Adipose mesenchymal stem cell-derived extracellular vesicles containing microRNA-26a-5p target TLR4 and protect against diabetic nephropathy

Frontier role of extracellular vesicles in kidney disease

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.

How Stem and Progenitor Cells Can Affect Renal Diseases

Stem and progenitor cells have been observed to contribute to regenerative processes in acute renal failure and chronic kidney disease. Recent research has delved into the intricate mechanisms by which stem and progenitor cells exert their influence on kidney diseases. Understanding how these cells integrate with the existing renal architecture and their response to injury could pave the way for innovative treatment strategies aimed at promoting kidney repair and regeneration. Overall, the role of stem and progenitor cells in kidney diseases is multifaceted, with their ability to contribute to tissue regeneration, immune modulation, and the maintenance of renal homeostasis. Here, we review the studies that we have available today about the involvement of stem and progenitor cells both in regenerative therapies and in the causes of renal diseases, as well as in natural healing mechanisms, taking into account the main kidney disorders, such as IgA nephropathy, lupus nephritis, diabetic nephropathy, C3 glomerulopathy, focal segmental glomerulosclerosis, idiopathic membranous nephropathy, anti-glomerular basement membrane glomerulonephritis, and ANCA-associated crescentic glomerulonephritis. Moreover, based on the comprehensive data available in the framework of the specific kidney diseases on stem cells and renal progenitors, we hypothesize a possible role of adult renal progenitors in exacerbating or recovering the illness.

Urine-derived podocytes from steroid resistant nephrotic syndrome patients as a model for renal-progenitor derived extracellular vesicles effect and drug screening

BACKGROUND

Personalized disease models are crucial for evaluating how diseased cells respond to treatments, especially in case of innovative biological therapeutics. Extracellular vesicles (EVs), nanosized vesicles released by cells for intercellular communication, have gained therapeutic interest due to their ability to reprogram target cells. We here utilized urinary podocytes obtained from children affected by steroid-resistant nephrotic syndrome with characterized genetic mutations as a model to test the therapeutic potential of EVs derived from kidney progenitor cells (nKPCs).

METHODS

EVs were isolated from nKPCs derived from the urine of a preterm neonate. Three lines of urinary podocytes obtained from nephrotic patients' urine and a line of Alport syndrome patient podocytes were characterized and used to assess albumin permeability in response to nKPC-EVs or various drugs. RNA sequencing was conducted to identify commonly modulated pathways after nKPC-EV treatment. siRNA transfection was used to demonstrate the involvement of SUMO1 and SENP2 in the modulation of permeability.

RESULTS

Treatment with the nKPC-EVs significantly reduced permeability across all the steroid-resistant patients-derived and Alport syndrome-derived podocytes. At variance, podocytes appeared unresponsive to standard pharmacological treatments, with the exception of one line, in alignment with the patient's clinical response at 48 months. By RNA sequencing, only two genes were commonly upregulated in nKPC-EV-treated genetically altered podocytes: small ubiquitin-related modifier 1 (SUMO1) and Sentrin-specific protease 2 (SENP2). SUMO1 and SENP2 downregulation increased podocyte permeability confirming the role of the SUMOylation pathway.

CONCLUSIONS

nKPCs emerge as a promising non-invasive source of EVs with potential therapeutic effects on podocytes with genetic dysfunction, through modulation of SUMOylation, an important pathway for the stability of podocyte slit diaphragm proteins. Our findings also suggest the feasibility of developing a non-invasive in vitro model for screening regenerative compounds on patient-derived podocytes.

LncRNA H19 deficiency protects against the structural damage of glomerular endothelium in diabetic nephropathy via Akt/eNOS pathway

Objective: This study aimed to investigate the functions of lncRNA H19 on glomerular endothelial structural damage of diabetic nephropathy (DN).Materials and Methods: Rats were fed a high sugar and fat high feed die, and intraperitoneally administrated with streptozotocin (30 mg/kg) to induce DN model. Meanwile, rat glomerular endothelial cells (rGEnCs) were treated with high a level of glucose （HG, 30 mM glucose）to induce structural damage.Results: Our results showed that H19 level was drastically increased in diabetic glomeruli and high-glucose (HG)-stimulated rat glomerular endothelial cells (rGEnCs). Deficiency of H19 ameliorated microalbumin, creatinine, BUN, and histopathological alterations in diabetic rats. In addition, H19 deficiency significantly attenuated the damage of endothelial structure by upregulating the expression of junction proteins ZO-1 and Occludin, glycolcalyx protein Syndecan-1, and endothelial activation marker sVCAM-1 and sICAM-1 in diabetic rats. The in vitro results also showed that H19-siRNA alleviated glycocalyx shedding, tight junctions damage, and endothelial activation in HG-stimulated rGEnCs. Moreover, H19 deficiency significantly enhanced the expression of p-Akt and p-eNOS and NO concentration in vitro and in vivo. Pre-treatment with Akt inhibitor LY294002 abrogated these favourable effects mediated by H19 deficiency.Discussion and Conclusion: These results indicate that H19 deficiency could mitigate the structural damage of glomerular endothelium in DN via activating Akt/eNOS pathway.

Role of Extracellular Vesicle-Derived Noncoding RNAs in Diabetic Kidney Disease

Background

Diabetic kidney disease (DKD), a metabolism-related syndrome characterized by abnormal glomerular filtration rate, proteinuria, and renal microangiopathy, is one of the most common forms of chronic kidney disease, whereas extracellular vesicles (EVs) have been recently evidenced as a novel cell communication player in DKD occurrence and progress via releasing various bioactive molecules, including proteins, lipids, and especially RNA, among which noncoding RNAs (including miRNAs, lncRNAs, and circRNAs) are the major regulators. However, the functional relevance of EV-derived ncRNAs in DKD is to be elucidated.

Summary

Studies have reported that EV-derived ncRNAs regulate gene expression via a diverse range of regulatory mechanisms, contributing to diverse phenotypes related to DKD progression. Furthermore, there are already many potential clinical diagnostic and therapeutic studies based on these ncRNAs, which can be expected to have potential applications in clinical practice for EV-derived ncRNAs.

Key Messages

In the current review, we summarized the mechanistic role of EVs in DKD according to biological function classifications, including inflammation and oxidative stress, epithelial-mesenchymal transition, cell death, and extracellular matrix deposition. In addition, we comprehensively discussed the potential applications of EV-derived ncRNAs as diagnostic biomarkers and therapeutic targets in DKD.

Recent advances in the use of extracellular vesicles from adipose-derived stem cells for regenerative medical therapeutics

Adipose-derived stem cells (ADSCs) are a subset of mesenchymal stem cells (MSCs) isolated from adipose tissue. They possess remarkable properties, including multipotency, self-renewal, and easy clinical availability. ADSCs are also capable of promoting tissue regeneration through the secretion of various cytokines, factors, and extracellular vesicles (EVs). ADSC-derived EVs (ADSC-EVs) act as intercellular signaling mediators that encapsulate a range of biomolecules. These EVs have been found to mediate the therapeutic activities of donor cells by promoting the proliferation and migration of effector cells, facilitating angiogenesis, modulating immunity, and performing other specific functions in different tissues. Compared to the donor cells themselves, ADSC-EVs offer advantages such as fewer safety concerns and more convenient transportation and storage for clinical application. As a result, these EVs have received significant attention as cell-free therapeutic agents with potential future application in regenerative medicine. In this review, we focus on recent research progress regarding regenerative medical use of ADSC-EVs across various medical conditions, including wound healing, chronic limb ischemia, angiogenesis, myocardial infarction, diabetic nephropathy, fat graft survival, bone regeneration, cartilage regeneration, tendinopathy and tendon healing, peripheral nerve regeneration, and acute lung injury, among others. We also discuss the underlying mechanisms responsible for inducing these therapeutic effects. We believe that deciphering the biological properties, therapeutic effects, and underlying mechanisms associated with ADSC-EVs will provide a foundation for developing a novel therapeutic approach in regenerative medicine.

Therapeutic potential: The role of mesenchymal stem cells from diverse sources and their derived exosomes in diabetic nephropathy

Diabetic nephropathy (DN) is one of the most common microvascular complications in diabetic patients, with its incidence continuously increasing in recent years. DN causes renal tissue damage and functional decline, expedites the aging process of the kidneys, and may ultimately progress leading to end-stage renal disease, severely impacting the patient's quality of life and prognosis. Mesenchymal stem cells (MSCs) are highly valued for their multipotent differentiation, paracrine functions, immunomodulatory effects, and capacity for tissue repair. Particularly, exosomes (Exo) derived from MSCs (MSCs-Exo) are rich in bioactive molecules and facilitate intercellular communication, participating in various physiological and pathological processes. MSCs and MSCs-Exo, in particular, have been demonstrated to have therapeutic effects in DN treatment research by encouraging tissue repair, fibrosis inhibition, and inflammation reduction. Research has shown that MSCs and MSCs-Exo have therapeutic effects in DN treatment by promoting tissue repair, inhibiting fibrosis, and reducing inflammation. Recent studies underscore the potential of MSCs and MSCs-Exo, highlighting their broad applicability in DN treatment. This review aims to provide a comprehensive summary of the scientific developments in treating DN using MSCs and MSCs-Exo from diverse sources, while also exploring their future therapeutic possibilities in detail.

