Cardiac and kidney diseases are intimately linked through numerous pathophysiological pathways, frequently exerting reciprocal influences on one another. This interconnection often culminates in heightened morbidity and mortality rates within the clinical spectrum of cardiorenal syndrome (CRS). CRS is categorized into five types based on the primary organ involved and the chronicity of the condition. Each type of CRS encompasses a complex array of pathophysiological mechanisms. In recent years, the field of microRNAs (miRNAs) has risen to prominence, playing a crucial role in the pathogenesis of a multitude of diseases. By uncovering novel therapeutic targets through the study of miRNAs that influence the expression of the CRS genes, the prognostic outcomes for patients could be significantly improved. This article provides a comprehensive review, examining the pathophysiological underpinnings of CRS, miRNAs alterations and their associated mechanisms in various forms of CRS, as well as the potential of miRNAs in precision medicine and the use of miRNAs for the diagnosis of the disease.

Renal ischemia-reperfusion injury (RIRI) is a serious kidney condition that causes significant damage due to lack of blood flow. This injury leads to oxidative stress and inflammation, which can cause acute tubular necrosis and kidney failure. Stem cell-derived exosomes, small vesicles released by stem cells, have shown promise in treating RIRI. Mesenchymal stem cells (MSCs) have been used to mitigate RIRI, and their exosomes have been found to play a crucial role in repairing damaged tissues. This review explores the key roles of exosomes from different sources of MSCs in RIRI, the potential of MSC-derived exosomes in treating this disease, and future research directions.

Acute kidney injury (AKI) is a clinical syndrome caused by various etiologies and causes a rapid decline in renal function in a short period of time. The most common internal modification of mRNAs is the N6-methyladenosine (m6A) modification, which is important for controlling gene expressions. However, the role of m6A modification in AKI is largely unknown. Here, we characterized the role of zinc finger CCCH-type containing 13 (ZC3H13), which is a type of m6A methyltransferases, in cisplatin-induced AKI mouse model and a cisplatin-treated human proximal tubular epithelial cell line (HK2 cells). The ZC3H13 knockdown attenuated the G2/M cell cycle arrest and apoptosis in HK2 cells. In the ZC3H13-overexpressed HK2 cells, the opposite was true. In the presence of cisplatin, mice with the AAV9-mediated silencing of ZC3H13 exhibited milder cell cycle arrest, apoptosis, and renal injury. In addition, we identified nucleic acid binding protein 1 (NABP1) as a target of ZC3H13, which was verified by knocking down and overexpressing ZC3H13 in HK2 cells. Moreover, we confirmed that the ZC3H13-mediated m6A modification stabilized NABP1 mRNA and was discriminated by insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1). In conclusion, ZC3H13 promoted the m6A modification of NABP1 and enhanced its mRNA stability through an IGF2BP1-dependent mechanism. The inhibition of ZC3H13 alleviated the G2/M cell cycle arrest, apoptosis and kidney injury by affecting the expression of NABP1. These results show that the ZC3H13/NABP1 axis is a promising AKI treatment target.

Human umbilical cord mesenchymal stem cells-derived extracellular vesicles (HUMSC-EVs) have drawn much interest in kidney transplantation, mainly because of their renoprotection by alleviating cell injury and stimulating tissue repair. Cellular senescence has been proven to play a dual regulatory role in kidney ischemia-reperfusion injury (IRI), and the regulation of HUMSC-EVs on tubular epithelial cell senescence may be a potential therapeutic target.

In vitro , the hypoxia-reoxygenation of human kidney-2 cells was used to simulate kidney IRI, and the regulation of HUMSC-EVs on human kidney-2 cells was detected. Transcriptome sequencing of human kidney-2 cells was used to explore the potential regulatory mechanism. In vivo , adult male mice were divided into five groups: control group, IRI group, HUMSC-EVs treatment group, senolytics treatment group (dasatinib + quercetin), and combined treatments group (HUMSC-EVs and senolytics). Kidney function, senescent features of tubular epithelial cells, acute kidney injury, and chronic interstitial fibrosis in mice were detected to explore the renoprotection effects of HUMSC-EVs.

Kidney IRI significantly up-regulated expressions of LaminB1, p53, p21, p16, senescence-associated beta-galactosidase, and apoptosis of tubular epithelial cells. In the mouse kidney IRI model, kidney subcapsular injection of HUMSC-EVs significantly improved kidney function, reducing the senescent features of tubular epithelial cells and alleviating acute kidney injury and chronic interstitial fibrosis. HUMSC-EVs mainly achieved renoprotection by regulating Bax/Bcl-2-dependent apoptosis during acute kidney injury and mostly reduced tubular atrophy and kidney interstitial fibrosis by regulating Ras-pERK-Ets1-p53 pathway-dependent cell senescence. Oral administration of senolytics also alleviated kidney injury induced by IRI, while the combined treatments of HUMSC-EVs and senolytics had better renoprotection effects.

The combination of HUMSC-EVs and senolytics alleviated acute kidney injury and chronic interstitial fibrosis by dynamic regulation of cell senescence and apoptosis, which provides a therapeutic potential strategy for organ preservation and tissue repair in kidney transplantation.

Ischemia-reperfusion (IR) injury can result in acute renal failure. Oxidative stress is a major factor in IR-induced cell death in the kidneys. According to traditional Chinese medicine, earthworms (Pheretima aspergillum) can be used to treat various kidney diseases.

The present study was designed to understand the protective effects of the water extract of earthworms (WEE) against oxidative stress on the kidneys and the crucial molecular events associated with its nephroprotective activity.

Cytotoxicity caused by H2O2 in HEK293, HK2, and primary mouse renal tubular epithelial cells (TECs) was used to investigate the effect of WEE on oxidative stress-induced renal injury in vitro. IR-induced kidney injury was established using rats as an in vivo model. The WEE-mediated protection of the kidneys against oxidative stress was compared with that of glutathione, a common antioxidant used as a positive control.

