Efficacy of dual intracerebroventricular and intravitreal CLN5 gene therapy in sheep prompts the first clinical trial to treat CLN5 Batten disease

Mutations in the CLN5 gene cause the fatal, pediatric, neurodegenerative disease CLN5 neuronal ceroid lipofuscinosis. Affected children suffer progressive neuronal loss, visual failure and premature death. Presently there is no treatment. This study evaluated dual intracerebroventricular (ICV) and intravitreal (IVT) administration of a self-complementary adeno-associated viral vector encoding ovine CLN5 (scAAV9/oCLN5) into CLN5 affected sheep (CLN5-/-) at various disease stages. CLN5 disease progression was slowed in pre-symptomatic sheep who received a moderate dose of scAAV9/oCLN5, whilst a higher ICV dose treatment in early and advanced symptomatic animals delayed or halted disease progression. Intracranial (brain) volume loss was attenuated in all treatment cohorts, and visual function was also sustained in both the early and advanced symptomatic treated sheep over the 24-month duration of the study. Robust CLN5 protein expression was detected throughout the brain and spinal cord, and improvements in central nervous system and retinal disease correlates were observed. These findings hold translational promise for extending and improving the quality of life in both pre-symptomatic and symptomatic CLN5 patients, and prompted the initiation of the first in-human Phase I/II clinical trial testing ICV/IVT administration of scAAV9 encoding human CLN5 (https://clinicaltrials.gov/; NCT05228145).

Long-term safety and dose escalation of intracerebroventricular CLN5 gene therapy in sheep supports clinical translation for CLN5 Batten disease

CLN5 neuronal ceroid lipofuscinosis (NCL, Batten disease) is a rare, inherited fatal neurodegenerative disorder caused by mutations in the CLN5 gene. The disease is characterised by progressive neuronal loss, blindness, and premature death. There is no cure. This study evaluated the efficacy of intracerebroventricular (ICV) delivery of an adeno-associated viral vector encoding ovine CLN5 (scAAV9/oCLN5) in a naturally occurring sheep model of CLN5 disease. CLN5 affected (CLN5-/-) sheep received low, moderate, or high doses of scAAV9/oCLN5 at three disease stages. The treatment delayed disease progression, extended survival and slowed stereotypical brain atrophy in most animals. Of note, one high dose treated animal only developed mild disease symptomology and survived to 60.1 months of age, triple the natural life expectancy of an untreated CLN5-/- sheep. Eyesight was not preserved at any administration age or dosage. Histopathologic examination revealed that greater transduction efficiency was achieved through higher ICV doses, and this resulted in greater amelioration of disease pathology. Together with other pre-clinical data from CLN5-/- sheep, the safety and efficacy data from these investigational new drug (IND)-enabling studies supported the initiation of the first in-human CLN5 gene therapy clinical study using the ICV delivery route for the treatment of CLN5 NCL. Clinical Trial Registration: https://clinicaltrials.gov/, identifier NCT05228145.

Cognitive and arginine metabolic correlates of temporal dysfunction in the MIA rat model of schizophrenia risk

As a hallmark characteristic of schizophrenia, abnormal perception of time is thought to arise from cognitive impairment; however, the absence of translational models indexing this pathological relationship creates barriers to understanding the functional and biological bases of timing impairments. Here, we investigate the relationship between timing and cognition using the maternal immune activation (MIA) rat model of schizophrenia. We additionally investigate the role of prefrontal cortex L-arginine metabolism in these processes via high-performance liquid chromatography and liquid chromatography/mass spectrometry. Results revealed that MIA rats exhibit greater underestimation of interval durations (2-8 s); greater underestimation corresponded with declines in sustained attention capacity. Working memory impairments were not found to contribute to timing deficits. These findings represent the first direct identification of a timing-attention relationship within rodents and are discussed with respect to the dopamine hypothesis of temporal pace. We also found that MIA exposure altered aspects of arginine metabolism as observed in schizophrenia, and we present preliminary evidence suggesting that these changes have functional consequences for cognition. These findings support the MIA rat model as a valuable tool for future investigations exploring the biological instantiation of interrelated timing and cognitive deficits in schizophrenia. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The instrumental role of operant paradigms in translational psychiatric research: Insights from a maternal immune activation model of schizophrenia risk

Rigorous behavioral analysis is essential to the translation of research conducted using animal models of neuropsychiatric disease. Here we discuss the use of operant paradigms within our lab as a powerful approach for exploring the biobehavioral bases of disease in the maternal immune activation rat model of schizophrenia. We have investigated a range of disease features in schizophrenia including abnormal perception of time, cognition, learning, motivation, and internal state (psychosis), providing complex insights into brain and behavior. Beyond simple phenotyping, implementing sophisticated operant procedures has been effective in delineating aspects of pathological behavior, identifying interacting pathologies, and isolating contributing mechanisms of disease. We provide comment on the strengths of operant techniques to support high-quality behavioral investigations in fundamental neuropsychiatric research.

Occurrence of Rat Lungworm (Angiostrongylus cantonensis) in Invasive Coqui Frogs (Eleutherodactylus coqui) and Other Hosts in Hawaii, USA

The rat lungworm (Angiostrongylus cantonensis) has emerged as an important human and animal health concern in Hawaii, US. Although the life cycle of the parasite requires both rat and gastropod hosts, other animals acting as paratenic hosts, such as frogs and centipedes, have been identified as sources of infection. We investigated the occurrence of rat lungworm infections in potential paratenic hosts in Hawaii to provide information on how they might be involved in transmission of angiostrongyliasis. We confirmed the presence of rat lungworm in 87% (21/24) of introduced Puerto Rican coqui frogs (Eleutherodactylus coqui) in Hilo, Hawaii, by real-time PCR. Additionally, four Cuban greenhouse frogs (Eleutherodactylus planirostris), two cane toads (Rhinella marina), and three centipedes (Scolopendra subspinipes) were found to be infected. In the frogs and toads, multiple tissue types were positive, including stomach and intestine, muscle, liver, heart, and brain, indicating larval migration. We identified rat lungworm infections in frogs, toads, and centipedes in Hawaii and highlighted the lack of knowledge of the role paratenic hosts may be playing in the transmission and life cycle maintenance of rat lungworm in Hawaii.