Stromelysin-1 Regulates Adipogenesis during Mammary Gland Involution

The matrix metalloproteinase MMP-3/stromelysin-1 (Str1) is highly expressed during mammary gland involution induced by weaning. During involution, programmed cell death of the secretory epithelium takes place concomitant with the repopulation of the mammary fat pad with adipocytes. In this study, we have used a genetic approach to determine the role of Str1 during mammary involution. Although Str1 has been shown to induce unscheduled apoptosis when expressed ectopically during late pregnancy (Alexander, C.M., E.W. Howard, M.J. Bissell, and Z. Werb. 1996. J. Cell Biol. 135:1669–1677), we found that during post-lactational involution, mammary glands from transgenic mice that overexpress the tissue inhibitor of metalloproteinases, TIMP-1 (TO), or mice carrying a targeted mutation in Str1 showed accelerated differentiation and hypertrophy of adipocytes, while epithelial apoptosis was unaffected. These data suggest that matrix metalloproteinases (MMPs) do not induce unscheduled epithelial cell death after weaning, but instead alter the stromal microenvironment. We used adipogenic 3T3-L1 cells as a cell culture model to test the function of MMPs during adipocyte differentiation. Fibroblastic 3T3-L1 progenitor cells expressed very low levels of MMPs or TIMPs. The transcription of a number of MMP and TIMP mRNAs [Str1, MT1-MMP, (MMP-14) collagenase-3 (MMP-13), gelatinase A (MMP-2), and TIMP-1, -2 and -3] was induced in committed preadipocytes, but only differentiated adipocytes expressed an activated MMP, gelatinase A. The addition of MMP inhibitors (GM 6001 and TIMP-1) dramatically accelerated the accumulation of lipid during differentiation. We conclude that MMPs, especially Str1, determine the rate of adipocyte differentiation during involutive mammary gland remodeling

International Space Station Potable Water Characterization for 2013

In this post-construction, operational phase of International Space Station (ISS) with an ever-increasing emphasis on its use as a test-bed for future exploration missions, the ISS crews continue to rely on water reclamation systems for the majority of their water needs. The onboard water supplies include U.S. Segment potable water from humidity condensate and urine, Russian Segment potable water from condensate, and ground-supplied potable water, as reserve. In 2013, the cargo returned on the Soyuz 32-35 flights included archival potable water samples collected from Expeditions 34-37. The former Water and Food Analytical Laboratory (now Toxicology and Evironmental Chemistry Laboratory) at the NASA Johnson Space Center continued its long-standing role of performing chemical analyses on ISS return water samples to verify compliance with potable water quality specifications. This paper presents and discusses the analytical results for potable water samples returned from Expeditions 34-37, including a comparison to ISS quality standards. During the summer of 2013, the U.S. Segment potable water experienced a third temporary rise and fall in total organic carbon (TOC) content, as the result of organic contamination breaking through the water system's treatment process. Analytical results for the Expedition 36 archival samples returned on Soyuz 34 confirmed that dimethylsilanediol was once again the responsible contaminant, just as it was for the previous comparable TOC rises in 2010 and 2012. Discussion herein includes the use of the in-flight total organic carbon analyzer (TOCA) as a key monitoring tool for tracking these TOC rises and scheduling appropriate remediation

International Space Station Potable Water Characterization for 2013

In this post-construction, operational phase of International Space Station (ISS) with an ever-increasing emphasis on its use as a test-bed for future exploration missions, the ISS crews continue to rely on water reclamation systems for the majority of their water needs. The onboard water supplies include US Segment potable water from humidity condensate and urine, Russian Segment potable water from condensate, and ground-supplied potable water, as reserve. In 2013, the cargo returned on the Soyuz 32-35 flights included archival potable water samples collected from Expeditions 34-37. The Water and Food Analytical Laboratory at the NASA Johnson Space Center continued its long-standing role of performing chemical analyses on ISS return water samples to verify compliance with potable water quality specifications. This paper presents and discusses the analytical results for potable water samples returned from Expeditions 34-37, including a comparison to ISS quality standards. During the summer of 2013, the U.S. Segment potable water experienced an anticipated temporary rise and fall in total organic carbon (TOC) content, as the result of organic contamination breaking through the water system's treatment process. Analytical results for the Expedition 36 archival samples returned on Soyuz 34 confirmed that dimethylsilanediol was once again the responsible contaminant, just as it was for comparable TOC rises in 2010 and 2012. Discussion herein includes the use of the in-flight Total Organic Carbon Analyzer (TOCA) as a key monitoring tool for tracking these TOC rises and scheduling appropriate remediation action

