Identification of LRP16 as a negative regulator of insulin action and adipogenesis in 3T3-L1 adipocytes

Leukemia related protein 16 (LRP16) was first cloned from acute myeloid leukemia cells in our laboratory. In the present study, we sought to investigate the role of LRP16 in insulin action and sensitivity, using LRP16-depleted and -overexpressing 3T3-L1 cells. LRP16 silencing resulted in a reduction of the expression and secretion of tumor necrosis factor-alpha (TNF-α) and a concomitant increase in the expression of peroxisome proliferator-activated receptor-gamma (PPAR-γ). Moreover, LRP16 depletion promoted insulin-induced glucose uptake and adipocyte differentiation of 3T3-L1 cells. In contrast, LRP16 overexpression increased TNF-α secretion, suppressed glucose uptake, and attenuated 3T3-L1 cell differentiation. The phosphorylation levels of insulin receptor substrate 1 (IRS-1), phosphatidylinositide 3-kinase (PI3-K), and Akt were increased in LRP16-deficient 3T3-L1 cells, and conversely, diminished in LRP16-overexpressing 3T3-L1 cells, when compared to the corresponding control cells. Additionally, LRP16 overexpression raised the phosphorylation level of mammalian target of rapamycin (mTOR). The pretreatment with rapamycin, a specific inhibitor of mTOR, prevented the TNF-α elevation and PPAR-γ reduction and restored the phosphorylation of IRS-1, PI3-K, and Akt in LRP16-overexpressing cells. Our data collectively indicate that LRP16 acts as a negative regulator of insulin action and adipogenesis in 3T3-L1 adipocytes, which involves the activation of the mTOR signaling pathway.

Phenotype characterization and sequence analysis of BMP2 and BMP4 variants in two Mexican families with oligodontia

Both BMP2 and BMP4 are involved in tooth development. We examined phenotypes and BMP2 and BMP4 gene variations in two Mexican oligodontia families. Physical and oral examinations and panoramic radiographs were performed on affected and unaffected members in these two families. The affected members lacked six or more teeth. DNA sequencing was performed to detect BMP2 and BMP4 gene variations. Three single nucleotide polymorphisms (SNPs) in BMP2 and BMP4 genes were identified in the two families, including one synonymous and two missense SNPs: BMP2 c261A>G, pS87S, BMP2 c570A>T, pR190S, and BMP4 c455T>C, pV152A. Among the six affected patients, 67% carried "GG" or "AG" genotype in BMP2 c261A>G and four were "TT" or "AT" genotype in BMP2 c570A>T (pR190S). Polymorphism of BMP4 c455T>C resulted in amino acid changes of Val/Ala (pV152A). BMP2 c261A>G and BMP4 c455T>C affect mRNA stability. This was the first time that BMP2 and BMP4 SNPs were observed in Mexican oligodontia families.

The Adipose Tissue Endocrine Mechanism of the Prophylactic Protective Effect of Pioglitazone in High-Fat Diet-Induced Insulin Resistance

OBJECTIVE: To explore the adipose tissue endocrine mechanism of pioglitazone and its possible prophylactic role in insulin resistance. METHODS: Male Wistar rats were randomized to receive a normal diet (N group), a high-fat insulin resistance-inducing diet (IR group), or a high-fat diet plus treatment with pioglitazone (P group). Glucose tolerance and insulin resistance were tested at weeks 10 and 11 after starting the diet and, at week 12, adipose, liver and skeletal muscle tissue samples were taken. HepG2 cells were cultured with palmitic acid (PA), pioglitazone and PA plus pioglitazone, and RNA interference was used to downregulate adiponectin receptor (AdipoR) 2 in these cells. The mRNA and protein levels of adipokines (resistin and adiponectin), AdipoR1 and 2 and uptake of [3H]-labelled glucose were measured in the HepG2 cells. RESULTS: Resistin and adiponectin in adipose tissue and AdipoR2 in liver tissue were significantly decreased in the IR group compared with the N group. Adiponectin and AdipoR2 were significantly increased and insulin resistance significantly decreased in the P group versus the IR group. In HepG2 cells, AdipoR2 levels and glucose uptake decreased significantly when PA was ≥ 200 μM, but were elevated by pioglitazone. Small interfering RNA-AdipoR2 confirmed glucose uptake in liver was regulated by AdipoR2. CONCLUSIONS: Pioglitazone prevented insulin resistance in rats fed a high-fat diet. Liver AdipoR2-mediated glucose uptake is important in the prophylactic effect of pioglitazone on insulin resistance.

