The contralateral-based submental artery island flap: feasibility and oncological safety in oral cancer-related defect reconstruction.

OBJECTIVES: Oncologic risk is a serious concern of submental artery island flaps. Here, we introduce the contralateral-based submental artery island flap (C-SAIF) and demonstrate its feasibility and long-term oncological safety in reconstructing oral cancer-related defects. METHODS: An anatomical study was performed concentrating on the pedicle length in seven cadavers. Then, a retrospective study was carried out on C-SAIF patients operated on by a single team. The standard surgical technique of C-SAIF was conducted. Outcomes including operative time, length of hospital stay, volume of intraoperative blood loss, and scores of the Multidisciplinary Salivary Gland Society (MSGS) questionnaire were compared with a similar cohort reconstructed with anterolateral thigh free flap (ALTF). In addition, oncological outcomes were evaluated by the 5-year cumulative survival rate between C-SAIF and ALTF patients. RESULTS: The pedicle length of C-SAIF was sufficient for the flap to be extended to the contralateral oral cavity. Fifty-two patients were included in the retrospective study, and nineteen of them underwent reconstruction with C-SAIF. The operative time of C-SAIF was shorter (p = 0.003), and the intraoperative blood loss was less (p = 0.004) than that of ALTF. There was no difference in MSGS scores. The results of survival analysis revealed comparable survival curves for the two groups in terms of overall survival, disease-specific survival, and disease-free survival. CONCLUSION: C-SAIF is a feasible and reliable flap for reconstructing oral cancer-related defects. Moreover, it is an effective island flap to preserve the perforator and pedicle without compromising oncological safety.

MicroRNA-31 mediated by interferon regulatory factor 7 signaling facilitates control of Mycobacterium tuberculosis infection.

Tuberculosis (TB) induced by Mycobacterium tuberculosis (M. tuberculosis) infection remains a global most deadly infectious disease. While development of more effective TB vaccines and therapeutics relies on identifications of true biomarkers designating an immune protection against M. tuberculosis infection, exact protective immune components against M. tuberculosis infection remain largely unidentified. We previously found that severe TB induced remarkable up-regulation of interferon regulatory factor 7 (IRF7) and IRF7-related gene signatures, implicating that some unknown downstream molecules in IRF7 signaling cascades may determine the M. tuberculosis infection outcomes and serve as a protective immune component against M. tuberculosis infection. Indeed, here, we observe that genetic ablation of IRF7 leads to more severe lung pathology, increased M. tuberculosis burdens, impaired differentiation of effector/memory T subsets, and extensively elevated expression of pro-inflammatory cytokines in lungs. Importantly, IRF7 is vital for sustaining expression of PD-1/PD-L1 and PD-1/PD-L1-modulated miRNA-31. Moreover, interventions of miRNA-31 expressions via administration of miRNA-31 agomir reduces lung pathology and bacilli burdens via inducing up-regulation of gene sets involved in biological processes of defense response or cellular and chemical homeostasis in lungs. Thus, this study uncovers previously unrecognized importance and mechanisms of IRF7-mediated miRNA-31 as a protective immune component against M. tuberculosis infection.

Prognostic role of preoperative D-dimer, fibrinogen and platelet levels in patients with oral squamous cell carcinoma.

BACKGROUND: The relationship between cancer and coagulation has been intensively studied in recent years; however, the effects of coagulation factors on oral squamous cell carcinoma (OSCC) have rarely been reported. This study aimed to investigate the relationship between preoperative D-dimer (DD), fibrinogen (FIB), platelets (PLT) and OSCC, as well as the prognostic value of DD, FIB and PLT in OSCC. METHODS: We retrospectively investigated a total of 202 patients with OSCC treated at Guanghua Hospital of Stomatology, Sun Yat-sen University. Baseline demographic and clinicopathological information as well as both preoperative and postoperative DD, FIB and PLT results were collected from each patient, and patients with primary OSCC were followed up for disease progression, death or the end of the study. The correlations between preoperative DD, FIB, PLT and other clinical features, as well as the therapeutic effect and PFS were analysed statistically, and postoperative DD and surgical parameters were also analysed. RESULTS: Preoperative DD was significantly correlated with T stage, N stage, clinical stage and relapse of OSCC (P = 0.000, 0.001, 0.000 and 0.000, respectively). Univariate Cox regression analyses showed that high preoperative DD predicted poor prognosis in patients with OSCC (HR = 2.1, P = 0.033), while FIB and PLT showed no prognostic values. Postoperative DD was significantly correlated with preoperative DD and surgical type but not the duration of surgery (P = 0.005, 0.001 and 0.244, respectively). CONCLUSION: In this study, we suggested that high preoperative DD level may serve as an indicator for synchronous neck dissection in patients with T1, 2 OSCC, and the elevated DD level might be the marker of disease progression in patient follow up.

