Hsa_circ_0008360 promotes high glucose-induced damage in HK-2 cells via miR-346/WNT2B axis.

BACKGROUND: Diabetic nephropathy (DN) is a leading cause of end-stage renal disease worldwide. Recent researches have shown that circular RNAs (circRNAs) could affect the progress of DN, but the mechanism is still indistinct. In this work, we explored the roles of hsa_circ_0008360 in DN. METHODS: The levels of hsa_circ_0008360, microRNA-346 (miR-346) and Winglesstype family member 2B (WNT2B) were indicated by quantitative real-time polymerase chain reaction (qRT-PCR) in DN tissues and HK2 cells. Meanwhile, the protein level of WNT2B was quantified by Western blot analysis. Besides, the function of cells was examined by Cell Counting Kit-8 (CCK8) assay, flow cytometry assay, western blot, and ELISA kit. Furthermore, the interplay between miR-346 and hsa_circ_0008360 or WNT2B was detected by dual-luciferase reporter assay. RESULTS: The levels of hsa_circ_0008360 and WNT2B were increased, and the miR-346 level was decreased in the serum of DN patients and HG-treated HK2 cells. For functional analysis, hsa_circ_0008360 deficiency promoted cell viability, inhibits cell apoptosis, inflammatory response, and the synthesis of related fibrotic proteins in HG-treated HK2 cells. Moreover, overexpression of miR-346 induced the proliferation and inhibit apoptosis of HG-induced HK2 cells by inhibiting WNT2B expression. In mechanism, hsa_circ_0008360 acted as a miR-346 sponge to regulate the level of WNT2B. CONCLUSION: Hsa_circ_0008360 can regulate miR-346/WNT2B axis in HG-induced HK2 cells, providing an underlying targeted therapy for DN patients.

Alisol A inhibits the circ_0001831/miR-346/LIN28B pathway to ameliorate high glucose-induced injury of human renal mesangial cells.

BACKGROUND: Alisol A can ameliorate glucose metabolism disorders, however, there is no data regarding its role in diabetic nephropathy (DN). The present work evaluates the role of Alisol A in DN and the underlying mechanism. METHODS: RNA expression of circ_0001831, miR-346, and lin-28 homolog B (LIN28B) was detected by qRT-PCR. Cell viability and proliferation were investigated by MTT assay and EdU assay, respectively. The inflammatory cytokines were examined by ELISAs. Oxidative stress was evaluated by the commercial kits. Protein expression was detected by western blotting. The interactions among circ_0001831, miR-346, and LIN28B were identified by dual-luciferase reporter assay and RIP assay. DN mouse model assay was used to analyse the effect of Alisol A on renal injury of diabetic mice. RESULTS: HG treatment promoted HRMC proliferation, fibrosis, inflammation, and oxidative stress; however, these effects were reversed after Alisol A treatment. Alisol A treatment ameliorated STZ-induced renal injury of diabetic mice. Additionally, circ_0001831 or LIN28B overexpression or miR-346 downregulation relieved Alisol A-induced effects under HG conditions. Mechanistically, circ_0001831 acted as a miR-346 sponge, and LIN28B was identified as a target gene of miR-346. Further, the regulation of circ_0001831 in HG-induced HRMC dysfunction involved LIN28B. CONCLUSION: Alisol A ameliorated HG-induced HRMC fibrosis, inflammation, and oxidative stress and STZ-induced renal injury of diabetic mice by regulating the circ_0001831/miR-346/LIN28B pathway.

LncRNA-412.25 activates the LIF/STAT3 signaling pathway in ovarian granulosa cells of Hu sheep by sponging miR-346.

