Notes and References for "Exciting New Discovery in Chronic Fatigue Syndrome"

(Original article here.)

¹Mathieu Blanc, Wei Yuan Hsieh, Kevin A. Robertson, Steven Watterson, Guanghou Shui, Paul Lacaze, Mizanur Khondoker, Paul Dickinson, Garwin Sing, Sara Rodríguez-Martín, Peter Phelan, Thorsten Forster, Birgit Strobl, Matthias Müller, Rudolph Riemersma, Timothy Osborne, Markus R. Wenk, Ana Angulo, Peter Ghazal. Host Defense against Viral Infection Involves Interferon Mediated Down-Regulation of Sterol Biosynthesis. PLoS Biology, 2011; 9 (3): e1000598 DOI: 10.1371/journal.pbio.1000598. See full study.

²Science Daily article "Curbing Cholesterol Could Help Combat Infections, Study Shows"

³DM, Tilles JG. Alpha-Interferon treatment of patients with chronic fatigue syndrome. Immunol Invest. 1996 Jan-Mar;25(1-2):153-64. Interferon Rx helped raise NK activity in CFS, but only increased QOL in those with low NK activity but normal lymphocyte proliferation to mitogens and soluble antigens Immunol Invest. 1996 Jan-Mar; 25(1-2):153-64.)

⁴Russell IJ, et al. Reduction of morning stiffness and improvement in physical function in fibromyalgia Syndrome patients treated sublingually with low doses of human interferon-alpha. J Interferon Cytokine Res. 1999 Aug;19(8):961-8. Full abstract.

⁵Masaike Y, et al. Identification of Dynamin-2-Mediated Endocytosis as a New Target of Osteoporosis Drugs, Bisphosphonates Mol Pharmacol 77:262–269, 2010. Full text of study (good discussion of the antiviral pathways involved)

⁶Br J Cancer. 2005 May 9; 92(9): 1593-1598. Published online 2005 April 26. doi: 10.1038/sj.bjc.6602561. PMCID: PMC2362042. HMG CoA reductase inhibitors (statins) to treat Epstein–Barr virus-driven lymphoma.

Abstract: HMG CoA reductase inhibitors (statins) to treat Epstein–Barr virus-driven lymphoma

While statins have been highly effective for lowering serum cholesterol and reducing the incidence of coronary events, they have multiple other effects. Certain statins block the interaction of adhesion molecules that are important for cell–cell interactions including those between EBV-transformed B cells. These same statins inhibit NF-κB activation in the cells and induce apoptosis of transformed B cells.

Studies in severe combined immunodeficiency mice show that simvastatin delays the development of EBV-lymphomas in these animals. These statins might be considered for the treatment of EBV-lymphomas in selected patients.

Statins inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. Six of these compounds, atorvastatin, fluvastatin, lovastatin, pravastatin, rosuvastatin, and simvastatin, are approved by the FDA for use in humans. Each of these compounds is used to treat elevated serum cholesterol. HMG-CoA reductase catalyses the conversion of HMG-CoA to mevalonate, which ultimately leads to synthesis of cholesterol. Therefore, statins reduce the level of mevalonate with a subsequent reduction in cholesterol.

Statins have a number of other activities related to their inhibition of HMG-CoA reductase (reviewed in Raggatt and Partridge, 2002). Mevalonate is a precursor for isoprenoids, including geranyl pyrophosphate and farnesyl pyrophosphate. Statins reduce the levels of these compounds. Post-translational modification of proteins by farnesylation or geranylgeranylation results in their association with cell membranes and activation (reviewed in Bellosta et al, 2000). These modified proteins include members of the nuclear laminin family, ras, inositol triphosphate 5-phosphatase, which are farnesylated, and Rho, Rac, cdc42, Rab, Rap, and G-proteins, which are geranylgeranylated. These changes have pleotrophic effects including inhibition of smooth muscle proliferation (Corsini et al, 1993), inhibition of MHC class II complexes on antigen-presenting cells (Kwak et al, 2000), increase in bone morphogenetic protein (Mundy et al, 1999), suppression of T- and B-cell responses (Kurakata et al, 1996), reduced NK cell activity (Hillyard et al, 2004), reduced synthesis of chemokines (Waehre et al, 2003), and growth arrest of certain transformed cells (Graaf et al, 2004). These effects can be reversed with the addition of mevalonate.

