The murine dialysis fistula model exhibits a senescence phenotype: pathobiological mechanisms and therapeutic potential

There is no therapy that promotes maturation and functionality of a dialysis arteriovenous fistula (AVF). The search for such therapies largely relies on evaluation of vascular responses and putative therapies in experimental AVFs. We studied an AVF in mice with chronic kidney disease (CKD). We demonstrate numerous stressors in the vein of the AVF-CKD group, including pathological shear, mitogenic, inflammatory, and hypoxia-reoxygenation stress. Because stress promotes premature senescence, we examined whether senescence is induced in the vein of the AVF-CKD model. We demonstrate a senescence phenotype in the AVF-CKD model, as indicated by increased expression of p16Ink4a, p21Cip1, and p53 and expected changes for certain senescence-associated microRNAs. RNA-sequencing analysis demonstrated differential expression of ~10,000 genes, including upregulation of proinflammatory and proliferative genes, in the vein of the AVF-CKD group. The vein in the AVF-CKD group exhibited telomere erosion and increased senescence-associated β-galactosidase activity and staining. Senescence was induced in the artery of the AVF-CKD group and in the vein of the AVF without CKD. Finally, given the rapidly rising clinical interest in senolytics, we provide proof of concept of senolytics as a therapeutic approach by demonstrating that senolytics decrease p16Ink4a expression in the AVF-CKD model. This study introduces a novel concept underlying the basis for maturational and functional failure in human dialysis AVFs and identifies a new target for senolytic therapy.

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Repurposing cabozantinib with therapeutic potential in KIT-driven t(8;21) acute myeloid leukaemias

Cancer Gene Therapy ◽

10.1038/s41417-021-00329-1 ◽

2021 ◽

Author(s):

Kuan-Wei Su ◽

Da-Liang Ou ◽

Yu-Hsuan Fu ◽

Hwei-Fang Tien ◽

Hsin-An Hou ◽

...

Keyword(s):

Tyrosine Kinase ◽

Ribosome Biogenesis ◽

Kinase Inhibitor ◽

Therapeutic Potential ◽

Xenograft Model ◽

Sequencing Analysis ◽

Dependent Manner ◽

Leukocyte Activation ◽

Mouse Xenograft Model ◽

Acute Myeloid

AbstractCabozantinib is an orally available, multi-target tyrosine kinase inhibitor approved for the treatment of several solid tumours and known to inhibit KIT tyrosine kinase. In acute myeloid leukaemia (AML), aberrant KIT tyrosine kinase often coexists with t(8;21) to drive leukaemogenesis. Here we evaluated the potential therapeutic effect of cabozantinib on a selected AML subtype characterised by t(8;21) coupled with KIT mutation. Cabozantinib exerted substantial cytotoxicity in Kasumi-1 cells with an IC50 of 88.06 ± 4.32 nM, which was well within clinically achievable plasma levels. The suppression of KIT phosphorylation and its downstream signals, including AKT/mTOR, STAT3, and ERK1/2, was elicited by cabozantinib treatment and associated with subsequent alterations of cell cycle- and apoptosis-related molecules. Cabozantinib also disrupted the synthesis of an AML1-ETO fusion protein in a dose- and time-dependent manner. In a mouse xenograft model, cabozantinib suppressed tumourigenesis at 10 mg/kg and significantly prolonged survival of the mice. Further RNA-sequencing analysis revealed that mTOR-mediated signalling pathways were substantially inactivated by cabozantinib treatment, causing the downregulation of ribosome biogenesis and glycolysis, along with myeloid leukocyte activation. We suggest that cabozantinib may be effective in the treatment of AML with t(8;21) and KIT mutation. Relevant clinical trials are warranted.

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Modeling Approach for a Fluid Movement Induced by Magnetic Forces for Viscous Loss Reduction of MRF Brakes and Clutches

Volume 2: Mechanics and Behavior of Active Materials; Integrated System Design and Implementation; Bio-Inspired Materials and Systems; Energy Harvesting ◽

10.1115/smasis2012-8135 ◽

2012 ◽

Author(s):

Dirk Güth ◽

Markus Schamoni ◽

Jürgen Maas

Keyword(s):

