Tokuhiro JSHIHARA, Chotatsu TSUKAYAMA, Fumiya UCHINO

Transcription

1 (39) JOURNAL OF ELECTRON MICROSCOPY 39 Vol. 22, No. I, 39-44, 1973 Intramitochondrial Filamentous Structures in Human Reticulum Cells in the Bone Marrow Tokuhiro JSHIHARA, Chotatsu TSUKAYAMA, Fumiya UCHINO and Noboru MATSUMOTO* First Department ofpathology, 'Third Department of Internal Medicine, Yamaguchi University School of Medicine, Ube, Japan (Received August 31, 1972) Intramitochondrial filamentous structures with an approximate thickness of 40 to 80 A and helical rearrangement of the mitochondria! cristae have been incidentally noted In the giant mitochondria of human reticulum cells in the bone marrow obtained from a patient with disseminated mlllary tuberculosis. As a possible origin of these structures, transformation from the mitochondrial cristae has been suggested but their biological significance remains to be elucidated. PREFACE Peculiar intramitochondrial filamentous bodies have been reported in the various types of cells and they were listed up by Suzuki and Mostofi, 11 who classified these bodies according to their location and morphological characteristics. As far as the authors reviewed the recent literatures, intramitochondrial filaments have never been found in the human reticulum cells. It seems to be worthwhile to describe the morphological features of peculiar filaments incidentally observed in the reticulum cells in the bone marrow and to discuss their origin and significance. MATERIALS AND METHODS The bone marrow specimen was obtained from a patient with disseminated miliary tuberculosis. The brief clinical course of this patient was as follows: A patient (77-year-old male) with a chief complaint of epistaxis was first seen in May, Examination of the peripheral blood disclosed giant platelets and occasional Dohle bodies in the neutrophils, and May-Hegglin's anomaly was suspected. Two months prior to admission, he began to have cough and fever and in August, 1970, he admitted because of increasing dyspnea. The leukocyte count was 13,000/cumm. with marked neutrophilia (N. band 21.5%, N. seg. 65%). The bone marrow aspiration revealed hypercellularity with increased myeloblasts (9.3%) and progranulocytes (11.3%) indicating leukemoid reaction. Administration of antibiotics was not effective and he expired several days later. Autopsy disclosed milialy tuberculosis involving the pericardium, pleura, diaphragma, spleen, liver and lymph nodes. For electron microscopic examination, aspirated marrow tissue was immediately fixed in 4.15% glutaraldehyde and osmium tetraoxide, dehydrated in the graded ethanol and embedded in epoxy resin according to the method of Luft. 1 ' Thin sections cut with Ivan Sorvall ultramicrotome were doubly stained with uranyl acetate and lead citrate. These sections were examined and photographed in a Hitachi HS-8 electron microscope. OBSERVATIONS The filamentous structures were exclusively observed in the giant mitochondria of the

2 40 T. ISHIHARA, C. TSUKAYAMA, F. UCHINO and N. MATSUMOTO (40) reticulum cells, though the occurrence of such mitochondria was not frequent. The cells containing such giant mitochondria had abundant cytoplasm in which moderate amounts of endoplasmic reticulum and occasional phagosomes were noted. Early granular formation and specific granules were not observed in their cytoplasm. From the cytoplasmic characteristics, these cells were identified as the reticulum cells. Figure 1 shows a reticulum cell containing one giant mitochondrion. Other mitochondria are all round in shape with an approximate diameter of 400 m/i. The giant mitochondria are usually located near the nucleus and their length is ranged from 3 to 4 /< and their width 800 m/«to 2 p. Figure 2 illustrates the high magnification of the giant mitochondrion in longitudinal section shown in Fig. 1. Short mitochondrial cristae are arranged at the peripheral portion. The tubular cristae forming strand are arranged along the long axis and at the left lower area cristae show marked cystic distension. Fine filamentous structures in the matrix are arranged not only parallel to the long axis of the mitochondria but at right angle to the long axis. High magnification of another giant mitochondrion in longitudinal section shown in Fig. 3 reveals three strands of helically arranged mitochondrial cristae along the long axis. Fn this mitochondrion, filamentous structures are not prominent. Figure 4 shows another giant mitochondrion in longitudinal section. The mitochondrial cristae are only visible at the peripheral portion. Fn the central portion of the matrix, abundant filamentous structures with an approximate thickness of 40 to 80 A are arranged not only roughly parallel to the long axis but in the direction perpendicular to the long axis. In frequent areas, continuation between the filaments arranged at a right angle to the long axis and the cristal membrane (arrow) are clearly visible. In Fig. 5, transverse aspects of a giant mitochondrion with intramatrical filamentous structures are demonstrated. Short mitochondrial cristae are located at the peripheral area and strands of helically arranged cristae seem to be cut nearly crossly. Around these strands, dense granules with an average diameter of 60 A are observed and these granules seem to be sectional profils of the filaments. Oblique section of a giant mitochondrion shown in Fig. 6 reveals helical arrangement of mitochondrial cristae and intramatrical filamentous structures are not clear in this picture. DISCUSSION Reviewing the literatures on the intramitochondrial filamentous bodies, Suzuki and Mostofi" have divided them into two main categories; those occuring in the matrix and those in the intracristal space or the space between the outer and inner mitochondrial membrane. The filamentous structure reported here belong to the former group. The most frequent cell types in which such structures have been observed are the hepatic cells'" 81 and kidney tubules 1 ''' 101 in either normal or pathological conditions. This report seems to be the first description on the intramitochondrial filaments in the human reticulum cells in the bone marrow. Suzuki and Mostofi" recognized three types of intramitochondrial filamentous bodies in the tubular epithelia of the thick limb of Henle. Type I was consisted of an accumulation of dense and smooth filamentous structures with an average diameter of 55 A, occuring in the long axis of a mitochondrion and displacing the cristae. Type II was consisted of a bundle of parallel filaments with the same thickness of type F, and type IIF intramitochondrial filaments were consisted of type II with irregular light bands of 280 A periodicity and helical border of prismatic tubular cristae. They suggested a possible origin of these filamentous bodies from mitochondrial cristae and possible development of type I to intermediate form of type IF and

