symmetrical diffused muscle weakness especially in distal muscles. Studies have focused mainly on the neuropathic aspects of CIDP and its involvement in paresis, showing lesions in various nerve plexes including the lumbar nerve roots. Weakness in patients with CIDP has been reported predominantly in the distal musculature. However, changes in muscle quality and quantity have not been explored systematically throughout the lower limb. Thus, the purpose of this study was to use magnetic resonance imaging (MRI) to compare anatomical differences in the quadriceps femoris and triceps surae muscle complexes in a group of patients with CIDP and control subjects.MethodsTo date, five patients with CIDP (3 males, 2 females) and six healthy controls (4 males, 2 females) and matched on age (45 to 68 years) have been investigated. On separate days, MRI (T1) of the lower limb musculature was acquired via serial axial plane scans in a 3.0‐Tesla magnet with a 3D FLASH sequence: (0.9mm slice thickness with slice separation of 1mm ranging from 280 to 400 slices). All MRI scans were analyzed using OsiriX imaging processing software. On a single thigh slice (two‐thirds distance proximal to distal) and leg slice (one‐third distance proximal to distal) total muscle area was computed for the quadriceps femoris (rectus femoris, vastus lateralis, vastus intermedius, vastus medialis), and the triceps surae (soleus, lateral and medial gastrocnemii) groups, respectively. Contractile muscle area (fat and connective tissue removed) for each muscle group was determined using a pixel threshold intensity algorithm. Percentage of fat infiltration was computed by subtracting contractile muscle area from total muscle area.ResultsPatients with CIDP had ~24% less total anatomical cross‐sectional area (ACSA) in both quadriceps femoris and the triceps surae compared to controls. Patients with CIDP, however had ~35% less contractile muscle tissue in the quadriceps femoris whereas the triceps surae were ~51% lower in contractile tissue, compared with controls. The ACSA of the triceps surae of CIDP patients consisted of ~40% fat whereas the quadriceps femoris ACSA had ~16% fat infiltration. Furthermore, the control group's ACSA consisted of ~9% and 5% fat, respectively in the triceps surae and quadriceps.ConclusionPatients with CIDP have less total thigh ACSA with increased intramuscular fat infiltration compared with controls indicative of lower muscle quality in CIDP. Fatty infiltration in the CIDP group are greater in the anterior thigh compared to posterior leg. This indicates that in addition to lower muscle quantity and quality in CIDP, distal musculature seems to be affected to a greater degree by the nerve impairments noted in CIDP.Support or Funding InformationSupported by NSERCThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Three-dimensional contractile muscle tissue consisting of human skeletal myocyte cell line

This paper describes a method to construct three-dimensional (3D) contractile human skeletal muscle tissues from a cell line. The 3D tissue was fabricated as a fiber-based structure and cultured for two weeks under tension by anchoring its both ends. While myotubes from the immortalized human skeletal myocytes used in this study never contracted in the conventional two-dimensional (2D) monolayer culture, myotubes in the 3D tissue showed spontaneous contraction at a high frequency and also reacted to the electrical stimulation. Immunofluorescence revealed that the myotubes in the 3D tissues had sarcomeres and expressed ryanodine receptor (RyR) and sarco/endoplasmic reticulum Ca2+-ATPase (SERCA). In addition, intracellular calcium oscillations in the myotubes in the 3D tissue were observed. These results indicated that the 3D culture enabled the myocyte cell line to reach a more highly matured state compared to 2D culture. Since contraction is the most significant feature of skeletal muscle, we believe that our 3D human muscle tissue with the contractile ability would be a useful tool for both basic biology research and drug discovery as one of the muscle-on-chips.

Integrated Heart—Coupling multiscale and multiphysics models for the simulation of the cardiac function

Mathematical modeling of the human heart and its function can expand our understanding of various cardiac diseases, which remain the most common cause of death in the developed world. Like other physiological systems, the heart can be understood as a complex multiscale system involving interacting phenomena at the molecular, cellular, tissue, and organ levels. This article addresses the numerical modeling of many aspects of heart function, including the interaction of the cardiac electrophysiology system with contractile muscle tissue, the sub-cellular activation–contraction mechanisms, as well as the hemodynamics inside the heart chambers. Resolution of each of these sub-systems requires separate mathematical analysis and specially developed numerical algorithms, which we review in detail. By using specific sub-systems as examples, we also look at systemic stability, and explain for example how physiological concepts such as microscopic force generation in cardiac muscle cells, translate to coupled systems of differential equations, and how their stability properties influence the choice of numerical coupling algorithms. Several numerical examples illustrate three fundamental challenges of developing multiphysics and multiscale numerical models for simulating heart function, namely: (i) the correct upscaling from single-cell models to the entire cardiac muscle, (ii) the proper coupling of electrophysiology and tissue mechanics to simulate electromechanical feedback, and (iii) the stable simulation of ventricular hemodynamics during rapid valve opening and closure.

