Inefficient SRP interaction with a nascent chain triggers a mRNA quality control pathway.

Misfolded proteins are often cytotoxic, unless cellular systems prevent their accumulation. Data presented here uncover a mechanism by which defects in secretory proteins lead to a dramatic reduction in their mRNAs and protein expression. When mutant signal sequences fail to bind to the signal recognition particle (SRP) at the ribosome exit site, the nascent chain instead contacts Argonaute2 (Ago2), and the mutant mRNAs are specifically degraded. Severity of signal sequence mutations correlated with increased proximity of Ago2 to nascent chain and mRNA degradation. Ago2 knockdown inhibited degradation of the mutant mRNA, while overexpression of Ago2 or knockdown of SRP54 promoted degradation of secretory protein mRNA. The results reveal a previously unappreciated general mechanism of translational quality control, in which specific mRNA degradation preemptively regulates aberrant protein production (RAPP).

A phase I study of intravitreal vascular endothelial growth factor trap-eye in patients with neovascular age-related macular degeneration.

PURPOSE: To determine the safety, tolerability, maximum tolerated dose, and bioactivity of an intravitreal injection of vascular endothelial growth factor (VEGF) Trap-Eye, a fusion protein of binding domains from human VEGF receptors 1 and 2 with human immunoglobulin-G Fc that binds VEGF family members, in patients with neovascular age-related macular degeneration (AMD). DESIGN: Dose-escalation, multicenter, interventional clinical trial. PARTICIPANTS: Twenty-one patients (13 female, 8 male) with neovascular AMD (NVAMD) and lesions or=50% active choroidal neovascularization (CNV) with best-corrected visual acuity (BCVA) or=3 lines and 3 patients requiring no adjunctive treatment of any type for 12 weeks. Some showed elimination of fluorescein leakage and reduction in area of CNV. CONCLUSIONS: Intravitreal injection of up to 4 mg of VEGF Trap-Eye in patients with NVAMD was well tolerated with no evidence of ocular inflammation. Although the number of patients in each cohort was small, there was evidence of bioactivity, because several patients, especially those receiving 2 or 4 mg of VEGF Trap-Eye, showed substantial improvement in BCVA associated with reductions in foveal thickness. Phase III trials to investigate the efficacy of intraocular VEGF Trap-Eye in patients with NVAMD are under way.

Pathogenic Signal Sequence Mutations in Progranulin Disrupt SRP Interactions Required for mRNA Stability.

Cells have evolved quality control pathways to prevent the accumulation of improperly localized proteins, which are often toxic. One of these pathways, regulation of aberrant protein production (RAPP), recognizes aberrant secretory proteins during translation and degrades the associated mRNA. Here, we demonstrate endogenous RAPP substrates. Haploinsufficiency of the secretory protein progranulin (GRN) is associated with the neurodegenerative disease frontotemporal lobar degeneration (FTLD). Our results show FTLD-associated GRN mutations W7R and A9D disrupt co-translational interaction with a targeting factor, signal recognition particle (SRP). This triggers RAPP and initiates specific mRNA degradation. Conversely, wild-type GRN and the naturally occurring polymorphism V5L GRN are efficiently expressed and secreted. Thus, RAPP plays a role in the molecular pathology of A9D GRN and W7R GRN.

Anecortave acetate for the treatment of exudative age-related macular degeneration--a review of clinical outcomes.

PURPOSE: The angiostatic cortisene anecortave acetate was evaluated in three safety and efficacy studies of patients with subfoveal choroidal neovascularization secondary to exudative age-related macular degeneration. METHODS: The Anecortave Acetate Monotherapy Trial enrolled 128 patients randomized to anecortave acetate (3 mg, 15 mg, or 30 mg) or vehicle administered as a sub-Tenon's posterior juxtascleral depot (PJD) at 6-month intervals. The Anecortave Acetate and photodynamic therapy (PDT) with verteporfin Combination Trial enrolled 136 patients randomized to PDT with verteporfin followed by a single depot administration of anecortave acetate (15 mg or 30 mg) or vehicle. The Anecortave Acetate 15 mg versus PDT Comparison Trial enrolled 530 patients to receive either anecortave acetate 15 mg every 6 months + sham PDT every 3 months or PDT with verteporfin every 3 months + sham PJD administration every 6 months. RESULTS: Anecortave acetate 15 mg was statistically superior to vehicle in the monotherapy trial at both 12 and 24 months for maintenance of vision and inhibition of CNV lesion growth. In the combination trial, a trend favored adding either anecortave acetate 15 mg or 30 mg to PDT for these two measures of clinical efficacy, but this short-duration study did not achieve statistical significance. Anecortave acetate 15 mg is comparable to PDT for maintaining vision over the 24-month period in the comparison trial. CONCLUSIONS: Anecortave acetate is safe and effective treatment for exudative age-related macular degeneration.