Although long non-coding RNAs (lncRNAs) are reported to regulate follicular development and reproductive disease pathogenesis, the underlying mechanisms have not been elucidated. In this study, lncRNA expression profiling of different-sized healthy follicles from Hu sheep with different prolificacy revealed 50 613 lncRNAs. Numerous lncRNAs were differentially expressed among different comparison groups. This study characterized one novel transcript, lncRNA-412.25 (from healthy follicles with a diameter of >5 mm), which was predominantly expressed in the high prolificacy group and localized to the cytoplasm of granulosa cells (GCs). LncRNA-412.25 knockdown promoted and inhibited Hu sheep GC apoptosis and proliferation, respectively. Interestingly, lncRNA-412.25 could directly bind to miR-346, which can target the gene of leukemia inhibitory factor (LIF). Knockdown of lncRNA-412.25 promoted GC apoptosis by downregulating LIF expression, where this effect was attenuated by miR-346. Moreover, the miR-346 inhibitor mitigated the lncRNA-412.25 knockdown-induced downregulation of phosphorylated protein of signal transducer and activator of transcription 3 (STAT3), which was validated using immunofluorescence analysis. Our results demonstrated that lncRNA-412.25 regulates GC proliferation and apoptosis in Hu sheep by binding to miR-346 and then activating the LIF/STAT3 pathway. These findings provide novel insights into the mechanisms underlying prolificacy in sheep.

LncRNA NR_003508 Suppresses Mycobacterium tuberculosis-Induced Programmed Necrosis via Sponging miR-346-3p to Regulate RIPK1.

Emerging evidence suggests that long non-coding RNAs (LncRNAs) are involved in Mtb-induced programmed necrosis. Among these LncRNAs, LncRNA NR_003508 is associated with LPS-induced acute respiratory distress syndrome. However, whether LncRNA NR_003508 contributes to Mtb-induced programmed necrosis remains undocumented. Firstly, the expression of LncRNA NR_003508 was determined using RT-qPCR and FISH. The protein expression of RIPK1, p-RIPK1, RIPK3, p-RIPK3, MLKL, and p-MLKL was measured by Western blot in RAW264.7 and mouse lung tissues. Furthermore, luciferase reporter assays and bioinformatics were used to predict specific miRNA (miR-346-3p) and mRNA (RIPK1) regulated by LncRNA NR_003508. In addition, RT-qPCR was used to detect the RIPK1 expression in TB patients and healthy peripheral blood. The flow cytometry assay was performed to detect cell necrosis rates. Here we show that BCG infection-induced cell necrosis and increased LncRNA NR_003508 expression. si-NR_003508 inhibited BCG/H37Rv-induced programmed necrosis in vitro or in vivo. Functionally, LncRNA NR_003508 has been verified as a ceRNA for absorbing miR-346-3p, which targets RIPK1. Moreover, RIPK1 expression was elevated in the peripheral blood of TB patients compared with healthy people. Knockdown of LncRNA NR_003508 or miR-346-3p overexpression suppresses cell necrosis rate and ROS accumulation in RAW264.7 cells. In conclusion, LncRNA NR_003508 functions as a positive regulator of Mtb-induced programmed necrosis via sponging miR-346-3p to regulate RIPK1. Our findings may provide a promising therapeutic target for tuberculosis.

The host micro-RNA cfa-miR-346 is induced in canine leishmaniasis.

