Extracellular Vesicles and Damage-Associated Molecular Patterns: A Pandora's Box in Health and Disease

Environmental pollutants and exosomes: A new paradigm in environmental health and disease

This study investigates the intricate interplay between environmental pollutants and exosomes, shedding light on a novel paradigm in environmental health and disease. Cellular stress, induced by environmental toxicants or disease, significantly impacts the production and composition of exosomes, crucial mediators of intercellular communication. The heat shock response (HSR) and unfolded protein response (UPR) pathways, activated during cellular stress, profoundly influence exosome generation, cargo sorting, and function, shaping intercellular communication and stress responses. Environmental pollutants, particularly lipophilic ones, directly interact with exosome lipid bilayers, potentially affecting membrane stability, release, and cellular uptake. The study reveals that exposure to environmental contaminants induces significant changes in exosomal proteins, miRNAs, and lipids, impacting cellular function and health. Understanding the impact of environmental pollutants on exosomal cargo holds promise for biomarkers of exposure, enabling non-invasive sample collection and real-time insights into ongoing cellular responses. This research explores the potential of exosomal biomarkers for early detection of health effects, assessing treatment efficacy, and population-wide screening. Overcoming challenges requires advanced isolation techniques, standardized protocols, and machine learning for data analysis. Integration with omics technologies enhances comprehensive molecular analysis, offering a holistic understanding of the complex regulatory network influenced by environmental pollutants. The study underscores the capability of exosomes in circulation as promising biomarkers for assessing environmental exposure and systemic health effects, contributing to advancements in environmental health research and disease prevention.

Extracellular vesicles as human therapeutics: A scoping review of the literature

Extracellular vesicles (EVs) are released by all cells and contribute to cell-to-cell communication. The capacity of EVs to target specific cells and to efficiently deliver a composite profile of functional molecules have led researchers around the world to hypothesize their potential as therapeutics. While studies of EV treatment in animal models are numerous, their actual clinical benefit in humans has more slowly started to be tested. In this scoping review, we searched PubMed and other databases up to 31 December 2023 and, starting from 13,567 records, we selected 40 pertinent published studies testing EVs as therapeutics in humans. The analysis of those 40 studies shows that they are all small pilot trials with a large heterogeneity in terms of administration route and target disease. Moreover, the absence of a placebo control in most of the studies, the predominant local application of EV formulations and the inconsistent administration dose metric still impede comparison across studies and firm conclusions about EV safety and efficacy. On the other hand, the recording of some promising outcomes strongly calls out for well-designed larger studies to test EVs as an alternative approach to treat human diseases with no or few therapeutic options.

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.

The complexity of extracellular vesicles: Bridging the gap between cellular communication and neuropathology

Brain-derived extracellular vesicles (EVs) serve a prominent role in maintaining homeostasis and contributing to pathology in health and disease. This review establishes a crucial link between physiological processes leading to EV biogenesis and their impacts on disease. EVs are involved in the clearance and transport of proteins and nucleic acids, responding to changes in cellular processes associated with neurodegeneration, including autophagic disruption, organellar dysfunction, aging, and other cell stresses. In neurodegenerative disorders (e.g., Alzheimer's disease, Parkinson's disease, etc.), EVs contribute to the spread of pathological proteins like amyloid β, tau, ɑ-synuclein, prions, and TDP-43, exacerbating neurodegeneration and accelerating disease progression. Despite evidence for both neuropathological and neuroprotective effects of EVs, the mechanistic switch between their physiological and pathological functions remains elusive, warranting further research into their involvement in neurodegenerative disease. Moreover, owing to their innate ability to traverse the blood-brain barrier and their ubiquitous nature, EVs emerge as promising candidates for novel diagnostic and therapeutic strategies. The review uniquely positions itself at the intersection of EV cell biology, neurophysiology, and neuropathology, offering insights into the diverse biological roles of EVs in health and disease.

When Our Best Friend Becomes Our Worst Enemy: The Mitochondrion in Trauma, Surgery, and Critical Illness

Common for major surgery, multitrauma, sepsis, and critical illness, is a whole-body inflammation. Tissue injury is able to trigger a generalized inflammatory reaction. Cell death causes release of endogenous structures termed damage associated molecular patterns (DAMPs) that initiate a sterile inflammation. Mitochondria are evolutionary endosymbionts originating from bacteria, containing molecular patterns similar to bacteria. These molecular patterns are termed mitochondrial DAMPs (mDAMPs). Mitochondrial debris released into the extracellular space or into the circulation is immunogenic and damaging secondary to activation of the innate immune system. In the circulation, released mDAMPS are either free or exist in extracellular vesicles, being able to act on every organ and cell in the body. However, the role of mDAMPs in trauma and critical care is not fully clarified. There is a complete lack of knowledge how they may be counteracted in patients. Among mDAMPs are mitochondrial DNA, cardiolipin, N-formyl peptides, cytochrome C, adenosine triphosphate, reactive oxygen species, succinate, and mitochondrial transcription factor A. In this overview, we present the different mDAMPs, their function, release, targets, and inflammatory potential. In light of present knowledge, the role of mDAMPs in the pathophysiology of major surgery and trauma as well as sepsis, and critical care is discussed.