In HEK293 cells, HK2 cells, and primary mouse TECs, WEE relieved H2O2-induced mitochondrial damage, apoptosis, and ferroptosis. In kidney cells, WEE increased the expression of Sirt1, boosted LKB1 and AMPK phosphorylation, and upregulated nuclear Nrf2. Suppression of Sirt1 and LKB1 knock down abrogated WEE-induced protection against H2O2. WEE ameliorated IR-induced kidney injury and intrarenal inflammation in rats. In rat kidneys, WEE mitigated mitochondrial damage and suppressed IR-induced apoptosis and ferroptosis. Mechanistically, WEE increased Sirt1 expression, enhanced the phosphorylation of LKB1 and AMPK, and increased intranuclear Nrf2 levels in IR kidneys. IR treatment resulted in considerable increase in renal MDA levels and a prominent decrease in antioxidative enzyme activity. These lesions were significantly alleviated by WEE.

WEE mitigated H2O2-induced cytotoxicity in kidney cells in vitro and improved IR-induced kidney damage in rats. Mechanistically, WEE potentiated the Sirt1/Nrf2 axis and relieved mitochondrial damage in the kidney cells. These events inhibited the apoptosis and ferroptosis induced by oxidative stress. Our findings support the potential application of WEE for the clinical treatment of kidney diseases caused by intrarenal oxidative stress.

Ischemia-reperfusion injury (IRI) commonly occurs in clinical settings, particularly in medical practices such as organ transplantation, cardiopulmonary resuscitation, and recovery from acute trauma, posing substantial challenges in clinical therapies. Current systemic therapies for IRI are limited by poor drug targeting, short efficacy, and significant side effects. Owing to their exceptional biocompatibility, biodegradability, excellent mechanical properties, targeting capabilities, controlled release potential, and properties mimicking the extracellular matrix (ECM), hydrogels not only serve as superior platforms for therapeutic substance delivery and retention, but also facilitate bioenvironment cultivation and cell recruitment, demonstrating significant potential in IRI treatment. This review explores the pathological processes of IRI and discusses the roles and therapeutic outcomes of various hydrogel systems. By categorizing hydrogel systems into depots delivering therapeutic agents, scaffolds encapsulating mesenchymal stem cells (MSCs), and ECM-mimicking hydrogels, this article emphasizes the selection of polymers and therapeutic substances, and details special crosslinking mechanisms and physicochemical properties, as well as summarizes the application of hydrogel systems for IRI treatment. Furthermore, it evaluates the limitations of current hydrogel treatments and suggests directions for future clinical applications.

Cell-secreted nanovesicles of endosomal origin, called exosomes, are vital for mediating intracellular communication. As local or distal transporters of intracellular cargo, they reflect the unique characteristics of secretory cells and establish cell-specific interactions via characteristic surface proteins and receptors. With the advent of rapid isolation, purification, and identification techniques, exosomes have become an attractive choice for disease diagnosis (exosomal content as biomarkers), cell-free therapy, and tissue regeneration. Mesenchymal stem cell (MSC)-derived exosomes (MSC-exosomes) display angiogenic, immune-modulatory, and other therapeutic effects crucial for cytoprotection, ischemic wound repair, myocardial regeneration, etc. The primary focus of this review is to highlight the widespread application of MSC-exosomes in therapeutics, theranostics, and tissue regeneration. After a brief introduction of exosome properties, biogenesis, isolation, and functions, recent studies on therapeutic and regenerative applications of MSC-exosomes are described, focusing on bone, cartilage, periodontal, cardiovascular, skin, and nerve regeneration. Finally, the review highlights the theranostic potential of exosomes followed by challenges, summary, and outlook.

Ischemia-reperfusion injury (IRI) is a predominant factor leading to delayed graft function (DGF) following kidney transplantation. MicroRNAs (miRNAs) play a pivotal role in the pathogenesis of renal IRI, with ferroptosis being a critical driving force throughout the process. In this study, we utilized bioinformatics methods to construct a network diagram of differentially expressed miRNAs, transcription factors (TFs), and ferroptosis-related genes. An I/R-induced renal injury model in mice and an in vitro H/R-induced HK-2 cell injury model were established. Quantitative real-time PCR (qRT-PCR) and Western blot analysis were used to measure the mRNA and miRNA levels in cells and tissues. The MDA concentration, iron levels, and GSH concentration were measured to evaluate the ferroptosis levels. CCK-8 assays were performed to assess cell viability. Luciferase reporter assays were conducted to validate the downstream targets of miRNA, and chromatin immunoprecipitation assays were performed to verify the interaction between TFs and mRNAs. Both the in vivo and in vitro results demonstrate that miR-451a was significantly enriched in the IRI renal tissues and cells, exacerbating ferroptosis. MiR-451a was found to reduce the expression of Kruppel-like factor 1 (KLF1) by directly binding to the 3'UTR of KLF1 mRNA. Additionally, KLF1 was identified as a negative transcription factor for acyl-CoA synthetase long-chain family member 4 (ACSL4). We demonstrated that IRI induced the upregulation of miR-451a, which reduced KLF1 expression, thereby promoting ferroptosis by upregulating ACSL4 expression, ultimately aggravating IRI-induced renal damage.

Many strategies for regenerating the damaged tissues or degenerating cells are employed in regenerative medicine. Stem cell technology is a modern strategy of the recent approaches, particularly the use of mesenchymal stem cells (MCSs). The ability of MSCs to differentiate as well as their characteristic behaviour as paracrine effector has established them as key elements in tissue repair. Recently, extracellular vesicles (EVs) shed by MSCs have emerged as a promising cell free therapy. This comprehensive review encompasses MSCs-derived exosomes and their therapeutic potential as nanotherapeutics. We also discuss their potency as drug delivery nano-carriers in comparison with liposomes. A better knowledge of EVs behaviour in vivo and of their mechanism of action are key to determine parameters of an optimal formulation in pilot studies and to establish industrial processes.

Kidney diseases represent a diverse range of conditions that compromise renal function and structure which characterized by a progressive deterioration of kidney function, may ultimately necessitate dialysis or kidney transplantation as end-stage treatment options. This review explores the complex landscape of kidney diseases, highlighting the limitations of existing treatments and the pressing need for innovative strategies. The paper delves into the role of extracellular vesicles (EVs) as emerging biomarkers and therapeutic agents in the context of kidney pathophysiology. Urinary extracellular vesicles (uEVs), in particular, offer a non-invasive means of assessing renal injury and monitoring disease progression. Additionally, mesenchymal stem cell-derived EVs (MSC-EVs) are examined for their immunomodulatory and tissue repair capabilities, presenting a promising avenue for novel therapeutic interventions. And discusses the potential of engineering EVs to enhance their targeting and therapeutic efficacy. This paper systematically integrates the latest research findings and aims to provide a comprehensive overview of the role of EVs in kidney disease, providing cutting-edge insights into their potential as a diagnostic and therapeutic tool.