BACKGROUND: Leishmaniases are a group of anthropo-zoonotic parasitic diseases caused by a protozoan of the Leishmania genus, affecting both humans and other vertebrates, including dogs. L. infantum is responsible for the visceral and occasionally cutaneous form of the disease in humans and canine leishmaniasis. Previously, we have shown that L. infantum induces a mild but significant increase in endoplasmic reticulum (ER) stress expression markers to promote parasites survival in human and murine infected macrophages. Moreover, we demonstrated that the miRNA hsa-miR-346, induced by the UPR-activated transcription factor sXBP1, was significantly upregulated in human macrophages infected with different L. infantum strains. However, the ER stress response in infected dogs, which represent an important reservoir for Leishmania parasite, was described once recently, whereas the miR-346 expression was not reported before. Therefore, this study aimed to investigate these pathways in the canine macrophage-like cell line DH82 infected by Leishmania spp. and to evaluate the presence of cfa-miR-346 in plasma of non-infected and infected dogs.  The DH82 cells were infected with L. infantum and L. braziliensis parasites and the expression of cfa-mir-346 and several ER stress markers was evaluated by quantitative PCR (qPCR) at different time points. Furthermore, the cfa-miR-346 was monitored in plasma collected from non-infected dogs (n = 11) and dogs naturally infected by L. infantum (n = 18). RESULTS: The results in DH82 cells showed that cfa-mir-346 was induced at both 24 h and 48 h post-infection with all Leishmania strains but not with tunicamycin, accounting for a mechanism of induction independent from sXBP1, unlike what was previously observed in human cell lines. Moreover, the cfa-miR-346 expression analysis on plasma revealed a significant increase in infected dogs compared to non-infected dogs. CONCLUSIONS: Here for the first time, we report the upregulation of cfa-miR-346 induced by Leishmania infection in canine macrophage-like cells and plasma samples of naturally infected dogs. According to our results, the cfa-miR-346 appears to be linked to infection, and understanding its role and identifying its target genes could contribute to elucidate the mechanisms underlying the host-pathogen interaction in leishmaniasis.

Hsa_circ_0006404 and hsa_circ_0000735 Regulated Ovarian Cancer Response to Docetaxel Treatment via Regulating p-GP Expression.

Several microRNAs (miRNAs) and circular RNAs (circRNAs) were reported to be involved in the Docetaxel (DTX) chemoresistance of cancer treatment, but the underlying mechanisms remain to be explored. In this study, we established cellular and animal models respectively to study the effect and underlying molecular mechanisms of the dysregulation of circRNA_0006404 and circRNA_0000735 in tumor response to DTX treatment. Quantitative real-time PCR was performed to measure the expression of circRNA_0006404, miR-346, circRNA_0000735, miR-526b, Dickkopf-related protein 3 (DKK3), and Dickkopf-related protein 4 (DKK4) mRNA. The expression of circRNA_0006404 and circRNA_0000735 was remarkably suppressed and activated in DTX-treated SKOV3-R cell lines, respectively. As revealed by luciferase assays, circRNA_0006404 and circRNA_0000735 was found to be respectively targeted by miR-346 and miR-526b, while DKK3 and DKK4 were respectively targeted by miR-346 and miR-526b. Moreover, the expression of DKK3 and DKK4, which were targets of miR-346 and miR-526b, respectively, was significantly altered along with the expression of p-GP. Furthermore, circ_0006404 shRNA and circRNA_0000735 shRNA showed remarkable efficiency in stimulating the expression of circRNA_0006404, miR-346, DKK3, circRNA_0000735, miR-526b, DKK4, and p-GP in cellular and animal models. Accordingly, the cell apoptosis and proliferation were apparently changed by circ_0006404 shRNA and circRNA_0000735 shRNA in both cellular and animal models. In summary, our study found the involvement of the circRNA_0006404/miR-346/DKK3/p-GP and circRNA_0000735/miR-546b/DKK4/p-GP axis in the tumor response to DTX. Both the up-regulation of circRNA_0006404 and down-regulation of circRNA_0000735 could inhibit the expression of p-GP in vivo and ex vivo, leading to the suppressed tumor response to DTX treatment.

Tumor suppressor LHX6 upregulation contributes to the inhibitory effect of miR-346 knockdown on colorectal cancer cell growth.

