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Studies on the effects of glyphosate (GlyP) and glyphosate‐based herbicides (GBHs) on cerebellar development are extremely limited. This study examined the effects of maternal exposure to GlyP and GBH on rat cerebellar development in male offspring. From day 6 of gestation until day 21 postpartum at weaning, dams were given GlyP at 1.5% or 3.0% in diet or GBH at 1.0% in drinking water (corresponding to 0.36% GlyP). At weaning, GBH exposure was linked to increased numbers of DCX+ migrating granule cells in the cortex and TUNEL+ apoptotic cells in the internal granular layer (IGL), suggesting the disappearance of mismigrated granule cells via apoptosis. GBH also upregulated Nr4a3 and downregulated Cdk5 in the cerebellar vermis, suggesting a causal relation with the impaired granule cell development at this time. GlyP (3.0%) tended to increase in the number of DCX+ migrating granule cells in the IGL and upregulated Nr4a3 at weaning. Both compounds also upregulated genes related to granule cell migration (Astn1, Astn2, Nfia, and/or Nfix) at weaning and in adulthood, which might be an ameliorative response to delayed granule cell migration. Moreover, GBH induced Purkinje cell misalignment at weaning, which could be the result of delayed granule cell migration. In adulthood, GBH was associated with upregulation of the reelin signaling‐related genes Reln, Dab1, and Efnb1, suggesting a compensatory response to Purkinje cell misalignment. GlyP induced the same gene expression changes. These results suggest that GBH reversibly disrupts cerebellar development, primarily by targeting granule cell migration and differentiation, whereas GlyP exhibited similar toxic potential as GBH. [ABSTRACT FROM AUTHOR]

Ochratoxin A (OTA) is a mycotoxin that causes renal carcinogenicity following the induction of karyomegaly in proximal tubular cells after repeated administration to rats. Here, we performed gene profiling regarding altered DNA methylation and gene expression in the renal tubules focusing on the mechanism of OTA‐induced carcinogenesis. For this purpose, OTA or 3‐chloro‐1,2‐propanediol (3‐MCPD), a renal carcinogen not inducing karyomegaly, was administered to rats for 13 weeks, and DNA methylation array and RNA sequencing analyses were performed on proximal tubular cells. Genes for which OTA altered the methylation status and gene expression level, after excluding genes showing similar expression changes by 3‐MCPD, were subjected to confirmation analysis of the transcript level by real‐time reverse‐transcription PCR. Gene Ontology (GO)‐based functional annotation analysis of validated genes revealed a cluster of hypermethylated and downregulated genes enriched under the GO term "mitochondrion," such as those associated with metabolic reprogramming in carcinogenic process (Clpx, Mrpl54, Mrps34, and Slc25a23). GO terms enriched for hypomethylated and upregulated genes included "response to arsenic‐containing substance," represented by Cdkn1a involved in cell cycle arrest, and "positive regulation of IL‐17 production," represented by Osm potentiating cell proliferation promotion. Other genes that did not cluster under any GO term included Lrrc14 involved in NF‐κB‐mediated inflammation, Gen1 linked to DNA repair, Has1 related to chromosomal aberration, and Anxa3 involved in tumor development and progression. In conclusion, a variety of genes engaged in carcinogenic processes were obtained by epigenetic gene profiling in rat renal tubular cells specific to OTA treatment for 13 weeks. The present study investigated comprehensive gene profiles regarding DNA methylation and gene expression in rat renal tubules after 13‐week administration of ochratoxin A (OTA), a karyomegaly‐inducing renal carcinogen. OTA‐specific genes were obtained by excluding those responding to 3‐MCPD, a renal carcinogen not inducing karyomegaly. Genes obtained included those associated with metabolic reprogramming, cell cycle arrest, cell proliferation facilitation, inflammation, DNA repair, chromosomal aberration, and tumor development and progression, suggesting that various gene functions are epigenetically engaged in OTA‐specific carcinogenic processes. [ABSTRACT FROM AUTHOR]