High Speed ◽

Complete Separation ◽

Loss Reduction ◽

Proof Of Concept ◽

Idle Mode ◽

Modeling Approach ◽

Induced Drag ◽

Viscous Loss ◽

Novel Concept ◽

Viscous Torque

A challenge that is opposed to a commercial use of actuators like brakes and clutches based on magnetorheological fluids (MRF), are durable no-load losses, because a complete torque-free separation due to the permanent liquid intervention is inherently not yet possible. In this paper, the necessity of reducing these durable no-load losses will be shown by measurements performed with a MRF brake for high rotational speeds of 6000min−1. The detrimental high viscous torque motivates the introduction of a novel concept that allows a controlled movement of the MRF from an active shear gap into an inactive shear gap, enabling a complete separation of the fluid engaging surfaces. This behavior is modeled by the use of the ferrohydrodynamics and simulations are performed for different transitions between braking and idle mode. Images of high speed video capturing, showing the motion of MRF induced by a magnetic field, are presented for the validation of the modeling approach. Measurements performed with a realized proof-of-concept actuator show that the viscous induced drag torque can be reduced significantly.

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Exendin-4 alleviates angiotensin II-induced senescence in vascular smooth muscle cells by inhibiting Rac1 activation via a cAMP/PKA-dependent pathway

AJP Cell Physiology ◽

10.1152/ajpcell.00151.2014 ◽

2014 ◽

Vol 307 (12) ◽

pp. C1130-C1141 ◽

Cited By ~ 23

Author(s):

Liang Zhao ◽

Ai Q. Li ◽

Teng F. Zhou ◽

Meng Q. Zhang ◽

Xiao M. Qin

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Therapeutic Potential ◽

Muscle Cells ◽

Premature Senescence ◽

Ang Ii ◽

Age Related ◽

Dependent Pathway

Vascular aging has been implicated in the progression of diabetes and age-related cardiovascular disorders. Glucagon-like peptide-1 (GLP-1) is an incretin hormone capable of cytoprotective actions in addition to its glucose-lowering effect. The present study was undertaken to examine whether Exendin-4, a specific ligand for the GLP-1 receptor, could prevent angiotensin (ANG) II-induced premature senescence in vascular smooth muscle cells (VSMCs) and to determine the underlying mechanism involved. Senescence-associated β-galactosidase (SA β-gal) assay showed that ANG II induced premature senescence of VSMCs. Pretreatment with Exendin-4 significantly attenuated ANG II-induced generation of H2O2 and the subsequent VSMC senescence. These effects were, however, reversed in the presence of exendin fragment 9–39, a GLP-1 receptor antagonist, or PKI14-22. Moreover, a marked increase in the levels of p53 and p21 induced by ANG II was blunted by the treatment with Exendin-4. Nevertheless, Exendin-4 failed to decrease ANG II-induced expression of NAD(P)H oxidase 1 (Nox1), NAD(P)H oxidase 4 (Nox4), p22phox, or p47phox in VSMCs. Mechanistically, Exendin-4 blocked ANG II-induced Rac1 activation through the cAMP/PKA signaling cascade. Specifically, NSC23766, a Rac1 inhibitor, abrogated the suppressive effects of Exendin-4 on ANG II-induced premature senescence and H2O2 generation, respectively. Thus Exendin-4 confers resistance to ANG II-induced superoxide anion generation from NAD(P)H oxidase and the resultant VSMC senescence by inhibiting Rac1 activation via a cAMP/PKA-dependent pathway. These findings demonstrate that GLP-1 as well as its analogs (GLP-1-related reagents) may hold therapeutic potential in the treatment of diabetes with cardiovascular disease.

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A transcriptomics-guided drug target discovery strategy identifies novel receptor ligands for lung regeneration

10.1101/2021.05.18.444655 ◽

2021 ◽

Author(s):

Xinhui Wu ◽

Sophie Bos ◽

Thomas M Conlon ◽

Meshal Ansari ◽

Vicky Verschut ◽

...

