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Small molecules that target the spliceosome SF3B complex are potent inhibitors of cancer cell growth. The compounds affect an early stage of spliceosome assembly when U2 snRNP first engages the branch point sequence of an intron. Employing an inactive herboxidiene analog (iHB) as a competitor, we investigated factors that influence inhibitor interactions with SF3B to interfere with pre-mRNA splicing in vitro. Order-of-addition experiments show that inhibitor interactions are long lasting and affected by both temperature and the presence of ATP. Our data are also consistent with the model that not all SF3B conformations observed in structural studies are conducive to productive inhibitor interactions. Notably, SF3B inhibitors do not impact an ATP-dependent rearrangement in U2 snRNP that exposes the branch binding sequence for base pairing. We also report extended structure-activity relationship analysis of the splicing inhibitor herboxidiene. We identified features of the tetrahydropyran ring that mediate its interactions with SF3B and its ability to interfere with splicing. In the context of recent structures of SF3B bound to inhibitor, our results lead us to extend the model for early spliceosome assembly and inhibitor mechanism. We postulate that interactions between a carboxylic acid substituent of herboxidiene and positively charged SF3B1 side chains in the inhibitor binding channel are needed to maintain inhibitor occupancy while counteracting the SF3B transition to a closed state that is required for stable U2 snRNP interactions with the intron.

Herboxidiene is a potent antitumor agent that targets the SF3B subunit of the spliceosome. Herboxidiene possesses a complex structural architecture with nine stereocenters and design of potent less complex structures would be of interest as a drug lead as well as a tool for studying SF3B1 function in splicing. We investigated a number of C-6 modified herboxidiene derivatives in an effort to eliminate this stereocenter and, also to understand the importance of this functionality. The syntheses of structural variants involved a Suzuki-Miyaura cross-coupling reaction as the key step. The functionalized tetrahydrofuran core has been constructed from commercially available optically active tri-O-acetyl-d-glucal. We investigated the effect of these derivatives on splicing chemistry. The C-6 alkene derivative showed very potent splicing inhibitory activity similar to herboxidiene. Furthermore, the C-6 gem-dimethyl derivative also exhibited very potent in vitro splicing inhibitory activity comparable to herboxidiene.

Since 2012, the United States of America has experienced a biennial spike in pediatric acute flaccid myelitis (AFM)1-6. Epidemiologic evidence suggests non-polio enteroviruses (EVs) are a potential etiology, yet EV RNA is rarely detected in cerebrospinal fluid (CSF)2. CSF from children with AFM (n = 42) and other pediatric neurologic disease controls (n = 58) were investigated for intrathecal antiviral antibodies, using a phage display library expressing 481,966 overlapping peptides derived from all known vertebrate and arboviruses (VirScan). Metagenomic next-generation sequencing (mNGS) of AFM CSF RNA (n = 20 cases) was also performed, both unbiased sequencing and with targeted enrichment for EVs. Using VirScan, the viral family significantly enriched by the CSF of AFM cases relative to controls was Picornaviridae, with the most enriched Picornaviridae peptides belonging to the genus Enterovirus (n = 29/42 cases versus 4/58 controls). EV VP1 ELISA confirmed this finding (n = 22/26 cases versus 7/50 controls). mNGS did not detect additional EV RNA. Despite rare detection of EV RNA, pan-viral serology frequently identified high levels of CSF EV-specific antibodies in AFM compared with controls, providing further evidence for a causal role of non-polio EVs in AFM.

Patient falls remain a major cause of adverse events in the medical setting. Many patients receiving Mohs micrographic surgery are at high risk, both for falling and resultant injuries. Although the incidence of patient falls in dermatologic surgery is low, falls can have significant consequences for both patient and provider. Therefore, effective interventions to improve organizational safety are critical. Though there is a considerable amount of research pertaining to fall prevention strategies, the majority of studies have been confined to the inpatient setting and long-term care facilities. Implementation of fall prevention initiatives in the outpatient setting has rarely been evaluated and no studies have focused on the Mohs patient population to date. Methods: We reviewed the literature pertaining to fall risk and prevention guidelines in the inpatient and outpatient settings as it applies to the dermatologic surgery environment. Results: Herein we will discuss patient risk factors for falling relevant to the Mohs setting and review existing validated fall risk assessment tools and strategies for fall prevention. Conclusion: Identifying fall risk factors can improve patient safety and reduce falls in the dermatologic surgery clinic.

