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Cain, J. T.

Publications and source records attributed to Cain, J. T..

5 recordsLinked to original sources

A CLN6-CRMP2-KLC4 complex regulates anterograde ER-derived vesicle trafficking in cortical neurites

As neurons establish extensive connections throughout the central nervous system, the transport of cargo along the microtubule network of the axon is crucial for differentiation and homeostasis. Specifically, building blocks such as membrane and cytoskeletal components, organelles, transmembrane receptors, adhesion molecules, and peptide neurotransmitters all require proper transport to the presynaptic compartment. Here, we identify a novel complex regulating vesicular endoplasmic reticulum transport in neurites, composed of CLN6: an ER-associated protein of relatively unknown function implicated in CLN6-Batten disease; CRMP2: a tubulin binding protein important in regulating neurite microtubule dynamics; and KLC4: a classic transport motor protein. We show that this "CCK" complex allows ER-derived vesicles to migrate to the distal end of the axon, aiding in proper neurite outgrowth and arborization. In the absence of CLN6, the CCK complex does not function effectively, leading to reduced vesicular transport, stunted neurite outgrowth, and deficits in CRMP2 binding to other protein partners. Treatment with a CRMP2 modulating compound, lanthionine ketimine ester, partially restores these deficits in CLN6-deficient mouse neurons, indicating that stabilization of CRMP2 interacting partners may prove beneficial in lieu of complete restoration of the CCK complex. Taken together, these findings reveal a novel mechanism of ER-derived vesicle transport in the axon and provide new insights into therapeutic targets for neurodegenerative disease.

neuroscience↗

Transmembrane Batten disease proteins interact with a shared network of vesicle sorting proteins to regulate synaptic composition and function.

Batten disease is unique among lysosomal storage disorders for the early and profound manifestation in the central nervous system, but little is known regarding potential neuron-specific roles for the disease-associated proteins. We demonstrate substantial overlap in the protein interactomes of three transmembrane Batten proteins (CLN3, CLN6, and CLN8), and that their absence leads to synaptic depletion of key partners (i.e. SNAREs and tethers) and aberrant synaptic SNARE dynamics in vivo, demonstrating a novel shared etiology.

neuroscience↗

AAV9 gene therapy restores lifespan and treats pathological and behavioral abnormalities in a mouse model of CLN8-Batten disease

CLN8 disease is a rare form of neuronal ceroid lipofuscinosis caused by biallelic mutations in the CLN8 gene, which encodes a transmembrane endoplasmic reticulum protein involved in trafficking of lysosomal enzymes. CLN8 disease patients present with myoclonus, tonic-clonic seizures, and progressive declines in cognitive and motor function, with many cases resulting in premature death early in life. There are currently no treatments that can cure the disease or substantially slow disease progression. Using a mouse model of CLN8 disease, we tested the safety and efficacy of an intracerebroventricularly (ICV)-delivered self-complementary AAV9 (scAAV9) gene therapy vector driving expression of human CLN8. A single neonatal injection was safe and well-tolerated, resulting in robust transgene expression throughout the brain and spinal cord from 4 to 24 months, reducing histopathological and behavioral hallmarks of the disease and completely restoring lifespan from 10 months in untreated animals to beyond 24 months of age in treated animals. These results demonstrate, by far, the most successful rescue reported in an animal model of CLN8 disease, and supports gene therapy as a promising therapeutic strategy for this disorder.

neuroscience↗

A multimodal approach to identify clinically relevant parameters to monitor disease progression in a preclinical model of neuropediatric disease

While research has accelerated the development of new treatments for pediatric neurodegenerative disorders, the ability to demonstrate the long-term efficacy of these therapies has been hindered by the lack of convincing, noninvasive methods for tracking disease progression both in animal models and in human clinical trials. Here, we unveil a new translational platform for tracking disease progression in an animal model of a pediatric neurodegenerative disorder, CLN6-Batten disease. Instead of looking at a handful of parameters or a single \"needle in a haystack\", we embrace the idea that disease progression, in mice and patients alike, is a diverse phenomenon best characterized by a combination of relevant biomarkers. Thus, we employed a multi-modal quantitative approach where 144 parameters were longitudinally monitored to allow for individual variability. We use a range of noninvasive neuroimaging modalities and kinematic gait analysis, all methods that parallel those commonly used in the clinic, followed by a powerful statistical platform to identify key progressive anatomical and metabolic changes that correlate strongly with the progression of pathological and behavioral deficits. This innovative, highly sensitive platform can be used as a powerful tool for preclinical studies on neurodegenerative diseases, and provides proof-of-principle for use as a potentially translatable tool for clinicians in the future.\n\nOne Sentence SummaryPrincipal component analysis identifies a set of clinically relevant parameters able to measure progression of Batten disease in a mouse model.

pathology↗

Cancer exosomes induce tumor neo-neurogenesis potentiating tumor growth

Patients with densely innervated tumors do worse than those with less innervated cancers. We hypothesize that neural elements are acquired by a tumor-induced process, called neo-neurogenesis. Here, we use PC12 cells in a simple system to test this hypothesis. PC12 cells extend processes, called neurites, only when appropriately stimulated. Using this system, we show that patient tumors release vesicles (exosomes) which induce PC12 neurite outgrowth. Using a cancer mouse model, we show that tumor cells compromised in exosome release grow slower and are less innervated than controls indicating a contribution of innervation to disease progression. We find that neo-neurogenesis is mediated in part by the axonal guidance molecule, EphrinB1, contained in exosomes. These findings support testing EphrinB1 blockers to inhibit tumor innervation and improve survival.\n\nOne Sentence SummaryTumors release exosomes which not only promote their own innervation but also potentiate their growth.

cancer biology↗