Senescent cells exacerbate COVID-19
Cellular senescence is a state elicited in response to stress signals and is associated with a damaging secretory phenotype. The number of senescent cells ...increases with advanced age and this in turn drives age-related diseases. Camell
et al.
show that senescent cells have an amplified inflammatory response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (see the Perspective by Cox and Lord). This response is communicated to nonsenescent cells, suppressing viral defense mechanisms and increasing the expression of viral entry proteins. In old mice infected with a SARS-CoV-2–related virus, treatment with senolytics to reduce the senolytic cell burden reduced mortality and increased antiviral antibodies.
Science
, abe4832, this issue p.
eabe4832
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SARS-CoV-2 amplifies the damaging senescent cell secretory state, and drugs that selectively clear senescent cells reduce mortality in infected aged mice.
INTRODUCTION
The COVID-19 pandemic revealed enhanced vulnerability of the elderly and chronically ill to adverse outcomes upon severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Senescence is a cell fate elicited by cellular stress that results in changes in gene expression, morphology, metabolism, and resistance to apoptosis. Senescent cells (SnCs) secrete pro-inflammatory factors, called the senescence-associated secretory phenotype (SASP). SnCs accumulate with age and drive chronic inflammation. In human cells and tissues and using a new infection paradigm, we asked whether SnCs are a cause of adverse outcomes of infection with aging. This is relevant because SnCs can be selectively eliminated in vivo with a new class of therapeutics called senolytics, potentially affording a new approach to treat COVID-19.
RATIONALE
We hypothesized that SnCs, because of their pro-inflammatory SASP, might have a heightened response to pathogen-associated molecular pattern (PAMP) factors, resulting in increased risk of cytokine storm and multi-organ failure. To test this, we treated senescent and nonsenescent human cells with the PAMPs lipopolysaccharide (LPS) and SARS-CoV-2 spike protein (S1) and measured the SASP and its effect on non-SnCs. Similarly, old and progeroid mice were challenged with LPS, and we measured the SASP. Previously, we created a “normal microbial experience” (NME) for mice by transmitting environmental pathogens to specified-pathogen–free (SPF) mice through exposure to pet store mice or their bedding. The first pathogen transferred was mouse hepatitis virus (MHV), a β-coronavirus closely related to SARS-CoV-2. NME rapidly killed aged SPF mice known to have an increased burden of SnCs compared with young SPF mice, which survive NME. This afforded an experimental paradigm to test whether senolytics blunt adverse outcomes in β-coronavirus infection.
RESULTS
Human endothelial SnCs became hyperinflammatory in response to challenge with LPS and S1, relative to non-SnCs. The PAMP-elicited secretome of SnCs caused increased expression of viral entry proteins and reduced expression of antiviral genes in nonsenescent human endothelial and lung epithelial cells, and the proximity of these events was established in human lung biopsies. Treatment of old mice with LPS significantly increased SASP expression in several organs relative to young mice, confirming our hypothesis in vivo. Similarly, old mice exposed to NME displayed a significant multi-organ increase in SnCs and the SASP, impaired immune response to MHV, and 100% mortality, whereas inoculation with antibodies against MHV before NME afforded complete rescue of mortality. Treating old mice with the senolytic fisetin, which selectively eliminates SnCs after NME reduced mortality by 50%, reduced expression of inflammatory proteins in serum and tissue and improved the immune response. This was confirmed with a second senolytic regimen, Dasatinib plus Quercetin, as well as genetic ablation of SnCs in aged mice, establishing SnCs as a cause of adverse outcomes in aged organisms exposed to a new viral pathogen.
CONCLUSION
SnCs amplify susceptibility to COVID-19 and pathogen-induced hyperinflammation. Reducing SnC burden in aged mice reduces mortality after pathogen exposure, including a β-coronavirus. Our findings strongly support the Geroscience hypothesis that therapeutically targeting fundamental aging mechanisms improves resilience in the elderly, with alleviation of morbidity and mortality due to pathogenic stress. This suggests that senolytics might protect others vulnerable to adverse COVID-19 outcomes in whom increased SnCs occur (such as in obesity or numerous chronic diseases).
SnCs that accumulate with age or chronic disease react to PAMPs such as SARS-CoV-2 S1 by amplifying the SASP, which increases viral entry protein expression and decreases viral defense IFITMs in normal cells.
