Combination of chemically modified SDF-1α mRNA and small skin improves wound healing in diabetic rats with full-thickness skin defects.

OBJECTIVES: Diabetes mellitus is associated with refractory wound healing, yet current therapies are insufficient to accelerate the process of healing. Recent studies have indicated chemically modified mRNA (modRNA) as a promising therapeutic intervention. The present study aimed to explore the efficacy of small skin engineered to express modified mRNAs encoding the stromal cell-derived factor-1α (SDF-1α) facilitating wound healing in a full-thickness skin defect rat model. This study, devised therapeutic strategies for diabetic wounds by pre-treating small skin with SDF-1α modRNA. MATERIALS AND METHODS: The in vitro transfection efficiency was evaluated using fluorescence microscopy and the content of SDF-1α in the medium was determined using ELISA after the transfection of SDF-1α into the small skin. To evaluate the effect of SDF-1α modRNA and transplantation of the small skin cells on wound healing, an in vivo full-thickness skin defect rat model was assessed. RESULTS: The results revealed that a modRNA carrying SDF-1α provided potent wound healing in the small skin lesions reducing reduced scar thickness and greater angiogenesis (CD31) in the subcutaneous layer. The SDF-1α cytokines were significantly secreted by the small skin after transfection in vitro. CONCLUSIONS: This study demonstrated the benefits of employing small skin combined with SDF-1α modRNA in enhancing wound healing in diabetic rats having full-thickness skin defects.

Ribosomal S6 Protein Kinase 2 Aggravates the Process of Systemic Scleroderma.

Systemic sclerosis is a complex process of pathogenesis, and the contributions of inherited genes, infections, and chemicals remain largely unknown. In this study, we showed that p90 ribosomal S6 protein kinase 2 (RSK2) was selectively upregulated in fibrotic skin and fibroblasts treated with the profibrotic cytokine TGF-ß. Moreover, knockout of Rsk2 specifically in skin fibroblasts or pharmacological inhibition of RSK2 attenuated skin fibrosis in a mouse model. Mechanistically, RSK2 directly interacted with glycogen synthase kinase 3ß in vivo and in vitro and thereby induced phosphorylation of glycogen synthase kinase 3ß at Ser9 to inhibit ubiquitination and degradation of GLI1, which promoted fibroblast differentiation and skin fibrosis. Consequently, RSK2 plays an important role in the dermal skin of systemic sclerosis. These findings provided a potential therapeutic target for systemic sclerosis.

Fibroblast growth factor 10 protects against UVB-induced skin injury by activating the ERK/YAP signalling pathway.

OBJECTIVES: Ultraviolet light B (UVB) irradiation can induce skin injury and result in keratinocytes proliferation inhibition. However, the molecular understanding of the repair during UVB-induced cell proliferation inhibition remains poorly understood. The purpose of this study was to explore the role and potential mechanism of FGF10 in promoting keratinocytes cell cycle and proliferation after UVB injury. MATERIALS AND METHODS: Expression of FGF10 protein was analysed in skin treated with UVB radiation by immunohistochemistry. The proliferation potential was examined by Immunofluorescence, Western Blot and RT-PCR under UVB radiation, treated with FGF10 protein or overexpression of FGF10 using adeno-associated virus. CCK8 kit was used to further detect cell proliferation ability. RESULTS: We found that FGF10 is highly expressed in skin treated with UVB. Overexpression of FGF10 has a protective effect against UVB-induced skin damage by balancing epidermal thickness and enhancing epidermal keratinocytes proliferation. Importantly, FGF10 is found to alleviate UVB-induced downregulation of YAP activity, then promoting keratinocytes proliferation. Disruption of YAP function, either with the small molecule YAP inhibitor Verteporfin (VP) or YAP small-interfering RNA (siRNA), largely abolishes the protective activity of FGF10 on epidermal keratinocytes proliferation. Meanwhile, disruption of ERK kinase (MEK) activity with U0126 or ERK siRNA hinder the positive influence of FGF10 on UVB-induced skin injury. CONCLUSION: FGF10 promotes epidermal keratinocytes proliferation during UVB-induced skin injury in an ERK/YAP-dependent manner.

