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Background Gene mutations have been implicated in DCM. However, due to the difficulty of clinical genetic diagnosis, more causal genes potentially related to DCM remain to be discovered. Methods We screened for gene mutations in more than 400 cases from families with hereditary cardiovascular disease using whole-exome sequencing. Then we validated biological functions of CHMP4C mutations in zebrafish models. To further assess the mechanism of CHMP4C mutations, we evaluated the potential signaling pathway in the cells. Results We identification of CHMP4C variants that segregated with DCM variants in four families from a total of 411 families via whole-exome sequencing. We further validate the function of CHMP4C in heart function in zebrafish models and found that over-expression of CHMP4C variants in zebrafish resulted in cardiac malformation, pericardial edema and increased heart rate, consistent with CHMP4C mutation-associated findings in DCM patients. Furthermore, we found that mutations in CHMP4C impaired autophagy and activated apoptosis in HEK293T cells, suggesting that the molecular mechanism of CHMP4C is involved in heart development. Conclusions CHMP4C is a novel candidate gene for DCM and may play a critical role in cardiac development by regulating autophagy. Funding Acknowledgement Type of funding source: None

Whether direct manipulation of Parkinson’s disease (PD) risk genes in monkey brain can elicit Parkinsonian phenotypes remains an unsolved issue. Here, we employed an adeno-associated virus (AAV)-delivered CRISPR/Cas9 system to directly co-edit PINK1 and DJ-1 genes in the substantia nigra (SN) region of four adult monkey brains. After the operation, two of the monkeys exhibited all classic PD symptoms, including bradykinesia, tremor, and postural instability, accompanied by severe nigral dopaminergic neuron loss (over 60%) and α-synuclein pathology. The aged monkeys were more vulnerable to gene editing by showing faster PD progression, higher final total PD scores, and severer pathologic changes compared with their younger counterparts, suggesting both the genetic and aging factors played important roles in PD development. This gene editing system can be used to develop a large quantity of genetically edited PD monkeys over a short period, thus providing a practical transgenic monkey model for future PD studies.

Astrocytes respond to and regulate neuronal activity, yet their role in mammalian behavior remains incompletely understood. Especially unclear is whether, and if so how, astrocyte activity regulates contextual fear memory, the dysregulation of which leads to pathological fear-related disorders. We generated GFAP-ChR2-EYFP rats to allow the specific activation of astrocytes in vivo by optogenetics. We found that after memory acquisition within a temporal window, astrocyte activation disrupted memory consolidation and persistently decreased contextual but not cued fear memory accompanied by reduced fear-related anxiety behavior. In vivo microdialysis experiments showed astrocyte photoactivation increased extracellular ATP and adenosine concentrations. Intracerebral blockade of adenosine A1 receptors (A1Rs) reversed the attenuation of fear memory. Furthermore, intracerebral or intraperitoneal injection of A1R agonist mimicked the effects of astrocyte activation. Therefore, our findings provide a deeper understanding of the astrocyte-mediated regulation of fear memory and suggest a new and important therapeutic strategy against pathological fear-related disorders., eLife digest Memory is the record of what we learn over time and is essential to our survival. But not all memories are helpful. Repeatedly recalling a traumatic event – such as an assault – can be harmful. About 1 in 3 people who experience severe trauma go on to develop post-traumatic stress disorder (PTSD), in which they re-live the traumatic event in the form of flashbacks and nightmares. Others develop panic disorder, phobias or depression. Preventing this chain of events is challenging because fear memories form rapidly and last a long time. Current treatments involve re-exposing individuals to the traumatic event. This could be real-life exposure in the case of a phobia. Or it could involve visualizing the event, in the case of PTSD. Controlled re-exposure can help individuals learn new coping strategies. But it does not erase the initial fear memory. A better approach might be to take advantage of the fact that new memories are unstable. To form a long-lasting memory trace, newly acquired information must go through a process called consolidation to stabilize it. This process takes place in an area of the brain called the hippocampus. If consolidation does not occur, new memory traces can fade away. Li, Li et al. now show that preventing consolidation in the rat brain stops the animals from forming lasting memories of a stressful event, namely a foot shock. In the study, the rats first learned to associate a foot shock with a tone. This training took place inside a specific chamber. After learning the association, the rats began to freeze – a sign of fear – whenever they entered the chamber. This happened even if the tone was not played. But Li, Li et al. showed that they could reduce this fear response by activating cells in the hippocampus known as astrocytes, shortly after the learning episode. Activating the astrocytes made them release a substance called adenosine. Molecules of adenosine then bound to and activated proteins called adenosine A1 receptors. Administering a drug that activated these receptors directly had the same effect as activating the astrocytes themselves. This suggests that drugs of this type could one day help patients with fear-related disorders such as PTSD and phobias. For this to become a reality, new studies must test different drugs and find the best ways of administering them. After testing in animal models, the next step will be preliminary clinical trials in people.

