Inhibition of protein deacetylation by trichostatin A impairs microtubule-kinetochore attachment

Inhibition of protein deacetylation arrests cells in mitosis, but the mechanism is unknown. To understand why inhibiting protein deacetylation causes cell cycle arrest, we treated HeLa cells beyond G1/S transition with trichostatin A (TSA), a potent protein deacetylase inhibitor, and found that the cells arrested at prometaphase with ectopic spindles and unaligned chromosomes. The hyper-acetylated cells encountered a serious microtubule (MT)-kinetochore attachment problem, although the kinetochores are intact at ultrastructural level. By immunofluorescence staining of kinetochore proteins, we found that the pericentromeric H3K9Me3-HP1 pathway was disrupted and that the CENP-A-dependent outer plate protein dynamics of kinetochores was greatly diminished by the drug treatment. The treatment also caused the loss of chromosome passenger complex (CPC), the proposed error checking system, from centromere and impaired the microtubule dynamics of the cells. Overall, we propose that deacetylation inhibition impairs MT-kinetochore attachment through disrupting the centromere function and altering the kinetochore composition and MT dynamics.

Galanin, galanin receptors and drug targets

Galanin, a neuropeptide widely expressed in the central and peripheral nervous systems and in the endocrine system, has been shown to regulate numerous physiological and pathological processes through interactions with three G-protein-coupled receptors, GalR1 through GalR3. Over the past decade, some of the receptor subtype-specific effects have been elucidated through pharmacological studies using subtype selective ligands, as well as through molecular approaches involving knockout animals. In the present review, we summarize the current data which constitute the basis of targeting GalR1, GalR2 and GalR3 for the treatment of various human diseases and pathological conditions, including seizure, Alzheimer's disease, mood disorders, anxiety, alcohol intake in addiction, metabolic diseases, pain and solid tumors.

A Domain Evolution Model for the Ferroelastic Hysteresis of Piezoceramic Materials

In this paper, we model the thermo-ferroelastic hysteresis phenomena under large mechanical loading by using internal state variables that are associated with a statistical description of microstructural domain characterization. This work is to extend our previous work [1, 2] to include the ferroelastic effects. Under large mechanical loading, the total bulk strain includes the mechanical strain and the bulk piezoelectric strain. The piezoelectric strain is the accompanying strain with the evolution of the domain network, which is described by a domain orientation distribution function. In ferroelastic hysteresis, the domain evolution, which is mainly contributed by 90° domain switching, is delineated by the evolution of the associated domain distribution function and further simplified by the evolution of the associated internal state variables that are the parameters of the domain distribution function. For the mechanical field, the mechanical strain is divided into two parts- the elastic strain and the inelastic strain. The inelastic strain is the corresponding internal variable to describe the inelastic behavior under large mechanical loading. Therefore, the remnant strain contains two parts: the remnant piezoelectric strain and remnant inelastic strain. The dissipation and the associated temperature increase per unit cycle in the ferroelastic hysteresis are studied.

A novel hepatitis C virus vaccine approach using recombinant Bacillus Calmette-Guerin expressing multi-epitope antigen

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. HCV infection is associated with high morbidity and has become a major problem in public health. Until now, there has been no effective prophylactic or therapeutic vaccine. BCG, a live vaccine typically used for tuberculosis prevention, has been increasingly utilized as a vector for the expression of recombinant proteins that will induce specific humoral and cellular immune responses. In this study, recombinant BCG (rBCG) was engineered to express a HCV multi-epitope antigen CtEm, and HLA-A2.1 transgenic mice were immunized with rBCG-CtEm. High levels of specific anti-HCV antibodies targeted to mimotopes of HVR1 were detected in the serum. HCV-specific lymphocyte proliferation assay, cytokine determination and cytotoxicity assay indicated that HCV epitope-specific cellular immune responses were elicited in vitro. The rBCG-CtEm immunization conferred protection against infection with the recombinant vaccinia virus (rVV-HCV-CNS) in vivo. These results suggest that rBCG expressing multi-epitope antigen may serve as an effective vaccine against HCV infection.

[Application of integer lifting wavelet transform and subblock coding to medical image compression]

The method of subblock coding for medical image compression is presented by means of the integer lifting wavelet transform. The integer lifting wavelet transform has better effects on improving the processing speed; it can achieve wavelet transform for arbitrary size image and accomplish the transform at current position; furthermore, it can save memory space. The lifting algorithm can deal with the lossless compression and loss compression of image simultaneously, so it is adapted to telemedicine system and medical image compression system. The compression method based on image subblock coding can not only realize controlling BR (bit ratio), but also realize SNR (signal noise ratio) and suit for progressive transform.

