Altered actin dynamics is possibly implicated in the inhibition of mechanical stimulation-induced dermal fibroblast differentiation into myofibroblasts.

The formation of hypertrophic scars and keloids is strongly associated with mechanical stimulation, and myofibroblasts are known to play a major role in abnormal scar formation. Wounds in patients with neurofibromatosis type 1 (NF1) become inconspicuous and lack the tendency to form abnormal scars. We hypothesized that there would be a unique response to mechanical stimulation and subsequent scar formation in NF1. To test this hypothesis, we investigated the molecular mechanisms of differentiation into myofibroblasts in NF1-derived fibroblasts and neurofibromin-depleted fibroblasts and examined actin dynamics, which is involved in fibroblast differentiation, with a focus on the pathway linking LIMK2/cofilin to actin dynamics. In normal fibroblasts, expression of α-smooth muscle actin (α-SMA), a marker of myofibroblasts, significantly increased after mechanical stimulation, whereas in NF1-derived and neurofibromin-depleted fibroblasts, α-SMA expression did not change. Phosphorylation of cofilin and subsequent actin polymerization did not increase in NF1-derived and neurofibromin-depleted fibroblasts after mechanical stimulation. Finally, in normal fibroblasts treated with Jasplakinolide, an actin stabilizer, α-SMA expression did not change after mechanical stimulation. Therefore, when neurofibromin was dysfunctional or depleted, subsequent actin polymerization did not occur in response to mechanical stimulation, which may have led to the unchanged expression of α-SMA. We believe this molecular pathway can be a potential therapeutic target for the treatment of abnormal scars.

Periostin is induced by IL-4/IL-13 in dermal fibroblasts and promotes RhoA/ROCK pathway-mediated TGF-ß1 secretion in abnormal scar formation.

Excess scar formation can occur after skin injurふy and lead to abnormal scar formation, such as keloids and hypertrophic scars, which are characterised by substantial deposition of extracellular matrix in the dermis. Periostin, an extracellular matrix protein that plays a crucial role in skin development and maintaining homeostasis, is also involved in skin disorders such as systemic/limited scleroderma, wound closure, and abnormal scar formation. However, the mechanism of periostin involvement in abnormal scar formation is not yet fully understood. In this study, we investigated the mechanism by which periostin is involved in abnormal scar formation. Treatment of human dermal fibroblasts (HDFs) with IL-4 and IL-13, which are cytokines of Th2 type immune responses that are up-regulated in abnormal scars, dramatically elevated the levels of periostin mRNA and protein, and also promoted the secretion of periostin by HDFs. Transforming growth factor-ß1 (TGF-ß1) had the same effect on HDFs as IL-4 and IL-13. Stimulation of HDFs with periostin promoted RhoA/ROCK pathway-mediated TGF-ß1 secretion from HDFs. Our results suggest that IL-4 and IL-13 induce periostin expression and secretion, and in turn, secreted periostin induces RhoA/ROCK pathway-mediated TGF-ß1 secretion. Secreted TGF-ß1 then induces further periostin production and secretion, thereby promoting abnormal scar formation.

Neurovascular interactions in skin wound healing.

Skin wound healing is a complex and dynamic biological process that involves many different cell types, the extracellular matrix, and mediators, such as neuropeptides, growth factors, and cytokines. Similar to diseases of the central nervous system, neurovascular interactions have been shown to play a pivotal role in skin wound healing, for example, as seen in the delayed healing of denervated skin. In aspects involving neurovascular interactions, while angiogenesis is considered important, physiological and pathological roles of these interactions in skin wound healing remain unclear. In this review, we discuss recent findings on neurovascular interactions in skin wound healing, with a particular focus on angiogenesis.

Salvage Treatment of Failed Free Jejunal Flap Transfer: Our Experiences and Literature Review.

