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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. [ABSTRACT FROM AUTHOR]

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 β-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 β-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. [ABSTRACT FROM AUTHOR]

Peroxisome proliferator-activated receptor γ (PPAR-γ) is a ligand-activated transcriptional factor belonging to the steroid receptor superfamily. PPAR-γ is expressed in multiple normal and neoplastic tissues, such as the breast, colon, lung, ovary and placenta. In addition to adipogenic and anti-inflammatory effects, PPAR-γ activation has been shown to be anti-proliferative by its differentiation-promoting effect, suggesting that activation of PPAR-γ may be useful in slowing or arresting the proliferation of de-differentiated tumour cells. In this study, we investigated the expression of PPAR-γ in normal and neoplastic canine nasal epithelium. Twenty-five samples composed of five normal nasal epithelia and 20 canine nasal carcinomas, were immunohistochemically stained for PPAR-γ. The specificity of the antibody was verified by Western Blot analysis. Confocal laser scanning microscopical investigation was also performed. In normal epithelium, the staining pattern was cytoplasmic and polarized at the cellular free edge. In carcinomas, the neoplastic cells showed mainly strong cytoplasmatic PPAR-γ expression; moreover, perinuclear immunoreactivity was also detected and few neoplastic cells exhibited a nuclear positivity. Our results demonstrate different patterns of PPAR-γ expression in normal canine nasal epithelium when compared with canine nasal carcinoma. The importance of this transcription factor in the pathophysiology of several different tumours has stimulated much research in this field and has opened new opportunities for the treatment of the tumours. [ABSTRACT FROM AUTHOR]

This study evaluates the mitotic phase distribution, mitotic activity and apoptosis in 17 basal cell tumours of canine skin. The number of mitotic and apoptotic cell/mm2 of neoplastic epithelium is counted and the volume corrected mitotic and apoptotic index, respectively, are obtained (M/V and A/V index). Transmission electron microscopy is performed on selected cases to confirm the typical features of apoptosis. The M/V index ranges from 9 to 45/mm2 of neoplastic epithelium, while the A/V index ranges from 5 to 111/mm2 of neoplastic epithelium. Even if the number of apoptotic cells is slightly higher than that of mitotic cells and vice versa, the mean values of the two parameters (mean M/V = 20.76 ± 10.86, mean A/V = 31.41 ± 24.53) tend to be equal. In fact, apoptotic and mitotic index are not statistically different (P = 0.11). Furthermore, in all the samples examined, an increased proportion of metaphases (46.82%) is observed. These findings suggest that the discrepancy between apparent mitotic activity and tumour growth may be mainly due to the increased duration of the entire cell cycle rather than to the high incidence of apoptosis. [ABSTRACT FROM AUTHOR]