Glucocorticoids exert direct toxicity on microvasculature: analysis of cell death mechanisms.

Glucocorticoids (GCs) are routinely administered systemically or injected into the eye when treating numerous ocular diseases; however, their toxicity on the retinal microvasculature has not been previously investigated. In this article, the effects of hydrocortisone (Hydro), dexamethasone, dexamethasone-phosphate and triamcinolone acetonide (TA) were evaluated in vitro on human skin microcirculation cells and, bovine endothelial retinal cells, ex-vivo, on flat mounted rat retinas. The degree of GCs induced endothelial cell death varied according to the endothelial cell type and GCs chemical properties. GCs toxicity was higher in skin microvascular endothelial cells and for hydrophobic GC formulations. The mechanism of cell death differed between GCs, Hydro and TA activated the leukocyte elastase inhibitor/L-DNase II pathways but did not activate caspases. The mechanisms of cell death observed in cell cultures were similar to those observed in rat retinal explants. Taken together these results indicate that particular attention should be paid to the potential vascular side effects when administrating GCs clinically and in particular when developing sustained-release intraocular devices

Subconjunctival Injection of XG-102, a c-Jun N-Terminal Kinase Inhibitor Peptide, in the Treatment of Endotoxin-Induced Uveitis in Rats.

Abstract Purpose: XG-102, a TAT-coupled dextrogyre peptide inhibiting the c-Jun N-terminal kinase, was shown efficient in the treatment of experimental uveitis. Preclinical studies are now performed to determine optimal XG-102 dose and route of administration in endotoxin-induced uveitis (EIU) in rats with the purpose of clinical study design. METHODS: EIU was induced in Lewis rats by lipopolysaccharides (LPS) injection. XG-102 was administered at the time of LPS challenge by intravenous (IV; 3.2, 35 or 355 μg/injection), intravitreal (IVT; 0.08, 0.2 or 2.2 μg/eye), or subconjunctival (SCJ; 0.2, 1.8 or 22 μg/eye) routes. Controls received either the vehicle (saline) or dexamethasone phosphate injections. Efficacy was assessed by clinical scoring, infiltrating cells count, and expression of inflammatory mediators [inducible nitric oxide synthase (iNOS), cytokine-induced neutrophil chemoattractant-1 (CINC-1)]. The effect of XG-102 on phosphorylation of c-Jun was evaluated by Western blot. RESULTS: XG-102 demonstrated a dose-dependent anti-inflammatory effect in EIU after IV and SCJ administrations. Respective doses of 35 and 1.8 μg were efficient as compared with the vehicle-injected controls, but only the highest doses, respectively 355 and 22 μg, were as efficient as dexamethasone phosphate. After IVT injections, the anti-inflammatory effect of XG-102 was clinically evaluated similar to the corticoid's effect with all the tested doses. Regardless of the administration route, the lowest efficient doses of XG-102 significantly decreased the ration of phospho c-Jun/total c-Jun, reduced cells infiltration in the treated eyes, and significantly downregulated iNOS and CINC-1 expression in the retina. CONCLUSION: These results confirm that XG-102 peptide has potential for treating intraocular inflammation. SCJ injection appears as a good compromise to provide a therapeutic effect while limiting side effects

Genomic and transcriptomic landscape of conjunctival melanoma.

Conjunctival melanoma (CJM) is a rare but potentially lethal and highly-recurrent cancer of the eye. Similar to cutaneous melanoma (CM), it originates from melanocytes. Unlike CM, however, CJM is relatively poorly characterized from a genomic point of view. To fill this knowledge gap and gain insight into the genomic nature of CJM, we performed whole-exome (WES) or whole-genome sequencing (WGS) of tumor-normal tissue pairs in 14 affected individuals, as well as RNA sequencing in a subset of 11 tumor tissues. Our results show that, similarly to CM, CJM is also characterized by a very high mutation load, composed of approximately 500 somatic mutations in exonic regions. This, as well as the presence of a UV light-induced mutational signature, are clear signs of the role of sunlight in CJM tumorigenesis. In addition, the genomic classification of CM proposed by TCGA seems to be well-applicable to CJM, with the presence of four typical subclasses defined on the basis of the most frequently mutated genes: BRAF, NF1, RAS, and triple wild-type. In line with these results, transcriptomic analyses revealed similarities with CM as well, namely the presence of a transcriptomic subtype enriched for immune genes and a subtype enriched for genes associated with keratins and epithelial functions. Finally, in seven tumors we detected somatic mutations in ACSS3, a possible new candidate oncogene. Transfected conjunctival melanoma cells overexpressing mutant ACSS3 showed higher proliferative activity, supporting the direct involvement of this gene in the tumorigenesis of CJM. Altogether, our results provide the first unbiased and complete genomic and transcriptomic classification of CJM

