miR-196b-5p-enriched extracellular vesicles from tubular epithelial cells mediated aldosterone-induced renal fibrosis in mice with diabetes

Potential of Modulating Aldosterone Signaling and Mineralocorticoid Receptor with microRNAs to Attenuate Diabetic Kidney Disease

Diabetic Kidney Disease (DKD) is a significant complication of diabetes and primary cause of end-stage renal disease globally. The exact mechanisms underlying DKD remain poorly understood, but multiple factors, including the renin-angiotensin-aldosterone system (RAAS), play a key role in its progression. Aldosterone, a mineralocorticoid steroid hormone, is one of the key components of RAAS and a potential mediator of renal damage and inflammation in DKD. miRNAs, small noncoding RNA molecules, have attracted interest due to their regulatory roles in numerous biological processes. These processes include aldosterone signaling and mineralocorticoid receptor (MR) expression. Numerous miRNAs have been recognized as crucial regulators of aldosterone signaling and MR expression. These miRNAs affect different aspects of the RAAS pathway and subsequent molecular processes, which impact sodium balance, ion transport, and fibrosis regulation. This review investigates the regulatory roles of particular miRNAs in modulating aldosterone signaling and MR activation, focusing on their impact on kidney injury, inflammation, and fibrosis. Understanding the complex interaction between miRNAs and the RAAS could lead to a new strategy to target aldosterone signaling and MR activation using miRNAs. This highlights the potential of miRNA-based interventions for DKD, with the aim of enhancing kidney outcomes in individuals with diabetes.

Crosstalk between proximal tubular epithelial cells and other interstitial cells in tubulointerstitial fibrosis after renal injury

The energy needs of tubular epithelial components, especially proximal tubular epithelial cells (PTECs), are high and they heavily depend on aerobic metabolism. As a result, they are particularly vulnerable to various injuries caused by factors such as ischemia, proteinuria, toxins, and elevated glucose levels. Initial metabolic and phenotypic changes in PTECs after injury are likely an attempt at survival and repair. Nevertheless, in cases of recurrent or prolonged injury, PTECs have the potential to undergo a transition to a secretory state, leading to the generation and discharge of diverse bioactive substances, including transforming growth factor-β, Wnt ligands, hepatocyte growth factor, interleukin (IL)-1β, lactic acid, exosomes, and extracellular vesicles. By promoting fibroblast activation, macrophage recruitment, and endothelial cell loss, these bioactive compounds stimulate communication between epithelial cells and other interstitial cells, ultimately worsening renal damage. This review provides a summary of the latest findings on bioactive compounds that facilitate the communication between these cellular categories, ultimately leading to the advancement of tubulointerstitial fibrosis (TIF).

Cellular crosstalk of mesangial cells and tubular epithelial cells in diabetic kidney disease

Diabetic kidney disease (DKD) is a major cause of end-stage renal disease and imposes a heavy global economic burden; however, little is known about its complicated pathophysiology. Investigating the cellular crosstalk involved in DKD is a promising avenue for gaining a better understanding of its pathogenesis. Nonetheless, the cellular crosstalk of podocytes and endothelial cells in DKD is better understood than that of mesangial cells (MCs) and renal tubular epithelial cells (TECs). As the significance of MCs and TECs in DKD pathophysiology has recently become more apparent, we reviewed the existing literature on the cellular crosstalk of MCs and TECs in the context of DKD to acquire a comprehensive understanding of their cellular communication. Insights into the complicated mechanisms underlying the pathophysiology of DKD would improve its early detection, care, and prognosis. Video Abstract.

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.

MicroRNAs in aldosterone production and action

Aldosterone is a cardiovascular hormone with a key role in blood pressure regulation, among other processes, mediated through its targeting of the mineralocorticoid receptor in the renal tubule and selected other tissues. Its secretion from the adrenal gland is a highly controlled process subject to regulatory influence from the renin-angiotensin system and the hypothalamic-pituitary-adrenal axis. MicroRNAs are small endogenous non-coding RNA molecules capable of regulating gene expression post-transcriptionally through stimulation of mRNA degradation or suppression of translation. Several studies have now identified that microRNA levels are changed in cases of aldosterone dysregulation and that microRNAs are capable of regulating the expression of various genes involved in aldosterone production and action. In this article we summarise the major studies concerning this topic. We also discuss the potential role for circulating microRNAs as diagnostic biomarkers for primary aldosteronism, a highly treatable form of secondary hypertension, which would be highly desirable given the current underdiagnosis of this condition.

