Impact of Plant and Animal Protein-Based Meals on Serum Fibroblast Growth Factor-23 Levels in Healthy Young Men: A Randomized Crossover Trial.

Fibroblast growth factor-23 (FGF23) is a phosphaturic hormone secreted by osteocytes in response to dietary phosphate intake. An increase in FGF23 level is an indicator of excess phosphate intake relative to the residual nephron number. Therefore, avoiding excessive phosphate intake and inhibiting the elevation of serum FGF23 levels are important to preserve the number of functional nephrons. This randomized crossover trial aimed to determine the potential differences in the impacts on serum FGF23 levels between plant protein and animal protein-based meals in individuals with normal renal function. Nine young men were administered plant (no animal protein) or animal protein-based meals (70% of their protein was from animal sources) with the same phosphate content. The test meals consisted of breakfast, lunch, and dinner. Blood samples were collected in the morning, after overnight fasting, and before and after eating the test meals (for two consecutive days at the same hour each day). Furthermore, a 24-h urine sample was obtained on the day the test meal was consumed. No significant interactions were found among serum phosphate, calcium, and 1,25-dihydroxyvitamin D levels. However, after eating plant protein-based meals, serum FGF23 levels decreased and serum intact parathyroid hormone levels increased (interaction, p<0.05). Additionally, urine 24-h phosphate excretion tended to be lower in individuals consuming plant protein-based meals than in those consuming animal protein-based meals (p=0.06). In individuals with normal renal function, plant protein-based meals may prevent an increase in serum FGF23 levels and kidney damage caused by phosphate loading.

Effects of plant- and animal-based-protein meals for a day on serum nitric oxide and peroxynitrite levels in healthy young men.

Plant-based diets that replace animal-based proteins with plant-based proteins have received increased attention for cardiovascular protection. Nitric oxide (NO) plays an essential role in the maintenance of endothelial function. However, under higher oxidative stress, NO generation produces peroxynitrite, a powerful oxidant and vasoconstrictor. Diet-replaced protein sources has been reported to decrease oxidative stress. However, the effects of plant-based protein on NO and peroxynitrite have not yet been clarified. Therefore, this study aimed to compare the effects of plant- and animal-based-protein meals for a day on NO, peroxynitrite, and NO/peroxynitrite balance. A crossover trial of two meal conditions involving nine healthy men was performed. Participants ate standard meals during day 1. On day 2, baseline measurements were performed and the participants were provided with plant-based-protein meals or animal-based-protein meals. The standard and test meals consisted of breakfast, lunch, and dinner and were designed to be isocaloric. Plant-based-protein meals contained no animal protein. Blood samples were collected in the morning after overnight fasting before and after the test meals consumption. In the plant-based-protein meal condition, serum NOx levels (the sum of serum nitrite and nitrate) significantly increased, while serum peroxynitrite levels did not change significantly. Animal-based-protein meals significantly increased serum peroxynitrite levels but showed a trend of reduction in the serum NOx levels. Furthermore, serum NO/peroxynitrite balance significantly increased after plant-based-protein meals consumption, but significantly decreased after animal-based-protein meals consumption. These results suggest that, compared with animal-based-protein meals, plant-based-protein meals increase NO levels and NO/peroxynitrite balance, which reflects increased endothelial function.

Effects of lactotripeptide ingestion and physical activity intervention on the fatigue status of middle-aged and older adults: a randomized controlled trial.

