Table of Contents
The Effect of Environmental Conditions on Cell Fate
2.1] Heat Shock-Induced Epigenetic Modifications Enhance Adipogenic Differentiation in Bovine Mesenchymal Stem Cells
Mesenchymal stem cells (MSCs) present remarkable potential for applications in cell therapy and cultured meat (CM) production, thanks to their accessibility, multilineage differentiation capabilities, and relatively simple, cost-effective cultivation techniques. However, their limited self-renewal and slow differentiation rates pose significant hurdles for scalable production. This highlights the need for advancements in culture and differentiation methodologies. Building on our prior research indicating that brief heat shock (HS) induces epigenetic changes influencing cell fate, our current findings demonstrate that a short, well-timed thermal shock significantly accelerates adipogenic differentiation in bovine MSCs. Not only do HS-preconditioned cells differentiate more rapidly, but they also produce fat cells with an improved fatty acid composition. These results suggest that pre-treating MSCs with heat shock can substantially alter cellular identity and developmental trajectories. By exploring the underlying mechanisms of this effect, we seek to reduce dependency on chemical additives and growth factors in culture media. Specifically, optimizing MSC adipogenesis through cost-effective HS preconditioning could revolutionize their application in the CM industry. This advancement holds promise for streamlining differentiation processes, reducing production timelines, increasing yield, and enhancing both meat quality and differentiation efficiency in CM production. On a broader scale, our results offer valuable insights into evolutionary development and regenerative processes in cattle.
2.2] Stress Can Rewire Mesenchymal Stem Cell Memory
Mesenchymal stem cells (MSCs) are central to tissue repair and homeostasis, adapting to environmental stressors through a poorly understood mechanism of cellular memory. Our study reveals how heat stress (HS) triggers long-lasting transcriptional and epigenetic changes in MSCs, effectively “rewiring” their response to future challenges.
We found that bovine umbilical cord-derived MSCs exposed to HS exhibit slowed cell cycles, heightened oxidative stress, and persistent changes in gene expression, driven by dynamic alterations in chromatin accessibility and DNA methylation. Sequential HS treatments demonstrated that these changes create a form of epigenetic memory, enabling MSCs to respond more efficiently—or, in some cases, more sensitively—to repeated stress. Through transcriptomic and epigenomic profiling, we aim to identify key memory-associated pathways, including oxidative stress response networks and chromatin remodeling factors, that mediate adaptive resilience.
Mechanistically, transcription factors and chromatin remodelers, such as histone deacetylases and histone methyltransferases, were shown to be crucial for embedding and maintaining stress memory. Functional disruption of these regulators using CRISPR/Cas9 and RNAi will confirm their role in modulating MSC resilience and plasticity during subsequent stress events.
Our findings will provide critical insights into how environmental stress imprints long-term epigenetic memory in MSCs, with significant implications for regenerative medicine and the development of stress-resilient therapies.
2.3] transmitted epigenetic changes associated with heat stress in cattle
It has been shown that heat stress may have a long-lasting impact on the bovine fetus and its progeny. Heat stress related in-utero programming may result in reduced birth weight of calves, altered mammary development and impaired innate and cellular immunity; effects may be transmitted to the second generation. The mechanisms responsible for this programming are unknown.
Transcriptional and epigenetic patterns form primarily during embryonic development and cell differentiation, and environmental factors have been shown to influence those patterns. Often, these changes are detrimental. If environmental factors induce epigenetic alterations in the gametes, they may affect not only the phenotype but also the epigenetic patterns of the offspring. Adult stem cells are the longest living cell population in the body, and are therefore exposed to many stressful environmental conditions that might affect their function. The main goal of this research is to delineate the effect of heat stress on stem cell function and to identify the mechanisms underlying the epigenetic aberrations. I will focus primarily on mesenchymal stem cells (MSC), which can differentiate into various lineages and may suppress inflammation because they are essential for the homeostasis and regeneration of many tissues in the body and, therefore, may be most susceptible to the cellular and epigenetic alterations and their phenotypic consequences. We study for the first time the functional and epigenomic changes in the fetus and three subsequent generations caused by in utero heat stress, using cultured bovine MSC from various tissues. We plan to investigate the altered gene expression programs, the aberrant CpG methylation patterns and chromatin accessibilities of MSCs by whole-transcriptome RNA-seq analysis, reduced representation bisulfite sequencing (RRBS), and an assay for transposase-accessible chromatin using sequencing (ATAC-seq). MSCs will be isolated from four relevant tissues (uterus, placenta, mammary gland and umbilical cord), cultured and their molecular signatures analyzed. The general hypothesis is that a major reason that heat stress has such a profound detrimental effect on cattle is because it results in aberrant epigenetic patterns in MSC and thereby compromises their function. Results from this project will, for the first time, establish the foundation for transgenerational epigenetic studies in large animals, and ultimately may provide a basis for important practical agricultural ramifications. At the basic level, they will expand our understanding of the underlying molecular mechanisms and epigenetic alterations that are involved in the cellular response to heat stress and its long term effects.