JAK/STAT signaling in diabetic kidney disease

Diabetic kidney disease (DKD) is the most important microvascular complication of diabetes and the leading cause of end-stage renal disease (ESRD) worldwide. The Janus kinase/signal transducer and activator of the transcription (JAK/STAT) signaling pathway, which is out of balance in the context of DKD, acts through a range of metabolism-related cytokines and hormones. JAK/STAT is the primary signaling node in the progression of DKD. The latest research on JAK/STAT signaling helps determine the role of this pathway in the factors associated with DKD progression. These factors include the renin-angiotensin system (RAS), fibrosis, immunity, inflammation, aging, autophagy, and EMT. This review epitomizes the progress in understanding the complicated explanation of the etiologies of DKD and the role of the JAK/STAT pathway in the progression of DKD and discusses whether it can be a potential target for treating DKD. It further summarizes the JAK/STAT inhibitors, natural products, and other drugs that are promising for treating DKD and discusses how these inhibitors can alleviate DKD to explore possible potential drugs that will contribute to formulating effective treatment strategies for DKD in the near future.

Extracellular vesicles: emerging roles, biomarkers and therapeutic strategies in fibrotic diseases

Extracellular vesicles (EVs), a cluster of cell-secreted lipid bilayer nanoscale particles, universally exist in body fluids, as well as cell and tissue culture supernatants. Over the past years, increasing attention have been paid to the important role of EVs as effective intercellular communicators in fibrotic diseases. Notably, EV cargos, including proteins, lipids, nucleic acids, and metabolites, are reported to be disease-specific and can even contribute to fibrosis pathology. Thus, EVs are considered as effective biomarkers for disease diagnosis and prognosis. Emerging evidence shows that EVs derived from stem/progenitor cells have great prospects for cell-free therapy in various preclinical models of fibrotic diseases and engineered EVs can improve the targeting and effectiveness of their treatment. In this review, we will focus on the biological functions and mechanisms of EVs in the fibrotic diseases, as well as their potential as novel biomarkers and therapeutic strategies.

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.

Long noncoding RNA FGD5-AS1 alleviates childhood IgA nephropathy by targeting PTEN-mediated JNK/c-Jun signaling pathway via miR-196b-5p

This paper studied lncRNA FGD5 antisense RNA 1 (FGD5-AS1)-associated mechanisms in immunoglobulin A nephropathy (IgAN). FGD5-AS1, miR-196b-5p, and PTEN in the serum of children with IgAN were assessed. MES-13 cells were stimulated by p-IgA1 to construct an in vitro model of IgAN. After plasmid intervention, cell proliferation, cell cycle, apoptosis, and inflammatory response were correspondingly evaluated. An IgAN mouse model was established to define FGD5-AS1/miR-196b-5p/PTEN axis-mediated alternations of 24-h proteinuria, blood urea nitrogen, serum creatinine, glomerular IgA deposition, renal fibrosis, and glycogen content in renal tissue. The changes in JNK/c-Jun pathway activation in the cell model were also tested. Our results discovered that FGD5-AS1 and PTEN were down-regulated and miR-196b-5p was up-regulated in children with IgAN. Overexpression of FGD5-AS1 or silencing of miR-196b-5p impeded the proliferation and inflammatory response and induced apoptosis of p-IgA1-stimulated MES-13 cells, and improved pathological conditions in IgAN mice. Inhibition of PTEN rescued the therapeutic effects of overexpression of FGD5-AS1 or inhibition of miR-196b-5p on IgAN. FGD5-AS1/miR-196b-5p/PTEN axis inhibited the activation of the JNK/c-Jun pathway. Taken together, FGD5-AS1 attenuates IgAN by targeting PTEN-mediated JNK/c-Jun signaling via miR-196b-5p. Therefore, FGD5-AS1 may be a new therapeutic target for IgAN.

