Preparation of the new peptide drug ACTY116-loaded in situ forming implants and evaluation of its efficacy in pulmonary arterial hypertension and right ventricular hypertrophy induced by SU5416/hypoxia in mice.

There is a lack of effective therapeutic drugs for pulmonary arterial hypertension. Previous studies have demonstrated the positive cardiovascular system protective effects of the new peptide ACTY116. However, its stability in ordinary aqueous solution injections is poor and its half-life in the body is short, which has hindered the development of preparations. This study aimed to prepare in situ forming implants (ISFIs) of the peptide ACTY116 and investigate its impact on pulmonary arterial hypertension. We prepared ISFIs using NMP/TA as a solvent and PLGA as a polymer. These ISFIs exhibited low viscosity, low toxicity and sustained release properties. In a mouse model of pulmonary hypertension induced by SU5416/hypoxia, both ISFIs and ACTY116 peptides effectively reduced pulmonary hypertension, cardiac hypertrophy and pulmonary blood vessel wall thickness. In conclusion, this study highlights the potential of ACTY116 as a treatment for pulmonary arterial hypertension and suggests that incorporating it into an in-situ gel implant could be a promising option.

Phillyrin improves myocardial remodeling in salt-sensitive hypertensive mice by reducing endothelin1 signaling.

OBJECTIVES: Prolonged exposure to chronic hypertension places the heart under excessive strain, resulting in myocardial remodeling. Phillyrin, derived from the natural plant Forsythia suspensa, has been found to possess cardioprotective properties. The objective of this study is to investigate the role and mechanism of phillyrin in hypertension-induced myocardial remodeling in mice. METHODS: We constructed a mouse model of salt-sensitive hypertension. The mice were treated with varying doses of phillyrin, and their blood pressure, cardiac function, cardiac hypertrophy, fibrosis, inflammation, and other conditions were assessed. KEY FINDINGS: Our research findings demonstrated that phillyrin has the potential to lower blood pressure, enhance cardiac function, and mitigate cardiac hypertrophy, fibrosis, and inflammatory responses in deoxycorticosterone acetate-salt hypertension mice. In hypertensive mice, there was an elevated expression of endothelin1 (ET-1) in heart tissue, which can be reduced by phillyrin. Additionally, phillyrin effectively reduced the hypertrophy of H9c2 cells induced by ET-1 stimulation. CONCLUSIONS: Our research highlights the therapeutic capabilities of phillyrin in the treatment of myocardial remodeling through the reduction of ET-1 signaling. These results contribute to the advancement of novel applications for phillyrin and establish a solid conceptual basis for future investigations in this area.

Salidroside attenuates myocardial remodeling in DOCA-salt-induced mice by inhibiting the endothelin 1 and PI3K/AKT/NFκB signaling pathways.

Myocardial remodeling, which occurs in the final stage of cardiovascular diseases such as hypertension, can ultimately result in heart failure. However, the pathogenesis of myocardial remodeling remains incompletely understood, and there is currently a lack of safe and effective treatment options. Salidroside, which is extracted from the plant Rhodiola rosea, shows remarkable antioxidant and anti-inflammatory characteristics. The purpose of this investigation was to examine the cardioprotective effect of salidroside on myocardial remodeling, and clarify the associated mechanism. Salidroside effectively attenuated cardiac dysfunction, myocardial hypertrophy, myocardial fibrosis, and cardiac inflammation, as well as renal injury and renal fibrosis in an animal model of deoxycortone acetate (DOCA)-salt-induced myocardial remodeling. The cardioprotective effect of salidroside was mediated by inhibiting the endothelin 1 and PI3K/AKT/NFκB signaling pathways. Salidroside was shown to inhibit the expression of endothelin1 in the hearts of mice treated with DOCA-salt. Additionally, it could prevent cardiomyocyte hypertrophy induced by endothelin-1 stimulation. Furthermore, Salidroside could effectively inhibit the excessive activation of the PI3K/AKT/NFκB pathway, which was caused by DOCA-salt treatment in mouse hearts and endothelin 1 stimulation in cardiomyocytes. Our study suggests that salidroside can be used as a therapeutic agent for the treatment of myocardial remodeling.

Phillyrin attenuates norepinephrine-induced cardiac hypertrophy and inflammatory response by suppressing p38/ERK1/2 MAPK and AKT/NF-kappaB pathways.

Phillyrin, a well-known natural compound from the dried fruits of Forsythia suspensa (Thunb.) Vahl., has shown anti-inflammatory, antioxidant and anti-virus activities as well as renal protective effects on diabetic nephropathy. In this study, we investigated whether phillyrin attenuated cardiac hypertrophy induced by catecholamine in vivo and in vitro, and explored the underlying mechanisms. Cardiac hypertrophy was induced in C57BL/6 mice by subcutaneous injection of norepinephrine (NE, a key catecholamine), and in rat cardiomyoblasts (H9c2) by stimulation with NE in vitro. Our results showed that administration of phillyrin (100 mg/kg, i.p. for 15 days) significantly improved cardiac function, histopathological changes, cardiac hypertrophy and decreased the upregulated hypertrophic markers (ANP, BNP, and ß-MHC). Moreover, treatment with phillyrin obviously reduced the infiltration of the CD68 positive macrophages and the mRNA expression of proinflammatory genes (IL-1ß, IL-6, and TNF-α) in left ventricular tissue. In addition, treatment with phillyrin markedly inhibited the phosphorylation of p38 MAPK, ERK1/2, AKT, and NF-κB p65 in heart tissues. Furthermore, in NE-treated H9c2 cells, pretreatment with phillyrin clearly attenuated cardiomyocyte hypertrophy, reduced ROS production and inhibited the phosphorylation of p38 MAPK, ERK1/2, AKT, and NF-κB p65 in vitro. Collectively, our results demonstrate that phillyrin effectively alleviates NE-induced cardiac hypertrophy and inflammatory response by suppressing p38 MAPK/ERK1/2 and AKT/NF-κB signaling pathways.

Selective and sensitive detection of lysozyme based on plasmon resonance light-scattering of hydrolyzed peptidoglycan stabilized-gold nanoparticles.

The simple, economic, rapid, and sensitive detection of lysozyme has an important significance for disease diagnosis since it is a potential biomarker. In this work, a new detection strategy for lysozyme was developed based on the change of the plasmon resonance light scattering (PRLS) signal of peptidoglycan stabilized gold nanoparticles (PGN-AuNPs). Peptidoglycan (PGN) was employed as a stabilizer to prepare PGN-AuNPs which have the properties of a uniform particle size, good stability, and a specific biological function. Due to the specific cleavage of lysozyme to PGN, a very simple specific and sensitive detection method for lysozyme was developed based on the PRLS signal of PGN-AuNPs after mixing with lysozyme for 1.5 h. The enhanced PRLS signals (ΔIPRLS, at 560 nm) increased linearly with increasing lysozyme in the range 5 nM to 1600 nM with the detection limit down to 2.32 nM (ΔIPRLS = 41.6397 + 0.5332c, R = 0.9961). When the PGN-AuNP based method was applied to assay lysozyme in authentic human serum samples, the recovery efficiency was 106.76-119.32% with the relative standard deviations in the range of 0.14-3.11%, showing good feasibility. The PGN-AuNP based method for lysozyme assay developed here is simple, rapid, selective, and sensitive, which is expected to provide a feasible new method for the diagnosis or prognosis of lysozyme-related diseases in a clinical setting.