间充质干细胞命运的调控机制

Mesenchymal intricate stem cells(MSCs)represent a versatile population of multipotent progenitor cells with remarkable capacity for selfrenewal and differentiation[1].The fate commitment of MSCs is orchestrated by a complex interplay of intrinsic and extrinsic factors,encompassing signaling pathways,transcriptional regulators,epigenetic modifiers,and microenvironmental cues[2-5].

METTL7A-mediated m6A modification of corin reverses bisphosphonates-impaired osteogenic differentiation of orofacial BMSCs

Bisphosphonate-related osteonecrosis of jaw(BRONJ)is characterized by impaired osteogenic differentiation of orofacial bone marrow stromal cells(BMSCs).Corin has recently been demonstrated to act as a key regulator in bone development and orthopedic disorders.However,the role of corin in BRONJ-related BMSCs dysfunction remains unclarified.A m6A epitranscriptomic microarray study from our group shows that the CORIN gene is significantly upregulated and m6A hypermethylated during orofacial BMSCs osteogenic differentiation.Corin knockdown inhibits BMSCs osteogenic differentiation,whereas corin overexpression or soluble corin(sCorin)exerts a promotion effect.Furthermore,corin expression is negatively regulated by bisphosphonates(BPs).Corin overexpression or sCorin reverses BPs-impaired BMSCs differentiation ability.Mechanistically,we find altered expression of phos-ERK in corin knockdown/overexpression BMSCs and BMSCs under sCorin stimulation.PD98059(a selective ERK inhibitor)blocks the corin-mediated promotion effect.With regard to the high methylation level of corin during osteogenic differentiation,we apply a non-selective m6A methylase inhibitor,Cycloleucine,which also blocks the corin-mediated promotion effect.Furthermore,we demonstrate that METTL7A modulates corin m6A modification and reverses BPs-impaired BMSCs function,indicating that METTL7A regulates corin expression and thus contributes to orofacial BMSCs differentiation ability.To conclude,our study reveals that corin reverses BPs-induced BMSCs dysfunction,and METTL7A-mediated corin m6A modification underlies corin promotion of osteogenic differentiation via the ERK pathway.We hope this brings new insights into future clinical treatments for BRONJ.

Expert consensus on endodontic therapy for patients withsystemic conditions

The overall health condition of patients significantly affects the diagnosis, treatment, and prognosis of endodontic diseases. Asystemic consideration of the patient’s overall health along with oral conditions holds the utmost importance in determining thenecessity and feasibility of endodontic therapy, as well as selecting appropriate therapeutic approaches. This expert consensus is acollaborative effort by specialists from endodontics and clinical physicians across the nation based on the current clinical evidence,aiming to provide general guidance on clinical procedures, improve patient safety and enhance clinical outcomes of endodontictherapy in patients with compromised overall health.

Expert consensus on difficulty assessment of endodontic therapy

Endodontic diseases are a kind of chronic infectious oral disease. Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha. However, it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy(RCT). Recent research, encompassing bacterial etiology and advanced imaging techniques, contributes to our understanding of the root canal system’s anatomy intricacies and the technique sensitivity of RCT. Success in RCT hinges on factors like patients, infection severity, root canal anatomy, and treatment techniques. Therefore, improving disease management is a key issue to combat endodontic diseases and cure periapical lesions. The clinical difficulty assessment system of RCT is established based on patient conditions, tooth conditions, root canal configuration, and root canal needing retreatment, and emphasizes pre-treatment risk assessment for optimal outcomes. The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT. These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.

Expert consensus on irrigation and intracanal medication in root canal therapy

Chemical cleaning and disinfection are crucial steps for eliminating infection in root canal treatment. However, irrigant selection or irrigation procedures are far from clear. The vapor lock effect in the apical region has yet to be solved, impeding irrigation efficacy and resulting in residual infections and compromised treatment outcomes.