This randomized controlled trial aimed to investigate the effects of eight weeks of lactotripeptide (LTP) ingestion, physical activity (PA) intervention, and combined intervention on the fatigue status of middle-aged and older adults. A total of 78 middle-aged and older adults (63 ± 8 years of age) were randomly assigned to four groups: placebo, LTP, placebo with PA intervention (placebo + PA), and LTP with PA intervention (LTP + PA). All participants ingested the placebo or LTP tablets daily (three tablets/day). The placebo + PA and LTP + PA groups participated in a weekly supervised exercise class and were instructed to increase their moderate- to vigorous-intensity PA at home. The visual analog scale, Brief Fatigue Inventory, Profile of Mood States second edition (POMS2), and Beck Depression Inventory second edition (BDI-II) were administered before and after the intervention. No significant interactions or main effects were observed between LTP ingestion and PA intervention on any of the fatigue scales. The main-effect analyses revealed that the PA intervention improved the total mood disturbance score of the POMS2 (F = 5.22, P = 0.03) and BDI-II score (F = 4.81, P = 0.03). After the post hoc paired comparisons, the total mood disturbance and BDI-II scores improved more with the combined intervention than with the PA intervention alone (percentage difference between the effect of combined intervention and PA intervention alone was 3.7% for total mood disturbance score and 13.7% for BDI-II score). The present study suggests that eight weeks of LTP ingestion and PA intervention did not have a significant effect on fatigue status. However, the PA intervention improved mood status and depressive symptoms, and these effects were enhanced by LTP ingestion.

Genetic polymorphisms related to muscular strength and flexibility are associated with artistic gymnastic performance in the Japanese population.

This study aimed to examine how genetic polymorphisms related to muscular strength and flexibility influence artistic gymnastic performance in an attempt to identify a novel polymorphism associated with flexibility. In study 1, the passive straight-leg-raise (PSLR) score and aromatase gene CYP19A1 rs936306 polymorphism, a key enzyme for estrogen biosynthesis, were assessed in 278 individuals. In study 2, athletes (281 gymnasts and 1908 other athletes) were asked about their competition level, and gymnasts were assessed using the difficulty score (D-score) for each event. Muscular strength- (ACTN3 R577X rs1815739 and ACE I/D rs4341) and flexibility-related (ESR1 rs2234693 T/C and CYP19A1 rs936306 C/T) genetic polymorphisms were analyzed. In study 1, males with the CYP19A1 CT + TT genotype showed significantly higher PSLR scores than those with the CC genotype. In study 2, male gymnasts with the R allele of ACTN3 R577X showed a correlation with the floor, rings, vault, and total D-scores. In addition, male gymnasts with the C allele of ESR1 T/C and T allele of CYP19A1 C/T polymorphisms were correlated with the pommel horse, parallel bars, horizontal bar, and total D-scores. Furthermore, genotype scores of these three polymorphisms correlated with the total D-scores and competition levels in male gymnasts. In contrast, no such associations were observed in female gymnasts. Our findings suggest that muscular strength- and flexibility-related polymorphisms play important roles in achieving high performance in male artistic gymnastics by specifically influencing the performance of events that require muscular strength and flexibility, respectively.HighlightsEstrogen-related CYP19A1 polymorphism is a novel determinant of flexibility in males.Muscular strength- and flexibility-related polymorphisms play important roles in high performance in male artistic gymnastics.Genotypes of ACTN3 R577X, ESR1 rs2234693, and CYP19A1 rs936306 may contribute to training plan optimization and event selection in artistic gymnastics.

The psychological distress and suicide-related ideation in hospital workers during the COVID-19 pandemic: Second results from repeated cross-sectional surveys.

The COVID-19 pandemic has been affecting the mental health of hospital workers. During the prolonged pandemic, hospital workers may experience much more severe psychological distress, leading to an increased risk of suicide. This study aimed to investigate changes in psychological effects on hospital workers over 12 months from the beginning of the pandemic and clarify factors associated with psychological distress and suicide-related ideation 1-year after the pandemic's beginning. These repeated, cross-sectional surveys collected demographic, mental health, and stress-related data from workers in 2 hospitals in Yokohama, Japan. The first survey, conducted in March-April 2020, contained the 12-item General Health Questionnaire (GHQ-12) assessing general distress and the Impact of Event Scale-Revised (IES-R) assessing event-related distress. In the second survey in March 2021, hospital workers at the same two hospitals were reassessed using the same questionnaire, and Item 9 of the Patient Health Questionnaire (PHQ-9) was added to assess their suicide-related ideation. The findings of the first and second surveys revealed that the average score of GHQ-12 (3.08 and 3.73, respectively), the IES-R total score (6.8 and 12.12, respectively), and the prevalence rates of severe general distress (35.0% and 44.0%, respectively) and severe event-related distress (7.0% and 17.1%, respectively) deteriorated. The second survey showed that 8.6% of the hospital workers were experiencing suicide-related ideation. Both the general and event-related distress were associated with suicide-related ideation. In these surveys, mental health outcomes among the hospital workers deteriorated over one year from the pandemic's beginning, and their severe psychological distress was the risk factor for the suicide-related ideation. Further studies are needed to compare the psychological effects on hospital workers during and after the prolonged pandemic and to explore appropriate measures to support hospital workers' mental health.

