Maiko Kitajima

Lack of Awareness among Future Medical Professionals about the Risk of Consuming Hidden Phosphate-Containing Processed Food and Drinks

Phosphate toxicity is an important determinant of mortality in patients with chronic kidney disease (CKD), particularly those undergoing hemodialysis treatments. CKD patients are advised to take a low phosphate-containing diet, and are additionally prescribed with phosphate-lowering drugs. Since these patients usually seek guidance from their physicians and nurses for their dietary options, we conducted a survey to determine the levels of awareness regarding the high phosphate content in commercially processed food and drinks among medical and nursing students at the Hirosaki University School of Medicine in Japan. For this survey, 190 medical and nursing students (average age 21.7±3 years) were randomly selected, and provided with a list of questions aimed at evaluating their awareness of food and drinks containing artificially added phosphate ingredients. While 98.9% of these students were aware of the presence of sugar in commercially available soda drinks, only 6.9% were aware of the presence of phosphate (phosphoric acid). Similarly, only 11.6% of these students were aware of the presence of phosphate in commercially processed food, such as hamburgers and pizza. Moreover, around two thirds of the surveyed students (67.7%) were unaware of the harmful effects of unrestricted consumption of phosphate-containing food and drinks. About 28% of the surveyed students consume such “fast food” once a week, while 40% drink at least 1∼5 cans of soda drinks/week. After realizing the potential long-term risks of consuming excessive phosphate-containing food and drinks, 40.5% of the survey participants considered reducing their phosphate intake by minimizing the consumption of commercially processed “fast food” items and soda drinks. Moreover, another 48.4% of students showed interest in obtaining more information on the negative health effects of consuming excessive amounts of phosphate. This survey emphasizes the need for educational initiative to raise awareness of the health risks posed by excessive consumption of phosphate additives.

Inadequate Awareness among Chronic Kidney Disease Patients Regarding Food and Drinks Containing Artificially Added Phosphate

Hyperphosphatemia is an important determinant of morbidity and mortality in patients with chronic kidney disease (CKD). Patients with CKD are advised to consume a low phosphate diet and are often prescribed phosphate-lowering drug therapy. However, commercially processed food and drinks often contain phosphate compounds, but the phosphate level is not usually provided in the ingredient list, which makes it difficult for CKD patients to choose a correct diet. We conducted a survey of the awareness of food/beverages containing artificially added phosphate among CKD patients undergoing hemodialysis. The subjects were 153 patients (77 males and 76 females; average age 56±11 years) who were randomly selected from the Dialysis Center of Hirosaki City, Japan. The subjects were provided with a list of questions. The survey results showed that 93% of the subjects were aware of the presence of high sugar content in soda, whereas only 25% were aware of the presence of phosphate (phosphoric acid) in such drinks. Despite 78% of the subjects being aware of the detrimental effects of consumption of a high phosphate diet, 43% drank at least 1 to 5 cans of soda per week and about 17% consumed “fast food” once each week. We also assessed the immediate effects of high-phosphate containing carbonated soda consumption by determining urinary calcium, phosphate, protein and sugar contents in overnight fasted healthy volunteers (n = 55; average age 20.7±0.3 years old, 20 males and 35 females). Significantly higher urinary calcium (adjusted using urinary creatinine) excretion was found 2 h after consuming 350 ml of carbonated soda compared to the fasting baseline level (0.15±0.01 vs. 0.09±0.01, p = 0.001). Our survey results suggest that CKD patients undergoing hemodialysis are not adequately aware of the hidden source of phosphate in their diet, and emphasize the need for educational initiatives to raise awareness of this issue among CKD patients.

Phytoestrogenic activity of blackcurrant (Ribes nigrum) anthocyanins is mediated through estrogen receptor alpha

SCOPE Blackcurrants (Ribes nigrum L., Grossulariaceae) contain high amounts of anthocyanin polyphenols, which have antioxidant and anti-carcinogenic health benefits. This study analyzed the potential phytoestrogenic effects of blackcurrant extract (BCE) in breast cancer (MCF-7) and human endometrial cancer (Ishikawa) cell lines that over-express estrogen receptor alpha (ERα), as well as in immature female rats. METHODS AND RESULTS Microarray analysis and Ingenuity® Pathway Analysis showed that BCE activated the ERα pathway, whereas quantitative-PCR confirmed that BCE and four types of anthocyanins up-regulated genes downstream of ERα. BCE (0.1-1.0 μg/mL) and anthocyanins (0.1-10 μM) induced MCF-7 cell proliferation; however, this effect was blocked by ER antagonist fulvestrant. Flow cytometry showed that anthocyanins reduced and increased the number of MCF-7 cells in the G0/G1 and G2/M phases, respectively. Anthocyanins stimulated ERα transcriptional activity in human ERα reporter assays and induced alkaline phosphatase activity in Ishikawa cells. Competition assays and in silico analysis indicated that anthocyanins bind to ERα. Finally, BCE focally induced stratification of columnar epithelial cells in the rat uterus and increased cytoplasmic mucin levels in these cells. CONCLUSION These results suggest that blackcurrant anthocyanins act as phytoestrogens in vitro and in vivo.