Prognostic factors of lupus myelopathy

Myelopathy is a rare but severe neurological manifestation of systemic lupus erythematosus (SLE) with a high morbidity. The factors that contribute to prognosis are unknown. In this study, 14 patients with lupus myelopathy (LM) from our centre were retrospectively studied. Another 23 patients with other neuropsychiatric SLE (NPSLE) features were enrolled as a comparison group. The morbidity of LM was evaluated by the ASIA Impairment Scale. The clinical and serological characteristics and prognostic factors for LM were investigated. The age, gender, duration of SLE, non-CNS disease activity and autoantibody profile in patients with LM was not different in the NPSLE cohort. A relatively low prevalence of anti–phospholipid antibodies (aPL) in LM sera compared to NPSLE (28.6% vs 52.2%, P = 0.19) was observed. Longitudinal lesion detected by magnetic resonance imaging (MRI) was identified in 33.3% of patients with LM, whereas 50% showed focal speckle-like lesions. The morbidity of LM is 50%. Muscle strength of grade 3 or higher on admission was a strong indicator for a better prognosis ( P = 0.006), whereas other parameters including longitudinal lesion, sensory deficit level, disease activity and aPL did not discriminate good from poor outcome in LM. Early aggressive immunosuppressive therapy (within 2 weeks of onset of myelopathy) tend to associate with a favourable outcome ( P = 0.07).

Oval-like hollow intensity distribution of tightly focused femtosecond laser pulses in air

The propagation of a tightly focused femtosecond laser pulse in air has been investigated. Unlike long-distance self-guided propagation of short laser pulses, a novel oval-like hollow distribution of the laser intensity is observed in the experiments and reproduced by the numerical simulations. The formation of the hollow structures can be explained by the interplay between ionization-induced refraction and Kerr self-focusing.

Relationship between endothelial dysfunction, oxidant stress and aspirin resistance in patients with stable coronary heart disease

OBJECTIVE

Interindividual variability of platelet inhibition after aspirin administration has been described. Additionally, aspirin resistance occurs in some individuals, but the mechanism for aspirin resistance is still unknown. The aim of the present study was to examine the role of endothelial dysfunction in aspirin resistance.

METHODS

The antiplatelet effect of aspirin was studied prospectively in 54 consecutive patients with stable coronary heart disease. Platelet aggregation rate was measured and aspirin resistance was defined by a relative inhibition of adenosine diphosphate (5 micromol/L)-induced platelet aggregation of >or=70%. Thrombomodulin (TM) and free tissue factor pathway inhibitor (TFPI) were measured as endothelial dysfunction markers. Erythrocyte superoxide dismutase activity, plasma level of vitamin C, vitamin E and lipoperoxide were measured to estimate the oxidative stress.

RESULTS

Platelet aggregation was positively correlated with TM (r = 0.277, P < 0.05) and TFPI (r = 0.288, P < 0.05) respectively. The TFPI level in aspirin-resistant patients (119.5 +/- 13.5 ng/mL) was significantly higher than that in aspirin-sensitive patients (107.8 +/- 18.9 ng/mL; P < 0.05). There were no statistically significant differences on any indicator of oxidative stress between two groups.

CONCLUSIONS

Endothelial dysfunction is one of the mechanisms for aspirin resistance, whereas oxidative stress may not involve in the process of aspirin resistance.

Group II subfamily secretory phospholipase A2 enzymes: expression in chronic rhinosinusitis with and without nasal polyps

BACKGROUND

Group II subfamily secretory phospholipases A(2) (sPLA(2)s) are the enzymes that can play a major role in inflammation. However, the presence of group II subfamily sPLA(2)s in human sinonasal mucosa and their roles in chronic rhinosinusitis (CRS) are not well known. The purpose of this study was to investigate the expression of group II subfamily sPLA(2)s in human sinonasal mucosa from controls and CRS patients with and without nasal polyps (NPs) and the regulation of expression by proinflammatory cytokines.

