Differential changes of CDK activities in glomeruli and tubules during the active DNA synthetic period after ischemic injury

Nephron. 2000 Nov;86(3):306-14. doi: 10.1159/000045786.

Abstract

The present study was designed to determine the spatial correlation among extent of DNA synthetic activity, expressions of G(1)/S phase cyclins, cyclin-dependent kinases (CDKs) and CIP/KIP family of CDK inhibitors (CKIs), and activities of G(1)/S phase CDKs in glomeruli and outer medullae of kidneys during the active regeneration period after ischemic injury. DNA synthetic activity was measured using [(3)H]-thymidine autoradiogram in the kidney sections. Cyclin, CDK, and CKI proteins were determined by Western blot analysis. CDK activities were determined by phosphorylation amount using specific substrate. The protein levels of cyclins (D1, D3, E, A) and activities of CDK4 and CDK2 were increased concomitant with the induction of DNA synthetic activity in outer medullae, but not in glomeruli, in adult kidneys during DNA synthetic period after ischemic injury. The p27(KIP1) protein, but not the p21(CIP1) protein, increased equally in total kidney, glomeruli, and outer medullae after ischemic injury. These results indicate that renal tubules have an active cyclin/CDK system, while glomeruli, do not have a cyclin/CDK system during active regeneration of kidneys after ischemic injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CDC2-CDC28 Kinases*
  • Cell Cycle Proteins*
  • Cyclin-Dependent Kinase 2
  • Cyclin-Dependent Kinase 4
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclin-Dependent Kinase Inhibitor p27
  • Cyclin-Dependent Kinases / metabolism*
  • Cyclins / metabolism
  • DNA / biosynthesis
  • G1 Phase / physiology
  • Ischemia / metabolism*
  • Ischemia / pathology
  • Kidney Glomerulus / blood supply
  • Kidney Glomerulus / enzymology*
  • Kidney Glomerulus / pathology
  • Kidney Tubules / blood supply
  • Kidney Tubules / enzymology*
  • Kidney Tubules / pathology
  • Male
  • Microtubule-Associated Proteins / metabolism
  • Proliferating Cell Nuclear Antigen / metabolism
  • Protein Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins*
  • Rats
  • Regeneration / physiology
  • S Phase / physiology*
  • Surgical Instruments
  • Thymidine / metabolism
  • Thymidine / pharmacology
  • Tritium
  • Tumor Suppressor Proteins*

Substances

  • Cdkn1a protein, rat
  • Cdkn1b protein, rat
  • Cell Cycle Proteins
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins
  • Microtubule-Associated Proteins
  • Proliferating Cell Nuclear Antigen
  • Proto-Oncogene Proteins
  • Tumor Suppressor Proteins
  • Tritium
  • Cyclin-Dependent Kinase Inhibitor p27
  • DNA
  • Protein Serine-Threonine Kinases
  • CDC2-CDC28 Kinases
  • Cdk2 protein, rat
  • Cdk4 protein, rat
  • Cyclin-Dependent Kinase 2
  • Cyclin-Dependent Kinase 4
  • Cyclin-Dependent Kinases
  • Thymidine