Benefits of the Non-Steroidal Mineralocorticoid Receptor Antagonist Finerenone in Metabolic Syndrome-Related Heart Failure with Preserved Ejection Fraction

The mineralocorticoid receptor (MR) plays an important role in the development of chronic kidney disease (CKD) and associated cardiovascular complications. Antagonizing the overactivation of the MR with MR antagonists (MRA) is a therapeutic option, but their use in patients with CKD is limited due to the associated risk of hyperkalemia. Finerenone is a non-steroidal MRA associated with an improved benefit-risk profile in comparison to steroidal MRAs. In this study, we decided to test whether finerenone improves renal and cardiac function in male hypertensive and diabetic ZSF1 rats as an established preclinical HFpEF model. Finerenone was administered at 10 mg/kg/day for 12 weeks. Cardiac function/hemodynamics were assessed in vivo. ZSF1 rats showed classical signs of CKD with increased BUN, UACR, hypertrophy, and fibrosis of the kidney together with characteristic signs of HFpEF including cardiac fibrosis, diastolic dysfunction, and decreased cardiac perfusion. Finerenone treatment did not impact kidney function but reduced renal hypertrophy and cardiac fibrosis. Interestingly, finerenone ameliorated diastolic dysfunction and cardiac perfusion in ZSF1 rats. In summary, we show for the first time that non-steroidal MR antagonism by finerenone attenuates cardiac diastolic dysfunction and improves cardiac perfusion in a preclinical HFpEF model. These cardiac benefits were found to be largely independent of renal benefits.

Tackling the effects of extracellular vesicles in fibrosis

Fibrosis is a physiological process of tissue repair that turns into pathological when becomes chronic, damaging the functional structure of the tissue. In this review we outline the current status of extracellular vesicles as modulators of the fibrotic process at different levels. In adipose tissue, extracellular vesicles mediate the intercellular communication not only between adipocytes, but also between adipocytes and other cells of the stromal vascular fraction. Thus, they could be altering essential processes for the functionality of adipose tissue, such as adipocyte hypertrophy/hyperplasia, tissue plasticity, adipogenesis and/or inflammation, and ultimately trigger fibrosis. This process is particularly important in obesity, and may eventually, influence the development of obesity-associated alterations. In this regard, obesity is now recognized as an independent risk factor for the development of chronic kidney disease, although the role of extracellular vesicles in this connection has not been explored so far. Nonetheless, the role of extracellular vesicles in the onset and progression of renal fibrosis has been highlighted due to the critical role of fibrosis as a common feature of kidney diseases. In fact, the content of extracellular vesicles disturbs cellular signaling cascades involved in fibrosis in virtually all types of renal cells. What is certain is that the study of extracellular vesicles is complex, as their isolation and manipulation is still difficult to reproduce, which complicates the overview of their physiopathological effects. Nevertheless, new strategies have been developed to exploit the potential of extracellular vesicles and their cargo, both as biomarkers and as therapeutic tools to prevent the progression of fibrosis towards an irreversible event.

Cellular crosstalk of glomerular endothelial cells and podocytes in diabetic kidney disease

Diabetic kidney disease (DKD) is a serious microvascular complication of diabetes and is the leading cause of end-stage renal disease (ESRD). Persistent proteinuria is an important feature of DKD, which is caused by the destruction of the glomerular filtration barrier (GFB). Glomerular endothelial cells (GECs) and podocytes are important components of the GFB, and their damage can be observed in the early stages of DKD. Recently, studies have found that crosstalk between cells directly affects DKD progression, which has prospective research significance. However, the pathways involved are complex and largely unexplored. Here, we review the literature on cellular crosstalk of GECs and podocytes in the context of DKD, and highlight specific gaps in the field to propose future research directions. Elucidating the intricates of such complex processes will help to further understand the pathogenesis of DKD and develop better prevention and treatment options.

