Direct Target Of miR-34a Research Articles

MiR-27a inhibits the growth and metastasis of multiple myeloma through regulating Th17/Treg balance.

The imbalance between T helper 17 (Th17) and T regulatory (Treg) cells plays a key role in the progression of multiple myeloma (MM). The gene expression profiles of MM were acquired and examined from the Gene Expression Omnibus (GEO) database (GSE72213). Our research involved experimental investigations conducted using the MOPC-MM mouse model. Dysregulation of Treg and Th17 cells was evaluated through flow cytometry, while the levels of inflammatory factors were measured using the enzyme-linked immunosorbent assay. Cell proliferation was gauged using the Cell Counting Kit-8 assay, and cell apoptosis was quantified via flow cytometry. Cell metastasis capabilities were determined by conducting transwell assays. To confirm the relationship between miR-27a and PI3K, a dual-luciferase reporter assay was employed. Finally, proteins associated with the PI3K/AKT/mTOR signaling pathway were assessed using western blotting. MiR-27a exhibited reduced expression levels in MM. Moreover, it exerted control over the equilibrium of Th17 and Treg cells while reducing the expression of inflammatory mediators such as TGF-β1 and IL-10 in an in vivo setting. Elevated miR-27a levels led to the inhibition of cell viability, colony formation capacity, migratory and invasive traits in an in vitro context. The PI3K/AKT/mTOR signaling pathway was identified as a direct target of miR-27a and could reverse the effects induced by miR-27a in MM cells. Notably, PI3K was directly targeted by miR-27a. Our study revealed that miR-27a inhibited MM evolution by regulating the Th17/Treg balance. Inhibition of the PI3K/AKT/mTOR signaling pathway by miR-27a may play a potential mechanistic role.

Abstract We140: Age-Dependent miR-34a and AGTRAP Cross-Modulation: a Novel Mechanism of Vascular Aging

Background: Renin-Angiotensin Aldosterone System (RAAS) activation plays a central role in vascular aging, leading to structural and functional alterations including vascular smooth muscle cell (VSMC) proliferation, migration and secretion of extracellular matrix and inflammatory molecules. The age-associated increase in Angiotensin II (Ang II) expression enhances AT1-receptor activity and determinates a pro-fibrotic and pro-inflammatory phenotype. Further, miR-34a expression is modulated by aging and increases in different tissues, including the mouse aorta, but no direct miR-34a target has been identified in the RAAS pathway that sustains age-dependent increase of pro-inflammatory signaling. Aims: The aim of our study is to evaluate the potential interaction between miR-34a and RAAS signaling in VSMCs. Methods and Results: miR-34a expression exhibited an age-dependent increase in Rhesus Monkey (8- to 26-year-old) and rat central arteries (8- and 30-month-old). In silico analysis indicated that AT1R-associated protein (AGTRAP), a negative modulator of AT1R signaling, is a potential miR-34a target suggesting that the age-dependent increase in miR-34a in the arterial vascular wall may decrease AGTRAP expression in arterial VSMC. Ang II enhanced miR-34a expression in 30-month-old rat and in human aorta SMCs (HASMCs), whereas AGTRAP and Sirtuin-1 (SIRT1) mRNA and protein level decreased. Immunohistochemistry analysis showed a decrease of AGTRAP in 18-month-old miR-34a knock-out mice compared to 2-month-old mice. By luciferase assay, we demonstrated that AGTRAP is a direct miR-34a target. Moreover, AGTRAP and SIRT1 decreased in HASMCs infected with miR-34a-encoding lentivirus and this effect was partially rescued in AGTRAP/miR-34a co-infected cells. Finally, pro-inflammatory genes IL-6, COX-2, MCP-1 and MFG-E8 expression was upregulated in Ang II-treated and miR-34a overexpressing HASMCs, and this effect was abolished in AGTRAP/miR-34a co-transfected cells. Conclusions: Our results show cross-modulation between miR-34a and AGTRAP. MiR-34a targeting AGTRAP increases the expression of pro-inflammatory molecules in VSMCs and represents a novel mechanism that modulates RAAS signaling in vascular aging. Statement: This research was supported in part by the Intramural Research Program of the NIH, National Institute on Aging.