BACKGROUND: Although there have been many reports on the success of free jejunal flap transfer for pharyngoesophageal reconstruction, reports on salvage procedures for failed transfers remain sparse. In this report, we retrospectively reviewed our salvage procedures for failed jejunal transfers and previous articles describing salvage treatment in failed jejunal flap cases. METHODS: This report includes 6 cases of failed jejunal flap transfer, leading to necessary salvage surgery. We reviewed all cases to examine salvage procedures and early postoperative complications such as fistula formation. We also assessed postoperative late complications and swallowing function during long-term follow-up. A review of the literature was performed via PubMed. RESULTS: Rejejunal transfer was performed successfully in 3 of 6 cases. Gastric pull-up reconstruction was adopted in 2 cases. In 1 case, an external stoma was created because of the patient's poor medical condition. All 3 cases of rejejunal transfer and 1 gastric pull-up case recovered to resuming a normal diet. However, 1 gastric pull-up case required supplemental feeding with a jejunostomy tube. We reviewed 6 articles describing salvage treatment in failed jejunal flap cases. CONCLUSION: When free jejunal transfer fails, rejejunal transfer is optimal. However, in cases that lack suitable recipient vessels or have infection, a second jejunal transfer should not be considered. In such cases, gastric pull-up or colon interposition may be an alternative because they do not require vascular anastomosis. Pedicled pectoralis major flap is also an alternative, although the risk of salivary fistulas is very high.

Cutaneous resurfacing around a permanent tracheostoma with an internal mammary artery perforator flap.

When soft tissue reconstruction near a permanent tracheostoma is needed, transfer of a thin and pliable flap is preferable in order to avoid occlusion of the newly created tracheostomal opening. Although microsurgical fasciocutaneous flap transfer may be desirable for such reconstruction, it is not always an option due to lack of recipient vessels for vascular anastomosis or a patient's poor medical condition that would prohibit a lengthy procedure. An alternative option is the internal mammary artery perforator flap, which is easy to elevate, has a long arc of rotation, and has a reliable blood supply. Here, we report three cases of cutaneous resurfacing around a permanent tracheostoma with an internal mammary artery perforator flap.

Hydroxyapatite implantation for the repair of a congenital nasal anomaly: 10 years follow-up.

Frontonasal dysplasia is a rare congenital anomaly characterized by ocular hypertelorism, a broad nasal root, and vertical median cleft of the nose and/or upper lip and palate. We report a case of frontonasal dysplasia in which hydroxyapatite was used to treat a nasal deformity in early childhood. In the 10 years of follow-up of our case, there were no complications such as infection, malpositioning, or exposure, and computed tomography revealed no resorption or malpositioning of the implant. Hydroxyapatite implants may be a viable alternative to autologous bone/cartilage grafts for the repair of congenital nasal anomalies until nasal development is completed.

Free Flap Survival Despite Internal Jugular Vein Thrombosis in Head and Neck Reconstruction.

Microvascular free tissue transfer is one of the most common techniques of reconstruction for complex head and neck surgical defects. Generally, venous thrombosis is more likely to occur than arterial thrombosis in vascular anastomosis. Thus, recipient veins must be chosen carefully. Although the internal jugular vein is preferred as a recipient vein by many microsurgeons, internal jugular vein thrombosis is a potential complication, as shown in our report. Therefore, we consider that the external jugular vein still is an option as a recipient for venous anastomosis and that it is better to perform multiple vein anastomoses with 2 different venous systems, such as the internal and external jugular systems, than anastomoses within the same venous system.

STRATAFIX for Abdominal Wall Repair following Abdominal Flap Harvest.

Supplemental Digital Content is available in the text.

Endothelial cell-derived endothelin-1 is involved in abnormal scar formation by dermal fibroblasts through RhoA/Rho-kinase pathway.

Hypertrophic scars and keloids are characterized by excessive dermal deposition of extracellular matrix due to fibroblast-to-myofibroblast differentiation. Endothelin-1 (ET-1) is primarily produced by vascular endothelial cells and plays multiple roles in the wound-healing response and organ fibrogenesis. In this study, we investigated the pathophysiological significance of ET-1 and involvement of RhoA, a member of the Rho GTPases, in hypertrophic scar/keloid formation. We found that ET-1 expression on dermal microvascular endothelial cells (ECs) in hypertrophic scars and keloids was higher than that in normal skin and mature scars. We also confirmed that ET-1 induced myofibroblast differentiation and collagen synthesis in cultured human dermal fibroblasts through the RhoA/Rho-kinase pathway. Finally, since hypertrophic scar/keloid formation was most prominent in areas exposed to mechanical stretch, we examined how mechanical stretch affected ET-1 secretion in human dermal microvascular ECs, and found that mechanical stretch increased ET-1 gene expression and secretion from ECs. Taken together, these results suggest that dermal microvascular ECs release ET-1 in response to mechanical stretch, and thereby contribute to the formation of hypertrophic scars and keloids through the RhoA/Rho-kinase pathway.

