Project description:Human death marks the end of organismal life under conditions such that the components of the human body continue to be alive. Such postmortem cellular survival depends on the nature (Hardy scale) of human death. Slow and expected death typically result from terminal illnesses and includes a prolonged terminal phase of life. As such organismal death process unfolds, do cells of the human body adapt for postmortem cellular survival? Organs with low energy cost-of-living, such as the skin, are better suited for postmortem cellular survival. In this work, the effect of different durations of terminal phase of human life on postmortem changes in cellular gene expression was investigated using RNA sequencing data of 701 human skin samples from the Genotype-Tissue Expression database. Longer terminal phase (slow-death) was associated with a more robust induction of survival pathways (PI3K-Akt signaling) in postmortem skin. Such cellular survival response was associated with the upregulation of embryonic developmental transcription factors such as FOXO1, FOXO3, ATF4 and CEBPD. Upregulation of PI3K-Akt signaling was independent of sex or duration of death-related tissue ischemia. Analysis of single nucleus RNA-seq of post-mortem skin tissue specifically identified the dermal fibroblast compartment to be most resilient as marked by adaptive induction of PI3K-Akt signaling. Prospective studies depicted hypomethylation of PI3K-Akt signaling genes in slow compared to fast human death. Compared to fast death, slow death also induced angiogenic pathways in the dermal endothelial cell compartment of postmortem human skin. In contrast, specific pathways supporting functional properties of the skin as an organ were downregulated following slow death. Such pathways included melanogenesis and those representing the skin extracellular matrix. Efforts to understand the significance of death as a biological variable in influencing the transcriptomic composition of surviving component tissues has far-reaching implications including rigorous interpretation of experimental data collected from the dead and mechanisms involved in transplant-tissue obtained from dead donors.
Project description:Fast and slow skeletal muscles show different characteristics and phenotypes. This data obtained from microarray includes the comparison of normal fast plantaris and slow soleus muscles of adult rats. Characters of slow muscle are strongly dependent on the level of muscular activity. Denervation silences the muscular activity. Therefore, we determined the effects of denervation on gene expression in slow soleus muscle of adult rats.
Project description:Fast and slow skeletal muscles show different characteristics and phenotypes. This data obtained from microarray includes the comparison of normal fast plantaris and slow soleus muscles of adult rats. Characters of slow muscle are strongly dependent on the level of muscular activity. Denervation silences the muscular activity. Therefore, we determined the effects of denervation on gene expression in slow soleus muscle of adult rats. Denervation was performed by transection (~5 mm) of left sciatic nerve at the gluteal level. No treatments were made in the normal control rats. Sampling of soleus and/or plantaris was performed in both normal and experimental groups 28 days after the surgery.
Project description:We performed the first quantitative proteomics analysis of differences between striated (fast) and catch (slow) adductor muscle in Yesso scallop (Patinopecten yessoensis), with the goal to uncover muscle specific genes and proteins, as well as enzymes of metabolic pathways in fast and slow adductor muscle of scallops. The present findings highlight the functional roles of muscle contractile proteins, calcium signaling pathways, membrane and extracellular matrix proteins, and glycogen metabolism involved in the different contractile and metabolic properties between fast and slow muscles. The present findings will help better understand the molecular basis underlying muscle contraction and its physiological regulation in invertebrates.
Project description:Comparing the gene expression profiles of slow and fast skeletal muscle (soleus VS FDB) with either amplified RNA (cRNA probes) or original mRNA (cDNA probes). The fidelity of mRNA amplification method in identifying the gene expression profiles of our samples were validated. Keywords: cell type comparison
Project description:In order to invetigate the impact of CpG methylation on gene expression, transcriptomic profiling using microarray were conducted on the fast and slow type myofibers.
Project description:To identify genes and the molecular pathways involved in the regulation of mesenchymal stem cells (MSCs) exposure to various matrix viscoelasticity, we performed RNA-sequence of MSCs in fast stress relaxation (FAST), medium stress relaxation (MEDIUM) and slow stress relaxation (SLOW) matrix.
Project description:Amyotrophic lateral sclerosis (ALS) is a lethal motor neuron disease that progressively debilitates neuronal cells that control voluntary muscle activity. In a mouse model of ALS that expresses mutated human superoxide dismutase 1 (SOD1-G93A) skeletal muscle is one of the tissues affected early by mutant SOD1 toxicity. Fast-twitch and slow-twitch muscles are differentially affected in ALS patients and in the SOD1-G93A model, fast-twitch muscles being more vulnerable. We used miRNA microarrays to investigate miRNA alterations in fast-twitch (EDL) and slow-twitch (soleus) skeletal muscles of symptomatic SOD1-G93A animals and their age-matched wild type littermates.
Project description:Amyotrophic lateral sclerosis (ALS) is a lethal motor neuron disease that progressively debilitates neuronal cells that control voluntary muscle activity. In a mouse model of ALS that expresses mutated human superoxide dismutase 1 (SOD1-G93A) skeletal muscle is one of the tissues affected early by mutant SOD1 toxicity. Fast-twitch and slow-twitch muscles are differentially affected in ALS patients and in the SOD1-G93A model, fast-twitch muscles being more vulnerable. We used miRNA microarrays to investigate miRNA alterations in fast-twitch (EDL) and slow-twitch (soleus) skeletal muscles of symptomatic SOD1-G93A animals and their age-matched wild type littermates. At age of 90 days RNA was extracted from extensor digitorum longus (EDL) and soleus (SOL) muscles of male SOD1-G93A animals and their age-matched wild type male littermates. RNA was hybridized on Affymetrix Multispecies miRNA-2_0 Array.
Project description:Mycobacterium tuberculosis infects a third of the world's population. Primary tuberculosis involving active fast bacterial replication is often followed by asymptomatic latent tuberculosis, which is characterised by slow or non-replicating bacteria. Reactivation of the latent infection involving a switch back to active bacterial replication can lead to post-primary transmissible tuberculosis. Mycobacterial mechanisms involved in slow growth or switching growth rate provide rational targets for the development of new drugs against persistent mycobacterial infection. Using chemostat culture to control growth rate we screened a transposon mutant library by Transposon site hybridization (TraSH) selection to define the genetic requirements for slow and fast growth of Mycobacterium bovis (BCG) and for the requirements of switching growth rate. We identified 84 genes that are exclusively required for slow growth (69 hours doubling time) and 256 genes required for switching from slow to fast growth. To validate these findings we performed experiments using individual M. tuberculosis and M. bovis BCG knock out mutants. We have demonstrated that growth rate control is a carefully orchestrated process which requires a distinct set of genes encoding several virulence determinants, gene regulators and metabolic enzymes. The mce1 locus appears to be a component of the switch to slow growth rate, which is consistent with the proposed role in virulence of M. tuberculosis. These results suggest novel perspectives for unravelling the mechanisms involved in the switch between acute and persistent TB infections and provide a means to study aspects of this important phenomenon in vitro. Data is also available from http://bugs.sgul.ac.uk/E-BUGS-83