Self-DNA driven inflammation in COVID-19 and after mRNA-based vaccination: lessons for non-COVID-19 pathologies

The coronavirus disease 2019 (COVID-19) pandemic triggered an unprecedented concentration of economic and research efforts to generate knowledge at unequalled speed on deregulated interferon type I signalling and nuclear factor kappa light chain enhancer in B-cells (NF-κB)-driven interleukin (IL)-1β, IL-6, IL-18 secretion causing cytokine storms. The translation of the knowledge on how the resulting systemic inflammation can lead to life-threatening complications into novel treatments and vaccine technologies is underway. Nevertheless, previously existing knowledge on the role of cytoplasmatic or circulating self-DNA as a pro-inflammatory damage-associated molecular pattern (DAMP) was largely ignored. Pathologies reported 'de novo' for patients infected with Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 to be outcomes of self-DNA-driven inflammation in fact had been linked earlier to self-DNA in different contexts, e.g., the infection with Human Immunodeficiency Virus (HIV)-1, sterile inflammation, and autoimmune diseases. I highlight particularly how synergies with other DAMPs can render immunogenic properties to normally non-immunogenic extracellular self-DNA, and I discuss the shared features of the gp41 unit of the HIV-1 envelope protein and the SARS-CoV 2 Spike protein that enable HIV-1 and SARS-CoV-2 to interact with cell or nuclear membranes, trigger syncytia formation, inflict damage to their host's DNA, and trigger inflammation - likely for their own benefit. These similarities motivate speculations that similar mechanisms to those driven by gp41 can explain how inflammatory self-DNA contributes to some of most frequent adverse events after vaccination with the BNT162b2 mRNA (Pfizer/BioNTech) or the mRNA-1273 (Moderna) vaccine, i.e., myocarditis, herpes zoster, rheumatoid arthritis, autoimmune nephritis or hepatitis, new-onset systemic lupus erythematosus, and flare-ups of psoriasis or lupus. The hope is to motivate a wider application of the lessons learned from the experiences with COVID-19 and the new mRNA vaccines to combat future non-COVID-19 diseases.

Mitochondrial DNA leakage triggers inflammation in age-related cardiovascular diseases

Mitochondrial dysfunction is one of the hallmarks of cardiovascular aging. The leakage of mitochondrial DNA (mtDNA) is increased in senescent cells, which are resistant to programmed cell death such as apoptosis. Due to its similarity to prokaryotic DNA, mtDNA could be recognized by cellular DNA sensors and trigger innate immune responses, resulting in chronic inflammatory conditions during aging. The mechanisms include cGAS-STING signaling, TLR-9 and inflammasomes activation. Mitochondrial quality controls such as mitophagy could prevent mitochondria from triggering harmful inflammatory responses, but when this homeostasis is out of balance, mtDNA-induced inflammation could become pathogenic and contribute to age-related cardiovascular diseases. Here, we summarize recent studies on mechanisms by which mtDNA promotes inflammation and aging-related cardiovascular diseases, and discuss the potential value of mtDNA in early screening and as therapeutic targets.

Involvement of Extracellular Vesicles in the Proinflammatory Response to Clozapine: Implications for Clozapine-Induced Agranulocytosis

Most idiosyncratic drug reactions (IDRs) appear to be immune-mediated, but mechanistic events preceding severe reaction onset remain poorly defined. Damage-associated molecular patterns (DAMPs) may contribute to both innate and adaptive immune phases of IDRs, and changes in extracellular vesicle (EV) cargo have been detected post-exposure to several IDR-associated drugs. To explore the hypothesis that EVs are also a source of DAMPs in the induction of the immune response preceding drug-induced agranulocytosis, the proteome and immunogenicity of clozapine- (agranulocytosis-associated drug) and olanzapine- (non-agranulocytosis-associated drug) exposed EVs were compared in two preclinical models: THP-1 macrophages and Sprague-Dawley rats. Compared with olanzapine, clozapine induced a greater increase in the concentration of EVs enriched from both cell culture media and rat serum. Moreover, treatment of drug-naïve THP-1 cells with clozapine-exposed EVs induced an inflammasome-dependent response, supporting a potential role for EVs in immune activation. Proteomic and bioinformatic analyses demonstrated an increased number of differentially expressed proteins with clozapine that were enriched in pathways related to inflammation, myeloid cell chemotaxis, wounding, transforming growth factor-β signaling, and negative regulation of stimuli response. These data indicate that, although clozapine and olanzapine exposure both alter the protein cargo of EVs, clozapine-exposed EVs carry mediators that exhibit significantly greater immunogenicity. Ultimately, this supports the working hypothesis that drugs associated with a risk of IDRs induce cell stress, release of proinflammatory mediators, and early immune activation that precedes severe reaction onset. Further studies characterizing EVs may elucidate biomarkers that predict IDR risk during development of drug candidates. SIGNIFICANCE STATEMENT: This work demonstrates that clozapine, an idiosyncratic drug-induced agranulocytosis (IDIAG)-associated drug, but not olanzapine, a safer structural analogue, induces an acute proinflammatory response and increases extracellular vesicle (EV) release in two preclinical models. Moreover, clozapine-exposed EVs are more immunogenic, as measured by their ability to activate inflammasomes, and contain more differentially expressed proteins, highlighting a novel role for EVs during the early immune response to clozapine and enhancing our mechanistic understanding of IDIAG and other idiosyncratic reactions.

