DPSCs regulate epithelial-T cell interactions in oral submucous fibrosis.

BACKGROUND: Oral submucous fibrosis (OSF) is a precancerous lesion characterized by fibrous tissue deposition, the incidence of which correlates positively with the frequency of betel nut chewing. Prolonged betel nut chewing can damage the integrity of the oral mucosal epithelium, leading to chronic inflammation and local immunological derangement. However, currently, the underlying cellular events driving fibrogenesis and dysfunction are incompletely understood, such that OSF has few treatment options with limited therapeutic effectiveness. Dental pulp stem cells (DPSCs) have been recognized for their anti-inflammatory and anti-fibrosis capabilities, making them promising candidates to treat a range of immune, inflammatory, and fibrotic diseases. However, the application of DPSCs in OSF is inconclusive. Therefore, this study aimed to explore the pathogenic mechanism of OSF and, based on this, to explore new treatment options. METHODS: A human cell atlas of oral mucosal tissues was compiled using single-cell RNA sequencing to delve into the underlying mechanisms. Epithelial cells were reclustered to observe the heterogeneity of OSF epithelial cells and their communication with immune cells. The results were validated in vitro, in clinicopathological sections, and in animal models. In vivo, the therapeutic effect and mechanism of DPSCs were characterized by histological staining, immunohistochemical staining, scanning electron microscopy, and atomic force microscopy. RESULTS: A unique epithelial cell population, Epi1.2, with proinflammatory and profibrotic functions, was predominantly found in OSF. Epi1.2 cells also induced the fibrotic process in fibroblasts by interacting with T cells through receptor-ligand crosstalk between macrophage migration inhibitory factor (MIF)-CD74 and C-X-C motif chemokine receptor 4 (CXCR4). Furthermore, we developed OSF animal models and simulated the clinical local injection process in the rat buccal mucosa using DPSCs to assess their therapeutic impact and mechanism. In the OSF rat model, DPSCs demonstrated superior therapeutic effects compared with the positive control (glucocorticoids), including reducing collagen deposition and promoting blood vessel regeneration. DPSCs mediated immune homeostasis primarily by regulating the numbers of KRT19 + MIF + epithelial cells and via epithelial-stromal crosstalk. CONCLUSIONS: Given the current ambiguity surrounding the cause of OSF and the limited treatment options available, our study reveals that epithelial cells and their crosstalk with T cells play an important role in the mechanism of OSF and suggests the therapeutic promise of DPSCs.

Cardiovascular Outcomes in GRADE (Glycemia Reduction Approaches in Type 2 Diabetes: A Comparative Effectiveness Study).

BACKGROUND: Cardiovascular disease is a major cause of morbidity and mortality in patients with type 2 diabetes. The effects of glucose-lowering medications on cardiovascular outcomes in individuals with type 2 diabetes and low cardiovascular risk are unclear. We investigated cardiovascular outcomes by treatment group in participants randomly assigned to insulin glargine, glimepiride, liraglutide, or sitagliptin, added to baseline metformin, in GRADE (Glycemia Reduction Approaches in Type 2 Diabetes: A Comparative Effectiveness Study). METHODS: A total of 5047 participants with a mean±SD age of 57.2±10.0 years, type 2 diabetes duration of 4.0±2.7 years, and low baseline prevalence of cardiovascular disease (myocardial infarction, 5.1%; cerebrovascular accident, 2.0%) were followed for a median of 5 years. Prespecified outcomes included between-group time-to-first event analyses of MACE-3 (composite of major adverse cardiovascular events: cardiovascular death, myocardial infarction, and stroke), MACE-4 (MACE-3+unstable angina requiring hospitalization or revascularization), MACE-5 (MACE-4+coronary revascularization), MACE-6 (MACE-5+hospitalization for heart failure), and the individual components. MACE outcomes and hospitalization for heart failure in the liraglutide-treated group were compared with the other groups combined using Cox proportional hazards models. MACE-6 was also analyzed as recurrent events using a proportional rate model to compare all treatment groups. RESULTS: We observed no statistically significant differences in the cumulative incidence of first MACE-3, MACE-4, MACE-5, or MACE-6, or their individual components, by randomized treatment group. However, when compared with the other treatment groups combined, the liraglutide-treated group had a significantly lower risk of MACE-5 (adjusted hazard ratio, 0.70 [95% CI, 0.54-0.91]; P=0.021), MACE-6 (adjusted hazard ratio, 0.70 [95% CI, 0.55-0.90]; P=0.021), and hospitalization for heart failure (adjusted hazard ratio, 0.49 [95% CI, 0.28-0.86]; P=0.022). Compared with the liraglutide group, significantly higher rates of recurrent MACE-6 events occurred in the groups treated with glimepiride (rate ratio, 1.61 [95% CI, 1.13-2.29]) or sitagliptin (rate ratio 1.75; [95% CI, 1.24-2.48]). CONCLUSIONS: This comparative effectiveness study of a contemporary cohort of adults with type 2 diabetes, largely without established cardiovascular disease, suggests that liraglutide treatment may reduce the risk of cardiovascular events in patients at relatively low risk compared with other commonly used glucose-lowering medications. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01794143.

