Yuichiro Itoh - Academia.edu (original) (raw)

Papers by Yuichiro Itoh

Scientific Reports, 2019

Multiple sclerosis (MS) is a neuroinflammatory multifocal disorder. Optic neuritis is common in M... more Multiple sclerosis (MS) is a neuroinflammatory multifocal disorder. Optic neuritis is common in MS and leads to visual disability. No current treatments repair this damage. Discerning gene expression changes within specific cell types in optic nerve (ON) may suggest new treatment targets for visual disability in MS. Astrocytes are pivotal regulators of neuroinflammation, playing either detrimental or beneficial roles. Here, we used RiboTag technology to characterize the astrocyte-specific transcriptome in oN in the experimental autoimmune encephalomyelitis (eAe) model of Ms. RNA sequencing analysis showed the Complement Cascade and Cholesterol Biosynthesis Pathways as the most enriched and de-enriched pathways, respectively, in ON astrocytes in EAE. Expression of complement component 3 (C3) was confirmed to be increased in ON astrocytes at the protein level during EAE. A bigger increase in C3 expressing ON astrocytes was found in EAE females versus healthy females, as compared to that in EAE males versus healthy males. Also, there was worse retinal ganglion cell (RGC) and axonal loss in EAE females. Regression analyses showed a negative correlation between C3 expressing astrocytes and RGC density. This cell-specific and sex-specific investigation of the optic nerve provides targets for the development of therapeutic strategies tailored for optic neuritis in Ms. The central nervous system (CNS) contains a variety of different cell types, whose composition and gene expression are altered during disease. Multiple sclerosis (MS) is characterized by immune cell infiltration, glia reactivity, demyelination, axonal damage and synaptic loss. MS patients experience a variety of disabilities in vision, walking, coordination, and cognition, with heterogeneity between patients regarding which disabilities are most severe, particularly early in disease. The neurodegenerative aspect of each disability likely has distinct features, since molecules and cells within each neurological pathway are not identical. Thus, we previously hypothesized that each neurological pathway needs to be specifically investigated in order to identify treatments tailored for each disability 1. Using a cell-and region-specific approach 2-4 , we showed regional differences in astrocyte gene expression among CNS regions in the experimental autoimmune encephalomyelitis (EAE) mouse model of MS 1. We found that cholesterol synthesis pathways were significantly downregulated in white matter rich region astrocytes (spinal cord, cerebellum and optic nerve) in EAE. Since cholesterol in astrocytes is transported via ApoE to oligodendrocytes to make myelin, and to neurons to make membranes and synapses, we treated EAE mice to reverse this abnormality. Treatment with an agonist for ATP-binding cassette transporter A1 (ABCA1) increased cholesterol synthesis in spinal cord astrocytes and improved motor function as shown using standard EAE walking scores and rotarod performance. Here, we extend our cell-specific and region-specific approach to optic nerve (ON), since optic neuritis is frequent in MS 5. Current MS treatments are anti-inflammatory and reduce relapses, thereby providing indirect neuroprotection. However treatments targeting CNS cells are needed for direct neuroprotection 6. Visual disability in MS

Multiple Sclerosis Journal, 2018

Background: Why are women more susceptible to multiple sclerosis, but men have worse disability p... more Background: Why are women more susceptible to multiple sclerosis, but men have worse disability progression? Sex differences in disease may be due to sex hormones, sex chromosomes, or both. Objective: Determine whether differences in sex chromosomes can contribute to sex differences in multiple sclerosis using experimental autoimmune encephalomyelitis. Methods: Sex chromosome transgenic mice, which permit the study of sex chromosomes not confounded by differences in sex hormones, were used to examine an effect of sex chromosomes on autoimmunity and neurodegeneration, focusing on X chromosome genes. Results: T-lymphocyte DNA methylation studies of the X chromosome gene Foxp3 suggested that maternal versus paternal imprinting of X chromosome genes may underlie sex differences in autoimmunity. Bone marrow chimeras with the same immune system but different sex chromosomes in the central nervous system suggested that differential expression of the X chromosome gene Toll-like receptor 7 i...

