Publications by authors named "Ken Shirato"

There is an urgent need to develop phage therapies for multidrug-resistant bacterial infections. However, although bacteria have been shown to be susceptible to phage therapy, phage therapy is not sufficient in some cases. PhiMR003 is a methicillin-resistant Staphylococcus aureus phage previously isolated from sewage influent, and it has demonstrated high lytic activity and a broad host range to MRSA clinical isolates in vitro.

View Article and Find Full Text PDF

The circadian rhythm is a biological system that creates daily variations of physiology and behavior with a 24-h cycle, which is precisely controlled by the molecular circadian clock. The circadian clock dominates temporal activity of physiological homeostasis at the molecular level, including endocrine secretion, metabolic, immune response, coupled with extrinsic environmental cues (, light/dark cycles) and behavioral cues (, sleep/wake cycles and feeding/fasting cycles). The other side of the clock is that the misaligned circadian rhythm contributes to the onset of a variety of diseases, such as cancer, metabolic diseases, and cardiovascular diseases, the acceleration of aging, and the development of systemic inflammation.

View Article and Find Full Text PDF

Excessive host inflammation following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with severity and mortality in coronavirus disease 2019 (COVID-19). We recently reported that the SARS-CoV-2 spike protein S1 subunit (S1) induces pro-inflammatory responses by activating toll-like receptor 4 (TLR4) signaling in macrophages. A standardized extract of stem (EAS) is a unique functional food that elicits anti-photoaging effects by suppressing pro-inflammatory signaling in hydrogen peroxide and ultraviolet B-exposed skin fibroblasts.

View Article and Find Full Text PDF

Coronavirus disease 2019 (COVID-19), an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has now spread globally. Some patients develop severe complications including multiple organ failure. It has been suggested that excessive inflammation associated with the disease plays major role in the severity and mortality of COVID-19.

View Article and Find Full Text PDF

Exercise training is well known to enhance adipocyte lipolysis in response to hormone challenge. However, the existence of a relationship between the timing of exercise training and its effect on adipocyte lipolysis is unknown. To clarify this issue, Wistar rats were run on a treadmill for 9 weeks in either the early part (E-EX) or late part of the active phase (L-EX).

View Article and Find Full Text PDF
Article Synopsis
  • Heat shock protein 70 (HSP70) helps protect against skin aging caused by UV exposure, and Asparagus officinalis stem extract (EAS) may promote HSP70 expression in skin cells.
  • In experiments, normal human dermal fibroblasts (NHDFs) treated with EAS before UV-B irradiation showed preserved HSP70 levels, while those exposed to UV-B alone did not.
  • The findings suggest that EAS could serve as a functional food with potential anti-photoaging benefits by maintaining HSP70 expression in skin cells exposed to UV light.
View Article and Find Full Text PDF

We recently reported that ETAS 50, a standardized extract from the stem, exerted anti-inflammatory effects on ultraviolet-B- (UV-B-) irradiated normal human dermal fibroblasts (NHDFs) by inhibiting nuclear factor-B p65 nuclear import and the resulting interleukin-1 (IL-1) expression. To further elucidate the antiphotoaging potency of ETAS 50, we examined the anti-inflammatory effects on UV-B-irradiated NHDFs by focusing on the stress-activated mitogen-activated protein kinase (MAPK) and Akt signaling pathways. NHDFs were treated with 1 mg/mL of ETAS 50 or dextrin (vehicle control) after UV-B irradiation (20 mJ/cm) for different time periods.

View Article and Find Full Text PDF

Ultraviolet (UV) irradiation induces proinflammatory responses in skin cells, including dermal fibroblasts, accelerating premature skin aging (photoaging). ETAS 50, a standardized extract from the stem, is a novel and unique functional food that suppresses proinflammatory responses of hydrogen peroxide-stimulated skin fibroblasts and interleukin- (IL-) 1-stimulated hepatocytes. To elucidate its antiphotoaging potencies, we examined whether ETAS 50 treatment after UV-B irradiation attenuates proinflammatory responses of normal human dermal fibroblasts (NHDFs).

