Lifestyle Factors Associated With Erosive Esophagitis in Japanese Individuals With and Without Obesity Undergoing Health Checkups.

BACKGROUND: Several lifestyle factors have been reported to be associated with erosive esophagitis (EE). Many studies examined the associated factors for EE independent of obesity. However, lifestyle factors associated with EE might differ depending on sex or the presence of obesity. This study thus aimed to investigate the lifestyle risk factors for EE stratified by obesity and sex. METHODS: A cross-sectional survey was conducted among Japanese people who underwent an annual health checkup at the Oita Health Checkup Center between 2019 and 2021. Multivariate analysis was performed to determine the factors associated with EE in participants stratified by sex and the presence of obesity. RESULTS: EE was diagnosed in 676 of 5240 participants (12.9%) who were analyzed, and occurred most often in males (601 cases). The percentage of obesity based on body mass index was significantly higher among EE than non-EE participants (50.3% and 26.5%, P < .001). In obese males, eating just before bedtime (OR = 1.34, 95% CI 1.01-1.78) and hiatal hernia (OR = 3.42, 95% CI 2.57-4.54) were significantly associated with EE in multivariate analysis. In non-obese males, current smoking (OR = 1.48, 95% CI 1.07-2.04), alcohol consumption of 40 to 60 g/day (OR = 1.60, 95% CI 1.11-2.30), and hiatal hernia (OR = 3.63, 95% CI 2.79-4.73) were significantly associated with EE. CONCLUSIONS: We found that factors associated with EE were different between obese and non-obese males. In obese males, avoiding going to bed within 2 h after dinner might contribute to preventing the occurrence of EE. In non-obese males, prevention of obesity, quitting smoking, and avoiding heavy alcohol consumption might be important for preventing the development of EE.

Characterization of the cAMP phosphodiesterase domain in plant adenylyl cyclase/cAMP phosphodiesterase CAPE from the liverwort Marchantia polymorpha.

Cyclic AMP (cAMP) acts as a second messenger and is involved in the regulation of various physiological responses. Recently, we identified the cAMP-synthesis/hydrolysis enzyme CAPE, which contains the two catalytic domains adenylyl cyclase (AC) and cAMP phosphodiesterase (PDE) from the liverwort Marchantia polymorpha. Here we characterize the PDE domain of M. polymorpha CAPE (MpCAPE-PDE) using the purified protein expressed in E. coli. The Km and Vmax of MpCAPE-PDE were 30 µM and 5.8 nmol min-1 mg-1, respectively. Further, we investigated the effect of divalent cations on PDE activity and found that Ca2+ enhanced PDE activity, suggesting that Ca2+ may be involved in cAMP signaling through the regulation of PDE activity of CAPE. Among the PDE inhibitors tested, only dipyridamole moderately inhibited PDE activity by approximately 40% at high concentrations. Conversely, 3-isobutyl-1-methylxanthine (IBMX) did not inhibit PDE activity.

Distribution of adenylyl cyclase/cAMP phosphodiesterase gene, CAPE, in streptophytes reproducing via motile sperm.

We recently isolated a novel adenylyl cyclase/cAMP phosphodiesterase gene from the liverwort, Marchantia polymorpha. The protein encoded by this gene has a class III adenylyl cyclase (AC) in the C-terminal domain and class I phosphodiesterase (PDE) in the N-terminal domain; therefore, we named it CAPE (COMBINED AC with PDE). CAPE protein is likely involved in spermatogenesis and sperm motility due to its tissue-specific expression pattern in M. polymorpha and the distribution of CAPE genes in streptophytes. However, little is known about the distribution of CAPE in gymnosperms that use motile sperm for fertilization, such as cycads and ginkgo. The present study aimed to isolate CAPE genes from the cycad, Cycas revoluta, the ginkgo, Ginkgo biloba, and the hornwort, Anthoceros agerestis. Sequences with high homology to CAPE were obtained from these species. Our analyses revealed that all plant taxonomic groups reproducing via motile sperm possessed CAPE, whereas those that do not produce motile sperm did not possess CAPE, with one exception in gymnosperm Cupressales. The phylogenic distribution of CAPE almost corresponds to the evolutionary history of motile sperm production and further suggests that CAPE may be involved in sexual reproduction process using motile sperm in streptophytes.

Induction of Maltose Release by Light in the Endosymbiont Chlorella variabilis of Paramecium bursaria.

The endosymbiotic green algae of Paramecium bursaria are known to release a photosynthate to the host cells. The endosymbiont Chlorella variabilis F36-ZK isolated in Japan releases maltose under acidic conditions, and such release requires both light and low pH. However, whether photosynthate release is due to light sensing by photoreceptors or is merely a consequence of active photosynthesis is unclear. Herein, we studied the effect of light on maltose release from C. variabilis F36-ZK; we measured maltose release using a combination of 1-phenyl-3-methyl-5-pyrazolone derivative and 14C-tracer methods. Blue (450nm) or red (around 600nm) light was most effective to stimulate maltose release. This suggests that the photosynthetic pathway probably participates in maltose release, because the effective wavelength corresponds to the absorption spectrum of chlorophyll. Furthermore, maltose release was slightly affected by addition of a photosynthetic inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, but was abolished by another inhibitor of photosynthesis, 2,5-dibromo-6-isopropyl-3-methyl-1,4-benzoquinone, suggesting that electron flow through photosystem I may be more involved in maltose release. Interestingly, starving F36-ZK cells cultured under prolonged dark conditions did not release maltose but retained their photosynthetic capacity. Our results thus show that maltose release is regulated by light and cellular conditions in endosymbiotic Chlorella.