Mechanism of gabapentinoid potentiation of opioid effects on cyclic AMP signaling in neuropathic pain.

Over half of spinal cord injury (SCI) patients develop opioid-resistant chronic neuropathic pain. Safer alternatives to opioids for treatment of neuropathic pain are gabapentinoids (e.g., pregabalin and gabapentin). Clinically, gabapentinoids appear to amplify opioid effects, increasing analgesia and overdose-related adverse outcomes, but in vitro proof of this amplification and its mechanism are lacking. We previously showed that after SCI, sensitivity to opioids is reduced by fourfold to sixfold in rat sensory neurons. Here, we demonstrate that after injury, gabapentinoids restore normal sensitivity of opioid inhibition of cyclic AMP (cAMP) generation, while reducing nociceptor hyperexcitability by inhibiting voltage-gated calcium channels (VGCCs). Increasing intracellular Ca2+ or activation of L-type VGCCs (L-VGCCs) suffices to mimic SCI effects on opioid sensitivity, in a manner dependent on the activity of the Raf1 proto-oncogene, serine/threonine-protein kinase C-Raf, but independent of neuronal depolarization. Together, our results provide a mechanism for potentiation of opioid effects by gabapentinoids after injury, via reduction of calcium influx through L-VGCCs, and suggest that other inhibitors targeting these channels may similarly enhance opioid treatment of neuropathic pain.

Joint representation of molecular networks from multiple species improves gene classification.

Network-based machine learning (ML) has the potential for predicting novel genes associated with nearly any health and disease context. However, this approach often uses network information from only the single species under consideration even though networks for most species are noisy and incomplete. While some recent methods have begun addressing this shortcoming by using networks from more than one species, they lack one or more key desirable properties: handling networks from more than two species simultaneously, incorporating many-to-many orthology information, or generating a network representation that is reusable across different types of and newly-defined prediction tasks. Here, we present GenePlexusZoo, a framework that casts molecular networks from multiple species into a single reusable feature space for network-based ML. We demonstrate that this multi-species network representation improves both gene classification within a single species and knowledge-transfer across species, even in cases where the inter-species correspondence is undetectable based on shared orthologous genes. Thus, GenePlexusZoo enables effectively leveraging the high evolutionary molecular, functional, and phenotypic conservation across species to discover novel genes associated with diverse biological contexts.

KATP Channel Prodrugs Reduce Inflammatory and Neuropathic Hypersensitivity, Morphine-Induced Hypersensitivity, and Precipitated Withdrawal in Mice.

Previous studies show ATP-sensitive potassium (KATP) channel openers can reduce hypersensitivity associated with chronic pain models in rodents, and reduce morphine tolerance. Many agonists of KATP channels are not soluble in physiologically relevant vehicles, requiring adaptation for clinical use. This study compared the antinociceptive activity of novel KATP channel targeting prodrugs, CKLP1, CKLP2, and CF3-CKLP. These prodrugs are activated by endogenous alkaline phosphatase enzymes present in the peripheral and central nervous systems. Analgesic capabilities of intrathecally injected prodrugs were tested in rodent models of spinal nerve ligation (SNL) and complete Freund's adjuvant (CFA) as models for neuropathic and inflammatory pain, respectively. CKLP1 and CKLP2 significantly increased mechanical paw withdrawal thresholds 1-2 hours after intrathecal administration in the SNL model, but all three prodrugs were able to attenuate hypersensitivity up to 7 days after CFA treatment. The reduction of opioid tolerance and opioid-induced hypersensitivity in mice treated chronically with morphine was significantly reduced in CKLP1 and CKLP2 treated animals. Prodrug cleavage was confirmed in mouse spinal cords using liquid chromatography. These studies may aid in the further development of KATP channel prodrugs for use in treatments of chronic pain, opioid tolerance, and withdrawal. SIGNIFICANCE STATEMENT: The cromakalim prodrugs, CKLP1, CKLP2, and CF3-CKLP1 reduced hypersensitivity in inflammatory and neuropathic pain models in male and female mice. CKLP1 and CKLP2 also reduced morphine-induced hypersensitivity in a mouse model of chronic morphine exposure. CKLP2 reduced jumping and rearing behaviors after naloxone-induced precipitated morphine withdrawal. Taken together, CKLP2 demonstrates the potential for development as a non-opioid analgesic drug.