Proceedings of the National Academy of Sciences, 2017

Significance Molecular mechanisms underlying distinct disabilities during neurological diseases m... more Significance Molecular mechanisms underlying distinct disabilities during neurological diseases may differ based on the neurological pathway involved. Multiple sclerosis (MS) is multifocal, characterized by distinct disabilities affecting walking, vision, cognition, and fatigue. Neuroprotective treatments tailored for each disability may be more effective than nonspecific treatments aiming to reduce a composite of disabilities in clinical trials. Here, we use the MS model to apply a cell-specific and region-specific gene expression approach to discover targets in distinct neuroanatomic regions. Altered cholesterol synthesis gene expression in astrocytes in spinal cord and optic nerve was identified as a potential target for walking and visual disabilities, respectively. This disability-specific discovery approach represents a strategy for finding neuroprotective treatments for multifocal neurodegenerative diseases.

Circulation Research, 2015

Introduction: Sex differences in susceptibility to ischemia/reperfusion (I/R) injury have been mo... more Introduction: Sex differences in susceptibility to ischemia/reperfusion (I/R) injury have been mostly attributed to sex hormones. Recently we examined the role of sex chromosomes in sex differences in myocardial I/R injury. We discovered that gonadectomized mice with two X chromosomes (XX or XXY) have ~50% larger infarct size after I/R injury, compared to mice with one X chromosome (XY or XO). Only few X genes escape X inactivation and are expressed higher in XX than XY individuals. Here we examined the role of “X escapee” histone demethylase Kdm6a which is important in cardiac development. Methods: Female mice with a heterozygous global knockout of Kdm6a (Kdm6a+/-) and with 2 copies of Kdm6a (Kdm6a+/+, regular WT) were used. Isolated mouse hearts were subjected to 30 min global normothermic ischemia followed by 60 min reperfusion. RNA-Seq analysis was performed by comparing gene expression in hearts of Kdm6a+/+ vs. Kdm6a+/- females at baseline before ischemia. We calculated an unbi...

In mouse and humans , each tissue has a distinct distribution of M:F ratios, but in each case the... more In mouse and humans , each tissue has a distinct distribution of M:F ratios, but in each case the distribution for X genes (red line) fits closely to the distribution for A genes (dotted black line). LB, lymphoblastoid cell lines. PBM cells, peripheral blood mononuclear cells. Arrows point to regions where the X and A curves diverge, or to the inflection point in the mouse adipose tissue curve.<b>Copyright information:</b>Taken from "Dosage compensation is less effective in birds than in mammals"http://jbiol.com/content/6/1/2Journal of Biology 2007;6(1):2-2.Published online 22 Mar 2007PMCID:PMC2373894.

M:F ratios in zebra finches, in adult brain, liver, and kidney, and brain of post-hatch day 1 (P1... more M:F ratios in zebra finches, in adult brain, liver, and kidney, and brain of post-hatch day 1 (P1). Autosomal genes (A) are represented by the black dotted line, Z genes (Z) by the red line. The vertical dashed line is centered at a M:F ratio of 1 (logratio of 0). M:F ratios of embryonic chick brain, liver and heart. In each case Z genes are expressed at higher M:F ratios than A genes. In (b) the panel on the far right shows distributions for brain of individual chromosomes containing more than 50 genes. In all panels in (a) and (b) the rightmost bin (at the rightmost mark on the abscissa) includes all genes with M:F ratios at that value or greater, and the leftmost bin includes all genes with M:F ratios at that value or smaller. Z:A ratios of five male and five female chicken samples for heart (H), brain (B) and liver (L).<b>Copyright information:</b>Taken from "Dosage compensation is less effective in birds than in mammals"http://jbiol.com/content/6/1/2Journa...

