Neuronal function and dysfunction of CYFIP2: from actin dynamics to early infantile epileptic encephalopathy

( Yinhua Zhang ),( Yeunkum Lee ),( Kihoon Han ) 생화학분자생물학회(구 한국생화학분자생물학회) 2019 BMB Reports Vol.52 No.5

The cytoplasmic FMR1-interacting protein family (CYFIP1 and CYFIP2) are evolutionarily conserved proteins originally identified as binding partners of the fragile X mental retardation protein (FMRP), a messenger RNA (mRNA)-binding protein whose loss causes the fragile X syndrome. Moreover, CYFIP is a key component of the heteropentameric WAVE regulatory complex (WRC), a critical regulator of neuronal actin dynamics. Therefore, CYFIP may play key roles in regulating both mRNA translation and actin polymerization, which are critically involved in proper neuronal development and function. Nevertheless, compared to CYFIP1, neuronal function and dysfunction of CYFIP2 remain largely unknown, possibly due to the relatively less well established association between CYFIP2 and brain disorders. Despite high amino acid sequence homology between CYFIP1 and CYFIP2, several in vitro and animal model studies have suggested that CYFIP2 has some unique neuronal functions distinct from those of CYFIP1. Furthermore, recent whole-exome sequencing studies identified de novo hot spot variants of CYFIP2 in patients with early infantile epileptic encephalopathy (EIEE), clearly implicating CYFIP2 dysfunction in neurological disorders. In this review, we highlight these recent investigations into the neuronal function and dysfunction of CYFIP2, and also discuss several key questions remaining about this intriguing neuronal protein. [BMB Reports 2019; 52(5): 304-311]

Differential cell-type-expression of CYFIP1 and CYFIP2 in the adult mouse hippocampus

Yinhua Zhang,강혜림,한기훈 한국통합생물학회 2019 Animal cells and systems Vol.23 No.6

Recent molecular genetic studies have suggested that two members of the cytoplasmic FMR1- interacting protein (CYFIP) gene family, CYFIP1 and CYFIP2, are causally associated with several brain disorders. However, the clinical features of individuals with CYFIP1 and CYFIP2 variants are quite different. In addition, null mice for either Cyfip1 or Cyfip2 are lethal, indicating that these two genes cannot compensate for each other in vivo. Although these results strongly suggest that CYFIP1 and CYFIP2 have distinct functions in vivo, the detailed mechanisms underlying their differences remain enigmatic and unexplored, especially considering their high sequence homology. To address this, we analyzed a recently established mouse brain single-cell RNA sequencing (scRNAseq) database and found that Cyfip1 and Cyfip2 are dominantly expressed in non-neurons and neurons, respectively, in all tested brain regions. To validate these observations, we performed fluorescent immunohistochemistry in the adult mouse hippocampus with either a CYFIP1 or CYFIP2 antibody combined with antibodies for various cell-type-specific markers. Consistent with our analysis of the scRNAseq database, CYFIP1 signals were detected in both neurons and astrocytes, while CYFIP2 signals were mainly detected in neurons. These results suggest differential cell-type-expression of CYFIP1 and CYFIP2 in vivo, which provides novel insights into our understanding of the pathophysiology of and potential treatments for CYFIP-associated brain disorders.

Smaller Body Size, Early Postnatal Lethality, and Cortical Extracellular Matrix-Related Gene Expression Changes of <i>Cyfip2</i> -Null Embryonic Mice

Zhang, Yinhua,Kang, Hyojin,Lee, Yeunkum,Kim, Yoonhee,Lee, Bokyoung,Kim, Jin Yong,Jin, Chunmei,Kim, Shinhyun,Kim, Hyun,Han, Kihoon Frontiers Media S.A. 2018 Frontiers in molecular neuroscience Vol.11 No.-

