Ménage à Trois in stress: DAMPs, redox and autophagy

Selenium-containing polyurethane nanofibers with MnO2 nanoparticles and gelsevirine promote diabetic wound healing by modulation of ROS and inflammation

Reactive oxygen species (ROS) and subsequent inflammatory cascades hinder the healing of diabetic wounds, which should be tackled simultaneously when designing wound dressings. In this study, ROS-responsive di‑selenium-containing polyurethane nanofibers (PUF) loaded with manganese dioxide nanoparticles (MnO2 NPs) and gelsevirine (GSV) with an average diameter of 0.6 ± 10 μm, were prepared to specifically target ROS and inflammation control, thereby enhancing healing in diabetic wounds. The resulting nanofibers exhibited a porous architecture and enhanced drug delivery capability. The MnO2/GSV/PUF dressing showed negligible cytotoxicity with cell viability over 80 %, effective ROS-scavenging ability of 87 %, and inhibition of pro-inflammatory cytokine expression. This dual mechanism of ROS-scavenging and inflammation modulation accelerated the healing of diabetic wounds up to 92 % in 14 d in a full-thickness diabetic wound model, as evidenced by reduced cytokine levels, enhanced epithelialization, and uniform collagen deposition with the highest percentage of 60 %.

Igniting hope: Harnessing NLRP3 inflammasome-GSDMD-mediated pyroptosis for cancer immunotherapy

In the contemporary landscape of oncology, immunotherapy, represented by immune checkpoint blockade (ICB) therapy, stands out as a beacon of innovation in cancer treatment. Despite its promise, the therapy's progression is hindered by suboptimal clinical response rates. Addressing this challenge, the modulation of the NLRP3 inflammasome-GSDMD-mediated pyroptosis pathway holds promise as a means to augment the efficacy of immunotherapy. In the pathway, the NLRP3 inflammasome serves as a pivotal molecular sensor that responds to inflammatory stimuli within the organism. Its activation leads to the release of cytokines interleukin 1β and interleukin 18 through the cleavage of GSDMD, thereby forming membrane pores and potentially resulting in pyroptosis. This cascade of processes exerts a profound impact on tumor development and progression, with its function and expression exhibiting variability across different tumor types and developmental stages. Consequently, understanding the specific roles of the NLRP3 inflammasome and GSDMD-mediated pyroptosis in diverse tumors is imperative for comprehending tumorigenesis and crafting precise therapeutic strategies. This review aims to elucidate the structure and activation mechanisms of the NLRP3 inflammasome, as well as the induction mechanisms of GSDMD-mediated pyroptosis. Additionally, we provide a comprehensive overview of the involvement of this pathway in various cancer types and its applications in tumor immunotherapy, nanotherapy, and other fields. Emphasis is placed on the feasibility of leveraging this approach to enhance ICB therapy within the field of immunotherapy. Furthermore, we discuss the potential applications of this pathway in other immunotherapy methods, such as chimeric antigen receptor T-cell (CAR-T) therapy and tumor vaccines.

Ferroptosis: principles and significance in health and disease

Ferroptosis, an iron-dependent form of cell death characterized by uncontrolled lipid peroxidation, is governed by molecular networks involving diverse molecules and organelles. Since its recognition as a non-apoptotic cell death pathway in 2012, ferroptosis has emerged as a crucial mechanism in numerous physiological and pathological contexts, leading to significant therapeutic advancements across a wide range of diseases. This review summarizes the fundamental molecular mechanisms and regulatory pathways underlying ferroptosis, including both GPX4-dependent and -independent antioxidant mechanisms. Additionally, we examine the involvement of ferroptosis in various pathological conditions, including cancer, neurodegenerative diseases, sepsis, ischemia-reperfusion injury, autoimmune disorders, and metabolic disorders. Specifically, we explore the role of ferroptosis in response to chemotherapy, radiotherapy, immunotherapy, nanotherapy, and targeted therapy. Furthermore, we discuss pharmacological strategies for modulating ferroptosis and potential biomarkers for monitoring this process. Lastly, we elucidate the interplay between ferroptosis and other forms of regulated cell death. Such insights hold promise for advancing our understanding of ferroptosis in the context of human health and disease.

Berberine alleviated contrast-induced acute kidney injury by mitophagy-mediated NLRP3 inflammasome inactivation in a mice model

The incidence of contrast-induced acute kidney injury (CI-AKI) has escalated to become the third most prevalent cause of hospital-acquired AKI, with a lack of efficacious interventions. Berberine (BBR) possesses diverse pharmacological effects and exhibits renoprotective properties; however, limited knowledge exists regarding its impact on CI-AKI. Therefore, our study aimed to investigate the protective effects and underlying mechanisms of BBR on CI-AKI in a mice model, focusing on the nucleotide-binding oligomerization domain-like pyrin domain-containing protein 3 (NLRP3) inflammasome and mitophagy. The CI-AKI mice model was established by administering NG-nitro-L-arginine methyl ester (L-NAME) (10 mg/kg), indomethacin (10 mg/kg), and iohexol (11 g/kg) following water deprivation. A pretreatment of 100 mg/kg of BBR was orally administered to the mice for two weeks. Renal injury markers, damage-associated molecular patterns (DAMPs), renal histopathology, mitochondrial morphology, autophagosomes, and potential mechanisms were investigated. BBR effectively reduced levels of renal injury biomarkers such as serum cystatin C, urea nitrogen, and creatinine, downregulated the protein level of kidney injury molecule 1 (KIM1), and mitigated renal histomorphological damage. Moreover, BBR reduced DAMPs, including high mobility group box-1 (HMGB1), heat shock protein 70 (HSP70), and uric acid (UA). It also alleviated oxidative stress and inflammatory factors such as monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β). Furthermore, the activation of NLRP3 inflammasome was attenuated in the BBR pretreatment group, as evidenced by both mRNA and protein levels. Electron microscopy and western blotting examination revealed that BBR mitigated mitochondrial damage and enhanced mitophagy. Additionally, BBR increased the P-AMPK/AMPK ratio. These findings indicated that BBR exerted a protective effect against CI-AKI by suppressing NLRP3 inflammasome activation and modulating mitophagy, providing a potential therapeutic strategy for its prevention.

