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Mitochondria showing abnormal circular cristae within degenerate myocytes (original magnification, ×29 500).
Source publication
To review and reassess the role of this department's experience with routine electron microscopy of myocardial tissues.
A nine year series of myocardial samples that underwent electron microscopy analysis were audited. Fifty nine samples were derived from 46 male and 13 female subjects with an age range of 15-90 years (mean, 50.6). Forty two sample...
Context in source publication
Context 1
... sample showed the characteristic light and dark degenerative changes of basophilic degenera- tion ( fig 4). A single case with abnormal myofi- bre degeneration and atypical mitochondria was seen in a patient with dilated cardiomyopa- thy, and was interpreted as a putative mito- chondrial myopathy ( fig 5). However, this patient recovered from his dilated, dysrhythmic status to the point where he was able to resume normal activities. ...
Citations
... At the ultrastructural level, abnormal mitochondria in diseased human myocardial tissue mainly present with atypical cristae organization, a significant variation in organelle size and even with mitochondrial inclusions [47]. These structural alterations are typically associated with a reduced capacity to generate ATP (oxidative phosphorylation) and are a major source of ROS production as detailed before (see, giant mitochondria in ageing heart), which can induce cellular damage resulting in cell death and disease progression. ...
Giant mitochondria are frequently observed in different disease models within the brain, kidney, and liver. In cardiac muscle, these enlarged organelles are present across diverse physiological and pathophysiological conditions including in ageing and exercise, and clinically in alcohol-induced heart disease and various cardiomyopathies. This mitochondrial aberration is widely considered an early structural hallmark of disease leading to adverse organ function. In this thematic paper, we discuss the current state-of-knowledge on the presence, structure and functional implications of giant mitochondria in heart muscle. Despite its demonstrated reoccurrence in different heart diseases, the literature on this pathophysiological phenomenon remains relatively sparse since its initial observations in the early 60s. We review historical and contemporary investigations from cultured cardiomyocytes to human tissue samples to address the role of giant mitochondria in cardiac health and disease. Finally, we discuss their significance for the future development of novel mitochondria-targeted therapies to improve cardiac metabolism and functionality.
... Routine clinical follow-up protocols use EMB for the assessment of ACR by classical histology since no other method of structural tissue analysis has been proven as clinically relevant in the care of HTx recipients. Electron microscopy (EM) has been used for research purposes in patients with allograft rejection, and it did not add to the clinical decision process for these patients (21,22). Conversely, EM is routinely used in the analysis of kidney biopsies, both for establishing the etiology of disease, as well as in surveillance of renal graft rejection (23). ...
Endomyocardial biopsies are the gold standard for surveillance of graft rejection following heart transplantation, and are assessed by classical histopathology using a limited number of previously stained slices from several biopsies. Synchrotron propagation-based X-ray phase contrast imaging is a non-destructive method to image biological samples without tissue preparation, enabling virtual 2D and 3D histopathology. We aimed to show the feasibility of this method to assess acute cellular rejection and its agreement to classical histopathology. Right ventricular biopsies were sampled from 23 heart transplantation recipients (20 males, mean age 54±14 years) as part of standard follow-up. The clinical diagnosis of potential rejection was made using classical histopathology. One additional study sample was harvested and imaged by X-ray phase contrast imaging, producing 3D datasets with 0.65 μm pixel size, and up to 4,320 images per sample. An experienced pathologist graded both histopathological and X-ray phase contrast images in a blinded fashion. The agreement between methods was assessed by weighted kappa, showing substantial agreement (kappa up to 0.80, p < 0.01) between X-ray phase contrast imaging and classical histopathology. X-ray phase contrast imaging does not require tissue processing, allows thorough analysis of a full myocardial sample and allows identification of acute cellular rejection.
... Routine histological stains for light microscopy may be supplemented by special staining techniques, immunohistochemistry and electron microscopy. 80,81 Basic and advanced morphometric studies can be performed on histological sections of cardiac tissue with the help of different software for image analysis. 13 Histologically, lipid accumulation in the myocardium can be seen as intracellular lipid accumulation in myocytes (myocardial steatosis and lipotoxic cardiomyopathy) or as clusters of adipocytes (intramyocardial adipose tissue). ...
