Release Of Damage-associated Molecular Patterns Research Articles

Self-Adaptive Photodynamic-to-Photothermal Switch for Smart Antitumor Photoimmunotherapy.

Photodynamic therapy (PDT) and photothermal therapy (PTT) possess different merits in cancer phototherapy, but the tumor microenvironment becomes unfavorable during the phototheranostic progress. Herein, we report a self-adaptive cyanine derivative Cy5-TPA with the PDT-dominated state to PTT-dominated state autoswitch feature for enhanced photoimmunotherapy. The incorporation of rotatable triphenylamine (TPA) moiety renders Cy5-TPA with the temperature or intramolecular-motion regulated photoactivities, which shows preferable reactive oxygen species (ROS) generation at lower temperature while stronger photothermal conversion at higher ones. Such a promising feature permits the in situ switch from PDT-dominated state to PTT-dominated state along with intratumoral temperature increase during laser irradiation, which also works in line with the concurrently reduced intratumoral oxygen level, exhibiting a self-adaptive phototherapeutic behavior to maximize the phototherapeutic antitumor outcome. Most importantly, the self-adaptive PDT-dominated state to PTT-dominated state switch also facilitates the sequential generation and release of damage-associated molecular patterns during immunogenic cell death (ICD). Hence, Cy5-TPA demonstrates excellent photoimmunotherapy performance in ICD induction, dendritic cell maturation, and T cell activation for tumor eradication and metastasis inhibition.

Self-enhanced regulation of stable organic radicals with polypeptide nanoparticles for mild second near-infrared phototheranostics

Stable organic radicals have emerged as a promising option to enhance fluorescence quantum yield (QY), gaining traction in medical treatment due to their unique electronic transitions from the ground state (D0) to the doublet excited state (D1). We synthesized a stable dicyanomethyl radical with a NIR-II fluorescence QY of 0.86 %, surpassing many NIR-II organic dyes. Subsequently, amphiphilic polymer-encapsulated nanoparticles (NPs) containing the radical were created, achieving a NIR-II fluorescence QY of 0.32 %, facilitating high-contrast bio-imaging. These CNPPs exhibit self-enhanced photothermal properties, elevating photothermal conversion efficiency (PCE) from 43.5 % to 57.5 % under 915 nm laser irradiation. This advancement enables more efficient photothermal therapy (PTT) with lower dye concentrations and reduced laser power, enhancing both feasibility and safety. Through regular fractionated mild photothermal therapy, we observed the release of damage-associated molecular patterns (DAMPs) and an increase in cytokine expression, culminating in combined mild phototherapy (m-PTT)-mediated immunogenic cell death (ICD). Consequently, we developed an immunostimulatory tumor vaccine, showcasing a novel approach for refining photothermal agents (PTA) and optimizing the PTT process.

Antileukemic potential of methylated indolequinone MAC681 through immunogenic necroptosis and PARP1 degradation

BackgroundDespite advancements in chronic myeloid leukemia (CML) therapy with tyrosine kinase inhibitors (TKIs), resistance and intolerance remain significant challenges. Leukemia stem cells (LSCs) and TKI-resistant cells rely on altered mitochondrial metabolism and oxidative phosphorylation. Targeting rewired energy metabolism and inducing non-apoptotic cell death, along with the release of damage-associated molecular patterns (DAMPs), can enhance therapeutic strategies and immunogenic therapies against CML and prevent the emergence of TKI-resistant cells and LSC persistence.MethodsTranscriptomic analysis was conducted using datasets of CML patients' stem cells and healthy cells. DNA damage was evaluated by fluorescent microscopy and flow cytometry. Cell death was assessed by trypan blue exclusion test, fluorescent microscopy, flow cytometry, colony formation assay, and in vivo Zebrafish xenografts. Energy metabolism was determined by measuring NAD+ and NADH levels, ATP production rate by Seahorse analyzer, and intracellular ATP content. Mitochondrial fitness was estimated by measurements of mitochondrial membrane potential, ROS, and calcium accumulation by flow cytometry, and morphology was visualized by TEM. Bioinformatic analysis, real-time qPCR, western blotting, chemical reaction prediction, and molecular docking were utilized to identify the drug target. The immunogenic potential was assessed by high mobility group box (HMGB)1 ELISA assay, luciferase-based extracellular ATP assay, ectopic calreticulin expression by flow cytometry, and validated by phagocytosis assay, and in vivo vaccination assay using syngeneic C57BL/6 mice.ResultsTranscriptomic analysis identified metabolic alterations and DNA repair deficiency signatures in CML patients. CML patients exhibited enrichment in immune system, DNA repair, and metabolic pathways. The gene signature associated with BRCA mutated tumors was enriched in CML datasets, suggesting a deficiency in double-strand break repair pathways. Additionally, poly(ADP-ribose) polymerase (PARP)1 was significantly upregulated in CML patients’ stem cells compared to healthy counterparts. Consistent with the CML patient DNA repair signature, treatment with the methylated indolequinone MAC681 induced DNA damage, mitochondrial dysfunction, calcium homeostasis disruption, metabolic catastrophe, and necroptotic-like cell death. In parallel, MAC681 led to PARP1 degradation that was prevented by 3-aminobenzamide. MAC681-treated myeloid leukemia cells released DAMPs and demonstrated the potential to generate an immunogenic vaccine in C57BL/6 mice. MAC681 and asciminib exhibited synergistic effects in killing both imatinib-sensitive and -resistant CML, opening new therapeutic opportunities.ConclusionsOverall, increasing the tumor mutational burden by PARP1 degradation and mitochondrial deregulation makes CML suitable for immunotherapy.

