XAF1 Protects Host against Emerging RNA Viruses by Stabilizing IRF1-Dependent Antiviral Immunity.

XIAP-associated factor 1 (XAF1) is an interferon (IFN)-stimulated gene (ISG) that enhances IFN-induced apoptosis. However, it is unexplored whether XAF1 is essential for the host fighting against invaded viruses. Here, we find that XAF1 is significantly upregulated in the host cells infected with emerging RNA viruses, including influenza, Zika virus (ZIKV), and SARS-CoV-2. IFN regulatory factor 1 (IRF1), a key transcription factor in immune cells, determines the induction of XAF1 during antiviral immunity. Ectopic expression of XAF1 protects host cells against various RNA viruses independent of apoptosis. Knockout of XAF1 attenuates host antiviral innate immunity in vitro and in vivo, which leads to more severe lung injuries and higher mortality in the influenza infection mouse model. XAF1 stabilizes IRF1 protein by antagonizing the CHIP-mediated degradation of IRF1, thus inducing more antiviral IRF1 target genes, including DDX58, DDX60, MX1, and OAS2. Our study has described a protective role of XAF1 in the host antiviral innate immunity against RNA viruses. We have also elucidated the molecular mechanism that IRF1 and XAF1 form a positive feedback loop to induce rapid and robust antiviral immunity. IMPORTANCE Rapid and robust induction of antiviral genes is essential for the host to clear the invaded viruses. In addition to the IRF3/7-IFN-I-STAT1 signaling axis, the XAF1-IRF1 positive feedback loop synergistically or independently drives the transcription of antiviral genes. Moreover, XAF1 is a sensitive and reliable gene that positively correlates with the viral infection, suggesting that XAF1 is a potential diagnostic marker for viral infectious diseases. In addition to the antitumor role, our study has shown that XAF1 is essential for antiviral immunity. XAF1 is not only a proapoptotic ISG, but it also stabilizes the master transcription factor IRF1 to induce antiviral genes. IRF1 directly binds to the IRF-Es of its target gene promoters and drives their transcriptions, which suggests a unique role of the XAF1-IRF1 loop in antiviral innate immunity, particularly in the host defect of IFN-I signaling such as invertebrates.

A Novel Sushi-IL15-PD1 CAR-NK92 Cell Line With Enhanced and PD-L1 Targeted Cytotoxicity Against Pancreatic Cancer Cells.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and lethal malignancy with a limited response to current therapies. Novel and effective treatment is urgently needed. Herein, a chimeric antigen receptor (CAR)-NK92 cell line, with an interleukin (IL)-15Rα-sushi/IL-15 complex and a Programmed cell death-1(PD1) signal inverter was constructed and named SP ( S ushi-IL15- P D1). We showed that CAR expression enabled SP cells to proliferate independently of IL-2 and became more resistant to nutrition starvation-induced apoptosis. Meanwhile, SP cells were more effective than NK92 in PDAC cell killing assays in vitro and in vivo, and there was a positive correlation between the killing capability of SP cells and PD-L1 expression in pancreatic cancer cells. Based on the synergistic and comprehensive effects of the special CAR structure, the adhesion, responsiveness, degranulation efficiency, targeted delivery of cytotoxic granule content, and cytotoxicity of SP cells were significantly stronger than those of NK92. In conclusion, the SP cell line is a promising adoptive immunotherapy cell line and has potential value as an adjuvant treatment for pancreatic cancer, especially in patients with high PD-L1 expression.

Polysaccharides as Potential Anti-tumor Biomacromolecules -A Review.

Cancer, as one of the most life-threatening diseases, has attracted the attention of researchers to develop drugs with minimal side effects. The bioactive macromolecules, such as the polysaccharides, are considered the potential candidates against cancer due to their anti-tumor activities and non-toxic characteristics. The present review provides an overview on polysaccharides' extraction, isolation, purification, mechanisms for their anti-tumor activities, structure-activity relationships, absorption and metabolism of polysaccharides, and the applications of polysaccharides in anti-tumor therapy. Numerous research showed extraction methods of polysaccharides had a significant influence on their activities. Additionally, the anti-tumor activities of the polysaccharides are closely related to their structure, while molecular modification and high bioavailability may enhance the anti-tumor activity. Moreover, most of the polysaccharides exerted an anti-tumor activity mainly through the cell cycle arrest, anti-angiogenesis, apoptosis, and immunomodulation mechanisms. Also, recommendations were made to utilize the polysaccharides against cancer.

