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1.
Chem Biol Interact ; : 109767, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34863679

RESUMO

The present study investigated the role of neuroinflammation and brain oxidative stress induced by neonatal treatment with lipopolysaccharides (LPS) on the development of autism spectrum disorder (ASD)-like behaviors and disruptive hippocampal neurogenesis in rats by exploring the chemopreventive effects of alpha-glycosyl isoquercitrin (AGIQ) as an antioxidant. AGIQ was dietary administered to dams at 0.25% or 0.5% (w/w) from gestational day 18 until postnatal day (PND) 21 on weaning and then to pups until the adult stage on PND 77. The pups were intraperitoneally injected with LPS (1 mg/kg body weight) on PND 3. At PND 6, LPS alone increased Iba1+ and CD68+ cell numbers without changing the CD163+ cell number and strongly upregulated pro-inflammatory cytokine gene expression (Il1a, Il1b, Il6, Nfkb, and Tnf) in the hippocampus, and increased brain malondialdehyde levels. At PND 10, pups decreased ultrasonic vocalization (USV), suggesting the induction of pro-inflammatory responses and oxidative stress to trigger communicative deficits. By contrast, LPS alone upregulated Nfe2l2 expression at PND 6, increased Iba1+, CD68+, and CD163+ cell numbers, and upregulated Tgfb1 at PND 21, suggesting anti-inflammatory responses until the weaning period. However, LPS alone disrupted hippocampal neurogenesis at weaning and suppressed social interaction parameters and freezing rates at fear acquisition and extinction during the adolescent stage. On PND 77, neuroinflammatory responses had mostly disappeared; however, disruptive neurogenesis and fear memory deficits were sustained. AGIQ ameliorated most changes on acute pro-inflammatory responses and oxidative stress at PND 6, and the effects on USVs at PND 10 and neurogenesis and behavioral parameters throughout the adult stage. These results suggested that neonatal LPS treatment induced acute but transient neuroinflammation, triggering the progressive disruption of hippocampal neurogenesis leading to abnormal behaviors in later life. AGIQ treatment was effective for ameliorating LPS-induced progressive changes by critically suppressing initial pro-inflammatory responses and oxidative stress.

2.
J Appl Toxicol ; 2021 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-34779009

RESUMO

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.

3.
Int J Mol Sci ; 22(19)2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34639103

RESUMO

Various pathogens, such as Ebola virus, Marburg virus, Nipah virus, Hendra virus, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and SARS-CoV-2, are threatening human health worldwide. The natural hosts of these pathogens are thought to be bats. The rousette bat, a megabat, is thought to be a natural reservoir of filoviruses, including Ebola and Marburg viruses. Additionally, the rousette bat showed a transient infection in the experimental inoculation of SARS-CoV-2. In the current study, we established and characterized intestinal organoids from Leschenault's rousette, Rousettus leschenaultii. The established organoids successfully recapitulated the characteristics of intestinal epithelial structure and morphology, and the appropriate supplements necessary for long-term stable culture were identified. The organoid showed susceptibility to Pteropine orthoreovirus (PRV) but not to SARS-CoV-2 in experimental inoculation. This is the first report of the establishment of an expandable organoid culture system of the rousette bat intestinal organoid and its sensitivity to bat-associated viruses, PRV and SARS-CoV-2. This organoid is a useful tool for the elucidation of tolerance mechanisms of the emerging rousette bat-associated viruses such as Ebola and Marburg virus.


Assuntos
COVID-19/virologia , Quirópteros/virologia , Organoides/virologia , Orthoreovirus/fisiologia , Infecções por Reoviridae/virologia , SARS-CoV-2/fisiologia , Animais , COVID-19/veterinária , Técnicas de Cultura de Células , Células Cultivadas , Quirópteros/fisiologia , Humanos , Intestinos/citologia , Intestinos/virologia , Organoides/citologia , Infecções por Reoviridae/veterinária
4.
J Vet Diagn Invest ; 33(6): 1137-1141, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34672844