Verteporfin therapy of subfoveal occult choroidal neovascularization in AMD using delayed light application: one-year results of the VALIO Study.

PURPOSE: To compare photodynamic therapy (PDT) with verteporfin (Visudyne; Novartis Pharma AG, Basel, Switzerland) using either standard or delayed light application. DESIGN: Phase II, multicenter, masked, randomized clinical trial. METHODS: Sixty patients with occult with no classic choroidal neovascularization (CNV) resulting from age-related macular degeneration were assigned randomly (1:1) to verteporfin infusion followed by light application either at 15 minutes (standard light) or 30 minutes (delayed light) after the start of the infusion. The assigned treatment was repeated every three months if fluorescein leakage was detected. RESULTS: At month 12, patients lost a mean of 15.7 letters and 11.4 letters from baseline in the standard and delayed light groups, respectively (P = .38). Twelve (52%) of 23 patients in the standard light group and 11 (42%) of 26 in the delayed light group lost at least 15 letters of visual acuity (P = .57). CONCLUSIONS: There were no statistically significant differences between verteporfin therapy using the delayed light regimen of 30 minutes or the standard light regimen of 15 minutes in eyes with occult with no classic CNV.

Ranibizumab for predominantly classic neovascular age-related macular degeneration: subgroup analysis of first-year ANCHOR results.

PURPOSE: Subgroup data from a pivotal phase 3 study comparing ranibizumab (LUCENTIS) with verteporfin (VISUDYNE) photodynamic therapy (PDT) in patients with predominantly classic choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) were retrospectively analyzed to identify patient and disease characteristics that may predict visual acuity (VA) treatment outcomes. DESIGN: Retrospective subgroup analysis of 12-month data from the ANCHOR study. METHODS: Univariate analyses were performed to assess VA outcomes across subgroups based on patients' gender and baseline age, VA score, CNV lesion size, CNV lesion type, and duration of neovascular AMD, followed by multivariate analyses to identify predictors of the VA score change from baseline at 12 months. main outcome measures: Proportion of patients losing <15 letters and proportion gaining > or =15 letters from baseline VA; mean change from baseline VA. RESULTS: On average, all subgroups of ranibizumab-treated patients did better than PDT patients for all three VA outcome measures. In the multivariate analysis, lower baseline VA score, smaller baseline CNV lesion size, and younger baseline age were associated with greater gain of letters with ranibizumab treatment and less loss of letters with PDT. CONCLUSIONS: Subgroup analysis of 12-month data from the ANCHOR study showed ranibizumab to be superior to PDT in all subgroups evaluated, and was consistent with the subgroup analysis of 24-month data from the other pivotal phase 3 study of ranibizumab (MARINA) in showing that the most important predictors of VA outcomes were, in decreasing order of impact, the patient's baseline VA score, CNV lesion size, and age.

Combination verteporfin photodynamic therapy ranibizumab-dexamethasone in choroidal neovascularization due to age-related macular degeneration: results of a phase II randomized trial.

PURPOSE: To assess whether combination therapy (CT) reduces retreatments when compared to ranibizumab monotherapy (RM), while safely maintaining similar vision outcomes. METHODS: In this 24-month trial, patients with age-related macular degeneration (AMD) were randomized to 1) quarter-fluence or 2) half-fluence triple therapy (verteporfin photodynamic therapy [vPDT] + ranibizumab + dexamethasone), 3) half-fluence double therapy (vPDT + ranibizumab), or 4) RM. The primary outcomes were number of retreatment visits and change from baseline in visual acuity (VA) at 12 months. RESULTS: One hundred sixty-two subjects enrolled. There were 4.0 (P=0.02), 3.2 (P<0.001), 4.1 (P=0.03), and 5.7 retreatment visits through month 12, and 5.9 (P=0.03), 4.3 (P<0.001), 5.9 (P=0.02) and 8.7 through month 24, in groups 1, 2, 3, and 4, respectively (P-value comparing with RM). Month 12 VA score change from baseline (95% confidence interval) was +3.6 (-0.9 to +8.1), +6.8 (+2.4 to +11.1), +5.0 (+0.6 to +9.3), and +6.5 (+1.7 to +11.4), respectively. CONCLUSION: CT resulted in significantly fewer retreatment visits than a RM regimen at months 12 and 24. VA results appeared similar although wide confidence intervals preclude conclusions regarding vision outcomes.

