miR-181c protects CsA-induced renal damage and fibrosis through inhibiting EMT

Divergent cardiac and renal effects of miR-181c-5p inhibition in a rodent heart failure model

Aims

MiR-181c-5p overexpression associates with heart failure (HF) and cardiac damage, but the underlying pathophysiology remains unclear. This study investigated the effect of miR-181c-5p inhibition on cardiac function and fibrosis in a rodent model of diastolic dysfunction, and evaluated additional effects on kidney as relevant comorbid organ.

Methods and results

Diastolic dysfunction was induced in male C57/BL6J mice (n = 20) by combining high-fat diet, L-NG-nitroarginine methyl ester, and angiotensin II administration, and was compared to sham controls (n = 18). Mice were randomized to subcutaneous miR-181c-5p antagomiR (INH) or scrambled antagomiR injections (40 mg/kg/week). HF mice demonstrated diastolic dysfunction and increased fibrosis, which was attenuated by INH treatment. Remarkably, HF + INH animals had a threefold higher mortality rate (60%) compared to HF controls (20%). Histological examination revealed increased glomerular damage in all INH treated mice, and signs of thrombotic microangiopathy (TMA) in mice who died prematurely. Quantitative polymerase chain reaction demonstrated a miR-181c-5p-related downregulation of cardiac but not renal Tgfbr1 in HF + INH mice, while INH treatment reduced renal but not cardiac Vegfa expression in all mice.

Conclusion

This study demonstrates cardiac anti-fibrotic effects of miR-181c-5p inhibition in a rodent HF model through targeting of Tgfbr1 in the heart. Despite improved diastolic function, HF + INH mice had higher mortality due to increased predisposition for TMA, increased renal fibrosis and glomerular damage, associated with Vegfa downregulation in kidneys.

Human kidney organoids model of Esculentoside A nephrotoxicity to investigate the role of epithelial-mesenchymal transition via STING signaling

Radix Phytolaccae (RP) has a long medicinal history and is commonly used to treat systemic edema and ascites in Asia. Although RP is known to cause nephrotoxicity, the role of its main constituent, Esculentoside A (EsA), in nephrotoxicity remains undetermined. We used kidney organoids derived from human inducible pluripotent stem cells (iPSCs) to model EsA nephrotoxicity accurately. Kidney organoids were differentiated and treated with EsA at doses of 0, 15, 30, or 60 μM for 48 h. The in vitro model was compared to a mouse model of EsA nephrotoxicity (intraperitoneally injected, 25 mg·kg^-1). The mechanisms were investigated. Cell viability decreased dose-dependently after treatment with EsA. As polarity was lost, tubular cells decreased, similar to mouse EsA nephrotoxicity with upregulated vimentin expression and a stimulator of the interferon gene (STING). Furthermore, 60 μM EsA could induce endothelial inflammation, lead to mitochondrial damage and activate STING by translocating mtDNA into the cytoplasm to develop an inflammatory cascade and destroy renal endothelial cells with interstitial changes. The data suggest that kidney organoids derived from iPSCs are promising for investigating nephrotoxicity. EsA nephrotoxicity involves the epithelial-mesenchymal transition via STING signaling.

LncRNA-ATB regulates epithelial-mesenchymal transition progression in pulmonary fibrosis via sponging miR-29b-2-5p and miR-34c-3p

Dysregulation of non‐coding RNAs (ncRNAs) has been proved to play pivotal roles in epithelial‐mesenchymal transition (EMT) and fibrosis. We have previously demonstrated the crucial function of long non‐coding RNA (lncRNA) ATB in silica‐induced pulmonary fibrosis‐related EMT progression. However, the underlying molecular mechanism has not been fully elucidated. Here, we verified miR‐29b‐2‐5p and miR‐34c‐3p as two vital downstream targets of lncRNA‐ATB. As opposed to lncRNA‐ATB, a significant reduction of both miR‐29b‐2‐5p and miR‐34c‐3p was observed in lung epithelial cells treated with TGF‐β1 and a murine silicosis model. Overexpression miR‐29b‐2‐5p or miR‐34c‐3p inhibited EMT process and abrogated the pro‐fibrotic effects of lncRNA‐ATB in vitro. Further, the ectopic expression of miR‐29b‐2‐5p and miR‐34c‐3p with chemotherapy attenuated silica‐induced pulmonary fibrosis in vivo. Mechanistically, TGF‐β1‐induced lncRNA‐ATB accelerated EMT as a sponge of miR‐29b‐2‐5p and miR‐34c‐3p and shared miRNA response elements with MEKK2 and NOTCH2, thus relieving these two molecules from miRNA‐mediated translational repression. Interestingly, the co‐transfection of miR‐29b‐2‐5p and miR‐34c‐3p showed a synergistic suppression effect on EMT in vitro. Furthermore, the co‐expression of these two miRNAs by using adeno‐associated virus (AAV) better alleviated silica‐induced fibrogenesis than single miRNA. Approaches aiming at lncRNA‐ATB and its downstream effectors may represent new effective therapeutic strategies in pulmonary fibrosis.

