3. Energy.pdf

Receptor proteins in cell signaling Receptor proteins in cell signaling Cell-cell communication  Cellular communications Armongol E et al. in Nat. Rev. Genet. 2020  How do we decode the language Armongol E...

Receptor proteins in cell signaling Receptor proteins in cell signaling Cell-cell communication  Cellular communications Armongol E et al. in Nat. Rev. Genet. 2020  How do we decode the language Armongol E et al. in Nat. Rev. Genet. 2020  Molecular connections between cell types Armongol E et al. in Nat. Rev. Genet. 2020 Cellular communication at the base of physiology It’s not just physical support! Regulation of cell fate choices. Interactions of the membrane components Microtubules (Tubulin) Intermediate filaments Actin filaments The basal lamina Cells in the tissue and fibronectin  Cell-cell interaction and migration PAF= platelet activating factor ICAM= Intercellular adhesion molecule Energy and Nutrition  Energy currency: ATP ADP + Pi + energy from foodstuff molecules → ATP ATP → ADP + Pi + energy usable by cell processes ATP is not transported ATP is not stored to great extent Aerobic/anaerobic catabolic biochemical pathways Oxygen in cellular respiration  Life forms can live without oxygen Several of the unicellular organisms but very few multi-cellular life forms are anaerobic https://biodifferences.net/difference-between-aerobic-and-anaerobic-respiration/ Adaptation to low oxygen levels  Animal cells adapt to varying oxygen levels 1816-1908 1822-1895 French organic chemist French microbiologist and chemist the animal cells can use multiple pathways to accomplish energy production, including a switch to fermentation when necessary  How do cells receive required amount of oxygen? https://blogs.ubc.ca/mrpletsch/ https://www.semanticscholar.org/  reverse-transcribed the RNA and amplified the complementary Link between oxygen and VEGF s of the usual DNA by polymerase chain reaction, using oligonucleotides fter surgical derived from external exons shared by all differentially spliced nd processed VEGF mRNA species (oligonucleotides corresponding to amino specific, 35 S- acids 92-98 and to the six carboxy-terminal amino acids, respec- f mRNA was tively)13. The principal amplified species detected was a 225- coded protein ally identifies secreted and 0 12. In Figs 1 2 3 4 5 6 7 8 28S- 18S- Lane 1. Control cancer cells Lane 2,3. Hypoxia (95% N2) Lane 4,5,6. Hypoxic cells reverted back to normoxia 13-actin Lane 7. Control non-cancerous L8 cells Lane 8. L8 cells hypoxia FIG. 3 VEGF expression in cell cultures is hypoxia-inducible. Cultured cells were exposed to different Northernoxygenblot tensions for 18 h.for analysis TheVegf cells were collected and their RNA extracted, electrophoresed and blot-hybridized with a VEGF- specific probe. Lanes: 1, C6 cells, normal oxygen; 2, C6 cells, 95% nitrogen; 3, C6 cells, catalyst-induced anoxia; 4, same as in lane 3, followed by 8 h incubation under normal oxygen; 5, C6 cells, 20 h growth under normal oxygen in the presence of 10 1'-g ml - 1 cycloheximide; 6, C6 cells, grown in the presence of 10 1'-g ml - 1 cycloheximide, 2 h in normal oxygen and 18 h in catalyst-induced anoxia; 7, L8 cells, normal oxygen; L8 cells, catalyst- induced anoxia. Migration of ribosomal RNA markers (28S and 18S) is Shweiki D. etindicated. al. in Nature 1992 (Eli Keshet Lab) METHODS. Cell growth under hypoxic conditions: Cell lines used were: C6, a  VEGF-receptors and hypoxia Gerber H et al. in J. Biol. Chem. 1997 Regulatory elements and ‘hypoxia factor’  Erythropoiesis and erythropoietin Kidney failure causes anaemia  Erythropoiesis and hypoxia Erythropoietin is a hypoxia inducible gene and its expression is regulated by hypoxia response element (HRE) HIF production (actually stabilization) and binding is hypoxia inducible Transcription factor HIF binds to HRE in a “general mammalian cell” way The EPO enhancer can drive the expression of any reporter in a hypoxia (and hence (HIF-1) inducible manner https://aminoapps.com/c/science/page/blog/aerobic-and-anaerobic-cellular-respiration/  Metabolic adaptation http://hyperphysics.phy-astr.gsu.edu/hbase/Biology/celres.html  Oxygen sensing mechanism in animal cells Nobel Prize 