Characterization of the mechanical properties of HL-1 cardiomyocytes with high throughput magnetic tweezers

We characterized the mechanical properties of cardiomyocyte-like HL-1 cells using our recently developed multi-pole magnetic tweezers. With the optimized design, both high force and high throughput are achieved at the same time. Force up to 100 pN can be applied on a 1 μm diameter superparamagnetic bead in a workspace with 60 μm radius, which is encircled symmetrically by 3 sharp magnetic tips. By adjusting the coil currents, both the strength and direction of force can be controlled. The result shows that both viscosity and shear elastic modulus of HL-1 cells exhibit an approximately log-normal distribution. The cells became stiffer as they matured, consistent with a transition from proliferating cells to contractile muscle tissue. Moreover, the mechanical properties of HL-1 cells show high heterogeneity, which agrees well with their physiological structure.

Oxidative Stress in Muscle Growth and Adaptation to Physical Exercise

In a few last decades oxidative stress detected in a variety of physiological processeswhere reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a central role. Theyare directly involved in oxidation of proteins, lipids and nucleic acids. In certain concentrationsthey are necessary for cell division, proliferation and apoptosis. Contractile muscle tissue at aerobicconditions form high ROS flow that may modulate a variety of cell functions, for exampleproliferation. However, slight increase in ROS level provide hormetic effect which may participatein adaptation to heavy weight training resulted in hypertrophy and proliferation of skeletal musclefibers. This review will discuss ROS types, sites of generation, strategies to increase forceproduction and achieve skeletal muscle hypertrophy

MALDI imaging mass spectrometry: discrimination of pathophysiological regions in traumatized skeletal muscle by characteristic peptide signatures.

Due to formation of fibrosis and the loss of contractile muscle tissue, severe muscle injuries often result in insufficient healing marked by a significant reduction of muscle force and motor activity. Our previous studies demonstrated that the local transplantation of mesenchymal stromal cells into an injured skeletal muscle of the rat improves the functional outcome of the healing process. Since, due to the lack of sufficient markers, the accurate discrimination of pathophysiological regions in injured skeletal muscle is inadequate, underlying mechanisms of the beneficial effects of mesenchymal stromal cell transplantation on primary trauma and trauma adjacent muscle area remain elusive. For discrimination of these pathophysiological regions, formalin-fixed injured skeletal muscle tissue was analyzed by MALDI imaging MS. By using two computational evaluation strategies, a supervised approach (ClinProTools) and unsupervised segmentation (SCiLS Lab), characteristic m/z species could be assigned to primary trauma and trauma adjacent muscle regions. Using "bottom-up" MS for protein identification and validation of results by immunohistochemistry, we could identify two proteins, skeletal muscle alpha actin and carbonic anhydrase III, which discriminate between the secondary damage on adjacent tissue and the primary traumatized muscle area. Our results underscore the high potential of MALDI imaging MS to describe the spatial characteristics of pathophysiological changes in muscle.

Chagasic megacolon: enteric neurons and related structures.

Megacolon, the irreversible dilation of a colonic segment, is a structural sign associated with various gastrointestinal disorders. In its hereditary, secondary form (e.g. in Hirschsprung’s disease), dilation occurs in an originally healthy colonic segment due to an anally located, aganglionic zone. In contrast, in chronic Chagas’ disease, the dilated segment itself displays pathohistological changes, and the earliest and most prominent being found was massive loss of myenteric neurons. This neuron loss was partial and selective, i.e. some neurons containing neuronal nitric oxide synthase and/or vasoactive intestinal peptide (VIP) were spared from neuron death. This disproportionate survival of inhibitory neurons, however, did not completely correlate with the calibre change along the surgically removed, megacolonic segments. A better correlation was observed as to potentially contractile muscle tissue elements and the interstitial cells of Cajal. Therefore, the decreased densities of α-smooth muscle actin- and c-kit-immunoreactive profiles were estimated along resected megacolonic segments. Their lowest values were observed in the megacolonic zones itself, whereas less pronounced decreases were found in the non-dilated, transitional zones (oral and anal to dilation). In contrast to the myenteric plexus, the submucosal plexus displayed only a moderate neuron loss. Neurons co-immunoreactive for VIP and calretinin survived disproportionately. As a consequence, these neurons may have contributed to maintain the epithelial barrier and allowed the chagasic patients to survive for decades, despite their severe disturbance of colonic motility. Due to its neuroprotective and neuroeffectory functions, VIP may play a key role in the development and duration of chagasic megacolon.

