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RNA-binding motif 8A (RBM8A) is a core component of the exon junction complex (EJC) that binds pre-mRNAs and regulates their splicing, transport, translation, and nonsense-mediated decay (NMD). Dysfunction in the core proteins has been linked to several detriments in brain development and neuropsychiatric diseases. To understand the functional role of Rbm8a in brain development, we have generated brain-specific Rbm8a knockout mice and used next-generation RNA-sequencing to identify differentially expressed genes (DEGs) in mice with heterozygous, conditional knockout (cKO) of Rbm8a in the brain at postnatal day 17 (P17) and at embryonic day 12. Additionally, we analyzed enriched gene clusters and signaling pathways within the DEGs. At the P17 time point, between the control and cKO mice, about 251 significant DEGs were identified. At E12, only 25 DEGs were identified in the hindbrain samples. Bioinformatics analyses have revealed many signaling pathways related to the central nervous system (CNS). When E12 and P17 results were compared, three DEGs, Spp1, Gpnmb, and Top2a, appeared to peak at different developmental time points in the Rbm8a cKO mice. Enrichment analyses suggested altered activity in pathways affecting cellular proliferation, differentiation, and survival. The results support the hypothesis that loss of Rbm8a causes decreased cellular proliferation, increased apoptosis, and early differentiation of neuronal subtypes, which may lead ultimately to an altered neuronal subtype composition in the brain.

Triadica sebifera (Linnaeus) Small is a tree species native to China. The seeds of T. sebifera are rich in oil and are widely used in industrial fields. To explore the genetic diversity and genetic differentiation of T. sebifera germplasm resources, 10 pairs of microsatellite markers were applied to 203 samples collected from eight populations. Forty-three alleles were detected. The average expected heterozygosity (He = 0.491) revealed a low level of genetic diversity. The genetic differentiation among T. sebifera populations was low (Fst = 0.026), which might be related to high gene flow (average Nm = 11.151). Genetic distance and structure results further confirmed that the genetic compositions of the eight populations were quite similar. One of the possible reasons for this phenomenon is that the early introduction and cultivation of T. sebifera were common, so gene exchange was frequent among populations. However, UPGMA clustering results indicated that the eight T. sebifera populations could still be divided into three categories. The classification was related to their geographical location: the southwestern group (ZY), central group (HG and XY) and eastern group (LS, HS, LX, XZ and LY). The reason for this differentiation might be severe deforestation following the decline in T. sebifera economic status. In addition, the central XY population had the largest number of rare alleles (4). In conclusion, although T. sebifera germplasm resources had a low level of genetic diversity, several rare alleles were detected in the central populations, which are valuable for breeding. These resources should be conserved to maintain genetic diversity in the T. sebifera populations. Moreover, geographical distances were important reasons for the limited genetic variations among the populations.

Calling cards technology using self-reporting transposons enables the identification of DNA-protein interactions through RNA sequencing. Although immensely powerful, current implementations of calling cards in bulk experiments on populations of cells are technically cumbersome and require many replicates to identify independent insertions into the same genomic locus. Here, we have drastically reduced the cost and labor requirements of calling card experiments in bulk populations of cells by introducing a DNA barcode into the calling card itself. An additional barcode incorporated during reverse transcription enables simultaneous transcriptome measurement in a facile and affordable protocol. We demonstrate that barcoded self-reporting transposons recover in vitro binding sites for four basic helix-loop-helix transcription factors with important roles in cell fate specification: ASCL1, MYOD1, NEUROD2, and NGN1. Further, simultaneous calling cards and transcriptional profiling during transcription factor overexpression identified both binding sites and gene expression changes for two of these factors. Lastly, we demonstrated barcoded calling cards can record binding in vivo in the mouse brain. In sum, RNA-based identification of transcription factor binding sites and gene expression through barcoded self-reporting transposon calling cards and transcriptomes is an efficient and powerful method to infer gene regulatory networks in a population of cells.