MiR-34a-HK1 signal axis retards bone marrow mesenchymal stem cell senescence via ameliorating glycolytic metabolism

BackgroundMesenchymal stem cells (MSCs) are one of the most widely studied adult stem cells, while MSC replicative senescence occurs with serial expansion in vitro. We determined whether miR-34a can regulate MSC senescence by directly targeting glycolytic key enzymes to influence glycolysis.MethodsDetected the effects of miR-34a on MSC senescence and glycolytic metabolism through gene manipulation. Bioinformatics prediction and luciferase reporter assay were applied to confirm that HK1 is a direct target of miR-34a. The underlying regulatory mechanism of miR-34a targeting HK1 in MSC senescence was further explored by a cellular function recovery experiment.ResultsIn the current study, we revealed that miR-34a over-expression exacerbated senescence-associated characteristics and impaired glycolytic metabolism. Then we identified hexokinase1 (HK1) as a direct target gene of miR-34a. And HK1 replenishment reversed MSC senescence and reinforced glycolysis. In addition, miR-34a-mediated MSC senescence and lower glycolytic levels were evidently rescued following the co-treatment with HK1 over-expression.ConclusionThe miR-34a-HK1 signal axis can alleviate MSC senescence via enhancing glycolytic metabolism, which possibly provides a novel mechanism for MSC senescence and opens up new possibilities for delaying and suppressing the occurrence and development of aging and age-related diseases.

MiR-29a-KLF4 signaling inhibits breast tumor initiation by regulating cancer stem cells

Cancer stem cells (CSCs) are known for their potent ability to drive tumor initiation and recurrence, yet the molecular mechanisms regulating CSCs are still unclear. Our study found a positive correlation between increased levels of miR-29a and better survival rates in early-stage breast cancer patients, but a negative correlation in late-stage patients, suggesting a dual function of miR-29a in regulating breast cancer. Furthermore, miR-29a showed significant downregulation in the ALDH+ breast cancer stem cell population compared to non-stem cancer cells. Overexpression of miR-29a in human breast cancer cells reduced the proportion of CSCs, suppressed their ability to form mammospheres, and inhibited the expression of stemness genes SOX2, KLF4, and hTERT in vitro. Conversely, knockdown of miR-29a in breast cancer cells showed opposite effects. Tumor xenograft experiments revealed that miR-29a overexpression significantly inhibited tumorigenesis initiated by MDA-MB-231 cell transplantation in nude mice. We further demonstrated that Krüppel-like factor 4 (KLF4), a key gene that regulates cell stemness, was a direct target of miR-29a in breast cancer cells. miR-29a suppressed the expression of KLF4 at both mRNA and protein levels. Reintroduction of KLF4 into breast cancer cells rescued the miR-29a-induced CSC suppression phenotype. In summary, our study is the first to demonstrate that miR-29a-KLF4 signaling inhibits breast tumor initiation by regulating CSCs, which provides novel therapeutic targets for preventing breast tumor initiation.

The crucial relationship between miRNA-27 and CSE/H2S, and the mechanism of action of GLP-1 in myocardial hypertrophy.