RESUMO

Neuroleptospirosis is a rare disease caused by pathogenic Leptospira interrogans in humans; however, it has not been fully studied in animals. A young wild raccoon dog was found convulsing in the recumbent position and died the next day. Histologic examination revealed nonsuppurative meningoencephalitis in the cerebrum, cerebellum, midbrain, and medulla oblongata. The lesions consisted of mixed infiltrates of Iba1-positive macrophages and CD3-positive T cells, with a small number of CD79α-positive B cells and myeloperoxidase-positive neutrophils. In the frontal cortex, perivascular cuffs and adjacent microglial nodules were distributed diffusely, especially in the molecular layer. Glial nodules were comprised of Iba1- and myeloperoxidase-positive activated microglia. Immunohistochemistry revealed leptospires in mononuclear cell perivascular cuffs, but not in glial nodules. Neuroleptospirosis was accompanied by Leptospira-related nonsuppurative interstitial nephritis, pulmonary edema and hemorrhage, and coronary periarteritis, as well as Toxocara tanuki in the small intestine and nonspecific foreign-body granulomas in the lungs and stomach.


Assuntos
Leptospira , Meningoencefalite , Animais , Imuno-Histoquímica , Meningoencefalite/veterinária , Cães Guaxinins , Toxocara
5.
J Comp Pathol ; 187: 2-6, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34503651

RESUMO

A 10-year-old spayed female Border Collie developed a ductal adenocarcinoma in the spleen. Clinically, the spleen was enlarged and a small liver nodule was present but there were no other abnormalities. Most of the splenic parenchyma was diffusely infiltrated by variably shaped atypical neoplastic cells that formed small clusters or larger nests, arranged as duct or duct-like structures within a fibrous matrix. There was acinar differentiation in a few portions of the tumour with a sheet-like solid growth pattern and occasional squamous metaplasia or exocrine acinus-like structures. Mitotic figures were frequent. Neoplastic cells with ductal differentiation were diffusely immunoreactive for AE1/AE3, CAM5.2 and CK7 cytokeratins but negative for CK20, while cells with acinar differentiation were immunolabelled only for AE1/AE3 cytokeratins and were also immunopositive for mucin-1 and trypsin. A few regions of tumour with ductal or acinar differentiation were immunopositive for pancreatic lipase. All neoplastic cells were negative for mucin-2, vimentin, smooth muscle actin, chromogranin A, CD31, hepatocyte paraffin 1 and thyroglobulin antigens. Because of the formation of exocrine acinus-like structures and an immunolabelling pattern consistent with exocrine pancreas tissue, an adenocarcinoma of ectopic exocrine pancreas within the spleen was diagnosed.


Assuntos
Adenocarcinoma , Doenças do Cão , Neoplasias Pancreáticas , Adenocarcinoma/veterinária , Animais , Cães , Feminino , Metaplasia/veterinária , Pâncreas Exócrino , Neoplasias Pancreáticas/veterinária
6.
Toxicology ; 462: 152958, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34547370

