Análise morfofuncional de órgãos reprodutivos masculinos e investigação do comportamento sexual em modelo animal de mucopolissacaridose do Tipo I (MPS I)
Data
2018-03-29
Tipo
Tese de doutorado
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Resumo
A Mucopolissacaridose do Tipo I (MPS I) é uma doença de depósito lisossômico causada pela mutação do gene IDUA, codificador da enzima α-L-iduronidase. Trata-se de uma hidrolase lisossômica que degrada heparan e dermatan sulfatos, dois tipos de glicosaminoglicanos (GAGs). GAGs são moléculas estruturais e sinalizadoras, abundantes na matriz extracelular e importantes para a manutenção fisiológica de células e tecidos. Devido à deficiência enzimática, os GAGs são continuamente acumulados em inúmeros tipos celulares, o que caracteriza a doença como multissistêmica e progressiva. Com o aumento da expectativa de vida dos pacientes em decorrência das possibilidades terapêuticas, julgou-se relevante avaliar o efeito da doença sobre parâmetros reprodutivos masculinos e sobre o comportamento sexual do modelo animal de MPS I. Utilizamos camundongos machos C57BL, de 6 meses de idade, com genótipo normal (Idua+/+) e afetado (Idua-/-) para avaliar a morfologia de testículos, epidídimos, vesículas seminais e próstatas. O comportamento sexual foi observado aos 3 e 6 meses de idade. Alguns acasalamentos foram monitorados para que a ocorrência de prenhez fosse registrada. As quantificações hormonais e de GAGs também foram obtidas. Na análise morfológica,
encontramos células intersticiais vacuolizadas em todos os órgãos avaliados referentes ao grupo Idua-/-. Danos epiteliais epididimários foram detectados, embora a morfologia e motilidade espermáticas estivessem mantidas. As vesículas seminais apresentaram menores pesos absolutos e relativos (p=0,013 e p=0,009; respectivamente) e sinais de atrofia, enquanto as próstatas foram bastante comprometidas, contendo alguns ácinos com sinais de necrose. Sob análise ultraestrutural, detectamos alterações nas células mioides, de Leydig e de Sertoli. As últimas com maior quantidade de vesículas contendo material em digestão semelhantes a autofagossomos (p=0,0005) e menor número de vesículas semelhantes a lisossomos (p=0,01). Porém, sob análise molecular, não comprovamos aumento de proteínas autofágicas oriundas do homogenato testicular. Quanto ao comportamento sexual, detectamos maiores latências de montas no grupo Idua-/- independentemente da idade (p=0,05) e também de intromissões no grupo Idua-/- de 3 meses (p=0,02), provavelmente devido à limitação motora comprovada pelo teste do campo aberto, que indicou menor atividade horizontal e vertical independentemente da idade dos animais Idua-/- (p=0,01 e p=0,04 respectivamente). As concentrações de hormônios foram similares entre os grupos e houve acúmulo de dermatan sulfato nos testículos (p<0,0001), epidídimos (p=0,007) e próstatas (p=0,0004). Concluímos que a deficiência da enzima IDUA afeta a morfologia de importantes órgãos reprodutivos, porém, os gametas são morfologicamente normais e móveis. Embora apresentem limitações motoras, machos Idua-/- são aptos à copula e muitos foram capazes de emprenhar fêmeas e gerar filhotes.
