Correlation Study Between Canine Ovarian Cyst Occurrence And Testosterone

Ovarian cysts are common reproductive system diseases in canine that can cause disturbances in the estrus cycle and abnormal ovulation in female canine,leading to infertility.In this paper,46 cases of canine ovarian cyst were used as experimental objects,and by observing the clinical data of their nutritional status,hematology and imaging,and combining them with in vitro cells,the purpose of this paper is to provide reference and basis for the diagnosis and treatment of canine ovarian cyst.Most of the canine ovarian cyst in this study were middle-aged and elderly canine,with 34 cases over 7 years old.Through the blood routine examination,it was found that the number of neutrophils,lymphocytes,and monocytes in the serum of the canine ovarian cyst increased,accompanied by a decrease in the level of red blood cells and hemoglobin.At the same time,liver and kidney dysfunction occurs in canine ovarian cyst.Further studies found significant increases in testosterone（Testosterone,T）,estradiol（Estradiol,E₂）and progesterone（Progesterone,P₄）levels in the serum of canine ovarian cyst.But the relationship between testosterone and the occurrence of canine ovarian cyst is unclear.Testosterone is a steroid hormone secreted by the testes of males or the ovaries of females,and in small amounts by the adrenal glands.This subject takes ovarian granulosa cells as the research object in vitro to study the effect of testosterone on ovarian granulosa cell and its functional mechanism.The results showed that 100μM testosterone significantly increased the levels of reactive oxygen species（ROS）,superoxide anion（O₂^-）and mitochondrial reactive oxygen species（Mito ROS）in ovarian granulosa cells,while the activity of glutathione peroxidase（GPX）and glutathione reductase（GR）and the content of glutathione（GSH）were significantly reduced,resulting in an increase of malondialdehyde（MDA）content in ovarian granulosa cells.Further testing found that testosterone can reduce the mitochondrial membrane potential and increase the apoptosis rate of ovarian granulosa cells.In order to explore whether transcriptional coactivator with PDZ-binding motif（Transcriptional coactivator with PDZ-binding motif,TAZ）can mediate the effect of testosterone on ovarian granulosa cell function,the changes of TAZ expression were detected by Real-Time PCR and Western blot.The results showed that testosterone could significantly inhibit the expression of TAZ m RNA and protein.Transfection of TAZ overexpression vector ameliorated the effect of testosterone on ROS,O₂^-,Mito ROS levels,increased GPX and GR activities and GSH content,and attenuated the content of MDA in testosterone-treated ovarian granulosa cells.In order to investigate whether testosterone can regulate Nrf2 expression through TAZ,testosterone was added after transfection of TAZ overexpression vector,and it was found that testosterone could reduce the expression of Nrf2 in ovarian granulosa cells,while overexpression of TAZ reversed the inhibitory effect of testosterone on Nrf2.Further study found that testosterone can inhibit the expression of Foxo1 m RNA in ovarian granulosa cells,while overexpression of TAZ can eliminate the inhibitory effect of testosterone on Foxo1,but the regulation of Foxo1 by TAZ can be antagonized by the Nrf2 inhibitor ML385.Ovarian granulosa cells were transfected with TAZ overexpression vector and added with testosterone and Nrf2 inhibitor ML385 or Foxo1 inhibitor AS1842856.It was found by flow cytometry or fluorescence microscopy that inhibition of Nrf2 and Foxo1 could increase the levels of ROS,O₂^-,Mito ROS and ROS in cells.MDA levels significantly increased,while GPX and GR activities and GSH content decreased,mitochondrial membrane potential decreased,mitochondrial permeability transition pore opened,cytochrome C released and apoptosis rate increased.In conclusion,testosterone significantly increased in serum of canine ovarian cyst,which can increase the level of ROS in ovarian granulosa cells and reduce the antioxidant capacity of cells by inhibiting the TAZ-Nrf2-Foxo1 pathway,causing mitochondrial dysfunction,resulting in cytochrome C from Mitochondria are released into the cytoplasm,triggering apoptosis of granulosa cells,and then participating in the occurrence of canine ovarian cysts.