Effects of D-allose on ATP production and cell viability in neonatal rat cardiomyocytes.

2-Deoxy-d-glucose (2DG) induces anticancer effects through glycolytic inhibition but it may raise the risk of arrhythmia. The rare monosaccharide d-allose also has anticancer properties, but its cardiac effects are unknown. We examined the effects of d-allose on adenosine triphosphate (ATP) production in neonatal rat cardiomyocytes. We showed that 25 mM d-allose selectively reduced glycolytic ATP, but had minimal impact on mitochondrial ATP, while 1 mM 2DG strongly inhibited both. Furthermore, d-allose had less impact on cell viability and was less cytotoxic than 2DG; neither compound caused apoptosis. Thus, d-allose selectively diminished glycolytic ATP production with no apparent effects on cardiomyocytes.

CA9 and PRELID2; hypoxia-responsive potential therapeutic targets for pancreatic ductal adenocarcinoma as per bioinformatics analyses.

A strong hypoxic environment has been observed in pancreatic ductal adenocarcinoma (PDAC) cells, which contributes to drug resistance, tumor progression, and metastasis. Therefore, we performed bioinformatics analyses to investigate potential targets for the treatment of PDAC. To identify potential genes as effective PDAC treatment targets, we selected all genes whose expression level was related to worse overall survival (OS) in The Cancer Genome Atlas (TCGA) database and selected only the genes that matched with the genes upregulated due to hypoxia in pancreatic cancer cells in the dataset obtained from the Gene Expression Omnibus (GEO) database. Although the extracted 107 hypoxia-responsive genes included the genes that were slightly enriched in angiogenic factors, TCGA data analysis revealed that the expression level of endothelial cell (EC) markers did not affect OS. Finally, we selected CA9 and PRELID2 as potential targets for PDAC treatment and elucidated that a CA9 inhibitor, U-104, suppressed pancreatic cancer cell growth more effectively than 5-fluorouracil (5-FU) and PRELID2 siRNA treatment suppressed the cell growth stronger than CA9 siRNA treatment. Thus, we elucidated that specific inhibition of PRELID2 as well as CA9, extracted via exhaustive bioinformatic analyses of clinical datasets, could be a more effective strategy for PDAC treatment.

Pemafibrate inhibited renal dysfunction and fibrosis in a mouse model of adenine-induced chronic kidney disease.

AIMS: Peroxisome proliferator-activated receptor-alpha (PPARα) levels are markedly lower in the kidneys of chronic kidney disease (CKD) patients. Fibrates (PPARα agonists) are therapeutic agents against hypertriglyceridemia and potentially against CKD. However, conventional fibrates are eliminated by renal excretion, limiting their use in patients with impaired renal function. Here, we aimed to evaluate the renal risks associated with conventional fibrates via clinical database analysis and investigate the renoprotective effects of pemafibrate, a novel selective PPARα modulator mainly excreted into the bile. MAIN METHODS: The risks associated with conventional fibrates (fenofibrate, bezafibrate) to the kidneys were evaluated using the Food and Drug Administration Adverse Event Reporting System. Pemafibrate (1 or 0.3 mg/kg/day) was administered daily using an oral sonde. Its renoprotective effects were examined in unilateral ureteral obstruction (UUO)-induced renal fibrosis model mice (UUO mice) and adenine-induced CKD model mice (CKD mice). KEY FINDINGS: The ratios of glomerular filtration rate decreased and blood creatinine increased were markedly higher after conventional fibrate use. Pemafibrate administration suppressed increased gene expressions of collagen-I, fibronectin, and interleukin 1 beta (IL-1ß) in the kidneys of UUO mice. In CKD mice, it suppressed increased plasma creatinine and blood urea nitrogen levels and decreased red blood cell count, hemoglobin, and hematocrit levels, along with renal fibrosis. Moreover, it inhibited the upregulation of monocyte chemoattractant protein-1, IL-1ß, tumor necrosis factor-alpha, and IL-6 in the kidneys of CKD mice. SIGNIFICANCE: These results demonstrated the renoprotective effects of pemafibrate in CKD mice, confirming its potential as a therapeutic agent for renal disorders.

The novel preventive effect of a Japanese ethical Kampo extract formulation TJ-90 (Seihaito) against cisplatin-induced nephrotoxicity.

