LncRNA SNHG1 enhances cartilage regeneration by modulating chondrogenic differentiation and angiogenesis potentials of JBMMSCs via mitochondrial function regulation.

BACKGROUND: Cartilage is a kind of avascular tissue, and it is difficult to repair itself when it is damaged. In this study, we investigated the regulation of chondrogenic differentiation and vascular formation in human jaw bone marrow mesenchymal stem cells (h-JBMMSCs) by the long-chain noncoding RNA small nucleolar RNA host gene 1 (SNHG1) during cartilage tissue regeneration. METHODS: JBMMSCs were isolated from the jaws via the adherent method. The effects of lncRNA SNHG1 on the chondrogenic differentiation of JBMMSCs in vitro were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), Pellet experiment, Alcian blue staining, Masson's trichrome staining, and modified Sirius red staining. RT-qPCR, matrix gel tube formation, and coculture experiments were used to determine the effect of lncRNA SNHG1 on the angiogenesis in JBMMSCs in vitro. A model of knee cartilage defects in New Zealand rabbits and a model of subcutaneous matrix rubber suppositories in nude mice were constructed for in vivo experiments. Changes in mitochondrial function were detected via RT-qPCR, dihydroethidium (DHE) staining, MitoSOX staining, tetramethyl rhodamine methyl ester (TMRM) staining, and adenosine triphosphate (ATP) detection. Western blotting was used to detect the phosphorylation level of signal transducer and activator of transcription 3 (STAT3). RESULTS: Alcian blue staining, Masson's trichrome staining, and modified Sirius Red staining showed that lncRNA SNHG1 promoted chondrogenic differentiation. The lncRNA SNHG1 promoted angiogenesis in vitro and the formation of microvessels in vivo. The lncRNA SNHG1 promoted the repair and regeneration of rabbit knee cartilage tissue. Western blot and alcian blue staining showed that the JAK inhibitor reduced the increase of STAT3 phosphorylation level and staining deepening caused by SNHG1. Mitochondrial correlation analysis revealed that the lncRNA SNHG1 led to a decrease in reactive oxygen species (ROS) levels, an increase in mitochondrial membrane potential and an increase in ATP levels. Alcian blue staining showed that the ROS inhibitor significantly alleviated the decrease in blue fluorescence caused by SNHG1 knockdown. CONCLUSIONS: The lncRNA SNHG1 promotes chondrogenic differentiation and angiogenesis of JBMMSCs. The lncRNA SNHG1 regulates the phosphorylation of STAT3, reduces the level of ROS, regulates mitochondrial energy metabolism, and ultimately promotes cartilage regeneration.

WTAP-mediated m6A modification of lncRNA Snhg1 improves myocardial ischemia-reperfusion injury via miR-361-5p/OPA1-dependent mitochondrial fusion.

BACKGROUND: Myocardial ischemia-reperfusion injury (MIRI) is caused by reperfusion after ischemic heart disease. LncRNA Snhg1 regulates the progression of various diseases. N6-methyladenosine (m6A) is the frequent RNA modification and plays a critical role in MIRI. However, it is unclear whether lncRNA Snhg1 regulates MIRI progression and whether the lncRNA Snhg1 was modified by m6A methylation. METHODS: Mouse cardiomyocytes HL-1 cells were utilized to construct the hypoxia/reoxygenation (H/R) injury model. HL-1 cell viability was evaluated utilizing CCK-8 method. Cell apoptosis, mitochondrial reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) were quantitated utilizing flow cytometry. RNA immunoprecipitation and dual-luciferase reporter assays were applied to measure the m6A methylation and the interactions between lncRNA Snhg1 and targeted miRNA or target miRNAs and its target gene. The I/R mouse model was constructed with adenovirus expressing lncRNA Snhg1. HE and TUNEL staining were used to evaluate myocardial tissue damage and apoptosis. RESULTS: LncRNA Snhg1 was down-regulated after H/R injury, and overexpressed lncRNA Snhg1 suppressed H/R-stimulated cell apoptosis, mitochondrial ROS level and polarization. Besides, lncRNA Snhg1 could target miR-361-5p, and miR-361-5p targeted OPA1. Overexpressed lncRNA Snhg1 suppressed H/R-stimulated cell apoptosis, mitochondrial ROS level and polarization though the miR-361-5p/OPA1 axis. Furthermore, WTAP induced lncRNA Snhg1 m6A modification in H/R-stimulated HL-1 cells. Moreover, enforced lncRNA Snhg1 repressed I/R-stimulated myocardial tissue damage and apoptosis and regulated the miR-361-5p and OPA1 levels. CONCLUSION: WTAP-mediated m6A modification of lncRNA Snhg1 regulated MIRI progression through modulating myocardial apoptosis, mitochondrial ROS production, and mitochondrial polarization via miR-361-5p/OPA1 axis, providing the evidence for lncRNA as the prospective target for alleviating MIRI progression.

lncRNA SNHG1 promotes the progression of hepatocellular carcinoma by regulating the miR-7-5p/IGF2BP2 axis.

