Restoration of coastal habitats: expectation and reality

Restoration today must satisfy a wide array of societal goals. In the past, success or failure of a project was dependent on minimal, measurable criteria. Simplistic designs and compliance criteria are being replaced by technically sophisticated projects and design goals that have variable criteria for success. Instead of a being static target, success criteria can be altered through a process termed Adaptive Management. Natural resource damage can be assessed accurately through a Habitat Equivalency Analysis. Acceptable progress toward compliance criteria is best measured by trends approaching a desired end point. An approach using natural variation of similar habitats also shows promise as a means of assessing compliance. Large-scale restoration projects are underway, directly and indirectly underwritten by the public. If the public is to continue support for restoration it must be a part of the decision-making process. This can be best accomplished through landscape management plans with clear objectives and goals that the public understands and that benefit the public at large. Technical problems in accomplishing and evaluating restoration projects will be solved if the experience gained at each site is used in future projects.     

Animal models of age related macular degeneration

Age related macular degeneration (AMD) is the leading cause of vision loss of those over the age of 65 in the industrialized world. The prevalence and need to develop effective treatments for AMD has lead to the development of multiple animal models. AMD is a complex and heterogeneous disease that involves the interaction of both genetic and environmental factors with the unique anatomy of the human macula. Models in mice, rats, rabbits, pigs and non-human primates have recreated many of the histological features of AMD and provided much insight into the underlying pathological mechanisms of this disease. In spite of the large number of models developed, no one model yet recapitulates all of the features of human AMD. However, these models have helped reveal the roles of chronic oxidative damage, inflammation and immune dysregulation, and lipid metabolism in the development of AMD. Models for induced choroidal neovascularization have served as the backbone for testing new therapies. This article will review the diversity of animal models that exist for AMD as well as their strengths and limitations.     

Microbial community analyses of produced waters from high‐temperature oil reservoirs reveal unexpected similarity between geographically distant oil reservoirs

As a preliminary investigation for the development of microbial‐enhanced oil recovery strategies for high‐temperature oil reservoirs (~70 to 90°C), we have investigated the indigenous microbial community compositions of produced waters from five different high‐temperature oil reservoirs near Segno, Texas, U.S. (~80 to 85°C) and Crossfield, Alberta, Canada (~75°C). The DNA extracted from these low‐biomass‐produced water samples were analysed with MiSeq amplicon sequencing of partial 16S rRNA genes. These sequences were analysed along with additional sequence data sets available from existing databases. Despite the geographical distance and difference in the physicochemical properties, the microbial compositions of the Segno and Crossfield produced waters exhibited unexpectedly high similarity, as indicated by the results of beta diversity analyses. The major operational taxonomic units included acetoclastic and hydrogenotrophic methanogens (Methanosaetaceae, Methanobacterium and Methanoculleus), as well as bacteria belonging to the families Clostridiaceae and Thermotogaceae, which have been recognized to include thermophilic, thermotolerant, and/or spore‐forming subtaxa. The sequence data retrieved from the databases exhibited different clustering patterns, as the communities from close geographical locations invariably had low beta diversity and the physicochemical properties and conditions of the reservoirs apparently did not have a substantial role in shaping of microbial communities.     

Discrete proteolysis of neuronal calcium sensor-1 (NCS-1) by μ-calpain disrupts calcium binding

Neuronal calcium sensor-1 (NCS-1) is a high-affinity, low-capacity Ca²⁺-binding protein expressed in many cell types. We previously showed that NCS-1 interacts with inositol 1,4,5-trisphosphate receptor (InsP₃R) and modulates Ca²⁺-signaling by enhancing InsP3-dependent InsP₃R channel activity and intracellular Ca²⁺ transients. Recently we reported that the chemotherapeutic agent, paclitaxel (taxol) triggers μ-calpain dependent proteolysis of NCS-1, leading to reduced Ca²⁺-signaling within the cell. Degradation of NCS-1 may be critical in the induction of peripheral neuropathy associated with taxol treatment for breast and ovarian cancer. To begin to design strategies to protect NCS-1, we treated NCS-1 with μ-calpain in vitro and identified the cleavage site by N-terminal sequencing and MALDI mass spectroscopy. μ-Calpain cleavage of NCS-1 occurs within an N-terminal pseudoEF-hand domain, which by sequence analysis appears to be unable to bind Ca²⁺. Our results suggest a role for this pseudoEF-hand in stabilizing the three functional EF-hands within NCS-1. Using isothermal titration calorimetry (ITC) we found that loss of the pseudoEF-hand markedly decreased NCS-1's affinity for Ca²⁺. Physiologically, this significant decrease in Ca²⁺ affinity may render NCS-1 incapable of responding to changes in Ca²⁺ levels in vivo. The reduced ability of μ-calpain treated NCS-1 to bind Ca²⁺ may explain the altered Ca²⁺ signaling in the presence of taxol and suggests a strategy for therapeutic intervention of peripheral neuropathy in cancer patients undergoing taxol treatment.     

