An enzymatic Alder-ene reaction.

An ongoing challenge in chemical research is to design catalysts that select the outcomes of the reactions of complex molecules. Chemists rely on organocatalysts or transition metal catalysts to control stereoselectivity, regioselectivity and periselectivity (selectivity among possible pericyclic reactions). Nature achieves these types of selectivity with a variety of enzymes such as the recently discovered pericyclases-a family of enzymes that catalyse pericyclic reactions1. Most characterized enzymatic pericyclic reactions have been cycloadditions, and it has been difficult to rationalize how the observed selectivities are achieved2-13. Here we report the discovery of two homologous groups of pericyclases that catalyse distinct reactions: one group catalyses an Alder-ene reaction that was, to our knowledge, previously unknown in biology; the second catalyses a stereoselective hetero-Diels-Alder reaction. Guided by computational studies, we have rationalized the observed differences in reactivities and designed mutant enzymes that reverse periselectivities from Alder-ene to hetero-Diels-Alder and vice versa. A combination of in vitro biochemical characterizations, computational studies, enzyme co-crystal structures, and mutational studies illustrate how high regioselectivity and periselectivity are achieved in nearly identical active sites.

HuR-dependent expression of Wisp1 is necessary for TGFß-induced cardiac myofibroblast activity.

Cardiac fibrosis is regulated by the activation and phenotypic switching of quiescent cardiac fibroblasts to active myofibroblasts, which have extracellular matrix (ECM) remodeling and contractile functions which play a central role in cardiac remodeling in response to injury. Here, we show that expression and activity of the RNA binding protein HuR is increased in cardiac fibroblasts upon transformation to an active myofibroblast. Pharmacological inhibition of HuR significantly blunts the TGFß-dependent increase in ECM remodeling genes, total collagen secretion, in vitro scratch closure, and collagen gel contraction in isolated primary cardiac fibroblasts, suggesting a suppression of TGFß-induced myofibroblast activation upon HuR inhibition. We identified twenty-four mRNA transcripts that were enriched for HuR binding following TGFß treatment via photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP). Eleven of these HuR-bound mRNAs also showed significant co-expression correlation with HuR, αSMA, and periostin in primary fibroblasts isolated from the ischemic-zone of infarcted mouse hearts. Of these, WNT1-inducible signaling pathway protein-1 (Wisp1; Ccn4), was the most significantly associated with HuR expression in fibroblasts. Accordingly, we found Wisp1 expression to be increased in cardiac fibroblasts isolated from the ischemic-zone of mouse hearts following ischemia/reperfusion, and confirmed Wisp1 expression to be HuR-dependent in isolated fibroblasts. Finally, addition of exogenous recombinant Wisp1 partially rescued myofibroblast-induced collagen gel contraction following HuR inhibition, demonstrating that HuR-dependent Wisp1 expression plays a functional role in HuR-dependent MF activity downstream of TGFß. In conclusion, HuR activity is necessary for the functional activation of primary cardiac fibroblasts in response to TGFß, in part through post-transcriptional regulation of Wisp1.

Catalyst-Controlled Annulations of Strained Cyclic Allenes with π-Allylpalladium Complexes.

Strained cyclic allenes are a class of in situ-generated fleeting intermediates that, despite being discovered more than 50 years ago, has received significantly less attention from the synthetic community compared to related strained intermediates. Examples of trapping strained cyclic allenes that involve transition metal catalysis are especially rare. We report the first annulations of highly reactive cyclic allenes with in situ-generated π-allylpalladium species. By varying the ligand employed, either of two isomeric polycyclic scaffolds can be obtained with high selectivity. The products are heterocyclic and sp3-rich and bear two or three new stereocenters. This study should encourage the further development of fragment couplings that rely on transition metal catalysis and strained cyclic allenes for the rapid assembly of complex scaffolds.

Changes in opioid prescribing in veterans with headache during the COVID-19 pandemic: A regression discontinuity in time analysis.

