Split Anterolateral Thigh Flap: A New Classification of Anatomical Variants and a Surgical Planning Algorithm.

BACKGROUND: Split anterolateral thigh flap is a versatile reconstruction option, yet long underestimated as no practical perforator classification and no optimal strategy were present. Harvesting "capillary nonsizable perforators" could potentially expand flap splits to those with no existing multiple sizable perforators. Concerns over defect characteristics, recipient vessels, pedicle length, and split timing should all be weighted equally in designing the suitable flap. Refinement is thus required to enable precise reconstructions. METHODS: All patients undergoing anterolateral thigh flap harvests between 2014 and 2021 performed by a single surgeon were included. The perforator patterns of sizable pedicle, course, origin, and further successful flap-split methods were documented. Surgical outcome of flap survival was analyzed. RESULTS: Anatomical variants of 134 (48.4%) dual, 123 (44.4%) single, and 20 (7.2%) no sizable perforators were found in a total of 277 anterolateral thigh flaps. The overall flap survival rate was 97.5%. Flap split was performed in 82 flaps, including 29 single and 5 no sizable perforator cases previously considered "unsplittable," by utilizing a series of direct skin paddle split, capillary nonsizable perforators harvesting, and flow-through anastomosis technique. Comparable flap survivals were found between split and nonsplit flaps as well as between split segments supplied by sizable and capillary nonsizable perforators. Primary closure was achieved in 98.9% of the thigh donor sites. CONCLUSION: A new classification of the common anterolateral thigh flap anatomical variants was proposed and a comprehensive algorithm of split flap strategy was developed along with the innovative "fabricate" concept.

Involvement of Aquaporins in the Intense Pulsed Light-Enhanced Wound Healing in Diabetic Rats.

BACKGROUND AND OBJECTIVES: We previously demonstrated that intense pulsed light (IPL) irradiation prior to wounding improved the wound healing in rats with diabetes mellitus (DM). Also, we found that IPL upregulated the expression of aquaporin 3 (AQP3), a protein that is crucial for wound healing, in normal rats. This present study aimed to examine the involvement of AQPs in the IPL-enhanced wound healing in diabetic rats. STUDY DESIGN/MATERIALS AND METHODS: Streptozotocin was used to induce diabetes in Sprague-Dawley rats. Animals were divided into four groups: normal group, DM only group, DM rats with IPL treatment 2 weeks before wounding (DM + IPL-Pre group), and DM rats with concurrent IPL irradiation and wounding (DM + IPL-Con group). Wounds were created on the dorsal skin of rats. The expressions of AQP1, 3, 4, 7, and 9 in the pre-injured skin, periwound, and wound were determined. RESULTS: Among all the AQPs analyzed, only the expressions of AQP3 and AQP7 were significantly altered. Unirradiated diabetic rats showed much higher expression level of AQP3 in the regenerating skin compared with normal rats. IPL pretreatment, but not concurrent treatment, attenuated the expression toward the level detected in the normal wounds. In contrast, a lower expression level of AQP7 was noted in the regenerating skin of DM only rats and IPL pretreatment upregulated the expression to a level similar to that in the normal rats. CONCLUSION: The beneficial effect of IPL pretreatment on the wound healing in diabetic rats might involve a mechanism by which the expression of AQPs is regulated. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Recurrent cervical stitch sinus arising from the deep neck space after thyroidectomy: case study and review.

OBJECTIVE: We describe a one-stage surgical technique for the management of recurrent cervical stitch sinus after thyroidectomy. METHOD: A retrospective, single-centre study of all patients who were operated on because of cervical neck sinus after thyroidectomy. We provide a detailed description of our surgical approach, based on guided sinus removal after prior tract staining with methylene blue and subsequent obliteration using local strap muscle flap. RESULTS: A total of seven patients with a mean age of 46 years were included in the study. All patients had a past history of thyroidectomy because of goitre (n=5) or thyroid cancer (n=2) which had previously been unsuccessfully debrided two or three times. Surgical sinus removal was successful in all cases and no recurrence was observed during the follow-up time. CONCLUSIONS: We conclude that a comprehensive en bloc resection down to the suture granuloma is essential in order to provide surgical cure and prevent recurrence.

