Disease Models & Mechanisms
Latest Publications


TOTAL DOCUMENTS

2029
(FIVE YEARS 564)

H-INDEX

83
(FIVE YEARS 12)

Published By The Company Of Biologists

1754-8411, 1754-8403

Author(s):  
Zhao-Feng Li ◽  
Lei Cui ◽  
Mi-Mi Jin ◽  
Dong-Yan Hu ◽  
Xiao-Gang Hou ◽  
...  

Parkinson's disease (PD) is featured with α-synuclein-based Lewy body pathology, which however was difficult to observe in conventional two-dimensional (2D) cell culture and even in animal models. We herein aimed to develop a three-dimensional (3D) cellular model of PD to recapitulate the α-synuclein pathologies. All-trans-retinoic acid-differentiated human SH-SY5Y cells and Matrigel were optimized for 3D construction. The 3D cultured cells displayed higher tyrosine hydroxylase expression and improved dopaminergic-like phenotypes than 2D cells as suggested by RNA-sequencing analyses. Multiple forms of α-synuclein, including monomer, low and high molecular weight oligomers, were differentially present in the 2D and 3D cells, but mostly remained unchanged upon the MPP+ or rotenone treatment. Phosphorylated α-synuclein was accumulated and detergent-insoluble α-synuclein fraction was observed in the neurotoxin-treated 3D cells. Importantly, Lewy body-like inclusions were captured in the 3D system, including proteinase K-resistant α-synuclein aggregates, ubiquitin aggregation, β-amyloid and β-sheet protein deposition. The study provides a unique and convenient 3D model of PD which recapitulates critical α-synuclein pathologies and should be useful in multiple PD-associated applications.


Author(s):  
Abbe H. Crawford ◽  
John C.W. Hildyard ◽  
Sophie A.M. Rushing ◽  
Dominic J. Wells ◽  
Maria Diez-Leon ◽  
...  

Duchenne muscular dystrophy (DMD), a fatal musculoskeletal disorder, is associated with neurodevelopmental disorders and cognitive impairment caused by brain dystrophin deficiency. Dog models of DMD represent key translational tools to study dystrophin biology and to develop novel therapeutics. However, characterization of dystrophin expression and function in the canine brain is lacking. We studied the DE50-MD canine model of DMD that has a missense mutation in the donor splice site of exon 50. Using a battery of cognitive tests, we detected a neurocognitive phenotype in DE50-MD dogs including reduced attention, problem-solving and exploration of novel objects. Through a combination of capillary immunoelectrophoresis, immunolabelling, qPCR and RNAScope in situ hybridization we show that regional dystrophin expression in the adult canine brain reflects that of humans, and that the DE50-MD dog lacks full length dystrophin (Dp427) protein expression but retains expression of the two shorter brain-expressed isoforms, Dp140 and Dp71. Thus, the DE50-MD dog is a translationally-relevant pre-clinical model to study the consequences of Dp427 deficiency in the brain and to develop therapeutic strategies for the neurological sequelae of DMD.


2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Sebastian Öther-Gee Pohl ◽  
Kevin B. Myant

ABSTRACT Alternative splicing is a process by which a single gene is able to encode multiple different protein isoforms. It is regulated by the inclusion or exclusion of introns and exons that are joined in different patterns prior to protein translation, thus enabling transcriptomic and proteomic diversity. It is now widely accepted that alternative splicing is dysregulated across nearly all cancer types. This widespread dysregulation means that nearly all cellular processes are affected – these include processes synonymous with the hallmarks of cancer – evasion of apoptosis, tissue invasion and metastasis, altered cellular metabolism, genome instability and drug resistance. Emerging evidence indicates that the dysregulation of alternative splicing also promotes a permissive environment for increased tumour heterogeneity and cellular plasticity. These are fundamental regulators of a patient's response to therapy. In this Review, we introduce the mechanisms of alternative splicing and the role of aberrant splicing in cancer, with particular focus on newfound evidence of alternative splicing promoting tumour heterogeneity, cellular plasticity and altered metabolism. We discuss recent in vivo models generated to study alternative splicing and the importance of these for understanding complex tumourigenic processes. Finally, we review the effects of alternative splicing on immune evasion, cell death and genome instability, and how targeting these might enhance therapeutic efficacy.


Author(s):  
Lillian Garrett ◽  
Patricia Da Silva-Buttkus ◽  
Birgit Rathkolb ◽  
Raffaele Gerlini ◽  
Lore Becker ◽  
...  

