Sheng-Jiang powder ameliorates NAFLD via regulating intestinal microbiota in mice.

Background: Intestinal microbiota have been demonstrated to be involved in the development of NAFLD, while the relationship between the severity of NAFLD and intestinal microbiota is still not fully elucidated. Sheng-Jiang Powder (SJP) showed exact efficacy in treating SFL and great potential in regulating intestinal microbiota, but the effects need to be further addressed in NASH and liver fibrosis. Objectives: To investigate the differences in intestinal microbiota of NAFLD with different severity and the effect of SJP on liver damage and intestinal microbiota. Design: NAFLD mice models with different severity were induced by high-fat diet (HFD) or choline-deficient, L-amino acid-defined high-fat diet (CDAHFD) feeding and then treated with SJP/normal saline. Methods: Biochemical blood tests, H&E/Masson/Oil Red O/IHC staining, Western blot, and 16SrDNA sequencing were performed to explore intestinal microbiota alteration in different NAFLD models and the effect of SJP on liver damage and intestinal microbiota. Results: Intestinal microbiota alteration was detected in all NAFLD mice. SJP induced increased expression of Pparγ and alleviated liver lipid deposition in all NAFLD mice. Microbiome analysis revealed obvious changes in intestinal microbiota composition, while SJP significantly elevated the relative abundance of Roseburia and Akkermansia, which were demonstrated to be beneficial for improving inflammation and intestinal barrier function. Conclusion: Our results demonstrated that SJP was effective in improving lipid metabolism in NAFLD mice, especially in mice with SFL. The potential mechanism may be associated with the regulation of intestinal microbiota.

Urolithin A's Role in Alleviating Severe Acute Pancreatitis via Endoplasmic Reticulum-Mitochondrial Calcium Channel Modulation.

Severe acute pancreatitis (SAP), characterized by pancreatic acinar cell death, currently lacks effective targeted therapies. Ellagic acid (EA), rich in pomegranate, shows promising anti-inflammatory and antioxidant effects in SAP treatment. However, the roles of other forms of EA, such as plant extracellular vesicles (EVs) extracted from pomegranate, and Urolithin A (UA), converted from EA through gut microbiota metabolism in vivo, have not been definitively elucidated. Our research aimed to compare the effects of pomegranate-derived EVs (P-EVs) and UA in the treatment of SAP to screen an effective formulation and to explore its mechanisms in protecting acinar cells in SAP. By comparing the protective effects of P-EVs and UA on injured acinar cells, UA showed superior therapeutic effects than P-EVs. Subsequently, we further discussed the mechanism of UA in alleviating SAP inflammation. In vivo animal experiments found that UA could not only improve the inflammatory environment of pancreatic tissue and peripheral blood circulation in SAP mice but also revealed that the mechanism of UA in improving SAP might be related to mitochondria and endoplasmic reticulum (ER) through the results including pancreatic tissue transcriptomics and transmission electron microscopy. Further research found that UA could regulate ER-mitochondrial calcium channels and reduce pancreatic tissue necroptosis. In vitro experiments of mouse pancreatic organoids and acinar cells also confirmed that UA could improve pancreatic inflammation by regulating the ER-mitochondrial calcium channel and necroptosis pathway proteins. This study not only explored the therapeutic effect of plant EVs on SAP but also revealed that UA could alleviate SAP by regulating ER-mitochondrial calcium channel and reducing acinar cell necroptosis, providing insights into the pathogenesis and potential treatment of SAP.

ALS-linked C9orf72-SMCR8 complex is a negative regulator of primary ciliogenesis.

