Dexamethasone-Loaded Lipid Calcium Phosphate Nanoparticles Treat Experimental Colitis by Regulating Macrophage Polarization in Inflammatory Sites.

Background: The M1/M2 polarization of intestinal macrophages exerts an essential function in the pathogenesis of ulcerative colitis (UC), which can be adjusted to alleviate the UC symptoms. Purpose: A kind of pH-sensitive lipid calcium phosphate core-shell nanoparticles (NPs), co-loading with dexamethasone (Dex) and its water-soluble salts, dexamethasone sodium phosphate (Dsp), was constructed to comprehensively regulate macrophages in different states towards the M2 phenotype to promote anti-inflammatory effects. Methods: Dex and Dsp were loaded in the outer lipid shell and inner lipid calcium phosphate (Cap) core of the LdCaPd NPs, respectively. Then, the morphology of NPs and methods for determining drug concentration were investigated, followed by in vitro protein adsorption, stability, and release tests. Cell experiments evaluated the cytotoxicity, cellular uptake, and macrophage polarization induction ability of NPs. The in vivo distribution and anti-inflammatory effect of NPs were evaluated through a 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced BALB/c mice ulcerative colitis model. Results: The LdCaPd NPs showed a particle size of about 200 nm and achieved considerable loading amounts of Dex and Dsp. The in vitro and in vivo studies revealed that in the acidic UC microenvironment, the cationic lipid shell of LdCaPd underwent protonated dissociation to release Dex first for creating a microenvironment conducive to M2 polarization. Then, the exposed CaP core was further engulfed by M1 macrophages to release Dsp to restrict the pro-inflammatory cytokines production by inhibiting the activation and function of the nuclear factor kappa-B (NF-κB) through activating the GC receptor and the NF kappa B inhibitor α (I-κBα), respectively, ultimately reversing the M1 polarization to promote the anti-inflammatory therapy. Conclusion: The LdCaPd NPs accomplished the sequential release of Dex and Dsp to the UC site and the inflammatory M1 macrophages at this site, promoting the regulation of macrophage polarization to accelerate the remission of UC symptoms.

Efficient assembly of nanopore reads via highly accurate and intact error correction.

Long nanopore reads are advantageous in de novo genome assembly. However, nanopore reads usually have broad error distribution and high-error-rate subsequences. Existing error correction tools cannot correct nanopore reads efficiently and effectively. Most methods trim high-error-rate subsequences during error correction, which reduces both the length of the reads and contiguity of the final assembly. Here, we develop an error correction, and de novo assembly tool designed to overcome complex errors in nanopore reads. We propose an adaptive read selection and two-step progressive method to quickly correct nanopore reads to high accuracy. We introduce a two-stage assembler to utilize the full length of nanopore reads. Our tool achieves superior performance in both error correction and de novo assembling nanopore reads. It requires only 8122 hours to assemble a 35X coverage human genome and achieves a 2.47-fold improvement in NG50. Furthermore, our assembly of the human WERI cell line shows an NG50 of 22 Mbp. The high-quality assembly of nanopore reads can significantly reduce false positives in structure variation detection.

DNA N6-Methyladenosine modification role in transmitted variations from genomic DNA to RNA in Herrania umbratica.

BACKGROUND: DNA methylation is an important epigenetic modification. Recently the developed single-molecule real-time (SMRT) sequencing technology provided an efficient way to detect DNA N6-methyladenine (6mA) modification that played an important role in epigenetic and positively regulated gene expression. In addition, the gene expression was also regulated by genetic variation. However, the relationship between DNA 6mA modification and variation is still unknown. RESULTS: We collected the SMRT long-reads DNA, Illumina short reads DNA and RNA datasets from the young leaves of Herrania umbratica, and used them to detect 35,654 6mA modification sites, 829,894 DNA variations and 60,672 RNA variations respectively, among which, there are 303 DNA variations and 19 RNA variations with 6mA modification, and 57,468 transmitted genetic variations from DNA to RNA. The results illustrated that the genes with 6mA modification were significant disadvantage to mutate than those genes without modification (p-value< 4.9e-08). And result from the linear regression model showed the 6mA densities of genes were associated with the transmitted variations type 0/1 to 1/1 (p-value < 0.001). CONCLUSIONS: The variations of DNA and RNA in genes with 6mA modification were significant less than those in unmodified genes. Furthermore, the variations in 6mA modified genes were easily transmitted from DNA to RNA, especially the transmitted variation from DNA heterozygote to RNA homozygote.

Anti-inflammatory, analgesic and antioxidant activities of 3,4-oxo-isopropylidene-shikimic acid.