IL-36 Regulates Neutrophil Chemotaxis and Bone Loss at the Oral Barrier.

Tissue-specific mechanisms regulate neutrophil immunity at the oral barrier, which plays a key role in periodontitis. Although it has been proposed that fibroblasts emit a powerful neutrophil chemotactic signal, how this chemotactic signal is driven has not been clear. The objective of this study was to investigate the site-specific regulatory mechanisms by which fibroblasts drive powerful neutrophil chemotactic signals within the oral barrier, with particular emphasis on the role of the IL-36 family. The present study found that IL-36γ, agonist of IL-36R, could promote neutrophil chemotaxis via fibroblast. Single-cell RNA sequencing data disclosed that IL36G is primarily expressed in human and mouse gingival epithelial cells and mouse neutrophils. Notably, there was a substantial increase in IL-36γ levels during periodontitis. In vitro experiments demonstrated that IL-36γ specifically activates gingival fibroblasts, leading to chemotaxis of neutrophils. In vivo experiments revealed that IL-36Ra inhibited the infiltration of neutrophils and bone resorption, while IL-36γ promoted their progression in the ligature-induced periodontitis mouse model. In summary, these data elucidate the function of the site-enriched IL-36γ in regulating neutrophil immunity and bone resorption at the oral barrier. These findings provide new insights into the tissue-specific pathophysiology of periodontitis and offer a promising avenue for prevention and treatment through targeted intervention of the IL-36 family.

[Clinical evaluation methods for craniovertebral junction abnormalities].

Craniovertebral junction malformation is a congenital malformation located in the foramen magnum and upper cervical spine, including bone and nerve malformation, resulting in motor and sensory disorders, cerebellar and lower cranial nerves, etc. The evaluation methods of clinical symptoms and efficacy of craniovertebral junction malformation are important for the surgical indications and effects, mainly including the evaluation of clinical symptoms and the quality of life. At present, the commonly used methods in clinical work and literature are the Japanese orthopaedic association scores, visual analogue scales, 36-item short-form health survey, etc. Most of these clinical evaluations are not aimed at craniovertebral junction diseases but focus on the description of a certain type of clinical symptoms. Chicago Chiari outcome scale and syringomyelia outcome scale of Xuanwu hospital are dedicated to Craniovertebral junction malformation, but more clinical studies are needed to prove their effectiveness. Based on the literature reports, this article reviewed the previous clinical evaluation methods of craniovertebral junction malformation and discusses their applications and limitations.

[Interpretation of the European Federation of Periodontology S3 level clinical practice guideline for prevention and treatment of peri-implant diseases].

The S3 level clinical practice guideline for the prevention and treatment of peri-implant diseases, developed by the European Federation of Periodontology, was published in June, 2023 (DOI: 10.1111/jcpe.13823), which culminated in the recommendations for implementation of various different interventions before, during and after implant placement/loading. Aim of the present article is to summarize and interpret the key points of this guideline and help clinicians understand this guideline better, in order to standardize the prevention and treatment of peri-implant diseases.

[Research advances of stem cell-based tissue engineering repair materials in promoting the healing of chronic refractory wounds on the body surface].

