Diffusion Tensor Imaging for Predicting Hand Motor Outcome in Chronic Stroke Patients

OBJECTIVE: Previous studies have indicated that diffusion tensor imaging (DTI) values are related to clinical outcome in stroke patients. This prospective study explored whether DTI values were predictive for hand function outcome in chronic stroke patients. METHODS: The DTI parameters (rλ1, rλ23, fractional anisotropy [rFA] and mean diffusivity [rMD]) were investigated in patients with completely paralysed hands (CPH; n = 10) or partially paralysed hands (PPH; n = 10), by two methods of analysis: segment of the corticospinal tract [sCST] analysis; pure region of interest [ROI] analysis. Spearman's correlation coefficient was used to assess the correlation between the DTI parameters and the following clinical measures: Fugl—Meyer Assessment [FMA]; National Institutes of Health Stroke Scale [NIHSS]. RESULTS: Significant differences were found between CPH and PPH for rFA and rλ23 (sCST analysis) and for rMD and rλ23 (ROI analysis). The rλ23 (sCST analysis) correlated with the NIHSS; the rMD (sCST analysis) correlated with the FMA (hand). CONCLUSION: The three parameters, rFA, rλ23 and rMD may have predictive value for evaluating hand function outcome in chronic stroke patients.

FOXC1 regulates the functions of human basal-like breast cancer cells by activating NF-κB signaling

Human basal-like breast cancer (BLBC) is an enigmatic and aggressive malignancy with a poor prognosis. There is an urgent need to identify therapeutic targets for BLBC, because current treatment modalities are limited and not effective. The forkhead box transcription factor FOXC1 has recently been identified as a critical functional biomarker for BLBC. However, how it orchestrates BLBC cells was not clear. Here we show that FOXC1 activates the transcription factor nuclear factor-κB (NF-κB) in BLBC cells by increasing p65/RelA protein stability. High NF-κB activity has been associated with estrogen receptor-negative breast cancer, particularly BLBC. The effect of FOXC1 on p65/RelA protein stability is mediated by increased expression of Pin1, a peptidyl-prolyl isomerase. FOXC1 requires NF-κB for its regulation of cell proliferation, migration and invasion. Notably, FOXC1 overexpression renders breast cancer cells more susceptible to pharmacological inhibition of NF-κB. These results suggest that BLBC cells may rely on FOXC1-driven NF-κB signaling. Interventions of this pathway may provide modalities for the treatment of BLBC.

Microarray analysis of normal and abnormal chick ventricular myocardial development

The left and right ventricle originate from distinct parts of the cardiac tube, and several genes are known to be differentially expressed in these compartments. The aims of this study were to determine developmental differences in gene expression between the left and right ventricle, and to assess the effect of altered hemodynamic loading. RNA was extracted from isolated left and right normal chick embryonic ventricles at embryonic day 6, 8, and 10, and from day 8 left atrial ligated hearts with hypoplastic left and dilated right ventricles. cRNA was hybridized to Affymetrix Chicken Genome array according to manufacturer protocols. Microarray analysis identified 302 transcripts that were differentially expressed between the left and right ventricle. Comparative analysis detected 91 genes that were different in left ventricles of ligated hearts compared to age-matched ventricles, while 66 were different in the right ones. A large number of the changes could be interpreted as a delay of normal maturation. The approach described in this study could be used as one of the measures to gauge success of surgical procedures for congenital heart disease and help in determining the optimal time frame for intervention to prevent onset of irreversible changes.

sFRP-1: A functional prognostic marker for gastric cancer?

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Background: Despite being a leading cause of cancer-related death world wide, gastric adenocarcinoma (GA) lacks distinctive biomarkers and targeted therapies. Underexpression of the E-cadherin gene in GA is associated with an aggressive phenotype and a poor prognosis but the mechanisms of this difference are poorly understood. Developing effective therapies for GA requires identification of critical functional markers and deeper understanding of its pathophysiology.