METTL14 downregulation drives S100A4+ monocyte-derived macrophages via MyD88/NF-κB pathway to promote MAFLD progression

Without intervention, a considerable proportion of patients with metabolism-associated fatty liver disease (MAFLD) will progress from simple steatosis to metabolism-associated steatohepatitis (MASH), liver fibrosis, and even hepatocellular carcinoma. However, the molecular mechanisms that control progressive MAFLD have yet to be fully determined. Here, we unraveled that the expression of the N6-methyladenosine (m6A) methyltransferase METTL14 is remarkably downregulated in the livers of both patients and several murine models of MAFLD, whereas hepatocyte-specific depletion of this methyltransferase aggravated lipid accumulation, liver injury, and fibrosis. Conversely, hepatic Mettl14 overexpression alleviated the above pathophysiological changes in mice fed on a high-fat diet (HFD). Notably, in vivo and in vitro mechanistic studies indicated that METTL14 downregulation decreased the level of GLS2 by affecting the translation efficiency mediated by YTHDF1 in an m6A-depedent manner, which might help to form an oxidative stress microenvironment and accordingly recruit Cx3cr1+Ccr2+ monocyte-derived macrophages (Mo-macs). In detail, Cx3cr1+Ccr2+ Mo-macs can be categorized into M1-like macrophages and S100A4-positive macrophages and then further activate hepatic stellate cells (HSCs) to promote liver fibrosis. Further experiments revealed that CX3CR1 can activate the transcription of S100A4 via CX3CR1/MyD88/NF-κB signaling pathway in Cx3cr1+Ccr2+ Mo-macs. Restoration of METTL14 or GLS2, or interfering with this signal transduction pathway such as inhibiting MyD88 could ameliorate liver injuries and fibrosis. Taken together, these findings indicate potential therapies for the treatment of MAFLD progression.

SKA3 targeted therapies in cancer precision surgery: bridging bench discoveries to clinical applications - review article

Spindle and kinetochore-associated complex subunit 3 (SKA3) is a microtubule-binding subcomplex of the outer kinetochore, which plays a vital role in proper chromosomal segregation and cell division. Recently, SKA3 have been demonstrated its oncogenic role of tumorigenesis and development in cancers. In this review, the authors comprehensively deciphered SKA3 in human cancer from various aspects, including bibliometrics, pan-cancer analysis, and narrative summary. The authors also provided the top 10 predicted drugs targeting SKA3. The authors proposed that SKA3 was a potential target and brought new therapeutic opportunities for cancer patients.

Targeting paraptosis in cancer: opportunities and challenges

Cell death can be classified into two primary categories: accidental cell death and regulated cell death (RCD). Within RCD, there are distinct apoptotic and non-apoptotic cell death pathways. Among the various forms of non-apoptotic RCD, paraptosis stands out as a unique mechanism characterized by distinct morphological changes within cells. These alterations encompass cytoplasmic vacuolization, organelle swelling, notably in the endoplasmic reticulum and mitochondria, and the absence of typical apoptotic features, such as cell shrinkage and DNA fragmentation. Biochemically, paraptosis distinguishes itself by its independence from caspases, which are conventionally associated with apoptotic death. This intriguing cell death pathway can be initiated by various cellular stressors, including oxidative stress, protein misfolding, and specific chemical compounds. Dysregulated paraptosis plays a pivotal role in several critical cancer-related processes, such as autophagic degradation, drug resistance, and angiogenesis. This review provides a comprehensive overview of recent advancements in our understanding of the mechanisms and regulation of paraptosis. Additionally, it delves into the potential of paraptosis-related compounds for targeted cancer treatment, with the aim of enhancing treatment efficacy while minimizing harm to healthy cells.

High glucose-induced STING activation inhibits diabetic wound healing through promoting M1 polarization of macrophages

Diabetic wound (DW) is characterized by elevated pro-inflammatory cytokines and cellular dysfunction consistent with elevated reactive oxygen species (ROS) levels. Recent advances in immunology have dissected molecular pathways involved in the innate immune system where cytoplasmic DNA can trigger STING-dependent inflammatory responses and play an important role in metabolic-related diseases. We investigated whether STING regulates inflammation and cellular dysfunction in DW healing. We found that STING and M1 macrophages were increased in wound tissues from DW in patients and mice and delayed the wound closure. We also noticed that the massively released ROS in the High glucose (HG) environment activated STING signaling by inducing the escape of mtDNA to the cytoplasm, inducing macrophage polarization into a pro-inflammatory phenotype, releasing pro-inflammatory cytokines, and exacerbating endothelial cell dysfunction. In Conclusion, mtDNA-cGAS-STING pathway activation under diabetic metabolic stress is an important mechanism of DW refractory healing. While using STING gene-edited macrophages for wound treatment by cell therapy can induce the polarization of wound macrophages from pro-inflammatory M1 to anti-inflammatory M2, promote angiogenesis, and collagen deposition to accelerate DW healing. STING may be a promising therapeutic target for DW.

Role of high-mobility group box 1 in cancer

High-mobility group box 1 (HMGB1) is a non-histone nuclear protein in most eukaryocytes. Inside the nucleus, HMGB1 plays an important role in several DNA events such as DNA repair, transcription, telomere maintenance, and genome stability. While outside the nucleus, it fulfils more complicated functions, including promoting cell proliferation, inflammation, angiogenesis, immune tolerance and immune escape, which may play a pro-tumoral role.Meanwhile, HMGB1 acts as an anti-tumoral protein by regulating immune cell recruitment and inducing immunogenic cell death (ICD) during the carcinogenesis process. Therefore, abnormal expression of HMGB1 is associated with oncogenesis, development, and metastasis of cancer, which may play a dual role of pro-tumor and anti-tumor.

Synergy of nanodiamond-doxorubicin conjugates and PD-L1 blockade effectively turns tumor-associated macrophages against tumor cells

Background

Tumor-associated macrophages (TAMs) are the most abundant stromal cells in the tumor microenvironment. Turning the TAMs against their host tumor cells is an intriguing therapeutic strategy particularly attractive for patients with immunologically “cold” tumors. This concept was mechanistically demonstrated on in vitro human and murine lung cancer cells and their corresponding TAM models through combinatorial use of nanodiamond-doxorubicin conjugates (Nano-DOX) and a PD-L1 blocking agent BMS-1. Nano-DOX are an agent previously proved to be able to stimulate tumor cells’ immunogenicity and thereby reactivate the TAMs into the anti-tumor M1 phenotype.

Results

Nano-DOX were first shown to stimulate the tumor cells and the TAMs to release the cytokine HMGB1 which, regardless of its source, acted through the RAGE/NF-κB pathway to induce PD-L1 in the tumor cells and PD-L1/PD-1 in the TAMs. Interestingly, Nano-DOX also induced NF-κB-dependent RAGE expression in the tumor cells and thus reinforced HMGB1’s action thereon. Then, BMS-1 was shown to enhance Nano-DOX-stimulated M1-type activation of TAMs both by blocking Nano-DOX-induced PD-L1 in the TAMs and by blocking tumor cell PD-L1 ligation with TAM PD-1. The TAMs with enhanced M1-type repolarization both killed the tumor cells and suppressed their growth. BMS-1 could also potentiate Nano-DOX’s action to suppress tumor cell growth via blocking of Nano-DOX-induced PD-L1 therein. Finally, Nano-DOX and BMS-1 achieved synergistic therapeutic efficacy against in vivo tumor grafts in a TAM-dependent manner.