The psychological effects of COVID-19 on hospital workers at the beginning of the outbreak with a large disease cluster on the Diamond Princess cruise ship.

The aim of the present study was to investigate the psychological effects of the COVID-19 outbreak and associated factors on hospital workers at the beginning of the outbreak with a large disease cluster on the Diamond Princess cruise ship. This cross-sectional, survey-based study collected demographic data, mental health measurements, and stress-related questionnaires from workers in 2 hospitals in Yokohama, Japan, from March 23, 2020, to April 6, 2020. The prevalence rates of general psychological distress and event-related distress were assessed using the 12-item General Health Questionnaire (GHQ-12) and the 22-item Impact of Event Scale-Revised (IES-R), respectively. Exploratory factor analysis was conducted on the 26-item stress-related questionnaires. Multivariable logistic regression analysis was performed to identify factors associated with mental health outcomes for workers both at high- and low-risk for infection of COVID-19. A questionnaire was distributed to 4133 hospital workers, and 2697 (65.3%) valid questionnaires were used for analyses. Overall, 536 (20.0%) were high-risk workers, 944 (35.0%) of all hospital workers showed general distress, and 189 (7.0%) demonstrated event-related distress. Multivariable logistic regression analyses revealed that 'Feeling of being isolated and discriminated' was associated with both the general and event-related distress for both the high- and low-risk workers. In this survey, not only high-risk workers but also low-risk workers in the hospitals admitting COVID-19 patients reported experiencing psychological distress at the beginning of the outbreak.

Radiosensitizing Effect of 5-Aminolevulinic Acid and Protoporphyrin IX on Carbon-ion Beam Irradiation.

BACKGROUND/AIM: Carbon-ion beam is one of the most advanced radiations used for cancer treatment. However, there are tumors that are difficult to suppress with carbon-ion beam alone, thus necessitating development of drugs that can enhance its therapeutic effect. In this regard, the radiosensitizing effect of 5-aminolevulinic acid (ALA) and protoporphyrin IX (PpIX), that is a metabolic intermediate of ALA, on carbon-ion beam was investigated. MATERIALS AND METHODS: Radiosensitizing activity, mitochondrial ROS and DNA double-strand break production of ALA and PpIX were evaluated by irradiation with 1.0 or 1.5-Gy carbon-ion beam to mouse mammary EMT6 tumor cells. RESULTS: Combination of carbon-ion beam and ALA or PpIX showed a significant enhancement of its cytotoxic activity through a significant increase in ROS production in mitochondria. Furthermore, the combined activity of carbon-ion beam and ALA resulted in a significant increase in DNA double-strand breakage. CONCLUSION: ALA selectively accumulates in the mitochondria and PpIX synthesized from ALA reacts with carbon-ion beam to produce ROS that exert antitumor activity.

Germline stem cells and follicular renewal in the postnatal mammalian ovary.

A basic doctrine of reproductive biology is that most mammalian females lose the capacity for germ-cell renewal during fetal life, such that a fixed reserve of germ cells (oocytes) enclosed within follicles is endowed at birth. Here we show that juvenile and adult mouse ovaries possess mitotically active germ cells that, based on rates of oocyte degeneration (atresia) and clearance, are needed to continuously replenish the follicle pool. Consistent with this, treatment of prepubertal female mice with the mitotic germ-cell toxicant busulphan eliminates the primordial follicle reserve by early adulthood without inducing atresia. Furthermore, we demonstrate cells expressing the meiotic entry marker synaptonemal complex protein 3 in juvenile and adult mouse ovaries. Wild-type ovaries grafted into transgenic female mice with ubiquitous expression of green fluorescent protein (GFP) become infiltrated with GFP-positive germ cells that form follicles. Collectively, these data establish the existence of proliferative germ cells that sustain oocyte and follicle production in the postnatal mammalian ovary.

