Activating Parkin-dependent mitophagy alleviates oxidative stress, apoptosis, and promotes random-pattern skin flaps survival.

The random-pattern skin flap is a crucial technique in reconstructive surgery and flap necrosis caused by ischemia/reperfusion injury is a major postoperative complication. Herein, we investigated the mechanism of mitophagy induced by Melatonin (ML) and its effect on the survival of skin flaps. Our results demonstrated that ML could activate mitophagy, ameliorate oxidative stress and alleviate apoptosis in Tert-Butyl hydroperoxide solution (TBHP)-stimulated human umbilical vein endothelial cells in vitro. Inhibiting ML-induced mitophagy considerably abolished its protective effects. Moreover, knockdown of Parkin by siRNA inhibited ML-induced mitophagy, and subsequently exacerbated oxidative stress and apoptosis. Further study demonstrated that inhibition of AMPK reversed these protective effects of ML and downregulated the expression of TFEB. In the vivo study, ML effectively promoted flap survival by activating mitophagy and subsequently ameliorating oxidative stress and mitigating apoptosis. These results established that ML is a potent agent capable for increasing random-pattern skin flap survival by activating Parkin-dependent mitophagy through the AMPK-TFEB signaling pathway.

A hitchhiking approach to reconstruct the finger pulp and the subsequent 1st toe hemi-pulp donor site defect.

BACKGROUND: The free 1st toe hemi-pulp transfer for finger pulp reconstruction was acknowledged as the optimal one. However, the treatment of the 1st toe donor defect, owning to the impossibility of primary closure, was frequently oversimplified. This study presented a "hitchhiking" approach to resurface finger pulp and the subsequent 1st toe donor site defect in a one-stage procedure. METHODS: From 2014 to 2019, finger pulp amputations (13 digits in 12 patients) were reconstructed with free 1st toe pulp flaps, and the donor site was resurfaced by the 2nd toe pedicled flap with the 2nd toe's primary closure. Therapeutic evaluation of repaired fingers and toes was based on cold intolerance, two-point discrimination (2PD), and gait disturbance. RESULTS: All finger and toe pulp flaps survived uneventfully. The average size of free 1st toe and pedicled 2nd toe flap was 3.1 cm × 2.0 cm (3.5 cm × 1.4 cm to 4.2 cm × 2.5 cm) and 3.0 cm × 1.1 cm (2.0 cm × 0.9 cm to 3.8 cm × 1.5 cm), respectively. The regained average static 2PD on the finger and 1st toe pulps was 6 mm (ranged 5-10 mm) and 4 mm (ranged 2-6 mm), respectively. All reconstructed 1st toe pulps were qualified for normal gait. One patient complained the mild cold intolerance, and hammer-toe deformities were involved in two cases. CONCLUSION: To fulfill donor site care and cost-effective rule, the toe-to-finger pulp reconstruction can't underestimate the morbidity on 1st toe donor site due to inappropriate intervention. Equally importantly, the hitchhiking pedicled 2nd toe flap should be recruited in the reconstructive scheme.

Paeoniflorin Suppresses TBHP-Induced Oxidative Stress and Apoptosis in Human Umbilical Vein Endothelial Cells via the Nrf2/HO-1 Signaling Pathway and Improves Skin Flap Survival.

Random-pattern skin flap is a vital technique frequently applied in reconstruction surgeries for its convenience and effectiveness in solving skin defects. However, ischemic necrosis, especially in the distal areas of the flap, still needs extra attention after surgery. Earlier evidence has suggested that paeoniflorin (PF) could stimulate angiogenesis and suppress ischemic cardiovascular disease. However, few studies have focused on the role of PF in flap survival. In this study, we have demonstrated that the human umbilical vein endothelial cells (HUVECs) treated with PF can alleviate tert-butyl hydroperoxide (TBHP)-stimulated cellular dysfunction and apoptosis. To better evaluate, HUVECs' physiology, cell tube formation, migration, and adhesion were assessed. Mechanistically, PF protects HUVECs against apoptosis via stimulating the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway. PF also downregulates mitochondrial ROS production to reduce excessive intracellular ROS production induced by TBHP and restore TBHP-induced mitochondrial depolarization. As a result, silencing Nrf2 partially abolishes the protective effect of PF exposure on HUVECs. In in vivo experiments, the oral administration of PF was shown to have enhanced the vascularization of regenerated tissues and promote flap survival. However, the PF-mediated protection was partially lost after co-treatment with ML385, a selective Nrf2 inhibitor, suggesting that PF is a crucial modulator regulating the Nrf2/HO-1 signaling pathway. In summary, our data have provided a new insight into PF as a potential therapy for enhancing random-pattern flap viability.

