👤 Jeremy Block

Endothelial to mesenchymal transition (EndMT), the transformation of endothelial cells into a mesenchymal-like state, is regulated by various factors, including transcription factors such as activator protein 1 (AP-1). While recent studies have confirmed the role of EndMT in atherosclerosis, the involvement of AP-1 in EndMT, particularly in the context of human diabetes, remains unclear. This study aimed to elucidate the role of the AP-1 transcription factor complex in EndMT associated with atherosclerosis in diabetes, utilising both an in vivo preclinical model and an ex vivo model using patient-derived serum for translational relevance. Additionally, it sought to profile gene expression changes following AP-1 inhibition in an EndMT model under high glucose conditions. Serum from patients with and without type 2 diabetes mellitus (T2DM) was used to assess EndMT in primary human aortic endothelial cells (HAECs) in the presence and absence of the AP-1 inhibitor T-5224. EndMT was evaluated through immunofluorescent staining of these cells and of aortic sections from a murine model of diabetes-associated atherosclerosis in a preclinical early intervention study. Furthermore, HAECs were used to explore the effects of AP-1 inhibition on the transcriptional signature of EndMT. Patient-derived serum induced EndMT in HAECs, which T-5224 effectively prevented, as confirmed by immunofluorescent staining. Immunofluorescent analysis of the aortic sinus also revealed that T-5224 treatment inhibited EndMT, leading to reduced atherosclerosis in Apoe This study identifies AP-1 inhibition with T-5224 as a potential therapeutic approach for EndMT resulting in reduced atherosclerosis in diabetes. The use of human serum underscores the translational relevance of these findings. Show less

Numerous studies have established lipoprotein(a) [Lp(a)] as an independent and modifiable risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve stenosis (CAVS). As such Lp(a) has become the focus of targeted drug therapy development with the goal of reducing Lp(a) serum concentrations and improving outcomes. This review aims to inform readers on the investigational agents currently in clinical trials and highlight key differences including dosing intervals and routes of administration that may facilitate uptake and retention of a particular potential medication in certain patient populations. Five investigational agents are currently undergoing various stages of clinical trials for the treatment of elevated Lp(a). Three potential therapies are small interfering RNA (siRNA) molecules and a fourth is an antisense oligonucleotide (ASO) all of which are subcutaneously injected. A fifth agent is a small molecule inhibitor that is orally administered. A sixth agent, a cholesteryl ester transfer protein (CETP) inhibitor that is primarily being studied for LDL-C reduction has shown promise for reducing Lp(a). A seventh agent based on gene-editing is currently in the developmental stage. Results have revealed notable reductions in Lp(a) with favorable tolerability and safety. Phase 3 trials will be crucial in determining the viability of lowering Lp(a) with such therapies and improving cardiovascular outcomes. Promising results indicate the potential in the near future to have medications primarily for lowering Lp(a) which has thus far eluded targeted drug therapy. As such advances stand to benefit large segments of the population living with and at risk for ASCVD, future research is vital to validate safety and efficacy in the long-term as well to understand how to optimize uptake and retention among patients with diverse circumstances. Show less

Elevated lipoprotein(a) (Lp[a]) is an independent risk factor for the development of atherosclerotic cardiovascular disease. Despite National Lipid Association guidelines recommending one-time Lp(a) screening in adults aged 18 years and older, Lp(a) testing remains underutilized. A novel gamified ambulatory curriculum educating internal medicine residents on Lp(a) was implemented at a single academic internal medicine residency program. A total of 108 residents received a Lp(a) lecture in either a gamified format using KAHOOT! or slide-based traditional format. Learning outcomes including Likert scale ratings of confidence utilizing and interpreting Lp(a) results and a 10-question knowledge assessment were collected prior to the didactic, immediately following, and after 3 months. Screening rates prior to and following intervention were assessed. The Lp(a) curriculum significantly improved resident knowledge following the lecture (8.5 out of 10 questions post-test vs 3.9 pretest, P < .0001) and at 3-month follow up (5.8 3-month vs 3.9 pretest, P = .0001). Learning outcomes in the gamified group were similar to the traditional group (8.5 post-test traditional vs 8.6 post-test gamified, P = .978; 6.3 3-month traditional vs 5.8 3-month gamified, P = .466). In the 3 months following the didactic, there was a significant increase in resident Lp(a) screening among patients who had a lipid panel assessed compared to baseline (3.11% vs 1.21%, P < .0001). Both internal medicine resident Lp(a) knowledge and confidence improved following either a gamified or traditional lecture-based didactic. Addressing gaps in resident knowledge led to a modest increase in Lp(a) screening rates in our resident clinic among patients for whom a lipid panel was assessed. Show less

