Sensitization of stefin B‐deficient thymocytes towards staurosporin‐induced apoptosis is independent of cysteine cathepsins

Kopitar-Jerala, Nataša; Schweiger, Ana; Myers, R; Türk, Vito; Turk, Boris

doi:10.1016/j.febslet.2005.03.002

Cited by 28 publications

(31 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A431 cells were infected with wt MS11 or MS11pilT or mock infected. Parallel uninfected cultures were treated with STS as a positive control for apoptosis (5,22). The cells were stained with YO-PRO-1 and PI and analyzed by flow cytometry (18).…”

Section: Resultsmentioning

confidence: 99%

Dynamics of Neisseria gonorrhoeae Attachment: Microcolony Development, Cortical Plaque Formation, and Cytoprotection

Higashi¹,

Lee²,

et al. 2007

View full text Add to dashboard Cite

Neisseria gonorrhoeae is the bacterium that causes gonorrhea, a major sexually transmitted disease and a significant cofactor for human immunodeficiency virus transmission. The retactile N. gonorrhoeae type IV pilus (Tfp) mediates twitching motility and attachment. Using live-cell microscopy, we reveal for the first time the dynamics of twitching motility by N. gonorrhoeae in its natural environment, human epithelial cells. Bacteria aggregate into microcolonies on the cell surface and induce a massive remodeling of the microvillus architecture. Surprisingly, the microcolonies are motile, and they fuse to form progressively larger structures that undergo rapid reorganization, suggesting that bacteria communicate with each other during infection. As reported, actin plaques form beneath microcolonies. Here, we show that cortical plaques comigrate with motile microcolonies. These activities are dependent on pilT, the Tfp retraction locus. Cultures infected with a pilT mutant have significantly higher numbers of apoptotic cells than cultures infected with the wild-type strain. Inducing pilT expression with isopropyl-␤-D-thiogalactopyranoside partially rescues cells from infection-induced apoptosis, demonstrating that Tfp retraction is intrinsically cytoprotective for the host. Tfp-mediated attachment is therefore a continuum of microcolony motility and force stimulation of host cell signaling, leading to a cytoprotective effect.Type IV pili (Tfp) are filamentous appendages expressed by a wide range of bacteria, including Synechocystis spp., Pseudomonas aeruginosa, Myxococcus xanthus, Xylella fastidiosa, Clostridium perfringens, enterohaemorrhagic and enteropathogenic Escherichia coli, Neisseria meningitidis, and Neisseria gonorrhoeae (29,32,37,50,54,56,61). The Tfp of several of these bacteria are known to retract, and retraction underlies twitching motility, DNA uptake, phage sensitivity, and social behavior, such as fruiting-body and biofilm formation.N. gonorrhoeae, the bacterium that causes gonorrhea, expresses multiple nonpolar retractile Tfp that promote attachment to epithelial cells (38). Retraction requires the ATPase PilT, which is proposed to disassemble the Tfp fiber (2,13,15). N. gonorrhoeae pilT null mutants express nonretractile Tfp (38,60). Cycles of Tfp extension, substrate tethering, and retraction enable N. gonorrhoeae to crawl on a glass coverslip or agar surface (twitching motility) (34). Twitching motility on epithelial cells has not been studied. Understanding N. gonorrhoeae motility behavior in this environment is important, as the bacterium infects only humans and cannot survive outside the human body.Mechanical forces of 50 to 100 pN are generated by the retraction of a Tfp fiber (24, 38). Thus, Tfp retraction allows N. gonorrhoeae to pull and exert physical stress on its substrate. Tfp retraction induces a number of responses in the infected epithelial cell. It triggers Ca 2ϩ and stress kinase signaling, cytoskeletal rearrangements, and cortical plaque formation and regulates epithelial gen...

show abstract

Section: Resultsmentioning

confidence: 99%

Dynamics of Neisseria gonorrhoeae Attachment: Microcolony Development, Cortical Plaque Formation, and Cytoprotection

