An Evaluation of Bridge Surveys for Monitoring River Otter Distribution in Ohio

River otters (Lontra canadensis) were once prevalent in the landscape of North America, but were trapped to low population numbers by the early 1900’s. Seventeen states and one Canadian province (Alberta) have successfully reintroduced river otters to their historical habitat. Biologists have carefully monitored the distribution and abundance of populations through the use of bridge surveys, public observation reports, snow-track surveys, and reports of road kill and incidentally trapped otters. Bridge surveys are the most common type of survey and are conducted at randomly generated sites once a year. This study looked at whether repeated visits would provide more data and therefore a better indicator of distribution and abundance of the river otter population in Ohio. Results showed an increase in sign presence detected on day 2 from day 1, but no increase in detection on day 3 from what was previously detected on days 1 and 2.In conjunction with the Ohio Department of Natural Resources, Division of Wildlif

Effect of monocytes/macrophages on the early osteogenic differentiation of hBMSCs

Heterotypic cell interactions are essential for the homeostasis of bone tissue, in particular the widely studied interaction between osteoblasts and osteoclasts. Closely related with osteoclasts are monocytes/macrophages. These have been shown to produce osteogenic factors, e.g. BMP-2, which plays a key role in bone metabolism. However, the mechanisms through which monocytes/macrophages interact with osteoblasts are still elusive. The aim of this work was to assess the influence of human peripheral blood monocytes/macrophages over the early osteogenic differentiation of human bone marrow stromal cells (hBMSCs) in the presence of dexamethasone-supplemented medium. The co-cultures were performed using porous transwells that allowed the interaction between both cell types through the production of paracrine factors. The potential effect of BMP-2 produced by monocytes/macrophages was addressed by adding an anti-BMP-2 antibody to the co-cultures. hBMSCs cultured in the presence of monocytes/macrophages had a higher proliferation rate than hBMSCs monocultures. The quantification of early osteogenic marker alkaline phosphatase (ALP) revealed higher activity of this enzyme in cells in the co-culture throughout the time of culture. Both of these effects were inhibited by adding an anti-BMP-2 antibody to the cultures. Moreover, qRTPCR for osteocalcin and osteopontin transcripts showed overexpression of both markers. Once again, the effect of monocytes/macrophages over hBMSC osteogenic differentiation was completely inhibited in the co-cultures by blocking BMP-2. The present report confirmed that monocytes/macrophages produce BMP-2, which promotes osteogenic differentiation and proliferation of hBMSCs cumulatively to dexamethasone-supplemented medium. This potentially implies that monocyte/macrophages play a stronger role in bone homeostasis than so far supposed

Signalling strategies for osteogenic differentiation of human umbilical cord mesenchymal stromal cells for 3D bone tissue engineering

Human umbilical cord mesenchymal stromal cells (hUCMSCs) have recently shown the capacity to differentiate into multiple cell lineages in all three embryonic germ layers. The osteogenic differentiation of hUCMSCs in monolayer culture has been reported, while the differentiation in three-dimensional biomaterials has not yet been reported for tissue-engineering applications. Thus, the aim of this study was to evaluate the feasibility of using hUCMSCs for bone tissue engineering. hUCMSCs were cultured in poly( L -lactic acid) (PLLA) scaffolds in osteogenic medium (OM) for 3 weeks, after which the scaffolds were exposed to several different media, including the OM, a mineralization medium (MM) and the MM with either 10 or 100 ng/ml insulin-like growth factor (IGF)-1. The osteogenic differentiation was confirmed by the up-regulation of Runx2 and OCN , calcium quantification and bone histology. Switching from the OM to the MM promoted collagen synthesis and calcium content per cell, while continuing in the OM retained more cells in the constructs and promoted higher osteogenic gene expression. The addition of IGF-1 into the MM had no effect on cell proliferation, differentiation and matrix synthesis. In conclusion, hUCMSCs show significant potential for bone tissue engineering and culturing in the OM throughout the entire period is beneficial for osteogenic differentiation of these cells. Copyright © 2009 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63045/1/176_ftp.pd

Proteoglycan 4: A dynamic regulator of skeletogenesis and parathyroid hormone skeletal anabolism

Proteoglycan 4 ( Prg4 ), known for its lubricating and protective actions in joints, is a strong candidate regulator of skeletal homeostasis and parathyroid hormone (PTH) anabolism. Prg4 is a PTH‐responsive gene in bone and liver. Prg4 null mutant mice were used to investigate the impact of proteoglycan 4 on skeletal development, remodeling, and PTH anabolic actions. Young Prg4 mutant and wild‐type mice were administered intermittent PTH(1–34) or vehicle daily from 4 to 21 days. Young Prg4 mutant mice had decreased growth plate hypertrophic zones, trabecular bone, and serum bone formation markers versus wild‐type mice, but responded with a similar anabolic response to PTH. Adult Prg4 mutant and wild‐type mice were administered intermittent PTH(1–34) or vehicle daily from 16 to 22 weeks. Adult Prg4 mutant mice had decreased trabecular and cortical bone, and blunted PTH‐mediated increases in bone mass. Joint range of motion and animal mobility were lower in adult Prg4 mutant versus wild‐type mice. Adult Prg4 mutant mice had decreased marrow and liver fibroblast growth factor 2 (FGF‐2) mRNA and reduced serum FGF‐2, which were normalized by PTH. A single dose of PTH decreased the PTH/PTHrP receptor (PPR), and increased Prg4 and FGF‐2 to a similar extent in liver and bone. Proteoglycan 4 supports endochondral bone formation and the attainment of peak trabecular bone mass, and appears to support skeletal homeostasis indirectly by protecting joint function. Bone‐ and liver‐derived FGF‐2 likely regulate proteoglycan 4 actions supporting trabeculae formation. Blunted PTH anabolic responses in adult Prg4 mutant mice are associated with altered biomechanical impact secondary to joint failure. © 2012 American Society for Bone and Mineral ResearchPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/89450/1/508_ftp.pd