Implantable miniature telescope for the treatment of visual acuity loss resulting from end-stage age-related macular degeneration: 1-year results.

PURPOSE: To evaluate the safety and efficacy of an implantable visual prosthetic device (IMT; VisionCare Ophthalmic Technologies, Saratoga, CA) in patients with bilateral, end-stage age-related macular degeneration (AMD). DESIGN: Prospective, open-label, multicenter clinical trial with fellow eye controls. PARTICIPANTS: A total of 217 patients (mean age, 76 years) with AMD and moderate to profound bilateral central visual acuity loss (20/80-20/800) resulting from bilateral untreatable geographic atrophy, disciform scars, or both were enrolled. METHODS: A visual prosthetic device (implantable telescope), designed to enlarge retinal images of the central visual field, was implanted monocularly in the capsular bag after lens extraction. Fellow eyes were not implanted to provide peripheral vision and served as controls. Study patients participated in 6 visual rehabilitation visits after surgery. MAIN OUTCOME MEASURES: Best-corrected distance visual acuity (BCDVA) and best-corrected near visual acuity (BCNVA), quality-of-life scores from the National Eye Institute 25-item Visual Function Questionnaire (NEI VFQ-25) and the Activities of Daily Life scale, endothelial cell density (ECD), and incidence of complications and adverse events. RESULTS: At 1 year, 67% of implanted eyes achieved a 3-line or more improvement in BCDVA versus 13% of fellow eye controls (P<0.0001). Fifty-three percent of implanted eyes achieved a 3-line or more improvement in both BCDVA and BCNVA versus 10% of fellow eyes (P<0.0001). Mean BCDVA and BCNVA improved 3.5 lines and 3.2 lines, respectively, in implanted eyes versus 0.8 lines and 1.8 lines, respectively, in fellow eyes (P<0.0001). Change in visual acuity was not related to lesion type. Mean NEI VFQ-25 scores improved by more than 7 points from baseline (P<0.01) on 7 of 8 relevant subscales. Eleven eyes did not receive the device because of an aborted procedure. Endothelial cell density was reduced by 20% at 3 months and 25% at 1 year. The decrease in ECD was correlated with postsurgical edema (P<0.0001), and there was no evidence that endothelial cell loss is accelerated by ongoing endothelial trauma after implantation. CONCLUSIONS: This implantable visual prosthesis can improve visual acuity and quality of life in patients with moderate to profound visual impairment caused by bilateral, end-stage AMD.

N-Alpha-Acetyltransferases and Regulation of CFTR Expression.

The majority of cystic fibrosis (CF)-causing mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) lead to the misfolding, mistrafficking, and degradation of the mutant protein. Inhibition of degradation does not effectively increase the amount of trafficking competent CFTR, but typically leads to increased ER retention of misfolded forms. Thus, the initial off pathway steps occur early in the processing of the protein. To identify proteins that interact with these early forms of CFTR, in vitro crosslink experiments identified cotranslational partners of the nascent chain of the severe misfolded mutant, G85E CFTR. The mutant preferentially interacts with a subunit of an N-alpha-acetyltransferase A. Based on recent reports that acetylation of the N-termini of some N-end rule substrates control their ubiquitination and subsequent degradation, a potential role for this modification in regulation of CFTR expression was assessed. Knockdown experiments identified two complexes, which affect G85E CFTR proteins levels, NatA and NatB. Effects of the knockdowns on mRNA levels, translation rates, and degradation rates established that the two complexes regulate G85E CFTR through two separate mechanisms. NatA acts indirectly by regulating transcription levels and NatB acts through a previously identified, but incompletely understood posttranslational mechanism. This regulation did not effect trafficking of G85E CFTR, which remains retained in the ER, nor did it alter the degradation rate of CFTR. A mutation predicted to inhibit N-terminal acetylation of CFTR, Q2P, was without effect, suggesting neither system acts directly on CFTR. These results contradict the prediction that N-terminal acetylation of CFTR determines its fitness as a proteasome substrate, but rather NatB plays a role in the conformational maturation of CFTR in the ER through actions on an unidentified protein.

Evaluation of very high- and very low-dose intravitreal aflibercept in patients with neovascular age-related macular degeneration.

