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1.
Recently, the presence of telocytes was demonstrated in human and mammalian tissues and organs (digestive and extra-digestive organs, genitourinary organs, heart, placenta, lungs, pleura, striated muscle). Noteworthy, telocytes seem to play a significant role in the normal function and regeneration of myocardium. By cultures of telocytes in two- and three-dimensional environment we aimed to study the typical morphological features as well as functionality of telocytes, which will provide important support to understand their in vivo roles. Neonatal rat cardiomyocytes were isolated and cultured as seeding cells in vitro in two-dimensional environment. Furthermore, engineered myocardium tissue was constructed from isolated cells in three-dimensional collagen/Matrigel scaffolds. The identification of telocytes was performed by using histological and immunohistochemical methods. The results showed that typical telocytes are distributed among cardiomyocytes, connecting them by long telopodes. Telocytes have a typical fusiform cell body with two or three long moniliform telopodes, as main characteristics. The vital methylene blue staining showed the existence of telocytes in primary culture. Immunohistochemistry demonstrated that some c-kit or CD34 immuno-positive cells in engineered heart tissue had the morphology of telocytes, with a typical fusiform cell body and long moniliform telopodes. Also, a significant number of vimentin+ telocytes were present within engineered heart tissue. We suggest that the model of three-dimensional engineered heart tissue could be useful for the ongoing research on the functional relationships of telocytes with cardiomyocytes. Because the heart has the necessary potential of changing the muscle and non-muscle cells during the lifetime, telocytes might play an active role in the heart regeneration process. Moreover, telocytes might be a useful tool for cardiac tissue engineering.  相似文献   

2.
Telocytes, newly discovered in the last decade, are interstitial cells found in numerous organs, with multiple proposed potential biological functions. Toll‐like receptors (TLRs) play an important role in innate and adaptive immunity by recognizing pathogen‐associated molecular patterns (PAMPs). However, it is still unknown whether telocytes express these innate receptors. We sought to determine the expression and role of TLRs in telocytes. In our study, we primarily detected TLR1‐9 expression in telocytes. The proliferation, apoptosis and immunoregulatory activity of telocytes activated with or without TLR ligands were determined. Our results showed that purified telocytes expressed TLR2, TLR3 and TLR5. In particular, telocytes expressed high levels of TLR2 as observed using flow cytometry. When we stimulated telocytes with TLR2 or TLR3 agonists (Pam3CSK4, PolyI:C), iNOS expression was greatly increased after Pam3CSK4 treatment. Additionally, telocyte proliferation was reduced and cell apoptosis was increased after TLR agonist stimulation. A co‐culture experiment showed that supernatant from telocytes pretreated with Pam3CSK4 inhibited T cell activation much more than that from untreated telocytes and this effect was mediated by iNOS. Overall, our results demonstrated TLR expression on telocytes for the first time and provided evidence of an immunoregulatory role of telocytes, indicating their clinical potential.  相似文献   

3.
Telocytes, a novel type of interstitial cells with very long and thin prolongations, have been identified in many organs in mammals. At present, the ultrastructural, immunocytochemical and electrophysiological properties of telocytes in multiple organs have been understood. However, telocytes in spleen, especially their roles in spleen have not been reported. The aim of this study was to investigate the ultrastructure, distribution and immunophenotypes of splenic telocytes. Rat spleen was harvested for the ultrastructure analysis by transmission electron microscopy (TEM). The primary culture of telocytes was performed after combined enzymatic digestion. The characteristic morphology was analyzed by a scanning electron microscopy (SEM). It was shown that telocytes displayed a piriform/spindle/triangular shape with long and slender telopods and extremely long prolongation contracting with surrounding cells in the spleen. Their dynamic profiles of cytoplasmic separation were recorded by the Live Cell Imaging System. The length of telopods was mostly distributing in 20–30 μm, in accordance with normal distribution. Most telocytes had three or two telopods (28.71% and 22.58% respectively). Immunostaining indicated that these cells were positive for vimentin, CD34, nanog and sca-1, but negative for c-kit. These data prove the existence of telocytes in the spleen, which may serve as the experimental base for exploring their roles in the spleen.  相似文献   