Stem Cell-Derived Exosomal MicroRNAs as Novel Potential Approach for Multiple Sclerosis Treatment

Multiple Sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) characterized by inflammation and demyelination of CNS neurons. Up to now, there are many therapeutic strategies for MS but they are only being able to reduce progression of diseases and have not got any effect on repair and remyelination. Stem cell therapy is an appropriate method for regeneration but has limitations and problems. So recently, researches were used of exosomes that facilitate intercellular communication and transfer cell-to-cell biological information. MicroRNAs (miRNAs) are a class of short non-coding RNAs that we can used to their dysregulation in order to diseases diagnosis. The miRNAs of microvesicles obtained stem cells may change the fate of transplanted cells based on received signals of injured regions. The miRNAs existing in MSCs may be displayed the cell type and their biological activities. Current studies show also that the miRNAs create communication between stem cells and tissue-injured cells. In the present review, firstly we discuss the role of miRNAs dysregulation in MS patients and miRNAs expression by stem cells. Finally, in this study was confirmed the relationship of microRNAs involved in MS and miRNAs expressed by stem cells and interaction between them in order to find appropriate treatment methods in future for limit to disability progression.

Goat milk exosomal microRNAs alleviate LPS-induced intestinal inflammation in mice

Intestinal inflammation is a common digestive system disease. Milk-derived exosomes can participate in intercellular communication and transport a variety of bioactive components, and the microRNAs (miRNAs) they carry play important roles in a variety of biological processes in the body. At present, the preventive effect and mechanism of action of goat milk exosomes and their derived miRNAs on intestinal inflammation are still unclear. In this study, the protective effect of goat milk exosomes on LPS-induced intestinal inflammation was investigated using mouse intestinal inflammation model and IEC-6 cell inflammation model. Small RNA sequencing was used to analyze the miRNA expression profile of goat milk exosomes. In this study, C-Exo and M-Exo alleviated intestinal inflammation by reducing the LPS-induced release of proinflammatory cytokines, inhibiting the increase in the NLRP3 protein and the activation of the TLR4/NFκB signaling pathway. C-Exo has a more significant inhibitory effect on them, and better therapeutic efficacy than M-Exo. Notably, the target genes of miRNAs in C-Exo and M-Exo were significantly enriched in immune-related pathways. Furthermore, their derived miR-26a-5p and miR-30a-5p were found to ameliorate the IEC-6 inflammatory response. These findings suggest that miRNAs in goat milk exosomes have the potential to attenuate LPS-induced intestinal inflammation.

Exosomes derived from mesenchymal stem cells in diabetes and diabetic complications

Diabetes, a group of metabolic disorders, constitutes an important global health problem. Diabetes and its complications place a heavy financial strain on both patients and the global healthcare establishment. The lack of effective treatments contributes to this pessimistic situation and negative outlook. Exosomes released from mesenchymal stromal cells (MSCs) have emerged as the most likely new breakthrough and advancement in treating of diabetes and diabetes-associated complication due to its capacity of intercellular communication, modulating the local microenvironment, and regulating cellular processes. In the present review, we briefly outlined the properties of MSCs-derived exosomes, provided a thorough summary of their biological functions and potential uses in diabetes and its related complications.

The Inhibition of Fibrosis and Inflammation in Obstructive Kidney Injury via the miR-122-5p/SOX2 Axis Using USC-Exos

Background: Fibrosis and inflammation due to ureteropelvic junction obstruction substantially contributes to poor renal function. Urine-derived stem-cell-derived exosomes (USC-Exos) have therapeutic effects through paracrine. Methods: In vitro, the effects of USC-Exos on the biological functions of HK-2 and human umbilical vein endothelial cells were tested. Cell inflammation and fibrosis were induced by transforming growth factor-β1 and interleukin-1β, and their anti-inflammatory and antifibrotic effects were observed after exogenous addition of USC-Exos. Through high-throughput sequencing of microRNA in USC-Exos, the pathways and key microRNAs were selected. Then, the antifibrotic and anti-inflammatory effects of exosomal miR-122-5p and target genes were verified. The role of the miR-122-5p/SOX2 axis in anti-inflammatory and antifibrotic effects was verified. In vivo, a rabbit model of partial unilateral ureteral obstruction (PUUO) was established. Magnetic resonance imaging recorded the volume of the renal pelvis after modeling, and renal tissue was pathologically analyzed. Results: We examined the role of USC-Exos and their miR-122-5p content in obstructive kidney injury. These Exos exhibit antifibrotic and anti-inflammatory activities. SOX2 is the hub gene in PUUO and negatively related to renal function. We confirmed the binding relationship between miR-122-5p and SOX2. The anti-inflammatory and antifibrotic effects of miR-122-5p were inhibited, indicating that miR-122-5p has anti-inflammatory and antifibrotic effects by inhibiting SOX2 expression. In vivo, the PUUO group showed typical obstructive kidney injury after modeling. After USC-Exo treatment, the shape of the renal pelvis shown a remarkable improvement, and inflammation and fibrosis decreased. Conclusions: We confirmed that miR-122-5p from USC-Exos targeting SOX2 is a new molecular target for postoperative recovery treatment of obstructive kidney injury.

Molecular mechanism of Gan-song Yin inhibiting the proliferation of renal tubular epithelial cells by regulating miR-21-5p in adipocyte exosomes

ETHNOPHARMACOLOGICAL RELEVANCE

Gan-song Yin is derived from the classic ancient prescription " Gan-song pill " for the treatment of wasting-thirst in Ningxia combined with the characteristic "fragrant medicine". It is clinically used for the treatment of early renal fibrosis caused by diabetic nephropathy. Previous studies have shown that it has a good effect and great potential in the prevention and treatment of diabetic nephropathy, but its mechanism research is still limited.

AIM OF THE STUDY

To investigate the mechanism of GSY to improve DN by interfering with miR-21-5p and glycolipid metabolism in adipocyte exosomes using 3T3-L1 and TCMK-1 co-culture system.

MATERIALS AND METHODS

The co-culture system of 3T3-L3 and TCMK-1 was established, the IR model was established, and the stability, lipid drop change, glucose consumption, triglyceride content, cell viability, cell cycle and apoptosis level, protein content and mRNA expression of the IR model were detected.

RESULTS

GSY inhibited 3T3-L1 activity, increased glucose consumption and decreased TG content. Decreased TCMK-1 cell viability, inhibited apoptosis, cell cycle arrest occurred in G0/G1 phase and S phase. Adipocyte IR model and co-culture system were stable within 48 h. After GSY intervention, lipid droplet decomposition and glucose consumption increased. The TG content of adipocytes increased, while the TG content of co-culture system decreased. GSY can regulate the expression of TGF-β1/SMAD signaling pathway protein in IR state. After GSY intervention, the expression of miR-21-5p was increased in 3T3-L1 and Exo cells, and decreased in TCMK-1 cells.

CONCLUSIONS

GSY can regulate TGF-β1/SMAD signaling pathway through the secretion of miR-21-5p from adipocytes, protect IR TCMK-1, regulate the protein and mRNA expression levels of PPARγ, GLUT4, FABP4, and improve glucose and lipid metabolism.

