Many significant human birth defects originate around the time of neural tube closure or early during post-closure nervous system development. For example, failure of the neural tube to close generates anencephaly and spina bifida, faulty cell cycle progression is implicated in primary microcephaly, while defective migration of neuroblasts can lead to neuronal migration disorders such as lissen...

Reconstituted basement membranes and extracellular matrices have been demonstrated to affect, positively and dramatically, the production of milk proteins in cultured mammary epithelial cells. Here we show that both the expression and the deposition of extracellular matrix components themselves are regulated by substratum. The steady-state levels of the laminin, type IV collagen, and fibronecti...

Cell invasion through basement membranes is crucial during morphogenesis and cancer metastasis. Here, we genetically dissect this process during anchor-cell invasion into the vulval epithelium in C. elegans. We have identified the fos transcription factor ortholog fos-1 as a critical regulator of basement-membrane removal. In fos-1 mutants, the gonadal anchor cell extends cellular processes nor...

The functional role of glomerular parietal epithelial cells (PECs) remains poorly understood. To test the hypothesis that PECs form an impermeable barrier to filtered protein through the formation of tight junctions (TJ), studies were performed in normal animals and in the anti-glomerular basement membrane (GBM) model of crescentic nephritis. Electron microscopy showed well-defined TJ between P...

We show that endothelial cell (EC)-generated vascular guidance tunnels (ie, matrix spaces created during tube formation) serve as conduits for the recruitment and motility of pericytes along EC ablumenal surfaces to facilitate vessel maturation events, including vascular basement membrane matrix assembly and restriction of EC tube diameter. During quail development, pericyte recruitment along m...

The epithelial-mesenchymal interface of the intestinal mucosa obviously plays an important role in supporting the mucosal architecture. Its significance for the process of migration and differentiation of the epithelial cells remains to be resolved. It consists of a basement membrane, the anchoring zone and the subepithelial connective tissue, the origin of which is unknown. We therefore establ...

The expression level and functional activity of estrogen receptor alpha is an important determinant of breast physiology and breast cancer treatment. However, it has been difficult to identify the signals that regulate estrogen receptor because cultured mammary epithelial cells generally do not respond to estrogenic signals. Here, we use a combination of two- and three-dimensional culture syste...

Studies were performed to determine if cultured human endothelial cells synthesized basement membrane collagen. In culture, endothelial cells were attached to grossly visible membranous structures which on light microscopy were composed of ribbons of dense, amorphous material. On transmission electron microscopy, these membranous structures consisted of amorphous basement membrane, and material...

Muscle capillary basement membrane width is a sensitive marker for the presence of diabetic microangiopathy. Studies have indicated that genetic factors and alterations in glucose metabolism influence muscle capillary basement membrane width. To define the role of these factors we have measured muscle capillary basement membrane thickness in controls, insulin dependent diabetics, and individual...

The distal pigment cells of Orconectes limosus contain two layers of large electron lucent vacuoles that are separated by layers of small right-angled platelets adjacent to the crystalline cones. The crystalline cones of the dioptric apparatus of this species have evaginations into the distal pigment cell cytoplasm. In photoreceptors of Orconectes limosus and Procambarus clarkii a dark pigment ...