[Characterization of mutational pattern in patients with Ph negative myeloproliferative neoplasms]

OBJECTIVE

To characterize the molecular profile in patients with Ph negative myeloproliferative neoplasms (MPN) by exploring 49 gene mutations.

METHODS

Targeted gene sequencing were performed to analyze 49 MPN-associated genes in 51 patients with Ph negative MPN, of which CARL (exon 9), NPM1 (exon 12) and CEBPA (TAD, BZIP domains) were investigated by using Sanger sequencing simultaneously, while FLT3-ITD was assessed by PCR method.

RESULTS

Mutations were detected in 73.5% (36/49) of genes, and the mutational rates of JAK2-V617F, CALR (exon 9) and MPL were 60.8%(31/51), 7.8%(4/51) and 7.8%(4/51) respectively, whereas the mutational rates of ASXL1, SETBP1, and SF3B1 were around 10%. In addition, 96.1% (49/51) of patients harbored at least one mutation, and more than half of the patients (52.9%, 27/51) possessed 3 or 4 gene mutations. The amount of gene mutations was significantly higher in patients with JAK2-V617F mutation than those without JAK2-V617F or CALR (exon 9) mutation (P<0.05). The last finding was that there was no statistically significant difference in the amount of mutations among four MPN subtypes (PV, ET, PMF, and MPN-U).

CONCLUSION

Most patients with Ph negative MPN possesses three or more gene mutations, with various mutational profiles.

Twist1 promotes breast cancer invasion and metastasis by silencing Foxa1 expression

The heterogeneous breast cancers can be classified into different subtypes according to their histopathological characteristics and molecular signatures. Foxa1 expression is linked with luminal breast cancer (LBC) with good prognosis, whereas Twist1 expression is associated with basal-like breast cancer (BLBC) with poor prognosis owing to its role in promoting epithelial-to-mesenchymal transition (EMT), invasiveness and metastasis. However, the regulatory and functional relationships between Twist1 and Foxa1 in breast cancer progression are unknown. In this study, we demonstrate that in the estrogen receptor (ERα)-positive LBC cells Twist1 silences Foxa1 expression, which has an essential role in relieving Foxa1-arrested migration, invasion and metastasis of breast cancer cells. Mechanistically, Twist1 binds to Foxa1 proximal promoter and recruits the NuRD transcriptional repressor complex to de-acetylate H3K9 and repress RNA polymerase II recruitment. Twist1 also silences Foxa1 promoter by inhibiting AP-1 recruitment. Twist1 expression in MCF7 cells silenced Foxa1 expression, which was concurrent with the induction of EMT, migration, invasion and metastasis of these cells. Importantly, restored Foxa1 expression in these cells largely inhibited Twist1-promoted migration, invasion and metastasis. Restored Foxa1 expression did not change the Twist1-induced mesenchymal cellular morphology and the expression of Twist1-regulated E-cadherin, β-catenin, vimentin and Slug, but it partially rescued Twist1-silenced ERα and cytokeratin 8 expression and reduced Twist1-induced integrin α5, integrin β1 and MMP9 expression. In a xenografted mouse model, restored Foxa1 also increased Twist1-repressed LBC markers and decreased Twist1-induced BLBC markers. Furthermore, Twist1 expression is negatively correlated with Foxa1 in the human breast tumors. The tumors with high Twist1 and low Foxa1 expressions are associated with poor distant metastasis-free survival. These results demonstrate that Twist1's silencing effect on Foxa1 expression is largely responsible for Twist1-induced migration, invasion and metastasis, but less responsible for Twist1-induced mesenchymal morphogenesis and expression of certain EMT markers.

Porous tantalum seeded with bone marrow mesenchymal stem cells attenuates steroid-associated osteonecrosis

OBJECTIVE

Bone marrow mesenchymal stem cells (BMMSCs) have been widely applied in osteonecrosis. However, lack of biomechanical support limited application of BMMSCs. And porous tantalum (PTA) has been identified as a cell-friendly scaffold for bone regeneration. Herein, we aimed to investigate the efficacy of PTA seeded with BMMSCs in the treatment of osteonecrosis.