BACKGROUND AND PURPOSE: Chinese herbal medicine has been developed as the traditional Japanese Kampo medicine, and it has been widely used to cure various symptoms in clinical practice. However, only a few studies are currently available on the effect of the Kampo medicine on renal disease. Nephrotoxicity is one of major side effect of cisplatin, the first metal-based anticancer drug. In the present study, we examined the effect of the Kampo medicine against cisplatin-induced nephrotoxicity (CIN). METHODS: First, we screened the ethical Kampo extract formulation having positive effect against CIN using HK-2 cells. Next, we examined the preventive action of the selected ethical Kampo extract formulation against CIN in vivo using a mouse model. RESULTS: Cisplatin-induced cell death was significantly suppressed by TJ-43 (Rikkunshito) and TJ-90 (Seihaito); however, cisplatin-induced cleaved caspase-3 expression was inhibited only by TJ-90. In an in vivo mouse model of cisplatin-induced kidney injury with dysfunction and increased inflammatory cytokine expression, TJ-90 showed amelioration of these damaging effects. Cisplatin-induced apoptosis and superoxide production were inhibited by treatment with TJ-90. The expression of cleaved caspase-3, 4-hydroxynonenal, and MAPK phosphorylation increased after cisplatin administration, but decreased after the administration of TJ-90. Among 16 crude drug extracts present in Seihaito, Bamboo Culm (Chikujo in Japanese) inhibited cisplatin-induced cell death and cleaved caspase-3 expression in HK-2 cells. Moreover, the anti-tumor effect of cisplatin was not affected by TJ-90 co-treatment in cancer cell lines. CONCLUSION: TJ-90 might have a novel preventive action against CIN through the suppression of inflammation, apoptosis, and oxidative stress without interfering with the anti-tumor effect of cisplatin. Collectively, these findings might contribute to innovations in supportive care for cancer treatment-related side effects.

The role of iron in obesity and diabetes.

Iron is an essential trace metal for all life, but excess iron causes oxidative stress through catalyzing the toxic hydroxy-radical production via the Fenton reaction. The number of patients with obesity and diabetes has been increasing worldwide, and their onset and development are affected by diet. In both clinical and experimental studies, a high body iron content was associated with obesity and diabetes, and the reduction of body iron content to an appropriate level can ameliorate the status and development of obesity and diabetes. Macrophages play an essential role in the pathophysiology of obesity and diabetes, and in the metabolism and homeostasis of iron in the body. Recent studies demonstrated that macrophage polarization is related to adipocyte hypertrophy and insulin resistance through their capabilities of iron handling. Control of iron in macrophages is a potential therapeutic strategy for obesity and diabetes. J. Med. Invest. 69 : 1-7, February, 2022.

Novel roles of HIF-PHIs in chronic kidney disease: the link between iron metabolism, kidney function, and FGF23.

Hanudel et al. investigated the effects of hypoxia-inducible factor-prolyl hydroxylase domain inhibitors (HIF-PHIs) on iron metabolism in a chronic kidney disease (CKD) mouse model and showed that vadadustat, an HIF-PHI, exerted beneficial effects on anemia and iron disorders independently of erythroferrone. Vadadustat also inhibited the progression of CKD and the CKD-associated increase of plasma fibroblast growth factor 23 in CKD mice. This study provides new insights into the action of HIF-PIHs in CKD.

Role of ferroptosis in cisplatin-induced acute nephrotoxicity in mice.

BACKGROUND: Cisplatin is widely used as an antitumor drug for the treatment of solid tumors. However, its use has been limited owing to nephrotoxicity, a major side effect. The mechanism of cisplatin-induced nephrotoxicity (CIN) has long been investigated in order to develop preventive/therapeutic drugs. Ferroptosis is a newly identified form of non-apoptotic regulated cell death induced by iron-mediated lipid peroxidation and is involved in the pathophysiology of various diseases. In this study, we examined the role of ferroptosis in CIN. METHODS: We evaluated the role of ferroptosis in CIN by in vivo experiments in a mouse model. RESULTS: Cisplatin increased the protein expressions of transferrin receptor-1 and ferritin, and iron content in the kidney of mice. In addition, treatment with cisplatin augmented renal ferrous iron and hydroxyl radical levels with co-localization. Mice administered cisplatin demonstrated kidney injury, with renal dysfunction and increased inflammatory cytokine expression; these changes were ameliorated by Ferrostatin-1 (Fer-1), an inhibitor of ferroptosis. The expression of the ferroptosis markers, COX2 and 4-hydroxynonenal (4-HNE), increased with cisplatin administration, and decreased with the administration of Fer-1. By contrast, cisplatin-induced apoptosis and necroptosis were inhibited by treatment with Fer-1. Moreover, deferoxamine, an iron chelator, also inhibited CIN, with a decrease in the expression of COX-2 and 4-HNE. CONCLUSION: Ferroptosis is involved in the pathogenesis of CIN and might be used as a new preventive target for CIN.

