Reproductive age-associated fibrosis in the stroma of the mammalian ovary
Open accessAbstract
Under normal physiological conditions, tissue remodeling in response to injury leads to tissue regeneration without permanent damage. However, if homeostasis between synthesis and degradation of extracellular matrix (ECM) components is altered, fibrosis – or the excess accumulation of ECM – can disrupt tissue architecture and function. Several organs, including the heart, lung and kidney, exhibit age-associated fibrosis. Here we investigated whether fibrosis underlies aging in the ovary – an organ that ages chronologically before other organs. We used Picrosirius Red (PSR), a connective tissue stain specific for collagen I and III fibers, to evaluate ovarian fibrosis. Using bright-field, epifluorescence, confocal and polarized light microscopy, we validated the specific staining of highly ordered PSR-stained fibers in the ovary. We next examined ovarian PSR staining in two mouse strains (CD1 and CB6F1) across an aging continuum and found that PSR staining was minimal in ovaries from reproductively young adult animals, increased in distinct foci in animals of mid-to-advanced reproductive age, and was prominent throughout the stroma of the oldest animals. Consistent with fibrosis, there was a reproductive age-associated increase in ovarian hydroxyproline content. We also observed a unique population of multinucleated macrophage giant cells, which are associated with chronic inflammation, within the ovarian stroma exclusively in reproductively old mice. In fact, several genes central to inflammation had significantly higher levels of expression in ovaries from reproductively old mice relative to young mice. These results establish fibrosis as an early hallmark of the aging ovarian stroma, and this altered microenvironment may contribute to the age-associated decline in gamete quality.
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The ovary exhibits age-dependent inflammation and fibrosis, but whether these are associated with senescence has not been conclusively established.
“Additionally, the ovary exhibits age-dependent inflammation and fibrosis234–237; however, whether these are associated with senescence has not been conclusively established.”
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Cites
NIH Image to ImageJ: 25 years of image analysis
Schneider, C. A., Rasband, W. S., & Eliceiri, K. W. (2012) · Nature Methods · doi:10.1038/nmeth.2089 · Cited by 64,638 · see citing works
The chemokine system in diverse forms of macrophage activation and polarization
MANTOVANI, A., SICA, A., SOZZANI, S., ALLAVENA, P., VECCHI, A., & LOCATI, M. (2004) · Trends in Immunology · doi:10.1016/j.it.2004.09.015 · Cited by 6,534 · see citing works
Protective and pathogenic functions of macrophage subsets
Murray, P. J., & Wynn, T. A. (2011) · Nature Reviews Immunology · doi:10.1038/nri3073 · Cited by 5,269 · see citing works
Mechanisms of fibrosis: therapeutic translation for fibrotic disease
Wynn, T. A., & Ramalingam, T. R. (2012) · Nature Medicine · doi:10.1038/nm.2807 · Cited by 3,541 · see citing works
Junqueira, L. C. U., Bignolas, G., & Brentani, H. (1979) · The Histochemical Journal · doi:10.1007/bf01002772 · Cited by 2,570 · see citing works
Klinge, U., Park, J.-K., & Klosterhalfen, B. (2013) · Pathobiology · doi:10.1159/000348446 · Cited by 1,791 · see citing works
Hepatotoxicity and Mechanism of Action of Haloalkanes: Carbon Tetrachloride as a Toxicological Model
