Down regulation of ITGA4 and ITGA5 genes after formation of 3D spherules by human Wharton's jelly stem cells (hWJSCs)

Impact of mesenchymal stem cell size and adhesion modulation on in vivo distribution: insights from quantitative PET imaging

BACKGROUND

Successful engraftment and localization of mesenchymal stem cells (MSCs) within target tissues are critical factors influencing their therapeutic efficacy for tissue repair and regeneration. However, the relative contributions of biophysical factors like cell size and adhesion capacity in regulating MSC distribution in vivo remain incompletely understood.

METHODS

Cell adhesion peptides and hanging drop method were used to modify the adhesive capacity and size of MSCs. To quantitatively track the real-time biodistribution of transplanted MSCs with defined size and adhesion profiles in living mice and rats, the non-invasive positron emission tomography (PET) imaging was applied.

RESULTS

Surface modification with integrin binding peptides like RGD, GFOGER, and HAVDI reduced MSC adhesion capacity in vitro by up to 43.5% without altering cell size, but did not significantly decrease lung entrapment in vivo. In contrast, culturing MSCs as 3D spheroids for 48 h reduced their cell diameter by 34.6% and markedly enhanced their ability to pass through the lungs and migrate to other organs like the liver after intravenous administration. This size-dependent effect on MSC distribution was more pronounced in rats compared to mice, likely due to differences in pulmonary microvessel diameters between species.

CONCLUSION

Our findings reveal that cell size is a predominant biophysical regulator of MSC localization in vivo compared to adhesion capacity, providing crucial insights to guide optimization of MSC delivery strategies for enhanced therapeutic efficacy.

Mir-122 upregulation and let-7f downregulation combination: The effects on hepatic differentiation of hiPSCs on the PCL-Gel-HA nanofibrous scaffold

Cell therapy and tissue engineering as promising candidates for the liver transplantation dilemma are of special interest. Induced pluripotent stem cells (iPSCs) are one of the best sources in this field, but their differentiation methods to hepatocytes have remained challenging. We transduced human iPSCs (hiPSCs) with miR-122 and off-let-7f (hiPSCs^{miR-122 + off-let-7f} ) to evaluate how they can differentiate hiPSCs to hepatocyte-like cells (HLCs) without any extrinsic growth factor. Additionally, we studied the effect of Poly ɛ-caprolactone-gelatin-hyaluronic acid (PCL-Gel-HA) nanofibrous scaffold as an extracellular matrix (ECM) simulator on differentiation improvement. Definitive endoderm markers (FOXA2 and SOX17), as well as hepatic markers (AFP, Albumin, CK18, HNF4α) expression, were significantly higher in hiPSCs^{miR-122 + off-let-7f} derived HLCs (hiPSCs-HLCs) compared to the control group (miR-scramble transduced hiPSCs: hiPSCs^scramble ). hiPSCs-HLCs indicated hepatocyte morphological characteristics and positive immunostaining for AFP, Albumin and HNF4α. Albumin and urea secretion were significantly higher in hiPSCs-HLCs than hiPSCs^scramble . Comparing these markers in the PCL-Gel-HA group with the tissue culture plate (TCP) group revealed that PCL-Gel-HA could improve differentiation towards HLCs significantly. Regarding our results, these microRNAs can be used to differentiate hiPSCs to the functional hepatocytes for disease modelling, drug screening and cell-based therapy in future studies.

Integrin α5/ITGA5 Promotes The Proliferation, Migration, Invasion And Progression Of Oral Squamous Carcinoma By Epithelial-Mesenchymal Transition

Background

Integrin signalling is involved in cell migration, invasion, proliferation and motility. Integrin α5/ITGA5 is a subunit of Integrin and contributes to the activation of Integrin signalling. The potential role of Integrin α5/ITGA5 in oral squamous cancer remains unknown. The aim of this study was to uncover the effect and mechanism of Integrin α5/ITGA5 in the progression of oral squamous carcinoma.

Method

TCGA database scanning, qRT-PCR, immunohistochemistry and Western blotting assays were used to detect the expression of Integrin α5/ITGA5 in tissues and cell lines. We established stable Integrin α5/ITGA5 overexpressing and Integrin α5/ITGA5 knockdown cell lines. We investigated the biological function and the underlying mechanism of Integrin α5/ITGA5 through a series of experiments.

Results

Integrin α5/ITGA5 was upregulated in cancer tissue, and its levels negatively correlated with the overall survival (OS) of patients. Integrin α5/ITGA5 promoted proliferation, migration and invasion in an oral squamous carcinoma cell line by EMT (epithelial-mesenchymal transition).

Conclusion

Integrin α5/ITGA5 promotes the proliferation, migration and invasion of oral squamous carcinoma.

Effects of minocycline and rapamycin in gamma-irradiated human embryonic stem cells-derived cerebral organoids

Radiation induces DNA and protein damage and free radical formation, effectively establishing cellular senescence in a variety of models. We demonstrate the effects of two known pleiotropic drugs following gamma radiation damage in neurosphere/cerebral organoid system based on human embryonic stem cells. mTORC1 repression by rapamycin prior to irradiation, or metabolic activation by minocycline after irradiation, partially rescues neuroepithelium integrity, neurite-growing capacity, ventricle formation and extracellular acidification rate as an integral measure of metabolic output. Cerebral organoid model thus provides valid and robust readouts for radiation studies in a complex 3D setting.