miR-129-5p alleviates LPS-induced acute kidney injury via targeting HMGB1/TLRs/NF-kappaB pathway

Future embracing: exosomes driving a revolutionary approach to the diagnosis and treatment of idiopathic membranous nephropathy

Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults and is associated with high rates of end-stage renal disease. Early detection and precise interventions are crucial for improving patient prognosis and quality of life. However, the current diagnosis primarily relies on renal biopsies and traditional biomarkers, which have limitations. Additionally, targeted therapeutic strategies are lacking. Exosomes, small vesicles that facilitate intercellular communication, have emerged as potential noninvasive diagnostic markers due to their stability, diverse cargo, and rapid detectability. They also hold promise as carriers for gene and drug delivery, presenting innovative opportunities in renal disease prognosis and treatment. However, research on exosomes in the context of idiopathic membranous nephropathy (IMN) remains limited, with a focus on exploring urinary exosomes as IMN markers. In this review, we summarize the current status of MN diagnosis and treatment, highlight the fundamental characteristics of exosomes, and discuss recent advancements in their application to IMN diagnosis and therapy. We provide insights into the clinical prospects of exosomes in IMN and acknowledge potential challenges. This article aims to offer forward-looking insights into the future of exosome-mediated IMN diagnosis and treatment, indicating a revolutionary transformation in this field.

Circ_0001714 knockdown alleviates lipopolysaccharide-induced apoptosis and inflammation in renal tubular epithelial cells via miR-129-5p/TRAF6 axis in septic acute kidney injury

BACKGROUND

Circular RNAs (circRNAs) have been shown to play roles in regulating sepsis. Sepsis is a major cause of acute kidney injury (AKI). Herein, we aimed to investigate the role and mechanism of circ_0001714 in the progression of sepsis-induced AKI.

METHODS

Human HK-2 cells were exposed to lipopolysaccharide (LPS) for functional experiments. Quantitative real-time polymerase chain reaction and western blotting were used for expression analysis. Functional experiments were performed by using MTT assay, 5-ethynyl-2'-deoxyuridine assay, flow cytometry, and enzyme-linked immunosorbent assay (ELISA). The binding between miR-129-5p and circ_0001714 or TRAF6 (TNF receptor associated factor 6) was validated using dual-luciferase reporter assay.

RESULTS

Circ_0001714 expression was higher in sepsis-AKI patients. HK-2 cells were exposed to LPS to imitate the injury of renal tubular epithelial cells during sepsis-AKI. LPS dose-dependently up-regulated circ_0001714, moreover, circ_0001714 silencing reversed LPS-evoked apoptosis and inflammation in HK-2 cells. Mechanistically, circ_0001714 sequestered miR-129-5p to up-regulate TRAF6 expression, implying the circ_0001714/miR-129-5p/TRAF6 feedback loop. MiR-129-5p was decreased, while TRAF6 was increased in sepsis-AKI patients and LPS-stimulated HK-2 cells. MiR-129-5p re-expression or TRAF6 silencing protected against LPS-induced HK-2 cell apoptosis and inflammation. Additionally, a series of rescue experiments showed that miR-129-5p inhibition reversed the inhibitory action of circ_0001714 knockdown on LPS-induced HK-2 cell injury. Furthermore, TRAF6 overexpression also attenuated the protective effects of miR-129-5p on HK-2 cells under LPS treatment.

CONCLUSION

Circ_0001714 silencing might alleviate LPS-induced apoptosis and inflammation via targeting miR-129-5p/TRAF6 axis in HK-2 cells.

Long noncoding RNA MALAT1 inhibition attenuates sepsis-induced acute lung injury through modulating the miR-129-5p/PAX6/ZEB2 axis

This research aimed to investigate the role of the long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/microRNA-129-5p (miR-129-5p)/paired box gene 6 (PAX6) axis in sepsis-induced acute lung injury (ALI). MLE-12 cells and C57BL/6 mice were induced by LPS to establish lung injury in in vitro and in vivo models. Cell viability and apoptosis were measured by cell counting kit-8 assay and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining, respectively. Levels of inflammatory cytokines in cell supernatants and bronchoalveolar lavage fluid (BALF) were detected by ELISA. Lung injury was evaluated by lung wet weight-to-dry weight ratio and hematoxylin-eosin staining. MALAT1, PAX6, and zinc finger E-box-binding homeobox 2 (ZEB2) expression was elevated and miR-129-5p expression was reduced in the serum of patients with sepsis-induced ALI, LPS-induced MLE-12 cells, and lung tissues of ALI mice. MALAT1 interference delayed the LPS-induced cell proliferation decrease, apoptosis increase, and inflammatory factor increase. miR-129-5p inhibition could reverse the delaying effect of MALAT1 interference on LPS-induced lung cell injury. PAX6 overexpression (oe) reversed the inhibitory effect of miR-129-5p oe on LPS-induced lung cell injury. Downregulating MALAT1 reduced pulmonary edema, inflammatory cytokine levels, lung injury, and apoptosis in ALI mice. Moreover, miR-129-5p suppression or PAX6 oe reversed the delaying effect of MALAT1 interference on sepsis-induced ALI. MALAT1 aggravates sepsis-induced ALI via the miR-129-5p/PAX6/ZEB2 axis.

