Publications by authors named "Youtong Wu"

Photonic ionogels with dual electrical and optical output have been intensively studied. However, tunable temperature-responsive photonic ionogel assembled by thermosensitive nanogels has not been studied yet. Herein, an innovative approach to fabricate photonic ionogels has been developed for smart wearable devices with tunable temperature sensitivity and structural color.

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Thermally-induced in-situ gelation of polymers and nanogels is of significant importance for injectable non-invasive tissue engineering and delivery systems of drug delivery system. In this study, we for the first time demonstrated that the interpenetrating (IPN) nanogel with two networks of poly (N-isopropylacrylamide) (PNIPAM) and poly (N-Acryloyl-l-phenylalanine) (PAphe) underwent a reversible temperature-triggered sol-gel transition and formed a structural color gel above the phase transition temperature (Tp). Dynamic light scattering (DLS) studies confirmed that the Tp of IPN nanogels are the same as that of PNIPAM, independent of Aphe content of the IPN nanogels at pH of 6.

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Thermally induced physical hydrogels formed through the sol-gel transition of nanogels usually lose structural color above phase transition temperature (T). Herein, temperature/pH/redox-responsive nanogels that undergo sol-gel transition still keep structural colors above the T have been synthesized and studied. N-isopropylacrylamide (NIPAm) was copolymerized with N-tert-butylacrylamide (TBA) and N-acrylamido-l-phenylalanine (Aphe) to form P(NIPAm/TBA/Aphe) nanogel crosslinked with N,N'-bis(acryloyl)cystine (BISS) (referred to as PNTA-BISS).

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The cGAS-STING pathway is essential for immune defense against microbial pathogens and malignant cells; as such, STING is an attractive target for cancer immunotherapy. However, systemic administration of STING agonists poses safety issues while intratumoral injection is limited by tumor accessibility. Here, we generated antibody-drug conjugates (ADCs) by conjugating a STING agonist through a cleavable linker to antibodies targeting tumor cells.

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Full-thickness skin wounds are common accidents. Although healing can be achieved by treatments like autologous skin grafts, donor site morbidity is hardly evitable. In this article, we provide compelling evidence demonstrating that artificial dermal template (ADT)-treated wound healing is achieved by regrowth of skin epidermis as well as adnexa without skin grafts by use of rodent models.

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During virus infection, the adaptor proteins MAVS and STING transduce signals from the cytosolic nucleic acid sensors RIG-I and cGAS, respectively, to induce type I interferons (IFNs) and other antiviral molecules. Here we show that MAVS and STING harbor two conserved serine and threonine clusters that are phosphorylated by the kinases IKK and/or TBK1 in response to stimulation. Phosphorylated MAVS and STING then bind to a positively charged surface of interferon regulatory factor 3 (IRF3) and thereby recruit IRF3 for its phosphorylation and activation by TBK1.

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The mechanism by which cells undergo death determines whether dying cells trigger inflammatory responses or remain immunologically silent. Mitochondria play a central role in the induction of cell death, as well as in immune signaling pathways. Here, we identify a mechanism by which mitochondria and downstream proapoptotic caspases regulate the activation of antiviral immunity.

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Antigen receptor-mediated nuclear factor κB (NF-κB) activation relies on the formation of a large multi-protein complex that contains CARMA1, BCL10, and MALT1 (CBM complex). This signalosome is pirated in the activated B-cell-like subgroup of diffuse large B-cell lymphoma (ABC DLBCL) to drive aberrant NF-κB activation, thereby promoting cell survival and propagation. Using an unbiased proteomic approach, we screened for additional components of the CBM in lymphocytes.

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RNA virus infections are detected by the RIG-I family of receptors, which induce type-I interferons through the mitochondrial protein MAVS. MAVS forms large prion-like polymers that activate the cytosolic kinases IKK and TBK1, which in turn activate NF-κB and IRF3, respectively, to induce interferons. Here we show that MAVS polymers recruit several TRAF proteins, including TRAF2, TRAF5, and TRAF6, through distinct TRAF-binding motifs.

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Retroviruses, including HIV, can activate innate immune responses, but the host sensors for retroviruses are largely unknown. Here we show that HIV infection activates cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) synthase (cGAS) to produce cGAMP, which binds to and activates the adaptor protein STING to induce type I interferons and other cytokines. Inhibitors of HIV reverse transcriptase, but not integrase, abrogated interferon-β induction by the virus, suggesting that the reverse-transcribed HIV DNA triggers the innate immune response.

