Identification of valid endogenous control genes for determining gene expression in C6 glioma cell line treated with conditioned medium from adipose-derived stem cell

Oxidative Stress Effects of Multiple Pollutants in an Indoor Environment on Human Bronchial Epithelial Cells

Benzene, toluene, and xylene (denoted as BTX) are normally used in coatings, sealants, curing agents and other home decoration products, which can cause harm to human health. However, traditional studies mostly focus on the toxicity evaluation of a single pollution source, and little attention has been paid to the toxicity reports of multiple pollutants in a complex system. To evaluate the impact of indoor BTX on human health at the cellular level, the oxidative stress effect of BTX on human bronchial epithelial cells was assessed, including cell cytotoxicity, intracellular ROS, cell mitochondrial membrane potential, cell apoptosis, and CYP2E1 expression. The concentrations of BTX introduced into the human bronchial epithelial cell culture medium were determined based on both the tested distribution in 143 newly decorated rooms and the limited concentrations in the indoor air quality (denoted as IAQ) standards. Our study showed that the concentration in line with the standard limit may still pose a serious risk to health. The cellular biology effect studies of BTX showed that BTX, even at concentrations lower than the national standard limit, can still induce observable oxidative stress effects which warrant attention.

Epidermal melanocytes metabolize extracellular nucleotides by purinergic enzymes

The human epidermal melanocyte (hEM) are melanin-producing cells that provide skin pigmentation and protection against ultraviolet radiation. Although purinergic signaling is involved in skin biology and pathology, the presence of NTPDase members, as well as the rate of nucleotides degradation by melanocytes were not described yet. Therefore, in this study, we analyzed the expression of ectonucleotidases in hEM derived from discarded foreskin of male patients. The expression of purinergic enzymes was confirmed by mRNA and flow cytometry. Among the ectonucleotidases, ectonucleoside triphosphate diphosphohydrolase1 (NTPDase1) and ecto-5´-nucleotidase were the ectoenzymes with higher expressions. The hydrolysis rate for ATP, ADP, and AMP was low in comparison to other primary cells already investigated. The amount of ATP in the culture medium was increased after a scratch wound and decreased to basal levels in 48 h, while the NTPDase1 and P2X7 expressions increased. Therefore, it is possible to suggest that after cell injury, the ATP released by hEM into the extracellular space will be hydrolyzed by ectonucleotidases as the NTPDase1 that will control the levels of nucleotides in the skin micro-environment.

Effects of aerobic and resistance exercise training associated with carnosine precursor supplementation on maximal strength and V̇O2max in rats with heart failure

BACKGROUND

Combined exercise training (CET) has been associated with positive responses in the clinical status of patients with heart failure (HF). Other nonpharmacological tools, such as amino acid supplementation, may further enhance its adaptation. The aim was to test whether CET associated with supplementing carnosine precursors could present better responses in the functional capacity and biochemical variables of rats with HF.

METHODS

Twenty-one male Wistar rats were subjected to myocardial infarction and allocated to three groups: sedentary (SED, n = 7), CET supplemented with placebo (CETP, n = 7), and CET with HF supplemented with β-alanine and L-histidine (CETS, n = 7). The trained animals were submitted to a strength protocol three times per week. Aerobic training was conducted twice per week. The supplemented group received β-alanine and L-histidine orally (250 mg/kg per day).

RESULTS

Maximum oxygen uptake, running distance, time to exhaustion and maximum strength were higher in the CET-P group than that in the SED group and even higher in the CET-S group than that in the CET-P group (P < 0.01). CET-S showed lower oxidative stress and inflammation markers and higher heat shock protein 72 kDa content and mRNA expression for calcium transporters in the skeletal muscle compared to SED.

CONCLUSION

CET together with β-alanine and L-histidine supplementation in rats with HF can elicit adaptations in both maximum oxygen uptake, running distance, time to exhaustion, maximum strength, oxidative stress, inflammation and mRNA expression. Carnosine may influence beneficial adjustments in the cell stress response in the skeletal muscle and upregulate the mRNA expression of calcium transporters.

Down-regulation of circ-PTN suppresses cell proliferation, invasion and glycolysis in glioma by regulating miR-432-5p/RAB10 axis

BACKGROUND

Circular RNAs (circRNAs) are related to the carcinogenesis of cancers, including glioma. However, the role and mechanism of circRNA pleiotrophin (circ-PTN) remain largely unknown.

METHODS

Glioma tissues (n = 30) and normal tissues were obtained. Glioma cell lines LN229 and A172 were cultured for experiments in vitro. circ-PTN, microRNA-432-5p (miR-432-5p) and Ras-related protein Rab-10 (RAB10) levels were examined via quantitative reverse transcription polymerase chain reaction or western blot. Cell proliferation, invasion and glycolysis were examined via 3-(4, 5-Dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide, colony formation analysis, transwell invasion analysis, specific glucose, lactate or adenosine triphosphate assay kit and western blot. The relationship of miR-432-5p and circ-PTN or RAB10 was analyzed via dual-luciferase reporter analysis. The effect of circ-PTN on glioma development in vivo was explored by a murine xenograft model.