Extracellular vesicles (EVs) are minute sacs released by cells into the extracellular milieu, harboring an array of biomolecules including proteins, nucleic acids, and lipids. Notably, a large number of studies have demonstrated the important involvement of EVs in both physiological and pathological aspects of renal function. EVs can facilitate communication between different renal cells, but it is important to recognize their dual role: they can either transmit beneficial information or lead to renal damage and worsening of existing conditions. The composition of EVs in the context of the kidneys offers valuable insights into the intricate mechanisms underlying specific renal functions or disease states. In addition, mesenchymal stem cell-derived EVs have the potential to alleviate acute and chronic kidney diseases. More importantly, the innate nanoparticle properties of EVs, coupled with their engineering potential, make them effective tools for drug delivery and therapeutic intervention. In this review, we focus on the intricate biological functions of EVs in the kidney. In addition, we explore the emerging role of EVs as diagnostic tools and innovative therapeutic agents in a range of renal diseases.

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.

Introduction: rhabdomyolysis (RM) is a serious syndrome. A large area of muscle injury and dissolution induces acute kidney injury (AKI), which results in a high incidence and mortality rate. Exosomes released by mesenchymal stem cells (MSCs) have been used to treat AKI induced by rhabdomyolysis and have shown regenerative effects. However, the most serious drawbacks of these methods are poor targeting and a low enrichment rate after systemic administration. Methods: in this study, we demonstrated that magnetic exosomes derived from bone marrow mesenchymal stem cells (BMSCs) can directly target damaged muscles rather than kidneys using an external magnetic field. Results: magnetic navigation exosomes reduced the dissolution of damaged muscles, greatly reduced the release of cellular contents, slowed the development of AKI. Discussion: in summary, our proposed method can overcome the shortcomings of poor targeting in traditional exosome therapy. Moreover, in the rhabdomyolysis-induced AKI model, we propose for the first time an exosome therapy mode that directly targets damaged muscles through magnetic navigation.

Cardiotoxicity induced by doxorubicin (Dox) is a major complication in cancer patients. Exosomes (Ex) derived from mesenchymal cells could be a promising therapeutic for various heart diseases. This study investigated the role of Ex in Dox-induced cardiotoxicity and its mechanistic insights, using Sacubitril/valsartan (S/V) as a reference drug widely recommended in heart failure management. The study involved 24 Wistar rats, divided into a control, Dox, Dox + S/V, and Dox + Ex groups. The rats were assessed for cardiac enzymes, inflammatory and oxidative stress markers. Immunohistochemical expression of caspase-1, nuclear factor erythroid 2-related factor 2 (NrF2), E-Cadherin, CD117/c-kit, and Platelet-derived growth factor-α (PDGFα) was evaluated. P53 and Annexin V were assessed by PCR. Histological examination was performed using hematoxylin and eosin and Sirius red stains. Ex ameliorated the adverse cardiac pathological changes and significantly decreased the cardiac enzymes and inflammatory and oxidative stress markers. Ex also exerted antifibrotic and antiapoptotic effect in heart tissue. Ex treatment also improved NrF2 immunohistochemistry, up-regulated E-Cadherin immune expression, and restored the telocyte markers CD117/c-kit and PDGFα. Ex can mitigate Dox-induced cardiotoxicity by acting as an anti-inflammatory, antioxidant, antiapoptotic, and antifibrotic agents, restoring telocytes and modulating epithelial mesenchymal transition. RESEARCH HIGHLIGHTS: Exosomes exhibit positive expression for CD90 and CD105 whereas showing -ve expression for CD 34 by flow cytometry. Exosomes restore the immunohistochemical expression of the telocytes markers CD117/c-kit and PDGFα. Exosomes alleviate myocardial apoptosis, oxidative stress and fibrosis.

Renal ischemia reperfusion (IR) injury is a prevalent inflammatory nephropathy in surgeries such as renal transplantation or partial nephrectomy, damaging renal function through inducing inflammation and cell death in renal tubules. Mesenchymal stromal/stem cell (MSC)-based therapies, common treatments to attenuate inflammation in IR diseases, fail to exhibit satisfying effects on cell death in renal IR. In this study, we prepared MSC-derived exosome mimetics (EMs) carrying the mammalian target of the rapamycin (mTOR) agonist to protect kidneys in proinflammatory environments under IR conditions. The thioketal-modified EMs carried the mTOR agonist and bioactive molecules in MSCs and responsively released them in kidney IR areas. MSC-derived EMs and mTOR agonists protected kidneys synergistically from IR through alleviating inflammation, apoptosis, and ferroptosis. The current study indicates that MSC-TK-MHY1485 EMs (MTM-EM) are promising therapeutic biomaterials for renal IR injury.

Ferroptosis is a predominant contributor to graft kidney ischemia‒reperfusion injury (IRI), resulting in delayed graft function (DGF). However, much less is known about the early predicting biomarkers and therapeutic targets of DGF, especially aiming at ferroptosis. Here, we propose a precise predicting model for DGF, relying on the Akirin1 level in extracellular vesicles (EVs) derived from recipient urine 48 h after kidney transplant. In addition, we decipher a new molecular mechanism whereby Akirin1 induces ferroptosis by strengthening TP53-mediated suppression of SLC7A11 during the graft kidney IRI process, that is, Akirin1 activates the EGR1/TP53 axis and inhibits MDM2-mediated TP53 ubiquitination, accordingly upregulating TP53 in two ways. Meanwhile, we present the first evidence that miR-136-5p enriched in EVs secreted by human umbilical cord mesenchymal stem cells (UM-EVs) confers robust protection against ferroptosis and graft kidney IRI by targeted inhibition of Akirin1 but knockout of miR-136-5p in UM sharply mitigates the protection of UM-EVs. The functional and mechanistic regulation of Akirin1 is further corroborated in an allograft kidney transplant model in wild-type and Akirin1-knockout mice. In summary, these findings suggest that Akirin1, which prominently induces ferroptosis, is a pivotal biomarker and target for early diagnosis and treatment of graft kidney IRI and DGF after kidney transplant.