Although CRISPR/Cas9-mediated gene editing is widely applied to mimic human disorders, whether acute manipulation of disease-causing genes in the brain leads to behavioral abnormalities in non-human primates remains to be determined. Here we induced genetic mutations in MECP2, a critical gene linked to Rett syndrome (RTT) and autism spectrum disorders (ASDs), in the hippocampus (DG and CA1–4) of adolescent rhesus monkeys (Macaca mulatta) in vivo via adeno-associated virus (AAV)-delivered Staphylococcus aureus Cas9 with sgRNAs targeting MECP2. In comparison to monkeys injected with AAV-SaCas9 alone (n = 4), numerous autistic-like behavioral abnormalities were identified in the AAV-SaCas9-sgMECP2-injected monkeys (n = 7), including social interaction deficits, abnormal sleep patterns, insensitivity to aversive stimuli, abnormal hand motions and defective social reward behaviors. Furthermore, some aspects of ASDs and RTT, such as stereotypic behaviors, did not appear in the MECP2 gene-edited monkeys, suggesting that different brain areas likely contribute to distinct ASD symptoms. This study showed that acute manipulation of disease-causing genes via in vivo gene editing directly led to behavioral changes in adolescent primates, paving the way for the rapid generation of genetically engineered non-human primate models for neurobiological studies and therapeutic development.

Retinitis pigmentosa (RP) is a form of inherited retinal degenerative disease that ultimately involves the macula, which is present in primates but not in the rodents. Therefore, creating nonhuman primate (NHP) models of RP is of critical importance to study its mechanism of pathogenesis and to evaluate potential therapeutic options in the future. Here we applied adeno-associated virus (AAV)-delivered CRISPR/SaCas9 technology to knockout the RHO gene in the retinae of the adult rhesus macaque (Macaca mulatta) to investigate the hypothesis whether non-germline mutation of the RHO gene is sufficient to recapitulate RP. Through a series of studies, we were able to demonstrate successful somatic editing of the RHO gene and reduced RHO protein expression. More importantly, the mutant macaque retinae displayed clinical RP phenotypes, including photoreceptor degeneration, retinal thinning, abnormal rod subcellular structures, and reduced photoresponse. Therefore, we suggest somatic editing of the RHO gene is able to phenocopy RP, and the reduced time span in generating NHP mutant accelerates RP research and expands the utility of NHP model for human disease study.

Amygdala is the central brain region governing emotional responses of mammals. However, the detailed molecular taxonomy of amygdala in higher mammals such as primates is still absent. Here we present the molecular taxonomy of amygdala in rhesus monkeys by single-cell RNA sequencing analysis. We found that there are five major cell types in primate amygdala, glutamatergic neurons, GABAergic neurons, astroglia, oligodendrocytes and oligodendrocyte progenitor cells (OPCs). Glutamatergic neurons in the primate amygdala exhibits a great diversity comparing to them in the rodent amygdala. In particular, GABAergic neurons in primate amygdala appeared to be quite unique and contain different cellular composition as them in rodent amygdala. The astroglia in primate amygdala contains two more subtypes comparing to astroglia in rodent amygdala. Taken together, although the evolutionary conservation, the molecular taxonomy study of primate amygdala provides critical insights for understanding the cellular architecture of the primate brain.

MECP2gain-of-function and loss-of-function in genetically engineered monkeys recapitulates typical phenotypes in patients with autism, yet whereMECP2mutation affects the monkey brain and whether/how it relates to autism pathology remain unknown. Here we report a combination of gene–circuit–behavior analyses includingMECP2coexpression network, locomotive and cognitive behaviors, and EEG and fMRI findings in 5MECP2overexpressed monkeys (Macaca fascicularis; 3 females) and 20 wild-type monkeys (Macaca fascicularis; 11 females). Whole-genome expression analysis revealedMECP2coexpressed genes significantly enriched in GABA-related signaling pathways, whereby reduced β-synchronization within fronto-parieto-occipital networks was associated with abnormal locomotive behaviors. Meanwhile,MECP2-induced hyperconnectivity in prefrontal and cingulate networks accounted for regressive deficits in reversal learning tasks. Furthermore, we stratified a cohort of 49 patients with autism and 72 healthy controls of 1112 subjects using functional connectivity patterns, and identified dysconnectivity profiles similar to those in monkeys. By establishing a circuit-based construct link between genetically defined models and stratified patients, these results pave new avenues to deconstruct clinical heterogeneity and advance accurate diagnosis in psychiatric disorders.SIGNIFICANCE STATEMENTAutism spectrum disorder (ASD) is a complex disorder with co-occurring symptoms caused by multiple genetic variations and brain circuit abnormalities. To dissect the gene–circuit–behavior causal chain underlying ASD, animal models are established by manipulating causative genes such asMECP2. However, it is unknown whether such models have captured any circuit-level pathology in ASD patients, as demonstrated by human brain imaging studies. Here, we use transgenic macaques to examine the causal effect ofMECP2overexpression on gene coexpression, brain circuits, and behaviors. For the first time, we demonstrate that the circuit abnormalities linked toMECP2and autism-like traits in the monkeys can be mapped to a homogeneous ASD subgroup, thereby offering a new strategy to deconstruct clinical heterogeneity in ASD.

Base editing tools with diversified editing scopes and minimized RNA off-target activities are required for broad applications. Nevertheless, current Streptococcus pyogenes Cas9 (SpCas9)-based adenine base editors (ABEs) with minimized RNA off-target activities display constrained editing scopes with efficient editing activities at positions 4-8. Here, functional ABE variants with diversified editing scopes and reduced RNA off-target activities are identified using domain insertion profiling inside SpCas9 and with different combinations of TadA variants. Engineered ABE variants in this study display narrowed, expanded or shifted editing scopes with efficient editing activities across protospacer positions 2-16. And when combined with deaminase engineering, the RNA off-target activities of engineered ABE variants are further minimized. Thus, domain insertion profiling provides a framework to improve and expand ABE toolkits, and its combination with other strategies for ABE engineering deserves comprehensive explorations in the future., Current SpCas9 adenine base editors that minimise RNA off-target activities have constrained editing windows. Here the authors use domain insertion of TadA into Cas9 to narrow, expand or shift the editing window with RNA off-target minimization simultaneously