Styrax zhejiangensis is an endemic species to China and is only distributed in Jiande, Zhejiang Province. The species is on the verge of extinction. The chloroplast genome of S. zhejiangensis was determined from Illumina pair-end sequencing data. The sequence was 157,387 bp and consisted of one large (LSC, 87,193 bp) and one small (SSC, 18,286 bp) single-copy region region, separated by a pair of inverted repeat (IR, 25,954 bp) regions. The sequence included 116 genes, including 82 protein-coding genes, 19 rRNAs and 15 tRNAs. The overall GC content was 37.0%. A maximum likelihood phylogenetic analysis showed that Styracaceae was more closely related to Symplocaceae than to Ebenaceae.

Schizophrenia (SZ) is a devastating brain disease that affects about 1% of world population. Among the top genetic associations,zinc finger protein 804A(ZNF804A) gene encodes a zinc finger protein, associated with SZ and biolar disorder (BD). Copy number variants (CNVs) ofZNF804Ahave been observed in patients with autism spectrum disorders (ASDs), anxiety disorder, and BD, suggesting thatZNF804Ais a dosage sensitive gene for brain development. However, its molecular functions have not been fully determined. Our previous interactomic study revealed that ZNF804A interacts with multiple proteins to control protein translation and neural development. ZNF804A is localized in the cytoplasm and neurites in the human cortex and is expressed in various types of neurons, including pyramidal, dopaminergic, GABAergic, and Purkinje neurons in mouse brain. To further examine the effect of gene dosage ofZNF804Aon neurite morphology, both knockdown and overexpression ofZNF804Ain primary neuronal cells significantly attenuate dendritic complex and spine formation. To determine the factors mediating these phenotypes, interestingly, three binding proteins of ZNF804A, galectin 1 (LGALS1), fasciculation and elongation protein zeta 1 (FEZ1) and ribosomal protein SA (RPSA), show different effects on reversing the deficits. LGALS1 and FEZ1 stimulate neurite outgrowth at basal level but RPSA shows no effect. Intriguingly, LGALS1 but not FEZ1, reverses the neurite outgrowth deficits induced by ZNF804A knockdown. However, FEZ1 and RPSA but not LGALS1, can ameliorate ZNF804A overexpression-mediated dendritic abnormalities. Thus, our results uncover a critical post-mitotic role of ZNF804A in neurite and synaptic development relevant to neurodevelopmental pathologies.

Additional file 1.. Additional figure and tables.

The formation of the nervous system requires a balance between proliferation, differentiation, and migration of neural progenitors (NPs). Mutations in genes regulating development impede neurogenesis and lead to neuropsychiatric diseases, including autism spectrum disorders (ASDs) and schizophrenia (SZ). Recently, mutations in nonsense-mediated mRNA decay genes have been associated with ASDs, intellectual disability (ID), and SZ. Here, we examine the function of a gene in the exon junction complex, Rbm8a, in the cortical development. When Rbm8a is selectively knocked out in neural stem cells, the resulting mice exhibit microcephaly, early postnatal lethality, and altered distribution of excitatory neurons in the neocortex. Moreover, Rbm8a haploinsufficiency in the central nervous system decreases cell proliferation in the ganglionic eminences. Parvalbumin+ and neuropeptide Y+ interneurons in the cortex are significantly reduced, and distribution of interneurons are altered. Consistently, neurons in the cortex of conditional knockout (cKO) mice show a significant decrease in GABA frequency. Transcriptomic analysis revealed differentially expressed genes enriched in telencephalon development and mitosis. To further investigate the role of Rbm8a in interneuron differentiation, conditional KO of Rbm8a in NKX2.1 interneuron progenitor cells reduces progenitor proliferation and alters interneuron distributions. Taken together, these data reveal a critical role of Rbm8a in interneuron development, and establish that perturbation of this gene leads to profound cortical deficits.

