Proanthocyanidins Ameliorate LPS-Inhibited Osteogenesis of PDLSCs by Restoring Lysine Lactylation.

Periodontitis is a bacteria-induced inflammatory disease characterized by the progressive destruction of periodontal supporting tissues. Periodontal ligament stem cells (PDLSCs) are capable of differentiating into osteoblasts, which is an important stem cell source for endogenous periodontal tissue regeneration. Lysine lactylation (Kla) is a novel post-translational modification of proteins that is recently thought to be associated with osteogenic differentiation. Here, we found that lactylation levels are reduced both in the periodontal tissue of rats with periodontitis and lipopolysaccharide (LPS)-stimulated human PDLSCs. Proanthocyanidins were able to promote the osteogenesis of inflamed PDLSCs by restoring lactylation levels. Mechanistically, proanthocyanidins increased lactate production and restored the lactylation levels of PDLSCs, which recovered osteogenesis of inflamed PDLSCs via the Wnt/ß-catenin pathway. These results provide evidence on how epigenetic regulation by pharmacological agents influence the osteogenic phenotype of stem cells and the process of periodontal tissue repair. Our current study highlights the valuable potential of natural product proanthocyanidins in the regenerative engineering of periodontal tissues.

Proanthocyanidin enhances the endogenous regeneration of alveolar bone by elevating the autophagy of PDLSCs.

OBJECTIVE: This study aimed to investigate the effect of proanthocyanidin (PA) on osteogenesis mediated by periodontal ligament stem cells (PDLSCs) and endogenous alveolar bone regeneration. BACKGROUND: Leveraging the osteogenic potential of resident stem cells is a promising strategy for alveolar bone regeneration. PA has been reported to be effective in osteogenesis. However, the effect and mechanism of PA on the osteogenic differentiation of PDLSCs remain elusive. METHODS: Human PDLSCs were treated with various doses of PA to assess the cell proliferation using Cell Counting Kit-8. The osteogenic differentiation ability was detected by qRT-PCR analysis, western blot analysis, Alizarin red S staining, and Alkaline Phosphatase staining. The level of autophagy was evaluated by confocal laser scanning microscopy, transmission electron microscopy, and western blot analysis. RNA sequencing was utilized to screen the potential signaling pathway. The alveolar bone defect model of rats was created to observe endogenous bone regeneration. RESULTS: PA activated intracellular autophagy in PDLSCs, resulting in enhanced osteogenic differentiation. Moreover, this effect could be abolished by the autophagy inhibitor 3-Methyladenine. Mechanistically, the PI3K/Akt/mTOR pathway was negatively correlated with PA-mediated autophagy activation. Lastly, PA promoted the alveolar bone regeneration in vivo, and this effect was reversed when the autophagy process was blocked. CONCLUSION: PA may activate autophagy by inhibiting PI3K/Akt/mTOR signaling pathway to promote the osteogenesis of PDLSCs and enhance endogenous alveolar bone regeneration.

Self-help inflatable balloon versus autologous skin-grafting surgery for preventing esophageal stricture after complete circular endoscopic submucosal dissection: a propensity score matching analysis.

