The Effect of High Temperature on Viability, Proliferation, Apoptosis and Anti-oxidant Status of Chicken Embryonic Fibroblast Cells

Effect of elevated temperature and hydrocortisone addition on the proliferation of fibroblasts

Hyperthermia along with hydrocortisone (HC) are proven teratogens that can negatively influence embryo development during early pregnancy. Proliferation of cells is one of the main developmental processes during the early embryogenesis. This study was focused on testing the effect of elevated temperature and HC addition on proliferation of cells in in vitro cultures. The V79-4 cell line was treated with HC and cultured in vitro at 37 °C or 39 °C, respectively. To reveal the effect of both factors, the proliferation of cells cultured under different conditions was evaluated using various approaches (colony formation assay, generation of growth curves, computation of doubling times, and mitotic index estimation). Our results indicate that a short-term exposure to elevated temperature slightly stimulates and a long-term exposure suppresses cell proliferation. However, HC (0.1 mg/ml) acts as a stimulator of cell proliferation. Interestingly, the interaction of HC and long-term elevated temperature (39 °C) exposure results in at least partial compensation of the negative impact of elevated temperature by HC addition and in higher proliferation if compared with cells cultured at 39 °C without addition of HC.

Editing of HSF-1 and Na/K-ATPase α1 subunit by CRISPR/Cas9 reduces thermal tolerance of bovine skin fibroblasts to heat shock in vitro

A follow-up to our previous findings, the present study was planned to evaluate the role of Na/K-ATPase alpha1-subunit (ATP1A1) gene in heat shock tolerance. The primary fibroblast culture was established using ear pinna tissue samples of Sahiwal cattle (Bos indicus). The knockout cell lines of Na/K-ATP1A1 and HSF-1 (heat shock factor-1, as a positive control) genes were developed by CRISPR/Cas9 method and the gene-editing was confirmed by the genomic cleavage detection assay. The two knockout cell lines (ATP1A1 and HSF-1) and wild-type fibroblasts were exposed to heat shock at 42 °C in vitro and different cellular parameters viz., apoptosis, proliferation, mitochondrial membrane potential (ΔΨm), oxidative stress, along with expression pattern of heat-responsive genes were studied. The results showed that in vitro heat shock given to knockout fibroblast cells of both ATP1A1 and HSF-1 genes resulted in decreased cell viability, while increasing the apoptosis rate, membrane depolarization, and ROS levels. However, the overall impact was more in HSF-1 knockout cells as compared to ATP1A1 knockout cells. Taken together, these results indicated that the ATP1A1 gene plays a critical role as HSF-1 under heat stress and helps cells to cope with heat shock.

Long-Term In Vitro Maintenance of Piglet Testicular Tissue: Effects of Tissue Fragment Size, Preparation Method, and Serum Source

Long-term culture of testicular tissue has important applications, including the preservation of fertility potential of prepubertal boys undergoing gonadotoxic cancer treatment. This study was designed to define optimal conditions for the long-term culture of neonatal porcine testicular tissue as an animal model for preadolescent individuals. Testes from 1 wk old donor piglets were used to examine the effects of tissue fragment size (~2, 4, 6, or 8 mg), preparation method (intact, semi-digested, or physically dispersed fragments), and serum source in the media (fetal bovine serum—FBS—or knockout serum replacement—KSR). Testicular fragments were examined weekly for 4 weeks for tissue integrity, seminiferous cord density and morphology, and gonocyte counts. Testicular tissue integrity was dependent on fragment size and preparation method, where the smallest size (2 mg, p < 0.05) and intact preparation method were advantageous (p < 0.05). Seminiferous cord density decreased over the culture period (p < 0.05). Although the relative number of gonocytes decreased over time for all sizes and methods (p < 0.01), smaller intact fragments (2 and 4 mg) had greater numbers of gonocytes (p < 0.05). Our findings suggest that intact or physically dispersed testicular fragments of the smallest size (2 mg) cultured in KSR-supplemented media could be effectively maintained in vitro for the duration of 4 weeks.

