Longevity in Mice Is Promoted by Probiotic-Induced Suppression of Colonic Senescence Dependent on Upregulation of Gut Bacterial Polyamine Production

BACKGROUND: Chronic low-grade inflammation is recognized as an important factor contributing to senescence and age-related diseases. In mammals, levels of polyamines (PAs) decrease during the ageing process; PAs are known to decrease systemic inflammation by inhibiting inflammatory cytokine synthesis in macrophages. Reductions in intestinal luminal PAs levels have been associated with intestinal barrier dysfunction. The probiotic strain Bifidobacterium animalis subsp. lactis LKM512 is known to increase intestinal luminal PA concentrations. METHODOLOGY/PRINCIPAL FINDINGS: We supplemented the diet of 10-month-old Crj:CD-1 female mice with LKM512 for 11 months, while the controls received no supplementation. Survival rates were compared using Kaplan-Meier survival curves. LKM512-treated mice survived significantly longer than controls (P<0.001); moreover, skin ulcers and tumors were more common in the control mice. We then analyzed inflammatory and intestinal conditions by measuring several markers using HPLC, ELISA, reverse transcription-quantitative PCR, and histological slices. LKM512 mice showed altered 16S rRNA gene expression of several predominant intestinal bacterial groups. The fecal concentrations of PAs, but not of short-chain fatty acids, were significantly higher in LKM512-treated mice (P<0.05). Colonic mucosal function was also better in LKM512 mice, with increased mucus secretion and better maintenance of tight junctions. Changes in gene expression levels were evaluated using the NimbleGen mouse DNA microarray. LKM512 administration also downregulated the expression of ageing-associated and inflammation-associated genes and gene expression levels in 21-month-old LKM512-treated mice resembled those in 10-month-old untreated (younger) mice. CONCLUSION/SIGNIFICANCE: Our study demonstrated increased longevity in mice following probiotic treatment with LKM512, possibly due to the suppression of chronic low-grade inflammation in the colon induced by higher PA levels. This indicates that ingestion of specific probiotics may be an easy approach for improving intestinal health and increasing lifespan. Further studies are required to clarify its effectiveness in humans

The Efficacy and Safety of Dexmedetomidine for Procedural Sedation in Patients Receiving Local Anesthesia Outside the Intensive Care Unit: A Prospective, Double-Blind, Randomized Clinical Phase III Trial in Japan

Background: Few studies (in other countries than the US) have reported on the efficacy and safety of dexmedetomidine for sedation of patients undergoing surgical or medical procedures under local anesthesia without intubation outside the intensive care unit. We performed a randomized, double-blind study in Japan. Methods: Adult patients were randomly allocated to receive placebo, dexmedetomidine 0.5 μg/kg (DEX 0.5 group), or dexmedetomidine 1.0 μg/kg (DEX 1.0 group) over 10 min. Then, both dexmedetomidine groups received dexmedetomidine 0.2–0.7 μg/kg/h for maintaining an Observer’s Assessment of Alertness/Sedation Scale (OAA/S) score of ≤ 4; however, propofol was administered to rescue patients whose score exceeded this value. The primary endpoint was the percentage of patients who did not require rescue propofol to achieve and maintain an OAA/S score of ≤ 4. Results: In total, 162 patients were included in the placebo (n = 53), DEX 0.5 (n = 53), and DEX 1.0 (n = 56) groups. Propofol was not required in significantly more patients in the dexmedetomidine 0.5 and 1.0 μg/kg groups (52.8% and 57.1%, respectively) compared with the placebo group (1.9%) (P < 0.001 for both). Common adverse events were protocol-defined hypotension, respiratory depression and bradycardia. The incidence of bradycardia was significantly higher in the DEX 0.5 (26.4%) and DEX 1.0 (30.4%) groups than in the placebo group (9.4%) (P = 0.041 and P = 0.008, respectively). Conclusion: We concluded that a loading dose of 0.5 or 1.0 μg/kg dexmedetomidine followed by infusion at a rate of 0.2–0.7 μg/kg/h provided effective and welltolerated sedation in patients undergoing surgical or medical procedures under local anesthesia without intubation. Clinical trials.gov identifier: NCT0143893

Estimation of the local concentration of the markedly dense hydroxyl radical generation induced by X-rays in water

