Meio condicionado de células tronco mesenquimais como tratamento de endometrose em éguas

Abstract

Durante a vida reprodutiva das éguas o endométrio é exposto a eventos como: cópula, parto, puerpério e infecções. Tais circunstâncias podem levar gradativamente a diminuição da capacidade funcional do endométrio com queda da fertilidade. O objetivo deste estudo foi avaliar o efeito do tratamento com o meio condicionado de células tronco mesenquimais sobre o endométrio de éguas com fibrose uterina através de avaliação histopatológica. No experimento 1, 21 éguas que não pariram pelo menos em duas temporadas foram avaliadas por meio de exames ultrassonográfico, citológico, bacteriológico e histopatológico. No experimento 2, das 21 éguas avaliadas, quatro éguas classificadas como grau II e duas éguas classificadas como grau III na histopatologia endometrial, foram submetidas a infusão uterina com o meio condicionado de células tronco mesenquimais para promover a regeneração endometrial. No experimento 1, a presença de edema uterino foi observada em 81% (17/21) das fêmeas líquido intrauterino em 23,81% (5/21) e cistos uterinos em 57,14% das éguas (12/21). O crescimento bacteriano identificado em 42,90% (9/21) das éguas pelo exame bacteriológico revelou predominância de Escherichia coli (4/21). O exame citológico revelou processo inflamatório em 44,40% das fêmeas (4/9) com crescimento bacteriano, enquanto 16,70% (2/12) das éguas sem crescimento bacteriano tinham presença de processo inflamatório (P = 0,331). A inflamação uterina foi detectada em 28,60% (6/21) das éguas. A biópsia uterina e avaliação histopatológica revelou 14,30% (3/21) das éguas pertencentes à classe Grau I, 47,60% Grau II (10/21) e 38,10% Grau III (8/21). Verificou-se correlação positiva significativa (r = 0,69; P = 0,0005) entre o grau de endometrose pelo Índice de Caslick e o grau atribuído após exame histopatológico. Maior percentual de éguas com índice Caslick superior a 200 foi observado (P= 0,0242) em éguas classificadas como Grau III (87,5%; 7/8) do que Grau I (0,0%; 0/3). Não houve diferença (P= 0,59) entre as éguas Grau III e as Grau II (70%; 7/10); estas últimas tenderam (P= 0,07) a ter maior percentual com índice Caslick acima 5 de 200 do que as fêmeas com Grau I. O índice Caslick médio comparado entre os graus histológicos revelou maior índice nas éguas Grau III do que nas éguas Grau I (252,0 vs 78,3; P= 0,007). As éguas com Grau II apresentaram índice intermediário (174,6). Não houve associação entre a presença de cistos uterinos e o grau histopatológico das biópsias (P= 0,813). Éguas com cistos uterinos tiveram 16,7%, 41,7% e 41,7% das biópsias classificadas no exame histológico como Graus I, II e III, respectivamente. Esses percentuais nas éguas sem cistos foram de 11,1%, 55,6% e 33,3%, para os Graus I, II e III, respectivamente. A idade média das fêmeas foi similar (P= 0,112) entre as fêmeas com e sem cistos uterinos (20,3 vs 16,3 anos). No experimento 2, a aplicação de 20 mL de meio condicionado de células tronco no lúmen uterino das seis éguas com endometrose grau II e III não resultou em melhoria na condição endometrial.

During the mare reproductive life, the endometrium is exposed to events such as copulation, parturition, puerperium, and infections. Such circumstances may gradually lead to a decrease in the functional capacity of the endometrium, resulting in a drop in fertility. The objective of this study was to evaluate, by using ultrasonographic, cytological, bacteriological, and histopathological exams, the effect of a treatment with mesenchymal stem cell-conditioned medium on the endometrium of 21 mares with uterine fibrosis that did not foal in at least two seasons. In experiment 1, 21 mares were evaluated by using ultrasonographic, cytological, bacteriological and histopathological exams. In experiment 2, from the total 21 females, four mares classified by the endometrial histopathology as grade II and two mares classified as grade III were submitted to uterine infusion with mesenchymal stem cell-conditioned medium to promote the endometrial regeneration. In experiment 1, the evaluation revealed the presence of uterine edema in 81% (17/21), intrauterine liquid in 23.81% (5/21), and uterine cysts in 57.14% of the mares (12/21). Bacteriological examination revealed that 42.86% (9/21) of the mares showed bacterial growth, and the microorganism with the highest incidence was Escherichia coli (4/21). The cytological exam showed inflammatory process in 44.40% (4/9) of the females with bacterial growth, while 16.70% (2/12) of the mares without bacterial growth showed inflammatory process (P = 0.331). Uterine inflammatory process was observed in 28.60% (6/21) of the mares. It was possible to identify by using uterine biopsy and histopathological evaluation that 14.30% (3/21), 47.60% (10/21), and 38.10% (8/21) of mares belong to Grade I, II and III, respectively. There was a significant positive correlation (r = 0.69, P = 0.0005) between the degree of endometrosis evaluated by the Caslick Index and the grade attributed after histopathological examination. The percentage of mares with Caslick index over 200 was higher in females classified as grade III (P= 0.0242) than in grade I females (0.0%; 0/3). There was no difference between mares grade III and grade II 7 (70%; 7/10). Grade II females tended to have a higher percentage with Caslick index above 200 (P = 0.07) when compared to the grade I females. The medium Caslick index compared between the histological grades revealed a higher index in grade III than in grade I mares (252.0 vs 78.3, P = 0.007). Mares grade II showed intermediate index (174.6). There was no association between the presence of uterine cysts and the histopathological grade of biopsies (P = 0.813). Mares with uterine cysts had 16.70%, 41.70%, and 41.70% of the biopsies classified in the histological examination as grades I, II, and III, respectively. The percentages in mares without cysts were 11.10%, 55.60%, and 33.30%, respectively, for Grade I, II and III. The mares mean age was similar (P=0.112) among females with or without uterine cysts (20.3 vs 16.3 years). In experiment 2, the application of 20 mL of mesenchymal stem cell-conditioned medium in the uterine lumen of six mares with endometrosis Grade II and III did not improve the endometrial condition.