Two Distinct Types of E3 Ligases Work in Unison to Regulate Substrate Ubiquitylation.

Hundreds of human cullin-RING E3 ligases (CRLs) modify thousands of proteins with ubiquitin (UB) to achieve vast regulation. Current dogma posits that CRLs first catalyze UB transfer from an E2 to their client substrates and subsequent polyubiquitylation from various linkage-specific E2s. We report an alternative E3-E3 tagging cascade: many cellular NEDD8-modified CRLs associate with a mechanistically distinct thioester-forming RBR-type E3, ARIH1, and rely on ARIH1 to directly add the first UB and, in some cases, multiple additional individual monoubiquitin modifications onto CRL client substrates. Our data define ARIH1 as a component of the human CRL system, demonstrate that ARIH1 can efficiently and specifically mediate monoubiquitylation of several CRL substrates, and establish principles for how two distinctive E3s can reciprocally control each other for simultaneous and joint regulation of substrate ubiquitylation. These studies have broad implications for CRL-dependent proteostasis and mechanisms of E3-mediated UB ligation.

Directed conversion of Alzheimer's disease patient skin fibroblasts into functional neurons.

Directed conversion of mature human cells, as from fibroblasts to neurons, is of potential clinical utility for neurological disease modeling as well as cell therapeutics. Here, we describe the efficient generation of human-induced neuronal (hiN) cells from adult skin fibroblasts of unaffected individuals and Alzheimer's patients, using virally transduced transcription regulators and extrinsic support factors. hiN cells from unaffected individuals display morphological, electrophysiological, and gene expression profiles that typify glutamatergic forebrain neurons and are competent to integrate functionally into the rodent CNS. hiN cells from familial Alzheimer disease (FAD) patients with presenilin-1 or -2 mutations exhibit altered processing and localization of amyloid precursor protein (APP) and increased production of Aß, relative to the source patient fibroblasts or hiN cells from unaffected individuals. Together, our findings demonstrate directed conversion of human fibroblasts to a neuronal phenotype and reveal cell type-selective pathology in hiN cells derived from FAD patients.

A protein complex network of Drosophila melanogaster.

Determining the composition of protein complexes is an essential step toward understanding the cell as an integrated system. Using coaffinity purification coupled to mass spectrometry analysis, we examined protein associations involving nearly 5,000 individual, FLAG-HA epitope-tagged Drosophila proteins. Stringent analysis of these data, based on a statistical framework designed to define individual protein-protein interactions, led to the generation of a Drosophila protein interaction map (DPiM) encompassing 556 protein complexes. The high quality of the DPiM and its usefulness as a paradigm for metazoan proteomes are apparent from the recovery of many known complexes, significant enrichment for shared functional attributes, and validation in human cells. The DPiM defines potential novel members for several important protein complexes and assigns functional links to 586 protein-coding genes lacking previous experimental annotation. The DPiM represents, to our knowledge, the largest metazoan protein complex map and provides a valuable resource for analysis of protein complex evolution.

Mapping hospital data to characterize residents' educational experiences.

BACKGROUND: Experiential learning through patient care is fundamental to graduate medical education. Despite this, the actual content to which trainees are exposed in clinical practice is difficult to quantify and is poorly characterized. There remains an unmet need to define precisely how residents' patient care activities inform their educational experience.  METHODS: Using a recently-described crosswalk tool, we mapped principal ICD-10 discharge diagnosis codes to American Board of Internal Medicine (ABIM) content at four training hospitals of a single Internal Medicine (IM) Residency Program over one academic year to characterize and compare residents' clinical educational experiences. Frequencies of broad content categories and more specific condition categories were compared across sites to profile residents' aggregate inpatient clinical experiences and drive curricular change. RESULTS: There were 18,604 discharges from inpatient resident teams during the study period. The crosswalk captured > 95% of discharges at each site. Infectious Disease (ranging 17.4 to 39.5% of total discharges) and Cardiovascular Disease (15.8 to 38.2%) represented the most common content categories at each site. Several content areas (Allergy/Immunology, Dermatology, Obstetrics/Gynecology, Ophthalmology, Otolaryngology/Dental Medicine) were notably underrepresented (≤ 1% at each site). There were significant differences in the frequencies of conditions within most content categories, suggesting that residents experience distinct site-specific clinical content during their inpatient training. CONCLUSIONS: There were substantial differences in the clinical content experienced by our residents across hospital sites, prompting several important programmatic and curricular changes to enrich our residents' hospital-based educational experiences.