Cardiac hypertrophy is the most prevalent compensatory heart disease that ultimately leads to spontaneous heart failure. Mounting evidence suggests that microRNAs (miRs) and endogenous hydrogen sulfide (H2S) play a crucial role in the regulation of cardiac hypertrophy. In this study, we aimed to investigate whether inhibition of miR-27a could protect against cardiac hypertrophy by modulating H2S signaling. We established a model of cardiac hypertrophy by obtaining hypertrophic tissue from mice subjected to transverse aortic constriction (TAC) and from cells treated with angiotensin-II. Molecular alterations in the myocardium were quantified using quantitative real time PCR (qRT-PCR), Western blotting, and ELISA. Morphological changes were characterized by hematoxylin and eosin (HE) staining and Masson's trichrome staining. Functional myocardial changes were assessed using echocardiography. Our results demonstrated that miR-27a levels were elevated, while H2S levels were reduced in TAC mice and myocardial hypertrophy. Further luciferase and target scan assays confirmed that cystathionine-γ-lyase (CSE) was a direct target of miR-27a and was negatively regulated by it. Notably, enhancement of H2S expression in the heart was observed in mice injected with recombinant adeno-associated virus vector 9 (rAAV9)-anti-miR-27a and in cells transfected with a miR-27a inhibitor during cardiac hypertrophy. However, this effect was abolished by co-transfection with CSE siRNA and the miR-27a inhibitor. Conversely, injecting rAAV9-miR-27a yielded opposite results. Interestingly, our findings demonstrated that glucagon-like peptide-1 (GLP-1) agonists could mitigate myocardial damage by down-regulating miR-27a and up-regulating CSE. In summary, our study suggests that inhibition of miR-27a holds therapeutic promise for the treatment of cardiac hypertrophy by increasing H2S levels. Furthermore, our findings unveil a novel mechanism of GLP-1 agonists involving the miR-27a/H2S pathway in the management of cardiac hypertrophy.

Col1a1 mediates the focal adhesion pathway affecting hearing in miR-29a mouse model by RNA-seq analysis

Age-related hearing loss (ARHL) is a common neurodegenerative disease. Its molecular mechanisms have not been fully elucidated. In the present study, we obtained differential mRNA expression in the cochlea of 2-month-old miR-29a+/+ mice and miR-29a−/− mice by RNA-seq. Gene ontology (GO) analysis was used to identify molecular functions associated with hearing in miR-29a−/− mice, including being actin binding (GO: 0003779) and immune processes. We focused on the intersection of differential genes, miR-29a target genes and the sensory perception of sound (GO:0007605) genes, with six mRNA at this intersection, and we selected Col1a1 as our target gene. We validated Col1a1 as the direct target of miR-29a by molecular and cellular experiments. Total 6 pathways involved in Col1a1 were identified by through Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. We selected the focal adhesion pathway as our target pathway based. Their expression levels in miR-29a−/− mice were verified by qRT-PCR and Western blot. Compared with miR-29a+/+ mice, the expression levels of Col1a1, Itga4, Itga2, Itgb3, Itgb7, Pik3r3 and Ptk2 were different in miR-29a−/− mice. Immunofluorescence was used to locate genes in the cochlea. Col1a1, Itga4 and Itgb3 were differentially expressed in the basilar membranes and stria vascularis and spiral ganglion neurons compared to miR-29a+/+ mice. Pik3r3 and Ptk2 were differentially expressed in the basilar membranes and stria vascularis, but not at the s spiral ganglion neurons compared to miR-29a+/+ mice.Our results show that when miR-29a is knocked out, the Col1a1 mediates the focal adhesion pathway may affect the hearing of miR-29a−/− mice. These findings may provide a new direction for effective treatment of age-related hearing loss.

MiR 19a promotes proliferation and inhibits apoptosis of placental trophoblasts via PTEN pathway

