Cerebral organoids are three-dimensional nerve cultures induced by embryonic stem cells(ESCs)or induced pluripotent stem cells(iPSCs)that mimic the structure and function of human brain.With the continuous optimization of cerebral organoid culture technology and the combination with emerging technologies such as organ transplantation,gene editing and organoids-on-chip,complex brain tissue structures such as functional vascular structures and neural circuits have been produced,which provides new methods and ideas for studying human brain development and diseases.This article reviews the latest advances in brain organoid technology,describes its application in neurological diseases and advances in stroke modeling and transplantation treatment.

Post-stroke cognitive impairment(PSCI)is mainly manifested as learning and memory disorders.Highly enriched RNA m6A methylation modification in mammalian brain is involved in glial cell-mediated neuroinflammation.Given that neuroinflammation is the main mechanism for neural damage and spatial and memory impairment of PSCI,it is speculated that RNA m6A methylation modification can regulate the inflammatory response of glial cells after stroke to improve PSCI.This review summarizes and analyzes the role of RNA m6A methylation modification in the development of PSCI and analyzes its detailed mechanism of regulating glial cell-mediated inflammation,which will provide reference for researchers in this field.

BACKGROUND:Long non-coding RNAs(lncRNAs),as important regulators of the inflammatory response,are involved in the immune-inflammation-brain crosstalk mechanism after ischemic stroke and have the potential to become a therapeutic agent for neurological dysfunction after ischemic stroke. OBJECTIVE:To analyze and summarize the molecular mechanism of lncRNA acting on glial cells involved in the neuroimmuno-inflammatory cascade response after ischemic stroke and the associated signaling pathways,pointing out that lncRNAs have the potential to regulate inflammation after ischemic stroke. METHODS:PubMed was searched using the search terms of"ischemic stroke,long non-coding RNA,neuroinflammation,immune function,signal pathway,microglia,astrocytes,oligodendrocyte,mechanism,"and 63 relevant documents were finally included for review. RESULTS AND CONCLUSION:In the early stage of ischemic stroke,the death of nerve cells due to ischemia and hypoxia activates the innate immune response of the brain,promoting the secretion of inflammatory factors and inducing blood-brain barrier damage and a series of inflammatory cascades responses.As an important pathogenesis factor in ischemic stroke,the neuroimmuno-inflammatory cascade has been proved to seriously affect the prognosis of patients with ischemic stroke,and it needs to be suppressed promptly in the early stage.Neuroinflammation after ischemic stroke usually induces abnormal expression of a large number of lncRNAs that mediate a series of neuro-immune-inflammatory crosstalk mechanisms through regulating the polarization of microglia,astrocytes and oligodendrocytes to exert post-stroke neuroprotective effects.LncRNAs,as important regulatory factors of the inflammatory response,inhibit the neuroimmuno-inflammatory cascade response after ischemic stroke through regulating nuclear factor-κB,lncRNA-miRNA-mRNA axis,Rho-ROCK,MAPK,AKT,ERK and other signaling pathways to effectively improve neurological impairment after ischemic stroke.Most of experimental studies on the interaction between lncRNAs and ischemic stroke are based on a middle cerebral artery occlusion model or a cerebral ischemia-reperfusion injury model,but no clinical trials have been conducted.Therefore,it remains to be further explored about whether lncRNAs can be safely applied in clinical practice.At present,there are many therapeutic drugs for the treatment of ischemic stroke,but there are relatively few studies on the application of lncRNAs,exosomes and other transplantation technologies for the treatment of ischemic stroke using tissue engineering technology,which need to be further explored.lncRNA has become an important target for the treatment of ischemic stroke with its relative stability and high specificity.In future studies,more types of inflammatory lncRNAs that function under ischemic-hypoxia conditions should continue to be explored,in order to provide new research directions for the treatment of neuroinflammation after ischemic stroke.

