Exercise increases the binding of MEF2A to the Cpt1b promoter in mouse skeletal muscle

AIM

Muscle-type carnitine palmitoyltransferase 1 (CPT1b) plays an important role in skeletal muscle mitochondrial fatty acid β-oxidation. A myocyte-specific enhancer factor (MEF2) site that binds MEF2A in the promoter of Cpt1b has been identified. The aim of this study is to determine whether Cpt1b expression is regulated by MEF2 in response to exercise training.

METHODS

Twelve male, 14-week-old C57BL/6 mice underwent 6 weeks of treadmill exercise at 12 m min(-1), for 60 min day(-1), 5 days week(-1). Quadriceps muscles were analysed by real-time PCR, Western blot, chromatin immunoprecipitation.

RESULTS

The binding of MEF2A to the Cpt1b promoter was elevated in the quadriceps muscle of mice after 6-week aerobic exercise intervention. The repressor partner of MEF2, histone deacetylase 5 (HDAC5), binding to the Cpt1b promoter was decreased by exercise training. In C2C12 myoblast, MEF2A overexpression increased the Cpt1b mRNA expression and the Cpt1b promoter transcriptional activity, which were suppressed by HDAC5. Moreover, exercise training induced MEF2A hyperacetylation, which is strongly associated with its enhanced DNA-binding ability. The binding of both HDAC5 and histone deacetylase 3 (HDAC3) to MEF2A was decreased by exercise training. Overexpression of HDAC5 decreased exogenous MEF2A acetylation level with an increased binding of endogenous HDAC3 to MEF2A. Finally, the phosphorylation levels of HDAC5 Ser259 and Ser498 were increased by exercise training. Exercise training decreased the abundance of HDAC5 in the nucleus while increasing its abundance in the cytoplasm.

CONCLUSION

Our results indicated that exercise-induced CPT1b expression was at least in part mediated by HDAC5/MEF2A interaction.

Submicron-scale surface architecture of tricalcium phosphate directs osteogenesis in vitro and in vivo

A current challenge of synthetic bone graft substitute design is to induce bone formation at a similar rate to its biological resorption, matching bone's intrinsic osteoinductivity and capacity for remodelling. We hypothesise that both osteoinduction and resorption can be achieved by altering surface microstructure of beta-tricalcium phosphate (TCP). To test this, two TCP ceramics are engineered with equivalent chemistry and macrostructure but with either submicron- or micron-scale surface architecture. In vitro, submicron-scale surface architecture differentiates larger, more active osteoclasts--a cell type shown to be important for both TCP resorption and osteogenesis--and enhances their secretion of osteogenic factors to induce osteoblast differentiation of human mesenchymal stem cells. In an intramuscular model, submicrostructured TCP forms 20 % bone in the free space, is resorbed by 24 %, and is densely populated by multinucleated osteoclast-like cells after 12 weeks; however, TCP with micron-scale surface architecture forms no bone, is essentially not resorbed, and contains scarce osteoclast-like cells. Thus, a novel submicron-structured TCP induces substantial bone formation and is resorbed at an equivalent rate, potentially through the control of osteoclast-like cells.

A miRNA-binding-site SNP of MSX1 is Associated with NSOC Susceptibility

MSX1 is a favorable candidate gene for susceptibility to non-syndromic orofacial clefts (NSOCs). However, the roles of MSX1 genetic variants in the development of NSOC are controversial and vary among human populations. In the present study, the roles of 4 potentially functional single-nucleotide polymorphisms (SNPs) of MSX1 (rs12532 in 3′-untranslated region [UTR], and rs3821947, rs3821949, and rs4464513 in 5′ upstream) were investigated in a case-control study of 602 NSOC cases and 605 healthy controls. The findings showed that rs12532 located within 3′-UTR of MSX1 could influence the risk of developing NSOC. Individuals who carried the variant genotype (rs12532AA genotype) showed a decreased possibility of developing NSOC (AA vs. GG: OR = 0.69, 95% CI = [0.49, 0.98]). Interestingly, similar effects were also observed on cleft lip with palate (CLP), in a stratified analysis (allelic comparison-12532A allele vs. 12532G allele, OR = 0.80, 95% CI = [0.66, 0.99]; genotypic comparison-AA vs. GG, OR = 0.58 95% CI = [0.37, 0.91]). Sequence analysis indicated that this SNP might alter the binding ability of miR-3649, confirmed by luciferase activity assay showing a lower expression level of rs12532 A allele compared with that of the G allele ( p < .001 for 293A and COS7 cell lines). Furthermore, an in vivo study showed that MSX1 expression among individuals carrying the AA genotype of rs12532 was markedly lower than that in those with the GG genotype, while the inverse correlation was observed for miR-3649, thus providing a possible interaction between MSX1 and miR-3649 in the etiology of NSOC. Taken together, these findings indicate that SNPs in the miRNA-binding sites might play an important role in the development of NSOCs. Furthermore, if confirmed in subsequent studies, the polymorphisms may be considered as additional markers for the evaluation of infants’ risk of NSOCs.

