Dysregulation of Gene Expression of Key Signaling Mediators in PBMCs from People with Type 2 Diabetes Mellitus.

Diabetes is currently the fifth leading cause of death by disease in the USA. The underlying mechanisms for type 2 Diabetes Mellitus (DM2) and the enhanced susceptibility of such patients to inflammatory disorders and infections remain to be fully defined. We have recently shown that peripheral blood mononuclear cells (PBMCs) from non-diabetic people upregulate expression of inflammatory genes in response to proteasome modulators, such as bacterial lipopolysaccharide (LPS) and soybean lectin (LEC); in contrast, resveratrol (RES) downregulates this response.

Reprograming of Gene Expression of Key Inflammatory Signaling Pathways in Human Peripheral Blood Mononuclear Cells by Soybean Lectin and Resveratrol.

Inflammation is linked to several human diseases like microbial infections, cancer, heart disease, asthma, diabetes, and neurological disorders. We have shown that the prototype inflammatory agonist LPS modulates the activity of Ubiquitin-Proteasome System (UPS) and regulates transcription factors such as NF-κB, leading to inflammation, tolerance, hypoxia, autophagy, and apoptosis of cells. We hypothesized that proteasome modulators resveratrol and soybean lectin would alter the gene expression of mediators involved in inflammation-induced signaling pathways, when administered ex vivo to human peripheral blood mononuclear blood cells (PBMCs) obtained from normal healthy controls.

δ-Tocotrienol feeding modulates gene expression of EIF2, mTOR, protein ubiquitination through multiple-signaling pathways in chronic hepatitis C patients.

Background: δ-Tocotrienol is a naturally occurring proteasome inhibitor, which has the capacity to inhibit proliferation and induce apoptosis in several cancer cells obtained from several organs of humans, and other cancer cell lines. Moreover, results of plasma total mRNAs after δ-tocotrienol feeding to hepatitis C patients revealed significant inhibition in the expression of pro-inflammatory cytokines (TNF-α, VCAM1, proteasome subunits) and induction in the expression of ICAM1 and IFN-γ after post-treatment. This down-regulation of proteasome subunits leads to autophagy, apoptosis of immune cells and several genes.

Proteasome inhibitors modulate anticancer and anti-proliferative properties via NF-kB signaling, and ubiquitin-proteasome pathways in cancer cell lines of different organs.

Background: Cancer is second most common cause of death in the United State. There are over 100 different types of cancer associated with different human organs, predominantly breast, liver, pancreas, prostate, colon, rectum, lung, and stomach. We have recently reported properties of pro-inflammatory (for treatment of various types of cancers), and anti-inflammatory (for cardiovascular disease and diabetes) compounds.

Resveratrol Downregulates Biomarkers of Sepsis Via Inhibition of Proteasome's Proteases.

Lipopolysaccharide (LPS) is the main agonist of gram-negative bacteria and initiates inflammation. We recently reported that plasmas from sepsis patients revealed increased levels of following group of biomarkers; VCAM-1, ICAM1, CRP, resistin, and proteasome LMP subunits. Our objective here was to compare effects of resveratrol (shown to be a nonspecific proteasome inhibitor by us) and a known LMP7 inhibitor (ONX-0914, specific inhibitor) on proteasome's activities, as well as on inflammatory markers mentioned above in human blood monocytes.

Of Mice and Men: Proteasome's Role in LPS-Induced Inflammation and Tolerance.

The molecular basis responsible for tolerance following inflammatory response to lipopolysaccharide (LPS) is not well understood. We hypothesized that inflammation/tolerance in monocytes/ macrophages is dependent on the proteases of proteasome. To test our hypothesis, first, we examined the expression of different proteasome subunits in different human and mouse monocytes/macrophages.

Evaluation of Pharmacokinetics, and Bioavailability of Higher Doses of Tocotrienols in Healthy Fed Humans.

Background: Tocotrienols has been known to lower serum lipid parameters below 500 mg/d, while increase lipid parameters at higher dose of 750 mg/d. δ-Tocotrienol has a novel inflammatory property of concentration-dependent inhibition and activation. Therefore, inhibition (anti-inflammatory) property of tocotrienols at low doses is useful for cardiovascular disease, whereas, activation (pro-inflammatory) property using high dose is found effective for treatments of various types of cancer.

Mammalian Lipopolysaccharide Receptors Incorporated into the Retroviral Envelope Augment Virus Transmission.

