scholarly journals Neuromuscular Development and Disease: Learning From in vitro and in vivo Models

2021 ◽  
Vol 9 ◽  
Author(s):  
Zachary Fralish ◽  
Ethan M. Lotz ◽  
Taylor Chavez ◽  
Alastair Khodabukus ◽  
Nenad Bursac
Keyword(s):  
Skeletal Muscle ◽  
Cell Culture ◽  
Animal Models ◽  
Schwann Cells ◽  
Motor Neurons ◽  
Small Animal ◽  
In Vivo Models ◽  
Small Animal Models

The neuromuscular junction (NMJ) is a specialized cholinergic synaptic interface between a motor neuron and a skeletal muscle fiber that translates presynaptic electrical impulses into motor function. NMJ formation and maintenance require tightly regulated signaling and cellular communication among motor neurons, myogenic cells, and Schwann cells. Neuromuscular diseases (NMDs) can result in loss of NMJ function and motor input leading to paralysis or even death. Although small animal models have been instrumental in advancing our understanding of the NMJ structure and function, the complexities of studying this multi-tissue system in vivo and poor clinical outcomes of candidate therapies developed in small animal models has driven the need for in vitro models of functional human NMJ to complement animal studies. In this review, we discuss prevailing models of NMDs and highlight the current progress and ongoing challenges in developing human iPSC-derived (hiPSC) 3D cell culture models of functional NMJs. We first review in vivo development of motor neurons, skeletal muscle, Schwann cells, and the NMJ alongside current methods for directing the differentiation of relevant cell types from hiPSCs. We further compare the efficacy of modeling NMDs in animals and human cell culture systems in the context of five NMDs: amyotrophic lateral sclerosis, myasthenia gravis, Duchenne muscular dystrophy, myotonic dystrophy, and Pompe disease. Finally, we discuss further work necessary for hiPSC-derived NMJ models to function as effective personalized NMD platforms.

scholarly journals Tissue-Engineered Skeletal Muscle Models to Study Muscle Function, Plasticity, and Disease

2021 ◽  
Vol 12 ◽  
Author(s):  
Alastair Khodabukus
Keyword(s):  
Skeletal Muscle ◽  
Animal Models ◽  
Muscle Fiber ◽  
Muscle Function ◽  
Fiber Type ◽  
Small Animal ◽  
Muscle Fiber Type ◽  
Small Animal Models ◽  
Muscle Models

Skeletal muscle possesses remarkable plasticity that permits functional adaptations to a wide range of signals such as motor input, exercise, and disease. Small animal models have been pivotal in elucidating the molecular mechanisms regulating skeletal muscle adaptation and plasticity. However, these small animal models fail to accurately model human muscle disease resulting in poor clinical success of therapies. Here, we review the potential of in vitro three-dimensional tissue-engineered skeletal muscle models to study muscle function, plasticity, and disease. First, we discuss the generation and function of in vitro skeletal muscle models. We then discuss the genetic, neural, and hormonal factors regulating skeletal muscle fiber-type in vivo and the ability of current in vitro models to study muscle fiber-type regulation. We also evaluate the potential of these systems to be utilized in a patient-specific manner to accurately model and gain novel insights into diseases such as Duchenne muscular dystrophy (DMD) and volumetric muscle loss. We conclude with a discussion on future developments required for tissue-engineered skeletal muscle models to become more mature, biomimetic, and widely utilized for studying muscle physiology, disease, and clinical use.

Abstract 228: Alterations of Cardiac Morphology and Function Caused by Cardio-Thoracic Surgery in Small Animal Models of Heart Disease

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Peter Nordbeck ◽  
Leoni Bönhof ◽  
Karl-Heinz Hiller ◽  
Sabine Voll ◽  
Paula Arias ◽  
...  
Keyword(s):  
Body Weight ◽  
Heart Disease ◽  
Animal Models ◽  
Right Ventricular ◽  
Small Animal ◽  
Cardiac Morphology ◽  
Small Animal Models ◽  
And Function