Effects of Palonosetron on Nausea and Vomiting Induced by Multiple-Day Chemotherapy: A Retrospective Study.

Patients who undergo multiple-day chemotherapy sessions experience hard-to-treat nausea and vomiting. Currently, there is no effective standard treatment for this condition. This study compared the preventive effect of first-generation 5-hydroxytryptamine 3 receptor antagonists (5-HT3 RAs) and second-generation 5-HT3 RAs palonosetron in multiple-day chemotherapy-induced nausea and vomiting. The design of this study was a retrospective case-control study of patients who received a five-day cisplatin-based chemotherapy and were treated with aprepitant, dexamethasone, granisetron, and ramosetron or palonosetron. The patients were divided into two groups: patients given granisetron and ramosetron (the first-generation group), and those given palonosetron (palonosetron group). The percentage of patients with a complete response or total control was assessed. They were divided into three phases: 0-216 h (overall phase), 0-120 h (remedial phase), and 120-216 h (after phase). The remedial phase was further divided into 0-24 h (early phase) and 24-120 h (later phase). Moreover, the nutritional status of each patient was assessed by noting the patients' total calorie-intake per day and total parenteral nutrition. First-generation 5-HT3 RAs and palonosetron were used for treatment in 18 and 28 patients, respectively. The complete response rate and caloric oral intake of the later phase were higher in the palonosetron group than in the first-generation group. We conclude that palonosetron treatment was more effective than first-generation 5-HT3 RAs in controlling multiple-day chemotherapy-induced nausea and vomiting.

Examination of the antiepileptic effects of valacyclovir using kindling mice- search for novel antiepileptic agents by drug repositioning using a large medical information database.

Despite the availability of more than 20 clinical antiepileptic drugs, approximately 30% of patients with epilepsy do not respond to antiepileptic drug treatment. Therefore, it is important to develop antiepileptic products that function via novel mechanisms. In the present study, we evaluated data from one of the largest global databases to identify drugs with antiepileptic effects, and subsequently attempted to understand the effect of the combination of antiepileptic drugs and valacyclovir in epileptic seizures using a kindling model. To induce kindling in mice, pentylenetetrazol at a dose of 40 mg/kg was administered once every 48 h. Valacyclovir was orally administered 30 min before antiepileptic drug injection in kindled mice, and behavioral seizures were monitored for 20 min following pentylenetetrazol administration. Additionally, c-Fos expression in the hippocampal dentate gyrus was measured in kindled mice. Valacyclovir showed inhibitory effects on pentylenetetrazol-induced kindled seizures. In addition, simultaneous use of levetiracetam and valacyclovir caused more potent inhibition of seizure activity, and neither valproic acid nor diazepam augmented the anti-seizure effect in kindled mice. Furthermore, kindled mice showed increased c-Fos levels in the dentate gyrus. The increase in c-Fos expression was significantly inhibited by the simultaneous use of levetiracetam and valacyclovir. The findings of the present study indicate that a combination of levetiracetam and valacyclovir had possible anticonvulsive effects on pentylenetetrazol-induced kindled epileptic seizures. These results suggest that valacyclovir may have an antiseizure effect in patients with epilepsy.

Dual disruption of eNOS and ApoE gene accelerates kidney fibrosis and senescence after injury.