Beneficial Effect of Intense Pulsed Light on the Wound Healing in Diabetic Rats.

BACKGROUND AND OBJECTIVE: Wound healing in diabetes mellitus (DM) patients is one of the major health concerns globally. Intense pulsed light (IPL) has been widely used in cosmetic dermatology via mechanisms involving fibroblast stimulation, collagen synthesis, and dermal remodeling, which are events that also occur during the process of wound healing. This present study was aimed to evaluate the possible beneficial effect of IPL on the wound healing in diabetic rats. MATERIALS AND METHODS: Diabetes was induced in Sprague-Dawley rats using streptozotocin. The rats were randomly divided into four groups: normal group, DM only group, DM rats with IPL treatment 2 weeks before wounding (DM + IPL-Pre group), and DM rats with concurrent IPL exposure and wounding (DM + IPL-Con group). The wounds were created on the dorsal skin of rats. Wound closure rate, collagen deposition, and angiogenesis were assessed. RESULTS: There were no significant differences in the wound closure rate and mean time to wound closure between IPL-treated diabetic rats and normal rats. By contrast, delayed wound closure and prolonged mean time to wound closure were both noticed in DM only group. Enhanced collagen deposition and angiogenesis were observed in IPL-Pre, but not IPL-Con diabetic rats, as compared with untreated DM rats. CONCLUSION: Results of this study may provide novel insight into future preventive strategies using IPL for the management of wounds in diabetic patients. Lasers Surg Med. © 2019 Wiley Periodicals, Inc.

Experience on primary closure of fibular flap donor sites and development of an algorithm for closure based on different flap designs.

BACKGROUND: Most skin paddles of the fibula flap are harvested from the distal third of the lower leg, skin grafting for the donor-site is necessary. METHODS: A retrospective review was done on patients with large bony defects using free fibula osteocutaneous flaps (FOSCFF) for head and neck reconstruction. We focus on the techniques for closure of donor sites were skin grafting, primary closure with tear drop design and propeller flap technique on the donor site closure using skin graft, primary closure and local propeller flap based on the different location of perforators of FOSCFF. Postoperative follow up include incidence of wound complications, postoperative days to ambulation and cosmetic outcome. RESULTS: A total of 48 patients were included. Twenty five patients had skin graft (Group A), and 23 patients had primary closure (Group B); in 16 patients tear-drop design was used, 6 had propeller flap, and the remaining 1 patient received a chimeric flap. Group A had more wound complication rates compared to Group B; 20% versus 4.3%, respectively (p = .19). The average postoperative days to ambulation for Group A were 15.1 days versus 7.3 days for Group B (p < .001). The cosmetic score in the B group (2.71) versus A group (4.89) was also statistically significant (p = .007). All the patients ambulated well at follow up. CONCLUSION: Primary closure using the tear drop technique and propeller flap is superior to skin grafting in terms of better cosmetic appearance, earlier postoperative ambulation, and no need for another donor site for skin graft.

Versatility of the Free Anterolateral Thigh Flap in the Reconstruction of Large Defects of the Weight-Bearing Foot: A Single-Center Experience with 20 Consecutive Cases.

Background Reconstruction of the weight-bearing surface of the foot represents a challenging task. With very little scope to borrow glabrous tissue from adjacent areas means that achieving a "like for like" reconstruction is rarely possible. In this setting, alternative approaches need to be considered. In this article we present our experience with various differing designs of the anterolateral thigh flap (ALT) in the reconstruction of 20 large defects of the weight-bearing sole. Methods Twenty patients with complex soft tissue defects of the weight-bearing sole underwent reconstruction over a 5-year period. Five cases were complicated by osteomyelitis resulting in significant calcaneal defects. The follow-up period ranged from 8 to 48 months and outcomes were assessed by two-point discrimination and protective sensation, observation of gait, and the ability of the patient to return to wearing normal footwear. Results All flaps survived with the exception of two partial skin necrosis. Sensory nerve coaptation was performed in 12/20 cases. One patient underwent second-stage total calcaneal reconstruction with a fibula osteocutaneous flap. Five large defects were reconstructed with the split skin paddle technique to allow for direct donor-site closure. No evidence of postoperative ulceration was noted in any of the patients over the follow-up period and all were satisfied regarding the functional and aesthetic results achieved. Conclusion Complex defects of the weight-bearing sole can be successfully reconstructed using the free ALT flap resulting in very favorable functional outcomes. Even when calcaneal osteomyelitis has set in, excellent outcomes can be achieved.