Kidney diseases are major global health problems, with high prevalence and mortality. However, current treatment strategies for kidney diseases fail to achieve satisfactory efficacy. Mesenchymal stem cell (MSC)-based therapy has been a promising strategy for treating kidney diseases. Preclinical studies have proven their safety and effectiveness in treating acute kidney injury (AKI) and chronic kidney disease (CKD), but the outcomes of clinical trials have shown very limited clinical efficacy. A variety of innovative approaches have been proposed to enhance the therapeutic potential of MSCs, and hydrogels are attractive candidates. Hydrogels are three-dimensional (3D) networks formed by hydrophilic polymers of natural or synthetic origin with diverse physical and chemical properties. They have been widely applied in the field of drug delivery and regenerative medicine, including MSC-based therapy. Many studies have proven that hydrogels can improve the therapeutic efficacy of MSCs for kidney diseases, but there are still challenges limiting the widespread application of this method. In this review, we introduce the application of MSCs in kidney diseases and the factors that influence therapeutic efficiency and focus on the beneficial effects of hydrogels in MSC-based therapy for AKI and CKD.

Acute hypoxic proximal tubule (PT) injury and subsequent maladaptive repair present high mortality and increased risk of acute kidney injury (AKI) - chronic kidney disease (CKD) transition. Human bone marrow mesenchymal stem cell-derived exosomes (hBMMSC-Exos) as potential cell therapeutics can be translated into clinics if drawbacks on safety and efficacy are clarified. Here, we determined the real-time effective dose and treatment window of allogeneic hBMMSC-Exos, evaluated their performance on the structural and functional integrity of 3D microfluidic acute hypoxic PT injury platform.

hBMMSC-Exos were isolated and characterized. Real-time impedance-based cell proliferation analysis (RTCA) determined the effective dose and treatment window for acute hypoxic PT injury. A 2-lane 3D gravity-driven microfluidic platform was set to mimic PT in vitro. ZO-1, acetylated α-tubulin immunolabelling, and permeability index assessed structural; cell proliferation by WST-1 measured functional integrity of PT.

hBMMSC-Exos induced PT proliferation with ED50 of 172,582 µg/ml at the 26th hour. Hypoxia significantly decreased ZO-1, increased permeability index, and decreased cell proliferation rate on 24-48 h in the microfluidic platform. hBMMSC-Exos reinforced polarity by a 1.72-fold increase in ZO-1, restored permeability by 20/45-fold against 20/155 kDa dextran and increased epithelial proliferation 3-fold compared to control.

The real-time potency assay and 3D gravity-driven microfluidic acute hypoxic PT injury platform precisely demonstrated the therapeutic performance window of allogeneic hBMMSC-Exos on ischemic AKI based on structural and functional cellular data. The novel standardized, non-invasive two-step system validates the cell-based personalized theragnostic tool in a real-time physiological microenvironment prior to safe and efficient clinical usage in nephrology.

The imbalance between proliferation and death of kidney resident cells is a crucial factor in the development of acute or chronic renal dysfunction. Acute kidney injury (AKI) is often associated with the rapid loss of tubular epithelial cells (TECs). Sustained injury leads to the loss of glomerular endothelial cells (GECs) and podocytes, which is a key mechanism in the pathogenesis of glomerular diseases. This irreversible damage resulting from progressive cell loss eventually leads to deterioration of renal function characterized by glomerular compensatory hypertrophy, tubular degeneration, and renal fibrosis. Regulated cell death (RCD), which involves a cascade of gene expression events with tight structures, plays a certain role in regulating kidney health by determining the fate of kidney resident cells. Under pathological conditions, cells in the nephron have been demonstrated to constitutively release extracellular vesicles (EVs) which act as messengers that specifically interact with recipient cells to regulate their cell death process. For therapeutic intervention, exogenous EVs have exhibited great potential for the prevention and treatment of kidney disease by modulating RCD, with enhanced effects through engineering modification. Based on the functional role of EVs, this review comprehensively explores the regulation of RCD by EVs in AKI and chronic kidney disease (CKD), with emphasis on pathogenesis and therapeutic intervention.

Cardiovascular diseases (CVDs) continue to be a significant global health concern. Many studies have reported promising outcomes from using MSCs and their secreted exosomes in managing various cardiovascular-related diseases like myocardial infarction (MI). MSCs and exosomes have demonstrated considerable potential in promoting regeneration and neovascularization, as well as exerting beneficial effects against apoptosis, remodeling, and inflammation in cases of myocardial infarction. Nonetheless, ensuring the durability and effectiveness of MSCs and exosomes following in vivo transplantation remains a significant concern. Recently, novel methods have emerged to improve their effectiveness and robustness, such as employing preconditioning statuses, modifying MSC and their exosomes, targeted drug delivery with exosomes, biomaterials, and combination therapy. Herein, we summarize the novel approaches that intensify the therapeutic application of MSC and their derived exosomes in treating MI.

Acute kidney injury (AKI) is a heterogeneous syndrome, comprising diverse etiologies of kidney insults that result in high mortality and morbidity if not well managed. Although great efforts have been made to investigate underlying pathogenic mechanisms of AKI, there are limited therapeutic strategies available. Extracellular vesicles (EV) are membrane-bound vesicles secreted by various cell types, which can serve as cell-free therapy through transfer of bioactive molecules. In this review, we first overview the AKI syndrome and EV biology, with a particular focus on the technical aspects and therapeutic application of cell culture-derived EVs. Second, we illustrate how multi-omic approaches to EV miRNA, protein, and genomic cargo analysis can yield new insights into their mechanisms of action and address unresolved questions in the field. We then summarize major experimental evidence regarding the therapeutic potential of EVs in AKI, which we subdivide into stem cell and non-stem cell-derived EVs. Finally, we highlight the challenges and opportunities related to the clinical translation of animal studies into human patients.

