Palmitate and group B Streptococcus synergistically and differentially induce IL-1β from human gestational membranes

IntroductionRupture of the gestational membranes often precedes major pregnancy complications, including preterm labor and preterm birth. One major cause of inflammation in the gestational membranes, chorioamnionitis (CAM) is often a result of bacterial infection. The commensal bacterium Streptococcus agalactiae, or Group B Streptococcus (GBS) is a leading infectious cause of CAM. Obesity is on the rise worldwide and roughly 1 in 4 pregnancy complications is related to obesity, and individuals with obesity are also more likely to be colonized by GBS. The gestational membranes are comprised of several distinct cell layers which are, from outermost to innermost: maternally-derived decidual stromal cells (DSCs), fetal cytotrophoblasts (CTBs), fetal mesenchymal cells, and fetal amnion epithelial cells (AECs). In addition, the gestational membranes have several immune cell populations; macrophages are the most common phagocyte. Here we characterize the effects of palmitate, the most common long-chain saturated fatty acid, on the inflammatory response of each layer of the gestational membranes when infected with GBS, using human cell lines and primary human tissue.ResultsPalmitate itself slightly but significantly augments GBS proliferation. Palmitate and GBS co-stimulation synergized to induce many inflammatory proteins and cytokines, particularly IL-1β and matrix metalloproteinase 9 from DSCs, CTBs, and macrophages, but not from AECs. Many of these findings are recapitulated when treating cells with palmitate and a TLR2 or TLR4 agonist, suggesting broad applicability of palmitate-pathogen synergy. Co-culture of macrophages with DSCs or CTBs, upon co-stimulation with GBS and palmitate, resulted in increased inflammatory responses, contrary to previous work in the absence of palmitate. In whole gestational membrane biopsies, the amnion layer appeared to dampen immune responses from the DSC and CTB layers (the choriodecidua) to GBS and palmitate co-stimulation. Addition of the monounsaturated fatty acid oleate, the most abundant monounsaturated fatty acid in circulation, dampened the proinflammatory effect of palmitate.DiscussionThese studies reveal a complex interplay between the immunological response of the distinct layers of the gestational membrane to GBS infection and that such responses can be altered by exposure to long-chain saturated fatty acids. These data provide insight into how metabolic syndromes such as obesity might contribute to an increased risk for GBS disease during pregnancy

The Effects of Cholera Toxin on Cellular Energy Metabolism

Multianalyte microphysiometry, a real-time instrument for simultaneous measurement of metabolic analytes in a microfluidic environment, was used to explore the effects of cholera toxin (CTx). Upon exposure of CTx to PC-12 cells, anaerobic respiration was triggered, measured as increases in acid and lactate production and a decrease in the oxygen uptake. We believe the responses observed are due to a CTx-induced activation of adenylate cyclase, increasing cAMP production and resulting in a switch to anaerobic respiration. Inhibitors (H-89, brefeldin A) and stimulators (forskolin) of cAMP were employed to modulate the CTx-induced cAMP responses. The results of this study show the utility of multianalyte microphysiometry to quantitatively determine the dynamic metabolic effects of toxins and affected pathways

Graduate Electrochemistry Course Projects

Electrochemistry as a discipline is taught comprehensively as a graduate course throughout the United States. With the increasing movement towards active learning environments in classrooms, this talk will highlighted several past and current models of including laboratory and computational components to augment the classical lecture format in the graduate electrochemistry course and a related advanced analytical sensors course. Significant challenges occur in “flipping the classroom” or other in vogue “SCALEUP” course models when a working knowledge of the field is very difficult to obtain from reading even the most accepted texts. Hybrid models incorporating out of class projects have been adapted to increase the relevance of the field to particular students while building up a working knowledge and experimental experience. The nature of these projects has shifted over the years to specific assignments to independently designed projects to team projects and back to individual ideas plus team help. </jats:p

Bringing Multianalyte Electrochemistry to Pharma

Abstract not Available.</jats:p

Interfacing Photosystem I into Conducting Polymers

Photosystem I (PSI) is one of the primary macromolecular machines that drive photosynthesis in green plants and cyanobacteria. Extracted PSI has been employed successfully as a macromolecular photosensitizer within a host of low-cost electrochemical and solid-state photovoltaic architectures. Over the course of the last ten years, our group has worked on the electrochemical interfaces to incorporate photosystem I in applied photosynthetic systems, and has created a wealth of new approaches in terms of both solid photovoltaic cells, liquid photoelectrochemical cells, and hydrogen fuel generation. These approaches have resulted in numerous publications. Using photosystem I as the key active component, we have been leading an effort to integrate PSI into biomimetic photoelectrochemical cells and devices. For example, we developed a completely organic, transparent, conductive electrode using reduced graphene oxide (RGO) on which a multilayer of PSI could be deposited. This presentation will also explore our group’s recent efforts to integrate PSI with advanced materials, including the conducting polymers polyaniline (PANI), polypyrrole, polyviologens, and poly(3,4-ethylenedioxythiophene). These composite assemblies enhance charge shuttling processes from individual proteins within multilayer assemblies—greatly reducing charge transfer resistances and improving overall efficiency of photocells. These PSI/conducting polymer composites can be prepared by either electrochemical co-polymerization from a bath of PSI and aniline or a vapor-phase Friedel-Crafts grafting procedure. The group has reported two new prototype solid-state devices in which PSI or PSI/PANI is sandwiched between energetically appropriate electrodes. The group has also succeeded in stabilizing PSI films via crosslinking to create “wet” photoelectrochemical cells with greater performance and longevity. Finally, our current work is aimed at building new prototypes using PSI in solid state interfaces for scalable solar energy conversion. Finally, the incorporation of PSI into conducting polymer frameworks holds promise for improved conductivity and orientational control in the photoactive layers in these devices. </jats:p

Simultaneous Optical and Electrochemical Imaging of Shewanella Oneidensis

Shewanella oneidensis is an electroactive bacterium that has the ability to harvest electrons from insoluble metals in its environment for biological processes via dissimilatory metal reduction (DMR). There are 4 mechanisms by which S. oneidensis accomplishes these reductions: direct contact of the outer cell membrane to the metals, protein “nanowires” that extend from the cell surface, metal chelators that solubilize the metals, and small molecule electron shuttles. While evidence suggests S. oneidensis predominately utilizes soluble electron shuttles for DMR, it has yet to be directly proven. If the exact mechanism or mechanisms could be elucidated, S. oneidensis could be employed in a fuel cell that rids polluted water of metal contaminants in the process of generating electricity. For this research, scanning electrochemical microscopy (SECM) was used to investigate the DMR processes of S. oneidensis. By coupling SECM to an inverted microscope, we optically imaged the bacteria during two-dimensional electrochemical measurements. Combined with advances in carbon ultra-micro electrode fabrication, this optical-SECM was used for high resolution scans of S. oneidensis biofilms, as well as planktonic bacteria. </jats:p