Association between serum soluble low-density lipoprotein receptor levels and metabolic factors in healthy Japanese individuals.

BACKGROUND: Soluble low-density lipoprotein receptor (sLDL-R) is formed by cleavage of the extracellular domain of low-density lipoprotein receptor (LDL-R). It is unclear whether serum sLDL-R is a marker of diseases associated with triglyceride (TG) metabolism. We investigated the association between serum sLDL-R concentrations and other biochemical parameters in healthy Japanese individuals. METHODS: Study subjects consisted of 102 healthy adult Japanese volunteers (42 men, 60 women) with body mass index (BMI) < 30 kg/m(2) and serum TGs, LDL cholesterol (LDL-C), aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transpeptidase, and glucose concentrations within normal ranges. Serum sLDL-R concentrations were determined by enzyme-linked immunosorbent assay and their correlations with biochemical parameters were analyzed. RESULTS: Mean serum sLDL-R concentration was 120.9 ± 39.9 ng/ml. Serum sLDL-R levels were significantly and positively correlated with BMI (rs = 0.252) and TG (rs = 0.408) and LDL-C (rs = 0.325) concentrations. Multiple regression analysis adjusted for age, gender, and smoking showed that BMI (ß = 0.274), TG (ß = 0.328), and LDL-C (ß = 0.224) were factors independently correlated with sLDL-R levels. CONCLUSION: Serum sLDL-R concentration may be a marker of diseases associated with TG metabolism. This is the first report to date describing the clinical relevance of sLDL-R.

Fatigue as a key factor for testing knee stability with single leg drop landing for injury prevention and return to play tests.

Objectives: Fatigue can decrease knee stability and increase the injury risk. However, fatigue is rarely being applied throughout movement analysis. The aim of this study was to investigate if the knee stability throughout SLDLs differ between cyclic and acyclic sports, before and after fatigue in general, and between the dominant and non-dominant leg of soccer players. Methods: A total of 43 active male (n = 34) and female (n = 9) athletes (age: 26.5 ± 7.2) participated in this study with a pre-post-design. Subjects performed a single leg drop landing (SLDL) from a plyobox. For each leg, the two-dimensional frontal plane projection angle (FPPA) was analyzed. After pretesting the shuttle run test was performed until exhaustion, before repeating the measurements. Results: ANOVA with repeated measures was applied and identified no significance difference for the FPPA between cyclic and acyclic sports (F = 0.98, p = 0.33), a significant difference before and after fatigue (F = 12.49, p = 0.002) and no significant difference between the dominant and non dominant leg of soccer players (F = 4.35, p = 0.26). Discussion: Fatigue seems to be able to have a significant influence on knee stability in the frontal axis. Therefore, fatigue should be included in motion analysis for injury prevention and return to play tests because during this physical state most injuries happen.

Synthetic low-density lipoprotein (sLDL) selectively delivers paclitaxel to tumor with low systemic toxicity.

Low density lipoprotein (LDL), which is a principal carrier for the delivery of cholesterol, has been used as a great candidate for the delivery of drugs to tumor based on the great requirements for cholesterol of many cancer cells. Mimicking the structure and composition of LDL, we designed a synthetic low-density lipoprotein (sLDL) to encapsulate paclitaxel-alpha linolenic acid (PALA) for tumor therapy. The PALA loaded sLDL (PALA-sLDL) and PALA-loaded microemulsion (PALA-ME, without the binding domain for LDLR) displayed uniform sizes with high drug loading efficiency (> 90%). In vitro studies demonstrated PALA-sLDL exhibited enhanced cellular uptake capacity and better cytotoxicity to LDLR over-expressed U87 MG cells as compared to PALA-ME. The uptake mechanisms of PALA-sLDL were involved in a receptor mediated endocytosis and macropinocytosis. Furthermore, the in vivo biodistribution and tumor growth inhibition studies of PALA-sLDL were investigated in xenograft U87 MG tumor-bearing mice. The results showed that PALA-sLDL exhibited higher tumor accumulation than PALA-ME and superior tumor inhibition efficiency (72.1%) compared to Taxol® (51.2%) and PALA-ME (58.8%) but with lower toxicity. These studies suggested that sLDL is potential to be used as a valuable carrier for the selective delivery of anticancer drugs to tumor with low systemic toxicity.