Globular Cytoplasmic Inclusions Research Articles

Age-dependent formation of TMEM106B amyloid filaments in human brains

Many age-dependent neurodegenerative diseases, such as Alzheimer’s and Parkinson’s, are characterized by abundant inclusions of amyloid filaments. Filamentous inclusions of the proteins tau, amyloid-β, α-synuclein and transactive response DNA-binding protein (TARDBP; also known as TDP-43) are the most common1,2. Here we used structure determination by cryogenic electron microscopy to show that residues 120–254 of the lysosomal type II transmembrane protein 106B (TMEM106B) also form amyloid filaments in human brains. We determined the structures of TMEM106B filaments from a number of brain regions of 22 individuals with abundant amyloid deposits, including those resulting from sporadic and inherited tauopathies, amyloid-β amyloidoses, synucleinopathies and TDP-43 proteinopathies, as well as from the frontal cortex of 3 individuals with normal neurology and no or only a few amyloid deposits. We observed three TMEM106B folds, with no clear relationships between folds and diseases. TMEM106B filaments correlated with the presence of a 29-kDa sarkosyl-insoluble fragment and globular cytoplasmic inclusions, as detected by an antibody specific to the carboxy-terminal region of TMEM106B. The identification of TMEM106B filaments in the brains of older, but not younger, individuals with normal neurology indicates that they form in an age-dependent manner.

Waldenstrom Macroglobulinaemia with Signet Ring Cells: A Case Report

Waldenstrom Macroglobulinemia (WM) is an indolent lymphoproliferative disorder characterised by Immunoglobulin M (IgM) production and neoplastic lymphoid infiltrate. The morphology of the neoplastic cells show spectrum of maturation characterised by small lymphocytes, lymphoplasmacytoid cells and plasma cells. The infiltrate is predominantly lymphoid with relatively small population of plasma cells. The plasma cell morphology is commonly of mature type with basophilic cytoplasm, eccentric nucleus with clumped chromatin and perinuclear halo (hof). But incidence of signet ring cells in WM is very rare and only one case has been reported till date. Here, authors report an interesting case of a 61-year-old man who presented with on and off chest pain and later diagnosed as WM with signet ring cells. On examination, the patient was found to have anaemia and lymphadenopathy. Bone marrow aspirate cytology showed hypercellular particles and scattered signet ring like plasma cells with large globular cytoplasmic inclusions. Flow Cytometry (FCM) established the diagnosis by demonstrating the clonal nature of plasma cells and B-lymphoid cells. Immunofixation confirmed the presence of monoclonal protein of IgM lambda type. The cytoplasmic content in these signet ring plasma cells is probably the accumulated IgM due to the defect in releasing. Clustering of these signet ring cells in marrow may raise a suspicion of metastatic adenocarcinoma and should not be misinterpreted.

Tau exhibits unique seeding properties in globular glial tauopathy

Tauopathies are neurodegenerative disorders characterized by aggregation of microtubule associated tau protein in neurons and glia. They are clinically and pathologically heterogeneous depending on the isoform of tau protein that accumulates (three or four 31-to-32-amino-acid repeats [3R or 4R] in the microtubule binding domain), as well as the cellular and neuroanatomical distribution of tau pathology. Growing evidence suggests that distinct tau conformers may contribute to the characteristic features of various tauopathies. Globular glial tauopathy (GGT) is a rare 4R tauopathy with globular cytoplasmic inclusions within neurons and glial cells. Given the unique cellular distribution and morphology of tau pathology in GGT, we sought to determine if tau species in GGT had distinctive biological properties. To address this question, we performed seeding analyses with postmortem brain tissues using a commercial tau biosensor cell line. We found that brain lysates from GGT cases had significantly higher seeding competency than other tauopathies, including corticobasal degeneration (CBD), progressive supranuclear palsy (PSP), and Alzheimer’s disease (AD). The robust seeding activity of GGT brain lysates was independent of phosphorylated tau burden and diminished upon removal of tau from samples, suggesting that seeding properties were indeed mediated by tau in the lysates. In addition, cellular inclusions in the tau biosensor cell line induced by GGT had a distinct, globular morphology that was markedly different from inclusions induced by other tauopathies, further highlighting the unique nature of tau species in GGT. Characterization of different tau species in GGT showed that detergent-insoluble, fibril-like tau contained the highest seeding activity, as reflected in its ability to increase tau aggregation in primary glial cultures. Taken together, our data suggest that unique seeding properties differentiate GGT-tau from other tauopathies, which provides new insight into pathogenic heterogeneity of primary neurodegenerative tauopathies.