Site-specific DNA double-strand breaks have been used to generate knock-in through the homology-dependent or -independent pathway. However, low efficiency and accompanying negative impacts such as undesirable indels or tumorigenic potential remain problematic. In this study, we present an enhanced reduced-risk genome editing strategy we named as NEO, which used either site-specific trans or cis double-nicking facilitated by four bacterial recombination factors (RecOFAR). In comparison to currently available approaches, NEO achieved higher knock-in (KI) germline transmission frequency (improving from zero to up to 10% efficiency with an average of 5-fold improvement for 8 loci) and ‘cleaner’ knock-in of long DNA fragments (up to 5.5 kb) into a variety of genome regions in zebrafish, mice and rats. Furthermore, NEO yielded up to 50% knock-in in monkey embryos and 20% relative integration efficiency in non-dividing primary human peripheral blood lymphocytes (hPBLCs). Remarkably, both on-target and off-target indels were effectively suppressed by NEO. NEO may also be used to introduce low-risk unrestricted point mutations effectively and precisely. Therefore, by balancing efficiency with safety and quality, the NEO method reported here shows substantial potential and improves the in vivo gene-editing strategies that have recently been developed.

Schizophrenia is a complex, severe psychiatric disorder with a high heritability that affects approximately 1% of the world's population. Numerous schizophrenia-related risk genes have been reported in large-scale studies, but the role of most genetic abnormalities in the pathogenesis of the disease is still obscure. In this study, using whole-exome sequencing, we identified a novel nonsense mutation c.1324C T in the Interleukin 1 receptor accessory protein (IL1RAP) gene in four affected individuals with schizophrenia of a Chinese family. IL1RAP was found involved in initiating the immune responses and regulating synaptic formation. Considering that schizophrenia has been hypothesized to be neurodevelopment disorder for decades, we further explored the influence of altered expression of IL1RAP gene on neuronal growth, and assessed whether this mutation affects the function of IL1RAP protein in IL-1 signaling pathway. We used lentivirus-mediated shRNA to knockdown the IL1RAP gene expression, which suppressed the axon and dendrites growth of cultured mouse cortical neurons. These defects can be recovered by human IL1RAP wild type construct, but not the R442* mutant construct. Furthermore, this mutant even inhibited neuronal growth and IL-1β-induced JNK phosphorylation when overexpressed in cortical neurons. Although overexpression of this mutant in HePG2 cells did not change IL1RAP protein expression, it partially prohibited the IL-1β-induced nuclear translocation of transcript factor NF-κB, indicating that IL1RAP c.1324C T is a loss-of-function mutation. Our findings show that IL1RAP plays an important role in early stages of neurodevelopment, and the mutation c.1324C T may contribute to the pathogenesis of schizophrenia.

Duplication of MECP2 (Methyl-CpG-binding protein 2) causes severe mental illness called MECP2 duplication syndrome (MDS), yet the underlying mechanism remains elusive. Here we show, in Tg(MECP2) transgenic mouse brain or cultured neural progenitor cells (NPCs), that elevated MeCP2 expression promotes NPC differentiation into neurons. Ectopic expression of MeCP2 inhibits ADAM10 and thus the NOTCH pathway during NPC differentiation. In human cells, this downregulation on ADAM10 was mediated by miRNA-197, which is upregulated by MeCP2. Surprisingly, miR-197 binds to the ADAM10 3′-UTR via its 3′ side, not the canonical seed sequence on the 5′ side. In mouse cells, a noncoding RNA Gm28836 is used to replace the function of miR-197 between MeCP2 and ADAM10. Similar to MeCP2, overexpressing miR-197 also promotes NPCs differentiation into neurons. Interestingly, three rare missense mutations (H371R, E394K, and G428S) in MECP2, which we identified in a Han Chinese autism spectrum disorders (ASD) cohort showed loss-of-function effects in NPC differentiation assay. These mutations cannot upregulate miR-197. Overexpressing miR-197 together with these MeCP2 mutations could rescue the downregulation on ADAM10. Not only the inhibitor of miR-197 could reverse the effect of overexpressed MeCP2 on NPCs differentiation, but also overexpression of miR-197 could reverse the NPCs differentiation defects caused by MECP2 mutations. Our results revealed that a regulatory axis involving MeCP2, miR-197, ADAM10, and NOTCH signaling is critical for NPC differentiation, which is affected by both MeCP2 duplication and mutation.

MECP2 is a critical gene for neural development, mutations or duplication of which led to severe neurodevelopmental disorders, such as Rett syndrome (RTT) and autism spectrum disorders (ASD). Extensive works during the past decade yield ample insights into the molecular and cellular functions of MeCP2 in neural development. Furthermore, genetic manipulations in Mecp2 mouse models strongly suggested that deficiency in synaptic plasticity and various behaviors of Mecp2 null or transgenic mice could be rescued in adulthood. Further studies elucidating neural circuits responsible for symptoms in MECP2-associated disorders in rodent and non-human primate models will shed light on the development of potential therapeutic interventions.

