The Nephroprotective Properties of Extracellular Vesicles in Experimental Models of Chronic Kidney Disease: a Systematic Review

Microneedle-Delivered PDA@Exo for Multifaceted Osteoarthritis Treatment via PI3K-Akt-mTOR Pathway

Osteoarthritis (OA) is marked by cartilage deterioration, subchondral bone changes, and an inflammatory microenvironment. The study introduces the Microneedle-Delivered Polydopamine-Exosome (PDA@Exo MN), a therapeutic that not only preserves cartilage and promotes bone regeneration but also improves localized drug delivery through enhanced penetration capabilities. PDA@Exo MN shows strong reactive oxygen species (ROS) scavenging abilities and high biocompatibility, fostering osteogenesis and balancing anabolic and catabolic processes in cartilage. It directs macrophage polarization from M0 to the anti-inflammatory M2 phenotype. RNA sequencing of treated chondrocytes demonstrates restored cellular function and activated antioxidant responses, with modulated inflammatory pathways. The PI3K-AKT-mTOR pathway's activation, essential for PDA@Exo's effects, is confirmed via bioinformatics and Western blot. In vivo assessments robustly validate that PDA@Exo MN prevents cartilage degradation and OA progression, supported by histological assessments and micro-CT analysis, highlighting its disease-modifying impact. The excellent biocompatibility of PDA@Exo MN, verified through histological (H&E) and blood tests showing no organ damage, underscores its safety and efficacy for OA therapy, making it a novel and multifunctional nanomedical approach in orthopedics, characterized by organ-friendliness and biosecurity.

Mesenchymal stem cell transplantation: Systematic review, meta-analysis and clinical applications for acute kidney injury and chronic kidney disease in dogs and cats

Chronic kidney disease (CKD) and acute kidney injury (AKI) are diseases which affect the urinary tract characterized by the loss of renal function. Their therapy requires different therapeutic goals. Mesenchymal stem cells (MSC) transplantation has spread over the years as a treatment for many diseases. In the urinary tract, studies report anti-inflammatory, antiapoptotic, antifibrotic, antioxidant and angiogenic effects. This work reports the results of a meta-analysis about the effects of the MSC application in serum levels of creatinine in dogs and cats with AKI and CKD. The work followed PRISMA guidelines. Data were screened, selected, and extracted with characteristics about the studies. The kinds of injury were classified according to their identification and the risk of bias was calculated by the system SYRCLE. The results of each group were combined by the inverse variance method. The heterogeneity was evaluated by the I2 test. For the mean of creatinine, a meta-analysis was performed according to the study group and number of applications and separately for the control and treatment groups according to the kind of injury, dose, application route, and moment. At all, 4742 articles were found. Of these, 40 were selected for eligibility, 16 underwent qualitative analysis and 9 to the quantitative. The results denote advantage to the group treated with MSC over placebo. A statistical difference was observed both in combined analysis and in the subgroups division. However, a high heterogeneity was found, which indicates considerable variation between the studies, which indicates caution in generalize the results.

Understanding molecular characteristics of extracellular vesicles derived from different types of mesenchymal stem cells for therapeutic translation

Mesenchymal stem cells (MSCs) have been studied for decades as candidates for cellular therapy, and their secretome, including secreted extracellular vesicles (EVs), has been identified to contribute significantly to regenerative and reparative functions. Emerging evidence has suggested that MSC-EVs alone, could be used as therapeutics that emulate the biological function of MSCs. However, just as with MSCs, MSC-EVs have been shown to vary in composition, depending on the tissue source of the MSCs as well as the protocols employed in culturing the MSCs and obtaining the EVs. Therefore, the importance of careful choice of cell sources and culture environments is receiving increasing attention. Many factors contribute to the therapeutic potential of MSC-EVs, including the source tissue, isolation technique, and culturing conditions. This review illustrates the molecular landscape of EVs derived from different types of MSC cells along with culture strategies. A thorough analysis of publicly available omic datasets was performed to advance the precision understanding of MSC-EVs with unique tissue source-dependent molecular characteristics. The tissue-specific protein and miRNA-driven Reactome ontology analysis was used to reveal distinct patterns of top Reactome ontology pathways across adipose, bone marrow, and umbilical MSC-EVs. Moreover, a meta-analysis assisted by an AI technique was used to analyze the published literature, providing insights into the therapeutic translation of MSC-EVs based on their source tissues.

