Targeting RORγ inhibits the growth and metastasis of hepatocellular carcinoma.

Approximately 80%-90% of hepatocellular carcinomas (HCC) occur in a premalignant environment of fibrosis and abnormal extracellular matrix (ECM), highlighting an essential role of ECM in the tumorigenesis and progress of HCC. However, the determinants of ECM in HCC are poorly defined. Here, we show that nuclear receptor RORγ is highly expressed and amplified in HCC tumors. RORγ functions as an essential activator of the matrisome program via directly driving the expression of major ECM genes in HCC cells. Elevated RORγ increases fibronectin-1 deposition, cell-matrix adhesion, and collagen production, creating a favorable microenvironment to boost liver cancer metastasis. Moreover, RORγ antagonists effectively inhibit tumor growth and metastasis in multiple HCC xenografts and immune-intact models, and they effectively sensitize HCC tumors to sorafenib therapy in mice. Notably, elevated RORγ expression is associated with ECM remodeling and metastasis in patients with HCC. Taken together, we identify RORγ as a key player of ECM remodeling in HCC and as an attractive therapeutic target for advanced HCC.

CoQ10 enhances the efficacy of airway basal stem cell transplantation on bleomycin-induced idiopathic pulmonary fibrosis in mice.

BACKGROUND: Recent studies have demonstrated that airway basal stem cells (BCs) transplantation can ameliorate bleomycin-induced idiopathic pulmonary fibrosis (IPF) through lung regeneration promotion. However, BCs under oxidative stress in the alveolar microenvironment are poor in survival, causing unsatisfied efficacy of BCs transplantation. In this study, we investigated whether Coenzyme Q10(CoQ10) counteracts oxidative stress in the alveolar microenvironment, thus improved the efficacy of BCs transplantation for IPF treatment. METHODS: The protective effects of CoQ10 on H2O2-induced BCs apoptosis and cytoplasmic reactive oxygen species (ROS) level were tested by flow cytometry in vitro. The therapeutic effects of BCs combined with CoQ10 were compared to a single BCs transplantation protocol in IPF treatment after 2 weeks and were evaluated by parameters including changes of body weight and survival rate, as well as various levels of pulmonary inflammation, α-SMA expression and hydroxyproline (HYP) in IPF mouse lung tissues. RESULTS: CoQ10 preincubation with BCs (10 mM, 24 h) significantly reduced the late apoptosis of BCs and the number of oxidative stressful BCs as a result of H2O2 stimulation (1 mM, 6 h) in vitro. IPF mouse model was constructed through bleomycin (5 mg/kg) intratracheal instillation. Bleomycin-induced IPF mice showed weight loss continuously and mortality increased progressively during modeling. Serious pulmonary inflammatory cell infiltration, collagen fiber proliferation, and collagen protein deposition were observed in lung tissues of IPF mice. Though BCs transplantation alone improved indicators above in bleomycin-induced IPF mice to some extent, the combination with CoQ10 improved the transplantation efficacy and obtained better therapeutic effects. CONCLUSION: CoQ10 blocked H2O2-induced apoptosis of BCs and ROS production in vitro, and enhanced the efficacy of BCs transplantation against bleomycin-induced IPF in mice.

Antitumor effects of 3-bromoascochlorin on small cell lung cancer via inhibiting MAPK pathway.

Small cell lung cancer (SCLC) was defined as a recalcitrant cancer, and novel therapies are urgently needed. Marine natural products (MNPs) may bring continuing hope for treatment of SCLC. In this study, 3-bromoascochlorin (BAS), an MNP isolated from the coral-derived fungus Acremonium sclerotigenum GXIMD 02501, was primarily screened out with antiproliferative activity towards SCLC cell lines. Then western blot analysis (WB) and flow cytometry were conducted, and we found BAS could induce the apoptosis of H446 and H69AR cells. Besides, BAS could suppress the invasion and migration of H446. In an SCLC xenograft mice model, BAS inhibited the growth of tumor without affecting the body weight of mice. Finally, the underlying mechanisms were preliminarily explored. According to the results of RNA-seq, reverse transcription-quantitative polymerase chain reaction, and WB, our results revealed that BAS exerted antitumor activity via inhibiting mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinases (ERK) pathway. Collectively, these results indicated that BAS can be used as a promising compound for the treatment of human SCLC.