DAMP sensing and sterile inflammation: intracellular, intercellular and inter-organ pathways.

Damage-associated molecular patterns (DAMPs) are endogenous molecules that are released from host cells as a result of cell death or damage. The release of DAMPs in tissues is associated with loss of tissue homeostasis. Sensing of DAMPs by innate immune receptors triggers inflammation, which can be beneficial in initiating the processes that restore tissue homeostasis but can also drive inflammatory diseases. In recent years, the sensing of intracellular DAMPs has received extensive attention in the field of sterile inflammation. However, emerging studies have shown that DAMPs that originate from neighbouring cells, and even from distal tissues or organs, also mediate sterile inflammatory responses. This multi-level sensing of DAMPs is crucial for intercellular, trans-tissue and trans-organ communication. Here, we summarize how DAMP-sensing receptors detect DAMPs from intracellular, intercellular or distal tissue and organ sources to mediate sterile inflammation. We also discuss the possibility of targeting DAMPs or their corresponding receptors to treat inflammatory diseases.

Mitochondria-Derived Vesicles, Sterile Inflammation, and Pyroptosis in Liver Cancer: Partners in Crime or Innocent Bystanders?

Alterations in cellular signaling, chronic inflammation, and tissue remodeling contribute to hepatocellular carcinoma (HCC) development. The release of damage-associated molecular patterns (DAMPs) upon tissue injury and the ensuing sterile inflammation have also been attributed a role in HCC pathogenesis. Cargoes of extracellular vesicles (EVs) and/or EVs themselves have been listed among circulating DAMPs but only partially investigated in HCC. Mitochondria-derived vesicles (MDVs), a subpopulation of EVs, are another missing link in the comprehension of the molecular mechanisms underlying the onset and progression of HCC biology. EVs have been involved in HCC growth, dissemination, angiogenesis, and immunosurveillance escape. The contribution of MDVs to these processes is presently unclear. Pyroptosis triggers systemic inflammation through caspase-dependent apoptotic cell death and is implicated in tumor immunity. The analysis of this process, together with MDV characterization, may help capture the relationship among HCC development, mitochondrial quality control, and inflammation. The combination of immune checkpoint inhibitors (i.e., atezolizumab and bevacizumab) has been approved as a synergistic first-line systemic treatment for unresectable or advanced HCC. The lack of biomarkers that may allow prediction of treatment response and, therefore, patient selection, is a major unmet need. Herein, we overview the molecular mechanisms linking mitochondrial dysfunction, inflammation, and pyroptosis, and discuss how immunotherapy targets, at least partly, these routes.

Myocardial reperfusion injury exacerbation due to ALDH2 deficiency is mediated by neutrophil extracellular traps and prevented by leukotriene C4 inhibition.