Poly(trimethylene carbonate) and biphasic calcium phosphate composites for orbital floor reconstruction: a feasibility study in sheep

In the treatment of orbital floor fractures, bone is ideally regenerated. The materials currently used for orbital floor reconstruction do not lead to the regeneration of bone. Our objective was to render polymeric materials based on poly(trimethylene carbonate) (PTMC) osteoinductive, and to evaluate their suitability for use in orbital floor reconstruction. For this purpose, osteoinductive biphasic calcium phosphate (BCP) particles were introduced into a polymeric PTMC matrix. Composite sheets containing 50 wt% BCP particles were prepared. Also laminates with poly(D,L-lactide) (PDLLA) were prepared by compression moulding PDLLA films onto the composite sheets. After sterilisation by gamma irradiation, the sheets were used to reconstruct surgically-created orbital floor defects in sheep. The bone inducing potential of the different implants was assessed upon intramuscular implantation. The performance of the implants in orbital floor reconstruction was assessed by cone beam computed tomography (CBCT). Histological evaluation revealed that in the orbital and intramuscular implantations of BCP containing specimens, bone formation could be seen after 3 and 9 months. Analysis of the CBCT scans showed that the composite PTMC sheets and the laminated composite sheets performed well in orbital floor reconstruction. It is concluded that PTMC/BCP composites and PTMC/BCP composites laminated with PDLLA have osteoinductive properties and seem suitable for use in orbital floor reconstruction.

Mesohepatectomy for centrally located liver tumours

BACKGROUND

Mesohepatectomy (MH) avoids unnecessary sacrifice of functional parenchyma compared with extended hepatectomy (EH). The aim of this study was to compare the results of MH with those of EH in the management of centrally located liver tumours (CLLTs).

METHODS

All patients with CLLTs treated by liver resection between 2005 and 2011 were enrolled in this retrospective study. The decision to use MH or EH was made on an individual basis. Outcomes of the procedures were compared and a classification system for MH was devised consisting of four types, with type IV representing the most complex procedure.

RESULTS

MH was performed in 292 patients and EH in 138. MH was associated with a longer duration of operation (P < 0.001), higher intraoperative transfusion rate (P < 0.001) and lower complication rates (P = 0.001) compared with EH. There were no significant differences in hepatic inflow occlusion rate (P = 0.075), blood loss (P = 0.241) and length of hospital stay (P = 0.804) between the two groups. Type IV lesions had the longest duration of operation, greatest blood loss, and highest intraoperative transfusion and morbidity rates (all P < 0.050).

CONCLUSION

MH is a feasible and safe alternative to EH in selected patients with CLLTs. The proposed classification system may be useful in guiding the surgical treatment of CLLTs.

Total knee arthroplasty treatment of active tuberculosis of the knee: a review of 10 cases

OBJECTIVE

To discuss the surgical methods of total knee arthroplasty (TKA) in the patients with active tuberculosis of the knee and find out its curative effect after TKA.

PATIENTS AND METHODS

We analyzed 10 patients with active tuberculosis of the knee who received TKA in our department from March 2006 to March 2010, whose ages were from 22 to 64 years old (average age was 40.6 ± 1 years). The following parameters were measured in the pre- and post-operation periods: HSS score, range of motion (ROM). From x-ray to find out post-operate curative effect of TKA.

RESULTS

All cases had pain and elevated ESR. Deep vein thrombosis (DVT) and nerve damage were not found in these cases. There were 4 cases that had sinuses on the skin: the skin healed before the operation took place. Pre-operation HSS average scores were 25.0 ± 2. All patients received TKA by the para-patellar medial approach. Eight cases were followed-up for 6-28 months; the average follow-up period was 14 ± 0.5 months. Post-operation we took an HSS score and X-rays to find out its curative effect after TKA operation. There were also no patients with dislocation, aseptic loosening or fracture of prosthesis, although 1 case had recurrence. Post-operation's HSS average scores were 86.75 ± 5.45. The average ROM was improved to 95 ± 5°.

CONCLUSIONS

Recent clinical results indicate that TKA is effective to treat the patients with active tuberculosis of the knee joint. TKA can significantly improve the function of the joint and relieve pain, improving patients' living conditions.

