Flt1/VEGFR1 heterozygosity causes transient embryonic edema

Vascular endothelial growth factor-A is a major player in vascular development and a potent vascular permeability factor under physiological and pathological conditions by binding to a decoy receptor Flt1 and its primary receptor Flk1. In this study, we show that Flt1 heterozygous (Flt1+/−) mouse embryos grow up to adult without life-threatening abnormalities but exhibit a transient embryonic edema around the nuchal and back regions, which is reminiscent of increased nuchal translucency in human fetuses. Vascular permeability is enhanced and an intricate infolding of the plasma membrane and huge vesicle-like structures are seen in Flt1+/− capillary endothelial cells. Flk1 tyrosine phosphorylation is elevated in Flt1+/− embryos, but Flk1 heterozygosity does not suppress embryonic edema caused by Flt1 heterozygosity. When Flt1 mutants are crossed with Aspp1−/− mice which exhibit a transient embryonic edema with delayed formation and dysfunction of lymphatic vessels, only 5.7% of Flt1+/−; Aspp1−/− mice survive, compared to expected ratio (25%). Our results demonstrate that Flt1 heterozygosity causes a transient embryonic edema and can be a risk factor for embryonic lethality in combination with other mutations causing non-lethal vascular phenotype

Guideline on the use of new anticancer drugs for the treatment of Hepatocellular Carcinoma 2010 update

The "Guideline on the Use of New Anticancer Drugs for the Treatment of Hepatocellular Carcinoma" was prepared by the Study Group on New Liver Cancer Therapies established by the "Research Project on Emergency Measures to Overcome Hepatitis" under the auspices of the Health and Labour Sciences Research Grant. The Guideline brings together data collected by the Study Group on the use and incidence of adverse events in 264 patients with advanced hepatocellular carcinoma (HCC) treated using sorafenib and in 535 patients with advanced HCC treated using miriplatin at 16 participating institutions up until 22 December 2010, as well as referring to the published studies, academic presentations, and reports from the private sector. The aim of this Guideline is to facilitate understanding and current thinking regarding the proper usage of new anticancer drugs towards actual use in therapy. In terms of the format, the Guideline presents "clinical questions" on issues pertaining to medical care, makes "recommendations" on diagnosis and treatment in response to each of these clinical questions, and provides a rationale for these recommendations in the form of "scientific statements". © 2012 The Japan Society of Hepatology

マウス ノ ショキ ハッセイ ニ オケル ハイバンホウ ケイセイ ニワ claudin 4 ト claudin 6 カラ ナル タイト ジャンクション ガ ヒツヨウ デ アル

京都大学0048新制・課程博士博士(医学)甲第13445号医博第3163号新制||医||962(附属図書館)UT51-2007-S476京都大学大学院医学研究科分子医学系専攻(主査)教授 影山 龍一郎, 教授 瀬原 淳子, 教授 渡邉 大学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDA

Flt1/VEGFR1 heterozygosity causes transient embryonic edema

Vascular endothelial growth factor-A is a major player in vascular development and a potent vascular permeability factor under physiological and pathological conditions by binding to a decoy receptor Flt1 and its primary receptor Flk1. In this study, we show that Flt1 heterozygous (Flt1(+/−)) mouse embryos grow up to adult without life-threatening abnormalities but exhibit a transient embryonic edema around the nuchal and back regions, which is reminiscent of increased nuchal translucency in human fetuses. Vascular permeability is enhanced and an intricate infolding of the plasma membrane and huge vesicle-like structures are seen in Flt1(+/−) capillary endothelial cells. Flk1 tyrosine phosphorylation is elevated in Flt1(+/−) embryos, but Flk1 heterozygosity does not suppress embryonic edema caused by Flt1 heterozygosity. When Flt1 mutants are crossed with Aspp1(−/−) mice which exhibit a transient embryonic edema with delayed formation and dysfunction of lymphatic vessels, only 5.7% of Flt1(+/−); Aspp1(−/−) mice survive, compared to expected ratio (25%). Our results demonstrate that Flt1 heterozygosity causes a transient embryonic edema and can be a risk factor for embryonic lethality in combination with other mutations causing non-lethal vascular phenotype

Claudin-2–deficient mice are defective in the leaky and cation-selective paracellular permeability properties of renal proximal tubules

Claudin-2 is highly expressed in tight junctions of mouse renal proximal tubules, which possess a leaky epithelium whose unique permeability properties underlie their high rate of NaCl reabsorption. To investigate the role of claudin-2 in paracellular NaCl transport in this nephron segment, we generated knockout mice lacking claudin-2 (Cldn2−/−). The Cldn2−/− mice displayed normal appearance, activity, growth, and behavior. Light microscopy revealed no gross histological abnormalities in the Cldn2−/− kidney. Ultrathin section and freeze-fracture replica electron microscopy revealed that, similar to those of wild types, the proximal tubules of Cldn2−/− mice were characterized by poorly developed tight junctions with one or two continuous tight junction strands. In contrast, studies in isolated, perfused S2 segments of proximal tubules showed that net transepithelial reabsorption of Na+, Cl–, and water was significantly decreased in Cldn2−/− mice and that there was an increase in paracellular shunt resistance without affecting the apical or basolateral membrane resistances. Moreover, deletion of claudin-2 caused a loss of cation (Na+) selectivity and therefore relative anion (Cl–) selectivity in the proximal tubule paracellular pathway. With free access to water and food, fractional Na+ and Cl– excretions in Cldn2−/− mice were similar to those in wild types, but both were greater in Cldn2−/− mice after i.v. administration of 2% NaCl. We conclude that claudin-2 constitutes leaky and cation (Na+)–selective paracellular channels within tight junctions of mouse proximal tubules