MicroRNAs in septic acute kidney injury

Sepsis is a potentially fatal complication of burns and trauma that can cause acute kidney injury (AKI) with substantial morbidity and mortality, but this disease is poorly understood. Despite medical advances, effective therapeutic regimens for septic AKI remain uncommon. MicroRNAs (miRNAs) are endogenous non-coding RNAs that influence the translation of target messenger RNAs in a variety of biological processes. Emerging evidence has shown that miRNAs are intimately associated with septic AKI. The goal of this review was to summarize recent advances in the profound understanding of the functional role of miRNAs in septic AKI, as well as to provide new insights into miRNAs as feasible biomarkers and therapeutic targets for septic AKI.

Multifunctional mesoporous silica-cerium oxide nanozymes facilitate miR129 delivery for high-quality healing of radiation-induced skin injury

Radiation-induced skin injury (RISI) is an important challenge for clinical treatments. The main causes of RISI include hypoxia in the wound microenvironment, reactive oxygen species (ROS) activation, and downregulation of DNA repair proteins. Here, a multiple radioresistance strategy was designed for microRNA therapy and attenuating hypoxia. A novel mesoporous silica (MS) firmly anchored and dispersed cerium (IV) oxide (CeO₂) nanoparticles to form MS-CeO₂ nanocomposites, which exhibit superior activity in inhibiting radiation-induced ROS and HIF-1α activation and ultimately promote RISI wound healing. The miR129 serum concentrations in patients can promote radioresistance by directly targeting RAD17 and regulating the Chk2 pathway. Subsequently, MS-CeO₂ nanocomposites with miR129 were conjugated with iRGD-grafted polyoxyethylene glycol (short for nano-miR129), which increased the stability and antibacterial character, efficiently delivered miR129 to wound blood capillaries, and exhibited low toxicity. Notably, nano-miR129 promoted radioresistance and enhanced anti-ROS therapeutic efficacy in a subcutaneous RISI mouse model. Overall, this MS-CeO₂ nanozyme and miR129-based multiresistance radiotherapy protection strategy provided a promising therapeutic approach for RISI.

Apigenin and apigenin-7, 4'-O-dioctanoate protect against acrolein-aggravated inflammation via inhibiting the activation of NLRP3 inflammasome and HMGB1/MYD88/NF-κB signaling pathway in Human umbilical vein endothelial cells (HUVEC)

Exposure to acrolein, one environmental and dietary pollutant, has been shown to cause inflammation. Here, we reported for the first time that acrolein aggravated lipopolysaccharide (LPS)-induced inflammation in Human umbilical vein endothelial cells (HUVEC) as evidenced by the further increased mRNA expression of three pro-inflammatory cytokines, including interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Acrolein also further increased the generation of reactive oxygen species (ROS) and decreased the activity of glutathione peroxidase (GSH-Px) in LPS-pretreated HUVEC. Moreover, acrolein treatment further increased the nucleotide oligomerization domain-like receptor protein 3 (NLRP3) and apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) expression, caspase-1 cleavage, and downstream matures interleukin 18 (IL-18) and IL-1β level in LPS-pretreated HUVEC. Acrolein treatment also further increased the expressions of high-mobility group box 1 (HMGB1), toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and phospho-NF-κB P65 (P-P65) in the LPS pre-treated HUVEC. Thus, acrolein aggravated LPS-induced HUVEC inflammation through induction of oxidative stress, and activation of NLRP3 inflammasome and HMGB1/MYD88/NF-κB signaling pathway. In addition, apigenin and apigenin-7, 4'-O-dioctanoate attenuated acrolein-aggravated inflammation by targeting the above signaling pathways. Our findings could help to develop potential therapeutic strategies against acrolein-enhanced inflammation.

Modes of action and diagnostic value of miRNAs in sepsis

Sepsis is a clinical syndrome defined as a dysregulated host response to infection resulting in life-threatening organ dysfunction. Sepsis is a major public health concern associated with one in five deaths worldwide. Sepsis is characterized by unbalanced inflammation and profound and sustained immunosuppression, increasing patient susceptibility to secondary infections and mortality. microRNAs (miRNAs) play a central role in the control of many biological processes, and deregulation of their expression has been linked to the development of oncological, cardiovascular, neurodegenerative and metabolic diseases. In this review, we discuss the role of miRNAs in sepsis pathophysiology. Overall, miRNAs are seen as promising biomarkers, and it has been proposed to develop miRNA-based therapies for sepsis. Yet, the picture is not so straightforward because of the versatile and dynamic features of miRNAs. Clearly, more research is needed to clarify the expression and role of miRNAs in sepsis, and to promote the use of miRNAs for sepsis management.

