Rationale:Deciphering the molecular consequences of protein cleavage in inflammatory signaling is vital for defining the mechanisms of intestinal autoinflammation and identifying new therapeutic targets for inflammatory bowel disease (IBD). While it was previously established that HOIL-1 cleavage by MALT1 negatively regulates NF-κB activation and inflammatory responses in vitro, the pathophysiological role of HOIL-1 cleavage in regulating intestinal inflammation and the specific function of the resulting C-terminal fragment (C-HOIL-1) remained elusive. This study aimed to define the role of HOIL-1 cleavage and C-HOIL-1 in modulating gut inflammation. Methods:To investigate the impact of HOIL-1 cleavage on intestinal inflammation, the global and myeloid-specific transgenic mouse models with uncleavable HOIL-1 (lacking C-HOIL-1) were established, and their disease phenotypes and immune profiles were characterized under DSS-induced colitis. Genetically engineered THP-1 monocytic cells expressing uncleavable HOIL-1 and C-HOIL-1 were constructed to elucidate the molecular mechanisms of C-HOIL-1 in regulating inflammatory signaling. Finally, Lenti-C-HOIL-1 was delivered to the colon of wild-type mice via enema to evaluate the therapeutic potential of C-HOIL-1 in controlling intestinal inflammation. Results:Mice with uncleavable HOIL-1 (lacking C-HOIL-1) present a more severe disease phenotype in DSS-induced colitis; specifically, the infiltration of inflammatory monocytes, M1-type macrophages, and neutrophils is significantly elevated in the colon. Mechanistically, we discover that C-HOIL-1 has novel biological functions in i) inhibiting NF-κB signaling, ii) interacting with STAT1 to down-regulate STAT1-mediated inflammatory signaling, and iii) up-regulating ARG1 expression. Collectively, these actions suppress the inflammatory responses in monocytes/macrophages, and impede the differentiation of M1-type macrophages. The pretreatment of Lenti-C-HOIL-1 to the colon of wild-type mice alleviates DSS-induced intestinal inflammation. Conclusions:Our results define the pathophysiological role of HOIL-1 cleavage in colitis, and unveil new functions of C-HOIL-1 in regulating myeloid inflammatory responses. These findings provide a potential therapeutic strategy for controlling gut inflammation in IBD.

Background:Modulating the cGAS-STING pathway by bioactive nanodevices is a promising strategy for combating infection-associated inflammatory disorders. However, the development of pharmacological inhibitors for cGAS-STING signaling is currently hindered by lacking cell-specific targeting capability. This study aimed to develop a potent, drug-free nanodevice that specifically targets pulmonary macrophages to modulate the cGAS-STING pathway for ameliorating infection-associated detrimental lung inflammation. Methods:Cigarette smoke extract-modified peptide gold nanoparticle hybrids (CSE-P12) were synthesized. Transcriptomic analysis, western blotting, autophagy reporter assays, and confocal microscopy were employed to assess the effects of CSE-P12 on gene expression, STING degradation, autophagic flux, and inflammation. TEM imaging and LC-MS/MS were utilized to elucidate the molecular mechanisms underlying CSE-P12-induced autophagy in macrophages. Finally, the HAdV4-induced pneumonia and CLP-induced sepsis models on wild-type and STING-/- mice were used to evaluate the therapeutic efficacy of CSE-P12 and validate its inhibitory mechanisms on the cGAS-STING pathway. Results:CSE-P12 nanodevices are extensively internalized by macrophages via energy-dependent cellular uptake. This large internalization triggers autophagic degradation of STING, thereby effectively inhibiting the cGAS-STING-mediated interferon responses and inflammation. In the HAdV4-induced viral pneumonia mouse model, intratracheally instilled CSE-P12 effectively targets pulmonary macrophages, suppresses STING activation, and significantly alleviates lung inflammation and injury. The depletion of the pulmonary macrophages abolishes these protective effects. The therapeutic potential of CSE-P12 is further validated in a CLP-induced polymicrobial sepsis mouse model, where it significantly prolongs mouse survival and decreases lung inflammation. Conclusions:CSE-P12 effectively targets pulmonary macrophages and exhibits potent anti-inflammatory activities in viral pneumonia and sepsis-induced acute lung injury by inducing autophagic flux to facilitate STING degradation. This work provides a new paradigm for designing targeted nanotherapeutics to modulate STING activation in inflammatory diseases.