The orally transmitted retrovirus mouse mammary tumor virus (MMTV) requires the intestinal microbiota for persistence. Virion-associated lipopolysaccharide (LPS) activates Toll-like receptor 4 (TLR4), stimulating production of the immunosuppressive cytokine IL-10 and MMTV evasion of host immunity. However, the mechanisms by which MMTV associates with LPS remain unknown.

Nutritional Supplement-5 with a Combination of Proteasome Inhibitors (Resveratrol, Quercetin, -Tocotrienol) Modulate Age-Associated Biomarkers and Cardiovascular Lipid Parameters in Human Subjects.

Background: Age-associated altered redox imbalances and dysregulated immune function, contribute to the development of a variety of age associated diseases. Inflammatory markers and lipid profiles are useful prognostic indicators of a variety of age-associated and cardiovascular diseases. We have previously studied the impact of several proteasome inhibitors on several markers of inflammation and lipid profiles , in cell lines, animal models, and in human subjects.

Suppression of Nitric Oxide Production and Cardiovascular Risk Factors in Healthy Seniors and Hypercholesterolemic Subjects by a Combination of Polyphenols and Vitamins.

BACKGROUND: Dysregulated immune function associated with ageing has been implicated in a variety of human diseases. We have demonstrated the anti-inflammatory properties of resveratrol, pterostilbene, morin hydrate, quercetin, δ-tocotrienol, riboflavinin a variety of experimental animal models, and determined that these compounds act by inhibiting proteasome activity. AIMS: To determine whether serum nitric oxide (NO) levels increase with age in humans, and whether the combined cholesterol-lowering and inflammation-reducing properties of resveratrol, pterostilbene, Morin hydrate, quercetin, δ-tocotrienol, riboflavin, and nicotinic acid would reduce cardiovascular risk factors in humans when used as nutritional supplements with, or without, other dietary changes.

Proteasome protease mediated regulation of cytokine induction and inflammation.

We have previously demonstrated that proteasome serves as a central regulator of inflammation and macrophage function. Until recently, proteasomes have generally been considered to play a relatively passive role in the regulation of cellular activity, i.e.

Inhibition of nitric oxide and inflammatory cytokines in LPS-stimulated murine macrophages by resveratrol, a potent proteasome inhibitor.

Background: Altered immune function during ageing results in increased production of nitric oxide (NO) and other inflammatory mediators. Recently, we have reported that NO production was inhibited by naturally-occurring proteasome inhibitors (quercetin, δ-tocotrienol, and riboflavin) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and thioglycolate-elicited peritoneal macrophages from C57BL/6 mice.

Methamphetamine increases LPS-mediated expression of IL-8, TNF-α and IL-1β in human macrophages through common signaling pathways.

The use of methamphetamine (MA) has increased in recent years, and is a major health concern throughout the world. The use of MA has been associated with an increased risk of acquiring HIV-1, along with an increased probability of the acquisition of various sexually transmitted infections. In order to determine the potential effects of MA exposure in the context of an infectious agent, U937 macrophages were exposed to various combinations of MA and bacterial lipopolysaccharide (LPS).

A critical role for the inducible proteasomal subunits LMP7 and MECL1 in cytokine production by activated murine splenocytes.

Background And Purpose: The proteasome is a multi-subunit complex that proteolytically cleaves proteins. The replacement of the constitutive proteasome subunits β1, β2, and/or β5 with the IFNγ-inducible subunits LMP2, MECL1, and/or LMP7 results in the 'immunoproteasome'. The inducible subunits change the cleavage specificities of the proteasome, but it is unclear whether they have functions in addition to this.

Inhibition of nitric oxide in LPS-stimulated macrophages of young and senescent mice by δ-tocotrienol and quercetin.

Background: Changes in immune function believed to contribute to a variety of age-related diseases have been associated with increased production of nitric oxide (NO). We have recently reported that proteasome inhibitors (dexamethasone, mevinolin, quercetin, δ-tocotrienol, and riboflavin) can inhibit lipopolysaccharide (LPS)-induced NO production in vitro by RAW 264.7 cells and by thioglycolate-elicited peritoneal macrophages derived from four strains of mice (C57BL/6, BALB/c, LMP7/MECL-1(-/-) and PPAR-α(-/-) knockout mice).

Suppression of nitric oxide induction and pro-inflammatory cytokines by novel proteasome inhibitors in various experimental models.

