Characteristics of Pulmonary Arterial Hypertension in Patients with Systemic Sclerosis and Anticentriole Autoantibodies.

Anticentriole autoantibodies-positive systemic sclerosis (SSc) has been reported to develop pulmonary arterial hypertension (PAH) at a high rate. In this report, we describe two patients with anticentriole antibodies-positive SSc-PAH who were treated with pulmonary vasodilators. Both cases were elderly women with poor physical conditions and clinical findings of SSc. Case 1 was resistant to combination therapy with pulmonary vasodilators; in Case 2, hemodynamic improvement was obtained by upfront combination therapy at an early stage. Because anticentriole antibodies-positive SSc-PAH rapidly deteriorates, careful hemodynamic observation and timely aggressive use of pulmonary vasodilators should be considered.

NANOG/NANOGP8 Localizes at the Centrosome and is Spatiotemporally Associated with Centriole Maturation.

NANOG is a transcription factor involved in the regulation of pluripotency and stemness. The functional paralog of NANOG, NANOGP8, differs from NANOG in only three amino acids and exhibits similar reprogramming activity. Given the transcriptional regulatory role played by NANOG, the nuclear localization of NANOG/NANOGP8 has primarily been considered to date. In this study, we investigated the intriguing extranuclear localization of NANOG and demonstrated that a substantial pool of NANOG/NANOGP8 is localized at the centrosome. Using double immunofluorescence, the colocalization of NANOG protein with pericentrin was identified by two independent anti-NANOG antibodies among 11 tumor and non-tumor cell lines. The validity of these observations was confirmed by transient expression of GFP-tagged NANOG, which also colocalized with pericentrin. Mass spectrometry of the anti-NANOG immunoprecipitated samples verified the antibody specificity and revealed the expression of both NANOG and NANOGP8, which was further confirmed by real-time PCR. Using cell fractionation, we show that a considerable amount of NANOG protein is present in the cytoplasm of RD and NTERA-2 cells. Importantly, cytoplasmic NANOG was unevenly distributed at the centrosome pair during the cell cycle and colocalized with the distal region of the mother centriole, and its presence was markedly associated with centriole maturation. Along with the finding that the centrosomal localization of NANOG/NANOGP8 was detected in various tumor and non-tumor cell types, these results provide the first evidence suggesting a common centrosome-specific role of NANOG.

Centrioles control the capacity, but not the specificity, of cytotoxic T cell killing.

Immunological synapse formation between cytotoxic T lymphocytes (CTLs) and the target cells they aim to destroy is accompanied by reorientation of the CTL centrosome to a position beneath the synaptic membrane. Centrosome polarization is thought to enhance the potency and specificity of killing by driving lytic granule fusion at the synapse and thereby the release of perforin and granzymes toward the target cell. To test this model, we employed a genetic strategy to delete centrioles, the core structural components of the centrosome. Centriole deletion altered microtubule architecture as expected but surprisingly had no effect on lytic granule polarization and directional secretion. Nevertheless, CTLs lacking centrioles did display substantially reduced killing potential, which was associated with defects in both lytic granule biogenesis and synaptic actin remodeling. These results reveal an unexpected role for the intact centrosome in controlling the capacity but not the specificity of cytotoxic killing.

The centriolar satellite protein CCDC66 interacts with CEP290 and functions in cilium formation and trafficking.

Centriolar satellites are membrane-less structures that localize and move around the centrosome and cilium complex in a microtubule-dependent manner. They play important roles in centrosome- and cilium-related processes, including protein trafficking to the centrosome and cilium complex, and ciliogenesis, and they are implicated in ciliopathies. Despite the important regulatory roles of centriolar satellites in the assembly and function of the centrosome and cilium complex, the molecular mechanisms of their functions remain poorly understood. To dissect the mechanism for their regulatory roles during ciliogenesis, we performed an analysis to determine the proteins that localize in close proximity to the satellite protein CEP72, among which was the retinal degeneration gene product CCDC66. We identified CCDC66 as a microtubule-associated protein that dynamically localizes to the centrosome, centriolar satellites and the primary cilium throughout the cell cycle. Like the BBSome component BBS4, CCDC66 distributes between satellites and the primary cilium during ciliogenesis. CCDC66 has extensive proximity interactions with centrosome and centriolar satellite proteins, and co-immunoprecipitation experiments revealed interactions between CCDC66, CEP290 and PCM1. Ciliogenesis, ciliary recruitment of BBS4 and centriolar satellite organization are impaired in cells depleted for CCDC66. Taken together, our findings identify CCDC66 as a targeting factor for centrosome and cilium proteins.

Linear scleroderma with prominent multiple lymphadenopathy followed by the development of polymyositis: A case report and review of published work.

