E-cadherin expression is regulated by miR-192/215 by a mechanism that is independent of the profibrotic effects of transforming growth factor-beta

Understanding molecular mechanisms and miRNA-based targets in diabetes foot ulcers

In today's culture, obesity and overweight are serious issues that have an impact on how quickly diabetes develops and how it causes complications. For the development of more effective therapies, it is crucial to understand the molecular mechanisms underlying the chronic problems of diabetes. The most prominent effects of diabetes are microvascular abnormalities such as retinopathy, nephropathy, and neuropathy, especially diabetes foot ulcers, as well as macrovascular abnormalities such as heart disease and atherosclerosis. MicroRNAs (miRNAs), which are highly conserved endogenous short non-coding RNA molecules, have been implicated in several physiological functions recently, including the earliest stages of the disease. By binding to particular messenger RNAs (mRNAs), which cause mRNA degradation, translation inhibition, or even gene activation, it primarily regulates posttranscriptional gene expression. These molecules exhibit considerable potential as diagnostic biomarkers for disease and are interesting treatment targets. This review will provide an overview of the latest findings on the key functions that miRNAs role in diabetes and its complications, with an emphasis on the various stages of diabetic wound healing.

SIRT6's function in controlling the metabolism of lipids and glucose in diabetic nephropathy

Diabetic nephropathy (DN) is a complication of diabetes mellitus (DM) and the main cause of excess mortality in patients with type 2 DM. The pathogenesis and progression of DN are closely associated with disorders of glucose and lipid metabolism. As a member of the sirtuin family, SIRT6 has deacetylation, defatty-acylation, and adenosine diphosphate-ribosylation enzyme activities as well as anti-aging and anticancer activities. SIRT6 plays an important role in glucose and lipid metabolism and signaling, especially in DN. SIRT6 improves glucose and lipid metabolism by controlling glycolysis and gluconeogenesis, affecting insulin secretion and transmission and regulating lipid decomposition, transport, and synthesis. Targeting SIRT6 may provide a new therapeutic strategy for DN by improving glucose and lipid metabolism. This review elaborates on the important role of SIRT6 in glucose and lipid metabolism, discusses the potential of SIRT6 as a therapeutic target to improve glucose and lipid metabolism and alleviate DN occurrence and progression of DN, and describes the prospects for future research.

Potential roles of circulatory microRNAs in the onset and progression of renal and cardiac diseases: a focussed review for clinicians

The signalling mechanisms involving the kidney and heart are a niche of networks causing pathological conditions inducing inflammation, reactive oxidative species, cell apoptosis, and organ dysfunction during the onset of clinical complications. The clinical manifestation of the kidney and heart depends on various biochemical processes that influence organ dysfunction coexistence through circulatory networks, which hold utmost importance. The cells of both organs also influence remote communication, and evidence states that it may be explicitly by circulatory small noncoding RNAs, i.e. microRNAs (miRNAs). Recent developments target miRNAs as marker panels for disease diagnosis and prognosis. Circulatory miRNAs expressed in renal and cardiac disease can reveal relevant information about the niche of networks and gene transcription and regulated networks. In this review, we discuss the pertinent roles of identified circulatory miRNAs regulating signal transduction pathways critical in the onset of renal and cardiac disease, which can hold promising future targets for clinical diagnostic and prognostic purposes.

Capturing the Kidney Transcriptome by Urinary Extracellular Vesicles-From Pre-Analytical Obstacles to Biomarker Research

Urinary extracellular vesicles (uEV) hold non-invasive RNA biomarkers for genitourinary tract diseases. However, missing knowledge about reference genes and effects of preanalytical choices hinder biomarker studies. We aimed to assess how preanalytical variables (urine storage temperature, isolation workflow) affect diabetic kidney disease (DKD)-linked miRNAs or kidney-linked miRNAs and mRNAs (kidney-RNAs) in uEV isolates and to discover stable reference mRNAs across diverse uEV datasets. We studied nine raw and normalized sequencing datasets including healthy controls and individuals with prostate cancer or type 1 diabetes with or without albuminuria. We focused on kidney-RNAs reviewing literature for DKD-linked miRNAs from kidney tissue, cell culture and uEV/urine experiments. RNAs were analyzed by expression heatmaps, hierarchical clustering and selecting stable mRNAs with normalized counts (>200) and minimal coefficient of variation. Kidney-RNAs were decreased after urine storage at -20 °C vs. -80 °C. Isolation workflows captured kidney-RNAs with different efficiencies. Ultracentrifugation captured DKD -linked miRNAs that separated healthy and diabetic macroalbuminuria groups. Eleven mRNAs were stably expressed across the datasets. Hence, pre-analytical choices had variable effects on kidney-RNAs-analyzing kidney-RNAs complemented global correlation, which could fade differences in some relevant RNAs. Replicating prior DKD-marker results and discovery of candidate reference mRNAs encourages further uEV biomarker studies.

Single-cell RNA-seq with spatial transcriptomics to create an atlas of human diabetic kidney disease

Diabetic kidney disease (DKD) develops in ~40% of patients with diabetes and is the leading cause of chronic kidney disease worldwide. We used single-cell RNA-sequencing and spatial transcriptomic analyses of kidney specimens from patients with DKD. Unsupervised clustering revealed distinct cell clusters, including epithelial cells and fibroblasts. We also identified differentially expressed genes (DEGs) and assessed enrichment, and cell-cell interactions. Specific enrichment of DKD was evident in venous endothelial cells (VECs) and fibroblasts with elevated CCL19 expression. The DEGs in most kidney parenchymal cells in DKD were primarily enriched in inflammatory signaling pathways. Intercellular crosstalk revealed that most cell interactions in DKD are associated with chemokines. Spatial transcriptomics revealed that VECs co-localized with fibroblasts, with most immune cells being enriched in areas of renal fibrosis. These results provided insight into the cell populations, intercellular interactions, and signaling pathways underlying the pathogenesis and potential targets for treating DKD.

Kidney fibrosis: from mechanisms to therapeutic medicines

Chronic kidney disease (CKD) is estimated to affect 10-14% of global population. Kidney fibrosis, characterized by excessive extracellular matrix deposition leading to scarring, is a hallmark manifestation in different progressive CKD; However, at present no antifibrotic therapies against CKD exist. Kidney fibrosis is identified by tubule atrophy, interstitial chronic inflammation and fibrogenesis, glomerulosclerosis, and vascular rarefaction. Fibrotic niche, where organ fibrosis initiates, is a complex interplay between injured parenchyma (like tubular cells) and multiple non-parenchymal cell lineages (immune and mesenchymal cells) located spatially within scarring areas. Although the mechanisms of kidney fibrosis are complicated due to the kinds of cells involved, with the help of single-cell technology, many key questions have been explored, such as what kind of renal tubules are profibrotic, where myofibroblasts originate, which immune cells are involved, and how cells communicate with each other. In addition, genetics and epigenetics are deeper mechanisms that regulate kidney fibrosis. And the reversible nature of epigenetic changes including DNA methylation, RNA interference, and chromatin remodeling, gives an opportunity to stop or reverse kidney fibrosis by therapeutic strategies. More marketed (e.g., RAS blockage, SGLT2 inhibitors) have been developed to delay CKD progression in recent years. Furthermore, a better understanding of renal fibrosis is also favored to discover biomarkers of fibrotic injury. In the review, we update recent advances in the mechanism of renal fibrosis and summarize novel biomarkers and antifibrotic treatment for CKD.

miRNA-encapsulated abiotic materials and biovectors for cutaneous and oral wound healing: Biogenesis, mechanisms, and delivery nanocarriers

MicroRNAs (miRNAs) as therapeutic agents have attracted increasing interest in the past decade owing to their significant effectiveness in treating a wide array of ailments. These polymerases II-derived noncoding RNAs act through post-transcriptional controlling of different proteins and their allied pathways. Like other areas of medicine, researchers have utilized miRNAs for managing acute and chronic wounds. The increase in the number of patients suffering from either under-healing or over-healing wound demonstrates the limited efficacy of the current wound healing strategies and dictates the demands for simpler approaches with greater efficacy. Various miRNA can be designed to induce pathway beneficial for wound healing. However, the proper design of miRNA and its delivery system for wound healing applications are still challenging due to their limited stability and intracellular delivery. Therefore, new miRNAs are required to be identified and their delivery strategy needs to be optimized. In this review, we discuss the diverse roles of miRNAs in various stages of wound healing and provide an insight on the most recent findings in the nanotechnology and biomaterials field, which might offer opportunities for the development of new strategies for this chronic condition. We also highlight the advances in biomaterials and delivery systems, emphasizing their challenges and resolutions for miRNA-based wound healing. We further review various biovectors (e.g., adenovirus and lentivirus) and abiotic materials such as organic and inorganic nanomaterials, along with dendrimers and scaffolds, as the delivery systems for miRNA-based wound healing. Finally, challenges and opportunities for translation of miRNA-based strategies into clinical applications are discussed.