MATERIALS AND METHODS

After the production of PTA seeded with BMMSCs, MTT and GFP were performed to identify the proliferation and adhesion of BMMSCs respectively, which was further examined by scanning electron microscopy (SEM). And real-time PCR was also used to determine mRNA level of osteogenic markers, including Alp, OCN, OPN, Col I and Runx-2 in BMMSCs. Nineteen adult rabbits were applied for building steroid-associated osteonecrosis (SAON) models. Bone formation rate (BFR) and mineral apposition rate (MAR) were determined. And Goldner Trichrome Staining was used in these SAON models, which further confirmed the efficacy of PTA seeded with BMMSCs in SAON.

RESULTS

PTA seeded with BMMSCs showed excellent biocompatibility. Additionally, SEM assay showed that BMMSCs adhered tightly and spread fully in the pores of PTA. Next, the expression of ALP and OPN mRNA in BMMSCs were significantly (p < 0.05) higher in the PTA-treated group compared to those in the PTA-untreated group. Furthermore, compared to those treated by only PTA, the dynamic bone formation in rabbits treated by PTA seeded with BMMSCs was significantly increased (p < 0.001) at both week 3rd and week 6th.

CONCLUSIONS

The product, PTA seeded with BMMSCs, was successfully produced, and was determined as high efficacy for treatment of steroid-associated osteonecrosis. PTA seeded with BMMSCs may afford a promising option for treating osteonecrosis.

Prevalence of vitamin D insufficiency among adolescents and its correlation with bone parameters using high-resolution peripheral quantitative computed tomography

Vitamin D deficiency and insufficiency are highly prevalent among adolescents in Hong Kong, which is a sub-tropical city with ample sunshine. Vitamin D level is significantly correlated with key bone density and bone quality parameters. Further interventional studies are warranted to define the role of vitamin D supplementation for improvement of bone health among adolescents.

INTRODUCTION

The relationship between bone quality parameters and vitamin D (Vit-D) status remains undefined among adolescents. The aims of this study were to evaluate Vit-D status and its association with both bone density and bone quality parameters among adolescents.

METHODS

Three hundred thirty-three girls and 230 boys (12-16 years old) with normal health were recruited in summer and winter separately from local schools. Serum 25(OH) Vit-D level, bone density and quality parameters by Dual Energy X-ray Absorptiometry (DXA) and High-Resolution peripheral Quantitative Computed Tomography (HR-pQCT), dietary calcium intake, and physical activity level were assessed.

RESULTS

Sixty-four point seven percent and 11.4 % of subjects were insufficient [25 ≤ 25(OH)Vit-D ≤ 50 nmol/L] and deficient [25(OH)Vit-D < 25 nmol/L] in Vit-D, respectively. The mean level of serum 25(OH)Vit-D in summer was significantly higher than that in winter (44.7 ± 13.6 and 35.9 ± 12.6 nmol/L, respectively) without obvious gender difference. In girls, areal bone mineral density (aBMD) and bone mineral content (BMC) of bilateral femoral necks, cortical area, cortical thickness, total volumetric bone mineral density (vBMD), and trabecular thickness were significantly correlated with 25(OH)Vit-D levels. In boys, aBMD of bilateral femoral necks, BMC of the dominant femoral neck, cortical area, cortical thickness, total vBMD, trabecular vBMD, BV/TV, and trabecular separation were significantly correlated with 25(OH)Vit-D levels.

CONCLUSION

Vit-D insufficiency was highly prevalent among adolescents in Hong Kong with significant correlation between Vit-D levels and key bone density and bone quality parameters being detected in this study. Given that this is a cross-sectional study and causality relationship cannot be inferred, further interventional studies investigating the role of Vit-D supplementation on improving bone health among adolescents are warranted.

Knockdown of eIF3a ameliorates cardiac fibrosis by inhibiting the TGF-β1/Smad3 signaling pathway

Cardiac fibroblasts are key effector cells in the pathogenesis of cardiac fibrosis. The eukaryotic translation initiation factor (eIF) 3a is the largest subunit of the eIF3 complex and has been involved in renal fibrosis. However, the precise role of eIF3a in myofibroblast differentiation and cardiac fibrosis remains unknown. Accordingly, in our present study, we tested the expression of eIF3a in transforming growth factor β1 (TGF-β1)-induced rat CFs and found that eIF3a was upregulated in TGF-β1-induced rat CFs. Then the role and mechanism of eIF3a in cardiac fibrosis were explored. Our results found that the eIF3a expression was significantly up-regulated in TGF-β1-induced CFs. Knockdown of eIF3a significantly inhibited TGF-β1-induced CF proliferation, as well as suppressed the expression levels of α-smooth muscle actin (α-SMA) and SM22α. Mechanistically, knockdown of eIF3a attenuated TGF-β1-induced Smad3 activation in CFs. In summary, our present study firstly demonstrated that silencing eIF3a might alleviate TGF-β1-induced cardiac fibrogenesis in CFs by inhibiting Smad3 activation, and suggest that eIF3a may be positioned as a new and promising target for the prevention and treatment of cardiac fibrosis.