Weber, L. W. D., Boll, M., & Stampfl, A. (2003) · Critical Reviews in Toxicology · doi:10.1080/713611034 · Cited by 1,780 · see citing works
Macrophages: master regulators of inflammation and fibrosis
Wynn, T., & Barron, L. (2010) · Seminars in Liver Disease · doi:10.1055/s-0030-1255354 · Cited by 1,392 · see citing works
A simplified method for the analysis of hydroxyproline in biological tissues
Reddy, G. K., & Enwemeka, C. S. (1996) · Clinical Biochemistry · doi:10.1016/0009-9120(96)00003-6 · Cited by 1,299 · see citing works
Ovarian aging: mechanisms and clinical consequences
Broekmans, F. J., Soules, M. R., & Fauser, B. C. (2009) · Endocrine Reviews · doi:10.1210/er.2009-0006 · Cited by 1,248 · see citing works
Ramachandran, P., Pellicoro, A., Vernon, M. A., Boulter, L., Aucott, R. L., Ali, A., Hartland, S. N., Snowdon, V. K., Cappon, A., Gordon-Walker, T. T., et al. (2012) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1119964109 · Cited by 1,001 · see citing works
Human aneuploidy: mechanisms and new insights into an age-old problem
Nagaoka, S. I., Hassold, T. J., & Hunt, P. A. (2012) · Nature Reviews Genetics · doi:10.1038/nrg3245 · Cited by 994 · see citing works
Spandidos, A., Wang, X., Wang, H., & Seed, B. (2009) · Nucleic Acids Research · doi:10.1093/nar/gkp1005 · Cited by 900 · see citing works
Structural and Functional Changes With the Aging Kidney
Đenić, A., Glassock, R. J., & Rule, A. D. (2015) · Advances in Chronic Kidney Disease · doi:10.1053/j.ackd.2015.08.004 · Cited by 871 · see citing works
A PCR primer bank for quantitative gene expression analysis
Wang, X. (2003) · Nucleic Acids Research · doi:10.1093/nar/gng154 · Cited by 849 · see citing works
Interleukin-6 in Aging and Chronic Disease: A Magnificent Pathway
Maggio, M. G., Guralnik, J. M., Longo, D. L., & Ferrucci, L. (2006) · The Journals of Gerontology Series A · doi:10.1093/gerona/61.6.575 · Cited by 687 · see citing works
Inflammatory Mechanisms: The Molecular Basis of Inflammation and Disease
Libby, P. (2008) · Nutrition Reviews · doi:10.1111/j.1753-4887.2007.tb00352.x · Cited by 612 · see citing works
Differential Staining of Collagens Type I, II and III by Sirius Red and Polarization Microscopy
Junqueira, L. C. U., Cossermelli, W., & Brentani, H. (1978) · Archivum histologicum japonicum · doi:10.1679/aohc1950.41.267 · Cited by 590 · see citing works
Advanced Maternal Age — How Old Is Too Old?
Heffner, L. J. (2004) · New England Journal of Medicine · doi:10.1056/nejmp048087 · Cited by 559 · see citing works
Ushiki, T. (2002) · Archivum histologicum japonicum · doi:10.1679/aohc.65.109 · Cited by 521 · see citing works
Lattouf, R., Younes, R., Lutomski, D., Naaman, N., Godeau, G., Senni, K., & Changotade, S. (2014) · Journal of Histochemistry & Cytochemistry · doi:10.1369/0022155414545787 · Cited by 519 · see citing works
Whittaker, P., Kloner, R. A., Boughner, D. R., & Pickering, J. G. (1994) · Basic Research in Cardiology · doi:10.1007/bf00788278 · Cited by 496 · see citing works
Hinz, B. (2016) · Experimental Eye Research · doi:10.1016/j.exer.2015.07.009 · Cited by 424 · see citing works
Evidence that Weakened Centromere Cohesion Is a Leading Cause of Age-Related Aneuploidy in Oocytes
Chiang, T., Duncan, F. E., Schindler, K., Schultz, R. M., & Lampson, M. A. (2010) · Current Biology · doi:10.1016/j.cub.2010.06.069 · Cited by 409 · see citing works
Self-citationMacrophage contributions to ovarian function