Modulation of miR-192/NF-κB/ TGF-β/ E-cadherin by thymoquinone protects against diethylnitrosamine /carbon tetrachloride hepatotoxicity

Scientific efforts have been made for a better understanding of the pathogenesis of hepatocellular carcinoma (HCC). We investigated the possible role of miR-192/nuclear factor-κB (NF-κB)/transforming growth factor-β (TGF-β)/E-cadherin in hepatic tumorigenesis. We expected a modulatory impact of thymoquinone. Thirty adult male rats were assigned into 3 groups (n = 10); (1) Control group. Group (2): Experimental HCC induced by intraperitoneal injection of diethylnitrosamine (DENA) followed by carbon tetrachloride (CCl4). Group (3): Thymoquinone 20 mg kg-1/oral supplementation starting from the model induction to the end of the 8th week. The HCC (DENA-CCL4) model was confirmed by elevated serum levels of alpha-fetoprotein and transaminases (ALT, AST) and by histopathological examination which denoted marked cellular atypia and features of neoplasia. Suppressed hepatic miR-192 and E-cadherin expression were detected in the HCC (DENA-CCL4) group accompanied by elevated tumor necrosis factor (TNF-α), interleukin (IL6)/NF-κB & TGF-β1. Thymoquinone treatment protected the rat livers from hepatic tumorigenesis. Thymoquinone diminished (P < 0.001) alpha-fetoprotein and improved ALT, AST. It preserved hepatic miR-192 and normal E-cadherin expression. Thymoquinone-treated rats showed abrogated TNF-α, IL6/NF-κB/TGF-β. Thymoquinone increased cell apoptosis markers Bax/Bcl2 and diminished cellular atypia. Pearson's correlations revealed positive association between miR-192 expression and E-cadherin and Bax/Bcl2 as well, and it was negatively correlated to alpha-fetoprotein, NF-κB and TGF-β and the cellular atypia score. In conclusion, thymoquinone protected the liver tissues through preserving miR-192 and E-cadherin and aborting NF-κB & TGF-β signaling. The current results highlight a new role for thymoquinone in preventing hepatic tumorigenesis.

Lipid-Based Nanocarriers in Renal RNA Therapy

Kidney disease is a multifactorial problem, with a growing prevalence and an increasing global burden. With the latest worldwide data suggesting that chronic kidney disease (CKD) is the 12th leading cause of death, it is no surprise that CKD remains a public health problem that requires urgent attention. Multiple factors contribute to kidney disease, each with its own pathophysiology and pathogenesis. Furthermore, microRNAs (miRNAs) have been linked to several types of kidney diseases. As dysregulation of miRNAs is often seen in some diseases, there is potential in the exploitation of this for therapeutic applications. In addition, uptake of interference RNA has been shown to be rapid in kidneys making them a good candidate for RNA therapy. The latest advancements in RNA therapy and lipid-based nanocarriers have enhanced the effectiveness and efficiency of RNA-related drugs, thereby making RNA therapy a viable treatment option for renal disease. This is especially useful for renal diseases, for which a suitable treatment is not yet available. Moreover, the high adaptability of RNA therapy combined with the low risk of lipid-based nanocarriers make for an attractive treatment choice. Currently, there are only a small number of RNA-based drugs related to renal parenchymal disease, most of which are in different stages of clinical trials. We propose the use of miRNAs or short interfering RNAs coupled with a lipid-based nanocarrier as a delivery vehicle for managing renal disease.

Advances in the Progression and Prognosis Biomarkers of Chronic Kidney Disease

Chronic kidney disease (CKD) is one of the increasingly serious public health concerns worldwide; the global burden of CKD is increasingly due to high morbidity and mortality. At present, there are three key problems in the clinical treatment and management of CKD. First, the current diagnostic indicators, such as proteinuria and serum creatinine, are greatly interfered by the physiological conditions of patients, and the changes in the indicator level are not synchronized with renal damage. Second, the established diagnosis of suspected CKD still depends on biopsy, which is not suitable for contraindication patients, is also traumatic, and is not sensitive to early progression. Finally, the prognosis of CKD is affected by many factors; hence, it is ineviatble to develop effective biomarkers to predict CKD prognosis and improve the prognosis through early intervention. Accurate progression monitoring and prognosis improvement of CKD are extremely significant for improving the clinical treatment and management of CKD and reducing the social burden. Therefore, biomarkers reported in recent years, which could play important roles in accurate progression monitoring and prognosis improvement of CKD, were concluded and highlighted in this review article that aims to provide a reference for both the construction of CKD precision therapy system and the pharmaceutical research and development.

Epigenetics in the pathogenesis of diabetic nephropathy

Diabetic nephropathy (DN), which is a common microvascular complication with a high incidence in diabetic patients, greatly increases the mortality of patients. With further study on DN, it is found that epigenetics plays a crucial role in the pathophysiological process of DN. Epigenetics has an important impact on the development of DN through a variety of mechanisms, and promotes the generation and maintenance of metabolic memory, thus ultimately leading to a poor prognosis. In this review we discuss the methylation of DNA, modification of histone, and regulation of non-coding RNA involved in the progress of cell dysfunction, inflammation and fibrosis in the kidney, which ultimately lead to the deterioration of DN.

Fetal Undernutrition Programming, Sympathetic Nerve Activity, and Arterial Hypertension Development

A wealth of evidence showed that low birth weight is associated with environmental disruption during gestation, triggering embryotic or fetal adaptations and increasing the susceptibility of progeny to non-communicable diseases, including metabolic and cardiovascular diseases, obesity, and arterial hypertension. In addition, dietary disturbance during pregnancy in animal models has highlighted mechanisms that involve the genesis of arterial hypertension, particularly severe maternal low-protein intake (LP). Functional studies demonstrated that maternal low-protein intake leads to the renal decrease of sodium excretion and the dysfunction of the renin-angiotensin-aldosterone system signaling of LP offspring. The antinatriuretic effect is accentuated by a reduced number of nephron units and glomerulosclerosis, which are critical in establishing arterial hypertension phenotype. Also, in this way, studies have shown that the overactivity of the central and peripheral sympathetic nervous system occurs due to reduced sensory (afferent) renal nerve activity. As a result of this reciprocal and abnormal renorenal reflex, there is an enhanced tubule sodium proximal sodium reabsorption, which, at least in part, contributes directly to arterial hypertension development in some of the programmed models. A recent study has observed that significant changes in adrenal medulla secretion could be involved in the pathophysiological process of increasing blood pressure. Thus, this review aims to compile studies that link the central and peripheral sympathetic system activity mechanisms on water and salt handle and blood pressure control in the maternal protein-restricted offspring. Besides, these pathophysiological mechanisms mainly may involve the modulation of neurokinins and catecholamines pathways.

KLF5 regulates epithelial-mesenchymal transition of liver cancer cells in the context of p53 loss through miR-192 targeting of ZEB2

Krüppel-like factor 5 (KLF5) can both promote and suppress cell migration, but the underlying mechanisms have not been elucidated. In this study, we show that the function of KLF5 in epithelial-mesenchymal transition (EMT) and migration of liver cancer cells depends on the status of the cellular tumor antigen p53 (p53). Furthermore, zinc finger E-box-binding homeobox 2 (ZEB2) is the main regulator of KLF5 in EMT in liver cancer cells in the context of p53 loss. Most importantly, the regulation of ZEB2 by p53 and KLF5 is indirect and that miR-192 mediates this regulation. Finally, we find that in invasive liver cancer, KLF5 is absent in the context of p53 loss or mutation.

