Publications by authors named "Yongling Lu"

44 Publications

GASC1 promotes hepatocellular carcinoma progression by inhibiting the degradation of ROCK2.

Cell Death Dis 2021 Mar 10;12(3):253. Epub 2021 Mar 10.

Department of Infectious Diseases, The Second Affiliated Hospital of Chongqing Medical University, 400038, Chongqing, PR China.

Hepatocellular carcinoma (HCC) is a devastating malignancy without targeted therapeutic options. Our results indicated that the histone demethylase GASC1 signature is associated with later tumor stage and poorer survival in HCC patients. GASC1 depletion led to diminished HCC proliferation and tumor growth. A distinct heterogeneity in GASC1 levels was observed among HCC cell populations, predicting their inherent high or low tumor-initiating capacity. Mechanistically, GASC1 is involved in the regulation of several components of the Rho-GTPase signaling pathway including its downstream target ROCK2. GASC1 demethylase activity ensured the transcriptional repression of FBXO42, a ROCK2 protein-ubiquitin ligase, thereby inhibiting ROCK2 degradation via K63-linked poly-ubiquitination. Treatment with the GASC1 inhibitor SD70 impaired the growth of both HCC cell lines and xenografts in mice, sensitizing them to standard-of-care chemotherapy. This work identifies GASC1 as a malignant-cell-selective target in HCC, and GASC1-specific therapeutics represent promising candidates for new treatment options to control this malignancy.
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http://dx.doi.org/10.1038/s41419-021-03550-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946911PMC
March 2021

Diphenyleneiodonium enhances P2X7 dependent non-opsonized phagocytosis and suppresses inflammasome activation via blocking CX43-mediated ATP leakage.

Pharmacol Res 2021 Apr 30;166:105470. Epub 2021 Jan 30.

Clinical Medical Research Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China. Electronic address:

The beneficial effects of antioxidants against oxidative stress have been well described. However, the pharmacological impacts of antioxidants other than inhibiting the production of reactive oxygen species (ROS) remain less understood. This study demonstrated that diphenyleneiodonium (DPI), a canonical NADPH oxidase 2 (NOX2) inhibitor, effectively promoted non-opsonized bacterial phagocytosis. Indeed, DPI abrogated the elevation in the extracellular ATP level of Escherichia coli (E. coli) -infected murine peritoneal macrophages, thereby restoring the association of the purinergic receptor P2X7 with non-muscle myosin heavy chain 9 (MYH9) to upregulate the P2X7 -dependent phagocytosis of E. coli. DPI also suppressed inflammasome activation and reduced necroptosis in E. coli-infected macrophages by decreasing extracellular ATP levels. Mechanistically, DPI upregulated p38 MAPK phosphorylation to suppress the expression and activity of the hemichannel protein connexin 43 (CX43), leading to the inhibition of CX43-mediated ATP efflux in E. coli-infected macrophages. In a murine E. coli infection model, DPI effectively reduced ATP release, decreased bacterial load and inhibited inflammasome activation, thereby improving survival and ameliorating organ injuries in model mice. In summary, our study demonstrates a previously unknown function of DPI in conferring protection against bacterial infection and suggests a putative antimicrobial strategy of modulating CX43 -dependent ATP leakage.
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http://dx.doi.org/10.1016/j.phrs.2021.105470DOI Listing
April 2021

Pathway engineering of Saccharomyces cerevisiae for efficient lycopene production.

Bioprocess Biosyst Eng 2021 Jan 24. Epub 2021 Jan 24.

College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816, Jiangsu, China.

To construct a Saccharomyces cerevisiae strain for efficient lycopene production, we used a pathway engineering strategy based on expression modules comprising fusion proteins and a strong constitutive promoter. The two recombinant plasmids pEBI encoding the fusion genes with an inducible promoter, as well as pIETB with a constitutive promoter and terminator were introduced into S. cerevisiae YPH499 and BY4741 to obtain the four recombinant strains ypEBI, ypIETB, byEBI and byIETB. The lycopene production and the transcription levels of key genes were higher in the BY4741 chassis than in YPH499. Accordingly, the content of total and unsaturated fatty acids was also higher in BY4741, which also exhibited a decrease of glucose, increase of trehalose, increase of metabolite in citrate cycle, and low levels of amino acids. These changes rerouted metabolic fluxes toward lycopene synthesis, indicating that the BY4741 chassis was more suitable for lycopene synthesis. The lycopene content of bpIETB in SG-Leu medium supplemented with 100 mg/L of linolenic acid reached 10.12 mg/g dry cell weight (DCW), which was 85.7% higher than without the addition of unsaturated fatty acids. The constitutive promoter expression strategy employed in this study achieved efficient lycopene synthesis in S. cerevisiae, and the strain bpIETB was obtained a suitable chassis host for lycopene production, which provides a basis for further optimization of lycopene production in artificial synthetic cells and a reference for the multi-enzyme synthesis of other similar complex terpenoids.
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http://dx.doi.org/10.1007/s00449-020-02503-5DOI Listing
January 2021

Inhibitory Activity on the Formation of Reactive Carbonyl Species in Edible Oil by Synthetic Polyphenol Antioxidants.

J Agric Food Chem 2021 Jan 17. Epub 2021 Jan 17.

Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning, Hainan 571533, People's Republic of China.

Food lipids play an important role in food quality, and their attributes contribute to texture, flavor, and nutrition. However, high-temperature processing leads to lipid peroxidation, degradation, and the formation of reactive carbonyl species (RCS), such as acrolein (ACR), glyoxal (GO), and methylglyoxal (MGO). We investigated the changes in the peroxidation value (POV), Rancimat induction time, formation and total amount of RCS, and inhibitory effects of synthetic polyphenol antioxidants on ACR/GO/MGO in plant oils during heating processing through an accelerated oxidation test using Rancimat. With increasing temperature and heating time, the amounts of ACR, GO, and MGO in oil increased and the level of ACR was about several times higher than that of GO and MGO. We also found that some amounts of ACR, GO, and MGO were produced at the initial stage before reaching the peak value of POV, even before oil oxidative rancidity, and the common antioxidant butyl hydroxyanisole (BHA)/butylated hydroxytoluene (BHT) could not remove them once they were generated. This is first time to purify PG-ACR-MGO and elucidate the structure based on analysis of their high resolution mass spectrometry and H, C, and two-dimensional nuclear magnetic resonance. We further found that PG rather than BHT and BHA efficiently trapped ACR, OG, and MGO to form adducts in oil and roasted beef burgers with corn oil. Additionally, after incubation at 80 °C, the trapping order of PG was as follows: ACR, MGO, and GO, and the adduct of PG-ACR was formed within 1 min; after 10 min, PG-MGO was generated; and three adducts formed at 15 min. However, PG could not trap ACR, GO, or MGO to form adducts at room temperature. This study provided novel knowledge to advance our understanding of the ability of synthetic polyphenol antioxidants to scavenge RCS simultaneously, such as ACR, MGO, and GO. Our findings demonstrated that PG, as an inhibitor of RCS, is suitable for medium- and high-temperature food processing but not for normal-temperature storage.
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http://dx.doi.org/10.1021/acs.jafc.0c07248DOI Listing
January 2021

