Exosome-derived CIRP: An amplifier of inflammatory diseases

The Increasing Diagnostic Role of Exosomes in Inflammatory Diseases to Leverage the Therapeutic Biomarkers

Inflammatory diseases provide substantial worldwide concerns, affecting millions of people and healthcare systems by causing ongoing discomfort, diminished quality of life, and increased expenses. In light of the progress made in treatments, the limited effectiveness and negative side effects of present pharmaceuticals need a more comprehensive comprehension of the underlying processes in order to develop more precise remedies. Exosomes, which are tiny vesicles that play a vital role in cell communication, have been identified as prospective vehicles for effective delivery of anti-inflammatory medicines, immunomodulators, and gene treatments. Vesicles, which are secreted by different cells, have a crucial function in communicating between cells. This makes them valuable in the fields of diagnostics and therapies, particularly for inflammatory conditions. Exosomes have a role in regulating the immune system, transporting cytokines, and influencing cell signaling pathways associated with inflammation. They consist of proteins, lipids, and genetic information that have an impact on immune responses and inflammation. Scientists are now investigating exosomes as biomarkers for inflammatory disease. This review article aims to develop non-invasive diagnostic techniques with improved sensitivity and specificity. Purpose of this review is a thorough examination of exosomes in pharmacology, specifically emphasizing their origin, contents, and functions, with the objective of enhancing diagnostic and therapeutic strategies for inflammatory conditions. Gaining a comprehensive understanding of the intricate mechanisms involved in exosome-mediated interactions and their impact on immune responses is of utmost importance in order to devise novel approaches for tackling inflammatory disease and enhancing patient care.

Endosome mediated nucleocytoplasmic trafficking and endomembrane allocation is crucial to polyglutamine toxicity

Aggregation of aberrant proteins is a common pathological hallmark in neurodegeneration such as polyglutamine (polyQ) and other repeat-expansion diseases. Here through overexpression of ataxin3 C-terminal polyQ expansion in Drosophila gut enterocytes, we generated an intestinal obstruction model of spinocerebellar ataxia type3 (SCA3) and reported a new role of nuclear-associated endosomes (NAEs)-the delivery of polyQ to the nucleoplasm. In this model, accompanied by the prominently increased RAB5-positive NAEs are abundant nucleoplasmic reticulum enriched with polyQ, abnormal nuclear envelope invagination, significantly reduced endoplasmic reticulum, indicating dysfunctional nucleocytoplasmic trafficking and impaired endomembrane organization. Consistently, Rab5 but not Rab7 RNAi further decreased polyQ-related NAEs, inhibited endomembrane disorganization, and alleviated disease model. Interestingly, autophagic proteins were enriched in polyQ-related NAEs and played non-canonical autophagic roles as genetic manipulation of autophagic molecules exhibited differential impacts on NAEs and SCA3 toxicity. Namely, the down-regulation of Atg1 or Atg12 mitigated while Atg5 RNAi aggravated the disease phenotypes both in Drosophila intestines and compound eyes. Our findings, therefore, provide new mechanistic insights and underscore the fundamental roles of endosome-centered nucleocytoplasmic trafficking and homeostatic endomembrane allocation in the pathogenesis of polyQ diseases.

Associations of cold-inducible RNA-binding protein with bacterial load, proinflammatory cytokines and mortality from pneumonia

Cold-inducible RNA-binding protein (CIRP) is a damage-associated molecular pattern that plays a critical role in triggering inflammatory responses. It remains unknown whether CIRP is strongly associated with bacterial load, inflammatory response, and mortality in sepsis model. Pneumonia was induced in specific pathogen-free 8-9-week old male rats by injecting bacteria via puncture of the tracheal cartilage. The expressions of CIRP and proinflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β] in lung tissues, alveolar macrophages (AMs), plasma, and bronchoalveolar lavage fluid (BALF) were determined by reverse transcription-polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay. The numbers of bacteria recovered from the lungs were correlated with the bacterial loads injected and mortality. The expressions of CIRP increased sharply as the bacterial loads increased in the lung tissues and AMs. The amounts of TNF-α, IL-6 and IL-1β proteins synthesized were dependent on the bacterial load in the lung tissues. Releases of CIRP, TNF-α, IL-6, and IL-1β increased with the bacterial load in the blood plasma. The proteins confirmed similar patterns in the BALF. CIRP was strongly associated with the releases of TNF-α, IL-6, and IL-1β in the lung tissues, blood plasma, and BALF, and showed a close correlation with mortality. CIRP demonstrated a strong association with bacterial load, which is new evidence, and close correlations with proinflammatory cytokines and mortality of pneumonia in rats, suggesting that it might be an interesting pneumonic biomarker for monitoring host response and predicting mortality, and a promising target for immunotherapy.

