Hidekuni Inadera

Increase in Circulating Levels of Monocyte Chemoattractant Protein-1 with Aging

Monocyte chemoattractant protein-1 (MCP-1) is a member of chemokines with chemoattractant activity for monocytes, T cells, mast cells, and basophils. Precursor mRNA or protein was detected at high levels in the lesions of several diseases, such as pulmonary fibrosis, rheumatoid arthritis, atherosclerosis, and some types of tumors. The regulation of MCP-1 production and the role of this chemokine in pathophysiologic states, however, remain largely unknown. In this study, using an enzyme-linked immunosorbent assay (ELISA), we measured the circulating MCP-1 levels in 405 healthy Japanese subjects of various ages, eliciting a profound age-dependent MCP-1 increase. Multivariate regression analysis revealed that significant predictors of MCP-1 value for males were age (p = 0.033) and serum triglyceride (p = 0.039). For females, age was also a significant predictor (p = 0.00002). One possible explanation is that the plasma MCP-1 concentration might reflect the existence of atherosclerosis, although the plasma MCP-1 concentration from patients with coronary artery disease or cerebrovascular accidents appears not to differ from age-matched, disease-free controls. This is the first report linking an increase in a particular chemokine level with aging.

Molecular Analysis of the Inhibition of Monocyte Chemoattractant Protein-1 Gene Expression by Estrogens and Xenoestrogens in MCF-7 Cells1

Xenoestrogens (XEs) are a diverse group of chemicals that mimic estrogenic actions and may have adverse effects on human health. The influence of these compounds on cytokine production or immune system function remains unclear. In this study we have examined the effects of 17β-estradiol (E2) and XEs on chemoattractant cytokine (chemokine) production and analyzed the molecular mechanism. Monocyte chemoattractant protein-1 (MCP-1), also termed monocyte chemotactic and activating factor, is a member of the chemokine family and attracts mainly blood monocytes. Human mammary tumor cell line MCF-7 cells produce a large quantity of MCP-1 in response to interleukin-1α (IL-1α). Addition of E2 to MCF-7 cells inhibited MCP-1 production in a dose-dependent manner. XEs, bisphenol A, and NP also inhibited MCP-1 production, although the potency was 3–4 orders of magnitude lower than that of E2. E2, bisphenol A, and NP inhibited MCP-1 messenger RNA expression in MCF-7 cells. Two closely located nuclear factor-κB sites, A...

Developmental origins of obesity and type 2 diabetes: molecular aspects and role of chemicals

Obesity is a leading risk factor for impaired glucose tolerance and type 2 diabetes (T2D). Although the cause of the obesity epidemic is multi-factorial and not entirely clear, the recent acceleration in incidence is too rapid to be accounted for only by genetics, the wide availability of calorie-rich foods, and increasingly sedentary lifestyles. Accumulating data suggest that the important causes of the obesity epidemic may be related to developmental and early life environmental conditions. The concept of the developmental origins of health and disease (DOHaD) suggests that adverse influences early in development, particularly during intrauterine life, may result in permanent changes in the physiology and metabolism of the infant, which in turn result in an increased risk of non-communicable diseases in adulthood. For example, undernutrition during pregnancy and rapid postnatal weight gain are associated with obesity and T2D in the adult offspring. Moreover, increasing evidence suggests that early-life exposure to a wide range of chemicals has a significant impact on the causes of metabolic disorders. Although the underlying molecular mechanisms remain to be determined, these factors can affect epigenetic processes, such as DNA methylation, allowing the developmental environment to modulate gene transcription. The objective of this review article was to summarize recent progress in the biomedical implications of the DOHaD concept, focusing on the pathogenesis of obesity and T2D, and to discuss a future direction for preventive strategies from a public health perspective.

Diabetic Control and Progression of Retinopathy in Elderly Patients: Five‐Year Follow‐up Study

Objective: To assess whether control of diabetes mellitus is as important in the elderly as in young and middle‐aged diabetic patients in terms of progression of retinopathy.

