title: Maternal nutrient restriction inhibits ureteric bud branching but does not affect the duration of nephrogenesis in rats.
abstract: BACKGROUND
  Maternal nutrient restriction produces offspring with fewer nephrons. We studied whether the reduced nephron number is due to the inhibition of ureteric branching or early cessation of nephrogenesis in rats. Signaling pathways involved in kidney development were also examined.
  
  
  METHODS
  The offspring of dams given food ad libitum (control (CON)) and those subjected to 50% food restriction (nutrient restriceted (NR)) were examined.
  
  
  RESULTS
  At embryonic day 13 (E13), there was no difference between NR and CON in body weight or kidney size. Ureteric buds branched once in both NR and CON. At E14 and E15, body and kidney size were significantly reduced in NR. Ureteric bud tip numbers were also reduced to 50% of CON. On the other hand, the disappearance of nephrogenic zone and a nephron progenitor marker Cited1 was not different between CON and NR. The final glomerular number of NR was 80% of CON. Activated extracellular signal-regulated kinase (ERK), p38, PI3K, Akt, and mammallian target of rapamycin (mTOR), and protein expression of β-catenin were downregulated at E15.
  
  
  CONCLUSIONS
  Ureteric branching is inhibited and developmentally regulated signaling pathways are downregulated at an early stage by maternal nutrient restriction. These changes, not early cessation of nephrogenesis, may be a mechanism for the inhibited kidney growth and nephrogenesis.
authors: Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan.
authors: Midori
authors: M
authors: Awazu
authors: 1] Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan [2] Perinatal Center and Department of Neonatology, Yokohama Rosai Hospital, Kanagawa, Japan.
authors: Mariko
authors: M
authors: Hida
mesh_terms: D000821:Animal Feed; D000818:Animals; D017209:Apoptosis; D049628:Body Size; D001835:Body Weight; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005260:Female; D005508:Food Deprivation; D007668:Kidney / Q000196:embryology / Q000503:physiopathology; D007678:Kidney Glomerulus / Q000473:pathology; D039382:Maternal Nutritional Physiological Phenomena; D009024:Morphogenesis; D009035:Mothers; D009399:Nephrons / Q000196:embryology / Q000473:pathology*; D009929:Organ Size; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013997:Time Factors; D014513:Ureter / Q000196:embryology / Q000473:pathology*
chemical_list: D048049:Extracellular Signal-Regulated MAP Kinases