The relationship between cellular senescence and fibrosis in the kidney is being elucidated and we have identified it as therapeutic target in recent studies. Chronic kidney disease has also become a lifestyle disease, often developing on the background of hypertension and dyslipidemia. In this study, we clarify the effect of interaction between these two conditions on kidney fibrosis and senescence. Wild type mice (WT), apolipoprotein E-/- mice (ApoEKO), and endothelial nitric oxide synthase (eNOS)-/- ApoE-/- mice (DKO) were obtained by breeding. Unilateral ureteral obstruction (UUO) was performed on 8-10 week old male mice and the degree of renal tubular injury, fibrosis and kidney senescence were evaluated. DKO manifested elevated blood pressure, higher total cholesterol and lower HDL than WT. DKO showed sustained kidney injury molecule-1 protein expression. Kidney fibrosis was significantly higher in ApoEKO and DKO. mRNA expression of genes related to kidney fibrosis was the highest in DKO. The mRNA expression of Zinc-α2-Glycoprotein and heme oxygenase-1 were significantly decreased in DKO. Furthermore, mRNA expression of p53, p21 and p16 were increased both in ApoEKO and DKO, with DKO being the highest. Senescence associated ß-gal positive tubule area was significantly increased in DKO. Increased DNA damage and target of rapamycin-autophagy spatial coupling compartments (TASCCs) formation was found in DKO. Mice with endothelial dysfunction and dyslipidemia developed kidney fibrosis and accelerated senescence even in young mice after injury. These data highlight the fact managing lifestyle-related diseases from a young age is important for CKD prevention.

Diphenhydramine may be a preventive medicine against cisplatin-induced kidney toxicity.

Cisplatin is widely used as an anti-tumor drug for the treatment of solid tumors. Unfortunately, it causes kidney toxicity as a critical side effect, limiting its use, given that no preventive drug against cisplatin-induced kidney toxicity is currently available. Here, based on a repositioning analysis of the Food and Drug Administration Adverse Events Reporting System, we found that a previously developed drug, diphenhydramine, may provide a novel treatment for cisplatin-induced kidney toxicity. To confirm this, the actual efficacy of diphenhydramine was evaluated in in vitro and in vivo experiments. Diphenhydramine inhibited cisplatin-induced cell death in kidney proximal tubular cells. Mice administered cisplatin developed kidney injury with significant dysfunction (mean plasma creatinine: 0.43 vs 0.15 mg/dl) and showed augmented oxidative stress, increased apoptosis, elevated inflammatory cytokines, and MAPKs activation. However, most of these symptoms were suppressed by treatment with diphenhydramine. Furthermore, the concentration of cisplatin in the kidney was significantly attenuated in diphenhydramine-treated mice (mean platinum content: 70.0 vs 53.4 µg/g dry kidney weight). Importantly, diphenhydramine did not influence or interfere with the anti-tumor effect of cisplatin in any of the in vitro or in vivo experiments. In a selected cohort of 98 1:1 matched patients from a retrospective database of 1467 patients showed that patients with malignant cancer who had used diphenhydramine before cisplatin treatment exhibited significantly less acute kidney injury compared to ones who did not (6.1 % vs 22.4 %, respectively). Thus, diphenhydramine demonstrated efficacy as a novel preventive medicine against cisplatin-induced kidney toxicity.

Investigation of drugs affecting hypertension in bevacizumab-treated patients and examination of the impact on the therapeutic effect.

BACKGROUND: In patients treated with bevacizumab, hypertension may be a biomarker of therapeutic efficacy. However, it is not clear whether drugs that control blood pressure influence bevacizumab's efficacy. In this study, we investigated drugs that may affect hypertension in bevacizumab-treated patients and examined the impact on the therapeutic effect. PATIENTS AND METHODS: We analyzed 3,724,555 reports from the third quarter of 2010 to the second quarter of 2015. All data were obtained from the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) analysis. In this retrospective cohort study, we investigated a total of 58 patients diagnosed with colorectal cancer and treated for the first time with bevacizumab containing XELOX or mFOLFOX6 at The University of Tokushima Hospital between January 2010 and December 2015. The effect of the treatment was evaluated according to Response Evaluation Criteria in Solid Tumors version 1.0. Thereafter, the effect was confirmed using Gene Expression Omnibus (GEO) and cultured cells. RESULTS: There are few reports in FAERS of hypertension in patients treated with omeprazole on bevacizumab. Based on the chart review, patients who used proton pump inhibitors (PPI) had a lower response to treatment than those who did not (response rate: 25% vs 50%). Furthermore, experiments on GEO and cell lines suggested that induction of vascular endothelial growth factor (VEGF) gene expression by PPIs is the cause of the reduced therapeutic effect. CONCLUSION: PPIs prevent hypertension in bevacizumab-treated patients but may reduce bevacizumab's anti-tumoral effects by inducing VEGF expression.