4.
Interstitial Cajal-like cells are a distinct type of interstitial cell with a wide distribution in mammalian organs and tissues,and have been given the name"telocytes".Recent studies have demonstrated the potential roles of telocytes in heart development,renewal,and repair.However,further research on the functions of telocytes is limited by the complicated in vivo environment.This study was designed to construct engineered heart tissue(EHT)as a three-dimensional model in vitro to better understand the role of telocytes in the architectural organization of the myocardium.EHTs were constructed by seeding neonatal cardiomyocytes in collagen/Matrigel scaffolds followed by culture under persistent static stretch.Telocytes in EHTs were identified by histology,toluidine blue staining,immunofluorescence,and transmission electron microscopy.The results from histology and toluidine blue staining demonstrated widespread putative telocytes with compact toluidine blue-stained nuclei,which were located around cardiomyocytes.Prolongations from the cell bodies showed a characteristic dichotomous branching pattern and formed networks in EHTs.Immunofluorescence revealed positive staining of telocytes for CD34 and vimentin with typical moniliform prolongations.A series of electron microscopy images further showed that typical telocytes embraced the cardiomyocytes with their long prolongations and exhibited a marked appearance of nursing cardiomyocytes during the construction of EHTs.This finding highlights the great importance of telocytes in the architectural organization of EHTs.It also suggests that EHT is an appropriate physical and pathological model system in vitro to study the roles of telocytes during heart development and regeneration.  相似文献   

5.
The existence of the epicardial telocytes was previously documented by immunohistochemistry (IHC) or immunofluorescence. We have also demonstrated recently that telocytes are present in mice epicardium, within the cardiac stem‐cell niches, and, possibly, they are acting as nurse cells for the cardiomyocyte progenitors. The rationale of this study was to show that telocytes do exist in human (sub)epicardium, too. Human autopsy hearts from 10 adults and 15 foetuses were used for conventional IHC for c‐kit/CD117, CD34, vimentin, S‐100, τ, Neurokinin 1, as well as using laser confocal microscopy. Tissue samples obtained by surgical biopsies from 10 adults were studied by digital transmission electron microscopy (TEM). Double immunolabelling for c‐kit/CD34 and, for c‐kit/vimentin suggests that in human beings, epicardial telocytes share similar immunophenotype features with myocardial telocytes. The presence of the telocytes in human epicardium is shown by TEM. Epicardial telocytes, like any of the telocytes are defined by telopodes, their cell prolongations, which are very long (several tens of μm), very thin (0.1–0.2 μm, below the resolving power of light microscopy) and with moniliform configuration. The interconnected epicardial telocytes create a 3D cellular network, connected with the 3D network of myocardial telocytes. TEM documented that telocytes release shed microvesicles or exocytotic multivesicular bodies in the intercellular space. The human epicardial telocytes have similar phenotype (TEM and IHC) with telocytes located among human working cardiomyocyte. It remains to be established the role(s) of telocytes in cardiac renewing/repair/regeneration processes, and also the pathological aspects induced by their ‘functional inhibition’, or by their variation in number. We consider telocytes as a real candidate for future developments of autologous cell‐based therapy in heart diseases.  相似文献   

6.
Systemic sclerosis (SSc) is a complex connective tissue disease characterized by fibrosis of the skin and various internal organs. In SSc, telocytes, a peculiar type of stromal (interstitial) cells, display severe ultrastructural damages and are progressively lost from the clinically affected skin. The aim of the present work was to investigate the presence and distribution of telocytes in the internal organs of SSc patients. Archival paraffin‐embedded samples of gastric wall, myocardium and lung from SSc patients and controls were collected. Tissue sections were stained with Masson's trichrome to detect fibrosis. Telocytes were studied on tissue sections subjected to CD34 immunostaining. CD34/CD31 double immunofluorescence was performed to unequivocally differentiate telocytes (CD34‐positive/CD31‐negative) from vascular endothelial cells (CD34‐positive/CD31‐positive). Few telocytes entrapped in the fibrotic extracellular matrix were found in the muscularis mucosae and submucosa of SSc gastric wall. In the muscle layers and myenteric plexus, the network of telocytes was discontinuous or even completely absent around smooth muscle cells and ganglia. Telocytes were almost completely absent in fibrotic areas of SSc myocardium. In SSc fibrotic lung, few or no telocytes were observed in the thickened alveolar septa, around blood vessels and in the interstitial space surrounding terminal and respiratory bronchioles. In SSc, the loss of telocytes is not restricted to the skin, but it is a widespread process affecting multiple organs targeted by the fibrotic process. As telocytes are believed to be key players in the regulation of tissue/organ homoeostasis, our data suggest that telocyte loss might have important pathophysiological implications in SSc.  相似文献   