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In this study we aim to elucidate the signaling pathway and biological function of autophagy induced by MNNG, a commonly used DNA alkylating agent. We first observed that MNNG is able to induce necrotic cell death and autophagy in Bax-/- Bak-/- double knockout MEFs. We analyzed the critical role of PARP-1 activation and ATP depletion in MNNG-mediated cell death and autophagy via AMPK activation and mTOR suppression.

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It has been well documented that cells deficient in either TSC1 or TSC2 are highly sensitive to various cell death stimuli. In this study, we utilized the TSC2 (-/-) mouse embryonic fibroblasts (MEFs) to study the involvement of autophagy in the enhanced susceptibility of TSC2-null cells to cell death. We first confirmed that both TSC1-null and TSC2-null MEFs are more sensitive to apoptosis in response to amino acid starvation (EBSS) and hypoxia.

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The protein kinase Akt (also known as protein kinase B) is a critical signaling hub downstream of various cellular stimuli such as growth factors that control cell survival, growth, and proliferation. The activity of Akt is tightly regulated, and the aberrant activation of Akt is associated with diverse human diseases including cancer. Although it is well documented that the mammalian target of rapamycin complex 2 (mTORC2)-dependent phosphorylation of the Akt hydrophobic motif (Ser-473 in Akt1) is essential for full Akt activation, it remains unclear whether this phosphorylation has additional roles in regulating Akt activity.

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A group of phosphoinositide 3-kinase (PI3K) inhibitors, such as 3-methyladenine (3-MA) and wortmannin, have been widely used as autophagy inhibitors based on their inhibitory effect on class III PI3K activity, which is known to be essential for induction of autophagy. In this study, we systematically examined and compared the effects of these two inhibitors on autophagy under both nutrient-rich and deprivation conditions. To our surprise, 3-MA is found to promote autophagy flux when treated under nutrient-rich conditions with a prolonged period of treatment, whereas it is still capable of suppressing starvation-induced autophagy.

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Our previous work has shown that autophagy plays a pro-survival function in two necrotic cell death models: zVAD-treated L929 cells as well as H(2)O(2)-treated Bax(-/-)Bak(-/-) mouse embryonic fibroblasts (DKO MEF). This study aims to further explore the regulatory role of autophagy in necrosis by examining the functional role of the phosphoinositide-3 kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) signaling pathway. Our initial intriguing finding was that insulin is able to promote necrotic cell death induced by zVAD and MNNG in L929 cells or by H(2)O(2) in DKO MEF cells cultured in full-growth medium.

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The aim of this study is to examine the role of autophagy in cell death by using a well-established system in which zVAD, a pan-caspase inhibitor, induces necrotic cell death in L929 murine fibrosarcoma cells. First, we observed the presence of autophagic hallmarks, including an increased number of autophagosomes and the accumulation of LC3-II in zVAD-treated L929 cells. Since the presence of such autophagic hallmarks could be the result of either increased flux of autophagy or blockage of autophagosome maturation (lysosomal fusion and degradation), we next tested the effect of rapamycin, a specific inhibitor for mTOR, and chloroquine, a lysosomal enzyme inhibitor, on zVAD-induced cell death.

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Objective: To investigate the effects of deltamethrin on the filial brain nitric oxide synthase (NOS) activity and neurobehavioral development of the exposed lactational rats.

Methods: Pregnant rats were randomizedly divided into the treated group and the control group. The treated group was administered orally with 3.

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Objective: To study the effects of deltamethrin (DM) on cell survival rate and intracellular Ca(2+) ([Ca(2+)]i) concentration in primary cultured astrocytes of rat.

Methods: The cell survival rate was measured by Typan Blue assay; the intracellular [Ca(2+)]i concentration was determined by the fluorescent Ca(2+) indicator Fura-2/AM.

Results: The survival rate of astrocytes was decreased to 91.

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Objective: To study the effects of deltamethrin on intracellular free Ca2+ concentration and apoptosis in rat neural cells.

Methods: Wister rats were randomly divided into 4 groups(3 treated groups and 1 control). Intracellular free Ca2+ concentration in rat neural cells was measured by using the fluorescent Ca2+ indicator Fura-2/AM.

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Objective: To elucidate the mechanism of damage on central nervous system (CNS) caused by deltamethrin (DM).

Methods: The mRNA and protein expressions of brain-derived neurotrophic factor (BDNF) in the cerebral cortex and hippocampus of the rats exposed to DM were measured by retro-transcription-polymerase chain reaction (RT-PCR), dot blot, flow cytometry analysis and immunohistochemistry.

Results: After exposure to DM at high-dose (DM1, 25.

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