BACKGROUND:Primary cortical neurons and microglial cells play a crucial role in exploring cell therapies for neurological disorders,and most of the current methods for obtaining the two types of cells are cumbersome and require separate extraction.It is therefore crucial to find a convenient and rapid method to extract both types of cells simultaneously. OBJECTIVE:To explore a novel method for simultaneous extraction of primary cortical neurons and microglial cells. METHODS:Newborn suckling SD rats were taken within 24 hours.The brain was removed and placed in a dish with DMEM,and the pia mater was removed for later use.Primary neurons were extracted from the same brain tissue,and then the remaining brain tissue was used to extract microglial cells.The whole process was performed on ice.Extraction and culture steps of primary cortical neurons:The cerebral cortex was taken 2.0-3.0 mm with forceps,and the tissue was digested with papain for 20 minutes.After aborting digestion,the blown tissue presented an adherent tissue suspension.The supernatant cell suspension was obtained,filtered,and dispensed into 15 mL centrifuge tubes.After centrifugation and re-suspension,the cells were inoculated onto 6-well plate crawls coated with L-polylysine.Neuronal morphology was observed at 1-day intervals,and staining could be performed for identification using immunofluorescence staining of MAP2 and β-Tubulin by day 7.Microglia extraction and culture steps:The remaining brain tissue at 8-10 mm thick was subjected to microglial cell extraction,digested by trypsin for 20 minutes.After digestion was stopped,the tissue was blown to a homogenate,and then the homogenate was transferred to the culture bottle for culture.On day 14,the culture flasks were sealed and subjected to constant temperature horizontal shaking for 2 hours.Microglial cells were shed in the supernatant.Purified microglial cells were taken and continued to be cultured for 3 days for identification by Iba1 immunofluorescence staining. RESULTS AND CONCLUSION:(1)After 24 hours of culture,the neurons were adherent to the wall,the cytosol was enlarged,and some neurons developed synapses.After 3 and 5 days of culture,the cytosol was further enlarged,and most of the neurons were in the form of synapses,and some neurons were growing in clusters.On day 7,neuronal synapses were prolonged and thickened,and they were connected with each other to form a network.The neurons were identified by β-Tubulin and MAP2 immunofluorescence staining.(2)The cells grew close to the wall on day 1 of culture.On days 3,5,and 7,the density of microglial cells was small,and the cell morphology was bright oval or round,but the cells basically grew in clumps on the upper layer of other cells.On day 10,the density of microglial cells increased significantly.On day 14,microglial cells grew in dense clumps on the upper layer of other cells,and then they could be isolated and purified.The isolated and purified cells were taken and re-cultured to day 3 and identified as microglial cells by Iba1 immunofluorescence;their purity was greater than 95%.(3)The results show that primary cortical neurons and microglial cells obtained by this method after extraction and culture are of high purity,good morphology,and high viability.

BACKGROUND:Studies have found that activation of nuclear factor-erythroid 2-related factor 2/heme oxidase-1(Nrf2/HO-1)pathway can alleviate oxidative stress caused by cerebral ischemia-reperfusion injury,but whether human bone marrow mesenchymal stem cells(hBMSC)can activate Nrf2/HO-1 pathway to alleviate cerebral ischemia-reperfusion injury is still lacking relevant studies. OBJECTIVE:To investigate whether intracranial transplantation of hBMSC alleviates oxidative stress injury in cerebral ischemia-reperfusion animal models by activating Nrf2/HO-1 pathway. METHODS:Totally 40 male SPF SD rats were randomly divided into sham operation group,model group,hBMSC transplantation group,hBMSC+solvent group and hBMSC+Nrf2 inhibitor group.Each group consisted of eight animals.In the model group and the hBMSC transplantation group,middle cerebral artery occlusion model was prepared by thread embolization method.The thread embolization was removed 1 hour later,and 30 μL PBS or hBMSC cultured to at least passage 5 was injected into the right cortex and striatum of rats.In the hBMSC+Nrf2 inhibitor group and hBMSC+solvent group,the left ventricle was injected with Nrf2 inhibitor Brusatol and its solvent dimethyl sulfoxide respectively 24 hours before model establishment,then the middle cerebral artery occlusion model was prepared,and hBMSC was injected.Relevant indexes were detected 3 days after transplantation. RESULTS AND CONCLUSION:(1)CT and TTC staining showed the same area and volume of cerebral infarction:model group>hBMSC+Nrf2 inhibitor group>hBMSC+solvent group>hBMSC transplantation group>sham operation group.