Mendelian randomization to evaluate the causal relationship between liver enzymes and the risk of six specific bone and joint-related diseases.

Background: Studies of liver dysfunction in relation to bone and joint-related diseases are scarce, and its causality remains unclear. Our objective was to investigate whether serum liver enzymes are causally associated with bone and joint-related diseases using Mendelian randomization (MR) designs. Methods: Genetic data on serum liver enzymes (alkaline phosphatase (ALP); alanine transaminase (ALT); gamma-glutamyl transferase (GGT)) and six common bone and joint-related diseases (rheumatoid arthritis (RA), osteoporosis, osteoarthritis (OA), ankylosing spondylitis, psoriatic arthritis, and gout) were derived from independent genome-wide association studies of European ancestry. The inverse variance-weighted (IVW) method was applied for the main causal estimate. Complementary sensitivity analyses and reverse causal analyses were utilized to confirm the robustness of the results. Results: Using the IVW method, the positive causality between ALP and the risk of osteoporosis diagnosed by bone mineral density (BMD) at different sites was indicated (femoral neck, lumbar spine, and total body BMD, odds ratio (OR) [95% CI], 0.40 [0.23-0.69], 0.35 [0.19-0.67], and 0.33 [0.22-0.51], respectively). ALP was also linked to a higher risk of RA (OR [95% CI], 6.26 [1.69-23.51]). Evidence of potential harmful effects of higher levels of ALT on the risk of hip and knee OA was acquired (OR [95% CI], 2.48 [1.39-4.41] and 3.07 [1.49-6.30], respectively). No causal relationship was observed between GGT and these bone and joint-related diseases. The study also found that BMD were all negatively linked to ALP levels (OR [95% CI] for TBMD, FN-BMD, and LS-BMD: 0.993 [0.991-0.995], 0.993 [0.988-0.998], and 0.993 [0.989, 0.998], respectively) in the reverse causal analysis. The results were replicated via sensitivity analysis in the validation process. Conclusions: Our study revealed a significant association between liver function and bone and joint-related diseases.

[Change of Bcl-2, Bax proteins and mitochondrial membrane protein on nitric oxide induced apoptosis in HL-60 cells].

To investigate the possible mechanisms of nitric oxide (NO)-induced apoptosis in leukemia cell line HL-60, HL-60 cells in vitro were incubated with sodium nitroprusside (SNP), the in situ cell apoptosis quantitatively was assayed by TdT-mediated dUTP nick end labeling (TUNEL), the cell cycle DNA and proteins expression of Bcl-2, Bax, mitochondrial membrane protein (APO2.7) were analyzed by flow cytometry. The results showed that SNP induced HL-60 cell apoptosis in a dosage- and time-dependent manner. After exposure to SNP at the concentration of 1.0 mmol/L for 48 hours, the percentage of apoptosis HL-60 was (42.2 +/- 3.5)% for subG1 and (52.5 +/- 7.6)% for TUNEL respectively, and they are significantly higher than those in control and potassium ferricyanide (PFC) groups as same concentration. During the apoptosis process, it showed a decrease of Bcl-2 protein and an increase of Bax protein and mitochondrial membrane protein in HL-60 cell, proteins of Bcl-2, Bax and mitochondrial membrane were expressed in a dosage- and time-dependent manner too. In conclusion, during the process of SNP induced apoptosis in HL-60 cell, the expression of mitochondrial membrane protein was increased, Bcl-2 and Bax proteins may be important regulators.