scholarly journals Cellular and animal models for facioscapulohumeral muscular dystrophy

2020 ◽  
Vol 13 (10) ◽  
pp. dmm046904
Author(s):  
Alec M. DeSimone ◽  
Justin Cohen ◽  
Monkol Lek ◽  
Angela Lek
Keyword(s):  
Muscular Dystrophy ◽  
Myogenic Differentiation ◽  
Facioscapulohumeral Muscular Dystrophy ◽  
Lower Limbs ◽  
Repeat Array ◽  
Drug Candidates ◽  
Cellular Models ◽  
Wide Range

ABSTRACTFacioscapulohumeral muscular dystrophy (FSHD) is one of the most common forms of muscular dystrophy and presents with weakness of the facial, scapular and humeral muscles, which frequently progresses to the lower limbs and truncal areas, causing profound disability. Myopathy results from epigenetic de-repression of the D4Z4 microsatellite repeat array on chromosome 4, which allows misexpression of the developmentally regulated DUX4 gene. DUX4 is toxic when misexpressed in skeletal muscle and disrupts several cellular pathways, including myogenic differentiation and fusion, which likely underpins pathology. DUX4 and the D4Z4 array are strongly conserved only in primates, making FSHD modeling in non-primate animals difficult. Additionally, its cytotoxicity and unusual mosaic expression pattern further complicate the generation of in vitro and in vivo models of FSHD. However, the pressing need to develop systems to test therapeutic approaches has led to the creation of multiple engineered FSHD models. Owing to the complex genetic, epigenetic and molecular factors underlying FSHD, it is difficult to engineer a system that accurately recapitulates every aspect of the human disease. Nevertheless, the past several years have seen the development of many new disease models, each with their own associated strengths that emphasize different aspects of the disease. Here, we review the wide range of FSHD models, including several in vitro cellular models, and an array of transgenic and xenograft in vivo models, with particular attention to newly developed systems and how they are being used to deepen our understanding of FSHD pathology and to test the efficacy of drug candidates.

scholarly journals Ways into Understanding HIF Inhibition

Cancers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 159
Author(s):  
Tina Schönberger ◽  
Joachim Fandrey ◽  
Katrin Prost-Fingerle
Keyword(s):  
Protein Interactions ◽  
Target Genes ◽  
Protein Protein Interactions ◽  
Low Oxygen ◽  
Drug Candidates ◽  
Open Questions ◽  
Wide Range ◽  
Hif Pathway

Hypoxia is a key characteristic of tumor tissue. Cancer cells adapt to low oxygen by activating hypoxia-inducible factors (HIFs), ensuring their survival and continued growth despite this hostile environment. Therefore, the inhibition of HIFs and their target genes is a promising and emerging field of cancer research. Several drug candidates target protein–protein interactions or transcription mechanisms of the HIF pathway in order to interfere with activation of this pathway, which is deregulated in a wide range of solid and liquid cancers. Although some inhibitors are already in clinical trials, open questions remain with respect to their modes of action. New imaging technologies using luminescent and fluorescent methods or nanobodies to complement widely used approaches such as chromatin immunoprecipitation may help to answer some of these questions. In this review, we aim to summarize current inhibitor classes targeting the HIF pathway and to provide an overview of in vitro and in vivo techniques that could improve the understanding of inhibitor mechanisms. Unravelling the distinct principles regarding how inhibitors work is an indispensable step for efficient clinical applications and safety of anticancer compounds.

scholarly journals hPSC-Derived Enteric Ganglioids Model Human ENS Development and Function

2022 ◽  
Author(s):  
Homa Majd ◽  
Ryan M Samuel ◽  
Jonathan T Ramirez ◽  
Ali Kalantari ◽  
Kevin Barber ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Xenograft Model ◽  
Developmental Relationships ◽  
Drug Candidates ◽  
Effective Strategies ◽  
Wide Range ◽  
Functional Features ◽  
And Function

The enteric nervous system (ENS) plays a central role in gut physiology and mediating the crosstalk between the gastrointestinal (GI) tract and other organs. The human ENS has remained elusive, highlighting the need for an in vitro modeling and mapping blueprint. Here we map out the developmental and functional features of the human ENS, by establishing robust and scalable 2D ENS cultures and 3D enteric ganglioids from human pluripotent stem cells (hPSCs). These models recapitulate the remarkable neuronal and glial diversity found in primary tissue and enable comprehensive molecular analyses that uncover functional and developmental relationships within these lineages. As a salient example of the power of this system, we performed in-depth characterization of enteric nitrergic neurons (NO neurons) which are implicated in a wide range of GI motility disorders. We conducted an unbiased screen and identified drug candidates that modulate the activity of NO neurons and demonstrated their potential in promoting motility in mouse colonic tissue ex vivo. We established a high-throughput strategy to define the developmental programs involved in NO neuron specification and discovered that PDGFR inhibition boosts the induction of NO neurons in enteric ganglioids. Transplantation of these ganglioids in the colon of NO neuron-deficient mice results in extensive tissue engraftment, providing a xenograft model for the study of human ENS in vivo and the development of cell-based therapies for neurodegenerative GI disorders. These studies provide a framework for deciphering fundamental features of the human ENS and designing effective strategies to treat enteric neuropathies.  

