SUMMARY Apolipoprotein A-I binding protein (AIBP) reduces lipid raft abundance by augmenting removal of excess of cholesterol from the plasma membrane. Here, we report that AIBP prevents and reverses processes associated with neuroinflammatory-mediated spinal nociceptive processing. The mechanism involves AIBP binding to Toll-like-receptor-4 (TLR4) and increased binding of AIBP to activated microglia, which mediates selective regulation of lipid rafts in inflammatory cells. AIBP-mediated lipid raft reductions downregulated LPS-induced TLR4 dimerization, inflammatory signaling and expression of cytokines in microglia. In mice, intrathecal injections of AIBP reduced spinal myeloid cell lipid rafts, TLR4 dimerization, neuroinflammation, and glial activation. Intrathecal AIBP reversed established allodynia in mice in which pain states were induced by the chemotherapeutic cisplatin, intraplantar formalin, or intrathecal LPS, all pro-nociceptive interventions known to be regulated by TLR4 signaling. These findings demonstrate a mechanism by which AIBP regulates neuroinflammation and suggest the therapeutic potential for AIBP in treating preexisting pain states.

Amphiphilic molecules self-assemble into various structures such as spherical and cylindrical micelles, lamellae, and vesicles in aqueous media, organic solvent, or a mixture of both of these items. [1][2][3] Those self-assemblies have been extensively studied for the past decade due to their unique characteristics and the variety of applications in many areas including the biomedical field. In particular, the vesicular aggregates made of block copolymers, known as polymersomes, 4 have been paid a great deal of recent attention with their high potential use as cellmimicking systems, 5 biosensors, 6 containers or reactors, 7 and vehicles for delivery of bioactive agent. 5,8,9 But until now, studies of polymer vesicles were focused on di-or multiblock copolymers. 5,[10][11][12][13] Although graft copolymers could easily have diverse functionalities by conjugation of functional moieties or drugs onto the polymer backbone, in most cases, spherical micelles were formed as shown in our previous works. [14][15][16] Here, we report the synthesis of novel amphiphilic graft copolymer, poly(2-hydroxyethyl aspartamide) grafted with lactic acid oligomers (PHEA-g-LA), and the structural transition of the self-aggregates as a function of DS (degree of substitution, mole percent of grafted LA segments) which is related to hydrophobic/hydrophilic block ratio. To our best knowledge, we first report the formation of the polymer vesicles from comblike traditional graft copolymers. Besides, the use of aqueous media and the biocompatibility and biodegradability of copolymer material of our system would be essential for later application as delivery carriers.All synthetic routes and the molecular structure of PHEAg-LA are shown in Scheme 1. The precursor polymer, poly-(succinimide) (PSI), was presynthesized by the acid-catalyzed polycondensation of L-aspartic acid using phosphoric acid as the catalyst as previously reported. 16 PHEA containing amine group was prepared by aminolysis of PSI with 0.9 equiv ethanolamine and excess amount of ethylenediamine, respectively. Lactic acid oligomers (LAs) were synthesized by ringopening polymerization of L-lactide using 1-octanol as initiator, and stannous octate as catalyst and purified with diethyl ether. 17 The number-average molecular weight and PDI of LA measured by MALDI-TOF mass spectroscopy were 2412 and 1.02, respectively. The hydroxyl group at the chain terminus of LAs was activated with coupling agent N,N-carbonyldiimidazole (CDI) (LA-CDI), for the grafting reaction. LAs were grafted to the backbone through the formation of carbamate linkage by reaction of amine group in the backbone polymer and purified LA-CDI. In this step, we can control the DS of copolymer

Highlights d H 2 O 2 generation is mediated by interaction of Nox4 with p22 phox -SH3YL1 d SH3YL1-Nox4 regulates pro-inflammatory cytokine production and tubular damage d SH3YL1-Nox4 complex plays an important role in LPSinduced acute kidney injury

Several recent studies have reported that reactive oxygen species (ROS), superoxide anion and hydrogen peroxide (H2O2), play important roles in various cellular signaling networks. NADPH oxidase (Nox) isozymes have been shown to mediate receptor-mediated ROS generation for physiological signaling processes involved in cell growth, differentiation, apoptosis, and fibrosis. Detectable intracellular levels of ROS can be induced by the electron leakage from mitochondrial respiratory chain as well as by activation of cytochrome p450, glucose oxidase and xanthine oxidase, leading to oxidative stress. The up-regulation and the hyper-activation of NADPH oxidases (Nox) also likely contribute to oxidative stress in pathophysiologic stages. Elevation of the renal ROS level through hyperglycemia-mediated Nox activation results in the oxidative stress which induces a damage to kidney tissues, causing to diabetic nephropathy (DN). Nox inhibitors are currently being developed as the therapeutics of DN. In this review, we summarize Nox-mediated ROS generation and development of Nox inhibitors for therapeutics of DN treatment.

The generation of reactive oxygen species (ROS) is required for proper cell signaling, but must be tightly regulated to minimize deleterious oxidizing effects. Activation of the NADPH oxidases (Nox) triggers ROS production and, thus, regulatory mechanisms exist to properly control Nox activity. In this study, we report a novel mechanism in which Nox1 activity is regulated through the proteasomal degradation of Nox organizer 1 (NoxO1). We found that through the interaction between NoxO1 and growth receptor-bound protein 2 (Grb2), the Casitas B-lineage lymphoma (Cbl) E3 ligase was recruited, leading to decreased NoxO1 stability and a subsequent reduction in ROS generation upon epidermal growth factor (EGF) stimulation. Additionally, we show that EGF-mediated phosphorylation of NoxO1 induced its release from Grb2 and facilitated its association with Nox activator 1 (NoxA1) to stimulate ROS production. Consistently, overexpression of Grb2 resulted in decreased Nox1 activity, whereas knockdown of Grb2 led to increased Nox1 activity in response to EGF. CRISPR/Cas9-mediated NoxO1 knockout in human colon cancer cells abrogated anchorage-independent growth on soft agar and tumor-forming ability in athymic nude mice. Moreover, the expression and stability of NoxO1 were significantly increased in human colon cancer tissues compared with normal colon. Taken together, these results support a model whereby Nox1 activity and ROS generation are regulated by Grb2/Cbl-mediated proteolysis of NoxO1 in response to EGF, providing new insight into the processes by which excessive ROS production may promote oncogenic signaling to drive colorectal tumorigenesis.