Clinical impact and in vitro characterization of ADNP variants in pediatric patients.

BACKGROUND: Helsmoortel-Van der Aa syndrome (HVDAS) is a rare genetic disorder caused by variants in the activity-dependent neuroprotector homeobox (ADNP) gene; hence, it is also called ADNP syndrome. ADNP is a multitasking protein with the function as a transcription factor, playing a critical role in brain development. Furthermore, ADNP variants have been identified as one of the most common single-gene causes of autism spectrum disorder (ASD) and intellectual disability. METHODS: We assembled a cohort of 15 Chinese pediatric patients, identified 13 variants in the coding region of ADNP gene, and evaluated their clinical phenotypes. Additionally, we constructed the corresponding ADNP variants and performed western blotting and immunofluorescence analysis to examine their protein expression and subcellular localization in human HEK293T and SH-SY5Y cells. RESULTS: Our study conducted a thorough characterization of the clinical manifestations in 15 children with ADNP variants, and revealed a broad spectrum of symptoms including global developmental delay, intellectual disability, ASD, facial abnormalities, and other features. In vitro studies were carried out to check the expression of ADNP with identified variants. Two cases presented missense variants, while the remainder exhibited nonsense or frameshift variants, leading to truncated mutants in in vitro overexpression systems. Both overexpressed wildtype ADNP and all the different mutants were found to be confined to the nuclei in HEK293T cells; however, the distinctive pattern of nuclear bodies formed by the wildtype ADNP was either partially or entirely disrupted by the mutant proteins. Moreover, two variants of p.Y719* on the nuclear localization signal (NLS) of ADNP disrupted the nuclear expression pattern, predominantly manifesting in the cytoplasm in SH-SY5Y cells. LIMITATIONS: Our study was limited by a relatively small sample size and the absence of a longitudinal framework to monitor the progression of patient conditions over time. Additionally, we lacked in vivo evidence to further indicate the causal implications of the identified ADNP variants. CONCLUSIONS: Our study reported the first cohort of HVDAS patients in the Chinese population and provided systematic clinical presentations and laboratory examinations. Furthermore, we identified multiple genetic variants and validated them in vitro. Our findings offered valuable insights into the diverse genetic variants associated with HVDAS.

Airborne particulate matter (PM2.5) triggers cornea inflammation and pyroptosis via NLRP3 activation.

Although studies have demonstrated that fine particulate matter (PM2.5) induces ocular surface damage, PM2.5 exposure causes cornea toxicity is not entirely clear. The aim of this study is to investigate the role of the nod-like receptor family pyrin domain containing three (NLRP3) inflammasome-mediated pyroptosis in PM2.5-related corneal toxicity. Human corneal epithelial cells (HCECs) were exposed to different concentrations of PM2.5, and the cell viability, expressions of NLRP3 inflammasome mediated pyroptosis axis molecules and intracellular reactive oxygen species (ROS) formation were measured in HCECs. Animal experiments were undertaken to topically apply PM2.5 suspension to mouse eyes for three months and the pyroptosis related molecules in the mouse corneas were measured. RESULTS: Our results showed a dose-dependent decrease of HCEC viability in the PM2.5-treated cells. NLRP3 inflammasome-mediated pyroptosis axis (NLRP3, ASC, GSDMD, caspase-1, IL-1ß, and IL-18) were activated in the PM2.5-treated HCECs, accompanied by increased ROS formation. Further in vivo study confirmed the activation of this pathway in the mouse corneas exposed to PM2.5. In conclusion, this study provids novel evidence that PM2.5 induces corneal toxicity by triggering cell pyroptosis.

Local Delivery and Sustained-Release of Nitric Oxide Donor Loaded in Mesoporous Silica Particles for Efficient Treatment of Primary Open-Angle Glaucoma.

