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Glucocerebrosidase is a lysosomal hydrolase involved in the breakdown of glucosylceramide. Gaucher disease, a recessive lysosomal storage disorder, is caused by mutations in the gene GBA1. Dysfunctional glucocerebrosidase leads to accumulation of glucosylceramide and glycosylsphingosine in various cell types and organs. Mutations in GBA1 are also a common genetic risk factor for Parkinson disease and related synucleinopathies. In recent years, research on the pathophysiology of Gaucher disease, the molecular link between Gaucher and Parkinson disease, and novel therapeutics, have accelerated the need for relevant cell models with GBA1 mutations. Although induced pluripotent stem cells, primary rodent neurons, and transfected neuroblastoma cell lines have been used to study the effect of glucocerebrosidase deficiency on neuronal function, these models have limitations because of challenges in culturing and propagating the cells, low yield, and the introduction of exogenous mutant GBA1. To address some of these difficulties, we established a high yield, easy-to-culture mouse neuronal cell model with nearly complete glucocerebrosidase deficiency representative of Gaucher disease. We successfully immortalized cortical neurons from embryonic null allele gba−/− mice and the control littermate (gba+/+) by infecting differentiated primary cortical neurons in culture with an EF1α-SV40T lentivirus. Immortalized gba−/− neurons lack glucocerebrosidase protein and enzyme activity, and exhibit a dramatic increase in glucosylceramide and glucosylsphingosine accumulation, enlarged lysosomes, and an impaired ATP-dependent calcium-influx response; these phenotypical characteristics were absent in gba+/+ neurons. This null allele gba−/− mouse neuronal model provides a much-needed tool to study the pathophysiology of Gaucher disease and to evaluate new therapies.

Abstract Objective  Intramedullary spinal cord tumors (IMSCT) pose significant challenges given their recurrence rate and limited treatment options. Using our previously described rat model of IMSCT, we describe a technique for microsurgical tumor resection and present the functional and histopathological analysis of tumor progression. Methods  Twenty-four Fischer 344 rats were randomized into two groups. All animals received a 5-μl intramedullary injection of 9L gliosarcoma cells. Animals were evaluated daily for signs of paralysis using the Basso, Beattie, and Bresnahan (BBB) scale. Group 1 continued with daily assessments using the BBB scale following tumor implantation, but received no further treatment. Group 2 underwent surgical removal of intramedullary tumor on postoperative day five. At a BBB score less than 5 (e.g., functional paraplegia), all animals of both groups were killed and sent for histopathological analysis. Results  Group 1 had a median onset of functional hind limb paraplegia at 15 ± 1.0 days. Group 2 had a median onset of hind limb paresis at 53 ± 0.46 days. Hematoxylin–eosin cross-sections confirmed the presence of intramedullary 9L tumor invading the spinal cord in both groups. Conclusion  Animals with 9L IMSCTs consistently developed hind limb paraplegia in a reliable and reproducible manner. Animals undergoing microsurgical resection of IMSCT had a significant delay in the onset of functional paraplegia compared to the untreated controls. These findings suggest that this model may mimic the behavior of IMSCTs following operative resection in humans and thus may be used to examine efficacy of new treatment options for high-grade intramedullary tumors. [ABSTRACT FROM AUTHOR]