Background
This study aimed to examine the effects of Lactobacillus casei strain Shirota (LcS) on gut–brain interactions under stressful conditions.
Methods
Three double‐blind, placebo‐controlled ...trials were conducted to examine the effects of LcS on psychological and physiological stress responses in healthy medical students under academic examination stress. Subjects received LcS‐fermented milk or placebo daily for 8 weeks prior to taking a national standardized examination. Subjective anxiety scores, salivary cortisol levels, and the presence of physical symptoms during the intervention were pooled and analyzed. In the animal study, rats were given feed with or without LcS for 2 weeks, then submitted to water avoidance stress (WAS). Plasma corticosterone concentration and the expression of cFos and corticotropin releasing factor (CRF) in the paraventricular nucleus (PVN) were measured immediately after WAS. In an electrophysiological study, gastric vagal afferent nerve activity was monitored after intragastric administration of LcS to urethane‐anesthetized rats.
Key Results
Academic stress‐induced increases in salivary cortisol levels and the incidence rate of physical symptoms were significantly suppressed in the LcS group compared with the placebo group. In rats pretreated with LcS, WAS‐induced increases in plasma corticosterone were significantly suppressed, and the number of CRF‐expressing cells in the PVN was reduced. Intragastric administration of LcS stimulated gastric vagal afferent activity in a dose‐dependent manner.
Conclusions & Inferences
These findings suggest that LcS may prevent hypersecretion of cortisol and physical symptoms under stressful conditions, possibly through vagal afferent signaling to the brain and reduced stress reactivity in the PVN.
We examined the effects of the probiotic Lactobacillus casei strain Shirota (LcS) on stress markers and stress‐related symptoms in healthy medical students preparing for a major examination, and found that salivary cortisol levels and physical complaints which increased toward the exam day were significantly suppressed by LcS treatment. Results of animal studies suggested that the ingestion of LcS suppresses stress‐induced increases in glucocorticoids, possibly through vagal afferent signaling from the upper intestines to the brain and reduced stress reactivity in the hypothalamus.
Aims
To confirm the stress‐relieving effects of heat‐inactivated, enteric‐colonizing Lactobacillus gasseri CP2305 (paraprobiotic CP2305) in medical students taking a cadaver dissection course.
...Methods and Results
Healthy students (21 males and 11 females) took paraprobiotic CP2305 daily for 5 weeks during a cadaver dissection course. The General Health Questionnaire and the Pittsburgh Sleep Quality Index were employed to assess stress‐related somatic symptoms and sleep quality respectively. The aggravation of stress‐associated somatic symptoms was observed in female students (P = 0·029). Sleep quality was improved in the paraprobiotic CP2305 group (P = 0·038), particularly in men (P = 0·004). Among men, paraprobiotic CP2305 shortened sleep latency (P = 0·035) and increased sleep duration (P = 0·048). Diarrhoea‐like symptoms were also effectively controlled with CP2305 (P = 0·005) in men. Thus, we observed sex‐related differences in the effects of paraprobiotic CP2305. In addition, CP2305 affected the growth of faecal Bacteroides vulgatus and Dorea longicatena, which are involved in intestinal inflammation.
Conclusions
CP2305 is a potential paraprobiotic that regulates stress responses, and its beneficial effects may depend on specific cell component(s).
Significance and Impact of the Study
This study characterizes the effects of a stress‐relieving para‐psychobiotic in humans.
This pilot study investigated the effects of the probiotic Lactobacillus casei strain Shirota (LcS) on psychological, physiological, and physical stress responses in medical students undertaking an ...authorised nationwide examination for promotion. In a double-blind, placebo-controlled trial, 24 and 23 healthy medical students consumed a fermented milk containing LcS and a placebo milk, respectively, once a day for 8 weeks until the day before the examination. Psychophysical state, salivary cortisol, faecal serotonin, and plasma L-tryptophan were analysed on 5 different sampling days (8 weeks before, 2 weeks before, 1 day before, immediately after, and 2 weeks after the examination). Physical symptoms were also recorded in a diary by subjects during the intervention period for 8 weeks. In association with a significant elevation of anxiety at 1 day before the examination, salivary cortisol and plasma L-tryptophan levels were significantly increased in only the placebo group (P<0.05). Two weeks after the examination, the LcS group had significantly higher faecal serotonin levels (P<0.05) than the placebo group. Moreover, the rate of subjects experiencing common abdominal and cold symptoms and total number of days experiencing these physical symptoms per subject were significantly lower in the LcS group than in the placebo group during the pre-examination period at 5-6 weeks (each P<0.05) and 7-8 weeks (each P<0.01) during the intervention period. Our results suggest that the daily consumption of fermented milk containing LcS may exert beneficial effects preventing the onset of physical symptoms in healthy subjects exposed to stressful situations.