Common neurodegenerative pathways in obesity, diabetes, and Alzheimer's disease

Cognitive decline in chronic diabetic patients is a less investigated topic. Diabetes and obesity are among the modifiable risk factors for Alzheimer's disease (AD), the most common form of dementia. Studies have identified several overlapping neurodegenerative mechanisms, including oxidative stress, mitochondrial dysfunction, and inflammation that are observed in these disorders. Advanced glycation end products generated by chronic hyperglycemia and their receptor RAGE provide critical links between diabetes and AD. Peripheral inflammation observed in obesity leads to insulin resistance and type 2 diabetes. Although the brain is an immune-privileged organ, cross-talks between peripheral and central inflammation have been reported. Damage to the blood brain barrier (BBB) as seen with aging can lead to infiltration of immune cells into the brain, leading to the exacerbation of central inflammation. Neuroinflammation, which has emerged as an important cause of cognitive dysfunction, could provide a central mechanism for aging-associated ailments. To further add to these injuries, adult neurogenesis that provides neuronal plasticity is also impaired in the diabetic brain. This review discusses these molecular mechanisms that link obesity, diabetes and AD. This article is part of a Special Issue entitled: Oxidative Stress and Mitochondrial Quality in Diabetes/Obesity and Critical Illness Spectrum of Diseases - edited by P. Hemachandra Reddy.

[The expression of transcription factors Snail and Slug in epithelial-mesenchymal transition of human lens epithelial cells induced by transforming growth factor-β2]

OBJECTIVE

To investigate the expression of transcription factors snail and slug in epithelial mesenchymal transition (EMT) of human lens epithelial cells (HLEC) induced by transforming growth factor-β2 (TGF-β2).

METHODS

Experimental research. HLEC were treated with different concentrations of TGF-β2 (1.0 and 10.0 μg/L) for different time. The morphological changes were observed under inverted microscope. The expression and cellular localization of snail and slug were evaluated by immunofluorescence. Expressions of snail, slug, E-Cadherin and α-SMA were further determined by Western blot analysis. Single factor analysis of variance, rank sum test and Pearson correlation were used for statistical analysis.

RESULTS

Cultured HLEC were polygonal monolayer cells with tight intercellular adhesion closely and patchy distribution. After treatment of different doses of TGF-β2 for 24 h, HLEC became isolated, exhibited long spindle-like shape as fibroblastic phenotype. The immunofluorescence staining indicated that snail and slug were localized in the nuclei. The expressions of snail and slug appeared to be positive correlative to TGF-β2 dose (snail protein expression: 0.74±0.16, 1.13±0.03, 1.54±0.18 and slug protein expression: 1.96±0.02, 3.12±0.09, 4.07±0.12 in HLEC treated with 0.1, 1.0 and 10 μg/L TGF-β2 respectively) (χ(2)=9.62,P=0.022;F=241.10,P<0.01). In addition, the expression of α-SMA and E-Cadherin showed the similar form (α-SMA protein expression: 0.87±0.04, 1.42±0.11, 2.17±0.36 and E-Cadherin protein expression: 2.50±0.36, 1.65±0.32, 0.41±0.14 in HLEC treated with 0.1, 1.0 and 10.0 μg/L TGF-β2 respectively) (χ(2)=9.97,P=0.019;F=19.99,P<0.01). All Pearson correlation coefficient were close to 1. The expression of snail and slug in HLEC were also increased with extending duration of TGF-β2 (1.0 μg/L). The expression levels of both proteins were modestly up-regulated at 8 hours, robustly increased at 24 h, reached peak at 48h and began to decline at 72 h (snail protein expression: 0.90±0.13, 1.43±0.14, 1.96±0.27, 1.57±0.16 and slug protein expression: 0.91±0.36, 1.24±0.16, 2.44±0.26, 1.43±0.16 in HLEC treated with 1.0 μg/L TGF-β2 for 8 h, 24 h, 48 h and 72 h respectively) (F=12.49,P=0.001;F=14.03,P<0.01).

