Disruptions to the maternally inherited allele UBE3A, encoding for an E3 ubiquitin ligase, leads to the manifestation of Angelman Syndrome (AS). While this disorder is rare, the symptoms are severe and lifelong including but not limited to: intractable seizures, abnormal EEG's, ataxic gait, lack of speech, and most notably an abnormally happy demeanor with easily provoked laughter. Currently, little is known about the neurophysiological underpinnings of UBE3A leading to such globally severe phenotypes. Utilizing the newest AS rat model, comprised of a full UBE3A deletion, we aimed to elucidate novel mechanistic actions and potential therapeutic targets. This report demonstrates for the first time that catalytically active UBE3A protein is detectable within cerebrospinal fluid (CSF) of wild type rats but distinctly absent in AS rat CSF. Microdialysis within the rat hippocampus also showed that UBE3A protein is located in the interstitial fluid of wild type rat brains but absent in AS animals. This protein maintains catalytic activity and appears to be regulated in a dynamic activity‐dependent manner. Lay Summary Angelman syndrome (AS) is a rare genetic disorder caused by the loss of the UBE3A gene within the central nervous system. Although we have identified the gene responsible for AS, we still have a long way to go to fully understand its function in vivo. Here we report that UBE3A is present within normal cerebrospinal fluid (CSF) but distinctly absent in AS CSF. Furthermore, we demonstrate that UBE3A is secreted and that this may occur in a dynamic activity‐dependent fashion. Extracellular UBE3A maintained its ubiquitinating activity, thus suggesting that UBE3A may have a novel role outside of neurons. Autism Res 2021, 14: 645–655. © 2021 International Society for Autism Research and Wiley Periodicals LLC

Diabetic cardiomyopathy (DCM) is characterized by microvascular pathology and interstitial fibrosis that leads to progressive heart failure. The mechanisms underlying DCM pathogenesis remain obscure, and no effective treatments for the disease have been available. In the present study, we observed that STK35, a novel kinase, is decreased in the diabetic human heart. High glucose treatment, mimicking hyperglycemia in diabetes, downregulated STK35 expression in mouse cardiac endothelial cells (MCEC). Knockdown of STK35 attenuated MCEC proliferation, migration, and tube formation, whereas STK35 overexpression restored the high glucose-suppressed MCEC migration and tube formation. Angiogenesis gene PCR array analysis revealed that HG downregulated the expression of several angiogenic genes, and this suppression was fully restored by STK35 overexpression. Intravenous injection of AAV9-STK35 viral particles successfully overexpressed STK35 in diabetic mouse hearts, leading to increased vascular density, suppression of fibrosis in the heart, and amelioration of left ventricular function. Altogether, our results suggest that hyperglycemia downregulates endothelial STK35 expression, leading to microvascular dysfunction in diabetic hearts, representing a novel mechanism underlying DCM pathogenesis. Our study also emerges STK35 is a novel gene therapeutic target for preventing and treating DCM.

Diabetic cardiomyopathy is a common complication in patients with diabetes and is associatedwith impaired responsiveness of ischemic myocardium to proangiogenic factors, subsequentlyleading to heart failure. STK35, a novel kinase that binds to nuclear actin, has been shown toregulate important cellular functions such as cell migration, proliferation, survival, andangiogenesis. Currently, the contribution of altered STK35 expression in human diseases remainsunexplored. In initial studies, we observed that human cardiac biopsies from diabetic patientsshowed a significant decrease in STK35 expression as compared to non-diabetic control hearts.Intriguingly, in a STZ-induced mouse model of diabetes, i.v . injection of rAAV9-STK35 to expressconstitutive STK35 in heart in FVB/N male mice promoted neovascularization and lowered cardiacfibrosis, leading to improved cardiac function of diabetic heart. Our in vitro studies observed highglucose decreased STK35 expression in mouse cardiac endothelial cells (MCEC), whereasSTK35 overexpression increased MCEC migration and vascular tube formation, and upregulatedMCEC to expression of multiple pro-angiogenic proteins. Taken together, our results demonstratethat cardiac-targeted STK35 gene therapy exerts a marked beneficial action by attenuating bothcardiac remodeling and cardiac function in a mouse model of diabetes mellitus. Mechanistically,the beneficial effect may be attributed, at least partially, to enhanced neovascularization in heart.

Background Alzheimer’s disease (AD) is characterized clinically by progressive cognitive decline, eventually resulting in death, usually within 10 years of diagnosis. Abnormal tau hyperphosphorylation and its accumulation into neurofibrillary tangles are linked to neurodegeneration in Alzheimer’s disease and similar tauopathies. Aberrant motor behaviors such as pacing/wandering are common in AD. Some AD cases have metabolic changes resulting in weight loss in spite of increased food consumption. Tg4510 mice are characterized by tau deposition in the brain together with cognitive and non‐cognitive impairments that resemble those seen in patients. Leviteracetam is an FDA approved drug that has shown cognitive improvements in mice models of amyloid deposition. The aim of this study was to test the effects of a Leviteracetam diet on cognitive and non‐cognitive impairments in a mouse model of tauopathy, the Tg4510 mice. Method Three‐month old Tg4510 transgenic and non‐transgenic littermate mice were equally randomly assigned to treated (food containing 240mg/kg Levetiracetam) or placebo (normal diet) groups (n=10, 5F & 5M). All mice were single housed, and food intake and mice body weight were recorded once a week for 3 months. During the last 2 weeks before tissue collection the following behavioral tests were performed: open field, Y‐maze, marble burying, RAWM with reversal, rotarod, novel object recognition (NOR) and fear conditioning. On the last day, the brain was dissected, blood sample was collected, and muscle mass, white fat, and brown fat were weighed. Result Treatment with Leviteracetam did not improve cognition or activity in Tg4510 during RAWM, open field, and fear conditioning tests. Although Leviteracetam improved performance during rotarod and reduced body weight in non‐transgenic littermates, such effects were not seen in Tg4510 mice. Conclusion There were no significant improvements in cognitive and non‐cognitive deficits in Tg4510 mice treated with Levetiracetam. Interestingly, Leviteracetam diet resulted in a decrease in body weight together with improvement in rotarod in non‐transgenic littermates when compared to chow diet, whereas no effects were observed in Tg4510 mice treated with leviteracetam. Biochemical and histochemical analysis will be performed in brain tissue to know if treatment with Levetiracetam had an effect on tau pathology.