scholarly journals A role of hypoxia inducible factor 1 alpha in Mouse Gammaherpesvirus 68 (MHV68) lytic replication and reactivation from latency

2019 ◽  
Author(s):  
Darlah M. López-Rodríguez ◽  
Varvara Kirillov ◽  
Laurie T. Krug ◽  
Enrique A. Mesri ◽  
Samita Andreansky
Keyword(s):  
Oxygen Sensing ◽  
Acute Infection ◽  
Hypoxia Inducible Factor ◽  
Virus Production ◽  
Laboratory Mice ◽  
Hypoxia Inducible Factor 1 ◽  
Lytic Reactivation ◽  
Gammaherpesvirus 68

ABSTRACTThe hypoxia inducible factor 1 alpha (HIFIα) protein and the hypoxic microenvironment are critical for infection and pathogenesis by the oncogenic gammaherpesviruses (γHV) such as Kaposi’ Sarcoma-associated Herpes Virus (KSHV) and Epstein-Barr virus (EBV). However, understanding the role of HIFIα during the virus life cycle and its biological relevance in the context of host pathogenesis has been challenging due to the lack of animal models for human γHV. To study the role of HIFIα we employed the murine gammaherpesvirus 68 (MHV68), a rodent pathogen that readily infects laboratory mice. We show that MHV68 infection induces HIFIα protein and HIFIα-responsive gene expression in permissive cells. Deletion of HIFIα reduces virus production due to a global downregulation of viral gene expression. Most notable was the marked decrease in many viral genes bearing hypoxia regulatory element (HRE) such as viral G-Protein Coupled Receptor (vGPCR), which is known to activate HIF1α transcriptional activity during KSHV infection. Intranasal infection of HIF1αLoxP/LoxP mice with MHV68 expressing Cre-recombinase impaired virus expansion during early acute infection and affected lytic reactivation in the splenocytes explanted from mice. Moreover, low oxygen conditions accelerated lytic reactivation and enhanced virus production in MHV68 infected splenocytes. Thus, we conclude that HIFIα plays a critical role to promote virus replication. Our results highlight the importance of the mutual interactions of the oxygen-sensing machinery and gammaherpesviruses in viral replication and pathogenesis.AUTHOR SUMMARYThe host oxygen sensing machinery including the HIF1α pathway is important during the viral life cycle of oncogenic gammaherpesviruses such as KSHV and EBV. However, due to the host specificity, the effects of HIF1α in herpes biology is limited to studies with in vitro systems. Here, we study the role of HIF1α using the mouse gammaherpesvirus 68 (MHV68) that readily infects laboratory mice. We demonstrate that MHV68 infection upregulates HIF1α during replication and inactivation of HIF1α transcriptional activity significantly decreased viral genes expression which results in impaired virus production in vitro. In vivo deletion of HIF1α impaired viral expansion during acute infection and affected reactivation from latency. These results show the importance of the interplay with the oxygen-sensing machinery in gammaherpesvirus infection and pathogenesis, placing the MHV68 mouse model as a unique platform to gain insight into this important aspect of oncogenic gamma-herpesviruses biology and to test HIF1α targeted therapeutics.

scholarly journals Normoxic Tumour Extracellular Vesicles Modulate the Response of Hypoxic Cancer and Stromal Cells to Doxorubicin In Vitro

2020 ◽  
Vol 21 (17) ◽  
pp. 5951
Author(s):  
Laura Patras ◽  
Marcel H. A. M. Fens ◽  
Pieter Vader ◽  
Arjan Barendrecht ◽  
Alina Sesarman ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Extracellular Vesicles ◽  
Hypoxia Inducible Factor ◽  
B Cell Lymphoma ◽  
Tumour Microenvironment ◽  
Hypoxia Inducible Factor 1 ◽  
Apoptotic Protein ◽  
Donor Cells