The synergistic protection of EGCG and quercetin against streptozotocin (STZ)-induced NIT-1 pancreatic β cell damage via upregulation of BCL-2 expression by miR-16-5p

EGCG and quercetin are flavonoids which usually co-exist in edible plants and they exhibit anti-diabetes effects. This study aimed to explore the mechanisms by which quercetin and EGCG synergistically protected pancreatic β-cells from streptozotocin-induced apoptosis. EGCG, quercetin, and their combinations (both 15 μM) all reversed STZ-induced cells damage and enhanced glucose-stimulated insulin secretion, with the combination being more effective than a single compound. At the molecular level, the EGCG-quercetin combination upregulated BCL-2 expression and caused a greater reduction in miR-16-5p level than EGCG alone or quercetin alone. Overexpression of miR-16-5p could offset the down-regulated apoptotic genes caused by the synergistic action of the combination. These findings suggest that EGCG and quercetin exert synergistic anti-diabetes effect, possibly via decreasing the expression of miR-16-5p that targets directly BCL-2. This is the first report on a miRNA-based mechanism underlying the synergistic protective effect of EGCG and quercetin against pancreatic cell damage.

Gestational and Breastfeeding Low-Protein Intake on Blood Pressure, Kidney Structure, and Renal Function in Male Rat Offspring in Adulthood

Background: Our previous studies demonstrated that maternal protein-restricted (low-protein, LP) 16-week-old offspring had pronounced nephron number reduction and arterial hypertension associated with an unchanged glomerular filtration rate (GFR). An enhanced gomerular area may be related to increased glomerular filtration and overflow, which accounts for glomerular filtration barrier breakdown and early glomerulosclerosis. The effect of protein restriction during gestational and breastfeeding periods is unknown. Method: The functional e-structural kidney evaluation was obtained using lithium and creatinine clearance, kidney morphometry, immunoblotting, and immunostaining analysis in 16 and 24-week-old LP offspring compared to age-matched NP progeny. Results: Low protein rats' progeny had significantly reduced birth weight, without previous catch-up growth phenomena, in parallel with a decreased adiposity index. Transforming growth factor-beta 1 (TGF-β1) glomerular expression was significantly enhanced in the LP group. Also, the LP offspring had a 38% lower nephron number and an increased glomerular volume. They also presented with a higher cardiac index and arterial blood pressure compared with age-matched NP offspring. The LP rats exhibited augmented Na+/K+-ATPase in the proximal segments, and NOS1 immunoreactivity in whole renal tissue was associated with sodium retention in the proximal nephron segments. We also found significantly enhanced collagen content associated with increased TGFβ1 and ZEB1/2 renal immunoreactivity in LP offspring compared with NP offspring. Increased hypertrophy markers in LP podocytes were associated with an amplified IL-6/STAT3 pathway activity. Conclusion: To our knowledge, these are the first data demonstrating renal functional and structural changes in protein restriction during gestation and lactation model of fetal programming. The fetal-programmed adult offspring showed pronounced structural glomerular disorders with an accentuated and advanced fibrosis stage, without a change in the GFR. These findings suggest that the glomerular enhanced TGF-β1 action may induce ZEB1/2 expression that may cause glomeruli epithelial-to-mesenchymal transition. Besides, decreased nephron number in the LP offspring with preserved glomerular function may be related to protective or even attenuate the activated IL-6/STAT3 pathway.

Exosomes derived from human adipose mesenchymal stem cells attenuate hypertrophic scar fibrosis by miR-192-5p/IL-17RA/Smad axis

BACKGROUND

Hypertrophic scar (HS) is a fibro-proliferative disorder of dermis after burn or trauma and usually leads to esthetic disfiguration and functionary impairment for patients. Emerging evidences demonstrated ADSC-Exo could alleviate the visceral fibrosis, but little attention had been paid to its role in skin fibrosis. In the study, we would explore the effect of ADSC-Exo on HS and investigated the exact mechanism underlying the properties.

METHODS

ADSC-Exo were isolated, identified, and internalized by HS-derived fibroblasts (HSFs). The effect of ADSC-Exo on the proliferation and migration of HSFs were detected by flow cytometry and Ki67 immunofluorescence staining, or scratch and trans-wells assays, respectively. RT-PCR, immunoblotting, immunofluorescence, and immunohistochemistry staining were used to evaluate the expression of IL-17RA, Col1, Col3, α-SMA, SIP1, and p-Smad2/p-Smad3 in HSFs stimulated with ADSC-Exo, miR-192-5p mimics, or inhibitors, IL-17RA siRNA and their negative controls. Digital morphology, H&E, Masson's trichrome staining, and immunohistochemistry staining were performed to measure the effect of ADSC-Exo and Lv-IL-17RA shRNA on excisional wound of BALB/c mice.

RESULTS

The verified ADSC-Exo effectively inhibited the proliferation and migration of HSFs, decreased the expression of Col1, Col3, α-SMA, IL-17RA, and p-Smad2/p-Smad3 and increased the levels of SIP1 in HSFs. Besides, the mice in ADSC-Exo-treated group demonstrated faster wound healing and less collagen deposition. Furthermore, miR-192-5p was highly expressed in ADSC-Exo and ADSC-Exosomal miR-192-5p ameliorated hypertrophic scar fibrosis. Meanwhile, miR-192-5p targeted the expression of IL-17RA to decrease the pro-fibrotic proteins levels. Moreover, IL-17RA was overexpressed in HS and HSFs, and knockdown IL-17RA alleviated the expression of Col1, Col3, α-SMA, and p-Smad2/p-Smad3 and increased the expression of SIP1 in HSFs. Most importantly, IL-17RA silence also facilitated wound healing, attenuated collagen production, and modulated Smad pathway in HSFs.

CONCLUSIONS

This study illustrated ADSC-Exo attenuated the deposition of collagen, the trans-differentiation of fibroblasts-to-myofibroblasts, and the formation of hypertrophic scar by in vitro and in vivo experiments. ADSC-Exosomal miR-192-5p targeted IL-17RA to regulate Smad pathway in hypertrophic scar fibrosis. ADSC-Exo could be a promising therapeutic strategy for clinical treatment of hypertrophic scar and the anti-fibrotic properties could be achieved by miR-192-5p/IL-17RA/Smad axis.

Non-Coding RNA and Diabetic Kidney Disease

Diabetic kidney disease (DKD) is one of the most common chronic microvascular complications of diabetes. In addition to the characteristic clinical manifestations of proteinuria, it also has a complex pathological process that results from the combined effects of multiple factors involving the whole renal structure such as glomeruli, renal tubules, and blood vessels. Non-coding RNAs (ncRNA) are transcripts with no or low coding potential, among which micro RNA (miRNA) has been widely studied as a functional miRNA involved in regulation and a potential biomarker for disease prediction. The abundance of long coding RNA (lncRNA) in vivo is highly expressed with a certain degree of research progress, but the structural similarity makes the research still challenging. The research of circular RNA (circRNA) is still in its early stages. It is more relevant to the study to provide a more relevant link between diseases in the kidney and other tissues or organs. This classification review mainly summarized the biogenesis characteristics, the pathological mechanism of ncRNA-regulating diseases, the ways of ncRNA in the clinical prediction as a potential biomarker, and the interaction networks of ncRNA.

Comparison of Snail1, ZEB1, E-Cadherin Expression Levels in HPV-Induced Cervical Cancer

Background:

Molecular profiling techniques are the rapid detection of biomarkers in the human papillomavirus (HPV) infected cells. We aimed to measure the expression level of three cell factors including Snail1, ZEB-1, and E-cadherin in cervical cancer (CC), precancerous and healthy samples, simultaneously, to find potential biomarkers.

Methods:

The expression level of the mentioned cell factors were investigated in 72 CC patients, precancerous patients, and healthy controls by using Real-Time PCR.

Results:

The results demonstrated a significant reduction in the expression level of E-cadherin in cancer and precancerous cases than that in healthy cases; whereas the expression level of ZEB-1 and Snail1 were upregulated in cancer and precancerous samples. The receiver operating characteristic (ROC) analyses shows the highest AUC value emerged for Snail1: 1(95% CI: 1-1) in comparing CC and healthy groups with a sensitivity of 100.0 % and specificity of 100.0%.

