Sphingosine-1 phosphate prevents ethanol-induced corneal epithelial apoptosis

Background: Apoptosis is a programmed cell death in multicellular organisms, found in a wide variety of conditions, including inflammatory process, everywhere in the body, including the cornea and conjunctiva. Aim: To evaluate the effect of a new topical formulation of sphingosine-1 phosphate on preventing apoptosis of the corneal epithelium. Setting: Medical University. Materials and Methods: We tested several formulations suitable for topical application. Twenty-five rabbits were distributed among five groups. Group 1 comprised the controls. In Group 2, 20% ethanol was applied topically for 20 seconds; in Group 3, 50 μM topical sphingosine-1 phosphate was applied 2 hours prior to 20% ethanol application. In Group 4, 200 μM topical sphingosine-1 phosphate was applied 2 hours before the 20% ethanol application. In Group 5, only 200 μM topical sphingosine-1 phosphate was applied. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase biotin-dUTP Nick End Labeling (TUNEL) assay. Pairwise comparisons were performed using t-tests with Scheffe′s correction. Data were analyzed using STATA 9.0 statistical software. Results: A suspension of sphingosine-1 phosphate in the presence of Montanox 80 was stable and could be formulated without sonication. Epithelial apoptosis was detected only in Groups 2 and 3. Conclusion: Sphingosine-1 phosphate can prevent ethanol-induced apoptosis in the corneal epithelium of rabbits

Ceramide production associated with retinal apoptosis after retinal detachment.

International audienceBACKGROUND: During retinal detachment, premature apoptosis of photoreceptors and a loss of optimally corrected visual acuity occur. We hypothesized that retinal cell death and generation of ceramide, a pro-apoptotic lipid, would progress as a function of time following experimental retinal detachment, and undertook to define the appropriate temporal window. METHODS: Unilateral retinal detachment was induced in white New Zealand rabbits by subretinal injection of sodium hyaluronate. In experimental animals, we injected sphingosine-1-P into the vitreous 2 hours before retinal detachment. Both eyes were removed on days 1, 3 and 6 for histological and biochemical examination. The number of photoreceptors was counted in section, the level of apoptosis was assessed using the TUNEL assay, and the production of ceramide was analyzed in situ with immunohistochemistry. The concentration of ceramide was also determined on retinal homogenates using a diacylglycerol kinase assay. RESULTS: We confirmed that the average number of live photoreceptors decreased gradually after retinal detachment. In eyes pre-treated with sphingosine-1-P the number of apoptotic photoreceptors was significantly lower. The proportion of apoptotic photoreceptors (14%) remained constant as a function of time in the window studied. As compared to controls, the detached retina showed intense ceramide immunostaining that was prominent in the photoreceptors, but also present to a lesser extent in other retinal layers. The total concentration of intra-retinal ceramide increased by 40% on the first day and continued augmenting through the sixth day after retinal detachment. CONCLUSIONS: Retinal apoptosis during experimental retinal detachment is associated with in vivo production of ceramide

Theranostics of Primary Prostate Cancer: Beyond PSMA and GRP-R

The imaging of Prostate-Specific Membrane Antigen (PSMA) is now widely used at the initial staging of prostate cancers in patients with a high metastatic risk. However, its ability to detect low-grade tumor lesions is not optimal. Methods: First, we prospectively performed neurotensin receptor-1 (NTS1) IHC in a series of patients receiving both [68Ga]Ga-PSMA-617 and [68Ga]Ga-RM2 before prostatectomy. In this series, PSMA and GRP-R IHC were also available (n = 16). Next, we aimed at confirming the PSMA/GRP-R/NTS1 expression profile by retrospective autoradiography (n = 46) using a specific radiopharmaceuticals study and also aimed to decipher the expression of less-investigated targets such as NTS2, SST2 and CXCR4. Results: In the IHC study, all samples with negative PSMA staining (two patients with ISUP 2 and one with ISUP 3) were strongly positive for NTS1 staining. No samples were negative for all three stains—for PSMA, GRP-R or NTS1. In the autoradiography study, binding of [111In]In-PSMA-617 was high in all ISUP groups. However, some samples did not bind or bound weakly to [111In]In-PSMA-617 (9%). In these cases, binding of [111n]In-JMV 6659 and [111In]In-JMV 7488 towards NTS1 and NTS2 was high. Conclusions: Targeting PSMA and NTS1/NTS2 could allow for the detection of all intraprostatic lesions