The molar anchorage control in orthodontic treatment is a key concern of clinicians and a hot spot in the field of orthodontic clinical research.Good molar anchorage control is a prerequisite for the success of orthodontic treatment.In recent years,clear aligner treatment has been favored by orthodontists and patients because of its aesthetics,comfort and other advantages.However,the unique biomechanical mechanism of clear aligner system has brought new changes and challenges for dentists to understand the anchorage con-trol in orthodontics.This article provides a systematic review of the research methodology,clinical efficacy and enhanced strategy of mo-lar anchorage control in clear aligner treatment,with the aim to provide a reference for the clinical research and technical development of molar anchorage control in clear aligner treatment.

Objective:To investigate the mechanism of proanthocyanidin (PA) in regulating the osteogenic differentiation of human periodontal ligament stem cells (PDLSCs), and to explore the effects of PA on the expression and nuclear translocation of transcription factor EB (TFEB) and on the autophagy-lysosome pathway.Methods:PDLSCs were divided into control group and PA group, which were subjected to RNA sequencing analysis (RNA Seq) to detect differentially expressed genes. The osteogenic differentiation ability and autophagy level were observed by real-time fluorescence quantitative PCR (RT-qPCR) analysis, alkaline phosphatase (ALP) staining and transmission electron microscope (TEM), respectively. Scratch assay and Transwell assay were used to detect the migration ability of PDLSCs. Lysotracker and immunofluorescence staining were used to detect the biogenesis of lysosomes. The total protein expression of transcription factor EB (TFEB) as well as that in cytoplasm and nucleus were detected by Western blotting. Confocal laser scanning microscope (CLSM) was used to observe the nuclear translocation of TFEB. The PDLSCs were treated with small interfering RNA (siRNA) technology to knock down the expression levels of TFEB gene with or without PA treatment. Western blotting was used to analyze the expressions of autophagy-related proteins Beclin1 and microtubule-associated protein 1 light chain 3 (LC3B), as well as osteogenic-related proteins runt-related transcription factor 2 (RUNX2), ALP, and osteocalcin in PDLSCs.Results:Compared with the control group, the osteogenic-related and autophagy-related genes showed differential expression in PDLSCs after PA treatment ( P<0.05). The mRNA expression levels of osteogenic-related genes RUNX2 (2.32±0.15) and collagen type Ⅰ alpha 1 (COL1α1) (1.80±0.18), as well as the autophagy related genes LC3B (1.87±0.08) and Beclin1 (1.63±0.08) were significantly increased in the PA group, compared with the control group (1.01±0.16, 1.00±0.10, 1.00±0.07, 1.00±0.06, respectively, all P<0.01). Compared with the control group, the PA group had higher ALP activity, and more autophagosomes and autophagolysosomes observed by TEM. PA promoted the migration of PDLSCs ( P<0.05) and the increased number of lysosomes and the expression of lysosomal associated membrane protein 1 (LAMP1). In the PA group, the relative expression level of total TFEB protein (1.49±0.07) and the nuclear/cytoplasmic expression of TFEB protein (1.52±0.12) were significantly higher than the control group (1.00±0.11, 1.00±0.13, respectively) ( t=6.43, P<0.01; t=5.07, P<0.01). The relative nuclear/cytoplasmic fluorescence intensity of TFEB in the PA group (0.79±0.09) was increased compared with the control group (0.11±0.08) ( t=8.32, P<0.01). Knocking down TFEB significantly reduced the expression of TFEB (1.00±0.15 vs 0.64±0.04), LAMP1 (1.00±0.10 vs 0.69±0.09), Beclin1 (1.00±0.05 vs 0.60±0.05), and LC3B Ⅱ/Ⅰ (1.00±0.06 vs 0.73±0.07) in PDLSCs ( P<0.05, P<0.05, P<0.01, P<0.01). When TFEB gene was knocked down, the expression levels of Beclin1 (1.05±0.11), LC3B Ⅱ/Ⅰ (1.02±0.09), RUNX2 (1.04±0.10), ALP (1.04±0.16), and osteocalcin (1.03±0.15) proteins were significantly decreased in the PA group compared with the pre-knockdown period (1.28±0.03, 1.44±0.11, 1.38±0.11, 1.62±0.11, 1.65±0.17, respectively) ( P<0.05, P<0.01, P<0.05, P<0.01, and P<0.01, respectively). Conclusions:PA promotes the osteogenic differentiation of PDLSCs through inducing the expression and nuclear translocation of TFEB and activating the autophagy-lysosome pathway.

AIM: To reveal the ameliorative effect of salvianolic acid A on palmitie acid-induced lipotoxicity in H9C2 cells and to explore its potential molecular mechanisms preliminarily. METHODS: H9C2 cell were induced by palmitie acid to establish a lipotoxicity model, while salvianolic acid A was added prior to palmitie acid treatment. Lactate dehydrogenase (LDH) was employed to detect cell damage. Cell counting Kit-8 was used to detect cell viability. The changes of mitochondrial membrane potential in cardiomyocyte were observed by rhodamine 123 staining. The molecular mechanisms of the ameliorative effect of salvianolic acid A was analyzed by Western Blotting. RESULTS: Palmitie acid at a concentration of 400 μmol/L significantly caused lipotoxicity damage to H9C2 cells (P<0.05). There was no cytotoxic effect of different concentrations of salvianolic acid A (10, 20, 40, 80 μmol/L) treatment on H9C2 cells (P>0.05). Salvianolic acid A intervention significantly improved lipotoxicity-induced cell death and reduction of cell mitochondrial membrane potential (P<0.05). The activation of toll-like receptor 4 (TLR4) significantly enhanced lipotoxicity-induced cell damage (P<0.05), while inhibition of TLR4 significantly reduced palmitie acid-induced lipotoxicity (P<0.05). In addition, salvianolic acid A effectively inhibited the upregulation of TLR4 and the downstream c-Jun N-terminal kinase (JNK MAPK) of TLR4 by palmitie acid treatment (P<0.05). CONCLUSION: Salvianolic acid A effectively improves lipotoxicity-induced cardiomyocyte damage. The inhibition of p38 signaling pathway is potentially involved in its protective effect. The protective effect may be related to the inhibition of TLR4/JNK MAPK signaling pathway, providing a potential molecular target for the prevention and treatment of lipotoxic cardiomyopathy.