Methods for preparing populations of hematopoietic stem cells (HSCs), e.g., autologous and/or allogenic HSCs, using mechanical stretching or transient receptor potential cation channel-subfamily vanilloid member 4 (Trpv4) agonists, and methods of use of the HSCs in transplantation are provided. Specifically, the methods comprising providing a population cells comprising hemogenic endothelial (HE) cells, contacting the HE cells with an amount of an agonist of Trpv4; and/or subjecting the cells to cyclic 2-dimensional stretching, for a time and under conditions sufficient to stimulating endothelial-to-HSC transition. Further disclosed are methods of treating malignant or non-malignant hematologic, metabolic, or immune disorders comprising administering to a subject a therapeutically effective amount of HSCs obtained by the methods.