'Green'-synthesized near-infrared PbS quantum dots with silica-PEG dual-layer coating: ultrastable and biocompatible optical probes for in vivo animal imaging

In this paper, PbS semiconductor quantum dots (QDs) with near-infrared (NIR) photoluminescence were synthesized in oleic acid and paraffin liquid mixture by using an easily handled and 'green' approach. Surface functionalization of the QDs was accomplished with a silica and polyethylene glycol (PEG) phospholipid dual-layer coating and the excellent chemical stability of the nanoparticles is demonstrated. We then successfully applied the ultrastable PbS QDs to in vivo sentinel lymph node (SLN) mapping of mice. Histological analyses were also carried out to ensure that the intravenously injected nanoparticles did not produce any toxicity to the organism of mice. These experimental results suggested that our ultrastable NIR PbS QDs can serve as biocompatible and efficient probes for in vivo optical bioimaging and has great potentials for disease diagnosis and clinical therapies in the future.

APC and Smad7 link TGFβ type I receptors to the microtubule system to promote cell migration

Cell migration occurs by activation of complex regulatory pathways that are spatially and temporally integrated in response to extracellular cues. Binding of adenomatous polyposis coli (APC) to the microtubule plus ends in polarized cells is regulated by glycogen synthase kinase 3β (GSK-3β). This event is crucial for establishment of cell polarity during directional migration. However, the role of APC for cellular extension in response to extracellular signals is less clear. Smad7 is a direct target gene for transforming growth factor-β (TGFβ) and is known to inhibit various TGFβ-induced responses. Here we report a new function for Smad7. We show that Smad7 and p38 mitogen-activated protein kinase together regulate the expression of APC and cell migration in prostate cancer cells in response to TGFβ stimulation. In addition, Smad7 forms a complex with APC and acts as an adaptor protein for p38 and GSK-3β kinases to facilitate local TGFβ/p38-dependent inactivation of GSK-3β, accumulation of β-catenin, and recruitment of APC to the microtubule plus end in the leading edge of migrating prostate cancer cells. Moreover, the Smad7-APC complex links the TGFβ type I receptor to the microtubule system to regulate directed cellular extension and migratory responses evoked by TGFβ.

Altered mTOR signaling and enhanced CYFIP2 expression levels in subjects with fragile X syndrome

Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and autism. The protein (FMRP) encoded by the fragile X mental retardation gene (FMR1), is an RNA-binding protein linked to translational control. Recently, in the Fmr1 knockout mouse model of FXS, dysregulated translation initiation signaling was observed. To investigate whether an altered signaling was also a feature of subjects with FXS compared to typical developing controls, we isolated total RNA and translational control proteins from lymphocytes of subjects from both groups (38 FXS and 14 TD). Although we did not observe any difference in the expression level of messenger RNAs (mRNAs) for translational initiation control proteins isolated from participant with FXS, we found increased phosphorylation of the mammalian target of rapamycin (mTOR) substrate, p70 ribosomal subunit 6 kinase1 (S6K1) and of the mTOR regulator, the serine/threonine protein kinase (Akt), in their protein lysates. In addition, we observed increased phosphorylation of the cap binding protein eukaryotic initiation factor 4E (eIF4E) suggesting that protein synthesis is upregulated in FXS. Similar to the findings in lymphocytes, we observed increased phosphorylation of S6K1 in brain tissue from patients with FXS (n = 4) compared to normal age-matched controls (n = 4). Finally, we detected increased expression of the cytoplasmic FMR1-interacting protein 2 (CYFIP2), a known FMRP interactor. This data verify and extend previous findings using lymphocytes for studies of neuropsychiatric disorders and provide evidence that misregulation of mTOR signaling observed in the FXS mouse model also occurs in human FXS and may provide useful biomarkers for designing targeted treatments in FXS.