(2)Hematoxylin-eosin staining and Nissl's staining showed that the ischemic brain tissue was intact and the neurons were normal in the sham operation group.Compared with the model group,the pathological morphology and neuronal injury of the hBMSC transplantation group and the hBMSC+solvent group were significantly improved.Compared with the hBMSC+solvent group,the hBMSC+Nrf2 inhibitor group had more serious pathological morphology and neuronal damage.(3)Western blot assay and oxidative stress index detection results showed that compared with the sham operation group,Nrf2 and HO-1 proteins were decreased(all P<0.05),malondialdehyde was increased and superoxide dismutase was decreased(all P<0.05)in the model group.Compared with the model group,the expression levels of Nrf2 and HO-1 proteins were increased(all P<0.05),malondialdehyde was decreased and superoxide dismutase was increased(all P<0.05)in the hBMSC transplantation group and the hBMSC+solvent group.Compared with the hBMSC+solvent group,the expression levels of Nrf2 and HO-1 proteins were simultaneously decreased(all P<0.05),and malondialdehyde was increased and superoxide dismutase was decreased(all P<0.05)in the hBMSC+Nrf2 inhibitor group.(4)These results indicate that hBMSC can alleviate cerebral ischemia-reperfusion injury possibly by activating Nrf2/HO-1 pathway.

Objective:To investigate the prognosis of patients with initially resectable gastric cancer liver metastasis (GCLM) who were treated by different modalities, and analyze the influencing factors for prognosis of patients.Methods:The retrospective cohort study was conducted. The clinicopathological data of 327 patients with initially resectable GCLM who were included in the database of a nationwide multicenter retrospective cohort study on GCLM based on real-world data from January 2010 to December 2019 were collected. There were 267 males and 60 females, aged 61(54,68)years. According to the specific situations of patients, treatment modalities included radical surgery combined with systemic treatment, palliative surgery combined with systemic treatment, and systemic treatment alone. Observation indicators: (1) clinical characteristics of patients who were treated by different modalities; (2) prognostic outcomes of patients who were treated by different modalities; (3) analysis of influencing factors for prognosis of patients with initially resectable GCLM; (4) screening of potential beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the rank sum test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. The Kaplan-Meier method was used to calculate survival rate and draw survival curve, and Log-Rank test was used for survival analysis. Univariate and multivariate analyses were conducted using the COX proportional hazard regression model. The propensity score matching was employed by the 1:1 nearest neighbor matching method with a caliper value of 0.1. The forest plots were utilized to evaluate potential benefits of diverse surgical combined with systemic treatments within the population. Results:(1) Clinical characteristics of patients who were treated by different modalities. Of 327 patients, there were 118 cases undergoing radical surgery plus systemic treatment, 164 cases undergoing palliative surgery plus systemic treatment, and 45 cases undergoing systemic treatment alone. There were significant differences in smoking, drinking, site of primary gastric tumor, diameter of primary gastric tumor, site of liver metastasis, and metastatic interval among the three groups of patients ( P<0.05). (2) Prognostic outcomes of patients who were treated by different modalities. The median overall survival time of the 327 pati-ents was 19.9 months (95% confidence interval as 14.9-24.9 months), with 1-, 3-year overall survival rate of 61.3%, 32.7%, respectively. The 1-year overall survival rates of patients undergoing radical surgery plus systemic treatment, palliative surgery plus systemic treatment and systemic treatment alone were 68.3%, 63.1%, 30.6%, and the 3-year overall survival rates were 41.1%, 29.9%, 11.9%, showing a significant difference in overall survival rate among the three groups of patients ( χ2=19.46, P<0.05). Results of further analysis showed that there was a significant difference in overall survival rate between patients undergoing radical surgery plus systemic treatment and patients undergoing systemic treatment alone ( hazard ratio=0.40, 95% confidence interval as 0.26-0.61, P<0.05), between patients undergoing palliative surgery plus systemic treatment and patients under-going systemic treatment alone ( hazard ratio=0.47, 95% confidence interval as 0.32-0.71, P<0.05). (3) Analysis of influencing factors for prognosis of patients with initially resectable GCLM. Results of multivariate analysis showed that the larger primary gastric tumor, poorly differentiated tumor, larger liver metastasis, multiple hepatic metastases were independent risk factors for prognosis of patients with initially resectable GCLM ( hazard ratio=1.20, 1.70, 1.20, 2.06, 95% confidence interval as 1.14-1.27, 1.25-2.31, 1.04-1.42, 1.45-2.92, P<0.05) and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy were independent protective factors for prognosis of patients with initially resectable GCLM ( hazard ratio=0.60, 0.39, 0.46, 95% confidence interval as 0.42-0.87, 0.25-0.60, 0.30-0.70, P<0.05). (4) Screening of potentinal beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Results of forest plots analysis showed that for patients with high-moderate differentiated GCLM and patients with liver metastasis located in the left liver, the overall survival rate of patients undergoing radical surgery plus systemic treatment was better than patients undergoing palliative surgery plus systemic treatment ( hazard ratio=0.21, 0.42, 95% confidence interval as 0.09-0.48, 0.23-0.78, P<0.05). Conclusions:Compared to systemic therapy alone, both radical and palliative surgery plus systemic therapy can improve the pro-gnosis of patients with initially resectable GCLM. The larger primary gastric tumor, poorly differen-tiated tumor, larger liver metastasis, multiple hepatic metastases are independent risk factors for prognosis of patients with initial resectable GCLM and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy are independent protective factors for prognosis of patients with initially resectable GCLM.

Objective:To clarify the potential correlation between biological changes of meninges in periodontitis mice and cognitive impairment by analyzing the biological changes of meninges in periodontitis mice using single-cell RNA sequencing.Methods:Thirty C57BL/6 mice were divided into two groups by using random number table method (15 mice in each group). Mice in the control group were locally administered 2% carboxyl methyl cellulose (CMC) without Porphyromonas gingivalis (Pg) on both buccal sides. A mixture of Pg W83 and 2% CMC was applied on both buccal sides in the experimental group mice three times a week, lasting for 16 weeks in total. The absorption of alveolar bone, locomotor activity and cognitive function, the activation of microglia and astrocytes in the cortex were observed and assessed. The mRNA expression levels of Occludin in meninges and brain were detected in two groups. Single-cell RNA sequencing data of meninges were processed by uniform manifold approximation and projection (UMAP). Differential genes expressions of endothelial cells were processed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. In addition, real-time fluorescence quantitative PCR (RT-qPCR) was used to verify the expressions of transcription activating factor 3 (Atf3) and apolpoprotein L domain-containing 1 (Apold 1). Results:Methylene blue staining found the distances of buccal and palatal cement-enamel junction-alveolar bone crest in experimental mice [(185.60±17.60), (206.90±13.37) μm] increased significantly compared with the control group [(135.33±9.57), (163.05±14.98) μm] ( t=5.02, P=0.002; t=4.37, P=0.005). Open field experiment showed the total distance and average speed of mice in the experimental group [(971.88±164.57) cm, (3.25±0.55) cm/s] were not statistically significant compared with the control group [(914.24±278.81) cm, (3.05±0.93) cm/s] ( t=0.65, P=0.525; t=0.65, P=0.520). The recognition index of the experimental group [(48.02±16.92) %] was lower than the control group [(66.27±17.90) %] ( t=2.40, P=0.027) by novel object recognition tests. Compared with the control group [(63.56±11.88) %], the alternation of experimental group [(50.99±14.17) %] was significantly decreased in Y maze tests ( t=2.33, P=0.030). Immunohistochemistry results showed microglia and astrocytes were activated in the cortex of experimental mice. Compared with the control group (1.02±0.25, 1.04±0.31), the relative mRNA expressions of Occludin decreased significantly in the meninges and brain of periodontitis mice, respectively (0.61±0.10, 0.64±0.20) ( t=3.47, P=0.010; t=2.66, P=0.024). By single-cell RNA sequencing, meninges cells were divided into 11 types, such as endothelial cells, fibroblasts, immune cells and so on. Endothelial cells were the main cell types in meninges [the control group: 26.47% (1 589/6 004), the experimental group: 26.26% (807/3 073)]. Compared with the control group [5.56% (334/6 004)], the percentage of granulocytes increased in the periodontitis mice [11.65% (358/3 073)]. Using clustering analysis to further focus on endothelial cells, GO enrichment analysis revealed differential genes were mainly related to angiogenesis, cell adhesion, apoptosis and so on. KEGG enrichment analysis revealed that differential genes were related to signaling pathways of interleukin-17, relaxin and so on. The relative mRNA expressions of Atf3 and Apold1 in meninges of periodontitis mice (0.42±0.24, 0.54±0.27) were significantly lower than the control group (1.03±0.26, 1.02±0.23) ( t=3.88, P=0.005; t=3.02, P=0.017). Conclusions:The mice chronically infected with Pg W83 occurred memory impairment, neuroinflammation and changes of barrier function. In the meninges of periodontitis mice, there were infiltration of immune cells and down-regulation expressions of Atf3 and Apold1 by single-cell RNA sequencing. Meningeal immunity and changes of barrier function may play an important role in the cognitive impairment caused by periodontitis.

