MiR-4262 regulates differentiation and osteogenesis of human periodontal stem cells by targeting suppressor of cytokine signaling 4

Periodontitis, as a chronic inflammatory disease, remains unsolved, and the pathogenesis of this disease has notbeen fully elucidated. In this study, the effect of miR-4262 was investigated in tumor necrosis factor-α (TNF-α) inducedhuman periodontal stem cells (hPDLSCs) for the first time. The gene expression involved in this study was determinedusing polymerase chain reaction (PCR), the expressions of relevant proteins were determined by western blot analysis,and the levels of IL-1β, IL-6, and MCP-1 were estimated by enzyme-linked immunosorbent assay (ELISA) assay. Theluciferase reporter assay was performed for verification of the target gene, alkaline phosphatase (ALP) activitydetection was used for differentiation capacity, and alizarin red staining assay was used for mineralization capacity.The inhibition of miRNA-4262, which resulted in the upregulation of suppressor of cytokine signaling 4 (SOCS4),showed protective effects, including anti-inflammation and promotional effects on osteogenesis as well asdifferentiation in TNF-α induced hPDLSCs. These results provided insights into the roles of miRNAs in regulatingthe inflammatory response, differentiation, and osteogenesis in hPDLSCs, which may promote the understanding ofthe mechanisms of periodontitis and find out a better therapeutic application.     

Effects of docosahexaenoic acid or arachidonic acid supplementation on the behavior of cardiomyocytes derived from human pluripotent stem cells

Background: Human heart changes its energetic substrates from lactate and glucose to fatty acids during the neonatal period. Noticing the lack of fatty acids in media for the culture of cardiomyocytes derived from human pluripotent stem cells (hiPS-CM), researchers have supplemented mixtures of fatty acids to hiPS-CM and reported the enhancement in the maturation of hiPS-CM. In our previous studies, we separately supplemented two polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA) or arachidonic acid (AA), to rat fetal cardiomyocytes and found that the supplementations upregulated the expressions of mRNAs for cardiomyocyte differentiation, fatty acid metabolism, and cellular adhesion. The enhancement in cellular contractility was attributed to the improvement in intercellular connection rather than a direct enhancement of the contractile force. Methods: This study reports the successive results of the effects of DHA or AA supplementation on hiPS-CM. In addition to the contractile force and mRNA measurements used in the previous study, we further investigated the effect of different cellular aggregations on the contractile force output by means of finite element analysis, measured glucose and fatty acids metabolites, and assessed cTNT and MLC2v expressions through immunofluorecsence evaluation. Results: It showed that the sole supplementation of albumin-conjugated DHA or AA can be taken up by hiPS-CM without other uptake-enhancing factors, and the supplementations may activate the CD36_­ERRγ metabolic pathway. DHA or AA supplementation increased the cellular contractile ratio on collagen gels and AA supplementation stimulated hiPS-CM aggregation to form cellular clusters. The enhancement effect on the hiPS-CM contractile force was modest since the increase in contractile force was not significant. AA supplementation was more effective than DHA supplementation because it significantly upregulated mRNA expressions of P300 and CD36. However, finite element analysis showed that the formation of clusters on a collagen gel attenuated the contractile force exerted by the gel on its surroundings. Conclusion: DHA and AA, as having been supplemented in infant formulas, have no direct and significant enhancement effect on the performance of the hiPS-CM when they were supplemented individually, although they were able to enter the cellular metabolic system. The AA supplementation showed some auxiliary effect on the maturation of hiPS-CM, which is worthy of further investigation under the consideration of membrane composition alteration and remodeling of membrane molecules.