Near‐infrared photoimmunotherapy (NIR‐PIT) is a novel form of cancer treatment using conjugates of antibody against overexpressed antigens in cancers and photoabsorber IRDye700DX. HER2 is overexpressed in various cancers, for which molecular targeted therapy such as trastuzumab has been developed. The present study investigated the efficacy potential of HER2‐targeted NIR‐PIT using trastuzumab‐IRDye700DX conjugate (Tra‐IR700) in HER2‐positive breast cancer. We first examined the reactivity of Tra‐IR700 and the cytotoxicity of NIR‐PIT in vitro. HER2‐positive BT‐474 and SK‐BR‐3 cells and HER2‐negative BT‐20 cells were used. Tra‐IR700 fluorescence was only observed in HER2‐positive breast cancer cell lines, and the fluorescence was localized to the cell surface. Furthermore, HER2‐positive breast cancer cell lines treated with NIR‐PIT showed swelling and blebbing shortly after irradiation, and eventually increased PI‐positive dead cells. Next, tumor accumulation of Tra‐IR700 and tumor damage by NIR‐PIT were examined in vivo. Tra‐IR700 was administered intravenously to a xenograft model in which BT‐474 cells were implanted subcutaneously in BALB/c nude mice. Tra‐IR700 fluorescence was the highest in tumor tissue 1 day after administration, and the fluorescence was localized to the cell membrane of tumor cells. At this time point, NIR‐PIT resulted in diffuse necrosis of tumor tissues 1 day after irradiation. These results suggest that NIR‐PIT with Tra‐IR700 induces a highly selective therapeutic effect in a HER2‐positive breast cancer model. NIR‐PIT using Tra‐IR700 is expected to be a novel treatment for HER2‐positive cancers, including breast cancer. [ABSTRACT FROM AUTHOR]

We investigated the effect of lipopolysaccharide (LPS)‐induced maternal immune activation used as a model for producing neurodevelopmental disorders on hippocampal neurogenesis and behaviors in rat offspring by exploring the antioxidant effects of alpha‐glycosyl isoquercitrin (AGIQ). Pregnant Sprague–Dawley rats were intraperitoneally injected with LPS (50 μg/kg body weight) at gestational days 15 and 16. AGIQ was administered in the diet to dams at 0.5% (w/w) from gestational day 10 until weaning at postnatal day 21 and then to offspring until adulthood at postnatal day 77. During postnatal life, offspring of LPS‐injected animals did not show neuroinflammation or oxidative stress in the brain. At weaning, LPS decreased the numbers of type‐2b neural progenitor cells (NPCs) and PCNA+ proliferating cells in the subgranular zone, FOS‐expressing granule cells, and GAD67+ hilar interneurons in the dentate gyrus. In adulthood, LPS decreased type‐1 neural stem cells, type‐2a NPCs, and GAD67+ hilar interneurons, and downregulated Dpysl3, Sst, Fos, Mapk1, Mapk3, Grin2a, Grin2b, Bdnf, and Ntrk2. In adults, LPS suppressed locomotor activity in the open field test and suppressed fear memory acquisition and fear extinction learning in the contextual fear conditioning test. These results indicate that mid‐gestation LPS injections disrupt programming of normal neurodevelopment resulting in progressive suppression of hippocampal neurogenesis and synaptic plasticity of newborn granule cells by suppressing GABAergic and glutamatergic neurotransmitter signals and BDNF/TrkB signaling to result in adult‐stage behavioral deficits. AGIQ ameliorated most aberrations in hippocampal neurogenesis and synaptic plasticity, as well as behavioral deficits. Effective amelioration by continuous AGIQ treatment starting before LPS injections may reflect both anti‐inflammatory and anti‐oxidative stress effects during gestation and neuroprotective effects of continuous exposure through adulthood. [ABSTRACT FROM AUTHOR]

Aluminum (Al), a common light metal, affects the developing nervous system. Developmental exposure to Al chloride (AlCl3) induces aberrant neurogenesis by targeting neural stem cells (NSCs) and/or neural progenitor cells (NPCs) in the dentate gyrus (DG) of rats and mice. To investigate whether hippocampal neurogenesis is similarly affected by AlCl3 exposure in a general toxicity study, AlCl3 was orally administered to 5‐week‐old Sprague Dawley rats at dosages of 0, 4000, or 8000 ppm in drinking water for 28 days. AlCl3 downregulated Sox2 transcript level in the DG at the highest dosage and produced a dose‐dependent decrease of SOX2+ cells without altering numbers of GFAP+ or TBR2+ cells in the subgranular zone, suggesting that AlCl3 decreases Type 2a NPCs. High‐dose exposure downregulated Pcna, upregulated Pvalb, and altered expression of genes suggestive of oxidative stress induction (upregulation of Nos2 and downregulation of antioxidant enzyme genes), indicating suppressed proliferation and differentiation of Type 1 NSCs. AlCl3 doses also increased mature granule cells in the DG. Upregulation of Reln may have contributed to an increase of granule cells to compensate for the decrease of Type 2a NPCs. Moreover, upregulation of Calb2, Gria2, Mapk3, and Tgfb3, as well as increased numbers of activated astrocytes in the DG hilus, may represent ameliorating responses against suppressed neurogenesis. These results suggest that 28‐day exposure of young‐adult rats to AlCl3 differentially targeted NPCs and mature granule cells in hippocampal neurogenesis, yielding a different pattern of disrupted neurogenesis from developmental exposure. We previously showed that developmental exposure to aluminum chloride (AlCl3) disrupted hippocampal neurogenesis in rats and mice. The present study investigated whether hippocampal neurogenesis is similarly affected by AlCl3 exposure in a general toxicity study using young‐adult rats. AlCl3 exposure for 28 days decreased Type 2a NPCs but increased mature granule cells through multiple mechanisms, suggesting that AlCl3 differentially targeted NPCs and mature granule cells in hippocampal neurogenesis to generate different patterns of disruption from developmental exposure. [ABSTRACT FROM AUTHOR]

