Search results for "Lysosome"
showing 10 items of 125 documents
Lysosomal cathepsins B and L and Stefin A blood levels in patients with hepatocellular carcinoma and/or liver cirrhosis: potential clinical implicati…
1997
The serum levels of lysosomal cathepsin B and L and Stefin A, an intracellular inhibitor of these proteolytic enzymes, were determined in patients with hepatocellular carcinoma (HCC) and/or liver cirrhosis (LC) and correlated with some clinical and biochemical parameters of these diseases. Cathepsin B serum levels were increased in HCC and in LC patients as compared to normal subjects (p < 0.001). However no difference was observed between HCC and LC groups. Interestingly, a significant relationship was evidenced between cathepsin B serum content and the grade of severity of cirrhosis (r = 0.41; p < 0.001). Cathepsin L was significantly elevated only in sera of cancer patients as comp…
Hearing impairment as an early sign of alpha-mannosidosis in children with a mild phenotype: Report of seven new cases.
2019
Alpha-mannosidosis (AM) is a very rare (prevalence: 1/500000 births) autosomal recessive lysosomal storage disorder. It is characterized by multi-systemic involvement associated with progressive intellectual disability, hearing loss, skeletal anomalies, and coarse facial features. The spectrum is wide, from very severe and lethal to a milder phenotype that usually progresses slowly. AM is caused by a deficiency of lysosomal alpha-mannosidase. A diagnosis can be established by measuring the activity of lysosomal alpha-mannosidase in leucocytes and screening for abnormal urinary excretion of mannose-rich oligosaccharides. Genetic confirmation is obtained with the identification of MAN2B1 muta…
Studies on the subcellular pathophysiology of sublethal chronic cell injury.
1974
Summary This paper summarizes some of the important subcellular events occurring after chronic sublethal cell injury. Chronic cell injury is defined as the result of injurious stimuli which permit cell survival though in altered steady states for protracted periods of time. The importance of ultrastructural and biochemical studies of these phenomena is emphasized. Among the phenomena discussed are alterations in lysosomes, cellular hypertrophy, fatty metamorphosis, alterations in microfilaments and microtubules, alterations in mechanisms of transcription and replication, disturbances in the cell surface and transport across the cell membrane, and alterations in intracellular transport.
Phosphomannosyl receptors of lysosomal enzymes of skeletal muscle in neuromuscular diseases.
1988
The phosphomannosyl receptor system is responsible for both the receptor-mediated endocytosis and the intracellular transport of lysosomal enzymes. In the present study this receptor system was examined in affected muscles of patients with various neuromuscular diseases. The total activity of beta-N-acetyl-glucosaminidase, a marker enzyme of lysosomal hydrolases, was significantly elevated in the patients with myopathies (polymyositis and muscular dystrophies) but only slightly increased in those with neurogenic muscle atrophies (amyotrophic lateral sclerosis, polyneuropathy or other neurogenic muscle disease). The increase was most prominent in the group of polymyositis. The content of pho…
Lysosomal aspartic and cysteine proteinases serum levels in patients with pancreatic cancer or pancreatitis
1997
Lysosomal cathepsins D (CD), B (CB), and L (CL) serum levels were determined by immunoassays in patients with chronic (CHP) or acute (AP) pancreatitis and in patients with ductal pancreatic carcinoma (DPC) and correlated with some biological and clinical parameters of this tumor. CB serum concentrations significantly higher than those measured in healthy subjects (NS) were observed in CHP, AP, and DPC patients (p < 0.01). However, no significant difference was noted among these groups. Increased CL serum levels were evident only in cancer patients compared to NS, AP, or CHP groups (p < 0.05), while no difference was observed among these groups. Elevated CD serum values were observed i…
Morphologic diagnosis in neuronal ceroid lipofuscinosis.
1997
Morphologic pathology in NCL is marked by two processes, the interaction of which has not yet been completely clarified: 1) degeneration of nerve cells, foremost in the cerebral cortex, resulting in considerable cerebral atrophy in early childhood forms, likely responsible for clinical and neuroradiological findings; 2) widespread accumulation of autofluorescent lysosomal lipopigments of varying ultrastructure, the demonstration of which is still largely responsible for diagnostic recognition of an individual patient's NCL. Numerous tissues and organs are available for biopsy, among them brain (historical), rectum (still favoured by some), skeletal muscle and peripheral nerves (largely by c…
Intramembrane particles and filipin labelling on the membranes of autophagic vacuoles and lysosomes in mouse liver
1989
Morphologically detectable protein (intramembrane particles) and cholesterol (filipin labelling) in the membranes of autophagic vacuoles and lysosomes were studied in mouse hepatocytes using thin-section and freeze-fracture electron microscopy. Both isolated autophagic vacuoles and lysosomes, and intact tissue blocks were used due to the facts (i) that lysosomes are difficult to recognize in freeze-fracture replicas of intact hepatocytes, and (i) that filipin penetration into the tissue blocks is unsatisfactory. Intramembrane particle density was low in the membranes of early autophagic vacuoles (defined as round-shaped vacuoles in which an inner membrane parallel with the outer limiting me…
Artesunate Activates Mitochondrial Apoptosis in Breast Cancer Cells via Iron-catalyzed Lysosomal Reactive Oxygen Species Production
2011
The antimalarial agent artesunate (ART) activates programmed cell death (PCD) in cancer cells in a manner dependent on the presence of iron and the generation of reactive oxygen species. In malaria parasites, ART cytotoxicity originates from interactions with heme-derived iron within the food vacuole. The analogous digestive compartment of mammalian cells, the lysosome, similarly contains high levels of redox-active iron and in response to specific stimuli can initiate mitochondrial apoptosis. We thus investigated the role of lysosomes in ART-induced PCD and determined that in MCF-7 breast cancer cells ART activates lysosome-dependent mitochondrial outer membrane permeabilization. ART impac…
Expression Patterns and Subcellular Localization of Carbonic Anhydrases Are Developmentally Regulated during Tooth Formation
2014
Abstract Carbonic anhydrases (CAs) play fundamental roles in several physiological events, and emerging evidence points at their involvement in an array of disorders, including cancer. The expression of CAs in the different cells of teeth is unknown, let alone their expression patterns during odontogenesis. As a first step towards understanding the role of CAs during odontogenesis, we used immunohistochemistry, histochemistry and in situ hybridization to reveal hitherto unknown dynamic distribution patterns of eight CAs in mice. The most salient findings include expression of CAII/Car2 not only in maturation-stage ameloblasts (MA) but also in the papillary layer, dental papilla mesenchyme, …
Recessive mutations in EPG5 cause Vici syndrome, a multisystem disorder with defective autophagy
2013
Vici syndrome is a recessively inherited multisystem disorder characterized by callosal agenesis, cataracts, cardiomyopathy, combined immunodeficiency and hypopigmentation. To investigate the molecular basis of Vici syndrome, we carried out exome and Sanger sequence analysis in a cohort of 18 affected individuals. We identified recessive mutations in EPG5 (previously KIAA1632), indicating a causative role in Vici syndrome. EPG5 is the human homolog of the metazoan-specific autophagy gene epg-5, encoding a key autophagy regulator (ectopic P-granules autophagy protein 5) implicated in the formation of autolysosomes. Further studies showed a severe block in autophagosomal clearance in muscle a…