STAT1 participates in the induction of substance P expression in airway epithelial cells by respiratory syncytial virus.

PURPOSE: The regulation effect and mechanism of respiratory syncytial virus (RSV) infection on the expression of tachykinin substance P (SP) in airway epithelial cells was investigated. METHODS: The regulation of SP expression by RSV was investigated in the BEAS-2B airway epithelial cell line. RT-qPCR, immunofluorescence, and ELISA assay were used to examine the expression of the SP encoding gene TAC1, the intracellular SP protein expression, and the extracellular SP secretion. RESULTS: The mRNA expression of TAC1 and the intracellular SP protein level in BEAS-2B cells were significantly enhanced by RSV infection with multiplicity of infection (MOI) values of both 1 and 0.1 at 48 hours post infection. Heat-inactivated and UV-inactivated RSV, but not live RSV, significantly induced SP secretion in both control BEAS-2B cells and CX3CR1 receptor knockout cells without affecting the TAC1 gene expression or cell viability. RSV G protein (2-10 µg/ml) and fractalkine (10-50 ng/ml), both CX3CR1 receptor ligands, did not affect SP secretion in BEAS-2B cells. Inhibition of STAT1 phosphorylation by fludarabine (1 µM) markedly reduced the RSV-induced TAC1 gene expression and antagonized the inhibition of RSV replication by interferon-α in BEAS-2B cells. CONCLUSIONS: STAT1 participates in RSV infection-induced SP expression in airway epithelial cells.

Caveolin-1 Is Critical for Lymphocyte Trafficking into Central Nervous System during Experimental Autoimmune Encephalomyelitis.

UNLABELLED: Multiple sclerosis (MS) is a progressive autoimmune disease of the CNS with its underlying mechanisms not fully understood. In the present study, we tested the hypothesis that caveolin-1, a major membrane scaffolding protein, plays a critical role in the pathogenesis of experimental autoimmune encephalomyelitis, a laboratory murine model of MS. We found increased expression of caveolin-1 in serum and spinal cord tissues in association with disease incidence and severity in wild-type mice with active encephalomyelitis. After immunization, Cav-1 knock-out mice showed remarkable disease resistance with decreased incidence and clinical symptoms. Furthermore, Cav-1 knock-out mice had alleviated encephalitogenic T cells trafficking into the CNS with decreased expressions of adhesion molecules ICAM-1 and VCAM-1 within the lesions. In agreement with in vivo studies, in vitro knockdown of caveolin-1 compromised the upregulation of ICAM-1 in endothelial cells, leading to the amelioration of the transendothelial migration of pathogenic TH1 and TH17 cells. Together, those results indicate that caveolin-1 serves as an active modulator of CNS-directed lymphocyte trafficking and could be a therapeutic target for neuroinflammatory diseases, such as multiple sclerosis. SIGNIFICANCE STATEMENT: The hallmark feature of neuroinflammatory diseases is the massive infiltrations of encephalitogenic leukocytes into the CNS parenchyma, a process that remains largely unclear. Our study demonstrates the critical contribution of caveolin-1 to encephalomyelitis pathogenesis and CNS-directed lymphocyte trafficking by modulation of adhesion molecules ICAM-1 and VCAM-1, highlighting the pathological involvement of caveolin-1 in neuroinflammatory diseases.

Surface-enhanced resonance Raman scattering (SERRS) simulates PCR for sensitive DNA detection.

This paper describes a novel double-stranded DNA detection method through resonance between SYBR Green I and DNA with the surface-enhanced resonance Raman scattering (SERRS) assay, which opens an avenue to the quantitative and reliable application of SERRS in DNA detection.

Patient-derived organoids: a promising tool for breast cancer research.

