The IKK␤ and NEMO/IKK␥ subunits of the NF-B-activating signalsome complex are known to be essential for activating NF-B by inflammatory and other stresslike stimuli. However, the IKK␣ subunit is believed to be dispensable for the latter responses and instead functions as an in vivo mediator of other novel NF-B-dependent and -independent functions. In contrast to this generally accepted view of IKK␣'s physiological functions, we demonstrate in mouse embryonic fibroblasts (MEFs) that, akin to IKK␤ and NEMO/IKK␥, IKK␣ is also a global regulator of tumor necrosis factor ␣-and IL-1-responsive IKK signalsome-dependent target genes including many known NF-B targets such as serum amyloid A3, C3, interleukin (IL)-6, IL-11, IL-1 receptor antagonist, vascular endothelial growth factor, Ptx3, ␤ 2 -microglobulin, IL-1␣, Mcp-1 and -3, RANTES (regulated on activation normal T cell expressed and secreted), Fas antigen, Jun-B, c-Fos, macrophage colony-stimulating factor, and granulocyte-macrophage colony-stimulating factor. Only a small number of NF-B-dependent target genes were preferentially dependent on IKK␣ or IKK␤. Constitutive expression of a trans-dominant I B␣ superrepressor (I B␣SR) in wild type MEFs confirmed that these signalsome-dependent target genes were also dependent on NF-B. A subset of NF-B target genes were IKK-dependent in the absence of exogenous stimuli, suggesting that the signalsome was also required to regulate basal levels of activated NF-B in established MEFs. Overall, a sizable number of novel NF-B/IKK-dependent genes were identified including Secreted Frizzled, cadherin 13, protocadherin 7, CCAAT/enhancer-binding protein-␤ and -␦, osteoprotegerin, FOXC2 and FOXF2, BMP-2, p75 neurotrophin receptor, caspase-11, guanylate-binding proteins 1 and 2, ApoJ/clusterin, interferon (␣ and ␤) receptor 2, decorin, osteoglycin, epiregulin, proliferins 2 and 3, stromal cell-derived factor, and cathepsins B, F, and Z. SOCS-3, a negative effector of STAT3 signaling, was found to be an NF-B/IKK-induced gene, suggesting that IKKmediated NF-B activation can coordinately illicit negative effects on STAT signaling.The NF-B transcription factors are pivotal regulators of gene expression programs culminating in stress-like responses and the genesis of innate and acquired immunity (reviewed in Refs. 1-4). A host of extracellular stimuli including inflammatory cytokines, viral and bacterial infections, oxidative and DNA-damaging agents, UV light, and osmotic shock can all result in NF-B activation (1, 3-5). NF-B transcription factors bind to DNA as hetero-or homodimers that are selectively derived from five possible subunits (RelA/p65, c-Rel, RelB, p50, and p52) with each binding to half of a conserved 10-base pair consensus sequence (GGGRNWTYCC) (1, 5). Whereas the RelA/p65 and p50 subunits are ubiquitously expressed, the p52, c-Rel, and RelB subunits are more functionally important in specific differentiated cell types (1, 6). Cytoplasmic p50/p65 heterodimers, c-Rel homodimers, and RelB are bound to I Bs (inhibitors of NF-B...

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Elevated levels of reactive oxygen species (ROS) have commonly been implicated in a variety of diseases, including cancer, inflammation, and neurodegenerative diseases. In light of significant differences in ROS levels between the nonpathogenic and pathological tissues, an increasing number of ROS-responsive prodrugs, probes, and theranostic prodrugs have been developed for the targeted treatment and precise diagnosis of ROS-related diseases. This review will summarize and provide insight into recent advances in ROS-responsive prodrugs, fluorescent probes, and theranostic prodrugs, with applications to different ROS-related diseases and various subcellular organelle-targetable and disease-targetable features. The ROS-responsive moieties, the self-immolative linkers, and the typical activation mechanism for the ROS-responsive release are also summarized and discussed.