Deletion of H-ferritin in macrophages alleviates obesity and diabetes induced by high-fat diet in mice.

AIMS/HYPOTHESIS: Iron accumulation affects obesity and diabetes, both of which are ameliorated by iron reduction. Ferritin, an iron-storage protein, plays a crucial role in iron metabolism. H-ferritin exerts its cytoprotective action by reducing toxicity via its ferroxidase activity. We investigated the role of macrophage H-ferritin in obesity and diabetes. METHODS: Conditional macrophage-specific H-ferritin (Fth, also known as Fth1) knockout (LysM-Cre Fth KO) mice were used and divided into four groups: wild-type (WT) and LysM-Cre Fth KO mice with normal diet (ND), and WT and LysM-Cre Fth KO mice with high-fat diet (HFD). These mice were analysed for characteristics of obesity and diabetes, tissue iron content, inflammation, oxidative stress, insulin sensitivity and metabolic measurements. RAW264.7 macrophage cells were used for in vitro experiments. RESULTS: Iron concentration reduced, and mRNA expression of ferroportin increased, in macrophages from LysM-Cre Fth KO mice. HFD-induced obesity was lower in LysM-Cre Fth KO mice than in WT mice at 12 weeks (body weight: KO 34.6 ± 5.6 g vs WT 40.1 ± 5.2 g). mRNA expression of inflammatory cytokines and infiltrated macrophages and oxidative stress increased in the adipose tissue of HFD-fed WT mice, but was not elevated in HFD-fed LysM-Cre Fth KO mice. However, WT mice fed an HFD had elevated iron concentration in adipose tissue and spleen, which was not observed in LysM-Cre Fth KO mice fed an HFD (adipose tissue [µmol Fe/g protein]: KO 1496 ± 479 vs WT 2316 ± 866; spleen [µmol Fe/g protein]: KO 218 ± 54 vs WT 334 ± 83). Moreover, HFD administration impaired both glucose tolerance and insulin sensitivity in WT mice, which was ameliorated in LysM-Cre Fth KO mice. In addition, energy expenditure, mRNA expression of thermogenic genes, and body temperature were higher in KO mice with HFD than WT mice with HFD. In vitro experiments showed that iron content was reduced, and lipopolysaccharide-induced Tnf-α (also known as Tnf) mRNA upregulation was inhibited in a macrophage cell line transfected with Fth siRNA. CONCLUSIONS/INTERPRETATION: Deletion of macrophage H-ferritin suppresses the inflammatory response by reducing intracellular iron levels, resulting in the prevention of HFD-induced obesity and diabetes. The findings from this study highlight macrophage iron levels as a potential therapeutic target for obesity and diabetes.

Fibroblast-specific ERK5 deficiency changes tumor vasculature and exacerbates tumor progression in a mouse model.

The roles of cancer-associated fibroblasts (CAFs) have been studied in the tumor progression, and CAFs are expected to become the new targets for cancer pharmacotherapies. CAFs contribute to tumor cell survival and proliferation, tumor angiogenesis, immune suppression, tumor inflammation, tumor cell invasion and metastasis, and extracellular matrix remodeling. However, detailed mechanisms of how CAFs function in the living system remain unclear. CAFs include α-smooth muscle actin, expressing activated fibroblasts similar to myofibroblasts, and are highly capable of producing collagen. Several reports have demonstrated the contributions of extracellular-signal-regulated kinase 5 (ERK5) in fibroblasts to the fibrotic processes; however, the roles of CAF-derived ERK5 remain unclear. To investigate the roles of CAF-derived ERK5 in the tumor progression, we created mice lacking the ERK5 gene specifically in fibroblasts. Colon-26 mouse colon cancer cells were implanted into the mice subcutaneously, and the histological analyses of the tumor tissue were performed after 2 weeks. Immunofluorescence analyses showed that recipient-derived fibroblasts existed within the tumor tissue. The present study demonstrated that fibroblast-specific ERK5 deficiency exacerbated tumor progression and it was accompanied with thicker tumor vessel formation and the increase in the number of activated fibroblasts. We combined the results of The Cancer Genome Atlas (TCGA) database analysis with our animal studies, and indicated that regulating ERK5 activity in CAFs or CAF invasion into the tumor tissue can be important strategies for the development of new targets in cancer pharmacotherapies.

