Prevention of glucocorticoid induced-apoptosis of osteoblasts and osteocytes by protecting against endoplasmic reticulum (ER) stress in vitro and in vivo in female mice

Endoplasmic reticulum (ER) stress is associated with increased reactive oxygen species (ROS), results from accumulation of misfolded/unfolded proteins, and can trigger apoptosis. ER stress is alleviated by phosphorylation of eukaryotic translation initiation factor 2α (eIF2α), which inhibits protein translation allowing the ER to recover, thus promoting cell viability. We investigated whether osteoblastic cell apoptosis induced by glucocorticoids (GCs) is due to induction of ROS/ER stress and whether inhibition of eIF2α dephosphorylation promotes survival opposing the deleterious effects of GC in vitro and in vivo. Apoptosis of osteocytic MLO-Y4 and osteoblastic OB-6 cells induced by dexamethasone was abolished by ROS inhibitors. Like GC, the ER stress inducing agents brefeldin A and tunicamycin induced osteoblastic cell apoptosis. Salubrinal or guanabenz, specific inhibitors of eIF2α dephosphorylation, blocked apoptosis induced by either GC or ER stress inducers. Moreover, GC markedly decreased mineralization in OB-6 cells or primary osteoblasts; and salubrinal or guanabenz increased mineralization and prevented the inhibitory effect of GC. Furthermore, salubrinal (1 mg/kg/day) abolished osteoblast and osteocyte apoptosis in cancellous and cortical bone and partially prevented the loss of BMD at all sites and the decreased vertebral cancellous bone formation induced by treatment with prednisolone for 28 days (1.4 mg/kg/day). We conclude that part of the pro-apoptotic actions of GC on osteoblastic cells is mediated through ER stress, and that inhibition of eIF2α dephosphorylation protects from GC-induced apoptosis of osteoblasts and osteocytes in vitro and in vivo and from the deleterious effects of GC on the skeleton

Seed Quality Assurance in Maize Breeding Programs: Tests to Explain Variations in Maize Inbreds and Populations

Maize (Zea mays L.) breeders are interested in evaluating the seed quality of their inbred lines, as seed quality has a strong relationship to field emergence. There is little information, however, on the influence of the seed quality of the inbred on field emergence of the hybrid. The objectives of this research were to (i) determine whether seed quality tests and a seed quality index of the inbred parents and F2 seed are correlated with field emergence of F1hybrids, and (ii) determine how many tests are necessary to calculate this index. Standard germination (SG), saturated cold (SC), and soak (Soak) tests, and the inbred quality index (IQI) were calculated on inbred parents and their corresponding F2 progeny, and field emergence was measured on associated F1 hybrids produced in Clinton, IL in 2002 and 2003. The tests and index of the parental inbreds and F2 progeny correlated poorly with early field emergence of the F1 hybrids. All tests were required to calculate the seed quality index. By averaging several seed quality tests into a single index, the poor seed quality performance of inbreds and F2 populations in some tests can be masked by other tests. The seed quality index might be useful when ranking inbreds based on seed quality but not as a selection tool

PTHrP-Derived Peptides Restore Bone Mass and Strength in Diabetic Mice: Additive Effect of Mechanical Loading

There is an unmet need to understand the mechanisms underlying skeletal deterioration in diabetes mellitus (DM) and to develop therapeutic approaches to treat bone fragility in diabetic patients. We demonstrate herein that mice with type 1 DM induced by streptozotocin exhibited low bone mass, inferior mechanical and material properties, increased bone resorption, decreased bone formation, increased apoptosis of osteocytes, and increased expression of the osteocyte-derived bone formation inhibitor Sost/sclerostin. Further, short treatment of diabetic mice with parathyroid hormone related protein (PTHrP)-derived peptides corrected these changes to levels undistinguishable from non-diabetic mice. In addition, diabetic mice exhibited reduced bone formation in response to mechanical stimulation, which was corrected by treatment with the PTHrP peptides, and higher prevalence of apoptotic osteocytes, which was reduced by loading or by the PTHrP peptides alone and reversed by a combination of loading and PTHrP peptide treatment. In vitro experiments demonstrated that the PTHrP peptides or mechanical stimulation by fluid flow activated the survival kinases ERKs and induced nuclear translocation of the canonical Wnt signaling mediator β-catenin, and prevented the increase in osteocytic cell apoptosis induced by high glucose. Thus, PTHrP-derived peptides cross-talk with mechanical signaling pathways to reverse skeletal deterioration induced by DM in mice. These findings suggest a crucial role of osteocytes in the harmful effects of diabetes on bone and raise the possibility of targeting these cells as a novel approach to treat skeletal deterioration in diabetes. Moreover, our study suggests the potential therapeutic efficacy of combined pharmacological and mechanical stimuli to promote bone accrual and maintenance in diabetic subjects

