Evidence for CTHRC1 Cleavage and Role in Promoting Metabolic Efficiency: Potential Implications for Endurance Athletic Performance

CTHRC1 is a secreted protein that is cleaved in both in vitro and in vivo conditions, and cleavage may be due to protease activity. We hypothesize that cell injury or cell death is associated with the release of a protease that could cleave CTHRC1, allowing for the generation of active CTHRC1 at sites of tissue injury, including myocardial infarction.https://knowledgeconnection.mainehealth.org/lambrew-retreat-2023/1016/thumbnail.jp

Therapeutic and Diagnostic Methods and Compositions Based on Jagged/Notch Proteins and Nucleic Acids

This invention relates to therapeutic and diagnostic methods and compositions based on Jagged/Notch proteins and nucleic acids, and on their role in the signaling pathway relating to endothelial cell migration and/or differentiation. In addition, this invention provides a substantially purified Jagged protein, as well as a substantially purified nucleic acid or segment thereof encoding Jagged protein, or a functionally equivalent derivative, or allelic or species variant thereof. Further, this invention provides a substantially purified soluble Jagged protein and a substantially purified nucleic acid encoding same as well as a recombinant cell comprising a nucleic acid encoding a soluble Jagged protein. Soluble Jagged provides further therapeutic and diagnostic methods relating to diseases, disorders, and conditions involving Jagged/Notch signaling including, inter alia, angiogenesis, differentiation, and control of gene expression

Phosphatidylserine colocalizes with epichromatin in interphase nuclei and mitotic chromosomes

Cycling eukaryotic cells rapidly re-establish the nuclear envelope and internal architecture following mitosis. Studies with a specific anti-nucleosome antibody recently demonstrated that the surface (“epichromatin”) of interphase and mitotic chromatin possesses a unique and conserved conformation, suggesting a role in postmitotic nuclear reformation. Here we present evidence showing that the anionic glycerophospholipid phosphatidylserine is specifically located in epichromatin throughout the cell cycle and is associated with nucleosome core histones. This suggests that chromatin bound phosphatidylserine may function as a nucleation site for the binding of ER and re-establishment of the nuclear envelope

The intracellular translocation of the components of the fibroblast growth factor 1 release complex precedes their assembly prior to export

The release of signal peptideless proteins occurs through nonclassical export pathways and the release of fibroblast growth factor (FGF)1 in response to cellular stress is well documented. Although biochemical evidence suggests that the formation of a multiprotein complex containing S100A13 and Synaptotagmin (Syt)1 is important for the release of FGF1, it is unclear where this intracellular complex is assembled. As a result, we employed real-time analysis using confocal fluorescence microscopy to study the spatio-temporal aspects of this nonclassical export pathway and demonstrate that heat shock stimulates the redistribution of FGF1 from a diffuse cytosolic pattern to a locale near the inner surface of the plasma membrane where it colocalized with S100A13 and Syt1. In addition, coexpression of dominant-negative mutant forms of S100A13 and Syt1, which both repress the release of FGF1, failed to inhibit the stress-induced peripheral redistribution of intracellular FGF1. However, amlexanox, a compound that is known to attenuate actin stress fiber formation and FGF1 release, was able to repress this process. These data suggest that the assembly of the intracellular complex involved in the release of FGF1 occurs near the inner surface of the plasma membrane and is dependent on the F-actin cytoskeleton

Transitory FGF treatment results in the long-lasting suppression of the proliferative response to repeated FGF stimulation.

FGF applied as a single growth factor to quiescent mouse fibroblasts induces a round of DNA replication, however continuous stimulation results in arrest in the G1 phase of the next cell cycle. We hypothesized that FGF stimulation induces the establishment of cell memory, which prevents the proliferative response to repeated or continuous FGF application. When a 2-5 day quiescence period was introduced between primary and repeated FGF treatments, fibroblasts failed to efficiently replicate in response to secondary FGF application. The establishment of “FGF memory” during the first FGF stimulation did not require DNA synthesis, but was dependent on the activity of FGF receptors, MEK, p38 MAPK and NFκB signaling, and protein synthesis. While secondary stimulation resulted in strongly decreased replication rate, we did not observe any attenuation of morphological changes, Erk1/2 phosphorylation and cyclin D1 induction. However, secondary FGF stimulation failed to induce the expression of cyclin A, which is critical for the progression from G1 to S phase. Treatment of cells with a broad range histone deacetylase inhibitor during the primary FGF stimulation rescued the proliferative response to the secondary FGF treatment suggesting that the establishment of “FGF memory” may be based on epigenetic changes. We suggest that “FGF memory” can prevent the hyperplastic response to cell damage and inflammation, which are associated with an enhanced FGF production and secretion. “FGF memory” may present a natural obstacle to the efficient application of recombinant FGFs for the treament of ulcers, ischemias and wounds

Two novel human NUMB isoforms provide a potential link between development and cancer

We previously identified four functionally distinct human NUMB isoforms. Here, we report the identification of two additional isoforms and propose a link between the expression of these isoforms and cancer. These novel isoforms, NUMB5 and NUMB6, lack exon 10 and are expressed in cells known for polarity and migratory behavior, such as human amniotic fluid cells, glioblastoma and metastatic tumor cells. RT-PCR and luciferase assays demonstrate that NUMB5 and NUMB6 are less antagonistic to NOTCH signaling than other NUMB isoforms. Immunocytochemistry analyses show that NUMB5 and NUMB6 interact and complex with CDC42, vimentin and the CDC42 regulator IQGAP1 (IQ (motif) GTPase activating protein 1). Furthermore, the ectopic expression of NUMB5 and NUMB6 induces the formation of lamellipodia (NUMB5) and filopodia (NUMB6) in a CDC42- and RAC1-dependent manner. These results are complemented by in vitro and in vivo studies, demonstrating that NUMB5 and NUMB6 alter the migratory behavior of cells. Together, these novel isoforms may play a role in further understanding the NUMB function in development and cancer