Repairing chronic refractory wounds on the body surface is a complex medical problem involving all stages of wound healing. In recent years, stem cells (SCs) and tissue engineering (TE) have brought hope for repairing chronic refractory wounds. SCs have excellent regenerative and paracrine effects; various TE strategies have the potential to repair chronic refractory wounds on the body surface and also improve the delivery efficiency of SCs. This article reviews the pathological characteristics of chronic refractory wounds, SCs used to repair chronic refractory wounds, and SC-based TE wound repair strategies.

[Diagnosis and antidiastole of leukemia-associated gingival lesions].

Leukemia is a heterogeneous group of hematological disorders that arises from a hematopoietic stem cell characterized by a disordered differentiation and proliferation of neoplastic cells. The prevalence of leukemia is high in juveniles and adults under 35 years. Gingival manifestations of leukemia include gingiva bleeding, enlargement, pallor, petechial, ulceration, which may be the first clinical signs of leukemia. In the dental clinic, identification of leukemia-associated gingival lesions, referring patients to hematologists without delay will improve the prognosis of leukemia. Diagnosis and antidiastole of leukemia-associated gingival lesions have been discussed with reference to the related cases.

Unilateral biportal endoscopic spine surgery for lumbar spinal stenosis: a systematic review and meta-analysis.

OBJECTIVE: Lumbar spinal stenosis is the most common spinal degenerative disease in patients over 60 years, and the unilateral biportal endoscopic (UBE) spine surgery treatment of lumbar spinal stenosis (LSS) has achieved preliminary clinical results. This systematic review and meta-analysis aimed to reveal the clinical efficacy of UBE for LSS and provide evidence for clinical practice. MATERIALS AND METHODS: PubMed, Embase, Web of Science, and Cochrane databases were searched for literature. The papers selected were those published from inception till October 2021. The selected pieces of literature were graded for evidence using the Oxford Centre for Evidence-Based Medicine: Levels of Evidence (March 2009). Outcomes measures were operation time, blood loss, complication rate, admission period, Visual Analogue Scale (VAS)-back, VAS-leg, and Oswestry Disability Index (ODI) score, and radiological outcomes. The mean comparisons were based on VAS and ODI scores. RESULTS: A total of 823 patients with a single LSS segment were included from the selected nine studies. There were nine studies comparing UBE clinical outcomes and micro-endoscopic unilateral laminotomy for bilateral decompression (M-ULBD). The meta-analysis revealed that the UBE group had better VAS-leg and -back scores in the first week postoperatively [total: mean difference (MD) = -0.96, 95% confidence interval (CI): -1.19, -0.74, p < 0.00001; total: MD = -1.69, 95% CI: -1.93, -1.45, p < 0.00001], 1st month postoperatively (total: MD = -0.35, 95% CI: -0.61, -0.08, p = 0.01; total: MD = -0.40, 95% CI: -0.68, -0.12, p = 0.005), 6th month postoperatively (total: MD = -0.22, 95% CI: -0.35, -0.08, p = 0.002; total: MD = -0.24, 95% CI: -0.40, -0.07, p = 0.005), and UBE group also performed better in ODI score at 1st month postoperatively (total: MD = -3.36, 95% CI: -4.26, -2.46, p < 0.00001). There was no significant difference in VAS-leg and -back scores between both groups at the 3rd and 12th month postoperatively, and ODI scores did not significantly differ between both groups at 3, 6, and 12 months postoperatively (all p > 0.05). CONCLUSIONS: UBE has achieved good preliminary clinical results and may be a minimally invasive alternative surgery for patients with single segmental LSS.

Comparative Effects of Glucose-Lowering Medications on Kidney Outcomes in Type 2 Diabetes: The GRADE Randomized Clinical Trial.