BACKGROUND:Our previous studies found that adding barium sulfate could improve the mechanical and radiopaque properties of calcium phosphate cement.However,with the degradation of calcium phosphate,the remaining radiopaque agent is difficult to degrade,and the space-occupying and osteoclast effects at the implantation site affect the bone repair process.Therefore,it is necessary to develop a new biodegradable radiopaque material. OBJECTIVE:To discuss the radiopaque ability of bioactive degradable material strontium polyphosphate(SrPP)and its impact on the physicochemical properties and osteogenic effect of calcium phosphate cement. METHODS:(1)Calcium phosphate cement(CPC),starch modified calcium phosphate cement(CPS)and starch modified calcium phosphate cement(20%SrPP-CPN)containing SrPP(20%mass fraction of bone cement powder)were prepared respectively,and the physicochemical properties of the three groups of bone cements were characterized.(2)The three groups of bone cement extracts were co-cultured with rat bone marrow mesenchymal stem cells,respectively,to detect cell proliferation,energy metabolism,and osteogenic differentiation.(3)Bone defects with a diameter of 5 mm were made on each side of the top of the skull of 24 SD rats,and they were randomly divided into control group(without any intervention),CPC group,CPS group,and 20%SrPP-CPN group for intervention,with 6 rats in each group.Relevant tests were performed after 4 and 12 weeks of intervention. RESULTS AND CONCLUSION:(1)Compared with the other two groups of bone cement,20%SrPP-CPN had enhanced radiopaque ability,increased compressive strength and degradation rate,and prolonged curing time,and 20%SrPP-CPN could release Sr2+ stably during degradation.(2)CCK-8 assay showed that 20%SrPP-CPN did not affect the proliferation of bone marrow mesenchymal stem cells.Cell starvation test(serum-free culture)showed that 20%SrPP-CPN could promote the proliferation of bone marrow mesenchymal stem cells compared with the other two groups of bone cement.Compared with the other two groups of bone cements,20%SrPP-CPN increased adenosine triphosphate concentration in bone marrow mesenchymal stem cells.Alkaline phosphatase and alizarin red staining showed that 20%SrPP-CPN could promote osteogenic differentiation of bone marrow mesenchymal stem cells compared with the other two groups of bone cement.(3)In the rat skull defect experiment,Micro-CT scanning and histological observation(hematoxylin-eosin and Masson stainings)showed that bone cement in 20%SrPP-CPN group was significantly degraded compared with that in CPC and CPS groups,and a large number of new bone tissues were dispersed in degraded bone cement.Immunohistochemical staining showed that Runx2 protein expression was increased in 20%SrPP-CPN group compared with CPC group and CPS group(P＜0.01).(4)These results show that 20%SrPP-CPN has good radiopaque ability and osteogenic properties.

Background Chronic excessive exposure to fluoride can cause damage to the central nervous system and a certain degree of learning and memory impairment. However, the associated mechanism is not yet clear and further exploration is needed. Objective Using 4D unlabelled quantitative proteomics techniques to explore differentially expressed proteins and their potential mechanisms of action in chronic excessive fluoride exposure induced brain injury. Methods Twenty-four SPF-grade adult SD rats, half male and half male, were selected and divided into a control group and a fluoride group by random number table method, with 12 rats in each group. Among them, the control group drank tap water (fluorine content<1 mg·L⁻¹), the fluoride group drank sodium fluoride solution (fluorine content 10 mg·L⁻¹), and both groups were fed with ordinary mouse feed (fluoride content<0.6 mg·kg⁻¹). After 180 d of feeding, the SD rats were weighed, and then part of the brain tissue was sampled for pathological examination by hematoxylin-eosin (HE) staining and Nissl staining. The rest of the brain tissue was frozen and stored at −80 ℃. Three brain tissue samples from each group were randomly selected for proteomics detection. Differentially expressed proteins were screened and subcellular localization analysis was performed, followed by Gene Ontology (GO) function analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, cluster analysis, and protein-protein interaction analysis. Finally, Western blotting was used to detect the expression levels of key proteins extracted from the brain tissue samples. Results After 180 d of feeding, the average weight of the rats in the fluoride group was significantly lower than that in the control group (P<0.05). The brain tissue stained with HE showed no significant morphological changes in the cerebral cortex of the fluoride treated rats, and neuron loss, irregular arrangement of neurons, eosinophilic changes, and cell body pyknosis were observed in the hippocampus. The Nissl staining results showed that the staining of neurons in the cerebral cortex and hippocampus of rats exposed to fluoride decreased (Nissl bodies decreased). The proteomics results showed that a total of 6927 proteins were identified. After screening, 206 differentially expressed proteins were obtained between the control group and the fluoride group, including 96 up-regulated proteins and 110 down-regulated proteins. The differential proteins were mainly located in cytoplasm (30.6%), nucleus (27.2%), mitochondria (13.6%), plasma membrane (13.6%), and extracellular domain (11.7%). The GO analysis results showed that differentially expressed proteins mainly participated in biological processes such as iron ion transport, regulation of dopamine neuron differentiation, and negative regulation of respiratory burst in inflammatory response, exercised molecular functions such as ferrous binding, iron oxidase activity, and cytokine activity, and were located in the smooth endoplasmic reticulum membrane, fixed components of the membrane, chloride channel complexes, and other cellular components. The KEGG significantly enriched pathways included biosynthesis of secondary metabolites, carbon metabolism, and microbial metabolism in diverse environments. The results of differential protein-protein interaction analysis showed that the highest connectivity was found in glucose-6-phosphate isomerase (Gpi). The expression level of Gpi in the brain tissue of the rats in the fluoride group was lower than that in the control group by Western blotting (P<0.05). Conclusion Multiple differentially expressed proteins are present in the brain tissue of rats with chronic fluorosis, and their functions are related to biosynthesis of secondary metabolites, carbon metabolism, and microbial metabolism in diverse environments; Gpi may be involved in cerebral neurological damage caused by chronic overdose fluoride exposure.