OBJECTIVE: To determine changes in opioid prescribing among veterans with headaches during the coronavirus disease of 2019 (COVID-19) pandemic by comparing the stay-at-home phase (March 15 to May 30, 2020) and the reopening phase (May 31 to December 31, 2020). BACKGROUND: Opioid prescribing for chronic pain has declined substantially since 2016; however, changes in opioid prescribing during the COVID-19 pandemic among veterans with headaches remain unknown. METHODS: This retrospective cohort study utilized regression discontinuity in time and difference-in-differences design to analyze veterans aged ≥18 years with a previous diagnosis of headache disorders and an outpatient visit to the Veterans Health Administration (VHA) during the study period. We measured the weekly number of opioid prescriptions, the number of days supplied, the daily dose in morphine milligram equivalents (MMEs), and the number of prescriptions with ≥50 morphine equivalent daily doses (MEDD). RESULTS: A total of 81,376 veterans were analyzed with 589,950 opioid prescriptions. The mean (SD) age was 51.6 (13.5) years, 57,242 (70.3%) were male, and 53,464 (65.7%) were White. During the pre-pandemic period, 323.6 opioid prescriptions (interquartile range 292.1-325.8) were dispensed weekly, with an median (IQR) of 24.1 (24.0-24.4) days supplied and 31.8 (31.2-32.5) MMEs. Transition to stay-at-home was associated with a 7.7% decrease in the number of prescriptions (incidence rate ratio [IRR] 1.077, 95% confidence interval [CI] 0.866-0.984) and a 9.8% increase in days supplied (IRR 1.098, 95% CI 1.078-1.119). Similar trends were observed during the reopening period. Subgroup analysis among veterans on long-term opioid therapy also revealed 1.7% and 1.4% increases in days supplied during the stay-at-home (IRR 1.017, 95% CI 1.009-1.025) and reopening phase (IRR 1.014, 95% CI 1.007-1.021); however, changes in the total number of prescriptions, MME/day, or the number of prescriptions >50 MEDD were insignificant. CONCLUSION: Prescription opioid access was maintained for veterans within VHA during the pandemic. The de-escalation of opioid prescribing observed prior to the pandemic was not seen in our study.

Trajectory of blood pressure after initiating anti-calcitonin gene-related peptide treatment of migraine: a target trial emulation from the veterans health administration.

BACKGROUND: Calcitonin gene-related peptide (CGRP) is involved in migraine pathophysiology and blood pressure regulation. Although clinical trials have established the cardio-cerebrovascular safety profile of anti-CGRP treatment, limited high-quality real-world evidence exists on its long-term effects on blood pressure (BP). To address this gap, we examined the safety of anti-CGRP treatment on BP in patients with migraine headache in the Veterans Health Administration (VHA). METHODS: We emulated a target trial of patients who initiated anti-CGRP treatment or topiramate for migraine prevention between May 17th, 2018 and February 28th, 2023. We calculated stabilized inverse probability weights to balance between groups and then used weighted linear mixed-effect models to estimate the systolic and diastolic BP changes over the study period. For patients without hypertension at baseline, we estimated the cumulative incidence of hypertension using Kaplan-Meier curve. We also used weight mixed-effect Poisson model to estimate the number of antihypertension medications for patients with hypertension at baseline. RESULTS: This analysis included 69,589 patients and 554,437 blood pressure readings. of these, 18,880 patients received anti-CGRP treatment, and they were more likely to be women, have a chronic migraine diagnosis and higher healthcare utilization than those received topiramate. Among patients without hypertension at baseline, we found no significant differences in systolic BP changes over the four-year follow-up between anti-CGRP (slope [standard error, SE] = 0.48[0.06]) and topiramate treated patients (slope[SE] = 0.39[0.04]). The incidence of hypertension was similar for anti-CGRP and topiramate group (4.4 vs 4.3 per 100 person-years). Among patients with hypertension at baseline who initiated anti-CGRP treatment, we found a small but persistent effect on exacerbating hypertension during the first four years of treatment, as evidenced by a significant annual 3.7% increase in the number of antihypertensive medications prescribed (RR = 1.037, 95%CI 1.025-1.048). CONCLUSIONS: Our findings suggest that anti-CGRP treatment is safe regarding blood pressure in patients without hypertension. However, for those with baseline hypertension, anti-CGRP treatment resulted in a small but persistent increase in the number of antihypertensives, indicating an exacerbation of hypertension. Future studies are needed to evaluate the cardio-cerebrovascular safety of anti-CGRP treatment beyond the first four years.