Breast cancer (BC) is the most prevalent malignancy among women worldwide. Traditional research models such as primary cancer cell and patient-derived tumor xenografts (PDTXs) have limitations. Cancer cells lack a tumor microenvironment (TME) and genetic diversity, whereas PDTXs are expensive and have a time-consuming preparation protocol. Therefore, alternative research models are warranted. Patient-derived organoids (PDOs) are a promising in vitro model. They mimic the TME, gene expression, and cell types of original cancer tissues. PDOs have been successfully developed from various cancers, including BC. In this review, we focused on the value and limitations of PDOs in BC research, including their characteristics and potential in drug development, personalized therapy, immunotherapy, and the application prospects of PDOs in drug testing and prognosis.

Oligodendrocyte progenitor cell-specific delivery of lipid nanoparticles loaded with Olig2 synthetically modified messenger RNA for ischemic stroke therapy.

The transcription factor Olig2 is highly expressed throughout oligodendroglial development and is needed for the differentiation of oligodendrocyte progenitor cells (OPCs) into oligodendrocytes and remyelination. Although Olig2 overexpression in OPCs is a possible therapeutic target for enhancing myelin repair in ischemic stroke, achieving Olig2 overexpression in vivo remains a formidable technological challenge. To address this challenge, we employed lipid nanoparticle (LNP)-mediated delivery of Olig2 synthetically modified messenger RNA (mRNA) as a viable method for in vivo Olih2 protein overexpression. Specifically, we developed CD140a-targeted LNPs loaded with Olig2 mRNA (C-Olig2) to achieve targeted Olig2 protein expression within PDGFRα+ OPCs, with the goal of promoting remyelination for ischemic stroke therapy. We show that C-Olig2 promotes the differentiation of PDGFRα+ OPCs derived from mouse neural stem cells into mature oligodendrocytes in vitro, suggesting that mRNA-mediated Olig2 overexpression is a rational approach to promote oligodendrocyte differentiation and remyelination. Furthermore, when C-Olig2 was administered to a murine model of ischemic stroke, it led to improvements in blood‒brain barrier (BBB) integrity, enhanced remyelination, and rescued learning and cognitive deficits. Our comprehensive analysis, which included bulk RNA sequencing (RNA-seq) and single-nucleus RNA-seq (snRNA-seq), revealed upregulated biological processes related to learning and memory in the brains of mice treated with C-Olig2 compared to those receiving empty LNPs (Mock). Collectively, our findings highlight the therapeutic potential of multifunctional nanomedicine targeting mRNA expression for ischemic stroke and suggest that this approach holds promise for addressing various brain diseases. STATEMENT OF SIGNIFICANCE: While Olig2 overexpression in OPCs represents a promising therapeutic avenue for enhancing remyelination in ischemic stroke, in vivo strategies for achieving Olig2 expression pose considerable technological challenges. The delivery of mRNA via lipid nanoparticles is considered aa viable approach for in vivo protein expression. In this study, we engineered CD140a-targeted LNPs loaded with Olig2 mRNA (C-Olig2) with the aim of achieving specific Olig2 overexpression in mouse OPCs. Our findings demonstrate that C-Olig2 promotes the differentiation of OPCs into oligodendrocytes in vitro, providing evidence that mRNA-mediated Olig2 overexpression is a rational strategy to foster remyelination. Furthermore, the intravenous administration of C-Olig2 into a murine model of ischemic stroke not only improved blood-brain barrier integrity but also enhanced remyelination and mitigated learning and cognitive deficits. These results underscore the promising therapeutic potential of multifunctional nanomedicine targeting mRNA expression in the context of ischemic stroke.

Softening the tumor matrix through cholesterol depletion breaks the physical barrier for enhanced antitumor therapy.

