Josai University

ABSTRACT Aim Schizonepeta spike, the dried spikes of Schizonepeta tenuifolia , are traditionally evaluated based on floret density. However, the chemical basis for this criterion remains unclear. This study aimed to provide scientific insight into this traditional quality evaluation by clarifying the association between floret density (floret‐to‐spike ratio) and pulegone content in whole spikes, and the localization of compounds between florets and rachises. Methods Two accessions of S. tenuifolia were cultivated at six sites in Japan and analyzed by LC‐Q‐TOF‐MS. Correlation analysis was performed between the floret‐to‐spike ratio and pulegone content in whole spikes. Additionally, principal component analysis (PCA) was performed to characterize the localization of compounds between florets and rachises, and the relative abundances of major compounds were compared between them. Results In whole spikes, pulegone content tended to increase with a higher floret‐to‐spike ratio. The PCA based on the comprehensive compounds showed that florets and rachises separated into distinct groups, regardless of cultivation site or accession. Florets showed higher levels of bioactive compounds, including pulegone, luteoloside, and apigetrin, whereas rachises showed higher hesperidin levels than other parts. Conclusion Floret density of Schizonepeta spikes, as described in traditional quality evaluation, was found to be related to pulegone content, which tends to increase as the floret density becomes higher. Moreover, florets were characterized by higher levels of bioactive compounds, including luteoloside and apigetrin, and this localization suggests that the accumulation of these compounds increases in spikes with dense florets. These findings provide chemical insights into the traditional quality evaluation of Schizonepeta spikes.

Colonic contraction motility, composed of colonic motor complexes (CMCs) and giant migrating contractions (GMCs), is regulated through the coordinated integration of hormonal signals, the nervous system and intraluminal cues. Abnormalities in colonic function and motility can result in conditions such as constipation or diarrhea. It is believed that brain regions involved in regulating colonic motility play a role in colonic dysfunction observed under stress conditions and in Parkinson's disease. However, the detailed central mechanisms underlying colonic motility regulation remain unclear. This study aimed to elucidate the role of locus coeruleus (LC) controlling colonic motility using the Suncus murinus (suncus), an animal model for gastrointestinal motility research. Fluorescent immunohistochemical analysis revealed a significant increase in the number of c-Fos-positive neurons in the LC following spontaneous GMCs, and 64% of these c-Fos-positive neurons were identified as tyrosine hydroxylase (TH)-expressing neurons. 24-h measurements of colonic motility in suncus treated with DSP-4, a neurotoxin specific to noradrenergic neurons in the LC, showed that the DSP-4-treated group exhibited an increased number of GMC occurrences during the dark phase compared to the vehicle-treated group, but not during the light phase. Furthermore, α2 adrenergic receptor agonist administration decreased number of total GMC occurrences during the light phase but not dark phase. These findings suggest that, while TH neurons in the LC are not directly required in GMC generation, they may act as modulators that inhibit GMC frequency and rhythmicity.

Abstract In high-speed rotating equipment such as turbomachinery, low-loss, low-wear, and low-leakage sealing technology is needed to achieve higher efficiency, longer service life, and lower environmental impact. The authors have proposed a hydrodynamic mechanical face seal based on “gas–liquid hybrid lubrication” technology, which maintains a noncontacting gap between sliding surfaces from very low speed rotation immediately after startup to very high speed rotation, and are investigating its application to various high-speed rotating equipment. The gas–liquid hybrid lubrication technology is a new technology that uses liquid hydrodynamic lubrication to maintain a noncontacting state at very low speeds during startup and stop and automatically transitions to gas lubrication at high speeds and operates with lower losses compared to liquid lubrication. Numerical analysis has shown the lubrication characteristics of this seal. Then rotating tests were conducted to evaluate the sliding surface temperature of the new technology in comparison with conventional seals, simulating the environment of an aircraft gearbox. The results indicated that the sliding surface temperature did not increase from low-speed to high-speed rotation, and it was also experimentally confirmed that the seals operated stably and without contact. Furthermore, no leakage was observed, and good sealing characteristics were confirmed. These results demonstrate the feasibility of a seal that achieves low loss, long life, and low leakage when applied to aircraft gearboxes.

Plant-derived nanoparticles (PdNPs) have garnered increasing attention as versatile tools for nucleic acid delivery, and they have been investigated for the transdermal delivery of encapsulated nucleic acids. However, not all PdNPs have high skin penetration enhancement ability. Surface modification of PdNPs with cell penetration peptides (CPPs) can enable skin penetration, with the Tat-peptide selected as a suitable CPP. In the present study, the feasibility of enhancing skin penetration was evaluated using grapefruit-derived nanoparticles (GNPs) modified with stearylated Tat-peptide (STR-Tat). The surface modification of GNPs with STR-Tat was conducted using a simple mixing method of synthesized STR-Tat with GNPs. Changes in particle size and zeta-potential of STR-Tat-GNPs were measured. In addition, in vivo skin penetration experiments were conducted as well as investigating cellular uptake and cell toxicity to determine the effect of surface modification on the skin penetration ability of GNPs. A positive zeta potential was observed for STR-Tat-GNPs, whereas GNPs had a negative zeta potential. In addition, increased cellular uptake was confirmed for STR-Tat-GNPs without extensive cell toxicity. DiI-derived fluorescence was observed in hair follicles and at deeper sites of the dermis when DiI-labelled STR-Tat-GNPs were applied on mouse back skin in in vivo conditions. A simple mixing procedure of STR-Tat enhanced the skin penetration ability of a lipophilic dye initially associated with GNPs without cellular toxicity. Therefore, this approach may be applicable for providing plant-derived particles, which are expected to be an effective vehicle for nucleic acid delivery with high skin penetration ability.

