scholarly journals Cells/colony motion of oral keratinocytes determined by non-invasive and quantitative measurement using optical flow predicts epithelial regenerative capacity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emi Hoshikawa ◽  
Taisuke Sato ◽  
Kenta Haga ◽  
Ayako Suzuki ◽  
Ryota Kobayashi ◽  
...  

AbstractCells/colony motion determined by non-invasive, quantitative measurements using the optical flow (OF) algorithm can indicate the oral keratinocyte proliferative capacity in early-phase primary cultures. This study aimed to determine a threshold for the cells/colony motion index to detect substandard cell populations in a subsequent subculture before manufacturing a tissue-engineered oral mucosa graft and to investigate the correlation with the epithelial regenerative capacity. The distinctive proliferating pattern of first-passage [passage 1 (p1)] cells reveals the motion of p1 cells/colonies, which can be measured in a non-invasive, quantitative manner using OF with fewer full-screen imaging analyses and cell segmentations. Our results demonstrate that the motion index lower than 40 μm/h reflects cellular damages by experimental metabolic challenges although this value shall only apply in case of our culture system. Nonetheless, the motion index can be used as the threshold to determine the quality of cultured cells while it may be affected by any different culture conditions. Because the p1 cells/colony motion index is correlated with epithelial regenerative capacity, it is a reliable index for quality control of oral keratinocytes.

2021 ◽  
Author(s):  
Emi Hoshikawa ◽  
Taisuke Sato ◽  
Kenta Haga ◽  
Ayako Suzuki ◽  
Ryota Kobayashi ◽  
...  

Abstract Cell/colony motion determined by non-invasive, quantitative measurements using the optical flow (OF) algorithm can indicate the oral keratinocyte proliferative capacity in early-phase primary cultures. This study aimed to determine a threshold for the cell/colony motion index to detect substandard cell populations in a subsequent subculture before manufacturing a tissue-engineered oral mucosa graft and to investigate the correlation with the epithelial regenerative capacity. The distinctive proliferating pattern of first-passage (passage 1 (p1)) cells reveals the motion of p1 cells/colonies, which can be measured in a non-invasive, quantitative manner using OF with fewer full-screen imaging analyses and cell segmentations. Our results demonstrate that the motion index lower than 40 μm/hour reflects cellular damages by experimental metabolic challenges and can be used as the threshold to determine the quality of cultured cells. Because the p1 cell/colony motion index is correlated with epithelial regenerative capacity, it is a reliable index for quality control of oral keratinocytes.


1986 ◽  
Vol 239 (1) ◽  
pp. 179-183 ◽  
Author(s):  
S R Quinones ◽  
D S Neblock ◽  
R A Berg

Collagen synthesis and mRNA amounts for the alpha 1 and alpha 2 polypeptide chains of Type I collagen were measured in embryonic-chick tendons and in tendon cells both in suspension and in primary cultures. The percentage of protein production represented by collagen in suspension-cultured cells was initially the same as in the intact tendon; however, on an hourly basis, there was actually a steady decline in collagen production by suspended cells. Collagen production in primary cultures of chick tendon fibroblasts was decreased when compared with intact tendon, even though ascorbate-supplemented primary cultures were able to maintain higher rates of collagen production than were non-supplemented cultures. The amounts of mRNA for alpha 1(I) and alpha 2(I) polypeptide chains of collagen responded in similar fashions to different culture conditions and were compared with the amounts of mRNA for beta-actin. In primary cultures the available alpha 1 and alpha 2 collagen mRNAs support proportionately higher collagen production than in the intact tendon. However, the ratio of alpha 1/alpha 2 mRNA and polypeptide-chain synthesis did not remain 2:1, but increased with the concomitant production of Type I trimers composed of three alpha 1 chains. Removal of fibroblasts from their environment in vivo appears to alter the amounts of mRNA for alpha 1 and alpha 2 chains and to alter the utilization of those mRNAs for polypeptide synthesis.


1998 ◽  
Vol 275 (5) ◽  
pp. F651-F663 ◽  
Author(s):  
Isabelle Rubera ◽  
Michel Tauc ◽  
Michel Bidet ◽  
Chantal Poujeol ◽  
Béatrice Cuiller ◽  
...  

