Decreased Memory and Learning Ability Mediated by Bmal1/M1 Macrophages/Angptl2/Inflammatory Cytokine Pathway in Mice Exposed to Long-Term Blue Light Irradiation.

Humans are persistently exposed to massive amounts of blue light via sunlight, computers, smartphones, and similar devices. Although the positive and negative effects of blue light on living organisms have been reported, its impact on learning and memory remains unknown. Herein, we examined the effects of widespread blue light exposure on the learning and memory abilities of blue light-exposed mice. Ten-week-old male ICR mice were divided into five groups (five mice/group) and irradiated with blue light from a light-emitting diode daily for 6 months. After 6 months of blue light irradiation, mice exhibited a decline in memory and learning abilities, assessed using the Morris water maze and step-through passive avoidance paradigms. Blue light-irradiated mice exhibited a decreased expression of the clock gene brain and muscle arnt-like 1 (Bmal1). The number of microglia and levels of M1 macrophage CC-chemokine receptor 7 and inducible nitric oxide synthase were increased, accompanied by a decrease in M2 macrophage arginase-1 levels. Levels of angiopoietin-like protein 2 and inflammatory cytokines interleukin-6, tumor necrosis factor-α, and interleukin-1ß were elevated. Our findings suggest that long-term blue light exposure could reduce Bmal1 expression, activate the M1 macrophage/Angptl2/inflammatory cytokine pathway, induce neurodegeneration, and lead to a decline in memory.

Interactions between Age-Related Type 2 Diabetes and the Small Intestine.

The number of patients with type 2 diabetes is increasing worldwide. The mechanisms leading to type 2 diabetes and its complications is being researched; however, the pathological mechanisms of diabetes in the small intestine remain unclear. Therefore, we examined these pathological mechanisms in the small intestine using a mouse model of type 2 diabetes (KK-Ay/TaJcl) aged 10 and 50 weeks. The results showed that diabetes worsened with age in the mice with type 2 diabetes. In these mice, advanced glycation end products (AGEs) in the small intestine and mast cell expression increased, whereas diamine oxidase (DAO) decreased; increased tumor necrosis factor (TNF)-α and histamine levels in the plasma and small intestine were also detected. Additionally, the expression of zonula occludens (ZO)-1 and Claudin1 and cell adhesion molecules in the small intestine reduced. These results exacerbated with age. These findings indicate that type 2 diabetes causes AGE/mast cell/histamine and TNF-α signal transmission in the small intestine and decreases small intestinal wall cell adhesion molecules cause TNF-α and histamine to flow into the body, worsening the diabetic condition. In addition, this sequence of events is suggested to be strengthened in aged mice with type 2 diabetes, thus exacerbating the disease. These findings of this study may facilitate the elucidation of the pathological mechanisms of type 2 diabetes and its associated complications.

Inhibiting Neutrophil Extracellular Traps Protects against Ultraviolet B-Induced Skin Damage: Effects of Hochu-ekki-to and DNase I.

UV-B radiation induces sunburn, and neutrophils are pivotal in this inflammation. In this study, we examined the potential involvement of neutrophil extracellular traps (NETs) in ultraviolet B (UVB)-induced skin inflammation, correlating the skin inflammation-mitigating effects of Hochu-ekki-to on UV-B irradiation and NETs. To elucidate NET distribution in the dorsal skin, male ICR mice, exposed to UVB irradiation, were immunohistologically analyzed to detect citrullinated histone H3 (citH3) and peptidylarginine deiminase 4 (PAD4). Reactive oxygen species (ROS) production in the bloodstream was analyzed. To establish the involvement of NET-released DNA in this inflammatory response, mice were UV-B irradiated following the intraperitoneal administration of DNase I. In vitro experiments were performed to scrutinize the impact of Hochu-ekki-to on A23187-induced NETs in neutrophil-like HL-60 cells. UV-B irradiation induced dorsal skin inflammation, coinciding with a significant increase in citH3 and PAD4 expression. Administration of DNase I attenuated UV-B-induced skin inflammation, whereas Hochu-ekki-to administration considerably suppressed the inflammation, correlating with diminished levels of citH3 and PAD4 in the dorsal skin. UV-B irradiation conspicuously augmented ROS and hydrogen peroxide (H2O2) production in the blood. Hochu-ekki-to significantly inhibited ROS and H2O2 generation. In vitro experiments demonstrated that Hochu-ekki-to notably inhibited A23187-induced NETs in differentiated neutrophil-like cells. Hence, NETs have been implicated in UV-B-induced skin inflammation, and their inhibition reduces cutaneous inflammation. Additionally, Hochu-ekki-to mitigated skin inflammation by impeding neutrophil infiltration and NETs in the dorsal skin of mice.