Visceral adipose tissue is an independent risk factor for the development of atherosclerotic coronary disease, arterial hypertension, diabetes and metabolic syndrome. Right heart morphology often involves the presence of adipose tissue, which can be quantified by non-invasive imaging methods. The last decade brought a wealth of new insights into the function and morphology of adipose tissue, with great emphasis on its role in the pathogenesis of heart disease. Cardiac adipose tissue is involved in thermogenesis, mechanical protection of the heart and energy storage. However, it can also be an endocrine organ that synthesises numerous pro-inflammatory and anti-inflammatory cytokines, the effect of which is accomplished by paracrine and vasocrine mechanisms. Visceral adipose tissue has several compartments that differ in their embryological origin and vascularisation. Deficiency of cardiac adipose tissue, often due to chronic pathological conditions such as oncological diseases or chronic infectious diseases, predicts increased mortality and morbidity. To date, knowledge about the influence of visceral adipose tissue on cardiac morphology is limited, especially the effect on the morphology of the right heart in a state of excess or deficient visceral adipose tissue.
... Immunofluorescent microscopy can be used to identify pathological changes, such as disorganised myofilaments, by staining with antibodies specific to the sarcomeric proteins (e.g., sarcomeric α-actinin and cardiac-troponin-T) [32]. Electron microscopy with a resolution power of 50-200 pm can also identify phenotypic changes at an ultra-structural level [80]. Abnormalities in membranous structures, as well as glycogen granule accumulation, can be revealed, and are extremely useful in the evaluation of cardiac defects resulting from protein aggregation, autophagic dysfunction (Danon disease), and dysregulated intracellular storage (Danon disease and Fabry disease). ...
Abstract: Inherited cardiomyopathies are among the major causes of heart failure and associated with significant mortality and morbidity. Currently, over 70 genes have been linked to the etiology of various forms of cardiomyopathy, some of which are X-linked. Due to the lack of appropriate cell and animal models, it has been difficult to model these X-linked cardiomyopathies. With the advancement of induced pluripotent stem cell (iPSC) technology, the ability to generate iPSC lines from patients with X-linked cardiomyopathy has facilitated in vitro modelling and drug testing for the condition. Nonetheless, due to the mosaicism of the X-chromosome inactivation, disease phenotypes of X-linked cardiomyopathy in heterozygous females are also usually more heterogeneous, with a broad
spectrum of presentation. Recent advancements in iPSC procedures have enabled the isolation of cells with different lyonisation to generate isogenic disease and control cell lines. In this review, we will summarise the current strategies and examples of using an iPSC-based model to study different types of X-linked cardiomyopathy. The potential application of isogenic iPSC lines derived from a female patient with heterozygous Danon disease and drug screening will be demonstrated by our preliminary data. The limitations of an iPSC-derived cardiomyocyte-based platform will also be addressed.
... Presence, distribution, and size Cadete et al., 2016 Sarcomeres/myofibrillar structure Structural integrity and sarcomere length Searls et al., 2004;Gupta et al., 2010;Saito et al., 2015;Treskatsch et al., 2015;Eisenberg et al., 2016;Takemura et al., 2017;Sibouakaz et al., 2018;Yin et al., 2018;Yuan and Pan, 2018;Babaei et al., 2020 SR Structural integrity and proximity to mitochondria Eisenberg et al., 2016;Beikoghli Kalkhoran et al., 2017 Myelin bodies/endosomal bodies/apoptotic bodies Presence Gupta et al., 2010;Chaanine, 2019;Gil-Cayuela et al., 2019 Nuclei/nuclear envelope Structure, size, and chromatin condensation Searls et al., 2004;Gupta et al., 2010;Treskatsch et al., 2015;Chaanine, 2019 Autophagosomes/autophagic vacuoles/mitophagosomes Number, size, and distribution Wohlgemuth et al., 2007;Carreira et al., 2010;Ong et al., 2010;Kanamori et al., 2011aKanamori et al., ,b, 2013Pan et al., 2012;Zhao et al., 2012;Kubli et al., 2013;Backues et al., 2014;Dupont et al., 2014;Kageyama et al., 2014;Shpilka and Elazar, 2015;Shirakabe et al., 2016;Wu et al., 2016;Takemura et al., 2017;Kang et al., 2018;Li et al., 2018;Yin et al., 2018;Chaanine, Lipid droplets Number, size, proximity to autophagosomes and mitochondria Searls et al., 2004;Caspi et al., 2013;Sibouakaz et al., 2018;Hsieh et al., 2019;Tong et al., 2019 Glycogen