title: Protein kinase C delta (PKCδ) splice variant modulates senescence via hTERT in adipose-derived stem cells.
abstract: BACKGROUND
  Adipose-derived stem cells (ADSC) were isolated and characterized from lean and obese subjects. We previously reported that distinct differences were observed in differentiating lean and obese preadipocytes. Protein kinase C delta (PKCδ) is alternatively spliced and has important roles in apoptosis. PKCδI promotes apoptosis and PKCδVIII promotes survival. Our previous data indicated an increase in the survival kinase, PKCδVIII in ADSC derived from an obese donor. We also determined that obese adipocytes were resistant to apoptosis. Here, we determine the relationship between a survival kinase PKCδVIII and hTERT expression in adipose derived stem cells from a lean and obese subject.
  
  
  METHODS
  We evaluated the telomerase activity and human telomerase reverse transcriptase (hTERT) expression in lean and obese ADSC. The lean and obese ADSC were purchased as cryopreserved cells from ZenBio™ (Research Triangle Park, NC, USA). Analyses were performed using PRISM™ software and analyzed using two-tailed Student's t-test.
  
  
  RESULTS
  We observed an increase in telomerase in differentiating obese ADSC using western blot analysis. We determined the levels of hTERT splice variants. hTERT α+/β+ splice variant was increased after transfected of PKCδVIII. We next determined whether PKCδVIII over-expression affected the levels of telomerase. The results indicate an increase in telomerase with PKCδVIII over-expression.
  
  
  CONCLUSIONS
  Over-expression of PKCδVIII in lean ADSC substantially increased expression of hTERT and telomerase. The decreased senescence seen in obese ADSC may in part be attributed to PKCδVIII. Obese ADSC undergo lower senescence and may have increased growth potential. These results propose a larger epigenetic modification in obese ADSC compared to lean ADSC.
authors.affiliation: 1 James A Haley Veterans Hospital, Tampa, FL, USA ; 2 Department of Molecular Medicine and 3 Surgery, University of South Florida, Tampa, FL, USA.
authors.forename: Gay
authors.initials: G
authors.lastname: Carter
authors.affiliation: 1 James A Haley Veterans Hospital, Tampa, FL, USA ; 2 Department of Molecular Medicine and 3 Surgery, University of South Florida, Tampa, FL, USA.
authors.forename: Rekha
authors.initials: R
authors.lastname: Patel
authors.affiliation: 1 James A Haley Veterans Hospital, Tampa, FL, USA ; 2 Department of Molecular Medicine and 3 Surgery, University of South Florida, Tampa, FL, USA.
authors.forename: André
authors.initials: A
authors.lastname: Apostolatos
authors.affiliation: 1 James A Haley Veterans Hospital, Tampa, FL, USA ; 2 Department of Molecular Medicine and 3 Surgery, University of South Florida, Tampa, FL, USA.
authors.forename: Michel
authors.initials: M
authors.lastname: Murr
authors.affiliation: 1 James A Haley Veterans Hospital, Tampa, FL, USA ; 2 Department of Molecular Medicine and 3 Surgery, University of South Florida, Tampa, FL, USA.
authors.forename: Denise R
authors.initials: DR
authors.lastname: Cooper
authors.affiliation: 1 James A Haley Veterans Hospital, Tampa, FL, USA ; 2 Department of Molecular Medicine and 3 Surgery, University of South Florida, Tampa, FL, USA.
authors.forename: Niketa A
authors.initials: NA
authors.lastname: Patel
keywords: Adipose-derived stem cells (ADSC); alternative splicing; human telomerase reverse transcriptase (hTERT); obesity; protein kinase C delta (PKCδ)