Engineered extracellular vesicles for delivering functional Cas9/gRNA to eliminate hepatitis B virus cccDNA and integration

The persistence of HBV covalently closed circular DNA (cccDNA) and HBV integration into the host genome in infected hepatocytes pose significant challenges to the cure of chronic HBV infection. Although CRISPR/Cas9-mediated genome editing shows promise for targeted clearance of viral genomes, a safe and efficient delivery method is currently lacking. Here, we developed a novel approach by combining light-induced heterodimerization and protein acylation to enhance the loading efficiency of Cas9 protein into extracellular vesicles (EVs). Moreover, vesicular stomatitis virus-glycoprotein (VSV-G) was incorporated onto the EVs membrane, significantly facilitating the endosomal escape of Cas9 protein and increasing its gene editing activity in recipient cells. Our results demonstrated that engineered EVs containing Cas9/gRNA and VSV-G can effectively reduce viral antigens and cccDNA levels in the HBV-replicating and infected cell models. Notably, we also confirmed the antiviral activity and high safety of the engineered EVs in the HBV-replicating mouse model generated by hydrodynamic injection and the HBV transgenic mouse model. In conclusion, engineered EVs could successfully mediate functional CRISPR/Cas9 delivery both in vitro and in vivo, leading to the clearance of episomal cccDNA and integrated viral DNA fragments, and providing a novel therapeutic approach for curing chronic HBV infection.

An Immunocompetent Mongolian Gerbil Model for Hepatitis E Virus Genotype 1 Infection

BACKGROUND AND AIMS

Hepatitis E virus (HEV), primarily genotype 1 (HEV-1), causes approximately 20.1 million infections, 44,000 deaths, and 3000 stillbirths annually. Current evidence indicates that HEV-1 is only transmitted in humans. Here, we evaluated whether Mongolian gerbils can serve as animal models for HEV-1 infection.

METHODS

Mongolian gerbils were used for HEV-1 and hepatitis E virus genotype 3 infection experiments. HEV infection parameters, including detection of HEV RNA and HEV antigen, liver function assessment, and histopathology, were evaluated.

RESULTS

We adapted a clinical isolate of HEV-1 for Mongolian gerbils by serial passaging in feces of aged male gerbils. The gerbil-adapted strain obtained at passage 3 induced a robust, acute HEV infection, characterized by stable fecal virus shedding, elevated liver enzymes, histopathologic changes in the liver, and seroconversion to anti-HEV. An infectious complementary DNA clone of the adapted virus was generated. HEV-1-infected pregnant gerbils showed a high rate of maternal mortality and vertical transmission. HEV RNA or antigens were detected in the liver, kidney, intestine, placenta, testis, and fetus liver. Liver and placental transcriptomic analyses indicated activation of host immunity. Tacrolimus prolonged HEV-1 infection, whereas ribavirin cleared infection. The protective efficacy of a licensed HEV vaccine was validated using this model.

CONCLUSIONS

HEV-1 efficiently infected Mongolian gerbils. This HEV-1 infection model will be valuable for investigating hepatitis E immunopathogenesis and evaluating vaccines and antivirals against HEV.

Salicin alleviates periodontitis via Tas2r143/gustducin signaling in fibroblasts

Introduction

Cells expressing taste signaling elements in non-gustatory tissues have been described as solitary chemosensory cells (SCCs) or tuft cells. These "taste-like" cells play a critical role in the maintenance of tissue homeostasis. Although the expression of SCC markers and taste signaling constituents has been identified in mouse gingivae, their role in periodontal homeostasis is still unclear.

Methods

Public RNA sequencing datasets were re-analyzed and further validated with RT-PCR/qRT-PCR and immunofluorescent staining to explore the expression of TAS2Rs and downstream signaling constituents in mouse gingival fibroblasts (MGFs). The specific action of salicin on MGFs via Tas2r143 was validated with RNA silence, heterologous expression of taste receptor/Gα-gustducin and calcium imaging. The anti-inflammatory effects of salicin against LPS-induced MGFs were investigated in cell cultures, and were further validated with a ligature-induced periodontitis mouse model using Ga-gustducin-null (Gnat3-/-) mice.

Results

The expression of Tas2r143, Gnat3, Plcb2, and TrpM5 was detected in MGFs. Moreover, salicin could activate Tas2r143, elicited taste signaling and thus inhibited LPS-induced chemokines expression (CXCL1, CXCL2, and CXCL5) in MGFs. Consistently, salicin-treatment inhibited periodontal bone loss, inflammatory/chemotactic factors expression, and neutrophil infiltration in periodontitis mice, while these effects were abolished in Gnat3-/- mice.

Discussion

Gingival fibroblasts play a critical role in the maintenance of periodontal homeostasis via "SCC-like" activity. Salicin can activate Tas2r143-mediated bitter taste signaling and thus alleviate periodontitis in mouse, indicating a promising approach to the resolution of periodontal inflammation via stimulating the "SCC-like" function of gingival fibroblasts.

Histone-modifying enzymes: Roles in odontogenesis and beyond

OBJECTIVES

Odontogenesis, an intricate process initiated by epithelium-mesenchyme interaction, is meticulously regulated by a cascade of regulatory mechanisms. Epigenetic modifications, especially histone modification, have been found to exhibit spatiotemporal specificity during tooth development. However, the expression patterns and roles of enzymes associated with histone modifications have yet to be systematically explored in odontogenesis. This review aims to summarize the histone-modifying enzymes in odontogenesis and their regulation mechanism during tooth development and provide the potential theoretical basis for the clinical management and intervention of dental developmental diseases.

SUBJECTS AND METHODS

This study conducted a systematic search across PubMed and Web of Science databases, utilizing the keywords "odontogenesis," "histone modification," and "enzyme" for pertinent articles.

RESULTS

No doubt histone modification contributes extensively to odontogenesis regulation, and the disturbances in histone modifications can derange the odontogenesis process.

CONCLUSION

Further studies are warranted to elucidate these roles and their potential downstream effects, positioning histone modifications as a pivotal focal point for unraveling the intricacies of tooth development and regeneration.

UCHL1 is a potential molecular indicator and therapeutic target for neuroendocrine carcinomas

Neuroendocrine carcinomas, such as neuroendocrine prostate cancer and small-cell lung cancer, commonly have a poor prognosis and limited therapeutic options. We report that ubiquitin carboxy-terminal hydrolase L1 (UCHL1), a deubiquitinating enzyme, is elevated in tissues and plasma from patients with neuroendocrine carcinomas. Loss of UCHL1 decreases tumor growth and inhibits metastasis of these malignancies. UCHL1 maintains neuroendocrine differentiation and promotes cancer progression by regulating nucleoporin, POM121, and p53. UCHL1 binds, deubiquitinates, and stabilizes POM121 to regulate POM121-associated nuclear transport of E2F1 and c-MYC. Treatment with the UCHL1 inhibitor LDN-57444 slows tumor growth and metastasis across neuroendocrine carcinomas. The combination of UCHL1 inhibitors with cisplatin, the standard of care used for neuroendocrine carcinomas, significantly delays tumor growth in pre-clinical settings. Our study reveals mechanisms of UCHL1 function in regulating the progression of neuroendocrine carcinomas and identifies UCHL1 as a therapeutic target and potential molecular indicator for diagnosing and monitoring treatment responses in these malignancies.

MicroRNA-93-5p regulates odontogenic differentiation and dentin formation via KDM6B

BACKGROUND

Epigenetic factors influence the odontogenic differentiation of dental pulp stem cells and play indispensable roles during tooth development. Some microRNAs can epigenetically regulate other epigenetic factors like DNA methyltransferases and histone modification enzymes, functioning as epigenetic-microRNAs. In our previous study, microarray analysis suggested microRNA-93-5p (miR-93-5p) was differentially expressed during the bell stage in human tooth germ. Prediction tools indicated that miR-93-5p may target lysine-specific demethylase 6B (KDM6B). Therefore, we explored the role of miR-93-5p as an epi-miRNA in tooth development and further investigated the underlying mechanisms of miR-93-5p in regulating odontogenic differentiation and dentin formation.

METHODS

The expression pattern of miR-93-5p and KDM6B of dental pulp stem cells (DPSCs) was examined during tooth development and odontogenic differentiation. Dual luciferase reporter and ChIP-qPCR assay were used to validate the target and downstream regulatory genes of miR-93-5p in human DPSCs (hDPSCs). Histological analyses and qPCR assays were conducted for investigating the effects of miR-93-5p mimic and inhibitor on odontogenic differentiation of hDPSCs. A pulpotomy rat model was further established, microCT and histological analyses were performed to explore the effects of KDM6B-overexpression and miR-93-5p inhibition on the formation of tertiary dentin.

