Long non-coding RNA HIF1A-AS2 facilitates adipose-derived stem cells (ASCs) osteogenic differentiation through miR-665/IL6 axis via PI3K/Akt signaling pathway

Circular RNA-0072309 has antitumor influences in Hep3B cell line by targeting microRNA-665

Liver cancer is a malignant tumor that occurs in the liver and has a high mortality rate. We strived to detect the role and mechanism of circRNA-0072309 in liver cancer. Hep3B cell line was transfected with pc-circ and si-circ for viability, colony formation, apoptosis, migration, and invasion tests, which were individually performed by CCK-8, colony formation detection, flow cytometry assay, migration and invasion assays. What is more, the luciferase reporter assay was conducted to determine the target relationship between the circRNA-0072309 and microRNA (miR)-665. The expression of circRNA-0072309 was examined by qRT-PCR. The expression of proteins was examined via western blot. CircRNA-0072309 was lowly expressed in liver cancer tissues and positively associated with 5-year survival rate. The viability, colony formation, invasive and migratory ability were inhibited by abundant circRNA-0072309, which promoted cell apoptosis on the contrary. CircRNA-0072309 knockdown induced opposite effects, but could not affect apoptosis. Overexpressed miR-665 in tumor tissues was targeted and negatively controlled by circRNA-0072309. The PI3K/AKT and Wnt/β-catenin pathways were inhibited by abundant circRNA-0072309. miR-665 overexpression disturbed those effects derived from pc-circ. The circRNA-0072309 had antitumor influences in Hep3B cell line through targeting miR-665 relying on the deactivation of PI3K/AKT and Wnt/β-catenin pathways.

Epigenetics: Novel crucial approach for osteogenesis of mesenchymal stem cells

Bone has a robust regenerative potential, but its capacity to repair critical-sized bone defects is limited. In recent years, stem cells have attracted significant interest for their potential in tissue engineering. Applying mesenchymal stem cells (MSCs) for enhancing bone regeneration is a promising therapeutic strategy. However, maintaining optimal cell efficacy or viability of MSCs is limited by several factors. Epigenetic modification can cause changes in gene expression levels without changing its sequence, mainly including nucleic acids methylation, histone modification, and non-coding RNAs. This modification is believed to be one of the determinants of MSCs fate and differentiation. Understanding the epigenetic modification of MSCs can improve the activity and function of stem cells. This review summarizes recent advances in the epigenetic mechanisms of MSCs differentiation into osteoblast lineages. We expound that epigenetic modification of MSCs can be harnessed to treat bone defects and promote bone regeneration, providing potential therapeutic targets for bone-related diseases.

Downregulation of DNA methyltransferase-3a ameliorates the osteogenic differentiation ability of adipose-derived stem cells in diabetic osteoporosis via Wnt/β-catenin signaling pathway

Background

Diabetes-related osteoporosis (DOP) is a chronic disease caused by the high glucose environment that induces a metabolic disorder of osteocytes and osteoblast-associated mesenchymal stem cells. The processes of bone defect repair and regeneration become extremely difficult with DOP. Adipose-derived stem cells (ASCs), as seed cells in bone tissue engineering technology, provide a promising therapeutic approach for bone regeneration in DOP patients. The osteogenic ability of ASCs is lower in a DOP model than that of control ASCs. DNA methylation, as a mechanism of epigenetic regulation, may be involved in DNA methylation of various genes, thereby participating in biological behaviors of various cells. Emerging evidence suggests that increased DNA methylation levels are associated with activation of Wnt/β-catenin signaling pathway. The purpose of this study was to investigate the influence of the diabetic environment on the osteogenic potential of ASCs, to explore the role of DNA methylation on osteogenic differentiation of DOP-ASCs via Wnt/β-catenin signaling pathway, and to improve the osteogenic differentiation ability of ASCs with DOP.

Methods

DOP-ASCs and control ASCs were isolated from DOP C57BL/6 and control mice, respectively. The multipotency of DOP-ASCs was confirmed by Alizarin Red-S, Oil Red-O, and Alcian blue staining. Real-time polymerase chain reaction (RT-PCR), immunofluorescence, and western blotting were used to analyze changes in markers of osteogenic differentiation, DNA methylation, and Wnt/β-catenin signaling. Alizarin Red-S staining was also used to confirm changes in the osteogenic ability. DNMT small interfering RNA (siRNA), shRNA-Dnmt3a, and LVRNA-Dnmt3a were used to assess the role of Dnmt3a in osteogenic differentiation of control ASCs and DOP-ASCs. Micro-computed tomography, hematoxylin and eosin staining, and Masson staining were used to analyze changes in the osteogenic capability while downregulating Dnmt3a with lentivirus in DOP mice in vivo.

Results

The proliferative ability of DOP-ASCs was lower than that of control ASCs. DOP-ASCs showed a decrease in osteogenic differentiation capacity, lower Wnt/β-catenin signaling pathway activity, and a higher level of Dnmt3a than control ASCs. When Dnmt3a was downregulated by siRNA and shRNA, osteogenic-related factors Runt-related transcription factor 2 and osteopontin, and activity of Wnt/β-catenin signaling pathway were increased, which rescued the poor osteogenic potential of DOP-ASCs. When Dnmt3a was upregulated by LVRNA-Dnmt3a, the osteogenic ability was inhibited. The same results were obtained in vivo.

Conclusions

Dnmt3a silencing rescues the negative effects of DOP on ASCs and provides a possible approach for bone tissue regeneration in patients with diabetic osteoporosis.

Knockdown of PDX1 enhances the osteogenic differentiation of ADSCs partly via activation of the PI3K/Akt signaling pathway

Background

Osteoporosis (OP) is a systemic bone disease manifested as low bone mass, destruction of bone microstructure, increased bone fragility and fracture risk. The purpose of this study was to explore the role and mechanism of PDX1 for osteogenic differentiation of adipose derived stem cells (ADSCs).

Methods

GSE37329 dataset was retrieved from NCBI Gene Expression Omnibus (GEO) database and performed bioinformatic analyses. ADSCs were incubated with normal medium, osteogenic induction medium (OIM) and OIM+si-PDX1. Then, alkaline phosphatase (ALP) staining and Alizarin Red Staining (ARS) were performed to assess the role of PDX1 for osteogenesis of ADSCs. PI3K inhibitor, LY294002 was then added to further explore the mechanism of PDX1 for osteogenic differentiation of ADSCs. Western blot assay was used to assess the osteogenic-related markers. Graphpad software was used to perform statistically analysis.

Results

A total of 285 DEGs were obtained from analysis of the dataset GSE37329, of which 145 were upregulated and 140 were downregulated genes. These differentially expressed genes mainly enriched in cell differentiation and PI3K/Akt signaling pathway. Moreover, PDX1 was decreased in osteogenic induced ADSCs. Knockdown of PDX1 significantly increased osteogenic differentiation capacity and p-PI3K and p-Akt protein levels. Administration with LY294002 could partially reversed the promotion effects of si-PDX1.

Conclusion

In conclusion, knockdown of PDX1 promotes osteogenic differentiation of ADSCs through the PI3K/Akt signaling pathway.

Advancements in nucleic acids-based techniques for bone regeneration

The dynamic biology of bone involving an enormous magnitude of cellular interactions and signaling transduction provides ample biomolecular targets, which can be enhanced or repressed to mediate a rapid regeneration of the impaired bone tissue. The delivery of nucleic acids such as DNA and RNA can enhance the expression of osteogenic proteins. Members of the RNA interference pathway such as miRNA and siRNA can repress negative osteoblast differentiation regulators. Advances in nanomaterials have provided researchers with a plethora of delivery modules that can ensure proper transfection. Combining the nucleic acid carrying vectors with bone scaffolds has met with tremendous success in accomplishing bone formation. Recent years have witnessed the advent of CRISPR and DNA nanostructures in regenerative medicine. This review focuses on the delivery of nucleic acids and touches upon the prospect of CRISPR and DNA nanostructures for bone tissue engineering, emphasizing their potential in treating bone defects.

