YBX1 Promotes MSC Osteogenic Differentiation by Activating the PI3K/AKT Pathway.

INTRODUCTION: Bone metabolism has an essential role in bone disease, but its specific mechanism remains unclear. Y-Box Binding Protein 1 (YBX1) is a gene with broad nucleic acid binding properties, which encodes a highly conserved cold shock domain protein. Previous studies have shown that YBX1 is closely related to cell differentiation. However, the function of YBX1 in osteoblast differentiation of bone marrow mesenchymal stem cells (MSCs) was unclear. METHODS: To explore the effect and specific mechanism of YBX1 in osteogenic differentiation of MSCs, we used PCR, Western blot, Alizarin red Staining, alkaline phosphatase (ALP) assays, and siRNA knockdown in our research. We found that YBX1 gradually increased during the process of osteogenic differentiation of MSCs. YBX1 siRNA could negatively regulate the MSCs osteogenic differentiation. Mechanistic studies revealed that YBX1 knockdown could inhibit PI3K/AKT pathway. Furthermore, the specific agonist (SC79) of PI3K/AKT pathway could restore the impaired MSCs osteogenic differentiation which was mediated by YBX1 knockdown. Taken together, we concluded that YBX1 could positively regulate the osteogenic differentiation of MSCs by activating the PI3K/AKT pathway. RESULTS AND DISCUSSION: These results helped us further understand the mechanism of osteogenesis and revealed that YBX1 might be a selectable target in the bone repair field. CONCLUSION: Our study provides a new target and theoretical basis for the treatment of bone diseases.

[Effect of indwelling drainage tube and extubation time on recessive hemorrhage and functional recovery after total hip arthroplasty].

OBJECTIVE: To study and compare the effect of indwelling drainage tube and extubation time on occult hemorrhage and functional recovery after total hip arthroplasty(THA). METHODS: From July 2017 to June 2018, 123 patients who underwent THA in our hospital for the first time were selected as the subjects of study. According to whether the drainage tube was retained or not and the time of extubation, they were divided into three groups:in group A, 41 patients (24 males, 17 females, age 53 to 77 years) did not put drainage tube after THA;in group B, 41 patients were removed 24 hours after THA, 26 males and 15 females, aged 55 to 74 years;in group C, 41 patients were removed 48 hours after THA, 25 males and 16 females, aged 52 to 75 years. The VAS score of pain 72 hours after THA, the total and recessive blood loss, the time of starting functional exercise, and the incidence of postoperative limb swelling were recorded. All the patients were followed up for one year after discharge. Harris hip score was used to evaluate the degree of hip function recovery one year after operation. RESULTS: The occult blood loss of group A, B and C were(513.6±25.3), (521.7±33.4), (519.3±29.8) ml, respectively, with no significant difference(P>0.05). There was no significant difference in blood loss in operation among the three groups(P>0.05). In group B and C, the postoperative apparent blood loss was more than that in group A (P<0.05). There was no significant difference in VAS scores of the three groups before and 72 hours after operation (P>0.05). The time of getting out of bed in group A was shorter than that in group B and C (P<0.05), and that in group B was shorter than that in group C(P<0.05). The Harris hip score at 1 year after operationof the three groups was significantly higher than that of before operation (P<0.05). There was no significant difference in Harris hip score before and after operation among three groups (P>0.05). There was no significant difference in the incidence of complications among three groups (P>0.05). CONCLUSION: Whether the drainage tube is left or not and the time of extubation have no significant effect on the latent blood loss and functional recovery after THA, but without drainage tube after THA can reduce the apparent blood loss, patients can get out of bed at 6 hours after THA, which is more conducive to the recovery and nursing of patients.