BACKGROUND: The self-help inflatable balloon (SHIB) and autologous skin-grafting surgery (ASGS) were used to prevent stricture after esophageal complete circular endoscopic submucosal dissection (cESD) with promising clinical results. We aim to evaluate which method is more suitable for patients who underwent esophageal cESD. METHODS: From October 2017 to July 2021, patients whose mucosal defect length were between 30 and 100 mm after esophageal cESD were retrospectively reviewed from two prospective studies. They were enrolled once SHIB or ASGS was used as preventive methods to prevent stricture. Propensity score matching (PSM) was used to balance the baseline characteristics between the two groups. Comparisons were made between the two groups, including operation time, the longitudinal length of ulceration, fasting time, hospitalization days, and the incidence of stricture. RESULTS: A total of 41 patients who met the inclusion criteria were enrolled in the study. The numbers of patients in SHIB group and ASGS group were 25 and 16, respectively. Fifteen patients in each group were selected after performing PSM. The basic baseline characteristics were comparable between the two groups. The stricture rates were 20% (3/15) in SHIB group and 40% (6/15) in ASGS group, while the difference was not statistically significant (p = 0.427). The SHIB group showed significantly shorter operation time, shorter hospitalization days, lower cost, and longer removing balloon/stent time compared with ASGS group (p < 0.001). Comparison of relevant stricture factors between the stricture group and non-stricture group revealed that longer longitudinal length of ulceration (> 60 mm) accounted for a higher proportion in stricture groups (p = 0.035). CONCLUSION: Both the SHIB and ASGS had high efficacy and safety in preventing strictures in patients with mucosal defects no longer than 100 mm in length after esophageal cESD. The longitudinal length of ulceration > 60 mm was the independent factor for predicting stricture.

NDGA enhances the physicochemical and anti-biodegradation performance of dentin collagen.

OBJECTIVES: Collagen fibrils from carious dentin matrix are prone to enzymatic degradation. This study investigates the feasibility and mechanism of nordihydroguaiaretic acid (NDGA), as a collagen crosslinker, to bio-modify the demineralized dentin matrix. METHODS: The physicochemical properties of the crosslinked dentin matrix were characterized by swelling ratio, ninhydrin assay, Fourier Transform Infrared spectroscopy, and atomic force microscopy. The collagenase degradation resistance was evaluated by measuring loss of dry mass, hydroproline release, loss of elasticity, and micro-nano structure integrity. The cytotoxicity of NDGA-crosslinked dentin collagen was evaluated by flow cytometry. RESULTS: NDGA crosslinked dentin matrix without destroying the integrity of collagen. Mechanistically, NDGA formed bisquinone bond between two adjacent o-quinone groups, resulting in NDGA polymeric matrix in which collagen fibrils were embedded. NDGA modification could significantly enhance the stiffness of dentin matrix at macro-nano scale. The NDGA-crosslinked dentin matrix exhibited remarkably low collagen degradation and sustained bulk elasticity after collagenase challenge, which were attributed to decreased water content, physical masking of collagenase bind sites on collagen, and improved stiffness of collagen fibrils. Notably, NDGA-crosslinked dentin matrix exhibited excellent biocompatibility. CONCLUSION: NDGA, as a biocompatible collagen crosslinker, improves the mechanical properties and biodegradation resistance of demineralized dentin matrix.

Long-term outcomes of peroral endoscopic myotomy for Chicago classification type I vs type III achalasia in treatment-naive patients.

The efficacy of peroral endoscopic myotomy (POEM) for achalasia has potential associations with Chicago classification by high-resolution manometry (HRM). Type II achalasia demonstrates the best response to POEM of all subtypes, while there remain controversies between type I and type III. Moreover, previous treatment history might cause discrepancy in direct comparison. We aimed to compare the clinical outcome of POEM for type I vs type III in treatment-naive patients. In total, 82 patients with type I or type III achalasia (45 type I, 37 type III) from February 2015 to December 2018 were enrolled and POEM was carried out as the initial treatment. Clinical success, change of Eckardt scores and HRM parameters were analyzed and compared between type I and type III group. About, 43 (95.6%) patients and 34 (91.9%) patients in type I and type III group acquired the clinical success (P = 0.821). Eckardt score and HRM results after POEM treatment decreased significantly in either group (P<0.01). Compared to type III group, higher reduction rates of Eckardt score (type I vs type III, 78.6 vs 66.9%, P = 0.034) and basal LES pressure (type I vs type III, 58.9 vs 40.4%, P = 0.040) were observed in type I group. Type I achalasia patients showed better response to POEM with more favorable clinical remission in Eckardt score and HRM outcomes than type III.