Carbonyl stress and detoxification ability in the male genital tract and testis of rats.

Carbonyl compounds, which are naturally produced and augmented under oxidative stress, have deleterious effects on the reproductive system. The aldo-keto reductase (AKR) family of enzymes catalyze the reductive detoxification of various carbonyl compounds in an NADPH-dependent manner. To elucidate involvement of AKR in detoxification of endogenously produced carbonyls in the male reproductive system, we investigated the differential expression and tissue localization of aldehyde reductase (ALR) and protein adducts produced by reaction with lipid peroxidation products. A strong immunoreactivity to an anti-ALR antibody was observed in the epithelia of the epididymis, vas deferens, seminal vesicle, and prostate gland. Virtually the same cells were stained with a monoclonal antibody (mAb) 5F6, raised against an acrolein-modified protein. In the testis, however, mAb5F6 specifically stained the nuclei of somatic cells and less differentiated spermatogenic cells. While acrolein inactivated glutathione reductase, an enzyme involved in recycling oxidized glutathione, AKR activity was affected at the high concentration only. The colocalization of lipid peroxidation products and AKR in the epithelia of the male genital tract indicates that these tissues are exposed to oxidative stress and possess a protective system coordinately.

Colocalization of polyol-metabolizing enzymes and immunological detection of fructated proteins in the female reproductive system of the rat.

The expression of aldose reductase (AR) and sorbitol dehydrogenase (SDH), which, in concert, catalyze the conversion of glucose to fructose via sorbitol, in the rat ovary, oviduct, and uterus, was investigated by immunohistochemical and biochemical analyses. The activities and protein levels of AR and SDH were higher in the ovary than in the oviduct and uterus. A strong immunoreactivity to the anti-AR antibody was observed in granulosa cells and epithelia of the oviduct, endometrium, and endometrial glands, and virtually the same tissues were strongly stained with the anti-SDH antibody. The application of an anti-fructated lysine antibody, which detects an adduct of fructose with the epsilon-amino group of lysine in proteins, in this study detected marked staining mainly in the egg and luminal surface of the oviductal epithelia. Collectively, these data indicate that fructose is produced by coordinately expressed AR and SDH in the egg and epithelia of the oviduct and suggest that the resulting sorbitol and fructose can be used as energy sources for spermatozoa motility during the fertilization process. The abundance of AR compared with SDH suggests that it also plays an additional role in the reproductive system, which might include a source of reducing power and protection against toxic carbonyl compounds.

Concerted changes in the YB2/RYB-a protein and protamine 2 messenger RNA in the mouse testis under heat stress.

Translation of a number of mRNAs is under strict regulation via RNA-binding proteins in the spermatogenic cells of testes. A family of Y-box binding proteins represents promising candidates for these presently uncharacterized RNA-binding proteins. The effects of heat stress on the expression of a Y-box binding protein, YB2/RYB-a, and mouse protamine 2 (mP2) were investigated in cultured spermatogenic cells and mouse testes by immunoblot and Northern blot analyses. Localization and alterations in the expression of the YB2/RYB-a protein and the mP2 mRNA in heat-stressed testes were examined by immunohistochemistry and in situ hybridization, respectively. Levels of the YB2/RYB-a protein in spermatogenic cells decreased rapidly as the result of exposure to higher temperature, 37 degrees C or 43 degrees C, compared with the scrotal temperature, 32.5 degrees C, under the culture conditions used. In experimental cryptorchidism, levels of the YB2/RYB-a protein were decreased after Day 10, while the mRNA levels were affected only slightly. The levels of the mP2 mRNA were also decreased and about comparable with those of the YB2/RYB-a protein. Exposure of the lower abdomen to a high temperature, 43 degrees C for 15 min, also damaged the testis and led to a decrease in YB2/RYB-a protein and the mP2 mRNA levels in a coordinated manner. Because YB2/RYB-a is proposed to function as a stabilizer of mP2 mRNA, the perturbation of YB2/RYB-a by heat stress could account for the decline of the mP2 mRNA in elongated spermatids.