scholarly journals Flavonoids as anti-inflammatory agents

2010 ◽  
Vol 69 (3) ◽  
pp. 273-278 ◽  
Author(s):  
Mauro Serafini ◽  
Ilaria Peluso ◽  
Anna Raguzzini
Keyword(s):  
Related Factor ◽  
Plant Foods ◽  
Reactive Protein ◽  
Cellular Models ◽  
Chemical Structures ◽  
Markers Of Inflammation ◽  
Wide Range ◽  
Anti Inflammatory

Epidemiological evidence suggests that a high intake of plant foods is associated with lower risk of chronic diseases. However, the mechanism of action and the components involved in this effect have not been identified clearly. In recent years, the scientific community has agreed to focus its attention on a class of secondary metabolites extensively present in a wide range of plant foods: the flavonoids, suggested as having different biological roles. The anti-inflammatory actions of flavonoids in vitro or in cellular models involve the inhibition of the synthesis and activities of different pro-inflammatory mediators such as eicosanoids, cytokines, adhesion molecules and C-reactive protein. Molecular activities of flavonoids include inhibition of transcription factors such as NF-κB and activating protein-1 (AP-1), as well as activation of nuclear factor-erythroid 2-related factor 2 (Nrf2). However, the in vitro evidence might be somehow of limited impact due to the non-physiological concentrations utilized and to the fact that in vivo flavonoids are extensively metabolized to molecules with different chemical structures and activities compared with the ones originally present in the food. Human studies investigating the effect of flavonoids on markers of inflammation are insufficient, and are mainly focused on flavonoid-rich foods but not on pure molecules. Most of the studies lack assessment of flavonoid absorption or fail to associate an effect on inflammation with a change in circulating levels of flavonoids. Human trials with appropriate placebo and pure flavonoid molecules are needed to clarify if flavonoids represent ancillary ingredients or key molecules involved in the anti-inflammatory properties of plant foods.

scholarly journals Lamin-related congenital muscular dystrophy alters mechanical signaling and skeletal muscle growth

2020 ◽  
Author(s):  
Daniel J. Owens ◽  
Julien Messéant ◽  
Sophie Moog ◽  
Mark Viggars ◽  
Arnaud Ferry ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscular Dystrophy ◽  
Disease Severity ◽  
Myogenic Differentiation ◽  
Muscle Growth ◽  
Congenital Muscular Dystrophy ◽  
Skeletal Muscle Growth ◽  
Muscle Biopsies

AbstractBackgroundLaminopathies are a clinically heterogeneous group of disorders caused by mutations in the LMNA gene, which encodes the nuclear envelope proteins lamins A and C. The most frequent diseases associated with LMNA mutations are characterized by skeletal and cardiac involvement, and include autosomal dominant Emery-Dreifuss muscular dystrophy (EDMD), limb-girdle muscular dystrophy type 1B, and LMNA-related congenital muscular dystrophy (LMNA-CMD). Although the exact pathophysiological mechanisms responsible for LMNA-CMD are not yet understood, severe contracture and muscle atrophy suggest that impair skeletal muscle growth may contribute to the disease severity.MethodsWe used human muscle stem cells (MuSCs) carrying 4 different LMNA mutations and two mouse models of muscle laminopathies, representing a spectrum of disease severity, to investigate the ability of skeletal muscle to differentiate and to hypertrophy in response to mechanical challenges. We extended these finding to individuals with LMNA-related muscular dystrophy using muscle biopsies.ResultsIn vitro, we observe impaired myogenic differentiation with disorganized cadherin/β catenin adhesion complexes in MuSCs carrying LMNA-CMD. We show that skeletal muscle from Lmna-CMD mice is unable to hypertrophy in response to functional overload, due to defective accretion of activated MuSCs, defective protein synthesis and defective remodeling of the neuro-muscular junction. Moreover, stretched myotubes and overloaded muscle fibers with LMNA-CMD mutations display aberrant mechanical regulation of the Yes-Associated Protein (YAP), a key sensor and mediator of mechanical cues. We also observe defects in MuSC activation and YAP signaling in muscle biopsies from LMNA-CMD patients. These phenotypes are not recapitulated in closely-related EDMD models.ConclusionsCombining studies in vitro, in vivo and patient samples, we find that LMNA-CMD mutations interfere with mechano-signaling pathways in skeletal muscle, implicating defective skeletal muscle growth as a pathogenic contributor for the severity of LMNA-related muscular dystrophy.