HIF1A-AS2 induces osimertinib resistance in lung adenocarcinoma patients by regulating the miR-146b-5p/IL-6/STAT3 axis

Although epidermal growth factor receptor tyrosine kinase inhibitors (TKIs) show efficacy in lung adenocarcinoma (LUAD) patients, TKI resistance inevitably develops, limiting long-term results. Thus, there is an urgent need to address drug resistance in LUAD. Long non-coding RNA (lncRNA) HIF1A-AS2 could be a critical mediator in the progression of various tumor types. We examined the function of HIF1A-AS2 in modifying tumor aggravation and osimertinib resistance in lung adenocarcinoma. Using clinical samples, we showed that HIF1A-AS2 was upregulated in LUAD specimens, predicting poorer overall survival and disease-free survival. HIF1A-AS2 silencing inhibited the proliferation, migration, and tumorigenesis of LUAD cells and therapeutic efficacy of osimertinib against tumor cells in vitro and in vivo. RNA precipitation assays, western blotting, luciferase assays, and rescue experiments demonstrated that HIF1A-AS2 sponged microRNA-146b-5p (miR-146b-5p), promoting interleukin-6 (IL-6) expression, activating the IL-6/STAT3 pathway, and leading to LUAD progression. miR-146b-5p and IL-6 levels were correlated with the prognosis of LUAD patients. Our results indicated that HIF1A-AS2 functions as an oncogenic factor in adenocarcinoma cells by targeting the miR-146b-5p/IL-6/STAT3 axis and may be a prognostic indicator of survival. Moreover, it can be a potential therapeutic target to enhance the efficacy of osimertinib in LUAD patients.

The role of hypoxia-induced long noncoding RNAs (lncRNAs) in tumorigenesis and metastasis

Long noncoding RNAs (lncRNAs) are noncoding RNAs with length greater than 200 nt. The biological roles and mechanisms mediated by lncRNAs have been extensively investigated. Hypoxia is a proven microenvironmental factor that promotes solid tumor metastasis. Epithelial-mesenchymal transition (EMT) is one of the major mechanisms induced by hypoxia to contribute to metastasis. Many lncRNAs have been shown to be induced by hypoxia and their roles have been delineated. In this review, we focus on the hypoxia-inducible lncRNAs that interact with protein/protein complex and chromatin/epigenetic factors, and the mechanisms that contribute to metastasis. The role of a recently discovered lncRNA RP11-390F4.3 in hypoxia-induced EMT is discussed. Whole genome approaches to delineating the association between lncRNAs and histone modifications are discussed. Other topics related to hypoxia-induced tumor progression but require further investigation are also mentioned. The clinical significance and treatment strategy targeted against lncRNAs are discussed. The review aims to identify suitable lncRNA targets that may provide feasible therapeutic venues for hypoxia-involved cancers.

lncRNA MEG8 is downregulated in osteoarthritis and regulates chondrocyte cell proliferation, apoptosis and inflammation

Long noncoding RNA (lncRNA) maternally expressed 8, small nucleolar RNA host gene (MEG8) has been widely reported for its pro-proliferative, anti-apoptotic and anti-inflammatory effects in diverse diseases. The aim of the present study was to investigate the effects and underlying mechanism of MEG8 on IL-1β-stimulated human osteoarthritis (OA) chondrocytes. C28/I2 chondrocytes were cultured under the stimulation of IL-1β to establish a cellular model of OA. Functional assays involving Cell Counting Kit-8 and flow cytometry were performed to determine proliferation and apoptosis in the cells. The protein expression levels of caspase-3 and inflammatory cytokines were detected using cell-based ELISA. The expression levels of PI3K/AKT pathway-related proteins were evaluated by western blotting. It was identified that MEG8 expression was increased in the cartilage of patients with OA and in IL-1β-treated C28/I2 cells. In C28/I2 cells, silencing of MEG8 expression noticeably triggered IL-1β-induced proliferation suppression, cell death and an inflammatory response. However, transfection with MEG8 displayed adverse effects. Furthermore, MEG8 overexpression prevented IL-1β-induced activation of the PI3K/AKT signaling pathway in C28/I2 cells. These data demonstrated that MEG8 exerted protective effects against IL-1β-induced apoptosis and inflammation of OA chondrocytes by regulating the PI3K/AKT signaling pathway. Thus, the present study demonstrates that MEG8 might be a promising target for the treatment of OA.

MiR-874-3p inhibits osteogenic differentiation of human periodontal ligament fibroblasts through regulating Wnt/β-catenin pathway

Background/purpose

Previous studies have shown that miR-874 is considered to be an important regulatory factor that participated in osteoclast differentiation. The role of miR-874-3p on osteoclast differentiation of human periodontal ligament fibroblast(hPDLF), however, is still unclear. This study was aimed to delve into the related molecular mechanism of miR-874-3p on hPDLF osteoclast differentiation.

Materials and methods

The qRT-PCR assays were applied to check miR-874-3p and WNT3A expression levels during the osteoclast differentiation of hPDLF. Alkaline phosphatase (ALP) activity assays and alizarin red staining assays were applied to appraise the degree of hPDLF osteoclast differentiation. Bioinformatics method and dual-luciferase reporter assay were employed together to anticipate and certify the interaction between miR-874-3p and WNT3A. Western blot assay was applied to examine the β-catenin and WNT3A expression in transfected hPDLF.

Results

In this study, the results indicated that the expression level of miR-874-3p was gradually down-regulated while WNT3A was concomitantly increased during osteogenic differentiation of hPDLF. Overexpression or knockdown of miR-874-3p would inhibit or promote WNT3A and β-catenin protein expression as well as osteogenic differentiation of hPDLF, respectively. Further research indicated that miR-874-3p directly regulated WNT3A expression via coupling with the 3′-UTR of WNT3A. Finally, upregulation of WNT3A expression levels rescues β-catenin expression levels and osteogenic differentiation of hPDLF inhibited by miR-874-3p was explored.

Conclusion

MiR-874-3p inhibits osteogenic differentiation of hPDLF through regulating Wnt/β-catenin pathway.

LINC00370 modulates miR-222-3p-RGS4 axis to protect against osteoporosis progression

BACKGROUND

We aimed to determine the role of the LINC00370/miR-222-3p/RGS4 axis in modulating the process of adipose-derived stem cell (ADSC) osteogenic differentiation.

METHODS

We first evaluated the differential expression of LINC00370, miR-222-3p and RGS4 between normal and osteogenically induced ADSCs. Moreover, we transfected ADSCs with LINC00370 siRNA and an miR-222-3p inhibitor to determine the role of LINC00370 in modulating the process of ADSC osteogenic differentiation. Finally, we analyzed the dual-luciferase reporter gene to identify the relationship between LINC00370 and miR-222-3p. We first created osteoporotic rat models by ovariectomy (OVX) and treated with pcDNA-LINC00370. HE and immunohistochemical staining of OCN were performed to assess the changes in bone microarchitecture.

RESULTS

LINC00370 and RGS4 expression was remarkably upregulated in the osteogenic ADSC group compared with the normal medium group. On the other hand, miR-222-3p expression was remarkably decreased in the osteogenic group compared with the normal medium group. Knockdown of LINC00370 reduced the osteogenic differentiation of ADSCs. Moreover, the inhibitor of miR-222-3p partially reversed the reduction of osteogenic differentiation by LINC00370 knockdown. Knockdown of LINC00370 reduced the expression of p-Akt and p-PI3K. The inhibitor of miR-222-3p partially reversed the reduction of the expression of p-Akt and p-PI3K by LINC00370 knockdown. A dual luciferase reporter assay indicated that LINC00370 can directly bind miR-222-3p. LINC00370 suppressed OP progression in OVX and partially upregulated OCN protein expression.