Methods: Unsupervised hierarchical clustering analysis of a publicly available 230-sample GA microarray dataset identified a prominent cluster (21.7%) associated with underexpression of E-cadherin and overexpression of a Wnt-family protein: secreted frizzled-related protein 1 (sFRP-1). Archival GA specimens were then assessed for the expression of sFRP-1 by immunohistochemistry. Prognostic significance was assessed using univariate and multivariate analyses. GA cell lines transfected with sFRP-1 were used to determine the role of sFRP-1 in gastric cancer.

Results: 85 patients with GA underwent surgery with curative intent; 39 stained positive for sFRP-1 (46%). In this positive group, sFRP-1 staining was focal; was commonly found on the leading edge of the infiltrating tumor mass; and was not restricted to one histopathologic group, grade, or clinical stage. On univariate analysis T stage, nodal involvement, pathologic stage, nuclear grade, E-cadherin status and sFRP-1 status were predictive of overall survival. In a multivariate model, T stage (p < 0.001), nuclear grade (p < 0.001), E-cadherin status (p = 0.031) and sFRP-1 status (p = 0.0097) were predictive of overall survival. Overexpression of sFRP-1 in GA cell lines induced mesenchymal phenotype, enhanced growth and stem cell-like properties. sFRP-1 also attenuated Wnt signaling and E-cadherin expression, but potentiated Notch and Hedgehog signaling known to be involved in GA progression. These findings suggest a Wnt-independent mechanism mediated by sFRP-1.

Conclusions: The aggressive biological subtype of gastric cancer may be linked to overexpression of sFRP-1. Our findings identify sFRP-1 as a functional prognostic biomarker for gastric cancer, which may serve as a potential therapeutic target.

No significant financial relationships to disclose.

The protein kinase Pak4 disrupts mammary acinar architecture and promotes mammary tumorigenesis

The Pak4 serine/threonine kinase is highly expressed in many cancer cell lines and human tumors. While several studies have addressed the role for Pak4 in transformation of fibroblasts, most human cancers are epithelial in origin. Epithelial cancers are associated not only with changes in cell growth, but also with changes in the cellular organization within the three dimensional (3D) architecture of the affected tissues. Here we used immortalized mouse mammary epithelial cells (iMMECs) as a model system to study the role for Pak4 in mammary tumorigenesis. iMMECs are an excellent model system for studying breast cancer they can grow in 3D-epithelial cell culture, where they form acinar structures that recapitulate in vivo mammary morphogenesis. While Pak4 is expressed at low levels in wild type iMMECs, it is overexpressed in response to oncogenes, such as oncogenic Ras and Her2/neu. Here we found that overexpression of Pak4 in iMMECs leads to changes in 3D acinar architecture that are consistent with oncogenic transformation. These include decreased central acinar cell death, abrogation of lumen formation, cell polarity alterations, and deregulation of acinar size and cell number. Furthermore, iMMECs overexpressing Pak4 form tumors when implanted into the fat pads of athymic mice. Our results suggest that overexpression of Pak4 triggers events that are important for the transformation of mammary epithelial cells. This is likely to be due to the ability of Pak4 to inhibit apoptosis and promote cell survival, and thus subsequent uncontrolled proliferation, and to its ability to deregulate cell shape and polarity.

Effects of surfactant replacement on alveolar overdistension and plasma cytokines in ventilator-induced lung injury

BACKGROUND

Overdistension of the lung causes ventilator-induced lung injury (VILI) accompanied by surfactant abnormalities and inflammatory changes. We investigated the effects of surfactant replacement on overdistension of the terminal airspaces and plasma cytokine levels in VILI.

METHODS

VILI was induced by high-pressure ventilation (HPV) in rats anesthetized with pentobarbital, followed by ventilation for 2 h in the maintenance mode (tidal volume=10 ml/kg, positive end-expiratory pressure = 7.5 cmH(2)O) with or without surfactant replacement. The sizes of the terminal airspaces were determined after fixing the lungs at an airway pressure of 10 cmH(2)O on deflation. Cytokine levels were assessed by enzyme-linked immunosorbent assay.