Astragalus membranaceus and Salvia miltiorrhiza ameliorates cyclosporin A-induced chronic nephrotoxicity through the "gut-kidney axis"

ETHNOPHARMACOLOGICAL RELEVANCE

The combination of Astragalus membranaceus and Salvia miltiorrhiza (AS) is an effective prescription that is widely used to treat chronic kidney disease (CKD) clinically in traditional Chinese medicine. Our previous studies have shown that AS can alleviate early CKD through the "gut-kidney axis", but the regulatory role of AS in the "gut-kidney axis" in the middle and late stages of CKD caused by cyclosporin A-induced chronic nephrotoxicity (CICN) has remained unclear.

AIM OF THE STUDY

To explore the protective effect of AS by regulating the intestinal flora to further control the miRNA-mRNA interaction profiles in CICN.

MATERIALS AND METHODS

Thirty-two mice were divided into four groups: Normal (N) (olive oil), Model (M) (CsA, 30 mg kg-1 d-1), AS (CsA + AS, 30 + 8.4 g kg-1 d-1) and FMT-AS (CsA + Faeces of AS group, 30 mg + 10 mL kg-1 d-1). The mice were treated for 6 weeks. Changes in renal function related metabolites were detected, pathological changes in the colon and kidney were observed, and 16S rDNA sequencing was performed on mouse faeces. In addition, miRNA and mRNA sequencing were performed on the kidney to construct differential expression (DE) profiles of the other 3 groups compared with group M. The target mRNAs among the DE miRNAs were then predicted, and an integrated analysis was performed with the DE mRNAs to annotate gene function by KEGG. DE miRNAs and DE mRNAs related to CICN in the overlapping top 20 KEGG pathways were screened and verified.

RESULTS

Eight metabolites that could worsen renal function were increased in group M, accompanied by thickening of the glomerular basement membrane, vacuolar degeneration of renal tubules, and proliferation of collagen fibres, while AS and FMT-AS intervention amended these changes to varying degrees. Simultaneously, intestinal permeability increased, the abundance and diversity of the flora decreased, and the ratio of Firmicum to Bacteroides (F/B) increased in group M. The AS and FMT-AS treatments reversed the flora disorder and increased probiotics producing butyric acid and lactic acid, especially Akkermansia and Lactobacillus, which might regulate the 12 overlapping top 20 KEGG pathways, such as Butanoate metabolism, Tryptophan metabolism and several RF-related pathways, leading to the remission of renal metabolism. Finally, 15 DE miRNAs and 45 DE mRNAs were screened as the therapeutic targets, and the results coincided with the sequencing results.

CONCLUSION

AS could alleviate renal fibrosis and metabolism caused by CICN through the "gut-kidney axis". Probiotics such as Akkermansia and Lactobacillus were the primary driving factors, and the miRNA-mRNA interaction profiles, especially Butanoate metabolism and Tryptophan metabolism, may be an important subsequent response and regulatory mechanism.

Identifying Key MicroRNAs Targeted by Narenmandula in a Rodent Nephropathy Model

Background

Untreated nephropathy can progress to renal failure. The traditional Mongolian remedy Narenmandula regulates the kidney “yang.” This study aimed to identify key microRNAs (miRNAs) targeted by Narenmandula in a rat model of nephropathy.

Methods

Fifteen rats exhibiting normal renal function were randomized to three study arms. Nephropathy was induced in n = 10 rats using doxorubicin hydrochloride, followed by either Narenmandula treatment (treatment group) or no treatment (control group). In n = 5 rats, no doxorubicin was given and renal function remained unchanged (healthy group). Microarray analysis identified miRNAs which were differentially expressed (DE-miRNAs) between groups. Target genes of DE-miRNAs were predicted using miRWalk version 2.0, followed by enrichment analysis using DAVID, and construction of the miRNA coregulatory network using Cytoscape.