METHODS

Surgical samples were investigated by means of reverse transcriptase polymerase chain reaction (RT-PCR) for evaluation of group II subfamily sPLA(2)s mRNA expression, and the presence and location of group II subfamily sPLA(2)s-positive cells were analyzed by means of immunohistochemistry. Furthermore, nasal explant culture and quantitative RT-PCR techniques were used to investigate the effect of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha on group II subfamily sPLA(2)s mRNA production in sinonasal mucosa.

RESULTS

Messenger RNA expression of sPLA(2)-IIA, -IID, and -IIE was significantly upregulated in tissues from CRS patients compared with control tissues. Among CRS patients, patients without NPs showed significantly stronger expression in sinonasal mucosa than patients with NPs of sPLA(2)-IIA mRNA, and weaker expression of sPLA(2)-IIE mRNA. Immunohistochemistry revealed enhanced protein expression of type II sPLA(2)s and specific type IIA sPLA(2) in epithelial cells and submucosal glands in samples from CRS patients. Stronger type IIA sPLA(2) protein expression was found in samples from CRS patients without NPs when compared with NPs. Nasal explant culture experiments demonstrated that mRNA expression of sPLA(2)-IIA, -IID, and -IIE was dramatically induced by IL-1beta and TNF-alpha.

CONCLUSIONS

The expression of some members of group II subfamily of sPLA(2)s is upregulated in CRS and it may result from IL-1beta and TNF-alpha overexpression. Different individual group II subfamily sPLA(2)s may play different roles in the pathogenesis of CRS with and without NPs.

Structure elucidation of compounds extracted from the Chinese medicinal plant Patrinia heterophylla

For several hundred years, Patrinia heterophylla has been used in traditional Chinese medicine as a treatment for abscesses, hepatitis, tonsillitis, ulcers, etc. Recent research suggests that it may also have some anti-cancer activity. We have extracted five pure compounds from this plant; two known flavonols without bio-activity, one known isocoumarin glucoside that exhibits some cytotoxic activity toward HeLa cervical cancer cells, and two novel compounds that show considerable cytotoxic activity toward HeLa cells.

Some p53-binding proteins that can function as arbiters of life and death

Four sets of p53-binding proteins are discussed in this review. These are the E2F family, the ASPP family, Y-box-binding protein YB1, and the prolyl isomerase Pin1. Each appears to play a role in the decision by p53 to induce an arrest of cell proliferation or apoptosis and they may also be independent markers of cancer. Their activities appear to be linked with the cell cycle and they may also interact with each other. In this review, the properties of each protein class are discussed as well as how they affect p53 functions. A model is proposed as to how their activities might be coordinated.

Effects of a novel anti-exospore monoclonal antibody on microsporidialNosema bombycisgermination and reproductionin vitro

A monoclonal antibody (mAb) 3C2, against an exospore protein of the microsporidiumNosema bombycis(N. bombycis) was prepared, and its effects on microsporidial germination and reproductionin vitrowere studied. MAb 3C2 was effective in inhibiting the germination and subsequent infection ofBombyx moricells compared to the control mAb. The antigen was isolated by 2-dimensional gel electrophoresis. Immunoblotting revealed it to be an 84 kDa protein corresponding to pI (7·2) on the 2-D gel. The present results suggest that the antibodies can be used for diagnostic purposes and for developing new therapeutic strategies in controlling microsporidian diseases.

UNC5C is required for spinal accessory motor neuron development

In both invertebrates and vertebrates, UNC5 receptors facilitate chemorepulsion away from a Netrin source. Unlike most motor neurons in the embryonic vertebrate spinal cord, spinal accessory motor neuron (SACMN) cell bodies and their axons translocate along a dorsally directed trajectory away from the floor plate/ventral midline and toward the lateral exit point (LEP). We have recently shown that Netrin-1 and DCC are required for the migration of SACMN cell bodies, in vivo. These observations raised the possibility that vertebrate UNC5 proteins mediate the presumed repulsion of SACMN away from the Netrin-rich ventral midline. Here, we show that SACMN are likely to express UNC5A and UNC5C. Whereas SACMN development proceeds normally in UNC5A null mice, many SACMN cell bodies fail to migrate away from the ventral midline and inappropriately cluster in the ventrolateral spinal cord of mouse embryos lacking UNC5C. These results support an important role for UNC5C in SACMN development.

BM stem cell transplantation rescues pathophysiologic features of aged dystrophic mdx muscle

BACKGROUND

The value of transplantation of BM stem cells in aged (12-month-old) mdx was evaluated because it is thought to be a more ideal model for studying the praxiology of Duchenne muscular dystrophy (DMD). The possible mechanisms of stem cell differentiation were then discussed.