Certain statins have activities that are unrelated to their inhibition of HMG-CoA reductase. Kallen et al (1999) showed that lovastatin binds to the I-domain of LFA-1 and blocks its interaction with ICAM-1. LFA-1 (αLβ2 integrin) is an adhesion molecule that promotes diapedesis of leucocytes across the endothelium and is a costimulatory molecule on activated T cells. The I-domain of LFA-1 is separate from the site of its binding to its ligand ICAM-1. Weitz-Schmidt et al (2001) subsequently showed that simvastatin, mevastatin as well as lovastatin (but not pravastatin) can bind to LFA-1 and block its binding to ICAM-1. This interaction is independent of HMG-CoA and is not reversed by mevalonate. Simvastatin and lovastatin concentrations of ∼10 μM are required to block these interactions; this is in contrast to the nanomolar concentrations required to inhibit HMG-CoA. A synthetic statin (LFA703) which lacks HMGCoA reductase inhibitory activity, but which has increased LFA-1 binding activity, blocks LFA-1-induced costimulation of T cells and suppresses the inflammatory response to thioglycollate in a mouse model of peritonitis.

Statins have been shown to affect replication of HIV. HIV virions have ICAM-1 on their surface, which can bind to LFA-1 on target cells and enhance virus attachment (Fortin et al, 1997). Lovastatin inhibits replication of HIV by inhibiting the interaction of ICAM-1 on virions with LFA-1 on the surface of target cells (Giguere and Tremblay, 2004). Lovastatin inhibits HIV-induced Rho GTPase activation, which is important for HIV infection of cells (del Real et al, 2004). Entry into and exit from HIV-infected cells is blocked by lovastatin and this effect can be reversed by treatment with mevalonate. Treatment of HIV-infected severe combined immunodeficiency (SCID)-hu mice or humans with lovastatin results in a reduction in HIV RNA loads and increased CD4+ T-cell counts.

⁷This study showed the virus increased cholesterol production and shifted this to make new virus. (For the more "Tech minded" here is more — otherwise skip to next paragraph: Manipulating cholesterol levels and altering concentrations of cellular geranylgeranylated proteins had a deleterious effect on virus replication. Depletion of the key cholesterol-synthesizing enzyme 3-hydroxy-methyglutaryl-CoA reductase drastically hampered virus replication. Significantly, virus-induced redistribution of cellular cholesterol downregulated the interferon-stimulated Jak-STAT antiviral signaling response to infection. This defect could be partially restored by exogenous addition of cholesterol, which increased the ability of infected cells to respond to interferon. We propose that, by manipulating cellular cholesterol, WNV utilizes the cellular response to cholesterol deficiency and dependence of antiviral signaling pathways on cholesterol-rich microdomains to facilitate viral replication and survival.)

Mackenzie JM, Khromykh AA, Parton RG. Cholesterol manipulation by West Nile virus perturbs the cellular immune response. Cell Host Microbe. 2007 Oct 11;2(4):229-39.

⁸Rotavirus is a non-enveloped virus that depends on cellular lipids for cell entry and associates with lipid rafts during assembly. However, the effects of cellular lipids on rotavirus assembly are still not fully understood. The present study analyzes the effects of lovastatin, an inhibitor of cholesterol biosynthesis, during rotavirus infection in MA104 cells with regard to viral growth and particle assembly… Following viral infection, a 2-log relative reduction of viral titers was observed in drug-treated cells, while viral mRNA levels in infected cells remained unaltered in both groups. Furthermore, the levels of some viral proteins in drug-treated cells were elevated. The observed discordance between the viral RNA and protein levels and the decrease in infectivity titers of viral progeny in the drug-treated cells suggested that the drug affects viral assembly, the viral proteins not being properly incorporated into virions. Transmission electron microscopic (TEM) analysis revealed that in drug-treated cells there was an increase in "empty-looking" rotavirus particles devoid of an electron-dense core as compared to the normal, electron-dense particles seen in untreated infected cells. The present study thus provides visual evidence of defective rotavirus particle assembly as a result of cholesterol depletion.