RESUMO

Drinking alcohol during pregnancy may cause fetal alcohol spectrum disorder. The present study investigated the effects of maternal oral ethanol (EtOH) exposure (0, 10, or 12.5 % in drinking water) from gestational day 6 until day 21 post-delivery (weaning) on postnatal hippocampal neurogenesis at weaning and in adulthood on postnatal day 77 in rat offspring. At weaning, type-3 neural progenitor cells (NPCs) were decreased in the subgranular zone (SGZ), accompanied by Chrnb2 downregulation and Grin2b upregulation in the dentate gyrus (DG). These results suggested suppression of CHRNB2-mediated cholinergic signaling in γ-aminobutyric acid (GABA)ergic interneurons in the DG hilus and increased glutamatergic signaling through the NR2B subtype of N-methyl-d-aspartate (NMDA) receptors, resulting in NPC reduction. In contrast, upregulation of Chrna7 may increase CHRNA7-mediated cholinergic signaling in immature granule cells, and upregulation of Ntrk2 may cause an increase in somatostatin-immunoreactive (+) GABAergic interneurons, suggesting a compensatory response against NPC reduction. Promotion of SGZ cell proliferation increased type-2a NPCs. Moreover, an increase in calbindin-d-29 K+ interneurons and upregulation of Reln, Drd2, Tgfb2, Il18, and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptor subunit genes might participate in this compensatory response. In adulthood, reduction of FOS+ cells and downregulation of Fos and Arc suggested suppression of granule cell synaptic plasticity, reflecting upregulation of Tnf and downregulation of Cntf, Ntrk2, and AMPA-type glutamate receptor genes. In the DG hilus, gliosis and hyper-ramified microglia, accompanying upregulation of C3, appeared at weaning, suggesting contribution to suppressed synaptic plasticity in adulthood. M1 microglia increased throughout adulthood, suggesting sustained neuroinflammation. These results indicate that maternal EtOH exposure temporarily disrupts hippocampal neurogenesis and later suppresses synaptic plasticity. Induction of neuroinflammation might initially ameliorate neurogenesis (as evident by upregulation of Tgfb2 and Il18) but later suppress synaptic plasticity (as evident by upregulation of C3 at weaning and Tnf in adulthood).

7.
Artigo em Inglês | MEDLINE | ID: mdl-34341928

RESUMO

Nonalcoholic fatty liver disease is a hepatic disorder with deposition of fat droplets and has a high risk of progression to steatosis-related hepatitis and irreversible hepatic cancer. Metronidazole (MNZ) is an antiprotozoal and antimicrobial agent widely used to treat patients infected with anaerobic bacteria and intestinal parasites; however, MNZ has also been shown to induce liver tumors in rodents. To investigate the effects of MNZ on steatosis-related early-stage hepatocarcinogenesis, male rats treated with N-nitrosodiethylamine following 2/3 hepatectomy at week 3 were received a control basal diet, high fat diet (HFD), or HFD containing 0.5% MNZ. The HFD induced obesity and steatosis in the liver, accompanied by altered expression of Pparg and Fasn, genes related to lipid metabolism. MNZ increased nuclear translocation of lipid metabolism-related transcription factor peroxisome proliferator-activated receptor gamma in hepatocytes, together with altered liver expression of lipid metabolism genes (Srebf1, Srebf2, Pnpla2). Furthermore, MNZ significantly increased the number of preneoplastic liver foci, accompanied by DNA double-strand breaks and late-stage autophagy inhibition, as reflected by increased levels of γ-H2AX, LC3, and p62. Therefore, MNZ could induce steatosis-related hepatocarcinogenesis by inducing DNA double-strand breaks and modulating autophagy in HFD-fed rats.

8.
Toxicol Lett ; 349: 69-83, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34126181

RESUMO

Exposure to sterigmatocystin (STC) raises concerns on developmental neurological disorders. The present study investigated the effects of maternal oral STC exposure on postnatal hippocampal neurogenesis of offspring in rats. Dams were exposed to STC (1.7, 5.0, and 15.0 ppm in diet) from gestational day 6 until day 21 post-delivery (weaning), and offspring were maintained without STC exposure until adulthood on postnatal day (PND) 77, in accordance with OECD chemical testing guideline Test No. 426. On PND 21, 15.0-ppm STC decreased type-3 neural progenitor cell numbers in the subgranular zone (SGZ) due to suppressed proliferation. Increased γ-H2AX-immunoreactive (+) cell numbers in the SGZ and Ercc1 upregulation and Brip1 downregulation in the dentate gyrus suggested induction of DNA double-strand breaks in SGZ cells. Upregulation of Apex1 and Ogg1 and downregulation of antioxidant genes downstream of NRF2-Keap1 signaling suggested induction of oxidative DNA damage. Increased p21WAF1/CIP1+ SGZ cell numbers and suppressed cholinergic signaling through CHRNB2-containing receptors in GABAergic interneurons suggested potential neurogenesis suppression mechanisms. Multiple mechanisms involving N-methyl-d-aspartate (NMDA) receptor-mediated glutamatergic signaling and various GABAergic interneuron subpopulations, including CHRNA7-expressing somatostatin+ interneurons activated by BDNF-TrkB signaling, may be involved in ameliorating the neurogenesis. Upregulation of Arc, Ptgs2, and genes encoding NMDA receptors and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors suggested synaptic plasticity facilitation. On PND 77, ARC+ granule cells decreased, and Nos2 was upregulated following 15.0 ppm STC exposure, suggesting oxidative stress-mediated synaptic plasticity suppression. Inverse pattern in gene expression changes in vesicular glutamate transporter isoforms, Slc17a7 and Slc17a6, from weaning might also be responsible for the synaptic plasticity suppression. The no-observed-adverse-effect level of maternal oral STC exposure for offspring neurogenesis was determined to be 5.0 ppm, translating to 0.34-0.85 mg/kg body weight/day.


