miR-124/MCP-1 signaling pathway modulates the protective effect of itraconazole on acute kidney injury in a mouse model of disseminated candidiasis

Polyphenols target miRNAs as a therapeutic strategy for diabetic complications

MiRNAs are a large group of non-coding RNAs which participate in different cellular pathways like inflammation and oxidation through transcriptional, post-transcriptional, and epigenetic regulation. In the post-transcriptional regulation, miRNA interacts with the 3'-UTR of mRNAs and prevents their translation. This prevention or dysregulation can be a cause of pathological conditions like diabetic complications. A huge number of studies have revealed the association between miRNAs and diabetic complications, including diabetic nephropathy, cardiomyopathy, neuropathy, retinopathy, and delayed wound healing. To address this issue, recent studies have focused on the use of polyphenols as selective and safe drugs in the treatment of diabetes complications. In this article, we will review the involvement of miRNAs in diabetic complications' occurrence or development. Finally, we will review the latest findings on targeting miRNAs by polyphenols like curcumin, resveratrol, and quercetin for diabetic complications therapy.

MicroRNAs in kidney injury and disease

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by degrading or repressing the translation of their target messenger RNAs. As miRNAs are critical regulators of cellular homeostasis, their dysregulation is a crucial component of cell and organ injury. A substantial body of evidence indicates that miRNAs are involved in the pathophysiology of acute kidney injury (AKI), chronic kidney disease and allograft damage. Different subsets of miRNAs are dysregulated during AKI, chronic kidney disease and allograft rejection, which could reflect differences in the physiopathology of these conditions. miRNAs that have been investigated in AKI include miR-21, which has an anti-apoptotic role, and miR-214 and miR-668, which regulate mitochondrial dynamics. Various miRNAs are downregulated in diabetic kidney disease, including the miR-30 family and miR-146a, which protect against inflammation and fibrosis. Other miRNAs such as miR-193 and miR-92a induce podocyte dedifferentiation in glomerulonephritis. In transplantation, miRNAs have been implicated in allograft rejection and injury. Further work is needed to identify and validate miRNAs as biomarkers of graft function and of kidney disease development and progression. Use of combinations of miRNAs together with other molecular markers could potentially improve diagnostic or predictive power and facilitate clinical translation. In addition, targeting specific miRNAs at different stages of disease could be a promising therapeutic strategy.

LncRNA NEAT1/microRNA‑124 regulates cell viability, inflammation and fibrosis in high‑glucose‑treated mesangial cells

Long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) has been frequently found to be dysregulated, which contributes to diabetes-related complications. The present study aimed to explore the effect of knockdown on mouse mesangial cell (MMC) viability, apoptosis, inflammation and fibrosis in an in vitro model of diabetic nephropathy (DN). The SV40 MES13 MMC cell line was first cultured with high glucose to establish an in vitro MMC DN cell model. Lnc-NEAT1 shRNA or the negative control shRNA were transfected into MMC DN cells, followed by the measurement of cell viability, apoptosis, inflammation, fibrosis and microRNA (miR)-124 expression, a known target of lnc-NEAT1, using Cell Counting Kit-8, flow cytometry, ELISA, western blotting [Capain1 (capn1), β-catenin (CTNNB1), cleaved caspase 3, cleaved poly-(ADP ribose) polymerase, fibronectin and Collagen] and reverse transcription-quantitative PCR (Capn1, CTNNB1, lnc-NEAT1, fibronectin, collagen and miR-124), respectively. In rescue experiments, the miR-124 and negative control inhibitor were co-transfected into lnc-NEAT1-downregulated cells, following which cell viability, apoptosis, inflammation, fibrosis, capn1 and CTNNB1 expression were measured. Lnc-NEAT1 expression was increased in high glucose-treated cells compared with that in normal glucose-treated cells and osmotic control cells, suggesting that lnc-NEAT1 is overexpressed in the MMC DN cell model. In the MMC DN cell model, lncRNA-NEAT1 knockdown enhanced cell apoptosis but reduced cell viability and the secretion of inflammatory cytokines in the supernatant (IL-1β, IL-8, monocyte chemotactic protein 1 and TNF-α), in addition to reducing the expression of fibrosis markers fibronectin and collagen I in the lysates. Lnc-NEAT1 knockdown increased miR-124 expression. Furthermore, transfection with the miR-124 inhibitor reduced cell apoptosis but increased cell viability, inflammation and fibrosis in lnc-NEAT1-downregulated MMC DN cells. miR-124 inhibitor transfection also increased the expression levels of Capn1 and CTNNB1. Taken together, the findings of the present study demonstrated that lnc-NEAT1 knockdown was able to attenuate MMC viability, inflammation and fibrosis by regulating miR-124 expression and the Capn1/β-catenin signaling pathway downstream. Therefore, Lnc-NEAT1 may serve as a potential therapeutic target for DN.

