scholarly journals Mechanistic Computational Models of Epithelial Cell Transporters-the Adorned Heroes of Pharmacokinetics

2021 ◽  
Vol 12 ◽  
Author(s):  
Jasia King ◽  
Stefan Giselbrecht ◽  
Roman Truckenmüller ◽  
Aurélie Carlier
Keyword(s):  
Epithelial Cell ◽  
Cell Membrane ◽  
Computational Models ◽  
Epithelial Transport ◽  
Solute Flux ◽  
Tissue Cell ◽  
Mechanistic Models ◽  
Individual Parameter ◽  
Modeling Material

Epithelial membrane transporter kinetics portray an irrefutable role in solute transport in and out of cells. Mechanistic models are used to investigate the transport of solutes at the organ, tissue, cell or membrane scale. Here, we review the recent advancements in using computational models to investigate epithelial transport kinetics on the cell membrane. Various methods have been employed to develop transport phenomena models of solute flux across the epithelial cell membrane. Interestingly, we noted that many models used lumped parameters, such as the Michaelis-Menten kinetics, to simplify the transporter-mediated reaction term. Unfortunately, this assumption neglects transporter numbers or the fact that transport across the membrane may be affected by external cues. In contrast, more recent mechanistic transporter kinetics models account for the transporter number. By creating models closer to reality researchers can investigate the downstream effects of physical or chemical disturbances on the system. Evidently, there is a need to increase the complexity of mechanistic models investigating the solute flux across a membrane to gain more knowledge of transporter-solute interactions by assigning individual parameter values to the transporter kinetics and capturing their dependence on each other. This change results in better pharmacokinetic predictions in larger scale platforms. More reliable and efficient model predictions can be made by creating mechanistic computational models coupled with dedicated in vitro experiments. It is also vital to foster collaborative efforts among transporter kinetics researchers in the modeling, material science and biological fields.

Light Chain LC and TAT-EGFP-HCS of Botulinum Toxin Expression and Biological Function in vitro and in vivo

2019 ◽  
Vol 16 (3) ◽  
pp. 175-180
Author(s):  
Fengjin Hao ◽  
Yueqin Feng ◽  
Yifu Guan
Keyword(s):  
Biological Activity ◽  
Botulinum Toxin ◽  
Cell Membrane ◽  
Western Blot ◽  
Biological Function ◽  
C6 Cells ◽  
Green Fluorescence ◽  
Bv2 Cells

Objective: To verify whether the botulinum toxin heavy chain HCS has specific neuronal targeting function and to confirm whether TAT-EGFP-LC has hydrolyzable SNAP-25 and has transmembrane biological activity. Methods: We constructed the pET-28a-TAT-EGFP-HCS/LC plasmid. After the plasmid is expressed and purified, we co-cultured it with nerve cells or tumors. In addition, we used Western-Blot to identify whether protein LC and TAT-EGFP-LC can digest the protein SNAP-25. Results: Fluorescence imaging showed that PC12, BV2, C6 and HeLa cells all showed green fluorescence, and TAT-EGFP-HCS had the strongest fluorescence. Moreover, TAT-EGFP-LC can hydrolyze intracellular SNAP-25 in PC12 cells, C6 cells, BV2 cells and HeLa, whereas LC alone cannot. In addition, the in vivo protein TAT-EGFP-HCS can penetrate the blood-brain barrier and enter mouse brain tissue. Conclusion: TAT-EGFP-HSC expressed in vitro has neural guidance function and can carry large proteins across the cell membrane without influencing the biological activity.

Met -/- kidneys express epithelial cells that chemotax and form tubules in response to EGF receptor ligands

1997 ◽  
Vol 272 (2) ◽  
pp. F222-F228
Author(s):  
C. Kjelsberg ◽  
H. Sakurai ◽  
K. Spokes ◽  
C. Birchmeier ◽  
I. Drummond ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epithelial Cell ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Growth Factor Receptor ◽  
Receptor Ligands ◽  
Tubule Formation ◽  
Human Papillomavirus 16 ◽  
Immortalized Cells

The growth factor/receptor combination of hepatocyte growth factor (HGF)/c-met has been postulated to be critical for mesenchymal-to-epithelial conversion and tubule formation in the developing kidney. We therefore isolated and immortalized cells from embryonic kidneys of met -/- transgenic mice to determine whether these cells were epithelial and able to chemotax and form tubules in vitro. The cells were immortalized with retrovirus expressing human papillomavirus 16 (HPV 16) E6/E7 genes. Two rapidly dividing clones were isolated and found to express the epithelial cell markers cytokeratin, zonula occludens-1, and E-cadherin but not to express the fibroblast marker vimentin. The met -/- cells were able to chemotax in response to epidermal growth factor and transforming growth factor-alpha (TGF-alpha) and form tubules in vitro in response to TGF-alpha but not HGF. These experiments suggest that the HGF/c-met axis is not essential for epithelial cell development in the embryonic kidney and demonstrate that other growth factors are capable of supporting early tubulogenesis.

