Saint Francis University

About: Saint Francis University is a education organization based out in Loretto, Pennsylvania, United States. It is known for research contribution in the topics: Population & Osteoblast. The organization has 1694 authors who have published 2038 publications receiving 87149 citations.

Ganglioglioma: a correlative clinicopathological and radiological study of ten surgically treated cases with follow-up.

Abstract: Gangliogliomas are rare benign tumors of the central nervous system containing neoplastic ganglion and low grade glial cells. In studying 10 surgically treated cases, we evaluated the clinical, pathological, radiological, and immunocytochemical features, with follow-up. Ranging from 18 to 58 years i

Skeletal Overexpression of Noggin Results in Osteopenia and Reduced Bone Formation

Abstract: Skeletal cells synthesize bone morphogenetic proteins (BMPs) and BMP antagonists. Noggin is a glycoprotein that binds BMPs selectively and antagonizes BMP actions. Noggin expression in osteoblasts is induced by BMPs and noggin opposes the effects of BMPs on osteoblastic differentiation and function in vitro. However, its effects in vivo are not known. We investigated the direct in vivo effects of noggin on bone remodeling in transgenic mice overexpressing noggin under the control of the osteocalcin promoter. Noggin transgenics suffered long bone fractures in the first month of life. Total, vertebral, and femoral bone mineral densities were reduced by 23-29%. Static and dynamic histomorphometry of the femur revealed that noggin transgenic mice had decreased trabecular bone volume, number of trabeculae, and bone formation rate. Osteoblast surface and number of osteoblasts/trabecular area were not significantly decreased, indicating impaired osteoblastic function. Osteoclast surface and number were normal/decreased, there was no increase in bone resorption, and the tissue had the appearance of woven bone. Vertebral microcomputed tomography scanning confirmed decreased trabecular bone volume and trabecular number. In conclusion, transgenic mice overexpressing noggin in the bone microenvironment have decreased trabecular bone volume and impaired osteoblastic function, leading to osteopenia and fractures.

Notch Inhibits Osteoblast Differentiation And Causes Osteopenia

Abstract: Notch receptors are determinants of cell fate decisions. To define the role of Notch in the adult skeleton, we created transgenic mice overexpressing the Notch intracellular domain(NICD)underthecontrolofthetypeIcollagenpromoter. First-generationtransgenicsweresmallandosteopenic.Bone histomorphometry revealed that NICD caused a decrease in bone volume, secondary to a reduction in trabecular number; osteoblast and osteoclast number were decreased. Low fertility of founder mice and lethality of young pups did not allow the complete establishment of transgenic lines. To characterize the effect of Notch overexpression in vitro, NICD was induced in osteoblasts and stromal cells from Rosa notch mice, in which a STOP cassette flanked by lox P sites is upstream of NICD, by transduction with an adenoviral vector expressing Cre recombinase (Cre) under the control of the cytomegalovirus (CMV) promoter (Ad-CMV-Cre). NICD impaired osteoblastogenesis and inhibited Wnt/-catenin signaling. To determine the effects of notch1 deletion in vivo, mice in which notch1 was flanked bylox P sequences (notch1 loxP/loxP ) were mated with mice expressing Cre recombinase under the control of the osteocalcin promoter. Conditional null notch1 mice had no obvious skeletal phenotype, possibly because of rescue by notch2; however, 1-month-old females exhibited a modest increase in osteoclast surface and eroded surface. Osteoblasts from notch1 loxP/loxP mice, transduced with Ad-CMV-Cre and transfected with Notch2 small interfering RNA, displayed increased alkaline phosphatase activity. In conclusion, Notch signaling in osteoblasts causes osteopenia and impairs osteoblastogenesis by inhibiting the Wnt/-catenin pathway. (Endocrinology 149: 3890–3899, 2008)