Differentiated adipose-derived stem cells promote the recovery of nociceptor function in rats.

The loss of nociceptive function in the skin because of trauma or surgery can impair the quality of life. The recovery of nociceptor function is mediated by two different axonal responses: nerve growth factor (NGF)-dependent collateral sprouting of undamaged nerves and NGF-independent regeneration of damaged nerves. We reported previously that adipose-derived stem cells (ASCs) can transdifferentiate into Schwann cell (SC)-like cells (dASCs) and that transplantation of dASCs increases axonal density in skin flaps. In the present study, we used an animal model that allowed for the individual assessment of collateral sprouting and regeneration. In-vitro differentiation of ASCs to dASCs significantly increased the production of NGF and brain-derived neurotrophic factor (BDNF) to levels comparable with SCs. In-vivo experiments showed that dASC and SC transplantation significantly increased the area of the mechano-nociceptive field in both collateral sprouting and regeneration models, whereas ASC transplantation exerted no significant effect. Antibody blocking experiment showed that these effects of dASC transplantation in the regeneration model were partly mediated by BDNF. Interestingly, the final areas of nociceptive fields between the two experimental models did not differ significantly for any treatment condition. These results indicate that dASC transplantation differentially facilitates collateral sprouting and axonal regeneration by delivering NGF and other neurotrophic factors (e.g. BDNF), respectively. Although there is a limit to nociceptive field enlargement irrespective of axonal response, dASC transplantation could present a new approach for improving nociceptive function in denervated skin.

Behavior of anastomozed vessels and transferred flaps after anastomosed site infection in head and neck microsurgical reconstruction.

OBJECTIVE: This report evaluates the behavior of anastomosed vessels and transferred flaps after anastomosed site infection in head and neck reconstruction. PATIENTS AND METHODS: Eleven free-flap cases after infection at the vascular pedicle site were included, the patency of which was observed macroscopically after re-exploration and pus drainage. Location was in the tongue (5 cases), oropharynx (3 cases), mouth floor (1 case), mandible (1 case), and hypopharynx (1 case). Transferred flaps originated from rectus abdominis (3 cases), anterolateral thigh (3 cases), radial forearm (3 cases), jejunum (1 case), and latissimus dorsi (1 case). Days for infection found were ranged 3-14 days postoperatively. Causes of infection were the salivary fistula formation in 5 cases, and precise etiology was not defined in the other 6 cases. RESULTS: Disruption of the vascular pedicles occurred with high frequency after infection. Disruption of vein occurred most frequently (5 cases), followed by both artery and vein (2 cases) and artery only (1 case). Of the eight flaps, two flaps failed, but the other six flaps survived despite pedicle disruption, indicating overall survival of nine flaps after pedicle site infection. Five of the nine survived cases were healed with simple washing and ointment application. However, the other four patients, whose cause of infection was a salivary fistula, needed second flap transfer to treat those fistulas. CONCLUSION: Disruption of anastomosed vessels can occur with high frequency after infection, causing subsequent flap loss. Therefore, surgeons need to deal with pedicle site infection to save the flap. © 2015 Wiley Periodicals, Inc. Microsurgery 36:658-663, 2016.

Physiological ER Stress Mediates the Differentiation of Fibroblasts.

Recently, accumulating reports have suggested the importance of endoplasmic reticulum (ER) stress signaling in the differentiation of several tissues and cells, including myoblasts and osteoblasts. Secretory cells are easily subjected to ER stress during maturation of their secreted proteins. Skin fibroblasts produce and release several proteins, such as collagens, matrix metalloproteinases (MMPs), the tissue inhibitors of metalloproteinases (TIMPs) and glycosaminoglycans (GAGs), and the production of these proteins is increased at wound sites. Differentiation of fibroblasts into myofibroblasts is one of the key factors for wound healing and that TGF-ß can induce fibroblast differentiation into myofibroblasts, which express α-smooth muscle actin. Well-differentiated myofibroblasts show increased production of collagen and TGF-ß, and bring about wound healing. In this study, we examined the effects of ER stress signaling on the differentiation of fibroblasts, which is required for wound healing, using constitutively ER stress-activated primary cultured fibroblasts. The cells expressed positive α-smooth muscle actin signals without TGF-ß stimulation compared with control fibroblasts. Gel-contraction assays suggested that ER stress-treated primary fibroblasts caused stronger shrinkage of collagen gels than control cells. These results suggest that ER stress signaling could accelerate the differentiation of fibroblasts to myofibroblasts at injured sites. The present findings may provide important insights for developing therapies to improve wound healing.