Long noncoding RNA small nucleolar RNA host gene 1 (lncRNA SNHG1) plays a crucial role in the occurrence and progression of various tumors. This study investigates the function of lncRNA SNHG1 in hepatocellular carcinoma (HCC). We discovered that lncRNA SNHG1 is significantly upregulated in HCC and markedly enhances cell proliferation, migration, and invasion, while simultaneously suppressing apoptosis in HCC cells. Furthermore, lncRNA SNHG1 was found to downregulate miR-7-5p expression. Overexpression of lncRNA SNHG1 counteracted the suppression of HCC cell migration, proliferation, and invasion caused by miR-7-5p mimics, and reversed the miR-7-5p mimics' enhancement of apoptosis in HCC cells. Additionally, miR-7-5p was shown to negatively regulate IGF2BP2, with the silencing of IGF2BP2 diminishing the abilities of HCC cells to proliferate, migrate, and invade, and increasing their propensity for apoptosis. Overexpression of lncRNA SNHG1 negated these effects. Thus, lncRNA SNHG1 fosters HCC progression by upregulating IGF2BP2 expression through targeting miR-7-5p.

Tumorigenesis of basal muscle invasive bladder cancer was mediated by PTEN protein degradation resulting from SNHG1 upregulation.

BACKGROUND: Phosphatase and tensin homolog deleted on chromosome ten (PTEN) serves as a powerful tumor suppressor, and has been found to be downregulated in human bladder cancer (BC) tissues. Despite this observation, the mechanisms contributing to PTEN's downregulation have remained elusive. METHODS: We established targeted genes' knockdown or overexpressed cell lines to explore the mechanism how it drove the malignant transformation of urothelial cells or promoted anchorageindependent growth of human basal muscle invasive BC (BMIBC) cells. The mice model was used to validate the conclusion in vivo. The important findings were also extended to human studies. RESULTS: In this study, we discovered that mice exposed to N-butyl-N-(4-hydroxybu-tyl)nitrosamine (BBN), a specific bladder chemical carcinogen, exhibited primary BMIBC accompanied by a pronounced reduction in PTEN protein expression in vivo. Utilizing a lncRNA deep sequencing high-throughput platform, along with gain- and loss-of-function analyses, we identified small nucleolar RNA host gene 1 (SNHG1) as a critical lncRNA that might drive the formation of primary BMIBCs in BBN-treated mice. Cell culture results further demonstrated that BBN exposure significantly induced SNHG1 in normal human bladder urothelial cell UROtsa. Notably, the ectopic expression of SNHG1 alone was sufficient to induce malignant transformation in human urothelial cells, while SNHG1 knockdown effectively inhibited anchorage-independent growth of human BMIBCs. Our detailed investigation revealed that SNHG1 overexpression led to PTEN protein degradation through its direct interaction with HUR. This interaction reduced HUR binding to ubiquitin-specific peptidase 8 (USP8) mRNA, causing degradation of USP8 mRNA and a subsequent decrease in USP8 protein expression. The downregulation of USP8, in turn, increased PTEN polyubiquitination and degradation, culminating in cell malignant transformation and BMIBC anchorageindependent growth. In vivo studies confirmed the downregulation of PTEN and USP8, as well as their positive correlations in both BBN-treated mouse bladder urothelium and tumor tissues of bladder cancer in nude mice. CONCLUSIONS: Our findings, for the first time, demonstrate that overexpressed SNHG1 competes with USP8 for binding to HUR. This competition attenuates USP8 mRNA stability and protein expression, leading to PTEN protein degradation, consequently, this process drives urothelial cell malignant transformation and fosters BMIBC growth and primary BMIBC formation.

LncRNA SNHG1 alleviates myocardial ischaemia-reperfusion injury by regulating the miR-137-3p/KLF4/TRPV1 axis.

