Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling. Here, we focused on the role of Semaphorin 3A (Sema3A), expressed by sensory nerves, in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement (OTM) model. Firstly, bone formation was activated after the 3rd day of OTM, coinciding with a decrease in sensory nerves and an increase in pain threshold. Sema3A, rather than nerve growth factor (NGF), highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM. Moreover, in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells (hPDLCs) within 24 hours. Furthermore, exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload. Mechanistically, Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway, maintaining mitochondrial dynamics as mitochondrial fusion. Therefore, Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation, both as a pain-sensitive analgesic and a positive regulator for bone formation.
Humans ; Bone Remodeling ; Cell Differentiation ; Osteogenesis ; Semaphorin-3A/pharmacology* ; Trigeminal Ganglion/metabolism*

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Objective:To validate the morphological changes of the parieto-occipital sulcus on the transcalvarial axial plane between 20 and 32 weeks of gestation, simplify grade for assessing fetal parieto-occipital sulcus development, and confirm its clinical feasibility.Methods:This was a cross-sectional study analysis that included 550 cases of normal singleton fetuses between 20 and 32 weeks of gestation, who underwent routine ultrasound examinations at Shenzhen Maternity and Child Healthcare Hospital from September 2019 to June 2022. The morphological changes of the bilateral parieto-occipital sulci on the transcalvarial axial plane were observed. The development of the parieto-occipital sulcus was classified into 6 grades based on the developmental features of angulation, progressive closure, and curvilinear growth: straight or shallow arcuate (Grade 0), shallow and wide V-shaped (Grade 1), deep and narrow V-shaped (Grade 2), Y-shaped (Grade 3), I-shaped (Grade 4), and curvilinear (Grade 5). The gestational age at examination and pregnancy outcomes were recorded. The distribution of gestational weeks for fetuses with different grades of parieto-occipital sulci on the left and right sides was analyzed. The symmetry between bilateral parieto-occipital sulcus gradings within individuals, as well as the inter-observer and intra-observer reliability were assessed using the Weighted Kappa coefficient. The gender differences in asymmetry of parieto-occipital sulci grades between the left and right sides was analyzed. Moreover, a model for predicting the grade of the parieto-occipital sulcus based on gestational week was established.Results:Grade for the left parieto-occipital sulcus was obtained for 549 fetuses, while grade for the right was obtained for 550 fetuses. From 20 to 32 weeks of gestation, the morphology of the fetal parieto-occipital sulcus was divided into Grade 0-5, progressing from low to high with gestational development. Grade 0 showed that the sulcus was not visible or only had a slight arcuate indentation, occurring at 20-22 weeks; Grade 1 presented as a shallow and wide "V" shape with an obtuse angle at the top, appearing from 20 to 27 weeks; Grade 2 was a deep and narrow "V" shape with an acute angle at the top, appearing from 24 to 29 weeks; Grade 3 appeared as a "Y" shape with the top part partially closed and the bottom still open, occurring between 26 to 30 weeks; Grade 4 was a fully closed "I" shape, appearing at 29-32 weeks; Grade 5 presented as a curved shape, indicating the parieto-occipital sulcus was approaching maturity, appearing from 31 to 32 weeks. There was no statistically significant difference in the distribution of gestational weeks for bilateral parieto-occipital sulcus developmental grade ( P>0.05). Bilateral parieto-occipital sulcus grade could be assessed in 549 fetuses, of which 43 cases (7.83%) exhibited grade asymmetry with a one-grade difference between sides; such asymmetry showed no significant difference between male and female genders ( P=0.647). The weighted kappa coefficient analysis results indicated a strong consistency in the development of the parieto-occipital sulci on both sides within individuals, generally demonstrating symmetrical development ( P<0.001). The intra-observer and inter-observer weighted kappa coefficients were 0.92 and 0.75, respectively, with good consistency. Conclusions:Prenatal ultrasound via the transcalvarial axial plane enables a preliminary and rapid assessment of the development of bilateral parieto-occipital sulci, facilitating early evaluation of fetal cortical maturation.

Objective:To study the stability and morphological changes of the convexity sulci in normal fetuses between 20 and 32 weeks, and to explore the simplified grade for evaluating the convexity sulci development and analyzing its clinical significance.Methods:This study was a cross-sectional analysis. A total of 551 cases of normal singleton pregnancies between 20 and 32 weeks of gestation were retrospectively collected, who underwent routine ultrasound examinations at Shenzhen Maternity and Child Healthcare Hospital from September 2019 to June 2022. The display of the far-field convexity sulci on the transcalvarial axial plane was observed as 0 for not displayed and 1 for displayed.Further, based on the morphology and number of convexity sulci, they were classified into five grades: no sulcus displayed (grade 0), one sulcus (grade 1), two sulci (grade 2), three sulci (grade 3), and four or more sulci (grade 4). The gestational age at examination and pregnancy outcomes were recorded. The distribution characteristics of gestational weeks for each grade of the convexity sulci were analyzed, and the gestational week distribution of the left and right convexity sulci was compared to analyze bilateral symmetry. The Weighted Kappa coefficient was used to analyze inter-observer and intra-observer consistency, and curve regression analysis was employed to establish a model for predicting grade based on gestational weeks.Results:Before 25 weeks of gestation, the convexity of the fetal cranial vertex was completely smooth.The central sulcus consistently appeared after 26 weeks, while the superior frontal sulcus, intraparietal sulcus, postcentral sulcus, and precentral sulcus consistently appeared between 28 and 31 weeks. Among these, the superior frontal sulcus had a lower display rate before 29 weeks. By 32 weeks, all convexity sulci of the cranial vertex should be visible. Three hundred and eleven fetuses were graded for the left, and 240 fetuses were graded for the right. The developmental grade of the convexity sulci increased from Grade 0 to Grade 4 as the gestational age progressed. Grade 0 appeared between 20-26 weeks, grade 1 between 25-28 weeks, grade 2 between 26-28 weeks, grade 3 between 27-30 weeks, and grade 4 between 27-32 weeks. The distribution of grade did not differ significantly between the left and right sides of grade 0, 1, 3 and 4 (all P>0.05), while there was a significant difference in the distribution of gestational age between the convexity sulci of grade 2 ( P<0.05). The Weighted Kappa coefficients for intra-observer and inter-observer consistency were 0.94 and 0.86, respectively, indicating strong consistency. Conclusions:The simplified grade for assessing the development of convexity sulci in normal fetuses on the transcalvarial axial plane via prenatal ultrasound can provide a preliminary evaluation of the maturation of convexity sulci in fetuses between 20 and 32 weeks of gestation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.