Nutritional regulation of coupling factor 6, a novel vasoactive and proatherogenic peptide

High sodium, high glucose, and obesity are important risk factors for age-related diseases such as cardiovascular disease (CVDs), stroke, and cancer. Coupling factor 6 (CF6) is released from vascular endothelial cells and functions as a circulating peptide that inhibits prostacyclin and nitric oxide generation by intracellular acidosis. High glucose elevates CF6 by activation of protein kinase C and p38 mitogen-activated protein kinase, whereas CF6 causes type 2 diabetes mellitus, resulting in a high glucose vicious cycle. Low glucose increases inhibitory factor peptide 1, an endogenous inhibitor of CF6. High salt intake increases CF6 through nuclear factor κB signaling, whereas CF6 induces salt-sensitive hypertension and salt-induced congestive heart failure. Oral administration of vitamin C cancels salt-induced increase in CF6, and estrogen replacement leads to the delayed onset of CF6-induced salt-sensitive hypertension and the rescue from cardiac systolic dysfunction. Because CF6 contributes to the onset of CVDs, nutritional regulation of CF6 will shed light on the understanding of preventive strategy and mechanisms for CVDs and a target for therapy.

Blackcurrant Anthocyanins Increase the Levels of Collagen, Elastin, and Hyaluronic Acid in Human Skin Fibroblasts and Ovariectomized Rats

Blackcurrants (Ribes nigrum L.) contain high levels of anthocyanin polyphenols, which have beneficial effects on health, owing to their antioxidant and anticarcinogenic properties. Phytoestrogens are plant-derived substances with estrogenic activity, which could have beneficial effects on the skin. Estradiol secretion decreases during menopause, reducing extracellular matrix (ECM) component production by skin fibroblasts. Using a normal human female skin fibroblast cell line (TIG113) and ovariectomized rats, the present study investigated whether an anthocyanin-rich blackcurrant extract (BCE) and four blackcurrant anthocyanins have novel phytoestrogenic activities that could benefit the skin in menopausal women. In TIG113 cells, a microarray and the Ingenuity® Pathway Analysis showed that 1.0 μg/mL of BCE upregulated the expression of many estrogen signaling-related genes. A quantitative RT-PCR analysis confirmed that BCE (1.0 or 10.0 μg/mL) and four types of anthocyanins (10 μM) altered the mRNA expression of ECM proteins and enzymes involved in ECM turnover. Immunofluorescence staining indicated that the anthocyanins stimulated the expression of ECM proteins, such as collagen (types I and III) and elastin. Dietary administration of 3% BCE to ovariectomized rats for 3 months increased skin levels of collagen, elastin, and hyaluronic acid. This is the first study to show that blackcurrant phytoestrogens have beneficial effects on skin experimental models.

Spontaneous Micro-Aggregation of Platelets Predicts Clinical Outcome in Acute Ischemic Stroke

BACKGROUNDS Spontaneous micro-aggregation of platelets (SMAP) is frequently observed in stroke patients and is a trigger for the additional development of larger thrombi. We tested the hypothesis that SMAP may predict clinical outcome in acute ischemic stroke patients. METHODS AND RESULTS Consecutive acute ischemic stroke patients (n = 358) who were transferred to our hospital within 24 hours after its onset were enrolled. Peripheral venous blood was sampled to measure various parameters when they arrived. SMAP was correlated with plasma brain natriuretic peptide and diastolic blood pressure positively, and with serum albumin and body weight negatively. Multivariable Cox regression analysis showed that only serum albumin was an independent predictor of the SMAP (P = .0023). The proportion of patients who were functionally independent (score 0-2 on the modified Rankin Scales) at discharge was lower in the third tertile of SMAP (higher level) as compared with the first and the second tertiles in ischemic stroke (odds ratio [OR], 5.76; 95 % confidence interval [CI], 3.31-10.05; P < .0001) and atherothrombotic stroke (P = .02 by chi-square test). The lower proportion of patients achieving independence was found in the first tertile of serum albumin (lower level) as compared with the second and third tertiles in ischemic (OR, 4.60; 95% CI, 2.66-7.95; P < .0001), atherothrombotic, and cardioembolic stroke (P = .004 and P < .0001 by chi-square test). On logistic regression analysis, SMAP and serum albumin remained independent predictors of poor outcome in ischemic stroke. CONCLUSIONS SMAP within 24 hours after stroke onset is a novel independent predictor of clinical outcome in acute ischemic stroke patients.