Objective To explore the genetic polymorphism and mutation rate of 36 Y-STR loci in Sichuan Han population and provide basic data for their forensic applications.Methods Blood samples were collected from 307 unrelated male individuals and 367 father-son pairs in Sichuan Han population using FTA blood sampling cards.The Y41SE-v1.2 kit was used to type 36 Y-STR loci,and the population genetic parameters and mutation rates of each locus were calculated.The genetic relationship between Sichuan Han population and other ethnic populations was analyzed in combination with 19 other populations in China.Results A total of 79 mutations were observed in 36 Y-STR loci in 367 father-son pairs of Sichuan Han population,with an average mutation rate of 6.00×10-3.There were 74(93.67%)one-step mutations and 5(6.33%)multi-step mutations.A total of 383 alleles were found at 36 Y-STR loci in 307 Sichuan Han males.The number of alleles at each locus ranged from 5(0.016 29)to 56(0.182 41),GD ranged from 0.100 02(DYS645)to 0.959 99(DYS385),and 306 haplotypes were found.The HD,DC and HMP values were 0.999 973,99.67%and 0.003 284,respectively.The results of genetic distance(Fst)analysis showed that the Sichuan Han population had the closest genetic distance with the Chongqing Han population(0.000 9)and the furthest genetic distance with the Xinjiang Mongolian group(0.032 0).The MDS based on genetic distance was basically consistent with the results of cluster analysis.Conclusion The 36 Y-STR loci have high genetic polymorphism in the Sichuan Han population.The study data can provide data support for the construction of the Y-STR database in this region,and also provide basic genetic information for forensic investigation and population genetics research.

Objective:To explore characteristics of intestinal flora in patients with rheumatoid arthritis complicated with inter-stitial lung disease(RA-ILD),to analyze its influencing factors,and to explore improvement of intestinal flora in patients with RA-ILD by different treatment methods.Methods:A total of 100 patients with RA-ILD who visited Shijiazhuang People's Hospital from June 2021 to June 2022 were selected as research objects,and 100 healthy patients in Shijiazhuang People's Hospital during same pe-riod were selected as healthy group.High throughput sequencing was performed on intestinal flora of two groups,OTU flora abundance and α-Diversity,β-diversity,flora distribution and LEfSe difference were analyzed.Another 100 patients with RA-ILD were randomly divided into group A(n=50)and group B(n=50).Group A was treated with leflunomide+nidanib or pifenidone,and group B was treated with leflunomide+nidanib or pifenidone+bifidobacterium triad.Improvement of intestinal flora in two groups after treatment was analyzed.Correlation analysis was used to determine correlation between changes of intestinal flora and clinical characteristics and indicators in RA-ILD patients.Results:OTU flora abundance,α-diversity and β-diversity in RA-ILD patients were lower than that of healthy people.Abundance of Intestinibacter in RA-ILD group was higher than that in healthy group,and abundance of Lactobacillus,Escherichia coli,Klebsiella,Candidatus saccharimonas,Odoribacter and Enterococcus in RA-ILD group were lower than that in healthy group.After treatment,flora structure of group A and group B was improved.Group B was closer to healthy population,and cu-rative effect was significantly better than that of group A.Integinibacter bacteria level was positively correlated with age,RA course,DAS28,CRP,RF and KL-6(P<0.05),and negatively correlated with DLCO(P<0.05).Lactobacillus level was negatively correlated with course of RA,DAS28,CRP,RF,IL-6(P<0.05),and positively correlated with VC(P<0.05);Shigella coli level was negtively correlatied with RA course,ILD course,DAS28,ESR,RF,TNF-α(P<0.05).Klebsiella level was positively correlated with VC and DLCO(P<0.05);Bacterial level of Candida saccharimonas was negatively correlated with DAS28,ESR,CRP,RF,IL-6,TNF-α(P<0.05)and positive correlated with DLCO(P<0.05);Odoribacter bacteria level was negatively correlated with DAS28,CRP,RF,IL-6 and KL-6(P<0.05),and positively correlated with VC(P<0.05);Enterococcus level was negatively correlated with course of RA,ILD,DAS28,ESR,RF and KL-6(P<0.05),while positively correlated with DLCO(P<0.05).Conclusion:Intestinal microflora abundance of RA-ILD patients is significantly lower than that of healthy people,and there aree significant differences in some microflora,which are closely related to clinical characteristics and indicators.Using of bifidobacterium triad in clinical treatment is helpful to improve intestinal flora of RA-ILD patients.