The Mechanism of 5-Fluorouracil-Induced Hyperpigmentation in HRM-2 Hairless Mice: Focus on the Increase of Blood Vessels.

5-Fluorouracil (5-FU), an effective chemotherapeutic agent for many solid tumors, has long been reported to cause pigmentation in patients treated intravenously, which occurs with increasing frequency of administration and decreases the QOL of the patients. Although melanin accumulation is thought to be the cause, the mechanism of pigmentation induced by 5-FU administration remains unclear, and there is no effective treatment for this problem. In this study, we investigated the mechanism of pigmentation induced by continuous 5-FU administration in 9-week-old male HRM-2 hairless mice for 8 weeks by focusing on the blood vessels for basic verification. In the auricular skin of 5-FU-administered mice, hyperpigmentation caused by melanin accumulation was observed macroscopically and by Fontana-Masson Staining. In addition, the expression of tyrosinase, melanin synthase, and blood vessel markers in the auricular skin was increased by 5-FU-administration in mice auricular skin. Other anticancer agents, cytarabine (Ara-C) and irinotecan (CPT-11), were also administered, and the differences between them and 5-FU were investigated; these changes were not observed in the auricles of these mice. These results suggest that tyrosinase is associated with 5-FU-induced melanin production and that an increase in blood vessels may be involved. Furthermore, pigmentation with melanin accumulation in the basal epidermal layer is a characteristic finding of 5-FU compared with Ara-C and CPT-11. In conclusion, this study indicates that 5-FU causes hyperpigmentation by melanin accumulation in a characteristic manner, including an increase in blood vessels.

Oral Administration of Rhamnan Sulfate from Monostroma nitidum Suppresses Atherosclerosis in ApoE-Deficient Mice Fed a High-Fat Diet.

Oral administration of rhamnan sulfate (RS), derived from the seaweed Monostroma nitidum, markedly suppresses inflammatory damage in the vascular endothelium and organs of lipopolysaccharide-treated mice. This study aimed to analyze whether orally administered RS inhibits the development of atherosclerosis, a chronic inflammation of the arteries. ApoE-deficient female mice were fed a normal or high-fat diet (HFD) with or without RS for 12 weeks. Immunohistochemical and mRNA analyses of atherosclerosis-related genes were performed. The effect of RS on the migration of RAW264.7 cells was also examined in vitro. RS administration suppressed the increase in blood total cholesterol and triglyceride levels. In the aorta of HFD-fed mice, RS reduced vascular smooth muscle cell proliferation, macrophage accumulation, and elevation of VCAM-1 and inhibited the reduction of Robo4. Increased mRNA levels of Vcam1, Mmp9, and Srebp1 in atherosclerotic areas of HFD-fed mice were also suppressed with RS. Moreover, RS directly inhibited the migration of RAW264.7 cells in vitro. Thus, in HFD-fed ApoE-deficient mice, oral administration of RS ameliorated abnormal lipid metabolism and reduced vascular endothelial inflammation and hyperpermeability, macrophage infiltration and accumulation, and smooth muscle cell proliferation in the arteries leading to atherosclerosis. These results suggest that RS is an effective functional food for the prevention of atherosclerosis.

The Effect of Bacillus coagulans Induced Interactions among Intestinal Bacteria, Metabolites, and Inflammatory Molecules in Improving Natural Skin Aging.

BACKGROUND: Lactic acid bacteria consumption serves several health benefits to humans. However, their effect on natural skin aging is still unclear. METHODS: This study examined the effects of skin naturalization (particularly skin drying) by administering a spore-bearing lactic acid bacteria (Bacillus coagulans) in mice for 2 years. RESULTS: B. coagulans administration improved the natural skin of mice and significantly increased proportions of the genera Bacteroides and Muribaculum, among other intestinal bacteria. As metabolites, increases in nicotinic acid, putrescin, and pantothenic acid levels and a decrease in choline levels were observed. Increased hyaluronic acid, interleukin-10, and M2 macrophage levels indicate aging-related molecules in the skin. Intestinal permeability was also suppressed. Thus, these changes together improved natural skin aging. CONCLUSIONS: This study revealed that B. coagulans administration improved the natural skin aging in mice. This enhancement might be induced by the interaction of alterations in intestinal flora, metabolites, or inflammatory substances.