Endoscopy-guided transesophageal echocardiography for large esophageal varices: Use of the "Double Barrel" technique.

Rhythm control strategies in patients with esophageal varices and atrial arrhythmias pose a unique challenge. The left atrium should be imaged for a thrombus prior to attempting cardioversion or ablation, but the presence of varices is a relative contraindication for transesophageal echocardiography. We present a safe, novel technique of evaluating for left atrial thrombus with simultaneous transesophageal echocardiography and esophagogastroduodenoscopy using slim probes in a patient with large, high-risk esophageal varices, and symptomatic atrial flutter with rapid ventricular rates despite medical therapy.

Two cases of acute endocarditis misdiagnosed as COVID-19 infection.

The COVID-19 pandemic has presented countless new challenges for healthcare providers including the challenge of differentiating COVID-19 infection from other diseases. COVID-19 infection and acute endocarditis may present similarly, both with shortness of breath and vital sign abnormalities, yet they require very different treatments. Here, we present two cases in which life-threatening acute endocarditis was initially misdiagnosed as COVID-19 infection during the height of the pandemic in New York City. The first was a case of Klebsiella pneumoniae mitral valve endocarditis leading to papillary muscle rupture and severe mitral regurgitation, and the second a case of Streptococcus mitis aortic valve endocarditis with heart failure due to severe aortic regurgitation. These cases highlight the importance of careful clinical reasoning and demonstrate how cognitive errors may impact clinical reasoning. They also underscore the limitations of real-time reverse transcription-polymerase chain reaction (RT-PCR) for SARS-CoV-2 testing and illustrate the ways in which difficulty interpreting results may also influence clinical reasoning. Accurate diagnosis of acute endocarditis is critical given that surgical intervention can be lifesaving in unstable patients.

Hepcidin Deficiency Protects Against Atherosclerosis.

Objective- Inflammatory stimuli enhance the progression of atherosclerotic disease. Inflammation also increases the expression of hepcidin, a hormonal regulator of iron homeostasis, which decreases intestinal iron absorption, reduces serum iron levels and traps iron within macrophages. The role of macrophage iron in the development of atherosclerosis remains incompletely understood. The objective of this study was to investigate the effects of hepcidin deficiency and decreased macrophage iron on the development of atherosclerosis. Approach and Results- Hepcidin- and LDL (low-density lipoprotein) receptor-deficient ( Hamp-/-/ Ldlr-/-) mice and Hamp+/+/ Ldlr-/- control mice were fed a high-fat diet for 21 weeks. Compared with control mice, Hamp-/-/ Ldlr-/- mice had decreased aortic macrophage activity and atherosclerosis. Because hepcidin deficiency is associated with both increased serum iron and decreased macrophage iron, the possibility that increased serum iron was responsible for decreased atherosclerosis in Hamp-/-/ Ldlr-/- mice was considered. Hamp+/+/ Ldlr-/- mice were treated with iron dextran so as to produce a 2-fold increase in serum iron. Increased serum iron did not decrease atherosclerosis in Hamp+/+/ Ldlr-/- mice. Aortic macrophages from Hamp-/-/ Ldlr-/- mice had less labile free iron and exhibited a reduced proinflammatory (M1) phenotype compared with macrophages from Hamp+/+/ Ldlr-/- mice. THP1 human macrophages treated with an iron chelator were used to model hepcidin deficiency in vitro. Treatment with an iron chelator reduced LPS (lipopolysaccharide)-induced M1 phenotypic expression and decreased uptake of oxidized LDL. Conclusions- In summary, in a hyperlipidemic mouse model, hepcidin deficiency was associated with decreased macrophage iron, a reduced aortic macrophage inflammatory phenotype and protection from atherosclerosis. The results indicate that decreasing hepcidin activity, with the resulting decrease in macrophage iron, may prove to be a novel strategy for the treatment of atherosclerosis.

Blocking an N-terminal acetylation-dependent protein interaction inhibits an E3 ligase.

