Differential Zonal Expression and Adrenocorticotropin Regulation of Secreted Protein Acidic and Rich in Cysteine (SPARC), a Matricellular Protein, in the Midgestation Human Fetal Adrenal Gland: Implications for Adrenal Development

Context: Matricellular proteins are a group of secreted, multifunctional extracellular matrix glycoproteins that includes thrombospondins (TSPs), tenascin-C, and secreted protein acidic and rich in cysteine (SPARC). They may be implicated in the dynamic developmental processes of the human fetal adr...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:The journal of clinical endocrinology and metabolism 2006-08, Vol.91 (8), p.3208-3214
Hauptverfasser: Ishimoto, Hitoshi, Ginzinger, David G., Matsumoto, Tadashi, Hattori, Yoshihisa, Furuya, Masataka, Minegishi, Kazuhiro, Tanaka, Mamoru, Yoshimura, Yasunori, Jaffe, Robert B.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Context: Matricellular proteins are a group of secreted, multifunctional extracellular matrix glycoproteins that includes thrombospondins (TSPs), tenascin-C, and secreted protein acidic and rich in cysteine (SPARC). They may be implicated in the dynamic developmental processes of the human fetal adrenal (HFA) in which the outer, definitive zone (DZ) cells are postulated to proliferate, migrate centripetally, differentiate, and populate the inner, steroidogenic fetal zone (FZ). Objective: The objective of the study was to identify a matricellular molecule that likely plays a major role in HFA development. Design: Studies involved RNA, cryosections, and cell cultures from 14- to 23-wk HFAs and human adult adrenal RNA. Main Outcome Measures: Measures included transcripts encoding matricellular proteins, using real-time quantitative RT-PCR; SPARC localization by immunostaining; and ACTH regulation of SPARC expression and secretion by quantitative RT-PCR and Western blot. Results: SPARC HFA mRNA was 100-, 700-, and 300-fold higher than TSP-1, TSP-2, and tenascin-C mRNA, respectively. HFA SPARC mRNA was 3-fold higher than adult adrenals (P < 0.005), comparable with levels in adult brain (positive control), whereas mRNAs encoding TSP-1 and TSP-2 were lower in fetal than adult adrenals. SPARC immunoreactivity was detected exclusively in the FZ, not DZ. ACTH, a key regulator of HFA growth and function, increased SPARC mRNA (by 1.7-fold at 1 nm, 48 h, P < 0.05) in isolated FZ cells but not DZ cells. ACTH up-regulation of SPARC protein was also detected in FZ cell lysates and culture medium. Conclusions: Results suggest a possible role for SPARC in development of functional and/or structural zonation of the HFA.
ISSN:0021-972X
1945-7197
DOI:10.1210/jc.2005-2514