Intracellular protons accelerate aging and switch on aging hallmarks in mice: OSANAI et al.

Diet‐induced metabolic acidosis is associated with the impairment of bone metabolism and an increased risk of a number of chronic noncommunicable diseases, such as type 2 diabetes mellitus and hypertension. The serum bicarbonate level is an independent predictor of chronic kidney disease progression. We investigated whether proton accelerates aging by analyzing both coupling factor 6‐overexpressing transgenic (TG) and high salt‐fed mice which display sustained intracellular acidosis, due to enhanced proton import through ecto‐F1Fo complex and/or reduced proton export through Na+‐K+ ATPase inhibition. Both types of mice displayed shortened lifespan and early senescence‐associated phenotypes such as signs of hair greying and alopecia, weight loss, and/or reduced organ mass. In chronic intracellular acidosis mice, autophagy was impaired by regression of Atg7, an increase in nuclear acetylated LC3 II, and acetylation of Atg7. The increase in histone 3 trimethylation at lysine 4 (H3K4me3) and H4K20me3 and the decrease in H3K9me3 and H3K27me3 were observed in the heart and kidney obtained from both TG and high salt‐fed mice. The decrease in lamin A/C, emerin, and heterochromatin protein 1α without changes in barrier‐to‐autointegration factor and high‐mobility group box 1 was confirmed in TG and high salt‐fed mice. Suppression of nuclear histone deacetylase 3‐emerin system is attributable to epigenetic regression of Atg7 and H4K5 acetylation. These findings will shed light on novel aging and impaired autophagy mechanism, and provide implications in a target for antiaging therapy.

Mitochondrial inhibitory factor protein 1 attenuates coupling factor 6-induced aging signal

Coupling factor 6 (CF6) forces a counter‐clockwise rotation of plasma membrane F1Fo complex, resulting in proton import and accelerated aging. Inhibitory factor peptide 1 (IF1) suppresses a unidirectional counter‐clockwise rotation of F1Fo complex without affecting ATP synthesis. We tested the hypothesis that IF1 may attenuate CF6‐induced aging signaling in CF6‐overexpressing transgenic (TG) cells. In IF1‐GFP overexpressing wild type (WT) cells, the diffuse peripheral staining of tubular mitochondria was observed with a dense widely distributed network around the nucleus. In TG cells, however, the only peri‐nuclear network of fragmented mitochondria was observed at 24 h, but it was developed to a widely distributed mitochondrial network of tubular mitochondria at 72 h. TG cells displayed aging hallmarks of telomere attrition, epigenetic alterations, defective proteostasis, and genomic instability with a decrease in emerin and lamin and loss of heterochromatin. IF1 induction rescued TG cells from telomere attrition, expression of genomic instability with the increase in emerin and lamin, and that of epigenetic alterations with recovery of heterochromatin. In defective proteostasis, IF1 induction restored a potent peri‐nuclear staining of autolysosomes compared with the baseline weak staining. The decrease in Atg7 was restored, whereas the increase in P62 was abolished. We conclude that genetic disruption of proton signals by IF1 induction suppressed CF6‐induced expression of aging hallmarks such as telomere attrition, epigenetic alterations, defective proteostasis, and genomic instability. Given the widespread biological actions of CF6, the physiological and pathological actions of IF1 may be complex.

Lack of Awareness among Renal Transplant Recipients Regarding Consumption of Phosphate- containing Processed Food and Drinks

In the chronic kidney disease (CKD), adequate phosphate control is critical to reduce mortality rate and cardiovascular risks, besides, it may improve renal prognosis. We surveyed the awareness of the high phosphate content in the commercially processed food and drinks among renal transplant recipients, since they usually have reduced kidney function. Thirty seven subjects were provided with a questionnaire to evaluate their awareness of food and drinks containing phosphate. Most of the subjects (91.9%) were aware of the presence of sugar in soda drinks, but only 13.5% were aware of the presence of phosphate. Only 29.7% understood that phosphate is present in processed food, such as hamburgers and pizza, and 64.9% were unaware of the harmful effects of unrestricted consumption of phosphate-containing food and drinks. In this survey, 24.3%