TRAF6 ubiquitinates TGFβ type I receptor to promote its cleavage and nuclear translocation in cancer

Transforming growth factor β (TGFβ) is a pluripotent cytokine promoting epithelial cell plasticity during morphogenesis and tumour progression. TGFβ binding to type II and type I serine/threonine kinase receptors (TβRII and TβRI) causes activation of different intracellular signaling pathways. TβRI is associated with the ubiquitin ligase tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6). Here we show that TGFβ, via TRAF6, causes Lys63-linked polyubiquitination of TβRI, promoting cleavage of TβRI by TNF-alpha converting enzyme (TACE), in a PKCζ-dependent manner. The liberated intracellular domain (ICD) of TβRI associates with the transcriptional regulator p300 to activate genes involved in tumour cell invasiveness, such as Snail and MMP2. Moreover, TGFβ-induced invasion of cancer cells is TACE- and PKCζ- dependent and the TβRI ICD is localized in the nuclei of different kinds of tumour cells in tissue sections. Thus, our data reveal a specific role for TβRI in TGFβ mediated tumour invasion.

TGFβ can function as both a tumour suppressor and tumour promoter under different cellular contexts. Here, the cleavage product of the TGFβ type I receptor is shown to be generated in a TGFβ-dependent manner, and can induce the expression of genes involved in tumour cell invasion.

Non-Smad signaling pathways

Transforming growth factor-beta (TGFβ) is a key regulator of cell fate during embryogenesis and has also emerged as a potent driver of the epithelial-mesenchymal transition during tumor progression. TGFβ signals are transduced by transmembrane type I and type II serine/threonine kinase receptors (TβRI and TβRII, respectively). The activated TβR complex phosphorylates Smad2 and Smad3, converting them into transcriptional regulators that complex with Smad4. TGFβ also uses non-Smad signaling pathways such as the p38 and Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) pathways to convey its signals. Ubiquitin ligase tumor necrosis factor (TNF)-receptor-associated factor 6 (TRAF6) and TGFβ-associated kinase 1 (TAK1) have recently been shown to be crucial for the activation of the p38 and JNK MAPK pathways. Other TGFβ-induced non-Smad signaling pathways include the phosphoinositide 3-kinase-Akt-mTOR pathway, the small GTPases Rho, Rac, and Cdc42, and the Ras-Erk-MAPK pathway. Signals induced by TGFβ are tightly regulated and specified by post-translational modifications of the signaling components, since they dictate the subcellular localization, activity, and duration of the signal. In this review, we discuss recent findings in the field of TGFβ-induced responses by non-Smad signaling pathways.

O45-regulation of osteoblast differentiation and ECM remodeling by Bmp2/4 in vitro

Both of bone morphogenetic proteins 2 and 4 (Bmp2 and Bmp4) are two closely related members of the transforming growth factor beta superfamily and play diverse roles in normal and pathological processes. However, detail understandings of mechanisms through which Bmp2 and Bmp4 exert their effects remain elusive due to their functional compensations each other. To study roles of Bmp2/Bmp4 in osteoblast differentiation and extracellular matrix (ECM) remodeling, calvarial osteoblasts from Bmp2/4 conditional mice with Cre recombinase recognition site (loxP) were isolated and transfected with simian virus 40 large T antigen to generate immortalized BMP2C/C4C/C (iBMP2 C/C/4C/C) osteoblast lines. The BMP2/4 genes in the iBMP2 C/C/4C/C cells were double knocked out by Ad-Cre recombinase infection. Differentiation and mineralization of iBMP2C/C/4C/C knock-out (iBmp2C/C/4C/C KO) cells were detected by alkaline phosphatase (ALP) and alizarin (ALZ) red S staining analyses. ECM remodeling was also observed in fluorescent microscope. Cell differentiation was dramatically decreased in the iBMP2C/C/4C/C KO cells compared to that of the iBMP2C/C/4C/C osteoblasts. Mineralization was also reduced in these KO cells by ALZ staining. Furthermore, Bmp2/4 double knock-out cells have major defects in remodeling the ECM as reflected by changes in collagen type I processing. Here we for the first time demonstrate the establishment of iBmp2C/C/4C/C KO osteoblasts. Cell differentiation and mineralization in the iBmp2C/C/4C/C KO cells were decreased. Furthermore, ECM processing in these KO cells was impaired. This indicates that BMP2/4 play important roles in osteoblast differentiation and ECM remodeling.

