The sialyl-Tn antigen synthase genes regulates migration-proliferation dichotomy in prostate cancer cells under hypoxia.

A low-oxygen (hypoxia) tumor microenvironment can facilitate chemotherapy and radiation therapy resistance in tumors and is associated with a poor prognosis. Hypoxia also affects PCa (prostate cancer) phenotype transformation and causes therapeutic resistance. Although O-glycans are known to be involved in the malignancy of various cancers under hypoxia, the expression and function of O-glycans in PCa are not well understood. In this study, the saccharide primer method was employed to analyze O-glycan expression in PCa cells. Results showed that the expression of sTn antigens was increased in PCa cells under hypoxia. Furthermore, it was found that ST6GalNAc1, the sTn antigen synthase gene, was involved in the migration-proliferation dichotomy and drug resistance in PCa cells under hypoxia. The results of this study will contribute to the development of novel diagnostic markers and drug targets for PCa under hypoxia.

A Pacific Oyster-Derived Antioxidant, DHMBA, Protects Renal Tubular HK-2 Cells against Oxidative Stress via Reduction of Mitochondrial ROS Production and Fragmentation.

The kidney contains numerous mitochondria in proximal tubular cells that provide energy for tubular secretion and reabsorption. Mitochondrial injury and consequent excessive reactive oxygen species (ROS) production can cause tubular damage and play a major role in the pathogenesis of kidney diseases, including diabetic nephropathy. Accordingly, bioactive compounds that protect the renal tubular mitochondria from ROS are desirable. Here, we aimed to report 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA), isolated from the Pacific oyster (Crassostrea gigas) as a potentially useful compound. In human renal tubular HK-2 cells, DHMBA significantly mitigated the cytotoxicity induced by the ROS inducer L-buthionine-(S, R)-sulfoximine (BSO). DHMBA reduced the mitochondrial ROS production and subsequently regulated mitochondrial homeostasis, including mitochondrial biogenesis, fusion/fission balance, and mitophagy; DHMBA also enhanced mitochondrial respiration in BSO-treated cells. These findings highlight the potential of DHMBA to protect renal tubular mitochondrial function against oxidative stress.

Cytokinins Induce Prehaustoria Coordinately with Quinone Signals in the Parasitic Plant Striga hermonthica.

Orobanchaceae parasitic plants are major threats to global food security, causing severe agricultural damage worldwide. Parasitic plants derive water and nutrients from their host plants through multicellular organs called haustoria. The formation of a prehaustorium, a primitive haustorial structure, is provoked by host-derived haustorium-inducing factors (HIFs). Quinones, including 2,6-dimethoxy-p-benzoquinone (DMBQ), are of the most potent HIFs for various species in Orobanchaceae, but except non-photosynthetic holoparasites, Phelipanche and Orobanche spp. Instead, cytokinin (CK) phytohormones were reported to induce prehaustoria in Phelipanche ramosa. However, little is known about whether CKs act as HIFs in the other parasitic species to date. Moreover, the signaling pathways for quinones and CKs in prehaustorium induction are not well understood. This study shows that CKs act as HIFs in the obligate parasite Striga hermonthica but not in the facultative parasite Phtheirospermum japonicum. Using chemical inhibitors and marker gene expression analysis, we demonstrate that CKs activate prehaustorium formation through a CK-specific signaling pathway that overlaps with the quinone HIF pathway at downstream in S. hermonthica. Moreover, host root exudates activated S. hermonthica CK biosynthesis and signaling genes, and DMBQ and CK inhibitors perturbed the prehaustorium-inducing activity of exudates, indicating that host root exudates include CKs. Our study reveals the importance of CKs for prehaustorium formation in obligate parasitic plants.

Liposomal adhesion via electrostatic interactions and osmotic deflation increase membrane tension and lipid diffusion coefficient.

