Alpers C E, Hudkins K L, Ferguson M, Johnson R J, Rutledge J C
Department of Pathology, University of Washington School of Medicine, Seattle, USA.
Kidney Int. 1995 Jul;48(1):146-54. doi: 10.1038/ki.1995.278.
Regulated expression of PDGF A-chain may be important in kidney development. We employed two polyclonal antisera to detect expression of PDGF A-chain in fetal and normal adult kidneys by immunohistochemistry. Specificity of the antisera was demonstrated by Western blots of fetal and adult kidneys, demonstrating monospecific bands at 10 to 15 kD, and by absorption studies with PDGF-A peptide. PDGF A-chain is uniformly expressed by visceral glomerular epithelial cells and the epithelial cells of the distal nephron, including collecting ducts and contiguous urothelium lining the renal pelvis, in both fetal and adult kidneys. Fetal kidneys also demonstrate expression of PDGF A-chain at the earliest stages of vesicle formation from the metanephric blastema; this expression is then only intermittently detectable in developing glomeruli until differentiation of visceral epithelial cells occurs. Fetal and mature arterial smooth muscle cells, and some express PDGF A-chain. In situ hybridization with a riboprobe made from PDGF A-chain cDNA showed close correlation of mRNA expression with protein immunohistochemistry. PDGF A-chain expression was also identified in epithelial elements of 5/6 Wilms' tumors studied. These are the first studies to localize PDGF A-chain expression in human kidney and suggest sites of activity for PDGF A-chain in development, neoplasia, and in the renal arterial sclerosis of aging.
血小板源性生长因子A链的调控表达在肾脏发育中可能很重要。我们使用两种多克隆抗血清，通过免疫组织化学检测胎儿和正常成年肾脏中血小板源性生长因子A链的表达。通过对胎儿和成年肾脏的蛋白质免疫印迹法（在10至15 kD处显示单特异性条带）以及用血小板源性生长因子A肽进行吸收研究，证实了抗血清的特异性。在胎儿和成年肾脏中，肾小球脏层上皮细胞以及远端肾单位的上皮细胞，包括集合管和肾盂内衬的连续尿路上皮，均均匀表达血小板源性生长因子A链。胎儿肾脏在中肾胚芽形成囊泡的最早阶段也显示出血小板源性生长因子A链的表达；在肾小球发育过程中，直到脏层上皮细胞分化之前，这种表达仅能间歇性检测到。胎儿和成熟的动脉平滑肌细胞也有一些表达血小板源性生长因子A链。用由血小板源性生长因子A链cDNA制成的核糖探针进行原位杂交显示，mRNA表达与蛋白质免疫组织化学密切相关。在研究的5/6肾母细胞瘤的上皮成分中也鉴定出了血小板源性生长因子A链的表达。这些是首次在人肾脏中定位血小板源性生长因子A链表达的研究，并提示了血小板源性生长因子A链在发育、肿瘤形成以及衰老相关的肾动脉硬化中的活性部位。