An in vitro senescence model of gingival epithelial cell induced by hydrogen peroxide treatment

Odontology ◽  
2021 ◽  
Author(s):  
Sarita Giri ◽  
Ayuko Takada ◽  
Durga Paudel ◽  
Koki Yoshida ◽  
Masae Furukawa ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Epithelial Cell ◽  
Gingival Epithelial Cell ◽  
Hydrogen Peroxide Treatment

scholarly journals Enhanced Piezoelectric Fibered Extracellular Matrix to Promote Cardiomyocyte Maturation and Tissue Formation: A 3D Computational Model

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 135
Author(s):  
Pau Urdeitx ◽  
Mohamed H. Doweidar
Keyword(s):  
Extracellular Matrix ◽  
Cell Migration ◽  
Computational Models ◽  
Cell Junctions ◽  
Tissue Formation ◽  
Cardiac Muscle Cells ◽  
Cell Processes ◽  
Electrical Stimuli ◽  
Cell Cell

Mechanical and electrical stimuli play a key role in tissue formation, guiding cell processes such as cell migration, differentiation, maturation, and apoptosis. Monitoring and controlling these stimuli on in vitro experiments is not straightforward due to the coupling of these different stimuli. In addition, active and reciprocal cell–cell and cell–extracellular matrix interactions are essential to be considered during formation of complex tissue such as myocardial tissue. In this sense, computational models can offer new perspectives and key information on the cell microenvironment. Thus, we present a new computational 3D model, based on the Finite Element Method, where a complex extracellular matrix with piezoelectric properties interacts with cardiac muscle cells during the first steps of tissue formation. This model includes collective behavior and cell processes such as cell migration, maturation, differentiation, proliferation, and apoptosis. The model has employed to study the initial stages of in vitro cardiac aggregate formation, considering cell–cell junctions, under different extracellular matrix configurations. Three different cases have been purposed to evaluate cell behavior in fibered, mechanically stimulated fibered, and mechanically stimulated piezoelectric fibered extra-cellular matrix. In this last case, the cells are guided by the coupling of mechanical and electrical stimuli. Accordingly, the obtained results show the formation of more elongated groups and enhancement in cell proliferation.

scholarly journals Kynurenic Acid Accelerates Healing of Corneal Epithelium In Vitro and In Vivo

2021 ◽  
Vol 14 (8) ◽  
pp. 753
Author(s):  
Anna Matysik-Woźniak ◽  
Waldemar A. Turski ◽  
Monika Turska ◽  
Roman Paduch ◽  
Mirosław Łańcut ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Corneal Epithelium ◽  
Kynurenic Acid ◽  
Pharmaceutical Products ◽  
Corneal Epithelial Cell ◽  
Eye Drops ◽  
Conjunctival Epithelium ◽  
Corneal Erosion

Kynurenic acid (KYNA) is an endogenous compound with a multidirectional effect. It possesses antiapoptotic, anti-inflammatory, and antioxidative properties that may be beneficial in the treatment of corneal injuries. Moreover, KYNA has been used successfully to improve the healing outcome of skin wounds. The aim of the present study is to evaluate the effects of KYNA on corneal and conjunctival cells in vitro and the re-epithelization of corneal erosion in rabbits in vivo. Normal human corneal epithelial cell (10.014 pRSV-T) and conjunctival epithelial cell (HC0597) lines were used. Cellular metabolism, cell viability, transwell migration, and the secretion of IL-1β, IL-6, and IL-10 were determined. In rabbits, after corneal de-epithelization, eye drops containing 0.002% and 1% KYNA were applied five times a day until full recovery. KYNA decreased metabolism but did not affect the proliferation of the corneal epithelium. It decreased both the metabolism and proliferation of conjunctival epithelium. KYNA enhanced the migration of corneal but not conjunctival epithelial cells. KYNA reduced the secretion of IL-1β and IL-6 from the corneal epithelium, leaving IL-10 secretion unaffected. The release of all studied cytokines from the conjunctival epithelium exposed to KYNA was unchanged. KYNA at higher concentration accelerated the healing of the corneal epithelium. These favorable properties of KYNA suggest that KYNA containing topical pharmaceutical products can be used in the treatment of ocular surface diseases.

scholarly journals DnaA, the Initiator of Escherichia coliChromosomal Replication, Is Located at the Cell Membrane

2000 ◽  
Vol 182 (9) ◽  
pp. 2604-2610 ◽  
Author(s):  
Gillian Newman ◽  
Elliott Crooke
Keyword(s):  
Cell Membrane ◽  
Spatial Organization ◽  
Active Form ◽  
Chromosomal Replication ◽  
E Coli ◽  
Dnaa Protein ◽  
Section Electron ◽  
Acidic Phospholipids