Massive GGGGCC (G4C2) repeat expansion in C9orf72 and the resulting loss of C9orf72 function are the key features of ~50% of inherited amyotrophic lateral sclerosis and frontotemporal dementia cases. However, the biological function of C9orf72 remains unclear. We previously found that C9orf72 can form a stable GTPase activating protein (GAP) complex with SMCR8 (Smith-Magenis chromosome region 8). Herein, we report that the C9orf72-SMCR8 complex is a major negative regulator of primary ciliogenesis, abnormalities in which lead to ciliopathies. Mechanistically, the C9orf72-SMCR8 complex suppresses the primary cilium as a RAB8A GAP. Moreover, based on biochemical analysis, we found that C9orf72 is the RAB8A binding subunit and that SMCR8 is the GAP subunit in the complex. We further found that the C9orf72-SMCR8 complex suppressed the primary cilium in multiple tissues from mice, including but not limited to the brain, kidney, and spleen. Importantly, cells with C9orf72 or SMCR8 knocked out were more sensitive to hedgehog signaling. These results reveal the unexpected impact of C9orf72 on primary ciliogenesis and elucidate the pathogenesis of diseases caused by the loss of C9orf72 function.

Urolithin A protects severe acute pancreatitis-associated acute cardiac injury by regulating mitochondrial fatty acid oxidative metabolism in cardiomyocytes.

Severe acute pancreatitis (SAP) often develops into acute cardiac injury (ACI), contributing to the high mortality of SAP. Urolithin A (UA; 3,8-dihydroxy-6H-dibenzopyran-6-one), a natural polyphenolic compound, has been extensively studied and shown to possess significant anti-inflammatory effects. Nevertheless, the specific effects of UA in SAP-associated acute cardiac injury (SACI) have not been definitively elucidated. Here, we investigated the therapeutic role and mechanisms of UA in SACI using transcriptomics and untargeted metabolomics analyses in a mouse model of SACI and in vitro studies. SACI resulted in severely damaged pancreatic and cardiac tissues with myocardial mitochondrial dysfunction and mitochondrial metabolism disorders. UA significantly reduced the levels of lipase, amylase and inflammatory factors, attenuated pathological damage to pancreatic and cardiac tissues, and reduced myocardial cell apoptosis and oxidative stress in SACI. Moreover, UA increased mitochondrial membrane potential and adenosine triphosphate production and restored mitochondrial metabolism, but the efficacy of UA was weakened by the inhibition of CPT1. Therefore, UA can attenuate cardiac mitochondrial dysfunction and reduce myocardial apoptosis by restoring the balance of mitochondrial fatty acid oxidation metabolism. CPT1 may be a potential target. This study has substantial implications for advancing our understanding of the pathogenesis and drug development of SACI.

Gut microbiota interacts with inflammatory responses in acute pancreatitis.

Acute pancreatitis (AP) is one of the most common acute abdominal conditions, and its incidence has been increasing for years. Approximately 15-20% of patients develop severe AP (SAP), which is complicated by critical inflammatory injury and intestinal dysfunction. AP-associated inflammation can lead to the gut barrier and function damage, causing dysbacteriosis and facilitating intestinal microbiota migration. Pancreatic exocrine deficiency and decreased levels of antimicrobial peptides in AP can also lead to abnormal growth of intestinal bacteria. Meanwhile, intestinal microbiota migration influences the pancreatic microenvironment and affects the severity of AP, which, in turn, exacerbates the systemic inflammatory response. Thus, the interaction between the gut microbiota (GM) and the inflammatory response may be a key pathogenic feature of SAP. Treating either of these factors or breaking their interaction may offer some benefits for SAP treatment. In this review, we discuss the mechanisms of interaction of the GM and inflammation in AP and factors that can deteriorate or even cure both, including some traditional Chinese medicine treatments, to provide new methods for studying AP pathogenesis and developing therapies.

MitoEVs: A new player in multiple disease pathology and treatment.