2019: Kaelin, Ratcliffe and Semenza  THEJOURNAL OF B I O ~ I CCHEMISTRY AL Vol. 269, No. 38, Issue of September 23, pp. 23757-23763, 1994 0 1994 by The American Society for Biochemistry and Molecular Biology, Inc. Printed in U.S.A. Transcriptional Regulation of Genes Encoding Glycolytic Enzymes by Hypoxia-inducible Factor l* (Received for publication, April 20, 1994, and in revised form, July 8, 1994) Gregg L. SemenzaS, Peter H. Roth, Hon-Ming Fang,and Guang L. Wang From the Center for Medical Genetics, Departments of Pediatrics and Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-3914 Regulation of Glycolytic Gene Danscription by HIF-1 23759. cm- - + + Hypoxia-inducible factor1 (HIF-1) activates erythro- and kidney(reviewed in Ref. 3). EPO production and secretion hypoxia. FIG.2. Induction ofALDAandPGKl HIF-1 activity is also induced A poietin gene transcription in Hep3B cells subjected to into the circulation have systemic by hypoxia in blood 0,-carrying capacity. effects on erythropoiesis and HYPOXIA B -+-+ RNA in hypoxic cells.non-erythropoietin-producing A, kinetics of in- cells, suggesting a more EPO transcription is activated in Hep3B human hepatoblas- duction. Hep3B general regulatory cellsexposed to were 1% role. We now report AAthat D "...O A RNAs en- toma cells exposed to 1%0, (4), providing a cellular system in., coding the glycolytic enzymes aldolase (ALDA), phos- which to investigate the underlying molecular mechanisms. An 0, for 0-16 h, and totalRNA (10pg) was analyzed by ribonucleasewere for ALDA RNA phoglycerate kinase 1 (PGKl), and pyruvate kinase M enhancer element located in the 3’-flanking region of the hu- protection (172-nucleotide induced by exon assay H- exposure of Hep3B or HeLa cells to man and mouse EPO genes can directhypoxia-inducible tran- inducers of HIF-1(1%0,,cobalt chloride, or desferriox- scription of reporter genes transfected into 0 - protected fragment is shown in this and cycloheximideblockedinduction Hep3B cells (5-11). amine), whereas of Hypoxia-inducible factor 1 (HIF-l), a nuclear protein whose subsequent figures) or by blot hybridiza- glycolytic h@1%02: RNAs andHIF-1activity.Oligonucleotides 0 1DNA2 binding 4 8 1activity 6 is induced by hypoxia, binds to the en- tion for PGKl RNA.B, effect from of cyclohex- theALDA, PGK1, enolase 1, lactate dehydrogenase 1 2 3 4 imide on induction of ALDA A, andand PGKl phosphofructokinase L (PFKL)genes, containing hancer sequence 5”TACGTGCT-3’ (10, 12). Methylation inter- RNA in hypoxic cells. Hep3B sequences HIF-1 bindingsite in the eryth-ference analysis demonstrated that HIF-1 makes contact in the similar to the cells were cultured in 20% 0, (hypoxia,ropoietin -) or enhancer, 1%0, specifically bound HIF-1 present in DNAmajor groove with 2 guanine residueson each strand(12). crude Mutations of this sequence eliminate HIF-1 binding and hy- (hypoxia, +)absence the in (-) ornuclear presenceextracts or affinity-purified PGK 1 preparations. PGKl Sequences from the ALDA, PFKL, and PGKl genes con- poxia-inducible enhancer function (6, 101, implicating HIF-1as (+) of 100 p~ CHX for 16 h. an activator of EPO transcription in hypoxic Hep3B cells. taining HIF-1 bindingsites mediated hypoxia-inducible transcription in transient expression assays. These re- Exposure of Hep3B cells to 1% 0,, cobalt chloride (CoCl,), or sults support the role of HIF-1 aas mediator of adaptive desferrioxamine (DFX) induced EPO expression and HIF-1ac- responses to hypoxia that underlie cellular and systemic tivity, whereas treatment with cycloheximide (CHX) or 2-ami- 2-5-fold in rat myoblasts cultured oxygen homeostasis. a t 2% 0, (1). We assayed nopurine inhibited induction of EPO and HIF-1 (10, 12-14). RNA encoding glycolytic enzymes in human tissue culture cells EPO expression and HIF-1 activity were induced with similar  How hypoxia connects with metabolic pathways Semenza GL et al. in J. Biol. Chem. 1994 Huang D et al. in Acta Biochim, Biophys. Sin 2004  The oxygen sensing mechanism Kaelin, Ratcliffe and Semenza 2019 Nobel Prize 2001 Science Vol. 292, page 464 2001 Science Vol. 292, page 468 Kaelin WG and Ratcliffe PJ in Mol. Cell 2008  Hypoxia in cancer http://www.cancerlink.ru/enstemcellhypoxia.html