Primary Aldosteronism, Aldosterone, and Extracellular Vesicles

Primary aldosteronism (PA) is an endocrine related condition leading to arterial hypertension due to inappropriately high and unregulated aldosterone concentration. Recently, a broad spectrum of PA has been recognized, which brings new challenges associated with early identification of this condition that affect renal epithelial and extrarenal tissues. Reports have shown the potential role of extracellular vesicles (EVs) and EV cargo as novel and complementary biomarkers in diagnosis and prognosis of PA. In vivo and in vitro studies have identified specific EV surface antigens, EV-proteins, and EV microRNAs that can be useful to develop novel diagnostic algorithms to detect, confirm, or follow up the PA. Moreover, the study of EVs in the field of PA provides further insight in the pathophysiological mechanism of the PA disease.

Epigenetic modifications and the development of kidney graft fibrosis

PURPOSE OF REVIEW

To outline recent discoveries in epigenetic regulatory mechanisms that have potential implications in the development of renal fibrosis following kidney transplantation.

RECENT FINDINGS

The characterization of renal fibrosis following kidney transplantation has shown TGFβ/Smad signaling to play a major role in the progression to chronic allograft dysfunction. The onset of unregulated proinflammatory pathways are only exacerbated by the decline in regulatory mechanisms lost with progressive patient age and comorbidities such as hypertension and diabetes. However, significant developments in the recognition of epigenetic regulatory markers upstream of aberrant TGFβ-signaling has significant clinical potential to provide therapeutic targets for the treatment of renal fibrosis. In addition, discoveries in extracellular vesicles and the characterization of their cargo has laid new framework for the potential to evaluate patient outcomes independent of invasive biopsies.

SUMMARY

The current review summarizes the main findings in epigenetic machinery specific to the development of renal fibrosis and highlights therapeutic options that have significant potential to translate into clinical practice.

Chronic stress promotes glioma cell proliferation via the PI3K/Akt signaling pathway

High malignancy and high mortality of glioma render it urgent to elucidate the underlying mechanisms of glioma carcinogenesis and explore novel targets for therapy. Epidemiologic and clinical studies have revealed that chronic stress promotes the progression of various solid tumors and is correlated with poor prognosis; however, findings reporting the involvement of chronic stress in glioma are rare. In the present study, a chronic restraint animal model and a chronic stress cell model were established to explore the effects of chronic stress on glioma and its molecular mechanisms. The results revealed that chronic stress promoted glioma growth in vivo, and the serum levels of the stress hormones glucocorticoid (GC) and noradrenaline (NE) were significantly increased. In addition, GC and NE were verified to accelerate the proliferation of glioma cells in vitro. Mechanistically, the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway was revealed to be activated under stress conditions, and inhibition of the expression of p-Akt could restrain the stress hormone-induced glioma cell proliferation. In addition, our data indicated that the GC receptor (GR) and β-adrenergic receptors (ADRBs) were both required for the biological functions of GC and NE in glioma cells. In conclusion, these results indicated that chronic stress and the stress hormones GC and NE activated PI3K/Akt signaling through binding to GR and ADRBs, thereby promoting glioma cell growth. Our findings may provide potential therapeutic targets and pave the way for the development of new strategies to protect patients with glioma from the detrimental effects of stress on tumor progression.

Extracellular Vesicles in Organ Fibrosis: Mechanisms, Therapies, and Diagnostics

Fibrosis is the unrelenting deposition of excessively large amounts of insoluble interstitial collagen due to profound matrigenic activities of wound-associated myofibroblasts during chronic injury in diverse tissues and organs. It is a highly debilitating pathology that affects millions of people globally and leads to decreased function of vital organs and increased risk of cancer and end-stage organ disease. Extracellular vesicles (EVs) produced within the chronic wound environment have emerged as important vehicles for conveying pro-fibrotic signals between many of the cell types involved in driving the fibrotic response. On the other hand, EVs from sources such as stem cells, uninjured parenchymal cells, and circulation have in vitro and in vivo anti-fibrotic activities that have provided novel and much-needed therapeutic options. Finally, EVs in body fluids of fibrotic individuals contain cargo components that may have utility as fibrosis biomarkers, which could circumvent current obstacles to fibrosis measurement in the clinic, allowing fibrosis stage, progression, or regression to be determined in a manner that is accurate, safe, minimally-invasive, and conducive to repetitive testing. This review highlights the rapid and recent progress in our understanding of EV-mediated fibrotic pathogenesis, anti-fibrotic therapy, and fibrosis staging in the lung, kidney, heart, liver, pancreas, and skin.

