scholarly journals Metformin-Induced MicroRNA-34a-3p Downregulation Alleviates Senescence in Human Dental Pulp Stem Cells by Targeting CAB39 through the AMPK/mTOR Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Shuo Zhang ◽  
Rong Zhang ◽  
Pengyan Qiao ◽  
Xiaocao Ma ◽  
Rongjian Lu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Signaling Pathway ◽  
Calcium Binding ◽  
Dental Pulp ◽  
Dental Pulp Stem Cells ◽  
Mtor Signaling ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Mtor Signaling Pathway ◽  
Dental Tissues

Dental pulp stem cells (DPSCs) are ideal seed cells for the regeneration of dental tissues. However, DPSC senescence restricts its clinical applications. Metformin (Met), a common prescription drug for type 2 diabetes, is thought to influence the aging process. This study is aimed at determining the effects of metformin on DPSC senescence. Young and aging DPSCs were isolated from freshly extracted human teeth. Flow cytometry confirmed that DPSCs expressed characteristic surface antigen markers of mesenchymal stem cells (MSCs). Cell Counting Kit-8 (CCK-8) assay showed that a concentration of 100 μM metformin produced the highest increase in the proliferation of DPSCs. Metformin inhibited senescence in DPSCs as evidenced by senescence-associated β-galactosidase (SA-β-gal) staining and the expression levels of senescence-associated proteins. Additionally, metformin significantly suppressed microRNA-34a-3p (miR-34a-3p) expression, elevated calcium-binding protein 39 (CAB39) expression, and activated the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathway. Dual-luciferase reporter assay confirmed that CAB39 is a direct target for miR-34a-3p. Furthermore, transfection of miR-34a-3p mimics promoted the senescence of DPSCs, while metformin treatment or Lenti-CAB39 transfection inhibited cellular senescence. In conclusion, these results indicated that metformin could alleviate the senescence of DPSCs by downregulating miR-34a-3p and upregulating CAB39 through the AMPK/mTOR signaling pathway. This study elucidates on the inhibitory effect of metformin on DPSC senescence and its potential as a therapeutic target for senescence treatment.

scholarly journals Shikonin induces odontoblastic differentiation of dental pulp stem cells via AKT–mTOR signaling in the presence of CD44

2020 ◽  
Author(s):  
Kunihiro Kajiura ◽  
Naoki Umemura ◽  
Emika Ohkoshi ◽  
Takahisa Ohta ◽  
Nobuo Kondoh ◽  
...  
Keyword(s):  
Stem Cells ◽  
Signaling Pathway ◽  
Vitamin K ◽  
Dental Pulp ◽  
Dental Pulp Stem Cells ◽  
Mtor Signaling ◽  
Mtor Signaling Pathway ◽  
Cd44 Expression ◽  
Dentin Sialophosphoprotein ◽  
Odontoblastic Differentiation

AbstractIn our previous study, we demonstrated that hyaluronan induces odontoblastic differentiation of dental pulp stem cells via interactions with CD44. However, it remains unclear whether CD44 expression by dental pulp stem cells is required for odontoblastic differentiation. Therefore, we searched for a compound that induces odontoblastic differentiation of dental pulp stem cells, regardless of the chemical structure and function of hyaluronan, and examined whether CD44 is involved in the induction of odontoblastic differentiation by the compound. Because vitamin K analogues can promote bone formation and tissue calcification, we focused on derivatives of naphthoquinone, the skeleton of vitamin K; we verified whether those compounds could induce odontoblastic differentiation of dental pulp stem cells. We found that dentin sialophosphoprotein, a marker of odontoblasts, was expressed in dental pulp stem cells after treatment with shikonin. The shikonin-induced expression of dentin sialophosphoprotein was inhibited by PI3K, AKT, and mTOR inhibitors. In addition, in dental pulp stem cells transfected with siRNA against CD44, the shikonin-induced expression of dentin sialophosphoprotein was inhibited. Thus, shikonin can stimulate dental pulp stem cells to undergo odontoblastic differentiation through a mechanism involving the AKT–mTOR signaling pathway and CD44. Hyaluronan stimulated dental pulp stem cells to undergo CD44-mediated odontoblastic differentiation in our previous study; the present study indicated that CD44 is necessary for dental pulp stem cells to undergo odontoblastic differentiation. Although expression of CD44 is important for inducing odontoblastic differentiation of dental pulp stem cells, the relationship between the AKT–mTOR signaling pathway and CD44 expression, in the context of shikonin stimulation, has not yet been elucidated. This study suggested that shikonin may be useful for inducing odontoblastic differentiation of dental pulp stem cells, and that it may have clinical applications, including protection of dental pulp.

