title: Porcine placenta hydrolysates regulate calcium disturbance in MC3T3-E1 osteoblastic cells.
abstract: BACKGROUND
  In bone metabolism, Ca(2+) disturbance and oxidative damage are the main biochemical factors related to pathology. Osteoblasts are bone-forming cells that also control bone endocrinology. Endocrine hormones and proteins are matured, folded, and secreted in the endoplasmic reticulum (ER). ER stress has emerged as a new pathological mechanism to explain bone disturbance. Here we studied the role of porcine placenta hydrolysates (PPHs) in the regulation of ER stress.
  
  
  METHODS
  Cell viability was determined in vitro using trypan blue dye exclusion. ER stress and apoptosis were evaluated using immunoblotting and a caspase kit. The fluorescent Ca(2+)-binding dye Fura-2/AM was used to measure changes in intracellular Ca(2+) ([Ca(2+)]i). ROS levels, NADPH oxidase activity, and superoxide dismutase (SOD) activity were also measured.
  
  
  RESULTS
  PPHs protected MC3T3-E1 osteoblastic cells against thapsigargin (Tg)-induced ER stress. Moreover, PPHs regulated caspase-12 and -3 activities, thereby protecting against cell death, and also regulated Tg-induced Ca(2+) release. The Ca(2+) chelator BAPT/AM also regulated caspase-12 and -3 activities and prevented Ca(2) stress-induced cell death. In the presence of PPHs or BAPTA/AM, Ca(2+)-related ROS were also regulated, as demonstrated by alterations in NADPH oxidase and SOD activity.
  
  
  CONCLUSIONS
  PPHs appear to regulate bone metabolism disturbance by controlling Ca(2+) concentrations, and thus ER stress and ROS, in osteoblasts cultured in vitro.
authors.affiliation: Department of Pharmacology and New Drug Development Institute, Medical School, Chonbuk National University, Jeonju, 560-182, Republic of Korea.
authors.forename: Hwa-Young
authors.initials: HY
authors.lastname: Lee
authors.affiliation: Department of Dental Pharmacology, College of Dentistry, Wonkwang University, Iksan, 570-749, Republic of Korea.
authors.forename: Hyung-Ryong
authors.initials: HR
authors.lastname: Kim
authors.affiliation: CODEBIO CO., LTD, Busong 1gil 62, Jiksan-eup, Seobuk-gu, Cheonan, Chungnam, 331-815, Republic of Korea.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Pharmacology and New Drug Development Institute, Medical School, Chonbuk National University, Jeonju, 560-182, Republic of Korea.
authors.forename: Han-Jung
authors.initials: HJ
authors.lastname: Chae
authors.affiliation: Department of Obstetrics and Gynecology, Institute for Medical Sciences, Chonbuk National University Medical School, Jeonju, 560-182, Republic of Korea. obgyn2001@naver.com.
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001688:Biological Products / Q000494:pharmacology*; D020013:Calcium Signaling / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D005260:Female; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects*; D010920:Placenta / Q000737:chemistry*; D011247:Pregnancy; D013552:Swine
chemical_list: D001688:Biological Products
keywords: Calcium; ER stress; Osteoporosis; Oxidative damage; Porcine placenta hydrolysates