Analogs of α-conotoxin PnIC selectively inhibit α7ß2- over α7-only subtype nicotinic acetylcholine receptors via a novel allosteric mechanism.

This study was undertaken to identify and characterize the first ligands capable of selectively identifying nicotinic acetylcholine receptors containing α7 and ß2 subunits (α7ß2-nAChR subtype). Basal forebrain cholinergic neurons express α7ß2-nAChR. Here, they appear to mediate neuronal dysfunction induced by the elevated levels of oligomeric amyloid-ß associated with early Alzheimer's disease. Additional work indicates that α7ß2-nAChR are expressed across several further critically important cholinergic and GABAergic neuronal circuits within the central nervous system. Further studies, however, are significantly hindered by the inability of currently available ligands to distinguish heteromeric α7ß2-nAChR from the closely related and more widespread homomeric α7-only-nAChR subtype. Functional screening using two-electrode voltage-clamp electrophysiology identified a family of α7ß2-nAChR-selective analogs of α-conotoxin PnIC (α-CtxPnIC). A combined electrophysiology, functional kinetics, site-directed mutagenesis, and molecular dynamics approach was used to further characterize the α7ß2-nAChR selectivity and site of action of these α-CtxPnIC analogs. We determined that α7ß2-nAChR selectivity of α-CtxPnIC analogs arises from interactions at a site distinct from the orthosteric agonist-binding site shared between α7ß2- and α7-only-nAChR. As numerous previously identified α-Ctx ligands are competitive antagonists of orthosteric agonist-binding sites, this study profoundly expands the scope of use of α-Ctx ligands (which have already provided important nAChR research and translational breakthroughs). More immediately, analogs of α-CtxPnIC promise to enable, for the first time, both comprehensive mapping of the distribution of α7ß2-nAChR and detailed investigations of their physiological roles.

A Novel Macroglossia Severity Index for Beckwith-Wiedemann Syndrome.

OBJECTIVE/ SUMMARY BACKGROUND DATA: We propose the first classification scheme for macroglossia in patients with Beckwith-Wiedemann Syndrome (BWS), the BWS Index of macroGlossia (BIG). METHODS: Patients with molecularly confirmed BWS seen from 2004-2023 were included to develop this system. Relationships among BIG scores, tongue reduction surgery, BWS clinical score, percent mosaicism, and polysomnography findings were examined. RESULTS: Patients were classified from BIG0 to BIG3. BIG0 includes those without macroglossia; BIG1 includes those with macroglossia not protruding beyond the teeth/alveolus; BIG2 includes those with tongue protrusion past the teeth/alveolus to the lips but that can be contained within the mouth; and BIG3 includes those with tongues that protrude beyond the teeth/alveolus and lips but that cannot be closed within the mouth. Of the 459 patients with molecularly confirmed BWS, 266 (58.0%) patients were scored. One hundred and eleven (41.7%) were BIG0, 44 (16.5%) were BIG1, 90 (33.8%) were BIG2, and 21 (7.9%) were BIG3. As scores increased, patients had an increased incidence of tongue reduction surgery (BIG0: 0% versus BIG1: 20.5% versus BIG2: 51.1% versus BIG3: 100%; r=0.66, P <0.01). Higher BIG scores were associated with elevated BWS clinical scores (r=0.68, P <0.01) and increased tissue mosaicism (r=0.50, P <0.01) as well as trends towards worse obstructive apnea-hypopnea indices (r=0.29, P =0.02) and lower SpO 2 nadirs (r=-0.29, P =0.02). CONCLUSION: In this large series of patients with Beckwith-Wiedemann Syndrome, increased BIG score correlates with undergoing tongue reduction surgery and increased phenotypic severity. Adoption of the BIG scoring system may facilitate communication and risk stratification across institutions.

Infection with 'Candidatus Liberibacter asiaticus' improves the fecundity of Diaphorina citri aiding its proliferation: A win-win strategy.