RESULTS

The mean ratio of the largest terminal airspace size class (> or = 64,000 microm(2)) was increased from 13.4% to 32.0% by HPV (P<0.05). After maintenance-mode ventilation, the ratio decreased to 16.1% with surfactant replacement (P<0.05), but increased to 44.6% without surfactant replacement (P<0.05). Mean macrophage inflammatory protein-2 (MIP-2) levels in the plasma increased from <0.02 to 6.9 ng/ml with HPV (P<0.05), and further increased to > or = 11.8 ng/ml, regardless of surfactant replacement after maintenance-mode ventilation. Similar tendencies were observed in the interleukin (IL)-6 and IL-10 levels. Tumor necrosis factor-alpha levels were almost negligible during the experiment.

CONCLUSION

In rats with VILI, surfactant replacement reversed overdistension of the terminal airspaces that may induce barotrauma, but not upregulation of MIP-2, IL-6, and IL-10 within 2 h.

Erythropoietin promotes spinal cord-derived neural progenitor cell proliferation by regulating cell cycle

Erythropoietin (EPO) regulates the proliferation and differentiation of erythroid cells by binding to its specific transmembrane receptor (EPOR). The presence of EPO and its receptor in the CNS suggests a different function for EPO other than erythropoiesis. The purpose of the present study was to examine EPOR expression and the role of EPO in the proliferation of neonatal spinal cord-derived neural progenitor cells. The effect of EPO on cell cycle progression was also examined, as well as the signaling cascades involved in this process. Our results showed that EPOR was present in the neural progenitor cells and EPO significantly enhanced their proliferation. Cell cycle analysis of EPO-treated neural progenitor cells indicated a reduced percentage of cells in G0/G1 phase, whereas the cell proliferation index (S phase plus G2/M phase) was increased. EPO also increased the proportion of 5-bromo-2-deoxyuridine (BrdU)-positive cells. With respect to the cell cycle signaling, we examined the cyclin-dependent kinases D1, D2 and E, and cyclin-dependent kinase inhibitors, p21cip1, p27kip1 and p57kip2. No significant differences were observed in the expression of these transcripts after EPO administration. Interestingly, the anti-apoptotic factors, mcl-1 and bcl-2 were significantly increased twofold. Moreover, these specific effects of EPO were eliminated by incubation of the progenitor cells with anti-EPO neutralizing antibody. Those observations suggested that EPO may play a role in normal spinal cord development by regulating cell proliferation and apoptosis.

Positive inotropic effect of PHR0007 (2-(4-(4-(Benzyloxy)-3-methoxybenzyl)piperazin-1-)-N-(1-methyl-4,5-dihydro[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide) on atrial dynamics in beating rabbit atria

The aim of the present study was to examine the positive inotropic effects and mechanism of action of PHR0007 (2-(4-(4-(Benzyloxy)-3-methoxybenzyl)piperazin-1-)-N-(1-methyl-4,5-dihydro[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide) on beating rabbit atria. Atria were obtained from New Zealand white rabbits, and experiments performed using a perfused beating atrial model. The effects of PHR0007 (1, 30, or 100 μmol/L), and of the protein kinase inhibitors, staurosporine (1.0 μmol/L) or H-89 (10 μmol/L), plus PHR0007 (30 μmol/L), on atrial pulse pressure and stroke volume were analyzed. PHR0007 significantly increased atrial pulse pressure and atrial stroke volume in beating rabbit atria compared with control baseline levels. These effects of PHR0007 were completely blocked by pretreatment with either staurosporine (a nonspecific protein kinase inhibitor) or H-89 (a cAMP-dependent protein kinase A inhibitor). In addition, 3-isobutyl-1-methylxanthine (IBMX), a non-specific inhibitor of phosphodiesterases (PDEs), completely blocked the positive inotropic effect of PHR0007 on atrial dynamics, but forskolin, an activator of adenylyl cyclases (AC), failed to modulate PHR0007-induced increases in atrial pulse pressure and stroke volume. In conclusion, these data suggest that PHR0007 produces a positive inotropic effect in rabbit atria via the PDE-cAMP-PKA signaling pathway.

