Bt Cry toxin is the mostly studied and widely used biological insect resistance protein, which plays a leading role in the green control of agricultural pests worldwide. However, with the wide application of its preparations and transgenic insecticidal crops, the resistance to target pests and potential ecological risks induced by the drive are increasingly prominent and attracting much attention. The researchers seek to explore new insecticidal protein materials that can simulate the insecticidal function of Bt Cry toxin. This will help to escort the sustainable and healthy production of crops, and relieve the pressure of target pests' resistance to Bt Cry toxin to a certain extent. In recent years, the author's team has proposed that Ab2β anti-idiotype antibody has the property of mimicking antigen structure and function based on the "Immune network theory" of antibody. With the help of phage display antibody library and specific antibody high-throughput screening and identification technology, Bt Cry toxin antibody was designed as the coating target antigen, and a series of Ab2β anti-idiotype antibodies (namely Bt Cry toxin insecticidal mimics) were screened from the phage antibody library. Among them, the lethality of Bt Cry toxin insecticidal mimics with the strongest activity was close to 80% of the corresponding original Bt Cry toxin, showing great promise for the targeted design of Bt Cry toxin insecticidal mimics. This paper systematically summarized the theoretical basis, technical conditions, research status, and discussed the development trend of relevant technologies and how to promote the application of existing achievements, aiming to facilitate the research and development of green insect-resistant materials.
Insecticides/metabolism* ; Bacillus thuringiensis ; Endotoxins/pharmacology* ; Bacillus thuringiensis Toxins/metabolism* ; Hemolysin Proteins/pharmacology* ; Bacterial Proteins/chemistry* ; Plants, Genetically Modified/genetics* ; Pest Control, Biological

Bacillus thuringiensis is widely used as an insecticide which is safe and environmentally friendly to humans and animals. One of the important insecticidal mechanisms is the binding of Bt toxins to specific toxin receptors in insect midgut and forming a toxin perforation which eventually leads to insect death. The resistance of target pests to Bt toxins is an important factor hampering the long-term effective cultivation of Bt crops and the continuous use of Bt toxins. This review summarizes the mechanism of insect resistance to Bt toxins from the perspective of important Bt toxin receptors in midgut cells of Lepidopteran insects, which may facilitate the in-depth study of Bt resistance mechanism and pest control.
Animals ; Bacillus thuringiensis/genetics* ; Bacillus thuringiensis Toxins ; Bacterial Proteins/metabolism* ; Endotoxins/metabolism* ; Hemolysin Proteins/metabolism* ; Insecta/metabolism* ; Insecticide Resistance/genetics* ; Insecticides/pharmacology* ; Pest Control, Biological

OBJECTIVETo explore the effect of Compound Tongtu Granule (CTG) on intestinal permeability in elderly sepsis patients.

METHODSEighty elderly sepsis patients were randomly assigned to the experimental group and the control group by randomized double blinded method, 40 in each group. On the basis of conventional antiseptic treatment program, patients in the experimental group took CTG, while those in the control group took placebos. The dosage for CTG or placebos was 14.3 g each package, one package each time, twice daily for 14 successive days. Patients' abdominal symptoms and signs, levels of serum inflammatory factors (high-sensitivity C-reactive protein and procalcitonin), levels of plasma endotoxin, and the intestinal permeability (IP, represented by urinary lactulose/mannitol excretion rate) were compared between the two groups before and after treatment.

RESULTSAfter 14-day treatment, patients in the experimental group had improved abdominal symptoms, increased frequency of defecation, significantly decreased levels of plasma endotoxin and IP, when compared with the control group (P < 0.05).

CONCLUSIONCTG could improve the intestinal barrier function in elderly sepsis patients.

Aged ; C-Reactive Protein ; metabolism ; Calcitonin ; metabolism ; Calcitonin Gene-Related Peptide ; Defecation ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Endotoxins ; metabolism ; Humans ; Intestines ; metabolism ; Permeability ; Protein Precursors ; metabolism ; Sepsis ; drug therapy ; physiopathology

OBJECTIVETo investigate the effect of n-3 polyunsaturated fatty acids (n-3PUFAs) on gut microbiota and endotoxin levels in portal vein of rats fed with a high-fat diet (HFD).

METHODSThirty-six male Sprague-Dawley rats were randomly divided into four groups and fed with normal control diet (CD), HFD, CD supplemented with n-3PUFAs, and HFD supplemented with n-3PUFAs, respectively. Fresh fecal samples were collected to analyze the gut microbiota 10 weeks after feeding. DNA was exacted from the fresh fecal samples. Quantitative PCR was used to detect the composition of the gut microbiota. The endotoxin levels were detected through modified azo chromogenic substrate limulus amebocyte lysate assay.