7.
Recently the new term 'telocytes' has been proposed for cells formerly known as interstitial Cajal-like cells. In fact, telocytes are not really Cajal-like cells, they being different from all other interstitial cells by the presence of telopodes, which are cell-body prolongations, very thin, extremely long with a moniliform aspect. The identification of these cells is based on ultrastructural criteria. The presence of telocytes in others organs was previously documented. We reported for the first time, an ultrastructural study of telocytes in the lamina propria of rat duodenum. Our findings show that typical telocytes are present in the rat duodenum. Telocytes are located in the lamina propria, immediately below mucosal crypts. Telopodes frequently establish close spatial relationships with immune cells, blood vessels and nerve endings. On the basis of their distribution and morphology, we suggest that these cells may be involved in immune response and in our opinion, it may be possible that different locations of telocytes could be associated with different roles.  相似文献   

8.
AIMS: Fascia lata is used in different shapes and sizes as a graft material in surgical procedures. The conventional method of harvesting a fascia lata graft is through a long skin incision on the lateral aspect of the thigh. Minimal invasive procedures have been established to reduce the disadvantages of an extensive surgical approach for obtaining the autotransplant. However, they do not facilitate to suture the remaining fascia after harvesting the transplant and therefore bear the risk of a symptomatic herniation of the muscle belly. The aim of this study was to design a surgical device to harvest a fascia lata graft and close the resulting fascia defect as a minimal invasive procedure. MATERIALS AND METHODS: The prototype was tested in 11 human cadaver specimens. It was introduced subcutanously via two small skin incisions. The device contained a special fixation- and working mechanism which enabled the fascial closure using a continuous suture. After the harvest procedure, both the transplant and the sutured fascia lata were examined. RESULTS: The experiments demonstrated the suitability of this method for minimal invasive harvesting of fascia lata. The removed transplants complied in all experiments with the expected dimensions. The continuous suture of the femoral fascia ran with accurate gaps between the sutures and constant tension without dehiscence. Neither the transplant nor the tissue in the region of harvest have shown unduly macroscopic damage due to the use of the device. CONCLUSION: The designed prototype can be used for harvesting a fascia lata graft and repairing the resulting defect minimal invasively. Clinical implementation seems possible. However, improvements could be made mainly concerning the handling of the device.  相似文献   

9.
Previous studies have shown that telocytes are found in a variety of tissues. Here, we report the presence of telocytes in the human endometrium. In addition, telocytes were isolated from the rat endometrium and cultured. Immunohistochemistry was performed in vitro and in vivo. Cultured cells showed that telocytes expressed CD34, and similar results were found in the uterine tissue. In both species, telocytes also stained positive for vimentin and connexin 43. Telopodes were observed connecting cell colonies and connecting distant cells. Our findings suggest that telocytes may have a role in cell-to-cell communication over short and long distances within the endometrium.  相似文献   

10.
Over an eight-month period beginning in November 1969, 53 patients received 63 fascia lata heart valves at the Toronto General Hospital. The late results of this form of valve substitution are reviewed. The fascia used to fashion the tricuspid valve underwent progressive thickening and contracture and this process caused failure of the prosthesis within months of insertion. The mitral fascial prosthesis failed in a similar manner although the process took longer. The aortic fascia lata valve, however, has not shown progressive thickening after 3½ years and it has so far retained its functional integrity. Indeed, we have been impressed by the excellent clinical results and absence of complications such as thromboembolism although anticoagulation has not been used. We therefore consider that fascia lata valves offer a suitable alternative to other forms of aortic valve substitution, but are unsatisfactory for tricuspid or mitral valve replacement.  相似文献   