The incidence of acute kidney injury (AKI) due to ischemia-reperfusion (IR) injury is increasing. There is no effective treatment for AKI, and because of this clinical challenge, AKI often progresses to chronic kidney disease, which is closely associated with poor patient outcomes and high mortality rates. Small extracellular vesicles from human umbilical cord mesenchymal stem cells (hUCMSC-sEVs) play increasingly vital roles in protecting tissue function from the effects of various harmful stimuli owing to their specific biological features. In this study, we found that miR-100-5p was enriched in hUCMSC-sEVs, and miR-100-5p targeted FKBP5 and inhibited HK-2 cell apoptosis by activating the AKT pathway. HK-2 cells that were exposed to IR injury were cocultured with hUCMSC-sEVs, leading to an increase in miR-100-5p levels, a decrease in FKBP5 levels, and an increase in AKT phosphorylation at Ser 473 (AKT-473 phosphorylation). Notably, these effects were significantly reversed by transfecting hUCMSCs with an miR-100-5p inhibitor. Moreover, miR-100-5p targeted FKBP5, as confirmed by a dual luciferase reporter assay. In vivo, intravenous infusion of hUCMSC-sEVs into mice suffering from IR injury resulted in significant apoptosis inhibition, functional maintenance and renal histological protection, which in turn decreased FKBP5 expression levels. Overall, this study revealed an effect of hUCMSC-sEVs on inhibiting apoptosis; hUCMSC-sEVs reduced renal IR injury by delivering miR-100-5p to HK-2 cells, targeting FKBP5 and thereby promoting AKT-473 phosphorylation to activate the AKT pathway. This study provides novel insights into the role of hUCMSC-sEVs in the treatment of AKI.

Acute kidney injury (AKI) is a serious clinical syndrome with high morbidity, elevated mortality, and poor prognosis, commonly considered a "sword of Damocles" for hospitalized patients, especially those in intensive care units. Oxidative stress, inflammation, and apoptosis, caused by the excessive production of reactive oxygen species (ROS), play a key role in AKI progression. Hence, the investigation of effective and safe antioxidants and inflammatory regulators to scavenge overexpressed ROS and regulate excessive inflammation has become a promising therapeutic option. However, the unique physiological structure and complex pathological alterations in the kidneys render traditional therapies ineffective, impeding the residence and efficacy of most antioxidant and anti-inflammatory small molecule drugs within the renal milieu. Recently, nanotherapeutic interventions have emerged as a promising and prospective strategy for AKI, overcoming traditional treatment dilemmas through alterations in size, shape, charge, and surface modifications. This Review succinctly summarizes the latest advancements in nanotherapeutic approaches for AKI, encompassing nanozymes, ROS scavenger nanomaterials, MSC-EVs, and nanomaterials loaded with antioxidants and inflammatory regulator. Following this, strategies aimed at enhancing biocompatibility and kidney targeting are introduced. Furthermore, a brief discussion on the current challenges and future prospects in this research field is presented, providing a comprehensive overview of the evolving landscape of nanotherapeutic interventions for AKI.

Exosomes are the smallest subset of extracellular signaling vesicles secreted by most cells with the ability to communicate with other tissues and cell types over long distances. Their use in regenerative medicine has gained tremendous momentum recently due to their ability to be utilized as therapeutic options for a wide array of diseases/conditions. Over 5000 publications are currently being published yearly on this topic, and this number is only expected to dramatically increase as novel therapeutic strategies continue to be developed. Today exosomes have been applied in numerous contexts including neurodegenerative disorders (Alzheimer's disease, central nervous system, depression, multiple sclerosis, Parkinson's disease, post-traumatic stress disorders, traumatic brain injury, peripheral nerve injury), damaged organs (heart, kidney, liver, stroke, myocardial infarctions, myocardial infarctions, ovaries), degenerative processes (atherosclerosis, diabetes, hematology disorders, musculoskeletal degeneration, osteoradionecrosis, respiratory disease), infectious diseases (COVID-19, hepatitis), regenerative procedures (antiaging, bone regeneration, cartilage/joint regeneration, osteoarthritis, cutaneous wounds, dental regeneration, dermatology/skin regeneration, erectile dysfunction, hair regrowth, intervertebral disc repair, spinal cord injury, vascular regeneration), and cancer therapy (breast, colorectal, gastric cancer and osteosarcomas), immune function (allergy, autoimmune disorders, immune regulation, inflammatory diseases, lupus, rheumatoid arthritis). This scoping review is a first of its kind aimed at summarizing the extensive regenerative potential of exosomes over a broad range of diseases and disorders.

Neonatal hypoxic-ischemic encephalopathy (HIE) is an abnormal neurological condition caused by hypoxic-ischemic damage during the perinatal period. Human placenta derived mesenchymal stem cells (hPMSCs) have been shown to have protective and reparative effects in various neurological diseases; however, the research on HIE is insufficient. This study aimed to establish a rat model of HIE and transplant hPMSCs through the lateral ventricle after hypoxic-ishcemic (HI) brain damage to observe its protective effects and mechanisms, with a focus on brain apoptosis compared among groups. Differentially expressed apoptosis-related proteins were screened using a rat cytokine array and subsequent verification. Neuropilin-1 (NRP-1) and Semaphorin 3A (Sema 3A) were selected for further investigation. Western blotting was used to quantify the expression of Sema 3A and the proteins related to PI3K/Akt/mTOR signaling pathway. Exogenous Sema 3A was added to evaluate the effects of Sema 3A/NRP-1 on hPMSCs following HI injury. hPMSCs transplantation ameliorated HI-induced pathological changes, reduced apoptosis, and improved long-term neurological prognosis. Furthermore, Sema 3A/NRP-1 was a key regulator in reducing HI-induced apoptosis after hPMSCs transplantation. hPMSCs inhibited the expression of Sema 3A/NRP-1 and activated the PI3K/Akt/mTOR signaling pathway. Additionally, exogenous Sema 3A abolished the protective effects of hPMSCs against HI. In conclusion, hPMSCs transplantation reduced apoptosis and improved long-term neurological prognosis after HI by downregulating Sema 3A/NRP-1 expression and activating the PI3K/Akt/mTOR signaling pathway.