Nitric oxide (NO) donors are ideal drug candidates for reducing intraocular pressure in the treatment of glaucoma. However, poor cornea penetration, short duration of efficacy, and narrow therapeutic index of most NO donors obstruct their clinical applications in glaucoma treatment. This study reports a novel NO donor delivery system based on mesoporous silica nanoparticles that can readily overcome the above difficulties and deliver the NO-donating drug sodium nitroprusside to the target tissues (trabecular meshwork and Schlemm's canal). Mesoporous silica nanoparticles loaded with sodium nitroprusside can produce more exogenous NO and sustain higher NO concentration in animal eye models, which significantly extend the duration of intraocular pressure reduction from 3 to 48 h with only 1/40 of the dose of sodium nitroprusside solution. These findings open up the possibility of mesoporous silica nanoparticles loading sodium nitroprusside for effective management of ocular hypertension.

Improving the early screening procedure for autism spectrum disorder in young children: Experience from a community-based model in shanghai.

Most children with autism spectrum disorder (ASD) are not diagnosed until the age of 4, thus missing the opportunity for early intervention. The objective of this study was to investigate the feasibility of an early screening program for ASD applied during well-child visits in a community-based sample. The study lasted for 4 years and was divided into two stages. Stage I involved the implementation of the basic screening model in 2014. Toddlers received level 1 screening via section A of the Chinese-validated version of the Checklist for Autism in Toddlers (CHAT-23) during 18- and 24-month well-child visits in Xuhui District, Shanghai, China. Screen-positive children were referred to receive section B of the CHAT-23 for level 2 screening, and those still screen-positive were referred to undergo diagnosis and evaluation. Stage II involved the implementation of the improved screening model from 2015 to 2017 with the following modifications: (a) an added observational component in level 1 screening; (b) telephone follow-ups with the screen-positive families; and (c) dissemination of information on ASD to families. The results showed that 42 of 22,247 screened children were diagnosed with ASD. The ASD diagnosis rates were 0.1% in Stage I and 0.21% in Stage II. The screen-positive rate and the show rate of referral for level 1 screening increased by 76.92% and 58.43%, respectively, in Stage II compared to Stage I. Our results suggest that with appropriate logistic support, this two-level screening model is feasible and effective for the early screening of ASD during well-child visits. Autism Res 2018, 11: 1206-1217. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Difficulty in the timely identification of autism spectrum disorder (ASD) results in missed opportunities for many ASD children to receive early intervention. In this study, we established an early screening model for ASD among children aged 18-24 months in the community by relying on the three-level child healthcare system in China. The results showed that this model can effectively identify and diagnose ASD in children at an early age and thus enable early intervention.

The autism-related gene SNRPN regulates cortical and spine development via controlling nuclear receptor Nr4a1.

The small nuclear ribonucleoprotein polypeptide N (SNRPN) gene, encoding the RNA-associated SmN protein, duplications or deletions of which are strongly associated with neurodevelopmental disabilities. SNRPN-coding protein is highly expressed in the brain. However, the role of SNRPN protein in neural development remains largely unknown. Here we showed that the expression of SNRPN increased markedly during postnatal brain development. Overexpression or knockdown of SNRPN in cortical neurons impaired neurite outgrowth, neuron migration, and the distribution of dendritic spines. We found that SNRPN regulated the expression level of Nr4a1, a critical nuclear receptor during neural development, in cultured primary cortical neurons. The abnormal spine development caused by SNRPN overexpression could be fully rescued by Nr4a1 co-expression. Importantly, we found that either knockdown of Nr4a1 or 3, 3'- Diindolylmethane (DIM), an Nr4a1 antagonist, were able to rescue the effects of SNRPN knockdown on neurite outgrowth of embryonic cortical neurons, providing the potential therapeutic methods for SNRPN deletion disorders. We thus concluded that maintaining the proper level of SNRPN is critical in cortical neurodevelopment. Finally, Nr4a1 may serve as a potential drug target for SNRPN-related neurodevelopmental disabilities, including Prader-Willi syndrome (PWS) and autism spectrum disorders (ASDs).