Characterization, antioxidant, antineoplastic and immune activities of selenium modified Sagittaria sagittifolia L. polysaccharides.

This study proposed an optimal way to supplement organic selenium, boost polysaccharides solubility, antioxidant, anticancer, immune responses. A purified polysaccharide fraction of Sagittaria sagittifolia L. (PSSP) was successfully modified with selenium (Se-PSSP), and its characteristics, antioxidant, antineoplastic and immune activities were studied. The structure and the monosaccharide composition were determined by means of UV-visible spectrometry, FT-IR spectra, NMR spectra, X-ray diffraction spectroscopy (XRD), scanning electron microscope (SEM) and atomic force microscope (AFM). The results showed that both PSSP and Se-PSSP contained a pyranoid polysaccharide linked by α-glycosidic bonds in the main chain. In addition, PSSP and Se-PSSP were amorphous morphology without three-helix conformation. PSSP (47.12 kDa) was mainly composed of glucose, mannose and xylose with molar percentages of 55.82%, 14.86% and 14.35%, respectively. Se-PSSP (16.82 kDa) is mainly composed of glucose, xylose and galactose with molar percentages of 26.49%, 18.76% and 18.14%, respectively. Compared with PSSP, Se-PSSP showed stronger water-solubility, antioxidant activity, cytotoxicity and immunomodulatory activity than that of PSSP. These results suggested that Se-PSSP is a promising novel Se-supplement and may be served as an excellent potential antioxidant, antineoplastic, and immunomodulatory agents in the field of functional foods and medicine industry.

Purification, characterization, antioxidant and immunological activity of polysaccharide from Sagittaria sagittifolia L.

As a healthy food and traditional Chinese medicine, sagittaria sagittifolia L. has been used for a long history. Nevertheless, reports on the bioactivity and chemical characterization of S. sagittifolia L. polysaccharides are still very rare. In this paper, ultrasound-assisted method (UAE) was used to extract S. sagittifolia L. polysaccharides, after alcohol precipitation and column chromatography isolation, the structural characteristics, antioxidant and immunological activities of the purified polysaccharide (SPU60-W) were preliminarily investigated. The results indicated SPU60-W (16.62 kDa) was a pyranoid polysaccharide containing α-glycosidic bond composed of mannose, xylose, and glucose with a molar ratio of 2.69: 2.04: 95.27. It consisted of slender wormlike strands, which may involve some degree of aggregation of helices, as well as a small proportion of irregular spherical structures. Furthermore, antioxidant activity analysis showed that SPU60-W possess excellent hydroxyl and ABTS radical scavenging activity comparable to vitamin C (Vc), and moderate DPPH radical scavenging activity. Immunity tests suggested that SPU60-W significantly promoted the proliferation, phagocytosis and NO production of mouse macrophage RAW264.7. According to this study, SPU60-W might be utilized as a potent antioxidant and immunomodulator in food and medicinal industry.

Effect of alkali concentration on digestibility and absorption characteristics of rice residue protein isolates and lysinoalanine.

The effect of alkali concentration on the digestibility and absorption characteristics of rice residue protein isolates (RPI) and lysinoalanine (LAL) was studied. When NaOH concentration was 0.03 M, the in vitro digestibility of RPI reached a maximum, and when NaOH concentration was higher than 0.03 M, the in vitro digestibility decreased. Alkali treatment reduced the release of all amino acids, especially arginine, lysine, phenylalanine, tyrosine, cysteine, and threonine. LAL only released 2.65-9.28% of the total LAL content, which was mainly combined with longer peptide chains, and the molecular weight was mostly accumulated between 1000 Da and 3000 Da. The experimental model of rats in the small intestine perfusion showed that the high alkali concentration significantly reduced the absorption rate of RPI, and LAL had no specific absorption site in the small intestine of rats, and was not available for intestinal absorption.

Vitexin ameliorates high fat diet-induced obesity in male C57BL/6J mice via the AMPKα-mediated pathway.