BHMT Gene Polymorphisms as Risk Factors for Cleft Lip and Cleft Palate in a Chinese Population

Objective Convincing evidence suggests a link between increased risk of nonsyndromic cleft lip with or without cleft palate （NSCL/P） and low intake of folic acid by the mother during pregnancy. The present study was designed to explore if genetic variation in the betaine‐homocysteine methyltransferase （BHMT） gene contributes to NSCL/P. Methods DNA was obtained from 166 individuals with NSCL/P and 285 healthy subjects. Three known single nucleotide polymorphisms （SNPs） present in the BHMT gene （rs651852, rs3797546, and rs3733890） were investigated by real‐time PCR‐based TaqMan genotyping. Results Neither allelic nor genotypic association was found between NSCL/P and SNPs rs651852 and rs3733890. SNP rs3797546 did not show allelic association with NSCL/P; however, a higher proportion of NSCL/P patients carry the CC genotype compared with the TT＋CT genotype （P=0.020, OR=2.10, 95% CI=1.11‐3.95）. Conclusion Our study suggests that polymorphism rs3797546 in the BHMT gene may confer genetic risk of NSCL/P in a recessive manner.

miR-4651 inhibits cell proliferation of gingival mesenchymal stem cells by inhibiting HMGA2 under nifedipine treatment

Drug-induced gingival overgrowth(DIGO) is recognized as a side effect of nifedipine(NIF);however, the underlying molecular mechanisms remain unknown. In this study, we found that overexpressed mi R-4651 inhibits cell proliferation and induces G0/G1-phase arrest in gingival mesenchymal stem cells(GMSCs) with or without NIF treatment. Furthermore, sequential window acquisition of all theoretical mass spectra(SWATH-MS) analysis, bioinformatics analysis, and dual-luciferase report assay results confirmed that high-mobility group AT-hook 2(HMGA2) is the downstream target gene of mi R-4651. Overexpression of HMGA2 enhanced GMSC proliferation and accelerated the cell cycle with or without NIF treatment. The present study demonstrates that mi R-4651 inhibits the proliferation of GMSCs and arrests the cell cycle at the G0/G1 phase by upregulating cyclin D and CDK2 while downregulating cyclin E through inhibition of HMGA2 under NIF stimulation. These findings reveal a novel mechanism regulating DIGO progression and suggest the potential of mi R-4651 and HMGA2 as therapeutic targets.

The lingualized occlusion of complete denture

This article reviews the literatures dealing with the lingualized occlusion of complete denture including the origin,development and research.Lingualized occlusion is a valuable concept because many advantages of anatomic and nonanatomic occlusions are retained,satisfactory occlusion is easily obtained,balanced occlusion can be accomplished.

Clinical trials using dental stem cells:2022 update

For nearly 20 years,dental stem cells(DSCs)have been successfully isolated from mature/immature teeth and surrounding tissue,including dental pulp of permanent teeth and exfoliated deciduous teeth,periodontal ligaments,dental follicles,and gingival and apical papilla.They have several properties(such as self-renewal,multidirectional differentiation,and immunomodulation)and exhibit enormous potential for clinical applications.To date,many clinical articles and clinical trials using DSCs have reported the treatment of pulpitis,periapical lesions,periodontitis,cleft lip and palate,acute ischemic stroke,and so on,and DSC-based therapies obtained satisfactory effects in most clinical trials.In these studies,no adverse events were reported,which suggested the safety of DSC-based therapy.In this review,we outline the characteristics of DSCs and summ-arize clinical trials and their safety as DSC-based therapies.Meanwhile,we also present the current limitations and perspectives of DSC-based therapy(such as harvesting DSCs from inflamed tissue,applying DSC-conditioned medi-um/DSC-derived extracellular vesicles,and expanding-free strategies)to provide a theoretical basis for their clinical applications.

Autonomic reinnervation and functional regeneration in autologous transplanted submandibular glands in patients with severe keratoconjunctivitis sicca

