scholarly journals Towards Tissue-Specific Stem Cell Therapy for the Intervertebral Disc: PPARδ Agonist Increases the Yield of Human Nucleus Pulposus Progenitor Cells in Expansion

Surgeries ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 92-104
Author(s):  
Xingshuo Zhang ◽  
Julien Guerrero ◽  
Andreas S. Croft ◽  
Katharina A.C. Oswald ◽  
Christoph E. Albers ◽  
...  

(1) Background: Low back pain (LBP) is often associated with intervertebral disc degeneration (IVDD). Autochthonous progenitor cells isolated from the center, i.e., the nucleus pulposus, of the IVD (so-called nucleus pulposus progenitor cells (NPPCs)) could be a future cell source for therapy. The NPPCs were also identified to be positive for the angiopoietin-1 receptor (Tie2). Similar to hematopoietic stem cells, Tie2 might be involved in peroxisome proliferator-activated receptor delta (PPARδ) agonist-induced self-renewal regulation. The purpose of this study was to investigate whether a PPARδ agonist (GW501516) increases the Tie2+ NPPCs’ yield within the heterogeneous nucleus pulposus cell (NPC) population. (2) Methods: Primary NPCs were treated with 10 µM of GW501516 for eight days. Mitochondrial mass was determined by microscopy, using mitotracker red dye, and the relative gene expression was quantified by qPCR, using extracellular matrix and mitophagy-related genes. (3) The NPC’s group treated with the PPARδ agonist showed a significant increase of the Tie2+ NPCs yield from ~7% in passage 1 to ~50% in passage two, compared to the NPCs vehicle-treated group. Furthermore, no significant differences were found among treatment and control, using qPCR and mitotracker deep red. (4) Conclusion: PPARδ agonist could help to increase the Tie2+ NPCs yield during NPC expansion.

2021 ◽  
pp. 56-69
Author(s):  
Derya Köseoğlu ◽  
Gülnur Take ◽  
Banu Aktaş Yılmaz ◽  
Erdal Kan ◽  
Nuri Çakır

Background: Osteoporosis is a metabolic skeletal disease with low bone mass and bone microarchitectural disorganization. Thiazolidinediones (TZD) increase insulin sensitivity through activation of peroxisome proliferator-activated receptor gamma (PPARγ). One of the most important side effects of this drugs is its effects on bone, especially in postmenopausal women. The purpose of this study was to evaluate the effect of diabetes mellitus (DM), insulin, and TZDs on bone in postmenopausal Wistar rats. Methods: Sixteen postmenopausal Wistar rats were divided into four groups: (i) control group, (ii) Streptozotocin-induced DM group without treatment, (iii) Streptozotocin-induced DM group with insulin therapy, and (iv) Streptozotocin-induced DM group receiving rosiglitazone. Pictures of the obtained samples were taken under computer-equipped photo-light microscope, and bone tissue ratios were calculated in an area of 1 mm2. In this area, trabecular thicknesses were measured from six randomly selected regions. In addition, femoral neck regions were determined by measuring the farthest distance. Results: Compared to the control group, trabecular thicknesses were decreased in the uncontrolled DM and rosiglitazone groups. In the rosiglitazone-treated group, trabecular thickness was decreased compared to the uncontrolled DM group. The histological examination of the bones showed that uncontrolled DM and rosiglitazone treatment negatively affected the osteoblast and osteocyte activity. Insulin-treated group had a similar histologic examination compared to the control group. Conclusion: Our study showed that DM had unfavorable effects on bones, and rosiglitazone further exerts this effect. However, the negative effect of DM may be neutralized with the use of insulin. Keywords: diabetes mellitus, bone, osteoporosis, bone histomorphometry, rosiglitazone, insulin, thiazolidinediones


Blood ◽  
2020 ◽  
Vol 136 (2) ◽  
pp. 235-246 ◽  
Author(s):  
Yuanting Chen ◽  
Jie Xiang ◽  
Fenghua Qian ◽  
Bastihalli T. Diwakar ◽  
Baiye Ruan ◽  
...  