Cl− conductances were studied in cultured rabbit proximal convoluted tubule (PCT) epithelial cells and compared with those measured in cultured distal bright convoluted tubule (DCTb) epithelial cells. Using the whole cell patch-clamp technique, three types of Cl− conductances were identified in DCTb cultured cells. These consisted of volume-sensitive, Ca2+-activated, and forskolin-activated Cl−currents. In PCT cultured cells, only volume-sensitive and Ca2+-activated Cl− currents were recorded. The characteristics of Ca2+-activated currents in PCT cells closely resembled those in DCTb cells. Volume-sensitive Cl− currents could be elicited both in PCT and in DCTb cells by hypotonic stress. The pharmacological profile of this conductance was established for both cell types. Forskolin activated a linear Cl− current in DCTb cells but not in PCT cells. This conductance was insensitive to DIDS and corresponds to cystic fibrosis transmembrane conductance regulator (CFTR)-like channels. Quantitative measurements of SPQ fluorescence showed that only the apical membrane of DCTb cells possessed a Cl− pathway that was sensitive to forskolin. RT-PCR experiments showed the presence of CFTR mRNA in both cultures, whereas immunostaining experiments revealed the expression of CFTR in DCTb cells only. The physiological role of the different types of channels is discussed.


1989 ◽  
Vol 256 (3) ◽  
pp. C532-C539 ◽  
Author(s):  
M. J. Tang ◽  
K. R. Suresh ◽  
R. L. Tannen

Renal proximal tubular epithelia were used to assess the factors responsible for the induction of glycolysis in cultured cells. Primary cultures of rabbit proximal tubules, which achieved confluency at 6 days, exhibited hormonal responsiveness and brush-border characteristics typical of proximal tubular cells. Beginning at day 4, these cultured cells exhibited increased glycolytic metabolism reflected by enhanced glucose uptake and lactate production, along with parallel increases in activity of the glycolytic enzymes, pyruvate kinase and lactate dehydrogenase. The gluconeogenic enzymes, phosphoenolpyruvate carboxykinase (PEPCK) and fructose-1,6-bisphosphatase (FDP), were downregulated, and the cultured cells exhibited lower oxygen consumption rates than fresh tubules. Cells grown on a rocker, to mitigate hypoxia, exhibited a metabolic and enzymatic profile similar to cells grown under still conditions. ATP levels in cultured cells were higher than in fresh tubules. Furthermore, pyruvate kinase activity was higher in cells grown in media containing 0.5 as contrasted with 25 mM glucose. The enhanced glycolytic metabolism exhibited by cultured proximal tubular cells appears to be a characteristic of proliferation and is not a response to hypoxia, the Pasteur effect, or environmental glucose.


Endocrinology ◽  
1998 ◽  
Vol 139 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Thomas O. Carpenter ◽  
Kathleen C. Moltz ◽  
Bruce Ellis ◽  
Monica Andreoli ◽  
Thomas L. McCarthy ◽  
...  

Abstract Rickets and osteomalacia are characteristic features of the Hyp mouse model of human X-linked hypophosphatemia. Hyp mice demonstrate elevated circulating osteocalcin levels, as well as altered regulation of osteocalcin by 1,25(OH)2D3. Whether this osteocalcin abnormality is intrinsic to the osteoblast, or mediated by the in vivo milieu, has not been established. We therefore characterized osteocalcin production and its regulation by 1,25(OH)2D3 in primary cultures of murine osteoblasts and examined osteocalcin and its messenger RNA in response to 1,25(OH)2D3 in cultures of Hyp mouse-derived osteoblasts. Cell viability and osteocalcin production are optimal when murine cells are harvested within 36 h of age. Murine primary osteoblast cultures mineralize and produce osteocalcin in a maturation-dependent fashion (as demonstrated in other species), and continuous exposure to 1,25(OH)2D3, beginning at day 9 of culture, inhibits osteoblast differentiation and osteocalcin production and prevents mineralization of the culture. However, in contrast to other species, exposure to 1,25(OH)2D3, added later (days 17–25) in culture, does not stimulate osteocalcin but arrests osteocalcin production at current levels. Ambient media levels of osteocalcin were no different in cultures from Hyp mice and their normal litter mates, and the down-regulatory response to 1,25(OH)2D3 was comparable in cultures from normal and Hyp mice. Furthermore, expression of osteocalcin messenger RNA in murine cultures is reduced with exposure to 1,25(OH)2D3, and there is no difference between normal and Hyp cultures in this response. Thus, primary murine osteoblasts manifest a species-specific effect of 1,25(OH)2D3 on osteocalcin production. Furthermore, the increased serum osteocalcin production seen in intact Hyp mice, and the altered response to 1,25(OH)2D3 in Hyp mice, are not observed in osteoblast cultures derived from the mutant strain. These data indicate that abnormalities of osteocalcin described in intact Hyp mice require factors other than those present in cultured cells.