Autologous submandibular gland（SMG） transplantation has been proved to ameliorate the discomforts in patients with severe keratoconjunctivitis sicca. The transplanted glands underwent a hypofunctional period and then restored secretion spontaneously.This study aims to investigate whether autonomic nerves reinnervate the grafts and contribute to the functional recovery, and further determine the origin of these nerves. Parts of the transplanted SMGs were collected from the epiphora patients, and a rabbit SMG transplantation model was established to fulfill the serial observation on the transplanted glands with time. The results showed that autonomic nerves distributed in the transplanted SMGs and parasympathetic ganglionic cells were observed in the stroma of the glands. Low-dense and unevenly distributed cholinergic axons, severe acinar atrophy and fibrosis were visible in the patients＇ glands 4–6 months post-transplantation, whereas the cholinergic axon density and acinar area were increased with time. The acinar area or the secretory flow rate of the transplanted glands was statistically correlated with the cholinergic axon density in the rabbit model, respectively. Meanwhile, large cholinergic nerve trunks were found to locate in the temporal fascia lower to the gland, and sympathetic plexus concomitant with the arteries was observed both in the adjacent fascia and in the stroma of the glands. In summary, the transplanted SMGs are reinnervated by autonomic nerves and the cholinergic nerves play a role in the morphological and functional restoration of the glands. Moreover, these autonomic nerves might originate from the auriculotemporal nerve and the sympathetic plexus around the supplying arteries.

The Association between Folate Pathway Genes and Cleft Lip With or Without Cleft Palate in a Chinese Population

NSCL/P is a common congenital defect and gene-environmental factors involve in this disorder. Periconceptional intake of folate may reduce the risk of NSCL/P. The present study investigated three SNPs （rs1801198, rs955516, and rs3733890） in three folate pathway genes, including TCN2, MTR, and BHMT among 481 patients and 558 healthy subjects. Rs955516 showed allelic association with NSCL/P. More patients carry rs955516 AA and rs3733890 AA genotypes.

MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1

Mesenchymal stem cell(MSC)-based therapy has emerged as a promising treatment for spinal cord injury(SCI),but improving the neurogenic potential of MSCs remains a challenge.Mixed lineage leukemia 1(MLL1),an H3K4me3 methyltransferases,plays a critical role in regulating lineage-specific gene expression and influences neurogenesis.In this study,we investigated the role and mechanism of MLL1 in the neurogenesis of stem cells from apical papilla(SCAPs).We examined the expression of neural markers,and the nerve repair and regeneration ability of SCAPs using dynamic changes in neuron-like cells,immunofluorescence staining,and a SCI model.We employed a coimmunoprecipitation(Co-IP)assay,real-time RT-PCR,microarray analysis,and chromatin immunoprecipitation(ChIP)assay to investigate the molecular mechanism.The results showed that MLL1 knock-down increased the expression of neural markers,including neurogenic differentiation factor(NeuroD),neural cell adhesion molecule(NCAM),tyrosine hydroxylase(TH),βIII-tubulin and Nestin,and promoted neuron-like cell formation in SCAPs.In vivo,a transplantation experiment showed that depletion of MLL 1 in SCAPs can restore motor function in a rat SCI model.MLL1 can combine with WD repeat domain 5(WDR5)and WDR5 inhibit the expression of neural markers in SCAPs.MLL1 regulates Hairy and enhancer of split 1(HES1)expression by directly binds to HES1 promoters via regulating H3K4me3 methylation by interacting with WDR5.Additionally,HES1 enhances the expression of neural markers in SCAPs.Our findings demonstrate that MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1.These results provide a potential therapeutic target for promoting the recovery of motor function in SCI patients.

Specific RNA m6A modification sites in bone marrow mesenchymal stem cells from the jawbone marrow of type 2 diabetes patients with dental implant failure

The failure rate of dental implantation in patients with well-controlled type 2 diabetes mellitus(T2DM)is higher than that in nondiabetic patients.This due,in part,to the impaired function of bone marrow mesenchymal stem cells(BMSCs)from the jawbone marrow of T2DM patients(DM-BMSCs),limiting implant osseointegration.RNA N6-methyladenine(m6A)is important for BMSC function and diabetes regulation.However,it remains unclear how to best regulate m6A modifications in DM-BMSCs to enhance function.Based on the“m6A site methylation stoichiometry”of m6A single nucleotide arrays,we identified 834 differential m6Amethylated genes in DM-BMSCs compared with normal-BMSCs(N-BMSCs),including 43 and 790 m6A hypermethylated and hypomethylated genes,respectively,and 1 gene containing hyper-and hypomethylated m6A sites.Differential m6A hypermethylated sites were primarily distributed in the coding sequence,while hypomethylated sites were mainly in the 3’-untranslated region.The largest and smallest proportions of m6A-methylated genes were on chromosome 1 and 21,respectively.Maz F-PCR and real-time RTPCR results for the validation of erythrocyte membrane protein band 4.1 like 3,activity-dependent neuroprotector homeobox(ADNP),growth differentiation factor 11(GDF11),and regulator of G protein signalling 2 agree with m6A single nucleotide array results;ADNP and GDF11 m RNA expression decreased in DM-BMSCs.Furthermore,gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses suggested that most of these genes were enriched in metabolic processes.This study reveals the differential m6A sites of DM-BMSCs compared with N-BMSCs and identifies candidate target genes to enhance BMSC function and improve implantation success in T2DM patients.

