miRNAs as potential therapeutic targets and diagnostic biomarkers for cardiovascular disease with a particular focus on WO2010091204

INTRODUCTION

A number of miRNAs have been reported to be critically involved in the regulation of cardiovascular disease (CVDs). Therefore, the development of potent analogues/inhibitors for miRNAs have thus become a key focus in the present drug discovery. In this review, we discuss the basic research and clinical use of miRNAs as the early diagnosis and therapeutic targets for CVD. We have also focused on the efficiency of therapeutically targeting miR-499, which is considered as one of the most promising molecules for treating CVDs. Areas covered: In this review, we have discussed the patents and patent applications related to miRNAs detected in CVD patients published in recent years. This review also covers the expression pattern of miR-499, as well as it highlights functions of its inhibitors in CVD. We used Google and Pubmed search engines to find relevant patents. Expert opinion: Although a massive number of miRNAs are patented as CVD biomarkers, further work is absolutely required to evaluate the reliable diagnostic values and therapeutic potential of these candidates. Overall, targeting miRNAs is definitely a promising strategy to be investigated for diagnosis and treatment of CVDs in future, however, the delivery system and off-targets effects are still a difficult challenge need to be elucidated.

How well are we managing fragility hip fractures? A narrative report on the review with the attempt to setup a Fragility Fracture Registry in Hong Kong

INTRODUCTION

In setting up a disease registry for fragility fractures in Hong Kong, we conducted a retrospective systematic study on the management of fragility hip fractures. Patient outcomes were compared with the standards from our orthopaedic working group and those from the British Orthopaedic Association that runs a mature fracture registry in the United Kingdom.

METHODS

Clinical data on fragility hip fracture patients admitted to six acute major hospitals in Hong Kong in 2012 were captured. These included demographics, pre- and post-operative assessments, discharge details, complications, and 1-year follow-up information. Analysis was performed according to the local standards with reference to those from the British Orthopaedic Association.

RESULTS

Overall, 91.0% of patients received orthopaedic care within 4 hours of admission and 60.5% received surgery within 48 hours. Preoperative geri-orthopaedic co-management was received by 3.5% of patients and was one of the reasons for the delayed surgery in 22% of patients. Only 22.9% were discharged with medication that would promote bone health. Institutionalisation on discharge significantly increased by 16.2% (P<0.001). Only 35.1% of patients attended out-patient follow-up 1 year following fracture, and mobility had deteriorated in 69.9% compared with the premorbid state. Death occurred in 17.3% of patients within a year of surgery compared with 1.6% mortality rate in a Hong Kong age-matched population.

CONCLUSIONS

The efficiency and quality of acute care for fragility hip fracture patients was documented. Regular geri-orthopaedic co-management can enhance acute care. Much effort is needed to improve functional recovery, prescription of bone health medications, attendance for follow-up, and to decrease institutionalisation. A Fracture Liaison Service is vital to improve long-term care and prevent secondary fractures.

Molecular cloning and analysis of a receptor-like promoter of Gbvdr3 gene in sea island cotton

Verticillium wilt caused by soil borne fungus Verticillium dahliae could significantly reduce cotton yield. The Ve1 homologous gene Gbvdr3 is resistant to Verticillium wilt. In order to understand of the function of the promoter Gbvdr3 in Gossypium barbadense, the promoter region of the receptor-like gene Gbvdr3 was obtained by genome walking, and the cis-element in the promoter was identified using the PLACE software in this study. The sequence analysis showed that the promoter contained elements related to stress resistance and light regulation. The cloned promoter was fused to the GUS reporter gene and transformed into Arabidopsis. GUS expression was specifically detected in roots, flowers, and seeds, suggesting that the expression of Gbvdr3 is tissue-specific. Separation and characterization analysis of the promoter of Gbvdr3 provides a platform for further research and application of this gene. Thorough understanding of the function of the Gbvdr3 promoter is important for better understanding of Gbvdr3 function. These results indicated that the promoter of Gbvdr3 was a tissue-specific promoter.

Mid-infrared Photoconductive Response in AlGaN/GaN Step Quantum Wells

AlGaN/GaN quantum structure is an excellent candidate for high speed infrared detectors based on intersubband transitions. However, fabrication of AlGaN/GaN quantum well infrared detectors suffers from polarization-induced internal electric field, which greatly limits the carrier vertical transport. In this article, a step quantum well is proposed to attempt solving this problem, in which a novel spacer barrier layer is used to balance the internal electric field. As a result, a nearly flat band potential profile is obtained in the step barrier layers of the AlGaN/GaN step quantum wells and a bound-to-quasi-continuum (B-to-QC) type intersubband prototype device with detectable photocurrent at atmosphere window (3-5 μm) is achieved in such nitride semiconductors.

