Nano-sensitizer with self-amplified drug release and hypoxia normalization properties potentiates efficient chemoradiotherapy of pancreatic cancer.

The hypoxic nature of pancreatic cancer, one of the most lethal malignancies worldwide, significantly impedes the effectiveness of chemoradiotherapy. Although the development of oxygen carriers and hypoxic sensitizers has shown promise in overcoming tumor hypoxia. The heterogeneity of hypoxia-primarily caused by limited oxygen penetration-has posed challenges. In this study, we designed a hypoxia-responsive nano-sensitizer by co-loading tirapazamine (TPZ), KP372-1, and MK-2206 in a metronidazole-modified polymeric vesicle. This nano-sensitizer relies on efficient endogenous NAD(P)H quinone oxidoreductase 1-mediated redox cycling induced by KP372-1, continuously consuming periphery oxygen and achieving evenly distributed hypoxia. Consequently, the normalized tumor microenvironment facilitates the self-amplified release and activation of TPZ without requiring deep penetration. The activated TPZ and metronidazole further sensitize radiotherapy, significantly reducing the radiation dose needed for extensive cell damage. Additionally, the coloaded MK-2206 complements inhibition of therapeutic resistance caused by Akt activation, synergistically enhancing the hypoxic chemoradiotherapy. This successful hypoxia normalization strategy not only overcomes hypoxia resistance in pancreatic cancer but also provides a potential universal approach to sensitize hypoxic tumor chemoradiotherapy by reshaping the hypoxic distribution.

Apoptosis and autophagy of muscle cell during pork postmortem aging.

OBJECTIVE: Pork is an important source of animal protein in many countries. Subtle physiochemical changes occur during pork postmortem aging. The changes of apoptosis and autophagy in pork at 6 h to 72 h after slaughter were studied to provide evidence for pork quality. METHODS: In this article, morphological changes of postmortem pork was observed through Hematoxylin-eosin staining, apoptotic nuclei were observed by TdT-mediated dUTP nick end labeling assay, protein related to apoptosis and autophagy expressions were tested by western blot and LC3 level were expressed according to immunofluorescence assay. RESULTS: In this study, we found the occurrence of apoptosis in postmortem pork, and the process was characterized by nucleus condensation and fragmentation, formation of apoptotic bodies, increase in apoptosis-related Bax/Bcl-2 levels, and activation of caspases. Autophagy reached its peak between 24 and 48 h after slaughter, accompanied by the formation of autophagosomes on the cell membrane and expression of autophagy-related proteins beclin-1, P62, LC3-I, LC3-II, and ATG5. CONCLUSION: Obvious apoptosis was observed at 12 h and autophagy reached its peak at 48 h. The present work provides the evidence for the occurrence of apoptosis and autophagy during postmortem aging of pork. In conclusion, the apoptosis and autophagy of muscle cells discovered in this study have important implications for pork in the meat industry.

Prodrug Nanosensitizer Overcomes the Radiation Resistance of Hypoxic Tumor.

Clinical radiation therapy (RT) is often hindered by the low radiation energy absorption coefficient and the hypoxic features of tumor tissues. Among the tremendous efforts devoted to overcoming the barriers to efficient RT, the application of hypoxic radiosensitizers and cell-cycle-specific chemotherapeutics has shown great potential. However, their effectiveness is often compromised by their limited bioavailability, especially in the hypoxic region, which plays a major role in radioresistance. Herein, to simultaneously improve the delivery efficacy of both hypoxic radiosensitizer and cell-cycle-specific drug, a gambogic acid (GA) metronidazole (MN) prodrug (GM) was designed and synthesized based on GA, a naturally occurring chemotherapeutic and multiple pathway inhibitor, and MN, a typical hypoxic radiosensitizer. In combination with MN-containing block copolymers, the prodrug nanosensitizer (NS) of GM was obtained. Owing to the bioreduction of MN, the as-designed prodrug could be efficiently delivered to hypoxic cells and act on mitochondria to cause the accumulation of reactive oxygen species. The strong G2/M phase arrest caused by the prodrug NS could further sensitize treated cells to external radiation under hypoxic conditions by increasing DNA damage and delaying DNA repair. After coadministration of the NS with a well-established tissue-penetrating peptide, efficient tumor accumulation, deep tumor penetration, and highly potent chemoradiotherapy could be achieved.

