In Vitro Erythroid Differentiation and Lentiviral Knockdown in Human CD34+ Cells from Umbilical Cord Blood

Human induced pluripotent stem cell line banking for the production of rare blood type erythrocytes

Background

The in vitro production of mature human red blood cells (RBCs) from induced pluripotent stem cells (iPSCs) has been the focus of research to meet the high demand for blood transfusions. However, limitations like high costs and technological requirements restrict the use of RBCs produced by iPSC differentiation to specific circumstances, such as for patients with rare blood types or alloimmunized patients. In this study, we developed a detailed protocol for the generation of iPSC lines derived from peripheral blood of donors with O D-positive blood and rare blood types (D–and Jr(a-)) and subsequent erythroid differentiation.

Methods

Mononuclear cells separated from the peripheral blood of O D-positive and rare blood type donors were cultured to produce and expand erythroid progenitors and reprogrammed into iPSCs. A 31-day serum-free, xeno-free erythroid differentiation protocol was used to generate reticulocytes. The stability of iPSC lines was confirmed with chromosomal analysis and RT-PCR. Morphology and cell counts were determined by microscopy observations and flow cytometry.

Results

Cells from all donors were successfully used to generate iPSC lines, which were differentiated into erythroid precursors without any apparent chromosomal mutations. This differentiation protocol resulted in moderate erythrocyte yield per iPSC.

Conclusions

It has previously only been hypothesized that erythroid differentiation from iPSCs could be used to produce RBCs for transfusion to patients with rare blood types or who have been alloimmunized. Our results demonstrate the feasibility of producing autologous iPSC-differentiated RBCs for clinical transfusions in patients without alternative options.

miR-145-5p inhibits tumor occurrence and metastasis through the NF-κB signaling pathway by targeting TLR4 in malignant melanoma

Compelling evidence shows that deregulated microRNAs (miRNAs) are important regulators in the progression of melanoma. miR-145-5p has been suggested to exhibit antitumorigenic activity in melanoma. However, the molecular mechanism underlying the biological activity of miR-145-5p in melanoma remains to be further understood. Herein, quantitative real-time polymerase chain reaction was used to examine the miR-145-5p expression in malignant melanoma tissues and cells. The interaction between miR-145-5p and toll-like receptor 4 (TLR4) was explored by bioinformatics analyses, luciferase reporter assay, and Western blot. The effects of miR-145-5p or combined with TLR4 on cell proliferation, colony formation, migration, and invasion abilities were investigated by (4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, colony formation, wound healing, and transwell assays, respectively. The melanoma xenograft tumor models were established to determine the biological activity of miR-145-5p in melanoma in vivo. In addition, the changes of the nuclear factor kappa B (NF-κB) pathway were analyzed by detecting the NF-κB activity and the NF-κB p65 protein level. We observed that the miR-145-5p expression was underexpressed in melanoma tissues and cells. miR-145-5p suppressed the TLR4 expression by binding to its 3'untranslated region in melanoma cells. Moreover, TLR4 overexpression abolished the inhibition of cell proliferation, colony formation, migration, and invasion abilities induced by miR-145-5p in melanoma cells. Meanwhile, miR-145-5p was confirmed to restrain melanoma tumor growth in vivo by targeting TLR4. Furthermore, miR-145-5p overexpression inactivated the NF-κB pathway in melanoma in vitro and in vivo, which was reversed by TLR4 overexpression. We concluded that miR-145-5p hindered the occurrence and metastasis of melanoma cells in vitro and in vivo by targeting TLR4 via inactivation of the NF-κB pathway.