Structural features of the 5’ flanking region of the Yak (Bos grunniens) growth hormone receptor (GHR) gene (Brief Report)

Abstract. Yak (Bos grunniens) is a species of the Bovidae family living on the Qinghai-Tibetan Plateau and its adjacent territories at altitudes from 2 000–5 000 m (LUO et al. 2005, MA et al. 2009). As a multi-purpose domestic animal, yaks are indispensable to the local animal husbandry development because it can provide life necessities such as meat, milk, fur, velour manufacturing, transportation and manure for fuel to the local herdsmen. There are twelve yak populations numbered around 13.3 million in China and the Bazhou yak is one of Chinese yak populations (WIENER et al. 2003). The Growth Hormone Receptor (GHR) gene was identified as a candidate gene affecting key quantitative traits, like growth, milk yield and composition in livestock. At present, only investigations were carried out on the genetic variation in Exon-8, Intron-8 and Exon-10 of the yak GHR gene (VARVIO et al. 2008), no other information on the yak GHR gene is available. The purposes of this study were to – analyze the structural features of the 5’ flanking region of the yak GHR gene – compare the 5’ flanking region of yak GHR gene with that of other species of the Bovidae family and – construct the phylogenetic tree to indicate the evolutionary relationship among them.

Clinical involvement in daughters of men with fragile X-associated tremor ataxia syndrome

Women with the fragile X mental retardation 1 (FMR1) premutation often have concerns about neurological and medical problems, as they become older and if their fathers experience fragile X-associated tremor/ataxia syndrome (FXTAS). We therefore determined the prevalence of these problems in 110 daughters of men with FXTAS [mean age of 44.8 years (SD 8.2)]. We compared them with 43 female controls with normal FMR1 alleles [mean age of 43.8 years (SD 8.1)] and 36 premutation carrier daughters of parents with the premutation, but without FXTAS [mean age of 43.5 years (SD 7.7)]. Overall, daughters of men with FXTAS have a higher prevalence of neurological symptoms including tremor, balance problems, memory problems, and dizziness, menopausal symptoms, and psychiatric involvement including sleep problems and anxiety when compared with non-carrier female controls. Reported balance problems and menopausal symptoms were significantly higher in daughters of men with FXTAS than in carrier daughters of parents without FXTAS, suggesting the potential influence of background gene effects. Therefore, neurological, psychological and gynecological surveillance should be warranted to better provide appropriate counseling, management and care for daughters of men with FXTAS. Biological markers of additional gene effects that predispose individuals with the premutation to FXTAS need to be developed.

Practical guidance on intensification of insulin therapy with BIAsp 30: a consensus statement

BACKGROUND

Basal insulin and premix insulin are commonly prescribed first-line insulin therapies for patients failing to maintain glycaemic control on oral therapy. When control on these insulins starts to drift, premix analogues, such as biphasic insulin aspart 30/70 (BIAsp 30), are a simple and effective tool for intensification as they can be injected up to three-times daily (TID). However, at present, international recommendations for intensification of insulin therapy using premix analogues are limited and specific guidance on dosing is not available for many scenarios.

METHODS

In October 2008, an international expert panel met to review the current guidelines for insulin intensification with BIAsp 30 in patients with type 2 diabetes, with the aim of developing practical guidance for general and specialist practitioners.

RESULTS

Simple treatment algorithms have been developed for (i) patients on basal insulin (human or analogue) once daily or twice daily (BID) who need intensification to BIAsp 30 BID, and (ii) patients on BIAsp 30 once daily or BID who can be intensified to BIAsp 30 BID or TID. As well as these algorithms, specific guidance has been provided on dose transfer (from basal insulin to BIAsp 30), dose split (when intensifying from once daily to BID), and combination oral therapies. In addition, a guide to dose titration is included.

CONCLUSIONS

The guidelines presented here should enable general or specialist practitioners to use BIAsp 30 to intensify the insulin therapy of patients failing on basal insulin or BIAsp 30 once or twice daily.