Design, Synthesis and Bioactivity Evaluation of Novel Chalcone Derivatives Possessing Tryptophan Moiety with Dual Activities of Anti-Cancer and Partially Restoring the Proliferation of Normal Kidney Cells Pre-Treated with Cisplatin.

BACKGROUND: Chalcone is a broad-spectrum natural product with anti-cancer and anti-inflammatory activities. However, low potency, low selectivity, and serious side effects limit its druggability. L-Tryptophan is an essential precursor molecule of an anti-cancer active substance. Also, the indole moiety inhibits the proliferation of tumor cells by binding to colchicine sites. A decrease in kidney cell activity caused by kidney inflammation is the primary side effect of cancer therapy. OBJECTIVE: The purpose of this work was to design, synthesize, and perform bioactivity evaluation of novel chalcone derivatives possessing tryptophan moiety with dual activities of anti-cancer and partially restoring the proliferation of normal kidney cells pre-treated with cisplatin. METHODS: A series of novel chalcone derivatives possessing tryptophan moiety (5a-5g, 6a-6o) were designed, synthesized, and evaluated for anti-cancer activity against four cancer cell lines (gastric (HGC-27), colon (HCT-116), prostate (PC-3), and lung (A549)), and a human normal cell line (gastric mucosal epithelial (GES-1)). The activity of restoring the proliferation of normal kidney cells pre-treated with cisplatin was evaluated by MTT assay. Cell cycle, apoptosis, and apoptosis proteins (Bax and Bcl-2) were used to evaluate the anti-cancer mechanism of the most potent compound. Moreover, a docking study was performed to explain the high anti-cancer activity of 6n. The expressions of TNF-α, IL- 6, and MCP-1 were detected by ELISA. RESULTS: Most of the compounds exhibited high anti-cancer activity against the HGC-27 cell line and exhibited low toxicity against the normal cell line. Based on three rounds of a structure optimization, 6n was discovered as the most potent compound against HGC-27 cells with an IC50 value of 2.02 µM and an SI value of 28.47. Further studies demonstrated that 6n could induce cell cycle arrest at the G2/M phase and the apoptosis of the HGC-27 cell line by reducing the expression of Bcl-2 and improving the expression level of Bax. Molecular docking result displayed 6n bound to the colchicine site. At the same time, 6n also exhibited moderate activity of restoring the proliferation of normal kidney cells pre-treated with cisplatin by reducing the expression of inflammatory substances. CONCLUSION: Our findings collectively suggested that 6n should be further studied as a potential anti-cancer agent that could partially restore the proliferation of normal kidney cells pre-treated with cisplatin in gastric cancer patients by an anti-inflammatory pathway.

Intermittent Fasting Inhibits High-Fat Diet-Induced Atherosclerosis by Ameliorating Hypercholesterolemia and Reducing Monocyte Chemoattraction.

Atherosclerosis is a major pathology for cardiovascular diseases (CVDs). Clinically, the intermittent fasting (IF) has been observed to reduce the risk of CVDs. However, the effect of IF on the development of atherosclerosis has not been fully elucidated. Herein, we determined the protection of IF against high-fat diet-induced atherosclerosis in pro-atherogenic low-density lipoprotein receptor deficient (LDLR-/-) mice and the potentially involved mechanisms. The LDLR-/- mice were scheduled intermittent fasting cycles of 3-day HFD feeding ad libitum and 1 day fasting, while the mice in the control group were continuously fed HFD. The treatment was lasted for 7 weeks (∼12 cycles) or 14 weeks (∼24 cycles). Associated with the reduced total HFD intake, IF substantially reduced lesions in the en face aorta and aortic root sinus. It also increased plaque stability by increasing the smooth muscle cell (SMC)/collagen content and fibrotic cap thickness while reducing macrophage accumulation and necrotic core areas. Mechanistically, IF reduced serum total and LDL cholesterol levels by inhibiting cholesterol synthesis in the liver. Meanwhile, HFD-induced hepatic lipid accumulation was attenuated by IF. Interestingly, circulating Ly6Chigh monocytes but not T cells and serum c-c motif chemokine ligand 2 levels were significantly reduced by IF. Functionally, adhesion of monocytes to the aortic endothelium was decreased by IF via inhibiting VCAM-1 and ICAM-1 expression. Taken together, our study indicates that IF reduces atherosclerosis in LDLR-/- mice by reducing monocyte chemoattraction/adhesion and ameliorating hypercholesterolemia and suggests its potential application for atherosclerosis treatment.

