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Background: Targeting the interaction between SDF1 and CXCR4 may provide an opportunity to intervene in the hematopoietic stem cell mobilization process. Aim: The present study aimed to investigate the safety, efficacy, pharmacokinetic and pharmacodynamic profiles of YF-H-2015005, a CXCR4 antagonist, for the mobilization of hematopoietic stem cells (HSCs). Methods: A total of 15 patients with non-Hodgkin's lymphoma (NHL) eligible for autologous hematopoietic stem cell transplantation were enrolled. All patients achieved a partial or complete remission after the first- or second-line therapy. Granulocyte colony stimulating factor (G-CSF) was given in the morning for 8 consecutive days, and 0.24 mg/kg YF-H-2015005 was subcutaneously administered in the evening of the 4th day of G-CSF treatment for up to four days. Apheresis was performed 9-10 hours following each dose of YF-H-2015005. Results: YF-H-2015005 was rapidly absorbed and eliminated, with Tmax and t1/2 of 0.5 and 5.04 ± 1.00 hours, respectively. Moreover, the mean peripheral blood CD34+ cell counts were elevated by 2.0- to 2.9-fold from 2 to 24 hours, and reached the maximum level of 76.5 ± 53.9 cells/kg at 10 hours after YF-H-2015005 treatment. Fourteen (93%) out of 15 NHL patients achieved a minimum target of ≥2×106/kg CD34+ cells. Furthermore, there was no grades 3-4 treatment-related adverse event observed among these patients. Conclusion: YF-H-2015005 can serve as a safe, effective agent in combination with G-CSF for CD34+ hematopoietic progenitor cell mobilization in NHL patients.

A series of N-phenyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine derivatives with NF-κB inducing kinase (NIK) inhibitory activity were obtained through structure-based drug design and synthetic chemistry. A...

The bromodomain and extra-terminal domain (BET) family of proteins are readers which specifically recognize histone-acetylated lysine residues. Each BET bromodomain protein contains two highly homologous domains: the first bromodomain (BD1) and the second bromodomain (BD2). Pan-BET bromodomain inhibition is a potential therapy for various cancers and immune-inflammatory diseases, but only few reported inhibitors show selectivity within the BET family. Herein, we identified a series of benzo[cd]indol-2(1H)-ones and pyrrolo[4,3,2-de]quinolin-2(1H)-ones with good selectivity for BET BD1. Through structure-based optimization, highly active and selective compounds are ultimately obtained. The representative compounds are the first reported inhibitors with selectivity more than 100-fold for BRD4(1) over BRD4(2). Among them, we further show that 68 (LT052) mediates BRD4/NF-κB/NLRP3 signaling inflammatory pathways with comparable protein expression and significantly improves symptoms of gout arthritis in a rat model. Therefore, selective pharmacological modulation of individual bromodomains could represent a strategy for the treatment of acute gouty arthritis.

Background: The Pharmacokinetics of Methotrexate (MTX) has been reported to show significant intersubject variability. MTX is metabolized by SHMT1 and transported by OATP1B1 and OATP1B3 both of which show genetic polymorphisms. The non-genetic and genetic factors may influence the pharmacokinetics of MTX. Objective: This study aimed to determine the pharmacokinetic parameters of MTX in Chinese patients and to investigate the effect of various non-genetic factors and genetic variants of OATP1B1, OATP1B3 on MTX’s pharmacokinetics. Method: MTX concentration and clinical characteristics data were collected from 71 rheumatoid arthritis patients. For each patient, SLC19A1, SHMT1, OATP1B1, and OATP1B3 genotyping were tested. Population pharmacokinetic analysis was performed by Nonlinear Mixed-Effect Modeling (NONMEM). MTX pharmacokinetic properties analysis was executed using the one-compartment pharmacokinetic model which incorporated first-order conditional estimation methods with interaction. Besides, the impact of genetic factors and demographic factors on MTX disposition were explored. Results: All the genotypes of steady-state plasma concentrations and OATP1B1 rs4149056, OATP1B1 rs2306283, and OATP1B3 rs7311358 were determined. The detected blood drug concentration reached the standard. Genotypes were all measured. At the same time, the population pharmacokinetic model of methotrexate was obtained CL(L·h-1) =8.25× e0.167× SNP (SNP: SLCO1B1 388A/A=3; SLCO1B1 388A/G=2; SLCO1B1 388G/G=1); V(L)= 32.8; Ka(h- 1)=1.69. Conclusion: : In our study, it was showed that OATP1B1-388 G>A SNP had a significant effect on CL/F. The factor should be considered when determining MTX dosing. However, prospective studies with a large number of participants are needed to validate the results of this study.