Mohan KV, Muller J, Atreya CD. Defective rotavirus particle assembly in lovastatin-treated MA104 cells. Arch Virol. 2008;153(12):2283-90. Epub 2008 Nov 22. PMID:19030953

⁹Biochem Biophys Res Commun. 2006 Aug 18;347(1):51-9. Epub 2006 Jun 27.Role of simvastatin and methyl-beta-cyclodextrin [corrected] on inhibition of poliovirus infection.Liu S, Rodriguez AV, Tosteson MT. Source: Department of Cell Biology, Harvard Medical School, Cambridge, MA 02116, USA.Erratum in Biochem Biophys Res Commun. 2006 Sep 29;348(3):1207.

Abstract: Role of simvastatin and methyl-beta-cyclodextrin [corrected] on inhibition of poliovirus infection

Cells exposed to simvastatin or to methyl-beta-cyclodextrin show reduced poliovirus infection, without alteration in virus binding or on the kinetics of genome entry, suggesting that the steps which are altered are those post uncoating and genome entry. Reduction of infection by cyclodextrin is reversed by increasing MOI whereas that produced by simvastatin treatment is not, suggesting that the effects on infection are not due to a reduction in cholesterol. The differences in the characteristics of inhibition can be explained by the differential effects of the compounds. Cyclodextrin inhibits the store-operated calcium channels, suggesting that reduction in infection is through translational inhibition. Simvastatin produces vesicles from internal membranes which cannot sustain viral RNA synthesis, reducing infection through reduced transcription. The results indicate that the impact on viral infection by the cholesterol-modifying agents is due to the cellular changes produced rather than due to disruption of the cholesterol-rich domains.

PMID: 16824485 [PubMed - indexed for MEDLINE]

¹⁰When different statins were tested,and simvastatin [Zocor] exhibit the strongest in vitro anti-hepatitis C activity, lovastatin[mevacor] and fluvastatin [Lescol] had moderate inhibitory effects, and pravastatin{pravachol] had NO antiviral effect (So the type and dose of statin are likely effective) (Delang L, Paeshuyse J, Vliegen I, Leyssen P, Obeid S, Durantel D, Zoulim F, Op de Beeck A, Neyts J. Statins potentiate the in vitro anti-hepatitis C virus activity of selective hepatitis C virus inhibitors and delay or prevent resistance development. Hepatology. 2009 Jul;50(1):6-16. In this study, A combination of statins with interferon-alpha (IFN-alpha) further increased activity. The authors' Conclusion: A combination of specific HCV inhibitors with statins may result in a more profound antiviral effect and may delay or prevent the development of resistance to such inhibitors.

¹¹Lescol up to 80 mg a day lowered Hepatitis C levels , but the effects were temporaryAm J Gastroenterol. 2008 Jun;103(6):1383-9. Epub 2008 Apr 14.Fluvastatin inhibits hepatitis C replication in humans.Bader T, Fazili J, Madhoun M, Aston C, Hughes D, Rizvi S, Seres K, Hasan M.

Abstract: Fluvastatin inhibits hepatitis C replication in humans

BACKGROUND: Hepatitis C viral (HCV) infection is the leading cause of death due to liver disease in the United States. Currently, pegylated interferon and ribavirin produce sustained viral remission in only 50% of patients. Additional agents are needed to increase the cure rate. In vitro experiments show strong antiviral effects of fluvastatin against HCV.

OBJECTIVES: To assess the safety and antiviral effects of fluvastatin in chronic HCV carriers.