<P>Cytoplasmic FMR1-interacting protein 2 (CYFIP2) is a key component of the WAVE regulatory complex (WRC) which regulates actin polymerization and branching in diverse cellular compartments. Recent whole exome sequencing studies identified <I>de novo</I> hotspot variants in <I>CYFIP2</I> from patients with early-onset epileptic encephalopathy and microcephaly, suggesting that CYFIP2 may have some functions in embryonic brain development. Although perinatal lethality of <I>Cyfip2</I>-null (<I>Cyfip2</I><SUP>−/−</SUP>) mice was reported, the exact developmental time point and cause of lethality, and whether <I>Cyfip2</I><SUP>−/−</SUP> embryonic mice have brain abnormalities remain unknown. We found that endogenous <I>Cyfip2</I> is mainly expressed in the brain, spinal cord, and thymus of mice at late embryonic stages. <I>Cyfip2</I><SUP>−/−</SUP> embryos did not show lethality at embryonic day 18.5 (E18.5), but their body size was smaller than that of wild-type (WT) or <I>Cyfip2</I><SUP>+/−</SUP> littermates. Meanwhile, at postnatal day 0, all identified <I>Cyfip2</I><SUP>−/−</SUP> mice were found dead, suggesting early postnatal lethality of the mice. Nevertheless, the brain size and cortical cytoarchitecture were comparable among WT, <I>Cyfip2</I><SUP>+/−</SUP>, and <I>Cyfip2</I><SUP>−/−</SUP> mice at E18.5. Using RNA-sequencing analyses, we identified 98 and 72 differentially expressed genes (DEGs) from the E18.5 cortex of <I>Cyfip2</I><SUP>+/−</SUP> and <I>Cyfip2</I><SUP>−/−</SUP> mice, respectively. Further bioinformatic analyses suggested that extracellular matrix (ECM)-related gene expression changes in <I>Cyfip2</I><SUP>−/−</SUP> embryonic cortex. Together, our results suggest that CYFIP2 is critical for embryonic body growth and for early postnatal survival, and that loss of its expression leads to ECM-related gene expression changes in the embryonic cortex without severe gross morphological defects.</P>

A knowledge-based online fault detection method of the assembly process considering the relative poses of components

Yinhua Liu,Rui Sun,Yuwei Lu,Shiming Zhang 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.10

The real-time process fault detection in the multi-station assembly process is always a challenging problem for auto body manufactures. Traditionally, the fault diagnosis approaches for variation source identification are divided into two categories, i.e. the pattern matching methods and model-based estimation ones based on the collected data set. The measurements provide effective process monitoring, but the real-time process fault diagnosis in the assembly process is still difficult with the traditional diagnosis techniques, and always depends on the engineering experience in practice. Based on the assembly process knowledge, including multi-station assembly hierarchy, fixture scheme, measurement characteristics and tolerances etc. in the multi-station, a knowledge-based diagnostic methodology and procedures are proposed with the measurements of each body in white for part/component defections and faulty assembly station identification. For the station involved with defective parts/components, the sub-coordinate system of the part/component is established reflecting its position and pose in the space, and then the relative pose matrix to the “normally build” pose is calculated based on the deviations of sub-coordinates of the parts in this station. Finally, the assembly process malfunctions are determined by a proposed rule-based strategy with the relative pose matrix in real time. A simple 3 stations assembly process with 5 sheet metal parts was analyzed and compared with the traditional diagnostic method to verify the effectiveness and stability of the proposed method.

Excitatory and inhibitory synaptic dysfunction in mania: an emerging hypothesis from animal model studies

이연금,Yinhua Zhang,김신현,한기훈 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Bipolar disorder (BD) is a common psychiatric disorder characterized by recurrent mood swings between depression and mania, and is associated with high treatment costs. The existence of manic episodes is the defining feature of BD, during which period, patients experience extreme elevation in activity, energy, and mood, with changes in sleep patterns that together severely impair their ability to function in daily life. Despite some limitations in recapitulating the complex features of human disease, several rodent models of mania have been generated and characterized, which have provided important insights toward understanding its underlying pathogenic mechanisms. Among the mechanisms, neuronal excitatory and inhibitory (E/I) synaptic dysfunction in some brain regions, including the frontal cortex, hippocampus, and striatum, is an emerging hypothesis explaining mania. In this review, we highlight recent studies of rodent manic models having impairments in the E/I synaptic development and function. We also summarize the molecular and functional changes of E/I synapses by some mood stabilizers that may contribute to the therapeutic efficacy of drugs. Furthermore, we discuss potential future directions in the study of this emerging hypothesis to better connect the outcomes of basic research to the treatment of patients with this devastating mental illness.

