Flow cytometric quantification of apoptotic and proliferating cells applying an improved method for dissociation of spheroids

Unraveling the Mechanisms of Vestibular Neuron Formation from Human Induced Pluripotent Stem Cells

The development of in vitro models that accurately recapitulate the complex cellular and molecular interactions of the inner ear is crucial for understanding inner ear development, function, and disease. In this study, we utilized a customized microfluidic platform to generate human induced pluripotent stem cell (hiPSC)-derived three-dimensional otic sensory neurons (OSNs). hiPSC-derived otic neuronal progenitors (ONPs) were cultured in hydrogel-embedded microfluidic channels over a 40-day period. Careful modulation of Wnt and Shh signaling pathways was used to influence dorsoventral patterning and direct differentiation toward a vestibular neuron lineage. After validating the microfluidic platform, OSN spheroid transcription factor and protein expression were assessed using real-time quantitative polymerase chain reaction (RT-qPCR), immunocytochemistry, and flow cytometry. The results demonstrated the successful differentiation of hiPSCs into ONPs and subsequent divergent differentiation into vestibular neuronal lineages, as evidenced by the expression of characteristic markers. Overall, our microfluidic platform provides a physiologically relevant environment for the culture and differentiation of hiPSCs, offering a valuable tool for studying inner ear development, disease and drug screening, and regenerative medicine applications.

Regulation of cytokinesis and necroptosis pathways by diosgenin inhibits the proliferation of NCI-H460 lung cancer cells

Aim Overcoming resistance to apoptosis and antimitotic chemotherapy is crucial for effective treatment of lung cancer. Diosgenin (DG), a promising phytochemical, can regulate various molecular pathways implicated in tumor formation and progression. However, the precise biological activity of DG in lung cancer remains unclear. This study aimed to investigate the antiproliferative activity of DG in NCI-H460 lung carcinoma cells to explore the underlying antimitotic mechanisms and alternative cell death pathways.

MATERIALS AND METHODS

In a 2D culture system, we analyzed cell viability, multinucleated cell frequency, cell concentration, cell cycle changes, cell death induction, intracellular reactive oxygen species (ROS) production, and nuclear DNA damage, particularly in relation to target gene expression. We also evaluated the antiproliferative activity of DG in a 3D culture system of spheroids, assessing volume changes, cell death induction, and inhibition of proliferation recovery and clonogenic growth.

KEY FINDINGS

DG reduced cell viability and concentration while increasing the frequency of cells with multiple nuclei, particularly binucleated cells resulting from daughter cell fusion. This effect was associated with genes involved in cytokinesis regulation (RAB35, OCRL, BIRC5, and AURKB). Additionally, DG-induced cell death was linked to necroptosis, as evidenced by increased intracellular ROS production and RIPK3, MLKL, TRAF2, and HSPA5 gene expression. In tumor spheroids, DG increased spheroid volume, induced cell death, and inhibited proliferation recovery and clonogenic growth.

SIGNIFICANCE

Our study provides new insights into the biological activities of DG in lung cancer cells, contributing to the development of novel oncological therapies.

Chitosan versus Carboxymethyl Chitosan Cryogels: Bacterial Colonization, Human Embryonic Kidney 293T Cell Culturing and Co-Culturing

The potential of chitosan and carboxymethyl chitosan (CMC) cryogels cross-linked with diglycidyl ether of 1,4-butandiol (BDDGE) and poly(ethylene glycol) (PEGDGE) have been compared in terms of 3D culturing HEK-293T cell line and preventing the bacterial colonization of the scaffolds. The first attempts to apply cryogels for the 3D co-culturing of bacteria and human cells have been undertaken toward the development of new models of host-pathogen interactions and bioimplant-associated infections. Using a combination of scanning electron microscopy, confocal laser scanning microscopy, and flow cytometry, we have demonstrated that CMC cryogels provided microenvironment stimulating cell-cell interactions and the growth of tightly packed multicellular spheroids, while cell-substrate interactions dominated in both chitosan cryogels, despite a significant difference in swelling capacities and Young's modulus of BDDGE- and PEGDGE-cross-linked scaffolds. Chitosan cryogels demonstrated only mild antimicrobial properties against Pseudomonas fluorescence, and could not prevent the formation of Staphylococcus aureus biofilm in DMEM media. CMC cryogels were more efficient in preventing the adhesion and colonization of both P. fluorescence and S. aureus on the surface, demonstrating antifouling properties rather than the ability to kill bacteria. The application of CMC cryogels to 3D co-culture HEK-293T spheroids with P. fluorescence revealed a higher resistance of human cells to bacterial toxins than in the 2D co-culture.