RANKL+ senescent cells under mechanical stress: a therapeutic target for orthodontic root resorption using senolytics / 国际口腔科学杂志·英文版

In dentistry, orthodontic root resorption is a long-lasting issue with no effective treatment strategy, and its mechanisms, especially those related to senescent cells, remain largely unknown. Here, we used an orthodontic intrusion tooth movement model with an L-loop in rats to demonstrate that mechanical stress-induced senescent cells aggravate apical root resorption, which was prevented by administering senolytics (a dasatinib and quercetin cocktail). Our results indicated that cementoblasts and periodontal ligament cells underwent cellular senescence (p21+ or p16+) and strongly expressed receptor activator of nuclear factor-kappa B (RANKL) from day three, subsequently inducing tartrate-resistant acid phosphatase (TRAP)-positive odontoclasts and provoking apical root resorption. More p21+ senescent cells expressed RANKL than p16+ senescent cells. We observed only minor changes in the number of RANKL+ non-senescent cells, whereas RANKL+ senescent cells markedly increased from day seven. Intriguingly, we also found cathepsin K+p21+p16+ cells in the root resorption fossa, suggesting senescent odontoclasts. Oral administration of dasatinib and quercetin markedly reduced these senescent cells and TRAP+ cells, eventually alleviating root resorption. Altogether, these results unveil those aberrant stimuli in orthodontic intrusive tooth movement induced RANKL+ early senescent cells, which have a pivotal role in odontoclastogenesis and subsequent root resorption. These findings offer a new therapeutic target to prevent root resorption during orthodontic tooth movement.

Research Advance of BCR-ABL Mutation and the Efficacy of Second and Third Generation TKI in Chronic Myeloid Leukemia--Review / 中国实验血液学杂志

The treatment of chronic myeloid leukemia (CML) was revolutionized with the advent of the first-generation tyrosine kinase inhibitors (TKIs), but drug resistance developed during treatment, leading to the development of the second-generation (dasatinib, nilotinib, and bosutinib) and third-generation (ponatinib) TKI. Compared with previous treatment regimens, specific TKI can significantly improve the response rate, overall survival rate and prognosis of CML. Only a few patients with BCR-ABL mutation are insensitive to the second-generation TKIs, so it is suggested to select the second-generation TKIs for patients with specific mutations. For patients with other mutations and without mutations, the second-generation TKI should be selected according to the patient's medical history, while the third-generation TKIs should be selected for mutations that are insensitive to the second-generation TKIs, such as T315I mutation that is sensitive to ponatinib. Due to different BCR-ABL mutations in patients with different sensitivity to the second and third-generation TKIs, this paper will review the latest research progress of the efficacy of the second and third-generation TKIs in CML patients with BCR-ABL mutations.

Effects of Dasatinib on the Maturation of Monocyte-Derived Dendritic Cells Derived from Healthy Donors and Chronic Myelogenous Leukemia Patients / 中国实验血液学杂志

OBJECTIVE@#To investigate the effects of dasatinib on the maturation of monocyte-derived dendritic cells (moDCs) derived from healthy donors (HDs) and chronic myelogenous leukemia (CML) patients.@*METHODS@#Peripheral blood mononuclear cells (PBMCs) were isolated from HDs (n=10) and CML patients (n=10) who had got the remission of MR4.5 with imatinib treatment. The generation of moDCs from PBMCs was completed after 7 days of incubation in DC I culture medium, and another 3 days of incubation in DC II culture medium with or without 25 nmol/L dasatinib. On the 10th day, cells were harvested and expression of molecules of maturation related marker were assessed by flow cytometry. The CD80+CD86+ cell population in total cells was gated as DCs in the fluorescence-activated cell storting (FACS) analyzing system, then the expression of CD83, CD40 or HLA-DR in this population was analyzed respectively.@*RESULTS@#The proportion of CD80+CD86+ cells in total cells didn't show a statistical difference between HD group and patient group (89.46%±9.70% vs 87.39%±9.34%, P=0.690). Dasatinib significantly enhanced the expression of the surface marker CD40 (P=0.008) and HLA-DR (P=0.028) on moDCs derived from HDs compared with the control group, while the expression of CD83 on moDCs didn't show a significant difference between dasatinib group and the control group (P=0.428). Meanwhile, dasatinib significantly enhanced the expression of the surface marker CD40 (P=0.023), CD83 (P=0.038) and HLA-DR (P=0.001) on moDCs derived from patients compared with the control group.@*CONCLUSION@#For CML patients, the same high proportion of moDCs as HDs can be induced in vitro, which provides a basis for the application of DC-based immunotherapy strategy. Dasatinib at the concentration of 25 nmol/L can efficiently promote the maturation of moDCs derived from HDs and CML patients in vitro. Dasatinib shows potential as a DC adjuvant to be applied in DC-based immunotherapy strategies, such as DC vaccine and DC cell-therapy.