The tumor develops defense tactics, including conversing the mechanical characteristics of tumor cells and their surrounding environment. A recent study reported that cholesterol depletion stiffens tumor cells, which could enhance adaptive T-cell immunotherapy. However, it remains unclear whether reducing the cholesterol in tumor cells contributes to re-educating the stiff tumor matrix, which serves as a physical barrier against drug penetration. Herein, we found that depleting cholesterol from tumor cells can demolish the intratumor physical barrier by disrupting the mechanical signal transduction between tumor cells and the extracellular matrix through the destruction of lipid rafts. This disruption allows nanoparticles (H/S@hNP) to penetrate deeply, resulting in improved photodynamic treatment. Our research also indicates that cholesterol depletion can inhibit the epithelial-mesenchymal transition and repolarize tumor-associated macrophages from M2 to M1, demonstrating the essential role of cholesterol in tumor progression. Overall, this study reveals that a cholesterol-depleted, softened tumor matrix reduces the difficulty of drug penetration, leading to enhanced antitumor therapeutics.

B(C6F5)3-Catalyzed Stereoselective 1,2-cis Arabinofuranosylation with a Conformationally Constrained Donor.

Compared with stereoselective glycosylation methods mainly addressed on the preparation of pyranose glycosides, the furanosylation has been more limited, especially for the 1,2-cis arabinofuranosylation. Herein, we report a novel stereoselective 1,2-cis-arabinofuranosylation strategy using a conformationally restricted 3,5-O-xylylene-protected arabinofuranosyl donor on activation with B(C6F5)3 for desired targets in moderate to excellent yields and ß-stereoselectivity. The effectiveness of the 1,2-cis-arabinofuranosylation strategy was demonstrated successfully with various acceptors, including carbohydrate alcohols.

Novel indocyanine green-loaded photothermal nanoparticles targeting TRPV1 for thermal ablation treatment of severe murine asthma induced by ovalbumin and lipopolysaccharide.

To identify a replacement strategy for bronchial thermoplasty (BT) with non-invasive and free-of-severe side effect is urgently needed in the clinic for severe asthma treatment. In this study, PLGA-PEG@ICG@TRPV1 pAb (PIT) photothermal nanoparticles targeting bronchial TRPV1 were designed for photothermal therapy (PTT) against severe murine asthma induced by ovalbumin and lipopolysaccharide. PIT was formulated with a polyethylene glycol (PEG)-grafted poly (lactic-co-glycolic) acid (PLGA) coating as a skeleton structure to encapsulate indocyanine green (ICG) and was conjugated to the polyclonal antibody against transient receptor potential vanilloid 1 (TRPV1 pAb). The results revealed that PIT held good druggability due to its electronegativity and small diameter. PIT demonstrated great photothermal effects both in vivo and in vitro and exhibited good ability to target TRPV1 in vitro because of its selective cell uptake and specific cell toxicity toward TRPV1-overexpressing cells. The PIT treatment effectively reduced asthma symptoms in mice. This is evident from improvements in expiratory airflow limitation, significant decreases in inflammatory cell infiltration in the airways, and increases in goblet cell and columnar epithelial cell proliferation. In conclusion, PIT alleviates severe murine asthma symptoms through a combination of TRPV1 targeting and photothermal effects.

Dual-Targeting Nanovesicles Carrying CSF1/CD47 Identified from Single-Cell Transcriptomics of Innate Immune Cells in Heart Transplant for Alleviating Acute Rejection.

Although immunosuppressive drugs for targeting T cells are the standard of care in acute transplantation rejection, the role of innate immune cells should not be ignored. Here, single-cell RNA sequencing (scRNA-seq) and flow cytometry are performed to reveal the dynamic changes of innate immune cells within the acute rejection time and find a significantly-increased presence of Ly6G- Ly6C+ inflammatory macrophages and decreased presence of neutrophils among all types of immune cells. Next, to further explore potential targets regulating Ly6G- Ly6C+ inflammatory macrophages, scRNA-seq is used to analyze the reciprocal signaling of both neutrophils and macrophages, along with the surface genes of macrophages. It is found that activating colony-stimulating factor 1/ colony-stimulating factor 1 receptor (CSF1/CSF1R) andcluster of differentiation 47/signal regulatory protein α (CD47/SIRPα) signaling may serve as a strategy to relieve Ly6G- Ly6C+ inflammatory macrophage-mediated early graft rejection. To investigate this hypothesis, CSF1/CD47 dual-targeting nanovesicles (NVs) derived from IFN-γ-stimulated induced pluripotent stem cell-derived mesenchymal stem cells ( iPSC-MSCs )are designed and constructed. It is confirmed that CSF1/CD47 NVs synergistically induce the differentiation of Ly6G- Ly6C- M2 inhibitory macrophages by the CSF1/CSF1R pathway, and inhibit the phagocytosis of inflammatory macrophages and inflammatory response by the CD47/SIRPα pathway, ultimately relieving immune rejection. This study highlights the power of dual-targeting CSF1/CD47 NVs as an immunosuppressant against early innate immune responses with the potential for broad clinical applications.

