当前位置： SCI文献检索 > JOURNAL OF CELLULAR PHYSIOLOGY期刊下所有文献 > Effects of cell culture time and bone matrix exposure on calmodulin content and ATP-dependent cell membrane acid transport in avian osteoclasts and macrophages.

Effects of cell culture time and bone matrix exposure on calmodulin content and ATP-dependent cell membrane acid transport in avian osteoclasts and macrophages.

Abstract：

:Osteoclasts mediate bone resorption by secretion at the site of bone attachment. This process depends on calmodulin concentrated at a specialized acid-secreting membrane. We hypothesized that increased calmodulin and bone attachment were required for acid secretion. We tested this by studying calmodulin, bone attachment, and membrane acid transport in osteoclasts and their precursor mononuclear cells. Osteoclasts and macrophages were isolated from medullary bone of hens; cell fractions were prepared after culturing cells with or without bone. Calmodulin was visualized by Western analysis; calmodulin mRNA was determined by Northern hybridization, and ATP-dependent membrane acid transport was assayed by acridine orange uptake. Calmodulin decreased in osteoclasts cultured without bone. Calmodulin in isolated macrophages was approximately 25% of osteoclast levels, but increased several fold by 5 days. Bone had no effect. Calmodulin mRNA was similar in osteoclasts with or without bone. However, only osteoclasts cultured with bone retained acid transport capacity. Macrophage calmodulin mRNA was not affected by bone, but increased three fold by day 5, paralleling protein production. Macrophages developed acid transport capacity at 3-5 days, but at lower levels than osteoclasts, and bone had no measurable effect. Chicken cells express 1.6 kb and inducible 1.9 kb calmodulin transcripts; in macrophages and osteoclasts, the 1.9 kb transcript predominated. We conclude that, following isolation, calmodulin levels decline in osteoclasts via a post-transcriptional mechanism. In cultured macrophages, by contrast, calmodulin mRNA, protein, and acid secretion increase with time independently of bone substrate, possibly reflecting differentiation in vitro. Increased calmodulin correlated with membrane acid transport capacity in both cell types. The macrophage findings indicate that stimuli other than bone influence acid transport capacity in this family of cells.

journal_name

J Cell Physiol

journal_title

Journal of cellular physiology

authors

Williams JP,Dong SS,Whitaker CH,Jordan SE,Blair HC

doi

10.1002/(SICI)1097-4652(199612)169:3<411::AID-JCP1

subject

Has Abstract

pub_date

1996-12-01 00:00:00

pages

411-9

issue

eissn

0021-9541

issn

1097-4652

pii

10.1002/(SICI)1097-4652(199612)169:3<411::AID-JCP1

journal_volume

169

pub_type

杂志文章

在线工具

Effects of cell culture time and bone matrix exposure on calmodulin content and ATP-dependent cell membrane acid transport in avian osteoclasts and macrophages.