Conclusion:

The molecular biomarker Snail1 may be helpful to early diagnosis and prognosis of CC in the HPV-infected human populations. Considering the increased expression level of Snail1 in cancer and precancerous tissue compared to healthy tissue as well as the area under the ROC curve, Snail1 can be used for early detection of CC.

Intratumoral Fibrosis in Facilitating Renal Cancer Aggressiveness: Underlying Mechanisms and Promising Targets

Intratumoral fibrosis is a histologic manifestation of fibrotic tumor stroma. The interaction between cancer cells and fibrotic stroma is intricate and reciprocal, involving dysregulations from multiple biological processes. Different components of tumor stroma are implicated via distinct manners. In the kidney, intratumoral fibrosis is frequently observed in renal cell carcinoma (RCC). However, the underlying mechanisms remain largely unclear. In this review, we recapitulate evidence demonstrating how fibrotic stroma interacts with cancer cells and mechanisms shared between RCC tumorigenesis and renal fibrogenesis, providing promising targets for future studies.

Human Adipose Mesenchymal Stem Cell-Derived Exosomes: A Key Player in Wound Healing

BACKGROUND

Human adipose-derived mesenchymal stem cells (AMSCs) are an attractive resource for wound healing because their regenerative capacity improves injury repair. Recently, stem cell-derived exosomes have been shown to play a positive role in stem cell-based therapies. However, the effects of exosomes derived from AMSCs (AEXOs) on wound healing are unclear. In this study, we aimed to examine the role of AEXOs in attenuating inflammation and explore their effects in normal wound healing.

METHODS

We isolated exosomes from AMSCs and established a cellular model of inflammation by treatment with the inflammatory cytokines, interferon gamma and tumor necrosis factor alpha, to determine whether AEXOs can inhibit inflammation. We examined the wound healing effects of AEXOs in in vitro wound healing models and performed a miRNA array to understand the role of AEXOs in inflammation and wound healing.

RESULTS

A significant difference was observed in wound closure and the expression of anti-inflammatory and wound-healing-related factors between control and AEXO-treated cells.

CONCLUSION

Our results showed that besides alleviating the inflammation response, AEXOs also promote wound healing. Thus, AEXOs represent a novel, stem-cell-based, therapeutic strategy for wound healing.

Fibrosis in Chronic Kidney Disease: Pathogenesis and Consequences

Fibrosis is a process characterized by an excessive accumulation of the extracellular matrix as a response to different types of tissue injuries, which leads to organ dysfunction. The process can be initiated by multiple and different stimuli and pathogenic factors which trigger the cascade of reparation converging in molecular signals responsible of initiating and driving fibrosis. Though fibrosis can play a defensive role, in several circumstances at a certain stage, it can progressively become an uncontrolled irreversible and self-maintained process, named pathological fibrosis. Several systems, molecules and responses involved in the pathogenesis of the pathological fibrosis of chronic kidney disease (CKD) will be discussed in this review, putting special attention on inflammation, renin-angiotensin system (RAS), parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), Klotho, microRNAs (miRs), and the vitamin D hormonal system. All of them are key factors of the core and regulatory pathways which drive fibrosis, having a great negative kidney and cardiac impact in CKD.

Systemic inhibition of miR-451 increases fibrotic signaling and diminishes autophagic response to exacerbate renal damage in Tallyho/Jng mice

miRNAs provide fine tuning of gene expression via inhibition of translation. miR-451 has a modulatory role in cell cycling via downregulation of mechanistic target of rapamycin. We aimed to test whether chronic systemic inhibition of miR-451 would enhance renal fibrosis (associated with deranged autophagy). Adult TallyHo/Jng mice (obese insulin resistant) were randomized to two treatment groups to receive either miR-451 inhibition [via a locked nucleic acid construct] or a similar scrambled locked nucleic acid control for 8 wk. All mice were fed a high-fat diet (60% kcal from fat) ad libitum and humanely euthanized after 12 wk. Kidneys and blood were collected for analysis. Renal expression of miR-451 was sixfold lower in inhibitor-treated mice compared with control mice. miR-451 inhibition increased kidney weight and collagen and glycogen deposition. Blood chemistry revealed significantly higher Na⁺ and anion gap (relative metabolic acidosis) in inhibitor-treated mice. Western blot analysis and immunohistochemistry of the kidney revealed that the inhibitor increased markers of renal injury and fibrosis, e.g., kidney injury molecule 1, neutrophil gelatinase-associated lipocalin, transforming growth factor-β, 14-3-3 protein-ζ, mechanistic target of rapamycin, AMP-activated protein kinase-α, calcium-binding protein 39, matrix metallopeptidase-9, and the autophagy receptor sequestosome 1. In contrast, the inhibitor reduced the epithelial cell integrity marker collagen type IV and the autophagy markers microtubule-associated protein 1A/1B light chain 3B and beclin-1. Taken together, these results support a protective role for miR-451 in reducing renal fibrosis by enhancing autophagy in obese mice.

miR-192-5p suppresses uterine receptivity formation through impeding epithelial transformation during embryo implantation

The establishment of uterine receptivity is a prerequisite for embryo implantation and begins with the transformation of the luminal epithelium. MicroRNAs (miRNAs) have been widely reported to be involved in the regulation of embryo implantation, but their roles in establishing uterine receptivity remain unclear. In this study, through small RNA sequencing analysis, we showed that a low level of miR-192-5p is essential for initiating implantation in mice, and transient upregulation of miR-192-5p led to implantation failure. In situ hybridization results revealed that miR-192-5p was primarily expressed in the endometrial epithelium, and dysregulation of miR-192-5p interfered with the performance of the luminal epithelium, resulting in inadequate receptivity. By manipulating miR-192-5p expression in mouse uterus and an endometrial epithelial cell line, we showed that miR-192-5p maintains cell polarity through stabilizing adherens junction protein E-cadherin, thereby preventing epithelial-mesenchymal transition. Furthermore, miR-192-5p preserved the pattern of microvilli as well as Muc1 expression on the apical membrane of epithelial cells, thereby avoiding embryo adhesion. Moreover, miR-192-5p was found to be regulated by ovarian steroids. Collectively, this study demonstrated that the physiological role of miR-192-5p in mouse uterus is to maintain the nonreceptive state of epithelial cells and prevent their transformation to the receptive state. Thus, a sustained high level of miR-192-5p is detrimental to embryo implantation. These findings help elucidate the mechanisms involved in miRNA-based regulation of uterine physiology in early pregnancy, and may even contribute to the diagnosis and treatment of infertility.

Exploring microRNAs in diabetic chronic cutaneous ulcers: Regulatory mechanisms and therapeutic potential

Diabetic chronic cutaneous ulcers (DCU) are one of the serious complications of diabetes mellitus, occurring mainly in diabetic patients with peripheral neuropathy. Recent studies have indicated that microRNAs (miRNAs/miRs) and their target genes are essential regulators of cell physiology and pathology including biological processes that are involved in the regulation of diabetes and diabetes-related microvascular complications. in vivo and in vitro models have revealed that the expression of some miRNAs can be regulated in the inflammatory response, cell proliferation, and wound remodelling of DCU. Nevertheless, the potential application of miRNAs to clinical use is still limited. Here, we provide a contemporary overview of the miRNAs as well as their associated target genes and pathways (including Wnt/β-catenin, NF-κB, TGF-β/Smad, and PI3K/AKT/mTOR) related to DCU healing. We also summarize the current development of drugs for DCU treatment and discuss the therapeutic challenges of DCU treatment and its future research directions.

The Non-coding Side of Medulloblastoma

Medulloblastoma (MB) is the most common pediatric brain tumor and a primary cause of cancer-related death in children. Until a few years ago, only clinical and histological features were exploited for MB pathological classification and outcome prognosis. In the past decade, the advancement of high-throughput molecular analyses that integrate genetic, epigenetic, and expression data, together with the availability of increasing wealth of patient samples, revealed the existence of four molecularly distinct MB subgroups. Their further classification into 12 subtypes not only reduced the well-characterized intertumoral heterogeneity, but also provided new opportunities for the design of targets for precision oncology. Moreover, the identification of tumorigenic and self-renewing subpopulations of cancer stem cells in MB has increased our knowledge of its biology. Despite these advancements, the origin of MB is still debated, and its molecular bases are poorly characterized. A major goal in the field is to identify the key genes that drive tumor growth and the mechanisms through which they are able to promote tumorigenesis. So far, only protein-coding genes acting as oncogenic drivers have been characterized in each MB subgroup. The contribution of the non-coding side of the genome, which produces a plethora of transcripts that control fundamental biological processes, as the cell choice between proliferation and differentiation, is still unappreciated. This review wants to fill this major gap by summarizing the recent findings on the impact of non-coding RNAs in MB initiation and progression. Furthermore, their potential role as specific MB biomarkers and novel therapeutic targets is also highlighted.