Induction of Skin Cancer by Long-Term Blue Light Irradiation.

Presently, people are not only exposed to sunlight but also to a large amount of blue light from personal computers and smartphones. This blue light has various effects on the living body. However, its effect on the induction of skin cancer is unknown. In this study, we investigated the induction of skin cancer by long-term blue light irradiation. Hairless mice were irradiated with blue light (LED; peak emission 479 nm) every day for one year, and a control was irradiated with white light (LED), green light (LED; peak emission 538 nm), and red light (LED; peak emission 629 nm) for one year, respectively. Skin cancer was induced only in the mice exposed to blue light. Long-term blue light irradiation also increased the migration of neutrophils and macrophages involved in carcinogenesis in the skin. In neutrophils, an increased expression of citH3 and PAD4 was observed, suggesting the possibility of NETosis. Conversely, in macrophages, inflammatory macrophages (type 1 macrophages) increased and anti-inflammatory macrophages (type 2 macrophages) decreased due to continuous blue light irradiation. These findings suggest that long-term continuous irradiation with blue light induces neutrophil NETosis and an increase in type 1 macrophages, resulting in skin cancer.

Dementia Is Induced via the AGEs/Iba1/iNOS Pathway in Aged KK-Ay/Tajcl Mice.

The onset and exacerbation of dementia have been observed in elderly patients with type 2 diabetes. However, the underlying mechanism remains unclear. In this study, we investigated the effects of aging on the cognitive function in a mouse model of type 2 diabetes. Pathogen-free KK-Ay/TaJcl mice were used in this study. The cognitive abilities and memory declined in the mice and worsened in the 50-week-olds. The levels of advanced glycation end products (AGEs), receptor for AGE (RAGE), and Iba1 in the hippocampus were increased in the mice compared to those in the control mice. Hippocampal levels of CC-chemokine receptor 7 and inducible nitric oxide synthase, which are from M1-type macrophages that shift from microglia, were higher in KK-Ay/TaJcl mice than in control mice. Tumor necrosis factor (TNF)-α and nitric oxide (NO) levels secreted by M1-type macrophages were similarly elevated in the mice and were even higher at the age of 50 weeks. NO levels were markedly elevated in the 50-week-old mice. In contrast, differentiation of CD163 and arginase-1 did not change in both mouse types. Memory and learning declined with age in diabetic mice, and the AGEs/RAGE/M1-type macrophage/NO and TNF-α pathways played an important role in exacerbating memory and learning in those mice.

Changes in the AGE/Macrophage/TNF-α Pathway Affect Skin Dryness during KK-Ay/Tajcl Mice Aging.

Skin dryness associated with type 2 diabetes worsens with age; however, the underlying mechanisms remain unclear. Herein, we investigated the effects of aging on skin dryness using a type 2 diabetes mice model. Specific pathogen-free KK-Ay/TaJcl mice of different ages (10, 27, 40, and 50 weeks) were used in this study. The results confirmed that skin dryness worsens with age. Furthermore, increased levels of advanced glycation end products (AGE), prostaglandin E2 (PGE2), and tumor necrosis factor (TNF)-α, along with an increased expression of the major AGE receptor (RAGE), an increased macrophage number, and decreased collagen expression were observed in the skin of aged KK-Ay/TaJcl mice. In conclusion, dry skin conditions worsen with age in diabetic mice, and the AGE/RAGE/PGE2 and TNF-α pathways play an important role in exacerbating skin dryness during aging in these mice.

ACTH/cAMP-Mediated Skin Pigmentation Caused by 5-Fluorouracil Administration.

