Collagen production by human smooth muscle cells isolated during intestinal organogenesis

Abstract

The extracellular matrix influences organogenesis by modulating cell behavior. In humans, collagen is the major matrix constituent of the adult intestinal wall and is synthesized by smooth muscle cells. The objective of the current study was to examine collagen production by fetal human intestinal smooth muscle cells isolated during intestinal morphogenesis. Techniques were developed for the isolation and culture of human fetal intestinal smooth muscle cells. The cultured cells were confirmed as muscle by immunohistochemical stains for cytoskeletal filaments and documentation of contractile behavior. In culture, these cells stained for mesenchymal and muscle cytoskeletal proteins: vimentin, actin, and desmin, and did not stain for neural or epithelial markers. The muscle cells contracted in response to acetylcholine, in contrast to human fetal dermal fibroblasts which did not contract appreciably. Collagen production was assayed by the uptake of [3H]-proline into collagenase-digestible protein. Collagen production was greatest at 11 weeks gestation, the youngest age studied. By 20 weeks gestation, collagen production had decreased to adult levels. However, when compared to another matrix-producing fetal mesenchymal cell, the dermal fibroblast, intestinal smooth muscle cells produced twice as much collagen. Collagen types were determined by polyacrylamide slab gel electrophoresis. Smooth muscle cells predominantly produced types I and III collagen alpha chains. Therefore, collagen production is a significant function of human fetal intestinal smooth muscle cells, and probably plays a major role in the development of intestinal structure. The in vitro model presented here provides a means of studying the regulation of this collagen production throughout intestinal organogenesis.

Vesicle‐associated protein‐A is differentially expressed during intestinal smooth muscle cell differentiation

“…A variety of studies indicate that SMCs are capable of responding to and modifying their microenvironment by the secretion of cytokines, growth factors, and extracellular matrix (Simon-Assman et al, 1990Burgess and Sizeland, 1990;Simo et al, 1991;Perr et al, 1992; One such transcript, identified as T2 (arrowhead), was differentially expressed in immature smooth muscle myocytes in three separate reactions composed of multiple concentrations of distinct tcRNA preparations both in the presence and absence of DNAse 1. Pauly et al, 1992;Arciniegas et al, 1992;Mitchell et al, 1993;Glukhova et al, 1993;Thyberg and HulthardhNilsson, 1994;Skehel et al, 2000;Weir et al, 2001).…”

Differential Binding of an SRF/NK-2/MEF2 Transcription Factor Complex in Normal Versus Neoplastic Smooth Muscle Tissues

“…Deletion mutations in two of the six collagen type IV subunits have been shown to result in Alport syndrome as well as diffuse leiomyomatosis (74). Collagen type IV, a critical component of basement membrane, has been postulated as important in the normal development of smooth muscle tissues (75,76). Therefore, defects in its structure may result in a higher incidence of developmental miscues resulting in smooth muscle tumor formation.…”

Smooth Muscle Expresses Bone Morphogenetic Protein (Vgr-1/BMP-6) in Human Fetal Intestine

“…The preparation and specificity of these antibodies has been previously demonstrated [10]. Since the architecture of the human intestine is established by 20 weeks' gestation [17], studies were performed on tissues from 15 to 24 weeks' gestation. Human and murine intestine were stained according to standard procedures using hematoxylin as a counterstain and vgr-1 antibodies at 2 mg/ ml [10,18].…”

“…Intestine was obtained from 11-to 24-week human abortuses as previously described [17]. The research protocol was approved by the Committee on Human Research of the University of California according to the policies of the National Institutes of Health.…”

“…The research protocol was approved by the Committee on Human Research of the University of California according to the policies of the National Institutes of Health. The cells were maintained in culture as previously described [17].…”