scholarly journals Inhibition ofDUX4expression with antisense LNA gapmers as a therapy for facioscapulohumeral muscular dystrophy

2020 ◽  
Vol 117 (28) ◽  
pp. 16509-16515 ◽  
Author(s):  
Kenji Rowel Q. Lim ◽  
Rika Maruyama ◽  
Yusuke Echigoya ◽  
Quynh Nguyen ◽  
Aiping Zhang ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Messenger Rna ◽  
Screening Method ◽  
Local Treatment ◽  
Facioscapulohumeral Muscular Dystrophy ◽  
Locked Nucleic Acid ◽  
Aberrant Expression ◽  
Progressive Muscle Weakness

Facioscapulohumeral muscular dystrophy (FSHD), characterized by progressive muscle weakness and deterioration, is genetically linked to aberrant expression ofDUX4in muscle. DUX4, in its full-length form, is cytotoxic in nongermline tissues. Here, we designed locked nucleic acid (LNA) gapmer antisense oligonucleotides (AOs) to knock downDUX4in immortalized FSHD myoblasts and theFLExDUX4FSHD mouse model. Using a screening method capable of reliably evaluating the knockdown efficiency of LNA gapmers against endogenousDUX4messenger RNA in vitro, we demonstrate that several designed LNA gapmers selectively and effectively reducedDUX4expression with nearly complete knockdown. We also found potential functional benefits of AOs on muscle fusion and structure in vitro. Finally, we show that one of the LNA gapmers was taken up and induced effective silencing ofDUX4upon local treatment in vivo. The LNA gapmers developed here will help facilitate the development of FSHD therapies.

scholarly journals HGG-23. IN VITRO AND IN VIVO PRECLINICAL DRUG SCREENING OF PROMISING THERAPEUTICS FOR DIFFUSE MIDLINE GLIOMA (DMG)

2021 ◽  
Vol 23 (Supplement_1) ◽  
pp. i21-i22
Author(s):  
Chiara Cianciolo Cosentino ◽  
Sandra Laternser ◽  
Justyna M Przystal ◽  
Sridevi Yadavilli ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Tumor Biology ◽  
In Vivo Studies ◽  
Continuous Exposure ◽  
Intrinsic Resistance ◽  
Drug Candidates ◽  
Zebrafish Larvae ◽  
Wide Range

Abstract Introduction Diffuse midline gliomas (DMGs) are amongst the most unforgiving pediatric brain tumors, characterized by an intrinsic resistance to therapy. Despite major advances in understanding of tumor biology, the prognosis remains exceedingly poor, and treatment options are limited. New therapeutics are being evaluated at a fast rate by different laboratories. In order to prioritize effective drug candidates for DMG treatment, we comprehensively characterized a panel of promising therapeutic agents in in vitro and in different vivo systems. Methods We determined the sensitivity of primary DMG cell lines to a panel of small molecule inhibitors targeting known DMG targets and pathways. Dose response curves were generated for more than 20 different compounds and possible synergistic effects were investigated by SynergieFinder. In an effort to highlight potential toxicities and associated mechanisms at a large scale, we performed a preclinical toxicity evaluation in zebrafish larvae, with a slightly modified version of the official Fish Embryo Acute Toxicity (FET) test. Drug toxicity was tested by continuous exposure of zebrafish larvae to increasing concentrations of the different compounds. Survival curves, morphological analyses and behavioral tests were performed at a maximum tolerated dose (MTD). To confirm the findings obtained in zebrafish, we further performed in vivo studies in mice for promising candidates. Results Among the tested drugs in vitro we found 10 drugs showing promising dose- dependent reduction in cell viability with IC50 in nM to µM range. These were further evaluated for toxicity in zebrafish. The zebrafish larvae toxicities observations strongly correlated with the findings in murine in vivo studies, reinforcing the importance of zebrafish as an accurate investigative toxicology model to assess acute toxicity of molecules in preclinical studies. Conclusions By testing a wide range of drugs, targeting different pathways on DMG cells and in different in vivo systems we identified promising drug candidates for clinical management of children diagnosed with DMG.

scholarly journals In VitroEffects of Strontium on Proliferation and Osteoinduction of Human Preadipocytes