Extracellular vesicles (EV) secreted in the tumour microenvironment (TME) are emerging as major antagonists of anticancer therapies by orchestrating the therapeutic outcome through altering the behaviour of recipient cells. Recent evidence suggested that chemotherapeutic drugs could be responsible for the EV-mediated tumour–stroma crosstalk associated with cancer cell drug resistance. Here, we investigated the capacity of tumour EV (TEV) secreted by normoxic and hypoxic (1% oxygen) C26 cancer cells after doxorubicin (DOX) treatment to alter the response of naïve C26 cells and RAW 264.7 macrophages to DOX. We observed that C26 cells were less responsive to DOX treatment under normoxia compared to hypoxia, and a minimally cytotoxic DOX concentration that mounted distinct effects on cell viability was selected for TEV harvesting. Homotypic and heterotypic pretreatment of naïve hypoxic cancer and macrophage-like cells with normoxic DOX-elicited TEV rendered these cells slightly less responsive to DOX treatment. The observed effects were associated with strong hypoxia-inducible factor 1-alpha (HIF-1α) induction and B-cell lymphoma–extra-large anti-apoptotic protein (Bcl-xL)-mediated anti-apoptotic response in normoxic DOX-treated TEV donor cells, being also tightly connected to the DOX-TEV-mediated HIF-1α induction, as well as Bcl-xL levels increasing in recipient cells. Altogether, our results could open new perspectives for investigating the role of chemotherapy-elicited TEV in the colorectal cancer TME and their modulatory actions on promoting drug resistance.

scholarly journals A role of hypoxia-inducible factor 1 alpha in Murine Gammaherpesvirus 68 (MHV68) lytic replication and reactivation from latency

2019 ◽  
Vol 15 (12) ◽  
pp. e1008192 ◽  
Author(s):  
Darlah M. López-Rodríguez ◽  
Varvara Kirillov ◽  
Laurie T. Krug ◽  
Enrique A. Mesri ◽  
Samita Andreansky
Keyword(s):  
Hypoxia Inducible Factor ◽  
Lytic Replication ◽  
Murine Gammaherpesvirus ◽  
Hypoxia Inducible Factor 1 ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

scholarly journals Exploiting the Role of Hypoxia-Inducible Factor 1 and Pseudohypoxia in the Myelodysplastic Syndrome Pathophysiology

2021 ◽  
Vol 22 (8) ◽  
pp. 4099
Author(s):  
Ioanna E. Stergiou ◽  
Konstantinos Kambas ◽  
Aikaterini Poulaki ◽  
Stavroula Giannouli ◽  
Theodora Katsila ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Hypoxia Inducible Factor ◽  
Aberrant Expression ◽  
Myeloid Lineage ◽  
Hematopoietic Stem ◽  
Transcription Activity ◽  
Hypoxia Inducible Factor 1 ◽  
Abnormal Mitochondria

Myelodysplastic syndromes (MDS) comprise a heterogeneous group of clonal hematopoietic stem (HSCs) and/or progenitor cells disorders. The established dependence of MDS progenitors on the hypoxic bone marrow (BM) microenvironment turned scientific interests to the transcription factor hypoxia-inducible factor 1 (HIF-1). HIF-1 facilitates quiescence maintenance and regulates differentiation by manipulating HSCs metabolism, being thus an appealing research target. Therefore, we examine the aberrant HIF-1 stabilization in BMs from MDS patients and controls (CTRLs). Using a nitroimidazole–indocyanine conjugate, we show that HIF-1 aberrant expression and transcription activity is oxygen independent, establishing the phenomenon of pseudohypoxia in MDS BM. Next, we examine mitochondrial quality and quantity along with levels of autophagy in the differentiating myeloid lineage isolated from fresh BM MDS and CTRL aspirates given that both phenomena are HIF-1 dependent. We show that the mitophagy of abnormal mitochondria and autophagic death are prominently featured in the MDS myeloid lineage, their severity increasing with intra-BM blast counts. Finally, we use in vitro cultured CD34+ HSCs isolated from fresh human BM aspirates to manipulate HIF-1 expression and examine its potential as a therapeutic target. We find that despite being cultured under 21% FiO2, HIF-1 remained aberrantly stable in all MDS cultures. Inhibition of the HIF-1α subunit had a variable beneficial effect in all <5%-intra-BM blasts-MDS, while it had no effect in CTRLs or in ≥5%-intra-BM blasts-MDS that uniformly died within 3 days of culture. We conclude that HIF-1 and pseudohypoxia are prominently featured in MDS pathobiology, and their manipulation has some potential in the therapeutics of benign MDS.

n-Propyl gallate activates hypoxia-inducible factor 1 by modulating intracellular oxygen-sensing systems

2008 ◽  
Vol 411 (1) ◽  
pp. 97-105 ◽  
Author(s):  
Motohide Kimura ◽  
Satoshi Takabuchi ◽  
Tomoharu Tanaka ◽  
Miyahiko Murata ◽  
Kenichiro Nishi ◽  
...  
Keyword(s):  
Propyl Gallate ◽  
Transcriptional Activity ◽  
Target Genes ◽  
Cultured Cells ◽  
Oxygen Sensing ◽  
Hypoxia Inducible Factor ◽  
Downstream Target ◽  
Hypoxia Inducible Factor 1

