miR-20a: a key regulator of orthodontic tooth movement via BMP2 signaling pathway modulation.

AIM: In this study, we aimed to establish a rat tooth movement model to assess miR-20's ability in enhancing the BMP2 signaling pathway and facilitate alveolar bone remodeling. METHOD: 60 male SD rats had nickel titanium spring devices placed between their left upper first molars and incisors, with the right side serving as the control. Forces were applied at varying durations (18h, 24h, 30h, 36h, 42h, 1d, 3d, 5d, 7d, 14d), and their bilateral maxillary molars and surrounding alveolar bones were retrieved for analysis. Fluorescent quantitative PCR was conducted to assess miR-20a, BMP2, Runx2, Bambi and Smad6 gene expression in alveolar bone, and western blot was performed to determine the protein levels of BMP2, Runx2, Bambi, and Smad6 after mechanical loading. RESULT: We successfully established an orthodontic tooth movement model in SD rats and revealed upregulated miR-20a expression and significantly increased BMP2 and Runx2 gene expression and protein synthesis in alveolar bone during molar tooth movement. Although Bambi and Smad6 gene expression did not significantly increase, their protein synthesis was found to decrease significantly. CONCLUSION: MiR-20a was found to be involved in rat tooth movement model alveolar bone remodeling, wherein it promoted remodeling by reducing Bambi and Smad6 protein synthesis through the BMP2 signaling pathway.

The efficacy and safety of combined therapy with endobronchial tamponade and bronchial artery embolization for massive hemoptysis.

BACKGROUND: Massive hemoptysis is characterized by its life-threatening nature, potentially leading to airway obstruction and asphyxia. The objective of this study was to evaluate the clinical effectiveness of combining endobronchial tamponade with bronchial artery embolization (BAE) in the treatment of massive hemoptysis. METHODS: Between March 2018 and March 2022, a total of 67 patients with massive hemoptysis who underwent BAE were divided into two groups: the combination group (n = 26) and the BAE group (n = 41). Technical and clinical success rates were assessed, and adverse events were monitored following the treatment. Blood gas analysis and coagulation function indicators were collected before and after the treatment, and recurrence and survival rates were recorded during the follow-up period. RESULTS: All patients achieved technical success. There were no significant differences in the clinical success rate, recurrence rates at 3 and 6 months, and mortality rates at 3 months, 6 months, and 1 year between the combination group and the BAE group. However, the hemoptysis recurrence rate at 1 year was significantly lower in the combination group compared to the BAE group (15.4% vs. 39.0%, P = 0.039). No serious adverse events were reported in either group. After treatment, the combination group showed higher levels of arterial partial pressure of oxygen (PaO2), oxygenation index (PaO2/FiO2), fibrinogen (FIB), and D-dimer (D-D) compared to the BAE group (P < 0.05). Multivariate regression analysis demonstrated a significant correlation between combined therapy and hemoptysis-free survival. CONCLUSION: Combination therapy, compared to embolization alone, exhibits superior efficacy in improving respiratory function, correcting hypoxia, stopping bleeding, and preventing recurrence. It is considered an effective and safe treatment for massive hemoptysis.

A comprehensive microsatellite landscape of human Y-DNA at kilobase resolution.

BACKGROUND: Though interest in human simple sequence repeats (SSRs) is increasing, little is known about the exact distributional features of numerous SSRs in human Y-DNA at chromosomal level. Herein, totally 540 maps were established, which could clearly display SSR landscape in every bin of 1 k base pairs (Kbp) along the sequenced part of human reference Y-DNA (NC_000024.10), by our developed differential method for improving the existing method to reveal SSR distributional characteristics in large genomic sequences. RESULTS: The maps show that SSRs accumulate significantly with forming density peaks in at least 2040 bins of 1 Kbp, which involve different coding, noncoding and intergenic regions of the Y-DNA, and 10 especially high density peaks were reported to associate with biological significances, suggesting that the other hundreds of especially high density peaks might also be biologically significant and worth further analyzing. In contrast, the maps also show that SSRs are extremely sparse in at least 207 bins of 1 Kbp, including many noncoding and intergenic regions of the Y-DNA, which is inconsistent with the widely accepted view that SSRs are mostly rich in these regions, and these sparse distributions are possibly due to powerfully regional selection. Additionally, many regions harbor SSR clusters with same or similar motif in the Y-DNA. CONCLUSIONS: These 540 maps may provide the important information of clearly position-related SSR distributional features along the human reference Y-DNA for better understanding the genome structures of the Y-DNA. This study may contribute to further exploring the biological significance and distribution law of the huge numbers of SSRs in human Y-DNA.

