2017 ACVIM Forum Research Abstract Program

Samples stored in VetStarch TM and fetal calf serum exhibited improved morphology scores, median 2.46 (1.42-3.20) and 2.25 (1.13-3.33), respectively, as compared to those in stored in saline, 3.0 (1.14-4.00 This study was performed to identify the mutation causing a progressive neurodegenerative disease in Shiba Inu dogs with storage body autofluorescence. Two related Shiba Inu dogs were suspected to have neuronal ceroid lipofuscinosis (NCL) based on clinical signs, antemortem diagnostics, disease progression and autofluorescence of storage material on histopathology. A whole genome sequence (WGS) was generated with DNA from one affected dog using previously described techniques. The data were screened for potentially causal mutations in known NCL genes but no candidate variants were found. However, the WGS contained a novel homozygous deletion of a conserved codon in the HEXB gene (which encodes the beta subunit of beta-hexosaminidase). The deletion was not found in the WGS from 105 unaffected dogs of various breeds. The other affected Shiba Inu was also homozygous for this variant. Mutations in HEXB have been implicated in GM2 gangliosidosis (Sandhoff disease) in humans and in other dog breeds. Beta-hexosaminidase activity was measured in brain tissue from one of the affected dogs using previously described synthetic substrates. Activity against two different substrates was markedly reduced compared to a normal dog, consistent with Sandhoff-like disease (HEXB deficiency). Thus, we conclude that the HEXB mutation in these dogs caused GM2 gangliosidosis and led to their clinical signs. To our knowledge, this is the first report that GM2 gangliosidosis-associated storage material is autofluorescent. This study also demonstrates the utility of WGS for the efficient diagnosis of potentially heritable diseases in veterinary medicine by identifying a mutation that abolishes HEXB activity in Shiba Inu dogs. Easily accessible, validated biomarkers for gliomas are needed to aid in diagnosis and therapeutic monitoring. Exosomes are extracellular membranous vesicles (30-100 nm) that are released by cells into the microenvironment and may carry signatures of the cell of origin. We hypothesized that integrin targeting cyclic nonapeptides (LXW7/avb3, LXY30/a3b1) derived from screening of human and canine glioma cells would identify canine glioma cell lines and cell line derived exosomes in vitro.