Extracellular CIRP induces abnormal activation of fibroblast-like synoviocytes from patients with RA via the TLR4-mediated HDAC3 pathways

The development of rheumatoid arthritis (RA) is closely related to the excessive activation of fibroblast-like synoviocytes (FLSs), which are regulated by a variety of endogenous proinflammatory molecules. Extracellular cold-inducible RNA-binding protein (CIRP), as a novel endogenous proinflammatory molecule, plays an important role in inflammatory diseases. More importantly, the synovial concentration of CIRP in patients with RA was significantly higher than that in patients with osteoarthritis (OA). Thus, this study aimed to investigate the role of extracellular CIRP in the abnormal activation of RA-FLSs and its related mechanisms. Our study showed that extracellular CIRP induced proliferation, migration and invasion of RA-FLSs, increased the expression of N-cadherin and MMP-3, and promoted the release of IL-1β and IL-33. However, blocking of extracellular CIRP with C23 inhibited CIRP-induced abnormal activation of RA-FLSs and alleviated the arthritis severity in AA rats. Accumulating evidence suggests that the activity and proinflammatory effects of CIRP are mediated through Toll-like receptor 4 (TLR4). Further studies demonstrated that the TLR4 knockdown inhibited CIRP-induced abnormal activation, and histone deacetylase 3 (HDAC3) expression in RA-FLSs. In addition, we found that HDAC3 knockdown and the specific inhibitor RGFP966 significantly suppressed CIRP-induced abnormal activation of RA-FLSs. We further found that treatment with HDAC3 specific inhibitor effectively alleviated the severity of arthritis in AA rats. Taken together, these findings indicate that extracellular CIRP induces abnormal activation of RA-FLSs via the TLR4-mediated HDAC3 pathways.

Cold-Inducible RNA Binding Protein Impedes Breast Tumor Growth in the PyMT Murine Model for Breast Cancer

RNA binding proteins (RBPs) post-transcriptionally regulate gene expression by associating with regulatory sequences in the untranslated regions of mRNAs. Cold-inducible RBP (CIRP) is a stress-induced RBP that was recently shown to modulate inflammation in response to cellular stress, where it increases or decreases pro-tumorigenic (proinflammatory) cytokines in different contexts. CIRP expression is altered in several cancers, including breast cancer, but the effects of CIRP on inflammation in breast cancer is not known. Here, we investigate if CIRP alters growth and the inflammatory profile of breast tumors. Transgenic mice overexpressing CIRP in the mammary epithelium were crossed with the PyMT mouse model of breast cancer, and the effects on both early and late tumorigenesis and inflammation were assessed. The effects of CIRP knockdown were also assessed in Py2T cell grafts. Overexpression of CIRP led to decreased tumorigenesis in the PyMT mouse model. Conversely, the knockdown of CIRP in Py2T cell grafts led to increased tumor growth. Luminex cytokine assays assessed the effects on the inflammatory environment. CIRP/PyMT mammary glands/mammary tumors and serum had decreased cytokines that promote inflammation, angiogenesis, and metastasis compared to PyMT mammary glands and serum, documenting a shift towards an environment less supportive of tumorigenesis. CIRP overexpression also decreased CD4+ helper T cells and increased CD8+ cytotoxic T cells in mammary tumors. Overall, these data support a role for CIRP as a potent antitumor molecule that suppresses both local and systemic pro-tumorigenic inflammation.

Serum CIRP increases the risk of acute kidney injury after cardiac surgery

Introduction

Acute kidney injury (AKI) is a frequent perioperative complication. The underlying mechanisms of cardiac surgery-associated AKI are still not completely elucidated. Cold-induced RNA-binding protein (CIRP) has been subsequently found to be regulated by various stress conditions. During cardiac surgery and cardiopulmonary bypass (CPB), the host is subjected to hypothermia and inadequate organ perfusion, resulting in an upregulation of CIRP secretion. The aim of this study is to evaluate the role of elevated extracellular CIRP level as a contributing factor in the development of AKI.

Methods

A total of 292 patients who underwent cardiac surgery were retrospectively enrolled and their serum samples were collected preoperative and postoperative. Demographic data, intraoperative data, in-hospital outcomes, and the occurrence of AKI were also collected for the patients. The correlation between CIRP and intraoperative procedures, as well as its association with postoperative outcomes were analyzed.