The mechanisms by which erythropoietin (EPO) promotes hepatocyte proliferation in primary cultures of adult rat hepatocytes were studied. EPO stimulated cell proliferation in a time- and dose-dependent manner, significantly increasing the number of hepatocyte nuclei and DNA synthesis. EPO-induced hepatocyte proliferation was completely suppressed by specific inhibitors targeting Janus kinase 2 (JAK 2), phospholipase C (PLC), protein kinase C (PKC), intracellular Ca2+ mobilization, mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK), and mammalian target of rapamycin (mTOR). In contrast, inhibition of signal transducer and activator of transcription 3/5 (STAT 3/5) or granule secretion had no effect, indicating that EPO acts through a pathway distinct from the classical JAK2-STAT signaling pathway. Western blot analysis showed rapid phosphorylation of ERK 2, but not ERK 1, following EPO stimulation. In addition, EPO induced phosphorylation of PLC and C-rapidly accelerated fibrosarcoma (C-Raf), with PKC acting downstream of PLC and upstream of C-Raf. In contrast, intracellular Ca2+ concentration and activated Ras were transiently increased in hepatocytes after EPO stimulation, and EPO-induced activated Ras was significantly suppressed by the specific PKC inhibitor GF109203X. These results indicate that EPO engages the JAK2/PLC/PKC-Ca2+ signaling cascade, leading to the sequential activation of Ras, C-Raf, and ERK2, ultimately promoting hepatocyte proliferation in vitro.

The 3 factors of the classic model (maximal oxygen uptake [V·O2max], fractional utilization of V·O2max at the anaerobic threshold, and running economy [RE]) are well known to be the determinants of isolated distance running performance. However, no previous studies appear to have investigated the relationship between all 3 factors and running performance in the Olympic-distance triathlon (ODT). We therefore investigated this relationship by conducting 2 studies. In study I, the relationship between the 3 factors of the classic model and running performance in actual ODT races was investigated in 16 male triathletes. In study II, the relationship between the three factors and running performance in simulated ODT races with controlled exercise intensities, pedaling cadence, and carbohydrate intake during the swim and bike legs was investigated in 8 male triathletes. The 3 factors were quantified using a treadmill incremental test following the same protocol in each study. Simple correlation and multiple regression analyses were performed using the forced entry method. The independent variables were the 3 factors of the classic model, and the dependent variable was running performance in the ODT races. In study I, no significant correlation was found between the 2 measurements (p > 0.05). Furthermore, no significant multiple correlation coefficient was obtained (R < 0.54, p > 0.05), and < 10.7% of the running performance was attributable to the 3 factors. In study II, by contrast, a significant correlation was found between RE and running performance (r = 0.79, p = 0.02). In addition, a significant multiple correlation coefficient was obtained (R = 0.91, p = 0.05), and 69.9% of the running performance in the simulated ODT race was attributable to the three factors. In conclusion, we suggest that in the ODT the 3 factors of the classic model explain interindividual variation in running performance. However, in an actual ODT race, the relationship between the 3 factors and running performance may weaken owing to the residual effects of prior swimming and cycling.

ABSTRACTCOX7RP is a critical factor that assembles mitochondrial respiratory chain complexes into supercomplexes, which is considered to modulate energy production efficiency. Whether COX7RP contributes to metabolic homeostasis and lifespan remains elusive. We here observed that COX7RP‐transgenic (COX7RP‐Tg) mice exhibit a phenotype characterized by a significant extension of lifespan. In addition, metabolic alterations were observed in COX7RP‐Tg mice, including lower blood glucose levels at 120 min during the glucose tolerance test (GTT) without a significant difference in the area under the curve (AUC), as well as reduced serum triglyceride (TG) and total cholesterol (TC) levels. Moreover, COX7RP‐Tg mice exhibited elevated ATP and nicotinamide adenine dinucleotide levels, reduced ROS production, and decreased senescence‐associated β‐galactosidase levels. Single‐nucleus RNA‐sequencing (snRNA‐seq) revealed that senescence‐associated secretory phenotype genes were downregulated in old COX7RP‐Tg white adipose tissue (WAT) compared with old WT WAT, particularly in adipocytes. This study provides a clue to the role of mitochondrial respiratory supercomplex assembly factor COX7RP in resistance to aging and longevity extension.

ZIP14/SLC39A14, a membrane-bound metal transporter, is essential for systemic metal homeostasis and has been implicated in inflammatory and metabolic disorders, including cancer-associated cachexia. Despite its biological and therapeutic significance, no selective inhibitors have been identified. Here, we identify 1-phenyl-8-(2-phenylethyl)-1,3,8-triazaspiro[4.5]decan-4-one (PPTD) as the first selective small-molecule inhibitor of ZIP14. PPTD efficiently blocks ZIP14-mediated uptake of zinc, iron, manganese, and cadmium, while sparing the closely related transporter ZIP8/SLC39A8. Mechanistically, PPTD binds specifically to a pocket formed at the dimer interface of ZIP14, as revealed by AlphaFold3 structural prediction, ligand-interaction profiling, structure-activity analyses, and site-directed mutagenesis, providing direct evidence for a targeted inhibition mechanism. ZIP14-driven metal influx promotes reactive oxygen species and lipid peroxidation, leading to cytotoxicity, which PPTD effectively reverses. In vivo , PPTD ameliorates major features of cancer cachexia in mice, including weight loss, reduced survival, muscle wasting, impaired locomotor activity, and disease progression. PPTD thus provides both a chemical probe to dissect ZIP14 function and a potential therapeutic candidate for cancer cachexia, establishing a foundation for the development of therapies targeting ZIP14-mediated metal dysregulation.