Type VII collagen gene expression in human umbilical tissue and cells

Area of Science:

• Biochemistry
• Cell Biology
• Developmental Biology

Background:

• Type VII collagen is a minor collagen component of anchoring fibrils.
• It is primarily expressed by keratinocytes in epithelial tissues.
• Its presence and distribution in fetal tissues like the umbilical cord are not well-established.

Purpose of the Study:

• To investigate the localization and spatial distribution of type VII collagen gene expression in the human umbilical cord.
• To determine if non-epithelial cells in the umbilical cord express type VII collagen.

Main Methods:

• Indirect immunofluorescence using a monoclonal anti-human type VII collagen antibody.
• Culture and analysis of endothelial cells and fibroblast-like cells from Wharton's jelly.
• Northern transfer analysis and polymerase chain reaction (PCR) for gene expression analysis.

Main Results:

• Type VII collagen epitopes were detected in the epithelium surrounding Wharton's jelly and associated with umbilical cord blood vessel endothelial cells.
• Fibroblast-like cells cultured from Wharton's jelly showed prominent type VII collagen expression and high mRNA levels.
• Cultured human umbilical vein endothelial cells exhibited weak but detectable type VII collagen staining and gene expression via PCR.

Conclusions:

• Human umbilical tissue, particularly Wharton's jelly cells, is relatively enriched in type VII collagen.
• Differential spatial localization of type VII collagen was observed within the fetal umbilical cord.
• This study demonstrates that cells beyond keratinocytes, such as fibroblasts and endothelial cells, can express the type VII collagen gene.