granules Presence, distribution, size, and aggregation Haemmerle et al., 2011;Saito et al., 2015;Takemura et al., 2017 Gap junctions/desmosomes Presence and structural integrity Hesketh et al., 2010;Caspi et al., 2013;Bonda et al., 2016;Sibouakaz et al., 2018 Telocytes Presence and distribution Popescu et al., 2010;Fertig et al., 2014;Tay et al., 2017 patients with HFrEF than those with HFpEF and was associated with significant myofibrillar loss (van Heerebeek et al., 2006). End-stage dilated cardiomyopathic heart tissue obtained from patients undergoing heart transplant showed similar changes in myofilament and sarcomeric structures, which have been linked to changes in cytoskeletal proteins including desmin (Schaper et al., 1991;Mudhar et al., 2001). Since mitochondrial dysfunction is a common feature of adverse remodeling and HF, it is not surprising that mitochondrial derangements are among the most common ultrastructural finding in TEM studies. ...
Transmission electron microscopy (TEM) has long been an important technique, capable of high degree resolution and visualization of subcellular structures and organization. Over the last 20 years, TEM has gained popularity in the cardiovascular field to visualize changes at the nanometer scale in cardiac ultrastructure during cardiovascular development, aging, and a broad range of pathologies. Recently, the cardiovascular TEM enabled the studying of several signaling processes impacting mitochondrial function, such as mitochondrial fission/fusion, autophagy, mitophagy, lysosomal degradation, and lipophagy. The goals of this review are to provide an overview of the current usage of TEM to study cardiac ultrastructural changes; to understand how TEM aided the visualization of mitochondria, autophagy, and mitophagy under normal and cardiovascular disease conditions; and to discuss the overall advantages and disadvantages of TEM and potential future capabilities and advancements in the field.
... In the next two sections, we will focus on the potential of imaging this tissue with fluorescence methods using focused examples from the literature. We will not cover electron microscopy (EM) that provides the highest resolution (~1 nm) as it has been used clinically and for pathological research for decades (Schaper 1983;Mudhar 2001;Kanzaki 2010;Saito 2015). Moreover, the down side of EM is that is that it has low contrast and is difficult to label with molecularly specific probes and is usually restricted to small regions and thin volumes in comparison with fluorescence methods that provide good contextual overview (Pullman 2019). ...
Myocardial fibrosis is recognized as a key pathological process in the development of cardiac disease and a target for future therapeutics. Despite this recognition, the assessment of fibrosis is not a part of routine clinical practice. This is primarily due to the difficulties in obtaining an accurate assessment of fibrosis non-invasively. Moreover, there is a clear discrepancy between the understandings of myocardial fibrosis clinically where fibrosis is predominately studied with comparatively low-resolution medical imaging technologies like MRI compared with the basic science laboratories where fibrosis can be visualized invasively with high resolution using molecularly specific fluorescence microscopes at the microscopic and nanoscopic scales. In this article, we will first review current medical imaging technologies for assessing fibrosis including echo and MRI. We will then highlight the need for greater microscopic and nanoscopic analysis of human tissue and how this can be addressed through greater utilization of human tissue available through endomyocardial biopsies and cardiac surgeries. We will then describe the relatively new field of molecular imaging that promises to translate research findings to the clinical practice by non-invasively monitoring the molecular signature of fibrosis in patients.
... Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques are widely used in crystallography, geology, biology, medicine, nonbiological sciences, and other fields [5] . In recent years, EDX/SEM systems have become more and more attractive for the nanoscale investigation of biological structures in various medical fields (pathology of the heart [6,7] , kidney [8,9] , skin [10,11] , and hair [12][13][14] ). ...
Background:
Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques have been used in various fields of medical research, including different pathologies of the nails; however, no studies have focused on obtaining high-resolution microscopic images and elemental analysis of disorders caused by synthetic nails and acrylic adhesives.