Colorectal cancer (CRC) is one of the prevalent types of human malignancies and ranks as the second leading cause of cancer-associated death worldwide. Dysregulated miRNAs have been promulgated as oncogenes or tumor-suppressive genes participating in the initiation and progression of CRC. A recent study reported that miR-346 was highly expressed in CRC patients. However, the biological role and underlying mechanism of miR-346 in CRC remain elusive. qRT-PCR and western blot assays were employed to detect miR-346 and LIM homeobox domain 6 (LHX6) expression in CRC cells. Cell proliferation was evaluated by CCK-8 and BrdU assays. Apoptosis was evaluated by TUNEL assay. The interaction between miR-346 and LHX6 was assessed by luciferase reporter assay. Results showed that miR-346 expression was increased and LHX6 expression was reduced in CRC cells. miR-346 knockdown and LHX6 overexpression inhibited proliferation and promoted apoptosis of CRC cells. Additionally, we found that miR-346 negatively regulated LHX6 expression in CRC cells by directly targeting LHX6. LHX6 knockdown partially attenuated anti-miR-346-induced proliferation reduction and apoptosis promotion in CRC cells. Furthermore, miR-346 knockdown inhibited the protein kinase B (Akt)/mechanistic target of rapamycin (mTOR) pathway in CRC cells by targeting LHX6. The present study indicated that miR-346 knockdown repressed cell growth in CRC cells by upregulating LHX6, and this was associated with inactivation of the Akt/mTOR pathway.

CircHACE1 functions as a competitive endogenous RNA to curb differentiated thyroid cancer progression by upregulating Tfcp2L1 through adsorbing miR-346.

Circular RNAs (circRNAs) are correlated with the occurrence and progression of differentiated thyroid cancer (THCA). However, the regulatory mechanism of circRNAs in differentiated THCA is unclear. In the present study, we analyzed the circRNA microarray dataset (GSE93522) of thyroid tumors and discovered that circRNA HACE1 (circHACE1) was downregulated in differentiated THCA. We detected circHACE1 expression by quantitative real-time polymerase chain reaction (qRT-PCR). Gain-of-function experiments were performed to analyze the biological function of circHACE1 in differentiated THCA cells in vitro. The regulatory mechanism of circHACE1 in differentiated THCA was explored through bioinformatics analysis, dual-luciferase reporter, RIP (RNA immunoprecipitation), and/or RNA pull-down assays. The biological function of circHACE1 in THCA was confirmed by xenograft assay. We verified that circHACE1 was downregulated in differentiated THCA. Also, differentiated THCA patients with low circHACE1 expression were associated with TNM grade, lymphoid node metastasis, tumor size, and poor prognosis. CircHACE1 overexpression decreased xenograft tumor growth in vivo and induced cell cycle arrest, apoptosis, impeded proliferation, migration, and invasion in differentiated THCA cells in vitro. CircHACE1 could function as a microRNA (miR)-346 sponge and regulated Tfcp2L1 (transcription factor CP2 like 1) expression. MiR-346 overexpression offset circHACE1 elevation-mediated effects on malignant behaviors of differentiated THCA cells. Furthermore, Tfcp2L1 silencing counteracted the suppressive impact of miR-346 inhibitor on the malignancy of differentiated THCA cells. In conclusion, circHACE1 adsorbed miR-346 and elevated Tfcp2L1 expression, thus curbing cell malignancy in differentiated THCA, manifesting that circHACE1 might be a target for differentiated THCA treatment.

Hsa_circ_0026416 promotes proliferation and migration in colorectal cancer via miR-346/NFIB axis.

BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers worldwide. Circular RNAs (circRNAs), a novel class of non-coding RNAs, have been confirmed to be key regulators of many diseases. With many scholars devoted to studying the biological function and mechanism of circRNAs, their mysterious veil is gradually being revealed. In our research, we explored a new circRNA, hsa_circ_0026416, which was identified as upregulated in CRC with the largest fold change (logFC = 3.70) of the evaluated circRNAs via analysing expression profiling data by high throughput sequencing of members of the GEO dataset (GSE77661) to explore the molecular mechanisms of CRC. METHODS: qRT-PCR and western blot analysis were utilized to assess the expression of hsa_circ_0026416, miR-346 and Nuclear Factor I/B (NFIB). CCK-8 and transwell assays were utilized to examine cell proliferation, migration and invasion in vitro, respectively. A luciferase reporter assay was used to verify the combination of hsa_circ_0026416, miR-346 and NFIB. A nude mouse xenograft model was also utilized to determine the role of hsa_circ_0026416 in CRC cell growth in vivo. RESULTS: Hsa_circ_0026416 was markedly upregulated in CRC patient tissues and plasma and was a poor prognosis in CRC patients. In addition, the area under the curve (AUC) of hsa_circ_0026416 (0.767) was greater than the AUC of CEA (0.670), CA19-9 (0.592) and CA72-4 (0.575). Functionally, hsa_circ_0026416 promotes cell proliferation, migration and invasion both in vitro and in vivo. Mechanistically, hsa_circ_0026416 may function as a ceRNA via competitively absorbing miR-346 to upregulate the expression of NFIB. CONCLUSIONS: In summary, our findings demonstrate that hsa_circ_0026416 is an oncogene in CRC. Hsa_circ_0026416 promotes the progression of CRC via the miR-346/NFIB axis and may represent a potential biomarker for diagnosis and therapy in CRC.

