scholarly journals Electron Microscopic Study on the Hepatic Sinusoidal Wall of the Soft-Shelled Turtle (Amyda japonica) with Special Remarks on the Smooth Muscle Cells

1987 ◽  
Vol 50 (3) ◽  
pp. 251-272
Author(s):  
Yutaka TANUMA
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Muscle Cells ◽  
Electron Microscopic ◽  
Sinusoidal Wall

Abstract WMP31: Dedifferentiation of Smooth Muscle Cells and its Potential Contribution to Pathogenesis of Intracranial Aneurysms

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Mieko Oka ◽  
Nobuhiko Ohno ◽  
Takakazu Kawamata ◽  
Tomohiro Aoki
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Inflammatory Responses ◽  
Muscle Cells ◽  
Inflammatory Factors ◽  
Potential Contribution ◽  
Electron Microscopic

Introduction: Intracranial aneurysm (IA) affects 1 to 5 % in general public and becomes the primary cause of subarachnoid hemorrhage, the most severe form of stroke. However, currently, no drug therapy is available for IAs to prevent progression and rupture of lesions. Elucidation of mechanisms underlying the disease is thus mandatory. Considering the important role of vascular smooth muscle cells (SMCs) in the maintenance of stiffness of arterial walls and also in the pathogenesis of atherosclerosis via mediating inflammatory responses, we in the present study analyzed morphological or phenotypical changes of SMCs during the disease development in the lesions. Methods: We subjected rats to an IA model in which lesions are induced by increase of hemodynamic force loading on intracranial arterial bifurcations and performed histopathological analyses of induced lesions including the electron microscopic examination. We then immunostained specimens from induced lesions to explore factors responsible for dedifferentiation or migration of SMCs. In vitro study was also done to examine effect of some candidate factors on dedifferentiation or migration of cultured SMCs. Results: We first found the accumulation of SMCs underneath the endothelial cell layer mainly at the neck portion of the lesion. These cells was positive for the embryonic form of myosin heavy chain, a marker for the dedifferentiated SMCs, and the expression of pro-inflammatory factors like TNF-α. In immunostaining to explore the potential factor regulating the dedifferentiation of SMCs, we found that Platelet-derived growth factor-BB (PDGF-BB) was expressed in endothelial cells at the neck portion of IA walls. Consistently, recombinant PDGF-BB could promote the dedifferentiate of SMCs and chemo-attracted them in in vitro. Finally, in the stenosis model of the carotid artery, PDGF-BB expression was induced in endothelial cells in which high wall shear stress was loaded and the dedifferentiation of SMCs occurred there. Conclusions: The findings from the present study imply the role of dedifferentiated SMCs partially recruited by PDGF-BB from endothelial cells in the formation of inflammatory microenvironment at the neck portion of IA walls, leading to the progression of the disease.

scholarly journals CENTRIOLES AND THE FORMATION OF RUDIMENTARY CILIA BY FIBROBLASTS AND SMOOTH MUSCLE CELLS

1962 ◽  
Vol 15 (2) ◽  
pp. 363-377 ◽  
Author(s):  
Sergei Sorokin
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Sensory Function ◽  
Second Phase ◽  
Electron Microscopic ◽  
Internal Development ◽  
Whole Process ◽  
Third Phase ◽  
Mammalian Tissues

Cells from a variety of sources, principally differentiating fibroblasts and smooth muscle cells from neonatal chicken and mammalian tissues and from organ cultures of chicken duodenum, were used as materials for an electron microscopic study on the formation of rudimentary cilia. Among the differentiating tissues many cells possessed a short, solitary cilium, which projected from one of the cell's pair of centrioles. Many stages evidently intermediate in the fashioning of cilium from centriole were encountered and furnished the evidence from which a reconstruction of ciliogenesis was attempted. The whole process may be divided into three phases. At first a solitary vesicle appears at one end of a centriole. The ciliary bud grows out from the same end of the centriole and invaginates the sac, which then becomes the temporary ciliary sheath. During the second phase the bud lengthens into a shaft, while the sheath enlarges to contain it. Enlargement of the sheath is effected by the repeated appearance of secondary vesicles nearby and their fusion with the sheath. Shaft and sheath reach the surface of the cell, where the sheath fuses with the plasma membrane during the third phase. Up to this point, formation of cilia follows the classical descriptions in outline. Subsequently, internal development of the shaft makes the rudimentary cilia of the investigated material more like certain non-motile centriolar derivatives than motile cilia. The pertinent literature is examined, and the cilia are tentatively assigned a non-motile status and a sensory function.

scholarly journals Myocardin is differentially required for the development of smooth muscle cells and cardiomyocytes

2011 ◽  
Vol 300 (5) ◽  
pp. H1707-H1721 ◽  
Author(s):  
Mark H. Hoofnagle ◽  
Ronald L. Neppl ◽  
Erica L. Berzin ◽  
G. C. Teg Pipes ◽  
Eric N. Olson ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Ventricular Myocytes ◽  
Embryoid Body ◽  
Embryonic Stem ◽  
Muscle Cells ◽  
Atrial Myocytes ◽  
Electron Microscopic ◽  
Virtual Absence ◽  
Vascular Smcs