Keyword(s):

Cigarette Smoke ◽

Drug Target ◽

Therapeutic Potential ◽

Chronic Obstructive ◽

Sequencing Analysis ◽

Receptor Ligands ◽

Drug Target Discovery ◽

Target Discovery ◽

Alveolar Epithelial

Currently, there is no pharmacological treatment targeting defective tissue repair in chronic disease. Here we utilized a transcriptomics-guided drug target discovery strategy using gene signatures of smoking-associated chronic obstructive pulmonary disease (COPD) and from mice chronically exposed to cigarette smoke, identifying druggable targets expressed in alveolar epithelial progenitors of which we screened the function in lung organoids. We found several drug targets with regenerative potential of which EP and IP prostanoid receptor ligands had the most significant therapeutic potential in restoring cigarette smoke-induced defects in alveolar epithelial progenitors in vitro and in vivo. Mechanistically, we discovered by using scRNA-sequencing analysis that circadian clock and cell cycle/apoptosis signaling pathways were enriched in alveolar epithelial progenitor cells in COPD patients and in a relevant model of COPD, which was prevented by PGE2 or PGI2 mimetics. Conclusively, specific targeting of EP and IP receptors offers therapeutic potential for injury to repair in COPD.

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4547 Understanding the molecular mechanism of natural killer cell deficiency to improve natural killer cell in vitro differentiation for therapeutics

Journal of Clinical and Translational Science ◽

10.1017/cts.2020.101 ◽

2020 ◽

Vol 4 (s1) ◽

pp. 20-20

Author(s):

Megan Schmit ◽

Ryan Baxley ◽

Emily Mace ◽

Jordan Orange ◽

Jeffery Miller ◽

...

Keyword(s):

Dna Replication ◽

Natural Killer Cell ◽

Nk Cells ◽

Natural Killer ◽

Nk Cell ◽

Killer Cell ◽

Premature Senescence ◽

Replication Proteins ◽

Telomere Erosion

OBJECTIVES/GOALS: Natural killer (NK) cells are a potential cancer therapeutic but expanding NK cells efficiently in vitro is difficult. Natural killer cell deficiency (NKD), a primary immune deficiency affecting only NK cells, is caused by defects in several DNA replication proteins. By studying NKD we will achieve better NK cell in vitro differentiation. METHODS/STUDY POPULATION: One patient with NKD has a compound heterozygous mutation in the essential DNA replication protein MCM10. We hypothesize that in individuals with NKD, dramatic telomere erosion from abnormal DNA replication leads to premature senescence and the loss of NK cells. To test our hypothesis, we will knockout one allele of MCM10 or over express MCM10 in NK cells isolated from blood. We will then monitor telomere length, expansion and cytotoxic activity of these NK cells. To understand the role of MCM10 in early stages of NK cell development we will deplete MCM10 in induced pluripotent stem cells and differentiate these cells into NK cells. During this differentiation we will monitor progression through NK cell developmental stages as well as telomere length and senescence markers. RESULTS/ANTICIPATED RESULTS: Telomeres insulate chromosomes and induce permanent growth arrest (senescence) when they are critically short. We have demonstrated that depletion of a DNA replication protein causes telomere erosion and increases senescence markers. NK cells have shorter telomeres and lower telomerase expression than other immune cells. We predict, this relatively poor telomere maintenance sensitizes NK cells to telomere loss upon depletion of replication proteins. During in vitro differentiation, we expect NK cell precursors to undergo premature senescence secondary to telomere shortening. Furthermore, we expect supplementation of DNA replication proteins will enhance NK cell expansion and maturation. DISCUSSION/SIGNIFICANCE OF IMPACT: NKD patients have provided the scientific community with clues as to what proteins NK cells rely on for their development. This project aims not only to understand why these proteins are critical, but to harness that information for cellular anti-cancer therapeutics.

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FGFR3 signaling induces a reversible senescence phenotype in chondrocytes similar to oncogene-induced premature senescence

Developmental Biology ◽

10.1016/j.ydbio.2010.05.341 ◽

2010 ◽

Vol 344 (1) ◽

pp. 508

Author(s):

Pavel Krejci ◽

Jirina Prochazkova ◽

Jiri Smutny ◽

Katarina Chlebova ◽

Patricia Lin ◽

...

Keyword(s):

Premature Senescence ◽

Senescence Phenotype

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FGFR3 signaling induces a reversible senescence phenotype in chondrocytes similar to oncogene-induced premature senescence

Bone ◽

10.1016/j.bone.2010.03.021 ◽

2010 ◽

Vol 47 (1) ◽

pp. 102-110 ◽

Cited By ~ 37

Author(s):

Pavel Krejci ◽

Jirina Prochazkova ◽

Jiri Smutny ◽

Katarina Chlebova ◽

Patricia Lin ◽

...