The Glu504Lys polymorphism in the aldehyde dehydrogenase 2 (ALDH2) gene is closely associated with myocardial ischaemia/reperfusion injury (I/RI). The effects of ALDH2 on neutrophil extracellular trap (NET) formation (i.e. NETosis) during I/RI remain unknown. This study aimed to investigate the role of ALDH2 in NETosis in the pathogenesis of myocardial I/RI. The mouse model of myocardial I/RI was constructed on wild-type, ALDH2 knockout, peptidylarginine deiminase 4 (Pad4) knockout, and ALDH2/PAD4 double knockout mice. Overall, 308 ST-elevation myocardial infarction patients after primary percutaneous coronary intervention were enrolled in the study. Enhanced NETosis was observed in human neutrophils carrying the ALDH2 genetic mutation and ischaemic myocardium of ALDH2 knockout mice compared with controls. PAD4 knockout or treatment with NETosis-targeting drugs (GSK484, DNase1) substantially attenuated the extent of myocardial damage, particularly in ALDH2 knockout. Mechanistically, ALDH2 deficiency increased damage-associated molecular pattern release and susceptibility to NET-induced damage during myocardial I/RI. ALDH2 deficiency induced NOX2-dependent NETosis via upregulating the endoplasmic reticulum stress/microsomal glutathione S-transferase 2/leukotriene C4 (LTC4) pathway. The Food and Drug Administration-approved LTC4 receptor antagonist pranlukast ameliorated I/RI by inhibiting NETosis in both wild-type and ALDH2 knockout mice. Serum myeloperoxidase-DNA complex and LTC4 levels exhibited the predictive effect on adverse left ventricular remodelling at 6 months after primary percutaneous coronary intervention in ST-elevation myocardial infarction patients. ALDH2 deficiency exacerbates myocardial I/RI by promoting NETosis via the endoplasmic reticulum stress/microsomal glutathione S-transferase 2/LTC4/NOX2 pathway. This study hints at the role of NETosis in the pathogenesis of myocardial I/RI, and pranlukast might be a potential therapeutic option for attenuating I/RI, particularly in individuals with the ALDH2 mutation.

The Ability of Clinically Relevant Chemotherapeutics to Induce Immunogenic Cell Death in Squamous Cell Carcinoma.

Immunogenic cell death (ICD) is a crucial mechanism for triggering the adaptive immune response in cancer patients. Damage-associated molecular patterns (DAMPs) are critical factors in the detection of ICD. Chemotherapeutic drugs can cause ICD and the release of DAMPs. The aim of this study was to assess the potential for paclitaxel and platinum-based chemotherapy regimens to induce ICD in squamous cell carcinoma (SCC) cell lines. In addition, we examined the immunostimulatory effects of clinically relevant chemotherapeutic regimens utilized in the treatment of SCC. We screened for differentially expressed ICD markers in the supernatants of three SCC cell lines following treatment with various chemotherapeutic agents. The ICD markers included Adenosine Triphosphate (ATP), Calreticulin (CRT), Annexin A1 (ANXA 1), High Mobility Group Protein B1 (HMGB1), and Heat Shock Protein 70 (HSP70). A vaccination assay was also employed in C57BL/6J mice to validate our in vitro findings. Lastly, the levels of CRT and HMGB1 were evaluated in Serum samples from SCC patients. Addition of the chemotherapy drugs cisplatin (DDP), carboplatin (CBP), nedaplatin (NDP), oxaliplatin (OXA) and docetaxel (DOC) increased the release of ICD markers in two of the SCC cell lines. Furthermore, mice that received vaccinations with cervical cancer cells treated with DDP, CBP, NDP, OXA, or DOC remained tumor-free. Although CBP induced the release of ICD-associated molecules in vitro, it did not prevent tumor growth at the vaccination site in 40% of mice. In addition, both in vitro and in vivo results showed that paclitaxel (TAX) and LBP did not induce ICD in SCC cells. The present findings suggest that chemotherapeutic agents can induce an adjuvant effect leading to the extracellular release of DAMPs. Of the agents tested here, DDP, CBP, NDP, OXA and DOC had the ability to act as inducers of ICD.

FePd Nanozyme- and SKN-Encapsulated Functional Lipid Nanoparticles for Cancer Nanotherapy via ROS-Boosting Necroptosis.