In addition to the canonical role in protein homeostasis, autophagy has recently been found to be involved in axonal dystrophy and neurodegeneration. Whether autophagy may also be involved in neural development remains largely unclear. Here we report that Mir505–3p is a crucial regulator for axonal elongation and branching in vitro and in vivo, through modulating autophagy in neurons. We identify that the key target gene of Mir505–3p in neurons is Atg12, encoding ATG12 (autophagy-related 12) which is an essential component of the autophagy machinery during the initiation and expansion steps of autophagosome formation. Importantly, axonal development is compromised in brains of mir505 knockout mice, in which autophagy signaling and formation of autophagosomes are consistently enhanced. These results define Mir505–3p-ATG12 as a vital signaling cascade for axonal development via the autophagy pathway, further suggesting the critical role of autophagy in neural development.

Modeling brain disorders has always been one of the key tasks in neurobiological studies. A wide range of organisms including worms, fruit flies, zebrafish, and rodents have been used for modeling brain disorders. However, whether complicated neurological and psychiatric symptoms can be faithfully mimicked in animals is still debatable. In this review, we discuss key findings using non-human primates to address the neural mechanisms underlying stress and anxiety behaviors, as well as technical advances for establishing genetically-engineered non-human primate models of autism spectrum disorders and other disorders. Considering the close evolutionary connections and similarity of brain structures between non-human primates and humans, together with the rapid progress in genome-editing technology, non-human primates will be indispensable for pathophysiological studies and exploring potential therapeutic methods for treating brain disorders.

Autism spectrum disorder (ASD) encompasses a complex set of developmental neurological disorders, characterized by deficits in social communication and excessive repetitive behaviors. In recent years, ASD is increasingly being considered as a disease of the synapse. One main type of genetic aberration leading to ASD is gene duplication, and several mouse models have been generated mimicking these mutations. Here, we studied the effects of MECP2 duplication and human chromosome 15q11-13 duplication on synaptic development and neural circuit wiring in the mouse sensory cortices. We showed that mice carrying MECP2 duplication had specific defects in spine pruning, while the 15q11-13 duplication mouse model had impaired spine formation. Our results demonstrate that spine pathology varies significantly between autism models and that distinct aspects of neural circuit development may be targeted in different ASD mutations. Our results further underscore the importance of gene dosage in normal development and function of the brain.

Background: Gene mutations have been implicated in DCM. However, due to the difficulty of clinical genetic diagnosis, additional causal genes potentially related to DCM remain to be discovered. Methods: We screened for gene mutations in more than 400 cases from families with hereditary cardiovascular disease using whole-exome sequencing and then validated the biological functions of CHMP4C mutations in zebrafish models. To further assess the mechanism of CHMP4C mutations, we determined the potential signaling pathway in a cell line. Results: We identified via whole-exome sequencing CHMP4C variants that segregated with DCM in four families among a total of 411 families. We further validated the function of CHMP4C in heart function in zebrafish models and found that overexpression of CHMP4C variants resulted in cardiac malformation, pericardial edema and an increased heart rate, consistent with CHMP4C mutation-associated findings in DCM patients. Furthermore, mutations in CHMP4C impaired autophagy and activated apoptosis in HEK293T cells, suggesting that the molecular mechanism of CHMP4C is involved in heart development. Conclusions: CHMP4C is a novel candidate gene causing DCM and may play a critical role in cardiac development by regulating autophagy. Funding Statement: This work was supported by NSFC Grants (# 81671685, #31625013, and #91732302); Shanghai Science and Technology Committee Foundation (#17411954400); Shanghai Brain-Intelligence Project from STCSM (16JC1420501); Strategic Priority Research Program of the Chinese Academy of Sciences (XDBS01060200); Program of Shanghai Academic Research Leader, the Open Large Infrastructure Research of Chinese Academy of Sciences; and the Shanghai Municipal Science and Technology Major Project (#2018SHZDZX05). Declaration of Interests: None. Ethics Approval Statement: The study was approved by the Ethics Committee of Zhongshan Hospital, Fudan University (No. B2016-016(2)R).

Background CircRNAs are found to affect initiation and progression of several cancer types. However, whether circRNAs are implicated in gallbladder cancer (GBC) progression remains obscure. Methods We perform RNA sequencing in 10 pairs of GBC and para-cancer tissues. CCK8 and clone formation assays are used to evaluate proliferation ability of GBC cells. qPCR and Western blot are used to determine expression of RNAs and proteins, respectively. CircRNA-protein interaction is confirmed by RNA pulldown, RNA immunoprecipitation, and fluorescence in situ hybridization. Results We find that circRNA expression pattern is tremendously changed during GBC development. Among dozens of significantly changed circRNAs, a circRNA generated from the oncogene ERBB2, named as circERBB2, is one of the most significant changes. CircERBB2 promotes GBC proliferation, in vitro and in vivo. Other than being a miRNA sponge, circERBB2 accumulates in the nucleoli and regulates ribosomal DNA transcription, which is one of the rate-limiting steps of ribosome synthesis and cellular proliferation. CircERBB2 regulates nucleolar localization of PA2G4, thereby forming a circERBB2-PA2G4-TIFIA regulatory axis to modulate ribosomal DNA transcription and GBC proliferation. Increased expression of circERBB2 is associated with worse prognosis of GBC patients. Conclusions Our findings demonstrate that circERBB2 serves as an important regulator of cancer cell proliferation and shows the potential to be a new therapeutic target of GBC.

Organic solvent-based tissue clearing techniques are hampered by the quenching of fluorescent proteins, partially due to routine complete dehydration. Unexpectedly, we discovered that complete dehydration is unnecessary for organic solvents to clear tissues and that the hidden purpose has been to prevent emulsification. After controlling emulsification of organic solvent-cleared but incompletely dehydrated mouse brain, we achieved sufficient tissue transparency that allowed light-sheet imaging while well-preserving the fluorescence of fluorescent proteins.