The intracellular delivery of biofunctional enzymes or therapeutic proteins through systemic administration is of great importance in therapeutic intervention of various diseases. However, current strategies face substantial challenges owing to various biological barriers, including susceptibility to protein degradation and denaturation, poor cellular uptake, and low transduction efficiency into the cytosol. Here, we developed a biomimetic nanoparticle platform for systemic and intracellular delivery of proteins. Through a biocompatible strategy, guest proteins are caged in the matrix of metal-organic frameworks (MOFs) with high efficiency (up to ∼94%) and high loading content up to ∼50 times those achieved by surface conjunction, and the nanoparticles were further decorated with the extracellular vesicle (EV) membrane with an efficiency as high as ∼97%. In vitro and in vivo study manifests that the EV-like nanoparticles can not only protect proteins against protease digestion and evade the immune system clearance but also selectively target homotypic tumor sites and promote tumor cell uptake and autonomous release of the guest protein after internalization. Assisted by biomimetic nanoparticles, intracellular delivery of the bioactive therapeutic protein gelonin significantly inhibits the tumor growth in vivo and increased 14-fold the therapeutic efficacy. Together, our work not only proposes a new concept to construct a biomimetic nanoplatform but also provides a new solution for systemic and intracellular delivery of protein.

PURPOSE OF REVIEW: This review summarizes recent studies on the molecular mechanisms of RNA binding proteins (RBPs) that control neurological functions and pathogenesis in various neurodevelopmental and neurodegenerative diseases, including autism spectrum disorders, schizophrenia, Alzheimer’s disease, amyotrophic lateral sclerosis, frontotemporal dementia, and spinocerebellar ataxia. RECENT FINDINGS: RBPs are critical players in gene expression that regulate every step of posttranscriptional modifications. Recent genome-wide approaches revealed that many proteins associate with RNA, but do not contain any known RNA binding motifs. Additionally, many causal and risk genes of neurodevelopmental and neurodegenerative diseases are RBPs. Development of high-throughput sequencing methods has mapped out the fingerprints of RBPs on transcripts and provides unprecedented potential to discover new mechanisms of neurological diseases. Insights into how RBPs modulate neural development are important for designing effective therapies for numerous neurodevelopmental and neurodegenerative diseases. SUMMARY: RBPs have diverse mechanisms for modulating RNA processing and, thereby, controlling neurogenesis. Understanding the role of disease-associated RBPs in neurogenesis is vital for developing novel treatments for neurological diseases.

Bretschneideraceae is a specific single species family, and Bretschneidera sinensis is listed as ‘Endangered’ on the IUCN Red List of Threatened Species. As a relict plant of the Tertiary, B. sinensis is significant for the study of ancient geography and climate change. B. sinensis is endemic to China and is sporadically distributed in Thailand and Vietnam. In this study, the complete plastid genome sequence of B. sinensis was characterized from Illumina paired-end sequencing data. The whole plastome is 154,279 bp in length, consisting of a pair of inverted repeat (IR) regions of 26,432 bp, one large single copy (LSC) region of 83,688 bp and one small single copy (SSC) region of 17,727 bp. The genome contains 112 genes, including 78 protein-coding genes, 4 ribosomal RNA genes and 30 transfer RNA genes. Among these 112 genes, 14 contain one intron, while only two genes harbor two introns. The overall GC content of the whole plastome is 37.4%, and the corresponding values of the IR, LSC and SSC regions are 42.7, 35.3 and 31.5%, respectively.