Genetic studies of autism spectrum disorder (ASD) have revealed multigene variations that converge on synaptic dysfunction. DOCK4, a gene at 7q31.1 that encodes the Rac1 guanine nucleotide exchange factor Dock4, has been identified as a risk gene for ASD and other neuropsychiatric disorders. However, whether and how Dock4 disruption leads to ASD features through a synaptic mechanism remain unexplored. We generated and characterized a line of Dock4 knockout (KO) mice, which intriguingly displayed a series of ASD-like behaviors, including impaired social novelty preference, abnormal isolation-induced pup vocalizations, elevated anxiety, and perturbed object and spatial learning. Mice with conditional deletion of Dock4 in hippocampal CA1 recapitulated social preference deficit in KO mice. Examination in CA1 pyramidal neurons revealed that excitatory synaptic transmission was drastically attenuated in KO mice, accompanied by decreased spine density and synaptic content of AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)- and NMDA (N-methyl-D-aspartate)-type glutamate receptors. Moreover, Dock4 deficiency markedly reduced Rac1 activity in the hippocampus, which resulted in downregulation of global protein synthesis and diminished expression of AMPA and NMDA receptor subunits. Notably, Rac1 replenishment in the hippocampal CA1 of Dock4 KO mice restored excitatory synaptic transmission and corrected impaired social deficits in these mice, and pharmacological activation of NMDA receptors also restored social novelty preference in Dock4 KO mice. Together, our findings uncover a previously unrecognized Dock4-Rac1-dependent mechanism involved in regulating hippocampal excitatory synaptic transmission and social behavior.

Neuroligins (NLs) are postsynaptic cell-adhesion proteins that play important roles in synapse formation and the excitatory-inhibitory balance. They have been associated with autism in both human genetic and animal model studies, and affect synaptic connections and synaptic plasticity in several brain regions. Yet current research mainly focuses on pyramidal neurons, while the function of NLs in interneurons remains to be understood. To explore the functional difference among NLs in the subtype-specific synapse formation of both pyramidal neurons and interneurons, we performed viral-mediated shRNA knockdown of NLs in cultured rat cortical neurons and examined the synapses in the two major types of neurons. Our results showed that in both types of neurons, NL1 and NL3 were involved in excitatory synapse formation, and NL2 in GABAergic synapse formation. Interestingly, NL1 affected GABAergic synapse formation more specifically than NL3, and NL2 affected excitatory synapse density preferentially in pyramidal neurons. In summary, our results demonstrated that different NLs play distinct roles in regulating the development and balance of excitatory and inhibitory synapses in pyramidal neurons and interneurons. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s12264-019-00347-y) contains supplementary material, which is available to authorized users.

Aim We aimed to investigate the genetic polymorphisms and pharmacogenetic variability associated with the pharmacodynamics (PD) and pharmacokinetics (PK) of prasugrel, in healthy Han Chinese subjects. Patients & methods Healthy, native, Han Chinese subjects (n = 36) aged 18 to 45 years with unknown genotypes were included. All subjects received a loading dose (LD) on day 1 and a maintenance dose (MD) from day 2 until day 11. Candidate gene association and gene-set analysis of biological pathways related to prasugrel and platelet activity were analyzed. Results 28 SNPs of 17 candidate genes previously associated with prasugrel or platelet activity were selected after a literature search. In the 30 mg LD groups (n = 24), ITGA2-rs28095 was found to be significantly associated with the P2Y12 reaction unit (PRU) value at 24 h after the LD (p = 0.015). 165 study genes related to platelet activation-related processes and prasugrel activity were selected from the MSigDB database, including curated gene sets from KEGG, Bio Carta, and Gene Cards. 14 SNPs of 9 genes were found to be significantly correlated both at 24 h and 12 days after LD: ADAMTSL1, PRKCA, ITPR2, P2RY12, P2RY14, PLCB4, PRKG1, ADCY1, and LYN. Seven SNPs of 6 protein-coding genes associated with area under the concentration-time curve (AUC0-tlast) were significantly identified among the 47 selected genes, including ADAMTSL1, CD36, P2RY1, PCSK9, PON1, and SCD. Conclusion These results show that genetic variation affects the PK and PD of prasugrel in normal individuals. Further studies with larger sample sizes are required to explore whether the SNPs are associated only with prasugrel activity or also with cardiovascular events and all-cause mortality.

