Akiko Oguchi

Publications (2)30.77 Total impact

• Article: Dysfunction of fibroblasts of extrarenal origin underlies renal fibrosis and renal anemia in mice.

  Nariaki Asada, Masayuki Takase, Jin Nakamura, Akiko Oguchi, Misako Asada, Norio Suzuki, Ken-ichi Yamamura, Narihito Nagoshi, Shinsuke Shibata, Tata Nageswara Rao, Hans Joerg Fehling, Atsushi Fukatsu, Naoko Minegishi, Toru Kita, Takeshi Kimura, Hideyuki Okano, Masayuki Yamamoto, Motoko Yanagita
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  ABSTRACT: In chronic kidney disease, fibroblast dysfunction causes renal fibrosis and renal anemia. Renal fibrosis is mediated by the accumulation of myofibroblasts, whereas renal anemia is mediated by the reduced production of fibroblast-derived erythropoietin, a hormone that stimulates erythropoiesis. Despite their importance in chronic kidney disease, the origin and regulatory mechanism of fibroblasts remain unclear. Here, we have demonstrated that the majority of erythropoietin-producing fibroblasts in the healthy kidney originate from myelin protein zero-Cre (P0-Cre) lineage-labeled extrarenal cells, which enter the embryonic kidney at E13.5. In the diseased kidney, P0-Cre lineage-labeled fibroblasts, but not fibroblasts derived from injured tubular epithelial cells through epithelial-mesenchymal transition, transdifferentiated into myofibroblasts and predominantly contributed to fibrosis, with concomitant loss of erythropoietin production. We further demonstrated that attenuated erythropoietin production in transdifferentiated myofibroblasts was restored by the administration of neuroprotective agents, such as dexamethasone and neurotrophins. Moreover, the in vivo administration of tamoxifen, a selective estrogen receptor modulator, restored attenuated erythropoietin production as well as fibrosis in a mouse model of kidney fibrosis. These findings reveal the pathophysiological roles of P0-Cre lineage-labeled fibroblasts in the kidney and clarify the link between renal fibrosis and renal anemia.
  The Journal of clinical investigation 09/2011; 121(10):3981-90. · 15.39 Impact Factor
• Article: Loss of the BMP antagonist USAG-1 ameliorates disease in a mouse model of the progressive hereditary kidney disease Alport syndrome.

  Mari Tanaka, Misako Asada, Atsuko Y Higashi, Jin Nakamura, Akiko Oguchi, Mayumi Tomita, Sachiko Yamada, Nariaki Asada, Masayuki Takase, Tomohiko Okuda, Hiroshi Kawachi, Aris N Economides, Elizabeth Robertson, Satoru Takahashi, Takeshi Sakurai, Roel Goldschmeding, Eri Muso, Atsushi Fukatsu, Toru Kita, Motoko Yanagita
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  ABSTRACT: The glomerular basement membrane (GBM) is a key component of the filtering unit in the kidney. Mutations involving any of the collagen IV genes (COL4A3, COL4A4, and COL4A5) affect GBM assembly and cause Alport syndrome, a progressive hereditary kidney disease with no definitive therapy. Previously, we have demonstrated that the bone morphogenetic protein (BMP) antagonist uterine sensitization-associated gene-1 (USAG-1) negatively regulates the renoprotective action of BMP-7 in a mouse model of tubular injury during acute renal failure. Here, we investigated the role of USAG-1 in renal function in Col4a3-/- mice, which model Alport syndrome. Ablation of Usag1 in Col4a3-/- mice led to substantial attenuation of disease progression, normalization of GBM ultrastructure, preservation of renal function, and extension of life span. Immunohistochemical analysis revealed that USAG-1 and BMP-7 colocalized in the macula densa in the distal tubules, lying in direct contact with glomerular mesangial cells. Furthermore, in cultured mesangial cells, BMP-7 attenuated and USAG-1 enhanced the expression of MMP-12, a protease that may contribute to GBM degradation. These data suggest that the pathogenetic role of USAG-1 in Col4a3-/- mice might involve crosstalk between kidney tubules and the glomerulus and that inhibition of USAG-1 may be a promising therapeutic approach for the treatment of Alport syndrome.
  The Journal of clinical investigation 02/2010; 120(3):768-77. · 15.39 Impact Factor