Neurofilament proteins are co-expressed with desmin in heart conduction system myocytes

1990 ◽  
Vol 97 (1) ◽  
pp. 11-21
Author(s):  
M. Vitadello ◽  
M. Matteoli ◽  
L. Gorza

We have recently shown that specialized myocytes of the rabbit heart express a cytoskeletal protein similar to the M subunit of neurofilaments (NF). Since this result was obtained using a single anti-NF-M monoclonal antibody, we tested on conduction myocytes a panel of five anti-NF antibodies, specific for each of the three NF subunits and for phosphorylated and non-phosphorylated epitopes. Two antibodies, one specific for the L subunit and one for phosphorylated M subunit of NF, reacted with specialized myocytes in immunohistochemistry. In immunoblots on conduction tissue homogenates the two antibodies recognized two polypeptides with electrophoretic mobility and solubility properties identical to those of NF-L and NF-M in the sciatic nerve. The subcellular distribution of NF immunoreactivity in specialized myocytes was very similar to desmin localization; namely, it was distributed on large filamentous bundles and on fine filaments localized transversely at the level of the Z line. At the ultrastructural level, immunoreactive filaments were localized in the intermyofibrillar space and connected myofibrils with mitochondria. Co-expression of NF proteins and desmin was also observed in vitro in a minor population of cardiac myocytes cultured from embryonic rabbit heart. In most cases NF immunoreactivity co-localized with desmin, especially where filaments were well organized, but in some cells anti-NF and anti-desmin antibodies labelled different filamentous structures. These results indicate that NF proteins are structural components of the cytoskeleton of specialized myocytes and show a subcellular distribution very similar to desmin. Such a composition of intermediate filaments indicates that in these cardiac cells muscle differentiation is compatible with the expression of neuronal proteins.

Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.


Author(s):  
A. J. Tousimis

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.


2014 ◽  
Vol 62 (S 01) ◽  
Author(s):  
A. Hoyer ◽  
P. Pritzwald-Stegmann ◽  
J. Kempfert ◽  
C. Etz ◽  
F.W. Mohr ◽  
...  
Keyword(s):  

2020 ◽  
Author(s):  
MAK Williams ◽  
V Cornuault ◽  
AH Irani ◽  
VV Symonds ◽  
J Malmström ◽  
...  

© 2020 American Chemical Society. Evidence is presented that the polysaccharide rhamnogalacturonan I (RGI) can be biosynthesized in remarkably organized branched configurations and surprisingly long versions and can self-assemble into a plethora of structures. AFM imaging has been applied to study the outer mucilage obtained from wild-type (WT) and mutant (bxl1-3 and cesa5-1) Arabidopsis thaliana seeds. For WT mucilage, ordered, multichain structures of the polysaccharide RGI were observed, with a helical twist visible in favorable circumstances. Molecular dynamics (MD) simulations demonstrated the stability of several possible multichain complexes and the possibility of twisted fibril formation. For bxl1-3 seeds, the imaged polymers clearly showed the presence of side chains. These were surprisingly regular and well organized with an average length of ∼100 nm and a spacing of ∼50 nm. The heights of the side chains imaged were suggestive of single polysaccharide chains, while the backbone was on average 4 times this height and showed regular height variations along its length consistent with models of multichain fibrils examined in MD. Finally, in mucilage extracts from cesa5-1 seeds, a minor population of chains in excess of 30 μm long was observed.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 386
Author(s):  
Ana Santos ◽  
Yongjun Jang ◽  
Inwoo Son ◽  
Jongseong Kim ◽  
Yongdoo Park

Cardiac tissue engineering aims to generate in vivo-like functional tissue for the study of cardiac development, homeostasis, and regeneration. Since the heart is composed of various types of cells and extracellular matrix with a specific microenvironment, the fabrication of cardiac tissue in vitro requires integrating technologies of cardiac cells, biomaterials, fabrication, and computational modeling to model the complexity of heart tissue. Here, we review the recent progress of engineering techniques from simple to complex for fabricating matured cardiac tissue in vitro. Advancements in cardiomyocytes, extracellular matrix, geometry, and computational modeling will be discussed based on a technology perspective and their use for preparation of functional cardiac tissue. Since the heart is a very complex system at multiscale levels, an understanding of each technique and their interactions would be highly beneficial to the development of a fully functional heart in cardiac tissue engineering.


