Perlecan Delineates Stem Cell Niches in Human Foetal Hip, Knee and Elbow Cartilage Rudiments and Has Potential Roles in the Regulation of Stem Cell Differentiation

摘要

This study immunolocalized perlecan, Type I and II collagen andaggrecan in human foetal joint rudiment cartilages of the hip, kneeand elbow. Blood vessels in the stromal tissues, associated with thecartilage rudiments were also prominently stained with perlecan, entrappedred blood cells aided in their identification. Perlecan was aprominent extracellular matrix proteoglycan in the rudiment cartilages.Stem cell niches close to the margins of the cartilage rudimentswere prominently identified in the hip, knee and elbow and weredistinguishable from the aforementioned blood vessels which werelocated in the rudiment associated stromal tissues. Type I collagenwas also immunolocalized to the outer margins of the rudiment cartilageswhere perlecan positive niches were also present whereasthe remainder of the rudiment contained type II collagen. Stem cellniches similar to those observed in the present study have previouslybeen identified in the human foetal elbow.