HMGB1 is a critical molecule in the pathogenesis of Gram-negative sepsis

Gram-negative sepsis is a severe clinical syndrome associated with significant morbidity and mortality. Lipopolysaccharide (LPS), expressed on Gram-negative bacteria, is a potent pro-inflammatory toxin that induces inflammation and coagulation via two separate receptor systems. One is Toll-like receptor 4 (TLR4), expressed on cell surfaces and in endosomes, and the other is the cytosolic receptor caspase-11 (caspases-4 and -5 in humans). Extracellular LPS binds to high mobility group box 1 (HMGB1) protein, a cytokine-like molecule. The HMGB1-LPS complex is transported via receptor for advanced glycated end products (RAGE)-endocytosis to the endolysosomal system to reach the cytosolic LPS receptor caspase-11 to induce HMGB1 release, inflammation, and coagulation that may cause multi-organ failure. The insight that LPS needs HMGB1 assistance to generate severe inflammation has led to successful therapeutic results in preclinical Gram-negative sepsis studies targeting HMGB1. However, to date, no clinical studies have been performed based on this strategy. HMGB1 is also actively released by peripheral sensory nerves and this mechanism is fundamental for the initiation and propagation of inflammation during tissue injury. Homeostasis is achieved when other neurons actively restrict the inflammatory response via monitoring by the central nervous system and the vagus nerve through the cholinergic anti-inflammatory pathway. The neuronal control in Gram-negative sepsis needs further studies since a deeper understanding of the interplay between HMGB1 and acetylcholine may have beneficial therapeutic implications. Herein, we review the synergistic overlapping mechanisms of LPS and HMGB1 and discuss future treatment opportunities in Gram-negative sepsis.

The Intersection of Acute Kidney Injury and Non-Coding RNAs: Inflammation

Acute renal injury (AKI) is a complex clinical syndrome, involving a series of pathophysiological processes, in which inflammation plays a key role. Identification and verification of gene signatures associated with inflammatory onset and progression are imperative for understanding the molecular mechanisms involved in AKI pathogenesis. Non-coding RNAs (ncRNAs), involved in epigenetic modifications of inflammatory responses, are associated with the aberrant expression of inflammation-related genes in AKI. However, its regulatory role in gene expression involves precise transcriptional regulation mechanisms which have not been fully elucidated in the complex and volatile inflammatory response of AKI. In this study, we systematically review current research on the intrinsic molecular mechanisms of ncRNAs that regulate the inflammatory response in AKI. We aim to provide potential research directions and strategies for developing ncRNA-targeted gene therapies as an intervention for the inflammatory damage in AKI.

High Mobility Group Proteins in Sepsis

Sepsis, a systemic inflammatory response disease, is the most severe complication of infection and a deadly disease. High mobility group proteins (HMGs) are non-histone nuclear proteins binding nucleosomes and regulate chromosome architecture and gene transcription, which act as a potent pro-inflammatory cytokine involved in the delayed endotoxin lethality and systemic inflammatory response. HMGs increase in serum and tissues during infection, especially in sepsis. A growing number of studies have demonstrated HMGs are not only cytokines which can mediate inflammation, but also potential therapeutic targets in sepsis. To reduce sepsis-related mortality, a better understanding of HMGs is essential. In this review, we described the structure and function of HMGs, summarized the definition, epidemiology and pathophysiology of sepsis, and discussed the HMGs-related mechanisms in sepsis from the perspectives of non-coding RNAs (microRNA, long non-coding RNA, circular RNA), programmed cell death (apoptosis, necroptosis and pyroptosis), drugs and other pathophysiological aspects to provide new targets and ideas for the diagnosis and treatment of sepsis.

Long non-coding RNA ZFY-AS1 represses periodontitis tissue inflammation and oxidative damage via modulating microRNA-129-5p/DEAD-Box helicase 3 X-linked axis