ABSTRACT Given the lack of a nucleus in prokaryotic cells, the significance of spatial organization in bacterial chromosome replication is only beginning to be fully appreciated. DnaA protein, the initiator of chromosomal replication in Escherichia coli, is purified as a soluble protein, and in vitro it efficiently initiates replication of minichromosomes in membrane-free DNA synthesis reactions. However, its conversion from a replicatively inactive to an active form in vitro occurs through its association with acidic phospholipids in a lipid bilayer. To determine whether the in situ residence of DnaA protein is cytoplasmic, membrane associated, or both, we examined the cellular location of DnaA using immunogold cryothin-section electron microscopy and immunofluorescence. Both of these methods revealed that DnaA is localized at the cell membrane, further suggesting that initiation of chromosomal replication in E. coli is a membrane-affiliated event.

scholarly journals Intracellular host cell membrane remodelling induced by SARS‐CoV‐2 infection in vitro

2021 ◽  
Author(s):  
Lucio Ayres Caldas ◽  
Fabiana Avila Carneiro ◽  
Fabio Luis Monteiro ◽  
Ingrid Augusto ◽  
Luiza Mendonça Higa ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Host Cell ◽  
Host Cell Membrane

Transforming growth factor-alpha enhances alveolar epithelial cell repair in a new in vitro model

1994 ◽  
Vol 267 (6) ◽  
pp. L728-L738 ◽  
Author(s):  
F. Kheradmand ◽  
H. G. Folkesson ◽  
L. Shum ◽  
R. Derynk ◽  
R. Pytela ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epithelial Cell ◽  
Wound Repair ◽  
Wound Closure ◽  
Transforming Growth Factor ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial ◽  
Factor Alpha ◽  
Vitro Model

Alveolar epithelial type II cells are essential for regenerating an intact alveolar barrier after destruction of type I cells in vivo. The first objective of these experimental studies was to develop an in vitro model to quantify alveolar epithelial cell wound repair. The second objective was to investigate mechanisms of alveolar epithelial cell wound healing by studying the effects of serum and transforming growth factor-alpha (TGF-alpha) on wound closure. Primary cultures of rat alveolar type II cells were prepared by standard methods and grown to form confluent monolayers in 48 h. Then a wound was made by denuding an area (mean initial area of 2.1 +/- 0.6 mm2) of the monolayer. Re-epithelialization of the denuded area over time in the presence or absence of serum was measured using quantitative measurements from time-lapse video microscopy. The half time of wound healing was significantly enhanced in the presence of serum compared with serum-free conditions (2.4 +/- 0.2 vs. 17.4 +/- 0.8 h, P < 0.001). We then tested the hypothesis that TGF-alpha is an important growth factor for stimulating wound repair of alveolar epithelial cells. Exogenous addition of TGF-alpha in serum-free medium resulted in a significantly more rapid wound closure, and, furthermore, the addition of a monoclonal antibody to TGF-alpha in the presence of serum significantly decreased fourfold the rate of wound closure. Measurement of internuclear cell distance confirmed that both cell motility and cell spreading were responsible for closure of the wound. These data demonstrate that 1) the mechanisms of alveolar cell repair can be studied in vitro and that 2) TGF-alpha is a potent growth factor that enhances in vitro alveolar epithelial cell wound closure.

scholarly journals c-Src inactivation reduces renal epithelial cell-matrix adhesion, proliferation, and cyst formation

2011 ◽  
Vol 301 (2) ◽  
pp. C522-C529 ◽  
Author(s):  
Justine Elliott ◽  
Nadezhda N. Zheleznova ◽  
Patricia D. Wilson
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Collecting Duct ◽  
Specific Inhibitor ◽  
Cell Phenotype ◽  
Epithelial Cell Proliferation ◽  
Matrix Adhesion ◽  
Cyst Lining

c-Src is a non-receptor tyrosine kinase whose activity is induced by phosphorylation at Y418 and translocation from the cytoplasm to the cell membrane. Increased activity of c-Src has been associated with cell proliferation, matrix adhesion, motility, and apoptosis in tumors. Immunohistochemistry suggested that activated (pY418)-Src activity is increased in cyst-lining autosomal dominant polycystic kidney disease (ADPKD) epithelial cells in human and mouse ADPKD. Western blot analysis showed that SKI-606 (Wyeth) is a specific inhibitor of pY418-Src without demonstrable effects on epidermal growth factor receptor or ErbB2 activity in renal epithelia. In vitro studies on mouse inner medullary collecting duct (mIMCD) cells and human ADPKD cyst-lining epithelial cells showed that SKI-606 inhibited epithelial cell proliferation over a 24-h time frame. In addition, SKI-606 treatment caused a striking statistically significant decrease in adhesion of mIMCD and human ADPKD to extracellular collagen matrix. Retained viability of unattached cells was consistent with a primary effect on epithelial cell anchorage dependence mediated by the loss of extracellular matrix (ECM)-attachment due to α2β1-integrin function. SKI-606-mediated attenuation of the human ADPKD hyperproliferative and hyper-ECM-adhesive epithelial cell phenotype in vitro was paralleled by retardation of the renal cystic phenotype of Pkd1 orthologous ADPKD heterozygous mice in vivo. This suggests that SKI-606 has dual effects on cystic epithelial cell proliferation and ECM adhesion and may have therapeutic potential for ADPKD patients.

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