Myocardin is a serum response factor (SRF) coactivator exclusively expressed in cardiomyocytes and smooth muscle cells (SMCs). However, there is highly controversial evidence as to whether myocardin is essential for normal differentiation of these cell types, and there are no data showing whether cardiac or SMC subtypes exhibit differential myocardin requirements during development. Results of the present studies showed the virtual absence of myocardin−/− visceral SMCs or ventricular myocytes in chimeric myocardin knockout (KO) mice generated by injection of myocardin−/− embryonic stem cells (ESCs) into wild-type (WT; i.e., myocardin+/+ ESC) blastocysts. In contrast, myocardin−/− ESCs readily formed vascular SMC, albeit at a reduced frequency compared with WT ESCs. In addition, myocardin−/− ESCs competed equally with WT ESCs in forming atrial myocytes. The ultrastructural features of myocardin−/− vascular SMCs and cardiomyocytes were unchanged from their WT counterparts as determined using a unique X-ray microprobe transmission electron microscopic method developed by our laboratory. Myocardin−/− ESC-derived SMCs also showed normal contractile properties in an in vitro embryoid body SMC differentiation model, other than impaired thromboxane A2 responsiveness. Together, these results provide novel evidence that myocardin is essential for development of visceral SMCs and ventricular myocytes but is dispensable for development of atrial myocytes and vascular SMCs in the setting of chimeric KO mice. In addition, results suggest that as yet undefined defects in development and/or maturation of ventricular cardiomyocytes may have contributed to early embryonic lethality observed in conventional myocardin KO mice and that observed deficiencies in development of vascular SMC may have been secondary to these defects.

Quantitative electron microscopic study on mitochondria of smooth muscle in piqixuzheng rat

1990 ◽  
Vol 48 (3) ◽  
pp. 482-483
Author(s):  
Hepei Liu ◽  
Yanming Hou ◽  
Xiaofeng Chang ◽  
Shulan Wang
Keyword(s):  
Smooth Muscle ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Normal Structure ◽  
Electron Microscopic ◽  
Energy Deficiency ◽  
Abnormal Structure ◽  
Modern Technique ◽  
Male Wistar Rats ◽  
Magnolia Officinalis

Johnson stated that man has always been interested in the structure of things in the world around him. In this regard, the electron microscopy, a modern technique, is used for research in traditional Chinese medicine. The terms and theories of TCM are quite different from those of Western medicine. The theory of TCM indicates that pi (spleen in TCM) has important roles in human health. According to the basic theory of TCM, one such function of the pi is nourishing the muscles. A significant decrease in the number of mitochondria with normal structure and a significant increase in the number of mitochondria with abnormal structure in skeletal muscle of piqixuzheng (spleen energy deficiency in TCM) rats have been reported. The present work is a quantitative electron microscopic study on mitochondria of smooth muscle in piqixuzheng rats.Male Wistar rats were used in this study. The piqixuzheng rats were produced by treatment with houpo (Magnolia officinalis), Zhishi(Fructus aurantii immaturus), dahuang (Radix et rhizoma) and fasting day other day for six weeks.

scholarly journals Analytical electron microscopic study of mitochondrial inclusions in canine myocardial infarcts.

1976 ◽  
Vol 24 (3) ◽  
pp. 508-516 ◽  
Author(s):  
L M Buja ◽  
J H Dees ◽  
D F Harling ◽  
J T Willerson
Keyword(s):  
Electron Microscopy ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Mitochondrial Protein ◽  
Analytical Electron Microscopy ◽  
Muscle Cells ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Mitochondrial Inclusions ◽  
Analytical Electron

An analytical electron microscopic study, utilizing scanning transmission electron microscopy and energy-dispersive x-ray spectroscopy, was made of two types of mitochondrial inclusions identified in canine myocardial infarcts. The data were obtained from thin sections of tissues that were fixed in aldehyde, osmicated and embedded in epoxy resin. Calcium peaks of variable intensity were detected in inclusions which contained very electron-dense spicular material and which were localized to muscle cells at the peripheries of the infarcts. These findings indicate that the spicular inclusions represent early stages in the process of mitochondrial calcification in myocardial infarcts. In contrast, calcium or other trace elements were not detected in moderately electron-dense amorphous inclusions which were present in mitochondria of muscle cells throughout the infarcts. With the tissue preparative techniques employed, the possibility cannot be excluded that the amorphous inclusions contained calcium, either in small amounts or in a readily diffusable state, in vivo. The data, however, are in accord with the previously advanced hypothesis that the amorphous inclusions represent precipitates of denatured mitochondrial protein formed during the evolution of irreversible cellular injury. This study provides further evidence that analytical electron microscopy can yield important information regarding the nature of various inclusions occurring in normal and diseased tissues.

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