Membrane adhesion is a ubiquitous phenomenon in cells and is related to various biological events such as migration, morphogenesis, and differentiation. To understand the physicochemical aspects of membrane adhesion, liposome-liposome adhesion and liposome-substrate adhesion have been studied. Although membrane adhesion has been shown to increase membrane tension and inhibit lipid diffusion, the relationship between these changes and the degree of membrane adhesion have not been quantified. Here, we analyzed the dependence of membrane tension and lipid diffusion on the degree of membrane adhesion, i.e., area fraction of the adherent region. For this purpose, we developed a simple method to prepare adhered liposomes by simple electrostatic interactions between the membranes and by osmotic deflation. We found that the membrane tension of the adhered liposomes increases slightly with an increase in the area fraction of the adherent region. In addition, the lipid diffusion coefficient of the adhered liposomes is larger than that of isolated liposomes, which is consistent with the theoretical prediction. The analysis provides a framework to understand the correlation between cell adhesion and bio-membrane properties such as membrane tension and molecular diffusion.

JAZF1 promotes proliferation of C2C12 cells, but retards their myogenic differentiation through transcriptional repression of MEF2C and MRF4-Implications for the role of Jazf1 variants in oncogenesis and type 2 diabetes.

Single-nucleotide polymorphisms associated with type 2 diabetes (T2D) have been identified in Jazf1, which is also involved in the oncogenesis of endometrial stromal tumors. To understand how Jazf1 variants confer a risk of tumorigenesis and T2D, we explored the functional roles of JAZF1 and searched for JAZF1 target genes in myogenic C2C12 cells. Consistent with an increase of Jazf1 transcripts during myoblast proliferation and their decrease during myogenic differentiation in regenerating skeletal muscle, JAZF1 overexpression promoted cell proliferation, whereas it retarded myogenic differentiation. Examination of myogenic genes revealed that JAZF1 overexpression transcriptionally repressed MEF2C and MRF4 and their downstream genes. AMP deaminase1 (AMPD1) was identified as a candidate for JAZF1 target by gene array analysis. However, promoter assays of Ampd1 demonstrated that mutation of the putative binding site for the TR4/JAZF1 complex did not alleviate the repressive effects of JAZF1 on promoter activity. Instead, JAZF1-mediated repression of Ampd1 occurred through the MEF2-binding site and E-box within the Ampd1 proximal regulatory elements. Consistently, MEF2C and MRF4 expression enhanced Ampd1 promoter activity. AMPD1 overexpression and JAZF1 downregulation impaired AMPK phosphorylation, while JAZF1 overexpression also reduced it. Collectively, these results suggest that aberrant JAZF1 expression contributes to the oncogenesis and T2D pathogenesis.

Involvement of 5-HT3 and 5-HT4 receptors in the regulation of circadian clock gene expression in mouse small intestine.

Several lines of evidence suggest that 5-HT receptors play a critical role in the expression of clock genes in the suprachiasmatic nucleus, the main circadian oscillator in hamsters. The contributions of 5-HT-receptor subtypes in the intestine, where they are expressed at high concentrations, are however not yet clarified. The 5-HT synthesis inhibitor, p-chlorophenylalanine, attenuated the daily rhythm of Per1 and Per2 gene expression in the intestine. Injection of 5-HT and agonists of the 5-HT3 and 5-HT4 receptors increased Per1/Per2 expression and decreased Bmal1 expression in a dose-dependent manner. Although treatment with antagonists of 5-HT3 and 5-HT4 alone did not affect clock gene expression, co-injection of these antagonists with 5-HT blocked the 5-HT-induced changes in clock gene expression. Increased tissue levels of 5-HT due to treatment with the antidepressants clomipramine and fluvoxamine did not affect clock gene expression. The present results suggest that the 5-HT system in the small intestine may play a critical role in regulating circadian rhythms through 5-HT3/5-HT4-receptor activation.

A Survey of the Status of Methadone Switching in Japan Using a Hospital-Based Administrative Claims Database.

