Purification and cloning of amyloid precursor protein beta-secretase from human brain

Proteolytic processing of the amyloid precursor protein (APP) generates amyloid beta (Abeta) peptide, which is thought to be causal for the pathology and subsequent cognitive decline in Alzheimer's disease. Cleavage by beta-secretase at the amino terminus of the Abeta peptide sequence, between residues 671 and 672 of APP, leads to the generation and extracellular release of beta-cleaved soluble APP, and a corresponding cell-associated carboxy-terminal fragment. Cleavage of the C-terminal fragment by gamma-secretase(s) leads to the formation of Abeta. The pathogenic mutation K670M671-->N670L671 at the beta-secretase cleavage site in APP, which was discovered in a Swedish family with familial Alzheimer's disease, leads to increased beta-secretase cleavage of the mutant substrate. Here we describe a membrane-bound enzyme activity that cleaves full-length APP at the beta-secretase cleavage site, and find it to be the predominant beta-cleavage activity in human brain. We have purified this enzyme activity to homogeneity from human brain using a new substrate analogue inhibitor of the enzyme activity, and show that the purified enzyme has all the properties predicted for beta-secretase. Cloning and expression of the enzyme reveals that human brain beta-secretase is a new membrane-bound aspartic proteinase.

ABFs, a family of ABA-responsive element binding factors

Abscisic acid (ABA) plays an important role in environmental stress responses of higher plants during vegetative growth. One of the ABA-mediated responses is the induced expression of a large number of genes, which is mediated by cis-regulatory elements known as abscisic acid-responsive elements (ABREs). Although a number of ABRE binding transcription factors have been known, they are not specifically from vegetative tissues under induced conditions. Considering the tissue specificity of ABA signaling pathways, factors mediating ABA-dependent stress responses during vegetative growth phase may thus have been unidentified so far. Here, we report a family of ABRE binding factors isolated from young Arabidopsis plants under stress conditions. The factors, isolated by a yeast one-hybrid system using a prototypical ABRE and named as ABFs (ABRE binding factors) belong to a distinct subfamily of bZIP proteins. Binding site selection assay performed with one ABF showed that its preferred binding site is the strong ABRE, CACGTGGC. ABFs can transactivate an ABRE-containing reporter gene in yeast. Expression of ABFs is induced by ABA and various stress treatments, whereas their induction patterns are different from one another. Thus, a new family of ABRE binding factors indeed exists that have the potential to activate a large number of ABA/stress-responsive genes in Arabidopsis.

The corneal wound healing response: cytokine-mediated interaction of the epithelium, stroma, and inflammatory cells

The corneal wound healing cascade is complex and involves stromal-epithelial and stromal-epithelial-immune interactions mediated by cytokines. Interleukin-1 appears to be a master modulator of many of the events involved in this cascade. Keratocyte apoptosis is the earliest stromal event noted following epithelial injury and remains a likely target for modulation of the overall wound healing response. Other processes such as epithelial mitosis and migration, stromal cell necrosis, keratocyte proliferation, myofibroblast generation, collagen deposition, and inflammatory cell infiltration contribute to the wound healing cascade and are also likely modulated by cytokines derived from corneal cells, the lacrimal gland, and possibly immune cells. Many questions remain regarding the origin and fate of different cell types that contribute to stromal wound healing. Over a period of months to years the cornea returns to a state similar to that found in the unwounded normal cornea.

Phase III, randomised trial of avelumab versus physician's choice of chemotherapy as third-line treatment of patients with advanced gastric or gastro-oesophageal junction cancer: primary analysis of JAVELIN Gastric 300

Background

There currently are no internationally recognised treatment guidelines for patients with advanced gastric cancer/gastro-oesophageal junction cancer (GC/GEJC) in whom two prior lines of therapy have failed. The randomised, phase III JAVELIN Gastric 300 trial compared avelumab versus physician’s choice of chemotherapy as third-line therapy in patients with advanced GC/GEJC.