CONCLUSION

Collectively, the above results confirm that LINC00370 promotes the process of ADSC osteogenic differentiation via the miR-222-3p/RGS4 axis. Moreover, LINC00370 could protect against OVX-induced OP.

Cornuside I promoted osteogenic differentiation of bone mesenchymal stem cells through PI3K/Akt signaling pathway

Background

Osteoporosis is a common disease closely associated with aging. In this study, we aimed to investigate the role of Cornuside I in promoting osteogenic differentiation of bone mesenchymal stem cells (BMSCs) and the potential mechanism.

Methods

BMSCs were isolated and treated with different concentrations of Cornuside I (0, 10, 30, 60 μM). Cell proliferation was analyzed by Cell Counting Kit-8 (CCK-8) assay. RNA sequencing was performed on the isolated BMSCs with control and Cornuside I treatment. Differentially expressed genes were obtained by the R software. Alkaline phosphatase (ALP) staining and Alizarin Red Staining (ARS) were performed to assess the osteogenic capacity of the NEO. qRT-PCR and western blot were used to detect the expression of osteoblast markers.

Results

Cornuside I treatment significantly improved BMSC proliferation. The optimal dose of Cornuside I was 30 μM (P < 0.05). Cornuside I dose dependently increased the ALP activity and calcium deposition than control group (P < 0.05). A total of 704 differentially expressed genes were identified between Cornuside I and normal BMSCs. Cornuside I significantly increased the PI3K and Akt expression. Moreover, the promotion effects of Cornuside I on osteogenic differentiation of BMSCs were partially blocked by PI3K/Akt inhibitor, LY294002.

Conclusion

Cornuside I plays a positive role in promoting osteogenic differentiation of BMSCs, which was related with activation of PI3K/Akt signaling pathway.

Circulating lncRNAs HIF1A-AS2 and LINLK-A: Role and Relation to Hypoxia-Inducible Factor-1α in Cerebral Stroke Patients

Long noncoding RNAs (lncRNAs) have been recently recognized as key players of gene expression in cerebral pathogenesis. Thus, their potential use in stroke diagnosis, prognosis, and therapy is actively pursued. Due to the complexity of the disease, identifying stroke-specific lncRNAs remains a challenge. This study investigated the expression of lncRNAs HIF1A-AS2 and LINK-A, and their target gene hypoxia-inducible factor-1 (HIF-1) in Egyptian stroke patients. It also aimed to determine the molecular mechanism implicated in the disease. A total of 75 stroke patients were divided into three clinical subgroups, besides 25 healthy controls of age-matched and sex-matched. Remarkable upregulation of lncRNA HIF1A-AS2 and HIF1-α along with a downregulation of lncRNA LINK-A was noticed in all stroke groups relative to controls. Serum levels of phosphatidylinositol 3-kinase (PI3K), phosphorylated-Akt (p-Akt), vascular endothelial growth factor (VEGF), and angiopoietin-1 (ANG1) as well as their receptors, malondialdehyde (MDA), and total antioxidant capacity (TAC) were significantly increased, whereas brain-derived neurotrophic factor (BDNF) levels were significantly decreased particularly in hemorrhagic stroke versus ischemic groups. Eventually, these findings support the role of lncRNAs HIF1A-AS2 and LINK-A as well as HIF1-α in activation of angiogenesis, neovascularization, and better prognosis of stroke, especially the hemorrhagic type.

Long noncoding RNA AC092155 facilitates osteogenic differentiation of adipose-derived stem cells through the miR-143-3p/STMN1 axis

BACKGROUND

Numerous studies have demonstrated that long noncoding RNAs (lncRNAs) induce osteogenesis in adipose-derived stem cells (ADSCs). This study aimed to explore the role of lncRNAs AC092155 in promoting osteogenic differentiation of ADSCs.

METHODS

MicroRNA (miRNA) and lncRNA sequencing were performed in ADSCs that underwent normal or osteogenic induction. Differentially expressed miRNAs and lncRNAs were identified using R software. The relative expression levels of lncRNA AC092155, miR-143-3p, and STMN1 during the process of osteogenic induction were determined by real-time polymerase chain reaction (RT-PCR). ADSCs were then transfected with agomiR-143-3p and pcDNA3.1-sh-lncRNA AC092155. Alkaline phosphatase (ALP) and alizarin red staining (ARS) were used to confirm the regulatory function of the lncRNA AC092155/miR-143-3p/STMN1 axis in osteogenic differentiation of ADSCs.

RESULTS

lncRNA AC092155 was significantly upregulated in ADSCs following induction in the osteogenic medium. lncRNA AC092155 and STMN1 mimics increase the markers of osteogenic differentiation in the early and late phases, which was reflected in increased ALP activity as well as the higher deposition of calcium nodules. An miR-143-3p mimic showed the opposite effect. Luciferase reporter gene analysis demonstrated that lncRNA AC092155 directly targets miR-143-3p. Moreover, the lncRNA AC092155/miR-143-3p/STMN1 regulatory axis was found to activate the Wnt/β-catenin signaling pathway.

CONCLUSIONS

lncRNA AC092155 contributes to the osteogenic differentiation of ADSCs. The lncRNA AC092155/miR-143-3p/STMN1 axis may be a new therapeutic target for bone-related diseases.

PAX8-AS1 knockdown facilitates cell growth and inactivates autophagy in osteoblasts via the miR-1252-5p/GNB1 axis in osteoporosis

Osteoporosis (OP) is the most common systematic bone disorder among elderly individuals worldwide. Long noncoding RNAs (lncRNAs) are involved in biological processes in various human diseases. It has been previously revealed that PAX8 antisense RNA 1 (PAX8-AS1) is upregulated in OP. However, its molecular mechanism in OP remains unclear. Therefore, we specifically designed this study to determine the specific role of PAX8-AS1 in OP. We first established a rat model of OP and then detected PAX8-AS1 expression in the rats with RT-qPCR. Next, to explore the biological function of PAX8-AS1 in osteoblasts, in vitro experiments, such as Cell Counting Kit-8 (CCK-8) assays, flow cytometry, western blotting and immunofluorescence (IF) staining, were conducted. Subsequently, we performed bioinformatic analysis and luciferase reporter assays to predict and identify the relationships between microRNA 1252-5p (miR-1252-5p) and both PAX8-AS1 and G protein subunit beta 1 (GNB1). Additionally, rescue assays in osteoblasts clarified the regulatory network of the PAX8-AS1/miR-1252-5p/GNB1 axis. Finally, in vivo loss-of-function studies verified the role of PAX8-AS1 in OP progression. The results illustrated that PAX8-AS1 was upregulated in the proximal tibia of OP rats. PAX8-AS1 silencing promoted the viability and inhibited the apoptosis and autophagy of osteoblasts. PAX8-AS1 interacted with miR-1252-5p. GNB1 was negatively regulated by miR-1252-5p. In addition, the impacts of PAX8-AS1 knockdown on osteoblasts were counteracted by GNB1 overexpression. PAX8-AS1 depletion suppressed OP progression by inhibiting apoptosis and autophagy in osteoblasts. In summary, PAX8-AS1 suppressed the viability and activated the autophagy of osteoblasts via the miR-1252-5p/GNB1 axis in OP.

Exploring the Pharmacological Mechanism of Duhuo Jisheng Decoction in Treating Osteoporosis Based on Network Pharmacology

Objective

The purpose of this work is to study the mechanism of action of Duhuo Jisheng Decoction (DHJSD) in the treatment of osteoporosis based on the methods of bioinformatics and network pharmacology.

Methods

In this study, the active compounds of each medicinal ingredient of DHJSD and their corresponding targets were obtained from TCMSP database. Osteoporosis was treated as search query in GeneCards, MalaCards, DisGeNET, Therapeutic Target Database (TTD), Comparative Toxicogenomics Database (CTD), and OMIM databases to obtain disease-related genes. The overlapping targets of DHJSD and osteoporosis were identified, and then GO and KEGG enrichment analysis were performed. Cytoscape was employed to construct DHJSD-compounds-target genes-osteoporosis network and protein-protein interaction (PPI) network. CytoHubba was utilized to select the hub genes. The activities of binding of hub genes and key components were confirmed by molecular docking.

