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Harboyan Syndrome: A Novel SLC4A11 Variant With Unique Genotype-Phenotype Correlation. Cornea 2022; 41:1053-1057. [PMID: 35439766 DOI: 10.1097/ico.0000000000003023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE The purpose of this study was to describe the genotypic and phenotypic characteristics of an infant with a SLC4A11 mutation associated with bilateral corneal edema, hearing loss, and hydronephrosis present since birth. METHODS This was a case report. Ophthalmic and systemic examination of the proband, histopathologic and ultrastructural characteristics of bilateral corneal discs, and molecular genetic evaluation by whole-exome sequencing are described. RESULTS A male infant was born with bilateral corneal opacities, sensorineural hearing loss, and hydronephrosis to healthy parents after an uneventful pregnancy. Penetrating keratoplasty of the left eye at age 10 months demonstrated minimal corneal edema with normal thickness Descemet membrane and cellular endothelium with intracytoplasmic vacuoles and degenerative changes in rare cells. Penetrating keratoplasty of the right eye 6 months later disclosed prominent corneal edema with a thickened posterior banded layer of Descemet membrane and severe endothelial atrophy. Whole-exome sequencing of the proband and parents' blood demonstrated a homozygous mutation in SLC4A11 gene (c.1735_1737delCTC,p.Leu579del). The combined clinical, histopathologic, and molecular genetic findings raised consideration of an unusual phenotype of Harboyan syndrome manifesting as congenital hereditary endothelial dystrophy with a prelingual rather than, as previously described, postlingual hearing loss. CONCLUSIONS We report a novel homozygous SLC4A11 variant with a previously undocumented phenotype of CHED in association with prelingual sensorineural hearing loss and hydronephrosis, thus broadening our understanding of the spectrum of genotypic and phenotypic findings of Harboyan syndrome.
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Aida-Yasuoka K, Nishimura N, Fujisawa N, Endo N, Narumiya S, Tohyama C. The role of prostaglandin E 2 receptor EP1 in 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced neonatal hydronephrosis in mice. Toxicology 2019; 415:10-17. [PMID: 30641090 DOI: 10.1016/j.tox.2019.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/08/2019] [Accepted: 01/09/2019] [Indexed: 10/27/2022]
Abstract
Prostaglandin E2 (PGE2) is a critical factor in the pathogenesis of dioxin-induced neonatal hydronephrosis. Since the PGE2 receptor has four subtypes, EP1 - EP4, this study was aimed to challenge the hypothesis that at least one of the four subtypes is responsible for the pathogenesis of dioxin-induced hydronephrosis. To this end, we used mouse pups, with a C57BL/6 J background, genetically lacking EP1, EP2, or EP3, and wild-type pups in whom EP4 was suppressed by administering ONO-AE3-208 (ONO), an EP4 antagonist, from postnatal day 1 (PND 1) to PND 13. To expose the pups to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) via lactation, the dams were administered TCDD at an oral dose of 20 μg/kg on PND 1. The pups' urine and kidneys were collected on PND 14 for urinalysis and histological examination, respectively. We found that the incidence of hydronephrosis was 80% in the EP1+/+ group, but was markedly reduced to 28.6% in the EP1-/- group despite the fact that PGE2 concentration in the urine was similarly increased in the both groups. In contrast, the incidence of hydronephrosis was 80% and 100% in the EP2+/+ and EP2-/-groups, respectively, and 88.9% and 100% in the EP3+/+ and EP3-/- groups, respectively. With regard to EP4, the incidence of hydronephrosis in vehicle (saline)-treated groups and ONO-treated was 88.9% and 100%, respectively. Therefore, we concluded that among PGE2 receptor subtypes, EP1 plays a predominant role in the onset of TCDD-induced neonatal hydronephrosis in mouse pups.
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Affiliation(s)
- Keiko Aida-Yasuoka
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Noriko Nishimura
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Nozomi Fujisawa
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Nozomi Endo
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shuh Narumiya
- Department of Drug Discovery Medicine, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, 606-8507, Japan
| | - Chiharu Tohyama
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan.
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Fujisawa N, Yoshioka W, Yanagisawa H, Tohyama C. Significance of AHR nuclear translocation sequence in 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced cPLA 2α activation and hydronephrosis. Arch Toxicol 2019; 93:1255-1264. [PMID: 30790002 DOI: 10.1007/s00204-019-02414-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 02/14/2019] [Indexed: 12/13/2022]
Abstract
The aryl hydrocarbon receptor (AHR) plays a major role in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced toxicity phenotypes. TCDD bound to AHR elicits both genomic action in which target genes are transcriptionally upregulated and nongenomic action in which cytosolic phospholipase A2α (cPLA2α) is rapidly activated. However, how either of these actions, separately or in combination, induces toxicity phenotypes is largely unknown. In this study, we used AHRnls/nls mice as a model in which AHR was mutated to lack nuclear translocation sequence (NLS), and AHRd/- mice as the corresponding control. Using this model, we studied TCDD-induced alterations in cPLA2α activation and related factors because of the pivotal roles of cPLA2α both in AHR's nongenomic action and in regulation of causative genes of TCDD-induced hydronephrosis. Dams were orally administered TCDD at a dose of 300 µg/kg body weight on postnatal day 1, and pups subsequently exposed to TCDD via milk were examined for gene expression on PND 7 and for histological changes on PND 14. The activation of the AHR genomic action and hydronephrosis onset were observed in the control group but not in the AHRnls/nls group. An ex vivo experiment using peritoneal macrophages exposed to 100 nM TCDD resulted in rapid activation of cPLA2α, an indicator of the nongenomic action, only in the control group but not in the AHRnls/nls group. These results indicated that an NLS is required for the AHR's genomic and nongenomic actions.