258 CULTURING HUMAN MUSCLE PRECURSOR CELLS (MPCS) WITH XENO-FREE MEDIUM: GMP AND CLINICAL APPLICATION PREPARATION

You have accessJournal of UrologyStem Cell Research1 Apr 2013258 CULTURING HUMAN MUSCLE PRECURSOR CELLS (MPCS) WITH XENO-FREE MEDIUM: GMP AND CLINICAL APPLICATION PREPARATION Fahd Azzabi, Souzan Salemi, Ria Tauscher, Katharina Schallmoser, Dirk Strunk, Tullio Sulser, and Daniel Eberli Fahd AzzabiFahd Azzabi Zurich, Switzerland More articles by this author , Souzan SalemiSouzan Salemi Zurich, Switzerland More articles by this author , Ria TauscherRia Tauscher Zurich, Switzerland More articles by this author , Katharina SchallmoserKatharina Schallmoser Graz, Austria More articles by this author , Dirk StrunkDirk Strunk Graz, Austria More articles by this author , Tullio SulserTullio Sulser Zurich, Switzerland More articles by this author , and Daniel EberliDaniel Eberli Zurich, Switzerland More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.1640AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Autologous cell injections are promising therapies for many diseases including urinary incontinence, where sphincter muscle damage provokes urine leakage and significantly reduces life quality. Several animal models showed that injection of precursor or stem cells leaded to the regeneration of sphincter muscle tissue. Currently, all types of cell used in these preclinical and clinical studies are expanded in xenogenic media containing fetal bovine serum (FBS). However, before precursors or stem cells can be applied clinically it is mandatory to reduce the potential immunogenic reaction and infection risk by removing any xenogenic contaminants which is required by the new regulations and good manufacturing practice for cell therapies. METHODS In this research human MPCs were expanded in xeno-free medium using pooled human platelet lysates (pHPL) or pooled human Serum (HS). We assessed the expansion potential, the differentiation by FACS, western blot and the fibre formation in vitro. Further, we assed the in vivo muscle tissue formation after injection, specific muscle expression by western blot and contractility by organ bath. Cells grown in standard FBS medium served as controls. RESULTS Our results clearly demonstrate that HS is no substitute for FBS: MPCs isolated from human biopsies were not able to expand. Using pHPL we were able to expand the MPCs while maintaining the myo-phenotype as demonstrated by FACS, WB and IHC for MyoD, desmin and MHC. Expanded MPCs gave rise to contractile muscle tissue after injection in vivo, comparable to tissues grown using cells expanded in FBS. CONCLUSIONS In conclusion, our results show that pHPL is a suitable substitute for FBS allowing the MPCs to form contractile muscle after injection. pHPL may be used to facilitate the preparation for clinical applications. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e106 Peer Review Report Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Fahd Azzabi Zurich, Switzerland More articles by this author Souzan Salemi Zurich, Switzerland More articles by this author Ria Tauscher Zurich, Switzerland More articles by this author Katharina Schallmoser Graz, Austria More articles by this author Dirk Strunk Graz, Austria More articles by this author Tullio Sulser Zurich, Switzerland More articles by this author Daniel Eberli Zurich, Switzerland More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Fine-tuning of substrate architecture and surface chemistry promotes muscle tissue development

Tissue engineering has been increasingly brought to the scientific spotlight in response to the tremendous demand for regeneration, restoration or substitution of skeletal or cardiac muscle after traumatic injury, tumour ablation or myocardial infarction. In vitro generation of a highly organized and contractile muscle tissue, however, crucially depends on an appropriate design of the cell culture substrate. The present work evaluated the impact of substrate properties, in particular morphology, chemical surface composition and mechanical properties, on muscle cell fate. To this end, aligned and randomly oriented micron (3.3±0.8μm) or nano (237±98nm) scaled fibrous poly(ε-caprolactone) non-wovens were processed by electrospinning. A nanometer-thick oxygen functional hydrocarbon coating was deposited by a radio frequency plasma process. C2C12 muscle cells were grown on pure and as-functionalized substrates and analysed for viability, proliferation, spatial orientation, differentiation and contractility. Cell orientation has been shown to depend strongly on substrate architecture, being most pronounced on micron-scaled parallel-oriented fibres. Oxygen functional hydrocarbons, representing stable, non-immunogenic surface groups, were identified as strong triggers for myotube differentiation. Accordingly, the highest myotube density (28±15% of total substrate area), sarcomeric striation and contractility were found on plasma-coated substrates. The current study highlights the manifold material characteristics to be addressed during the substrate design process and provides insight into processes to improve bio-interfaces.