Conclusions

PD-L1/PD-1 upregulation mediated by autocrine and paracrine activation of the HMGB1/RAGE/NF-κB signaling is a key response of lung cancer cells and their TAMs to stress, which can be induced by Nano-DOX. Blockade of Nano-DOX-induced PD-L1, both in the cancer cells and the TAMs, achieves enhanced activation of TAM-mediated anti-tumor response.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-01017-w.

Involvement of Alarmins in the Pathogenesis and Progression of Multiple Myeloma

OBJECTIVE

Multiple Myeloma (MM) is a haematological disease resulting from the neoplastic transformation of plasma cells. The uncontrolled growth of plasma cells in the bone marrow and the delivery of several cytokines causes bone erosion that often does not regress, even in the event of disease remission. MM is characterised by a multi-step evolutionary path, which starts with an early asymptomatic stage defined as monoclonal gammopathy of undetermined significance (MGUS) evolving to overt disease.

DATA SOURCES AND STUDY SELECTION

We have selected scientific publications on the specific topics "alarmis, MGUS, and MM", drawing from PubMed. The keywords we used were alarmines, MGUS, MM, and immune system.

RESULTS

The analysis confirms the pivotal role of molecules such as high-mobility group box-1, heat shock proteins, and S100 proteins in the induction of neoangiogenesis, which represents a milestone in the negative evolution of MM as well as other haematological and non-haematological tumours.

CONCLUSIONS

Modulation of the host immune system and the inhibition of neoangiogenesis may represent the therapeutic target for the treatment of MM that is capable of promoting better survival and reducing the risk of RRMM.

Targeting Neuroinflammation in Brain Cancer: Uncovering Mechanisms, Pharmacological Targets, and Neuropharmaceutical Developments

Gliomas are one of the most lethal types of cancers accounting for ∼80% of all central nervous system (CNS) primary malignancies. Among gliomas, glioblastomas (GBM) are the most aggressive, characterized by a median patient survival of fewer than 15  months. Recent molecular characterization studies uncovered the genetic signatures and methylation status of gliomas and correlate these with clinical prognosis. The most relevant molecular characteristics for the new glioma classification are IDH mutation, chromosome 1p/19q deletion, histone mutations, and other genetic parameters such as ATRX loss, TP53, and TERT mutations, as well as DNA methylation levels. Similar to other solid tumors, glioma progression is impacted by the complex interactions between the tumor cells and immune cells within the tumor microenvironment. The immune system’s response to cancer can impact the glioma’s survival, proliferation, and invasiveness. Salient characteristics of gliomas include enhanced vascularization, stimulation of a hypoxic tumor microenvironment, increased oxidative stress, and an immune suppressive milieu. These processes promote the neuro-inflammatory tumor microenvironment which can lead to the loss of blood-brain barrier (BBB) integrity. The consequences of a compromised BBB are deleteriously exposing the brain to potentially harmful concentrations of substances from the peripheral circulation, adversely affecting neuronal signaling, and abnormal immune cell infiltration; all of which can lead to disruption of brain homeostasis. In this review, we first describe the unique features of inflammation in CNS tumors. We then discuss the mechanisms of tumor-initiating neuro-inflammatory microenvironment and its impact on tumor invasion and progression. Finally, we also discuss potential pharmacological interventions that can be used to target neuro-inflammation in gliomas.

Gas plasma irradiation of breast cancers promotes immunogenicity, tumor reduction, and an abscopal effect in vivo

While many new and emerging therapeutic concepts have appeared throughout the last decades, cancer still is fatal in many patients. At the same time, the importance of immunology in oncotherapy is increasingly recognized, not only since the advent of checkpoint therapy. Among the many types of tumors, also breast cancer has an immunological dimension that might be exploited best by increasing the immunogenicity of the tumors in the microenvironment. To this end, we tested a novel therapeutic concept, gas plasma irradiation, for its ability to promote the immunogenicity and increase the toxicity of breast cancer cells in vitro and in vivo. Mechanistically, this emerging medical technology is employing a plethora of reactive oxygen species being deposited on the target cells and tissues. Using 2D cultures and 3D tumor spheroids, we found gas plasma-irradiation to drive apoptosis and immunogenic cancer cell death (ICD) in vitro, as evidenced by an increased expression of calreticulin, heat-shock proteins 70 and 90, and MHC-I. In 4T1 breast cancer-bearing mice, the gas plasma irradiation markedly decreased tumor burden and increased survival. Interestingly, non-treated tumors injected in the opposite flank of mice exposed to our novel treatment also exhibited reduced growth, arguing for an abscopal effect. This was concomitant with an increase of apoptosis and tumor-infiltrating CD4⁺ and CD8⁺ T-cells as well as dendritic cells in the tissues. In summary, we found gas plasma-irradiated murine breast cancers to induce toxicity and augmented immunogenicity, leading to reduced tumor growth at a site remote to the treatment area.

The pathogenicity, structural and functional exploration of human HMGB1 single nucleotide polymorphisms using in silico study

The human HMGB1 gene mutations have a major impact on several immune-related diseases and cancer. The detrimental effect of non-synonymous mutations of HMGB1 has not been investigated yet, hence the present study aims to examine single nucleotide polymorphisms and their implications on the structure-function of human HMGB1. The multifaceted HMGB1 protein acts as pleiotropic cytokine and regulates essential genes for coordinated cellular functions. The mutational effect on HMGB1 was analyzed by sequence-based homology methods, supervised learning methods, and structure-based methods. The study identified 58 non-synonymous mutations in human HMGB1, out of which only 2 mutations; R10T (rs61742222) and F103C (rs61733675) were classified as the SNPs with highest deleterious and disease-causing mutants. The effect of these mutations in structure of HMGB1 was scrutinized and the R10T mutant found to have a distinct structural behaviour in the B-box domain. In addition, R10T mutant predicted that it affects the MoRF function of HMGB1 and it could disrupt the DNA binding or/and protein partner interaction activity by HMGB1. F103C mutation takes place at the TLR binding and cytokine inducing region of HMGB1, hence it could affect the protein binding activity which involves in many cellular signaling. The study identified potent mutations R10T (a cancer-causing somatic mutation) and F103C (a novel mutation) and these mutations either directly or indirectly hinder DNA binding activity and TLR and cytokine binding of HMGB1. These findings will help in understanding the molecular basis of these promising mutations and functional role of human HMGB1 in cancer and immunological diseases.AbbreviationsAGERAdvanced glycosylation end product-specific receptorCXCLChemokine (C-X-C motif) liganddbSNPThe single nucleotide polymorphism databaseHMGB1High mobility group box 1LINCSLINear Constraint SolverMDSMolecular dynamics simulationMoRFMolecular recognition featuresNPTNumber of particle, Pressure and TemperatureNVTNumber of particle, Volume and TemperaturensSNPNon-synonymous SNPPBCPartial boundary conditionPCAPrincipal component analysisPMEPartial mesh EwaldRMSDRoot mean square deviationRMSFRoot mean square fluctuationSNPSingle nucleotide polymorphismSPCSingle-point chargeTLRToll-like receptorUTRUn-translated RegionCommunicated by Ramaswamy H. Sarma.