Gold nanoparticles synergize with bacterial lipopolysaccharide to enhance class A scavenger receptor dependent particle uptake in neutrophils and augment neutrophil extracellular traps formation.

Ecotoxicol Environ Saf 2021 Mar 10;211:111900. Epub 2021 Jan 10.

Medical Research Center, Southwest Hospital, Army Military Medical University, Chongqing 400038, China. Electronic address:

Gold nanoparticles (AuNPs) are extensively utilized in biomedical fields. However, their potential interaction with host cells has not been comprehensively elucidated. In this study, we demonstrated a size-dependent effect of AuNPs to synergize with bacterial lipopolysaccharide (LPS) in promoting neutrophil extracellular traps (NETs) release in human peripheral neutrophils. Mechanistically, LPS was more efficient to contact with 10 nm AuNPs and promote their uptake in neutrophils compared to 40 and 100 nm AuNPs, leading to a synergistic upregulation of class A scavenger receptor (SRA) which mediated AuNPs uptake and triggered activation of extracellular regulated protein kinase (ERK) and p38. Blocking SRA or inhibiting ERK and p38 activation remarkably abrogated the effect of AuNPs and LPS to induce NETs formation. Further experiments demonstrated that AuNPs and LPS augmented the production of cytosolic reactive oxygen species (ROS) in p38 and ERK dependent manner, through upregulating and activating NADPH oxidase 2 (NOX2). Accordingly, scavenging of ROS or inhibiting the NOX2 dampened NETs release induced by combined AuNPs and LPS treatment. AuNPs and LPS also synergized to upregulate reactive oxygen species modulator 1 (ROMO1) via activating ERK, thereby increasing mitochondrial ROS generation and promoting the release of NETs. In summary, we provide new evidences about the synergy of AuNPs and LPS to augment cellular responses in neutrophils, which implicates the need to consider the amplifying effect by pathogenic stimuli when utilizing nanomaterials in infectious or inflammatory conditions.
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http://dx.doi.org/10.1016/j.ecoenv.2021.111900DOI Listing
March 2021

Trapping of Acrolein by Curcumin and the Synergistic Inhibition Effect of Curcumin Combined with Quercetin.

J Agric Food Chem 2021 Jan 29;69(1):294-301. Epub 2020 Dec 29.

Department of Food Science and Technology, School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Nanjing 210023, P. R. China.

Acrolein (ACR) is a toxic unsaturated aldehyde that is formed during different steps of thermal food processing. Here, we explored the kinetics of curcumin and ACR and elucidated the pathway of curcumin trapping ACR by preparing a mono-adduct of ACR (CMA-1) conjugated with curcumin. The synergistic scavenging effect and mechanism of curcumin combined with quercetin on ACR was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Comparing the uses of curcumin and quercetin both individually and in combination, we found that quercetin in combination resulted in more curcumin being transformed into CMA-2, while curcumin in combination made the amount of di-ACR conjugated to quercetin (QDA) increase. We also added combined curcumin and quercetin into grilled chicken wings to demonstrate that curcumin and quercetin could scavenge ACR by forming their own ACR adducts and antioxidant activity during the process. Our results have noted a new strategy, in which some combinations of dietary polyphenols might contribute to the removal of toxic ACR produced during thermal food processing.
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http://dx.doi.org/10.1021/acs.jafc.0c06692DOI Listing
January 2021

Trapping Acrolein by Theophylline/Caffeine and Their Metabolites from Green Tea and Coffee in Mice and Humans.

J Agric Food Chem 2020 Dec 30;68(49):14471-14479. Epub 2020 Nov 30.

Department of Food Science and Technology, School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2# Xuelin Road, Nanjing 210023, P.R. China.

Acrolein (ACR) is found exogenously as a widespread environmental pollutant and endogenously, where it is thought to be involved as a pathogenic factor in the progression of many pathological conditions. Eliminating ACR by dietary-active substances has been found to be one potential strategy to prevent ACR-associated chronic diseases. This study first compared the scavenging ACR efficacy of four purine alkaloids, theophylline (TP), paraxanthine (PXT), theobromine (TB), and caffeine (CAF), and then, TP, CAF, and their metabolites were investigated for their ability to trap ACR . Our results indicated that TP, which possesses an -NH moiety at the N-7 position, exhibits the best ACR-trapping capacity , while CAF has a slight ability to trap ACR due to the substitutions by -CH at the N-1, N-3, and N-7 positions. After oral administration of TP or CAF, the ACR adducts of TP and the metabolites of TP or CAF (e.g., mono- and di-ACR-TP, mono-ACR-1,3-DMU, and mono-ACR-1-MU) were detected in urinary samples obtained from both TP- and CAF-treated mouse groups by using ultra-performance liquid chromatography-tandem mass spectrometry. The quantification studies demonstrated that TP and its metabolites significantly trapped ACR in a dose-dependent manner . Furthermore, we also detected those ACR adducts of TP and TP/CAF's metabolites in human urine after four cups of green tea (2 g tea leaf/cup) or two cups of coffee (4 g coffee/cup) were consumed per day. Those results indicated that dietary TP or CAF has the potential capacity to scavenge ACR
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http://dx.doi.org/10.1021/acs.jafc.0c05483DOI Listing
December 2020

The screening of albumin as a key serum component in preventing release of neutrophil extracellular traps by selectively inhibiting mitochondrial ROS generation.

Can J Physiol Pharmacol 2021 Apr 15;99(4):427-438. Epub 2020 Aug 15.

Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, 400016, China.

Neutrophil extracellular traps (NETs) are extracellular DNA webs released from neutrophils to mediate the host antimicrobial defense. As NETs could also induce thrombosis and cause organ injury, their release should be strictly controlled; however, the intrinsic mechanisms that prevent unfavorable NETs are not well understood. Herein, an accidental finding of NET release from human peripheral neutrophils was first described in a serum-free culture, which was later determined to be a conserved NET prevention effect of serum. In contrast to canonical NETs induced by phorbol-12-myristate-13-acetate (PMA), NET formation by serum-free culture was rapid and without prevalent NETosis. Next, albumin was screened out as a key serum component that mediated the suppression of NETs. Moreover, NETs induced upon serum or albumin deficiency were independent of the canonical pathway that involves NADPH oxidase 2 (NOX2) activation and cytosol reactive oxygen species (ROS) production. Instead, the generation of mitochondrial ROS (mtROS) was upregulated to promote NET release. Albumin exhibited mtROS scavenging activity and thus inhibited NETs. Serum-free culture also induced the release of NET-bound oxidized mtDNA, which stimulated interferon-β (IFN-β) production. Overall, our research provides new evidence that characterizes the NET production in serum-free culture and determines the mechanisms by which serum albumin inhibits NETs.
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http://dx.doi.org/10.1139/cjpp-2019-0670DOI Listing
April 2021

Acrolein-Trapping Mechanism of Theophylline in Green Tea, Coffee, and Cocoa: Speedy and Successful.

J Agric Food Chem 2020 Sep 25;68(36):9718-9724. Epub 2020 Aug 25.

Department of Food Science and Technology, School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2# Xuelin Road, Nanjing 210023, P. R. China.

Increasing evidence has identified the unsaturated aldehyde acrolein (ACR) as the potential factor that causes deoxyribonucleic acid cross-linking and the development of chronic diseases. The objective of this study was to investigate the mechanism by which theophylline (TP) scavenges ACR for the first time. TP efficiently scavenged ACR through forming adducts, which was demonstrated in a system in which TP was incubated with ACR at different ratios for different times for liquid chromatography with tandem mass spectrometry. Then, the mono- and di-ACR-TP adducts were purified, and their structures were elucidated by high-resolution mass spectrometry and nuclear magnetic resonance analysis. We found that the ACR residue on mono-ACR-TP further trapped one more ACR and formed di-ACR-TP adducts. Furthermore, mono- and di-ACR-TP had similar time-dependent ACR-scavenging activity to TP. Finally, we demonstrated that green tea, coffee, and cocoa inhibited ACR by trapping ACR to form mono- and di-ACR-TP adducts during the incubation of green tea, coffee, and cocoa with ACR.
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http://dx.doi.org/10.1021/acs.jafc.0c03895DOI Listing
September 2020

Artesunate reverses LPS tolerance by promoting ULK1-mediated autophagy through interference with the CaMKII-IP3R-CaMKKβ pathway.

Int Immunopharmacol 2020 Oct 3;87:106863. Epub 2020 Aug 3.

Medical Research Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, PR China; State Key Laboratory of Trauma, Burn and Combined Injury, Third Military Medical University, Chongqing 400038, PR China. Electronic address:

The progress of sepsis is increasingly recognized by the transition from early hyperinflammation to long term immunosuppression, which is characterized in innate immune cells by diminished responsiveness termed as lipopolysaccharide (LPS) tolerance. In this study, we investigated the ability of the antimalarial drug artesunate to reverse LPS tolerance and explored the underlying mechanisms. Initially, we detected a dramatic decline in autophagy accompanied by decreased cytokine production and impaired bacterial clearance by LPS tolerant macrophages. Then we demonstrated that artesunate restored cytokine production and enhanced bacterial clearance by inducing autophagy. Moreover, artesunate caused greater suppression of inhibitory phosphorylation than of activating phosphorylation of Unc-51 like autophagy activating kinase 1 (ULK1), a kinase that is essential for initiating autophagy through the inhibition of excessive AMP-activated protein kinase (AMPK) activation. This effect was shown to be achieved by suppression of Ca/calmodulin-dependent protein kinase II (CaMKII) phosphorylation, resulting in reduction of the inositol 1,4,5-triphate receptor (IP3R) dependent Ca release from the endoplasmic reticulum (ER) and inhibiting the overactive CaMKKβ-AMPK cascade. Administration of artesunate also upregulated autophagy and reversed the tolerant status in LPS tolerant mice. In summary, our findings reveal a novel immunopharmacological action of artesunate to reverse LPS tolerance by restoring autophagy. Our results may also indicate the significance of autophagy induction for treating immunosuppression in sepsis.
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http://dx.doi.org/10.1016/j.intimp.2020.106863DOI Listing
October 2020

Artesunate promotes the proliferation of neural stem/progenitor cells and alleviates Ischemia-reperfusion Injury through PI3K/Akt/FOXO-3a/p27 signaling pathway.

Aging (Albany NY) 2020 05 7;12(9):8029-8048. Epub 2020 May 7.

Department of Neurosurgery and Key Laboratory of Neurotrauma, Southwest Hospital, The Third Military Medical University (Army Military Medical University), Chongqing, China.

Stroke is one of the leading causes of death worldwide that also result in long-term disability. Endogenous neural stem/progenitor cells (NSPCs) within subventricular (SVZ) and dentate gyrus (DG) zone, stimulated by cerebral infarction, can promote neural function recovery. However, the proliferation of eNSPCs triggered by ischemia is not enough to induce neural repair, which may contribute to the permanent disability in stroke patients. In this study, our results showed that following the treatment with artesunate (ART, 150 mg/kg), the functional recovery was significantly improved, the infarct volume was notably reduced, and the expression of Nestin, a proliferation marker of NSPCs in the infarcted cortex, was also increased. Additionally, the proliferative activity of NSPCs with or without oxygen-glucose deprivation/reperfusion was significantly promoted by ART treatment, and the therapeutic concentration was 0.8 μmol/L (without OGD/R) or 0.4 μmol/L (with OGD/R) in the model. Furthermore, the effects of ART can be abolished by the treatment of PI3K inhibitor wortmannin. The expression levels of related molecules in PI3K/Akt/FOXO-3a/p27 signaling pathway (p-AKT, p-FOXO-3a, p27) were examined using western blotting. The results suggested ART could inhibit the transcriptional function of FOXO-3a by inducing its phosphorylation, subsequently downregulating p27 and enhancing neural stem cell proliferation in the infarcted cortex via PI3K/AKT signaling, further alleviating ischemia-reperfusion injury after ischemic stroke.
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http://dx.doi.org/10.18632/aging.103121DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7244066PMC
May 2020

Mechanistic studies of inhibition on acrolein by myricetin.