Altered exosomal protein expression in the serum of NF-κB knockout mice following skeletal muscle ischemia-reperfusion injury.

BACKGROUND: The NF-κB signaling pathway plays a role in local and remote tissue damage following ischemia-reperfusion (I/R) injury to skeletal muscles. Evidence suggests that exosomes can act as intercellular communicators by transporting active proteins to remote cells and may play a role in regulating inflammatory processes. This study aimed to profile the exosomal protein expression in the serum of NF-κB knockout mice following skeletal muscle ischemia-reperfusion injury. RESULTS: To investigate the potential changes in protein expression mediated by NF-κB in secreted exosomes in the serum following I/R injury, the levels of circulating exosomal proteomes in C57BL/6 and NF-κB(-/-) mice were compared using two dimensional differential in-gel electrophoresis (2-DE), liquid chromatography tandem mass spectrometry (LC-MS/MS), and proteomic analysis. In C57BL/6 mice, the levels of circulating exosomal proteins, including complement component C3 prepropeptide, PK-120 precursor, alpha-amylase one precursor, beta-enolase isoform 1, and adenylosuccinate synthetase isozyme 1, increased following I/R injury. However, in the NF-κB(-/-) mice, the expression of the following was upregulated in the exosomes: protease, serine 1; glyceraldehyde-3-phosphate dehydrogenase-like isoform 1; glyceraldehyde-3-phosphate dehydrogenase; and pregnancy zone protein. In contrast, the expression of apolipoprotein B, complement component C3 prepropeptide, and immunoglobulin kappa light chain variable region was downregulated in NF-κB(-/-) mice. Bioinformatic annotation using the Protein Analysis Through Evolutionary Relationships (PANTHER) database revealed that the expression of the exosomal proteins that participate in metabolic processes and in biological regulation was lower in NF-κB(-/-) mice than in C57BL/6 mice, whereas the expression of proteins that participate in the response to stimuli, in cellular processes, and in the immune system was higher. CONCLUSIONS: The data presented in this study suggest that NF-κB might regulate exosomal protein expression at a remote site via circulation following I/R injury.

Effect of intense pulsed light on the expression of aquaporin 3 in rat skin.

Intense pulsed light (IPL) technology has been popularly employed in clinical treatments for dermatological and cosmetic purposes in recent years; yet, the underlying mechanisms of its functions are not fully elucidated. On the other hand, aquaporin (AQP) 3, a member of a subgroup of the aquaporin family that transports both water and small solutes, such as glycerol, has been documented to play an important role in the skin homeostasis. We thus examined the possible involvement of AQP3 in the functional mechanisms of IPL irradiation. Rat dorsal skin areas were irradiated one to three times with IPL at doses of 15, 25, and 35 J/cm2. Skin specimens were collected 7 days after the final irradiation and analyzed for changes in histology, skin hydration, mRNA, and protein expressions of AQP3. IPL induced no significant variations in the mRNA expression levels. Twice or thrice irradiation at the dose of 25 or 35 J/cm2 significantly enhanced AQP3 protein expression. Immunofluorescence study revealed that AQP3 was mainly localized to keratinocyte membranes in the basal layer of epidermis, and the localization was unaltered by IPL. In addition, the pattern of IPL-induced changes in skin hydration was generally coincided with the expression profile of AQP3. These results suggest the possibility that one of the functional mechanisms of IPL might be related to the regulation of AQP3 protein expression.

The "in situ molding technique: " an accurate and simple way to fix resorbable plates to the facial skeleton.