Mitochondrial damage plays vital roles in the pathology of many diseases, such as cancers, neurodegenerative diseases, aging, metabolic diseases and many types of organ injury. However, the regulatory mechanism of mitochondrial functions among different cells or organs in vivo is still unclear, and efficient therapies for attenuating mitochondrial damage are urgently needed. Extracellular vesicles (EVs) are cell-derived nanovesicles that can deliver bioactive cargoes among cells or organs. Interestingly, recent evidence shows that diverse mitochondrial contents are enriched in certain EV subpopulations, and such mitoEVs can deliver mitochondrial components to affect the functions of recipient cells under different conditions, which has emerged as a hot topic in this field. However, the overview and many essential questions with respect to this event remain elusive. In this review, we provide a global view of mitoEVs biology and mainly focus on the detailed sorting mechanisms, functional mitochondrial contents, and diverse biological effects of mitoEVs. We also discuss the pathogenic or therapeutic roles of mitoEVs in different diseases and highlight their potential as disease biomarkers or therapies in clinical translation. This review will provide insights into the pathology and drug development for various mitochondrial injury-related diseases.

Extracellular Vesicle ITGAM and ITGB2 Mediate Severe Acute Pancreatitis-Related Acute Lung Injury.

Integrins expressed on extracellular vesicles (EVs) secreted by various cancers are reported to mediate the organotropism of these EVs. Our previous experiment found that pancreatic tissue of mice with severe cases of acute pancreatitis (SAP) overexpresses several integrins and that serum EVs of these mice (SAP-EVs) can mediate acute lung injury (ALI). It is unclear if SAP-EV express integrins that can promote their accumulation in the lung to promote ALI. Here, we report that SAP-EV overexpress several integrins and that preincubation of SAP-EV with the integrin antagonist peptide HYD-1 markedly attenuates their pulmonary inflammation and disrupt the pulmonary microvascular endothelial cell (PMVEC) barrier. Further, we report that injecting SAP mice with EVs engineered to overexpress two of these integrins (ITGAM and ITGB2) can attenuate the pulmonary accumulation of pancreas-derived EVs and similarly decrease pulmonary inflammation and disruption of the endothelial cell barrier. Based on these findings, we propose that pancreatic EVs can mediate ALI in SAP patients and that this injury response could be attenuated by administering EVs that overexpress ITGAM and/or ITGB2, which is worthy of further study due to the lack of effective therapies for SAP-induced ALI.

Histidine triad nucleotide-binding protein 2: From basic science to clinical implications.

Histidine triad nucleotide-binding protein 2 (HINT2) is a dimeric protein that belongs to the histidine triad protein superfamily, predominantly expressed in the liver, pancreas, and adrenal gland, and localised to the mitochondrion. HINT2 binds nucleotides and catalyses the hydrolysis of nucleotidyl substrates. Moreover, HINT2 has been identified as a key regulator of multiple biological processes, including mitochondria-dependent apoptosis, mitochondrial protein acetylation, and steroidogenesis. Genetic manipulation has provided new insights into the physiological roles of HINT2 in several processes, such as inhibition of cancer progression, regulation of hepatic lipid metabolism, and protective effects on the cardiovascular system. The current review outlines the background and functions of HINT2. In addition, it summarises research progress on the correlation between HINT2 and human malignancies, hepatic metabolic diseases, and cardiovascular diseases, with an attempt to provide new research directions emerging in this field and to unveil the therapeutic value of HINT2 as a target in the combat of human diseases.

Extracellular vesicles in the pathogenesis and treatment of acute lung injury.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common life-threatening lung diseases associated with acute and severe inflammation. Both have high mortality rates, and despite decades of research on clinical ALI/ARDS, there are no effective therapeutic strategies. Disruption of alveolar-capillary barrier integrity or activation of inflammatory responses leads to lung inflammation and injury. Recently, studies on the role of extracellular vesicles (EVs) in regulating normal and pathophysiologic cell activities, including inflammation and injury responses, have attracted attention. Injured and dysfunctional cells often secrete EVs into serum or bronchoalveolar lavage fluid with altered cargoes, which can be used to diagnose and predict the development of ALI/ARDS. EVs secreted by mesenchymal stem cells can also attenuate inflammatory reactions associated with cell dysfunction and injury to preserve or restore cell function, and thereby promote cell proliferation and tissue regeneration. This review focuses on the roles of EVs in the pathogenesis of pulmonary inflammation, particularly ALI/ARDS.