Abemaciclib in patients with p16ink4A-deficient mesothelioma (MiST2): a single-arm, open-label, phase 2 trial.

BACKGROUND: Genetically stratified therapy for malignant mesothelioma is unavailable. Mesotheliomas frequently harbour loss of the chromosome 9p21.3 locus (CDKN2A-MTAP), which is associated with shorter overall survival due to loss of the tumour suppressor p16ink4A, an endogenous suppressor of cyclin-dependent kinase (CDK)4 and CDK6. Genetic restoration of p16ink4A suppresses mesothelioma in preclinical models, underpinning the rationale for targeting CDK4 and CDK6 in p16ink4A-negative mesothelioma. We developed a multicentre, stratified, phase 2 trial to test this hypothesis. METHODS: The MiST2 study was a single-arm, open-label, phase 2 clinical trial done two UK centres. Patients older than 18 years with any histologically confirmed subtype of mesothelioma (pleural or peritoneal) with radiological progression after at least one course of platinum-based chemotherapy were molecularly screened by immunohistochemistry for p16ink4A. Patients with p16ink4A-negative mesothelioma were eligible for inclusion in the study. Patients were required to have measurable disease by modified Response Evaluation Criteria in Solid Tumours version 1.1 for malignant mesothelioma, a predicted life expectancy of at least 12 weeks, and an Eastern Cooperative Oncology Group performance status score of 0-1. Patients received oral abemaciclib 200 mg twice daily, administered in 28-day cycles for 24 weeks. The primary endpoint was the disease control rate (patients with complete responses, partial responses, or stable disease) at 12 weeks. The null hypothesis could be rejected if at least 11 patients had disease control. The efficacy and safety populations were defined as all patients who received at least one dose of the study drug. The study is registered with ClinicalTrials.gov, NCT03654833, and is ongoing (but MiST2 is now closed). FINDINGS: Between Sept 31, 2019, and March 2, 2020, 27 eligible patients consented to molecular screening. The median follow-up was 18·4 weeks (IQR 6·7-23·9). One patient was excluded before treatment because of a serious adverse event before study drug allocation. 26 (100%) of 26 treated patients were p16ink4A deficient and received at least one dose of abemaciclib. Disease control at 12 weeks was reported in 14 (54%) of 26 patients (95% CI 36-71). Grade 3 or worse treatment-related adverse events (of any cause) occurred in eight (27%) of 26 patients (diarrhoea, dyspnoea, thrombocytopenia, vomiting, urinary tract infection, increased alanine aminotransferase, ascites, chest infection or suspected chest infection, neutropenic sepsis, alopecia, blood clot left calf, fall [broken neck and collar bone], haemoptysis, lower respiratory tract infection, and pulmonary embolism). Grade 3 or worse treatment-related adverse events occurred in three (12%) of 26 patients (diarrhoea, thrombocytopenia, vomiting, increased alanine aminotransferase, and pulmonary embolism). Serious adverse events occurred in six (23%) of 26 patients, leading to treatment discontinuation in one (4%) patient (diarrhoea, urinary tract infection, chest infection, neutropenic sepsis, fall [broken neck and collar bone], haemoptysis, lower respiratory tract infection, and pulmonary embolism). One patient had a serious adverse event related to abemaciclib (diarrhoea). One (4%) of 26 patients died from an adverse event (neutropenic sepsis). INTERPRETATION: This study met its primary endpoint, showing promising clinical activity of abemaciclib in patients with p16ink4A-negative mesothelioma who were previously treated with chemotherapy, and warrants its further investigation in a randomised study as a targeted stratified therapy. FUNDING: University of Leicester, Asthma UK and British Lung Foundation Partnership, and the Victor Dahdaleh Foundation.