Background: Inflammation has been implicated in a variety of diseases associated with ageing, including cancer, cardiovascular, and neurologic diseases. We have recently established that the proteasome is a pivotal regulator of inflammation, which modulates the induction of inflammatory mediators such as TNF-α, IL-1, IL-6, and nitric oxide (NO) in response to a variety of stimuli. The present study was undertaken to identify non-toxic proteasome inhibitors with the expectation that these compounds could potentially suppress the production of inflammatory mediators in ageing humans, thereby decreasing the risk of developing ageing related diseases.

A variety of novel lipid A structures obtained from Francisella tularensis live vaccine strain.

F. tularensis is a Gram-negative coccobacillus that causes tularemia. Its LPS has nominal biological activity.

Tocotrienols-induced inhibition of platelet thrombus formation and platelet aggregation in stenosed canine coronary arteries.

Background: Dietary supplementation with tocotrienols has been shown to decrease the risk of coronary artery disease. Tocotrienols are plant-derived forms of vitamin E, which have potent anti-inflammatory, antioxidant, anticancer, hypocholesterolemic, and neuroprotective properties. Our objective in this study was to determine the extent to which tocotrienols inhibit platelet aggregation and reduce coronary thrombosis, a major risk factor for stroke in humans.

Gene profiling of early and advanced liver disease in chronic hepatitis C patients.

Purpose: Strong impact of hepatitis C virus (HCV) on normal regulation of cellular processes has been reported that could have significant implications for HCV pathogenesis. We aimed to determine the altered cellular processes during HCV infection with particular reference to advanced disease stages.

Methods: Liver biopsy specimens of chronic hepatitis C patients classified on histological basis as early (fibrosis stage 1-2) or advanced (fibrosis stage 3-4) HCV disease were studied using microarray technology (Affymetrix GeneChip™ System).

LPS-induced formation of immunoproteasomes: TNF-α and nitric oxide production are regulated by altered composition of proteasome-active sites.

Stimulation of mouse macrophages with LPS leads to tumor necrosis factor (TNF-α) secretion and nitric oxide (NO) release at different times through independent signaling pathways. While the precise regulatory mechanisms responsible for these distinct phenotypic responses have not been fully delineated, results of our recent studies strongly implicate the cellular cytoplasmic ubiquitin-proteasome pathway as a key regulator of LPS-induced macrophage inflammatory responses. Our objective in this study was to define the relative contribution of specific proteasomal active-sites in induction of TNF-α and NO after LPS treatment of RAW 264.

The immunoproteasomes regulate LPS-induced TRIF/TRAM signaling pathway in murine macrophages.

We have proposed the novel concept that the macrophage ubiquitin-proteasome pathway functions as a key regulator of Lipopolysaccharide (LPS)-induced inflammation signaling. These findings suggest that proteasome-associated protease subunits X, Y, and Z are replaced by LMP subunits after LPS treatment of RAW 264.7 cells.

δ-Tocotrienol and quercetin reduce serum levels of nitric oxide and lipid parameters in female chickens.

Background: Chronic, low-grade inflammation provides a link between normal ageing and the pathogenesis of age-related diseases. A series of in vitro tests confirmed the strong anti-inflammatory activities of known inhibitors of NF-κB activation (δ-tocotrienol, quercetin, riboflavin, (-) Corey lactone, amiloride, and dexamethasone). δ-Tocotrienol also suppresses β-hydroxy-β-methylglutaryl coenzyme A (HMG-CoA) reductase activity (the rate-limiting step in de novo cholesterol synthesis), and concomitantly lowers serum total and LDL cholesterol levels.

Crocetin reduces activation of hepatic apoptotic pathways and improves survival in experimental hemorrhagic shock.

Background: Hemorrhagic shock results in cellular damage and cell death. A primary mechanism is cellular apoptosis from mitochondrial damage. This study demonstrated that administration of crocetin to experimental animals during resuscitation from shock significantly improved postshock survival and reduced apoptosis.

Tocotrienols inhibit lipopolysaccharide-induced pro-inflammatory cytokines in macrophages of female mice.

Background: Inflammation has been implicated in cardiovascular disease, and the important role of proteasomes in the development of inflammation and other macrophage functions has been demonstrated. Tocotrienols are potent hypocholesterolemic agents that inhibit β-hydroxy-β-methylglutaryl coenzyme A reductase activity, which is degraded via the ubiquitin-proteasome pathway. Our objective was to evaluate the effect of tocotrienols in reducing inflammation.