// Dazhi Deng 1,2 , Chongdong Jian 2,3 , Ling Lei 2,4 , Yijing Zhou 2 , Colleen McSweeney 2 , Fengping Dong 2 , Yilun Shen 2 , Donghua Zou 5 , Yonggang Wang 6 , Yuan Wu 3 , Limin Zhang 7 and Yingwei Mao 2 1 Department of Emergency, The People’s Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi, China 2 Department of Biology, Pennsylvania State University, University Park, PA, USA 3 Department of Neurology, First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi, China 4 Health Examination Center, The People’s Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi, China 5 Department of Neurology, The First People’s Hospital of Nanning, Nanning, Guangxi, China 6 Department of Neurology, School of Medicine, Renji Hospital, Shanghai Jiaotong University, Shanghai, China 7 CAS Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Centre for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China Correspondence to: Limin Zhang, email: // Yingwei Mao, email: // Keywords : DISC1, interneuron, neural progenitors, metabolism, depression, Pathology Section Received : March 14, 2017 Accepted : September 03, 2017 Published : September 28, 2017 Abstract Mental illnesses like schizophrenia (SCZ) and major depression disorder (MDD) are devastating brain disorders. The SCZ risk gene, disrupted in schizophrenia 1 ( DISC1 ), has been associated with neuropsychiatric conditions. However, little is known regarding the long-lasting impacts on brain metabolism and behavioral outcomes from genetic insults on fetal NPCs during early life. We have established a new mouse model that specifically interrupts DISC1 functions in NPCs in vivo by a dominant-negative DISC1 (DN-DISC1) with a precise temporal andspatialregulation. Interestingly, prenatal interruption of mouse Disc1 function in NPCs leads to abnormal depression-like deficit in adult mice. Here we took a novel unbiased metabonomics approach to identify brain-specific metabolites that are significantly changed in DN-DISC1 mice. Surprisingly, the inhibitory neurotransmitter, GABA, is augmented. Consistently, parvalbumin (PV) interneurons are increased in the cingulate cortex, retrosplenial granular cortex, and motor cortex. Interestingly, somatostatin (SST) positive and neuropeptide Y (NPY) interneurons are decreased in some brain regions, suggesting that DN-DISC1 expression affects the localization of interneuron subtypes. To further explore the cellular mechanisms that cause this change, DN-DISC1 suppresses proliferation and promotes the cell cycle exit of progenitors in the medial ganglionic eminence (MGE), whereas it stimulates ectopic proliferation of neighboring cells through cell non-autonomous effect. Mechanistically, it modulates GSK3 activity and interrupts Dlx2 activity in the Wnt activation. In sum, our results provide evidence that specific genetic insults on NSCs at a short period of time could lead to prolonged changes of brain metabolism and development, eventually behavioral defects.

A variety of hydrogels have been synthesized for controlling the release of signaling molecules in applications such as drug delivery and regenerative medicine. However, it remains challenging to synthesize hydrogels with the ability to control the release of signaling molecules sequentially or periodically under physiological conditions as living cells do in response to the variation of metabolism. The purpose of this work was to study a novel biomimetic hydrogel system with the ability of recapitulating the procedure of cellular signal transduction and controlling the sequential release of signaling molecules under physiological conditions. In the presence of a small chemical, the signaling molecule is regulated to change from a DNA-bound state to a free state and the freed signaling molecule is able to regulate intracellular signal transduction and cell migration. Moreover, periodic exposure of the hydrogel system to the small chemical leads to sequential protein release. Since signaling molecules are important for every activity of the cell, this hydrogel system holds potential as a metabolism-responsive platform for controlled release of signaling molecules and cell regulation in various applications.

CRISPR/Cas9 has been widely used for genomic editing in many organisms. Many human diseases are caused by multiple mutations. The CRISPR/Cas9 system provides a potential tool to introduce multiple mutations in a genome. To mimic complicated genomic variants in human diseases, such as multiple gene deletions or mutations, two or more small guide RNAs (sgRNAs) need to be introduced all together. This can be achieved by separate Pol III promoters in a construct. However, limited enzyme sites and increased insertion size lower the efficiency to make a construct. Here, we report a strategy to quickly assembly multiple sgRNAs in one construct using a polycistronic-tRNA-gRNA (PTG) strategy. Taking advantage of the endogenous tRNA processing system in mammalian cells, we efficiently express multiple sgRNAs driven using only one Pol III promoter. Using an all-in-one construct carrying PTG, we disrupt the deacetylase domain in multiple histone deacetylases (HDACs) in human cells simultaneously. We demonstrate that multiple HDAC deletions significantly affect the activation of the Wnt-signaling pathway. Thus, this method enables to efficiently target multiple genes and provide a useful tool to establish mutated cells mimicking human diseases.

Neonatal seizures are different from adult seizures, and many antiepileptic drugs that are effective in adults often fail to treat neonates. Here, we report that gluconate inhibits neonatal seizure by inhibiting CLC-3 chloride channels. We detect a voltage-dependent outward rectifying Cl− current mediated by CLC-3 Cl− channels in early developing brains but not adult mouse brains. Blocking CLC-3 Cl− channels by gluconate inhibits seizure activity both in neonatal brain slices and in neonatal animals with in vivo EEG recordings. Consistently, neonatal neurons of CLC-3 knockout mice lack the outward rectifying Cl− current and show reduced epileptiform activity upon stimulation. Mechanistically, we demonstrate that activation of CLC-3 Cl− channels alters intracellular Cl− homeostasis and enhances GABA excitatory activity. Our studies suggest that gluconate can suppress neonatal seizure activities through inhibiting CLC-3 Cl− channels in developing brains. Electronic supplementary material The online version of this article (10.1186/s13041-019-0465-0) contains supplementary material, which is available to authorized users.