Context 3,4-Oxo-isopropylidene-shikimic acid (ISA) is an analog of shikimic acid (SA). SA is extracted from the dry fruit of Illicium verum Hook. f. (Magnoliaceae), which has been used for treating stomachaches, skin inflammation and rheumatic pain. Objective To investigate the anti-inflammatory, analgesic and antioxidant activities of ISA. Materials and methods Analgesic and anti-inflammatory activities of ISA were evaluated using writhing, hot plate, xylene-induced ear oedema, carrageenan-induced paw oedema and cotton pellets-induced granuloma test, meanwhile the prostaglandin E2 (PGE2) and malondialdehyde (MDA) levels were assessed in the oedema paw tissue. ISA (60, 120 and 240 mg/kg in mice model and 50, 120 and 200 mg/kg in rat model) was administered orally, 30 min before induction of inflammation/pain. Additionally, ISA was administered for 12 d in rats from the day of cotton pellet implantation. The active oxygen species scavenging potencies of ISA (10(-3)-10(-5) M) were evaluated by the electron spin resonance spin-trapping technique. Results ISA caused a reduction of inflammation induced by xylene (18.1-31.4%), carrageenan (7.8-51.0%) and cotton pellets (11.4-24.0%). Furthermore, ISA decreased the production of PGE2 and MDA in the rat paw tissue by 1.0-15.6% and 6.3-27.6%, respectively. ISA also reduced pain induced by acetic acid (15.6-48.9%) and hot plate (10.5-28.5%). Finally, ISA exhibited moderate antioxidant activity by scavenging the superoxide radical and hydroxyl radical with IC50 values of 0.214 and 0.450 µg/mL, respectively. Discussion and conclusion Our findings confirmed the anti-inflammatory, analgesic and antioxidant activities of ISA.

Histone deacetylase inhibitor reverses multidrug resistance by attenuating the nucleophosmin level through PI3K/Akt pathway in breast cancer.

The development of multidrug resistance (MDR) is the major obstacle in the chemotherapy of breast cancer, and it restricts the application of antitumor drugs in the clinic. Therefore it is urgent to search for ways to reverse MDR and restore sensitivity to chemotherapeutics in breast carcinoma. Currently, histone deacetylase inhibitors (HDACIs) offer a promising strategy for tumor therapy as the effective anticancer drugs. Based on the potential resistant target of nucleophosmin (NPM), the purpose of this study was to explore the reversal effect of a new synthetic histone deacetylase inhibitor, FA17, on MDR in methotrexate-resistant breast cancer cells (MCF-7/MTX) and xenograft tumors. It was shown that the abnormal expression of NPM induced MDR and inhibited downstream mitochondrial apoptotic pathway by activating PI3K/Akt signaling pathway in MCF-7/MTX cells. The reversal effect and molecular mechanism of FA17 were investigated both in vitro and in vivo. We found that FA17 could significantly reverse resistance and sensitize MCF-7/MTX cells to methotrexate. FA17 obviously enhanced resistant cell apoptosis, inhibited expressions of NPM and efflux transporters. Additionally, FA17 could reverse MDR via inactivating PI3K/Akt pathway and accelerating mitochondrial apoptotic pathway both in MCF-7/MTX cells and in xenograft tumors. Taken together, the novel histone deacetylase inhibitor could effectively reverse drug resistance due to suppressing the activity of NPM and drug efflux pumps by PI3K/Akt and mitochondrial apoptotic pathway. The above not only indicated the potential applied value of FA17 in reversing MDR and enhancing the sensitivity of chemotherapy, but also confirmed the role of NPM in the development of MDR in breast cancer.

Establishment of paclitaxel-resistant breast cancer cell line and nude mice models, and underlying multidrug resistance mechanisms in vitro and in vivo.