Kaempferol in ameliorating diabetes-induced fibrosis and renal damage: An in vitro and in vivo study in diabetic nephropathy mice model

BACKGROUND

Kaempferol is a natural polyflavonol that has gained considerable attention as antidiabetic therapeutics. Recent reports emphasize the role of hyperglycemia and RhoA/Rho Kinase activity in the pathogenesis of diabetic nephropathy (DN). This study aims to evaluate the GLP-1 and insulin release along with RhoA/Rho Kinase inhibition pertaining to the anti-fibrotic and reno-protective effects of Kaempferol in DN.

METHODS

The effect of Kaempferol on GLP-1 and insulin release along with underlying mechanisms (Ca2+ and cAMP levels) in GLUTag and MIN6 cells as well as in their co-culture has been evaluated. Further, the effect of Kaempferol on GLP-1 and insulin release was evaluated under in-vivo circumstances in the DN C57BL/6 mouse model. Histology and fibrosis specific staining was performed to study the renal injuries and fibrosis, while the expression of mRNA and protein of interest was evaluated by RT-PCR and western blot analysis.

RESULTS

Kaempferol treatment promoted the GLP-1 and insulin release, which was accompanied by increased intracellular levels of cAMP and Ca2+ in GLUTag and MIN6 cells. In agreement with in vitro studies, Kaempferol also increased the release of GLP-1 and insulin in the DN mouse model. Notably, Kaempferol showed the potential to ameliorate the histological changes as well as renal fibrosis while decreasing the expression levels of DN markers including TGF-β1, CTGF, fibronectin, collagen IV, IL-1β, RhoA, ROCK2, and p-MYPT1 in DN kidney tissues. A rise in the expression of E-cadherin and nephrin was also noted in the same study.

CONCLUSION

This study establishes that Kaempferol ameliorates renal injury and fibrosis by enhancing the release of GLP-1, insulin, and inhibition of RhoA/Rho Kinase. This study recommends Kaempferol for further clinical trials to be developed as novel therapeutics for improving the renal function in DN patients.

"H" for Heterogeneity in the Algorithm for Type 2 Diabetes Management

PURPOSE OF REVIEW

Genetic, socioeconomic and clinical features vary considerably among individuals with type 2 diabetes (T2D) influencing disease development, progression and response to therapy. Although a patient-centred approach to pharmacologic therapy of T2D is widely recommended, patients are often treated similarly, irrespective of the differences that may affect therapeutic response. Addressing the heterogeneity of T2D is a major task of diabetes research to lower the high rate of treatment failure as well as to reduce the risk of long-term complications.

RECENT FINDINGS

A pathophysiology-based clustering system seems the most promising to help in the stratification of diabetes in terms of complication risk and response to treatment. This urges for clinical studies looking at novel biomarkers related to the different metabolic pathways of T2D and able to inform about the therapeutic cluster of each patient. Here, we review the main settings of diabetes heterogeneity, to what extent it has been already addressed and the current gaps in knowledge towards a personalized therapeutic approach that considers the distinctive features of each patient.

Exosomal miRNA-215-5p Derived from Adipose-Derived Stem Cells Attenuates Epithelial-Mesenchymal Transition of Podocytes by Inhibiting ZEB2

Background

Podocyte migration is actively involved in the process of podocyte loss and proteinuria production, which is closely associated with the development of diabetic nephropathy (DN). Exosomes from adipose-derived stem cells (ADSCs-Exos) effectively inhibit podocyte apoptosis in the treatment of DN. However, how ADSCs-Exos affect the migration of podocytes is obscure. This study is aimed at exploring the regulatory role of ADSCs-Exos on cell migration and the underlying mechanism.

Methods

ADSCs-Exo was authenticated by transmission electron microscopy (TEM), western blotting, and flow cytometry. Cell viability and migration ability of podocytes were measured by CCK8 and Transwell assays, respectively. Relative expressions of miRNAs and mRNAs were determined by qRT-PCR. The transmitting between PKH26-labeled exosome and podocytes was evaluated by IF assay. Dual luciferase reporter assay was employed to detect the relationship between miR-215-5p and ZEB2.

Results

The exposure to serum from DN patient (hDN-serum) significantly inhibited cell viability of podocytes, but ADSCs-Exo addition notably blunts cytotoxicity induced by the transient stimulus of hDN-serum. Besides, ADSCs-Exo administration powerfully impeded high glucose- (HG-) induced migration and injury of podocyte. With the podocyte dysfunction, several miRNAs presented a significant decline under the treatment of HG including miR-251-5p, miR-879-5p, miR-3066-5p, and miR-7a-5p, all of which were rescued by the addition of ADSCs-Exo. However, only miR-251-5p was a key determinant in the process of ADSCs-Exo-mediated protective role on podocyte damage. The miR-251-5p inhibitor counteracted the improvement from the ADSCs-Exo preparation on HG-induced proliferation inhibition and migration promotion. Additionally, miR-215-5p mimics alone remarkably reversed HG-induced EMT process of podocyte. Mechanistically, we confirmed that ADSCs-Exos mediated the shuttling of miR-215-5p to podocyte, thereby protecting against HG-induced metastasis, possibly through inhibiting the transcription of ZEB2.

Conclusion

ADSCs-Exo has the protective effect on HG-evoked EMT progression of podocytes thru a mechanism involving ZEB2. Potentially, the ADSCs-Exo preparation is a useful therapeutic strategy for improving podocyte dysfunction and DN symptoms clinically.

MiRNA Expression is Associated with Clinical Variables Related to Vascular Remodeling in the Kidney and the Brain in Type 2 Diabetes Mellitus Patients

Background: The association of vascular remodeling in the kidney and the brain with a particular microRNAs (miRNA) profile is not well studied.Methods: Seventy-six patients with Type 2 diabetes and 11 healthy subjects were assessed concerning urine albumin: creatinine ratio (UACR), biomarkers of podocyte injury and of proximal tubule (PT) dysfunction. MiRNA were quantified in blood and urine by a real-time PCR System. Cerebrovascular ultrasound measurements were performed in the carotid and middle cerebral arteries.Results: MiRNA21 and miRNA124 correlated positively with nephrin, podocalyxin, synaptopodin, urinary N-acetyl-D-glucosaminidase (NAG), urinary kidney-injury molecule-1 (KIM-1), UACR, and negatively with eGFR; miRNA125a, 126, 146a, 192 correlated negatively with nephrin, podocalyxin, synaptopodin, urinary NAG, urinary KIM-1, UACR, and directly with eGFR. Plasma miRNA-21 and miRNA192 correlated directly with cerebral hemodynamics parameters of atherosclerosis and arteriosclerosis. MiRNA-124, 125a, 126, 146a showed negative correlations with the same parameters.Conclusions: In Type 2 diabetes patients there is an association of vascular remodeling in the brain and the kidney with a specific miRNAs pattern. Cerebrovascular changes occur even in normoalbuminuric patients, with 'high-to-normal' levels of podocyte injury and PT dysfunction biomarkers. These phenomena may be explained by the variability of miRNA expression within the two organs in early DKD.