Hepatic proteomes are intricately controlled through biosynthesis, extracellular secretion, and intrahepatic degradation. Autophagy governs lysosome‐mediated intrahepatic degradation and the hepatic proteome. When autophagy is impaired, it leads to the accumulation of intrahepatic proteins, causing proteinopathy. This study investigates whether autophagy can modulate the hepatic proteome non‐degradatively. Utilizing conditional, inducible, and hepatotoxin models of hepatic autophagy impairment, we assessed the overall hepatic proteome expression using Coomassie brilliant blue (CBB) staining and liquid chromatography–tandem mass spectrometry (LC/MS). We pinpointed and confirmed four specific hepatic proteins—Cps1, Ahcy, Ca3, and Gstm1—that were selectively modified in autophagy‐deficient livers. Expression of Cps1, Ahcy, and Ca3 were significantly reduced, while Gstm1 expression increased in livers with autophagy impairment. Interestingly, these changes in hepatic protein levels were not due to defective autophagic degradation but were associated with alterations in mRNA transcript levels. Moreover, as a result of autophagic dysfunction, sustained activation of the nuclear erythroid‐derived 2‐like 2 (Nrf2) transcription factor, transcriptionally regulated the mRNA levels of these proteins. Our findings indicate that autophagy can influence hepatic proteins not solely via traditional degradative routes but also through non‐degradative transcriptional processes by modulating Nrf2. [ABSTRACT FROM AUTHOR]

By July 2021, >33 million cases of coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), were documented in the United States, and most cases involved contact [...]

Acute flaccid myelitis (AFM) is a clinical syndrome characterized by the acute onset of flaccid limb weakness accompanied by spinal cord gray matter lesions. AFM is a known complication of [...]

To determine the breadth and underpinning of changes in immunocyte gene expression due to genetic variation in mice, we performed, as part of the Immunological Genome Project, gene expression profiling for CD4(+) T cells and neutrophils purified from 39 inbred strains of the Mouse Phenome Database. Considering both cell types, a large number of transcripts showed significant variation across the inbred strains, with 22% of the transcriptome varying by 2-fold or more. These included 119 loci with apparent complete loss of function, where the corresponding transcript was not expressed in some of the strains, representing a useful resource of "natural knockouts." We identified 1222 cis-expression quantitative trait loci (cis-eQTL) that control some of this variation. Most (60%) cis-eQTLs were shared between T cells and neutrophils, but a significant portion uniquely impacted one of the cell types, suggesting cell type-specific regulatory mechanisms. Using a conditional regression algorithm, we predicted regulatory interactions between transcription factors and potential targets, and we demonstrated that these predictions overlap with regulatory interactions inferred from transcriptional changes during immunocyte differentiation. Finally, comparison of these and parallel data from CD4(+) T cells of healthy humans demonstrated intriguing similarities in variability of a gene's expression: the most variable genes tended to be the same in both species, and there was an overlap in genes subject to strong cis-acting genetic variants. We speculate that this "conservation of variation" reflects a differential constraint on intraspecies variation in expression levels of different genes, either through lower pressure for some genes, or by favoring variability for others.

As part of the Immunological Genome Project (ImmGen), gene expression was determined in unstimulated (circulating) mouse neutrophils and three populations of neutrophils activated in vivo, with comparison among these populations and to other leukocytes. Activation conditions included serum-transfer arthritis (mediated by immune complexes), thioglycollate-induced peritonitis, and uric acid-induced peritonitis. Neutrophils expressed fewer genes than any other leukocyte population studied in ImmGen, and down-regulation of genes related to translation was particularly striking. However, genes with expression relatively specific to neutrophils were also identified, particularly three genes of unknown function: Stfa2l1, Mrgpr2a and Mrgpr2b. Comparison of genes up-regulated in activated neutrophils led to several novel findings: increased expression of genes related to synthesis and use of glutathione and of genes related to uptake and metabolism of modified lipoproteins, particularly in neutrophils elicited by thioglycollate; increased expression of genes for transcription factors in the Nr4a family, only in neutrophils elicited by serum-transfer arthritis; and increased expression of genes important in synthesis of prostaglandins and response to leukotrienes, particularly in neutrophils elicited by uric acid. Up-regulation of genes related to apoptosis, response to microbial products, NFkB family members and their regulators, and MHC class II expression was also seen, in agreement with previous studies. A regulatory model developed from the ImmGen data was used to infer regulatory genes involved in the changes in gene expression during neutrophil activation. Among 64, mostly novel, regulatory genes predicted to influence these changes in gene expression, Irf5 was shown to be important for optimal secretion of IL-10, IP-10, MIP-1α, MIP-1β, and TNF-α by mouse neutrophils in vitro after stimulation through TLR9. This data-set and its analysis using the ImmGen regulatory model provide a basis for additional hypothesis-based research on the importance of changes in gene expression in neutrophils in different conditions.