Dental mesenchymal stem cells(DMSCs)are pivotal for tooth development and periodontal tissue health and play an important role in tissue engineering and regenerative medicine because of their multidirectional differen...Dental mesenchymal stem cells(DMSCs)are pivotal for tooth development and periodontal tissue health and play an important role in tissue engineering and regenerative medicine because of their multidirectional differentiation potential and self-renewal ability.The cellular microenvironment regulates the fate of stem cells and can be modified using various optimization techniques.These methods can influence the cellular microenvironment,activate disparate signaling pathways,and induce different biological effects.“Epigenetic regulation”refers to the process of influencing gene expression and regulating cell fate without altering DNA sequences,such as histone methylation.Histone methylation modifications regulate pivotal transcription factors governing DMSCs differentiation into osteo-/odontogenic lineages.The most important sites of histone methylation in tooth organization were found to be H3K4,H3K9,and H3K27.Histone methylation affects gene expression and regulates stem cell differentiation by maintaining a delicate balance between major trimethylation sites,generating distinct chromatin structures associated with specific downstream transcriptional states.Several crucial signaling pathways associated with osteogenic differentiation are susceptible to modulation via histone methylation modifications.A deeper understanding of the regulatory mechanisms governing histone methylation modifications in osteo-/odontogenic differentiation and immune-inflammatory responses of DMSCs will facilitate further investigation of the epigenetic regulation of histone methylation in DMSC-mediated tissue regeneration and inflammation.Here is a concise overview of the pivotal functions of epigenetic histone methylation at H3K4,H3K9,and H3K27 in the regulation of osteo-/odontogenic differentiation and renewal of DMSCs in both non-inflammatory and inflammatory microenvironments.This review summarizes the current research on these processes in the context of tissue regeneration and therapeutic interventions.展开更多
BACKGROUND： Morphological data have shown that the most important afferent fibers of papillary body come from hippocampal structure.OBJECTIVE： To observe the changes of evoked potential in hippocampus and the signif...BACKGROUND： Morphological data have shown that the most important afferent fibers of papillary body come from hippocampal structure.OBJECTIVE： To observe the changes of evoked potential in hippocampus and the significance after electrostimulation at medial mamillary nucleus. DESIGN： An observational control experiment.SETTING： Department of Physiology, Shenyang Medical College.MATERIALS ： Twenty-three male or female Wistar rats, 3-4 months old, weighing 270-350 g, were provided by bhe animal room of Shenyang Medical College [the license number was scxk（Liao）2003-0016]. METHODS： The Wistar rats were anaesthetized by intraperintoneal injection of 20% urethane （1 g/kg）, tracheal intubation was also given. The self-made double-pole metal stimulating electrode with the point diameter of 1 mm was inserted into medial mamillary nucleus, the wanted hippocampal guidance spot was found within the rang of the hippocampal region at the same side of tee mamillary body range （CA1-CA4）, inserted with same-core guidance electrode, a sole square-wave stimulation of wave wide 0.2 ms stimulated with electrodes at the applied intensity of 7-9 V, the evoked potential was induced through guidance electrodes, and then input to the ATAC-350 data-processing machine for memory showing wave processing, the memory recorded wave recording graph was separately drawn up by the X-Y recording instrument to observe the latency, time procedure and amplitude of the evoked potential in each hippocampal region of the rats and calculate the percentage of the evoked potential in each hippocampal region. Totally 78 guidance spots in hippocampus were recorded, including 30 positive reaction spots and 48 negative ones. MAIN OUTCOME MEASURES： ① Latency, time procedure and amplitude of the evoked potentials in each hippocampal region of rats; ②percentage of the evoked potentials in each hippocampal region; ③ the wave shapes of the evoked potentials in each hippocampal region from different arrangement in the same positive reaction spot. RESULTS ：① Of the 30 recorded positive reactions, 9 positive spots fused into the stimulated false marks because of the short latency. The analysis of variance showed that the latency had significant difference （P 〈 0.05）, time procedure had highly significant difference （P 〈 0.01 ）, but there was no significant difference in the amplitude （P 〉 0.05） among the hippampal regions.② Among the 30 positive spots, the percentage of evoked potential in the hippocampal regions were 34.5% for CA1, 2.0% for CA2, 24.1% for CA3 and 22.4% for CA4. ③ In different levels of the same positive spot, different changes of the evoked potential wave shapes could be observed, and the most obvious change was that of positive wave amplitude. At different positive spots, evoked potentials of positive phase, negative and the double-phase could be observed. CONCLUSION： There are nerve associations between mamillary body and hippocampus, afferent fibers of mamillary body come from hippocampal CA1 region are a little more.展开更多
基金supported by grants from the National Key Research and Development Program(2022YFA1104401)CAMS Innovation Fund for Medical Sciences(2019-I2M-5-031 to Z.P.F.)grants from Innovation Research Team Project of Beijing Stomatological Hospital,Capital Medical University(NO.CXTD202204 to Z.P.F.).