RESULTS

The expression level of miR-93-5p decreased as odontoblast differentiated, in parallel with elevated expression of histone demethylase KDM6B. In hDPSCs, miR-93-5p overexpression inhibited the odontogenic differentiation and vice versa. MiR-93-5p targeted 3' untranslated region (UTR) of KDM6B, thereby inhibiting its protein translation. Furthermore, KDM6B bound the promoter region of BMP2 to demethylate H3K27me3 marks and thus upregulated BMP2 transcription. In the rat pulpotomy model, KDM6B-overexpression or miR-93-5p inhibition suppressed H3K27me3 level in DPSCs and consequently promoted the formation of tertiary dentin.

CONCLUSIONS

MiR-93-5p targets epigenetic regulator KDM6B and regulates H3K27me3 marks on BMP2 promoters, thus modulating the odontogenic differentiation of DPSCs and dentin formation.

Corrigendum: Tooth loss, denture use, and all-cause and cause-specific mortality in older adults: a community cohort study

[This corrects the article DOI: 10.3389/fpubh.2023.1194054.].

Appropriate timing of treatment contributes to better root development of impacted anterior teeth in children

INTRODUCTION

This study investigated the effects of different timings of orthodontic treatment on the root development of impacted anterior teeth in children.

METHODS

The cone-beam computed tomography (CBCT) data of 45 children with impacted anterior teeth were divided into unformed root (UR) group or basically formed root (BFR) group to evaluate root length (RL) and root growth length (RGL) of impacted teeth and contralateral nonimpacted teeth pretreatment and posttreatment. In addition, 22 patients with impacted dilaceration were selected to assess the effects of the crown-root angle and root development stage on RL and RGL. The Student t test, Wilcoxon test, analysis of variance, and multiple linear regression analysis were used for statistical evaluations.

RESULTS

The RL of treated impacted teeth pretreatment and posttreatment was significantly shorter than contralateral nonimpacted teeth values (P <0.05). Posttreatment, the RL and RGL of impacted teeth of the UR group were significantly greater than those of the BFR group (P <0.05). The RGL of the dilacerated root in the UR group was considerably higher than in the BFR group (P <0.05). The larger crown-root angle group had a longer posttreatment RL (P <0.05). Multiple linear regression analysis revealed that the Nolla stage of impacted teeth and RL of contralateral teeth pretreatment significantly influenced the RL of impacted teeth posttreatment.

CONCLUSIONS

Prompt orthodontic treatment is necessary for children with impacted anterior teeth to release the impacted state and achieve better root development. The root length of a dilacerated tooth continued to develop under treatment, but the crown-root angle partly constrained it.

Global bibliometric mapping of dental development research for the period 2012-2021

BACKGROUND

Dental development is a complex long-term biological process, significant attention should be paid to the dental development and health of this critical time window in childhood for the oral health of the whole life cycle.

AIM

This study aimed to conduct bibliometric studies on the scientific outputs of global dental development research by the CiteSpace software.

DESIGN

The global scientific outputs about dental development between January 1, 2012, and December 31, 2021, retrieved from Web of Science Core Collection, CiteSpace, and Microsoft Excel were applied for this bibliometric study.

RESULTS

A total of 3746 reviews and articles were obtained from the Web of Science core database for exploring the basic publication characteristics, hotspots, and frontiers of this research field. The results showed that dental development is gaining more researcher's attention over time. In terms of countries, the USA and China were the major contributors to this research area. At the institutional level, Sichuan University ranked first. Meanwhile, international cooperation across regions was quite active. The Journal of Dental Research has exerted a broad and far-reaching influence on dental development research in both publications and citations. James P Simmer, Jungwook Kim, Charles E Smith, and Jan CC Hu are among the most influential scholars in this field. Finally, the future hotspots were proposed, covering three directions: dental analysis, tooth development, and post-translational phosphorylation of histones.

CONCLUSION

In the past decade, the field of dental development has developed rapidly, and the cooperation between scholars, institutions, and researchers has become increasingly close.

[Enamel developmental defects: environmental factors and clinical management]

Enamel formation is a complex physiological process that depends on the coordinated regulation of multiple mechanisms. This process is quite sensitive to various local and systemic interference factors. Therefore, during the long period from the embryonic stage to adolescence or even adulthood, various interference factors may lead to enamel developmental defects. Among them, early life is the most sensitive stage to environmental factors exposure, while it is also the critical period of enamel development of deciduous and permanent teeth. Environmental factors exposure during this period often leads to varying degrees of enamel development defects. In this review, we generalize the research progress of environmental factors affecting enamel developmental defects, summarize the potential mechanisms of environmental factors leading to enamel developmental defects, and conclude the clinical management strategies based on tertiary prevention. This work hopes to provide a theoretical basis for preventing abnormal teeth development from the critical time window of early life, propose eugenics health consultation and promote children 's oral health management.

An antibody-based molecular switch for continuous small-molecule biosensing

We present a generalizable approach for designing biosensors that can continuously detect small-molecule biomarkers in real time and without sample preparation. This is achieved by converting existing antibodies into target-responsive "antibody-switches" that enable continuous optical biosensing. To engineer these switches, antibodies are linked to a molecular competitor through a DNA scaffold, such that competitive target binding induces scaffold switching and fluorescent signaling of changing target concentrations. As a demonstration, we designed antibody-switches that achieve rapid, sample preparation-free sensing of digoxigenin and cortisol in undiluted plasma. We showed that, by substituting the molecular competitor, we can further modulate the sensitivity of our cortisol switch to achieve detection at concentrations spanning 3.3 nanomolar to 3.3 millimolar. Last, we integrated this switch with a fiber optic sensor to achieve continuous sensing of cortisol in a buffer and blood with <5-min time resolution. We believe that this modular sensor design can enable continuous biosensor development for many biomarkers.

Epigenetics in developmental defects of enamel: A scoping review

OBJECTIVES

The significant role of epigenetics has been revealed in normal enamel formation process and occurrence of developmental defects. This presented literature is aiming at summarizing the regulatory function of epigenetics in physiological amelogenesis process and reviewing the epigenetic mechanisms in occurrence of developmental defects of enamel (DDE), so as to provide biological foundation evidence to support early predication and clinical management of DDE.

METHOD

An extensive literature review was conducted using electronic databases MEDLINE (through PubMed), Web of Science and EMBASE up to November 30, 2022. Studies about epigenetic effects on enamel tissue or cells associated with amelogenesis, including in vivo studies using human or animal models, and in vitro studies, are selected.

RESULTS

A total of 22 studies were included. Epigenetic factors or effects specifically activate or silence certain genes, which may regulate related biological activities including cell proliferation, cell differentiation, enamel secretion, and mineralization during the process of amelogenesis. Once the status of epigenetic modification is altered, the quantity and quality of enamel may both be disturbed, which can finally result in DDE.

CONCLUSION

Epigenetics plays a noteworthy role of regulating the amelogenesis process and DDE potentially by altering the expression levels of genes related to enamel formation, providing a new perspective of early predication and clinical management of DDE.

[Expert consensus on the biobank development of oral genetic diseases and rare diseases and storage codes of related biological samples from craniofacial and oral region]

The biological samples of oral genetic diseases and rare diseases are extremely precious. Collecting and preserving these biological samples are helpful to elucidate the mechanisms and improve the level of diagnose and treatment of oral genetic diseases and rare diseases. The standardized construction of biobanks for oral genetic diseases and rare diseases is important for achieving these goals. At present, there is very little information on the construction of these biobanks, and the standards or suggestions for the classification and coding of biological samples from oral and maxillofacial sources, and this is not conducive to the standardization and information construction of biobanks for special oral diseases. This consensus summarizes the background, necessity, principles, and key points of constructing the biobank for oral genetic diseases and rare diseases. On the base of the group standard "Classification and Coding for Human Biomaterial" (GB/T 39768-2021) issued by the National Technical Committee for Standardization of Biological Samples, we suggest 76 new coding numbers for different of biological samples from oral and maxillofacial sources. We hope the consensus may promote the standardization, and smartization on the biobank construction as well as the overall research level of oral genetic diseases and rare diseases in China.

Tooth loss, denture use, and all-cause and cause-specific mortality in older adults: a community cohort study

Objectives

The available evidence on the connections between tooth loss, denture use, and mortality from all causes or specific causes among older adults is inconclusive. Therefore, we aimed to investigate the association between tooth loss, denture use, and all-cause and cause-specific mortality in older adults.

Methods

A cohort of 5,403 participants aged 65 and older were recruited in the 2014 Chinese Longitudinal Healthy Longevity Survey wave and followed up in the 2018 wave. Cox proportional hazard models were used to examine the association between the number of natural teeth, denture use, and all-cause and cause-specific mortality.