ERK1/2 inhibition reduces vascular calcification by activating miR-126-3p-DKK1/LRP6 pathway.

Rationale: Vascular microcalcification increases the risk of rupture of vulnerable atherosclerotic lesions. Inhibition of ERK1/2 reduces atherosclerosis in animal models while its role in vascular calcification and the underlying mechanisms remains incompletely understood. Methods: Levels of activated ERK1/2, DKK1, LRP6 and BMP2 in human calcific aortic valves were determined. ApoE deficient mice received ERK1/2 inhibitor (U0126) treatment, followed by determination of atherosclerosis, calcification and miR-126-3p production. C57BL/6J mice were used to determine the effect of U0126 on Vitamin D3 (VD3)-induced medial arterial calcification. HUVECs, HAECs and HASMCs were used to determine the effects of ERK1/2 inhibitor or siRNA on SMC calcification and the involved mechanisms. Results: We observed the calcification in human aortic valves was positively correlated to ERK1/2 activity. At cellular and animal levels, U0126 reduced intimal calcification in atherosclerotic lesions of high-fat diet-fed apoE deficient mice, medial arterial calcification in VD3-treated C57BL/6J mice, and calcification in cultured SMCs and arterial rings. The reduction of calcification was attributed to ERK1/2 inhibition-reduced expression of ALP, BMP2 and RUNX2 by activating DKK1 and LRP6 expression, and consequently inactivating both canonical and non-canonical Wnt signaling pathways in SMCs. Furthermore, we determined ERK1/2 inhibition activated miR-126-3p production by facilitating its maturation through activation of AMPKα-mediated p53 phosphorylation, and the activated miR-126-3p from ECs and SMCs played a key role in anti-vascular calcification actions of ERK1/2 inhibition. Conclusions: Our study demonstrates that activation of miR-126-3p production in ECs/SMCs and interactions between ECs and SMCs play an important role in reduction of vascular calcification by ERK1/2 inhibition.

Food with calorie restriction reduces the development of atherosclerosis in apoE-deficient mice.

Calorie restriction (CR) ameliorates various diseases including cardiovascular disease. However, its protection and underlying mechanisms against atherosclerosis remain un-fully elucidated. In this study, we fed apoE deficient (apoE-/-) mice in Control group a high-fat diet (HFD, 21% fat plus 0.5% cholesterol) or in CR group a CR diet (CRD, 2% fat plus 0.5% cholesterol, ∼40% calorie restriction and same levels of cholesterol, vitamins, minerals and amino acids as in HFD). After 16 weeks feeding, compared with HFD, CRD substantially reduced atherosclerosis in mice. CRD increased SMC and collagen content but reduced macrophage content, necrotic core and vascular calcification in lesion areas. Mechanistically, CRD attenuated bodyweight gain, improved lipid profiles but had little effect on macrophage lipid metabolism. CRD also inhibited expression of inflammatory molecules in lesions. Taken together, our study demonstrates CRD effectively reduces atherosclerosis in apoE-/- mice, suggesting it as a potent and reproducible therapy for atherosclerosis management.

Photoenhanced gene transfection by a curcumin loaded CS-g-PZLL micelle.