Methadone is generally used for the management of cancer pain in patients who cannot obtain adequate analgesia from other strong opioids; however, it has a complicated and inconsistent conversion ratio from pre-switching opioid dosage to methadone. This issue may be pronounced in Japan because only oral tablets are commercially available. We aimed to elucidate the status of methadone switching in Japan, focusing on its dosage. Using a Japanese hospital-based administrative claims database, we included patients who switched to methadone between April 2008 and January 2021. The proportion of methadone switching completion that required more than the defined conversion ratio in the Japanese package insert (called "high-dose methadone switching") was evaluated as a primary endpoint. Other endpoints included "the duration from initiation to completion of methadone switching" and "factors affecting high-dose methadone switching by using multivariate logistic regression analysis". Of 1585 patients who received methadone, 370 were enrolled. Among those, 130 (35.1%) received high-dose methadone switching. The median duration of methadone switching completion (12 days) was longer in the high-dose methadone switching group than in other patients. Four variables were identified as factors affecting high-dose methadone switching. Younger age and outpatient status increased the risk of requiring high-dose methadone switching, whereas the concomitant use of nonsteroidal anti-inflammatory drugs and fentanyl as a pre-switching opioid decreased the risk. In conclusion, more than 30% of the patients underwent high-dose methadone switching and required long completion periods, suggesting that methadone switching remains challenging in Japan.

Phenolic signals for prehaustorium formation in Striga hermonthica.

Striga hermonthica is a root parasitic plant that causes considerable crop yield losses. To parasitize host plants, parasitic plants develop a specialized organ called the haustorium that functions in host invasion and nutrient absorption. The initiation of a prehaustorium, the primitive haustorium structure before host invasion, requires the perception of host-derived compounds, collectively called haustorium-inducing factors (HIFs). HIFs comprise quinones, phenolics, flavonoids and cytokinins for S. hermonthica; however, the signaling pathways from various HIFs leading to prehaustorium formation remain largely uncharacterized. It has been proposed that quinones serve as direct signaling molecules for prehaustorium induction and phenolic compounds originating from the host cell wall are the oxidative precursors, but the overlap and distinction of their downstream signaling remain unknown. Here we show that quinone and phenolic-triggered prehaustorium induction in S. hermonthica occurs through partially divergent signaling pathways. We found that ASBr, an inhibitor of acetosyringone in virulence gene induction in the soil bacterium Agrobacterium, compromised prehaustorium formation in S. hermonthica. In addition, LGR-991, a competitive inhibitor of cytokinin receptors, inhibited phenolic-triggered but not quinone-triggered prehaustorium formation, demonstrating divergent signaling pathways of phenolics and quinones for prehaustorium formation. Comparisons of genome-wide transcriptional activation in response to either phenolic or quinone-type HIFs revealed markedly distinct gene expression patterns specifically at the early initiation stage. While quinone DMBQ triggered rapid and massive transcriptional changes in genes at early stages, only limited numbers of genes were induced by phenolic syringic acid. The number of genes that are commonly upregulated by DMBQ and syringic acid is gradually increased, and many genes involved in oxidoreduction and cell wall modification are upregulated at the later stages by both HIFs. Our results show kinetic and signaling differences in quinone and phenolic HIFs, providing useful insights for understanding how parasitic plants interpret different host signals for successful parasitism.

Day-Night Oscillation of Atrogin1 and Timing-Dependent Preventive Effect of Weight-Bearing on Muscle Atrophy.