Emerging roles of Lys63-linked polyubiquitination in neuronal excitatory postsynapses

Shinhyun Kim,Yinhua Zhang,Chunmei Jin,Yeunkum Lee,Yoonhee Kim,Kihoon Han 대한약학회 2019 Archives of Pharmacal Research Vol.42 No.4

In the mammalian brain, neuronal excitatory synaptic development, function, and plasticity largely rely on dynamic, activity-dependent changes in the macromolecular protein complex called the postsynaptic density (PSD). Activity-dependent Lys48-linked polyubiquitination and subsequent proteasomal degradation of key proteins in the PSD have been reported. However, investigations into the functions and regulatory mechanisms of Lys63-linked polyubiquitination, the second most abundant polyubiquitin form in synapses, have recently begun. Recent studies showed that a Lys63 linkage-specific deubiquitinase (DUB), cylindromatosis-associated DUB (CYLD) localizes to the PSD where its DUB activity is regulated by different kinases. In addition, Lys63-linked polyubiquitination of postsynaptic density 95 (PSD-95), a core scaffolding protein of the PSD, was identified and its functional significance in synaptic plasticity was characterized. In this review, we summarize these recent findings on Lys63-linked polyubiquitination in excitatory postsynapses, and also propose key questions and prospects about this emerging type of posttranslational modification of the PSD proteome.

Identification of Glycine Max MicroRNAs in Response to Phosphorus Deficiency

Aihua Sha,Yinhua Chen,Hongping Ba,Zhihui Shan,Xiaojuan Zhang,Xuejun Wu,Dezheng Qiu,Shuilian Chen,Xinan Zhou 한국식물학회 2012 Journal of Plant Biology Vol.55 No.4

MicroRNAs (miRNAs) are endogenous small RNAs regulating plant development and stress responses. In addition, phosphorus (P) is an important macronutrient for plant growth and development. More than two hundred miRNAs have been identified in Glycine Max and a few of miRNAs have been shown to respond to P deficiency,however, whether there are other miRNAs involved in P deficiency response is largely unknown. In this study, we used high-throughput small RNA sequencing and wholegenome-wide mining to identify the potential miRNAs in response to P deficiency. After sequencing, we deduced 183known, 99 conserved and 126 novel miRNAs in Glycine Max. Among them, in response to P deficiency, the expressions of 27 known, 16 conserved and 12 novel miRNAs showed significant changes in roots, whereas the expressions of 34known, 14 conserved and 7 novel miRNAs were significantly different in shoots. Furthermore, we validated the predicated novel miRNAs and found that three miRNAs in roots and five miRNAs in shoots responded to P deficiency. Some miRNAs were P-induced whereas some were P-suppressed. Together these results indicated that the miRNAs identified might play important roles in regulating P signaling pathway.

Cell-autonomous reduction of CYFIP2 is insufficient to induce Alzheimer’s disease-like pathologies in the hippocampal CA1 pyramidal neurons of aged mice

Ruiying Ma,Yinhua Zhang,Huiling Li,강혜림,김윤희,한기훈 한국통합생물학회 2023 Animal cells and systems Vol.27 No.1