Food Chem 2020 Apr 11;323:126788. Epub 2020 Apr 11.

Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning, Hainan 571533, China. Electronic address:

Acrolein (ACR) is an unsaturated aldehyde with high activity and toxicity and is produced in vivo and in food. This study investigated the impact of B-ring structure on the trapping of ACR by flavonols and the trapping mechanism and efficacy of ACR by myricetin. Galangin, kaempferol, quercetin, and myricetin, which possess the same A- and C-ring but different numbers of -OH groups on the B-ring, were selected for this study. Our results suggested that increasing the number of -OH groups on the B-ring can enhance the ACR trapping efficacy of flavonol and myrectin was identified as the most active flavonol. The adducts of myricetin with ACR under different ratios and incubation times were analyzed using LC-MS/MS. We also purified and identified the major mono- and di-ACR-myricetin adducts. Furthermore, myricetin could dose-dependently inhibit the formation of ACR in cookies through the formation of mono- and di-ACR adducts.
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http://dx.doi.org/10.1016/j.foodchem.2020.126788DOI Listing
April 2020

Erratum to: The discovery of potent immunostimulatory CpG-ODNs widely distributed in bacterial genomes.

J Microbiol 2020 04;58(4):340

Institute of Modern Biopharmaceuticals, School of Life Sciences, Southwest University, Beibei, Chongqing, 400715, P. R. China.

In the article by Liu et al. published in Journal of Microbiology 2020; 58, 153-162, 1# The Supplementary data's consecutive numbers (Supplementary data Fig. S2) on 9 line of 4 paragraph in the section of 'Discussion.' on page 160 should be corrected in (Supplementary data Fig. S1). The sentence should have read: The results showed that the nonspecific internalization of T03 had only a slight competition with CpG-ODNs (Supplementary data Fig. S1).2# The Supplementary data's consecutive numbers (Supplementary data Fig. S3) on 13 line of 6 paragraph in the section of 'Discussion.' on page 161 should be corrected in (Supplementary data Fig. S2). The sentence should have read: Although the CpG-ODNs screened in this study had no or weak stimulation effect on human PBMCs (Supplementary data Fig. S2), it once again indicated that CpG-ODNs can be species-specific.And the Electronic Supplementary Material should be corrected as below. We apologize for any inconvenience that this may have caused.
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http://dx.doi.org/10.1007/s12275-020-9724-0DOI Listing
April 2020

The discovery of potent immunostimulatory CpG-ODNs widely distributed in bacterial genomes.

J Microbiol 2020 Feb 23;58(2):153-162. Epub 2019 Dec 23.

Institute of Modern Biopharmaceuticals, School of Life Sciences, Southwest University, Beibei, Chongqing, 400715, P. R. China.

Oligodeoxynucleotides containing unmethylated CpG dinucleotides (CpG-ODN) can be specifically recognized by Toll-like receptor 9 (TLR9), provoking innate immune responses. Designed according to this structural feature, many synthetic phosphorothioate CpG-ODNs successfully activate macrophages. However, it is difficult to find potent stimulatory CpG-DNA fragments in microbial genomes. Therefore, whether microbial CpG-DNA substantially contributes to infectious and immune diseases remains controversial. In this study, high-throughput scanning was carried out for thousands of bacterial genomes with bioinformatics tools to comprehensively evaluate the distribution of CpG-DNA fragments. A random sampling test was then performed to verify their immunostimulatory properties by experiments in vitro and in vivo. Natural TLR9-dependent and potent stimulatory CpG-DNA fragments were found in microbial genomes. Interestingly, highly conserved stimulatory CpG-DNA fragments were found in 16S and 23S rDNA sequences with multiple copies, while others were species-specific. Additionally, we found that the reported active motifs were mostly non-stimulatory in natural CpG fragments. This evidence indicates that the previous structural descriptions of functional CpG-ODNs are incomplete. Our study has assessed the distribution of microbial CpG-DNA fragments, and identified natural stimulatory CpG-DNA fragments. These findings provide a deeper understanding of CpG-ODN structures and new evidence for microbial DNA inflammatory function and pathogenicity.
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http://dx.doi.org/10.1007/s12275-020-9289-yDOI Listing
February 2020

A High Level of Circulating Valine Is a Biomarker for Type 2 Diabetes and Associated with the Hypoglycemic Effect of Sitagliptin.

Mediators Inflamm 2019 11;2019:8247019. Epub 2019 Nov 11.

Department of Endocrinology, Translational Research Key Laboratory for Diabetes, Xinqiao Hospital, Army Medical University (Former Name: Third Military Medical University), Chongqing, China.

Background: High levels of branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs) were associated with an increased risk of hyperglycemia and the onset of diabetes. This study is aimed at assessing circulating valine concentrations in subjects with type 2 diabetes (T2D) and in T2D patients and high-fat diet- (HFD-) fed mice treated with the hypoglycemic agent sitagliptin (Sit) and analyzing the association of valine concentrations with metabolic parameters.

Methods: Metabolomics in HFD-fed mice were analyzed by gas chromatography-mass spectrometry (GC-MS) systems. Plasma valine concentrations were detected with a commercial kit in 53 subjects with normal glucose levels ( = 19), newly diagnosed T2D ( = 20), placebo-treated T2D ( = 7), or Sit-treated T2D ( = 7). Biochemical parameters were also assessed in all participants.

Results: Sit treatment markedly changed the pattern of amino acid in HFD-fed mice, especially by reducing the level of the BCAA valine. Compared with the healthy controls, the plasma valine concentrations were significantly higher in the T2D patients ( < 0.05). Correlation analysis showed that the plasma valine concentration was positively correlated with the level of fasting plasma glucose ( < 0.05). Moreover, the plasma valine concentrations were notably reduced after Sit treatment in T2D patients ( < 0.05).