Patients and methods

Patients with unresectable, recurrent, locally advanced, or metastatic GC/GEJC were recruited at 147 sites globally. All patients were randomised to receive either avelumab 10 mg/kg by intravenous infusion every 2 weeks or physician’s choice of chemotherapy (paclitaxel 80 mg/m² on days 1, 8, and 15 or irinotecan 150 mg/m² on days 1 and 15, each of a 4-week treatment cycle); patients ineligible for chemotherapy received best supportive care. The primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), objective response rate (ORR), and safety.

Results

A total of 371 patients were randomised. The trial did not meet its primary end point of improving OS {median, 4.6 versus 5.0 months; hazard ratio (HR)=1.1 [95% confidence interval (CI) 0.9–1.4]; P = 0.81} or the secondary end points of PFS [median, 1.4 versus 2.7 months; HR=1.73 (95% CI 1.4–2.2); P > 0.99] or ORR (2.2% versus 4.3%) in the avelumab versus chemotherapy arms, respectively. Treatment-related adverse events (TRAEs) of any grade occurred in 90 patients (48.9%) and 131 patients (74.0%) in the avelumab and chemotherapy arms, respectively. Grade ≥3 TRAEs occurred in 17 patients (9.2%) in the avelumab arm and in 56 patients (31.6%) in the chemotherapy arm.

Conclusions

Treatment of patients with GC/GEJC with single-agent avelumab in the third-line setting did not result in an improvement in OS or PFS compared with chemotherapy. Avelumab showed a more manageable safety profile than chemotherapy.

Trial registration

ClinicalTrials.gov: NCT02625623.

Wisconsin Card Sorting Test performance in patients with focal frontal and posterior brain damage: effects of lesion location and test structure on separable cognitive processes

Forty-six patients with single focal lesions (35 frontal, 11 nonfrontal) were administered the Wisconsin Card Sorting Test (WCST) under three conditions of test administration. The three conditions varied in the amount of external support provided via specificity of instructions. The WCST, while a multifactorial test, is specifically sensitive to the effects of frontal lobe damage if deficits in language comprehension and visual-spatial search are controlled. There is also specificity of functioning within the frontal lobes: patients with inferior medial frontal lesions, unilateral or bilateral, were not impaired on the standard measures although they had increased loss of set when informed of the sorting categories. Verbal instructions may provide a probe to improve diagnosis and prognosis, assessment of the potential efficacy of treatment, and the time frame of plasticity of specific cognitive operations.

Rehabilitation of executive functioning: an experimental-clinical validation of goal management training

Two studies assessed the effects of a training procedure (Goal Management Training, GMT), derived from Duncan's theory of goal neglect, on disorganized behavior following TBI. In Study 1, patients with traumatic brain injury (TBI) were randomly assigned to brief trials of GMT or motor skills training. GMT, but not motor skills training, was associated with significant gains on everyday paper-and-pencil tasks designed to mimic tasks that are problematic for patients with goal neglect. In Study 2, GMT was applied in a postencephalitic patient seeking to improve her meal-preparation abilities. Both naturalistic observation and self-report measures revealed improved meal preparation performance following GMT. These studies provide both experimental and clinical support for the efficacy of GMT toward the treatment of executive functioning deficits that compromise independence in patients with brain damage.

Suppression of a CFTR premature stop mutation in a bronchial epithelial cell line

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) protein. While 70% of CF chromosomes carry a deletion of the phenylalanine residue 508 (deltaF508) of CFTR, roughly 5% of all CF chromosomes carry a premature stop mutation. We reported that the aminoglycoside antibiotics G-418 and gentamicin can suppress two premature stop mutations [a stop codon in place of glycine residue 542 (G542X) and arginine residue 553 (R553X)] when expressed from a CFTR cDNA in HeLa cells. Suppression resulted in the synthesis of full-length CFTR protein and the appearance of a cAMP-activated anion conductance characteristic of CFTR function. However, it was unclear whether this approach could restore CFTR function in cells expressing mutant forms of CFTR from the nuclear genome. We now report that G-418 and gentamicin are also capable of restoring CFTR expression in a CF bronchial epithelial cell line carrying the CFTR W1282X premature stop mutation (a stop codon in place of tryptophan residue 1282). This conclusion is based on the reappearance of cAMP-activated chloride currents, the restoration of CFTR protein at the apical plasma membrane, and an increase in the abundance of CFTR mRNA levels from the W1282X allele.