We have previously reported that the valproic acid (VPA)‐induced disruption pattern of hippocampal adult neurogenesis differs between developmental and 28‐day postpubertal exposure. In the present study, we performed brain region‐specific global gene expression profiling to compare the profiles of VPA‐induced neurotoxicity between developmental and postpubertal exposure. Offspring exposed to VPA at 0, 667, and 2000 parts per million (ppm) via maternal drinking water from gestational day 6 until weaning (postnatal day 21) were examined, along with male rats orally administered VPA at 0, 200, and 900 mg/kg body weight for 28 days starting at 5 weeks old. Four brain regions—the hippocampal dentate gyrus, corpus callosum, cerebral cortex, and cerebellar vermis—were subjected to expression microarray analysis. Profiled data suggested a region‐specific pattern of effects after developmental VPA exposure, and a common pattern of effects among brain regions after postpubertal VPA exposure. Developmental VPA exposure typically led to the altered expression of genes related to nervous system development (Msx1, Xcl1, Foxj1, Prdm16, C3, and Kif11) in the hippocampus, and those related to nervous system development (Neurod1) and gliogenesis (Notch1 and Sox9) in the corpus callosum. Postpubertal VPA exposure led to the altered expression of genes related to neuronal differentiation and projection (Cd47, Cyr61, Dbi, Adamts1, and Btg2) in multiple brain regions. These findings suggested that neurotoxic patterns of VPA might be different between developmental and postpubertal exposure, which was consistent with our previous study. Of note, the hippocampal dentate gyrus might be a sensitive target of developmental neurotoxicants after puberty. Global gene expression profiling was performed in four different brain regions in rats after developmental or postpubertal 28‐day valproic acid (VPA) exposure. Developmental VPA exposure had specific effects on each of the four brain regions, while postpubertal VPA exposure had common effects among multiple brain regions. Our results suggested that the neurotoxic pattern of VPA might differ between developmental and postpubertal exposure. They also suggested that the hippocampal dentate gyrus might be particularly vulnerable to postpubertal exposure to developmental neurotoxicants. [ABSTRACT FROM AUTHOR]

We have previously found that maternal exposure to 6‐propyl‐2‐thiouracil (PTU), valproic acid (VPA), or glycidol (GLY) has a sustained or late effect on hippocampal neurogenesis at the adult stage in rat offspring. Herein, we searched for genes with hypermethylated promoter region and downregulated transcript level to reveal irreversible markers of developmental neurotoxicity. The hippocampal dentate gyrus of male rat offspring exposed maternally to PTU, VPA, or GLY was subjected to Methyl‐Seq and RNA‐Seq analyses on postnatal day (PND) 21. Among the genes identified, 170 were selected for further validation analysis of gene expression on PND 21 and PND 77 by real‐time reverse transcription‐PCR. PTU and GLY downregulated many genes on PND 21, reflecting diverse effects on neurogenesis. Furthermore, genes showing sustained downregulation were found after PTU or VPA exposure, reflecting a sustained or late effect on neurogenesis by these compounds. In contrast, such genes were not observed with GLY, probably because of the reversible nature of the effects. Among the genes showing sustained downregulation, Creb, Arc, and Hes5 were concurrently downregulated by PTU, suggesting an association with neuronal mismigration, suppressed synaptic plasticity, and reduction in neural stem and progenitor cells. Epha7 and Pvalb were also concurrently downregulated by PTU, suggesting an association with the reduction in late‐stage progenitor cells. VPA induced sustained downregulation of Vgf and Dpysl4, which may be related to the aberrations in synaptic plasticity. The genes showing sustained downregulation may be irreversible markers of developmental neurotoxicity. Hippocampal dentate gyrus of rat offspring exposed maternally to PTU, VPA, or GLY was subjected to global methylation analysis on PND 21. Genes downregulated on PND 77 were examined. PTU concurrently downregulated Creb, Arc, and Hes5, suggesting an association with the diverse effects on neurogenesis. PTU also concurrently downregulated Epha7 and Pvalb, suggesting an association with progenitor cell reduction. VPA downregulated Vgf and Dpysl4, suggesting an association with the aberrant synaptic plasticity. In contrast, GLY did not induce sustained downregulation. [ABSTRACT FROM AUTHOR]