Obstructive nephropathy and molecular pathophysiology of renal interstitial fibrosis

The kidneys play a key role in maintaining total body homeostasis. The complexity of this task is reflected in the unique architecture of the organ. Ureteral obstruction greatly affects renal physiology by altering hemodynamics, changing glomerular filtration and renal metabolism, and inducing architectural malformations of the kidney parenchyma, most importantly renal fibrosis. Persisting pathological changes lead to chronic kidney disease, which currently affects ∼10% of the global population and is one of the major causes of death worldwide. Studies on the consequences of ureteral obstruction date back to the 1800s. Even today, experimental unilateral ureteral obstruction (UUO) remains the standard model for tubulointerstitial fibrosis. However, the model has certain limitations when it comes to studying tubular injury and repair, as well as a limited potential for human translation. Nevertheless, ureteral obstruction has provided the scientific community with a wealth of knowledge on renal (patho)physiology. With the introduction of advanced omics techniques, the classical UUO model has remained relevant to this day and has been instrumental in understanding renal fibrosis at the molecular, genomic, and cellular levels. This review details key concepts and recent advances in the understanding of obstructive nephropathy, highlighting the pathophysiological hallmarks responsible for the functional and architectural changes induced by ureteral obstruction, with a special emphasis on renal fibrosis.

Effect of extracellular vesicles derived from induced pluripotent stem cells on mesangial cells underwent a model of fibrosis in vitro

The fibrogenic process plays a significant pathophysiological role in the progression of chronic kidney disease. Inhibition of the renin-angiotensin system (RAS) is one strategy to delay disease progression but does not reverse established fibrosis. In this context, induced pluripotent stem cells (iPSCs) have been considered an alternative due to their regenerative potential. iPSCs exert their effects through paracrine signaling, which releases specific biomolecules into the extracellular environment, either directly or within extracellular vesicle (EVs), that can reach target cells. This study aims to evaluate the potential beneficial effects of iPSC-derived EVs (EV-iPSCs) in an in vitro model of fibrosis using mouse mesangial cells (MMCs) stimulated with TGF-β. EV-iPSCs were obtained by differentially ultracentrifuging iPSCs culture medium. MMCs were stimulated with 5 ng/mL of TGF-β and simultaneously treated with or without EV-iPSCs for 24 h. Markers of inflammation, fibrosis, and RAS components were assessed using RT-PCR, western blotting, and immunofluorescence. Under TGF-β stimulus, MMCs exhibited increased expression of inflammation markers, RAS components, and fibrosis. However, these changes were mitigated in the presence of EV-iPSCs. EV-iPSCs effectively reduced inflammation, RAS activation, and fibrogenesis in this fibrosis model involving mesangial cells, suggesting their potential as a strategy to reduce glomerular sclerosis.

Stem cell- derived extracellular vesicles as new tools in regenerative medicine - Immunomodulatory role and future perspectives

In the last few decades, the practical use of stem cells (SCs) in the clinic has attracted significant attention in the regenerative medicine due to the ability of these cells to proliferate and differentiate into other cell types. However, recent findings have demonstrated that the therapeutic capacity of SCs may also be mediated by their ability to secrete biologically active factors, including extracellular vesicles (EVs). Such submicron circular membrane-enveloped vesicles may be released from the cell surface and harbour bioactive cargo in the form of proteins, lipids, mRNA, miRNA, and other regulatory factors. Notably, growing evidence has indicated that EVs may transfer their bioactive content into recipient cells and greatly modulate their functional fate. Thus, they have been recently envisioned as a new class of paracrine factors in cell-to-cell communication. Importantly, EVs may modulate the activity of immune system, playing an important role in the regulation of inflammation, exhibiting broad spectrum of the immunomodulatory activity that promotes the transition from pro-inflammatory to pro-regenerative environment in the site of tissue injury. Consequently, growing interest is placed on attempts to utilize EVs in clinical applications of inflammatory-related dysfunctions as potential next-generation therapeutic factors, alternative to cell-based approaches. In this review we will discuss the current knowledge on the biological properties of SC-derived EVs, with special focus on their role in the regulation of inflammatory response. We will also address recent findings on the immunomodulatory and pro-regenerative activity of EVs in several disease models, including in vitro and in vivo preclinical, as well as clinical studies. Finally, we will highlight the current perspectives and future challenges of emerging EV-based therapeutic strategies of inflammation-related diseases treatment.