Keyword(s):

Premature Senescence ◽

Senescence Phenotype

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Heat shock induces apoptosis in human embryonic stem cells but a premature senescence phenotype in their differentiated progeny

Cell Cycle ◽

10.4161/cc.21595 ◽

2012 ◽

Vol 11 (17) ◽

pp. 3260-3269 ◽

Cited By ~ 21

Author(s):

Larisa L. Alekseenko ◽

Victoria I. Zemelko ◽

Valery V. Zenin ◽

Nataly A. Pugovkina ◽

Irina V. Kozhukharova ◽

...

Keyword(s):

Stem Cells ◽

Embryonic Stem Cells ◽

Heat Shock ◽

Human Embryonic Stem Cells ◽

Embryonic Stem ◽

Premature Senescence ◽

Senescence Phenotype

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Dysfunctional telomeres trigger cellular senescence mediated by cyclic GMP-AMP synthase

Journal of Biological Chemistry ◽

10.1074/jbc.ra120.012962 ◽

2020 ◽

Vol 295 (32) ◽

pp. 11144-11160 ◽

Cited By ~ 4

Author(s):

Salim Abdisalaam ◽

Souparno Bhattacharya ◽

Shibani Mukherjee ◽

Debapriya Sinha ◽

Kalayarasan Srinivasan ◽

...

Keyword(s):

Cellular Senescence ◽

Cyclic Gmp ◽

Imaging Techniques ◽

Common Mechanism ◽

Premature Senescence ◽

Dna Sensing ◽

Dna Double Strand Breaks ◽

Telomere Shortening ◽

Strand Breaks ◽

Senescence Phenotype

Defective DNA damage response (DDR) signaling is a common mechanism that initiates and maintains the cellular senescence phenotype. Dysfunctional telomeres activate DDR signaling, genomic instability, and cellular senescence, but the links among these events remains unclear. Here, using an array of biochemical and imaging techniques, including a highly regulatable CRISPR/Cas9 strategy to induce DNA double strand breaks specifically in the telomeres, ChIP, telomere immunofluorescence, fluorescence in situ hybridization (FISH), micronuclei imaging, and the telomere shortest length assay (TeSLA), we show that chromosome mis-segregation due to imperfect DDR signaling in response to dysfunctional telomeres creates a preponderance of chromatin fragments in the cytosol, which leads to a premature senescence phenotype. We found that this phenomenon is caused not by telomere shortening, but by cyclic GMP–AMP synthase (cGAS) recognizing cytosolic chromatin fragments and then activating the stimulator of interferon genes (STING) cytosolic DNA-sensing pathway and downstream interferon signaling. Significantly, genetic and pharmacological manipulation of cGAS not only attenuated immune signaling, but also prevented premature cellular senescence in response to dysfunctional telomeres. The findings of our study uncover a cellular intrinsic mechanism involving the cGAS-mediated cytosolic self-DNA–sensing pathway that initiates premature senescence independently of telomere shortening.

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Developing chemokine mutants with improved proteoglycan affinity and knocked-out GPCR activity as anti-inflammatory recombinant drugs

Biochemical Society Transactions ◽

10.1042/bst0340435 ◽

2006 ◽

Vol 34 (3) ◽

pp. 435-437 ◽

Cited By ~ 16

Author(s):

H. Potzinger ◽

E. Geretti ◽

B. Brandner ◽

V. Wabitsch ◽

A.-M. Piccinini ◽

...

Keyword(s):

Therapeutic Potential ◽

Inflammatory Diseases ◽

G Protein Coupled Receptors ◽

Dominant Negative ◽

Wild Type ◽

In Vivo Experiments ◽

Novel Concept ◽

G Protein Coupled ◽

Chemotactic Gradient

The interaction of chemokines and GAGs (glycosaminoglycans) on endothelial surfaces is a crucial step for establishing a chemotactic gradient which leads to the functional presentation of chemokines to their GPCRs (G-protein-coupled receptors) and thus to activation of approaching leucocytes. Based on molecular modelling, biophysical investigations, cell-based and in vivo experiments, we have developed a novel concept for therapeutically interfering with chemokine–GAG interactions, namely dominant-negative chemokine mutants with improved GAG binding affinity and knocked-out GPCR activity. These recombinant proteins displace their wild-type chemokine counterparts from the natural proteoglycan co-receptors without being able to activate leucocytes via GPCRs. Our mutant chemokines therefore represent the first protein-based GAG antagonists with high therapeutic potential in inflammatory diseases.

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