scholarly journals Dihydromyricetin promotes autophagy and attenuates renal interstitial fibrosis by regulating miR-155-5p/PTEN signaling in diabetic nephropathy

2019 ◽  
Author(s):  
Liming Guo ◽  
Kuibi Tan ◽  
Qun Luo ◽  
Xu Bai
Keyword(s):  
Diabetic Nephropathy ◽  
Signaling Pathway ◽  
Rat Model ◽  
Interstitial Fibrosis ◽  
Mtor Signaling ◽  
Luciferase Assay ◽  
Luciferase Reporter ◽  
Mtor Signaling Pathway ◽  
Renal Interstitial Fibrosis ◽  
Gene Assay

Diabetic nephropathy (DN) is the most common complication of diabetes and is prone to kidney failure. Dihydromyricetin (DHM) has been reported to have a variety of pharmacological activities. This study aims to explore the effect of DHM on DN and the underlying molecular mechanism. An in vivo DN rat model was established. The degree of renal interstitial fibrosis (RIF) was detected by hematoxylin-eosin (HE) staining, Masson's trichrome staining, and immunohistochemistry (IHC). In vitro, NRK-52E cells were divided into four groups: normal glucose (NG), high glucose (HG), HG+DHM, and HG+rapamycin (autophagy inhibitor). The levels of autophagy- and fibrosis-related proteins were analyzed by western blotting. The expression of miR-155-5p and phosphatase and tensin homolog deleted on chromosome ten (PTEN) and their relationship were assessed by quantitative reverse transcription (qRT)-PCR and dual luciferase reporter gene assay. Our results showed that RIF was increased in DN rat model and in HG-induced NRK-52E cells. DHM treatment attenuated the increased RIF and also increased autophagy. MiR-155-5p expression was increased, while PTEN expression was decreased in DN rat and cell model, and DHM reversed both effects. Dual luciferase assay showed that PTEN was the target gene of miR-155-5p. DHM inhibited HG-induced fibrosis and promoted autophagy by inhibiting miR-155-5p expression in NRK-52E cells. In addition, DHM promoted autophagy by inhibiting the PI3K/AKT/mTOR signaling pathway. In conclusion, DHM promotes autophagy and attenuates RIF by regulating the miR-155-5p/PTEN signaling and PI3K/AKT/mTOR signaling pathway in DN.

scholarly journals Novel Molecule Nell-1 Promotes the Angiogenic Differentiation of Dental Pulp Stem Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Mengyue Li ◽  
Qiang Wang ◽  
Qi Han ◽  
Jiameng Wu ◽  
Hongfan Zhu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Dental Pulp ◽  
Umbilical Vein ◽  
Dental Pulp Stem Cells ◽  
Exposure Model ◽  
Dental Tissues ◽  
Normal Rat ◽  
Pulp Exposure ◽  
Angiogenic Markers

IntroductionThis work aimed to reveal the crucial role of Nell-1 in the angiogenic differentiation of human dental pulp stem cells (DPSCs) alone or co-cultured with human umbilical vein endothelial cell (HUVECs) in vitro and whether this molecule is involved in the pulp exposure model in vivo.MethodsImmunofluorescence was conducted to ascertain the location of Nell-1 on DPSCs, HUVECs, and normal rat dental tissues. RT-PCR, Western blot, and ELISA were performed to observe the expression levels of angiogenic markers and determine the angiogenic differentiation of Nell-1 on DPSCs alone or co-cultured with HUVECs, as well as in vitro tube formation assay. Blood vessel number for all groups was observed and compared using immunohistochemistry by establishing a rat pulp exposure model.ResultsNell-1 is highly expressed in the nucleus of DPSCs and HUVECs and is co-expressed with angiogenic markers in normal rat pulp tissues. Hence, Nell-1 can promote the angiogenic marker expression in DPSCs alone and co-cultured with other cells and can enhance angiogenesis in vitro as well as in the pulp exposure model.ConclusionNell-1 may play a positive role in the angiogenic differentiation of DPSCs.

Quercetin suppresses breast cancer stem cells (CD44 + /CD24 − ) by inhibiting the PI3K/Akt/mTOR-signaling pathway

Life Sciences ◽  
2018 ◽  
Vol 196 ◽  
pp. 56-62 ◽  
Author(s):  
Xiuli Li ◽  
Na Zhou ◽  
Jin Wang ◽  
Zhijie Liu ◽  
Xiaohui Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Signaling Pathway ◽  
Mtor Signaling ◽  
Breast Cancer Stem Cells ◽  
Mtor Signaling Pathway

scholarly journals Melatonin-induced Cell Rejuvenation from Long-term Ex-vivo passaging Functioned by its Restoration of Damaged Cell Autophagic Processes