Post-stroke cognitive impairment(PSCI)is a common complication after stroke,which significantly affects quality of life.However,the pathogenesis has not been fully explained.Increasing evidence has shown that the mechanism of programmed cell death(PCD)is related to PSCI,including apoptosis,necroptosis,pyroptosis,PANoptosis,parthanatos,and ferroptosis.Therefore,it is crucial to clearly understand the various mechanisms of PCD and their relationship with PSCI,and to elucidate the role of PCD in PSCI pathogenesis.The article reviews six PCD pathways related to PSCI,summarizes their mechanisms of action in PSCI,and elucidates the possible crosstalk among pathways to provide a basis for clinical targeting of regulatory factors in the PCD pathway for PSCI treatment.

Objective Explore the feasibility and accuracy of using deep learning techniques for gender inference in panoramic dental radiography images of Chinese Han population.Methods A total of 10,600 OPG images from Han individuals aged 18 to 70(5,300 males and 5,300 females)were collected and randomly divided into training set,validation set,and test set in an 8:1:1 ratio.MobileNetV2,Swin Transformer Small,and Swin Transformer Tiny models were trained,and the classification performance of the models was evaluated and visually displayed using accuracy,F1 score,and Grad-CAM algorithm.Results The accuracy of MobileNetV2,Swin Transformer Small,and Swin Transformer Tiny models was 97.57%,95.13%,and 96.28%respectively,with MobileNetV2 model showing the best overall performance.The Grad-CAM algorithm revealed that male OPG images mainly focused on the left and right mandibular branches and alveolar bone,while female OPG images mainly focused on the maxillary sinus,left mandibular branch,and posterior alveolar bone.Conclusion This study demonstrates that the gender inference model based on deep learning techniques for OPG images of Chinese Han population has high accuracy and generalization ability,providing a new approach for forensic gender determination in forensic medicine.

Objective:To investigate the effects of excessive fluoride exposure on astrocytes and the expression of glial fibrillary acidic protein (GFAP), in vitro and in vivo. Methods:(1) In vivo experiment: 24 SPF SD rats, half male and half female, were randomly divided into control and fluoride exposed groups according to sex and body weight, 12 rats in each group. Rats were fed with < 1 mg/L and 50 mg/L sodium fluoride solution prepared by tap water for 6 months, respectively. The expression levels of GFAP protein in rat brain tissue were measured by immunofluorescence, immunohistochemistry and Western blotting. (2) In vitro experiment: adult (6-month-old) rat cortical astrocytes were extracted and cultured in primary culture (4 mmol/L sodium fluoride solution for 24 h), and the astrocytes were identified by immunofluorescence, and GFAP mRNA and protein expression levels were detected by real-time fluorescence quantitative PCR and Western blotting, respectively, and astrocytes apoptosis and calcium ion content were detected by flow cytometry. Results:(1) In vivo experiment: the results of immunofluorescence, immunohistochemistry and Western blotting showed that the GFAP protein expression level in brain tissue of rats exposed to fluoride was higher than that of control group (0.440 ± 0.200 vs 0.250 ± 0.120, t =-5.93, P = 0.027; 0.270 ± 0.020 vs 0.240 ± 0.050, t =-4.87, P = 0.040; 1.017 ± 0.001 vs 0.486 ± 0.006, t =-52.48, P = 0.001). (2) In vitro experiment: GFAP positive cells were identified as astrocytes by immunofluorescence; GFAP mRNA expression level was higher in fluoride exposed group than that of control group by real-time fluorescence quantitative PCR (2.780 ± 0.120 vs 0.134 ± 0.005, t =-37.84, P = 0.001). The Western blotting results showed that the GFAP protein expression level was higher in fluoride exposed group than that of control group (2.76 ± 0.10 vs 1.38 ± 0.05, t =-20.44, P = 0.002). Flow cytometry results showed that the apoptosis rate of astrocytes was higher in fluoride exposed group than that of control group (%: 55.0 ± 1.0 vs 3.5 ± 0.6, t =-10.28, P = 0.009) and the calcium ion content was lower than that of control group (%: 54 ± 9 vs 72 ± 13, t = 4.64, P = 0.043). Conclusion:Excessive fluoride exposure causes increased GFAP expression in astrocytes in vitro and in vivo, promotes apoptosis, and affects calcium signaling pathways.