Angiogenesis inhibition for the improvement of photodynamic therapy: The revival of a promising idea

Photodynamic therapy (PDT) is a minimally invasive form of treatment, which is clinically approved for the treatment of angiogenic disorders, including certain forms of cancer and neovascular eye diseases. Although the concept of PDT has existed for a long time now, it has never made a solid entrance into the clinical management of cancer. This is likely due to secondary tissue reactions, such as inflammation and neoangiogenesis. The recent development of clinically effective angiogenesis inhibitors has lead to the initiation of research on the combination of PDT with such angiostatic targeted therapies. Preclinical studies in this research field have shown promising results, causing a revival in the field of PDT. This review reports on the current research efforts on PDT and vascular targeted combination therapies. Different combination strategies with angiogenesis inhibition and vascular targeting approaches are discussed. In addition, the concept of increasing PDT selectivity by targeted delivery of photosensitizers is presented. Furthermore, the current insights on sequencing the therapy arms of such combinations will be discussed in light of vascular normalization induced by angiogenesis inhibition.     

Abi1/Hssh3bp1 pY213 links Abl kinase signaling to p85 regulatory subunit of PI-3 kinase in regulation of macropinocytosis in LNCaP cells

Macropinocytosis is regulated by Abl kinase via an unknown mechanism. We previously demonstrated that Abl kinase activity is, itself, regulated by Abi1 subsequent to Abl kinase phosphorylation of Abi1 tyrosine 213 (pY213) [1]. Here we show that blocking phosphorylation of Y213 abrogated the ability of Abl to regulate macropinocytosis, implicating Abi1 pY213 as a key regulator of macropinocytosis. Results from screening the human SH2 domain library and mapping the interaction site between Abi1 and the p85 regulatory domain of PI-3 kinase, coupled with data from cells transfected with loss-of-function p85 mutants, support the hypothesis that macropinocytosis is regulated by interactions between Abi1 pY213 and the C-terminal SH2 domain of p85—thereby linking Abl kinase signaling to p85-dependent regulation of macropinocytosis.

Structured summary

MINT-7908602: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to SHIP2 (uniprotkb:O15357) by array technology (MI:0008)MINT-7908362: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Emt (uniprotkb:Q08881) by array technology (MI:0008)MINT-7908235: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Lyn (uniprotkb:P07948) by array technology (MI:0008)MINT-7908075: Abi1 (uniprotkb:Q8IZP0)binds (MI:0407) to Fgr (uniprotkb:P09769) by array technology (MI:0008)MINT-7908330, MINT-7908522: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Vav1 (uniprotkb:P15498) by array technology (MI:0008)MINT-7907962: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Fyn (uniprotkb:P06241) by array technology (MI:0008)MINT-7908203: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Src (uniprotkb:P12931) by array technology (MI:0008)MINT-7908570: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to SHP-2 (uniprotkb:P35235) by array technology (MI:0008)MINT-7908187, MINT-7908586: Abi1(uniprotkb:Q8IZP0) binds (MI:0407) to Gap (uniprotkb:P20936) by array technology (MI:0008)MINT-7907981, MINT-7907995: Abi1 (uniprotkb:Q8IZP0) physically interacts (MI:0915) with p85a (uniprotkb:P26450) by anti tag coimmunoprecipitation (MI:0007)MINT-7908251: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to PLCG1 (uniprotkb:P19174) by array technology (MI:0008)MINT-7908346: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Grb2 (uniprotkb:P62993) by array technology (MI:0008)MINT-7907945: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Abl (uniprotkb:P00519) by array technology (MI:0008)MINT-7908474: Abi1 (uniprotkb:Q8IZP0)binds (MI:0407) to p85b (uniprotkb:O00459) by array technology (MI:0008)MINT-7908107: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Hck (uniprotkb:P08631) by array technology (MI:0008)MINT-7908011: p85a (uniprotkb:P26450) physically interacts (MI:0915) with Abi1 (uniprotkb:Q8IZP0) by pull down (MI:0096)MINT-7908155: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to FynT (uniprotkb:P06241-2) by array technology (MI:0008)MINT-7908283, MINT-7908490: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to p55g (uniprotkb:Q92569) by array technology (MI:0008)MINT-7907929, MINT-7907815, MINT-7907832, MINT-7907865, MINT-7907897, MINT-7907913, MINT-7907881, MINT-7907848: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to p85a (uniprotkb:P27986) by array technology (MI:0008)MINT-7908059: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Frk (uniprotkb:P42685) by array technology (MI:0008)MINT-7908378: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to CblC (uniprotkb:Q9ULV8) by array technology (MI:0008)MINT-7908618: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to CblA (uniprotkb:B5MC15) by array technology (MI:0008)MINT-7908139, MINT-7908538: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Nap4 (uniprotkb:O14512) by array technology (MI:0008)MINT-7908426: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to CblB (uniprotkb:Q13191) by array technology (MI:0008)MINT-7908506: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Crk (uniprotkb:P46108) by array technology (MI:0008)MINT-7908554: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to mAbl (uniprotkb:P00520) by array technology (MI:0008)MINT-7908043, MINT-7908394: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Vav2 (uniprotkb:P52735) by array technology (MI:0008)MINT-7908458: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to mSck/ShcB (uniprotkb:Q8BMC3) by array technology (MI:0008)MINT-7908091: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Yes (uniprotkb:P07947) by array technology (MI:0008)MINT-7908219: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Src (uniprotkb:P00523) by array technology (MI:0008)MINT-7908123: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Fer (uniprotkb:P16591) by array technology (MI:0008)MINT-7908410: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to CrkL (uniprotkb:P46109) by array technology (MI:0008)MINT-7908314, MINT-7908442: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Arg (uniprotkb:P42684) by array technology (MI:0008)MINT-7908299: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to PLCG1 (uniprotkb:P10686) by array technology (MI:0008)MINT-7908171: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Fes (uniprotkb:P07332) by array technology (MI:0008)MINT-7908027: Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Lck (uniprotkb:P06239) by array technology (MI:0008)     