3 (41) Intramitochondrial Filaments in Reticulum Cells 41 finally to type 11F. The filamentous structures described in this communication are almost similar to type I in their location and morphology, but a bundle of parallel filaments is not observed. Strands of helically arranged mitochondrial cristae shown in Fig. 3 have some morphological resemblance to the type JII bodies reported by Suzuki and Mostofi, 11 but the constituent filaments surrounded by mitochondrial cristae in helical fashion are not clear in our observation. Continuation between the filamentous structures and mitochondrial cristae shown in Fig. 4 suggests a possible origin of these structures from mitochondrial cristae as has been postulated by Suzuki and Mostofi. 1 ' EXPLANATION OF FIGURES Infection (miliary tuberculosis) might have played some causative role in the occurrence of intramitochondrial filamentous bodies and rearrangement of the mitochondrial cristae forming the strands along the long axis of the mitochondria, though exact origin and significance of these structures remain unknown. Occurrence of these structures exclusively in the giant mitochondria seems to indicate the associated transformation of the mitochondria into the giant form as the result of an accumulation of filamentous structures in the matrix, and such transformation may suggest a specialized metabolic activity of the mitochondria in certain pathological conditions. REFERENCES 1) Suzuki, T. and Mostofi, F. K., /. Cell Biol., 33, 605 (1967) 2) Luft, J.H., /. Biophys. Biochem. Cytol., 9, 409 (1961) 3) Mugnaini, E., /. Ullrastrnc. Res., 11, 525 (1964) 4) Porta, E. A. et al., Lab. Invest., 14, 1437 (1965) 5) Reichel, J. et al., Am. J. Med., 28, 654 (1960) 6) Schaffner, F. et al., Am. J. Med. Assoc, 183, 343 (1963) 7) Svoboda, D. J. and Manning, R. T., Am. J. Path., 44, 645 (1964) 8) Wills, E. J., /. Cell Biol., 24, 5] 1 (1965) 9) Battifora, H. et al., Am. J. Path., 48, 412 (1966) 10) Ebe, T. et al., J. Electronmicroscopy (Tokyo), 14, 203 (1965) Fio. 1. A giant mitochondrion in reticulum cell, x 12,500 FIG. 2. High magnification of a giant mitochondrion shown in Fig. 1. Short mitochondrial cristae are arranged at the peripheral area. The filamentous structures are arranged not only parallel to the long axis of the mitochondria but also in the direction across these filaments. Two strands of rearranged cristae are also observed, x 27,600 FIG. 3. High magnification of another giant mitochondrion with helically rearranged mitochondrial cristae forming strands. Filamentous structures in the matrix are not prominent, x 48,300 Fio. 4. High magnification of another giant mitochondrion with intramatrical filamentous structures which run parallel or perpendicular to the long axis. In some areas continuation between intramitochondrial filaments and cristal membrane are noted (arrow), x 84,000 Fia. 5. Transverse aspect of a giant mitochondrion which shows accumulation of granules with an average diameter of 60 A around the rearranged mitochondrial cristae. x 48,300 FIG. 6. A giant mitochondrion with strands of helically arranged mitochondrial cristae probably in oblique aspect. Intramitochondrial filaments are not prominent in this figure. X 27,600

4 41 T. ISHIHARA, C. TSUKAYAMA, F. UCHINO and N. MATSUMOTO (425 * ' *"*< :

5 (43) Intramitochondrial Filaments in Reticulum Cells 43

6 44 T. ISHIHARA, C. TSUKAYAMA, F. UCHINO and N. MATSUMOTO (44) % - i-