Exosomes in Nephropathies: A Rich Source of Novel Biomarkers

Extracellular Vesicles in Renal Inflammatory Diseases: Revealing Mechanisms of Extracellular Vesicle-Mediated Macrophage Regulation

Renal inflammatory diseases are a group of severe conditions marked by significant morbidity and mortality. Extracellular vesicles (EVs), as facilitators of intercellular communication, have been recognized as pivotal regulators of renal inflammatory diseases, significantly contributing to these conditions by modulating immune responses among other mechanisms. This review highlights the intricate mechanisms through which EVs modulate macrophage-kidney cell interactions by regulating macrophages, the principal immune cells within the renal milieu. This regulation subsequently influences the pathophysiology of renal inflammatory diseases such as acute kidney injury and chronic kidney disease. Furthermore, understanding these mechanisms offers novel opportunities to alleviate the severe consequences associated with renal inflammatory diseases. In addition, we summarize the therapeutic landscape based on EV-mediated macrophage regulatory mechanisms, highlighting the potential of EVs as biomarkers and therapeutic targets as well as the challenges and limitations of translating therapies into clinical practice.

Concentration of kidney markers and detection of exosomes in urine samples collected in cotton wool balls in preterm and term neonates

Collecting urine samples in neonates by catheterisation or suprapubic puncture causes trauma, whereas self-adhesive collection bags can damage fragile skin. An alternative method is the collection of samples from urine-soaked cotton wool balls placed in diapers. The aim of this study was to compare the concentration of albumin, creatinine, neutrophil gelatinase-associated lipocalin (NGAL), and uromodulin between clean-catch urine and samples collected in cotton wool balls in neonates and assess the efficiency of exosome extraction. Standard clean-catch urine samples were assayed for albumin, creatinine, NGAL, and uromodulin using commercial enzyme-linked immunosorbent assay (ELISA) kits. Concentrations were compared to the same urine samples extracted immediately from soaked cotton wool balls (sample 2, S2) or the urine extracted from cotton wool balls placed in a diaper in a warm incubator for 2 h before extraction (sample 3, S3). Exosomes were extracted from all three samples of one patient for visualisation by electron microscopy. Twenty-six infants (17 males) of median gestational age at birth of 32+1 weeks had urine collected at a median age of 29 days at 37+6 weeks corrected age. Concentrations in S2 and S3 were within 10% of the concentration of standard samples in 46% and 35% of specimens for albumin, 69% and 58% for creatinine, 12% and 12% for NGAL, and 27% and 15% for uromodulin, respectively, without consistent positive or negative bias. Urine albumin/creatinine ratios (UACRs) were 4.3% less in S2 and 4.5% less in S3 than in standard samples. Exosomes were extracted and visualised from all three sample types. Neonatal urine samples extracted from cotton wool balls can be used to screen for relevant albuminuria ​but provide imprecise estimates of NGAL and uromodulin. The proof of exosome extraction from urine collection in cotton wool balls opens the potential to examine exosomal cargo.

Advances and challenges in the use of liquid biopsy in gynaecological oncology

Ovarian cancer, endometrial cancer, and cervical cancer are the three primary gynaecological cancers that pose a significant threat to women's health on a global scale. Enhancing global cancer survival rates necessitates advancements in illness detection and monitoring, with the goal of improving early diagnosis and prognostication of disease recurrence. Conventional methods for identifying and tracking malignancies rely primarily on imaging techniques and, when possible, protein biomarkers found in blood, many of which lack specificity. The process of collecting tumour samples necessitates intrusive treatments that are not suitable for specific purposes, such as screening, predicting, or evaluating the effectiveness of treatment, monitoring the presence of remaining illness, and promptly detecting relapse. Advancements in treatment are being made by the detection of genetic abnormalities in tumours, both inherited and acquired. Newly designed therapeutic approaches can specifically address some of these abnormalities. Liquid biopsy is an innovative technique for collecting samples that examine specific cancer components that are discharged into the bloodstream, such as circulating tumour DNA (ctDNA), circulating tumour cells (CTCs), cell-free RNA (cfRNA), tumour-educated platelets (TEPs), and exosomes. Mounting data indicates that liquid biopsy has the potential to improve the clinical management of gynaecological cancers through enhanced early diagnosis, prognosis prediction, recurrence detection, and therapy response monitoring. Understanding the distinct genetic composition of tumours can also inform therapy choices and the identification of suitable targeted treatments. The main benefits of liquid biopsy are its non-invasive characteristics and practicality, enabling the collection of several samples and the continuous monitoring of tumour changes over time. This review aims to provide an overview of the data supporting the therapeutic usefulness of each component of liquid biopsy. Additionally, it will assess the benefits and existing constraints associated with the use of liquid biopsy in the management of gynaecological malignancies. In addition, we emphasise future prospects in light of the existing difficulties and investigate areas where further research is necessary to clarify its rising clinical capabilities.