The density of X-ray-induced markedly dense hydroxyl radicals (•OH) in water was estimated based on EPR spin-trapping measurement using DMPO as the spin-trapping agent. A lower (0.13 mM‒2.3 M) concentration series of DMPO water solutions and higher (1.7‒4.8 M) concentration series of DMPO water solutions plus neat DMPO liquid (8.8 M as DMPO) were irradiated with 32 Gy of X-rays. Then, the yield of DMPO-OH in DMPO water solutions and the total spin-adduct of DMPO in neat DMPO were quantified. Estimating the EPR signal peak area by the line fitting method is only available for well-separated single EPR lines. For the higher concentration DMPO series, the EPR signal peak area was estimated by double integration. The baseline correction of the integral spectrum is necessary for accurate estimation of the double integration of EPR spectrum. In addition, using the suitable standard sample corresponding to the EPR sensitivity, which was variable by the electric permittivity according to DMPO concentration, was quite important for quantification of DMPO-OH especially in the higher DMPO concentration beyond 2 mM. The local density of •OH generation in water by X-ray irradiation was estimated from the inflection point on the plot of the DMPO-OH yield versus DMPO density. The density of X-ray-induced markedly dense •OH was estimated as 1184 μm-1, which was converted to 0.84 nm as the intermolecular distance and 2.8 M as the local concentration

Enhancement of Secondary Cell Wall Formation in Poplar Xylem Using a Self-Reinforced System of Secondary Cell Wall-Related Transcription Factors

The secondary cell wall (SCW) in the xylem is one of the largest sink organs of carbon in woody plants, and is considered a promising sustainable bioresource for biofuels and biomaterials. To enhance SCW formation in poplar (Populus sp.) xylem, we developed a self-reinforced system of SCW-related transcription factors from Arabidopsis thaliana, involving VASCULAR-RELATED NAC-DOMAIN7 (VND7), SECONDARY WALL-ASSOCIATED NAC-DOMAIN PROTEIN 1/NAC SECONDARY WALL THICKENING-PROMOTING FACTOR3 (SND1/NST3), and MYB46. In this system, these transcription factors were fused with the transactivation domain VP16 and expressed under the control of the Populus trichocarpa CesA18 (PtCesA18) gene promoter, creating the chimeric genes PtCesA18pro::AtVND7:VP16, PtCesA18pro::AtSND1:VP16, and PtCesA18pro::AtMYB46:VP16. The PtCesA18 promoter is active in tissues generating SCWs, and can be regulated by AtVND7, AtSND1, and AtMYB46; thus, the expression levels of PtCesA18pro::AtVND7:VP16, PtCesA18pro::AtSND1:VP16, and PtCesA18pro::AtMYB46:VP16 are expected to be boosted in SCW-generating tissues. In the transgenic hybrid aspens (Populus tremula x tremuloides T89) expressing PtCesA18pro::AtSND1:VP16 or PtCesA18pro::AtMYB46:VP16 grown in sterile half-strength Murashige and Skoog growth medium, SCW thickening was significantly enhanced in the secondary xylem cells, while the PtCesA18pro::AtVND7:VP16 plants showed stunted xylem formation, possibly because of the enhanced programmed cell death (PCD) in the xylem regions. After acclimation, the transgenic plants were transferred from the sterile growth medium to pots of soil in the greenhouse, where only the PtCesA18pro::AtMYB46:VP16 aspens survived. A nuclear magnetic resonance footprinting cell wall analysis and enzymatic saccharification analysis demonstrated that PtCesA18pro::AtMYB46:VP16 influences cell wall properties such as the ratio of syringyl (S) and guaiacyl (G) units of lignin, the abundance of the lignin beta-aryl ether and resinol bonds, and hemicellulose acetylation levels. Together, these data indicate that we have created a self-reinforced system using SCW-related transcription factors to enhance SCW accumulation

Loss of histone H4K20 trimethylation predicts poor prognosis in breast cancer and is associated with invasive activity