Abnormal expression of miRNAs is associated with the occurrence and progression of cancer and other diseases, making miRNAs essential biomarkers for disease diagnosis and prognosis. However, the intrinsic properties of miRNAs, such as short length, low abundance, and high sequence homology, represent great challenges for fast and accurate miRNA detection in clinics. Herein, we developed a novel hybridization chain reaction (HCR)-based electrochemical miRNAs chip (e-miRchip), featured with gold nanostructured electrodes (GNEs) and silver nanoparticle reporters (AgNRs), for sensitive and multiplexed miRNA detection. AgNRs were synthesized and applied on the e-miRchip to generate strong redox signals in the presence of miRNA. The stem–loop capture probe was covalently immobilized on the GNEs, and was opened upon miRNA hybridization to consequently trigger the HCR for signal amplification. The multiple long-repeated DNA helix generated by HCR provides the binding sites for the AgNRs, contributing to the amplification of the electrochemical signals of miRNA hybridization. To optimize the detection sensitivity, GNEs with three distinct structures were electroplated, in which flower-like GNEs were found to be the best electrode morphology for miRNAs analysis. Under optimal conditions, the HCR-based e-miRchip showed an excellent detection performance with an LOD of 0.9 fM and a linear detection range from 1 fM to 10 pM. Moreover, this HCR-based e-miRchip platform was able to effectively distinguish miRNAs from the one- or two-base mismatches. This HCR-based e-miRchip holds great potential as a highly efficient and promising miRNA detection platform for the diagnosis and prognosis of cancer and other diseases in the future.

The overactivation of endosomal Toll-like receptor (TLR) in macrophages plays an important role in the pathogenesis of acute lung injury (ALI). There is currently still a lack of nano-formulated and macrophage-targeted endosomal TLR inhibitors that have been approved for clinical uses. We previously discovered that the elevation of endosomal pH using nanodevices provides a promising strategy to specifically inhibit endosomal TLRs in macrophages. The weakly basic drug hydroxychloroquine (HCQ) has been reported for its capability to accumulate in endolysosomes and modulate the acidity in these compartments. To enhance its macrophage-targeting ability and the therapeutic efficacy in vivo, herein we formulated HCQ into a nanoform using liposomes, named HCQ-L. We found that HCQ-L was less cytotoxic and more effective in inhibiting endosomal TLRs (including TLR3, TLR4, TLR 7/8) than the molecular HCQ. Subsequently, a hexapeptide, Pep12, was inserted onto the surface of HCQ-L to form HCQ-L-P12. Interestingly, Pep12 modification significantly improved the stability of liposomes in aqueous solution for at least 2 years; while having enhanced inhibitory effects on TLR7/8 signaling, HCQ-L-P12 displayed similar effects on inhibiting the TLR4 pathway and down-stream pro-inflammatory cytokine production when compared with HCQ-L. Furthermore, both HCQ nanoformulations potently elevated the endosomal pH. In vivo evaluation showed that HCQ-L-P12 and HCQ-L (but not molecular HCQ) were able to alleviate lung inflammation and injuries by decreasing inflammatory cell infiltration upon intratracheal instillation in a lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model. This research provides a new strategy to fabricate lipid-based nanocarriers for targeted delivery of endosomal pH modulators to treat ALI and other acute and chronic inflammatory disorders.