Understanding the shared genetic aetiology of psychiatric and medical comorbidity in neurodevelopmental disorders (NDDs) could improve patient diagnosis, stratification and treatment options. Rare TANC2 (Tetratricopeptide Repeat, Ankyrin Repeat and Coiled-Coil Containing 2) disrupting variants were disease-causing in NDD patients. This post-synaptic scaffold protein, essential for dendrite formation in synaptic plasticity, plays an unclarified but critical role in development. We here report a novel homozygous-viable Tanc2 disrupted function model where mutant mice were hyperactive and had impaired sensorimotor gating consistent with NDD patient psychiatric endophenotypes. Yet, a multi-systemic analysis revealed the pleiotropic effects of Tanc2 outside the brain such as growth failure and hepatocellular damage. This was associated with aberrant liver function including altered hepatocellular metabolism. Integrative analysis indicates that these disrupted Tanc2 systemic effects relate to interaction with Hippo developmental signalling pathway proteins and will increase the risk for comorbid somatic disease. This highlights how NDD gene pleiotropy can augment medical comorbidity susceptibility underscoring the benefit of holistic NDD patient diagnosis and treatment for which large-scale preclinical functional genomics can provide complementary pleiotropic gene function information.


Author(s):  
Laura Miesen ◽  
Péter Bándi ◽  
Brigith Willemsen ◽  
Fieke Mooren ◽  
Thiago Strieder ◽  
...  

In the glomerulus, Bowman's space is formed by a continuum of glomerular epithelial cells. In focal segmental glomerulosclerosis (FSGS), glomeruli show segmental scarring, a result of activated PECs invading the glomerular tuft. The segmental scars interrupt the epithelial continuum. However, non-sclerotic segments seem to be preserved even in glomeruli with advanced lesions. We studied the histology of the segmental pattern in Munich Wistar Frömter (MWF) rats, a model for secondary FSGS. Our results showed that matrix layers lined with PECs cover the sclerotic lesions. These PECs formed contacts with podocytes of the uninvolved tuft segments, restoring the epithelial continuum. Formed Bowman's spaces were still connected to the tubular system. Furthermore, in biopsies of patients with secondary FSGS we also detected matrix layers formed by PECs, separating the uninvolved from the sclerotic glomerular segments. While PECs have a major role in the formation of glomerulosclerosis, we showed that in FSGS, PECs also restore the glomerular epithelial cell continuum that surrounds Bowman's space. This process may be beneficial and indispensable for glomerular filtration in the uninvolved segments of sclerotic glomeruli.


Author(s):  
Radoslaw J. Gora ◽  
Babette de Jong ◽  
Patrick van Hage ◽  
Mary Ann Rhiemus ◽  
Fjodor van Steenis ◽  
...  

Developments in single-molecule microscopy (SMM) have enabled imaging individual proteins in biological systems, focusing on the analysis of protein mobility patterns inside cultured cells. In the present study, SMM was applied in vivo, using the zebrafish embryo model. We studied dynamics of the membrane protein H-Ras, its membrane-anchoring domain, C10H-Ras, and mutants, using total internal reflection fluorescence microscopy (TIRFM). Our results consistently confirm the presence of fast- and slow-diffusing subpopulations of molecules, which confine to microdomains within the plasma membrane. The active mutant H-RasV12 exhibits higher diffusion rates and is confined to larger domains than the wild-type H-Ras and its inactive mutant H-RasN17. Subsequently, we demonstrate that the structure and composition of the plasma membrane have an imperative role in modulating H-Ras mobility patterns. Ultimately, we establish that differences between cells within the same embryo largely contribute to the overall data variability. Our findings agree with a model where the cell architecture and the protein activation state determine protein mobility, underlining the importance of SMM imaging to study factors influencing protein dynamics in an intact living organism.


Author(s):  
Deepika Vasudevan ◽  
Hidetaka Katow ◽  
Huai-Wei Huang ◽  
Grace Tang ◽  
Hyung Don Ryoo

Metazoans have evolved various quality control mechanisms to cope with cellular stress inflicted by external and physiological conditions. ATF4 is a major effector of the Integrated Stress Response (ISR), an evolutionarily conserved pathway that mediates adaptation to various cellular stressors. Loss of function of Drosophila ATF4, encoded by the gene cryptocephal (crc), results in lethality during pupal development. The roles of crc in Drosophila disease models and in adult tissue homeostasis thus remain poorly understood. Here, we report that a protein-trap MiMIC insertion in the crc locus generates a crc-GFP fusion protein that allows visualization of crc activity in vivo. This allele also acts as a hypomorphic mutant that uncovers previously unknown roles for crc. Specifically, the crc protein-trap line shows crc-GFP induction in a Drosophila model for Retinitis Pigmentosa (RP). This crc allele renders flies more vulnerable to amino acid deprivation and age-dependent retinal degeneration. These mutants also show defects in wing veins and oocyte maturation. Together, our data reveal previously unknown roles for crc in development, cellular homeostasis and photoreceptor survival.