BACKGROUND: Atrogin1, which is one of the key genes for the promotion of muscle atrophy, exhibits day-night variation. However, its mechanism and the role of its day-night variation are largely unknown in a muscle atrophic context. METHODS: The mice were induced a muscle atrophy by hindlimb-unloading (HU). To examine a role of circadian clock, Wild-type (WT) and Clock mutant mice were used. To test the effects of a neuronal effects, an unilateral ablation of sciatic nerve was performed in HU mice. To test a timing-dependent effects of weight-bearing, mice were released from HU for 4 h in a day at early or late active phase (W-EAP and W-LAP groups, respectively). FINDINGS: We found that the day-night oscillation of Atrogin1 expression was not observed in Clock mutant mice or in the sciatic denervated muscle. In addition, the therapeutic effects of weight-bearing were dependent on its timing with a better effect in the early active phase. INTERPRETATION: These findings suggest that the circadian clock controls the day-night oscillation of Atrogin1 expression and the therapeutic effects of weight-bearing are dependent on its timing. FUND: Council for Science, Technology, and Innovation, SIP, "Technologies for creating next-generation agriculture, forestry, and fisheries".

Positive association between physical activity and PER3 expression in older adults.

The circadian clock regulates many physiological functions including physical activity and feeding patterns. In addition, scheduled exercise and feeding themselves can affect the circadian clock. The purpose of the present study was to investigate the relationship between physical/feeding activity and expression of clock genes in hair follicle cells in older adults. Twenty adult men (age, 68 ± 7 years, mean ± SE) were examined in this cross-sectional study. Prior to hair follicle cell collection, the participants were asked to wear a uniaxial accelerometer for one week. The timings of breakfast, lunch, and dinner were also recorded. Hair follicle cells were then collected over a 24 h period at 4 h intervals. The amplitude of PER3 expression was positively correlated with moderate and vigorous physical activity (r = 0.582, p = 0.007) and peak oxygen uptake (r = 0.481, p = 0.032), but these correlations were not observed for NR1D1 or NR1D2. No association was noted between meal times and the amplitude or the acrophase for any of these three clock genes. These findings suggest that rhythmic expression of the circadian clock gene PER3 is associated with the amount of daily physical activity and physical fitness in older adults.

Plant-Derived Polyphenols Interact with Staphylococcal Enterotoxin A and Inhibit Toxin Activity.

This study was performed to investigate the inhibitory effects of 16 different plant-derived polyphenols on the toxicity of staphylococcal enterotoxin A (SEA). Plant-derived polyphenols were incubated with the cultured Staphylococcus aureus C-29 to investigate the effects of these samples on SEA produced from C-29 using Western blot analysis. Twelve polyphenols (0.1-0.5 mg/mL) inhibited the interaction between the anti-SEA antibody and SEA. We examined whether the polyphenols could directly interact with SEA after incubation of these test samples with SEA. As a result, 8 polyphenols (0.25 mg/mL) significantly decreased SEA protein levels. In addition, the polyphenols that interacted with SEA inactivated the toxin activity of splenocyte proliferation induced by SEA. Polyphenols that exerted inhibitory effects on SEA toxic activity had a tendency to interact with SEA. In particular, polyphenol compounds with 1 or 2 hexahydroxydiphenoyl groups and/or a galloyl group, such as eugeniin, castalagin, punicalagin, pedunculagin, corilagin and geraniin, strongly interacted with SEA and inhibited toxin activity at a low concentration. These polyphenols may be used to prevent S. aureus infection and staphylococcal food poisoning.

The circadian clock controls fluctuations of colonic cell proliferation during the light/dark cycle via feeding behavior in mice.