Cytoplasmic FMR1-interacting protein 2 (CYFIP2) is an evolutionarily conserved multifunctionalprotein that regulates the neuronal actin cytoskeleton, mRNA translation and transport, andmitochondrial morphology and function. Supporting its critical roles in proper neuronaldevelopment and function, human genetic studies have repeatedly identified variants of theCYFIP2 gene in individuals diagnosed with neurodevelopmental disorders. Notably, a fewrecent studies have also suggested a mechanistic link between reduced CYFIP2 level andAlzheimer’s disease (AD). Specifically, in the hippocampus of 12-month-old Cyfip2heterozygous mice, several AD-like pathologies were identified, including increased levels ofTau phosphorylation and gliosis, and loss of dendritic spines in CA1 pyramidal neurons. However, detailed pathogenic mechanisms, such as cell types and their circuits where thepathologies originate, remain unknown for AD-like pathologies caused by CYFIP2 reduction. In this study, we aimed to address this issue by examining whether the cell-autonomousreduction of CYFIP2 in CA1 excitatory pyramidal neurons is sufficient to induce AD-likephenotypes in the hippocampus. We performed immunohistochemical, morphological, andbiochemical analyses in 12-month-old Cyfip2 conditional knock-out mice, which havepostnatally reduced CYFIP2 expression level in CA1, but not in CA3, excitatory pyramidalneurons of the hippocampus. Unexpectedly, we could not find any significant AD-likephenotype, suggesting that the CA1 excitatory neuron-specific reduction of CYFIP2 level isinsufficient to lead to AD-like pathologies in the hippocampus. Therefore, we propose thatCYFIP2 reduction in other neurons and/or their synaptic connections with CA1 pyramidalneurons may be critically involved in the hippocampal AD-like phenotypes of Cyfip2heterozygous mice.

Age-dependent decrease of GAD65/67 mRNAs but normal densities of GABAergic interneurons in the brain regions of <i>Shank3</i>-overexpressing manic mouse model

Lee, Bokyoung,Zhang, Yinhua,Kim, Yoonhee,Kim, Shinhyun,Lee, Yeunkum,Han, Kihoon Elsevier 2017 Neuroscience Letters Vol.649 No.-

<P><B>Abstract</B></P> <P>Dysfunction of inhibitory GABAergic interneurons is considered a major pathophysiological feature of various neurodevelopmental and neuropsychiatric disorders. The variants of <I>SHANK3</I> gene, encoding a core scaffold protein of the excitatory postsynapse, have been associated with numerous brain disorders. It has been suggested that abnormalities of GABAergic interneurons could contribute to the <I>SHANK3</I>-related disorders, but the limitation of these studies is that they used mainly <I>Shank3</I> knock-out mice. Notably, <I>Shank3</I>-overexpressing transgenic mice, modeling human hyperkinetic disorders, also show reduced inhibitory synaptic transmission, abnormal electroencephalography, and spontaneous seizures. However, it has not been investigated whether these phenotypes of <I>Shank3</I> transgenic mice are associated with GABAergic interneuron dysfunction, or solely due to the cell-autonomous postsynaptic changes of principal neurons. To address this issue, we investigated the densities of parvalbumin- and somatostatin-positive interneurons, and the mRNA and protein levels of GAD65/67 GABA-synthesizing enzymes in the medial prefrontal cortex, striatum, and hippocampus of adult <I>Shank3</I> transgenic mice. We found no significant difference in the measurements performed on wild-type versus <I>Shank3</I> transgenic mice, except for the decreased GAD65 or GAD67 mRNAs in these brain regions. Interestingly, only GAD65 mRNA was decreased in the hippocampus, but not mPFC and striatum, of juvenile <I>Shank3</I> transgenic mice which, unlike the adult mice, did not show behavioral hyperactivity. Together, our results suggest age-dependent decrease of GAD65/67 mRNAs but normal densities of certain GABAergic interneurons in the <I>Shank3</I> transgenic mice.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The densities of PV<SUP>+</SUP> and SOM<SUP>+</SUP> interneurons are normal in the <I>Shank3</I> transgenic mice. </LI> <LI> The protein levels of GAD65 and GAD67 are normal in the <I>Shank3</I> transgenic mice. </LI> <LI> The mRNA levels of GAD65 and GAD67 are age-dependently decreased in the <I>Shank3</I> transgenic mice. </LI> </UL> </P>

Reduced CYFIP2 Stability by Arg87 Variants Causing Human Neurological Disorders

Lee, Yeunkum,Zhang, Yinhua,Ryu, Jae Ryun,Kang, Hyae Rim,Kim, Doyoun,Jin, Chunmei,Kim, Yoonhee,Sun, Woong,Han, Kihoon John WileySons, Inc. 2019 Annals of neurology Vol.86 No.5