scholarly journals Dynamics of a Protein Interaction Network Associated to the Aggregation of polyQ-Expanded Ataxin-1

Genes ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1129
Author(s):  
Aimilia-Christina Vagiona ◽  
Miguel A. Andrade-Navarro ◽  
Fotis Psomopoulos ◽  
Spyros Petrakis
Keyword(s):  
Animal Models ◽  
Protein Aggregation ◽  
Disease Progression ◽  
Protein Interaction ◽  
Molecular Mechanisms ◽  
Spinocerebellar Ataxia Type ◽  
In Vivo Model ◽  
Ppi Networks

Background: Several experimental models of polyglutamine (polyQ) diseases have been previously developed that are useful for studying disease progression in the primarily affected central nervous system. However, there is a missing link between cellular and animal models that would indicate the molecular defects occurring in neurons and are responsible for the disease phenotype in vivo. Methods: Here, we used a computational approach to identify dysregulated pathways shared by an in vitro and an in vivo model of ATXN1(Q82) protein aggregation, the mutant protein that causes the neurodegenerative polyQ disease spinocerebellar ataxia type-1 (SCA1). Results: A set of common dysregulated pathways were identified, which were utilized to construct cerebellum-specific protein-protein interaction (PPI) networks at various time-points of protein aggregation. Analysis of a SCA1 network indicated important nodes which regulate its function and might represent potential pharmacological targets. Furthermore, a set of drugs interacting with these nodes and predicted to enter the blood–brain barrier (BBB) was identified. Conclusions: Our study points to molecular mechanisms of SCA1 linked from both cellular and animal models and suggests drugs that could be tested to determine whether they affect the aggregation of pathogenic ATXN1 and SCA1 disease progression.

scholarly journals Caenorhabditis elegans as an in vivo Model to Assess Amphetamine Tolerance

2021 ◽  
pp. 1-9
Author(s):  
Dayana Torres Valladares ◽  
Sirisha Kudumala ◽  
Murad Hossain ◽  
Lucia Carvelli
Keyword(s):  
Caenorhabditis Elegans ◽  
Molecular Mechanisms ◽  
Drugs Of Abuse ◽  
Genetic Model ◽  
In Vivo Model ◽  
C Elegans ◽  
Hyperactivity Disorder ◽  
In Vitro Data

Amphetamine is a potent psychostimulant also used to treat attention deficit/hyperactivity disorder and narcolepsy. In vivo and in vitro data have demonstrated that amphetamine increases the amount of extra synaptic dopamine by both inhibiting reuptake and promoting efflux of dopamine through the dopamine transporter. Previous studies have shown that chronic use of amphetamine causes tolerance to the drug. Thus, since the molecular mechanisms underlying tolerance to amphetamine are still unknown, an animal model to identify the neurochemical mechanisms associated with drug tolerance is greatly needed. Here we took advantage of a unique behavior caused by amphetamine in <i>Caenorhabditis elegans</i> to investigate whether this simple, but powerful, genetic model develops tolerance following repeated exposure to amphetamine. We found that at least 3 treatments with 0.5 mM amphetamine were necessary to see a reduction in the amphetamine-induced behavior and, thus, to promote tolerance. Moreover, we found that, after intervals of 60/90 minutes between treatments, animals were more likely to exhibit tolerance than animals that underwent 10-minute intervals between treatments. Taken together, our results show that <i>C. elegans</i> is a suitable system to study tolerance to drugs of abuse such as amphetamines.

scholarly journals Chloroquine enhances temozolomide cytotoxicity in malignant gliomas by blocking autophagy

2014 ◽  
Vol 37 (6) ◽  
pp. E12 ◽  
Author(s):  
Encouse B. Golden ◽  
Hee-Yeon Cho ◽  
Ardeshir Jahanian ◽  
Florence M. Hofman ◽  
Stan G. Louie ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
In Vivo Model ◽  
Autophagosome Formation ◽  
Individual Drug ◽  
In Vivo Experiments ◽  
Associated Proteins

