Sox9-Increased miR-322-5p Facilitates BMP2-Induced Chondrogenic Differentiation by Targeting Smad7 in Mesenchymal Stem Cells

Circular RNA circWNK1 inhibits the progression of gastric cancer via regulating the miR-21-3p/SMAD7 axis

Gastric cancer (GC) is a highly aggressive malignancy with limited treatment options for advanced-stage patients. Recent studies have highlighted the role of circular RNA (circRNA) as a novel regulator of cancer progression in various malignancies. However, the underlying mechanisms by which circRNA contributes to the development and progression of GC remain poorly understood. In this study, we utilized microarrays and real-time quantitative polymerase chain reaction (qRT-PCR) to identify and validate a downregulated circRNA, hsa_circ_0003251 (referred to as circWNK1), in paired GC and normal tissues. Through a series of in vitro and in vivo gain-of-function and loss-of-function assays, we demonstrated that circWNK1 exerts inhibitory effects on the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of GC cells. Additionally, we discovered that circWNK1 acts as a competitive endogenous RNA (ceRNA) for SMAD7 by sequestering miR-21-3p. Our findings were supported by comprehensive biological information analysis, as well as RNA pull-down, luciferase reporter gene, and western blot assays. Notably, the downregulation of circWNK1 in GC cells resulted in reduced SMAD7 expression, subsequently activating the TGF-β signaling pathway. Collectively, our study reveals that circWNK1 functions as a tumor suppressor in GC by regulating the miR-21-3p/SMAD7-mediated TGF-β signaling pathway. Furthermore, circWNK1 holds promise as a potential biomarker for the diagnosis and treatment of GC.

MircoRNA-322-5p promotes lipopolysaccharide-induced acute kidney injury mouse models and mouse primary proximal renal tubular epithelial cell injury by regulating T-box transcription factor 21/mitogen-activated protein kinase/extracellular signal-related kinase axis

INTRODUCTION AND OBJECTIVES

Acute kidney injury (AKI) is a common devastating complication characterized by an abrupt loss of renal function. It is of great significance to explore promising biomarkers for AKI treatment.

MATERIALS AND METHODS

Here, we established LPS (lipopolysaccharide)-induced AKI mice models and LPS-induced AKI mouse renal tubular epithelial cell model. The severity of AKI was determined by the levels of BUN (blood urea nitrogen) and SCr (serum creatinine), the observation of pathological section as well as the renal tubular injury score. The apoptosis was determined by the measurement of Caspase-3 and Caspase-9 activities, and cell apoptosis assays. qRT-PCR (quantitative real-time PCR) and western blot revealed that miR-322-5p (microRNA-322-5p) was up-regulated in LPS -induced AKI models while Tbx21 (T-box transcription factor 21) was down-regulated in LPS-induced AKI models. Dual-luciferase reporter and RNA pulldown assays detected the interaction of Tbx21 with miR-322-5p.

RESULTS

We found that miR-322-5p was overtly over-expressed in the in vitro LPS-induced AKI model and promoted the apoptosis of AKI mouse renal tubular epithelial cells via inhibiting Tbx21, which suppressed the mitochondrial fission and cell apoptosis through MAPK/ERK (mitogen-activated protein kinase/extracellular signal-related kinase) pathway.

CONCLUSIONS

We demonstrated that miR-322-5p promotes LPS-induced mouse AKI by regulating Tbx21/MAPK/ERK axis, which might provide new sights for AKI research.

Embryonic stem cell-derived extracellular vesicles rejuvenate senescent cells and antagonize aging in mice

Aging is a degenerative process that leads to tissue dysfunction and death. Embryonic stem cells (ESCs) have great therapeutic potential for age-related diseases due to their capacity for self-renewal and plasticity. However, the use of ESCs in clinical treatment is limited by immune rejection, tumourigenicity and ethical issues. ESC-derived extracellular vesicles (EVs) may provide therapeutic effects that are comparable to those of ESCs while avoiding unwanted effects. Here, we fully evaluate the role of ESC-EVs in rejuvenation in vitro and in vivo. Using RNA sequencing (RNA-Seq) and microRNA sequencing (miRNA-Seq) screening, we found that miR-15b-5p and miR-290a-5p were highly enriched in ESC-EVs, and induced rejuvenation by silencing the Ccn2-mediated AKT/mTOR pathway. These results demonstrate that miR-15b-5p and miR-290a-5p function as potent activators of rejuvenation mediated by ESC-EVs. The rejuvenating effect of ESC-EVs was further investigated in vivo by injection into aged mice. The results showed that ESC-EVs successfully ameliorated the pathological age-related phenotypes and rescued the transcriptome profile of aged mice. Our findings demonstrate that ESC-EVs treatment can rejuvenate senescence both in vitro and in vivo and suggest the therapeutic potential of ESC-EVs as a novel cell-free alternative to ESCs for age-related diseases.