THBS1-Mediated Degradation of Collagen via the PI3K/AKT Pathway Facilitates the Metastasis and Poor Prognosis of OSCC.

Oral squamous cell carcinoma (OSCC) is a prevalent form of malignant tumor, characterized by a persistently high incidence and mortality rate. The extracellular matrix (ECM) plays a crucial role in the initiation, progression, and diverse biological behaviors of OSCC, facilitated by mechanisms such as providing structural support, promoting cell migration and invasion, regulating cell morphology, and modulating signal transduction. This study investigated the involvement of ECM-related genes, particularly THBS1, in the prognosis and cellular behavior of OSCC. The analysis of ECM-related gene data from OSCC samples identified 165 differentially expressed genes forming two clusters with distinct prognostic outcomes. Seventeen ECM-related genes showed a significant correlation with survival. Experimental methods were employed to demonstrate the impact of THBS1 on proliferation, migration, invasion, and ECM degradation in OSCC cells. A risk-prediction model utilizing four differentially prognostic genes demonstrated significant predictive value in overall survival. THBS1 exhibited enrichment of the PI3K/AKT pathway, indicating its potential role in modulating OSCC. In conclusion, this study observed and verified that ECM-related genes, particularly THBS1, have the potential to influence the prognosis, biological behavior, and immunotherapy of OSCC. These findings hold significant implications for enhancing survival outcomes and providing guidance for precise treatment of OSCC.

Hybrid endoscopic submucosal dissection: An alternative resection modality for large laterally spreading tumors in the cecum?

BACKGROUND: Endoscopic resection for large, laterally spreading tumors (LSTs) in the cecum is challenging. Here we report on the clinical outcomes of hybrid endoscopic submucosal dissection (ESD) in large cecal LSTs. METHODS: We retrospectively reviewed data from patients with cecal LSTs ≥ 2 cm who underwent ESD or hybrid ESD procedures between January of 2008 and June of 2019. We compared the baseline characteristics and clinical outcomes, including procedure time, the en bloc and complete resection rates, and adverse events. RESULTS: A total of 62 patients were enrolled in the study. There were 27 patients in the ESD group and 35 patients in the hybrid ESD group, respectively. Hybrid ESD was more used for lesions with submucosal fibrosis. No other significant differences were found in patient characteristics between the two groups. The hybrid ESD group had a significantly shorter procedure time compared with the ESD group (27.60 ± 17.21 vs. 52.63 ± 44.202 min, P = 0.001). The en bloc resection rate (77.1% vs. 81.5%, P = 0.677) and complete resection rate (71.4% vs. 81.5%, P = 0.359) of hybrid ESD were relatively lower than that of the ESD group in despite of no significant difference was found. The perforation and post-procedure bleeding rate (2.9% vs. 3.7%, P = 0.684) were similar between the two groups. One patient perforated during the ESD procedure, which was surgically treated. One patient in the hybrid ESD group experienced post-procedure bleeding, which was successfully treated with endoscopic hemostasis. Post-procedural fever and abdominal pain occurred in six patients in the ESD group and five patients in the hybrid ESD group. One patient in the ESD group experienced recurrence, which was endoscopically resected. CONCLUSION: The results of this study indicate that hybrid ESD may be an alternative resection strategy for large cecal LSTs with submucosal fibrosis.

Utility of radial incision and cutting with steroid injection for refractory stricture after endoscopic submucosal dissection for large superficial esophageal squamous cell carcinoma.