The mammalian circadian system is controlled not only by the suprachiasmatic nucleus (SCN), but also by the peripheral clocks located in tissues such as liver, kidney, small intestine, and colon, mediated through signals such as hormones. Peripheral clocks, but not the SCN, can be entrained by food intake schedules. While it is known that cell proliferation exhibits a circadian rhythm in the colon epithelium, it is unclear how this rhythm is influenced by food intake schedules. Here, we aimed to determine the relationships between feeding schedules and cell proliferation in the colon epithelium by means of immunochemical analysis, using 5-bromo-2'-deoxyuridine (BrdU), as well as to elucidate how feeding schedules influence the colonic expression of clock and cell cycle genes, using real-time reverse-transcription PCR (qRT-PCR). Cell proliferation in the colonic epithelium of normal mice exhibited a daily fluctuation, which was abrogated in Clock mutant mice. The day/night pattern of cellular proliferation and clock gene expression under daytime and nighttime restricted feeding (RF) schedules showed opposite tendencies. While daytime RF for every 4 h attenuated the day/night pattern of cell proliferation, this was restored to normal in the Clock mutant mice under the nighttime RF schedule. These results suggest that feeding schedules contribute to the establishment of a daily fluctuation of cell proliferation and RF can recover it in Clock mutant mice. Thus, this study demonstrates that the daily fluctuation of cell proliferation in the murine colon is controlled by a circadian feeding rhythm, suggesting that feeding schedules are important for rhythmicity in the proliferation of colon cells.

Screening of tea extract and theaflavins for inhibitory effects on the biological activity and production of staphylococcal enterotoxin A.

This study aimed to develop a novel method with tea extracts and its components, to reduce the risk of foodborne illnesses caused by the bacterial toxin staphylococcal enterotoxin A (SEA). The potential effect of tea extracts, theaflavins, and epitheaflagallin on staphylococcal growth was studied. A broth microdilution method was used to determine the minimum inhibitory concentration of these samples against an SEA-producing strain, Staphylococcus aureus C-29. The following assays were performed to evaluate various effects on concentrations of no effect on staphylococcal growth. The interactions of theaflavin-rich green tea extracts (TGE), theaflavins, and epitheaflagallin to cultured S. aureus C-29 were determined using Western blot analysis. As a result, all samples suppressed the binding affinity of the anti-SEA antibody to SEA. Since these samples could react directly with SEA, we examined whether they could bind to SEA. Our results demonstrated that binding of the anti-SEA antibody to 4 theaflavins-treated SEA was inhibited in a dose-dependent manner. On the other hand, the production of SEA was significantly decreased by treatment with TGE and epitheaflagallin. Based on the finding that TGE and epitheaflagallin inhibit the production of SEA, we further examined the relative expression levels of sea toxin-encoding genes after treatment with TGE and epitheaflagallin with real-time RT-PCR. TGE and epitheaflagallin significantly supressed the gene transcription of SEA in S. aureus C-29. We then tested whether the samples block the biological activity of SEA in murine spleen cells. TGE, theaflavins, and epitheaflagallin became inactivated the biological activity of SEA. These results suggest that edible and safe compounds in tea can be used to inactivate both pathogens and toxins.

A novel ELISA system for simultaneous detection of six subclasses of anti-phospholipid antibodies for prediction of thrombotic complications among SLE patients.

BACKGROUND: Anti-phospholipid antibodies (aPLs) are frequently associated with arterial and/or venous thromboembolic complications and recurrent fetal loss in patients with systemic lupus erythematosus (SLE). We recently reported that the clinical picture of SLE apparently depends on subclasses of aPLs in the patient's sera, but the contribution of each subclass remains uncertain. METHODS: We newly developed an ELISA system for simultaneous detection of six specific categories of aPLs: anti-cardiolipin (aCL), anti-ß2-glycoprotein I (aß2GPI), anti-cardiolipin/ß2-glycoprotein I (aCL/ß2GPI), anti-phosphatidylserine (aPS), anti-prothrombin (aPT), and anti-phosphatidylserine/prothrombin (aPS/PT). They were measured in 331 patients with SLE including 63 patients with arterial thromboembolic complications, 64 with venous thromboembolic complications, and 43 with recurrent fetal loss. Lupus anticoagulant (LA) activity in their plasma was measured according to the guidelines recommended by the Subcommittee on Lupus Anticoagulant/Phospholipid-Dependent Antibodies. RESULTS: Multivariate logistic analysis revealed that the concentration of aPS/PT was most closely associated with arterial thrombosis. In contrast, the concentration of aß2GPI was most closely related to venous thrombosis. Furthermore, both aCL/ß2GPI and aPS/PT were independently associated with episodes of recurrent fetal loss. Regarding the relation between APLs and LA activity, aPS/PT, followed by aß2GPI and aPT, showed the closest association with the presence of LA activity. CONCLUSIONS: Anti-phospholipid syndrome in patients with SLE can be classified by antigenic specificities of their aPLs as to their susceptibility to arterial and/or venous thromboembolic complications or obstetric complications.