Background Damage to the hippocampus will result in the loss of ability to form new long-term memories and cognitive disorders. At present, there is no effective medical treatment for this issue. Hippocampal cognitive prosthesis is proposed to replace damaged regions of the hippocampus to mimic the function of original biological tissue. This prosthesis requires a spike sorter to detect and classify spikes in the recorded neural signal. New method A 16-channel spike sorting processor is presented in this paper, where all channels are considered as independent. An automatic threshold estimation method suitable for hardware implementation is proposed for the Osort clustering algorithm. A new distance metric is also introduced to facilitate clustering. Bayes optimal template matching classification algorithm is optimized to reduce computational complexity by introducing a preselection mechanism. Results The chip was fabricated in 40-nm CMOS process with a core area of 0.0175 mm2/ch and power consumption of 19.0 μW/ch. Synthetic and realistic test data are used to evaluate the chip. The test result shows that it has high performance on both data. Comparison with existing method(s) Compared with the other three spike sorting processors, the proposed chip achieves the highest detection and classification accuracy. It also has the ability to deal with partially overlapping spikes, which is not reported in the other work. Conclusions We have developed a 16-channel spike sorting chip used in hippocampal prosthesis, which provides unsupervised clustering and real-time detection and classification. It also has the ability to deal with partially overlapping spikes.

Lung squamous cell carcinoma (LUSC) is one of the leading causes of tumor-driven deaths in the world. To date, studies on the tumor heterogeneity of LUSC at genomic level have only revealed limited therapeutic benefits. Therefore, system-wide research of LUSC at proteomic level may further improve precision medicine strategies on individual demands. To this end, we performed proteomic and phosphoproteomic study for LUSC samples of 25 Chinese patients. From our results, two subgroups (Cluster I and II) based on proteomic data were identified, which were associated with distinct molecular characteristics and clinicopathologic features. Combined with phosphoproteomic data, our result showed that spliceosome pathway was enriched in Cluster I, while focal adhesion pathway, immune-related pathways and Ras signaling pathway were enriched in Cluster II. In addition, we found that lymph node metastasis (LNM) was associated with our proteomic subgroups and cell cycle pathway was enriched in patients with LNM. Further analysis showed that MCM2, a DNA replication licensing factor involved in cell cycle pathway, was highly expressed in patients with poor prognosis, which was further proved by immunohistochemistry (IHC) analysis. In summary, our study provided a resource of the proteomic and phosphoproteomic features of LUSC in Chinese patients.

Autism spectrum disorder (ASD) and dyslexia are both neurodevelopmental disorders with high prevalence in children. Both disorders have strong genetic basis, and share similar social communication deficits co-occurring with impairments of reading or language. However, whether these two disorders share common genetic risks remain elusive. DOCK4 (dedicator for cytokinesis 4), a guanine nucleotide exchange factor (GEF) for the small GTPase Rac1, is one of few genes that are associated with both ASD and dyslexia. Dock4 is important for neuronal development and social behaviors. Two DOCK4 variations, Exon27-52 deletion (protein product: Dock4-945VS) and a missense mutation at rs2074130 (protein product: Dock4-R853H), are associated with dyslexia and/or ASD with reading difficulties. The present study explores the molecular and cellular functions of these two DOCK4 variants on neuronal development, by comparing them with the wild-type Dock4 protein. Notably, it is revealed that both mutants of Dock4 showed decreased ability to activate not only Rac1, but also another small GTPase Rap1. Consistently, both mutants were dysfunctional for regulation of cell morphology and cytoskeleton. Using Neuro-2a cells and hippocampus neurons as models, we found that both mutants had compromised function in promoting neurite outgrowth and dendritic spine formation. Electrophysiological recordings further showed that R853H partially lost the ability to promote excitatory synaptic transmission, whereas 945VS totally lost the ability. Together, we identified R853 as a previously uncharacterized site for the regulation of the integrity of Dock4 function, and provides insights in understanding the common molecular pathophysiology of ASD and dyslexia.