The role of extracellular vesicle fusion with target cells in triggering systemic inflammation

Extracellular vesicles (EVs) play a crucial role in intercellular communication by transferring bioactive molecules from donor to recipient cells. As a result, EV fusion leads to the modulation of cellular functions and has an impact on both physiological and pathological processes in the recipient cell. This study explores the impact of EV fusion on cellular responses to inflammatory signaling. Our findings reveal that fusion renders non-responsive cells susceptible to inflammatory signaling, as evidenced by increased NF-κB activation and the release of inflammatory mediators. Syntaxin-binding protein 1 is essential for the merge and activation of intracellular signaling. Subsequent analysis show that EVs transfer their functionally active receptors to target cells, making them prone to an otherwise unresponsive state. EVs in complex with their agonist, require no further stimulation of the target cells to trigger mobilization of NF-κB. While receptor antagonists were unable to inhibit NF-κB activation, blocking of the fusion between EVs and their target cells with heparin mitigated inflammation in mice challenged with EVs.

The interplay between neuroinflammatory pathways and Parkinson's disease

Parkinson's disease, a progressive neurodegenerative disorder predominantly affecting elderly, is marked by the gradual degeneration of the nigrostriatal dopaminergic pathway, culminating in neuronal loss within the substantia nigra pars compacta (SNpc) and dopamine depletion. At the molecular level, neuronal loss in the SNpc has been attributed to factors including neuroinflammation, impaired protein homeostasis, as well as mitochondrial dysfunction and the resulting oxidative stress. This review focuses on the interplay between neuroinflammatory pathways and Parkinson's disease, drawing insights from current literature.

Interactions between mitochondrial dysfunction and other hallmarks of aging: Paving a path toward interventions that promote healthy old age

Current research on human aging has largely been guided by the milestone paper "hallmarks of aging," which were first proposed in the seminal 2013 paper by Lopez-Otin et al. Most studies have focused on one aging hallmark at a time, asking whether the underlying molecular perturbations are sufficient to drive the aging process and its associated phenotypes. More recently, researchers have begun to investigate whether aging phenotypes are driven by concurrent perturbations in molecular pathways linked to not one but to multiple hallmarks of aging and whether they present different patterns in organs and systems over time. Indeed, preliminary results suggest that more complex interactions between aging hallmarks must be considered and addressed, if we are to develop interventions that successfully promote healthy aging and/or delay aging-associated dysfunction and diseases. Here, we summarize some of the latest work and views on the interplay between hallmarks of aging, with a specific focus on mitochondrial dysfunction. Indeed, this represents a significant example of the complex crosstalk between hallmarks of aging and of the effects that an intervention targeted to a specific hallmark may have on the others. A better knowledge of these interconnections, of their cause-effect relationships, of their spatial and temporal sequence, will be very beneficial for the whole aging research field and for the identification of effective interventions in promoting healthy old age.

Communication Regarding the Myocardial Ischemia/Reperfusion and Cognitive Impairment: A Narrative Literature Review

Coronary artery disease is a prevalent ischemic disease that results in insufficient blood supply to the heart muscle due to narrowing or occlusion of the coronary arteries. Various reperfusion strategies, including pharmacological thrombolysis and percutaneous coronary intervention, have been developed to enhance blood flow restoration. However, these interventions can lead to myocardial ischemia/reperfusion injury (MI/RI), which can cause unpredictable complications. Recent research has highlighted a compelling association between MI/RI and cognitive function, revealing pathophysiological mechanisms that may explain altered brain cognition. Manifestations in the brain following MI/RI exhibit pathological features resembling those observed in Alzheimer's disease (AD), implying a potential link between MI/RI and the development of AD. The pro-inflammatory state following MI/RI may induce neuroinflammation via systemic inflammation, while impaired cardiac function can result in cerebral under-perfusion. This review delves into the role of extracellular vesicles in transporting deleterious substances from the heart to the brain during conditions of MI/RI, potentially contributing to impaired cognition. Addressing the cognitive consequence of MI/RI, the review also emphasizes potential neuroprotective interventions and pharmacological treatments within the MI/RI model. In conclusion, the review underscores the significant impact of MI/RI on cognitive function, summarizes potential mechanisms of cardio-cerebral communication in the context of MI/RI, and offers ideas and insights for the prevention and treatment of cognitive dysfunction following MI/RI.