HIF-1 (hypoxia-inducible factor 1) is a master regulator of cellular adaptive responses to hypoxia. The expression and transcriptional activity of the HIF-1α subunit is stringently controlled by intracellular oxygen tension through the action of prolyl and asparaginyl hydroxylases. In the present study we demonstrate that PG (n-propyl gallate) activates HIF-1 and expression of its downstream target genes under normoxic conditions in cultured cells and in mice. The stability and transcriptional activity of HIF-1α are increased by PG. PG treatment inhibits the interaction between HIF-1α and VHL (von Hippel–Lindau protein) and promotes the interaction between HIF-1α and p300, indicating that PG inhibits the activity of both prolyl and asparaginyl HIF-1α hydroxylases. We conclude that PG activates HIF-1 and enhances the resultant gene expression by directly affecting the intracellular oxygen sensing system in vitro and in vivo and that PG represents a lead compound for the development of a non-toxic activator of HIF-1.

scholarly journals A Gammaherpesvirus Ubiquitin-Specific Protease Is Involved in the Establishment of Murine Gammaherpesvirus 68 Infection

2009 ◽  
Vol 83 (20) ◽  
pp. 10644-10652 ◽  
Author(s):  
Sara Gredmark-Russ ◽  
Marisa K. Isaacson ◽  
Lisa Kattenhorn ◽  
Evelyn J. Cheung ◽  
Nicki Watson ◽  
...  
Keyword(s):  
Acute Infection ◽  
Mutant Virus ◽  
Tegument Protein ◽  
Murine Gammaherpesvirus ◽  
Enzymatic Function ◽  
Significant Difference ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT Murine gammaherpesvirus 68 (MHV-68) contains a ubiquitin (Ub)-specific cysteine protease (USP) domain embedded within the large tegument protein ORF64, as do all other herpesviruses. The biological role of this protease is still unclear, but for the alphaherpesvirus Marek's disease virus, its USP is involved in T-cell lymphoma formation. We here study the role of the MHV-68 USP, encoded by ORF64. By constructing a mutant virus with a single cysteine-to-alanine replacement in the active site of ORF64, we demonstrate that the USP activity of ORF64 is abolished. The mutant virus replicates less efficiently in vitro, and plaque size is reduced compared to that of a revertant virus. Electron microscopy of infected cells did not reveal any obvious differences in virion morphogenesis or differences in egress for the mutant and revertant viruses. Intraperitoneal infection of C57/BL6 mice demonstrates that the mutant virus is generally cleared by day 7, indicating a role for the USP in the persistence of MHV-68 infection or efficient replication. However, the USP activity in MHV-68 is unlikely to be involved in the establishment of latency or reactivation, since we observed no significant difference in viral DNA genome copy number in the spleen or in the number of cells that reactivate MHV-68 from latency. Our results for MHV-68 ORF64 are consistent with an enzymatic function of the tegument protein that is beneficial to the virus during acute infection, particularly in vivo.

scholarly journals The Role of Hypoxia-Inducible Factor 1 in Mild Cognitive Impairment

2016 ◽  
Vol 37 (6) ◽  
pp. 969-977 ◽  
Author(s):  
Osigbemhe Iyalomhe ◽  
Sabina Swierczek ◽  
Ngozi Enwerem ◽  
Yuanxiu Chen ◽  
Monica O. Adedeji ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1

scholarly journals Hypoxia-inducible factor–1 and associated upstream and downstream proteins in the pathophysiology and management of glioblastoma

2014 ◽  
Vol 37 (6) ◽  
pp. E8 ◽  
Author(s):  
Matthew Womeldorff ◽  
David Gillespie ◽  
Randy L. Jensen
Keyword(s):  
Cellular Response ◽  
Treatment Options ◽  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1 ◽  
Poor Patient ◽  
Growth Development ◽  
The Relationship ◽  
Insight Into ◽  
Upstream Regulators

Glioblastoma multiforme (GBM) is a highly aggressive brain tumor with an exceptionally poor patient outcome despite aggressive therapy including surgery, radiation, and chemotherapy. This aggressive phenotype may be associated with intratumoral hypoxia, which probably plays a key role in GBM tumor growth, development, and angiogenesis. A key regulator of cellular response to hypoxia is the protein hypoxia-inducible factor–1 (HIF-1). An examination of upstream hypoxic and nonhypoxic regulation of HIF-1 as well as a review of the downstream HIF-1–regulated proteins may provide further insight into the role of this transcription factor in GBM pathophysiology. Recent insights into upstream regulators that intimately interact with HIF-1 could provide potential therapeutic targets for treatment of this tumor. The same is potentially true for HIF-1–mediated pathways of glycolysis-, angiogenesis-, and invasion-promoting proteins. Thus, an understanding of the relationship between HIF-1, its upstream protein regulators, and its downstream transcribed genes in GBM pathogenesis could provide future treatment options for the care of patients with these tumors.