A nanocomposite hydrogel for co-delivery of multiple anti-biofilm therapeutics to enhance the treatment of bacterial biofilm-related infections.

The characteristics of biofilms have exacerbated the issue of clinical antibiotic resistance, rendering it a pressing challenge in need of resolution. The combination of biofilm-dispersing agents and antibiotics can eliminate biofilms and promote healing synergistically in infected wounds. In this study, we developed a novel nanocomposite hydrogel (NC gel) comprised of the poly(lactic acid)-hyperbranched polyglycerol (PLA-HPG) based bioadhesive nanoparticles (BNPs) and a hydrophilic carboxymethyl chitosan (CS) network. The NC gel was designed to co-deliver two biofilm-dispersing agents (an NO-donor SNO, and an α-amylase Am) and an antibiotic, cefepime (Cef), utilizing a synergistic anti-biofilm mechanism in which Am loosens the matrix structure and NO promotes the release of biofilm bacteria via quorum sensing, and Cef kills bacteria. The drug-loaded NC gel (SNO/BNP/CS@Am-Cef) demonstrated sustained drug release, minimal cytotoxicity, and increased drug-bacterial interactions at the site of infection. When applied to mice infected with methicillin-resistant Staphylococcus aureus (MRSA) biofilms in vivo, SNO/BNP/CS@Am-Cef enhanced biofilm elimination and promoted wound healing compared to traditional antibiotic treatments. Our work demonstrates the feasibility of the co-delivery of biofilm-dispersing agents and antibiotics using the NC gel and presents a promising approach for the polytherapy of bacterial biofilm-related infections.

Effects of four antitussives on airway neurogenic inflammation in a guinea pig model of chronic cough induced by cigarette smoke exposure.

OBJECTIVE: The effects of four antitussives, including codeine phosphate (CP), moguisteine, levodropropizine (LVDP) and naringin, on airway neurogenic inflammation and enhanced cough were investigated in guinea pig model of chronic cough. METHODS: Guinea pigs were exposed to CS for 8 weeks. At the 7th and 8th week, the animals were treated with vehicle, CP (4.8 mg/kg), moguisteine (24 mg/kg), LVDP (14 mg/kg) and naringin (18.4 mg/kg) respectively. Then the cough and the time-enhanced pause area under the curve (Penh-AUC) during capsaicin challenge were recorded. The substance P (SP) content, NK-1 receptor expression and neutral endopeptidase (NEP) activity in lung were determined. RESULTS: Chronic CS exposure induced a bi-phase time course of cough responsiveness to capsaicin. Eight weeks of CS exposure significantly enhanced the airway neurogenic inflammation and cough response in guinea pigs. Two weeks of treatment with CP, moguisteine, LVDP or naringin effectively attenuated the chronic CS-exposure enhanced cough. Only naringin exerted significant effect on inhibiting Penh-AUC, SP content and NK-1 receptor expression, as well as preventing the declining of NEP activity in lung. CONCLUSIONS: Chronic CS-exposed guinea pig is suitable for studying chronic pathological cough, in which naringin is effective on inhibiting both airway neurogenic inflammation and enhanced cough.

Two-dimensional porous vermiculite-based nanocatalysts for synergetic catalytic therapy.