Localized scleroderma is an inflammatory disorder affecting the skin and underlying tissues, a certain subset of which develops other autoimmune diseases on the basis of a prominent autoimmune background. We here report a unique case of linear scleroderma presenting with a sclerotic plaque on the left thigh, multiple lymphadenopathy in bilateral inguinal and para-aortic lymph nodes, and hepatosplenomegaly, who later developed polymyositis. We describe the detailed disease course of our case and discuss the clinical significance of multiple lymphadenopathy in localized scleroderma based on a review of published work.

High incidence of pulmonary arterial hypertension in systemic sclerosis patients with anti-centriole autoantibodies.

Systemic sclerosis (SSc)-related autoantibodies are useful tools in identifying clinically homogenous subsets of patients and predicting their prognosis. In this report, we described five SSc patients with anti-centriole antibodies. All five patients were females and had digital ulcers/gangrene. Four of five (80%) patients had pulmonary arterial hypertension (PAH). None of the five patients had active pulmonary fibrosis or developed renal crisis. Anti-centriole antibodies may be a marker for PAH and digital ulcers/gangrene.

Cell cycle regulation of the murine 8-oxoguanine DNA glycosylase (mOGG1): mOGG1 associates with microtubules during interphase and mitosis.

8-Oxoguanine DNA glycosylase (OGG1) is a major DNA repair enzyme in mammalian cells. OGG1 participates in the repair of 8-oxoG, the most abundant known DNA lesion induced by endogenous reactive oxygen species in aerobic organisms. In this study, antibodies directed against purified recombinant human OGG1 (hOGG1) or murine (mOGG1) protein were chemically conjugated to either the photosensitizer Rose Bengal or the fluorescent dye Texas red. These dye-protein conjugates, in combination with binding assays, were used to identify associations between mOGG1 and the cytoskeleton of NIH3T3 fibroblasts. Results from these binding studies showed that mOGG1 associates with the cytoskeleton by specifically binding to the centriole and microtubules radiating from the centrosome at interphase and the spindle assembly at mitosis. Similar results were obtained with hOGG1. Together results reported in this study suggest that OGG1 is a microtubule-associated protein itself or that OGG1 utilizes yet to be identified motor proteins to ride on microtubules as tracks facilitating the movement and redistribution of cytoplasmic OGG1 pools during interphase and mitosis and in response to oxidative DNA damage.

A case of scleroderma spectrum disorder with anticentriole antibody and pulmonary hypertension.

We describe the case of a patient with anticentriole antibody-positive scleroderma spectrum disorder (SSD) who developed pulmonary hypertension. A 54-year-old woman had noticed Raynaud's phenomenon and digital ulcers during the winter for the past 10 years. Although sclerodactyly was not present, digital ulcers, swelling of her hands, and phalangeal contracture were observed. An indirect immunofluorescence test revealed anticentriole antibody. Other SSc-specific antoantibodies were negative. An echocardiogram demonstrated that the estimated right ventricular systolic pressure was increased to 51 mmHg. She was diagnosed as SSD with pulmonary hypertension. This is the first case of SSD with anticentriole antibody to develop pulmonary hypertension.

[Centrosome morphogenesis in the early development of mice: an immunofluorescence study using antibodies to the centriole antigen]. / Morfogenez tsentrosomy v rannem razvitii myshei: immunofluorestsentnoe issledovanie s pomoshch'iu antitel k antigenu tsentriolei.

The distribution of a centrosomal antigen, recognized by RN-C6 monoclonal antibody (monAB. RN-C6), was studied. The monAB. RN-C6 was directed against the common phosphoepitope in several high molecular cell proteins. In the mouse embryonal fibroblasts the monAB. RN-C6 stained discrete spots in the interphase nuclei, centrioles throughout the cell cycle and the midbody in mitosis. In the oocytes and the early mouse embryos, the monAB. RN-C6 stained only the nuclei, the staining of pronuclei in zygote being absent. In the mouse spermatozoon, the monAB. RN-C6 recognized the centriole and axoneme. Nevertheless, the stained sperm axoneme was revealed in the cytoplasm of early embryos up to the morula stage. No staining was observed in the mitotic spindle or in the midbody, or in any dots in the cytoplasm of oocytes/early embryos. On the blastocyst stage, the monAB. RN-C6 stained first the cytoplasmic dots in some cells, in the spindle poles and midbody. The appearance of stained dots and mitotic figures coincides with that of centrioles revealed at the ultrastructural level in some cells. Thus, during centrosome formation a given centriolar antigen is found only in the centriole, never being accumulated previously in the cytoplasm or in cell organelles.

A molecular marker for centriole maturation in the mammalian cell cycle.

