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Progeria Syndrome (progeria + syndrome)
Kinds of Progeria Syndrome Selected AbstractsMicrocephalia with mandibular and dental dysplasia in adult Zmpste24-deficient miceJOURNAL OF ANATOMY, Issue 5 2008F. De Carlos Abstract ZMPSTE24 (also called FACE-1) is a zinc-metalloprotease involved in the post-translational processing of prelamin A to mature lamin A, a major component of the nuclear envelope. Mutations in the ZMPSTE24 gene or in that encoding its substrate prelamin A (LMNA) result in a series of human inherited diseases known collectively as laminopathies and showing regional or systemic manifestations (i.e. the Hutchinson,Gilford progeria syndrome). Typically, patients suffering some laminopathies show craniofacial or mandible anomalies, aberrant dentition or facial features characteristic of aged persons. To analyse whether Zmpste24,/, mice reproduce the cranial phenotype observed in humans due to mutations in ZMPSTE24 or LMNA, we conducted a craniometric study based on micro-computer tomography (µCT) images. Furthermore, using simple radiology, µCT, µCT-densitometry and scanning electron microscopy, we analysed the mandible and the teeth from Zmpste24,/, mice. Finally, the structure of the lower incisor was investigated using an H&E technique. The results demonstrate that Zmpste24,/, mice are microcephalic and show mandibular and dental dysplasia affecting only the mandible teeth. In all cases, the lower incisor of mice lacking Zmpste24 was smaller than in control animals, showed cylindrical morphology and a transverse fissure at the incisal edge, and the pulpal cavity was severely reduced. Structurally, the dental layers were normally arranged but cellular layers were disorganized. The inferior molars showed a reduced cusp size. Taken together, these data strongly suggest that Zmpste24,/, mice represent a good model to analyse the craniofacial and teeth malformations characteristic of lamin-related pathologies, and might contribute to a better understanding of the molecular events underlying these diseases. [source] Inhibition of Lamin A/C Attenuates Osteoblast Differentiation and Enhances RANKL-Dependent Osteoclastogenesis,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2009Martina Rauner Abstract Age-related osteoporosis is characterized by low bone mass, poor bone quality, and impaired osteoblastogenesis. Recently, the Hutchinson-Gilford progeria syndrome (HGPS), a disease of accelerated aging and premature osteoporosis, has been linked to mutations in the gene encoding for the nuclear lamina protein lamin A/C. Here, we tested the hypothesis that inhibition of lamin A/C in osteoblastic lineage cells impairs osteoblastogenesis and accelerates osteoclastogenesis. Lamin A/C was knocked-down with small interfering (si)RNA molecules in human bone marrow stromal cells (BMSCs) differentiating toward osteoblasts. Lamin A/C knockdown led to an inhibition of osteoblast proliferation by 26% and impaired osteoblast differentiation by 48% based on the formation of mineralized matrix. In mature osteoblasts, expression levels of runx2 and osteocalcin mRNA were decreased by lamin A/C knockdown by 44% and 78%, respectively. Furthermore, protein analysis showed that osteoblasts with diminished levels of lamin A/C also secreted less osteocalcin and expressed a lower alkaline phosphatase activity (,50%). Lamin A/C inhibition increased RANKL mRNA and protein levels, whereas osteoprotegerin (OPG) expression was decreased, resulting in an increased RANKL/OPG ratio and an enhanced ability to support osteoclastogenesis, as reflected by a 34% increase of TRACP+ multinucleated cells. Our data indicate that lamin A/C is essential for proper osteoblastogenesis. Moreover, lack of lamin A/C favors an osteoclastogenic milieu and contributes to enhanced osteoclastogenesis. [source] Mechanobiology and the Microcirculation: Cellular, Nuclear and Fluid MechanicsMICROCIRCULATION, Issue 3 2010KRIS NOEL DAHL Microcirculation (2010) 17, 179,191. doi: 10.1111/j.1549-8719.2009.00016.x Abstract Endothelial cells are stimulated by shear stress throughout the vasculature and respond with changes in gene expression and by morphological reorganization. Mechanical sensors of the cell are varied and include cell surface sensors that activate intracellular chemical signaling pathways. Here, possible mechanical sensors of the cell including reorganization of the cytoskeleton and the nucleus are discussed in relation to shear flow. A mutation in the nuclear structural protein lamin A, related to Hutchinson-Gilford progeria syndrome, is reviewed specifically as the mutation results in altered nuclear structure and stiffer nuclei; animal models also suggest significantly altered vascular structure. Nuclear and cellular deformation of endothelial cells in response to shear stress provides partial understanding of possible mechanical regulation in the microcirculation. Increasing sophistication of fluid flow simulations inside the vessel is also an emerging area relevant to the microcirculation as visualization in situ is difficult. This integrated approach to study,including medicine, molecular and cell biology, biophysics and engineering,provides a unique understanding of multi-scale interactions in the