Abstract Anemic stress induces stress erythropoiesis, which rapidly generates new erythrocytes to restore tissue oxygenation. Stress erythropoiesis is best understood in mice where it is extramedullary and occurs primarily in the spleen. However, both human and mouse stress erythropoiesis use signals and progenitor cells that are distinct from steady-state erythropoiesis. Immature stress erythroid progenitors (SEPs) are derived from short-term hematopoietic stem cells. Although the SEPs are capable of self-renewal, they are erythroid restricted. Inflammation and anemic stress induce the rapid proliferation of SEPs, but they do not differentiate until serum erythropoietin (Epo) levels increase. Here we show that rather than directly regulating SEPs, Epo promotes this transition from proliferation to differentiation by acting on macrophages in the splenic niche. During the proliferative stage, macrophages produce canonical Wnt ligands that promote proliferation and inhibit differentiation. Epo/Stat5-dependent signaling induces the production of bioactive lipid mediators in macrophages. Increased production of prostaglandin J2 (PGJ2) activates peroxisome proliferator-activated receptor γ (PPARγ)-dependent repression of Wnt expression, whereas increased production of prostaglandin E2 (PGE2) promotes the differentiation of SEPs.


2007 ◽  
Vol 97 (06) ◽  
pp. 988-997 ◽  
Author(s):  
Mihail Hristov ◽  
Denis Gümbel ◽  
Teresa Tejerina ◽  
Santiago Redondo ◽  
Christian Weber

SummaryEndothelial progenitor cells (EPCs) have been implicated in vascular repair and found to be functionally impaired in patients with diabetes. We evaluated the effects of the anti-diabetic drug pioglitazone on human EPC function and the involvement of PPAR-γ and TGF-β1. EPCs in culture were characterized at day 7 by the development of colony-forming units (CFUs) and flow cytometry assessment of differentiation marker (DiI-ac-LDL/lectin, KDR and CD31). Adhesion on fibronectin and fibrinogen in flow was analyzed as functional parameter. Treatment with pioglitazone for 72 hours increased the number of EPC-CFUs, DiI-ac-LDL+/lectin+, CD31+ and KDR+ EPCs at 1 μM but not at 10 μM. Since pioglitazone did not significantly alter proliferation and apoptosis in cultured EPCs, the increase in EPC number was most likely attributable to augmented adhesion and differentiation. Indeed, pioglitazone increased EPC adhesion in flow at 1 μM, an effect prevented by PPAR-γ and β2-integrin blockade. In contrast, pioglitazone did not promote EPC adhesion at 10 μM; however, increased adhesion became evident by co-incubation with a blocking TGF-β1 antibody. As determined by ELISA, pioglitazone induced a persistent increase in TGF-β1 secretion only at 10 μM when a significantly elevated expression of endoglin, the accessory receptor forTGF-β1, was also observed. Taken together, pioglitazone exerts biphasic effects on the function of isolated EPCs, causing a PPAR-γ-dependent stimulation at 1 μM and a TGF-β1-mediated suppression at 10 μM. These results may help to define optimal therapeutic doses of pioglitazone for improving endothelial dysfunction.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jun Ge ◽  
Quan Zhou ◽  
Junjie Niu ◽  
Yingjie Wang ◽  
Qi Yan ◽  
...  

Melatonin, a neuroendocrine hormone secreted by the pineal body, has a positive effect on intervertebral disc degeneration. The present study is aimed at investigating the biological role of melatonin in intervertebral disc degeneration and its underlying mechanism. A human nucleus pulposus cell (NPC) line was exposed to melatonin at different concentrations. Cell proliferation was measured by CCK-8 assay. Cell cycle and apoptosis were analyzed by flow cytometry. Western blot was performed to measure the protein expression of indicated genes. A rabbit model of intervertebral disc degeneration was established to detect the role and mechanism of melatonin on intervertebral disc degeneration. Our study showed that melatonin promoted NPC viability and inhibited cell arrest. Furthermore, melatonin treatment led to the upregulation of collagen II and aggrecan and downregulation of collagen X. Moreover, melatonin significantly elevated the activity of the ERK signaling pathway. Inhibition of the ERK1/2 signals reversed the role of melatonin in the regulation of NPCs both in vitro and in vivo. Melatonin increased NPC viability through inhibition of cell cycle arrest and apoptosis. Moreover, melatonin promoted the secretion of functional factors influencing the nucleus pulposus cell physiology and retarded cell degeneration. Our results suggest that melatonin activated the ERK1/2 signaling pathway, thereby affecting the biological properties of the intervertebral disc degeneration.


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