BIOFILMS AND EXTRACTS FROM BACTERIA PRODUCING "QUORUM SENSING' SIGNALING MOLECULES PROMOTE CHEMOTAXIS AND SETTLEMENT BEHAVIORS IN Hydractinia Symbiolongicarpus (Cnidaria: Hydrozoa) LARVAE / Biopelículas y extractos de bacterias que producen moléculas de señalización de "Quorum Sensing' promueven comportamientos de quimiotaxis y asentamiento en larvas de Hydractinia symbiolongicarpus (Cnidaria: Hydrozoa)

ABSTRACT Many sessile marine invertebrates have life cycles involving the development of larvae that settle on specific substrates to initiate metamorphosis to juvenile forms. Although is recognized that bacterial biofilms play a role in this process, the responsible chemical cues are beginning to be investigated. Here, we tested the role of substrate-specific bacteria biofilms and their Quorum Sensing Signaling Molecule (QSSM) extracts on chemotaxis and settlement of larvae from Hydractinia symbiolongicarpus, a hydroid that grows on gastropod shells occupied by hermit crabs. We isolated and taxonomically identified by 16S rDNA sequencing, 14 bacterial strains from shells having H. symbiolongicarpus. Three isolates, Shigella flexneri, Microbacterium liquefaciens, and Kocuria erythromyxa, were identified to produce QSSMs using biosensors detecting N-acyl-L-homoserine lactones. Multispecies biofilms and QSSM extracts from these bacteria showed a positive chemotactic effect on H. symbiolongicarpus larvae, a phenomenon not observed with mutant strains of E. coli and Chromobacterium violaceum that are unable to produce QSSMs. These biofilms and QSSMs extracts induced high rates of larval attachment, although only 1 % of the attached larvae metamorphosed to primary polyps, in contrast to 99 % of larvae incubated with CsCl, an artificial inductor of attachment and metamorphosis. These observations suggest that bacterial QSSMs participate in H. symbiolongicarpus substrate selection by inducing larval chemotaxis and attachment. Furthermore, they support the notion that settlement in cnidarians is decoupled into two processes, attachment to the substrate and metamorphosis to a primary polyp, where QSSMs likely participate in the former but not in the latter.

RESUMEN Muchos invertebrados marinos sésiles tienen ciclos de vida que involucran el desarrollo de larvas que se asientan en sustratos específicos iniciando su metamorfosis a formas juveniles. Aunque es conocido que biopelículas bacterianas participan en este proceso, las señales químicas responsables hasta ahora se empiezan a investigar. Aquí evaluamos el papel de biofilms bacterianos y sus extractos de moléculas de señalización de "Quorum Sensing' (QSSM) sobre la quimiotaxis y el asentamiento larvario en Hydractinia symbiolongicarpus, un hidrozoario que crece sobre conchas de gastrópodos ocupadas por cangrejos ermitaños. Nosotros aislamos e identificamos taxonómicamente por secuenciación de rDNA 16S 14 cepas bacterianas de conchas con H. symbiolongicarpus. Tres de ellas, Shigella flexneri, Microbacterium liquefaciens, and Kocuria erythromyxa, mostraron producción de QSSMs usando biosensores que detectan N-acil-L-homoserin lactonas. Biopelículas y extractos de QSSMs de estas bacterias mostraron efectos quimiotácticos sobre larvas de H. symbiolongicarpus, efecto no observado en ensayos con cepas mutantes de E. coli y Chromobacterium violaceum que son incapaces de producir QSSMs. Las biopelículas y sus extractos indujeron adhesión larvaria sobre superficies, aunque solamente el 1 % de las larvas asentadas hicieron metamorfosis hacia pólipo primario, en contraste con 99 % de larvas incubadas con CsCl, un inductor artificial de asentamiento y metamorfosis. Estas observaciones sugieren que QSSMs de biopelículas bacterianas participan en la selección de sustrato de H. symbiolongicarpus, induciendo quimiotaxis y asentamiento de sus larvas. También sugieren que el asentamiento en cnidarios tiene dos procesos, adhesión y metamorfosis, donde las QSSMs participarían en el primero, pero no en el segundo.

Roles of signaling molecules in biofilm formation / 生物工程学报

Bacterial biofilm refers to a tunicate-like biological group composed of polysaccharide, protein and nucleic acid secreted by bacteria on the surface of the mucous membrane or biological material. The biofilm formation is a major cause of chronic infections. Bacteria could produce some secondary metabolites during the growth and reproduction. Some of them act as signaling molecules allowing bacteria to communicate and regulate many important physiological behaviors at multiple-cell level, such as bioluminescence, biofilm formation, motility and lifestyles. Usually, these signal molecules play an important role in the formation of bacterial biofilm. We review here the effects of related signal molecules of Quorum Sensing, cyclic diguanylate, Two-Component Systems and sRNA on the biofilm formation. Focusing on these regulation mechanism of signal molecules in the process of biofilm formation is necessary for the prevention and treatment of some chronic diseases.

