HumanADAM33Messenger RNA Expression Profile and Post-Transcriptional Regulation

Abstract

We examined transcript expression and post-transcriptional regulation of human ADAM33, a recently identified asthma gene. A detailed messenger RNA (mRNA) expression profile was obtained using Northern, reverse transcription polymerase chain reaction, and in situ hybridization analyses. ADAM33 mRNA was expressed significantly in smooth muscle-containing organs, minimally in immune organs and hematopoietic cells, and highly in repairing duodenal granulation tissue. Expression was seen in asthmatic subepithelial fibroblasts and smooth muscle but not in respiratory epithelium. In all tissues, transcripts of approximately 5 kb predominated over those of approximately 3.5 kb by 2- to 5-fold. The effect of the 3' untranslated region (UTR) on ADAM33 protein expression and maturation was examined. The presence of the 3'UTR in untagged full-length constructs promoted prodomain removal, detected as mature approximately 100 kD protein by ADAM33-reactive antibodies; in its absence, maturation was 2- to 3-fold less in HEK293 cells. His-tagged and untagged constructs lacking the 3'UTR demonstrated that lack of maturation was not a result of tag-mediated effects. Minimal maturation of ADAM33 occurred in primary lung and MRC5 fibroblasts following adenoviral-mediated expression of ADAM33 lacking the 3'UTR. In contrast, prodomain removal was observed with plasmids and adenovirus encoding only the pro- and catalytic domains. Thus, the 3'UTR of ADAM33 and domains downstream of the catalytic domain regulate potential ADAM33 activity. Mechanisms of regulation of ADAM33, distinct from closely related ADAMs, thus include mRNA localization and processing and protein maturation.

Differential Expression of Tissue Repair Genes in the Pathogenesis of Chronic Obstructive Pulmonary Disease

“…A second gene, ADAM33, a member of a family of membrane-anchored metalloproteinases with integrin-like domains that is known to be expressed in both airway smooth muscle cells and fibroblasts (43), is linked to the pathogenesis of both asthma and COPD in both genetic linkage and association studies (44)(45)(46). However, new knowledge concerning the substrates of ADAM33 is required before the details of its role in the pathogenesis of COPD can be determined.…”

A disintegrin and metalloprotease 33 and chronic obstructive pulmonary disease pathophysiology

“…24 As its function has not been unravelled yet, we can only speculate about its role in COPD. It is conceivable that ADAM33 has a role in both remodelling and inflammation by shedding growth factors, cytokines and their receptors from the cell surface.…”

Induction of a disintegrin and metalloprotease 33 during embryonic lung development and the influence of IL-13 or maternal allergy

“…7 Unlike other members of the ADAM family, ADAM33 shows almost exclusive expression in smooth muscle-containing organs and no expression in organs or cells derived from epithelium. 1,8,9 However, a soluble form of ADAM33 (sADAM33) has been identified in bronchoalveolar lavage (BAL) fluid from subjects with asthma, where its levels are inversely correlated with lung function. 10 ADAM33/Adam33 is a member of the multifunctional ADAM family of Zn 21 -dependent metalloproteases.…”

“…In human fetal lung, ADAM33 expression has been shown in the mesenchymal progenitor 15 as well as in embryonic lung MRC-5 fibroblasts. 8,16 Using a cDNA panel of whole mouse embryos at day 8.5, day 9.5, day 12.5, and day 19, semiquantitative PCR revealed the highest expression of Adam33 mRNA at embryonic day 19. 7 Analysis of offspring (Adam33 2/2 or Adam33…”