Association study of vascular endothelial growth factor gene polymorphisms with ectopic pregnancy in Chinese women

OBJECTIVE

The purpose of this study is to evaluate potential associations between vascular endothelial growth factor (VEGF) gene polymorphisms and ectopic pregnancy (EP) in Chinese women.

MATERIALS AND METHODS

This was a case-control study wherein 192 women with a history of EP were compared to 210 post-menopausal controls with two pregnancies and no EP for the genotyping of VEGF polymorphisms. Genotyping of the VEGF gene polymorphisms at -460C/T, -1 154G/A, -2578C/A and +936C/T were performed by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

No significant differences were found in genotype and allele distributions of the -460C/T, +936C/T polymorphisms between cases and controls. Compared with the -1154G/G genotype, the -1154(A/A+G/A) genotype could significantly reduce the risk of developing EP. For the -2578C/A polymorphism, the A/A+C/A geno- type could significantly decrease the risk of developing EP, compared with the C/C genotype. The haplotype analysis suggested that the TAA (VEGF -460/-1154/-2578) and CAA haplotypes could significantly decrease the risk of developing EP compared with the haplotype of TGC.

CONCLUSION

The -1154A or -2578A alleles of VEGF gene could significantly decrease the risk of EP and might be po- tentially protective factors for EP development in Chinese women.

Calcitonin receptor gene polymorphism in cCinese Xinjiang Han and Uygur women with primary osteoporosis

CONTEXT

Osteoporosis is a systemic disease with a strong genetic component. Calcitonin receptors (CTR) are involved in maintaining calcium homeostasis. There is no consensus whether CTR gene polymorphism plays a role in affecting pathogenesis of osteoporosis.

OBJECTIVE

The objective of this study was to investigate genetic susceptibility of calcitonin receptor gene polymorphism (genotypes and allele frequencies) to primary osteoporosis between Han and Uygur patients and healthy controls in the Chinese Xinjiang region.

DESIGN

This was a cross-sectional study conducted in an academic hospital.

SUBJECTS

Between 2010 and 2012 a total of 404 female patients with primary osteoporosis (200 Han and 204 Uygur) and 316 healthy control subjects (160 Han and 156 Uygur) were recruited to determine the distribution of C/T single nucleotide polymorphism of the CTR gene. PCR-restriction fragment length polymorphism was used at the 1377-bp site.

RESULTS

The frequency of polymorphic C/T alleles of the calcitonin receptor gene in each group fit the Hardy-Weinberg equilibrium model. There was no statistically significant difference in genotypes (P = 0.922) or allele frequency (P = 0.654) between the Xinjiang Han postmenopausal osteoporosis patients and the controls. Similarly, there was no difference in genotypes (P = 0.897) or allele frequency (P = 0.825) between Xinjiang Uygur postmenopausal osteoporosis patients and the controls. Moreover, there was no significant difference (P = 0.86) between the combination of both ethnic groups and controls. In contrast, compared to these two ethnic groups, Han CC type accounted for 67.8%, CT 30.0%, and TT 2.2%, whereas Uighur CC type accounted for 55.6%, CT 33.3%, and TT 11.2%, which is statistically significant between Han and Uygur CTR genotypes (P = 0.006). Allele frequency of C accounted for 82.8% and T for 17.2% in Han, whereas C accounted for 72.2% and T for 27.8% in Uygur (P = 0.001).

CONCLUSION

There was no statistically significant difference in CTR gene nucleotide sequence polymorphisms at 1377-bp between Chinese Xinjiang Han and Uygur patients with primary osteoporosis, suggesting that this CTR gene polymorphism may not affect incidence of osteoporosis. However, there was a significant difference in CTR gene nucleotide sequence polymorphism at the 1377-bp site between Chinese Xinjiang Han and Uygur, but the importance of this difference needs further study.

[Exploring the relationship between secreted frizzled-related protein 1 and chronic periodontitis]

OBJECTIVE

This study detects the expression of secreted frizzled-related protein 1 (SFRP1) in healthy patients and patients with chronic periodontitis (CP) and explores the relationship between SFRP1 and the occurrence and development of CP.

METHODS

First, 28 patients forming the CP group were further divided into mild, moderate, and severe CP subgroups according to clinical attachment loss (CAL) data. Ten healthy volunteers were recruited in the control group. Gingival crevicular fluid (GCF) was collected from all of the patients, and the concentration of SFRP1 in the GCF samples was detected using enzyme-linked immunosorbent assay. Next, gingival lesions were obtained from 22 patients in the CP group and healthy gingival tissues were obtained from the 10 healthy patients in the control group. Immunohistochemical analysis for SFRP1 was used to analyze the correlation between the expression of SFRP1 and the severity of CP based on staining intensities.

