Synthesis and evaluation of folate-mediated targeting and poly (ß-amino ester)-mediated pH-responsive delivery system of riccardin D based on the O-carboxymethylated chitosan micelles.

This study aimed to combine the active targeting function of folate (FA) receptor-mediated endocytosis with the pH-responsive drug delivery of poly (ethylene glycol)-grafted-poly (-amino ester) copolymers (PEG-PAE) in cancer targeting therapy. Herein, O-carboxymethylated chitosan (OCMC) was grafted with hydrophobic deoxycholic acid (DOCA). Further, PEG-PAE and FA-conjugated DOCA modified OCMC were synthesized to develop the potential cancer-targeted carrier (PEG-PAE-DOMC-FA), for which the structure was investigated by 1H NMR and FTIR. Then riccardin D (RD) was successfully loaded for tumor-targeted drug delivery. The particle size, zeta potential, encapsulating efficiencies, and loading content profiles of PEG-PAE-DOMC-FA/RD showed a strong dependence on the environmental pH values. The cumulative release of PEG-PAE-DOMC-FA/RD at pH 5.0 (90.63 %) was higher than pH 7.4 (51.12 %), which also indicated the pH sensitivity. Moreover, a lower IC50 and higher coumarin-6 uptake were found because of the folate-receptor-mediated endocytosis. In pharmacokinetic study, PEG-PAE-DOMC-FA/RD significantly improved the mean retention time (MRT) and AUC(0-∞) from 7.89 h and 36.1 mg/L·h of control group to 10.03 h and 123.8 mg/L·h. In the xenograft mice model, stronger antitumor efficacy and lower toxicity were confirmed. In conclusion, the multi-functional micelles could be considered as a promising vehicle for delivering hydrophobic drugs to tumors.

Porcupine inhibitor CGX1321 alleviates heart failure with preserved ejection fraction in mice by blocking WNT signaling.

Heart failure with preserved ejection fraction (HFpEF) is highly prevalent, and lacks effective treatment. The aberration of WNT pathway underlies many pathological processes including cardiac fibrosis and hypertrophy, while porcupine is an acyltransferase essential for the secretion of WNT ligands. In this study we investigated the role of WNT signaling pathway in HFpEF as well as whether blocking WNT signaling by a novel porcupine inhibitor CGX1321 alleviated HFpEF. We established two experimental HFpEF mouse models, namely the UNX/DOCA model and high fat diet/L-NAME ("two-hit") model. The UNX/DOCA and "two-hit" mice were treated with CGX1321 (3 mg·kg-1·d-1) for 4 and 10 weeks, respectively. We showed that CGX1321 treatment significantly alleviated cardiac hypertrophy and fibrosis, thereby improving cardiac diastolic function and exercise performance in both models. Furthermore, both canonical and non-canonical WNT signaling pathways were activated, and most WNT proteins, especially WNT3a and WNT5a, were upregulated during the development of HEpEF in mice. CGX1321 treatment inhibited the secretion of WNT ligands and repressed both canonical and non-canonical WNT pathways, evidenced by the reduced phosphorylation of c-Jun and the nuclear translocation of ß-catenin and NFATc3. In an in vitro HFpEF model, MCM and ISO-treated cardiomyocytes, knockdown of porcupine by siRNA leads to a similar inhibitory effect on WNT pathways, cardiomyocyte hypertrophy and cardiac fibroblast activation as CGX1321 did, whereas supplementation of WNT3a and WNT5a reversed the anti-hypertrophy and anti-fibrosis effect of CGX1321. We conclude that WNT signaling activation plays an essential role in the pathogenesis of HFpEF, and porcupine inhibitor CGX1321 exerts a therapeutic effect on HFpEF in mice by attenuating cardiac hypertrophy, alleviating cardiac fibrosis and improving cardiac diastolic function.

DOCA-Salt Hypertension: an Update.

Hypertension is a multifaceted disease that is involved in ∼40% of cardiovascular mortalities and is the result of both genetic and environmental factors. Because of its complexity, hypertension has been studied by using various models and approaches, each of which tends to focus on individual organs or tissues to isolate the most critical and treatable causes of hypertension and the related damage to end-organs. Animal models of hypertension have ranged from Goldblatt's kidney clip models in which the origin of the disease is clearly renal to animals that spontaneously develop hypertension either through targeted genetic manipulations, such as the TGR(mRen2)27, or selective breeding resulting in more enigmatic origins, as exemplified by the spontaneously hypertensive rat (SHR). These two genetically derived models simulate the less-common human primary hypertension in which research has been able to define a Mendelian linkage. Several models are more neurogenic or endocrine in nature and illustrate that crosstalk between the nervous system and hormones can cause a significant rise in blood pressure (BP). This review will examine one of these neurogenic models of hypertension, i.e., the deoxycorticosterone acetate (DOCA), reduced renal mass, and high-salt diet (DOCA-salt) rodent model, one of the most common experimental models used today. Although the DOCA-salt model is mainly believed to be neurogenic and has been shown to impact the central and peripheral nervous systems, it also significantly involves many other body organs.

High-Fiber Diet and Acetate Supplementation Change the Gut Microbiota and Prevent the Development of Hypertension and Heart Failure in Hypertensive Mice.

BACKGROUND: Dietary intake of fruit and vegetables is associated with lower incidence of hypertension, but the mechanisms involved have not been elucidated. Here, we evaluated the effect of a high-fiber diet and supplementation with the short-chain fatty acid acetate on the gut microbiota and the prevention of cardiovascular disease. METHODS: Gut microbiome, cardiorenal structure/function, and blood pressure were examined in sham and mineralocorticoid excess-treated mice with a control diet, high-fiber diet, or acetate supplementation. We also determined the renal and cardiac transcriptome of mice treated with the different diets. RESULTS: We found that high consumption of fiber modified the gut microbiota populations and increased the abundance of acetate-producing bacteria independently of mineralocorticoid excess. Both fiber and acetate decreased gut dysbiosis, measured by the ratio of Firmicutes to Bacteroidetes, and increased the prevalence of Bacteroides acidifaciens. Compared with mineralocorticoid-excess mice fed a control diet, both high-fiber diet and acetate supplementation significantly reduced systolic and diastolic blood pressures, cardiac fibrosis, and left ventricular hypertrophy. Acetate had similar effects and markedly reduced renal fibrosis. Transcriptome analyses showed that the protective effects of high fiber and acetate were accompanied by the downregulation of cardiac and renal Egr1, a master cardiovascular regulator involved in cardiac hypertrophy, cardiorenal fibrosis, and inflammation. We also observed the upregulation of a network of genes involved in circadian rhythm in both tissues and downregulation of the renin-angiotensin system in the kidney and mitogen-activated protein kinase signaling in the heart. CONCLUSIONS: A diet high in fiber led to changes in the gut microbiota that played a protective role in the development of cardiovascular disease. The favorable effects of fiber may be explained by the generation and distribution of one of the main metabolites of the gut microbiota, the short-chain fatty acid acetate. Acetate effected several molecular changes associated with improved cardiovascular health and function.