scholarly journals Morphological Changes in Astrocytes by Self-Oxidation of Dopamine to Polydopamine and Quantification of Dopamine through Multivariate Regression Analysis of Polydopamine Images

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2483
Author(s):  
Anik Karan ◽  
Elnaz Khezerlou ◽  
Farnaz Rezaei ◽  
Leon Iasemidis ◽  
Mark A. DeCoster

Astrocytes, also known as astroglia, are important cells for the structural support of neurons as well as for biochemical balance in the central nervous system (CNS). In this study, the polymerization of dopamine (DA) to polydopamine (PDA) and its effect on astrocytes was investigated. The polymerization of DA, being directly proportional to the DA concentration, raises the prospect of detecting DA concentration from PDA optically using image-processing techniques. It was found here that DA, a naturally occurring neurotransmitter, significantly altered astrocyte cell number, morphology, and metabolism, compared to astrocytes in the absence of DA. Along with these effects on astrocytes, the polymerization of DA to PDA was tracked optically in the same cell culture wells. This polymerization process led to a unique methodology based on multivariate regression analysis that quantified the concentration of DA from optical images of astrocyte cell culture media. Therefore, this developed methodology, combined with conventional imaging equipment, could be used in place of high-end and expensive analytical chemistry instruments, such as spectrophotometry, mass spectrometry, and fluorescence techniques, for quantification of the concentration of DA after polymerization to PDA under in vitro and potentially in vivo conditions.

1999 ◽  
Vol 340 (1) ◽  
pp. 309-320 ◽  
Author(s):  
Sikha Bettina MUKHERJEE ◽  
S. ARAVINDA ◽  
B. GOPALAKRISHNAN ◽  
Sushma NAGPAL ◽  
Dinakar M. SALUNKE ◽  
...  

The seminiferous tubular fluid (STF) provides the microenvironment necessary for spermatogenesis in the adluminal compartment of the seminiferous tubule (ST), primarily through secretions of the Sertoli cell. Earlier studies from this laboratory demonstrated the presence of glutathione S-transferase (GST) in STF collected from adult rat testis and in the spent media of ST cultures. This study describes the cellular source, isoform composition and possible function of GSTs in the STF. The major GST isoforms present in STF in vivo share extensive N-terminal similarity with rat GSTM1 (rGSTM1), rGSTM2, rGSTM3 and rGST-Alpha. Molecular masses of rGSTM2, rGSTM3 and rGST-Alpha from liver and testis sources were similar, unlike STF-GSTM1, which was larger by 325 Da than its liver counterpart. Peptide digest analysis profiles on reverse-phase HPLC between liver and STF isoforms were identical, and N-terminal sequences of selected peptides obtained by digestion of the various isoforms were closely similar. The above results confirmed close structural similarity between liver and STF-GST isoforms. Active synthesis and secretion of GSTs by the STs were evident from recovery of radiolabelled GST from the spent media of ST cultures. Analysis of secreted GST isoforms showed that GST-Alpha was not secreted by the STs in vitro, whereas there was an induction of GST-Pi secretion. Detection of immunostainable GST-Mu in Sertoli cells in vitro and during different stages of the seminiferous epithelium in vivo, coupled with the recovery of radiolabelled GST from Sertoli cell-culture media, provided evidence for Sertoli cells as secretors of GST. In addition, STF of ‘Sertoli cell only’ animals showed no change in the profile of GST isoform secretion, thereby confirming Sertoli cells as prime GST secretors. Non-recovery of [35S]methionine-labelled GSTs from germ cell culture supernatants, but their presence in germ cell lysates, confirm the ability of the germ cells to synthesize, but not to release, GSTs. Functionally, STF-GSTM1 appeared to serve as a steroid-binding protein by its ability to bind to testosterone and oestradiol, two important hormones in the ST that are essential for spermatogenesis, with binding constants of < 9.8×10-7 M for testosterone and 9×10-6 M for oestradiol respectively.