Wu, R. (2004) · Human Reproduction Update · doi:10.1093/humupd/dmh011 · Cited by 387 · see citing works
Wick, G., Grundtman, C., Mayerl, C., Wimpissinger, F., Feichtinger, J., Zelger, B. G., Sgonc, R., & Wolfram, D. (2013) · Annual Review of Immunology · doi:10.1146/annurev-immunol-032712-095937 · Cited by 336 · see citing works
The use of the Picrosirius-polarization method for the study of the biopathology of collagen
Montes, G. S., & Junqueira, L. C. U. (1991) · Memórias do Instituto Oswaldo Cruz · doi:10.1590/s0074-02761991000700002 · Cited by 332 · see citing works
Molecular mediators of macrophage fusion
Helming, L., & Gordon, S. (2009) · Trends in Cell Biology · doi:10.1016/j.tcb.2009.07.005 · Cited by 326 · see citing works
Induced Hypothermia Does Not Harm Hemodynamics after Polytrauma: A Porcine Model
Weuster, M., Mommsen, P., Pfeifer, R., Mohr, J., Ruchholtz, S., Flohé, S., Fröhlich, M., Keibl, C., Seekamp, A., van Griensven, M., et al. (2015) · Mediators of Inflammation · doi:10.1155/2015/829195 · Cited by 313 · see citing works
Trends in the management and burden of alcoholic liver disease
Mathurin, P., & Bataller, R. (2015) · Journal of Hepatology · doi:10.1016/j.jhep.2015.03.006 · Cited by 288 · see citing works
Aging and the cardiac collagen matrix: Novel mediators of fibrotic remodelling
Horn, M., & Trafford, A. W. (2015) · Journal of Molecular and Cellular Cardiology · doi:10.1016/j.yjmcc.2015.11.005 · Cited by 273 · see citing works
Spandidos, A., Wang, X., Wang, H., Dragnev, S., Thurber, T. K., & Seed, B. (2008) · BMC Genomics · doi:10.1186/1471-2164-9-633 · Cited by 270 · see citing works
Fibrosis Related Inflammatory Mediators: Role of the IL‐10 Cytokine Family
Sziksz, E., Pap, D., Lippai, R., Beres, N. J., Fekete, A., Szabo, A. J., & Vannay, Á. (2015) · Mediators of Inflammation · doi:10.1155/2015/764641 · Cited by 268 · see citing works
Modeling Liver Fibrosis in Rodents
Constandinou, C. M., Henderson, N. C., & Iredale, J. P. (2005) · Humana Press eBooks · doi:10.1385/1-59259-940-0:237 · Cited by 247 · see citing works
An Age-Related Ovarian Phenotype in Mice with Targeted Disruption of the Cyp 19 (Aromatase) Gene
Britt, K. L., Drummond, A. E., Cox, V. A., Dyson, M., Wreford, N. G., Jones, M. E. E., Simpson, E. R., & Findlay, J. K. (2000) · Endocrinology · doi:10.1210/endo.141.7.7578 · Cited by 234 · see citing works
Johnson, J.-A., Tough, S., Wilson, R. D., Audibert, F., Blight, C., BrockS, J.-A., Cartier, L., Désilets, V. A., Gagnon, A. L., Langlois, S. F., et al. (2012) · Journal of Obstetrics and Gynaecology Canada · doi:10.1016/s1701-2163(16)35138-6 · Cited by 228 · see citing works
Cyclic Changes in the Matrix Metalloproteinase System in the Ovary and Uterus1
Curry, T. E., & Osteen, K. G. (2001) · Biology of Reproduction · doi:10.1095/biolreprod64.5.1285 · Cited by 224 · see citing works
Molecular causes of aneuploidy in mammalian eggs
Jones, K. T., & Lane, S. I. R. (2013) · Development · doi:10.1242/dev.090589 · Cited by 196 · see citing works
Macrophage Fusion and Multinucleated Giant Cells of Inflammation
McNally, A. K., & Anderson, J. M. (2011) · Advances in experimental medicine and biology · doi:10.1007/978-94-007-0763-4_7 · Cited by 189 · see citing works
Pigments in Aging: An Overview
Porta, E. A. (2002) · Annals of the New York Academy of Sciences · doi:10.1111/j.1749-6632.2002.tb02083.x · Cited by 173 · see citing works
Conventional and confocal fluorescence microscopy of collagen fibers in the heart.