CONCLUSION

Transcription factors snail and slug might be time and dose-dependently involved in in-vitro TGF-β2-induced EMT of HLEC. (Chin J Ophthalmol, 2016, 52: 285-290).

Promoting inflammatory lymphangiogenesis by vascular endothelial growth factor-C (VEGF-C) aggravated intestinal inflammation in mice with experimental acute colitis

Angiogenesis and lymphangiogenesis are thought to play a role in the pathogenesis of inflammatory bowel diseases (IBD). However, it is not understood if inflammatory lymphangiogenesis is a pathological consequence or a productive attempt to resolve the inflammation. This study investigated the effect of lymphangiogenesis on intestinal inflammation by overexpressing a lymphangiogenesis factor, vascular endothelial growth factor-C (VEGF-C), in a mouse model of acute colitis. Forty eight-week-old female C57BL/6 mice were treated with recombinant adenovirus overexpressing VEGF-C or with recombinant VEGF-C156S protein. Acute colitis was then established by exposing the mice to 5% dextran sodium sulfate (DSS) for 7 days. Mice were evaluated for disease activity index (DAI), colonic inflammatory changes, colon edema, microvessel density, lymphatic vessel density (LVD), and VEGFR-3mRNA expression in colon tissue. When acute colitis was induced in mice overexpressing VEGF-C, there was a significant increase in colonic epithelial damage, inflammatory edema, microvessel density, and neutrophil infiltration compared to control mice. These mice also exhibited increased lymphatic vessel density (73.0±3.9 vs 38.2±1.9, P<0.001) and lymphatic vessel size (1974.6±104.3 vs 1639.0±91.5, P<0.001) compared to control mice. Additionally, the expression of VEGFR-3 mRNA was significantly upregulated in VEGF-C156S mice compared to DSS-treated mice after induction of colitis (42.0±1.4 vs 3.5±0.4, P<0.001). Stimulation of lymphangiogenesis by VEGF-C during acute colitis promoted inflammatory lymphangiogenesis in the colon and aggravated intestinal inflammation. Inflammatory lymphangiogenesis may have pleiotropic effects at different stages of IBD.

Abstract P2-05-23: TWIST1 silences FOXA1 transcription to promote breast cancer progression

TWIST1 promotes epithelial-mesenchymal transition (EMT), invasion and metastasis of breast cancer cells, but the underlying mechanism is still not well understood. We generated mammary gland tumor specific Twist1 knock out mouse model and found that TWIST1 does not affect PyMT-induced mammary tumor initiation and growth but promotes tumor lung metastasis. We identified FOXA1 as a novel direct target of TWIST1 in both mouse and human breast cancer. We further found that TWIST1 inhibits FOXA1 expression through direct binding to its proximal promoter region and recruiting Mi2/nucleosome remodeling and deacetylase (Mi2/NuRD) transcriptional repressor complex. Moreover, TWIST1 also diminished transcriptional activator AP1 binding to FOXA1 promoter. TWIST1 mediated FOXA1 down-regulation is essential for promoting breast cancer migration, invasion and metastasis. FOXA1 significantly inhibits TWIST1 dependent cell migration and invasion capability of MCF7 cells through inhibiting integrin α5, β1 and MMP9 expression. Importantly, TWIST1high FOXA1low correlates with the poorest prognosis in breast cancer patients.

Citation Format: Xu Y, Feng Z, Xu Y, Mo Q, Qin L, Sun T, Wu H, Li Y, Liao L, Xu J. TWIST1 silences FOXA1 transcription to promote breast cancer progression. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-05-23.