Sex differences in physiology and disease in mammals result from the effects of three classes of ... more Sex differences in physiology and disease in mammals result from the effects of three classes of factors that are inherently unequal in males and females: reversible (activational) effects of gonadal hormones, permanent (organizational) effects of gonadal hormones, and cell-autonomous effects of sex chromosomes, as well as genes driven by these classes of factors. Often, these factors act together to cause sex differences in specific phenotypes, but the relative contribution of each and the interactions among them remain unclear. Here, we used the Four Core Genotypes (FCG) mouse model with or without hormone replacement to distinguish the effects of each class of sex-biasing factors on transcriptome regulation in liver and adipose tissues. We found that the activational hormone levels have the strongest influence on gene expression, followed by the organizational gonadal sex effect and, lastly, sex chromosomal effect, along with interactions among the three factors. Tissue specifici...

Aging is a risk factor for cognitive decline and susceptibility to neurodegenerative diseases. So... more Aging is a risk factor for cognitive decline and susceptibility to neurodegenerative diseases. Some aspects of aging, like the loss of sex hormones, may be preventable. Menopause is associated with cognitive deficits and brain atrophy. Since standard hormone replacement therapy (HRT) does not mitigate these brain aging outcomes, a gap in knowledge involves understanding brain region-specific, cell-specific, and receptor-specific mechanisms underlying this neurodegeneration. Here, cognitive testing and in vivo magnetic resonance imaging demonstrated that ovarian hormones in female mice at midlife protect against hippocampal-dependent cognitive impairment and dorsal hippocampal atrophy. Further, this neuroprotection in females at midlife is lost in mice with selective deletion of estrogen receptor beta (ERβ) in astrocytes, but not neurons. This preclinical evidence identifies ERβ in astrocytes as a novel therapeutic target to prevent hippocampal-dependent cognitive deficits and reduce...

Journal of Clinical Investigation, 2019

This sex difference of KDM6A gene expression was confirmed in human naive CD4 + T cells (Figure 1... more This sex difference of KDM6A gene expression was confirmed in human naive CD4 + T cells (Figure 1E). That other genes thought to escape X inactivation do not appear when comparing female versus male CD4 + T cell data sets may be due to a variety of factors, such as the tissue type, cell type, or hormonal status (28). We then used the FCG mouse model (20, 21), which allows comparison of XX and XY‾ mice of the same gonadal sex (Y‾ denotes lack of the testis-determining Sry gene on the Y chromosome). In addition, XX and XY‾ gonadal females were ovariectomized to remove activational effects of ovarian hormones. In autoantigen-stimulated CD4 + T cells from C57BL/6J and SJL mice, there was higher expression of Kdm6a and Kdm5c in XX compared with XY‾ mice (Figure 1, C and D, and Supplemental Figure 1, B and C). In contrast, other genes thought to escape X inactivation, namely, Ddx3x, Eif2s3x, Uba1, and Usp9x, were not differentially expressed between XX and XY‾ CD4 + T cells (Supplemental Figure 1, B and C). cKO mice are protected from EAE. Since Kdm6a was the most differentially expressed X escapee, we next investigated to determine whether Kdm6a expression in CD4 + T cells influences autoimmune disease. We crossed mice containing homozygous floxed Kdm6a alleles with mice expressing Cre under the CD4 promoter to produce a conditional KO of Kdm6a only in CD4 + T cells (cKO). Deletion of Kdm6a in CD4 + T cells was confirmed with genomic PCR (Figure 2A). As expected, expression of Kdm6a was decreased in cKO compared with WT in the CD4 + T cells from EAE mice that were stimulated with autoantigen (Figure 2B, FDR = 0.07). To examine the functional significance of Kdm6a expression in CD4 + T cells on disease, active EAE was induced in female cKO and WT (littermate controls; CD4-Cre negative) mice (Figure 2C). EAE clinical scores of cKO mice were lower than those in WT mice (P < 0.0001), demonstrating that deletion of Kdm6a in CD4 + T cells was protective. This protective effect of Kdm6a deletion in CD4 + T cells was further confirmed with 3 additional EAE experiments, including 1 experiment in males (Table 1). Together, these data show that the presence of Kdm6a in CD4 + T cells is disease promoting in the classic CD4 + T cellmediated autoimmune disease EAE. Consistent with an amelioration of clinical EAE scores, immunohistochemistry of spinal cord white matter showed a reduction of CD3 + T lymphocytes and Iba1 + globoid macrophages in cKO compared with WT mice (Figure 2, D and E). Assessment of neurodegeneration in spinal cord white matter showed reduction of βAPP + injured axons and an increase in