Extracellular Vesicles as Theranostic Tools in Kidney Disease

Extracellular vesicles are important vectors for cell-cell communication and show potential value for diagnosis and treatment of kidney diseases. The pathologic diagnosis of kidney diseases relies on kidney biopsy, whereas collection of extracellular vesicles from urine or circulating blood may constitute a less invasive diagnostic tool. In particular, urinary extracellular vesicles released mainly from resident kidney cells might provide an alternative tool for detection of kidney injury. Because extracellular vesicles mirror many features of their parent cells, cargoes of several populations of urinary extracellular vesicles are promising biomarkers for disease processes, like diabetic kidney disease, kidney transplant, and lupus nephritis. Contrarily, extracellular vesicles derived from reparative cells, such as mesenchymal stem cells, tubular epithelial progenitor cells, and human umbilical cord blood represent promising regenerative tools for treatment of kidney diseases. Furthermore, induced pluripotent stem cells-derived and engineered extracellular vesicles are being developed for specific applications for the kidney. Nevertheless, some assumptions regarding the specificity and immunogenicity of extracellular vesicles remain to be established. This review focuses on the utility of extracellular vesicles as therapeutic and diagnostic (theranostic) tools in kidney diseases and future directions for studies.

Exosomes Derived from BM-MSCs Mitigate the Development of Chronic Kidney Damage Post-Menopause via Interfering with Fibrosis and Apoptosis

The rate of chronic kidney disease (CKD) is increasing globally, and it is caused by continuous damage to kidney tissue. With time the renal damage becomes irreversible, leading to CKD development. In females, post-menopause lack of estrogen supply has been described as a risk factor for CKD development, and studies targeting post-menopause CKD are scarce. In the present study, we used exosomes isolated from bone marrow mesenchymal stem/stromal cells (BM-MSCs) to test their therapeutic potential against the development of CKD. At first, the menopause model was achieved by surgical bilateral ovariectomy in female albino rats. After that, 100 µg of exosomes was given to ovariectomized rats, and the study continued for 2 months. Changes in urine volume, urine protein content, kidney function biochemical parameters (creatinine and BUN), kidney antioxidant parameters (SOD, GPx and CAT), histological changes, immunohistochemical levels of caspase 3, and the gene expression of NGAL (related to kidney damage), TGFβ1 and αSMA (related to fibrosis and EMT), and caspase 3 (related to apoptosis) were studied. After the ovariectomy, the occurrence of CKD was confirmed in the rats by the drastic reduction of serum estrogen and progesterone levels, reduced urine output, increased urinary protein excretion, elevated serum creatinine and BUN, reduced GPx SOD, and CAT in kidney tissue, degenerative and fibrotic lesions in the histopathological examination, higher immunohistochemical expression of caspase 3 and increased expression of all studied genes. After exosomes administration, the entire chronic inflammatory picture in the kidney was corrected, and a near-normal kidney structure and function were attained. This study shows for the first time that BM-MSCs exosomes are potent for reducing apoptosis and fibrosis levels and, thus, can reduce the chronic damage of the kidneys in females that are in their menopause period. Therefore, MSCs-derived exosomes should be considered a valuable therapy for preserving postmenopausal kidney structure and function and, subsequently, could improve the quality of females’ life during menopause.

Exploring New Kingdoms: The Role of Extracellular Vesicles in Oxi-Inflamm-Aging Related to Cardiorenal Syndrome

The incidence of age associated chronic diseases has increased in recent years. Although several diverse causes produce these phenomena, abundant evidence shows that oxidative stress plays a central role. In recent years, numerous studies have focused on elucidating the role of oxidative stress in the development and progression of both aging and chronic diseases, opening the door to the discovery of new underlying mechanisms and signaling pathways. Among them, senolytics and senomorphics, and extracellular vesicles offer new therapeutic strategies to slow the development of aging and its associated chronic diseases by decreasing oxidative stress. In this review, we aim to discuss the role of extracellular vesicles in human cardiorenal syndrome development and their possible role as biomarkers, targets, or vehicles of drugs to treat this syndrome.

Klotho and Mesenchymal Stem Cells: A Review on Cell and Gene Therapy for Chronic Kidney Disease and Acute Kidney Disease

Chronic kidney disease (CKD) and acute kidney injury (AKI) are public health problems, and their prevalence rates have increased with the aging of the population. They are associated with the presence of comorbidities, in particular diabetes mellitus and hypertension, resulting in a high financial burden for the health system. Studies have indicated Klotho as a promising therapeutic approach for these conditions. Klotho reduces inflammation, oxidative stress and fibrosis and counter-regulates the renin-angiotensin-aldosterone system. In CKD and AKI, Klotho expression is downregulated from early stages and correlates with disease progression. Therefore, the restoration of its levels, through exogenous or endogenous pathways, has renoprotective effects. An important strategy for administering Klotho is through mesenchymal stem cells (MSCs). In summary, this review comprises in vitro and in vivo studies on the therapeutic potential of Klotho for the treatment of CKD and AKI through the administration of MSCs.