Old mice exposed to pathogens such as the β-coronavirus MHV have increased inflammation and higher mortality. Treatment with a senolytic decreased SnCs, inflammation, and mortality and increased the antiviral antibody response.
The COVID-19 pandemic has revealed the pronounced vulnerability of the elderly and chronically ill to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–induced morbidity and mortality. Cellular senescence contributes to inflammation, multiple chronic diseases, and age-related dysfunction, but effects on responses to viral infection are unclear. Here, we demonstrate that senescent cells (SnCs) become hyper-inflammatory in response to pathogen-associated molecular patterns (PAMPs), including SARS-CoV-2 spike protein-1, increasing expression of viral entry proteins and reducing antiviral gene expression in non-SnCs through a paracrine mechanism. Old mice acutely infected with pathogens that included a SARS-CoV-2–related mouse β-coronavirus experienced increased senescence and inflammation, with nearly 100% mortality. Targeting SnCs by using senolytic drugs before or after pathogen exposure significantly reduced mortality, cellular senescence, and inflammatory markers and increased antiviral antibodies. Thus, reducing the SnC burden in diseased or aged individuals should enhance resilience and reduce mortality after viral infection, including that of SARS-CoV-2.
Understanding the molecular events controlling melanoma progression is of paramount importance for the development of alternative treatment options for this devastating disease. Here we report a ...mechanism regulated by the oncogenic SOX2-GLI1 transcriptional complex driving melanoma invasion through the induction of the sialyltransferase ST3GAL1. Using in vitro and in vivo studies, we demonstrate that ST3GAL1 drives melanoma metastasis. Silencing of this enzyme suppresses melanoma invasion and significantly reduces the ability of aggressive melanoma cells to enter the blood stream, colonize distal organs, seed and survive in the metastatic environment. Analysis of glycosylated proteins reveals that the receptor tyrosine kinase AXL is a major effector of ST3GAL1 pro-invasive function. ST3GAL1 induces AXL dimerization and activation that, in turn, promotes melanoma invasion. Our data support a key role of the ST3GAL1-AXL axis as driver of melanoma metastasis, and highlight the therapeutic potential of targeting this axis to treat metastatic melanoma.
The objective of the study was to explore the disease pathways activated in the inflammatory foci of skin lesions in cutaneous lupus erythematosus (CLE) and dermatomyositis (DM).
Skin biopsies ...acquired from active CLE and DM lesions, patient (PC), and also healthy controls (HC) were investigated. Biopsy sections were examined by a pathologist, inflammatory foci were laser micro-dissected and captured, and proteins within captured tissue were detected in an unbiased manner by mass spectrometry. Protein pathway analysis was performed by the string-db.org platform. Findings of interest were confirmed by immunohistochemistry (IHC).
Proteome investigation identified abundant expression of interferon-regulated proteins (IRP) as a common feature of CLE and DM. Interleukin (IL)-16 was the only abundant cytokine differentially expressed in CLE compared to DM. Caspase-3, an enzyme that cleaves IL-16 into its active form, was detected in low levels. Significantly higher proportion of IL-16- and caspase-3-positive cells was identified in CLE lesions in comparison with DM, PC, and HC. Proteomic results indicate more abundant complement deposition in CLE skin lesions.
Using unbiased mass spectrometry investigation of CLE and DM inflammatory infiltrates, we confirmed that high IRP expression is a common feature of both CLE and DM, while IL-16 is the only differentially expressed cytokine in CLE. IHC confirmed high expression of IL-16 and caspase-3 in CLE. Our novel molecular findings indicate that IL-16 detection could be useful in differential diagnostics between the two conditions that can display similar histopathological appearance. IL-16 could be of interest as a future therapeutic target for CLE.