Mechanism of circHIPK3-miRNA-124-3p/miRNA-148b-3p-Mediated Inflammatory Responses and Cell Senescence in Candida albicans-Induced Septic Acute Kidney Injury

INTRODUCTION

Sepsis is a life-threatening inflammatory state that can result in septic acute kidney injury (SAKI). Circular RNAs (circRNAs) are implicated in various inflammatory diseases including SAKI. This study investigated the effect of circHIPK3 on inflammatory responses and cell senescence in Candida albicans-induced SAKI.

METHODS

circHIPK3 expression and inflammatory factors in the serum of SAKI patients and healthy volunteers were detected. The murine and cell models of SAKI were established by C. albicans and lipopolysaccharide induction, respectively. The effect of circHIPK3 on SAKI inflammatory responses and cell senescence was measured using ELISA, SA-β-gal staining, CCK-8, RT-qPCR, and Western blot. The binding relationships among circHIPK3, miR-124-3p, or miR-148b-3p and KLF6 or DNMT1/3a were confirmed. The binding of KLF6 and NLRP3 was determined, and the methylation level of the Klotho promoter was detected. Functional rescue experiments were performed to verify the effect of miR-124-3p or miR-148b-3p on SAKI.

RESULTS

circHIPK3 was highly expressed in SAKI. circHIPK3 silencing alleviated kidney injury in SAKI mice and enhanced SAKI cell viability by alleviating inflammatory responses and cell senescence. Mechanically, circHIPK3 upregulated KLF6 expression by competitively binding to miR-124-3p, thereby promoting the binding of KLF6 and NLRP3, activating NLRP3/caspase-1-mediated pyroptosis, and eventually aggravating SAKI inflammatory responses. circHIPK3 upregulated DNMT1/3a expression by competitively binding to miR-148b-3p, thus elevating the methylation level of Klotho promoter and accelerating SAKI cell senescence. Downregulation of miR-124-3p or miR-148b-3p attenuated the protective effect of circHIPK3 silencing on SAKI.

CONCLUSION

circHIPK3 aggravated SAKI inflammatory responses via miR-124-3p/KLF6 and accelerated SAKI cell senescence via miR-148b-3p/DNMT1/3a.

Emodin Promotes Autophagy and Prevents Apoptosis in Sepsis-Associated Encephalopathy through Activating BDNF/TrkB Signaling

OBJECTIVE

Sepsis-associated encephalopathy (SAE) is a severe and common complication of sepsis and can induce cognitive dysfunction and apoptosis of neurons and neuroinflammation. Emodin has been confirmed to have anti-inflammatory effects. Thus, we sought to investigate the role of Emodin in SAE.

METHODS

The cecal ligation and puncture (CLP) method was used for the establishment of SAE in mice model. For treatment of Emodin, intraperitoneal injection of 20 mg/kg Emodin was performed before the surgery. The Morris water maze and open field tests were carried for measurement of cognitive dysfunction. Hematoxylin and eosin staining was for histological analysis of hippocampus. Cell apoptosis of hippocampus neurons was measured by TUNEL staining. Pro-inflammatory and anti-inflammatory cytokines in hippocampus tissue homogenate were evaluated by ELISA. BDNF/TrkB signaling-related proteins (TrkB, p-TrkB, and BDNF), autophagy-related proteins (LC3 II/I and Beclin-1), and apoptosis-related proteins (Bax, Bcl-2, and cleaved caspase-3) were detected by Western blotting.