Crosstalk between miR-215 and epithelial-mesenchymal transition specific markers (E-cadherin and N-cadherin) in different stages of chronic HCV Infection

The main causes of death among patients with hepatocellular carcinoma (HCC) are a recurrence, metastasis, and deterioration of primary tumors by the epithelial-to-mesenchymal transition (EMT) which is controlled by several molecules including E-cadherin and N-cadherin. Microribonucleic acids (miRNAs) have been identified to play a regulatory role in EMT. miR-215 is important in repressing migration/invasion of cancer cells. In this study, we aimed to evaluate the crosstalk between miR-215 and EMT specific markers (E-cadherin and N-cadherin) with a spotlight on its role in the EMT process in hepatitis C virus (HCV)-infected patients. One hundred forty-five patients were studied, 75 had HCV-induced cirrhosis classified into child A, B, and C and 25 had HCC. In parallel, 45 healthy volunteers considered as controls. Serum levels of E- and N-cadherin were measured using enzyme-linked immunosorbent assay and miR-215 expression measured by a quantitative reverse transcription-polymerase chain reaction. Insignificant change in serum levels of E-cadherin and N-cadherin in HCV-infected patients compared with normal controls was observed with a slight increase in E-cadherin and N-cadherin in the child B group. HCC patients had the lowest amount of E-cadherin and N-cadherin compared with cirrhotic and normal subjects. A maximum reduction in miR-215 was observed in HCC patients compared with cirrhotic and control ones. A positive correlation (r = .202; P < .05) was observed between miR-215 and E-cadherin. Our data stressed on the potential role of miR-215 as an important mediator in HCC progression. miRNAs participating in EMT needs further studies to provide insight into the metastasis of HCC.

Xiaokeping Mixture Attenuates Diabetic Kidney Disease by Modulating TGF-β/Smad Pathway in db/db Mice

Xiaokeping mixture (XKP), a traditional Chinese medicine compound preparation, has achieved widespread use for diabetes mellitus and its kidney damage in clinical practice. The current study was carried out to assess the protective effect of XKP in spontaneous diabetic db/db mice and the underlying mechanism whereby XKP regulates TGF-β/Smad pathway. Male C57BLKS/J db/db mice, 12 weeks old, were randomly divided into 3 groups: the model group, 17.5 mg/kg irbesartan-treated group (IST group), and 8 g/kg XKP-treated group (XKP group), while age-matched db/m mice were selected as a control group. After 8 weeks of administration, serum and urea samples were collected from mice for biochemical tests, while the kidneys were removed for histological analysis. The expression of TGF-β/Smad pathway-related mRNA and protein were measured by RT-PCR and western blot analysis. Treatment with XKP significantly improved renal function and attenuated the pathological change of diabetic kidney disease (DKD) in renal histopathology. Furthermore, the overexpression of TGF-β1, Smad3, and p-Smad3 was inhibited, as well as the reduction of Smad7 and SIP1 was weakened by XKP. In conclusion, these results suggest that XKP could attenuate DKD by modulating TGF-β/Smad pathway.

Interleukins and miRNAs intervene in the early stages of diabetic kidney disease in Type 2 diabetes mellitus patients

Aim: The involvement of proinflammatory interleukins (IL) in diabetic kidney disease of Type 2 diabetes mellitus (DM) patients was studied in relation to a particular miRNA profile. Materials & methods: A total of 117 patients with Type 2 DM and 11 controls were enrolled in a case series study. Serum and urinary ILs and miRNAs were assessed. Results: IL-1α correlated with miRNA21, 124, estimated glomerular filtration rate (eGFR) and negatively with miRNA125a and 192; IL-8 with miRNA21, 124, eGFR and negatively with miRNA125a, 126 and 146a; IL-18 with miRNA21, 124 and negatively with miRNA146a, 192, eGFR. Conclusion: There is an association between specific serum and urinary ILs and serum and urinary miRNAs profiles in the inflammatory response in Type 2 DM patients with diabetic kidney disease.

Serum and tissue miRNAs: potential biomarkers for the diagnosis of cervical cancer

Background

Finding new biomarkers for the early detection of cervical cancer is an essential requirement in this field. In this study, we aimed to evaluate the expression level of potential biomarkers in progression of cervical cancer in patients with cervical cancer compared to normal subjects.

Methods

The expression levels of tissue and serum miRNAs, including miR-9, miR-192 and miR-205, were investigated in 36 normal, 18 precancer, and 18 cervical cancer samples using real-time polymerase chain reaction.

Results

The results showed the higher significant expressions of miR-9, miR-192 and miR-205 in the tissue of cancer samples than those in the normal samples. Moreover, the miR-192 and miR-205 expression were significantly increased in the cancer group in comparison with the precancer group. Examination of serum samples revealed the increase in the expression level in the cancer groups than in the normal samples, for miR-9, miR-192 and miR-205 and the expressions of miR-9, miR-192 and miR-205 were significantly up-regulated in the precancer group in comparison with the normal group. Also the expression of miR-205 was remarkably increased in the cancer group in comparison with the precancer group. The receiver operating characteristic (ROC) analyses showed the highest area under the curve value for miR-192.

Conclusions

Given the increased expression level of miR-192 in cancer and in precancerous tissue and serum compared with the normal tissue and serum validated by analysing the ROC curve, miR-192 can be used as potential biomarker for the early detection of cervical cancer.

Emerging role of miRNAs in renal fibrosis

As one type of the most common endogenous short noncoding RNAs (ncRNAs), microRNAs (miRNAs) act as posttranscriptional regulators of gene expression and have great potential biological functions in the physiological and pathological processes of various diseases. The role of miRNAs in renal fibrosis has also attracted great attention in the previous 20 years, and new therapeutic strategies targeting miRNAs appear to be promising. Some researchers have previously reviewed the roles of miRNA in renal fibrosis disease, but numerous studies have emerged over the recent 5 years. It is necessary to update and summarize research progress in miRNAs in renal fibrosis. Thus, in this review, we summarize progress in miRNA-mediated renal fibrosis over the last 5 years and evaluate the biological functions of some miRNAs in different stages of renal fibrosis. Furthermore, we also expound the recent clinical applications of these miRNAs to provide new insights into the treatment of renal fibrosis disease.

TGF-β/Smad and Renal Fibrosis

Renal fibrosis is characterized by excessive deposition of extracellular matrix (ECM) that disrupts and replaces functional parenchyma, which leads to organ failure. It is known as the major pathological mechanism of chronic kidney disease (CKD). Although CKD has an impact on no less than 10% of the world population, therapeutic options are still limited. Regardless of etiology, elevated TGF-β levels are highly correlated with the activated pro-fibrotic pathways and disease progression. TGF-β, the key driver of renal fibrosis, is involved in a dynamic pathophysiological process that leads to CKD and end-stage renal disease (ESRD). It is becoming clear that epigenetics regulates renal programming, and therefore, the development and progression of renal disease. Indeed, recent evidence shows TGF-β1/Smad signaling regulates renal fibrosis via epigenetic-correlated mechanisms. This review focuses on the function of TGF-β/Smads in renal fibrogenesis, and the role of epigenetics as a regulator of pro-fibrotic gene expression.

Chondrocyte sheet in vivo cartilage regeneration technique using miR-193b-3p to target MMP16

Stable cartilage regeneration has always been a challenge in both tissue engineering research and clinical practice. This study explored the feasibility of using a chondrocyte sheet technique stimulated by microRNAs to regenerate cartilage. We tested the involvement of hsa-miR-193b-3p in the microtia patient remnant auricular chondrocyte extracellular matrix (ECM). We observed in vitro chondrocyte proliferation, ECM synthesis, as well as the increase in the expression of type II collagen (COL2A1) and decrease in the expression of matrix metalloproteinase 16 (MMP16) of the chondrocyte sheets. COL2A1 deposition and MMP16 degradation of regenerative cartilage tissue were examined in vivo. A dual-luciferase reporter showed that the MMP16 gene was the direct target of miR-193b-3p. These results suggested that miR-193b-3p promotes chondrocyte sheet ECM synthesis by inhibiting MMP16. Since the evidence suggests that MMP16 is a critical regulator of chondrocyte ECM, this finding points the way towards a method that both strengthens the ECM and inhibits MMPs.

Expression of miRNAs-122, -192 and -499 in end stage renal disease associated with acute myocardial infarction

INTRODUCTION

New diagnostic tools are needed to accurately detect acute myocardial infarction (AMI) in patients with end stage renal disease (ESRD) presenting with ischemic chest pain. We aimed in this study to investigate circulating miR-122, -192 and -499 expression levels in patients with AMI on top of ESRD and evaluate the potential of these miRNAs as blood-based biomarkers for AMI in patients with ESRD.

MATERIAL AND METHODS

The study included 80 ESRD patients without AMI, 80 patients with ESRD associated with AMI and 60 healthy subjects. Assessment of microRNAs was done using SYBR Green based real-time PCR.