What role do extracellular vesicles play in developing physical frailty and sarcopenia? : A systematic review

BACKGROUND

Frailty and sarcopenia are typical geriatric conditions with a complex pathophysiology. Extracellular vesicles (EVs) are key regulators of age-related diseases, but the mechanisms underlying physical frailty, sarcopenia, and EVs are not well understood.

METHODS

A systematic literature review was conducted to examine the evidence supporting an association between EVs and physical frailty and/or sarcopenia by searching the electronic databases, including the Cochrane Library, PubMed, and Embase, from January 2000 to January 2021.

RESULTS

A total of 216 cross-sectional studies were retrieved, and after the removal of 43 duplicate records, the title and abstract of 167 articles were screened, identifying 6 relevant articles for full-text review. Of the studies five met the inclusion criteria, and heterogeneity among studies was high. There is controversy regarding whether frailty and/or sarcopenia are related to circulating EV levels; however, the cargo of EVs has been associated with frailty and sarcopenia in various ways, such as microRNAs, mitochondrial-derived vesicles (MDVs), and protein cargoes.

CONCLUSION

Recent studies, although limited, depicted that EVs could be one of the underlying mechanisms of frailty and/or sarcopenia. There is a possibility that physical frailty and sarcopenia may have specific EV concentrations and cargo profiles; however, further research is required to fully understand the mechanisms and identify potential biomarkers and early preventative strategies for physical frailty and sarcopenia.

Mitophagy in human health, ageing and disease

Maintaining optimal mitochondrial function is a feature of health. Mitophagy removes and recycles damaged mitochondria and regulates the biogenesis of new, fully functional ones preserving healthy mitochondrial functions and activities. Preclinical and clinical studies have shown that impaired mitophagy negatively affects cellular health and contributes to age-related chronic diseases. Strategies to boost mitophagy have been successfully tested in model organisms, and, recently, some have been translated into clinics. In this Review, we describe the basic mechanisms of mitophagy and how mitophagy can be assessed in human blood, the immune system and tissues, including muscle, brain and liver. We outline mitophagy's role in specific diseases and describe mitophagy-activating approaches successfully tested in humans, including exercise and nutritional and pharmacological interventions. We describe how mitophagy is connected to other features of ageing through general mechanisms such as inflammation and oxidative stress and forecast how strengthening research on mitophagy and mitophagy interventions may strongly support human health.

A blunted TH17 cytokine signature in women with mild cognitive impairment: insights from inflammatory profiling of a community-based cohort of older adults

People with dementia have an increase in brain inflammation, caused in part by innate and adaptive immune cells. However, it remains unknown whether dementia-associated diseases alter neuro-immune reflex arcs to impact the systemic immune system. We examined peripheral immune cells from a community-based cohort of older adults to test if systemic inflammatory cytokine signatures associated with early stages of cognitive impairment. Human peripheral blood mononuclear cells were cultured with monocyte or T-cell-targeted stimuli, and multiplex assays quantitated cytokines in the conditioned media. Following T-cell-targeted stimulation, cells from women with cognitive impairment produced lower amounts of TH17 cytokines compared with cells from cognitively healthy women, while myeloid-targeted stimuli elicited similar amounts of cytokines from cells of both groups. This TH17 signature correlated with the proportion of circulating CD4+ and CD8+ T cells and plasma glial fibrillary acidic protein and neurofilament light concentrations. These results suggest that decreases in TH17 cytokines could be an early systemic change in women at risk for developing dementia. Amelioration of TH17s cytokines in early cognitive impairment could, in part, explain the compromised ability of older adults to respond to vaccines or defend against infection.

