HIV-1 enhances mTORC1 activity and repositions lysosomes to the periphery by co-opting Rag GTPases

Cinti, Alessandro; Sage, Valerie Le; Milev, Miroslav P.; Valiente-Echeverría, Fernando; Crossie, Christina; Miron, Marie-Joëlle; Panté, Nelly; Olivier, Martin; Mouland, Andrew J.

doi:10.1038/s41598-017-05410-0

Cited by 34 publications

(34 citation statements)

References 67 publications

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“…TFEB modulates lysosomal exocytosis, and de-acidification of lysosomes located at the cell periphery is thought to contribute to this process (Medina et al 2011; Sbano et al 2017). A recent study found that HIV infection relocates lysosomes to the periphery of macrophages (Cinti et al 2017). Lysosomes located at the cell periphery lose their luminal acidity and proteolytic activity, and their principal role is to fuse with the plasma membrane and promote their exocytosis in a calcium-dependent manner (Xu & Ren 2015; Johnson et al 2016).…”

Section: Discussionmentioning

confidence: 99%

Dimethyl Fumarate Prevents HIV-Induced Lysosomal Dysfunction and Cathepsin B Release from Macrophages

Rosario-Rodríguez

Colón

Borges-Vélez

et al. 2018

J Neuroimmune Pharmacol

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HIV-associated neurocognitive disorders (HAND) are prevalent despite combined antiretroviral therapy, affecting nearly half of HIV-infected patients worldwide. During HIV infection of macrophages secretion of the lysosomal protein, cathepsin B, is increased. Secreted cathepsin B has been shown to induce neurotoxicity. Oxidative stress is increased in HIV-infected patients, while antioxidants are decreased in monocytes from patients with HIV-associated dementia (HAD). Dimethyl fumarate (DMF), an antioxidant, has been reported to decrease HIV replication and neurotoxicity mediated by HIV-infected macrophages. Thus, we hypothesized that DMF will decrease cathepsin B release from HIV-infected macrophages by preventing oxidative stress and enhancing lysosomal function. Monocyte-derived macrophages (MDM) were isolated from healthy donors, inoculated with HIV-1 and treated with DMF following virus removal. After 12 days post-infection, HIV-1 p24 and total cathepsin B levels were measured from HIV-infected MDM supernatants using ELISA; intracellular reactive oxygen and nitrogen species (ROS/RNS) were measured from MDM lysates, and functional lysosomes were assessed using a pH-dependent lysosomal dye. Neurons were incubated with serum-free conditioned media from DMF-treated MDM and neurotoxicity was determined using TUNEL assay. Results indicate that DMF reduced HIV-1 replication and cathepsin B secretion from HIV-infected macrophages in a dose-dependent manner. Also, DMF decreased intracellular ROS/RNS levels, and prevented HIV-induced lysosomal dysfunction and neuronal apoptosis. In conclusion, the improvement in lysosomal function with DMF treatment may represent the possible mechanism to reduce HIV-1 replication and cathepsin B secretion. DMF represents a potential therapeutic strategy against HAND.

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Section: Discussionmentioning

confidence: 99%

Dimethyl Fumarate Prevents HIV-Induced Lysosomal Dysfunction and Cathepsin B Release from Macrophages

Rosario-Rodríguez

Colón

Borges-Vélez

et al. 2018

J Neuroimmune Pharmacol

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“…For siRNA transfection, 20 nM of siRNA was used to transfect 150,000 cells using Lipofectamine 2000 (Invitrogen) reagent according to manufacturer's instructions. Cells were treated with 500 mM arsenite (Sigma-Aldrich) for 1 h and with 1 µM Emetine (Sigma-Aldrich) for 50 min (Cinti et al 2017). siRNAs siRNA duplexes were purchased from QIAGEN-Xeragon.…”

Section: Cell Culture and Transfection Conditionsmentioning

confidence: 99%

“…Protein synthesis during NC expression was measured by the incorporation of puromycin into peptide chains (Schmidt et al 2009;Goodman et al 2011;Cinti et al 2017). Briefly, pCMV NC-RLuc, pCMV NC-RLuc + pCMV Staufen1-YFP, and pCMV-RLuc transfected HeLa cells were incubated with 10 µg/mL puromycin (MilliporeSigma) for 10 min before cell lysis.…”