Evidence that systemic gentamicin suppresses premature stop mutations in patients with cystic fibrosis

Here we report the effects of gentamicin treatment on cystic fibrosis transmembrane regulator (CFTR) production and function in CF airway cells and patients with CF with premature stop mutations. Using immunocytochemical and functional [6-methoxy-N- (3-sulfopropyl) quinolinium (SPQ)-based] techniques, ex vivo exposure of airway cells from stop mutation CF patients led to the identification of surface-localized CFTR in a dose-dependent fashion. Next, five patients with CF with stop mutations and five CF control subjects were treated with parenteral gentamicin for 1 wk, and underwent repeated in vivo measures of CFTR function (nasal potential difference [PD] measurements and sweat chloride [Cl(-)] testing). During the treatment period, the number of nasal PD readings in the direction of Cl(-) secretion was increased approximately 3-fold in the stop mutation patient group compared with controls (p < 0.001), and four of five stop mutation patients with CF had at least one reading during gentamicin treatment with a Cl(-) secretory response of more than -5 mV (hyperpolarized). A response of this magnitude was not seen in any of the CF control subjects (p < 0.05). In an independent series of experiments designed to test the ability of repeat nasal PDs to detect wild-type CFTR function, evidence of Cl(-) secretion was seen in 88% of control (non-CF) nasal PDs, and 71% were more than -5 mV hyperpolarized. Together, these results suggest that gentamicin treatment can suppress premature stop mutations in airway cells from patients with CF, and produce small increases in CFTR Cl(-) conductance (as measured by the nasal PD) in vivo.

Effects of purified green and black tea polyphenols on cyclooxygenase- and lipoxygenase-dependent metabolism of arachidonic acid in human colon mucosa and colon tumor tissues

The effects of green and black tea polyphenols on cyclooxygenase (COX)- and lipoxygenase (LOX)-dependent arachidonic acid metabolism in normal human colon mucosa and colon cancers were investigated. At a concentration of 30 microg/mL, (-)-epigallocatechin-3-gallate (EGCG), (-)-epigallocatechin (EGC), and (-)-epicatechin-3-gallate (ECG) from green tea and theaflavins from black tea inhibited LOX-dependent activity by 30-75%. The formation of 5-, 12-, and 15-LOX metabolites was inhibited to a similar extent. Tea polyphenols also inhibited COX-dependent arachidonic acid metabolism in microsomes from normal colon mucosa, with ECG showing the strongest inhibition. The formation of thromboxane (TBX) and 12-hydroxyheptadecatrienoic acid (HHT) was decreased to a greater extent than other metabolites. The inhibitory effects of tea polyphenols on COX activity, however, were less pronounced in tumor microsomes than in normal colon mucosal microsomes. Theaflavins strongly inhibited the formation of TBX and HHT, but increased the production of prostaglandin E(2) (PGE(2)) in tumor microsomes. The enhancing effect of theaflavins on PGE(2) production was related to the COX-2 level in the microsomes. Although theaflavin inhibited ovine COX-2, its activity in the formation of PGE(2) was stimulated by theaflavin when ovine COX-2 was mixed with microsomes, suggesting that theaflavin affects the interaction of COX-2 with other microsomal factors (e.g. PGE synthase). The present results indicate that tea polyphenols can affect arachidonic acid metabolism in human colon mucosa and colon tumors, and this action may alter the risk for colon cancer in humans.

Life course impacts of parenting a child with a disability

We contrasted parents who had a child with a developmental disability, a serious mental health problem, and a normative comparison group with respect to parental attainment and well-being at mid-life. Data are from the Wisconsin Longitudinal Study, collected when the respondents were 18, 36, and 53 or 54, on average. Although similar at age 18, group patterns of attainment and well-being diverged thereafter. Parents of a child with a developmental disability had lower rates of employment, larger families, and lower rates of social participation but were similar to parents without a child with a disability in educational and marital status, physical health, and psychological well-being. Parents whose child had a serious mental health problem had normative patterns of educational and occupational attainment and marriage, but elevated levels of physical symptoms, depression, and alcohol symptoms at mid-life.