BACKGROUND AND AIMS: Endoscopic submucosal dissection (ESD) for superficial esophagus squamous cell carcinoma (SESCC) may cause esophageal stricture and related dysphagia symptoms, especially when the lesion is widespread. Endoscopic balloon dilation (EBD) is the prior choice to treat post-ESD stricture. However, certain patients show poor response to EBD treatment and frequent dilations are required. We perform radial incision and cutting combined with intralesional steroid injection to manage refractory stricture. The study aims to evaluate the safety and efficacy of this new combined treatment. METHODS: From October 2017 to February 2019, 25 patients who accepted repeated EBD because of refractory stricture after extensive ESD for large SESCC were enrolled. Radial incision and cutting followed by local steroid injection was performed on all the patients, and therapeutic EBD was conducted to treat recurring stricture after combined treatment. The incidence of recurrent stricture, clinical outcome of combined treatment, and following therapeutic EBD, procedure-related adverse events were assessed and analyzed. RESULTS: During the follow-ups, the incidence of recurrent esophageal strictures was 92%. Combined treatment reduced the severity of stenosis and lowered the corresponding dysphagia scores significantly, compared with previous EBD. Mean symptom-relief duration of EBD was prolonged significantly from 29.9 to 76.0 days. Perforation was observed in one patient during operation and successfully sealed with metal clips. CONCLUSIONS: Combination of radial incision and cutting with steroid injection is a safe and feasible treatment for esophageal refractory stricture after extensive ESD, appearing to improve the therapeutic EBD outcome and maintain a longer symptom-relief duration.

Experience with Esophageal Granular Cell Tumors: Clinical and Endoscopic Analysis of 22 Cases.

BACKGROUND: Esophageal granular cell tumors (GCTs) are rare tumors. Differences in reports on the clinical features of GCTs in the esophagus and some controversies about the diagnostic strategy for esophageal GCTs exist. OBJECTIVES: We aimed to investigate the clinical features and diagnosis of esophageal GCTs. Additionally, we sought to determine the prevalence of gastroesophageal reflux disease and reflux esophagitis in patients with esophageal GCTs. METHODS: We retrospectively studied the clinical features, endoscopic features, and management of 22 patients with esophageal GCTs. RESULTS: Esophageal GCTs were more common in men than in women with a ratio of 1.2:1 and were predominantly found in the distal esophagus. Ten patients with esophageal GCTs had regurgitation and/or heartburn symptoms, and eight patients were confirmed to have reflux esophagitis by endoscopy. All esophageal GCTs were protuberant lesions covered by normal esophageal epithelium. The endoscopic morphology of esophageal GCTs was diverse. On endoscopic ultrasonography, these tumors appeared as homogeneous or inhomogeneous hypoechoic lesions with clear borders originating from the submucosal or mucosal layer. Eleven patients underwent endoscopic forceps biopsy at the first endoscopy, and only six patients were correctly diagnosed by pathology. Nevertheless, the 18 lesions treated with endoscopic resection were all correctly diagnosed without complications, and no patients developed recurrence during the follow-up period. CONCLUSIONS: The occurrence of esophageal GCTs may be related to esophageal inflammation. As a method for obtaining an accurate pathological diagnosis and for treatment, endoscopic resection should be offered as the primary option for patients with esophageal GCTs.

Advanced achalasia: good candidate for peroral endoscopic myotomy.

Peroral endoscopic myotomy (POEM) has been increasingly accepted as the first-line treatment of achalasia. However, laparoscopic Heller myotomy or esophagectomy still remains as the mainstay treatment for advanced achalasia featured with megaesophagus and/or sigmoid-shaped esophagus. Although the efficacy of POEM for advanced achalasia with sigmoid-shaped esophagus has been described, little is known about the role of POEM for patients with megaesophagus. The aim of our study is to evaluate the efficacy and safety of POEM for advanced achalasia with megaesophagus. Patients who received initial examinations and underwent POEM in our hospital from June 2013 to December 2018 were identified and data were retrospectively analyzed. The advanced achalasia was defined as megaesophagus with a diameter of ≥6 cm. The primary outcome was clinical success. The secondary outcomes were technical success and adverse events. A total of 112 patients (50 females, 44.6%) were included with a mean age of 44.8 years. The median symptom duration was 6.5 years (IQR:3.0-13.0 years). Modified POEM techniques were used in 27.7% (31/112) of patients. Technical success rate was 99.1% (112/113) per procedure. Clinical success was seen in 93.1% patients with median Eckardt score decreasing from 8.0 to 1.0 (P < 0.001) during a median 31.0 months of follow-up. The mean LES pressure decreased from 29.5 mmHg to 14.2 mmHg after POEM (P < 0.05). Procedure-related adverse events occurred in 8.9% patients. Reflux disease was observed postoperatively in 26.7% of patients. POEM is also indicated for patients with advanced achalasia with a favorable safety and efficacy.