microcirculation. [source] Hutchinson-Gilford progeria syndrome: oral and craniofacial phenotypesORAL DISEASES, Issue 3 2009DL Domingo Objective:, Hutchinson-Gilford progeria syndrome (HGPS) is a rare early-onset accelerated senescence syndrome. In HGPS, a recently identified de novo dominant mutation of the lamin A gene (LMNA) produces abnormal lamin A, resulting in compromised nuclear membrane integrity. Clinical features include sclerotic skin, cardiovascular and bone abnormalities, and marked growth retardation. Craniofacial features include ,bird-like' facies, alopecia, craniofacial disproportion, and dental crowding. Our prospective study describes dental, oral soft tissue, and craniofacial bone features in HGPS. Methods:, Fifteen patients with confirmed p.G608G LMNA mutation (1,17 years, seven males, eight females) received comprehensive oral evaluations. Anomalies of oral soft tissue, gnathic bones, and dentition were identified. Results:, Radiographic findings included hypodontia (n = 7), dysmorphic teeth (n = 5), steep mandibular angles (n = 11), and thin basal bone (n = 11). Soft tissue findings included ogival palatal arch (n = 8), median sagittal palatal fissure (n = 7), and ankyloglossia (n = 7). Calculated dental ages (9 months to 11 years 2 months) were significantly lower than chronological ages (1 year 6 months to 17 years 8 months) (P = 0.002). Eleven children manifested a shorter mandibular body, anterior/posterior cranial base and ramus, but a larger gonial angle, compared to age/gender/race norms. Conclusion:, Novel oral-craniofacial phenotypes and quantification of previously reported features are presented. Our findings expand the HGPS phenotype and provide additional insight into the complex pathogenesis of HGPS. [source] Caged Protein Prenyltransferase Substrates: Tools for Understanding Protein PrenylationCHEMICAL BIOLOGY & DRUG DESIGN, Issue 3 2008Amanda J. DeGraw Originally designed to block the prenylation of oncogenic Ras, inhibitors of protein farnesyltransferase currently in preclinical and clinical trials are showing efficacy in cancers with normal Ras. Blocking protein prenylation has also shown promise in the treatment of malaria, Chagas disease and progeria syndrome. A better understanding of the mechanism, targets and in vivo consequences of protein prenylation are needed to elucidate the mode of action of current PFTase (Protein Farnesyltransferase) inhibitors and to create more potent and selective compounds. Caged enzyme substrates are useful tools for understanding enzyme mechanism and biological function. Reported here is the synthesis and characterization of caged substrates of PFTase. The caged isoprenoid diphosphates are poor substrates prior to photolysis. The caged CAAX peptide is a true catalytically caged substrate of PFTase in that it is to not a substrate, yet is able to bind to the enzyme as established by inhibition studies and X-ray crystallography. Irradiation of the caged molecules with 350 nm light readily releases their cognate substrate and their photolysis products are benign. These properties highlight the utility of those analogs towards a variety of in vitro and in vivo applications. [source] Homozygous LMNA mutation R527C in atypical Hutchinson,Gilford progeria syndrome: evidence for autosomal recessive inheritanceACTA PAEDIATRICA, Issue 8 2009Lili Liang Abstract Aim:, To describe two Chinese siblings of atypical Hutchinson,Gilford progeria syndrome (HGPS), with genetic diagnosis and special clinical manifestation. Methods:, We screened the LMNA gene in four members of a consanguineous family, in which two children were suffering from atypical HGPS. Besides general HGPS features, such as growth retardation and characteristic appearance, special clinical phenotypes including disorders of digestive system and severe skeletal damages were observed. Results:, Homozygous mutation 1579C>T, which predicts R527C, was identified in the exon 9 of LMNA among the affected siblings. Heterozygous carrier status 1579C>T was detected in both of the asymptomatic parents. Conclusion:, Homozygous mutation R527C in LMNA yields atypical HGPS, and it suggests an autosomal recessive inheritance in this family. [source] Hutchinson,Gilford progeria syndrome with severe skin calcinosisCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 5 2007S. Nakamura Summary We describe a case of Hutchinson,Gilford progeria syndrome (HGPS) with long-term follow-up. A 1-month-old girl with marked sclerodermatous skin changes developed various symptoms of HGPS during follow-up. These included sclerotic skin, pigmentation, skin atrophy with translucent veins, wispy hair and alopecia, nail dystrophy and decreased sweating. Marked skin calcinosis was observed over almost the entire body, a symptom that has apparently been ignored in the literature. At 16 years old, the girl underwent surgery for a skull fracture and subdural haematoma, which was followed by chronic ulceration. Wet dressing with insulin-like growth factor was used with considerable effect. Mutation of the lamin A/C (LMNA) gene mutation, which encodes nuclear lamin A and C, has been reported to be the cause of HGPS. Our case showed the mutation G608G (GGC,GGT), which resulted in a cryptic splice site and consequently in a truncated lamin A/C protein. [source] | |||||||||||||