High mobility group box 1 (HMGB1): a pivotal regulator of hematopoietic malignancies

High mobility group box 1 (HMGB1) is a nonhistone chromatin-associated protein that has been widely reported to play a pivotal role in the pathogenesis of hematopoietic malignancies. As a representative damage-associated molecular pattern (DAMP), HMGB1 normally exists inside cells but can be secreted into the extracellular environment through passive or active release. Extracellular HMGB1 binds with several different receptors and interactors to mediate the proliferation, differentiation, mobilization, and senescence of hematopoietic stem cells (HSCs). HMGB1 is also involved in the formation of the inflammatory bone marrow (BM) microenvironment by activating proinflammatory signaling pathways. Moreover, HMGB1-dependent autophagy induces chemotherapy resistance in leukemia and multiple myeloma. In this review, we systematically summarize the emerging roles of HMGB1 in carcinogenesis, progression, prognosis, and potential clinical applications in different hematopoietic malignancies. In summary, targeting the regulation of HMGB1 activity in HSCs and the BM microenvironment is highly beneficial in the diagnosis and treatment of various hematopoietic malignancies.

The VE-PTP Inhibitor AKB-9778 Improves Antitumor Activity and Diminishes the Toxicity of Interleukin 2 (IL-2) Administration

Administration of interleukin (IL)-2 has led to a durable response in patients with advanced renal cancer and melanoma but is restricted for clinical application because of adverse effects, including the vascular leak syndrome (VLS). VLS is associated with increased circulating levels of the Tie2 antagonist ligand, angiopoietin 2, and decreased Tie2 receptor phosphorylation and downstream signaling in endothelial cells (ECs). Given that vascular endothelial protein tyrosine phosphatase (VE-PTP) is a specific membrane phosphatase in ECs that dephosphorylates Tie2, the effects of targeting VE-PTP by a selective inhibitor AKB-9778 (AKB) in terms of VLS and antitumor efficacy were examined in this study. The authors found, by targeting VE-PTP, that the antitumor effects induced by IL-2 were augmented [tumor-free 44% (IL-2 alone) vs. 87.5% (IL-2+AKB)], associated with enhanced immune cell infiltrate (90% increase for CD8 T cells and natural killer cells). In addition, the side effects of IL-2 therapy were lessened, as demonstrated by diminished lung weight (less vascular leakage) as well as reduced cytokine levels (serum HMGB1 from 137.04±2.69 to 43.86±3.65 pg/mL; interferon-γ from 590.52±90.52 to 31.37±1.14 pg/mL). The authors further sought to determine the potential mechanism of the action of AKB-9778. The findings suggest that AKB-9778 may function through reducing serum angiopoietin 2 level and regulating EC viability. These findings provide insights into the targeting VE-PTP to improve tolerance and efficacy of IL-2 therapy and highlight the clinical potential of AKB-9778 for treating patients with VLS and cancer.

Johnny on the Spot-Chronic Inflammation Is Driven by HMGB1

Although much has been made of the role of HMGB1 acting as an acute damage associated molecular pattern (DAMP) molecule, prompting the response to tissue damage or injury, it is also released at sites of chronic inflammation including sites of infection, autoimmunity, and cancer. As such, the biology is distinguished from homeostasis and acute inflammation by the recruitment and persistence of myeloid derived suppressor cells, T regulatory cells, fibrosis and/or exuberant angiogenesis depending on the antecedents and the other individual inflammatory partners that HMGB1 binds and focuses, including IL-1β, CXCL12/SDF1, LPS, DNA, RNA, and sRAGE. High levels of HMGB1 released into the extracellular milieu and its persistence in the microenvironment can contribute to the pathogenesis of many if not all autoimmune disorders and is a key factor that drives inflammation further and worsens symptoms. HMGB1 is also pivotal in the maintenance of chronic inflammation and a “wound healing” type of immune response that ultimately contributes to the onset of carcinogenesis and tumor progression. Exosomes carrying HMGB1 and other instructive molecules are released and shape the response of various cells in the chronic inflammatory environment. Understanding the defining roles of REDOX, DAMPs and PAMPs, and the host response in chronic inflammation requires an alternative means for positing HMGB1's central role in limiting and focusing inflammation, distinguishing chronic from acute inflammation.

Intercellular communications-redox interactions in radiation toxicity; potential targets for radiation mitigation

Nowadays, using ionizing radiation (IR) is necessary for clinical, agricultural, nuclear energy or industrial applications. Accidental exposure to IR after a radiation terror or disaster poses a threat to human. In contrast to the old dogma of radiation toxicity, several experiments during the last two recent decades have revealed that intercellular signaling and communications play a key role in this procedure. Elevated level of cytokines and other intercellular signals increase oxidative damage and inflammatory responses via reduction/oxidation interactions (redox system). Intercellular signals induce production of free radicals and inflammatory mediators by some intermediate enzymes such as cyclooxygenase-2 (COX-2), nitric oxide synthase (NOS), NADPH oxidase, and also via triggering mitochondrial ROS. Furthermore, these signals facilitate cell to cell contact and increasing cell toxicity via cohort effect. Nitric oxide is a free radical with ability to act as an intercellular signal that induce DNA damage and changes in some signaling pathways in irradiated as well as non-irradiated adjacent cells. Targeting of these mediators by some anti-inflammatory agents or via antioxidants such as mitochondrial ROS scavengers opens a window to mitigate radiation toxicity after an accidental exposure. Experiments which have been done so far suggests that some cytokines such as IL-1β, TNF-α, TGF-β, IL-4 and IL-13 are some interesting targets that depend on irradiated organs and may help mitigate radiation toxicity. Moreover, animal experiments in recent years indicated that targeting of toll like receptors (TLRs) may be more useful for radioprotection and mitigation. In this review, we aimed to describe the role of intercellular interactions in oxidative injury, inflammation, cell death and killing effects of IR. Moreover, we described evidence on potential mitigation of radiation injury via targeting of these mediators.