Serine/arginine-rich splicing factor 3 (SRSF3) likely has wide-ranging roles in gene expression and facilitation of tumor cell growth. SRSF3 knockdown induced G1 arrest and apoptosis in colon cancer ...cells (HCT116) in association with altered expression of 833 genes. Pathway analysis revealed 'G1/S Checkpoint Regulation' as the most highly enriched category in the affected genes. SRSF3 knockdown did not induce p53 or stimulate phosphorylation of p53 or histone H2A.X in wild-type HCT116 cells. Furthermore, the knockdown induced G1 arrest in p53-null HCT116 cells, suggesting that p53-dependent DNA damage responses did not mediate the G1 arrest. Real-time reverse transcription-polymerase chain reaction and western blotting confirmed that SRSF3 knockdown reduced mRNA and protein levels of cyclins (D1, D3 and E1), E2F1 and E2F7. The decreased expression of cyclin D and E2F1 likely impaired the G1-to-S-phase progression. Consequently, retinoblastoma protein remained hypophosphorylated in SRSF3 knockdown cells. The knockdown also induced apoptosis in association with reduction of BCL2 protein levels. We also found that SRSF3 knockdown facilitated skipping of 81 5'-nucleotides (27 amino acids) from exon 8 of homeodomain-interacting protein kinase-2 (HIPK2) and produced a HIPK2 Δe8 isoform. Full-length HIPK2 (HIPK2 FL) is constantly degraded through association with an E3 ubiquitin ligase (Siah-1), whereas HIPK2 Δe8, lacking the 27 amino acids, lost Siah-1-binding ability and became resistant to proteasome digestion. Interestingly, selective knockdown of HIPK2 FL induced apoptosis in various colon cancer cells expressing wild-type or mutated p53. Thus, these findings disclose an important role of SRSF3 in the regulation of the G1-to-S-phase progression and alternative splicing of HIPK2 in tumor growth.
RNA-binding proteins and microRNAs are potent post-transcriptional regulators of gene expression. Human transformer 2β (Tra2β) is a serine/arginine-rich-like protein splicing factor and is now ...implicated to have wide-ranging roles in gene expression as an RNA-binding protein. RNA immunoprecipitation (RIP) with an anti-Tra2β antibody and microarray analysis identified a subset of Tra2β-associated mRNAs in HCT116 human colon cancer cells, many of which encoded cell death-related proteins including Bcl-2 (B-cell CLL/lymphoma 2). Tra2β knockdown in HCT116 cells decreased Bcl-2 expression and induced apoptosis. Tra2β knockdown accelerated the decay of BCL2α mRNA that encodes Bcl-2 and full-length 3' UTR, while it did not affect the stability of BCL2β mRNA having a short, alternatively spliced 3' UTR different from BCL2α 3' UTR. RIP assays with anti-Tra2β and anti-Argonaute 2 antibodies, respectively, showed that Tra2β bound to BCL2α 3' UTR, and that Tra2β knockdown facilitated association of miR-204 with BCL2α 3' UTR. The consensus sequence (GAA) for Tra2β-binding lies within the miR-204-binding site of BCL2 3' UTR. Mutation of the consensus sequence canceled the binding of Tra2β to BCL2 3' UTR without disrupting miR-204-binding to BCL2 3' UTR. Transfection of an anti-miR-204 or introduction of three-point mutations into the miR-204-binding site increased BCL2 mRNA and Bcl-2 protein levels. Inversely, transfection of precursor miR-204 reduced their levels. Experiments with Tra2β-silenced or overexpressed cells revealed that Tra2β antagonized the effects of miR-204 and upregulated Bcl-2 expression. Furthermore, TRA2β mRNA expression was significantly upregulated in 22 colon cancer tissues compared with paired normal tissues and positively correlated with BCL2 mRNA expression. Tra2β knockdown in human lung adenocarcinoma cells (A549) increased their sensitivity to anticancer drugs. Taken together, our findings suggest that Tra2β regulates apoptosis by modulating Bcl-2 expression through its competition with miR-204. This novel function may have a crucial role in tumor growth.
The present study examined whether Lactobacillus casei strain Shirota (LcS) improves sleep quality under psychological stress. A double-blind, placebo-controlled trial was conducted in healthy 4
year ...medical students exposed to academic examination stress. The trial was repeated over two consecutive years in different groups of students, and the data were pooled. For 8 weeks prior to and 3 weeks after a national standardised examination, a total of 48 and 46 subjects received a daily dose of 100 ml of LcS-fermented milk or non-fermented placebo milk, respectively. Study measures included subjective anxiety, overnight single-channel electroencephalography (EEG) recordings, and the Oguri-Shirakawa-Azumi (OSA) sleep inventory scores of subjective sleep quality. Total OSA scores were significantly lower than baseline on the day before the exam and recovered after the exam, indicating a stress-induced decline in sleep quality. There was a significant positive effect of LcS treatment on OSA factors for sleepiness on rising and sleep length. Sleep latency measured by EEG lengthened as the exam approached in the placebo group but was significantly suppressed in the LcS group. The percentage of stage 3 non-REM (N3) sleep decreased in the placebo group as the exam approached, whereas it was maintained in the LcS group throughout the trial. Delta power during the first sleep cycle, measured as an index of sleep intensity, increased as the exam approached in the LcS group and was significantly higher than in the placebo group. These findings suggest that daily consumption of LcS may help to maintain sleep quality during a period of increasing stress. The observed retention of N3 sleep and increased delta power in the LcS group may have contributed to higher perceived sleep satisfaction.