A large number of studies have manifested long non-coding RNA (lncRNA) is involved in the modulation of the development of periodontitis, but the specific mechanism has not been fully elucidated. The purpose of this study was to explore the biological function and latent molecular mechanism of lncZFY-AS1 in periodontitis. The results clarified lncZFY-AS1 and DEAD-Box Helicase 3 X-Linked (DDX3X) were up-regulated, but microRNA (miR)-129-5p was down-regulated in periodontitis. Knockdown of lncZFY-AS2 or overexpression of miR-129-5p decreased macrophage infiltration and periodontal membrane cell apoptosis, increased cell viability, repressed inflammatory factors and nuclear factor kappa B activation, reduced oxidative stress, but promoted nuclear factor-E2-related factor 2/heme oxygenase 1 expression. LncZFY-AS1 elevation further aggravated periodontitis inflammation, oxidative stress, and apoptosis. LncZFY competitively adsorbed miR-129-5p to mediate DDX3X expression. Knockdown lncZFY’s improvement effect on periodontitis was reversed by depressive miR-129-5p or enhancive DDX3X. In conclusion, these data suggest lncZFY-AS1 promotes inflammatory injury and oxidative stress in periodontitis by competitively binding to miR-129-5p and mediating DDX3X expression. LncZFY-AS1/miR-129-5p/DDX3X may serve as a novel molecular target for treatment of periodontitis in the future.

MiR-129-5p Inactivates NF-κB Pathway to Block Rheumatoid Arthritis Development via Targeting BRD4

Methods

The abundance of miR-129-5p was detected in the samples including normal tissues and RA tissues and cell lines including human fibroblast-like synoviocytes (hFLSs) and human rheumatoid arthritis fibroblast-like synoviocytes (RA-FLSs). The CCK-8 assay, flow cytometry, Transwell, and ELISA were used to observe the effects of miR-129-5p on the phenotype of RA-FLSs. Moreover, the potential targets of miR-129-5p were identified with TargetScan and dual-luciferase reporter gene assay. Besides, the abundances of the proteins were analyzed with western blot.

Results

Decreased miR-129-5p was observed in RA tissues and cells. Increased miR-129-5p obviously blocked the proliferation, inflammatory stress, and migration and remarkably promoted cellular apoptosis. Moreover, BRD4 was confirmed as targets of miR-129-5p, and BRD4 upregulation could partly rescue the inhibition of miR-129-5p on aggressive behaviors of RA-FLSs. Besides, the finding of this study also proved that upregulated miR-129-5p could impede the NF-κB pathway via targeting BRD4.

Conclusion

This study suggests that miR-129-5p suppresses the activation of NF-κB pathway to block the progression of RA via targeting BRD4.

Non-Coding RNAs in Sepsis-Associated Acute Kidney Injury

Sepsis is a systemic inflammatory response caused by a severe infection that leads to multiple organ damage, including acute kidney injury (AKI). In intensive care units (ICU), the morbidity and mortality associated with sepsis-associated AKI (SA-AKI) are gradually increasing due to lack of effective and early detection, as well as proper treatment. Non-coding RNAs (ncRNAs) exert a regulatory function in gene transcription, RNA processing, post-transcriptional translation, and epigenetic regulation of gene expression. Evidence indicated that miRNAs are involved in inflammation and programmed cell death during the development of sepsis-associated AKI (SA-AKI). Moreover, lncRNAs and circRNAs appear to be an essential regulatory mechanism in SA-AKI. In this review, we summarized the molecular mechanism of ncRNAs in SA-AKI and discussed their potential in clinical diagnosis and treatment.

Down-regulated HDAC1 and up-regulated microRNA-124-5p recover myocardial damage of septic mice

Studies have revealed the relationship between histone deacetylases (HDACs)/microRNAs (miRNAs) and sepsis, but little has ever investigated the mechanism of HDAC1/miR-124-5p in sepsis. Herein, we studied the impacts of HDAC1/miR-124-5p on myocardial damage of septic mice via regulating high-mobility group box chromosomal protein 1 (HMGB1). Septic mice were induced by cecal ligation and puncture. HDAC1, miR-124-5p and HMGB1 expression in myocardial tissues of septic mice were detected. Septic mice were injected with HDAC1 low expression-, miR-124-5p high expression- or HMGB1 low expression-related structures to observe cardiac function, inflammatory response, oxidative stress response, myocardial pathological changes and apoptosis in myocardial tissues of septic mice. The relationship of HDAC1/miR-124-5p/HMGB1 was verified. HDAC1 and HMGB1 expression were upregulated while miR-124-5p expression was decreased in myocardial tissues of septic mice. Restored miR-124-5p/depleted HDAC1 or HMGB1 recovered the cardiac function, improved cardiac function, inflammatory response, oxidative stress response, myocardial pathological changes and inhibit ed cardiomyocyte apoptosis in septic mice. HDAC1 bound to miR-124-5p which directly targeted HMGB1. This study suggests that down-regulated HDAC1 or up-regulated miR-124-5p recovers myocardial damage of septic mice via decreasing HMGB1.