Gene expression profile analysis of the mouse liver during bacteria-induced fulminant hepatitis by a cDNA microarray system

Fulminant hepatic failure (FHF) is a disease characterized by sudden and severe impairment of liver function. To elucidate the mechanism involved in FHF, we adopted a murine model of FHF by administrating mice with heat-killed Propionibacterium acnes (P. acnes), followed by a low dose of lipopolysaccharide (LPS), and analyzed the dynamic change of gene expression profile of the murine liver using an in-house cDNA microarray system which contained most of the cDNAs encoding chemokines/cytokines and their receptors (33 chemokines/21 chemokine receptors, 28 cytokines/35 cytokine receptors) as well as 230 liver related proteins mostly selected by serial analysis of gene expression (SAGE). Among them, 335 genes were found to differ by more than 2-fold in at least one time point comparing with normal liver. Hierarchical cluster analysis revealed that except for a few genes, such as heme oxygenase (HO)-1 and nicotinamide N-methyltransferase (NNMT) of which expression increased, the expression of most of the genes encoding drug metabolizing enzymes decreased with the progress of the disease. The expression of the genes encoding chemokines/cytokines was dramatically changed, such as Mig, IP-10, RANTES, TNF-alpha, and IFN-gamma. In addition, the expression of those that were not previously linked to this murine model was also identified to be changed. These include endogenous IL-18 binding protein (IL-18BP), CXCL16 (the ligand of Bonzo, CXCR6) as well as ESTs. Taken together this study has shown the systemic and comprehensive gene expression profile during FHF and may contribute to better understanding of the mechanism of FHF.

Abnormalities in the fatty acid composition of the postmortem entorhinal cortex of patients with schizophrenia, bipolar disorder, and major depressive disorder.

Previous studies of postmortem orbitofrontal cortex have shown abnormalities in levels of n-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA), in individuals with schizophrenia, bipolar disorder, and major depressive disorder (MDD). We have previously measured PUFA levels in the postmortem hippocampus from patients with schizophrenia or bipolar disorder and control subjects; however, we found no significant differences between the groups except for small changes in n-6 PUFAs. Furthermore, our study of the postmortem amygdala showed no significant differences in major PUFAs in individuals with schizophrenia, bipolar disorder, or MDD in comparison with controls. In the present study, we investigated whether there were any changes in PUFAs in the entorhinal cortexes of patients with schizophrenia (n=15), bipolar disorder (n=15), or MDD (n=15) compared with unaffected controls (n=15) matched for characteristics including age and sex. In contrast to previous studies of the orbitofrontal cortex and hippocampus, we found no significant differences in major PUFAs. However, we found a 34.3% decrease in docosapentaenoic acid (DPA) (22:5n-3) in patients with MDD and an 8.7% decrease in docosatetraenoic acid (22:4n-6) in those with schizophrenia, compared with controls. Changes in PUFAs in patients with these psychiatric disorders may be specific to certain brain regions.

WISP-2 is a secreted protein and can be a marker of estrogen exposure in MCF-7 cells

As many structurally diverse chemicals have been reported to function as estrogens, evaluations for estrogenicity of compounds are of widespread concern. Recently, we identified WISP-2 (Wnt-1 inducible signaling pathway protein 2) as a novel estrogen-inducible gene in human breast cancer cells. In this study, we examined whether WISP-2 could be utilized as a marker for screening environmentally relevant compounds for estrogenicity. In MCF-7 cells, progesterone, dexamethasone, tri-iodothyronine, and 2,3,7,8-tetrachlorodibenzo-p-dioxin did not regulate the expression of WISP-2, indicating that its induction is highly specific for hormones that interact with the estrogen receptor. Western blot analysis detected WISP-2 protein induced by 17-beta-estradiol (E2), not only in the cell lysates but also in the culture supernatant of exposed cells, indicating that WISP-2 was a secreted protein. The induction of WISP-2 protein by E2 in the culture supernatant was dose-dependent with estimated EC(50) levels between 10 and 100 pM. Our results demonstrated the capacity to screen environmental compounds for estrogenicity via WISP-2 induction.