The evolution of insect vector-pathogen relationships has long been of interest in the field of molecular ecology. One system of special relevance, due to its economic impacts, is that between Diaphorina citri and 'Candidatus Liberibacter asiaticus' (CLas), the cause of the severe Asian form of huanglongbing. CLas-positive D. citri are more fecund than their CLas-negative counterparts, boosting opportunities for pathogens to acquire new vector hosts. The molecular mechanism behind this life-history shift remains unclear. Here, we found that CLas promoted ovarian development and increased the expression of the vitellogenin receptor (DcVgR) in ovaries. DcVgR RNAi significantly decreased fecundity and CLas titer in ovaries, extended the preoviposition period, shortened the oviposition period and blocked ovarian development. Given their importance in gene regulation, we explored the role of miRNAs in shaping these phenotypes and their molecular triggers. Our results showed that one miRNA, miR-275, suppressed DcVgR expression by binding to its 3' UTR. Overexpression of miR-275 knocked down DcVgR expression and CLas titer in ovaries, causing reproductive defects that mimicked DcVgR knockdown phenotypes. We focused, further, on roles of the Juvenile Hormone (JH) pathway in shaping the observed fecundity phenotype, given its known impacts on ovarian development. After CLas infection, this pathway was upregulated, thereby increasing DcVgR expression. From these combined results, we conclude that CLas hijacks the JH signalling pathway and miR-275, thereby targeting DcVgR to increase D. citri fecundity. These changes simultaneously increase CLas replication, suggesting a pathogen-vector host mutualism, or a seemingly helpful, but cryptically costly life-history manipulation.

Expanded phenotype and cancer risk in patients with Beckwith-Wiedemann spectrum caused by CDKN1C variants.

Beckwith-Wiedemann spectrum (BWSp) is caused by genetic and epigenetic alterations on chromosome 11 that regulate cell growth and division. Considering the diverse phenotypic landscape in BWSp, the characterization of the CDKN1C molecular subtype remains relatively limited. Here, we investigate the role of CDKN1C in the broader BWSp phenotype. Notably, patients with CDKN1C variants appear to exhibit a different tumor risk than other BWSp molecular subtypes. We performed a comprehensive literature review using the search term "CDKN1C Beckwith" to identify 113 cases of patients with molecularly confirmed CDKN1C-BWSp. We then assessed the genotype and phenotype in a novel cohort of patients with CDKN1C-BWSp enrolled in the BWS Research Registry. Cardinal and suggestive features were evaluated for all patients reported, and tumor risk was established based on available reports. The most common phenotypes included macroglossia, omphalocele, and ear creases/pits. Tumor types reported from the literature included neuroblastoma, acute lymphocytic leukemia, superficial spreading melanoma, and intratubular germ cell neoplasia. Overall, this study identifies unique features associated with CDKN1C variants in BWSp, enabling more accurate clinical management. The absence of Wilms tumor and hepatoblastoma suggests that screening for these tumors may not be necessary, while the neuroblastoma risk warrants appropriate screening recommendations.

A potential cost of evolving epibatidine resistance in poison frogs.

BACKGROUND: Some dendrobatid poison frogs sequester the toxin epibatidine as a defense against predators. We previously identified an amino acid substitution (S108C) at a highly conserved site in a nicotinic acetylcholine receptor ß2 subunit of dendrobatid frogs that decreases sensitivity to epibatidine in the brain-expressing α4ß2 receptor. Introduction of S108C to the orthologous high-sensitivity human receptor similarly decreased sensitivity to epibatidine but also decreased sensitivity to acetylcholine, a potential cost if this were to occur in dendrobatids. This decrease in the acetylcholine sensitivity manifested as a biphasic acetylcholine concentration-response curve consistent with the addition of low-sensitivity receptors. Surprisingly, the addition of the ß2 S108C into the α4ß2 receptor of the dendrobatid Epipedobates anthonyi did not change acetylcholine sensitivity, appearing cost-free. We proposed that toxin-bearing dendrobatids may have additional amino acid substitutions protecting their receptors from alterations in acetylcholine sensitivity. To test this, in the current study, we compared the dendrobatid receptor to its homologs from two non-dendrobatid frogs. RESULTS: The introduction of S108C into the α4ß2 receptors of two non-dendrobatid frogs also does not affect acetylcholine sensitivity suggesting no additional dendrobatid-specific substitutions. However, S108C decreased the magnitude of neurotransmitter-induced currents in Epipedobates and the non-dendrobatid frogs. We confirmed that decreased current resulted from fewer receptors in the plasma membrane in Epipedobates using radiolabeled antibodies against the receptors. To test whether S108C alteration of acetylcholine sensitivity in the human receptor was due to (1) adding low-sensitivity binding sites by changing stoichiometry or (2) converting existing high- to low-sensitivity binding sites with no stoichiometric alteration, we made concatenated α4ß2 receptors in stoichiometry with only high-sensitivity sites. S108C substitutions decreased maximal current and number of immunolabeled receptors but no longer altered acetylcholine sensitivity. CONCLUSIONS: The most parsimonious explanation of our current and previous work is that the S108C substitution renders the ß2 subunit less efficient in assembling/trafficking, thereby decreasing the number of receptors in the plasma membrane. Thus, while ß2 S108C protects dendrobatids against sequestered epibatidine, it incurs a potential physiological cost of disrupted α4ß2 receptor function.

