RESUMO
Our understanding of system dynamics of mixed cell populations in whole organisms has benefited from the advent of individual cell marking by nonarrayed DNA barcodes subsequently analyzed by high-throughput DNA sequencing. However, key limitations include statistical biases compromising quantification and the lack of applicability to deconvolute individual cell fate in vivo after pooling single cells differentially exposed to different conditions ex vivo. Here, we have derived an arrayed lentiviral library of DNA barcodes and obtained a proof-of-concept of its resolving capacity by quantifying hematopoietic regeneration after engraftment of mice with genetically modified autologous cells. This method has helped clarify and bridge the seemingly opposed clonal-succession and continuous-recruitment models of hematopoietic stem cell behavior and revealed that myeloid-lymphoid biases are common occurrences in steady-state hematopoiesis. Arrayed lentiviral barcoding should prove a versatile and powerful approach to deconvolute cell dynamics in vivo with applications in hematology, embryology, and cancer biology.
Assuntos
Células-Tronco Hematopoéticas/fisiologia , Lentivirus/genética , Animais , Rastreamento de Células/métodos , Código de Barras de DNA Taxonômico , Vetores Genéticos , Células HEK293 , Transplante de Células-Tronco Hematopoéticas , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , FenótipoRESUMO
A series of compounds derived from naturally occurring flavonoids and synthetic analogs have been evaluated on cell lines overexpressing the wild-type breast cancer resistance protein (BCRP/ABCG2) half-transporter. Human ABCG2-transfected cells were used for screening their inhibitory activity. Five new natural compounds obtained from Morus mesozygia Stapf and one synthetic chromone, comprising a flavonoidic scaffold, were also evaluated. Based on the results obtained with a total of 34 compounds, a 3D linear solvation energy QSAR was investigated by VolSurf descriptors of molecular-interaction fields (MIFs) related to hydrophobic-interaction forces, polarisability and hydrogen-bonding capacity. Accuracy of the constructed 3D-QSAR model was attested by a correlation coefficient r(2) of 0.77. Shape parameters and hydrophobicity were revealed to be major physicochemical parameters responsible for the inhibition activity of flavonoid derivatives and synthetic analogs towards ABCG2, whereas hydrogen-bond donor capacity appeared highly unfavorable.
