Long wave UVA radiation (340-400 nm) causes detrimental as well as beneficial effects on human skin. Studies of human skin fibroblasts irradiated with UVA demonstrate increased expression of both antifibrotic heme oxygenase-1 (HO-1) and matrix metalloproteinase 1 (MMP-1). The use of UVAinduced MMP-1 is well-studied in treating skin fibrotic conditions such as localized scleroderma, now called morphea. However, the role that UVA-induced HO-1 plays in phototherapy of morphea has not been characterized. In the present manuscript, we have illustrated and reviewed the biological function of HO-1 and the use of UVA1 wavebands (340-400 nm) for phototherapy; the potential use of HO-1 induction in UVA therapy of morphea is also discussed.
Methylparaben is a commonly used antimicrobial in cosmetics that has been shown to have negative effects on mammalian cells. Human melanoma M624 cells were treated with 1 and 5 mM methylparaben in the presence and absence of 25 mJ/cm 2 ultraviolet B (UV-B) light. Cell proliferation assays showed that 5 mM methylparaben was toxic to M624 cells after 24 hours. Apoptotic signaling pathways were analyzed via isolation of separate cellular compartments and protein analysis via western blot. Upon 5 mM methylparaben treatment, PARP I was cleaved indicating apoptosis, which was mediated by the TNF-α receptor activated in the lipid rafts of the M624 cells. Upon 25 mJ/cm 2 UV-B radiation, PARP II was activated indicating cellular damage, cytochrome c was released from the mitochondria, and caspase-3 was expressed. Upon combinatory treatment with 5 mM methylparaben and 25 mJ/cm 2 UV-B, apoptosis was induced through mitochondrial release of cytochrome c, expression of caspase-3 and cleavage of PARP I, while methylparaben-induced TNF-α receptor activation and UV-B-induced PARP II activation was inhibited., demonstrating that antimicrobial methylparaben in cosmetics can cause damage to cells.
No abstract
DefinitionLactoferricin is a cationic peptide that is generated by the acid-pepsin hydrolysis of mammalian lactoferrin present in the secretory granules of neutrophils (polymorphonuclear leukocytes) as well as in exocrine secretions, including milk, tears, and saliva. Interestingly, substantial quantities of lactoferricin are generated in the stomach following the ingestion of lactoferrin-containing milk. Lactoferricin possesses potent antimicrobial, antiviral, immunomodulatory, and antitumor activities. In terms of anticancer activity, the best studied of the lactoferricins is bovine lactoferricin, which consists of amino acid residues 17-41 from the NH 2 -terminal region of bovine lactoferrin (Fig. 1). A disulfide bond that forms between cysteine residues located at each end of the peptide creates a looped or hairpin structure. In an aqueous environment, bovine lactoferricin assumes an amphipathic, twisted b-sheet configuration with clear positively charged and hydrophobic faces. The relatively high proportion of asymmetrically clustered basic amino acid residues (arginine and lysine) and the hydrophobic tryptophan residues that in part comprise bovine lactoferricin are believed to be important for the peptide's biological activity. CharacteristicsThe in vitro and in vivo anticancer activity of bovine lactoferricin has been attributed to the selective cytotoxic effect (either by membrane lysis or ▶ apoptosis induction) exerted by this cationic peptide on a broad range of cancer cell types, including leukemias, lymphomas, fibrosarcomas, and various carcinomas. However, studies indicate that bovine lactoferricin is also able to inhibit ▶ angiogenesis. A similar, but less potent, antiangiogenic activity has also been reported for bovine lactoferrin. Although neovascularization is normally tightly regulated by the opposing effects of proangiogenic and antiangiogenic factors, this process becomes dysregulated during tumor growth. The action of proangiogenic factors, in combination with basement membrane degradation by proteolytic enzymes, results in the proliferation, migration, and differentiation of tumor-associated endothelial cells. Neovascularization is an essential step in tumorigenesis since the new blood vessels provide oxygen and nutrients to rapidly dividing cancer cells and remove metabolic wastes from the tumor microenvironment. This allows solid tumors to grow in size as well as promoting the development of metastatic disease. Diffusible, tumorassociated growth factors that stimulate angiogenesis include ▶ vascular endothelial growth factor 165 , ▶ platelet-derived growth factor, heparinbinding epidermal growth factor-like growth factor, and basic fibroblast growth factor (also known as fibroblast growth factor 2). Bovine lactoferricin is a potent in vivo inhibitor of vascular endothelial growth factor 165 -and basic fibroblast growth factor-induced angiogenesis in the mouse Matrigel-plug assay. This finding is consistent with the observation that administration of bovine lactoferricin by subcutaneous...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.