Vascular permeability in the rat eye to endogenous albumin and immunoglobulin G (IgG) examined by immunohistochemical methods.

1983 ◽  
Vol 31 (3) ◽  
pp. 411-416 ◽  
Author(s):  
R M Pino ◽  
C L Thouron
Keyword(s):  
Horseradish Peroxidase ◽  
Vascular Permeability ◽  
Immunoglobulin G ◽  
Protein A ◽  
Bruch's Membrane ◽  
Bruch’S Membrane ◽  
Background Staining ◽  
Horseradish Peroxidase Method ◽  
High Degree ◽  
Endogenous Albumin

Vascular permeability in the rat retina and choroid was examined by localizing endogenous albumin (radius, 35 A) and immunoglobulin G (IgG; radius, 55 A) by immunohistochemistry. Three techniques were used: protein A-horseradish peroxidase, peroxidase-antiperoxidase, and avidin-horseradish peroxidase. The protein A-horseradish peroxidase method yielded the least amount of tissue background staining with a high degree of reaction product found in blood vessels. With this method albumin was identified in retinal capillaries, the choriocapillaris, larger choroidal vessels, and in the stroma of the choroid. Very low levels were found in Bruch's membrane. Reaction product due to IgG was also present intravascularly, but little reaction product was present around the large vessels of the choroid and none was identified in Bruch's membrane. Comparisons were made between these localizations and those of intravenously injected hemeprotein tracers of similar size.

scholarly journals Binding of Fab-horseradish peroxidase conjugates by charge and not by immunospecificity.

1985 ◽  
Vol 33 (1) ◽  
pp. 55-58 ◽  
Author(s):  
R M Pino
Keyword(s):  
Horseradish Peroxidase ◽  
Isoelectric Focusing ◽  
Collagen Fibers ◽  
Enzyme Digestion ◽  
Nonspecific Binding ◽  
Anionic Sites ◽  
Bruch's Membrane ◽  
Bruch’S Membrane ◽  
Type Viii ◽  
Positively Charged

The influence of horseradish peroxidase (HRP) charge on Fab-HRP conjugates was investigated. Rabbit nonimmune Fab coupled via periodate or glutaraldehyde to Sigma HRP type VI (pI greater than 10) were cationic (positively charged) as determined by analytical isoelectric focusing. These conjugates and HRP type VI alone stippled the basal laminae and collagen fibers in Bruch's membrane of the rat eye in a pattern identical to anionic (negative) sites. Binding was not present after the anionic sites were removed by enzyme digestion prior to immunolabeling or when HRP type VIII (anionic with pI 3.6) was used in an Fab-HRP conjugate or in an unbound form. These results indicate that anionic HRPs should be used in Fab-HRP preparations if a nonspecific binding to anionic sites is possible.

Use of Protein a Conjugated to Peroxidase to Localize Immunoglobulin G in SSPE Ferret Brain

1982 ◽  
Vol 40 ◽  
pp. 350-351
Author(s):  
Hannah R. Brown ◽  
Anthony F. Nostro ◽  
Halldor Thormar
Keyword(s):  
Immunoglobulin G ◽  
Human Disease ◽  
Measles Virus ◽  
Subacute Sclerosing Panencephalitis ◽  
Protein A ◽  
Inflammatory Lesions ◽  
Sspe Virus ◽  
Specific Immunoglobulin ◽  
Antibody Titers ◽  
The Brain

Subacute sclerosing panencephalitis (SSPE) is a slowly progressing disease of the CNS in children which is caused by measles virus. Ferrets immunized with measles virus prior to inoculation with the cell associated, syncytiogenic D.R. strain of SSPE virus exhibit characteristics very similar to the human disease. Measles virus nucleocapsids are present, high measles antibody titers are found in the sera and inflammatory lesions are prominent in the brains. Measles virus specific immunoglobulin G (IgG) is present in the brain,and IgG/ albumin ratios indicate that the antibodies are synthesized within the CNS.

scholarly journals FHL-1 interacts with human RPE cells through the α5β1 integrin and confers protection against oxidative stress