Results

During a mean (SD) follow-up of 3.1  years (1.3), 2,126 deaths (39.3%) occurred. Individuals with 0 and 1-9 teeth had higher mortality due to all-cause, cardiovascular disease (CVD), cancer, and other causes (all p-trend <0.05) than those with 20+ teeth. At the same time, no association was found with respiratory disease mortality. Participants who used dentures had lower mortality due to all causes [hazard ratios (HR) 0.79, 95% confidence intervals (CI) 0.71-0.88], CVD (HR 0.80, 95% CI 0.64-1.00), respiratory disease (HR 0.66, 95% CI 0.48-0.92), and other causes (HR 0.77, 95% CI 0.68-0.88) than those without dentures. Joint analysis revealed that older adults with fewer natural teeth and no dentures had higher mortality. Additionally, interaction analyses showed that the effects of the number of natural teeth on all-cause mortality were more pronounced in older adults aged <80  years (p-value for interaction = 0.03).

Conclusion

Having fewer natural teeth, particularly less than 10 teeth, is linked to an increased risk of mortality from all causes, including CVD, cancer, and other causes, but not respiratory disease. The use of dentures would mitigate the adverse impact of tooth loss on all-cause and some cause-specific mortality.

LncRNA CARMN facilitates odontogenic differentiation of dental pulp cells by impairing EZH2

OBJECTIVE

This study aimed to reveal the potential role of CARMN in odontogenic differentiation of dental pulp cells (DPCs).

METHODS

Laser capture microdissection was used to detect Carmn in DPCs and odontoblasts in P0 mice. After manipulating CARMN expression in odontogenic differentiation induced hDPCs, the state of odontogenic differentiation was evaluated by ALP staining, ARS, and related marker expression in qRT-PCR and western blotting. The subcutaneous transplantation of HA/β-TCP loaded with hDPCs was performed to verify CARMN's role in promoting odontogenic differentiation in vivo. RNAplex and RIP were employed to reveal potential mechanism of CARMN in hDPCs.

RESULTS

CARMN expressed more abundantly in odontoblasts than DPCs in P0 mice. CARMN expression boosted during in vitro odontogenic differentiation of hDPCs. CARMN overexpression enhanced odontogenic differentiation of hDPCs in vitro, while inhibition impaired the process. CARMN overexpression in HA/β-TCP composites promoted more mineralized nodule formation in vivo. CARMN knockdown led to soared EZH2, while CARMN overexpression brought about EZH2 inhibition. CARMN functioned via direct interaction with EZH2.

CONCLUSIONS

The results uncovered CARMN as a modulator during the odontogenic differentiation of DPCs. CARMN promoted odontogenic differentiation of DPCs by impairing EZH2.

A massively parallel screening platform for converting aptamers into molecular switches

Aptamer-based molecular switches that undergo a binding-induced conformational change have proven valuable for a wide range of applications, such as imaging metabolites in cells, targeted drug delivery, and real-time detection of biomolecules. Since conventional aptamer selection methods do not typically produce aptamers with inherent structure-switching functionality, the aptamers must be converted to molecular switches in a post-selection process. Efforts to engineer such aptamer switches often use rational design approaches based on in silico secondary structure predictions. Unfortunately, existing software cannot accurately model three-dimensional oligonucleotide structures or non-canonical base-pairing, limiting the ability to identify appropriate sequence elements for targeted modification. Here, we describe a massively parallel screening-based strategy that enables the conversion of virtually any aptamer into a molecular switch without requiring any prior knowledge of aptamer structure. Using this approach, we generate multiple switches from a previously published ATP aptamer as well as a newly-selected boronic acid base-modified aptamer for glucose, which respectively undergo signal-on and signal-off switching upon binding their molecular targets with second-scale kinetics. Notably, our glucose-responsive switch achieves ~30-fold greater sensitivity than a previously-reported natural DNA-based switch. We believe our approach could offer a generalizable strategy for producing target-specific switches from a wide range of aptamers.

METTL3 enhances dentinogenesis differentiation of dental pulp stem cells via increasing GDF6 and STC1 mRNA stability

BACKGROUND

The dentinogenesis differentiation of dental pulp stem cells (DPSCs) is controlled by the spatio-temporal expression of differentiation related genes. RNA N6-methyladenosine (m⁶A) methylation, one of the most abundant internal epigenetic modification in mRNA, influences various events in RNA processing, stem cell pluripotency and differentiation. Methyltransferase like 3 (METTL3), one of the essential regulators, involves in the process of dentin formation and root development, while mechanism of METTL3-mediated RNA m⁶A methylation in DPSC dentinogenesis differentiation is still unclear.

METHODS

Immunofluorescence staining and MeRIP-seq were performed to establish m⁶A modification profile in dentinogenesis differentiation. Lentivirus were used to knockdown or overexpression of METTL3. The dentinogenesis differentiation was analyzed by alkaline phosphatase, alizarin red staining and real time RT-PCR. RNA stability assay was determined by actinomycin D. A direct pulp capping model was established with rat molars to reveal the role of METTL3 in tertiary dentin formation.

RESULTS

Dynamic characteristics of RNA m⁶A methylation in dentinogenesis differentiation were demonstrated by MeRIP-seq. Methyltransferases (METTL3 and METTL14) and demethylases (FTO and ALKBH5) were gradually up-regulated during dentinogenesis process. Methyltransferase METTL3 was selected for further study. Knockdown of METTL3 impaired the DPSCs dentinogenesis differentiation, and overexpression of METTL3 promoted the differentiation. METTL3-mediated m⁶A regulated the mRNA stabiliy of GDF6 and STC1. Furthermore, overexpression of METTL3 promoted tertiary dentin formation in direct pulp capping model.

CONCLUSION

The modification of m⁶A showed dynamic characteristics during DPSCs dentinogenesis differentiation. METTL3-mediated m⁶A regulated in dentinogenesis differentiation through affecting the mRNA stability of GDF6 and STC1. METTL3 overexpression promoted tertiary dentin formation in vitro, suggesting its promising application in vital pulp therapy (VPT).

[Effects of prenatal nicotine exposure on enamel formation of offspring mice]

Objective: To investigate the effects of nicotine on the morphology, structure of offspring's dental germ, enamel organ and other dental tissues and the further potential epigenetic mechanisms by establishing prenatal nicotine exposure mouse model. Methods: Ten C57BL/6 pregnant mice were randomly divided into control group (physiological saline subcutaneous injection) and prenatal nicotine exposure (PNE) group (nicotine subcutaneous injection) by using a random number table. Postnatal day 0 (P0), postnatal day 14 (P14) and postnatal day 25 (P25) offspring mice were collected for subsequent experiments. The offspring mice were divided into offspring control group and offspring PNE group according to the maternal group respectively. Weights of P0 and P25 offspring mice were recorded. Micro-CT, scanning electron microscope (SEM) and Vickers hardness test were performed to analyze the related parameters of hard tissues including alveolar bones and mandibular incisors. Total RNAs were extracted from mandible tissues and the third generation of dental epithelial stem cells (DESC) in P25 mice. The relative expression levels of osteogenic and ameloblastic differentiation related genes were measured by real-time quantitative PCR (RT-qPCR). Immunohistochemical stainings of paraffin sections were then performed to observe the distribution and expression level of proliferating cell nuclear antigen (Pcna), amelogenin (Amelx), histone H3 trimethylated at lysine 27 (H3K27me3) and enhancer of zeste homolog 2 (Ezh2). Cell counting kit-8 (CCK-8) assays were used to detect the cell viabilities of DESCs after administrations of different concentrations of nicotine (0.01, 0.1, 1 mmol/L) and GSK126 (an inhibitor of histone methyltransferase Ezh2). Results: Compared with the control group, pregnant mice in PNE group were more likely to have adverse pregnancy outcomes, such as significantly lower offspring body weight [P0: offspring control (1.20±0.04) g, offspring PNE (0.99±0.02) g, P<0.001; P25: offspring control (15.26±1.70) g, offspring PNE (9.65±1.32) g, P<0.001] and increased stillbirths rate [offspring control (0), offspring PNE (46.40±9.30) %, P<0.001]. At P14 and P25, the distance parameters between the enamel mineralized deposits of mandibular incisors and the mesial surface of the first molar in offspring PNE group [P14: (-1 349±45) μm; P25: (-1 192±147) μm] was significantly decreased compared with the control group [P14: (-506±380) μm, P25: (504±198) μm] (P<0.05, P<0.001). The enamel column and enamel column stroma of incisors in offspring PNE group were blurred, arranged loosely and disorderly than those in the control group, while the microhardness of incisor enamel in offspring PNE group [(245.7±18.4) MPa] was significantly lower compared to the control group [(371.9±28.7) MPa] (P<0.001). HE staining showed disordered pre-ameloblast (Pre-Am) arrangement and delayed mineralization deposition point in offspring PNE group compared with the control group, while the length of transit-amplifying cell (TA) and Pre-Am region were prolonged as well. Immunohistochemical staining results displayed that the overall Pcna (P<0.05), H3K27me3 (P<0.01), Ezh2 (P<0.01) expression of labial cervical loop (LaCL) in PNE group were increased, while the positive signal of Amelx in ameloblast cytoplasm was impaired. In vitro, the addition of 1 mmol/L nicotine could significantly upregulate the expression level of Pcna (P<0.01) and downregulate the expression levels of B lymphoma Mo-MLV insertion region 1 (P<0.05), leucine rich repeats and immunoglobulin like domains 1 (P<0.05), Amelx (P<0.01). In addition, 1 mmol/L nicotine could also significantly enhance the proliferation activity of DESCs (P<0.001). Addition of 10 μmol/L GSK126, could rescue the proliferation activation effect of 1 mmol/L nicotine on DESCs. Conclusions: PNE may delay the process of enamel formation and lineage differentiation, leading to the abnormal proliferation of DESCs and changes of epigenetic modification state in H3K27me3, which affect the development of enamel in offspring mice,suggesting PNE might be one of risk environmental factor for tooth development.