CA9 transcriptional expression determines prognosis and tumour grade in tongue squamous cell carcinoma patients.

CA9 is a member of the carbonic anhydrases' family, that is often expressed in cancer cells under hypoxic condition. However, the role of CA9 in the molecular mechanisms of tongue squamous cell carcinoma (TSCC) pathogenesis remains unclear. CA9 expression was analysed using the TCGA database, and its influence on survival was performed using Kaplan-Meier, LASSO and COX regression analyses. The correlation between CA9 and immune infiltration was investigated by CIBERSORT and ESTIMATE. Moreover, the relationship between CA9 expression and downstream molecular regulation pathways was analysed by GSEA, GO and WGCNA. CA9 expression correlated with clinical prognosis and tumour grade in TSCC. Moreover, CA9 expression potentially contributes to the regulation of cancer cell differentiation and mediates tumour-associated genes and signalling pathways, including apoptosis, hypoxia, G2M checkpoint, PI3K/AKR/mTOR signalling and TGF-beta signalling pathways. However, the follicular helper T cells, regulatory T cells, immune and stromal scores showed no significance between high and low CA9 expression groups. These findings suggested that CA9 plays a critical role of TSCC prognosis and tumour grade. CA9 expression significantly correlated with the regulation of cell differentiation, various oncogenes and cancer-associated pathways.

Elevated hydrostatic pressure promotes ameloblastoma cell invasion through upregulation of MMP-2 and MMP-9 expression via Wnt/ß-catenin signalling.

BACKGROUND: The process of marsupialization involves the release of intracystic pressure and the fluid contained within. Marsupialization of cystic ameloblastoma is controversial; therefore, we investigated how hydrostatic pressure influences biological behaviours of ameloblastoma cells and its underlying mechanisms. MATERIALS AND METHODS: An ameloblastoma epithelial cell line, hTERT+ -AM, was exposed to different hydrostatic pressures with or without Dickkopf-related protein 1 (also known as DKK), a canonical Wnt signalling pathway inhibitor. A CCK-8 assay, a monolayer wound assay, and a Transwell assay were used to determine cell proliferation, migration and invasion, respectively. qRT-PCR and Western blot were used to detect expression of MMP-2, MMP-9, RANKL and other downstream targets of Wnt signalling. RESULTS: Elevated hydrostatic pressure promoted migration and invasion of ameloblastoma cells, but inhibited proliferation. Expression of MMP-2, MMP-9, LEF-1, cyclin D1, c-Jun and c-Myc was significantly upregulated under elevated hydrostatic pressure, and these effects could be abolished by DKK1. Expression of RANKL, which is thought to be a downstream target of Wnt signalling, did not significantly change under elevated hydrostatic pressure. CONCLUSIONS: This study indicates that elevated hydrostatic pressure promotes the migration and invasion of ameloblastoma cells by activating the Wnt/ß-catenin pathway, thereby increasing expression of MMP-2, MMP-9 and other Wnt signalling downstream targets. This suggests that marsupialization may reduce invasiveness and reverse the bone resorption process by lowering intracystic hydrostatic pressure in cystic ameloblastoma.

Synergistic effects of ischemic preconditioning and immediate post-conditioning in the protection against ischemia/reperfusion injury in rabbit submandibular glands.