Therapy outcomes associated with prescription cannabidiol use at 12 months post-initiation.

OBJECTIVE: This study evaluated prescription cannabidiol (CBD) outcomes during the first 12 months of therapy. METHODS: A single-center, prospective cohort study was performed including patients prescribed CBD from January 2019 - April 2020, excluding clinical trial patients and those using external specialty pharmacy services. The primary outcome wasepilepsy-related emergency healthcare service (EHS) use within 12 months of initation. Secondary outcomes included prescription CBD discontinuation rate and reason and concomitant anti-seizure medication (ASM) use. A multiple logistic regression model evaluated the odds of EHS use, adjusting for initial concomitant ASM count, age, and insurance type. RESULTS: The 136 patients included were 85% white, 50% female, and 68% pediatric. EHS utilization occurred in 37% (n = 50) of patients; 29 patients (21%, n = 20 pediatric, n = 9 adult) had at least one emergency department (ED) visit, 9 patients (7%) had two or more; 30 patients (22%, n = 22 pediatric, n = 8 adult) had at least one hospitalizaion. Median time to first ED and hospitalization was 69 (IQR 31-196) and 104 (IQR 38-179) days, respectively. Prescription CBD was discontinued in 31 patients (23%, n = 18 pediatric, n = 13 adult), due to major side effects (n = 12, 39%), common side effects (n = 11, 36%), and unsatisfactory response (n = 11, 36%). There was no significant change in concomitant ASM use. CONCLUSION: Despite potential benefits of prescription CBD, many patients utilize EHSs in the first 12 months of treatment with minimal changes in concomitant ASM use.

Specialty pharmacy integration and the role of an advanced certified pharmacy technician in prescription cannabidiol access.

BACKGROUND: Insurance requirements that limit access to prescription cannabidiol (CBD), an adjunct therapy for uncontrolled seizure disorders, may lead to treatment initiation delays. Integrated health-system specialty pharmacies (IHSSPs) use pharmacists and advance certified pharmacy technicians (CPhTs) to help navigate prescription CBD access requirements. OBJECTIVE(S): Evaluate time from initial specialty pharmacy referral to prescription CBD shipment. METHODS: This was a single-center, retrospective analysis of patients prescribed CBD from January 2019 to April 2020 by the outpatient neurology clinic and dispensed by the center's IHSSP. The primary outcome was the time to prescription CBD access, defined as days between the specialty pharmacy completing an initial patient assessment and first medication shipment. Secondary outcomes were percentage of patients requiring financial assistance and days between key steps in the access pathway. Data were collected from electronic health records and the specialty pharmacy patient management database. The CPhT was responsible for completing most portions of the access pathway under supervision of the clinical pharmacist. RESULTS: After screening, 136 patients were included: 50% male, 85% white, 60% insured by Medicaid, and median age 14 years (interquartile range [IQR] 9-21). The most common indication was Lennox-Gastaut syndrome (n = 117, 86%). Of the 129 patients (95%) who required a prior authorization (PA), 92% were approved (n = 119). Median time from initial assessment to first shipment was 7 days (IQR 4-13). Of patients for whom the CPhT helped obtain financial assistance (n = 14, 10%), all had $0 costs after assistance. Median times for secondary outcomes led by the CPhT in days were as follows: initial assessment completion to benefits investigation (BI) = 0 (IQR 0-0), BI to PA submission = 0 (IQR 0-0), and PA denial to appeal submission = 4 (IQR 1-7). CONCLUSION: IHSSP teams, particularly advanced CPhT roles, helped patients afford and initiate prescription CBD quickly.

Supervised learning is an accurate method for network-based gene classification.

