Familial hypercholesterolemia class II low-density lipoprotein receptor response to statin treatment.

Low-density lipoprotein (LDL) receptor (LDLR) mutations are the primary cause of familial hypercholesterolemia (FH). Class II LDLR mutations result in a misfolded LDLR retained in the endoplasmic reticulum (ER). We have developed a model of FH class II and CRISPR-corrected induced pluripotent stem cells (iPSC) capable of replicating mutant and repaired LDLR functions. We show here that iPSC and derived hepatocyte-like cells (HLC) replicate misfolded LDLR accumulation and restoration of LDLR function in CRISPR-corrected cells. It was reported that model cells overexpressing class II LDLR mutants result in endoplasmic reticulum (ER) accumulation of immature LDLR and activation of the unfolded protein response (UPR). We show here that statins induce a similar accumulation of immature LDLR that is resolved with class II correction. We also demonstrate that, although capable of UPR induction with tunicamycin treatment, unlike overexpression models, statin-treated class II iPSC and derived HLC do not induce the common UPR markers Grp78 (also known as HSPA5) or spliced XBP1 [XBP1 (S)]. Because statins are reported to inhibit UPR, we utilized lipoprotein-deficient serum (LPDS) medium, but still did not detect UPR induction at the Grp78 and XBP1 (S) levels. Our study demonstrates the recapitulation of mutant and corrected class II LDLR function and suggests that overexpression models may not accurately predict statin-mediated class II protein biology.

Investigation of RNA Editing Sites within Bound Regions of RNA-Binding Proteins.

Studies in epitranscriptomics indicate that RNA is modified by a variety of enzymes. Among these RNA modifications, adenosine to inosine (A-to-I) RNA editing occurs frequently in the mammalian transcriptome. These RNA editing sites can be detected directly from RNA sequencing (RNA-seq) data by examining nucleotide changes from adenosine (A) to guanine (G), which substitutes for inosine (I). However, a careful investigation of such nucleotide changes must be conducted to distinguish sequencing errors and genomic mutations from the genuine editing sites. Building upon our recent introduction of an easy-to-use bioinformatics tool, RNA Editor, to detect RNA editing events from RNA-seq data, we examined the extent by which RNA editing events affect the binding of RNA-binding proteins (RBP). Through employing bioinformatic techniques, we uncovered that RNA editing sites occur frequently in RBP-bound regions. Moreover, the presence of RNA editing sites are more frequent when RNA editing islands were examined, which are regions in which RNA editing sites are present in clusters. When the binding of one RBP, human antigen R [HuR; encoded by ELAV-like protein 1 (ELAV1)], was quantified experimentally, its binding was reduced upon silencing of the RNA editing enzyme adenosine deaminases acting on RNA (ADAR) compared to the control-suggesting that the presence of RNA editing islands influence HuR binding to its target regions. These data indicate RNA editing as an important mediator of RBP-RNA interactions-a mechanism which likely constitutes an additional mode of post-transcription gene regulation in biological systems.

E2f1 deletion attenuates infarct-induced ventricular remodeling without affecting O-GlcNAcylation.

Several post-translational modifications figure prominently in ventricular remodeling. The beta-O-linkage of N-acetylglucosamine (O-GlcNAc) to proteins has emerged as an important signal in the cardiovascular system. Although there are limited insights about the regulation of the biosynthetic pathway that gives rise to the O-GlcNAc post-translational modification, much remains to be elucidated regarding the enzymes, such as O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), which regulate the presence/absence of O-GlcNAcylation. Recently, we showed that the transcription factor, E2F1, could negatively regulate OGT and OGA expression in vitro. The present study sought to determine whether E2f1 deletion would improve post-infarct ventricular function by de-repressing expression of OGT and OGA. Male and female mice were subjected to non-reperfused myocardial infarction (MI) and followed for 1 or 4 week. MI significantly increased E2F1 expression. Deletion of E2f1 alone was not sufficient to alter OGT or OGA expression in a naïve setting. Cardiac dysfunction was significantly attenuated at 1-week post-MI in E2f1-ablated mice. During chronic heart failure, E2f1 deletion also attenuated cardiac dysfunction. Despite the improvement in function, OGT and OGA expression was not normalized and protein O-GlcNAcyltion was not changed at 1-week post-MI. OGA expression was significantly upregulated at 4-week post-MI but overall protein O-GlcNAcylation was not changed. As an alternative explanation, we also performed guided transcriptional profiling of predicted targets of E2F1, which indicated potential differences in cardiac metabolism, angiogenesis, and apoptosis. E2f1 ablation increased heart size and preserved remote zone capillary density at 1-week post-MI. During chronic heart failure, cardiomyocytes in the remote zone of E2f1-deleted hearts were larger than wildtype. These data indicate that, overall, E2f1 exerts a deleterious effect on ventricular remodeling. Thus, E2f1 deletion improves ventricular remodeling with limited impact on enzymes regulating O-GlcNAcylation.

Videodermoscopy: a useful tool for diagnosing congenital triangular alopecia.

Congenital triangular alopecia, despite its name, usually presents in children between 3 and 6 years of age, but adult patients have been reported. It is not uncommon for triangular alopecia to be misdiagnosed as alopecia areata and treated for such. This is especially true when a lesion of triangular alopecia presents in an area of the scalp other than the typical fronto-temporal hairline or later in adulthood. Videodermoscopy may serve as a useful tool to perform the right diagnosis as it can highlight signs not seen by the unaided eye and may be able to spare the patient from a biopsy.

Cutaneous epithelioid hemangioendothelioma.

Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor of endothelial cell origin. We describe an EHE arising on the plantar surface of the foot that was treated as verruca vulgaris for several years before a biopsy showed EHE. We discuss the clinical and histopathologic differential diagnoses for these tumors and review additional cases in which EHE has been mistaken for benign entities clinically.

Etanercept for the treatment of psoriasis in the elderly.

This study's objective was to analyze the effect of etanercept on Psoriasis Area and Severity Index (PASI) 50, PASI 75, and Dermatology Life Quality Index in geriatric and nongeriatric populations. We conducted a post hoc analysis of two large phase III randomized placebo trials of etanercept. There were no statistically significant differences between the elderly and young with regard to the number of patients reaching a PASI 50 or PASI 75 at any of the 3 dosing regimens. Baseline Dermatology Life Quality Index scores were not statistically significant between both groups and both the elderly and young had similar changes in Dermatology Life Quality Index with therapy. A limitation of the study was the small number of patients in the elderly group. In conclusion, psoriasis and its treatment has a similar impact on quality of life in the elderly as it does in the young.

Eccrine porocarcinoma arising in two African American patients: distinct presentations both treated with Mohs micrographic surgery.

Abstract Background Eccrine porocarcinoma (EPC) is a rare, malignant adnexal tumor that has been reported only three times specifically in African American individuals. Diagnosis and treatment of EPC is important, given the 20% local recurrence and regional metastatic rates. However, no standard of care has been developed to guide effective treatment. Methods We report two distinct clinical presentations of EPC, both in African Americans, and discuss a review of the literature. Results The neoplasms were successfully removed from both patients by Mohs micrographic surgery. Conclusions These two cases illustrate that EPC can have a variety of presentations and can occur in African Americans. Although there is no standard of care for treating EPC, Mohs is becoming a common technique of removing these lesions.