METHODS

BM was isolated from 8-10-week-old male C57 BL/10 mice. After injecting BM cells into 12-month-old female mdx mice through the tail vein, the expression of dystrophin and MyoD was detected at different time points by immunofluorescence staining, RT-PCR and Western blot.

RESULTS

The C57 male mice donor-specific and Y-chromosome-specific sequence could be detected in all female aged mdx mice, implying the success of the transplantation. Expression of dystrophin and MyoD was detected and increased over time.

DISCUSSION

BM cells were recruited to the muscle and partially restored specific pathophysiologic features of the dystrophic muscle in aged mdx mice. Muscle differentiation of BM cells recapitulated embryonic myogenesis.

Region-specific transcriptional changes following the three antidepressant treatments electro convulsive therapy, sleep deprivation and fluoxetine

The significant proportion of depressed patients that are resistant to monoaminergic drug therapy and the slow onset of therapeutic effects of the selective serotonin reuptake inhibitors (SSRIs)/serotonin/noradrenaline reuptake inhibitors (SNRIs) are two major reasons for the sustained search for new antidepressants. In an attempt to identify common underlying mechanisms for fast- and slow-acting antidepressant modalities, we have examined the transcriptional changes in seven different brain regions of the rat brain induced by three clinically effective antidepressant treatments: electro convulsive therapy (ECT), sleep deprivation (SD), and fluoxetine (FLX), the most commonly used slow-onset antidepressant. Each of these antidepressant treatments was applied with the same regimen known to have clinical efficacy: 2 days of ECT (four sessions per day), 24 h of SD, and 14 days of daily treatment of FLX, respectively. Transcriptional changes were evaluated on RNA extracted from seven different brain regions using the Affymetrix rat genome microarray 230 2.0. The gene chip data were validated using in situ hybridization or autoradiography for selected genes. The major findings of the study are: 1. The transcriptional changes induced by SD, ECT and SSRI display a regionally specific distribution distinct to each treatment. 2. The fast-onset, short-lived antidepressant treatments ECT and SD evoked transcriptional changes primarily in the catecholaminergic system, whereas the slow-onset antidepressant FLX treatment evoked transcriptional changes in the serotonergic system. 3. ECT and SD affect in a similar manner the same brain regions, primarily the locus coeruleus, whereas the effects of FLX were primarily in the dorsal raphe and hypothalamus, suggesting that both different regions and pathways account for fast onset but short lasting effects as compared to slow-onset but long-lasting effects. However, the similarity between effects of ECT and SD is somewhat confounded by the fact that the two treatments appear to regulate a number of transcripts in an opposite manner. 4. Multiple transcripts (e.g. brain-derived neurotrophic factor (BDNF), serum/glucocorticoid-regulated kinase (Sgk1)), whose level was reported to be affected by antidepressants or behavioral manipulations, were also found to be regulated by the treatments used in the present study. Several novel findings of transcriptional regulation upon one, two or all three treatments were made, for the latter we highlight homer, erg2, HSP27, the proto oncogene ret, sulfotransferase family 1A (Sult1a1), glycerol 3-phosphate dehydrogenase (GPD3), the orphan receptor G protein-coupled receptor 88 (GPR88) and a large number of expressed sequence tags (ESTs). 5. Transcripts encoding proteins involved in synaptic plasticity in the hippocampus were strongly affected by ECT and SD, but not by FLX. The novel transcripts, concomitantly regulated by several antidepressant treatments, may represent novel targets for fast onset, long-duration antidepressants.

Galanin type 1 receptor knockout mice show altered responses to high-fat diet and glucose challenge