Table S1. Key Resources Table. (DOCX 74 kb)

Objective: Anesthetics during early life stages may impair cognitive and emotional functions, of which the underlying molecular mechanisms remain largely unknown. Methods: Here we performed the unbiased transcriptome profiling in prefrontal cortex of both non-human primates and mice after anesthesia. We also constructed a brain blood barrier (BBB)-crossing AAV-PHP.EB vector to harbor GFP or ERMN expression cassette. Findings: We found that the thymidylate synthase gene (TYMS), a critical gene implicated in folate metabolism, was significantly downregulated after multiple anesthesia in both non-human primates and mice. Hereby, we examined the metabolites in plasma of patients with anesthesia and surprisingly found that blood folate levels significantly decreased after surgeries under general anesthesia in children. Combined with transcriptome and genome-wide DNA methylation analysis, we identified that ERMN was the primary target of the disrupted folate metabolism. We further showed that myelination in brain during early postnatal stage was indeed compromised by the anesthesia in mice, which was fully rescued by systematic administration of folic acid or expression of ERMN in the brain through brain-specific delivery of adeno-associated virus. Notably, administration of folic acid and ERMN remarkably alleviated the cognitive impairment of mice caused by the anesthesia during early postnatal stages. Interpretation: This study indicates that anesthesia during early the postnatal period leads to disrupted folate metabolism and subsequently defects in myelination in the young brain, and ERMN is the key target gene affected by anesthesia via epigenetic mechanisms. Clinical Trial Registration: NCT03746340 Funding Statement: This work was mainly supported by NSFC Grants (#81571028, # 81771132, #31625013, #91732302) Declaration of Interests: The authors declare no conflict of interest. Ethics Approval Statement: The study protocol was approved by the Human Research Ethics Committee of Shanghai 9th People’s Hospital and Shanghai Jiao Tong University in Shanghai, P. R. China SH9H-2018-T53-2. The animal studies were performed according to the guidelines and regulations of the Institute of Laboratory Animal Science, Peking Union Medical College and Chinese Academy of Medical Science (Peking, China). Efforts were made to minimize the number of animals in the studies. The use of rhesus macaque in research at Institute of Laboratory Animal Science (Peking, China) was approved by Institutional Animal Care and Use Committee (Protocol number #XC17001).

Background: The shape of the mitral valve is remodeled as heart function changes, even before cardiac decompensation and obvious clinical symptoms appear. How does the early mitral valve morphology change in carriers of pathogenic gene mutation in hypertrophic cardiomyopathy(HCM)? Methods: Whole exome sequencing was performed on the probands of 258 families affected by HCM. Ninety-one families with definite pathogenic gene mutations. Sanger sequencing of families with definitive diseasecausing gene mutations was performed to verify the genotype, which was divided into the HCM group (G+/LVH+, n = 167); pathogenic gene mutationcarrying group (G+/LVH-, n = 149); and non-pathogenic gene mutationcarrying group (G-/LVH-, n = 189). Two-dimensional and three-dimensional ultrasound images were acquired from all family members, and mitral valve morphology parameters were analyzed and compared among the groups. Results: The results showed that the anteroposterior diameter and annulus height of G+/LVH+ were higher than those of G+/LVH- and G-/LVH-. The anterolateral-posteromedial diameter and sphericity index of G+/LVH+ and G+/LVH- differed significantly from those of G-/LVH-. The annulus circumference (3D), annulus area (2D), and annulus area (3D) of G+/LVH- were significantly lower than those of G+/LVH+ and G-/LVH-. The leaflets tenting volume, tenting height, commissural diameter, and annular height-to-commissural width ratio (AHCWR) (%) of G+/LVH- were significantly lower than those of G-/LVH- (1.4 ± 1.2 vs. 1.9 ± 0.9, p < 0.001) (7.7 ± 2.4 vs. 8.2 ± 2.0, p < 0.05), (2.8 ± 0.5 vs. 3.3 ± 0.3, p < 0.001), (23.1 ± 7.1 vs. 25.9 ± 6.5, p < 0.05). The angle between the mitral annulus plane and aortic valve annulus plane of G+/LVH+ was lower than that of G-/LVH- (134.4 ± 16.4 vs. 138.4 ± 13.4). Further studies revealed that mitral valve morphology parameters in the MYBPC3+/LVHgroup were significantly reduced compared with G-/LVH- group, whereas those parameters in the MYH7+/LVH- group showed no significant differences. Conclusions: Mitral valve morphological parameters show early deformation with a flatter appearance in pathogenic gene mutation carriers. They can be used as sensitive parameters to detect abnormal cardiac function in carriers of HCM, particularly in the carriers of MYBPC3 gene mutations. Funding Statement: This study was supported by grant no. 81671685 from the National Science Foundation of China and grant no. 17411954400 from the Science and Technology Committee Foundation of Shanghai. Declaration of Interests: The authors stated: "None." Ethics Approval Statement: The study was approved by the Ethics Committee of Zhongshan Hospital, affiliated to Fudan University (no. 2016-16B), and all subjects gave informed consent.