Background: Diabetic retinopathy (DR) is a vision-threatening microvascular complication of diabetes mellitus. Chronic inflammation and endothelial dysfunction are critical factors in the disease's pathogenesis. Consequently, interventions developed to reduce retinal inflammation are anticipated to be beneficial for both the prevention and treatment of DR. In the present study, we developed a unique class of drugless peptide-based nanohybrids with potent anti-inflammatory activities and investigated their therapeutic efficacy for treating DR in an oxygen-induced retinopathy (OIR) mouse model and a streptozotocin (STZ)-induced diabetic mouse model. Methods: Hexapeptides were applied to modify gold nanoparticles to form the drugless peptide-based nanohybrids (P12). We then examined the physicochemical properties and anti-inflammatory activities of P12 in HUVECs and BV2 cells and identified the critical amino acids for this novel bioactivity. The intravitreal and retro-orbital injections were applied to determine the optimal retinal delivery route for P12. The therapeutic efficacy of P12 in treating DR were investigated using both the OIR model and STZ-induced diabetic model. Through immunohistochemistry and flow cytometry analyses, we identified the major cells that internalize P12 in the retina. Furthermore, in vitro experiments were used to explore the underlying molecular mechanisms for the anti-inflammatory activities of P12. Results: We found that P12 exhibited potent anti-inflammatory effects in both HUVECs and BV2 cells. In addition, P12 can be efficiently delivered to the retina via intravitreal injection. Intravitreally injected P12 significantly improved early DR symptoms including vascular leakage and pericyte loss in STZ-induced diabetic mice. It also suppressed pathological neovascularization and retinal hemorrhage in OIR mice. Importantly, we found that intravitreally injected P12 was mainly taken up by microglial and endothelial cells, leading to reduced retinal endothelium inflammation and microglial activation in DR animal models. Mechanistic studies revealed that P12 potently inhibited several TLR4 downstream signaling pathways, such as NF-κB, JNK, and P38 MAPK, in both endothelial and microglial cells. This effect is due to the capacity of P12 in blocking the endosomal acidification process that governs the endosomal TLR signaling transduction. Conclusions: Our findings suggest that local injection of properly designed, drugless, peptide-based nanohybrids can serve as a safe and effective anti-inflammatory nanomedicine for treating DR.

Sepsis-induced systemic inflammatory responses can often lead to brain dysfunction with impaired cognitive function and mobility, known as sepsis-associated encephalopathy (SAE). Currently, there are no effective pharmacological therapeutics to treat SAE. Herein, we demonstrated the hexapeptide functionalized gold nanoparticles P12 that reduced SAE in septic mice with a dual mechanism to down-regulate systemic inflammation. We found that intraperitoneally administered P12 could target macrophages and regulate their inflammatory responses to decrease systemic inflammation and improve mice's cognitive function and mobility with SAE. Depleting peritoneal macrophages diminished the neuroprotective effects of P12 in SAE mice, suggesting macrophages as the effector cells for the neuroprotection by P12. In addition, the proteomic analysis revealed that P12 was capable of sequestering specific circulating inflammatory proteins in the blood of septic mice by forming a protein corona, contributing to the suppression of systemic inflammation. We also found that the local administration of P12 directly to the brain parenchyma effectively inhibited microglia activation and neuroinflammation in mice with SAE. This study provides an insightful understanding of the function and mechanisms of action of P12 in regulating sepsis-associated systemic inflammation and presents a new drug-free nanotherapeutic approach to treat SAE.

Abstract Background Gastrointestinal (GI) diseases are rising in Western societies, alongside environmental changes like reduced exposure to ultraviolet (UV) B light. UVB light affects the skin through vitamin D (vitD) and Aryl hydrocarbon receptor (Ahr) signaling, but its potential influence on distant sites, like the gut, is not well studied, despite GI and skin diseases often co-occurring (O’Neill et al, 2016). Patients not only suffer from GI symptoms but also may experience various mood disorders such as anxiety and depression (Graff et al, 2009). We aimed to explore how UVB skin exposure influences gut health, microbiota and its metabolic by-products, and hypothesize that UVB may also affect the gut-brain axis, influencing mood and cognition. Aims Test the (1) effect of UVB light using vitD deficient (-) and sufficient (+) diets on the metabolomic profile and gut microbiome, and (2) the impact of vitD levels and UVB on susceptibility to Citrobacter rodentium infection. Methods Female C57BL/6J mice were fed either vitD (+) or (-) diets. They were anaesthetized, and then 8 cm2 of their dorsal skin was shaved and exposed to UVB. Mice were euthanized to collect serum, cecal content, and stool (FI-ToF metabolomics analysis and 16S sequencing). Ingenuity Pathway Analysis (IPA) was used to predict the impact of metabolic changes. Mice were infected by oral gavage using 2x108 colony-forming units of WT C. rodentium, monitored daily and euthanized on day 10 post-infection. Samples (cecum, colon, and stool) were collected for CFU, histology, immunostaining, and qPCR analysis. Results In vitD (-) fed mice, UVB skin exposure raised vitD levels to match those on vitD (+) diets. Untargeted metabolomics detected ~1,630 stool metabolites at baseline, and following one UVB exposure, 266 metabolites changed in the vitD (-) group, 297 in the vitD (+), with 47 overlapping. After 6 exposures, 449 metabolites changed in the vitD (-) group, 138 in the vit D (+), with 61 overlapping. Pathway analysis revealed significant alterations in purine, tryptophan, and alanine-aspartate-glutamate metabolism. IPA determined that changes in these pathways in the vitD (-) group were associated with mood disorders and colorectal tumor inhibition. 16S microbiome analysis showed changes in the Bacteroidota phylum. Finally, vitD (-) group showed increased susceptibility to C. rodentium infection, while UVB light skin exposure reduced intestinal pathology in the vitD (-) group, suggesting a protective role of UVB light against intestinal infection. Conclusions The study demonstrates that UVB exposure significantly alters the GI metabolome and microbiome, with a greater impact in vitD (-) mice. These findings highlight the complex interplay between UVB exposure, vitD status, and host metabolism and immunity. Funding Agencies NSERC