2020 ◽  
Author(s):  
Yi-Zhou Tan ◽  
Xin-Yue Xu ◽  
Ji-Min Dai ◽  
Yuan Yin ◽  
Xiao-Tao He ◽  
...  
Keyword(s):  
Stem Cells ◽  
Signaling Pathway ◽  
Cellular Senescence ◽  
Ex Vivo ◽  
Mtor Signaling ◽  
Beclin 1 ◽  
Dependent Manner ◽  
Mtor Signaling Pathway ◽  
Associated Proteins

Abstract Background: Stem cells undergone long-term ex-vivo expansion are most likely functionally compromised (namely cellular senescence) in terms of their stem cell properties and therapeutic potentials. Due to the ability to attenuate cellular senescence, melatonin (MLT) has been proposed as an adjuvant across long-term cell expansion protocols, but the underlying mechanism remains largely unknown. Methods: Human periodontal ligament stem cells (PDLSCs) were isolated and cultured ex-vivo for 15 passages, and passage 2, 7 and 15 cells were used to interrogate the cellular senescence and alteration in cell autophagy during long-term expansion. The cellular senescence features were evidenced by senescence-associated β-galacotosidase (SA-β-gal) activity and the expression of senescence-related proteins including p53, p21, p16 and γ-H2AX. Electronic microscope was used to observe the autophagic vesicles. Adenovirus mRFP-GFP-LC3 was transfected to indicate the alteration of autophagic flux during long-term expansion, and the autophagy-associated proteins Atg7, Beclin-1, LC3-II and p62 were evaluated by Western blot. Results: It was found that long-term in-vitro passaging led to an accumulated SA-β-gal, elevated expressions of p53, p21, p16 and γ-H2AX, along with downregulated autophagy-associated proteins Atg7, Beclin-1 and LC3 as well as a mounting autophagy substrate p62. In accordance with expectation, supplemented with MLT not only ameliorated cells to a younger state but also restored the impaired autophagy level in senescent cells. Additionally, we demonstrated that autophagy inhibitor could block such MLT-induced cell rejuvenation. When the underlying signaling pathways involved was interrogated, we found that MLT receptor (MT) participated in mediating MLT-related autophagy restoration by regulating PI3K/AKT/mTOR signaling pathway.Conclusions: The present study suggests that MLT may rejuvenate long-term expansion-caused cellular senescence by restoring autophagy, more likely via PI3K/AKT/mTOR signaling pathway in an MT-dependent manner. This is the first report identifying the MT-dependent PI3K/AKT/mTOR signaling involved in MLT-induced autophagy alteration, pointing to a potential target for using autophagy-restoring agents such as MLT to develop optimized clinical-scale cell production protocols.

scholarly journals Circ-FURIN Expression Enhances Osteoblast Differentiation In Dental Pulp Stem Cells Via SOX11 Signaling Pathway Sponging miR-125

2021 ◽  
Author(s):  
Fang Ji ◽  
Yueting Lin ◽  
Jing Pan ◽  
Zhao Yang ◽  
Qianhui Ren ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Formation ◽  
Signaling Pathway ◽  
Dental Pulp ◽  
Osteoblast Differentiation ◽  
Dental Pulp Stem Cells ◽  
Heterotopic Bone ◽  
Heterotopic Bone Formation ◽  
Downstream Target ◽  
Report Analysis

Abstract Background: Many studies have found that circRNA plays a part in osteoblast differentiation. However, its mechanism remains unknown. Methods: High-throughput sequencing was used to identifield the different expression of circRNA during osteogenic dental pulp stem cells (DPSCs) differentiation. Luciferase report analysis and RT-qPCR were used to clarify the expression and regulation relationship among circ-FURIN, miR-125 and SOX11. The heterotopic bone formation experiment was further used to confirm the osteoblast differentiation of DPSC with different expression of circ-FURIN, miR-125 and SOX11. Results: Study indicated that circ-FURIN expression remarkably increased during osteoblast differentiation, yet circ-FURIN knockdown suppressed it. Bioinformatics and luciferase results discovered that miR-125 is the downstream target of circ-FURIN. Furthermore, circ-FURIN upregulation decreased miR-125 expression. MiR-125 upregulation restored the promotion effect of circ-FURIN on osteogenic DPSC differentiation. Luciferase report analysis verified that SOX11 is miR-125 downstream target. miR-125 overexpression suppressed osteogenic DPSC differentiation through targeting SOX11. SOX11 overexpression restored miR-125 inhibitory effect on osteogenic DPSC differentiation. In vivo experiments with heterotopic bone model suggested that circ-FURIN overexpression has crucial function to enhance heterotopic bone formation. Conclusions: In summary, circ-FURIN enhances osteoblast DPSC differentiation via the SOX11 signaling pathway by sponging miR-125. These findings suggest a novel therapeutic target for osteoporosis treatment.

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