Comprehensive Genetic Landscape of Uveal Melanoma by Whole-Genome Sequencing.

Uveal melanoma (UM) is a rare intraocular tumor that, similar to cutaneous melanoma, originates from melanocytes. To gain insights into its genetics, we performed whole-genome sequencing at very deep coverage of tumor-control pairs in 33 samples (24 primary and 9 metastases). Genome-wide, the number of coding mutations was rather low (only 17 variants per tumor on average; range 7-28), thus radically different from cutaneous melanoma, where hundreds of exonic DNA insults are usually detected. Furthermore, no UV light-induced mutational signature was identified. Recurrent coding mutations were found in the known UM drivers GNAQ, GNA11, BAP1, EIF1AX, and SF3B1. Other genes, i.e., TP53BP1, CSMD1, TTC28, DLK2, and KTN1, were also found to harbor somatic mutations in more than one individual, possibly indicating a previously undescribed association with UM pathogenesis. De novo assembly of unmatched reads from non-coding DNA revealed peculiar copy-number variations defining specific UM subtypes, which in turn could be associated with metastatic transformation. Mutational-driven comparison with other tumor types showed that UM is very similar to pediatric tumors, characterized by very few somatic insults and, possibly, important epigenetic changes. Through the analysis of whole-genome sequencing data, our findings shed new light on the molecular genetics of uveal melanoma, delineating it as an atypical tumor of the adult for which somatic events other than mutations in exonic DNA shape its genetic landscape and define its metastatic potential

Mutations in CEP78 Cause Cone-Rod Dystrophy and Hearing Loss Associated with Primary-Cilia Defects.

Cone-rod degeneration (CRD) belongs to the disease spectrum of retinal degenerations, a group of hereditary disorders characterized by an extreme clinical and genetic heterogeneity. It mainly differentiates from other retinal dystrophies, and in particular from the more frequent disease retinitis pigmentosa, because cone photoreceptors degenerate at a higher rate than rod photoreceptors, causing severe deficiency of central vision. After exome analysis of a cohort of individuals with CRD, we identified biallelic mutations in the orphan gene CEP78 in three subjects from two families: one from Greece and another from Sweden. The Greek subject, from the island of Crete, was homozygous for the c.499+1G>T (IVS3+1G>T) mutation in intron 3. The Swedish subjects, two siblings, were compound heterozygotes for the nearby mutation c.499+5G>A (IVS3+5G>A) and for the frameshift-causing variant c.633delC (p.Trp212Glyfs(∗)18). In addition to CRD, these three individuals had hearing loss or hearing deficit. Immunostaining highlighted the presence of CEP78 in the inner segments of retinal photoreceptors, predominantly of cones, and at the base of the primary cilium of fibroblasts. Interaction studies also showed that CEP78 binds to FAM161A, another ciliary protein associated with retinal degeneration. Finally, analysis of skin fibroblasts derived from affected individuals revealed abnormal ciliary morphology, as compared to that of control cells. Altogether, our data strongly suggest that mutations in CEP78 cause a previously undescribed clinical entity of a ciliary nature characterized by blindness and deafness but clearly distinct from Usher syndrome, a condition for which visual impairment is due to retinitis pigmentosa

Conjunctival Melanoma Targeted Therapy: MAPK and PI3K/mTOR Pathways Inhibition.