Nanowired delivery of antibodies to tau and neuronal nitric oxide synthase together with cerebrolysin attenuates traumatic brain injury induced exacerbation of brain pathology in Parkinson's disease

Concussive head injury (CHI) is one of the major risk factors for developing Parkinson's disease in later life of military personnel affecting lifetime functional and cognitive disturbances. Till date no suitable therapies are available to attenuate CHI or PD induced brain pathology. Thus, further exploration of novel therapeutic agents are highly warranted using nanomedicine in enhancing the quality of life of veterans or service members of US military. Since PD or CHI induces oxidative stress and perturbs neurotrophic factors regulation associated with phosphorylated tau (p-tau) deposition, a possibility exists that nanodelivery of agents that could enhance neurotrophic factors balance and attenuate oxidative stress could be neuroprotective in nature. In this review, nanowired delivery of cerebrolysin-a balanced composition of several neurotrophic factors and active peptide fragments together with monoclonal antibodies to neuronal nitric oxide synthase (nNOS) with p-tau antibodies was examined in PD following CHI in model experiments. Our results suggest that combined administration of nanowired antibodies to nNOS and p-tau together with cerebrolysin significantly attenuated CHI induced exacerbation of PD brain pathology. This combined treatment also has beneficial effects in CHI or PD alone, not reported earlier.

Mitochondrial-Derived Vesicles: The Good, the Bad, and the Ugly

Mitophagy is crucial for maintaining mitochondrial quality. However, its assessment in vivo is challenging. The endosomal-lysosomal system is a more accessible pathway through which subtypes of extracellular vesicles (EVs), which also contain mitochondrial constituents, are released for disposal. The inclusion of mitochondrial components into EVs occurs in the setting of mild mitochondrial damage and during impairment of lysosomal function. By releasing mitochondrial-derived vesicles (MDVs), cells limit the unload of mitochondrial damage-associated molecular patterns with proinflammatory activity. Both positive and negative effects of EVs on recipient cells have been described. Whether this is due to the production of EVs other than those containing mitochondria, such as MDVs, holding specific biological functions is currently unknown. Evidence on the existence of different MDV subtypes has been produced. However, their characterization is not always pursued, which would be relevant to exploring the dynamics of mitochondrial quality control in health and disease. Furthermore, MDV classification may be instrumental in understanding their biological roles and promoting their implementation as biomarkers in clinical studies.

Mitochondrial-derived vesicles in skeletal muscle remodeling and adaptation

Mitochondrial remodeling is crucial to meet the bioenergetic demand to support muscle contractile activity during daily tasks and muscle regeneration following injury. A set of mitochondrial quality control (MQC) processes, including mitochondrial biogenesis, dynamics, and mitophagy, are in place to maintain a well-functioning mitochondrial network and support muscle regeneration. Alterations in any of these pathways compromises mitochondrial quality and may potentially lead to impaired myogenesis, defective muscle regeneration, and ultimately loss of muscle function. Among MQC processes, mitophagy has gained special attention for its implication in the clearance of dysfunctional mitochondria via crosstalk with the endo-lysosomal system, a major cell degradative route. Along this pathway, additional opportunities for mitochondrial disposal have been identified that may also signal at the systemic level. This communication occurs via inclusion of mitochondrial components within membranous shuttles named mitochondrial-derived vesicles (MDVs). Here, we discuss MDV generation and release as a mitophagy-complementing route for the maintenance of mitochondrial homeostasis in skeletal myocytes. We also illustrate the possible role of muscle-derived MDVs in immune signaling during muscle remodeling and adaptation.

Advancements in Anti-Aging Treatment Development

Aging is a complex and multifactorial process resulting, at least partly, from the generation and accrual of damage in the setting of reduced resilience [...].

Mitochondria-derived vesicles and their potential roles in kidney stone disease

Recent evidence has shown significant roles of mitochondria-derived vesicles (MDVs) in mitochondrial quality control (MQC) system. Under mild stress condition, MDVs are formed to carry the malfunctioned mitochondrial components, such as mitochondrial DNA (mtDNA), peptides, proteins and lipids, to be eliminated to restore normal mitochondrial structure and functions. Under severe oxidative stress condition, mitochondrial dynamics (fission/fusion) and mitophagy are predominantly activated to rescue mitochondrial structure and functions. Additionally, MDVs generation can be also triggered as the major MQC machinery to cope with unhealthy mitochondria when mitophagy is unsuccessful for eliminating the damaged mitochondria or mitochondrial fission/fusion fail to recover the mitochondrial structure and functions. This review summarizes the current knowledge on MDVs and discuss their roles in physiologic and pathophysiologic conditions. In addition, the potential clinical relevance of MDVs in therapeutics and diagnostics of kidney stone disease (KSD) are emphasized.

The Critical Role of Sirt1 in Subarachnoid Hemorrhages: Mechanism and Therapeutic Considerations

The subarachnoid hemorrhage (SAH) is an important cause of death and long-term disability worldwide. As a nicotinamide adenine dinucleotide-dependent deacetylase, silent information regulator 1 (Sirt1) is a multipotent molecule involved in many pathophysiological processes. A growing number of studies have demonstrated that Sirt1 activation may exert positive effects on SAHs by regulating inflammation, oxidative stress, apoptosis, autophagy, and ferroptosis. Thus, Sirt1 agonists may serve as potential therapeutic drugs for SAHs. In this review, we summarized the current state of our knowledge on the relationship between Sirt1 and SAHs and provided an updated overview of the downstream molecules of Sirt1 in SAHs.