Distal Arterialized Venous Supercharging Improves Perfusion and Survival in an Extended Dorsal Three-Perforasome Perforator Flap Rat Model.

BACKGROUND: Perforator flaps are commonly applied for a variety of skin defects. Many strategies (e.g., hyperbaric oxygen and preconditioning) have been investigated to improve flap survival, but a postoperative 2.03 to 18.2 percent flap necrosis frequency remains a major complication. The authors hypothesized that a distal arterialized venous supercharged (DAVS) flap procedure might improve perfusion and survival in an extended three-perforasome perforator flap rat model and rescue flap ischemia intraoperatively. METHODS: One hundred twenty male Sprague-Dawley rats (200 to 300 g) were divided into the thoracodorsal artery (TDA) flap group and the DAVS flap group (n = 60 per group). An approximately 11 × 2.5-cm2 flap based on the TDA perforasome was designed in the TDA flap. A DAVS flap was designed based on the TDA flap and supercharged by anastomosing the rat caudal artery with the deep circumflex iliac vein. At postoperative times 1, 3, 6, and 12 hours and 1, 3, 5, and 7 days, perfusion and angiography were compared. On day 7, flap viability and angiogenesis were assessed using histology and Western blotting. RESULTS: The DAVS flap showed a higher survival rate compared with the TDA flap (100 percent versus 81.93 ± 5.38 percent; p < 0.001). All blood flow ratios of deep circumflex iliac artery to TDA perforasome and of choke zone II to choke zone I were higher in the DAVS flap (all p < 0.05). Angiography qualitatively revealed that choke vessels in choke zone II dilated earlier and extensively in the DAVS flap group. CD34+ vessels (68.66 ± 12.53/mm2 versus 36.82 ± 8.99/mm2; p < 0.001) and vascular endothelial growth factor protein level (0.22 ± 0.03 versus 0.11 ± 0.03; p < 0.001) were significantly increased in the DAVS flap group. CONCLUSIONS: The DAVS procedure improves three-perforasome perforator flap survival and can be used for rescuing flap ischemia intraoperatively. Further study is needed before possible clinical adoption for reconstructive operations.

A metabolic investigation of arterialized venous flaps in rabbits using mass spectrometry-based metabolomics.

An arterialized venous flap (AVF) is an ideal choice of flap to repair wounds. However, the survival of these flaps remains the source of some concern. This study used metabolomic analysis to investigate the mechanisms underlying survival in AVF flaps in order to guide the clinical application of these flaps. Thirty-six male Japanese rabbits were randomly divided into a sham group and an AVF group. They were used for histology and hemodynamic investigations. Three days after surgery, tissue samples were analyzed by mass spectroscopy-based metabolomics. The results of the study revealed a reduction in blood flow, infiltration of inflammatory cells, and necrosis of flaps in the AVF group. In addition, notable changes were evident in the levels of several metabolites in the AVF group, including lactic acid, acetoacetic acid, inositol phosphate, arachidonic acid, and other metabolites. Our results indicate that the AVF group experienced changes in several biological pathways, including energy metabolism, cell membrane stability, and inflammatory response. There is a significant metabolic difference between AVFs and physiological flaps. The dysregulation in certain metabolites may be related to the specific hemodynamics and insufficient energy metabolism of the AVFs.

Ginkgolide B improves multiterritory perforator flap survival by inhibiting endoplasmic reticulum stress and oxidative stress.

BACKGROUND: The therapeutics used to promote perforator flap survival function induces vascular regeneration and inhibit apoptosis. The present study aimed to explore the potential mechanism of the angiogenesis effects of Ginkgolide B (GB) in perforator flaps. Methods: A total of 72 rats were divided into three groups and treated with saline, GB, or GB + tunicamycin (TM; ER stress activator) for seven consecutive days, respectively. Apoptosis was assayed by determining the Bax/Bcl-2 ratio and caspase-3 level. Endoplasmic reticulum (ER) stress markers (CHOP, GRP78, and caspase-12) were detected by Western blot analysis. Oxidative stress was assessed by measuring the superoxide dismutase activity (SOD) and malondialdehyde (MDA), heme oxygenase-1(HO-1), and nuclear factor erythroid-2-related factor 2 (Nrf2) mRNA levels in the flaps. The percentage flap survival area and blood flow were assessed on postoperative day (POD) 7. Angiogenesis was visualized by hematoxylin and eosin and CD34 staining on POD 7. Results: GB increased the survival of perforator flaps, the flap survival area of GB, GB + TM, and control groups was 90.83 ± 1.93%, 70.93 ± 4.13%, and 62.97 ± 6.50%. GB decreased the Bax/Bcl-2 ratio and caspase-3 level. ER stress-related proteins were downregulated by GB. GB also decreased the MDA level and increased SOD activity, HO-1 and Nrf2 mRNA levels in the flaps. Further, GB induced regeneration of vascular vessels in comparison with saline or GB + TM. Conclusions: GB increased angiogenesis and alleviated oxidative stress by inhibiting ER stress, which increased the survival of perforator flaps. In contrast, GB + TM alleviated angiogenesis and induced oxidative stress by activating ER stress and decreasing the survival of perforator flaps.