Localization and physiological implication of aldose reductase and sorbitol dehydrogenase in reproductive tracts and spermatozoa of male rats.

The polyol metabolizing pathway, which consists of two enzymes, aldose reductase (AR) and sorbitol dehydrogenase (SDH), converts glucose to fructose. The enzymatic activities, expression, and localization of AR and SDH were studied in reproductive tracts and spermatozoa of male rats by immunohistochemistry, Western blotting, and enzyme assays. Immunoreactivity to an AR antibody was observed mainly in epithelia of epididymis, seminal vesicle, vas deferens, and prostate gland in adult rats. Similar staining profiles were observed for these tissues when an SDH antibody was used. However, in testis, the cells that express these 2 enzymes differed; whereas AR was expressed in Sertoli cells and to lesser extent in spermatogenic cells, SDH was detected in spermatogenic cells of seminiferous tubules. This cell type-specific gene expression was confirmed in primary cultured cells isolated from rat testes. SDH protein levels were higher during spermatid elongation, and large amounts of SDH were carried over to the spermatozoa. Because one of the functions of members of the aldo-keto reductase superfamily is to detoxify harmful carbonyl compounds, an intrinsic function of AR in Sertoli cells may be to catalyze the reduction of cytotoxic metabolites, such as lipid peroxidation products and steroid hormones, which are produced during spermatogenesis. Because uterine fluid and seminal plasma both contain sorbitol, it is likely that SDH in spermatozoa converts sorbitol to fructose for use as an energy source.

Eight-hydroxy-2'-deoxyguanosine in granulosa cells is correlated with the quality of oocytes and embryos in an in vitro fertilization-embryo transfer program.

OBJECTIVE: To determine the effects of oxidative stress on the quality of oocytes and embryos, 8-hydroxy-2'-deoxyguanosine (8-OHdG) in granulosa cells was quantitatively studied during an in vitro fertilization and embryo transfer (IVF-ET) program. DESIGN: Immunocytochemical staining of 8-OHdG in granulosa cells was quantitatively estimated using a charge-coupled device camera and analyzed using the National Institute of Health Image (NIH Image) freeware on a computer . SETTING: Obstetrics and gynecology department in a university hospital. PATIENT(S): Ninety-six infertile couples undergoing IVF-ET treatment and intracytoplasmic sperm injection (IVF, n = 72; intracytoplasmic sperm injection, n = 24). INTERVENTION(S): Oocytes, granulosa cells, and follicular fluids were collected 35-36 hours after the administration of hCG. MAIN OUTCOME MEASURE(S): 8-OHdG indices were obtained for mural [8-OHdG index (m)] and cumulus [8-OHdG index (c)] granulosa cells. RESULT(S): A negative correlation between the fertilization rate and both 8-OHdG indices (c and m) was found. The rate of production of good embryos also showed a negative correlation with the 8-OHdG index (m) and the 8-OHdG index (c). Negative correlations between the 8-OHdG index (c) and E2 levels in follicular fluid were observed. Endometriosis patients showed a higher 8-OHdG index (c) than did patients with other infertility causes, such as tubal, male factor, and unknown. CONCLUSION(S): Oxidative stress in granulosa cells lowered fertilization rates and subsequently led to a decrease in the quality of embryos. The quality of oocytes for endometriosis patients was impaired by the presence of 8-OHdG. This might be one causative factor in infertility in endometriosis patients.

Epithelia-mesenchyme interaction plays an essential role in transdifferentiation of retinal pigment epithelium of silver mutant quail: localization of FGF and related molecules and aberrant migration pattern of neural crest cells during eye rudiment formation.