Dolber, P. C., & Spach, M. S. (1993) · Journal of Histochemistry & Cytochemistry · doi:10.1177/41.3.7679127 · Cited by 171 · see citing works
Berkholtz, C. B., Lai, B. E., Woodruff, T. K., & Shea, L. D. (2006) · Histochemistry and Cell Biology · doi:10.1007/s00418-006-0194-1 · Cited by 169 · see citing works
Vogel, B., Siebert, H., Hofmann, U., et al. (2015) · MethodsX · doi:10.1016/j.mex.2015.02.007 · Cited by 152 · see citing works
Interleukin-1 deficiency prolongs ovarian lifespan in mice
Uri-Belapolsky, S., Shaish, A., Eliyahu, E., Grossman, H., Levi, M., Chuderland, D., Ninio-Many, L., Hasky, N., Shashar, D., Almog, T., et al. (2014) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1323955111 · Cited by 136 · see citing works
Denys, A., Udalova, I. A., Smith, C., Williams, L. M., Ciesielski, C. J., Campbell, J., Andrews, C., Kwiatkowski, D. P., & Foxwell, B. M. J. (2002) · The Journal of Immunology · doi:10.4049/jimmunol.168.10.4837 · Cited by 127 · see citing works
Tingen, C. M., Kiesewetter, S. E., Jozefik, J. K., Thomas, C., Tagler, D., Shea, L. D., & Woodruff, T. K. (2011) · Reproduction · doi:10.1530/rep-10-0483 · Cited by 125 · see citing works
Polarized light imaging of birefringence and diattenuation at high resolution and high sensitivity
Mehta, S. B., Shribak, M., & Oldenbourg, R. (2013) · Journal of Optics · doi:10.1088/2040-8978/15/9/094007 · Cited by 114 · see citing works
Polarized light imaging of birefringence and diattenuation at high resolution and high sensitivityPreprint
Mehta, S. B., Shribak, M. I., & Oldenbourg, R. (2013) · Open Access Server of the Woods Hole Scientific Community (Woods Hole Scientific Community) · Cited by 114 · see citing works
Effects of cancer treatment on ovarian function
Stroud, J., Mutch, D. G., Rader, J. S., et al. (2008) · Fertility and Sterility · doi:10.1016/j.fertnstert.2008.07.1714 · Cited by 108 · see citing works
Merriman, J. A., Jennings, P. C., McLaughlin, E. A., et al. (2011) · Biology of Reproduction · doi:10.1095/biolreprod.111.095711 · Cited by 106 · see citing works
Sahin, H., & Wasmuth, H. E. (2012) · Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease · doi:10.1016/j.bbadis.2012.11.004 · Cited by 104 · see citing works
Interleukin-6: a new therapeutic target in systemic sclerosis?
O'Reilly, S., Cant, R., Ciechomska, M., & van Laar, J. V. (2013) · Clinical & Translational Immunology · doi:10.1038/cti.2013.2 · Cited by 104 · see citing works
Myles, T. D., Peracchio, A. A., & Chiu, W. K. S. (2015) · Journal of Applied Physics · doi:10.1063/1.4905119 · Cited by 103 · see citing works
Automated quantification of renal fibrosis with Sirius Red and polarization contrast microscopy
Street, J. M., Souza, A. C. P., Álvarez-Prats, A., Horino, T., Hu, X., Yuen, P. S. T., & Star, R. A. (2014) · Physiological Reports · doi:10.14814/phy2.12088 · Cited by 101 · see citing works
The chronic enteropathogenic disease schistosomiasis
Olveda, D. U., Olveda, R. M., McManus, D. P., et al. (2014) · International Journal of Infectious Diseases · doi:10.1016/j.ijid.2014.07.009 · Cited by 99 · see citing works
Influence of age on wound healing and fibrosis
Kapetanaki, M. G., Mora, A. L., & Rojas, M. M. (2012) · The Journal of Pathology · doi:10.1002/path.4122 · Cited by 90 · see citing works
Wood, C. D., Vijayvergia, M., Miller, F. H., et al. (2014) · Acta Biomaterialia · doi:10.1016/j.actbio.2014.11.022 · Cited by 74 · see citing works