A repertoire of novel antibacterial diastereomeric peptides with selective cytolytic activity

The increase in infectious diseases and bacterial resistance to antibiotics has resulted in intensive studies focusing on the use of linear, alpha-helical, cytolytic peptides from insects and mammals as potential drugs for new target sites in bacteria. Recent studies with diastereomers of the highly potent cytolytic peptides, pardaxin and melittin, indicate that alpha-helical structure is required for mammalian cells lysis but is not necessary for antibacterial activity. Thus, hydrophobicity and net positive charge of the polypeptide might confer selective antibacterial lytic activity. To test this hypothesis, a series of diastereomeric model peptides (12 amino acids long) composed of varying ratios of leucine and lysine were synthesized, and their structure and biological function were investigated. Peptide length and the position of D-amino acids were such that short peptides with stretches of only 1-3 consecutive L-amino acids that cannot form an alpha-helical structure were constructed. Circular dichroism spectroscopy showed that the peptides do not retain any detectable secondary structure in a hydrophobic environment. This enabled examination of the sole effect of hydrophobicity and positive charge on activity. The data reveal that modulating hydrophobicity and positive charge is sufficient to confer antibacterial activity and cell selectivity. A highly hydrophobic diastereomer that permeated both zwitterionic and negatively charged phospholipid vesicles, lysed eukaryotic and prokaryotic cells. In contrast, a highly positively charged diastereomer that only permeated slightly negatively charged phospholipid vesicles had low antibacterial activity and could not lyse eukaryotic cells. In the boundary between high hydrophobicity and high positive charge, the diastereomers acquired selective and potent antibacterial activity. Furthermore, they were completely resistant to human serum inactivation, which dramatically reduces the activity of native antibacterial peptides. In addition, a strong synergistic effect was observed at nonlethal concentrations of the peptides with the antibiotic tetracycline on resistant bacteria. The results are discussed in terms of proposed mechanisms of antibacterial activity, as well as a new strategy for the design of a repertoire of short, simple, and easily manipulated antibacterial peptides as potential drugs in the treatment of infectious diseases.

Plasma and tissue levels of tea catechins in rats and mice during chronic consumption of green tea polyphenols

To understand the relationship between tea consumption and its biological effects, plasma and tissue levels of (-)-epigallocatechin-3-gallate (EGCG), (-)-epigallocatechin (EGC), and (-)-epicatechin (EC) were measured after rats and mice were given a 0.6% green tea polyphenol preparation as the drinking fluid for different periods of time. EGC and EC levels in rat plasma increased over time and reached peak values (3 times the Day 1 values) on Day 14. Then the plasma levels of tea catechins decreased, to Day 1 values on Day 28. The plasma concentrations of EGCG were much lower than those of EGC or EC. High levels of EGC and EC were found in urine, whereas high levels of EGCG were found in feces. The changes in the urinary and fecal excretions of tea catechins could not account for the above-described changes in the plasma levels. The amounts of catechins in different tissues reflected the ingestion, absorption, and excretion pattern. When the green tea polyphenol preparation was given to mice, the "increase-and-then-decrease" pattern of catechin levels was also observed in the plasma, lung, and liver; the EGCG levels were much higher than in the rats. The results suggest that consumption of tea by rodents could induce adaptive responses affecting blood and tissue levels of tea catechins with time and that investigation of a similar phenomenon in humans is warranted.

The role of percutaneous angioplasty in the management of chronic hemodialysis fistulas

One hundred forty-one dilatations of stenotic lesions in dialysis access fistulas were performed. The initial success rate was 82%. The one-year patency rate was 45%, with a 2-year patency rate of 24%. Best results were obtained with a discrete stenosis at a graft-to-vein anastomosis. The procedure can be done on an outpatient basis and, although long-term results are poor, in appropriate patients multiple dilatations can be performed to keep a fistula functioning for many years.

Oestrogen alters adipocyte biology and protects female mice from adipocyte inflammation and insulin resistance

AIMS

Obesity is associated with insulin resistance, liver steatosis and low-grade inflammation. The role of oestrogen in sex differences in the above co-morbidities is not fully understood. Our aim was to assess the role oestrogen has in modulating adipocyte size, adipose tissue oxidative stress, inflammation, insulin resistance and liver steatosis.

