We have previously mapped autosomal dominant spinocerebellar ataxia (SCA) 16 to 3p26, overlapping with the locus of SCA15. Recently, partial deletions of ITPR1 and the neighbouring SUMF1 in the SCA15 and two additional families were reported. In the present study we determined the copy number of these genes by real time quantitative polymerase chain reaction (PCR) and found a heterozygous deletion of exons 1-48 of ITPR1, but not SUMF1 in SCA16. Breakpoint analysis revealed that the size of the deletion is 313,318 bp and the telomeric breakpoint is located in the middle of their intergenic region. Our data provide evidence that haploinsufficiency of ITPR1 alone causes SCA16 and SCA15.

Bilateral femurs of 12-week-old female Sprague-Dawley rats were fractured, and the fractured femurs were harvested 36 h, 3, 7, 10, and 14 days after the fracture. Localization of cell proliferation in the fracture calluses was investigated using immunohistochemistry with antiproliferating cell nuclear antigen (PCNA) monoclonal antibodies. Thirty-six hours after the fracture, many PCNA-positive cells were observed in the whole callus. The change was not limited to mesenchymal cells at the fracture site where the inflammatory reaction had occurred, but extended in the periosteum along almost the entire femoral diaphysis where intramembranous ossification was initiated. On day 3, periosteal cells or premature osteoblasts in the newly formed trabecular bone during intramembranous ossification still displayed intense staining. On day 7, many premature chondrocytes and proliferating chondrocytes were PCNA positive. Endochondral ossification appeared on days 10 and 14, and the premature osteoblasts and endothelial cells in the endochondral ossification front were stained with anti-PCNA antibodies. Quantification of PCNA-positive cells was carried out using an image analysis computer system, obtaining a PCNA score for each cellular event. The highest score was observed in the periosteum early after the fracture near the fracture site. Immunohistochemistry using anti-PCNA antibodies showed that the distribution of proliferating cells and the degree of cell proliferation varied according to the time lag after the fracture, suggesting the existence of local regulatory factors such as growth factors, and that significant cell proliferation was observed at the beginning of each cellular event. (J Bone Miner Res 1997;12:96-102)

Mutations in the fused in sarcoma gene (FUS) were recently found in patients with familial amyotrophic lateral sclerosis (ALS). The present study aimed to clarify unique features of familial ALS caused by FUS mutation in the Japanese population. We carried out clinical, neuropathological, and genetic studies on a large Japanese pedigree with familial ALS. In six successive generations of this family, 16 individuals of both sexes were affected by progressive muscle atrophy and weakness, indicating an autosomal dominant trait. Neurological examination of six patients revealed an age at onset of 48.2+/-8.1 years in fourth generation patients, while it was 31 and 20 years in fifth and sixth generation patients, respectively. Motor paralysis progressed rapidly in these patients, culminating in respiratory failure within 1 year. The missense mutation c.1561 C>T (p.R521C) was found in exon 15 of FUS in the four patients examined. Neuropathological study of one autopsied case with the FUS mutation revealed multiple system degeneration in addition to upper and lower motor neuron involvement: the globus pallidus, thalamus, substantia nigra, cerebellum, inferior olivary nucleus, solitary nucleus, intermediolateral horn, Clarke's column, Onuf's nucleus, central tegmental tract, medial lemniscus, medial longitudinal fasciculus, superior cerebellar peduncle, posterior column, and spinocerebellar tract were all degenerated. Argyrophilic and basophilic neuronal or glial cytoplasmic inclusions immunoreactive for FUS, GRP78/BiP, p62, and ubiquitin were detected in affected lesions. The FUS R521C mutation in this Japanese family caused familial ALS with pathological features of multiple system degeneration and neuronal basophilic inclusions.

No abstract

Abstract. The phenotypic effects of selectively altering the levels of otB-crystallin in cultured glial cells were analyzed using sense and antisense approaches. Rat C6 glioma cells and human U-373MG glioma cells were transfected with a rat t~B-crystaUin sense eDNA or an antisense eDNA regulated by a Rous sarcoma virus promoter to alter cellular levels of uBcrystallin. The antisense strategy resulted in decreased otB-crystallin levels, as revealed by Western blot and immunocytochemical analyses. The reduced o~B-crystallin expression was accompanied by alterations in cellular phenotype: (a) a reduction of cell size and/or a slender cell morphology; (b) a disorganized microfilarnent network; and (c) a reduction of cell adhesiveness. Like HSP27, the presence of additional otB-crystallin protein confers a thermoresistant phenotype to stable transfectants. Thus, otB-crystallin in glioma cells plays a role in their thermal resistance and may contribute to the stability of cytoskeletal organization.o[-CRYSTALLIN is a major component of the vertebrate eye lens and consists of two genes, c~A and o~B. It has become clear in recent years that both subunits of ot-crystallin are present in nonlenticular tissues, aB-crystallin is found in such extraocular tissues as heart, skeletal muscle, skin, brain and kidney, and in cultured rat astrocytes and neoplastic astrocytes (6,15,25,27,28,34). c~A-crystallin is also present in nonlens tissues, especially in spleen and thymus (33). Although c~-crystallin under physiologic conditions is always isolated from lens as heterogeneous high molecular weight aggregates of o~A-crystallin and otB-crystallin, the distribution of these two proteins in nonlenticular tissue is different.Not only do the ot-crystallins structurally resemble a class of small MW heat shock proteins (42, 50, 51) and o~B-crystallin forms a complex with HSP27, one of the small heat shock proteins, in adenovirus-transformed rat kidney cells (52) and in human skeletal muscle (32), but also recent evidence indicates that t~B-crystailin is itself a heat shock, or "stress" protein. Thus, otB-crystallin rnRNA is increased in NIH 3T3 mouse fibroblasts (35), in cultured glioma cells (26), in normal cultured astrocytes (20), and in lens, kidney, and retinal epithelial cells (13, 39) in response to such diverse stimuli as heat shock, heavy metal exposure, hypoxia, hypertonicity, and hypoglycemia, otB-crystaUin accumulates in reactive and neoplastic glial cells and in some neurons in a variety of pathologic situations (25,29,30) presumably Address all correspondence to Dr. Toru Iwaki, Department of Neuropathology, Neurological Institute, Faculty of Medicine, Kyushu University 60, Maidashi 3-1-1, Higashi-ku, Fukuoka 812, Japan. reflecting some as yet unidentified stresses. In a remarkable example of stress protein expression, both otB-crystailin and hsp27 accumulate in massive amounts in the brains of patients with Alexander disease and is a major component of Rosenthal fibers, intracytoplasmic inclusions of reactive astrocytes (28...