Future embracing: exosomes driving a revolutionary approach to the diagnosis and treatment of idiopathic membranous nephropathy

Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults and is associated with high rates of end-stage renal disease. Early detection and precise interventions are crucial for improving patient prognosis and quality of life. However, the current diagnosis primarily relies on renal biopsies and traditional biomarkers, which have limitations. Additionally, targeted therapeutic strategies are lacking. Exosomes, small vesicles that facilitate intercellular communication, have emerged as potential noninvasive diagnostic markers due to their stability, diverse cargo, and rapid detectability. They also hold promise as carriers for gene and drug delivery, presenting innovative opportunities in renal disease prognosis and treatment. However, research on exosomes in the context of idiopathic membranous nephropathy (IMN) remains limited, with a focus on exploring urinary exosomes as IMN markers. In this review, we summarize the current status of MN diagnosis and treatment, highlight the fundamental characteristics of exosomes, and discuss recent advancements in their application to IMN diagnosis and therapy. We provide insights into the clinical prospects of exosomes in IMN and acknowledge potential challenges. This article aims to offer forward-looking insights into the future of exosome-mediated IMN diagnosis and treatment, indicating a revolutionary transformation in this field.

Proteomics of urinary small extracellular vesicles in early diagnosis of kidney diseases in children-expectations and limitations

The primary function of the kidneys is to maintain systemic homeostasis (disruption of renal structure and function results in multilevel impairment of body function). Kidney diseases are characterized by a chronic, progressive course and may result in the development of chronic kidney disease (CKD). Evaluation of the composition of the proteome of urinary small extracellular vesicles (sEVs) as a so-called liquid biopsy is a promising new research direction. Knowing the composition of sEV could allow localization of cellular changes in specific sections of the nephron or the interstitial tissue before fixed changes, detectable only at an advanced stage of the disease, occur. Research is currently underway on the role of sEVs in the diagnosis and monitoring of many disease entities. Reports in the literature on the subject include: diabetic nephropathy, focal glomerulosclerosis in the course of glomerulopathies, renal fibrosis of various etiologies. Studies on pediatric patients are still few, involving piloting if small groups of patients without validation studies. Here, we review the literature addressing the use of sEV for diagnosis of the most common urinary disorders in children. We evaluate the clinical utility and define limitations of markers present in sEV as potential liquid biopsy.

Source Tracing of Kidney Injury via the Multispectral Fingerprint Identified by Machine Learning-Driven Surface-Enhanced Raman Spectroscopic Analysis

Early diagnosis of drug-induced kidney injury (DIKI) is essential for clinical treatment and intervention. However, developing a reliable method to trace kidney injury origins through retrospective studies remains a challenge. In this study, we designed ordered fried-bun-shaped Au nanocone arrays (FBS NCAs) to create microarray chips as a surface-enhanced Raman scattering (SERS) analysis platform. Subsequently, the principal component analysis (PCA)-two-layer nearest neighbor (TLNN) model was constructed to identify and analyze the SERS spectra of exosomes from renal injury induced by cisplatin and gentamycin. The established PCA-TLNN model successfully differentiated the SERS spectra of exosomes from renal injury at different stages and causes, capturing the most significant spectral features for distinguishing these variations. For the SERS spectra of exosomes from renal injury at different induction times, the accuracy of PCA-TLNN reached 97.8% (cisplatin) and 93.3% (gentamicin). For the SERS spectra of exosomes from renal injury caused by different agents, the accuracy of PCA-TLNN reached 100% (7 days) and 96.7% (14 days). This study demonstrates that the combination of label-free exosome SERS and machine learning could serve as an innovative strategy for medical diagnosis and therapeutic intervention.