Natural Infection of Murraya paniculata and Murraya sumatrana with CLas in Java.

The phloem-limited bacterium, 'Candidatus Liberibacter asiaticus' (CLas), is the putative causal pathogen of the severe Asiatic form of huanglongbing (citrus greening) and is most commonly transmitted by the Asiatic citrus psyllid (ACP), Diaphorina citri. CLas severely affects many Citrus species and hybrids and has been recorded in the Citrus relative, orange jasmine, Murraya paniculata (L.) Jack (syn. M. exotica L.). In this study, 13 accessions of three Murraya species (M. paniculata, M. sumatrana Roxb. and M. lucida (G.Forst.) Mabb,) and the Papuan form of a putative hybrid (M. omphalocarpa Hayata) were identified morphologically and molecularly based on sequence identity of the matK-5'trnK region of the chloroplast genome, and infection on these plants under field conditions was determined by PCR and qPCR on 2-4 occasions over 14 months. CLas was repeatedly detected in leaflet midribs by PCR and qPCR on four and three accessions of M. paniculata and M. sumatrana, respectively. It was not detected in leaflet midribs of single accessions of M. lucida and M. omphalocarpa. The species identification of the CLas-positive accessions was further confirmed using all the molecular taxonomic markers consisting of the six fragments of the maternally inherited chloroplast genome and part of the nuclear-encoded ITS region. The results indicated that natural infection of M. paniculata and M. sumatrana with CLas can occur in Java. This is the first demonstration of the natural infection of M. sumatrana with CLas. Further studies are required to determine if infections persist in the absence of D. citri.

Wound repair in sea urchin larvae involves pigment cells and blastocoelar cells.

Sea urchin larvae spend weeks to months feeding on plankton prior to metamorphosis. When handled in the laboratory they are easily injured, suggesting that in the plankton they are injured with some frequency. Fortunately, larval wounds are repaired through an efficient wound response with mesenchymal pigment cells and blastocoelar cells assisting as the epithelium closes. An injury to the epithelium leads to an immediate calcium transient that rapidly spreads around the entire larva and is necessary for activating pigment cell migration toward the wound. If calcium transport is blocked, the pigment cells fail to activate and remain in place. When activated, pigment cells initiate directed migration to the wound site from distances of at least 85 â€‹µm. Upon arrival at the wound site they participate in an innate immune response. Blastocoelar cells are recruited to the injury site as well, though the calcium transient is unnecessary for activating these cells. At the wound site, blastocoelar cells participate in several functions including remodeling the skeleton if it protrudes through the epithelium.

Therapeutic targeting of TRAIL death receptors.

The discovery of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) along with its potent and selective antitumor effects initiated a decades-long search for therapeutic strategies to target the TRAIL pathway. First-generation approaches were focused on the development of TRAIL receptor agonists (TRAs), including recombinant human TRAIL (rhTRAIL) and TRAIL receptor-targeted agonistic antibodies. While such TRAIL pathway-targeted therapies showed promise in preclinical data and clinical trials have been conducted, none have advanced to FDA approval. Subsequent second-generation approaches focused on improving upon the specific limitations of first-generation approaches by ameliorating the pharmacokinetic profiles and agonistic abilities of TRAs as well as through combinatorial approaches to circumvent resistance. In this review, we summarize the successes and shortcomings of first- and second-generation TRAIL pathway-based therapies, concluding with an overview of the discovery and clinical introduction of ONC201, a compound with a unique mechanism of action that represents a new generation of TRAIL pathway-based approaches. We discuss preclinical and clinical findings in different tumor types and provide a unique perspective on translational directions of the field.