METHODS: 31 veterans with chronic HCV were prospectively given oral doses of fluvastatin, 20 to 320 mg/day, for 2-12 weeks with weekly monitoring of HCV RNA and liver tests. Reductions of viral load (P < 0.01) versus a control group were considered suppressive.

RESULTS: With 80 mg a day or less, 11/22 (50%) patients responded by lowering HCV RNA. The first lowering occurred within 4 weeks (9/11, 82%). The greatest weekly change in HCV RNA level was a 1.75 log(10) reduction. When lowered in responders, the viral load remained relatively constant for 2-5 weeks (7/9, 78%), or on the next test rebounded immediately to a non-significant change from, baseline (n = 2). Continued lowering of virus was seen in 2/19 (22 %) patients when the study ended. We found no evidence of liver tests worsening.

CONCLUSIONS: FLV used as monotherapy in vivo showed suppressive effects of HCV clinically that are modest, variable, and often short-lived. These findings support "proof-of-concept" for pilot trials combining fluvastatin with standard therapy. Statins and fluvastatin, in particular, appear to be safe for use in hepatitis C.

Read full study.

¹²(But a caution): Milazzo L, Meroni L, Galazzi M, Cesari M, Caramma I, Marchetti G, Galli M, Antinori S.Does fluvastatin favour HCV replication in vivo? A pilot study on HIV-HCV coinfected patients. J Viral Hepat. 2009 Jul;16(7):479-84. Epub 2009 Feb 8.

¹³Statins Inhibit HIV-1 Infection by Down-regulating Rho Activity. J Exp Med. 2004 August 16; 200(4): 541–547. PMCID: PMC2211926. doi: 10.1084/jem.20040061.

Gustavo del Real, Sonia Jiménez-Baranda, Emilia Mira, Rosa Ana Lacalle, Pilar Lucas, Concepción Gómez-Moutón, Marta Alegret, Jose María Peña, Manuel Rodríguez-Zapata, Melchor Alvarez-Mon, Carlos Martínez-A., and Santos Mañes

Abstract: Statins Inhibit HIV-1 Infection by Down-regulating Rho Activity

Human immunodeficiency virus (HIV)-1 infectivity requires actin-dependent clustering of host lipid raft–associated receptors, a process that might be linked to Rho guanosine triphosphatase (GTPase) activation. Rho GTPase activity can be negatively regulated by statins, a family of drugs used to treat hypercholesterolemia in man. Statins mediate inhibition of Rho GTPases by impeding prenylation of small G proteins through blockade of 3-hydroxy-3-methylglutaryl coenzyme A reductase. We show that statins decreased viral load and increased CD4+ cell counts in acute infection models and in chronically HIV-1–infected patients. Viral entry and exit was reduced in statin-treated cells, and inhibition was blocked by the addition of l-mevalonate or of geranylgeranylpyrophosphate, but not by cholesterol. Cell treatment with a geranylgeranyl transferase inhibitor, but not a farnesyl transferase inhibitor, specifically inhibited entry of HIV-1–pseudotyped viruses. Statins blocked Rho-A activation induced by HIV-1 binding to target cells, and expression of the dominant negative mutant RhoN19 inhibited HIV-1 envelope fusion with target cell membranes, reducing cell infection rates. We suggest that statins have direct anti–HIV-1 effects by targeting Rho.

One area of HIV-1 research aims to understand the interplay between virus and host cell, to block key interactions between virus and host target, and to prevent virus propagation without the inconvenience of HAART. Effort has concentrated on the HIV-1 entry and budding processes, which require the formation of large clusters between viral and host cell proteins (1). Results suggest that HIV-1 entry into and exit from the host cell require actin cytoskeleton rearrangement and adequate cholesterol levels in host and viral membranes (2–13). A means remains to be found for specific targeting of these host factors to prevent HIV-1 propagation with minimal toxicity.