Abstract P2-04-01: The role of Jmjd1a in mammary gland development and breast tumor growth

Histone modification alters chromatin architecture and thereby influences gene transcription. Histone methylation status is reversible and counter-regulated by methyltransferases and demethylases. Jmjd1a (also known as KDM3A, TSGA, JMJD1, JHDM2A and JHMD2A) is a histone demethylase. It belongs to JmjC domain-containing protein family and could specifically remove di- and mono- methyl residues from di or mono-methylated histone H3K9 (H3K9me2/me1). Recent studies showed that Jmjd1a plays an important role in embryonic stem cell self-renewal, spermatogenesis, regulation of metabolic gene expression and body weight, sex determination, tumor angiogenesis, and macrophage infiltration. However, its role in mammary gland (MG) development, breast carcinogenesis and breast cancer progression hasn't been systemically investigated. In this study, we found that Jmjd1a is expressed in mouse luminal epithelial cells. Genetic disruption of the Jmjd1a gene significantly slowed down MG development as indicated by retarded MG elongation and decreased ductal density in virgin mice observed at the ages of 4, 6 and 8 weeks. In agreement with the retarded MG development, the expression of Ki67 and cyclinD1 in epithelial cells of MGs from Jmjd1a knockout (KO) mice dramatically reduced compared with that from wild type (WT) mice. H3K9me1 and H3K9me2 levels in the epithelial cells of KO MGs are much higher than that in WT MGs. To assess the role of Jmjd1a in breast cancer progression, we crossbred Tg(Jmjd1a-/-) mice with MMTV-TVA(RCAS-PyMT) mice and obtained Tg(Jmjd1a-/-)×MMTV-TVA(RCAS-PyMT) mice. Infection of the TVA-expressing MG epithelial cells with the RCAS-PyMT virus induced mammary tumors in these mice and MMTV-TVA(RCAS-PyMT) control mice. We found that KO of Jmjd1a slightly accelerated mammary tumor initiation but significantly decreased tumor growth. Ki67 and cyclinD1 expression statistically reduced in KO tumors versus WT tumors. At the molecular level, Jmjd1a expression positively correlated with cyclin D1 expression in mammary epithelial cells and mammary tumors. Knockdown of Jmjd1a in MCF-7 cells significantly reduced cyclin D1 expression, while ectopic expression of Jmjd1a in MCF-7 cells increased cyclin D1 expression. ChIP assay revealed that Jmjd1a is associated with a promoter region of cyclin D1. Co-expression of c-Myc and Jmjd1a boosted the activity of the cyclin D1 reporter. In conclusion, our study indicated that Jmjd1a plays an important role in promoting mammary gland development and breast tumor growth by up-regulating cyclin D1 expression. Targeting Jmjd1a may inhibit breast cancer progression.

Citation Format: Qin L, Xu Y, Wu Y, Yu X, Toneff MJ, Liao L, Li Y, Xu J. The role of Jmjd1a in mammary gland development and breast tumor growth. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-04-01.

CAMK4 gene variation is associated with hypertension in a Uygur population

Considering that calcium/calmodulin-dependent kinase 4 (CAMK4) plays a pivotal role in blood pressure regulation, we investigated the association between a CAMK4 polymorphism (rs10491334) and hypertension in the Han, Kazak, and Uygur ethnic groups. We studied 1224 patients with hypertension and 967 normotensive controls classified into three ethnic groups (Han, Kazak, and Uygur). The rs10491334 polymorphism was genotyped using a TaqMan® 5'-nuclease assay. In the Uygur group, the T-allele frequency in patients with hypertension was twice that of the controls (12.5 vs 6.38%), and T-allele carriers had a significantly increased risk of hypertension compared with non-carriers (odds ratio = 2.200; 95% confidence interval = 1.473-3.285, P < 0.001). However, no significant correlation was found in the Han and Kazak groups. The T-allele of rs10491334 in CAMK4 was associated with hypertension in the Uygur group.

Successful infection control for a vancomycin-intermediate Staphylococcus aureus outbreak in an advanced emergency medical service centre

BACKGROUND

A vancomycin-intermediate Staphylococcus aureus (VISA) (vancomycin minimum inhibitory concentration: 4mg/L) outbreak occurred in an advanced emergency medical service centre [hereafter referred to as the intensive care unit (ICU)] between 2013 and 2014.

AIM

Our objective was to evaluate the infection control measures that were successful.

METHODS

Seventeen VISA strains were isolated from the sputum of 15 inpatients and the skin of two inpatients. Fourteen VISA strains were recognized as colonization. However, three VISA strains were isolated from the sputum of three inpatients with pneumonia. Environmental cultures were performed and VISA strains were detected in five of 65 sites. Pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) was performed on 21 VISA strains.