Object In a recent clinical trial, patients with newly diagnosed glioblastoma multiforme benefited from chloroquine (CQ) in combination with conventional therapy (resection, temozolomide [TMZ], and radiation therapy). In the present study, the authors report the mechanism by which CQ enhances the therapeutic efficacy of TMZ to aid future studies aimed at improving this therapeutic regimen. Methods Using in vitro and in vivo experiments, the authors determined the mechanism by which CQ enhances TMZ cytotoxicity. They focused on the inhibition-of-autophagy mechanism of CQ by knockdown of the autophagy-associated proteins or treatment with autophagy inhibitors. This mechanism was tested using an in vivo model with subcutaneously implanted U87MG tumors from mice treated with CQ in combination with TMZ. Results Knockdown of the autophagy-associated proteins (GRP78 and Beclin) or treatment with the autophagy inhibitor, 3-methyl adenine (3-MA), blocked autophagosome formation and reduced CQ cytotoxicity, suggesting that autophagosome accumulation precedes CQ-induced cell death. In contrast, blocking autophagosome formation with knockdown of GRP78 or treatment with 3-MA enhanced TMZ cytotoxicity, suggesting that the autophagy pathway protects from TMZ-induced cytotoxicity. CQ in combination with TMZ significantly increased the amounts of LC3B-II (a marker for autophagosome levels), CHOP/GADD-153, and cleaved PARP (a marker for apoptosis) over those with untreated or individual drug-treated glioma cells. These molecular mechanisms seemed to take place in vivo as well. Subcutaneously implanted U87MG tumors from mice treated with CQ in combination with TMZ displayed higher levels of CHOP/GADD-153 than did untreated or individual drug-treated tumors. Conclusions Taken together, these results demonstrate that CQ blocks autophagy and triggers endoplasmic reticulum stress, thereby increasing the chemosensitivity of glioma cells to TMZ.

scholarly journals Spontaneous self-assembly of pathogenic huntingtin exon 1 protein into amyloid structures

2014 ◽  
Vol 56 ◽  
pp. 167-180 ◽  
Author(s):  
Philipp Trepte ◽  
Nadine Strempel ◽  
Erich E. Wanker
Keyword(s):  
Self Assembly ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Cytoplasmic Inclusion ◽  
Spinocerebellar Ataxia Type ◽  
Neuronal Processes ◽  
Exon 1 ◽  
Novel Therapeutic Strategies

PolyQ (polyglutamine) diseases such as HD (Huntington's disease) or SCA1 (spinocerebellar ataxia type 1) are neurodegenerative disorders caused by abnormally elongated polyQ tracts in human proteins. PolyQ expansions promote misfolding and aggregation of disease-causing proteins, leading to the appearance of nuclear and cytoplasmic inclusion bodies in patient neurons. Several lines of experimental evidence indicate that this process is critical for disease pathogenesis. However, the molecular mechanisms underlying spontaneous polyQ-containing aggregate formation and the perturbation of neuronal processes are still largely unclear. The present chapter reviews the current literature regarding misfolding and aggregation of polyQ-containing disease proteins. We specifically focus on studies that have investigated the amyloidogenesis of polyQ-containing HTTex1 (huntingtin exon 1) fragments. These protein fragments are disease-relevant and play a critical role in HD pathogenesis. We outline potential mechanisms behind mutant HTTex1 aggregation and toxicity, as well as proteins and small molecules that can modify HTTex1 amyloidogenesis in vitro and in vivo. The potential implications of such studies for the development of novel therapeutic strategies are discussed.

scholarly journals Molecular Mechanisms Involved in the Pathogenesis of Alphavirus-Induced Arthritis

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Iranaia Assunção-Miranda ◽  
Christine Cruz-Oliveira ◽  
Andrea T. Da Poian
Keyword(s):  
Animal Models ◽  
Sindbis Virus ◽  
Molecular Mechanisms ◽  
Public Health Problem ◽  
Target Cells ◽  
Important Public Health Problem ◽  
Muscle Tissues ◽  
Mayaro Virus