INTRODUCTION: Loss of histone H4 lysine 20 trimethylation (H4K20me3) is associated with multiple cancers, but its role in breast tumors is unclear. In addition, the pathological effects of global reduction in H4K20me3 remain mostly unknown. Therefore, a major goal of this study was to elucidate the global H4K20me3 level in breast cancer tissue and investigate its pathological functions. METHODS: Levels of H4K20me3 and an associated histone modification, H3 lysine 9 trimethylation (H3K9me3), were evaluated by immunohistochemistry in a series of breast cancer tissues. Univariate and multivariate clinicopathological and survival analyses were performed. We also examined the effect of overexpression or knockdown of the histone H4K20 methyltransferases, SUV420H1 and SUV420H2, on cancer-cell invasion activity in vitro. RESULTS: H4K20me3, but not H3K9me3, was clearly reduced in breast cancer tissue. A reduced level of H4K20me3 was correlated with several aspects of clinicopathological status, including luminal subtypes, but not with HER2 expression. Multivariate analysis showed that reduced levels of H4K20me3 independently associated with lower disease-free survival. Moreover, ectopic expression of SUV420H1 and SUV420H2 in breast cancer cells suppressed cell invasiveness, whereas knockdown of SUV420H2 activated normal mammary epithelial-cell invasion in vitro. CONCLUSIONS: H4K20me3 was reduced in cancerous regions of breast-tumor tissue, as in other types of tumor. Reduced H4K20me3 level can be used as an independent marker of poor prognosis in breast cancer patients. Most importantly, this study suggests that a reduced level of H4K20me3 increases the invasiveness of breast cancer cells in a HER2-independent manner

Adipose tissue : Critical contributor to the development of prostate cancer

The prostate is surrounded by periprostatic adipose tissue. Although adipose tissue was thought to play limited physiological roles, it has recently been recognized as an active endocrine organ, secreting growth factors and adipokines. Epidemiologically, obesity is associated with prostate cancer progression. A major mechanism to explain the link between obesity and cancer includes the insulin and insulin-like growth factor (IGF)-1 axis, sex steroids, and adipokines. When prostate cancer cells invade periprostatic adipose tissue, adipose tissue contributes to create the tumor microenvironment, mainly via adipokine secretion. Furthermore, direct crosstalk between adipocytes and cancer cells can exist.We showed that fatty acid-binding protein 4 (FABP4) released from adipocytes was taken up into prostate cancer cells and may act as a carrier of an energy source for the invasion. Bone is an adipocyte-rich organ and is the common metastatic site of prostate cancer. In the microenvironment of bone metastases, tumor cells, osteoblasts, osteoclasts, adipocytes, and other stromal cells are interacting with one another and organizing a complex system. Thus, growing evidence implicates adipose tissue as a critical contributor to the development of prostate cancer. A deeper understanding of the mechanisms leads to more effective therapeutic strategies for prostate cancer

Expression of Ascorbate Peroxidase Derived from Cyanidioschyzon merolae in Mammalian Cells

Background: Ascorbate peroxidase (APX) derived from Cyanidioschyzon merolae, a primitive red alga living in high temperature and acidic environments, has a greater anti-oxidative capacity than similar peroxidases occurring in other plants. In the present study, we examined the ability of Cyanidioschyzon merolae-derived APX (cAPX) to increase anti-oxidative capacity when expressed in mammalian cells. Materials and Methods: The cAPX gene was introduced into the mouse fibroblast-like cell line C3H10T1/2. Production of reactive oxygen species (ROS) and/or cell viability was assessed after heat, H2O2 and acid stimulation. Results: Heat and H2O2 stimulation caused ROS production. cAPX-expressing cells were more tolerant to oxidative stress induced by heat, H2O2 and acid stimulations than control cells lacking cAPX. Conclusion: Introduction of cAPX increases anti-oxidative capacity in mammalian cells

Bioactive polyamine production by a novel hybrid system comprising multiple indigenous gut bacterial strategies

個々の腸内細菌の生き残り戦略が組み合わさることで、 機能性物質ポリアミンが産生されていることを発見しました. 京都大学プレスリリース. 2018-07-06.Metabolites of the intestinal microbiota are thought to be generated through metabolic pathways spanning multiple taxa of intestinal bacteria. We have previously shown that the level of putrescine, a polyamine found abundantly in the human intestinal lumen, is increased in the colonic lumen following administration of arginine and the probiotic Bifidobacterium sp.; however, the underlying mechanism remained poorly understood. We report a novel pathway for putrescine production from arginine through agmatine involving the collaboration of two bacterial groups, and triggered by environmental acidification (drop in pH to below 6.5 from neutral). This pathway comprises the acid tolerance system of Escherichia coli, representing bacteria that have an arginine-dependent acid resistance system; the energy production system of Enterococcus faecalis, representing bacteria that have an agmatine deiminase system; and the acid production system of the acid-producing bacteria, represented by Bifidobacterium spp. This pathway is unique in that it represents a relationship between the independent survival strategies of multiple bacteria