Efficacy of adipose-derived mesenchymal stem cell therapy in the treatment of chronic micro- and macrovascular complications of diabetes

Diabetes mellitus is a highly prevalent disease characterized by hyperglycaemia that damages the vascular system, leading to micro- (retinopathy, neuropathy, nephropathy) and macrovascular diseases (cardiovascular disease). There are also secondary complications of diabetes (cardiomyopathy, erectile dysfunction or diabetic foot ulcers). Stem cell-based therapies have become a promising tool targeting diabetes symptoms and its chronic complications. Among all stem cells, adipose-derived mesenchymal stem cells (ADMSCs) are of great importance because of their abundance, non-invasive isolation and no ethical limitations. Characteristics that make ADMSCs good candidates for cell-based therapy are their wide immunomodulatory properties and paracrine activities through the secretion of an array of growth factors, chemokines, cytokines, angiogenic factors and anti-apoptotic molecules. Besides, after transplantation, ADMSCs show great ex vivo expansion capacity and differentiation to other cell types, including insulin-producing cells, cardiomyocytes, chondrocytes, hepatocyte-like cells, neurons, endothelial cells, photoreceptor-like cells, or astrocytes. Preclinical studies have shown that ADMSC-based therapy effectively improved visual acuity, ameliorated polyneuropathy and foot ulceration, arrested the development and progression of diabetic kidney disease, or alleviated the diabetes-induced cardiomyocyte hypertrophy. However, despite the positive results obtained in animal models, there are still several challenges that need to be overcome before the results of preclinical studies can be translated into clinical applications. To date, there are several clinical trials or ongoing trials using ADMSCs in the treatment of diabetic complications, most of them in the treatment of diabetic foot ulcers. This narrative review summarizes the most recent outcomes on the usage of ADMSCs in the treatment of long-term complications of diabetes in both animal models and clinical trials.

Urine-derived podocytes from steroid resistant nephrotic syndrome patients as a model for renal-progenitor derived extracellular vesicles effect and drug screening

Background

Personalized disease models are crucial for assessing the specific response of diseased cells to drugs, particularly novel biological therapeutics. Extracellular vesicles (EVs), nanosized vesicles released by cells for intercellular communication, have gained therapeutic interest due to their ability to reprogram target cells. We here utilized urinary podocytes obtained from children affected by steroid-resistant nephrotic syndrome with characterized genetic mutations as a model to test the therapeutic potential of EVs derived from kidney progenitor cells.

Methods

EVs were isolated from kidney progenitor cells (nKPCs) derived from the urine of a preterm neonate. Three lines of urinary podocytes obtained from nephrotic patients' urine and a line of Alport patient podocytes were characterized and used to assess albumin permeability in response to various drugs or to nKPC-EVs. RNA sequencing was conducted to identify commonly modulated pathways.

Results

Podocytes appeared unresponsive to pharmacological treatments, except for a podocyte line demonstrating responsiveness, in alignment with the patient's clinical response at 48 months. At variance, treatment with the nKPC-EVs was able to significantly reduce permeability in all the steroid-resistant patients-derived podocytes as well as in the line of Alport-derived podocytes. RNA sequencing of nKPC-EV-treated podocytes revealed the common upregulation of two genes (small ubiquitin-related modifier 1 (SUMO1) and Sentrin-specific protease 2 (SENP2)) involved in the SUMOylation pathway, a process recently demonstrated to play a role in slit diaphragm stabilization. Gene ontology analysis on podocyte expression profile highlighted cell-to-cell adhesion as the primary upregulated biological activity in treated podocytes.

Conclusions

nKPCs emerge as a promising non-invasive source of EVs with potential therapeutic effects on podocyte dysfunction. Furthermore, our findings suggest the possibility of establishing a non-invasive in vitro model for screening regenerative compounds on patient-derived podocytes.

Extracellular vesicles as tools and targets in therapy for diseases

Extracellular vesicles (EVs) are nano-sized, membranous structures secreted into the extracellular space. They exhibit diverse sizes, contents, and surface markers and are ubiquitously released from cells under normal and pathological conditions. Human serum is a rich source of these EVs, though their isolation from serum proteins and non-EV lipid particles poses challenges. These vesicles transport various cellular components such as proteins, mRNAs, miRNAs, DNA, and lipids across distances, influencing numerous physiological and pathological events, including those within the tumor microenvironment (TME). Their pivotal roles in cellular communication make EVs promising candidates for therapeutic agents, drug delivery systems, and disease biomarkers. Especially in cancer diagnostics, EV detection can pave the way for early identification and offers potential as diagnostic biomarkers. Moreover, various EV subtypes are emerging as targeted drug delivery tools, highlighting their potential clinical significance. The need for non-invasive biomarkers to monitor biological processes for diagnostic and therapeutic purposes remains unfulfilled. Tapping into the unique composition of EVs could unlock advanced diagnostic and therapeutic avenues in the future. In this review, we discuss in detail the roles of EVs across various conditions, including cancers (encompassing head and neck, lung, gastric, breast, and hepatocellular carcinoma), neurodegenerative disorders, diabetes, viral infections, autoimmune and renal diseases, emphasizing the potential advancements in molecular diagnostics and drug delivery.

Understanding exosomes: Part 2-Emerging leaders in regenerative medicine

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.

miR-26a-5p Attenuates Oxidative Stress and Inflammation in Diabetic Retinopathy through the USP14/NF-κB Signaling Pathway

Purpose

Diabetic retinopathy (DR) is an ocular disease caused by diabetes and may lead to vision impairment and even blindness. Oxidative stress and inflammation are two key pathogenic factors of DR. Recently, regulatory roles of different microRNAs (miRNAs) in DR have been widely verified. miR-26a-5p has been confirmed to be a potential biomarker of DR. Nevertheless, the specific functions of miR-26a-5p in DR are still unclear.

Methods

Primary cultured mouse retinal Müller cells in exposure to high glucose (HG) were used to establish an in vitro DR model. Müller cells were identified via morphology observation under phase contrast microscope and fluorescence staining for glutamine synthetase. The in vivo animal models for DR were constructed using streptozotocin-induced diabetic C57BL/6 mice. Western blotting was performed to quantify cytochrome c protein level in the cytoplasm and mitochondria of Müller cells and to measure protein levels of glial fibrillary acidic protein (GFAP), ubiquitin-specific peptidase 14 (USP14), as well as factors associated with NF-κB signaling (p-IκBα, IκBα, p-p65, and p65) in Müller cells or murine retinal tissues. ROS production was detected by CM-H2DCFDA staining, and the concentration of oxidative stress markers (MDA, SOD, and CAT) was estimated by using corresponding commercial kits. Quantification of mRNA expression was conducted by RT-qPCR analysis. The concentration of proinflammatory factors (TNF-α, IL-1β, and IL-6) was evaluated by ELISA. Hematoxylin-eosin staining for murine retinal tissues was performed for histopathological analysis. Immunofluorescence staining was conducted to determine NF-κB p65 nuclear translocation in Müller cells. Furthermore, the interaction between miR-26a-5p and USP14 was verified via the luciferase reporter assays.

Results

HG stimulation contributed to Müller cell dysfunction by inducing inflammation, oxidative injury, and mitochondrial damage to Müller cells. miR-26a-5p was downregulated in Müller cells under HG condition, and overexpression of miR-26a-5p relieved HG-induced Müller cell dysfunction. Moreover, miR-26a-5p targeted USP14 and inversely regulated USP14 expression. Additionally, HG-evoked activation of NF-κB signaling was suppressed by USP14 knockdown or miR-26a-5p upregulation. Rescue assays showed that the protective impact of miR-26a-5p upregulation against HG-induced Müller cell dysfunction was reversed by USP14 overexpression. Furthermore, USP14 upregulation and activation of NF-κB signaling in the retinas of DR mice were detected in animal experiments. Injection with miR-26a-5p agomir improved retinal histopathological injury and weakened the concentration of proinflammatory cytokines and oxidative stress markers in the retinas of DR mice.

Conclusion

miR-26a-5p inhibits oxidative stress and inflammation in DR progression by targeting USP14 and inactivating the NF-κB signaling pathway.

Progress and application of adipose-derived stem cells in the treatment of diabetes and its complications

Diabetes mellitus (DM) is a serious chronic metabolic disease that can lead to many serious complications, such as cardiovascular disease, retinopathy, neuropathy, and kidney disease. Once diagnosed with diabetes, patients need to take oral hypoglycemic drugs or use insulin to control blood sugar and slow down the progression of the disease. This has a significant impact on the daily life of patients, requiring constant monitoring of the side effects of medication. It also imposes a heavy financial burden on individuals, their families, and even society as a whole. Adipose-derived stem cells (ADSCs) have recently become an emerging therapeutic modality for DM and its complications. ADSCs can improve insulin sensitivity and enhance insulin secretion through various pathways, thereby alleviating diabetes and its complications. Additionally, ADSCs can promote tissue regeneration, inhibit inflammatory reactions, and reduce tissue damage and cell apoptosis. The potential mechanisms of ADSC therapy for DM and its complications are numerous, and its extensive regenerative and differentiation ability, as well as its role in regulating the immune system and metabolic function, make it a powerful tool in the treatment of DM. Although this technology is still in the early stages, many studies have already proven its safety and effectiveness, providing new treatment options for patients with DM or its complications. Although based on current research, ADSCs have achieved some results in animal experiments and clinical trials for the treatment of DM, further clinical trials are still needed before they can be applied in a clinical setting.