Familial Beckwith-Wiedemann syndrome in a multigenerational family: Forty years of careful phenotyping.

Beckwith-Wiedemann Spectrum (BWSp) is an overgrowth and cancer predisposition disorder characterized by a wide spectrum of phenotypic manifestations including macroglossia, abdominal wall defects, neonatal hypoglycemia, and predisposition to embryonal tumors. In 1981, Best and Hoekstra reported four patients with BWSp in a single family which suggested autosomal dominant inheritance, but standard clinical testing for BWSp was not available during this time. Meticulous phenotyping of this family has occurred over the past 40 years of follow-up with additional family members being identified and samples collected for genetic testing. Genetic testing revealed a pathogenic mutation in CDKN1C, consistent with the most common cause of familial BWSp. CDKN1C mutations account for just 5% of sporadic cases of BWSp. Here, we report the variable presentation of BWSp across the individuals affected by the CDKN1C mutation and other extended family members spanning multiple generations, all examined by the same physician. Additional phenotypes thought to be atypical in patients with BWSp were reported which included cardiac abnormalities. The incidence of tumors was documented in extended family members and included rhabdomyosarcoma, astrocytoma, and thyroid carcinoma, which have previously been reported in patients with BWSp. These observations suggest that in addition to the inheritance of the CDKN1C variant, there are modifying factors in this family driving the phenotypic spectrum observed. Alternative theories are suggested to explain the etiology of clinical variability including diffused mosaicism, anticipation, and the presence of additional variants tracking in the family. This study highlights the necessity of long-term follow-up in patients with BWSp and consideration of individual familial characteristics in the context of phenotype and/or (epi)genotype associations.

Discoveries and future significance of research into amyloid-beta/α7-containing nicotinic acetylcholine receptor (nAChR) interactions.

Initiated by findings that Alzheimer's disease is associated with a profound loss of cholinergic markers in human brain, decades of studies have examined the interactions between specific subtypes of nicotinic acetylcholine receptors and amyloid-ß [derived from the amyloid precursor protein (APP), which is cleaved to yield variable isoforms of amyloid-ß]. We review the evolving understanding of amyloid-ß's roles in Alzheimer's disease and pioneering studies that highlighted a role of nicotinic acetylcholine receptors in mediating important aspects of amyloid-ß's effects. This review also surveys the current state of research into amyloid-ß / nicotinic acetylcholine receptor interactions. The field has reached an exciting point in which common themes are emerging from the wide range of prior research and a range of accessible, relevant model systems are available to drive further progress. We highlight exciting new areas of inquiry and persistent challenges that need to be considered while conducting this research. Studies of amyloid-ß and the nicotinic acetylcholine receptor populations that it interacts with provide opportunities for innovative basic and translational scientific breakthroughs related to nicotinic receptor biology, Alzheimer's disease, and cholinergic contributions to cognition more broadly.

Electromyography in the prognostication of recovery in patients with acute peripheral facial nerve palsy: A systematic review.

OBJECTIVES: Needle electromyography (EMG) may be used to characterise the severity of the injury in acute peripheral facial nerve palsy (FNP) to predict recovery and guide management, but its prognostic value and clinical utility remain controversial. The aim of this systematic review was to evaluate the role of EMG to prognosticate the recovery of facial motor function in patients with acute peripheral FNP. DESIGN: A comprehensive search strategy was applied in PubMed, Embase, and Web of Science based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The main outcome measure was the accuracy of EMG in predicting long-term facial function at least 6 months following symptom onset. RESULTS: Eleven studies were included comprising 3837 participants, with 91.6% of these diagnosed with Bell's palsy (BP). In BP patients, the positive predictive value and negative predictive value for a good outcome based on EMG findings ranged from 82.1% to 100% and 66.7% to 80.5%, respectively, with two out of three studies finding that EMG remained a significant predictor of the outcome on multivariate analysis. Three studies addressed the role of EMG in non-idiopathic FNP with two of these studies supporting EMG to predict prognosis. CONCLUSIONS: EMG is a useful tool to gain insight into the likely outcome to guide management decisions and counsel patients on their expectations, particularly in BP. However, given inconsistencies in its application and lack of evidence around non-idiopathic FNP, it should not currently be relied on to predict recovery. Ultimately, its prognostic value and widespread adoption are dependent on the implementation of a clear and standardised protocol in future high-quality studies and routine clinical settings.