A single daily meal at the beginning of the active or inactive period inhibits food deprivation-induced fatty liver in mice.

Food deprivation (FD) induces hepatic steatosis in both rodents and humans. Although body composition, age, and sex influence hepatic triglyceride (TG) levels after FD, whether feeding patterns affect FD-induced liver TG increases is unknown. We hypothesized that restricted feeding (RF) of 1 meal per day during the active or inactive period (especially the inactive period) augments FD-induced elevation of liver TGs because RF in the inactive period impairs the circadian rhythm. Triglyceride levels and the expression of genes related to TG metabolism in the liver were examined by a bioassay and real-time reverse transcription-polymerase chain reaction, respectively. In the first experiment, when compared to nonfasted mice, mice that fasted for 24 hours showed a 1.5-fold (FD starting during the inactive period) to 3-fold (FD started during the active period) increase in liver TG levels. This experiment showed that TG levels depend upon the starting time of FD. In the second experiment, mice were given free access to food for 3 hours at the beginning of either the inactive ("supper-only") or the active ("breakfast-only") period for 2 weeks. Restricted feeding inhibited the FD-induced increases in liver and serum TG levels, serum free fatty acids, and the expression of genes related to fatty acid uptake in the liver, including fatty acid transport protein 1 (Fatp1) and 4 (Fatp4). Unexpectedly, compared to free feeding, RF during the active or inactive period resulted in resistance to FD-induced fatty liver. This is the first study to demonstrate that feeding patterns affect FD-induced TG accumulation in the mouse liver.

Controlling access time to a high-fat diet during the inactive period protects against obesity in mice.

Free feeding (FF) with a high fat diet (HFD) causes excessive body weight gain, whereas restricted feeding (RF) with a HFD attenuates body weight gain. The effects of timing of feeding with a HFD (day vs. night) and feeding duration on energy homeostasis have not yet been investigated. In this study, we fed mice a HFD or a normal diet (ND) twice a day, during their active and inactive periods, on a schedule. The amount of food was regulated by feeding duration (2, 4 or 8 h). First, we investigated the effects of 4-h RF during active-inactive periods (ND-ND, HFD-HFD, ND-HFD or HFD-ND). Among all the 4-h RF groups, mice consumed almost the same amount of calories as those in the FF[ND] group, even those fed a HFD. Body weight and visceral fat in these three groups were lower than that in the FF[HFD] group. Second, we investigated the effects of RF duration. Body weight and visceral fat were higher in the 8-h groups than in the 4-h groups. Body weight and visceral fat were higher in the 2-h groups than in the 4-h groups even though the 2-h groups had less food. Third, we investigated the effects of eating a HFD during the inactive period, when RF duration was extended (2, 6 or 12 h). Mice were fed with a HFD during the inactive period for 2 h and fed with a ND during the active period for 2, 6 or 12 h. Body weight and visceral fat in these mice were comparable to those in the FF[ND] mice. The results of our first set of experiments suggest that 4-h RF was an adequate feeding duration to control the effect of a HFD on obesity. The results of our second set of experiments suggest 2-h RF (such as speed-eating) and 8-h RF, representative of eating disorders, are unhealthy feeding patterns related to obesity. The results of our third set of experiments suggest that eating a HFD for a short period during the night does not affect body weight and visceral fat. Taken together, these results indicate that consideration to feeding with a HFD during the inactive period and restricting eating habits relieve the risks of body weight gain and visceral fat accumulation.