Arthritogenic alphaviruses, including Ross River virus (RRV), Chikungunya virus (CHIKV), Sindbis virus (SINV), Mayaro virus (MAYV), O'nyong-nyong virus (ONNV), and Barmah Forest virus (BFV), cause incapacitating and long lasting articular disease/myalgia. Outbreaks of viral arthritis and the global distribution of these diseases point to the emergence of arthritogenic alphaviruses as an important public health problem. This review discusses the molecular mechanisms involved in alphavirus-induced arthritis, exploring the recent data obtained within vitrosystems andin vivostudies using animal models and samples from patients. The factors associated to the extension and persistence of symptoms are highlighted, focusing on (a) virus replication in target cells, and tissues, including macrophages and muscle cells; (b) the inflammatory and immune responses with recruitment and activation of macrophage, NK cells and T lymphocytes to the lesion focus and the increase of inflammatory mediators levels; and (c) the persistence of virus or viral products in joint and muscle tissues. We also discuss the importance of the establishment of novel animal models to test new molecular targets and to develop more efficient and selective drugs to treat these diseases.

scholarly journals Estrogens and atherosclerosis: insights from animal models and cell systems

2012 ◽  
Vol 48 (2) ◽  
pp. R13-R29 ◽  
Author(s):  
Jerzy-Roch Nofer
Keyword(s):  
Animal Models ◽  
Molecular Mechanisms ◽  
Dietary Cholesterol ◽  
Epidemiological Studies ◽  
Transgenic Mouse Models ◽  
Cell Systems ◽  
Physiological Processes ◽  
Atherosclerotic Lesions

Estrogens not only play a pivotal role in sexual development but are also involved in several physiological processes in various tissues including vasculature. While several epidemiological studies documented an inverse relationship between plasma estrogen levels and the incidence of cardiovascular disease and related it to the inhibition of atherosclerosis, an interventional trial showed an increase in cardiovascular events among postmenopausal women on estrogen treatment. The development of atherosclerotic lesions involves complex interplay between various pro- or anti-atherogenic processes that can be effectively studied onlyin vivoin appropriate animal models. With the advent of genetic engineering, transgenic mouse models of atherosclerosis have supplemented classical dietary cholesterol-induced disease models such as the cholesterol-fed rabbit. In the last two decades, these models were widely applied along within vitrocell systems to specifically investigate the influence of estrogens on the development of early and advanced atherosclerotic lesions. The present review summarizes the results of these studies and assesses their contribution toward better understanding of molecular mechanisms underlying anti- and/or pro-atherogenic effects of estrogens in humans.

scholarly journals In Vitro and In Vivo Models to Study Nephropathic Cystinosis

Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 6
Author(s):  
Pang Yuk Cheung ◽  
Patrick T. Harrison ◽  
Alan J. Davidson ◽  
Jennifer A. Hollywood
Keyword(s):  
Cell Lines ◽  
Molecular Mechanisms ◽  
Primary Cultures ◽  
Model Systems ◽  
In Vivo Model ◽  
Nephropathic Cystinosis ◽  
In Vivo Models ◽  
Induced Pluripotent

The development over the past 50 years of a variety of cell lines and animal models has provided valuable tools to understand the pathophysiology of nephropathic cystinosis. Primary cultures from patient biopsies have been instrumental in determining the primary cause of cystine accumulation in the lysosomes. Immortalised cell lines have been established using different gene constructs and have revealed a wealth of knowledge concerning the molecular mechanisms that underlie cystinosis. More recently, the generation of induced pluripotent stem cells, kidney organoids and tubuloids have helped bridge the gap between in vitro and in vivo model systems. The development of genetically modified mice and rats have made it possible to explore the cystinotic phenotype in an in vivo setting. All of these models have helped shape our understanding of cystinosis and have led to the conclusion that cystine accumulation is not the only pathology that needs targeting in this multisystemic disease. This review provides an overview of the in vitro and in vivo models available to study cystinosis, how well they recapitulate the disease phenotype, and their limitations.