Muscle co-contraction modulates damping and joint stability in a three-link biomechanical limb.

Computational models of neuromotor control require forward models of limb movement that can replicate the natural relationships between muscle activation and joint dynamics without the burdens of excessive anatomical detail. We present a model of a three-link biomechanical limb that emphasizes the dynamics of limb movement within a simplified two-dimensional framework. Muscle co-contraction effects were incorporated into the model by flanking each joint with a pair of antagonist muscles that may be activated independently. Muscle co-contraction is known to alter the damping and stiffness of limb joints without altering net joint torque. Idealized muscle actuators were implemented using the Voigt muscle model which incorporates the parallel elasticity of muscle and tendon but omits series elasticity. The natural force-length-velocity relationships of contractile muscle tissue were incorporated into the actuators using ideal mathematical forms. Numerical stability analysis confirmed that co-contraction of these simplified actuators increased damping in the biomechanical limb consistent with observations of human motor control. Dynamic changes in joint stiffness were excluded by the omission of series elasticity. The analysis also revealed the unexpected finding that distinct stable (bistable) equilibrium positions can co-exist under identical levels of muscle co-contraction. We map the conditions under which bistability arises and prove analytically that monostability (equifinality) is guaranteed when the antagonist muscles are identical. Lastly we verify these analytic findings in the full biomechanical limb model.

173 IMPACT OF PATIENT AGE OR GENDER ON BIOENGINEERING OF FUNCTIONAL MUSCLE TISSUE USING MUSCLE PRECURSOR CELLS

You have accessJournal of UrologyStem Cell Research1 Apr 2011173 IMPACT OF PATIENT AGE OR GENDER ON BIOENGINEERING OF FUNCTIONAL MUSCLE TISSUE USING MUSCLE PRECURSOR CELLS Meline Stölting, Lukas Hefermehl, mathias Tremp, Fahd Azzabi, Tullio Sulser, and Daniel Eberli Meline StöltingMeline Stölting Zürich, Switzerland More articles by this author , Lukas HefermehlLukas Hefermehl Zürich, Switzerland More articles by this author , mathias Trempmathias Tremp Zürich, Switzerland More articles by this author , Fahd AzzabiFahd Azzabi Zürich, Switzerland More articles by this author , Tullio SulserTullio Sulser Zürich, Switzerland More articles by this author , and Daniel EberliDaniel Eberli Zürich, Switzerland More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.242AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Muscle bioengineering using Muscle Progenitor Cells (MPCs) is proposed as a treatment option for various conditions, including stress urinary incontinence (SUI). Urinary Incontinence is a common condition in the elderly defined as an involuntary loss of urine leading to social or hygienic problems1. It affects around half of the female population over 45 years2 and 17% of men after 70 years2. Current literature has demonstrated limitations regarding cell growth and muscle formation3. The goal of this research was to assess the effect of gender and age on the ability of human MPCs to form functional bioengineered muscle. METHODS Upon ethical approval human MPCs were harvested from the rectus abdominalis of 15 males and 15 female patients undergoing abdominal surgery of various ages [23–82y]. Growth curve standards were drawn and muscle phenotype was analyzed by FACS analyses, fiber formation assay and immunohistochemistry. MPCs were injected with a collagen carrier in subcutaneous space of nude mice. After retrieval, histology and organ bath of bioengineered muscle were performed. RESULTS Samples isolated from female patients tended to grow faster than male (p=0.0672) and produce better contraction upon electrical stimulation (p=0.01937), while the male samples had, upon induction, an increased differentiation ratio. While MPCs of all ages were able to form muscle, there was a step decline in contractile response to electrical stimulation in samples from patients above 75 years. However, we were able to confirm the myogenic phenotype (IHC and FACS), a great expansion potential and fiber formation in all ages and both gender. CONCLUSIONS Our results suggest that human MPCs can be successfully isolated and grown from patients of all ages and gender. Despite the differences presented all samples formed muscle tissue in vivo. However, we found a significant limitation for the engineering of contractile muscle tissue if the donor was older then 75 years. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e72 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Meline Stölting Zürich, Switzerland More articles by this author Lukas Hefermehl Zürich, Switzerland More articles by this author mathias Tremp Zürich, Switzerland More articles by this author Fahd Azzabi Zürich, Switzerland More articles by this author Tullio Sulser Zürich, Switzerland More articles by this author Daniel Eberli Zürich, Switzerland More articles by this author Expand All Advertisement Advertisement Loading ...