The non-structural protein μNS of piscine orthoreovirus (PRV) forms viral factory-like structures

Piscine orthoreovirus (PRV) is associated with heart- and skeletal muscle inflammation in farmed Atlantic salmon. The virus is ubiquitous and found in both farmed and wild salmonid fish. It belongs to the family Reoviridae, closely related to the genus Orthoreovirus. The PRV genome comprises ten double-stranded RNA segments encoding at least eight structural and two non-structural proteins. Erythrocytes are the major target cells for PRV. Infected erythrocytes contain globular inclusions resembling viral factories; the putative site of viral replication. For the mammalian reovirus (MRV), the non-structural protein μNS is the primary organizer in factory formation. The analogous PRV protein was the focus of the present study. The subcellular location of PRV μNS and its co-localization with the PRV σNS, µ2 and λ1 proteins was investigated. We demonstrated that PRV μNS forms dense globular cytoplasmic inclusions in transfected fish cells, resembling the viral factories of MRV. In co-transfection experiments with μNS, the σNS, μ2 and λ1 proteins were recruited to the globular structures. The ability of μNS to recruit other PRV proteins into globular inclusions indicates that it is the main viral protein involved in viral factory formation and pivotal in early steps of viral assembly.

Aquareovirus NS80 Recruits Viral Proteins to Its Inclusions, and Its C-Terminal Domain Is the Primary Driving Force for Viral Inclusion Formation

Cytoplasmic inclusion bodies formed in reovirus-infected cells are the sites of viral replication and assembly. Previous studies have suggested that the NS80 protein of aquareovirus may be involved in the formation of viral inclusion bodies. However, it remains unknown whether other viral proteins are involved in the process, and what regions of NS80 may act coordinately in mediating inclusion formation. Here, we observed that globular cytoplasmic inclusions were formed in virus-infected cells and viral proteins NS80 and NS38 colocalized in the inclusions. During transfection, singly expressed NS80 could form cytoplasmic inclusions and recruit NS38 and GFP-tagged VP4 to these structures. Further treatment of cells with nocodazole, a microtubule inhibitor, did not disrupt the inclusion, suggesting that inclusion formation does not rely on microtubule network. Besides, we identified that the region 530–742 of NS80 was likely the minimal region required for inclusion formation, and the C-tail, coiled-coil region as well as the conserved linker region were essential for inclusion phenotype. Moreover, with series deletions from the N-terminus, a stepwise conversion occurred from large condensed cytoplasmic to small nuclear inclusions, then to a diffused intracellular distribution. Notablely, we found that the nuclear inclusions, formed by NS80 truncations (471 to 513–742), colocalized with cellular protein β-catenin. These data indicated that NS80 could be a major mediator in recruiting NS38 and VP4 into inclusion structures, and the C-terminus of NS80 is responsible for inclusion formation.

Chronic lymphocytic leukemia cytoplasmic inclusions

American Journal of HematologyVolume 85, Issue 4 p. 275-276 Images in HematologyFree Access Chronic lymphocytic leukemia cytoplasmic inclusions† Namrata Setia, Namrata Setia Department of Pathology, Baystate Medical Center, Tufts University School of Medicine, Springfield, MassachusettsSearch for more papers by this authorTimothy Connolly, Timothy Connolly Department of Pathology, Baystate Medical Center, Tufts University School of Medicine, Springfield, MassachusettsSearch for more papers by this authorWilliam Levine, William Levine Department of Pathology, Baystate Franklin Medical Center, Tufts University School of Medicine, Springfield, MassachusettsSearch for more papers by this authorLiron Pantanowitz, Corresponding Author Liron Pantanowitz [email protected] Department of Pathology, Baystate Medical Center, Tufts University School of Medicine, Springfield, Massachusetts Department of Pathology, Baystate Franklin Medical Center, Tufts University School of Medicine, Springfield, MassachusettsDepartment of Pathology, Baystate Medical Center, 759 Chestnut Street, Springfield, MA 01199Search for more papers by this author Namrata Setia, Namrata Setia Department of Pathology, Baystate Medical Center, Tufts University School of Medicine, Springfield, MassachusettsSearch for more papers by this authorTimothy Connolly, Timothy Connolly Department of Pathology, Baystate Medical Center, Tufts University School of Medicine, Springfield, MassachusettsSearch for more papers by this authorWilliam Levine, William Levine Department of Pathology, Baystate Franklin Medical Center, Tufts University School of Medicine, Springfield, MassachusettsSearch for more papers by this authorLiron Pantanowitz, Corresponding Author Liron Pantanowitz [email protected] Department of Pathology, Baystate Medical Center, Tufts University School of Medicine, Springfield, Massachusetts Department of Pathology, Baystate Franklin Medical Center, Tufts University School of Medicine, Springfield, MassachusettsDepartment of Pathology, Baystate Medical Center, 759 Chestnut Street, Springfield, MA 01199Search for more papers by this author First published: 16 July 2009 https://doi.org/10.1002/ajh.21502Citations: 1 † Conflict of interest: Nothing to report. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1 McCann SR,Whelan A,Greally J. Intracellular lambda light chain inclusions in chronic lymphocytic leukaemia. Br J Haematol 1978; 38: 367– 371. 2 Ralfkiaer E,Hou-Jensen K,Geisler C, et al. Cytoplasmic inclusions in lymphocytes of chronic lymphocytic leukaemia. A report of 10 cases. Virchows Arch A Pathol Anat Histol 1982; 395: 227– 236. 3 Berrebi A,Talmor M,Vorst E, et al. IgM lambda globular cytoplasmic inclusions in chronic lymphocytic leukaemia resembling immunocytoma. Scand J Haematol 1983; 30: 43– 49. 4 Dorion RP,Shaw JH. Intracytoplasmic filamentous inclusions in the peripheral blood of a patient with chronic lymphocytic leukemia. A bright-field, electron microscopic, immunofluorescent, and flow cytometric study. Arch Pathol Lab Med 2003; 127: 618– 620. 5 Djaldetti M,Eisbruch A,Perek J,Hart J. Cytoplasmic inclusions and X-ray microprobe analysis in a case of prolymphocytic leukemia. J Cancer Res Clin Oncol 1984; 107: 229– 232. Citing Literature Volume85, Issue4April 2010Pages 275-276 ReferencesRelatedInformation