Specific inhibition of CDK9 is considered a promising strategy for developing effective anticancer therapeutics. However, most of the reported CDK9 inhibitors are still at an early stage of development and lack selectivity against other CDKs. Herein, we discovered coumarin derivative 30i as a potent CDK9 inhibitor with high selectivity (8300-fold over CDK7). Binding mode analysis illustrated that the substituent coumarin moiety is a critical group for CDK9 selectivity by occupying a flexible hinge/αD region, which is sterically hindered in other CDKs. Compound 30i showed excellent cellular antiproliferative activity, moderate pharmacokinetic property and low hERG inhibition. Moreover, 30i significantly induced tumour growth inhibition in a dose-dependent manner without causing an obvious loss of body weight in an MV4-11 xenograft mice model. Altogether, these results suggest that 30i may serve as a potential acute myeloid leukaemia (AML) therapeutics by selectively targeting CDK9.

Neuroligins (NLs) are a group of postsynaptic cell adhesion molecules that function in synaptogenesis and synaptic transmission. Genetic defects in neuroligin 3 (NL3), a member of the NL protein family, are associated with autism. Studies in rodents have revealed that mutations of NL3 gene lead to increased growth and complexity in dendrites in the central nervous system. However, the detailed mechanism is still unclear. In our study, we found that deficiency of NL3 led to morphological changes of the pyramidal neurons in layer II/III somatosensory cortex in mice, including enlarged somata, elongated dendritic length, and increased dendritic complexity. Knockdown of NL3 in cultured rat neurons upregulated Akt/mTOR signaling, resulting in both increased protein synthesis and dendritic growth. Treating neurons with either rapamycin to inhibit the mTOR or LY294002 to inhibit the PI3K/Akt activity rescued the morphological abnormalities resulting from either NL3 knockdown or knockout (KO). In addition, we found that the hyperactivated Akt/mTOR signaling associated with NL3 defects was mediated by a reduction in phosphatase and tensin (PTEN) expression, and that MAGI-2, a scaffold protein, interacted with both NL3 and PTEN and could be a linker between NL3 and Akt/mTOR signaling pathway. In conclusion, our results suggest that NL3 regulates neuronal morphology, especially dendritic outgrowth, by modulating the PTEN/Akt/mTOR signaling pathway, probably via MAGI-2. Thereby, this study provides a new link between NL3 and neuronal morphology.

N-methyl-D-aspartate receptors (NMDARs), a subtype of glutamate-gated ion channels, play a central role in epileptogenesis. Recent studies have identified an increasing number of GRIN2A (a gene encoding the NMDAR GluN2A subunit) mutations in patients with epilepsy. Phenotypes of GRIN2A mutations include epilepsy-aphasia disorders and other epileptic encephalopathies, which pose challenges in clinical treatment. Here we identified a heterozygous GRIN2A mutation (c.1341T>A, p.N447K) from a boy with Rolandic epilepsy by whole-exome sequencing. The patient became seizure-free with a combination of valproate and lamotrigine. Functional investigation was carried out using recombinant NMDARs containing a GluN2A-N447K mutant that is located in the ligand-binding domain of the GluN2A subunit. Whole-cell current recordings in HEK 293T cells revealed that the N447K mutation increased the NMDAR current density by ~1.2-fold, enhanced the glutamate potency by 2-fold, and reduced the sensitivity to Mg(2+) inhibition. These results indicated that N447K is a gain-of-function mutation. Interestingly, alternative substitutions by alanine and glutamic acid at the same residue (N447A and N447E) did not change NMDAR function, suggesting a residual dependence of this mutation in altering NMDAR function. Taken together, this study identified human GluN2A N447K as a novel mutation associated with epilepsy and validated its functional consequences in vitro. Identification of this mutation is also helpful for advancing our understanding of the role of NMDARs in epilepsy and provides new insights for precision therapeutics in epilepsy.