A Comprehensive Review on Preclinical Diabetic Models

2020 ◽  
Vol 16 (2) ◽  
pp. 104-116
Author(s):  
Anshul Shakya ◽  
Sushil Kumar Chaudary ◽  
Debapriya Garabadu ◽  
Hans Raj Bhat ◽  
Bibhuti Bhusan Kakoti ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Animal Models ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Therapeutic Agents ◽  
Ongoing Research ◽  
Chronic Hyperglycemia ◽  
Limited Effectiveness

Background: Preclinical experimental models historically play a critical role in the exploration and characterization of disease pathophysiology. Further, these in-vivo and in-vitro preclinical experiments help in target identification, evaluation of novel therapeutic agents and validation of treatments. Introduction: Diabetes mellitus (DM) is a multifaceted metabolic disorder of multidimensional aetiologies with the cardinal feature of chronic hyperglycemia. To avoid or minimize late complications of diabetes and related costs, primary prevention and early treatment are therefore necessary. Due to its chronic manifestations, new treatment strategies need to be developed, because of the limited effectiveness of the current therapies. Methods: The study included electronic databases such as Pubmed, Web of Science and Scopus. The datasets were searched for entries of studies up to June, 2018. Results: A large number of in-vivo and in-vitro models have been presented for evaluating the mechanism of anti-hyperglycaemic effect of drugs in hormone-, chemically-, pathogen-induced animal models of diabetes mellitus. The advantages and limitations of each model have also been addressed in this review. Conclusion: This review encompasses the wide pathophysiological and molecular mechanisms associated with diabetes, particularly focusing on the challenges associated with the evaluation and predictive validation of these models as ideal animal models for preclinical assessments and discovering new drugs and therapeutic agents for translational application in humans. This review may further contribute to discover a novel drug to treat diabetes more efficaciously with minimum or no side effects. Furthermore, it also highlights ongoing research and considers the future perspectives in the field of diabetes.

148. HORMONAL REGULATION OF miRNA IN THE TESTIS

2009 ◽  
Vol 21 (9) ◽  
pp. 66 ◽  
Author(s):  
P. K. Nicholls ◽  
C. A. Harrison ◽  
L. O'Donnell ◽  
P. G. Stanton
Keyword(s):  
Protein Expression ◽  
Sertoli Cells ◽  
Hormonal Regulation ◽  
Molecular Mechanisms ◽  
Reproductive Hormones ◽  
Hormonal Control ◽  
In Vivo Model ◽  
Micro Rnas

Acute suppression of circulating reproductive hormones (FSH and testosterone) inhibits sperm release (spermiation) (1), although the molecular mechanisms of spermiation failure are poorly understood. Micro-RNAs (miRNAs) are small non-coding RNAs that regulate protein expression, and are essential for normal spermatogenesis. Recent studies suggest that miRNAs are exquisitely sensitive to hormonal control by FSH, LH and testosterone (2–4). This suggests that hormonal regulation of miRNAs in the testis following acute hormonal suppression may contribute to spermiation failure. Therefore, we hypothesised that gonadotrophin regulated miRNAs control spermiation outcome. We used array analysis to show that miRNA expression is hormonally regulated by FSH and testosterone in our rat in vivo model of spermiation failure and also in primary rat Sertoli cells by. qPCR validation revealed that miR-7b, -23a, -30c, -125b, -148b, -197, -483, -592, and -690 are all hormonally sensitive testicular miRNAs. Bioinformatic analyses of potential gene targets of these miRNAs predicted numerous protein components localised in the testicular tubulobulbar complex (TBC). The TBC is a podosome-like structure found between Sertoli cells and adjacent germ cells in the testis, and is thought to internalise intact inter-cellular structures and regulate spermatid head shape prior to spermiation. WASP, a TBC protein that regulates actin filament dynamics, contained a conserved binding site for miR-690 within its 3'UTR. Increased miR-690 expression following hormone suppression corresponded to a decrease in WASP protein expression in vivo and in vitro. In addition, transfection of miR-690 into HEK293T cells down-regulated WASP protein. Our results suggest that following hormone suppression, miR-690 is stimulated in the Sertoli cell, thereby inhibiting WASP protein expression. We conclude that miRNA-mediated disruption of TBC integrity potentially regulates spermatid disengagement. This study describes new molecular mechanisms in the testis that may control spermiation outcome of potential significance in male hormonal contraception.