Exosomes: Toward a potential application in bladder cancer diagnosis and treatment

Bladder cancer (BC) is a prevalent malignant tumor of the urinary system, known for its rapid progression and high likelihood of recurrence. Despite ongoing efforts, clinical diagnosis and treatment of BC remain limited. As such, there is an urgent need to investigate potential mechanisms underlying this disease. Exosomes, which contain a variety of bioactive molecules such as nucleic acids, proteins, and lipids, are regarded as extracellular messengers because they are implicated in facilitating intercellular communication in various diseases and are pivotal in tumor advancement, serving as a promising avenue for such researches. Nevertheless, the heterogeneous nature of BC necessitates further exploration of the potential involvement of exosomes in disease progression. This review comprehensively outlines the biological attributes of exosomes and their critical roles in tumorigenesis, while also discussing their potential applications in regulating the progression of BC involving clinical diagnosis, prognostication and treatment.

Exosomes on Endometrial Cancer: A Biomarkers Treasure Trove?

Endometrial cancer (EC) is one of the main causes of cancer-related death among women. In the last decade, the incidence of EC is on the rise, and the relative 5-year survival remains unchanged. This creates a dire need for new diagnostic and therapeutic approaches that can only result from a deeper understanding of the pathogenesis of the disease. In this direction, exosomes are under heavy research, with two main aims: to identify the potential diagnostic and prognostic markers and to develop technologies based on their use as therapeutic vectors targeting EC cells. Exosomes are widely available in all bodily fluids and are sources of ideal biomarkers for liquid biopsies. They are extracellular vesicles containing DNA, RNA, lipids, and proteins, which they transfer between cells, serving multiple functions and being implicated in both the physiological processes and the pathogenesis of diseases. Of all the biomolecules contained in exosomes, microRNAs (miRNAs) seem to have the most clinical utility in the diagnosis and treatment of EC. Exosomal miRNAs mediate the communication between EC cells, cancer-associated fibroblasts (CAFs), and tumor-associated macrophages (TAMs) and have a pivotal role in the tumor cells' proliferation, epithelial to mesenchymal transition (EMT), and the formation of a tumor microenvironment. They participate in many processes that are tied to carcinogenesis and cancer progression, and they are therefore considered as attractive therapeutic targets. Here, we review the functions of exosomes in EC, focusing on potential biomarkers of diagnostic and prognostic significance or potential therapeutic use.

Exosomes in the Treatment of Pancreatic Cancer: A Moonshot to PDAC Treatment?

Pancreatic Ductal Adenocarcinoma (PDAC) constitutes a leading cause of cancer death globally. Its mortality remains unaltered despite the considerable scientific progress made in the fields of diagnostics and treatment. Exosomes comprise of small extracellular vesicles secreted by nearly all cells; their cargo contains a vast array of biomolecules, such as proteins and microRNAs. It is currently established that their role as messengers is central to a plethora of both physiologic and pathologic processes. Accumulating data have shed light on their contributions to carcinogenesis, metastasis, and immunological response. Meanwhile, the advancement of personalized targeted therapies into everyday clinical practice necessitates the development of cost-efficient treatment approaches. The role of exosomes is currently being extensively investigated towards this direction. This review aims to summarize the current pre-clinical and clinical evidence regarding the effects of exosomal applications in the timely diagnosis, prognosis, and therapeutic management of pancreatic cancer.