RESULTS

circ-PTN expression was enhanced and miR-432-5p abundance was reduced in glioma tissues and cells. circ-PTN silence suppressed cell proliferation, invasion and glycolysis. circ-PTN regulated glioma development by directly sponging miR-432-5p. RAB10 was a target of miR-432-5p and miR-432-5p inhibited cell proliferation, invasion and glycolysis by targeting RAB10. circ-PTN could modulate RAB10 expression via miR-432-5p. circ-PTN knockdown reduced glioma cell xenograft tumor growth in vivo.

CONCLUSION

circ-PTN knockdown repressed cell proliferation, invasion and glycolysis in glioma via modulating miR-432-5p and RAB10.

Normalization in Human Glioma Tissue

For tissues obtained from glioma samples with/without nonneoplastic brain there is no consensus for universal reference gene but there are some potential genes that might have good stability, under certain conditions. Considering all points described in this work, the care with tissue collection, until gene amplification, directly impacts on the reliable characterization of its mRNA levels. Moreover, it is clear the importance of selecting the most appropriate reference genes for each experimental situation, to allow the accurate normalization of target genes, especially for genes that are subtly regulated.

Identification of Suitable Reference Genes for Quantitative Gene Expression Analysis in Innervated and Denervated Adipose Tissue from Cafeteria Diet-Fed Rats

Our previous studies show that cafeteria diet increases body adiposity, plasma insulin levels, and sympathetic activity to brown adipose tissue (BAT) and white adipose tissue (WAT) of Wistar rats, leading to rapid and progressive changes in the metabolic profile. The identification of suitable reference genes that are not affected by the experimental conditions is a critical step in accurate normalization of the reverse transcription quantitative real-time PCR (qRT-PCR), a commonly used assay to elucidate changes in the gene expression profile. In the present study, the effects of the cafeteria diet and sympathetic innervation on the gene expression of adrenoceptor beta 3 (Adrb3) from BAT and WAT were assessed using one of the most stable and one of the least stable genes as normalizers. Rats were fed the cafeteria diet and on the 17th day, interscapular BAT or retroperitoneal WAT was denervated and, 7 days after surgery, the contralateral innervated tissue was used as control. Ten reference genes were evaluated (18S, B2m, Actb, CypA, Gapdh, Hprt1, Rpl32, Tbp, Ubc, and Ywhaz) and ranked according to their stability using the following algorithms: geNorm, NormFinder, BestKeeper, and comparative delta threshold cycle (ΔC _t ) method. According to the algorithms employed, the normalization of Adrb3 expression by the least stable genes produced opposite results compared with the most stable genes and literature data. In cafeteria and control diet-fed rats, the three most stable genes were Hprt1, Tbp, and Rpl32 for interscapular BAT and Tbp, B2m, and Hprt1 for retroperitoneal WAT, while the least stable genes were 18S, Actb, and Gapdh for both tissues.

Selection and Validation of Reference Genes for RT-PCR Expression Analysis of Candidate Genes Involved in Morphine-Induced Conditioned Place Preference Mice

The expression of reference genes should be constitutively stable under the experimental conditions, so determining stable reference genes is critical for obtaining reliable results in gene expression studies. Morphine addiction persistently influences neurotransmitters and signal transduction systems, which may negatively alter behavioral responses at the cellular levels and interfere the expression of reference genes. In order to research morphine dependence, animal models are commonly used in physiology, pathology, and therapeutics field since human trials have many limitations. Therefore, it is necessary to select stable reference genes in standardized animal model. The objective of this study is to find out a set of optimal reference genes to standardize the gene expression of morphine-induced conditioned place preference (CPP) mice. During the process, eight reference genes were chosen. Then, the stability of their expression in two different brain tissues (Caudate Putamen and Hippocampus) was tested in two developmental stages (puberty and adult) under two treatments (physiological saline as control and morphine). Based on two algorithm-based methods (geNorm and NormFinder), which can rank and assess the stability of expression of eight reference genes, thereby quantifying the transcriptional levels of these genes by high sensitive, specific, and accurate real-time quantitative reverse transcription PCR (RT-qPCR) assays.