Conclusions: Our findings demonstrate an important effect of Sit on the BCAA valine in T2D patients and HFD-fed mice, revealing a new hypoglycemic mechanism of it. Furthermore, the results suggest that the circulating valine level might be a novel biomarker for T2D and restoring the level of valine might be a potential strategy for diabetes therapy.
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http://dx.doi.org/10.1155/2019/8247019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6885205PMC
June 2020

Quantitative Iron Neuroimaging Can Be Used to Assess the Effects of Minocycline in an Intracerebral Hemorrhage Minipig Model.

Transl Stroke Res 2020 06 6;11(3):503-516. Epub 2019 Nov 6.

Department of Neurosurgery and Key Laboratory of Neurotrauma, Southwest Hospital, The Third Military Medical University (Army Military Medical University), Chongqing, China.

Iron-mediated toxicity is a key factor causing brain injury after intracerebral hemorrhage (ICH). This study was performed to investigate the noninvasive neuroimaging method for quantifying brain iron content using a minipig ICH model and assess the effects of minocycline treatment on ICH-induced iron overload and brain injury. The minipig ICH model was established by injecting 2 ml of autologous blood into the right basal ganglia, which were then subjected to the treatments of minocycline and vehicle. Furthermore, the quantitative susceptibility mapping (QSM) was used to quantify iron content, and diffusion tensor imaging (DTI) was performed to evaluate white matter tract. Additionally, we also performed immunohistochemistry, Western blot, iron assay, Perl's staining, brain water content, and neurological score to evaluate the iron overload and brain injury. Interestingly, we found that the ICH-induced iron overload could be accurately quantified by the QSM. Moreover, the minocycline was quite beneficial for protecting brain injury by reducing the lesion volume and brain edema, preventing brain iron accumulation, downsizing ventricle enlargement, and alleviating white matter injury and neurological deficits. In summary, we suggest that the QSM be an accurate and noninvasive method for quantifying brain iron level, and the minocycline may be a promising therapeutic agent for patients with ICH.
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http://dx.doi.org/10.1007/s12975-019-00739-2DOI Listing
June 2020

SVCT2 Promotes Neural Stem/Progenitor Cells Migration Through Activating CDC42 After Ischemic Stroke.

Front Cell Neurosci 2019 19;13:429. Epub 2019 Sep 19.

Department of Neurosurgery and Key Laboratory of Neurotrauma, Southwest Hospital, Third Military Medical University (Army Military Medical University), Chongqing, China.

Ischemic stroke is one of the most leading diseases causing death/long-term disability worldwide. Activating endogenous neural stem/progenitors cells (NSPCs), lining in the subventricular zone (SVZ) and dentate gyrus, facilitates injured brain tissue recovery in both short and long-term experimental settings. While, only a few proliferated NSPCs migrate toward the lesions to enhance endogenous repair after ischemia. Here, the results indicated that the functional recovery was evidently improved and the infarct volume was significantly reduced with ascorbic acid (AA) treatment in a dose-dependent manner from 125 to 500 mg/Kg, and the suitable therapeutic concentration was 250 mg/Kg. The possible mechanism might be due to activating sodium-vitamin C cotransporter 2 (SVCT2), which was down-regulated in SVZ after ischemia. Furthermore, immunostaining images depicted the number of migrated NSPCs from SVZ were significantly increased with 250 mg/Kg AA treatment or SVCT2 overexpression under the physiological and pathological condition . Besides, the data also represented that 250 mg/Kg AA or SVCT2 overexpression facilitated NSPCs migration promoting F-actin assembling in the manner of up-regulating CDC42 expression using oxygen-glucose deprivation . Collectively, the present study indicates that SVCT2 promotes NSPCs migration through CDC42 activation to facilitate F-actin assembling, which enlarges the therapeutic scope of AA and the role of SVCT2 in NSPCs migration after brain injury.
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http://dx.doi.org/10.3389/fncel.2019.00429DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6761321PMC
September 2019

Lactic acid bacteria, Enterococcus faecalis Y17 and Pediococcus pentosaceus G11, improved growth performance, and immunity of mud crab (Scylla paramamosain).

Fish Shellfish Immunol 2019 Oct 18;93:135-143. Epub 2019 Jul 18.

Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou, 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China. Electronic address:

Mud crabs (Scylla paramamosain), a commercially important cultured species in the southeastern region of China, is usually infected by Vibriosis or parasites, causing great economic losses in cultured farms. Previous studies have demonstrated that probiotics benefited in enhancing the immune response against invading pathogens in aquatic animals. In this study, the effects of dietary administration of lactic acid bacteria (LAB) (Enterococcus faecalis Y17 and Pediococcus pentosaceus G11) on growth performance and immune responses of mud crab were assessed. Both strains (Y17 and G11) showed an inhibitory activity against bacterial pathogens (Aeromonas hydrophila, Vibrio parahaemolyticus, Vibrio alginolyticus, Staphylococcus aureus, and β Streptococcus), and a wide pH tolerance range of 2-10. In vivo, mud crabs were fed a control diet and experimental diets supplemented with 10 cfu g diet either Y17 or G11 for 6 weeks before subjecting to a challenge test with V. parahaemolyticus for 12 h. The probiotic-supplemented diets had significant effects on weight gain and specific growth rate during the feeding trial. Increased serum enzyme activities of phenoloxidase, lysozyme, and SOD were observed in the hemolymph of mud crab in Y17 and G11-supplemented groups compared to that in the controls (P < 0.01). The significantly up-regulated expression of gene CAT, LYS, proPO, and SOD could be seen in hepatopancreas in G11-supplemented groups. After the pathogenicity test, the survival rate of Y17 + and G11 + V. parahaemolyticus groups was 66.67% and 80.00%, respectively, compared with 53.33% for the control groups. Taken together, dietary supplementation of Y17 and G11 strains were beneficial in mud crab, which could increase growth performance, modulate immune system and protect the host against V. parahaemolyticus infection.
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http://dx.doi.org/10.1016/j.fsi.2019.07.050DOI Listing
October 2019

Scavenging of Acrolein by Food-Grade Antioxidant Propyl Gallate in a Model Reaction System and Cakes.

J Agric Food Chem 2019 Aug 29;67(31):8520-8526. Epub 2019 Jul 29.