The outcomes of modified endoscopic mucosal resection and endoscopic submucosal dissection for the treatment of rectal neuroendocrine tumors and the value of endoscopic morphology classification in endoscopic resection.

BACKGROUND: To compare the outcomes of modified endoscopic mucosal resection (m-EMR) and endoscopic submucosal dissection (ESD) for rectal neuroendocrine tumors (NETs) and evaluate the value of endoscopic morphology classification in endoscopic resection (ER). METHODS: Patients with rectal NET diameters less than 2 cm who were treated between April 2007 and January 2019 were enrolled. The endoscopic morphology of rectal NETs was classified based on the endoscopic views. Patients who underwent ESD and m-EMR were compared. Baseline characteristics as well as en bloc resection, complete resection, the procedure time, adverse events and the risk factors associated with incomplete resection were analyzed. RESULTS: A total of 429 patients with 449 rectal NETs were enrolled for the classification of endoscopic morphology and were classified into four types (Ia, IIb, II, and III). There were 79 patients in the m-EMR group and 259 patients in the ESD group before matching. Propensity score matching created 77 pairs between the two groups that were well balanced. The mean procedure time was significantly shorter for m-EMR than for ESD (9.1 ± 4.4 min vs 16.0 ± 7.9 min, P = 0.000). The rates of en bloc resection (98.7% vs 100%; P = 1.000), complete resection (90.9% vs 93.5%, P = 0.548) and adverse events (2.6% vs 2.6%, P = 1.000) were similar between the two groups. Univariate and multivariate analyses showed that histopathological grade and endoscopic morphology were associated with incomplete resection. CONCLUSION: Both ESD and m-EMR are effective and safe for the treatment of rectal NETs. Endoscopic morphology should be considered along with histopathological grade for ER.

Autologous Skin-Grafting Surgery to Prevent Esophageal Stenosis After Complete Circular Endoscopic Submucosal Tunnel Dissection for Superficial Esophageal Neoplasms.

OBJECTIVES: To assess the safety and effectiveness of autologous skin-grafting surgery (ASGS) for preventing esophageal stenosis after complete circular endoscopic submucosal tunnel dissection (ccESTD) for superficial esophageal neoplasms. METHODS: Between October 2017 and March 2018, 8 patients who underwent ccESTD and ASGS were included. We assessed the occurrence of esophageal stenosis and adverse events. RESULTS: No adverse events occurred, including perforation, bleeding, wound infection, or stent migration. Five patients did not experience stenosis over a median follow-up of 7 months. CONCLUSIONS: ASGS appeared to be a safe and effective way to prevent esophageal stenosis after ccESTD.

Clinical experience of using a novel self-help inflatable balloon to prevent esophageal stricture after circumferential endoscopic submucosal dissection.