Total Synthesis of (-)-Strictosidine and Interception of Aryne Natural Product Derivatives "Strictosidyne" and "Strictosamidyne".

Monoterpene indole alkaloids are a large class of natural products derived from a single biosynthetic precursor, strictosidine. We describe a synthetic approach to strictosidine that relies on a key facially selective Diels-Alder reaction between a glucosyl-modified alkene and an enal to set the C15-C20-C21 stereotriad. DFT calculations were used to examine the origin of stereoselectivity in this key step, wherein two of 16 possible isomers are predominantly formed. These calculations suggest the presence of a glucosyl unit, also inherent in the strictosidine structure, guides diastereoselectivity, with the reactive conformation of the vinyl glycoside dienophile being controlled by an exo-anomeric effect. (-)-Strictosidine was subsequently accessed using late-stage synthetic manipulations and an enzymatic Pictet-Spengler reaction. Several new natural product analogs were also accessed, including precursors to two unusual aryne natural product derivatives termed "strictosidyne" and "strictosamidyne". These studies provide a strategy for accessing glycosylic natural products and a new platform to access monoterpene indole alkaloids and their derivatives.

Adipocyte-specific deletion of HuR induces spontaneous cardiac hypertrophy and fibrosis.

Adipose tissue homeostasis plays a central role in cardiovascular physiology, and the presence of thermogenically active brown adipose tissue (BAT) has recently been associated with cardiometabolic health. We have previously shown that adipose tissue-specific deletion of HuR (Adipo-HuR-/-) reduces BAT-mediated adaptive thermogenesis, and the goal of this work was to identify the cardiovascular impacts of Adipo-HuR-/-. We found that Adipo-HuR-/- mice exhibit a hypercontractile phenotype that is accompanied by increased left ventricle wall thickness and hypertrophic gene expression. Furthermore, hearts from Adipo-HuR-/- mice display increased fibrosis via picrosirius red staining and periostin expression. To identify underlying mechanisms, we applied both RNA-seq and weighted gene coexpression network analysis (WGCNA) across both cardiac and adipose tissue to define HuR-dependent changes in gene expression as well as significant relationships between adipose tissue gene expression and cardiac fibrosis. RNA-seq results demonstrated a significant increase in proinflammatory gene expression in both cardiac and subcutaneous white adipose tissue (scWAT) from Adipo-HuR-/- mice that is accompanied by an increase in serum levels of both TNF-α and IL-6. In addition to inflammation-related genes, WGCNA identified a significant enrichment in extracellular vesicle-mediated transport and exosome-associated genes in scWAT, whose expression most significantly associated with the degree of cardiac fibrosis observed in Adipo-HuR-/- mice, implicating these processes as a likely adipose-to-cardiac paracrine mechanism. These results are significant in that they demonstrate the spontaneous onset of cardiovascular pathology in an adipose tissue-specific gene deletion model and contribute to our understanding of how disruptions in adipose tissue homeostasis may mediate cardiovascular disease.NEW & NOTEWORTHY The presence of functional brown adipose tissue in humans is known to be associated with cardiovascular health. Here, we show that adipocyte-specific deletion of the RNA binding protein HuR, which we have previously shown to reduce BAT-mediated thermogenesis, is sufficient to mediate a spontaneous development of cardiac hypertrophy and fibrosis. These results may have implications on the mechanisms by which BAT function and adipose tissue homeostasis directly mediate cardiovascular disease.

Antibody to Poly-N-acetyl glucosamine provides protection against intracellular pathogens: Mechanism of action and validation in horse foals challenged with Rhodococcus equi.