Blood-Based Biomarkers for Eosinophilic Esophagitis and Concomitant Atopic Diseases: A Look into the Potential of Extracellular Vesicles

Eosinophilic esophagitis (EoE) is a chronic, Th2-inflammatory disease of the esophagus that can severely affect food intake. Currently, diagnosis and assessing response to treatment of EoE is highly invasive and requires endoscopy with esophageal biopsies. Finding non-invasive and accurate biomarkers is important for improving patient well-being. Unfortunately, EoE is usually accompanied by other atopies, which make it difficult to identify specific biomarkers. Providing an update of circulating EoE biomarkers and concomitant atopies is therefore timely. This review summarizes the current knowledge in EoE blood biomarkers and two of its most common comorbidities, bronchial asthma (BA) and atopic dermatitis (AD), focusing on dysregulated proteins, metabolites, and RNAs. It also revises the current knowledge on extracellular vesicles (EVs) as non-invasive biomarkers for BA and AD, and concludes with the potential use of EVs as biomarkers in EoE.

TSLP and HMGB1: Inflammatory Targets and Potential Biomarkers for Precision Medicine in Asthma and COPD

The airway epithelium, through pattern recognition receptors expressed transmembrane or intracellularly, acts as a first line of defense for the lungs against many environmental triggers. It is involved in the release of alarmin cytokines, which are important mediators of inflammation, with receptors widely expressed in structural cells as well as innate and adaptive immune cells. Knowledge of the role of epithelial cells in orchestrating the immune response and mediating the clearance of invading pathogens and dead/damaged cells to facilitate resolution of inflammation is necessary to understand how, in many chronic lung diseases, there is a persistent inflammatory response that becomes the basis of underlying pathogenesis. This review will focus on the role of pulmonary epithelial cells and of airway epithelial cell alarmins, in particular thymic stromal lymphopoietin (TSLP) and high mobility group box 1 (HMGB1), as key mediators in driving the inflammation of chronic lung diseases, such as asthma and chronic obstructive pulmonary disease (COPD), evaluating the similarities and differences. Moreover, emerging concepts regarding the therapeutic role of molecules that act on airway epithelial cell alarmins will be explored for a precision medicine approach in the context of pulmonary diseases, thus allowing the use of these molecules as possible predictive biomarkers of clinical and biological response.

Tumor-Promoting Activity and Proteomic Profiling of Cisplatin/Oxaliplatin-Derived DAMPs in Cholangiocarcinoma Cells

Damage-associated molecular patterns (DAMPs) are well recognized as the molecular signature of immunogenic cell death (ICD). The efficacy of drug-induced ICD function may be impacted by the precise ratio between immunostimulatory and immunoinhibitory DAMPs. Tumor-derived DAMPs can activate tumor-expressed TLRs for the promotion of tumor cell motility, invasion, metastatic spread and resistance to chemotherapeutic treatment. Herein, drug-induced DAMPs’ expression and their role in tumor progression are utilized as one crucial point of evaluation regarding chemotherapeutic treatment efficacy in our study. Cisplatin and oxaliplatin, the conventional anticancer chemotherapy drugs, are emphasized as a cause of well-known DAMPs’ release from cholangiocarcinoma (CCA) cells (e.g., HSP family, S100, CRT and HMGB1), whereby they trigger Akt, ERK and Cyclin-D1 to promote tumor activities. These findings strengthen the evidence that DAMPs are not only involved in immunomodulation but also in tumor promotion. Therefore, DAMP molecules should be considered as either targets of cancer treatment or biomarkers to evaluate treatment efficacy and tumor recurrence.

Mitochondrial-derived vesicles: Gatekeepers of mitochondrial response to oxidative stress

Mitochondrial quality control (MQC) mechanisms are a series of adaptive responses that ensure the relative stability of mitochondrial morphology, quantity, and quality to preserve cellular survival and function. While MQC mechanisms range from mitochondrial biogenesis and fusion/fission to mitophagy, mitochondrial-derived vesicles (MDVs) may represent an essential component of MQC. MDVs precede mitochondrial autophagy and serve as the first line of defense against oxidative stress by selectively transferring damaged mitochondrial substances to the lysosome for degradation. In fact, the function of MDVs is dependent on the cargo, the shuttle route, and the ultimate destination. Abnormal MDVs disrupt metabolite clearance and the immune response, predisposing to pathological conditions, including neurodegeneration, cardiovascular diseases, and cancers. Therefore, MDV regulation may be a potential therapeutic for the therapy of these diseases. In this review, we highlight recent advances in the study of MDVs and their misregulation in various diseases from the perspectives of formation, cargo selection, regulation, and transportation.