Fibrosis in alcoholic and nonalcoholic steatohepatitis
Bataller, R. A., Rombouts, K., Altamirano, J., & Marra, F. (2011) · Best Practice & Research Clinical Gastroenterology · doi:10.1016/j.bpg.2011.02.010 · Cited by 74 · see citing works
Dynamics of extracellular matrix in ovarian follicles and corpora lutea of mice
Irving‐Rodgers, H. F., Hummitzsch, K., Murdiyarso, L. S., Bonner, W. M., Sado, Y., Ninomiya, Y., Couchman, J., Sorokin, L. M., & Rodgers, R. J. (2009) · Cell and Tissue Research · doi:10.1007/s00441-009-0905-8 · Cited by 71 · see citing works
Ramm, G. A., & Ruddell, R. G. (2010) · Seminars in Liver Disease · doi:10.1055/s-0030-1255356 · Cited by 69 · see citing works
Picrosirius red staining revisited
Coleman, R. (2010) · Acta Histochemica · doi:10.1016/j.acthis.2010.02.002 · Cited by 68 · see citing works
Role of TLR4 in ethanol effects on innate and adaptive immune responses in peritoneal macrophages
Pascual, M., Fernández‐Lizarbe, S., & Guerri, C. (2011) · Immunology and Cell Biology · doi:10.1038/icb.2010.163 · Cited by 60 · see citing works
Asano, Y. (2011) · Journal of Histochemistry & Cytochemistry · doi:10.1369/0022155411431734 · Cited by 57 · see citing works
Pritchard, M. T., Cohen, J. I., Roychowdhury, S., Pratt, B. T., & Nagy, L. E. (2010) · Journal of Hepatology · doi:10.1016/j.jhep.2010.04.017 · Cited by 52 · see citing works
Self-citationPritchard, M. T., & Nagy, L. E. (2010) · American Journal Of Pathology · doi:10.2353/ajpath.2010.091186 · Cited by 48 · see citing works
Self-citationAnimal age, weight and estrus cycle stage impact the quality of in vitro grown follicles
Hirshfeld‐Cytron, J., Duncan, F. E., Xu, M., Jozefik, J. K., Shea, L. D., & Woodruff, T. K. (2011) · Human Reproduction · doi:10.1093/humrep/der183 · Cited by 44 · see citing works
Self-citationCardiorenal fibrosis and dysfunction in aging: Imbalance in mediators and regulators of collagen
Sangaralingham, S. J., Wang, B. H., Huang, L., Kumfu, S., Ichiki, T., Krum, H., & Burnett, J. C. J. (2016) · Peptides · doi:10.1016/j.peptides.2016.01.004 · Cited by 43 · see citing works
Sirius Red and Acid Fuchsin Staining Mechanisms
Nielsen, L. F., Moe, D., Kirkeby, S., et al. (1998) · Biotechnic & Histochemistry · doi:10.3109/10520299809140509 · Cited by 41 · see citing works
Treff, N. R., Krisher, R. L., Tao, X., et al. (2016) · Biology of Reproduction · doi:10.1095/biolreprod.115.135483 · Cited by 41 · see citing works
Robin, J. (2005) · Humana Press eBooks · doi:10.1385/1-59259-940-0:189 · Cited by 37 · see citing works
Age-associated alterations in the micromechanical properties of chromosomes in the mammalian egg
Hornick, J. E., Duncan, F. E., Sun, M., et al. (2015) · Journal of Assisted Reproduction and Genetics · doi:10.1007/s10815-015-0453-y · Cited by 27 · see citing works
Self-citationBulut, G., Kurdoğlu, Z., Donmez, Y. B., Kurdoğlu, M., & Erten, R. (2015) · PubMed Central · Cited by 21 · see citing works
CHECK, J. H., Jamison, T., CHECK, D. L., et al. (2011) · PubMed · Cited by 21 · see citing works
Alves, A., Gritsch, K., Sirieix, C., et al. (2015) · Microscopy Research and Technique · doi:10.1002/jemt.22553 · Cited by 8 · see citing works
[Result of histochemical studies on certain PAS-positive substances in macrophages].
Sobolev, S. M. (1959) · PubMed · Cited by 2 · see citing works
[Motor chronaxy in malignant and benign tumors and in therapy of general conditions].