One of the greatest barriers to curative treatment of neuroblastoma is its frequent metastatic outgrowth prior to diagnosis, especially in cases driven by amplification of the
oncogene. However, only ...a limited number of regulatory proteins that contribute to this complex
-mediated process have been elucidated. Here we show that the
(
) gene, located at chromosome band 17p13.1, is preferentially deleted in high-risk MYCN-driven neuroblastoma.
expression was also suppressed in
-amplified neuroblastoma lacking 17p deletion.
deficiency led to accelerated metastasis in both zebrafish and mammalian models of neuroblastoma with overexpression or amplification of
. Analysis of expression profiles and the ultrastructure of zebrafish neuroblastoma tumors with
overexpression identified that
deficiency led to (i) downregulation of genes involved in cell-cell interaction, (ii) loss of contact among tumor cells as critical determinants of accelerated metastasis, and (iii) increased levels of MYCN protein. These results provide the first genetic evidence that
depletion is a critical early step in the cascade of events culminating in neuroblastoma metastasis in the context of
overexpression. SIGNIFICANCE: Heterozygous deletion or
-mediated repression of
in neuroblastoma releases an important brake on tumor cell dispersion and migration to distant sites, providing a novel mechanism underlying tumor metastasis in MYCN-driven neuroblastoma.
.
BackgroundMany investigators have explored pathways upregulated in SLE and CLE. Few reports studied key downregulated pathways and mediators. Using unbiased proteomic technique, we have previously ...identified IL-16 as a key cytokine in cutaneous lupus erythematosus (CLE), and findings were verified lupus nephritis.1 2 In this analysis we analysed the downregulated pathways in the same proteomic database.ObjectivesTo systematically identify patterns of protein expression in dermal infiltrates of skin lesions of patients with CLE in comparison to control skin, and explore what pathways might be downregulated or non-functional.MethodsSkin biopsies from 6 CLE patients and 6 controls were investigated as described before.2 Inflammatory infiltrates and control dermis were laser capture micro-dissected and run on nano-LC tandem mass spectrometry.Data was analysed by String and Qiagen Ingenuity pathway analysis (IPA). P-values<0.05 were considered significant, adjustment for multiple testing was performed.ResultsComparing CLE vs controls we identified 300 proteins that were upregulated in CLE, while 387 were downregulated.The IPA of the upregulated pathways was presented before,2 and include interferon, EIF2, hyper-cytokinemia, mitochondrial dysfunction, RHOGDI signalling, Th1 and Th2, granzyme A pathways.There were a high number of downregulated pathways, which included remodelling of epithelial adherent junctions, fatty acid a-oxidation, Sertoli-cell junction, GP6, apelin liver, wound healing, and a list of downregulated degradation pathways for tryptophan X, putrescine, dopamine, valine, histamine, noradrenaline and adrenaline, ethanol; followed by integrin and epithelial adherent junction signaling, oxidative phosphorylation, estrogen receptor and intrinsic phrothrombin activation. Overlapping among several pathways, components of respiratory chain (NADH dehydrogenase and multiple subcomponents), galectin 3 and 7, epidermal growth factor receptor (EGFR), interleukin-1 receptor antagonist protein (IL1RN) and integrin alpha 2 (ITGA2) were significantly downregulated, while for example ITGA beta 2 (ITGAB2) was strongly upregulated.2 ConclusionsComparative analysis of upregulated and downregulated pathways at the site of skin inflammation, have disclosed several key-components that are downregulated, possibly malfunctioning or dysbalanced in regulation of inflammation and tissue regeneration. This novel information may contribute to better understanding of disease molecular pathogenesis, and what pathways might be of interest for pharmaceutical targeting.AcknowledgementsKarolinska Institutet-Mayo Clinic collaboration fund, NCI Cancer Center Support Grant 5P30 CA15083–43C1, Signe och Reinhold Sunds fund and Margareta Nilsson foundation.DisclosuresTimothy Niewold: None declared; Alexander Meves: None declared; Julia Lehman: None declared; Karin Popovic-Silwerfeldt: None declared; Cristine Charlesworth: None declared; Benjamin Madden: None declared; Elisabet Svenungsson shareholder of: AstraZeneca, Pfizer, Speakers fee: Janssen, Grant/research support from: Merck; Vilija Oke Speakers fee: Novartis, Jansen, Astra Zeneca, UCB, Eli Lilly and Abbvie, Grant/research support from: Ono pharma.References Häyry A, Faustini F, Zickert A, et al. Interleukin (IL) 16: a candidate urinary biomarker for proliferative lupus nephritis. Lupus Sci Medicine 2022;9:e000744. Niewold TB, Meves A, Lehman JS, et al. Proteome study of cutaneous lupus erythematosus (CLE) and dermatomyositis skin lesions reveals IL-16 is differentially upregulated in CLE. Arthritis Res Ther 2021;23:132.