[Epigenetic regulation mechanism: roles in enamel formation and developmental defects of enamel]

Enamel formation is a series of complex physiological processes, which are regulated by critical genes spatially and temporally. These processes involve multiple developmental stages covering ages and are prone to suffer signal interference or gene mutations, ultimately leading to developmental defects of enamel (DDE). Epigenetic modifications have important regulatory roles in gene expression during enarnel development. New technologies including high-throughput sequencing, chromatin immunoprecipitation sequencing (ChIP-seq), and DNA methylation chip are emerging in recent years, making it possible to establish genome-wide epigenetic modification profiles during developmental processes. The regulatory role of epigenetic modification with spatio-temporal pattern, such as DNA methylation, histone modification and non-coding RNA, has significantly expanded our understanding of the regulatory network of enamel formation, providing a new theoretical basis of clinical management and intervention strategy for DDE. The present review briefly describes the enamel formation process of human beings' teeth as well as rodent incisors and summarizes the dynamic characteristics of epigenetic modification during enamel formation. The functions of epigenetic modification in enamel formation and DDE are also emphatically discussed.

Quantitatively deciphering the roles of sediment nitrogen removal in environmental and climatic feedbacks in two subtropical estuaries

Sedimentary denitrification and anaerobic ammonium oxidation (anammox) are two microbially-mediated nitrogen removal pathways with distinct climatic feedbacks. Estuaries receive large fluxes of anthropogenic nitrogen and serve as hotspots for nitrogen loss. Applying ¹⁵N isotope pairing technique and sediment intact core incubation in two subtropical estuaries, the Yangtze River Estuary (YRE) and Jiulong River Estuary (JRE), we show that denitrification predominates the sedimentary nitrogen loss with a minor contribution (8.6 ± 7.5%) from anammox. Particulate organic matter degradation sustains the sedimentary nitrogen removal linking the nitrogen transformations between water column and sediment. Our results indicate that estuarine sediments exhibit high areal nitrogen removal rate, but play a relatively weak role in eliminating the nitrogen inputted from river basin due to the limited area. The riverine excess nitrogen will eventually enter into the adjacent continental shelf and be removed via phytoplankton assimilation-sedimentation-degradation-coupled nitrification-denitrification. In addition, sedimentary denitrification causes 1.8 ± 2.2% of nitrogen flow towards nitrous oxide (N₂O) production and the derived N₂O release flux accounts for 59% and 65% of the daily sea-air N₂O emission in the YRE and JRE, respectively. These findings contribute to a better understanding of estuarine sedimentary nitrogen removal and associated climate feedbacks, and to the parameterization of Earth system models.

Effects of Dietary Essential Oils Supplementation on Egg Quality, Biochemical Parameters, and Gut Microbiota of Late-Laying Hens

The objective of this study was to explore the effects of adding essential oils (EO) to diets on egg quality, biochemical parameters and intestinal flora of late laying hens. The number of 252 Dawu Golden Phoenix laying hens (55 weeks old) were randomly sorted into two groups: the control group (CG) fed a basal diet and the EO group fed a basal diet with 300 mg/kg of essential oils. The average egg weight, feed-to-egg ratio, and egg production rate were determined every week. The trial started at week 55 and lasted for 8 weeks. During the experiment’s last week, 36 eggs out of each group were chosen at random to test. In our study, dietary supplementation with EO considerably decreased the egg breaking rate (p = 0.01) and increased the shell-breaking strength (p = 0.04). The treatment group’s alanine aminotransferase (ALT) levels were considerably lower than those of the control group (p = 0.03). The EO group had substantially higher total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD) (p = 0.04 and p =0.03, respectively). However, there were no differences in alpha diversity indicators between the two groups. It is worth noting that Firmicutes were increased considerably (p < 0.05), while Spirochaetota and Proteobacteria were significantly reduced in the EO group. At genus levels, the EO supplementation increased the relative abundance of Intestinimonas (p < 0.05) and Megamonas (p < 0.01). In conclusion, a dietary supplementation of 300 mg/kg EO can improve the production performance of laying hens and the egg quality. It can also regulate the abundance of cecal flora and serum biochemical indicators.

Epigenetic controls of Sonic hedgehog guarantee fidelity of epithelial adult stem cells trajectory in regeneration

Given that adult stem cells (ASCs) fuel homeostasis and healing by providing tissue-specific descendants, the fidelity of ASC fate determination is crucial for regeneration. Here, we established that an epigenetic control of epithelial ASC fate fidelity via Ezh2/H3K27me3 was indispensable for incisor homeostasis and regeneration. Mechanistically, in homeostasis, H3K27me3 upstream occupies the Sonic hedgehog (Shh) promoter to directly restrain Shh expression, thereby precisely confining Shh expression. When injury occurred, Ezh2/H3K27me3 was substantially induced within inner enamel epithelium and preameloblast zones, and such epigenetic response guaranteed the fidelity of ASC commitment via pulling injury-increased Shh back to homeostatic levels, utterly underlying regeneration progression. Once losing H3K27me3-dependent restriction of Shh expression through the Cre-Loxp system totally disrupted lineage commitment and stemness exhaustion, and abolished hard tissue regeneration emerged in vivo. We next uncovered the molecular mechanisms by which injury-induced Ezh2 mediated the spatiotemporal dynamics of H3K27me3 to repress Shh expression, thus epigenetically deciding ASC fate.

PTHrP promotes subchondral bone formation in TMJ-OA

PTH-related peptide (PTHrP) improves the bone marrow micro-environment to activate the bone-remodelling, but the coordinated regulation of PTHrP and transforming growth factor-β (TGFβ) signalling in TMJ-OA remains incompletely understood. We used disordered occlusion to establish model animals that recapitulate the ordinary clinical aetiology of TMJ-OA. Immunohistochemical and histological analyses revealed condylar fibrocartilage degeneration in model animals following disordered occlusion. TMJ-OA model animals administered intermittent PTHrP (iPTH) exhibited significantly decreased condylar cartilage degeneration. Micro-CT, histomorphometry, and Western Blot analyses disclosed that iPTH promoted subchondral bone formation in the TMJ-OA model animals. In addition, iPTH increased the number of osterix (OSX)-positive cells and osteocalcin (OCN)-positive cells in the subchondral bone marrow cavity. However, the number of osteoclasts was also increased by iPTH, indicating that subchondral bone volume increase was mainly due to the iPTH-mediated increase in the bone-formation ability of condylar subchondral bone. In vitro, PTHrP treatment increased condylar subchondral bone marrow-derived mesenchymal stem cell (SMSC) osteoblastic differentiation potential and upregulated the gene and protein expression of key regulators of osteogenesis. Furthermore, we found that PTHrP-PTH1R signalling inhibits TGFβ signalling during osteoblastic differentiation. Collectively, these data suggested that iPTH improves OA lesions by enhancing osteoblastic differentiation in subchondral bone and suppressing aberrant active TGFβ signalling. These findings indicated that PTHrP, which targets the TGFβ signalling pathway, may be an effective biological reagent to prevent and treat TMJ-OA in the clinic.