View Article and Find Full Text PDF

Enzyme-treated asparagus extract (ETAS) is prepared from the lower, residual parts of asparagus, and some functionalities, such as anti-oxidative and neuroprotective activities, have been suggested. The purpose of the present study was to investigate the effects of ETAS on photoaging in the epidermal layer of the skin using cultured keratinocytes. Normal human epidermal keratinocytes were irradiated or left unirradiated with UV-B (10 mJ/cm) and incubated with ETAS (0.

View Article and Find Full Text PDF
Article Synopsis
  • - Obesity leads to inflammation in white adipose tissue (WAT), causing an imbalance in inflammation-related adipokines like tumor necrosis factor and monocyte chemoattractant protein-1, which promotes insulin resistance.
  • - WAT in obese individuals produces reactive oxygen species (ROS), and higher ROS levels are linked to the abnormal expression of these adipokines, contributing to health issues.
  • - Exercise training (TR) helps reduce WAT mass and improves the regulation of inflammation-related adipokines, while also potentially lowering oxidative stress in WAT, making it a key strategy for preventing lifestyle-related diseases.
View Article and Find Full Text PDF

Moderate-intensity regular exercise improves proinflammatory responses of lipopolysaccharide- (LPS-) stimulated macrophages. However, intracellular events that mediate the beneficial effects of exercise were unclear. This study aimed to clarify the mechanism by which regular voluntary exercise (VE) improves proinflammatory cytokine production by macrophages challenged with LPS.

View Article and Find Full Text PDF
Article Synopsis
  • About 8-10% of newborns with asymptomatic congenital cytomegalovirus (cCMV) infection develop sensorineural hearing loss (SNHL), prompting a study to investigate the links between CMV load, SNHL, and central nervous system (CNS) damage.
  • The study analyzed 23,368 newborns in Japan, screening for cCMV infection via urine tests and assessing hearing through automated auditory brainstem response (AABR) testing.
  • Findings indicated a low incidence of cCMV (0.257%), with a notable 22.7% of infants with SNHL also infected with cCMV; higher urinary CMV loads were linked to both SNHL and CNS damage as
View Article and Find Full Text PDF

We recently reported that enzyme-treated asparagus extract (ETAS) attenuates hydrogen peroxide (H(2)0(2))-stimulated matrix metalloproteinase-9 expression in skin fibroblast L929 cells. To further elucidate the anti-aging effects of ETAS on skin, we examined whether ETAS has preventive effects on H202-induced pro-inflammatory responses of skin fibroblasts. H(2)0(2) induced Ser536 phosphorylation and nuclear accumulation of nuclear factor-κB (NF-κB) p65, and increased the mRNA levels .

View Article and Find Full Text PDF

Enzyme-treated asparagus extract (ETAS) exerts a wide variety of beneficial biological actions including facilitating anti-cortisol stress and neurological anti-aging responses. However, the anti-skin aging effects of ETAS remain to be elucidated. Reactive oxygen species (ROS) play pivotal roles in skin aging.

View Article and Find Full Text PDF

Circadian rhythms have long been known to regulate numerous physiological processes that vary across the diurnal cycle. The circadian clock system also controls various parameters of the immune system and its biological defense functions, allowing an organism to anticipate daily changes in activity and feeding and the associated risk of infection. Inflammation is an immune response triggered in living organisms in response to external stimuli.

View Article and Find Full Text PDF

It is widely accepted that lipolysis in adipocytes are regulated through the enzymatic activation of both hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) via their phosphorylation events. Accumulated evidence shows that habitual exercise training (HE) enhances the lipolytic response in primary white adipocytes with changes in the subcellular localization of lipolytic molecules. However, no study has focused on the effect that HE exerts on the phosphorylation of both HSL and ATGL in primary white adipocytes.