Mesenchymal Stromal Cells-Derived β2-Microglobulin Promotes Epithelial-Mesenchymal Transition of Esophageal Squamous Cell Carcinoma Cells

Mesenchymal stromal cells (MSCs) have been considered as one of the pivotal type of cells composing the tumor microenvironment. Although contact-dependent mechanisms and paracrine factors are thought to collaborate in governing the MSCs-based effects on tumors progression, the underlying mechanisms remain largely unknown. In particular, the involvement of MSCs-derived cytokines in the epithelial-mesenchymal transition (EMT) of esophageal squamous cell carcinoma (ESCC) has not been clarified. In this study, we observed that β2-Microglobulin (B2M) is highly expressed in MSCs but scarcely in ESCC cells. Based on the previously described EMT promoting effect of B2M, we investigated the in vitro effect of MSCs-derived B2M on the EMT of ESCC cells, and discovered its subsequent enhancing effects on cell mobility and tumor-initiation. Further xenograft transplantation experiments confirmed the in vivo induction of tumor-initiation by MSCs-derived B2M. Noteworthy, we showed that the B2M expression positively correlated with poor prognosis. The fact that B2M is primarily expressed by the stroma of the ESCC tissue strengthens our hypothesis that in ESCC, MSCs-derived B2M promotes tumor-initiation and invasion via enhancing EMT, resulting in an adverse prognosis for the patients. Our results will be valuable for the prediction of the development and treatment of ESCC.

Cervical cancer stem-like cells: systematic review and identification of reference genes for gene expression

Cervical cancer is the fourth most common cancer affecting women worldwide. Among many factors, the presence of cancer stem cells, a subpopulation of cells inside the tumor, has been associated with a worse prognosis. Considering the importance of gene expression studies to understand the biology of cervical cancer stem cells (CCSC), this work identifies stable reference genes for cervical cancer cell lines SiHa, HeLa, and ME180 as well as their respective cancer stem-like cells. A literature review was performed to identify validated reference genes currently used to normalize RT-qPCR data in cervical cancer cell lines. Then, cell lines were cultured in regular monolayer or in a condition that favors tumor sphere formation. RT-qPCR was performed using five reference genes: ACTB, B2M, GAPDH, HPRT1, and TBP. Stability was assessed to validate the selected genes as suitable reference genes. The evaluation validated B2M, GAPDH, HPRT1, and TBP in these experimental conditions. Among them, GAPDH and TBP presented the lowest variability according to the analysis by Normfinder, Bestkeeper, and ΔCq methods, being therefore the most adequate genes to normalize the combination of all samples. These results suggest that B2M, GAPDH, HPRT1, and TBP are suitable reference genes to normalize RT-qPCR data of established cervical cancer cell lines SiHa, HeLa, and ME180 as well as their derived cancer stem-like cells. Indeed, GAPDH and TBP seem to be the most convenient choices for studying gene expression in these cells in monolayers or spheres.

Selection of Suitable Reference Genes for Quantitative Real-Time PCR Normalization in Human Stem Cell Research

Quantitative real-time polymerase chain reaction (qRT-PCR) is a widely utilized method for evaluating the gene expressions in stem cell research. This method enables researchers to obtain fast and precise results, but the accuracy of the data depends on certain factors, such as those associated with biological sample preparation and PCR efficiency. In order to achieve accurate and reliable results, it is of utmost importance to designate the reference genes, the expressions of which are suitable to all kinds of experimental conditions. Hence it is vital to normalize the qRT-PCR data by using the reference genes. In recent years, it has been found that the expression levels of reference genes widely used in stem cell research present a substantial amount of variation and are not necessarily suitable for normalization. This chapter at hand stresses the significance of selecting suitable reference genes from the point view of human stem cell research.

Extracellular Nucleotide Hydrolysis in Dermal and Limbal Mesenchymal Stem Cells: A Source of Adenosine Production

Human Limbal (L-MSCs) and Dermal Mesenchymal Stem Cell (D-MSCs) possess many properties that increase their therapeutic potential in ophthalmology and dermatology. It is known that purinergic signaling plays a role in many aspects of mesenchymal stem cells physiology. They release and respond to purinergic ligands, altering proliferation, migration, differentiation, and apoptosis. Therefore, more information on these processes would be crucial for establishing future clinical applications using their differentiation potential, but without undesirable side effects. This study evaluated and compared the expression of ecto-nucleotidases, the enzymatic activity of degradation of extracellular nucleotides and the metabolism of extracellular ATP in D-MSCs and L-MSCs, isolated from discard tissues of human skin and sclerocorneal rims. The D-MSCs and L-MSCs showed a differentiation potential into osteogenic, adipogenic, and chondrogenic lineages and the expression of markers CD105⁺ , CD44⁺ , CD14^- , CD34^- , CD45^- , as expected. Both cells hydrolyzed low levels of extracellular ATP and high levels of AMP, leading to adenosine accumulation that can regulate inflammation and tissue repair. These cells expressed mRNA for ENTPD1, 2, 3, 5 and 6, and CD73 that corresponded to the observed enzymatic activities. Thus, considering the degradation of ATP and adenosine production, limbal MSCs are very similar to dermal MSCs, indicating that from the aspect of extracellular nucleotide metabolism L-MSCs are very similar to the characterized D-MSCs. J. Cell. Biochem. 118: 2430-2442, 2017. © 2017 Wiley Periodicals, Inc.