FOXC2 promotes colorectal cancer metastasis by directly targeting MET

Metastasis is the major cause of death in colorectal cancer (CRC). Although multiple genes have been identified to be responsible for the development of CRC, the molecular changes that enable CRC cells to undergo early local invasion and to form distant metastatic colonies still remain largely unknown. Herein, we investigated the role of Forkhead box protein C2 (FOXC2) and explored the underlying mechanisms in invasion and metastasis of CRC. We show that both high FOXC2 expression and nuclear localization of FOXC2 are significantly correlated with advanced TNM (T=primary tumor; N=regional lymph nodes; M=distant metastasis) stages. FOXC2 enhanced the invasive abilities of CRC cells in vitro and promoted local invasion and distant metastasis in an orthotopic mouse metastatic model of CRC. Microarray analysis revealed that overexpression of FOXC2 increased the proto-oncogene MET tyrosine kinase expression and activated the hepatocyte growth factor (HGF)-MET signaling pathway. Furthermore, luciferase reporter assays and chromatin immunoprecipitation assays revealed that FOXC2 directly associated with MET promoter to increase the transcriptional activity of MET. Inhibition of MET attenuates the invasive phenotype and metastatic potential of FOXC2-overexpressing CRC cells, indicating that MET is a major mediator of FOXC2-promoted metastasis. In addition, FOXC2 expression was positively correlated with MET expression in CRC tissue samples. Our findings suggest that FOXC2 has a crucial role in CRC metastasis by regulating HGF-MET signaling via inducing MET expression, highlighting FOXC2 as a potential therapeutic target for preventing or reducing metastasis in CRC.

Neonatal ketamine exposure causes impairment of long-term synaptic plasticity in the anterior cingulate cortex of rats

Ketamine, a dissociative anesthetic most commonly used in many pediatric procedures, has been reported in many animal studies to cause widespread neuroapoptosis in the neonatal brain after exposure in high doses and/or for a prolonged period. This neurodegenerative change occurs most severely in the forebrain including the anterior cingulate cortex (ACC) that is an important brain structure for mediating a variety of cognitive functions. However, it is still unknown whether such apoptotic neurodegeneration early in life would subsequently impair the synaptic plasticity of the ACC later in life. In this study, we performed whole-cell patch-clamp recordings from the ACC brain slices of young adult rats to examine any alterations in long-term synaptic plasticity caused by neonatal ketamine exposure. Ketamine was administered at postnatal day 4-7 (subcutaneous injections, 20mg/kg given six times, once every 2h). At 3-4weeks of age, long-term potentiation (LTP) was induced and recorded by monitoring excitatory postsynaptic currents from ACC slices. We found that the induction of LTP in the ACC was significantly reduced when compared to the control group. The LTP impairment was accompanied by an increase in the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor-mediated excitatory synaptic transmission and a decrease in GABA inhibitory synaptic transmission in neurons of the ACC. Thus, our present findings show that neonatal ketamine exposure causes a significant LTP impairment in the ACC. We suggest that the imbalanced synaptic transmission is likely to contribute to ketamine-induced LTP impairment in the ACC.

Revealing of the transition from n- to p-type conduction of InN:Mg by photoconductivity effect measurement

We report evidence of the transition from n- to p-type conduction of InN with increasing Mg dopant concentration by using photoconductivity (PC) measurement at room temperature. This transition is depicted as a conversion from negative to positive PC under above-bandgap optical excitation. The n- to p-type transition in InN:Mg is further confirmed by thermopower measurements. PC detection method is a bulk effect since the optical absorption of the surface electron accumulation is negligibly low due to its rather small thickness, and thus shows advantage to detect p-type conduction. This technique is certainly helpful to study p-type doping of InN, which is still a subject of discussions.

Identification of Tumorigenesis from the Specific Coupling of Cyclooxygenase-2 with Microsomal Prostaglandin E2 Synthase-1 in vivo

A newly created hybrid enzyme (COX-2-10aa-mPGES-1), which mimics the specific biosynthesis of the inflammatory PGE2 through COX-2's coupling to mPGES-1, was stably expressed in HEK293 cells. The stable cell line, which consistently expresses the superior triple catalytic (Trip-Cat) activities from COX-2 and mPGES-1, was able to directly convert arachidonic acid into the pathogenic PGE2 and distinguish it from other PGE2 synthesizing pathways, as confirmed by enzyme immunoassay, LC/MS analysis and a specific [14C]-AA (arachidonic acid) metabolite analysis approach. A competitive assay confirmed that the endogenous cPGES and mPGES-2 in the HEK293 cells had little involvement in the presence of the expressed COX-2-10aa-mPGES-1 for the synthesis of pathogenic PGE2. Furthermore, subcutaneous injection of the stable cell lines into nu/nu mice revealed 100% (10 out 10) occurrence of tumor mass formation beginning on Day 7 and a continuous progression of the masses to the maximal size which required sacrificing the mice. In contrast, only 10% occurrence of tumor masses, though smaller and with slower growth rates, were observed for the group of vector-transfected HEK293 control cells expressing only endogenous cPGES and/or mPGES-2. The PGE2 produced from multiple pathways by the HEK293 cells co-expressing the individual wild type COX-2 and mPGES-1, and in the presence of endogenous cPGES and mPGES-2, showed also a significantly increased tumor occurrence rate to 30%, which confirmed that the sole coupling of COX-2 to mPGES-1 is a powerful tumor-advancing factor. This result implies that the engineered COX-2-10aa-mPGES-1 could be a promising molecule as a drug developing target against the pathway of COX-2 coupled to mPGES-1 to treat inflammatory diseases and cancers.