Mitochondrial DNA Is a Vital Driving Force in Ischemia-Reperfusion Injury in Cardiovascular Diseases

According to the latest Global Burden of Disease Study, cardiovascular disease (CVD) is the leading cause of death, and ischemic heart disease and stroke are the cause of death in approximately half of CVD patients. In CVD, mitochondrial dysfunction following ischemia-reperfusion (I/R) injury results in heart failure. The proper functioning of oxidative phosphorylation (OXPHOS) and the mitochondrial life cycle in cardiac mitochondria are closely related to mitochondrial DNA (mtDNA). Following myocardial I/R injury, mitochondria activate multiple repair and clearance mechanisms to repair damaged mtDNA. When these repair mechanisms are insufficient to restore the structure and function of mtDNA, irreversible mtDNA damage occurs, leading to mtDNA mutations. Since mtDNA mutations aggravate OXPHOS dysfunction and affect mitophagy, mtDNA mutation accumulation leads to leakage of mtDNA and proteins outside the mitochondria, inducing an innate immune response, aggravating cardiovascular injury, and leading to the need for external interventions to stop or slow the disease course. On the other hand, mtDNA released into the circulation after cardiac injury can serve as a biomarker for CVD diagnosis and prognosis. This article reviews the pathogenic basis and related research findings of mtDNA oxidative damage and mtDNA leak-triggered innate immune response associated with I/R injury in CVD and summarizes therapeutic options that target mtDNA.

Action Mechanisms of Small Extracellular Vesicles in Inflammaging

The accumulation process of proinflammatory components in the body due to aging influences intercellular communication and is known as inflammaging. This biological mechanism relates the development of inflammation to the aging process. Recently, it has been reported that small extracellular vesicles (sEVs) are mediators in the transmission of paracrine senescence involved in inflammatory aging. For this reason, their components, as well as mechanisms of action of sEVs, are relevant to develop a new therapy called senodrugs (senolytics and senomorphic) that regulates the intercellular communication of inflammaging. In this review, we include the most recent and relevant studies on the role of sEVs in the inflammatory aging process and in age-related diseases such as cancer and type 2 diabetes.

High Mobility Group Box 1: Biological Functions and Relevance in Oxidative Stress Related Chronic Diseases

In the early 1970s, a group of non-histone nuclear proteins with high electrophoretic mobility was discovered and named high-mobility group (HMG) proteins. High-mobility group box 1 (HMGB1) is the most studied HMG protein that detects and coordinates cellular stress response. The biological function of HMGB1 depends on its subcellular localization and expression. It plays a critical role in the nucleus and cytoplasm as DNA chaperone, chromosome gatekeeper, autophagy maintainer, and protector from apoptotic cell death. HMGB1 also functions as an extracellular alarmin acting as a damage-associated molecular pattern molecule (DAMP). Recent findings describe HMGB1 as a sophisticated signal of danger, with a pleiotropic function, which is useful as a clinical biomarker for several disorders. HMGB1 has emerged as a mediator in acute and chronic inflammation. Furthermore, HMGB1 targeting can induce beneficial effects on oxidative stress related diseases. This review focus on HMGB1 redox status, localization, mechanisms of release, binding with receptors, and its activities in different oxidative stress-related chronic diseases. Since a growing number of reports show the key role of HMGB1 in socially relevant pathological conditions, to our knowledge, for the first time, here we analyze the scientific literature, evaluating the number of publications focusing on HMGB1 in humans and animal models, per year, from 2006 to 2021 and the number of records published, yearly, per disease and category (studies on humans and animal models).

Combination Therapy of Stem Cell-derived Exosomes and Biomaterials in the Wound Healing

Wound healing is a serious obstacle due to the complexity of evaluation and management. While novel approaches to promoting chronic wound healing are of critical interest at the moment, several studies have demonstrated that combination therapy is critical for the treatment of a variety of diseases, particularly chronic wounds. Among the various approaches that have been proposed for wound care, regenerative medicine-based methods have garnered the most attention. As is well known, regenerative medicine's three primary tools are gene/cell therapy, biomaterials, and tissue engineering. Multifunctional biomaterials composed of synthetic and natural components are highly advantageous for exosome carriers, which utilizing them is an exciting wound healing method. Recently, stem cell-secreted exosomes and certain biomaterials have been identified as critical components of the wound healing process, and their combination therapy appears to produce significant results. This paper presents a review of literature and perspectives on the use of stem cell-derived exosomes and biomaterials in wound healing, particularly chronic wounds, and discusses the possibility of future clinical applications.

