The dePARylase NUDT16 promotes radiation resistance of cancer cells by blocking SETD3 for degradation via reversing its ADP-ribosylation.

Poly(ADP-ribosyl)ation (PARylation) is a critical posttranslational modification that plays a vital role in maintaining genomic stability via a variety of molecular mechanisms, including activation of replication stress and the DNA damage response. The nudix hydrolase NUDT16 was recently identified as a phosphodiesterase that is responsible for removing ADP-ribose units and that plays an important role in DNA repair. However, the roles of NUDT16 in coordinating replication stress and cell cycle progression remain elusive. Here, we report that SETD3, which is a member of the SET-domain containing protein (SETD) family, is a novel substrate for NUDT16, that its protein levels fluctuate during cell cycle progression, and that its stability is strictly regulated by NUDT16-mediated dePARylation. Moreover, our data indicated that the E3 ligase CHFR is responsible for the recognition and degradation of endogenous SETD3 in a PARP1-mediated PARylation-dependent manner. Mechanistically, we revealed that SETD3 associates with BRCA2 and promotes its recruitment to stalled replication fork and DNA damage sites upon replication stress or DNA double-strand breaks, respectively. Importantly, depletion of SETD3 in NUDT16-deficient cells did not further exacerbate DNA breaks or enhance the sensitivity of cancer cells to IR exposure, suggesting that the NUDT16-SETD3 pathway may play critical roles in the induction of tolerance to radiotherapy. Collectively, these data showed that NUDT16 functions as a key upstream regulator of SETD3 protein stability by reversing the ADP-ribosylation of SETD3, and NUDT16 participates in the resolution of replication stress and facilitates HR repair.

Mechanochemical Fabrication of Full-Color Luminescent Materials from Aggregation-Induced Emission Prefluorophores for Information Storage and Encryption.

The development of luminescent materials via mechanochemistry embodies a compelling yet intricate frontier within materials science. Herein, we delineate a methodology for the synthesis of brightly luminescent polymers, achieved by the mechanochemical coupling of aggregation-induced emission (AIE) prefluorophores with generic polymers. An array of AIE moieties tethered to the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical are synthesized as prefluorophores, which initially exhibit weak fluorescence due to intramolecular quenching. Remarkably, the mechanical coupling of these prefluorophores with macromolecular radicals, engendered through ball milling of generic polymers, leads to substantial augmentation of fluorescence within the resultant polymers. We meticulously evaluate the tunable emission of the AIE-modified polymers, encompassing an extensive spectrum from the visible to the near-infrared region. This study elucidates the potential of such materials in stimuli-responsive systems with a focus on information storage and encryption displays. By circumventing the complexity inherent to the conventional synthesis of luminescent polymers, this approach contributes a paradigm to the field of AIE-based polymers with implications for advanced technological applications.

A Mitochondria-Targeted Nitric Oxide Probe for Multimodality Imaging of Macrophage Immune Responses.

Nitric oxide (NO) is a crucial signal molecule closely linked to the biological immune response, especially in macrophage polarization. When activated, macrophages enter a pro-inflammatory state and produce NO, a marker for the M1 phenotype. In contrast, the anti-inflammatory M2 phenotype does not produce NO. We developed a mitochondria-targeted two-photon iridium-based complex (Ir-ImNO) probe that can detect endogenous NO and monitor macrophages' different immune response states using various imaging techniques, such as one- and two-photon phosphorescence imaging and phosphorescence lifetime imaging. Ir-ImNO was used to monitor the immune activation of macrophages in mice. This technology aims to provide a clear and comprehensive visualization of macrophage immune responses.

A Mitochondria-Localized Iridium(III) Complex for Simultaneous Two-Photon Phosphorescence Lifetime Imaging of Downstream Products N2O3 and ONOO- of Endogenous Nitric Oxide.