We previously found downregulation of low‐density lipoprotein receptor class A domain‐containing protein 4 (LDLRAD4), a negative regulator of transforming growth factor (TGF)‐β signaling, in glutathione S‐transferase placental form (GST‐P) expressing (+) pre‐neoplastic lesions produced by treatment with nongenotoxic hepatocarcinogens for up to 90 days in rats. Here, we investigated the relationship between LDLRAD4 downregulation and TGFβ signaling in nongenotoxic hepatocarcinogenesis. The transcripts of Tgfb and Hb‐egf increased after ≥28 days of treatment. After 84 or 90 days, Snai1 increased transcripts and the subpopulation of GST‐P+ foci downregulating LDLRAD4 co‐expressed TGFβ1, phosphorylated EGFR, or phosphorylated AKT2, and downregulated PTEN, showing higher incidences than those in GST‐P+ foci expressing LDLRAD4. The subpopulation of GST‐P+ foci downregulating LDLRAD4 also co‐expressed caveolin‐1 or TACE/ADAM17, suggesting that disruptive activation of TGFβ signaling through a loss of LDLRAD4 enhances EGFR and PTEN/AKT‐dependent pathways via caveolin‐1‐dependent activation of TACE/ADAM17 during nongenotoxic hepatocarcinogenesis. The numbers of c‐MYC+ cells and PCNA+ cells were higher in LDLRAD4‐downregulated GST‐P+ foci than in LDLRAD4‐expressing GST‐P+ foci, suggesting a preferential proliferation of pre‐neoplastic cells by LDLRAD4 downregulation. Nongenotoxic hepatocarcinogens markedly downregulated Nox4 after 28 days and later decreased cleaved caspase 3+ cells in LDLRAD4‐downregulated GST‐P+ foci, suggesting an attenuation of apoptosis by LDLRAD4 downregulation through activation of the EGFR pathway. At the late hepatocarcinogenesis stage in a two‐stage model, LDLRAD4 downregulation was higher in adenoma and carcinoma than in pre‐neoplastic cell foci, suggesting a role of LDLRAD4 downregulation in tumor development. Our results suggest that nongenotoxic hepatocarcinogens cause disruptive activation of TGFβ signaling through downregulating LDLRAD4 toward carcinogenesis in the rat liver. The present study investigated the relationship between LDLRAD4 downregulation and TGFβ signaling during nongenotoxic hepatocarcinogenesis in rats. Immunohistochemically, LDLRAD4‐downregulated GST‐P+ foci revealed a phenotype suggestive of disruptive activation of TGFβ signaling to enhance EGFR and PTEN/AKT‐dependent pathways via caveolin‐1‐dependent activation of TACE/ADAM17. The LDLRAD4‐downregulated foci also facilitated proliferation and attenuated apoptosis. Increased incidence of LDLRAD4 downregulation in neoplastic lesions suggested a role in tumor development. Thus, nongenotoxic hepatocarcinogens may cause disruptive activation of TGFβ signaling through downregulating LDLRAD4 toward hepatocarcinogenesis. [ABSTRACT FROM AUTHOR]

In human and dogs, bladder cancer (BC) is the most common neoplasm affecting the urinary tract. Dog BC resembles human muscle‐invasive BC in histopathological characteristics and gene expression profiles, and could be an important research model for this disease. Cancer patient‐derived organoid culture can recapitulate organ structures and maintains the gene expression profiles of original tumor tissues. In a previous study, we generated dog prostate cancer organoids using urine samples, however dog BC organoids had never been produced. Therefore we aimed to generate dog BC organoids using urine samples and check their histopathological characteristics, drug sensitivity, and gene expression profiles. Organoids from individual BC dogs were successfully generated, expressed urothelial cell markers (CK7, CK20, and UPK3A) and exhibited tumorigenesis in vivo. In a cell viability assay, the response to combined treatment with a range of anticancer drugs (cisplatin, vinblastine, gemcitabine or piroxicam) was markedly different in each BC organoid. In RNA‐sequencing analysis, expression levels of basal cell markers (CK5 and DSG3) and several novel genes (MMP28,CTSE,CNN3,TFPI2,COL17A1, and AGPAT4) were upregulated in BC organoids compared with normal bladder tissues or two‐dimensional (2D) BC cell lines. These established dog BC organoids might be a useful tool, not only to determine suitable chemotherapy for BC diseased dogs but also to identify novel biomarkers in human muscle‐invasive BC. In the present study, for the 1st time, dog BC organoids were generated and several specifically upregulated organoid genes were identified. Our data suggest that dog BC organoids might become a new tool to provide fresh insights into both dog BC therapy and diagnostic biomarkers. [ABSTRACT FROM AUTHOR]

