Our findings suggest that de novo Arg87 variants in CYFIP2 have gain-of-function effects on the WAVE signaling pathway and are associated with severe neurological disorders. Ann Neurol 2018;83:794-806.

Vacuolar H+-ATPases (V-ATPases) transport protons across cellular membranes to acidify various organelles. ATP6V0A1 encodes the a1-subunit of the V0 domain of V-ATPases, which is strongly expressed in neurons. However, its role in brain development is unknown. Here we report four individuals with developmental and epileptic encephalopathy with ATP6V0A1 variants: two individuals with a de novo missense variant (R741Q) and the other two individuals with biallelic variants comprising one almost complete loss-of-function variant and one missense variant (A512P and N534D). Lysosomal acidification is significantly impaired in cell lines expressing three missense ATP6V0A1 mutants. Homozygous mutant mice harboring human R741Q (Atp6v0a1R741Q) and A512P (Atp6v0a1A512P) variants show embryonic lethality and early postnatal mortality, respectively, suggesting that R741Q affects V-ATPase function more severely. Lysosomal dysfunction resulting in cell death, accumulated autophagosomes and lysosomes, reduced mTORC1 signaling and synaptic connectivity, and lowered neurotransmitter contents of synaptic vesicles are observed in the brains of Atp6v0a1A512P/A512P mice. These findings demonstrate the essential roles of ATP6V0A1/Atp6v0a1 in neuronal development in terms of integrity and connectivity of neurons in both humans and mice.

By whole exome sequencing, we identified three de novo RHOBTB2 variants in three patients with epileptic encephalopathies (EEs). Interestingly, all three patients showed acute encephalopathy (febrile status epilepticus), with magnetic resonance imaging revealing hemisphere swelling or reduced diffusion in various brain regions. RHOBTB2 encodes Rho-related BTB domain-containing protein 2, an atypical Rho GTPase that is a substrate-specific adaptor or itself is a substrate for the Cullin-3 (CUL3)-based ubiquitin ligase complex. Transient expression experiments in Neuro-2a cells revealed that mutant RHOBTB2 was more abundant than wild-type RHOBTB2. Coexpression of CUL3 with RHOBTB2 decreased the level of wild-type RHOBTB2 but not the level of any of the three mutants, indicating impaired CUL3 complex-dependent degradation of the three mutants. These data indicate that RHOBTB2 variants are a rare genetic cause of EEs, in which acute encephalopathy might be a characteristic feature, and that precise regulation of RHOBTB2 levels is essential for normal brain function.

Background: Adverse side effects of currently available therapies against cancer, leads scientists to find effective compounds from natural sources. Objective: In the present study, stem-bark of Mycelia champaca is subjected to evaluate its anti-proliferative effect against Ehrlich ascites carcinoma (EAC) cells. To date, anti-proliferative effects of M. champaca bark extract against EAC cell line has not been reported elsewhere. Therefore, we intended to investigate the anti-proliferative potential of M. champaca bark extract against EAC cells in vivo. Methods: In vivo anticancer activity was evaluated against EAC cells bearing Swiss albino mice by monitoring parameters such as tumor cell proliferation, tumor weight measurement, and survival time etc. The mechanism of EAC killing was examined by observation of cell morphology and analysis the expression of certain cancer related genes. In vitro antioxidant potentiality was determined in terms of several common antioxidant assays. In addition, total phenolic and flavonoids contents were measured to insure the presence of phytochemicals. Results: M. champaca bark extract showed strong antioxidant activities which were found to be strongly correlated (P< 0.001) with phenolics and flavonoids contents. Furthermore, it was found that bark extract decreased tumor cell proliferation (77.46%; P< 0.01), tumor weight (42.13%; P< 0.001) and increased life span of tumor bearing mice (71.97%; P< 0.01) at the dose of 250mg/kg (intraperitoneal; i.p.). M. champaca bark also altered the depleted hematological parameters such as red blood cell, white blood cell, hemoglobin (Hb%) towards normal in tumor bearing mice. In addition, upregulation ofp53, Bax and downregulation Bcl-2 followed by treatmentindicated M. champacabark could induce apoptosis of EAC cells. Conclusion: These results indicated that MEMCB possesses significant cytotoxic activities against EAC cells and has a strong in vitro antioxidant capacity. Therefore, bark of M. champaca could be considered as a potential resource of anti-cancer agents, which might be used to formulate effective anticancer drugs.

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