Origin and Consequences of Necroinflammation

When cells undergo necrotic cell death in either physiological or pathophysiological settings in vivo, they release highly immunogenic intracellular molecules and organelles into the interstitium and thereby represent the strongest known trigger of the immune system. With our increasing understanding of necrosis as a regulated and genetically determined process (RN, regulated necrosis), necrosis and necroinflammation can be pharmacologically prevented. This review discusses our current knowledge about signaling pathways of necrotic cell death as the origin of necroinflammation. Multiple pathways of RN such as necroptosis, ferroptosis, and pyroptosis have been evolutionary conserved most likely because of their differences in immunogenicity. As the consequence of necrosis, however, all necrotic cells release damage associated molecular patterns (DAMPs) that have been extensively investigated over the last two decades. Analysis of necroinflammation allows characterizing specific signatures for each particular pathway of cell death. While all RN-pathways share the release of DAMPs in general, most of them actively regulate the immune system by the additional expression and/or maturation of either pro- or anti-inflammatory cytokines/chemokines. In addition, DAMPs have been demonstrated to modulate the process of regeneration. For the purpose of better understanding of necroinflammation, we introduce a novel classification of DAMPs in this review to help detect the relative contribution of each RN-pathway to certain physiological and pathophysiological conditions.

High mobility group box 1 as a biomarker in critically ill patients

BACKGROUND

Extracellular release of high mobility group box 1 (HMGB1) acts as a danger-associated molecular pattern, thereby "alarming" the immune system and promoting systemic inflammation. We investigated plasma HMGB1 concentrations as a potential diagnostic and prognostic biomarker in critical illness.

METHODS

Our study included 218 critically ill patients (145 with sepsis, 73 without sepsis), of whom blood samples were obtained at the time-point of admission to the medical intensive care unit (ICU).

RESULTS

High mobility group box 1 levels were significantly elevated in critically ill patients (n = 218) compared with healthy controls (n = 66). Elevated HMGB1 plasma levels were independent from the presence of sepsis. Moreover, HMGB1 was not associated with disease severity, organ failure, or mortality in the ICU. We observed a trend toward lower HMGB1 levels in ICU patients with pre-existing obesity, type 2 diabetes and end-stage renal disease patients on chronic hemodialysis.

CONCLUSION

In conclusion, our study did not reveal significant associations between HMGB1 levels at ICU admission and clinical outcomes in critically ill patients. Due to the pathogenic role of HMGB1 in the late phases of experimental sepsis, future studies might assess the potential value of HMGB1 by measuring its plasma concentrations at later time points during the course of critical illness.

Trial watch: Immunogenic cell death induction by anticancer chemotherapeutics

The expression "immunogenic cell death" (ICD) refers to a functionally unique form of cell death that facilitates (instead of suppressing) a T cell-dependent immune response specific for dead cell-derived antigens. ICD critically relies on the activation of adaptive responses in dying cells, culminating with the exposure or secretion of immunostimulatory molecules commonly referred to as "damage-associated molecular patterns". Only a few agents can elicit bona fide ICD, including some clinically established chemotherapeutics such as doxorubicin, epirubicin, idarubicin, mitoxantrone, bleomycin, bortezomib, cyclophosphamide and oxaliplatin. In this Trial Watch, we discuss recent progress on the development of ICD-inducing chemotherapeutic regimens, focusing on studies that evaluate clinical efficacy in conjunction with immunological biomarkers.

Inflammation and premature aging in advanced chronic kidney disease

Systemic inflammation in end-stage renal disease is an established risk factor for mortality and a catalyst for other complications, which are related to a premature aging phenotype, including muscle wasting, vascular calcification, and other forms of premature vascular disease, depression, osteoporosis, and frailty. Uremic inflammation is also mechanistically related to mechanisms involved in the aging process, such as telomere shortening, mitochondrial dysfunction, and altered nutrient sensing, which can have a direct effect on cellular and tissue function. In addition to uremia-specific causes, such as abnormalities in the phosphate-Klotho axis, there are remarkable similarities between the pathophysiology of uremic inflammation and so-called "inflammaging" in the general population. Potentially relevant, but still somewhat unexplored in this respect, are abnormal or misplaced protein structures, as well as abnormalities in tissue homeostasis, which evoke danger signals through damage-associated molecular patterns, as well as the senescence-associated secretory phenotype. Systemic inflammation, in combination with the loss of kidney function, can impair the resilience of the body to external and internal stressors by reduced functional and structural tissue reserves, and by impairing normal organ crosstalk, thus providing an explanation for the greatly increased risk of homeostatic breakdown in this population. In this review, the relationship between uremic inflammation and a premature aging phenotype, as well as potential causes and consequences, are discussed.

Suppression of MyD88-dependent signaling alleviates neuropathic pain induced by peripheral nerve injury in the rat

BACKGROUND

MyD88 is the adaptor protein of MyD88-dependent signaling pathway of TLRs and IL-1 receptor and regulates innate immune response. However, it was not clear whether and how MyD88 and related signaling pathways in the dorsal root ganglion (DRG) and spinal dorsal horn (SDH) are involved in neuropathic pain.

METHODS

Chronic constriction injury (CCI) was used to induce neuropathic pain in the rat. The expression of MyD88, TRIF, IBA1, and GFAP was detected with immunofluorescent staining and Western blot. The expression of interleukin-1 beta (IL-1β), high mobility group box 1 (HMGB1), NF-κB-p65, phosphorylated NF-κB-p65, ERK, phosphorylated ERK, and tumor necrosis factor-alpha (TNF-α) was detected with Western blot. Pain-related behavioral effects of MyD88 homodimerization inhibitory peptide (MIP) were accessed up to 3 weeks after intrathecal administration.

RESULTS

Peripheral nerve injury significantly increased the protein level of MyD88 in the DRG and SDH, but had no effect on TRIF. MyD88 was found partly distributed in the nociceptive neurons in the DRGs and the astrocytes and microglia in the SDH. HMGB1 and IL-1β were also found upregulated in nociceptive pathways of CCI rats. Intrathecal application of MIP significantly alleviated mechanical and thermal hyperalgesia in the CCI rats and also reversed CCI-induced upregulation of MyD88 in both DRG and SDH. Further investigation revealed that suppression of MyD88 protein reduced the release of TNF-α and glial activation in the SDH in the CCI rats.

CONCLUSIONS

MyD88-dependent TIR pathway in the DRG and SDH may play a role in CCI-induced neuropathic pain. MyD88 might serve as a potential therapeutic target for neuropathic pain.