2012 ◽  
Vol 24 (1) ◽  
pp. 162
Author(s):  
J. R. Miles ◽  
C. N. Sargus ◽  
S. A. Plautz ◽  
J. L. Vallet ◽  
A. K. Pannier

Between Day 10 and 12 of gestation, the pig embryo elongates from a sphere to a long thin, filament. During this time, the embryo increases the production of oestrogen via an increase in steroidogenic transcripts, which is critical for maternal recognition of pregnancy. To date, attempts to elongate porcine embryos in vitro have been unsuccessful. Therefore, the objective of this study was to utilise alginate hydrogels to establish a culture system that promotes in vitro embryo elongation with a corresponding increase in steroidogenic transcripts and oestradiol production. In 3 replicate collections, White crossbred gilts (n = 15) were bred at Day 0 of the oestrous cycle. At Day 9 of gestation, reproductive tracts were collected and flushed with RPMI-1640 containing antibiotics. Embryos were recovered, grouped according to size and washed with RPMI-1640 containing antibiotics and 10% fetal bovine serum (FBS). Embryos were randomly assigned to be encapsulated using a double encapsulation technique (0.7% sodium alginate and 1.5% calcium chloride solution) or used as controls. Encapsulated and control embryos were cultured for 96 h in CO2 -pretreated RPMI-1640 containing antibiotics and 10% FBS at 38°C, 5% CO2 in air and 100% humidity. Every 24 h, the embryos were imaged and half of the media was replaced. The removed media was stored at –20°C and used to assess oestradiol levels by radioimmunoassay. At the end of culture, a subset of encapsulated and control embryos were snap frozen and used to assess the expression level of steroidogenic transcripts (STAR, CYP11 and CYP19) using quantitative PCR. All data were analysed using general linear model (GLM) procedures for ANOVA. Cell survival, assessed by blastocyst fragmentation and confirmed by live/dead staining in representative embryos, was greater (P = 0.01) for encapsulated embryos (60.1 ± 4.8%) compared with controls (33.3 ± 4.8%). Of encapsulated embryos, 27% had some morphological change (minor flattening and tubal formation) and 14% had significant morphological changes (considerable flattening and tubal formation elongating through the gel), consistent with in vivo embryo elongation. In contrast, the control embryos had no morphological changes observed and remained spherical during culture. The expression levels of STAR, CYP11 and CYP19 were significantly (P < 0.05) greater in encapsulated embryos compared with control embryos. Furthermore, a significant (P < 0.01) time-dependent increase in oestradiol levels in the culture media of encapsulated embryos was identified compared with controls and culture media alone. These results illustrate that cultured pig embryos encapsulated in alginate hydrogels undergo limited morphological changes with increased expression of steroidogenic transcripts and oestrogen production. †USDA is an equal opportunity provider and employer.


2019 ◽  
Vol 5 (1) ◽  
pp. eaau7314 ◽  
Author(s):  
Johan Vande Voorde ◽  
Tobias Ackermann ◽  
Nadja Pfetzer ◽  
David Sumpton ◽  
Gillian Mackay ◽  
...  

Currently available cell culture media may not reproduce the in vivo metabolic environment of tumors. To demonstrate this, we compared the effects of a new physiological medium, Plasmax, with commercial media. We prove that the disproportionate nutrient composition of commercial media imposes metabolic artifacts on cancer cells. Their supraphysiological concentrations of pyruvate stabilize hypoxia-inducible factor 1α in normoxia, thereby inducing a pseudohypoxic transcriptional program. In addition, their arginine concentrations reverse the urea cycle reaction catalyzed by argininosuccinate lyase, an effect not observed in vivo, and prevented by Plasmax in vitro. The capacity of cancer cells to form colonies in commercial media was impaired by lipid peroxidation and ferroptosis and was rescued by selenium present in Plasmax. Last, an untargeted metabolic comparison revealed that breast cancer spheroids grown in Plasmax approximate the metabolic profile of mammary tumors better. In conclusion, a physiological medium improves the metabolic fidelity and biological relevance of in vitro cancer models.