This study reports an ultrasound-mediated and two-dimensional (2D) porous vermiculite nanosheets (VMT NSs)-based nanocatalyst platform (Arg@VMT@PDA-PEG) that synergistically harnessed the Fenton reaction-based chemodynamic therapy (CDT), 2D semiconductor-based sonodynamic therapy (SDT) and nitric oxide (NO)-based gas therapy for combination cancer therapy. The tumor microenvironment responsive degradation of polydopamine (PDA) shell could not only prevent L-Arg, a NO donor, leakage during blood circulation, but also selectively release the active sites of VMT NSs for catalytic reactions in tumor cells. Additionally, the Fenton reactions mediated by the abundant Fe2+/Fe3+ in VMT NSs could efficiently produce ·OH and consume glutathione (GSH) for CDT. Moreover, the reactive oxygen species (ROS, ·OH and ·O2-) produced by ultrasound-triggered Arg@VMT@PDA-PEG could not only execute SDT but also oxidize L-Arg to NO for synergetic gas therapy. The results show that the transformation of ROS to NO can enhance curative efficacy owing to the ability of NO with much longer life-time in freely diffusing into cells from intercellular space. This biodegradable Arg@VMT@PDA-PEG nanocatalytic platform integrating three different catalytic reactions provides a new therapeutic paradigm for combination cancer therapy.

Human-Hair-Derived Natural Particles as Multifunctional Sunscreen for Effective UV Protection.

Excessive ultraviolet (UV) radiation can lead to a series of skin problems. Although commercial sunscreens can protect skin from UV-induced damage to an extent, the side effects caused by such products are still worrisome. Here, inspired by the natural photoprotection effect of human hair, we extracted the multifunctional particles from human hair as sunscreens for UV protection. Both in vitro and in vivo results indicate that hair-derived particles (HDPs) could effectively protect skin from UV radiation. Besides, HDPs retain the antioxidant capability of melanin in hair, which avoids UV-induced oxidative damage. In addition, the unique shape of HDPs can prevent them from penetrating into the skin, thus avoiding potential toxicity. Moreover, owing to their mesoporous structure, the particles can also be used as drug carriers. With the loading of octocrylene, the particles are more effective in blocking UV radiation. This study provides an ingenious tactic for the design and development of sunscreens from a natural substance.

Effective Treatment of Haemophilus influenzae-Induced Bacterial Conjunctivitis by a Bioadhesive Nanoparticle Reticulate Structure.

Ocular formulations should provide an effective antibiotic concentration at the site of infection to treat bacterial eye infections. However, tears and frequent blinking accelerate the drug clearance rate and limit drug residence time on the ocular surface. This study describes a biological adhesion reticulate structure (BNP/CA-PEG) consisting of antibiotic-loaded bioadhesion nanoparticles (BNP/CA), with an average 500-600 nm diameter, and eight-arm NH2-PEG-NH2 for local and extended ocular drug delivery. This retention-prolonging effect is a function of the Schiff base reaction between groups on the surface of BNP and amidogen on PEG. BNP/CA-PEG showed significantly higher adhesion properties and better treatment efficacy in an ocular rat model with conjunctivitis in comparison to non-adhesive nanoparticles, BNP, or free antibiotics. Both in vivo safety experiment and in vitro cytotoxicity test verified the biocompatibility and biosafety of the biological adhesion reticulate structure, indicating a promising translational prospect for further clinical use.

Verteporfin-Loaded Bioadhesive Nanoparticles for the Prevention of Hypertrophic Scar.

