Real-World Data on Intravitreal Aflibercept for Macular Edema Secondary to Central Retinal Vein Occlusion: 24-Month Outcomes.

Purpose: To report on the safety and effectiveness of intravitreal aflibercept (IVT-AFL) for macular edema secondary to central retinal vein occlusion (CRVO) in clinical practice in Japan. Patients and Methods: This prospective, noninterventional, multicenter post-authorization safety study enrolled patients who were treated with IVT-AFL for macular edema secondary to CRVO and followed up for 24 months. The primary outcome was the occurrence of safety events. Other pre-specified outcomes were indicators of effectiveness, including best corrected visual acuity (BCVA), central retinal thickness (CRT), and frequency of injections. Results: The safety analysis included 377 patients who received at least one IVT-AFL. Adverse events (AEs) occurred in 22 patients (5.84%) and adverse drug reactions occurred in 5 (1.33%) over 24 months. Of the 22 patients with AEs, 72.7% experienced their first AEs by the third injection. The effectiveness analysis set comprised 360 patients for whom data on each outcome could be collected. The number of injections over 24 months was 3.4 ± 2.4 (mean ± standard deviation [SD]). BCVA (logarithm of the minimum angle of resolution) was 0.709 ± 0.535 (mean ± SD) (n = 357) at baseline and 0.543 ± 0.559 (n = 97) after 24 months of treatment with IVT-AFL. CRT was 552.6 ± 211.3 µm (mean ± SD) (n = 214) at baseline and 331.5 ± 144.0 µm (n = 54) at 24 months. Conclusion: There were no new safety issues concerning routine administration of IVT-AFL for macular edema secondary to CRVO. BCVA recovered during 24 months of IVT-AFL treatment in the real-world setting. However, there was a trend toward less improvement compared with the results of randomized controlled trials, likely due in part to undertreatment.

Shigella targets epithelial tricellular junctions and uses a noncanonical clathrin-dependent endocytic pathway to spread between cells.

Bacteria move between cells in the epithelium using a sequential pseudopodium-mediated process but the underlying mechanisms remain unclear. We show that during cell-to-cell movement, Shigella-containing pseudopodia target epithelial tricellular junctions, the contact point where three epithelial cells meet. The bacteria-containing pseudopodia were engulfed by neighboring cells only in the presence of tricellulin, a protein essential for tricellular junction integrity. Shigella cell-to-cell spread, but not pseudopodium protrusion, also depended on phosphoinositide 3-kinase, clathrin, Epsin-1, and Dynamin-2, which localized beneath the plasma membrane of the engulfing cell. Depleting tricellulin, Epsin-1, clathrin, or Dynamin-2 expression reduced Shigella cell-to-cell spread, whereas AP-2, Dab2, and Eps15 were not critical for this process. Our findings highlight a mechanism for Shigella dissemination into neighboring cells via targeting of tricellular junctions and a noncanonical clathrin-dependent endocytic pathway.

A Tecpr1-dependent selective autophagy pathway targets bacterial pathogens.

Selective autophagy of bacterial pathogens represents a host innate immune mechanism. Selective autophagy has been characterized on the basis of distinct cargo receptors but the mechanisms by which different cargo receptors are targeted for autophagic degradation remain unclear. In this study we identified a highly conserved Tectonin domain-containing protein, Tecpr1, as an Atg5 binding partner that colocalized with Atg5 at Shigella-containing phagophores. Tecpr1 activity is necessary for efficient autophagic targeting of bacteria, but has no effect on rapamycin- or starvation-induced canonical autophagy. Tecpr1 interacts with WIPI-2, a yeast Atg18 homolog and PI(3)P-interacting protein required for phagophore formation, and they colocalize to phagophores. Although Tecpr1-deficient mice appear normal, Tecpr1-deficient MEFs were defective for selective autophagy and supported increased intracellular multiplication of Shigella. Further, depolarized mitochondria and misfolded protein aggregates accumulated in the Tecpr1-knockout MEFs. Thus, we identify a Tecpr1-dependent pathway as important in targeting bacterial pathogens for selective autophagy.

Listeria monocytogenes ActA-mediated escape from autophagic recognition.

Autophagy degrades unnecessary organelles and misfolded protein aggregates, as well as cytoplasm-invading bacteria. Nevertheless, the bacteria Listeria monocytogenes efficiently escapes autophagy. We show here that recruitment of the Arp2/3 complex and Ena/VASP, via the bacterial ActA protein, to the bacterial surface disguises the bacteria from autophagic recognition, an activity that is independent of the ability to mediate bacterial motility. L. monocytogenes expressing ActA mutants that lack the ability to recruit the host proteins initially underwent ubiquitylation, followed by recruitment of p62 (also known as SQSTM1) and LC3, before finally undergoing autophagy. The ability of ActA to mediate protection from ubiquitylation was further demonstrated by generating aggregate-prone GFP-ActA-Q79C and GFP-ActA-170(*) chimaeras, consisting of GFP (green fluorescent protein), the ActA protein and segments of polyQ or Golgi membrane protein GCP170 (ref. 6). GFP-ActA-Q79C and GFP-ActA-170(*) formed aggregates in the host cell cytoplasm, however, these ActA-containing aggregates were not targeted for association with ubiquitin and p62. Our findings indicate that ActA-mediated host protein recruitment is a unique bacterial disguise tactic to escape from autophagy.

Helicobacter pylori CagA phosphorylation-independent function in epithelial proliferation and inflammation.

CagA, a major virulence factor of Helicobacter pylori (Hp), is delivered into gastric epithelial cells and exists in phosphorylated and nonphosphorylated forms. The biological activity of the phosphorylated form is well established; however, function(s) of the nonphosphorylated form remain elusive. Here, we report that a conserved motif in the C-terminal region of CagA, which is distinct from the EPIYA motifs used for phosphorylation and which we designate CRPIA (conserved repeat responsible for phosphorylation-independent activity), plays pivotal roles in Hp pathogenesis. The CRPIA motif in nonphosphorylated CagA was involved in interacting with activated Met, the hepatocyte growth factor receptor, leading to the sustained activation of phosphatidylinositol 3-kinase/Akt signaling in response to Hp infection. This in turn led to the activation of beta-catenin and NF-kappaB signaling, which promote proliferation and inflammation, respectively. Thus, nonphosphorylated CagA activity contributes to the epithelial proliferative and proinflammatory responses associated with development of chronic gastritis and gastric cancer.

Hyphae formation of Candida albicans is regulated by polyamines.

Candida albicans generally grows in hyphae form in RPMI1640 medium. However, addition of 1,4-diamino-2-butanone (DAB), a competitive inhibitor of ornithine decarboxylase, decreased the amount of polyamines in C. albicans, and induced the proliferation of the C. albicans yeast form. The expression of CYR1 mRNA was significantly inhibited by the addition of DAB compared with that of the control. The amount of intracellular cAMP was also decreased by the addition of DAB. A specific adenylate cyclase inhibitor, cis-N-[2-phenylcyclopentyl]-azacyclotridec-1-en-2-amine (MDL-12,330A) promoted the growth of the yeast form. These results indicated that polyamines exist upstream of the adenylate cyclase-cAMP signal pathway and regulate the transformation of C. albicans.