Assuntos
Proliferação de Células/efeitos dos fármacos , Giro Denteado/efeitos dos fármacos , Células-Tronco Neurais/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Plasticidade Neuronal/efeitos dos fármacos , Esterigmatocistina/toxicidade , Animais , Apoptose/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla , Giro Denteado/metabolismo , Giro Denteado/patologia , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologia , Nível de Efeito Adverso não Observado , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Receptores de Neurotransmissores/genética , Receptores de Neurotransmissores/metabolismo , Desmame
9.
Cancer Biol Ther ; 22(5-6): 357-371, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34034619

RESUMO

Bladder cancer (BC), a main neoplasm of urinary tract, is usually inoperable and unresponsive to chemotherapy. As a novel experimental model for muscle-invasive BC, we previously established a culture method of dog BC organoids. In the present study, the detailed in vitro and in vivo anti-tumor effects of trametinib were investigated by using this model. In each BC organoid strain, epidermal growth factor receptor (EGFR)/ERK signaling was upregulated compared with normal bladder cells. Trametinib even at a low concentration inhibited the cell viability of BC organoids and the activation of ERK through decreasing expression of c-Myc, ELK1, SIK1, and PLA2G4A. Trametinib arrested cell cycle of BC with few apoptosis. Dual treatment of BC organoids with trametinib and YAP inhibitor, verteporfin extremely inhibited the cell viability with apoptosis induction. Moreover, trametinib induced basal to luminal differentiation of BC organoids by upregulating luminal markers and downregulating basal ones. In vivo, trametinib decreased the tumor growth of BC organoids in mice and the xenograft-derived organoids from trametinib-administered mice showed enhanced sensitivity to carboplatin due to MSH2 upregulation. Our data suggested a new strategy of trametinib-YAP inhibitor or trametinib-carboplatin combination as a promising treatment of BC.

10.
J Toxicol Sci ; 46(4): 157-165, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33814509

RESUMO

Enniatins are so-called "emerging mycotoxins" that commonly occur in milligrams per kilogram levels in grains and their derived products, as well as in fish, dried fruits, nuts, spices, cocoa, and coffee. The present study investigated the 28-day repeated oral dose toxicity of enniatin complex in CD1(ICR) mice. Enniatin B, enniatin B1, and enniatin A1 at a ratio of 4:4:1 were administered to male and female mice at doses of 0 (vehicle controls), 0.8, 4, and 20 mg/kg body weight/day. In life parameters did not change during the study period, with the exception of slight reductions in food consumption in male mice administered 4 and 20 mg/kg and in female mice administered 20 mg/kg. Body and organ weights did not change, and no alterations in hematology, blood biochemistry, or histopathology parameters were observed at the end of the administration period. Thus, we determined that the no-observed-adverse-effect level of enniatin complex was 20 mg/kg/day for both sexes under the present experimental conditions.