Bioabsorbable plates developed for use in the facial skeleton have become an integral part of the craniomaxillofacial surgeon's reconstructive armamentarium. They avoid the problems associated with the retention of metal plates and can be easily contoured when heated in a thermobath. The technical process of molding and securing these devices, often through small access incisions, to achieve rigid fixation of facial fractures can be difficult. In this article, we describe a simple, novel technique that we have developed, using hot water suction irrigation, to achieve in situ molding of resorbable plates during facial fracture fixation. We used this technique to fix 123 facial fractures in 110 patients over a 4-year period. No complications secondary to the use of hot water suction irrigation were encountered.

Microsurgical reconstruction for head and neck cancer in elderly patients.

The purpose of this study is to review our group of elderly patients and examine whether microsurgical reconstruction is safe to perform in these cases. From October 2006 to October 2009, 747 patients with head and neck cancer who underwent free flap reconstruction were divided into two groups: patients younger than 70 years (n = 714) and patients older than 70 years (n = 33). The two groups of patients were compared regarding medical comorbidities, medical/surgical complications, smoke, and alcohol consumption and outcomes. Two deaths occurred in the "elderly" (6% mortality rate) group of patients and two deaths in the "young" group of patients (0.28% mortality rate) in the immediate postoperative period (15 days postoperatively). Thus, mortality rate had a significant difference (p = 0.011) between these two groups. There was no significant difference in morbidity between these two groups of patients regarding the rate of medical complications, surgical complications, flap failure, and reexploration during our 3-month follow-up period. Mortality risk is higher in the elderly group of patients. However, there is no significant difference regarding the free flap success rate between these two groups. Thorough preoperative evaluation and preparation are critical to achieve a favorable outcome in elderly patients.

Pushing the Limits of Reach for the Pedicled Anterolateral Thigh Flap.

The pedicled anterolateral thigh flap, although tremendously versatile, may be limited in reach, especially in challenging clinical cases. Traditional methods to extend its reach may remain insufficient or unavailable. We describe two modifications to the conventional pedicled flap to extend its reach to the limits, namely (1) selecting a distal perforator supplemented by the nonsizeable perforator harvest technique, and (2) the double-pivot technique adding an additional rotation to the flap à la propeller perforator flap. The increased reach not only improves reconstructive success, but also opens up new applications for this workhorse flap.

Use of anteromedial thigh flaps as an alternative to anterolateral thigh flaps for reconstruction of head and neck defects in cancer patients.

BACKGROUND: To determine whether anteromedial thigh (AMT) flaps are a good choice for reconstruction in cases in which no sizable skin perforator is found in anterolateral thigh (ALT) flap dissection or ALT flaps have been previously harvested. METHODS: From February 2006 to August 2008, 17 free AMT flaps were used to reconstruct soft tissue defects of the head and neck. We recorded the age and sex of the patients, sites of primary tumor, tumor stage, size of defect, previous operative conditions, results of flap transfer, and donor-site complications. RESULTS: Of the 17 AMT flaps, 1 flap failed and 1 showed partial necrosis. Venous insufficiency developed in 2 cases, and the flaps were successfully salvaged in both the cases. The success rate was 94.1%. The AMT flaps were 6 to 20 cm long and 4 to 9 cm wide. The mean length of the pedicle was 7.5 ± 1.0 cm (range, 5-12 cm). Of the 17 donor sites, 6 were closed directly, 9 were closed using split-thickness skin grafts, and 2 were closed using full-thickness skin grafts. Complications and morbidity of the donor site were minimal. CONCLUSIONS: Cases in which no sizable perforator is found or an ALT flap has been previously harvested pose an aesthetic challenge, and an AMT flap is a good alternative for performing successful reconstruction in such cases.

A successful free fibula transfer in the patient with chronic peroneal vein thrombosis.