Immune correlates of protection against intracellular bacterial pathogens are largely thought to be cell-mediated, although a reasonable amount of data supports a role for antibody-mediated protection. To define a role for antibody-mediated immunity against an intracellular pathogen, Rhodococcus equi, that causes granulomatous pneumonia in horse foals, we devised and tested an experimental system relying solely on antibody-mediated protection against this host-specific etiologic agent. Immunity was induced by vaccinating pregnant mares 6 and 3 weeks prior to predicted parturition with a conjugate vaccine targeting the highly conserved microbial surface polysaccharide, poly-N-acetyl glucosamine (PNAG). We ascertained antibody was transferred to foals via colostrum, the only means for foals to acquire maternal antibody. Horses lack transplacental antibody transfer. Next, a randomized, controlled, blinded challenge was conducted by inoculating at ~4 weeks of age ~10(6) cfu of R. equi via intrabronchial challenge. Eleven of 12 (91%) foals born to immune mares did not develop clinical R. equi pneumonia, whereas 6 of 7 (86%) foals born to unvaccinated controls developed pneumonia (P = 0.0017). In a confirmatory passive immunization study, infusion of PNAG-hyperimmune plasma protected 100% of 5 foals against R. equi pneumonia whereas all 4 recipients of normal horse plasma developed clinical disease (P = 0.0079). Antibodies to PNAG mediated killing of extracellular and intracellular R. equi and other intracellular pathogens. Killing of intracellular organisms depended on antibody recognition of surface expression of PNAG on infected cells, along with complement deposition and PMN-assisted lysis of infected macrophages. Peripheral blood mononuclear cells from immune and protected foals released higher levels of interferon-γ in response to PNAG compared to controls, indicating vaccination also induced an antibody-dependent cellular release of this critical immune cytokine. Overall, antibody-mediated opsonic killing and interferon-γ release in response to PNAG may protect against diseases caused by intracellular bacterial pathogens.

Mechanisms linking adipose tissue inflammation to cardiac hypertrophy and fibrosis.

Adipose tissue is classically recognized as the primary site of lipid storage, but in recent years has garnered appreciation for its broad role as an endocrine organ comprising multiple cell types whose collective secretome, termed as adipokines, is highly interdependent on metabolic homeostasis and inflammatory state. Anatomical location (e.g. visceral, subcutaneous, epicardial etc) and cellular composition of adipose tissue (e.g. white, beige, and brown adipocytes, macrophages etc.) also plays a critical role in determining its response to metabolic state, the resulting secretome, and its potential impact on remote tissues. Compared with other tissues, the heart has an extremely high and constant demand for energy generation, of which most is derived from oxidation of fatty acids. Availability of this fatty acid fuel source is dependent on adipose tissue, but evidence is mounting that adipose tissue plays a much broader role in cardiovascular physiology. In this review, we discuss the impact of the brown, subcutaneous, and visceral white, perivascular (PVAT), and epicardial adipose tissue (EAT) secretome on the development and progression of cardiovascular disease (CVD), with a particular focus on cardiac hypertrophy and fibrosis.

Arynes and Cyclic Alkynes as Synthetic Building Blocks for Stereodefined Quaternary Centers.

We report a facile method to synthesize stereodefined quaternary centers from reactions of arynes and related strained intermediates using ß-ketoester-derived substrates. The conversion of ß-ketoesters to chiral enamines is followed by reaction with in situ generated strained arynes or cyclic alkynes. Hydrolytic workup provides the arylated or alkenylated products in enantiomeric excesses as high as 96%. We also describe the one-pot conversion of a ß-ketoester substrate to the corresponding enantioenriched α-arylated product. Computations show how chirality is transferred from the N-bound chiral auxiliary to the final products. These are the first theoretical studies of aryne trapping by chiral nucleophiles to set new stereocenters. Our approach provides a solution to the challenging problem of stereoselective ß-ketoester arylation/alkenylation, with formation of a quaternary center.

Synthesis and PGE2 inhibitory activity of novel diarylheptanoids.

