Bone Marrow Mesenchymal Stem Cells-Derived Exosomes Promote Survival of Random Flaps in Rats through NRF2-Mediated Antioxidative Stress.

BACKGROUND: Random flaps are the most used defect repair method for head and neck tumors and trauma plastic surgery. The distal part of the flap often undergoes oxidative stress (OS), ultimately leading to flap necrosis. Stem cells exosomes exhibit potential effects related to anti-inflammatory, regenerative, and antioxidant properties. Nuclear factor erythroid-2-related factor 2 (Nrf2) is an important factor in regulating oxidative balance. Exosomes have been reported to monitor its transcription to alleviate OS. This study examined the impacts and underlying mechanisms of antioxidant actions of exosomes derived from bone marrow mesenchymal stem cells (BMSCs-Exo) on random flaps. METHODS: BMSCs-Exo was injected into the tail veins of rats on days 0, 1, and 2 after surgery of random flaps. The rats were euthanized on day 3 to calculate the survival rate. Immunohistochemical staining, western blotting, dihydroethidium probe, superoxide dismutase, and malondialdehyde assay kits were used to detect OS level. Human umbilical vein endothelial cells were co-cultured with BMSCs-Exo and ML385 (an inhibitor of Nrf2) in vitro. RESULTS: BMSCs-Exo may significantly improve the survival rate of the random flaps by reducing apoptosis, inflammation, and OS while increasing angiogenesis. Besides, BMSCs-Exo can also increase mitochondrial membrane potential and reduce reactive oxygen species levels in vitro. These therapeutic effects might stem from the activation of the Keap1/Nrf2 signaling pathway. CONCLUSION: BMSCs-Exo improved the tissue antioxidant capacity by regulating the keap1/Nrf2 signaling pathway. BMSCs-Exo may be a new strategy to solve the problem of random flap necrosis.

Comprehensive complication index: A new reporting standard for postoperative complications of free-flap reconstruction in head and neck cancer patients.

OBJECTIVE: We aimed to validate and evaluate the comprehensive complication index (CCI) as a measure of postoperative complications (POCs) in the patients with head and neck squamous cell carcinoma (HNSCC) who had undergone free-flap reconstruction. STUDY DESIGN: A single-center, prospective cohort study was conducted on the patients with primary HNSCC treated between 2015 and 2020. RESULTS: Of 443 patients, 177 experienced POCs (40.0%). According to the new CCI, 93 patients had severe POCs (score ≥26.2; 21.0%), and only 76 patients were classified as having severe POCs (grade ≥III; 17.2%) according to the traditional Clavien-Dindo classification (CDC). The patients with CCI scores ≥26.2 had a higher rate of major adverse short-term outcomes, such as prolonged length of the hospital stay after surgery, excessive medical costs, and the need for transfusion. Importantly, the Kaplan-Meier analysis revealed a lower overall survival rate for patients with severe complications (CCI score ≥26.2, P = .038). However, no statistically significant differences were observed between CDC grades III or above and overall survival (P = .100). CONCLUSIONS: The CCI can be used to evaluate POCs of free-flap reconstruction in patients with HNSCC. It performed more accurately than the CDC in short- and long-term outcome prediction and risk factor identification.

Exosomes Derived from Bone Marrow Mesenchymal Stem Cells Alleviate Ischemia-Reperfusion Injury and Promote Survival of Skin Flaps in Rats.

Free tissue flap transplantation is a classic and important method for the clinical repair of tissue defects. However, ischemia-reperfusion (IR) injury can affect the success rate of skin flap transplantation. We used a free abdomen flap rat model to explore the protective effects of exosomes derived from bone marrow mesenchymal stem cells (BMSCs-exosomes) against the IR injury of the skin flap. Exosomes were injected through the tail vein and the flaps were observed and obtained on day 7. We observed that BMSCs-exosomes significantly reduced the necrotic lesions of the skin flap. Furthermore, BMSCs-exosomes relieved oxidative stress and reduced the levels of inflammatory factors. Apoptosis was evaluated via the terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay and Western blot analysis of Bax, Bcl-2. Simultaneously, BMSCs-exosomes promoted the formation of new blood vessels in the IR flap, as confirmed by the increased expression level of VEGFA and the fluorescence co-staining of CD31 and PCNA. Additionally, BMSCs-exosomes considerably increased proliferation and migration of human umbilical vein endothelial cells and promoted angiogenesis in vitro. BMSCs-exosomes could be a promising cell-free therapeutic candidate to reduce IR injury and promote the survival of skin flaps.

Spindle and kinetochore-associated complex 3 promotes cell growth via the PI3K/AKT/GSK3ß and PI3K/AKT/FOXO1 pathways and is a potential prognostic biomarker for oral squamous cell carcinoma.

