BACKGROUNDThis study characterized the cardiac telocyte (TC) population both in vivo and in vitro, and investigated its telomerase activity related to mitosis.

METHODSUsing transmission electron microscopy and a phase contrast microscope, the typical morphological features of cardiac TCs were observed; by targeting the cell surface proteins CD117 and CD34, CD117 + CD34 + cardiac TCs were sorted via flow cytometry and validated by immunofluorescence based on the primary cell culture. Then the optimized basal nutrient medium for selected population was examined with the cell counting kit 8. Under this conditioned medium, the process of cell division was captured, and the telomerase activity of CD117 + CD34 + cardiac TCs was detected in comparison with bone mesenchymal stem cells (BMSCs), cardiac fibroblasts (CFBs), cardiomyocytes (CMs).

RESULTSCardiac TCs projected characteristic telopodes with thin segments (podomers) in alternation with dilation (podoms). In addition, 64% of the primary cultured cardiac TCs were composed of CD117 + CD34 + cardiac TCs; which was verified by immunofluorescence. In a live cell imaging system, CD117 + CD34 + cardiac TCs were observed to enter into cell division in a short time, followed by an significant invagination forming across the middle of the cell body. Using a real-time quantitative telomeric-repeat amplification assay, the telomerase concentration in CD117 + CD34 + cardiac TCs was obviously lower than in BMSCs and CFBs, and significantly higher than in CMs.

CONCLUSIONSCardiac TCs represent a unique cell population and CD117 + CD34 + cardiac TCs have relative low telomerase activity that differs from BMSCs, CFBs and CMs and thus they might play an important role in maintaining cardiac homeostasis.

Animals ; Antigens, CD34 ; metabolism ; Fibroblasts ; enzymology ; ultrastructure ; Flow Cytometry ; Mesenchymal Stromal Cells ; enzymology ; ultrastructure ; Mice ; Mice, Inbred C57BL ; Microscopy, Confocal ; Microscopy, Electron, Transmission ; Microscopy, Phase-Contrast ; Myocytes, Cardiac ; enzymology ; ultrastructure ; Proto-Oncogene Proteins c-kit ; metabolism ; Telomerase ; metabolism ; Vimentin ; metabolism

OBJECTIVETo study the effect of Ti-TiO2 nanotubes with different diameters on the adhesion of fibroblast and osteoblast, and to find which diameter was more favorable for cells' respective adhesion.

METHODSPure titanium sheets were polished and then anodized at different potentials for 1 h with Ti as anode and Pt as cathode. TiO2 nanotubes formed at 1, 5, 10 and 20 V potentials served as experimental groups and polished pure titanium served as control group. Field emission scanning electron microscopy (Fe-SEM) was used to analyze the surface topography. Stained nucleus with Hoechst33342 were used to measure the cell adhesion. The cell shape on the sample surface were analyzed with Fe-SEM.

RESULTSTiO2 nanotube array of different inner diameters from 15 nm to 100 nm were grown on titanium sheets by anodization at potentials from 1 to 20 V. At 30, 60 and 120 min, fibroblast adhesion at nanotubes anodized at 5 V was (141 ± 9), (388 ± 14) and (489 ± 15) respectively, significantly less than any other nanotube surface at the same time (P < 0.01). Nanotubes anodized at 20 V had the least inhibitory effect for fibroblast adhesion with a number of (579 ± 14) at 120 min, and the cell shape was also inhibited. At 30, 60 and 120 min, osteoblast had a significant better adhesion on nanotubes formed at 5 V than it did on any other surface at the same time (P < 0.01), except the control group at 30 min, with the adhesion number of (198 ± 10), (431 ± 10) and (501 ± 10) respectively, and osteoblast had a abundant spread on nanotubes formed at 5 V; while osteoblast adhesion on nanotubes anodized at 20 V was (152 ± 11), (403 ± 9) and (465 ± 12) respectively, less than on any other nanotube surface within the same time (P < 0.05), and the cell shape on the surface changed to be more elongate.

CONCLUSIONSFibroblast adhesion is inhabited more or less on Ti-TiO2 nanotubes of different diameters. Nanotubes formed at 5 V have the most osteoblast adhesion, and inhibit fibroblast adhesion.