Expert consensus on digital guided therapy for endodontic diseases

Digital guided therapy(DGT)has been advocated as a contemporary computer-aided technique for treating endodontic diseases in recent decades.The concept of DGT for endodontic diseases is categorized into static guided endodontics(SGE),necessitating a meticulously designed template,and dynamic guided endodontics(DGE),which utilizes an optical triangulation tracking system.Based on cone-beam computed tomography(CBCT)images superimposed with or without oral scan(OS)data,a virtual template is crafted through software and subsequently translated into a 3-dimensional(3D)printing for SGE,while the system guides the drilling path with a real-time navigation in DGE.DGT was reported to resolve a series of challenging endodontic cases,including teeth with pulp obliteration,teeth with anatomical abnormalities,teeth requiring retreatment,posterior teeth needing endodontic microsurgery,and tooth autotransplantation.Case reports and basic researches all demonstrate that DGT stand as a precise,time-saving,and minimally invasive approach in contrast to conventional freehand method.This expert consensus mainly introduces the case selection,general workflow,evaluation,and impact factor of DGT,which could provide an alternative working strategy in endodontic treatment.

Difficult and complicated oral ulceration:an expert consensus guideline for diagnosis

The complexity of oral ulcerations poses considerable diagnostic and therapeutic challenges to oral specialists.The expert consensus was conducted to summarize the diagnostic work-up for difficult and complicated oral ulcers,based on factors such as detailed clinical medical history inquiry,histopathological examination,and ulceration-related systemic diseases screening.Not only it can provide a standardized procedure of oral ulceration,but also it can improve the diagnostic efficiency,in order to avoid misdiagnosis and missed diagnosis.

Pharmacokinetics and pharmacodynamics of cisatracurium in children undergoing cleft lip or cleft palate repair surgery

OBJECTIVE The aim of the study was to characterize the pharmacokinetics(PK) and pharmacodynamics(PD) profile of cisatracurium in 0-2 years and 2-5 years old children patients with cheilopalatognathus,to find if there are some connections between the different muscle relaxation action and different PK procedure.METHODS 14 children patients were divided into two groups,≤2 years and 2-5 years group,venous samples were taken before injection of a 0.15 mg·kg-1 dose of cisatracurium and then at 2,5,10,30,60,90,and 120 min.Cisatracurium plasma concentrations were determined by ultra-performance liquid chromatography/electrospray ionization/triple quadrupole tandem mass spectrometer system(UPLC/MS/MS).The degree of neuromuscular block was measured by train of four(TOF) testing.An indirect PK-PD link model with a sigmoid E max model was established using Win Nonlin software.The model were applied to PK and PD data analysis,respectively.RESULTS The TOF monitor parameters showed that cisatracurium works very quickly,the onset time were(2.64±0.93) min and(2.59 ± 0.90) min for ≤2 years and 2-5 years group respectively.Young children ≤2 years have longer muscle blocking duration time(62.5 ± 6.01 min vs 53.86 ± 12.18 min) and slower recovery index(32.14±7.10 min and 27.43±10.63 min) than those children in group of 2-5 years.More children ≤2 years have postoperative complication than that in 2-5 children.PK parameters showed that there were no statistical differences in blood concentration and pharmacokinetic parameters.While the concentration of cisatracurium in muscle site calculated by using PK/PD model were higher and longer for ≤2 year children than that of 2-5 year children.This means that cisatracurium could stay at high concentration for a longer time in younger children' muscle tissue.CONCLUSION As a result young children tend to have postoperative complications related to slower muscle recovery action and increased concentration in skeletal muscle.So more careful observation and monitor are needed for younger children,our study could be of use in clinical practice for the administration of cisatracurium to children patients.