The incidence and mortality rates of sepsis-induced acute kidney injury (SAKI) remain high, posing a substantial healthcare burden. Studies have implicated a connection between the development of SAKI and inflammation response, apoptosis, and autophagy. Moreover, evidence suggests that manipulating autophagy could potentially influence the prognosis of this condition. Notably, exosomes derived from bone mesenchymal stem cells (BMSCs-Exo) have exhibited promise in mitigating cellular damage by modulating pathways associated with inflammation, apoptosis, and autophagy. Thus, this study aims to investigate the influence of BMSCs-Exo on SAKI and the potential mechanisms that drive this impact.

The SAKI model was induced in HK-2 cells using lipopolysaccharide (LPS), while rats underwent cecal ligation and puncture (CLP) to simulate the condition. Cell viability was assessed using the CCK-8 kit, and kidney damage was evaluated through HE staining, blood urea nitrogen (BUN), and serum creatinine (SCr) measurements. Inflammatory-related RNAs and proteins were quantified via qPCR and ELISA, respectively. Apoptosis was determined through apoptosis-related protein levels, flow cytometry, and TUNEL staining. Western blot analysis was utilized to measure associated protein expressions.

In vivo, BMSCs-Exo ameliorated kidney injury in CLP-induced SAKI rats, reducing inflammatory cytokine production and apoptosis levels. Fluorescence microscope observed the absorption of BMSCs-Exo by renal cells following injection via tail vein. In the SAKI rat kidney tissue, there was an upregulation of LC3-II/LC3-I, p62, and phosphorylated AMP-activated protein kinase (p-AMPK) expressions, indicating blocked autophagic flux, while phosphorylated mammalian target of rapamycin (p-mTOR) expression was downregulated. However, BMSCs-Exo enhanced LC3-II/LC3-I and p-AMPK expression, concurrently reducing p62 and p-mTOR levels. In vitro, BMSCs-Exo enhanced cell viability in LPS-treated HK-2 cells, and exerted anti-inflammation and anti-apoptosis effects which were consistent with the results in vivo. Similarly, rapamycin (Rapa) exhibited a protective effect comparable to BMSCs-Exo, albeit partially abrogated by 3-methyladenine (3-MA).

BMSCs-Exo mitigate inflammation and apoptosis through autophagy in SAKI, offering a promising avenue for SAKI treatment.

Kidney transplantation (KT) is the best treatment for end-stage kidney disease. However, early diagnosis of graft injury remains challenging, mainly because of the lack of accurate and noninvasive diagnostic techniques. Improving graft outcomes is equally demanding, as is the development of innovative therapies. Many research efforts are focusing on extracellular vesicles, cellular particles free in each body fluid that have shown promising results as precise markers of damage and potential therapeutic targets in many diseases, including the renal field. In fact, through their receptors and cargo, they act in damage response and immune modulation. In transplantation, they may be used to determine organ quality and aging, the presence of delayed graft function, rejection, and many other transplant-related pathologies. Moreover, their low immunogenicity and safe profile make them ideal for drug delivery and the development of therapies to improve KT outcomes. In this review, we summarize current evidence about extracellular vesicles in KT, starting with their characteristics and major laboratory techniques for isolation and characterization. Then, we discuss their use as potential markers of damage and as therapeutic targets, discussing their promising use in clinical practice as a form of liquid biopsy.

Acute kidney injury (AKI) is a complex and heterogeneous disease with high incidence and mortality, posing a serious threat to human life and health. Usually, in clinical practice, AKI is caused by crush injury, nephrotoxin exposure, ischemia-reperfusion injury, or sepsis. Therefore, most AKI models for pharmacological experimentation are based on this. The current research promises to develop new biological therapies, including antibody therapy, non-antibody protein therapy, cell therapy, and RNA therapy, that could help mitigate the development of AKI. These approaches can promote renal repair and improve systemic hemodynamics after renal injury by reducing oxidative stress, inflammatory response, organelles damage, and cell death, or activating cytoprotective mechanisms. However, no candidate drugs for AKI prevention or treatment have been successfully translated from bench to bedside. This article summarizes the latest progress in AKI biotherapy, focusing on potential clinical targets and novel treatment strategies that merit further investigation in future pre-clinical and clinical studies.

Acute kidney injury (AKI) is a severe health problem associated with high morbidity and mortality rates. It currently lacks specific therapeutic strategies. This review focuses on the mechanisms underlying the actions of exosomes derived from different cell sources, including red blood cells, macrophages, monocytes, mesenchymal stem cells, and renal tubular cells, in AKI. We also investigate the effects of various exosome contents (such as miRNA, lncRNA, circRNA, mRNA, and proteins) in promoting renal tubular cell regeneration and angiogenesis, regulating autophagy, suppressing inflammatory responses and oxidative stress, and preventing fibrosis to facilitate AKI repair. Moreover, we highlight the interactions between macrophages and renal tubular cells through exosomes, which contribute to the progression of AKI. Additionally, exosomes and their contents show promise as potential biomarkers for diagnosing AKI. The engineering of exosomes has improved their clinical potential by enhancing isolation and enrichment, target delivery to injured renal tissues, and incorporating small molecular modifications for clinical use. However, further research is needed to better understand the specific mechanisms underlying exosome actions, their delivery pathways to renal tubular cells, and the application of multi-omics research in studying AKI.

Modulatory signaling pathway such as T cell immunoreceptor with Ig and ITIM domains (TIGIT), Cytotoxic T-Lymphocyte Associated Protein 4 (CTLA-4), P53 signaling and TIM (T-cell immunoglobin and mucin domain) are important in normal pregnancy and loss of their functions or dysregulation of related genes can lead to some disorders. Inflammation is a process by which your body's white blood cells and the things they make protect you from infection from outside invaders, such as bacteria and viruses. Some cellular and molecular signaling have been categorized to demonstrate the mechanism that protects tolerance to antigens. lncRNAs significantly impact physiological processes like immunity and metabolism, and are linked to tumors, cardiovascular diseases, nervous system disorders, and nephropathy.In this review article, we summarized recent studies about the role of TIGIT, CTLA-4, P53 and TIM regulatory molecules and reviewed dysregulation of these pathway in diseases.We will also talk about the role of lncRNAs and mesenchymal stem cells.