Mucopolysaccharidosis Type I (MPS I) is a lysosomal storage disease caused by a mutation of IDUA gene. IDUA codes α-L-iduronidase, a lysosomal hydrolase that degrades heparan and dermatan sulfates, two types of glycosaminoglycans (GAGs). GAGs are structural and signaling molecules, abundant in extracellular matrix and important to maintain cell and tissue physiology. Due to the unsuitable and progressive storage of GAGs in many cell types, MPS I is a multisystemic disease and has been investigated in patients and animal models. The enzyme replacement therapy is available to MPS I patients and has improved their life expectancy. In the present work, our goal was to characterize the male reproductive tract of a murine model of MPS I, as well as to examine their sexual behavior, in order to investigate the effect of this multisystemic disease to gametes production, fecundity and sexual performance. We used C57BL Idua+/+ and Idua-/- male mice, all adults (6-month-old), to investigate the morphology of testes, epididymis, seminal vesicles and prostates. Sexual behavior was assessed in two different stages of disease progression: 3 and 6-month-old. Systematic matings were performed to evaluate male capacity to impregnate females. Hormonal and GAG quantifications were also performed. In our morphological analysis we found signs of damage in the interstitial compartment of all examined organs, with abundant vacuolated cells. Idua-/- presented more epithelial damage in the epididymis, regardless of the normal sperm morphology and motility. Seminal vesicles presented lower absolute and relative weights (p=0,013 and p=0,009 respectively), with subtle signs of atrophy, while prostates presented some necrotic acini. Under testicular ultrastructural analyzes, we noted pathological signs especially in peritubular myoid cells and in the steroidogenic Leydig cells. Sertoli cells presented more vesicles containing materials under digestion similar to autophagosomes (p=0.0005) and less vesicles similar to lysosomes (p=0.01). However, we could not demonstrate that autophagy was more activated with our molecular analysis obtained from testicular homogenates. Regarding sexual behavior, we detected higher latencies for mount in Idua-/- independently of age (p=0.05), and for intromission in 3-month-old Idua-/- mice (p=0.02). Motor limitations were confirmed with less horizontal and vertical activities in Idua-/- group, independently of age (p=0.01 and p=0.04 respectively). Steroid hormone concentrations were similar between groups and we found higher concentrations of dermatan sulfate in testis (p<0.0001), epididymis (p=0.007) and prostates (p=0.0004) of Idua-/- group. Fecundity was not impaired and litter size was similar between groups. We concluded that the absence of IDUA affects the morphology of important reproductive organs, regardless of normal sperm appearance and motility. Six- month-old Idua-/- mice present a less effective sexual performance possibly due to motor limitations, however, they are capable of copulating and generating pups.
Mucopolysaccharidosis Type I (MPS I) is a lysosomal storage disease caused by a mutation of IDUA gene. IDUA codes α-L-iduronidase, a lysosomal hydrolase that degrades heparan and dermatan sulfates, two types of glycosaminoglycans (GAGs). GAGs are structural and signaling molecules, abundant in extracellular matrix and important to maintain cell and tissue physiology. Due to the unsuitable and progressive storage of GAGs in many cell types, MPS I is a multisystemic disease and has been investigated in patients and animal models. The enzyme replacement therapy is available to MPS I patients and has improved their life expectancy. In the present work, our goal was to characterize the male reproductive tract of a murine model of MPS I, as well as to examine their sexual behavior, in order to investigate the effect of this multisystemic disease to gametes production, fecundity and sexual performance. We used C57BL Idua+/+ and Idua-/- male mice, all adults (6-month-old), to investigate the morphology of testes, epididymis, seminal vesicles and prostates. Sexual behavior was assessed in two different stages of disease progression: 3 and 6-month-old. Systematic matings were performed to evaluate male capacity to impregnate females. Hormonal and GAG quantifications were also performed. In our morphological analysis we found signs of damage in the interstitial compartment of all examined organs, with abundant vacuolated cells. Idua-/- presented more epithelial damage in the epididymis, regardless of the normal sperm morphology and motility. Seminal vesicles presented lower absolute and relative weights (p=0,013 and p=0,009 respectively), with subtle signs of atrophy, while prostates presented some necrotic acini. Under testicular ultrastructural analyzes, we noted pathological signs especially in peritubular myoid cells and in the steroidogenic Leydig cells. Sertoli cells presented more vesicles containing materials under digestion similar to autophagosomes (p=0.0005) and less vesicles similar to lysosomes (p=0.01). However, we could not demonstrate that autophagy was more activated with our molecular analysis obtained from testicular homogenates. Regarding sexual behavior, we detected higher latencies for mount in Idua-/- independently of age (p=0.05), and for intromission in 3-month-old Idua-/- mice (p=0.02). Motor limitations were confirmed with less horizontal and vertical activities in Idua-/- group, independently of age (p=0.01 and p=0.04 respectively). Steroid hormone concentrations were similar between groups and we found higher concentrations of dermatan sulfate in testis (p<0.0001), epididymis (p=0.007) and prostates (p=0.0004) of Idua-/- group. Fecundity was not impaired and litter size was similar between groups. We concluded that the absence of IDUA affects the morphology of important reproductive organs, regardless of normal sperm appearance and motility. Six- month-old Idua-/- mice present a less effective sexual performance possibly due to motor limitations, however, they are capable of copulating and generating pups.
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Citação
NASCIMENTO, Cinthia Castro do. Análise morfofuncional de órgãos reprodutivos masculinos e investigação do comportamento sexual em modelo animal de mucopolissacaridose do Tipo I (MPS I). 2018. 107 f. Tese (Doutorado em Psicobiologia) - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, 2018.