Nitric oxide (NO) serves as a ubiquitous and fundamental signaling molecule involved in intricate effects on both physiological and pathological processes. NO, biosynthesized by nitric oxide synthase (NOS) or generated from nitrite, can form nitrosation reagent N2O3 (4NO + O2 = 2N2O3) through its oxidation or quickly produce peroxynitrite anion ONOO- (NO + •O2- = ONOO-) by reacting with superoxide anion (•O2-). However, most of the existing luminescent probes for NO just focus on specificity and utilize only a single signal to distinguish products N2O3 or ONOO-. In most of the present work, they differentiate one product from another simply by fluorescence signal or fluorescence intensity, which is not enough to distinguish accurately the behavior of NO in living cells. Herein, a new mitochondria-targeted and two-photon near-infrared (NIR) phosphorescent iridium(III) complex, known as Ir-NBD, has been designed for accurate detection and simultaneous imaging of two downstream products of endogenous NO, i.e., N2O3 and ONOO-. Ir-NBD exhibits a rapid response to N2O3 and ONOO- in enhanced phosphorescence intensity, increased phosphorescence lifetime, and an exceptionally high two-photon cross-section, reaching values of 78 and 85 GM, respectively, after the reaction. Furthermore, we employed multiple imaging methods, phosphorescence intensity imaging, and phosphorescence lifetime imaging together to image even distinguish N2O3 and ONOO- by probe Ir-NBD. Thus, coupled with its excellent photometrics, Ir-NBD enabled the detection of the basal level of intracellular NO accurately by responding to N2O3 and ONOO- in the lipopolysaccharide-stimulated macrophage model in virtue of fluorescence signal and phosphorescence lifetime imaging, revealing precisely the endogenous mitochondrial NO distribution during inflammation in a cell environment.

N6-methyladenosine modification participates in neoplastic immunoregulation and tumorigenesis.

This review aims to provide insight into the role of N6-methyladenosine (m6A) modification in neoplastic immunity and subsequent tumorigenesis. m6A modification, which is catalyzed by methyltransferases, demethylases and reader proteins, has emerged as a widespread regulatory mechanism that controls immune-related gene expression and immune reactions during tumorigenesis. Aberrant m6A modification changes the neoplastic immune response in multiple cancers by regulating immune cell infiltration, tumor-promoting inflammation, immunosuppression, immune surveillance, and antitumor immune responses. m6A modification affects immune cell recruitment and cancer-promoting inflammation in hepatocellular carcinoma (HCC) to alter the progression of HCC. m6A modification has been implicated in the infiltration of immune cells and the activation of immune pathways, changing the proliferation and metastasis of gastric cancer. Immune surveillance and the antitumor immune response in breast cancer were enhanced via m6A modification, which inhibited tumor proliferation. m6A modification participates in neoplastic immunoregulation to influence tumor progression.

Polariton enhanced free charge carrier generation in donor-acceptor cavity systems by a second-hybridization mechanism.

Cavity quantum electrodynamics has been studied as a potential approach to modify free charge carrier generation in donor-acceptor heterojunctions because of the delocalization and controllable energy level properties of hybridized light-matter states known as polaritons. However, in many experimental systems, cavity coupling decreases charge separation. Here, we theoretically study the quantum dynamics of a coherent and dissipative donor-acceptor cavity system, to investigate the dynamical mechanism and further discover the conditions under which polaritons may enhance free charge carrier generation. We use open quantum system methods based on single-pulse pumping to find that polaritons have the potential to connect excitonic states and charge separated states, further enhancing free charge generation on an ultrafast timescale of several hundred femtoseconds. The mechanism involves polaritons with optimal energy levels that allow the exciton to overcome the high Coulomb barrier induced by electron-hole attraction. Moreover, we propose that a second-hybridization between a polariton state and dark states with similar energy enables the formation of the hybrid charge separated states that are optically active. These two mechanisms lead to a maximum of 50% enhancement of free charge carrier generation on a short timescale. However, our simulation reveals that on the longer timescale of picoseconds, internal conversion and cavity loss dominate and suppress free charge carrier generation, reproducing the experimental results. Thus, our work shows that polaritons can affect the charge separation mechanism and promote free charge carrier generation efficiency, but predominantly on a short timescale after photoexcitation.

