Dermal advanced glycation end-product accumulation is associated with sarcopenia-related measures in middle-aged and older men.

AIMS: Sarcopenia is the age-associated atrophy of muscles, and advanced glycation end-products (AGEs) accumulate in patients with age-associated diseases. We aimed to investigate the relationship between AGE accumulation in the skin and sarcopenia in middle-aged and older Japanese people. MATERIALS AND METHODS: We enrolled 240 participants in this cross-sectional study. The participants consisted of 120 men (mean age 68.8 ± 10.1 years) and 120 women (mean age 67.4 ± 9.0 years). The level of dermal AGE accumulation in the forearms was measured using skin autofluorescence (SAF) and many parameters associated with sarcopenia, including grip strength and thigh muscle cross-sectional area (CSA), were evaluated during medical check-ups at the Ehime University Hospital. RESULTS: Grip strength and thigh muscle CSA were significantly higher in men than women, but mean SAF did not significantly differ between them. There were significant correlations of age, height, C-reactive protein, glycated hemoglobin, grip strength, and thigh muscle CSA with SAF in men, but only age in women. Multivariate analysis showed that SAF was significantly independently associated with low grip strength in men (ß =-0.211, p =0.046). The men were then allocated to four groups according to their grip strength and thigh muscle CSA, and SAF was significantly higher in the lowgrip strength/low-thigh muscle CSA group than in the high-grip strength/high-thigh muscle CSA group (low/low group 2.25 ± 0.37 and high/high group 1.93 ± 0.36, p =0.001). CONCLUSIONS: SAF is associated with sarcopenia-related measures, especially grip strength, in middle-aged and older Japanese men, but not women.

Unilateral lower limb atrophy associated with glomus tumors: a case report.

BACKGROUND: Glomus tumors are soft tissue neoplasms comprised of glomus cells, vasculature, and smooth muscle cells, which occur commonly in a single subungual area of the digits, and their main clinical features include severe paroxysmal pain, localized tenderness, and cold hypersensitivity. CASE PRESENTATION: A 47-year-old Japanese man had suffered from chronic progressive paroxysmal shooting pain in his right leg since childhood. He avoided putting weight on his right foot whenever he walked. The frequency of paroxysmal pain and the number of tender points both gradually increased with age, and his right leg gradually atrophied. Magnetic resonance imaging of the lower extremity demonstrated multiple gadolinium-enhanced nodules that corresponded with his tender points. Excisional biopsy relieved his pain and provided a histopathological diagnosis of glomus tumors. CONCLUSION: This case suggests that small glomus tumors located in deep tissue may cause disuse atrophy because of their long delay before diagnosis. Clinicians should consider the potential for glomus tumors when patients exhibit unilateral lower limb muscular atrophy with pain.

Biological and clinical implications of retinoic acid-responsive genes in human hepatocellular carcinoma cells.

BACKGROUND & AIMS: Accumulating data from epidemiological and experimental studies have suggested that retinoids, which are vitamin A derivatives, exert antitumor activity in various organs. We performed a gene screening based on in silico analysis of retinoic acid response elements (RAREs) to identify the genes facilitating the antitumor activity of retinoic acid (RA) and investigated their clinical significance in hepatocellular carcinoma (HCC). METHODS: In silico analysis of RAREs was performed in the 5-kb upstream region of EST clusters. Chromatin immunoprecipitation analysis of the retinoic acid receptors and gene expression analysis were performed in HuH7, HepG2, and MCF7 cells treated with all-trans RA (ATRA). mRNA expression of RA-responsive genes was investigated using tumor and non-tumor tissues of clinical HCC samples from 171 patients. The association between gene expression and survival of patients was examined by Cox regression analysis. RESULTS: We identified 201 candidate genes with promoter regions containing consensus RARE and finally selected 26 RA-responsive genes. Of these, downregulation of OTU domain-containing 7B (OTUD7B) gene, which was upregulated by ATRA, in tumor tissue was associated with a low cancer-specific survival of HCC patients. Functional analyses revealed that OTUD7B negatively regulates nuclear factor κB (NF-κB) signaling and decreases the survival of HCC cells. CONCLUSIONS: We identified RA-responsive genes which are regulated by retinoid signal and found that low-OTUD7B mRNA expression is associated with a poor prognosis for HCC patients. OTUD7B-mediated inhibition of NF-κB signaling may be an effective target for antitumor therapy for HCC.

Expansion of intronic GGCCTG hexanucleotide repeat in NOP56 causes SCA36, a type of spinocerebellar ataxia accompanied by motor neuron involvement.