Separations ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 57
Author(s):  
Rokayya Sami ◽  
Abeer Elhakem ◽  
Mona Alharbi ◽  
Manal Almatrafi ◽  
Nada Benajiba ◽  
...  

Onions contain high antioxidants compounds that fight inflammation against many diseases. The purpose was to investigate some selected bioactive activities of onion varieties (Yellow, Red, Green, Leek, and Baby). Antioxidant assays and anti-inflammatory activities such as NO production with the addition of some bioactive components were determined and analyzed by using a spectrophotometer. Gas chromatography and mass spectrometry (GC–MS) was used for the volatile compounds, while an Atomic absorption spectrometer was used for mineral determinations. Red variety achieved the highest antioxidant activities. The total flavonoids were between (12.56 and 353.53 mg Quercetin/gin dry weight) (dw) and the total phenol was (8.75–25.73 mg/g dw). Leek, Yellow and Green extracts achieved highly anti-inflammatory values (3.71–4.01 μg/mL) followed by Red and Baby extracts, respectively. The highest contents of sodium, potassium, zinc, and calcium were established for Red onions. Furfuraldehyde, 5-Methyl-2-furfuraldehyde, 2-Methyl-2-pentenal, and 1-Propanethiol were the most predominant, followed by a minor abundance of the other compounds such as Dimethyl sulfide, Methyl allyl disulfide, Methyl-trans-propenyl-disulfide, and Methyl propyl disulfide. The results recommend that these varieties could act as sources of essential antioxidants and anti-inflammatories to decrease inflammation and oxidative stresses, especially red onions that recorded high activities.


2021 ◽  
Vol 22 (4) ◽  
pp. 1824
Author(s):  
Matthias Mietsch ◽  
Rabea Hinkel

With cardiovascular diseases affecting millions of patients, new treatment strategies are urgently needed. The use of stem cell based approaches has been investigated during the last decades and promising effects have been achieved. However, the beneficial effect of stem cells has been found to being partly due to paracrine functions by alterations of their microenvironment and so an interesting field of research, the “stem- less” approaches has emerged over the last years using or altering the microenvironment, for example, via deletion of senescent cells, application of micro RNAs or by modifying the cellular energy metabolism via targeting mitochondria. Using autologous muscle-derived mitochondria for transplantations into the affected tissues has resulted in promising reports of improvements of cardiac functions in vitro and in vivo. However, since the targeted treatment group represents mainly elderly or otherwise sick patients, it is unclear whether and to what extent autologous mitochondria would exert their beneficial effects in these cases. Stem cells might represent better sources for mitochondria and could enhance the effect of mitochondrial transplantations. Therefore in this review we aim to provide an overview on aging effects of stem cells and mitochondria which might be important for mitochondrial transplantation and to give an overview on the current state in this field together with considerations worthwhile for further investigations.


2021 ◽  
pp. 104063872199668
Author(s):  
Waléria Borges-Silva ◽  
Mariana M. Rezende-Gondim ◽  
Gideão S. Galvão ◽  
Daniele S. Rocha ◽  
George R. Albuquerque ◽  
...  

Parasites resembling Neospora caninum or Toxoplasma gondii were detected by cytologic examination of cerebrospinal fluid (CSF) from a dog with neurologic disease. The dog became severely ill and was euthanized. Canine tissue homogenates were used for direct parasite isolation in cell culture, bioassay in 2 mouse lineages, and PCR. T. gondii was isolated in monkey kidney cells, and species identity was confirmed by PCR. Inoculated parasites were highly virulent for mice, which developed clinical signs and were euthanized immediately. PCR-RFLP for T. gondii using the cultured isolate (TgDgBA22) was conducted with 12 genetic markers, and a unique recombinant strain was identified. Detection of T. gondii by CSF cytology, although described in humans, had not been reported previously in dogs, to our knowledge, and was crucial for the diagnosis of toxoplasmosis in the examined dog.


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