Background Analysis of cell-free DNA (cfDNA) is promising for broad applications in clinical settings, but with significant bias towards late-stage cancers. Although recent studies have discussed the diverse and degraded nature of cfDNA molecules, little is known about its impact on the practice of cfDNA analysis. Methods We developed single-strand library preparation and hybrid-capture-based cfDNA sequencing (SLHC-seq) to analysis degraded cfDNA fragments. Next we used SLHC-seq to perform cfDNA profiling in 112 pancreatic cancer patients, and the results were compared with 13 previous reports. Extensive analysis was performed in terms of cfDNA fragments to explore the reasons for higher detection rate of KRAS mutations in the circulation of pancreatic cancers. Findings By applying the new approach, we achieved higher efficiency in analysis of mutations than previously reported using other detection assays. 791 cancer-specific mutations were detected in plasma of 88% patients with KRAS hotspots detected in 70% of all patients. Only 8 mutations were detected in 28 healthy controls without any known oncogenic or truncating alleles. cfDNA profiling by SLHC-seq was largely consistent with results of tissue-based sequencing. SLHC-seq rescued short or damaged cfDNA fragments along to increase the sensitivity and accuracy of circulating-tumour DNA detection. Interpretation We found that the small mutant fragments are prevalent in early-stage patients, which provides strong evidence for fragment size-based detection of pancreatic cancer. The new pipeline enhanced our understanding of cfDNA biology and provide new insights for liquid biopsy.

An HDR-based Cas9/RecA system was developed to precisely correct the Pde6b mutation in rods of rd1 mice to restore their vision., Although Cas9-mediated genome editing has been widely used to engineer alleles in animal models of human inherited diseases, very few homology-directed repair (HDR)–based genetic editing systems have been established in postnatal mouse models for effective and lasting phenotypic rescue. Here, we developed an HDR-based Cas9/RecA system to precisely correct Pde6b mutation with increased HDR efficiency in postnatal rodless (rd1) mice, a retinitis pigmentosa (RP) mutant model characterized by photoreceptor degeneration and loss of vision. The Cas9/RecA system incorporated Cas9 endonuclease enzyme to generate double-strand breaks (DSBs) and bacterial recombinase A (RecA) to increase homologous recombination. Our data revealed that Cas9/RecA treatment significantly promoted the survival of both rod and cone photoreceptors, restored the expression of PDE6B in rod photoreceptors, and enhanced the visual functions of rd1 mice. Thus, this study provides a precise therapeutic strategy for RP and other genetic diseases.

How MECP2 (Methyl-CpG-binding protein 2) duplication affects cortex development remains elusive. We found that elevated MeCP2 expression promotes neurogenesis during cortex development in Tg(MECP2) mouse brain. Ectopic expression of MeCP2 in NPCs inhibits ADAM10 and hence compromises the NOTCH pathway during NPC differentiation. MeCP2 up-regulates miR-197 to down-regulate ADAM10. The enhanced NPC differentiation/migration in Tg(MECP2) embryonic brain can be repressed by overexpression of ADAM10 or a miR-197 inhibitor.Consistently, the reduced neurogenesis induced by three rare MeCP2 missense mutations (H371R, E394K, G428S) identified in a Han Chinese autism spectrum disorders (ASD) cohort, can be reversed by miR-197 both in vitro and in vivo. Our results revealed that a regulatory axis involving MeCP2, miR-197, ADAM10, and NOTCH signaling is critical for neurogenesis, which is affected by both MeCP2 duplication and mutation.

孤独症是一种严重的神经发育性疾病, 主要症状有重复刻板行为、社交沟通障碍及语言发育迟缓等, 多发于2~5岁幼儿中, 症状往往伴随患者终生. 经过长期的遗传学研究, 基因的变异包括点突变与大片段缺失及重复在孤独症的发病因素中占到了很大的比例. 但是目前并未发现有某些少数主效基因占到孤独症遗传变异的主要地位, 提示孤独症是一种多基因致病, 并与环境因素密切相关的复杂疾病. 对孤独症的神经生物学研究揭示, 在孤独症中发生突变的基因多编码影响神经系统发育及突触传导的重要蛋白, 因此神经发育及突触传导的异常很可能是导致孤独症的重要因素. 目前在多种模式生物, 包括大小鼠及非人灵长类中构建了基于基因操作的孤独症模型. 随着基础研究的不断深入, 最终将揭示孤独症致病因素并找到有效干预方法.

SummaryDendritic spines are postsynaptic compartments of excitatory synapses that undergo dynamic changes during development, including rapid spinogenesis in early postnatal life and significant pruning during adolescence. Spine pruning defects have been implicated in developmental neurological disorders such as autism, yet much remains to be uncovered regarding its molecular mechanism. Here, we show that spine pruning and maturation in the mouse somatosensory cortex are coordinated via the cadherin/catenin cell adhesion complex and bidrectionally regulated by sensory experience. We further demonstrate that locally enhancing cadherin/catenin-dependent adhesion or photo-stimulating a contacting channelrhodopsin-expressing axon stabilized the manipulated spine and eliminated its neighbors, an effect requiring cadherin/catenin-dependent adhesion. Importantly, we show that differential cadherin/catenin-dependent adhesion between neighboring spines biased spine fate in vivo. These results suggest that activity-induced inter-spine competition for β-catenin provides specificity for concurrent spine maturation and elimination and thus is critical for the molecular control of spine pruning during neural circuit refinement.

