Modulation of the Dental Pulp Stem Cell Secretory Profile by Hypoxia Induction Using Cobalt Chloride

Abstract

The action of stem cells is mediated by their paracrine secretions which comprise the secretory profile. Various approaches can be used to modify the secretory profile of stem cells. Creating a hypoxic environment is one method. The present study aims to demonstrate the influence of CoCl2 in generating hypoxic conditions in a dental pulp stem cell (DPSCs) culture, and the effect of this environment on their secretory profile. DPSCs that were isolated from human permanent teeth were characterized and treated with different concentrations of CoCl2 to assess their viability by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and proliferation by a cell counting kit (CCK)-8 assay. The gene expression level of hypoxia-inducible factor 1-alpha (HIF-1α) was analyzed by quantitative real time polymerase chain reaction (qRT-PCR) to demonstrate a hypoxic environment. Comparative evaluation of the growth factors and cytokines were done by cytometric bead array. Gene expression levels of transcription factors OCT4 and SOX2 were analyzed by qRT-PCR to understand the effect of CoCl2 on stemness in DPSCs. DPSCs were positive for MSC-specific markers. Doses of CoCl2, up to 20 µM, did not negatively affect cell viability; in low doses (5 µM), it promoted cell survival. Treatment with 10 µM of CoCl2 significantly augmented the genetic expression of HIF-1α. Cells treated with 10 µM of CoCl2 showed changes in the levels of growth factors and cytokines produced. It was very evident that CoCl2 also increased the expression of OCT4 and SOX2, which is the modulation of stemness of DPSCs. A CoCl2 treatment-induced hypoxic environment modulates the secretory profile of DPSCs.

The Growth Factors and Cytokines of Dental Pulp Mesenchymal Stem Cell Secretome May Potentially Aid in Oral Cancer Proliferation

“…Apart from age, the cell culture conditions of the DPMSC affect its secretome profile and regenerative potential. In a recent study by Bhandi et al [ 14 ], the researchers were able to modulate the DPMSC secretome profile by induction of hypoxia through cobalt-chromium treatment to enhance its regenerative potential. Based on these observations, we hypothesized that the overall effect of the DPMSC relies on the levels of the growth factors and cytokine profile, which could be modulated to suit our needs.…”

Dental Pulp Stem Cells Derived From Adult Human Third Molar Tooth: A Brief Review

“…In addition, DPSCs express a variety of antigens associated with cell adhesion, growth factors, transcription regulation and multiple lineage-specific markers related to perivascular tissue, endothelium, immunogenic, neuronal and osteo/odontogenic tissues (Table 1). It is also noteworthy to mention that DPSCs express Major Histocompatibility Complex (MHC) class I antigens, but they do not express the immune co-stimulating molecules such as MHC class II antigen HLA-DR, CD40, CD80, and CD86 (Wada et al, 2009;Bhandi et al, 2021;Pilbauerova et al, 2021a). Kerkis et al, 2006;Atari et al, 2011;Liu L. et al, 2011;Ishkitiev et al, 2012;Kawanabe et al, 2012;Ponnaiyan et al, 2012;Huang et al, 2014;Wu et al, 2015;Ballini et al, 2019 Nanog Homeobox protein NANOG +++ Kerkis et al, 2006;Atari et al, 2011;Liu L. et al, 2011;Ishkitiev et al, 2012;Kawanabe et al, 2012;Ponnaiyan et al, 2012;Huang et al, 2014;Ballini et…”

“…In addition, DPSCs express a variety of antigens associated with cell adhesion, growth factors, transcription regulation and multiple lineage-specific markers related to perivascular tissue, endothelium, immunogenic, neuronal and osteo/odontogenic tissues ( Table 1 ). It is also noteworthy to mention that DPSCs express Major Histocompatibility Complex (MHC) class I antigens, but they do not express the immune co-stimulating molecules such as MHC class II antigen HLA-DR, CD40, CD80, and CD86 ( Wada et al, 2009 ; Bhandi et al, 2021 ; Pilbauerova et al, 2021a ).…”

The biological effect of cobalt chloride mimetic-hypoxia on nucleus pulposus cells and the comparability with physical hypoxia in vitro

“…CCK-8 is a colorimetric reaction-based assay that yields an orange formazan dye to an extent proportional with the cell number. The cell viability of NPCs was calculated by evaluating the absorbance at 450 nm on a spectrophotometer [20]. NPCs were seeded into 96-well plates (2000 cells/100 µL) and cultured in groups of normoxia, physical hypoxia (1% O 2 ) and CoCl 2 mimetic-hypoxia (50 µM, 100 µM, 200 µM, 300 µM, 400 µM).…”