Selected Grantee Publications
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- 42 results found
- Invertebrate Models
- Aquatic Vertebrate Models
- Genetics
Mechanical Force of Uterine Occupation Enables Large Vesicle Extrusion From Proteostressed Maternal Neurons
Wang et al., eLife. 2024.
https://pubmed.ncbi.nlm.nih.gov/39255003
This study investigates how mechanical forces from uterine occupation influence large vesicle extrusion (exopher production) from proteostressed maternal neurons in Caenorhabditis elegans. Exophers, previously found to remove damaged cellular components, are poorly understood. Researchers demonstrate that mechanical stress significantly increases exopher release from touch receptor neurons (i.e., ALMR) during peak reproductive periods, coinciding with egg production. Genetic disruptions reducing reproductive activity suppress exopher extrusion, whereas interventions promoting egg retention enhance it. These findings reveal that reproductive and mechanical factors modulate neuronal stress responses, providing insight on how systemic physiological changes affect neuronal health and proteostasis, with broader implications for reproductive-neuronal interactions. Supported by ORIP (R24OD010943, P40OD010440), NIA, and NIGMS.
Stat3 Mediates Fyn Kinase-Driven Dopaminergic Neurodegeneration and Microglia Activation
Siddiqui et al., Disease Models & Mechanisms. 2024.
https://pubmed.ncbi.nlm.nih.gov/39641161
The FYN gene is a risk locus for Alzheimer’s disease and several other neurodegenerative disorders. FYN encodes Fyn kinase, and previous studies have shown that Fyn signaling in dopaminergic neurons and microglia plays a role during neurodegeneration. This study investigated Fyn signaling using zebrafish that express a constitutively active Fyn Y531F mutant in neural cells. Activated neural Fyn signaling in the mutant animals resulted in dopaminergic neuron loss and induced inflammatory cytokine expression when compared with controls. Transcriptomic and chemical inhibition analyses revealed that Fyn-driven changes were dependent on the Stat3 and NF-κB signaling pathways, which work synergistically to activate neuronal inflammation and degeneration. This study provides insight into the mechanisms underlying neurodegeneration, identifying Stat3 as a novel effector of Fyn signaling and a potential translational target. Supported by ORIP (R24OD020166).
Temperature-Dependent Alterations in the Proteome of the Emergent Fish Pathogen Edwardsiella piscicida
Jacobsen et al., Journal of Fish Diseases. 2024.
https://pubmed.ncbi.nlm.nih.gov/39304982
Reported outbreaks of Edwardsiella piscicida, a bacterial pathogen among cultured and wild fish, have been steadily increasing over the past decade in tandem with climate change–mediated increases in water temperatures. The capacity for this increasingly prevalent fish pathogen to infect and cause disease in mammals is important to understand. Researchers examined the role of temperature on the virulence of E. piscicida to understand its pathogenesis in the context of climate warming trends and better understand its zoonotic potential. Findings revealed downregulation of virulence-related proteins, such as flagellar and Type VI secretion system proteins, at colder temperatures. These findings highlight the potential environmental factors influencing the pathogen’s threat to aquaculture and public health. Supported by ORIP (S10OD026918, T32OD011147).
The Splicing Factor hnRNPL Demonstrates Conserved Myocardial Regulation Across Species and Is Altered in Heart Failure
Draper et al., FEBS Letters. 2024.
https://pubmed.ncbi.nlm.nih.gov/39300280/
The 5-year mortality rate of heart failure (HF) is approximately 50%. Gene splicing, induced by splice factors, is a post-transcriptional modification of mRNA that may regulate pathological remodeling in HF. Researchers investigated the role of the splice factor heterogenous nuclear ribonucleoprotein-L (hnRNPL) in cardiomyopathy. hnRNPL protein expression is significantly increased in a male C57BL/6 transaortic constriction–induced HF mouse model and in clinical samples derived from canine or human HF patients. Cardiac-restricted knockdown of the hnRNPL homolog in Drosophila revealed systolic dysfunction and reduced life span. This study demonstrates a conserved cross-species role of hnRNPL in regulating heart function. Supported by ORIP (K01OD028205) and NHLBI.
A New Atlas to Study Embryonic Cell Types in Xenopus
Petrova et al., Developmental Biology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38614285
Petrova et al. have designed a new single-cell atlas for developmental stages in Xenopus tropicalis that encompasses gastrulation, neurulation, and early tail bud. Compared to its predecessors, the new atlas enhances gene mapping, read counts, and gene/cell-type nomenclature. The atlas also leverages the latest X. tropicalis genome version to maintain consistency with previous cell-type annotations while rectifying prior nomenclature issues. The new resource emphasizes previously unexplored germ-cell populations in which novel transcription onset features have been uncovered. Finally, the new atlas offers interactive exploration through a user-friendly web portal and allows users to download complete data sets. Supported by ORIP (R24OD031956).