2020 ◽  
Author(s):  
Emily Swanzey ◽  
Thomas F. McNamara ◽  
Effie Apostolou ◽  
Mamta Tahiliani ◽  
Matthias Stadtfeld

SummaryCultured pluripotent cells accumulate detrimental epigenetic alterations, including DNA methylation changes at imprinted genes known as loss-of-imprinting (LOI). Despite the substantial biomedical relevance of this phenomenon, the molecular cause of this epigenetic instability in pluripotent cells remains unknown. While the occurrence of LOI is generally considered a stochastic phenomenon, here we document a strong genetic determinant that segregates mouse pluripotent cells into epigenetically stable and unstable cell lines. Unstable lines exhibit hypermethylation at Dlk1-Dio3 and select other imprinted loci, which is associated with impaired developmental potential. Stimulation of demethylases by ascorbic acid prevents LOI and can preserve developmental potential. Susceptibility to LOI greatly differs between commonly used mouse strains, which we utilize to map a causal region on chromosome 13 with Quantitative Trait Locus (QTL) analysis. Our observations identify a strong genetic determinant of locus-specific epigenetic abnormalities in pluripotent cells and provide a non-invasive way to suppress them. This highlights the importance of considering genetics in conjunction with culture conditions for assuring the quality of pluripotent cells for biomedical applications.


2005 ◽  
Vol 17 (2) ◽  
pp. 167 ◽  
Author(s):  
A.M. Giraldo ◽  
J.W. Lynn ◽  
C.E. Pope ◽  
R.A. Godke ◽  
K.R. Bondioli

The low efficiency of nuclear transfer (NT) has been related to factors such as mitochondria heteroplasmy, failure of genomic activation, and asynchrony between the donor karyoplast and recipient cytoplast. Few studies have characterized donor cell lines in terms of proliferative capacity and chromosomal stability. It is known that suboptimal culture conditions can induce chromosomal abnormalities, and the use of aneuploid donor cells during NT can lead to a high incidence of abnormal cloned embryos (Giraldo et al. 2004 Reprod. Fertil. Dev. 16, 124 abst). The purpose of this study was to determine the lifespan and chromosomal stability of bovine and porcine fetal cells. Four bovine and four porcine fibroblast cells lines were established from 50-day and 40-day fetuses, respectively. Cells were cultured in DMEM medium supplemented with 10% fetal bovine serum and 1% penicillin and streptomycin at 37°C in 5% CO2. Each cell line was passaged to senescence. Total population doublings (PDs) and cell cycle duration were calculated. To determine the chromosome numbers at different PDs, cells were synchronized in metaphase, fixed, and stained. ANOVA and chi-square tests were used to analyze differences in PDs and proportion of aneuploid cells between cell lines, respectively (P < 0.05). The results show that proliferative capacity was not different between cell lines derived from the same species. Cell lines derived from bovine and porcine fetuses had different in vitro lifespans (33 PDs vs. 42 PDs, respectively; P < 0.05). The mean length of the cell cycles for both bovine and porcine fetal fibroblasts was ∼28 h. The percentage of aneupliod cells in both bovine and porcine fetal cell lines increased progressively with duration of culture (see Table) and was high throughout the study. The proliferative capacity of cultured cells was similar within individuals of the same species, but growth characteristics differed between fetal bovine and porcine cell lines. The progressive increase of aneuploid cells could be due to suboptimal culture conditions or unusual chromosome instability in the particular fetuses used. These data demonstrate the importance of determining chromosome content and the use of cells at early passages to decrease the percentage of aneuploid reconstructed embryos and increase the efficiency of NT.