Background: Surgical procedures in small animal models of heart disease, such as artificial ligation of the coronary arteries for experimental myocardial infarction, can evoke alterations in cardiac morphology and function. Such alterations might induce artificial early or long term effects in vivo that might account for a significant bias in basic cardiovascular research, and, therefore, could potentially question the meaning of respective studies in small animal models of heart disease. Methods: Female Wistar rats were matched for weight and distributed to sham left coronary artery ligation or untreated control. Cardiac parameters were then investigated in vivo by high-field MRI over time after the surgical procedure, determining left and right ventricular morphology and function. Additionally, the time course of several metabolic and inflammatory blood parameters was determined. Results: Rats after sham surgery showed a lower body weight for up to 8 weeks after the intervention compared to healthy controls. Left and right ventricular morphology and function were not different in absolute measures in both groups 1 week after surgery. However, there was a confined difference in several cardiac parameters normalized to the body weight (bw), such as myocardial mass (2.19±0.30/0.83±0.13 vs. 1.85±0.22/0.70±0.07 mg left/right per g bw, p<0.05), or enddiastolic ventricular volume (1.31±0.36/1.21±0.31 vs. 1.14±0.20/1.07±0.17 µl left/right per g bw, p<0.05). Vice versa, after 8 weeks, cardiac masses, volumes, and output showed a trend for lower values in the sham operated rats compared to the controls in absolute measures (782.2±57.2/260.2±33.2 vs. 805.9±84.8/310.4±48.5 mg, p<0.05 for left/right ventricular mass), but not normalized to body weight. Matching these findings, blood testing revealed prolonged metabolic and inflammatory changes after surgery not related to cardiac disease. Conclusion: There is a small distinct impact of cardio-thoracic surgical procedures on the global integrity of the organism, which in the long term also includes circumscribed repercussions on cardiac morphology and function. This impact has to be considered when analyzing data from respective studies and transferring the findings to conditions in patients.

scholarly journals Molecular Targets of Androgen Signaling that Characterize Skeletal Muscle Recovery and Regeneration

2015 ◽  
Vol 13 (1) ◽  
pp. nrs.13005 ◽  
Author(s):  
James G. MacKrell ◽  
Benjamin C. Yaden ◽  
Heather Bullock ◽  
Keyue Chen ◽  
Pamela Shetler ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Molecular Targets ◽  
Gene Signature ◽  
Muscle Recovery ◽  
In Vivo Models ◽  
Adult Skeletal Muscle ◽  
Injury Model ◽  
Androgen Regulation

The high regenerative capacity of adult skeletal muscle relies on a self-renewing depot of adult stem cells, termed muscle satellite cells (MSCs). Androgens, known mediators of overall body composition and specifically skeletal muscle mass, have been shown to regulate MSCs. The possible overlapping function of androgen regulation of muscle growth and MSC activation has not been carefully investigated with regards to muscle regeneration. Therefore, the aim of this study was to examine coinciding androgen-mediated genetic changes in an in vitro MSC model and clinically relevant in vivo models. A gene signature was established via microarray analysis for androgen-mediated MSC engagement and highlighted several markers including follistatin (FST), IGF-1, C-X-C chemokine receptor 4 (CXCR4), hepatocyte growth factor (HGF) and glucocorticoid receptor (GR/Nr3c1). In an in vivo muscle atrophy model, androgen re-supplementation significantly increased muscle size and expression of IGF-1, FST, and HGF, while significantly decreasing expression of GR. Biphasic gene expression profiles over the 7-day re-supplementation period identifed temporal androgen regulation of molecular targets involved in satellite cell engagement into myogenesis. In a muscle injury model, removal of androgens resulted in delayed muscle recovery and regeneration. Modifications in the androgen signaling gene signature, along with reduced Pax7 and MyoD expression, suggested that limited MSC activation and increased inflammation contributed to the delayed regeneration. However, enhanced MSC activation in the androgen-deplete mouse injury model was driven by an androgen receptor (AR) agonist. These results provide novel in vitro and in vivo evidence describing molecular targets of androgen signaling, while also increasing support for translational use of AR agonists in skeletal muscle recovery and regeneration.