Submandibular gland autotransplantation is an effective approach for treating severe keratoconjunctivitis sicca. However, ischemia/reperfusion (I/R) injury, which inevitably occurs during transplantation, is involved in the hypofunction and structural damage that occur early after transplantation. Therefore, it is critical to identify effective strategies to ameliorate I/R injury in submandibular glands. In this study, we investigated the ability of immediate post-conditioning combined with ischemic preconditioning to attenuate I/R injury. We observed that after I/R injury, the level of reactive oxygen species was increased, inflammatory response was strengthened, and severe apoptosis had occurred. In addition, the salivary flow rate was greatly decreased. However, the pathogenesis of I/R injury was significantly ameliorated by ischemia post-conditioning or ischemia preconditioning treatments. In addition, the combination of ischemia preconditioning and post-conditioning achieved synergistic protective effects against I/R injury compared with ischemia preconditioning or ischemia post-conditioning alone. The secretion function was restored in the combination group. Furthermore, the combination treatment involved the same mechanisms of ischemia preconditioning or ischemia post-conditioning, including suppression of the inflammatory reaction and neutrophil accumulation, attenuation of oxidation stress, and inhibition of apoptosis. In conclusion, the combination of ischemia preconditioning and ischemia post-conditioning treatment is a simple and effective approach for treating I/R injury in submandibular glands.

Microvascular Submandibular Gland Transplantation for Severe Keratoconjunctivitis Sicca: A Single-Institution Experience of 61 Grafts.

PURPOSE: Keratoconjunctivitis sicca (KCS) is a relatively common disease that results in discomfort, tear film instability, visual impairment, and ocular surface damage. Artificial tear substitutes may be suitable for the treatment of mild KCS, but no effective treatment currently exists for severe KCS. Therefore, this study evaluated the effectiveness of autologous microvascular submandibular gland transplantation in the treatment of severe KCS. PATIENTS AND METHODS: A total of 61 eyes (56 patients) with severe KCS were treated with autologous submandibular gland transplantation from June 2002 to June 2017. The cephalic vein or the great saphenous vein was applied to solve the problem of unmatched veins. RESULTS: In 53 cases (53 of 56, 94.6%), 58 glands (58 of 61, 95.1%) were transplanted successfully. The mean Schirmer I test value improved from 0.78 ± 0.84 mm preoperatively to 18.83 ± 5.72 mm in the stable period after transplantation. Epiphora (14 of 58, 24.14%) was the most common complication of this procedure. Other postoperative complications included venous thrombosis (6 of 61, 9.84%), local infection (2 of 58, 3.45%), xerostomia (2 of 53, 3.77%), duct fistula (1 of 58, 1.72%), sialolithiasis (1 of 58, 1.72%), and ranula (1 of 58, 1.72%). CONCLUSIONS: Autologous microvascular submandibular gland transplantation is a credible and effective solution for severe KCS.

Neck observation versus elective neck dissection in management of clinical T1/2N0 oral squamous cell carcinoma: a retrospective study of 232 patients.

OBJECTIVE: The management of early-stage (cT1/2N0) oral squamous cell carcinoma (OSCC) remains a controversial issue. The aim of this study was to compare the clinical outcomes of neck observation (OBS) and elective neck dissection (END) in treating patients with cT1/2N0 OSCC. METHODS: A total of 232 patients with cT1/2N0 OSCC were included in this retrospective study. Of these patients, 181 were treated with END and 51 with OBS. The survival curves of 5-year overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) rates were plotted using the Kaplan-Meier method for each group, and compared using the Log-rank test. RESULTS: There was no significant difference in 5-year OS and DSS rates between END and OBS groups (OS: 89.0% vs. 88.2%, P=0.906; DSS: 92.3% vs. 92.2%, P=0.998). However, the END group had a higher 5-year RFS rate than the OBS group (90.1% vs. 76.5%, P=0.009). Patients with occult metastases in OBS group (7/51) had similar 5-year OS rate (57.1% vs. 64.1%, P=0.839) and DSS rate (71.4% vs. 74.4%, P=0.982) to those in END group (39/181). In the regional recurrence patients, the 5-year OS rate (57.1% vs. 11.1%, P=0.011) and DSS rate (71.4% vs. 22.2%, P=0.022) in OBS group (7/51) were higher than those in END group (9/181). CONCLUSIONS: The results indicated that OBS policy could obtain the same 5-year OS and DSS as END. Under close follow-up, OBS policy may be an available treatment option for patients with clinical T1/2N0 OSCC.