Importance: Type 2 diabetes (T2D) is the leading cause of kidney disease in the US. It is not known whether glucose-lowering medications differentially affect kidney function. Objective: To evaluate kidney outcomes in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness (GRADE) trial comparing 4 classes of glucose-lowering medications added to metformin for glycemic management in individuals with T2D. Design, Setting, and Participants: A randomized clinical trial was conducted at 36 sites across the US. Participants included adults with T2D for less than 10 years, a hemoglobin A1c level between 6.8% and 8.5%, and estimated glomerular filtration rate (eGFR) greater than or equal to 60 mL/min/1.73 m2 who were receiving metformin treatment. A total of 5047 participants were enrolled between July 8, 2013, and August 11, 2017, and followed up for a mean of 5.0 years (range, 0-7.6 years). Data were analyzed from February 21, 2022, to March 27, 2023. Interventions: Addition of insulin glargine, glimepiride, liraglutide, or sitagliptin to metformin, with the medication combination continued until the HbA1c was greater than 7.5%; thereafter, insulin was added to maintain glycemic control. Main Outcomes and Measures: Chronic eGFR slope (change in eGFR between year 1 and trial end) and a composite kidney disease progression outcome (albuminuria, dialysis, transplant, or death due to kidney disease). Secondary outcomes included incident eGFR less than 60 mL/min/1.73 m2, 40% decrease in eGFR to less than 60 mL/min/1.73 m2, doubling of urine albumin-to-creatinine ratio (UACR) to 30 mg/g or greater, and progression of Kidney Disease Improving Global Outcomes stage. Analyses were intention-to-treat. Results: Of the 5047 participants, 3210 (63.6%) were men. Baseline characteristics were mean (SD) age 57.2 (10.0) years; HbA1c 7.5% (0.5%); diabetes duration, 4.2 (2.7) years; body mass index, 34.3 (6.8); blood pressure 128.3/77.3 (14.7/9.9) mm Hg; eGFR 94.9 (16.8) mL/min/1.73 m2; and median UACR, 6.4 (IQR 3.1-16.9) mg/g; 2933 (58.1%) were treated with renin-angiotensin-aldosterone inhibitors. Mean chronic eGFR slope was -2.03 (95% CI, -2.20 to -1.86) mL/min/1.73 m2 per year for patients receiving sitagliptin; glimepiride, -1.92 (95% CI, -2.08 to -1.75) mL/min/1.73 m2 per year; liraglutide, -2.08 (95% CI, -2.26 to -1.90) mL/min/1.73 m2 per year; and insulin glargine, -2.02 (95% CI, -2.19 to -1.84) mL/min/1.73 m2 per year (P = .61). Mean composite kidney disease progression occurred in 135 (10.6%) patients receiving sitagliptin; glimepiride, 155 (12.4%); liraglutide, 152 (12.0%); and insulin glargine, 150 (11.9%) (P = .56). Most of the composite outcome was attributable to albuminuria progression (98.4%). There were no significant differences by treatment assignment in secondary outcomes. There were no adverse kidney events attributable to medication assignment. Conclusions and Relevance: In this randomized clinical trial, among people with T2D and predominantly free of kidney disease at baseline, no significant differences in kidney outcomes were observed during 5 years of follow-up when a dipeptidyl peptidase 4 inhibitor, sulfonylurea, glucagonlike peptide 1 receptor agonist, or basal insulin was added to metformin for glycemic control. Trial Registration: ClinicalTrials.gov Identifier: NCT01794143.

[Exploration and practice of Peking University Model to improve the clinical teaching effect of clinical postgraduates majoring in periodontology].

The number of patients with periodontal disease in China is large, and the ratio of doctors to patients is seriously imbalanced, especially in the insufficient number of periodontal specialists and periodontal teachers. Strengthening the cultivation of professional postgraduates in periodontology can effectively solve this problem. This paper summarizes the experiences of Peking University School and Hospital of Stomatology in the teaching of periodontal postgraduate students for more than 30 years, in cluding teaching objectives formulation, teaching resources allocation and enhancement of the quality control system of clinical teaching, for ensuring that the periodontal professional postgraduates could reach the expected level after training. This formed the current "Peking University Model". There are both opportunities and challenges in clinical teaching of periodontal postgraduates in domestic stomatology community. The authors hope that the continuous exploration and improvement of this teaching system will promote the vigorous development of clinical teaching for the postgraduates majoring in periodontology in China.

Efficiency evaluation of common forensic genetic markers for parentage identification involving close relatives.