2014 ISS Potable Water Characterization and Continuation of the DMSD Chronicle

During 2014 the crews from Expeditions 38-41 were resident on the International Space Station (ISS). In addition to the U.S. potable water reclaimed from humidity condensate and urine, the other water supplies available for their use were Russian potable water reclaimed from condensate and Russian ground-supplied potable water. Beginning in June of 2014, and for the fourth time since 2010, the product water from the U.S. Water Processor Assembly (WPA) experienced a rise in the total organic carbon (TOC) level due to organic contaminants breaking through the water treatment process. Results from ground analyses of ISS archival water samples returned on Soyuz 38 confirmed that dimethylsilanediol (DMSD) was once again the contaminant responsible for the rise. With this confirmation in hand and based upon the low toxicity of DMSD, a waiver was approved to allow the crew to continue to consume the water after the TOC level exceeded the U.S. Segment limit of 3 mg/L. Several weeks after the WPA multifiltration beds were replaced, as anticipated based upon experience from previous rises, the TOC levels returned to below the method detection limit of the onboard TOC analyzer (TOCA). This paper presents and discusses the chemical analysis results for the ISS archival potable water samples returned in 2014 and analyzed by the Johnson Space Center's Toxicology and Environmental Chemistry laboratory. These results showed compliance with ISS potable water quality standards and indicated that the potable water supplies were acceptable for crew consumption. Although DMSD levels were at times elevated they remained well below the 35 mg/L health limit, so continued consumption of the U.S potable water was considered a low risk to crew health and safety. Excellent agreement between inflight and archival sample TOC data confirmed that the TOCA performed optimally and it continued to serve as a vital tool for monitoring organic breakthrough and planning remediation action

Application of Colorimetric Solid Phase Extraction (C-SPE) to Monitoring Nickel(II) and Lead(II) in Spacecraft Water Supplies

Archived water samples collected on the International Space Station (ISS) and returned to Earth for analysis have, in a few instances, contained trace levels of heavy metals. Building on our previous advances using Colorimetric Solid Phase Extraction (C-SPE) as a biocide monitoring technique, we are devising methods for the low level monitoring of nickel(II), lead(II) and other heavy metals. C-SPE is a sorption-spectrophotometric platform based on the extraction of analytes onto a membrane impregnated with a colorimetric reagent that are then quantified on the surface of the membrane using a diffuse reflectance spectrophotometer. Along these lines, we have determined nickel(II) via complexation with dimethylglyoxime (DMG) and begun to examine the analysis of lead(II) by its reaction with 2,5- dimercapto-1,3,4-thiadiazole (DMTD) and 4-(2- pyridylazo)-resorcinol (PAR). These developments are also extending a new variant of C-SPE in which immobilized reagents are being incorporated into this methodology in order to optimize sample reaction conditions and to introduce the colorimetric reagent. This paper describes the status of our development of these two new methods

Type III Effector Diversification via Both Pathoadaptation and Horizontal Transfer in Response to a Coevolutionary Arms Race

The concept of the coevolutionary arms race holds a central position in our understanding of pathogen–host interactions. Here we identify the molecular mechanisms and follow the stepwise progression of an arms race in a natural system. We show how the evolution and function of the HopZ family of type III secreted effector proteins carried by the plant pathogen Pseudomonas syringae are influenced by a coevolutionary arms race between pathogen and host. We surveyed 96 isolates of P. syringae and identified three homologs (HopZ1, HopZ2, and HopZ3) distributed among ∼45% of the strains. All alleles were sequenced and their expression was confirmed. Evolutionary analyses determined that the diverse HopZ1 homologs are ancestral to P. syringae, and have diverged via pathoadaptive mutational changes into three functional and two degenerate forms, while HopZ2 and HopZ3 have been brought into P. syringae via horizontal transfer from other ecologically similar bacteria. A PAML selection analysis revealed that the C terminus of HopZ1 is under strong positive selection. Despite the extensive genetic variation observed in this family, all three homologs have cysteine–protease activity, although their substrate specificity may vary. The introduction of the ancestral hopZ1 allele into strains harboring alternate alleles results in a resistance protein-mediated defense response in their respective hosts, which is not observed with the endogenous allele. These data indicate that the P. syringae HopZ family has undergone allelic diversification via both pathoadaptive mutational changes and horizontal transfer in response to selection imposed by the host defense system. This genetic diversity permits the pathogen to avoid host defenses while still maintaining a virulence-associated protease, thereby allowing it to thrive on its current host, while simultaneously impacting its host range