Emodin attenuates severe acute pancreatitis-associated acute lung injury by suppressing pancreatic exosome-mediated alveolar macrophage activation.

Severe acute pancreatitis-associated acute lung injury (SAP-ALI) is a serious disease associated with high mortality. Emodin has been applied to alleviate SAP-ALI; however, the mechanism remains unclear. We report that the therapeutic role of emodin in attenuating SAP-ALI is partly dependent on an exosomal mechanism. SAP rats had increased levels of plasma exosomes with altered protein contents compared to the sham rats. These infused plasma exosomes tended to accumulate in the lungs and promoted the hyper-activation of alveolar macrophages and inflammatory damage. Conversely, emodin treatment decreased the plasma/pancreatic exosome levels in the SAP rats. Emodin-primed exosomes showed less pro-inflammatory effects in alveolar macrophages and lung tissues than SAP exosomes. In detail, emodin-primed exosomes suppressed the NF-κB pathway to reduce the activation of alveolar macrophage and ameliorate lung inflammation by regulating PPARγ pathway, while these effects were amplified/abolished by PPARγ agonist/antagonist. Blockage of pancreatic acinar cell exosome biogenesis also exhibited suppression of alveolar macrophage activation and reduction of lung inflammation. This study suggests a vital role of exosomes in participating inflammation-associated organ-injury, and indicates emodin can attenuate SAP-ALI by reducing the pancreatic exosome-mediated alveolar macrophage activation.

Molecular mechanisms and therapeutic target of NETosis in diseases.

Evidence shows that neutrophils can protect the host against pathogens in multiple ways, including the formation and release of neutrophil extracellular traps (NETs). NETs are web-like structures composed of fibers, DNA, histones, and various neutrophil granule proteins. NETs can capture and kill pathogens, including bacteria, viruses, fungi, and protozoa. The process of NET formation is called NETosis. According to whether they depend on nicotinamide adenine dinucleotide phosphate (NADPH), NETosis can be divided into two categories: "suicidal" NETosis and "vital" NETosis. However, NET components, including neutrophil elastase, myeloperoxidase, and cell-free DNA, cause a proinflammatory response and potentially severe diseases. Compelling evidence indicates a link between NETs and the pathogenesis of a number of diseases, including sepsis, systemic lupus erythematosus, rheumatoid arthritis, small-vessel vasculitis, inflammatory bowel disease, cancer, COVID-19, and others. Therefore, targeting the process and products of NETosis is critical for treating diseases linked with NETosis. Researchers have discovered that several NET inhibitors, such as toll-like receptor inhibitors and reactive oxygen species scavengers, can prevent uncontrolled NET development. This review summarizes the mechanism of NETosis, the receptors associated with NETosis, the pathology of NETosis-induced diseases, and NETosis-targeted therapy.

Dao-Chi Powder Ameliorates Pancreatitis-Induced Intestinal and Cardiac Injuries via Regulating the Nrf2-HO-1-HMGB1 Signaling Pathway in Rats.