Emerging role of HMGB1 in lung diseases: friend or foe

Lung diseases remain a serious problem for public health. The immune status of the body is considered to be the main influencing factor for the progression of lung diseases. HMGB1 (high‐mobility group box 1) emerges as an important molecule of the body immune network. Accumulating data have demonstrated that HMGB1 is crucially implicated in lung diseases and acts as independent biomarker and therapeutic target for related lung diseases. This review provides an overview of updated understanding of HMGB1 structure, release styles, receptors and function. Furthermore, we discuss the potential role of HMGB1 in a variety of lung diseases. Further exploration of molecular mechanisms underlying the function of HMGB1 in lung diseases will provide novel preventive and therapeutic strategies for lung diseases.

Aging and Lung Disease. Clinical Impact and Cellular and Molecular Pathways

With the expected rapid growth of the aging population worldwide, there is a clear need to understand the complex process of aging to develop interventions that might extend the health span in this group of patients. Aging is associated with increased susceptibility to a variety of chronic diseases, and lung pathologies are no exception. The prevalence of lung diseases such as idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease has been found to increase considerably with age. In October 2014, the Division of Pulmonary, Allergy, and Critical Care of the University of Pittsburgh cohosted the Pittsburgh-Munich Lung Conference focused in aging and lung disease with the Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Ludwig-Maximilians University and Helmholtz Zentrum Munich Germany. The purpose of the conference was to disseminate novel concepts in aging mechanisms that have an impact in lung physiology and pathogenesis of pulmonary diseases that commonly occur in older populations. The conference included 28 presentations on diverse topics, which are summarized in this report. The participants identified priorities for future basic and translational investigations that will assist in the identification of molecular insights involved in the pathogenesis of age-related pulmonary diseases and the design of therapeutic interventions for these lung conditions.

Gut mucosal DAMPs in IBD: from mechanisms to therapeutic implications

Endogenous damage-associated molecular patterns (DAMPs) are released during tissue damage and have increasingly recognized roles in the etiology of many human diseases. The inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn's disease (CD), are immune-mediated conditions where high levels of DAMPs are observed. DAMPs such as calprotectin (S100A8/9) have an established clinical role as a biomarker in IBD. In this review, we use IBD as an archetypal common chronic inflammatory disease to focus on the conceptual and evidential importance of DAMPs in pathogenesis and why DAMPs represent an entirely new class of targets for clinical translation.

Role of Redox Status in Development of Glioblastoma

Glioblastoma multiforme (GBM) is a highly aggressive neoplasia, prognosis remains dismal, and current therapy is mostly palliative. There are no known risk factors associated with gliomagenesis; however, it is well established that chronic inflammation in brain tissue induces oxidative stress in astrocytes and microglia. High quantities of reactive species of oxygen into the cells can react with several macromolecules, including chromosomal and mitochondrial DNA, leading to damage and malfunction of DNA repair enzymes. These changes bring genetic instability and abnormal metabolic processes, favoring oxidative environment and increase rate of cell proliferation. In GBM, a high metabolic rate and increased basal levels of reactive oxygen species play an important role as chemical mediators in the regulation of signal transduction, protecting malignant cells from apoptosis, thus creating an immunosuppressive environment. New redox therapeutics could reduce oxidative stress preventing cellular damage and high mutation rate accompanied by chromosomal instability, reducing the immunosuppressive environment. In addition, therapies directed to modulate redox rate reduce resistance and moderate the high rate of cell proliferation, favoring apoptosis of tumoral cells. This review describes the redox status in GBM, and how this imbalance could promote gliomagenesis through genomic and mitochondrial DNA damage, inducing the pro-oxidant and proinflammatory environment involved in tumor cell proliferation, resistance, and immune escape. In addition, some therapeutic agents that modulate redox status and might be advantageous in therapy against GBM are described.

High Mobility Group B Proteins, Their Partners, and Other Redox Sensors in Ovarian and Prostate Cancer

Cancer cells try to avoid the overproduction of reactive oxygen species by metabolic rearrangements. These cells also develop specific strategies to increase ROS resistance and to express the enzymatic activities necessary for ROS detoxification. Oxidative stress produces DNA damage and also induces responses, which could help the cell to restore the initial equilibrium. But if this is not possible, oxidative stress finally activates signals that will lead to cell death. High mobility group B (HMGB) proteins have been previously related to the onset and progressions of cancers of different origins. The protein HMGB1 behaves as a redox sensor and its structural changes, which are conditioned by the oxidative environment, are associated with different functions of the protein. This review describes recent advances in the role of human HMGB proteins and other proteins interacting with them, in cancerous processes related to oxidative stress, with special reference to ovarian and prostate cancer. Their participation in the molecular mechanisms of resistance to cisplatin, a drug commonly used in chemotherapy, is also revised.

Molecular and Translational Classifications of DAMPs in Immunogenic Cell Death

The immunogenicity of malignant cells has recently been acknowledged as a critical determinant of efficacy in cancer therapy. Thus, besides developing direct immunostimulatory regimens, including dendritic cell-based vaccines, checkpoint-blocking therapies, and adoptive T-cell transfer, researchers have started to focus on the overall immunobiology of neoplastic cells. It is now clear that cancer cells can succumb to some anticancer therapies by undergoing a peculiar form of cell death that is characterized by an increased immunogenic potential, owing to the emission of the so-called “damage-associated molecular patterns” (DAMPs). The emission of DAMPs and other immunostimulatory factors by cells succumbing to immunogenic cell death (ICD) favors the establishment of a productive interface with the immune system. This results in the elicitation of tumor-targeting immune responses associated with the elimination of residual, treatment-resistant cancer cells, as well as with the establishment of immunological memory. Although ICD has been characterized with increased precision since its discovery, several questions remain to be addressed. Here, we summarize and tabulate the main molecular, immunological, preclinical, and clinical aspects of ICD, in an attempt to capture the essence of this phenomenon, and identify future challenges for this rapidly expanding field of investigation.

Heme Oxygenase-1 Gene Therapy Provides Cardioprotection Via Control of Post-Ischemic Inflammation: An Experimental Study in a Pre-Clinical Pig Model

BACKGROUND

Heme oxygenase-1 (HO-1) is an inducible stress-responsive enzyme converting heme to bilirubin, carbon monoxide, and free iron, which exerts anti-inflammatory and antiapoptotic effects. Although efficient cardioprotection after HO-1 overexpression has been reported in rodents, its role in attenuating post-ischemic inflammation is unclear.

OBJECTIVES

This study assessed the efficacy of recombinant adenoassociated virus (rAAV)-encoding human heme oxygenase-1 (hHO-1) in attenuating post-ischemic inflammation in a murine and a porcine ischemia/reperfusion model.

