Gangliosides play important roles in the control of several biological processes, including proliferation and transmembrane signaling. In this study, we demonstrate the effect of ganglioside GM1 on the proliferation of mouse induced pluripotent stem cells (miPSCs). The proliferation rate of miPSCs was lower than in mouse embryonic stem cells (mESCs). Fluorescence activated cell sorting analysis showed that the percentage of cells in the G2/M phase in miPSCs was lower than that in mESCs. GM1 was expressed in mESCs, but not miPSCs. To confirm the role of GM1 in miPSC proliferation, miPSCs were treated with GM1. GM1-treated miPSCs exhibited increased cell proliferation and a larger number of cells in the G2/M phase. Furthermore, phosphorylation of mitogen-activated protein kinases was increased in GM1-treated miPSCs. [BMB Reports 2012; 45(12): 713-718]

Gangliosides are ubiquitous components of the membranes of mammalian cells that are thought to play important roles in various cell functions such as cell-cell interaction, cell adhesion, cell differentiation, growth control, and signaling. However, the role that gangliosides play in the immune rejection response after xenotransplantation is not yet clearly understood. In this study, the regulatory effects of human leukocytes on ganglioside expression in primary cultured micro-pig aortic endothelial cells (PAECs) were investigated. To determine the impact of human leukocytes on the expression of gangliosides in PAECs, we performed high-performance thin layer chromatography (HPTLC) in PAECs incubated with FBS, FBS containing human leukocytes, human serum containing human leukocytes, and FBS containing TNF-α. Both HPTLC and immunohistochemistry analyses revealed that PAECs incubated with FBS predominantly express the gangliosides GM3, GM1, and GD3. However, the expression of GM1 significantly decreased in PAECs incubated for 5 h with TNF-α (10 ng/mL), 10% human serum containing human leukocytes, and 10% FBS containing human leukocytes. Taken together, these results suggest that human leukocytes induced changes in the expression profile of ganglioside GM1 similar to those seen upon treatment of PAECs with TNF-α. This finding may be relevant for designing future therapeutic strategies intended to prolong xenograft survival.

An epithelial cell adhesion molecule (EpCAM) was selectively expressed in human colorectal carcinoma. Treatment with plant-derived anti-EpCAM mAb (mAbP CO17-1A) and RAW264.7 cells inhibited cell growth in the human colorectal cancer cell line SW620. In SW620 treated with mAbP CO17-1A and RAW264.7 cells, expression of p53 and p21 increased, whereas the expression of G1 phase-related proteins, cyclin D1, CDK4, cyclin E, and CDK2, decreased, similar to mammalian-derived mAb (mAbM) CO17-1A. Similar to mAbM CO17-1A, treatment with mAbP CO17-1A and RAW264.7 cell decreased the expression of anti-apoptotic protein, Bcl-2, but the expression of pro-apoptotic proteins Bax, TNF-α, caspase-3, caspase-6, caspase-8 and caspase-9, increased. Cells treated with mAbP CO17-1A and RAW264.7 cells expressed metastasis-related gangliosides, GM1 and GD1a, similar to mAbM CO17-1A. These results suggest that mAbP CO17-1A is as effective on anti-cancer activity as mAbM CO17-1A.

The accelerated cooling rate associated with vitrification reduces injuries attributed to cryopreservation and improves the post-freezing developmental competence of vitrified embryos. In this study, embryos were vitrified and warmed and morphologically evaluated for their development to blastocysts. Survival rates between the fresh (96.7%93.8%) and vitrified embryos (90.7%95.1%) did not differ significantly (P ! 0.05). The mitochondrial membrane potential of fresh control cells measured by 5,5?,6,6?-tetrachloro-1,1?,3,3?-tetraethylbenzimidazolyl carbocyanide iodide staining was similar to that of cryoprotected and vitrified embryos. Mitochondrial staining with rhodamine 123 did not differ among the fresh, cryoprotected, and vitrified embryos. Moreover, the distribution of H 2 O 2 , assessed by 2?,7?-dichlorodihydrofluorescein diacetate staining, did not differ among the groups. The results showed that the developmental rate did not differ significantly among the fresh (87.8%911.3%), cryoprotected (83.2%97.6%), and vitrified 2-cell embryos (75.8%914.2%). The mean number of the inner cell mass (ICM), trophectoderm (TE), and apoptotic cells was counted and statistically compared, and although the number of ICM and TE was decreased in the cryoprotected and vitrified embryos, there were no significant differences among the groups (P ! 0.05). During the cultivation period, randomly selected blastocysts from each group were stained using either 4?,6-diamidino-2phenylindole and bisbenzimide or the terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling technique. The incidence of apoptosis appeared to be almost identical in all the groups. Droplet vitrification could subsequently lead to high survival and developmental rates of cryopreserved mouse embryos.

(2013) Effect of gangliosides on LPS stimulation and nitric oxide release in porcine kidney cell line PK15, Animal Cells and Systems, 17:5, 341-347, DOI: 10.1080/19768354.2013.839957 To link to this article: https://doi.org/10. 1080/19768354.2013 Gangliosides, which are glycosphingolipids containing sialic acid, play important regulatory roles in cell proliferation and adhesion, survival and immunosuppressive activity. In this study, we investigated whether gangliosides can affect cell viability in the porcine kidney (PK) cell line, PK15, when stimulated with lipopolysaccharide (LPS). As the amount of LPS that PK15 cells were treated with was increased, the cell proliferation decreased, whereas nitric oxide (NO) production increased. High-performance thin-layer chromatography (HPTLC) and immunofluorescence analyses showed that GM3 and GM2 ganglioside expression significantly decreased in LPS-stimulated PK15 compared to unstimulated PK15. UDP-glucose ceramide glucosyltransferase (Ugcg), which catalyzes the initial step in the glycosphingolipid biosynthesis pathway, was knocked-down in PK15 by using short hairpin RNA (shRNA). Western blot and HPTLC analyses showed that the Ugcg protein expression decreased and the ganglioside expression decreased in the Ugcg-knockdown (UKD) PK15. There was a greater decrease in cell proliferation in LPS-stimulated UKD PK15 cells than in LPS-stimulated PK15 cells without the UKD. However, the increase in NO release was greater in LPS-stimulated UKD PK15 cells than in LPS-stimulated PK15 cells without the UKD. These findings suggest that gangliosides may interact with components of the inflammatory response pathway and, thus, are relevant for the design of future therapeutic strategies intended to prolong xenotransplantation.