Prostaglandin E2 (PGE2) is a lipid mediator of inflammation and its inhibition has become a popular drug target due to its harmful physiological roles. Diarylheptanoids are one class of compounds that have shown successful inhibition of PGE2. This paper reports the synthesis and PGE2 inhibitory activity of a series of analogues of a naturally occurring diarylheptanoid. The most efficacious compounds were examined for dose-dependent PGE2 inhibition. Among several promising compounds, the lead candidate exhibited an IC50 value of 0.56 ng/µL or 1.7 µM with no detectable toxicity at the highest dose of 10 ng/µL.

The stress-induced heat shock protein 70.3 expression is regulated by a dual-component mechanism involving alternative polyadenylation and HuR.

Heat shock protein 70.3 (Hsp70.3) expression increases in response to cellular stress and plays a cytoprotective role. We have previously shown that Hsp70.3 expression is controlled through coordinated post-transcriptional regulation by miRNAs and alternative polyadenylation (APA), and APA-mediated shortening of the Hsp70.3 3'-UTR facilitates increased protein expression. A stress-induced increase in Hsp70.3 mRNA and protein expression is accompanied by alternative polyadenylation (APA)-mediated truncation of the 3'UTR of the Hsp70.3 mRNA transcript. However, the role that APA plays in stress-induced expression of Hsp70.3 remains unclear. Our results show that APA-mediated truncation of the Hsp70.3 3'UTR increases protein expression through enhanced polyribosome loading. Additionally, we demonstrate that the RNA binding protein HuR, which has been previously shown to play a role in mediating APA, is necessary for heat shock mediated increase in Hsp70.3 mRNA and protein. However, it is somewhat surprising to note that HuR does not play a role in APA of the Hsp70.3 mRNA, and these two regulatory events appear to be mutually exclusive regulators of Hsp70.3 expression. These results not only provide important insight to the regulation of stress response genes following heat shock, but also contribute an enhanced understanding of how alternative polyadenylation contributes to gene regulation.

Intestinal brush-border Na+/H+ exchanger-3 drives H+-coupled iron absorption in the mouse.

Divalent metal-ion transporter-1 (DMT1), the principal mechanism by which nonheme iron is taken up at the intestinal brush border, is energized by the H(+)-electrochemical potential gradient. The provenance of the H(+) gradient in vivo is unknown, so we have explored a role for brush-border Na(+)/H(+) exchanger (NHE) isoforms by examining iron homeostasis and intestinal iron handling in mice lacking NHE2 or NHE3. We observed modestly depleted liver iron stores in NHE2-null (NHE2(-/-)) mice stressed on a low-iron diet but no change in hematological or blood iron variables or the expression of genes associated with iron metabolism compared with wild-type mice. Ablation of NHE3 strongly depleted liver iron stores, regardless of diet. We observed decreases in blood iron variables but no overt anemia in NHE3-null (NHE3(-/-)) mice on a low-iron diet. Intestinal expression of DMT1, the apical surface ferrireductase cytochrome b reductase-1, and the basolateral iron exporter ferroportin was upregulated in NHE3(-/-) mice, and expression of liver Hamp1 (hepcidin) was suppressed compared with wild-type mice. Absorption of (59)Fe from an oral dose was substantially impaired in NHE3(-/-) compared with wild-type mice. Our data point to an important role for NHE3 in generating the H(+) gradient that drives DMT1-mediated iron uptake at the intestinal brush border.

Nickel-Catalyzed Esterification of Aliphatic Amides.

Recent studies have demonstrated that amides can be used in nickel-catalyzed reactions that lead to cleavage of the amide C-N bond, with formation of a C-C or C-heteroatom bond. However, the general scope of these methodologies has been restricted to amides where the carbonyl is directly attached to an arene or heteroarene. We now report the nickel-catalyzed esterification of amides derived from aliphatic carboxylic acids. The transformation requires only a slight excess of the alcohol nucleophile and is tolerant of heterocycles, substrates with epimerizable stereocenters, and sterically congested coupling partners. Moreover, a series of amide competition experiments establish selectivity principles that will aid future synthetic design. These studies overcome a critical limitation of current Ni-catalyzed amide couplings and are expected to further stimulate the use of amides as synthetic building blocks in C-N bond cleavage processes.