Efficacy of Modified Huangqi Chifeng decoction in alleviating renal fibrosis in rats with IgA nephropathy by inhibiting the TGF-β1/Smad3 signaling pathway through exosome regulation

ETHNOPHARMACOLOGICAL RELEVANCE

IgA nephropathy is the most common form of primary glomerulonephritis and is a major cause of renal failure worldwide. Modified Huangqi Chifeng decoction (MHCD), a traditional Chinese herbal preparation, has clinical efficacy in reducing the 24-h urine protein levels in patients with IgA nephropathy. However, the molecular mechanism of MHCD needs further study.

AIM OF THE STUDY

This study aimed to investigate the mechanisms by which MHCD treatment alleviates renal fibrosis.

MATERIALS AND METHODS

An IgA nephropathy rat model was established using bovine serum albumin, carbon tetrachloride, and lipopolysaccharide. The rats were divided into control, model, telmisartan, low-dose MHCD, medium-dose MHCD, and high-dose MHCD groups. Treatments were administered to these groups for 8 weeks. Subsequently, the 24-h urine protein, serum creatinine, blood urea nitrogen, and blood albumin levels were measured. Pathological changes and degree of fibrosis in renal tissues were observed, and levels of the transforming growth factor-β1 (TGF-β1)/Smad3 signaling pathway components in renal tissues and TGF-β1 in urinary exosomes were measured.

RESULTS

Telmisartan and MHCD reduced 24-h urine protein levels, alleviated renal pathological injury, and decreased the renal expression of fibronectin, laminin, and collagen IV in rats with IgA nephropathy. Urinary exosomes were extracted and identified for further investigation of their role in renal fibrosis. MHCD reduced TGF-β1 expression in urinary exosomes and reduced TGF-β1 and p-Smad3 levels in renal tissues.

CONCLUSION

MHCD alleviated renal fibrosis in rats with IgA nephropathy by inhibiting the TGF-β1/Smad3 signaling pathway through the downregulation of TGF-β1 expression in exosomes.

Proteomic profile of mesothelial exosomes isolated from peritoneal dialysis effluent of children with focal segmental glomerulosclerosis

Peritoneal dialysis (PD) is the worldwide recognized preferred dialysis treatment for children affected by end-stage kidney disease (ESKD). However, due to the unphysiological composition of PD fluids, the peritoneal membrane (PM) of these patients may undergo structural and functional alterations, which may cause fibrosis. Several factors may accelerate this process and primary kidney disease may have a causative role. In particular, patients affected by steroid resistant primary focal segmental glomerulosclerosis, a rare glomerular disease leading to nephrotic syndrome and ESKD, seem more prone to develop peritoneal fibrosis. The mechanism causing this predisposition is still unrecognized. To better define this condition, we carried out, for the first time, a new comprehensive comparative proteomic mass spectrometry analysis of mesothelial exosomes from peritoneal dialysis effluent (PDE) of 6 pediatric patients with focal segmental glomerular sclerosis (FSGS) versus 6 patients affected by other primary renal diseases (No FSGS). Our omic study demonstrated that, despite the high overlap in the protein milieu between the two study groups, machine learning allowed to identify a core list of 40 proteins, with ANXA13 as most promising potential biomarker, to distinguish, in our patient population, peritoneal dialysis effluent exosomes of FSGS from No FSGS patients (with 100% accuracy). Additionally, the Weight Gene Co-expression Network Analysis algorithm identified 17 proteins, with PTP4A1 as the most statistically significant biomarker associated to PD vintage and decreased PM function. Altogether, our data suggest that mesothelial cells of FSGS patients are more prone to activate a pro-fibrotic machinery. The role of the proposed biomarkers in the PM pathology deserves further investigation. Our results need further investigations in a larger population to corroborate these findings and investigate a possible increased risk of PM loss of function or development of encapsulating peritoneal sclerosis in FSGS patients, thus to eventually carry out changes in PD treatment and management or implement new solutions.