A novel active intraoral appliance for presurgical orthopaedic treatment in patients with complete bilateral cleft lip and palate.

BACKGROUND: Management of the protruding/deviated premaxilla in patients with complete bilateral cleft lip and palate is a challenging problem for surgeons and orthodontists. Various passive and active methods have been developed for the presurgical orthopaedic treatment. However, most of these treatments are complicated and laborious for the patient's parents and clinicians. Here, we describe our original active intraoral appliance comprising two components, that is, the premaxillary and palatine process plates, connected with two elastic chains, and we assess its therapeutic efficacy. PATIENTS AND METHODS: We retrospectively evaluated 15 patients treated using this appliance during 2006-2012, followed up for an average of 60.3 months (range, 18-97 months). We analysed the cleft widths and maxillary size, obtained pretreatment, post-treatment and pre-palatoplasty. RESULTS: Cleft widths and premaxillary protrusion were significantly decreased post treatment; however, the transverse dimensions were not significantly altered. In all cases, the protruding/deviated premaxilla was set into a suitable position within 1 month, and we could perform one-stage cheiloplasty using the modified Mulliken method with low tension. CONCLUSION: Our appliance is technically simple to use, less invasive to the skin and bone and cost-effective, with reliable and predictable outcomes. In the follow-up period, we observed no detrimental growth of the maxilla or dentition. Therefore, we consider our appliance to be useful for application in presurgical orthopaedic treatments of complete bilateral cleft lip and palate.

Simultaneous correction of deviated columella and wide nostril floor using the Y-V advancement in unilateral cleft lip nasal deformities.

Here, we describe an operative method for the simultaneous correction of deviated columella and wide nostril floor in unilateral cleft lip nasal deformities. The V-shaped flap of the affected nostril floor was inserted into the side wall of the columella using the Y-V advancement. By suturing the anterocaudal septum, which is often deviated to the unaffected side, with the subcutaneous tissue of the affected alar base, it was possible to simultaneously reposition the columellar base in the midline as well as narrow the wide nostril floor. This method was technically simple, with low invasiveness for the septal cartilage. Furthermore, as noted in one of the two cases described, it would enable the reconstruction of the natural shape of the nostril sill.

A novel pre-surgical maxillary orthodontic device using ß-titanium wire for wide unilateral cleft lip and palate patients: preliminary study of its efficacy and impact for the maxillary formation.

BACKGROUND AND AIM: For patients with a wide, complete, unilateral cleft lip and palate, pre-surgical maxillary orthodontic treatments have been used to reduce the alveolar gap before cheiloplasty. However, most of these treatments are complicated and laborious for patients and for medical professionals. Thus, we developed an original pre-surgical orthodontic device made with two separate acrylic resin plates connected with a spring-shaped ß-titanium wire (ß-TW). When the device was applied on the palate, each segment of the maxilla was automatically aligned for our target formation with the elastic force of ß-titanium alloy. This study aimed to evaluate the efficacy of the new device and the size of the maxilla in comparison with the conventional Hotz procedures. PATIENTS AND METHODS: A total of 47 patients with a wide unilateral cleft lip and palate were retrospectively evaluated; 33 patients were treated with our new device (ß-TW plate group) and 14 were treated with a Hotz plate (HP group). We evaluated the alveolar gap reduction and the size of the maxilla between the two groups, obtaining intraoral maxillary impressions at birth, at 3 months and 1 year. RESULTS: The width of the alveolar gap in the ß-TW plate group was significantly reduced compared with that in the HP group 1 month after the treatment (p < 0.001). The alveolar gap reduction continued until the age of 1 year (p = 0.02). By contrast, no significant difference in the maxillary size was observed between the two groups at any examination period. CONCLUSION: Our treatment protocol using the ß-TW plate was not only easy and simple to apply but it was also cost-effective, with highly predictable outcomes. Moreover, it provided the ideal alveolar cleft reduction without detrimental collapse of the alveolar segments. Therefore, we consider our ß-TW plate device to be useful for application in pre-surgical orthodontic treatments.