RESULTSThe differences in body weight before breeding in each group were not statistically significant among these four groups (P=0.613). The increase in the body weight was significantly larger in the HFD group than in the CD group (P=0.0002), CD+n-3PUFAs group (P=0.0001), and HFD+n-3PUFAs group (P=0.022). There were significantly more firmicutes (P=0.002) and enterobacteriales (P=0.022) and significantly less bacteroidetes (P=0.026) and bifidobactera (P=0.034) in the gut of rats from HFD group than those from the CD group. There were significantly more bacteroidetes in the fecal samples of the rats from the CD+n-3PUFAs group compared to those from the CD group (P=0.043). There were significantly more firmicutes (P=0.044)and enterobacteriales (P=0.012) and less bacteroidetes (P=0.042) in the fecal samples of the rats from HFD group compared to those from the HFD+n-3PUFAs group. The endotoxin in plasma form portal vein of rats in HFD group were significantly higher than in CD group (P=0.007) and HFD+n-3PUFAs group (P=0.042) but showed no significant difference between CD+n-3PUFAs and CD group (P=0.210).

CONCLUSIONSHFD can increase body weight and change gut microbiota. Supplementation of n-3PUFAs can partially counteract such gut dysbiosis, lower endotoxin level in portal vein blood, and improve the body weight.

Animals ; Body Weight ; Diet, High-Fat ; adverse effects ; Endotoxins ; blood ; Fatty Acids, Omega-3 ; pharmacology ; Intestines ; microbiology ; Male ; Microbiota ; drug effects ; Portal Vein ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effects of different concentrations of lipopolysaccharide (LPS) on proliferation and apoptosis of human umbilical cord mesenchymal stem cells (hUCMSCs) in vitro, and to explore their possible mechanism.

METHODShUCMSCs from umbilical cord tissue of full-term healthy fetus delivered by caesarean section were isolated and cultured in vitro using tissue attachment method. The 3rd passage hUCMSCs were used in the study. Cells were divided into groups A, B, C, D, and E, which were treated with DMEM/F12 medium containing 0, 0.1, 1.0, 10.0, and 100.0 µg/mL of LPS respectively. In groups B, C, D, and E, methyl-thiazole-tetrazolium assay was used to detect proliferative activity of hUCMSCs at post treatment hour (PTH) 12, 24, and 48 (denoted as absorption value), with 5 samples in each group at each time point; apoptosis of hUCMSCs at PBH 24 was identified with acridine orange-ethidium bromide (AO-EB) staining, with 4 samples in each group; apoptotic rate of hUCMSCs was determined by flow cytometer, with 5 samples in each group. Above-mentioned indexes were determined in group A at the same time points. Data were processed with analysis of variance and LSD- t test.

RESULTS(1) There was no statistically significant difference in proliferative activity of hUCMSCs at PTH 12 among groups A, B, C, D, and E (with t values from -1.67 to 1.33, P values above 0.05). Compared with that of group A, proliferative activity of hUCMSCs was increased in groups B, C, and D at PTH 24 and 48 (with t values from -13.42 to 17.34, P < 0.05 or P < 0.01), especially so in group C. Proliferative activity of hUCMSCs was lower in group E at PTH 24 and 48 than in group A (with t values respectively 8.64 and 17.34, P values below 0.01). (2) Obvious apoptosis of hUCMSCs was observed in group E but not in the other 4 groups with AO-EB staining. (3) Apoptosis rates of hUCMSCs in groups A, B, C, D, and E were respectively (3.1 ± 0.6)%, (2.6 ± 0.7)%, (2.9 ± 0.8)%, (3.1 ± 0.4)%, (25.1 ± 2.7)% (F = 272.19, P < 0.01). Apoptotic rate of hUCMSCs in group B, C, or D was respectively close to that in group A (with t values respectively 1.22, 0.57, -0.14, P values above 0.05), but it was higher in group E than in group A (t = -17.63, P < 0.01).

CONCLUSIONShUCMSCs proliferation may be promoted by low concentration of LPS. hUCMSCs proliferation is inhibited or induced to apoptosis along with the increase in concentration of LPS, and it may be related to activation of different major molecular signaling pathways by different concentrations of LPS.

Apoptosis ; drug effects ; Cell Proliferation ; Endotoxins ; adverse effects ; Humans ; Lipopolysaccharides ; pharmacology ; Membrane Proteins ; Mesenchymal Stromal Cells ; cytology ; drug effects ; Signal Transduction ; Umbilical Cord ; cytology

OBJECTIVETo explore the mechanism of tanshinol on alleviate the inflammatory injury of lung tissue in rat hepatopulmonary syndrome (HPS).