View Article and Find Full Text PDF

Physical exercise accelerates the mobilization of free fatty acids from white adipocytes to provide fuel for energy. This happens in several tissues and helps to regulate a whole-body state of metabolism. Under these conditions, the hydrolysis of triacylglycerol (TG) that is found in white adipocytes is known to be augmented via the activation of these lipolytic events, which is referred to as the "lipolytic cascade.

View Article and Find Full Text PDF

It is now evident that many nuclear hormone receptors can modulate target gene expression. REV-ERBα, one of the nuclear hormone receptors with the capacity to alter clock function, is critically involved in lipid metabolism, adipogenesis, and the inflammatory response. Recent studies suggest that REV-ERBα plays a key role in the mediation between clockwork and inflammation.

View Article and Find Full Text PDF

The intensities of macrophage inflammatory responses to bacterial components gradually decrease with age. Given that a reduced rate of protein synthesis is a common age-related biochemical change, which is partially mediated by increased phosphorylation of eukaryotic initiation factor-2 α (eIF-2 α ), we investigated the mechanism responsible for the deterioration of macrophage inflammatory responses, focusing specifically on the age-related biochemical changes in middle-aged mice. Peritoneal macrophages isolated from 2-month-old (young) and 12-month-old (middle-aged) male BALB/c mice were stimulated with lipopolysaccharide (LPS).

View Article and Find Full Text PDF

The acute effects of oral administration of diallyl disulfide (DADS), the major organosulfur compound of garlic, on plasma glucose and free fatty acid (FFA) concentrations were examined in rats. Male, 10-week-old Sprague-Dawley rats were divided into DADS-free and DADS-administered (dose = 10, 20, and 40 mg/kg body weight [BW]) groups. Plasma samples were prepared from whole blood drawn from the tail vein 0, 1, 2, 4, and 6 hr after administration.

View Article and Find Full Text PDF
Article Synopsis
  • - Nucleotide sugars, especially UDP-GlcNAc, are crucial for glycan biosynthesis and are influenced by metabolic states in diseases like cancer and diabetes.
  • - The authors developed a tracing method using (13)C6-glucose and (13)C2-glucosamine to analyze UDP-GlcNAc's synthesis and utilization, finding variations in labeling efficiencies between different cell types, particularly between pancreatic insulinoma and hepatoma cells.
  • - Insulinoma cells showed lower labeling efficiencies for sialic acids and complex N-glycans, indicating a metabolic flow that impacts sialylation, while no significant difference in secreted hyaluronic acids was observed among cell lines.
View Article and Find Full Text PDF

Bacterial or viral infection of the airway plays a critical role in the pathogenesis and exacerbation of chronic obstructive pulmonary disease (COPD) which is expected to be the 3rd leading cause of death by 2020. The induction of inflammatory responses in immune cells as well as airway epithelial cells is observed in the disease process. There is thus a pressing need for the development of new therapeutics.

View Article and Find Full Text PDF

The aim of this study was to clarify the intracellular β2-adrenergic receptor signaling specificity in mouse slow-twitch soleus and fast-twitch tibialis anterior (TA) muscles, resulting from single-dose β2-agonist clenbuterol treatment and acute exercise. At 1, 4, and 24 h after single-dose treatment with clenbuterol or after acute running exercise, the soleus and TA muscles were isolated and subjected to analysis. The phosphorylation of p38 mitogen-activated protein kinase (MAPK) increased after single-dose clenbuterol treatment and acute exercise in the soleus muscle but not in the TA muscle.

View Article and Find Full Text PDF

Splenic marginal zone macrophages expressing macrophage receptor with collagenous structure (MARCO) contribute to the clearance of blood-borne pathogens. We determined a splenic adherent cell fraction abundantly containing cells expressing a higher level of MARCO by flow cytometry, and examined the effects of daily administration of an anabolic dose of β2-agonist clenbuterol on the phagocytic capacity of the cells in mice. After 6 weeks of clenbuterol (1.

View Article and Find Full Text PDF