RESULTS

Emodin significantly inhibited apoptosis and induced autophagy in hippocampal neurons of CLP-treated mice. In addition, Emodin significantly ameliorated CLP-induced cognitive dysfunction and pathological injury in mice. Meanwhile, Emodin notably inhibited CLP-induced inflammatory responses in mice via upregulation of BDNF/TrkB signaling, while the effect of Emodin was partially reversed in the presence of K252a (BDNF/TrkB signaling inhibitor).

CONCLUSION

Emodin significantly inhibited the progression of SAE via mediation of BDNF/TrkB signaling. Thus, Emodin might serve as a new agent for SAE treatment.

MiR-124 Negatively Regulated PARP1 to Alleviate Renal Ischemia-reperfusion Injury by Inhibiting TNFα/RIP1/RIP3 Pathway

Renal ischemia-reperfusion injury (IRI) is one of the underlying causes of acute kidney injury and also an unavoidable problem in renal transplantation. Lots of miRNAs and targets have been found to participate in some post-transcriptional processes in renal IRI, however, the detailed knowledge of miRNA targets and mechanism is unknown. In this study, miR-124 was found inhibited and PARP1 was overexpressed in renal IRI cells and mouse models. Dual-luciferase reporter assay revealed that miR-124 post-transcriptionally regulated PAPR1 3′UTR activity. Our results also demonstrated miR-124 negatively regulated PARP1 which played a role in necroptosis of renal ischemia-reperfusion injury by activating TNFα. TNFα induced the RIP1/RIP3 necroptosis signaling pathway to aggravate the renal injury. Collectively, these studies identified PARP1 as a direct target of miR-124 and activated RIP1/RIP3 necroptosis signaling pathway through TNFα. It elucidated the protective effect of miR-124 in renal ischemia-reperfusion injury, which demonstrated the regulatory mechanism of miR-124/PARP1 in renal injury and exhibited the potential as a novel therapeutic for the treatment of renal IRI.

Exosome-mediated pyroptosis of miR-93-TXNIP-NLRP3 leads to functional difference between M1 and M2 macrophages in sepsis-induced acute kidney injury

Sepsis is a systemic inflammatory response syndrome caused by infection, resulting in organ dysfunction. Sepsis-induced acute kidney injury (AKI) is one of the most common potential complications. Increasing reports have shown that M1 and M2 macrophages both take part in the progress of AKI by influencing the level of inflammatory factors and the cell death, including pyroptosis. However, whether M1 and M2 macrophages regulate AKI by secreting exosome remains unknown. In the present study, we isolated the exosomes from M1 and M2 macrophages and used Western blot and enzyme-linked immunosorbent assay (ELISA) to investigate the effect of M1 and M2 exosomes on cell pyroptosis. miRNA sequencing was used to identify the different miRNA in M1 and M2 exosomes. Luciferase reporter assay was used to verify the target gene of miRNA. We confirmed that exosomes excreted by macrophages regulated cell pyroptosis in vitro by using Western blot and ELISA. miRNA sequencing revealed the differentially expressed level of miRNAs in M1 and M2 exosomes, among which miR-93-5p was involved in the regulation of pyroptosis. By using bioinformatics predictions and luciferase reporter assay, we found that thioredoxin-interacting protein (TXNIP) was a direct target of miR-93-5p. Further in vitro and in vivo experiments indicated that exosomal miR-93-5p regulated the TXNIP directly to influence the pyroptosis in renal epithelial cells, which explained the functional difference between different phenotypes of macrophages. This study might provide new targets for the treatment of sepsis-induced AKI.

Eriocitrin attenuates ischemia reperfusion-induced oxidative stress and inflammation in rats with acute kidney injury by regulating the dual-specificity phosphatase 14 (DUSP14)-mediated Nrf2 and nuclear factor-κB (NF-κB) pathways

Background

Ischemia reperfusion (IR)-induced acute kidney injury (AKI) is accompanied by increased inflammatory response and oxidative stress. Eriocitrin is a flavonoid that is mainly derived from lemon or citrate juice. It exhibits various pharmacological effects and is known to have antioxidant and anti-steatotic benefits. However, research on the effect of eriocitrin against IR-induced oxidative stress and inflammation in AKI is limited.