Vitexin, a bioactive compound isolated from hawthorn leaf extracts, has been reported to exhibit many biological activities, such as anticancer, antioxidation, and adipogenesis inhibition activities. The current study explored the effects of vitexin on high fat diet (HFD)-induced obesity/adipogenesis in male C57BL/6J mice and 3T3-L1 adipocytes, as well as the underlying mechanisms thereof. Vitexin significantly mitigated HFD-induced body weight gain and adiposity. Vitexin also partially normalized serum, hepatic lipid contents, and decreased adipocyte size induced by the HFD. Consistently, there were significant effects of vitexin on important regulators of lipid metabolism, including AMP-activated protein kinase-α (AMPKα), CAATT element binding protein-α (C/EBPα), and fatty acid synthase (FAS) in white adipose tissue. Moreover, vitexin significantly inhibited fat accumulation in 3T3-L1 adipocytes, and this was totally abolished by compound C (an AMPKα inhibitor). These results suggest that vitexin may prevent HFD-induced obesity/adipogenesis via the AMPKα mediated pathway.

Protein Hydrolysates' Absorption Characteristics in the Dynamic Small Intestine In Vivo.

Background: Dietary proteins are known for their wide range of nutritional, functional and biological properties. Although the total amount of proteins may be obtained from mixtures, its "availability" for absorption in the gut is in many cases quite uncertain or even varies for the same food depending on processing conditions, the presence of other components, and so on. Methods: To obtain accurate protein hydrolysate absorption data, we have developed a small intestine model (SIM) to test them. Results: The results indicated that the protein hydrolysates were absorbed rapidly during the first 15 min, and then decreased to 90 min, then they were absorbed again from 90 min to the endpoint. The protein absorption was also affected by the protein processing method used. The Enzyme + Ultrasound (EU) processing method group had a higher absorption rate than the Enzyme (E) processing method group, and the absorption of the Enzyme + Artificial gastric juice processing method (EH) and Enzyme + Ultrasound + Artificial gastric juice processing method (EUH) groups was reduced compared to the E group alone. The amino acid analysis results showed that the amino acids were reduced and absorbed by our SIM in almost all groups except for cysteine and methionine. In general, the Pearson relation value of the amino acid contents between before SIM and after SIM was 0.887, which indicated that single amino acid absorption was mainly related to its content in the whole amino acids. The single amino acid absorption ratio among different groups also displayed differences, which ranged from 31% to 46% (E group from 39% to 42%; EU group from 40% to 47%; EH group from 31% to 39%; EUH group from 35% to 41%). CONCLUSIONS: The protein hydrolysates' varied from startpoint to endpoint, and the protein absorption was affected by processing method.

Potential diagnostic value of serum p53 antibody for detecting colorectal cancer: A meta-analysis.

Numerous studies have assessed the diagnostic value of serum p53 (s-p53) antibody in patients with colorectal cancer (CRC); however, results remain controversial. The present study aimed to comprehensively and quantitatively summarize the potential diagnostic value of s-p53 antibody in CRC. The present study utilized databases, including PubMed and EmBase, systematically regarding s-p53 antibody diagnosis in CRC, accessed on and prior to 31 July 2016. The quality of all the included studies was assessed using quality assessment of studies of diagnostic accuracy (QUADAS). The result of pooled sensitivity, pooled specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were analyzed and compared with overall accuracy measures using diagnostic odds ratios (DORs) and area under the curve (AUC) analysis. Publication bias and heterogeneity were also assessed. A total of 11 trials that enrolled a combined 3,392 participants were included in the meta-analysis. Approximately 72.73% (8/11) of the included studies were of high quality (QUADAS score >7), and all were retrospective case-control studies. The pooled sensitivity was 0.19 [95% confidence interval (CI), 0.18-0.21] and pooled specificity was 0.93 (95% CI, 0.92-0.94). Results also demonstrated a PLR of 4.56 (95% CI, 3.27-6.34), NLR of 0.78 (95% CI, 0.71-0.85) and DOR of 6.70 (95% CI, 4.59-9.76). The symmetrical summary receiver operating characteristic curve was 0.73. Furthermore, no evidence of publication bias or heterogeneity was observed in the meta-analysis. Meta-analysis data indicated that s-p53 antibody possesses potential diagnostic value for CRC. However, discrimination power was somewhat limited due to the low sensitivity.

Neuroprotective effects of lotus seedpod procyanidins on extremely low frequency electromagnetic field-induced neurotoxicity in primary cultured hippocampal neurons.