METHODS

Murine ischemia was induced by 45 min of left anterior descending occlusion, followed by 24 h of reperfusion and functional as well as fluorescent-activated cell sorting analysis. Porcine hearts were subjected to 60 min of ischemia and 24h of reperfusion before hemodynamic and histologic analyses were performed.

RESULTS

Human microvascular endothelial cells transfected with hHO-1 displayed an attenuated interleukin-6 and intercellular adhesion molecule 1 expression, resulting in reduced monocytic THP-1 cell recruitment in vitro. In murine left anterior descending occlusion and reperfusion, the post-ischemic influx of CD45(+) leukocytes, Ly-6G(+) neutrophils, and Ly-6C(high) monocytes was further exacerbated in HO-1-deficient hearts and reversed by rAAV.hHO-1 treatment. Conversely, in our porcine model of ischemia, the post-ischemic influx of myeloperoxidase-positive neutrophils and CD14(+) monocytes was reduced by 49% and 87% after rAAV.hHO-1 transduction, similar to hHO-1 transgenic pigs. Functionally, rAAV.hHO-1 and hHO-1 transgenic left ventricles displayed a smaller loss of ejection fraction than control animals.

CONCLUSIONS

Whereas HO-1 deficiency exacerbates post-ischemic cardiac inflammation in mice, hHO-1 gene therapy attenuates inflammation after ischemia and reperfusion in murine and porcine hearts. Regional hHO-1 gene therapy provides cardioprotection in a pre-clinical porcine ischemia/reperfusion model.

Hydrogen peroxide - production, fate and role in redox signaling of tumor cells

Hydrogen peroxide (H₂O₂) is involved in various signal transduction pathways and cell fate decisions. The mechanism of the so called “redox signaling” includes the H₂O₂-mediated reversible oxidation of redox sensitive cysteine residues in enzymes and transcription factors thereby altering their activities. Depending on its intracellular concentration and localization, H₂O₂ exhibits either pro- or anti-apoptotic activities. In comparison to normal cells, cancer cells are characterized by an increased H₂O₂ production rate and an impaired redox balance thereby affecting the microenvironment as well as the anti-tumoral immune response. This article reviews the current knowledge about the intracellular production of H₂O₂ along with redox signaling pathways mediating either the growth or apoptosis of tumor cells. In addition it will be discussed how the targeting of H₂O₂-linked sources and/or signaling components involved in tumor progression and survival might lead to novel therapeutic targets.

Redox distress and genetic defects conspire in systemic autoinflammatory diseases

Inflammation is initiated by innate immune cell activation after contact with pathogens or tissue injury. An increasing number of observations have suggested that cellular stress, in the absence of infection or evident damage, can also induce inflammation. Thus, inflammation can be triggered by exogenous pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs)-so-called classic inflammation-or by endogenous stress resulting from tissue or cellular dysfunction. External triggers and cellular stress activate the same molecular pathways, possibly explaining why classic and stress-induced inflammation have similar clinical manifestations. In some systemic autoinflammatory diseases (SAIDs), inflammatory cells exhibit reduction-oxidation (redox) distress, having high levels of reactive oxygen species (ROS), which promote proinflammatory cytokine production and contribute to the subversion of mechanisms that self-limit inflammation. Thus, SAIDs can be viewed as a paradigm of stress-related inflammation, being characterized by recurrent flares or chronic inflammation (with no recognizable external triggers) and by a failure to downmodulate this inflammation. Here, we review SAID pathophysiology, focusing on the major cytokines and DAMPs, and on the key roles of redox distress. New therapeutic opportunities to tackle SAIDs by blocking stress-induced pathways and control the response to stress in patients are also discussed.

The redox biology network in cancer pathophysiology and therapeutics

The review pinpoints operational concepts related to the redox biology network applied to the pathophysiology and therapeutics of solid tumors. A sophisticated network of intrinsic and extrinsic cues, integrated in the tumor niche, drives tumorigenesis and tumor progression. Critical mutations and distorted redox signaling pathways orchestrate pathologic events inside cancer cells, resulting in resistance to stress and death signals, aberrant proliferation and efficient repair mechanisms. Additionally, the complex inter-cellular crosstalk within the tumor niche, mediated by cytokines, redox-sensitive danger signals (HMGB1) and exosomes, under the pressure of multiple stresses (oxidative, inflammatory, metabolic), greatly contributes to the malignant phenotype. The tumor-associated inflammatory stress and its suppressive action on the anti-tumor immune response are highlighted. We further emphasize that ROS may act either as supporter or enemy of cancer cells, depending on the context. Oxidative stress-based therapies, such as radiotherapy and photodynamic therapy, take advantage of the cytotoxic face of ROS for killing tumor cells by a non-physiologically sudden, localized and intense oxidative burst. The type of tumor cell death elicited by these therapies is discussed. Therapy outcome depends on the differential sensitivity to oxidative stress of particular tumor cells, such as cancer stem cells, and therefore co-therapies that transiently down-regulate their intrinsic antioxidant system hold great promise. We draw attention on the consequences of the damage signals delivered by oxidative stress-injured cells to neighboring and distant cells, and emphasize the benefits of therapeutically triggered immunologic cell death in metastatic cancer. An integrative approach should be applied when designing therapeutic strategies in cancer, taking into consideration the mutational, metabolic, inflammatory and oxidative status of tumor cells, cellular heterogeneity and the hypoxia map in the tumor niche, along with the adjoining and systemic effects of oxidative stress-based therapies.

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Critical point mutations and distorted redox-sensitive signaling pathways underlie the tumorigenic phenotype.

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Inter-cellular crosstalk under stress conditions in the tumor niche drives the behavior of tumor cells.

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ROS may act as either as supporter or enemy of tumor cells, depending on the context.

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Oxidative stress-injured cells deliver danger signals to neighboring and distant cells, hence dictating the outcome of therapy in cancer.

Circulating HMGB1 and RAGE as Clinical Biomarkers in Malignant and Autoimmune Diseases

High molecular group box 1 (HMGB1) is a highly conserved member of the HMG-box-family; abundantly expressed in almost all human cells and released in apoptosis; necrosis or by activated immune cells. Once in the extracellular space, HMGB1 can act as a danger associated molecular pattern (DAMP), thus stimulating or inhibiting certain functions of the immune system; depending on the “combinatorial cocktail” of the surrounding milieu. HMGB1 exerts its various functions through binding to a multitude of membrane-bound receptors such as TLR-2; -4 and -9; IL-1 and RAGE (receptor for advanced glycation end products); partly complex-bound with intracellular fragments like nucleosomes. Soluble RAGE in the extracellular space, however, acts as a decoy receptor by binding to HMGB1 and inhibiting its effects. This review aims to outline today’s knowledge of structure, intra- and extracellular functions including mechanisms of release and finally the clinical relevance of HMGB1 and RAGE as clinical biomarkers in therapy monitoring, prediction and prognosis of malignant and autoimmune disease.

