Direct binding of sulfur mustard and chloroethyl ethyl sulphide to human cell membrane-associated proteins; implications for sulfur mustard pathology

Pemphigus is a chronic mucocutaneous autoimmune bullous disease that is characterized by loss of cell-cell contact in skin and/or mucous membranes. Past research has successfully identified desmosomes as immunological targets and has demonstrated that acantholysis is initiated through direct binding of IgG. The exact mechanisms of acantholysis, however, are still missing. Experimental model systems have contributed considerably to today's knowledge and are still a favourite tool of research. In this paper we will describe to what extent human cell and tissue models represent the in vivo situation, for example, organ cultures of human skin, keratinocyte cultures, and human skin grafted on mice and, furthermore, how suitable they are to study the pathogenesis of pemphigus. Organ cultures closely mimic the architecture of the epidermis but are less suitable to answer posed biochemical questions. Cultured keratinocyte monolayers are convenient in this respect, but their desmosomal make-up in terms of adhesion molecules does not exactly reflect the in vivo situation. Reconstituted skin is a relatively new model that approaches organ culture. In models of human skin grafted on mice, acantholysis can be studied in actual human skin but now with all the advantages of an animal model.

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Neisseria gonorrhoeae Coordinately Uses Pili and Opa To Activate HEC-1-B Cell Microvilli, Which Causes Engulfment of the Gonococci

Infection and Immunity ◽

10.1128/iai.67.7.3469-3480.1999 ◽

1999 ◽

Vol 67 (7) ◽

pp. 3469-3480 ◽

Cited By ~ 44

Author(s):

J. McLeod Griffiss ◽

Claudia J. Lammel ◽

Jun Wang ◽

Nusi P. Dekker ◽

G. F. Brooks

Keyword(s):

Protein Synthesis ◽

B Cells ◽

Cell Membrane ◽

Neisseria Gonorrhoeae ◽

B Cell ◽

Low Doses ◽

Eukaryotic Protein ◽

Associated Proteins ◽

Dose Dependent ◽

Higher Doses

ABSTRACT This study was undertaken to examine concomitant roles of pili and colony opacity-associated proteins (Opa) in promoting Neisseria gonorrhoeae adherence to and invasion of human endometrial HEC-1-B cells. Adherence of N. gonorrhoeae to cultured HEC-1-B cells was saturable, even though organisms adhered to <50% of the cells. During 4 to 6 h of incubation, adherent mono- and diplococci formed microcolonies on the surfaces of the cells. Microvilli of the HEC-1-B cells adhered by their distal ends to individual cocci within the microcolonies. When the microcolonies grew from isogenic pilus-negative (P−) Opa−, P− Opa+, or P+ Opa−gonococci, microvilli did not elongate, and the colonies were not engulfed. In contrast, the microvilli markedly elongated during exposure to P+ Opa+ gonococci. The microvilli adhered to the organisms along their full lengths and appeared to actively participate in the engulfment of the microcolonies. Internalized microcolonies, with P+ Opa+gonococci, contained dividing cocci and appeared to be surrounded by cell membrane but were not clearly within vacuoles. In contrast, degenerate individual organisms were within vacuoles. Low doses of chloramphenicol, which inhibits protein synthesis by both prokaryotes and eukaryotes, prevented the microvillar response to and internalization of the P+ Opa+ gonococci; higher doses caused internalization without microvillus activation. Cycloheximide and anisomycin, which inhibit only eukaryotic protein synthesis, caused dose-dependent enhancement of uptake. Cytochalasins reduced engulfment; colchicine had no effect. These results show that gonococci must express both pili and Opa to be engulfed efficiently by HEC-1-B cells.

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Flotillin-mediated endocytosis and ALIX–syntenin-1–mediated exocytosis protect the cell membrane from damage caused by necroptosis

Science Signaling ◽

10.1126/scisignal.aaw3423 ◽

2019 ◽

Vol 12 (583) ◽

pp. eaaw3423 ◽

Cited By ~ 18

Author(s):

Weiliang Fan ◽

Jia Guo ◽

Beichen Gao ◽

Wenbin Zhang ◽

Liucong Ling ◽

...