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rawshan Choudhury ◽  
Nadhim Bayatti ◽  
Richard Scharff ◽  
Ewa Szula ◽  
Viranga Tilakaratna ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Fate ◽  
Retinal Pigment ◽  
Factor H ◽  
Age Related Macular Degeneration ◽  
Bruch's Membrane ◽  
Bruch’S Membrane ◽  
Rpe Cells ◽  
Age Related

AbstractRetinal pigment epithelial (RPE) cells that underlie the neurosensory retina are essential for the maintenance of photoreceptor cells and hence vision. Interactions between the RPE and their basement membrane, i.e. the inner layer of Bruch’s membrane, are essential for RPE cell health and function, but the signals induced by Bruch’s membrane engagement, and their contributions to RPE cell fate determination remain poorly defined. Here, we studied the functional role of the soluble complement regulator and component of Bruch’s membrane, Factor H-like protein 1 (FHL-1). Human primary RPE cells adhered to FHL-1 in a manner that was eliminated by either mutagenesis of the integrin-binding RGD motif in FHL-1 or by using competing antibodies directed against the α5 and β1 integrin subunits. These short-term experiments reveal an immediate protein-integrin interaction that were obtained from primary RPE cells and replicated using the hTERT-RPE1 cell line. Separate, longer term experiments utilising RNAseq analysis of hTERT-RPE1 cells bound to FHL-1, showed an increased expression of the heat-shock protein genes HSPA6, CRYAB, HSPA1A and HSPA1B when compared to cells bound to fibronectin (FN) or laminin (LA). Pathway analysis implicated changes in EIF2 signalling, the unfolded protein response, and mineralocorticoid receptor signalling as putative pathways. Subsequent cell survival assays using H2O2 to induce oxidative stress-induced cell death suggest hTERT-RPE1 cells had significantly greater protection when bound to FHL-1 or LA compared to plastic or FN. These data show a non-canonical role of FHL-1 in protecting RPE cells against oxidative stress and identifies a novel interaction that has implications for ocular diseases such as age-related macular degeneration.

scholarly journals Targeting Post-Translational Modifications of the p73 Protein: A Promising Therapeutic Strategy for Tumors

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1916
Author(s):  
Ziad Omran ◽  
Mahmood H. Dalhat ◽  
Omeima Abdullah ◽  
Mohammed Kaleem ◽  
Salman Hosawi ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Protein A ◽  
P53 Gene ◽  
Cancer Therapies ◽  
Transactivation Domain ◽  
P53 Family ◽  
Post Translational Modifications ◽  
P53 Status ◽  
Apoptotic Effects ◽  
High Degree

The tumor suppressor p73 is a member of the p53 family and is expressed as different isoforms with opposing properties. The TAp73 isoforms act as tumor suppressors and have pro-apoptotic effects, whereas the ΔNp73 isoforms lack the N-terminus transactivation domain and behave as oncogenes. The TAp73 protein has a high degree of similarity with both p53 function and structure, and it induces the regulation of various genes involved in the cell cycle and apoptosis. Unlike those of the p53 gene, the mutations in the p73 gene are very rare in tumors. Cancer cells have developed several mechanisms to inhibit the activity and/or expression of p73, from the hypermethylation of its promoter to the modulation of the ratio between its pro- and anti-apoptotic isoforms. The p73 protein is also decorated by a panel of post-translational modifications, including phosphorylation, acetylation, ubiquitin proteasomal pathway modifications, and small ubiquitin-related modifier (SUMO)ylation, that regulate its transcriptional activity, subcellular localization, and stability. These modifications orchestrate the multiple anti-proliferative and pro-apoptotic functions of TAp73, thereby offering multiple promising candidates for targeted anti-cancer therapies. In this review, we summarize the current knowledge of the different pathways implicated in the regulation of TAp73 at the post-translational level. This review also highlights the growing importance of targeting the post-translational modifications of TAp73 as a promising antitumor strategy, regardless of p53 status.

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