Ultrasonic washing as an abiotic elicitor to induce the accumulation of phenolics of fresh-cut red cabbages: Effects on storage quality and microbial safety.

Ultrasonic washing has been proved to be an abiotic elicitor to induce the accumulation of phenolics in some fruit and vegetables. However, the feasibility of ultrasonic washing on the accumulation of phenolics in fresh-cut red cabbages has not yet been reported. Therefore, the effects of ultrasonic washing on the phenolics and related phenolic metabolism enzymes of fresh-cut red cabbages, as well as quality and microbial safety during cold storage, were investigated. Firstly, the single-factor tests were used to optimize the ultrasonic processing parameters, including frequency mode, frequency amplitude, power density, frequency cycle time, and ultrasonic washing. Then the activities of the enzymes related to phenolic metabolisms after optimal ultrasound treatment were investigated, including phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD). Additionally, the quality and microbial safety of fresh-cut red cabbages stored at 4°C under the optimal ultrasound treatment were evaluated. The results showed that the content of soluble phenolics (SPs) in fresh-cut red cabbages increased significantly during storage under the optimal conditions (28 ± 2 kHz, 60 W/L, 400 ms, and 20 min) compared with the control (P < 0.05). The PAL activity was activated and the PPO and POD activities were inhibited after ultrasonic washing, which contributed to the increase in the content of SPs. Meanwhile, the storage quality and microbial safety of fresh-cut red cabbages were improved. Ultrasonic washing reduced the weight loss and respiration rate and improved the color and texture characteristics. Additionally, the fresh-cut red cabbages after ultrasonic washing showed more retention of ascorbic acid (AA), total soluble proteins (TSPs), total soluble sugars (TSSs), and total soluble solids (SSs) compared with the control. Finally, ultrasonic washing effectively inhibited the growth of bacteria, molds and yeasts, which is beneficial to the extension of the shelf-life of fresh-cut red cabbages. Therefore, ultrasonic washing can be used as a tool to increase the content of SPs in fresh-cut red cabbages while retaining quality attributes and microbial safety.

Geniposide attenuates postischemic long-term potentiation via GluN2A.

N-Methyl-D-aspartate receptor (NMDAR)-induced antioxidation is a significant cause of neuronal injury after ischemic stroke. In a previous work, we verified the neuroprotective roles of geniposide during tMCAO in vivo. However, it remains unknown whether geniposide ameliorates injury to hippocampal neurons during Ischemic Long Term Potentiation (iLTP) induction in vitro. After induction of cells oxygen-glucose deprivation or hydrogen peroxide, the protection of geniposide evaluated by MTT assay and electrophysiological tests. In this study, we suggested neuronal cell apoptosis was attenuated by geniposide. Furthermore, field excitatory postsynaptic potentials (fEPSCs) following postischemic LTP were assessed by electrophysiological tests. Finally, we determined that medium and high doses of geniposide attenuated oxidative stress insult and improved iLTP. Importantly, these effects were abolished by cotreatment with geniposide and the GluN2A antagonist NVP. In contrast, the GluN2B inhibitor ifenprodil failed to have an effect. In conclusion, we suggest for the first time that treatment with geniposide can attenuate postischemic LTP induction in a concentration-dependent manner. We infer that GluN2A-containing NMDARs are involved in the neuroprotection induced by geniposide treatment in ischemia.

A scalable and reproducible preparation for the antitumor protein TLC, a human-derived telomerase inhibitor.

Telomerase, which is overexpressed in approximately 90% of liver cancer cells, is an ideal target for anti-liver cancer therapy. LPTS, a putative liver tumor suppressor, is the only human-derived protein that can bind telomerase directly and inhibit the extension of telomere activity. Our previous studies demonstrated that TAT-LPTS-LC (TLC), a recombinant protein fused by the C-terminal 133-328 fragment of LPTS and TAT peptides, could be delivered into cells to inhibit telomerase-positive hepatoma cell growth in vitro and in vivo with very low toxicity. In the present study, E. coli strains which expressed TLC in abundance were screened and cultured in a laboratory bioreactor. A reproducible protein separation process was built, and this process was suitable for industrial amplification. The yields of TLC protein were up to 184 mg in one batch with a purity of approximately 95%. The purified TLC protein had a similar inhibitory effect on telomerase activity in vitro compared with those purified by Ni-affinity chromatography. Furthermore, TLC protein could be delivered into the cell nucleus to increase the doubling time of the cell and suppress cell growth in telomerase-positive liver cancer cell lines. Cell growth inhibition was negatively correlated with telomere length, suggesting that TLC is a highly targeted telomerase-telomere anticancer agent. These results will contribute to future preclinical studies of the TLC protein.