Filterscopes: spectral line monitors for long-pulse plasma devices

A photomultiplier (PMT)-based diagnostic system for monitoring spectral lines along multiple viewchords, named the "Filterscope" [R. J. Colchin et al., Rev. Sci. Instrum. 74, 2068 (2003)], is currently in use at the DIII-D, NSTX, and CDX-U fusion plasma devices in the US, and has been installed at the KSTAR device in Korea. This diagnostic has recently been upgraded for application to long-pulse devices, such as KSTAR, EAST in China, and the future ITER in France. A new data acquisition system, employing the PXI instrumentation platform with an embedded Windows microprocessor controller, can simultaneously record up to 72 channels at 100 kHz sampling rates for plasma periods lasting up to 20 min. Based on the average signal level during an adjustable time interval (100 ms in the present DIII-D implementation), the controller digitally adjusts PMT dynode voltage throughout the course of a discharge, thereby maintaining the output signals at a level where they are neither saturated nor dominated by digitizer noise. The new system's ability to accommodate large variations in source strength, discharge to discharge and within a single discharge, has proved particularly valuable during DIII-D operations, since changes between top, bottom, and double-null divertor magnetic configurations lead to large temporal variations in signal brightness.

Identification of estrogenically synthesized LRP16 as an ERα coactivator and its role in ERα-positive breast cancer

10676

Background: Aberrant ERα activity is linked to genesis and malignant progression of breast cancer through direct target gene activation or repression. A complex network of coregulatory proteins is largely believed to determine the transcriptional activity of ERα. LRP16 was identified previously to be an estrogen (E2) responsive gene, but its function involving in conferring estrogen signalling pathway is not clear. Methods: Endogenous LRP16 expression in MCF-7 cells was stably suppressed by retrovirus-mediated small interference RNA (siRNA). The effects of LRP16 expression on E2-stimulated growth and invasive ability of MCF-7 cells were determined in vitro and in vivo assays. The effects of LRP16 expression on ERα transactivation were determined by luciferase assays. The interaction of LRP16 and ERα was examined by GST pull-down and coimmunopricipitation (CoIP) assays. Northern blot and Western blot were used to detect the mRNA and protein levels of ER target genes in LRP16-inhibited MCF-7 cells. The LRP16 expression levels in primary breast cancer were detected by Northern blot. Results: Fristly, LRP16 expression was characterized to be dependent on estrogen activities. Then, LRP16 was identified to be an estrogen-independent ERα cofactor in ER-positive breast cancer cells and demonstrate that LRP16 is an essential coactivator to ERα-mediated transactivation in an estrogen-dependent manner. Suppression of LRP16 expression in ER-positive breast cancer cells specifically inhibits the transcription of ER upregulated genes, results in the increase of E-cadherin expression through ER mediation. In vitro and in vivo data demonstrate that suppression of LRP16 inhibits the ability of estrogen-stimulated proliferation and invasiveness of ER-positive breast cancer cells. The pathological and clinical characteristics of human breast cancer includining ER/PR-positiveness, tumor diameter and the involvement of axillary lymphoid nodes were tightly linked with the LRP16 gene expression level. Conclusions: These results establish a mechanistic link between estrogen receptor status, its coactivator LRP16, and progression of ER-positive breast cancers, and may provide a novel antiestrogenic target for the therapy of ER positive breast cancer.

No significant financial relationships to disclose.

Development of a recombinant indirect ELISA for the diagnosis of Theileria sp. (China) infection in small ruminants

Theileria sp. (China) causes severe limitations on the development of the livestock industry in the north-west of China. An enzyme-linked immunosorbent assay (ELISA) based on merozoite homogenate of the parasite for diagnosis of infection has been established; however, cross-reactivity with other small ruminant-infecting piroplasms could not be excluded. Thus, a prerequisite for epidemiological surveys and diagnosis was the establishment of a recombinant protein-based ELISA. To this end, serum from Theileria sp. (China)-infected sheep was used to screen a Theileria lestoquardi expression library, resulting in the identification of a specifically reacting clone with a high identity to the heat shock protein 70 (HSP70) of Theileria parva and Theileria annulata and thus named TlHSP70. An HSP70 homologue was also confirmed to be expressed by Theileria sp. (China) merozoites (TcHSP70). A part of the TlHSP70 protein, found to be conserved in TcHSP70, was recombinantly expressed and used to establish an ELISA. A total of 260 field serum samples tested resulted in a sensitivity and specificity of 94.3 and 89.5%, respectively, in comparison with the merozoite homogenate ELISA. The potentials of the application of the test in epidemiological surveys to map out the prevalence of the disease and for routine diagnostics are described.