Accumulated genetic evidences indicate that the contactin associated protein-like (CNTNAP) family is implicated in autism spectrum disorders (ASD). In this study, we identified genetic mutations in the CNTNAP3 gene from Chinese Han ASD cohorts and Simons Simplex Collections. We found that CNTNAP3 interacted with synaptic adhesion proteins Neuroligin1 and Neuroligin2, as well as scaffolding proteins PSD95 and Gephyrin. Significantly, we found that CNTNAP3 played an opposite role in controlling the development of excitatory and inhibitory synapses in vitro and in vivo, in which ASD mutants exhibited loss-of-function effects. In this study, we showed that Cntnap3-null mice exhibited deficits in social interaction, spatial learning and prominent repetitive behaviors. These evidences elucidate the pivotal role of CNTNAP3 in synapse development and social behaviors, providing the mechanistic insights for ASD.

Working memory (WM) is crucial for animals to execute cognitive tasks that require short-term storage and manipulation of sensory information in the order of seconds to minutes. WM is strongly correlated with human intelligence and deficits in this process lead to many psychiatric disorders, including Alzheimer's disease (AD), schizophrenia and autism. The proper functioning of WM involves multiple brain areas, including the sensory cortex and prefrontal cortex. Persistent or recurrent neural activity within these brain areas, together with neural oscillations among these brain areas, is known to encode the WM. However, the coding mechanisms of WM at the microcircuitry level still remain elusive. In this study, we performed two-photon imaging on behaving mice to monitor the activity of neuronal microcircuitry. We also revealed a neuronal subpopulation in the medial prefrontal cortex (mPFC) that exhibited emergent properties in a context-dependent manner underlying a WM-like behavior paradigm. These neuronal subpopulations are exclusively composed of excitatory neurons and mainly represent a group of neurons with more functional connections within the mPFC microcircuitry. This type of microcircuitry plasticity was maintained in minutes and was absent in an animal model of AD. Thus, these results identify a novel functional coding mechanism that relies on the emergent behavior of a functional-defined neuronal assembly to encode WM.

The cholinergic system in the brain plays crucial roles in regulating sensory and motor functions as well as cognitive behaviors by modulating neuronal activity. Understanding the organization of the cholinergic system requires a complete map of cholinergic neurons and their axon arborizations throughout the entire brain at the level of single neurons. Here, we report a comprehensive whole-brain atlas of the cholinergic system originating from various cortical and subcortical regions of the mouse brain. Using genetically labeled cholinergic neurons together with whole-brain reconstruction of optical images at 2-μm resolution, we obtained quantification of the number and soma volume of cholinergic neurons in 22 brain areas. Furthermore, by reconstructing the complete axonal arbors of fluorescently labeled single neurons from a subregion of the basal forebrain at 1-μm resolution, we found that their projections to the forebrain and midbrain showed neuronal subgroups with distinct projection specificity and diverse arbor distribution within the same projection area. These results suggest the existence of distinct subtypes of cholinergic neurons that serve different regulatory functions in the brain and illustrate the usefulness of complete reconstruction of neuronal distribution and axon projections at the mesoscopic level.

Most patients with hypertrophic cardiomyopathy have single-gene autosomal dominant mutations in loci that encode for sarcomeric proteins. The aim of this study was to determine whether pathogenic mutations were present by whole-exome sequencing (WES) in two families with hypertrophic cardiomyopathy (HCM) that presented during adolescence. Blood samples and clinical data were collected from individuals in two families with HCM. DNA was extracted. Mutations were identified using whole-exome sequencing (WES), and the genotypes of family members were identified using Sanger sequencing. Compound heterozygous mutations in the MYBPC3 gene (c.659A > G, p.Tyr220Cys; c.772G > A, p.Glu258Lys,NM_000256, Family 1), (c.873delG, p. Ile292PhefsTer8; c.3G > A, p.Met1?, NM_000256, Family 2) were identified by WES. Patient 1 carried the maternally inherited c.659A > G mutation and the paternally inherited c.772G > A mutation. Patient 2 carried the maternally inherited frameshift mutation c.873delG and the paternally inherited mutation c.3G > A. Two families with HCM presenting during adolescence (age of onset is about 11 years old) demonstrated compound heterozygous mutations in the MYBPC3 gene. These findings suggested an association of MYBPC3 mutations with the early onset of symptoms and worsened prognoses. Our study highlights the importance of genetic screening of all family members in cases of HCM.

The autism spectrum disorders (ASDs) are a collection of human neurological disorders with heterogeneous etiologies. Hyperactivity of E3 ubiquitin (Ub) ligase UBE3A, stemming from 15q11-q13 copy number variations, accounts for 1%-3% of ASD cases worldwide, but the underlying mechanisms remain incompletely characterized. Here we report that the functionality of ALDH1A2, the rate-limiting enzyme of retinoic acid (RA) synthesis, is negatively regulated by UBE3A in a ubiquitylation-dependent manner. Excessive UBE3A dosage was found to impair RA-mediated neuronal homeostatic synaptic plasticity. ASD-like symptoms were recapitulated in mice by overexpressing UBE3A in the prefrontal cortex or by administration of an ALDH1A antagonist, whereas RA supplements significantly alleviated excessive UBE3A dosage-induced ASD-like phenotypes. By identifying reduced RA signaling as an underlying mechanism in ASD phenotypes linked to UBE3A hyperactivities, our findings introduce a new vista of ASD etiology and facilitate a mode of therapeutic development against this increasingly prevalent disease.

Summary: Short-term memory (STM) is crucial for animals to hold information for a small period of time. Persistent or recurrent neural activity, together with neural oscillations, is known to encode the STM at the cellular level. However, the coding mechanisms at the microcircuitry level remain a mystery. Here, we performed two-photon imaging on behaving mice to monitor the activity of neuronal microcircuitry. We discovered a neuronal subpopulation in the medial prefrontal cortex (mPFC) that exhibited emergent properties in a context-dependent manner underlying a STM-like behavior paradigm. These neuronal subpopulations exclusively comprise excitatory neurons and mainly represent a group of neurons with stronger functional connections. Microcircuitry plasticity was maintained for minutes and was absent in an animal model of Alzheimer’s disease (AD). Thus, these results point to a functional coding mechanism that relies on the emergent behavior of a functionally defined neuronal assembly to encode STM.