Novel Hydrophilic Camptothecin Derivatives Conjugated to Branched Glycerol Trimer Suppress Tumor Growth without Causing Diarrhea in Murine Xenograft Models of Human Lung Cancer.

Camptothecin possesses broad antitumor spectra on various cancers. In spite of its marked tumor-suppressing potency, camptothecin is too hydrophobic to be solved in water and therefore not currently in clinical use. CPT-11 (irinotecan) is one of the hydrophilic analogues of camptothecin and widely prescribed. However, its water solubility is still low and furthermore evokes severe diarrhea. Therefore, we designed and synthesized novel highly hydrophilic camptothecin derivatives by conjugating SN38 with branched glycerol trimer (SN38-BGL), which we have been developing as a unique strategy to endow hydrophobic molecule with much hydrophilicity, to maximize the benefit of CPT-11 and minimize the adverse effects. The SN38-BGLs exhibited equivalent or slightly stronger tumor-suppressing effects in murine xenograft human lung cancer models compared to CPT-11. However, neither early- nor late-onset diarrhea was observed when SN38-BGL was administered. Heights of villi in jejunum and ileum were bigger than those from CPT-11-treated mice, indicating that SN38-BGL is less harmful than CPT-11. Ex vivo digestion by liver microsome did not yield SN38 but a couple of other molecules against our expectations, which suggests the involvement of other active metabolites than SN38 and may explain the differences. Hence, SN38-BGLs can be a novel hydrophilic camptothecin derivative without causing severe diarrhea.

Proton pump inhibitors block iron absorption through direct regulation of hepcidin via the aryl hydrocarbon receptor-mediated pathway.

Proton pump inhibitors (PPIs) have been used worldwide to treat gastrointestinal disorders. A recent study showed that long-term use of PPIs caused iron deficiency; however, it is unclear whether PPIs affect iron metabolism directly. We investigated the effect of PPIs on the peptide hepcidin, an important iron regulatory hormone. First, we used the FDA Adverse Event Reporting System database and analyzed the influence of PPIs. We found that PPIs, as well as H2 blockers, increased the odds ratio of iron-deficient anemia. Next, HepG2 cells were used to examine the action of PPIs and H2 blockers on hepcidin. PPIs augmented hepcidin expression, while H2 blockers did not. In fact, the PPI omeprazole increased hepcidin secretion, and omeprazole-induced hepcidin upregulation was inhibited by gene silencing or the pharmacological inhibition of the aryl hydrocarbon receptor. In mouse experiments, omeprazole also increased hepatic hepcidin mRNA expression and blood hepcidin levels. In mice treated with omeprazole, protein levels of duodenal and splenic ferroportin decreased. Taken together, PPIs directly affect iron metabolism by suppressing iron absorption through the inhibition of duodenal ferroportin via hepcidin upregulation. These findings provide a new insight into the molecular mechanism of PPI-induced iron deficiency.

Rho-associated protein kinase and cyclophilin a are involved in inorganic phosphate-induced calcification signaling in vascular smooth muscle cells.

Arterial calcification, a risk factor of cardiovascular events, develops with differentiation of vascular smooth muscle cells (VSMCs) into osteoblast-like cells. Cyclophilin A (CypA) is a peptidyl-prolyl isomerase involved in cardiovascular diseases such as atherosclerosis and aortic aneurysms, and rho-associated protein kinase (ROCK) is involved in the pathogenesis of vascular calcification. CypA is secreted in a ROCK activity-dependent manner and works as a mitogen via autocrine or paracrine mechanisms in VSMCs. We examined the involvement of the ROCK-CypA axis in VSMC calcification induced by inorganic phosphate (Pi), a potent cell mineralization initiator. We found that Pi stimulated ROCK activity, CypA secretion, extracellular signal-regulated protein kinase (ERK) 1/2 phosphorylation, and runt-related transcription factor 2 expression, resulting in calcium accumulation in rat aortic smooth muscle cells (RASMCs). The ROCK inhibitor Y-27632 significantly suppressed Pi-induced CypA secretion, ERK1/2 phosphorylation, and calcium accumulation. Recombinant CypA was found to be associated with increased calcium accumulation in RASMCs. Based on these results, we suggest that autocrine CypA is mediated by ROCK activity and is involved in Pi-induced ERK1/2 phosphorylation following calcification signaling in RASMCs.

[Body iron accumulation in obesity, diabetes and its complications, and the possibility of therapeutic application by iron regulation].

