Emperipolesis — a peculiar feature of megakaryocytes as evaluated in chronic myeloproliferative diseases by morphometry and ultrastructure

Thiele, Jürgen; Krech, Rainer; Choritz, H.; Georgii, A.

doi:10.1007/bf02890314

Cited by 34 publications

(23 citation statements)

References 10 publications

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“…engulfing of various BM cells by megakaryocytes [40], was also frequently observed in this study. Emperipolesis increases in various disorders, including multiple myeloma, carcinoma, lymphoma [41], platelet disorders [42] and serious hemorrhage [43], however the pathophysiological importance of emperipolesisis is yet to be fully understood and its significance is uncertain [44,45].…”

Section: (12)supporting

confidence: 82%

Evaluation of blood and bone marrow in selected canine vector-borne diseases

Tommasi

Otranto

Furlanello

et al. 2014

Parasites & Vectors

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Background: Bone marrow (BM) is a major hematopoietic organ that can harbour a variety of vector-borne pathogens; however, knowledge of BM pathological changes in dogs infected with vector-borne pathogens is limited. Thus, the aim of the present study was to assess the pathological changes in canine BM associated with natural infections by four vector-borne pathogens, as well as to determine the relationships between such changes and abnormalities of the peripheral blood.

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Section: (12)supporting

confidence: 82%

Evaluation of blood and bone marrow in selected canine vector-borne diseases

Tommasi

Otranto

Furlanello

et al. 2014

Parasites & Vectors

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“…Of course, it has to be emphasized that other giant bone marrow cells, the osteoclasts, which are also migrant, never show comparable cellular inclusions [5]. The strongest argument against the above statement is that emperipolesis is clearly related to thrombopoiesis, namely to normal active production as well as to its abnormal increase, such as in myeloproliferation [5,7,25,26]. In such a case, the extended demarcation membrane system, where engulfed cells are located, could provide enough cytoplasmic space for packing other cells.…”

Section: Discussionmentioning

confidence: 96%

Emperipolesis of marrow cells within megakaryocytes in the bone marrow of sublethally irradiated mice

Bobik

Dabrowski

1995

Ann Hematol

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The incidence of megakaryocytic emperipolesis was studied in the bone marrow of normal and X-irradiated mice. Two groups of mice received total body irradiation with a single dose of 5 Gy and one of the two groups had been treated with a radioprotective drug, ethiofos (WR-2721), before irradiation. Mice from a third group remained unexposed to irradiation and served as controls. The Wright-Giemsa stained bone marrow smears were analyzed every 5 days during a 30-day period, starting 1 day after irradiation. The number of megakaryocytes exhibiting the phenomenon was determined and expressed as an average value for every experimental group. The frequency of megakaryocytic emperipolesis was less than 15% of megakaryocytes from control smears but increased to 34% in mice that had only been irradiated and to 43% when mice were treated with WR-2721 before irradiation. In the last case, i.e., irradiation and treatment with a radioprotective drug, a positive correlation between the macrocytic megakaryocytes and elevated emperipolesis was noted. Under light microscopy, there were no signs of phagocytosis; engulfed cells remained unaltered with their normal structure intact. Granulocytic, erythroid, and lymphoid cells appeared to be the most frequent marrow cells engulfed by mature megakaryocytes. The number of incorporated cells in one megakaryocyte ranged from 1 to 3, though occasionally more than 6 were seen in macrocytic megakaryocytes. Based on our findings and on a review of the associated literature, we believe emperipolesis is an interesting cellular phenomenon related to the fast passage of marrow cells across the marrow-blood barrier, especially through the cytoplasm of megakaryocytes in response to an increased demand for cell delivery. The high demand for cell delivery which occurs after irradiation may cause certain mature bone marrow cells to take a transmegakaryocyte path to enter the circulation of the blood. Irradiation seems to have an immediate effect (observed after 24 h) on emperipolesis, suggesting that a humoral factor is involved in the pathogenesis.

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“…As shown in Figure 7A-B, large mature megakaryocytes were easily recognized, and some of these megakaryocytes exhibited multifocal emperipolesis of neutrophils (arrows in Figure 7C), suggesting enhanced thrombocytogenetic activity. 36 The absolute number of high ploidy megakaryocytes in the BM from Abcg8 2/2 mice fed an HS diet (67 6 18/mm 2 , n 5 4) was about 2 times higher than that from Abcg8 2/2 mice fed an LS diet (28 6 10/mm 2 , n 5 4). Because mature megakaryocytes derived from Abcg8 2/2 HS are fragile, they were isolated using anti-CD41 magnetic beads and cultured in vitro for 60 hours in the presence of mouse thrombopoietin before performing ploidy analysis.…”

Section: Megakaryocytopoiesis In Abcg8mentioning

confidence: 91%

Platelet hyperreactivity explains the bleeding abnormality and macrothrombocytopenia in a murine model of sitosterolemia

Kanaji

Montgomery

et al. 2013

Blood

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• Plant sterol accumulation in platelet membrane induces platelet hyperreactivity.• Internalization of the aIIbb3 complex and filamin A degradation cause macrothrombocytopenia and bleeding phenotype.Sitosterolemia is a rare, autosomal recessive disease caused by mutations in the adenosine triphosphate-binding cassette transporter genes ABCG5 or ABCG8 that result in accumulation of xenosterols in the body. Clinical manifestations include tendon xanthomas, premature coronary artery disease, hemolytic anemia, macrothrombocytopenia, and bleeding. Although the effect of sterol accumulation on the predisposition for atherosclerosis is evident, how xenosterol accumulation leads to defects in platelet physiology is unknown. Sitosterolemia induced in Abcg5-and Abcg8-deficient mice fed a high plant sterol diet resulted in accumulation of free sterols in platelet plasma membranes, leading to hyperactivatable platelets characterized by constitutive binding of fibrinogen to its aIIbb3 integrin receptor, internalization of the aIIbb3 complex, generation of plateletderived microparticles, and changes in the quantity and subcellular localization of filamin. The latter was associated with macrothrombocytopenia, shedding of GPIba, impaired platelet adhesion to von Willebrand factor, and inability to form stable thrombi. Plasma levels of soluble GPIba were strongly correlated with plasma sitosterol levels in samples from human sitosterolemic patients, implicating a similar mechanism of sterol-induced platelet passivation in the human disease. Intercalation of plant sterols into the plasma membrane therefore results in dysregulation of multiple platelet activation pathways, leading to macrothrombocytopenia and bleeding. (Blood. 2013;122(15):2732-2742

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Emperipolesis — a peculiar feature of megakaryocytes as evaluated in chronic myeloproliferative diseases by morphometry and ultrastructure

Cited by 34 publications

References 10 publications

Evaluation of blood and bone marrow in selected canine vector-borne diseases

Evaluation of blood and bone marrow in selected canine vector-borne diseases

Emperipolesis of marrow cells within megakaryocytes in the bone marrow of sublethally irradiated mice

Platelet hyperreactivity explains the bleeding abnormality and macrothrombocytopenia in a murine model of sitosterolemia

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