Inhibition of hepatitis B virus replication by recombinant small interfering RNAs

RNA interference (RNAi) is a biological phenomenon in which introduction of a small, double-stranded interfering RNAs (siRNAs) into a cell causes a specific degradation of homologous single-stranded RNA. siRNA can be delivered into the cell by different approaches including synthetic RNA, in vitro transcribed RNA and RNA transcribed from polymerase III-based recombinant vectors. As hepatitis B (HB) represents a worldwide health problem, we attempted to develop a fast and easy approach to generation and screening of specific siRNA-targeted HB virus (HBV) genes. Using PCR amplification, specific siRNA expression cassettes (SECs) were developed and used to generate effective siRNAs against HB virus (HBV) replication and gene expression in mammalian cells. After screening, we identified two SECs that expressed siRNAs which efficiently decreased the level of HBV pre-c/c gene expression in transfected Bel-7402 cells by 81.9% and 87.3%, respectively. In addition, the level of HBV DNA was decreased by 83.5% and 85.2% in HepG2 2.2.15 cells, respectively. This study provides (i) a new effective application of RNA interference to study viral gene function and viral replication and (ii) a new tool for the prevention and treatment of human HBV infection.

Treatment of melasma with Pycnogenol

Melasma (or chloasma) is a common disorder of cutaneous hyperpigmentation predominantly affecting sun-exposed areas in women. The pathogenesis of melasma is not fully understood and treatments are frequently disappointing and often associated with side effects. Pycnogenol is a standardized extract of the bark of the French maritime pine (Pinus pinaster), a well-known, potent antioxidant. Studies in vitro show that Pycnogenol is several times more powerful than vitamin E and vitamin C. In addition, it recycles vitamin C, regenerates vitamin E and increases the endogenous antioxidant enzyme system. Pycnogenol protects against ultraviolet (UV) radiation. Therefore its efficacy in the treatment of melasma was investigated. Thirty women with melasma completed a 30-day clinical trial in which they took one 25 mg tablet of Pycnogenol with meals three times daily, i.e. 75 mg Pycnogenol per day. These patients were evaluated clinically by parameters such as the melasma area index, pigmentary intensity index and by routine blood and urine tests. After a 30-day treatment, the average melasma area of the patients decreased by 25.86 +/- 20.39 mm(2) (p < 0.001) and the average pigmentary intensity decreased by 0.47 +/- 0.51 unit (p < 0.001). The general effective rate was 80%. No side effect was observed. The results of the blood and urine test parameters at baseline and at day 30 were within the normal range. Moreover, several other associated symptoms such as fatigue, constipation, pains in the body and anxiety were also improved. To conclude, Pycnogenol was shown to be therapeutically effective and safe in patients suffering from melasma.

Causes of titanium release from plate and screws implanted in rabbits

To investigate the mechanism behind the release of metal from titanium implants in vivo, bone-plate-screw sets consisting of pure titanium were implanted into the legs of rabbits for 48 weeks. Four groups of experiments containing control were conducted: (1) The tibia cut artificially was fixed by one set of bone plate and screws, (2) the same set was implanted separately into muscles in the leg, (3) the set was fixed on the tibia and immediately retrieved, and (4) no implantation was performed. The amounts of titanium in all tissues from knee to ankle were quantified using atomic adsorption spectrometry. The ratio of amounts of titanium detected in the groups (1), (2), and (3) was 100 : 10 : 43. No titanium was detected in the group (4). Causes of the release of titanium in the group (1) include that in the groups (2) and (3). Major causes of titanium release were surgical handling in implantation and wear and/or fretting during experimental-term for 48 weeks. Titanium was also released in the absence of wear. No morphological abnormality was observed around tissue of the implant by biopsy at post-operation week 48.

[Study of the pulmonary heart disease computer-aided diagnosis system based on combining neural network]

We have constructed an expert sub-system for diagnosing pulmonary heart disease with back-propagation (BP) model of typical artificial neural network and BP-Hamming. The system can obtain and represent clinical data, and it has solved the problems such as obtaining automatic knowledge, representation and self-learning. The results of testing demonstrate that the method of neural network can be regarded as an expert sub-system to make intelligent diagnosis of pulmonary heart disease.