Results

Nephropathy was successfully induced, with doxorubicin resulting in differential expression of 3645 miRNAs (1324 upregulated and 2321 downregulated). Narenmandula treatment induced differential expression of a total of 159 miRNAs (102 upregulated and 57 downregulated). Upregulated DE-miRNAs (e.g., miR-497-5p, miR-195-5p, miR-181a-5p, miR-181c-5p, and miR-30e-5p) and downregulated DE-miRNAs (e.g., miR-330-3p and miR-214-3p) regulated a high number of target genes. Moreover, the miRNA pairs (e.g., miR-195-5p—miR-497-5p, miR-181a-5p—miR-181c-5p, and miR-30e-5p—miR-30a-5p) coregulated a high number of genes. Enrichment analysis indicated functional synergy between miR-30e-5p—miR-30a-3p, miR-34a-5p—miR-30e-5p, miR-30e-5p—miR-195-3p, and miR-30a-3p—miR-195-3p pairs.

Conclusion

Narenmandula may modulate doxorubicin-induced nephropathy via targeting miR-497-5p, miR-195-5p, miR-181a-5p, miR-181c-5p, miR-30e-5p, miR-330-3p, miR-214-3p, miR-34a-5p, miR-30a-3p, and miR-30a-5p.

MicroRNA-140-5p Mediates Renal Fibrosis Through TGF-β1/Smad Signaling Pathway by Directly Targeting TGFBR1

Renal tubulointerstitial fibrosis is usually the final outcome of various end-stage renal diseases. Recent studies have reported that microRNAs (miRNAs) play an important role in renal fibrosis. However, the biological function of microRNAs in renal fibrosis is complicated and remains unclear. In this study, our results show that miR-140-5p expression is significantly down-regulated in mice with unilateral ureteral obstruction and human proximal tubule epithelial cells (HK2) treated with TGF-β1. The knockdown of miR-140-5p upregulates the expression levels of collagen I, collagen IV, and α-SMA, decreases E-cadherin expression, and increases Smad-2/3 phosphorylation. In contrast, the overexpression of miR-140-5p decreases the expression levels of collagen I, collagen IV, and α-SMA, enhances E-cadherin expression, and inhibits the phosphorylation of Smad-2/3 in HK2 cells treated with TGF-β1. The dual-luciferase reporter assay revealed that TGFBR1 is a direct target gene of miR-140-5p. The enforced expression of miR-140-5p significantly inhibited the expression of TGFBR1 in HK2 cells. Furthermore, the knockdown of TGFBR1 has a similar effect of miR-140-5p overexpression on blocking the TGF-β1/smad signal pathway activation. In contrast, the overexpression of TGFBR1 reverses the effect of miR-140-5p inhibition on the activation of the TGF-β1/smad signal pathway. This study demonstrates that miR-140-5p regulates the TGF-β1/smad signaling pathway by suppressing the expression of TGFBR1. Therefore, miR-140-5p may have a therapeutic potential for preventing fibrotic kidney diseases through inhibiting the TGF-β1/Smad signaling pathway by directly targeting TGFBR1.

miR-181b-5p inhibits endothelial-mesenchymal transition in monocrotaline-induced pulmonary arterial hypertension by targeting endocan and TGFBR1

Endothelial-mesenchymal transition (EndMT) is a frequent event in endothelial dysfunction, which is associated with pulmonary arterial hypertension (PAH). MiR-181 family members exert diverse effects in multiple biological processes. However, the relationships between miR-181b-5p (miR-181b) and EndMT in PAH are not well understood. In this study, Sprague-Dawley (SD) rats were injected with monocrotaline (MCT) to establish PAH model, and primary rat pulmonary arterial endothelial cells (rPAECs) were treated with TNF-α, TGFβ1 and IL-1β in combination to induce EndMT (I-EndMT). Then we explored miR-181b expression and examined its functional role in PAH. Our data showed that miR-181b was down-expressed in PAH, and its overexpression attenuated the hemodynamics, pulmonary vascular hypertrophy, right ventricular remodeling and EndMT process in MCT-induced PAH rats. In I-EndMT rPAECs, we observed that inducing miR-181b reversed the decrease of endothelial markers and increase of mesenchymal markers. However, knockdown of miR-181b induced similar effects to EndMT. In addition, endocan and TGFBR1 levels were also increased in EndMT, which were negatively regulated by miR-181b. Luciferase activity results indicated that endocan and TGFBR1 were direct target genes of miR-181b. In summary, our findings firstly demonstrate that the beneficial effect of miR-181b on PAH may be associated with endocan/TGFBR1-mediated EndMT, providing a new insight into the diagnosis and treatment of PAH.

