Chemokine receptors are differentially expressed on immature and mature dendritic cells (DC). Herein, we demonstrate for the first time that murine antimicrobial peptides β-defensins 2 and 3 bind murine CCR6, similarly to inflammatory chemokine macrophage-inflammatory protein 3α, and they chemoattract bone marrow-derived immature, but not mature DC. Using various chemokines or defensins fused with nonimmunogenic tumor Ags, we studied their capacity to delivery Ags to subsets of immune cells to elicit antitumor immunity. We demonstrate that DNA immunizations with fusion constructs with β-defensin 2 or inflammatory chemokines that target immature DC, but not homeostatic chemokines secondary lymphoid tissue chemokine, CCL21, or stromal cell-derived factor 1, CXCL12, which chemoattract mature DC, elicit humoral, protective, and therapeutic immunity against two different syngeneic lymphomas.

Mitochondrial hyperpolarization inhibits the electron transport chain and increases incomplete reduction of oxygen, enabling production of reactive oxygen species (ROS). The consequence is mitochondrial damage that eventually causes cell death. Uncoupling proteins (UCPs) are inner mitochondrial membrane proteins that dissipate the mitochondrial proton gradient by transporting H+ across the inner membrane, thereby stabilizing the inner mitochondrial membrane potential and reducing the formation of ROS. The role of UCP2 in neuroprotection is still in debate. This study seeks to clarify the role of UCP2 in transient focal ischemia (tFI) and to further understand the mechanisms of ischemic brain damage. Both wild-type and UCP2-knockout mice were subjected to tFI. Knocking out UCP2 significantly increased the infarct volume to 61% per hemisphere as compared with 18% in wild-type animals. Knocking out UCP2 suppressed antioxidant, cell-cycle, and DNA repair genes, including Sod1 and Sod2, Gstm1, and cyclins. Furthermore, knocking out UCP2 significantly upregulated the protein levels of the inflammatory cytokines, including CTACK, CXCL16, Eotaxin-2, fractalkine, and BLC. It is concluded that knocking out the UCP2 gene exacerbates neuronal death after cerebral ischemia with reperfusion and this detrimental effect is mediated by alteration of antioxidant genes and upregulation of inflammatory mediators.

Neuroglobin (Ngb) is a hypoxia-inducible protein with cytoprotective effects in animal models of stroke, Alzheimer's disease, and related disorders, but the molecular mechanisms involved in its induction are unknown. We tested the hypothesis that hypoxia-inducible factor-1 (HIF-1) regulates Ngb levels, using shRNA-mediated knockdown and lentiviral vector-mediated overexpression of the HIF-1α subunit, in cultured neural (HN33) cells. HIF-1α knockdown decreased and HIF-1α overexpression increased Ngb levels, consistent with a connection between HIF-1 and Ngb induction. These findings may have implications for understanding the hypoxia-response repertoire of neural cells and devising therapeutic strategies for neurologic disorders.

The ␣7␤1 integrin, dystrophin, and utrophin glycoprotein complexes are the major laminin receptors in skeletal muscle. Loss of dystrophin causes Duchenne muscular dystrophy, a lethal muscle wasting disease. Duchenne muscular dystrophy-affected muscle exhibits increased expression of ␣7␤1 integrin and utrophin, which suggests that these laminin binding complexes may act as surrogates in the absence of dystrophin. Indeed, mice that lack dystrophin and ␣7 integrin (mdx/␣7 ؊/؊ ), or dystrophin and utrophin (mdx/utr ؊/؊ ), exhibit severe muscle pathology and die prematurely. To explore the contribution of the ␣7␤1 integrin and utrophin to muscle integrity and function, we generated mice lacking both ␣7 integrin and utrophin. Surprisingly, mice that lack both ␣7 integrin and utrophin (␣7/utr ؊/؊ ) were viable and fertile. However, these mice had partial embryonic lethality and mild muscle pathology, similar to ␣7 integrin-deficient mice. Dystrophin levels were increased 1.4-fold in ␣7/utr ؊/؊ skeletal muscle and were enriched at neuromuscular junctions. Ultrastructural analysis revealed abnormal myotendinous junctions, and functional tests showed a ninefold reduction in endurance and 1.6-fold decrease in muscle strength in these mice. The ␣7/utr ؊/؊ mouse, therefore, demonstrates the critical roles of ␣7 integrin and utrophin in maintaining myotendinous junction structure and enabling force transmission during muscle contraction. Together, these results indicate that the ␣7␤1 integrin, dystrophin, and utrophin complexes act in a concerted manner to maintain the structural and functional integrity of skeletal muscle. (Am J Pathol

Mitochondria play a critical role in cell survival and death after cerebral ischemia. Uncoupling proteins (UCPs) are inner mitochondrial membrane proteins that disperse the mitochondrial proton gradient by translocating H+ across the inner membrane in order to stabilize the inner mitochondrial membrane potential (ΔΨm) and reduce the formation of reactive oxygen species. Previous studies have demonstrated that mice transgenically overexpressing UCP2 (UCP2 Tg) in the brain are protected from cerebral ischemia, traumatic brain injury and epileptic challenges. This study seeks to clarify the mechanisms responsible for neuroprotection after transient focal ischemia. Our hypothesis is that UCP2 is neuroprotective by suppressing innate inflammation and regulating cell cycle mediators. PCR gene arrays and protein arrays were used to determine mechanisms of damage and protection after transient focal ischemia. Our results showed that ischemia increased the expression of inflammatory genes and suppressed the expression of anti-apoptotic and cell cycle genes. Overexpression of UCP2 blunted the ischemia-induced increase in IL-6 and decrease in Bcl2. Further, UCP2 increased the expression of cell cycle genes and protein levels of phospho-AKT, PKC and MEK after ischemia. It is concluded that the neuroprotective effects of UCP2 against ischemic brain injury are associated with inhibition of pro-inflammatory cytokines and activation of cell survival factors.