Myocardial infarction (MI), which results in myocardial cell dysfunction and irreversible loss, is one of the most serious health threats today. This study was started with rats, by which the consequence of miRNA expression dysregulation to the occurrence and progression of cardiovascular diseases was explored. We first conducted miRNA sequencing on the myocardial tissues separately from myocardial infarction treatment and sham operation treatment to clarify those differently expressed miRNAs; then, our experiment of functional verification of those key miRNAs was initiated so as to dig out the molecular mechanism behind the miRNA’s regulation in myocardial infarction. And it turned out that there were 32 upregulated miRNAs and 16 downregulated miRNAs according to our comparison from the myocardial infarction model group to the sham operation group; of all those upregulated, alteration in miR-214-3p expression was the most conspicuous. Overexpression of miR-214-3p greatly alleviated myocardial infarct area and ameliorated myocardial tissue structure, even reducing myocardial fibrosis and the devastation in the tissues. On the molecular level, miR-214-3p overexpression brought down both the apoptosis rate and cleaved caspase 3 expression. Besides that, we verified that PTEN is the target gene of miR-214-3p through a dual-luciferase assay. A cotransfection of miR-214-3p and PTEN brought about an obvious elevation in the myocardial infarct area, tissue damage, and fibrosis, even in the aspect of cellular apoptosis than a mere transfection of miR-214-3p. All the results above verified miR-214-3p′s effects in protecting myocardial tissues and reducing the infarct area, and it was reasonable to assume that those functions of miR-214-3p came into effect by targeting PTEN, which was then justified by the inversion to miR-214-3p′s protection via PTEN overexpression.

As a common cardiovascular disease, acute myocardial infarction seriously affects the health and life of patients. miRNAs play an important role in acute myocardial infarction. Based on miRNA obtained from the previous sequencing, this study investigated whether miRNA (miR)-124-3p-loaded nanoparticles (NPs) affect the phenotype of the acute myocardial infarction (AMI) rat. Nano-miR-124-3p decreased the myocardial infarction area, improved the myocardial tissue structure, and increased the degree of fibrosis. Nano-miR-124-3p decreased apoptosis and the expression of cleaved caspase 3, indicating its role in protecting and repairing the myocardium. To further verify the action mechanism of miRNA, a potential target gene of miR-124-3p, PTEN was identified by STARBASE and further confirmed using double luciferase assays. Following cotransfection of nano-miR-124-3p and PTEN, the areas of tissue structure damage, myocardial infarction, and fibrosis were substantially elevated. The expression of cleaved caspase 3 and the apoptosis rate in the nano-miR-124-3p and PTEN cotransfection group was also significantly increased. Bioinformatics analysis revealed that miRNA-124-3 may regulate oxidative stress injury by targeting PTEN. Taken together, miR-124-3p could protect and repair myocardial tissues through targeting PTEN.

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Background The effect of a high-fat diet on bone mineral density is still controversial. The present study is to evaluate the relationship between a high-fat diet and bone mineral density in the American adults. Methods We performed a cross-sectional analysis of the US population aged 50 years or older based on data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018. The primary outcome measure was the femur bone mineral density by dual energy x-ray absorptiometry (DXA) of osteoporosis or osteopenia. Multivariable logistic regression analysis was used to evaluate the effect of high-fat diet on the presence of osteopenia and osteoporosis. Results The prevalence of total femur, femoral neck, trochanter and intertrochanter osteopenia or osteoporosis respectively was 22.8%, 51.3%, 22.6% and 19.4% in men and 43.5%, 66.9%, 39% and 38% in women. Multivariable logistic regression analysis after adjustment for confounders showed that a high-fat diet was significantly associated with higher odds of total femur and trochanter osteopenia or osteoporosis in men and intertrochanteric osteopenia or osteoporosis in women. However, a high-fat diet was negatively associated with the occurrence of osteopenia or osteoporosis in male femoral neck and total femur and femoral neck in female. There were no significant associations between high-fat diet and osteopenia or osteoporosis in male intertrochanteric and in female trochanter. The subgroup analyses found that compared with normal fat intake, the highest fat intake levels were only significantly and negatively associated with femoral neck osteopenia or osteoporosis in men and total femur, trochanter and intertrochanteric in women. Conclusions The effects of a high-fat diet as a separate contribution to the incidence of osteopenia or osteoporosis were biphasic with both positive and negative effects that varied by femoral sites and were not gender-related. In addition, higher levels of dietary fat intake did not increase subject's the odds of osteopenia or osteoporosis.

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