Results

In multivariable analysis, higher ΔCIRP (p = 0.036) and body mass index (p = 0.015) were independent risk factors for postoperative AKI. Meanwhile, patients with postoperative AKI exhibited lower survival rate in 2-year follow-up (p = 0.008). Compared to off-pump coronary artery bypass grafting surgery, patients who underwent on-pump coronary artery bypass grafting, valve surgery, aortic dissection and other surgery showed higher ΔCIRP, measuring 1,093, 666, 914 and 258 pg/mL, respectively (p < 0.001). The levels of ΔCIRP were significantly higher in patients who underwent CPB compared to those who did not (793.0 ± 648.7 vs. 149.5 ± 289.1 pg/mL, p < 0.001). Correlation analysis revealed a positive correlation between ΔCIRP levels and the duration of CPB (r = 0.502, p < 0.001). Patients with higher CIRP levels are at greater risk of postoperative AKI (OR: 1.67, p = 0.032), especially the stage 2-3 AKI (OR: 2.11, p = 0.037).

Conclusion

CIRP secretion increases with prolonged CPB time after cardiac surgery, and CIRP secretion is positively correlated with the duration of CPB. Cardiac surgeries with CPB exhibited significantly higher levels of CIRP compared to non-CPB surgeries. Elevation of CIRP level is an independent risk factor for the incidence of AKI, especially the severe AKI, and were associated with adverse in-hospital outcomes.

Latest progress in low-intensity pulsed ultrasound for studying exosomes derived from stem/progenitor cells

Stem cells have self-renewal, replication, and multidirectional differentiation potential, while progenitor cells are undifferentiated, pluripotent or specialized stem cells. Stem/progenitor cells secrete various factors, such as cytokines, exosomes, non-coding RNAs, and proteins, and have a wide range of applications in regenerative medicine. However, therapies based on stem cells and their secreted exosomes present limitations, such as insufficient source materials, mature differentiation, and low transplantation success rates, and methods addressing these problems are urgently required. Ultrasound is gaining increasing attention as an emerging technology. Low-intensity pulsed ultrasound (LIPUS) has mechanical, thermal, and cavitation effects and produces vibrational stimuli that can lead to a series of biochemical changes in organs, tissues, and cells, such as the release of extracellular bodies, cytokines, and other signals. These changes can alter the cellular microenvironment and affect biological behaviors, such as cell differentiation and proliferation. Here, we discuss the effects of LIPUS on the biological functions of stem/progenitor cells, exosomes, and non-coding RNAs, alterations involved in related pathways, various emerging applications, and future perspectives. We review the roles and mechanisms of LIPUS in stem/progenitor cells and exosomes with the aim of providing a deeper understanding of LIPUS and promoting research and development in this field.

Function and biomedical implications of exosomal microRNAs delivered by parenchymal and nonparenchymal cells in hepatocellular carcinoma

Small extracellular vesicles (exosomes) are important components of the tumor microenvironment. They are small membrane-bound vesicles derived from almost all cell types and play an important role in intercellular communication. Exosomes transmit biological molecules obtained from parent cells, such as proteins, lipids, and nucleic acids, and are involved in cancer development. MicroRNAs (miRNAs), the most abundant contents in exosomes, are selectively packaged into exosomes to carry out their biological functions. Recent studies have revealed that exosome-delivered miRNAs play crucial roles in the tumorigenesis, progression, and drug resistance of hepatocellular carcinoma (HCC). In addition, exosomes have great industrial prospects in the diagnosis, treatment, and prognosis of patients with HCC. This review summarized the composition and function of exosomal miRNAs of different cell origins in HCC and highlighted the association between exosomal miRNAs from stromal cells and immune cells in the tumor microenvironment and the progression of HCC. Finally, we described the potential applicability of exosomal miRNAs derived from mesenchymal stem cells in the treatment of HCC.

Biogenesis and function of exosome lncRNAs and their role in female pathological pregnancy

Preeclampsia, gestational diabetes mellitus, and recurrent spontaneous abortion are common maternal pregnancy complications that seriously endanger women's lives and health, and their occurrence is increasing year after year with a rejuvenation trend. In contrast to biomarkers found freely in tissues or body fluids, exosomes exist in a relatively independent environment and provide a higher level of stability. As backbone molecules, guidance molecules, and signaling molecules in the nucleus, lncRNAs can regulate gene expression. In the cytoplasm, lncRNAs can influence gene expression levels by modifying mRNA stability, acting as competitive endogenous RNAs to bind miRNAs, and so on. Exosomal lncRNAs can exist indefinitely and are important in intercellular communication and signal transduction. Changes in maternal serum exosome lncRNA expression can accurately and timely reflect the progression and regression of pregnancy-related diseases. The purpose of this paper is to provide a reference for clinical research on the pathogenesis, diagnosis, and treatment methods of pregnancy-related diseases by reviewing the role of exosome lncRNAs in female pathological pregnancy and related molecular mechanisms.