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Affiliation(s)
- Nozomi Fujisawa
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Wataru Yoshioka
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan. .,Department of Public Health and Environmental Medicine, The Jikei University School of Medicine, Tokyo, 105-8461, Japan.
| | - Hiroyuki Yanagisawa
- Department of Public Health and Environmental Medicine, The Jikei University School of Medicine, Tokyo, 105-8461, Japan
| | - Chiharu Tohyama
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan. .,Faculty of Medicine, University of Tsukuba, Tsukuba, 305-8575, Japan.
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Yoshioka W, Tohyama C. Mechanisms of Developmental Toxicity of Dioxins and Related Compounds. Int J Mol Sci 2019; 20:E617. [PMID: 30708991 PMCID: PMC6387164 DOI: 10.3390/ijms20030617] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 01/29/2019] [Accepted: 01/30/2019] [Indexed: 12/20/2022] Open
Abstract
Dioxins and related compounds induce morphological abnormalities in developing animals in an aryl hydrocarbon receptor (AhR)-dependent manner. Here we review the studies in which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is used as a prototypical compound to elucidate the pathogenesis of morphological abnormalities. TCDD-induced cleft palate in fetal mice involves a delay in palatogenesis and dissociation of fused palate shelves. TCDD-induced hydronephrosis, once considered to be caused by the anatomical obstruction of the ureter, is now separated into TCDD-induced obstructive and non-obstructive hydronephrosis, which develops during fetal and neonatal periods, respectively. In the latter, a prostaglandin E₂ synthesis pathway and urine concentration system are involved. TCDD-induced abnormal development of prostate involves agenesis of the ventral lobe. A suggested mechanism is that AhR activation in the urogenital sinus mesenchyme by TCDD modulates the wingless-type MMTV integration site family (WNT)/β-catenin signaling cascade to interfere with budding from urogenital sinus epithelium. TCDD exposure to zebrafish embryos induces loss of epicardium progenitor cells and heart malformation. AHR2-dependent downregulation of Sox9b expression in cardiomyocytes is a suggested underlying mechanism. TCDD-induced craniofacial malformation in zebrafish is considered to result from the AHR2-dependent reduction in SRY-box 9b (SOX9b), probably partly via the noncoding RNA slincR, resulting in the underdevelopment of chondrocytes and cartilage.
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Affiliation(s)
- Wataru Yoshioka
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan.
| | - Chiharu Tohyama
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan.
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Fujisawa N, Yoshioka W, Yanagisawa H, Tohyama C. Roles of cytosolic phospholipase A 2α in reproductive and systemic toxicities in 2,3,7,8-tetrachlorodibenzo-p-dioxin-exposed mice. Arch Toxicol 2017; 92:789-801. [PMID: 29043426 PMCID: PMC5818604 DOI: 10.1007/s00204-017-2081-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 09/25/2017] [Indexed: 12/01/2022]
Abstract
Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces a variety of toxicities upon binding of TCDD to aryl hydrocarbon receptor. Although this binding upregulates the synthesis of prostaglandins and their related lipid mediators via cytosolic phospholipase A2α (cPLA2α), toxicological significance of this signaling pathway remains elusive. Herein, we investigated the roles of cPLA2α in TCDD toxicities using cPLA2α-null mice. In a first set of experiments, pregnant mice were orally administered TCDD at a dose of 40 μg/kg on gestation day (GD) 12.5, and fetuses were collected on GD 18 for subsequent analyses. The number of live male fetuses of cPLA2α-null type was significantly less than that of wild-type in TCDD-exposed litters. TCDD-induced hydronephrosis was more severe in wild-type fetuses than in cPLA2α-null fetuses regardless of sex, and kidney expression levels of the inflammatory cytokines interleukin-1β and tumor necrosis factor-α were increased in a cPLA2α-dependent manner in TCDD-exposed fetuses. In a second set of experiments, following intraperitoneal administration of TCDD at 50 μg/kg, body weight of the male adult mice was decreased within 2 days in wild-type mice but was not changed in cPLA2α-null mice. In addition, TCDD-induced lipid accumulation in the livers of cPLA2α-null mice was at an intermediate level compared with TCDD-exposed wild-type and vehicle-control mice. In conclusion, the present results show that cPLA2α is involved in TCDD-induced body weight loss, lipid accumulation in the liver, fetal hydronephrosis, and cytokine gene expression, and that the molecular basis of TCDD toxicity differs considerably between target tissues and life stages.
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Affiliation(s)
- Nozomi Fujisawa
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Wataru Yoshioka
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan. .,Department of Public Health and Environmental Medicine, The Jikei University School of Medicine, Tokyo, 105-8461, Japan.
| | - Hiroyuki Yanagisawa
- Department of Public Health and Environmental Medicine, The Jikei University School of Medicine, Tokyo, 105-8461, Japan
| | - Chiharu Tohyama
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan. .,Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, 305-8575, Japan.
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