Fluorescence tumor imaging using exogenous fluorescent tumor-targeting agents has potential to improve early tumor detection. The fluorescent contrast agent indocyanine green (ICG) is used in medical diagnostics. The aim of the present study is to investigate the tumor imaging capability and the imaging mechanism of i.v. administered ICG in a mouse model of colitis-associated colon cancer. To do this, an azoxymethane/dextran sodium sulfate-induced colon cancer mouse model was used. Ex vivo imaging experiments were carried out 1 hour after i.v. injection of ICG. The ICG fluorescence was observed in the colon tumor tissues, with sufficient tumor to normal tissue ratio, correlating with tumor malignancy. In the tumor tissues, ICG fluorescence was localized in the vascular interstitial tissue. Immunofluorescence microscopy revealed that tumor cells formed tight junctions normally, suggesting an inability of tumor cellular uptake of ICG. In contrast, tumor tissues increased the CD31-immunoreactive endothelial cell area, and accumulated stromal cells immunoreactive for COX-2 and tumor cell population immunoreactive for inducible nitric oxide synthase. In vivo vascular permeability assay revealed that prostaglandin E2 promoted the endothelial cell permeability of ICG. In conclusion, our data indicated that fluorescence contrast-enhanced imaging following i.v. administered ICG can be applied to the detection of colon tumors in a mouse colitis-associated colon cancer model. The tumor tissue preference of ICG in the present model can be attributed to the enhanced vascular leakage of ICG involving inflammatory mediators, such as COX-2 and inducible nitric oxide synthase, in conjunction with increased tumor vascularity. [ABSTRACT FROM AUTHOR]

Indocyanine green (ICG) is a fluorescent agent approved for clinical applications by the Food and Drug Administration and European Medicines Agency. This study examined the mechanism of tumor imaging using intravenously administered ICG. The in vivo kinetics of intravenously administered ICG were determined in tumor xenografts using microscopic approaches that enabled both spatio-temporal and high-magnification analyses. The mechanism of ICG-based tumor imaging was examined at the cellular level in six phenotypically different human colon cancer cell lines exhibiting different grades of epithelioid organization. ICG fluorescence imaging detected xenograft tumors, even those < 1 mm in size, based on their preferential cellular uptake and retention of the dye following its rapid tissue-non-specific delivery, in contrast to its rapid clearance by normal tissue. Live-cell imaging revealed that cellular ICG uptake is temperature-dependent and occurs after ICG binding to the cellular membrane, a pattern suggesting endocytic uptake as the mechanism. Cellular ICG uptake correlated inversely with the formation of tight junctions. Intracellular ICG was entrapped in the membrane traffic system, resulting in its slow turnover and prolonged retention by tumor cells. Our results suggest that tumor-specific imaging by ICG involves non-specific delivery of the dye to tissues followed by preferential tumor cellular uptake and retention. The tumor cell-preference of ICG is driven by passive tumor cell-targeting, the inherent ability of ICG to bind to cell membranes, and the high endocytic activity of tumor cells in association with the disruption of their tight junctions. [ABSTRACT FROM AUTHOR]

We have previously reported that a 28-day treatment of carcinogens evoking target cell proliferation activates G1/S checkpoint function and apoptosis, as well as induction of aberrant ubiquitin D (Ubd) expression, suggesting disruptive spindle checkpoint function, in rats. The present study aimed to determine the onset time of rat liver cells to undergo carcinogen-specific cell cycle aberration and proliferation. Animals were treated orally with a hepatocarcinogenic dose of methyleugenol or thioacetamide for 3, 7 or 28 days. For comparison, some animals were subjected to partial hepatectomy or treated with noncarcinogenic hepatotoxicants (acetaminophen, a-naphthyl isothiocyanate or promethazine). Carcinogen-specific liver cell kinetics appeared at day 28 as evident by increases of cell proliferation, p21Cip1+ cells, phosphorylated-Mdm2+ cells and cleaved caspase 3+ cells, and upregulation of DNA damage-related genes. Hepatocarcinogens also downregulated Rbl2 and upregulated Cdkn1a and Mdm2, anddecreasedUbd+ cells co-expressing phosphorylated-histoneH3 (p-Histone H3) and p-HistoneH3+ cell ratiowithin the Ki-67+ proliferating population. These results suggest that it takes 28 days to induce hepatocarcinogen-specific early withdrawal of proliferating cells fromM phase due to disruptive spindle checkpoint function as evidenced by reduction of Ubd+ cells staying atM phase. Disruption of G1/S checkpoint function reflected by downregulation of Rbl2 as well as upregulation of Mdm2 suggestive of sequestration of retinoblastoma protein is responsible for the facilitation of carcinogen-induced cell proliferation at day 28. Accumulation of DNA damage probably in association with facilitation of p53 degradation by activation of Mdm2 may be a prerequisite for aberrant p21Cip1 activation, which is responsible for apoptosis. [ABSTRACT FROM AUTHOR]