AIMS: Myocardial ischaemia-reperfusion injury (MIRI) contributes to serious myocardial injury and even death. Long non-coding RNAs (lncRNAs) have been reported to play pivotal roles in the occurrence and development of MIRI. Here, the detailed molecular mechanism of lncRNA SNHG1 in MIRI was explored. METHODS AND RESULTS: A cell model of MIRI was established through hypoxia/reoxygenation (H/R) stimulation. Cell viability and pyroptosis were evaluated utilizing MTT, PI staining, and flow cytometry. Interleukin (IL)-1ß and IL-18 secretion levels were examined by ELISA. The gene and protein expression were detected by RT-qPCR and western blot, respectively. Dual luciferase reporter gene, RIP and ChIP assays were performed to analyse the molecular interactions. The results showed that lncRNA SNHG1 overexpression alleviated H/R-induced HL-1 cell pyroptosis (all P < 0.05). LncRNA SNHG1 promoted KLF4 expression by sponging miR-137-3p. miR-137-3p silencing alleviated H/R-induced pyroptosis in HL-1 cells (all P < 0.05), which was abolished by KLF4 knockdown (all P < 0.05). KLF4 activated the AKT pathway by transcriptionally activating TRPV1 in HL-1 cells (all P < 0.05). TRPV1 knockdown reversed the alleviation of SNHG1 upregulation on H/R-induced pyroptosis in HL-1 cells (all P < 0.05). CONCLUSIONS: These results showed that lncRNA SNHG1 assuaged cardiomyocyte pyroptosis during MIRI progression by regulating the KLF4/TRPV1/AKT axis through sponging miR-137-3p. Our findings may provide novel therapeutic targets for MIRI.

The mechanism of lncRNA SNHG1 in osteogenic differentiation via miR-497-5p/ HIF1AN axis.

The pivotal role of lncRNAs in osteoporosis progression and development necessitates a comprehensive exploration of the functional and precise molecular mechanisms underlying lncRNA SNHG1's regulation of osteoblast differentiation and calcification. The study involved inducing BMSCs cells to differentiate into osteoblasts, followed by transfections of miR-497-5p inhibitors, pcDNA3.1-SNHG1, sh-HIF1AN, miR-497-5p mimics, and respective negative controls into BMSCs. Quantitative PCR (qPCR) was employed to assess the expression of SNHG1 and miR-497-5p. Western Blotting was conducted to measure the levels of short stature-related transcription factor 2 (RUNX2), osteopontin (OPN), osteocalcin (OCN), and HIF1AN. Alkaline phosphatase (ALP) activity was determined using appropriate assay kits. Calcium nodule staining was performed through Alizarin red staining. Dual luciferase reporter gene assays were executed to validate the interaction between SNHG1 and miR-497-5p, as well as HIF1AN. Throughout osteogenic differentiation, there was a down-regulation of SNHG1 and HIF1AN, in contrast to an elevation in miR-497-5p levels. Direct interactions between miR-497-5p and both SNHG1 and HIF1AN were observed. Notably, SNHG1 exhibited the ability to modulate HIF1AN by influencing miR-497-5p, thereby inhibiting osteogenic differentiation. Functioning as a competitive endogenous RNA, lncRNA SNHG1 exerts an inhibitory influence on osteogenic differentiation via the miR-497-5p/HIF1AN axis. This highlights the potential for lncRNA SNHG1 to emerge as a promising therapeutic target for osteoporosis. The study's findings pave the way for a novel target strategy in the future treatment of osteoporosis.

SNHG1/miR-21 axis mediates the cardioprotective role of aloin in sepsis through modulating cardiac cell viability and inflammatory responses.

BACKGROUND: Aloin has cardioprotective effects, however, its cardioprotective role in sepsis remains unclear. This study aimed to analyze whether aloin could prevent sepsis-related myocardial damage and explore the underlying mechanisms by examining the expression of long-noncoding RNA (lncRNA) SNHG1 and microRNA-21 (miR-21). METHODS: The interaction of SNHG1 with miR-21 was identified by dual-luciferase reporter assay. The levels of SNHG1 and miR-21 were measured by real-time quantitative PCR. The cardioprotective function of aloin was assessed in a sepsis animal model, which was induced by cecal ligation and puncture, and in a myocardial injury cell model in H9C2 cells stimulated by lipopolysaccharide. Myocardial injury biomarker levels and hemodynamic indicators in mice model were measured to evaluate cardiac function. The viability of H9C2 cells was assessed by cell counting kit-8 assay. Inflammatory cytokine levels were examined by an ELISA method. RESULTS: Decreased SNHG1 and increased miR-21 were found in sepsis patients with cardiac dysfunction, and they were negatively correlated. Aloin significantly attenuated myocardial damage and inflammatory responses of mice model, and increased the viability and suppressed inflammation in H9C2 cell model. In addition, SNHG1 expression was upregulated and miR-21 expression was downregulated by aloin in both mice and cell models. Moreover, in mice and cell models, SNHG1/miR-21 axis affected sepsis-related myocardial damage, and mediated the cardioprotective effects of aloin. CONCLUSION: Our findings indicated that aloin exerts protective effects in sepsis-related myocardial damage through regulating cardiac cell viability and inflammatory responses via regulating the SNHG1/miR-21 axis.

LncRNA SNHG1 knockdown inhibits hyperglycemia induced ferroptosis via miR-16-5p/ACSL4 axis to alleviate diabetic nephropathy.