Although endoscopic submucosal dissection (ESD) is gradually becoming a first-line treatment for superficial esophageal neoplasms (SEN), strictures occur in almost 100% of cases after circumferential ESD. A standard method to prevent stricture has not been established. Thus, we propose a novel self-help inflatable balloon to prevent stricture. The new balloon was used by the patients themselves at home (4-5 times a day, duration of each procedure was approximately 15-20 min), and was removed when the defects were almost healed. From January 2018 to September 2018, eight patients who received circumferential ESD for SEN and underwent a novel self-help inflatable balloon to prevent stricture were enrolled. Median size of the mucosal defects was 76.3 mm (range: 50-90 mm). Median time for removing the self-help inflatable balloon was 94.6 days (range, 71-119 days). Only one (12.5%) patient experienced stricture, and three endoscopic balloon dilation sessions were carried out for this patient. All patients tolerated the balloon well, and none experienced perforation or delayed bleeding. The self-help inflatable balloon seems to show a high preventive effect against stricture in patients whose mucosal defect was no longer than 100 mm in length after esophageal circumferential ESD. This method is economic, feasible, and safe.

Controlled release of manganese and magnesium ions by microsphere-encapsulated hydrogel enhances cancer immunotherapy.

Despite the considerable potential of immune checkpoint blockade (ICB) therapy in treating various cancer types, it faces several challenges, of which the constrained objective response rate and relatively short duration of response observed in patients with cancer are the most important. This study introduces an injectable temperature-sensitive hydrogel, Pluronic F-127 (PF-127)@MnCl2/ alginate microspheres (ALG-MS)@MgCl2, that enhances the therapeutic efficacy of programmed cell death-ligand 1 (PD-L1) in cancer cells. The hydrogel material used in this study facilitated the rapid release of a significant amount of manganese ions (Mn2+) and the gradual and sustained release of magnesium ions (Mg2+) within the tumor microenvironment. This staged release profile promotes an immune microenvironment conducive to the cytotoxicity of CD8+ T cells and natural killer cells, thereby enhancing the efficacy of ICB therapy. Furthermore, the PF-127@MnCl2/ALG-MS@MgCl2 composite hydrogel exhibits the ability to convert drug-resistant tumor ("cold tumor") with a low PD-L1 response to a "hot tumor" with a high PD-L1 response. In summary, the PF-127@MnCl2/ALG-MS@MgCl2 hydrogel manipulates the immune microenvironment through the precise discharge of Mg2+ and Mn2+, thus, augmenting the efficacy of ICB therapy.

Transcriptome analysis suggests broad jejunal alterations in Linghu's obesity-diarrhea syndrome: A pilot study.

BACKGROUND: Obesity is associated with a significantly increased risk for chronic diarrhea, which has been proposed as Linghu's obesity-diarrhea syndrome (ODS); however, its molecular mechanisms are largely unknown. AIM: To reveal the transcriptomic changes in the jejunum involved in ODS. METHODS: In a cohort of 6 ODS patients (JOD group), 6 obese people without diarrhea (JO group), and 6 healthy controls (JC group), high-throughput sequencing and bioinformatics analyses were performed to identify jejunal mucosal mRNA expression alterations and dysfunctional biological processes. In another cohort of 16 ODS patients (SOD group), 16 obese people without diarrhea (SO group), and 16 healthy controls (SC group), serum diamine oxidase (DAO) and D-lactate (D-LA) concentrations were detected to assess changes in intestinal barrier function. RESULTS: The gene expression profiles of jejunal mucosa in the JO and JC groups were similar, with only 1 differentially expressed gene (DEG). The gene expression profile of the JOD group was significantly changed, with 411 DEGs compared with the JO group and 211 DEGs compared with the JC group, 129 of which overlapped. The enrichment analysis of these DEGs showed that the biological processes such as digestion, absorption, and transport of nutrients (especially lipids) tended to be up-regulated in the JOD group, while the biological processes such as rRNA processing, mitochondrial translation, antimicrobial humoral response, DNA replication, and DNA repair tended to be down-regulated in the JOD group. Eight DEGs (CDT1, NHP2, EXOSC5, EPN3, NME1, REG3A, PLA2G2A, and PRSS2) may play a key regulatory role in the pathological process of ODS, and their expression levels were significantly decreased in ODS patients (P < 0.001). In the second cohort, compared with healthy controls, the levels of serum intestinal barrier function markers (DAO and D-LA) were significantly increased in all obese individuals (P < 0.01), but were higher in the SOD group than in the SO group (P < 0.001). CONCLUSION: Compared with healthy controls and obese individuals without diarrhea, patients with Linghu's ODS had extensive transcriptomic changes in the jejunal mucosa, likely affecting intestinal barrier function and thus contributing to the obesity and chronic diarrhea phenotypes.