Inflammatory bowel disease (IBD) has become a serious and challenging health problem globally without curative medical treatments. Mounting evidence suggests that intestinal macrophages and their phenotypes are key players in the pathogenesis of IBD. Modulating the phenotypes and functions of intestinal macrophages through targeted interventions could be a promising approach to manage detrimental gut inflammation in IBD. In this study, we rationally design and fabricate a novel class of V-type peptide-decorated nanoparticles, VP-NP, with potent anti-inflammatory activity. Such a design allows two functional motifs FFD in a single peptide molecule to enhance the bioactivity of the nanoparticles. As expected, VP-NP exhibits a strong inhibitory activity on endosomal Toll-like receptor (TLR) signaling. Surprisingly, VP-NP can inhibit M1 polarization while facilitating M2 polarization in mouse bone marrow-derived macrophages through regulating the key transcription factors NF-κB, STAT1 and PPAR-γ. Mechanistically, VP-NP is internalized by macrophages in the endosomes, where it blocks endosomal acidification to inhibit endosomal TLR signaling; the transcriptomic analysis reveals that VP-NP potently down-regulates many genes in TLR, NF-κB, JAK-STAT, and cytokine/chemokine signaling pathways associated with inflammatory responses. In a colitis mouse model, the intraperitoneally administered VP-NP effectively alleviates the disease activities by decreasing colon inflammation and injuries, pro-inflammatory cytokine production, and myeloid cell infiltration in the gut. Furthermore, VP-NP primarily targets intestinal macrophages and alters their phenotypes from inflammatory M1-type toward the anti-inflammatory M2-type. This study provides a new nanotherapeutic strategy to specifically regulate macrophage activation and phenotypes through a dual mechanism to control gut inflammation, which may augment current clinical treatments for IBD.

Acute respiratory distress syndrome (ARDS) has emerged as a significant global health challenge, with no definitive curative treatment available. Recent evidence suggests that pyroptosis of immune cells plays a pivotal role in the pathogenesis of ARDS. Targeting and modulating immune cell pyroptosis in lung tissue may offer a promising strategy to mitigate the harmful inflammation associated with this condition. In this study, we designed and synthesized a novel class of peptide-functionalized nanoparticles, PV-K, which possess an intrinsic capacity for phagocytosis by macrophages. Concurrently, the incorporation of two FFD functional groups into a single polypeptide enhances the biological activity of PV-K. Amazingly, PV-K demonstrated potent inhibitory effects on nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3)-mediated pyroptosis in both mouse bone marrow-derived macrophages and the human THP-1 cell-derived macrophages. In both lipopolysaccharide and cecal ligation and puncture induced acute lung injury mouse models, treatment with PV-K significantly reduced disease severity by alleviating pulmonary inflammation and inhibiting macrophage pyroptosis. Transcriptomic analysis revealed that PV-K enhanced SQSM1/p62-mediated autophagy through upregulation of the NRF2 signaling pathway. Mechanistically, PV-K facilitated the interaction between SQSTM1/p62 and NLRP3, promoting the autolysosomal degradation of NLRP3. Notably, the inhibitory effect of PV-K on macrophage pyroptosis during acute lung injury was abrogated in Nrf2-/- mice. This study introduces a novel nanotherapeutic approach aiming at regulating macrophage pyroptosis by facilitating NLRP3 degradation, thereby controlling inflammation in ARDS/ALI. This strategy may complement existing clinical treatments for ARDS/ALI.