The immune suppressive properties of damage associated molecular patterns in the setting of sterile traumatic injury

Associated with the development of hospital-acquired infections, major traumatic injury results in an immediate and persistent state of systemic immunosuppression, yet the underlying mechanisms are poorly understood. Detected in the circulation in the minutes, days and weeks following injury, damage associated molecular patterns (DAMPs) are a heterogeneous collection of proteins, lipids and DNA renowned for initiating the systemic inflammatory response syndrome. Suggesting additional immunomodulatory roles in the post-trauma immune response, data are emerging implicating DAMPs as potential mediators of post-trauma immune suppression. Discussing the results of in vitro, in vivo and ex vivo studies, the purpose of this review is to summarise the emerging immune tolerising properties of cytosolic, nuclear and mitochondrial-derived DAMPs. Direct inhibition of neutrophil antimicrobial activities, the induction of endotoxin tolerance in monocytes and macrophages, and the recruitment, activation and expansion of myeloid derived suppressor cells and regulatory T cells are examples of some of the immune suppressive properties assigned to DAMPs so far. Crucially, with studies identifying the molecular mechanisms by which DAMPs promote immune suppression, therapeutic strategies that prevent and/or reverse DAMP-induced immunosuppression have been proposed. Approaches currently under consideration include the use of synthetic polymers, or the delivery of plasma proteins, to scavenge circulating DAMPs, or to treat critically-injured patients with antagonists of DAMP receptors. However, as DAMPs share signalling pathways with pathogen associated molecular patterns, and pro-inflammatory responses are essential for tissue regeneration, these approaches need to be carefully considered in order to ensure that modulating DAMP levels and/or their interaction with immune cells does not negatively impact upon anti-microbial defence and the physiological responses of tissue repair and wound healing.

Serum cold-inducible RNA-binding protein (CIRP) levels as a prognostic indicator in patients with acute ischemic stroke

Background

Acute ischemic stroke (AIS) is the leading cause of morbidity and mortality among cerebrovascular diseases. While animal studies have suggested a correlation between cold-inducible RNA-binding protein (CIRP) serum levels and the severity and prognosis of cerebral infarction, there has been a lack of research exploring this association in humans with cerebral infarction.

Materials and methods

A total of 148 patients diagnosed with AIS within 7 days from symptom onset were included in this study. Comprehensive information regarding the patients' basic demographics, medical history, clinical parameters, the severity of cerebral infarction, and serum CIRP levels was collected. Follow-up data were obtained through telephonic interviews or by reviewing clinical notes for 3 months after the patients were discharged to assess the functional outcomes of treatment.

Results

The findings of this study demonstrated a significant increase in serum CIRP levels during the early stages of AIS, followed by a gradual decline after 3 days. Significant differences were observed in the serum CIRP levels between the 1-day group and the 4-7 day group (P < 0.0047), as well as between the 2-3 day group and the 4-7 day group (P < 0.0006). Moreover, a significant positive correlation was observed between the serum CIRP levels and the severity of cerebral infarction. Higher serum CIRP levels were associated with more severe National Institutes of Health Stroke Scale scores (P < 0.05) and larger cerebral infarction volumes (P < 0.05). Furthermore, patients with higher serum CIRP levels exhibited poorer modified Rankin scale scores (P < 0.05). These findings indicate that serum CIRP serves as an essential pro-inflammatory mediator and a valuable biomarker for assessing brain injury in patients with AIS.

Conclusion

The findings of this study suggest an elevation in serum CIRP levels among patients with AIS. These levels are positively correlated with the severity of AIS and serve as indicators of a poor prognosis. Therefore, CIRP could serve as a target for early clinical intervention while managing AIS, and further research should explore serum CIRP levels as prognostic indicators in AIS.

A comprehensive overview of exosome lncRNAs: emerging biomarkers and potential therapeutics in endometriosis

Endometriosis is a gynecological condition that significantly impacting women's daily lives. In recent years, the incidence of endometriosis has been rising yearly and is now an essential contributor to female infertility. Exosomes are extracellular vesicles (EVs) that carry long noncoding RNA (lncRNA) and shield lncRNA from the outside environment thanks to their vesicle-like structure. The role of exosome-derived lncRNAs in endometriosis is also receiving more study as high-throughput sequencing technology develops. Several lncRNAs with variable expression may be crucial to the emergence and growth of endometriosis. The early diagnosis of endometriosis will be considerably improved by further high specificity and sensitivity Exosome lncRNA screening. Exosomes assist lncRNAs in carrying out their roles, offering a new target for creating endometriosis-specific medications. In order to serve as a reference for clinical research on the pathogenesis, diagnosis, and treatment options of endometriosis, this paper covers the role of exosome lncRNAs in endometriosis and related molecular mechanisms.