Reinnervated nerves contribute to the secretion function and regeneration of denervated submandibular glands in rabbits.

This study aimed to investigate the contribution of redistributed nerves in the secretory function and regeneration of a denervated submandibular gland (SMG). The postganglionic parasympathetic and sympathetic denervated SMGs of rabbits were wrapped in polyester or acellular dermal matrices to block nerve regeneration either partially or completely. Submandibular glands were removed 4, 8, 16, and 24 wk after the operation and examined histologically. Furthermore, the aquaporin-5 (AQP5), muscarinic-3 (M3), and ß1-adrenergic receptors were evaluated by immunofluorescence and western blot analysis. After denervation, salivary flow was decreased and acinar cells were atrophic, and the expression levels of the M3, ß1-adrenergic, and AQP5 receptors were decreased. However, both impaired secretion function and atrophic parenchyma were gradually ameliorated with the growing redistribution of parasympathetic and sympathetic nerves. Apoptosis was markedly inhibited and expression of the M3, ß1-adrenergic, and AQP5 receptors was increased after reinnervation. In contrast, SMGs without reinnervated nerves maintained hyposecretion and atrophic parenchyma. In conclusion, reinnervated nerves in a rabbit's denervated SMG played an important role in the secretion function and regeneration of SMGs via up-regulation of the expression of neurotransmitter receptors and AQP5.

Favorable effects of open surgery on patients with extensive skull base osteoradionecrosis through a personalized sequential approach: A case series.

The present study aimed to investigate outcomes following open surgery for extensive skull base ORN. Open surgery through a personalized sequential approach was employed to deal with five cases of extensive skull base ORN. Two patients with mild cases underwent regional debridement and sequestrectomy, and three patients with severe cases underwent extensive resection with reconstruction using free anterolateral thigh (ALT) flap. Biological glues and vascularized flaps were used for obturation of the skull base bony defect to prevent postoperative cerebrospinal fluid (CSF) leakage. The infections were controlled by antibiotic administrations which strictly followed the principles of antimicrobial stewardship (AMS). As results, both regional debridement plus sequestrectomy and extensive resection achieved satisfied outcomes in all patients. No severe complications and delayed hospitalization occurred. During the follow-up period (8-19 months), all patients were alive, pain free, without crusting or purulent discharge, and no sequestration or CSF leakage occurred. In conclusion, a personalized sequential approach including open surgery, pedicled/vascularized free flap reconstruction and AMS was advocated for patients with extensive skull base ORN.

Functional and esthetic reconstruction of composite lower lip defects with a motor-innervated chimeric facial artery buccinator myomucosal-submental island flap.

OBJECTIVE: This study aimed to assess the functional and esthetic outcomes of a chimeric innervated buccinator myomucosal-submental island flap (BMM-SIF) for large composite lower lip reconstruction. METHODS: This retrospective study included five patients who underwent lower lip tumor resection and BMM-SIF reconstruction at the Hospital of Stomatology, Sun Yat-sen University, between August 2021 and February 2023. Lip function was evaluated using water leakage, cheek puffing tests, and superficial electromyography. Lip appearance was observed using photographs and evaluated through subjective interviews. Donor-site conditions, including facial symmetry and mouth opening, were monitored. RESULTS: All the BMM-SIFs survived. Drooling was the main complication observed shortly after surgery. The water leakage test showed complete oral competence for liquid holding in the 7th month; however, moderate air leakage was present in two patients. Electromyography revealed myoelectric signals from the innervated buccinator at the recipient site. Facial expression and food intake were typically managed. The shape and projection of the vermilion were harmonious and satisfactory for each patient. Neither microstomia nor mouth opening limitation was observed, with an average inter-incisor distance of 37.25±4.4 mm. CONCLUSION: Chimeric motor-innervated BMM-SIF effectively reconstructed large full-thickness lower-lip defects with satisfactory functional and esthetic outcomes.