Results

174 active compounds and their 205 related potential targets were identified in DHJSD for the treatment of osteoporosis, including 10 hub genes (AKT1, ALB, IL6, MAPK3, VEGFA, JUN, CASP3, EGFR, MYC, and EGF). Pathway enrichment analysis of target proteins indicated that osteoclast differentiation, AGE-RAGE signaling pathway in diabetic complications, Wnt signaling pathway, MAPK signaling pathway, PI3K-Akt signaling pathway, JAK-STAT signaling pathway, calcium signaling pathway, and TNF signaling pathway were the specifically major pathways regulated by DHJSD against osteoporosis. Further verification based on molecular docking results showed that the small molecule compounds (Quercetin, Kaempferol, Beta-sitosterol, Beta-carotene, and Formononetin) contained in DHJSD generally have excellent binding affinity to the macromolecular target proteins encoded by the top 10 genes.

Conclusion

This study reveals the characteristics of multi-component, multi-target, and multi-pathway of DHJSD against osteoporosis and provides novel insights for verifying the mechanism of DHJSD in the treatment of osteoporosis.

Integrated analysis of miRNA and mRNA transcriptomic reveals antler growth regulatory network

The growth of antler is driven by endochondral ossification in the growth center of the apical region. Antler grows faster than cancer tissues, but it can be stably regulated and regenerated periodically. To elucidate the molecular mechanisms of how antler grows rapidly without carcinogenesis, in this study, we used RNA-seq technology to evaluate the changes of miRNA and mRNA profiles in antler at four different developmental stages, including 15, 60, 90, and 110 days. We identified a total of 55004 unigenes and 246 miRNAs of which, 10182, 13258, 10740 differentially expressed (DE) unigenes and 35, 53, 27 DE miRNAs were identified in 60-day vs. 15-day, 90-day vs. 60-day, and 110-day vs. 90-day. GO and KEGG pathway analysis indicated that DE unigenes and DE miRNA were mainly associated with chondrogenesis, osteogenesis and inhibition of oncogenesis, that were closely related to antler growth. The interaction networks of mRNA-mRNA and miRNA-mRNA related to chondrogenesis, osteogenesis and inhibition of oncogenesis of antler were constructed. The results indicated that mRNAs (COL2A1, SOX9, WWP2, FGFR1, SPARC, LOX, etc.) and miRNAs (miR-145, miR-199a-3p, miR-140, miR-199a-5p, etc.) might have key roles in chondrogenesis and osteogenesis of antler. As well as mRNA (TP53, Tpm3 and ATP1A1, etc.) and miRNA (miR-106a, miR-145, miR-1260b and miR-2898, etc.) might play important roles in inhibiting the carcinogenesis of antler. In summary, we constructed the mRNA-mRNA and miRNA-mRNA regulatory networks related to chondrogenesis, osteogenesis and inhibition of oncogenesis of antler, and identified key candidate mRNAs and miRNAs among them. Further developments and validations may provide a reference for in-depth analysis of the molecular mechanism of antler growth without carcinogenesis.

QingYan formula extracts protect against postmenopausal osteoporosis in ovariectomized rat model via active ER-dependent MEK/ERK and PI3K/Akt signal pathways

ETHNOPHARMACOLOGICAL RELEVANCE

QingYan Formula has been traditionally used to tonify kidney and benefit essence, and QingYan Formula 70% ethanol extracts (QYFE) showed estrogen-like effect on reproductive system in our previous studies. However, there were no reports of QYFE on bone.

AIM OF THE STUDY

This study offered preliminary insight of QYFE into the pharmacodynamics and mechanism of anti-bone osteoporosis in ovariectomized rats.

MATERIALS AND METHODS

OVX rats were orally administrated QYFE or estradiol valerate (EV) for 12 weeks. We investigated the pharmacodynamic effects of QYFE on anti-bone loss in OVX rats, and also investigated the role of QYFE in promoting osteogenesis and inhibiting osteoclast differentiation.

RESULTS

QYFE administration significantly reduced the degree of high bone turnover, dose-dependently repaired the damaged microstructure of trabecular and cortical bone by Hematoxylin-Eosin (HE) staining and micro-computed tomography (micro-CT), and reduced the number of femur osteoclasts by TRAP staining. QYFE enhanced the proliferation and activity of alkaline phosphatase (ALP), the phosphorylation levels of extracellular regulated kinase (ERK) and Akt in MG-63 cells, which was inhibited by ICI 182 780. Moreover, in RAW264.7 cells, QYFE inhibited osteoclasts differentiation, reduced the number of osteoclasts, decreased the activity of TRAP enzyme during formation, down-regulated the protein expression of p-ERK inhibited by ICI 182 780 and p-Akt not inhibited by ICI 182 780.

CONCLUSION

This experiment demonstrated that QYFE had a definite anti-bone loss effect and had potential effect on postmenopausal osteoporosis. The molecular mechanism was related to the activation of estrogen receptor (ER)-dependent mitogen-activated protein kinase kinase (MEK)/ERK and phosphoinositide 3-kinase (PI3K)/Akt signal pathways in osteoblast, down-regulation protein expressions of ER-dependent p-ERK and ER-independent p-Akt in osteoclast.

The miRNA: a small but powerful RNA for COVID-19

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a severe and rapidly evolving epidemic. Now, although a few drugs and vaccines have been proved for its treatment and prevention, little systematic comments are made to explain its susceptibility to humans. A few scattered studies used bioinformatics methods to explore the role of microRNA (miRNA) in COVID-19 infection. Combining these timely reports and previous studies about virus and miRNA, we comb through the available clues and seemingly make the perspective reasonable that the COVID-19 cleverly exploits the interplay between the small miRNA and other biomolecules to avoid being effectively recognized and attacked from host immune protection as well to deactivate functional genes that are crucial for immune system. In detail, SARS-CoV-2 can be regarded as a sponge to adsorb host immune-related miRNA, which forces host fall into dysfunction status of immune system. Besides, SARS-CoV-2 encodes its own miRNAs, which can enter host cell and are not perceived by the host's immune system, subsequently targeting host function genes to cause illnesses. Therefore, this article presents a reasonable viewpoint that the miRNA-based interplays between the host and SARS-CoV-2 may be the primary cause that SARS-CoV-2 accesses and attacks the host cells.

MicroRNA-665 Regulates Cell Proliferation and Apoptosis of Vascular Smooth Muscle Cells by Targeting TGFBR1

Coronary artery disease (CAD) is one of the heavy health burdens worldwide. Aberrant proliferation of vascular smooth muscle cells (VSMCs) contributes to the occurrence and development of CAD. This study aimed at exploring differentially expressed microRNAs (miRNAs) and their regulatory mechanisms in the development of CAD.The miRNA expression profile of GSE28858 was obtained from the Gene Expression Omnibus database. Differentially expressed miRNAs (DEmiRNAs) between CAD and healthy control samples were analyzed using limma package in R. Target genes of DEmiRNAs were predicted, and a miRNA-target gene network was constructed. The relationship between miR-665 and transforming growth factor beta receptor 1 (TGFBR1) was selected for further analysis. The interaction between miR-665 and TGFBR1 was confirmed by dual luciferase reporter assay. Effects of miR-665 on cell viability and apoptosis of VSMCs were evaluated by cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. Besides, western blot assays for BCL2L11 and caspase 3 were also conducted.A total of 38 upregulated miRNAs and 28 downregulated miRNAs were identified. The expression level of miR-665 was significantly downregulated in patients with CAD. TGFBR1 was proved to be a target gene of miR-665. Besides, ectopic expression of miR-665 obviously inhibited VSMC growth and promoted VSMC apoptosis. TGFBR1 overexpression in VSMCs transfected with miR-665 mimic could restore the effect of miR-665 on the proliferation and apoptosis of VSMCs.MiR-665 might participate in the proliferation and apoptosis of VSMCs by targeting TGFBR1.