Animals ; Cell Adhesion ; Fibroblasts ; cytology ; ultrastructure ; Mice ; Microscopy, Electron, Scanning ; Nanotubes ; chemistry ; Osteoblasts ; cytology ; ultrastructure ; Surface Properties ; Titanium ; chemistry

Cholesterol is one of major components of cell membrane and plays a role in vesicular trafficking and cellular signaling. We investigated the effects of cholesterol on matrix metalloproteinase-2 (MMP-2) activation in human dermal fibroblasts. We found that tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) expression and active form MMP-2 (64 kD) were dose-dependently increased by methyl-beta-cyclodextrin (MbetaCD), a cholesterol depletion agent. In contrast, cholesterol depletion-induced TIMP-2 expression and MMP-2 activation were suppressed by cholesterol repletion. Then we investigated the regulatory mechanism of TIMP-2 expression by cholesterol depletion. We found that the phosphorylation of JNK as well as ERK was significantly increased by cholesterol depletion. Moreover, cholesterol depletion-induced TIMP-2 expression and MMP-2 activation was significantly decreased by MEK inhibitor U0126, and JNK inhibitor SP600125, respectively. While a low dose of recombinant TIMP-2 (100 ng/ml) increased the level of active MMP-2 (64 kD), the high dose of TIMP-2 (> or = 200 ng/ml) decreased the level of active MMP-2 (64 kD). Taken together, we suggest that the induction of TIMP-2 by cholesterol depletion leads to the conversion of proMMP-2 (72 kD) into active MMP-2 (64 kD) in human dermal fibroblasts.
Anthracenes/pharmacology ; Butadienes/pharmacology ; Cells, Cultured ; Child ; Child, Preschool ; Cholesterol/metabolism/*physiology ; Cyclodextrins/pharmacology ; Enzyme Inhibitors/pharmacology ; Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors/physiology ; Fibroblasts/*drug effects/*metabolism/ultrastructure ; Humans ; Immunoblotting ; Immunoprecipitation ; JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors/physiology ; Matrix Metalloproteinase 2/*metabolism ; Microscopy, Electron, Transmission ; Nitriles/pharmacology ; Tissue Inhibitor of Metalloproteinase-2/*metabolism

BACKGROUNDCellular cardiomyoplasty by transplantation of various cell types has been investigated as potential treatments for the improvement of cardiac function after myocardial injury. A major barrier for the clinical application of cell transplantation is obtaining sufficiently large quantities of suitable cells. Allogeneic cellular cardiomyoplasty may provide an alternative source of abundant, transplantable, myogenic cells by in vitro manipulation of cardiac fibroblasts using chemicals including 5-azacytidine. This study evaluated cardiomyogenic differentiation of cardiac fibroblasts, their survival in myocardial scar tissue, and the effect of the implanted cells on heart function.

METHODSPrimary cardiac fibroblasts from neonatal rats were treated with 5-azacytidine (10 µmol/L) or control. Treatment of 5-azacytidine caused myogenic differentiation of cultured cardiac fibroblasts, as defined by elongation and fusion into multinucleated myotubes with sarcomeric structures as identified by electron microscopy, and positive immunostaining for cardiac specific proteins, troponin I and β-myosin heavy chain (β-MHC) and the gap junction protein connexin 43. The myogenic cells (1.0 × 10⁶) were transplanted into the infarcted myocardium 2 weeks after coronary artery occlusion.

RESULTSBy 1 month after transplantation, the converted fibroblasts gave rise to a cluster of cardiac-like muscle cells that in the hearts occupied a large part of the scar with positive immunostaining for the myogenic proteins troponin I and β-MHC. Engrafted cells also expressed the gap junction protein connexin 43 in a disorganized manner. There was no positive staining in the control hearts treated with injections of culture medium. Heart function was evaluated at 6 weeks after myocardial injury with echocardiographic and hemodynamic measurements. Improvement in cardiac function was seen in the hearts transplanted with the 5-azacytidine-treated cardiac fibroblasts which was absent in the hearts treated with control.

CONCLUSIONThe 5-azacytidine has a unique capacity to induce myogenesis in cardiac fibroblasts in vitro and transplantation of cardiac-like muscle cells into ventricular scar tissue improves myocardial function.

Animals ; Azacitidine ; therapeutic use ; Cells, Cultured ; Fibroblasts ; drug effects ; transplantation ; ultrastructure ; Immunohistochemistry ; Microscopy, Electron, Transmission ; Myocardial Infarction ; drug therapy ; therapy ; Rats

BACKGROUNDWhether the low molecular weight heparin microcapsule coated occluder is helpful to endothelialization in atrial-septal defect models is uncertain. This study aimed to investigate the best conditions for low molecular weight heparin coated NiTi alloy occluder and provide the evidence of the efficacy and safety of atrial-septal defect occluders in vivo.

METHODSLow molecular weight heparin microcapsules were investigated using gelatin as microcapsule material. The prepared low molecular weight heparin gelatin particles were subjected to nickel and titanium alloy occluder coating by sodium hyaluronate. A dog model of atrial septal defects was established after treatment with low molecular weight heparin microcapsule coated occluder (n = 4) and uncoated occluder (n = 4). Endotheliocytes and fibroblastic cells in occluders were observed. And the rate of endothelialization was detected.

