Norepinephrine acts as D1-dopaminergic agonist in the embryonic avian retina: late expression of beta1-adrenergic receptor shifts norepinephrine specificity in the adult tissue

Dopamine is the main catecholamine found in the chick retina whereas norepinephrine is only found in trace amounts. We compared the effectiveness of dopamine and norepinephrine in promoting cyclic AMP accumulation in retinas at embryonic day 13 (E13) and from post-hatched chicken (P15). Dopamine (EC(50)=10microM) and norepinephrine (EC(50)=30microM), but not the beta(1)-adrenergic agonist isoproterenol, stimulated over seven-fold the production of cyclic AMP in E13 retina. The cyclic AMP accumulation induced by both catecholamines in embryonic tissue was entirely blocked by 2microM SCH23390, a D(1) receptor antagonist, but not by alprenolol (beta-adrenoceptor antagonist). In P15 retinas, 100microM isoproterenol stimulated five-fold the accumulation of cAMP. This effect was blocked by propanolol (10microM), but not by 2microM SCH23390. Embryonic and adult retina display beta(1) adrenergic receptor mRNA as detected by RT-PCR, but the beta(1) adrenergic receptor protein was detected only in post-hatched tissue. We conclude that norepinephrine cross-reacts with D(1) dopaminergic receptor with affinity similar to that of dopamine in the embryonic retina. In the mature retina, however, D(1) receptors become restricted to activation by dopamine. Moreover, as opposed to the embryonic tissue, norepinephrine seems to stimulate cAMP accumulation via beta(1)-like adrenergic receptors in the mature tissue.     

Preemptive heme oxygenase-1 gene delivery reveals reduced mortality and preservation of left ventricular function 1 yr after acute myocardial infarction

We reported previously that predelivery of heme oxygenase-1 (HO-1) gene to the heart by adeno-associated virus-2 (AAV-2) markedly reduces ischemia and reperfusion (I/R)-induced myocardial injury. However, the effect of preemptive HO-1 gene delivery on long-term survival and prevention of postinfarction heart failure has not been determined. We assessed the effect of HO-1 gene delivery on long-term survival, myocardial function, and left ventricular (LV) remodeling 1 yr after myocardial infarction (MI) using echocardiographic imaging, pressure-volume (PV) analysis, and histomorphometric approaches. Two groups of Lewis rats were injected with 2 x 10(11) particles of AAV-LacZ (control) or AAV-human HO-1 (hHO-1) in the anterior-posterior apical region of the LV wall. Six weeks after gene transfer, animals were subjected to 30 min of ischemia by ligation of the left anterior descending artery followed by reperfusion. Echocardiographic measurements and PV analysis of LV function were obtained at 2 wk and 12 mo after I/R. One year after acute MI, mortality was markedly reduced in the HO-1-treated animals compared with the LacZ-treated animals. PV analysis demonstrated significantly enhanced LV developed pressure, elevated maximal dP/dt, and lower end-diastolic volume in the HO-1 animals compared with the LacZ animals. Echocardiography showed a larger apical anterior-to-posterior wall ratio in HO-1 animals compared with LacZ animals. Morphometric analysis revealed extensive myocardial scarring and fibrosis in the infarcted LV area of LacZ animals, which was reduced by 62% in HO-1 animals. These results suggest that preemptive HO-1 gene delivery may be useful as a therapeutic strategy to reduce post-MI LV remodeling and heart failure.     

How to address CPP and AMP translocation? Methods to detect and quantify peptide internalization in vitro and in vivo (Review)

Membrane translocation is a crucial issue when addressing the activity of both cell-penetrating and antimicrobial peptides. Translocation is responsible for the therapeutic potential of cell-penetrating peptides as drug carriers and can dictate the killing mechanisms, selectivity and efficiency of antimicrobial peptides. It is essential to evaluate if the internalization of cell-penetrating peptides is mediated by endocytosis and if it is able to internalize attached cargoes. The mode of action of an antimicrobial peptide cannot be fully understood if it is not known whether the peptide acts exclusively at the membrane level or also at the cytoplasm. Therefore, experimental methods to evaluate and quantify translocation processes are of first importance. In this work, over 20 methods described in the literature for the assessment of peptide translocation in vivo and in vitro, with and without attached macromolecular cargoes, are discussed and their applicability, advantages and disadvantages reviewed. In addition, a classification of these methods is proposed, based on common approaches to detect translocation.     

The use of isobaric tag peptide labeling (iTRAQ) and mass spectrometry to examine rare,primitive hematopoietic cells from patients with chronic myeloid leukemia

Chronic Myeloid Leukemia (CML) is a hematopoietic stem cell disease, associated with a t(9, 22) chromosomal translocation leading to formation of the BCR/ABL chimeric protein, which has an intrinsic tyrosine kinase activity. Recently, the BCR/ABL tyrosine kinase inhibitor imatinib mesylate (imatinib) has been successfully used clinically, although, disease relapse can still occur. The precise detail of the mechanism by which CML cells respond to imatinib is still unclear. We therefore systematically examined the effects of imatinib on the primitive CML cell proteome, having first established that the drug inhibits proliferation and induces increased apoptosis and differentiation. To define imatinib-induced effects on the CML proteome, we employed isobaric tag peptide labeling (iTRAQ) coupled to two-dimensional liquid chromatography/tandem mass spectrometry. Given the limited clinical material available, the isobaric tag approach identified a large population of proteins and provided relative quantification on four samples at once. Novel consequences of the action of imatinib were identified using this mass spectrometric approach. DEAD-box protein 3, heat shock protein 105 kDa, and peroxiredoxin-3 were identified as potential protein markers for response to imatinib. Electronic Supplementary Material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. Stephen D. Griffiths and John Burthem contributed equally to this publication. This work is supported by The Leukaemia Research Fund (UK).     

Vogtnema asymmetrica n. gen., n. sp. (Nematoda: Cosmocercoidea: Atractidae) parasite of Rhinoclemmys punctularia (Daudin) (Testudines: Geoemydidae) from eastern Amazon,Brazil

Systematic Parasitology - Nematodes collected from the stomach and large intestine of Rhinoclemmys punctularia (Daudin) from the eastern Amazon, Brazil, are assigned to a new genus, Vogtnema n....     

An overview of malaria transmission from the perspective of Amazon Anopheles vectors

In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.