Cell necroptosis has presented great potential, acting as an effective approach against tumor apoptotic resistance, and it could be further enhanced via accompanying reactive oxygen species (ROS) overexpression. However, whether overproduced ROS assists the necroptotic pathway remains unclear. Thus, iron-palladium nanozyme (FePd NZ)- and shikonin (SKN)-encapsulated functional lipid nanoparticles (FPS-LNPs) were designed to investigate the ROS overexpression-enhanced SKN-induced necroptosis. In this system, SKN acts as an effective necroptosis inducer for cancer cells, and FePd NZ, a sensitive Fenton reaction catalyst, produces extra-intracellular ROS to reinforce the necroptotic pathway. Both in vitro and in vivo antitumor evaluation revealed that FPS-LNPs presented the best tumor growth inhibition efficacy compared with FP-LNPs or SKN-LNPs alone. Meanwhile, induced necroptosis by FPS-LNPs can further trigger the release of damage-associated molecular patterns (DAMPs) and antigens from dying tumor cells to activate the innate immune response. Taking biosafety into consideration, this study has provided a potential nanoplatform for cancer nanotherapy via inducing necroptosis to avoid apoptosis resistance and activate CD8+ T cell immune response.

Thrombospondin-1 Regulates Trophoblast Necroptosis via NEDD4-Mediated Ubiquitination of TAK1 in Preeclampsia.

Preeclampsia (PE) is considered as a disease of placental origin. However, the specific mechanism of placental abnormalities remains elusive. This study identified thrombospondin-1 (THBS1) is downregulated in preeclamptic placentae and negatively correlated with blood pressure. Functional studies show that THBS1 knockdown inhibits proliferation, migration, and invasion and increases the cycle arrest and apoptosis rate of HTR8/SVneo cells. Importantly, THBS1 silencing induces necroptosis in HTR8/SVneo cells, accompanied by the release of damage-associated molecular patterns (DAMPs). Necroptosis inhibitors necrostatin-1 and GSK'872 restore the trophoblast survival while pan-caspase inhibitor Z-VAD-FMK has no effect. Mechanistically, the results show that THBS1 interacts with transforming growth factor B-activated kinase 1 (TAK1), which is a central modulator of necroptosis quiescence and affects its stability. Moreover, THBS1 silencing up-regulates the expression of neuronal precursor cell-expressed developmentally down-regulated 4 (NEDD4), which acts as an E3 ligase of TAK1 and catalyzes K48-linked ubiquitination of TAK1 in HTR8/SVneo cells. Besides, THBS1 attenuates PE phenotypes and improves the placental necroptosis in vivo. Taken together, the down-regulation of THBS1 destabilizes TAK1 by activating NEDD4-mediated, K48-linked TAK1 ubiquitination and promotes necroptosis and DAMPs release in trophoblast cells, thus participating in the pathogenesis of PE.

Spatiotemporally-controlled supramolecular hybrid nanoassembly enabling ferroptosis-augmented photodynamic immunotherapy of cancer

Photodynamic therapy (PDT) not only directly eradicates tumor cells but also boosts immunogenicity, promoting antigen presentation and immune cell infiltration. However, the robust antioxidant defense mechanisms within tumor cells significantly weaken the efficacy of photodynamic immunotherapy. Herein, a supramolecular hybrid nanoassembly is constructed by exploring the synergistic effects of the photodynamic photosensitizer (pyropheophorbide a, PPa) and the ferroptosis inducer (erastin). The erastin-mediated inhibition of system Xc− significantly downregulates glutathione (GSH) expression, amplifying intracellular oxidative stress, leading to pronounced cell apoptosis, and promoting the release of damage-associated molecular patterns (DAMPs). Additionally, the precise cooperation of PPa and erastin enhances ferroptosis efficiency, exacerbating the accumulation of lipid peroxides (LPOs). Ultimately, LPOs serve as a “find me” signal, while DMAPs act as an “eat me” signal, collectively promoting dendritic cell maturation, enhancing infiltration of the cytotoxic T lymphocytes, and eliciting a robust immune response. This study opens new horizons for enhancing tumor immunotherapy through simultaneous ferroptosis-PDT.