RESULTSWhen the concentration of gelatin was 1%, the diameters of particles were mostly about 100 microm, and the particle size was uniform. The envelope efficiency of low molecular weight heparin microcapsule was about 80%. The endothelialization of occluder in the model was more obvious in the coated group than in the uncoated group (P < 0.0001).

CONCLUSIONSLow molecular weight heparin can be prepared into microcapsules with their particle size in nanometric grade. The antithrombotic properties are kept in the nickel and titanium alloy occluder successfully coated with sodium hyaluronate. The endothelialization after the interventional occlusion in the coated group is obvious, indicating that low molecular weight heparin is helpful to the growth of endothelial cells in the occlude and the healing after the interventional occlusion.

Alloys ; chemistry ; Animals ; Anticoagulants ; pharmacology ; Capsules ; chemistry ; Disease Models, Animal ; Dogs ; Endothelial Cells ; drug effects ; ultrastructure ; Fibroblasts ; drug effects ; Gelatin ; chemistry ; Heart Septal Defects, Atrial ; drug therapy ; Heparin, Low-Molecular-Weight ; chemistry ; pharmacology ; Immunohistochemistry ; Microscopy, Electron, Transmission ; Particle Size ; Random Allocation

INTRODUCTIONAn investigation was carried out to determine the morphological characteristics of fibroblasts in two portions of the vocal fold (VF) mucosa, the macula flava (MF) and Reinke's space (RS), of three different age groups: newborns, adults and geriatrics.

METHODSNormal human VF obtained from autopsy cases were included in this study: four from mature newborns; four from middle-aged adults; and four from geriatric cases. Fibroblasts in RS and MF were investigated by transmission electron microscopy.

RESULTSThe fibroblasts of the MF in both adults and newborns tended to be stellate in shape, with a small nucleus/cytoplasm (N/C) ratio and a well-developed rough endoplasmic reticulum (rER) and Golgi apparatus (GA). Most of the fibroblasts present in RS were oval in newborns and spindle-shaped in adults, with a large N/C ratio and less developed rER and GA. The majority of fibroblasts of the geriatric MF were stellate in shape; while in geriatric RS, the majority of fibroblasts were spindle-shaped with an N/C ratio of 0.5 to 2.0 as in the case of adults. However, the development of rER and GA was less marked in geriatrics than in adults.

CONCLUSIONHistological changes of fibroblasts in the VF mucosa are one of the important causes of the change in voice quality with ageing. Furthermore, geriatric changes in the vocal ligament can be attributed to the activities and the presence of ageing processes in fibroblasts of geriatric VF mucosa.

Adult ; Age Factors ; Aged ; Cell Nucleus ; ultrastructure ; Cytoplasm ; ultrastructure ; Endoplasmic Reticulum ; ultrastructure ; Female ; Fibroblasts ; ultrastructure ; Golgi Apparatus ; ultrastructure ; Humans ; Infant, Newborn ; Laryngeal Mucosa ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; methods ; Vocal Cords ; ultrastructure

This study was undertaken to assess the effect of different surface microtopograph of Ti-Nb-Zr-Sn alloy on the biological behavior and soft tissue integration of rabbits' lacertus fibroblast. The lacertus fibroblasts of Achilles tendon of rabbits were cultured and inoculated on the surface of smooth Ti-flake (control group), and on the surface of sand blast, microgrooves, thread Ti-flakes respectively (3 treatment groups). The cell's growth ratio and attaching status were examined by MTT test and scanning electron microscopy (SEM). The rabbits' lacertus fibroblasts proliferated regularly on the surface of Ti-flakes, and most results of their inter-group comparison showed statistically significant difference (P<0.05), thus indicating the different effects of different surface microtopographs on cell's proliferation; By SEM, the cells were noted to have no obvious directivity on smooth surface; they attached irregularly on the sand blast surface. But in the other two groups, they were oriented regularly along the texture. The cells were almost shuttle-like on the four kinds of surface except for a part of irregular cells on the sand blast surface, and there were plentiful cell-cell junctions. Under high power lens, we found cells with limpid microvilli in the experiment samples. Owing to the cell's fast proliferation and regular attachment in the experiment, we concluded that the regular microgrooved surface was more suitable for meeting the requirement of the soft tissues' physiological function.
Achilles Tendon ; cytology ; Alloys ; chemistry ; Animals ; Cell Proliferation ; Cells, Cultured ; Fibroblasts ; cytology ; ultrastructure ; Rabbits ; Surface Properties ; Titanium ; chemistry

OBJECTIVETo investigate the effects of preemptive freezing with different temperature and cross-linking methods on the ultrastructure of collagen membrane and its influence on human fibroblast proliferation.