The growing amount of plastic solid waste (PSW) is a global concern. Despite increasing efforts to reduce the residual amounts of PSW to be disposed off through segregated collection and recycling, a considerable amount of PSW is still landfilled and the extent of PSW ocean pollution has become a worldwide issue. Particularly, polyethylene (PE) and polystyrene (PS) are considered as notably recalcitrant to biodegradation due to the carbon-carbon backbone that is highly resistant to enzymatic degradation via oxidative reactions. The present research investigated the catalytic mechanism of P450 monooxygenases by quantum mechanics to determine the bio-catalytic degradation of PE or PS. The findings indicated that the oxygenase-induced free radical transition caused the carbon-carbon backbone cleavage of aliphatic compounds. This work provides a fundamental knowledge of the biodegradation process of PE or PS at the atomic level and facilitates predicting the pathway of plastics’ biodegradation by microbial enzymes.

Huntington-interacting protein 1-related protein (HIP1R) was identified on the basis of its structural homology with HIP1. Based on its domain structure, HIP1R is a putative endocytosis-related protein. Our previous study had shown that knockdown of HIP1R induces a dramatic decrease of dendritic growth and branching in cultured rat hippocampal neurons. However, the underlying mechanism remains elucidative. In this study, we found that knockdown of HIP1R impaired the endocytosis of activated epidermal growth factor receptor (EGFR) and the consequent activation of the downstream ERK and Akt proteins. Meanwhile, it blocked the EGF-induced dendritic outgrowth. We also showed that the HIP1R fragment, amino acids 633–822 (HIP1R633–822), interacted with EGFR and revealed a dominant negative effect in disrupting the HIP1R-EGFR interaction-mediated neuronal development. Collectively, these results reveal a novel mechanism that HIP1R plays a critical role in neurite initiation and dendritic branching in cultured hippocampal neurons via mediating the endocytosis of EGFR and downstream signaling.

Background Our study aimed to investigate the roles of autophagy against high glucose induced response in retinal pigment epithelium (ARPE-19 cells). Methods The morphological changes and reactive oxygen species (ROS) generation in ARPE-19 cells under high glucose treatment were respectively detected using the transmission electron microscopy and flow cytometry. The expression levels of Parkin, PINK1, BNIP3L, LC3-I and LC3-II in ARPE-19 cells received high glucose treatment were measured by western blot after pretreatment of carbonyl cyanide m-chlorophenylhydrazone (CCCP), 3-methyladenine (3-MA), N-acetyl cysteine (NAC) or cyclosporin A (CsA) followed by high glucose treatment. Results ARPE-19 cells subjected to high glucose stress showed an obvious reduction in the LC3-I expression and significant increase in the number of autophagosomes, in the intracellular ROS level, and in the expression levels of Parkin, PINK1, BNIP3L and LC3-II (p < 0.05). Pretreatment with CCCP significantly reduced the LC3-I expression and increased the expression levels of Parkin, PINK1, BNIP3L and LC3-II (p < 0.05). ARPE-19 cells pretreated with CsA under high glucose stress showed markedly down-regulated expressions of Parkin, PINK1 and BNIP3L compared with the cells treated with high glucose (p < 0.05). Pretreatment of ARPE-19 cells with NAC or 3-MA under high glucose stress resulted in a marked reduction in the expression levels of PINK1, BNIP3L and LC3-II (p < 0.05). Meanwhile, the expression level of Parkin in the ARPE-19 cells pretreated with NAC under high glucose stress was comparable with that in the control cells. Conclusion Autophagy might have protective roles against high glucose induced injury in ARPE19 cells via regulating PINK1/Parkin pathway and BNIP3L.