Mechanisms of triggering antitumor immunity: from photodynamic effects to immunogenic cell death

The development of cancer immunotherapies provides hope to millions of patients for better clinical outcomes after tumor treatment. Thus, investigating the fundamental mechanisms of antitumor immunity activation is an urgent task. Numerous studies have outlined the effect of immunogenic cell death (ICD) on cancer cells, and this outcome is both sophisticated and simple. Different stimuli can cause ICD; however, photodynamic exposure has been proven to be an effective inducer of programed death on par with radiotherapy. The link between triggering a photodynamic response in cancer cells and triggering ICD has been poorly described in experimental works. The question of which molecular cascades are activated after photodynamic therapy (PDT) irradiation and the way damage-associated molecular patterns (DAMPs) are released is intriguing. Much is known about reactive oxygen species generation and endoplasmic reticulum stress but little about the Golgi apparatus. Photosensitizers of different types can exert different effects, including completely nonimmunogenic ones.
 This review describes the cascades that link the induction of cell death by photodynamic exposure and the immunogenic pattern of DAMP release. The photosensitizers that have shown potential as ICD inducers and the different pathways of programed death that occur during PDT exposure are also discussed.

Neoadjuvant chemo-immunotherapy is improved with a novel pulsed electric field technology in an immune-cold murine model.

Chemo-immunotherapy uses combined systemic therapies for resectable and unresectable tumors. This approach is gaining clinical momentum, but survival increases leave considerable room for improvement. A novel form of Pulsed Electric Field (PEF) ablation combines focal tissue destruction with immune activation in preclinical settings. The PEFs induce lethal cell damage without requiring thermal processes, leaving cellular proteins intact. This affords PEF a favorable safety profile, improved antigenicity, and significant immunostimulatory damage-associated molecular pattern release compared to other focal therapies. Preclinical investigations demonstrate a combinatorial benefit of PEF with immunostimulation. This study evaluates whether this proprietary PEF therapy induces an immunostimulatory effect sufficient to augment systemic neoadjuvant chemotherapy and immunotherapy to reverse metastatic disease in an immune-cold murine tumor model. To determine whether PEF improves a neoadjuvant chemo-immunotherapy standard-of-care, partial PEF ablation was delivered to orthotopically inoculated 4T1 metastatic tumors in addition to combinations of cisplatin chemotherapy and/or αPD-1 immunotherapy, followed by resection. In addition, to determine whether PEF combined with chemo-immunotherapy improves local and metastatic response in unresectable populations, partial PEF ablation was added to chemo-immunotherapy in mice that did not receive resection. Blood cytokines and flow cytometry evaluated immune response. Partial PEF ablation generates an immunostimulatory tumor microenvironment, increases systemic immune cell populations, slows tumor growth, and prolongs survival relative to neoadjuvant systemic therapies-alone. These data suggest the addition of this proprietary PEF locoregional therapy may synergize with systemic standard-of-care paradigms to improve outcomes with potential or demonstrated metastatic disease in both resectable and unresectable patient cohorts.

Abstract 5995: How FDA-approved drug, Aprepitant, induces immunogenic death of cancer cells

Abstract Aprepitant is a long-standing FDA approved anti-nausea drug, recently re-purposed as an early-stage anticancer agent; how aprepitant kills cancer cells was not well studied. We find that aprepitant kills human and mouse cancer cells by hyperactivating the stress response pathway, the anticipatory unfolded protein response (a-UPR), thereby inducing immune cell activating necrotic cell death. Aprepitant is a small molecule neurokinin-1 receptor (NK-1R) antagonist widely used to prevent nausea and vomiting in cancer patients undergoing chemotherapy. Recently aprepitant has shown promise in mouse xenograft studies of colon, lung and pancreatic cancer and melanoma. Since aprepitant was thought to trigger release of calcium stored in the lumen of the endoplasmic reticulum, the step that we showed triggers hyperactivation of the a-UPR by ErSO family anticancer agents, we explored the role of the a-UPR in aprepitant action. Aprepitatnt robustly activates the PERK arm of the UPR increasing p-PERK and peIF2α, inhibiting protein synthesis. Notably, aprepitant treatment results in ATP depletion and activation of AMPK. Aprepitant induced rapid cell death was not blocked by apoptosis inhibitors or necroptosis inhibitors. In both standard 2-dimensional cell culture and 3-dimensional organoid culture aprepitant-treated breast cancer cells displayed typical features of necrotic cell death, including cell swelling, membrane rupture, and cytoplasmic vacuolization. Cell death by necrosis and membrane rupture leads to release of immune cell activating cell contents termed damage-associated molecular patterns (DAMPs). Aprepitant treatment induces release of the classic DAMPs, HMGB1 and ATP and medium from aprepitant-treated breast cancer cells enhances migration of differentiated human THP-1 macrophage. Thus aprepitant and other necrosis inducing therapies elicit immunogenic cell death (ICD) and may have the potential to enhance adjuvant immunotherapy. Genome-wide CRISPR screens with negative selection against aprepitant and other studies are being used to explore the pathways of aprepitant induced cell death and evaluate its therapeutic efficacy. Since FDA-approved aprepitant has been widely used for many years, identifying its pathway of action will both accelerate its clinical transition as an anticancer agent and help identify patients whose genetic profiles make them most likely to benefit from aprepitant therapy. Citation Format: Xinyi Dai, Junyao Zhu, Sofia Perry, Qianjin Jiang, David J. Shapiro. How FDA-approved drug, Aprepitant, induces immunogenic death of cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5995.