LncRNA HIF1A-AS2 accelerates malignant phenotypes of renal carcinoma by modulating miR-30a-5p/SOX4 axis as a ceRNA

OBJECTIVE

Several reports have proposed that lncRNAs, as potential biomarkers, participate in the progression and growth of malignant tumors. HIF1A-AS2 is a novel lncRNA and potential biomarker, involved in the genesis and development of carcinomas. However, the molecular mechanism of HIF1A-AS2 in renal carcinoma is unclear.

METHODS

The relative expression levels of HIF1A-AS2 and miR-30a-5p were detected using RT-qPCR in renal carcinoma tissues and cell lines. Using loss-of-function and overexpression, the biological effects of HIF1A-AS2 and miR-30a-5p in kidney carcinoma progression were characterized. Dual luciferase reporter gene analysis and Western blot were used to detect the potential mechanism of HIF1A-AS2 in renal carcinomas.

RESULTS

HIF1A-AS2 was upregulated in kidney carcinoma tissues when compared with para-carcinoma tissues (P < 0.05). In addition, tumor size, tumor node mestastasis stage and differentiation were identified as being closely associated with HIF1A-AS2 expression (P < 0.05). Knockdown or overexpression of HIF1A-AS2 either restrained or promoted the malignant phenotype and WNT/β-catenin signaling in renal carcinoma cells (P < 0.05). MiR-30a-5p was downregulated in renal cancers and partially reversed HIF1A-AS2 functions in malignant renal tumor cells. HIF1A-AS2 acted as a microRNA sponge that actively regulated the relative expression of SOX4 in sponging miR-30a-5p and subsequently increased the malignant phenotypes of renal carcinomas. HIF1A-AS2 showed a carcinogenic effect and miR-30a-5p acted as an antagonist of the anti-oncogene effects in the pathogenesis of renal carcinomas.

CONCLUSIONS

The HIF1A-AS2-miR-30a-5p-SOX4 axis was associated with the malignant progression and development of renal carcinoma. The relative expression of HIF1A-AS2 was negatively correlated with the expression of miR-30a-5p, and was closely correlated with SOX4 mRNA levels in renal cancers.

The HIF-1α antisense long non-coding RNA drives a positive feedback loop of HIF-1α mediated transactivation and glycolysis

Hypoxia-inducible factor-1 (HIF-1) is a master driver of glucose metabolism in cancer cells. Here, we demonstrate that a HIF-1α anti-sense lncRNA, HIFAL, is essential for maintaining and enhancing HIF-1α-mediated transactivation and glycolysis. Mechanistically, HIFAL recruits prolyl hydroxylase 3 (PHD3) to pyruvate kinase 2 (PKM2) to induce its prolyl hydroxylation and introduces the PKM2/PHD3 complex into the nucleus via binding with heterogeneous nuclear ribonucleoprotein F (hnRNPF) to enhance HIF-1α transactivation. Reciprocally, HIF-1α induces HIFAL transcription, which forms a positive feed-forward loop to maintain the transactivation activity of HIF-1α. Clinically, high HIFAL expression is associated with aggressive breast cancer phenotype and poor patient outcome. Furthermore, HIFAL overexpression promotes tumor growth in vivo, while targeting both HIFAL and HIF-1α significantly reduces their effect on cancer growth. Overall, our results indicate a critical regulatory role of HIFAL in HIF-1α-driven transactivation and glycolysis, identifying HIFAL as a therapeutic target for cancer treatment.

The role of microRNAs in bone development

Epigenetic regulation is critical for proper bone development. Evidence from a large body of published literature informs us that microRNAs (miRNAs) are important epigenetic factors that control many aspects of bone development, homeostasis, and repair processes. These small non-coding RNAs function at the post-transcriptional level to suppress expression of specific target genes. Many target genes may be affected by one miRNA resulting in alteration in cellular pathways and networks. Therefore, changes in levels or activity of a specific miRNA (e.g. via genetic mutations, disease scenarios, or by over-expression or inhibition strategies in vitro or in vivo) can lead to substantial changes in cell processes including proliferation, metabolism, apoptosis and differentiation. In this review, Section 1 briefly covers general background information on processes that control bone development as well as the biogenesis and function of miRNAs. In Section 2, we discuss the importance of miRNAs in skeletal development based on findings from in vivo mouse models and human clinical reports. Section 3 focuses on describing more recent data from the last three years related to miRNA regulation of osteoblast differentiation in vitro. Some of these studies also involve utilization of an in vivo rodent model to study the effects of miRNA modulation in scenarios of osteoporosis, bone repair or ectopic bone formation. In Section 4, we provide some recent information from studies analyzing the potential of miRNA-mediated crosstalk in bone and how exosomes containing miRNAs from one bone cell may affect the differentiation or function of another bone cell type. We then conclude by summarizing where the field currently stands with respect to miRNA-mediated regulation of osteogenesis and how information gained from developmental processes can be instructive in identifying potential therapeutic miRNA targets for the treatment of certain bone conditions.

Recent Advances of Osterix Transcription Factor in Osteoblast Differentiation and Bone Formation

With increasing life expectations, more and more patients suffer from fractures either induced by intensive sports or other bone-related diseases. The balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption is the basis for maintaining bone health. Osterix (Osx) has long been known to be an essential transcription factor for the osteoblast differentiation and bone mineralization. Emerging evidence suggests that Osx not only plays an important role in intramembranous bone formation, but also affects endochondral ossification by participating in the terminal cartilage differentiation. Given its essentiality in skeletal development and bone formation, Osx has become a new research hotspot in recent years. In this review, we focus on the progress of Osx's function and its regulation in osteoblast differentiation and bone mass. And the potential role of Osx in developing new therapeutic strategies for osteolytic diseases was discussed.

Inhibition of long noncoding RNA HIF1A-AS2 confers protection against atherosclerosis via ATF2 downregulation

Introduction

In atherosclerotic lesions, extensive inflammation of the vessel wall contributes to plaque instability. Long noncoding RNAs (lncRNAs) play important roles in diverse biological processes in atherosclerosis.

Objectives

Here, we aim to identify the functional role and regulatory mechanisms of lncRNA hypoxia-inducible factor 1 alpha-antisense RNA 2 (HIF1A-AS2) in atherosclerotic inflammation.

Methods

An atherosclerotic mouse model was induced in ApoE-/- mice by high fat diet (HFD). Endothelial cells (ECs), human aortic smooth muscle cells (SMCs) or human coronary artery endothelial cells (HCAECs) were exposed to ox-LDL to develop the in vitro model. The effects of lncRNA HIF1A-AS2 on inflammation were evaluated by determining levels of inflammatory factors tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) and levels of adhesion molecules vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and macrophage cationic peptide 1 (MCP-1).

Results

It was established that lncRNA HIF1A-AS2 and ATF2 were highly expressed in atherosclerotic ApoE-/- mice. Downregulating lncRNA HIF1A-AS2 in ox-LDL-exposed ECs, SMCs and HCAECs inhibited inflammation by reducing levels of pro-inflammatory factors and adhesion molecules. LncRNA HIF1A-AS2 bound to the transcription factor USF1 to elevate ATF2 expression. USF1 overexpression counteracted the suppressive effect of lncRNA HIF1A-AS2 silencing on ox-LDL-induced inflammation. Knockdown of lncRNA HIF1A-AS2 or ATF2 could also attenuate inflammation in atherosclerotic mice. Collectively, the present study demonstrates that downregulation of lncRNA HIF1A-AS2 represses the binding of USF1 to the ATF2 promoter region and then inhibits ATF2 expression, thereby suppressing atherosclerotic inflammation.