Nat. Neurosci. 19, 1123–1130 (2016); published online 26 August 2016; corrected after print 29 August 2016 In the version of this article initially published online, the first author's name appears as “Charles Jennings” without middle initial; it has been changed to “Charles G Jennings”. Another author's name appears in the author list as “Angela Roberts,” also without middle initial; it has been changed to “Angela C Roberts.

© 2017 American Society for Microbiology. L-2-Hydroxyglutarate aciduria (L-2-HGA) is an autosomal recessive neurometabolic disorder caused by a mutation in the L-2-hydroxyglutarate dehydrogenase (L2HGDH) gene. In this study, we generated L2hgdh knockout (KO) mice and observed a robust increase of L-2-hydroxyglutarate (L-2-HG) levels in multiple tissues. The highest levels of L-2-HG were observed in the brain and testis, with a corresponding increase in histone methylation in these tissues. L2hgdh KO mice exhibit white matter abnormalities, extensive gliosis, microglia-mediated neuroinflammation, and an expansion of oligodendrocyte progenitor cells (OPCs). Moreover, L2hgdh deficiency leads to impaired adult hippocampal neurogenesis and late-onset neurodegeneration in mouse brains. Our data provide in vivo evidence that L2hgdh mutation leads to L-2-HG accumulation, leukoencephalopathy, and neurodegeneration in mice, thereby offering new insights into the pathophysiology of L-2-HGA in humans.

Methyl-CpG-binding protein 2 (MeCP2) is a classic methylated-DNA-binding protein, dysfunctions of which lead to various neurodevelopmental disorders such as Rett syndrome and autism spectrum disorder. Initially recognized as a transcriptional repressor, MeCP2 has been studied extensively and its functions have been expanded dramatically in the past two decades. Recently, it was found to be involved in gene regulation at the post-transcriptional level. MeCP2 represses nuclear microRNA processing by interacting directly with the Drosha/DGCR8 complex. In addition to its multifaceted functions, MeCP2 is remarkably modulated by posttranslational modifications such as phosphorylation, SUMOylation, and acetylation, providing more regulatory dimensions to its functions. The role of MeCP2 in the central nervous system has been studied extensively, from neurons to glia. Future investigations combining molecular, cellular, and physiological methods are necessary for defining the roles of MeCP2 in the brain and developing efficient treatments for MeCP2-related brain disorders.

Mutations of X-linked gene Methyl CpG binding protein 2 (MECP2) are the major causes of Rett syndrome (RTT), a severe neurodevelopmental disorder. Duplications of MECP2-containing genomic segments lead to severe autistic symptoms in human. MECP2-coding protein methyl-CpG-binding protein 2 (MeCP2) is involved in transcription regulation, microRNA processing and mRNA splicing. However, molecular mechanisms underlying the involvement of MeCP2 in mRNA splicing in neurons remain largely elusive. In this work we found that the majority of MeCP2-associated proteins are involved in mRNA splicing using mass spectrometry analysis with multiple samples from Mecp2-null rat brain, mouse primary neuron and human cell lines. We further showed that Mecp2 knockdown in cultured cortical neurons led to widespread alternations of mRNA alternative splicing. Analysis of ChIP-seq datasets indicated that MeCP2-regulated exons display specific epigenetic signatures, with DNA modification 5-hydroxymethylcytosine (5hmC) and histone modification H3K4me3 are enriched in down-regulated exons, while the H3K36me3 signature is enriched in exons up-regulated in Mecp2-knockdown neurons comparing to un-affected neurons. Functional analysis reveals that genes containing MeCP2-regulated exons are mainly involved in synaptic functions and mRNA splicing. These results suggested that MeCP2 regulated mRNA splicing through interacting with 5hmC and epigenetic changes in histone markers, and provide functional insights of MeCP2-mediated mRNA splicing in the nervous system.

Features of all 120 participants with ASD. (DOCX 29Â kb)

Primers applied for Sanger sequencing and mutagenesis. (DOCX 14Â kb)

Summary of developmental and family status of ASD patients carrying MECP2 mutations. (DOCX 16Â kb)

Duplications of Methyl CpG binding protein 2 (MECP2) -containing segments lead to the MECP2 duplication syndrome, in which severe autistic symptoms were identified. Whether adult neurogenesis may play a role in pathogenesis of autism and the role of MECP2 on state determination of adult neural stem cells (NSCs) remain largely unclear. Using a MECP2 transgenic (TG) mouse model for the MECP2 duplication syndrome, we found that adult hippocampal quiescent NSCs were significantly accumulated in TG mice comparing to wild type (WT) mice, the neural progenitor cells (NPCs) were reduced and the neuroblasts were increased in adult hippocampi of MECP2 TG mice. Interestingly, we found that parvalbumin (PV) positive interneurons were significantly decreased in MECP2 TG mice, which were critical for determining fates of adult hippocampal NSCs between the quiescence and activation. In summary, we found that MeCP2 plays a critical role in regulating fate determination of adult NSCs. These evidences further suggest that abnormal development of NSCs may play a role in the pathogenesis of the MECP2 duplication syndrome.