Mesenchymal Stromal Cells Nanovesicles Carry microRNA with Nephroprotective Proprieties Regardless of Aging

Containing information molecules from their parent cells and inclining to fuse with targeted cells, bone marrow mesenchymal stromal cells-derived extracellular vesicles (MSCs- EV) are valuable in nanomedicine.

BACKGROUND

The effects of aging on the paracrine mechanism and in the production and action of MSCs-EV and their cargos of miR-26a and siRNA-26a for the treatment of tubular renal cells under nephrotoxicity injury remain unelucidated.

OBJECTIVE

The purpose of this study was to evaluate MSCs-EV of different ages and their ability to deliver the cargos of miR-26a and siRNA-26a to target renal tubular cells affected by nephrotoxicity injury.

METHODS

In a model of gentamicin-induced nephrotoxicity, renal tubular cells treated with MSCs-EV expressing or not expressing microRNA-26a were analyzed. Western blotting was utilized to evaluate cell cycle markers, and MTT assay was utilized to evaluate auto-renovation capacity.

RESULTS

Tubular cells under nephrotoxicity injury showed decreased proliferative capacity, but the treatment in the tubular renal cells under nephrotoxicity injury with MSCs-EV expressing microRNA-26a showed nephroprotective effects, regardless of EV age. While the treatment with EV-mediated siRNA-26a failed to preserve the nephroprotective effects equally, regardless of age.

CONCLUSION

Mesenchymal stromal cell nanovesicles carry microRNA with nephroprotective proprieties regardless of aging.

Aging and Metabolic Reprogramming of Adipose-Derived Stem Cells Affect Molecular Mechanisms Related to Cardiovascular Diseases

We performed a systematic search of the PubMed database for English-language articles related to the function of adipose-derived stem cells in the pathogenesis of cardiovascular diseases. In preclinical models, adipose-derived stem cells protected arteries and the heart from oxidative stress and inflammation and preserved angiogenesis. However, clinical trials did not reiterate successful treatments with these cells in preclinical models. The low success in patients may be due to aging and metabolic reprogramming associated with the loss of proliferation capacity and increased senescence of stem cells, loss of mitochondrial function, increased oxidative stress and inflammation, and adipogenesis with increased lipid deposition associated with the low potential to induce endothelial cell function and angiogenesis, cardiomyocyte survival, and restore heart function. Then, we identify noncoding RNAs that may be mechanistically related to these dysfunctions of human adipose-derived stem cells. In particular, a decrease in let-7, miR-17-92, miR-21, miR-145, and miR-221 led to the loss of their function with obesity, type 2 diabetes, oxidative stress, and inflammation. An increase in miR-34a, miR-486-5p, and mir-24-3p contributed to the loss of function, with a noteworthy increase in miR-34a with age. In contrast, miR-146a and miR-210 may protect stem cells. However, a systematic analysis of other noncoding RNAs in human adipose-derived stem cells is warranted. Overall, this review gives insight into modes to improve the functionality of human adipose-derived stem cells.

Exosomal microRNAs: potential nanotherapeutic targets for diabetic kidney disease

Diabetic kidney disease (DKD) is a primary cause for end-stage renal disease, but no specific therapeutic approaches exist. Exosomal miRNAs, a key functional cargo of nanovesicles, play crucial roles in the pathophysiological processes of DKD. Exosomal miRNAs are involved in cell-to-cell transfer of biological information, mediating nephritic inflammation, oxidative stress, apoptosis, autophagy, epithelial-mesenchymal transition and fibrosis. Circulating exosomal miRNAs derived from urine or serum might function as noninvasive prognostic biomarkers for DKD. Exosomal miRNAs from stem cells have been reported to exert beneficial effects on diabetic kidneys, which suggests that these exosomes might function as potential nanotherapy tools for treating DKD. In this review, we have summarized recent studies based on the association between exosomal miRNAs and DKD.

The role of miRNAs carried by extracellular vesicles in type 2 diabetes and its complications

Diabetes poses severe global public health problems and places heavy burdens on the medical and economic systems of society. Type 2 diabetes (T2D) accounts for 90% of these cases. Diabetes also often accompanies serious complications that threaten multiple organs such as the brain, eyes, kidneys, and the cardiovascular system. MicroRNAs (miRNAs) carried by extracellular vesicles (EV-miRNAs) are considered to mediate cross-organ and cross-cellular communication and have a vital role in the pathophysiology of T2D. They also offer promising sources of diabetes-related biomarkers and serve as effective therapeutic targets. Here, we briefly reviewed studies of EV-miRNAs in T2D and related complications. Specially, we innovatively explore the targeting nature of miRNA action due to the target specificity of vesicle binding, aiding mechanism understanding as well as the detection and treatment of diseases.

Synergism of calycosin and bone marrow-derived mesenchymal stem cells to combat podocyte apoptosis to alleviate adriamycin-induced focal segmental glomerulosclerosis

BACKGROUND

Bone marrow-derived mesenchymal stem cells (MSCs) show podocyte-protective effects in chronic kidney disease. Calycosin (CA), a phytoestrogen, is isolated from Astragalus membranaceus with a kidney-tonifying effect. CA preconditioning enhances the protective effect of MSCs against renal fibrosis in mice with unilateral ureteral occlusion. However, the protective effect and underlying mechanism of CA-pretreated MSCs (MSCsCA) on podocytes in adriamycin (ADR)-induced focal segmental glomerulosclerosis (FSGS) mice remain unclear.

AIM

To investigate whether CA enhances the role of MSCs in protecting against podocyte injury induced by ADR and the possible mechanism involved.

METHODS

ADR was used to induce FSGS in mice, and MSCs, CA, or MSCsCA were administered to mice. Their protective effect and possible mechanism of action on podocytes were observed by Western blot, immunohistochemistry, immunofluorescence, and real-time polymerase chain reaction. In vitro, ADR was used to stimulate mouse podocytes (MPC5) to induce injury, and the supernatants from MSC-, CA-, or MSCsCA-treated cells were collected to observe their protective effects on podocytes. Subsequently, the apoptosis of podocytes was detected in vivo and in vitro by Western blot, TUNEL assay, and immunofluorescence. Overexpression of Smad3, which is involved in apoptosis, was then induced to evaluate whether the MSCsCA-mediated podocyte protective effect is associated with Smad3 inhibition in MPC5 cells.

RESULTS

CA-pretreated MSCs enhanced the protective effect of MSCs against podocyte injury and the ability to inhibit podocyte apoptosis in ADR-induced FSGS mice and MPC5 cells. Expression of p-Smad3 was upregulated in mice with ADR-induced FSGS and MPC5 cells, which was reversed by MSCCA treatment more significantly than by MSCs or CA alone. When Smad3 was overexpressed in MPC5 cells, MSCsCA could not fulfill their potential to inhibit podocyte apoptosis.

CONCLUSION

MSCsCA enhance the protection of MSCs against ADR-induced podocyte apoptosis. The underlying mechanism may be related to MSCsCA-targeted inhibition of p-Smad3 in podocytes.

Understanding the lncRNA/miRNA-NFκB regulatory network in Diabetes Mellitus: From function to clinical translation

Diabetes mellitus (DM) and its significant ramifications make out one of the primary reasons behind morbidity worldwide. Noncoding RNAs (ncRNAs), such as microRNAs and long noncoding RNAs, are involved in regulating manifold biological processes, including diabetes initiation and progression. One of the established pathways attributed to DM development is NF-κB signaling. Neurons, β cells, adipocytes, and hepatocytes are among the metabolic tissues where NF-κB is known to produce a range of inflammatory chemokines and cytokines. The direct or indirect role of ncRNAs such as lncRNAs and miRNAs on the NF-κB signaling pathway and DM development has been supported by many studies. As a result, effective diabetes treatment and preventive methods will benefit from a comprehensive examination of the interplay between NF-κB and ncRNAs. Herein, we provide a concise overview of the role of NF-κB-mediated signaling pathways in diabetes mellitus and its consequences. The reciprocal regulation of ncRNAs and the NF-κB signaling pathway in diabetes is then discussed, shedding light on the pathogenesis of the illness and its possible therapeutic interventions.

Stem cell-derived exosomal MicroRNAs: Potential therapies in diabetic kidney disease

The diabetic kidney disease (DKD) is chronic kidney disease caused by diabetes and one of the most common comorbidities. It is often more difficult to treat end-stage renal disease once it develops because of its complex metabolic disorders, so early prevention and treatment are important. However, currently available DKD therapies are not ideal, and novel therapeutic strategies are urgently needed. The potential of stem cell therapies partly depends on their ability to secrete exosomes. More and more studies have shown that stem cell-derived exosomes take part in the DKD pathophysiological process, which may offer an effective therapy for DKD treatment. Herein, we mainly review potential therapies of stem cell-derived exosomes mainly stem cell-derived exosomal microRNAs in DKD, including their protective effects on mesangial cells, podocytes and renal tubular epithelial cells. Using this secretome as possible therapeutic drugs without potential carcinogenicity should be the focus of further research.

