Inhibition of Pathologic Corneal Neovascularization by Topical Application of a Novel Peptide In Vivo.

PURPOSE: To investigate the antiangiogenic effect of topical application of H-KI20, a novel 20-amino acid peptide from the hepatocyte growth factor, on 2 animal models of corneal neovascularization (NV), and its possible toxic effects on the cornea and conjunctiva. METHODS: The antiangiogenic effect of topical H-KI20 in vivo was studied on corneal NV induced by a mouse corneal micropocket assay and rat intrastromal suture model. In each model, H-KI20, scrambled control peptide H-KI20S, bevacizumab, and phosphate buffer solution (PBS) were applied topically 4 times a day. Corneal NV was examined, photographed, and analyzed. Histological analysis of the corneas was performed. Tear film breakup time and gross and histological examinations were used to study the possible toxicity of topical H-KI20. RESULTS: Topical application of H-KI20 significantly inhibited corneal NV induced by vascular endothelial growth factor (VEGF), and intrastromal suture (P < 0.01 vs. the PBS group), and the area of corneal NV was suppressed by 80.3% and 83.6%, respectively (PBS group as 100%). No significant difference was found between 1.0 mg/mL H-KI20 and 10 mg/mL bevacizumab (P > 0.05). Both hematoxylin and eosin and CD34 staining revealed fewer new blood vessels in the H-KI20 and bevacizumab groups. Tear film breakup time and histological examinations showed that H-KI20 had no obvious toxic effects on the cornea and conjunctiva in vivo. CONCLUSIONS: The novel peptide H-KI20 is an effective and safe inhibitor of corneal NV. It may provide a promising alternative for ocular topical antiangiogenic therapy.

Total synthesis of biotinylated N domain of human hepatocyte growth factor.

Hepatocyte growth factor/scatter factor (HGF/SF) is the high affinity ligand of MET tyrosine kinase receptor. We report here the total synthesis of a biotinylated analogue of human HGF/SF N domain. Functionally, N domain is part of the HGF/SF high affinity binding site for MET and also the main HGF/SF binding site for heparin. The 97 Aa linear chain featuring a C-terminal biotin group was assembled in high yield using an N-to-C one-pot three segments assembly strategy relying on a sequential Native Chemical Ligation (NCL)/bis(2-sulfanylethyl)amido (SEA) native peptide ligation process. The folded protein displayed the native disulfide bond pattern and showed the ability to bind heparin.

Papel de la caveolina-1 en la regeneración hepática tras hepatectomía parcial. Mecanismos de señalización y función en la regulación de la proliferación hepática / Role of caveolin 1 on liver regeneration after partial hepatectomy. Mechanisms of signalling and effect on the regulation of hepatocyte proliferation

Las caveolas participan en múltiples procesos celulares tales como el transportevesicular, homeostasis del colesterol, regulación de la señalización intracelular,por integrinas y proliferación celular. Sin embargo, su función en el hígado no estábien establecida. La expresión de caveolina 1 (Cav), la proteína más abundante enlas caveolas, está bien descrita en el hígado y en varias líneas de hepatocitos y enhígado cirrótico humano y en carcinoma hepatocelular. Sin embargo, el papel deCav-1 en la fisiopatología hepática es controvertido, ya que se ha propuesto un papel crítico en el proceso de regeneración tras hepatectomía parcial (HP). Contrariamentea esta observación, nuestros datos sugieren que Cav-1 aumenta en elhígado regenerante, con una re-distribución de la proteína desde las caveolas haciadominios no caveolares. Además, la Cav-1 localizada en estas fracciones está fosforiladaen la tirosina 14. A pesar de ello, el gen de la Cav-1 es dispensable parala regeneración hepática tras HP, tal como se deduce de animales que carecen deeste gen. En conjunto, estos datos muestran un papel dinámico de la Cav-1 en laproliferación hepática tras HP y en líneas hepáticas en cultivo, pero con mínimasimplicaciones en el proceso regenerativo

Although caveolae participate in many cellular processes such as vesicular transport,cholesterol homeostasis, regulation of signal transduction, integrin signalingand cell growth, their role in liver remains elusive. Expression of caveolin 1 (Cav),the most abundant protein of caveolae, has been reported in liver and in differenthepatocyte cell lines, in human cirrhotic liver and in hepatocellular carcinomas.However, the role of Cav-1 in liver pathophysiology remains controversial and acritical role in regeneration after partial hepatectomy (PH) has been reported.Opposite to this observation, our data support the view that Cav-1 increases inliver after PH with a redistribution of the protein from the caveolae enricheddomain to the noncaveolar fraction. Moreover, the Cav-1 located in the noncaveolarfraction is phosphorylated in tyrosine 14 (Tyr14). Even though, the Cav-1 geneis dispensable for liver regeneration after PH as deduced from data obtained withcommercially available animals lacking this gene. Taken together these resultssupport a dynamic role for Cav-1 in liver proliferation both in vivo after PH, andin vitro in cultured hepatic cell lines, but with minimal implications in the liverregeneration process