Figure S1. Gluconate showed no effect on cation channels in neuronal cultures. Figure S2. Gluconate inhibits the Cl− currents recorded with physiologic [Cl−] in the pipette solution. Figure S3. Gluconate inhibits CLC-3 channel-mediated Cl− currents in HEK293T cell. Figure S4. Broad inhibition of NaGluc on epileptiform activity induced by various epileptic stimuli in neonatal hippocampal slices. Figure S5. β-HB inhibits CLC-3 channels and epileptiform activity in neonatal slices. Figure S6. Illustration of the procedure of hypoxia-ischemia induced neonatal epilepsy model. Figure S7. Synergistic effect between gluconate and phenobarbital on hypoxia-ischemia induced neonatal seizure activity in vivo. (DOCX 6978 kb)

Styrax zhejiangensis is an endemic species to China and is only distributed in Jiande, Zhejiang Province. The species is on the verge of extinction. The chloroplast genome of S. zhejiangensis was d...

Cyclin-dependent kinase 5 (CDK5) regulates important neuronal functions via p35. p35 undergoes cleavage in response to neuronal activity and neurotoxic conditions to release its subunit p25. Although p25 has been implicated in various neurodegenerative diseases, the mechanisms by which p25 mediates neurodegenerative impairment have not been fully elucidated. We aimed to determine the role of p25-mediated neurodegeneration on neurogenesis in an inducible transgenic mouse line overexpressing p25 (p25 TG) in the forebrain. Adult neuronal progenitor cells (NPCs) were labeled with BrdU in vivo, which were significantly increased in numbers in the subventricular zone, the hippocampus, and the cortex of p25 TG mice. Consistently, more mitotic cells were observed in p25 TG mice than in controls, even in the cortex and the CA1, which are not neurogenic regions. BrdU-positive cells were negative for GFAP or γ-H2AX, suggesting that they are not astrocytes or dying cells. Neurospheres derived from the dentate gyrus and the cortex were significantly increased in p25 TG mice and can be differentiated into astrocytes and neurons. However, p25 TG decreased the long-term survival of proliferating NPCs and severely impaired adult neurogenesis. A Transwell co-culture system was used to assess the influence of p25-expressing primary neurons on adult NPCs. Co-culture with p25-expressing neurons downregulated Ki67 expression and upregulated cleaved caspase-3, indicating that the paracrine signaling in cell-cell communication is essential for NPC survival and proliferation. Moreover, increased CDK5 activity impairs Wnt activation. This study demonstrates that hyperactivation of p25 may temporarily enhance NPC proliferation, but impair their long-term survival., Brain & Behavior Research Foundation (NARSAD Young Investigator Award), American Heart Association (American Heart Scientist Development Award), National Institutes of Health (U.S.) (NIH R01AG046174), National Natural Science Foundation (China) (Grant No. 81560205), National University of Defense Technology (China) (Research Foundation (JC 14-02-01)), Neurodegeneration Consortium, Glenn Foundation for Medical Research

Mutations in β-catenin (CTNNB1) have been implicated in cancer and mental disorders. Recently, loss-of-function mutations of CTNNB1 were linked to intellectual disability (ID), and rare mutations were identified in patients with autism spectrum disorder (ASD). As a key regulator of the canonical Wnt pathway, CTNNB1 plays an essential role in neurodevelopment. However, the function of CTNNB1 in specific neuronal subtypes is unclear. To understand how CTNNB1 deficiency contributes to ASD, we generated CTNNB1 conditional knockout (cKO) mice in parvalbumin interneurons. The cKO mice had increased anxiety, but had no overall change in motor function. Interestingly, CTNNB1 cKO in PV-interneurons significantly impaired object recognition and social interactions and elevated repetitive behaviors, which mimic the core symptoms of patients with ASD. Surprisingly, deleting CTNNB1 in parvalbumin-interneurons enhanced spatial memory. To determine the effect of CTNNB1 KO in overall neuronal activity, we found that c-Fos was significantly reduced in the cortex, but not in the dentate gyrus and the amygdala. Our findings revealed a cell type-specific role of CTNNB1 gene in regulation of cognitive and autistic-like behaviors. Thus, this study has important implications for development of therapies for ASDs carrying the CTNNB1 mutation or other ASDs that are associated with mutations in the Wnt pathway. In addition, our study contributes to a broader understanding of the regulation of the inhibitory circuitry.