Department of Food Science and Technology, School of Food Science and Pharmaceutical Engineering , Nanjing Normal University , 2 Xuelin Road , Nanjing , Jiangsu 210023 , People's Republic of China.

Reactive carbonyl species (RCS), such as acrolein (ACR), glyoxal (GO), and methylglyoxal (MGO), have received extensive attention recently as a result of their high activity and toxicity and . In the present study, propyl gallate (PG), a common food antioxidant, was found to effectively trap more ACR than butylated hydroxytoluene and butylated hydroxyanisole through the formation of mono-ACR adducts (PG-ACR) and di-ACR adducts (PG-2ACR). The two adducts were successfully purified, and their structures were elucidated on the basis of their high-resolution mass spectrometry and H, C, and two-dimensional nuclear magnetic resonance data. We further identified that PG-ACR had the ability to continue to trap GO and MGO to form PG-ACR-GO and PG-ACR-MGO, respectively, by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Furthermore, we verified that PG could inhibit the production of ACR, GO, and MGO via trapping these RCS simultaneously to form the corresponding adducts in pound cakes using LC-MS/MS.
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http://dx.doi.org/10.1021/acs.jafc.9b03486DOI Listing
August 2019

Stimulation of the class-A scavenger receptor induces neutrophil extracellular traps (NETs) by ERK dependent NOX2 and ROMO1 activation.

Biochem Biophys Res Commun 2019 04 6;511(4):847-854. Epub 2019 Mar 6.

Medical Research Center, Southwest Hospital, Army Military Medical University, Chongqing, 400038, China. Electronic address:

Neutrophil extracellular traps (NETs) play a critical role in host antimicrobial response whereas they are also implicated in the pathogenesis of inflammatory and autoimmunediseases. Generation of reactiveoxygen species (ROS) is key to NETs formation. A variety of stimulatory ligands have been found to enhance ROS production and thus trigger NETs. However, the mechanisms that connect receptor stimuli with ROS production and NETs formation remain unclear. In this study, we described a new mechanism of NETs generation in neutrophils triggered by stimulation of the class A scavenger receptor (SRA), a major subtype of scavenger receptors in response to various stimuli during infection and inflammatory disorders. By using polyinosinic acid (Poly I), a ribonucleotide ligand of SRA, we demonstrated that SRA stimulation lead to selective ERK phosphorylation, which upregulated cytosol ROS levels and induced canonical NETs formation by activating NADPH oxidase 2 (NOX2). Interestingly, our results showed that mitochondrial ROS (mtROS) production was also enhanced by the SRA dependent ERK activation through upregulation and activation of reactive oxygen species modulator 1(ROMO1), a mitochondrial membrane protein and a key mediator of mtROS. Moreover, inhibition of the SRA elicited ROMO1 activation dampened NETs release upon SRA stimulation. Overall, our study describes a new insight into the NETs release triggered by membrane SRA stimulation and mediated by ERK dependent NOX2 and ROMO1 activation.
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http://dx.doi.org/10.1016/j.bbrc.2019.02.142DOI Listing
April 2019

Trapping of glyoxal by propyl, octyl and dodecyl gallates and their mono-glyoxal adducts.

Food Chem 2018 Dec 4;269:396-403. Epub 2018 Jul 4.

Department of Food Science and Technology, Nanjing Normal University, 122# Ninghai Road, Nanjing 210097, PR China. Electronic address:

Glyoxal (GO) is one of the major toxic intermediates generated during lipid oxidation and degradation. We investigated the inhibitory activities and mechanisms of propyl, octyl, and dodecyl gallates (PG, OG, and DG) on the formation of GO in buffer and during thermo-processing of corn oil, and the anti-carbonyl and antioxidative activities of the mono-GO adducts of PG, OG, and DG. Our results suggested that alkyl gallates could more effectively trap GO than gallic acid. The major mono-GO adducts of PG, OG, and DG were purified and their structures were elucidated based on their H, C, 2D-NMR, and HRMS data. We further demonstrated that the mono-GO (MG) adducts retained the anti-carbonyl and antioxidative activities. This is the first study to demonstrate that alkyl gallates, the popular food additives, could prevent not only food oxidation, but also the formation of toxic reactive carbonyl species and their corresponding advanced glycation end products (AGEs) during food processing.
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http://dx.doi.org/10.1016/j.foodchem.2018.07.030DOI Listing
December 2018

Dual effects of propyl gallate and its methylglyoxal adduct on carbonyl stress and oxidative stress.

Food Chem 2018 Nov 16;265:227-232. Epub 2018 Apr 16.

Department of Food Science and Technology, Nanjing Normal University, 122# Ninghai Road, Nanjing 210097, PR China. Electronic address:

In the present study, we investigated the trapping of methylglyoxal (MGO) by propyl gallate (PG), a known food grade antioxidant, and the anti-carbonyl and anti-oxidative properties of the mono-MGO adduct of PG (MM-PG). Our result indicated that more than 77.5% MGO was suppressed by PG after a 30 min incubation of PG with MGO, which was much more effective than gallic acid (15.2%). For the first time, MM-PG was purified, and its structure was elucidated based on the analysis of its H, C, and 2D-NMR data. We also demonstrated that MM-PG had strong anti-oxidative and anti-carbonyl activities. Furthermore, PG could trap the MGO generated during the preparation of roasted pork, and both mono- and di- MGO adducts of PG were detected in the roasted pork system using LC/MS technique. Thus, PG could be widely applied in the food system for inhibiting the formation of both carbonyl species and oxidative species.
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http://dx.doi.org/10.1016/j.foodchem.2018.04.045DOI Listing
November 2018

NADPH oxidase 2 inhibitor diphenyleneiodonium enhances ROS-independent bacterial phagocytosis in murine macrophages via activation of the calcium-mediated p38 MAPK signaling pathway.

Am J Transl Res 2017 15;9(7):3422-3432. Epub 2017 Jul 15.

Medical Research Center, Southwest Hospital, Third Military Medical UniversityChongqing, China.