PURPOSE: To determine bioactivity and duration of effect of intravitreal aflibercept injection (also known as vascular endothelial growth factor Trap-Eye) for neovascular age-related macular degeneration (AMD). METHODS: In this double-masked, phase 1 study, 28 patients with lesions ≤12 disc areas, ≥50% active choroidal neovascularization (CNV), and best corrected visual acuity (BCVA) ≤20/40 were randomized 1:1 to a single intravitreal injection of aflibercept 0.15 or 4 mg. The primary end point was the change from baseline in central retinal/lesion thickness (CR/LT) at week-8. Secondary outcomes were the change from baseline BCVA, the change in CNV lesion size and area of leakage, and proportion of patients requiring repeat injection at 8 weeks. RESULTS: Mean percent decrease in CR/LT for the 4-mg and 0.15-mg groups was, respectively, 34.2 versus 13.3 at week 4 (P=0.0065), 23.8 versus 5.9 at week 6 (P=0.0380), and 25.2% versus 11.3% at week 8 (P=0.150). The 4-mg group gained a mean of 4.5 letters in BCVA (6/14 patients gaining ≥10 letters) versus 1.1 letters in 0.15-mg group (1/14 gaining ≥10 letters) at week 8. Fewer patients needed retreatment in the 4-mg group at week 8. No serious adverse event or ocular inflammation was reported in either group. CONCLUSIONS: Intravitreal aflibercept 4 mg had a safety profile similar to that of the very low dose 0.15 mg, and was well-tolerated. The 4-mg dose significantly reduced foveal thickening at weeks 4 and 6, significantly improved BCVA at weeks 6, and reduced the need for repeat injection after 8 weeks compared with intravitreal aflibercept 0.15 mg in neovascular AMD patients.

Implantable telescope for end-stage age-related macular degeneration: long-term visual acuity and safety outcomes.

PURPOSE: To evaluate long-term safety and best-corrected visual acuity (BCVA) results of a telescope prosthesis in patients with end-stage age-related macular degeneration (AMD). DESIGN: Prospective, open-label clinical trial with fellow-eye controls. METHODS: Patients with end-stage AMD (bilateral geographic atrophy or disciform scars; BCVA, 20/80 to 20/800) received the telescope prosthesis at 28 centers. Methods were similar to those described in the one-year results, with follow-up visits continuing at 18 and 24 months. Main outcome measures included BCVA change from baseline, endothelial cell density (ECD) and morphometry, and incidence of complications. RESULTS: At two years, data from 174 (92.6%) of 188 available patients were analyzed. Overall, 103 (59.5%) of 173 telescope-implanted eyes gained three lines or more (doubling of visual angle) of BCVA compared with 18 (10.3%) of 174 fellow control eyes (P < .0001). Mean BCVA improved 3.6 lines (standard deviation [SD], 1.9 lines) and 2.8 lines (SD, 2.3 lines) from baseline in eyes with the 3X and 2.2X device models, respectively. Mean ECD stabilized through two years, with 2.4% mean cell loss occurring from one to two years. There was no significant change in coefficient of variation or percentage of hexagonal endothelial cells from within six months to two years after surgery. The most common complication was inflammatory deposits. CONCLUSIONS: Long-term results of this telescope prosthesis show the substantial BCVA improvement at one year is maintained at two years. Key indicators of corneal health demonstrate ECD change that reflects remodeling of the endothelium associated with the implantation procedure. ECD stabilizes over time, and there is no evidence of any ongoing endothelial trauma.

Massive mycobacterial choroiditis during highly active antiretroviral therapy: another immune-recovery uveitis?

PURPOSE: To describe the ocular presentation of disseminated mycobacterial disease occurring during immune-recovery in a patient with acquired immune deficiency syndrome (AIDS). STUDY DESIGN: Case report and literature review. PARTICIPANTS: A 41-year-old AIDS patient with a prior diagnosis of cytomegalovirus retinitis. METHODS: The patient developed progressive, bilateral multifocal choroiditis with panuveitis 2 months after beginning and responding to highly active antiretroviral therapy. His left eye became blind and painful and was enucleated. Pathologic examination revealed massive choroiditis with well-formed, discrete granulomas and multiple intracellular and extracellular acid-fast organisms within the choroidal granulomas. Culture and polymerase chain reaction of vitreous specimens revealed Mycobacterium avium complex (MAC). RESULTS: Empiric, and later sensitivity-guided, local and systemic antibiotic therapy was used to treat the remaining right eye, but it continued to deteriorate. Despite medical therapy, three vitrectomies and repeated intravitreal injections of amikacin, a total retinal detachment ensued. One week after the third vitrectomy, the patient died from mesenteric artery thrombosis in the setting of disseminated mycobacterial disease. CONCLUSIONS: This is the first report of ocular inflammation as the presenting finding in the recently recognized syndrome of immune-recovery MAC disease. Pathogenesis of this entity is related to an enhanced immune response to a prior, subclinical, disseminated infection. The formation of discrete granulomas, normally absent in MAC infections in AIDS, reflects this mechanism.