To explore the efficacy of commonly used forensic identification panels in complex paternity testing of trios that involved close relatives, we wrote a code by R to generate 10,000 pedigrees at 20 CODIS STR, 21 non-CODIS STR and 30 InDel loci in Chinese five ethnic groups based on their allele frequencies. Parentage identification index--cumulative paternity index (CPI) value was set as output and was further analyzed to evaluate the performance of the aforementioned panels in complex paternity testing when the alleged parent is a random individual, biological parent, grandparent, sibling of biological parent, half-sibling of biological parent, etc. The results showed that the false inclusion of parent sibling posed as parent demonstrated no statistically significant difference from that of grandparent posed as parent. The scenarios where both biological parent and alleged parent were consanguineous to the other parent were also simulated. The results revealed that the complexity of paternity testing would raise when biological parents were consanguineous and the alleged parent was a close relative of theirs. Despite the values of non-conformity number could vary in different genetic relationships, populations and panels, 20 CODIS STRs and 21 non-CODIS STRs performed satisfactorily in most simulated scenarios. However, the joint use of 20 CODIS STRs and 21 non-CODIS STRs is more recommendable when resolving the paternity testing of the incest mating case. Overall, the current study could be regarded as a worthwhile reference in complex paternity testing of trios that involved close relatives.

[Silenced ANP32A inhibits the growth, invasion and migration of colorectal cancer in vitro via the inactivation of AKT pathway].

OBJECTIVE: To investigate the effect of ANP32A silencing on invasion and migration of colon cancer cells and the influence of the activity of AKT signaling pathway on this effect. METHODS: Colorectal cancer HCT116 and SW480 were transfected with a small interfering RNA targeting ANP32A via a lentiviral vector. At 24, 48 and 72 h after the transfection, the changes in cell proliferation and AKT activity in the cells were detected using MTT assay and Western blotting, respectively. HCT116 and SW480 cells were treated with the AKT agonist SC79 or its inhibitor MK2206 for 24, 48, 72 and 96 h, and the changes in cell migration and invasion ability were analyzed using Transwell chamber assay and cell proliferation was assessed using MTT assay. The effects of SC79 and MK2206 on migration and invasion abilities of HCT116 and SW480 cells with or without ANP32A silencing were examined using wound healing and Transwell chamber assays, and the changes in the expression of metadherin (MTDH), a factor associated with cells invasion and migration, was detected with Western blotting. RESULTS: Lentivirus-mediated ANP32A silencing significantly down-regulated the activity of AKT and inhibited the proliferation of both HCT116 and SW480 cells (P < 0.01). The application of AKT inhibitor MK2206 obviously inhibited the proliferation, invasion and migration of the colorectal cancer cells (P < 0.05), while the AKT agonist SC79 significantly promoted the invasion and migration of the cells (P < 0.01). In HCT116 and SW480 cells with ANP32A silencing, treatment with MK2206 strongly enhanced the inhibitory effects of ANP32A silencing on cell invasion and migration (P < 0.05) and the expression of MTDH, while SC79 partially reversed these inhibitory effects (P < 0.01). CONCLUSION: ANP32A silencing inhibits invasion and migration of colorectal cancer cells possibly by inhibiting the activation of the AKT signaling pathway.

[Establishment and preliminary application of organoids in ovarian cancer].