Wideband Filtering Slot Antenna Design with Stable Gain Using Characteristic Mode Analysis.

A filtering slot antenna with a simple structure combination using characteristic mode analysis (CMA) is proposed. To realize filtering characteristics, characteristic magnetic currents of line and ring slots are analyzed and designed. Then, the folding-line slot and double-ring slot are selected to realize radiation null separately and combined to construct the basic slot antenna. By properly exciting the selected characteristic modes, a wide filtering bandwidth and a stable gain are obtained. To validate the design process, a prototype antenna with a finite ground plane of about 1.1 λ × 1.1 λ is designed and fabricated. Simulated and measured results agree well, which both show a sharping roll rate in the lower and higher frequency and a flat gain realization in the pass band. The filtering bandwidth is 32.7%, the out-of-band suppression level at the higher frequency is over 20 dB, and the gain in the working frequency varies from 3.9 to 5.2 dB.

Mitochondria-Targeting and Reversible Near-Infrared Emissive Iridium(III) Probe for in vivo ONOO-/GSH Redox Cycles Monitoring.

Peroxynitrite (ONOO-) and glutathione (GSH), two unique reactive species, play an essential regulating role in the oxidation and antioxidation in the living body and are closely associated with various physiological and pathological processes, like cancer, cardiovascular disorders, diabetes, inflammation, Alzheimer's disease, and hepatotoxicity. Thus, it is crucial to study mitochondria ONOO-/GSH redox cycles by an effective molecular tool. In this work, a mitochondria-targeting and redox-reversible near-infrared (NIR) phosphorescent iridium complex, Ir-diol, has been synthesized and used for the detection and imaging of a cellular redox state by visualizing endogenous ONOO-/GSH content. Ir-diol shows excellent photophysical properties, including NIR emission (the maximum emissive wavelength for 704 nm, approximately) and high phosphorescent quantum yield (Φ = 0.136) and exhibits high sensitivity and selectivity toward ONOO-/GSH redox cycles in aqueous solution and living cells. Therefore, these features, combined with low cytotoxicity and excellent cell permeability, enable probe Ir-diol to monitor the changes of the intracellular ONOO-/GSH level induced by drug both in vitro and in vivo.

A Multispectral Photoacoustic Tracking Strategy for Wide-Field and Real-Time Monitoring of Macrophages in Inflammation.

Inflammation is a common defensive response of the vascular system that involves the activation and mediation of immune cell and stem cell homing. However, it is usually hard to track and analyze the real-time status of these cell types toward the inflammation microenvironment in a large field of view with desired resolution. Here, we designed and synthesized near-infrared absorbing semiconducting polymer nanoparticles, BBT-TQP-NP (BTNPs), as the cell tracker and utilized their photoacoustic activity to unveil the targeting behaviors of macrophages, neutrophils, and mesenchymal stem cells to the inflamed sites in mice. Facilitated by multispectral optical-resolution photoacoustic microscopy (ORPAM), we can continuously monitor the in vivo photoacoustic signals of the labeled cells with cellular resolution in a wide-field (a circle field-of-view with a diameter of 9 mm). In addition, the highly sensitive observation of vascular microstructures and labeled cells can reveal the time-dependent accumulating behaviors of various cell types toward inflammation sites. As a result, our study offers an effective and promising tracking strategy to analyze the in vivo status and fate of functional cells in targeting the diseased/damaged regions.

CHFR-mediated degradation of RNF126 confers sensitivity to PARP inhibitors in triple-negative breast cancer cells.