Experts consensus on the procedure of dental operative microscope in endodontics and operative dentistry

The dental operative microscope has been widely employed in the field of dentistry,particularly in endodontics and operative dentistry,resulting in significant advancements in the effectiveness of root canal therapy,endodontic surgery,and dental restoration.However,the improper use of this microscope continues to be common in clinical settings,primarily due to operators’insufficient understanding and proficiency in both the features and established operating procedures of this equipment.In October 2019,Professor Jingping Liang,Vice Chairman of the Society of Cariology and Endodontology,Chinese Stomatological Association,organized a consensus meeting with Chinese experts in endodontics and operative dentistry.The objective of this meeting was to establish a standard operation procedure for the dental operative microscope.Subsequently,a consensus was reached and officially issued.Over the span of about four years,the content of this consensus has been further developed and improved through practical experience.

Molecular mechanisms of cellular metabolic homeostasis in stem cells

Many tissues and organ systems have intrinsic regeneration capabilities that are largely driven and maintained by tissue-resident stem cell populations. In recent years, growing evidence has demonstrated that cellular metabolic homeostasis plays a central role in mediating stem cell fate, tissue regeneration, and homeostasis. Thus, a thorough understanding of the mechanisms that regulate metabolic homeostasis in stem cells may contribute to our knowledge on how tissue homeostasis is maintained and provide novel insights for disease management. In this review, we summarize the known relationship between the regulation of metabolic homeostasis and molecular pathways in stem cells. We also discuss potential targets of metabolic homeostasis in disease therapy and describe the current limitations and future directions in the development of these novel therapeutic targets.

A novel mutation in ROR2 led to the loss of function of ROR2 and inhibited the osteogenic differentiation capability of bone marrow mesenchymal stem cells(BMSCs)

Receptor tyrosine kinase-like orphan receptor 2(ROR2)has a vital role in osteogenesis.However,the mechanism underlying the regulation of ROR2 in osteogenic differentiation is still poorly comprehended.A previous study by our research group showed that a novel compound heterozygous ROR2 variation accounted for the autosomal recessive Robinow syndrome(ARRS).This study attempted to explore the impact of the ROR2:c.904C>T variant specifically on the osteogenic differentiation of BMSCs.Methods:Coimmunoprecipitation(CoIP)-western blotting was carried out to identify the interaction between ROR2 and Wnt5a.Double-immunofluorescence staining was used for determining the expressions and co-localization of ROR2 and Wnt5a in bone marrow mesenchymal stem cells(BMSCs).Western blot(WB)analysis and quantitative reverse transcription polymerase chain reaction(RT-qPCR)were conducted to identify the expression levels of ROR2 in the BMSCs transfected with LV-shROR2 or LV-ROR2-c.904C>T.The alkaline phosphatase(ALP)activity was detected,and Alizarin Red S staining was done for evaluating the osteogenic differentiation of BMSCs.RT-qPCR was employed to identify the expression of the sphingomyelin synthase 1(SMS1)mRNA in the BMSCs transfected with LV-shROR2 or LV-ROR2-c.904C>T and the mRNA expression levels of Runt-related transcription factor 2(RUNX2),osteocalcin(OCN),and osteopontin(OPN).WB was performed to confirm the protein expressions of extracellular regulated protein kinases1(ERK),P-ERK,Smad family member1/5/8(Smad1/5/8),P-Smad1/5/8,P-P38,P38,RUNX2,OCN,and OPN in the BMSCs transfected with LV-shROR2/LV-ROR2-c.904C>T and sphingomyelin(SM).Results:The ROR2:c.904C>T mutant altered the subcellular localization of the ROR2 protein,which caused an impaired interaction between ROR2 and Wnt5a.The depletion of ROR2 restricted the osteogenic differentiation capability of BMSCs and downregulated the expression of SMS1.SM treatment could reverse the inhibition of osteoblastic differentiation in ROR2-depleted BMSCs.Conclusion:The findings of this work revealed that the ROR2:c.904C>T variant led to the loss of function of ROR2,which impaired the interaction between ROR2 and Wnt5a and also controlled the osteogenic differentiation capability of BMSCs.Furthermore,SM was revealed to be engaged in the osteoblastic differentiation of BMSCs regulated by ROR2,which renders SM a potential target in the therapy for ARRS.