Deficiency of FRMD5 results in neurodevelopmental dysfunction and autistic-like behavior in mice.

The pathophysiology of autism spectrum disorders (ASDs) is causally linked to postsynaptic scaffolding proteins, as evidenced by numerous large-scale genomic studies [1, 2] and in vitro and in vivo neurobiological studies of mutations in animal models [3, 4]. However, due to the distinct phenotypic and genetic heterogeneity observed in ASD patients, individual mutation genes account for only a small proportion (<2%) of cases [1, 5]. Recently, a human genetic study revealed a correlation between de novo variants in FERM domain-containing-5 (FRMD5) and neurodevelopmental abnormalities [6]. In this study, we demonstrate that deficiency of the scaffolding protein FRMD5 leads to neurodevelopmental dysfunction and ASD-like behavior in mice. FRMD5 deficiency results in morphological abnormalities in neurons and synaptic dysfunction in mice. Frmd5-deficient mice display learning and memory dysfunction, impaired social function, and increased repetitive stereotyped behavior. Mechanistically, tandem mass tag (TMT)-labeled quantitative proteomics revealed that FRMD5 deletion affects the distribution of synaptic proteins involved in the pathological process of ASD. Collectively, our findings delineate the critical role of FRMD5 in neurodevelopment and ASD pathophysiology, suggesting potential therapeutic implications for the treatment of ASD.

Somatic mutation contributing to clonal haematopoiesis is a risk factor of recurrent stroke in first-ever acute ischaemic stroke: a prospective cohort study.

BACKGROUND: Somatic mutation contributes to clonal haematopoiesis of indeterminate potential (CHIP) is related to age and associated with a higher risk of stroke and atherosclerotic cardiovascular disease. Here, we investigated the prognostic significance of CHIP in a large first-ever acute ischaemic stroke (AIS) cohort and explored the underlying mechanisms. METHODS: We studied a prospective cohort of 6016 patients who had a first-ever AIS in China. Whole-genome sequencing was performed to identify CHIP. High-sensitivity C reactive protein (hs-CRP) levels above 3 mg/L at baseline were defined as hyperinflammation. Recurrent stroke during the 3-month follow-up was the primary outcome. RESULTS: Among the 6016 patients who had a first-ever AIS, with a median age was 62 years (IQR, 54.0‒70.0), 3.70% were identified as CHIP carriers. The most common mutations occurred in the DNMT3A (30.0%) and TET2 (11.4%) genes. During a follow-up of 3 months, the presence of CHIP was associated with recurrent stroke (HR 1.62, 95% CI 1.04 to 2.51, p=0.03), recurrent ischaemic stroke (HR 1.64, 95% CI 1.04 to 2.58, p=0.03) and combined vascular events (HR 1.58, 95% CI 1.02 to 2.44, p=0.04) after adjusting for hsCRP levels at baseline in patients who had a first-ever AIS. Subgroup analysis demonstrated that CHIP was only associated with recurrent stroke when patients under hyperinflammation (OR 3.10, 95% CI 1.92 to 5.00, p<0.001) but not in those without hyperinflammation (OR 0.18, 95% CI 0.03 to 1.04, p=0.06, Pinteraction=0.002). CONCLUSION: Our results suggest that somatic mutations contributing to CHIP increase the risk of short-term recurrent stroke in patients who had a first-ever AIS. Hyperinflammation may be important in the relationship between CHIP and recurrent stroke.

Cdyl Deficiency Brakes Neuronal Excitability and Nociception through Promoting Kcnb1 Transcription in Peripheral Sensory Neurons.

Epigenetic modifications are involved in the onset, development, and maintenance of pain; however, the precise epigenetic mechanism underlying pain regulation remains elusive. Here it is reported that the epigenetic factor chromodomain Y-like (CDYL) is crucial for pain processing. Selective knockout of CDYL in sensory neurons results in decreased neuronal excitability and nociception. Moreover, CDYL facilitates histone 3 lysine 27 trimethylation (H3K27me3) deposition at the Kcnb1 intron region thus silencing voltage-gated potassium channel (Kv ) subfamily member Kv 2.1 transcription. Loss function of CDYL enhances total Kv and Kv 2.1 current density in dorsal root ganglia and knockdown of Kv 2.1 reverses the pain-related phenotypes of Cdyl deficiency mice. Furthermore, focal administration of a novel potent CDYL antagonist blunts nociception and attenuates neuropathic pain. These findings reveal that CDYL is a critical regulator of pain sensation and shed light on the development of novel analgesics targeting epigenetic mechanisms.

Research Progress on PATJ and Underlying Mechanisms Associated with Functional Outcomes After Stroke.

Cell polarity is an intrinsic property of epithelial cells regulated by scaffold proteins. The CRB (crumbs) complex is known to play a predominant role in the dynamic cooperative network of polarity scaffold proteins. PATJ (PALS1-associated tight junction) is the core component in the CRB complex and has been highly conserved throughout evolution. PATJ is crucial to several important events in organisms' survival, including embryonic development, cell polarity, and barrier establishment. A recent study shows that PATJ plays an important role in functional outcomes of stroke. In this article, we elaborate on the biological structure and physiological functions of PATJ and explore the underlying mechanisms of PATJ genetic polymorphism that are associated with poor functional outcomes in ischemic stroke.