Contralateral facial artery myomucosal island flap for the reconstruction of T2-T3 oncologic oral defects.

Objectives: To avoid the oncologic risks of ipsilateral regional flaps, this study aimed to explore the feasibility and clinical outcomes of the contralateral-based facial artery myomucosal island flap (C-FAMMIF) for oral T2-T3 oncologic defects reconstruction. Methods: A study of flap anatomy was conducted on 7 cadaver samples and a cohort of 24 patients who received C-FAMMIF reconstruction after malignancy resection were retrospectively researched. A balanced anterolateral thigh flap (ALT) group of 47 patients was extracted as control group using propensity score matching method. Progression-free survival (PFS), functional outcomes, and donor site complications were assessed. Results: Consistent blood supply and drainage through facial artery and vein with median maximum pedicle length of 106 mm supported contralateral reconstruction. The superficial vein drainage pattern indicated safer flap harvest at contralateral neck under circumstances of ipsilateral neck dissections. The pedicle and marginal facial nerve formed three anatomical patterns. The surgical management of each was described. Patients with ipsilateral pN+ neck accounted for 41.7% and 40.4% in the C-FAMMIF and ALT group, respectively. The 2-year PFS rate between the C-FAMMIF and ALT groups was not significantly different (88.2% in C-FAMMIF group and 84.6% in ALT group, respectively, p = 0.6358). Promising recoveries were observed for swallowing function and tactile sensation. The donor sites healed upon primary closure without trismus or permanent facial palsy. Conclusion: Our findings suggested that C-FAMMIF is feasible and safe for T2-T3 oral oncologic defect reconstruction in patients with ipsilateral cN+ neck.

Clinical application of a three-dimensional-printed model in the treatment of intracranial and extracranial communicating tumors: a pilot study.

BACKGROUND: Surgical management for intracranial and extracranial communicating tumors is difficult due to the complex anatomical structures. Therefore, assisting methods are urgently needed. Accordingly, this study aimed to investigate the utility of a three-dimensional (3D)-printed model in the treatment of intracranial and extracranial communicating tumors as well as its applicability in surgical planning and resident education. METHODS: Individualized 3D-printed models were created for eight patients with intracranial and extracranial communicating tumors. Based on these 3D-printed models, a comprehensive surgical plan was made for each patient, after which the patients underwent surgery. The clinicopathological data of patients were collected and retrospectively analyzed to determine surgical outcomes. To examine the educational capability of the 3D-printed models, specialists and resident doctors were invited to review three of these cases and then rate the clinical utility of the models using a questionnaire. RESULTS: The 3D-printed models accurately replicated anatomical structures, including the tumor, surrounding structures, and the skull. Based on these models, customized surgical approaches, including the orbitozygomatic approach and transcervical approach, were designed for the patients. Although parameters such as operation time and blood loss varied among the patients, satisfactory surgical outcomes were achieved, with only one patient developing a postoperative complication. Regarding the educational applicability of the 3D-printed model, the mean agreement for all eight questionnaire items was above six (seven being complete agreement). Moreover, no significant difference was noted in the agreement scores between specialists and residents. CONCLUSION: The results revealed that 3D-printed models have good structural accuracy and are potentially beneficial in developing surgical approaches and educating residents. Further research is needed to test the true applicability of these models in the treatment of intracranial and extracranial communicating tumors.

Understanding the multi-functionality and tissue-specificity of decellularized dental pulp matrix hydrogels for endodontic regeneration.