Background Hemoporfin is a porphyrin-based photosensitizer and has been used for photodynamic therapy of port wine stain birthmarks in China. This study assessed the pharmacokinetics and cutaneous photosensitization of Hemoporfin in healthy volunteers. Methods Sixteen healthy subjects received a single intravenous infusion injection of Hemoporfin (5 mg/kg). The concentrations of Hemoporfin (MHD) and its metabolite Haematoporphyrin (HP) in plasma, urine and faeces were determined. The pharmacokinetic parameters were calculated. In addition, the cutaneous photosensitization was evaluated under the irradiation of solar simulator, 532 nm laser, and sunlight. Results The Cmax of MHD and HP were 46.7 ± 8.41 and 1.04 ± 0.265 μg/ml, respectively. The t1/2 of MHD and HP were 5.09 ± 0.945 and 5.71 ± 2.65 h, respectively. The AUC0-24h of MHD and HP were 29.8 ± 6.19 and 0.757 ± 0.285 h·μg/ml, respectively. The AUC0–∞ of MHD and HP were 29.8 ± 6.2 and 0.792 ± 0.308 h·μg/ml, respectively. The cumulative fecal excretion rate of MHD and HP were 45.3% and 1.05% at 96 h, respectively. Whereas, the cumulative urinary excretion rate of MHD was only 0.132% at 96 h. The concentration of HP in urine was less than 10% of MHD. After 52 h of administration, the cutaneous photosensitization associated with the exposure to various light sources was minimal. Conclusion MHD and HP were excreted mainly through the faeces after intravenous infusion. Hemoporfin associated cutaneous photosensitization was insignificant.

Developing therapeutic approaches that target neuronal differentiation will be greatly beneficial for the regeneration of neurons and synaptic networks in neurological diseases. Protein synthesis (mRNA translation) has recently been shown to regulate neurogenesis of neural stem/progenitor cells (NSPCs). However, it has remained unknown whether engineering translational machinery is a valid approach for manipulating neuronal differentiation. The present study identifies that a bivalent securinine compound SN3-L6, previously designed and synthesized by our group, induces potent neuronal differentiation through a novel translation-dependent mechanism. An isobaric tag for relative and absolute quantitation (iTRAQ)-based proteomic analysis in Neuro-2a progenitor cells revealed that SN3-L6 upregulated a group of neurogenic transcription regulators, and also upregulated proteins involved in RNA processing, translation, and protein metabolism. Notably, puromycylation and metabolic labeling of newly synthesized proteins demonstrated that SN3-L6 induced rapid and robust activation of general mRNA translation. Importantly, mRNAs of the proneural transcription factors Foxp1, Foxp4, Hsf1, and Erf were among the targets that were translationally upregulated by SN3-L6. Either inhibition of translation or knockdown of these transcription factors blocked SN3-L6 activity. We finally confirmed that protein synthesis of a same set of transcription factors was upregulated in primary cortical NPCs. These findings together identify a new compound for translational activation and neuronal differentiation, and provide compelling evidence that reprogramming transcriptional regulation network at translational levels is a promising strategy for engineering NSPCs.

Rac1, an important Rho GTPase that regulates actin cytoskeleton, has long been suggested to participate in acetylcholine receptor (AChR) clustering at the postsynaptic neuromuscular junction. However, how Rac1 is regulated and how it influences AChR clusters have remained unexplored. This study shows that breaking the balance of Rac1 regulation, by either increasing or decreasing its activity, led to impaired formation and maintenance of AChR clusters. By manipulating Rac1 activity at different stages of AChR clustering in cultured myotubes, we showed that Rac1 activation was required for the initial formation of AChR clusters, but its persistent activation led to AChR destabilization, and uncontrolled hyperactivation of Rac1 even caused excessive myotube fusion. Both AChR dispersal and myotube fusion induced by Rac1 were dependent on its downstream effector Pak1 (p21-activating kinase 1). Two Rac1 GAPs and Six Rac1 GEFs were screened to be important for normal AChR clustering. Together, this study reveals that whereas general Rac1 activity remains at low levels during terminal differentiation of myotubes and AChR cluster maintenance, tightly regulated Rac1 activity controls normal AChR clustering.