METHODSSD rats were randomly divided into normal control group (n = 8), hepatopulmonary syndrome (HPS) group (n = 11) and tanshinol intervention group (n = 9). HE staining was used to observe the histopathology changes of pulmonary and hepatic tissues, and to count the number of macrophages in lung tissues. The activity of alanine transferase (ALT) and concentrations of endotoxin, tumor necrosis factor-a (TNF-alpha) and homocystein (Hcy) in plasma were detected. The concentrations of TNF-alpha, nitric oxide (NO) and malondialdehyde (MDA) and the activity of inducible nitric oxide synthase (iNOS) in the lung tissues were measured, respectively.

RESULTSThickened alveolar septum and increased macrophages were observed in lungs in HPS rat. After administered with tanshinol, the pulmonary pathological changes were alleviated and the number of macrophages in lung tissue was decreased compared with HPS group. The activity of ALT and the concentrations of endotoxin, TNF-alpha and Hcy in plasma ,and TNF-alpha, iNOS, NO and MDA in lung tissue in HPS group were higher than those of normal control group; meanwhile, those tanshinol group were less those that of HPS group.

CONCLUSIONTanshinol may play an important role in delaying the development of HPS through protecting liver or directly antagonizing the effect of intestinal endotoxemia so as to alleviate the inflammatory reaction in lung tissue.

Alanine Transaminase ; metabolism ; Animals ; Caffeic Acids ; pharmacology ; Disease Models, Animal ; Endotoxins ; blood ; Hepatopulmonary Syndrome ; drug therapy ; pathology ; Homocysteine ; blood ; Liver ; drug effects ; pathology ; Lung ; drug effects ; pathology ; Macrophages ; drug effects ; pathology ; Male ; Malondialdehyde ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha ; blood

The protective effect of erythropoietin (EPO) on tissues following ischemia and reperfusion injuries remains poorly understood. We aimed to investigate the effect of EPO in preventing endotoxin-induced organ damage. Rat model of multiple organ failure (MOF) was established by tail vein injection of 10 mg/kg lipopolysaccharide (LPS). Recombinant human EPO treatment (5000 U/kg) was administered by tail vein injection at 30 min after LPS challenge. Twenty-four h after EPO treatment, changes in serum enzyme levels, including aspartate aminotransferase (AST), alanine transaminase (ALT), blood urea nitrogen (BUN) and creatinine (Cr), were evaluated by biochemical analysis. Serum levels of tumor necrosis factor-α (TNF-α) were determined by using immunoradiometric assay. Histological examination of tissue sections was carried out by hematoxylin and eosin staining, while ultrastructure evaluation of organ tissues was assessed by transmission electron microscopy. Protein expression levels were detected by using Western blotting. EPO treatment showed a modest effect in preventing LPS-induced elevation of AST, ALT, BUN, Cr, and TNF-α levels, and in protecting against LPS-induced tissue degeneration and injured ultrastructure in the lung, liver, and kidney. Moreover, LPS promoted phosphorylation of alanine aminotransferase (AKT) and increased nuclear factor-κB (NF-κB) activation in the lung, liver, and kidney (P<0.05 vs. control). However, EPO treatment significantly decreased the LPS-induced pAKT up-regulation in these tissues (P<0.05 vs. LPS treatment alone). The present study demonstrates that EPO may play a protective role against LPS-induced MOF by reducing the inflammatory response and tissue degeneration, possibly via the phosphatidylinositol 3-kinase/AKT and NF-κB signaling pathways.
Alanine Transaminase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Blood Urea Nitrogen ; Blotting, Western ; Creatinine ; blood ; Endotoxins ; Erythropoietin ; administration & dosage ; genetics ; pharmacology ; Injections, Intravenous ; Kidney ; drug effects ; metabolism ; ultrastructure ; Lipopolysaccharides ; Liver ; drug effects ; metabolism ; ultrastructure ; Lung ; drug effects ; metabolism ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; Multiple Organ Failure ; blood ; chemically induced ; prevention & control ; NF-kappa B ; metabolism ; Phosphorylation ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Wistar ; Recombinant Proteins ; administration & dosage ; pharmacology ; Tumor Necrosis Factor-alpha ; blood

