LncRNA TINCR/miR-31-5p/C/EBP-α feedback loop modulates the adipogenic differentiation process in human adipose tissue-derived mesenchymal stem cells

Lineage-specific exosomes promote the odontogenic differentiation of human dental pulp stem cells (DPSCs) through TGFβ1/smads signaling pathway via transfer of microRNAs

Background

Exosomes derived from dental pulp stem cells (DPSCs) can be used as biomimetic tools to induce odontogenic differentiation of stem cells, but the regulatory mechanisms and functions of exosome-encapsulated microRNAs are still unknown. The present study aimed to clarify the role of microRNAs contained in the exosomes derived from human DPSCs and their potential signaling cascade in odontogenic differentiation.

Methods

Exosomes were isolated from human DPSCs cultured undergrowth and odontogenic differentiation conditions, named UN-Exo and OD-Exo, respectively. The microRNA sequencing was performed to explore the microRNA profile contained in UN-Exo and OD-Exo. Pathway analysis was taken to detect enriched pathways associated with the predicted target genes of microRNAs. The regulatory roles of a highly expressed microRNA in OD-Exo were investigated through its inhibition or overexpression (miRNA inhibitors and miRNA mimics). Automated western blot was used to identify the function of exosomal microRNA and the roles of TGFβ1/smads pathway in odontogenic differentiation of DPSCs. A luciferase reporter gene assay was used to verify the direct target gene of exosomal miR-27a-5p.

Results

Endocytosis of OD-Exo triggered odontogenic differentiation of DPSCs by upregulating DSP, DMP-1, ALP, and RUNX2 proteins. MicroRNA sequencing showed that 28 microRNAs significantly changed in OD-Exo, of which 7 increased and 21 decreased. Pathway analysis showed genes targeted by differentially expressed microRNAs were involved in multiple signal transductions, including TGFβ pathway. 16 genes targeted by 15 differentially expressed microRNAs were involved in TGFβ signaling. Consistently, automated western blot found that OD-Exo activated TGFβ1 pathway by upregulating TGFβ1, TGFR1, p-Smad2/3, and Smad4 in DPSCs. Accordingly, once the TGFβ1 signaling pathway was inhibited by SB525334, protein levels of p-Smad2/3, DSP, and DMP-1 were significantly decreased in DPSCs treated with OD-Exo. MiR-27a-5p was expressed 11 times higher in OD-Exo, while miR-27a-5p promoted odontogenic differentiation of DPSCs and significantly upregulated TGFβ1, TGFR1, p-Smad2/3, and Smad4 by downregulating the inhibitory molecule LTBP1.

Conclusions

The microRNA expression profiles of exosomes derived from DPSCs were identified. OD-Exo isolated under odontogenic conditions were better inducers of DPSC differentiation. Exosomal microRNAs promoted odontogenic differentiation via TGFβ1/smads signaling pathway by downregulating LTBP1.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1278-x) contains supplementary material, which is available to authorized users.

GROWTH AND DEVELOPMENT SYMPOSIUM: STEM AND PROGENITOR CELLS IN ANIMAL GROWTH: Long noncoding RNAs in adipogenesis and adipose development of meat animals12

Sequencing technology, especially next-generation RNA sequencing, has greatly facilitated the identification and annotation of long noncoding RNAs (lncRNAs). In mammals, a large number of lncRNAs have been identified, which regulate various biological processes. An increasing number of lncRNAs have been identified which could function as key regulators of adipogenesis (adipocyte formation), a key step of the development of adipose tissue. Because proper adipose tissue development is a key factor affecting animal growth efficiency, lean/fat ratio, and meat quality, summarizing the roles and recent advances of lncRNAs in adipogenesis is needed in order to develop strategies to effectively manage fat deposition. In this review, we updated lncRNAs contributed to the regulation of adipogenesis, focusing on their roles in fat development of farm animals.