Aggregation of spectrin and PKCθ is an early hallmark of fludarabine/mitoxantrone/dexamethasone-induced apoptosis in Jurkat T and HL60 cells

It has been shown that changes in spectrin distribution in early apoptosis preceded changes in membrane asymmetry and phosphatidylserine (PS) exposure. PKCθ was associated with spectrin during these changes, suggesting a possible role of spectrin/PKCθ aggregation in regulation of early apoptotic events. Here we dissect this hypothesis using Jurkat T and HL60 cell lines as model systems. Immunofluorescent analysis of αIIβII spectrin arrangement in Jurkat T and HL60 cell lines revealed the redistribution of spectrin and PKCθ into a polar aggregate in early apoptosis induced by fludarabine/mitoxantrone/dexamethasone (FND). The appearance of an αIIβII spectrin fraction that was insoluble in a non-ionic detergent (1% Triton X-100) was observed concomitantly with spectrin aggregation. The changes were observed within 2 h after cell exposure to FND, and preceded PS exposure. The changes seem to be restricted to spectrin and not to other cytoskeletal proteins such as actin or vimentin. In studies of the mechanism of these changes, we found that (i) neither changes in apoptosis regulatory genes (e.g., Bcl-2 family proteins) nor changes in cytoskeleton-associated proteins were detected in gene expression profiling of HL60 cells after the first hour of FND treatment, (ii) caspase-3, -7, -8, and -10 had minor involvement in the early apoptotic rearrangement of spectrin/PKCθ, and (iii) spectrin aggregation was shown to be partially dependent on PKCθ activity. Our results indicate that spectrin/PKCθ aggregate formation is related to an early stage in drug-induced apoptosis and possibly may be regulated by PKCθ activity. These findings indicate that spectrin/PKCθ aggregation could be considered as a hallmark of early apoptosis and presents the potential to become a useful diagnostic tool for monitoring efficiency of chemotherapy as early as 24 h after treatment.     

Lipid phosphatase SHIP-1 regulates chondrocyte hypertrophy and skeletal development

SH2-containing inositol-5′-phosphatase-1 (SHIP-1) controls the phosphatidylinositol-3′-kinase (PI3K) initiated signaling pathway by limiting cell membrane recruitment and activation of Akt. Despite the fact that many of the growth factors important to cartilage development and functions are able to activate the PI3K signal transduction pathway, little is known about the role of PI3K signaling in chondrocyte biology and its contribution to mammalian skeletogenesis. Here, we report that the lipid phosphatase SHIP-1 regulates chondrocyte hypertrophy and skeletal development through its expression in osteochondroprogenitor cells. Global SHIP-1 knockout led to accelerated chondrocyte hypertrophy and premature formation of the secondary ossification center in the bones of postnatal mice. Drastically higher vascularization and greater number of c-kit + progenitors associated with sinusoids in the bone marrow also indicated more advanced chondrocyte hypertrophic differentiation in SHIP-1 knockout mice than in wild-type mice. In corroboration with the in vivo phenotype, SHIP-1 deficient PDGFRα + Sca-1 + osteochondroprogenitor cells exhibited rapid differentiation into hypertrophic chondrocytes under chondrogenic culture conditions in vitro. Furthermore, SHIP-1 deficiency inhibited hypoxia-induced cellular activation of Akt and extracellular-signal-regulated kinase (Erk) and suppressed hypoxia-induced cell proliferation. These results suggest that SHIP-1 is required for hypoxia-induced growth signaling under physiological hypoxia in the bone marrow. In conclusion, the lipid phosphatase SHIP-1 regulates skeletal development by modulating chondrogenesis and the hypoxia response of the osteochondroprogenitors during endochondral bone formation.     