Despite the rare incidence, occult chronic thrombosis of peroneal veins of the fibula graft during the flap harvest presents a challenge to produce a successful reconstruction. In this article, we present a case of a 54-year-old man with chronic thrombosis of peroneal veins found during the harvest of the free fibula osteocutaneous flap for reconstruction of the mandible defect after tumor ablation. With near-total obliteration of the lumens, a small lumen with residual blood outflow was identified under microscopic magnification. A successful flap transfer was made possible by using the recanalized lumen around the chronic thrombus of the vein for microanastomosis. The pathological analysis of the vein revealed that the recanalized lumens and the endothelial cells-specific CD31 immunohistochemical stain highlighted the endothelium of regenerative lumen around the chronic thrombus. The abundant deposition of thick collagen fibers also suggested a chronic nature of the thrombus. However, although a successful microsurgical free osteocutaneous flap transfer might be possible in the patient with lower-limb chronic peroneal vein thrombosis, a careful preoperative evaluation with imaging study is recommended for high-risk patients.

A review of pharyngocutaneous fistula management in head and neck malignancies.

Pharyngocutaneous fistula is a serious complication after head and neck reconstruction and concurrent chemoradiotherapy, yet no consensus or practical protocols regarding the surgical timing and specific procedures could be found in the current literature. The authors aimed to review their clinical experience in surgical management and develop an algorithmic approach accordingly. A retrospective review of all hypopharyngeal cancer patients who developed pharyngocutaneous fistula during 2017 to 2021 at E-Da Hospital was conducted. Seventeen patients developed pharyngocutaneous fistula in all 321 pharyngeal cancer admissions during this period. Three patients received interventions at acute stage (≤2 weeks), with two direct repairs Three patients received interventions at acute stage (≤2 weeks), with two direct repairs and one regional flap coverage then negative pressure wound therapy. Nine received interventions at subacute stages (2 weeks to 3 months), with 4 resolved after debridement and direct repair yet another 4 underwent regional flap reconstruction and 1 free flap reconstruction. Five chronic fistula (>3 months) received secondary reconstructions utilizing a double-layered repair of local turn-over flaps for the internal mucosal opening and another flap harvest (four regional flaps and one free flap) to cover the outer skin defect. All patients after the palliative surgery achieved complete remission of fistula at follow follow-up. Different conservative and surgical approaches should be adopted according to the acute, subacute, and chronic stages of pharyngocutaneous fistula after palliative head and neck reconstructions.

Intraoperative Enteral Nutrition Feeding in Free-Flap Healing after Reconstruction Surgery for Head and Neck Cancers.

OBJECTIVE: To investigate the beneficial outcomes of intraoperative enteral feeding in free-flap regeneration after extended head and neck cancer resection and flap reconstruction surgery. STUDY DESIGN: A pilot randomized, double-blind, placebo-controlled clinical trial. SETTING: Single tertiary care center. METHODS: Patients with advanced head and neck cancers requiring radical tumor resections and free-flap reconstruction were randomly assigned to receive intraoperative enteral nutrition feeding (100 kcal/100 mL at 10-20 mL/h) via a nasogastric tube during free-flap reconstruction (n = 28) or continue fasting (n = 28). The primary outcome was impaired free-flap regeneration that required surgical reintervention within 90 days after the operation. Participants were enrolled between April 2020 and January 2022; the 90-day follow-up ended in April 2022. RESULTS: The incidence of total or partial flap failure was similar between the 2 groups (14.2% or n = 4 in each group), but the rate of wound dehiscence or edge necrosis was significantly reduced in the feeding group (n = 6 vs 0 for fasting vs feeding; absolute risk reduction, 25.0% [95% confidence interval, 6.9-43.0]%; p = 0.022). Hospital stay length was shorter (p = 0.042) and hand grip strength was better preserved (p = 0.025) in the feeding group. Plasma concentrations of interleukin (IL)-6 and IL-8 after the operation increased significantly more in the fasting group. Perioperative adverse events did not differ between the 2 groups. CONCLUSION: Perioperative enteral feeding is a simple, safe, and effective approach to improve perioperative systemic catabolism and proinflammatory reactions, thereby enhancing early wound regeneration after major operations.

Simultaneous reconstruction of head and neck defects following tumor resection and trismus release with a single anterolateral thigh donor site utilizing a lateral approach to flap harvest.