Dental pulp is the only soft tissue in the tooth which plays a crucial role in maintaining intrinsic multi-functional behaviors of the dentin-pulp complex. Nevertheless, the restoration of fully functional pulps after pulpitis or pulp necrosis, termed endodontic regeneration, remained a major challenge for decades. Therefore, a bioactive and in-situ injectable biomaterial is highly desired for tissue-engineered pulp regeneration. Herein, a decellularized matrix hydrogel derived from porcine dental pulps (pDDPM-G) was prepared and characterized through systematic comparison against the porcine decellularized nerve matrix hydrogel (pDNM-G). The pDDPM-G not only exhibited superior capabilities in facilitating multi-directional differentiation of dental pulp stem cells (DPSCs) during 3D culture, but also promoted regeneration of pulp-like tissues after DPSCs encapsulation and transplantation. Further comparative proteomic and transcriptome analyses revealed the differential compositions and potential mechanisms that endow the pDDPM-G with highly tissue-specific properties. Finally, it was realized that the abundant tenascin C (TNC) in pDDPM served as key factor responsible for the activation of Notch signaling cascades and promoted DPSCs odontoblastic differentiation. Overall, it is believed that pDDPM-G is a sort of multi-functional and tissue-specific hydrogel-based material that holds great promise in endodontic regeneration and clinical translation. STATEMENT OF SIGNIFICANCE: Functional hydrogel-based biomaterials are highly desirable for endodontic regeneration treatments. Decellularized extracellular matrix (dECM) preserves most extracellular matrix components of its native tissue, exhibiting unique advantages in promoting tissue regeneration and functional restoration. In this study, we prepared a porcine dental pulp-derived dECM hydrogel (pDDPM-G), which exhibited superior performance in promoting odontogenesis, angiogenesis, and neurogenesis of the regenerating pulp-like tissue, further showed its tissue-specificity compared to the peripheral nerve-derived dECM hydrogel. In-depth proteomic and transcriptomic analyses revealed that the activation of tenascin C-Notch axis played an important role in facilitating odontogenic regeneration. This biomaterial-based study validated the great potential of the dental pulp-specific pDDPM-G for clinical applications, and provides a springboard for research strategies in ECM-related regenerative medicine.

cGAS-ISG15-RAGE axis reprogram necroptotic microenvironment and promote lymphatic metastasis in head and neck cancer.

BACKGROUND: Cancer cells frequently evolve necroptotic resistance to overcome various survival stress during tumorigenesis. However, we have previously showed that necroptosis is widespread in head and neck squamous cell carcinoma (HNSCC) and contributes to tumor progression and poor survival via DAMPs-induced migration and invasiveness in peri-necroptotic tumor cells. This implicated an alternative strategy that cancers cope with necroptotic stress by reprogramming a pro-invasive necroptotic microenvironment (NME). Here, we aim to decipher how necroptotic cells shape the NME and affect HNSCC progression. METHODS: Both our pre-established cellular necroptotic model and newly established Dox-induce intratumoral necroptosis model were used to investigate how necroptosis affect HNSCC progression. Transcriptomic alterations in peri-necroptotic tumor cells were analyzed by RNA-seq and validated in the NME in mice and patients' samples. The differential DAMPs compositon among apopotosis. Necrosis, and necroptosis were analyzed by label-free proteomic technique, and the necroptosis-specific DAMPs were then identified and validated. The potential receptor for ISG15 were simulated using molecular docking and further validated by in vitro assays. Then the ISG15-RAGE axis was blocked by either knockdown of necroptotic-ISG15 release and RAGE inhibitor FPS-ZM1, and the impact on tumor progression were tested. Last, we further tested our findings in a HNSCC-patients cohort. RESULTS: Necroptosis played a crucial role in driving tumor-cell invasiveness and lymphatic metastasis via tumor-type dependent DAMPs-releasing. Mechanistically, necroptotic DAMPs induced peri-necroptotic EMT via NF-κB and STAT3 signaling. Furthermore, intrinsic orchestration between necroptotic and cGAS-STING signaling resulted in producing a group of interferon stimulated genes (ISGs) as HNSCC-dependent necroptotic DAMPs. Among them, ISG15 played an essential role in reprogramming the NME. We then identified RAGE as a novel receptor for extracellular ISG15. Either blockage of ISG15 release or ISG15-RAGE interaction dramatically impeded necroptosis-driven EMT and lymphatic metastasis in HNSCC. Lastly, clinicopathological analysis showed high ISG15 expression in NME. Extensive necroptosis and high tumor-cell RAGE expression correlated with tumor progression and poor survival of HNSCC patients. CONCLUSIONS: Our data revealed a previously unknown cGAS-ISG15-RAGE dependent reprogramming of the necroptotic microenvironment which converts the necroptotic stress into invasive force to foster HNSCC-cell dissemination. By demonstrating the programmatic production of ISG15 via necroptosis-cGAS orchestration and its downstream signaling through RAGE, we shed light on the unique role of ISG15 in HNSCC progression. Targeting such machineries may hold therapeutic potential for restoring intratumoral survival stress and preventing lymphatic metastasis in HNSCC.