LncRNA NBAT1 suppresses cell proliferation and migration via miR-346/GSK-3ß axis in renal carcinoma.

Long non-coding RNA (LncRNA) neuroblastoma associated transcript 1 (NBAT1) was demonstrated to be significantly downregulated in renal carcinoma (RCC) cells. However, the function and mechanism of NBAT1 in RCC is poorly understood. The expression of NBAT1 and glycogen synthase kinase-3ß (GSK-3ß)-mediated Wnt/ß-catenin-related proteins were measured by quantitative real-time PCR (qRT-PCR) and western blotting in RCC cell lines. Cell viability, migration, and invasion were estimated by CCK-8 and Transwell assay. The association of miR-346 with GSK-3ß expression was verified using luciferase assay. NBAT1 was significantly downregulated in RCC cells, and inhibited RCC cell proliferation, migration, and invasion. Furthermore, NBAT1 negatively regulated miR-346 expression. In addition, miR-346 overexpression and the knockdown of GSK-3ß, a direct target of miR-346 could overturn the inhibitory effect of NBAT1 on Wnt/ß-catenin signaling and cell proliferation, migration, and invasion. NBAT1 functioned as an endogenous sponge by competing for miR-346 binding to GSK-3ß and therefore alleviated RCC cells.

MicroRNA-346 inhibits the growth of glioma by directly targeting NFIB.

BACKGROUND: Glioma is considered one of the most common tumors and has a poor prognosis. Recently, microRNAs (miRNAs) have been reported to be strongly linked to various human tumors including glioma. In this study, we investigated a new anticancer miRNA, miR-346, to determine the effects and mechanism of miR-346 and its downstream target gene NFIB on tumors. METHODS: Lentivirus transfection, real-time PCR, western blotting, immunohistochemistry, cell proliferation assays, and mouse experiments were used to examine the relationship between miR-346 and its regulation of NFIB in glioma cells. RESULTS: The expression of miR-346 was downregulated in glioma cells. Overexpression of miR-346 arrested the cell cycle of glioma cells and inhibited their proliferation in vitro and in vivo. NFIB was a direct target of miR-346, whose expression was reduced by the miRNA. Overexpression of NFIB reversed all tested functions of miR-346. CONCLUSION: miR-346 inhibited the growth of glioma cells by targeting NFIB and may be a new prognostic and diagnostic biomarker for glioma.

Hsa-miR-346 plays a role in the development of sepsis by downregulating SMAD3 expression and is negatively regulated by lncRNA MALAT1.

Sepsis is a common complication in infection, trauma, and surgery. Severe sepsis has been identified as the leading cause of death in patients suffering from noncardiovascular ailments in intensive care units. In the current study, we used lipopolysaccharide (LPS) to stimulate the mouse macrophage cell line RAW264.7, and investigated the effects of the lncRNA MALAT1/hsa-miR-346/SMAD3 regulatory network on the progression of sepsis. We showed that MALAT1 inhibited RAW264.7 cell proliferation, while hsa-miR-346 promoted its proliferation. In this RAW264.7 cell model, MALAT1 inhibited hsa-miR-346 expression, and upregulated SMAD3 protein expression. The SMAD3 protein expression in RAW264.7 cells was significantly downregulated upon the overexpression of hsa-miR-346. These results suggest that the MALAT1/hsa-miR-346/SMAD3 regulatory network plays a key role in the development of sepsis, and may serve as a target for the treatment of sepsis.