The role of surgical tissue injury and intraoperative sympathetic activation in postoperative immunosuppression after breast-conserving surgery versus mastectomy: a prospective observational study

BackgroundBreast cancer is the second most common cause of death from cancer in women worldwide. Counterintuitively, large population-based retrospective trials report better survival after breast-conserving surgery (BCS) compared to mastectomy, corrected for tumour- and patient variables. More extensive surgical tissue injury and activation of the sympathetic nervous system by nociceptive stimuli are associated with immune suppression. We hypothesized that mastectomy causes a higher expression of plasma damage associated molecular patterns (DAMPs) and more intraoperative sympathetic activation which induce postoperative immune dysregulation. Immune suppression can lead to postoperative complications and affect tumour-free survival.MethodsIn this prospective observational study, plasma DAMPs (HMGB1, HSP70, S100A8/A9 and S100A12), intraoperative sympathetic activation (Nociception Level (NOL) index from 0 to 100), and postoperative immune function (plasma cytokine concentrations and ex vivo cytokine production capacity) were compared in patients undergoing elective BCS (n = 20) versus mastectomy (n = 20).ResultsEx vivo cytokine production capacity of TNF, IL-6 and IL-1β was nearly absent in both groups one hour after surgery. Levels appeared recovered on postoperative day 3 (POD3), with significantly higher ex vivo production capacity of IL-1β after BCS (p = .041) compared to mastectomy. Plasma concentration of IL-6 was higher one hour after mastectomy (p = .045). Concentrations of plasma alarmins S100A8/A9 and S100A12 were significantly higher on POD3 after mastectomy (p = .003 and p = .041, respectively). Regression analysis showed a significantly lower percentage of NOL measurements ≤ 8 (absence of nociception) during mastectomy when corrected for norepinephrine equivalents (36% versus 45% respectively, p = .038). Percentage of NOL measurements ≤ 8 of all patients correlated with ex vivo cytokine production capacity of IL-1β and TNF on POD3 (r = .408; p = .011 and r = .500; p = .001, respectively).ConclusionsThis pilot study revealed substantial early postoperative immune suppression after BCS and mastectomy that appears to recover in the following days. Differences between BCS and mastectomy in release of DAMPs and intraoperative sympathetic activation could affect postoperative immune homeostasis and thereby contribute to the better survival reported after BCS in previous large population-based retrospective trials. These results endorse further exploration of (1) S100 alarmins as potential therapeutic targets in breast cancer surgery and (2) suppression of intraoperative sympathetic activation to substantiate the observed association with postoperative immune dysregulation.

Improved Immune Response for Colorectal Cancer Therapy Triggered by Multifunctional Nanocomposites with Self-Amplifying Antitumor Ferroptosis.