Virus-Mediated Inhibition of Apoptosis in the Context of EBV-Associated Diseases: Molecular Mechanisms and Therapeutic Perspectives

Epstein-Barr virus (EBV), the representative of the Herpesviridae family, is a pathogen extensively distributed in the human population. One of its most characteristic features is the capability to establish latent infection in the host. The infected cells serve as a sanctuary for the dormant virus, and therefore their desensitization to apoptotic stimuli is part of the viral strategy for long-term survival. For this reason, EBV encodes a set of anti-apoptotic products. They may increase the viability of infected cells and enhance their resistance to chemotherapy, thereby contributing to the development of EBV-associated diseases, including Burkitt’s lymphoma (BL), Hodgkin’s lymphoma (HL), gastric cancer (GC), nasopharyngeal carcinoma (NPC) and several other malignancies. In this paper, we have described the molecular mechanism of anti-apoptotic actions of a set of EBV proteins. Moreover, we have reviewed the pro-survival role of non-coding viral transcripts: EBV-encoded small RNAs (EBERs) and microRNAs (miRNAs), in EBV-carrying malignant cells. The influence of EBV on the expression, activity and/or intracellular distribution of B-cell lymphoma 2 (Bcl-2) protein family members, has been presented. Finally, we have also discussed therapeutic perspectives of targeting viral anti-apoptotic products or their molecular partners.

The lethal heat dose for 50% primary human fibroblast cell death is 48 °C

Understanding the effect of heat on skin cells is important for the prevention of burn injury. Knowledge of the heat dose required to kill cells can be used to study the cellular mechanisms involved in thermal injury cell death, to assist with the development of novel burn treatments. In this study, primary human skin dermal fibroblasts were exposed to temperatures from 37 to 54 °C for 1 h and the relative cell viability of heat-treated and control cells was assessed. Cell damage and viability were assessed by light microscopy, MTT assay and live/dead staining. The LD50 for 1 h of heat exposure was 48 °C for primary fibroblasts; and there was evidence that thermal damage to cells begins to occur at 43 °C. This study presents a reproducible method for examining the effect of heat on primary human cells grown in culture on a cellular level and can be used in the future to study the mechanisms behind heat-induced cell death, to inform burn injury prevention efforts and effective post-burn treatment.

Direct exposure to mild heat stress stimulates cell viability and heat shock protein expression in primary cultured broiler fibroblasts

Fibroblasts produce collagen which is mainly essential for repairing tissue damage and maintaining the structural integrity of tissues. However, studies have given scientific evidence about harmful effect of thermal manipulation in fibroblast. Therefore, the aim of this study was to determine the mild heat stress temperature which increased broiler fibroblast viability. The experiment was divided into two groups (37 °C and 41 °C), and each group was divided into five subgroups based on different incubation times (6 h, 12 h, 24 h, 48 h, and 72 h) with three replications. In experimental group (41 °C), fibroblast viability increased significantly in 12 h but decreased in 72 h compared with control (37 °C). At 41 °C, live cell increased significantly in 24 h and then declined in 48 h as well as 72 h than control. Moreover, the S phase lengthened in shorter incubation time of experimental group compared with control. Protein and mRNA (HSP70, HSP60, and HSP47) expressions were significantly higher at 41 °C compared with 37 °C, but at the end of the experiment, HSP expression level was higher in both groups. Finally, this study recommended 41 °C as a mild heat stress temperature for increasing broiler fibroblast viability.

Enthalpy thematic map interpolated with spline method for management of broiler chicken production

ABSTRACT Owing to the exponential growth of the human population and problems related to food supply, research focused on finding the most suitable approach to manage and geographically explore the environment using sustainable technologies stand out. The present study aims to produce a consistent interpolation of historical series of enthalpy (H) resulting in a thematic map of enthalpy, using the spline method as a kriging option in areas with few sampling points. The thematic map considers thermal comfort conditions to produce broiler chickens, that could be used as a management tool to reduce power consumption due to the cooling process of the facilities. It was verified that spline is an efficient method to create a suitable thematic maps representations of areas presenting a few sampled units. The geographical representation of enthalpy allowed the evaluation of the environments, concluding that the state of Mato Grosso do Sul, Brazil is inadequate for broiler chickens production without suitable thermal cooling systems. Evidence suggests introduction of aviculture in areas still unexplored, e.g., Chapadão do Sul and Sete Quedas.