Leukocyte recruitment in the liver includes a two-step procedure in which selectin-dependent leukocyte rolling is a prerequisite for subsequent CD18-dependent leukocyte firm adhesion in postsinusoidal venules. However, the roles of the individual selectins in leukocyte rolling and adhesion, hepatocellular injury, and apoptosis remain elusive. Therefore, we examined the pathophysiological role of P-, E-, and L-selectin in male C57BL/6 mice challenged with lipopolysaccharide (LPS) and D-galactosamine (Gal) by use of intravital microscopy of the liver microcirculation. In control animals, administration of LPS-Gal provoked reproducible hepatic damage, including marked increases of leukocyte recruitment, liver enzymes, and hepatocyte apoptosis and reduced sinusoidal perfusion. Interestingly, pretreatment with an anti-P-selectin antibody (RB40.34) markedly reduced leukocyte rolling and firm adhesion by 65 and 71%, respectively. Moreover, interference with P-selectin function significantly improved sinusoidal perfusion and reduced the increase in liver enzymes by 49 to 84% in endotoxemic mice. Moreover, the activity of caspase-3 and the number of apoptotic hepatocytes were significantly reduced by 55 and 54%, respectively, in RB40.34-treated animals. In contrast, administration of an anti-E-selectin antibody (10E9.6) and an anti-L-selectin antibody (Mel-14) did not protect against endotoxin-induced leukocyte responses or hepatic injury. In conclusion, our novel findings document a principal role of P-selectin in mediating leukocyte rolling, a precondition to the subsequent firm adhesion of leukocytes in liver injury. Furthermore, our novel data demonstrate that inhibition of P-selectin function reduces hepatocellular injury and apoptosis, suggesting a causal relationship between leukocyte recruitment on one hand and hepatocellular injury and apoptosis on the other hand. Based on these findings, it is suggested that P-selectin may be an important therapeutic target in endotoxin-induced liver injury.Activation and recruitment of leukocytes are features associated with liver injury in, e.g., ischemia-reperfusion and endotoxemia (10,12,23). In general, studies of various tissues have shown that infiltration of leukocytes involves a multistep cascade in which the initial rolling interaction between leukocytes and the endothelium is predominately mediated by the selectin family of adhesion molecules, including P-, E-, and L-selectin (1,15,20,31). Subsequent firm adhesion of leukocytes to the endothelium is dependent on the function of ␤ 1 -and ␤ 2 -integrins (CD11/18) on leukocytes, interacting with members of the immunoglobulin supergene family expressed on activated endothelial cells, such as ICAM-1 and -2 and VCAM-1 (1,12,15,16,20,21,31).However, the literature on the specific roles of P-, E-, and L-selectin and the relationship between leukocyte recruitment, cellular injury, and apoptosis is contradictory. For example, when blood flow velocity and shear rates are reduced, it has been suggested that leukocytes may bypass...

The objective of this study was to investigate the regulatory effects of TGF-β1 on CCL3/4 expression and inflammation-related pain during intervertebral disc degeneration (IVDD). TGF-β1 and CCL3/4 expression patterns in different degenerative human nucleus pulposus (NP) tissues were measured by qPCR and immunohistochemistry (IHC), and the effects of TGF-β1 on CCL3/4 expression were measured by qPCR, ELISA and immunofluorescence. The roles of NF-κB and MAPK in TGF-β1-mediated CCL3/4 promoter activity were studied using siRNAs, western blotting and qPCR. After establishing an IVDD rat model in vivo, we administered intradiscal injections of TGF-β1. The effects of TGF-β1 on IVDD were determined by MRI and histological analyses, and the effects of TGF-β1 on dorsal root ganglion (DRG) inflammation and pain development were determined by IHC staining and pain-behavior testing, respectively. TGF-β1 and CCL3/4 expression was elevated in degenerative NP tissue. CCL4 expression was significantly inhibited by TGF-β1 treatment. Pharmacological inhibition or siRNA knockdown of the ERK1/2 signaling attenuated TGF-β1-mediated suppression of CCL4 expression. In vivo, TGF-β1 injection inhibited the development of degenerative features in the IVDD model. Moreover, TGF-β1 prevented the inflammatory response and pain development. The results of this study show that TGF-β1 downregulates CCL4 expression through ERK1/2 signaling activation in NP cells. Furthermore, TGF-β1 can prevent degenerative processes, inhibit inflammatory responses in the DRG and prevent pain development in the IVDD rat model. The results of this study indicate that TGF-β1 may represent a therapeutic target for the control of inflammation-related pain associated with IVDD.