Research progress on signaling molecules involved in articular cartilage repair / 生物医学工程学杂志

After the articular cartilage injury, the metabolic level is increased during the progressive degeneration, the chondrocytes secrete a variety of inflammatory factors, and the original cell phenotype is gradually changed. For a long time, a large number of researchers have done a lot of researches to promote anabolism of chondrocytes and to maintain the stability of chondrocyte phenotype. There are many molecular signaling pathways involved in the process of promoting cartilage repair. This review focuses on the key signaling molecules in articular cartilage repair, such as transforming growth factor-beta and bone morphogenetic protein, and reveals their roles in the process of cartilage injury and repair, so that researchers in related fields can understand the molecular mechanism of cartilage injury and repair widely and deeply. Based on this, they may find promising targets and biological methods for the treatment of cartilage injury.

Expression characteristics of signaling molecules associated with innate immune response induced by HSV1 and HSV2 in respiratory and vaginal epithelial cells / 中华微生物学和免疫学杂志

Objective To investigate the influences of herpes simplex virus 1 and 2 ( HSV1 and HSV2) infection on the expression of signaling molecules associated with innate immune response in respira-tory and vaginal epithelial cells for bettering understanding of HSV infection and pathological characteristics in the primary infection site, namely mucosal epithelial tissues. Methods KMB17 and VK2 cells were in-fected with HSV. Changes in cell morphology and inner structure after HSV infection were observed under optical microscope and scanning electron microscope, respectively. Viral proliferation in KMB17 and VK2 cells was detected by plaque assay, microcytopathic assay and real-time quantitative PCR. Expression of sig-naling molecules associated with innate immune response in virus-infected KMB17 and VK2 cells were ana-lyzed by real-time quantitative PCR. Results Both HSV1 and HSV2 could infect KMB17 and VK2 cells, and cause damage to cell morphology and inner structure after 12 hours. Both of the two viruses formed simi-lar plaque on the single layer of KMB17 and VK2 cells, although HSV2 proliferated slower than HSV1. There were differences in the expression of signaling molecules associated with innate immune response in-duced by the two viruses in KMB17 and VK2 cells. Conclusion Both HSV1 and HSV2 could infect and proliferate in epithelial cells ( KMB17 and VK2 cells) . Although there were slight differences in viral prolif-eration between them, significant differences in the expression of signaling molecules associated with innate immune response induced by the two viruses were observed.

Profiling the dynamic changes of PBMC immune-related indicators in patients with lung cancer after chemotherapy cycles / 中国肿瘤临床

Objective:To explore the optimal time point for combining chemotherapy and immunotherapy and provide an experimen-tal basis for immunotherapy intervention in clinical. Methods:Twenty-three lung cancer patients who completed five chemotherapy cycles between November 2015 and December 2016 in the First Affiliated Hospital of Xinxiang Medical University were enrolled in this study. Numbers of T lymphocyte subsets, B lymphocytes, and NK lymphocytes in peripheral blood were counted. Expression levels of T lymphocyte co-suppression molecule and cytokines in the peripheral blood mononuclear cell were detected using flow cytometry to analyze the dynamic changes of such indicators from one cycle to five cycles of chemotherapy. Results:Significant decreases in the lev-els of CD8+T lymphocytes, CD19+B lymphocytes, and CD16+CD56+NK cells and an increase in CD4+T lymphocytes were observed in the course of multi-cycle chemotherapy for patients with lung cancer. Differences were statistically significant (P<0.05). The co-suppres-sion molecular expression of PD-1, CTLA-4, and CCR-4 with T lymphocytes was downregulated, and the differences were significant (P<0.05). Conclusion:Profiling the dynamic changes of lymphocyte subsets and the expression of T lymphocyte co-suppression molecule are significant in multiple chemotherapy cycles for patients with lung cancer. In the later stage, the combined application of PD-1, PD-L1, CTLA-4, or CCR-4 antibody may exert good therapeutic effects for patients with a high expression level of related immune check-points.

Chemical agents modulating bacterial biofilm formation and development / 生物工程学报

Biofilm is a bacterial lifestyle ubiquitously in natural environments. Bacterial biofilm leads to drug resistance, a main reason why many infectious diseases are difficult to control. Due to the prominent points of biofilms implicated in infectious disease and the spread of multi-drug resistance, it is urgent to discover new antibacterial agents that can regulate biofilm formation and development. This review introduces chemical agents that could modulate bacterial biofilm formation and development.