How Does Circadian Rhythm Impact Salt Sensitivity of Blood Pressure in Mice? A Study in Two Close C57Bl/6 Substrains

Background Mouse transgenesis has provided the unique opportunity to investigate mechanisms underlying sodium kidney reabsorption as well as end organ damage. However, understanding mouse background and the experimental conditions effects on phenotypic readouts of engineered mouse lines such as blood pressure presents a challenge. Despite the ability to generate high sodium and chloride plasma levels during high-salt diet, observed changes in blood pressure are not consistent between wild-type background strains and studies. Methods The present work was designed in an attempt to determine guidelines in the field of saltinduced hypertension by recording continuously blood pressure by telemetry in mice submitted to different sodium and potassium loaded diets and changing experimental conditions in both C57BL/6N and C57BL/6J mice strain (Normal salt vs. Low salt vs. High-salt/normal potassium vs. High salt/low potassium, standard vs. modified light cycle, Non-invasive tail cuff blood pressure vs. telemetry). Results In this study, we have shown that, despite a strong blood pressure (BP) basal difference between C57BL/6N and C57BL/6J mice, High salt/normal potassium diet increases BP and heart rate during the active phase only (dark period) in the same extent in both strains. On the other hand, while potassium level has no effect on salt-induced hypertension in C57BL/6N mice, high-salt/low potassium diet amplifies the effect of the high-salt challenge only in C57BL/6J mice. Indeed, in this condition, salt-induced hypertension can also be detected during light period even though this BP increase is lower compared to the one occurring during the dark period. Finally, from a methodological perspective, light cycle inversion has no effect on this circadian BP phenotype and tail-cuff method is less sensitive than telemetry to detect BP phenotypes due to salt challenges. Conclusions Therefore, to carry investigations on salt-induced hypertension in mice, chronic telemetry and studies in the active phase are essential prerequisites

Mixed Chamber Ensembles

Kennesaw State University School of Music presents Mixed Chamber Ensembles, 4:00 performance.https://digitalcommons.kennesaw.edu/musicprograms/1428/thumbnail.jp

Clinical and Serologic Manifestations of Autoimmune Disease in MRL-lpr/lpr Mice Lacking Nitric Oxide Synthase Type 2

Nitric oxide (NO) is an important mediator of the inflammatory response. MRL–lpr/lpr mice overexpress inducible nitric oxide synthase (NOS2) and overproduce NO in parallel with the development of an autoimmune syndrome with a variety of inflammatory manifestations. In previous studies, we showed that inhibiting NO production with the nonselective nitric oxide synthase (NOS) inhibitor NG-monomethyl–arginine reduced glomerulonephritis, arthritis, and vasculitis in MRL–lpr/lpr mice. To define further the role of NO and NOS2 in disease in MRL–lpr/lpr mice, mice with targeted disruption of NOS2 were produced by homologous recombination and bred to MRL–lpr/lpr mice to the N4 generation. MRL–lpr/lpr littermates homozygous for disrupted NOS2 (−/−), heterozygous for disrupted NOS2 (+/−), or wildtype (+/+) were derived for this study. Measures of NO production were markedly decreased in the MRL-lpr/lpr (−/−) mice compared with MRL-lpr/lpr (+/+) mice, with intermediate production by the MRL-lpr/lpr (+/−) mice. There was no detectable NOS2 protein by immunoblot analysis of the spleen, liver, kidney, and peritoneal macrophages of the (−/−) animals, whereas that of (+/+) was high and (+/−) intermediate. The (−/−) mice developed glomerular and synovial pathology similar to that of the (+/−) and (+/+) mice. However, (−/−) mice and (+/−) mice had significantly less vasculitis of medium-sized renal vessels than (+/+) mice. IgG rheumatoid factor levels were significantly lower in the (−/−) mice as compared with (+/+) mice, but levels of anti-DNA antibodies were comparable in all groups. Our findings show that NO derived from NOS2 has a variable impact on disease manifestations in MRL-lpr/lpr mice, suggesting heterogeneity in disease mechanisms