Yoshinori Katakura

Our goal was to determine whether anserine/carnosine supplementation (ACS) suppresses chemokine levels in elderly people. In a double-blind randomized controlled trial, volunteers were assigned to the ACS or placebo group (1:1). Sixty healthy elderly volunteers (active, <i>n</i> = 30; placebo, <i>n</i> = 30) completed the study. The ACS group was administered 1.0 g of anserine/carnosine (3:1) for 3 months. A microarray analysis and subsequent quantitative real-time polymerase chain reaction (qRT

Enhanced telomerase reverse transcriptase (TERT) levels in dermal keratinocytes can serve as a novel target for hair growth promotion. Previously, we identified fisetin using a system for screening food components that can activate the TERT promoter in HaCaT cells (keratinocytes). In the present study, we aimed to clarify the molecular basis of fisetin-induced hair growth promotion in mice. To this end, the dorsal skin of mice was treated with fisetin, and hair growth was evaluated 12 days after

Pomegranate-derived polyphenols are expected to prevent life-style related diseases. In this study, we evaluated the ability of 8 pomegranate-derived polyphenols, along with other polyphenols, to augment <i>SIRT3</i>, a mammalian <i>SIR2</i> homolog localized in mitochondria. We established a system for screening foods/food ingredients that augment the <i>SIRT3</i> promoter in Caco-2 cells and identified 3 SIRT3-augmenting pomegranate-derived polyphenols (eucalbanin B, pomegraniin A, and eucarpa

Carnosine (β-Ala-l-His), an imidazole dipeptide, is known to have many functions. Recently, we demonstrated in a double-blind randomized controlled trial that carnosine is capable of preserving cognitive function in elderly people. In the current study, we assessed the ability of carnosine to activate the brain, and we tried to clarify the molecular mechanisms behind this activation. Our results demonstrate that carnosine permeates the blood brain barrier and activates glial cells within the bra

Although thinning hair and alopecia are not recognized as severe diseases, hair loss has implications for mental health and quality of life; therefore, a large number of studies have been carried out to develop novel hair growth agents. In the present study, we aimed to examine the potential of telomerase reverse transcriptase (TERT), because <i>TERT</i> overexpression in skin activates resting hair follicle bulge stem cells, which triggers initiation of a new hair follicle growth phase and prom

In our previous studies, we reported that SIRT1 prevents cellular senescence in human fibroblast, and that SIRT1-induced inhibition of cellular senescence is due to enhanced hTERT gene expression. In this study, we investigate the molecular mechanisms behind SIRT1-induced potentiation of hTERT transcription and show that FOXO3a functions downstream of SIRT1 and prevents the induction of cellular senescence by enhancing hTERT gene expression. Furthermore, we found that FOXO3a-induced potentiation

Recently, we showed that imidazole dipeptide such as carnosine contained abundantly in chicken breast meat improves brain function in a double-blind randomized controlled trial. However, the underlying molecular mechanisms remain unknown. Here, we investigated whether carnosine activates intestinal epithelial cells and induces the secretion of factors that activate brain function. We focused on exosomes derived from intestinal epithelial cells as mediators of brain-gut interaction. Results showe

The oral administration of γ-aminobutyric acid (GABA) has been shown to affect brain functions. However, the molecular mechanisms underlying GABA-induced gut-brain interactions have not yet been fully elucidated. As the blood-brain barrier is impermeable to GABA, we hypothesized that the gut-brain interaction might be stimulated by some secretory factors derived from the gut. Then we focused on exosomes as a secretory mediator. In the present study, we investigated whether exosomes derived from

γ-Aminobutyric acid (GABA) is a potent bioactive amino acid, and several studies have shown that oral administration of GABA induces relaxation, improves sleep, and reduces psychological stress and fatigue. In a recent study, we reported that exosomes derived from GABA-treated intestinal cells serve as signal transducers that mediate brain-gut interactions. Therefore, the purpose of this study was to verify the functionality of GABA-derived exosomes and to examine the possibility of improving me

We attempted to evaluate a novel purification method of immunoglobulins (IgGs) by using a mutant type of protein A. Although this mutant protein A binds to IgGs at 5°C, the IgGs are released at 40°C; hence, it was designated as thermo-responsive protein A (TRPA). We aimed to purify IgG1 from the culture supernatant of CHO cells producing AE6F4 human monoclonal IgG1. AE6F4 IgG1 was purified using only a TRPA-filled column and by modifying the temperature, without any exposure to acidic conditions

In the present study, we clarified that transforming growth factor beta (TGF-beta) induces cellular senescence in human normal diploid cells, TIG-1, and identified protein kinase Cs (PKCs) as downstream mediators of TGF-beta-induced cellular senescence. Among PKCs, we showed that PKC-delta induced cellular senescence in TIG-1 cells and was activated in replicatively and prematurely senescent TIG-1 cells. The causative role of PKC-delta in cellular senescence programs was demonstrated using a kin