Higashi¹,

Lee²,

et al. 2007

View full text Add to dashboard Cite

show abstract

“…The protein concentration of the cell lysates was measured using the Bradford reagent (Bio-Rad). The lysates were subjected to electrophoresis on 12.5% SDS-polyacrylamide gels followed by Western blotting as described previously (33). The proteins were visualized with ECL (Amersham Biosciences) according to the manufacturer's instructions.…”

Section: Cell Lysate Preparation and Western Blot Analysismentioning

confidence: 99%

“…Monolayer BMDMs at 80% confluence were first washed with ice-cold PBS, followed by the direct addition of the radioimmune precipitation assay lysis buffer supplemented with the Complete protease inhibitor mixture (Sigma) Cell lysates were prepared as described previously (33). The protein concentration of the cell lysates was measured using the Bradford reagent (Bio-Rad).…”

Section: Cell Lysate Preparation and Western Blot Analysismentioning

confidence: 99%

A Role for Stefin B (Cystatin B) in Inflammation and Endotoxemia

Maher

Kokelj

Butinar

et al. 2014

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Background:The lack of cysteine cathepsin inhibitor, stefin B (cystatin B), results in progressive myoclonus epilepsy, type 1. Results: Stefin B deficiency in macrophages resulted in increased inflammasome activation. Conclusion: Stefin B-deficient mice are significantly more sensitive to e LPS-induced sepsis due to increased caspase-11 expression and mitochondrial damage. Significance: Stefin B has an important role in limiting the inflammatory response during LPS-induced sepsis.

show abstract

“…The lysates were then clarified by centrifugation at 13 000Âg for 10 min at 4°C, and the protein concentrations of the cell lysates were measured using the Bradford reagent (BioRad). The lysates were subjected to electrophoresis on 12.5% SDS-PAGE gels followed by Western blotting as described previously [8]. The proteins were visualized with ECL (GE Healthcare) according to the manufacturer's instructions.…”

Section: Whole Cell Lysates Preparation and Western Blot Analysismentioning

confidence: 99%

“…Studies of stefin B-deficient mice show that lack of this inhibitor is associated with the signs of cerebellar granular cell apoptosis, progressive ataxia and myoclonic seizures [6]. It was demonstrated that stefin B deficiency sensitizes the cells to the oxidative stress-induced cell death [7,8]. In the past, several studies examined the influence of cystatins on nitric oxide (NO) and cytokine synthesis, predominantly type II cystatins induce NO secretion in IFN-c-primed mouse macrophages [9,10].…”

Section: Introductionmentioning

confidence: 99%

Decreased IL‐10 expression in stefin B‐deficient macrophages is regulated by the MAP kinase and STAT‐3 signaling pathways

et al. 2014

Self Cite

View full text Add to dashboard Cite

a b s t r a c tInnate immune responses are tightly regulated to avoid excessive activation and subsequent inflammatory damage to the host, and interleukin-10 (IL-10) plays a crucial role in preventing inflammation. Stefin B (cystatin B) is an endogenous inhibitor of cysteine proteinases. In stefin B-deficient bone marrow-derived macrophages (BMDMs), we detected an increase in the induction of the LPS-induced pro-inflammatory signal nitric oxide (NO) but decreased IL-10 expression. The phosphorylation of ERK and p38 MAP-kinases was significantly decreased in stefin B-deficient macrophages, as was STAT-3 phosphorylation. These findings show that stefin B influences the expression of anti-inflammatory IL-10 in response to the TLR4 agonist LPS.

show abstract

Sensitization of stefin B‐deficient thymocytes towards staurosporin‐induced apoptosis is independent of cysteine cathepsins

Cited by 28 publications

References 37 publications

Dynamics of Neisseria gonorrhoeae Attachment: Microcolony Development, Cortical Plaque Formation, and Cytoprotection

Dynamics of Neisseria gonorrhoeae Attachment: Microcolony Development, Cortical Plaque Formation, and Cytoprotection

A Role for Stefin B (Cystatin B) in Inflammation and Endotoxemia

Decreased IL‐10 expression in stefin B‐deficient macrophages is regulated by the MAP kinase and STAT‐3 signaling pathways

Contact Info

Product

Resources

About