Cdk8/CDK19 Promotes Mitochondrial Fission Through Drp1 Phosphorylation and Can Phenotypically Suppress Pink1 Deficiency in Drosophila
Liao et al., Nature Communications. 2024.
https://www.nature.com/articles/s41467-024-47623-8
Pink1 is a mitochondrial kinase implicated in Parkinson’s disease and is conserved among humans, rodents, and flies. In this study, researchers found that Cdk8 in Drosophila (i.e., the orthologue of vertebrate CDK8 and CDK19) promotes the phosphorylation of Drp1 (i.e., a protein required for mitochondrial fission) at the same residue as Pink1. Cdk8 is expressed in both the cytoplasm and nucleus, and neuronal loss of Cdk8 reduces fly life span and causes bang sensitivity and elongated mitochondria in both muscles and neurons. Overexpression of Cdk8 suppresses elevated levels of reactive oxygen species, mitochondrial dysmorphology, and behavioral defects in flies with low levels of Pink1. These findings suggest that Cdk8 regulates Drp1-mediated mitochondrial fission in a similar manner as Pink1 and may contribute to the development of Parkinson’s disease. Supported by ORIP (R24OD022005, R24OD031447, P40OD018537, P40OD010949), NICHD, and NINDS.
Identifying Potential Dietary Treatments for Inherited Metabolic Disorders Using Drosophila Nutrigenomics
Martelli et al., Cell Reports. 2024.
https://www.sciencedirect.com/science/article/pii/S221112472400189X?via%3Dihub=
Inherited metabolic disorders are known to cause severe neurological impairment and child mortality and can sometimes respond to dietary treatment; however, a suitable paradigm for testing diets is lacking for developing effective dietary treatment. In this study, researchers found that 26 of 35 Drosophila amino acid disorder models screened for disease–diet interactions displayed diet-altered development and/or survival. Among these models, researchers showed that dietary cysteine depletion normalizes metabolic profile and rescues development, neurophysiology, behavior, and life span in a model for isolated sulfite oxidase deficiency. These findings demonstrate the value of using Drosophila in studying diet-sensitive metabolic disorders and developing potential dietary therapies. Supported by ORIP (R24OD031447) and NHGRI.
De Novo Variants in FRYL Are Associated With Developmental Delay, Intellectual Disability, and Dysmorphic Features
Pan et al., The American Journal of Human Genetics. 2024.
https://www.cell.com/ajhg/fulltext/S0002-9297(24)00039-9
FRY-like transcription coactivator (FRYL) belongs to a Furry protein family that is evolutionarily conserved from yeast to humans, and its functions in mammals are largely unknown. Investigators report 13 individuals who have de novo heterozygous variants in FRYL and one individual with a heterozygous FRYL variant that is not confirmed to be de novo. The individuals present with developmental delay; intellectual disability; dysmorphic features; and other congenital anomalies in cardiovascular, skeletal, gastrointestinal, renal, and urogenital systems. Using fruit flies, investigators provide evidence that haploinsufficiency in FRYL likely underlies a disorder in humans with developmental and neurological symptoms. Supported by ORIP (U54OD030165), NHLBI, NICHD, and NCATS.
Age-Associated DNA Methylation Changes in Xenopus Frogs
Morselli et al., Epigenetics. 2023.
https://www.tandfonline.com/doi/full/10.1080/15592294.2023.2201517
Age-associated changes in DNA methylation have not been characterized yet in amphibians, which include widely studied model organisms. Here the authors present clear evidence that the aquatic vertebrate species Xenopus tropicalis displays patterns of age-associated changes in DNA methylation. Whole-genome bisulfite sequencing profiles from skin samples of frogs representing young, mature, and old adults demonstrated that many of the methylation features and changes they observed are consistent with what is known in mammalian species, suggesting that the mechanism of age-related changes is conserved. The results of this study will allow researchers to leverage the unique resources available for Xenopus to study how DNA methylation relates to other hallmarks of aging. Supported by ORIP (P40OD010997, R24OD031956, R24OD030008) and NICHD.
Allelic Strengths of Encephalopathy-Associated UBA5 Variants Correlate Between In Vivo and In Vitro Assays
Pan et al., eLife. 2023.
https://pubmed.ncbi.nlm.nih.gov/37502976/
The UBA5 gene is associated with developmental and epileptic encephalopathy 44 (DEE44), an autosomal recessive disorder, in humans. The link between UBA5 variants and severity of DEE44, however, is not established. Investigators developed humanized fly models carrying a series of patient UBA5 variants. These flies showed differences in survival rates, developmental progress, life span, and neurological well-being. The severity of these defects correlated strongly with functional defects of UBA5 variants, allowing the classification of UBA5 loss-of-function variants into mild, intermediate, and severe allelic strengths in patients. This study provides resources for systematic investigation of the mechanistic link between UBA5 variants and DEE44 and for developing diagnostic approaches. Supported by ORIP (R24OD022005, R24OD031447, U54OD035865) and NCATS.