Hypertrophic scarring (HS) is a common skin injury complication with unmet needs. Verteporfin (VP) should be an ideal HS-targeted therapeutic drug due to its efficient fibrosis and angiogenesis inhibitory abilities. However, its application is restricted by its side effects such as dose-dependent cytotoxicity on normal cells. Herein, the bioadhesive nanoparticles encapsulated VP (VP/BNPs) are successfully developed to attenuate the side effects of VP and enhance its HS inhibition effects by limiting VP releasing slowly and stably in the lesion site but not diffusing easily to normal tissues. VP/BNPs displayed significant inhibition on the proliferation, migration, collagen deposition, and vessel formation of human hypertrophic scar fibroblasts (HSFBs) and dermal vascular endothelial cells (HDVECs). In a rat tail HS model, VP/BNPs treated HS exhibits dramatic scar repression with almost no side effects compared with free VP or VP-loaded non-bioadhesive nanoparticles (VP/NNPs) administration. Further immunofluorescence analysis on scar tissue serial sections validated VP/BNPs effectively inhibited the collagen deposition and angiogenesis by firmly confined in the scar tissue and persistently releasing VP targeted to nucleus Yes-associated protein (nYAP) of HSFBs and HDVECs. These findings collectively suggest that VP/BNPs can be a promising and technically advantageous agent for HS therapies.

Structure-Based Design and Characterization of the Highly Potent and Selective Covalent Inhibitors Targeting the Lysine Methyltransferases G9a/GLP.

Protein lysine methyltransferases G9a and GLP, which catalyze mono- and di-methylation of histone H3K9 and nonhistone proteins, play important roles in diverse cellular processes. Overexpression or dysregulation of G9a and GLP has been identified in various types of cancer. Here, we report the discovery of a highly potent and selective covalent inhibitor 27 of G9a/GLP via the structure-based drug design approach following structure-activity relationship exploration and cellular potency optimization. Mass spectrometry assays and washout experiments confirmed its covalent inhibition mechanism. Compound 27 displayed improved potency in inhibiting the proliferation and colony formation of PANC-1 and MDA-MB-231 cell lines and exhibited enhanced potency in reducing the levels of H3K9me2 in cells compared to noncovalent inhibitor 26. In vivo, 27 showed significant antitumor efficacy in the PANC-1 xenograft model with good safety. These results clearly indicate that 27 is a highly potent and selective covalent inhibitor of G9a/GLP.

Citrus peel extract protects against diesel exhaust particle-induced chronic obstructive pulmonary disease-like lung lesions and oxidative stress.

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide and characterized by emphysema, small airway remodeling and mucus hypersecretion. Citrus peels have been widely used as food spices and in traditional Chinese medicine for chronic lung disease. Given that citrus peels are known for containing antioxidants and anti-inflammatory compounds, we hypothesize that citrus peel intake can suppress oxidative stress and inflammatory response to air pollution exposure, thereby alleviating COPD-like pathologies. This study aimed to investigate the efficacy of citrus peel extract, namely Guang Chenpi (GC), in preventing the development of COPD induced by diesel exhaust particles (DEPs) and its potential mechanism. DEP-induced COPD-like lung pathologies, inflammatory responses and oxidative stress with or without GC treatment were examined in vivo and in vitro. Our in vivo study showed that GC was effective in decreasing inflammatory cell counts and inflammatory mediator (IL-17A and TNF-α) concentrations in bronchoalveolar lavage fluid (BALF). Pretreatment with GC extract also significantly decreased oxidative stress in the serum and lung tissue of DEP-induced COPD rats. Furthermore, GC pretreatment effectively reduced goblet cell hyperplasia (PAS positive cells) and fibrosis of the small airways, decreased macrophage infiltration as well as carbon loading in the peripheral lungs, and facilitated the resolution of emphysema and small airway remodeling in DEP-induced COPD rats. An in vitro free radical scavenging assay revealed robust antioxidant potential of GC in scavenging DPPH free radicals. Moreover, GC demonstrated potent capacities in reducing ROS production and enhancing SOD activity in BEAS-2B cells stimulated by DEPs. GC treatment significantly attenuated the increased level of IL-8 and MUC5AC from DEP-treated BEAS-2B cells. Mechanistically, GC treatment upregulated the protein level of Nrf-2 and could function via MAPK/NF-κB signaling pathways by suppressing the phosphorylation of p38, JNK and p65. Citrus peel extract is effective in decreasing oxidative stress and inflammatory responses of the peripheral lungs to DEP exposure. These protective effects further contributed to the resolution of COPD-like pathologies.