Multifunctional nanodevices that simultaneously destruct bacteria and control detrimental inflammation are anticipated to serve as an effective therapy for sepsis. Toll-like receptor 2 (TLR2) and TLR4 signaling pathways are pivotal to the pathogenesis of sepsis from the clinical data analysis. Herein, inspired by understanding of the molecular interactions between TLR2/4 and their natural ligands, we de novo design an amphiphilic, helical, cationic peptide R18, which potently inhibits the activation of both TLR2 and TLR4, and eradicates bacteria. Such inhibition is primarily achieved by binding of R18 to TLR2 or to both TLR4 ligand and receptor, which interferes with the ligand-receptor interactions. We also define the essential role of the hydrophobic and cationic amino acid residues in the peptide sequence in these multi-actions. By conjugating R18 to the self-assembled PEGylated phospholipid-based nanomicelles (designated as M-CR18), the antibacterial activity and the stability are significantly enhanced. The mechanistic studies reveal that M-CR18 effectively eliminates bacteria through triple-destruction on bacterial membrane integrity, biofilm formation, and bacterial flagellar assembly when compared with the molecular R18. The in vivo efficacy of M-CR18 is validated in infectious mouse models of cecal ligation and puncture as well as Pseudomonas aeruginosa-induced acute lung injury, and a non-infectious mouse model of lipopolysaccharide (LPS)-induced pulmonary inflammation. Finally, M-CR18 can effectively eliminate clinically present drug-resistant bacteria. This study provides a de novo design principle for multifunctional nanodevices with immunomodulatory and antibacterial activities, which represent a novel class of nano-antibiotics for the treatment of bacterial infection-mediated pneumonia and sepsis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection caused the COVID-19 pandemic, impacting the global economy and medical system due to its fast spread and extremely high infectivity. Efficient control of the spread of the disease relies on a fast, accurate, and convenient detection system for the early screening of the infected population. Although reverse transcription–quantitative polymerase chain reaction (RT-qPCR) is the gold-standard method for SARS-CoV-2 RNA analysis, it has complex experimental procedures and relies on expensive instruments and professional operators. In this work, we proposed a simple, direct, amplification-free lateral flow immunoassay (LFIA) with dual-mode detection of SARS-CoV-2 RNA via direct visualization as well as fluorescence detection. The viral RNA was detected by the designed DNA probes to specifically hybridize with the conserved open reading frame 1ab (ORF1ab), envelope protein (E), and nucleocapsid (N) regions of the SARS-CoV-2 genome to form DNA–RNA hybrids. These hybrids were then recognized by the dual-mode gold nanoparticles (DMNPs) to produce two different readout signals. The fluorescence characteristics of different sizes of GNPs were explored. Under the optimized conditions, the LFIA presented a linear detection range of 104–106 TU/mL with a limit of detection (LOD) of 0.76, 1.83, and 2.58 × 104 TU/mL for lentiviral particles carrying SARS-CoV-2 ORF1ab, E, and N motifs, respectively, in the fluorescent mode, which was up to 10 times more sensitive than the colorimetric mode. Furthermore, the LFIA exhibited excellent specificity to SARS-CoV-2 in comparison with other respiratory viruses. It could be used to detect SARS-CoV-2 in saliva samples. The developed LFIA represents a promising and convenient point-of-care method for dual-mode, rapid detection of SARS-CoV-2, especially in the periods with high infectivity.