Effects of real-ambient PM2.5 exposure plus lipopolysaccharide on multiple organ damage in mice

Background: The toxicological effects of fine particulate matter (PM_2.5) on the cardiopulmonary and nervous systems have been studied widely, whereas the study of PM_2.5 on systemic toxicity is not in-depth enough. Lipopolysaccharide (LPS) can cause multiple organ damage. The combined effects of co-exposure of PM_2.5 plus LPS on the stomach, spleen, intestine, and kidney are still unclear. Purpose: This study was aimed to explore the toxicological effects of co-exposure of PM_2.5 and LPS on the different organs of mice. Research Design and Study Sample Using a real-ambient PM_2.5 exposure system and an intraperitoneal LPS injection mouse model, we investigated multiple organ damage effects on male BALB/c mice after co-exposure of PM_2.5 plus LPS for 23 weeks in Linfen, a city with a high PM_2.5 concentration in China. Data Collection: Eosin-hematoxylin staining, ELISA and the biochemical assay analysed the toxicological effects. Results: The pathological tissue injury on the four organs above appeared in mice co-exposed to PM_2.5 plus LPS, accompanied by the body weight and stomach organ coefficient abnormality, and significant elevation of pro-inflammatory cytokines levels, oxidative stress in the spleen and kidney, and levels of kidney injury molecule (KIM-1) increase in the kidney. There were tissue differences in the pathological damage and toxicological effects on mice after co-exposure, in which the spleen and kidney were more sensitive to pollutants. In the PM_2.5 + LPS group, the superoxide dismutase inhibition and catalase (CAT) activity promotion in the kidney or spleen of mice were significant relative to the PM_2.5 group; the CAT and interleukin-6 (IL-6) levels in the spleen were raised considerably compared with the LPS group. Conclusions: These findings suggested the severity and sensitivity of multiple organ injuries in mice in response to PM_2.5 plus LPS.

Tacrolimus alleviates LPS-induced AKI by inhibiting TLR4/MyD88/NF-κB signalling in mice

Lipopolysaccharide (LPS)-induced sepsis-associated acute kidney injury (SA-AKI) is a model of clinical serious care syndrome, with high morbidity and mortality. Tacrolimus (TAC), a novel immunosuppressant that inhibits inflammatory response, plays a pivotal role in kidney diseases. In this study, LPS treated mice and cultured podocytes were used as the models of SA-AKI in vivo and in vitro, respectively. Medium- and high-dose TAC administration significantly attenuated renal function and renal pathological manifestations at 12, 24 and 48 h after LPS treatment in mice. Moreover, the Toll-like receptor 4 (TLR4)/myeloid differential protein-88 (MyD88)/nuclear factor-kappa (NF-κB) signalling pathway was also dramatically inhibited by medium- and high-dose TAC administration at 12, 24 and 48 h of LPS treatment mice. In addition, TAC reversed LPS-induced podocyte cytoskeletal injury and podocyte migratory capability. Our findings indicate that TAC has protective effects against LPS-induced AKI by inhibiting TLR4/MyD88/NF-κB signalling pathway and podocyte dysfunction, providing another potential therapeutic effects for the LPS-induced SA-AKI.

Anesthetics mediated the immunomodulatory effects via regulation of TLR signaling

Anesthetics have been widely used in surgery and found to suppress inflammatory injury and affect the outcomes of the surgery and diseases. In contrast, anesthetics are also found to induce neuronal injury and inflammation. However, the immune-modulation mechanism of anesthetics is still not clear. Recent studies have shown that the immune-modulation of anesthetics is associated with the regulation of toll-like receptor (TLR)-mediated signaling. Moreover, the regulation of anesthetics in TLR signaling is related to modulations of non-coding RNAs (nc RNAs). Consistently, nc RNAs are mainly divided into micro RNAs (miRs) and long non-coding RNAs (lnc RNAs), which have been found to exert regulatory effects on the immune system. In this review, we summarize the immunomodulatory functions of the widely used anesthetic agents, which are associated with regulation of TLR signaling. In addition, we also focus on the roles of nc RNAs induced by anesthetics in regulations of TLR signaling.

Release of HMGB1 in Podocytes Exacerbates Lipopolysaccharide-Induced Acute Kidney Injury

Objective

Acute kidney injury (AKI) usually occurs during sepsis. Inflammation factors, such as high-mobility group box 1 (HMGB1), are dramatically upregulated under septic conditions. In our current work, the functions of HMGB1 in AKI were explored.

Methods

An AKI model was induced by the lipopolysaccharide (LPS) challenge in C57 mice. Podocytes were challenged by LPS for different durations. Subsequently, podocytes transfected with HMGB1 siRNA were exposed to LPS for 24 h. The expressions of supernatant HMGB1 and cellular active caspase-3 were examined by Western blotting analysis. To explore the effect of HMGB1 on tubular epithelial cells (TECs), HK-2 cells were exposed to HMGB1 at various concentrations for 24 h. Epithelial-mesenchymal transition (EMT) of HK-2 cells was evaluated by Western blotting analysis. Mitochondrial division and apoptosis of HK-2 cells were assessed by MitoTracker Red and Western blotting analysis, respectively.

