Age-related differences in human skin proteoglycans

Previous work has shown that versican, decorin and a catabolic fragment of decorin, termed decorunt, are the most abundant proteoglycans in human skin. Further analysis of versican indicates that four major core protein species are present in human skin at all ages examined from fetal to adult. Two of these are identified as the V0 and V1 isoforms, with the latter predominating. The other two species are catabolic fragments of V0 and V1, which have the amino acid sequence DPEAAE as their carboxyl terminus. Although the core proteins of human skin versican show no major age-related differences, the glycosaminoglycans (GAGs) of adult skin versican are smaller in size and show differences in their sulfation pattern relative to those in fetal skin versican. In contrast to human skin versican, human skin decorin shows minimal age-related differences in its sulfation pattern, although, like versican, the GAGs of adult skin decorin are smaller than those of fetal skin decorin. Analysis of the catabolic fragments of decorin from adult skin reveals the presence of other fragments in addition to decorunt, although the core proteins of these additional decorin catabolic fragments have not been identified. Thus, versican and decorin of human skin show age-related differences, versican primarily in the size and the sulfation pattern of its GAGs and decorin in the size of its GAGs. The catabolic fragments of versican are detected at all ages examined, but appear to be in lower abundance in adult skin compared with fetal skin. In contrast, the catabolic fragments of decorin are present in adult skin, but are virtually absent from fetal skin. Taken together, these data suggest that there are age-related differences in the catabolism of proteoglycans in human skin. These age-related differences in proteoglycan patterns and catabolism may play a role in the age-related changes in the physical properties and injury response of human ski

1.5 T augmented reality navigated interventional MRI: paravertebral sympathetic plexus injections

PURPOSE:The high contrast resolution and absent ionizing radiation of interventional magnetic resonance imaging (MRI) can be advantageous for paravertebral sympathetic nerve plexus injections. We assessed the feasibility and technical performance of MRI-guided paravertebral sympathetic injections utilizing augmented reality navigation and 1.5 T MRI scanner.METHODS:A total of 23 bilateral injections of the thoracic (8/23, 35%), lumbar (8/23, 35%), and hypogastric (7/23, 30%) paravertebral sympathetic plexus were prospectively planned in twelve human cadavers using a 1.5 Tesla (T) MRI scanner and augmented reality navigation system. MRI-conditional needles were used. Gadolinium-DTPA-enhanced saline was injected. Outcome variables included the number of control magnetic resonance images, target error of the needle tip, punctures of critical nontarget structures, distribution of the injected fluid, and procedure length.RESULTS: Augmented-reality navigated MRI guidance at 1.5 T provided detailed anatomical visualization for successful targeting of the paravertebral space, needle placement, and perineural paravertebral injections in 46 of 46 targets (100%). A mean of 2 images (range, 1–5 images) were required to control needle placement. Changes of the needle trajectory occurred in 9 of 46 targets (20%) and changes of needle advancement occurred in 6 of 46 targets (13%), which were statistically not related to spinal regions (P = 0.728 and P = 0.86, respectively) and cadaver sizes (P = 0.893 and P = 0.859, respectively). The mean error of the needle tip was 3.9±1.7 mm. There were no punctures of critical nontarget structures. The mean procedure length was 33±12 min.CONCLUSION:1.5 T augmented reality-navigated interventional MRI can provide accurate imaging guidance for perineural injections of the thoracic, lumbar, and hypogastric sympathetic plexus

Granzyme B Cleaves Decorin, Biglycan and Soluble Betaglycan, Releasing Active Transforming Growth Factor-β1