In rheumatoid arthritis (RA), macrophages infiltrate joints, while fibroblast-like synovial cells proliferate abnormally, forming a barrier against drug delivery, which hinders effective drug delivery to joint focus. Here we firstly designed a pH-responsive size-adjustable nanoparticle, composed by methotrexate (MTX)-human serum albumin (HSA) complex coating with pH-responsive liposome (Lipo/MTX-HSA) for delivering drugs specifically to inflamed joints in acidic environments. We showed in vitro that the nanoparticles can induce mitochondrial dysfunction, promote apoptosis of fibroblast-like synoviocytes and macrophages, further reduce the secretion of inflammatory factors (TNF-α, IL-1β, MMP-9), and regulate the inflammatory microenvironment. We also demonstrated similar effects in a rat model of arthritis, in which Lipo/MTX-HSA accumulated in arthritic joints, and at low pH, liposome phospholipid bilayer cleavage released small-sized MTX-HSA, which effectively reduced the number of fibroblast-synoviocytes and macrophages in joints, alleviated joint inflammation, and repaired bone erosion. These findings suggest that microenvironment-responsive size-adjustable nanoparticles show promise as a treatment against rheumatoid arthritis.Statement of SignificanceAbnormal proliferation of fibroblast synoviocytes poses a physical barrier to effective nanoparticle delivery. We designed size-adjustable nano-delivery systems by preparing liposomes with cholesterol hemisuccinate (CHEM), which were subsequently loaded with small-sized albumin nanoparticles encapsulating the cytotoxic drug MTX (MTX HSA), termed Lipo/MTX-HSA. Upon tail vein injection, Lipo/MTX-HSA could be aggregated at the site of inflammation via the ELVIS effect in the inflamed joint microenvironment. Specifically, intracellular acidic pH-triggered dissociation of liposomes promoted the release of MTX-HSA, which was further targeted to fibroblasts or across fibroblasts to macrophages to exert anti-inflammatory effects. The results showed that liposomes with adjustable particle size achieved efficient drug delivery, penetration and retention in joint sites; the strategy exerted significant anti-inflammatory effects in the treatment of rheumatoid arthritis by inducing mitochondrial dysfunction to promote apoptosis in fibrosynoviocytes and macrophages.

BACKGROUND:The primary purpose of this study was to demonstrate the preventive effects of imatinib (IMA) on lipopolysaccharide (LPS)-induced inflammation in a mouse model of acute lung injury (ALI) and human umbilical vascular endothelial cells. METHODS:LPS stimulation for 24 h induced ALI and cell inflammation. The pathological results of the lungs were evaluated using the wet/dry weight ratio, pulmonary vascular permeability measurements, and myeloperoxidase immunohistochemistry. The expression of pro-inflammatory mediators was analyzed using RT-PCR and enzyme-linked immunosorbent assay. Protein levels were analyzed using western blotting. The structure of cell junctions was detected using immunofluorescence. RESULTS:IMA improved LPS-induced pulmonary pathological damage and reduced the lung wet/dry weight ratio and myeloperoxidase expression in the lung tissue. IMA decreased bronchoalveolar lavage fluid inflammatory cell count and the release of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and monocyte chemotactic protein 1 (MCP-1) in the blood. Pretreatment of human umbilical vascular endothelial cells with IMA significantly attenuated LPS-induced actin stress fiber formation and vascular endothelial-cadherin disruption. In addition, IMA downregulated the mRNA abundances of vascular cell adhesion molecule 1, intercellular adhesion molecule 1, IL-1β, IL-6, and tumor necrosis factor-α(TNF-α) expression. The phosphorylation of p65, nuclear factor-kappa B inhibitor alpha (IκBα), p38, extracellular signal-regulated kinase, and Jun N-terminal kinase induced by LPS were attenuated after IMA treatment in vivo and in vitro. CONCLUSIONS:IMA modulates the nuclear factor-kappa B and mitogen-activated protein kinase signaling pathways and the production of pro-inflammatory cytokines to prevent cellular damage due to LPS infection. These results indicate that IMA may be a potential modulator of LPS-induced ALI.

Abstract Melanin-like nanoparticles (MNPs) have recently emerged as valuable agents in antioxidant therapy due to their excellent biocompatibility and potent capacity to scavenge various reactive oxygen species (ROS). However, previous studies have mainly focused on acute ROS-related diseases, leaving a knowledge gap regarding their potential in chronic conditions. Furthermore, apart from their well-established antioxidant effects, it remains unclear whether MNPs target other intracellular molecular pathways. In this study, we synthesized ultra-small polyethylene glycol-incorporated Mn2+-chelated MNP (MMPP). We found that MMPP traversed the glomerular filtration barrier and specifically accumulated in renal tubules. Autosomal dominant polycystic kidney disease (ADPKD) is a chronic genetic disorder closely associated with increased oxidative stress and featured by the progressive enlargement of cysts originating from various segments of the renal tubules. Treatment with MMPP markedly attenuated oxidative stress levels, inhibited cyst growth, thereby improving renal function. Interestingly, we found that MMPP effectively inhibits a cyst-promoting gene program downstream of the cAMP-CREB pathway, a crucial signaling pathway implicated in ADPKD progression. Mechanistically, we observed that MMPP directly binds to the bZIP DNA-binding domain of CREB, leading to competitive inhibition of CREB’s DNA binding ability and subsequent reduction in CREB target gene expression. In summary, our findings identify an intracellular target of MMPP and demonstrate its potential for treating ADPKD by simultaneously targeting oxidative stress and CREB transcriptional activity.

