Wound repair capability in EDS fibroblasts can be retrieved by exogenous type V collagen.

Impaired wound healing is a typical clinical hallmark of Ehlers-Danlos Syndrome (EDS). Mutated fibroblasts from EDS patients, which deposit an abnormal extracellular matrix, showed defective migration resulting in a marked delay in wound repair. The migratory capability remarkably improved in the presence of exogenous type V collagen.

N-benzyloxycarbonyl-L-proline: an in vitro and in vivo inhibitor of prolidase.

Prolidase deficiency (PD) is a recessive disorder of the connective tissue caused by mutations in the prolidase, a specific peptidase, cleaving the dipeptides with a C-terminal prolyl and hydroxyprolyl residue. PD is a complex syndrome characterized mainly by intractable skin lesions, recurrent respiratory infections and mental retardation. The relation between prolidase biological functions and the disease is still largely unknown. We studied the effect of a prolidase inhibitor, N-benzyloxycarbonyl-l-proline (Cbz-Pro), in vitro on prolidase from human fibroblasts and in vivo on murine erythrocytes prolidase. A 90% inhibition was detected incubating cellular extracts at 1:1 ratio of Gly-Pro substrate: Cbz-Pro inhibitor. Pulse experiments performed incubating human fibroblasts with 6 mM Cbz-Pro revealed that the inhibitor uptake was completed in about 1 min. The Cbz-Pro uptake was saturable and pH dependent. Long-term incubation of fibroblasts with Cbz-Pro caused mitochondria depolarization and increased cellular death as reported for long-term culture of fibroblasts from PD patients. An inhibitory effect of Cbz-Pro has also been shown in vivo. Our results demonstrated that Cbz-Pro is a potent inhibitor of prolidase in cultured fibroblasts and it can be used in vivo to better characterize the prolidase enzyme and further investigate PD physiopathology.

Hydrogen sulphide triggers VEGF-induced intracellular Ca²âº signals in human endothelial cells but not in their immature progenitors.

Hydrogen sulphide (H2S) is a newly discovered gasotransmitter that regulates multiple steps in VEGF-induced angiogenesis. An increase in intracellular Ca(2+) concentration ([Ca(2+)]i) is central to endothelial proliferation and may be triggered by both VEGF and H2S. Albeit VEGFR-2 might serve as H2S receptor, the mechanistic relationship between VEGF- and H2S-induced Ca(2+) signals in endothelial cells is unclear. The present study aimed at assessing whether and how NaHS, a widely employed H2S donor, stimulates pro-angiogenic Ca(2+) signals in Ea.hy926 cells, a suitable surrogate for mature endothelial cells, and human endothelial progenitor cells (EPCs). We found that NaHS induced a dose-dependent increase in [Ca(2+)]i in Ea.hy926 cells. NaHS-induced Ca(2+) signals in Ea.hy926 cells did not require extracellular Ca(2+) entry, while they were inhibited upon pharmacological blockade of the phospholipase C/inositol-1,4,5-trisphosphate (InsP3) signalling pathway. Moreover, the Ca(2+) response to NaHS was prevented by genistein, but not by SU5416, which selectively inhibits VEGFR-2. However, VEGF-induced Ca(2+) signals were suppressed by dl-propargylglycine (PAG), which blocks the H2S-producing enzyme, cystathionine γ-lyase. Consistent with these data, VEGF-induced proliferation and migration were inhibited by PAG in Ea.hy926 cells, albeit NaHS alone did not influence these processes. Conversely, NaHS elevated [Ca(2+)]i only in a modest fraction of circulating EPCs, whereas neither VEGF-induced Ca(2+) oscillations nor VEGF-dependent proliferation were affected by PAG. Therefore, H2S-evoked elevation in [Ca(2+)]i is essential to trigger the pro-angiogenic Ca(2+) response to VEGF in mature endothelial cells, but not in their immature progenitors.

An in situ gelling buccal spray containing platelet lysate for the treatment of oral mucositis.

Oral mucositis is an inflammatory disease of the mucosa lining oral cavity which leads to atrophy of the epithelium and to its ulceration to form chronic lesions. Many studies, both in vitro and in vivo, have disclosed the effectiveness of growth factors derived from platelets to enhance cell proliferation, differentiation, chemotaxis, angiogenesis and extracellular matrix synthesis involved in the healing of tissues. Despite potential usefulness of growth factors, animal-derived or genetically engineered ones are currently scarcely available for regenerative therapies. The aim of the present work was to study an in situ gelling formulation to be delivered by a spraying device to the oral cavity affected by mucositis. A vehicle based on Poloxamer 407 (F127) and sodium alginate (LVG) was developed. An extemporaneous loading of the vehicle with PL was achieved. The formulation was able to quickly thermogelify at 34-35°C with a viscosity at 8°C suitable for spraying; moreover it was characterized by good mucoadhesive properties. ELISA assay evidenced that at time zero the growth factor PDGF AB was compatible with the vehicle. The in vitro wound healing test showed that the formulation enhanced cell growth as PL alone even after 72 h of contact without cell apoptosis. The overall results indicate that PL loaded in the in situ gelling F127 and LVG vehicle can be profitably employed to treat buccal mucositis.

Rescue of migratory defects of Ehlers-Danlos syndrome fibroblasts in vitro by type V collagen but not insulin-like binding protein-1.

Mutations in the genes encoding for type V collagen have been found in the classical type of Ehlers-Danlos syndrome (EDS); the most common mutations lead to a non-functional COL5A1 allele. We characterized three skin fibroblast strains derived from patients affected by classical EDS caused by COL5A1 haploinsufficiency. As a typical clinical hallmark of EDS is the impaired wound healing, we analyzed the repair capability of fibroblasts in a monolayer wounding assay. The mutant fibroblast strains were unable to move into the scraped area showing then a marked delay in wound repair. In all the EDS strains, type V collagen was absent in the extracellular space, also leading to the lack of fibronectin fibrillar network and impairing the expression of alpha(2)beta(1) and alpha(5)beta(1) integrins. The abnormal integrin pattern inhibited the positive effect of insulin-like growth factor-binding protein-1 on cell migration, whereas the migratory capability remarkably improved in the presence of exogenous type V collagen.