RESULTS

Levels of miR-122 were 28-fold and 20-fold higher in controls than in ESRD patients with or without AMI respectively (p < 0.001), while no differences were detected between the two patient groups (p = 0.9). Levels of miR-192 showed a marked increase in ESRD patients with and without AMI compared to the control group (> 500-fold, > 8000-fold respectively, p ≤ 0.001). Patients who developed AMI had lower expression than ESRD patients without AMI (p < 0.001). Non-significant miR-499 elevation was found in ESRD patients without cardiac disease compared to the control group, while highly significant elevation of miR- 499 was demonstrated in ESRD patients who developed AMI compared to other ESRD patients and the control group (> 100-fold, > 350-fold respectively, p = 0.001).

CONCLUSIONS

Altered expression of miR-122 and -192 may contribute in pathogenesis of ESRD. MiR-192 and -499 may serve as potential biomarkers for AMI in ESRD. Further studies are needed to correlate these miRNAs with disease progression and outcome.

Intrarenal microRNA signature related to the fibrosis process in chronic kidney disease: identification and functional validation of key miRNAs

BACKGROUND

Though the roles of microRNAs (miRNAs) in renal diseases have been extensively investigated, a thorough screening and comparison of miRNAs among different types of chronic kidney disease (CKD) has never been performed.

METHODS

The intrarenal miRNAs were profiled from fresh kidney tissues of patients with biopsy-proven minimal change disease (MCD), focal segmental glomerular sclerosis (FSGS) and diabetic nephropathy (DN) by using microarray. Commonly dysregulated miRNAs were validated by real-time PCR using paraffin-embedded renal tissues from all three types of CKD patients as well as mouse unilateral ureteral obstruction (UUO) model. Two novel miRNAs were selected and annotations of their target genes were performed using GO and KEGG pathway enrichment analysis. Biological functions of three two candidate miRNAs were explored in TGF-β1-induced cell model using human kidney proximal tubular cells (HK-2).

RESULTS

The kidney biopsy samples of three disease types represent different levels of damage and fibrosis, which were the mildest in MCD, moderate in FSGS, and the most severe in DN. 116 miRNAs were identified to be commonly dysregulated, including 40 up-regulated and 76 down-regulated in CKD tissues as compared with healthy donor kidney biopsy tissues. Two novel miRNAs, hsa-miR-3607-3p and hsa-miR-4709-3p, were verified as consistently differentially expressed among all three types of patient samples as well as in mouse model. In vitro, hsa-miR-3607-3p was repressed while hsa-miR-4709-3p was induced by TGF-β1 treatment. Inhibition of hsa-miR-3607-3p or overexpression of hsa-miR-4709-3p promoted TGF-β1-induced migration and F-actin assembling in HK-2 cells, which are characteristics of epithelial-mesenchymal transition (EMT). Further study identified that ITGB8 and CALM3 were the bona fide target genes of hsa-miR-3607-3p and hsa-miR-4709-3p respectively.

CONCLUSIONS

The present identify a unique miRNAs profile that probably relates to the common fibrosis process of CKD. Results of our study suggest that hsa-miR-3607-3p and hsa-miR-4709-3p may represent as promising therapeutic targets against kidney fibrosis.

Captopril and Spironolactone Can Attenuate Diabetic Nephropathy in Wistar Rats by Targeting microRNA-192 and microRNA-29a/b/c

Diabetes mellitus is a complicated metabolic disease characterized by hyperglycemia. Diabetic nephropathy (DN) is a progressive kidney disease, which results in mortality in diabetic patients. The present study was designed to investigate the effect of applying spironolactone (S), captopril (C), and their combination (S+C) on some renal performance indices and microRNAs' (miRNAs) expression. A total of 35 two-month-old male Wistar rats were provided for the study. Intraperitoneal injection of freshly dissolved streptozotocin (60 mg/kg) in cold citrate buffer was used to induce diabetes. Blood samples were examined through calorimetry to assess serum concentrations of glucose, blood urea nitrogen (BUN), and creatinine. To measure the microalbuminuria and transforming growth factor-β (TGF-β) levels and to evaluate the miRNAs expression levels of the kidney tissue, the ELISA method and the real-time PCR were used. The obtained results serve as in vivo evidence for the positive relationship between miR-192 and TGF-β levels in the DN rats. A significant increase and decrease were found for miR-29a/b/c and the miR-192 expression of DN after treatment with S, C, and S+C. TGF-β levels and microalbuminuria of diabetic rats also increased. The results obtained from this research study suggest that S, C, and S + C can improve DN by targeting miR-192 and miR-29 family and changing their expression. These findings suggest that miR-192 and miRs-29a/b/c can be potential targets for DN remediation.

microRNA Crosstalk Influences Epithelial-to-Mesenchymal, Endothelial-to-Mesenchymal, and Macrophage-to-Mesenchymal Transitions in the Kidney

microRNAs (miRNAs) are small, non-coding nucleotides that regulate diverse biological processes. Altered microRNA biosynthesis or regulation contributes to pathological processes including kidney fibrosis. Kidney fibrosis is characterized by deposition of excess extracellular matrix (ECM), which is caused by infiltration of immune cells, inflammatory cells, altered chemokines, and cytokines as well as activation and accumulation of fibroblasts in the kidney. These activated fibroblasts can arise from epithelial cells via epithelial-to-mesenchymal transition (EMT), from bone marrow-derived M2 phenotype macrophages via macrophage-to-mesenchymal transition (MMT), from endothelial cells via endothelial-to-mesenchymal transition (EndMT), from resident fibroblasts, and from bone marrow-derived monocytes and play a crucial role in fibrotic events. Disrupted microRNA biosynthesis and aberrant regulation contribute to the activation of mesenchymal programs in the kidney. miR-29 regulates the interaction between dipeptidyl peptidase-4 (DPP-4) and integrin β1 and the associated active transforming growth factor β (TGFβ) and pro-EndMT signaling; however, miR-let-7 targets transforming growth factor β receptors (TGFβRs) to inhibit TGFβ signaling. N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) is an endogenous anti-fibrotic peptide, which is associated with fibroblast growth factor receptor 1 (FGFR1) phosphorylation and subsequently responsible for the production of miR-let-7. miR-29 and miR-let-7 family clusters participate in crosstalk mechanisms, which are crucial for endothelial cell homeostasis. The physiological level of AcSDKP is vital for the activation of anti-fibrotic mechanisms including restoration of anti-fibrotic microRNA crosstalk and suppression of profibrotic signaling by mitigating DPP-4-associated mesenchymal activation in the epithelial cells, endothelial cells, and M2 phenotype macrophages. The present review highlights recent advancements in the understanding of both the role of microRNAs in the development of kidney disease and their potential as novel therapeutic targets for fibrotic disease states.

Astragaloside IV inhibits excessive mesangial cell proliferation and renal fibrosis caused by diabetic nephropathy via modulation of the TGF-β1/Smad/miR-192 signaling pathway

Astragaloside IV (ASI) exhibits a wide variety of pharmacological effects in cardiovascular diseases, hepatitis and kidney disease and due to this, ASI has recently become an attractive research target. The present study aimed to determine the effect of ASI on renal fibrosis and the mechanisms underlying its therapeutic effects in diabetic nephropathy (DN). In vitro, ASI was added to rat mesangial cells (RMCs) and cultured with a high level of glucose (HG) to observe the effects exhibited on proliferation and fibrosis-related mRNA and protein expression. In vivo, a DN model was established using streptozotocin administration in rats, and renal injury was evaluated using renal histological examination. The expression levels of related mRNAs and proteins were analyzed using reverse transcription-quantitative PCR, western blot analysis and immunohistochemistry. ASI was demonstrated to downregulate miR-192 expression and inhibit excessive proliferation of RMCs, which was induced by HG, in a dose-dependent manner. Additionally, ASI exhibited a therapeutic effect on DN rats. ASI was also demonstrated to decrease the miR-192 expression and mRNA and protein expression of transforming growth factor-β1 (TGF-β1), Smad3, α-smooth muscle actin (α-SMA) and collagen type 1 (col1), and increase the mRNA and protein expression of Smad7 in vitro and in vivo. These results suggested that ASI exhibited a therapeutic effect on DN, possibly due to the inhibition of excessive mesangial proliferation and renal fibrosis via the TGF-β1/Smad/miR-192 signaling pathway.