N-terminal acetylation is an abundant modification influencing protein functions. Because ∼80% of mammalian cytosolic proteins are N-terminally acetylated, this modification is potentially an untapped target for chemical control of their functions. Structural studies have revealed that, like lysine acetylation, N-terminal acetylation converts a positively charged amine into a hydrophobic handle that mediates protein interactions; hence, this modification may be a druggable target. We report the development of chemical probes targeting the N-terminal acetylation-dependent interaction between an E2 conjugating enzyme (UBE2M or UBC12) and DCN1 (DCUN1D1), a subunit of a multiprotein E3 ligase for the ubiquitin-like protein NEDD8. The inhibitors are highly selective with respect to other protein acetyl-amide-binding sites, inhibit NEDD8 ligation in vitro and in cells, and suppress anchorage-independent growth of a cell line with DCN1 amplification. Overall, our data demonstrate that N-terminal acetyl-dependent protein interactions are druggable targets and provide insights into targeting multiprotein E2-E3 ligases.

Early-stage epigenetic modification during somatic cell reprogramming by Parp1 and Tet2.

Somatic cells can be reprogrammed into induced pluripotent stem cells (iPSCs) by using the pluripotency factors Oct4, Sox2, Klf4 and c-Myc (together referred to as OSKM). iPSC reprogramming erases somatic epigenetic signatures­as typified by DNA methylation or histone modification at silent pluripotency loci­and establishes alternative epigenetic marks of embryonic stem cells (ESCs). Here we describe an early and essential stage of somatic cell reprogramming, preceding the induction of transcription at endogenous pluripotency loci such as Nanog and Esrrb. By day 4 after transduction with OSKM, two epigenetic modification factors necessary for iPSC generation, namely poly(ADP-ribose) polymerase-1 (Parp1) and ten-eleven translocation-2 (Tet2), are recruited to the Nanog and Esrrb loci. These epigenetic modification factors seem to have complementary roles in the establishment of early epigenetic marks during somatic cell reprogramming: Parp1 functions in the regulation of 5-methylcytosine (5mC) modification, whereas Tet2 is essential for the early generation of 5-hydroxymethylcytosine (5hmC) by the oxidation of 5mC (refs 3,4). Although 5hmC has been proposed to serve primarily as an intermediate in 5mC demethylation to cytosine in certain contexts, our data, and also studies of Tet2-mutant human tumour cells, argue in favour of a role for 5hmC as an epigenetic mark distinct from 5mC. Consistent with this, Parp1 and Tet2 are each needed for the early establishment of histone modifications that typify an activated chromatin state at pluripotency loci, whereas Parp1 induction further promotes accessibility to the Oct4 reprogramming factor. These findings suggest that Parp1 and Tet2 contribute to an epigenetic program that directs subsequent transcriptional induction at pluripotency loci during somatic cell reprogramming.

BMP type I receptor ALK2 is required for angiotensin II-induced cardiac hypertrophy.

Bone morphogenetic protein (BMP) signaling contributes to the development of cardiac hypertrophy. However, the identity of the BMP type I receptor involved in cardiac hypertrophy and the underlying molecular mechanisms are poorly understood. By using quantitative PCR and immunoblotting, we demonstrated that BMP signaling increased during phenylephrine-induced hypertrophy in cultured neonatal rat cardiomyocytes (NRCs), as evidenced by increased phosphorylation of Smads 1 and 5 and induction of Id1 gene expression. Inhibition of BMP signaling with LDN193189 or noggin, and silencing of Smad 1 or 4 using small interfering RNA diminished the ability of phenylephrine to induce hypertrophy in NRCs. Conversely, activation of BMP signaling with BMP2 or BMP4 induced hypertrophy in NRCs. Luciferase reporter assay further showed that BMP2 or BMP4 treatment of NRCs repressed atrogin-1 gene expression concomitant with an increase in calcineurin protein levels and enhanced activity of nuclear factor of activated T cells, providing a mechanism by which BMP signaling contributes to cardiac hypertrophy. In a model of cardiac hypertrophy, C57BL/6 mice treated with angiotensin II (A2) had increased BMP signaling in the left ventricle. Treatment with LDN193189 attenuated A2-induced cardiac hypertrophy and collagen deposition in left ventricles. Cardiomyocyte-specific deletion of BMP type I receptor ALK2 (activin-like kinase 2), but not ALK1 or ALK3, inhibited BMP signaling and mitigated A2-induced cardiac hypertrophy and left ventricular fibrosis in mice. The results suggest that BMP signaling upregulates the calcineurin/nuclear factor of activated T cell pathway via BMP type I receptor ALK2, contributing to cardiac hypertrophy and fibrosis.

