Extracellular matrix interactions. 1: Production of extracellular matrix with attachment and growth-sustaining functions by UWOV2 ovarian cancer cells growing in protein-free conditions

Expression of the alpha2beta1 and alpha3beta1 integrins at the surface of mesothelial cells: a potential attachment site of endometrial cells

OBJECTIVE

To localize alpha2beta1 and alpha3beta1 integrins in the cell membrane of peritoneal mesothelium in vivo and in vitro.

DESIGN

Descriptive study using confocal and two-photon laser-scanning microscopy.

SETTING

University-based laboratory.

PATIENT(S)

Women without endometriosis undergoing surgery for benign conditions.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Peritoneal biopsies (n = 9) and mesothelial monolayer cultures (n = 4) were incubated with antibodies to the alpha2 and alpha3 subunits and to the intact alpha2beta1 and alpha3beta1 integrins. Specimens were examined with laser-scanning microscopy.

RESULT(S)

The alpha2 and alpha3 subunits and the intact alpha2beta1 and alpha3beta1 integrins were identified at the base of the mesothelial cells (i.e., toward the basement membrane). There was also expression of the alpha2 and alpha3 subunits and the intact alpha2beta1 and alpha3beta1 integrins at the cell surface (i.e., toward the peritoneal cavity).

CONCLUSION(S)

The resolution of the confocal and two-photon laser-scanning microscope enabled localization of integrins in mesothelial cells. The presence of alpha2beta1 (collagen-laminin receptor) and alpha3beta1 integrins (collagen-laminin-fibronectin receptor) at the base of mesothelial cells suggests a role for these molecules in adhesion to the basement membrane. The presence of these molecules at the cell surface suggests a potential locus for cell adhesion in such processes as endometriosis and cancer metastasis.

Effects of polyelectrolyte complex (PEC) on human periodontal ligament fibroblast (HPLF) function. II. Enhancement of HPLF differentiation and aggregation on PEC by L-ascorbic acid and dexamethasone

In addition to many types of extra cellular matrix (ECM) in vivo, cells are stimulated by many types of vitamins, hormones, growth factors, etc. In this paper the effects of L-ascorbic acid 2-phosphate (Asc-2P) and dexamethasone (Dex) on proliferation and differentiation of human periodontal ligament fibroblast (HPLF) using polyelectrolyte complex (PEC) as a matrix in vitro will be discussed. The PEC was composed of chitosan as a polycation, with carboxymethyl (CPEC) or sulfated chitin (SPEC). Asc-2P (0.2 mM) inhibited the growth of HPLF on CPEC, but promoted the growth on SPEC. Moreover, the aggregation of HPLF on CPEC was inhibited by Asc-2P, but that on SPEC was induced in the presence of Asc-2P and Dex. Although Asc-2P reduced an increase in alkaline phosphatase (ALPase) activity of HPLF on CPEC as well, it induced a twofold increase in ALPase activities on SPEC and TCD. Furthermore, in the medium containing Asc-2P and 100 mM of Dex, cell growth was inhibited, but ALPase activity was promoted on both SPEC and TCD to form many aggregates on SPEC. ALPase activity increased by twofold over that of HPLF cultured in the medium containing only Asc-2P. Therefore, it is suggested that the cell functions of HPLF are controlled by the combination of PEC and additives.

The functional matrix hypothesis revisited. 4. The epigenetic antithesis and the resolving synthesis

In two interrelated articles, the current revision of the functional matrix hypothesis extends to a reconsideration of the relative roles of genomic and of epigenetic processes and mechanisms in the regulation (control, causation) of craniofacial growth and development. The dialectical method was chosen to analyze this matter, because it explicitly provides for the fuller presentation of a genomic thesis, an epigenetic antithesis, and a resolving synthesis. The later two are presented here, where the synthesis suggests that both genomic and epigenetic factors are necessary causes, that neither alone is also a sufficient cause, and that only the two, interacting together, furnish both the necessary and sufficient cause(s) of ontogenesis. This article also provides a comprehensive bibliography that introduces the several new, and still evolving, disciplines that may provide alternative viewpoints capable of resolving this continuing controversy; repetition of the present theoretical bases for the arguments on both sides of these questions seems nonproductive. In their place, it is suggested that the group of disciplines, broadly termed Complexity, would most likely amply repay deeper consideration and application in the study of ontogenesis.