Anticancer drugs exhibit many side effects, including skin pigmentation, which often lowers patient QOL. However, the mechanism of pigmentation caused by anticancer drugs remains unknown. The purpose of this study was to elucidate the mechanism of anticancer drug-induced skin pigmentation using 5-fluorouracil (5-FU), a widely used anticancer drug. Specific pathogen-free, 9-week-old Hos:HRM-2 male mice were intraperitoneally administered 5-FU daily for 8 weeks. Skin pigmentation was observed at the end of the study. Mice treated with 5-FU were also administered inhibitors of cAMP, α-melanocyte-stimulating hormone (α-MSH), and adrenocorticotropic hormone (ACTH) for analysis. Administration of oxidative stress, nuclear factor-kappa B (NF-κB), cAMP, and ACTH inhibitors reduced pigmentation in 5-FU-treated mice. These results indicate that the oxidative stress/NF-κB/ACTH/cAMP/tyrosinase pathway plays an important role in pigmentation in 5-FU-treated mice.

Edoxaban, a Factor Xa-Specific Direct Oral Anticoagulant, Significantly Suppresses Tumor Growth in Colorectal Cancer Colon26-Inoculated BALB/c Mice.

Introduction Certain low-molecular-weight heparins have been reported to reduce tumor growth and metastasis in tumor cell-inoculated mouse models and cancer patients. Recently, direct oral anticoagulants (DOACs) have been widely used in patients with thromboembolism. This study was aimed at investigating the effect of DOACs, which target thrombin or factor Xa, on tumor growth in a syngeneic mouse model comprising BALB/c mice inoculated with colon cancer Colon26 cells. Materials and Methods DOACs targeting thrombin (dabigatran etexilate [DABE]) or factor Xa (rivaroxaban [RVX] and edoxaban [EDX]) were orally administered daily to male BALB/c mice inoculated with Colon26 cells, followed by analyses of tumor growth and plasma levels of coagulation- and tumor-related factors such as tissue factor (TF), plasminogen activator inhibitor-1 (PAI-1), interleukin-6 (IL-6), and matrix metalloproteinase-2 (MMP-2). Results Colon26 cells expressed significant amounts of functionally active TF. Tumor growth in Colon26-inoculated mice was significantly suppressed in DABE- or RVX-treated mice ( p <0.05) and was suppressed more significantly in EDX-treated mice ( p <0.01). Therefore, the antitumor mechanism of action of EDX was investigated next. Plasma levels of TF, PAI-1, IL-6, and MMP-2 were elevated in Colon26-inoculated mice but were significantly reduced in EDX-treated mice ( p <0.01). The expression of protease-activated receptor (PAR)1, PAR2, signal transducer and activator of transcription-3 (STAT3), cyclin D1, and Ki67 was increased in tumor tissue of Colon26-inoculated mice but (except for PAR1) was significantly decreased in tumor tissues of EDX-treated mice ( p <0.01). In addition, apoptotic cells and p53 protein levels were significantly increased in tumor tissues of EDX-treated mice. Conclusion The data suggest that among the tested DOACs, EDX significantly suppresses tumor cell proliferation via the factor Xa-PAR2 pathway, which is activated by coagulation and inflammation in Colon26-inoculated mice and induces tumor cell apoptosis.

Skin, Liver, and Kidney Interactions Contribute to Skin Dryness in Aging KK-Ay/Tajcl Mice.

Type 2 diabetes is a lifestyle-related disease that affects people worldwide and is especially prevalent in the elderly. Many elderly people with diabetes also complain of dry skin; however, the relationship between aging and dry skin in type 2 diabetes is unknown. The purpose of this study was to examine the interaction between aging and dry skin using the specific pathogen-free KK-Ay/TaJcl type 2 diabetes mouse model. Skin dryness in this model increases with age and was evaluated at 10, 27, 40, and 50 weeks. We observed increased mast cell expression, increased histamine and matrix metalloproteinase-1 levels, and decreased collagen expression in the skin of aging KK-Ay/TaJcl mice. In addition, the increased expression of angiopoietin 2, interleukin-6, tumor necrosis factor-α, and endostatin in the blood indicated kidney damage in this model. Aging KK-Ay/TaJcl mice also showed fatty liver pathology, which led to increased reactive oxygen species in the blood and liver, as well as the increased expression of M1 macrophages in the liver. These results showed that dry skin is associated with skin, kidney, and liver interactions in an aging type 2 diabetes mouse model.

Relationships of pain-causing substances with dry skin and effects of zaltoprofen on alleviation of symptoms in arthritis model mice.

