Research Article OsteoarthritisAffectsMammalianOogenesis:Effectsof Collagenase-InducedOsteoarthritisonOocyteCytoskeletonina MouseModel AntonIvanovKolarov,IrinaValchevaChakarova,ValentinaProdanovaHadzhinesheva, VeneraPantaleevaNikolova,StefkaMetodievaDelimitreva,MayaDyankovaMarkova, andRalitsaStefanovaZhivkova Department of Biology, Medical Faculty, Medical University—Sofia, 2 Zdrave Str, 1431 Sofia, Bulgaria Correspondence should be addressed to Ralitsa Stefanova Zhivkova; rzhivkova@yahoo.com Received 6 April 2021; Revised 12 October 2021; Accepted 18 October 2021; Published 9 November 2021 Academic Editor: Newman Osafo Copyright © 2021 Anton Ivanov Kolarov et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Known as a degenerative joint disorder of advanced age affecting predominantly females, osteoarthritis can develop in younger and actively working people because of activities involving loading and injuries of joints. Collagenase-induced osteoarthritis (CIOA) in a mouse model allowed us to investigate for the first time its effects on key cytoskeletal structures (meiotic spindles and actin distribution) of ovulated mouse oocytes. eir meiotic spindles, actin caps, and chromatin were analyzed by immuno- fluorescence. A total of 193 oocytes from mice with CIOA and 209 from control animals were obtained, almost all in metaphase I (M I) or metaphase II (MII). e maturation rate was lower in CIOA (26.42% M II) than in controls (55.50% M II). CIOA oocytes had significantly larger spindles (average 37 μm versus 25 μm in controls, p < 0.001), with a proportion of large spindles more than 64% in CIOA versus up to 15% in controls (p < 0.001). Meiotic spindles were wider in 68.35% M I and 54.90% M II of CIOA oocytes (mean 18.04 μm M I and 17.34 μm M II versus controls: 11.64 μm M I and 12.64 μm M II), and their poles were ap- proximately two times broader (mean 6.9 μm) in CIOA than in controls (3.6 μm). CIOA oocytes often contained disoriented microtubules. Actin cap was visible in over 91% of controls and less than 20% of CIOA oocytes. Many CIOA oocytes without an actin cap had a nonpolarized thick peripheral actin ring (61.87% of M I and 52.94% of M II). Chromosome alignment was normal in more than 82% in both groups. In conclusion, CIOA affects the cytoskeleton of ovulated mouse oocytes—meiotic spindles are longer and wider, their poles are broader and with disorganized fibers, and the actin cap is replaced by a broad nonpolarized ring. Nevertheless, meiotic spindles were successfully formed in CIOA oocytes and, even when abnormal, allowed correct alignment of chromosomes. 1.Introduction Osteoarthritis is an age-related degenerative condition of joints characterized by cartilage destruction, abnormal bone remodeling, pain, swelling, and limited range of motion. It affects a significant proportion of older people, has a neg- ative impact on their quality of life and workability, and leads to increased medical costs and care dependency. Osteoarthritis depends not only on age but also on sex, being more common in women than in men [1, 2]. Other known risk factors include obesity, number of pregnancies and births, and hormone replacement therapy. Studies on the combined action of risk factors have revealed additive and multiplicative effects when reproductive and hormonal factors of premenopausal female life (e.g., a high number of pregnancies and oral contraceptives usage) are followed by postmenopausal factors such as hormone replacement therapy and/or obesity [1, 3–5]. Birth parameters such as preterm delivery and low body weight of the newborn are associated with an increased risk of osteoarthritis in the adult Hindawi International Journal of Inflammation Volume 2021, Article ID 8428713, 12 pages https://doi.org/10.1155/2021/8428713