文摘Dental mesenchymal stem cells(DMSCs)are pivotal for tooth development and periodontal tissue health and play an important role in tissue engineering and regenerative medicine because of their multidirectional differentiation potential and self-renewal ability.The cellular microenvironment regulates the fate of stem cells and can be modified using various optimization techniques.These methods can influence the cellular microenvironment,activate disparate signaling pathways,and induce different biological effects.“Epigenetic regulation”refers to the process of influencing gene expression and regulating cell fate without altering DNA sequences,such as histone methylation.Histone methylation modifications regulate pivotal transcription factors governing DMSCs differentiation into osteo-/odontogenic lineages.The most important sites of histone methylation in tooth organization were found to be H3K4,H3K9,and H3K27.Histone methylation affects gene expression and regulates stem cell differentiation by maintaining a delicate balance between major trimethylation sites,generating distinct chromatin structures associated with specific downstream transcriptional states.Several crucial signaling pathways associated with osteogenic differentiation are susceptible to modulation via histone methylation modifications.A deeper understanding of the regulatory mechanisms governing histone methylation modifications in osteo-/odontogenic differentiation and immune-inflammatory responses of DMSCs will facilitate further investigation of the epigenetic regulation of histone methylation in DMSC-mediated tissue regeneration and inflammation.Here is a concise overview of the pivotal functions of epigenetic histone methylation at H3K4,H3K9,and H3K27 in the regulation of osteo-/odontogenic differentiation and renewal of DMSCs in both non-inflammatory and inflammatory microenvironments.This review summarizes the current research on these processes in the context of tissue regeneration and therapeutic interventions.
文摘BACKGROUND： Morphological data have shown that the most important afferent fibers of papillary body come from hippocampal structure.OBJECTIVE： To observe the changes of evoked potential in hippocampus and the significance after electrostimulation at medial mamillary nucleus. DESIGN： An observational control experiment.SETTING： Department of Physiology, Shenyang Medical College.MATERIALS ： Twenty-three male or female Wistar rats, 3-4 months old, weighing 270-350 g, were provided by bhe animal room of Shenyang Medical College [the license number was scxk（Liao）2003-0016]. METHODS： The Wistar rats were anaesthetized by intraperintoneal injection of 20% urethane （1 g/kg）, tracheal intubation was also given. The self-made double-pole metal stimulating electrode with the point diameter of 1 mm was inserted into medial mamillary nucleus, the wanted hippocampal guidance spot was found within the rang of the hippocampal region at the same side of tee mamillary body range （CA1-CA4）, inserted with same-core guidance electrode, a sole square-wave stimulation of wave wide 0.2 ms stimulated with electrodes at the applied intensity of 7-9 V, the evoked potential was induced through guidance electrodes, and then input to the ATAC-350 data-processing machine for memory showing wave processing, the memory recorded wave recording graph was separately drawn up by the X-Y recording instrument to observe the latency, time procedure and amplitude of the evoked potential in each hippocampal region of the rats and calculate the percentage of the evoked potential in each hippocampal region. Totally 78 guidance spots in hippocampus were recorded, including 30 positive reaction spots and 48 negative ones. MAIN OUTCOME MEASURES： ① Latency, time procedure and amplitude of the evoked potentials in each hippocampal region of rats; ②percentage of the evoked potentials in each hippocampal region; ③ the wave shapes of the evoked potentials in each hippocampal region from different arrangement in the same positive reaction spot. RESULTS ：① Of the 30 recorded positive reactions, 9 positive spots fused into the stimulated false marks because of the short latency. The analysis of variance showed that the latency had significant difference （P 〈 0.05）, time procedure had highly significant difference （P 〈 0.01 ）, but there was no significant difference in the amplitude （P 〉 0.05） among the hippampal regions.② Among the 30 positive spots, the percentage of evoked potential in the hippocampal regions were 34.5% for CA1, 2.0% for CA2, 24.1% for CA3 and 22.4% for CA4. ③ In different levels of the same positive spot, different changes of the evoked potential wave shapes could be observed, and the most obvious change was that of positive wave amplitude. At different positive spots, evoked potentials of positive phase, negative and the double-phase could be observed. CONCLUSION： There are nerve associations between mamillary body and hippocampus, afferent fibers of mamillary body come from hippocampal CA1 region are a little more.