Seed Quality Assurance in Maize Breeding Programs: Tests to Explain Variations in Maize Inbreds and Populations

Maize (Zea mays L.) breeders are interested in evaluating the seed quality of their inbred lines, as seed quality has a strong relationship to field emergence. There is little information, however, on the influence of the seed quality of the inbred on field emergence of the hybrid. The objectives of this research were to (i) determine whether seed quality tests and a seed quality index of the inbred parents and F2 seed are correlated with field emergence of F1hybrids, and (ii) determine how many tests are necessary to calculate this index. Standard germination (SG), saturated cold (SC), and soak (Soak) tests, and the inbred quality index (IQI) were calculated on inbred parents and their corresponding F2 progeny, and field emergence was measured on associated F1 hybrids produced in Clinton, IL in 2002 and 2003. The tests and index of the parental inbreds and F2 progeny correlated poorly with early field emergence of the F1 hybrids. All tests were required to calculate the seed quality index. By averaging several seed quality tests into a single index, the poor seed quality performance of inbreds and F2 populations in some tests can be masked by other tests. The seed quality index might be useful when ranking inbreds based on seed quality but not as a selection tool.This article is published as Goggi, A. Susana, Petrutza Caragea, Linda Pollak, Gina McAndrews, Mindy DeVries, and Kevin Montgomery. "Seed quality assurance in maize breeding programs: Tests to explain variations in maize inbreds and populations." Agronomy journal 100, no. 2 (2008): 337-343. doi: 10.2134/agronj2007.0151.</p

MMP14 is a novel target of PTH signaling in osteocytes that controls resorption by regulating soluble RANKL production

Parathyroid hormone (PTH) affects the skeleton by acting on osteocytes (Ots) in bone through yet unclear mechanisms. We report that matrix metalloproteinase 14 (MMP14) expression/activity are increased in bones from mice with genetic constitutive activation (ca) of the PTH receptor 1 (PTH1R) in Ots (caPTH1ROt) and in bones from mice exposed to elevated PTH levels but not in mice lacking [conditional knockout (cKO)] the PTH1R in Ots (cKOPTH1ROt). Furthermore, PTH upregulates MMP14 in human bone cultures and in Ot-enriched bones from floxed control mice but not from cKOPTH1ROt mice. MMP14 activity increases soluble receptor activator of NF-κΒ ligand production, which in turn, stimulates osteoclast differentiation and resorption. Pharmacologic inhibition of MMP14 activity reduced the high bone remodeling exhibited by caPTH1ROt mice or induced by chronic PTH elevation and decreased bone resorption but allowed full stimulation of bone formation induced by PTH injections, thereby potentiating bone gain. Thus, MMP14 is a new member of the intricate gene network activated in Ots by PTH1R signaling that can be targeted to adjust the skeletal responses to PTH in favor of bone preservation.-Delgado-Calle, J., Hancock, B., Likine, E. F., Sato, A. Y., McAndrews, K., Sanudo, C., Bruzzaniti, A., Riancho, J. A., Tonra, J. R., Bellido, T. MMP14 is a novel target of PTH signaling in osteocytes that controls resorption by regulating soluble RANKL production

Facilitating a more efficient commercial review process for pediatric drugs and biologics

Over the past two decades, the biopharmaceutical industry has seen unprecedented expansion and innovation in concert with significant technological advancements. While the industry has experienced marked growth, the regulatory system in the United States still operates at a capacity much lower than the influx of new drug and biologic candidates. As a result, it has become standard for months or even years of waiting for commercial approval by the U.S. Food and Drug Administration. These regulatory delays have generated a system that stifles growth and innovation due to the exorbitant costs associated with awaiting approval from the nation’s sole regulatory agency. The recent re-emergence of diseases that impact pediatric demographics represents one particularly acute reason for developing a regulatory system that facilitates a more efficient commercial review process. Herein, we present a range of initiatives that could represent early steps toward alleviating the delays in approving life-saving therapeutics