BACKGROUND: Hyperglycemia accelerates the development of diabetic nephropathy (DN) by inducing renal tubular injury. Nevertheless, the mechanism has not been elaborated fully. Here, the pathogenesis of DN was investigated to seek novel treatment strategies. METHODS: A model of diabetic nephropathy was established in vivo, the levels of blood glucose, urine albumin creatinine ratio (ACR), creatinine, blood urea nitrogen (BUN), malondialdehyde (MDA), glutathione (GSH), and iron were measured. The expression levels were detected by qRT-PCR and Western blotting. H&E, Masson, and PAS staining were used to assess kidney tissue injury. The mitochondria morphology was observed by transmission electron microscopy (TEM). The molecular interaction was analyzed using a dual luciferase reporter assay. RESULTS: SNHG1 and ACSL4 were increased in kidney tissues of DN mice, but miR-16-5p was decreased. Ferrostatin-1 treatment or SNHG1 knockdown inhibited ferroptosis in high glucose (HG)-treated HK-2 cells and in db/db mice. Subsequently, miR-16-5p was confirmed to be a target for SNHG1, and directly targeted to ACSL4. Overexpression of ACSL4 greatly reversed the protective roles of SNHG1 knockdown in HG-induced ferroptosis of HK-2 cells. CONCLUSIONS: SNHG1 knockdown inhibited ferroptosis via the miR-16-5p/ACSL4 axis to alleviate diabetic nephropathy, which provided some new insights for the novel treatment of diabetic nephropathy.

Suppression of lncRNA Snhg1 inhibits high glucose-induced inflammation and proliferation in mouse mesangial cells.

Diabetic nephropathy (DN) is the direct cause of end-stage renal disease, and nephritic inflammation plays a role in its growth and advancement. Aberrant expression of long non-coding RNAs (lncRNAs) correlates with many diseases, including DN. In this study, we investigated whether lncRNA small nucleolar RNA host gene 1 (Snhg1) was mechanistically involved in inflammation and mesangial cell (MC) proliferation in DN. We found that Snhg1 was significantly upregulated in DN renal tissues and high glucose (HG)-treated MCs. Overexpression of Snhg1 promoted inflammatory cytokine expression in MCs and MC proliferation under low-glucose conditions; meanwhile, Snhg1 knockdown suppressed inflammatory cytokine production and MC proliferation under HG conditions. Mechanistically, Snhg1 was found to directly bind miR-27b, thereby preventing the miRNA from binding its target KDM6B mRNA. Furthermore, miR-27b overexpression recapitulated the inhibitory effects of Snhg1 knockdown, whereas restoration of Snhg1 expression attenuated the function of miR-27b in MCs under HG conditions. Taken together, these results indicate that suppression of Snhg1 inhibited HG-induced inflammation and proliferation of MCs by regulating the miR-27b/KDM6B axis.

LncRNA SNHG1 targets miR-340-5p/PIK3CA axis to regulate microvascular endothelial cell proliferation, migration, and angiogenesis in DR.

Diabetic retinopathy (DR) is a serious long-term complication of diabetes. However, the current treatment of DR is still challenging. We aimed to investigate the role of lncRNA SNHG1/miR-340-5p/PIK3CA in DR and the mechanisms involved. Blood samples from clinical DR patients and healthy subjects were obtained. HRMECs were induced by high glucose for 24 h to establish the DR model. The vector for interfering or overexpressing lncRNA SNHG1, miR-340-5p, and PIK3CA was constructed. LncRNA SNHG1, miR-340-5p, and PIK3CA expressions were detected by qRT-PCR or Western blot. Cell proliferation and migration were detected by CCK-8 and Transwell assays. Blood vessel formation was detected by angiogenesis assay. Dual-luciferase reporter assay tested the interaction of lncRNA SNHG1 with miR-340-5p and miR-340-5p with PIK3CA. RIP measured the binding of miR-340-5p to PIK3CA. In the blood of DR patients and the DR model, lncRNA SNHG1 was increased and miR-340-5p expression was down-regulated. In the DR model, PIK3CA expression was elevated. Downregulation of lncRNA SNHG1 inhibited HRMECs proliferation, migration, and angiogenesis. LncRNA SNHG1 interacted with miR-340-5p, and up-regulation of miR-340-5p inhibited HRMECs proliferation, migration and angiogenesis. The inhibition of cell proliferation, migration, and angiogenesis of HRMECs caused by down-regulation of lncRNA SNHG1 was reversed by knockdown of miR-340-5p. miR-340-5p targeted PIK3CA, and downregulation of PIK3CA inhibited HRMECs proliferation, migration, and angiogenesis. The inhibition of HRMECs proliferation, migration and angiogenesis caused by down-regulation of lncRNA SNHG1 could be reversed by overexpression of PIK3CA. LncRNA SNHG1 targeted miR-340-5p/PIK3CA axis to regulate microvascular endothelial cell proliferation, migration, and angiogenesis in DR.

