Submitted to: Cell Communication and Adhesion
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/19/2006
Publication Date: 7/1/2006
Citation: Morris, A.P., Tawil, A., Berkova, Z., Wible, L., Smith, C.W., Cunningham, S.A. 2006. Junctional adhesion molecules (JAMs) are differentially expressed in fibroblasts and co-localize with ZO-1 to adherens-like junctions. Cell Communication and Adhesion. 13:233-247. Interpretive Summary: We have been studying the effects of obesity on inflammation in mice as a model of possible complications of obesity in humans. One of the basic aspects of inflammation is wound healing. This paper deals with a very basic aspect of inflammation that will be studied in the future in models of obesity, but is analyzed in this paper at the level of basic cell biology. It deals with newly recognized molecular family that allows cells to stick to each other, a necessary process for the repair of tissue. This family is called the JAM family which stands for Junctional Adhesion Molecules. In this paper we are the first to show that JAMs participate in the attachment of fibroblasts to each other. These (fibroblasts) are the cells that produce the connective tissue that seals a wound. Their ability to stick to each other and to tissues is necessary for healing. Other investigators have shown that healing is less efficient in obese individuals, and alterations in the functions of the JAM family are of potential importance in this regard.
Technical Abstract: Junctional Adhesion Molecules (JAMs) are components and regulators of the well-characterized epithelial and endothelial tight junction. Since the molecular components of native fibroblast adherens-like junctions remain poorly described we determined JAM expression profiles in fibroblasts. We found JAM-C on human dermal, lung, and corneal primary fibroblast cultures. Within murine lines, JAM-A was found in L-cells, JAM-C in 3T3 L1 cells, and both JAM-A and JAM-C were co-expressed in NIH 3T3 fibroblasts. In primary dermal fibroblasts, JAM-C concentrated at zipper-like junctions that formed between apposing cells. Dual immunostaining showed JAM-C co-localization with the ZO-1 intracellular scaffolding molecule at cell contacts that ranged from 7 mum to over 25 mum in length. JAM-C also labeled similar zipper-like junctions detected with N-Cadherin and Cadherin-11 antibodies. We conclude that endogenous JAM-C is an integral component of the dermal fibroblast adherens-like junction, and our data extend the expression and potential function of JAMs into mesenchymal tissues.