Toward precision medical education: Characterizing individual residents' clinical experiences throughout training.

BACKGROUND: Despite the central role of experiential learning in residency training, the actual clinical experiences residents participate in are not well characterized. A better understanding of the type, volume, and variation in residents' clinical experiences is essential to support precision medical education strategies. OBJECTIVE: We sought to characterize the entirety of the clinical experiences had by individual internal medicine residents throughout their time in training. METHOD: We evaluated the clinical experiences of medicine residents (n = 51) who completed training at NYU Grossman School of Medicine's Brooklyn campus between 2020 and 2023. Residents' inpatient and outpatient experiences were identified using notes written, orders placed, and care team sign-ins; principal ICD-10 codes for each encounter were converted into medical content categories using a previously described crosswalk tool. RESULTS: Of 152,426 clinical encounters with available ICD-10 codes, 132,284 were mapped to medical content categories (94.5% capture). Residents' clinical experiences were particularly enriched in infectious and cardiovascular disease; most had very little exposure to allergy, dermatology, oncology, or rheumatology. Some trainees saw twice as many cases in a given content area as did others. There was little concordance between actual frequency of clinical experience and expected content frequency on the ABIM certification exam. CONCLUSIONS: Individual residents' clinical experiences in training vary widely, both in number and in type. Characterizing these experiences paves the way for exploration of the relationships between clinical exposure and educational outcomes, and for the implementation of precision education strategies that could fill residents' experiential gaps and complement strengths with targeted educational interventions.

Characterization of oxidative guanine damage and repair in mammalian telomeres.

8-oxo-7,8-dihydroguanine (8-oxoG) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyG) are among the most common oxidative DNA lesions and are substrates for 8-oxoguanine DNA glycosylase (OGG1)-initiated DNA base excision repair (BER). Mammalian telomeres consist of triple guanine repeats and are subject to oxidative guanine damage. Here, we investigated the impact of oxidative guanine damage and its repair by OGG1 on telomere integrity in mice. The mouse cells were analyzed for telomere integrity by telomere quantitative fluorescence in situ hybridization (telomere-FISH), by chromosome orientation-FISH (CO-FISH), and by indirect immunofluorescence in combination with telomere-FISH and for oxidative base lesions by Fpg-incision/Southern blot assay. In comparison to the wild type, telomere lengthening was observed in Ogg1 null (Ogg1(-/-)) mouse tissues and primary embryonic fibroblasts (MEFs) cultivated in hypoxia condition (3% oxygen), whereas telomere shortening was detected in Ogg1(-/-) mouse hematopoietic cells and primary MEFs cultivated in normoxia condition (20% oxygen) or in the presence of an oxidant. In addition, telomere length abnormalities were accompanied by altered telomere sister chromatid exchanges, increased telomere single- and double-strand breaks, and preferential telomere lagging- or G-strand losses in Ogg1(-/-) mouse cells. Oxidative guanine lesions were increased in telomeres in Ogg1(-/-) mice with aging and primary MEFs cultivated in 20% oxygen. Furthermore, oxidative guanine lesions persisted at high level in Ogg1(-/-) MEFs after acute exposure to hydrogen peroxide, while they rapidly returned to basal level in wild-type MEFs. These findings indicate that oxidative guanine damage can arise in telomeres where it affects length homeostasis, recombination, DNA replication, and DNA breakage repair. Our studies demonstrate that BER pathway is required in repairing oxidative guanine damage in telomeres and maintaining telomere integrity in mammals.

CRISPR Screen Reveals BRD2/4 Molecular Glue-like Degrader via Recruitment of DCAF16.

Molecular glues (MGs) are monovalent small molecules that induce an interaction between proteins (native or non-native partners) by altering the protein-protein interaction (PPI) interface toward a higher-affinity state. Enhancing the PPI between a protein and E3 ubiquitin ligase can lead to degradation of the partnering protein. Over the past decade, retrospective studies of clinical drugs identified that immunomodulatory drugs (e.g., thalidomide and analogues) and indisulam exhibit a molecular glue effect by driving the interaction between non-native substrates to CRBN and DCAF15 ligases, respectively. Ensuing reports of phenotypic screens focused on MG discovery have suggested that these molecules may be more common than initially anticipated. However, prospective discovery of MGs remains challenging. Thus, expanding the repertoire of MGs will enhance our understanding of principles for prospective design. Herein, we report the results of a CRISPR/Cas9 knockout screen of over 1000 ligases and ubiquitin proteasome system components in a BRD4 degradation assay with a JQ1-based monovalent degrader, compound 1a. We identified DCAF16, a substrate recognition component of the Cul4 ligase complex, as essential for compound activity, and we demonstrate that compound 1a drives the interaction between DCAF16 and BRD2/4 to promote target degradation. Taken together, our data suggest that compound 1a functions as an MG degrader between BRD2/4 and DCAF16 and provides a foundation for further mechanistic dissection to advance prospective MG discovery.

