Bj. Reinboth et al., Developmental expression of dermatan sulfate proteoglycans in the elastic bovine nuchal ligament, MATRIX BIOL, 19(2), 2000, pp. 149-162
The nuchal ligament of bovines is a useful system in which to study elastic
fibre formation since it contains up to 83% elastin and undergoes a period
of rapid elastinogenesis during the last trimester of fetal development an
d in the first four post-natal months. To identify proteoglycans (PGs) whic
h may be involved in this process we initially investigated changes in the
glycosaminoglycan (GAG) profiles during nuchal ligament development. In con
trast to the collagenous Achilles tendon, nuchal ligament exhibited: (a) el
evated hyaluronan (HA) levels in the peak period of elastin-associated micr
ofibril (fibrillin) synthesis (130-200 days) which precedes elastinogenesis
; and (b) markedly increased synthesis of a glucuronate-rich copolymeric fo
rm of dermatan sulfate (DS) in the period corresponding to elastin formatio
n (200-270 days). Analysis of DSPGs isolated from 230-day nuchal ligament s
howed that this copolymer was predominantly associated with a glycoform of
biglycan which was specifically elevated at this stage in development. This
finding was consistent with Northern blot analysis which showed that stead
y-state biglycan mRNA levels increased significantly during the elastinogen
ic period. In contrast, the mRNA levels for decorin, the only other DSPG de
tected in this tissue, declined rapidly after 140 days of fetal development
. In conclusion, the results suggest that HA may play a role in microfibril
assembly and that a specific glycoform of biglycan may be associated with
the elastinogenic phase of elastic fibre formation. (C) 2000 Published by E
lsevier Science B.V. /International Society of Matrix Biology. All rights r
eserved.