Ring-finger protein 126 (RNF126), an E3 ubiquitin ligase, plays crucial roles in various biological processes, including cell proliferation, DNA damage repair, and intracellular vesicle trafficking. Whether RNF126 is modulated by posttranslational modifications is poorly understood. Here, we show that PARP1 interacts with and poly(ADP)ribosylates RNF126, which then recruits the PAR-binding E3 ubiquitin ligase CHFR to promote ubiquitination and degradation of RNF126. Moreover, RNF126 is required for the activation of ATR-Chk1 signaling induced by either irradiation (IR) or a PARP inhibitor (PARPi), and depletion of RNF126 increases the sensitivity of triple-negative breast cancer (TNBC) cells to PARPi treatment. Our findings suggest that PARPi-mediated upregulation of RNF126 protein stability contributes to TNBC cell resistance to PARPi. Therefore, targeting the E3 ubiquitin ligase RNF126 may be a novel treatment for overcoming the resistance of TNBC cells to PARPi in clinical trials.

Robust Packing of a Self-Assembling Iridium Complex via Endocytic Trafficking for Long-Term Lysosome Tracking.

Live cell imaging of lysosome positioning and motility is critical to studying lysosome status and function for pharmacological interventions. To create a super stable lysosomal probe for long-term live cell imaging, we have designed and synthesized an aromatic-peptide-conjugated cyclometalated iridium(III) complex that emits light via π-π stacking oriented self-assembly in water at extremely low concentration. Through endocytic trafficking, self-assemblies are transformed from nanoparticles into sturdily packed networks that are stabilized in lysosomal acidic environment. Upon short time/low dose treatment of the iridium complex at passage 0, live cell lysosomal tracking is applicable beyond the 14th passage of cells with high labelling rate and a mild decline in luminescence intensity. The illuminated lysosomes are trackable using super-resolution imaging to study their response to cellular processes.

Lysosome-Targeting Iridium(III) Probe with Near-Infrared Emission for the Visualization of NO/O2•- Crosstalk via In Vivo Peroxynitrite Imaging.

Nitric oxide (NO) and superoxide anions (O2•-) are two noteworthy reactive species implicated in various physiological and pathological processes, such as ROS-induced lysosomal cell death. The interaction ("crosstalk") between them may form a new mediator peroxynitrite (ONOO-) which has implications for cancer, diabetes, Alzheimer's disease, and liver-damage. It is therefore essential to investigate lysosomal NO/O2•- crosstalk in vivo through ONOO--responsive molecular tools in order to fully comprehend the physiological and pathological mechanisms involved. In this study, a lysosome-targeting iridium(III) complex, Ir-NIR, has been investigated as a near-infrared (NIR) phosphorescent probe for visualizing NO/O2•- crosstalk by the phosphorescent detection of endogenous ONOO- levels in vivo. Ir-NIR exhibits a rapid (within 200 s), highly sensitive, and approximately 100-fold enhanced response to ONOO- in phosphorescence intensity. Thus, these characteristics, coupled with good cell permeability and low cytotoxicity, enable the probe to be used to detect intracellular ONOO- living organisms both in vitro and in vivo.

Fra-1 plays a critical role in angiotensin II-induced vascular senescence.

