Establishment and characterization of a recurrent malignant peripheral nerve sheath tumor cell line: RsNF

Malignant peripheral nerve sheath tumor (MPNST) is a highly aggressive and recurrent soft tissue sarcoma. It most commonly occurs secondary to neurofibromatosis type I, and it has a 5-year survival rate of only 8-13%. To better study the tumor heterogeneity of MPNST and to develop diverse treatment options, more tumor-derived cell lines are needed to obtain richer biological information. Here, we established a primary cell line of relapsed MPNST RsNF cells derived from a patient diagnosed with NF1 and detected the presence of NF1 mutations and SUZ12 somatic mutations through whole-exome sequencing(WES). Through tumor molecular marker targeted sequencing and single-cell transcriptome sequencing, it was found that chromosome 7 copy number variation (CNV) was gained in this cell line, and ZNF804B, EGFR, etc., were overexpressed on chromosome 7. Therefore, RsNF cells can be used as a useful tool in NF1-associated MPNST genomic amplification studies and to develop new therapeutic strategies.

Glial cell proteome using targeted quantitative methods for potential multi-diagnostic biomarkers

Glioblastoma is one of the most malignant primary brain cancer. Despite surgical resection with modern technology followed by chemo-radiation therapy with temozolomide, resistance to the treatment and recurrence is common due to its aggressive and infiltrating nature of the tumor with high proliferation index. The median survival time of the patients with glioblastomas is less than 15 months. Till now there has been no report of molecular target specific for glioblastomas. Early diagnosis and development of molecular target specific for glioblastomas are essential for longer survival of the patients with glioblastomas. Development of biomarkers specific for glioblastomas is most important for early diagnosis, estimation of the prognosis, and molecular target therapy of glioblastomas. To that end, in this study, we have conducted a comprehensive proteome study using primary cells and tissues from patients with glioblastoma. In the discovery stage, we have identified 7429 glioblastoma-specific proteins, where 476 proteins were quantitated using Tandem Mass Tag (TMT) method; 228 and 248 proteins showed up and down-regulated pattern, respectively. In the validation stage (20 selected target proteins), we developed quantitative targeted method (MRM: Multiple reaction monitoring) using stable isotope standards (SIS) peptide. In this study, five proteins (CCT3, PCMT1, TKT, TOMM34, UBA1) showed the significantly different protein levels (t-test: p value ≤ 0.05, AUC ≥ 0.7) between control and cancer groups and the result of multiplex assay using logistic regression showed the 5-marker panel showed better sensitivity (0.80 and 0.90), specificity (0.92 and 1.00), error rate (10 and 2%), and AUC value (0.94 and 0.98) than the best single marker (TOMM34) in primary cells and tissues, respectively. Although we acknowledge that the model requires further validation in a large sample size, the 5 protein marker panel can be used as baseline data for the discovery of novel biomarkers of the glioblastoma.

A newly improved method of primary cell culture: Tissue block with continuous adhesion subculture in skin fibroblast

BACKGROUND

Fibroblasts (FBs) have been widely used as a typical in vitro cell model for investigating the biological processes and cell pathophysiological mechanisms. However, FBs are prone to senescence in cell culture process after several passages. Thus, a new approach to cell culture is quite required to enhance the viability of cells.

OBJECTIVE

To explore a novel method of cell culture based on skin FBs.

METHODS

Dermal tissue blocks were obtained from BALB/c neonatal mice and randomly divided into experimental group and control group. The experimental group received the newly improved culture method, namely, continuous adherence subculture of tissue block (CASTB) method; while the traditional subculture method was applied in the control group. Cells at 1st, 5th and 10th passages were collected and identified by using histological/immunohistochemical and western blot analysis. Cellular viability, proliferation, senescence and apoptosis were analyzed through application of cell growth curve, CCK-8 assay, Ki67 assay, PCNA protein analysis, β-galactosidase staining, flow cytometry and western blot analysis.

RESULTS

Cells under two culture patterns exhibited spindle/irregular shape and vimentin positive expression. With the increase of passage times, the cellular growth rate in the control group gradually decreased, but no alterations emerged from the experimental group. CASTB method remarkably promoted cell growth and proliferation. Moreover, a greatly lower apoptosis and senescence tendency appeared in the experimental group than the control group with passages increasing.

CONCLUSION

The method of CASTB is superior to traditional subculture, offering a large number of primary FBs with higher efficiency and success rate and being worth of further popularization and application.

Surface migration of Pb(II) from water and soil using an aerogel/graphite felt primary cell system

To develop a zero energy consumption electrokinetic remediation method of Pb(II) in water and soil, a primary cell system was constructed via synergistic effects of the electromigration, ion exchange, precipitation and hydrogen bond. The primary cell system used cathode of calcium alginate aerogel/graphite felt (CAA/GF) and another piece of CAA/GF was placed on the top of the water and soil. Thus the electric field in the system could drive positively charged Pb(II) towards the top of and thus Pb(II) was surface migrated, promoting removal of Pb(II). This system achieved Pb(II) removal efficiency of 97.8% and maximum power density of 32.1 mW m^-2. Additionally, the CAA/GF presented a good reusability. This work provides a promising and facile method to remove heavy metals from water and soil, which might have a huge application prospect.