miR-200c Prevents TGF-β1-Induced Epithelial-to-Mesenchymal Transition and Fibrogenesis in Mesothelial Cells by Targeting ZEB2 and Notch1

Peritoneal fibrosis and loss of transport function is a common complication contributing to adverse outcomes in patients on long-term peritoneal dialysis (PD). Epithelial-to-mesenchymal transition (EMT) in mesothelial cells is a salient feature, but its triggering mechanisms remain obscure. Dysregulation of microRNA (miR) expression is implicated in EMT and tissue fibrosis. We investigated the role of miR-200c in EMT and fibrogenesis in a murine PD model and in cultured peritoneal mesothelial cells. PD-fluid-treated mice showed peritoneal miR-200c expression reduced by 76.2% compared with PBS-treated mice, and this was accompanied by increased peritoneal α-smooth muscle actin, fibronectin, and collagen expression. PD fluid and TGF-β1 both reduced miR-200c expression in cultured mesothelial cells, accompanied by downregulation of E-cadherin and decorin, and induction of fibronectin, collagen I and III, and transcription factors related to EMT. Decorin prevented the suppression of miR-200c by TGF-β1. Lentivirus-mediated miR-200c overexpression prevented the induction of fibronectin, collagen I, and collagen III by TGF-β1, independent of decorin, and partially prevented E-cadherin suppression by TGF-β1. Target genes of miR-200c were identified as ZEB2 and Notch1. Our data demonstrate that miR-200c regulates EMT and fibrogenesis in mesothelial cells, and loss of peritoneal miR-200c contributes to PD-associated peritoneal fibrosis.

Non-Coding RNAs as New Therapeutic Targets in the Context of Renal Fibrosis

Fibrosis, or tissue scarring, is defined as the excessive, persistent and destructive accumulation of extracellular matrix components in response to chronic tissue injury. Renal fibrosis represents the final stage of most chronic kidney diseases and contributes to the progressive and irreversible decline in kidney function. Limited therapeutic options are available and the molecular mechanisms governing the renal fibrosis process are complex and remain poorly understood. Recently, the role of non-coding RNAs, and in particular microRNAs (miRNAs), has been described in kidney fibrosis. Seminal studies have highlighted their potential importance as new therapeutic targets and innovative diagnostic and/or prognostic biomarkers. This review will summarize recent scientific advances and will discuss potential clinical applications as well as future research directions.

Increased Extracellular Matrix Protein Production in Chronic Diabetic Complications: Implications of Non-Coding RNAs

Management of chronic diabetic complications remains a major medical challenge worldwide. One of the characteristic features of all chronic diabetic complications is augmented production of extracellular matrix (ECM) proteins. Such ECM proteins are deposited in all tissues affected by chronic complications, ultimately causing organ damage and dysfunction. A contributing factor to this pathogenetic process is glucose-induced endothelial damage, which involves phenotypic transformation of endothelial cells (ECs). This phenotypic transition of ECs, from a quiescent state to an activated dysfunctional state, can be mediated through alterations in the synthesis of cellular proteins. In this review, we discussed the roles of non-coding RNAs, specifically microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), in such processes. We further outlined other epigenetic mechanisms regulating the biogenesis and/or function of non-coding RNAs. Overall, we believe that better understanding of such molecular processes may lead to the development of novel biomarkers and therapeutic strategies in the future.

A Glimpse of the Mechanisms Related to Renal Fibrosis in Diabetic Nephropathy

Diabetic nephropathy (DN) is a common kidney disease in people with diabetes, which is also a serious microvascular complication of diabetes and the main cause of end-stage renal disease (ESRD) in developed and developing countries. Renal fibrosis is a finally pathological change in DN. Nevertheless, the relevant mechanism of cause to renal fibrosis in DN is still complex. In this review, we summarized that the role of cell growth factors, epithelial-mesenchymal transition (EMT) in the renal fibrosis of DN, we also highlighted the miRNA and inflammatory cells, such as macrophage, T lymphocyte, and mastocyte modulate the progression of DN. In addition, there are certain other mechanisms that may yet be conclusively defined. Recent studies demonstrated that some of the new signaling pathways or molecules, such as Notch, Wnt, mTOR, Epac-Rap-1 pathway, may play a pivotal role in the modulation of ECM accumulation and renal fibrosis in DN. This review aims to elucidate the mechanism of renal fibrosis in DN and has provided new insights into possible therapeutic interventions to inhibit renal fibrosis and delay the development of DN.

Bariatric Surgery Modulates Urinary Levels of MicroRNAs Involved in the Regulation of Renal Function

Background: Obesity and diabetes cause chronic kidney disease with a common pathophysiology that is characterized by the accumulation of collagen in the extracellular matrix. Recent evidence has implicated the epithelial-to-mesenchymal transition (EMT) as a key step in this pathology with regulation by microRNAs. Weight loss leads to improvements in renal function; therefore, this study hypothesized that bariatric-surgery aided weight loss would lead to changes in urinary microRNAs involved in the regulation of renal function. Materials and methods: Twenty-four bariatric patients undergoing Roux-en-Y gastric bypass and sleeve gastrectomy donated urine pre-operatively and at 2-6 months and 1-2 years post-operatively. Urine samples were also obtained from 10 healthy weight and 7 morbidly obese non-surgical controls. Expression levels of kidney microRNAs were assessed in urine and the function of microRNAs was assessed through the in vitro transfection of HK-2 cells, a kidney proximal tubule cell line. Results: Levels of miR 192, miR 200a, and miR 200b were upregulated in urine following bariatric surgery. This increase was consistent across surgical type and diabetes status and was maintained and enhanced with time. Bariatric surgery alters urinary miR 192 expression from levels seen in morbidly obese patients to levels seen in healthy weight control patients. In mechanistic studies, the transfection of miR 192 in HK-2 cells increased miR 200a expression and decreased ZEB2, a key transcriptional promoter of kidney fibrosis. Conclusions: Bariatric surgery increased miR 192 and miR 200 urinary levels, key anti-fibrotic microRNAs that could contribute to a renal-protective mechanism and may be of value as urinary biomarkers following surgery. These findings suggest that urinary microRNAs may represent potential novel biomarkers for obesity-associated renal function.

The Role of MicroRNAs in the Pathogenesis of Diabetic Nephropathy

Diabetic nephropathy (DN) is one of the most common microvascular complications in diabetic patients; it is also an important cause of renal dysfunction, renal fibrosis, and end-stage renal disease. Unfortunately, the pathogenesis of DN is complex and has not yet been fully elucidated; hence, the pathogenesis of DN to determine effective treatments of crucial importance is deeply explored. Early DN research focuses on hemodynamic changes and metabolic disorders, and recent studies have shown the regulatory role of microRNAs (miRNAs) in genes, which may be a new diagnostic marker and therapeutic target for diabetic nephropathy. In this review, we summarize the recent advances in the clinical value and molecular mechanisms of miRNAs in DN, providing new ideas for the diagnosis and treatment of DN.

MicroRNAs and diabetic kidney disease: Systematic review and bioinformatic analysis

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. Emerging evidence has suggested a role for miRNAs in the development of diabetic kidney disease (DKD), indicating that miRNAs may represent potential biomarkers of this disease. However, results are still inconclusive. Therefore, we performed a systematic review of the literature on the subject, followed by bioinformatic analysis. PubMed and EMBASE were searched to identify all studies that compared miRNA expressions between patients with DKD and diabetic patients without this complication or healthy subjects. MiRNA expressions were analyzed in kidney biopsies, urine/urinary exosomes or total blood/plasma/serum. MiRNAs consistently dysregulated in DKD patients were submitted to bioinformatic analysis to retrieve their putative target genes and identify potentially affected pathways under their regulation. As result, twenty-seven studies were included in the systematic review. Among 151 dysregulated miRNAs reported in these studies, 6 miRNAs were consistently dysregulated in DKD patients compared to controls: miR-21-5p, miR-29a-3p, miR-126-3p, miR-192-5p, miR-214-3p, and miR-342-3p. Bioinformatic analysis indicated that these 6 miRNAs are involved in pathways related to DKD pathogenesis, such as apoptosis, fibrosis, and extracellular matrix accumulation. In conclusion, six miRNAs seem to be dysregulated in patients with different stages of DKD, constituting potential biomarkers of this disease.