Methods

In this study, an OGD/R of HK-2 cell in vitro and rat model of AKI in vivo were constructed. Then the cell or rats were treated with eriocitrin at different doses (60, 30, 10 mg/kg). The levels of apoptotic were detected by flow cytometry. Inflammatory and oxidative stress factors in supernatant in vitro and tissue in vivo. Meanwhile, Western blot was used to detect the change of dual-specificity phosphatase 14 (DUSP14), Nrf2 and nuclear factor-κB (NF-κB).

Results

Eriocitrin attenuated apoptosis of the human renal tubular epithelial cell line HK-2 mediated by oxygen glucose deprivation/reperfusion via the repression of inflammation and oxidative stress in a dose-dependent manner. Eriocitrin also enhanced the levels of dual-specificity phosphatase 14 (DUSP14) and Nrf2, and decreased NF-κB phosphorylation. Furthermore, the in vivo experiments indicated that eriocitrin dose-dependently alleviated IR-induced AKI and apoptosis in rats. By elevating DUSP14, eriocitrin promoted the expression of Nrf2 and inactivated NF-κB, thereby downregulating inflammation and oxidative stress. Moreover, inhibiting DUSP14 expression with protein tyrosine phosphatase (PTP) inhibitor IV reversed the kidney-protective effects of Eriocitrin.

Conclusions

Eriocitrin protected IR-induced AKI by attenuating oxidative stress and inflammation via elevating DUSP14, thereby providing a theoretical basis for the treatment of IR-induced AKI.

Clinical efficacy of combination therapy of itraconazole and prednisolone for treating effusive feline infectious peritonitis

A 3-month-old male Scottish Fold kitten with pleural fluid and low ratio of albumin to globulin (A/G ratio) was brought to our small animal hospital. Since RNA from the type I feline coronavirus (FCoV) were detected in drained pleural fluid, the cat was tentatively diagnosed with effusive feline infectious peritonitis (FIP). Following the administration of itraconazole and prednisolone, the A/G ratio increased, and the pleural fluid mostly disappeared. The fecal FCoV levels temporarily decreased. However, the cat showed neurological manifestations and was eventually euthanized due to status epilepticus after 38 days of treatment. In conclusion, itraconazole partly exerted a beneficial effect in a cat with FIP. However, further investigation of a possible role of itraconazole in FIP treatment is warranted.

Xuebijing Injection Maintains GRP78 Expression to Prevent Candida albicans-Induced Epithelial Death in the Kidney

Sepsis and septic shock threaten the survival of millions of patients in the intensive care unit. Secondary fungal infections significantly increased the risk of mortality in sepsis patients. Chinese medicine Xuebijing injection (XBJ) has been routinely used as an add-on treatment to sepsis and septic shock in China. Our network pharmacology analysis predicted that XBJ also influences fungal infection, consisting with results of pioneer clinical studies. We conducted in vivo and in vitro experiments to verify this prediction. To our surprise, XBJ rescued mice from lethal Candida sepsis in a disseminated Candida albicans infection model and abolished the colonization of C. albicans in kidneys. Although XBJ did not inhibit the growth and the virulence of C. albicans in vitro, it enhanced the viability of 293T cells upon C. albicans insults. Further RNA-seq analysis revealed that XBJ activated the endoplasmic reticulum (ER) stress pathway upon C. albicans infection. Western blot confirmed that XBJ maintained the expression of GRP78 in the presence of C. albicans. Interestingly, key active ingredients in XBJ (C0127) mirrored the effects of XBJ. C0127 not only rescued mice from lethal Candida sepsis and prevented the colonization of C. albicans in kidneys, but also sustained the survival of kidney epithelial cells partially by maintaining the expression of GRP78. These results suggested that XBJ may prevent fungal infection in sepsis patients. Pre-activation of ER stress pathway is a novel strategy to control C. albicans infection. Network pharmacology may accelerate drug development in the field of infectious diseases.