LncRNA DGCR5 represses the development of hepatocellular carcinoma by targeting the miR-346/KLF14 axis.

Long non-coding RNAs (lncRNAs) are a class of regulatory noncoding RNAs. Emerging evidence highlights the critical roles of lncRNAs in the progression of hepatocellular carcinoma (HCC). Although many lncRNAs have been identified in the development of HCC, the association between DiGeorge syndrome critical region gene 5 (DGCR5) and HCC remains unclear. In the current study, we focused on the biological role of DGCR5 in HCC. We observed that DGCR5 was decreased in HCC cells, including SMCC7721, Hep3B, HepG2, MHCC-97L, MHCC-97H, and SNU449 hepatocellular carcinoma cells, compared with the normal human liver cell line THLE-3 normal human liver cells. In addition, DGCR5 overexpression could repress HCC cell growth, migration, and invasion considerably. Increasing studies have indicated the interactions between lncRNAs and microRNAs. MicroRNAs are endogenous small noncoding RNAs and they can play important roles in tumorigenesis. MicroRNA 346 (miR-346) has been demonstrated in various human cancer types, including HCC. MiR-346 was found to be increased in HCC cells and DGCR5 can act as a sponge of miR-346 to modulate the progression of HCC. The binding correlation between DGCR5 and miR-346 was validated in our research. Subsequently, Krüppel-like factor 14 (KLF14) was predicted as a downstream target of miR-346 and miR-346 can induce the development of HCC by inhibiting KLF14. Finally, we proved that DGCR5 can rescue the inhibited levels of KLF14 repressed by miR-346 mimics in MHCC-97H and Hep3B cells. Taken together, it was indicated in our study that DGCR5 can restrain the progression of HCC through sponging miR-346 and modulating KLF14 in vitro.

Differential miR-346 and miR-582-3p Expression in Association with Selected Maternal and Fetal Complications.

Several miRNAs are expressed in human gestational tissue, and some have been shown to be associated with placental dysfunction and complicated pregnancy outcomes. To investigate the roles of miR-346 and miR-582-3p in adverse obstetric events, we analyzed these 2 miRNAs in three samples (maternal blood, umbilical cord blood and placenta) obtained from pregnant women in four groups, including healthy control (n = 60), preeclampsia (n = 31), preterm delivery (n = 29) and small for gestational age (n = 19) patients. The expression levels of miR-346 and miR-582-3p in all included adverse obstetric outcome groups were significantly higher in the maternal plasma samples but lower in the placenta samples (all p value < 0.05). In addition, the miR-346 expression levels in fetal cord blood were also significantly lower in all of the included adverse obstetric outcome groups (all p < 0.05). Multivariate analysis of the three specimens after adjusting for maternal age and gestational age at delivery gave the same results. In conclusion, aberrant miR-346 and miR-582-3p expression level in pregnancy was associated with multiple maternal and fetal complications. Their differential expression in maternal blood, umbilical cord blood and placenta could be potential biomarkers or therapeutic targets for adverse obstetric outcomes.

miR-346 Up-regulates Argonaute 2 (AGO2) Protein Expression to Augment the Activity of Other MicroRNAs (miRNAs) and Contributes to Cervical Cancer Cell Malignancy.

MicroRNAs (miRNAs) are a class of post-transcriptional regulators of gene expression, and AGO2 is essential for miRNA activity. In this study, we focused on the regulation of AGO2 by miR-346 and the consequences in cervical cancer cells. miR-346 enhanced the expression of AGO2, resulting in the increased activity of other miRNAs and contributing to the malignancy of HeLa cells. GRSF1 participated in the regulation of AGO2 by miR-346, and the middle sequence of miR-346 was vital for the synergy effect of miR-346 and GRSF1. We determined that miR-346 promoted the migration and invasion of HeLa cells. In summary, we are the first to report that AGO2 is regulated positively by miRNA and that GRSF1 participates in the miRNA pathway.