Vascular aging has a strong relationship with cardiovascular disease. Fos-related antigen 1 (Fra-1), also referred to as Fos-like antigen 1, is a transcription factor and has been reported to be involved in many pathologic processes. Here, we demonstrate that Fra-1 plays a critical role in angiotensin II (Ang II)-induced vascular senescence. Fra-1 expression is increased significantly in Ang II-induced rat aortic endothelial cell (RAEC) senescence and the arteries from Ang II-infused mice. Interestingly, silencing Fra-1 blocks Ang II-induced senescence phenotypes in RAECs, including decreased senescence-associated ß-galactosidase staining, and mitigated proliferation suppression and senescence-associated secretory phenotype. Further, knocking down Fra-1 inhibits vascular aging phenotypes in an Ang II-infused mice model. The up-regulated Fra-1 also exists in human atherosclerotic plaques and Ang II-induced vascular smooth muscle cells as well as in replicated senescence RAECs. Mechanistic studies reveal that Fra-1 preferentially associates with c-Jun and binds to the cyclin-dependent kinase inhibitor 1a (p21) and cyclin-dependent kinase inhibitor 2a (p16) promoter region, leading to elevated gene expression, which causes senescence-related phenotypes. In conclusion, our results identify that Fra-1 plays a novel and key role in promoting vascular aging by directly binding and transcriptionally activating p21 and p16 signaling, suggesting intervention of Fra-1 is a potential strategy for preventing aging-associated cardiovascular disorders.-Yang, D., Xiao, C., Long, F., Wu, W., Huang, M., Qu, L., Liu, X., Zhu, Y. Fra-1 plays a critical role in angiotensin II-induced vascular senescence.

LncRNA SNHG1 exerts a protective role in cardiomyocytes hypertrophy via targeting miR-15a-5p/HMGA1 axis.

Heart failure preceded by pathological cardiac hypertrophy is a leading cause of death. Long noncoding RNA small nucleolar RNA host gene 1 (SNHG1) was reported to inhibit cardiomyocytes apoptosis, but the role and underlying mechanism of SNHG1 in pathological cardiac hypertrophy have not yet been understood. This study was designed to investigate the role and molecular mechanism of SNHG1 in regulating cardiac hypertrophy. We found that SNHG1 was upregulated during cardiac hypertrophy both in vivo (transverse aortic constriction treatment) and in vitro (phenylephrine [PE] treatment). SNHG1 overexpression attenuated the cardiomyocytes hypertrophy induced by PE, while SNHG1 inhibition promoted hypertrophic response of cardiomyocytes. Furthermore, SNHG1 and high-mobility group AT-hook 1 (HMGA1) were confirmed to be targets of miR-15a-5p. SNHG1 promoted HMGA1 expression by sponging miR-15a-5p, eventually attenuating cardiomyocytes hypertrophy. There data revealed a novel protective mechanism of SNHG1 in cardiomyocytes hypertrophy. Thus, targeting of SNHG1-related pathway may be therapeutically harnessed to treat cardiac hypertrophy.

Bimodal Visualization of Endogenous Nitric Oxide in Lysosomes with a Two-Photon Iridium(III) Phosphorescent Probe.

Nitric oxide (NO) is a fundamental signaling molecule that shows complex effects on the catabolic autophagy process, which is closely linked with lysosomal function. In this study, a new lysosome-targeted, pH-independent, and two-photon phosphorescent iridium(III) complex, Ir-BPDA, has been investigated for endogenous NO detection and imaging. The rational design of the probe, as the addition of the morpholine moieties and the substitution of a benzyl group in the amino group in Ir-BPDA, facilitates its accumulation in lysosomes and makes the reaction product with NO, Ir-BPDA-NO, insusceptible in its phosphorescence intensity and lifetime against pH changes (pH 4-10), well suited for lysosomal NO detection (pH 4-6). Furthermore, Ir-BPDA exhibits a fast and 50-fold response to NO in phosphorescence intensity and a two-photon cross-section as high as 60 GM after the reaction, as well as a notably increased phosphorescence lifetime from 200.1 to 619.6 ns. Thus, accompanied by its photostability, Ir-BPDA enabled the detection of NO in the lipopolysaccharide-stimulated macrophages and zebrafish model, revealing the endogenous lysosomal NO distribution during inflammation in vivo by means of both TPM and PLIM imaging techniques.

Urinary Exosomes and Exosomal CCL2 mRNA as Biomarkers of Active Histologic Injury in IgA Nephropathy.