Alzheimer's Therapeutics Targeting Amyloid Beta 1–42 Oligomers II: Sigma-2/PGRMC1 Receptors Mediate Abeta 42 Oligomer Binding and Synaptotoxicity

Amyloid beta (Abeta) 1–42 oligomers accumulate in brains of patients with Mild Cognitive Impairment (MCI) and disrupt synaptic plasticity processes that underlie memory formation. Synaptic binding of Abeta oligomers to several putative receptor proteins is reported to inhibit long-term potentiation, affect membrane trafficking and induce reversible spine loss in neurons, leading to impaired cognitive performance and ultimately to anterograde amnesia in the early stages of Alzheimer''s disease (AD). We have identified a receptor not previously associated with AD that mediates the binding of Abeta oligomers to neurons, and describe novel therapeutic antagonists of this receptor capable of blocking Abeta toxic effects on synapses in vitro and cognitive deficits in vivo. Knockdown of sigma-2/PGRMC1 (progesterone receptor membrane component 1) protein expression in vitro using siRNA results in a highly correlated reduction in binding of exogenous Abeta oligomers to neurons of more than 90%. Expression of sigma-2/PGRMC1 is upregulated in vitro by treatment with Abeta oligomers, and is dysregulated in Alzheimer''s disease patients'' brain compared to age-matched, normal individuals. Specific, high affinity small molecule receptor antagonists and antibodies raised against specific regions on this receptor can displace synthetic Abeta oligomer binding to synaptic puncta in vitro and displace endogenous human AD patient oligomers from brain tissue sections in a dose-dependent manner. These receptor antagonists prevent and reverse the effects of Abeta oligomers on membrane trafficking and synapse loss in vitro and cognitive deficits in AD mouse models. These findings suggest sigma-2/PGRMC1 receptors mediate saturable oligomer binding to synaptic puncta on neurons and that brain penetrant, small molecules can displace endogenous and synthetic oligomers and improve cognitive deficits in AD models. We propose that sigma-2/PGRMC1 is a key mediator of the pathological effects of Abeta oligomers in AD and is a tractable target for small molecule disease-modifying therapeutics.     

Analysis of oocyte physiology to improve cryopreservation procedures

In contrast to the preimplantation mammalian embryo, it has been notoriously difficult to cryopreserve the metaphase II oocyte. The ability to store oocytes successfully at -196 degrees C has numerous practical and financial advantages, together with ethical considerations, and will positively impact animal breeding programs and assisted conception in the human. Differences in membrane permeability and in physiology are two main reasons why successful oocyte cryopreservation has remained elusive. It is proposed, therefore, that rather than relying on technologies already established for the preimplantation embryo, the development of cryopreservation techniques suitable for the mammalian oocyte needs to take into account the idiosyncratic physiology of this cell. Analysis of intracellular calcium, for example, has revealed that exposure to conventional permeating cryoprotectants, such as propanediol, ethylene glycol and DMSO, all independently result in an increase in calcium, which in turn has the potential to initiate oocyte activation, culminating in zona hardening. Quantification of the metabolome and proteome of the oocyte has revealed that whereas slow freezing has a dramatic effect on cell physiology, vitrification appears to have limited effect. This is plausibly achieved by the limited exposure to cryoprotectants. Analysis of meiotic spindle dynamics and embryo development following IVF, also indicate that vitrification is less traumatic than slow freezing, and therefore has the greatest potential for successful oocyte cryopreservation.     

Coupled mRNA stabilization and translational silencing of cyclooxygenase-2 by a novel RNA binding protein,CUGBP2

Cyclooxygenase-2 (COX-2) expression is translationally silenced in epithelial cells undergoing radiation-induced apoptosis. CUGBP2, a predominantly nuclear protein, is also rapidly induced in response to radiation and translocates to the cytoplasm. Antisense-mediated suppression of CUGBP2 renders radioprotection through a COX-2-dependent prostaglandin pathway, providing an in vivo demonstration of translation inhibition activity for CUGBP2. CUGBP2 binds to two sets of AU-rich sequences (AREs) located within the first sixty nucleotides of the COX-2 3' untranslated region (3'UTR). Upon binding, CUGBP2 stabilizes a chimeric luciferase-COX-2 3'UTR mRNA but inhibits its translation. These findings identify a novel paradigm for RNA binding proteins in facilitating opposing functions of mRNA stability and translation inhibition and reveal a mechanism for inhibiting COX-2 expression in cancer cells.