The immunoenhancement effects of sea buckthorn pulp oil in cyclophosphamide-induced immunosuppressed mice.

In this study, the immunomodulatory effect of sea buckthorn (SBT) pulp oil was elucidated in immunosuppressed Balb/c mice induced by cyclophosphamide (CTX). The results showed that SBT pulp oil could reverse the decreasing trend of body weight, thymus/spleen index and hematological parameters induced by CTX. Compared with immunosuppressive mice induced by CTX, SBT pulp oil could enhance NK cytotoxicity, macrophage phagocytosis, and T lymphocyte proliferation, and regulate the proportion of T cell subsets in mesenteric lymph nodes (MLN), and promote the production of secretory immunoglobulin A (sIgA), IFN-γ, IL-2, IL-4, IL-12 and TNF-α in the intestines. In addition, SBT pulp oil can promote the production of short fatty acids (SCFAs), increase the diversity of gut microbiota, improve the composition of intestinal flora, increase the abundance of Alistipes, Bacteroides, Anaerotruncus, Lactobacillus, ASF356, and Roseburia, while decreasing the abundance of Mucispirillum, Anaeroplasma, Pelagibacterium, Brevundimonas, Ochrobactrum, Acinetobacter, Ruminiclostridium, Blautia, Ruminiclostridium, Oscillibacter, and Faecalibaculum. This study shows that SBT pulp oil can regulate the diversity and composition of intestinal microflora in CTX-induced immunosuppressive Balb/c mice, thus enhancing the intestinal mucosa and systemic immune response. The results can provide a basis for understanding the function of SBT pulp oil and its application as a new probiotic and immunomodulator.

Discovery of a natural fluorescent probe targeting the Plasmodium falciparum cysteine protease falcipain-2.

The Plasmodium falciparum cysteine protease falcipain-2 (FP-2) is an attractive antimalarial target. Here, we discovered that the natural compound NP1024 is a nonpeptidic inhibitor of FP-2 with an IC50 value of 0.44 µmol L-1. The most exciting finding is that both in vitro and in vivo, NP1024 directly targets FP-2 in malaria parasite-infected erythrocytes as a natural fluorescent probe, thereby paving the way for an integration of malaria diagnosis and treatment.

Constitutively expressed MHC class Ib molecules regulate macrophage M2b polarization and sepsis severity in irradiated mice.

Macrophages can change their physiology in response to microenvironmental signals. This differentiation into classically activated M1 or alternatively activated M2 macrophages is known as polarization. In this study, we isolated bone marrow-derived macrophages from ß2m-deficient (deficient in both MHC class Ia and Ib) and Kb Db -deficient (deficient only in MHC class Ia) mice and found that ß2m-deficient macrophages showed a significantly lower M2b polarization efficiency. In addition, the absence of constitutive MHC class Ib expression decreased the stability of the Notch-1 intracellular domain. Finally, we found that ß2m-deficient mice exposed to irradiation showed reduced bacterial translocation and sepsis severity. Overall, our study demonstrates that MHC class Ib molecules are essential for M2b macrophage polarization and suggests that MHC class Ib molecules play an important role during infection-induced innate immunity.

Colon cancer-associated transcript-1 enhances glucose metabolism and colon cancer cell activity in a high-glucose environment in vitro and in vivo.

BACKGROUND: Our study aims to investigate the effect of colon cancer-associated transcript-1 (CCAT-1) on colon cancer cells' activity and metabolism under different glucose environments in vitro and in vivo. METHODS: The levels of proliferation, migration, glucose, lactic acid, glucose metabolism-related enzymes, apoptosis genes, epithelial-mesenchymal transition (EMT) marker proteins, and PI3K/Akt/C-MYC pathway in CCAT-1-silenced SW620 cells cultured with different glucose levels were tested. Twenty BALB/C nude mice with hyperglycemia or normal blood sugar were transplanted with CCAT-1-silenced SW620 cells, blood glucose levels, lactic acid, insulin, and volume of transplanted tumor cells, the expression of EMT marker proteins, and PI3K/Akt/C-MYC pathway was detected. RESULTS: The levels of proliferation, migration, glucose, lactic acid, LDH-A, PKM2, and HK2 decreased, apoptosis increased in SW620 cells cultured with low glucose or silenced CCAT-1 (P<0.05); levels of E-cadherin and ZO-1 significantly increased, and levels of N-cadherin, vimentin, and p-Akt decreased in CCAT-1-silenced SW620 cells cultured with high glucose (P<0.05). Hyperglycemic nude mice transplanted with CCAT-1-silenced colon cancer cells showed decreased tumor volume, blood glucose, lactic acid, insulin, P-AKT, and P-C-MYC than EV group (P<0.05). CONCLUSIONS: CCAT-1 can enhance glucose metabolism and proliferation and migration of colon cancer cells by upregulating the expression of glycolysis enzymes, inhibiting apoptosis, activating the Akt/C-MYC pathway, and promoting EMT expression.