11.
Telocytes, a peculiar type of stromal cells, have been recently identified in a variety of tissues and organs, including human skin. Systemic sclerosis (SSc, scleroderma) is a complex connective tissue disease characterized by fibrosis of the skin and internal organs. We presently investigated telocyte distribution and features in the skin of SSc patients compared with normal skin. By an integrated immunohistochemical and transmission electron microscopy approach, we confirmed that telocytes were present in human dermis, where they were mainly recognizable by their typical ultrastructural features and were immunophenotypically characterized by CD34 expression. Our findings also showed that dermal telocytes were immunophenotypically negative for CD31/PECAM‐1 (endothelial cells), α‐SMA (myofibroblasts, pericytes, vascular smooth muscle cells), CD11c (dendritic cells, macrophages), CD90/Thy‐1 (fibroblasts) and c‐kit/CD117 (mast cells). In normal skin, telocytes were organized to form three‐dimensional networks distributed among collagen bundles and elastic fibres, and surrounded microvessels, nerves and skin adnexa (hair follicles, sebaceous and sweat glands). Telocytes displayed severe ultrastructural damages (swollen mitochondria, cytoplasmic vacuolization, lipofuscinic bodies) suggestive of ischaemia‐induced cell degeneration and were progressively lost from the clinically affected skin of SSc patients. Telocyte damage and loss evolved differently according to SSc subsets and stages, being more rapid and severe in diffuse SSc. Briefly, in human skin telocytes are a distinct stromal cell population. In SSc skin, the progressive loss of telocytes might (i) contribute to the altered three‐dimensional organization of the extracellular matrix, (ii) reduce the control of fibroblast, myofibroblast and mast cell activity, and (iii) impair skin regeneration and/or repair.  相似文献   

12.
We advance the hypothesis that the telocyte might be the cell of origin of both PEComas (perivascular epithelioid cell tumours) and GISTs (gastro-intestinal and extra-gastrointestinal stromal tumours). The hypothesis is supported by data from the literature reporting that both PEComas and GISTs, as well as telocytes, share the expression of several markers. These data were supplemented by original immunohistochemical tests on selected series. Specifically: (1) Melanoma markers (Melan A, MiTF) typical of PEComas are expressed by a substantial fraction of GISTs. A fraction of GISTs was also found positive for CD63, a tetraspanin protein originally described in melanomas and marking exosomes. (2) c-KIT (CD117), proper of the vast majority of GISTs, can be expressed by PEComas (as well as by telocytes). (3) Markers described in telocytes (CD34, S-100, smooth muscle actin and vascular endothelial growth factor) have been reported as positive in cases of PEComas and GISTs. Telocytes show distinctive ultrastructural features with thin, extended, telopodes and are likely involved in inter-cellular signalling via paracrine secretion as well as by shed vesicles and exosomes. These cells have been described in many locations (cavitary and non-cavitary organs) and might display potentialities of a wide spectrum of differentiation (and function). In conclusion we propose that telocytes could be the common cells of origin for both PEComas and GISTs.  相似文献   

13.
The purpose of this study was to evaluate the effects of treatment of curvature in Peyronie's disease with a relaxation incision and fascia lata grafting. Between 2000 and 2002, this technique was used for 12 patients with a 1-year history of plaque and curvature of more than 35 degrees. Penile degloving was performed with a circumferential incision. The tunica defect was closed with fascia lata grafting after a relaxation incision. For all patients, penile curvature was corrected and normal erections were achieved. No complication was observed in 9 to 24 months (mean, 10 months) of follow-up monitoring. The initial results suggested that tunica albuginea incision and fascia lata grafting could represent an alternative for the treatment of curvature in Peyronie's disease. Further studies are warranted.  相似文献   