Modulatory effect of heat stress on viability of primary cultured chicken satellite cells and expression of heat shock proteins ex vivo

Satellite cells promote muscle repairing and muscle growth. Thereby the intention of the present study was to investigate the beneficial effects of heat stress at different time intervals on chicken satellite cells' viability. Satellite cells were isolated from 1-day-old chicks and treated at two different temperatures (37 °C and 41 °C) for various time periods (6 h, 12 h, 24 h, 48 h, and 72 h). Both temperatures significantly increased cell viability after 24 h and 48 h. After 12 h, cell viability was significantly increased at 41 °C compared to 37 °C. However, more apoptotic cells were observed at end of the experiment of 41 °C compared to 37 °C. In addition, more live cells were found at early of experimental period at 41 °C than 37 °C. Additionally, protein and mRNA expression of HSP70, HP60 and HSP47 were significantly upregulated throughout the experimental period at temperature of 41 °C compared to those at 37 °C. These results indicate that cell viability and expression of heat stress related proteins/genes are induced by high temperature of 41 °C via heat stress pathway whereas activation of heat stress related proteins/genes are lower at 37 °C. Thus, 41 °C can trigger satellite cells' viability essential for better cell survival than 37 °C at early incubation time.

Effects of Acute Heat Stress on a Newly Established Chicken Hepatocyte-Nonparenchymal Cell Co-Culture Model

Heat stress is one of the most important issues in broiler flocks impairing animal health and productivity. On a cellular level, excess heat exposure can trigger heat shock response acting for the restoration of cell homeostasis by several mechanisms, such as affecting heat shock protein synthesis, redox homeostasis and pro-inflammatory cytokine production. The major aim of this study was to establish a novel avian hepatocyte-nonparenchymal cell co-culture as a model for investigating the cellular effects of heat stress and its interaction with inflammation in chicken liver. Cell fractions were isolated by differential centrifugation from a freshly perfused chicken liver, and hepatocyte mono-cultures as well as hepatocyte-nonparenchymal cell co-cultures (with cell ratio 6:1, hepatocytes to nonparenchymal cells, mimicking a milder hepatic inflammation) were prepared. Isolated and cultured cells were characterized by flow cytometry and immunocytochemistry applying hepatocyte- and macrophage-specific antibodies. Confluent cell cultures were exposed to 43 °C temperature for 1 or 2 h, while controls were cultured at 38.5 °C. The metabolic activity, LDH enzyme activity, reactive oxygen species (H₂O₂) production, extracellular concentration of heat shock protein 70 (HSP70), and that of the pro-inflammatory cytokines interleukin (IL-)6 and IL-8 were assessed. Shorter heat stress applied for 1 h could strongly influence liver cell function by significantly increasing catabolic metabolism and extracellular H₂O₂ release, and by significantly decreasing HSP70, IL-6, and IL-8 production on both cell culture models. However, all these alterations were restored after 2 h heat exposure, indicating a fast recovery of liver cells. Hepatocyte mono-cultures and hepatocyte-nonparenchymal cell co-cultures responded to heat stress in a similar manner, but the higher metabolic rate of co-cultured cells may have contributed to a better capability of inflamed liver cells for accommodation to stress conditions. In conclusion, the established new primary cell culture models provide suitable tools for studying the hepatic inflammatory and stress response. The results of this study highlight the impact of short-term heat stress on the liver in chickens, underline the mediatory role of oxidative stress in acute stress response, and suggest a fast cellular adaptation potential in liver cells.

The effect of ginger powder and Chinese herbal medicine on production performance, serum metabolites and antioxidant status of laying hens under heat-stress condition

This study was done to evaluate the effects of Chinese herbal medicine (CHM) and ginger powder on layers-production performance, serum metabolites and antioxidant status under heat stress condition. Two hundred and fifty Lohmann layers were randomly divided into 5 different, including two controls and three experimental groups (H1, H2, and H3). Control groups were fed the basic diet without supplementation, while, the feed of three experimental groups was supplemented with 3.32 g CHM, 10 g ginger powder, and 10 g ginger powder+ 3.32 g CHM per kg of diet, respectively. Results showed that feed consumption and production rate were decreased in the HC group, while, feed intake and production significantly improved when birds were given supplemented diet. The production rate and feed intake of the H3 group were even significantly higher than the NC group. The birds that received supplemented diet had higher glucose level compared to HC. Triglycerides and serum cholesterol had significantly decreased level in supplemented groups compared to HC. Fungal catalase (CAT) level was significantly improved in H2 and H3 groups. Nitric oxide (NO), glutathione peroxidase (GSH-PX) and Total Protein (T-AOC) level were significantly improved in supplemented groups. Findings showed that ginger powder and CHM could be a viable alternative to the synthetic antibiotic in poultry feed.