To establish a simple and reliable animal model of skin photo-damage, 20 mice were treated with 8-MOP and exposed to UVA (UVA 320-400 nm) for 24 h. After irradiation, the structure of the epidermis and dermis, collagen fibers, elastic fibers were observed by using HE staining and Weigert technique and compared with the normal controls. The acanthosis and epidermis proliferation with accompanying hyperkeratosis and parakeratosis were observed. Inflammatory infiltration was noted in the dermis. The elastic fibers became coarse, irregularly arranged and clustered, with their number increased. The collagen fibers showed obvious degeneration and some amorphous materials could also be observed. The blood vessels were irregularly dilated and vascular walls were thickened, with infiltration of inflammatory cells. It is concluded that murine photodamage model can be quickly, conveniently and reliably established by means of 8-MOP/UVA.
Dermis/pathology ; Disease Models, Animal ; Epidermis/pathology ; Methoxsalen/*pharmacology ; Photosensitizing Agents/pharmacology ; Skin/*pathology ; Skin Aging ; Ultraviolet Rays

We studied the number and morphologic alterations of ATPase-positive Langerhans cells (LCs) in guinea pig epidermal sheets and also performed electron microscopic observations on them following long-term systemic psoralen photochemotherapy (PUVA) using 8-methoxypsoralen (8-MOP) and trimethylpsoralen (TMP). We con-firmed that the LCs are sensitive to PUVA treatment. The LC depleting effects of PUVA are dose-related and the restorator1 of LCs takes place by the 4th week following cessation of PUVA. Neither psoralens alone nor UVA alone showed any effects on LCs. There were no significant differences between 8-MOP and TMP when comparing the effects of 8-MOP plus UVA and TMP plus UVA on LC numbers and morphology. It seems that a moderate dose of PUVA causes an actual decrease in the number due to cell damage. Also, it appears likely that giant LCs appear during and following PUVA treatment as a compensatory process of the remaining cells.
Animal ; Cell Count ; Female ; Guinea Pigs ; Langerhans Cells/cytology/*drug effects/radiation effects ; Methoxsalen/pharmacology ; Microscopy, Electron ; *PUVA Therapy ; Trioxsalen/pharmacology

OBJECTIVETo investigate the effects of 8-methoxypsoralen on human melanocytes [Ca(2+)]i and cytoskeleton actin organization in vitro.

METHODSHuman melanocytes were obtained from normal foreskins. Laser confocal microscope was employed to measure [Ca(2+)]i and rhodamine-conjugated phalloidin was used to visualize the cytoskeleton actin.

RESULTS8-methoxypsoralen increased [Ca(2+)]i and induced organization of actin stress fiber cytoskeleton.

CONCLUSION8-methoxypsoralen might influence the migration of melanocytes by increasing the intracellular free Ca(2+) concentration and cytoskeleton actin reorganization.

Actins ; biosynthesis ; genetics ; Calcium ; metabolism ; Cell Movement ; drug effects ; Cells, Cultured ; Cytoskeletal Proteins ; biosynthesis ; genetics ; Humans ; Melanocytes ; cytology ; drug effects ; metabolism ; Methoxsalen ; pharmacology ; Skin ; cytology

Anthrax is a zoonosis caused by Bacillus anthracis, which seriously affects human health. In recent years, a special phenomenon is found that the metabolic active of a bacterium remains after it is killed. To development of a KBMA (killed but metabolically active) Bacillus anthracis vaccine candidate strain, a plasmid pMAD and a recombinase system Cre-loxP were used to knockout the uvrAB gene of B. anthracis AP422 which lacks both of two plasmids pXO1 and pXO2. The results of PCR and RT-PCR shows that uvrAB genes were deleted from B. anthracis AP422 chromosome successfully. The constructed B. anthracis AP422deltauvrAB was inactivated by photochemical treatment (PCT) including an exposure in a long-wave-length ultraviolet (UVA) light and a treatment of 8-Methoxypsoralen (8-MOP), then the metabolic activity were detected by the method of MTS. The results showed that the killed B. anthracis AP422deltauvrAB maintained a highly metabolic activity for at least 4 hours, showing a state of KBMA. The KBMA strain of B. anthracis AP422deltauvrAB provides the prospective vaccine candidate strain for anthrax.
Anthrax ; immunology ; microbiology ; prevention & control ; Anthrax Vaccines ; genetics ; immunology ; radiation effects ; Bacillus anthracis ; genetics ; immunology ; Gene Knockout Techniques ; Methoxsalen ; pharmacology ; Ultraviolet Rays ; Vaccines, Inactivated ; genetics ; immunology

OBJECTIVETo investigate the relationships between skin photoaging and point mutations in mitochondrial DNA (mtDNA) control region for replication of dermal fibroblast.

METHODSCultured dermal fibroblasts were treated by 8-methoxypsora len /ultraviolet A (8-MOP/UVA). mtDNA was extracted by one-step-method and th e PCR products of D-loop and adjacent transcription promoter (DLP(6)) fragment of mtDNA control region for replication were detected by polymerase chain reaction-single strain conformation polymorphism and direct sequencing.

RESULTSAfter treated by 8-MOP/UVA, point mutations of 414 T-->G of DLP(6) fragment of mtDNA control region for replication largely accumulated.

CONCLUSIONAccumulation of point mutations of DLP(6) fragment of mtDNA control region for replication may be closely associated with skin photoaging.

Adult ; Binding Sites ; Cells, Cultured ; DNA Replication ; DNA, Mitochondrial ; drug effects ; radiation effects ; Dermis ; cytology ; Fibroblasts ; cytology ; drug effects ; radiation effects ; Humans ; Male ; Methoxsalen ; pharmacology ; Photosensitizing Agents ; pharmacology ; Point Mutation ; Ultraviolet Rays

Benzoates ; pharmacology ; Cells, Cultured ; Cellular Senescence ; drug effects ; radiation effects ; Gene Expression Regulation, Enzymologic ; drug effects ; radiation effects ; Humans ; Infant, Newborn ; Male ; Matrix Metalloproteinase 1 ; genetics ; Matrix Metalloproteinase 3 ; genetics ; Methoxsalen ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Retinoids ; pharmacology ; Skin ; cytology ; metabolism ; Time Factors ; Tissue Inhibitor of Metalloproteinases ; metabolism ; Ultraviolet Rays