Scutellarin Attenuates the IL-1ß-Induced Inflammation in Mouse Chondrocytes and Prevents Osteoarthritic Progression.

Osteoarthritis (OA) is a chronic degenerative disease wherein the articular cartilage exhibits inflammation and degradation. Scutellarin (SCU) is a flavonoid glycoside with a range of pharmacological activities, as shown in previous studies demonstrating its anti-inflammatory activity. How SCU impacts the progression of OA, however, has not been explored to date. Herein, we assessed the impact of SCU on murine chondrocytes in an OA model system. In in vitro assays, we measured chondrocyte expression of key OA-associated factors such as matrix metalloproteinase 13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) via qRT-PCR and Western blotting, the expression of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2) were detected by qRT-PCR. Our results showed that the downregulation of MMP-13, ADAMTS-5, COX-2, and iNOS expression by SCU and the overproduction of IL-6, TNF-α, and PGE2 induced by IL-1ß were all inhibited by SCU in a concentration-dependent manner. Moreover, SCU was able to reverse aggrecan and collagen II degradation and nuclear factor-κB (NF-κB) and nuclear factor erythroid-derived 2-like 2 (Nrf2) signaling pathway activation both in vivo and in vitro. We further used a destabilization of the medial meniscus (DMM) murine model of OA to explore the therapeutic benefits of SCU in vivo. Together, our findings suggest SCU to be a potentially valuable therapeutic agent useful for treating OA.

Comparison of various reagents for preparing a decellularized porcine cartilage scaffold.

Cartilage lesion repair is difficult due to the limited self-repair capability of cartilage and its lack of vascularization. Our previous study established a sandwich model for engineering cartilage with acellular cartilage sheets (ACSs) and chondrocytes. However, there is still debate over which agent achieves the optimal decellularization of cartilage sheets. In addition, changes in the extracellular matrix after decellularization are worth studying. We aimed to determine the optimal decellularization reagents and decellularization time for preparing cartilage sheets. This study compared the effects of 2 extraction chemicals [t-octylphenoxypolyethoxyethanol (Triton X-100) and sodium dodecyl sulfate (SDS)] on cartilage sheets. The sheets were soaked in various concentrations (0.1-2%) of the extraction solutions for various time periods (24-72 h). After the decellularization process with the various treatments, we examined the cell removal and preservation of the matrix components and microstructure to determine which method was the most efficient while inducing minimal damage to the perichondrium. Both protocols achieved decellularization within an acceptable time. DNA analysis showed that the reagent removed nearly all of the DNA from the cartilage sheets. The growth factor contents in the Triton X-100 samples were higher than those in the SDS samples, quantified by enzyme-linked immunosorbent assay (ELISA). Furthermore, Triton X-100 decreased the glycosaminoglycan (GAG) and increased the chondromodulin-I contents compared with SDS. The results of a Cell Counting Kit-8 (CCK-8) assay revealed that the ACSs were not cytotoxic. In conclusion, our results demonstrate that cartilage sheets decellularized by 1% SDS for 24 h or by 2% Triton X-100 for 48 h may be suitable candidate scaffolds for cartilage tissue engineering.

Distally based sural neuro-fasciocutaneous perforator flap for foot and ankle reconstruction: Surgical modifications for flap pedicle and donor site closure without skin graft.