Dao-Chi powder (DCP) has been widely used in the treatment of inflammatory diseases in the clinical practice of traditional Chinese medicine, but has not been used in acute pancreatitis (AP). This study aimed to evaluate the effect of DCP on severe AP (SAP) and SAP-associated intestinal and cardiac injuries. To this end, an SAP animal model was established by retrograde injection of 3.5% taurocholic acid sodium salt into the biliopancreatic ducts of rats. Intragastric DCP (9.6 g/kg.BW) was administered 12 h after modeling. The pancreas, duodenum, colon, heart and blood samples were collected 36 h after the operation for histological and biochemical detection. The tissue distributions of the DCP components were determined and compared between the sham and the SAP groups. Moreover, molecular docking analysis was employed to investigate the interactions between the potential active components of DCP and its targets (Nrf2, HO-1, and HMGB1). Consequently, DCP treatment decreased the serum levels of amylase and the markers of gastrointestinal and cardiac injury, further alleviating the pathological damage in the pancreas, duodenum, colon, and heart of rats with SAP. Mechanistically, DCP rebalanced the pro-/anti-inflammatory cytokines and inhibited MPO activity and MDA levels in these tissues. Furthermore, Western blot and RT-PCR results showed that DCP intervention enhanced the expression of Nrf2 and HO-1 in the duodenum and colon of rats with SAP, while inhibiting the expression of HMGB1 in the duodenum and heart. HPLC-MS/MS analysis revealed that SAP promoted the distribution of ajugol and oleanolic acid to the duodenum, whereas it inhibited the distribution of liquiritigenin to the heart and ajugol to the colon. Molecular docking analysis confirmed that the six screened components of DCP had relatively good binding affinity with Nrf2, HO-1, and HMGB1. Among these, oleanolic acid had the highest affinity for HO-1. Altogether, DCP could alleviated SAP-induced intestinal and cardiac injuries via inhibiting the inflammatory responses and oxidative stress partially through regulating the Nrf2/HO-1/HMGB1 signaling pathway, thereby providing additional supportive evidence for the clinical treatment of SAP.

Peritoneal M2 macrophage-derived extracellular vesicles as natural multitarget nanotherapeutics to attenuate cytokine storms after severe infections.

Cytokine storms are a primary cause of multiple organ damage and death after severe infections, such as SARS-CoV-2. However, current single cytokine-targeted strategies display limited therapeutic efficacy. Here, we report that peritoneal M2 macrophage-derived extracellular vesicles (M2-EVs) are multitarget nanotherapeutics that can be used to resolve cytokine storms. In detail, primary peritoneal M2 macrophages exhibited superior anti-inflammatory potential than immobilized cell lines. Systemically administered M2-EVs entered major organs and were taken up by phagocytes (e.g., macrophages). M2-EV treatment effectively reduced excessive cytokine (e.g., TNF-α and IL-6) release in vitro and in vivo, thereby attenuating oxidative stress and multiple organ (lung, liver, spleen and kidney) damage in endotoxin-induced cytokine storms. Moreover, M2-EVs simultaneously inhibited multiple key proinflammatory pathways (e.g., NF-κB, JAK-STAT and p38 MAPK) by regulating complex miRNA-gene and gene-gene networks, and this effect was collectively mediated by many functional cargos (miRNAs and proteins) in EVs. In addition to the direct anti-inflammatory role, human peritoneal M2-EVs expressed angiotensin-converting enzyme 2 (ACE2), a receptor of SARS-CoV-2 spike protein, and thus could serve as nanodecoys to prevent SARS-CoV-2 pseudovirus infection in vitro. As cell-derived nanomaterials, the therapeutic index of M2-EVs can be further improved by genetic/chemical modification or loading with specific drugs. This study highlights that peritoneal M2-EVs are promising multifunctional nanotherapeutics to attenuate infectious disease-related cytokine storms.

Emodin Ameliorates Acute Pancreatitis-Associated Lung Injury Through Inhibiting the Alveolar Macrophages Pyroptosis.