IgA nephropathy (IgAN) features variable renal pathology and a heterogeneous clinical course. Our aim was to search noninvasive biomarkers from urinary exosomes for IgAN patients; membrane nephropathy and minimal change disease were included as other glomerulopathy controls. Transmission electron microscopy and nanoparticle tracking analysis confirmed the size and morphology characteristic of urinary exosomes. Exosome markers (Alix and CD63) as well as renal cell markers [aquaporin 2 (AQP2) and nephrin] were detected, which indicate the renal origin of urinary exosomes. Exosome excretion was increased markedly in IgAN patients compared with controls and correlated with levels of proteinuria and tubular injury. More important, urinary exosome excretion correlated with greater histologic activity (mesangial hypercellularity, crescents, and endocapillary hypercellularity). Profiling of the inflammation-related mRNA revealed that exosomal chemokine (C-C motif) ligand 2 (CCL2) was up-regulated in IgAN patients. In a validation study, CCL2 was exclusively highly expressed in IgAN patients compared with healthy controls as well as minimal change disease and membrane nephropathy patients. Also, a correlation between exosomal CCL2 and estimated glomerular filtration rate levels was found in IgAN. Exosomal CCL2 was correlated with tubulointerstitial inflammation and C3 deposition. High CCL2 levels at the time of renal biopsy were associated with subsequent deterioration in renal function. Thus, urinary exosomes and exosomal CCL2 mRNA are promising biomarkers reflecting active renal histologic injury and renal function deterioration in IgAN.

Histone demethylase JMJD3 regulates fibroblast-like synoviocyte-mediated proliferation and joint destruction in rheumatoid arthritis.

Rheumatoid arthritis (RA) is an immune-mediated disease with the characteristics of progressive joint destruction, deformity, and disability. Epigenetic changes have been implicated in the development of some autoimmune disorders, resulting in an alteration of gene transcription. Here, we investigated how Jumonji C family of histone demethylases (JMJD3) regulated the proliferation and activation of fibroblast-like synoviocytes (FLSs), which are involved in RA joint destruction and pathologic process. The JMJD3 expression and proliferation markers in RA-FLS were higher than those in healthy-FLS and were upregulated in platelet-derived growth factor (PDGF)-induced FLS. Elevated JMJD3 promoted the proliferation and migration of FLS. Treatment with JMJD3 small interfering RNA or inhibitor glycogen synthase kinase (GSK) J4 led to decreased proliferation and migration of FLS. Interestingly, induction of proliferating cell nuclear antigen (PCNA), a major player of the cell-cycle regulation, was correlated with trimethylated lysine 27 in histone H3 loss around the gene promoters. The knockdown of JMJD3 abolished PCNA expression in PDGF-induced FLS and further inhibited cell proliferation and migration, suggesting that JMJD3/PCNA played a crucial role in aspects of FLS proliferation and migration. In vivo, the ability of GSK J4 to hinder collagen-induced arthritis (CIA) in DBA/1 mice was evaluated. We found that GSK J4 markedly attenuated the severity of arthritis in CIA mice. The therapeutic effects were associated with ameliorated joint swelling and reduced bone erosion and destruction. This study revealed how JMJD3 integrated with epigenetic processes to regulate RA-FLS proliferation and invasion. These data suggested that JMJD3 might contribute to rheumatoid synovial hyperplasia and have the potential as a novel therapeutic target for RA.-Jia, W., Wu, W., Yang, D., Xiao, C., Su, Z., Huang, Z., Li, Z., Qin, M., Huang, M., Liu, S., Long, F., Mao, J., Liu, X., Zhu, Y. Z. Histone demethylase JMJD3 regulates fibroblast-like synoviocyte-mediated proliferation and joint destruction in rheumatoid arthritis.

Exosomal CCL2 from Tubular Epithelial Cells Is Critical for Albumin-Induced Tubulointerstitial Inflammation.