Statins are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors used to treat hypercholesterolemia. HMG-CoA reductase produces mevalonic acid, a precursor for cholesterol biosynthesis and generation of isoprenoids that modify specific cell proteins posttranslationally. Rho guanosine triphosphatases (GTPases), which must be prenylated at their C terminus for function, are molecular switches that cycle between GTP-bound (active) and GDP-bound (inactive) states to control actin cytoskeleton remodeling in response to stimuli (14). By targeting HMG-CoA, statins block cholesterol biosynthesis, but also affect actin cytoskeleton rearrangement by inhibiting Rho GTPases (15).

We show that statins inhibited HIV-1 infection of SCID mice grafted with adult human PBMCs (SCID-hu-PBMC), an in vivo model of acute HIV-1 infection. Statins inhibited virus entry into and exit from target cells by targeting Rho geranylation. Strikingly, 1-mo oral statin administration reduced serum HIV-1 RNA copy number in chronically HIV-1–infected individuals not receiving HAART. Our results indicate that statins might be suitable antiretroviral drugs for more accessible AIDS treatment.

From: J Exp Med. 2004 August 16; 200(4): 541–547. doi: 10.1084/jem.20040061.

¹⁴Antiviral activity of lovastatin against respiratory syncytial virus in vivo and in vitro. Gower TL, Graham BS. Antimicrob Agents Chemother. 2001 Apr;45(4):1231-7.

Abstract: Antiviral activity of lovastatin against respiratory syncytial virus in vivo and in vitro.

Respiratory syncytial virus (RSV) is an important human pathogen that can cause severe and life-threatening respiratory infections in infants and immunocompromised adults. We have recently shown that the RSV F glycoprotein, which mediates viral fusion, binds to RhoA. One of the steps in RhoA activation involves isoprenylation at the carboxy terminus of the protein by geranylgeranyltransferase. This modification allows RhoA to be attached to phosphatidyl serine on the inner leaflet of the plasma membrane. Treatment of mice with lovastatin, a drug that inhibits prenylation pathways in the cell by directly inhibiting hydroxymethylglutaryl coenzyme A reductase, diminishes RSV but not vaccinia virus replication when administered up to 24 h after RSV infection and decreases virus-induced weight loss and illness in mice. The inhibition of replication is not likely due to the inhibition of cholesterol biosynthesis, since gemfibrozil, another cholesterol-lowering agent, did not affect virus replication and serum cholesterol levels were not significantly lowered by lovastatin within the time frame of the experiment. Lovastatin also reduces cell-to-cell fusion in cell culture and eliminates RSV replication in HEp-2 cells. These data indicate that lovastatin, more specific isoprenylation inhibitors, or other pharmacological approaches for preventing RhoA membrane localization should be considered for evaluation as a preventive antiviral therapy for selected groups of patients at high risk for severe RSV disease, such as the institutionalized elderly and bone marrow or lung transplant recipients.

¹⁵Pandemic Influenza: A Potential Role for Statins in Treatment and Prophylaxis. David S. Fedsona. Clin Infect Dis. (2006) 43 (2): 199-205. doi: 10.1086/505116

Abstract: Pandemic Influenza: A Potential Role for Statins in Treatment and Prophylaxis

The next influenza pandemic may be imminent. Because antiviral agents and vaccines will be unavailable to people in most countries, we need to determine whether other agents could offer clinical benefits. Influenza is associated with an increase in acute cardiovascular diseases, and influenza viruses induce proinflammatory cytokines. Statins are cardioprotective and have anti-inflammatory and immunomodulatory effects, and they thus might benefit patients with influenza. This hypothesis should be evaluated by using administrative databases to search for reduced rates of hospitalization and death due to influenza-related conditions among people taking statins. These studies should be followed by laboratory studies of statins in animal and cell-based models of influenza virus infection and, later, by clinical trials. Positive results from such studies would provide physicians in all countries with something to offer patients for treatment and prophylaxis of pandemic influenza. Generic statins will be widely distributed and inexpensive. They might be the only agents that could alter the course of a global pandemic.