RESUMO
<p><b>OBJECTIVE</b>To develop HDV as a vehicle to deliver hammerhead ribozyme into hepatocytes, the effects of modified HDV was assessed on the activity of embedded hammerhead ribozyme in vitro and in vivo.</p><p><b>METHODS</b>In vitro activity of ribozyme or HDV-driven ribozyme was assessed by incubating with the [alpha-32 P]-ATP labeled HBV RNA substrates at different temperature. Huh-7 cells were cotransfected with ribozyme or HDV-ribozyme chimera and HBV genome, by which inhibition of ribozymes on HBV transcription in vivo were examined.</p><p><b>RESULTS</b>The results indicated that both temperature and secondary structure influenced the cleavage activity of HDV-driven ribozyme significantly. When the factors were eliminated, the HDV-driven ribozyme could act as well as its counterpart naked ribozyme. While in cultured cells the HDV-driven ribozyme had higher inhibition to HBV gene expression than that of ribozyme alone.</p><p><b>CONCLUSION</b>The results demonstrated that HDV may weaken the activity of embedded ribozyme in vitro, but make it enhanced in cultured cells. Thus, this study could provide a useful evidence to develop HDV as vector for liver-special delivery of ribozyme to against chronic HBV infection.</p>
Assuntos
Humanos , Sequência de Bases , Linhagem Celular Tumoral , Genoma Viral , Vírus Delta da Hepatite , Genética , Dados de Sequência Molecular , Plasmídeos , Genética , Estrutura Secundária de Proteína , RNA Catalítico , Química , Genética , Metabolismo , RNA Viral , Genética , Metabolismo , Relação Estrutura-Atividade , Especificidade por Substrato , Temperatura , TransfecçãoRESUMO
Hepatocyte growth factor (HGF) is a multifunctional growth factor which is a heterodimeric glycoprotein molecule. There are three truncated HGF variants: NK1, NK2, NK4. The structure of the promoter of HGF is very complicated, and the expression of HGF is regulated by various factors and regulatory elements. Because of the importance of HGF to human body, the genetic engineering expression and gene therapy investigation of HGF are being done.
Assuntos
Animais , Humanos , Regulação da Expressão Gênica , Terapia Genética , Variação Genética , Fator de Crescimento de Hepatócito , Química , Genética , Regiões Promotoras Genéticas , Engenharia de Proteínas , Splicing de RNA , GenéticaRESUMO
Overexpression of procollagen gene can cause the extraordinary increase of collagen's synthesis and therefore lead to the keloid and hypertrophic scar. To utilize ribozyme to suppress the expression of procollagen genes, a eukaryotic expression recombinant plasmid containing a dual-ribozyme gene against alpha 1 (I) and alpha 1 (III) procollagen genes was constructed. The ribozyme from in vitro transcription was incubated with target transcripts from recombinant plasmids which separately contained the fragments of the second exons of pro alpha 1 (I) and pro alpha 1 (III) collagen genes under various experimental conditions. The results showed that the dual-ribozyme could efficiently catalyze the specific cleavage of the target RNAs at 37 degrees C, 42 degrees C, 50 degrees C and Mg2+ concentration from 10 mmol/L to 20 mmol/L. This work provided a basis for further study on the ribozyme to suppress the expression of procollagen genes and control the cicatrization.