Section: Measurement Of Protein Synthesismentioning

confidence: 99%

“…Briefly, pCMV NC-RLuc, pCMV NC-RLuc + pCMV Staufen1-YFP, and pCMV-RLuc transfected HeLa cells were incubated with 10 µg/mL puromycin (MilliporeSigma) for 10 min before cell lysis. Cell extracts were blotted with anti-Puromycin antibody (12D10, MilliporeSigma) and puromycin incorporation was assessed by summating the immunoblot intensity of all protein bands and subtracting background (Cinti et al 2017).…”

Section: Measurement Of Protein Synthesismentioning

confidence: 99%

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HIV-1 NC-induced stress granule assembly and translation arrest are inhibited by the dsRNA binding protein Staufen1

Rao

Cinti

Temzi

et al. 2017

RNA

Self Cite

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The nucleocapsid (NC) is an N-terminal protein derived from the HIV-1 Gag precursor polyprotein, pr55 NC possesses key functions at several pivotal stages of viral replication. For example, an interaction between NC and the host double-stranded RNA-binding protein Staufen1 was shown to regulate several steps in the viral replication cycle, such as Gag multimerization and genomic RNA encapsidation. In this work, we observed that the overexpression of NC leads to the induction of stress granule (SG) assembly. NC-mediated SG assembly was unique as it was resistant to the SG blockade imposed by the HIV-1 capsid (CA), as shown in earlier work. NC also reduced host cell mRNA translation, as judged by a puromycylation assay of de novo synthesized proteins, and this was recapitulated in polysome profile analyses. Virus production was also found to be significantly reduced. Finally, Staufen1 expression completely rescued the blockade to NC-mediated SG assembly, global mRNA translation as well as virus production. NC expression also resulted in the phosphorylation of protein kinase R (PKR) and eIF2α, and this was inhibited with Staufen1 coexpression. This work sheds light on an unexpected function of NC in host cell translation. A comprehensive understanding of the molecular mechanisms by which a fine balance of the HIV-1 structural proteins NC and CA act in concert with host proteins such as Staufen1 to modulate the host stress response will aid in the development of new antiviral therapeutics.

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“…On the contrary, starvation causes the perinuclear clustering of lysosomes and enhances autophagic flux via inhibition of mTORC1 activity [49,50]. In HeLa cells, HIV-1 counteracts metabolic and environmental stress-induced intracellular repositioning of lysosomes through enhancement of mTORC1 activity [51]. In another study, knockdown of FUT1 has been found to elevate the peripheral distribution of lysosomes by inhibition of mTORC1 activity, leading to the enhancement of autophagic flux [52].…”

Section: Autophagic Fluxmentioning

confidence: 99%

Podocyte Lysosome Dysfunction in Chronic Glomerular Diseases

Kidd

2020

IJMS

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Podocytes are visceral epithelial cells covering the outer surface of glomerular capillaries in the kidney. Blood is filtered through the slit diaphragm of podocytes to form urine. The functional and structural integrity of podocytes is essential for the normal function of the kidney. As a membrane-bound organelle, lysosomes are responsible for the degradation of molecules via hydrolytic enzymes. In addition to its degradative properties, recent studies have revealed that lysosomes may serve as a platform mediating cellular signaling in different types of cells. In the last decade, increasing evidence has revealed that the normal function of the lysosome is important for the maintenance of podocyte homeostasis. Podocytes have no ability to proliferate under most pathological conditions; therefore, lysosome-dependent autophagic flux is critical for podocyte survival. In addition, new insights into the pathogenic role of lysosome and associated signaling in podocyte injury and chronic kidney disease have recently emerged. Targeting lysosomal functions or signaling pathways are considered potential therapeutic strategies for some chronic glomerular diseases. This review briefly summarizes current evidence demonstrating the regulation of lysosomal function and signaling mechanisms as well as the canonical and noncanonical roles of podocyte lysosome dysfunction in the development of chronic glomerular diseases and associated therapeutic strategies.

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HIV-1 enhances mTORC1 activity and repositions lysosomes to the periphery by co-opting Rag GTPases

Cited by 34 publications

References 67 publications

Dimethyl Fumarate Prevents HIV-Induced Lysosomal Dysfunction and Cathepsin B Release from Macrophages

Dimethyl Fumarate Prevents HIV-Induced Lysosomal Dysfunction and Cathepsin B Release from Macrophages

HIV-1 NC-induced stress granule assembly and translation arrest are inhibited by the dsRNA binding protein Staufen1

Podocyte Lysosome Dysfunction in Chronic Glomerular Diseases

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