Protective Effects of Valproic Acid,a Histone Deacetylase Inhibitor,against Hyperoxic Lung Injury in a Neonatal Rat Model

ObjectiveHistone acetylation and deacetylation may play a role in the pathogenesis of inflammatory lung diseases. We evaluated the preventive effect of valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, on neonatal hyperoxic lung injury.MethodsForty newborn rat pups were randomized in normoxia, normoxia+VPA, hyperoxia and hyperoxia+VPA groups. Pups in the normoxia and normoxia+VPA groups were kept in room air and received daily saline and VPA (30 mg/kg) injections, respectively, while those in hyperoxia and hyperoxia+VPA groups were exposed to 95% O₂ and received daily saline and VPA (30 mg/kg) injections for 10 days, respectively. Growth, histopathological, biochemical and molecular biological indicators of lung injury, apoptosis, inflammation, fibrosis and histone acetylation were evaluated.ResultsVPA treatment during hyperoxia significantly improved weight gain, histopathologic grade, radial alveolar count and lamellar body membrane protein expression, while it decreased number of TUNEL(+) cells and active Caspase-3 expression. Expressions of TGFβ3 and phospho-SMAD2 proteins and levels of tissue proinflammatory cytokines as well as lipid peroxidation biomarkers were reduced, while anti-oxidative enzyme activities were enhanced by VPA treatment. VPA administration also reduced HDAC activity while increasing acetylated H3 and H4 protein expressions.ConclusionsThe present study shows for the first time that VPA treatment ameliorates lung damage in a neonatal rat model of hyperoxic lung injury. The preventive effect of VPA involves HDAC inhibition.     

Serum paraoxonase level and paraoxonase polymorphism in patients with acromegaly

Background: Acromegalic patients have increased cardiometabolic risk factors due to an elevation of growth hormone (GH) levels. Human serum paraoxonase (PON), a high-density lipoprotein (HDL)-related enzyme, is one of the major bioscavengers and decreases the oxidation of low-density lipoprotein (LDL), a key regulator in the pathogenesis of atherosclerosis. In this study, we investigated a potential relationship between serum PON levels or PON polymorphisms and acromegaly.

Methods: A total of 48 acromegalic patients and 44 healthy controls were included in this study. Serum GH levels, insulin-like growth factor-1 levels and lipid profiles were measured. Serum PON levels, as well as PON 1 L55M and Q192R gene polymorphisms, were examined.

Results: No significant differences were found in terms of age, gender, presence of diabetes, serum LDL cholesterol (LDL-C), HDL-C, or triglyceride levels between the case and control groups (P?>?0.05). A statistically significant difference was found in serum PON levels between the cases and controls (P?=?0.007). The median serum PON level was 101?±?63.36?U/l in the case group and 63?±?60.50?U/l in the control group. There was a significant correlation between serum PON levels and IGF-1 levels (P?=?0.004, r?=?0.319); however, no significant differences were found in PON1 L55M and PON Q192R polymorphisms between the patients and controls (P?=?0.607 and P?=?0.308, respectively). In addition, no significant differences were found in serum PON levels in acromegalic patients who were and were not in remission (P?=?0.385), nor between those with PON1 L55M and Q192R polymorphisms (P?=?0.161 and P?=?0.336, respectively).

Conclusions: Elevated serum PON levels were detected in acromegalic patients, independently of their remission status. This suggests protective effects for cardiometabolic risk parameters.     

What do we know about mechanical strain in lung alveoli?

The pulmonary alveolus, terminal gas-exchange unit of the lung, is composed of alveolar epithelial and endothelial cells separated by a thin basement membrane and interstitial space. These cells participate in the maintenance of a delicate system regulated not only by biological factors but also by the mechanical environment of the lung, which undergoes dynamic deformation during breathing. Clinical and animal studies as well as cell culture studies point toward a strong influence of mechanical forces on lung cells and tissues including effects on growth and repair, surfactant release, injury, and inflammation. However, despite substantial advances in our understanding of lung mechanics over the last half century, there are still many unanswered questions regarding the micromechanics of the alveolus and how it deforms during lung inflation. Therefore, the aims of this review are to draw a multidisciplinary account of the mechanics of the alveolus on the basis of its structure, biology, and chemistry and to compare estimates of alveolar deformation from previous studies.     

Identification of CD44 as a surface biomarker for drug resistance by surface proteome signature technology

We developed surface proteome signatures (SPS) for identification of new biomarkers playing a role in cancer drug resistance. SPS compares surface antigen expression of different cell lines by immunocytochemistry of a phage display antibody library directed to surface antigens of HT1080 fibrosarcoma cells. We applied SPS to compare the surface proteomes of two epithelial derived cancer cell lines, MCF7 and NCI/ADR-RES, which is drug resistant because of overexpression of the P-glycoprotein (P-gp) drug efflux pump. Surface proteomic profiling identified CD44 as an additional biomarker that distinguishes between these two cell lines. CD44 immunohistochemistry can distinguish between tumors derived from these lines and predict tumor response to doxorubicin in vivo. We further show that CD44 plays a role in drug resistance, independently of P-gp, in NCI/ADR-RES cells and increases expression of the antiapoptotic protein Bcl-xL. Our findings illustrate the utility of SPS to distinguish between cancer cell lines and their derived tumors and identify novel biomarkers involved in drug resistance.     