An update on renal fibrosis: from mechanisms to therapeutic strategies with a focus on extracellular vesicles

The increasing prevalence of chronic kidney disease (CKD) is a major global public health concern. Despite the complicated pathogenesis of CKD, renal fibrosis represents the most common pathological condition, comprised of progressive accumulation of extracellular matrix in the diseased kidney. Over the last several decades, tremendous progress in understanding the mechanism of renal fibrosis has been achieved, and corresponding potential therapeutic strategies targeting fibrosis-related signaling pathways are emerging. Importantly, extracellular vesicles (EVs) contribute significantly to renal inflammation and fibrosis by mediating cellular communication. Increasing evidence suggests the potential of EV-based therapy in renal inflammation and fibrosis, which may represent a future direction for CKD therapy.

CRISPR-Cas9 editing of TLR4 to improve the outcome of cardiac cell therapy

Inflammation and fibrosis limit the reparative properties of human mesenchymal stromal cells (hMSCs). We hypothesized that disrupting the toll-like receptor 4 (TLR4) gene would switch hMSCs toward a reparative phenotype and improve the outcome of cell therapy for infarct repair. We developed and optimized an improved electroporation protocol for CRISPR-Cas9 gene editing. This protocol achieved a 68% success rate when applied to isolated hMSCs from the heart and epicardial fat of patients with ischemic heart disease. While cell editing lowered TLR4 expression in hMSCs, it did not affect classical markers of hMSCs, proliferation, and migration rate. Protein mass spectrometry analysis revealed that edited cells secreted fewer proteins involved in inflammation. Analysis of biological processes revealed that TLR4 editing reduced processes linked to inflammation and extracellular organization. Furthermore, edited cells expressed less NF-ƙB and secreted lower amounts of extracellular vesicles and pro-inflammatory and pro-fibrotic cytokines than unedited hMSCs. Cell therapy with both edited and unedited hMSCs improved survival, left ventricular remodeling, and cardiac function after myocardial infarction (MI) in mice. Postmortem histologic analysis revealed clusters of edited cells that survived in the scar tissue 28 days after MI. Morphometric analysis showed that implantation of edited cells increased the area of myocardial islands in the scar tissue, reduced the occurrence of transmural scar, increased scar thickness, and decreased expansion index. We show, for the first time, that CRISPR-Cas9-based disruption of the TLR4-gene reduces pro-inflammatory polarization of hMSCs and improves infarct healing and remodeling in mice. Our results provide a new approach to improving the outcomes of cell therapy for cardiovascular diseases.

Stem Cells in Kidney Ischemia: From Inflammation and Fibrosis to Renal Tissue Regeneration

Ischemic nephropathy consists of progressive renal function loss due to renal hypoxia, inflammation, microvascular rarefaction, and fibrosis. We provide a literature review focused on kidney hypoperfusion-dependent inflammation and its influence on renal tissue's ability to self-regenerate. Moreover, an overview of the advances in regenerative therapy with mesenchymal stem cell (MSC) infusion is provided. Based on our search, we can point out the following conclusions: 1. endovascular reperfusion is the gold-standard therapy for RAS, but its success mostly depends on treatment timeliness and a preserved downstream vascular bed; 2. anti-RAAS drugs, SGLT2 inhibitors, and/or anti-endothelin agents are especially recommended for patients with renal ischemia who are not eligible for endovascular reperfusion for slowing renal damage progression; 3. TGF-β, MCP-1, VEGF, and NGAL assays, along with BOLD MRI, should be extended in clinical practice and applied to a pre- and post-revascularization protocols; 4. MSC infusion appears effective in renal regeneration and could represent a revolutionary treatment for patients with fibrotic evolution of renal ischemia.

Peroxiredoxin 6 alleviates high glucose-induced inflammation and apoptosis in HK-2 cells by inhibiting TLR4/NF-κB signaling

Background

This research sought to elucidate the effects of peroxiredoxin 6 (PRDX6) on the biological processes in diabetic nephropathy (DN) and to identify the underlying regulatory mechanism related to toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling.

Methods

To induce an in vitro DN cellular model, human kidney 2 (HK-2) cells were treated with high glucose (HG). The mitochondrial membrane potential, adenosine triphosphate level, reactive oxygen species generation, and oxidative stress of the cells were then evaluated. After the PRDX6 level had been determined, the effects of its overexpression on the mitochondrial membrane potential, adenosine triphosphate level, reactive oxygen species generation, and oxidative stress of the cells were assessed. Next, cytochrome c expression, cell viability, cell apoptosis, the inflammatory level, and the TLR4/NF-κB signaling-related factors were assessed. After the addition of the TLR4 activator CRX-527 or the NF-κB activator phorbol 12-myristate 13-acetate (PMA), cell viability, cell apoptosis and the inflammatory level were evaluated again.

Results

The results revealed that HG exposure triggered mitochondrial dysfunction and oxidative stress and decreased PRDX6 expression in the HK-2 cells. PRDX6 elevation exacerbated cell viability while alleviating mitochondrial membrane potential loss, oxidative stress, apoptosis, and inflammation in the HG-treated HK-2 cells. Further, PRDX6 inhibited HG-induced TLR4/NF-κB activation. The administration of CRX-527 or PMA reversed the effects of PRDX6 on the cell viability, apoptosis, and inflammation of the HG-exposed HK-2 cells.

Conclusions

To conclude, PRDX6 appears to protect HG-exposed HK-2 cells against inflammation and apoptosis by inhibiting TLR4/NF-κB signaling.

An Overview of Inter-Tissue and Inter-Kingdom Communication Mediated by Extracellular Vesicles in the Regulation of Mammalian Metabolism

Obesity and type 2 diabetes are associated with defects of insulin action in different tissues or alterations in β-cell secretory capacity that may be triggered by environmental challenges, inadequate lifestyle choices, or an underlying genetic predisposition. In addition, recent data shows that obesity may also be caused by perturbations of the gut microbiota, which then affect metabolic function and energy homeostasis in the host. Maintenance of metabolic homeostasis in complex organisms such as mammals requires organismal-level communication, including between the different organs and the gut microbiota. Extracellular vesicles (EVs) have been identified in all domains of life and have emerged as crucial players in inter-organ and inter-kingdom crosstalk. Interestingly, EVs found in edible vegetables or in milk have been shown to influence gut microbiota or tissue function in mammals. Moreover, there is a multidirectional crosstalk mediated by EVs derived from gut microbiota and body organs that has implications for host health. Untangling this complex signaling network may help implement novel therapies for the treatment of metabolic disease.

Small extracellular vesicle-loaded bevacizumab reduces the frequency of intravitreal injection required for diabetic retinopathy

Diabetic retinopathy (DR) is associated with retinal neovascularization, hard exudates, inflammation, oxidative stress and cell death, leading to vision loss. Anti-vascular endothelial growth factor (Anti-VEGF) therapy through repeated intravitreal injections is an established treatment for reducing VEGF levels in the retina for inhibiting neovascularization and leakage of hard exudates to prevent vision loss. Although anti-VEGF therapy has several clinical benefits, its monthly injection potentially causes devastating ocular complications, including trauma, intraocular hemorrhage, retinal detachment, endophthalmitis, etc. Methods: As mesenchymal stem cells (MSCs) and MSC-derived extracellular vesicles (MSC-EVs) demonstrated safety in clinical studies, we have tested the efficacy of MSC-derived small EVs (MSC-sEVs) loaded anti-VEGF drug bevacizumab in a rat model of DR. Results: The study identified a clinically significant finding that sEV loaded with bevacizumab reduces the frequency of intravitreal injection required for treating diabetic retinopathy. The sustained effect is observed from the reduced levels of VEGF, exudates and leukostasis for more than two months following intravitreal injection of sEV loaded with bevacizumab, while bevacizumab alone could maintain reduced levels for about one month. Furthermore, retinal cell death was consistently lower in this period than only bevacizumab. Conclusion: This study provided significant evidence for the prolonged benefits of sEVs as a drug delivery system. Also, EV-mediated drug delivery systems could be considered for clinical application of retinal diseases as they maintain vitreous clarity in the light path due to their composition being similar to cells.