FINDINGS

Molecular typing including PFGE and MLST showed that the patterns of 19 VISA strains were identical and those of the other two VISA strains were possibly related. This meant that a horizontal transmission of VISA strains had occurred in the ICU. In August 2013, the infection control team began interventions. However, new inpatients with VISA strains continued to appear. Therefore, in October 2013, the ICU was partially closed in order to try to prevent further horizontal transmission, and existing inpatients with the VISA strain were isolated. Although new cases quickly dissipated after the partial closure, it took approximately five months to eradicate the VISA outbreak.

CONCLUSION

Our data suggest that despite the employment of various other infection control measures, partial closure of the ICU was essential in terminating this VISA outbreak.

Treadmill Running and Rutin Reverse High Fat Diet Induced Cognitive Impairment in Diet Induced Obese Mice

OBJECTIVES

To determine the effects of treadmill exercise training and rutin intervention independently and in combination on key molecules involved in Alzheimer's disease (AD) pathology and cognitive function in diet induced obese (DIO) mice.

METHODS

C57BL/6J mice were randomized into 5 groups: chow group, high fat diet group (HFD), HFD plus rutin intervention group (HR), HFD combined with treadmill running group (HE), HFD combined with treadmill running and rutin group (HRE). At the end of the intervention, Morris water maze test was conducted to assess hippocampal dependent, long term spatial learning and memory retention. Hippocampus and cortex were dissected and the protein expression of key molecules including insulin-degrading enzyme (IDE), Beta-secretase (BACE1), signal transducer and activator of transcription 3 (STAT3), cAMP-response element binding protein (CREB), post-synaptic density protein 95 (PSD-95) and synaptophysin were measured via western blotting.

RESULTS

Exercise and rutin enhances HFD induced cognitive deficits in DIO mice. In the hippocampus, although HFD has no effect on IDE, BACE1, phosphorylation (p)-STAT3 and p-CREB, HR and HE group have elevated protein expression of IDE; meanwhile, p-CREB was elevated in the HE and HRE group. In the cortex, HFD led to induction in BACE1 and reduction in p-STAT3 and PSD95. Rutin or exercise reversed BACE1, p-STAT3 and PSD95 to normal levels.

CONCLUSIONS

Treadmill running and rutin could improve HFD induced cognitive impairment, and p-STAT3, p-CREB, BACE1, IDE, and PSD95 are potential mediators involved in the protective effects of rutin or exercise against HFD induced cognitive dysfunction.

Association of NPRA and NPRC gene variants and hypertension in Mongolian population

NPRA and NPRC are candidate susceptibility genes for essential hypertension (EH) and play a key role in the regulation of plasma levels and biological effects of natriuretic peptides. The aims of the present study were to find new genetic markers in the NPRA and NPRC genes and to assess relationships between variants and EH. A total of 797 unrelated Mongolian herdsmen were enrolled, including 389 EH patients and 408 normotensive controls. Genotyping was performed using the polymerase chain reaction/ligase detection reaction assay. The distribution of the T-allele frequency of rs1847018 in NPRC differed significantly between hypertensive subjects and controls. There was an association between rs1847018 and EH in the additive model in NPRC (P < 0.05). There were no significant differences in the genotype and allele frequency distributions for any of the 3 single nucleotide polymorphisms in NPRA between EH and normotensive individuals. In NPRA, the frequency of haplotype TCA in the EH group was significantly lower than in controls, while the frequency of haplotype TCG was significantly higher in the EH group than in controls; Individuals who possessed the TCA haplotype had a significantly lower risk of EH, whereas the presence of haplotype TCG was significantly associated with a higher risk of EH. However, there was no significant difference between the EH group and controls in any of the 8 haplotypes in NPRC. Rs1847018 is a genetic marker of EH in NPRC, and the frequency of haplotype TCA and TCG in NPRA is associated with EH in the Mongolian population.

