Blood lipid levels mediating the effects of sex hormone-binding globulin on coronary heart disease: Mendelian randomization and mediation analysis.

Observational studies indicate that serum sex hormone-binding globulin (SHBG) levels are inversely correlated with blood lipid levels and coronary heart disease (CHD) risk. Given that dyslipidemia is an established risk factor for CHD, we aim to employ Mendelian randomization (MR) in conjunction with mediation analysis to confirm the mediating role of blood lipid levels in the association between SHBG and CHD. First, we assessed the causality between serum SHBG levels and five cardiovascular diseases using univariable MR. The results revealed causality between SHBG levels and reduced risk of CHD, myocardial infarction, as well as hypertension. Specifically, the most significant reduction was observed in CHD risk, with an odds ratio of 0.73 (95% CI 0.63-0.86) for each one-standard-deviation increase in SHBG. The summary-level data of serum SHBG levels and CHD are derived from a sex-specific genome-wide association study (GWAS) conducted by UK Biobank (sample size = 368,929) and a large-scale GWAS meta-analysis (60,801 cases and 123,504 controls), respectively. Subsequently, we further investigated the mediating role of blood lipid level in the association between SHBG and CHD. Mediation analysis clarified the mediation proportions for four mediators: high cholesterol (48%), very low-density lipoprotein cholesterol (25.1%), low-density lipoprotein cholesterol (18.5%), and triglycerides (44.3%). Summary-level data for each mediator were sourced from the UK Biobank and publicly available GWAS. The above results confirm negative causality between serum SHBG levels and the risk of CHD, myocardial infarction, and hypertension, with the causal effect on reducing CHD risk largely mediated by the improvement of blood lipid profiles.

Inhibiting mir-34a-5p regulates doxorubicin-induced autophagy disorder and alleviates myocardial pyroptosis by targeting Sirt3-AMPK pathway.

Doxorubicin (DOX) is a commonly used chemotherapy drug widely applied in various cancers such as breast cancer, leukemia, and sarcomas. However, its usage is limited by cardiotoxicity. Additionally, the cardiac toxicity of DOX accumulates with dose and duration, making it imperative to identify therapeutic targets for DOX-induced cardiomyopathy (DIC). It has been reported that miRNAs are involved in the progression of DIC. Mir-34a-5p has been identified as an early diagnostic marker for DIC. While studies have shown the involvement of mir-34a-5p in DIC apoptosis, it has not been validated in animal models, nor has the potential improvement of DIC by inhibiting mir-34a-5p been confirmed. Autophagy and pyroptosis are key factors in the development of DIC and can serve as therapeutic targets for its treatment. In this study, we found that mir-34a-5p was upregulated in the heart after DOX treatment and that the inhibition of mir-34-5p reduced autophagy and pyroptosis in DIC. We also found that the inhibition of mir-34a-5p inhibited pyroptosis by regulating autophagy and reducing mitochondrial reactive oxygen species. Moreover, we identified Sirtuin3 (Sirt3) as a target gene of mir-34a-5p using a double-luciferase reporter assay. overexpression Sirt3 reduced pyroptosis by alleviating autophagy. Our research findings suggest that inhibiting mir-34a-5p has a beneficial role in alleviating autophagy and pyroptosis in DIC. This provides therapeutic prospects for treating DIC.

[Effects of bergapten on damages of osteocytes MLO-Y4 induced by TCP wear particles and its mechanism].

OBJECTIVE: To study the effects of bergapten (BP) on damages of osteocytes MLO-Y4 induced by tricalcium phosphate (TCP) wear particles and its mechanism. ;Methods: MLO-Y4 cells were treated with TCP wear particles for 48 h to establish the model of osteocytes injuries in vitro. The MLO-Y4 cells were divided into the following five groups: control group, TCP wear particles treated (0.1 mg/ml) group, bergapten (1, 5 and 20 µmol/L) treated groups. MTT assay and Calcein-AM staining were used to determine the viability of MLO-Y4 cells; Hoechst 33342 staining and the flow cytometry were applied to detect the apoptosis of MLO-Y4; real-time PCR was performed to examine the mRNA levels of dentin matrix protein1 (DMP-1), sclerostin (SOST) and fibroblast growth factor23 (FGF23); Western blot was performed to examine protein expressions of glucose-regulated protein 78 (GRP78), protein kinase R-like ER kinase (PERK) phospho-PERK (p-PERK), eukaryotic initiation factor 2α (eIF2α), phospho-eIF2α (p-eIF2α), activating transcription factor 4 (AFT4), C/EBP homologous protein (CHOP) and caspase-3 in MLO-Y4 cells. ;Results: Compared with control group, the MLO-Y4 viability and DMP-1 mRNA level in TCP group were decreased significantly (P＜0.05), while the percentage of apoptosis and mRNA levels of SOST and FGF23 were obviously increased (P＜0.05), and protein expressions of GRP78, AFT4, CHOP, p-PERK/PERK and p-eIF2α/eIF2α were up-regulated significantly in MLO-Y4 cells (P＜0.05). Compared with TCP group, the damages of MLO-Y4 and cell apoptosis in bergapten treated groups were decrease obviously (P＜0.05), the expressions of GRP78, AFT4, CHOP, p-PERK/PERK and p-eIF2α/eIF2α were down-regulated remarkably (P＜0.05). ;Conclusion: Bergapten can inhibit osteocytes damages induced by TCP wear particles, which may be related to reducing ER stress and PERK pathway activation.

Feature Learning Based Random Walk for Liver Segmentation.

Liver segmentation is a significant processing technique for computer-assisted diagnosis. This method has attracted considerable attention and achieved effective result. However, liver segmentation using computed tomography (CT) images remains a challenging task because of the low contrast between the liver and adjacent organs. This paper proposes a feature-learning-based random walk method for liver segmentation using CT images. Four texture features were extracted and then classified to determine the classification probability corresponding to the test images. Seed points on the original test image were automatically selected and further used in the random walk (RW) algorithm to achieve comparable results to previous segmentation methods.