The present study investigated the protective effects of lotus seedpod procyanidins (LSPCs) on extremely low frequency electromagnetic field (ELF-EMF)-induced neurotoxicity in primary cultured rat hippocampal neurons and the underlying molecular mechanism. The results of MTT, morphological observation, superoxide dismutase (SOD) and malondialdehyde (MDA) assays showed that compared with control, incubating neurons under ELF-EMF exposure significantly decreased cell viability and increased the number of apoptotic cells, whereas LSPCs evidently protected the hippocampal neurons against ELF-EMF-induced cell damage. Moreover, a certain concentration of LSPCs inhibited the elevation of intracellular reactive oxygen species (ROS) and Ca(2+) level, as well as prevented the disruption of mitochondrial membrane potential induced by ELF-EMF exposure. In addition, supplementation with LSPCs could alleviate DNA damage, block cell cycle arrest at S phase, and inhibit apoptosis and necrosis of hippocampal neurons under ELF-EMF exposure. Further study demonstrated that LSPCs up-regulated the activations of Bcl-2, Bcl-xl proteins and suppressed the expressions of Bad, Bax proteins caused by ELF-EMF exposure. In conclusion, these findings revealed that LSPCs protected against ELF-EMF-induced neurotoxicity through inhibiting oxidative stress and mitochondrial apoptotic pathway.

Procyanidins, from Castanea mollissima Bl. shell, induces autophagy following apoptosis associated with PI3K/AKT/mTOR inhibition in HepG2 cells.

Procyanidins from Castanea mollissima Bl. shell (CSPCs) induced autophagy and apoptosis in HepG2 cells and its mechanism remains to be examined. In this paper, autophagy was measured by the lipid modification of light chain-3 (LC3) and the formation of autophagosomes. Hoechst 33258 staining and flow cytometer analysis were used to measure apoptosis. The western blot analysis was used to examine the effects of CSPCs on the expression of LC3, PI3K, phosphorylation of AKT, mTOR, Bcl-2, Bad, Bax, BID and cleaved caspase 3 in HepG2 cells. The results showed that 3-methyladenine (3-MA) and apoptosis inhibitor (Z-VAD) could inhibited the death of HepG2 induced by CSPCs for 48h (150µg/mL). CSPCs induced the accumulation of autophagosomes and microtubule-associated proteins light chain 3-II (LC3-II, a marker of autophagy). P-AKT, PI3K and mTOR were significantly decreased on CSPCs exposure. However, these phenomena were not observed in the group pretreated with the autophagy inhibitor 3-MA and Z-VAD. CSPCs also induced the expression of Bad, Bax and Beclin-1 proteins and decreased the expression of Bcl-2, which was inhibited by 3-MA and Z-VAD. Moreover the apoptotic cell death could be inhibited by 3-MA. In addition, inhibition of LC3-II by siRNA-dependent knockdown attenuated the cleavage of caspase 3. These results suggested CSPCs could trigger autophagy via inhibition of the PI3K/AKT/mTOR signaling pathway, enhanced apoptosis in HepG2 cells which may be associated with the mitochondria-dependent signaling way.

Procyanidins from Nelumbo nucifera Gaertn. Seedpod induce autophagy mediated by reactive oxygen species generation in human hepatoma G2 cells.

In this study, autophagic effect of procyanidins from lotus (Nelumbo nucifera Gaertn.) seedpod (LSPCs) on human hepatoma G2 (HepG2) cells, and the inherent correlation between autophagic levels and reactive oxygen species (ROS) generation were investigated. The results showed that LSPCs increased monodansylcadaverine (MDC) fluorescence intensity and LC3-I/LC3-II conversion in HepG2 cells. In addition, the typically autophagic characteristics (autophagosomes and autolysosomes) were observed in LSPCs-treated cells, but not found in the cells treated with autophagy inhibitor 3-methyladenine (3-MA). Furthermore, the elevated ROS level was in line with the increasing of autophagy activation caused by LSPCs, however, both 3-MA and the ROS scavenger N-acetylcyteine (NAC) inhibitors effectively suppressed the autophagy and ROS generation triggered by LSPCs. As a result, these results indicated that LSPCs induced HepG2 cell autophagy in a time- and dose-dependent manner, and promoted reactive oxygen species (ROS) generation on HepG2 cells. Moreover, we found that LSPCs caused DNA damage, S phase arrest and the decrement of mitochondria membrane potential (MMP) which were associated with ROS generation. In summary, our findings demonstrated that the LSPCs-induced autophagy and autophagic cell death were triggered by the ROS generation in HepG2 cells, which might be associated with ROS generation through the mitochondria-dependent signaling way.