Assuntos
Depsipeptídeos/administração & dosagem , Depsipeptídeos/toxicidade , Micotoxinas/administração & dosagem , Micotoxinas/toxicidade , Administração Oral , Animais , Análise Química do Sangue , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Masculino , Camundongos Endogâmicos ICR , Nível de Efeito Adverso não Observado , Tamanho do Órgão , Fatores de Tempo
11.
J Vet Med Sci ; 83(6): 994-996, 2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-33896874

RESUMO

We encountered a case of cutaneous squamous cell carcinoma (SCC) in a 17-year-old female koala at a zoo. A fragile, papillary, elevated mass was found on the third digit of the right hind limb. SCC was identified histopathologically: squamous cell-like polygonal tumor cells showed a nest-like growth pattern with epidermal down growth, central keratinization and necrotic foci, and invaded dermal connective tissues. Metastatic lesions were observed in various organs, including the lung and axillary lymph node: in the lung, multiple metastatic foci similar to the primary lesion, and in the axillary lymph node, individual polygonal tumor cells infiltrated the sinusoids. Immunohistochemistry revealed that the tumor cells were positive for proliferating cell nuclear antigen, which exhibited 32-33% of labeling indices in the tumor cells. To our knowledge, this is the first report of a case of SCC in a digit of a koala.


Assuntos
Carcinoma de Células Escamosas , Phascolarctidae , Neoplasias Cutâneas , Animais , Carcinoma de Células Escamosas/veterinária , Feminino , Imuno-Histoquímica , Linfonodos , Neoplasias Cutâneas/veterinária
12.
Toxicology ; 456: 152782, 2021 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-33862172

RESUMO

Lead (Pb) exposure causes cognitive deficits in children. The present study investigated the effect of developmental exposure to Pb acetate (PbAc) on postnatal hippocampal neurogenesis. Pregnant rats were administered drinking water containing 0, 2000, or 4000 ppm PbAc from gestational day 6 until day 21 post-delivery (weaning), and offspring were maintained without PbAc exposure until adulthood on postnatal day (PND) 77. There was a dose-related accumulation of Pb in the offspring brain at weaning, while Pb was mainly excreted in adulthood. In the hippocampus, metallothionein I/II immunoreactive (+) glia were increased through adulthood as a neuroprotective response to accumulated Pb, accompanied by increased astrocyte and microglia numbers in adulthood, suggesting sustained neural damage. Gene expression changes suggested elevated oxidative stress at weaning and suppression of the antioxidant system in adulthood, as well as continued neuroinflammatory responses. At weaning, granule cell apoptosis was increased and numbers of type-3 neural progenitor cells (NPCs) were decreased. By contrast, type-2a and type-2b NPCs were increased, suggesting suppressed differentiation to type-3 NPCs. In adulthood, there were increased numbers of immature granule cells. In the hilus of the dentate gyrus, somatostatin+ interneurons were increased at weaning, while calbindin-D-29K+ interneurons were increased throughout adulthood, suggesting a strengthened interneuron regulatory system against the suppressed differentiation at weaning. In the dentate gyrus, Bdnf, Ntrk2, and Chrna7 gene expression were upregulated and numbers of hilar TrkB+ interneurons increased at weaning. These findings suggest activation of BDNF-TrkB signaling to increase somatostatin+ interneurons and promote cholinergic signaling, thus increasing later production of immature granule cells. In adulthood, Pcna and Apex1 gene expression were downregulated and Chek1 and cyclin-dependent kinase inhibitor expression were upregulated. Furthermore, there was an increase in γ-H2AX+ SGZ cells, suggesting induction of cellular senescence of SGZ cells due to Pb genotoxicity.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/biossíntese , Senescência Celular/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Compostos Organometálicos/toxicidade , Receptor trkB/biossíntese , Animais , Senescência Celular/fisiologia , Relação Dose-Resposta a Droga , Feminino , Hipocampo/crescimento & desenvolvimento , Hipocampo/metabolismo , Masculino , Neurogênese/fisiologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
13.
Nutr Res ; 85: 99-118, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33460863