MicroRNA-346 functions as an oncogene in cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is an epidermal keratinocyte-derived skin tumor, which is the second most common skin cancer in the general population. Recently, studies showed that microRNAs (miRNAs) played an important role in the development of cancer. In our study, we showed that the expression of SRCIN1 was lower in cSCC tissues than in the matched normal tissues. Moreover, there was significant inversed correlation between miR-346 and SRCIN1 in cSCC tissues. The luciferase reporter assay data showed that miR-346 can target the SRCIN1 message via the 3'-untranslated region (UTR) of SRCIN1. Overexpression of miR-346 inhibited the messenger RNA (mRNA) and protein expression of SRCIN1 in the A431 cells. In addition, ectopic expression of miR-346 promoted the A431 cell proliferation and migration. Meanwhile, SRCIN1 overexpression inhibited the A431 cell proliferation and migration. Rescue experiment has showed that SRCIN1 overexpression reduced the miR-346-induced A431 cell proliferation and migration. Herein, this study may provide miR-346 as a new therapeutic target for cSCC.

miR-193b-3p and miR-346 Exert Antihypertensive Effects in the Rostral Ventrolateral Medulla.

BACKGROUND: Rostral ventrolateral medulla (RVLM) neuron hyperactivity raises sympathetic outflow, causing hypertension. MicroRNAs (miRNAs) contribute to diverse biological processes, but their influence on RVLM neuronal excitability and blood pressure (BP) remains widely unexplored. METHODS AND RESULTS: The RVLM miRNA profiles in spontaneously hypertensive rats were unveiled using RNA sequencing. Potential effects of these miRNAs in reducing neuronal excitability and BP and underlying mechanisms were investigated through various experiments. Six hundred thirty-seven miRNAs were identified, and reduced levels of miR-193b-3p and miR-346 were observed in the RVLM of spontaneously hypertensive rats. Increased miR-193b-3p and miR-346 expression in RVLM lowered neuronal excitability, sympathetic outflow, and BP in spontaneously hypertensive rats. In contrast, suppressing miR-193b-3p and miR-346 expression in RVLM increased neuronal excitability, sympathetic outflow, and BP in Wistar Kyoto and Sprague-Dawley rats. Cdc42 guanine nucleotide exchange factor (Arhgef9) was recognized as a target of miR-193b-3p. Overexpressing miR-193b-3p caused an evident decrease in Arhgef9 expression, resulting in the inhibition of neuronal apoptosis. By contrast, its downregulation produced the opposite effects. Importantly, the decrease in neuronal excitability, sympathetic outflow, and BP observed in spontaneously hypertensive rats due to miR-193b-3p overexpression was greatly counteracted by Arhgef9 upregulation. CONCLUSIONS: miR-193b-3p and miR-346 are newly identified factors in RVLM that hinder hypertension progression, and the miR-193b-3p/Arhgef9/apoptosis pathway presents a potential mechanism, highlighting the potential of targeting miRNAs for hypertension prevention.

miR-346 regulates the development of ARDS by regulating the function of pulmonary microvascular endothelial cells.

In recent years, many studies have reported that microRNAs play an important role in the pathogenesis of a variety of diseases, and the aim of this paper is to explore the role and mechanism of miR-346 in acute respiratory distress syndrome (ARDS). A mouse model of ARDS was constructed by LPS induction, and RT-qPCR assay was used to verify that the expression level of miR-346 in lung tissue was significantly increased, and was negatively correlated with oxygenation index. Inhibiting the expression of miR-346 in mice and HPMECs by miR-346 inhibitor confirmed that decreased miR-346 expression could lead to increased oxygenation index, decreased lung index, lung water content and NO content to reduce lung injury in mice, while lung inflammation was alleviated and apoptosis was reduced in mice. The same results were obtained in cells. BCL6 was predicted to be a target of miR-346 by targetscan and miRDB; when miR-346 was inhibited, BCL6 expression was increased, and if miR-346 and BCL6 expression were inhibited at the same time, it could aggravate lung injury and reduce the proliferation of HPMECs and increase their apoptosis and inflammation in mice. This shows that miR-346 inhibits the migration of HPMECs by regulating BCL6 expression, which in turn promotes the apoptosis of HPMECs, leading to inflammation and inducing ARDS.