TIMOSHECHKINA, M. E. (1959) · PubMed · Cited by 1 · see citing works
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Cited by
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SenNet recommendations for detecting senescent cells in different tissues
Suryadevara, V., Hudgins, A. D., Rajesh, A., Pappalardo, A., Karpova, A., Dey, A. K., Hertzel, A., Agudelo, A., Rocha, A., Soygur, B., et al. (2024) · Nature Reviews Molecular Cell Biology · doi:10.1038/s41580-024-00738-8 · Cited by 408 · see citing works
“Additionally, the ovary exhibits age-dependent inflammation and fibrosis 234–237 ; however, whether these are associated with senescence has not been conclusively established.”
Self-citationAmargant, F., Manuel, S. L., Tu, Q., Parkes, W. S., Rivas, F., Zhou, L. T., Rowley, J. E., Villanueva, C. E., Hornick, J. E., Shekhawat, G. S., et al. (2020) · Aging Cell · doi:10.1111/acel.13259 · Cited by 280 · see citing works
Self-citationEvaluation of inflammation and follicle depletion during ovarian ageing in mice
Lliberos, C., Liew, S. H., Zareie, P., La Gruta, N. L., Mansell, A., & Hutt, K. (2021) · Scientific Reports · doi:10.1038/s41598-020-79488-4 · Cited by 247 · see citing works
Zhang, Z., Schlamp, F., Huang, L., Clark, H., & Brayboy, L. (2020) · Reproduction · doi:10.1530/rep-19-0330 · Cited by 150 · see citing works
Cellular hallmarks of aging emerge in the ovary prior to primordial follicle depletion
Ansere, V. A., Ali-Mondal, S., Sathiaseelan, R., Garcia, D. N., Isola, J. V. V., Henseb, J. D., Saccon, T. D., Ocañas, S. R., Tooley, K. B., Stout, M. B., et al. (2021) · Mechanisms of Ageing and Development · doi:10.1016/j.mad.2020.111425 · Cited by 101 · see citing works
- Authors
- Briley, S. M., Jasti, S., McCracken, J. M., Hornick, J. E., Fegley, B., Pritchard, M. T., & Duncan, F. E.
- Affiliations
- University of Kansas Medical Center (US)
- Northwestern University (US)
- Corresponding author
- Duncan, Francesca E
- Venue
- Reproduction
- Publisher
- Oxford University Press (OUP)
- Published
- 2016-09-01
- Volume
- 152
- Issue
- 3
- Pages
- 245-260
- ISSN
- 1470-1626 (ISSN-L)
- 1741-7899
- PMC
- PMC4979755
- OpenAlex
- W2497766038
- Cited by
- 373
- References
- 76
- Citations by year
- 2026: 53 · 2025: 64 · 2024: 77 · 2023: 50 · 2022: 39 · 2021: 25 · 2020: 26 · 2019: 15 · 2018: 13 · 2017: 10 · 2016: 1
- FWCI
- 12.89
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Reproduction (publishedVersion)
- PubMed (publishedVersion)
- Europe PMC (PubMed Central) (acceptedVersion)
- PubMed Central (acceptedVersion)
- Funders
- National Institute of General Medical Sciences (P20GM103549, P20GM104936, P20GM103418)
- National Institute of Environmental Health Sciences (T32ES007079)
- National Center for Research Resources (P20RR021940, S10RR027564)
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (P30HD002528, P50HD076188)
- Topics
- Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Reproductive Biology and Fertility
- Health Sciences › Medicine › Reproductive Medicine › Ovarian function and disorders
- Health Sciences › Medicine › Reproductive Medicine › Ovarian cancer diagnosis and treatment
- Keywords
- ovarian aging, ovarian fibrosis, ovarian stroma, extracellular matrix, collagen I and III, picrosirius red staining, hydroxyproline, chronic inflammation, mouse model
- MeSH terms
- Aging, Animals, Azo Compounds, Cells, Cultured, Coloring Agents, Extracellular Matrix, Female, Fibrosis, Ovary, Reproduction, Stromal Cells, Inflammation Mediators, Mice
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