Autosomal-dominant spinocerebellar ataxias (SCAs) are a heterogeneous group of neurodegenerative disorders. In this study, we performed genetic analysis of a unique form of SCA (SCA36) that is accompanied by motor neuron involvement. Genome-wide linkage analysis and subsequent fine mapping for three unrelated Japanese families in a cohort of SCA cases, in whom molecular diagnosis had never been performed, mapped the disease locus to the region of a 1.8 Mb stretch (LOD score of 4.60) on 20p13 (D20S906-D20S193) harboring 37 genes with definitive open reading frames. We sequenced 33 of these and observed a large expansion of an intronic GGCCTG hexanucleotide repeat in NOP56 and an unregistered missense variant (Phe265Leu) in C20orf194, but we found no mutations in PDYN and TGM6. The expansion showed complete segregation with the SCA phenotype in family studies, whereas Phe265Leu in C20orf194 did not. Screening of the expansions in the SCA cohort cases revealed four additional occurrences, but none were revealed in the cohort of 27 Alzheimer disease cases, 154 amyotrophic lateral sclerosis cases, or 300 controls. In total, nine unrelated cases were found in 251 cohort SCA patients (3.6%). A founder haplotype was confirmed in these cases. RNA foci formation was detected in lymphoblastoid cells from affected subjects by fluorescence in situ hybridization. Double staining and gel-shift assay showed that (GGCCUG)n binds the RNA-binding protein SRSF2 but that (CUG)(6) does not. In addition, transcription of MIR1292, a neighboring miRNA, was significantly decreased in lymphoblastoid cells of SCA patients. Our finding suggests that SCA36 is caused by hexanucleotide repeat expansions through RNA gain of function.

A close association of abnormal iron metabolism with steatosis in the mice fed a choline-deficient diet.

Hepatic iron overload has been frequently observed in the liver of patients with chronic liver diseases. In this study, the effect of hepatic fatty acid accumulation on the iron metabolism was investigated. Mice fed a choline-deficient diet developed severe steatosis associated with increased total amount of non-heme iron in the liver. Hepatic lipid contents were well correlated with the iron amount. The choline-deficient diet significantly downregulated hepcidin while increases in hemojuvelin and transferrin receptor 2 and a decrease in Tmprss6 expression were observed. Moreover, ferroportin expression was downregulated in the livers of choline-deficient mice while increases in transferrin receptor 1 and divalent metal transporter 1 and a decrease in ferritin expression were observed in accordance with increased hepatic iron content. The expression of hepcidin and ferroportin mRNA was negatively correlated to hepatic lipid concentrations. These results suggest that enhanced dietary iron intake and reduced hepatic iron efflux occur in the mice fed a choline-deficient diet. In addition, a possible link between hepatic iron and lipid metabolism is also suggested.

Involvement of ETS1 in thioredoxin-binding protein 2 transcription induced by a synthetic retinoid CD437 in human osteosarcoma cells.

CD437, a synthetic retinoid, has a potent antitumor activity, in which an RAR-independent mechanism may be involved. Our previous study showed that CD437 transcriptionally upregulates the expression of thioredoxin-binding protein 2 (TBP2), leading to c-Jun N-terminal kinase 1 (JNK1)-mediated apoptosis. In the present study, we addressed the mechanism, by which CD437 induces TBP2 mRNA expression. CD437 efficiently caused the cell death of human osteosarcoma cells via apoptosis. CD437 also induced JNK1 activation through the upregulation of TBP2 mRNA, in consistent with our previous observation. A luciferase reporter assay for TBP2 promoter activation suggested that CD437-regulated TBP2 mRNA transcription requires the region between -400 and -300, which contains multiple possible ETS-binding sites. Finally, we demonstrated CD437-dependent recruitment of ETS1 transcription factor to this region by chromatin immunoprecipitation assay. These data suggest that ETS1 is involved in CD437-induced TBP2 mRNA expression in human osteosarcoma MG-63 cells.

Suppressive effects of retinoids on iron-induced oxidative stress in the liver.