Integrin alpha 4 beta 1 and alpha 4 beta 7 are overexpressed in macrophages and leukocytes and play important roles in mediating cell homing and recruitment to inflammatory tissues. Herein, to enhance the targeting ability of nanotherapeutics for inflammatory bowel disease (IBD) treatment, cyclosporine A-loaded nanoparticles (CsA NPs) were coated with macrophage membranes (MM-CsA NPs) or leukocyte membranes (LM-CsA NPs). In vitro experiments demonstrated that the physicochemical properties of the nanotherapeutics (e.g., size, zeta potential, polymer dispersity index, and drug release profiles) did not obviously change after cell membrane coating. However, integrin alpha 4 beta 1 and alpha 4 beta 7 were expressed in MM-CsA NPs and LM-CsA NPs, respectively, which significantly inhibited normal macrophage phagocytosis and obviously increased uptake by proinflammatory macrophages and endothelial cells. In vivo experiments verified that cell membrane-coated nanotherapeutics have longer retention times in inflammatory intestinal tissues. Importantly, LM-CsA NPs significantly mitigated weight loss, alleviated colon shortening, decreased disease activity indices (DAIs), and promoted colon tissue repair in acute and chronic colitis model mice. Furthermore, LM-CsA NPs significantly decreased the expression of inflammatory factors such as TNF-alpha and IL-6 and increased the expression of gut barrier-related proteins such as E-cadherin, ZO-1, and occludin protein in colitis mice.

Background Sepsis is defined as a life-threatening syndrome caused by an unbalanced host response to infection. The role of interleukin (IL)-36 cytokines binding to the IL-36 receptor (IL-36R) in host response during sepsis remains unknown. Methods Serum IL-36 level was measured in 47 septic patients sampled on the day of intensive care unit (ICU) and emergency department admission, 21 non-septic ICU patient controls, and 21 healthy volunteers. In addition, the effects of IL-36R deletion on host inflammatory response in cecal ligation and puncture (CLP)-induced polymicrobial sepsis was determined. Results On the day of ICU and emergency department admission, the patients with sepsis showed a significant increase in serum IL-36 levels compared with ICU patient controls and healthy volunteers, and the serum IL-36 levels were related to the severity of sepsis. Non-survivors of septic patients displayed significantly lower serum IL-36 levels compared with survivors. A high serum IL-36 level in ICU and emergency department admission was associated with 28-day mortality, and IL-36 was found to be an independent predictor of 28-day mortality in septic patients by logistic regression analysis. Furthermore, IL-36R deletion increased lethality in CLP-induced polymicrobial sepsis. Septic mice with IL-36R deletion had higher bacterial load and demonstrated more severe multiple organ injury (including lung, liver, and kidney) as indicated by clinical chemistry and histopathology. Mechanistically, IL-36R ligands released upon lung damage activated IL-36R + lung fibroblasts thereby inducing expression of the antimicrobial protein lipocalin 2. Moreover, they induced the apoptosis of lung epithelial cells. Conclusions Septic patients had elevated serum IL-36 levels, which may correlate with disease severity and mortality. In experimental sepsis, we demonstrated a previously unrecognized role of IL-36R deletion in increasing lethality.

Asthma is a complex, heterogeneous chronic airway inflammatory disorder, which can be simply categorized into eosinophilic and neutrophilic asthma. Although most patients with eosinophilic asthma can be well managed by glucocorticoid therapy, the patients with neutrophilic asthma have poor responses to corticosteroids, and there are no effective clinical treatments for neutrophilic asthma. Studies have shown that M1 macrophages are associated with the pathophysiology of neutrophilic asthma. We previously developed a novel cargo-free anti-inflammatory nanoparticle (P12), which can promote macrophage polarization from M1 to the M2 phenotype. Herein, we aim to explore the therapeutic activities of P12 in eosinophilic asthma and neutrophilic asthma and the mechanisms of action behind. Using the mouse models of eosinophilic and neutrophilic asthma, we found that the intratracheally administered P12 reduced the airway resistance in both models. However, P12 had higher therapeutic effects in neutrophilic asthma than in eosinophilic asthma, particularly on the pathological score, the serum IgE level, the BAL differential cell count and the proinflammatory cytokine IL-17A and IL-6 levels. Mechanistically, P12 facilitated M2 macrophage polarization by inhibiting transcription factors NF-κB and STAT1 activation and up-regulating STAT3 signaling in vitro; in the asthma models, P12 promoted M2 polarization of both alveolar and interstitial macrophages, and reduced the downstream Th17/Treg ratio in mice with neutrophilic asthma. Finally, P12 showed a good biosafety profile in healthy mice, facilitating the clinical translation of P12. This study provides a new strategy and lung macrophage targeted nanotherapeutics for the treatment of neutrophilic asthma.