Naotaifang III Protects Against Cerebral Ischemia Injury Through LPS/TLR4 Signaling Pathway in the Microbiota-Gut-Brain Axis.

Background: Ischemic stroke (IS) is a leading cause of mortality worldwide. Naotaifang III is a new Chinese herbal formula to treat IS. Previous studies have shown that Astragali Radix, Puerariae Lobatae Radix, Chuanxiong Rhizoma, and Rhei Radix Et Rhizoma in Naotaifang III were able to regulate the imbalance of intestinal microbiota during cerebral ischemia injury. Methods: Rats were randomly divided into sham operation group, normal control group, middle cerebral artery occlusion (MCAO) group, intestinal microbiota imbalance MCAO group, Naotaifang III group, and normal bacteria transplantation group, with 15 rats in each group. Then, neurological function scores and cerebral infarction volume were detected; haematoxylin and eosin staining and Golgi silver staining were used to observe morphological changes in brain tissue. Meanwhile, the lipopolysaccharide (LPS) and cerebral cortex interleukin (IL)-1ß were detected by enzyme-linked immunosorbent assay (ELISA); the expressions of Toll-like receptor (TLR)-4 and nuclear factor kappa-B (NF-κB) proteins were detected by immunofluorescence and Western blot. The cecal flora was detected by 16S rDNA. The results showed that gut dysbiosis aggravated cerebral ischemic injury and significantly increased the expression of LPS, TLR4, NF-κB, and IL-1ß, which could be significantly reversed by Naotaifang III or normal bacterial transplantation. Naotaifang III may exert a protective effect on neuroinflammatory injury after MCAO through the LPS/TLR4 signaling pathway in the microbe-gut-brain axis. In summary, Naotaifang III may induce anti-neuroinflammatory molecular mechanisms and signaling pathways through the microbe-gut-brain axis. Results: The results showed that gut dysbiosis aggravated cerebral ischemic injury and significantly increased the expression of LPS, TLR4, NF-κB, and IL-1ß, which could be significantly reversed by Naotaifang III or normal bacterial transplantation. Naotaifang III may exert a protective effect on neuroinflammatory injury after MCAO through the LPS/TLR4 signaling pathway in the microbe-gut-brain axis. Conclusion: Naotaifang III may induce anti-neuroinflammatory molecular mechanisms and signaling pathways through the microbe-gut-brain axis.

A two-year retrospective study on traumatic dental injury in the primary dentition.

The aim of this study was to analyze the causes, clinical characteristics, social factors, and current status of treatment of traumatic dental injury (TDI) in the primary dentition. A retrospective analysis was performed on 144 children (213 teeth) with TDI in the primary dentition from our hospital between December 2017 and June 2020. Data were analyzed using the chi-square test and the Mann-Withney-Wilcoxon test. Boys accounted for 68.1% (98/144) and girls for 31.9% (46/144) of all 144 children with TDI in the primary dentition, with a boy-girl ratio of 2.13:1. The primary age of TDI in deciduous teeth was 2 to 4 years old, accounting for 59% of all cases. Collision with others and fall were the 2 main causes of trauma to the deciduous teeth, making up 52.1% and 44.4% of all causes, respectively. Crown fracture injury was the most common type of TDI in the primary dentition, accounting for 37% of all cases (53/144). Of the 144 cases, 17.4% (25/144) was accompanied by soft tissue laceration, while 22.2% (32/144) by swelling or contusion of tissue. Maxillary teeth (92.4%) were more vulnerable to injury than mandibular teeth (7.5%), with maxillary incisor being the most vulnerable 1 (91.5%). The percentage of children arrived at the hospital for treatment 24 hours after the injury was the highest (57.0%, 82/144). After the hospital visit, 74.3% of children received treatment for the dental trauma. In terms of the treatment modalities, extraction of the traumatized teeth (27.1%) and pulpectomy + resin filling (or preformed crown) restoration were predominant. Approximately 28.5% (41/144) of cases were reviewed within 2 years, with the proportion of children with pulpitis or periapical infection being the highest (29.3%, 12/41). Age, gender, collision, and fall are the factors linked to a higher risk of TDI in the primary dentition in children under the age of 7. Resin filling (or preformed crown) restoration and pulpectomy are effective in preserving the affected tooth and controlling infection. However, the preservation of the affected tooth and the prevention of infection may be hampered by late visits and low follow-up rates.

