Amyloid precursor protein, lipofuscin accumulation and expression of autophagy markers in aged bovine brain.

BACKGROUND: Autophagy is a highly regulated process involving the bulk degradation of cytoplasmic macromolecules and organelles in mammalian cells via the lysosomal system. Dysregulation of autophagy is implicated in the pathogenesis of many neurodegenerative diseases and integrity of the autophagosomal - lysosomal network appears to be critical in the progression of aging. Our aim was to survey the expression of autophagy markers and Amyloid precursor protein (APP) in aged bovine brains. For our study, we collected samples from the brain of old (aged 11-20 years) and young (aged 1-5 years) Podolic dairy cows. Formalin-fixed and paraffin embedded sections were stained with routine and special staining techniques. Primary antibodies for APP and autophagy markers such as Beclin-1 and LC3 were used to perform immunofluorescence and Western blot analysis. RESULTS: Histologically, the most consistent morphological finding was the age-related accumulation of intraneuronal lipofuscin. Furthermore, in aged bovine brains, immunofluorescence detected a strongly positive immunoreaction to APP and LC3. Beclin-1 immunoreaction was weak or absent. In young controls, the immunoreaction for Beclin-1 and LC3 was mild while the immunoreaction for APP was absent. Western blot analysis confirmed an increased APP expression and LC3-II/LC3-I ratio and a decreased expression of Beclin-1 in aged cows. CONCLUSIONS: These data suggest that, in aged bovine, autophagy is significantly impaired if compared to young animals and they confirm that intraneuronal APP deposition increases with age.

Age-Related Changes in Skeletal Muscle of Cattle.

Sarcopenia, the age-related loss of muscle mass and strength, is a multifactorial condition that represents a major healthcare concern for the elderly population. Although its morphologic features have been extensively studied in humans, animal models, and domestic and wild animals, only a few reports about spontaneous sarcopenia exist in other long-lived animals. In this work, muscle samples from 60 healthy Podolica-breed old cows (aged 15-23 years) were examined and compared with muscle samples from 10 young cows (3-6 years old). Frozen sections were studied through standard histologic and histoenzymatic procedures, as well as by immunohistochemistry, immunofluorescence, and Western blot analysis. The most prominent age-related myopathic features seen in the studied material included angular fiber atrophy (90% of cases), mitochondrial alterations (ragged red fibers, 70%; COX-negative fibers, 60%), presence of vacuolated fibers (75%), lymphocytic (predominantly CD8+) inflammation (40%), and type II selective fiber atrophy (40%). Immunohistochemistry revealed increased expression of major histocompatibility complex I in 36 cases (60%) and sarcoplasmic accumulations of ß-amyloid precursor protein-positive material in 18 cases (30%). In aged cows, muscle atrophy was associated with accumulation of myostatin. Western blot analysis indicated increased amount of both proteins-myostatin and ß-amyloid precursor protein-in muscles of aged animals compared with controls. These findings confirm the presence of age-related morphologic changes in cows similar to human sarcopenia and underline the possible role of amyloid deposition and subsequent inflammation in muscle senescence.

Mature teratoma arising from an undescended testis in a horse: comparison between ultrasonographic and morphological features.

Scant information is available on the ultrasonographic appearance of different testicular tumours in the stallion. Preoperative ultrasound imaging and gross and microscopic features of a testicular teratoma in a horse is described. An asymptomatic 4 years old cryptorchid Arabian horse was admitted for orchiectomy. Combined transabdominal and inguinal ultrasound examination revealed a large complex ovoid mass, containing both solid and cystic elements with internal echoes, located dorsally to the superficial inguinal ring. Two main hypoechoic cavities divided by a linear hyperechoic septum were evident, with a hyperechoic circular structure inside the lumen of the largest one. A tumour of the undescended testis was suspected. Ultrasound findings guided a provisional diagnosis of teratoma that was confirmed by histology following surgical removal of the tumour. Due to the correspondence between ultrasonographic and morphological features, trans-abdominal ultrasonography was conclusive in the preoperative planning.

Muscular dystrophy in a dog resembling human becker muscular dystrophy.

A 3-year-old, male Labrador retriever dog was presented with clinical signs of progressive exercise intolerance, bilateral elbow extension, rigidity of the forelimbs, hindlimb flexion and kyphosis. Microscopical examination of muscle tissue showed marked variability in myofibre size, replacement of muscle with mature adipose tissue and degeneration/regeneration of muscle fibres, consistent with muscular dystrophy. Immunohistochemical examination for dystrophin showed markedly reduced labelling with monoclonal antibodies specific for the rod domain and the carboxy-terminal of dystrophin, while expression of ß-sarcoglycan, γ-sarcoglycan and ß-dystroglycan was normal. Immunoblotting revealed a truncated dystrophin protein of approximately 135 kDa. These findings supported a diagnosis of congenital canine muscular dystrophy resembling Becker muscular dystrophy in man.