CircGAB1 Facilitates Podocyte Injury Through Sponging miR-346 and Activating MAPK6 in Diabetic Nephropathy.

BACKGROUND: Podocyte injury is very important process in diabetic nephropathy (DN) progression. Circular RNA (circRNA) takes part in regulating the advancement of DN. Herein, we explored the role and mechanism of circGAB1 in DN progression. METHODS: The abundances of circGAB1, microRNA-346 (miR-346) and mitogen-activated protein kinase 6 (MAPK6) were detected by qRT-PCR in DN serum samples and podocyte HGPC. Moreover, cell viability and apoptosis were determined using CCK8 assay and flow cytometry. Also, the protein levels of MAPK6, proliferation-related markers and apoptosis-related markers were analyzed by western blot. ELISA assay was used to measure the levels of inflammatory factors, and corresponding kits were used to detect the levels of oxidative stress-related markers. The relationship between miR-346 and circGAB1 or MAPK6 was distinguished by dual-luciferase reporter assay. RESULTS: CircGAB1 expression was increased in DN serum samples and HG-treated HGPC cells. CircGAB1 knockdown inhibited HG-induced apoptosis, inflammatory response and oxidative stress in HGPC cells. In terms of mechanism, circGAB1 sponged miR-346, and miR-346 targeted MAPK6. The inhibition effect of circGAB1 knockdown on HG-induced podocyte injury could be reversed by miR-346 inhibitor. Moreover, miR-346 overexpression repressed HG-induced podocyte injury by targeting MAPK6. CircGAB1 served as miR-346 sponge to positively regulate MAPK6. CONCLUSION: CircGAB1 contributed to podocyte injury through mediating miR-346/MAPK6 axis, suggesting that circGAB1 might promote DN progression.

CircHIPK3 contributes to human villous trophoblast growth, migration and invasion via modulating the pathway of miR-346/KCMF1.

INTRODUCTION: Preeclampsia (PE) is one of the leading causes of maternal and perinatal morbidity and mortality worldwide. The regular growth, migration and invasion of villous trophoblast cells contribute to placental development. The objective of this study was to investigate the role and mechanism of circular RNA homeodomain interacting protein kinase 3 (circHIPK3) in the biological functions of trophoblast cells. METHODS: The expression of circHIPK3, microRNA-346 (miR-346) and potassium channel modulatory factor 1 (KCMF1) mRNA was measured by quantitative real-time PCR (qPCR). Trophoblast cell proliferation, migration/invasion and cell cycle progression/apoptosis were determined by CCK-8 assay, transwell assay and flow cytometry assay, respectively. The predicted relationship between miR-346 and circHIPK3 or KCMF1 by bioinformatics was confirmed dual-luciferase reporter assay and RIP assay. RESULTS: CircHIPK3 and KCMF1 were downregulated, while miR-346 was upregulated in placenta tissues from PE patients. The forced expression of circHIPK3 promoted trophoblast cell proliferation and migration/invasion but alleviated cell cycle arrest and cell apoptosis. MiR-346 was a target of circHIPK3, and miR-346 restoration reversed the effects of circHIPK3 upregulation. In addition, circHIPK3 acted as miR-346 sponge to modulate KCMF1 expression. KCMF1 downregulation partially repressed trophoblast cell proliferation, migration and invasion that were facilitated by miR-346 inhibition or circHIPK3 upregulation. DISCUSSION: CircHIPK3 contributes to trophoblast cell proliferation, migration and invasion by upregulating KCMF1 via acting as miR-346 sponge.