A fatty acid desaturase (FADS) insertion-deletion (Indel) polymorphism (rs66698963) influences the expression of FADS1, which controls the synthesis of n-6 highly unsaturated fatty acid (HUFA) arachidonic acid (AA). The anti-inflammatory activity of the n-3 HUFA eicosapentaenoic acid (EPA) may be explained by competition with AA for proinflammatory lipid mediator synthesis. A precision medicine approach based on stratification by FADS Indel genotype could identify individuals, who benefit from greatest disease risk reduction by n-3 HUFAs. We tested the hypothesis that the FADS insertion (I) allele predicts colorectal polyp risk reduction in a secondary analysis of the randomized, placebo-controlled, 2×2 factorial seAFOod polyp prevention trial of EPA 2000 mg daily and aspirin 300 mg daily for 12 mo (ISRCTN05926847). Participant Indel genotype was determined by polymerase chain reaction (PCR) blind to trial outcomes. Colorectal polyp outcomes were included in negative binomial (polyp number) and logistic (polyp detection rate [PDR; percentage with one or more polyps]) regression models comparing each active intervention with its placebo. Presence of ≥1 Indel I allele and an interaction term (I allele × active intervention) were covariates. In 528 participants with colonoscopy and FADS Indel data, EPA use irrespective of Indel genotype, was not associated with reduced colorectal polyp number (incidence rate ratio [IRR]: 0.92; 95% confidence interval: 0.74, 1.16), mirroring original seAFOod trial analysis. However, the presence of ≥1 I allele identified EPA users with a significant reduction in colorectal polyp number (IRR: 0.50 [0.28, 0.90]), unlike aspirin, for which there was no interaction. Similar findings were obtained for the PDR. The FADS Indel I allele identified individuals, who displayed colorectal polyp prevention by EPA with a similar effect size to aspirin. Assessment of rs66698963 as a biomarker of therapeutic response to n-3 HUFAs in other populations and healthcare settings is warranted. The seAFOod polyp prevention trial and STOP-ADENOMA study were registered at International Standard Randomised Controlled Trial Number registry as ISRCTN05926847. Show less

Circulating fatty acids (FA) may be important in the psoriatic pro-inflammatory phenotype. FADS1 converts linoleic acid (LA) to arachidonic acid (AA), a precursor to potent signaling molecules. HMG-CoA reductase inhibitors (statins) increase FADS1/2 expression in vitro. Psoriasis patients (42 ± 14 years/age, 47% male) were randomized to 40 mg of atorvastatin (n = 20) or nothing (n = 10) for two weeks and plasma FA measured pre and post treatment. After treatment, LDL-C was 44% lower in the statin compared to the no-treatment group. Statins increased FADS1/2 expression, and lowered LA 12% (33% - > 29%, p<0.001) and raised AA 14% (7.7% - > 9.0%, p<0.01) with no change in the no-treatment group. In psoriasis, statins enhance AA and decrease LA, consistent with the action of enhanced FADS expression in vivo. Therapies intended to blunt the effects of AA on platelet aggregation, such as aspirin or omega-3 fatty acids, may require dose adjustment when co-administered with atorvastatin. NCT: NCT03228017. Show less

While multiple transcription factors (TFs) have been recognized to drive epithelial-mesenchymal transition (EMT) in cancer, their interdependence and context-dependent functions are poorly understood. In this study, we show that FOXQ1 and SNAI1 act as independent TFs within the EMT program with a shared ability to upregulate common EMT TFs without reciprocally impacting the expression of one another. Despite this independence, human mammary epithelial cells (HMLE) with ectopic expression of either FOXQ1 or SNAI1 share a common gene set that is enriched for a DDR2 coexpression signature. Further analysis identified DDR2 as the most upregulated receptor tyrosine kinase and a shared downstream effector of FOXQ1 and SNAI1 in triple-negative breast cancer (TNBC) cell lines. Alteration of DDR2 expression in either FOXQ1 or SNAI1 driven EMT models or in TNBC cells resulted in a profound change of cell motility without significantly impacting EMT marker expression, cell morphology, or the stem cell population. Lastly, we demonstrated that knockdown of DDR2 in the FOXQ1-driven EMT model and TNBC cell line significantly altered the global metabolic profile, including glutamine-glutamate and Aspartic acid recycling. Show less