BACKGROUND: Assigning every human gene to specific functions, diseases and traits is a grand challenge in modern genetics. Key to addressing this challenge are computational methods, such as supervised learning and label propagation, that can leverage molecular interaction networks to predict gene attributes. In spite of being a popular machine-learning technique across fields, supervised learning has been applied only in a few network-based studies for predicting pathway-, phenotype- or disease-associated genes. It is unknown how supervised learning broadly performs across different networks and diverse gene classification tasks, and how it compares to label propagation, the widely benchmarked canonical approach for this problem. RESULTS: In this study, we present a comprehensive benchmarking of supervised learning for network-based gene classification, evaluating this approach and a classic label propagation technique on hundreds of diverse prediction tasks and multiple networks using stringent evaluation schemes. We demonstrate that supervised learning on a gene's full network connectivity outperforms label propagaton and achieves high prediction accuracy by efficiently capturing local network properties, rivaling label propagation's appeal for naturally using network topology. We further show that supervised learning on the full network is also superior to learning on node embeddings (derived using node2vec), an increasingly popular approach for concisely representing network connectivity. These results show that supervised learning is an accurate approach for prioritizing genes associated with diverse functions, diseases and traits and should be considered a staple of network-based gene classification workflows. AVAILABILITY AND IMPLEMENTATION: The datasets and the code used to reproduce the results and add new gene classification methods have been made freely available. CONTACT: arjun@msu.edu. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Comparison of pharmacist- and provider-managed lithium in an inpatient medical center: A 6-month review.

BACKGROUND: Lithium is commonly used for the treatment of mood disorders and possesses a narrow therapeutic index. A medication utilization evaluation performed regarding its use at an academic medical center found that only 89.9% of patients received a lithium level within 24 hours of admission. This review prompted development of the evaluated protocol. OBJECTIVE: To compare pharmacist- and provider-managed safety and biochemical monitoring outcomes in a medical and psychiatric hospital population. METHODS: A retrospective chart review was conducted to identify hospitalized medical or psychiatric patients who received lithium therapy during a 6-month period. Patients were excluded if younger than 16 years or if lithium therapy was ordered but never administered. For cohort comparisons, descriptive statistics were used for baseline characteristics, and chi-square test or t test was used for outcomes. RESULTS: Pharmacists managed 67 patients versus 63 provider-managed patients. Pharmacist-managed patients were more likely to receive a lithium level within 24 hours of admission (100% vs. 89.1%, P = 0.012); receive a pregnancy test if indicated (90.5% vs. 41.7%, P < 0.001); have an identified drug interaction affecting lithium levels (47.8% vs. 27%, P = 0.014); and receive pharmacy-provided education (71.6% vs. 34.9%, P < 0.001). CONCLUSION: Patients initiated or maintained on lithium therapy require a unique level of management within the inpatient realm. The addition of lithium management to existing pharmacy services creates the opportunity to deliver safer and more complete patient care while expanding practice offerings for clinical pharmacists.

The impact of caffeine consumption during 50 hr of extended wakefulness on glucose metabolism, self-reported hunger and mood state.

Caffeine is known for its capacity to mitigate performance decrements. The metabolic side-effects are less well understood. This study examined the impact of cumulative caffeine doses on glucose metabolism, self-reported hunger and mood state during 50 hr of wakefulness. In a double-blind laboratory study, participants were assigned to caffeine (n = 9, 6M, age 21.3 ± 2.1 years; body mass index 21.9 ± 1.6 kg/m2 ) or placebo conditions (n = 8, 4M, age 23.0 ± 2.8 years; body mass index 21.8 ± 1.6 kg/m2 ). Following a baseline sleep (22:00 hours-08:00 hours), participants commenced 50 hr of sleep deprivation. Meal timing and composition were controlled throughout the study. Caffeine (200 mg) or placebo gum was chewed for 5 min at 01:00 hours, 03:00 hours, 05:00 hours and 07:00 hours during each night of sleep deprivation. Continual glucose monitors captured interstitial glucose 2 hr post-breakfast, at 5-min intervals. Hunger and mood state were assessed at 10:00 hours, 16:30 hours, 22:30 hours and 04:30 hours. Caffeine did not affect glucose area under the curve (p = 0.680); however, glucose response to breakfast significantly increased after 2 nights of extended wakefulness compared with baseline (p = 0.001). There was a significant main effect of day, with increased tiredness (p < 0.001), mental exhaustion (p < 0.001), irritability (p = 0.002) and stress (p < 0.001) on the second day of extended wake compared with day 1. Caffeine attenuated the rise in tiredness (p < 0.001), mental exhaustion (p = 0.044) and irritability (p = 0.018) on day 1 but not day 2. Self-reported hunger was not affected by sleep deprivation or caffeine. These data confirm the effectiveness of caffeine in improving performance under conditions of sleep deprivation by reducing feelings of tiredness, mental exhaustion and irritability without exacerbating glucose metabolism and feelings of hunger.

Breaking Bad Delirium: Methamphetamine and Boric Acid Toxicity with Hallucinations and Pseudosepsis.