Objective This study aimed to compare the current Essen rabies post-exposure immunization schedule(0-3-7-14-28)in China and the simple 4-dose schedule(0-3-7-14)newly recommended by the World Health Organization in terms of their safety,efficacy,and protection. Methods Mice were vaccinated according to different immunization schedules,and blood was collected for detection of rabies virus neutralizing antibodies(RVNAs)on days 14,21,28,35,and 120 after the first immunization.Additionally,different groups of mice were injected with lethal doses of the CVS-11 virus on day 0,subjected to different rabies immunization schedules,and assessed for morbidity and death status.In a clinical trial,185 rabies-exposed individuals were selected for post-exposure vaccination according to the Essen schedule,and blood was collected for RVNAs detection on days 28 and 42 after the first immunization. Results A statistically significant difference in RVNAs between mice in the Essen and 0-3-7-14 schedule groups was observed on the 35th day(P<0.05).The groups 0-3-7-14,0-3-7-21,and 0-3-7-28 showed no statistically significant difference(P>0.05)in RVNAs levels at any time point.The post-exposure immune protective test showed that the survival rate of mice in the control group was 20%,whereas that in the immunization groups was 40%.In the clinical trial,the RVNAs positive conversion rates on days 28(14 days after 4 doses)and 42(14 days after 5 doses)were both 100%,and no significant difference in RVNAs levels was observed(P>0.05). Conclusion The simple 4-dose schedule can produce sufficient RVNAs levels,with no significant effect of a delayed fourth vaccine dose(14-28 d)on the immunization potential.

Objective To investigate the prevalence of Echinococcus infections in small rodents around human residential areas in Yushu City, Qinghai Province in 2023, so as to provide insights into precision echinococcosis control. Methods One or two quadrats, each measuring 50 m × 50 m, were randomly assigned in Shanglaxiu Township and Longbao Township, Yushu City, Qinghai Province on June 2023, respectively, and 300 plate-type mouse traps, each measuring 12.0 cm × 6.5 cm, were assigned in each quadrat. Small rodents were captured during the period between 10 : 00 and 18 : 00 each day for 4 days. Then, all captured small rodents were identified and dissected, and liver specimens with suspected Echinococcus infections were subjected to pathological examinations. The Echinococcus cytochrome c oxidase 1 (cox1) gene was amplified using PCR assay, and the sequence of the amplified product was aligned to that was recorded in the GenBank to characterize the parasite species. In addition, a phylogenetic tree of Echinococcus was generated based on the cox1 gene sequence using the neighbor-joining method. Results A total of 236 small rodents were captured in Shanglaxiu and Longbao townships, Yushu City, including 65 Qinghai voles and 51 plateau pikas in Shanglaxiu Township, and 62 Qinghai voles and 58 plateau pikas in Longbao Township, and there was no significant difference in the constituent ratio of small rodents between the two townships (χ² = 0.294, P > 0.05). Seven plateau pikas and 12 Qinghai voles were suspected to be infected with Echinococcus by dissection, and pathological examinations showed unclear structure of hepatic lobules and disordered hepatocyte arrangement in livers of small rodents suspected of Echinococcus infections. PCR assay identified E. shiquicus DNA in 7 Qinghai voles, which were all captured from Shanglaxiu Township. Phylogenetic analysis showed that the cox1 gene sequence of Echinococcus in small rodents was highly homologous to the E. shiquicus cox1 gene sequence reported previously. Conclusion Plateau pika and Qinghai vole were predominant small rodents around human residential areas in Yushu City, Qinghai Province in 2023, and E. shiquicus infection was detected in Qinghai voles.