METHODSBovine collagen type I solution in concentration of 10 g/L was preliminarily frozen at -20 degrees C or - 80 degrees C for 12 hours, and lyophilized at -70 degrees C for 48 hours. The diameter of apertures in collagen membranes prepared with two different preliminary temperatures were observed by scanning electron microscope (SEM) and compared. The preliminary freezing temperature of - 80 degrees C was used for the following study. The apertures of collagen membrane performed with cross-linking glutaraldehyde and ultraviolet (UV) radiation cross-linking with glutaraldehyde (double cross - linking) after preliminary freezing were also compared. The proliferation of human fibroblasts inoculated in above cross-linking collagens were assessed by MTT assay, in terms of absorption value.

RESULTSThe mean diameter of apertures of collagen membrane pre-frozen at -20 degrees C was (172 +/- 374 microm, while that at -80 degrees C was (99 +/- 24) microm. The apertures of collagen membrane were reduced in size after glutaraldehyde cross-linking, while those of double cross-linking showed no change in size. There was obvious difference in absorption value of fibroblasts 8 days after seeding between above two cross-linking methods (1.534 +/- 0.013 for glutaraldehyde cross-linking, 3.778 +/- 0.010 for double cross-linking, P < 0.05).

CONCLUSIONThe collagen membrane after preliminary freezing at - 80 degrees C and double cross-linking with UV radiation and glutaraldehyde may be used as a dermal skeleton substitute.

Animals ; Cattle ; Cells, Cultured ; Coculture Techniques ; Collagen ; ultrastructure ; Cross-Linking Reagents ; chemistry ; Dermis ; cytology ; Fibroblasts ; cytology ; drug effects ; radiation effects ; Freezing ; Glutaral ; chemistry ; Humans ; Skin, Artificial ; Tissue Scaffolds ; Ultraviolet Rays

The propagation characteristics of virulent duck plague virus (DPV) in duck embryo fibroblast (DEF) were studied by the method of light microscopy observation of DEF cell culture monolayer, electron microscopy observation of infected DEF cell culture, real-time PCR detecting virus propagation. The results demonstrated that on duck embryo fibroblast a number of plaques were formed by DPV 42 h postinfection. Electron microscopy of the ultrathin section of infected duck embryo fibroblasts demonstrated that the nucleic acid of DPV was round in shape with diameter of 35-45 nm and was often in a cluster in the nucleus of DEF. The nucleocapsid of DPV was round in shape with diameter of 90-100 nm and could be observed both in nucleus and cytoplasm of DEF. The mature DPV which had the structures of envelop and tegument was spherical in shape with diameter of 150-300 nm and was located in cytoplasmic vacuoles. DPV penetrated the DEF cell membrane by direct fusion between the viral envelop and the plasma membrane. Progeny viral nucleic acid was produced in the nucleus and the assembled nucleocapsids obtained the structure of tegument in the cytoplasm and obtained the structure of envelop by budding into the cytoplasmic vesicles. The mature DPV particles were released out of the cell through exocytosis of the cytoplasmic vesicles. Detection of DPV by real-time PCR demonstrated that virus in DEF began its obvious propagation 10 h postinfection and virus amount tended to increase until 30 h postinfection. DPV began to be released into the supernatant 22 h postinfection and the DPV amount peaked 50 h postinfection, when the virus content in DEF and supernatant both underwent approximately 10(3) fold increase. DPV mainly existed in the DEF and the virus content in DEF was 10(2)-10(3) fold than the supernatant.
Animals ; Ducks ; embryology ; virology ; Fibroblasts ; virology ; Herpesviridae ; growth & development ; ultrastructure ; Microscopy, Electron ; Polymerase Chain Reaction

Cell apoptosis induced by duck reovirus (DRV)in duck embryo fibroblasts (DEF) was ascertained by light microscope and electron microscopy, DNA Ladder, flow cytometry and fluorescent microscopy. Typical morphological apoptotic features including cell shrinkage and condensation, margination of nuclear chromatin were observed under light microscope and the formation of apoptotic bodies by electron microscopy. DNA ladder was shown by DNA fragment analysis at 24-144h post infection. Flow cytometry showed that the cell apoptosis appeared at 24h and reached it's crest-time at 72-96h, decreased at 144h. Fluorescent microscopy showed that the apoptotic cells which showed green fluorescence appeared at 24h, the number of dead cells which showed red fluorescence increased with the time went by. The results above confirmed that the apoptosis of DEF was successfully induced by DRV.
Animals ; Apoptosis ; physiology ; Cell Nucleus ; ultrastructure ; Cells, Cultured ; DNA Fragmentation ; Ducks ; Embryo, Nonmammalian ; cytology ; Fibroblasts ; cytology ; ultrastructure ; virology ; Flow Cytometry ; Host-Pathogen Interactions ; Microscopy, Electron, Transmission ; Reoviridae ; physiology