Author(s):  
Rita J. Serrano ◽  
Clara Lee ◽  
Alon M. Douek ◽  
Jan Kaslin ◽  
Robert J. Bryson-Richardson ◽  
...  

Cyclin-Dependent Kinase-Like-5 (CDKL5) Deficiency Disorder (CDD) is a severe X-linked neurodegenerative disease characterized by early-onset epileptic seizures, low muscle tone, progressive intellectual disability, and severe motor function. CDD affects approximately 1 in 60,000 live births with many patients experiencing a reduced quality of life due to the severity of their neurological symptoms and functional impairment. There are no effective therapies for CDD with current treatments focusing on improving symptoms rather than addressing the underlying causes of the disorder. Zebrafish offer many unique advantages for high-throughput pre-clinical evaluation of potential therapies for neurological diseases, including CDD. In particular, the large number of offspring produced, together with the possibilities for in vivo imaging and genetic manipulation, allows for the detailed assessment of disease pathogenesis and therapeutic discovery. We have characterised a loss of function zebrafish model for CDD, containing a nonsense mutation in cdkl5. cdkl5 mutant zebrafish display defects in neuronal patterning, seizures, microcephaly, and reduced muscle function caused by impaired muscle innervation. This study provides a powerful vertebrate model to investigate CDD disease pathophysiology and allow high-throughput screening for effective therapies.


Author(s):  
Toshihiro Inubushi ◽  
Ayaka Fujiwara ◽  
Takumi Hirose ◽  
Gozo Aoyama ◽  
Toshihiro Uchihashi ◽  
...  

Cleft palate is one of the major congenital craniofacial birth defects. The etiology underlying the pathogenesis of cleft palate has largely remained unelucidated. Dissociation of the medial edge epithelium (MEE) at the contacting region of palatal shelves and subsequent migration or apoptosis of MEE cells is required for the proper MEE removal. Ras Responsive Element Binding Protein 1 (RREB1), a RAS transcriptional effector, has recently been shown to play a crucial role in developmental EMT, in which loss of epithelial characteristics is an initial step, during mid-gastrulation of embryonic development. Interestingly, the involvement of RREB1 in cleft palate has been indicated in humans. Here, we demonstrated that pan-Ras inhibitor prevents the dissociation of MEE during palatal fusion. Rreb1 is expressed in the palatal epithelium during palatal fusion, and knockdown of Rreb1 in palatal organ culture resulted in palatal fusion defects by inhibiting the dissociation of MEE cells. Our present findings provide evidence that RREB1-mediated Ras signaling is required during palatal fusion. Aberrant RREB1-mediated Ras signaling might be involved in the pathogenesis of cleft palate.


Author(s):  
Diego Baronio ◽  
Yu-Chia Chen ◽  
Pertti Panula

Monoamine oxidase (MAO) deficiency and imbalanced levels of brain monoamines have been associated with developmental delay, neuropsychiatric disorders and aggressive behavior. Animal models are valuable tools to gain mechanistic insight into outcomes associated with MAO deficiency. Here we report a novel genetic model to study the effects of mao-loss-of-function in zebrafish. Quantitative PCR, in situ hybridization and immunocytochemistry were used to study neurotransmitter systems, and expression of relevant genes for brain development in zebrafish mao mutants. Larval and adult fish behavior was evaluated through different tests. A stronger serotonin immunoreactivity was detected in both mao+/- and mao−/- larvae when compared with mao+/+ siblings. Mao−/- larvae were hypoactive, presented decreased reactions to visual and acoustic stimuli. They also had impaired histaminergic and dopaminergic systems, abnormal expression of developmental markers, and they died within 20 days post-fertilization. Mao+/- fish were viable, grew until adulthood and demonstrated anxiety-like behavior and impaired social interactions when compared with adult mao+/+ siblings. Our results indicate that mao−/- and mao+/- mutants could be promising tools to study the roles of MAO in brain development and behavior.


Sign in / Sign up

Export Citation Format

Share Document