Induced maturation of hepatic progenitor cells in vitro

Hepatic progenitor cells (HPCs) are a potential cell source for liver cell transplantation but do not function like mature liver cells. We sought an effective and reliable method to induce HPC maturation. An immortalized HP14.5 albumin promoter-driven Gaussian luciferase (ALB-GLuc) cell line was established from HPCs isolated from fetal mouse liver of post coitus day 14.5 mice to investigate the effect of induction factors on ALB promoter. HP14.5 parental cells were cultured in DMEM with different combinations of 2% horse serum (HS), 0.1 µM dexamethasone (DEX), 10 ng/mL hepatic growth factor (HGF), and/or 20 ng/mL fibroblast growth factor 4 (FGF4). Trypan blue and crystal violet staining were used to assess cell proliferation with different induction conditions. Expression of hepatic markers was measured by semi-quantitative RT-PCR, Western blot, and immunofluorescence. Glycogen storage and metabolism were detected by periodic acid-Schiff and indocyanine green (ICG) staining. GLuc activity indicated ALB expression. The combination of 2% HS+0.1 µM Dex+10 ng/mL HGF+20 ng/mL FGF4 induced the highest ALB-GLuc activity. Cell proliferation decreased in 2% HS but increased by adding FGF4. Upon induction, and consistent with hepatocyte development, DLK, AFP, and CK19 expression decreased, while ALB, CK18, and UGT1A expression increased. The maturity markers tyrosine aminotransferase and apolipoprotein B were detected at days 3 and 6 post-induction, respectively. ICG uptake and glycogen synthesis were detectable at day 6 and increased over time. Therefore, we demonstrated that HPCs were induced to differentiate into functional mature hepatocytes in vitro, suggesting that factor-treated HPCs may be further explored as a means of liver cell transplantation.

Growth factor receptor-bound protein 10-mediated negative regulation of the insulin-like growth factor-1 receptor-activated signalling pathway results in cognitive disorder in diabetic rats

Growth factor receptor-bound protein 10 (Grb10) is a Src homology 2 domain-containing protein and one of the binding partners for several transmembrane tyrosine kinase receptors, including insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1-R). The hippocampus, which is critical for cognitive functions, is one of the main distribution areas of Grb10 in the central nervous system. In recent years, diabetic encephalopathy has been defined as a third type of diabetes and the IGF1-IR pathway was shown to be critical for the neuropathogenic process of cognitive disorder in diabetes. However, the role of endogenous Grb10 in regulating the IGF1-IR pathway and neurobehavioural changes is not explicit. The present study aimed to determine the in vivo function of endogenous Grb10 in diabetic encephalopathy and the underlying mechanisms. Using stereotaxic surgical techniques and lentiviral vectors expressing specific short hairpin RNA, we could steadily knockdown Grb10 expression in the hippocampus. More importantly, we demonstrated that hippocampus-specific modulation of Grb10 protein levels led to a prominent remission of cognitive disorder, including improvements in both ultrastructural pathology and abnormal neurobehavioural changes. Our findings indicate that endogenous overexpression of Grb10 functions as a suppressor of the IGF1-IR pathway, which may represent an important mechanism for regulating cognitive disorder in diabetes.

Rheological Properties and Morphological Structure of Blended and Filled Nylon-6

Rheological properties and morphological structure of PA 6/NBR and PA 6/EVA blends with and without CaCO3 fillers are studied. It is found that viscosities of samples investigated can be described approximately by the power law. The rheological behaviour of PA 6/NBR blends slightly deviates from the so-called logarithmic additivity law of the relation between viscosity and composition. The viscosity-composition curve of PA 6/EVA blends shows a positive deviation at the range of low shear rate and changes to the manner of negative deviation after the shear rate is greater than a certaine value. All the samples fabricated in the experiment perform very satisfactory in their processing. An unique morphological structure is found for them, which may be presented by the model of “sea and island”.