Nucleotide‐based drugs, such as antisense oligonucleotides (ASOs), have unique advantages in treating human diseases as they provide virtually unlimited ability to target any gene. However, their ...clinical translation faces many challenges, one of which is poor delivery to the target tissue in vivo. This problem is particularly evident in solid tumors. Here, liposomes are functionalized with a tumor‐homing and ‐penetrating peptide, iRGD, as a carrier of an ASO against androgen receptor (AR) for prostate cancer treatment. The iRGD‐liposomes exhibit a high loading efficiency of AR‐ASO, and an efficient knockdown of AR gene products is achieved in vitro, including AR splice variants. In vivo, iRGD‐liposomes significantly increase AR‐ASO accumulation in the tumor tissue and decrease AR expression relative to free ASOs in prostate tumors established as subcutaneous xenografts. Similar results are obtained with intra‐tibial xenografts modeling metastasis to bones, the predominant site of metastasis for prostate cancer. In treatment studies, iRGD‐liposomes markedly improve the AR‐ASO efficacy in suppressing the growth of both subcutaneous xenografts and intra‐tibial xenografts. The inhibitory effect on tumor growth is also significantly prolonged by the delivery of the AR‐ASO in the iRGD‐liposomes. Meanwhile, iRGD‐liposomes does not increase ASO accumulation or toxicity in healthy organs. Overall, a delivery system that can significantly increase ASO accumulation and efficacy in solid tumors is provided here. These benefits are achieved without significant side effects, providing a way to increase the antitumor efficacy of ASOs.
A peptide (iRGD)‐functionalized liposomal system is generated to improve the delivery of antisense oligonucleotides (ASOs) into solid tumors. This system increases the tumor accumulation and vascular penetration of an ASO against androgen receptor (AR) in castration‐resistant prostate cancer and bone metastases. This results in an increase in short‐ and long‐term antitumor efficacy of AR‐ASO against both primary tumors and metastasis.
Endocytic pathways provide the primary route for therapeutic and diagnostic nanoparticles (NPs) to enter cells and subcellular compartments. A better understanding of these cell entry processes will ...not only aid in nanomaterial applications but also broaden our knowledge of cell biology. Among the endocytic routes, macropinocytosis has unique characteristics for engulfing NPs and other large cargo, yet its molecular machinery and involvement in NP uptake are far less characterized relative to other pathways. In this review, we summarize the current knowledge on the macropinocytic machinery, and its involvement in NP internalization. Particularly, we differentiate ligand (specifically peptide)-functionalized and unfunctionalized NPs (bystander NPs). While most of previous research focused on ligand-functionalized NPs, we showcase here a synergistic effect between these two NP types during their cell entry through receptor-mediated macropinocytosis. The regulation of NP uptake efficiency by extracellular amino acids is also highlighted in the context of interconnections between macropinocytosis and metabolic signaling. These discussions may fuel future research interests in improving NP internalization through this pathway, and open a new avenue to study the interplay among endocytosis, metabolism and nanomedicine.
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•This review summarizes the macropinocytosis machinery and its internalization of nanoparticles, with special focus on receptor-mediated macropinocytosis.•This review describes a synergistic entry of peptide-functionalized and bystander nanoparticles into cells through receptor-mediated macropinocytosis.•This review highlights the regulation of nanoparticle uptake efficiency by extracellular amino acids.