OBJECTIVES: A 30-year-old patient presented with hallucinations and profound shock. He was initially misdiagnosed as having severe sepsis; once ingestions were considered, he was diagnosed as potentially having arsenic toxicity. SUMMARY: The clinical story reveals many instructional lessons that could aid in the evaluation and management of future patients. This man presented with large amounts of blue crystals around his nose and lips from inhaling and eating boric acid (an ant poison) so he could, as he put it, kill the ants "pouring into my mouth and nose and up into my brain." His profound pseudosepsis and sustained delirium were induced by co-ingestion of methamphetamine and a large quantity of boric acid. Delirium is a form of acute brain dysfunction that often is multifactorial in critical illness and, when seen in septic shock, is associated with prolonged mechanical ventilation, increased length of hospital stay, medical costs, higher mortality, and long-term cognitive impairment resembling dementia. Pseudosepsis is a noninfectious condition most commonly seen with ingestions such as salicylate (aspirin) toxicity. CONCLUSIONS: This report emphasizes the need to recognize agents that contain boric acid as an etiology of unexplained delirium and profound shock.

PAMAM Dendrimers Cross the Blood-Brain Barrier When Administered through the Carotid Artery in C57BL/6J Mice.

Drug delivery into the central nervous system (CNS) is challenging due to the blood-brain barrier (BBB) and drug delivery into the brain overcoming the BBB can be achieved using nanoparticles such as dendrimers. The conventional cationic dendrimers used are highly toxic. Therefore, the present study investigates the role of novel mixed surface dendrimers, which have potentially less toxicity and can cross the BBB when administered through the carotid artery in mice. In vitro experiments investigated the uptake of amine dendrimers (G1-NH2 and G4-NH2) and novel dendrimers (G1-90/10 and G4-90/10) by primary cortical cultures. In vivo experiments involved transplantation of G4-90/10 into mice through (1) invasive intracranial injections into the striatum; and (2) less invasive carotid injections. The animals were sacrificed 24-h and 1-week post-transplantations and their brains were analyzed. In vivo experiments proved that the G4-90/10 can cross the BBB when injected through the carotid artery and localize within neurons and glial cells. The dendrimers were found to migrate through the corpus callosum 1-week post intracranial injection. Immunohistochemistry showed that the migrating cells are the dendrimer-infected glial cells. Overall, our results suggest that poly-amidoamine (PAMAM) dendrimers may be used as a minimally invasive means to deliver biomolecules for treating neurological diseases or disorders.

Loneliness and sleep in everyday life: Using ecological momentary assessment to characterize the shape of daily loneliness experience.

BACKGROUND: Loneliness has been linked to an increased risk of sleep problems. Past research has largely relied on trait loneliness or daily recall loneliness when evaluating associations with sleep. OBJECTIVE: The present study extended this work by evaluating the patterns of loneliness throughout the day, including a daily average of all reports, a maximum value, and daily variation. These loneliness patterns predicted daily subjective and objective sleep measures to evaluate whether they provide unique insight to this relationship. METHODS: Undergraduate students (n = 71; 77% female; age 18-28) completed 2weeks of electronic surveys 4 times a day to assess loneliness. Each morning participants completed a diary of their prior night's sleep quality, as well as wore actigraphy devices to objectively assess sleep parameters. A total of 778 momentary surveys and 565days of actigraphy-assessed sleep data were collected. Multilevel models tested whether within-person daily aggregates of loneliness were associated with within-person daily sleep outcome variables. RESULTS: Subjective sleep duration, quality, and fatigue were significantly predicted by daily average loneliness. Subjective sleep latency, quality, and fatigue were significantly predicted by daily max loneliness. Only fatigue was significantly predicted by daily loneliness variability. No objective sleep measures were significantly predicted by daily loneliness measures. CONCLUSIONS: Patterns of daily loneliness focusing on central tendency (average) or intensity (max) were more consistently associated with subjective (but not objective) assessments of sleep than variability.

Computational strategies for cross-species knowledge transfer and translational biomedicine.