1984 ◽  
Vol 219 (3) ◽  
pp. 793-799 ◽  
Author(s):  
S O Kolset ◽  
R Seljelid ◽  
U Lindahl

Monocytes were isolated from human blood and cultured in vitro on plastic culture dishes or on fibronectin-coated dishes. After 5 days in vitro, the cells on plastic dishes displayed marked morphological changes compared with day 1, with an epithelioid appearance resembling that of foreign-body cells. This transition was inhibited in cells cultured on fibronectin-coated dishes. 35S-labelled polysaccharides were isolated from the culture media after 24h incubation periods with inorganic [35S]sulphate. The cells cultured for 5 days on a plastic substrate synthesized, and secreted into the medium, an oversulphated galactosaminoglycan previously shown to contain 4,6-di-O-sulphated N-acetylgalactosamine units [Kolset, Kjellén, Seljelid & Lindahl (1983) Biochem. J. 210, 661-667]. In contrast, 35S-labelled polysaccharide produced by cells cultured on plastic for 1 day only, or on fibronectin for either 1 or 5 days, contained only minor amounts of such disulphated sugar units. These findings indicate that the formation of oversulphated chondroitin sulphate is coupled to the conversion of monocytes into epithelioid cells. Furthermore, they suggest that the overall process is induced by contact with artificial substrates, and that it may be regarded as the equivalent of a foreign-body reaction in vivo.


2020 ◽  
Vol 174 (2) ◽  
pp. 168-177 ◽  
Author(s):  
Yu-Syuan Luo ◽  
Kyle C Ferguson ◽  
Ivan Rusyn ◽  
Weihsueh A Chiu

Abstract Determining the in vitro bioavailable concentration is a critical, yet unmet need to refine in vitro-to-in vivo extrapolation for unknown or variable composition, complex reaction product or biological material (UVCB) substances. UVCBs such as petroleum substances are commonly subjected to dimethyl sulfoxide (DMSO) extraction in order to retrieve the bioactive polycyclic aromatic compound (PAC) portion for in vitro testing. In addition to DMSO extraction, protein binding in cell culture media and dilution can all influence in vitro bioavailable concentrations of aliphatic and aromatic compounds in petroleum substances. However, these in vitro factors have not been fully characterized. In this study, we aimed to fill in these data gaps by characterizing the effects of these processes using both a defined mixture of analytical standards containing aliphatic and aromatic hydrocarbons, as well as 4 refined petroleum products as prototypical examples of UVCBs. Each substance was extracted with DMSO, and the protein binding in cell culture media was measured by using solid-phase microextraction. Semiquantitative analysis for aliphatic and aromatic compounds was achieved via gas chromatography-mass spectrometry. Our results showed that DMSO selectively extracted PACs from test substances, and that chemical profiles of PACs across molecular classes remained consistent after extraction. With respect to protein binding, chemical profiles were retained at a lower dilution (higher concentration), but a greater dilution factor (ie, lower concentration) resulted in higher protein binding in cell medium, which in turn altered the ultimate chemical profile of bioavailable PACs. Overall, this case study demonstrates that extraction procedures, protein binding in cell culture media, and dilution factors prior to in vitro testing can all contribute to determining the final bioavailable concentrations of bioactive constituents of UVCBs in vitro. Thus, in vitro-to-in vivo extrapolation for UVCBs may require greater attention to the concentration-dependent and compound-specific differences in recovery and bioavailability.


2021 ◽  
pp. 088391152110031
Author(s):  
Scott M Herting ◽  
Mary Beth B Monroe ◽  
Andrew C Weems ◽  
Sam T Briggs ◽  
Grace K Fletcher ◽  
...  

Implantable medical devices must undergo thorough evaluation to ensure safety and efficacy before use in humans. If a device is designed to degrade, it is critical to understand the rate of degradation and the degradation products that will be released. Oxidative degradation is typically modeled in vitro by immersing materials or devices in hydrogen peroxide, which can limit further analysis of degradation products in many cases. Here we demonstrate a novel approach for testing the cytocompatibility of degradation products for oxidatively-degradable biomaterials where the materials are exposed to hydrogen peroxide, and then catalase enzyme is used to convert the hydrogen peroxide to water and oxygen so that the resulting aqueous solution can be added to cell culture media. To validate our results, expected degradation products are also synthesized then added to cell culture media. We used these methods to evaluate the cytocompatibility of degradation products from an oxidatively-degradable shape memory polyurethane designed in our lab and found that the degradation of these polymers is unlikely to cause a cytotoxic response in vivo based on the guidance provided by ISO 10993-5. These methods may also be applicable to other biocompatibility tests such as tests for mutagenicity or systemic toxicity, and evaluations of cell proliferation, migration, or gene and protein expression.