Mandibular reconstruction assisted by preoperative simulation and accurate transferring templates: preliminary report of clinical application.

PURPOSE: This study investigated the application of a computer-aided design and manufacturing technique of defining tumor resection, fibula cutting, and positioning by surgical templates in mandibular reconstructive surgery. MATERIALS AND METHODS: Four patients who required mandibulectomy and simultaneous reconstruction were enrolled in this study. Preoperative surgical simulation was performed. The surgical templates that defined tumor resection, fibula cutting, and positioning were designed and fabricated. RESULTS: The surgeries were performed to the preoperative plan. All flaps survived. Superimposition of the postoperative image and the preoperative plan showed a satisfactory surgical accuracy. CONCLUSIONS: This method of defining tumor resection, fibula cutting, and positioning by surgical templates was accurate enough for mandibular reconstructive surgery.

Injectable decellularized extracellular matrix hydrogel promotes salivary gland regeneration via endogenous stem cell recruitment and suppression of fibrogenesis.

Saliva is key to the maintenance of oral homeostasis. However, several forms of salivary gland (SG) disorders, followed by hyposalivation, often result in dental caries, oral infection, and decreased taste, which dramatically affect the quality of patient's life. Functional biomaterials hold great potential for tissue regeneration in damaged or dysfunctional SGs and maintaining the good health of oral cavity. Herein, we prepared an injectable hydrogel derived from decellularized porcine submandibular glands (pDSG-gel), the material and biological properties of the hydrogel were systematically investigated. First, good biocompatibility and bioactivities of the pDSG-gel were validated in 2D and 3D cultures of primary submandibular gland mesenchymal stem cells (SGMSCs). Especially, the pDSG-gel effectively facilitated SGMSCs migration and recruitment through the activation of PI3K/AKT signaling pathway, suggested by transcriptomic analysis and immunoblotting. Furthermore, proteomic analysis of the pDSG revealed that many extracellular matrix components and secreted factors were preserved, which may contribute to stem cell homing. The recruitment of endogenous SG cells was confirmed in vivo, upon in situ injection of the pDSG-gel into the defective SGs in rats. Acinar and ductal-like structures were evident in the injury sites after pDSG-gel treatment, suggesting the reconstruction of functional SG units. Meanwhile, histological characterizations showed that the administration of the pDSG-gel also significantly suppressed fibrogenesis within the injured SG tissues. Taken together, this tissue-specific hydrogel provides a pro-regenerative microenvironment for endogenous SG regeneration and holds great promise as a powerful and bioactive material for future treatments of SG diseases. STATEMENT OF SIGNIFICANCE: Decellularized extracellular matrix (dECM) has been acknowledged as one of the most promising biomaterials that recapitalizes the microenvironment in native tissues. Hydrogel derived from the dECM allows in situ administration for tissue repair. Herein, a tissue-specific dECM hydrogel derived from porcine salivary glands (pDSG-gel) was successfully prepared and developed for functional reconstruction of defective salivary gland (SG) tissues. The pDSG-gel effectively accelerated endogenous SG stem cells migration and their recruitment for acinar- and ductal-like regeneration, which was attributed to the activation of PI3K/AKT signaling pathway. Additionally, the introduction of the pDSG-gel resulted in highly suppressed fibrogenesis in the defective tissues. These outcomes indicated that the pDSG-gel holds great potential in clinical translation toward SG regeneration through cell-free treatments.

PDPN+ CAFs facilitate the motility of OSCC cells by inhibiting ferroptosis via transferring exosomal lncRNA FTX.