Purpose: To screen the micro-ribonucleic acids (miRNAs) in the pathological processes of preeclampsia (PE), and to assess their effects on the proliferation and apoptosis of HTR-8/SVneo cells.
 Methods: The miRNAs in PE patients and healthy puerperae were screened out using miRNA microarray assay, and verified through low-throughput quantitative reverse transcription- polymerase chain reaction (qRT-PCR). The effects of expression level of miR-19a on proliferation and cycle of HTR-8/SVneo cells were determined using cell counting kit (CCK)-8 assay and propidium iodide (PI) staining, respectively. The influence of the expression level of miR-19a on apoptosis of HTR-8/SVneo cells was evaluated using Annexin V-fluorescein isothiocyanate (FITC)/PI staining. Subsequently, luciferase reporter gene assay, CCK-8 assay and Annexin V-FITC/PI staining were conducted, respectively.
 Results: Serum miR-19a was significantly decreased in PE patients, and a high level of miR-19a led to increase in the proliferation of HTR-8/SVneo cells. Decreased level of miR-19a arrested HTR-8/SVneo cell cycle at G1 phase, while increase in the miR-19a level repressed the apoptosis of HTR-8/SVneo cells. The PTEN was a direct target of miR-19a, and overexpression of miR-19a promoted the activation of Akt signaling pathway, thereby significantly decreasing the expression levels of downstream phosphorylated p21/p21 (p-p21/p21), p-p27/p27 and p-glycogen synthase kinase-3 beta (GSK3β)/GSK3β. Compared with those in cells transfected with empty vectors, the pro-proliferative and anti-apoptotic effects of miR-19a weakened in HTR-8/SVneo cell lines with overexpressed PTEN.
 Conclusion: MiR-19a targets PTEN in order to activate Akt signaling pathway, thereby promoting proliferation, and inhibiting apoptosis of HTR-8/SVneo cells. This provides new drug targets that can be investigated for future treatment of PE.

Regulation of ERα-dependent breast cancer metastasis by a miR-29a signaling

Malignant breast cancer (BC) remains incurable mainly due to the cancer cell metastasis, which is mostly related to the status of Estrogen receptor alpha (ERα). However, our understanding of the mechanisms through which ERα regulates cancer cell metastasis remains limited. Here we identified a miR-29a-PTEN-AKT axis as a downstream signaling pathway of ERα governing breast cancer progression and metastasis. Two estrogen response element (ERE) half sites were identified in the promoter and enhancer regions of miR-29a, which mediated transcriptional regulation of miR-29a by ERα. Low level of miR-29a showed association with reduced metastasis and better survival in ERα+ luminal subtype of BC. In contrast, high level of miR-29a was detected in ERα- triple negative breast cancer (TNBC) in association with distant metastasis and poor survival. miR-29a overexpression in BC tumors increased the number of circulating tumor cells and promoted lung metastasis in mice. Targeted knockdown of miR-29a in TNBC cells in vitro or administration of a nanotechnology-based anti-miR-29a delivery in TNBC tumor-bearing mice in vivo suppressed cellular invasion, EMT and lung metastasis. PTEN was identified as a direct target of miR-29a, inducing EMT and metastasis via AKT signaling. A small molecular inhibitor of AKT attenuated miR-29a-induced EMT. These findings demonstrate a novel mechanism responsible for ERα-regulated breast cancer metastasis, and reveal the combination of ERα status and miR-29a levels as a new risk indicator in BC.

MiR-133a/CD47 axis is a novel prognostic biomarker to promote triple negative breast cancer progression

Cluster of differentiation 47 (CD47) acts as an anti-engulfment signal on tumor cells, and its overexpression is correlated with poor prognosis of various malignant tumors. However, the role and mechanism of CD47 in tumor cell proliferation, migration and apoptosis remain unclarified. Emerging evidence indicates that microRNAs (miRNAs) are potential regulators to mediate CD47 generation. In this study, we found that CD47 was up-regulated while miR-133a was down-regulated in triple-negative breast cancer (TNBC) in vitro and in vivo. Moreover, we demonstrated for the first time that CD47 was a direct target of miR-133a in TNBC cells, and provided direct evidence of the inverse correlation between miR-133a and CD47 expression in TNBC. Besides, miR-133a functioned as a tumor suppressor to inhibit proliferation and migration, and promote apoptosis of TNBC cells by targeting CD47. Furthermore, overexpression of miR-133a inhibited the tumor growth of TNBC in an in vivo xenograft animal model by targeting CD47. Thus, miR-133a/CD47 axis provides new insight into the mechanism of TNBC progression and could be a promising candidate in the diagnosis and treatment of TNBC.

MiR-34a regulates silent synapse and synaptic plasticity in mature hippocampus.