MiR-20a promotes osteogenic differentiation in bone marrow-derived mesenchymal stem/stromal cells and bone repair of the maxillary sinus defect model in rabbits.

Introduction: This study aimed to determine whether miR-20 promoted osteogenic differentiation in bone marrow-derived mesenchymal stem/stromal cells (BMSCs) and accelerated bone formation in the maxillary sinus bone defect model in rabbits. Methods: BMSCs were transfected with miR-20a or anti-miR-20a for 12 h, followed by detection of RUNX2, Sp7 mRNA, bone morphogenetic protein 2 (BMP2), and RUNX2 protein expression. Alkaline phosphatase (ALP) activity and Alizarin Red S staining were used to detect calcified nodule deposition. In the rabbit maxillary sinus bone defect model, miR-20a loaded with AAV and BMP2 protein were mixed with Bio-Oss bone powder for filling the bone defect. At 4 weeks and 8 weeks, bone density was detected by cone beam computed tomography (CBCT), and new bone, osteoblasts, and collagen type 1 were evaluated by hematoxylin and eosin (HE) staining and immunohistochemical (IHC) staining. Results: Overexpression of miR-20a enhanced the mRNA and protein levels of BMP2, RUNX2, and SP7, the activity of ALP, and the levels of matrix mineralization, whereas the levels and activity of the aforementioned factors were decreased by anti-miR-20a treatment of BMSCs. Furthermore, miR-20a significantly increased the bone density, the number of osteoblasts, and the secretion of collagen type 1 in bone defects compared with Bio-Oss bone powder in the rabbit maxillary sinus bone defect model. Conclusion: Overall, miR-20a can induce osteogenic differentiation in BMSCs and accelerate bone formation of maxillary sinus defects in rabbits.

MiR-20a: a mechanosensitive microRNA that regulates fluid shear stress-mediated osteogenic differentiation via the BMP2 signaling pathway by targeting BAMBI and SMAD6.

Background: MicroRNAs (miRNAs) are crucial regulators of diverse biological and pathological processes. This study aimed to investigate the role of microRNA 20a (miR-20a) in fluid shear stress (FSS)-mediated osteogenic differentiation. Methods: In the present study, we subjected osteoblast MC3T3-E1 cells or mouse bone marrow stromal cells (BMSCs) to single bout short duration FSS (12 dyn/cm2 for 1 hour) using a parallel plate flow system. The expression of miR-20a was quantified by miRNA array profiling and real-time quantitative polymerase chain reaction (qRT-PCR) during FSS-mediated osteogenic differentiation. The expression of osteogenic differentiation markers such as Runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), and SP7 transcription factor (SP7) was detected. Bioinformatics analysis and a luciferase assay were performed to confirm the potential targets of miR-20a. Results: Osteoblast-expressed miR-20a is sensitive to the mechanical environments of FSS, which are differentially up-regulated during steady FSS-mediated osteogenic differentiation. MiR-20a enhances FSS-induced osteoblast differentiation by activating the bone morphogenetic protein 2 (BMP2) signaling pathway. Both BMP and activin membrane-bound inhibitor (BAMBI) and mothers against decapentaplegic family member 6 (SMAD6) are targets of miR-20a that negatively regulate the BMP2 signaling pathway. Conclusions: MiR-20a is a novel mechanosensitive miRNA that can enhance osteoblast differentiation in FSS mechanical environments, implying that this miRNA might be a target for bone tissue engineering and orthodontic bone remodeling for regenerative medicine applications.

Increased risk of periodontitis occurrence in patients with rheumatoid arthritis and its association with the levels of IL-1ß and TNF-α in gingival crevicular fluid.