Conclusion

This study suggests lncRNA HIF1A-AS2 as an promising therapeutic target for atherosclerosis.

SNHG5/miR-582-5p/RUNX3 feedback loop regulates osteogenic differentiation and apoptosis of bone marrow mesenchymal stem cells

Osteoporosis is one of the most prevailing orthopedic diseases that causes a heavy burden on public health. Given that bone marrow-derived mesenchymal stem cells (BMSCs) are of immense importance in osteoporosis development, it is necessary to expound the mechanisms underlying BMSC osteoblastic differentiation. Although mounting research works have investigated the role of small nucleolar RNA host gene 5 (SNHG5) in various diseases, elucidations on its function in osteoporosis are still scarce. It was observed that SNHG5 and RUNX family transcription factor 3 (RUNX3) were remarkably elevated during osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). Further, we disclosed that the silencing of SNHG5 suppressed osteogenic differentiation and induced apoptosis of hBMSCs. What's more, SNHG5 acted as a competing endogenous RNA to affect RUNX3 expression via competitively binding with microRNA (miR)-582-5p. RUNX3 was also confirmed to simulate the transcriptional activation of SNHG5. Finally, our findings manifested that the positive feedback loop of SNHG5/miR-582-5p/RUNX3 executed the promoting role in the development of osteoporosis, which shed light on specific molecular mechanism governing SNHG5 in osteogenic differentiation and apoptosis of hBMSCs and indicated that SNHG5 may represent a novel target for the improvement of osteoporosis therapy.

Identification of potential specific biomarkers and key signaling pathways between osteogenic and adipogenic differentiation of hBMSCs for osteoporosis therapy

Background

The differentiation of bone mesenchymal stem cells (BMSCs) into adipogenesis (AD) rather than osteogenesis (OS) is an important pathological feature of osteoporosis. Illuminating the detailed mechanisms of the differentiation of BMSCs into OS and AD would contribute to the interpretation of osteoporosis pathology.

Methods

To identify the regulated mechanism in lineage commitment of the BMSCs into OS and AD in the early stages, the gene expression profiles with temporal series were downloaded to reveal the distinct fates when BMSCs adopt a committed lineage. For both OS and AD lineages, the profiles of days 2–4 were compared with day 0 to screen the differentially expressed genes (DEGs), respectively. Next, the functional enrichment analysis was utilized to find out the biological function, and protein-protein interaction network to predict the central genes. Finally, experiments were performed to verify our finding.

Results

FoxO signaling pathway with central genes like FoxO3, IL6, and CAT is the crucial mechanism of OS, while Rap1 signaling pathway of VEGFA and FGF2 enrichment is more significant for AD. Besides, PI3K-Akt signaling pathway might serve as the latent mechanism about the initiation of differentiation of BMSCs into multiple lineages.

Conclusion

Above hub genes and early-responder signaling pathways control osteogenic and adipogenic fates of BMSCs, which maybe mechanistic models clarifying the changes of bone metabolism in the clinical progress of osteoporosis. The findings provide a crucial reference for the prevention and therapy of osteoporosis.

Long Noncoding RNA HIF1A-AS2 Promotes Non-Small Cell Lung Cancer Progression by the miR-153-5p/S100A14 Axis

Background

Long noncoding RNA (lncRNA) plays a critical role in initiating lung cancer. This study aims to research the function and mechanism of lncRNA HIF1A-AS2 in regulating non-small cell lung cancer (NSCLC) progression.

Methods

qRT-PCR was used to analyze gene expression. The CCK-8 assay was performed to detect cell proliferation. The Transwell assay was conducted to examine cell migration and invasion. A Caspase3 activity detection kit was utilized to analyze apoptosis. The luciferase reporter assay was carried out to research interactions of HIF1A-AS2, miR-153-5p and S100A14.

Results

HIF1A-AS2 expression was raised in NSCLC tissues and cell lines. The HIF1A-AS2 level was increased in advanced NSCLC tumor tissues. High HIF1A-AS2 expression was related to poor prognosis. HIF1A-AS2 knockdown decreased proliferation, migration and invasion while promoting apoptosis. HIF1A-AS2 was the sponge for miR-153-5p, and miR-153-5p targeted S100A14. HIF1A-AS2 promoted S100A14 expression through regulating miR-153-5p.

Conclusion

The HIF1A-AS2/miR-153-5p/S100A14 axis plays a crucial role in promoting NSCLC progression.

circRNA Expression Profile in Dental Pulp Stem Cells during Odontogenic Differentiation

Introduction

Odontogenic differentiation of human dental pulp stem cells (hDPSCs) is a key step of pulp regeneration. Recent studies showed that circular RNAs (circRNAs) have many biological functions and that competing endogenous RNA (ceRNA) is their most common mechanism of action. However, the role of circRNAs in hDPSCs during odontogenesis is still unclear.

Methods

Isolated hDPSCs were cultured in essential and odontogenic medium. Total RNA was extracted after 14 days of culture, and then, microarray analysis was performed to measure the differential expressions of circRNAs. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was then performed to validate the microarray results. Based on microarray data from this study and available in the database, a ceRNA network was constructed to investigate the potential function of circRNAs during odontogenesis. In addition, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to investigate the potential correlation between signaling pathways and circRNAs. In addition, qRT-PCR and Western blot analysis were used to explore the function of hsa_circRNA_104101.

Results

We found 43 upregulated circRNAs and 144 downregulated circRNAs during the odontogenic differentiation process (fold change > 1.5 and <-1.5, respectively; P < 0.05). qRT-PCR results were in agreement with the microarray results. Bioinformatic analysis revealed that the Wnt signaling pathway and the TGF-β signaling pathway, as well as the other pathways associated with odontogenic differentiation, were correlated to the differentially expressed circRNAs. hsa_circRNA_104101 was proved to promote the odontogenic differentiation of hDPSCs.

Conclusion

This study reported 187 circRNAs that were differentially expressed in hDPSCs during odontogenic differentiation. Bioinformatic analysis of the expression data suggested that circRNA-miRNA-mRNA networks might act as a crucial mechanism for hDPSC odontogenic differentiation, providing a theoretical foundation for the study of pulp regeneration regulation by circRNAs.

Long non-coding RNA MIR22HG promotes osteogenic differentiation of bone marrow mesenchymal stem cells via PTEN/ AKT pathway

Osteoporosis is a prevalent metabolic bone disease characterized by low bone mineral density and degenerative disorders of bone tissues. Previous studies showed the abnormal osteogenic differentiation of endogenous bone marrow mesenchymal stem cells (BMSCs) contributes to the development of osteoporosis. However, the underlying mechanisms by which BMSCs undergo osteogenic differentiation remain largely unexplored. Recently, long non-coding RNAs have been discovered to play important roles in regulating BMSC osteogenesis. In this study, we first showed MIR22HG, which has been demonstrated to be involved in the progression of several cancer types, played an important role in regulating BMSC osteogenesis. We found the expression of MIR22HG was significantly decreased in mouse BMSCs from the osteoporotic mice and it was upregulated during the osteogenic differentiation of human BMSCs. Overexpression of MIR22HG in human BMSCs enhanced osteogenic differentiation, whereas MIR22HG knockdown inhibited osteogenic differentiation both in vitro and in vivo. Mechanistically, MIR22HG promoted osteogenic differentiation by downregulating phosphatase and tensin homolog (PTEN) and therefore activating AKT signaling. Moreover, we found MIR22HG overexpression promoted osteoclastogenesis of RAW264.7 cells, which indicated that MIR22HG played a significant role in bone metabolism and could be a therapeutic target for osteoporosis and other bone-related diseases.