Excessive activation of Toll‐like receptor (TLR) signaling pathways and the circulating endotoxin are key players in the pathogenesis of many acute and chronic inflammatory diseases. Regulation of TLR‐mediated inflammatory responses by bioactive nanodevices represents a promising strategy for treating these diseases. In searching for novel, clinically applicable nanodevices with potent TLR inhibitory activities, three types of hexapeptide‐modified nano‐hybrids with different cores of phospholipid nanomicelles, liposomes, and poly(lactic‐co‐glycolic acid) nanoparticles are constructed. Interestingly, only the peptide‐modified lipid–core nanomicelles (M‐P12) display potent TLR inhibitory activities. Further mechanistic studies disclose that lipid–core nanomicelles have a generic property to bind to and scavenge lipophilic TLR ligands including lipopolysaccharide to block the ligand–receptor interaction and down‐regulate the TLR signaling extracellularly. In addition, the peptide modification enables M‐P12 a unique capability to modulate endosomal acidification upon being endocytosed into macrophages, which subsequently regulates the endosomal TLR signal transduction. In an acute lung injury mouse model, intratracheal administration of M‐P12 can effectively target lung macrophages and reduce lung inflammation and injuries. This work defines a dual mechanism of action of the peptide‐modified lipid–core nanomicelles in regulating TLR signaling, and provides new strategies for the development of therapeutic nanodevices for treating inflammatory diseases.

As a clinical unmet need, uncontrolled inflammation is characterized by the crosstalk between oxidative stress and an inflammatory response. Ferroptotic cell death plays an essential role in uncontrolled inflammation. Hence ferroptosis inhibition is capable of managing hyper-inflammation, but the small molecular inhibitors show poor residence in cell membranes. The plasma membrane is the major site of lipid peroxidation that is the key event of ferroptosis. To address such a challenge, chiral radical trapping polymers were engineered by mimicking the structure of the cell membrane with imbedded helical proteins. The polymers were tailored to show an α-helix conformation that enabled increased hydrophobicity, prolonged membrane retention, and enhanced lipid radical trapping. The chiral polymers are amphiphilic, and the self-assembled micelles exhibited an extended blood circulation. At the lipopolysaccharide-induced macrophage and mice models, chiral polymer micelles effectively suppressed ferroptosis and repressed inflammatory cytokines. The current work provides an innovative means for attenuating uncontrolled inflammation by anti-ferroptotic polymer micelles.

Elimination of circulating tumor cells (CTCs) in the blood can be an effective therapeutic approach to disrupt metastasis. Here, a strategy is proposed to implement flexible wearable electronics and injectable nanomaterials to disrupt the hematogenous transport of CTCs. A flexible device containing an origami magnetic membrane is used to attract Fe3O4@Au nanoparticles (NPs) that are surface modified with specific aptamers and intravenously injected into blood vessels, forming an invisible hand and fishing line/bait configuration to specifically capture CTCs through bonding with aptamers. Thereafter, thinned flexible AlGaAs LEDs in the device offer an average fluence of 15.75 mW mm-2 at a skin penetration depth of 1.5 mm, causing a rapid rise of temperature to 48 degrees C in the NPs and triggering CTC death in 10 min. The flexible device has been demonstrated for intravascular isolation and enrichment of CTCs with a capture efficiency of 72.31% after 10 cycles in a simulated blood circulation system based on a prosthetic upper limb. The fusion of nanomaterials and flexible electronics reveals an emerging field that utilizes wearable and flexible stimulators to activate biological effects offered by nanomaterials, leading to improved therapeutical effects and postoperative outcomes of diseases.