The extracellular matrix in the nervous system is critical in embryogenesis/cell migration, in maintaining normal structure and function and in pathological processes of repair and neoplasia. Furthermore, neurodegenerative diseases such as Alzheimer's, Parkinson's, cerebrovascular disorders, together with epilepsy and multiple sclerosis, constitute a major class of devastating conditions which will become more prevalent as the demographics of the population shifts. Collagen research in the central nervous system (CNS) has been a topic where few studies have focused and most explorations to date have concentrated on the more abundant and well defined types I and III-VI. We have recently produced polyclonal antibodies which recognize a 120-kDa protein digested by bacterial collagenase; no smaller molecular weight, collagenase-resistant fragments were detected. Although the antigen was a synthetic peptide corresponding to a Collagen XIX sequence, the antibodies clearly do not recognize either type XIX collagen, the constituent chains of the 18 other collagen types, or the reported """"""""noncollagen"""""""" proteins which have short collagenous domains. Western blot analysis of tissue extracts with the new Collagen antibodies revealed that, by far, the highest expression of the protein (designated here as Collagen B) was in brain tissue, including cerebral cortex, hippocampus, striatum, olfactory bulb, cerebellum, brain stem and spinal cord. We hypothesize that the presence of Collagen B in non-meningeal regions of the brain, along with lesser amounts in other tissues, suggests a preferential association of this protein with vascular structures and a particular function in the CNS.
Our aims i n this proposal are to identify the molecule by microsequencing of the protein purified from murine brain tissue, and/or immunoscreening of cDNA libraries prepared from rat brain or human neuronal RNAs. Sequences specific for Collagen B will then be used to generate peptide or recombinant protein derived polyclonal antibodies for immunohistochemical localization of Collagen B primarily in the CNS. The highly unusual tissue representation of Collagen B presents a unique opportunity for future elucidation of its role in CNS development, and in neuropathological conditions that will become increasingly prevalent in an aging society.
| Amenta, Peter S; Hadad, Salim; Lee, Maria T et al. (2003) Loss of types XV and XIX collagen precedes basement membrane invasion in ductal carcinoma of the female breast. J Pathol 199:298-308 |
