摘要
Physiologic roles of PTHrP remain elusive,but some have implied a role of growth and differentiation.Since intestinal epithelial cell show orderly growth and differentiation as they proliferate in the crypt and migrate to the villus tip,we asked whether they might exhibit differences in expression of mRNA for either PTHrP or its receptor.AT/PCR was used to generate cDNA probe for either PTHrP or the PTH/PTHrP receptor.Total RNA was prepared from epithelial cells isolated form various region of rat gut and epithelial cell lines.derived from rat crypt(IEC-6)and human colon(LoVo)as wellas cell fractions taken sequentially along the villus-crypt axis of rat jejunum.The 1.6kb mRNA for PTHrP was detected in epithelia from all regions of rat gut(duodenum,jejunum,ileum,colon),in all fractions along the iejnnal villus tipcrypt axis,and in both cell lines.Likewise mRNA for the PTH/PTHrP receptor also was expressed,lbeit at lower level,in all regions,along the villus,and in both cell lines. Interestingly,while in kidney(positive control)two transcripts(1.5 & 2.4 kb)were detected as other reported,in intestinal epithelia and cell lines,only 1.skb transcript was evident.We conclude that mRNAs for both PTHrP and PTH/PTHrP receptor are expressed throughout the gut and that no obvious pattern of expre.ssion emerges from examining epithelia or cell lines representing different stage of differentiation. The role of PTHrP in gut epithelia remains to be defined.
Physiologic roles of PTHrP remain elusive,but some have implied a role of growth and differentiation.Since intestinal epithelial cell show orderly growth and differentiation as they proliferate in the crypt and migrate to the villus tip,we asked whether they might exhibit differences in expression of mRNA for either PTHrP or its receptor.AT/PCR was used to generate cDNA probe for either PTHrP or the PTH/PTHrP receptor.Total RNA was prepared from epithelial cells isolated form various region of rat gut and epithelial cell lines.derived from rat crypt(IEC-6)and human colon(LoVo)as wellas cell fractions taken sequentially along the villus-crypt axis of rat jejunum.The 1.6kb mRNA for PTHrP was detected in epithelia from all regions of rat gut(duodenum,jejunum,ileum,colon),in all fractions along the iejnnal villus tipcrypt axis,and in both cell lines.Likewise mRNA for the PTH/PTHrP receptor also was expressed,lbeit at lower level,in all regions,along the villus,and in both cell lines. Interestingly,while in kidney(positive control)two transcripts(1.5 & 2.4 kb)were detected as other reported,in intestinal epithelia and cell lines,only 1.skb transcript was evident.We conclude that mRNAs for both PTHrP and PTH/PTHrP receptor are expressed throughout the gut and that no obvious pattern of expre.ssion emerges from examining epithelia or cell lines representing different stage of differentiation. The role of PTHrP in gut epithelia remains to be defined.