Aim: To identify human hair cell progenitors from adult inner ear sensory epithelium. Materials & methods: We collected discarded utricles from translabyrinthine surgery and isolated human utricular sensory epithelial cells (HUCs) to explore whether they can proliferate and obtain features of stem/progenitor cells in vitro using reverse transcription PCR and immunofluorescence. Results: When cultured in vitro, HUCs expressed genes and proteins that are usually present in prosensory cells and stem cells. Additionally, dissociated HUCs expanded on the substrates and presented properties of mesenchymal cells via epithelial-to-mesenchymal transition. Conclusion: The results reveal that sensory epithelial cells from the adult human inner ear can re-enter the cell cycle and adopt a stem/progenitor cell fate. The outcomes of this study may open avenues for human hair cell progenitor generation, which could potentially provide a novel stem cell-based replacement for hearing loss and other inner ear disorders.

Background Nonsense mediated mRNA decay (NMD) is an RNA surveillance mechanism that controls RNA stability and ensures the speedy degradation of erroneous and unnecessary transcripts. This mechanism depends on several core factors in the exon junction complex (EJC), eIF4A3, RBM8a, Magoh, and BTZ, as well as peripheral factors to distinguish premature stop codons (PTCs) from normal stop codons in transcripts. Recently, emerging evidence has indicated that NMD factors are associated with neurodevelopmental disorders such as autism spectrum disorder (ASD) and intellectual disability (ID). However, the mechanism in which these factors control embryonic brain development is not clear. Result We found that RBM8a is critical for proliferation and differentiation in cortical neural progenitor cells (NPCs). RBM8a is highly expressed in the subventricular zone (SVZ) of the early embryonic cortex, suggesting that RBM8a may play a role in regulating NPCs. RBM8a overexpression stimulates embryonic NPC proliferation and suppresses neuronal differentiation. Conversely, knockdown of RBM8a in the neocortex reduces NPC proliferation and promotes premature neuronal differentiation. Moreover, overexpression of RBM8a suppresses cell cycle exit and keeps cortical NPCs in a proliferative state. To uncover the underlying mechanisms of this phenotype, genome-wide RNAseq was used to identify potential downstream genes of RBM8a in the brain, which have been implicated in autism and neurodevelopmental disorders. Interestingly, autism and schizophrenia risk genes are highly represented in downstream transcripts of RBM8a. In addition, RBM8a regulates multiple alternative splicing genes and NMD targets that are implicated in ASD. Taken together, this data suggests a novel role of RBM8a in the regulation of neurodevelopment. Conclusions Our studies provide some insight into causes of mental illnesses and will facilitate the development of new therapeutic strategies for neurodevelopmental illnesses. Electronic supplementary material The online version of this article (doi:10.1186/s13064-015-0045-7) contains supplementary material, which is available to authorized users.

Mesenchymal stem cells (MSCs) are emerging as a promising therapeutic approach of cell-based therapy for a wide range of autoimmune disorders and degenerative diseases. In preclinical and clinical studies, MSCs have been shown to be highly efficient in treating graft-versus-host disease, systemic lupus erythematosus, multiple sclerosis, type 1 diabetes, myocardial infarction, liver cirrhosis, inflammatory bowel disease, and other disorders. The underlying therapeutic mechanisms of MSCs include their homing efficiency to the tissue injury sites, their differentiation potential, their capability to produce a large amount of trophic factors, and their immunomodulatory effect. Because tissue damage sites are complicated milieus with distinct types of inflammatory cells and factors, available data have demonstrated that the properties of MSCs could be fundamentally influenced by the inflammatory elements. Thus, an understanding of the interaction between MSCs and the inflammatory microenvironment will provide critical information in revealing the precise in vivo mechanisms of MSC-mediated therapeutic effects and designing more practical protocols for clinical use of these cells.