Objective To explore the role of secreted frizzled-related protein 3 (sFRP3), a regulator of the Wnt signaling pathway, in the activation and proliferation of murine cardiac fibroblasts (CFs).Methods Neonatal mice aged 1-3 days were obtained for surgical procedures to collect heart tissues.After digestion, CFs were isola-ted and cultured.Transforming growth factor-beta 1 (TGF-β1) stimulation was used to induce activation and prolif-eration in CFs after they adhered to the culture dish.Once the model was confirmed, experimental and control groups were transfected with sFRP3 overexpression plasmids and empty plasmids for 24-48 hours.Expression lev-els of sFRP3, Periostin (POSTN), Type Ⅰ collagen (Collagen Ⅰ), and proliferating cell nuclear antigen (PC-NA) were assessed at the molecular level using Western blot and qRT-PCR.Changes in cell proliferation capacity were examined using MTT, CCK-8, and EdU staining methods.Results In the TGF-β1-induced activation and proliferation model of CFs, compared to the control group, the model group exhibited decreased expression of sFRP3 protein and mRNA, while the expression of activation and proliferation-related proteins PCNA, POSTN, and Collagen Ⅰ was upregulated.Furthermore, in CFs overexpressing sFRP3 through plasmid transfection, the protein and mRNA expression of PCNA, POSTN, and Collagen Ⅰ decreased compared to the empty vector group.MTT, CCK-8 , and EdU experiments indicated a significant decrease in the proliferative activity of CFs in the sFRP3 over-expression group compared to the empty vector group.Conclusion Overexpression of sFRP3 markedly inhibits the activation and proliferation of CFs, suggesting that sFRP3 may be a key gene involved in the regulation of CF acti-vation and proliferation.

Objective:To examine the impact of varied surgical treatment strategies on the prognosis of patients with initial resectable gastric cancer liver metastases (IR-GCLM).Methods:This is a retrospective cohort study. Employing a retrospective cohort design, the study selected clinicopathological data from the national multi-center retrospective cohort study database, focusing on 282 patients with IR-GCLM who underwent surgical intervention between January 2010 and December 2019. There were 231 males and 51 males, aging ( M(IQR)) 61 (14) years (range: 27 to 80 years). These patients were stratified into radical and palliative treatment groups based on treatment decisions. Survival curves were generated using the Kaplan-Meier method and distinctions in survival rates were assessed using the Log-rank test. The Cox risk regression model evaluated HR for various factors, controlling for confounders through multivariate analysis to comprehensively evaluate the influence of surgery on the prognosis of IR-GCLM patients. A restricted cubic spline Cox proportional hazard model assessed and delineated intricate associations between measured variables and prognosis. At the same time, the X-tile served as an auxiliary tool to identify critical thresholds in the survival analysis for IR-GCLM patients. Subgroup analysis was then conducted to identify potential beneficiary populations in different surgical treatments. Results:(1) The radical group comprised 118 patients, all undergoing R0 resection or local physical therapy of primary and metastatic lesions. The palliative group comprised 164 patients, with 52 cases undergoing palliative resections for gastric primary tumors and liver metastases, 56 cases undergoing radical resections for gastric primary tumors only, 45 cases undergoing palliative resections for gastric primary tumors, and 11 cases receiving palliative treatments for liver metastases. A statistically significant distinction was observed between the groups regarding the site and the number of liver metastases (both P<0.05). (2) The median overall survival (OS) of the 282 patients was 22.7 months (95% CI: 17.8 to 27.6 months), with 1-year and 3-year OS rates were 65.4% and 35.6%, respectively. The 1-year OS rates for patients in the radical surgical group and palliative surgical group were 68.3% and 63.1%, while the corresponding 3-year OS rates were 42.2% and 29.9%, respectively. A comparison of OS between the two groups showed no statistically significant difference ( P=0.254). Further analysis indicated that patients undergoing palliative gastric cancer resection alone had a significantly worse prognosis compared to other surgical options ( HR=1.98, 95% CI: 1.21 to 3.24, P=0.006). (3) The size of the primary gastric tumor significantly influenced the patients′ prognosis ( HR=2.01, 95% CI: 1.45 to 2.79, P<0.01), with HR showing a progressively increasing trend as tumor size increased. (4) Subgroup analysis indicates that radical treatment may be more effective compared to palliative treatment in the following specific cases: well/moderately differentiated tumors ( HR=2.84, 95% CI 1.49 to 5.41, P=0.001), and patients with liver metastases located in the left lobe of the liver ( HR=2.06, 95% CI 1.19 to 3.57, P=0.010). Conclusions:In patients with IR-GCLM, radical surgery did not produce a significant improvement in the overall prognosis compared to palliative surgery. However, within specific patient subgroups (well/moderately differentiated tumors, and patients with liver metastases located in the left lobe of the liver), radical treatment can significantly improve prognosis compared to palliative approaches.