Research progress on exosomes in podocyte injury associated with diabetic kidney disease

Diabetic kidney disease (DKD), a common cause of end-stage renal disease, is a serious complication that develops with the progression of chronic diabetes. Its main clinical manifestations are persistent proteinuria and/or a progressive decline in the estimated glomerular filtration rate. Podocytes, terminally differentiated glomerular visceral epithelial cells, constitute the glomerular filtration barrier together with the basement membrane and endothelial cells, and the structural and functional barrier integrity is closely related to proteinuria. In recent years, an increasing number of studies have confirmed that podocyte injury is the central target of the occurrence and development of DKD, and research on exosomes in podocyte injury associated with DKD has also made great progress. The aim of this review is to comprehensively describe the potential diagnostic value of exosomes in podocyte injury associated with DKD, analyze the mechanism by which exosomes realize the communication between podocytes and other types of cells and discuss the possibility of exosomes as targeted therapy drug carriers to provide new targets for and insights into delaying the progression of and treating DKD.

Treatment with EV-miRNAs Alleviates Obesity-Associated Metabolic Dysfunction in Mice

Most cells release extracellular vesicles (EVs) that can be detected circulating in blood. We and others have shown that the microRNA contents of these vesicles induce transcriptomic changes in acceptor cells, contributing to the adjustment of metabolic homeostasis in response to environmental demands. Here, we explore the potential for modulating obesity- and exercise-derived EV-microRNAs to treat the metabolic dysfunction associated with obesity in mice. Treatment with EV-miRNAs alleviated glucose intolerance and insulin resistance in obese mice to an extent similar to that of high-intensity interval training, although only exercise improved cardiorespiratory fitness and decreased body weight. Mechanistically, EV-miRNAs decreased fatty acid and cholesterol biosynthesis pathways in the liver, reducing hepatic steatosis and increasing insulin sensitivity, resulting in decreased glycemia and triglyceridemia. Our data suggest that manipulation of EV-miRNAs may be a viable strategy to alleviate metabolic dysfunction in obese and diabetic patients who are unable to exercise, although actual physical activity is needed to improve cardiorespiratory fitness.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: A Potential Therapy for Diabetes Mellitus and Diabetic Complications

As a novel cell-free strategy, mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) inherit the therapeutic potential of donor cells, and are widely used for the treatment of many diseases. Increasing studies have shown that MSC-EVs transfer various bioactive molecules to create a beneficial microenvironment, thus exerting protective roles in diabetic mellitus (DM) and diabetic complications. To overcome the limitations of natural MSC-EVs such as heterogeneity and insufficient function, several modification methods have been established for constructing engineered MSC-EVs with elevated repairing efficiency. In this review, the PubMed library was searched from inception to August 2022, using a combination of Medical Subject Headings (MeSH) and keywords related to MSC-EVs, DM, and diabetic complications. We provide an overview of the major characteristics of MSC-EVs and summarize the recent advances of MSC-EV-based therapy for hyperglycemia-induced tissue damage with an emphasis on MSC-EV-mediated delivery of functional components. Moreover, the potential applications of engineered MSC-EVs in DM-related diseases therapy are discussed by presenting examples, and the opportunities and challenges for the clinical translation of MSC-EVs, especially engineered MSC-EVs, are evaluated.

Long noncoding RNA SNHG5 promotes podocyte injury via the microRNA-26a-5p/TRPC6 pathway in diabetic nephropathy

Podocyte injury is a characteristic pathological hallmark of diabetic nephropathy (DN). However, the exact mechanism of podocyte injury in DN is incompletely understood. This study was conducted using db/db mice and immortalized mouse podocytes. High-throughput sequencing was used to identify the differentially expressed long noncoding RNAs in kidney of db/db mice. The lentiviral shRNA directed against long noncoding RNA small nucleolar RNA host gene 5 (SNHG5) or microRNA-26a-5p (miR-26a-5p) agomir was used to treat db/db mice to regulate the SNHG5/miR-26a-5p pathway. Here, we found that the expression of transient receptor potential canonical type 6 (TRPC6) was significantly increased in injured podocytes under the condition of DN, which was associated with markedly decreased miR-26a-5p. We determined that miR-26a-5p overexpression ameliorated podocyte injury in DN via binding to 3'-UTR of Trpc6, as evidenced by the markedly reduced activity of luciferase reporters by miR-26a-5p mimic. Then, the upregulated SNHG5 in podocytes and kidney in DN was identified, and it was proved to sponge to miR-26a-5p directly using luciferase activity, RNA immunoprecipitation, and RNA pull-down assay. Knockdown of SNHG5 attenuated podocyte injury in vitro, accompanied by an increased expression of miR-26a-5p and decreased expression of TRPC6, demonstrating that SNHG5 promoted podocyte injury by controlling the miR-26a-5p/TRPC6 pathway. Moreover, knockdown of SNHG5 protects against podocyte injury and progression of DN in vivo. In conclusion, SNHG5 promotes podocyte injury via the miR-26a-5p/TRPC6 pathway in DN. Our findings provide novel insights into the pathophysiology of podocyte injury and a potential new therapeutic strategy for DN.

Exosomes derived from mesenchymal stem cells attenuate diabetic kidney disease by inhibiting cell apoptosis and epithelial-to-mesenchymal transition via miR-424-5p

Diabetic kidney disease (DKD) is well-acknowledged as one of the most common complications in diabetes mellitus. Recent studies have demonstrated the promising role of mesenchymal stem cell-derived exosomes (MSC-exos) as a cell-free treatment strategy for DKD. The present study sought to investigate the therapeutic potential and the underlying mechanisms of MSC-exos in DKD. The authentication of MSC-exos was validated by western blot, transmission electron microscope (TEM), and nanosight tracking analysis (NTA). Apoptosis was detected by western blot, TUNEL staining, and flow cytometry. Epithelial-to-mesenchymal transition (EMT) was evaluated by western blot and immunofluorescence. The relationship between miR-424-5p and Yes-associated protein 1 (YAP1) was revealed by dual luciferase reporter assay. We observed that MSC-exos could attenuate DKD by decreasing cell apoptosis and inhibiting epithelial-to-mesenchymal transition (EMT) in diabetic kidneys in db/db mice. Besides, we documented that MSC-exos could reverse high glucose-induced apoptosis and EMT in HK2 cells. Interestingly, miR-424-5p derived from MSC-exos could inhibit YAP1 activation in HK2 cells, resulting in alleviation of high glucose-induced cell apoptosis and EMT. Our study provides novel insights into MSC-exos-mediated protective effect in DKD. MSC-exos could inhibit high glucose-induced apoptosis and EMT through miR-424-5p targeting of YAP1.

linc00174 deteriorates the pathogenesis of diabetic retinopathy via miR-26a-5p/PTEN/Akt signalling cascade-mediated pyroptosis

PURPOSE

We aim to investigate the potential role and underlying mechanisms of linc00174 on pyroptosis in the pathogenesis of DR.

METHODS

Expression patterns of linc00174, miR-26a-5p and PTEN in human retinal microvascular endothelial cells (hRMECs) were detected by quantitative real-time PCR (qRT-PCR) and Western blot, respectively. Biological functions of linc00174 on cell proliferation and pyroptosis were evaluated by CCK-8, flow cytometry, caspase-1 activity assays, respectively. Luciferase reporter assay was employed to verify the interaction between miR-26a-5p and linc00174/PTEN. Streptozotocin (STZ)-induced DR in mice was further constructed to verify the potential role of linc00174 in vivo. Hematoxylin and eosin (H&E) and immunohistochemical staining were performed to assess the pathological changes and caspase-1 expression in retinal tissues.

RESULTS

Up-regulated linc00174 and PTEN and down-regulated miR-26a-5p were uncovered in hRMECs treated with high glucose (HG). Mechanistically, linc00174 served as a sponge of miR-26a-5p to facilitate PTEN expression. Functionally, knockdown of linc00174 inhibited HG-induced pyroptosis of hRMECs via targeting miR-26a-5p. Moreover, linc00174/miR-26a-5p axis participated in HG-induced pyroptosis via PTEN/Akt signaling cascade. Further, silencing of linc00174 attenuated pyroptosis via regulating miR-26a-5p/PETN axis in DR mice.

CONCLUSIONS

Collectively, our study reveals that linc10074 deteriorates the pathogenesis of DR via miR-26a-5p/PTEN/Akt signalling cascade, which may shed light on the discovery of potential therapeutic agents for DR treatment.