BACKGROUND: Periodontitis (PD) is a chronic inflammatory disease caused by infection of the periodontal supporting tissues. Clinical studies have reported that rheumatoid arthritis (RA) patients have a higher prevalence of PD. This study aimed to explore the correlation between RA and PD. METHODS: A total of 307 RA patients (RA group) and 324 healthy individuals (control group) who received physical examinations during the same period were recruited to this study. The incidence of PD in the two groups was analyzed, and the periodontal disease index (PDI) and bleeding on probing (BOP) were recorded. Then, 42 RA patients with PD and 56 control group patients with PD were selected for further analysis. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of interleukin 1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) in the gingival crevicular fluid (GCF) of the two groups. For patients with both RA and PD, the level of serum C-reactive protein (CRP) and the duration of morning stiffness were also recorded. RESULTS: The prevalence of PD in the RA group (51.5%) was significantly higher than that in the control group (31.2%), and the prevalence of PD also increased notably with the increase of age and the duration of the disease in RA patients. The levels of TNF-α and IL-1ß in the PDI and the GCF in the concurrent RA and PD group were significantly higher than those in the PD group (P<0.05). Partial correlation analysis showed that TNF-α in the GCF positively correlated with the BOP of patients with RA and PD. Multiple linear regression analysis showed that the level of TNF-α in the GCF and serum CRP were independent influencing factors of the level of IL-1ß in the GCF (the r values were 1.074 and 3.851, respectively; P<0.01). CONCLUSIONS: The presence of RA can increase risk of PD occurrence and is positively correlated with the levels of IL-1ß and TNF-α in the GCF.

Suppressing MicroRNA-30b by Estrogen Promotes Osteogenesis in Bone Marrow Mesenchymal Stem Cells.

MicroRNAs (miRNAs) have been widely demonstrated to interact with multiple cellular signaling pathways and to participate in a wide range of physiological processes. Estradiol-17ß (E2) is the most potent and prevalent endogenous estrogen that plays a vital role in promoting bone formation and reducing bone resorption. Currently, little is known about the regulation of miRNAs in E2-induced osteogenic differentiation. In the present study, the primary bone marrow mesenchymal stem cells from rats (rBMSCs) were isolated and incubated with E2, followed by miRNA profiling. The microarray showed that 29 miRNAs were differentially expressed in response to E2 stimulation. Further verification by real-time reverse-transcriptase polymerase chain reaction revealed that E2 enhanced the expression of let-7b and miR-25 but suppressed the miR-30b expression. Moreover, a gain-of-function experiment confirmed that miR-30b negatively regulated the E2-induced osteogenic differentiation. These data suggest an important role of miRNAs in osteogenic differentiation.

Cyclical compressive stress induces differentiation of rat primary mandibular condylar chondrocytes through phosphorylated myosin light chain II.

The role of myosin light chain II (MLC­II) in cellular differentiation of rat mandibular condylar chondrocytes (MCCs) induced by cyclical uniaxial compressive stress (CUCS) remains unclear. In the current study, a four­point bending system was used to apply CUCS to primary cultured MCCs from rats. It was identified that CUCS stimulated features of cellular differentiation including morphological alterations, cytoskeleton rearrangement and overproduction of proteoglycans. Furthermore, CUCS promoted runt­related transcription factor­2 (RUNX2) expression at mRNA (P<0.01) and protein levels (P<0.05) and elevated alkaline phosphatase (ALP) activity (P<0.01), which are both markers of osteogenic differentiation. Under conditions of stress, western blotting indicated that the ratio of phosphorylated MLC­II to total MLC­II was increased significantly (P<0.05). Silencing MLC­II by RNA interference reduced ALP activity (P<0.01), and eliminated RUNX2 mRNA expression (P<0.01). Addition of the MLC kinase inhibitor, ML­7, reduced the CUCS­associated upregulation of RUNX2 expression (P<0.01) and ALP activity (P<0.01). The data indicated that CUCS promoted cellular differentiation of rat primary MCCs, and this was suggested to be via the phosphorylation of MLC­II.

Fluid shear stress stimulates osteogenic differentiation of human periodontal ligament cells via the extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase signaling pathways.