Anecortave acetate as monotherapy for treatment of subfoveal neovascularization in age-related macular degeneration: twelve-month clinical outcomes.

PURPOSE: To evaluate safety and efficacy of the angiostatic agent anecortave acetate, compared with a placebo, for treatment of subfoveal choroidal neovascularization (CNV). DESIGN: Ongoing masked, randomized, placebo-controlled, parallel evaluation of anecortave acetate (30 mg, 15 mg, and 3 mg) versus a placebo. PARTICIPANTS: There were 128 eyes of 128 patients with subfoveal CNV secondary to age-related macular degeneration who were enrolled and treated, with 80% (102/128) of eyes presenting with predominantly classic lesions at baseline. METHODS: All eyes received a posterior juxtascleral depot application of masked study medication or a placebo, with retreatment at 6-month intervals if the masked investigator believed the patient could benefit. Patients received periodic detailed ophthalmic examinations with both fluorescein and indocyanine green angiography, general physical examinations with electrocardiograms, and hematology/serum chemistry/urinalysis. All ophthalmic and systemic safety data were periodically reviewed by the Independent Safety Committee overseeing the study. MAIN OUTCOME MEASURES: Best-corrected logarithm of the minimum angle of resolution (logMAR) vision and fluorescein angiographic lesion characteristics were compared over time and among treatment groups. RESULTS: At month 12, anecortave acetate (15 mg) administered at 6-month intervals was statistically superior to the placebo for 3 measures of clinical efficacy: mean change from baseline vision (P = 0.0131), stabilization of vision (<3 logMAR line change; P = 0.0323), and prevention of severe vision loss (decrease of > or = 6 logMAR lines from baseline; P = 0.0224). Subgroup analysis of predominantly classic lesions revealed that anecortave acetate (15 mg) was also superior to the placebo at 1 year for each of these 3 measures of visual outcome (Ps = 0.0022, 0.0100, and 0.0299, respectively). Anecortave acetate (15 mg) trended toward significance over the placebo at month 12 for inhibition of total lesion growth and for inhibition of both the total CNV component and the classic CNV component in both the overall and subgroup analyses. The Independent Safety Committee identified no clinically relevant treatment-related safety issues. CONCLUSIONS: Anecortave acetate (15 mg) is safe and clinically efficacious at 1 year for maintaining vision, preventing severe vision loss, and inhibiting subfoveal CNV lesion growth.

Anecortave acetate as monotherapy for the treatment of subfoveal lesions in patients with exudative age-related macular degeneration (AMD): interim (month 6) analysis of clinical safety and efficacy.

PURPOSE: To evaluate clinical safety and efficacy of the angiostatic agent anecortave acetate for treatment of subfoveal choroidal neovascularization secondary to AMD. METHODS: 128 patients were randomized to placebo treatment or one of three anecortave acetate doses. Study medication was administered as a posterior juxtascleral injection onto the posterior scleral surface. Best-corrected logMAR vision was obtained at baseline and follow-up visits. Fluorescein angiograms were evaluated for eligibility before enrollment and posttreatment. RESULTS: Six months after a single treatment, visual acuity (mean change from baseline logMAR values) was significantly better (P = 0.003) after anecortave acetate 15 mg than placebo. More patients treated with anecortave acetate 15 mg than placebo maintained vision (88% versus 70%, P = 0.080), especially those with predominantly classic lesions (92% versus 65%, P = 0.021). Anecortave acetate 15 mg inhibited lesion growth significantly better than placebo (P = 0.001). Trends favoring the other doses over placebo were observed for vision preservation and lesion inhibition, but statistical significance was not achieved. The Independent Safety Committee overseeing this study identified no clinically relevant treatment-related changes. CONCLUSION: Anecortave acetate 15 mg is safe and effective for preserving or improving vision and for inhibiting lesion growth in patients with subfoveal AMD.