The codelivery of drug and gene is a promising method for cancer treatment. In our previous works, we prepared a cationic micelles based on chitosan and poly-(N-3-carbobenzyloxylysine) (CS-g-PZLL), but transfection ratio of CS-g-PZLL to Hela cell was low. Herein, to improve the transfection efficiency of CS-g-PZLL, curcumin was loaded in the CS-g-PZLL micelle. After irradiation, the obtained curcumin loaded micelle showed a better transfection, and the p53 protein expression in Hela cells was higher. The apoptosis assay showed that the complex could induce a more significant apoptosis to Hela cells than that of curcumin or p53 used alone, and the curcumin loaded micelle inducing apoptosis was best after irradiation. Therefore, CS-g-PZLL is a safe and effective carrier for the codelivery of drug/gene, and curcumin could be used as a photosensitizer to induce a photoenhanced gene transfection, which should be encouraged in improving transfection and tumor therapy.

Synthesis, novel luminescence properties, and surface-enhanced Raman scattering of Au/Y2O3:Eu(3+) composite nanotubes.

Y(OH)3:Eu(3+) nanotubes were synthesized by a facile hydrothermal method first, and then Au particles were grown on the surface of Y2O3:Eu(3+) nanotubes by combining the vacuum extraction method and the annealing process. The composite nanotubes were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The effects of the Au content on the photoluminescence properties of the Au/Y2O3:Eu(3+) composite nanotubes were investigated in detail. In the excitation spectra of Au/Y2O3:Eu(3+) monitored at 614 nm, the (7)F0→(5)H3 transition from Eu(3+) increased with increasing Au content, while the other sharp lines originating from Eu(3+) f-f electron transitions almost vanished. In the emission spectra, the spectral configurations of Eu(3+) in Au/Y2O3:Eu(3+) composite nanotubes varied with the excitation wavelengths. When the excitation wavelength was 256 nm, the (5)D4→(7)F0, (5)D7→(7)F0, (5)G2→(7)F0, (5)L6→(7)F0, (5)D0→(7)F0, (5)D0→(7)F1, (5)D0→(7)F2, (5)D0→(7)F3, and (5)D0→(7)F4 transitions from Eu(3+) ions in Au/Y2O3:Eu(3+) were observed. When the excitation wavelength was 378 nm, the plasmon resonance peak from Au nanoparticles was observed. In addition, 4-ATP was chosen as the model molecule to examine the performance of the Au/Y2O3:Eu(3+) composite nanotubes as SERS substrates. The relative intensities of the SERS spectra enhanced with the increase of Au(+) : Ln(3+) ratio.

Controlled synthesis and novel luminescence properties of string SrWO4:Eu³âº nanobeans.

One-dimensional SrWO4:Eu(3+) nanostructures were prepared by a hydrothermal method. The structures and morphologies of the nanocrystals were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, and scanning electron microscopy. The results indicated that the phase compositions, morphologies and sizes and luminescence properties of SrWO4:Eu(3+) are related to the initial reactant content and reaction time, and lower initial reactant content is beneficial for the formation of the string SrWO4:Eu(3+) nanobeans. The photoluminescence properties of SrWO4:Eu(3+) were investigated in detail. In the emission spectra of SrWO4:Eu(3+), the (5)D0→(7)F1 is dominant when the excitation wavelength is 295 nm, while the (5)D0→(7)F2 is dominant when the excitation wavelengths are in the range of 363-537 nm. Obviously, the string SrWO4:Eu(3+) nanobeans have multiple luminescence centers or emitting states. The excitation spectra of SrWO4:Eu(3+) contain several sharp peaks attributed to f-f transitions of Eu(3+) ions and a broad excitation band assigned to the overlap of WO4(3-) absorption and charge transfer transition between Eu(3+) and O(2-). The intensity ratio of the broad excitation band to the sharp excitation peaks changed with the emission wavelength as well as the Eu(3+) content. In addition, Eu(3+) ions occupy higher symmetry sites in SrWO4:Eu(3+) nanocrystals with increasing the particle size of nanocrystals. The effect of Tb(3+) as well as Gd(3+) ions on the photoluminescence of SrWO4:Eu(3+) was also investigated.