Results

Compared with the sham control group, the expression of HMGB1 was increased in the kidney of AKI mice. Moreover, the expression of supernatant HMGB1 was increased in LPS-challenged podocytes compared with the control group. Knockdown of HMGB1 attenuated LPS-induced podocyte injury. Besides, EMT in TECs was triggered by HMGB1. Mitochondrial damage and apoptosis of HK-2 cells exposed to HMGB1 were markedly elevated compared with the control group.

Conclusions

Collectively, HMGB1 release in podocytes was induced by LPS, subsequently leading to exacerbated AKI.

Downregulation of miR-29b-3p aggravates podocyte injury by targeting HDAC4 in LPS-induced acute kidney injury

Sepsis is a severe organ dysfunction disease, usually accompanied by acute kidney injury (AKI). miR-29b-3p was inhibited in sepsis-induced AKI, while its role in AKI was unclear. Therefore, this study determined the role of miR-29b-3p in sepsis-induced AKI, and investigated its underlying mechanism. In this study, the AKI model was established through injecting with lipopolysaccharides (LPS) intraperitoneally. In LPS challenged mice, serum blood urea nitrogen and creatinine were increased, and renal tissues pathological damage was induced. Besides, miR-29b-3p was declined in LPS-induced AKI mice and podocytes. In addition, HDAC4 was elevated in LPS-treated podocytes. Furthermore, upregulated miR-29b-3p attenuated LPS-induced mice podocyte injury, and HDAC4 was identified as a direct target of miR-29b-3p. Moreover, overexpression of miR-29b-3p attenuated LPS-induced AKI in mice. In conclusion, miR-29b-3p was inhibited in LPS-induced AKI. Downregulation of miR-29b-3p aggravated podocyte injury through targeting HDAC4 in LPS-induced AKI. miR-29b-3p may act as a valuable target for AKI therapy.

miR-129-5p Promotes Osteogenic Differentiation of BMSCs and Bone Regeneration via Repressing Dkk3

Objective

Accumulating evidence indicates that microRNAs (miRNAs) play crucial roles in osteogenic differentiation. However, the associated mechanisms remain elusive. This paper is aimed at exploring the role of miR-129-5p in regulating bone marrow mesenchymal stem cell (BMSC) differentiation and bone regeneration in vivo and in vitro.

Methods

BMSCs were transduced by miR-129-5p mimic, miR-129-5p inhibitor, and negative control lentivirus. The ability of BMSC differentiation to osteoblast was tested by alkaline phosphatase (ALP) and alizarin red staining (ARS). The expression of osteogenic genes (Runx2, Bmp2, and OCN) was examined via quantitative RT-PCR and western blot. A mouse model of calvaria defect was investigated by Micro-CT, immunohistochemistry, and histological examination. The luciferase reporter gene assay was performed to confirm the binding between Dkk3 and miR-129-5p. For the transfection experiments, lipofectamine 3000 was used to transfect pcDNA-Dkk3 into BMSCs to overexpress Dkk3. Coimmunoprecipitation and immunofluorescent localization assay were included for exploring the role of Dkk3 and β-catenin.

Results

miR-129-5p was induced in BMSCs and MSC cell line C3H10T1/2 cells under osteogenic medium. Overexpression of miR-129-5p significantly promoted osteogenic differentiation of BMSCs in vitro. Moreover, BMSCs transduced with miR-129-5p mimic exhibited better bone regeneration compared with BMSCs transduced with control counterpart in vivo. Luciferase and western blot data showed that Dickkopf3 (Dkk3) is a target gene of miR-129-5p and the expression of Dkk3 was inhibited in BMSCs transduced with miR-129-5p mimic but enhanced in BMSCs transduced with miR-129-5p inhibitor. In addition, Dkk3 interacted with β-catenin directly.

Conclusions

miR-129-5p promotes osteogenic differentiation of BMSCs and bone regeneration, and miR-129-5p/Dkk3 axis may be new potential targets for the treatment of bone defect and bone loss.