Generation of three selenium-containing catalytic antibodies with high catalytic efficiency using a novel hapten design method

A novel strategy for design of haptens that were used to produce catalytic antibodies was developed and three monoclonal antibodies, 3G5, 2F3, and 5C9, were generated using this strategy. These monoclonal antibodies were converted into selenium-containing abzymes by chemically modifying the hydroxyl group of serines followed by sodium hydrogen selenide displacement. These selenium-containing abzymes exhibited remarkable glutathione peroxidase activity, which surpasses the activity of some native glutathione peroxidases. The activities of the selenium-containing abzymes Se-3G5, Se-2F3, and Se-5C9 which catalyzed reduction of hydroperoxides by glutathione were 2.23, 4.20, and 3.79 times that of rabbit liver glutathione peroxidase, respectively. Detailed steady-state kinetics study on Se-2F3 was carried out and the value of k(cat)/K(m) (H(2)O(2)) was found to be 2.11 x 10(7) M(-1) min(-1) which was supposed to be one of the highest among the known catalytic antibodies. The data of association constants and glutathione peroxidase activities of these catalytic antibodies and the steady-state kinetics of Se-2F3 showed that the method might be a remarkably efficient one for generating catalytic antibodies with glutathione peroxidase activity.

A novel dicyclodextrinyl ditelluride compound with antioxidant activity

Reactive oxygen species (ROS) primarily arise from products of normal metabolic activities and are thought to be the etiology of many diseases. A novel dicyclodextrinyl ditelluride (2-TeCD) compound was designed to be a functional mimic of the glutathione peroxidase that normally removes ROS. 2-TeCD exhibited highly catalytic efficiency and good water solubility. Antioxidant activity was studied by using ferrous sulfate/ascorbate-induced mitochondria damage model system. 2-TeCD protected the mitochondria against oxidative damage in a dose-dependent manner and exhibited also great antioxidant ability in comparison with 2-phenyl-1,2-benziososelenazol-3(2H)-one. The mimic may result in better clinical therapies for the treatment of ROS-mediated diseases.

Cloning and expression of a single-chain catalytic antibody that acts as a glutathione peroxidase mimic with high catalytic efficiency

Glutathione peroxidase (GPX) has a powerful role in scavenging reactive oxygen species. In previous papers we have developed a new strategy for generating abzymes: the monoclonal antibody with a substrate-binding site is first prepared, then a catalytic group is incorporated into the monoclonal antibody's binding site by using chemical mutation [Luo, Zhu, Ding, Gao, Sun, Liu, Yang and Shen (1994) Biochem. Biophys. Res. Commun. 198, 1240-1247; Ding, Liu, Zhu, Luo, Zhao and Ni (1998) Biochem. J. 332, 251-255]. Since then we have established a series of catalytic antibodies capable of catalysing the decomposition of hydroperoxides by GSH. The monoclonal antibody 2F3 was raised against GSH-S-2,4-dinitrophenyl t-butyl ester and exhibited high catalytic efficiency, exceeding that of rabbit liver GPX, after chemical mutation. To produce pharmaceutical proteins and to study the reason why it exhibits high catalytic efficiency, we sequenced, cloned and expressed the variable regions of 2F3 antibody as a single-chain Fv fragment (2F3-scFv) in different bacterial strains. The amounts of 2F3-scFv proteins expressed from JM109 (DE3), BL21 (DE3), and BL21 (coden plus) were 5-10%, 15-20% and 25-30% of total bacterial proteins respectively. The 2F3-scFv was expressed as inclusion bodies, purified in the presence of 8 M urea by Co(2+)-immobilized metal-affinity chromatography (IMAC) and renatured to the active form in vitro by gel filtration. The binding constants of the active 2F3-scFv for GSH and GSSG were 2.46 x 10(5) M(-1) and 1.03 x 10(5) M(-1) respectively, which were less by one order of magnitude than that of the intact 2F3 antibody. The active 2F3-scFv was converted into selenium-containing 2F3-scFv (Se-2F3-scFv) by chemical modification of the reactive serine; the GPX activity of the Se-2F3-scFv was 3394 units/micromol, which approaches the activity of rabbit liver GPX.