Oxidative stress is considered a key factor contributing to the initiation and development of cardiac injury following ischaemia‒reperfusion (I/R). Arachidonate 5-lipoxygenase (ALOX5) is a ...rate-limiting enzyme for leukotriene biosynthesis. MK-886 is an inhibitor of ALOX5 that exhibits anti-inflammatory and antioxidant activities. However, the significance of MK-886 in preventing I/R-mediated cardiac injury and the underlying mechanism remain unclear. Cardiac I/R model was produced by ligation/release of the left anterior descending artery. MK-886 (20 mg/kg) was administered intraperitoneally into mice at 1 and 24 h before I/R. Our results indicated that MK-886 treatment significantly attenuated I/R-mediated cardiac contractile dysfunction and decreased the infarct area, myocyte apoptosis, and oxidative stress accompanied with reduction of Kelch-like ECH-associated protein 1 (keap1) and upregulation of nuclear factor erythroid 2-related factor 2 (NRF2). Conversely, administration of the proteasome inhibitor epoxomicin and NRF2 inhibitor ML385 greatly abrogated MK-886-mediated cardioprotection after I/R injury. Mechanistically, MK-886 enhanced the expression of the immunoproteasome subunit β5i, which interacted with keap1 and enhanced its degradation, leading to activation of the NRF2-dependent antioxidant response and improvement of mitochondrial fusion-fission balance in the I/R-treated heart. In summary, our present findings indicated that MK-886 could protect the heart against I/R injury and highlight that MK-886 may represent a promising therapeutic candidate for preventing ischaemic disease.
Atrial fibrillation (AF) is associated with inflammation and oxidative stress. Recently, we demonstrated that the chemokine‐receptor CXCR2 plays a critical role in the recruitment of ...monocytes/macrophages and the development of hypertension and cardiac remodelling. However, the role of CXCR2 in the pathogenesis of hypertensive AF remains unclear. AF was induced in Wistar‐Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) administered with the CXCR2 inhibitor SB225002. Atrial remodelling, pathological changes and electrophysiology were examined. Our results showed that the chemokine CXCL1 and its receptor CXCR2 were markedly increased in atrial tissue of SHRs compared with WKYs. The administration of SB225002 to SHRs significantly reduced the elevation of blood pressure, AF inducibility and duration, atrial remodelling, recruitment of macrophages, superoxide production and conduction abnormalities compared with vehicle treatment. The administration of SB225002 to SHRs also reversed pre‐existing AF development, atrial remodelling, inflammation and oxidative stress. These effects were associated with the inhibition of multiple signalling pathways, including TGF‐β1/Smad2/3, NF‐κB‐P65, NOX1, NOX2, Kir2.1, Kv1.5 and Cx43. In conclusion, this study provides new evidence that blocking CXCR2 prevents and reverses the development of AF in SHRs, and suggests that CXCR2 may be a potential therapeutic target for hypertensive AF.
Cardiac ischaemia/reperfusion (I/R) injury causes cardiomyocyte apoptosis and mitochondrial dysfunction. Ursolic acid (UA), as a pentacyclic triterpenoid carboxylic acid, exerts several bioactivities ...in animal models of different diseases, but the preventive role of UA in I/R-induced myocardial dysfunction remains largely unknown. Male wild-type mice were pre-administered with UA at a dosage of 80 mg/kg i.p. and then subjected to cardiac I/R injury for 24 h. Cardiac function and pathological changes were examined by echocardiography and histological staining. The protein and mRNA levels of the genes were determined using qPCR and immunoblotting analysis. Our results revealed that UA administration in mice significantly attenuated the I/R-induced decline in cardiac function, infarct size, myocyte apoptosis, and oxidative stress. Mechanistically, UA increased three immunoproteasome catalytic subunit expressions and activities, which promoted ubiquitinated PP2A degradation and activated AMPK-PGC1α signalling, leading to improved mitochondrial biosynthesis and dynamic balance. In vitro experiments confirmed that UA treatment prevented hypoxia/reperfusion (H/R)-induced cardiomyocyte apoptosis and mitochondrial dysfunction through activation of AMPK signalling. In summary, our findings identify UA as a new activator of the immunoproteasome that exerts a protective role in I/R-induced myocardial dysfunction and suggest that UA supplementation could be beneficial for the prevention of cardiac ischaemic disease.
Scope
Cardiac fibrosis is a key feature of cardiac remodeling. Recently, a protective role for resveratrol (RES) in pressure‐overload‐induced cardiac hypertrophy and contractile dysfunction has been ...demonstrated. However, the effect of RES on cardiac fibrosis and diastolic function in this model remains unclear.
