Lysosome

Microinjection and transfection studies have demonstrated that Cdc42 induces the formation of filopodia in several mammahan cell types, including fibroblasts and macrophages (Allen et al. 1997, Tapon and Hall 1997). 

Bovine alveolar macrophages cultivated for 20 h were heterogeneous, too (Wilczek 1991). While freshly isolated cells prepared for electron microscopy varied in size from 8.5 [tm to 20 pim with a mean of 13 [xm, in culture cell diameters were from 12 [xm to 40 (xm with a mean of 22 p,m (Fox 1973). 

Bielefeldt Ohman and Babiuk (1984) first used bovine alveolar macrophages for the in vitro generation of superoxide anion and hydrogen peroxide. The spontaneous superoxide anion release was very high immediately after lavage and became almost nil after 20 h, as measured by cytochrome c reduction 20 h after lavage, the electrophoretic profiles obtained 3 or 4 subpopulation (Polzer et al. 1991). 

For an organelle to be interpreted as a lysosome, at least one structural requirement must be met it must have a single hmiting membrane with the relative large dimensions of the exoplasmic space membranes (de Duve 1969). Furthermore, the limiting membrane is commonly separated from the matrix by a clear halo (Daems et al. 1969, Novi-KOFF 1973). 

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One limitation of enzyme replacement therapy is the targeting of enzyme proteins to appropriate sites of substrate accumulation. Administration of a cholesterol esterase conjugated to albumin results in the degradation of pathologic cholesterol ester accumulations within the lysosomes of fibroblasts from a patient with cholesterol ester storage disease (246). 

Golgi apparatus, endoplasmic reticulum, ribosomes, lysosomes, peroxisomes, and cytoskeleton... 

It is a very large vesicle enclosed by a single membrane called the tonoplast. Vacuoles tend to be smaller in young cells, but in mature cells, they may occupy more than 50% of the cell s volume. Vacuoles occupy the center of the cell, with the cytoplasm being located peripherally around it. They resemble the lysosomes of animal cells. 

Mammals, fungi, and higher plants produce a family of proteolytic enzymes known as aspartic proteases. These enzymes are active at acidic (or sometimes neutral) pH, and each possesses two aspartic acid residues at the active site. Aspartic proteases carry out a variety of functions (Table 16.3), including digestion pepsin and ehymosin), lysosomal protein degradation eathepsin D and E), and regulation of blood pressure renin is an aspartic protease involved in the production of an otensin, a hormone that stimulates smooth muscle contraction and reduces excretion of salts and fluid). The aspartic proteases display a variety of substrate specificities, but normally they are most active in the cleavage of peptide bonds between two hydrophobic amino acid residues. The preferred substrates of pepsin, for example, contain aromatic residues on both sides of the peptide bond to be cleaved. 

Cathepsin D Spleen, liver, and many other animal tissues Lysosomal digestion of proteins... 

LTB4, PAF, IL-1, IL-8, reactive oxygen species, lysosomal enzymes... 

A problem with employment of ASON in a larger clinical setting is their poor uptake and inappropriate intracellular compartmentalization, e.g., sequestration in endosomal or lysosomal complexes. In addition, there is a need for a very careful selection of the ASON-mRNA pair sequences that would most efficiently hybridize. To date, several computer programs are used to predict the secondary and tertiary structures of the target mRNA and, in turn, which of the mRNA sequences are most accessible to the ASON. However, even with this sophisticated techniques, the choice of base-pairing partners still usually includes a component of empiricism. Despite these principal limitations, it has become clear that ASON can penetrate into cells and mediate their specific inhibitory effect of the protein synthesis in various circumstances. 

Cathepsins are intracellular proteinases that reside within lysosomes or specific intracellular granules. Cathepsins are used to degrade proteins or pqffides that are internalised from the extracellular space. Some cathepsins such as cathepsin-G or cathepsin-K may be released from the cell to degrade specific extracellular matrix proteins. All cathepsins except cathepsin-G (serine) and cathepsin-D (aspartyl) are cysteine proteinases. 

COPD is a chronic inflammatory disease that results from prolonged and repeated inhalation of particles and gases, chronic (or latent) infection or an interaction of these factors. In many cases, the inflammation persists even when the exposure (in most cases smoking) is stopped. Prominent among the infiltrating leukocytes are neutrophils, CD8+ lymphocytes (Co-receptor for the T-cell receptor. CD8+ is specific for the class IMHC protein. It is expressed on the surface of cytotoxic T-cells and natural killer cells.) and CD68+ monocytic cells (A lysosomal antigen. All cells that rich in... 

C1C-6 is a late endosomal chloride transporter. Its disruption in mice led to lysosomal storage disease. C1C-7 is expressed in late endosomes and lysosomes. It needs Ostml as (3-subunit [3]. The disruption of either C1C-7 or Ostml in mice and man leads to severe osteopetrosis, retinal degeneration, and a severe lysosomal storage disease. ClC-7/Ostml is highly expressed in osteoclasts. In these cells, it is inserted together with the proton pump into the specialized plasma membrane ( ruffled border ) that faces the reabsorption lacuna. Osteoclasts are still present in C1C-7 knockout... 

Lange PF, Wartosch L, Jentsch TJ et al (2006) C1C-7 requires Ostml as a p-subunit to support bone resorption and lysosomal function. Nature 440 220-223... 

Jentsch, TJ (2007) Chloride and the endosomal lysosomal pathway — emerging roles of CLC chloride transporters. J Physiol 578. 3 663-640... 

GM2 gangliosidosis (also known as Tay-Sachs disease) is a rare disorder caused by mutations in the gene encoding the lysosomal, heterodimeric ss-hexosaminidase... 

A (Hex A) catalyzing the biodegradation of gangliosides. Accumulation of gangliosides in lysosomes primarily affects brain neurons. In the early onset form of the disease, children become blind, deaf, and unable to swallow. Children die usually before the age of three. A late onset form ofthe disease occurs in young adults and is usually nonfatal. 

Heriditary lysosomal storage disorder with an heterer-ogeneous clinical presentation including mental retardation and skeletal changes. The disease is caused by... 

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