Activation of NADPH oxidase 2 (NOX2) triggers reactive oxygen species (ROS) generation, both of which are essential for robust microbial clearance by phagocytes. However, it is unknown whether inhibition of NOX2 activation or ROS generation affects cellular phagocytosis. Here, we found that the classic NOX2 inhibitor diphenyleneiodonium (DPI) induced uptake of by murine peritoneal macrophages through enhancing phagocytosis, and this effect was temperature-sensitive and attenuated by cytochalasin D as well as chemical inhibition of Syk and PLCγ, two downstream kinases involved in actin polymerization during phagocytosis. DPI also decreased the production of TNF-α and IL-6 resulting from stimulation. The DPI-induced enhancement of phagocytosis was independent of NOX2 inhibition or ROS generation but depended on increased intracellular calcium and activation of the p38 MAPK signaling pathway. Furthermore, DPI enhanced bacterial elimination and ameliorated inflammation in -infected mice, leading to improved survival. Our results demonstrate that DPI facilitates ROS-independent bacterial phagocytosis by macrophages through activation of calcium and p38 MAPK signaling pathways.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5527256PMC
July 2017

Levels and formation of α-dicarbonyl compounds in beverages and the preventive effects of flavonoids.

J Food Sci Technol 2017 Jun 27;54(7):2030-2040. Epub 2017 Apr 27.

Department of Food Science and Technology, Nanjing Normal University, 122# Ninghai Road, Nanjing, 210097 People's Republic of China.

Abstract: Methylglyoxal (MGO) and glyoxal (GO), α-dicarbonyl compounds found in the Maillard reaction, progressively and irreversibly modify proteins. Beverages are an exogenous source of α-dicarbonyl compounds and may potentially increase MGO and GO levels in vivo. Using GC-FID method, we detected the MGO and GO contents of 86 beverages in Chinese supermarkets. The highest MGO and GO 587.5 µg/100 mL and 716.7 µg/100 mL respectively found in soyamilk and coffee. Herbal beverages, which contained bioactive components, had lower average levels of MGO (48.1 µg/100 mL) and GO (25.9 µg/100 mL). A box-and-whisker plot was used to display variation of the same group drinks, and comparing distributions between six different groups. It was further discovered that fat, protein and flavonoids, in addition to sweeteners, had notable effects on the formation of MGO and GO in soybean milk. The result of LC/MS indicated that quercetin could prevent the formation of MGO by trapping MGO to form the mono-MGO and di-MGO adducts during soybean milk manufacturing.

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http://dx.doi.org/10.1007/s13197-017-2639-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5495730PMC
June 2017

The Antimalarial Chloroquine Suppresses LPS-Induced NLRP3 Inflammasome Activation and Confers Protection against Murine Endotoxic Shock.

Mediators Inflamm 2017 22;2017:6543237. Epub 2017 Feb 22.

Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.

Activation of the NLRP3 inflammasome, which catalyzes maturation of proinflammatory cytokines like IL-1 and IL-18, is implicated and essentially involved in many kinds of inflammatory disorders. Chloroquine (CQ) is a traditional antimalarial drug and also possesses an anti-inflammatory property. In this study, we investigated whether CQ suppresses NLRP3 inflammasome activation and thereby confers protection against murine endotoxic shock. CQ attenuated NF-B and MAPK activation and prohibited expression of IL-1, IL-18, and in LPS treated murine bone marrow-derived macrophages (BMDMs), demonstrating its inhibitory effect on the priming signal of NLRP3 activation. Then, CQ was shown to inhibit caspase-1 activation and ASC specks formation in BMDMs, which indicates that CQ also suppresses inflammasome assembly, the second signal for NLRP3 inflammasome activation. In a murine endotoxic shock model, CQ effectively improved survival and markedly reduced IL-1 and IL-18 production in serum, peritoneal fluid, and lung tissues. Moreover, CQ reduced protein levels of NLRP3 and caspases-1 p10 in lung homogenates of mice with endotoxic shock, which may possibly explain its anti-inflammatory activity and life protection efficacy in vivo. Overall, our results demonstrate a new role of CQ that facilitates negative regulation on NLRP3 inflammasome, which thereby confers protection against lethal endotoxic shock.
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http://dx.doi.org/10.1155/2017/6543237DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5340938PMC
June 2017

Influence of Quercetin and Its Methylglyoxal Adducts on the Formation of α-Dicarbonyl Compounds in a Lysine/Glucose Model System.

J Agric Food Chem 2017 Mar 6;65(10):2233-2239. Epub 2017 Mar 6.

Department of Food Science and Technology, Nanjing Normal University , 122 Ninghai Road, Nanjing 210097, People's Republic of China.

Increasing evidence has identified α-dicarbonyl compounds, the reactive intermediates generated during Maillard reaction, as the potential factors to cause protein glycation and the development of chronic diseases. Therefore, there is an urgent need to decrease the levels of reactive dicarbonyl compounds in foods. In this study, we investigated the inhibitory effect of quercetin, a major dietary flavonoid, and its major mono- and di-MGO adducts on the formation of dicarbonyl compounds, such as methylglyoxal (MGO) and glyoxal (GO), in a lysine/glucose aqueous system, a model system to reflect the Maillard reaction in food process. Our result indicated that quercetin could efficiently inhibit the formation of MGO and GO in a time-dependent manner. Further mechanistic study was conducted by monitoring the formation of quercetin oxidation and conjugation products using LC-MS/MS. Quercetin MGO adducts, quercetin quinones, and the quinones of quercetin MGO adducts were detected in the system, indicating quercetin plays a dual role in inhibiting the formation of MGO and GO by scavenging free radicals generated in the system and trapping of MGO and GO to form MGO adducts. In addition, we prepared the mono- and di-MGO quercetin adducts and investigated their antioxidant activity and trapping capacity of MGO and GO. Our results indicated that both mono- and di-MGO quercetin adducts could scavenge the DPPH radical in a dose-dependent manner with >40% DPPH scavenged by the MGO adducts at 10 μM, and the di-MGO quercetin adduct could further trap MGO to generate tri-MGO adducts. Therefore, we demonstrate for the first time that quercetin MGO adducts retain the antioxidant activity and trapping capacity of reactive dicarbonyl species.
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http://dx.doi.org/10.1021/acs.jafc.6b05811DOI Listing
March 2017

The citrus flavonoid naringenin confers protection in a murine endotoxaemia model through AMPK-ATF3-dependent negative regulation of the TLR4 signalling pathway.

Sci Rep 2016 12 22;6:39735. Epub 2016 Dec 22.

Medical Research Center, Southwest Hospital, the Third Military Medical University, Chongqing, 400038, China.