Homozygotes of the quail silver mutation, which have plumage color changes, also display a unique phenotype in the eye: during early embryonic development, the retinal pigment epithelium (RPE) spontaneously transdifferentiates into neural retinal tissue. Mitf is considered to be the responsible gene and to function similarly to the mouse microphthalmia mutation, and tissue interaction between RPE and surrounding mesenchymal tissue in organ culture has been shown to be essential for the initiation of the transdifferentiation process in which fibroblast growth factor (FGF) signaling is involved. The immunohistochemical results of the present study show that laminin and heparan sulfate proteoglycan, both acting as cofactors for FGF binding, are localized in the area of transdifferentiation of silver embryos much more abundantly than in wild-type embryos. More intense immunohistochemical staining with FGF-1 antibody, but not with FGF-2 antibody, is also found in the neural retina, RPE, and choroidal tissue of silver embryos than in wild-type embryos. HNK-1 immunohistochemistry revealed that clusters of HNK-1-positive cells (presumptive migrating neural crest cells) are frequently located around the developing eyes and in the posterior region of the silver embryonic eye. Finally, chick-quail chimerical eyes were made by grafting silver quail optic vesicles to chicken host embryos: in most cases, no transdifferentiation occurs in the silver RPE, but in a few cases, transdifferentiation occurs where silver quail cells predominate in the choroid tissue. These observations together with our previous in vitro study indicate that the silver mutation affects not only RPE cells but also cephalic neural crest cells, which migrate to the eye rudiment, and that these crest cells play an essential role in the transdifferentiation of RPE, possibly by modifying the FGF signaling pathway. The precise molecular mechanism involved in RPE-neural crest cell interaction is still unknown, and the quail silver mutation is considered to be a good experimental model for studying the role of neural crest cells in vertebrate eye development.

The expression of glutathione reductase in the male reproductive system of rats supports the enzymatic basis of glutathione function in spermatogenesis.

Glutathione reductase (GR) recycles oxidized glutathione (GSSG) by converting it to the reduced form (GSH) using an NADPH as the electron source. The function of GR in the male genital tract of the rat was examined by measuring its enzymatic activity and examining the gene expression and localization of the protein. Levels of GR activity, the protein, and the corresponding mRNA were the highest in epididymis among testes, vas deferens, seminal vesicle, and prostate gland. The localization of GR, as evidenced by immunohistochemical techniques, reveals that it exists at high levels in the epithelia of the genital tract. In testis, GR is mainly localized in Sertoli cells. The enzymatic activity and protein expression of GR in primary cultured testicular cells confirmed its predominant expression in Sertoli cells. Intracellular GSH levels, expressed as mol per mg protein, was higher in spermatogenic cells than in Sertoli cells. As a result of these findings, the effects of buthionine sulfoximine (BSO), an inhibitor for GSH synthesis, and 1,3-bis(2-chlorethyl)-1-nitrosourea (BCNU), an inhibitor for GR, on cultured testicular cells were examined. Sertoli cells were prone to die as the result of BCNU, but not BSO treatment, although intracellular levels of GSH declined more severely with BSO treatment. Spermatogenic cells were less sensitive to these agents than Sertoli cells, which indicates that the contribution of these enzymes is less significant in spermatogenic cells. The results herein suggest that the GR system in Sertoli cells is involved in the supplementation of GSH to spermatogenic cells in which high levels of cysteine are required for protamine synthesis. In turn, the genital tract, the epithelia of which are rich in GR, functions in an antioxidative manner to protect sulfhydryl groups and unsaturated fatty acids in spermatozoa from oxidation during the maturation process and storage.

Endometriosis and oocyte quality.

Endometriosis is associated with marked subfertility and various causes for this subfertility have been previously studied. The poor quality of oocytes has been suggested as one possible cause. In this study, we evaluated the quality of oocytes by examining the status of granulosa cells surrounding the oocyte. For this purpose, we analysed the incidence of apoptosis, changes in cell cycle, and oxidative stress in the granulosa cells. Endometriosis patients had a higher apoptotic incidence, more alterations of the cell cycle, and a higher incidence of oxidative stress than patients with any of the other infertility causes (tube, male, and idiopathic factors). These changes might affect oocyte quality, and thus fertility in endometriosis patients.