Extracellular Vesicles and Renal Fibrosis: An Odyssey toward a New Therapeutic Approach

Renal fibrosis is a complex disorder characterized by the destruction of kidney parenchyma. There is currently no cure for this devastating condition. Extracellular vesicles (EVs) are membranous vesicles released from cells in both physiological and diseased states. Given their fundamental role in transferring biomolecules to recipient cells and their ability to cross biological barriers, EVs have been widely investigated as potential cell-free therapeutic agents. In this review, we provide an overview of EVs, focusing on their functional role in renal fibrosis and signaling messengers responsible for EV-mediated crosstalk between various renal compartments. We explore recent findings regarding the renoprotective effect of EVs and their use as therapeutic agents in renal fibrosis. We also highlight advantages and future perspectives of the therapeutic applications of EVs in renal diseases.

Exosome-derived miR-196b-5p facilitates intercellular interaction in infantile hemangioma via down-regulating CDKN1B

Background

Though infantile hemangioma (IH) is a common benign vascular tumor, its pathogenesis remains unclear. This study explored the function of hemangioma-derived stem cells (HemSCs) derived exosomes, which exerted an intercellular effect on hemangioma-derived endothelial cells (HemECs).

Methods

First, HemSCs and HemECs were extracted and cultured. HemSCs derived exosomes (HemSCs-exos) were harvested. miRNA sequencing and target prediction were used to explore differentially expressed miRNAs and potential binding targets. After HemECs were co-cultured with HemSCs-exos, a series of in vitro assays were then performed including cell counting kit-8 (CCK-8) assay, cell apoptosis assay, cell cycle assay and tube formation assay to evaluate proliferation, angiogenesis abilities, etc. qRT-PCR and Western blot were conducted to detect the expression level of target genes and proteins.

Results

After co-culturing with HemSCs-exos, proliferation, and angiogenesis abilities of HemECs were enhanced, while apoptosis and cell cycle arrest rate were decreased. MiR-196b-5p was observed to be significantly highly expressed in HemSCs-exos. CDKN1B was identified as the binding target of miR-196b-5p. HemECs' proliferation and angiogenesis abilities were elevated when co-cultured with exosomes from HemSCs transfected with miR-196b-5p mimic. In addition, apoptosis rate declined, and lower cells were arrested in G0/G1 phases. Cyclin E, bcl-2 were significantly highly expressed, whereas p27, Bax expression were significantly down-regulated. The positive effect of miR-196b-5p in HemSCs-exos was dramatically reversed when HemECs were transfected with oe-CDKN1B.

Conclusions

The current study found a novel intercellular interaction between IH cells. Briefly, exosome-derived miRNA-196b-5p in HemSCs could facilitate proliferation and angiogenesis abilities, and attenuate apoptosis and cell cycle repression rate of HemECs by directly binding with CDKN1B.

MicroRNA, Diabetes Mellitus and Colorectal Cancer

Diabetes mellitus (DM) is an endocrinological disorder that is due to either the pancreas not producing enough insulin, or the body does not respond appropriately to insulin. There are many complications of DM such as retinopathy, nephropathy, and peripheral neuropathy. In addition to these complications, DM was reported to be associated with different cancers. In this review, we discuss the association between DM and colorectal cancer (CRC). CRC is the third most commonly diagnosed cancer worldwide that mostly affects older people, however, its incidence and mortality are rising among young people. We discuss the relationship between DM and CRC based on their common microRNA (miRNA) biomarkers. miRNAs are non-coding RNAs playing important functions in cell differentiation, development, regulation of cell cycle, and apoptosis. miRNAs can inhibit cell proliferation and induce apoptosis in CRC cells. miRNAs also can improve glucose tolerance and insulin sensitivity. Therefore, investigating the common miRNA biomarkers of both DM and CRC can shed a light on how these two diseases are correlated and more understanding of the link between these two diseases can help the prevention of both DM and CRC.