Proteolytic cleavage and activation of pro-macrophage-stimulating protein and upregulation of its receptor in tissue injury

Macrophage stimulating protein (MSP) exists in blood as inactive pro-MSP. Cleavage yields active MSP, the ligand for a membrane receptor (RON) that is expressed on keratinocytes as well as macrophages. Because both cells have roles in tissue injury, we looked for active MSP and expressed RON in wounds. Concentration of pro-MSP + MSP in wound exudates was in the range for optimal activity. Western blot showed that MSP comprised about half the total, in contrast to less than 10% of the total in blood plasma. The presence of MSP was attributed to an exudate pro-MSP convertase that had an inhibitor profile consistent with a trypsin-like serine protease. Exudate evoked morphologic changes in macrophages in vitro like that of MSP. Removal of this activity by an anti-MSP column shows that exudate stimulation of macrophages is due to MSP. RON was infrequently detected in normal skin. RON protein was markedly upregulated in burn wound epidermis and accessory structures, in proliferating cells or differentiated cells, or both. RON was also detected on macrophages and capillaries. Tissue injury leads to cleavage of pro-MSP to MSP, which has potential to act on keratinocytes, macrophages, and capillaries, all components of the wound healing response.

Mechanism and biological significance of constitutive expression of MGSA/GRO chemokines in malignant melanoma tumor progression

By reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry, MGSA-alpha, -beta, -gamma, and CXCR2 mRNA expression and proteins are detected in 7 out of 10 human melanoma lesions. The biological consequence of constitutive expression of the MGSA/GRO chemokine in immortalized melanocytes was tested in SCID and nude mouse models. Continuous expression of MGSA/GRO-alpha, -beta, or -gamma in immortalized melan-a mouse melanocytes results in nearly 100% tumor formation for each of the clones tested, whereas clones expressing only the neomycin resistance vector form tumors <10% of the time. Moreover, antibodies to the MGSA/GRO proteins slow or inhibit the formation of tumors in the SCID mouse model and block the angiogenic response to conditioned medium from the tumor-producing clones. Transcription of the MGSA/GRO chemokines is regulated by an enhancesome-like complex comprised of the nuclear factor-kappaB (NF-kappaB), HMG(I)Y, IUR, and Sp1 elements. In Hs294T melanoma cells the half life of the IKB protein is shortened in comparison to normal retinal epithelial cells, facilitating the endogenous nuclear localization of NF-kappaB. We propose that this endogenous nuclear NF-kappaB, working in concert with the 115-kDa IUR-binding factor, promotes constitutive expression of MGSA/GRO genes.

[Eyebrow reconstruction by a scalp island flap based on the frontal branch of the superficial temporal artery]

The author studied the course and measured the length of the frontal branch of the superficial temporal artery in 30 normal subjects. 19 eyebrows were reconstructed in 11 burned patients using the scalp island flap based on the frontal branch of the superficial temporal artery. The results were satisfactory. The reconstructed eyebrows looked natural with wooly hair of the frontal hairline. This method can be used not only in male patients but also in female or pediatric patients.

[Reduction mammaplasty using glandular pedicle]

A new technique for reduction mammaplasty with a glandular pedicle was designed based on the anatomical study of the vascular supply to the breast. The features of the procedure include using a pyramidal glandular pedicle that is reliably vascularized and definitely placed, maintaining a thin layer of parenchyme attached to the flap and the modified invert "T" closure. Clinical applications provided aesthetic and safe results of reliable nipple-areola survival, simplicity in breast mound creature and preservation of nipple sensitivity and the possibility of nursing function as well as less complications.