Iron is an essential trace metal element for maintaining vital functions, and it is involved in hemoglobin synthesis, redox reaction, enzyme activity, cell proliferation and apoptosis in various cells. Iron deficient-related diseases represented anemia are well-known, on the other hand, iron overload disease has attracted little attention. Excessive iron produces hydroxyl radicals via Fenton/Haber-Weiss reaction, causing organ damage in hereditary iron overload diseases. Additionally, it has been clarified that iron accumulation is involved in the pathological conditions even in metabolic diseases thought to be unrelated to iron so far. Therefore, the role of iron in the living body has been raised attention again. Recent studies have reported that body iron content is associated with both obesity and diabetes, and iron might be an aggravating factor of obesity and diabetes. We have revealed that iron chelating agent reduced oxidative stress and inflammation, suppressing the development of adipose hypertrophy in KKAy mice. Dietary iron restriction also diminishes oxidative stress, leading to the inhibition of increased albuminuria excretion and glomerular lesions in db/db mice. In this review, we give an outline of the role of iron on obese and diabetes, and diabetic kidney disease, and present the possibility of application to treatment with iron regulation in those disorders.

Iron accumulation causes impaired myogenesis correlated with MAPK signaling pathway inhibition by oxidative stress.

Skeletal muscle atrophy is caused by disruption in the homeostatic balance of muscle degeneration and regeneration under various pathophysiological conditions. We have previously reported that iron accumulation induces skeletal muscle atrophy via a ubiquitin ligase-dependent pathway. However, the potential effect of iron accumulation on muscle regeneration remains unclear. To examine the effect of iron accumulation on myogenesis, we used a mouse model with cardiotoxin (CTX)-induced muscle regeneration in vivo and C2C12 mouse myoblast cells in vitro. In mice with iron overload, the skeletal muscles exhibited increased oxidative stress and decreased expression of satellite cell markers. Following CTX-induced muscle injury, these mice also displayed delayed muscle regeneration with a decrease in the size of regenerating myofibers, reduced expression of myoblast differentiation markers, and decreased phosphorylation of MAPK signaling pathways. In vitro, iron overload also suppressed the differentiation of C2C12 myoblast cells but the suppression could be reversed by superoxide scavenging using tempol. Excess iron inhibits myogenesis via oxidative stress, leading to an imbalance in skeletal muscle homeostasis.-Ikeda, Y., Satoh, A., Horinouchi, Y., Hamano, H., Watanabe, H., Imao, M., Imanishi, M., Zamami, Y., Takechi, K., Izawa-Ishizawa, Y., Miyamoto, L., Hirayama, T., Nagasawa, H., Ishizawa, K., Aihara, K.-I., Tsuchiya, K., Tamaki, T. Iron accumulation causes impaired myogenesis correlated with MAPK signaling pathway inhibition by oxidative stress.

Irinotecan-induced neutropenia is reduced by oral alkalization drugs: analysis using retrospective chart reviews and the spontaneous reporting database.

PURPOSE: SN-38, an active metabolite of irinotecan, is reabsorbed by the intestinal tract during excretion, causing diarrhoea and neutropenia. In addition, the association between blood levels of SN-38 and neutropenia has been reported previously, and the rapid excretion of SN-38 from the intestinal tract is considered to prevent neutropenia. Oral alkalization drugs are used as prophylactic agents for suppressing SN-38 reabsorption. The relationship between oral alkalization drugs and neutropenia, however, has not been well studied. The aim of this study was to investigate the relationship between oral alkalization drugs and neutropenia in irinotecan-treated patients. METHODS AND RESULTS: Patients with cervical or ovarian cancer were administered irinotecan and investigated by medical chart reviews to determine whether oral alkalization drugs were effective at ameliorating irinotecan-induced neutropenia. The drug combination in the oral alkalization drugs-ursodeoxycholic acid, magnesium oxide, and sodium hydrogen carbonate-significantly improved neutrophil counts and reduced dose intensity compared with those of non-users. In the large-scale Japanese Adverse Drug Event Report database, the reporting odds ratio of irinotecan-induced neutropenia was significantly lower when irinotecan had been given in combination with oral alkalization drugs. CONCLUSIONS: These data indicate that oral alkalization drugs may reduce the frequency of neutropenia caused by irinotecan administration, making it possible to increase the dose safely.