[Identification and preservation of arm lymphatics in axillary lymph node dissection to prevent arm lymphedema: a single center randomized controlled trial]

Objective: To evaluate the feasibility of identification and preservation of arm lymphatics (DEPART) in axillary lymph node dissection (ALND) for breast cancer to prevent arm lymphedema. Methods: A randomized controlled study method was used. Two hundred and sixty-five patients who underwent breast cancer surgery at the Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University from November 2017 to June 2018 were included, and the patients were randomly divided into ALND+ DEPART group (132 patients) and standard ALND group (133 patients) by random number table method. In the ALND+ DEPART group, indocyanine green and methylene blue were injected as tracers before surgery, and the arm sentinel nodes was visualized by staged tracing during intraoperative dissection of axillary lymph nodes. Partial frozen sections were made of arm lymph nodes >1 cm in length and hard and suspicious of metastasis, and arm lymph nodes and lymphatic vessels were selectively preserved. Patients in the standard ALND group underwent standard ALND. Objective and subjective indexes of arm lymphedema were evaluated by 5-point circumference measurement and Norman questionnaire. Results: Among 132 breast cancer patients in the ALND+ DEPART group, 121 (91.7%) completed DEPART. There were no statistically significant differences in age, body mass index, pathological type, dissection number of axillary lymph node, N stage, TNM stage, molecular typing, and regional radiotherapy between the ALND+ DEPART and standard ALND groups (P>0.05). At a median follow-up of 24 months, assessment by the 5-point circumference measurement showed that the incidence rates of lymphedema in the ALND+ DEPART and standard ALND groups were 5.0% (6/121) and 15.8% (21/133), respectively, with statistically significant differences (P=0.005). Assessment by the Norman questionnaire showed that the incidence rates of lymphedema in the ALND+ DEPART and standard ALND groups were 5.8% (7/121) and 21.8% (29/133), respectively, with a statistically significant difference (P<0.001). No local regional recurrence was observed in either group during the follow-up period. Conclusion: For breast cancer patients with positive axillary lymph nodes, the administration of DEPART during ALND can reduce or avoid the occurrence of arm lymphedema without compromising oncology safety.

Effects of Dietary Glycerol Monobutyrate Supplementation on Egg Performance, Biochemical Indices, and Gut Microbiota of Aged Hens

This experiment aimed to determine the effect of dietary supplementation with glycerol monobutyrate (GMB) on egg-laying performance, biochemical indicators, and gut microflora at the late stage of laying hens. A total of 252 healthy Dawu Golden Phoenix laying hens with no difference in body weight were selected and randomly divided into two groups: (1) control group (CG), corn-soybean meal diet, (2) 500 mg glycerol monobutyrate/kg added to the basal diet. Six replicates were set up for each treatment group, with 21 birds per replicate. The trial started at week 55 and lasted for 8 weeks. Compared to the control group, the supplementation with GMB increased egg weight (P = 0.03), shell thickness (P = 0.03) and decreased egg breaking rate (P = 0.04). There was no significant difference in egg production rate, feed-to-egg ratio, egg shape index, eggshell strength, and Haugh unit between the two groups. In addition, dietary GMB decreased the levels of aspartate aminotransferase (P = 0.03) and total bilirubin (P = 0.02) in serum, and increased total antioxidant capacity (P = 0.03) and total superoxide dismutase (P = 0.02). However, alpha diversity indices (Ace, Chao1, Shannon, Simpson, goods_coverage, and PD_whole tree) were not different between the two groups. Notably, dietary GMB significantly decreased the abundances of Proteobacteria at the phylum level and the abundances of Enterobacter at the genus level (P &lt; 0.01), but there was no significant difference in the composition of other cecal microbiota. In summary, the present study revealed that supplementation with 500 mg/kg glycerol monobutyrate improved egg weight, eggshell quality, and antioxidant capacity in serum, but its effect on cecal microbiota composition was limited.

A Grip Strength Estimation Method Using a Novel Flexible Sensor under Different Wrist Angles

It is a considerable challenge to realize the accurate, continuous detection of handgrip strength due to its complexity and uncertainty. To address this issue, a novel grip strength estimation method oriented toward the multi-wrist angle based on the development of a flexible deformation sensor is proposed. The flexible deformation sensor consists of a foaming sponge, a Hall sensor, an LED, and photoresistors (PRs), which can measure the deformation of muscles with grip strength. When the external deformation squeezes the foaming sponge, its density and light intensity change, which is detected by a light-sensitive resistor. The light-sensitive resistor extended to the internal foaming sponge with illuminance complies with the extrusion of muscle deformation to enable relative muscle deformation measurement. Furthermore, to achieve the speed, accuracy, and continuous detection of grip strength with different wrist angles, a new grip strength-arm muscle model is adopted and a one-dimensional convolutional neural network based on the dynamic window is proposed to recognize wrist joints. Finally, all the experimental results demonstrate that our proposed flexible deformation sensor can accurately detect the muscle deformation of the arm, and the designed muscle model and convolutional neural network can continuously predict hand grip at different wrist angles in real-time.

Phenotype and molecular characterizations of a family with dentinogenesis imperfecta shields type II with a novel DSPP mutation

Background

Dentinogenesis imperfecta (DGI), Shields type-II is an autosomal dominant genetic disease which severely affects the function of the patients’ teeth. The dentin sialophosphoprotein (DSPP) gene is considered to be the pathogenic gene of DGI-II. In this study, a DGI-II family with a novel DSPP mutation were collected, functional characteristics of DGI cells and clinical features were analyzed to better understand the genotype-phenotype relationship of this disease.

Methods

Clinical data were collected, whole exome sequencing (WES) was conducted, and Sanger sequencing was used to verify the mutation sites. Physical characteristics of the patient’s teeth were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The localization of green fluorescent protein (GFP)-fused wild-type (WT) dentin sialoprotein (DSP) and its variant were evaluated via an immunocytochemistry (ICC) assay. The behaviors of human dental pulp stem cells (hDPSCs) were investigated by flow cytometry, osteogenic differentiation, and quantitative real-time polymerase chain reaction (qRT-PCR).

Results

A novel heterozygous mutation c.53T > G (p. Val18Gly) in DSPP was found in this family. The SEM results showed that the participants’ teeth had reduced and irregular dentinal tubes. The EDS results showed that the Ca/P ratio of the patients’ teeth was significantly higher than that of the control group. The ICC assay showed that the mutant DSP was entrapped in the endoplasmic reticulum (ER), while the WT DSP located mainly in the Golgi apparatus. In comparison with normal cells, the patient’s cells exhibited significantly decreased mineralization ability and lower expression levels of DSPP and RUNX2.

Conclusions

The c.53T > G (p. Val18Gly) DSPP variant was shown to present with rare hypoplastic enamel defects. Functional analysis revealed that this novel variant disturbs dentinal characteristics and pulp cell behavior.

The Role of TNF-α in the Pathogenesis of Temporomandibular Disorders

Temporomandibular disorder (TMD) is an oral dentofacial disease that is related to multiple factors such as disordered dental occlusion, emotional stress, and immune responses. In the past decades, tumor necrosis factor-alpha (TNF-α), a pleiotropic cytokine, has provided valuable insight into the pathogenesis of TMD, particularly in settings associated with inflammation. It is thought that TNF-α participates in the pathogenesis of TMD by triggering immune responses, deteriorating bone and cartilage, and mediating pain in the temporomandibular joint (TMJ). Initially, TNF-α plays the role of "master regulator" in the complex immune network by increasing or decreasing the production of other inflammatory cytokines. Then, the effects of TNF-α on cells, particularly on chondrocytes and synovial fibroblasts, result in pathologic cartilage degradation in TMD. Additionally, multiple downstream cytokines induced by TNF-α and neuropeptides can regulate central sensitization and inflammatory pain in TMD. Previous studies have also found some therapies target TMD by reducing the production of TNF-α or blocking TNF-α-induced pathways. All this evidence highlights the numerous associations between TNF-α and TMD; however, they are currently not fully understood and further investigations are still required for specific mechanisms and treatments targeting specific pathways. Therefore, in this review, we explored general mechanisms of TNF-α, with a focus on molecules in TNF-α-mediated pathways and their potential roles in TMD treatment. In view of the high clinical prevalence rate of TMD and damage to patients' QOL, this review provides adequate evidence for studying links between inflammation and TMD in further research and investigation.

Genome-wide identification of Gramineae histone modification genes and their potential roles in regulating wheat and maize growth and stress responses

BACKGROUND

In plants, histone modification (HM) genes participate in various developmental and defense processes. Gramineae plants (e.g., Triticum aestivum, Hordeum vulgare, Sorghum bicolor, Setaria italica, Setaria viridis, and Zea mays) are important crop species worldwide. However, little information on HM genes is in Gramineae species.

RESULTS

Here, we identified 245 TaHMs, 72 HvHMs, 84 SbHMs, 93 SvHMs, 90 SiHMs, and 90 ZmHMs in the above six Gramineae species, respectively. Detailed information on their chromosome locations, conserved domains, phylogenetic trees, synteny, promoter elements, and gene structures were determined. Among the HMs, most motifs were conserved, but several unique motifs were also identified. Our results also suggested that gene and genome duplications potentially impacted the evolution and expansion of HMs in wheat. The number of orthologous gene pairs between rice (Oryza sativa) and each Gramineae species was much greater than that between Arabidopsis and each Gramineae species, indicating that the dicotyledons shared common ancestors. Moreover, all identified HM gene pairs likely underwent purifying selection based on to their non-synonymous (Ka)/synonymous (Ks) nucleotide substitutions. Using published transcriptome data, changes in TaHM gene expression in developing wheat grains treated with brassinosteroid, brassinazole, or activated charcoal were investigated. In addition, the transcription models of ZmHMs in developing maize seeds and after gibberellin treatment were also identified. We also examined plant stress responses and found that heat, drought, salt, insect feeding, nitrogen, and cadmium stress influenced many TaHMs, and drought altered the expression of several ZmHMs. Thus, these findings indicate their important functions in plant growth and stress adaptations.