Determination of bioavailability and identification of collagen peptide in blood after oral ingestion of gelatin.

BACKGROUND: Gelatin has long been widely used in foods, pharmaceuticals, cosmetics, and other products. However, there are few reports on its bioavailability and bioavailable forms. In this study, the bioavailability of gelatin was indirectly evaluated by the determining the bioavailability of total hydroxyproline in gelatin using a pharmacokinetic method after oral administration to rats. RESULTS: The relative and absolute bioavailability of gelatin were 74.12% and 85.97%, respectively. The amino acid profile of plasma indicated that 41.91% of the digested gelatin was absorbed from the intestine in the form of peptide, and there was a good linear correlation between the absorbed amount of an amino acid and its content in gelatin (R(2) = 0.9566). Moreover, 17 types of collagen peptide were purified by multi-step chromatography and identified with ultra-performance liquid chromatography-electrospray ionisation-mass spectrometry. CONCLUSION: Gelatin had high oral bioavailability. Nearly half of digested gelatin was absorbed from the intestine in the form of various collagen peptides.

Autophagic cell death of human hepatoma G2 cells mediated by procyanidins from Castanea mollissima Bl. Shell-induced reactive oxygen species generation.

The autophagy of human hepatoma G2 (HepG2) cells induced by procyanidins from chestnut (Castanea mollissima Bl.) shell (CSPCs) was investigated, and the inherent relationship between autophagic levels and reactive oxygen species (ROS) generation was studied. The results showed that CSPCs induced HepG2 cell death in a time- and concentration-dependent manner, increased the accumulation of autophagolysosomes and microtubule-associated proteins light chain 3-II (LC3-II, a marker of autophagy). However, these phenomena were not observed in the group pretreated with the autophagy inhibitor 3-MA, suggesting that CSPCs induced HepG2 cell autophagy. Furthermore, we found that CSPCs triggered ROS generation in cells, while the levels of ROS decreased in the N-acetylcysteine (Nac) co-treatment, revealing that CSPCs-mediated autophagy was partly blocked by Nac. In addition, treatment with CSPCs decreased the mitochondrial membrane potential of HepG2 cells. These results suggested CSPCs could trigger autophagy via ROS generation, which may be associated with the mitochondria-dependent signaling way.

Expression and localization of Bombyx mori V-ATPase 16 kDa subunit c.

V-ATPase plays a central role in lepidopteran midgut ion transport physiology, and lepidopteran midgut turned out to be a model tissue for the study of V-ATPase. In the present study, the 5'-RACE method is used to obtain the 5'-UTR of V-ATPase c subunit gene from Bombyx mori. Sequence analysis of the promoter region and 3'-UTR of V-ATPase c subunit gene revealed that the transcription of the V-ATPase c subunit gene may be regulated by multi-ways. RT-PCR analysis showed that B. mori V-ATPase c subunit mRNA expresses in the whole developmental stages of B. mori. We also constructed a transient vector to determine the subcellular localization of the B. mori V-ATPase c subunit, and the result demonstrated that it is located in the membrane and some specific regions of BmN cells. Real-time PCR analysis further indicated that the c subunit mRNA expression was upregulated significantly at 24 and 72 h in the midguts of resistant B. mori larvae after being inoculated with B. mori nucleopolyhedrovirus, suggesting that it may be related to the immune response against virus infection.

Characterization of Bombyx mori parvo-like virus non-structural protein NS1.

NS1 gene of Bombyx mori parvo-like virus (China Zhenjiang isolate, BmDNV-Z) codes a predicted 316-amino acid protein, but its function remains unknown. Results of the current study showed that purified recombinant 6 x His-NS1 protein possesses ATP binding, ATPase, DNA binding, and helicase activities. Only one protein was captured in infected Bombyx mori midgut cells against NS1 target protein by employing co-immunoprecipitation, which was identified to be a viral protein by mass spectrometry. The NS1-interacting protein is encoded by BmDNV-Z ORF4 and its molecular is about 100 kD. Analysis of His pull-down confirmed that binding of identified viral protein to purified recombinant 6 x His-NS1 protein in vitro. Taken together, our results indicated that BmDNV-Z NS1 was a multifunctional protein, which may be involved with virus replication.