LncRNA-SNHG1 promotes paclitaxel resistance of gastric cancer cells through modulating the miR-216b-5p-hexokianse 2 axis.

Gastric cancer (GC) is one of the most malignant tumors with high incidence and poor prognosis. Currently, the combination of surgery with chemo- or radiotherapy is widely applied therapeutic strategy against GC. However, development of drug resistance severely limited the clinical application of chemotherapy. Small nucleolar RNA host gene 1 (SNHG1) has been reported to be frequently overexpressed in diverse human tumors. Yet, the biological roles and mechanisms of SNHG1 in chemoresistant GC remain unclear. Expressions of lncRNA and miRNA were detected by qRT-PCR. Responses of GC cells to Taxol treatments were evaluated by cell viability assay and apoptosis assay. Glucose metabolism rate was examined by glucose uptake and extracellular acidification rate (ECAR). The lncRNA-miRNA interaction was validated by RNA pull-down assay and luciferase assays. This study reports that expressions of SNHG1 were significantly elevated in patients with GC and gastric cancer cell lines. Silencing SNHG1 effectively suppressed GC cells migration and increased the Taxol sensitivity of GC cells. Moreover, we detected remarkedly upregulated SNHG1 expression and increased glucose metabolism in Taxol resistant cell line, MKN-45 TXR. Low glucose supply rendered Taxol resistant cells more susceptible to Taxol treatment compared with that from MKN-45 parental cells. Bioinformatical analysis, RNA pull-down and luciferase assays verified that SNHG1 functioned as a ceRNA of miR-216b-5p in GC cells. Consistently, we detected miR-216b-5p was significantly downregulated in GC tumor specimens and Taxol resistant GC cells. The hexokinase 2 (HK2), a glucose metabolism key enzyme, was predicted and validated as a direct target of miR-216b-5p in GC cells. Finally, restoration of miR-216b-5p in SNHG1-overexpressing MKN-45 TXR cells successfully overrode the SNHG1-promoted Taxol resistance through targeting the HK2-glycolysis axis. This study uncovered new biological roles and molecular mechanisms of the lncRNA-SNHG1-mediated Taxol resistance of gastric cancer, suggesting targeting the SNHG1-miR-216b-5p-HK2 axis could be a potentially therapeutic approach against chemoresistant gastric cancer.

SNHG1/miR-186/FUT8 regulates cell migration and invasion in oral squamous cell carcinoma.

Recently, lncRNAs are associated with the progression and development of various cancers. We aimed to explore the effects of lncRNA SNHG1 on the proliferation, apoptosis, migration, and invasion of oral squamous cell carcinoma (OSCC) cells. Quantitative real-time PCR (RT-qPCR) was used for measurement of SNHG1 in OSCC cells. Cell proliferation, apoptosis, migration, and invasion were detected by CCK-8 assay, flow cytometry, Cell Death Detection ELISA PLUS kit, and transwell assays. Dual-luciferase reporter assay and RNA-binding protein immunoprecipitation (RIP) assay were used to clarify the relationship between SNHG1 and miR-186. SNHG1 was overexpressed in OSCC cells. SNHG1 silencing prevented cell proliferation and increased the incidence of apoptosis, DNA fragments, cleaved-caspase 3, and Bax protein levels. Cell migration and invasion were reduced after SNHG1 deletion, and MMP2 and MMP9 protein levels were decreased. SNHG1 overexpression promoted cell survival, migration, and invasion, reduced DNA fragments formation. Mechanistically, we demonstrated that SNHG1 could directly bind to miR-186 and positively regulated α1, 6-fucosyltransferase (FUT8) level. Functional investigation showed that miR-186 depletion reversed the roles of SNHG1 silencing in cell proliferation, apoptosis, and migration. Taken together, our findings illuminated that SNHG1 regulated cell proliferation, migration, and invasion by sponging miR-186 to depress FUT8 expression.

lncRNA SNHG1 regulates odontogenic differentiation of human dental pulp stem cells via miR-328-3p/Wnt/ß-catenin pathway.