CKS1B, Mapping to an Amplicon on Chromosome 1q21 and over Expressed in Aggressive Disease, Regulates Multiple Myeloma Growth and Survival through p27Kip1-Dependent and Independent Mechanisms.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3408-3408
Author(s):  
Fenghuang Zhan ◽  
Simona Colla ◽  
James B. Chen ◽  
James P. Stewart ◽  
Xiaosong Wu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
High Risk ◽  
Disease Progression ◽  
Molecular Mechanisms ◽  
Plasma Cells ◽  
Regulatory Subunit ◽  
Plasma Cell Dyscrasia ◽  
P27kip1 Protein

Abstract While deregulated expression of a D-type cyclin is thought to represent an initiating event in myelomagenesis, the molecular mechanisms of disease progression are not understood. We recently reported that disease progression and high-risk disease are strongly correlated with increased copy number and expression of genes mapping to chromosome 1q. Here we report that elevated expression of CKS1B, a regulatory subunit of the SCF-Skp2 ubiquitin ligase that regulates p27Kip1 protein stability, mapping to an amplicon at 1q21 and over expressed in high-risk myeloma, is required for myeloma cell survival both in vitro and in-vivo. CKS1B expression, absent in plasma cells from healthy individuals and the benign plasma cell dyscrasia monoclonal gammopathy of undetermined significance, is inversely correlated with p27Kip1 protein levels in primary MM. Silencing of CKS1B in MM cell lines JJN3 and OCI-MY5 using shRNAs delivered by constitutive and inducible lentivirus vectors induced stabilization of p27Kip1, cell cycle arrest and apoptosis. Over expression of a non-degradable form of p27Kip1 in JJN3 and OCI-MY5 cells inhibited cell cycle progression, but did not induce apoptosis. We propose that CKS1B may play in important role in myeloma progression through p27Kip1-related and unrelated mechanisms.

scholarly journals A 3D Model of Human Trabecular Meshwork for the Research Study of Glaucoma

2020 ◽  
Vol 11 ◽  
Author(s):  
Sara Tirendi ◽  
Sergio Claudio Saccà ◽  
Stefania Vernazza ◽  
Carlo Traverso ◽  
Anna Maria Bassi ◽  
...  
Keyword(s):  
Animal Models ◽  
Trabecular Meshwork ◽  
Molecular Mechanisms ◽  
Three Dimensional ◽  
Cellular Level ◽  
Research Progress ◽  
New Therapeutic Approaches

Glaucoma is a multifactorial syndrome in which the development of pro-apoptotic signals are the causes for retinal ganglion cell (RGC) loss. Most of the research progress in the glaucoma field have been based on experimentally inducible glaucoma animal models, which provided results about RGC loss after either the crash of the optic nerve or IOP elevation. In addition, there are genetically modified mouse models (DBA/2J), which make the study of hereditary forms of glaucoma possible. However, these approaches have not been able to identify all the molecular mechanisms characterizing glaucoma, possibly due to the disadvantages and limits related to the use of animals. In fact, the results obtained with small animals (i.e., rodents), which are the most commonly used, are often not aligned with human conditions due to their low degree of similarity with the human eye anatomy. Although the results obtained from non-human primates are in line with human conditions, they are little used for the study of glaucoma and its outcomes at cellular level due to their costs and their poor ease of handling. In this regard, according to at least two of the 3Rs principles, there is a need for reliable human-based in vitro models to better clarify the mechanisms involved in disease progression, and possibly to broaden the scope of the results so far obtained with animal models. The proper selection of an in vitro model with a “closer to in vivo” microenvironment and structure, for instance, allows for the identification of the biomarkers involved in the early stages of glaucoma and contributes to the development of new therapeutic approaches. This review summarizes the most recent findings in the glaucoma field through the use of human two- and three-dimensional cultures. In particular, it focuses on the role of the scaffold and the use of bioreactors in preserving the physiological relevance of in vivo conditions of the human trabecular meshwork cells in three-dimensional cultures. Moreover, data from these studies also highlight the pivotal role of oxidative stress in promoting the production of trabecular meshwork-derived pro-apoptotic signals, which are one of the first marks of trabecular meshwork damage. The resulting loss of barrier function, increase of intraocular pressure, as well the promotion of neuroinflammation and neurodegeneration are listed as the main features of glaucoma. Therefore, a better understanding of the first molecular events, which trigger the glaucoma cascade, allows the identification of new targets for an early neuroprotective therapeutic approach.

Sign in / Sign up

Export Citation Format

Share Document