The pyrimidine-pyrimidone (6-4) photoproduct (64-PP) is an important photoinduced DNA lesion constituting a mutational signature for melanoma. The structural impact of 64-PP on DNA complexed with histones affects the lesion mutagenicity and repair but remains poorly understood. Here we investigate the conformational dynamics of DNA-containing 64-PP within the nucleosome core particle by atomic-resolution molecular dynamics simulations and multiscale data analysis. We demonstrate that the histone core exerts important mechanical restraints that largely decrease global DNA structural fluctuations. However, the local DNA flexibility at the damaged site is enhanced due to imperfect structural adaptation to restraints imposed by the histone core. If 64-PP faces the histone core and is therefore not directly accessible by the repair protein, the complementary strand facing the solvent is deformed and exhibits higher flexibility than the corresponding strand in a naked, undamaged DNA. This may serve as an initial recognition signal for repair. Our simulations also pinpoint the structural role of proximal residues from the truncated histone tails.
The purpose of this study was to compare, by means of in vitro cultivation technique, five marketed brands of wound covers used in the treatment of burns and other skin defects (Biobrane(®), Suprathel(®), Veloderm(®), Xe-Derma(®), and Xenoderm(®)) for their ability to stimulate the keratinocyte growth, stratification, and differentiation. In three independent experiments, human keratinocytes were grown on the tested covers in organotypic cultures by the 3T3 feeder layer technique. Vertical paraffin sections of the wound covers with keratinocytes were processed using hematoxylin-eosin staining and immunostaining for involucrin. Keratinocyte populations on the dressings were assessed for (1) number of keratinocyte strata (primary variable), (2) quantitative growth, (3) thickness of the keratinocyte layer, and (4) cell differentiation. The Xe-Derma wound cover provided the best support to keratinocyte proliferation and stratification, with the number of keratinocyte strata significantly (p < 0.05) higher in comparison to all products studied, except Xenoderm. However, in contrast to Xe-Derma, Xenoderm did not significantly differ from the other dressings. The results of this in vitro study show that the brands based on porcine dermal matrix possess the strongest effect on keratinocyte proliferation and stratification. The distinctive position of Xe-Derma may be related to its composition, where natural dermal fibers form a smooth surface, similar to the basement membrane. Furthermore, the results indicate that in vitro evaluation of effects on epithelial growth may accelerate the development of new bio-engineering-based wound covers.
- Publikační typ
- časopisecké články MeSH
Závěrečná zpráva o řešení grantu Interní grantové agentury MZ ČR
Přeruš. str. : il., tab. ; 31 cm
U rozsáhle popálených pacientů s rozsahem kožní ztráty nad 40% tělesného povrchu je základem komplexní léčby co nejrychlejší uzávěr rané plochy. Pro pokrytí co největší plochy lůžka rány musí být autoštěp před aplikací široce síťován. Pro urychlení zhojení mezer v síťovaném autoštěpu budeme krýt autotransplantát komerčně dostupnou bezbuněčnou xenodermis (Xe-Derma), na níž předtím vykultivujeme autologní či alogenní keratinocyty (aplikace buňkami do rány).; In extensively burned patients with skin loss exceeding 40 % of the total body surface area, the major step in complex therapy is the fastest possible closure of the wound. To cover the highest possible extent of the wound bed, the autograft is largely meshed prior to application. To stimulate healing of windows, the meshed autograft will be covered by commercially available xenodermis (Xe-Derma) on which autologous or allogeneic keratinocytes have been cultured. This biological cover will be applied with keratinocytes facing the wound.
- MeSH
- autologní transplantace MeSH
- biologické krytí MeSH
- epidermis MeSH
- hojení ran MeSH
- keratinocyty MeSH
- kritický stav MeSH
- kultivované buňky MeSH
- popálení MeSH
- transplantace kůže MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- transplantologie
- traumatologie
- popáleninová medicína
- NLK Publikační typ
- závěrečné zprávy o řešení grantu IGA MZ ČR