YTHDF1 Enhances Chondrogenic Differentiation by Activating the Wnt/β-Catenin Signaling Pathway

Cartilage is derived from the chondrogenic differentiation of stem cells, for which the regulatory mechanism has not been fully elucidated. N6-methyladenosine (m6A) messenger RNA (mRNA) methylation is the most common posttranscriptional modification in eukaryotic mRNAs and is mediated by m6A regulators. However, whether m6A regulators play roles in chondrogenic differentiation is unknown. Herein, we aim to determine the role of a main m6A reader protein, YTH N6-methyladenosine RNA binding protein 1 (YTHDF1), in chondrogenic differentiation regulation. Western blotting (WB) assays found that the expression of YTHDF1 increased during chondrogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). The results of quantitative polymerase chain reaction, WB, immunohistochemistry, and Alcian blue staining revealed that overexpression of YTHDF1 increased cartilage matrix synthesis and the expression of chondrogenic markers when hBMSCs, ATDC5 cells, or C3H10T1/2 cells were induced to undergo chondrogenesis. Conversely, chondrogenesis was clearly inhibited when YTHDF1 was knocked down in hBMSCs, ATDC5 cells, or C3H10T1/2 cells. Further RNA sequencing and molecular biology experiments found that YTHDF1 activated the Wnt/β-catenin signaling pathway during chondrogenic differentiation. Finally, the effects of overexpression and knockdown of YTHDF1 on chondrogenic differentiation were reversed by inhibiting or activating β-catenin activity. Therefore, we demonstrated that YTDHF1 promoted chondrogenic differentiation through activation of the Wnt/β-catenin signaling pathway.

Comprehensive analysis of lncRNA-miRNA-mRNA networks during osteogenic differentiation of bone marrow mesenchymal stem cells

Background

Long non-coding RNA (lncRNA) plays crucial role in osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs), involving in regulation of competing endogenous RNA (ceRNA) mechanisms and conduction of signaling pathways. However, its mechanisms are poorly understood. This study aimed to investigate lncRNAs, miRNAs and mRNAs expression profiles in rat BMMSCs (rBMMSCs) osteogenic differentiation, screen the potential key lncRNA-miRNA-mRNA networks, explore the putative functions and identify the key molecules, as the basis of studying potential mechanism of rBMMSCs osteogenic differentiation driven by lncRNA, providing molecular targets for the management of bone defect.

Methods

High-throughput RNA sequencing (RNA-seq) was used to determine lncRNAs, miRNAs, and mRNAs expression profiles at 14-day rBMMSCs osteogenesis. The pivotal lncRNA-miRNA and miRNA-mRNA networks were predicted from sequencing data and bioinformatic analysis, and the results were exported by Cytoscape 3.9.0 software. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used for functional exploration. Real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to validate lncRNAs, miRNAs and mRNAs.

Results

rBMMSCs were identified, and the osteogenic and adipogenic differentiation ability were detected. A total of 8634 lncRNAs were detected by RNA-seq, and 1524 differential expressed lncRNAs, of which 812 up-regulated and 712 down-regulated in osteo-inductive groups compared with control groups. 30 up-regulated and 61 down-regulated miRNAs, 91 miRNAs were differentially expressed in total. 2453 differentially expressed mRNAs including 1272 up-expressed and 1181 down-expressed were detected. 10 up-regulated lncRNAs were chosen to predict 21 down-regulated miRNAs and 650 up-regulated mRNAs. 49 lncRNA-miRNA and 1515 miRNA–mRNA interactive networks were constructed. GO analysis showed the most important enrichment in cell component and molecular function were “cytoplasm” and “protein binding”, respectively. Biological process related to osteogenic differentiation such as “cell proliferation”, “wound healing”, “cell migration”, “osteoblast differentiation”, “extracellular matrix organization” and “response to hypoxia” were enriched. KEGG analysis showed differentially expressed genes were mainly enriched in “PI3K-Akt signaling pathway”, “Signaling pathway regulating pluripotency of stem cells”, “cGMP-PKG signaling pathway”, “Axon guidance” and “Calcium signaling pathway”. qRT-PCR verified that lncRNA Tug1, lncRNA AABR07011996.1, rno-miR-93-5p, rno-miR-322-5p, Sgk1 and Fzd4 were consistent with the sequencing results, and 4 lncRNA-miRNA-mRNA networks based on validations were constructed, and enrichment pathways were closely related to “PI3K-Akt signaling pathway”, “Signaling pathway regulating pluripotency of stem cells” and “Wnt signaling pathway”.

Conclusions

lncRNAs, miRNAs and mRNAs expression profiles provide clues for future studies on their roles for BMMSCs osteogenic differentiation. Furthermore, lncRNA–miRNA–mRNA networks give more information on potential new mechanisms and targets for management on bone defect.

Supplementary information

The online version contains supplementary material available at 10.1186/s12864-022-08646-x.