CONCLUSIONS

Based on a comprehensive analysis of Gramineae HMs, we found that TaHMs play potential roles in grain development, brassinosteroid- and brassinazole-mediated root growth, activated charcoal-mediated root and leaf growth, and biotic and abiotic adaptations. Furthermore, ZmHMs likely participate in seed development, gibberellin-mediated leaf growth, and drought adaptation.

[Lesion removal plus whole breast exploration and washing plus micro-plastic procedures in the treatment of granulomatous lobular mastitis: a randomized controlled study]

Objective: To examine the effect of"lesion removal plus whole breast exploration and washing plus micro-plastic surgery"in granulomatous lobular mastitis. Methods: A single-center prospective randomized controlled study method was used to enroll patients diagnosed with granulomatous lobular mastitis for whom surgical procedures were projected from March 2017 to September 2019 at Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University. The sample size is determined by the superiority test. Based on the literatures and the previous work, the two groups require 97 cases. Fifty-two patients underwent"lesion removal+whole breast exploration and washing plus micro-plastic surgery"(observation group). Forty-five cases underwent"empirical breast lesion resection plus fascia tissue flap plasty plus nipple and areola correction"(control group). The primary study endpoint is the recurrence rate, and the secondary study endpoints include surgical complications, incision healing time, and postoperative patient satisfaction. Independent sample t test, Wilcoxon rank-sum test, χ² test and Fisher exact test were used for comparison between groups. Results: All procedures were completed successful, with no severe complications. All patients were followed up for (15.2±1.9) months (range: 12 to 24 months). There were no significant differences in incidence of postoperative complications (7.7% (4/52) vs. 6.7%(3/45), P=1), drainage time ((8.6±0.6) days vs. (8.4±0.8) days, t=1.921, P=0.053) and hospital stay ((7.7±0.6) days vs. (7.6±0.5) days, t=1.633, P=0.102) between the two groups. The recurrence rate of the observation group was lower significantly than that of the control group (3.8% (2/52) vs. 24.4%(11/45), χ²=8.819, P=0.003). The observation group had better cosmetic effects (Z=-2.657, P=0.008) and patient satisfaction than control group (Z=-5.730, P=0.000). Conclusion: The "lesion removal plus whole breast exploration and flushing plus micro-plastic surgery" has a good therapeutic effect and cosmetic value for patients with refractory granulomatous lobular mastitis.

[Application value of intraoperative neuromonitoring plus "classification of EBSLN" to protect the external branch of the superior laryngeal nerve]

Objective: To investigate the application efficacy of the "classification of external branch of superior laryngeal nerve (EBSLN)" combined with intraoperative neuromonitoring (IONM) in the dissection of EBSLN for protecting the nerve from injuery, compared with ligation of branches of the superior thyroid vessels without attempts to visually identify the nerve. Methods: A prospective randomized controled study was performed in our center. Patients subjected to thyroidectomy from January 2017 to June 2019 were randomly divided into 2 groups, patients in experimental group underwent thyroidectomy and "classification of EBSLN" with IONM to dissect EBSLN, and patients in control group received synchronous surgery without attempts to visually identify the nerve. The anatomical subtypes of EBSLN in experimental group were recorded. The voice handicap index 10 (VHI-10) score was evaluated and the movement of bilateral vocal cords was examined by laryngoscope before surgery, 1 month, 3 months, and 6 months after surgery, respectively. SPSS 26.0 statistical software was used for statistical analysis. Results: Among the 1 377 EBSLN from 827 patients (317 males and 510 females, aged 24-58 years old), 691 EBSLNs in experimental group and 686 EBSLNs in control group. Totally 98.3% of EBSLNs in experimental group were identified by IONM including 16.4% (113/691) for type Ⅰ, 21.3% (147/691) for type Ⅱa, 31.4% (217/691) for type Ⅱb, 10.4% (72/691) for type Ⅲa, 3.9% (27/691) for type Ⅲb, 16.6% (115/691) for type Ⅲc. There was no statistical significance difference in baseline data between 2 groups (all P>0.05). All patients were followed up for more than 6 months. The postoperative nerve injury rate of experimental group was significantly lower than that of control group (1.2% vs. 7.5%, χ²=12.659, P<0.001), and the VHI-10 scores and laryngoscope results of experimental group were better than those of control group in three follow-up visits (P<0.001). With postoperative laryngoscope examination, 3 patients in the experimental group and 23 patients in the control group showed vocal cord relaxation, bilateral oblique asymmetry and other phenomena, which were considered as the results of permanent injury. Other patients with symptoms were relieved to varying degrees during the follow-up, and their symptoms were considered as the results of temporary injury. Conclusion: IONM combined with "classification of EBSLN" can reduce significantly the risk of EBSLN injury in thyroidectomy, which is better than direct ligation of branches without attempts to visually identify the nerve.

[Parathyroid hormone assay with eluent of aspirated tissues in parathyroidectomy]

Objective: To explore the values of intraoperative fine-needle aspiration (IFNA) and parathyroid hormone (PTH) detection in the eluate of aspirated tissue during parathyroidectomy. Methods: Fifty-four patients with secondary hyperparathyroidism (SHPT) including 24 males and 30 females, aged 20-83 years, admitted to Zhongnan Hospital of Wuhan University from January 2019 to October 2019, were included. All patients received subtotal parathyroidectomy with autologous transplantation, during surgery, IFNA and PTH detection in the eluate of aspirated tissue were performed, and also routine postoperative pathological examination was performed. The results of PTH detection in the eluate of aspirated tissue and postoperative pathological examinations were compared and analyzed by SPSS and R software for evaluating of the sensitivity, specificity, positive predictive value, negative predictive value, misdiagnosis rate, missed diagnosis and accuracy. Results: Surgery was completed successfully in all patients. After surgery, the symptoms were improved in the patients except two who were asymptomatic. None had any serious postoperative complications such as hypocalcaemia or hoarseness. A total of 231 aspirated tissue samples were tested, of which 216 were identified as parathyroid and 15 non-parathyroid based on intraoperative PTH detection in tissue eluate; while 217 were confirmed as parathyroid tissues and 14 non-parathyroid tissues with postoperative pathological examinations. The specificity and sensitivity of intraoperative IFNA and PTH detection in tissue eluate for identifying parathyroid tissues were 99.5% and 100.0%, respectively. Conclusion: The IFNA and PTH detection in tissue eluate is a rapid, simple, and accurate procedure, which helps the surgeon to identify parathyroid tissue and to ensure the endocrine activity of preserved or autografted parathyroid tissue during parathyroidectomy.

Probiotics ameliorate alveolar bone loss by regulating gut microbiota

OBJECTIVES

Oestrogen deficiency is an aetiological factor of postmenopausal osteoporosis (PMO), which not only decreases bone density in vertebrae and long bone but also aggravates inflammatory alveolar bone loss. Recent evidence has suggested the critical role of gut microbiota in osteoimmunology and its influence on bone metabolisms. The present study aimed to evaluate the therapeutic effects of probiotics on alveolar bone loss under oestrogen-deficient condition.

MATERIALS AND METHODS

Inflammatory alveolar bone loss was established in ovariectomized (OVX) rats, and rats were daily intragastrically administered with probiotics until sacrifice. Gut microbiota composition, intestinal permeability, systemic immune status and alveolar bone loss were assessed to reveal the underlying correlation between gut microbiota and bone metabolisms.

RESULTS

We found administration of probiotics significantly prevented inflammatory alveolar bone resorption in OVX rats. By enriching butyrate-producing genera and enhancing gut butyrate production, probiotics improved intestinal barrier and decreased gut permeability in the OVX rats. Furthermore, the oestrogen deprivation-induced inflammatory responses were suppressed in probiotics-treated OVX rats, as reflected by reduced serum levels of inflammatory cytokines and a balanced distribution of CD4+ IL-17A+ Th17 cells and CD4+ CD25+ Foxp3+ Treg cells in the bone marrow.

CONCLUSIONS

This study demonstrated that probiotics can effectively attenuate alveolar bone loss by modulating gut microbiota and further regulating osteoimmune response and thus represent a promising adjuvant in the treatment of alveolar bone loss under oestrogen deficiency.