Hexachlorophene (HCP) has been shown to inducemyelin vacuolation due to intramyelinic edema of the nerve fibers in animal neural tissue. We investigated the maternal exposure effect of HCP on hippocampal neurogenesis in the offspring of pregnantmice supplementedwith 0 (control), 33 or 100 ppmHCP in diet from gestational day 6 to day 21 after delivery. On postnatal day (PND) 21, offspring as examined inmales exhibited decreased granule cell lineage populations expressing paired box 6, sex-determining region Y-box 2 and eomesodermin in the hippocampal subgranular zone (SGZ) accompanied by myelin vacuolation involving whitematter tracts of the hippocampal fimbria at = 33 ppm. However, SGZ cellular populations expressing brain lipid binding protein and doublecortin were unchanged at any dose. Transcript expression of cholinergic receptor genes, Chrna4 and Chrnb2, and glutamate receptor genes, Grm1 and Grin2d, examined at 100 ppm, decreased in the dentate gyrus. HCP exposure did not alter the number of proliferating or apoptotic cells in the SGZ, or reelin- or calcium-binding proteinexpressing γ-aminobutyric acid (GABA)ergic interneurons in the dentate hilus, on PND 21 and PND 77. All neurogenesisrelated changes observed in HCP-exposed offspring on PND 21 disappeared on PND 77, suggesting thatmaternal HCP exposure at ≥ 33 ppm reversibly decreased type 2 intermediate-stage progenitor cells in the hippocampal neurogenesis. Myelin vacuolation might be responsible for changes in neurogenesis possibly by reducing nerve conduction velocity of cholinergic inputs from the septal-hippocampal pathway to granule cell lineages and/or GABAergic interneurons, and of glutamatergic inputs to granule cell lineages. [ABSTRACT FROM AUTHOR]

We previously found that developmental hypothyroidism changed the expression of genes in the rat hippocampal dentate gyrus, a brain region where adult neurogenesis is known to occur. In the present study, we performed brain regionspecific global gene expression profiling in an adult rat hypothyroidism model to see if it reflected the developmental neurotoxicity we saw in the developmental hypothyroidism model. Starting when male rats were 5weeks old, we administered 6-propyl-2-thiouracil at a doses of 0, 0.1 and 10mgkg-1 body weight by gavage for 28days. We selected four brain regions to represent both cerebral and cerebellar tissues: hippocampal dentate gyrus, cerebral cortex, corpus callosum and cerebellar vermis. We observed significant alterations in the expression of genes related to neural development (Eph family genes and Robo3) in the cerebral cortex and hippocampal dentate gyrus and in the expression of genes related tomyelination (Plp1 and Mbp) inthe hippocampal dentate gyrus. We observed only minor changes in the expression of these genes in the corpus callosum and cerebellar vermis. We used real-time reverse-transcription polymerase chain reaction to confirmChrdl1, Hes5, Mbp, Plp1, Slit1, Robo3 and the Eph family transcript expression changes. The most significant changes in gene expression were found in the dentate gyrus. Considering that the gene expression profile of the adult dentate gyrus closely related to neurogenesis, 28-day toxicity studies looking at gene expression changes in adult hippocampal dentate gyrusmay also detect possible developmental neurotoxic effects. [ABSTRACT FROM AUTHOR]