Prevalence of chronic diarrhea and its association with obesity in a Chinese community-based population.

BACKGROUND: Epidemiological data on chronic diarrhea in the Chinese population are lacking, and the association between obesity and chronic diarrhea in East Asian populations remains inconclusive. This study aimed to investigate the prevalence of chronic diarrhea and its association with obesity in a representative community-dwelling Chinese population. METHODS: This cross-sectional study was based on a multistage, randomized cluster sampling involving 3503 residents aged 20-69 years from representative urban and rural communities in Beijing. Chronic diarrhea was assessed using the Bristol Stool Form Scale (BSFS), and obesity was determined based on body mass index (BMI). Logistic regression analysis and restricted cubic splines were used to evaluate the relationship between obesity and chronic diarrhea. RESULTS: The standardized prevalence of chronic diarrhea in the study population was 12.88%. The average BMI was 24.67 kg/m 2 . Of all the participants, 35.17% (1232/3503) of participants were classified as overweight and 16.13% (565/3503) as obese. After adjustment for potential confounders, individuals with obesity had an increased risk of chronic diarrhea as compared to normal weight individuals (odds ratio = 1.58, 95% confidence interval: 1.20-2.06). A nonlinear association between BMI and the risk of chronic diarrhea was observed in community residents of males and the overall participant group ( P  = 0.026 and 0.017, respectively). CONCLUSIONS: This study presents initial findings on the prevalence of chronic diarrhea among residents of Chinese communities while offering substantiated evidence regarding the significant association between obesity and chronic diarrhea. These findings offer a novel perspective on gastrointestinal health management.

Identification and affinity enhancement of T-cell receptor targeting a KRASG12V cancer neoantigen.

Neoantigens derived from somatic mutations in Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS), the most frequently mutated oncogene, represent promising targets for cancer immunotherapy. Recent research highlights the potential role of human leukocyte antigen (HLA) allele A*11:01 in presenting these altered KRAS variants to the immune system. In this study, we successfully generate and identify murine T-cell receptors (TCRs) that specifically recognize KRAS8-16G12V from three predicted high affinity peptides. By determining the structure of the tumor-specific 4TCR2 bound to KRASG12V-HLA-A*11:01, we conduct structure-based design to create and evaluate TCR variants with markedly enhanced affinity, up to 15.8-fold. This high-affinity TCR mutant, which involved only two amino acid substitutions, display minimal conformational alterations while maintaining a high degree of specificity for the KRASG12V peptide. Our research unveils the molecular mechanisms governing TCR recognition towards KRASG12V neoantigen and yields a range of affinity-enhanced TCR mutants with significant potential for immunotherapy strategies targeting tumors harboring the KRASG12V mutation.

WDR76 regulates 5-fluorouracil sensitivity in colon cancer via HRAS.