Defects of cohesin loader lead to bone dysplasia associated with transcriptional disturbance

Cohesin loader nipped-B-like protein (Nipbl) is increasingly recognized for its important role in development and cancer. Cornelia de Lange Syndrome (CdLS), mostly caused by heterozygous mutations of Nipbl, is an autosomal dominant disease characterized by multiorgan malformations. However, the regulatory role and underlying mechanism of Nipbl in skeletal development remain largely elusive. In this study, we constructed a Nipbl-a Cas9-knockout (KO) zebrafish, which displayed severe retardation of global growth and skeletal development. Deficiency of Nipbl remarkably compromised cell growth and survival, and osteogenic differentiation of mammalian osteoblast precursors. Furthermore, Nipbl depletion impaired the cell cycle process, and caused DNA damage accumulation and cellular senescence. In addition, nucleolar fibrillarin expression, global rRNA biogenesis, and protein translation were defective in the Nipbl-depleted osteoblast precursors. Interestingly, an integrated stress response inhibitor (ISRIB), partially rescued Nipbl depletion-induced cellular defects in proliferation and apoptosis, osteogenesis, and nucleolar function. Simultaneously, we performed transcriptome analysis of Nipbl deficiency on human neural crest cells and mouse embryonic fibroblasts in combination with Nipbl ChIP-Seq. We found that Nipbl deficiency caused thousands of differentially expressed genes including some important genes in bone and cartilage development. In conclusion, Nipbl deficiency compromised skeleton development through impairing osteoblast precursor cell proliferation and survival, and osteogenic differentiation, and also disturbing the expression of some osteogenesis-regulatory genes. Our study elucidated that Nipbl played a pivotal role in skeleton development, and supported the fact that treatment of ISRIB may provide an early intervention strategy to alleviate the bone dysplasia of CdLS.

Genome-wide identification of Brassicaceae B-BOX genes and molecular characterization of their transcriptional responses to various nutrient stresses in allotetraploid rapeseed

BACKGROUND

B-box (BBX) genes play important roles in plant growth regulation and responses to abiotic stresses. The plant growth and yield production of allotetraploid rapeseed is usually hindered by diverse nutrient stresses. However, no systematic analysis of Brassicaceae BBXs and the roles of BBXs in the regulation of nutrient stress responses have not been identified and characterized previously.

RESULTS

In this study, a total of 536 BBXs were identified from nine brassicaceae species, including 32 AtBBXs, 66 BnaBBXs, 41 BoBBXs, 43 BrBBXs, 26 CrBBXs, 81 CsBBXs, 52 BnBBXs, 93 BjBBXs, and 102 BcBBXs. Syntenic analysis showed that great differences in the gene number of Brassicaceae BBXs might be caused by genome duplication. The BBXs were respectively divided into five subclasses according to their phylogenetic relationships and conserved domains, indicating their diversified functions. Promoter cis-element analysis showed that BBXs probably participated in diverse stress responses. Protein-protein interactions between BnaBBXs indicated their functions in flower induction. The expression profiles of BnaBBXs were investigated in rapeseed plants under boron deficiency, boron toxicity, nitrate limitation, phosphate shortage, potassium starvation, ammonium excess, cadmium toxicity, and salt stress conditions using RNA-seq data. The results showed that different BnaBBXs showed differential transcriptional responses to nutrient stresses, and some of them were simultaneously responsive to diverse nutrient stresses.

CONCLUSIONS

Taken together, the findings investigated in this study provided rich resources for studying Brassicaceae BBX gene family and enriched potential clues in the genetic improvement of crop stress resistance.

Probiotic Streptococcus salivarius K12 Alleviates Radiation-Induced Oral Mucositis in Mice

Background

Oral mucositis is the most common oral complication of cancer patients receiving radiotherapy and/or chemotherapy, leading to poor quality of life. Limitations of the current interventions on radiation-induced oral mucositis (RIOM) urge the development of novel therapeutics. Here, we evaluated the treatment outcome of probiotic Streptococcus salivarius K12 on RIOM mice, and oral microbiota that is associated with the progress of RIOM was further investigated.

Methods

An experimental RIOM mouse model was established, and S. salivarius K12 was applied to the mouse oral cavity daily. Histological analyses were performed to evaluate the severity of oral mucositis and the treatment outcome of S. salivarius K12. The oral microbiota of mice was further analyzed by 16S rRNA sequencing, microbial culture and qPCR.

Results

Irradiation induced conspicuous mucositis in the oral cavity of mice. S. salivarius K12 treatment was beneficial for the healing of RIOM, as reflected by reduced ulcer size, increased basal layer epithelial cellularity and mucosal thickness, and elevated epithelial proliferation and attenuated apoptosis. RIOM mice presented significant oral microbial dysbiosis, with an overgrowth of oral anaerobes. S. salivarius K12 treatment reconstituted the oral microbiota and decreased the abundance of oral anaerobes of RIOM mice. In addition, S. salivarius K12 treatment inhibited NI1060 in Pasteurella genus and downregulated the expression of nitrate reductase.

Conclusions

S. salivarius K12 treatment can alleviate RIOM and reconstituted the dysbiotic oral microbiota in mice. S. salivarius K12 may represent a promising adjuvant treatment to improve the quality of life of cancer patients receiving radiotherapy.

Roles of Dental Mesenchymal Stem Cells in the Management of Immature Necrotic Permanent Teeth

Dental caries and trauma always lead to pulp necrosis and subsequent root development arrest of young permanent teeth. The traditional treatment, apexification, with the absence of further root formation, results in abnormal root morphology and compromises long-term prognosis. Regeneration endodontics procedures (REPs) have been developed and considered as an alternative strategy for management of immature permanent teeth with pulpal necrosis, including cell-free and cell-based REPs. Cell-free REPs, including revascularization and cell homing with molecules recruiting endogenous mesenchymal stem cells (MSCs), have been widely applied in clinical treatment, showing optimistic periapical lesion healing and continued root development. However, the regenerated pulp-dentin complex is still absent in these cases. Dental MSCs, as one of the essentials of tissue engineering, are vital seed cells in regenerative medicine. Dental MSC-based REPs have presented promising potential with pulp-dentin regeneration in large animal studies and clinical trials via cell transplantation. In the present review, we summarize current understanding of the biological basis of clinical treatments for immature necrotic permanent teeth and the roles of dental MSCs during this process and update the progress of MSC-based REPs in the administration of immature necrotic permanent teeth.

Genome-Wide Identification of Brassinosteroid Signaling Downstream Genes in Nine Rosaceae Species and Analyses of Their Roles in Stem Growth and Stress Response in Apple

Brassinosteroid signaling downstream genes regulate many important agronomic traits in rice. However, information on such genes is limited in Arabidopsis and Rosaceae species. We identified these genes in Arabidopsis and nine Rosaceae species. They were, respectively, named based on chromosomal locations. Segmental duplication and whole-genome duplication under purifying selection, as determined by Ka/Ks analysis, likely contributed to Rosaceae gene expansion. Apple (Malus domestica), Arabidopsis, and rice genes were generally similar, while several Rosaceae genes differed from their rice homologs in various characteristics, such as gene length, subcellular localization, transmembrane topology, conserved domains, secondary structures, and responses to external signals. The brassinosteroid downstream genes in apple were, respectively, induced or repressed by five phytohormones. Furthermore, these apple downstream genes were differentially expressed in different apple grafting combinations (“Nagafu No. 2”/“Malling 9” and “Nagafu No. 2”/“Nagafu No. 2”) and long–short shoot varieties (“Yanfu No. 6” and “Nagafu No. 2”). Responses of the MdBZR genes to diverse stress signals were examined and candidate hub genes were identified. These findings indicated that several brassinosteroid signaling downstream genes in Rosaceae functionally differed from their rice homologs, and certain apple genes may play roles in plant height and stress responses. This study provided valuable information and presented enriched biological theories on brassinosteroid signaling downstream genes in apple. Identification of such genes serve to help expand apple breeding and growth. This study provides useful information for brassinosteroid signaling downstream genes.

The alteration of A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) in the knee joints of osteoarthritis mice

The A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) family is gradually being recognized as an important family of mediators that, along with the matrix metalloproteinases (MMPs), control the degradation process in osteoarthritis (OA). The objective of this study was to uncover the detailed alterations of ADAMTS1, ADAMTS2, and ADAMTS5 in the knee joint of OA mice. The OA model was established by anterior cruciate ligament transection (ACLT) on the knee joints of C57BL/6 J mice. The mice showed representative phenotypes of ACLT-induced OA, including obvious deterioration of the cartilage, reductions in the collagen and proteoglycan components in the cartilage matrix of OA mice, and increased inflammation and osteoclast activity. By qPCR, the gene expression levels of Adamts1, -2, and -5 were the top-ranked among Adamts1-5 in cartilage/chondrocytes, osteogenic tissue/osteoblasts, and cortical bone/osteocytes. Moreover, the protein expression levels of ADAMTS1, -2, and -5 were all increased in articular cartilage, the growth plate, and subchondral bone of the knee joint. The results suggest the important roles of ADAMTS1, -2, and -5 in OA disease, which will be helpful in further research on degenerative changes in OA.