Ferroptosis, as a type of regulated cell death, can trigger the release of damage-associated molecular patterns from cancer cells and lead to the enhancement of immune recognition. Fenton reaction-mediated chemodynamic therapy could initiate ferroptosis by generating lipid peroxides, but its efficiency would be greatly restricted by the insufficient H2O2 and antioxidant system within the tumor. Herein, this work reports the successful preparation of H2O2 self-supplied and glutathione (GSH)-depletion therapeutic nanocomposites (Cu2O@Au) through in situ growth of Au nanoparticles on the surface of cuprous oxide (Cu2O) nanospheres. Upon delivery into cancer cells, the released Cu2O could consume endogenous H2S within colorectal cancer cells to form Cu31S16 nanoparticles, while the released Au NPs could catalyze glucose to generate H2O2 and gluconic acid. The self-supplying endogenous H2O2 and lower acidity could amplify the Cu ion-induced Fenton-like reaction. Meanwhile, the consumption of glucose would reduce GSH generation by disrupting the pentose phosphate pathway. Additionally, the Cu2+/Cu+ catalytic cycle promotes the depletion of GSH, leading to lipid peroxide accumulation and ferroptosis. It was found that the onset of ferroptosis triggered by Cu2O@Au could initiate immunologic cell death, promote dendritic cell maturation and T-cell infiltration, and finally enhance the antitumor efficacy of the PD-L1 antibody. In summary, this collaborative action produces a remarkable antitumor effect, which provides a promising treatment strategy for colorectal cancer.

Impaired systemic proteostasis and peripheral immune cell dysfunction in kidney diseases

ABSTRACT Kidney diseases, encompassing a spectrum of either acute or chronic disorders, manifest complex systemic repercussions beyond renal dysfunction. These include a reduced efficacy of tissue proteostasis mechanisms to control protein synthesis, folding, and degradation in both the renal and extra-renal compartments. Emerging research has revealed a pivotal interplay between proteostasis and immune regulation in the pathogenesis of kidney diseases, along with their cardiovascular, immunometabolic, and organ dysfunction symptoms. This review outlines the multifaceted connections between proteostasis dysregulation and immune dysfunction in kidney disease onset and progression. The crosstalk between the proteostasis network and immune cells orchestrates a bidirectional communication that amplifies pathological cascades, exacerbating kidney injury and impairing organ resilience. Furthermore, the article focuses on the implications of systemic proteostasis defects in modulating immune responses in extra-renal tissues underscore the systemic nature of kidney diseases. The disruption of proteostasis mechanisms triggers the release of damage-associated molecular patterns (DAMPs) and inflammatory mediators, perpetuating a state of heightened immune activation, contributing to systemic complications in affected individuals. Understanding the intricate interaction between proteostasis and immune regulation in kidney diseases, including both chronic and acute forms, promises novel therapeutic interventions. Targeting proteostasis pathways to restore cellular homeostasis and modulating immune responses could offer innovative strategies to mitigate renal damage and ameliorate systemic complications associated with kidney diseases. Harnessing this knowledge may also pave the way for the development of more efficient dialysis therapies and interventions with sorbents and hemoperfusion methods, to improve the clinical outcome of the patients.

Erythronecroptosis: an overview of necroptosis or programmed necrosis in red blood cells.

Necroptosis is considered a programmed necrosis that requires receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 3 (RIPK3), and pore-forming mixed lineage kinase domain-like protein (MLKL) to trigger a regulated cell membrane lysis. Membrane rupture in necroptosis has been shown to fuel innate immune response due to release of damage-associated molecular patterns (DAMPs). Recently published studies indicate that mature erythrocytes can undergo necroptosis as well. In this review, we provide an outline of multiple cell death modes occurring in erythrocytes, discuss possible immunological aspects of diverse erythrocyte cell deaths, summarize available evidence related to the ability of erythrocytes to undergo necroptosis, outline key involved molecular mechanisms, and discuss the potential implication of erythrocyte necroptosis in the physiology and pathophysiology. Furthermore, we aim to highlight the interplay between necroptosis and eryptosis signaling in erythrocytes, emphasizing specific characteristics of these pathways distinct from their counterparts in nucleated cells. Thus, our review provides a comprehensive summary of the current knowledge of necroptosis in erythrocytes. To reflect critical differences between necroptosis of nucleated cells and necroptosis of erythrocytes, we suggest a term erythronecroptosis for necroptosis of enucleated cells.

Potentiating Immunogenic Cell Death in Cold Tumor with Functional Living Materials of FeAu-Methylene Blue Composites.