Mitochondrial Dysfunction, Protein Misfolding and Neuroinflammation in Parkinson's Disease: Roads to Biomarker Discovery

Parkinson’s Disease (PD) is a highly prevalent neurodegenerative disease among older adults. PD neuropathology is marked by the progressive loss of the dopaminergic neurons of the substantia nigra pars compacta and the widespread accumulation of misfolded intracellular α-synuclein (α-syn). Genetic mutations and post-translational modifications, such as α-syn phosphorylation, have been identified among the multiple factors supporting α-syn accrual during PD. A decline in the clearance capacity of the ubiquitin-proteasome and the autophagy-lysosomal systems, together with mitochondrial dysfunction, have been indicated as major pathophysiological mechanisms of PD neurodegeneration. The accrual of misfolded α-syn aggregates into soluble oligomers, and the generation of insoluble fibrils composing the core of intraneuronal Lewy bodies and Lewy neurites observed during PD neurodegeneration, are ignited by the overproduction of reactive oxygen species (ROS). The ROS activate the α-syn aggregation cascade and, together with the Lewy bodies, promote neurodegeneration. However, the molecular pathways underlying the dynamic evolution of PD remain undeciphered. These gaps in knowledge, together with the clinical heterogeneity of PD, have hampered the identification of the biomarkers that may be used to assist in diagnosis, treatment monitoring, and prognostication. Herein, we illustrate the main pathways involved in PD pathogenesis and discuss their possible exploitation for biomarker discovery.

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.

Mitophagy: At the heart of mitochondrial quality control in cardiac aging and frailty

Cardiovascular disease is highly prevalent among older adults and poses a huge burden on morbidity, disability, and mortality. The age-related increased vulnerability of the cardiovascular system towards stressors is a pathophysiological trait of cardiovascular disease. This has been associated with a progressive deterioration of blood vessels and decline in heart function during aging. Cardiomyocytes rely mostly on oxidative metabolism for deploying their activities and mitochondrial metabolism is crucial to this purpose. Dysmorphic, inefficient, and oxidant-producing mitochondria have been identified in aged cardiomyocytes in association with cardiac structural and functional alterations. These aberrant organelles are thought to arise from inefficient mitochondrial quality control, which has therefore been place in the spotlight as a relevant mechanism of cardiac aging. As a result of alterations in mitochondrial quality control and redox dyshomeostasis, mitochondrial damage accumulates and contributes to cardiac frailty. Herein, we discuss the contribution of defective mitochondrial quality control pathways to cardiac frailty. Emerging findings pointing towards the exploitation of these pathways as therapeutic targets against cardiac aging and cardiovascular disease will also be illustrated.

Extracellular Vesicles and Pancreatic Cancer: Insights on the Roles of miRNA, lncRNA, and Protein Cargos in Cancer Progression

Pancreatic cancer (PC) is among the most devastating digestive tract cancers worldwide. This cancer is characterized by poor diagnostic detection, lack of therapy, and difficulty in predicting tumorigenesis progression. Although mutations of key oncogenes and oncosuppressor involved in tumor growth and in immunosurveillance escape are known, the underlying mechanisms that orchestrate PC initiation and progression are poorly understood or still under debate. In recent years, the attention of many researchers has been concentrated on the role of extracellular vesicles and of a particular subset of extracellular vesicles, known as exosomes. Literature data report that these nanovesicles are able to deliver their cargos to recipient cells playing key roles in the pathogenesis and progression of many pancreatic precancerous conditions. In this review, we have summarized and discussed principal cargos of extracellular vesicles characterized in PC, such as miRNAs, lncRNAs, and several proteins, to offer a systematic overview of their function in PC progression. The study of extracellular vesicles is allowing to understand that investigation of their secretion and analysis of their content might represent a new and potential diagnostic and prognostic tools for PC.

The effect of extracellular vesicles on the regulation of mitochondria under hypoxia

Mitochondria are indispensable organelles for maintaining cell energy metabolism, and also are necessary to retain cell biological function by transmitting information as signal organelles. Hypoxia, one of the important cellular stresses, can directly regulates mitochondrial metabolites and mitochondrial reactive oxygen species (mROS), which affects the nuclear gene expression through mitochondrial retrograde signal pathways, and also promotes the delivery of signal components into cytoplasm, causing cellular injury. In addition, mitochondria can also trigger adaptive mechanisms to maintain mitochondrial function in response to hypoxia. Extracellular vesicles (EVs), as a medium of information transmission between cells, can change the biological effects of receptor cells by the release of cargo, including nucleic acids, proteins, lipids, mitochondria, and their compositions. The secretion of EVs increases in cells under hypoxia, which indirectly changes the mitochondrial function through the uptake of contents by the receptor cells. In this review, we focus on the mitochondrial regulation indirectly through EVs under hypoxia, and the possible mechanisms that EVs cause the changes in mitochondrial function. Finally, we discuss the significance of this EV-mitochondria axis in hypoxic diseases.