Author(s):  
Amine Ourahmane ◽  
Xiaohong Cui ◽  
Li He ◽  
Dirk Dittmer ◽  
Mark Schleiss ◽  
...  

Propagation of human cytomegalovirus (CMV) in cultured cells results in genetic adaptations that confer improved growth in vitro and significant attenuation in vivo. Mutations in RL13 arise quickly during cell culture passage, while mutations in the UL128-131A locus emerge later during fibroblast passage and disrupt expression of a glycoprotein complex that is important for entry into epithelial and endothelial cells. As in vivo CMV replicates in the context of host antibodies, we reasoned that antibodies might mitigate the accumulation of adaptive mutations during cell culture passage. To test this, CMV in infant urine was used to infect replicate fibroblast cultures. One lineage was passaged in the absence of CMV-hyperimmuneglobulin (HIG) while the other was passaged with HIG in the culture medium. The former lost epithelial tropism and aquired mutations disrupting RL13 and UL131A expression, whereas the latter retained epithelial tropism and both gene loci remained intact after 22 passages. An epitheliotropic RL13+/ UL131A+ virus was isolated by limiting-dilution in the presence of HIG and expanded to produce a working stock sufficient to conduct cell tropism experiments. Thus, culture in the presence of antibodies may facilitate in vitro experiments using viruses that are genetically more authentic than has been previously possible.


2018 ◽  
Vol 9 (4) ◽  
pp. 63 ◽  
Author(s):  
Lukas Raddatz ◽  
Antonina Lavrentieva ◽  
Iliyana Pepelanova ◽  
Janina Bahnemann ◽  
Dominik Geier ◽  
...  

Three-dimensional (3D)-bioprinting enables scientists to mimic in vivo micro-environments and to perform in vitro cell experiments under more physiological conditions than is possible with conventional two-dimensional (2D) cell culture. Cell-laden biomaterials (bioinks) are precisely processed to bioengineer tissue three-dimensionally. One primarily used matrix material is sodium alginate. This natural biopolymer provides both fine mechanical properties when gelated and high biocompatibility. Commonly, alginate is 3D bioprinted using extrusion based devices. The gelation reaction is hereby induced by a CaCl2 solution in the building chamber after material extrusion. This established technique has two main disadvantages: (1) CaCl2 can have toxic effects on the cell-laden hydrogels by oxygen diffusion limitation and (2) good printing resolution in the CaCl2 solution is hard to achieve, since the solution needs to be removed afterwards and substituted by cell culture media. Here, we show an innovative approach of alginate bioprinting based on a CaCl2 nebulizer. The device provides CaCl2 mist to the building platform inducing the gelation. The necessary amount of CaCl2 could be decreased as compared to previous gelation strategies and limitation of oxygen transfer during bioprinting can be reduced. The device was manufactured using the MJP-3D printing technique. Subsequently, its digital blueprint (CAD file) can be modified and additive manufactured easily and mounted in various extrusion bioprinters. With our approach, a concept for a more gentle 3D Bioprinting method could be shown. We demonstrated that the concept of an ultrasound-based nebulizer for CaCl2 mist generation can be used for 3D bioprinting and that the mist-induced polymerization of alginate hydrogels of different concentrations is feasible. Furthermore, different cell-laden alginate concentrations could be used: Cell spheroids (mesenchymal stem cells) and single cells (mouse fibroblasts) were successfully 3D printed yielding viable cells and stable hydrogels after 24 h cultivation. We suggest our work to show a different and novel approach on alginate bioprinting, which could be useful in generating cell-laden hydrogel constructs for e.g., drug screening or (soft) tissue engineering applications.


