RESUMEN

Although several synthetic hydrogels with defined stiffness have been developed to facilitate the proliferation and maintenance of human pluripotent stem cells (hPSCs), the influence of biochemical cues in lineage-specific differentiation and functional cluster formation has been rarely reported. Here, we present the application of Supragel, a supramolecular hydrogel formed by synthesized biotinylated peptides, for islet-like cluster differentiation. We observed that Supragel, with a peptide concentration of 5 mg/mL promoted spontaneous hPSCs formation into uniform clusters, which is mainly attributable to a supporting stiffness of ∼1.5 kPa as provided by the Supragel matrix. Supragel was also found to interact with the hPSCs and facilitate endodermal and subsequent insulin-secreting cell differentiation, partially through its components: the sequences of RGD and YIGSR that interacts with cell membrane molecules of integrin receptor. Compared to Matrigel and suspension culturing conditions, more efficient differentiation of the hPSCs was also observed at the stages 3 and 4, as well as the final stage toward generation of insulin-secreting cells. This could be explained by 1) suitable average size of the hPSCs clusters cultured on Supragel; 2) appropriate level of cell adhesive sites provided by Supragel during differentiation. It is worth noting that the Supragel culture system was more tolerance in terms of the initial seeding densities and less demanding, since a standard static cell culture condition was sufficient for the entire differentiation process. Our observations demonstrate a positive role of Supragel for hPSCs differentiation into islet-like cells, with additional potential in facilitating germ layer differentiation.

RESUMEN

There is growing evidence to suggest that scaffold of tissue can promote the tissue reparation. In this study, we investigate the effects of ovarian scaffolds on the reparation of cyclophosphamide (CPA) damaged mice ovaries. The mice were first administered with CPA, was then either transplanted an ovarian scaffold into each ovarian bursa for the experimental group (EG) or underwent sham surgery as the control (CG). To evaluate the extent of ovarian damage caused by CPA, a third group which did not undergo any treatment was included for the normal control (NG). Their ovaries were harvested for examination at day 30, 60, and 90 post CPA injection. We found that in EG, the number of all types of follicles in the ovaries remained almost the same throughout. The numbers of follicles were not significantly different from CG, except at day 60, where in CG the numbers of each type of follicle decreased to basal levels. The decrease in the number of ovarian follicles at day 60 in CG was mirrored by the significant increase in the number of apoptotic granulosa cells in the follicles, and was corroborated further by the basal levels of serum estradiol. Furthermore, we observed a significant decrease in collagen composition preceded by macrophage polarization, and elevation of inflammatory cytokine expression in the ovaries of the EG compared to the CG at day 60. We concluded that ovarian scaffolds can effectively protect primordial follicles from CPA-damage and promote the reparation of CPA-damaged ovaries. This research establishes a proof of concept for the future treatment of chemo-damaged ovaries.

Asunto(s)

RESUMEN

This study investigated the effect of recombinant human lactoferrin (rhLF) on the premature ovarian failure (POF) of rats. After cyclophosphamide treatments, the POF rats were divided into the following groups: normal control group (NC), low-dose group (LD), medium-dose group (MD) and high-dose group (HD) of rhLF. After drug administrations, the ovarian indexes and hormonal levels were detected. After follicle number count, the proliferation and apoptosis were analyzed with the expressions of genes related with oogenesis, reactive oxygen species (ROS) production and apoptosis detected, followed by the calculation of oxidative stress and protein expressions. After 4-hydroperoxy cyclophosphamide (4-HC) treatments, the effect of rhLF on the proliferation, ROS production and gene expressions of primary rat granulosa cells (GCs) cultured in vitro were detected. After mating, the fertilities of POF rats were recorded. The result showed that the rhLF administrations up-regulated the ovarian index with the number of developing follicles increased and the decreases of hormonal levels conferred. The Ki-67 intensities of the MD and HD groups were up-regulated with the Tunnel intensities decreased. The rhLF treatments significantly promoted the expression of oogenesis, antioxidant and anti-apoptosis related genes. The expression of Bax and Caspase 3 were decreased with the expression of Bcl-2 up-regulated after rhLF administrations. The in vitro treatments of rhLF effectively conferred the toxicity of 4-HC on primary rat GCs. The fertility assessment showed the rhLF treatments up-regulated the offspring's' folliculogenesis, which confirmed the ameliorative role of rhLF on the POF damages via the inhibition of ROS production in GCs.

Asunto(s)