METHODS

To determine the role oestrogen has in the above co-morbidities related to obesity, we randomized C57BL/6J mice into four groups (15 mice per group): (i) male, (ii) non-ovariectomized female (novx), (iii) ovariectomized female (ovx) and (iv) ovariectomized female mice supplemented with 17β estradiol (ovx-E). Mice received either a low-fat (LF) or a high-fat (HF) diet for 10 weeks. Outcomes measured were bodyweight, body fat, adipocyte diameter, adipose tissue lipolysis markers, adipose tissue oxidative stress, inflammation, insulin resistance and liver steatosis.

RESULTS

Male and ovx-female mice consuming the HF diet had a higher propensity of gaining weight, specifically in the form of body fat. Oestrogen protected female mice from adipocyte hypertrophy and from developing adipose tissue oxidative stress and inflammation. Moreover, novx-female and ovx-female+E mice had higher phosphorylated levels of protein kinase A and hormone sensitive lipase, markers associated with lipolysis. Additionally, male and ovx female mice had a higher propensity of developing liver steatosis and insulin resistance. In contrast, oestrogen protected female mice from developing liver steatosis and from becoming insulin resistant.

CONCLUSION

We show that oestrogen protects female mice from adipocyte hypertrophy and adipose tissue oxidative stress and inflammation. Furthermore, oestrogen prevented female mice from developing liver steatosis and from becoming insulin resistant.

Asymmetric total synthesis of ent-(-)-roseophilin: assignment of absolute configuration

An asymmetric total synthesis of ent-(-)-roseophilin (1), the unnatural enantiomer of a novel naturally occurring antitumor antibiotic, is described. The approach enlists a room temperature heterocyclic azadiene inverse electron demand Diels-Alder reaction of dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate (7) with the optically active enol ether 6 bearing the C23 chiral center followed by a reductive ring contraction reaction for formation of an appropriately functionalized pyrrole ring in a key 1,2,4,5-tetrazine --> 1,2-diazine --> pyrrole reaction sequence. A Grubbs' ring closing metathesis reaction was utilized to close the unusual 13-membered macrocycle prior to a subsequent 5-exo-trig acyl radical-alkene cyclization that was used to introduce the fused cyclopentanone and complete the preparation of the tricylic ansa-bridged azafulvene core 32. Condensation of 32 with 33 under the modified conditions of Tius and Harrington followed by final deprotection provided (22S,23S)-1. Comparison of synthetic (22S,23S)-1 ([alpha](25)(D), CD) with natural 1 established that they were enantiomers and enabled the assignment of the absolute stereochemistry of the natural product as 22R,23R. Surprisingly, ent-(-)-1 was found to be 2-10-fold more potent than natural (+)-1 in cytotoxic assays, providing an unusually rewarding culmination to synthetic efforts that provided the unnatural enantiomer.

An ultrasound-driven needle-insertion robot for percutaneous cholecystostomy

A real-time ultrasound-guided needle-insertion medical robot for percutaneous cholecystostomy has been developed. Image-guided interventions have become widely accepted because they are consistent with minimal invasiveness. However, organ or abnormality displacement due to involuntary patient motion may undesirably affect the intervention. The proposed instrument uses intraoperative images and modifies the needle path in real time by using a novel ultrasonic image segmentation technique. In phantom and volunteer experiments, the needle path updating time was 130 and 301 ms per cycle, respectively. In animal experiments, the needle could be placed accurately in the target.