Objective: To explore the establishment and application of ovarian cancer organoids. Methods: Fresh ovarian tumor tissues, obtaining from patients underwent surgery in the First Affiliated Hospital of Nanjing Medical University between October 2021 and March 2022, were collected, enzymatic degraded, digested, and embedded into matrigel to establish organoids. A total of 32 ovarian cancer samples were collected. Hematoxylin eosin (HE) staining and immunofluorescence (IF) procedure were used to verify the morphological structure of organoids and their expression of molecular markers. 3D cyto-live or dead assay was used to detecte the live or dead cells in organoids. Carboplatin with a concentration ranging from 5 to 80 µmol/L (5, 10, 20, 40, 80 µmol/L) was added to organoids to calculate the 50% inhibitory concentration (IC50) in different organoids. Results: (1) Organoids from a total of 32 patients were established, of which 18 cases could be passaged stably in the long term in vitro, while 14 could be passaged in the short time. The average amplification time of long-term passage in vitro was over 3 months, and the longest reached 9 months. (2) In HE staining, significant nuclei atypia and local micropapillary structures were observed in organoids. IF staining revealed that ovarian cancer organoids expressed molecular markers similar to primary tumor tissues, such as Pan cytokeratin (Pan-CK), p53, paired box gene 8 (PAX8), and Wilms tumor gene 1 (WT1). (3) In 3D cyto-live or dead assay, a large number of apoptotic cells were observed inside and around the organoids after added carboplatin. The sensitivity to carboplatin varied in 18 organoids could amplify in the long term, with an average IC50 of (29.5±15.8) µmol/L. Moreover, IC50 values of 4 organoids derived from patients received neoadjuvant chemotherapy were much higher than the 14 organoids which did not received neoadjuvant chemotherapy [(48.7±11.3) µmol/L vs (24.0±12.1) µmol/L; t=3.429, P=0.022]. Conclusions: Organoids recapitulate ovarian cancers in vitro and could be stably passaged. Organoids derived from patients received neoadjuvant chemotherapy have higher resistance to carboplatin.

Evaluation of polygenic risk scores to differentiate between type 1 and type 2 diabetes.

Polygenic risk scores (PRS) quantify the genetic liability to disease and are calculated using an individual's genotype profile and disease-specific genome-wide association study (GWAS) summary statistics. Type 1 (T1D) and type 2 (T2D) diabetes both are determined in part by genetic loci. Correctly differentiating between types of diabetes is crucial for accurate diagnosis and treatment. PRS have the potential to address possible misclassification of T1D and T2D. Here we evaluated PRS models for T1D and T2D in European genetic ancestry participants from the UK Biobank (UKB) and then in the Michigan Genomics Initiative (MGI). Specifically, we investigated the utility of T1D and T2D PRS to discriminate between T1D, T2D, and controls in unrelated UKB individuals of European ancestry. We derived PRS models using external non-UKB GWAS. The T1D PRS model with the best discrimination between T1D cases and controls (area under the receiver operator curve [AUC] = 0.805) also yielded the best discrimination of T1D from T2D cases in the UKB (AUC = 0.792) and separation in MGI (AUC = 0.686). In contrast, the best T2D model did not discriminate between T1D and T2D cases (AUC = 0.527). Our analysis suggests that a T1D PRS model based on independent single nucleotide polymorphisms may help differentiate between T1D, T2D, and controls in individuals of European genetic ancestry.

YAP activation inhibits inflammatory signalling and cartilage breakdown associated with reduced primary cilia expression.

OBJECTIVE: To clarify the role of YAP in modulating cartilage inflammation and degradation and the involvement of primary cilia and associated intraflagellar transport (IFT). METHODS: Isolated primary chondrocytes were cultured on substrates of different stiffness (6-1000 kPa) or treated with YAP agonist lysophosphatidic acid (LPA) or YAP antagonist verteporfin (VP), or genetically modified by YAP siRNA, all ± IL1ß. Nitric oxide (NO) and prostaglandin E2 (PGE2) release were measured to monitor IL1ß response. YAP activity was quantified by YAP nuclear/cytoplasmic ratio and percentage of YAP-positive cells. Mechanical properties of cartilage explants were tested to confirm cartilage degradation. The involvement of primary cilia and IFT was analysed using IFT88 siRNA and ORPK cells with hypomorphic mutation of IFT88. RESULTS: Treatment with LPA, or increasing polydimethylsiloxane (PDMS) substrate stiffness, activated YAP nuclear expression and inhibited IL1ß-induced release of NO and PGE2, in isolated chondrocytes. Treatment with LPA also inhibited IL1ß-mediated inflammatory signalling in cartilage explants and prevented matrix degradation and the loss of cartilage biomechanics. YAP activation reduced expression of primary cilia, knockdown of YAP in the absence of functional cilia/IFT failed to induce an inflammatory response. CONCLUSIONS: We demonstrate that both pharmaceutical and mechanical activation of YAP blocks pro-inflammatory signalling induced by IL1ß and prevents cartilage breakdown and the loss of biomechanical functionality. This is associated with reduced expression of primary cilia revealing a potential anti-inflammatory mechanism with novel therapeutic targets for treatment of osteoarthritis (OA).