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
V. Nardone ◽  
R. Zonefrati ◽  
C. Mavilia ◽  
C. Romagnoli ◽  
S. Ciuffi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Bone Tissue Regeneration ◽  
Cell Therapies ◽  
Cellular Models ◽  
Alp Activity ◽  
Wide Range ◽  
Marrow Mesenchymal Stem Cells

Development of tools to be used forin vivobone tissue regeneration focuses on cellular models and differentiation processes. In searching for all the optimal sources, adipose tissue-derived mesenchymal stem cells (hADSCs or preadipocytes) are able to differentiate into osteoblasts with analogous characteristics to bone marrow mesenchymal stem cells, producing alkaline phosphatase (ALP), collagen, osteocalcin, and calcified nodules, mainly composed of hydroxyapatite (HA). The possibility to influence bone differentiation of stem cells encompasses local and systemic methods, including the use of drugs administered systemically. Among the latter, strontium ranelate (SR) represents an interesting compound, acting as an uncoupling factor that stimulates bone formation and inhibits bone resorption. The aim of our study was to evaluate thein vitroeffects of a wide range of strontium (Sr2+) concentrations on proliferation, ALP activity, and mineralization of a novel finite clonal hADSCs cell line, named PA20-h5. Sr2+promoted PA20-h5 cell proliferation while inducing the increase of ALP activity and gene expression as well as HA production duringin vitroosteoinduction. These findings indicate a role for Sr2+in supporting bone regeneration during the process of skeletal repair in general, and, more specifically, when cell therapies are applied.

scholarly journals In silicoidentification of novel peptides with antibacterial activity against multidrug resistantStaphylococcus aureus

2019 ◽  
Author(s):  
Linda B Oyama ◽  
Hamza Olleik ◽  
Ana Carolina Nery Teixeira ◽  
Matheus M Guidini ◽  
James A Pickup ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptides ◽  
In Silico ◽  
Multidrug Resistant ◽  
Biofilm Inhibition ◽  
Methicillin Resistant ◽  
Drug Candidates ◽  
Wide Range

AbstractHerein we report the identification and characterisation of two linear antimicrobial peptides (AMPs), HG2 and HG4, with activity against a wide range of multidrug resistant (MDR) bacteria, especially methicillin resistantStaphylococcus aureus(MRSA) strains, a highly problematic group of Gram-positive bacteria in the hospital and community environment. To identify the novel AMPs presented here, we employed the classifier model design, a feature extraction method using molecular descriptors for amino acids for the analysis, visualization, and interpretation of AMP activities from a rumen metagenomic dataset. This allowed for thein silicodiscrimination of active and inactive peptides in order to define a small number of promising novel lead AMP test candidates for chemical synthesis and experimental evaluation.In vitrodata suggest that the chosen AMPs are fast acting, show strong biofilm inhibition and dispersal activity and are efficacious in anin vivomodel of MRSA USA300 infection, whilst showing little toxicity to human erythrocytes and human primary cell linesex vivo. Observations from biophysical AMP-lipid-interactions and electron microscopy suggest that the newly identified peptides interact with the cell membrane and may be involved in the inhibition of other cellular processes. Amphiphilic conformations associated with membrane disruption are also observed in 3D molecular modelling of the peptides. HG2 and HG4 both preferentially bind to MRSA total lipids rather than with human cell lipids indicating that HG4 may form superior templates for safer therapeutic candidates for MDR bacterial infections.Author SummaryWe are losing our ability to treat multidrug resistant (MDR) bacteria, otherwise known as superbugs. This poses a serious global threat to human health as bacteria are increasingly acquiring resistance to antibiotics. There is therefore urgent need to intensify our efforts to develop new safer alternative drug candidates. We emphasise the usefulness of complementing wet-lab andin silicotechniques for the rapid identification of new drug candidates from environmental samples, especially antimicrobial peptides (AMPs). HG2 and HG4, the AMPs identified in our study show promise as effective therapies for the treatment of methicillin resistantStaphylococcus aureusinfections bothin vitroandin vivowhilst having little cytotoxicity against human primary cells, a step forward in the fight against MDR infections.

scholarly journals Mesoangioblasts from Facioscapulohumeral Muscular Dystrophy Display in Vivo a Variable Myogenic Ability Predictable by their in Vitro Behavior

2011 ◽  
Vol 20 (8) ◽  
pp. 1299-1313 ◽  
Author(s):  
Roberta Morosetti ◽  
Teresa Gidaro ◽  
Aldobrando Broccolini ◽  
Carla Gliubizzi ◽  
Cristina Sancricca ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Facioscapulohumeral Muscular Dystrophy

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

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