Focal adhesion kinase (FAK) is an intensely studied non-receptor tyrosine kinase with roles in cancer and other common human diseases. Despite the large interest in FAK, the in vivo contribution of ...FAK auto-phosphorylation site tyrosine (Y) 397 to FAK function is incompletely understood. To study FAK Y397 in vivo we analyzed mice with 'non-phosphorylatable' Y-to-phenylalanine (F) and 'phospho-mimicking' Y-to-glutamate (E) mutations in the germline. We found that FAK Y397F mice die early during embryogenesis with abnormal angiogenesis like FAK kinase-dead mice. When Y397 is mutated to a glutamate mice survive beyond mid-gestation like mice where Y397 is lost by deletion of FAK exon 15. In culture, defects in proliferation, invasion and gene expression were more severe with the FAK Y397F than with the FAK Y397E mutation despite the inability of FAK Y397E to bind SRC. Conditional expression of FAK Y397F or Y397E in unchallenged avascular epidermis, however, resulted in no appreciable phenotype. We conclude that FAK Y397 is required for the highly dynamic tissue remodeling during development but dispensable for normal homeostasis of avascular epidermis. In contrast to the Y397F mutation, FAK Y397E retains sufficient biological activity to allow for development beyond mid-gestation.
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Growing evidence suggests a major role for Src-homology-2-domain-containing phosphatase 2 (SHP2/PTPN11) in MYCN-driven high-risk neuroblastoma, although biologic confirmation and a plausible ...mechanism for this contribution are lacking. Using a zebrafish model of MYCN-overexpressing neuroblastoma, we demonstrate that mutant ptpn11 expression in the adrenal gland analog of MYCN transgenic fish promotes the proliferation of hyperplastic neuroblasts, accelerates neuroblastomagenesis, and increases tumor penetrance. We identify a similar mechanism in tumors with wild-type ptpn11 and dysregulated Gab2, which encodes a Shp2 activator that is overexpressed in human neuroblastomas. In MYCN transgenic fish, Gab2 overexpression activated the Shp2-Ras-Erk pathway, enhanced neuroblastoma induction, and increased tumor penetrance. We conclude that MYCN cooperates with either GAB2-activated or mutant SHP2 in human neuroblastomagenesis. Our findings further suggest that combined inhibition of MYCN and the SHP2-RAS-ERK pathway could provide effective targeted therapy for high-risk neuroblastoma patients with MYCN amplification and aberrant SHP2 activation.
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•Activated Shp2 cooperates with MYCN to promote neuroblastomagenesis•Shp2 can be activated by overexpressed Gab2 in MYCN-driven neuroblastoma•Gab2 overexpression also activates the Ras-Erk pathway in neuroblastoma•Combined inhibition of MYCN and Mek-Erk signaling inhibits neuroblastoma cell growth
Sequencing studies have identified few recurrent mutations in neuroblastomas. Zhang et al. uncover a non-mutational mechanism that enhances high-risk neuroblastomagenesis: aberrant SHP2 activation through overexpression of its upstream regulator, GAB2. Combined inhibition of MYCN and the GAB2-Shp2-Mek pathway may provide an avenue for improved targeted therapy of neuroblastoma.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
β1 integrin tyrosine phosphorylation by oncogenic kinases, such as S re, has been predicted to induce tumorigenesis by disrupting adhesion and modifying integrin signaling. We directly tested this ...hypothesis by subjecting mice with "nonphosphorylatable" tyrosineto-phenylalanine substitutions in the conserved β1 cytoplasmic tail NPxY motifs to a model of cutaneous carcinogenesis in the presence or absence of elevated Src activity. We found that hydrophobic phenylalanine substitutions of both tyrosines diminished the binding of tail-interacting proteins, including talins and kindlins, resulting in reduced β1-mediated adhesion, focal adhesion kinase (FAK) signaling, and epidermal progenitor cell-derived skin tumors. However, increased Src activity drove tumor formation independent of the phenylalanine substitutions by enhancing FAK activity, which in turn maintained the epidermal progenitor state and blocked keratinocyte differentiation. We conclude that a Src/FAK signaling unit inhibits differentiation to promote tumorigenesis downstream of β1 integrin and independent of β1 integrin tyrosine phosphorylation.
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