MHC class II peptides induce CD8+CD44+Ly49+ regulatory T cells in C57BL/6 mice.

CD8+ regulatory T cells (Tregs) play an important role in regulating peripheral immune tolerance. However, difficulties in the characterization of CD8+ Tregs that lack suitable markers have a considerably limited research in this area. Moreover, the induction and effector mechanisms of CD8+ Tregs remain unclear. Herein, we demonstrate the suitability of Ly49 and CD44 as markers for CD8+ Tregs. Our data also show that MHC class II restricted peptides induce CD8+CD44+Ly49+ Tregs via CD4+ T cell activation. Furthermore, we also found cross-suppressive activity of these CD8+ Tregs on responding CD4+ T cells in a cytotoxicity dependent manner. Our data provide new insights into the induction and function of CD8+ Tregs.

[Study of neutralization antibodie induced by DNA vaccine of HCV envelope protein 2 in mice].

OBJECTIVE: To explore the feasibility of induction of neutralization antibodies against hepatitis C virus (HCV) infection by HCV envelope 2 protein (E2) DNA vaccines immunization. METHODS: Two kinds of expression plasmids of HCV envelope 2 protein, plasmid pCI-1b661 Delta encoding hydrophobic carboxyl terminal truncated E2 and pCI-1b661 Delta encoding E2 with deletion of hypervariable region 1 (HVR1) and carboxyl terminal, were constructed and respectively transfeted 293T cells, and truncated E2 protein in whole cell lysate and supernatant of 293T cells were analyzed by Western blot. After BALB/c mouse were intramuscularly immunized by the plasmids, sera antibodies against HVR1 were detected by ELISA and the neutralization activity of the antibodies were assayed with HCV pseudotype particle (HCVpp). RESULTS: Both plasmids could express secretary truncated E2 protein. All the mice immunized with plasmid pCI-1b661 produced HVR1 antibodies,while no HVR1 antibodies were detected in pCI-1b661 Delta immunized mice. The sera neutralization percentages against HCVpp in pCI1lb661 Delta and pCI-lb661 Delta immunized mice were (78.5 +/- 13.8)% and (38.7 +/- 6.5)%, respectively (P <0.01). Sera neutralization activity against HCVpp was positive correlated with the level of HVR1 antibodies in pCI-1b661 immunized mice (r = 0.967, P<0.01). CONCLUSION: DNA vaccines expressing truncated E2 protein could induce neutralization antibodies against HCV, and neutralization antibodies mainly was consisted of the antibodies against HVR1.

Identification of a vaccine candidate antigen, PfMAg-1, from Plasmodium falciparum with monoclonal antibody M26-32.

Monoclonal antibody M26-32 has been shown to strongly inhibit the growth of Plasmodium falciparum in vitro. To identify the target antigen of M26-32, a P. falciparum Dd2 asexual stage cDNA expression library was screened with this antibody, and a full open reading frame cDNA was obtained. This gene, named pfmag-1, encodes a polypeptide of 589 amino acids. The protein PfMAg-1 was characterized as a membrane-associated protein that expressed on the surface of merozoite during erythrocytic stage. Remarkably, at the C terminus of PfMAg-1, there are 14 copies of a deca-peptide sequence of QTDEIKND (H/N) I. This tandem repeat domain was identified to harbor the epitope of the protective M26-32 monoclonal antibody, and was also recognized by sera of patients infected with P. falciparum. Rabbit antibody elicited against this deca-peptide repeat domain effectively inhibited P. falciparum invasion in vitro. Our work suggests that PfMAg-1 is a promising malaria vaccine candidate.