The centriole pair in animals shows duplication and structural maturation at specific cell cycle points. In G1, a cell has two centrioles. One of the centrioles is mature and was generated at least two cell cycles ago. The other centriole was produced in the previous cell cycle and is immature. Both centrioles then nucleate one procentriole each which subsequently elongate to full-length centrioles, usually in S or G2 phase. However, the point in the cell cycle at which maturation of the immature centriole occurs is open to question. Furthermore, the molecular events underlying this process are entirely unknown. Here, using monoclonal and polyclonal antibody approaches, we describe for the first time a molecular marker which localizes exclusively to one centriole of the centriolar pair and provides biochemical evidence that the two centrioles are different. Moreover, this 96-kD protein, which we name Cenexin (derived from the Latin, senex for "old man," and Cenexin for centriole) defines very precisely the mature centriole of a pair and is acquired by the immature centriole at the G2/M transition in prophase. Thus the acquisition of Cenexin marks the functional maturation of the centriole and may indicate a change in centriolar potential such as its ability to act as a basal body for axoneme development or as a congregating site for microtubule-organizing material.

A tightly bound chromosome antigen is detected by monoclonal antibodies in a ring-like structure on human centromeres.

Monoclonal antibodies (Mabs) were raised against isolated Chinese hamster protein-depleted chromosomes Chromosome scaffolds) in order to probe for components involved in the higher-order structure of mammalian chromosomes. One of the Mabs detected a ring-like structure in metaphase at the centromere, which is conserved between Chinese hamster and human cells. Additionally, the Mab stained the centrioles in interphase cells in these two species. The antigen was enriched in chromosomal protein preparations by comparison with nuclear protein samples, and has an apparent Mr = 170,000. The centromere antigen remained present in chromosome scaffold preparations, indicating that it was tightly associated with DNA. The antigen was distinct in its centromeric localisation from any of the centromere antigens reported to date. A possible role of the antigen in stabilising the centromere, by holding the sister chromatids together until their separation at the metaphase-anaphase transition is presented.

Anticentriolar autoantibodies in children with central nervous system manifestations of Mycoplasma pneumoniae infection.

Serum samples from 49 children with acute Mycoplasma pneumoniae infection were screened for the presence of antibodies to mitotic spindle apparatus. None of these serum samples showed such antibodies at a screening dilution of 1:40, though anticentriolar antibodies at titres of 1:320 were observed in two children with acute cerebellar dysfunction. Anticentriolar antibodies may play a part in the pathogenesis of CNS disease associated with M pneumoniae infection.

Antibodies to centromere and centriole in scleroderma spectrum disorders.

The importance of early detection of scleroderma spectrum disorders (SSD) has been emphasized. We determined the clinical distribution of anticentromere antibody (ACA) and anticentriole antibody in the following four groups: (1) 264 patients with SSD, including 193 with systemic sclerosis, 29 with mixed connective tissue disease and 42 with suspected secondary Raynaud's phenomenon (RP); (2) 26 patients with primary RP; (3) 248 patients with other connective tissue diseases, and (4) 139 patients with other skin diseases. The frequency of ACA was significantly higher in SSD (78/264, 30%) than in the other groups. In patients with SSD, the incidence of ACA in suspected secondary RP (28/42, 67%) was similar to that in type I systemic sclerosis (24/36, 67%). Anticentriole antibody was detected in only 1 patient with suspected secondary RP (0.4%) out of the 264 SSD patients. These data indicate that anticentriole antibody is very rare and that the antibodies against mitosis-related antigens such as centromere and centriole are associated with early SSD.

[Anti-centriole antibodies and high neuron-specific enolase activity in a patient with Raynaud phenomenon, cerebrovascular lesions, and ischemic finger necrosis--a functional relationship?]. / Anti-Zentriolen-Antikörper und hohe neuronenspezifische Enolase-Aktivität bei einer Patientin mit Raynaud-Phänomen, zerebrovaskulären Läsionen und ischämischen Fingernekrosen--ein assoziierter Befund?

In a 49-year-old patient with acute thrombangitis obliterans, several vascular risk factors and associated features of collagen vascular disease, we observed anti-centriole autoantibodies and a strongly elevated neuron-specific enolase (NSE). The latter could not be attributed to an underlying malignant or neuroendocrine disease. The recent identification of NSE as a centrosomal protein suggests a causal relationship between anti-centriole autoantibodies and elevated serum NSE levels.

Geographical clustering of scleroderma in a rural area in the province of Rome.

A geographical cluster of scleroderma and scleroderma-related features was identified in a rural area in the province of Rome. Two patients with scleroderma, three with CREST syndrome and one with eosinophilic fasciitis were living in a village where the total population included 572 persons of voting age. No kindred relationships were demonstrable among these patients. Clinical features of scleroderma such as Raynaud's phenomenon, bilateral hand edema, and digital scars were detected in an additional 10 cases. A group of apparently healthy subjects with scleroderma-related serological abnormalities (circulating antinuclear and anticentriole autoantibodies) was also identified in the village. No disease-associated HLA antigen in the patients nor genetic differences between patients and healthy subjects living in the same village were detected by HLA typing. Some still unidentified environmental factors acting on genetically predisposed subjects may be responsible for the clustering of the disease seen in this study.