Reprogramming of Primary Human Cells to Induced Pluripotent Stem Cells Using Sendai Virus

Induced pluripotent stem (iPS) cells are important tools for studying differentiation and for use in patient-specific disease modeling. We present a detailed method for the reprogramming of primary human fibroblasts to induced pluripotent stem cells using Sendai virus. These procedures allow for the efficient generation of multiple high-quality feeder-independent iPS cell lines for a given human fibroblast line. The iPS cell lines generated by this protocol can be used in a variety of differentiation and gene expression studies, as well as in genetic manipulations.

In Vitro Culture of Cryptosporidium parvum Using Stem Cell-Derived Intestinal Epithelial Monolayers

Cryptosporidium parvum has a complex life cycle consisting of asexual and sexual phases that culminate in oocyst formation in vivo. The most widely used cell culture platforms to study C. parvum only support a few days of growth and do not allow the parasite to proceed past the sexual stages to complete oocyst formation. Additionally, these cell culture platforms are mostly adenocarcinoma cell lines, which do not adequately model the parasite's natural environment in the small intestine. We describe here a method to create primary intestinal epithelial cell monolayers that support long-term C. parvum growth. Monolayers were derived from mouse intestinal stem cells grown as spheroids and plated onto transwells, allowing for separate apical and basolateral compartments. In the apical chamber, the cell growth medium was removed to create an "air-liquid interface" that enhanced host cell differentiation and supported long-term C. parvum growth. The use of primary intestinal cells to grow C. parvum in vitro will be a valuable tool for studying host-parasite interactions using a convenient in vitro model that more closely resembles the natural niche in the intestine.

Towards the development of standardised sea turtle primary cell cultures for toxicity testing

Chemical contaminants are known to accumulate in marine megafauna globally, but little is known about how this impacts animal health. In vitro assays offer an ethical, reproducible and cost-effective alternative to live animal toxicity testing on large, long-lived or threatened species, such as sea turtles. However, using a cell culture from a single animal raise the question of whether the toxicity observed adequately represents the toxicity in that species. This study examined variation in the cytotoxic response of primary skin fibroblasts established from seven green (Chelonia mydas) and five loggerhead (Caretta caretta) sea turtles. Cell viability using resazurin dye was examined in response to exposure to five contaminants. The variation in cytotoxicity was generally low (within a factor of five) for both independent analyses of the same cell culture, and cell cultures from different individuals. This low within and between cell culture variation indicates that primary sea turtle cell cultures can provide a suitable approach to understanding toxicity in sea turtles. In addition, green and loggerhead turtle cells showed similar toxicity to the compounds tested, indicating that only subtle differences in chemical sensitivity may exist between sea turtle species. This study provides a framework for using species-specific cell cultures in future toxicological studies on sea turtles. Although in vivo studies are the gold standard for toxicological studies and species-specific risk assessments, the development of in vitro tools can provide important information when in vivo studies are not possible or practical. For large, endangered species such as sea turtles that are exposed to, and accumulate, a large number of contaminants, using validated cell cultures may facilitate the rapid assessment of chemical risk to these animals.

The Improvement and Application of Lentivirus-Mediated Gene Transfer and Expression System in Penaeid Shrimp Cells

This study first reported the improvement and application of lentivirus-mediated gene transfer and expression system in shrimp cells. After modified by the inclusion of two envelope proteins (VP19 and VP28) of shrimp white spot syndrome virus (WSSV) into the envelope of the packaged lentivirus, and insertion of a truncated promoter of immediate-early gene 1 (Pie1-504) of shrimp WSSV virus into the lentiviral reporter plasmid, the second-generation lentiviral expression system (pLVX-PEF1α-IRES-mCherry, psPAX2, and PMD2.G) was found to behave better in the mitosis-arrested shrimp cells than the similarly modified retrovirus expression system did. Results from the insect sf9 cells indicated that the inclusion of VP19 and VP28 into the envelope of packaged lentiviruses could significantly improve the tropism or infectivity of the modified lentiviruses to insect cells in a cumulative way. Notably, the VP28 contributed about 86% of the total increase of the tropism. In the shrimp primary lymphoid cells infected by modified lentivirus IV with both VP19 and VP28 included, the infection efficiency was up to 11% (non-confocal) and 19% (confocal) and no background fluorescent signal was observed. However, background fluorescent signal was observed in the shrimp primary Oka organ cells although only under a confocal microscope. In the lentivirus IV-infected Oka organ cells, the actual infection efficiencies were calculated up to 8% (non-confocal) and 19% (confocal), significantly higher than those of commercial intact lentivirus I of 0 (non-confocal) and 3% (confocal). The insertion of WSSV promoter (Pie1-504) had interrupted the effective expression of reporter plasmid encoding lentiviral construct of pLVX-PEF1α-Pie1-504-IRES-mCherry in the HEK293T cells, but markedly increased its efficiencies up to 14% (non-confocal) and 26% (confocal) in the Oka organ cells. This improved lentivirus expression system will provide us a useful tool for efficient gene transfer and expression in shrimp cells.