BACKGROUND: The conventional procedure of the sural neuro-fasciocutaneous flap enables the supply of blood and venous drainage by increasing the width of the adipofascial tissue and preserving tiny venous return routes. Moreover, skin graft is a common method for donor site closure, which may lead to some complications and influence the aesthetic appearance. We report modifications for a distally based sural neuro-fasciocutaneous perforator flap and a relaying flap for donor site closure without skin graft. METHODS: Twelve patients undergoing the modified flap for foot and ankle reconstruction were included in this study between 2014 and 2016. A peroneal-based perforator, a superficial vein, and the vascular axis of the sural nerve were included in the pedicle. A Z-shape skin incision was performed to explore the perforator vessels and a relaying island perforator flap was used to close the donor site. RESULTS: All flaps survived completely without necrosis. The area of the flaps ranged from 16 × 8 cm to 30 × 15 cm. The diameter width of the pedicle ranged from 1.0 to 2.0 cm. A relaying perforator island flap was used in 10 cases for donor site closure and no skin graft was performed. There were no serious donor site complications. All patients were satisfied with the aesthetic outcome postoperatively at the final follow-up. CONCLUSIONS: The distally based sural neuro-fasciocutaneous perforator flap is considered a reliable method for foot and ankle reconstruction. The modification for flap pedicle and donor site closure method without skin graft should be recommended.

Reconstruction of totally degloved fingers: a novel application of the bilobed spiraled innervated radial artery superficial palmar branch perforator flap design provides for primary donor-site closure.

INTRODUCTION: To investigate the results of resurfacing completely degloved digits using bilobed innervated radial artery superficial palmar branch (RASPB) perforator flap in a spiral fashion. METHODS: A detailed anatomic study on 30 adult fresh frozen cadavers preinjected with silicone rubber compound to demarcate arterial anatomy documented locations, numbers, and diameters of arteries and skin perforators with surrounding nerves. The flap-raising procedure was performed using four fresh cadaver specimen. We reviewed the reconstruction of 12 digits by using a bilobed spiraled innervated RASPB free perforator flap after non-replantable degloving injury. Two skin paddles were marked out using standard points of reference. At least two separate cutaneous perforator vessels were identified using a hand-held Doppler and were dissected back to the RASPB in retrograde fashion. The skin paddles were then divided between the two cutaneous perforators to provide two separate paddles with a common vascular supply. The skin paddles were stacked in a spiral fashion on the flap inset, effectively increasing the width of the flap to cover the totally degloved finger while still allowing closure of the primary donor-site. RESULTS: The RASPB was present within the flap in all cadavers. The direct perforator and the musculocutaneous perforator were available in 93.33 and 76.67 %, respectively, with neither of them in 6.67 % of the cases. The constantly present two perforators allowed the design of a new bilobed spiraled innervated radial artery superficial palmar branch perforator flap. We used the proposed flap to reconstruct completely degloved digits in 12 patients (mean age 28.6 years; range 17-35 years). With our proposed flap, no flap failure or re-exploration occurred and the donor site was closed primarily in all cases. All the flaps survived uneventfully. Total active motion ranged from 92° to 140° and 111° to 155° in the cases with and without metacarpophalangeal joint involvement, respectively. The static 2 point discrimination test varied from 6 to 11 mm. All the patients were satisfied with the overall results. CONCLUSION: The bilobed flap is large enough to cover totally degloved finger defects and contain direct skin perforators, provides a bespoke cover for complex soft tissue defects of completely degloved digits while also improving morbidity and cosmesis of the donor site. LEVEL OF EVIDENCE: Level IV, retrospective series.

Expression and purification of FGF21 in Pichia pastoris and its effect on fibroblast-cell migration.

Fibroblast growth factor (FGF)21 functions in the maintenance of glucose homeostasis and exerts protective effects on the liver, heat and kidneys. However, the roles of FGF21 in other tissue types are yet to be fully elucidated. The present study detected elevated expression levels of FGF21 in skin tissue. Furthermore, it was revealed that FGF21 expression in the skin was induced upon wounding. In addition, ß­klotho expression was detected in the skin tissue. To examine the role of FGF21 in the wound healing process, recombinant human (h)FGF21 was expressed in a the yeast strain Pichia (P.) pastoris, a well­known system for recombinant protein production. Based on the sequence of hFGF21 and the optimal codon of P. pastoris, codon­optimized FGF21 open reading frame sequences were obtained using seven pairs of 55­59­nt primers with seven rounds of PCR. The recombinant FGF21 was purified and its function was examined in human fibroblast cells using a wound healing cell migration assay. Treatment with FGF21 promoted cell migration, which is an important step in wound healing. Furthermore, FGF21 treatment enhanced the activity of c­Jun N­terminal kinase, a key regulator in fibroblast­cell migration. In conclusion, FGF21 is induced after wounding and FGF21 expressed and purified from yeast markedly accelerates wound healing. The present study was the first to elucidate the function of FGF21 in skin tissues and provided a theoretical basis for the use of FGF21 in the treatment of skin wounds.