The possible beneficial effects of stem cell-derived EV on ischemia-reperfusion injury (IRI) in organ transplantation have been frequently investigated; however, the source of EV, as well as the methods of isolation and administration vary widely. We conducted a systematic review to summarize current pre-clinical evidence on stem cell-derived EV therapy for IRI of transplantable organs.

PubMed, Embase and Web of Science were searched from inception until August 19th, 2022, for studies on stem cell-derived EV therapy for IRI after heart, kidney, liver, pancreas, lung and intestine transplantation. The Systematic Review Center for Laboratory animal Experiments (SYRCLE) guidelines were followed to assess potential risk of bias.

The search yielded 4153 unique articles, of which 96 were retained. We identified 32 studies on cardiac IRI, 38 studies on renal IRI, 21 studies on liver IRI, four studies on lung IRI and one study on intestinal IRI. Most studies used rodent models of transient ischemic injury followed by in situ reperfusion. In all studies, EV therapy was associated with improved outcome albeit to a variable degree. EV-therapy reduced organ injury and improved function while displaying anti-inflammatory-, immunomodulatory- and pro-regenerative properties.

A multitude of animal studies support the potential of stem cell-derived EV-therapy to alleviate IRI after solid organ transplantation but suffer from low reporting quality and wide methodological variability. Future studies should focus on determining optimal stem cell source, dosage, and timing of treatment, as well as long-term efficacy in transplant models.

Kidney diseases are worldwide public health problems affecting millions of people. However, there are still limited therapeutic options against kidney diseases. Semaphorin 3A (SEMA3A) is a secreted and membrane-associated protein, which regulates diverse functions, including immune regulation, cell survival, migration and angiogenesis, thus involving in the several pathogeneses of diseases, including eyes and neurons, as well as kidneys. SEMA3A is expressed in podocytes and tubular cells in the normal adult kidney, and recent evidence has revealed that excess SEMA3A expression and the subsequent signaling pathway aggravate kidney injury in a variety of kidney diseases, including nephrotic syndrome, diabetic nephropathy, acute kidney injury, and chronic kidney disease. In addition, several reports have demonstrated that the inhibition of SEMA3A ameliorated kidney injury via a reduction in cell apoptosis, fibrosis and inflammation; thus, SEMA3A may be a potential therapeutic target for kidney diseases. In this review article, we summarized the current knowledge regarding the role of SEMA3A in kidney pathophysiology and their potential use in kidney diseases.

Osteoarthritis (OA) is a degenerative joint disease involving cartilage. Exosomes derived from Mesenchymal stem cells (MSCs) therapy improves articular cartilage repair, but subcutaneous fat (SC) stromal cells derived exosomes (MSCsSC-Exos), especially engineering MSCsSC-Exos for drug delivery have been rarely reported in OA therapy. This objective of this study was to clarify the underlying mechanism of MSCsSC-Exos on cartilage repair and therapy of engineering MSCsSC-Exos for drug delivery in OA. MSCsSC-Exos could ameliorate the pathological severity degree of cartilage via miR-199a-3p, a novel molecular highly enriched in MSCsSC-Exos, which could mediate the mTOR-autophagy pathway in OA rat model. Intra-articular injection of antagomiR-199a-3p dramatically attenuated the protective effect of MSCsSC-Exos-mediated on articular cartilage in vivo. Furthermore, to achieve the superior therapeutic effects of MSCsSC-Exos on injured cartilage, engineering exosomes derived from MSCsSC as the chondrocyte-targeting miR-199a-3p delivery vehicles were investigated in vitro and in vivo. The chondrocyte-binding peptide (CAP) binding MSCsSC-Exos could particularly deliver miR-199a-3p into the chondrocytes in vitro and into deep articular tissues in vivo, then exert the excellent protective effect on injured cartilage in DMM-induced OA mice. As it is feasible to obtain human subcutaneous fat from healthy donors by liposuction operation in clinic, meanwhile engineering MSCsSC-Exos to realize targeted delivery of miR-199a-3p into chondrocytes exerted excellent therapeutic effects in OA animal model in vivo. Through combining MSCsSC-Exos therapy and miRNA therapy via an engineering approach, we develop an efficient MSCsSC-Exos-based strategy for OA therapy and promote the application of targeted-MSCsSC-Exos for drug delivery in the future.

Acute kidney injury (AKI) is a clinical syndrome where a rapid decrease in kidney function and/or urine output is observed, which may result in the imbalance of water, electrolytes and acid base. It is associated with poor prognosis and prolonged hospitalization. Therefore, an early diagnosis and treatment to avoid the severe AKI stage are important. While several biomarkers, such as urinary L-FABP and NGAL, can be clinically useful, there is still no gold standard for the early detection of AKI and there are limited therapeutic options against AKI. miRNAs are non-coding and single-stranded RNAs that silence their target genes in the post-transcriptional process and are involved in a wide range of biological processes. Recent accumulated evidence has revealed that miRNAs may be potential biomarkers and therapeutic targets for AKI. In this review article, we summarize the current knowledge about miRNAs as promising biomarkers and potential therapeutic targets for AKI, as well as the challenges in their clinical use.

Renal ischemia-reperfusion injury (RIRI) is a complex disorder characterized by both intrinsic damage to renal tubular epithelial cells and extrinsic inflammation mediated by cytokines and immune cells. Unfortunately, there is no cure for this devastating condition. Extracellular vesicles (EVs) are nanosized membrane-bound vesicles secreted by various cell types that can transfer bioactive molecules to target cells and modulate their function. EVs have emerged as promising candidates for cell-free therapy of RIRI, owing to their ability to cross biological barriers and deliver protective signals to injured renal cells. In this review, we provide an overview of EVs, focusing on their functional role in RIRI and the signaling messengers responsible for EV-mediated crosstalk between various cell types in renal tissue. We also discuss the renoprotective role of EVs and their use as therapeutic agents for RIRI, highlighting the advantages and challenges encountered in the therapeutic application of EVs in renal disease.

