Dysregulated epidermal growth factor and tumor growth factor-beta receptor signaling through GFAP-ACTA2 protein interaction in liver fibrosis
PAKISTAN JOURNAL OF MEDICAL SCIENCES
Authors: Hassan, Sobia; Zil-E-Rubab; Shah, Hussain; Shawana, Summayya
Abstract
Objective: Viral hepatitis is associated with high morbidity and mortality. Identification of biological pathways involved in hepatic fibrosis resulting from chronic hepatitis C are essential for better management of patients. Constructing the HCV-human protein interaction network through bioinformatics may enable us to discover diagnostic biological pathways. We investigated to identify dysregulated pathways and gene enrichment based on actin alpha 2 (ACTA2) and glial fibrillar acidic protein (GFAP) interaction network analysis in hepatic fibrosis. Methods: This is an in-silico study conducted at Ziauddin University from March,2019 to September 2019. Enrichment and protein-protein interaction (PPI) network analysis of the identified proteins: GFAP and ACTA2 along with their mapped gene data sets was performed using FunRich version 3.1.3. Results: Biological pathway grouping showed enrichment of proteins (85.7%) in signalling pathway by epidermal growth factor receptor (EGFR) and Tumor growth factor (TGF)-beta Receptor followed by signaling by PDGF, FGFR and NGF (71.4%) (p < 0.001). SRC, PRKACA, PRKCA and PRKCD were enriched in both EGFR and TGF-beta Signalling pathways. Conclusion: EGFR and TGF-beta signalling pathways were enriched in liver fibrosis. SRC, PRKACA, PRKCA and PRKCD were enriched and differentially expressed in both EGFR and TGF-beta signalling pathways
Spaceflight Activates Protein Kinase C Alpha Signaling and Modifies the Developmental Stage of Human Neonatal Cardiovascular Progenitor Cells
STEM CELLS AND DEVELOPMENT
Authors: Baio, Jonathan; Martinez, Aida F.; Bailey, Leonard; Hasaniya, Nahidh; Pecaut, Michael J.; Kearns-Jonker, Mary
Abstract
Spaceflight impacts cardiovascular function in astronauts; however, its impact on cardiac development and the stem cells that form the basis for cardiac repair is unknown. Accordingly, further research is needed to uncover the potential relevance of such changes to human health. Using simulated microgravity (SMG) generated by two-dimensional clinorotation and culture aboard the International Space Station (ISS), we assessed the effects of mechanical unloading on human neonatal cardiovascular progenitor cell (CPC) developmental properties and signaling. Following 6-7 days of SMG and 12 days of ISS culture, we analyzed changes in gene expression. Both environments induced the expression of genes that are typically associated with an earlier state of cardiovascular development. To understand the mechanism by which such changes occurred, we assessed the expression of mechanosensitive small RhoGTPases in SMG-cultured CPCs and observed decreased levels of RHOA and CDC42. Given the effect of these molecules on intracellular calcium levels, we evaluated changes in noncanonical Wnt/calcium signaling. After 6-7 days under SMG, CPCs exhibited elevated levels of WNT5A and PRKCA. Similarly, ISS-cultured CPCs exhibited elevated levels of calcium handling and signaling genes, which corresponded to protein kinase C alpha (PKC alpha), a calcium-dependent protein kinase, activation after 30 days. Akt was activated, whereas phosphorylated extracellular signal-regulated kinase levels were unchanged. To explore the effect of calcium induction in neonatal CPCs, we activated PKC alpha using hWnt5a treatment on Earth. Subsequently, early cardiovascular developmental marker levels were elevated. Transcripts induced by SMG and hWnt5a-treatment are expressed within the sinoatrial node, which may represent embryonic myocardium maintained in its primitive state. Calcium signaling is sensitive to mechanical unloading and directs CPC developmental properties. Further research both in space and on Earth may help refine the use of CPCs in stem cell-based therapies and highlight the molecular events of development.