scholarly journals HIF-1α is a key mediator of the lung inflammatory potential of lithium-ion battery particles

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Violaine Sironval ◽  
Mihaly Palmai-Pallag ◽  
Rita Vanbever ◽  
François Huaux ◽  
Jorge Mejia ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Hypoxia Inducible Factor ◽  
Lithium Ion ◽  
In Vitro Assays ◽  
Inhalation Toxicity ◽  
Cobalt Nickel ◽  
Occupational Settings

Abstract Background Li-ion batteries (LIB) are increasingly used worldwide. They are made of low solubility micrometric particles, implying a potential for inhalation toxicity in occupational settings and possibly for consumers. LiCoO2 (LCO), one of the most used cathode material, induces inflammatory and fibrotic lung responses in mice. LCO also stabilizes hypoxia-inducible factor (HIF) -1α, a factor implicated in inflammation, fibrosis and carcinogenicity. Here, we investigated the role of cobalt, nickel and HIF-1α as determinants of toxicity, and evaluated their predictive value for the lung toxicity of LIB particles in in vitro assays. Results By testing a set of 5 selected LIB particles (LCO, LiNiMnCoO2, LiNiCoAlO2) with different cobalt and nickel contents, we found a positive correlation between their in vivo lung inflammatory activity, and (i) Co and Ni particle content and their bioaccessibility and (ii) the stabilization of HIF-1α in the lung. Inhibition of HIF-1α with chetomin or PX-478 blunted the lung inflammatory response to LCO in mice. In IL-1β deficient mice, HIF-1α was the upstream signal of the inflammatory lung response to LCO. In vitro, the level of HIF-1α stabilization induced by LIB particles in BEAS-2B cells correlated with the intensity of lung inflammation induced by the same particles in vivo. Conclusions We conclude that HIF-1α, stabilized in lung cells by released Co and Ni ions, is a mechanism-based biomarker of lung inflammatory responses induced by LIB particles containing Co/Ni. Documenting the Co/Ni content of LIB particles, their bioaccessibility and their capacity to stabilize HIF-1α in vitro can be used to predict the lung inflammatory potential of LIB particles.

scholarly journals HIF-1α contributes to Ang II-induced inflammatory cytokine production in podocytes

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Hao Huang ◽  
Yanqin Fan ◽  
Zhao Gao ◽  
Wei Wang ◽  
Ning Shao ◽  
...  
Keyword(s):  
Hypoxia Inducible Factor ◽  
Renin Angiotensin System ◽  
Inflammatory Factors ◽  
Ang Ii ◽  
Angiotensin System ◽  
Inflammatory Injury ◽  
Tnf Α

Abstract Background Studies have indicated that changed expression of hypoxia-inducible factor-1α (HIF-1α) in epithelial cells from the kidney could affect the renal function in chronic kidney disease (CKD). As Angiotensin II (Ang II) is a critical active effector in the renin-angiotensin system (RAS) and was proved to be closely related to the inflammatory injury. Meanwhile, researchers found that Ang II could alter the expression of HIF-1α in the kidney. However, whether HIF-1α is involved in mediating Ang II-induced inflammatory injury in podocytes is not clear. Methods Ang II perfusion animal model were established to assess the potential role of HIF-1α in renal injury in vivo. Ang II stimulated podocytes to observe the corresponding between HIF-1α and inflammatory factors in vitro. Results The expression of inflammatory cytokines such as MCP-1 and TNF-α was increased in the glomeruli from rats treated with Ang II infusion compared with control rats. Increased HIF-1α expression in the glomeruli was also observed in Ang II-infused rats. In vitro, Ang II upregulated the expression of HIF-1α in podocytes. Furthermore, knockdown of HIF-1α by siRNA decreased the expression of MCP-1 and TNF-α. Moreover, HIF-1α siRNA significantly diminished the Ang II-induced overexpression of HIF-1α. Conclusion Collectively, our results suggest that HIF-1α participates in the inflammatory response process caused by Ang II and that downregulation of HIF-1α may be able to partially protect or reverse inflammatory injury in podocytes.

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