Carboxyfluorescein (CFSE) Labelling of Hepatocytes for Short-Term Localization following Intraportal Transplantation

1994 ◽  
Vol 3 (5) ◽  
pp. 397-408 ◽  
Author(s):  
Hikaru Fujioka ◽  
Peter J. Hunt ◽  
Jacek Rozga ◽  
Guo-Du Wu ◽  
Donald V. Cramer ◽  
...  

Renewed interest in the transplantation of isolated hepatocytes into the liver as a potential therapy for liver disease has stimulated the development of methods for the identification of donor cells within the recipient organ. We describe a method for cellular tagging and in vivo identification of intraportally transplanted hepatocytes using an intracellular fluorescent dye, 5(6)-carboxyfluorescein diacetate, succinimidyl-ester (CFSE). Rat and porcine hepatocytes were isolated and labelled with CFSE. The optimal conditions for labelling consisted of a buffered saline suspension of hepatocytes (5 × 106 cells/mL) in 20.0 μM CFSE incubated for 15 min at 37°C. In vitro, labelled hepatocytes were cultured either on fibronectin-coated chamber slides or in culture flasks. Cultures were evaluated in situ by fluorescence photomicrography or by fluorescence-activated cell sorting (FACS) after cell detachment. Cell viability was assessed serially and cultured, labelled hepatocytes retained the dye for up to 3 wk (last day of study). CFSE did not effect hepatocyte viability and there was no evidence of intercellular diffusion of the dye. In vivo, syngeneic Lewis rats underwent selective portal vein infusion of freshly isolated, labelled hepatocytes (2.0 × 107 cells/2.0 mL saline/animal) into the posterior liver lobes. All recipients were sacrificed 48 h and 96 h later and their livers examined. Transplanted hepatocytes were identified by fluorescence microscopy in tissue sections and by FACS following collagenase digestion of the liver tissue. CFSE persisted in a population of viable, engrafted hepatocytes. FACS analysis demonstrated that 9 ± 3% of the hepatocytes in the posterior liver lobes were labelled 48 and 96 h after transplantation. At 96 h following transplantation, multiple engrafted hepatocytes could be observed by fluorescence microscopy around the central veins. CFSE labelling allows for both in vitro identification and in vivo localization of donor hepatocytes. Furthermore, it appears to be more stable and specific for labelling hepatocytes than other tested dyes (especially DiI).

1991 ◽  
Vol 69 (2) ◽  
pp. 298-304 ◽  
Author(s):  
Lawrence L. Spriet

Anaerobic energy production is essential for the production of muscular tension when the demand for energy is greater than can be provided aerobically and when oxygen is in short supply. The largest source of anaerobic energy is from the glycolytic pathway. With sustained tetanic contractions, muscle glycolytic activity is high and hydrogen ions (H+) accumulate while tension production decreases. The increasing [H+] and decreasing tension led to the suggestion that H+ inhibits the activity of the regulatory glycolytic enzyme phosphofructokinase (PFK). Early in vitro work confirmed the H+ sensitivity of PFK in the test tube, indicating that little PFK activity should persist at a pH of 6.9–7.0. However, in situ and in vivo experiments suggested that significant PFK activity was maintained during intense contractions when muscle pH decreased to 6.4–6.6. There are several concerns associated with the application of in vitro findings to in vivo exercise situations: (i) there is little in vitro work in mammalian skeletal muscle with substrate and modulator concentrations representative of exercise, (ii) most in vitro analyses of PFK activity are performed following the dilution of the enzyme in mediums with low protein concentration, and (iii) do the modulators identified in vitro exist in high enough in vivo concentrations at rest and during exercise to contribute to the regulation of PFK? More recent in vitro and in situ PFK experiments have overcome some of these concerns. They confirm that during intense, short-term tetanic contractions, PFK activity is well matched to the ATP demand despite decreases in pH to ~6.4–6.5. A combination of decreased inhibitor (ATP) and increased substrate (fructose 6-phosphate) contents coupled with increases in the contents of several positive modulators may be responsible for the maintained PFK activity. This combination reduces the pH-dependent ATP inhibition of PFK and extends the physiological pH range of the enzyme to the range normally measured during this type of muscular activity.Key words: glycolysis, phosphofructokinase, anaerobic metabolism, acidosis.


Author(s):  
K. M. Pichler ◽  
D. Weinmann ◽  
S. Schmidt ◽  
B. Kubista ◽  
R. Lass ◽  
...  