Adipose mesenchymal stem cell-derived exosomal microRNAs ameliorate polycystic ovary syndrome by protecting against metabolic disturbances

Polycystic ovary syndrome (PCOS) is the most common endocrine and metabolic disorder in women of childbearing age. Adipose mesenchymal stem cells (AMSCs) secrete cytokines involved in the regulation of metabolism and immunity. However, it remains unclear whether exosomes secreted by AMSCs (AMSC-EXOs) can rescue the polycystic phenotype and metabolic dysfunction in PCOS ovaries. Here, we show that AMSC-EXOs can protect against metabolic disturbances, ameliorate ovarian polycystic, and improve fertility in a rat model of PCOS. AMSC-EXOs inhibited the expression of B-cell translocation gene 2 by transferring miR-21-5p to the livers of rats with PCOS, thus activating the IRS1/AKT pathway and increasing hepatic metabolism. The role of AMSC-EXOs in transferring miRNAs to the liver to improve metabolic dysfunction in PCOS and reproduction by rescuing a non-coding RNA pathway was also discovered. This study provides a theoretical basis for the use of rat adipose stem cells and their secreted exosomes to treat PCOS.

An overview of the efficacy and signaling pathways activated by stem cell-derived extracellular vesicles in diabetic kidney disease

Diabetic kidney disease (DKD) is one of complications of diabetes mellitus with severe microvascular lesion and the most common cause of end-stage chronic kidney disease (ESRD). Controlling serum glucose remains the primary approach to preventing and slowing the progression of DKD. Despite considerable efforts to control diabetes, people with diabetes develop not only DKD but also ESRD. The pathogenesis of DKD is very complex, and current studies indicate that mesenchymal stromal cells (MSCs) regulate complex disease processes by promoting pro-regenerative mechanisms and inhibiting multiple pathogenic pathways. Extracellular vesicles (EVs) are products of MSCs. Current data indicate that MSC-EVs-based interventions not only protect renal cells, including renal tubular epithelial cells, podocytes and mesangial cells, but also improve renal function and reduce damage in diabetic animals. As an increasing number of clinical studies have confirmed, MSC-EVs may be an effective way to treat DKD. This review explores the potential efficacy and signaling pathways of MSC-EVs in the treatment of DKD.

The Role of Mesenchymal Stem Cells in the Treatment of Type 1 Diabetes

Type 1 diabetes (T1D) is a chronic disease characterized by inadequate or absent insulin production due to the autoimmune destruction of beta (β) cells in the pancreas. It was once called "juvenile diabetes" since the disease frequently occurs in children, but it can also develop in adults. According to the International Diabetes Federation, an estimated 700 million adults will suffer from diabetes by 2045. Although the exact cause of diabetes remains unknown, it is hypothesized that genetic factors, environmental factors, and exposure to certain viruses play a role in the development of T1D. To date, exogenous insulin is the most common treatment for T1D. However, it is not a cure for the disease. Islet cell transplantation and pancreatic transplantation are two additional treatments that have gained popularity in recent years, but their clinical application may be limited by the need for high doses of immunosuppressants, the rarity of human cadaveric islets, and the need for extensive surgery in pancreatic transplantation. Mesenchymal stem cells (MSCs) are a highly promising novel treatment for T1D and their discovery has advanced biological sciences by allowing for modification of cell fate and the development of higher-order cellular structures. They play an essential role in lowering levels of fasting blood sugar, hemoglobin A1c, and C-peptide, and in treating microvascular complications associated with T1D. However, some of the disadvantages of its use in clinical practice are limited to its method of collection, proliferation rate, cell activity with age, and the risk of tumour formation identified in some studies. Large-scale studies are required to discover the mechanism of action of MSCs after administration as well as the optimal route, dose, and timing to maximize the benefits to patients. This article focuses primarily on the role of MSCs in the treatment of T1D and compares the feasibility, benefits, and drawbacks of MSCs in the treatment of T1D. 

Extracellular vesicles for renal therapeutics: State of the art and future perspective

With the ever-increasing burden of kidney disease, the need for developing new therapeutics to manage this disease has never been greater. Extracellular vesicles (EVs) are natural membranous nanoparticles present in virtually all organisms. Given their excellent delivery capacity in the body, EVs have emerged as a frontier technology for drug delivery and have the potential to usher in a new era of nanomedicine for kidney disease. This review is focused on why EVs are such compelling drug carriers and how to release their fullest potentiality in renal therapeutics. We discuss the unique features of EVs compared to artificial nanoparticles and outline the engineering technologies and steps in developing EV-based therapeutics, with an emphasis on the emerging approaches to target renal cells and prolong kidney retention. We also explore the applications of EVs as natural therapeutics or as drug carriers in the treatment of renal disorders and present our views on the critical challenges in manufacturing EVs as next-generation renal therapeutics.

Diabetes complications and extracellular vesicle therapy

Diabetes is a chronic disorder characterized by dysregulated glycemic conditions. Diabetic complications include microvascular and macrovascular abnormalities and account for high morbidity and mortality rates in patients. Current clinical approaches for diabetic complications are limited to symptomatic treatments and tight control of blood sugar levels. Extracellular vesicles (EVs) released by somatic and stem cells have recently emerged as a new class of potent cell-free therapeutic delivery packets with a great potential to treat diabetic complications. EVs contain a mixture of bioactive molecules and can affect underlying pathological processes in favor of tissue healing. In addition, EVs have low immunogenicity and high storage capacity while maintaining nearly the same regenerative and immunomodulatory effects compared to current cell-based therapies. Therefore, EVs have received increasing attention for diabetes-related complications in recent years. In this review, we provide an outlook on diabetic complications and summarizes new knowledge and advances in EV applications. Moreover, we highlight recommendations for future EV-related research.

Extracellular vesicles in kidney disease

Extracellular vesicles are released by the majority of cell types and circulate in body fluids. They function as a long-distance cell-to-cell communication mechanism that modulates the gene expression profile and fate of target cells. Increasing evidence has established a central role of extracellular vesicles in kidney physiology and pathology. Urinary extracellular vesicles mediate crosstalk between glomerular and tubular cells and between different segments of the tubule, whereas circulating extracellular vesicles mediate organ crosstalk and are involved in the amplification of kidney damage and inflammation. The molecular profile of extracellular vesicles reflects the type and pathophysiological status of the originating cell so could potentially be exploited for diagnostic and prognostic purposes. In addition, robust preclinical data suggest that administration of exogenous extracellular vesicles could promote kidney regeneration and reduce inflammation and fibrosis in acute and chronic kidney diseases. Stem cells are thought to be the most promising source of extracellular vesicles with regenerative activity. Extracellular vesicles are also attractive candidates for drug delivery and various engineering strategies are being investigated to alter their cargo and increase their efficacy. However, rigorous standardization and scalable production strategies will be necessary to enable the clinical application of extracellular vesicles as potential therapeutics.

In this Review, the authors discuss the roles of extracellular vesicles in kidney physiology and disease as well as the beneficial effects of stem cell-derived extracellular vesicles in preclinical models of acute kidney injury and chronic kidney disease. They also highlight current and future clinical applications of extracellular vesicles in kidney diseases.

Urinary extracellular vesicles have roles in intra-glomerular, glomerulo-tubular and intra-tubular crosstalk, whereas circulating extracellular vesicles might mediate organ crosstalk; these mechanisms could amplify kidney damage and contribute to disease progression.

Urinary extracellular vesicles could potentially be analysed using multiplex diagnostic platforms to identify pathological processes and the originating cell types; technological advances including single extracellular vesicle analysis might increase the specificity of bulk analysis of extracellular vesicle preparations.

Robust standardization and validation in large patient cohorts are required to enable clinical application of extracellular vesicle-based biomarkers.

Stem cell-derived extracellular vesicles have been shown to improve renal recovery, limit progression of injury and reduce fibrosis in animal models of acute kidney injury and chronic kidney disease.

Various engineering approaches can be used to load extracellular vesicles with therapeutic molecules and increase their delivery to the kidney.

A small clinical trial that tested the efficacy of mesenchymal stem cell extracellular vesicle administration in patients with chronic kidney disease reported promising results; however, therapeutic application of extracellular vesicles is limited by a lack of scalable manufacturing protocols and clear criteria for standardization.