Communicating Results of Drinking Water Tests From Private Wells: Designing Report-Back Materials to Facilitate Understanding.

This evaluation assessed the effectiveness of graphic-based (i.e., pictorial) report-back materials in communicating the presence of toxic metals in private well water and soil samples. It also explored associations between recommendations in the report-back materials and appropriate actions to protect health taken by a subset of participants in an environmental monitoring pilot study. Overall, 39 residents of Stokes County, North Carolina, participated in the Well Empowered pilot study, which included water and soil testing and analysis. All participants received materials explaining the extent to which toxic metals were present in their well water and soil. A subset of participants (n = 14) responded to a follow-up evaluation, which showed that many found at least one component of their test results "very easy to understand." The existence of a federal standard for comparison appeared to influence participant recall of results, which was more accurate for contaminants with a federal maximum contaminant level. Our evaluation results suggest that a simple pictorial format, in combination with more detailed supporting text, can be useful in highlighting results that require action.

Implications of Oligomeric Amyloid-Beta (oAß42) Signaling through α7ß2-Nicotinic Acetylcholine Receptors (nAChRs) on Basal Forebrain Cholinergic Neuronal Intrinsic Excitability and Cognitive Decline.

Neuronal and network-level hyperexcitability is commonly associated with increased levels of amyloid-ß (Aß) and contribute to cognitive deficits associated with Alzheimer's disease (AD). However, the mechanistic complexity underlying the selective loss of basal forebrain cholinergic neurons (BFCNs), a well-recognized characteristic of AD, remains poorly understood. In this study, we tested the hypothesis that the oligomeric form of amyloid-ß (oAß42), interacting with α7-containing nicotinic acetylcholine receptor (nAChR) subtypes, leads to subnucleus-specific alterations in BFCN excitability and impaired cognition. We used single-channel electrophysiology to show that oAß42 activates both homomeric α7- and heteromeric α7ß2-nAChR subtypes while preferentially enhancing α7ß2-nAChR open-dwell times. Organotypic slice cultures were prepared from male and female ChAT-EGFP mice, and current-clamp recordings obtained from BFCNs chronically exposed to pathophysiologically relevant level of oAß42 showed enhanced neuronal intrinsic excitability and action potential firing rates. These resulted from a reduction in action potential afterhyperpolarization and alterations in the maximal rates of voltage change during spike depolarization and repolarization. These effects were observed in BFCNs from the medial septum diagonal band and horizontal diagonal band, but not the nucleus basalis. Last, aged male and female APP/PS1 transgenic mice, genetically null for the ß2 nAChR subunit gene, showed improved spatial reference memory compared with APP/PS1 aged-matched littermates. Combined, these data provide a molecular mechanism supporting a role for α7ß2-nAChR in mediating the effects of oAß42 on excitability of specific populations of cholinergic neurons and provide a framework for understanding the role of α7ß2-nAChR in oAß42-induced cognitive decline.

Transcriptomic and epigenomic dynamics associated with development of human iPSC-derived GABAergic interneurons.

GABAergic interneurons (GINs) are a heterogeneous population of inhibitory neurons that collectively contribute to the maintenance of normal neuronal excitability and network activity. Identification of the genetic regulatory elements and transcription factors that contribute toward GIN function may provide new insight into the pathways underlying proper GIN activity while also indicating potential therapeutic targets for GIN-associated disorders, such as schizophrenia and epilepsy. In this study, we examined the temporal changes in gene expression and chromatin accessibility during GIN development by performing transcriptomic and epigenomic analyses on human induced pluripotent stem cell-derived neurons at 22, 50 and 78 days (D) post-differentiation. We observed 13 221 differentially accessible regions (DARs) of chromatin that associate with temporal changes in gene expression at D78 and D50, relative to D22. We also classified families of transcription factors that are increasingly enriched at DARs during differentiation, indicating regulatory networks that likely drive GIN development. Collectively, these data provide a resource for examining the molecular networks regulating GIN functionality.