FANCC suppresses short telomere-initiated telomere sister chromatid exchange.

Telomere shortening has been linked to rare human disorders that present with bone marrow failure including Fanconi anemia (FA). FANCC is one of the most commonly mutated FA genes in FA patients and the FANCC subtype tends to have a relatively early onset of bone marrow failure and hematologic malignancies. Here, we studied the role of Fancc in telomere length regulation in mice. Deletion of Fancc (Fancc(-/-)) did not affect telomerase activity, telomere length or telomeric end-capping in a mouse strain possessing intrinsically long telomeres. However, ablation of Fancc did exacerbate telomere attrition when murine bone marrow cells experienced high cell turnover after serial transplantation. When Fancc(-/-) mice were crossed into a telomerase reverse transcriptase heterozygous or null background (Tert(+/-) or Tert(-/-)) with short telomeres, Fancc deficiency led to an increase in the incidence of telomere sister chromatid exchange. In contrast, these phenotypes were not observed in Tert mutant mice with long telomeres. Our data indicate that Fancc deficiency accelerates telomere shortening during high turnover of hematopoietic cells and promotes telomere recombination initiated by short telomeres.

Connexin 43 regulates epicardial cell polarity and migration in coronary vascular development.

Connexin 43 knockout (Cx43 KO) mice exhibit conotruncal malformations and coronary artery defects. We observed epicardial blisters in the Cx43 KO hearts that suggest defects in epicardial epithelial-mesenchymal transformation (EMT), a process that generates coronary vascular progenitors. Analysis using a three-dimensional collagen gel invasion assay showed that Cx43 KO epicardial cells are less invasive and that, unlike wild-type epicardial cells, they fail to organize into thin vessel-like projections. Examination of Cx43 KO hearts using Wt1 as an epicardial marker revealed a disorganized pattern of epicardial cell infiltration. Time-lapse imaging and motion analysis using epicardial explants showed a defect in directional cell migration. This was associated with changes in the actin/tubulin cytoskeleton. A defect in cell polarity was indicated by a failure of the microtubule-organizing center to align with the direction of cell migration. Forced expression of Cx43 constructs in epicardial explants showed the Cx43 tubulin-binding domain is required for Cx43 modulation of cell polarity and cell motility. Pecam staining revealed early defects in remodeling of the primitive coronary vascular plexuses in the Cx43 KO heart. Together, these findings suggest an early defect in coronary vascular development arising from a global perturbation of the cytoarchitecture of the cell. Consistent with this, we found aberrant myocardialization of the outflow tract, a process also known to be EMT dependent. Together, these findings suggest cardiac defects in the Cx43 KO mice arise from the disruption of cell polarity, a process that may be dependent on Cx43-tubulin interactions.

Short-term outcomes of infants born to mothers with SARS-CoV-2 infection.

