A Novel Human PTH Analog [Cys25]hPTH(1-34) Restores Bone Mass in Ovariectomized Mice.
Recently, an arginine-to-cysteine homozygous mutation at position 25 in mature PTH was reported in a Korean patient with hypoparathyroidism.



To clarify whether the high bone mass phenotype observed in this patient was related to the hypoparathyroidism itself or to chronic elevation of mutant PTH.



A series of in vitro and in vivo experiments were performed in MC3T3E1, ROS 17/2.8, and SAOS2 cells treated with human (h)PTH(1-34), Cys25hPTH(1-34), Ala1Cys25hPTH(1-34), and Bpa1Cys25hPTH(1-34). The peptides were then sc delivered to ovariectomized mice as daily single injections.



Compared with hPTH(1-34) and Ala1Cys25hPTH(1-34), treatment with Cys25hPTH(1-34) or Bpa1Cys25hPTH(1-34) resulted in decreases in the cAMP response and promoter-cAMP-response element luciferase reporter activity. Although the cAMP response was sustained with hPTH(1-34) in MC3T3E1 cells, such response was not observed with the other mutated peptides. Meanwhile, all PTH analogues exhibited ERK phosphorylation and cytoplasmic Ca++signals comparable with hPTH(1-34). On microcomputed tomography analyses, trabecular and cortical bone parameters improved after 6 weeks of respective treatments as follows: hPTH(1-34) (80 μg/kg) = Ala1Cys25hPTH(1-34) (80 μg/kg) = Cys25hPTH(1-34) (80 μg/kg) > Bpa1Cys25hPTH(1-34) (80 μg/kg) > hPTH(1-34) (40 μg/kg). The increment of RANKL to OPG mRNA ratio in the MC3T3E1 cells after 6 hours of treatment of Cys25hPTH(1-34), AL1Cys25hPTH(1-34), and Bpa1Cys25hPTH(1-34) was less than that was obtained after hPTH(1-34) treatment. On bone histomorphometric analysis, AL1Cys25hPTH(1-34) increased the bone formation rate in both trabecular and periosteal bones compared with the control group.



