Localization of Extracellular Proteins of the Human Trabecular Meshwork by Indirect Immunofluorescence

Extracellular matrix in the trabecular meshwork

“…Perlecan was localized to the basement membranes of the TM beams and SC inner wall cells. (Murphy et al 1987) At the light level, syndecan 1 immunostaining in the TM/SC was light or absent. Syndecan 2, 3 and 4 immunostaining was observed through the TM/SC region with syndecan 3 immunostaining being somewhat stronger in the JCT/SC region.…”

“…This includes a number of SLRPs, CSPGs, HSPGs, and other types of PGs (Table 1). (Murphy et al 1987;Tanihara et al 1995;Wirtz et al 1997;Knepper, P et al 1998;Friedman et al 2000;Friedman et al 2002;Ishibashi et al 2002;Knepper, P et al 2002;Borras 2003;Lo et al 2003;Filla et al 2004;Vittitow and Borras 2004;Zhao et al 2004;Chen et al 2005;Vittal et al 2005;Keller et al 2007b) Some specific core proteins have been localized to regions of the TM by immunohistochemistry using light or transmission electron microscopy. Perlecan was localized to the basement membranes of the TM beams and SC inner wall cells.…”

“…(Murphy et al 1987;Marshall et al 1990;Hernandez and Gong 1996;Yue 1996;Zhou et al 1998a;Brilakis et al 2001;Ueda et al 2002;Ueda and Yue 2003;Fuchshofer et al 2006) Interestingly, these components are not strictly limited to the basal lamina of the JCT but are also found dispersed throughout the JCT, perhaps indicating something novel about the origins of the JCT ECM. Laminins have a cruciform shape composed of a heterotrimer of different isoforms of α, β and γ subunits.…”

“…It is found abundantly in TM beams and the JCT region, with slightly higher levels in the basement membranes of TM beam cells, JCT cells and SC inner wall cells (Keller et al, manuscript in review). (Floyd et al 1985;Murphy et al 1987;Zhou et al 1998a;Bachmann et al 2006;Keller et al 2007a) In the JCT at the ultrastructural level, fibronectin is found in the amorphous material associated with the basement membranes and with the peripheral SD material of the elastic microfibrils. (Yue 1996;Brilakis et al 2001;Ueda et al 2002;Ueda and Yue 2003) In addition to forming a thin fibrous array that appears to encircle TM cells in culture, (Zhou et al 1998b) fibronectin also forms thick fibrous strands.…”

“…The classic interstitial fibrillar collagens, types I and III, form the standard collagen fibrils with a periodic 67-nm pattern, seen throughout the center of TM beams and JCT region. (Murphy et al 1987;Marshall et al 1991;Hernandez and Gong 1996;Yue 1996;Zhou et al 1998a;Zhou et al 1998b) They typically form evenly-spaced fibrils that serve primarily as a source of tensile strength for tissues. As mentioned above, type IV forms networks somewhat reminiscent of the hexagonal lattices in chicken wire, which coupled with other basement membrane proteins, provide a stable support for cell attachments.…”