Causal association between cathepsins and bone mineral density: two-way Mendelian randomization analyses

doi:10.12307/2025.391

Abstract

Abstract: BACKGROUND: Previous studies have indicated that cathepsin K can intervene with the occurrence and development of osteoporosis by regulating bone mineral density in middle-aged and older adults. However, whether there is a causal relationship between the cathepsin family and bone mineral density in other populations remains unknown.
OBJECTIVE: To investigate the causal relationship between cathepsin and bone mineral density.
METHODS: Genetic loci associated with eight cathepins were extracted from the IEU Open GWAS database as instrumental variables, and bone mineral density values in five age groups acted as an outcome. The causal relationship between cathepin and bone mineral density was assessed by two-way Mendelian randomization analysis. Heterogeneity of the genetic instrumental variables was assessed using Cochran’s Q test, pleiotropy was assessed using the MR-Egger intercept test, and the sensitivity of single nucleotide polymorphisms used as instrumental variables to the causal effect of exposure and outcome was assessed using the leave-one-out method.
RESULTS AND CONCLUSION: The results of the inverse variance weighting method with positive Mendelian randomization showed that cathepin H was negatively associated with bone mineral density in people aged 45-60 years [odds ratio (95% confidence interval)=0.965(0.94-0.99), P=0.04]; cathepin Z was negatively associated with bone mineral density in people aged 30-45 year [odds ratio (95% confidence interval)=1.06 (1.00-1.11), P=0.03]. The results of sensitivity analysis showed a stable causal relationship, and MR-Egger intercept analysis did not detect potential horizontal pleiotropy. The inverse Mendelian randomization results showed that bone mineral density had no significant inverse effect on cathepin. The above results confirm that cathepin can affect bone mineral density in some age groups, which may increase the risk of osteoporosis and should be given more attention.

中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程

Key words: bone mineral density, cathepsin, Mendelian randomization, causal association, different age groups

CLC Number:

Jiang Nan, Fu Haonan, Hao Yuhan, Chen Zhilin, Zhu Zhiqing, Xu Feng, Yu Dong. Causal association between cathepsins and bone mineral density: two-way Mendelian randomization analyses[J]. Chinese Journal of Tissue Engineering Research, 2025, 29(12): 2623-2630.

Figures/Tables 6

2.1 正向孟德尔随机化结果 2.1.1 组织蛋白酶H与 > 45岁且≤60岁人群骨密度的因果关系逆方差加权法分析结果显示，OR(95% CI)=0.97(0.94-1.00)，P=0.04；MR-Egger分析结果显示，OR(95% CI)=0.99(0.95-1.03)，P=0.59]；加权中值法分析结果显示，OR(95% CI)=0.99(0.95-1.03)，P=0.11。3种分析方法因果效应方向一致(OR值均< 1)，散点图显示回归线无明显偏移(图2A)，故提示组织蛋白酶H与> 45岁且≤60岁人群骨密度有反向因果关系，组织蛋白酶H是> 45岁且≤60岁人群骨密度的保护因素。具体数据细节见表2。 2.1.2 组织蛋白酶Z与 > 30岁且≤45岁人群骨密度的因果关系逆方差加权法分析结果显示，OR(95% CI)=1.06(1.00-1.11)，P=0.03；MR-Egger分析结果显示，OR(95% CI)=1.07(0.99-1.16)，P=0.45；加权中值法分析结果显示，OR(95% CI)=1.06(0.99-1.13)， P=0.25。3种分析方法因果效应方向一致(OR值均 > 1)，散点图显示回归线无明显偏移(图2B)，故提示组织蛋白Z与 > 30岁且≤45岁人群骨密度有正向因果关系，组织蛋白酶Z是 > 30岁且≤45岁人群骨密度的危险因素。具体数据细节见表2。 2.2 正向孟德尔随机化结果敏感性分析研究结果的MR-Egger回归截距均接近于0，未检测到潜在的水平多效性，P均 > 0.05(组织蛋白酶H：P=0.219；组织蛋白酶Z：P=0.617)，即说明所选工具变量并不通过暴露以外的途径影响结局，符合排他性假设。Cochran’s Q检验结果表明，组织蛋白酶与不同年龄阶段骨密度结果存在潜在的异质性。MR-PRESSO多效性测试显示无离群单核苷酸多态性，见表3。选取的工具变量与不同年龄段骨密度的因果关系不会受到水平多效性的影响，结果较可靠。留一法结果表明消除任何一个单核苷酸多态性都不会显著影响因果相关的估计，提示孟德尔随机化分析结果稳健，见图3。漏斗图中呈现的因果效应分布具有基本对称性，未见明显偏倚，见图4。 2.3 反向孟德尔随机化分析结果反向孟德尔随机化分析结果表明，8种组织蛋白酶不同年龄段人群骨密度之间均不存在显著的反向因果关系(图5)，即各年龄段人群骨密度均不会对人体内8种组织蛋白酶产生影响。"