RESUMO

An amorphous formula of curcumin (CUR) has shown to enable an improved bioavailability after ingestion. The aim of this study was to investigate the hypothesis that exogenously administered CUR has an advantage in ameliorating post-traumatic stress disorder at low doses. To this end, Long-Evans rats were dietary exposed to CUR at 0.1% or 0.5% from gestational day 6 to postnatal day (PND) 74 or 77. Offspring exposed to 0.1% CUR revealed facilitation of anti-anxiety-like behavior in the open field test and fear-extinction learning tested during PND 62 to 74, increases in hippocampal granule cells expressing immediate-early gene proteins and a decrease in prelimbic cortical neurons expressing phosphorylated extracellular signal-regulated kinase 1/2 after the last trial of the fear-extinction learning test on PND 74. The constitutive gene expression levels of Gria1, Gria2, Grin2d, Slc17a6, and Slc17a7 were altered in the hippocampal dentate gyrus and amygdala on PND 77. These results suggest alterations in synaptic plasticity to strengthen neural circuits in promoting the behavioral effects by 0.1%-CUR. In contrast, 0.5% CUR revealed a lack of any of the changes in behavioral tests that were observed at 0.1%; however, this dose upregulated oxidative stress and neuroinflammation-related genes in the hippocampal dentate gyrus, and increased neural stem cells and proliferation activity of the subgranular zone in the dentate gyrus. These results suggest a possible preventive use of CUR at low doses in mitigating some stress disorders; however, excessively absorbed doses may prevent behavioral changes by inducing neuroinflammation that affects hippocampal neurogenesis involving neural stem cells.


Assuntos
Ansiedade , Comportamento Animal , Encéfalo/fisiologia , Curcumina/administração & dosagem , Medo , Animais , Animais Recém-Nascidos , Condicionamento Psicológico , Curcumina/análise , Curcumina/farmacologia , Giro Denteado/fisiologia , Extinção Psicológica , Feminino , Expressão Gênica , Hipocampo/fisiologia , Masculino , Neurogênese , Neuroglia/citologia , Plasticidade Neuronal , Neurônios/metabolismo , Córtex Pré-Frontal/fisiologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Ratos Long-Evans , Sinapses/fisiologia
14.
J Appl Toxicol ; 41(7): 1021-1037, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33150595

RESUMO

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.

15.
J Toxicol Pathol ; 33(4): 247-263, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33239843

RESUMO

We previously reported that exposure to α-glycosyl isoquercitrin (AGIQ) from the fetal stage to adulthood facilitated fear extinction learning in rats. The present study investigated the specific AGIQ exposure period sufficient for inducing this behavioral effect. Rats were dietarily exposed to 0.5% AGIQ from the postweaning stage to adulthood (PW-AGIQ), the fetal stage to postweaning stage (DEV-AGIQ), or the fetal stage to adulthood (WP-AGIQ). Fear memory, anxiety-like behavior, and object recognition memory were assessed during adulthood. Fear extinction learning was exclusively facilitated in the WP-AGIQ rats. Synaptic plasticity-related genes showed a similar pattern of constitutive expression changes in the hippocampal dentate gyrus and prelimbic medial prefrontal cortex (mPFC) between the DEV-AGIQ and WP-AGIQ rats. However, WP-AGIQ rats revealed more genes constitutively upregulated in the infralimbic mPFC and amygdala than DEV-AGIQ rats, as well as FOS-immunoreactive(+) neurons constitutively increased in the infralimbic cortex. Ninety minutes after the last fear extinction trial, many synaptic plasticity-related genes (encoding Ephs/Ephrins, glutamate receptors/transporters, and immediate-early gene proteins and their regulator, extracellular signal-regulated kinase 2 [ERK2]) were upregulated in the dentate gyrus and amygdala in WP-AGIQ rats. Additionally, WP-AGIQ rats exhibited increased phosphorylated ERK1/2+ neurons in both the prelimbic and infralimbic cortices. These results suggest that AGIQ exposure from the fetal stage to adulthood is necessary for facilitating fear extinction learning. Furthermore, constitutive and learning-dependent upregulation of synaptic plasticity-related genes/molecules may be differentially involved in brain regions that regulate fear memory. Thus, new learning-related neural circuits for facilitating fear extinction can be established in the mPFC.