FGF2-induced PI3K/Akt signaling evokes greater proliferation and adipogenic differentiation of human adipose stem cells from breast than from abdomen or thigh

In this study, human adipose stem cells were isolated from subcutaneous fat in the thigh (htASCs), abdomen (haASCs) and breast (hbASCs). Flow cytometry was used to detect cell surface markers, and an enzyme-linked immunosorbent assay was used to detect paracrine activity. Paracrine gene expression in the three cell types was examined using real-time qPCR, and adipogenic ability was assessed using Oil Red O staining. RNA from third-passage haASCs and hbASCs was sequenced. The results showed that the differentiation potential marker markers CD49d and CD54 were similar across hbASCs from 10 subjects. The hbASCs showed higher colony forming ability and expression of fibroblast growth factor-2, tissue inhibitor of metalloproteinase-1 and stromal cell derived factor-1 than htASCs and haASCs. Stimulating hbASCs with FGF2 promoted adipogenic differentiation, while treating the cells with the PI3K inhibitor LY294002 inhibited differentiation. These results suggest that the PI3K/Akt signaling pathway can promote proliferation and adipogenic differentiation of adipose stem cells, and that activation of this pathway by FGF2 may explain why hbASCs show greater proliferation and adipogenic differentiation than haASCs and htASCs.

Adipogenesis, Osteogenesis, and Chondrogenesis of Human Mesenchymal Stem/Stromal Cells: A Comparative Transcriptome Approach

Adipogenesis, osteogenesis and chondrogenesis of human mesenchymal stem/stromal cells (MSC) are complex and highly regulated processes. Over the years, several studies have focused on understanding the mechanisms involved in the MSC commitment to the osteogenic, adipogenic and/or chondrogenic phenotypes. High-throughput methodologies have been used to investigate the gene expression profile during differentiation. Association of data analysis of mRNAs, microRNAs, circular RNAs and long non-coding RNAs, obtained at different time points over these processes, are important to depict the complexity of differentiation. This review will discuss the results that were highlighted in transcriptome analyses of MSC undergoing adipogenic, osteogenic and chondrogenic differentiation. The focus is to shed light on key molecules, main signaling pathways and biological processes related to different time points of adipogenesis, osteogenesis and chondrogenesis.

Altered Long Noncoding RNA Expression Profile in Multiple Myeloma Patients with Bisphosphonate-Induced Osteonecrosis of the Jaw

Bisphosphonates (BPs) are inhibitors of osteoclast-mediated bone resorption used for the treatment of multiple myeloma (MM) patients with osteolytic lesions. Bisphosphonate-induced osteonecrosis of the jaw (BONJ) is an infrequent drug-caused adverse event of these agents. Long noncoding RNAs (lncRNAs) are a set of more than 200 base pairs, noncoding RNA molecules, which are critical posttranscriptional regulators of gene expression. Our study was aimed at evaluating 17 lncRNAs, whose targets were previously validated as key elements in MM, bone metabolism, and angiogenesis in MM subjects without BONJ (MM group), in MM subjects with BONJ (BONJ group), and a group of healthy controls (CTRL group). Our results demonstrated a different lncRNA profile in BONJ patients compared to MM patients and controls. Two lncRNAs (DANCR and MALAT1) were both downregulated compared to controls and MM, twelve (HOTAIR, MEG3, TP73-AS1, HOTTIP, HIF1A-AS2, MANTIS, CTD-2201E18, CTD1-2003C8, R-471B22, RP1-43E13, RP11-553L6.5, and RP1-286D6) were overexpressed in MM with BONJ, and one (H19) was upregulated compared with only MM. Two lncRNAs (JHDMD1 and MTMR9LP) had higher expression, but these differences were not statistically significant. The examined lncRNAs target several genes and metabolic pathways. An altered lncRNA signature could contribute to the onset of BONJ or have a protective action. Targeting these lncRNAs could offer a possibility for the prevention or therapy of BONJ.

Long noncoding RNA LINC00314 facilitates osteogenic differentiation of adipose-derived stem cells through the hsa-miR-129-5p/GRM5 axis via the Wnt signaling pathway

Background

Many studies have shown that long noncoding RNAs (lncRNAs) are closely related to the stimulation of osteogenic differentiation of adipose-derived stem cells (ADSCs) and the prevention of osteoporosis. Current research aimed to investigate the novel lncRNA and explored the function and molecular mechanism of the LINC00314/miR-129-5p/GRM5 axis in regulating osteogenic differentiation of ADSCs.

Methods

LncRNA and miRNA sequencing was performed in normal and osteogenic differentiation-induced ADSCs (osteogenic group). Abnormally expressed lncRNAs and miRNAs were obtained by the R software and the relative expression of LINC00314, miR-129-5p, and GRM5 during osteogenic induction was measured by RT-PCR. ADSCs were then transfected with pcDNA3.1-sh-LINC00314 and agomiR-129-5p. Alizarin red staining (ARS) and alkaline phosphatase (ALP) staining were performed to identify the mechanism of the LINC00314/miR-129-5p/GRM5 axis in regulating osteogenic differentiation of ADSCs.

Results

LINC00314 was significantly upregulated in the group of osteogenic-induced ADSCs. LINC00314 and GRM5 mimics increased the early and late markers of osteogenic differentiation, which manifest in not only the markedly increased ALP activity but also higher calcium deposition, while miR-129-5p mimic had the opposite effects. LINC00314 directly targeted miR-129-5p through luciferase reporter assay, and miR-129-5p suppressed GRM5 expression. Moreover, the LINC00314/miR-129-5p/GRM5 regulatory axis activated the Wnt/β-catenin signaling pathway.

Conclusions

LINC00314 confers contributory function in the osteogenic differentiation of ADSCs and thus the LINC00314/miR-129-5p/GRM5 axis may be a novel mechanism for osteogenic-related disease.

RHPN1-AS1 promotes cell proliferation and migration via miR-665/Akt3 in ovarian cancer

Recent efforts have revealed that long non-coding RNAs exert crucial roles in cancer initiation and progression. RHPN1-AS1 is a 2030 bp transcript from human chromosome 8q24, and involved in tumorigenesis in uveal melanoma and non-small cell lung cancer, but it remains unknown in ovarian cancer. This study focused on the role of RHPN1-AS1 in ovarian cancer and found that RHPN1-AS1 was up-regulated in ovarian cancer tissues and cell lines. Overexpression of RHPN1-AS1 promoted ovarian cancer cell proliferation, migration, and invasion. Mechanistically, overexpression of RHPN1-AS1 decreased the expression of miR-665 and subsequently promoted the expression of Akt3 at posttranscriptional level. Taken together, RHPN1-AS1 positively regulated the expression of Akt3 through sponging miR-665, and exerted an oncogenic role in ovarian cancer progression, and indicates that RHPN1-AS1 may be a potential therapeutic target in ovarian cancer.

Knockdown of HIF1A-AS2 suppresses TRIM44 to protect cardiomyocytes against hypoxia-induced injury

Myocardial infarction (MI) is a common cardiovascular disease characterized by an interruption of blood and oxygen supply to the heart, which results in gradual damage to the myocardial tissue and ultimately heart failure. The role of long non-coding RNAs in the pathology of MI remains in its infancy, but has been implicated in MI and other heart conditions. For example, the expression of a non-coding RNA hypoxia-inducible factor 1α (HIF1A)-antisense RNA 2 (HIF1A-AS2) has previously been linked to coronary heart disease, however, whether HIF1A-AS2 expression is also high in MI has not been addressed. Here, we report that HIF1A-AS2 is upregulated in hypoxia-treated human cardiomyocytes (HMCs) compared with normal cardiomyocytes, and that silenced HIF1A-AS2 inhibited apoptosis and facilitated viability, migration, and invasion of HMCs. Our data suggested that in MI, HIF1A-AS2 upregulation was associated with miR-623, which promoted expression of tripartite motif containing 44 (TRIM44). Moreover, by upregulating TRIM44 we were able to remedy the HIF1A-AS2 repression of apoptosis in HMCs. Thus, we conclude that cardiomyocytes can be protected against hypoxic-treated injury by knockdown of HIF1A-AS2, which suppresses TRIM44, and that HIF1A-AS2 overexpression is a prognostic indicator of MI.

