Expression Changes of NMDA and AMPA Receptor Subunits in the Hippocampus in rats with Diabetes Induced by Streptozotocin Coupled with Memory Impairment

Neurochemical Research - Cognitive impairment in diabetes (CID) is a severe chronic complication of diabetes mellitus (DM). It has been hypothesized that diabetes can lead to cognitive dysfunction...     

MUC-1 aptamer targeted superparamagnetic iron oxide nanoparticles for magnetic resonance imaging of pancreatic cancer in vivo and in vitro experiment

This study aims to explore the ability of magnetic resonance imaging (MRI) in mucin 1 (MUC1) modified superparamagnetic iron oxide nanoparticle (SPION) targeting human pancreatic cancer (PC). The MUC1 target-directed probe was prepared through MUC1 conjugated to SPION using the chemical method to assess its physiochemical characteristics, including hydration diameter, surface charge, and magnetic resonance signal. The cytotoxicity of MUC1-USPION was verified by MTS assay. BxPC-3 was cultured with MUC1-USPION and SPION in different concentrations. The combined condition of the targeted probes and cells were observed through Prussian blue staining. The nude mice model of pancreatic cancer was established to investigate the application of the probe. MRI was performed to determine the intensity of the signal of the transplanted tumor, while immunohistochemistry and Western blot analysis were performed to detect the expression of MUC1 after taking the transplanted tumor specimen. The particle size of the prepared molecular probe was 63.5 ± 3.2 nm, and the surface charge was 10.2 mV. Furthermore, the probe solution could significantly reduce the MRI at T₂, and the magnetic resonance transverse relaxation rate (ΔR²) has a linear relationship with the concentration of iron in the solution. The cell viability of MUC1-USPION in different concentrations revealed no statistical difference, according to the MTS assay. In vitro, the MRI demonstrated decreased T2WI signal intensity in both groups, especially the targeting group. In vivo, MUC1 could selectively accumulate in the nude mice model, and significantly reduce the T₂ signal strength. In subsequent experiments, the expression of MUC1 was high in pancreatic cancer tissues, but low in normal pancreatic tissues, as determined by immunohistochemistry and Western blot analysis. The prepared samples can be combined with pancreatic cancer tissue specificity by in vivo imaging, providing reliable early in vivo imaging data for disease diagnosis.     

氧化甾醇结合蛋白相关蛋白家族的研究进展

膜脂是细胞膜的主要组分, 也是参与信号转导的重要信号分子。不同脂质分子在细胞膜上的不均等分布需要特殊类型的通道蛋白和运输蛋白来实现。氧化甾醇结合蛋白相关蛋白(ORPs)是一类非常保守的蛋白分子, 能够对磷脂酰肌醇和固醇等脂类分子进行识别并转运, 参与细胞中的许多生理过程, 包括信号转导、囊泡运输、脂类代谢和非囊泡运输等...     

Mir-484 contributes to diminished ovarian reserve by regulating granulosa cell function via YAP1-mediated mitochondrial function and apoptosis

Women with diminished ovarian reserve (DOR) have reduced fertility, but the underlying regulation of ovarian function remains unknown. Although differential microRNA (miRNA) expression has been described in several ovarian disorders, little is known about the role of miRNAs in the pathogenesis of DOR. In this study, we investigated the expression levels of miR-484 in granulosa cells (GCs) derived from human follicular fluid, and explored their correlation with female ovarian reserve function as well as clinical outcomes of assisted reproduction technology (ART). Additionally, we investigated the effects of miR-484 on the biological functions of GC cell lines in vitro. We found that miR-484 was highly expressed in GCs from DOR patients and was correlated with decreasing AMH levels and AFC, as well as increasing FSH levels, but not with LH, progesterone, or estradiol. Additionally, miR-484 was negatively related to the number of retrieved oocytes and the ratio of high-quality embryos. Moreover, we found that miR-484 repressed the proliferation of GCs and induced apoptosis, which can in part be attributed to mitochondrial dysfunction. Conversely, silencing miR-484 had the opposite effect. Multiple approaches, including bioinformatic analysis, RNA-seq, qPCR, immunofluorescence, western blotting and luciferase reporter assays, identified YAP1 as a direct target of miR-484 in GCs. Additionally, reintroduction of YAP1 rescued the effects of miR-484 in GCs. The present study indicates that miR-484 can directly target the mRNA of YAP1, induce mitochondrial dysfunction, and consequently reduce the viability and promote the apoptosis of granulosa cells, which contributes to the pathogenesis of DOR.     

Activation of 5'-AMP-activated kinase is mediated through c-Src and phosphoinositide 3-kinase activity during hypoxia-reoxygenation of bovine aortic endothelial cells. Role of peroxynitrite

AMP-activated kinase (AMPK) is a fuel-sensing enzyme present in most mammalian tissue. In response to a decrease in the energy state of a cell AMPK is phosphorylated and activated by still poorly characterized upstream events. Exposure of bovine aortic endothelial cells (BAEC) to chemically synthesized ONOO- acutely and significantly increased phosphorylation of c-Src, PDK1, AMPK, and its downstream target, acetyl-CoA carboxylase (ACC), without affecting cellular AMP. This novel pathway for AMPK activation was confirmed by the use of pharmacological inhibitors and dominant-negative mutants. Exposure of BAEC to hypoxia-reoxygenation (H/R) caused a biphasic increase in AMPK and ACC phosphorylation, which was prevented by adenoviral overexpression of superoxide dismutase (SOD) or inhibition of nitric-oxide synthase (NOS) implicating a role of ONOO- formed during H/R. Furthermore, dominant-negative mutants of c-Src or kinase-defective PDK1 also blocked H/R-induced AMPK activation indicating that, as with addition of exogenous ONOO-, both c-Src and PI 3-kinase are upstream of AMPK. Moreover, H/R, like ONOO-, significantly increased co-immunoprecipitation of AMPK with c-Src, suggesting that ONOO- favors physical association of AMPK with upstream kinases. Taken together, our results indicate a novel pathway by which H/R via ONOO- activates AMPK in a c-Src-mediated, PI 3-kinase-dependent manner, and suggest that ONOO--induced activation of AMPK might thereby regulate metabolic enzymes, such as ACC.