Low immunogenicity, absence of tumor-infiltrating lymphocytes and immunosuppressive microenvironment of immune cold tumors are the main bottlenecks leading to unfavorable prognosis. Here, an integrated tumor bioimaging and multimodal therapeutic strategy is developed, which converts immune cold into hot by modulating oxidative stress levels, enhancing photo-killing efficacy, inducing immunogenic cell death and inhibiting the immune checkpoint. On that occasion, the unique tumor microenvironment can be harnessed to biosynthesize in situ self-assembly iron complexes and fluorescent gold nanoclusters from metal ions Fe(II) and Au(III) for active targeting and real-time visualization of the tumors, simultaneously regulating reactive oxygen species levels within tumors via peroxidase-like activity. Furthermore, methylene blue (MB)-mediated photodynamic therapy promotes the release of damage-associated molecular patterns (DAMPs), which acts as in situ tumor vaccine and further induces dendritic cells maturation, augments the infiltration of antitumor T cells and significantly impedes the primary tumor growth and proliferation. More strikingly, by synergizing with the programmed cell death receptor-1 (PD-1) checkpoint inhibitor, the immunosuppressive microenvironment is remodeled and the survival time of model mice is prolonged. In summary, this paradigm utilizes the tumor-specific microenvironment to boost robust and durable systemic antitumor immunity, providing a novel opportunity for precision cancer theranostics.

Modulation of Abundance and Location of High-Mobility Group Box 1 in Human Microglia and Macrophages under Oxygen-Glucose Deprivation.

While stroke represents one of the main causes of death worldwide, available effective drug treatment options remain limited to classic thrombolysis with recombinant tissue plasminogen activator (rtPA) for arterial-clot occlusion. Following stroke, multiple pathways become engaged in producing a vicious proinflammatory cycle through the release of damage-associated molecular patterns (DAMPs) such as high-mobility group box 1 (HMGB1) and heat shock protein 70 kDa (HSP72). HMGB1, in particular, can activate proinflammatory cytokine production when acetylated (AcHMGB1), a form that prefers cytosolic localization and extracellular release. This study aimed at determining how HMGB1 and HSP72 are modulated and affected following treatment with the anti-inflammatory compound resveratrol and novel platelet membrane-derived nanocarriers loaded with rtPA (CSM@rtPA) recently developed by our group for ischemic artery recanalization. Under ischemic conditions of oxygen-glucose deprivation (OGD), nuclear abundance of HMGB1 and AcHMGB1 in microglia and macrophages decreased, whereas treatment with CSM@rtPA did not alter nuclear or cytosolic abundance. Resveratrol treatment markedly increased the cytosolic abundance of HSP72 in microglia. Using proximity ligation assays, we determined that HSP72 interacted with HMGB1 and with acetylated HMGB1. The interaction was differentially affected under the OGD conditions. Resveratrol treatment under the OGD further decreased HSP72-HMGB1 interactions, whereas, in contrast, treatment increased HSP72-AcHMGB1 interactions in microglia. This study points out a salient molecular interaction suited for a two-pronged nanotherapeutic intervention in stroke: enhancement of rtPA's thrombolytic activity and modulation of cytosolic interactions between HMGB1 and HSP72 by resveratrol.

"Multi-in-One" Yolk-Shell Structured Nanoplatform Inducing Pyroptosis and Antitumor Immune Response Through Cascade Reactions.

Pyroptosis, a new mode of regulatory cell death, holds a promising prospect in tumor therapy. The occurrence of pyroptosis can trigger the release of damage-associated molecular patterns (DAMPs) and activate the antitumor immune response. Moreover, enhancing intracellular reactive oxygen species (ROS) generation can effectively induce pyroptosis. Herein, an integrated nanoplatform (hCZAG) based on zeolitic imidazolate framework-8 (ZIF-8) with Cu2+ and Zn2+ as active nodes and glucose oxidase (GOx) loading is constructed to evoke pyroptosis. GOx can effectively elevate intracellular hydrogen peroxide (H2 O2 ) levels to regulate the unfavorable tumor microenvironment (TME). Cu2+ can be reduced to Cu+ by endogenous overexpressed GSH and both Cu2+ and Cu+ can exert Fenton-like activity to promote ROS generation and amplify oxidative stress. In addition, the accumulation of Cu2+ leads to the aggregation of lipoylated dihydrolipoamide S-acetyltransferase (DLAT), thus resulting in cuproptosis. Notably, the outburst of ROS induced by hCZAG activates Caspase-1 proteins, leads to the cleavage of gasdermin D (GSDMD), and induces pyroptosis. Pyroptosis further elicits an adaptive immune response, leading to immunogenic cell death (ICD). This study provides effective strategies for triggering pyroptosis-mediated immunotherapy and achieving improved therapeutic effects.