AMPAR-lacking silent synapses are prevailed and essential for synaptic refinement and synaptic plasticity in developing brains. In mature brain, they are sparse but could be induced under several pathological conditions. How they are regulated molecularly is far from clear. miR-34a is a highly conserved and brain-enriched microRNA with age-dependent upregulated expression profile. Its neuronal function in mature brain remains to be revealed. Here by analyzing synaptic properties of the heterozygous miR-34a knock out mice (34a_ht), we have discovered that mature but not juvenile 34a_ht mice have more silent synapses in the hippocampus accompanied with enhanced synaptic NMDAR but not AMPAR function and increased spine density. As a result, 34a_ht mice display enhanced long-term potentiation (LTP) in the Schaffer collateral synapses and better spatial learning and memory. We further found that Creb1 is a direct target of miR-34a, whose upregulation and activation may mediate the silent synapse increment in 34a_ht mice. Hence, we reveal a novel physiological role of miR-34a in mature brains and provide a molecular mechanism underlying silent synapse regulation.

Hypoxia promotes epithelial-mesenchymal transition in lung cancer cells via regulating the NRF2/miR‑27a/BUB1 pathway.

Lung cancer (LC) is the most common malignancy in the world. It is well that hypoxia is common in lung cancer, which contributes to lung cancer progression and metastasis [1]. miRNA-27a as a repressor factor is a lowly expression within non-small cell lung cancer (NSCLC). However, the molecular mechanism between miR-27a and hypoxia in lung cancer progression remains poorly understood. This study aims to explore hypoxia promotes epithelial-mesenchymal transition in lung cancer cells via regulating the NRF2/miR‑27a/BUB1 pathway. We detect the expression of miR-27a after exposure to hypoxia conditions in lung cancer cells via qPCR. Using MTT assay and colony assay to assess the ability of proliferation in lung cancer cells under hypoxia or transfect miR-27a mimics. The capability of migration and invasion was evaluated by wound healing assay and Boyden-chamber assay. The mRNA and protein expression of EMT markers was respectively detected by qPCR and western blot. We detected NRF2 occupancy at the miR-27a promoter by ChIP-Seq analysis. Meanwhile, the luciferase assay verified BUB1 as a direct target of miR-27a. We found hypoxia promotes lung cancer cell proliferation, migration, invasion, and the epithelial-mesenchymal transition (EMT) process by inhibiting the miR-27a expression. miR-27a mimics significantly reduced the promotion effect of hypoxia on the invasion and proliferation of lung cancer cells. NRF2 as regulating the oxidation/anti-oxidation factor was activated under hypoxia conditions. The activation of NRF2 repressed miR-27a expression. On the contrary, the inhibitory effect of hypoxia on miR-27a was reversed when the NFE2L2 gene was silenced. Ectopic expression of NRF2 inhibited miR-27a expression under normoxia. We further validated BUB1 as a direct target of the miR-27a by luciferase assay. Hypoxia promotes invasion and epithelial-mesenchymal transition of Lung cancer cells by regulating the NRF2/miR-27a/BUB1 axis.

MicroRNA-19a Inhibition Directly and Indirectly Ameliorates Th2 Airway Inflammation in Asthma by Targeting RUNX3.

Disruption of T-cell differentiation is characteristic of airway inflammation in allergic asthma. How miR-19a works in asthma has not been completely elucidated. This study aimed to examine whether microRNA-19a regulates helper T-cell proliferation and to identify the factors involved and the underlying mechanisms. Our results showed that miR-19a levels were upregulated in parallel with a reduction in RUNX3 expression in a house dust mite (HDM)-induced murine model of asthma. A dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay showed that RUNX3 was a direct target of miR-19a. Inhibiting the expression of miR-19a attenuated inflammation and mucus production, induced Th1 cells, suppressed the Th2 inflammatory response, and repressed dendritic cell (DC) maturation by increasing RUNX3 expression in WT asthmatic mice but not RUNX3+/- mice. In vitro experiments revealed that miR-19a inhibition could target RUNX3 to induce Th1 polarization and inhibit Th2 polarization by directly acting on naïve CD4+ T cells or indirectly mediating the maturation and antigen-presenting abilities of DCs. These findings indicate that miR-19a directly and indirectly regulates immunoinflammatory responses in asthma by targeting RUNX3.