The therapeutic effects of microRNAs in preclinical studies of acute kidney injury: a systematic review protocol

BACKGROUND

Acute kidney injury (AKI) causes significant morbidity and mortality in humans, and there are currently no effective treatments to enhance renal recovery. MicroRNAs (miRNAs) are short chain nucleotides that regulate protein expression and have been implicated in the pathogenesis of AKI. Recently, preclinical studies in vivo have uncovered a therapeutic role for administration of specific miRNAs in AKI. However, the overall benefits of this strategy in preclinical studies have not been systematically reviewed, and the potential for translation to human studies is unclear.

AIM

The primary aim is to conduct a systematic review of the therapeutic properties of miRNAs in preclinical studies of AKI. The secondary aim is to determine potential adverse effects of miRNA administration in these studies.

METHODS

A comprehensive search strategy will identify relevant studies in AKI in vivo models, using the MEDLINE, EMBASE, OVID, PUBMED, and Web of Science databases. The search strategy will include terms for mammalian (non-human) AKI models, including injury related to ischemia/reperfusion, nephrotoxicity, sepsis, contrast agents, cardio-pulmonary bypass, and hemorrhagic shock. Interventions will be defined as direct administration of exogenous miRNAs or antagonists of miRNAs, as well as maneuvers that alter expression of miRNAs that are mechanistically linked to AKI outcomes. The primary outcomes will be indices of kidney function and structure, and there will be no restriction on comparator interventions. Two independent investigators will initially screen abstracts, and selected articles that meet eligibility criteria will be reviewed for data abstraction and analysis. The SYRCLE RoB tool for animal studies will determine risk of bias, and meta-analysis will be performed as appropriate. The GRADE methodology will assess the quality of evidence.

DISCUSSION

The administration of selective miRNA mimics or antagonists exerts beneficial effects in mammalian models of AKI, although multiple obstacles must be addressed prior to translation to human clinical trials. The proposed systematic review will document key miRNA candidates, and determine effect size estimates and sources of outcome bias. The review will also identify gaps in knowledge and guide future directions in AKI research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019128854.

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.

miR-181c-5p mediates simulated microgravity-induced impaired osteoblast proliferation by promoting cell cycle arrested in the G2 phase

Impaired osteoblast proliferation plays fundamental roles in microgravity‐induced bone loss, and cell cycle imbalance may result in abnormal osteoblast proliferation. However, whether microgravity exerts an influence on the cell cycle in osteoblasts or what mechanisms may underlie such an effect remains to be fully elucidated. Herein, we confirmed that simulated microgravity inhibits osteoblast proliferation. Then, we investigated the effect of mechanical unloading on the osteoblast cell cycle and found that simulated microgravity arrested the osteoblast cell cycle in the G₂ phase. In addition, our data showed that cell cycle arrest in osteoblasts from simulated microgravity was mainly because of decreased cyclin B1 expression. Furthermore, miR‐181c‐5p directly inhibited cyclin B1 protein translation by binding to a target site in the 3′UTR. Lastly, we demonstrated that inhibition of miR‐181c‐5p partially counteracted cell cycle arrest and decreased the osteoblast proliferation induced by simulated microgravity. In conclusion, our study demonstrates that simulated microgravity inhibits cell proliferation and induces cell cycle arrest in the G₂ phase in primary mouse osteoblasts partially through the miR‐181c‐5p/cyclin B1 pathway. This work may provide a novel mechanism of microgravity‐induced detrimental effects on osteoblasts and offer a new avenue to further investigate bone loss induced by mechanical unloading.

Tumor-suppressive effects of microRNA-181d-5p on non-small-cell lung cancer through the CDKN3-mediated Akt signaling pathway in vivo and in vitro

The involvement of several microRNAs (miRs) in the initiation and development of tumors through the suppression of the target gene expression has been highlighted. The aberrant expression of miR-181d-5p and cyclin-dependent kinase inhibitor 3 (CDKN3) in non-small-cell lung cancer (NSCLC) was then screened by microarray analysis. In the present study, we performed a series of in vivo and in vitro experiments for the purpose of investigating their roles in NSCLC and the underlying mechanism. There was a high expression of CDKN3, whereas miR-181d-5p was downregulated in NSCLC. Quantitative RT-PCR, Western blot analysis, and dual-luciferase reporter gene assay further identified that CDKN3 could be negatively regulated by miR-181d-5p. Moreover, the upregulation of miR-181d-5p or silencing of CDKN3 could inactivate the Akt signaling pathway. A549 with the lowest miR-181d-5p and H1975 with the highest CDKN3 among the five NSCLC cell lines (H1299, A549, H1975, NCI-H157, and GLC-82) were adopted for in vitro experiments, in which expression of miR-181d-5p and CDKN3 was altered by transfection of miR-181d-5p mimic/inhibitor or siRNA-targeting CDKN3. Afterwards, cell proliferation, apoptosis, invasion, migration, and angiogenesis, as well as epithelial-mesenchymal transition (EMT), were evaluated, and tumorigenicity was assessed. In addition, an elevation in miR-181d-5p or depletion in CDKN3 led to significant reductions in proliferation, invasion, migration, angiogenesis, EMT, and tumorigenicity of NSCLC cells, coupling with increased cell apoptosis. In conclusion, this study highlights the tumor-suppressive effects of miR-181d-5p on NSCLC via Akt signaling pathway inactivation by suppressing CDKN3, thus providing a promising therapeutic strategy for the treatment of NSCLC.