BACKGROUND: An anterolateral thigh (ALT) flap has gradually become the workhorse flap of reconstructions at different anatomical locations because of its reliability and versatility. In this study, we introduced the concepts: one is the ALT flap harvest from a lateral approach and the other is the reconstruction of extensive head and neck defects with a single ALT donor site. METHODS: A lateral approach ALT flap was harvested in 13 patients who had buccal cancer and/or tumors of the lower lip combined with buccal trismus. Three types of ALT flaps (type I: two skin paddles, one pedicle; type II: two skin paddles, two pedicles; type III: one skin paddle, one pedicle) were used in one-stage reconstructions of these extensive head and neck defects. RESULTS: In our series, there were four type I, five type II, and four type III flaps. All flaps survived and no major postoperative complication occurred. Four of the 13 donor sites were repaired with a split-thickness skin graft harvested from the contralateral thigh. The immediate interincisor distance increase was 21.4 and 16.5 mm at 1-year follow-up. CONCLUSIONS: Different types of ALT flap from a single donor site can be designed by means of a lateral approach; and the satisfactory results of reconstruction for extensive head and neck defects following the tumor resection and trismus release can be achieved.

Plantar forefoot reconstruction: A proposal of a management algorithm based on a case series analysis: Plantar forefoot reconstruction.

BACKGROUND: Several loco-regional flaps have been described for plantar forefoot coverage. We, herein, report our single-centre experience in plantar forefoot reconstruction and propose a decision-making process based on the defect's size. METHODS: This is a retrospective case series study of all patients who underwent plantar forefoot reconstruction in a 10-year period. We propose a treatment algorithm, based on the defect size. Defects are classified into small, moderate and large. Small defects (<10cm2) can be covered with the hemi-pulp toe flap. Patients with moderate defects (10-25cm2) can be treated with the reverse medial plantar artery flap (MPAF) from the instep area. For large defects (>25cm2), we recommend regional flaps, that is the distally based sural flap (DBSF) from the ipsilateral calf, or free flaps, such as the anterolateral thigh flap (ALT) or the skin-grafted gracilis flap. RESULTS: The data of 51 patients were collected and analysed. The median age was 58 years (range 19-84). Nine patients had small defects and underwent hemi-pulp toe flap reconstruction. Three patients presented with moderate defects that were covered with reverse MPFs. The vast majority of the patients (39 patients) had large defects. Of these, eight cases were treated with DBSF and 31 cases with free flaps. Free flap transfers were successful in 97% of the cases. Overall complication rate was 25%. CONCLUSION: We conclude that local flaps should be preferred in plantar forefoot reconstruction as they provide like-tissue for small to moderate defects, for large defects regional flaps or free flaps were indicated. A defect-based approach can facilitate the decision-making process.

Simvastatin induces heme oxygenase-1 expression but fails to reduce inflammation in the capsule surrounding a silicone shell implant in rats.

BACKGROUND: Statins are lipid-lowering agents that are widely used in medical practice. Some studies have demonstrated that statins reduce proinflammatory signaling and have antioxidant and anti-inflammatory effects. The inducible heme oxygenase-1 (HO-1) catalyzes the stepwise degradation of heme to produce equimolar quantities of biliverdin, iron, and carbon monoxide; it has also been suggested to promote the important cholesterol-independent cytoprotective action of statins against oxidative insults. However, overexpression of HO-1 may have dual effects under oxidative stress, and the overaccumulation of ferric iron from heme may result in detrimental rather than cytoprotective effects. This study was designed to investigate the effect of a specific statin, simvastatin, and the role of HO-1 on the inflammatory status of the capsule surrounding a silicone shell implant in rats. METHODS: Sprague-Dawley rats were randomly assigned to different groups according to the indicated implantation time (1 , 2 wk, 1 , 2 , and 3 mo postimplant) and the presence or absence of additional treatment (2 mg/kg oral simvastatin daily and/or 2 mg/kg HO inhibitor zinc protoporphyrin (ZnPP) by intraperitoneal injection daily). The formed de novo capsular tissue around the silicone implant was dissected away at the indicated time of sacrifice for experiments regarding the HO-1 expression and the inflammatory status. RESULTS: We found a biphasic pattern of inflammation of the capsule with increased production of TNF-α, IL-1ß, and COX-2, and activation of NF-κB at 1 wk and again at 1 mo postimplantation. Numerous CD68+monocytes or macrophages were diffusely distributed in the capsule in the early stage but not in the late stage postimplantation. In addition, the implantation procedure induced HO-1 expression, which was significantly up-regulated in the first 2 wk but decreased after 1 mo. Although daily feeding of the rats with simvastatin at 2 mg/kg induced HO-1 expression in the capsule throughout the experimental period, simvastatin treatment failed to reduce the production of TNF-α, IL-1ß, and COX-2, or limit NF-κB activation in the early or late stages after implantation. Additionally, simvastatin treatment did not decrease the amount of CD68+cells distributed in the capsule at 1 wk postimplantation. HO-1 up-regulation by simvastatin treatment or down-regulation by additional injection of ZnPP did not demonstrate significant correlation with the inflammatory status of the capsule. CONCLUSION: Simvastatin failed to reduce inflammation of the capsule surrounding a silicone shell implant. Although simvastatin induced HO-1 expression throughout the experimental time, up-regulated HO-1 expression could not be attributed to the inflammatory status of the capsule.