BACKGROUND: Breast cancer is a common malignant tumor which affects health of women and multidrug resistance (MDR) is one of the main factors leading to failure of chemotherapy. This study was conducted to establish paclitaxel-resistant breast cancer cell line and nude mice models to explore underlying mechanisms of MDR. METHODS: The breast cancer drug-sensitive cell line MCF-7 (MCF-7/S) was exposed in stepwise escalating paclitaxel (TAX) to induce a resistant cell line MCF-7/TAX. Cell sensitivity to drugs and growth curves were measured by MTT assay. Changes of cell morphology and ultrastructure were examined by optical and electron microscopy. The cell cycle distribution was determined by flow cytometry. Furthermore, expression of proteins related to breast cancer occurrence and MDR was tested by immunocytochemistry. In Vivo, nude mice were injected with MCF-7/S and MCF-7/TAX cells and weights and tumor sizes were observed after paclitaxel treatment. In addition, proteins involved breast cancer and MDR were detected by immunohistochemistry. RESULTS: Compared to MCF-7/S, MCF-7/TAX cells had a higher resistance to paclitaxel, cross-resistance and prolonged doubling time. Moreover, MCF-7/TAX showed obvious alterations of ultrastructure. Estrogen receptor (ER) expression was low in drug resistant cells and tumors while expression of human epidermal growth factor receptor 2 (HER2) and Ki-67 was up-regulated. P-glycoprotein (P-gp), lung resistance-related protein (LRP) and glutathione-S-transferase-π (GST-π) involved in the MDR phenotype of resistant cells and tumors were all overexpressed. CONCLUSION: The underlying MDR mechanism of breast cancer may involve increased expression of P-gp, LRP and GST-π.

Protective effects of 3,4-oxo-isopropylidene-shikimic acid on experimental colitis induced by trinitrobenzenesulfonic acid in rats.

BACKGROUND: 3,4-Oxo-isopropylidene-shikimic acid (ISA) is a derivative of shikimic acid (SA). SA is extracted from Illicium verum Hook.fil., which has been used in traditional Chinese medicine and used for treating vomiting, stomach aches, insomnia, skin inflammation, and rheumatic pain. AIMS: To investigate the effects and the protective mechanism of 3,4-oxo-isopropylidene-shikimic acid on experimental colitis model induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) in rats. METHODS: Colitis in rats was induced by colonic administration with TNBS. ISA (50, 100, and 200 mg/kg) was administered for 12 days to experimental colitis rats. The inflammatory degree was assessed by macroscopic damage score, colon weight/length ratios (mg/cm), and myeloperoxidase (MPO) activity. Malondialdehyde (MDA), glutathione (GSH), and nitric oxide (NO) levels, and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), inducible nitric oxide synthase (iNOS) activities were measured with biochemical methods. RESULTS: ISA significantly ameliorated macroscopic damage, reduced colon weight/length ratios and the activity of MPO, depressed MDA and NO levels and iNOS activity, and enhanced GSH level, and GSH-Px and SOD activities in the colon tissues of experimental colitis in a dose-dependent manner. Moreover, the effect of ISA (200 mg/kg) was as effective as sulfasalazine (500 mg/kg). CONCLUSIONS: The findings of this study demonstrate the protective effect of ISA on experimental colitis, probably due to an antioxidant action.

[Absorption and transportation characteristics of scutellarin and scutellarein across Caco-2 monolayer model].

OBJECTIVE: To investigate the absorption and transepithelial transport characteristics of scutellarin and scutellarein in the human colonic adenocarcinoma cell (Caco-2) monolayer model. The influence factors on these two compounds' absorption were investigated, such as buffer solution, duration of culture, and inhibitors of multidrug resistance-associated protein 2 (MRP(2)), breast cancer drug resistance protein (BCRP) and P-glycoprotein (P-gp). METHODS: By using Caco-2 monolayer as an intestinal epithelial cell model, the transport process was studied from apical (AP) side to basolateral (BL) side or from BL to AP. The two compounds were determined by high-performance liquid chromatography coupled with diode-array-detector detection. Transport parameters and apparent permeability coeffients (P(app)) were calculated. RESULTS: The P(app) values of scutellarin and scutellarein were different in two buffer solutions, respectively. In phosphate buffered saline, scutellarin had no absorption from AP to BL, while its P(app) value was 0.74×10(-6) to 1.58×10(-6) cm/s from BL to AP. The P(app) values of scutellarein were 4.33×10(-6) to 6.79×10(-6) cm/s and 1.32×10(-6) to 2.56×10(-6) cm/s from AP to BL and from BL to AP, respectively. The P(app) value gradually decreased with time. The absorption of scutellarein was better than that of scutellarin. The scutellarin absorption was improved by verapamil, MK-571 and reserpine. The scutellarein absorption was improved by verapamil whereas its excretion was improved by MK-571. CONCLUSION: Absorption of scutellarin is difficult in Caco-2 monolayer cells, which contributes to its low bioavailability. Scutellarein absorption is better than scutellarin absorption. Scutellarein transepithelial transport is passive diffusion. The inhibitor of P-gp can improve scutellarin and scutellarein transportation. The inhibitors of MRP(2) and BCRP can promote transportation of scutellarin. The inhibitor of MRP(2) can promote efflux of scutellarein. The multidrug resistance-associated protein may be the second reason for low bioavailability of scutellarin.