132 Impact of sticky end length on the diffraction of self-assembled DNA crystals

Our laboratory has reported a self-assembled 3-D crystal based on a DNA tensegrity triangle. The tensegrity triangle is a rigid DNA motif with three-fold rotational symmetry consisting of three helices whose axes are directed along three linearly independent directions (1). The triangles form a crystalline lattice stabilized via sticky ends (2). The length of the sticky ends reported previously was two nucleotides (nt) GA:TC. Although diffracting to 4 Å resolution at the APS-ID19 beam line, they diffract only to 4.9 Å at the NSLS-X25 beam line. In the current study, we have analysed the effect of sticky end length and sequence on crystal formation and the resolution of the X-ray diffraction pattern on NSLS-X25. Tensegrity triangle motifs having 1-, 2-, and 3-nt sticky ends have all formed crystals. X-ray diffraction data from the same beam line revealed that the crystal resolution was somewhat better for the 2-nt sticky end having an AA:TT base pair (4.75 Å) than GA:CT and CC:GG (8.0 Å). Moreover, the 1-nt sticky end (C:G) yielded a diffraction pattern whose resolution (3.5 Å) compared favorably with all the three 2-nt sticky end systems. However, the triangle motif having a 1-nt sticky end with an A:T base pair did not yield any crystals. For motifs with 3-nt sticky ends, the sequence GAG:CTC produced small crystals (10–20?μm), while larger crystals (150?μm) were obtained with the sequences TAG:ATC and TAT:ATA. Our results indicate that not only do the lengths and sequences of the sticky ends define the interactions between motifs, but they also have an impact on the resulting resolution. We expect redesigned assemblies to form 3-D crystals with better resolution that can aid in the scaffolding of biological macromolecules for crystallographic structure determination. Applications in many areas of DNA nanotechnology are expected to benefit from a complete analysis of the effects of sticky end length, sequence, and free energy.     

Sympathetic Neurons Express and Secrete MMP-2 and MT1-MMP to Control Nerve Sprouting via Pro-NGF Conversion

Recently, we have shown that high frequency electrical field stimulation (HFES) of sympathetic neurons (SN) induces nerve sprouting by up-regulation of nerve growth factor (NGF) which targets the tyrosine kinase A receptor (TrkA) in an autocrine/paracrine manner. There is increasing evidence that matrix metalloproteinase-2 (MMP-2) is not only involved in extracellular matrix (ECM) turnover but may also exert beneficial effects during neuronal growth. Therefore, this study aimed to investigate the regulation and function of MMP-2 and its major activator membrane type 1-matrix metalloproteinase (MT1-MMP) as well its inhibitor TIMP-1 in SN under conditions of HFES. Moreover, we analyzed molecular mechanisms of the beneficial effect of losartan, an angiotensin II type I receptor (AT-1)blocker on HFES-induced nerve sprouting. Cell cultures of SN from the superior cervical ganglia (SCG) of neonatal rats were electrically stimulated for 48 h with a frequency of 5 or 50 Hz. HFES increased MMP-2 and MT1-MMP mRNA and protein expression, whereas TIMP-1 expression remained unchanged. Under conditions of HFES, we observed a shift from pro- to active-MMP-2 indicating an increase in MMP-2 enzyme activity. Specific pharmacological MMP-2 inhibition contributed to an increase in pro-NGF amount in the cell culture supernatant and significantly reduced HFES-induced neurite outgrowth. Losartan abolished HFES-induced nerve sprouting in a significant manner by preventing HFES-induced NGF, MMP-2, and MT1-MMP up-regulation. In summary, specific MMP-2 blockade prevents sympathetic nerve sprouting (SNS) by inhibition of pro-NGF conversion while losartan abolishes HFES-induced SNS by reducing total NGF, MMP-2 and MT1-MMP expression.     

Lisinopril attenuates renal oxidative injury in l-NAME-induced hypertensive rats

Genetic factors related to cancer have been extensively studied and several polymorphisms have been associated to breast cancer. The FGFR4, MTHFR, and HFE genes have been associated with neoplastic diseases development. The current report outlines the analysis of the polymorphisms G388A (FGFR4), C677T (MTHFR), C282Y, and H63D (HFE) in Brazilian breast cancer patients. We studied 68 patients with invasive ductal and operable breast carcinoma and 85 women as a control group. The polymorphism frequencies in the breast cancer and control groups were analyzed, but no significant difference was observed by comparing the two groups. The presence of each polymorphism was analyzed according to the clinical features and markers already established as prognostic in the breast cancer group. The C677T, H63D, and G388A polymorphisms were not associated to histological grade, age of diagnosis, expression of HER2 receptor, or estrogen and progesterone receptor. The H63D polymorphism showed a significant association (P = 0.02) with the presence of p53 mutations, and C667T showed association to lymph node involvement (P = 0.05). Lymph node involvement, G388A polymorphism, and histological grade were independently associated to metastasis/death. Our data suggests that the polymorphisms G388A, C677T, and H63D are not useful in breast cancer diagnosis, but they may be significant additional prognostic markers related to breast cancer survival.     

Bistability Analysis of an Apoptosis Model in the Presence of Nitric Oxide

Bistability in apoptosis, or programmed cell death, is crucial for the healthy functioning of multicellular organisms. The aim in this study is to show the presence of bistability in a mitochondria-dependent apoptosis model under nitric oxide effects using chemical reaction network theory. The model equations are a set of coupled ordinary differential equations arising from the assumed mass action kinetics. Whether these equations have a capacity for bistability (cell survival and apoptosis) is determined using a modular approach in which the model is decomposed into modules. Each module contains only a subset of the whole model and is analyzed separately. It is seen that bistability in a module is preserved throughout the whole model after adding the remaining reactions in the pathway on these modules. It is also found that inhibitor effect of some proteins and the appearance of a reacting protein in a later stage as a product is a desired feature but not sufficient for bistability (in the absence of cooperativity effects). On the whole model, two apoptotic and two cell survival states are obtained depending on the initial cell conditions. The results suggest that the antiapoptotic effects of nitric oxide species are responsible for the bistable character of the apoptotic pathway when cooperativity is not assumed in the apoptosome formation.