Ethics, virtues and xenotransplantation.

Early in 2022 the first pig to human cardiac xenotransplant was performed. The graft initially performed well, and rejection was well controlled. However, the graft failed, and the patient died 60 days after the procedure. The ethical issues relating to xenotransplantation include the risk/benefit to the individual, the risk of porcine-derived infectious agents crossing into humans, animal welfare and rights, issues of human and animal identity and concerns relating to fair allocation of organs and appropriate use of resources.These ethical issues are often addressed using emotional arguments, or through consequentialist or deontological lens. An alternative is to use approaches based on virtue ethics to understand the moral purpose (telos) of the research and the virtues (character traits) needed to be a good research clinician. In this review we will consider the virtues of justice, courage, temperance and practical wisdom, as well as the role of clinical curiosity, and their application to xenotransplantation. This provides an alternative approach for the clinical academic and others involved in the research to reflect on their practice.

Eagle: multi-locus association mapping on a genome-wide scale made routine.

MOTIVATION: We present Eagle, a new method for multi-locus association mapping. The motivation for developing Eagle was to make multi-locus association mapping 'easy' and the method-of-choice. Eagle's strengths are that it (i) is considerably more powerful than single-locus association mapping, (ii) does not suffer from multiple testing issues, (iii) gives results that are immediately interpretable and (iv) has a computational footprint comparable to single-locus association mapping. RESULTS: By conducting a large simulation study, we will show that Eagle finds true and avoids false single-nucleotide polymorphism trait associations better than competing single- and multi-locus methods. We also analyze data from a published mouse study. Eagle found over 50% more validated findings than the state-of-the-art single-locus method. AVAILABILITY AND IMPLEMENTATION: Eagle has been implemented as an R package, with a browser-based Graphical User Interface for users less familiar with R. It is freely available via the CRAN website at https://cran.r-project.org. Videos, Quick Start guides, FAQs and Demos are available via the Eagle website http://eagle.r-forge.r-project.org. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

SARS-CoV-2: Pathogenic Mechanisms and Host Immune Response.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an enveloped, positive-sense RNA coronavirus responsible for the COVID-19 pandemic. Since December 2019, coronavirus disease 2019 (COVID-19) has affected more than 127 million people, 2.7 million deaths globally (as per WHO dashboard, dated 31 March, 2020), the virus is capable of transmitting from human to human via inhalation of infected respiratory droplets or aerosols or contact with infected fomites. Clinically, patients with COVID-19 present with severe respiratory distress syndrome, which is very similar to the presentation of other respiratory viral infections. A huge variation in the host response exists, with the resulting symptoms varying from mild to moderate. Comorbidities such as cardiovascular disease, hypertension, diabetes, coagulation dysfunction, stroke, malignant tumor and multiple organ dysfunction syndrome, as well as age and sex, are associated with severe COVID-19 cases. So far, no targeted therapies have been developed to treat this disease and existing drugs are being investigated for repurposing. This chapter discusses the epidemiology, clinical features of COVID-19, pathogenesis and the innate and adaptive immune response mounted by the host to the SARS-CoV-2 infection. A deeper understanding of the host-pathogen interaction is fundamental to the development of a vaccine.

Therapeutic Targeting of Alternative RNA Splicing in Gastrointestinal Malignancies and Other Cancers.

