Abnormal Circadian Clock Ｐromotes AOM / DSS-induced Colon Carcinogenesis in Mice by Remodeling Tumor Metabolism / 中国生物化学与分子生物学报

Abnormal circadian clock has been identified as an independent risk factor for tumorigenesis, and is closely related to the occurrence and development of tumor. As metabolic disorder is also one of the important characteristics of tumorigenesis, therefore it is particularly important to investigate the regulatory relationship between biological clock and tumor metabolism. In this study, the effect of abnormal circadian clock on colon cancer growth was evaluated by azoxymethane (AOM) / dextran sodium sulfate (DSS) -induced colitis-associated carcinogenesis (CAC) mice model. The result showed that abnormal circadian clock aggravated anal swelling, redness, bloody and anorectal prolapse in CAC mice, and significantly increased the number and volume of CAC polyps (P <0. 05 or P <0. 01), and reduced the intestinal length, body weight, survival rate of CAC mice and the expression levels of inflammatory factors IL-1β (interleukin-1 beta) and TNFα (tumor necrosis factor α) (P < 0. 05 or P < 0. 01), indicating that abnormal biological clock promotes the occurrence and development of CAC. Further, non-target metabonomics analysis of serum samples from mice was performed by liquid chromatography-mass spectrometry (LC-MS) . The result showed that compared with CAC mice with normal circadian rhythm, 27 differential metabolites were identified in CAC mice with disrupted circadian clock, and 9 metabolic pathways were enriched by KEGG (kyoto encyclopedia of genes and genomes) database. These results suggest that abnormal circadian clock can significantly change the relative abundance of some metabolites in serum samples from CAC mice, remodel tumor metabolism, and result in the development of CAC in mice. This study reveals the pivotal role of tumor metabolism in the abnormal circadian clock promoting the growth of CAC in mice, providing a new experimental basis for the interaction between circadian clock and metabolic homeostasis in the occurrence and development of colon cancer.

Characterization of the active fragments of Spodoptera litura Lebocin-1.

Insects can produce various antimicrobial peptides (AMPs) upon immune stimulation. One class of AMPs are characterized by their high proline content in certain fragments. They are generally called proline-rich antimicrobial peptides (PrAMPs). We previously reported the characterization of Spodoptera litura lebocin-1 (SlLeb-1), a PrAMP proprotein. Preliminary studies with synthetic polypeptides showed that among the four deductive active fragments, the C-terminal fragment SlLeb-1 (124-158) showed strong antibacterial activities. Here, we further characterized the antibacterial and antifungal activities of 124-158 and its four subfragments: 124-155, 124-149, 127-158, and 135-158. Only 124-158 and 127-158 could agglutinate bacteria, while 124-158 and four subfragments all could agglutinate Beauveria bassiana spores. Confocal microscopy showed that fluorescent peptides were located on the microbial surface. Fragment 135-158 lost activity completely against Escherichia coli and Staphylococcus aureus, and partially against Bacillus subtilis. Only 124-149 showed low activity against Serratia marcescens. Negative staining, transmission, and scanning electron microscopy of 124-158 treated bacteria showed different morphologies. Flow cytometry analysis of S. aureus showed that 124-158 and four subfragments changed bacterial subpopulations and caused an increase of DNA content. These results indicate that active fragments of SlLeb-1 may have diverse antimicrobial effects against different microbes. This study may provide an insight into the development of novel antimicrobial agents.

Antimicrobial activities of a proline-rich proprotein from Spodoptera litura.

Antimicrobial peptides (AMPs) are produced by the stimulated humoral immune system. Most mature AMPs contain less than 50 amino acid residues. Some of them are generated from proproteins upon microbial challenges. Here, we report the antimicrobial activities of a proline-rich proprotein, named SlLebocin1 (SlLeb1), from the tobacco cutworm Spodoptera litura. SlLebocin1 cDNA contains a 477-bp open reading frame (ORF). It is mainly expressed in hemocytes and the midgut in naïve larvae. The transcript level was significantly induced in hemocytes but repressed in the midgut and fat body by bacterial challenges. The proprotein contains 158 amino acids with 3 RXXR motifs that are characteristic of some Lepidopteral lebocin proproteins. Four peptides corresponding to the predicted processed fragments were synthesized chemically, and their antimicrobial activities against two Gram-negative and two Gram-positive bacterial strains were analyzed. The peptides showed differential antimicrobial activities. For Escherichia coli and Bacillus subtilis, only the C-terminal fragment (124-158) showed strong inhibitory effects. For Staphylococcus aureus, all peptides showed partial inhibitions. None of them inhibited Serratia marcescens. Bacterial morphologies were examined by the scanning electron microscopy and confocal laser scanning microscopy. The antimicrobial peptides either disrupted cellular membrane or inhibited cell division and caused elongated/enlarged morphologies. The results may provide ideas for designing novel antibiotics.

Molecular Characterization of a Mitochondrial Manganese Superoxide Dismutase From Chilo suppressalis (Lepidoptera: Crambidae).

