Participation of Tom1L1 in EGF-stimulated endocytosis of EGF receptor

Although many proteins have been shown to participate in ligand-stimulated endocytosis of EGF receptor (EGFR), the adaptor protein responsible for interaction of activated EGFR with endocytic machinery remains elusive. We show here that EGF stimulates transient tyrosine phosphorylation of Tom1L1 by the Src family kinases, resulting in transient interaction of Tom1L1 with the activated EGFR bridged by Grb2 and Shc. Cytosolic Tom1L1 is recruited onto the plasma membrane and subsequently redistributes into the early endosome. Mutant forms of Tom1L1 defective in Tyr-phosphorylation or interaction with Grb2 are incapable of interaction with EGFR. These mutants behave as dominant-negative mutants to inhibit endocytosis of EGFR. RNAi-mediated knockdown of Tom1L1 inhibits endocytosis of EGFR. The C-terminal tail of Tom1L1 contains a novel clathrin-interacting motif responsible for interaction with the C-terminal region of clathrin heavy chain, which is important for exogenous Tom1L1 to rescue endocytosis of EGFR in Tom1L1 knocked-down cells. These results suggest that EGF triggers a transient Grb2/Shc-mediated association of EGFR with Tyr-phosphorylated Tom1L1 to engage the endocytic machinery for endocytosis of the ligand–receptor complex

Increased SPARC expression in primary angle closure glaucoma iris

Molecular Vision141886-189

Location Estimation in Wireless Sensor Networks Using Spring-Relaxation Technique

Accurate and low-cost autonomous self-localization is a critical requirement of various applications of a large-scale distributed wireless sensor network (WSN). Due to its massive deployment of sensors, explicit measurements based on specialized localization hardware such as the Global Positioning System (GPS) is not practical. In this paper, we propose a low-cost WSN localization solution. Our design uses received signal strength indicators for ranging, light weight distributed algorithms based on the spring-relaxation technique for location computation, and the cooperative approach to achieve certain location estimation accuracy with a low number of nodes with known locations. We provide analysis to show the suitability of the spring-relaxation technique for WSN localization with cooperative approach, and perform simulation experiments to illustrate its accuracy in localization

SPARC Deficiency Results in Improved Surgical Survival in a Novel Mouse Model of Glaucoma Filtration Surgery

Glaucoma is a disease frequently associated with elevated intraocular pressure that can be alleviated by filtration surgery. However, the post-operative subconjunctival scarring response which blocks filtration efficiency is a major hurdle to the achievement of long-term surgical success. Current application of anti-proliferatives to modulate the scarring response is not ideal as these often give rise to sight-threatening complications. SPARC (secreted protein, acidic and rich in cysteine) is a matricellular protein involved in extracellular matrix (ECM) production and organization. In this study, we investigated post-operative surgical wound survival in an experimental glaucoma filtration model in SPARC-null mice. Loss of SPARC resulted in a marked (87.5%) surgical wound survival rate compared to 0% in wild-type (WT) counterparts. The larger SPARC-null wounds implied that aqueous filtration through the subconjunctival space was more efficient in comparison to WT wounds. The pronounced increase in both surgical survival and filtration efficiency was associated with a less collagenous ECM, smaller collagen fibril diameter, and a loosely-organized subconjunctival matrix in the SPARC-null wounds. In contrast, WT wounds exhibited a densely packed collagenous ECM with no evidence of filtration capacity. Immunolocalization assays confirmed the accumulation of ECM proteins in the WT but not in the SPARC-null wounds. The observations in vivo were corroborated by complementary data performed on WT and SPARC-null conjunctival fibroblasts in vitro. These findings indicate that depletion of SPARC bestows an inherent change in post-operative ECM remodeling to favor wound maintenance. The evidence presented in this report is strongly supportive for the targeting of SPARC to increase the success of glaucoma filtration surgery

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Characterization of the biological properties of FGF-9

The fibroblast growth factor family of polypeptides currently consists of nine structurally-related members. Cloning of the mouse homologue of the latest reported member of the family, FGF-9, is described in this study. Mouse Fgf9 exhibits a high level of sequence conservation with the human, rat and Xenopus counterparts. Of note is the lack of a hydrophobic signal peptide at the N-terminus of the coding sequence. The protein, however, appeared to be secreted by producer cells since a significant quantity of the protein could be purified from the culture supernatant of transfected cells. Members of the FGF family are known to bind to cell surface tyrosine kinase receptors (FGFRs) to elicit a variety of physiological responses. These receptors themselves form a family of four structurally-related tyrosine kinases and each FGF member commonly has the ability to bind several members of the FGFR family. By using in vitro plate binding assays, FGF-9 is shown in this study to bind specifically to two FGFR members: FGFR2b and FGFR3c. To further study the potential functional role of FGF-9, its expression pattern in the mouse embryo was examined by both RNase protection and RNA in situ hybridization analyses. The transcript was detected in a variety of embryonic tissues: the germinal epithelium of the central nervous system, the mesonephric cords, the somites, the gut primordia and the developing eye and ear, suggesting that the gene may have multiple roles during development. In addition, the potential involvement of FGF-9 in mediating adult brain functions was examined by double RNA in situ hybridization analysis of the distribution of both Fgf9 and Fgfr3 transcripts in the adult mouse brain. Most apparent areas of co-localization are the olfactory bulb and cerebral cortex. The two transcripts are also shown to have distinct distribution patterns in the cerebellum.</p

In vitro analyses of the anti-fibrotic effect of SPARC silencing in human Tenon’s fibroblasts : comparisons with mitomycin C

Failure of glaucoma filtration surgery (GFS) is commonly attributed to scarring at the surgical site. The human Tenon’s fibroblasts (HTFs) are considered the major cell type contributing to the fibrotic response. We previously showed that SPARC (secreted protein, acidic, rich in cysteine) knockout mice had improved surgical success in a murine model of GFS. To understand the mechanisms of SPARC deficiency in delaying subconjunctival fibrosis, we used the gene silencing approach to reduce SPARC expression in HTFs and examined parameters important for wound repair and fibrosis. Mitomycin C-treated HTFs were used for comparison. We demonstrate that SPARC-silenced HTFs showed normal proliferation and negligible cellular necrosis but were impaired in motility and collagen gel contraction. The expression of pro-fibrotic genes including collagen I, MMP-2, MMP-9, MMP-14, IL-8, MCP-1 and TGF-β2 were also reduced. Importantly, TGF-β2 failed to induce significant collagen I and fibronectin expressions in the SPARC-silenced HTFs. Together, these data demonstrate that SPARC knockdown in HTFs modulates fibroblast functions important for wound fibrosis and is therefore a promising strategy in the development of anti-scarring therapeutics