3D Timelapse Analysis of Muscle Satellite Cell Motility

Skeletal muscle repair and regeneration requires the activity of satellite cells, a population of myogenic stem cells scattered throughout the tissue and activated to proliferate and differentiate in response to myotrauma or disease. While it seems likely that satellite cells would need to navigate local muscle tissue to reach damaged areas, relatively little data on such motility exist, and most studies have been with immortalized cell lines. We find that primary satellite cells are significantly more motile than myoblast cell lines, and that adhesion to laminin promotes primary cell motility more than fourfold over other substrates. Using timelapse videomicroscopy to assess satellite cell motility on single living myofibers, we have identified a requirement for the laminin-binding integrin α7β1 in satellite cell motility, as well as a role for hepatocyte growth factor in promoting directional persistence. The extensive migratory behavior of satellite cells resident on muscle fibers suggests caution when determining, based on fixed specimens, whether adjacent cells are daughters from the same mother cell. We also observed more persistent long-term contact between individual satellite cells than has been previously supposed, potential cell-cell attractive and repulsive interactions, and migration between host myofibers. Based on such activity, we assayed for expression of “pathfinding” cues, and found that satellite cells express multiple guidance ligands and receptors. Together, these data suggest that satellite cell migration in vivo may be more extensive than currently thought, and could be regulated by combinations of signals, including adhesive haptotaxis, soluble factors, and guidance cues. Stem Cells 2009;27:2527–253

Characterization of age-related gene expression profiling in bone marrow and epididymal adipocytes

<p>Abstract</p> <p>Background</p> <p>While an increase in bone marrow adiposity is associated with age-related bone disease, the function of bone marrow adipocytes has not been studied. The aim of this study was to characterize and compare the age-related gene expression profiles in bone marrow adipocytes and epididymal adipocytes.</p> <p>Results</p> <p>A total of 3918 (13.7%) genes were differentially expressed in bone marrow adipocytes compared to epididymal adipocytes. Bone marrow adipocytes revealed a distinct gene profile with low expression of adipocyte-specific genes peroxisome proliferator-activated receptor gamma (PPARγ), fatty acid binding protein 4 (FABP4), perilipin (Plin1), adipsin (CFD) and high expression of genes associated with early adipocyte differentiation (CCAAT/enhancer binding protein beta (C/EBPβ), regulator of G-protein signaling 2 (RGS2). In addition, a number of genes including secreted frizzled related protein 4 (SFRP4), tumor necrosis factor α (TNFα), transforming growth factor beta 1(TGFβ1), G-protein coupled receptor 109A (GPR109A) and interleukin 6 (IL-6), that could affect adipose-derived signaling to bone are markedly increased in bone marrow adipocytes. Age had a substantial effect on genes associated with mitochondria function and inflammation in bone marrow adipocytes. Twenty seven genes were significantly changed with age in both adipocyte depots. Among these genes, IL6 and GPR109A were significantly reduced with age in both adipocyte depots.</p> <p>Conclusions</p> <p>Overall, gene profiling reveals a unique phenotype for primary bone marrow adipocytes characterized by low adipose-specific gene expression and high expression of inflammatory response genes. Bone marrow and epididymal adipocytes share a common pathway in response to aging in mice, but age has a greater impact on global gene expression in epididymal than in bone marrow adipocytes. Genes that are differentially expressed at greater levels in the bone marrow are highly regulated with age.</p

Bioinspired materials and tissue engineering approaches applied to the regeneration of musculoskeletal tissues

The musculoskeletal tissues have a prime role in the biomechanical support and metabolic activities of the human body. As musculoskeletal tissues are highly prone to injuries, conditions afflicting these tissues have a great impact on the quality of life of patients worldwide. Tissue engineering approaches hold the promise to develop bioengineered substitutes aiming at the regeneration of failing and injured tissue and organs. To effectively address the tissue-specific structural and biochemical features of musculoskeletal tissues, different biomaterials and techniques have been employed envisioning biomimetic solutions. Herein, the unique composition, structure, and function of the musculoskeletal tissues, namely bone, cartilage, and tendon, as well as state-of-the-art technologies to develop bioinspired strategies for tissue regeneration will be overviewed. Finally, this chapter will also discuss the unmet challenges and future perspectives in the field.FCT Project MagTT PTDC/CTM-CTM/29930/2017 (POCI-01- 0145-FEDER-29930) for A.I.G postdoc grant, the FCT Project PTDC/NAN-MAT/30595/2017 (POCI-01-0145-FEDER-30595) for P.S.B. postdoc grant, and for the assistant researcher contract (RL1) of M.T.R from the project “Accelerating tissue engineering and personalized medicine discoveries by the integration of key enabling nanotechnologies, marine-derived biomaterials and stem cells” supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Authors acknowledge the financial support from the European Union Framework Programme for Research and Innovation HORIZON 2020, under the TEAMING Grant agreement No. 739572—The Discoveries CTR and the European Research Council 2017-CoG MagTendon (No. 772817