Integration of multiple cell-matrix interactions into alginate scaffolds for promoting cardiac tissue regeneration

Cardiac tissue engineering aims to repair damaged myocardial tissues by applying heart patches created in vitro. Herein, we explored the possible role of a combination of two matrix-attached peptides, the adhesion peptide G 4RGDY and heparin-binding peptide G 4SPPRRARVTY (HBP) in cardiac tissue regeneration. Neonatal rat cardiac cells were seeded into unmodified, single peptide or double peptide-attached alginate scaffolds, all having the same physical features of porosity, hydrogel forming and matrix stiffness. The cardiac tissue developed in the HBP/RGD-attached scaffolds revealed the best features of a functional muscle tissue, as judged by all studied parameters, i.e., immunostaining of cardiac cell markers, histology, western blot of protein expressions and metabolic activity. By day 7, well-developed myocardial fibers were observed in these cell constructs. At 14 days the HBP/RGD-attached constructs presented an isotropic myofiber arrangement, while no such arrangement was seen in the other constructs. The expression levels of α-actinin, N-cadherin and Connexin-43, showing preservation and an increase in Connexin-43 expression (Cx-43) with time, further supported the formation a contractile muscle tissue in the HBP/RGD-attached scaffolds. Collectively, the attachment of combinatorial peptides representing different signaling in ECM-cell interactions proved to play a key role, contributing to the formation of a functional cardiac muscle tissue, in vitro.

T.P.4.04 Automated drug screening with contractile muscle tissue engineered from dystrophic myoblasts

T.P.4.04 Automated drug screening with contractile muscle tissue engineered from dystrophic myoblasts

Automated drug screening with contractile muscle tissue engineered from dystrophic myoblasts

Identification of factors that improve muscle function in boys with Duchenne muscular dystrophy (DMD) could lead to an improved quality of life. To establish a functional in vitro assay for muscle strength, mdx murine myoblasts, the genetic homologue of DMD, were tissue engineered in 96-microwell plates into 3-dimensional muscle constructs with parallel arrays of striated muscle fibers. When electrically stimulated, they generated tetanic forces measured with an automated motion tracking system. Thirty-one compounds of interest as potential treatments for patients with DMD were tested at 3 to 6 concentrations. Eleven of the compounds (insulin-like growth factor-1, creatine, beta-hydroxy-beta-methylbutyrate, trichostatin A, lisinopril, and 6 from the glucocorticoid family) significantly increased tetanic force relative to placebo-treated controls. The glucocorticoids methylprednisolone, deflazacort, and prednisone increased tetanic forces at low doses (EC(50) of 6, 19, and 56 nM, respectively), indicating a direct muscle mechanism by which they may be benefitting DMD patients. The tetanic force assay also identified beneficial compound interactions (arginine plus deflazacort and prednisone plus creatine) as well as deleterious interactions (prednisone plus creatine inhibited by pentoxifylline) of combinatorial therapies taken by some DMD patients. Since mdx muscle in vivo and DMD patients respond in a similar manner to many of these compounds, the in vitro assay will be a useful tool for the rapid identification of new potential treatments for muscle weakness in DMD and other muscle disorders.

From scrawny to brawny: the quest for neomusculogenesis; smart surfaces and scaffolds for muscle tissue engineering

The successful generation of functional muscle tissues requires both an in-depth knowledge of muscle tissue physiology and advanced engineering practices. The inherent contractile functionality of muscle is a result of its high-level cellular and matrix organization over a multitude of length scales. While there have been many attempts to produce artificial muscle, a method to fabricate a highly organized construct, comprised of multiple cell types and capable of delivering contractile strengths similar to that of native smooth, skeletal or cardiac muscle has remained elusive. This is largely due to a lack of control over phenotype and spatial organization of cells. This paper covers state-of-the-art approaches to generating both 2D and 3D substrates that provide some form of higher level organization or multiple biochemical, mechanical or electrical cues to cells in order to successfully manipulate their behavior, in a manner that is conducive to the production of contractile muscle tissue. These so-called ‘smart surfaces’ and ‘smart scaffolds’ represent vital steps towards surface-engineered substrates for the engineering of muscle tissues, showing confidently that cellular behavior can be effectively and reproducibly manipulated through the design of the physical, chemical and electrical properties of the substrates on which cells are grown. However, many challenges remain to be overcome prior to reaching the ultimate goal of fully functional 3D vascularized engineered muscle.