BACKGROUND: Fluid shear stress (FSS) is a major type of mechanical stress that is loaded on human periodontal ligament cells (hPDLCs) during mastication and orthodontic tooth movement. This study aims to clarify the effect of FSS on the osteogenic differentiation of hPDLCs and to further verify the involvement of mitogen-activated protein kinase (MAPK) signaling in this process. METHODS: After isolation and characterization, hPDLCs were subjected to 2-hour FSS at 12 dynes/cm(2), and cell viability, osteogenic gene mRNA expression, alkaline phosphatase (ALP) activity, secretion of Type I collagen (COL-I), and calcium deposition were assayed. The levels of phosphorylated p38 and phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) in response to FSS were detected by Western blot, and the involvement of ERK1/2 and p38 MAPK signaling pathways in hPDLC osteogenesis under FSS was investigated using the specific MAPK inhibitors U0126 (2Z,3Z)-2,3-bis[amino(2-aminophenylthio)methylene]succinonitrile,ethanol) and SB203580 (4-[4-(4-fluorophenyl)-2-(4-[methylsulfinyl]phenyl)-1H-imidazol-5-yl]pyridine). RESULTS: The application of FSS on hPDLCs induced an early morphologic change and rearrangement of filamentous actin. ALP activity, messenger RNA (mRNA) levels of osteogenic genes, COL-I, and osteoid nodules were significantly increased by FSS. Moreover, ERK1/2 and p38 were activated in different ways after FSS exposure. U0126 and SB203580 completely blocked the FSS-induced increases in ALP activity and osteogenic gene mRNA expression and osteoid nodules formation. CONCLUSIONS: FSS is an effective approach for stimulating osteogenic differentiation of hPDLCs. The ERK1/2 and p38 MAPK signaling pathways are involved in this cellular process.

Single bout short duration fluid shear stress induces osteogenic differentiation of MC3T3-E1 cells via integrin ß1 and BMP2 signaling cross-talk.

Fluid shear stress plays an important role in bone osteogenic differentiation. It is traditionally believed that pulsed and continuous stress load is more favorable for fracture recovery and bone homeostasis. However, according to our clinical practice, we notice that one single stress load is also sufficient to trigger osteogenic differentiation. In the present study, we subject osteoblast MC3T3-E1 cells to single bout short duration fluid shear stress by using a parallel plate flow system. The results show that 1 hour of fluid shear stress at 12 dyn/cm(2) promotes terminal osteogenic differentiation, including rearrangement of F-actin stress fiber, up-regulation of osteogenic genes expression, elevation of alkaline phosphatase activity, secretion of type I collagen and osteoid nodule formation. Moreover, collaboration of BMP2 and integrin ß1 pathways plays a significant role in such differentiation processes. Our findings provide further experimental evidence to support the notion that single bout short duration fluid shear stress can promote osteogenic differentiation.

miRNA expression profile during fluid shear stress-induced osteogenic differentiation in MC3T3-E1 cells.

BACKGROUND: Mechanical stress plays an important role in the maintenance of bone homeostasis. Current hypotheses suggest that interstitial fluid flow is an important component of the system by which tissue level strains are amplified in bone. This study aimed to test the hypothesis that the short-term and appropriate fluid shear stress (FSS) is expected to promote the terminal differentiation of pre-osteoblasts and detect the expression profile of microRNAs in the FSS-induced osteogenic differentiation in MC3T3-E1 cells. METHODS: MC3T3-E1 cells were subjected to 1 hour of FSS at 12 dyn/cm(2) using a parallel plate flow system. After FSS treatment, cytoskeleton immunohistochemical staining and microRNAs (miRNAs) were detected immediately. Osteogenic gene expression and immunohistochemical staining for collagen type I were tested at the 24th hour after treatment, alkaline phosphatase (ALP) activity assay was performed at 24th, 48th, and 72 th hours after FSS treatment, and Alizarin Red Staining was checked at day 12. RESULTS: One hour of FSS at 12 dyn/cm(2) induced actin stress fiber formation and rearrangement, up-regulated osteogenic gene expression, increased ALP activity, promoted synthesis and secretion of type I collagen, enhanced nodule formation, and promoted terminal differentiation in MC3T3-E1 cells. During osteogenic differentiation, expression levels of miR-20a, -21, -19b, -34a, -34c, -140, and -200b in FSS-induced cells were significantly down-regulated. CONCLUSION: The short-term and appropriate FSS is sufficient to promote terminal differentiation of pre-osteoblasts and a group of miRNAs may be involved in FSS-induced pre-osteoblast differentiation.