Warning: file_get_contents(https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=26801085
&cmd=llinks): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 215
Degradation of aggregated LDL occurs in complex extracellular sub-compartments of
the lysosomal synapse
#MMPMID26801085
Singh RK
; Barbosa-Lorenzi VC
; Lund FW
; Grosheva I
; Maxfield FR
; Haka AS
J Cell Sci
2016[Mar]; 129
(5
): 1072-82
PMID26801085
show ga
Monocyte-derived cells use an extracellular, acidic, lytic compartment (a
lysosomal synapse) for initial degradation of large objects or species bound to
the extracellular matrix. Akin to osteoclast degradation of bone, extracellular
catabolism is used by macrophages to degrade aggregates of low density
lipoprotein (LDL) similar to those encountered during atherogenesis. However,
unlike osteoclast catabolism, the lysosomal synapse is a highly dynamic and
intricate structure. In this study, we use high resolution three dimensional
imaging to visualize compartments formed by macrophages to catabolize aggregated
LDL. We show that these compartments are topologically complex, have a convoluted
structure and contain sub-regions that are acidified. These sub-regions are
characterized by a close apposition of the macrophage plasma membrane and
aggregates of LDL that are still connected to the extracellular space.
Compartment formation is dependent on local actin polymerization. However, once
formed, compartments are able to maintain a pH gradient when actin is
depolymerized. These observations explain how compartments are able to maintain a
proton gradient while remaining outside the boundaries of the plasma membrane.
free
free
free
