Cortisol effect on heat shock proteins in the C2C12 and 3T3-L1 cells

Selection for environmental variance of litter size in rabbits involves genes in pathways controlling animal resilience

Background

Environmental variance (V_E) is partially under genetic control, which means that the V_E of individuals that share the same environment can differ because they have different genotypes. Previously, a divergent selection experiment for V_E of litter size (LS) during 13 generations in rabbit yielded a successful response and revealed differences in resilience between the divergent lines. The aim of the current study was to identify signatures of selection in these divergent lines to better understand the molecular mechanisms and pathways that control V_E of LS and animal resilience. Three methods (F_ST, ROH and varLD) were used to identify signatures of selection in a set of 473 genotypes from these rabbit lines (377) and a base population (96). A whole-genome sequencing (WGS) analysis was performed on 54 animals to detect genes with functional mutations.

Results

By combining signatures of selection and WGS data, we detected 373 genes with functional mutations in their transcription units, among which 111 had functions related to the immune system, stress response, reproduction and embryo development, and/or carbohydrate and lipid metabolism. The genes TTC23L, FBXL20, GHDC, ENSOCUG00000031631, SLC18A1, CD300LG, MC2R, and ENSOCUG00000006264 were particularly relevant, since each one carried a functional mutation that was fixed in one of the rabbit lines and absent in the other line. In the 3ʹUTR region of the MC2R and ENSOCUG00000006264 genes, we detected a novel insertion/deletion (INDEL) variant.

Conclusions

Our findings provide further evidence in favour of V_E as a measure of animal resilience. Signatures of selection were identified for V_E of LS in genes that have a functional mutation in their transcription units and are mostly implicated in the immune response and stress response pathways. However, the real implications of these genes for V_E and animal resilience will need to be assessed through functional analyses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12711-021-00653-y.

In Vitro Selective Anti-Proliferative Effect of Zinc Oxide Nanoparticles Against Co-Cultured C2C12 Myoblastoma Cancer and 3T3-L1 Normal Cells

The zinc oxide (ZnO) nanoparticle has been widely used in biomedical applications and cancer therapy and has been reported to induce a selective cytotoxic effect on cancer cell proliferation. The present study investigated the cytotoxicity of ZnO nanoparticles against co-cultured C2C12 myoblastoma cancer cells and 3T3-L1 adipocytes. Our results showed that the ZnO nanoparticles could be cytotoxic to C2C12 myoblastoma cancer cells than 3T3-L1 cells. The messenger RNA (mRNA) expressions of p53 and bax were significantly increased 114.3 and 118.2 % in the C2C12 cells, whereas 42.5 and 40 % were increased in 3T3-L1 cells, respectively. The mRNA expression of bcl-2 was reduced 38.2 and 28.5 % in the C2C12 and 3T3-L1 cells, respectively, whereas the mRNA expression of caspase-3 was increased 80.7 and 51.6 % in the C2C12 and 3T3-L1 cells, respectively. The protein expressions of p53, bax, and caspase-3 were significantly increased 40, 81.8, and 80 % in C2C12 cells, whereas 20.3, 28.2, and 37.9 % were increased in 3T3-L1 cells, respectively. The mRNA expression of bcl-2 was significantly reduced 32.2 and 22.7 % in C2C12 and 3T3-L1 cells, respectively. Caspase-3 enzyme activity and reactive oxygen species (ROS) were increased in co-cultured C2C12 cells compared to 3T3-L1 cells. Taking all these data together, it may suggest that ZnO nanoparticles severely induce apoptosis in C2C12 myoblastoma cancer cells than 3T3-L1 cells.

Effect of cortisol on bovine oocyte maturation and embryo development in vitro

Glucocorticoids (GCs) are important mediators of key cellular events. Herein, we investigated the effect of adding cortisol to the IVM medium on the acquisition of developmental competency in bovine oocytes. Cortisol (0.01, 0.1, or 1 μg/mL) had no effect on cleavage rates or cell numbers of resulting blastocysts; however, supplementation with 0.1 μg/mL during IVM increased blastocyst rates of in vitro-fertilized bovine oocytes as compared to untreated controls (41 ± 10% vs. 21 ± 1.2%, P < 0.05, respectively). This concentration was chosen to assess changes in the relative expression of potential GC target genes. Oocytes matured in the presence of cortisol and their corresponding cumulus cells did not show changes in expression for genes analyzed as compared to untreated controls. Notably, blastocysts from oocytes matured in cortisol-supplemented medium expressed higher relative levels of glucose transporter 1 (GLUT1), fatty acid synthase (FASN), and heat shock protein 70 (HSP70). This study supports a role for cortisol in the acquisition of bovine oocyte competence. This is evidenced by increased blastocyst development rates and presumably related to elevated embryonic transcripts with roles in glucose and lipid metabolism, as well as the cellular response to stress.

A novel approach for in vitro meat production

The present review describes the possibility of in vitro meat production with the help of advanced co-culturing methods. In vitro meat production method could be a possible alternative for the conventional meat production. Originally, the research on in vitro meat production was initiated by the National Aeronautics and Space Administration (NASA) for space voyages. The required key qualities for accepting in vitro meat for consumption would be good efficiency ratio, increased protein synthesis rate in skeletal muscles, and mimicking the conventional meat qualities. In vitro culturing of meat is possible with the use of skeletal muscle tissue engineering, stem cell, cell co-culture, and tissue culture methods. Co-culture of myoblast and fibroblast is believed as one of the major techniques for in vitro meat production. In our lab, we have co-cultured myoblast and fibroblast. We believe that a billion pounds of in vitro meat could be produced from one animal for consumption. However, we require a great deal of research on in vitro meat production.

Application of cell co-culture system to study fat and muscle cells

Animal cell culture is a highly complex process, in which cells are grown under specific conditions. The growth and development of these cells is a highly unnatural process in vitro condition. Cells are removed from animal tissues and artificially cultured in various culture vessels. Vitamins, minerals, and serum growth factors are supplied to maintain cell viability. Obtaining result homogeneity of in vitro and in vivo experiments is rare, because their structure and function are different. Living tissues have highly ordered complex architecture and are three-dimensional (3D) in structure. The interaction between adjacent cell types is quite distinct from the in vitro cell culture, which is usually two-dimensional (2D). Co-culture systems are studied to analyze the interactions between the two different cell types. The muscle and fat co-culture system is useful in addressing several questions related to muscle modeling, muscle degeneration, apoptosis, and muscle regeneration. Co-culture of C2C12 and 3T3-L1 cells could be a useful diagnostic tool to understand the muscle and fat formation in animals. Even though, co-culture systems have certain limitations, they provide a more realistic 3D view and information than the individual cell culture system. It is suggested that co-culture systems are useful in evaluating the intercellular communication and composition of two different cell types.