Regulatory Factor X1 Downregulation Contributes to Monocyte Chemoattractant Protein-1 Overexpression in CD14+ Monocytes via Epigenetic Mechanisms in Coronary Heart Disease

Monocyte chemoattractant protein 1 (MCP1) affects the chemotaxis of monocytes and is a key chemokine closely related to the development of atherosclerosis (AS). Compared with healthy controls, coronary heart disease (CAD) patients show significantly upregulated plasma concentrations and mRNA expression of MCP1 in CD14+ monocytes. However, the specific regulatory mechanism of MCP1 overexpression in AS is still unclear. Our previous research indicated that there was no significant difference in the H3K4 and H3K27 tri-methylation of the MCP1 promoter in CD14+ monocytes from CAD versus non-CAD patients, but the H3 and H4 acetylation of the MCP1 promoter was increased in CD14+ monocytes from CAD patients. We further found that the H3K9 tri-methylation of the MCP1 promoter in CD14+ monocytes from CAD patients was decreased, but the DNA methylation levels did not differ markedly from those in non-CAD patients. Our previous work showed that the level of regulatory factor X1 (RFX1) was markedly reduced in CD14+ monocytes from CAD patients and played an important role in the progression of AS by regulating epigenetic modification. In this study, we investigated whether RFX1 and epigenetic modifications mediated by RFX1 contribute to the overexpression of MCP1 in activated monocytes in CAD patients. We found that the enrichment of RFX1, histone deacetylase 1 (HDAC1), and suppressor of variegation 3–9 homolog 1 (SUV39H1) in the MCP1 gene promoter region were decreased in CD14+ monocytes from CAD patients and in healthy CD14+ monocytes treated with low-density lipoprotein (LDL). Chromatin immunoprecipitation (ChIP) assays identified MCP1 as a target gene of RFX1. Overexpression of RFX1 increased the recruitments of HDAC1 and SUV39H1 and inhibited the expression of MCP1 in CD14+ monocytes. In contrast, knockdown of RFX1 in CD14+ monocytes reduced the recruitments of HDAC1 and SUV39H1 in the MCP1 promoter region, thereby facilitating H3 and H4 acetylation and H3K9 tri-methylation in this region. In conclusion, our results indicated that RFX1 expression deficiency in CD14+ monocytes from CAD patients contributed to MCP1 overexpression via a deficiency of recruitments of HDAC1 and SUV39H1 in the MCP1 promoter, which highlighted the vital role of RFX1 in the pathogenesis of CAD.

Honokiol alleviates sepsis-induced acute kidney injury in mice by targeting the miR-218-5p/heme oxygenase-1 signaling pathway

Background

Honokiol is a low-molecular-weight natural product and has been reported to exhibit anti-inflammatory activity.

Objectives

Our study aimed to investigate the influence of honokiol on sepsis-induced acute kidney injury (AKI) in a mouse model.

Material and methods

A cecal ligation and puncture (CLP) surgical operation was performed to establish a sepsis-induced acute kidney injury model in mice. Renal histomorphological analysis was performed with periodic acid-Schiff (PAS) staining. The levels of inflammatory markers in serum were measured by ELISA assay. The mRNA and protein levels were assayed by RT-qPCR and western blotting, respectively. Annexin V-FITC/PI staining was used to evaluate glomerular mesangial cell (GMC) apoptosis.

Results

The results revealed that honokiol significantly increased the survival rate in mice undergoing a CLP operation. Inflammatory cytokines, such as TNF-α, IL-6 and IL-1β, were significantly inhibited in honokiol-treated septic mice compared with the CLP group. In addition, honokiol showed the ability to reverse CLP-induced AKI in septic mice. Furthermore, heme oxygenase-1 (HO-1) expression levels were significantly up-regulated and miR-218-5p was markedly down-regulated in honokiol-treated septic mice as compared to CLP-operated mice. Bioinformatics and experimental measurements showed that HO-1 was a direct target of miR-218-5p. In vitro experiments showed that both honokiol and miR-218-5p inhibitors blocked lipopolysaccharide (LPS)-induced cell growth inhibition and GMC apoptosis by increasing the expression of HO-1.

Conclusions

Honokiol ameliorated AKI in septic mice and LPS-induced GMC dysfunction, and the underlying mechanism was mediated, at least partially, through the regulation of miR-218-5p/HO-1 signaling.

Electronic supplementary material

The online version of this article (10.1186/s11658-019-0142-4) contains supplementary material, which is available to authorized users.