Objective: To investigate the protective effect of emodin in acute pancreatitis (AP)-associated lung injury and the underlying mechanisms. Methods: NaT-AP model in rats was constructed using 3.5% sodium taurocholate, and CER+LPS-AP model in mice was constructed using caerulein combined with Lipopolysaccharide. Animals were divided randomly into four groups: sham, AP, Ac-YVAD-CMK (caspase-1 specific inhibitor, AYC), and emodin groups. AP-associated lung injury was assessed with H&E staining, inflammatory cytokine levels, and myeloperoxidase activity. Alveolar macrophages (AMs) pyroptosis was evaluated by flow cytometry. In bronchoalveolar lavage fluid, the levels of lactate dehydrogenase and inflammatory cytokines were measured by enzyme-linked immunosorbent assay. Pyroptosis-related protein expressions were detected by Western Blot. Results: Emodin, similar to the positive control AYC, significantly alleviated pancreas and lung damage in rats and mice. Additionally, emodin mitigated the pyroptotic process of AMs by decreasing the level of inflammatory cytokines and lactate dehydrogenase. More importantly, the protein expressions of NLRP3, ASC, Caspase1 p10, GSDMD, and GSDMD-NT in AMs were significantly downregulated after emodin intervention. Conclusion: Emodin has a therapeutic effect on AP-associated lung injury, which may result from the inhibition of NLRP3/Caspase1/GSDMD-mediated AMs pyroptosis signaling pathways.

Zengye Decoction Attenuated Severe Acute Pancreatitis Complicated with Acute Kidney Injury by Modulating the Gut Microbiome and Serum Amino Acid Metabolome.

Objective: To explore the effect and underlying mechanism of Zengye decoction (ZYD), a traditional formula from China, on the severe acute pancreatitis (SAP) rat model with acute kidney injury (AKI). Methods: The SAP-AKI model was induced by 3.5% sodium taurocholate. Rats were treated with normal saline or ZYD twice and sacrificed at 36 h after modeling. Amylase, lipase, creatinine, blood urea nitrogen, kidney injury molecule 1(KIM-1), and multiple organs' pathological examinations were used to assess the protective effect of ZYD. Gut microbiome detected by 16S rRNA sequencing analysis and serum amino acid metabolome analyzed by liquid chromatography-mass spectrometry explained the underlying mechanism. The Spearman correlation analysis presented the relationship between microflora and metabolites. Results: ZYD significantly decreased KIM-1(P < 0.05) and the pathological score of the pancreas (P < 0.05), colon (P < 0.05), and kidney (P < 0.05). Meanwhile, ZYD shifted the overall gut microbial structure (ß-diversity, ANOSIM R = 0.14, P=0.025) and altered the microbial compositions. Notably, ZYD reduced the potentially pathogenic bacteria-Bacteroidetes, Clostridiales vadin BB60 group, and uncultured_Clostridiales_bacterium, but promoted the short-chain fatty acid (SCFA) producers-Erysipelotrichaceae, Bifidobacterium, Lactobacillus, and Moryella (all P < 0.05). Moreover, principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and hierarchical clustering analysis (HCA) presented a remarkable change in amino acid metabolome after SAP-AKI induction and an apparent regulation by ZYD treatment (R2Y 0.878, P=0.01; Q2 0.531, P=0.01). Spearman's correlation analysis suggested that gut bacteria likely influenced serum metabolites levels (absolute r > 0.4 and FDR P < 0.02). Conclusions: ZYD attenuated SAP-AKI by modulating the gut microbiome and serum amino acid metabolome, which may be a promising adjuvant treatment.

Epigenetic changes in inflammatory genes and the protective effect of cooked rhubarb on pancreatic tissue of rats with chronic alcohol exposure.