14.
Experiments were performed to determine the mechanical importance of the fascia lata in stopping the hind limb during its rearward extension and reversing the direction of leg swing. Samples of fascia lata from a number of different mammals were subjected to tensile tests. Tangent Young's moduli reached about 0.5 GPa and stresses at failure about 50 MPa for fascia from each of the species examined. Energy losses incurred in a loading-unloading cycle were generally about 20%. The moment arms of the fascia lata, in combination with its muscle, about the hip and knee joints were determined and the extension of the fascia lata while its muscle is active was estimated. Calculations suggest that the fascia lata could help to reverse the backward swing of the hind limb by recoiling elastically shortly after the foot leaves the ground. Substantial savings of internal kilnetic energy could be made.  相似文献   

15.
The sinoatrial node (SAN) is composed mostly of pacemaker, transitional and Purkinje‐like cells. Pacemaker cells, especially in the centre of the SAN, are surrounded by dense fibrous tissue and do not have any contact with transitional cells. We hypothesize that the SAN contains telocytes that have contacts with pacemaker cells and contractile myocardium. Immunohistochemistry using antibodies against HCN4 and antibody combinations against CD34 and HCN4 was carried out on 12 specimens. Confocal laser scanning microscopy (CLSM) with two mixtures of primary antibodies, namely CD34/S100 and vimentin/S100, was performed in three cases. In two cases, CLSM was carried out with CD117 antibody. Specimens for electron microscopy and immunocytochemistry with HCN4 immunogold labelling were taken from another three patients. In our study, we found cells with the immunophenotype of telocytes in the SAN. There were twice as many of these cells in the centre of the SAN as in the periphery (20.3 ± 4.8 versus 10.8 ± 4.4 per high‐power field). They had close contact with pacemaker cells and contractile cardiomyocytes and expressed HCN4. The ultrastructural characteristics of these cells are identical to those of telocytes observed earlier in other organs. Our study provides evidence that telocytes are present in the SAN.  相似文献   

16.
The major mechanisms of gallstone formation include biliary cholesterol hypersecretion, supersaturation and crystallization, mucus hypersecretion, gel formation and bile stasis. Gallbladder hypomotility seems to be a key event that triggers the precipitation of cholesterol microcrystals from supersaturated lithogenic bile. Telocytes, a new type of interstitial cells, have been recently identified in many organs, including gallbladder. Considering telocyte functions, it is presumed that these cells might be involved in the signalling processes. The purpose of this study was to correlate the quantity of telocytes in the gallbladder with the lithogenicity of bile. Gallbladder specimens were collected from 24 patients who underwent elective laparoscopic cholecystectomy for symptomatic gallstone disease. The control group consisted of 25 consecutive patients who received elective treatment for pancreatic head tumours. Telocytes were visualized in paraffin sections of gallbladders with double immunofluorescence using primary antibodies against c‐Kit (anti‐CD117) and anti‐mast cell tryptase. Cholesterol, phospholipid and bile acid levels were measured in gallbladder bile. The number of telocytes in the gallbladder wall was significantly lower in the study group than that in the control group (3.03 ± 1.43 versus 6.34 ± 1.66 cell/field of view in the muscularis propria, < 0.001) and correlated with a significant increase in the cholesterol saturation index. The glycocholic and taurocholic acid levels were significantly elevated in the control subjects compared with the study group. The results suggest that bile composition may play an important role in the reduction in telocytes density in the gallbladder.  相似文献   

17.
特络细胞是一种新型间质细胞,其最显著的形态特征是具有极其细长且粗细不均而呈念珠形的细胞突起,可以和周围的同/异型细胞、血管、神经末梢等形成细胞连接.特络细胞还可释放细胞外囊泡(EVs)和其他信号分子,从而发挥其潜在的生理功能.先前的研究表明,特络细胞的功能与动物组织再生有关,因此对于低等动物特络细胞的研究有助于进一步理...  相似文献   

