Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 63-kDa serum protein was identified that bound somatostatin and gastrin-releasing peptide (GRP) but not bombesin. The 63-kDa protein was detected by its ability to compete with the receptor for GRP in a receptor binding assay. This interaction could be inhibited by the addition of somatostatin, producing a higher and more accurate calculated affinity for the binding of GRP to its receptor. Somatostatin did not affect the affinity of the receptor for bombesin. Specificity of the 63-kDa protein for analogs of somatostatin, GRP, and bombesin was determined by competition with 125I-GRP and 125I-somatostatin. A tripeptide motif consisting of an aryl-hydrophobic-basic amino-acid structure in residues 15-17 of GRP (Tyr-Pro-Arg) and residues 7-9 of somatostatin (Phe-Trp-Lys) was implicated in binding. This tripeptide binding motif is not present in bombesin. That residues 15-17 of GRP are highly conserved suggests that its interaction with the 63 kDa serum protein may be physiological.
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PMID:Identification of a 63-kDa serum protein that binds somatostatin and gastrin-releasing peptide but not bombesin. 810 95

Increased intraocular levels of angiogenic growth factors such as insulin-like growth factor I (IGF-I) have been demonstrated in proliferative diabetic retinopathy (PDR). It is unclear whether increased leakage of the blood retina barrier or local synthesis primarily determine intraocular levels of IGFs in man, which is of special interest regarding possible therapeutic options with somatostatin analogues in PDR. This is the first study investigating parallelly serum and vitreous levels of IGF-I/II, IGF-BP3 and the liver-derived permeability marker albumin to determine in vivo the amount of circulation-derived intraocular IGFs. A control group without retinal proliferation and patients with PDR were compared. Levels of IGF-I/II, IGF-BP3 and albumin were determined by immunological methods. Vitreous levels of albumin were 2.2-fold elevated in patients with PDR (254.1 +/- 37.2mg/dl; n = 27; p = 0.0027) compared to controls (115.7 +/- 36.2mg/dl; n =10), whereas serum levels were slightly decreased in diabetes patients (5049 +/- 196 mg/dl vs. 4330 +/- 186 mg/dl; p = 0.0283). This was comparable to an increase of IGF-I/11 and IGF-BP3 in vitreous from PDR patients (IGF-I: 2.3 +/- 1.1 ng/ml p = 0.005. IGF-II: 37.9 +/- 4.9 ng/ml; p = 0.0003. IGF-BP3: 97.9 +/- 26.9 ng/ml; p = 0.0001; n = 34) compared to controls (IGF-I: 0.7 +/- 0.1 ng/ml. IGF-II: 21.3 +/- 4.2 ng/ml. IGF-BP3: 31.3 +/- 4.9 ng/ml: n = 19). Serum levels did not differ significantly among the groups regarding IGF-I, II and IGF-BP3. Intraocular albumin and IGF-I levels calculated as percentage of the respective serum levels correlated significantly (r = 0.42; p = 0.012). This study demonstrates that influx of IGF-I, II and IGF-BP3 in PDR quantitatively parallels influx of the liver derived serum protein albumin suggesting that leakage of the blood retina barrier and serum levels of IGF primarily determine intravitreal IGF levels rather than local synthesis. Suppression of systemic IGF levels by new, highly effective somatostatin-analogues therefore provides a promising approach to prevent PDR.
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PMID:Systemic levels contribute significantly to increased intraocular IGF-I, IGF-II and IGF-BP3 [correction of IFG-BP3] in proliferative diabetic retinopathy. 1087 Nov 61

Demonstration of receptor-mediated targeting of nanoparticles to specific organs and/or cell types is an integral aim in many bionanomedicine development projects. However, engagement of targeted receptors with ligands on nanocarriers, which is the cornerstone of the active targeting concept, is challenging to study under biologically relevant conditions and thus often stays overlooked. In this work, we utilize an in-house established bioassay for in vitro targetability validation of mesoporous silica nanoparticles (MSNs), functionalized with high-affinity peptide ligands to somatostatin receptors via protective group chemistry, ensuring the correct orientation of the peptide's pharmacophore. We demonstrate that targeted nanoparticles, but not scrambled peptide-decorated counterparts, specifically engage the targeted receptors in living cells in culture media containing serum protein. The importance of being able to exclude false positives originating from the premature detachment of targeting peptides from the MSNs is highlighted.
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PMID:In vitro Targetability Validation of Peptide-Functionalized Mesoporous Silica Nanoparticles in the Presence of Serum Proteins. 3328 45