Modulatory effects of bortezomib on host immune cell functions.

Bortezomib is an inhibitor of the ubiquitin-proteasome proteolytic pathway responsible for intracellular protein turnover. Cellular proteins controlled by this pathway represent a diverse group of potential therapeutic targets, particularly in cancer cells, which exploit this proteasomal pathway to promote their growth and diminish apoptosis. Along with inhibiting the proteasome and thus sensitizing tumor cells to apoptosis, bortezomib may also have multiple effects on the host immune responses. This review summarizes the effects that bortezomib may play on immune cell subsets in various disease states in modifying lymphocyte receptors, ligands, the expression of various cytokines and chemokines and their downstream signaling. We also propose steps that can be taken to refine combinatorial strategies that include bortezomib to improve current immunotherapeutic approaches.

Vespa tropica venom suppresses lipopolysaccharide-mediated secretion of pro-inflammatory cyto-chemokines by abrogating nuclear factor-κ B activation in microglia.

OBJECTIVE AND DESIGN: The present study was aimed to evaluate the anti-inflammatory potentials of Vespa tropica (VT) venom and its isolated peptides. Effects of whole venom and its two peptides (Vt1512 and Vt1386) on lipopolysaccharide (LPS) challenged BV-2 murine microglial cells was evaluated. MATERIALS: Mouse microglial cell line, BV-2 and crude venom extract as well as purified peptides from VT along with LPS from Salmonella enterica were used for the studies. TREATMENT: BV-2 cells were treated with 500 ng/ml of LPS and different doses of crude wasp venom as well as purified peptides. METHODS: We used immunoblotting, cytokine bead arrays and fluorescence activated cell sorter (FACS) to evaluate the levels of various proteins, cytokines and reactive oxygen species (ROS). RESULTS: Our studies suggest that treatment with whole venom significantly reduces oxidative stress and LPS-stimulated activation of microglia. Also, purified peptides from crude venom exhibited potential anti-inflammatory properties. Further, whole venom was found to be targeting Akt and p38 MAPK pathways, leading to suppressed NF-κB phosphorylation in LPS challenged BV-2 cells. CONCLUSIONS: VT venom possesses anti-inflammatory properties and can be further explored for their therapeutic potential in treating various inflammatory conditions of the central nervous system (CNS).

MicroRNA 155 regulates Japanese encephalitis virus-induced inflammatory response by targeting Src homology 2-containing inositol phosphatase 1.

UNLABELLED: MicroRNAs (miRNAs) are single-stranded small RNA molecules that regulate various cellular processes. miRNA 155 (miR-155) regulates various aspects of innate and adaptive immune responses and plays a key role in various viral infections and the resulting neuroinflammation. The present study evaluated the involvement of miR-155 in modulating Japanese encephalitis virus (JEV)-induced neuroinflammation. We observed that miR-155 expression was upregulated during JEV infection of mouse primary microglia, the BV-2 microglia cell line, and in both mouse and human brains. In vitro and in vivo knockdown of miR-155 minimized JEV-induced inflammatory responses. In the present study, we confirmed targeting of the Src homology 2-containing inositol phosphatase 1 (SHIP1) 3' untranslated region (UTR) by miR-155 in the context of JEV infection. Inhibition of SHIP1 by miR-155 resulted in higher beta interferon (IFN-ß) and proinflammatory cytokine production through activation of TANK-binding kinase 1 (TBK-1). Based on these observations, we conclude that miR-155 modulates the neuroinflammatory response during JEV infection via negative regulation of SHIP1 expression. Thus, modulation of miR-155 could be a novel strategy to regulate JEV-induced neuroinflammation. IMPORTANCE: Japanese encephalitis virus (JEV), a member of the family Flaviviridae that causes Japanese encephalitis (JE), is the most common mosquito-borne encephalitis virus in the Asia-Pacific region. The disease is feared, as currently there are no specific antiviral drugs available. JEV targets the central nervous system, leading to high mortality and neurological and psychiatric sequelae in some of those who survive. The level of inflammation correlates well with the clinical outcome in patients. Recently, microRNA (miRNA), a single-stranded noncoding RNA, has been implicated in various brain disorders. The present study investigates the role of miRNA in JEV-induced neuroinflammation. Our results show that miRNA 155 (miR-155) targets the Src homology 2-containing inositol phosphatase 1 (SHIP1) protein and promotes inflammation by regulating the NF-κB pathway, increasing the expression of various proinflammatory cytokines and the antiviral response. Thus, miR-155 is a potential therapeutic target to develop antivirals in JE and other brain disorders where inflammation plays a significant role in disease progression.

MicroRNA-29b modulates Japanese encephalitis virus-induced microglia activation by targeting tumor necrosis factor alpha-induced protein 3.

Japanese encephalitis virus (JEV), a single-stranded RNA (ssRNA) virus, is the leading cause of encephalitis in Asia. Microglial activation is one of the key events in JEV-induced neuroinflammation. Although the various microRNAs (miRNAs) has been shown to regulate microglia activation during pathological conditions including neuroviral infections, till date, the involvement of miRNAs in JEV infection has not been evaluated. Hence, we sought to evaluate the possible role of miRNAs in mediating JEV-induced microglia activation. Initial screening revealed significant up-regulation of miR-29b in JEV-infected mouse microglial cell line (BV-2) and primary microglial cells. Furthermore, using bioinformatics tools, we identified tumor necrosis factor alpha-induced protein 3, a negative regulator of nuclear factor-kappa B signaling as a potential target of miR-29b. Interestingly, in vitro knockdown of miR-29b resulted in significant over-expression of tumor necrosis factor alpha-induced protein 3, and subsequent decrease in nuclear translocation of pNF-κB. JEV infection in BV-2 cell line elevated inducible nitric oxide synthase, cyclooxygenase-2, and pro-inflammatory cytokine expression levels, which diminished after miR-29b knockdown. Collectively, our study demonstrates involvement of miR-29b in regulating JEV- induced microglial activation.

Protective role of standardized Feronia limonia stem bark methanolic extract against carbon tetrachloride induced hepatotoxicity.

OBJECTIVE: This study evaluates hepatoprotective potential of Feronia limonia stem bark (FSB) extracts and fractions using experimental models. MATERIALS AND METHODS: Activity levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and cell viability were evaluated in HepG2 cells treated with carbon tetrachloride (CCl4) in presence or absence of FL extracts or fractions. Also, plasma markers of hepatic damage, hepatic antioxidants, lipid peroxidation and histopathological alterations were assessed in rats treated with CCl4 alone or in combination with 200 or 400 mg/kg bodyweight (BW) of FSB-7 or 25 mg/kg BW of silymarin. RESULTS: In vitro co-supplementation of FSB extracts or fractions recorded varying degree of hepatoprotective potentials. Also, pre-supplementation of FSB methanolic extract (FSB-7) followed by CCl4 treatment significantly prevented hepatic damage and depletion of cellular antioxidants. Also, CCl4+ FSB-7 group showed minimal distortion in the histoarchitecture of liver and results were comparable to that of CCl4+ silymarin treated rats. CONCLUSION: This inventory is the first scientific report on hepatoprotective potential of FSB methanolic extract.