References

[1] BUCK DW 2ND, DUMANIAN GA. Bone biology and physiology: Part I. The fundamentals. Plast Reconstr Surg. 2012; 129(6):1314-1320.
[2] CHILIBECK PD, SALE DG, WEBBER CE. Exercise and bone mineral density. Sports Med. 1995;19(2):103-122.
[3] CHEN M, GERGES M, RAYNOR WY, et al. State of the Art Imaging of Osteoporosis. Semin Nucl Med. 2024;54(3):415-426.
[4] LIU K, LIU P, LIU R, et al. Relationship between serum leptin levels and bone mineral density: a systematic review and meta-analysis. Clin Chim Acta. 2015;444: 260-263.
[5] LEE S, KIM JH, JEON YK, et al. Effect of adipokine and ghrelin levels on BMD and fracture risk: an updated systematic review and meta-analysis. Front Endocrinol (Lausanne). 2023;14:1044039.
[6] HARTLEY A, SANDERSON E, GRANELL R, et al. Using multivariable Mendelian randomization to estimate the causal effect of bone mineral density on osteoarthritis risk, independently of body mass index. Int J Epidemiol. 2022;51(4):1254-1267.
[7] GIELEN E, DUPONT J, DEJAEGER M, et al. Sarcopenia, osteoporosis and frailty. Metabolism. 2023;145:155638.
[8] LASKOU F, FUGGLE NR, PATEL HP, et al. Associations of osteoporosis and sarcopenia with frailty and multimorbidity among participants of the Hertfordshire Cohort Study. J Cachexia Sarcopenia Muscle. 2022; 13(1):220-229.
[9] 李明嘉,赵苗妙,杨金奎.组织蛋白酶在糖尿病及糖尿病肾病作用机制中的研究进展[J].首都医科大学学报,2023,44(3): 413-419.
[10] YADATI T, HOUBEN T, BITORINA A, et al. The Ins and Outs of Cathepsins: Physiological Function and Role in Disease Management. Cells. 2020;9(7):1679.
[11] 董飞,王玲.绝经后女性骨转换生化标志物水平与骨密度的相关性分析[J].检验医学与临床,2021,18(9):1323-1325.
[12] LEE GH, HOANG TH, LEE HY, et al. Ramie leaf Extract Alleviates Bone Loss in Ovariectomized Rats-The Involvement of ROS and Its Associated Signalings. Nutrients. 2023;15(3):745.
[13] LU J, WANG M, WANG Z, et al. Advances in the discovery of cathepsin K inhibitors on bone resorption. J Enzyme Inhib Med Chem. 2018;33(1):890-904.
[14] GAO LH, LI SS, YUE H, et al. Associations of Serum Cathepsin K and Polymorphisms in CTSK Gene With Bone Mineral Density and Bone Metabolism Markers in Postmenopausal Chinese Women. Front Endocrinol (Lausanne). 2020;11:48.
[15] CLAYTON GL, GONÇALVES A, SOARES, et al. A framework for assessing selection and misclassification bias in mendelian randomisation studies: an illustrative example between body mass index and covid-19. BMJ. 2023;381:e072148.
[16] NAZARZADEH M, PINHO-GOMES AC, BIDEL Z, et al. Plasma lipids and risk of aortic valve stenosis: a Mendelian randomization study. Eur Heart J. 2020;41(40):3913-3920.
[17] BURGESS S, SCOTT RA, TIMPSON NJ, et al. EPIC- InterAct Consortium. Using published data in Mendelian randomization: a blueprint for efficient identification of causal risk factors. Eur J Epidemiol. 2015; 30(7):543-552.
[18] BURGESS S, DAVEY SMITH G, DAVIES NM, et al. Guidelines for performing Mendelian randomization investigations: update for summer 2023. Wellcome Open Res. 2023;4:186.
[19] SKRIVANKOVA VW, RICHMOND RC, WOOLF BAR, et al. Strengthening the Reporting of Observational Studies in Epidemiology Using Mendelian Randomization: The STROBE-MR Statement. JAMA. 2021;326(16):1614-1621.
[20] BURGESS S, THOMPSON SG. Bias in causal estimates from Mendelian randomization studies with weak instruments. Stat Med. 2011;30(11):1312-1323.
[21] 黄国鑫,陈霞丽,裴斌.孟德尔随机化探索骨密度与膝关节骨性关节炎的因果关联[J].中国骨质疏松杂志,2023,29(4): 512-517.
[22] CODD V, NELSON CP, ALBRECHT E, et al. Identification of seven loci affecting mean telomere length and their association with disease. Nat Genet. 2013;45(4):422-427.
[23] LI W, LU Q, QIAN J, et al. Assessing the causal relationship between genetically determined inflammatory biomarkers and low back pain risk: a bidirectional two-sample Mendelian randomization study. Front Immunol. 2023;14:1174656.
[24] LEVIN MG, JUDY R, GILL D, et al. Genetics of height and risk of atrial fibrillation: A Mendelian randomization study. PLoS Med. 2020;17(10):e1003288.
[25] CODD V, NELSON CP, ALBRECHT E, et al. Identification of seven loci affecting mean telomere length and their association with disease. Nat Genet. 2013;45(4): 422-427e4272.