OBJECTIVE: The rate of transmission of SARS-CoV-2 from mothers to infants in the peri- and post-natal period remains an area of ongoing investigation. This study aims to determine rates of development of clinically significant COVID-19 disease within 1 month among infants born to symptomatic and asymptomatic SARS-CoV-2 positive mothers. MATERIALS AND METHODS: This was a single-center, retrospective cohort study of all infants born to SARS-CoV-2 positive mothers who were admitted to the Well Baby Nursery (WBN) at New York University Langone Hospital-Brooklyn from 23 March-23 September 2020. Infants born to asymptomatic mothers were allowed to room-in, while infants born to mothers with symptoms of SARS-CoV-2 were isolated and discharged home to an alternate primary caregiver. A phone follow-up program contacted mothers at 2 weeks and 1 month post discharge to inquire about newborn symptoms, maternal symptoms, personal protective equipment (PPE) usage, and any presentations to care. Medical records were also reviewed for clinic and hospital visits to determine if exposed infants developed any symptoms following discharge. RESULTS: Of 1903 deliveries during the study period, 131 mothers (21 symptomatic, 110 asymptomatic) tested positive for SARS-CoV-2 and had infants admitted to the WBN. 57 infants (21 born to symptomatic mothers, 36 born to asymptomatic mothers) were tested prior to discharge, and none were positive. 121 of 133 infants had at least 1 follow up call in the study period. Of these, 31 had symptoms potentially concerning for SARS-CoV-2 infection or Multisystem Inflammatory Syndrome in Children, and 19 presented to medical care for these symptoms. 4 infants had SARS- CoV-2 testing after discharge, and none were positive. 2 infants were admitted to the hospital for fever but neither had a positive SARS-CoV-2 result. 65% of mothers reported always adhering to PPE recommendations. CONCLUSION: Our results suggest that infants born both to symptomatic and asymptomatic mothers are unlikely to develop clinically significant COVID-19 disease in the peri- and post-natal periods.

Experience and Education in Residency Training: Capturing the Resident Experience by Mapping Clinical Data.

PROBLEM: Internal medicine training programs operate under the assumption that the 3-year residency training period is sufficient for trainees to achieve the depth and breadth of clinical experience necessary for independent practice; however, the medical conditions to which residents are exposed in clinical practice are not easily measured. As a result, residents' clinical educational experiences are poorly understood. APPROACH: A crosswalk tool (a repository of International Classification of Diseases [ICD]-10 codes linked to medical content areas) was developed to query routinely collected inpatient principal diagnosis codes and translate them into an educationally meaningful taxonomy. This tool provides a robust characterization of residents' inpatient clinical experiences. OUTCOMES: This pilot study has provided proof of principle that the crosswalk tool can effectively map 1 year of resident-attributed diagnosis codes to both the broad content category level (e.g., "cardiovascular disease") and to the more specific condition category level (e.g., "myocardial disease"). The authors uncovered content areas in their training program that are overrepresented and some that are underrepresented relative to material on the American Board of Internal Medicine (ABIM) Certification Exam. NEXT STEPS: The crosswalk tool introduced here translated residents' patient care activities into discrete, measurable educational content and enabled 1 internal medicine residency program to characterize residents' inpatient educational experience with a high degree of resolution. Leaders of other programs seeking to profile the clinical exposure of their trainees may adopt this strategy. Such clinical content mapping drives innovation in the experiential curriculum, enables comparison across practice sites, and lays the groundwork to test associations between individual clinical exposure and competency-based outcomes, which, in turn, will allow medical educators to draw conclusions regarding how clinical experience reflects clinical competency.

Incidence and Risk of Scleral-Fixated Akreos (AO60) Lens Opacification: A Case Series.

Purpose: Postoperative hydrophilic intraocular lens opacification can lead to decreased vision and may require intraocular lens exchange. This study aims to identify the incidence of scleral-fixated Akreos AO60's (Bausch + Lomb) lens opacification and risk factors for this phenomenon. Methods: This is a retrospective case series of all patients who underwent scleral-fixated Akreos AO60 lens at our institution between January 1, 2015 and December 31, 2019. The following data were recorded: age, sex, medical history, indication for Akreos AO60 implantation, laterality, ocular history, previous ocular surgical procedures, subsequent intraocular surgical procedures after the Akreos implantation, lens opacification, visual significance of opacification, and Akreos explantation. Intraoperative and postoperative complications were recorded. Main outcome measures were the overall incidence of Akreos lens opacification as well as the incidence of these eyes undergoing subsequent intraocular surgery. Results: A total of 262 eyes of 257 patients underwent Akreos lens implantation. Overall, 2% (5 of 262) developed lens opacification. Two patients had Descemet stripping automated endothelial keratoplasty (DSAEK) concurrently with Akreos implantation. One patient underwent subsequent Baerveldt glaucoma implantation and DSAEK. The fourth patient had vitrectomy with sulfur hexafluoride gas followed by DSAEK. This represents a 25% (4 of 16) opacification rate among all patients who underwent DSAEK (P ≤ .01, Fisher exact test). One patient developed opacification after undergoing 2 vitrectomies for retinal detachment in the absence of DSAEK. Conclusions: Akreos lens opacification can be visually significant and may occur after a retinal or corneal procedure that involves the use of intraocular gas or air.