ヒト iPS サイボウ ユライ シキュウタイ ポドサイト ノ コウゾウ ト イデンシ ハツゲン

熊本大

Induction of nephron progenitors and glomeruli from human pluripotent stem cells

Studies of kidney regeneration using stem cells have progressed rapidly in recent years. Our group has developed a protocol to induce nephron progenitors from both mouse and human pluripotent stem cells which is based on a revised model of early stage kidney specification. The induced progenitors readily reconstitute three-dimensional nephron structures, including glomeruli and renal tubules, in vitro. We can further generate human induced pluripotent stem cells (iPSCs), in which nephrin-expressing glomerular podocytes are tagged with green fluorescent protein (GFP). The sorted GFP-positive cells retain the podocyte-specific molecular and structural features. Upon transplantation, mouse endothelial cells of the host animals are integrated into the human iPSC-derived glomeruli, and the podocytes show further maturation. Other laboratories have reported different protocols to induce nephron structures from human iPSCs in vitro. These findings will accelerate our understanding of kidney development and diseases in humans

Cell-extrinsic requirement for sulfate in regulating hippocampal neurogenesis

Sulfate is a key anion that is required for a range of physiological functions within the brain. These include sulfonation of extracellular proteoglycans to facilitate local growth factor binding and to regulate the shape of morphogen gradients during development. We have previously shown that mice lacking one allele of the sulfate transporter exhibit reduced sulfate transport into the brain, deficits in social behaviour, reduced performance in learning and memory tasks, and abnormal neurogenesis within the ventricular/subventricular zone lining the lateral ventricles. However, whether these mice have deficits in hippocampal neurogenesis was not addressed. Here, we demonstrate that adult mice have increased neurogenesis within the subgranular zone (SGZ) of the hippocampal dentate gyrus, with elevated numbers of neural progenitor cells and intermediate progenitors. In contrast, by 12 months of age there were reduced numbers of neural stem cells in the SGZ of heterozygous mice. Importantly, we did not observe any changes in proliferation when we isolated and cultured progenitors in neurosphere assays, suggestive of a cell-extrinsic requirement for sulfate in regulating hippocampal neurogenesis. Collectively, these data demonstrate a requirement for sulfate transport during postnatal brain development to ensure normal adult hippocampal neurogenesis

Human induced pluripotent stem cell-derived podocytes mature into vascularized glomeruli upon experimental transplantation

Glomerular podocytes express proteins, such as nephrin, that constitute the slit diaphragm, thereby contributing to the filtration process in the kidney. Glomerular development has been analyzed mainly in mice, whereas analysis of human kidney development has been minimal because of limited access to embryonic kidneys. We previously reported the induction of three-dimensional primordial glomeruli from human induced pluripotent stem (iPS) cells. Here, using transcription activator like effector nuclease-mediated homologous recombination, we generated human iPS cell lines that express green fluorescent protein (GFP) in the NPHS1 locus, which encodes nephrin, and we show that GFP expression facilitated accurate visualization of nephrin-positive podocyte formation in vitro. These induced human podocytes exhibited apicobasal polarity, with nephrin proteins accumulated close to the basal domain, and possessed primary processes that were connected with slit diaphragm like structures. Micro array analysis of sorted iPS cell derived podocytes identified well conserved marker gene expression previously shown in mouse and human podocytes in vivo. Furthermore, we developed a novel transplantation method using spacers that release the tension of host kidney capsules, thereby allowing the effective formation of glomeruli from human iPS cell derived nephron progenitors. The human glomeruli were vascularized with the host mouse endothelial cells, and iPS cell derived podocytes with numerous cell processes accumulated around the fenestrated endothelial cells. Therefore, the podocytes generated from iPS cells retain the podocyte-specific molecular and structural features, which will be useful for dissecting human glomerular development and diseases

The phosphatase Dullard negatively regulates BMP signalling and is essential for nephron maintenance after birth

Most kidney nephron components, including glomeruli and renal tubules, derive from the metanephric mesenchyme. The overall differentiation into each component finishes at birth, but the molecular events linking the perinatal and adult kidneys remain elusive. Dullard was cloned from Xenopus kidneys, and encodes a phosphatase that negatively regulates BMP signalling. Here we report that Dullard deletion in the murine metanephric mesenchyme leads to failure of nephron maintenance after birth, resulting in lethality before adulthood. The nephron components are lost by massive apoptosis within 3 weeks after birth, leading to formation of a large hollow with a thin-layered cortex and medulla. Phosphorylated Smad1/5/8 is upregulated in the mutant nephrons, probably through cell-autonomous inhibitory effects of Dullard on BMP signalling. Importantly, administration of the BMP receptor kinase inhibitor LDN-193189 partially rescued the defects caused by Dullard deletion. Thus, Dullard keeps BMP signalling at an appropriate level, which is required for nephron maintenance in the postnatal period

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熊本大