Cancer-associated fibroblasts (CAFs) are abundant and heterogeneous in tumor microenvironment (TME). Cross-talk between cancer cells and CAFs results in cancer progression. Here, we demonstrated that a distinct cancer-associated fibroblasts subset with podoplanin (PDPN) positive expression (PDPN+ CAFs) was correlated with poor survival in oral squamous cell carcinoma (OSCC). PDPN+ CAFs promoted the progression of OSCC by transferring exosomal lncRNA FTX to OSCC cells. Mechanically, FTX bound to flap endonuclease-1 (FEN1), forming an RNA‒protein complex. FTX enhanced promoter demethylation of FEN1 by recruiting ten-eleven translocation-2 (TET2). In addition, FTX/FEN1 axis promoted OSCC cells motility by inhibiting ferroptosis. In xenograft experiments, RSL-3, a ferroptosis-inducing agent, suppressed the tumorigenesis potential of FEN1-overexpressed OSCC cells. Furthermore, Acyl-CoA synthetase long-chain family member 4 (ACSL4) was confirmed to participate in the motility promotion induced by FEN1 overexpression. FEN1 could bind to promoter region of ACSL4 and then inhibit ferroptosis in OSCC cells. Our study reveals that PDPN+ CAFs promote the invasiveness of OSCC cells by inhibiting ferroptosis through FTX/FEN1/ACSL4 signaling cascade. PDPN+ CAFs may serve as a novel potential therapeutic target for OSCC.

Dietary palmitoleic acid reprograms gut microbiota and improves biological therapy against colitis.

Magnitude and diversity of gut microbiota and metabolic systems are critical in shaping human health and diseases, but it remains largely unclear how complex metabolites may selectively regulate gut microbiota and determine health and diseases. Here, we show that failures or compromised effects of anti-TNF-α therapy in inflammatory bowel diseases (IBD) patients were correlated with intestinal dysbacteriosis with more pro-inflammatory bacteria, extensive unresolved inflammation, failed mucosal repairment, and aberrant lipid metabolism, particularly lower levels of palmitoleic acid (POA). Dietary POA repaired gut mucosal barriers, reduced inflammatory cell infiltrations and expressions of TNF-α and IL-6, and improved efficacy of anti-TNF-α therapy in both acute and chronic IBD mouse models. Ex vivo treatment with POA in cultured inflamed colon tissues derived from Crohn's disease (CD) patients reduced pro-inflammatory signaling/cytokines and conferred appreciable tissue repairment. Mechanistically, POA significantly upregulated the transcriptional signatures of cell division and biosynthetic process of Akkermansia muciniphila, selectively increased the growth and abundance of Akkermansia muciniphila in gut microbiota, and further reprogrammed the composition and structures of gut microbiota. Oral transfer of such POA-reprogrammed, but not control, gut microbiota induced better protection against colitis in anti-TNF-α mAb-treated recipient mice, and co-administration of POA with Akkermansia muciniphila showed significant synergistic protections against colitis in mice. Collectively, this work not only reveals the critical importance of POA as a polyfunctional molecular force to shape the magnitude and diversity of gut microbiota and therefore promote the intestinal homeostasis, but also implicates a new potential therapeutic strategy against intestinal or abenteric inflammatory diseases.

Mandible reconstruction assisted by preoperative simulation and transferring templates: cadaveric study of accuracy.

PURPOSE: In this study we tried to define tumor resection, fibula cutting, and positioning by surgical templates to perform the mandible reconstruction surgery according to the preoperative simulation. The accuracy was evaluated through cadaveric surgery. MATERIALS AND METHODS: Five cadaveric mandibles and fibulas were obtained. Preoperative surgical simulation was performed. Surgical templates that defined tumor resection, fibula cutting, and positioning were designed and fabricated. Translation, angular deviation, and rotation of bone grafts, as well as translation of condyles, were measured. RESULTS: The reconstructed mandibles showed high similarity to the surgical planning. The mean translation, angular deviation, and rotation of fibula segments of the reconstructed mandibles were 1.35 ± 0.86 mm, 3.36° ± 1.86°, and 8.13° ± 5.35°, respectively. In the mandible remnants, the translation of condyles was measured, with a mean of 1.39 ± 0.66 mm. CONCLUSIONS: Our method of defining the tumor resection, fibula cutting, and positioning by surgical templates was accurate enough for mandible reconstruction surgery.