Glucocorticoids suppress fibroblast apoptosis in an in vitro thermal injury model.

The wounds of full- and deep partial-thickness burns result in hypertrophic scars and lead to skin contracture more severely than those of superficial partial-thickness burns. Therefore, preventing burn progression may help improve the aesthetic and functional outcomes after healing. Although a number of studies have focused on elucidating the underlying mechanisms of and preventing burn wound progression, it is still difficult to rescue burned dermis unless early tangential excision is performed. To investigate the underlying mechanisms of and prevent cell death of heat-injured fibroblasts, we developed an in vitro experimental model of heat-injured fibroblasts. We confirmed that heating at 55°C for 30s caused fibroblast necrosis immediately after heating, whereas heating at 46°C for 30s induced apoptosis 24h after heating. We also found that the supplementation of 100ng/ml betamethasone to the culture medium after heating decreased the number of apoptotic cells and increased that of live cells. Our studies suggest that glucocorticoids suppress apoptosis of heat-injured fibroblasts and may be useful for preventing burn wound progression.

The Lesser Palatine Nerve Innervates the Levator Veli Palatini Muscle.

When the lesser palatine nerve (LPN) is supposed to be a branch of the trigeminal nerve and innervate sensation of the soft palate, whether the LPN contains motor fibers is unclear. In this study, we monitored the electromyogram of the levator veli palatini (LVP) muscle on stimulating the LPN during palatoplasty in 3 patients. The electromyogram of the muscles showed the myogenic potential induced by electrostimulation of the LPN. Taken together with the finding from our previous anatomical study that the motor fibers come from the facial nerve, this result supports the double innervation theory of the LVP, which posits that both the pharyngeal plexus and the facial nerve innervate it. Identifying and preserving the LPN during palatoplasty might improve postoperative speech results.

Efficacy of gelatin gel sheets in sustaining the release of basic fibroblast growth factor for murine skin defects.

BACKGROUND: Gelatin has been used as a material sustaining the release of basic fibroblast growth factor (bFGF), which promotes fibroblast proliferation and capillary formation and accelerates wound healing. In the application of these materials, bFGF is impregnated immediately before application, and it is difficult to conform the shape to the wound. In this study, we prepared a pliable and plastic gelatin gel sheet (GGS) that sustains bFGF and conforms to the shape of the wound as a result of cross-linking just before application. In addition, we examined the sustained release profile of bFGF from GGS and its effect on wound healing in murine skin defects. MATERIALS AND METHODS: A 13-wt% gelatin solution was mixed with bFGF before cross-linking with 1% glutaraldehyde solution. GGSs impregnated with 7 µg/cm(2) of bFGF were incubated in phosphate-buffered saline and collagenase solution, and GGS degradation and bFGF release were evaluated. In the murine experiments, GGSs treated without bFGF and GGSs impregnated with 1, 3.5, 7, or 14 µg/cm(2) of bFGF were applied to full-thickness skin defects created on the backs of C57BL/6JJcl mice, and the wound closure, epithelial length, extent of granulation tissue and capillary formation were compared. RESULTS: bFGF was released according to the degradation of GGS in phosphate-buffered saline, and the remaining bFGF was released in collagenase solution. In the animal studies, epithelialization was accelerated in the GGSs treated with 1 and 3.5 µg/cm(2) of bFGF, and granulation tissue formation and angiogenesis were promoted based on the amount of bFGF impregnated into the GGS. CONCLUSIONS: GGS impregnated with bFGF is capable of sustaining the release of bFGF, with consequent accelerated epithelialization, granulation tissue formation, and angiogenesis in vivo. GGS is a novel and promising wound dressing that sustains bFGF and can be adapted to the shape of various wounds in the treatment of both acute and chronic wounds.

Exploration of the wound healing effect of topical administration of nicotine in combination with collagen scaffold in a rabbit model.

Nicotine has been reported to prolong the wound healing; however, we showed that the topical application of 10(-4) M nicotine promoted murine wound healing. The objective of this study was to explore the wound healing effects of nicotine in combination with collagen scaffold using skin defects in rabbit. Three full-thickness skin defects 8 mm in diameter were made on the rabbit auricle. Artificial dermis was applied to the defects, and 10 µl of nicotine solution (10(-5), 10(-4), and10(-3) M), bFGF solution (0.5 µg/10 µl), and both bFGF and 10(-4) M nicotine solutions were injected into the artificial dermis once daily for 7 days. Rabbits were sacrificed on day 10, 15, or 20, and the wound healing process was evaluated. bFGF was superior in the formation of the dermis-like tissue and capillaries. In nicotine groups, the epithelial length and the dermis-like tissue formations in the 10(-4) M group were superior, in contrast, those were inhibited in the 10(-3) M group. The synergistic effect of bFGF and 10(-4) M nicotine was not confirmed. This study suggests that the topical application of 10(-4) M nicotine promoted wound healing in rabbit, but the effect was not apparent compared with murine models.

