Application of Microfluidics for Bacterial Identification.

Bacterial infections continue to pose serious public health challenges. Though anti-bacterial therapeutics are effective remedies for treating these infections, the emergence of antibiotic resistance has imposed new challenges to treatment. Often, there is a delay in prescribing antibiotics at initial symptom presentation as it can be challenging to clinically differentiate bacterial infections from other organisms (e.

Influence of interface in electrical properties of 3D printed structures.

The aligned bond interfaces resulting from the layer-by-layer nature of material extrusion-based additive manufacturing (MEAM) leads to anisotropic properties in printed parts. This study examines the anisotropy in electrical impedance and its variation with print parameters. Samples consisting of a stack of filaments are used to study the interfaces, which are the fundamental building block of MEAM, in a controlled manner.

Senescent cells exacerbate chronic inflammation and contribute to periodontal disease progression in old mice.

Background: Coinciding with other chronic comorbidities, the prevalence of periodontal disease increases with aging. Mounting evidence has established that senescent cells accumulate at sites of age-related pathologies, where they promote "non-microbial" inflammation. We hypothesized that alveolar bone osteocytes develop senescence characteristics in old age.

Accelerated osteocyte senescence and skeletal fragility in mice with type 2 diabetes.

The worldwide prevalence of type 2 diabetes (T2D) is increasing. Despite normal to higher bone density, patients with T2D paradoxically have elevated fracture risk resulting, in part, from poor bone quality. Advanced glycation endproducts (AGEs) and inflammation as a consequence of enhanced receptor for AGE (RAGE) signaling are hypothesized culprits, although the exact mechanisms underlying skeletal dysfunction in T2D are unclear.

LPS-induced premature osteocyte senescence: Implications in inflammatory alveolar bone loss and periodontal disease pathogenesis.

Cellular senescence is associated with inflammation and extracellular matrix tissue remodeling through the secretion of proteins termed the senescence-associated secretory phenotype (SASP). Although osteocyte senescence in older individuals in the skeleton is well recognized, whether young alveolar osteocytes can also become senescent is unknown. This is potentially important in the context of periodontal disease, which is an inflammatory condition caused by a gradual change from symbiotic to pathogenic oral microflora that can lead to tooth loss.

Independent Roles of Estrogen Deficiency and Cellular Senescence in the Pathogenesis of Osteoporosis: Evidence in Young Adult Mice and Older Humans.

Estrogen deficiency is a seminal mechanism in the pathogenesis of osteoporosis. Mounting evidence, however, establishes that cellular senescence, a fundamental mechanism that drives multiple age-related diseases, also causes osteoporosis. Recently, we systematically identified an accumulation of senescent cells, characterized by increased p16 and p21 levels and development of a senescence-associated secretory phenotype (SASP), in mouse bone/marrow and human bone with aging.

miR-219a-5p Regulates Rorβ During Osteoblast Differentiation and in Age-related Bone Loss.

Developing novel approaches to treat skeletal disorders requires an understanding of how critical molecular factors regulate osteoblast differentiation and bone remodeling. We have reported that (1) retinoic acid receptor-related orphan receptor beta (Rorβ) is upregulated in bone samples isolated from aged mice and humans in vivo; (2) Rorβ expression is inhibited during osteoblastic differentiation in vitro; and (3) genetic deletion of Rorβ in mice results in preservation of bone mass during aging. These data establish that Rorβ inhibits osteogenesis and that strict control of Rorβ expression is essential for bone homeostasis.

Senolytics improve physical function and increase lifespan in old age.

Physical function declines in old age, portending disability, increased health expenditures, and mortality. Cellular senescence, leading to tissue dysfunction, may contribute to these consequences of aging, but whether senescence can directly drive age-related pathology and be therapeutically targeted is still unclear. Here we demonstrate that transplanting relatively small numbers of senescent cells into young mice is sufficient to cause persistent physical dysfunction, as well as to spread cellular senescence to host tissues.

Osteoprotection Through the Deletion of the Transcription Factor Rorβ in Mice.