The high bone mass phenotype observed in this patient with hypoparathyrodism caused by a Cys mutation at the 25th residue of hPTH(1-84) may have arisen from both direct and indirect effects exerted by the mutant PTH itself on bone.
Brain Korea 21 PLUS Project for Medical Science (C.H.B., B.M.P., D.Z., S.-K.L.), Yonsei University, Seoul 03722, Korea; College of Medical Science (M.K., H.J.N.), Yonsei University, Seoul 03722, Korea; Department of Biochemistry and Cell Biology (C.Y.P., J.-Y.C.), BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41566, Korea; Department of Oral Biology (Y.-M.Y., D.M.S.), Brain Korea 21 PLUS Project, College of Dentistry, Yonsei University, Seoul 03722, Korea; and Department of Internal Medicine (S.-K.L.), College of Medicine, Yonsei University, Seoul 03722, Korea.
Chu Hyun
CH
Bae
Brain Korea 21 PLUS Project for Medical Science (C.H.B., B.M.P., D.Z., S.-K.L.), Yonsei University, Seoul 03722, Korea; College of Medical Science (M.K., H.J.N.), Yonsei University, Seoul 03722, Korea; Department of Biochemistry and Cell Biology (C.Y.P., J.-Y.C.), BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41566, Korea; Department of Oral Biology (Y.-M.Y., D.M.S.), Brain Korea 21 PLUS Project, College of Dentistry, Yonsei University, Seoul 03722, Korea; and Department of Internal Medicine (S.-K.L.), College of Medicine, Yonsei University, Seoul 03722, Korea.
Myeongmo
M
Kang
Brain Korea 21 PLUS Project for Medical Science (C.H.B., B.M.P., D.Z., S.-K.L.), Yonsei University, Seoul 03722, Korea; College of Medical Science (M.K., H.J.N.), Yonsei University, Seoul 03722, Korea; Department of Biochemistry and Cell Biology (C.Y.P., J.-Y.C.), BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41566, Korea; Department of Oral Biology (Y.-M.Y., D.M.S.), Brain Korea 21 PLUS Project, College of Dentistry, Yonsei University, Seoul 03722, Korea; and Department of Internal Medicine (S.-K.L.), College of Medicine, Yonsei University, Seoul 03722, Korea.
Clara Yongjoo
CY
Park
Brain Korea 21 PLUS Project for Medical Science (C.H.B., B.M.P., D.Z., S.-K.L.), Yonsei University, Seoul 03722, Korea; College of Medical Science (M.K., H.J.N.), Yonsei University, Seoul 03722, Korea; Department of Biochemistry and Cell Biology (C.Y.P., J.-Y.C.), BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41566, Korea; Department of Oral Biology (Y.-M.Y., D.M.S.), Brain Korea 21 PLUS Project, College of Dentistry, Yonsei University, Seoul 03722, Korea; and Department of Internal Medicine (S.-K.L.), College of Medicine, Yonsei University, Seoul 03722, Korea.
Bo Mi
BM
Park
Brain Korea 21 PLUS Project for Medical Science (C.H.B., B.M.P., D.Z., S.-K.L.), Yonsei University, Seoul 03722, Korea; College of Medical Science (M.K., H.J.N.), Yonsei University, Seoul 03722, Korea; Department of Biochemistry and Cell Biology (C.Y.P., J.-Y.C.), BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41566, Korea; Department of Oral Biology (Y.-M.Y., D.M.S.), Brain Korea 21 PLUS Project, College of Dentistry, Yonsei University, Seoul 03722, Korea; and Department of Internal Medicine (S.-K.L.), College of Medicine, Yonsei University, Seoul 03722, Korea.
Dongdong
D
Zhang
Brain Korea 21 PLUS Project for Medical Science (C.H.B., B.M.P., D.Z., S.-K.L.), Yonsei University, Seoul 03722, Korea; College of Medical Science (M.K., H.J.N.), Yonsei University, Seoul 03722, Korea; Department of Biochemistry and Cell Biology (C.Y.P., J.-Y.C.), BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41566, Korea; Department of Oral Biology (Y.-M.Y., D.M.S.), Brain Korea 21 PLUS Project, College of Dentistry, Yonsei University, Seoul 03722, Korea; and Department of Internal Medicine (S.-K.L.), College of Medicine, Yonsei University, Seoul 03722, Korea.
Hee Jin
HJ
Nam
Brain Korea 21 PLUS Project for Medical Science (C.H.B., B.M.P., D.Z., S.-K.L.), Yonsei University, Seoul 03722, Korea; College of Medical Science (M.K., H.J.N.), Yonsei University, Seoul 03722, Korea; Department of Biochemistry and Cell Biology (C.Y.P., J.-Y.C.), BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41566, Korea; Department of Oral Biology (Y.-M.Y., D.M.S.), Brain Korea 21 PLUS Project, College of Dentistry, Yonsei University, Seoul 03722, Korea; and Department of Internal Medicine (S.-K.L.), College of Medicine, Yonsei University, Seoul 03722, Korea.
Yu-Mi
YM
Yang
Brain Korea 21 PLUS Project for Medical Science (C.H.B., B.M.P., D.Z., S.-K.L.), Yonsei University, Seoul 03722, Korea; College of Medical Science (M.K., H.J.N.), Yonsei University, Seoul 03722, Korea; Department of Biochemistry and Cell Biology (C.Y.P., J.-Y.C.), BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41566, Korea; Department of Oral Biology (Y.-M.Y., D.M.S.), Brain Korea 21 PLUS Project, College of Dentistry, Yonsei University, Seoul 03722, Korea; and Department of Internal Medicine (S.-K.L.), College of Medicine, Yonsei University, Seoul 03722, Korea.
Dong Min
DM
Shin
Brain Korea 21 PLUS Project for Medical Science (C.H.B., B.M.P., D.Z., S.-K.L.), Yonsei University, Seoul 03722, Korea; College of Medical Science (M.K., H.J.N.), Yonsei University, Seoul 03722, Korea; Department of Biochemistry and Cell Biology (C.Y.P., J.-Y.C.), BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41566, Korea; Department of Oral Biology (Y.-M.Y., D.M.S.), Brain Korea 21 PLUS Project, College of Dentistry, Yonsei University, Seoul 03722, Korea; and Department of Internal Medicine (S.-K.L.), College of Medicine, Yonsei University, Seoul 03722, Korea.
Je-Yong
JY
Choi
Brain Korea 21 PLUS Project for Medical Science (C.H.B., B.M.P., D.Z., S.-K.L.), Yonsei University, Seoul 03722, Korea; College of Medical Science (M.K., H.J.N.), Yonsei University, Seoul 03722, Korea; Department of Biochemistry and Cell Biology (C.Y.P., J.-Y.C.), BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 41566, Korea; Department of Oral Biology (Y.-M.Y., D.M.S.), Brain Korea 21 PLUS Project, College of Dentistry, Yonsei University, Seoul 03722, Korea; and Department of Internal Medicine (S.-K.L.), College of Medicine, Yonsei University, Seoul 03722, Korea.
Sung-Kil
SK
Lim
D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D018929:Cell Culture Techniques; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D010052:Ovariectomy; D010281:Parathyroid Hormone / Q000032:analysis / Q000235:genetics / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects*
C470125:PTH protein, human; D010281:Parathyroid Hormone