Role of FOXC1 in regulation of basal-like/triple-negative breast cancer

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Background: Class identification studies have proposed 3 prognostically relevant molecular subtypes of breast cancer: luminal, HER2 and basal-like. The latter is associated with poor prognosis but its molecular basis is not clear. We hypothesized a direct correlation between FOXC1 expression and basal-like breast cancer. Methods: Expression of FOXC1, CK5, CK14, EGFR, c-Kit, αB-crystallin, ITGB4 and FOXC2 in basal-like breast cancer was examined using publicly available microarray datasets. A molecular signature of 40 genes sharing co-ordinate up or down regulation with FOXC1 was identified on one microarray (49 patients) and validated on 5 other microarrays (1,232 patients). The clinical significance of FOXC1 gene expression and the FOXC1 gene signature was evaluated using censored survival data. FOXC1 protein expression was assessed by immunohistochemistry (IHC) of a 96-sample breast cancer tissue microarray. Normal breast epithelial, luminal and basal breast cancer cells transfected with FOXC1 vectors were evaluated for cell proliferation, migration and invasion. Results: FOXC1 was found to be consistently and exclusively upregulated in basal-like triple negative breast cancer and was associated with poor overall survival (p<0.0001). The FOXC1 gene signature accurately predicted the basal-like phenotype. IHC analysis of FOXC1 protein expression in human breast cancers confirmed its potential to be used as a clinical biomarker of basal-like breast cancer. Normal breast epithelial cells and luminal breast cancer cells with low or no FOXC1 expression underwent epithelial-to-mesenchymal transition and displayed increased cellular proliferation, migration, invasion, and expression of basal cell markers when FOXC1 was overexpressed. In contrast, knockdown of FOXC1 by shRNA in basal-like breast cancer cells conferred luminal phenotype. Breast cancer progression-linked signaling pathways like NF-κB and p38MAPK were significantly stimulated in basal-like breast cancer as well as by in vitro FOXC1 overexpression. Conclusions: FOXC1 is a dominant determinant of the basal-like phenotype of breast cancer. We propose FOXC1 to be the single best molecular marker of and a potential therapeutic target for basal-like / triple negative breast cancer.

No significant financial relationships to disclose.

Genetic mapping by single sperm typing

The polymerase chain reaction makes it possible to analyse DNA sequences in a single cell and has led to a new approach for constructing genetic maps. We describe a procedure called 'sperm typing' which can accurately classify individual meiotic products as recombinant of non-recombinant. This permits the linkage relationships among DNA polymorphisms to be determined without pedigree analysis.

Role of endothelial nitric oxide synthetase in arteriogenesis after stroke in mice

Arteriogenesis supports restored perfusion in the ischemic brain and improves long-term functional outcome after stroke. We investigate the role of endothelial nitric oxide synthetase (eNOS) and a nitric oxide (NO) donor, (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl) amino] diazen-1-ium-1, 2-diolate (DETA-NONOate), in promoting arteriogenesis after stroke. Adult wild-type (WT, n=18) and eNOS-knockout (eNOS(-/-), n=36) mice were subjected to transient (2.5 h) right middle cerebral artery occlusion (MCAo) and were treated with or without DETA-NONOate (0.4 mg/kg) 24 h after MCAo. Functional evaluation was performed. Animals were sacrificed 3 days after MCAo for arterial cell culture studies, or 14 days for immunohistochemical analysis. Consistent with previous studies, eNOS(-/-) mice exhibited a higher mortality rate (P<0.05, n=18/group) and more severe neurological functional deficit after MCAo than WT mice (P<0.05, n=12/group). Decreased arteriogenesis, was evident in eNOS(-/-) mice compared with WT mice, as demonstrated by reduced vascular smooth muscle cell (VSMC) proliferation, arterial density and diameter in the ischemic brain. eNOS(-/-) mice treated with DETA-NONOate had a significantly decreased mortality rate and improved functional recovery, and exhibited enhanced arteriogenesis identified by increased VSMC proliferation, and upregulated arterial density and diameter compared to eNOS(-/-) mice after stroke (P<0.05, n=12/group). To elucidate the mechanisms underlying eNOS/NO mediated arteriogenesis, VSMC migration was measured in vitro. Arterial cell migration significantly decreased in the cultured common carotid artery (CCA) derived from eNOS(-/-) mice 3 days after MCAo compared to WT arterial cells. DETA-NONOate-treatment significantly attenuated eNOS(-/-)-induced decrease of arterial cell migration compared to eNOS(-/-) control artery (P<0.05; n=6/group). Using VSMC culture, DETA-NONOate significantly increased VSMC migration, while inhibition of NOS significantly decreased VSMC migration (P<0.05; n=6/group). Our data indicated that eNOS not only promotes vascular dilation but also increases VSMC proliferation and migration, and thereby enhances arteriogenesis after stroke. Therefore, increase eNOS may play an important role in regulating of arteriogenesis after stroke.