The Effect of Leonurine on Multiterritory Perforator Flap Survival in Rats.

BACKGROUND: Leonurine (Leo), a natural active compound of Leonurus cardiaca, has been shown to possess various biological activities. However, it is not known whether Leo promotes perforator flap survival. METHODS: In this study, a perforator flap was outlined in the rat dorsum. The rats that survived surgery were divided randomly to control and Leo groups (n = 36 per group). Flap viability, flap perfusion, and level of protein linked with oxidative stress, cell apoptosis, and angiogenesis were evaluated. RESULTS: Relative to control group, the Leo group showed significantly higher the flap survival percentage (70.5% versus 90.2%, P < 0.05) and blood perfusion (197.1 versus 286.3, P < 0.05). Leo also increased 1.8-fold mean vessel density and upregulated 2.1-fold vascular endothelial growth factor protein expression compared with the control group, both of which indicate increased angiogenesis. Moreover, it significantly inhibited apoptosis by lowering caspase-3 activity. Superoxide dismutase expression was remarkably elevated in Leo group compared with the control group (56.0 versus 43.2 U/mg/protein, P < 0.01), but malondialdehyde quantities were significantly lower in the Leo group compared with control group (41.9 versus 57.5 nmol/mg/protein, P < 0.05). CONCLUSIONS: Leo may serve as an effective drug for improving perforator flap survival in rats via antioxidant and antiapoptotic mechanisms and promotion of angiogenesis.

Individual Treatment of Delayed Distal Biceps Tendon Rupture: Case Report and Literature Review.

INTRODUCTION: Complicated elbow injuries (elbow injuries with bone and soft tissue injury) with distal biceps tendon ruptures (DBTRs) are not uncommon. There are several treatment modalities in different situations of injuries. In this article, we reported 3 successful individual treatments of delayed DBTR with complicated elbow injuries. MATERIALS AND METHODS: Three cases of complicated elbow injuries treated between 2010 and 2016 were reviewed. The delayed DBTR cases were summarized and treated. Mayo Elbow Performance Score value, range of motion, and visual analog scale score were used to assess outcomes after a minimum follow-up of 12 months. RESULTS: All 3 patients were male, aged 47 to 54 years (mean, 49.6 years). Patients received surgical treatments. After a mean follow-up of 13.7 months, in cases 1 and 2, Mayo Elbow Performance Score values improved by 50% and 100%, elbow flexion-extension arc were 115 degrees and 110 degrees, pronation-supination arc were 130 degrees and 120 degrees. Arthrodesis case reported pain relief; visual analog scale score for pain was 0 to 1. No postoperative complications were observed, and all patients were satisfied with the results. CONCLUSIONS: Individual treatment is advised in DBTR with complicated elbow injuries. Secondary treatment of DBTR can achieve satisfactory results using individual strategies depending on patients' overall condition.

Debridement arthroplasty of a rare case of elbow stiffness. A case report and literature review.

INTRODUCTION: Elbow stiffness is a common condition that affects the quality of life of patients. Melorheostosis of the elbow associated with elbow stiffness is extremely rare. PRESENTATION OF CASE: We report the case of a 28 yr old male who presented with elbow stiffness which occurred within one year without prior history of trauma or infection. The patient had decrease in range of motion together with progressive worsening pain that forced him to seek medical attention. DISCUSSION: There is no standard treatment for melorheostosis, and management plans must be made on an individual patient basis. The aims of treatment are pain relief and maintaining function. CONCLUSION: Debridement arthroplasty is safe and effective in treating elbow stiffness associated with Melorheostosis.

Routine closure of the donor site with a second dorsal metacarpal artery flap to avoid the use of a skin graft after harvest of a first dorsal metacarpal artery flap.