[Effects of different application methods of Bacillus subtilis agent on soil microbial diversity and growth of muskmelon]

Continuous planting of muskmelon and excessive application of chemical fertilizers have caused a series of problems, such as imbalance of the soil micro-ecological environment, serious soil-borne diseases and yield loss. Application of Bacillus subtilis agent is an important way to improve soil micro-ecological environment, prevent soil-borne diseases, and promote plant growth. In this study, B. subtilis was used as experimental agent to analyze the effects of different application methods on the soil microbial diversity and growth of muskmelon in greenhouse. The number of culturable microorganisms in soil was measured by dilution-plate method. The diversity of soil uncultivated microorganisms was determined by Illumina Miseq sequencing technology. The yield of muskmelon was measured by weighing method. The number of culturable bacteria in the root irrigation, hole application and dipping root application groups was higher than that of the control in different muskmelon growth stages, but there was no significant difference among the three different application methods. The number of soil fungi from B. subtilis agent treatment groups in flowering stage was significantly lower in comparison to the control group. However, B. subtilis agent treatment did not cause significant difference on soil fungi number at the fruiting and pulling stage. Diversity analysis of uncultured microorganisms showed that the Shannon index values of bacteria were higher and Simpson index values were lower respectively in the three B. subtilis treatment groups than that in the control. Moreover, the dipping root treatment produced the lowest Shannon index value and the highest Simpson index value of fungi. NMDS and cluster analysis showed that B. subtilis agents dipping root treatment significantly affected the bacterial and fungal flora, both of which were clustered into one independent branch. The application of B. subtilis agents, especially dipping root treatment, significantly decreased the abundance of Bacteroidetes, increased the abundance of Actinobacteria and Acidobacteria. The B. subtilis agent treatment didn't produce significant effect on the diversity of fungal flora except Chytridiomycota. The height, stem diameter and leaf area of muskmelon increased by applying B. subtilis agents, and dipping root treatment produced the most significant effect. As a new type of environmental protection fertilizer, B. subtilis agent can increase the number of soil culturable microorganisms, improve soil microbial diversity, and promote growth and yield. This study would provide a scientific basis for the rational application of B. subtilis.

Independent Generation and Time-Resolved Detection of 2'-Deoxyguanosin-N2-yl Radicals

Guanine radicals are important reactive intermediates in DNA damage. Hydroxyl radical (HO. ) has long been believed to react with 2'-deoxyguanosine (dG) generating 2'-deoxyguanosin-N1-yl radical (dG(N1-H). ) via addition to the nucleobase π-system and subsequent dehydration. This basic tenet was challenged by an alternative mechanism, in which the major reaction of HO. with dG was proposed to involve hydrogen atom abstraction from the N2-amine. The 2'-deoxyguanosin-N2-yl radical (dG(N2-H). ) formed was proposed to rapidly tautomerize to dG(N1-H). . We report the first independent generation of dG(N2-H). in high yield via photolysis of 1. dG(N2-H). is directly observed upon nanosecond laser flash photolysis (LFP) of 1. The absorption spectrum of dG(N2-H). is corroborated by DFT studies, and anti- and syn-dG(N2-H). are resolved for the first time. The LFP experiments showed no evidence for tautomerization of dG(N2-H). to dG(N1-H). within hundreds of microseconds. This observation suggests that the generation of dG(N1-H). via dG(N2-H). following hydrogen atom abstraction from dG is unlikely to be a major pathway when HO. reacts with dG.

Biomaterial Stiffness Guides Cross-talk between Chondrocytes: Implications for a Novel Cellular Response in Cartilage Tissue Engineering

The exquisite cartilage architecture maintains an orderly dynamic equilibrium as a result of the interplay between chondrocyte functions and the unique extracellular matrix (ECM) microenvironment. Numerous studies have demonstrated that extracellular cues, including topological, mechanical, and biochemical properties of the underlying substrates, dictate the chondrocyte behaviors. Consequently, developing advanced biomaterials with the desired characteristics which could achieve the biointerface between cells and the surrounded matrix close to the physiological conditions becomes a great hotspot in bioengineering. However, how the substrate stiffness influences the intercellular communication among chondrocytes is still poorly reported. We used polydimethylsiloxane with varied stiffnesses as a cell culture substrate to elucidate a novel cell-to-cell communication in a collective of chondrocytes. First, morphological images collected using scanning electron microscopy revealed that the tunable substrate stiffnesses directed the changes in intercellular links among chondrocytes. Next, fibronectin, which played a vital role in the connection of ECM components or linkage of ECM to chondrocytes, was shown to be gathered along cell-cell contact areas and was changed with the tunable substrate stiffnesses. Furthermore, transmembrane junctional proteins including connexin 43 (Cx43) and pannexin 1 (Panx1), which are responsible for gap junction formation in cell-to-cell communication, were mediated by the tunable substrate stiffnesses. Finally, through a scrape loading/dye transfer assay, we revealed cell-to-cell communication changes in a living chondrocyte population in response to the tunable substrate stiffnesses via cell-to-cell fluorescent molecule transport. Taken together, this novel cell-to-cell communication regulated by biomaterial stiffness could help us to increase the understanding of cell behaviors under biomechanical control and may ultimately lead to refining cell-based cartilage tissue engineering.

Berberine mediates root remodeling in an immature tooth with apical periodontitis by regulating stem cells from apical papilla differentiation

Once pulp necrosis or apical periodontitis occurs on immature teeth, the weak root and open root apex are challenging to clinicians. Berberine (BBR) is a potential medicine for bone disorders, therefore, we proposed to apply BBR in root canals to enhance root repair in immature teeth. An in vivo model of immature teeth with apical periodontitis was established in rats, and root canals were filled with BBR, calcium hydroxide or sterilized saline for 3 weeks. The shape of the roots was analyzed by micro-computed tomography and histological staining. In vitro, BBR was introduced into stem cells from apical papilla (SCAPs). Osteogenic differentiation of stem cells from apical papilla was investigated by alkaline phosphatase activity, mineralization ability, and gene expression of osteogenic makers. The signaling pathway, which regulated the osteogenesis of SCAPs was evaluated by quantitative real time PCR, Western blot analysis, and immunofluorescence. In rats treated with BBR, more tissue was formed, with longer roots, thicker root walls, and smaller apex diameters. In addition, we found that BBR promoted SCAPs osteogenesis in a time-dependent and concentration-dependent manner. BBR induced the expression of β-catenin and enhanced β-catenin entering into the nucleus, to up-regulate more runt-related nuclear factor 2 downstream. BBR enhanced root repair in immature teeth with apical periodontitis by activating the canonical Wnt/β-catenin pathway in SCAPs.

Gap junction-mediated cell-to-cell communication in oral development and oral diseases: a concise review of research progress

Homoeostasis depends on the close connection and intimate molecular exchange between extracellular, intracellular and intercellular networks. Intercellular communication is largely mediated by gap junctions (GJs), a type of specialized membrane contact composed of variable number of channels that enable direct communication between cells by allowing small molecules to pass directly into the cytoplasm of neighbouring cells. Although considerable evidence indicates that gap junctions contribute to the functions of many organs, such as the bone, intestine, kidney, heart, brain and nerve, less is known about their role in oral development and disease. In this review, the current progress in understanding the background of connexins and the functions of gap junctions in oral development and diseases is discussed. The homoeostasis of tooth and periodontal tissues, normal tooth and maxillofacial development, saliva secretion and the integrity of the oral mucosa depend on the proper function of gap junctions. Knowledge of this pattern of cell-cell communication is required for a better understanding of oral diseases. With the ever-increasing understanding of connexins in oral diseases, therapeutic strategies could be developed to target these membrane channels in various oral diseases and maxillofacial dysplasia.

Independent Generation and Reactivity of 2'-Deoxyguanosin-N1-yl Radical

2'-Deoxyguanosin-N1-yl radical (dG(N₁-H)^•) is the thermodynamically favored one-electron oxidation product of 2'-deoxyguanosine (dG), the most readily oxidized native nucleoside. dG(N₁-H)^• is produced by the formal dehydration of a hydroxyl radical adduct of dG as well as by deprotonation of the corresponding radical cation. dG(N₁-H)^• were formed as a result of the indirect and direct effects of ionizing radiation, among other DNA damaging agents. dG(N₁-H)^• was generated photochemically (λ_max = 350 nm) from an N-aryloxy-naphthalimide precursor (3). The quantum yield for photochemical conversion of 3 is ∼0.03 and decreases significantly in the presence O₂, suggesting that bond scission occurs from a triplet excited state. dG is formed quantitatively in the presence of excess β-mercaptoethanol. In the absence of a reducing agent, dG(N₁-H)^• oxidizes 3, decreasing the dG yield to ∼50%. Addition of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) as a sacrificial reductant results in a quantitative yield of dG and two-electron oxidation products of 8-oxodGuo. N-Aryloxy-naphthalimide 3 is an efficient and high-yielding photochemical precursor of dG(N₁-H)^• that will facilitate mechanistic studies on the reactivity of this important reactive intermediate involved in DNA damage.