JAMA Neurology, 2016

IMPORTANCE Multiple sclerosis (MS) is characterized by progressive gray matter (GM) atrophy that ... more IMPORTANCE Multiple sclerosis (MS) is characterized by progressive gray matter (GM) atrophy that strongly correlates with clinical disability. However, whether localized GM atrophy correlates with specific disabilities in patients with MS remains unknown. OBJECTIVE To understand the association between localized GM atrophy and clinical disability in a biology-driven analysis of MS. DESIGN, SETTING, AND PARTICIPANTS In this cross-sectional study, magnetic resonance images were acquired from 133 women with relapsing-remitting MS and analyzed using voxel-based morphometry and volumetry. A regression analysis was used to determine whether voxelwise GM atrophy was associated with specific clinical deficits. Data were collected from June 28, 2007, to January 9, 2014. MAIN OUTCOMES AND MEASURES Voxelwise correlation of GM change with clinical outcome measures (Expanded Disability Status Scale and Multiple Sclerosis Functional Composite scores). RESULTS Among the 133 female patients (mean [SD] age, 37.4 [7.5] years), worse performance on the Multiple Sclerosis Functional Composite correlated with voxelwise GM volume loss in the middle cingulate cortex (P < .001) and a cluster in the precentral gyrus bilaterally (P = .004). In addition, worse performance on the Paced Auditory Serial Addition Test correlated with volume loss in the auditory and premotor cortices (P < .001), whereas worse performance on the 9-Hole Peg Test correlated with GM volume loss in Brodmann area 44 (Broca area; P = .02). Finally, voxelwise GM loss in the right paracentral lobulus correlated with bowel and bladder disability (P = .03). Thus, deficits in specific clinical test results were directly associated with localized GM loss in clinically eloquent locations. CONCLUSIONS AND RELEVANCE These biology-driven data indicate that specific disabilities in MS are associated with voxelwise GM loss in distinct locations. This approach may be used to develop disability-specific biomarkers for use in future clinical trials of neuroprotective treatments in MS.

Endocrinology, 2013

Three different models of MF1 strain mice were studied to measure the effects of gonadal secretio... more Three different models of MF1 strain mice were studied to measure the effects of gonadal secretions and sex chromosome type and number on body weight and composition, and on related metabolic variables such as glucose homeostasis, feeding, and activity. The 3 genetic models varied sex chromosome complement in different ways, as follows: 1) “four core genotypes” mice, comprising XX and XY gonadal males, and XX and XY gonadal females; 2) the XY* model comprising groups similar to XO, XX, XY, and XXY; and 3) a novel model comprising 6 groups having XO, XX, and XY chromosomes with either testes or ovaries. In gonadally intact mice, gonadal males were heavier than gonadal females, but sex chromosome complement also influenced weight. The male/female difference was abolished by adult gonadectomy, after which mice with 2 sex chromosomes (XX or XY) had greater body weight and percentage of body fat than mice with 1 X chromosome. A second sex chromosome of either type, X or Y, had similar ef...