OBJECTIVE: This study elucidated the clinical significance, functions, and mechanism of action of spindle and kinetochore-associated complex 3 (SKA3) in oral squamous cell carcinoma (OSCC). STUDY DESIGN: The SKA3 levels within the patients with OSCC were determined using the The cancer genome atlas (TCGA) database and clinical samples. The functions of SKA3 in OSCC cells were evaluated by cell counting Kit-8 (Beyotime Biotechnology, Haimen, China), 5-ethynyl-2'-deoxyuridine, wound healing, transwell invasion, flow cytometry, and xenograft nude mice model assays. A quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot were performed to assess mRNA and protein expression levels in specimens and cells, respectively. RESULTS: The SKA3 was highly expressed in OSCC tissues, and its knockdown suppressed OSCC cell proliferation, migration, and invasion, and promoted their apoptosis. Mechanistically, SKA3 was shown to modulate OSCC cell proliferation and apoptosis via the PI3K/AKT/GSK3ß and PI3K/AKT/FOXO1 pathways. CONCLUSIONS: Biologically, SKA3 has a potential carcinogenic role in OSCC progression and is a promising prognostic biomarker and therapeutic target.

Postoperative Complications of Free Flap Reconstruction in Moderate-Advanced Head and Neck Squamous Cell Carcinoma: A Prospective Cohort Study Based on Real-World Data.

Background: Postoperative complications (POCs) of moderate-advanced head and neck squamous cell carcinoma (HNSCC) after free flap reconstruction have received little attention. We investigated the risk factors that lead to POCs and their impact on management and prognosis. Patients and Methods: A single-center, prospective cohort study was conducted at Beijing Stomatological Hospital on primary HNSCC patients treated between 2015 and 2020. Results: In total, 399 consecutive HNSCC patients who underwent radical resection of the primary tumor and free flap reconstruction were enrolled in this study, 155(38.8%) experienced POCs. The occurrence of POCs directly led to worse short-term outcomes and poorer long-term overall survival (P=0.0056). Weight loss before the operation (P=0.097), Tumor site (P=0.002), stage T4b (P=0.016), an ACE-27 index of 2-3 (P=0.040), operation time≥8h (P=0.001) and Clindamycin as antibiotic prophylaxis (P=0.001) were significantly associated with POCs. Conclusions: The occurrence of POCs significantly leads to worse short-term outcomes and increases the patients' burden.

Knowledge of Chinese dentists on HPV, their willingness and barriers to recommend HPV vaccination to patients.

Objective: This study aimed to assess the knowledge of Chinese dentists on human papilloma virus (HPV), their willingness and factors prevention them from recommending patients for HPV vaccination, and to identify ways through which dentists can acquire HPV-related knowledge.Methods: This was a cross-sectional study based on Chinese dentists. The anonymous self-filled questionnaire method was used to collect demographic information of participants, their knowledge of HPV, willingness and barriers to recommending HPV vaccines to patients, and the strategies they can adopt to obtain HPV-related knowledge.Results: A total of 517 dentists completed the questionnaire, and 89.94% of dentists were willing to recommend HPV vaccination to patients. Participants aged 30-39 years, male dentists and dentist-in-charge had relatively lower knowledge scores than other groups. Besides, participants aged 30-39 years, working in private hospitals, and practicing in Southern China had a lower willingness to recommend HPV vaccination to patients. Recommending HPV vaccination to patients is not within the scope of practicing dentists, and concerns about the safety of the HPV vaccine were found to be the main barriers preventing its recommendation. Notably, 97.87% of dentists were eager to acquire HPV-related knowledge, and agreed for the first time to enroll in relevant educational courses.Conclusion: Chinese dentists had expressed a strong desire to recommend HPV vaccines to patients, even though their knowledge of HPV was scanty. Therefore, measures to improve their understanding of HPV vaccines and eliminate barriers suppressing their willingness to recommend HPV vaccines are urgently needed.

Assessment of the function of SUB6 in the pathogenic dermatophyte Trichophyton mentagrophytes.

Trichophyton mentagrophytes is a keratinophilic pathogenic fungus that infects both humans and animals. Subtilisins are important for T. mentagrophytes virulence, particularly when invading the epidermal barrier of the host. Subtilisin gene SUB6 belongs to a seven-member gene family (SUB1-SUB7) encoding the subtilisin serine proteases. Additionally, the SUB6 gene product Sub6, which is thought to be the major allergen Tri r2 in Trichophyton rubrum, elicits both immediate- and delayed-type hypersensitivity (DTH) reactions in humans. To assess its gene function, SUB6 was disrupted using the Agrobacterium tumefaciens-mediated transformation method. Polymerase chain reaction and Southern blot analyses were used to confirm the disruption. In vitro virulence analyses comparing the mutant with the wild-type strain showed that proteolytic activity was significantly increased in the SUB6 gene disruption strain (SUB6::hph), which corresponded to the significantly increase in MEP4 (metalloprotease gene) and SUB3 expression of SUB6::hph. The SUB6::hph -infected animals showed attenuated clinical symptoms and pathological changes, and because of the persistently high level of immunosuppressive cytokine IL-10, the increase in DTH-related cytokines IFN-γ, TNF-α and IL-12 was delayed and lower than that in animals infected with the wild-type strain. These results suggested that SUB6::hph had attenuated virulence in vivo, and that a genetically-linked regulatory effect may account for the increase in proteolytic activity and the residual pathogenicity of the mutant strain.