The Role of Non-Immune Cell-Derived Extracellular Vesicles in Allergy

Extracellular vesicles (EVs), and especially exosomes, have been shown to mediate information exchange between distant cells; this process directly affects the biological characteristics and functionality of the recipient cell. As such, EVs significantly contribute to the shaping of immune responses in both physiology and disease states. While vesicles secreted by immune cells are often implicated in the allergic process, growing evidence indicates that EVs from non-immune cells, produced in the stroma or epithelia of the organs directly affected by inflammation may also play a significant role. In this review, we provide an overview of the mechanisms of allergy to which those EVs contribute, with a particular focus on small EVs (sEVs). Finally, we also give a clinical perspective regarding the utilization of the EV-mediated communication route for the benefit of allergic patients.

Urinary Extracellular Vesicles: Uncovering the Basis of the Pathological Processes in Kidney-Related Diseases

Intercellular communication governs multicellular interactions in complex organisms. A variety of mechanisms exist through which cells can communicate, e.g., cell-cell contact, the release of paracrine/autocrine soluble molecules, or the transfer of extracellular vesicles (EVs). EVs are membrane-surrounded structures released by almost all cell types, acting both nearby and distant from their tissue/organ of origin. In the kidney, EVs are potent intercellular messengers released by all urinary system cells and are involved in cell crosstalk, contributing to physiology and pathogenesis. Moreover, urine is a reservoir of EVs coming from the circulation after crossing the glomerular filtration barrier—or originating in the kidney. Thus, urine represents an alternative source for biomarkers in kidney-related diseases, potentially replacing standard diagnostic techniques, including kidney biopsy. This review will present an overview of EV biogenesis and classification and the leading procedures for isolating EVs from body fluids. Furthermore, their role in intra-nephron communication and their use as a diagnostic tool for precision medicine in kidney-related disorders will be discussed.

Extracellular Vesicles as Biomarkers Carriers in Bladder Cancer: Diagnosis, Surveillance, and Treatment

Exosomes are extracellular vesicles, enriched in biomolecular cargo consisting of nucleic acids, proteins, and lipids, which take part in intercellular communication and play a crucial role in both physiologic functions and oncogenesis. Bladder cancer is the most common urinary malignancy and its incidence is steadily rising in developed countries. Despite the high five-year survival in patients diagnosed at early disease stage, survival substantially drops in patients with muscle-invasive or metastatic disease. Therefore, early detection of primary disease as well as recurrence is of paramount importance. The role that exosomal biomarkers could play in bladder cancer patient diagnosis and surveillance, as well as their potential therapeutic applications, has not been extensively studied in this malignancy. In the present review, we summarize all relevant data obtained so far from cell lines, animal models, and patient biofluids and tissues. Current literature suggests that urine is a rich source of extracellular vesicle-derived biomarkers, compared with blood and bladder tissue samples, with potential applications in bladder cancer management. Further studies improving sample collection procedures and optimizing purification and analytical methods should augment bladder cancer diagnostic, prognostic, and therapeutic input of extracellular vesicles biomarkers in the future.

Exosomes as Drug Delivery Systems: Endogenous Nanovehicles for Treatment of Systemic Lupus Erythematosus

Exosomes, nanometer-sized lipid-bilayer-enclosed extracellular vesicles (EVs), have attracted increasing attention due to their inherent ability to shuttle proteins, lipids and genes between cells and their natural affinity to target cells. Their intrinsic features such as stability, biocompatibility, low immunogenicity and ability to overcome biological barriers, have prompted interest in using exosomes as drug delivery vehicles, especially for gene therapy. Evidence indicates that exosomes play roles in both immune stimulation and tolerance, regulating immune signaling and inflammation. To date, exosome-based nanocarriers delivering small molecule drugs have been developed to treat many prevalent autoimmune diseases. This review highlights the key features of exosomes as drug delivery vehicles, such as therapeutic cargo, use of targeting peptide, loading method and administration route with a broad focus. In addition, we outline the current state of evidence in the field of exosome-based drug delivery systems in systemic lupus erythematosus (SLE), evaluating exosomes derived from various cell types and engineered exosomes.