Membrane Proteomics of Impaired Energetics and Cytoskeletal Disorganization in Elderly Diet-Induced Diabetic Mice

TMT-based quantitative proteomic analysis of hepatic tissue reveals the effects of dietary cyanidin-3-diglucoside-5-glucoside-rich extract on alleviating D-galactose-induced aging in mice

Cyanidin-3-diglucoside-5-glucoside (CY3D5G) derivatives as major pigments in red cabbage exhibit in vitro antioxidant effects. This study evaluated the effects of CY3D5G-rich extract on oxidative stress in D-galactose-induced accelerated aging. Thirty male C57BL/6 J mice were divided into three groups: a normal control group and two D-galactose-injected groups orally administered with or without CY3D5G-rich extract (700 μmol/kg body weight). Dietary supplementation of CY3D5G-rich extract for 6 weeks increased superoxide dismutase activity, glutathione peroxidase activity, and total antioxidant capacity while suppressed malondialdehyde content in serum (p < 0.05) and tissues. Hepatic proteome analysis revealed that 243 proteins were significantly modulated by experimental treatment (p < 0.05). CY3D5G-rich extract treatment suppressed proteins involved in electron transport chain and up-regulated proteins that play important roles in glycolysis, tricarboxylic acid cycle, and actin cytoskeleton. These changes in above metabolic pathways may contribute to reducing the production and release of ROS and attenuating oxidative damage in aged mice. SIGNIFICANCE: Anthocyanins are the most abundant dietary flavonoids with potential health benefits. The proteomic analysis of mice liver in this study revealed the effect of cyanidin-3-diglucoside-5-glucoside (CY3D5G) consumption in D-galactose-induced accelerated aging. In total, 2054 protein groups were quantified in all samples without any missing value, and 243 protein groups were identified with statistical significance (p < 0.05). Bioinformatics analysis suggested that electron transport chain, glycolysis, tricarboxylic acid cycle, and actin cytoskeleton were closely correlated with CY3D5G treatment. These findings provide useful information to understand the anti-aging effect of anthocyanin, and the results of which could promote the use of anthocyanins in food and pharmaceutical industries.

Diabetes induces differences in the F-actin spatial organization of striated muscles

Studies have shown the cytoskeleton disorganization produced by diabetes and quantified F-actin fluorescence in the striated muscles of diabetic animals. However, at present, there are no studies that have quantified F-actin spatial organization (F-actin-SO). Through our research, we analyzed the effect of diabetes on F-actin-SO in the cardiac and skeletal muscles of a mouse model. The muscle samples were labeled with phalloidin-rhodamine and analyzed with confocal microscopy. The analysis was done in two dimensions using four approaches: quantitation of (a) phalloidin-occupied areas; (b) number of F-actin-unoccupied areas per muscular fiber; (c) F-actin filament discontinuity; and (d) costamere periodicity. Our results showed that both the cardiac and skeletal muscles of the control mice had more phalloidin-occupied areas than the diabetic mice. The skeletal muscles had a significantly higher number of F-actin-unoccupied areas per muscular fiber and more F-actin discontinuities. Additionally, using western blot analyses, we showed that those differences were not due to α-actin protein expression. Finally, we considered the importance of these findings in dysfunctional contraction, disassembly in cell-cell communication, conduction of muscle impulse, and changes in cell nanomechanics. Our results quantitatively demonstrated that diabetes severely affects F-actin-SO in striated muscles.

iTRAQ and PRM-based quantitative proteomics in early recurrent spontaneous abortion: biomarkers discovery

Background

Early recurrent spontaneous abortion (ERSA) is a common condition in pregnant women. To prevent ERSA is necessary to look for abortion indicators, such as hormones and proteins, in an early stage.

Methods

Thirty patients with ERSA were enrolled in the case group. In the control group, we recruited 30 healthy women without a history of miscarriage undergoing voluntary pregnancy termination. The differentially expressed proteins in the serum were identified between the two groups using PRM and iTRAQ.

Results

Seventy-eight differentially expressed proteins were identified. Using GO functional annotation and KEGG pathway analysis, we detected that the most significant changes occurred in the pathway of Fc gamma R-mediated phagocytosis. Meanwhile, using PRM, we identified three proteins that were closely related to abortion, B4DTF1 (highly similar to PSG1), P11464 (PSG1), and B4DF70 (highly similar to Prdx-2). The levels of B4DTF1 and P11464 were down-regulated, while the level of B4DF70 was up-regulated.

Conclusions

CD45, PSG1, and Prdx-2, were significantly dysregulated in the samples of ERSA and could become important biomarkers for the prediction and diagnosis of ERSA. Larger‑scale studies are required to confirm the diagnostic value of these biomarkers.

Cardiomyocyte-specific deletion of GSK-3β leads to cardiac dysfunction in a diet induced obesity model

BACKGROUND AND RATIONALE

Obesity, an independent risk factor for the development of myocardial diseases is a growing healthcare problem worldwide. It's well established that GSK-3β is critical to cardiac pathophysiology. However, the role cardiomyocyte (CM) GSK-3β in diet-induced cardiac dysfunction is unknown.

METHODS

CM-specific GSK-3β knockout (CM-GSK-3β-KO) and littermate controls (WT) mice were fed either a control diet (CD) or high-fat diet (HFD) for 55weeks. Cardiac function was assessed by transthoracic echocardiography.

RESULTS

At baseline, body weights and cardiac function were comparable between the WT and CM-GSK-3β-KOs. However, HFD-fed CM-GSK-3β-KO mice developed severe cardiac dysfunction. Consistently, both heart weight/tibia length and lung weight/tibia length were significantly elevated in the HFD-fed CM-GSK-3β-KO mice. The impaired cardiac function and adverse ventricular remodeling in the CM-GSK-3β-KOs were independent of body weight or the lean/fat mass composition as HFD-fed CM-GSK-3β-KO and controls demonstrated comparable body weight and body masses. At the molecular level, on a CD, CM-GSK-3α compensated for the loss of CM-GSK-3β, as evident by significantly reduced GSK-3αs21 phosphorylation (activation) resulting in a preserved canonical β-catenin ubiquitination pathway and cardiac function. However, this protective compensatory mechanism is lost with HFD, leading to excessive accumulation of β-catenin in HFD-fed CM-GSK-3β-KO hearts, resulting in adverse ventricular remodeling and cardiac dysfunction.

CONCLUSION

In summary, these results suggest that cardiac GSK-3β is crucial to protect against obesity-induced adverse ventricular remodeling and cardiac dysfunction.