H19/miR-30a/C8orf4 axis modulates the adipogenic differentiation process in human adipose tissue-derived mesenchymal stem cells

The adipogenic differentiation of adipose tissue-derived mesenchymal stem cells (ADSCs) is a critical issue in many obesity-related disorders. Cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT) enhancer binding protein α (CEBP-α) and peroxisome proliferator-activated receptor-γ are two important lipogenic and adipogenic transcription factors and markers in adipogenic differentiation. Noncoding RNAs participate in adipogenic differentiation. The long noncoding RNA (lncRNA) H19 is related to multiple cellular differentiation, including adipogenic differentiation; however, its function and precise molecular mechanism in human ADSCs (hADSCs) adipogenic differentiation are unclear. microRNAs that were differentially expressed in adipogenic differentiation and could be targeted by H19 were screened and selected; the regulation and interaction between H19 and miR-30a were verified. The interaction between miR-30a and predicted downstream target C8orf4 was validated. The dynamic effects of H19 and miR-30a on C8orf4 messenger RNA (mRNA) expression and protein and adipogenic differentiation were evaluated. miR-30a negatively regulated H19 with each other through direct binding. As predicted by TargetScan and verified using luciferase reporter gene assays, miR-30a directly bound to the 3'-untranslated region of C8orf4 to inhibit its expression; H19 knockdown suppressed while miR-30a inhibition promoted the mRNA expression and the protein levels of C8orf4 and adipogenic differentiation; the effect of H19 knockdown could be partially reversed by miR-30a inhibition. The lncRNA H19 serves as a competing endogenous RNA (ceRNA) for miR-30a to augment miR-30a downstream target C8orf4, therefore modulating adipogenic differentiation in hADSCs. From the perspective of lncRNA-miRNA-mRNA regulation, we provided a novel regulatory mechanism of hADSCs adipogenic differentiation.

UCA1 promotes cell viability, proliferation and migration potential through UCA1/miR-204/CCND2 pathway in primary cystitis glandularis cells

Cystitis glandularis (CG) is an unusual proliferative disorder of the urinary bladder. Increasing evidences demonstrated that long non-coding RNAs (lncRNAs) play important roles in a variety of cellular progresses. However, there are rarely reports about the role and underlying molecular mechanism of lncRNAs in CG. In this study, we firstly isolated the primary cells from the tissues of CG and adjacent normal tissues, and found that UCA1 was up-regulated in the primary CG cells (pCGs). Then, we showed that knock out of UCA1 reduced the cell viability, inhibited the cell proliferation and restrained the migration potential and overexpression of UCA1 promoted that in pCGs. Furthermore, we demonstrated that UCA1 played its role via sponging of the miR-204 in pCGs. In addition, we illustrated that miR-204 exerted its function via targeting CYCLIN D2 (CCND2) 3'UTR at mRNA level in pCGs. Ultimately, we revealed the role and regulation of UCA1/miR-204/CCND2 regulatory axis in pCGs. In summary, our study, for the first time, revealed the role and underlying mechanism of an lncRNA UCA1 in CG, providing a potential biomarker and therapeutic target for human CG.

MicroRNA‑31 promotes chondrocyte proliferation by targeting C‑X‑C motif chemokine ligand 12

The present study aimed to investigate the biological function and underlying molecular mechanisms of miR-31 in osteoarthritis (OA). Reverse transcription-quantitative polymerase chain reaction was used to detect miR-31 expression, and it was found that miR-31 was downregulated in the cartilage tissues of OA patients. microRNA.org was used to predict the gene targets of miR-31, and dual luciferase reporter assays were used to verify that C-X-C motif chemokine ligand 12 (CXCL12) was a direct target of miR-31. The human chondrocyte cell line CHON-001 was used to perform MTT and cell migration assays. Western blotting was used to measure the protein expression of CXCL12, type I collagen and aggrecan. The results suggested that CXCL12 was a target of miR-31, and the expression of CXCL12 was negatively regulated by miR-31 in CHON-001 cells. miR-31 increased CHON-001 cell viability and migration, as well as the expression of type I collagen and aggrecan. Furthermore, the overexpression of CXCL12 eliminated the effects of miR-31 mimics on CHON-001 cells. In conclusion, the data indicated that miR-31 promoted chondrocyte viability and migration by directly targeting CXCL12, which provided evidence for CXCL12 as a potential target in OA therapy.