Methods and results
Cardiac remodeling is induced in mice by transverse aortic constriction (TAC) for 2–4 weeks. RES is administered at dose of 5 or 50 mg kg–1 d–1 for 2 weeks. It is found that RES administration at 50 mg kg–1 d–1 significantly attenuates TAC‐induced adverse cardiac systolic and diastolic function, fibrosis, inflammation, and oxidative stress via inhibiting PTEN degradation and the downstream mediators. However, RES at 5 mg kg–1 d–1 has no significant effects. RES at 50 mg kg–1 d–1 also ameliorates pre‐established adverse cardiac function and remodeling induced by TAC. Treatment with PTEN inhibitor VO‐OHpic (10 mg kg–1 d–1) for 2 weeks abolishes RES‐mediated protective effects. Additionally, the effect of RES (100 µm) on inhibition of Ang II‐induced fibroblast proliferation and activation in vitro is verified.
Conclusions
The findings provide new evidence that RES plays a critical role in the progression of cardiac fibrosis and diastolic dysfunction, and suggest that RES may be a promising therapeutic agent for cardiac fibrosis.
Cardiac remodeling is induced in mice by transverse aortic constriction (TAC). The results showed that resveratrol administration significantly attenuated TAC‐induced cardiac dysfunction, fibrosis, inflammation, and oxidative stress via inhibiting PTEN degradation and activation of the downstream mediators. Furthermore, a PTEN inhibitor, VO‐OHpic, abolishes resveratrol‐mediated protective effects. These results suggest that resveratrol may be a promising therapeutic agent against cardiac fibrosis.
Cardiac remodeling is an important pathological process ultimately leading to heart failure. Ubiquitin carboxy-terminal hydrolase 1 (UCHL1) is a deubiquitinase that plays a critical role in ...neurodegenerative diseases and cancer. However, its role in cardiac remodeling in spontaneously hypertensive rats remains unclear. Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs) were administered the UCHL1 inhibitor LDN-57444 (20 μg/kg/day) from 2 months of age for 4 months. Blood pressure, cardiac hypertrophy, fibrosis, inflammation, and oxidative stress were evaluated by the tail-cuff system, echocardiography, and histological analysis. Gene and protein expression levels were examined by real-time PCR and immunoblotting analysis. At 6 months of age, the expression of UCHL at the mRNA and protein levels was significantly upregulated in SHRs compared with WKYs. Moreover, systolic blood pressure, cardiac performance, left ventricular (LV) hypertrophy, fibrosis, inflammation, and superoxide production were significantly increased in SHRs compared with WKYs, and these effects were markedly attenuated by LDN-57444 after 4 months of administration. These beneficial actions were possibly associated with a reduction in blood pressure and inactivation of multiple signaling pathways, including AKT, ERK1/2, STAT3, calcineurin A, TGF-β/Smad2/3, and NF-κB. In conclusion, the results indicate that UCHL1 is involved in hypertensive cardiac remodeling in SHRs, and targeting UCHL1 activity may be a novel potential therapeutic approach for the treatment of hypertensive heart diseases.
Necroptosis and apoptosis contribute to the pathogenesis of myocardial ischaemia/reperfusion (I/R) injury and subsequent heart failure. N-arachidonoylphenolamine (AM404) is a paracetamol lipid ...metabolite that has pleiotropic activity to modulate the endocannabinoid system. However, the protective role of AM404 in modulating I/R-mediated myocardial damage and the underlying mechanism remain largely unknown. A murine I/R model was generated by occlusion of the left anterior descending artery. AM404 (20 mg/kg) was injected intraperitoneally into mice at 2 and 24 h before the I/R operation. Our data revealed that AM404 administration to mice greatly ameliorated I/R-triggered impairment of myocardial performance and reduced infarct area, myocyte apoptosis, oxidative stress and inflammatory response accompanied by the reduction of receptor interacting protein kinase (RIPK)1/3- mixed lineage kinase domain-like (MLKL)-mediated necroptosis and upregulation of the immunosubunits (β2i and β5i). In contrast, administration of epoxomicin (a proteasome inhibitor) dramatically abolished AM404-dependent protection against myocardial I/R damage. Mechanistically, AM404 treatment increases β5i expression, which interacts with Pellino-1 (Peli1), an E3 ligase, to form a complex with RIPK1/3, thereby promoting their degradation, which leads to inhibition of cardiomyocyte necroptosis in the I/R heart. In conclusion, these findings demonstrate that AM404 could prevent cardiac I/R damage and may be a promising drug for the treatment of ischaemic heart disease.