RESULTS

The concentration of SFRP1 in GCF samples taken from of the CP group (281.07 ng x L(-1) +/- 33.37 ng x L(-1)) was significantly higher than that in samples taken from the control group (245.30 ng x L(-1) +/- 35.69 ng x L(-1)) (P < 0.05). A significant positive correlation was observed between the concentration of SFRP1 in GCF and CAL (r = 0.651, P < 0.001). Furthermore, the SFRP1 scores in the CP groups (4.500 +/- 0.913) were significantly higher than those in the control group (2.800 +/- 1.135) (P < 0.001). SFRP1 scores did not vary significantly among the CP subgroups (P > 0.05).

CONCLUSION

SFRP1 expression in the CP groups was significantly higher than that in the control group. Thus, SFRP1 may play a significant role in the development of CP.

Revealing the contribution of Cytochrome P450 to salt-sensitive hypertension using DNA microarray

BACKGROUND

Salt sensitivity is an important cause of hypertension which is a major public health problem. This study aimed to investigate the contribution of Cytochrome P450 (CYP) to salt-sensitive hypertension with microarray data and bioinformatics analysis.

METHODS

Gene expression data set GSE4800 was downloaded from Gene Expression Omnibus database, including 6 gene chips from 3 Dahl salt sensitive (DS) rat samples and 3 Lewis (LEW) rat samples. Raw data were preprocessed and normalized, and then differentially expressed genes (DEGs) were identified with Limma package. Interaction network was constructed by employing STRING (Search Tool for the Retrieval of Interacting Genes) tool. GO (Gene Ontology) enrichment analysis was performed using FuncAssociate tool and pathway analysis was carried out by EASE (Expressing Analysis Systematic Explorer). BLAST (Basic Local Alignment Search Tool) was applied to explore the sequence homology among CYP3A genes in rat and human based on multiple alignments.

RESULTS

A total of 1264 DEGs, including 1082 up-regulated genes and 182 down-regulated genes were identified between DS and LEW samples. CYP3A2 and CYP3A9 were selected to construct the protein interaction network, which comprised 1653 pairs of interaction relationship among 100 genes. Functional analysis showed that CYP3A2 and CYP3A9 were most significantly related to oxidation reduction and metabolism of xenobiotics by cytochrome P450. Furthermore, the CYP3A2 and CYP3A9 genes in rats had high homology with genes CYP3A4and CYP3A5 in human beings.

CONCLUSIONS

CYP3A4 and CYP3A5 may contribute to salt-sensitive hypertension in human which may act as biomarkers for this disease.

A first generation compact microbeam radiation therapy system based on carbon nanotube X-ray technology

We have developed a compact microbeam radiation therapy device using carbon nanotube cathodes to create a linear array of narrow focal line segments on a tungsten anode and a custom collimator assembly to select a slice of the resulting wedge-shaped radiation pattern. Effective focal line width was measured to be 131 μm, resulting in a microbeam width of ∼300 μm. The instantaneous dose rate was projected to be 2 Gy/s at full-power. Peak to valley dose ratio was measured to be >17 when a 1.4 mm microbeam separation was employed. Finally, multiple microbeams were delivered to a mouse with beam paths verified through histology.

Molecular modelling on small molecular CDK2 inhibitors: an integrated approach using a combination of molecular docking, 3D-QSAR and pharmacophore modelling

Cyclin-dependent kinase 2 (CDK2) has been identified as an important target for developing novel anticancer agents. Molecular docking, three-dimensional quantitative structure-activity relationship (3D-QSAR) and pharmacophore modelling were combined with the ultimate goal of studying the structure-activity relationship of CDK2 inhibitors. The comparative molecular similarity indices analysis (CoMSIA) model constructed based on a set of 3-aminopyrazole derivatives as CDK2 inhibitors gave statistically significant results (q (2) = 0.700; r (2) = 0.982). A HypoGen pharmacophore model, constructed using diverse CDK2 inhibitors, also showed significant statistics ([Formula: see text]Cost = 61.483; RMSD = 0.53; Correlation coefficient = 0.98). The small residues and error values between the estimated and experimental activities of the training and test set compounds proved their strong capability of activity prediction. The structural insights obtained from these two models were consistent with each other. The pharmacophore model summarized the important pharmacophoric features required for protein-ligand binding. The 3D contour maps in combination with the comprehensive pharmacophoric features helped to better interpret the structure-activity relationship. The results will be beneficial for the discovery and design of novel CDK2 inhibitors. The simplicity of this approach provides expansion to its applicability in optimizing other classes of small molecular CDK2 inhibitors.