BACKGROUND: Elucidating the mechanism of odontogenic differentiation of human dental pulp stem cells (hDPSCs) is the key to in-depth mastery and development of regenerative endodontic procedures (REPs). In odontogenic differentiation, lncRNAs have a regulatory role. The goal of this research is to determine the involvement of short nucleolar RNA host gene 1 (SNHG1) in hDPSCs' odontogenic differentiation and the mechanism that underpins it. METHODS: hDPSCs were isolated from the dental pulp tissue of healthy immature permanent teeth. Follow-up experiments were performed when the third generation of primary cells were transfected. The proliferation ability was measured by CCK-8. The biological effects of SNHG1 and miR-328-3p were determined by real-time quantitative polymerase chain reaction (qRT-PCR), western blot (WB), alkaline phosphatase (ALP) staining and activity, alizarin red S staining (ARS) and quantification, and immunofluorescence staining. The binding of SNHG1 and miR-328-3p was confirmed using a dual-luciferase reporter assay. qRT-PCR and WB were used to determine whether the canonical Wnt/ß-catenin pathway was activated. RESULTS: On the 0th, 3rd, and 7th days of odontogenic differentiation of hDPSCs, SNHG1 showed a gradual up-regulation trend. SNHG1 overexpression enhanced the mRNA and protein expression of dentin sialophosphoprotein (DSPP), dentine matrix protein 1 (DMP-1) and ALP. We found that SNHG1 could bind to miR-328-3p. miR-328-3p inhibited the odontogenic differentiation of hDPSCs. Therefore, miR-328-3p mimics rescued the effect of SNHG1 overexpression on promoting odontogenic differentiation. In addition, SNHG1 inhibited Wnt/ß-catenin pathway via miR-328-3p in odontogenic differentiation of hDPSCs. CONCLUSION: lncRNA SNHG1 inhibits Wnt/ß-catenin pathway through miR-328-3p and then promotes the odontogenic differentiation of hDPSCs.

Long non-coding RNA SNHG1 activates glycolysis to promote hepatocellular cancer progression through the miR-326/PKM2 axis.

BACKGROUND: Hepatocellular cancer (HCC) is a lethal malignancy with extremely poor prognosis. In the present study, we aimed to investigate the role and underlying mechanism of SNHG1 in HCC progression. METHODS: Combined with bioinformatics and experimental validation, we explored the clinical significance of SNHG1 in HCC. A Cell Counting Kit-8 assay, cell colony formation assay, and subcutaneous tumorigenesis experiments of nude mice were conducted to evaluate the pro-proliferative capacity of SNHG1. Glucose consumption and lactate production were measured to explore the regulatory role of SNHG1 in glycolysis. Nuclear-cytoplasmic separation, quantitative real-time polymerase chain reaction and Western blot assays, chromatin immunoprecipitation, and luciferase reporter and RNA immunoprecipitation assays were performed to investigate the molecular mechanisms of SNHG1 in HCC. RESULTS: SNHG1 expression was dramatically increased in HCC and positively correlated with poor prognosis. E2F1 bound to the SNHG1 promoter region to activate SNHG1 transcription. Furthermore, SNHG1 served as a molecular sponge for miR-326 to sequester the interaction of miR-326 and pyruvate kinase M2 (PKM2), facilitating the expression of PKM2. Activating PKM2 expression was revealed to be one of mechanisms of SNHG1 with respect to promoting glycolysis and the proliferation of HCC cells. CONCLUSIONS: E2F1-activated SNHG1 modulates the miR-326/PKM2 axis to facilitate glycolysis and the proliferation of HCC cells. Targeting SNHG1 could be a promising therapeutic option for HCC.

LncRNA SNHG1 Promotes the Progression of Pancreatic Cancer by Regulating FGFR1 Expression via Competitively Binding to miR-497.

BACKGROUND: Long noncoding RNA small nucleolar RNA host gene 1 (SNHG1) is dysregulated in a variety of tumors. However, little is known of its role in pancreatic cancer (PC). METHODS: The role of SNHG1 on PC cell proliferation, migration, invasion, apoptosis, and the epithelial-mesenchymal transition (EMT) were assessed in vitro using MTT, EDU, wound healing, and Transwell assays, as well as flow cytometry and western blotting. Luciferase reporter assay, western blotting, and qRT-PCR were used to examine SNHG1 regulation. Tumor growth in mice was also investigated. RESULTS: Downregulation of SNHG1 blocked cell proliferation, migration and invasion, and induced apoptosis in vitro, while also inhibiting the EMT, shown by changes in the biomarkers E-cadherin, N-cadherin, and Vimentin. The opposite results were observed on upregulation of SNHG1. In vivo experiments showed that downregulation of SNHG1 inhibited tumor development in nude mice. Furthermore, experiments investigating the regulatory mechanism of SNHG1 indicated that SNHG1 acted as a competitive endogenous RNA, positively regulating the expression of fibroblast growth factor receptor 1 (FGFR1) through sponging miR-497. Rescue experiments demonstrated that the effects of SNHG1 downregulation on PC cells were attenuated when simultaneously inhibiting the levels of miR-497. CONCLUSIONS: SNHG1 upregulates FGFR1 expression by sponging miR-497, which promotes the progression of PC. SNHG1 may thus be a novel target for treating PC.

SNHG1 functions as an oncogenic lncRNA and promotes osteosarcoma progression by up-regulating S100A6 via miR-493-5p.