Preferential dendritic localization of pericentriolar material in hippocampal pyramidal neurons in culture.

Centrosomes are unique cytoplasmic structures which serve as microtubule organizing centers (MTOC). In most animal cells centrosomes consist of one or more pair of centrioles surrounded by electron dense amorphous pericentriolar material (PCM) responsible for nucleation of microtubules. In the present study we analyzed the pattern of induction and localization of proteins of the PCM at different stages of neuronal development in cell cultures prepared from the embryonic hippocampus. For this purpose we used a human polyclonal antibody that recognizes two proteins of the PCM (100 kd and 60 kd, respectively). The results indicate that in mature neurons, pericentriolar immunoreactive material is preferentially localized in dendritic processes, and that throughout the course of neurite development and differentiation it is systematically excluded from the neuron's axon. Western blot analysis showed that during neuronal development in situ, there is an increase in the immunoreactivity for both proteins recognized by this antibody. In contrast, in hippocampal pyramidal neurons that develop in culture, there is an increase in the 60 kd polypeptide, while the 100 kd one is not detected after 7 days in vitro.

A monoclonal antibody, raised against mammalian centrosomes and screened by recognition of plant microtubule organizing centers, identifies a pericentriolar component in different cell types.

We have used monoclonal antibodies raised against isolated native calf thymus centrosomes to probe the structure and composition of the pericentriolar material. To distinguish prospective antibodies as specific to conserved elements of this material, we screened clones by their identification of microtubule organizing centers (MTOCs) in different animal and plant cells. Among the clonal antibodies that reacted with MTOCs in both plant and mammalian cells, we describe one (mAb 6C6) that was found to immunostain centrosomes in a variety of bovine and human cells. In cycling cells this signal persisted through the entire cell cycle. Microscopy showed that the mAb 6C6 antigen was a component of the pericentriolar material and this was confirmed by biochemical analysis of centrosomes. Using immunoblot analysis of protein fractions derived from purified components of centrosomes, we have characterized the mAb 6C6 antigen as a 180 kDa polypeptide. We conclude that we have identified a protein component permanently associated with the pericentriolar material. Surprisingly, monoclonal antibody 6C6 also stained other mitotic organelles in mammalian cells, in a cell-cycle-dependent manner. During prometaphase and metaphase the antibody stained both centrosomes and kinetochores. At the onset of anaphase the kinetochore-specific staining dissociated from chromosomes and was subsequently redistributed onto a newly characterized organelle, the telophase disc while the centrosomal stain remained intact. It is not known if the 180 kDa centrosomal protein itself redistributes during mitosis, or if the pattern observed represents other antigens with shared epitopes. The pericentriolar material is thought to be composed of conserved elements, which appeared very early during the evolution of eukaryotes. Our results strongly suggest that mAb 6C6 identifies one of these elements.

Human centrosomal epitope is shared specifically with human lactate dehydrogenase-B isozyme.

A rabbit serum (0013) used to identify pericentriolar proteins from isolated centrosomes (Gosti-Testu, F., Marty, M.C., Berges, J., Maunoury, R. and Bornens, M. (1986) EMBO J. 5, 2545-2550) was shown also to react through the same epitope with several non-centrosomal proteins including a major 36 kDa cytosolic antigen. This protein was identified to be human lactate dehydrogenase and the co-distribution of 0013 epitope on the centrosomal protein and on lactate dehydrogenase (LDH) was shown to be specific for human cells (Gosti, F., Marty, M.C., Courvalin, J.C., Maunoury, R. and Bornens, M. (1987) Proc. Natl. Acad. Sci. USA 84, 1000-1004). Human hepatic cells constitute, so far, the only exception to this co-distribution rule. By using this cell type which expresses only the LDH-A4 isozyme, we demonstrate that 0013 epitope is specific for the human LDH-B subunit, making serum 0013 the strongest anti-LDH-B available so far. The evolutionary and physiological significance of this situation is discussed.

Autoantibodies to the centrosome (centriole) react with determinants present in the glycolytic enzyme enolase.

Autoantibodies to cellular Ag are found in the sera of patients with systemic rheumatic diseases. Identification and characterization of the reactive autoantigens has helped clinicians to define subsets of rheumatic diseases and has assisted biologists in defining the function within the cell of these molecules. We have studied autoantibodies from patients that react with the centrosome (centriole) region of the cell. We found by immunoblotting techniques that these antibodies react with a 48-kDa protein. Additional immunoblotting and affinity purification studies indicate that the Ag may be the glycolytic enzyme enolase.