[26] ZHAO J, WANG J, XU H, et al. Intervertebral Disk Degeneration and Bone Mineral Density: A Bidirectional Mendelian Randomization Study. Calcif Tissue Int. 2024;114(3):228-236.
[27] YUAN S, MIAO Y, RUAN X, et al. Therapeutic role of interleukin-1 receptor antagonist in pancreatic diseases: mendelian randomization study. Front Immunol. 2023;14:1240754.
[28] HAN Y, ZHANG Y, ZENG X. Assessment of causal associations between uric acid and 25-hydroxyvitamin D levels. Front Endocrinol (Lausanne). 2022;13:1024675.
[29] BURGESS S, DUDBRIDGE F, THOMPSON SG. Combining information on multiple instrumental variables in Mendelian randomization: comparison of allele score and summarized data methods. Stat Med. 2016;35(11):1880-906.
[30] BURGESS S, BUTTERWORTH A, THOMPSON SG. Mendelian randomization analysis with multiple genetic variants using summarized data. Genet Epidemiol. 2013;37(7):658-665.
[31] LI W, LU Q, QIAN J, et al. Assessing the causal relationship between genetically determined inflammatory biomarkers and low back pain risk: a bidirectional two-sample Mendelian randomization study. Front Immunol. 2023;14:1174656.
[32] YUAN S, MIAO Y, RUAN X, et al. Therapeutic role of interleukin-1 receptor antagonist in pancreatic diseases: mendelian randomization study. Front Immunol. 2023;14:1240754.
[33] LU Y, WANG Z, ZHENG L. Association of smoking with coronary artery disease and myocardial infarction: A Mendelian randomization study. Eur J Prev Cardiol. 2021;28(12):e11-e12.
[34] BOWDEN J, DAVEY SMITH G, HAYCOCK PC, et al. Consistent Estimation in Mendelian Randomization with Some Invalid Instruments Using a Weighted Median Estimator. Genet Epidemiol. 2016; 40(4):304-314.
[35] BOWDEN J, DEL GRECO MF, MINELLI C,
et al. Assessing the suitability of summary data for two-sample Mendelian randomization analyses using MR-Egger regression: the role of the I2 statistic. Int J Epidemiol. 2016;45(6):1961-1974.
[36] BOWDEN J, DEL GRECO MF, MINELLI C,
et al. Improving the accuracy of two-sample summary-data Mendelian randomization: moving beyond the NOME assumption. Int J Epidemiol. 2019;48(3):728-742.
[37] MATSUZAKI M, PANT R, KULKARNI B, et al. Comparison of Bone Mineral Density between Urban and Rural Areas: Systematic Review and Meta-Analysis. PLoS One. 2015; 10(7):e0132239.
[38] YUAN J, JIA P, ZHOU JB. Comparison of Bone Mineral Density in US Adults With Diabetes, Prediabetes and Normoglycemia From 2005 to 2018. Front Endocrinol (Lausanne). 2022;13:890053.
[39] PLUSKIEWICZ W, ADAMCZYK P, DROZDZOWSKA B. Glucocorticoids Increase Fracture Risk and Fracture Prevalence Independently from Bone Mineral Density and Clinical Risk Factors: Results from the Gliwice Osteoporosis (GO) Study. Horm Metab Res. 2022;54(1):20-24.
