Recently, trimethylamine-N-oxide (TMAO) plasma levels have been proved to be associated with atherosclerosis development. Among the targets aimed to ameliorating atherosclerotic lesions, inducing bile acid synthesis to eliminate excess cholesterol in body is an effective way. Individual bile acid as endogenous ligands for the nuclear receptor has differential effects on regulating bile acid metabolism. It is unclear whether bile acid profiles are mechanistically linked to TMAO-induced development of atherosclerosis. Male apoE−/− mice were fed with control diet containing 0.3% TMAO for 8 weeks. Aortic lesion development and serum lipid profiles were determined. Bile acid profiles in bile, liver and serum were measured by liquid chromatographic separation and mass spectrometric detection (LC-MS). Real-time PCRs were performed to analyze mRNA expression of genes related to hepatic bile acid metabolism. The total plaque areas in the aortas strongly increased 2-fold (P < 0.001) in TMAO administration mice. The levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c) in TMAO group were also significantly increased by 25.5% (P = 0.044), 31.2% (P = 0.006), 28.3% (P = 0.032), respectively. TMAO notably changed bile acid profiles, especially in serum, the most prominent inductions were tauromuricholic acid (TMCA), deoxycholic acid (DCA) and cholic acid (CA). Mechanically, TMAO inhibited hepatic bile acid synthesis by specifically repressing the classical bile acid synthesis pathway, which might be mediated by activation of small heterodimer partner (SHP) and farnesoid X receptor (FXR). These findings suggested that TMAO accelerated aortic lesion formation in apoE−/− mice by altering bile acid profiles, further activating nuclear receptor FXR and SHP to inhibit bile acid synthesis by reducing Cyp7a1 expression.

Ethanolamine plasmalogen (pPE), a major phospholipid in neuronal membranes, is specifically reduced in postmortem brains from patients with Alzheimer's disease (AD). The purpose of the present study was to compare the effects of EPA-enriched ethanolamine plasmalogen (EPA-pPE) and EPA-enriched phosphatidylethanolamine (EPA-PE) on cognitive deficiency and illustrate the possible underlying mechanisms. SD rats were divided into four groups including the sham group injected with 0.9% saline and three amyloid-β (Aβ) infusion groups, Aβ42 group, EPA-pPE group and EPA-PE group. EPA-pPE and EPA-PE were administered by gavage (150 mg kg⁻¹ day⁻¹), respectively, once a day for 26 days. Administration of EPA-pPE exerted better effects than EPA-PE in improving Aβ-induced cognitive deficiency in a rat model of Alzheimer's disease. Further mechanical research indicated that EPA-pPE was superior to EPA-PE in regulating oxidative stress via increasing SOD activity and decreasing MDA level, as well as reducing GSK-3β and tau phosphorylation. Moreover, EPA-PE was more effective than EPA-pPE at inhibiting the protein expressions of Bax and caspase 9. The results of neuro-inflammation and inflammasome activation showed that EPA-pPE exerted more significant effects than EPA-PE in inhibiting the expressions of TNF-α and IL-1β, and decreasing NLRP3, pro-caspase 1 and caspase 1 levels. EPA-pPE alleviated Aβ-induced neurotoxicity by inhibiting oxidative stress, neuronal injury, apoptosis and neuro-inflammation, which might depend on the vinyl ether linkage at the sn-1 position.

Hydrogel is a new class of functional polymer materials with a promising potential in the biomedical field. The purpose of this article is to review recent advancements in several types of biomedical hydrogels, including conductive hydrogels, injectable hydrogels, double network hydrogels, responsive hydrogels, nanocomposite hydrogels, and sliding hydrogels. In comparison with traditional hydrogels, these advanced hydrogels exhibit significant advantages in structure, mechanical properties, and applications. The article focuses on different methods used to prepare advanced biomedical hydrogels and their diversified applications as drug delivery systems, wound dressings, biosensors, contact lenses, and tissue replacement. These advances are rapidly overcoming current limitations of hydrogels, and we anticipate that further research will lead to the development of advanced hydrogels with ubiquitous roles in biomedicine and tissue replacement and regeneration.