Type I hyperlipoproteinemia caused by lipoprotein lipase defect in lipid-interface recognition was relieved by administration of medium-chain triglyceride

We have previously reported lipoprotein lipase with a defect of lipid-interface recognition in a patient with type I hyperlipoproteinemia. In this patient, lipoprotein lipase from post-heparin plasma (PHP) hydrolyzed monomeric substrate tributyrin, but scarcely hydrolyzed triolein emulsified with Triton X-100 and that in very-low-density lipoproteins ([VLDL] d < 1.006 g/mL), and did not bind to VLDL. The triglyceride (TG) level of this patient did not decrease to less than 1,000 mg/dL with a low-fat diet (1,400 kcal containing 10 g fat/d). When the patient took 30 g medium-chain TG (MCT) in addition to the 1,400-kcal diet, her serum TG level decreased to 250 mg/dL and her clinical signs improved. The low clearance rate of serum TG with heparin injection improved after intake of MCT. Caproic acid levels were maintained at 1.4% and 2.6% in chylomicrons and VLDL after MCT intake, respectively. The patients lipoprotein lipase hydrolyzed triolein emulsified with 2% tricaprin at the same rate as that of control lipoprotein lipase. The patients lipoprotein lipase-catalyzed hydrolyzing rate of triolein in chylomicrons obtained after MCT administration was also enhanced up to 70% of that of control lipoprotein lipase. These findings suggest that hypertriglyceridemia caused by lipoprotein lipase with a defect in lipid-interface recognition could be relieved with the administration of medium-chain TG, and that one of the mechanisms of this effect might be a modification of TG-rich lipoproteins by MCT.

Molecular mechanisms of hyperthermia-induced apoptosis enhanced by withaferin A.

Hyperthermia is a good therapeutic tool for non-invasive cancer therapy; however, its cytotoxic effects are not sufficient. In the present study, withaferin A (WA), a steroidal lactone derived from the plant Withania somnifera Dunal, has been investigated for its possible enhancing effects on hyperthermia-induced apoptosis. In HeLa cells, treatment with 0.5 or 1.0μM WA at 44°C for 30min induced significant apoptosis accompanied by decreased intracellular GSH/GSSG ratio and caspase-3 activation, while heat or WA alone did not induce such changes. The upregulation in apoptosis was significantly inhibited by glutathione monoethyl ester, a cell permeable glutathione precursor. Mitochondrial transmembrane potentials were dramatically decreased by the combined treatment, with increases in pro-apoptotic Bcl-2-family proteins tBid and Noxa, and downregulation of antiapoptotic Bcl-2 and Mcl-1. Combined treatment with hyperthermia and WA induced significant increases in JNK phosphorylation (p-JNK), and decreases in the phosphorylation of ERK (p-ERK) compared with either treatment alone. These results suggest that WA enhances hyperthermia-induced apoptosis via a mitochondria-caspase-dependent pathway; its underlying mechanism involves elevated intracellular oxidative stress, mitochondria dysfunction, and JNK activation.

Docosahexaenoic Acid Is an Independent Predictor of All-Cause Mortality in Hemodialysis Patients

Background: Dietary n–3 polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA) and eicosapentaenoic acid have been shown to reduce cardiovascular mortality. Patients on hemodialysis (HD) have a very high mortality from cardiovascular disease. Fish consumption reduces all-cause mortality in patients on HD. Moreover, n–3 PUFAs, especially DHA levels in red blood cells (RBCs), are associated with arteriosclerosis in patients on HD. The aim of this study was to determine whether DHA levels in RBCs predict the mortality of patients on HD in a prospective cohort study. Methods: A cohort of 176 patients (64.1 ± 12.0 (mean ± SD) years of age, 96 men and 80 women) under HD treatment was studied. The fatty acid composition of their RBCs was analyzed by gas chromatography. Results: During the study period of 5 years, 54 deaths occurred. After adjustment for 10 confounding factors, the Cox hazard ratio of all-cause mortality of the patients on HD in the highest DHA tertile (>8.1%, 15 deaths) was 0.43 (95% CI 0.21–0.88) compared with those patients in the lowest DHA tertile (<7.2%, 21 deaths). Conclusion: The findings suggest that the level of DHA in RBCs could be an independent predictor of all-cause mortality in patients on HD.