To analyze the activity of mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinases/mechanistic target of rapamycin (PI3K/mTOR) pathways in benign and malignant conjunctival melanocytic proliferations and explore whether specific inhibitors can suppress growth of conjunctival melanoma (CJM) cells. The presence of a BRAF V600E mutation and activation of ERK, MEK, S6, and AKT were assessed with immunohistochemistry in 35 conjunctival nevi and 31 melanomas. Three CJM cell lines were used: CRMM1, carrying the BRAF V600E mutation; CRMM2, harboring the NRAS Q61L mutation; and T1527A, with a BRAF G466E mutation. WST-1 assays were performed with a BRAF inhibitor (vemurafenib), two MEK inhibitors (trametinib, selumetinib), a PI3K inhibitor (pictilisib), and a dual PI3K/mTOR inhibitor (dactolisib). The phosphorylation of ERK, MEK, and S6 were tested with western blots and apoptosis with cleaved caspase-3 immunostaining. A BRAF V600E mutation was detected in 42.6% of nevi and in 35.5% of CJM. MEK and ERK activation were higher in CJM, occurring in 62.9% and 45.7% of the nevi and 90.3% and 96.8% of the CJM, respectively. There was also a significant increase in S6 activation in CJM (90.3%) compared with the nevi (20%). CRMM1 was sensitive to trametinib and the PI3K inhibitors but only marginally to vemurafenib. CRMM2 was moderately sensitive to pictilisib, whereas T1527A was resistant to all drugs tested. The MAPK pathway activity in CJM is increased, not only as a consequence of the BRAF V600E mutation. Targeted therapy may be useful for patients with CJM, especially those with activating BRAF mutations, whereas NRAS-mutated melanomas are relatively resistant

Effect of SGLT2 inhibitors on stroke and atrial fibrillation in diabetic kidney disease: Results from the CREDENCE trial and meta-analysis

BACKGROUND AND PURPOSE: Chronic kidney disease with reduced estimated glomerular filtration rate or elevated albuminuria increases risk for ischemic and hemorrhagic stroke. This study assessed the effects of sodium glucose cotransporter 2 inhibitors (SGLT2i) on stroke and atrial fibrillation/flutter (AF/AFL) from CREDENCE (Canagliflozin and Renal Events in Diabetes With Established Nephropathy Clinical Evaluation) and a meta-Analysis of large cardiovascular outcome trials (CVOTs) of SGLT2i in type 2 diabetes mellitus. METHODS: CREDENCE randomized 4401 participants with type 2 diabetes mellitus and chronic kidney disease to canagliflozin or placebo. Post hoc, we estimated effects on fatal or nonfatal stroke, stroke subtypes, and intermediate markers of stroke risk including AF/AFL. Stroke and AF/AFL data from 3 other completed large CVOTs and CREDENCE were pooled using random-effects meta-Analysis. RESULTS: In CREDENCE, 142 participants experienced a stroke during follow-up (10.9/1000 patient-years with canagliflozin, 14.2/1000 patient-years with placebo; hazard ratio [HR], 0.77 [95% CI, 0.55-1.08]). Effects by stroke subtypes were: ischemic (HR, 0.88 [95% CI, 0.61-1.28]; n=111), hemorrhagic (HR, 0.50 [95% CI, 0.19-1.32]; n=18), and undetermined (HR, 0.54 [95% CI, 0.20-1.46]; n=17). There was no clear effect on AF/AFL (HR, 0.76 [95% CI, 0.53-1.10]; n=115). The overall effects in the 4 CVOTs combined were: Total stroke (HRpooled, 0.96 [95% CI, 0.82-1.12]), ischemic stroke (HRpooled, 1.01 [95% CI, 0.89-1.14]), hemorrhagic stroke (HRpooled, 0.50 [95% CI, 0.30-0.83]), undetermined stroke (HRpooled, 0.86 [95% CI, 0.49-1.51]), and AF/AFL (HRpooled, 0.81 [95% CI, 0.71-0.93]). There was evidence that SGLT2i effects on total stroke varied by baseline estimated glomerular filtration rate (P=0.01), with protection in the lowest estimated glomerular filtration rate (45 mL/min/1.73 m2]) subgroup (HRpooled, 0.50 [95% CI, 0.31-0.79]). CONCLUSIONS: Although we found no clear effect of SGLT2i on total stroke in CREDENCE or across trials combined, there was some evidence of benefit in preventing hemorrhagic stroke and AF/AFL, as well as total stroke for those with lowest estimated glomerular filtration rate. Future research should focus on confirming these data and exploring potential mechanisms

Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to 300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m 2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years