BACKGROUND & AIMS: We previously reported that impaired retinoid signaling in the liver causes steatohepatitis and hepatocellular carcinoma. Recently, oxidative stress induced by hepatic iron overload has emerged as an important factor for the progression of liver disease in patients with chronic hepatitis C, alcoholic liver disease, and nonalcoholic steatohepatitis. In this study, the relationship between retinoid signaling and iron metabolism in the liver was investigated. METHODS: The effect of retinoids on the iron metabolism was examined in HuH7 cells treated with all-trans retinoic acid and acyclic retinoid NIK-333. In in vivo experiments, we used the mice expressing the dominant negative form of retinoic acid receptor alpha gene under the control of albumin enhancer/promoter (RAR-E Tg) and iron-overloaded wild mice fed with retinoid-deficient and retinoid-excess diets. RESULTS: Hepatic iron accumulation and increased expression of hemojuvelin were observed in RAR-E Tg mouse liver. Retinoid treatment significantly suppressed expression of hemojuvelin and mildly suppressed expression of transferrin receptor type 2 and hepcidin, accompanied by decreased hepatic iron content and iron-induced oxidative stress in vitro and in vivo. Overexpression of hemojuvelin in HuH7 hepatoma cells led to a significant increase in cellular iron content. CONCLUSIONS: Our results suggest that retinoids are involved in hepatic iron metabolism through transcriptional regulation of hemojuvelin. This study demonstrated a novel functional role of retinoids in preventing iron-induced oxidative stress in the liver.

Hepatic differentiation of human bone marrow-derived mesenchymal stem cells by tetracycline-regulated hepatocyte nuclear factor 3beta.

UNLABELLED: Human bone marrow-derived mesenchymal stem cells (BM-MSCs) are expected to be a potential source of cells for transplantation. Although recent reports have shown that isolated MSCs can differentiate into hepatocytes, the efficiency of differentiation is insufficient for therapeutic application. To circumvent this problem, it is necessary to understand the mechanisms of hepatic differentiation of human BM-MSCs. Hepatocyte nuclear factor 3beta (HNF3beta), a forkhead/winged helix transcription factor, is essential for liver development. In the present study, we established a tetracycline (Tet)-regulated expression system for HNF3beta in UE7T-13 BM-MSCs. HNF3beta expression significantly enhanced expression of albumin, alpha-fetoprotein (AFP), tyrosine amino transferase (TAT) and epithelial cell adhesion molecule (EpCAM) genes. The differentiated cells showed hepatocyte-specific functions including glycogen production and urea secretion. During treatment with the Tet-on system for 8 days, over 80% of UE7T-13 cells turned out to express albumin. Furthermore, the combination of Tet with basic fibroblast growth factor (bFGF) efficiently induced the genes such as albumin and TAT, which are associated with maturity of hepatocytes; however, it suppressed genes such as AFP and EpCAM, which are associated with immaturity of hepatocytes, suggesting that Tet-induced HNF3beta expression sensitizes BM-MSCs to bFGF signals. Finally, the results of the present study suggest that down-regulation of Wnt/beta-catenin signals caused by translocation of beta-catenin to cytoplasmic membrane is associated with hepatic differentiation of human BM-MSCs. CONCLUSION: HNF3beta expression induced efficient differentiation of UE7T-13 human BM-MSCs.

Synthetic retinoid CD437 induces mitochondria-mediated apoptosis in hepatocellular carcinoma cells.

Retinoids play an important role in the regulation of cell growth and death. Synthetic retinoid CD437 reportedly induces apoptosis in various cancer cell lines. However, the mechanism of inducing apoptosis in hepatocellular carcinoma (HCC) cells by this agent remains to be clarified. In this study, we investigated the signaling pathway by which CD437 induces apoptosis in HCC cell lines. Apoptosis of six human HCC cell lines was induced by treatment with CD437. Caspase-3 and -9 were activated by CD437, suggesting that the apoptosis is mediated by mitochondrial pathways. Consistent with these findings, the treatment with CD437 upregulated Bax protein, downregulated Bcl-2 protein and released cytochrome c into the cytoplasm. Moreover, rhodamine123 staining revealed mitochondrial depolarization in the cells treated with CD437. These data of the present study suggest that CD437 induces apoptosis in HCC cells via mitochondrial pathways.

CD437 induces apoptosis in ovarian adenocarcinoma cells via ER stress signaling.

A synthetic retinoid, CD437, has been shown to exert potent anti-tumor activity against various types of cancer cell lines, regardless of their sensitivities to natural retinoids. We herein demonstrate that CD437 induces endoplasmic reticulum (ER) stress, including the up-regulation of CHOP, BIP and GADD34 mRNA through ER stress transducer (PERK and IRE1alpha) activation in an ovarian adenocarcinoma cell line, SKOV3. It was also shown that CD437 induced the CHOP and GADD34 expressions in another four ovarian adenocarcinoma cell lines, indicating that CD437 functions as an ER stress inducer in these cell lines. Moreover, the siRNA-mediated knockdown of inducible CHOP expression prevented the cytotoxic effect of CD437. These results suggest that ER stress plays an important role in the mechanism by which CD437 induces apoptosis in ovarian adenocarcinoma cells.