Methods:
Damaged/injured fingernails caused by the use of acrylate glue and synthetic nails were investigated using SEM and EDX methods.
Results:
SEM and EDX proved that synthetic nails, acrylic glue, and nails damaged by contact with acrylate glue have a different morphology and different composition compared to healthy human nails.
Conclusions:
SEM and EDX analysis can give useful information about the aspects of topography (surface sample), morphology (shape and size), hardness or reflectivity, and the elemental composition of nails.
... Signs of mitochondrial disease include ragged red fibres, cytochrome oxidase-negative fibres, succinate dehydrogenase-hyperreactive fibres, interstitial fibrosis, increased numbers of mitochondria in the subsarcolemmal and intermyofibrillar spaces, large or abnormally shaped mitochondria, and abnormal architecture of cristae such as irregular, deficient, stacking, or whorling cristae and/or the presence of paracrystalline inclusions. 23,165 Cardiac muscle biopsy is more invasive and can be performed in a patient with rapid disease progression or when biochemical testing in fibroblasts and skeletal muscle and molecular testing have not led to a conclusive diagnosis. ...
Mitochondrial cardiomyopathies are clinically and genetically heterogeneous. An integrative approach encompassing clinical, biochemical, and molecular investigations is required to reach a specific diagnosis. In this review we summarize the clinical and genetic aspects of mitochondrial disorders associated with cardiomyopathy, including disorders of oxidative phosphorylation. It also describes groups of disorders that, although not usually classified as mitochondrial disorders, stem from defects in mitochondrial function (eg, disorders of β-oxidation and the carnitine cycle), are associated with secondary mitochondrial impairment (eg, organic acidurias), and are important diagnostically because they are treatable. Current biochemical and molecular techniques for the diagnosis of mitochondrial cardiomyopathies are described, and a diagnostic algorithm is proposed, to help clinicians in their approach to cardiomyopathies in the context of mitochondrial diseases.
... Indeed, we previously presented electron microscope images, strongly suggesting that ICLC could be identified in human atrial myocardium [24]. This might be surprising for many electron microscopists, because the trivial belief is not very far from the following: '...despite electron microscopy having been used for a considerable time relatively few cases appeared to benefit directly from this investigation' [25]. ...
We have previously reported (Hinescu & Popescu, 2005) the existence of interstitial Cajal-like cells (ICLC), by transmission electron microscopy, in human atrial myocardium. In the present study, ICLC were identified with non-conventional light microscopy (NCLM) on semi-thin sections stained with toluidine blue and immunohistochemistry (IHC) for CD117/c-kit, CD34, vimentin and other additional antigens for differential diagnosis. Quantitatively, on semi-thin sections, ICLC represent about 1–1.5% of the atrial myocardial volume (vs.±45% working myocytes, ˜2% endothelial cells, 3–4% for other interstitial cells, and the remaining percentage: extracellular matrix). Roughly, there is one ICLC for 8–10 working atrial myocytes in the intercellular space, beneath the epicardium, with a characteristic (pyriform, spindle or triangular) shape. These ICLC usually have 2–3 definitory processes, emerging from cell body, which usually embrace atrial myocytes (260 nm average distance plasmalemma/sarcolemma) or establish close contact with nerve fibers or capillaries (˜420 nm average distance to endothelial cells). Cell prolongations are characteristic: very thin (mean thickness = 0.150±0.1 μm), very long for a non-nervous cell (several tens of μm) and moniliform (uneven caliber). Stromal synapses between ICLC and other interstitial cells (macrophages) were found (e.g. in a multicontact type synapse, the average synaptic cleft was ˜65 nm). Naturally, the usual cell organelles (mitochondria, smooth and rough endoplasmic reticulum, intermediate filaments) are relatively well developed. Caveolae were also visible on cell prolongations. No thick filaments were detected. IHC showed that ICLC were slightly and inconsistently positive for CD117/c-kit, variously co-expressed CD34 and EGF receptor, but appeared strongly positive for vimentin, along their prolongations. Some ICLC seemed positive for α-smooth muscle actin and tau protein, but were negative for nestin, desmin, CD13 and S-100.
