Phosphoinositide 3 kinase enhancer (PIKE) is a recently identified nuclear GTPase that activates nuclear phosphoinositide 3-kinase (PI3 kinase). We have identified, cloned and characterized a new form of PIKE, designated PIKE-L, which, unlike the nuclear PIKE-S, localizes to both the cytoplasm and the nucleus. We demonstrate physiologic binding of PIKE-L to Homer, an adaptor protein known to link metabotropic glutamate receptors to multiple intracellular targets including the inositol 1,4,5-trisphosphate receptor (IP3R). We show that activation of group I metabotropic glutamate receptors (mGluRIs) enhances formation of an mGluRI-Homer-PIKE-L complex, leading to activation of PI3 kinase activity and prevention of neuronal apoptosis. Our findings indicate that this complex mediates the well-known ability of agonists of mGluRI to prevent neuronal apoptosis.

Adiponectin is an adipokine with potent anti-inflammatory properties. However, the mechanisms by which adiponectin suppresses macrophage function are not well understood. Treatment of RAW264.7 macrophages with adiponectin for 18 h decreased lipopolysaccharide (LPS)-stimulated tumor necrosis factor-␣ (TNF-␣) production. Here we demonstrate that globular adiponectin (gAcrp) initially increased TNF-␣ expression in RAW264.7 macrophages; this TNF-␣ then contributed to increased expression of interleukin-10, which in turn was required for the development of tolerance to subsequent LPS exposure. gAcrp-mediated increases in TNF-␣ mRNA accumulation were associated with increased TNF-␣ promoter activity. gAcrp increased the DNA binding activity of both Egr-1 and NFB; mutation of either the Egr-1 or NFB binding sites in the TNF-␣ promoter decreased gAcrp-stimulated promoter activity. Further, co-transfection with either dominant negative Egr-1 or the IB super-repressor prevented gAcrp-stimulated TNF-␣ promoter activity. gAcrp also increased Egr-1 promoter activity, mRNA accumulation, and DNA binding activity. Inhibition of ERK1/2 with U0126 potently suppressed gAcrp-stimulated Egr-1 promoter activity, as well as TNF-␣ promoter activity. In summary, these data demonstrate that adiponectin initially increases TNF-␣ production by macrophages via ERK1/ 23 Egr-1 and NFB-dependent mechanisms; these increases in TNF-␣ in turn lead to increased expression of interleukin-10 and an eventual dampening of LPS-mediated cytokine production in macrophages.

Targeted therapies for cancer are inherently limited by the inevitable recurrence of resistant disease after initial responses. To define early molecular changes within residual tumor cells that persist after treatment, we analyzed drug sensitive lung adenocarcinoma cell lines exposed to reversible or irreversible EGFR inhibitors, alone or in combination with MET kinase inhibitors, to characterize the adaptive response that engenders drug resistance. Tumor cells displaying early resistance exhibited dependence on MET-independent activation of BCL-2/BCL-XL survival signaling. Further, such cells displayed a quiescence-like state associated with greatly retarded cell proliferation and cytoskeletal functions that were readily reversed after withdrawal of targeted inhibitors. Findings were validated in a xenograft model, demonstrating BCL-2 induction and p-STAT3[Y705] activation within the residual tumor cells surviving the initial anti-tumor response to targeted therapies. Disrupting the mitochondrial BCL-2/BCL-XL antiapoptotic machinery in early survivor cells using BH3 mimetic agents such as ABT-737, or by dual RNAi-mediated knockdown of BCL-2/BCL-XL, was sufficient to eradicate the early resistant lung tumor cells evading targeted inhibitors. Similarly, in a xenograft model the preemptive co-treatment of lung tumor cells with an EGFR inhibitor and a BH3 mimetic eradicated early TKI-resistant evaders and ultimately achieved a more durable response with prolonged remission. Our findings prompt prospective clinical investigations using BH3-mimetics combined with targeted receptor kinase inhibitors to optimize and improve clinical outcomes in lung cancer treatment.

Our study may help clarify the molecular mechanisms involved in the pathogenesis of HCC, and miRNAs potentially serve as a novel diagnostic tool of HCC.

No abstract

Adiponectin, an adipokine predominantly secreted from adipose tissue, has potent anti-inflammatory properties. Although the mechanisms for the anti-inflammatory properties of adiponectin are not well understood, recent evidence suggests that increased production of interleukin-10 (IL-10), a potent immunomodulatory cytokine, is involved in the anti-inflammatory actions of adiponectin. Globular adiponectin (gAcrp) increased IL-10 promoter activity and IL-10 mRNA accumulation in RAW 264.7 macrophages. Deletion of the sequences from -416 and -369 in the IL-10 promoter, containing a cyclic AMP-response element (CRE), decreased gAcrp-induced IL-10 promoter activation. Treatment of RAW 264.7 macrophages with gAcrp increased the phosphorylation of cyclic AMP response element binding protein (CREB) at Ser(133), as well as enhanced the DNA binding activity of CREB. Further, overexpression of a dominant negative form of CREB suppressed gAcrp-induced transcriptional activation of IL-10. gAcrp-stimulated CREB phosphorylation was mediated by the activation of both ERK1/2- and cAMP-dependent protein kinase (PKA)-dependent pathways. Inhibition of either ERK1/2 or PKA activity prevented gAcrp-stimulated CREB phosphorylation, as well as gAcrp-stimulated IL-10 promoter activation. Taken together, these data identify gAcrp-stimulated phospho-CREB as a key transcription factor responsible for gAcrp-induced IL-10 promoter activation.

Bone loss that causes aseptic loosening of orthopaedic implants is initiated by pro-inflammatory cytokines produced by macrophages in response to implant-derived wear particles. MAPK and NF-κB signaling pathways are activated by the particles; however, it is not clear which of the signaling pathways are important for the initial response to the wear particles and which are only involved at later steps in the process, such as osteoclast differentiation. Here, we show that the ERK1/2, p38, JNK, and NF-κB pathways are rapidly activated by the wear particles but that only the ERK1/2 and NF-κB pathways are required for the initial response to the wear particles, which include increases in TNFα promoter activity, TNFα mRNA expression, and secretion of TNFα protein. Moreover, ERK1/2 activation by wear particles is also required for increased expression of the transcription factor Egr-1 as well as Egr-1's ability to bind to and activate the TNFα romoter. These results, together with our previous studies of the PI3K/Akt pathway, demonstrate that wear particles coordinately activate multiple signaling pathways and multiple transcription factors to stimulate production of pro-inflammatory cytokines, such as TNFα. The current study also demonstrates that the signaling pathways are activated to a much greater extent by wear particles with adherent endotoxin than by "endotoxin-free" wear particles. These results, together with those demonstrating the requirement for ERK1/2/Egr-1 and NF-κB, show that activation of these signaling pathways is responsible for the ability of adherent endotoxin to potentiate cytokine production, osteoclast differentiation, and bone loss induced by wear particles.

FMS conditioning of the inspiratory and expiratory muscles improved voluntary inspiratory and expiratory functions. FMS may be a noninvasive technology for respiratory muscle training in persons with tetraplegia.