Keratin biomaterials augment anti-inflammatory macrophage phenotype in vitro

Tissue regeneration following injury is mediated by macrophage recruitment and differentiation in response to environmental signals. In general, macrophages adopt either a classically M1 (M[IFN-γ, LPS]) or alternatively activated M2 (M[IL-4, IL-13] or M[IL-10]) phenotype. Recent studies have highlighted the importance of alternatively activated macrophages in tissue remodeling and repair as well as the contribution of an imbalance of classically and alternatively activated macrophages to tissue degeneration and disease progression. Keratin biomaterials have recently demonstrated their ability to promote alternatively activated macrophage polarization in an in vitro model using a monocytic cell line. In the present study, the ability of extracted human hair keratins to influence alternative activation of human primary monocytes in vitro is assessed by evaluating changes in surface receptor expression, inflammatory cytokine secretion, and phagocytic activity. The impact of keratin molecular weight fractionation on these outcomes was also investigated. High and low molecular weight fractions of the oxidized form of extractable human hair keratins - referred to as keratose (KOS^H and KOS^P, respectively) - were characterized by size exclusion chromatography, mass spectrometry, and Western blot. Primary macrophages underwent traditional differentiation to the M[IFN-γ, LPS], M[IL-4, IL-13], or M[IL-10]) phenotypes or were plated on different molecular weight keratin coatings (KOS^H and KOS^P). Macrophages plated on keratin and analyzed via flow cytometry yielded the largest CD163⁺ cell populations and CD163 mean fluorescence intensities. Cells in the KOS^P group were significantly more phagocytic than all other cell types at the 1.5 and 3 h time points and exhibited behavior and a cytokine production profile most similar to the M[IL-10] treated group. These findings may have important implications for understanding and evaluating the ability of keratin biomaterials to influence inflammation and tissue regeneration in disease and injury models.

STATEMENT OF SIGNIFICANCE

Biomaterials made from human hair keratins have previously been shown to elicit anti-inflammatory responses from naïve macrophages and polarize them toward an M2 phenotype. In this work we show for the first time that primary human cells respond similarly, that it is the M2c phenotype that predominates, that a sub-fraction of hydrolyzed keratin peptides are most likely responsible for the response, and that immobilization of the keratin peptides to a surface is required. Keratin biomaterials have been used to regenerate several tissues such as skin, muscle, bone, nerve, and cornea, in vitro and in animal studies. Our current findings will help guide the development of keratin-based biomaterials that seek to direct responses toward regenerative outcomes by attenuating inflammation.

Application of NMR Spectroscopy in the Assessment of Radiation Dose in Human Primary Cells

We employed the primary cell model system as a first step toward establishing a method to assess the influence of ionizing radiation by using a combination of common and abundant metabolites. We applied X-ray irradiation amounts of 0, 1, and 5 Gy to the cells that were harvested 24, 48, or 72 h later, and profiled metabolites by 2D-NMR spectroscopy to sort out candidate molecules that could be used to distinguish the samples under different irradiation conditions. We traced metabolites stemming from the input ¹³C-glucose, identified twelve of them from the cell extracts, and applied statistical analysis to find out that all the metabolites, including glycine, alanine, and gluatamic acid, increased upon irradiation. The combinatorial use of the selected metabolites showed promising results where the product of signal intensities of alanine and lactate could differentiate samples according to the dose of X-ray irradiation. We hope that this work can form a base for treating radiation-poisoned patients in the future.

The human secretome atlas initiative: implications in health and disease conditions

Proteomic analysis of human body fluids is highly challenging, therefore many researchers are redirecting efforts toward secretome profiling. The goal is to define potential biomarkers and therapeutic targets in the secretome that can be traced back in accessible human body fluids. However, currently there is a lack of secretome profiles of normal human primary cells making it difficult to assess the biological meaning of current findings. In this study we sought to establish secretome profiles of human primary cells obtained from healthy donors with the goal of building a human secretome atlas. Such an atlas can be used as a reference for discovery of potential disease associated biomarkers and eventually novel therapeutic targets. As a preliminary study, secretome profiles were established for six different types of human primary cell cultures and checked for overlaps with the three major human body fluids including plasma, cerebrospinal fluid and urine. About 67% of the 1054 identified proteins in the secretome of these primary cells occurred in at least one body fluid. Furthermore, comparison of the secretome profiles of two human glioblastoma cell lines to this new human secretome atlas enabled unambiguous identification of potential brain tumor biomarkers. These biomarkers can be easily monitored in different body fluids using stable isotope labeled standard proteins. The long term goal of this study is to establish a comprehensive online human secretome atlas for future use as a reference for any disease related secretome study. This article is part of a Special Issue entitled: An Updated Secretome.