MiR-181a Improved Renal Inflammation by Targeting TNF-α in a Diabetic Nephropathy Animal Model

Introduction: Recent studies have elucidated that miR-181a plays a vital role in various inflammation-associated diseases; however, its role in the pathogenesis of diabetic nephropathy (DN) has not been elucidated clearly. Hence, we investigated the involvement of miR-181a in the pathogenesis of DN in patients and animal models. Methods: miR-181a levels were measured in the kidneys of DN patients and a DN mouse model (db/db mice) by RT-PCR. The interaction of miR-181a with the 3′-UTR of potential target transcripts was investigated using luciferase reporter assays. miR-181a-GFP-AAV and miR-181a inhibitor were used to overexpress or downregulate miR-181a in the kidney of db/db mice, respectively. The expression of inflammatory proteins and target genes was measured in the kidneys of the animals. Results: In DN patients and DN mouse models, expression analyses showed a significant decrease in miR-181a levels in the kidney. In addition, a negative linear correlation between miR-181a and proinflammatory gene (IL-1β and TNF-α) levels was observed in the kidneys of DN patients. Overexpression of miR-181a reduced IL-1β and TNF-α expression, whereas suppression of miR-181a worsened these changes, which was attenuated by combined treatment with TNF-α neutralizing antibody in db/db mice. Moreover, luciferase assays revealed that TNF-α is a direct target of miR-181a. Conclusion: Our data emphasized the anti-inflammatory actions of miR-181a by targeting TNF-α in the context of renal inflammation in DN. Hence, we concluded that miR-181a could be a potential therapeutic option for minimizing renal inflammation in DN.

MiR-19a suppresses ferroptosis of colorectal cancer cells by targeting IREB2

ABSTRACT Colorectal cancer (CRC) is the most common malignant tumor occurred in digestive system. However, the prognosis of CRC patients is poor. Therefore, it is urgent to illuminate the mechanism suppressing CRC and explore novel targets or therapies for CRC treatment. MicroRNAs (miRNAs) are a class of non-coding RNAs with a length of 20–23 nucleotides encoded by endogenous genes, which are associated with the development of a variety of cancers, including CRC. Studies have shown that miR-19a is identified as oncogenic miRNA and promotes the proliferation, migration and invasion of CRC cells. However, the relationship between miR-19a and ferroptosis in CRC remains unknown. Here, we reported that iron-responsive element-binding protein 2 (IREB2), as an inducer of ferroptosis, was negatively regulated by miR-19a. IREB2 is a direct target of miR-19a. In addition, ferroptosis was suppressed by miR-19a through inhibiting IREB2. Thus, we proposed a novel mechanism of ferroptosis mediated by miR-19a in CRC cells, which could give rise to a new strategy for the therapy of CRC.

Downregulated miR-18a and miR-92a synergistically suppress non-small cell lung cancer via targeting Sprouty 4

ABSTRACT As a novel noncoding RNA cluster, miR-17-92 cluster include six members: miR-17, miR-18a, miR-19a, miR-19b-1, miR-20a, and miR-92a. Dysregulation of miR-17-92 has been proved to be connected with the advancement of a series of human diseases, but the roles of miR-17-92 cluster in non-small cell lung cancer (NSCLC) have not been absolutely elaborated. Herein, we determined that miR-17-92 cluster were upregulated significantly in NSCLC tissues, and the cell proliferation, migration and cycle progression of NSCLC were also facilitated under the function of miR-17-92 cluster. Sprouty 4 (SPRY4) was a direct target of miR-92a, and its overexpression restrained the exacerbation of NSCLC induced by miR-92a. Furthermore, the tumor xenograft assay showed that miR-92a facilitated tumor growth by inhibiting the expression of SPRY4 and mediating Epithelial-Mesenchymal Transition (EMT) in vivo. Finally, we looked into the synergistic effects of miR-92a and miR-18a on NSCLC, and found that antagomiR-18a treatment arrested the tumor growth rate of xenografted mice markedly.