Objective:To compare the results of invasive prenatal diagnosis and preimplantation genetic testing (PGT) and explore the underlying mechanism.Methods:Clinical data of pregnant women undergoing PGT and invasive prenatal diagnosis at the Sixth Affiliated Hospital of Sun Yat-sen University from January 2019 to December 2022 were collected. The results of PGT and invasive prenatal diagnosis were compared, and the outcomes of pregnancies were followed up. This study has been approved by the Medical Ethics Committee of the the Sixth Affiliated Hospital of Sun Yat-sen University (No. 2022SLYEC-491).Results:A total of 172 couples were included in this study, and 26 non-targeted variants were discovered upon prenatal diagnosis, including 10 cases (38.5%) by chromosomal karyotyping, 15 (57.7%) by chromosomal microarray analysis (CMA), and 1 (3.8%) by whole exome sequencing. The 10 karyotypic anomalies had included 6 chromosomal polymorphisms, 2 chromosomal mosaicisms, 1 paternally derived translocation, and 1 missed maternal chromosomal inversion. CMA has identified 15 copy number variations (CNVs), which included 11 microdeletions and microduplications, 3 loss of heterozygosity, and 1 low-level mosaicism of paternal uniparental disomy. One CNV was classified as pathogenic, and another one was likely pathogenic, whilst the remaining 13 were classified as variants of uncertain significance. Therefore, 8.7% of CNVs was detected by invasive prenatal diagnosis after PGT. 92.3% (24/26) of the non-targeted variants have been due to technological limitations of next-generation sequencing (NGS).Conclusion:Invasive prenatal diagnosis after PGT can detect non-targeted variants, which may further reduce the incidence of birth defects.

Optogenetics combines optics and genetic engineering to control specific gene expression and biological functions and has the advantages of precise spatiotemporal control,noninvasiveness,and high efficiency.Genetically modified photosensory sensors are engineered into proteins to modulate conformational changes with light stimulation.Therefore,optogenetic techniques can provide new insights into oral biological processes at different levels,ranging from the subcellular and cellular levels to neural circuits and behavioral models.Here,we introduce the origins of optogenetics and highlight the recent progress of optogenetic approaches in oral and craniofacial research,focusing on the ability to apply optogenetics to the study of basic scientific neural mechanisms and to establish different oral behavioral test models in vivo(orofacial movement,licking,eating,and drinking),such as channelrhodopsin(ChR),archaerhodopsin(Arch),and halorhodopsin from Natronomonas pharaonis(NpHR).We also review the synergic and antagonistic effects of optogenetics in preclinical studies of trigeminal neuralgia and maxillofacial cellulitis.In addition,optogenetic tools have been used to control the neurogenic differentiation of dental pulp stem cells in translational studies.Although the scope of optogenetic tools is increasing,there are limited large animal experiments and clinical studies in dental research.Potential future directions include exploring therapeutic strategies for addressing loss of taste in patients with coronavirus disease 2019(COVID-19),studying oral bacterial biofilms,enhancing craniomaxillofacial and periodontal tissue regeneration,and elucidating the possible pathogenesis of dry sockets,xerostomia,and burning mouth syndrome.