A Novel Form of Neuregulin 1 Type III Caused by N-Terminal Processing.

Nrg1 (Neuregulin 1) type III, a susceptible gene of schizophrenia, exhibits a critical role in the central nervous system and is essential at each stage of Schwann's cell development. Nrg1 type III comprises double-pass transmembrane domains, with the N-terminal and C-terminal localizing inside the cells. The N-terminal transmembrane helix partially overlaps with the cysteine-rich domain (CRD). In this study, Nrg1 type III constructs with different tags were transformed into cultured cells to verify whether CRD destroyed the transmembrane helix formation. We took advantage of immunofluorescent and immunoprecipitation assays on whole cells and analyzed the N-terminal distribution. Astonishingly, we found that a novel form of Nrg1 type III, about 10% of Nrg1 type III, omitted the N-terminal transmembrane helix, with the N-terminal positioning outside the membrane. The results indicated that the novel single-pass transmembrane status was a minor form of Nrg1 type III caused by N-terminal processing, while the major form was a double-pass transmembrane status.

[Repair of excised burn wound with microskin grafting covered by autologous burn eschar].

OBJECTIVE: To explore the feasibility of autologous burn eschar as the coverage of microskin grafting in the repair of excised severe burn wounds. METHODS: Twelve severe burn patients underwent massive escharectomy during 3 to 7 post burn days (PBD), and autologous eschar instead of alloskin was employed as the coverage of microskin. The integrity of grafted eschar and survival of microskin grafts were observed at 1 to 6 weeks after operation. The wound healing rate in grafted area was determined at 6 post operation week (POW), and the wound healing time was recorded. RESULTS: The autologous eschar in the grafted area were integral and attached tightly to the wound during the 1 to 2 POW and began to dry and detach from the burn wound with the microskin underneath growing and fusing at 3-4 POW. This process went on until the eschar was completely detached from the burn wound and the microskin fused in large areas, with some granulation wounds left at 5 and 6 POW. The wound healing rate at the 6 POW was (87 +/- 4)%. The average wound healing time of burn patients in this group was (56 +/- 8) days. CONCLUSION: Autologous eschar could be used as a substitute for the alloskin for microskin grafting in excised burn wounds.