A Novel Peptide Aldehyde with Activity against Human Cytomegalovirus in Two Different in Vivo Models

2000 ◽  
Vol 11 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Olaf Weber ◽  
Jürgen Reefschläger ◽  
Helga Rübsamen-Waigmann ◽  
Siegfried Raddatz ◽  
Matthias Hesseling ◽  
...  
Keyword(s):  
Animal Models ◽  
Antiviral Activity ◽  
Clinical Isolate ◽  
Human Cytomegalovirus ◽  
Murine Cytomegalovirus ◽  
Human Tissues ◽  
In Vivo Models ◽  
Peptide Aldehydes

Novel peptide aldehydes (PAs) were identified as potent inhibitors of human cytomegalovirus (HCMV) in vitro. Although these compounds were highly effective against HCMV, they did not exhibit any activity against murine cytomegalovirus (MCMV). The purpose of this study was to test the antiviral activity of PA 8 as a representative of this novel class of inhibitors against HCMV in vivo. Because of the strict species specificity of HCMV we had to use two artificial animal models. In the first model, HCMV-infected human cells were entrapped into agarose plugs and transplanted into mice. In the second model, SCID mice were transplanted with human tissues that were subsequently infected with a clinical isolate of HCMV. In these two models the antiviral activity of PA 8 was clearly demonstrated, ganciclovir only being slightly superior in its in vivo antiviral activity.

scholarly journals Glial Cells—The Strategic Targets in Amyotrophic Lateral Sclerosis Treatment

2020 ◽  
Vol 9 (1) ◽  
pp. 261 ◽  
Author(s):  
Tereza Filipi ◽  
Zuzana Hermanova ◽  
Jana Tureckova ◽  
Ondrej Vanatko ◽  
Miroslava Anderova
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neurons ◽  
Current Knowledge ◽  
Gene Mutations ◽  
Cell Types ◽  
In Vivo Models ◽  
Cell Therapies ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurological disease, which is characterized by the degeneration of motor neurons in the motor cortex and the spinal cord and subsequently by muscle atrophy. To date, numerous gene mutations have been linked to both sporadic and familial ALS, but the effort of many experimental groups to develop a suitable therapy has not, as of yet, proven successful. The original focus was on the degenerating motor neurons, when researchers tried to understand the pathological mechanisms that cause their slow death. However, it was soon discovered that ALS is a complicated and diverse pathology, where not only neurons, but also other cell types, play a crucial role via the so-called non-cell autonomous effect, which strongly deteriorates neuronal conditions. Subsequently, variable glia-based in vitro and in vivo models of ALS were established and used for brand-new experimental and clinical approaches. Such a shift towards glia soon bore its fruit in the form of several clinical studies, which more or less successfully tried to ward the unfavourable prognosis of ALS progression off. In this review, we aimed to summarize current knowledge regarding the involvement of each glial cell type in the progression of ALS, currently available treatments, and to provide an overview of diverse clinical trials covering pharmacological approaches, gene, and cell therapies.

scholarly journals In Vivo Models for Cholangiocarcinoma—What Can We Learn for Human Disease?

2020 ◽  
Vol 21 (14) ◽  
pp. 4993 ◽  
Author(s):  
Raphael Mohr ◽  
Burcin Özdirik ◽  
Jana Knorr ◽  
Alexander Wree ◽  
Münevver Demir ◽  
...  
Keyword(s):  
Animal Models ◽  
Human Disease ◽  
Liver Tumors ◽  
Tumor Biology ◽  
Genetic Alterations ◽  
In Vivo Models ◽  
Primary Liver Tumors ◽  
Stromal Microenvironment

Cholangiocarcinoma (CCA) comprises a heterogeneous group of primary liver tumors. They emerge from different hepatic (progenitor) cell populations, typically via sporadic mutations. Chronic biliary inflammation, as seen in primary sclerosing cholangitis (PSC), may trigger CCA development. Although several efforts were made in the last decade to better understand the complex processes of biliary carcinogenesis, it was only recently that new therapeutic advances have been achieved. Animal models are a crucial bridge between in vitro findings on molecular or genetic alterations, pathophysiological understanding, and new therapeutic strategies for the clinic. Nevertheless, it is inherently difficult to recapitulate simultaneously the stromal microenvironment (e.g., immune-competent cells, cholestasis, inflammation, PSC-like changes, fibrosis) and the tumor biology (e.g., mutational burden, local growth, and metastatic spread) in an animal model, so that it would reflect the full clinical reality of CCA. In this review, we highlight available data on animal models for CCA. We discuss if and how these models reflect human disease and whether they can serve as a tool for understanding the pathogenesis, or for predicting a treatment response in patients. In addition, open issues for future developments will be discussed.

Sign in / Sign up

Export Citation Format

Share Document