Purpose: Skin dryness is a symptom of rheumatoid arthritis (RA). However, the mechanisms through which dry skin is induced in RA are unclear. Accordingly, in this study, we characterized substances related to pruritus and pain and then evaluated whether oral administration of zaltoprofen (ZLT) alleviated the symptom of dry skin induced by RA in model mice.Material and Methods: DBA/1JJmsSlc collagen-induced arthritis model mice were treated with ZLT, and transepidermal water loss (TEWL), capacitance, and inflammation-, pruritus-, and pain-related markers were assessed.Results: Our findings demonstrated that arthritis model mice treated with ZLT exhibited suppression of increases in TEWL and decreases in capacitance. Furthermore, ZLT also blocked the increase in mast cell numbers, substance P expression, and cyclo-oxygenase-2 expression in the skin and prevented enhancement of plasma levels of thymic stromal lymphopoietin, tumour necrosis factor-α, interleukin-6, histamine, and bradykinin. No changes in plasma levels of corticosterone or reactive oxygen species or skin levels of glucocorticoid receptor were observed in ZLT-treated arthritis model mice.Conclusions: Overall, these findings suggested that patients with RA may benefit from biopharmacy to alleviate joint symptoms and nonsteroidal anti-inflammatory drugs for pain relief and alleviation of skin symptoms.

Effect of Celecoxib Administration on the Skin of 40-Week-Old Mice.

Various side effects associated with the use of nonsteroidal anti-inflammatory drugs (NSAIDs) in analgesia have been reported. Among the NSAIDs, celecoxib has fewer side effects and is often used in therapeutic applications. However, the effect of celecoxib on aged skin is unknown. In this study, we investigated the effects of celecoxib administration on the skin of aged mice. We analyzed a 40-week-old mouse model and a 10-week-old mouse as the control group. The animals were orally administered celecoxib for four consecutive days and then killed and dissected the day after the last dose. In aged mice treated with celecoxib, the water content of the stratum corneum, which is one of the markers of dry skin, was lower than that in the control and young mice groups. In addition, serum hyaluronic acid, creatinine, and inflammatory cytokines in the collected blood samples of aged mice were elevated compared to those in other mice groups, suggesting the onset of acute renal injury. Therefore, it was considered that acute renal injury occurred from the administration of celecoxib to aged mice, whereas dry skin developed by the promotion of inflammatory cytokine secretion and release into the bloodstream in this group.

Introduction of Fluorine into Antitumor-Active Dinuclear Platinum(II) Complexes Leads to Modulation of In Vivo Antitumor Activity in Mice.

Tetrazolato-bridged dinuclear platinum(II) complexes ([{cis-Pt(NH3)2}2(µ-OH)(µ-5-R-tetrazolato-N2,N3)]2+; tetrazolato-bridged complexes) show remarkable cytotoxic effects in vitro and antitumor activity in vivo. Here, we examined the structure-activity relationship of a series of fluorine-containing derivatives (R = CFH2, CF2H, or CF3), focusing on their lipophilicity, cellular accumulation, cytotoxicity, interactions with a nucleobase and double-stranded deoxyribonucleic acid, and in vivo antitumor efficacy. Fluorination had a little effect on the properties of the derivatives in vitro; however, marked differences in in vitro cytotoxicity and in vivo tumor growth inhibition activity were observed. In BALB/c mice bearing colon-26 tumors, the antitumor efficacies of the derivatives were markedly altered, even by changing the number of fluorine atoms by one. In addition, one derivative, [{cis-Pt(NH3)2}2(µ-OH)(µ-5-difluoromethyltetrazolato-N2,N3)](NO3)2, showed a significantly higher antitumor efficacy compared with oxaliplatin, a current first-line drug and the only platinum-based drug approved for the treatment of colon cancer. Together, the present results indicate that introducing fluorine into tetrazolato-bridged complexes may be useful for modulating in vivo activities.

Skin Dryness Induced in the KK-Ay/TaJcl Type 2 Diabetes Mouse Model Deteriorates Following Dapagliflozin Administration.