Background Several proteins have been identified as potential diagnostic biomarkers in imaging, genetic, or proteomic studies in Alzheimer disease (AD) patients and mouse models. However, biomarkers for presymptom diagnosis of AD are still under investigation, as are the presymptom molecular changes in AD pathogenesis. Objective In this study, we aim to analyzed the early proteomic changes in APPSw,Ind mice and to conduct further functional studies on interesting proteins. Methods We used the isobaric tags for relative and absolute quantitation (iTRAQ) approach combined with mass spectrometry to examine the early proteomic changes in hippocampi of APPSw,Ind mice. Quantitative reverse transcription polymerase chain reaction (RT-PCR) and immuno-blotting were performed for further validation. Finally, the functions of interesting proteins β-spectrin and Rab3a in APP trafficking and processing were tested by shRNA knockdown, in N2A cells stably expressing β-amyloid precursor protein (APP). Results The iTRAQ and RT-PCR results revealed the detailed molecular changes in oxidative stress, myelination, astrocyte activation, mTOR signaling and Rab3-dependent APP trafficking in the early stage of AD progression. Knock down of β -spectrin and Rab3a finally led to increased APP fragment production, indicating key roles of β-spectrin and Rab3a in regulating APP processing. Conclusion Our study provides the first insights into the proteomic changes that occur in the hippocampus in the early stages of the AD mouse model. In addition to improving the understanding of molecular alterations and functional cascades involved in early AD pathogenesis, our findings raise the possibility of developing potential biomarkers and therapeutic targets for early AD.

Huntingtin-interacting protein 1-related (HIP1R) protein is considered to be an endocytic adaptor protein like the other two members of the Sla2 family, Sla2p and HIP1. They all contain homology domains responsible for the binding of clathrin, inositol lipids and F-actin. Previous studies have revealed that HIP1R is highly expressed in different regions of the mouse brain and localizes at synaptic structures. However, the function of HIP1R in the nervous system remains unknown. In this study, we investigated HIP1R function in cultured rat hippocampal neurons using an shRNA knockdown approach. We found that, after HIP1R knockdown, the dynamics and density of dendritic filopodia, and dendritic branching and complexity were significantly reduced in developing neurons, as well as the densities of dendritic spines and PSD95 clusters in mature neurons. Moreover, HIP1R deficiency led to significantly reduced expression of the ionotropic glutamate receptor GluA1, GluN2A, and GluN2B subunits, but not the GABAA receptor α1 subunit. Similarly, HIP1R knockdown reduced the amplitude and frequency of the miniature excitatory postsynaptic current, but not of the miniature inhibitory postsynaptic current. In addition, the C-terminal proline-rich region of HIP1R responsible for cortactin binding was found to confer a dominant-negative effect on dendritic branching in cultured developing neurons, implying a critical role of cortactin binding in HIP1R function. Taken together, the results of our study suggest that HIP1R plays important roles in dendritic development and excitatory synapse formation and function.

PICK1 (protein interacting with C-kinase 1) is a peripheral membrane protein that interacts with diverse membrane proteins. PICK1 has been shown to regulate the clustering and membrane localization of synaptic receptors such as AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors, metabotropic glutamate receptor 7, and ASICs (acid-sensing ion channels). Moreover, recent evidence suggests that PICK1 can mediate the trafficking of various vesicles out from the Golgi complex in several cell systems, including neurons. However, how PICK1 affects vesicle-trafficking dynamics remains unexplored. Here, we show that PICK1 mediates vesicle trafficking by interacting with syntabulin, a kinesin-binding protein that mediates the trafficking of both synaptic vesicles and mitochondria in axons. Syntabulin recruits PICK1 onto microtubule structures and mediates the trafficking of PICK1-containing vesicles along microtubules. In neurons, syntabulin alters PICK1 expression by recruiting PICK1 into axons and regulates the trafficking dynamics of PICK1-containing vesicles. Furthermore, we show that syntabulin forms a complex with PICK1 and ASICs, regulates ASIC protein expression in neurons, and participates in ASIC-induced acidotoxicity.

Summary Neuroligins (NLs) are critical for synapse formation and function. NL3 R451C is an autism-associated mutation. NL3 R451C knockin (KI) mice exhibit autistic behavioral abnormalities, including social novelty deficits. However, neither the brain regions involved in social novelty nor the underlying mechanisms are clearly understood. Here, we found decreased excitability of fast-spiking interneurons and dysfunction of gamma oscillation in the medial prefrontal cortex (mPFC), which contributed to the social novelty deficit in the KI mice. Neuronal firing rates and phase-coding abnormalities were also detected in the KI mice during social interactions. Interestingly, optogenetic stimulation of parvalbumin interneurons in the mPFC at 40 Hz nested at 8 Hz positively modulated the social behaviors of mice and rescued the social novelty deficit in the KI mice. Our findings suggest that gamma oscillation dysfunction in the mPFC leads to social deficits in autism, and manipulating mPFC PV interneurons may reverse the deficits in adulthood.