Circular RNA TLK1 Promotes Sepsis-Associated Acute Kidney Injury by Regulating Inflammation and Oxidative Stress Through miR-106a-5p/HMGB1 Axis

Sepsis is an inflammatory disorder and leads to severe acute kidney injury (AKI). Circular RNAs (circRNAs) have been identified as a critical type of regulatory noncoding RNAs (ncRNAs) that present the important functions in various diseases. In this study, we identified a novel circRNA circTLK1 in the regulation of sepsis-induced AKI. We observed that circTLK1 expression was elevated in the cecal ligation and puncture (CLP) rat model compared with that in the control rats. The urine levels of neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (Kim-1) and the serum levels of creatinine (sCr) and blood urea nitrogen (BUN) were increased by the CLP treatment in the rats but were blocked by the circTLK1 shRNA. The circTLK1 shRNA reduced the CLP-induced kidney injury in the rats. The circTLK1 knockdown repressed oxidation stress, inflammation, and apoptosis in the sepsis-related AKI rat model. Moreover, lipopolysaccharide (LPS) treatment increased the production of TNF-α, IL-1β, and IL-6 in the HK-2 cells, while the circTLK1 shRNA could attenuate the enhancement in the cells. Bax and cleaved caspase-3 expression was upregulated, but Bcl-2 expression was downregulated by the LPS in the HK-2 cells, in which circTLK1 depletion reversed this effect in the cells. The depletion of circTLK1 attenuated the LPS-induced apoptosis in the HK-2 cells. CircTLK1 enhanced HMGB1 expression by sponging miR-106a-5p in the HK-2 cells, and miR-106a-5p and HMGB1 were involved in circTLK1-meidated injury of LPS-treated cells. Therefore, we concluded that circTLK1 contributed to sepsis-associated AKI by regulating inflammation and oxidative stress through the miR-106a-5p/HMGB1 axis. CircTLK1 and miR-106a-5p may be employed as the potential targets for the treatment of AKI.

MicroRNA‑129 plays a protective role in sepsis‑induced acute lung injury through the suppression of pulmonary inflammation via the modulation of the TAK1/NF‑κB pathway

Excessive inflammatory response and apoptosis play key roles in the pathogenic mechanisms of sepsis-induced acute lung injury (ALI); however, the molecular pathways linked to ALI pathogenesis remain unclear. Recently, microRNAs (miRNAs/miRs) have emerged as important regulators of inflammation and apoptosis in sepsis-induced ALI; however, the exact regulatory mechanisms of miRNAs remain poorly understood. In the present study, the gene microarray dataset GSE133733 obtained from the Gene Expression Omnibus database was analyzed and a total of 38 differentially regulated miRNAs were identified, including 17 upregulated miRNAs and 21 downregulated miRNAs, in mice with lipopolysaccharide (LPS)-induced ALI, in comparison to the normal control mice. miR-129 was found to be the most significant miRNA, among the identified miRNAs. The upregulation of miR-129 markedly alleviated LPS-induced lung injury, as indicated by the decrease in lung permeability in and the wet-to-dry lung weight ratio, as well as the improved survival rate of mice with ALI administered miR-129 mimic. Moreover, the upregulation of miR-129 reduced pulmonary inflammation and apoptosis in mice with ALI. Of note, transforming growth factor activated kinase-1 (TAK1), a well-known regulator of the nuclear factor-κB (NF-κB) pathway, was directly targeted by miR-129 in RAW 264.7 cells. More importantly, miR-129 upregulation impeded the LPS-induced activation of the TAK1/NF-κB signaling pathway, as illustrated by the suppression of the nuclear phosphorylated-p65, p-IκB-α and p-IKKβ expression levels. Collectively, the findings of the present study indicate that miR-129 protects mice against sepsis-induced ALI by suppressing pulmonary inflammation and apoptosis through the regulation of the TAK1/NF-κB signaling pathway. This introduces the basis for future research concerning the application of miR-129 and its targets for the treatment of ALI.

Interaction between non-coding RNAs and Toll-like receptors

Toll-like receptors (TLRs) are a large group of pattern recognition receptors which are involved in the regulation of innate immune responses. Based on the interplay between TLRs and adapter molecules, two distinctive signaling cascades, namely the MyD88-dependent and TRIF-dependent pathways have been recognized. TLRs are involved in the development of a wide variety of diseases including cancer and autoimmune disorders. A large body of evidence has shown interaction between two classes of non-coding RNAs, namely microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). These interactions have prominent roles in the pathogenesis of several disorders including infectious disorders, autoimmune conditions and neoplastic disorders. This review aims at description of the interaction between these non-coding RNAs and TLRs.

Reduced expression of MiR-125a-5p aggravates LPS-induced experimental acute kidney injury pathology by targeting TRAF6

AIMS

Patients with acute kidney injury (AKI) have higher mortality, and sepsis is among its main causes. MicroRNAs (miRNAs) are essential for regulating kidney function and could have curative potential. This study explored the possibility to treat AKI with miR-125a-5p and reveal the possible mechanism.

MATERIALS AND METHODS

LPS-induced mouse model and LPS-induced RAW264.7 cell model of AKI were established and treated with miR-125a-5p mimics or inhibitors. Serum creatinine and blood urea were measured to evaluate kidney function. The pathological changes of kidney tissues were detected by H&E and PAS staining technique, and the infiltration of macrophages were observed by immunohistochemistry. RAW264.7 cell viability, TRAF6 and cytokines expressions under LPS stimulation were measured. The role and therapeutic potential of miR-125a-5p were verified in vivo and in vitro after given miR-125a-5p mimics or inhibitors.