Guideline-directed low-density lipoprotein management in high-risk ischemic stroke or transient ischemic attack admissions in China from 2015 to 2019.

BACKGROUND: Lowering low-density lipoprotein cholesterol (LDL-C) is crucial for secondary stroke prevention in stroke patients with preexisting cardiovascular diseases (CVD) or cerebrovascular diseases (CeVD). However, data on attainment of guideline-recommended LDL-C levels are lacking. METHODS: We analyzed data from the Chinese Stroke Center Alliance (CSCA) program for patients with ischemic stroke and transient ischemic attack (TIA) hospitalized between August 2015 and July 2019. Participants were classified into different disease groups according to preexisting CeVD (stroke/TIA) or CVD [coronary heart disease (CHD) or myocardial infarction (MI)]. RESULTS: Of 858,509 patients presenting with an acute stroke/TIA, 251,176 (29.3%) had a preexisting CeVD, 44,158 (5.1%) had preexisting CVD, 33,070 (3.9%) had concomitant preexisting CeVD and CVD, and 530,105 (61.7%) had no documented history of CeVD/CVD. Overall, only 397,596 (46.3%) met the target for LDL-C <2.6 mmol/L, 128,177 (14.9%) for LDL-C <1.8 mmol/L and 55,275 (6.4%) for LDL-C <1.4 mmol/L, and patients with concomitant CeVD and CVD had higher attainment rates than other disease groups (P<0.001). Despite improvements over time in the proportion of patients who attain LDL-C targets (P for trend <0.05), it remains suboptimal. Younger age, women, having a history of hypertension or dyslipidemia, current smoking or drinking, and being admitted to hospitals located in eastern China were associated with lower odds of meeting the LDL-C goals. CONCLUSIONS: Overall attainment of guideline LDL-C targets in a population of stroke/TIA patients is low and indicates the need for better management of dyslipidemia, particularly for high-risk stroke patients with pre-existing CeVD or CVD.

GRP per capita and hospital characteristics associated with intravenous tissue plasminogen activator adherence rate: evidence from the Chinese Stroke Center Alliance.

BACKGROUND: Timely delivery of intravenous tissue plasminogen activator (IV-rt PA) is pivotal to eligible patients who had a stroke while achieving higher rates of IV-rt PA has been problematic. This paper focuses on investigating influential factors associated with the administration of IV-rt PA, primarily per capita gross regional product (GRP) and healthcare system factors. METHODS: The study included 980 hospitals in the Chinese Stroke Center Alliance where 158 003 patients who had an acute ischaemic stroke received IV-rt PA between August 2015 and August 2019. The adherence rate to IV-rt PA within 4.5 hours time window in each hospital was the primary outcome. Influential factors were grouped into two categories: macroeconomic status and hospital characteristics. The outcome was analysed using multivariable linear regression. RESULTS: GRP per capita (ß=2.37, p<0.001), hospital stroke centre certification (ß=3.77, p<0.001), number of neurologists (ß=0.12, p<0.001), existence of emergency services for neurological treatment (ß=7.43, p=0.014), presence of emergency department (ß=10.03, p=0.019) and cooperating with emergency centre (ß=4.65, p=0.029) were significantly positively associated with the adherence rate to IV-rt PA. CONCLUSIONS: Higher GRP per capita, affluent neurological personnel, well-equipped emergency services for neurological treatment and routine cooperation with the emergency centre were important for enhancing the adherence rate to IV-rt PA among patients who had an acute ischaemic stroke in China.

Structural Basis for the Binding Selectivity of Human CDY Chromodomains.

The CDY (chromodomain on the Y) proteins play an essential role in normal spermatogenesis and brain development. Dysregulation of their expression has been linked to male infertility and various neurological diseases. Like the chromodomains of HP1 and Polycomb, the CDY chromodomains also recognize the lysine-methylated ARKS motif embedded in histone and non-histone proteins. Interestingly, the CDY chromodomains exhibit different binding preferences for the lysine-methylated ARKS motif in different sequence contexts. Here, we present the structural basis for selective binding of CDY1 to H3K9me3 and preferential binding of CDYL2 to H3tK27me3 over H3K27me3. In addition, we use a CDYL1/2-selective compound, UNC4850, to gain further insight into the molecular mechanisms underlying CDYL2 binding specificity. Our work also provides critical implications that CDYL1b's role in the regulation of neural development is dependent on its recognition of the lysine-methylated ARKS motif.

PLD1 promotes dendritic spine morphogenesis via activating PKD1.

Dendritic spines on the dendrites of pyramidal neurons are one of the most important components for excitatory synapses, where excitatory information exchanges and integrates. The defects of dendritic spine development have been closely connected with many nervous system diseases including autism, intellectual disability and so forth. Based on our previous studies, we here report a new functional signaling link between phospholipase D1 (PLD1) and protein kinase D1 (PKD1) in dendritic spine morphogenesis. Coimmunoprecipitation assays showed that PLD1 associates with PKD1. A series of knocking down and rescuing experiments demonstrated that PLD1 acts upstream of PKD1 in positively regulating dendritic spine morphogenesis. Using PLD1 inhibitor, we found that PLD1 activates PKD1 to promote dendritic spine morphogenesis. Thus, we further reveal the roles of the two different enzymes in neuronal development.