Plasma cells in bone marrow - an artifactual change mimicking metastasis.

Plasma cells are known to have a varied morphology espe-cially in plasma cell tumors [1]. They may be fl ame cells with deep magenta to pink cytoplasm at the periphery, or Mott cells with multiple small globular cytoplasmic inclu-sions or thesaurocytes which have reticulated cytoplasm [2, 3]. We present a case in which plasma cells showed a unusu-al morphology in trephine bone biopsy. A 40-year-old male presented with bony pain for two months, reduced appetite with fever of and on for a month. He had taken treatment for pulmonary tuberculosis one year back. On examination, he had pallor and a subcutaneous swelling on the anterior chest wall. There was no lymphadenopathy or hepato-splenomegaly. FNAC of the subcutaneous nodule revealed numerous plasma cells, suggestive of a plasmacytoma. Fur-ther investigations were done to rule out multiple myeloma. Hemogram revealed: hemoglobin – 10.3 g/dl, red blood cell count – 2.73 × 10

Astrocytic Inclusions in Epilepsy

We report the finding of unique astrocytic inclusions in a series of pediatric epilepsy patients, all of whom presented with seizures in their first year of life and had mild-to-moderate developmental delay. All eventually underwent surgical treatment for refractory epilepsy and, on pathological examination, were found to have distinctive, eosinophilic, globular cytoplasmic inclusions confined to cortical astrocytes. These inclusions were almost exclusively juxtanuclear, highly refractile, spared distal subpial, or perivascular astrocytic processes and were strongly and exclusively immunopositive for filamin A, an actin binding protein involved in neuronal migration. Identical inclusions have been identified and characterized in cases of Aicardi syndrome, a rare neurodevelopmental disease. The presence of the same inclusions in the cortex of epilepsy patients, some of whom had concomitant brain anomalies related to migrational problems, prompted us to consider that these patients may lie within a spectrum of disease involving dysfunction of filamin or filamin-interacting proteins. The term "filaminopathy" is tentatively proposed as a distinct pathological entity for this condition in which clinical manifestations range from epilepsy in mildly neurologically impaired patients to severe mental and physical handicap in the Aicardi syndrome. Future studies will be necessary to unravel the exact nature of the filamin A protein or gene aberrations in these patients.

Primary pleural epithelioid hemangioendothelioma with rhabdoid phenotype: Report and review of the literature

Epithelioid hemangioendothelioma (EHE) is a rare malignant vascular tumor described in diverse locations including lung and liver. Relative to these sites, primary EHE of the serous cavities is uncommon. EHE in the serous cavities mimics mesothelioma and adenocarcinoma clinically, radiographically, cytologically, and histologically. EHEs have plasmacytoid epithelioid cells with cytoplasmic vacuoles. In addition to these features, we noted eccentric nuclei with abundant eosinophilic cytoplasm and nuclei displaced peripherally by globular cytoplasmic inclusions imparting a "rhabdoid" phenotype. These cells were often seen surrounding a hyaline core. Rhabdoid features are not unique to a single entity, and a comprehensive immunohistochemical panel is essential. We report the occurrence of pleural EHE with rhabdoid features presenting in a pleural effusion, and review the literature of primary serosal EHEs.