Nine mutants (P2M1-9) were obtained using PCR with 5-BU based on DNA template (P2Y) encoding the active region of Parasporin-2. Mutant proteins were purified after expressing in E. coli BL21 cells, followed by assayed against hepatoma cells and normal liver cells by MTT. They showed diverse anti-hepatoma activities, in which two mutant proteins, P2M1 and P2M8, exhibited high cytotoxicity against hepatoma cell lines SMMC7721 and Be17402, meanwhile leaving normal liver cells Chang-liver unaffected. Structural comparison among P2Y, P2M1 and P2M8 showed that the length of beta-sheet or beta-fold, and the amount of alpha helix greatly affected the anti-hepatoma activity of Parasporin-2. Results based on amino acid alignment, molecular docking between P2Y, P2M1 or P2M8 and receptor, and mimic mutation demonstrated that amino acid residues at the sites of 52, 56, 58 and 208 on P2Y, especially the aromatic amino acids such as Trp, Phe, and Tyr were involved in the interactions.
Amino Acid Sequence ; Amino Acids, Aromatic ; biosynthesis ; genetics ; pharmacology ; Antineoplastic Agents ; pharmacology ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Endotoxins ; chemistry ; pharmacology ; Escherichia coli ; genetics ; metabolism ; Humans ; Liver Neoplasms ; pathology ; Molecular Sequence Data ; Mutant Proteins ; pharmacology ; Recombinant Proteins ; biosynthesis ; genetics ; pharmacology

In order to discover the mechanism of Xuebijing oral effervescent tablet (XBJOET) to treat infectious diseases, the effect of XBJOET on endotoxin induced rabbit fever and disseminated intravascular coagulation (DIC) was investigated. Auricle microcirculation in rabbit was detected by laser speckle blood perfusion imager system; coagulation function was measured by coagulation analyzer, fibrinolytic system was quantified by Elisa assay and micro thrombosis in tissues was observed with HE staining under light microscope. The results demonstrated that the body temperature of rabbit decreased significantly at 1-3 h after administration with 4.8, 2.4 and 1.2 g x kg(-1) XBJOET to endotoxin induced DIC rabbit model, the auricle microcirculation blood flow in model group (54.45 +/- 14.53) PU was lower than that in control group (77.18 +/- 12.32) PU. The auricle microcirculation blood flow increased markedly and there was significant difference between model group and 1.2 g x kg(-1) XBJOET group. There was significant difference between model group and control group in the content of PAI1 and FIB. The PAI1 levels in model and control groups were (30.48 +/- 2.46) ng x mL(-1) and (20.93 +/- 3.25) ng x mL(-1), respectively. The FIB levels in model and control group were (3.34 +/- 1.09) g x L(-1) and (4.84 +/- 1.10) g x L(-1), respectively. The content of PAI1 in rabbit plasma decreased notably, there were significant differences between model group and 4.8, 2.4 g x kg(-1) XBJOET groups. On the contrary the content of FIB increased. XBJOET possessed pharmacological activities of curing infectious fever and DIC, the mechanism of which is related to amelioration of microcirculation disturbance, inhibition of fibrinolytic system activation and coagulation and micro thrombosis elimination.
Administration, Oral ; Animals ; Blood Coagulation ; drug effects ; Body Temperature ; drug effects ; Disseminated Intravascular Coagulation ; blood ; chemically induced ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Ear Auricle ; blood supply ; Endotoxins ; Female ; Fever ; chemically induced ; drug therapy ; physiopathology ; Fibrinogen ; metabolism ; Male ; Microcirculation ; Partial Thromboplastin Time ; Plasminogen Activator Inhibitor 1 ; blood ; Prothrombin Time ; Rabbits ; Tablets ; Thrombosis ; pathology

OBJECTIVETo investigate the theoretical model of the three-dimensional structure of mosquitocidal Cry30Ca2 and its molecular docking with N-acetylgalactosamine.

METHODSThe theoretical model of Cry30Ca2 was predicted by homology modeling on the structure of the Cry4Ba. Docking studies were performed to investigate the interaction of Cry30Ca2 with N-acetylgalactosamine on the putative receptor.

RESULTSCry30Ca2 toxin is a rather compact molecule composed of three distinct domains and has approximate overall dimensions of 95 by 75 by 60Å. Domain II is a helix bundle, Domain II consists of three antiparallel β-sheets, Domain III is composed of two β-sheets that adopt a β-sandwich fold. Residue 321Ile in loop1, residues 342Gln 343Thr and 345Gln in loop2, residue 393Tyr in loop3 of Cry30Ca2 are responsible for the interactions with GalNAc via 7 hydrogen bonds, 6 of them were related to the oxygen atoms of hydroxyls of the ligand, and one to the nitrogen of the ligand.

CONCLUSIONThe 3D structure of Cry30Ca2 resembles the previously reported Cry toxin structures but shows still some distinctions. Several residues in the loops of the apex of domain II are responsible for the interactions with N-acetylgalactosamine.

Acetylgalactosamine ; chemistry ; Amino Acid Sequence ; Animals ; Bacterial Proteins ; chemistry ; pharmacology ; Catalytic Domain ; Culicidae ; drug effects ; Endotoxins ; chemistry ; pharmacology ; Hemolysin Proteins ; chemistry ; pharmacology ; Insecticides ; chemistry ; pharmacology ; Models, Molecular ; Molecular Sequence Data ; Protein Conformation