AIM: Closure of the donor site on the index finger after raising a first dorsal metacarpal artery (DMA) flap harvest is challenging. The conventional choice is to use a full-thickness skin graft. However, this procedure is associated with several complications and a second donor site to harvest the skin graft is inevitable. The aim of this study was to design a modified incision to allow harvest of a first DMA flap without skin graft. METHODS: From 2015 to 2016, 18 patients with a soft tissue defect of the thumb had reconstruction of the defect using a first DMA flap. A modified incision was used and a relaying perforator flap pedicled on the second DMA was raised through the same incision to cover the donor site. Patient satisfaction, appearance of the injured hand, and the active range of motion (ROM) were assessed. The sensitivity was evaluated by the 2-point discrimination (2-PD) test. RESULTS: All flaps survived completely without complications. Good coverage was obtained with only one linear scar in the dorsum of the hand and no skin grafts. All patients recovered full range of movement in their fingers and regained sensitivity of the flaps. All patients were satisfied with their hand function according to the Michigan Hand Outcomes Questionnaire (MHQ). The mean cosmetic score for the appearance of the injured hand was 8.2 out of 10. CONCLUSIONS: Using our modified incision, it was possible to harvest a second DMA flap at the same time as a first DMA flap allowing simultaneous coverage of the donor defect on the index finger. This prevented the need for a skin graft with all of the associated disadvantages.

Role of Homeodomain-Interacting Protein Kinase 2 in the Pathogenesis of Tissue Fibrosis in Keloid-Derived Keratinocytes.

Epithelial-mesenchymal transition (EMT) plays a critical role in fibrotic keloid formation, which is characterized by excessive collagen and extracellular matrix synthesis and deposition. Growing evidence suggests that the serine/threonine kinase homeodomain-interacting protein kinase 2 (HIPK2) acts upstream of several major fibrosis signaling pathways; however, the role of HIPK2 in the keloid fibrogenesis remains unknown. In the current study, we investigated the roles of HIPK2 in the pathogenesis of keloids. Primary normal skin and keloid keratinocytes were cultured and pretreated with transforming growth factor (TGF)-ß1. Next, keratinocytes were transfected with scrambled small interfering RNA (siRNA) and anti-HIPK2 siRNA. The TGF-ß1-associated HIPK2 alterations were investigated by quantitative real-time polymerase chain reaction. Protein levels were analyzed by western blotting. The HIPK2 was markedly increased in the keloid-derived keratinocytes compared with normal skin keratinocytes. In addition, HIPK2 induced the expression of EMT markers in normal skin keratinocytes by TGF-ß1-SMAD family member 3 (SMAD3). The effect of TGF-ß1-related EMT markers and SMAD3 phosphorylation in response to added TGF-ß1 was significantly abrogated when the cells were transfected with HIPK2 siRNA. We conclude that HIPK2 is a crucial factor in the pathogenesis of keloids, suggesting that HIPK2 might be a novel potential drug target for antikeloid therapy.

NADPH oxidase-2 is a key regulator of human dermal fibroblasts: a potential therapeutic strategy for the treatment of skin fibrosis.

The proliferation of human skin dermal fibroblasts (HDFs) is a critical step in skin fibrosis, and transforming growth factor-beta1 (TGF-ß1) exerts pro-oxidant and fibrogenic effects on HDFs. In addition, the oxidative stress system has been implicated in the pathogenesis of skin disease. However, the role of NADPH oxidase as a mediator of TGF-ß1-induced effects in HDFs remains unknown. Thus, our aim was to investigate the role of NADPH in human skin dermal fibroblasts. Primary fibroblasts were cultured and pretreated with various stimulants. Real-time Q-PCR and Western blotting analyses were used for mRNA and protein detection. In addition, siRNA technology was applied for gene knock-down analysis. Hydrogen peroxide production and 2',7'-dichlorofluorescein diacetate (DCFDA) measurement assay were performed. Here, our findings demonstrated that HDFs express key components of non-phagocytic NADPH oxidase mRNA. TGF-ß1 induced NOX2 and reactive oxygen species formation via NADPH oxidase activity. In contrast, NOX3 was barely detectable, and other NOXs did not display significant changes. In addition, TGF-ß1 phosphorylated MAPKs and increased activator protein-1 (AP-1) in a redox-sensitive manner, and NOX2 suppression inhibited baseline and TGF-ß1-mediated stimulation of Smad2 phosphorylation. Moreover, TGF-ß1 stimulated cell proliferation, migration, collagen I and fibronectin expression, and bFGF and PAI-1 secretion: these effects were attenuated by diphenylene iodonium (DPI), an NADPH oxidase inhibitor, and NOX2 siRNA. Importantly, NOX2 siRNA suppresses collagen production in primary keloid dermal fibroblasts. These findings provide the proof of concept for NADPH oxidase as a potential target for the treatment of skin fibrosis.