Dietary Selenium Deficiency Facilitated Reduced Stomatin and Phosphatidylserine Externalization, Increasing Erythrocyte Osmotic Fragility in Mice.

Selenium (Se) is an essential trace element that maintains normal physiological functions in organisms. Since the discovery of glutathione peroxidase (GSH-PX), public interest in selenoproteins has gradually increased. Based on previous studies, dietary Se maintains erythrocyte homeostasis through selenoprotein-induced mediation of redox reactions. Furthermore, both the surface phosphatidylserine (PS) and intramembrane stomatin contents can be used as indicators of erythrocyte osmotic fragility. This study focused on the mechanism by which dietary Se deficiency increases erythrocyte osmotic fragility. We fed Se-deficient grain to mice for 8 weeks to establish a Se deficiency model in mice. We measured Se levels in the blood as well as the activities of antioxidant enzymes associated with selenoproteins in a Se-deficient environment. We used Western blotting, routine blood analysis, and other methods to detect red blood cell oxidative stress levels, membrane stomatin levels, and PS externalization. Fresh blood was collected to test erythrocyte osmotic fragility. The results showed that antioxidant enzyme activity was affected by dietary Se deficiency. Oxidative stress increased lipid peroxidation and the ROS content in the blood of the mice. Under such conditions, decreased PS exposure and stomatin content in the erythrocyte membrane eventually affected the structure of the erythrocyte membrane and increased erythrocyte osmotic fragility.

Zinc Deficiency Promoted Fibrosis via ROS and TIMP/MMPs in the Myocardium of Mice.

Zinc (Zn) is an important trace element in the body that has antioxidant effects. It has been proven that Zn deficiency can cause oxidative stress. The purpose of the present study was to clarify the effect and mechanism of Zn deficiency on myocardial fibrosis. Mice were fed with different Zn levels dietary for 9 weeks: Zn-normal group (ZnN, 34 mg Zn/kg), Zn-deficient group (ZnD, 2 mg Zn/kg), and Zn-adequate group (ZnA, 100 mg Zn/kg). We found that the Zn-deficient diet reduced the Zn concentration in myocardial tissue. Moreover, the TUNEL results demonstrated that cardiomyocytes in the ZnD group died in large numbers. Furthermore, ROS levels were significantly increased, and metallothionein (MT) expression levels decreased in the ZnD group. The results of Sirius Red staining indicated an increase in collagen in the ZnD group. Moreover, the ELISA results showed that collagen I, III, and IV and fibronectin (FN) were increased. In addition, the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) was detected by RT-qPCR. The results showed that the expression of TIMP-1 in the ZnD group was increased, while MMPs were decreased. Immunohistochemical results showed an increase in the content of α-smooth muscle actin (α-SMA), while H&E staining showed an increase in interstitial width and a decrease in the number of cardiac cells. All data suggest that Zn deficiency enhances the oxidative stress response of myocardial tissue and eventually triggers myocardial fibrosis.

[Expression of MIER3 in colorectal cancer and bioinformatic analysis of MIER3- interacting proteins].

OBJECTIVE: To explore role of MIER3 gene in the development and progression of human colorectal carcinoma (CRC) and analyze the proteins that interact with MIER3 using bioinformatic techniques. METHODS: MIER3 mRNA and protein expressions were detected in 8 CRC biopsy samples and paired adjacent tissues using real-time PCR and Western blotting. A recombinant eukaryotic expression vector pcDNA3-MIER3 was constructed and its effect on the proliferation and invasion of CRC cells were tested using CCK8 assay and Transwell migration assay. Bioinformatic methods were used to predict and analyze MIER3-interacting proteins. RESULTS: MIER3 was obviously down-regulated in the 8 CRC tissues as compared with the paired adjacent tissues. In human CRC cell line DLD1, MIER3 overexpression induced by transfection of the cells with pcDNA3-MIER3 significantly inhibited the cell proliferation and suppressed cell invasiveness in vitro. Bioinformatics analyses indicated that NAT9 was a potential MIER3-interacting protein and MIER3 was probably associated with tumor susceptibility. CONCLUSION: MIER3, which is obviously down-regulated in CRC tissues, is closely associated with the proliferation and invasion of CRC, and NAT9 protein is a probable MIER3-interacting protein.