The role of autophagy in vascular biology

There is increasing interest in the role of autophagic flux in maintaining normal vessel wall biology and a growing suspicion that autophagic dysregulation may be a common pathway through which vascular aging and associated pathologies develop. Within endothelial and smooth muscle cells, diverse but important triggers that range from oxidized lipids to β-amyloid seem to stimulate autophagosome formation potently. In addition, emerging evidence links autophagy to a wide array of vascular processes ranging from angiogenesis to calcification of the vessel wall. Alterations in autophagic flux are also increasingly being implicated in disease processes that include both atherosclerosis and pulmonary hypertension. Finally, recent insights point toward an important role of autophagy in the paracrine regulation of vasoactive substances from the endothelium. Here, we review the progress in understanding how autophagy can contribute to vascular biology and the emerging strategies to target this process for therapeutic benefit.

The PERKs of damage-associated molecular patterns mediating cancer immunogenicity: From sensor to the plasma membrane and beyond

Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) are emerging as key adaptation mechanisms in response to loss of proteostasis, with major cell autonomous and non-autonomous functions impacting cancer progression and therapeutic responses. In recent years, vital physiological roles of the ER in maintenance of proteostasis, Ca(2+) signaling and trafficking through the secretory pathway have emerged. Some of these functions have been shown to be decisive for mobilizing certain signals from injured/dying cancer cells in response to certain anticancer treatments, toward the plasma membrane and ultimately emit them into the extracellular environment, where they may act as danger signals. The spatiotemporally defined emission of these signals, better known as damage-associated molecular patterns (DAMPs), distinguishes this type of cancer cell death from physiological apoptosis, which is tolerogenic in nature, thereby enabling these dying cancer cells to alert the immune system and "re-activate" antitumor immunity. The emission of DAMPs, decisive for immunogenic cell death (ICD) and which include the ER chaperone calreticulin and ATP, is reliant on a danger signaling module induced by certain assorted anticancer treatments through oxidative-ER stress. The main focus of this review is to discuss the emerging role of ER-stress regulated pathways and processes in danger signaling thereby regulating the cancer cell-immune cell interface by the extracellular emission of DAMPs. In particular, we discuss signaling contexts existing upstream and around PERK, a major ER-stress sensor in ICD context, which have not been emphatically discussed in the context of antitumor immunity and ICD up until now. Finally, we briefly discuss the pros and cons of targeting PERK in the context of ICD.

Endogenous molecules induced by a pathogen-associated molecular pattern (PAMP) elicit innate immunity in shrimp

Invertebrates rely on an innate immune system to combat invading pathogens. The system is initiated in the presence of cell wall components from microbes like lipopolysaccharide (LPS), β-1,3-glucan (βG) and peptidoglycan (PG), altogether known as pathogen-associated molecular patterns (PAMPs), via a recognition of pattern recognition protein (PRP) or receptor (PRR) through complicated reactions. We show herein that shrimp hemocytes incubated with LPS, βG, and PG caused necrosis and released endogenous molecules (EMs), namely EM-L, EM-β, and EM-P, and found that shrimp hemocytes incubated with EM-L, EM-β, and EM-P caused changes in cell viability, degranulation and necrosis of hemocytes, and increased phenoloxidase (PO) activity and respiratory burst (RB) indicating activation of immunity in vitro. We found that shrimp receiving EM-L, EM-β, and EM-P had increases in hemocyte count and other immune parameters as well as higher phagocytic activity toward a Vibrio pathogen, and found that shrimp receiving EM-L had increases in proliferation cell ratio and mitotic index of hematopoietic tissues (HPTs). We identified proteins of EMs deduced from SDS-PAGE and LC-ESI-MS/MS analyses. EM-L and EM-P contained damage-associated molecular patterns (DAMPs) including HMGBa, HMGBb, histone 2A (H2A), H2B, and H4, and other proteins including proPO, Rab 7 GPTase, and Rab 11 GPTase, which were not observed in controls (EM-C, hemocytes incubated in shrimp salt solution). We concluded that EMs induced by PAMPs contain DAMPs and other immune molecules, and they could elicit innate immunity in shrimp. Further research is needed to identify which individual molecule or combined molecules of EMs cause the results, and determine the mechanism of action in innate immunity.

The immediate protective response to microbial challenge

The innate immune system detects infection and tissue injury through different families of pattern-recognition receptors (PRRs), such as Toll-like receptors. Most PRR-mediated responses initiate elaborate processes of signaling, transcription, translation, and secretion of effector mediators, which together require time to achieve. Therefore, PRR-mediated processes are not active in the early phases of infection. These considerations raise the question of how the host limits microbial replication and invasion during this critical period. Here, we examine the crucial defense mechanisms, such as antimicrobial peptides or extracellular traps, typically activated within minutes of the initial infection phase, which we term the "immediate protective response". Deficiencies in different components of the immediate protective response are often associated with severe and recurrent infectious diseases in humans, highlighting their physiologic importance.

High mobility group box 1 (HMGB1) phenotypic role revealed with stress

High mobility group box 1 (HMGB1) is an evolutionarily ancient protein that is present in one form or another in all eukaryotes. It fundamentally resides in the nucleus but translocates to the cytosol with stress and is subsequently released into the extracellular space. HMGB1 global knockout mice exhibit lethal hypoglycemia, whereas tissues and cells from conditional knockout or knock-in mice are born alive without apparent significant functional deficit. An aberrant response to targeted stress in the liver, pancreas, heart or myeloid cells is consistent with a protective role for HMGB1 in sustaining nuclear homeostasis and enabling other stress responses, including autophagy. Under some conditions, HMGB1 is not required for liver and heart function. Many challenges remain with respect to understanding the multiple roles of HMGB1 in health and disease.

Autophagy in cellular transformation, survival and communication with the tumor microenvironment

Autophagy describes several metabolic pathways, by which cytoplasmic constituents are imported into lysosomes for degradation. These pathways and in particular macroautophagy play an important role during oncogenesis by apparently inhibiting cellular transformation initially, but then ensuring tumor cell survival in established cancers. Furthermore, the conditioning of the tumor microenvironment, including the cross-talk with the immune system, is influenced by autophagy. These multiple facets of autophagy regulation in tumors will be discussed in the series of review articles of this issue of Seminars in Cancer Biology. A comprehensive understanding of this pathway in oncology is needed to efficiently apply autophagy regulating tumor therapies, which are already in use.