Hyperoxia Induced Bronchopulmonary Dysplasia-Like Inflammation via miR34a-TNIP2-IL-1β Pathway.

Lung injury induced by oxygen is a key contributor to the pathogenesis of preterm infant bronchopulmonary dysplasia (BPD). To date, there are comprehensive therapeutic strategy for this disease, but the underlying mechanism is still in progress. By using lentivirus, we constructed microRNA34a (miR34a)-overexpressing or knockdown A549 cell lines, and exposure to hyperoxia to mimic oxygen induce lung injury. In this study, we investigated 4 proinflammatory cytokines, interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), angiopoietin-1 (Ang-1), and Cyclooxygenase-2 (COX-2) in the secreted sputum of infants who received mechanical ventilation, and found that IL-1β was substantially elevated in the first week after oxygen therapy and with no significant decrease until the fourth week, while TNF-α, Ang-1, and COX-2 were increased in the first week but decreased quickly in the following weeks. In addition, in vitro assay revealed that hyperoxia significantly increased the expression of miR-34a, which positively regulated the proinflammatory cytokine IL-1β in a time- and concentration-dependent manner in A549 cells. Overexpressing or knockdown miR34 would exacerbate or inhibit production of IL-1β and its upstream NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome signaling pathway. Mechanically, it’s found that TNFAIP3 interacting protein 2 (TNIP2), an inhibitor of nuclear factor κB (NF-κB), is a direct target of miR34a, negatively regulated activation of NLRP3 inflammasome and the production of IL-1β. Overexpressing TNIP2 ameliorated hyperoxia-induced production of IL-1β and cell apoptosis. Our findings suggest that TNIP2 may be a potential clinical marker in the diagnosis of BPD.

MicroRNA-34a Promotes Ischemia-Induced Cardiomyocytes Apoptosis through Targeting Notch1.

Myocardial apoptosis occurs during myocardial ischemia. This study aimed to determine the effect of microRNA-34a (miR-34a) in ischemia-induced myocardial apoptosis. Mainly, SD rats were subjected to myocardial ischemia by ligaturing the left anterior descending branch of coronary artery. After rats had myocardial infarction, HE staining and TUNEL staining confirmed a significant increase in apoptosis. The expression of miR-34a was noticeably upregulated, while the expression of Notch1 was downregulated. An increase in caspase-3 and a decrease in Bcl-2/Bax ratio were observed in myocardium. Similar results were observed in the in vitro model of cardiomyocyte ischemia and anoxia of this study. When rat cardiomyocytes were administered with serum starvation and microaerophilic system, apoptosis-related proteins were significantly increased. However, transfecting the miR-34a inhibitor into the cardiomyocyte before the serum starvation and hypoxia treatment could increase the ratio of Bcl-2/Bax and downregulate the expression of caspase-3, as well as prevent cardiomyocytes from apoptosis. As opposed to the abovementioned points, the upregulation of miR-34a expression by transfecting miR-34a mimics induced Notch1 reduce and apoptosis-related proteins increase apparently, while upregulation of Notch1 could stimulate apoptosis attributed to miR-34a. Mechanistically, we demonstrated that Notch1 is a direct target of miR-34a. In conclusion, our current results suggested that miR-34a significantly stimulates ischemia-induced cardiomyocytes apoptosis by targeting Notch1.