KEY FINDINGS

LPS-induced mice had increasing serum creatinine and urea, and evident pathological changes, including severe tubular dilatation and macrophages infiltration. TRAF6 expression in the kidney was significantly higher, while miR-125a-5p expression was suppressed. MiR-125a-5p targeted TRAF6, and its overexpression deactivated NF-κB signaling pathway, reducing downstream TNF-α, IL-1β and IL-6 expressions. MiR-125a-5p mimics rescued LPS-induced kidney damage and suppressed pro-inflammatory cytokines expression through inhibiting TRAF6/NF-κB axis.

SIGNIFICANCE

We highlighted that miR-125a-5p could inhibit LPS-induced acute inflammation in the kidney through targeting TRAF6/NF-κB axis. These results might contribute to the development of molecular therapy in AKI.

MiR-129-5p shuttled by human synovial mesenchymal stem cell-derived exosomes relieves IL-1β induced osteoarthritis via targeting HMGB1

AIMS

To explore the therapeutic effect of miR-129-5p carried by exosomes from Human Synovial Mesenchymal Stem Cell (HS-MSC) on osteoarthritis(OA).

MATERIALS AND METHODS

The levels of miR-129-5p and high mobility group protein -1 (HMGB1) and interleukin-1β (IL-1β) in the joint fluid of OA patients were respectively detected via real-time quantitative reverse transcription-PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). IL-1β was taken to act on chondrocytes for the establishment of OA model in vitro. Ultracentrifugation was conducted to isolate HS-MSC exosomes (HS-MSC-Exo) from the supernatant. Western blot and ELISA were carried out to measure the expression of iNOS, COX2, MMP13, Collagen 2, TLR4, NF-κB, Caspase3, Bcl-2, HMGB1 in chondrocytes. Flow cytometry was conducted to detect the apoptosis of chondrocytes. Besides, bioinformatics was employed to predict the targeted relationship between miR-129-5p and HMGB1, which was further verified via dual luciferase activity experiments.

KEY FINDINGS

The results illustrated that miR-129-5p was decreased in OA patients and IL-1β-induced chondrocytes, while HMGB1 was notably upregulated. HS-MSC-Exo rich in miR-129-5p remarkably declined the inflammatory response and apoptosis of chondrocytes, while HS-MSC-Exo deficient in miR-129-5p increased the IL-1β-mediated inflammatory response and apoptosis of chondrocytes. In terms of mechanism, miR-129-5p targets the 3'UTR end of HMGB1 and inhibits IL-1β-mediated upregulation of HMGB1.

SIGNIFICANCE

In a word, this paper proved that miR-129-5p, existing in HS-MSC-Exo, can suppress the IL-1β-mediated OA by inhibiting HMGB1 release.

microRNA-103a-3p confers protection against lipopolysaccharide-induced sepsis and consequent multiple organ dysfunction syndrome by targeting HMGB1

BACKGROUND

Sepsis and subsequent multiple organ dysfunction syndrome (MODS) have high global incidence and mortality rate, imposing tremendous health burden. microRNAs (miRNAs or miRs) are implicated in the pathogenesis of sepsis and MODS. The aim of this study is to explore the potential mechanisms of miR-103a-3p targeted high mobility group box 1 (HMGB1) involvement in the pathogenesis of sepsis complicated with multiple organ dysfunction syndrome (MODS).

METHODS

A mouse sepsis model was induced by lipopolysaccharide (LPS). Bone marrow-derived macrophages were collected and LPS was used to establish a cellular inflammation model. Targeted binding between miR-103a-3p and HMGB1 was verified by a double luciferase assay and their roles in LPS-induced sepsis were further explored using gain-of-function experiments.

RESULTS

miR-103a-3p was decreased while HMGB1 was increased in sepsis. In LPS-induced mouse sepsis models, the downregulation of HMGB1 was found to result in reductions in NO, TNF-α, IL-1β, IL-6, lung myeloperoxidase activity, pulmonary microvascular albumin leakage, serum alanine aminotransferase, aspartate aminotransferase activity, and lung and liver tissue apoptosis. Additionally, decreased HMGB1 blunted the inflammatory response and increased survival rate of modeled mice. Importantly, HMGB1 was confirmed to a target gene of miR-103a-3p. In cellular inflammation models, miR-103a-3p was found to alleviate LPS-induced sepsis and MODS in vitro by decreasing HMGB1.

CONCLUSIONS

Taken together, our results demonstrated the inhibitory role of miR-103a-3p in sepsis via inhibiting HMGB1 expression.