3,3'-Iminodipropionitrile (IDPN) causes neurofilament (NF)-filled swellings in the proximal segments of many large-caliber myelinated axons. This study investigated the effect of maternal exposure to IDPN on hippocampal neurogenesis in rat offspring using pregnant rats supplemented with 0 (controls), 67 or 200 ppm IDPN in drinking water from gestational day 6 to day 21 after delivery. On postnatal day (PND) 21, female offspring subjected to analysis had decreased parvalbumin+, reelin+ and phospho-TrkB+ interneurons in the dentate hilus at 200 ppm and increased granule cell populations expressing immediate-early gene products, Arc or c-Fos, at ≥ 67 ppm. mRNA expression in the dentate gyrus examined at 200 ppm decreased with brain-derived neurotrophic factor ( Bdnf) and very low density lipoprotein receptor. Immunoreactivity for phosphorylated NF heavy polypeptide decreased in the molecular layer of the dentate gyrus and the stratum radiatum of the cornu ammonis (CA) 3, portions showing axonal projections from mossy cells and pyramidal neurons, at 200 ppm on PND 21, whereas immunoreactivity for synaptophysin was unchanged in the dentate gyrus. Observed changes all disappeared on PND 77. There were no fluctuations in the numbers of apoptotic cells, proliferating cells and subpopulations of granule cell lineage in the subgranular zone on PND 21 and PND 77. Thus, maternal IDPN exposure may reversibly affect late-stage differentiation of granule cell lineages involving neuronal plasticity as evident by immediate-early gene responses to cause BDNF downregulation resulting in a reduction in parvalbumin+ or reelin+ interneurons and suppression of axonal plasticity in the mossy cells and CA3 pyramidal neurons. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Developmental exposure to Mn caused Mn accumulation in the brain tissue and transient disruption of granule cell neurogenesis, targeting the late stage differentiation of progenitor cells in the subgranular zone of the hippocampal dentate gyrus of rats. Because neurogenesis is influenced by proinflammatory responses, this study was performed to determine whether Mn exposure causes microglial activation in the dentate hilus, a region anatomically close to the subgranular zone of the dentate gyrus. Pregnant rats were treated with dietary MnCl2 · 4H2O at 32, 160 or 800 ppm from gestational day 10 to day 21 after delivery. An immunohistochemical analysis revealed increases in Iba1+ microglia in the hilus on postnatal day 21 following exposure to MnCl2 · 4H2O in a dose-unrelated manner at 32 and at 800 ppm and an increase in CD163+ macrophage at 800 ppm in the hilus. Real-time reverse transcription-polymerase chain reaction analysis revealed increases in the mRNA levels of Il1α, Il6, Nos2 and Tnf after 800 ppm MnCl2 · 4H2O. These results suggest that activation of microglia and perivascular macrophages occurs in the hilus after developmental exposure to MnCl2 · 4H2O at 800 ppm, and probably involves the disruption of neurogenesis through the accumulation of Mn in the brain tissue. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT We previously found that exposure to glycidol at 1000 ppm in drinking water caused axonopathy in maternal rats and aberrations in late-stage hippocampal neurogenesis, targeting the process of neurite extension in offspring. To identify the profile of developmental neurotoxicity of glycidol, pregnant Sprague-Dawley rats were given drinking water containing glycidol from gestational day 6 until weaning on day 21 after delivery, and offspring at 0, 300 and 1000 ppm were subjected to region-specific global gene expression profiling. Four brain regions were selected to represent both cerebral and cerebellar tissues, i.e., the cingulate cortex, corpus callosum, hippocampal dentate gyrus and cerebellar vermis. Downregulated genes in the dentate gyrus were related to axonogenesis ( Nfasc), myelination ( Mal, Mrf and Ugt8), and cell proliferation ( Aurkb and Ndc80) at ≥ 300 ppm, and upregulated genes were related to neural development ( Frzb and Fzd6) at 1000 ppm. Upregulation was observed for genes related to myelination ( Kl, Igf2 and Igfbp2) in the corpus callosum and axonogenesis and neuritogenesis ( Efnb3, Tnc and Cd44) in the cingulate cortex, whereas downregulation was observed for genes related to synaptic transmission ( Thbs2 and Ccl2) in the cerebellar vermis; all of these changes were mostly observed at 1000 ppm. Altered gene expression of Cntn3, which functions on neurite outgrowth-promotion, was observed in all four brain regions at 1000 ppm. Gene expression profiles suggest that developmental exposure to glycidol affected plasticity of neuronal networks in the broad brain areas, and dentate gyrus neurogenesis may be the sensitive target of this type of toxicity. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Madder color (MC), a food coloring extracted from roots of Rubia tinctorum L., has been proven to exert carcinogenicity in the rat kidney and liver. Furthermore, it induces DNA adducts in the kidney, liver, and colon. MC is in fact composed of anthraquinones such as lucidin-3- O-primeveroside and alizarin. To clarify which of these might be responsible for the carcinogenicity, a rat medium-term multi-organ carcinogenesis bioassay was performed focusing on the kidney, liver, and colon. Male 6-week-old F344 rats after receiving five different carcinogens were fed a diet containing either 0.008% or 0.04% of alizarin or rubiadin, a metabolite of lucidin-3- O-primeveroside, for 23 weeks. Treatment with 0.04% rubiadin significantly increased atypical renal tubules/hyperplasias and induced renal cell adenomas and carcinomas. Renal cell tumors were also increased with 0.04% alizarin, although at lower incidence than with rubiadin. In addition, glutathione S-transferase placental form-positive liver cell foci and large intestinal dysplasias were significantly increased with 0.04% rubiadin. These results indicate that both rubiadin and alizarin can increase renal preneoplastic lesions, the potential of the latter being weaker. Rubiadin may also target the liver and large intestine, suggesting a major role in madder color-induced carcinogenicity. ( Cancer Sci 2009; 100: 2261–2267) [ABSTRACT FROM AUTHOR]