There is a clinical need to identify new molecular targets for the treatment of osteoporosis, particularly those that simultaneously inhibit bone resorption while stimulating bone formation. We have previously shown in overexpression studies that retinoic acid receptor-related orphan receptor β (Rorβ) suppresses in vitro osteoblast differentiation. In addition, the expression of Rorβ is markedly increased in bone marrow-derived mesenchymal stromal cells with aging in both mice and humans.

Corrigendum: Targeting cellular senescence prevents age-related bone loss in mice.

This corrects the article DOI: 10.1038/nm.4385.

Targeting cellular senescence prevents age-related bone loss in mice.

Aging is associated with increased cellular senescence, which is hypothesized to drive the eventual development of multiple comorbidities. Here we investigate a role for senescent cells in age-related bone loss through multiple approaches. In particular, we used either genetic (i.

Identification of Senescent Cells in the Bone Microenvironment.

Cellular senescence is a fundamental mechanism by which cells remain metabolically active yet cease dividing and undergo distinct phenotypic alterations, including upregulation of p16 , profound secretome changes, telomere shortening, and decondensation of pericentromeric satellite DNA. Because senescent cells accumulate in multiple tissues with aging, these cells and the dysfunctional factors they secrete, termed the senescence-associated secretory phenotype (SASP), are increasingly recognized as promising therapeutic targets to prevent age-related degenerative pathologies, including osteoporosis. However, the cell type(s) within the bone microenvironment that undergoes senescence with aging in vivo has remained poorly understood, largely because previous studies have focused on senescence in cultured cells.

Deletion of Estrogen Receptor Beta in Osteoprogenitor Cells Increases Trabecular but Not Cortical Bone Mass in Female Mice.

Although the role of ERα in regulating bone metabolism has been extensively studied, ERβ has been largely dismissed as a relevant modulator of bone mass. Previous studies examining ERβ utilized a germline knockout mouse expressing transcript variants of ERβ and displaying systemic hormonal changes that confounded interpretation of the skeletal phenotype. Thus, we used a conditional ERβ mouse model to achieve deletion of ERβ specifically in early osteoprogenitor cells using the Prx1-Cre driver.

Ability of circulating human hematopoietic lineage negative cells to support hematopoiesis.

Hematopoietic stem cell (HSC) self-renewal is regulated by osteoblast and/or endothelial cells within the hematopoietic niche. However, the true identity of the supporting cells and the nature of the secreted factors remain uncertain. We developed a novel mouse model and analyzed whether circulating human peripheral hematopoietic lineage negative/AP+ (lin-/AP+) cells support hematopoiesis in vivo.

Characterization of blood in an encrustation on an African mask: spectroscopic and direct analysis in real time mass spectrometric identification of haem.

Prior to exhibiting an African Komo mask from the collections of the Detroit Institute of Arts, a multianalytical approach was undertaken to characterize the flaking encrusted coating on the surface of the mask. Preliminary XRF and FTIR examination of the coating on the Komo mask revealed the presence of significant quantities of iron and protein, possibly indicating the presence of blood. Raman spectroscopy showed evidence for the porphyrin structure of haem as well.

Examination of ERα signaling pathways in bone of mutant mouse models reveals the importance of ERE-dependent signaling.

The mechanisms of estrogen receptor (ER)-α activity can be categorized into those involving direct (classical) or indirect (nonclassical) DNA binding. Although various mouse models have demonstrated the importance of ERα in bone, the specific gene expression patterns affected by these modes of ERα action are unknown. In this report, the gene expression patterns of ERα-deficient (ERKO) mice and nonclassical ER knock-in (NERKI) mice, which can function only by nonclassical means, were analyzed.

Induction of fracture repair by mesenchymal cells derived from human embryonic stem cells or bone marrow.

Development of novel therapeutic approaches to repair fracture non-unions remains a critical clinical necessity. We evaluated the capacity of human embryonic stem cell (hESC)-derived mesenchymal stem/stromal cells (MSCs) to induce healing in a fracture non-union model in rats. In addition, we placed these findings in the context of parallel studies using human bone marrow MSCs (hBM-MSCs) or a no cell control group (n = 10-12 per group).