16.
J Appl Toxicol ; 40(11): 1467-1479, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32596862

RESUMO

We previously found downregulation of low-density lipoprotein receptor class A domain-containing protein 4 (LDLRAD4), a negative regulator of transforming growth factor (TGF)-ß 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 TGFß 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 TGFß1, 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 TGFß 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 TGFß signaling through downregulating LDLRAD4 toward carcinogenesis in the rat liver.


Assuntos
Apoptose , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Neoplasias Hepáticas/metabolismo , Fígado/metabolismo , Lesões Pré-Cancerosas/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Tetracloreto de Carbono , Transformação Celular Neoplásica/induzido quimicamente , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/patologia , Dietilnitrosamina , Modelos Animais de Doenças , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Fígado/patologia , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Metapirileno , Lesões Pré-Cancerosas/induzido quimicamente , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/patologia , Ratos Endogâmicos F344 , Transdução de Sinais , Tioacetamida , Fatores de Tempo , Fator de Crescimento Transformador beta/genética
17.
Sci Rep ; 10(1): 9393, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32523078

RESUMO

Three-dimensional (3D) organoid culture holds great promises in cancer precision medicine. However, Matrigel and stem cell-stimulating supplements are necessary for culturing 3D organoid cells. It costs a lot of money and consumes more time and effort compared with 2D cultured cells. Therefore, the establishment of cheaper and Matrigel-free organoid culture that can maintain the characteristics of a part of 3D organoids is demanded. In the previous study, we established a dog bladder cancer (BC) 3D organoid culture system by using their urine samples. Here, we successfully isolated cells named "2.5D organoid" from multiple strains of dog BC 3D organoids using 2.5 organoid media. The cell proliferation speed of 2.5D organoids was faster than parental 3D organoid cells. The expression pattern of stem cell markers was close to 3D organoids. Injection of 2.5D organoid cells into immunodeficient mice formed tumors and showed the histopathological characteristics of urothelial carcinoma similar to the injection of dog BC 3D organoids. The 2.5D organoids had a similar sensitivity profile for anti-cancer drug treatment to their parental 3D organoids. These data suggest that our established 2.5D organoid culture method might become a reasonable and useful tool instead of 3D organoids in dog BC research and therapy.


Assuntos
Organoides/patologia , Neoplasias da Bexiga Urinária/patologia , Animais , Antineoplásicos/farmacologia , Biomarcadores Tumorais/metabolismo , Técnicas de Cultura de Células/métodos , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Cães , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Masculino , Camundongos , Organoides/efeitos dos fármacos , Organoides/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Células-Tronco/patologia , Células Tumorais Cultivadas , Neoplasias da Bexiga Urinária/tratamento farmacológico
18.
J Vet Med Sci ; 82(4): 467-474, 2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-32161237

RESUMO

Dapagliflozin is a selective sodium-glucose cotransporter 2 (SGLT2) inhibitor; it reduces glucose reabsorption via the kidney and increases the glucose excretion in urine. This inhibitor functions through a unique insulin-independent mechanism, and is therefore a potential new approach for the treatment of hyperglycemia in patients with diabetes. In this study, we evaluated the effectiveness of the SGLT2 inhibitor, dapagliflozin, by using a rat model of type 1 diabetes. Type 1 diabetes was induced by a single intraperitoneal injection of 60 mg/kg streptozotocin (STZ). The STZ-induced rats showed marked hyperglycemia and other metabolic abnormalities. We clarified the hypoglycemic effect of the combination treatment of dapagliflozin with a low dose of insulin compared with dapagliflozin alone and insulin alone in 3-week and 8-week studies. Our results showed that dapagliflozin in combination with a low dose of insulin significantly lowered hyperglycemia, hypercholesterolemia, and hypertriglyceridemia. Furthermore, the antioxidant status and body weight were improved. In contrast, treatment with dapagliflozin alone did not improve the blood glucose levels, lipid profile, antioxidant status, or body weight. These findings suggested that in type 1 diabetes, dapagliflozin was effective in combination with a low dose of insulin; however, the administration of dapagliflozin alone did not achieve a significant effect.