AbstractThis work aimed to study the dysregulated network of galectins in OA chondrocyte pellets, and to assess whether their recently discovered activity as molecular switches of functional biomarkers results in degradation of extracellular matrix in vitro. Scaffold-free 3D pellet cultures were established of human OA chondrocytes. Expression and secretion of galectin(Gal)-1, -3, and -8 were monitored relative to 2D cultures or clinical tissue sections by RT-qPCR, immunohistochemistry and ELISAs. Exposure of 2D and 3D cultures to an in vivo-like galectin mixture (Gal-1 and Gal-8: 5 µg/ml, Gal-3: 1 µg/ml) was followed by the assessment of pellet size, immunohistochemical matrix staining, and/or quantification of MMP-1, -3, and -13. Application of inhibitors of NF-κB activation probed into the potential of intervening with galectin-induced matrix degradation. Galectin profiling revealed maintained dysregulation of Gal-1, -3, and -8 in pellet cultures, resembling the OA situation in situ. The presence of the galectin mixture promoted marked reduction of pellet size and loss of collagen type II-rich extracellular matrix, accompanied by the upregulation of MMP-1, -3, and -13. Inhibition of p65-phosphorylation by caffeic acid phenethyl ester effectively alleviated the detrimental effects of galectins, resulting in downregulated MMP secretion, reduced matrix breakdown and augmented pellet size. This study suggests that the dysregulated galectin network in OA cartilage leads to extracellular matrix breakdown, and provides encouraging evidence of the feasible inhibition of galectin-triggered activities. OA chondrocyte pellets have the potential to serve as in vitro disease model for further studies on galectins in OA onset and progression.


2003 ◽  
Vol 198 (12) ◽  
pp. 1807-1815 ◽  
Author(s):  
JiChu Li ◽  
Gail Huston ◽  
Susan L. Swain

After transfer to adoptive hosts, in vitro–generated CD4 effectors can become long-lived memory cells, but the factors regulating this transition are unknown. We find that low doses of interleukin (IL) 7 enhance survival of effectors in vitro without driving their division. When in vitro–generated effectors are transferred to normal intact adoptive hosts, they survive and rapidly become small resting cells with a memory phenotype. CD4 effectors generated from wild-type versus IL-7 receptor−/− mice were transferred to adoptive hosts, including intact mice and those deficient in IL-7. In each case, the response to IL-7 was critical for good recovery of donor cells after 5–7 d. Recovery was also IL-7–dependent in Class II hosts where division was minimal. Blocking antibodies to IL-7 dramatically decreased short-term recovery of transferred effectors in vivo without affecting their division. These data indicate that IL-7 plays a critical role in promoting memory CD4 T cell generation by providing survival signals, which allow effectors to successfully become resting memory cells.


Development ◽  
1981 ◽  
Vol 64 (1) ◽  
pp. 87-104
Author(s):  
R. S. P. Beddington

The potency of 8th day mouse embryonic ectoderm cells has been studied by injecting them into synchronous embryos which were subsequently cultured for 36 h. The development of injected embryos in vitro was comparable to that of embryos maintained in vivo. Tritiated thymidine was used to label the donor cells so that chimaerism could be analysed histologically. The results demonstrate the pluripotency of embryonic ectoderm in situ in the late primitive-streak-stage embryo. In addition, the patterns of donor cell colonization vary according to the site of origin and injection of the donor tissue.


1999 ◽  
Vol 1999 ◽  
pp. 105-105
Author(s):  
D. Hurst ◽  
D. L. Romney ◽  
A. H. Murray

Parameters from in vitro gas production and in situ degradability are often used to predict digestibility and intake in vivo. However, these methods use dried ground feed samples and cannot be expected to estimate the effect of changes in physical form or particle size. Previous work (Romney and Gill 1998) has indicated that short term intake rate (STIR) values showed potential to rank a variety of feeds in terms of their ad libitum dry matter intake, rate of passage and digestibility. Since STIR values are determined on feeds “as offered” it is likely they will reflect the effects of physical structure on in vivo parameters. The present work examines whether measurement of STIR values can be used to predict in vivo responses to changes in particle size distribution in chopped forages.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


2020 ◽  
Author(s):  
Wenhao Zhou ◽  
Teng Zhang ◽  
Jianglong Yan ◽  
QiYao Li ◽  
Panpan Xiong ◽  
...  

Author(s):  
Daniel L. Villeneuve ◽  
Brett R. Blackwell ◽  
Jenna E. Cavallin ◽  
Wan‐Yun Cheng ◽  
David J. Feifarek ◽  
...  

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 904
Author(s):  
Irin Tanaudommongkon ◽  
Asama Tanaudommongkon ◽  
Xiaowei Dong

Most antiretroviral medications for human immunodeficiency virus treatment and prevention require high levels of patient adherence, such that medications need to be administered daily without missing doses. Here, a long-acting subcutaneous injection of lopinavir (LPV) in combination with ritonavir (RTV) using in situ self-assembly nanoparticles (ISNPs) was developed to potentially overcome adherence barriers. The ISNP approach can improve the pharmacokinetic profiles of the drugs. The ISNPs were characterized in terms of particle size, drug entrapment efficiency, drug loading, in vitro release study, and in vivo pharmacokinetic study. LPV/RTV ISNPs were 167.8 nm in size, with a polydispersity index of less than 0.35. The entrapment efficiency was over 98% for both LPV and RTV, with drug loadings of 25% LPV and 6.3% RTV. A slow release rate of LPV was observed at about 20% on day 5, followed by a sustained release beyond 14 days. RTV released faster than LPV in the first 5 days and slower than LPV thereafter. LPV trough concentration remained above 160 ng/mL and RTV trough concentration was above 50 ng/mL after 6 days with one subcutaneous injection. Overall, the ISNP-based LPV/RTV injection showed sustained release profiles in both in vitro and in vivo studies.


Sign in / Sign up

Export Citation Format

Share Document