Rad GTPase is essential for the regulation of bone density and bone marrow adipose tissue in mice

The small GTP-binding protein Rad (RRAD, Ras associated with diabetes) is the founding member of the RGK (Rad, Rem, Rem2, and Gem/Kir) family that regulates cardiac voltage-gated Ca2 + channel function. However, its cellular and physiological functions outside of the heart remain to be elucidated. Here we report that Rad GTPase function is required for normal bone homeostasis in mice, as Rad deletion results in significantly lower bone mass and higher bone marrow adipose tissue (BMAT) levels. Dynamic histomorphometry in vivo and primary calvarial osteoblast assays in vitro demonstrate that bone formation and osteoblast mineralization rates are depressed, while in vitro osteoclast differentiation is increased, in the absence of Rad. Microarray analysis revealed that canonical osteogenic gene expression (Runx2, osterix, etc.) is not altered in Rad−/− calvarial osteoblasts; instead robust up-regulation of matrix Gla protein (MGP, + 11-fold), an inhibitor of extracellular matrix mineralization and a protein secreted during adipocyte differentiation, was observed. Strikingly, Rad deficiency also resulted in significantly higher marrow adipose tissue levels in vivo and promoted spontaneous in vitro adipogenesis of primary calvarial osteoblasts. Adipogenic differentiation of wildtype calvarial osteoblasts resulted in the loss of endogenous Rad protein, further supporting a role for Rad in the control of BMAT levels. These findings reveal a novel in vivo function for Rad and establish a role for Rad signaling in the complex physiological control of skeletal homeostasis and bone marrow adiposity

Reversal of loss of bone mass in old mice treated with mefloquine

Aging is accompanied by imbalanced bone remodeling, elevated osteocyte apoptosis, and decreased bone mass and mechanical properties; and improved pharmacologic approaches to counteract bone deterioration with aging are needed. We examined herein the effect of mefloquine, a drug used to treat malaria and systemic lupus erythematosus and shown to ameliorate bone loss in glucocorticoid-treated patients, on bone mass and mechanical properties in young and old mice. Young 3.5-month-old and old 21-month-old female C57BL/6 mice received daily injections of 5 mg/kg/day mefloquine for 14 days. Aging resulted in the expected changes in bone volume and mechanical properties. In old mice mefloquine administration reversed the lower vertebral cancellous bone volume and bone formation; and had modest effects on cortical bone volume, thickness, and moment of inertia. Mefloquine administration did not change the levels of the circulating bone formation markers P1NP or alkaline phosphatase, whereas levels of the resorption marker CTX showed trends towards increase with mefloquine treatment. In addition, and as expected, aging bones exhibited an accumulation of active caspase3-expressing osteocytes and higher expression of apoptosis-related genes compared to young mice, which were not altered by mefloquine administration at either age. In young animals, mefloquine induced higher periosteal bone formation, but lower endocortical bone formation. Further, osteoclast numbers were higher on the endocortical bone surface and circulating CTX levels were increased, in mefloquine- compared to vehicle-treated young mice. Consistent with this, addition of mefloquine to bone marrow cells isolated from young mice led to increased osteoclastic gene expression and a tendency towards increased osteoclast numbers in vitro. Taken together our findings identify the age and bone-site specific skeletal effects of mefloquine. Further, our results highlight a beneficial effect of mefloquine administration on vertebral cancellous bone mass in old animals, raising the possibility of using this pharmacologic inhibitor to preserve skeletal health with aging

Molecular, Environmental DNA and Phylogenetic Analysis of the Endangered Species of Nebraska (Salt Creek Tiger Beetle) Ellipsoptera Nevadica Lincolniana

Salt Creek tiger beetle (SCTB) is an ecologically important tiger beetle species. It is found in the Ellipsoptera genus. There are 13 species in the genus Ellipsoptera genus and 9 subspecies. Ellipsoptera nevadica lincolniana (Salt Creek tiger beetle) is a subspecies in the nevadica species. Other Ellipsoptera nevadica subspecies are knausii nevadica, olmosa, and citata. SCTB was listed as a federally endangered subspecies on November 7, 2005. It is an extremely niche-specific, spends most of its life as a larva, most often observed as an adult. The most common habitats for SCTB are barren salt flats and saline stream edges of the saline wetlands. It has one of the most restricted ranges of any insect in the United States. Known metapopulations include Little Salt Creek Arbor Lake, Little Salt Creek Roper, Upper Little Salt Creek-north, Upper Little Salt Creek-south, Jack Sinn WMA, and Oak Creek. Only three metapopulations still exist. On May 6, 2014, a final rule designated 449 hectares for SCTB recovery was published. The purpose of this study is to use DNA to infer, the evolutionary relationship between Ellipsoptera nevadica lincolniana with other species and subspecies in the genus Ellipsoptera. a second objective is to evaluate the genetics of wild SCTB and those maintained in culture. Originally, the Ellipsoptera nevadica lincolniana was described as a separate species. But more recently, based on geographical and morphological evidence, it was reclassified as a subspecies in the Ellipsoptera nevadica species. It is believed that E. nevadica lincolniana has been geographically isolated from other populations since either the Kansan glaciation or pre-Illinoian glacial stage. Further studies proved that the E. nevadica lincolniana is a Highly niche-specific species compared to the other subspecies in the nevadica species. Even though it is geographically and morphologically closely related to the E. nevadica knausii, the two subspecies have significant ecological and behavioral differences. This study provides additional comparative DNA sequence information of Ellipsoptera species that may aid in their monitoring and identification. The study also examines the possibility of environmental DNA environmental DNA approach for the monitoring of the salt creek tiger beetles. The study results demonstrate the potential of the use of eDNA in Salt Creek tiger beetles\u27 identification. It is believed that if the eDNA is embraced will improve the conservation strategies. eDNA is a nondestructive way to study beetle. If embraced it would reduce the need of tissue or larvae in studies and monitoring of tiger beetle species