Long-term follow up on recurrence of 305 ameloblastoma cases

The aim of this study was to determine the appropriate treatment for ameloblastoma by considering the factors associated with recurrence, and to make a quantitative prediction of the risk factors for recurrence. Data on age and gender distribution, location of the tumour, histopathological findings, treatment method, and whether or not patients had a preoperative biopsy confirmation report were collected in 305 cases (239 patients; M: 139, F: 100) of ameloblastoma diagnosed and treated in 1985-2002. After initial statistical evaluation (chi(2)-test and Fisher's exact test), logistic regression analysis was performed to check relative significance and predict recurrence. The disease-free survival function curves of the patients with or without recurrence were obtained by the Kaplan-Meier method and compared using univariate regression analysis. The correlation between recurrence and the treatment method or histopathological type was significant. The differences between the 'conservative' and 'resection with bone margin' and between the 'conservative' and 'segmental resection or maxillectomy' groups in terms of disease-free survival were highly significant. The difference between the 'resection with bone margin' and 'segmental resection or maxillectomy' groups was not significant. A resection with safety margin is the best method to treat most proven ameloblastomas, and conservative treatment is reasonable for patients in their first decade or with unicystic or plexiform ameloblastoma.

Axillary and subclavian vein stenosis: percutaneous angioplasty

Twenty-nine percutaneous balloon dilations of the axillary and subclavian veins were performed in 19 patients. Stenoses occurred in typical locations of anatomic narrowing or at sites of previous trauma. The initial success rate was 76%, with a 1-year patency rate of 35% and a 2-year patency rate of 6%. Angioplasty can be performed on an outpatient basis with a very low rate of significant complications and can be repeated numerous times to keep a vein patent for many years. This procedure is especially valuable in dialysis patients who have limited access sites.

Structures and related properties of AgX bearing 3,3'-thiobispyridine (X- = NO3-, BF4-, CLO4-, and PF6-

Infinite molecular helices [Ag(3,3'-Py2S)]X (3,3'-Py2S = 3,3'-thiobispyridine; X- = BF4-, ClO4-, and PF6-) have been rationally constructed or induced. Crystallographic characterization (X- = BF-, monoclinic P2(1)/n, a = 8.946(3) A, b = 14.130(2) A, c = 10.124(2) A, beta = 107.83(2) degrees, V = 1218.3(5) A3, Z = 4, R = 0.0351; X- = ClO4-, monoclinic P2(1)/n, a = 8.884(1) A, b = 14.305(3) A, c = 10.110(1) A, beta = 106.78(1) degrees, V = 1230.1(3) A3, Z = 4, R = 0.0417; X- = PF6-, monoclinic P2(1)/c, a = 10.959(2) A, b = 9.808(2) A, c = 14.065(3) A, beta = 112.03(2) degrees, V = 1401.4(5) A3, Z = 4, R = 0.0442) reveals that the skeletal structure is an oblong cylindrical cationic helix consisting of alternating Ag(I) and 3,3'-Py2S species and that its counteranions are pinched in two columns inside each helix. The formation of the helical coordination polymer appears to be primarily associated with a suitable combination of the skewed conformer of 3,3'-Py2S and the potential linear geometry of the N-Ag(I)-N bond. However, the framework of the nitrate analogue [Ag(3,3'-Py2S)NO3] (monoclinic P2(1)/c, a = 8.177(2) A, b = 10.291(1) A, c = 14.771(2) A, beta = 102.19(1) degrees, V = 1214.9(4) A3, Z = 4, R = 0.0300) is a two-dimensional network consisting of an 18-membered ring unit, where each 3,3'-Py2S acts as a N,N',S- tridentate ligand connecting three tetrahedral silver(I) ions with the monodentate nitrate weakly bonded to the silver (Ag.O = 2.65(1) A) rather than acting as a counteranion. The anion exchange of [Ag(3,3'-Py2S)NO3] with BF4-, ClO4-, or PF6- has been accomplished in aqueous media. The two-dimensional networks are easily converted into the helices via the anion exchange, but the reverse anion exchange proceeds slightly. Thermal analyses indicate a relationship between the thermal stabilities and the structural properties.

