Project description:Probiotics play important role in maintaining the health and extend longevity in their host. Previous studies reported several live probiotic bacteria in enhancing longevity and improving diverse feature of the host’s health. In this study, we reported a new potential heat- killed probiotic bacterium Levilactobacillus brevis strain MRKAK9 improved longevity and different features of healthy aging, including age-associated physical activity, improved resistance to biotic and abiotic stress in C. elegans. The mechanistic investigations showed that heat-killed strain MRKAK9 promoted longevity and healthy aging by downregulating insulin-signaling pathway resulting in improved proteostasis, autophagy and preserving lysosomal functionality in C. elegans. Heat-killed strain MRKAK9-mediated downregulation of insulin signaling pathway was regulated by the miRNA mir-243, suggesting that mir-243 partially involved in enhancing longevity of C. elegans. Additionally, the structural component exopolysaccharide of the strain heat-killed MRKAK9 also downregulated insulin- signaling mechanisms, increased the expression of genes involved in proteostatsis, autophagy as well as improved expression of mir-243. This study indicates that heat-killed strain MRKAK9 improves longevity and healthy aging, suggesting its candidature as a novel postbiotic.
Project description:Transcriptional profiling of Lactobacillus brevis UCCLBBS124 and UCCLBBS449 comparing control strain grown in MRS broth with strains growing in different stress conditons (5 % EtOH, pH4 or 30 ppm iso-a-acids).This study aimed to evaluate how certain Lb. brevis isolates are adapted so as to allow them to survive and grow in beer.
Project description:Housekeeping sigma factors in the Sigma70 family, as components of the RNA polymerase holoenzyme, are responsible for regulating transcription of genes related to vegetative growth. While these factors are well understood in model organisms such as Escherchia coli and Bacillus subtilis, little experimental work has focused on the sigma factors in members of the Lactobacillus genus such as Lactobacillus brevis and Lactobacillus plantarum. This study evaluates the ability of putative Sigma70 proteins from L. brevis (Sigma70-Lb) and L. plantarum (Sigma70-Lp) to complement a temperature sensitive mutation in E. coli 285c Sigma70. After finding that the heterologous sigma factors were capable of restoring the viability of E. coli 285c at 42 C through growth kinetics studies, the transcriptional responses of 285c to an extended heat shock in the presence of Sigma70-Lb and Sigma70-Lp were found to be similar to previous studies. These results indicate the Sigma70-Lb and Sigma70-Lp are capable of initiating transcription in a complex with the E. coli 285c RNA polymerase to a sufficient degree to restore viability at elevated temperatures without triggering unusual modifications to the native transcriptional program. These heterologous sigma factors may therefore be useful to improve biochemical knowledge of the sigma factor family or for use in transcriptional engineering. 3 biological replicates per sigma factor
Project description:Housekeeping sigma factors in the Sigma70 family, as components of the RNA polymerase holoenzyme, are responsible for regulating transcription of genes related to vegetative growth. While these factors are well understood in model organisms such as Escherchia coli and Bacillus subtilis, little experimental work has focused on the sigma factors in members of the Lactobacillus genus such as Lactobacillus brevis and Lactobacillus plantarum. This study evaluates the ability of putative Sigma70 proteins from L. brevis (Sigma70-Lb) and L. plantarum (Sigma70-Lp) to complement a temperature sensitive mutation in E. coli 285c Sigma70. After finding that the heterologous sigma factors were capable of restoring the viability of E. coli 285c at 42 C through growth kinetics studies, the transcriptional responses of 285c to an extended heat shock in the presence of Sigma70-Lb and Sigma70-Lp were found to be similar to previous studies. These results indicate the Sigma70-Lb and Sigma70-Lp are capable of initiating transcription in a complex with the E. coli 285c RNA polymerase to a sufficient degree to restore viability at elevated temperatures without triggering unusual modifications to the native transcriptional program. These heterologous sigma factors may therefore be useful to improve biochemical knowledge of the sigma factor family or for use in transcriptional engineering.
2011-12-31 | GSE28320 | GEO
Project description:Anti-obesity effects of heat-killed Lactobacillus salivarius 189
Project description:Influenza A(H1N1)pdm virus caused the first human pandemic of the 21st century. Although various probiotic Lactobacillus species have been shown to have anti-microbial effects against pneumonia-inducing pathogens, the prophylactic efficacy and mechanisms behind their protection remain largely unknown. Here, we evaluated the prophylactic efficacy of heat-killed Lactobacillus pentosus b240 against lethal influenza A(H1N1)pdm virus infection in a mouse model. To further define the protective responses induced by b240, we performed virologic, histopathologic, and transcriptomic analyses on the mouse lungs. Although we did not observe an appreciable effect of b240 on virus growth, cytokine production, or histopathology, gene expressional analysis revealed that oral administration of b240 differentially regulates antiviral gene expression in mouse lungs. Our results unveil the possible mechanisms behind the protection mediated by b240 against influenza virus infection and provide new insights into probiotic therapy.
Project description:Influenza A(H1N1)pdm virus caused the first human pandemic of the 21st century. Although various probiotic Lactobacillus species have been shown to have anti-microbial effects against pneumonia-inducing pathogens, the prophylactic efficacy and mechanisms behind their protection remain largely unknown. Here, we evaluated the prophylactic efficacy of heat-killed Lactobacillus pentosus b240 against lethal influenza A(H1N1)pdm virus infection in a mouse model. To further define the protective responses induced by b240, we performed virologic, histopathologic, and transcriptomic analyses on the mouse lungs. Although we did not observe an appreciable effect of b240 on virus growth, cytokine production, or histopathology, gene expressional analysis revealed that oral administration of b240 differentially regulates antiviral gene expression in mouse lungs. Our results unveil the possible mechanisms behind the protection mediated by b240 against influenza virus infection and provide new insights into probiotic therapy. Six-week-old female BALB/c mice were used in the study. Oral administration of b240 was initiated in mice at six weeks of age. Mice were orally administered heat-killed Lactobacillus pentosus b240 every day at a dose of 10 mg/mouse in 200 μl of buffered saline for 5 weeks. The control group received saline. To investigate the effects of oral administration of b240 on host immune responses to CA04 virus infection, 9 mice per group were infected with 10 MLD50 of CA04 virus on day 21 post-b240 administration. Three mice per group were euthanized on days 1, 3, and 6 post-infection and their lungs were collected. To investigate the immune responses induced by oral administration of b240 in the lungs of uninfected mice, 15 mice per group were mock-infected with PBS on day 21 post-b240 administration. Three mice per group were euthanized on days 14, 21, 22, 24, and 27 post-b240 administration (-7, 0, 1, 3, and 6 days post-mock infection) and their lungs were collected. These lung tissues were subjected to microarray analysis (three biological replicates per each group).