Biology of sex differences, 2015

The majority of preclinical biomedical research involves studies of males rather than females. It... more The majority of preclinical biomedical research involves studies of males rather than females. It is thought that researchers have avoided females based on the idea that female traits are more variable than those of males because of cyclic variation in effects of ovarian hormones. To test the assumption of inherently greater female variability, we analyzed 293 microarray datasets measuring gene expression in various tissues of mice and humans, comprising analysis of more than 5 million probes. Meta-analysis showed that on average, male gene expression is slightly more variable than that of females although the difference is small. We also tested if the X chromosome of humans shows greater variability in gene expression in males than in females, as might be expected because of hemizygous exposure of polymorphic X alleles but again found little sex difference. Our analysis supports and extends previous studies reporting no overall greater phenotypic variability in females.

Proceedings of the National Academy of Sciences

Regional differences in neurons, astrocytes, oligodendrocytes, and microglia exist in the brain d... more Regional differences in neurons, astrocytes, oligodendrocytes, and microglia exist in the brain during health, and regional differences in the transcriptome may occur for each cell type during neurodegeneration. Multiple sclerosis (MS) is multifocal, and regional differences in the astrocyte transcriptome occur in experimental autoimmune encephalomyelitis (EAE), an MS model. MS and EAE are characterized by inflammation, demyelination, and axonal damage, with minimal remyelination. Here, RNA-sequencing analysis of MS tissues from six brain regions suggested a focus on oligodendrocyte lineage cells (OLCs) in corpus callosum. Olig1-RiboTag mice were used to determine the translatome of OLCs in vivo in corpus callosum during the remyelination phase of a chronic cuprizone model with axonal damage. Cholesterol-synthesis gene pathways dominated as the top up-regulated pathways in OLCs during remyelination. In EAE, remyelination was induced with estrogen receptor-β (ERβ) ligand treatment, a...

Brain and behavior, 2018

Progressive gray matter (GM) atrophy is a hallmark of multiple sclerosis (MS). Cognitive impairme... more Progressive gray matter (GM) atrophy is a hallmark of multiple sclerosis (MS). Cognitive impairment has been observed in 40%-70% of MS patients and has been linked to GM atrophy. In a phase 2 trial of estriol treatment in women with relapsing-remitting MS (RRMS), higher estriol levels correlated with greater improvement on the paced auditory serial addition test (PASAT) and imaging revealed sparing of localized GM in estriol-treated compared to placebo-treated patients. To better understand the significance of this GM sparing, the current study explored the relationships between the GM sparing and traditional MRI measures and clinical outcomes. Sixty-two estriol- and forty-nine placebo-treated RRMS patients underwent clinical evaluations and brain MRI. Voxel-based morphometry (VBM) was used to evaluate voxelwise GM sparing from high-resolution T1-weighted scans. A region of treatment-induced sparing (TIS) was defined as the areas where GM was spared in estriol- as compared to placeb...

PLOS ONE

Drug repurposing is an efficient approach in new treatment development since it leverages previou... more Drug repurposing is an efficient approach in new treatment development since it leverages previous work from one disease to another. While multiple sclerosis (MS), Parkinson's disease (PD), and Alzheimer's disease (AD) are all neurodegenerative diseases of the central nervous system (CNS) and differ in many clinical and pathological aspects, it is possible that they may share some mechanistic features. We hypothesized that focusing on gene expression in a CNS cell type specific manner might uncover similarities between diseases that could be missed using whole tissue gene expression analyses. We found similarities and differences in gene expression in these three distinct diseases, depending upon cell type. Microglia genes were increased in all three diseases, and gene expression levels were correlated strongly among these three neurodegenerative diseases. In astrocytes and endothelia, upregulation and correlations were observed only between MS and PD, but not AD. Neuronal genes were down-regulated in all three diseases, but correlations of changes of individual genes between diseases were not strong. Oligodendrocyte showed gene expression changes that were not shared among the three diseases. Together these data suggest that treatments targeting microglia are most amenable to drug repurposing in MS, PD, and AD, while treatments targeting other CNS cells must be tailored to each disease.