Viruses ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 221 ◽  
Author(s):  
Amine Ourahmane ◽  
Xiaohong Cui ◽  
Li He ◽  
Meaghan Catron ◽  
Dirk Dittmer ◽  
...  

Propagation of human cytomegalovirus (CMV) in cultured cells results in genetic adaptations that confer improved growth in vitro and significant attenuation in vivo. Mutations in RL13 arise quickly, while mutations in the UL128-131A locus emerge later during fibroblast passage and disrupt formation of a glycoprotein complex that is important for entry into epithelial and endothelial cells. As CMV replicates in the context of host antibodies in vivo, we reasoned that antibodies might mitigate the accumulation of adaptive mutations during cell culture passage. To test this, CMV in infant urine was used to infect replicate fibroblast cultures. One lineage was passaged in the absence of CMV-hyperimmuneglobulin (HIG) while the other was passaged with HIG in the culture medium. The former lost epithelial tropism and acquired mutations disrupting RL13 and UL131A expression, whereas the latter retained epithelial tropism and both gene loci remained intact after 22 passages. Additional mutations resulting in single amino acid changes also occurred in UL100 encoding glycoprotein M, UL102 encoding a subunit of the helicase/primase complex, and UL122 encoding the Immediate Early 2 protein. An epitheliotropic RL13+/UL131A+ virus was isolated by limiting dilution in the presence of HIG and expanded to produce a working stock sufficient to conduct cell tropism experiments. Thus, production of virus stocks by culture in the presence of antibodies may facilitate in vitro experiments using viruses that are genetically more authentic than previously available.


2014 ◽  
Vol 26 (7) ◽  
pp. 943 ◽  
Author(s):  
Catherine N. Sargus-Patino ◽  
Elane C. Wright ◽  
Sarah A. Plautz ◽  
Jeremy R. Miles ◽  
Jeff L. Vallet ◽  
...  

Between Days 10 and 12 of gestation, porcine embryos undergo a dramatic morphological change, known as elongation, with a corresponding increase in oestrogen production that triggers maternal recognition of pregnancy. Elongation deficiencies contribute to embryonic loss, but exact mechanisms of elongation are poorly understood due to the lack of an effective in vitro culture system. Our objective was to use alginate hydrogels as three-dimensional scaffolds that can mechanically support the in vitro development of preimplantation porcine embryos. White cross-bred gilts were bred at oestrus (Day 0) to Duroc boars and embryos were recovered on Days 9, 10 or 11 of gestation. Spherical embryos were randomly assigned to be encapsulated within double-layered 0.7% alginate beads or remain as non-encapsulated controls (ENC and CONT treatment groups, respectively) and were cultured for 96 h. Every 24 h, half the medium was replaced with fresh medium and an image of each embryo was recorded. At the termination of culture, embryo images were used to assess morphological changes and cell survival. 17β-Oestradiol levels were measured in the removed media by radioimmunoassay. Real-time polymerase chain reaction was used to analyse steroidogenic transcript expression at 96 h in ENC and CONT embryos, as well as in vivo-developed control embryos (i.e. spherical, ovoid and tubular). Although no differences in cell survival were observed, 32% (P < 0.001) of the surviving ENC embryos underwent morphological changes characterised by tubal formation with subsequent flattening, whereas none of the CONT embryos exhibited morphological changes. Expression of steroidogenic transcripts STAR, CYP11A1 and CYP19A1 was greater (P < 0.07) in ENC embryos with morphological changes (ENC+) compared with CONT embryos and ENC embryos with no morphological changes (ENC–), and was more similar to expression of later-stage in vivo-developed controls. Furthermore, a time-dependent increase (P < 0.001) in 17β-oestradiol was observed in culture media from ENC+ compared with ENC– and CONT embryos. These results illustrate that preimplantation pig embryos encapsulated in alginate hydrogels can undergo morphological changes with increased expression of steroidogenic transcripts and oestrogen production, consistent with in vivo-developed embryos. This alginate culture system can serve as a tool for evaluating specific mechanisms of embryo elongation that could be targeted to improve pregnancy outcomes.


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