Intestinal DMT1 is critical for iron absorption in the mouse but is not required for the absorption of copper or manganese.

Divalent metal-ion transporter-1 (DMT1) is a widely expressed iron-preferring membrane-transport protein that serves a critical role in erythroid iron utilization. We have investigated its role in intestinal metal absorption by studying a mouse model lacking intestinal DMT1 (i.e., DMT1(int/int)). DMT1(int/int) mice exhibited a profound hypochromic-microcytic anemia, splenomegaly, and cardiomegaly. That the anemia was due to iron deficiency was demonstrated by the following observations in DMT1(int/int) mice: 1) blood iron and tissue nonheme-iron stores were depleted; 2) mRNA expression of liver hepcidin (Hamp1) was depressed; and 3) intraperitoneal iron injection corrected the anemia, and reversed the changes in blood iron, nonheme-iron stores, and hepcidin expression levels. We observed decreased total iron content in multiple tissues from DMT1(int/int) mice compared with DMT1(+/+) mice but no meaningful change in copper, manganese, or zinc. DMT1(int/int) mice absorbed (64)Cu and (54)Mn from an intragastric dose to the same extent as did DMT1(+/+) mice but the absorption of (59)Fe was virtually abolished in DMT1(int/int) mice. This study reveals a critical function for DMT1 in intestinal nonheme-iron absorption for normal growth and development. Further, this work demonstrates that intestinal DMT1 is not required for the intestinal transport of copper, manganese, or zinc.

HuR inhibition reduces post-ischemic cardiac remodeling by dampening acute inflammatory gene expression and the innate immune response.

Myocardial ischemia/reperfusion (I/R) injury and the resulting cardiac remodeling is a common cause of heart failure. The RNA binding protein Human Antigen R (HuR) has been previously shown to reduce cardiac remodeling following both I/R and cardiac pressure overload, but the full extent of the HuR-dependent mechanisms within cells of the myocardium have yet to be elucidated. In this study, we applied a novel small molecule inhibitor of HuR to define the functional role of HuR in the acute response to I/R injury and gain a better understanding of the HuR-dependent mechanisms during post-ischemic myocardial remodeling. Our results show an early (two hours post-I/R) increase in HuR activity that is necessary for early inflammatory gene expression by cardiomyocytes in response to I/R. Surprisingly, despite the reductions in early inflammatory gene expression at two hours post-I/R, HuR inhibition has no effect on initial infarct size at 24-hours post-I/R. However, in agreement with previously published work, we do see a reduction in pathological remodeling and preserved cardiac function at two weeks post-I/R upon HuR inhibition. RNA-sequencing analysis of neonatal rat ventricular myocytes (NRVMs) at two hours post-LPS treatment to model damage associated molecular pattern (DAMP)-mediated activation of toll like receptors (TLRs) demonstrates a broad HuR-dependent regulation of pro-inflammatory chemokine and cytokine gene expression in cardiomyocytes. We show that conditioned media from NRVMs pre-treated with HuR inhibitor loses the ability to induce inflammatory gene expression in bone marrow derived macrophages (BMDMs) compared to NRVMs treated with LPS alone. Functionally, HuR inhibition in NRVMs also reduces their ability to induce endocrine migration of peripheral blood monocytes in vitro and reduces post-ischemic macrophage infiltration to the heart in vivo. In summary, these results suggest a HuR-dependent expression of pro-inflammatory gene expression by cardiomyocytes that leads to subsequent monocyte recruitment and macrophage activation in the post-ischemic myocardium.

Calcitonin Gene-Related Peptide Monoclonal Antibodies and Risk of SARS-CoV-2 Infection and Severe COVID-19 Outcomes Among Veterans With Migraine Disorder.