BACKGROUND: WD repeat domain 76 (WDR76) has been reported in multiple tumors, while without relation to chemotherapy resistance. 5-fluorouracil (5-FU) is widely adopted in treating colon cancer. However, the resistance of WDR76 and 5-FU in colon cancer remains unclear. METHODS: Limma package in R software was employed to analyze the differentially expressed genes. Western blot or quantitative real-time PCR (qRT-PCR) were run to assessed the gene expression. The cytotoxic effect was determined according to cell viability assay, colony formation assay in vitro. Cell apoptosis was assayed using flow cytometry. GSEA analysis was performed to identify pathways related to the target gene. Xenografted mice model was employed to evaluate the tumor growth. RESULTS: Bioinformatic analysis revealed the higher expression of WDR76 in 5-FU sensitive colon cancer cells compared to resistant colon cancer cells, accompanied by the decreased mRNA expression of WDR76 in 5-FU resistant colon cancer cells. The overexpressed WDR76 resulted in the apoptosis and the downregulated colony numbers in 5-FU resistant colon cancer cells, leading to the elevated sensitivity of 5-FU. Meanwhile, knockdown of WDR76 enhances the resistance of 5-FU in colon cancer both in vitro and vivo, which was reversed by a specific inhibitor of HRAS, Kobe006. An important molecular mechanism of 5-FU resistance lies the degradation of HRAS induced by WDR76. CONCLUSION: Our findings demonstrated a role of WDR76 as a promising target for reversing the resistance of colon cancer to 5-FU.

Effects of the Combined Application of Trimethylated Chitosan and Carbodiimide on the Biostability and Antibacterial Activity of Dentin Collagen Matrix.

The structural integrity of a dentin matrix that has been demineralized by the clinical use of etchants or calcium-depleting endodontic irrigants, such as endodontic ethylenediaminetetraacetic acid (EDTA), is often deteriorated due to the collagenolytic activities of reactivated endogenous enzymes as well as the infiltration of extrinsic bacteria. Therefore, the biomodification of dentin collagen with improved stability and antibacterial activity holds great promise in conservative dentistry. The purpose of this study was to evaluate the effects of the combined application of trimethylated chitosan (TMC) and 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) on the biostability and antibacterial activity of the demineralized dentin collagen matrix. The morphological changes in the collagen matrix were observed by scanning electron microscopy (SEM), the amount of TMC adsorbed on the collagen surface was detected by X-ray photoelectron spectroscopy, and the elastic modulus was measured by a three-point bending device. Dry weight loss and amino acid release were detected to evaluate its anti-collagenase degradation performance. The antibacterial performance was detected by confocal microscopy. The TMC-treated group had less collagen space and a more compact collagen arrangement, while the untreated group had a looser collagen arrangement. The combined application of TMC and EDC can increase the elastic modulus, reduce the loss of elastic modulus, and result in good antibacterial performance. The current study proved that a dentin collagen matrix biomodified by TMC and EDC showed improved biodegradation resistance and antibacterial activities.

Quercetin as an Auxiliary Endodontic Irrigant for Root Canal Treatment: Anti-Biofilm and Dentin Collagen-Stabilizing Effects In Vitro.

Bacterial reinfection and root fracture are the main culprits related to root canal treatment failure. This study aimed to assess the utility of quercetin solution as an adjunctive endodontic irrigant that does not weaken root canal dentin with commitment anti-biofilm activity and bio-safety. Based on a noninvasive dentin infection model, dentin tubules infected with Enterococcus faecalis (E. faecalis) were irrigated with sterile water (control group), and 0, 1, 2, 4 wt% quercetin-containing ethanol solutions. Live and dead bacteria percentages in E. faecalis biofilms were analyzed by confocal laser scanning microscopy (CLSM). Elastic modulus, hydroxyproline release and X-ray photoelectron spectroscopy (XPS) characterization were tested to evaluate the irrigants' collagen-stabilizing effect. The cytotoxicity was tested by CCK-8 assay. Quercetin increased the proportion of dead bacteria volumes within E. faecalis and improved the flexural strength of dentin compared to control group (p < 0.05). Quercetin-treated dentin matrix had less elasticity loss and hydroxyproline release after collagenase degradation (p < 0.05). Moreover, quercetin solutions revealed an increase in the C-O peak area under both C1s and O1s narrow-scan spectra of XPS characterization, and no cytotoxicity (p > 0.05). Quercetin exhibited anti-biofilm activity, a collagen-stabilizing effect with cytocompatibility, supporting quercetin as a potential candidate for endodontic irrigant.