Chromosome Res, 2001

Contigs of genomic clones covering about 480 kb on the terminal region of the short arm of chicke... more Contigs of genomic clones covering about 480 kb on the terminal region of the short arm of chicken W chromosome were obtained. By applying the exon trapping procedure on this whole region, a chicken homolog of spindlin gene, chSpin-W, was identi¢ed and subcloned. A counterpart gene, chSpin-Z, was found near the centromere on the long arm of Z chromosome. Although protein-coding regions of both genes are nearly identical, a part of the 3 H-untranslated region is suf¢ciently different to distinguish the transcript of chSpin-W. Both chSpin-W and chSpin-Z are transcribed in early embryos. chSpin-Z is transcribed in various tissues of adult chickens, while chSpin-W is transcribed most prominently in ovarian granulosa and thecal cells. When female chicken embryonic ¢broblasts were transfected with a cDNA construct for red £uorescent protein or green £uorescent protein-fused spindlin or FLAG-tagged spindlin, the expressed spindlin was co-localized with SUMO-1 in nuclear dots, ND10, in interphase cells, while the expressed spindlin was localized on entire chromosomes during mitosis. The localization of spindlin in ND10 reappeared after mitosis in daughter cell nuclei. A C-terminal region of spindlin was suggested to be required for the localization of spindlin to ND10.

Handbook of Experimental Pharmacology, 2012

A modern general theory of sex determination and sexual differentiation identifies the factors th... more A modern general theory of sex determination and sexual differentiation identifies the factors that cause sexual bias in gene networks, leading to sex differences in physiology and disease. The primary sex-biasing factors are those encoded on the sex chromosomes that are inherently different in the male and female zygotes. These factors, and downstream factors such as gonadal hormones, act directly on tissues to produce sex differences and antagonize each other to reduce sex differences. Recent studies of mouse models such as the four core genotypes have begun to distinguish between the direct effects of sex chromosome complement (XX vs. XY) and hormonal effects. Several lines of evidence implicate epigenetic processes in the control of sex differences, although a great deal of information is needed about sex differences in the epigenome.

Developmental Dynamics, 2013

The classic model of sex determination in mammals states that the sex of the individual is determ... more The classic model of sex determination in mammals states that the sex of the individual is determined by the type of gonad that develops, which in turn determines the gonadal hormonal milieu that creates sex differences outside of the gonads. However, XX and XY cells are intrinsically different because of the cell-autonomous sex-biasing action of X and Y genes. Recent studies of mice, in which sex chromosome complement is independent of gonadal sex, reveal that sex chromosome complement has strong effects contributing to sex differences in phenotypes such as metabolism. Adult mice with two X chromosomes (relative to mice with one X chromosome) show dramatically greater increases in body weight and adiposity after gonadectomy, irrespective of their gonadal sex. When fed a high fat diet, XX mice develop striking hyperinsulinemia and fatty liver, relative to XY mice. The sex chromosome effects are modulated by the presence of gonadal hormones, indicating an interaction of the sex-biasing effects of gonadal hormones and sex chromosome genes. Other cell-autonomous sex chromosome effects are detected in mice in many phenotypes. Birds (relative to eutherian mammals) are expected to show more widespread cell-autonomous sex determination in non-gonadal tissues, because of ineffective sex chromosome dosage compensation mechanisms.

Philosophical Transactions of the Royal Society B: Biological Sciences, 2016

Historically, it was thought that the number of X chromosomes plays little role in causing sex di... more Historically, it was thought that the number of X chromosomes plays little role in causing sex differences in traits. Recently, selected mouse models have been used increasingly to compare mice with the same type of gonad but with one versus two copies of the X chromosome. Study of these models demonstrates that mice with one X chromosome can be strikingly different from those with two X chromosomes, when the differences are not attributable to confounding group differences in gonadal hormones. The number of X chromosomes affects adiposity and metabolic disease, cardiovascular ischaemia/reperfusion injury and behaviour. The effects of X chromosome number are likely the result of inherent differences in expression of X genes that escape inactivation, and are therefore expressed from both X chromosomes in XX mice, resulting in a higher level of expression when two X chromosomes are present. The effects of X chromosome number contribute to sex differences in disease phenotypes, and may...