Relationship between body fat distribution and upper airway dynamic function during sleep in adolescents

INTRODUCTION

The obstructive sleep apnea syndrome (OSAS) is associated with increased visceral adipose tissue (VAT) in adults; however, few studies have evaluated VAT in relation to upper airway function in adolescents. We hypothesized that increased neck circumference (NC) and VAT would be associated with increased upper airway collapsibility.

METHODS

Adolescents (24 obese patients with OSAS, 22 obese control patients, and 29 lean control patients) underwent abdominal magnetic resonance imaging, and measurement of upper airway pressure-flow relationships in the activated and hypotonic upper airway states.

RESULTS

Patients with OSAS had a greater activated slope of the pressure-flow relationship (SPF) than control groups (P < 0.001), whereas hypotonic SPF was greater in both obese groups compared with lean control patients (P = 0.01). NC and VAT were greater in obese control patients and those with OSAS than in lean control patients (P < 0.001), but did not differ between obese patients with OSAS and obese control patients. In lean control patients and those with OSAS, increased NC was associated with increased activated SPF, whereas in obese control patients it was associated with decreased activated SPF (P = 0.03). In contrast, increased NC was associated with increased hypotonic SPF in all groups (P < 0.001). There was no significant effect of VAT on either activated or hypotonic SPF for any of the three groups.

CONCLUSIONS

Increased neck circumference was associated with increased upper airway collapsibility in adolescents in the hypotonic but not activated state. These data suggest that obese adolescents without OSAS, despite a narrowed upper airway from adipose tissue, are protected from developing OSAS by upper airway neuromotor activation. Neither neck circumference nor visceral adipose tissue is useful in predicting upper airway collapsibility in obese adolescents.

Molecular cloning, expression and regulation analysis of the interleukin-6 (IL-6) gene in goose adipocytes

1. Interleukin-6 (IL-6) is a multifunctional cytokine involved in lipid metabolism in adipose tissue. The objective of the study was to identify and characterize the IL-6 gene in the goose. 2. A full-length coding sequence (CDS) of the goose (Anser anser) IL-6 gene was cloned that encoded a 234-amino acid peptide containing a 38-amino acid signal peptide, an IL-6/G-CSF/MGF family consensus pattern and four conserved α-helices. The mature goose IL-6 showed 74% and 39% identities to that of chicken and human, respectively. 3. Quantitative real-time PCR analysis showed that the goose IL-6 was predominantly expressed in liver and was up-regulated in adipocytes by lipopolysaccharide (LPS) and oleic acid.

Improved post-prandial ghrelin response by nateglinide or acarbose therapy contributes to glucose stability in Type 2 diabetic patients

BACKGROUND

Recent studies highlight an important role of ghrelin in glucose homeostasis, while the association between ghrelin regulation and glucose fluctuation is unclear.

AIM

We compared the effects of two postprandial hypoglycemic agents on ghrelin response and determined the contribution of ghrelin response to glucose stability in Type 2 diabetic (T2DM) patients.

SUBJECTS AND METHODS

Forty newly- diagnosed T2DM patients were randomly allocated to receive nateglinide or acarbose for 4 weeks, with twenty body mass index (BMI)-matched normoglycemic subjects as controls. Mean glucose values and daily average glucose excursion were assessed using continuous glucose monitoring system. Serum ghrelin levels were determined by enzyme-linked immunosorbent assay.

RESULTS

T2DM patients had similar fasting ghrelin levels (p=0.546), while their postprandial ghrelin suppressions at 30 min and 120 min were reduced as compared to BMI-matched normoglycemic controls (p<0.01). Both nateglinide and acarbose increased post-prandial ghrelin suppression at 120 min and reduced ghrelin area under the curve (AUCGHRL) (p<0.05), while only nateglinide increased postprandial ghrelin suppression at 30 min (p<0.01), which was positively correlated with the increased early-phase insulin secretion by 4 weeks of nateglinide therapy (r=0.48, p=0.05). The decrease in AUCGHRL was positively correlated with the decrease in daily average glucose excursion and mean glucose values either by 4 weeks of nateglinide or acarbose therapy (p<0.05).

CONCLUSIONS

Both nateglinide and acarbose increase post-prandial ghrelin suppression. Improved ghrelin regulation is most likely to play a role in glucose stability in T2DM patients with nateglinide or acarbose therapy.