1995 ◽  
Vol 269 (5) ◽  
pp. L561-L566 ◽  
Author(s):  
B. Q. Shen ◽  
R. J. Mrsny ◽  
W. E. Finkbeiner ◽  
J. H. Widdicombe

We have tested two hypotheses: 1) the cystic fibrosis transmembrane conductance regulator (CFTR) represents the predominant Cl conductance in the apical membrane of human tracheal epithelium, and 2) CFTR in this tissue is close to maximally activated under baseline conditions. In support of the first hypothesis, we found 1) when the level of differentiation of cultures was varied by varying the culture conditions, there was a significant positive correlation between the levels of CFTR and the magnitude of mediator-induced Cl secretion. 2) Amiloride-insensitive baseline short-circuit current (Isc) and mediator-induced increases in Isc were inhibited by diphenylamine-2-carboxylic acid (DPAC) but not by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), a pharmacology consistent with passage of apical membrane Cl current through CFTR; Ca-activated Cl channels are inhibited by DIDS but not by DPAC. 3) Raising temperature from 22 degrees to 37 degrees C increased 125I efflux, and this increase was inhibited by DPAC and blockers of protein kinase A, but not by DIDS or 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester. In support of the second hypothesis, we have earlier shown [M. Yamaya, W.E. Finkbeiner, S.Y. Chun, and J.H. Widdicombe. Am. J. Physiol. 262 (Lung Cell. Mol. Physiol. 6): L713-L724, 1992] that adenosine 3',5'-cyclic monophosphate (cAMP)-elevating agents are essentially without effect on Isc across primary cultures of human tracheal epithelium. Here, we further show that these agents are also usually without effect on 125I efflux; the mean increase in efflux in response to elevating cAMP was approximately 20% that of raising temperature from 22 degrees to 37 degrees C.


2018 ◽  
Vol 475 (6) ◽  
pp. 1129-1139 ◽  
Author(s):  
Atsushi Yoshida ◽  
Yosuke Funato ◽  
Hiroaki Miki

Phosphatase of regenerating liver (PRL) is highly expressed in malignant cancers and promotes cancer progression. Recent studies have suggested its functional relationship with Mg2+, but the importance and molecular details of this relationship remain unknown. Here, we report that PRL expression is regulated by Mg2+ and PRL protects cells from apoptosis under Mg2+-depleted conditions. When cultured cells were subjected to Mg2+ depletion, endogenous PRL protein levels increased significantly. siRNA-mediated knockdown of endogenous PRL did not significantly affect cell proliferation under normal culture conditions, but it increased cell death after Mg2+ depletion. Imaging analyses with a fluorescent probe for Mg2+ showed that PRL knockdown severely reduced intracellular Mg2+ levels, indicating a role for PRL in maintaining intracellular Mg2+. We also examined the mechanism of augmented expression of PRL proteins and found that PRL mRNA transcription was stimulated by Mg2+ depletion. A series of analyses revealed the activation and the crucial importance of signal transducer and activator of transcription 1 in this process. Collectively, these results implicate PRL in maintaining cellular Mg2+ homeostasis.


2004 ◽  
Vol 14 (4) ◽  
pp. 607-615 ◽  
Author(s):  
P. Kornblith ◽  
R. L. Ochs ◽  
A. Wells ◽  
M. J. Gabrin ◽  
J. Piwowar ◽  
...  

The treatment of ovarian cancer principally relies on the use of platinum and taxane chemotherapeutic agents. Short-term clinical results have been encouraging, but long-term responses remain limited. In this report, an in vitro assay system that utilizes cells grown from human tumor explants has been used to quantitatively evaluate responses to relevant concentrations of alternative chemotherapeutic agents. The results suggest that there are significant differences in the responses of explant-derived cultured cells to the different agents tested. In an evaluation of 276 primary ovarian cancer specimens, five nonstandard drugs were tested in 51 cases. Of these 51 cases, cyclophosphamide had the highest rate of response at 67%, followed by doxorubicin at 61%, gemcitabine at 49%, etoposide at 48%, and topotecan at 14%. Venn diagrams, representing the in vitro responses to the platins and taxanes, as well as the responses to the nonstandard drugs, illustrate that there clearly are distinct differences among patients in a given population. These data underscore the potential importance of evaluating each patient's response to a number of different drugs to optimize the therapeutic decision-making process.


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