Galanin, a brain and pancreatic peptide with three receptor subtypes (GALR1, GALR2, and GALR3), is hypothesized to participate in energy homeostasis and glucoregulation. Hypothalamic galanin expression is induced by dietary fat, and intra-hypothalamic galanin administration has orexigenic/anabolic properties. Systemic galanin infusion alters glucoregulation in non-human species, partly through direct actions on pancreatic islets. However, the physiologic significance of endogenous galanin-GALR signaling is unclear. The present studies tested the hypotheses that GALR1 deficiency alters food intake and feed efficiency following switches to high-fat diet and that GALR1 deficiency alters whole-body glucose homeostasis. Adult, male GALR1 knockout (-/-), heterozygote (+/-), and C57BL/6J control (+/+) mice were studied. GALR1 deficiency impaired adaptation to a 3-day high-fat diet challenge, leading to increased food intake, feed efficiency and weight gain. However, during the following 2 weeks, GALR1 knockout mice decreased intake, consuming less daily energy than while maintained on low-fat diet and also than heterozygote littermates. Chow-maintained GALR1 knockout mice showed relative hyperglycemia in fed and d-glucose (i.p. 1.5 g/kg)-challenged states. GALR1 knockout mice showed normal food intake, feed efficiency and weight accrual on low-fat diets, normal fasted glucose levels, and normal glucose sensitivity to porcine insulin (i.p. 1 IU/kg) in vivo. The results support the hypotheses that galanin-GALR1 systems help adapt food intake and metabolism to changes in dietary fat and modulate glucose disposition in mice.

ASPP: a new family of oncogenes and tumour suppressor genes

The apoptosis stimulating proteins of p53 (ASPP) family consists of three members, ASPP1, ASPP2 and iASPP. They bind to proteins that are key players in controlling apoptosis (p53, Bcl-2 and RelA/p65) and cell growth (APCL, PP1). So far, the best-known function of the ASPP family members is their ability to regulate the apoptotic function of p53 and its family members, p63 and p73. Biochemical and genetic evidence has shown that ASPP1 and ASPP2 activate, whereas iASPP inhibits, the apoptotic but not the cell-cycle arrest function of p53. The p53 tumour suppressor gene, one of the most frequently mutated genes in human cancer, is capable of suppressing tumour growth through its ability to induce apoptosis or cell-cycle arrest. Thus, the ASPP family of proteins helps to determine how cells choose to die and may therefore be a novel target for cancer therapy.

A comparison of CFU-GM, BFU-E and endothelial progenitor cells using ex vivo expansion of selected cord blood CD133+ and CD34+ cells

BACKGROUND

CD133 is a newly developed hematopoietic stem cell marker but little is known about its function. Whether CD133(+) cell selection provides any advantage over CD34(+) selection for hematopoietic stem cell isolation and transplantation is unclear. The present study compared colony formation and endothelial cell differentiation of these two cell types from umbilical cord blood (UCB).

METHODS

Mononuclear cells from the same UCB samples were used for both CD133(+) and CD34(+) cell selection. Cells with 97.1% purity were incubated in semi-solid culture medium containing stem cell growth factor (SCGF) and G-CSF or erythropoietin (EPO). Purified cells were also cultured in M199 containing vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and insulin-like growth factor-1 (IGF-1).

RESULTS

CD34(+) and CD133(+) cells produced similar numbers of CFU-GM colonies (median 43.25 and 30.5, respectively; P>0.2). However, a greater than four-fold difference in BFU-E colony formation was observed from CD34(+) cells compared with CD133(+) cells (median 35 and 8, respectively; P<0.04). CD34(+) cells gave rise to endothelial-like cells when stimulated with VEGF, bFGF and IGF-1. CD133(+) cells were unable produce this cell type under the same conditions.

DISCUSSION

CD133(+) cells produced smaller BFU-E colonies and were unable to differentiate into mature endothelial cells. CD34(+) cells contained endothelial progenitors that could differentiate into mature cells of this lineage. Based on these data, it appears that CD133 offers no distinct advantage over CD34 as a selective marker for immunoaffinity-based isolation of hematopoietic stem cells and endothelial progenitor cells.

Structure-activity relationship studies on ADAM protein-integrin interactions

The ADAM (a disintegrin and metalloprotease) family of proteins possess multi-domain structures composed of a signal peptide, a prodomain, a metalloprotease domain, a disintegrin-like domain, a cysteine rich domain, an epidermal growth factor-like domain, a transmembrane domain and cytoplasmic tail. The disintegrin-like domain shares sequence similarity with the soluble venom disintegrins, a family of proteins which are potent inhibitors of integrin-mediated platelet aggregation and cell adhesion. Several ADAMs have been reported to interact with integrins, and the disintegrin-like domain may be crucial part in this respect. A description of structure-activity relationship of ADAM proteins interacting with integrin is outlined in this review. The review highlights recent reports on potential integrin family for ADAMs and how ADAMs selectively modulate interaction for integrin mediated cell function. Lastly, it describes progress in understanding the structural features and functional roles of the ADAMs in normal and pathological conditions and how this insight may assist the development of new therapeutic approaches.