Keyword(s):

Plasma Membrane ◽

Cell Membrane ◽

Lipid Raft ◽

Affinity Purification ◽

Human Diseases ◽

Membrane Disruption ◽

Cross Linking ◽

Lysosomal Degradation ◽

Regulated Necrosis ◽

Associated Proteins

Necroptosis is a form of regulated necrosis that is implicated in various human diseases including Alzheimer’s disease. Necroptosis requires the translocation of the pseudokinase MLKL from the cytosol to the plasma membrane after its phosphorylation by the kinase RIPK3. Using protein cross-linking followed by affinity purification, we detected the lipid raft–associated proteins flotillin-1 and flotillin-2 and the ESCRT-associated proteins ALIX and syntenin-1 in membrane-localized MLKL immunoprecipitates. Phosphorylated MLKL was removed from membranes through either flotillin-mediated endocytosis followed by lysosomal degradation or ALIX–syntenin-1–mediated exocytosis. Thus, cells undergoing necroptosis need to overcome these independent suppressive mechanisms before plasma membrane disruption can occur.

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KIF14 and citron kinase act together to promote efficient cytokinesis

The Journal of Cell Biology ◽

10.1083/jcb.200511061 ◽

2006 ◽

Vol 172 (3) ◽

pp. 363-372 ◽

Cited By ~ 179

Author(s):

Ulrike Gruneberg ◽

Rüdiger Neef ◽

Xiuling Li ◽

Eunice H.Y. Chan ◽

Ravindra B. Chalamalasetty ◽

...

Keyword(s):

Cell Division ◽

Human Cell ◽

Cleavage Furrow ◽

General Requirement ◽

Central Spindle ◽

Microtubule Associated Proteins ◽

Cell Biol ◽

Associated Proteins ◽

Essential Function ◽

Citron Kinase

Multiple mitotic kinesins and microtubule-associated proteins (MAPs) act in concert to direct cytokinesis (Glotzer, M. 2005. Science. 307:1735–1739). In anaphase cells, many of these proteins associate with an antiparallel array of microtubules termed the central spindle. The MAP and microtubule-bundling protein PRC1 (protein-regulating cytokinesis 1) is one of the key molecules required for the integrity of this structure (Jiang, W., G. Jimenez, N.J. Wells, T.J. Hope, G.M. Wahl, T. Hunter, and R. Fukunaga. 1998. Mol. Cell. 2:877–885; Mollinari, C., J.P. Kleman, W. Jiang, G. Schoehn, T. Hunter, and R.L. Margolis. 2002. J. Cell Biol. 157:1175–1186). In this study, we identify an interaction between endogenous PRC1 and the previously uncharacterized kinesin KIF14 as well as other mitotic kinesins (MKlp1/CHO1, MKlp2, and KIF4) with known functions in cytokinesis (Hill, E., M. Clarke, and F.A. Barr. 2000. EMBO J. 19:5711–5719; Matuliene, J., and R. Kuriyama. 2002. Mol. Biol. Cell. 13:1832–1845; Kurasawa, Y., W.C. Earnshaw, Y. Mochizuki, N. Dohmae, and K. Todokoro. 2004. EMBO J. 23:3237–3248). We find that KIF14 targets to the central spindle via its interaction with PRC1 and has an essential function in cytokinesis. In KIF14-depleted cells, citron kinase but not other components of the central spindle and cleavage furrow fail to localize. Furthermore, the localization of KIF14 and citron kinase to the central spindle and midbody is codependent, and they form a complex depending on the activation state of citron kinase. Contrary to a previous study (Di Cunto, F., S. Imarisio, E. Hirsch, V. Broccoli, A. Bulfone, A. Migheli, C. Atzori, E. Turco, R. Triolo, G.P. Dotto, et al. 2000. Neuron. 28:115–127), we find a general requirement for citron kinase in human cell division. Together, these findings identify a novel pathway required for efficient cytokinesis.

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