Response to comment on "Drug screening for ALS using patient-specific induced pluripotent stem cells".

Our work and the study of Bilican et al. highlight the need for complementary assays to detect subtle phenotypic differences between control and mutant induced pluripotent stem cell lines.

Chondroitinase injection improves keloid pathology by reorganizing the extracellular matrix with regenerated elastic fibers.

Keloids are a proliferative fibrotic disease characterized by abnormal accumulation of extracellular matrix in the dermis. Keloid lesions lack skin plasticity due to deficiencies in elastic fiber formation in the extracellular matrix. The loss of elastic fiber is caused by excessive accumulation of chondroitin sulfate (CS), a sulfated glycosaminoglycan. However, there is no radical cure for keloids. Using a model system, we show herein that treatment of keloid tissues with chondroitinase ABC, an enzyme that specifically digests CS, improves clinical features of keloids. Keloid tissues obtained from patients were grafted on nude mice, and chondroitinase ABC was injected into the grafted keloid tissues. Chondroitinase ABC treatment significantly reduced the volume of keloid implants concomitant with recovery of elastic fiber formation. These results suggest that chondroitinase ABC injection is an effective therapy for keloid.

Drug screening for ALS using patient-specific induced pluripotent stem cells.

Amyotrophic lateral sclerosis (ALS) is a late-onset, fatal disorder in which the motor neurons degenerate. The discovery of new drugs for treating ALS has been hampered by a lack of access to motor neurons from ALS patients and appropriate disease models. We generate motor neurons from induced pluripotent stem cells (iPSCs) from familial ALS patients, who carry mutations in Tar DNA binding protein-43 (TDP-43). ALS patient-specific iPSC-derived motor neurons formed cytosolic aggregates similar to those seen in postmortem tissue from ALS patients and exhibited shorter neurites as seen in a zebrafish model of ALS. The ALS motor neurons were characterized by increased mutant TDP-43 protein in a detergent-insoluble form bound to a spliceosomal factor SNRPB2. Expression array analyses detected small increases in the expression of genes involved in RNA metabolism and decreases in the expression of genes encoding cytoskeletal proteins. We examined four chemical compounds and found that a histone acetyltransferase inhibitor called anacardic acid rescued the abnormal ALS motor neuron phenotype. These findings suggest that motor neurons generated from ALS patient-derived iPSCs may provide a useful tool for elucidating ALS disease pathogenesis and for screening drug candidates.

Green tea polyphenols affect skin preservation in rats and improve the rate of skin grafts.

Green tea polyphenols have been recently reported to promote the preservation of tissues, such as blood vessels, corneas, nerves, islet cells, articular cartilage, and myocardium, at room temperature. These findings indicate the possibility of a new method of tissue banking without freezing. A main active ingredient of green tea, epigallocatechin-3-gallate (EGCG), is a polyphenol that possesses antioxidant, antimicrobial, antiproliferative, and free radical scavenging effects. This study examined the effects of EGCG regarding skin preservation. Skin sample biopsy specimens measuring 1 x 1 cm from GFP rats were held in sterile containers with 50 ml preserving solution at 4 degrees C and 37 degrees C for up to about 8 weeks. Periodically, some of the preserved skin specimens were directly examined histologically and others were transplanted into nude mice. Histological examinations of skin preserved at 4 degrees C revealed a degeneration of the epidermal and dermal layers from 5 weeks in all groups. In the groups preserved at 37 degrees C, degeneration and flakiness of the epidermal layer were demonstrated starting at 2 weeks preservation regardless of addition of EGCG. After 2-7 weeks of preservation the rat skin grafted to nude mice in the EGCG groups stored at 4 degrees C showed successful engraftment. However, grafts preserved at 4 degrees C without EGCG and at 37 degrees C did not demonstrate GFP-positive keratinocyte or fibroblasts. In conclusion, the present findings suggest the future clinical usefulness of EGCG for skin preservation without freezing; however, the mechanism by which EGCG promotes skin preservation still remains unclear.