Post-transcriptional regulation by non-coding RNAs (ncRNAs) can modulate the expression of genes involved in kidney physiology and disease. A large variety of ncRNA species exist, including microRNAs, long non-coding RNAs, piwi-interacting RNAs, small nucleolar RNAs, circular RNAs and yRNAs. Despite early assumptions that some of these species may exist as by-products of cell or tissue injury, a growing body of literature suggests that these ncRNAs are functional and participate in a variety of processes. Although they function intracellularly, ncRNAs are also present in the circulation, where they are carried by extracellular vesicles, ribonucleoprotein complexes or lipoprotein complexes such as HDL. These systemic, circulating ncRNAs are derived from specific cell types and can be directly transferred to a variety of cells, including endothelial cells of the vasculature and virtually any cell type in the kidney, thereby affecting the function of the host cell and/or its response to injury. Moreover, chronic kidney disease itself, as well as injury states associated with transplantation and allograft dysfunction, is associated with a shift in the distribution of circulating ncRNAs. These findings may provide opportunities for the identification of biomarkers with which to monitor disease progression and/or the development of therapeutic interventions.

Kidney disease is a growing public health problem worldwide, including both acute and chronic forms. Existing therapies for kidney disease target various pathogenic mechanisms; however, these therapies only slow down the progression of the disease rather than offering a cure. One of the potential and emerging approaches for the treatment of kidney disease is mesenchymal stromal/stem cell (MSC) therapy, shown to have beneficial effects in preclinical studies. In addition, extracellular vesicles (EVs) released by MSCs became a potent cell-free therapy option in various preclinical models of kidney disease due to their regenerative, anti-inflammatory, and immunomodulatory properties. However, there are scarce clinical data available regarding the use of MSC-EVs in kidney pathologies. This review article provides an outline of the renoprotective effects of MSC-EVs in different preclinical models of kidney disease. It offers a comprehensive analysis of possible mechanisms of action of MSC-EVs with an emphasis on kidney disease. Finally, on the journey toward the implementation of MSC-EVs into clinical practice, we highlight the need to establish standardized methods for the characterization of an EV-based product and investigate the adequate dosing, safety, and efficacy of MSC-EVs application, as well as the development of suitable potency assays.

Renal pathophysiology is a multifactorial process involving different kidney structures. Acute kidney injury (AKI) is a clinical condition characterized by tubular necrosis and glomerular hyperfiltration. The maladaptive repair after AKI predisposes to the onset of chronic kidney diseases (CKD). CKD is a progressive and irreversible loss of kidney function, characterized by fibrosis that could lead to end stage renal disease. In this review we provide a comprehensive overview of the most recent scientific publications analyzing the therapeutic potential of Extracellular Vesicles (EV)-based treatments in different animal models of AKI and CKD. EVs from multiple sources act as paracrine effectors involved in cell-cell communication with pro-generative and low immunogenic properties. They represent innovative and promising natural drug delivery vehicles used to treat experimental acute and chronic kidney diseases. Differently from synthetic systems, EVs can cross biological barriers and deliver biomolecules to the recipient cells inducing a physiological response. Moreover, new methods for improving the EVs as carriers have been introduced, such as the engineering of the cargo, the modification of the proteins on the external membrane, or the pre-conditioning of the cell of origin. The new nano-medicine approaches based on bioengineered EVs are an attempt to enhance their drug delivery capacity for potential clinical applications.

Renal ischemia-reperfusion (I/R) injury is a leading cause of acute kidney injury (AKI), with high mortality. Recent studies have reported that human umbilical cord mesenchymal stem cells (HucMSCs) play an important role in repairing organ and tissue injuries because of their unique characteristics. However, the potential of HucMSC extracellular vesicles (HucMSC-EVs) to promote the repair of renal tubular cells remains to be explored. This study found that HucMSC-EVs derived from HucMSCs played a protective role and were associated with kidney I/R injury. We found that miR-148b-3p in HucMSC-EVs had a protective effect against kidney I/R injury. HK-2 cells overexpressing miR-148b-3p were protected against I/R injury by inhibiting apoptosis. Next, the target mRNA of miR-148b-3p was predicted online, and the target mRNA, pyruvate dehydrogenase kinase 4 (PDK4), was identified and verified using dual luciferase. We discovered that I/R injury significantly increased endoplasmic reticulum (ER) stress, whereas siR-PDK4 inhibited these effects and protected against I/R injury. Interestingly, after administrating HucMSC-EVs to HK-2 cells, PDK4 expression and ER stress induced by I/R injury were significantly inhibited. HK-2 ingested miR-148b-3p from HucMSC-EVs, and its ER induced by I/R injury was significantly deregulated. This study suggests that HucMSC-EVs protect kidneys from I/R injury during the early I/R stage. These results suggest a new mechanism for HucMSC-EVs in treating AKI and provide a new treatment strategy for I/R injury.

Extracellular vesicles are lipid bilayer-delimited nanoparticles excreted into the extracellular space by all cells. They carry a cargo rich in proteins, lipids and DNA, as well as a full complement of RNA species, which they deliver to recipient cells to induce downstream signalling, and they play a key role in many physiological and pathological processes. There is evidence that native and hybrid EVs may be used as effective drug delivery systems, with their intrinsic ability to protect and deliver a functional cargo by utilising endogenous cellular mechanisms making them attractive as therapeutics. Organ transplantation is the gold standard for treatment for suitable patients with end-stage organ failure. However, significant challenges still remain in organ transplantation; prevention of graft rejection requires heavy immunosuppression and the lack of donor organs results in a failure to meet demand, as manifested by growing waiting lists. Pre-clinical studies have demonstrated the ability of EVs to prevent rejection in transplantation and mitigate ischemia reperfusion injury in several disease models. The findings of this work have made clinical translation of EVs possible, with several clinical trials actively recruiting patients. However, there is much to be uncovered, and it is essential to understand the mechanisms behind the therapeutic benefits of EVs. Machine perfusion of isolated organs provides an unparalleled platform for the investigation of EV biology and the testing of the pharmacokinetic and pharmacodynamic properties of EVs. This review classifies EVs and their biogenesis routes, and discusses the isolation and characterisation methods adopted by the international EV research community, before delving into what is known about EVs as drug delivery systems and why organ transplantation represents an ideal platform for their development as drug delivery systems.