[Predictive value of radiological parameter for re-displacement of conservative treatment of distal radius fracture].

OBJECTIVE: To analyze the radiological parameters of the conservatively in treating distal radius fracture and investigate whether the final re-displacement can be predicted after primary reduction. METHODS: From January 2013 to June 2014,212 patients with distal radial fracture conservatively were treated in our hospital, 107 patients of them were excluded because of their incomplete radiological parameters;the remaining 105 patients were available for radiological were assessed after injury, there were 56 male patients and 49 female patients in this study, the average age of the patients was 51 years old (ranged from 22 to 80 years). According to AO classification, there were 47 cases of type A2 and C1, and 58 cases of type A3, C2, C3. All patients were treated by closed reduction and below-elbow cast immobilization for 4 to 6 weeks. All patients were followed up for 3 to 6 months (means 4.5 months) by X-ray, all fractures were healed. Standard AP and lateral radiographic examination was conducted before reduction and after reduction and bony consolidation,the dorsal angulation and the radial angle were measured at each time point. The linear regression was used for the analysis to find out whether the final re-displacement can be predicted after primary reduction. RESULTS: Among 105 patients,the significant correlations were found for the dorsal angulation between the reduction time and the end time (r = 0.82) and for the radial angulation between the reduction time and end time (r = 0.85). CONCLUSION: The dorsal angulation and the radial angulation after complete healing can be predicted from linear the regression functions. Due to the possibility of predicting the end result, whether the fracture should receive further conservative treatment or surgical treatment can be decided immediately.

[Clinical research of vacuum sealing drainage combined with artificial dermis for the treatment of ankle and foot soft tissue defects].

OBJECTIVE: To investigate the effect of vacuum sealing drainage (VSD) combined with artificial dermis for treatment of the ankle and foot soft tissue defects. METHODS: A total of 15 patients with skin and soft tissue defect of ankle and foot were treated from January 2011 to December 2013, including 10 males and 5 females, with an average age of 32.5 years old ranging from 3 to 55 years old, involving 8 cases by traffic accident, 2 cases by machine accident, 5 cases by crush injury;8 cases with soft tissue exposure, 2 cases with tendor exposure, 5 cases with bone exposure. VSD was used to cover the wounds and continuous negative pressure drainage after debridement, the wounds covered with artificial dermis after the second granulation tissue grew well, again VSD was used to cover the wounds and negative pressure suction was applied, after 7 to 14 days negative pressure closed drainage was removed, free skin graft was transplanted above the artificial dermis, sterile gauze was used to compression bandage. RESULTS: All cases were followed up for 3 to 14 months with an average of 6.5 months. Skin graft of 15 of patients survived after transplantation, artificial dermis graft interval was 7 to 14 days with an average of 9.5 days. There was no obvious scar hyperplasia and contracture, no obvious pigmentation, appearance and functional recovery. CONCLUSIONS: After the implantation of artificial dermis and traditional skin graft method need for 2 to 3 weeks, vacuum sealing drainage technique combined with artificial dermis in treatment of soft tissue defect of foot and ankle skin has advantages of simple operation, significantly shorten the time of the second phase of the skin, without flap to repair, little injury to donor skin area, wound healing quality high, clinical effect of satisfaction.

[EFFECTIVENESS OF DORSAL PENTAGONAL FLAP FOR RECONSTRUCTION OF THE WEB SPACE IN CONGENITAL TOE SYNDACTYLY].