Recent comprehensive genomic studies including single-cell RNA sequencing and characterization have revealed multiple processes by which protein-coding and noncoding RNA processing are dysregulated in many cancers. More specifically, the abnormal regulation of mRNA and precursor mRNA (pre-mRNA) processing, which includes the removal of introns by splicing, is frequently altered in tumors, producing multiple different isoforms and diversifying protein expression. These alterations in RNA processing result in numerous cancer-specific mRNAs and pathogenically spliced events that generate altered levels of normal proteins or proteins with new functions, leading to the activation of oncogenes or the inactivation of tumor suppressor genes. Abnormally spliced pre-mRNAs are also associated with resistance to cancer treatment, and certain cancers are highly sensitive to the pharmacological inhibition of splicing. The discovery of these alterations in RNA processing has not only provided new insights into cancer pathogenesis but identified novel therapeutic vulnerabilities and therapeutic opportunities in targeting these aberrations in various ways (e.g., small molecules, splice-switching oligonucleotides (SSOs), and protein therapies) to modulate alternative RNA splicing or other RNA processing and modification mechanisms. Some of these strategies are currently progressing toward clinical development or are already in clinical trials. Additionally, tumor-specific neoantigens produced from these pathogenically spliced events and other abnormal RNA processes provide a potentially extensive source of tumor-specific therapeutic antigens (TAs) for targeted cancer immunotherapy. Moreover, a better understanding of the molecular mechanisms associated with aberrant RNA processes and the biological impact they play might provide insights into cancer initiation, progression, and metastasis. Our goal is to highlight key alternative RNA splicing and processing mechanisms and their roles in cancer pathophysiology as well as emerging therapeutic alternative splicing targets in cancer, particularly in gastrointestinal (GI) malignancies.

The RNA-binding protein, ZC3H14, is required for proper poly(A) tail length control, expression of synaptic proteins, and brain function in mice.

A number of mutations in genes that encode ubiquitously expressed RNA-binding proteins cause tissue specific disease. Many of these diseases are neurological in nature revealing critical roles for this class of proteins in the brain. We recently identified mutations in a gene that encodes a ubiquitously expressed polyadenosine RNA-binding protein, ZC3H14 (Zinc finger CysCysCysHis domain-containing protein 14), that cause a nonsyndromic, autosomal recessive form of intellectual disability. This finding reveals the molecular basis for disease and provides evidence that ZC3H14 is essential for proper brain function. To investigate the role of ZC3H14 in the mammalian brain, we generated a mouse in which the first common exon of the ZC3H14 gene, exon 13 is removed (Zc3h14Δex13/Δex13) leading to a truncated ZC3H14 protein. We report here that, as in the patients, Zc3h14 is not essential in mice. Utilizing these Zc3h14Δex13/Δex13mice, we provide the first in vivo functional characterization of ZC3H14 as a regulator of RNA poly(A) tail length. The Zc3h14Δex13/Δex13 mice show enlarged lateral ventricles in the brain as well as impaired working memory. Proteomic analysis comparing the hippocampi of Zc3h14+/+ and Zc3h14Δex13/Δex13 mice reveals dysregulation of several pathways that are important for proper brain function and thus sheds light onto which pathways are most affected by the loss of ZC3H14. Among the proteins increased in the hippocampi of Zc3h14Δex13/Δex13 mice compared to control are key synaptic proteins including CaMK2a. This newly generated mouse serves as a tool to study the function of ZC3H14 in vivo.

Functional morphology of endurance swimming performance and gait transition strategies in balistoid fishes.

Triggerfishes and filefishes (Balistoidea) use balistiform locomotion to power steady swimming with their dorsal and anal fins, and transition to a gait dominated by body and caudal fin (BCF) kinematics at high speeds. Fin and body shapes are predicted to be strong determinants of swimming performance and gait transitions. The goal of this study was to combine morphometrics and critical swimming tests to explore the relationships between fin and body shapes and swimming performance in a phylogenetic context in order to understand the evolution of balistiform swimming. Among 13 species of balistoid fishes, those with high aspect ratio fins tended to achieve higher critical swimming speeds than fishes with low aspect ratio fins. Species with long, large median fins and wide caudal peduncles used the balistiform gait alone for a larger percentage of their total critical swimming speed than fishes with short, small median fins and narrow caudal peduncles. Although analyses revealed overall positive relationships between median fin aspect ratios and gait transition speeds, fishes on both ends of the aspect ratio spectrum achieved higher swimming speeds using the balistiform gait alone than fishes with median fins of intermediate aspect ratios. Each species is specialized for taking advantage of one gait, with balistiform specialists possessing long, large median fins capable of the large power requirements of high-speed swimming using the median fins alone, while BCF specialists possess short, small median fins, ill-suited for powering high-speed balistiform locomotion, but narrow caudal peduncles capable of efficient caudal fin oscillations to power high-speed locomotion.