Over-expressed microRNA-181a reduces glomerular sclerosis and renal tubular epithelial injury in rats with chronic kidney disease via down-regulation of the TLR/NF-κB pathway by binding to CRY1

BACKGROUND

MicroRNAs (miRNAs) contribute to the progression of chronic kidney disease (CKD) by regulating renal homeostasis. This study explored the effects of miR-181a on CKD through the Toll-like receptor (TLR)/nuclear factor-kappa B (NF-κB) pathway by binding to CRY1.

METHODS

Seventy male rats were selected and assigned into specific groups: miR-181a mimic, miR-181a inhibitor, and siRNA against CRY1, with each group undergoing different treatments to investigate many different outcomes. First, 24-h urinary protein was measured. ELISA was used to determine the serum levels of SOD, ROS, MDA, IL-1β, IL-6, and TNF-α. Biochemical tests for renal function were performed to measure albumin, uric acid, and urea in urine and urea nitrogen and creatinine in serum. The glomerulosclerosis index (GSI) and renal tubular epithelial (RTE) cell apoptosis were detected using PASM staining and TUNEL staining, respectively. Finally, RT-qPCR and western blot were done to determine miR-181a, CRY1, TLR2, TLR4, and NF-κB expression.

RESULTS

CRY1 is the target gene of miR-181a, according to a target prediction program and luciferase assay. Rats diagnosed with CKD presented increases in 24-h urinary protein; GSI; RTE cell apoptosis rate; serum ROS, MDA, IL-1β, IL-6, and TNF-α; and CRY1, TLR2, TLR4, and NF-κB expression, as well as decreases in SOD level and miR-181a expression. Following transfection with either the miR-181a mimic or si-CRY1, 24-h urinary protein, renal damage, GSI, and cell apoptosis rate were all decreased. In addition, the overexpression of miR-181a or inhibition of CRY1 alleviated the degree of kidney injury through suppression of the TLR/NF-κB pathway.

CONCLUSION

miR-181a alleviates both GS and RTE injury in CKD via the down-regulation of the CRY1 gene and the TLR/NF-κB pathway.

Inhibition of miR-135b by SP-1 promotes hypoxia-induced vascular endothelial cell injury via HIF-1α

Myocardial hypoxia-induced endothelial cell apoptosis contributes to cardiac dysfunction, such as myocardial infarction (MI), myocardial ischemia, and heart failure. Thus, it is important to investigate the molecular mechanisms of vascular endothelial cells (VECs) during exposure to hypoxia. SP-1 is an important regulator of cytokines associated with cell functions. We found that SP-1 expression increased in human umbilical vein endothelial cells (HUVECs) exposed to hypoxia by western blot. Then the SP-1 siRNA was transfected into HUVECs under hypoxic condition. MTT assay showed that hypoxia reduced the cell proliferation, but SP-1 siRNA reversed that. Transfection with si-SP-1 also reversed cell apoptosis and reactive oxygen species (ROS) production increased by hypoxia treatment. Moreover, inflammatory phenotype were increased in hypoxia induced HUVECs, including ICAM-1,VCAM-1 levels as well as TNFα, IL-6 and IL-1β secretion, and the si-SP-1 also reversed this effect of hypoxia. Additionally, si-SP-1 increased expression of miR-135b and reduced expression of hypoxia-inducible factor 1-α (HIF-1α), which is the target gene of miR-135b. To investigate the underlying mechanism of SP-1 on hypoxia induced HUVECs injury, the anti-miR-135b or HIF-1α agonist (CoCl2) were used. Finally, the result indicated that both anti-miR-135b or CoCl2 treatment reversed the effects of SP-1 siRNA under hypoxia. In conclusion, the SP-1/miR-135b/HIF-1α axis may play a critical role in hypoxia-induced vascular endothelial injury. Our study thus provides novel insights into the role of this transcription factor and miRNAs in the pathogenesis of hypoxia-induced cardiac dysfunctions.