Identification of the potential target genes of microRNA-146a induced by PMA treatment in human microvascular endothelial cells.

Phorbol 12-myristate 13-acetate (PMA) is known to activate protein kinase C (PKC) and increase angiogenesis in cultured endothelial cells. Using a microRNA (miRNA) array, we found that PMA induced miR-146a expression in human microvascular endothelial cells. The miR-146a expression was dependent on dose and time and independent of PKC activation. Using a combined approach involving predictions using miRanda algorithm and whole genome microarray experiments with or without inhibition of miR-146a expression by LNA-antimir-146a or LNA-control, 29 potential target genes of miR-146a were identified. Because endothelial cell S phase progression is an early event in the induction of angiogenesis, we evaluated 5 cell cycle-related genes from the 29 target genes and found that the transcripts of 3 genes (CCNA2, PA2G4, and BRCA1) were downregulated after PMA treatment, but their expression was rescued upon miR-146a inhibition. However, inhibition of miR-146a expression failed to alter the cell cycle distribution or angiogenesis induced by PMA treatment. By using a combined approach involving computational prediction and a whole genome microarray experiment in the presence or absence of antimir, the observations in this presented article raise the possibility that antimir strategies might be used to identify the potential miRNA targets.

Altered expression of the microRNAS and their potential target genes in the soleus muscle after peripheral denervation and reinnervation in rats.

BACKGROUND: To profile the expression of microRNAs (miRNAs) and their potential target genes in the soleus muscles after denervation and reinnervation of the sciatic nerve in rats. MATERIALS AND METHODS: The 4 months denervated and reinnervated soleus muscles were analyzed with Agilent Rat miRNA array to detect the expressed miRNAs against those from the sham control. These differentially expressed miRNAs were applied for hierarchical cluster analysis using average linkage and Pearson correlation as a measure of similarity. A combined approach using computational prediction by the miRanda algorithm and the Agilent Whole Rat Genome 4× 44K oligo microarray experiment was performed to identify the potential target genes of these up-regulated miRNAs. Gene ontology (GO) analysis of these potential target genes into one of the three ontologies, biological process, molecular function, or cellular component, was performed and compared between the denervated and reinnervated muscles. RESULTS: Thirty-six and 39 miRNAs of 350 rat miRNAs tested were significantly up-regulated in the denervated and reinnervated muscles, respectively. The expressed miRNAs in these two groups were similar but with different folds, and the unsupervised hierarchy clustering was able to separate the samples into denervation and reinnervation groupings. In the GO analysis, all three categories indicated a considerable reduced number of the potential target genes of the up-regulated miRNAs and less fraction of differentially expressed genes in most of the GO terms in the reinnervated muscle. CONCLUSIONS: This study demonstrated a different involvement of miRNAs and their potential target genes in the soleus muscle after denervation and after reinnervation of the sciatic nerve in a rat model.