MiR-30a-5p Alters Epidermal Terminal Differentiation during Aging by Regulating BNIP3L/NIX-Dependent Mitophagy

Chronological aging is characterized by an alteration in the genes’ regulatory network. In human skin, epidermal keratinocytes fail to differentiate properly with aging, leading to the weakening of the epidermal function. MiR-30a is particularly overexpressed with epidermal aging, but the downstream molecular mechanisms are still uncovered. The aim of this study was to decipher the effects of miR-30a overexpression in the human epidermis, with a focus on keratinocyte differentiation. We formally identified the mitophagy receptor BNIP3L as a direct target of miR-30a. Using a 3D organotypic model of reconstructed human epidermis overexpressing miR-30a, we observed a strong reduction in BNIP3L expression in the granular layer. In human epidermal sections of skin biopsies from donors of different ages, we observed a similar pattern of BNIP3L decreasing with aging. Moreover, human primary keratinocytes undergoing differentiation in vitro also showed a decreased expression of BNIP3L with age, together with a retention of mitochondria. Moreover, aging is associated with altered mitochondrial metabolism in primary keratinocytes, including decreased ATP-linked respiration. Thus, miR-30a is a negative regulator of programmed mitophagy during keratinocytes terminal differentiation, impairing epidermal homeostasis with aging.

MiR-146a Inhibited Pancreatic Cancer Cell Proliferation by Targeting SOX7.

MicroRNAs (miRNAs) act as a kind of small and noncoding RNA, which have been implicated in the regulation of various pathobiological processes in cancer, including progression in pancreatic cancer and in other human cancers. Previous reports demonstrate that pancreatic cancer has been reported as one of the leading causes of cancer-related death, and some factors including oncogenic genes and environments are involved in tumorigenesis. In our study, we found microRNA-146a (miR-146a) was evidently downregulated in pancreatic cancer tissues and cells. Overexpression of miR-146a obviously reduced cell proliferation and tumorigenesis in vitro, as determined by MTT analysis, colony formation analysis, EdU analysis, and cell cycle experiments. Here, we found tumor suppressor sex-determining region Y-box 7 (SOX7) was the direct target of miR-146a. Overexpression of miR-146a decidedly inhibited SOX7 expression, which promotes cell proliferation and tumorigenesis. Knockdown of miR-146a increased SOX7 expression. Depression of miR-146a and SOX7 promoted cell proliferation and tumorigenesis in vitro, confirming miR-146a regulated pancreatic cancer cell proliferation by inhibiting SOX7. In summary, we found miR-146a reduced the cell proliferation of pancreatic cancer through targeting SOX7. In the present study, we demonstrated the function of miR-146a in pancreatic cancer and might provide a new target in the treatment of pancreatic cancer.

MicroRNA-30a Targets Notch1 to Alleviate Podocyte Injury in Lupus Nephritis

ABSTRACT The microRNA miR-30a has been reported to mitigate podocyte damage and resist injurious factors in lupus nephritis (LN), but the precise molecular mechanisms underlying these effects remain elusive. We hypothesized that miR-30a can ameliorate podocyte injury by downregulating the Notch1 signaling pathway and investigated the role of miR-30a in the pathogenesis of podocyte-treated with Immunoglobulin G from patients with LN (IgG-LN). The study enrolled 30 patients from new-onset systemic lupus erythematosus and 28 healthy individuals, then evaluated the levels of their serum miR-30a using RT-qPCR. Additionally, MPC5 cells were transfected with NICD-vector to overexpress Notch1, then with miR-30a mimics or inhibitors to determine miR-30a effects on Notch1. Analysis of function and regulatory mechanisms were performed with RT-qPCR, Western blotting, and CCK8 assays. Furthermore, we verified the candidate sequence targeted by miR-30a using a luciferase reporter gene assay. We observed a significant decrease in the serum miR-30a levels in patients with LN. Also, in IgG-LN-treated podocytes, miR-30a decreased and Notch1 expression was elevated. Bioinformatic analysis and transfection experiments revealed that Notch1 is a direct target of miR-30a. Further supporting this finding, miR-30a upregulation appeared to alleviate IgG-LN-treated podocyte injury, and Notch1 overexpression reversed this effect. To conclude, miR-30a can ameliorate podocyte injury via suppression of the Notch1 signaling pathway.