Various diabetic drugs have been developed as the number of patients with type 2 diabetes has increased. Sodium-glucose cotransporter (SGLT)-2 inhibitors have been developed as novel therapeutic agents. However, SGLT-2 inhibitors cause skin dryness. The mechanism through which SGLT-2 inhibitors cause skin dryness is unknown. The purpose of this study was to investigate the mechanism through which dapagliflozin, a SGLT-2 inhibitor, induces skin dryness. Specific pathogen-free KK-Ay/TaJcl (type 2 diabetes model) mice were orally administered with SGLT-2 inhibitor (dapagliflozin) daily for 4 weeks at a dose of 1 mg/kg/d. Skin dryness induced in KK-Ay/TaJcl mice became severe after dapagliflozin administration. Dapagliflozin treatment decreased collagen type I and hyaluronic acid levels in mice; additionally, it affected the transforming growth factor (TGF)-ß/hyaluronan synthase pathway, further reducing hyaluronic acid levels. The results indicate that the reduction in hyaluronic acid levels plays an important role in the occurrence of dry skin in diabetes.

Tranexamic acid reduces endometrial cancer effects through the production of angiostatin.

Tranexamic acid (TA) has been reported to exhibit antitumor effects in various mouse models of cancer. However, the mechanism underlying its antitumor effects against endometrial cancer remains to be elucidated. This study was aimed at investigating the efficacy of TA against chronic inflammation-associated endometrial cancer induced by N-methyl-N-nitrosourea (MNU) and estradiol in a mouse model. After cancer induction, the mice were administered TA (12 mg/kg) three times weekly during the experimental period. The endometrial cancer development induced by MNU and estradiol was ameliorated by TA administration. Furthermore, TA treatment suppressed the levels of carbohydrate antigen 125, interleukin-6, and tumor necrosis factor-α in the plasma. The level of plasminogen, known as a TA target, increased in endometrial cancer and was further increased by TA treatment. On the other hand, plasmin levels increased in the model mice but decreased after TA treatment. Furthermore, the macrophage counts and the levels of matrix metalloproteinase (MMP)-12 and angiostatin in tumor cells in the uterus increased compared to the corresponding values in the control group and further increased upon TA treatment. The results of our study indicate that TA ameliorated the endometrial cancer induced by MNU and estradiol by regulating the macrophage/MMP-12/plasminogen/angiostatin signal transmission pathway.

Anti-Inflammatory Activity of Orally Administered Monostroma nitidum Rhamnan Sulfate against Lipopolysaccharide-Induced Damage to Mouse Organs and Vascular Endothelium.

We previously reported that rhamnan sulfate (RS) purified from Monostroma nitidum significantly suppressed lipopolysaccharide (LPS)-induced inflammation in cultured human vascular endothelial cells. Here, we analyzed the effect of orally administered RS on LPS-induced damage to mouse organs and vascular endothelium. RS (1 mg) was orally administered daily to BALB/c mice, 50 µg of LPS was intraperitoneally administered on day 8, and Evans blue was injected into the tail vein 6 h later. After 30 min, LPS-treated mice showed pulmonary Evans blue leakage and elevated plasma levels of liver damage markers, whereas this reaction was suppressed in LPS + RS-treated mice. Immunohistochemical and Western blot analysis of mouse organs 24 h after LPS treatment showed significant neutrophil infiltration into the lung, liver, and jejunum tissues of LPS-treated mice and high expression levels of inflammation-related factors in these tissues. Expression levels of these factors were significantly suppressed in LPS + RS-treated mice. Analysis of lung glycocalyx showed a significant reduction in glycocalyx in LPS-treated mice but not in LPS + RS-treated mice. Levels of syndecan-4, one of the glycocalyx components, decreased in LPS-treated mice and increased in LPS + RS-treated mice. The current results suggest that orally administered RS protects organs and vascular endothelium from LPS-induced inflammation and maintains blood circulation.

Data on synthesis and structure-activity relationships of tetrazolato-bridged dinuclear platinum(II) complexes.

In this data file, the synthetic procedures for the preparation of a series of anticancer tetrazolato-bridged dinuclear platinum(II) complexes ([{cis-Pt(NH3)2}2(µ-OH)(µ-5-R-tetrazolato-N2,N3)]n+ (n = 1 or 2, tetrazolato-bridged complexes)) and of the bridging ligands of 5-substituted 1H-tetrazoles (5-R-1H-tetrazoles) are described. These compounds were characterized by 1H-, 13C-, 19F- and 195Pt-NMR spectroscopy and mass spectrometry.