Monday, July 17, 2017

Fly research and neurodegenerative diseases

Research articles related to ALS and Alzheimer's disease

Baldwin KR, Godena VK, Hewitt VL, Whitworth AJ. Axonal transport defects are a common phenotype in Drosophila models of ALS. Hum Mol Genet. 2016 Jun 15;25(12):2378-2392. Epub 2016 Apr 7. PMID: 27056981; PMCID: PMC5181624.

From the abstract: "Amyotrophic lateral sclerosis (ALS) is characterized by the degeneration of motor neurons resulting in a catastrophic loss of motor function. Current therapies are severely limited owing to a poor mechanistic understanding of the pathobiology. Mutations in a large number of genes have now been linked to ALS, including SOD1, TARDBP (TDP-43), FUS and C9orf72. Functional analyses of these genes and their pathogenic mutations have provided great insights into the underlying disease mechanisms. Defective axonal transport is hypothesized to be a key factor in the selective vulnerability of motor nerves ... Here, we assessed the axonal transport of different cargos in multiple Drosophila models of ALS. ... These results further support defects in axonal transport as a common factor in models of ALS that may contribute to the pathogenic process."

Bernstein AI, Lin Y, Street RC, Lin L, Dai Q, Yu L, Bao H, Gearing M, Lah JJ, Nelson PT, He C, Levey AI, Mullé JG, Duan R, Jin P. 5-Hydroxymethylation-associated epigenetic modifiers of Alzheimer's disease modulate Tau-induced neurotoxicity. Hum Mol Genet. 2016 Jun 15;25(12):2437-2450. PMID: 27060332; PMCID: PMC5181627.

From the abstract: "Alzheimer's disease (AD) is a chronic neurodegenerative disorder characterized by progressive deterioration of cognitive function. Pathogenesis of AD is incompletely understood; evidence suggests a role for epigenetic regulation, in particular the cytosine modifications 5-methylcytosine and 5-hydroxymethylcytosine (5hmC). 5hmC is enriched in the nervous system and displays neurodevelopment and age-related changes. To determine the role of 5hmC in AD, we performed genome-wide analyses of 5hmC in DNA from prefrontal cortex of post-mortem AD patients, and RNA-Seq to correlate changes in 5hmC with transcriptional changes. We identified 325 genes containing differentially hydroxymethylated loci (DhMLs) in both discovery and replication datasets. ... Finally, using an existing AD fly model, we showed some of these genes modulate AD-associated toxicity. ..."

And a review related to Parkinson's disease

Voigt A, Berlemann LA, Winklhofer KF. The mitochondrial kinase PINK1: functions beyond mitophagy. J Neurochem. 2016 Oct;139 Suppl 1:232-239. PMID: 27251035.

From the abstract: "Mutations in the genes encoding the mitochondrial kinase PINK1 and the E3 ubiquitin ligase Parkin cause autosomal recessive Parkinson's disease (PD). Pioneering work in Drosophila melanogaster revealed that the loss of PINK1 or Parkin function causes similar phenotypes including dysfunctional mitochondria. Further research showed that PINK1 can act upstream of Parkin in a mitochondrial quality control pathway to induce removal of damaged mitochondria in a process called mitophagy. ... In this review, we summarize and discuss the functional roles of PINK1 in maintaining mitochondrial integrity, eliminating damaged mitochondria, and promoting cell survival. This article is part of a special issue on Parkinson disease."

Fly research & heart disease -- a review

Ma L. Can the Drosophila model help in paving the way for translational medicine in heart failure? Biochem Soc Trans. 2016 Oct 15;44(5):1549-1560. Review. PMID: 27911738.

Wednesday, July 12, 2017

No internal skeleton? No problem. The fly grainyhead gene informs our understanding of craniofacial defects

Carpinelli MR, de Vries ME, Jane SM, Dworkin S. Grainyhead-like Transcription Factors in Craniofacial Development. J Dent Res. 2017 Jul 1:22034517719264. PMID: 28697314.

The abstract: "Craniofacial development in vertebrates involves the coordinated growth, migration, and fusion of several facial prominences during embryogenesis, processes governed by strict genetic and molecular controls. A failure in any of the precise spatiotemporal sequences of events leading to prominence fusion often leads to anomalous facial, skull, and jaw formation-conditions termed craniofacial defects (CFDs). Affecting approximately 0.1% to 0.3% of live births, CFDs are a highly heterogeneous class of developmental anomalies, which are often underpinned by genetic mutations. Therefore, identifying novel disease-causing mutations in genes that regulate craniofacial development is a critical prerequisite to develop new preventive or therapeutic measures. The Grainyhead-like (GRHL) transcription factors are one such gene family, performing evolutionarily conserved roles in craniofacial patterning. The antecedent member of this family, Drosophila grainyhead (grh), is required for head skeleton development in fruit flies, loss or mutation of Grhl family members in mouse and zebrafish models leads to defects of both maxilla and mandible, and recently, mutations in human GRHL3 have been shown to cause or contribute to both syndromic (Van Der Woude syndrome) and nonsyndromic palatal clefts. In this review, we summarize the current knowledge regarding the craniofacial-specific function of the Grainyhead-like family in multiple model species, identify some of the major target genes regulated by the Grhl transcription factors in craniofacial patterning, and, by examining animal models, draw inferences as to how these data will inform the likely roles of GRHL factors in human CFDs comprising palatal clefting. By understanding the molecular networks regulated by Grhl2 and Grhl3 target genes in other systems, we can propose likely pathways that mediate the effects of these transcription factors in human palatogenesis."

Monday, July 10, 2017

Metal-related diseases studied using Drosophila

Calap-Quintana P, González-Fernández J, Sebastiá-Ortega N, Llorens JV, Moltó MD. Drosophila melanogaster Models of Metal-Related Human Diseases and Metal Toxicity. Int J Mol Sci. 2017 Jul 6;18(7). pii: E1456. PMID: 28684721.

From the abstract: "Iron, copper and zinc are transition metals essential for life ... Organisms have evolved to acquire metals from nutrition and to maintain adequate levels of each metal to avoid damaging effects associated with its deficiency, excess or misplacement. ... many orthologues of the human metal-related genes having been identified and characterized in Drosophila melanogaster. Drosophila has gained appreciation as a useful model for studying human diseases, including those caused by mutations in pathways controlling cellular metal homeostasis. ... This review recapitulates the metabolism of the principal transition metals, namely iron, zinc and copper, in Drosophila and the utility of this organism as an experimental model to explore the role of metal dyshomeostasis in different human diseases. Finally, a summary of the contribution of Drosophila as a model for testing metal toxicity is provided."