Extracellular Vesicles Released from Stem Cells as a New Therapeutic Strategy for Primary and Secondary Glomerulonephritis

Current treatment of primary and secondary glomerulopathies is hampered by many limits and a significant proportion of these disorders still evolves towards end-stage renal disease. A possible answer to this unmet challenge could be represented by therapies with stem cells, which include a variety of progenitor cell types derived from embryonic or adult tissues. Stem cell self-renewal and multi-lineage differentiation ability explain their potential to protect and regenerate injured cells, including kidney tubular cells, podocytes and endothelial cells. In addition, a broad spectrum of anti-inflammatory and immunomodulatory actions appears to interfere with the pathogenic mechanisms of glomerulonephritis. Of note, mesenchymal stromal cells have been particularly investigated as therapy for Lupus Nephritis and Diabetic Nephropathy, whereas initial evidence suggest their beneficial effects in primary glomerulopathies such as IgA nephritis. Extracellular vesicles mediate a complex intercellular communication network, shuttling proteins, nucleic acids and other bioactive molecules from origin to target cells to modulate their functions. Stem cell-derived extracellular vesicles recapitulate beneficial cytoprotective, reparative and immunomodulatory properties of parental cells and are increasingly recognized as a cell-free alternative to stem cell-based therapies for different diseases including glomerulonephritis, also considering the low risk for potential adverse effects such as maldifferentiation and tumorigenesis. We herein summarize the renoprotective potential of therapies with stem cells and extracellular vesicles derived from progenitor cells in glomerulonephritis, with a focus on their different mechanisms of actions. Technological progress and growing knowledge are paving the way for wider clinical application of regenerative medicine to primary and secondary glomerulonephritis: this multi-level, pleiotropic therapy may open new scenarios overcoming the limits and side effects of traditional treatments, although the promising results of experimental models need to be confirmed in the clinical setting.

Administration of mesenchymal stem cells in diabetic kidney disease: mechanisms, signaling pathways, and preclinical evidence

Diabetic kidney disease (DKD) is a serious microvascular complication of diabetes. Currently, the prevalence and mortality of DKD are increasing annually. However, with no effective drugs to prevent its occurrence and development, the primary therapeutic option is to control blood sugar and blood pressure. Therefore, new and effective drugs/methods are imperative to prevent the development of DKD in patients with diabetes. Mesenchymal stem cells (MSCs) with multi-differentiation potential and paracrine function have received extensive attention as a new treatment option for DKD. However, their role and mechanism in the treatment of DKD remain unclear, and clinical applications are still being explored. Given this, we here provide an unbiased review of recent advances in MSCs for the treatment of DKD in the last decade from the perspectives of the pathogenesis of DKD, biological characteristics of MSCs, and different molecular and signaling pathways. Furthermore, we summarize information on combination therapy strategies using MSCs. Finally, we discuss the challenges and prospects for clinical application.

Exposure to a mixture of heavy metals induces cognitive impairment: Genes and microRNAs involved

Converging evidence demonstrates that microRNAs (miRNAs) play an important role in the etiology of cognitive impairment. Thus, we aim to: (i) identify the molecular mechanisms of heavy metals, particularly miRNAs involved in the development of cognitive impairment; and (ii) generate miRNA sponges to prevent them from binding with their target messenger RNAs. The Comparative Toxicogenomics Database (CTD; http://ctd.mdibl.org), MicroRNA ENrichment TURned NETwork (MIENTURNET, http://userver.bio.uniroma1.it/apps/mienturnet/) and the microRNA sponge generator and tester (miRNAsong, http://www.med.muni.cz/histology/miRNAsong) were used as the core data-mining approaches in the current study. We observed that lead acetate, arsenic, gold, copper, iron, and aluminum, as well as their mixtures, had significant effects on the development of cognitive impairment. Although prevalent genes obtained from investigated heavy metals of cognitive impairment were different, the "PI3K-Akt signaling pathway", "pathways of neurodegeneration-multiple diseases", "apoptosis", "apoptosis-multiple species", "p53 signaling pathway", "NF-kappa B signaling pathway", and "Alzheimer's disease pathway" were highlighted. The mixed heavy metals altered the genes BAX, CASP3, BCL2, TNF, and IL-1B, indicating the significance of apoptosis and pro-inflammatory cytokines in the pathogenesis of cognitive impairment and the possibility of targeting these genes in future neuroprotective therapy. In addition, we used a network-based approach to identify key genes, miRNAs, pathways, and diseases related to the development of cognitive impairment. We also found 16 significant miRNAs related to cognitive impairment (hsa-miR-1-3p, hsa-let-7a-5p, hsa-miR-9-5p, hsa-miR-16-5p, hsa-miR-17-5p, hsa-miR-20a-5p, hsa-miR-26a-5p, hsa-miR-26b-5p, hsa-miR-34a-5p, hsa-miR-101-3p, hsa-miR-106a-5p, hsa-miR-128-3p, hsa-miR-144-3p, hsa-miR-199a-3p, hsa-miR-204-5p, and hsa-miR-335-5p). Finally, we created and evaluated miRNA sponge sequences for these miRNAs in silico. Further studies, including in vivo and in vitro, are needed to assess the link between these genes, miRNAs, pathways, and cognitive impairment.

Mechanisms of podocyte injury and implications for diabetic nephropathy

Albuminuria is the hallmark of both primary and secondary proteinuric glomerulopathies, including focal segmental glomerulosclerosis (FSGS), obesity-related nephropathy, and diabetic nephropathy (DN). Moreover, albuminuria is an important feature of all chronic kidney diseases (CKDs). Podocytes play a key role in maintaining the permselectivity of the glomerular filtration barrier (GFB) and injury of the podocyte, leading to foot process (FP) effacement and podocyte loss, the unifying underlying mechanism of proteinuric glomerulopathies. The metabolic insult of hyperglycemia is of paramount importance in the pathogenesis of DN, while insults leading to podocyte damage are poorly defined in other proteinuric glomerulopathies. However, shared mechanisms of podocyte damage have been identified. Herein, we will review the role of haemodynamic and oxidative stress, inflammation, lipotoxicity, endocannabinoid (EC) hypertone, and both mitochondrial and autophagic dysfunction in the pathogenesis of the podocyte damage, focussing particularly on their role in the pathogenesis of DN. Gaining a better insight into the mechanisms of podocyte injury may provide novel targets for treatment. Moreover, novel strategies for boosting podocyte repair may open the way to podocyte regenerative medicine.

Stem cell-derived and circulating exosomal microRNAs as new potential tools for diabetic nephropathy management

BACKGROUND

Despite major advances in the treatment of diabetic nephropathy (DN) in recent years, it remains the most common cause of end-stage renal disease. An early diagnosis and therapy may slow down the DN progression. Numerous potential biomarkers are currently being researched. Circulating levels of the kidney-released exosomes and biological molecules, which reflect the DN pathology including glomerular and tubular dysfunction as well as mesangial expansion and fibrosis, have shown the potential for predicting the occurrence and progression of DN. Moreover, many experimental therapies are currently being investigated, including stem cell therapy and medications targeting inflammatory, oxidant, or pro-fibrotic pathways activated during the DN progression. The therapeutic potential of stem cells is partly depending on their secretory capacity, particularly exosomal microRNAs (Exo-miRs). In recent years, a growing line of research has shown the participation of Exo-miRs in the pathophysiological processes of DN, which may provide effective therapeutic and biomarker tools for DN treatment.

METHODS

A systematic literature search was performed in MEDLINE, Scopus, and Google Scholar to collect published findings regarding therapeutic stem cell-derived Exo-miRs for DN treatment as well as circulating Exo-miRs as potential DN-associated biomarkers.

FINDINGS

Glomerular mesangial cells and podocytes are the most important culprits in the pathogenesis of DN and, thus, can be considered valuable therapeutic targets. Preclinical investigations have shown that stem cell-derived exosomes can exert beneficial effects in DN by transferring renoprotective miRs to the injured mesangial cells and podocytes. Of note, renoprotective Exo-miR-125a secreted by adipose-derived mesenchymal stem cells can improve the injured mesangial cells, while renoprotective Exo-miRs secreted by adipose-derived stem cells (Exo-miR-486 and Exo-miR-215-5p), human urine-derived stem cells (Exo-miR-16-5p), and bone marrow-derived mesenchymal stem cells (Exo-miR-let-7a) can improve the injured podocytes. On the other hand, clinical investigations have indicated that circulating Exo-miRs isolated from urine or serum hold great potential as promising biomarkers in DN.

Current understanding of the role of microRNAs from adipose-derived extracellular vesicles in obesity

Obesity and its associated metabolic diseases, including diabetes, insulin resistance, and inflammation, are rapidly becoming a global health concern. Moreover, obese individuals are more likely to be infected with COVID-19. New research on adipose tissue is required to help us understand these metabolic diseases and their regulatory processes. Recently, extracellular vesicles (EVs) have been identified as novel intercellular vectors with a wide range of regulatory functions. The miRNAs carried by EVs participate in the regulation of white adipose tissue (WAT) browning, insulin resistance, diabetes, and inflammation. In addition, EV miRNAs demonstrate great potential for helping elucidating the mechanism of metabolic diseases, and for advancing their prevention and treatment. In this review, we focus on the mechanisms underlying the regulation of adipose differentiation and metabolic diseases by adipose-derived EV miRNAs. Understanding the role of these miRNAs should enrich our understanding of the etiology and pathogenesis of metabolic diseases caused by obesity.