Complete abrogation of key osteoclast markers with a membrane-anchored tissue inhibitor of metalloproteinase : a novel approach in the prevention of osteoclastogenesis.

AIMS: Tissue inhibitors of metalloproteinases (TIMPs) are the endogenous inhibitors of the zinc-dependent matrix metalloproteinases (MMP) and A disintegrin and metalloproteinases (ADAM) involved in extracellular matrix modulation. The present study aims to develop the TIMPs as biologics for osteoclast-related disorders. METHODS: We examine the inhibitory effect of a high affinity, glycosyl-phosphatidylinositol-anchored TIMP variant named 'T1PrαTACE' on receptor activator of nuclear factor kappa-Β ligand (RANKL)-induced osteoclast differentiation. RESULTS: Osteoclast progenitor cells transduced with T1PrαTACE failed to form tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts or exhibit bone-resorbing activity following treatment with RANKL. At the messenger RNA level, T1PrαTACE strongly attenuated expression of key osteoclast marker genes that included TRAP, cathepsin K, osteoclast stimulatory transmembrane protein (OC-STAMP), dendritic cell-specific transmembrane protein (DC-STAMP), osteoclast-associated receptor (OSCAR), and ATPase H+-transporting V0 subunit d2 (ATP6V0D2) by blocking autoamplification of nuclear factor of activated T cells 1 (NFATc1), the osteoclastogenic transcription factor. T1PrαTACE selectively extended p44/42 mitogen-activated protein kinase activation, an action that may have interrupted terminal differentiation of osteoclasts. Inhibition studies with broad-spectrum hydroxamate inhibitors confirmed that the anti-resorptive activity of T1PrαTACE was not reliant on its metalloproteinase-inhibitory activity. CONCLUSION: T1PrαTACE disrupts the RANKL-NFATc1 signalling pathway, which leads to osteoclast dysfunction. As a novel candidate in the prevention of osteoclastogenesis, the TIMP could potentially be developed for the treatment of osteoclast-related disorders such as osteoporosis.Cite this article: Bone Joint Res 2022;11(11):763-776.

[Healing of the dento-gingival junction following modified crown lengthening procedure in beagle dogs].

OBJECTIVE: To evaluate the type of wound healing following modified crown lengthening surgery in dog model to provide a biological basis for its clinical application. METHODS: Flap surgery, traditional crown lengthening procedure and modified crown lengthening procedure were performed on the right maxillary central incisor, the left maxillary central incisor and the left maxillary first lateral incisor respectively of five male beagle dogs. The right maxillary first lateral incisors with no surgical intervention were used as controls. Thirty-six weeks after the experimental procedure, tissue blocks were harvested and prepared for histological examination and analysis. RESULTS: Histometric examination of buccolingual sections stained with hematoxylin-eosin demonstrated that the type of wound healing in the flap surgery group was re-attachment, similar to the control group. For the traditional crown lengthening surgery group, all of the five beagle dogs had lamellar cementum defects on root surface, the wound healing of four beagle dogs was new attachment accompanied by new cementum formation at cementum defect areas and the suprac-restal connective tissue was functionally oriented perpendicular to the new cementum. The wound healing of the other beagle dog was long junctional epithelial attachment, in which the junctional epithelium extended to the apical terminus of the cementum defect. In the modified crown lengthening surgery group, four beagle dogs had cementum defects on root surface (two lamellar cementum defects and two shallow platform-like cementum defects), the wound healing of three beagle dogs was new attachment, however, the supracrestal connective tissue was parallel to the root surface. The type of wound healing of another one beagle dog was long junctional epithelial attachment. Wound healing of one beagle dog in this group could not be characterized due to incomplete dissection. CONCLUSION: Wound healing in the modified crown lengthening surgery group was similar to the traditional crown lengthening surgery group, and two types of wound healing were observed: new attachment and long junctional epithelium attachment. Neither type of root treatment procedure (root planing or root reshaping) nor root surface defect pattern (the lamellar cementum defect or shallow platform-like cementum defect) influenced the observed type of wound healing.