Ataxia UK, Ataxia Ireland, Association Suisse de l'Ataxie de Friedreich, Associazione Italiana per le Sindromi Atassiche, UK National Institute for Health Research, European Friedreich's Ataxia Consortium for Translational Studies, and Imperial Biomedical Research Centre.

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Purpose: To report the front corneal versus central and paracentral corneal changes after Bowman layer transplantation for keratoconus in a tertiary hospital in the United Kingdom.Methods: Five eyes of 5 patients receiving Bowman layer transplant for advanced keratoconus in Royal Gwent Hospital (Newport, United Kingdom) were included. Preoperative and postoperative visual acuity; Kmax; Kmean, and corneal cylinder in the front cornea, 4.5 mm central, and 6 mm central; and corneal thickness were analyzed.Results: Corneal flattening and reduction in corneal astigmatism was observed, more marked in the central and paracentral zone, allowing for improvement in best-corrected visual acuity with the aid of visual correction in 4 eyes. Conclusions: These results support previous data reportingBowman layer transplantation as a useful strategy in the treatment of advanced keratoconus and suggest greater attention may be focused on central or paracentral corneal changes.

In vitro differentiation of human induced pluripotent stem cells (iPSCs) into beta cells represents an important cell source for diabetes research. Here, we fully characterized iPSC-derived beta cell function in vitro and in vivo in humanized mice. Using a 7-stage protocol, human iPSCs were differentiated into islet-like aggregates with a yield of insulin-positive beta cells comparable to that of human islets. The last three stages of differentiation were conducted with two different 3D culture systems, rotating suspension or static microwells. In the latter, homogeneously small-sized islet-like aggregates were obtained, while in rotating suspension size was heterogeneous and aggregates often clumped. In vitro function was assessed by glucose-stimulated insulin secretion, NAD(P)H and calcium fluctuations. Stage 7 aggregates slightly increased insulin release in response to glucose in vitro. Aggregates were transplanted under the kidney capsule of NOD-SCID mice to allow for further in vivo beta cell maturation. In transplanted mice, grafts showed glucose-responsiveness and maintained normoglycemia after streptozotocin injection. In situ kidney perfusion assays showed modulation of human insulin secretion in response to different secretagogues. In conclusion, iPSCs differentiated with equal efficiency into beta cells in microwells compared to rotating suspension, but the former had a higher experimental success rate. In vitro differentiation generated aggregates lacking fully mature beta cell function. In vivo, beta cells acquired the functional characteristics typical of human islets. With this technology an unlimited supply of islet-like organoids can be generated from human iPSCs that will be instrumental to study beta cell biology and dysfunction in diabetes.

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2576 Background: NUC-1031 is a novel nucleotide (ProTide) that evades all three key cellular resistance mechanisms associated with gemcitabine (dFdC). NUC-1031 bypasses nucleoside transporters, is activated independent of deoxycytidine kinase and is resistant to cytidine deaminase-mediated degradation. NUC-1031 has demonstrated broad antiproliferative activity in vitro and in vivo. Methods: Patients with relapsed/refractory advanced solid tumors entered in sequential cohorts of up to 6 patients, with escalating doses of NUC-1031 administered as a 5-10 minute IV injection weekly or twice-weekly. Ongoing objectives are to determine recommended phase II dose, safety profile, pharmacokinetics (PK) and preliminary anti-tumor activity. Results: 8 patients (5 female, 3 male) with pancreatic (2), colorectal (2), breast (1), and ovarian (1) cancers; cholangiocarcinoma (1) and unknown primary (1) have been enrolled. Two dose levels - 500mg/m2 (4) and 1000mg/m2 (1) weekly and one dose level - 375 mg/m2(3) twice-weekly. No DLTs have been observed. Mean AUC (0 - 24 h) for NUC-1031 was 150.3 ± 84.8 µM/h (n=5). dFdC and dFdU were detected in plasma up to 24 h (range of 0 - 5.8 µM for dFdC and 0 - 14.9 µM for dFdU). NUC-1031 excreted in urine mainly as dFdU. The Table shows rapid elimination of NUC-1031 from plasma and high intracellular levels of the active gemcitabine triphosphate at 2 and 24 h. Stable disease achieved in 1 patient with rapidly progressing breast cancer. Two further patients had symptomatic relief and improved QOL, including a dramatic reduction in ascites and pain. Conclusions: PK data show NUC-1031 has ≥ 10x higher intracellular levels of the active compound, dFdCTP, and significantly lower plasma Cmax levels of the toxic metabolite, dFdU, compared to equivalent levels of gemcitabine. NUC-1031 has shown better intracellular delivery and toxicity profile than gemcitabine with some promising early indicators of clinical efficacy. Clinical trial information: NCT01621854. [Table: see text]

The activation of G Protein-Coupled Receptor 56 (GPR56), also referred to as Adhesion G-Protein-Coupled Ceceptor G1 (ADGRG1), by Collagen Type III (Coll III) prompts cell growth, proliferation, and survival, among other attributes. We investigated the signaling cascades mediating this functional effect in relation to the mitochondrial outer membrane voltage-dependent anion Channel-1 (VDAC1) expression in pancreatic β-cells. GPR56KD attenuated the Coll III-induced suppression of P70S6K, JNK, AKT, NFκB, STAT3, and STAT5 phosphorylation/activity in INS-1 cells cultured at 20 mM glucose (glucotoxicity) for 72 h. GPR56-KD also increased Chrebp, Txnip, and Vdac1 while decreasing Vdac2 mRNA expression. In GPR56-KD islet β-cells, Vdac1 was co-localized with SNAP-25, demonstrating its plasma membrane translocation. This resulted in ATP loss, reduced cAMP production and impaired glucose-stimulated insulin secretion (GSIS) in INS-1 and human EndoC βH1 cells. The latter defects were reversed by an acute inhibition of VDAC1 with an antibody or the VDAC1 inhibitor VBIT-4. We demonstrate that Coll III potentiates GSIS by increasing cAMP and preserving β-cell functionality under glucotoxic conditions in a GPR56-dependent manner by attenuating the inflammatory response. These results emphasize GPR56 and VDAC1 as drug targets in conditions with impaired β-cell function.

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