Developmental Vitamin D Deficiency (DVD) and Brain Dopamine Ontogeny

Our group has pioneered research indicating that Developmental vitamin D (DVD) deficiency (a candidate risk factor for schizophrenia) alters both brain development and function. We have convergent evidence indicating a disturbance in dopamine signalling in this model. 1stly the superior colliculus (the proto-basal ganglia) is the initial site where the vitamin D receptor is expressed in foetal brain; 2ndly we show a reduction in Catechol-O-methyl transferase (a major metabolic enzyme for dopamine) in these foetal brains; 3rdly dopamine metabolites in the DVD deplete neonatal brain reflect this enzymatic change. When we allow these animals to mature under vitamin D normal conditions we repeatedly observe alterations in both spontaneous and psychomimetic enhanced locomotion. Consistent with the theme of persistent changes in dopamine signalling in this model we now present new data showing that dopamine transporter density and/or affinity are altered in DVD deplete female offspring whilst DA 1 receptor density and dopamine cell number are reduced in DVD deplete male offspring (all P< 0.05 n>8).

Our most recent studies indicate that Nurr-1, a nuclear transcription regulator important in both bone and dopamine neuron development and survival may be a molecular mediator of these processes. Nurr-1 is upregulated by parathyroid hormone (PTH). PTH levels are 2-3 fold greater in vitamin D deficient Dams across gestation. Most importantly we have just shown that Nurr-1 is dose-dependently upregulated by parathyroid hormone (PTH) in a neuroblastoma cell line.

Conclusions:

Our findings strongly suggest that vitamin D directly (or indirectly via PTH) mediates dopamine neuron development.

Effect of 2-mercaptoethanol and cysteine supplementation during in vitro maturation on the developmental competence of oocytes from hormone-stimulated lambs

The objective was to determine the effect of 2-mercaptoethanol and cysteine on in vitro developmental competence of oocytes from lambs (4-8-week old) stimulated with eCG and pFSH. Oocytes were matured in medium (TCM199) with no supplement (Control group) or with 100 microM 2-mercaptoethanol and 600 microM cysteine (GSH group). Oocytes from adult sheep were also included (Adult group). The addition of 2-mercaptoethanol and cysteine did not improve nuclear maturation or microtubule configuration 12, 15, 18, or 24 h after placement in maturation medium. Sperm head decondensation and male pronucleus formation were evaluated at 6, 12, and 18 h after commencement of IVF; sperm decondensation appeared earlier in the GSH group (6h after the start of IVF). There were differences (P<0.05) between the Control group and the GSH and Adult groups for: fertilization rate at both 12 h (55.4, 77.0, and 80.6%, respectively) and 18 h (67.9, 86.9, and 88.7%); parthenogenesis rate at both 12 h (25.0, 10.8, and 5.6%) and 18 h (28.3, 9.8, and 4.5%); and polyspermy rate at 18 h (26.4, 4.9, and 5.7%). Blastocyst rate at 7d was higher in the GSH group than the Control group (23.9% vs. 14.9%, P<0.05), but both were lower (P<0.05) than the Adult group (38.3%). The addition of 2-mercaptoethanol and cysteine improved sperm decondensation and rates of fertilization and the blastocyst development to 7d, with no effect on blastocyst rate at 9 d.