Albuminuria is a key instigator of tubulointerstitial inflammation associated with CKD, but the mechanism through which filtered albumin propagates renal injury remains unclear. In this study, we explored the role in this process of exosome mRNA released from tubular epithelial cells (TECs). Compared with control mice, acute and chronic kidney injury models had more exosomes containing inflammatory cytokine mRNA, particularly the chemokine CCL2, in kidneys and urine. In vitro stimulation of TECs with BSA recapitulated this finding. Notably, the internalization of purified TEC exosomes by cultured macrophages increased if TECs were exposed to BSA. Macrophage internalization of exosomes from BSA-treated TECs led to an enhanced inflammatory response and macrophage migration, but CCL2 silencing in TECs prevented these effects. Using a GFP-CCL2 fusion mRNA construct, we observed direct transfer of CCL2 mRNA from TEC exosomes to macrophages. Mice subjected to tail vein injection of purified BSA-treated TEC exosomes developed tubular injury with renal inflammatory cell infiltration. However, injection of exosomes from BSA-treated CCL2-deficient TECs induced less severe kidney inflammation. Finally, in patients with IgA nephropathy, the increase of proteinuria correlated with augmented urinary excretion of exosomes with exaggerated expression of CCL2 mRNA. Moreover, the level of CCL2 mRNA in urinary exosomes correlated closely with levels of renal interstitial macrophage infiltration in these patients. Our studies demonstrate that the increasing release of exosomes that transfer CCL2 mRNA from TECs to macrophages constitutes a critical mechanism of albumin-induced tubulointerstitial inflammation.

Therapeutic application of extracellular vesicles in kidney disease: promises and challenges.

Extracellular vesicles (EVs) are nanosized, membrane-bound vesicles released from different cells. Recent studies have revealed that EVs may participate in renal tissue damage and regeneration through mediating inter-nephron communication. Thus, the potential use of EVs as therapeutic vector has gained considerable interest. In this review, we will discuss the basic characteristics of EVs and its role in nephron cellular communication. Then, the application of EVs as therapeutic vector based on its natural content or as carriers of drug, in acute and chronic kidney injury, was discussed. Finally, perspectives and challenges of EVs in therapy of kidney disease were described.

Endogenous Hydrogen Sulfide Ameliorates NOX4 Induced Oxidative Stress in LPS-Stimulated Macrophages and Mice.

BACKGROUND/AIMS: Sepsis is a severe and complicated syndrome that is characterized by dysregulation of host inflammatory responses and organ failure. Cystathionine-γ-lyase (CSE)/ hydrogen sulfide (H2S) has potential anti-inflammatory activities in a variety of inflammatory diseases. NADPH oxidase 4 (Nox4), a member of the NADPH oxidases, is the major source of reactive oxygen species (ROS) and its expression is increased in sepsis, but its function in CSE-mediated anti-inflammatory activities remains unknown. METHODS: Macrophages were either transfected with CSE, Nox4 siRNA or transduced with lentiviral vector encoding CSE or Nox4, and then stimulated with lipopolysaccharide (LPS). The expression of inflammatory mediators and signaling pathway activation were measured by quantitative PCR (qPCR), ELISA, and immunoblotting. LPS-induced shock severity in WT, Nox4 knockdown and CSE knockout (CSE-/-) mice was assessed. RESULTS: Here we showed that CSE and Nox4 were upregulated in macrophage and mouse in response to LPS. After LPS stimulation, the inflammatory responses were significantly ameliorated by lentiviral Nox4 shRNA knockdown, but were exacerbated by lentiviral overexpressing Nox4. Furthermore, Nox4 mediated inflammation through PI3K/Akt and p-p38 mitogen-activated protein kinase signal pathway. Notably, CSE knockout served to amplify the inflammatory cascade by increasing Nox4-ROS signaling activation in septic mice and macrophage. Similarly, the enhanced production of inflammatory mediators by macrophages was reduced by CSE overexpression. CONCLUSION: Thus, we demonstrated that CSE/H2S attenuated LPS-induced sepsis against oxidative stress and inflammation damage probably largely through mediated Nox4 pathway.