Fibrinogen Gamma375 Arg→Trp Mutation (Fibrinogen Aguadilla) Causes Hereditary Hypofibrinogenemia, Hepatic Endoplasmic Reticulum Storage Disease and Cirrhosis

Hypofibrinogenemia is a rare inherited disorder characterized by low levels of circulating fibrinogen, caused by mutations within 1 of the 3 fibrinogen genes. We report here the case of a 61-year-old man with chronic liver function test alterations. Liver biopsy examination revealed chronic hepatitis complicated by cirrhosis and weakly eosinophilic globular cytoplasmic inclusions within the hepatocytes, faintly stained with PAS-diastase. On immunohistochemistry, the inclusions reacted strongly with human antifibrinogen antibodies. Coagulation investigations of the propositus and his 2 sons showed low functional and antigenic fibrinogen concentrations that were indicative of hypofibrinogenemia. A liver biopsy performed on the 28-year-old son demonstrated the same globular cytoplasmic inclusions, albeit without associated chronic liver disease. PCR amplification followed by sequencing showed that all 3 were heterozygous for a CGG>TGG mutation at codon 375 of the fibrinogen gamma-chain gene (FGG), corresponding to an Arg>Trp substitution. This is the first in an adult male and the second published case with a discernible hepatic fibrinogen endoplasmic reticulum storage disease due to an FGG Arg375Trp (fibrinogen Aguadilla) mutation. Our results suggest that familial hypofibrinogenemia should be considered in the differential diagnosis of a progressive liver disease associated to hepatocellular intracytoplasmic globular inclusions.

Avian reovirus nonstructural protein μNS forms viroplasm-like inclusions and recruits protein σNS to these structures

The M3 genome segment of avian reovirus 1733, which encodes the nonstructural protein μNS, is 1996 nucleotides long and contains a long open reading frame that is predicted to encode a polypeptide of 635 amino acid residues. Examination of the deduced amino acid sequence of μNS revealed the presence of two regions near its carboxyl terminus with a high probability of forming α-helical coiled coils. Expression of the M3 gene in both infected and transfected cells revealed that this gene specifies two protein isoforms that are recognized by a μNS-specific antiserum. Only the larger μNS isoform, but not the smaller one, interacts with the nonstructural protein σNS in infected cells, suggesting that the two isoforms play different roles during avian reovirus infection. In the second part of this study, we show that μNS and the nonstructural protein σNS colocalize throughout the viral life cycle in large and small phase-dense globular cytoplasmic inclusions, which are believed to be the sites of viral replication and assembly. Individual expression of these proteins in transfected cells of avian and mammalian origin revealed that while μNS is able to form inclusions in the absence of other viral proteins, σNS distributes diffusely throughout the cytoplasm in the absence of μNS. These data suggest that μNS is the minimal viral factor required for inclusion formation during avian reovirus infection. On the other hand, our findings that σNS associates with μNS in infected cells, and that σNS colocalizes with μNS in viroplasm-like inclusions when the two proteins are coexpressed in transfected cells, suggest that μNS mediates the association of σNS to inclusions in avian reovirus-infected cells.

Evidence for B-cell origin of reticulum cell sarcoma.

Sixteen cases of so-called reticulum cell sarcoma (RCS) of the lymph node were systematically studied using histological, cytochemical, electron microscopic, and immunochemical methods. In 8 cases some of the tumor cells showed PAS-positive globular cytoplasmic inclusions. The reactions for non-specific esterase or other marker enzymes were not positive in any case. Electron microscopically the cytoplasm contained many free polyribosomes. There was little ergastoplasm in most cases, but a moderately to strongly increased amount in 3 cases. The tumor tissue homogenate contained significantly increased amounts of IgM in 12 cases and of IgA in one case. Of the 12 IgM-positive RCS 5 showed serum IgM-levels within, 3 below, and only 2 above the normal range. This indicates that most of the RCS produced but did not secrete IgM. 2 cases labeled for surface-IgM revealed a positive reaction on a large number of tumor cells. We conclude that at least most of the RCS in our study were not derived from reticulum cells or histiocytes, but instead from lymphatic cells of the B-cell series. The morphologic similarity of the RCS-cells to “antigen-induced blasts” (called immunoblasts) suggests that RCS are derived from such blasts. This interpretation is especially supported by one case whose cells resembled immunoblasts not only morphologically but also with respect to the site of Ig-production: the perinuclear space. In general we therefore call RCS immunoblastic sarcoma of B-cell type and specify the tumor as plasmoblastic sarcoma if a significant amount of ergastoplasm is electron microscopically detectable.