DNA methylation of skeletal muscle function-related secretary factors identifies FGF2 as a potential biomarker for sarcopenia.

BACKGROUND: Sarcopenia is characterized by progressive loss of muscle mass and function due to aging. DNA methylation has been identified to play important roles in the dysfunction of skeletal muscle. The aim of our present study was to explore the whole blood sample-based methylation changes of skeletal muscle function-related factors in patients with sarcopenia. METHODS: The overall DNA methylation levels were analysed by using MethlTarget™ DNA Methylation Analysis platform in a discovery set consistent of 50 sarcopenic older adults (aged ≥65 years) and 50 age- and sex-matched non-sarcopenic individuals. The candidate differentially methylated regions (DMRs) were further validated by Methylation-specific PCR (MSP) in another two independent larger sets and confirmed by pyrosequencing. Receiver operating characteristic (ROC) curve analysis was used to determine the optimum cut-off levels of fibroblast growth factor 2 (FGF2)_30 methylation best predicting sarcopenia and area under the ROC curve (AUC) was measured. The correlation between candidate DMRs and the risk of sarcopenia was investigated by univariate analysis and multivariate logistic regression analysis. RESULTS: Among 1149 cytosine-phosphate-guanine (CpG) sites of 27 skeletal muscle function-related secretary factors, 17 differentially methylated CpG sites and 7 differentially methylated regions (DMRs) were detected between patients with sarcopenia and control subjects in the discovery set. Further methylation-specific PCR identified that methylation of fibroblast growth factor 2 (FGF2)_30 was lower in patients with sarcopenia and the level was decreased as the severity of sarcopenia increased, which was confirmed by pyrosequencing. Correlation analysis demonstrated that the methylation level of FGF2_30 was positively correlated to ASMI (r = 0.372, P < 0.001), grip strength (r = 0.334, P < 0.001), and gait speed (r = 0.411, P < 0.001). ROC curve analysis indicated that the optimal cut-off value of FGF2_30 methylation level that predicted sarcopenia was 0.15 with a sensitivity of 84.6% and a specificity of 70.1% (AUC = 0.807, 95% CI = 0.756-0.858, P < 0.001). Multivariate logistic regression analyses showed that lower FGF2_30 methylation level (<0.15) was significantly associated with increased risk of sarcopenia even after adjustment for potential confounders including age, sex, and BMI (adjusted OR = 9.223, 95% CI: 6.614-12.861, P < 0.001). CONCLUSIONS: Our results suggest that lower FGF2_30 methylation is correlated with the risk and severity of sarcopenia in the older adults, indicating that FGF2 methylation serve as a surrogate biomarker for the screening and evaluation of sarcopenia.

Association of AST/ALT (De Ritis) ratio with sarcopenia in a Chinese population of community-dwelling elderly.

Background: The aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio, also known as De Ritis ratio, has been reportedly associated with malnutrition which plays a crucial role in sarcopenia. The aim of this study was to examine the relationship between AST/ALT ratio and sarcopenia in the Chinese community-dwelling elderly. Methods: A cross-sectional study with 2751 participants (1343 men and 1408 women) aged ≥60 years was performed. Appendicular skeletal muscle mass index (ASMI), grip strength, and gait speed were measured to diagnose sarcopenia according to the latest Asian Working Group for Sarcopenia (AWGS) consensus. The association of AST/ALT ratio with sarcopenia was examined using logistic regression analysis. Results: The prevalence of sarcopenia in the present study was 4.4%. AST/ALT ratio was higher in the sarcopenia group than in the non-sarcopenia group (1.30 ± 0.33 vs. 1.16 ± 0.62, P = 0.010). AST/ALT ratio was negatively correlated with the components of sarcopenia, including ASMI, grip strength, and gait speed. Logistic regression analysis indicated that high AST/ALT ratio (>1.20) was associated with increased risk of sarcopenia even after adjustment for potential confounders (adjusted OR = 2.33, 95%CI = 1.48-3.68, P < 0.001). Stratification analyses indicated that the association of high AST/ALT ratio with high risk of sarcopenia was more significant in males and the elderly with ≥70 years. Conclusions: Our findings demonstrate that high AST/ALT ratio is associated with increased risk of sarcopenia in a Chinese population of community-dwelling elderly.

Curcumin Suppresses Metastasis via Sp-1, FAK Inhibition, and E-Cadherin Upregulation in Colorectal Cancer.