18.
A little is known about proteoglycan (PG) changes, occuring in the course of scarring of tissues another than skin. The aim of present study was biochemical characterization of glycosaminoglycans (GAGs) and proteoglycans (PGs) of normal and scarred fascia. Samples of normal fascia lata were taken at autopsy from 23 individuals and samples of scarred fascia lata were removed from 23 patients at reoperations for femoral fracture. The obtained tissues were divided into two samples: first of them was submitted to GAG isolation and the second one to PG isolation.GAGs were extracted by extensive papain digestion followed by the fractionation using cetylpyridinium chloride. In order to qualitative and quantitative characterization GAGs were submitted to electrophoresis on cellulose acetate before and after treatment with enzymes, specifically depolymerizing some kinds of GAGs. PGs were extracted using 4 M guanidine HCl followed by purification by forming complexes with Alcian blue. PGs were submitted to gel permeation chromatography on Sepharose 4B. In order to obtain core proteins PGs were depolymerized with chondroitinase ABC. The purified PGs and their core proteins were separated with sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS/PAGE). It was found that total GAGs content was significantly elevated in scarred fascia. Both types of fascia contained chondroitin-, dermatan- and heparan sulphates and hyaluronic acid. Dermatan sulphates (DS) were the predominant GAGs of normal and scarred fascia. The contents of all GAG types were increased in scarred fascia. Both types of fascia contained two kinds of dermatan sulphate proteoglycans (DSPGs); first being similar to biglycan and the second one similar to decorin, as it was judged by molecular weight of their native molecules and core proteins as well as type of GAG components. Densitometric analysis showed that decorin is a predominant DSPG in both fascia types, but in scarred tissue the ratio of biglycan to decorin is considerably higher. Moreover, in scarred fascia a large chondroitin sulphate proteoglycan (CSPG) was also observed. The obtained results have shown that the scar formation is accompanied by quantitative and qualitative alterations in GAGs/PGs resembling those observed in hypertrophic skin scars. The biochemical modification of the scarred fascia lata may partly explain the clinically manifested damage to biomechanical properties of this tissue.  相似文献   

19.
Telocytes had been identified as a peculiar stromal cell type implicated in tissue homeostasis and the development and pathophysiology of diseases. Telocyte existed in most organs and tissues in humans and animals. However, few studies have examined telocytes in ApoE gene deficient mice. In our studies, we verified the existence, the morphology and immunohistochemical characteristics of telocytes in critical organs of the ApoE?/? mice. Male adult ApoE?/? mice were selected as an experimental model. Immunohistochemical bio‐markers, such as CD34, CD117, CD28, Vimentin and PDGFR‐α were utilized to determine the distribution and morphology of telocytes in the heart, liver and kidney. Telocyte expressed positively for CD34 and CD117, and partial telocyte and telopode expressed positively for PDGFR‐α in heart and liver, but negatively in kidney. Double immunofluorescence assays for CD28/Vimentin, CD34/CD117 and CD34/PDGFR‐α were used to demonstrate the biochemistry speciality of telocytes, respectively. The evidence of telocytes in the ApoE‐/‐ mice is the first step of our sturdy, which aims to demonstrate changes in telocytes in atherosclerosis in this animal model.  相似文献   

20.
The whole thigh muscles are covered with the fascia lata, which could have morphological and mechanical features that match the underlying muscles’ functions. In this study, we investigated the morphological and elastic properties of the human fascia lata taken from four (anterior, medial, lateral, and posterior) sites on the thigh of 17 legs of 12 cadavers (6 males and 6 females, 75–92 years). The thickness of the fascia lata was determined with a caliper. The interwoven collagen fiber’s directions were measured and classified into longitudinal, transverse, and diagonal in two opposing directions, relative to the thigh. Tensile strength test along the longitudinal and transverse directions was performed, and the stiffness, Young’s modulus, and hysteresis were determined. Fascia lata at the lateral site (0.8 ± 0.2 mm) was significantly thicker compared to other sites (0.2–0.3 mm). Fiber’s directions showed substantial variability among sites, and longitudinally directed fibers were higher in proportion (28–32%) than those in other directions (20–27%) at all sites except for the posterior site. The stiffness and Young’s modulus in the longitudinal direction (20–283 N/mm; 71.6–275.9 MPa, highest at the lateral site) were significantly higher than in the transverse direction (3–16 N/mm; 3.2–41.9 MPa, lowest at the lateral site). At the medial site, the proportion of the transversely directed fibers was higher in females than males, with higher stiffness and Young’s modulus thereof. The present study shows that the fascia lata possesses site- and gender-dependence of the morphological characteristics and elastic properties.  相似文献   

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