Association of regulator of G protein signaling (RGS5) gene variants and essential hypertension in Mongolian and Han populations

Genetic variants of the RGS5 gene are believed to be risk factors for hypertension and cardiovascular diseases. In this study, we investigated the association between RGS5 gene variants and hypertension in the Mongolian and Han populations. Peripheral blood was obtained from 429 unrelated Mongolian herdsmen and 416 Han farmers [including essential hypertension (EH) patients and controls]. Nine tagSNPs within the RGS5 genes were retrieved from HapMap, and the samples were individually genotyped using the polymerase chain reaction/ligase detection reaction assay. The distribution of the allele frequency of rs12035879 differed significantly between hypertensive subjects and controls in the Han population, while the distribution of the allele and genotype frequencies of rs16849802 differed significantly between hypertensive subjects and controls in the Mongolian population. We observed an association between rs16849802 and EH in the Mongolian population. The frequency of haplotype GAA was significantly higher in the EH group than in controls in the Mongolian population. However, the EH group and controls did not differ significantly in all 6 haplotypes in the Han population. The rs16849802 and haplotype GAA independently increased the risk of EH in Mongolian patients, and may be used as a risk factor for the prediction of high blood pressure.

Differential effects of low-magnitude high-frequency vibration on reloading hind-limb soleus and gastrocnemius medialis muscles in 28-day tail-suspended rats

OBJECTIVES

Low-magnitude high-frequency vibration (LMHFV) was reported beneficial to muscle contractile functions in clinical and preclinical studies. This study aims to investigate the effects of LMHFV on myofibers, myogenic cells and functional properties of disused soleus (Sol) and gastrocnemius medialis (GM) during reloading.

METHODS

Sprague Dawley rats were hind-limb unloaded for 28 days and assigned to reloading control (Ctrl) or LMHFV group (Vib). Sol and GM of both groups were harvested for fiber typing, proliferating myogenic cell counting and in vitro functional assessment.

RESULTS

Myogenic cells proliferation was promoted by LMHFV in both Sol and GM (p<0.001 and p<0.05 respectively). Force generating capacity was not much affected (Vib=Ctrl, p>0.05) but fast-fiber favorable changes in fiber type switching (more type IIA but lower type I in Vib; p<0.05 and 0.01 respectively) and fiber hypertrophy (type I, Vib<Ctrl; p<0.01) were observed mainly in GM.

CONCLUSION

LMHFV was not detrimental to reloading muscles but the outcomes were muscle dependent. The unique fiber type composition and anatomical differences between Sol and GM might render the differential muscle responses to LMHFV. Further investigations on myofibers type specific responses to different LMHFV regimes and myogenic cell interaction with associated myofiber were proposed.

miR-411 contributes the cell proliferation of lung cancer by targeting FOXO1

Lung cancer is the leading cause of cancer deaths worldwide; the study of microRNAs gives new hope for lung cancer treatment. miR-411 has been demonstrated to be an independent prognostic factor for lung adenocarcinoma, but the role and regulatory mechanism are largely unknown. In the present study, we found miR-411 was overexpressed in the lung cancer cells; overexpression of miR-411 promoted anchorage-dependent and anchorage-independent growths of lung cancer, while miR-411 knockdown reduced this effect. Further study showed forkhead box O1 (FOXO1) was a target of miR-411. Overexpression of miR-411 suppressed the expression of FOXO1; the effect of suppression was abrogated when the mutation occurred in the 3'UTR of FOXO1. Knockdown of FOXO1 in cells which miR-411 was inhibited recapitulated the phenotype of miR-411 overexpression. Taken together, our study revealed miR-411 promoted cell proliferation of lung cancer by targeting tumor suppressor gene FOXO1 and miR-411 might be a potential target for lung cancer therapy.

Effects and mechanism of lipoic acid on beta-amyloid-intoxicated C6 glioma cells

β-amyloid peptides (Aβs) can exert neurotoxic effects through induction of oxidative damage, whereas lipoic acid (LA), a powerful antioxidant, can alleviate oxidative damage. In this study, we explored the effect and mechanism of action of LA on beta-amyloid-intoxicated C6 glioma cells. Cells were randomly divided into three groups: control (vehicle), Aβ, and LA + Aβ. The LA + Aβ group was treated with LA for 2 h, then both the Aβ-only and the LA + Aβ groups were incubated with 25 μM Aβ for 24 h. Cell viability was measured by the MTT method. Mitochondrial reduced glutathione (GSH) and oxidized glutathione (GSSG) levels were detected by enzyme-linked immunosorbent assay (ELISA), and the GSH to GSSG ratio calculated. Real-time polymerase chain reaction and western blot analyses were used to detect MnSOD mRNA and protein, respectively. Aβ significantly inhibited C6 cell proliferation compared with the control group (P < 0.05). LA markedly increased cell viability compared with the Aβ group (P < 0.05). The increased GSSH and decreased GSH mitochondrial accumulation induced by Aβ was profoundly reversed by treatment with LA (P < 0.05). Aβ significantly reduced MnSOD expression compared to controls (P < 0.05), whereas LA pretreatment increased MnSOD expression compared with the Aβ-only group (P < 0.05); MnSOD protein levels showed similar patterns. These results suggest that LA might protect Aβ-intoxicated C6 glioma cells by alleviating oxidative damage, providing a new treatment strategy for neurodegenerative diseases.