Excessive activation of the TLR4 signalling pathway is critical for inflammation-associated disorders, while negative regulators play key roles in restraining TLR4 from over-activation. Naringenin is a citrus flavonoid with remarkable anti-inflammatory activity, but the mechanisms underlying its inhibition of LPS/TLR4 signalling are less clear. This study investigated the molecular targets and therapeutic effects of naringenin in vitro and in vivo. In LPS-stimulated murine macrophages, naringenin suppressed the expression of TNF-α, IL-6, TLR4, inducible NO synthase (iNOS), cyclo-oxygenase-2 (COX2) and NADPH oxidase-2 (NOX2). Naringenin also inhibited NF-κB and mitogen-activated protein kinase (MAPK) activation. However, it did not affect the IRF3 signalling pathway or interferon production, which upregulate activating transcription factor 3 (ATF3), an inducible negative regulator of TLR4 signalling. Naringenin was demonstrated to directly increase ATF3 expression. Inhibition of AMPK and its upstream calcium-dependent signalling reduced ATF3 expression and dampened the anti-inflammatory activity of naringenin. In murine endotoxaemia models, naringenin ameliorated pro-inflammatory reactions and improved survival. Furthermore, it induced AMPK activation in lung tissues, which was required for ATF3 upregulation and the enhanced anti-inflammatory activity. Overall, this study reveals a novel mechanism of naringenin through AMPK-ATF3-dependent negative regulation of the LPS/TLR4 signalling pathway, which thereby confers protection against murine endotoxaemia.
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http://dx.doi.org/10.1038/srep39735DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5177915PMC
December 2016

Kukoamine B promotes TLR4-independent lipopolysaccharide uptake in murine hepatocytes.

Oncotarget 2016 09;7(36):57498-57513

Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing, China.

Free bacterial lipopolysaccharide (LPS) is generally removed from the bloodstream through hepatic uptake via TLR4, the LPS pattern recognition receptor, but mechanisms for internalization and clearance of conjugated LPS are less clear. Kukoamine B (KB) is a novel cationic alkaloid that interferes with LPS binding to TLR4. In this study, KB accelerated blood clearance of LPS. KB also enhanced LPS distribution in the hepatic tissues of C57 BL/6 mice, along with LPS uptake in primary hepatocytes and HepG2 cells. By contrast, KB inhibited LPS internalization in Kupffer and RAW 264.7 cells. Loss of TLR4 did not affect LPS uptake into KB-treated hepatocytes. We also detected selective upregulation of the asialoglycoprotein receptor (ASGPR) upon KB treatment, and ASGPR colocalized with KB in cultured hepatocytes. Molecular docking showed that KB bound to ASGPR in a manner similar to GalNAc, a known ASGPR agonist. GalNAc dose-dependently reduced KB internalization, suggesting it competes with KB for ASGPR binding, and ASGPR knockdown also impaired LPS uptake into hepatocytes. Finally, while KB enhanced LPS uptake, it was protective against LPS-induced inflammation and hepatocyte injury. Our study provides a new mechanism for conjugated LPS hepatic uptake induced by the LPS neutralizer KB and mediated by membrane ASGPR binding.
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http://dx.doi.org/10.18632/oncotarget.11292DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5295368PMC
September 2016

Consistency and pathophysiological characterization of a rat polymicrobial sepsis model via the improved cecal ligation and puncture surgery.

Int Immunopharmacol 2016 Mar 21;32:66-75. Epub 2016 Jan 21.

Medical Research Center, Southwest Hospital, the Third Military Medical University, Chongqing, 400038, PR China. Electronic address:

Sepsis is the leading cause of death for critical ill patients and an essential focus in immunopharmacological research. The cecal ligation and puncture (CLP) model is regarded as a golden standard model for sepsis study. However, this animal model is easily affected by variability problems and dramatically affects pharmacological evaluation of anti-sepsis therapies, which requires standardized procedures and stable outcomes. Herein, the traditional syringe needle based puncture method was used as the major unstable factor for CLP models. Syringe needles created varied mortality in parallel experimental groups of CLP rats; they were inconsistent for severity control as mortality in CLP rats was not correlated with change in punctures, ligation lengths, or needle sizes. Moreover, the use of drainage tubes or strips, which was supposed to strengthen drainage stability, also failed to improve consistency of traditional syringe needles. To solve the consistency problem, an improved design of CLP surgery by puncture with newly-developed three-edged needles was described herein. In contrast to traditional syringe needles, these three-edged needles ensured more stable outcomes in repetitive groups. Furthermore, increased severity was found to be consistent with the enlarged needle size, as shown by the elevated mortality, increased proinflammatory cytokines, abnormal coagulation, worsen acidosis and more severe acute lung injury. In conclusion, application of the newly-developed three-edged needles provides a simple and feasible method to improve stability when conducting CLP surgery, which is significant for pharmacological studies on sepsis.
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http://dx.doi.org/10.1016/j.intimp.2015.12.041DOI Listing
March 2016

Inhibition of clathrin/dynamin-dependent internalization interferes with LPS-mediated TRAM-TRIF-dependent signaling pathway.

Cell Immunol 2012 2;274(1-2):121-9. Epub 2012 Jan 2.

Medical Research Center, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China.

Recognition of lipopolysaccharide (LPS) by Toll-like receptor 4 (TLR4) activates two district proinflammatory signaling pathway and initiates LPS internalization. To investigate roles of LPS internalization, a traditionally regarded metabolic pathway for LPS, in regulation of these two pathways, three internalization inhibitors, monodansylcadaverine (MDC, a clathrin inhibitor), dynasore (DS, a dynamin inhibitor) and chloroquine (CQ, an endosome acidifying maturation inhibitor) were applied to induce internalization dysfunction in macrophages. Results showed MDC and DS affected LPS internalization but did not interfere with their colocalization. Additionally, they decreased cytokines and chemokines release and inhibited signaling molecules activation mediated by TRAM-TRIF-dependent pathway as determined by protein array. In contrast, CQ did not inhibit LPS internalization but affected the colocalization. It also suppressed macrophage activation mediated by both MyD88-dependent and TRAM-TRIF-dependent pathways. The above data indicated that LPS internalization was clathrin/dynamin dependent and it was essential for activation of TRAM-TRIF-dependent signaling pathway.
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http://dx.doi.org/10.1016/j.cellimm.2011.12.007DOI Listing
June 2012