Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.755461
Title: Hormone responsive genes involved in osteoporosis in post-menopausal women
Author: Dera, A. A.
ISNI:       0000 0004 7428 4552
Awarding Body: University of Liverpool
Current Institution: University of Liverpool
Date of Award: 2017
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Abstract:
The health of our bones is maintained by two major cell types in a delicate balance of active bone remodelling through bone resorption by osteoclasts and bone formation by osteoblasts. An imbalance in the processes leads to osteoporosis, which is a metabolic disorder of the bones that shows increased incidence in postmenopausal women, where estrogen deficiency plays a significant role in its development. Hormone and hormone responsive molecules have emerged as playing a critical role in immunity, metabolism and cell differentiation and their activation is associated with many human diseases. The aim of this project is to investigate hormone and hormone responsive molecules associated with the development of osteoporosis in post-menopausal women. Firstly, a hormone-responsive cell model system was established using osteosarcoma [osteoblast-like] cell lines, Mg-63, TE85 and Saos-2, which represent three different stages of bone maturation. Secondly, the effect of steroid hormones on these cultured cells was analysed using RNA sequencing to identify differentially-expressed hormone responsive genes. Thirdly, the identified genes were further analysed in peripheral blood mononuclear cells (PBMCs), an osteoclast precursor, from osteoporosis patients, female >40 years, to assess potential diagnostic values for osteoporosis. Furthermore, some functions of selected genes and their protein products were investigated using cultured cells. A panel of differentially expressed hormone responsive genes was identified using RNA sequencing from established osteosarcoma cell line, Mg-63 after ßestradiol treatment. 154 genes were up-regulated and 108 genes were downregulated compared to non-treated controls. Further analysis showed that 5 differentially expressed genes were associated with the development of osteoporosis in clinical samples using RT-qPCR. The levels of annexin A1 (ANXA1), calcium binding protein (S100A4), and X-box binding protein transcription factor (XBP1) mRNAs were significantly decreased in PBMCs associated with reduced T-score in osteoporosis patients compared to osteopenia and non-osteoporotic participants (p = 0.0291, p=0.00034, p=0.0001, respectively). Increasing levels of Cathepsin Z (CTSZ), translocation associated membrane protein 2 (TRAM2), and Gasdermin D (GSDMD) mRNAs in PBMCs significantly correlated with reduced T-score in osteoporosis patients compared to osteopenia and non-osteoporotic participants (p = 0.0011, p=0.0161, p=0.0019 respectively). The levels of microRNAs miR-100-5p and miR-99a-5p were significantly decreased in PBMCs associated with the reduced T-score in osteoporosis patients compared to osteopenia and non-osteoporotic controls (p = 0.0002 and p= 0.0270 respectively). However, the levels of miR-196b-3p, miR-1260 and miR-1290 were significantly increased in PBMCs associated with the reduced Tscore in osteoporosis patients compared to osteopenia and non-osteoporotic controls (p = <0.0001, p=0.0072 and p=0.0004 respectively). Furthermore, through a follow-up cellular functional study, suppression of Cathepsin Z (CTSZ) mRNA/protein expression using RNAi significantly inhibited proliferation, migration and invasion of Mg-63 and TE-85 cells. This is the first report of the presence of cathepsin Z mRNA/protein in osteosarcoma cells and the first demonstration of an association between CTSZ and osteoporosis in PBMCs. The results suggest that CTSZ might be a valuable diagnostic and therapeutic target for osteoporosis in postmenopausal women in the future.
Supervisor: Barraclough, Roger ; Ranganath, Lakshminarayan ; Barraclough, Dong Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.755461  DOI:
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