Colorectal cancer (CRC) is a serious public health problem that results due to changes of diet and various environmental stress factors in the world. Curcumin is a traditional medicine used for treatment of a wide variety of tumors. However, antimetastasis mechanism of curcumin on CRC has not yet been completely investigated. Here, we explored the underlying molecular mechanisms of curcumin on metastasis of CRC cells in vitro and in vivo. Curcumin significantly inhibits cell migration, invasion, and colony formation in vitro and reduces tumor growth and liver metastasis in vivo. We found that curcumin suppresses Sp-1 transcriptional activity and Sp-1 regulated genes including ADEM10, calmodulin, EPHB2, HDAC4, and SEPP1 in CRC cells. Curcumin inhibits focal adhesion kinase (FAK) phosphorylation and enhances the expressions of several extracellular matrix components which play a critical role in invasion and metastasis. Curcumin reduces CD24 expression in a dose-dependent manner in CRC cells. Moreover, E-cadherin expression is upregulated by curcumin and serves as an inhibitor of EMT. These results suggest that curcumin executes its antimetastasis function through downregulation of Sp-1, FAK, and CD24 and by promoting E-cadherin expression in CRC cells.

[Phylogenetic analysis and expression patterns of tropomyosin in amphioxus].

In amphioxus, we found a mesoderm related gene, tropomyosin, which encodes a protein comprising 284 amino acid residues, sharing high identities with other known Tropomyosin proteins both in vertebrates and invertebrates. Phylogenetically, amphioxus Tropomyosin fell outside the invertebrate clade and was at the base of the vertebrate protein family clade, indicating that it may represent an independent branch. From the early neurula to the larva stage, whole-mount in situ hybridization and histological sections found transcripts of amphioxus tropomyosin gene. Weak tropomyosin expression was first detected in the wall of the archenteron at about 10 hours-post-fertilization neurula stage, while intense expression was revealed in the differentiating presumptive notochord and the muscle. Transcripts of tropomyosin were then expressed in the formed notochord and somites. Gene expression seemed to continue in these developing organs throughout the neurular stages and remained till 72-hours, during the early larval stages. In situ study still showed tropomyosin was also expressed in the neural tube, hepatic diverticulum, notochord and the spaces between myotomes in adult amphioxus. Our results indicated that tropomyosin may play an important role in both embryonic development and adult life.

[Effect of ulinastatin preconditioning on gene expression profile of kidney tissue in a rat sepsis model].

OBJECTIVE: To investigate the modulation effect of ulinastatin (UTI) preconditioning on gene expression of kidney tissue in septic rats by DNA microarrays. METHODS: Forty-five male Wistar rats were divided into control group, sepsis group and UTI group, with 15 rats in each group by means of random number table. Cecal ligation and puncture (CLP) was used to reproduce rat sepsis model. The control group only experienced a simulated operation without CLP. In UTI group the rats were treated with intramuscular injection of UTI (100 kU/kg). In sepsis group and control group intramuscular balanced solution (5 ml/kg) was given. Gene expression spectrum was studied with oligonucleotide gene expression profile microarray that contained 22 523 rat cDNA clones to detect the changes in gene expression pattern of rat kidney tissue 24 hours after CLP. Genes with fluorescent signal of Cy3/Cy5 of ratio average (RA)>2.0 or RA<0.5 were identified as differential genes, then those highly correlated to sepsis and UTI were screened by means of related computer software, and their relationship was analyzed. RESULTS: Three hundred and twenty-seven differential genes were found in sepsis group/control group, accounting for 1.45%, and among them 181 genes showed up-regulation,with 78 known functional genes, and 146 genes showed down-regulation, with 51 known functional genes. One hundred and twenty-seven differential genes were found in UTI group/sepsis group, accounting for 0.56%, and among them 41 genes showed up-regulation, with 14 known functional genes, and 86 genes showed down-regulation, with 37 known functional genes. Twenty-two genes were down-regulated in sepsis group/control group but up-regulated in UTI group/sepsis group, with 11 known functional genes, 51 genes were up-regulated in sepsis group/control group but down-regulated in UTI group/sepsis group, with 24 known functional genes. CONCLUSION: UTI preconditioning can alleviate the damage of kidney tissue in rat sepsis model, thus showing a protective effect on kidney, and the mechanism may be attributable to effect of UTI on modulation of immune reaction, energy metabolism, inflammatory reaction, signal transduction, defense reaction, oxidation-reduction reaction, DNA replication, and transcription related genes.

Moisture vapor transmission rates of various transparent dressings at different temperatures and humidities.