Objective: Granzyme B (GrB) is a pro-apoptotic serine protease that contributes to immune-mediated target cell apoptosis. However, during inflammation, GrB accumulates in the extracellular space, retains its activity, and is capable of cleaving extracellular matrix (ECM) proteins. Recent studies have implicated a pathogenic extracellular role for GrB in cardiovascular disease, yet the pathophysiological consequences of extracellular GrB activity remain largely unknown. The objective of this study was to identify proteoglycan (PG) substrates of GrB and examine the ability of GrB to release PG-sequestered TGF-b1 into the extracellular milieu. Methods/Results: Three extracellular GrB PG substrates were identified; decorin, biglycan and betaglycan. As all of these PGs sequester active TGF-b1, cytokine release assays were conducted to establish if GrB-mediated PG cleavage induced TGF-b1 release. Our data confirmed that GrB liberated TGF-b1 from all three substrates as well as from endogenous ECM and this process was inhibited by the GrB inhibitor 3,4-dichloroisocoumarin. The released TGF-b1 retained its activity as indicated by the induction of SMAD-3 phosphorylation in human coronary artery smooth muscle cells. Conclusion: In addition to contributing to ECM degradation and the loss of tissue structural integrity in vivo, increase

Report of the NIH Task Force on Research Standards for Chronic Low Back Pain

Despite rapidly increasing intervention, functional disability due to chronic low back pain (cLBP) has increased in recent decades. We often cannot identify mechanisms to explain the major negative impact cLBP has on patients’ lives. Such cLBP is often termed non-specific, and may be due to multiple biologic and behavioral etiologies. Researchers use varied inclusion criteria, definitions, baseline assessments, and outcome measures, which impede comparisons and consensus. The NIH Pain Consortium therefore charged a Research Task Force (RTF) to draft standards for research on cLBP. The resulting multidisciplinary panel recommended using 2 questions to define cLBP; classifying cLBP by its impact (defined by pain intensity, pain interference, and physical function); use of a minimal data set to describe research participants (drawing heavily on the PROMIS methodology); reporting “responder analyses” in addition to mean outcome scores; and suggestions for future research and dissemination. The Pain Consortium has approved the recommendations, which investigators should incorporate into NIH grant proposals. The RTF believes these recommendations will advance the field, help to resolve controversies, and facilitate future research addressing the genomic, neurologic, and other mechanistic substrates of chronic low back pain. We expect the RTF recommendations will become a dynamic document, and undergo continual improvement.Perspective: A Task Force was convened by the NIH Pain Consortium, with the goal of developing research standards for chronic low back pain. The results included recommendations for definitions, a minimal dataset, reporting outcomes, and future research. Greater consistency in reporting should facilitate comparisons among studies and the development of phenotypes

Dermatan sulfate proteoglycans from the mineralized matrix of the avian eggshell

The eggshell of the chicken is a useful model to study matrix components which affect biomineralization. As an extension of our previous immunohistochemical work which suggested the presence of dermatan sulfate proteoglycans in the mineralized region of the eggshell, a study was undertaken to characterize these molecules biochemically. After demineralization with HCl and extraction with 4 M guanidinium chloride containing protease inhibitors, the extract was partitioned by anion exchange chromatography. Step elution with 0.25 M and 1.0 M sodium chloride resulted in the generation of two fractions, both of which contain chondroitinase-sensitive proteoglycans with molecular weights estimated at 200,000 by gel electrophoresis. The proteoglycans in each fraction have core proteins with molecular weights of approximately 120,000 and glycosaminoglycans with average molecular weights of 22,000. Based on differential sensitivity to chondroitinase ABC and AC II, these glycosaminoglycans contai

Fungal and Bacterial Communities Exhibit Consistent Responses to Reversal of Soil Acidification and Phosphorus Limitation over Time

