Periodontal bone defects, primarily caused by periodontitis, are highly prevalent in clinical settings and manifest as bone fenestration, dehiscence, or attachment loss, presenting a significant challenge to oral health. In regenerative medicine, harnessing developmental principles for tissue repair offers promising therapeutic potential. Of particular interest is the condensation of progenitor cells, an essential event in organogenesis that has inspired clinically effective cell aggregation approaches in dental regeneration. However, the precise cellular coordination mechanisms during condensation and regeneration remain elusive. Here, taking the tooth as a model organ, we employed single-cell RNA sequencing to dissect the cellular composition and heterogeneity of human dental follicle and dental papilla, revealing a distinct Platelet-derived growth factor receptor alpha (PDGFRA) mesenchymal stem/stromal cell (MSC) population with remarkable odontogenic potential. Interestingly, a reciprocal paracrine interaction between PDGFRA⁺ dental follicle stem cells (DFSCs) and CD31⁺ Endomucin⁺ endothelial cells (ECs) was mediated by Vascular endothelial growth factor A (VEGFA) and Platelet-derived growth factor subunit BB (PDGFBB). This crosstalk not only maintains the functionality of PDGFRA⁺ DFSCs but also drives specialized angiogenesis. In vivo periodontal bone regeneration experiments further reveal that communication between PDGFRA⁺ DFSC aggregates and recipient ECs is essential for effective angiogenic-osteogenic coupling and rapid tissue repair. Collectively, our results unravel the importance of MSC-EC crosstalk mediated by the VEGFA and PDGFBB-PDGFRA reciprocal signaling in orchestrating angiogenesis and osteogenesis. These findings not only establish a framework for deciphering and promoting periodontal bone regeneration in potential clinical applications but also offer insights for future therapeutic strategies in dental or broader regenerative medicine.
Receptor, Platelet-Derived Growth Factor alpha/metabolism* ; Humans ; Neovascularization, Physiologic/physiology* ; Dental Sac/cytology* ; Single-Cell Analysis ; Transcriptome ; Mesenchymal Stem Cells/metabolism* ; Bone Regeneration ; Animals ; Dental Papilla/cytology* ; Periodontium/physiology* ; Stem Cells/metabolism* ; Regeneration ; Angiogenesis

Objective:To analyze the immune microenvironment characteristics of human dental follicle tissues from the third molars and to explore the mutual communication and the effects of innate immune cells and adaptive immune cells within the dental follicle.Methods:Sequencing data(GSA-Human:HRA008022)in the GSA database were analyzed.Bioinformatics tools were employed for gene identification and GO enrichment analysis was performed to define the biological function of innate and adaptive immune cells.CellChat analysis was used for explaining intercellular communication among immune cell populations.Results:Using t-SNE dimen-sionality reduction analysis for immune cell populations,innate immune cell populations were obtained,including innate lymphoid cells,dendritic cells,mast cells and macrophages,and adaptive immune cell populations including T cells and B cells.Pearson corre-lation analysis showed that innate immune cells,specifically innate lymphoid cells and macrophages,had a strong correlation with adap-tive immune cell populations.GO enrichment analysis revealed mutual coordination among innate immune cell populations and regulato-ry effects on adaptive immune cell populations.Further CellChat analysis indicated biological signal transmission between innate and a-daptive immune cell populations,with CLEC,MIF,ADGRE5,COLLAGEN and MIF signaling pathways is the most significant.Con-clusion:Dental follicle tissues are rich in immune cells and innate immune cell populations interact with adaptive immune cells to regulate immune responses and participate in maintaining the homeostasis of dental follicle.

Cerebral autoregulation (CA), as one of the intrinsic mechanisms for maintaining cerebral hemodynamic homeostasis, utilizes various regulatory methods to induce vasoconstriction reactions in resistance vessels, mainly small blood vessels, to maintain relatively constant cerebral blood flow perfusion within a certain range of blood pressure fluctuations. It has important value in evaluating the severity and predicting the outcome of acute ischemic stroke. This article reviews the evaluation methods of CA and its application in patients with acute ischemic stroke.

ObjectiveTo investigate the mechanism of Gegen Qinliantang（GQT） on the intestinal flora of antibiotic-associated diarrhea（AAD） by 16S rRNA sequencing and network pharmacology. MethodSixty SD rats were randomly divided into six groups（n=10）， including blank group， model group， GQT high-， medium- and low-dose groups（10.08， 5.04， 2.52 g·kg^-1） as well as Lizhu Changle group（0.15 g·kg^-1）， except for the blank group， each group was given clindamycin（250 mg·kg^-1） by gavage once a day for 7 consecutive days. After successful modeling， the blank group and the model group were given equal volumes of normal saline by gavage. The other groups were given corresponding doses of drugs by gavage for 14 days. Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform（TCMSP） was used to screen the active components and targets of GQT， GeneCards， Online Mendelian Inheritance in Man（OMIM） database， Pharmacogenetics and Pharmacogenomics Knowledge Base（PharmGKB）， DrugBank and DisGeNET were used to search for AAD disease targets. The drug-disease common targets were obtained by R software. STRING was applied to analyze the target protein-protein interaction， and Kyoto Encyclopedia of Genes and Genomes（KEGG） pathway enrichment analysis was performed. Then hematoxylin-eosin（HE） staining was used to observe the pathological changes of the colon， and 16S rRNA sequencing of AAD colon content flora structure further verified the results of network pharmacology. ResultThrough network pharmacology， it was found that 238 active components were screened from GQT and acted on 276 component targets， among which quercetin， puerarin， wogonin and apigenin were the main core components of GQT， 1 097 AAD disease targets and 127 drug-disease intersection targets. The protein-protein interaction network mainly included core targets such as protein kinase B1（Akt1）， interleukin（IL）-6 and IL-1β， which were mainly enriched in the IL-17 signaling pathway. It was verified through animal experiments that compared with the blank group， the colon structure of the model group was seriously abnormal， the intestinal epithelial columnar cells were damaged， the goblet cells were reduced， and a large number of inflammatory cells were infiltrated. Compared with the model group， the colon structure of the GQT high-dose group improved， but there were still abnormalities， the colon structure of GQT medium- and low- dose groups and Lizhu Changle group improved significantly and reached the normal level. GQT could improve the structural diversity of AAD intestinal flora. At the phylum level， the abundance of Firmicutes was increased and the abundance of Bacteroidetes was decreased. At the genus level， the abundance of Lactobacillus was increased， and the abundances of Prevotella and Bacteroides were decreased. Among them， Lactococcus could be used as a biomarker for AAD treatment with GQT， and the prediction of functional metabolism of intestinal flora revealed that GQT could promote acetate and lactate metabolic pathways in the intestine. ConclusionGQT may activate IL-17 signaling pathway by acting on the targets of Akt1 and IL-6 through key components such as quercetin and wogonin， and improve the abundance of Lactococcus in the intestinal tract as well as acetate and lactate metabolic pathways， so as to play a role in repairing the intestinal barrier for the treatment of AAD.