OBJECTIVE: To investigate the effectiveness of dorsal pentagonal flap for reconstruction of the web space in congenital toe syndactyly. METHODS: Between January 2009 and June 2014, 10 patients with congenital toe syndactyly were treated for web space reconstruction with dorsal pentagonal flap. There were 6 boys and 4 girls with the average age of 42 months (range, 8 months to 9 years). The congenital toe syndactyly located at the left foot in 5 cases, the right foot in 4 cases, and both feet in 1 case; 7 patients had polydactyly and 1 patient had brachydactylia. During follow-up, the toe function and web space appearance, web space depth, and web space gradient were observed to evaluate the effectiveness. RESULTS: All 13 flaps survived and incisions healed by first intention. Ten patients were followed up 6-50 months (mean, 26 months). The skin color and texture in 13 reconstructed web spaces were close to normal web space. in 9 patients undergoing web spaces reconstruction of single foot, the abduction angle of toes was (42.879±3.703) at the injured side, showing no significant difference when compared with the normal side [(45.922±2.657)°] (t= -2.004, P=0.062); the web space depth was (1.881±0.266) cm at the injured side and was (1.631±0.202) cm at the normal side, showing significant difference (t=2.248, P=0.039); and the web space gradient was (42.733±3.421)° at the injured side and was (41.189±5.593)° at the normal side, showing no significant difference (t=0.707, P=0.490). The web space appearance, web space depth, and web space gradient were close to those of the normal web space in 1 patient undergoing bilateral web spaces reconstruction. CONCLUSION: Web space reconstruction with dorsal pentagonal flap is easy to perform with reliable blood supply and low re-operated rate. The cosmetic and functional results are satisfactory.

[Case-control study on therapeutic effects of different fixation methods for the treatment of olecranon fracture].

OBJECTIVE: To evaluate the clinical effects by comparing three different fixation methods: tension band, hollow lag screw and anatomical plate. METHODS: From January 2010 to January 2012, 82 patients with olecranon fractures who underwent surgical treatments were followed-up. All the patients were divided into three groups: tension band fixation group (group A), hollow lag screw fixation group (group B), anatomical plate fixation (group C). In group A, there were 35 patients, including 19 males and 16 females, ranging in age from 32 to 49 years old, with an average of (43.6 ± 8.7) years old, and the patients were treated with tension band fixation. According to Colton classification, there were 5 cases of type I, 3 cases of type II A,19 cases of type II B, and 8 cases of type II C in group A. Among 20 patients in group B, there were 13 males and 7 females, ranging in age from 27 to 50 years old, with an average of (41.5 ± 9.3) years old. The patients in group B were treated with hollow lag screw fixation. According to Colton classification, there were 4 cases of type I, 4 cases of type II A, and 12 cases of type II B in group B. In group C, there were 27 patients totally, including 15 males and 12 females, ranging in age from 30 to 55 years old, with an average of (38.2 ± 6.2) years old. The patients in group C were treated with anatomical plate fixation. According to Colton classification, there were 4 cases of type II B, 13 cases of type II C, and 10 cases of type II D in group C. The Fracture healing time, complications and functional recovery were retrospectively observed and recorded. RESULTS: All the patients were followed up, and the duration ranged from 8 to 24 months, with an average of 15 months. The average healing time of patients in group C was the longest among three groups. The flexion-extension and rotation activities of elbow joint in group B and C were better than that in group C. According to Broberg & Morrey score system, the therapeutic effects of patients in group A and B were better than that of group C. In group C, 2 patients had incision infections, 6 patients complained of foreign body sensation, 1 patient got a delayed fracture healing, and 1 patient had the heterotopic ossification. There were no occurrences of incision infections in group A and B; internal fixation loosening occurred in 3 patients in group A and 2 patients in group B; delayed fracture healing occurred in 2 patients in group A and 2 patients in group B; and skin bursa formation occurred in 6 patients in group A and 1 patient in group B. CONCLUSION: All the three ways are effective methods for the treatment of olecranon fractures. Fixation methods should be selected depending on the type of fracture.