Assuntos
Compostos Benzidrílicos/farmacologia , Diabetes Mellitus Tipo 1/tratamento farmacológico , Glucosídeos/farmacologia , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Animais , Antioxidantes/análise , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Quimioterapia Combinada , Hipercolesterolemia/tratamento farmacológico , Hiperglicemia/tratamento farmacológico , Hipertrigliceridemia/tratamento farmacológico , Masculino , Ratos Sprague-Dawley
19.
Biomaterials ; 237: 119823, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32044522

RESUMO

Non-alcoholic steatohepatitis (NASH) is associated with liver fibrosis and cirrhosis, which eventually leads to hepatocellular carcinoma. Although several animal models were developed to understand the mechanisms of NASH pathogenesis and progression, it remains obscure. A 3D organoid culture system can recapitulate organ structures and maintain gene expression profiles of original tissues. We therefore tried to generate liver organoids from different degrees [defined as mild (NASH A), moderate (NASH B) and severe (NASH C)] of methionine- and choline-deficient diet-induced NASH model mice and analyzed the difference of their architecture, cell components, organoid-forming efficacy, and gene expression profiles. Organoids from each stage of NASH model mice were successfully generated. Interestingly, epithelial-mesenchymal transition was observed in NASH C organoids. Expression of Collagen I and an activated hepatic stellite cell marker, α-sma was upregulated in the liver organoids from NASH B and C mice. The analysis of RNA sequencing revealed that several novel genes were upregulated in all NASH liver organoids. These results suggest that our generated liver organoids from different stages of NASH diseased mice might become a useful tool for in vitro studies of the molecular mechanism of NASH development and also for identifying novel biomarkers for early diagnosis of NASH disease.


Assuntos
Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Animais , Modelos Animais de Doenças , Fígado/patologia , Cirrose Hepática/patologia , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Endogâmicos C57BL , Organoides
20.
Food Chem Toxicol ; 136: 111046, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31836554

RESUMO

To investigate the developmental exposure effect of diacetoxyscirpenol (DAS) on postnatal hippocampal neurogenesis, pregnant ICR mice were provided a diet containing DAS at 0, 0.6, 2.0, or 6.0 ppm from gestational day 6 to day 21 on weaning after delivery. Offspring were maintained through postnatal day (PND) 77 without DAS exposure. On PND 21, neural stem cells (NSCs) and all subpopulations of proliferating progenitor cells were suggested to decrease in number in the subgranular zone (SGZ) at ≥ 2.0 ppm. At 6.0 ppm, increases of SGZ cells showing TUNEL+, metallothionein-I/II+, γ-H2AX+ or malondialdehyde+, and transcript downregulation of Ogg1, Parp1 and Kit without changing the level of double-stranded DNA break-related genes were observed in the dentate gyrus. This suggested induction of oxidative DNA damage of NSCs and early-stage progenitor cells, which led to their apoptosis. Cdkn2a, Rb1 and Trp53 downregulated transcripts, which suggested an increased vulnerability to DNA damage. Hilar PVALB+ GABAergic interneurons decreased and Grin2a and Chrna7 were downregulated, which suggested suppression of type-2-progenitor cell differentiation. On PND 77, hilar RELN+ interneurons increased at ≥ 2.0 ppm; at 6.0 ppm, RELN-related Itsn1 transcripts were upregulated and ARC+ granule cells decreased. Increased RELN signals may ameliorate the response to the decreases of NSCs and ARC-mediated synaptic plasticity. These results suggest that DAS reversibly disrupts hippocampal neurogenesis by inducing oxidative cellular injury and suppressed differentiation of granule cell lineages. The no-observed-adverse-effect level of DAS for offspring neurogenesis was determined to be 0.6 ppm (0.09-0.29 mg/kg body weight/day).


Assuntos
Diferenciação Celular/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Micotoxinas/toxicidade , Neurogênese/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Tricotecenos/toxicidade , Animais , Animais Lactentes , Apoptose/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Feminino , Hipocampo/patologia , Masculino , Camundongos Endogâmicos ICR , Tamanho do Órgão/efeitos dos fármacos , Gravidez
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