Abnormal Bone Mechanical and Structural Properties in Adolescent Idiopathic Scoliosis: A Study with Finite Element Analysis and Structural Model Index

Previous studies found adolescent idiopathic scoliosis (AIS) is associated with low bone mineral density (BMD) and abnormal bone quality, whilst the association between AIS and their bone strength is unknown. From high-resolution peripheral quantitative computed tomography-generated images, bone mechanical properties can be evaluated with finite element analysis (FEA), and trabecular rod-plate configuration related to trabecular bone strength can be quantified by structure model index (SMI). This study aimed to compare trabecular configuration and bone mechanical properties between AIS and the controls. 95 AIS girls aged 12-14 years and 97 age- and gender-matched normal controls were recruited. Bilateral femoral necks and non-dominant distal radius were scanned by dual-energy X-ray absorptiometry for areal BMD and HR-pQCT for SMI and FEA, respectively. Subjects were further classified into osteopenic and non-osteopenic group based on their areal BMD. Bone mechanical properties (stiffness, failure load and apparent modulus) were calculated using FEA. Linear regression model was used for controlling age, physical activity and calcium intake. AIS was associated with lower failure load and apparent modulus after adjusting for age, whereas AIS was associated with lower apparent modulus after adjusting for all confounders. Osteopenic AIS was associated with more rod-like trabeculae when compared with non-osteopenic AIS, whereas no difference was detected between osteopenic and non-osteopenic controls. This might be the result of abnormal regulation and modulation of bone metabolism and bone modelling and remodelling in AIS which will warrant future studies with a longitudinal design to determine the significance of micro-architectural abnormalities in AIS.

Age-related differences in volumetric bone mineral density, microarchitecture, and bone strength of distal radius and tibia in Chinese women: a high-resolution pQCT reference database study

In a cohort of 393 Chinese women, by using high-resolution peripheral quantitative computed tomography (HR-pQCT), we found that significant cortical bone loss occurred after midlife. Prominent increase in cortical porosity began at the fifth decade but reached a plateau before the sixth decade. Trabecular bone loss was already evident in young adulthood and continued throughout life.

INTRODUCTION

This study aimed to investigate age-related differences in volumetric bone mineral density (vBMD), microarchitecture, and estimated bone strength at peripheral skeleton in Chinese female population.

METHODS

In a cross-sectional cohort of 393 Chinese women aged 20-90 years, we obtained vBMD, microarchtecture, and micro-finite element-derived bone strength at distal radius and tibia using HR-pQCT.

RESULTS

The largest predictive age-related difference was found for cortical porosity (Ct.Po) which showed over four-fold and two-fold differences at distal radius and tibia, respectively, over the adulthood. At both sites, cortical bone area, vBMD, and thickness showed significant quadratic association with age with significant decrease beginning after midlife. Change of Ct.Po became more prominent between age of 50 and 57 (0.26 %/year at distal radius, 0.54 %/year at distal tibia, both p ≤ 0.001) but thereafter, reached a plateau (0.015 and 0.028 %/year, both p > 0.05). In contrast, trabecular vBMD and microarchitecture showed linear association with age with significant deterioration observed throughout adulthood. Estimated age of peak was around age of 20 for trabecular vBMD and microarchitecture and Ct.Po and age of 40 for cortical vBMD and microarchitecture. Estimated stiffness and failure load peaked at mid-30s at the distal radius and at age 20 at distal tibia.

CONCLUSIONS

Age-related differences in vBMD and microarchitecture in Chinese women differed by bone compartments. Significant cortical bone loss occurred after midlife. Prominent increase in Ct.Po began at the fifth decade but appeared to be arrested before the sixth decade. Loss of trabecular bone was already evident in young adulthood and continued throughout life.