BACKGROUND: Transparent dressings are commonly used to cover central venous catheter sites. However, it has been suggested that they might not allow adequate moisture vapor transmission, resulting in local moistness that promotes bacterial growth. We compared the moisture vapor transmission rates (MVTRs) of different, currently used transparent and traditional gauze dressings. We aimed to determine the MVTRs at different temperatures and humidities. METHODS: The dressings were used to seal 50-ml plastic centrifuge tubes containing 20 ml deionized water: Tubes in group 1 were covered with 12 layers of ordinary gauze, group 2 with IV3000, group 3 with OPSITE FLEXIGRID, group 4 with 3M HP Tegaderm, and group 5 with 3M Tegaderm. The tubes were placed upright in an artificial climate cabinet, so that the dressings were not touching the water, in order to simulate the conditions of medical dressings in contact with the skin. The average MVTRs were determined under different conditions. MVTRs were also determined with tubes from groups 2 - 5 laid on their sides, allowing the dressings to touch the water, so simulating contact of the dressings with sweating skin, or wounded skin with exudates. We also calculated the dressings' self-reactive abilities by comparing their MVTRs in contact with the water surface with those when not in contact with the water surface. RESULTS: Group 1 demonstrated the highest MVTR, followed by groups 2, 4, 3 and 5 under conditions simulating contact of the dressings with normal skin at the following temperatures and humidities: 20 degrees C/30%, 20 degrees C/60%, 20 degrees C/90%, 37 degrees C/30%, 37 degrees C/60% and 37 degrees C/90%. When the relative humidity (RH) increased, the MVTRs decreased. The MVTRs differed significantly among different dressings and RHs: At high temperature (37 degrees C) and high humidity (90%), the MVTR of the transparent dressings in group 2 was higher than that of group 1 (P < 0.01). The reactive MVTR was highest in group 2 (10.2 - 16.3 times > MVTR) while that of group 4 was second highest (2.6 - 9.6 times > MVTR). CONCLUSIONS: RH and temperature had significant effects on the MVTRs of different dressings. The IV3000 transparent dressing used in group 2 was as effective as ordinary gauze. These results suggest that increased infection rates due to low MVTRs might not be a problem. The clinical implications of these observations for catheter-related infections need to be further investigated in multicenter studies.

[Isolation, phylogenetic analysis and developmental expression parttern of AmphiRab23b in amphioxus].

The hedgehog (Hh) pathway plays an important role during the embryonic development and is related to the progression of cancers. Rab23 is a crucial functional molecule in Hh pathway. However, there is no report about amphioxus Rab23 up to now except the annotations of two isoforms in the genome of Florida lancelet (Branchiostoma floridae). Here a 2062 bp full-length cDNA sequence of the Rab23, AmphiRab23b, was isolated from Chinese amphioxus (Branchiostoma belcheri), which included the UTRs and an open reading frame of 714 bp, encoding a protein of 237 amino acids. Phylogenetic analysis suggested that AmphiRab23b falled outside the vertebrate clade. But sequence analysis indicated that this putative AmphiRab23b protein contained a specific Rab23_lke domain, which implied that Rab23 gene was functional conservative during evolution. And its developmental expression pattern showed that AmphiRab23b was expressed in the differentiating neural plate and alimentary canal, as the same as the expression pattern of the homologous vertebrate genes, which suggested that AmphiRab23b may function in the development of nervous system and alimentary canal.

Changes of serum beta-endorphin by programmed exercise training are correlated with improvement of clinical symptoms and quality of life in female mitral valve prolapse syndrome.

BACKGROUND: Mitral valve prolapse (MVP) is a common entity in female population. Although this is a minor disease, it may cause annoying symptoms that impair quality of life (QOL), and no established therapy for this problem. The aim of this study isto examine whether programmed exercise training by treadmill in female MVP syndrome would improve clinical symptoms and QOL. METHODS: An interventional study of 39 females with MVP syndrome with treadmill exercise endurance training for 12 weeks. Every individual received training for 30 min a day, thrice a week for 12 weeks. Baseline and post-exercise at 12 weeks serum beta-endorphins were measured. Symptom improvement was assessed by the MVP symptom checklist questionnaire and the Euro-QOL-5D was used to measure QOL improvement in these females. RESULTS: The mean serum beta-endorphin increased from 0.5 to 1.68 ng/ml (p = 0.001) in the exercise group (n = 18) after 12 weeks exercise, whereas the control group (n = 21) did not show any significant changes (0.44 vs. 0.43 ng/ml). Major symptoms of MVP such as chest pain, palpitation, fatigue were improved significantly by the assessment of MVP symptom checklist. The QOL of the exercised females also showed significant changes. CONCLUSIONS: Through programmed exercise training in these MVP females, the improvement of symptoms and QOL is parallel to the increase of serum beta-endorphin. This result implicates that MVP females should initiate exercise to tackle this annoying problem.