Aims
To clarify the effects of Lactobacillus gasseri CP2305 (CP2305) on quality of life and clinical symptoms and its functional mechanisms in patients with irritable bowel syndrome (IBS).
Methods ...and Results
After the patients were administered CP2305 daily for 4 weeks, the IBS‐severity index score was significantly improved compared with that of the placebo group, and this improvement was accompanied by a reduction in health‐related worry and changes in intestinal microbiota. The gene expression profiling of the peripheral blood leucocytes showed that CP2305 treatment significantly up‐regulated genes related to eukaryotic initiation factor 2 (EIF2) signalling. Eighty‐two genes were down‐regulated in IBS patients compared with healthy controls. The expression of 23 of these genes exhibited a CP2305‐dependent increase associated with an improvement in IBS severity. The majority of the restored genes were related to EIF2 signalling.
Conclusions
CP2305 administration is a potential candidate therapeutic option for patients with IBS.
Significance and Impact of the Study
Although probiotics have been proposed to benefit IBS patients, objective clinical evidence and elucidation of the functional mechanism remain insufficient. Our study demonstrated that CP2305 administration beneficially influences IBS patients in both subjective and objective evaluations, and gene expression profiling provided insights into the functional mechanism.
Homeodomain-interacting protein kinase 2 (HIPK2) is a potential tumor suppressor that has a crucial role in the DNA damage response (DDR) by regulating cell-cycle checkpoint activation and apoptosis. ...However, it is unclear whether HIPK2 exerts distinct roles in DNA damage repair. The aim of this study was to identify novel target molecule(s) of HIPK2, which mediates HIPK2-dependent DNA damage repair. HIPK2-knockdown human colon cancer cells (HCT116) or hipk1/hipk2 double-deficient mouse embryonic fibroblasts could not remove histone H2A.X phosphorylated at Ser139 (γH2A.X) after irradiation with a sublethal dose (10 J/m(2)) of ultraviolet (UV)-C, resulting in apoptosis. Knockdown of HIPK2 in p53-null HCT116 cells similarly promoted the UV-C-induced γH2A.X accumulation and apoptosis. Proteomic analysis of HIPK2-associated proteins using liquid chromatography-tandem mass spectrometry identified heterochromatin protein 1γ (HP1γ) as a novel target for HIPK2. Immunoprecipitation experiments with HCT116 cells expressing FLAG-tagged HIPK2 and one of the HA-tagged HP1 family members demonstrated that HIPK2 specifically associated with HP1γ, but not with HP1α or HP1β, through its chromo-shadow domain. Mutation of the HP1box motif (883-PTVSV-887) within HIPK2 abolished the association. HP1γ knockdown also enhanced accumulation of γH2A.X and apoptosis after sublethal UV-C irradiation. In vitro kinase assay demonstrated an HP1γ-phosphorylating activity of HIPK2. Sublethal UV-C irradiation phosphorylated HP1γ. This phosphorylation was absent in endogenous HIPK2-silenced cells with HIPK2 3'UTR siRNA. Overexpression of FLAG-HIPK2, but not the HP1box-mutated or kinase-dead HIPK2 mutant, in the HIPK2-silenced cells increased HP1γ binding to trimethylated (Lys9) histone H3 (H3K9me3), rescued the UV-C-induced phosphorylation of HP1γ, triggered release of HP1γ from histone H3K9me3 and suppressed γH2A.X accumulation. Our results suggest that HIPK2-dependent phosphorylation of HP1γ may participate in the regulation of dynamic interaction between HP1γ and histone H3K9me3 to promote DNA damage repair. This HIPK2/HP1γ pathway may uncover a new functional aspect of HIPK2 as a tumor suppressor.
BACKGROUND & AIMS: An antiulcer drug, geranylgeranylacetone (GGA), rapidly induces resistance of gastric mucosal cells to irritants in vivo and in vitro. The aim of this study was to elucidate the ...mechanism of this action. METHODS: Heat shock proteins (HSPs) were detected by immunoblotting with antibody against HSP90, HSP70, heat shock cognate protein 70, or HSP60. HSP70 messenger RNA level was measured by Northern hybridization with an HSP70 complementary DNA probe. Activation of the heat shock factor was detected by gel mobility shift assay with the heat shock element oligonucleotide. RESULTS: GGA induced resistance of cultured guinea pig gastric mucosal cells against ethanol- induced exfoliation and damage within 30 minutes, proportionally to the induction of the HSPs. This protection was blocked by cycloheximide but not by indomethacin. GGA caused rapid activation of heat shock factor 1 and expression of HSP70 messenger RNA in the cells. Intragastric administration of GGA to rats induced HSPs in gastric mucosa. The administration of GGA additionally enhanced the heat shock response and reduced ulcer formation in rats subjected to restraint and water- immersion stress. CONCLUSIONS: GGA may induce transcriptional activation of HSP genes, and this novel action may increase gastric mucosal defense at conditions of stress. (Gastroenterology 1996 Aug;111(2):345-57)
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