Long noncoding RNA HIF1A-AS2 facilitates cell survival and migration by sponging miR-33b-5p to modulate SIRT6 expression in osteosarcoma

Long noncoding RNAs (lncRNAs) are emerging as vital regulators in various physiological and pathological processes. It was recently found that lncRNA HIF1A-AS2 could play oncogenic roles in several cancers. However, the function and regulatory mechanism of lncRNA HIF1A-AS2 in osteosarcoma (OS) remain largely unclear. In this study, we demonstrated that HIF1A-AS2 was overexpressed in OS tissues and cells. Downregulation of HIF1A-AS2 significantly affects multiple biological functions in OS cells, including cell proliferation, cell cycle progression, cell apoptosis, cell migration, and cell invasiveness. Mechanistic investigations demonstrated that HIF1A-AS2 can interact with miR-33b-5p and negatively regulate its expression, thereby upregulating the protein expression of miR-33b-5p’s target SIRT6. Additionally, in vivo experiments using a xenograft tumor mouse model revealed that downregulation of HIF1A-AS2 suppresses tumor growth in OS. Taken together, a newly identified regulatory mechanism for the lncRNA HIF1A-AS2–miR-33b-5p–SIRT6 axis was systematically studied in OS, which could be a promising target for the treatment of OS.

Long noncoding RNA expression profiles during the NEL-like 1 protein-induced osteogenic differentiation

Long noncoding RNAs (lncRNAs) are important modulators of mesenchymal stem cells (MSCs) in cellular differentiation. However, the regulatory mechanisms of lncRNAs in NEL-like 1 (NELL-1)-induced osteogenic differentiation of human adipose-derived stem cells remain elusive. Expression profiles of lncRNAs and messenger RNAs during NELL-1-induced osteogenesis were obtained using high-throughput sequencing. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway analysis, and gene coexpression networks were performed. We identified 323 statistically differentially expressed lncRNAs during osteogenesis and NELL-1-induced osteogenesis, and three lncRNAs (ENST00000602964, ENST00000326734, and TCONS_00006792) were identified as core regulators. Hedgehog pathway markers, including IHH and GLI1, were downregulated, while the antagonists of this pathway (GLI3 and HHIP) were upregulated during NELL-1-induced osteogenesis. In this process, the antagonist of Wnt, SFRP1, was downregulated. According to the analysis, we speculated that lncRNAs played important roles in NELL-1-induced osteogenesis via the crosstalk between Hedgehog and Wnt pathways.

LncRNA TUG1 promoted osteogenic differentiation through promoting bFGF ubiquitination

LncRNA TUG1 has the potential to promote the osteogenic differentiation of several cells, but the role of lncRNA TUG1 in osteogenic differentiation of tendon stem/progenitor cells (TSPCs) is still unknown. This study aims to determine the role of lncRNA TUG1 in osteogenic differentiation of TSPCs. bFGF, RUNX2, and Osterix protein expressions were detected by western blot. LncRNA TUG1 and bFGF expression was detected by qRT-PCR. RNA immunoprecipitation (RIP) assay was used to confirm the interaction between TUG1 and bFGF2. Ubiquitination assay was used to determine the ubiquitination of bFGF protein. During osteogenic differentiation, the protein expression of bFGF was significantly downregulated in TSPCs, and the expression of TUG1 was significantly elevated in TSPCs. Interfering TUG1 or overexpressing bFGF suppressed osteogenic differentiation of TSPCs. In addition, lncRNA TUG1 interacted with bFGF, and lncRNA TUG1 promoted the ubiquitination of bFGF protein. We also determined that lncRNA TUG1 downregulated bFGF protein expression through promoting the ubiquitination of bFGF. LncRNA TUG1 promoted the osteogenic differentiation of TSPCs through promoting bFGF ubiquitination.

Dicalcium silicate microparticles modulate the differential expression of circRNAs and mRNAs in BMSCs and promote osteogenesis via circ_1983–miR-6931–Gas7 interaction

Among C₂S-induced differentially expressed circRNAs, circ_1983 is involved in osteogenesis via circ_1983–miR-6931–Gas7 ceRNA interaction-mediated Runx2 upregulation.

miR-144-3p Suppresses Osteogenic Differentiation of BMSCs from Patients with Aplastic Anemia through Repression of TET2

Reduced osteogenic capacity of bone marrow mesenchymal stem cells (BMSCs) has been causally linked to the development of aplastic anemia. In this work, we aimed to identify novel microRNAs (miRNAs) that participate in the regulation of differentiation of BMSCs from patients with aplastic anemia. We show that miR-144-3p is significantly upregulated in BMSCs from patients with aplastic anemia relative to control equivalents. Depletion of miR-144-3p significantly enhances osteogenic differentiation of BMSCs from patients with aplastic anemia after culturing in osteogenesis-inducing medium. Conversely, overexpression of miR-144-3p blocks osteogenic differentiation of BMSCs. Mechanistically, miR-144-3p negatively regulates the expression of ten-eleven translocation 2 (TET2) in BMSCs. Reduced TET2 expression is associated with a significant decrease in global 5-hydroxymethyl-cytosine (5hmC) levels and osteogenic gene expression. Knockdown of miR-144-3p elevates the expression of TET2 and total 5hmC levels in BMSCs. Silencing of TET2 inhibits the osteogenic differentiation of BMSCs. Overexpression of TET2 reverses miR-144-3p-mediated inhibition of osteogenesis. In addition, there is a significant negative correlation between the expression of miR-144-3p and TET2 in BMSCs from patients with aplastic anemia. Overall, miR-144-3p impairs the osteogenic capacity of BMSCs from patients with aplastic anemia through repression of TET2. Therefore, the targeting of miR-144-3p may be a therapeutic strategy against aplastic anemia.

Phosphoinositide 3 Kinase Signaling in Human Stem Cells from Reprogramming to Differentiation: A Tale in Cytoplasmic and Nuclear Compartments

Stem cells are undifferentiated cells that can give rise to several different cell types and can self-renew. Given their ability to differentiate into different lineages, stem cells retain huge therapeutic potential for regenerative medicine. Therefore, the understanding of the signaling pathways involved in stem cell pluripotency maintenance and differentiation has a paramount importance in order to understand these biological processes and to develop therapeutic strategies. In this review, we focus on phosphoinositide 3 kinase (PI3K) since its signaling pathway regulates many cellular processes, such as cell growth, proliferation, survival, and cellular transformation. Precisely, in human stem cells, the PI3K cascade is involved in different processes from pluripotency and induced pluripotent stem cell (iPSC) reprogramming to mesenchymal and oral mesenchymal differentiation, through different and interconnected mechanisms.

Long noncoding RNAs: a missing link in osteoporosis

Osteoporosis is a systemic disease that results in loss of bone density and increased fracture risk, particularly in the vertebrae and the hip. This condition and associated morbidity and mortality increase with population ageing. Long noncoding (lnc) RNAs are transcripts longer than 200 nucleotides that are not translated into proteins, but play important regulatory roles in transcriptional and post-transcriptional regulation. Their contribution to disease onset and development is increasingly recognized. Herein, we present an integrative revision on the studies that implicate lncRNAs in osteoporosis and that support their potential use as therapeutic tools. Firstly, current evidence on lncRNAs involvement in cellular and molecular mechanisms linked to osteoporosis and its major complication, fragility fractures, is reviewed. We analyze evidence of their roles in osteogenesis, osteoclastogenesis, and bone fracture healing events from human and animal model studies. Secondly, the potential of lncRNAs alterations at genetic and transcriptomic level are discussed as osteoporosis risk factors and as new circulating biomarkers for diagnosis. Finally, we conclude debating the possibilities, persisting difficulties, and future prospects of using lncRNAs in the treatment of osteoporosis.