The mechanism behind the aberrant expression of S100A6 in osteosarcoma is seldom reported so far. This study sought to explore the regulatory axis targeting S100A6 involved in osteosarcoma progression. Clinical samples collected from osteosarcoma patients were used to detect the expressions of SNHG1, miR-493-5p, and S100A6 by western bolt analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The effects of S100A6 on proliferation and osteogenic differentiation were investigated by the CCK-8 assay, colony formation assay, Ethynyl deoxyuridine staining, matrix mineralization assay, and alkaline phosphatase assay. The potential of lncRNAs/miRNAs targeting S100A6 was identified by the bioinformatics approach, and the results were verified by the dual luciferase assay and RNA immunoprecipitation assay. Both and rescue experiments were performed to investigate the regulatory relationship between the identified lncRNAs and S100A6. The results showed that S100A6 is highly expressed in osteosarcoma. S100A6 overexpression not only increases the proliferation but also reduces the osteogenic differentiation of osteosarcoma cells, while S1006A silence exerts the opposite effects. Then, SNHG1 is identified to directly interact with miR-493-5p to attenuate miR-493-5p binding to the 3'-untranslated region of S100A6. Notably, S100A6 silence partially rescues the effect of SNHG1 overexpression on proliferation and osteogenic differentiation of osteosarcoma cells. Furthermore, the suppressive role of SNHG1 silence in the growth of osteosarcoma xenograft tumors is countered by S100A6 overexpression. Collectively, this study reveals that S100A6 plays an important role in osteosarcoma progression, and SNHG1 promotes S100A6 expression by competitively sponging miR-493-5p.

LncRNA SNHG1 modulates adipogenic differentiation of BMSCs by promoting DNMT1 mediated Opg hypermethylation via interacting with PTBP1.

Recent evidence indicates that the abnormal differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) plays a pivotal role in the pathogenesis of osteoporosis. LncRNA SNHG1 has been found to be associated with the differentiation ability of BMSCs. In this study, we aimed to elucidate the role of lncRNA SNHG1 and its associated pathway on the differentiation of BMSCs in osteoporosis. Mice that underwent bilateral ovariectomy (OVX) were used as models of osteoporosis. Induced osteogenic or adipogenic differentiation was performed in mouse BMSCs. Compared to sham animals, lncRNA SNHG1 expression was upregulated in OVX mice. Also, the in vitro expression of SNHG1 was increased in adipogenic BMSCs but decreased in osteogenic BMSCs. Moreover, overexpression of SNHG1 enhanced the adipogenic capacity of BMSCs but inhibited their osteogenic capacity as determined by oil red O, alizarin red, and alkaline phosphatase staining, while silencing of SNHG1 led to the opposite results. LncRNA SNHG1 interacting with the RNA-binding polypyrimidine tract-binding protein 1 (PTBP1) promoted osteoprotegerin (Opg) methylation and suppressed Opg expression via mediating DNA methyltransferase (DNMT) 1. Furthermore, Opg was showed to regulate BMSC differentiation. Knockdown of SNHG1 decreased the expressions of adipogenic related genes but increased that of osteogenic related genes. However, the knockdown of Opg partially reversed those effects. In summary, lncRNA SNHG1 upregulated the expression of DNMT1 via interacting with PTBP1, resulting in Opg hypermethylation and decreased Opg expression, which in turn enhanced BMSC adipogenic differentiation and contributed to osteoporosis.

Long non-coding RNA SNHG1 promotes fibroblast-to-myofibroblast transition during the development of pulmonary fibrosis induced by silica particles exposure.

Inhaling silica dust in the environment can cause progressive pulmonary fibrosis, then silicosis. Silicosis is the most harmful occupational disease in the world, so the study of the mechanism is of great significance for the prevention and treatment of silicosis. Long non-coding RNAs (lncRNAs) are important players in the pathological process of fibrotic diseases. However, the function of specific lncRNA in regulating pulmonary fibrosis remains elusive. In this study, a mouse model of pulmonary fibrosis via intratracheal instillation of silica particles was established, and the differential expression of lnc-SNHG1 and miR-326 in lung tissues and TGF-ß1-treated fibroblasts was detected by the qRT-PCR method. Short interfering RNA (siRNA) and plasmid were designed for knockdown or overexpression of lnc-SNHG1 in fibroblasts. MiRNA simulant was designed for overexpression of miR-326 in vivo and in vitro. Dual-luciferase reporter system, immunofluorescence, western blot, wound healing and transwell assay were performed to investigate the function and the underlying mechanisms of lnc-SNHG1. As a result, we found that lnc-SNHG1 was highly expressed in fibrotic lung tissues of mice and TGF-ß1-treated fibroblasts. Moreover, the high expression of lnc-SNHG1 facilitated the migration and invasion of fibroblasts and the secretion of fibrotic molecules, while the low expression of lnc-SNHG1 exerted the opposite effects. Further mechanism studies showed that miR-326 was the potential target of lnc-SNHG1, and there is a negative correlation between the expression levels of lnc-SNHG1 and miR-326. Combined with mitigating fibrotic effects of miR-326 in a mouse model of silica particles exposure, we revealed that lnc-SNHG1 significantly sponged miR-326 and facilitated the expression of SP1, thus accelerating fibroblast-to-myofibroblast transition and synergistically promoting the development of pulmonary fibrosis. Our study uncovered a key mechanism by which lnc-SNHG1 regulated pulmonary fibrosis through miR-326/SP1 axis, and lnc-SNHG1 is a potential target for the prevention and treatment of silicosis.