Distinct effects of loss of classical estrogen receptor signaling versus complete deletion of estrogen receptor alpha on bone.

Estrogen receptor (ER) α is a major regulator of bone metabolism which can modulate gene expression via a "classical" pathway involving direct DNA binding to estrogen-response elements (EREs) or via "non-classical" pathways involving protein-protein interactions. While the skeletal consequences of loss of ERE binding by ERα have been described, a significant unresolved question is how loss of ERE binding differs from complete loss of ERα. Thus, we compared the skeletal phenotype of wild-type (ERα(+/+)) and ERα knock out (ERα(-/-)) mice with that of mice in which the only ERα present had a knock-in mutation abolishing ERE binding (non-classical ERα knock-in [NERKI], ERα(-/NERKI)).

Effects of chronic estrogen treatment on modulating age-related bone loss in female mice.

While female mice do not have the equivalent of a menopause, they do undergo reproductive senescence. Thus, to dissociate the effects of aging versus estrogen deficiency on age-related bone loss, we sham-operated, ovariectomized, or ovariectomized and estrogen-replaced female C57/BL6 mice at 6 months of age and followed them to age 18 to 22 months. Lumbar spines and femurs were excised for analysis, and bone marrow hematopoietic lineage negative (lin-) cells (enriched for osteoprogenitor cells) were isolated for gene expression studies.

Skeletal consequences of deletion of steroid receptor coactivator-2/transcription intermediary factor-2.

Both estrogen receptor (ER) and peroxisome proliferator-activated receptor gamma (PPARgamma) regulate bone metabolism, and because steroid receptor coactivator (SRC)-2 (TIF-2) enhances ER and PPARgamma activity, we examined the consequences of deletion of SRC-2 on bone using SRC-2 knock out (KO) mice. Loss of SRC-2 resulted in increased bone mass, with SRC-2 KO mice having 80% higher trabecular bone volume as compared with wild type mice. SRC-2 KO mice also had a marked decrease (by 50%) in bone marrow adipocytes.

Effects of loss of classical estrogen response element signaling on bone in male mice.

The role of estrogen signaling in the male skeleton via estrogen receptor (ER)-alpha is now well established. ERalpha can elicit responses through either classical estrogen response elements (ERE) pathways or nonclassical, non-ERE pathways. In the present study, we examined the effects of either the attenuation or loss of classical ERalpha signaling on the murine male skeleton.

TGFbeta inducible early gene-1 knockout mice display defects in bone strength and microarchitecture.

TGFbeta inducible early gene-1 (TIEG) is a member of the Sp/Krüppel-like transcription factor family originally cloned from human osteoblasts. We have previously demonstrated that TIEG plays a role in the expression of important osteoblast marker genes and in the maturation/differentiation of osteoblasts. To elucidate the function of TIEG in skeletal development and maintenance, we have generated a TIEG knockout (KO) mouse.

Skeletal effects of estrogen are mediated by opposing actions of classical and nonclassical estrogen receptor pathways.

Unlabelled: ER alpha acts either through classical (ERE-mediated) or nonclassical (non-ERE) pathways. The generation of mice carrying a mutation that eliminates classical ER alpha signaling presents a unique opportunity to study the relative roles of these pathways in bone. This study defines the skeletal phenotype and responses to ovariectomy and estrogen replacement in these mice.

Arginase activity differs with allergen in the effector phase of ovalbumin- versus trimellitic anhydride-induced asthma.

Both trimellitic anhydride (TMA), a small molecular weight chemical, and ovalbumin (OVA), a reference protein allergen, cause asthma with eosinophilia. To test the hypothesis that different allergens elicit symptoms of asthma via different effector pathways, gene expression was compared in lungs of Balb/c mice sensitized with either TMA or OVA, followed by intratracheal challenge with TMA conjugated to mouse serum albumin (TMA-MSA) or OVA, respectively. Sensitized animals challenged with mouse serum albumin (MSA) alone were controls.