Myocardial ischemia/reperfusion injury (I/RI) is closely associated with energy substrate metabolism. Fibronectin 1 (Fn1) was markedly elevated in the heart of I/R pigs and ischemic patients, but its ...role in myocardial I/RI is controversial and the precise mechanism involved remains elusive. Herein, we tested whether blockage of Fn1 with its inhibitor (fibronectin tetrapeptide, RGDS) would alleviate myocardial I/RI. Wild-type (WT) mice were administered with RGDS once 3 h before I/R operation and once at 24 or 48 h postreperfusion, and sacrificed at 24 or 72 h post-I/R, respectively. Cardiac function was evaluated by echocardiography. Myocardial infarction size, apoptosis, fibrosis, and inflammation were examined via histological staining. Uptake of glucose and fatty acids were detected by positron emission tomography (PET) and computer tomography (CT) with 18F-2-fluoro-2-deoxy-D-glucose (FDG) and 18F-fluoro-6-thia-heptadecanoic acid (FTHA), respectively. Our results showed that administration of RGDS to mice remarkably limited the I/R-induced myocardial infarct size, myocyte apoptosis, inflammation, oxidative stress, and fibrosis and improved cardiac contractile dysfunction. These protective effects were associated with upregulation of the AMP/ATP ratio and the activation of LKB1-AMPK signaling, which subsequently increased AS160-GLUT4-mediated glucose and fatty acid uptake, improved mitochondrial dynamic imbalance, and inactivated TGF-β and NF-κB signals in the I/R heart. In conclusion, the current study identified that blocking Fn1 protects against myocardial I/RI likely through activating the LKB1-AMPK-dependent signals and highlights that inhibition of Fn1 may be a novel therapeutic option for treating ischemic heart diseases.
Quaternized polybenzimidazole anion exchange membranes exhibit excellent stability, however, always suffer from poor hydroxide conductivity as compared with other polymer categories. In this work, it ...is found that polybenzimidazole anion transition state, though essential to provide grafting sites, has strong ionic interaction with the conventional quaternary ammonium cations containing grafting reagents. A novel grafting strategy is proposed to pre-remove polybenzimidazole anions by fully grafting of non-cationic ether-containing side chains, and then attaches quaternary ammonium cations to the end of pendent side chains. Further investigations with molecular dynamics simulation, TEM and SAXS indicate that by eliminating cation-anion binding, the flexible pendent quaternized cations exhibit excellent ability to aggregate into ionic clusters and transport hydroxide ions. The trimethylammonium grafting membrane shows conductivity of about 82.4 mS cm−1 at 80 °C, around 6-fold that of the conventional grafted membranes. Grafting with alkaline stable piperidinium, 93.2% conductivity retention is achieved even soaking in 2 M KOH at 60 °C for 720 h. The H2/O2 single cell shows high peak power density of about 806.1 mW cm−2 at large current density of about 2025.0 mA cm−2, which is the highest value among the polybenzimidazole membranes reported in recent years.
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•PBI anion is essential to graft but binds quaternized cation to limit conductivity.•Non-cationic graft pre-removes PBI anion and then quaternization avoids ionic bond.•Flexible cation ended side chains greatly improve ability to microphase separation.•The de-anionic PBI achieves 6-fold conductivity that of conventional grafted PBI.•Power density of H2/O2 cell (806 mW cm−2) is the highest report in PBI based AEMs.
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