Parathyroid hormone-related protein maintains mammary epithelial fate and triggers nipple skin differentiation during embryonic breast development

Prior reports have demonstrated that both parathyroid hormone-related protein (PTHrP) and the type I PTH/PTHrP receptor are necessary for the proper development of the embryonic mammary gland in mice. Using a combination of loss-of-function and gain-of-function models, we now report that PTHrP regulates a series of cell fate decisions that are central to the survival and morphogenesis of the mammary epithelium and the formation of the nipple. PTHrP is made in the epithelial cells of the mammary bud and, during embryonic mammary development, it interacts with the surrounding mesenchymal cells to induce the formation of the dense mammary mesenchyme. In response, these mammary-specific mesenchymal cells support the maintenance of mammary epithelial cell fate, trigger epithelial morphogenesis and induce the overlying epidermis to form the nipple. In the absence of PTHrP signaling, the mammary epithelial cells revert to an epidermal fate, no mammary ducts are formed and the nipple does not form. In the presence of diffuse epidermal PTHrP signaling, the ventral dermis is transformed into mammary mesenchyme and the entire ventral epidermis becomes nipple skin. These alterations in cell fate require that PTHrP be expressed during development and they require the presence of the PTH/PTHrP receptor. Finally, PTHrP signaling regulates the epidermal and mesenchymal expression of LEF1 and (β)-catenin, suggesting that these changes in cell fate involve an interaction between the PTHrP and Wnt signaling pathways.

A new in vitro model to study interaction between whole blood and biomaterials. Studies of platelet and coagulation activation and the effect of aspirin

We have developed a versatile in vitro chamber model with a double purpose: first, to be able to study mechanisms of bio-incompatibility, and, second, to test biomaterials at all levels of interactions, in whole blood. The use of biomaterials in the form of microscope slides as walls in the chamber makes it possible to analyse both the biomaterial surface with regard to protein and cell binding, as well as the molecular events taking place in the fluid. Incubation of blood in the chamber, for 60 min at 37 degrees C resulted in the rapid binding of complement and coagulation proteins and of leukocytes and platelets to polyvinylchloride (PVC) slides. The cells formed a layer which more or less covered the underlying surface. Unlike complement activation, as reflected by soluble C3a and C5b-9, the thrombin-antithrombin formation was completely nullified in cell-depleted plasma. Despite the fact that thrombin-antithrombin generation was also negligible in platelet-rich plasma, inhibition of platelet aggregation on the material surface with aspirin resulted in suppressed generation of thrombin antithrombin complexes. Taken together, the coagulation activation in the chamber was dependent on the presence of blood cells which suggests that bound/aggregated platelets initiate a sequence of events involving leukocytes that results in coagulation activation.

A novel long non-coding RNA ENST00000480739 suppresses tumour cell invasion by regulating OS-9 and HIF-1α in pancreatic ductal adenocarcinoma

BACKGROUND

Invasion and metastasis are the distinct biologic characteristics of cancer, resulting in an exceptionally low 5-year survival rate in pancreatic ductal adenocarcinoma (PDAC). Understanding in detail the mechanisms underlying PDAC metastasis is critical for prevention and effective interventions. Long non-coding RNAs (lncRNAs) have been documented as having a critical role in cancer development and progression.

METHODS

We examined the expression levels of lncRNA ENST00000480739 and osteosarcoma amplified-9 (OS-9) mRNA in a cohort of 35 PDAC patients. Cell proliferation, invasion and migration were examined with and without ENST00000480739 overexpression in PDAC cells.

RESULTS

We determined that the ENST00000480739 expression level was remarkably decreased in tumorous tissues compared with their corresponding non-tumorous tissues. The expression of ENST00000480739 was negatively associated with tumour node metastasis stage and lymph node metastasis. In addition, ENST0000048073 was an independent prognostic factor of survival time in PDAC patients following surgery. Besides, enforced expression of ENST00000480739 suppressed PDAC cells' invasion in vitro. Overexpression of ENST00000480739 significantly increased both mRNA and protein levels of OS-9, and the luciferase assays confirmed that ENST00000480739 positively regulates OS-9 by activating the transcription level of the OS-9 promoter. We further found that ENST00000480739 may target hypoxia-inducible factor-1α (HIF-1α) expression by upregulating OS-9.

CONCLUSIONS

These findings suggest that the frequently downregulated ENST00000480739 in PDAC contributes to tumour metastasis and progression by regulating HIF-1α. Long non-coding RNA ENST00000480739 may provide not only a therapeutic potential to suppress metastasis but it may also be a novel biomarker for risk prognostication and personal therapy screening of PDAC patients.