[40] BLAIR HC, KAHN AJ, CROUCH EC, et al. Isolated osteoclasts resorb the organic and inorganic components of bone. J Cell Biol. 1986;102(4):1164-1172.
[41] BILLINGTON EO, MAHAJAN A, BENHAM JL, et al. Effects of probiotics on bone mineral density and bone turnover: A systematic review. Crit Rev Food Sci Nutr. 2023;63(19):4141-4152.
[42] SHOREY S, HEERSCHE JN, MANOLSON MF. The relative contribution of cysteine proteinases and matrix metalloproteinases to the resorption process in osteoclasts derived from long bone and scapula. Bone. 2004;35(4):909-917.
[43] STRÅLBERG F, KASSEM A, KASPRZYKOWSKI F, et al. Inhibition of lipopolysaccharide-induced osteoclast formation and bone resorption in vitro and in vivo by cysteine proteinase inhibitors. J Leukoc Biol. 2017; 101(5):1233-1243.
[44] HOLZER G, NOSKE H, LANG T, et al. Soluble cathepsin K: a novel marker for the prediction of nontraumatic fractures? J Lab Clin Med. 2005;146(1):13-17.
[45] LANG TH, WILLINGER U, HOLZER G. Soluble cathepsin-L: a marker of bone resorption and bone density? J Lab Clin Med. 2004;144(3):163-166.
[46] WILSON TJ, NANNURU KC, SINGH RK. Cathepsin G-mediated activation of pro-matrix metalloproteinase 9 at the tumor-bone interface promotes transforming growth factor-beta signaling and bone destruction. Mol Cancer Res. 2009;7(8): 1224-1233.
[47] JEVNIKAR Z, OBERMAJER N, BOGYO M, et al. The role of cathepsin X in the migration and invasiveness of T lymphocytes. J Cell Sci. 2008;121(Pt 16):2652-2661.
[48] CAI X, GAO C, SONG H, et al. Characterization, expression profiling and functional characterization of cathepsin Z (CTSZ) in turbot (Scophthalmus maximus L.). Fish Shellfish Immunol. 2019;84:599-608.
[49] UDAGAWA N, TAKAHASHI N, AKATSU T, et al. Origin of osteoclasts: mature monocytes and macrophages are capable of differentiating into osteoclasts under a suitable microenvironment prepared by bone marrow-derived stromal cells. Proc Natl Acad Sci U S A. 1990;87(18):7260-7264.
[50] TROEN BR. The role of cathepsin K in normal bone resorption. Drug News Perspect. 2004;17(1):19-28.
[51] STAUDT ND, AICHER WK, KALBACHER H, et al. Cathepsin X is secreted by human osteoblasts, digests CXCL-12 and impairs adhesion of hematopoietic stem and progenitor cells to osteoblasts. Haematologica. 2010;95(9):1452-1460.
[52] LIU M, GOSS PE, INGLE JN, et al. Aromatase inhibitor-associated bone fractures: a case-cohort GWAS and functional genomics. Mol Endocrinol. 2014;28(10):1740-1751.
[53] DERA AA, RANGANATH L, BARRACLOUGH R, et al. Cathepsin Z as a novel potential biomarker for osteoporosis. Sci Rep. 2019; 9(1):9752.