Subpicosecond conformational dynamics of small peptides probed by two-dimensional vibrational spectroscopy

The observation of subpicosecond fluctuations in the conformation of a small peptide in water is demonstrated. We use an experimental method that is specifically sensitive to conformational dynamics taking place on an ultrafast time scale. Complementary molecular-dynamics simulations confirm that the conformational fluctuations exhibit a subpicosecond component, the time scale and amplitude of which agree well with those derived from the experiment.

Therapeutic potential of bone morphogenetic proteins

Recently, there has been substantial progress in the area of bone morphogenetic protein (BMP) research. This review serves as an up-to-date summary of the history of BMPs, the mechanisms of BMP signalling and the role of BMPs in adipose, kidney, liver, bone and nervous system. The potential of BMPs as therapeutic agents will also be discussed.

National survey on prevalence of cancer pain

OBJECTIVE

To collect nationwide basic data about cancer related pain.

METHODS

Sixty cancer patients in each province were randomly selected to participate in this survey. The subjects represented all stages of cancer, tumor sites, and different demographic characteristics. Two self-designed structured questionnaires including reasons, types of pain and pain management were used by patients and physicians respectively. Subjects were asked to report whether he/she had experienced any type of cancer related pain and filled out the equivalent questionnaire. The severity of pain was assessed by using "visual analogue scale". Original data input and analysis were using EPI-INFO software package.

RESULTS

The result showed that 61.6% (958/1555) of patients had different types of cancer related pain. Majority of pain (85.1%) were caused by advanced cancer. The major reasons (64.4%) for poor management or impedimental factors of pain care are due to patient including over-concern on opioid analgesic addiction, reluctance to report pain or refused to use opioid analgesic until at times when pain is intolerable; 26.8% belonged to physician's reasons including fear to cause addiction on opioid and lack of knowledge about cancer pain management; 16.2% are due to lack of different kinds of opioid analgesic for use and 16.1% belonged to drug regulation.

CONCLUSIONS

The results showed that majority of patients (61.6%) had different types of cancer related pain. In most of patients, cancer pain was relieved when they were treated. The major reason for under-treatment or impeded factors for effective relief of cancer pain was fear of opioid addiction by both medical professionals and patients.

Kinetics study of a selenium-containing ScFv catalytic antibody that mimics glutathione peroxidase

The steady-state kinetics study and some enzymatic characterization of a selenium-containing scFv catalytic antibody (Se-scFv2F3) were carried out. A novel reaction formula of this abzyme-catalyzed reaction was proposed and a rate equation was obtained according to the formula. The constants in the equation were compared with Dalziel's parameters and the exact meanings of these constants were analyzed. The obtained kinetics parameters from the kinetics study of Se-scFv2F3 were analyzed and compared with those of native glutathione peroxidase.

[A gene analysis of the low density lipoprotein receptor in Chinese with homozygous familial hyperchol-esterolemia]

OBJECTIVE

To investigate low density lipoprotein receptor(LDLR) gene mutations in Chinese with familial hyperchol-esterolemia(FH).

METHODS

Genomic DNA was extracted from five unrelated children with clinical diagnosis of homozygous FH, together with their family members. Promoter and all of the 18 exons of LDLR gene were amplified by polymerase chain reaction (PCR) and were analyzed by single strand conformation polymorphism (SSCP). The PCR products of abnormal patterns shown by SSCP were sequenced directly.

RESULTS

Two point mutations (A606T, C263R) were found in two families respectively. The two mutations were only found in China, and C263R is a novel mutation.

CONCLUSION

The two mutations of LDLR gene are the cause of FH and there may be LDLR gene mutations only carried by FH patients in China.

Kinetics study of a selenium-containing ScFv catalytic antibody that mimics glutathione peroxidase

The steady state kinetic study and some enzymic characterization of a selenium-containing scFv catalytic antibody (Se-scFv2F3) was carried out. A novel reaction formula of this abzyme-catalyzed reaction was proposed and a rate equation was gotten according to the formula. The constants in the equation were compared with Dalziel's parameters and the exact meanings of these constants were analyzed. The gotten kinetics parameters from the kinetics study of Se-scFv2F3 were analyzed and compared with that of native glutathione peroxidase.