In insects, superoxide dismutases (SODs) play a critical role in the scavenging of harmful reactive oxygen species (ROS) and protecting against oxidative stress induced by various environmental stresses. The Asiatic rice borer, Chilo suppressalis (Walker) (Lepidoptera: Crambidae), is an economically important insect pest of rice crops. In this study, a mitochondrial manganese SOD (Cs-mMnSOD) gene was characterized in C. suppressalis. The deduced Cs-mMnSOD protein has typical highly conserved features of mitochondrial manganese SODs, including four manganese binding residues, the signature DVWEHAYY peptide, and a mitochondrial-targeting sequence at the N-terminus. Transcription of Cs-mMnSOD was detectable at all developmental stages, but highest in pupae. Furthermore, the mRNA level of Cs-mMnSOD was strongly upregulated (more than twofold increase) following exposure to low and high temperatures (4, 30 and 35°C), insecticides (chlorpyrifos and chlorantraniliprole), and chemical reagents (cumene hydroperoxide, paraquat, H2O2 and CdCl2), but slightly elevated (less than twofold increase) in response to 8°C, abamectin and CuSO4. Additionally, the Cs-mMnSOD transcription results were consistent with the enzymatic activity data of the protein product. Purified recombinant Cs-mMnSOD protein expressed in Escherichia coli displayed SOD activity and thermostability. Furthermore, E. coli cells overexpressing Cs-mMnSOD exhibited long-term resistance to the oxidative inducers cumene hydroperoxide and paraquat. Our findings indicate that Cs-mMnSOD plays an important role in protecting C. suppressalis against oxidative damage.

Application of Blink Reflex and Brainstem Auditory Evoked Potential in Brain Stem Function Evaluation of Patients with Consciousness Disorder / 中国康复理论与实践

@#Objective To explore the characteristics of blink reflex (BR) and brainstem auditory evoked potential (BAEP) in patients with consciousness disorder and the role of BR and BAEP in the evaluation of brain stem function. Methods From January to December, 2015, 31 patients with consciousness disorder were examined with BAEP, BR and Glasgow Coma Scale (GCS), and the outcome was record-ed one month after examination. Results BAEP and BR were positively related with GCS score (r≥0.562, P<0.05) and outcome (χ2=9.644, P<0.01). Conclusion Both BR and BAEP can reflect the brain stem function and respective pathway. Their combination could provide ob-jective basis for prognosis evaluation.

Application of Blink Reflex and Brainstem Auditory Evoked Potential in Brain Stem Function Evaluation of Patients with Consciousness Disorder / 中国康复理论与实践

@#Objective To explore the characteristics of blink reflex (BR) and brainstem auditory evoked potential (BAEP) in patients with consciousness disorder and the role of BR and BAEP in the evaluation of brain stem function. Methods From January to December, 2015, 31 patients with consciousness disorder were examined with BAEP, BR and Glasgow Coma Scale (GCS), and the outcome was record-ed one month after examination. Results BAEP and BR were positively related with GCS score (r≥0.562, P<0.05) and outcome (χ2=9.644, P<0.01). Conclusion Both BR and BAEP can reflect the brain stem function and respective pathway. Their combination could provide ob-jective basis for prognosis evaluation.

MG-132 enhances MSCs survival and IL-10 secretion under hypoxia and serum deprivation condition / 生理学报

Bone marrow-derived mesenchymal stem cells (MSCs) have emerged as attractive candidates for cellular therapies for heart and other organ-system disorders. However, a major dilemma in stem cell therapy for ischemic heart diseases is the low survival of transplanted cells in the ischemic and peri-infarcted region. In this study, MSCs were treated by hypoxia and serum deprivation (H/SD) to mimic the ischemic microenvironment of infarcted hearts where MSCs were transplanted. The effects of proteasome inhibitor MG-132 on H/SD-induced apoptosis and paracrine effects were investigated. Apoptosis of MSCs was detected by Annexin V-FITC flow cytometric analysis. Transcriptional levels of IL-1β, TNF-α and IL-10 were examined by real-time PCR. The nuclear translocation of NF-κBp65 was assessed by immunocytochemical staining. Translational changes of IL-1β and TNF-α were detected by Western blot. The secretion of IL-10 from MSCs was examined by ELISA assay. The results showed that MG-132 could effectively suppress H/SD-induced MSCs apoptosis. Furthermore, the induced IL-1β and TNF-α transcription was also inhibited by MG-132 treatment, which may be due to the inhibition of NF-κBp65 nuclear translocation by MG-132. Importantly, MG-132 effectively enhanced H/SD-induced transcription and secretion of IL-10, which is an important paracrine factor from MSCs. Our findings suggest that pretreatment of MSCs by MG-132 before cell transplantation may be an effective strategy to improve cell survival and enhance paracrine effects of MSCs.

Function and biological activities of the autotaxin-LPA axis / 生理学报

Autotaxin (ATX), a member of nucleotide pyrophosphatase/phosphodiesterase (NPP) family, is also named as phosphodiesterase Iα (PD-Iα) or NPP2. ATX is the unique member among the NPPs that can function as a lysophospholipase D (lysoPLD), converting lysophosphatidylcholine into lysophosphatidic acid (LPA). LPA acts on specific G-protein-coupled receptors to elicit a wide range of cellular response, including cell proliferation, cell migration and cell contraction, etc. As the major LPA-producing phospholipase, many ATX's features and functions are dependent on the production of LPA. ATX and LPA together form the ATX-LPA functional axis. The present review summarizes the current progress in function and biological activities of ATX-LPA axis.