The present study investigated the involvement of signaling of phosphatase and tensin homolog deleted on chromosome 10 (PTEN)/protein kinase B (Akt) and transforming growth factor-β (TGFβ) as well as receptor tyrosine kinases in the tumor promotion processes in a two-stage hepatocarcinogenesis model using male F344 rats. The cellular localization of related molecules was examined in liver cell foci expressing glutathione S-transferase placental form (GST-P) at the early stage of tumor promotion by fenbendazole (FB), piperonyl butoxide, or thioacetamide. Distribution in the liver cell foci and neoplastic lesions positive for GST-P was also examined at the later stage of FB promotion. In contrast to the initiation-alone cases, subpopulations of GST-P-positive foci induced by promotion for 6 weeks, regardless of the promoting chemicals used, enhanced down-regulation of PTEN and up-regulation of phosphorylated (active) Akt2 and phosphorylated substrate(s) of Akt-kinase activity. Also, up-regulation of TGFβ receptor I and down-regulation of epidermal growth factor receptor (EGFR) were enhanced in the subpopulation of GST-P-positive foci in all promoted cases. A similar pattern of cellular distribution of these molecules was also observed in the neoplastic lesions at the late stage. These results suggest a crosstalk between Akt2 and TGFβ signaling that involves a mechanism requiring EGFR down-regulation during the entire tumor promotion process starting from the early stage. In particular, a shift in subcellular localization of phosphorylated substrate(s) of Akt from the cell membrane in liver cell foci to the cytoplasm in carcinomas was observed, suggesting an alteration of the function or activity of the corresponding molecule(s). ( Cancer Sci 2009; 100: 813–820) [ABSTRACT FROM AUTHOR]

To identify differentially regulated molecules related to early and late stages of tumor promotion in a rat two-stage thyroid carcinogenesis model by an antithyroid agent, sulfadimethoxine, microarray-based microdissected lesion-specific gene expression profiling was carried out. Proliferative lesions for profiling were divided into two categories: (i) focal follicular cell hyperplasias (FFCH) and adenomas (Ad) as early lesions; and (ii) carcinomas (Ca) as more advanced. In both cases, gene expression was compared with that in surrounding non-tumor follicular cells. Characteristically, upregulation of cell cycle-related genes in FFCH + Ad, downregulation of genes related to tumor suppression and transcription inhibitors of inhibitor of DNA binding (Id) family proteins in Ca, and upregulation of genes related to cell proliferation and tumor progression in common in FFCH + Ad and Ca, were detected. The immunohistochemical distributions of molecules included in the altered expression profiles were further examined. In parallel with microarray data, increased localization of ceruloplasmin, cyclin B1, and cell division cycle 2 homolog A, and decreased localization of poliovirus receptor-related 3 and Id3 were observed in all types of lesion. Although inconsistent with the microarray data, thyroglobulin immunoreactivity appeared to reduce in Ca. The results thus suggest cell cycling facilitation by induction of M-phase-promoting factor consisting of cyclin B1 and cell division cycle 2 homolog A and generation of oxidative responses as evidenced by ceruloplasmin accumulation from an early stage, as well as suppression of cell adhesion involving poliovirus receptor-related 3 and inhibition of cellular differentiation regulated by Id3. Decrease of thyroglobulin in Ca may reflect dedifferentiation with progression. ( Cancer Sci 2009; 100: 617–625) [ABSTRACT FROM AUTHOR]

The abundant in neuroepithelium area (ana) gene was originally identified as a member of the tob/ btg family of antiproliferative genes. Like the other family members, Ana inhibits growth of NIH3T3 cells when overexpressed. However, whether or not Ana is involved in tumor progression has been elusive. Here, we show that expression of ana is relatively high in the lung, the expression being restricted in type II alveolar epithelial cells. We further show that ana expression is reduced in 97% of the human lung cancer cell lines examined (61/63) and 86% of clinical samples from lung adenocarcinoma patients (36/42). Long-term observation of ana-deficient ( ana−/–) mice reveals that 8% of them develop lung tumors (5/66) by 21 months after birth, while 0% of wild-type mice (0/35) develop the same type of tumors. We also show that exogenously expressed ana gene product suppresses the levels of matrix metalloproteinase-2 ( MMP-2) and plasminogen activator inhibitor-1 ( PAI-1) expression in lung cancer cells. Taken together, we propose that ana functions as a tumor suppressor and that its product inhibits tumor progression as well by suppressing angiogenesis, invasion, and metastasis. ( Cancer Sci 2009; 100: 225–232) [ABSTRACT FROM AUTHOR]