Design, synthesis and evaluation of wound healing activity for ß-sitosterols derivatives as potent Na+/K+-ATPase inhibitors.

ß-Sitosterols, is a common steroid that can be identified in a variety of plants and their efficacy in promoting wound healing has been demonstrated. Na+/K+-ATPase, more than a pump, its signal transduction function for involvement in cell growth regulation attracts widespread concern. The Na+/K+-ATPase/Src receptor complex can serve as a receptor involved in multiple signaling pathways including promoting wound healing pathways. To finding potent accelerating wound healing small molecular, we choose the high inhibitory activity of Na+/K+-ATPase and non-cardiotoxic natural compound, ß-sitosterol as the substrate. A series of ß-sitosterol derivatives were designed, synthesized and evaluated as potential Na+/K+-ATPase inhibitors. Among them, compounds 31, 47, 49, showed improved inhibitory activity on Na+/K+-ATPase, with IC50 value of 3.0 µM, 3.4 µM, 2.2 µM, which are more potent than ß-sitosterol with IC50 7.6 µM. Especially, compound 49 can induce cell proliferation, migration and soluble collagen production in L929 fibroblasts. Compared to model, compound 49 can accelerate wound healing in SD rats. Further studies indicated that 49 can activate the sarcoma (Src), uptake the protein kinase B (Akt), extracellular signal-regulated kinase (ERK) proteins expression in a concentration dependent manner. Finally, binding mode of compound 49 with Na+/K+-ATPase was studied, which provides insights into the determinants of potency and selectivity. These results proved ß-stitosterol derivative 49 can serve as an effective inhibitor of Na+/K+-ATPase and potential candidate for accelerating wound healing agents.

Targeted degradation of anaplastic lymphoma kinase by gold nanoparticle-based multi-headed proteolysis targeting chimeras.

Anaplastic lymphoma kinase (ALK) is a major target in treating non-small-cell lung cancer, and several ALK inhibitors have been developed to antagonize its kinase activity. However, patients treated with inhibitors ultimately develop drug resistance. Therefore, therapies with new mechanisms of action are needed. Proteolysis targeting chimeras (PROTACs) are molecules that comprise a ligand for binding a protein of interest (POI), a connecting linker and a ligand for recruiting E3 ligase, and cause degradation of the target POI. Here, the first multi-headed PROTAC, as a proof of concept, is developed as a gold nanoparticle (GNP)-based drug delivery system for delivering PROTACs to target ALK. Pegylated GNPs loaded with both ceritinib and pomalidomide molecules, termed Cer/Pom-PEG@GNPs, showed good stability in several media. The GNP conjugates potently decreased the levels of ALK fusion proteins in a dose- and time-dependent manner, and specifically inhibited the proliferation of NCI-H2228 cells. In comparison with small molecule PROTACs, the new multi-headed PROTAC promoted the formation of coacervates of POIs/multi-headed PROTAC/E3 ubiquitin ligases, and POI and E3 ubiquitin ligase interacted through multidirectional ligands and a flexible linker, thereby avoiding the need for complicated structure optimization of PROTACs. In conclusion, Cer/Pom-PEG@GNPs can degrade intracellular ALK fusion proteins with minor off-target toxicity and can be applied in patients resistant to ALK inhibitors. As a nano-based drug carrier, Cer/Pom-PEG@GNPs have the potential to enable prolonged circulation and specifically distribute drugs to tumor regions in vivo; thus, further investigation is warranted.

Effects of remote ischemic preconditioning on contrast induced nephropathy after percutaneous coronary intervention in patients with acute coronary syndrome.

OBJECTIVE: The aim of this study was to explore the clinical effects of remote ischemic preconditioning (RIPC) on contrast-induced nephropathy after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). PATIENTS AND METHODS: The study was a single-center, prospective, randomized, controlled study. A total of 161 patients with ACS and the rate of estimate glomerular filtration (eGFR) 15 to 70 mL/min/1.73 m2 undergoing PCI were randomly assigned to RIPC group (induced by 4 times of 5-minute inflations of a blood pressure cuff to 200 mmHg around the upper arm, followed by 5-min intervals of reperfusion at 1 hour before PCI therapy) or control group (an uninflated cuff around the arm). Successful completion of the PCI eventually included 107 cases of patients, including 50 cases in the RIPC group and 57 cases in the control group. The level of serum creatinine (Scr), CystatinC (CysC), blood neutrophil gelatinase-associated lipocalin (NGAL), eGFR were measured in all patients at 6 AM before the day of PCI, and 4-hour NGAL, 24-hour CysC, 72-hour Scr, and eGFR after PCI in the 2 groups. The incidence of major adverse events in the kidney (including the incidence of CIN, the need for dialysis, or renal replacement therapy after using contrast agent) and the composite endpoint of cardiovascular events were recorded at 6 months after PCI. RESULTS: There were no statistically significant differences in baseline indicators between the 2 groups. Scr, CysC, and blood NGAL levels and the incidence of CIN in patients with RIPC group were significantly lower than those form the control group after PCI (P < .05), but there were no significant differences between the average value of eGFR and occurrence of Major cardiovascular events in the postoperative 6 months (P > .05). CONCLUSIONS: RIPC can reduce PCI-related CIN and protect renal function in patients with ACS. The benefits of these patients by RIPC may be related to the reduction of the NGAL and CysC.

[Protective effects of curcumin on vascular endothelial injuries induced by radiation].

OBJECTIVE: To study the effects of curcumin on vascular endothelial injuries induced by radiation and the mechanism. METHODS: Human umbilical vein endothelial cells (HUVEC) were isolated, cultured and divided into the control group and 4 groups exposed to 3-ray at the doses of 2, 4, 6 and 8 Gy. Cellular morphological and ultrastructural changes were examined under light microscopy and electron microscopy respectively. Flow cytometry was used to detect the cellular apoptosis, necrosis and intracellular reactive oxygen species(ROS) generation. The contents of Lactate dehydrogenase (LDH) and malondialdehyde (MDA) in the cultures were measured before and after irradiation. RESULTS: The results of cellular morphological and ultrastructural ex-aminations shown that the typical apoptotic changes appeared after irradiation. The rates of apoptosis and necrosis in groups pretreated with curcumin were significantly lower than those in other groups (P<0.05). LDH and MDA in the irradiation groups were significantly higher than those in curcumin pretreatment groups (P<0.05). The ROS generation in radiation groups significantly increased with the radiation doses, as compared with the groups pre-treated with curcumin (P<0.05). CONCLUSION: Irradiation induced the apoptosis and necrosis of HUVEC, and increased significantly the intracellular LDH and MDA levels in a dose-dependent. Curcumin had the protective effects on HUVEC from the apoptosis and necrosis induced by radiation.