Thrombopoietin-Increased DNA-PK-Dependent DNA Repair Limits Hematopoietic Stem and Progenitor Cell Mutagenesis in Response to DNA Damage

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Highlights? Mpl loss increases γ-irradiation-induced genomic instability in HSPCs ? TPO promotes DNA repair in vitro and in vivo in HSPCs ? TPO increases DNA-PK activity and NHEJ-mediated repair efficiency in HSPCs ? A single TPO injection before mouse TBI limits long-term HSC injury and mutagenesis     

Cloning and functional analysis of the dpm2 and dpm3 genes from Trichoderma reesei expressed in a Saccharomyces cerevisiae dpm1Δ mutant strain

In Trichoderma reesei, dolichyl phosphate mannose (dpm) synthase, a key enzyme in the O-glycosylation process, requires three proteins for full activity. In this study, the dpm2 and dpm3 genes coding for the DPMII and DPMIII subunits of T. reesei DPM synthase were cloned and functionally analyzed after expression in the Saccharomyces cerevisiae dpm1Δ [genotype (BY4743; his3Δ1; /leu2Δ0; lys2Δ0; /ura3Δ0; YPR183w::kanMX4] mutant. It was found that apart from the catalytic subunit DPMI, the DPMIII subunit is also essential to form an active DPM synthase in yeast. Additional expression of the DPMII protein, considered to be a regulatory subunit of DPM synthase, decreased the enzymatic activity. We also characterized S. cerevisiae strains expressing the dpm1, 2, 3 or dpm1, 3 genes and analyzed the consequences of dpm expression on protein O-glycosylation in vivo and on the cell wall composition.     

Light-induced responses of slow oscillatory neurons of the rat olivary pretectal nucleus

Background

The olivary pretectal nucleus (OPN) is a small midbrain structure responsible for pupil constriction in response to eye illumination. Previous electrophysiological studies have shown that OPN neurons code light intensity levels and therefore are called luminance detectors. Recently, we described an additional population of OPN neurons, characterized by a slow rhythmic pattern of action potentials in light-on conditions. Rhythmic patterns generated by these cells last for a period of approximately 2 minutes.

Methodology

To answer whether oscillatory OPN cells are light responsive and whether oscillatory activity depends on retinal afferents, we performed in vivo electrophysiology experiments on urethane anaesthetized Wistar rats. Extracellular recordings were combined with changes in light conditions (light-dark-light transitions), brief light stimulations of the contralateral eye (diverse illuminances) or intraocular injections of tetrodotoxin (TTX).

Conclusions

We found that oscillatory neurons were able to fire rhythmically in darkness and were responsive to eye illumination in a manner resembling that of luminance detectors. Their firing rate increased together with the strength of the light stimulation. In addition, during the train of light pulses, we observed two profiles of responses: oscillation-preserving and oscillation-disrupting, which occurred during low- and high-illuminance stimuli presentation respectively. Moreover, we have shown that contralateral retina inactivation eliminated oscillation and significantly reduced the firing rate of oscillatory cells. These results suggest that contralateral retinal innervation is crucial for the generation of an oscillatory pattern in addition to its role in driving responses to visual stimuli.     

Release of Metal Ions from Orthodontic Appliances: An In Vitro Study

In this paper, we report the results of an in vitro experiment on the release of metal ions from orthodontic appliances composed of alloys containing iron, chromium, nickel, silicon, and molybdenum into artificial saliva. The concentrations of magnesium, aluminum, silicon, phosphorus, sulfur, potassium, calcium, titanium, vanadium, manganese, iron, cobalt, copper, zinc, nickel, and chromium were significantly higher in artificial saliva in which metal brackets, bands, and wires used in orthodontics were incubated. In relation to the maximum acceptable concentrations of metal ions in drinking water and to recommended daily doses, two elements of concern were nickel (573 vs. 15 μg/l in the controls) and chromium (101 vs. 8 μg/l in the controls). Three ion release coefficients were defined: α, a dimensionless multiplication factor; β, the difference in concentrations (in micrograms per liter); and γ, the ion release coefficient (in percent). The elevated levels of metals in saliva are thought to occur by corrosion of the chemical elements in the alloys or welding materials. The concentrations of some groups of dissolved elements appear to be interrelated.     

Alterations in protein secretion caused by metabolic engineering of glycosylation pathways in fungi

Due to its natural properties, Trichoderma reesei is commonly used in industry-scale production of secretory proteins. Since almost all secreted proteins are O-glycosylated, modulation of the activity of enzymes of the O-glycosylation pathway are likely to affect protein production and secretion or change the glycosylation pattern of the secreted proteins, altering their stability and biological activity. Understanding how the activation of different components of the O-glycosylation pathway influences the glycosylation pattern of proteins and their production and secretion could help in elucidating the mechanism of the regulation of these processes and should facilitate creation of engineered microorganisms producing high amounts of useful proteins. In this review we focus on data concerning Trichoderma, but also present some background information allowing comparison with other fungal species.