scholarly journals Cell cycle exit during bortezomib‐induced osteogenic differentiation of mesenchymal stem cells was mediated by Xbp1s‐upregulated p21 Cip1 and p27 Kip1

2020 ◽  
Vol 24 (16) ◽  
pp. 9428-9438
Author(s):  
Dan Zhang ◽  
Rong Fan ◽  
Li Lei ◽  
Lei Lei ◽  
Yanmeng Wang ◽  
...  
2021 ◽  
Author(s):  
Mohammad Rumman ◽  
Jyotsna Dhawan

Bone marrow mesenchymal stem cells (MSCs) are heterogeneous osteo-progenitors that are mainly responsible for bone regeneration and homeostasis. In vivo, a subpopulation of bone marrow MSCs persists in a quiescent state, providing a source of new cells for repair. Previously, we reported that induction of quiescence in hMSCs in vitro skews their differentiation potential in favour of osteogenesis while suppressing adipogenesis. Here, we uncover a new role for a protein tyrosine phosphatase, receptor type U (PTPRU) in repressing osteogenesis during quiescence. A 75 kD PTPRU protein isoform was found to be specifically induced during quiescence and down-regulated during cell cycle reactivation. Using siRNA-mediated knockdown, we report that in proliferating hMSC, PTPRU preserves self-renewal, while in quiescent hMSC, PTPRU not only maintains reversibility of cell cycle arrest but also suppresses expression of osteogenic lineage genes. Knockdown of PTPRU in proliferating or quiescent hMSC de-represses osteogenic markers, and enhances induced osteogenic differentiation. We also show that PTPRU positively regulates a β-catenin-TCF transcriptional reporter. Taken together, our study suggests a role for a quiescence-induced 75kD PTPRU isoform in modulating bone differentiation in hMSC, potentially involving the Wnt pathway.


Development ◽  
2021 ◽  
Vol 148 (8) ◽  
Author(s):  
Jiahui Du ◽  
Junjun Jing ◽  
Shuo Chen ◽  
Yuan Yuan ◽  
Jifan Feng ◽  
...  

ABSTRACT Stem cells self-renew or give rise to transit-amplifying cells (TACs) that differentiate into specific functional cell types. The fate determination of stem cells to TACs and their transition to fully differentiated progeny is precisely regulated to maintain tissue homeostasis. Arid1a, a core component of the switch/sucrose nonfermentable complex, performs epigenetic regulation of stage- and tissue-specific genes that is indispensable for stem cell homeostasis and differentiation. However, the functional mechanism of Arid1a in the fate commitment of mesenchymal stem cells (MSCs) and their progeny is not clear. Using the continuously growing adult mouse incisor model, we show that Arid1a maintains tissue homeostasis through limiting proliferation, promoting cell cycle exit and differentiation of TACs by inhibiting the Aurka-Cdk1 axis. Loss of Arid1a overactivates the Aurka-Cdk1 axis, leading to expansion of the mitotic TAC population but compromising their differentiation ability. Furthermore, the defective homeostasis after loss of Arid1a ultimately leads to reduction of the MSC population. These findings reveal the functional significance of Arid1a in regulating the fate of TACs and their interaction with MSCs to maintain tissue homeostasis.


2013 ◽  
Vol 40 (12) ◽  
pp. 1220
Author(s):  
Jing XU ◽  
Dan ZHAO ◽  
Jian WANG ◽  
WenJuan WANG ◽  
JinYong LUO

2019 ◽  
Author(s):  
Leiluo Yang ◽  
Qing Li ◽  
Junhong Zhang ◽  
Pengcheng Li ◽  
Chaoliang Wang ◽  
...  

2019 ◽  
Vol 19 (9) ◽  
pp. 688-698 ◽  
Author(s):  
Azam Roohi ◽  
Mahin Nikougoftar ◽  
Hamed Montazeri ◽  
Shadisadat Navabi ◽  
Fazel Shokri ◽  
...  

Background: Oxidative stress and chronic hyperglycemia are two major side effects of type 2 diabetes affecting all cell types including mesenchymal stem cells (MSCs). As a cell therapy choice, understanding the behavior of MSCs will provide crucial information for efficient treatment. Methods: Placental mesenchymal stem cells were treated with various concentrations of glucose, metformin, rapamycin, and hydrogen peroxide to monitor their viability and cell cycle distribution. Cellular viability was examined via the MTT assay. Cell cycle distribution was studied by propidium iodide staining and apoptosis was determined using Annexin Vpropidium iodide staining and flow cytometry. Involvement of potential signaling pathways was evaluated by Western blotting for activation of Akt, P70S6K, and AMPK. Results: The results indicated that high glucose augmented cell viability and reduced metformin toxic potential. However, the hydrogen peroxide and rapamycin toxicities were exacerbated. Conclusion: Our findings suggest that high glucose concentration has a major effect on placental mesenchymal stem cell viability in the presence of rapamycin, metformin and hydrogen peroxide in culture.


Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 339
Author(s):  
Tobias Grossner ◽  
Uwe Haberkorn ◽  
Tobias Gotterbarm

First-line analgetic medication used in the field of musculoskeletal degenerative diseases, like Nonsteroidal anti-inflammatory drugs (NSAIDs), reduces pain and prostaglandin synthesis, whereby peptic ulcers are a severe adverse effect. Therefore, proton pump inhibitors (PPI) are frequently used as a concomitant medication to reduce this risk. However, the impact of NSAIDs or metamizole, in combination with PPIs, on bone metabolism is still unclear. Therefore, human mesenchymal stem cells (hMSCs) were cultured in monolayer cultures in 10 different groups for 21 days. New bone formation was induced as follows: Group 1 negative control group, group 2 osteogenic differentiation media (OSM), group 3 OSM with pantoprazole (PAN), group 4 OSM with ibuprofen (IBU), group 5 OSM with diclofenac (DIC), group 6 OSM with metamizole (MET), group 7 OSM with ibuprofen and pantoprazole (IBU + PAN), group 8 OSM with diclofenac and pantoprazole (DIC + PAN), group 9 OSM with metamizole and pantoprazole (MET + PAN) and group 10 OSM with diclofenac, metamizole and pantoprazole (DIC + MET + PAN). Hydroxyapatite content was evaluated using high-sensitive radioactive 99mTc-HDP labeling. Within this study, no evidence was found that the common analgetic medication, using NSAIDs alone or in combination with pantoprazole and/or metamizole, has any negative impact on the osteogenic differentiation of mesenchymal stem cells in vitro. To the contrary, the statistical results indicate that pantoprazole alone (group 3 (PAN) (p = 0.016)) or diclofenac alone (group 5 (DIC) (p = 0.008)) enhances the deposition of minerals by hMSCS in vitro. There is an ongoing discussion between clinicians in the field of orthopaedics and traumatology as to whether post-surgical (pain) medication has a negative impact on bone healing. This is the first hMSC in vitro study that investigates the effects of pain medication in combination with PPIs on bone metabolism. Our in vitro data indicates that the assumed negative impact on bone metabolism is subsidiary. These findings substantiate the thesis that, in clinical medicine, the patient can receive every pain medication needed, whether or not in combination with PPIs, without any negative effects for the osteo-regenerative potential.


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