Chronic acid deposition affects many temperate hardwood forests of the northeastern United States, reduces soil pH and phosphorus (P) availability, and can alter the structure and function of soil microbial communities. The strategies that microorganisms possess for survival in acidic, low P soil come at a carbon (C) cost. Thus, how microbial communities respond to soil acidification in forests may be influenced by plant phenological stage as C allocation belowground varies; however, this remains largely unexplored. In this study, we examined microbial communities in an ecosystem level manipulative experiment where pH and/or P availability were elevated in three separate forests in Northeastern Ohio. Tag-encoded pyrosequencing was used to examine bacterial and fungal community structure at five time points across one year corresponding to plant phenological stages. We found significant effects of pH treatment and time on fungal and bacterial communities in soil. However, we found no interaction between pH treatment and time of sampling for fungal communities and only a weak interaction between pH elevation and time for bacterial communities, suggesting that microbial community responses to soil pH are largely independent of plant phenological stage. In addition, fungal communities were structured largely by site, suggesting that fungi were responding to differences between the forests, such as plant community differences

Sulfated proteoglycans in astroglial barriers inhibit neurite outgrowth in vitro

In vivo studies of the roof plate of the spinal cord and midline optic tectum in rodent and the developing subplate in the telencephalon of the chick showed that two glycosaminoglycans, keratan sulfate and chondroitin sulfate, possibly in the proteoglycan form (KS-PG, CS-PG, or KS/CS-PG), were present at times when axons approach closely but do not invade these territories. To address the question of whether KS/CS-PG actively inhibits growth cone elongation and to determine which component(s) of the proteoglycan may be critical to this phenomenon, we used a technique employing nitrocellulose-coated petri dishes onto which stripes of various purified macromolecules were attached. Isolated E9 chick dorsal root ganglia were grown on lanes of KS/CS-PG in alternation with lanes of the growth-promoting molecule laminin (LN). Neurite outgrowth was abundant along stripes of LN. In contrast, upon encountering a stripe containing KS/CS-PG, neurites either stopped abruptly or turned and traveled along the KS/CS-PG stripe border. The effect was dependent upon the concentration of the proteoglycan with intermediate concentrations producing intermittent patterns of crossing. We mixed LN with the KS/CS-PG, where the LN was in concentrations which alone support outgrowth, and observed that the KS/CS-PG was still inhibitory when such a growth-promoting molecule was present. A 10-fold higher concentration of LN was able to overcome the inhibitory effect of the KS/CS-PG. These results suggest that the interaction of inhibitory and growth-promoting molecules can interact to produce a wide spectrum of neurite patterns ranging from complete inhibition to totally unimpeded outgrowth. Selective enzymatic removal of the KS or CS from the KS/CS-PG permitted various degrees of neurite outgrowth to occur across the previously inhibitory lanes, and digestion of both glycosaminoglycan moieties, leaving only the protein core of the molecule, resulted in a complete lack of inhibition. These assays demonstrated that KS/CS-PG is inhibitory to embryonic dorsal root ganglia neurites in vitro and that complete inhibition requires contributions from both KS and CS moieties

Impact of Deer and Soil Chemistry on Plant Mutualists in Forest Soil

In temperate forests, understory herbaceous plants are often affected by the abundance of white tailed deer, both directly through herbivory and indirectly through soil compaction. Soil chemistry, particularly soil pH, also has a large effect on the soil microbial communities that influence plant growth and survival. The objective of this study was to study the interactive effects of deer herbivory and soil chemistry on plant mutualists in forest soil using Jack-in-the-Pulpit plants. Jack-in-the-Pulpit are common understory herbs in temperate forests that deer will eat but are not preferred. In Bole Woods at the Holden Arboretum, 760 Jack-in-the-Pulpit plants were planted into 19 plots (both deer exclosures and un-fenced controls), each containing 4 subplots, 3 where soil chemistry had been altered and a control. Soil samples were collected from each subplot to be used for DNA analysis. Using PCR-terminal restriction fragment length polymorphism, we determined community structure of the fungal and bacterial communities. Our results showed that across communities of general fungal, AM fungi and bacteria, there were taxonomic differences present with soil chemistry alteration. Subplots that were amended with limestone and calcium had similar communities compared to subplots that were amended with triple superphosphate or the control. These differences reflected changes in soil pH that we had seen previously.</p