Chronic alcohol consumption, which is observed worldwide, can damage pancreatic tissue and promote pancreatitis. Rhubarb is a widely used traditional Chinese herbal medicine for treating pancreatitis in China. However, few pharmacological studies have investigated its epigenetic regulation. In this study, we investigated whether chronic exposure to alcohol can alter inflammatory gene expression and the epigenetic regulation effect of cooked rhubarb in the pancreatic tissue of rats. First, changes in inflammatory cytokine DNA methylation (IL-10, IL-1α, TNF-α, NF-κB and TGF-ß) were detected in pancreatic tissue of Sprague-Dawley rats with varying alcohol exposure times (4, 6, 8, or 12 weeks), and then with varying doses of cooked rhubarb treatment (3, 6, or 12 g/day). DNA methylation levels, related RNA concentrations and protein expression of specific inflammatory cytokines, and histopathological score were analysed in pancreatic tissue of Sprague-Dawley rats. The results showed that chronic alcohol exposure (8 weeks) reduced the level of IL-1α DNA methylation and increased its protein expression in acinar cells (P < 0.05). In the acinar cells, the level of IL-10 DNA methylation increased, resulting in a reduction of protein expression (P < 0.05). Simultaneously, chronic alcohol exposure increased the pathological damage to the pancreas (P < 0.05). Finally, cooked rhubarb treatment (3 g/kg/day) effectively alleviated these changes in pancreatic tissue from chronic alcohol exposure (P < 0.05). These results indicate that chronic exposure to alcohol leads to changes in DNA methylation and protein expression of inflammatory genes, and cooked rhubarb may have a protective effect on the pancreatic tissue of rats.

Role of neutrophil extracellular traps in inflammatory evolution in severe acute pancreatitis.

ABSTRACT: Severe acute pancreatitis (SAP) is a life-threatening acute abdominal disease with two peaks of death: the first in the early stage, characterized by systemic inflammatory response-associated organ failure; and the second in the late stage, characterized by infectious complications. Neutrophils are the main immune cells participating in the whole process of SAP. In addition to the traditional recognition of neutrophils as the origination of chemokine and cytokine cascades or phagocytosis and degranulation of pathogens, neutrophil extracellular traps (NETs) also play an important roles in inflammatory reactions. We reviewed the role of NETs in the occurrence and development of SAP and its fatal complications, including multiple organs injury, infected pancreatic necrosis, and thrombosis. This review provides novel insights into the involvement of NETs throughout the entire process of SAP, showing that targeting NETs might be a promising strategy in SAP treatment. However, precision therapeutic options targeting NETs in different situations require further investigation.

Extracellular vesicle activities regulating macrophage- and tissue-mediated injury and repair responses.

Macrophages are typically identified as classically activated (M1) macrophages and alternatively activated (M2) macrophages, which respectively exhibit pro- and anti-inflammatory phenotypes, and the balance between these two subtypes plays a critical role in the regulation of tissue inflammation, injury, and repair processes. Recent studies indicate that tissue cells and macrophages interact via the release of small extracellular vesicles (EVs) in processes where EVs released by stressed tissue cells can promote the activation and polarization of adjacent macrophages which can in turn release EVs and factors that can promote cell stress and tissue inflammation and injury, and vice versa. This review discusses the roles of such EVs in regulating such interactions to influence tissue inflammation and injury in a number of acute and chronic inflammatory disease conditions, and the potential applications, advantage and concerns for using EV-based therapeutic approaches to treat such conditions, including their potential role of drug carriers for the treatment of infectious diseases.

Dye-free spectrophotometric measurement of nucleic acid-to-protein ratio for cell-selective extracellular vesicle discrimination.

Extracellular vesicles (EVs) can represent a novel source of disease biomarkers, and are under intensive study for their clinical potential. Most EV-based cancer diagnostic studies have focused on establishing EV assays that detect increased expression of a single cancer-associated marker or marker signatures based on multiplex detection of these biomarkers. EV biomarker readouts can be obscured by high background signal leading to false positives, and may markedly differ between analyses due to variation in sample purity during EV isolation. This can obstruct the comparisons among studies and lead to conflicting conclusions. This work reports that the nucleic acid to protein UV absorption ratio of an EV is a cell-specific EV characteristic. This EV collective attribute can be measured at low-cost to discriminate EVs derived from malignant and non-malignant cells rather than employing single markers that may be cancer- or subtype-specific. Our work also highlighted the application for accessing purity in EV preparations irrelevant to EV yield. It can be employed to distinguish from patients with and without malignant disease upon analysis of EVs isolated from their serum samples.