Next-generation sequencing has dramatically increased genome-wide profiling options and conceptually initiates the possibility for personalized cancer therapy. State-of-the-art sequencing studies yield large candidate gene sets comprising dozens or hundreds of mutated genes. However, few technologies are available for the systematic downstream evaluation of these results to identify novel starting points of future cancer therapies.We improved and extended a site-specific recombination-based system for systematic analysis of the individual functions of a large number of candidate genes. This was facilitated by a novel system for the construction of isogenic constitutive and inducible gain- and loss-of-function cell lines. Additionally, we demonstrate the construction of isogenic cell lines with combinations of the traits for advanced functional in vitro analyses. In a proof-of-concept experiment, a library of 108 isogenic melanoma cell lines was constructed and 8 genes were identified that significantly reduced viability in a discovery screen and in an independent validation screen. Here, we demonstrate the broad applicability of this recombination-based method and we proved its potential to identify new drug targets via the identification of the tumor suppressor DUSP6 as potential synthetic lethal target in melanoma cell lines with BRAF V600E mutations and high DUSP6 expression. Show less

While initially sensitive to heat shock, the bovine embryo gains thermal resistance as it progresses through development so that physiological heat shock has little effect on development to the blastocyst stage by Day 5 after insemination. Here, experiments using 3' tag digital gene expression (3'DGE) and real-time PCR were conducted to determine changes in the transcriptome of morula-stage bovine embryos in response to heat shock (40 degrees C for 8 h) that could be associated with thermotolerance. Using 3'DGE, expression of 173 genes were modified by heat shock, with 94 genes upregulated by heat shock and 79 genes downregulated by heat shock. A total of 38 differentially-regulated genes were associated with the ubiquitin protein, UBC. Heat shock increased expression of one heat shock protein gene, HSPB11, and one heat shock protein binding protein, HSPBP1, tended to increase expression of HSPA1A and HSPB1, but did not affect expression of 64 other genes encoding heat shock proteins, heat shock transcription factors or proteins interacting with heat shock proteins. Moreover, heat shock increased expression of five genes associated with oxidative stress (AKR7A2, CBR1, GGH, GSTA4, and MAP2K5), decreased expression of HIF3A, but did not affect expression of 42 other genes related to free radical metabolism. Heat shock also had little effect on genes involved in embryonic development. Effects of heat shock for 2, 4 and 8 h on selected heat shock protein and antioxidant genes were also evaluated by real-time PCR. Heat shock increased steady-state amounts of mRNA for HSPA1A (P<0.05) and tended to increase expression of HSP90AA1 (P<0.07) but had no effect on expression of SOD1 or CAT. Changes in the transcriptome of the heat-shocked bovine morula indicate that the embryo is largely resistant to effects of heat shock. As a result, transcription of genes involved in thermal protection is muted and there is little disruption of gene networks involved in embryonic development. It is likely that the increased resistance of morula-stage embryos to heat shock as compared to embryos at earlier stages of development is due in part to developmental acquisition of mechanisms to prevent accumulation of denatured proteins and free radical damage. Show less

Early stages of various entities of progressive kidney diseases are commonly characterized by development of glomerular hypertrophy and albuminuria. The purpose of the present study was to identify protein biomarker candidates for these glomerular alterations. Quantitative differences in the glomerular proteomes of two unrelated murine nephropathy models in the defined stage of glomerular hypertrophy at onset of albuminuria were identified by 2-D DIGE and MALDI-TOF/TOF analysis. Investigated mouse models were (I): transgenic (tg) mice expressing a dominant negative glucose-dependent insulinotropic polypeptide receptor (GIPR(dn) ), a model of diabetes mellitus associated nephropathy and (II): growth hormone (GH)-tg mice, an established model of progressive glomerulosclerosis. In GIPR(dn) -tg mice, nine differentially abundant glomerular proteins were unambiguously identified, and eight in GH-tg mice (each versus controls). Four proteins (Annexin A4, Dihydropyrimidinase-related protein 2, Myosin regulatory light chain 2, Tropomyosin 1) displayed a congeneric differential glomerular abundance in both models, thus representing a common differential protein expression profile of glomerular hypertrophy at onset of albuminuria. The glomerular presence of these proteins was also detected in specimen of human focal and segmental glomerulosclerosis and diabetic nephropathy. Our findings suggest a pathogenetic relevance of the identified proteins in early stages of chronic kidney diseases and their potential use as diagnostic markers. Show less