Importance: Calcitonin gene-related peptide (CGRP), a neuropeptide involved in migraine pathophysiology, is also a key neuroimmune modulator. CGRP antagonists may help mitigate the hyperinflammatory response observed in patients with COVID-19; however, findings from the literature are contradictory, and to date, no study has investigated the safety and effectiveness of CGRP antagonists against COVID-19. Objective: To evaluate the association between CGRP monoclonal antibody (mAb) treatment and risk of SARS-CoV-2 infection and sequela hospitalization, requiring supplemental oxygen, use of mechanical ventilation, or death. Design, Setting, and Participants: This retrospective cohort study analyzed the electronic health records of US veterans aged 18 to 65 years who were diagnosed with migraine disorder and were at risk of COVID-19 between January 20, 2020, and May 19, 2022. Exposure: Initiation of CGRP mAbs. Main Outcomes and Measures: The main outcome was cumulative incidence of SARS-CoV-2 infection. Odds of 30-day hospitalization, requiring supplemental oxygen, use of mechanical ventilation, or death were secondary outcomes. Results: Among 8 178 652 eligible person-trials (354 294 veterans), 9992 (mean [SD] age, 46.0 [9.5] years; 53.9% male) initiated CGRP mAbs and 8 168 660 (mean [SD] age, 46.6 [10.2] years; 65.7% male) did not initiate CGRP mAbs. Over a 28-month follow-up period, 1247 initiators (12.5%) and 780 575 noninitiators (9.6%) tested positive for SARS-CoV-2. After censoring persons who deviated from treatment, the incidence was 7.4 cases per 1000 person-months among initiators and 6.9 per 1000 person-months among noninitiators. The inverse probability-weighted observational analogs of intention-to-treat and per-protocol hazard ratios were 0.95 (95% CI, 0.89-1.01) and 0.93 (95% CI, 0.86-1.02), respectively. No significant differences in the likelihood of hospitalization (odds ratio [OR], 0.93; 95% CI, 0.62-1.41), requiring supplemental oxygen (OR, 0.77; 95% CI, 0.45-1.30), use of mechanical ventilation (OR, 0.85; 95% CI, 0.26-2.84), or death (OR, 0.67; 95% CI, 0.09-5.23) were observed between CGRP mAb initiators and noninitiators who tested positive for SARS-CoV-2. Conclusions and Relevance: In this cohort study, CGRP mAb treatment was not associated with positive SARS-CoV-2 test results or risk of severe COVID-19 outcomes, suggesting that CGRP mAbs may be used for migraine prevention during the COVID-19 pandemic. Given the few events of requiring supplemental oxygen, use of mechanical ventilation, and death, replication analysis in a larger sample of patients later in the course of disease is warranted.

Leveraging Fleeting Strained Intermediates to Access Complex Scaffolds.

Arynes, strained cyclic alkynes, and strained cyclic allenes were validated as plausible intermediates in the 1950s and 1960s. Despite initially being considered mere scientific curiosities, these transient and highly reactive species have now become valuable synthetic building blocks. This Perspective highlights recent advances in the field that have allowed access to structural and stereochemical complexity, including recent breakthroughs in asymmetric catalysis.

Development of a congestive heart failure protocol in a rehabilitation setting.

A number of patients in a rehabilitation setting were being transferred to acute-care facilities with a diagnosis of congestive heart failure (CHF). A transfer penalty was charged to the rehabilitation facility based on each patient's length of stay. A multidisciplinary team was assembled with physician support to address the problem. The team's goal was to develop a CHF protocol with guidelines that would allow for more frequent nursing assessments and reporting to physicians. The protocol interventions were initiated consistently and monitored on each shift. These interventions allowed for more timely assessment and treatment of patients with signs and symptoms of CHF. As a result, the number of patients being transferred to acute-care hospitals has decreased, allowing patients to complete their rehabilitation process without interruption. The decreased number of patients being transferred to the acute-care setting has resulted in fewer transfer penalties for the rehabilitation facility.