lncRNA SNHG1 induced by SP1 regulates bone remodeling and angiogenesis via sponging miR-181c-5p and modulating SFRP1/Wnt signaling pathway.

BACKGROUND: We aimed to investigate the functions and underlying mechanism of lncRNA SNHG1 in bone differentiation and angiogenesis in the development of osteoporosis. METHODS: The differential gene or proteins expressions were measured by qPCR or western blot assays, respectively. The targeted relationships among molecular were confirmed through luciferase reporter, RIP and ChIP assays, respectively. Alkaline phosphatase (ALP), alizarin red S (ARS) and TRAP staining were performed to measure the osteoblast/osteoclast differentiation of BMSCs. The viability, migration and angiogenesis in BM-EPCs were validated by CCK-8, clone formation, transwell and tube formation assays, respectively. Western blot and immunofluorescence detected the cytosolic/nuclear localization of ß-catenin. Ovariectomized (OVX) mice were established to confirm the findings in vitro. RESULTS: SNHG1 was enhanced and miR-181c-5p was decreased in serum and femoral tissue from OVX mice. SNHG1 directly inhibited miR-181c-5p to activate Wnt3a/ß-catenin signaling by upregulating SFRP1. In addition, knockdown of SNHG1 promoted the osteogenic differentiation of BMSCs by increasing miR-181c-5p. In contrast, SNHG1 overexpression advanced the osteoclast differentiation of BMSCs and inhibited the angiogenesis of BM-EPCs, whereas these effects were all reversed by miR-181c-5p overexpression. In vivo experiments indicated that SNHG1 silencing alleviated osteoporosis through stimulating osteoblastogenesis and inhibiting osteoclastogenesis by modulating miR-181c-5p. Importantly, SNHG1 could be induced by SP1 in BMSCs. CONCLUSIONS: Collectively, SP1-induced SNHG1 modulated SFRP1/Wnt/ß-catenin signaling pathway via sponging miR-181c-5p, thereby inhibiting osteoblast differentiation and angiogenesis while promoting osteoclast formation. Further, SNHG1 silence might provide a potential treatment for osteoporosis.

LncRNA SNHG1 protects SH-SY5Y cells from hypoxic injury through miR-140-5p/Bcl-XL axis.

Background: Hypoxic brain injury is one of the major causes of neurodevelopmental impairment and cardiovascular disability. LncRNA SNHG1 works as a critical factor in hypoxic induced injury, however, the potential mechanism is still not known well.Methods: The expression level of small nucleolar RNA host gene 1 (SNHG1) and miR-140-5p was detected by qRT-PCR. The western blot assay was performed to measure the level of Bcl-XL and apoptosis-related proteins. The target relationship between lncRNA SNHG1 and miR-140-5p, as well as miR-140-5p and Bcl-XL was detected by dual luciferase reporter gene assay. Cell apoptosis was assessed using Annexin V/PI staining by flow cytometry. Cell viability was analyzed by MTT assay.Results: Oxygen glucose deprivation (OGD) treatment inhibited SNHG1 and Bcl-XL expression and enhanced miR-140-5p expression. OGD treatment-induced cell viability inhibition, cell apoptosis promotion were partially abrogated when SH-SY5Y cells were transfected with pcDNA3.1-SNHG1 or miR-140-5p inhibitor. Moreover, luciferase reporter assay revealed that lncRNA SNHG1 bound directly to miR-140-5p, and miR-140-5p directly targeted Bcl-XL. The protective effect of SNHG1 overexpressing on cell apoptosis induced by OGD was attenuated after transfected with miR-140-5p mimic or sh-Bcl-XL in SH-SY5Y cells.Conclusion: LncRNA SNHG1-modulated miR-140-5p inhibition regulates Bcl-XL expression, thereby reducing cell apoptosis and recovering cell viability of SH-SY5Y cells. The results in this study provide novel insight into the mechanism of SNHG1 mediated signaling pathway during hypoxic brain injury.