Research organisms provide invaluable insights into human biology and diseases, serving as essential tools for functional experiments, disease modeling, and drug testing. However, evolutionary divergence between humans and research organisms hinders effective knowledge transfer across species. Here, we review state-of-the-art methods for computationally transferring knowledge across species, primarily focusing on methods that utilize transcriptome data and/or molecular networks. We introduce the term "agnology" to describe the functional equivalence of molecular components regardless of evolutionary origin, as this concept is becoming pervasive in integrative data-driven models where the role of evolutionary origin can become unclear. Our review addresses four key areas of information and knowledge transfer across species: (1) transferring disease and gene annotation knowledge, (2) identifying agnologous molecular components, (3) inferring equivalent perturbed genes or gene sets, and (4) identifying agnologous cell types. We conclude with an outlook on future directions and several key challenges that remain in cross-species knowledge transfer.

Loss of ATP-Sensitive Potassium Channel Expression and Function in the Nervous System Decreases Opioid Sensitivity in a High-Fat Diet-Fed Mouse Model of Diet-Induced Obesity.

During diabetes progression, ß-cell dysfunction due to loss of potassium channels sensitive to ATP, known as KATP channels, occurs, contributing to hyperglycemia. The aim of this study was to investigate if KATP channel expression or activity in the nervous system was altered in a high-fat diet (HFD)-fed mouse model of diet-induced obesity. Expression of two KATP channel subunits, Kcnj11 (Kir6.2) and Abcc8 (SUR1), were decreased in the peripheral and central nervous system of mice fed HFD, which was significantly correlated with mechanical paw-withdrawal thresholds. HFD mice had decreased antinociception to systemic morphine compared with control diet (CON) mice, which was expected because KATP channels are downstream targets of opioid receptors. Mechanical hypersensitivity in HFD mice was exacerbated after systemic treatment with glyburide or nateglinide, KATP channel antagonists clinically used to control blood glucose levels. Upregulation of SUR1 and Kir6.2, through an adenovirus delivered intrathecally, increased morphine antinociception in HFD mice. These data present a potential link between KATP channel function and neuropathy during early stages of diabetes. There is a need for increased knowledge of how diabetes affects structural and molecular changes in the nervous system, including ion channels, to lead to the progression of chronic pain and sensory issues.

Induction of long-term hyperexcitability by memory-related cAMP signaling in isolated nociceptor cell bodies.

Persistent hyperactivity of nociceptors is known to contribute significantly to long-lasting sensitization and ongoing pain in many clinical conditions. It is often assumed that nociceptor hyperactivity is mainly driven by continuing stimulation from inflammatory mediators. We have tested an additional possibility: that persistent increases in excitability promoting hyperactivity can be induced by a prototypical cellular signaling pathway long known to induce late-phase long-term potentiation (LTP) of synapses in brain regions involved in memory formation. This cAMP-PKA-CREB-gene transcription-protein synthesis pathway was tested using whole-cell current clamp methods on small dissociated sensory neurons (primarily nociceptors) from dorsal root ganglia (DRGs) excised from previously uninjured ("naïve") rats. Six-hour treatment with the specific Gαs-coupled 5-HT4 receptor agonist, prucalopride, or with the adenylyl cyclase activator, forskolin, induced long-term hyperexcitability (LTH) in DRG neurons that manifested 12-24 hours later as action potential (AP) discharge (ongoing activity, OA) during artificial depolarization to -45 mV, a membrane potential that is normally subthreshold for AP generation. Prucalopride treatment also induced significant long-lasting depolarization of resting membrane potential (from -69 to -66 mV), enhanced depolarizing spontaneous fluctuations (DSFs) of membrane potential, and indications of reduced AP threshold and rheobase. LTH was prevented by co-treatment of prucalopride with inhibitors of PKA, CREB, gene transcription, and protein synthesis. As in the induction of synaptic memory, many other cellular signals are likely to be involved. However, the discovery that this prototypical memory induction pathway can induce nociceptor LTH, along with reports that cAMP signaling and CREB activity in DRGs can induce hyperalgesic priming, suggest that early, temporary, cAMP-induced transcriptional and translational mechanisms can induce nociceptor LTH that might last for long periods. An interesting possibility is that these mechanisms can also be reactivated by re-exposure to inflammatory mediators such as serotonin during subsequent challenges to bodily integrity, "reconsolidating" the cellular memory and thereby extending the duration of persistent nociceptor hyperexcitability.

Adherence and discontinuation of prescription cannabidiol for the management of seizure disorders at an integrated care center.

OBJECTIVE: Evaluate adherence, discontinuation rates, and reasons for non-adherence and discontinuation of prescription CBD during the 12-months post-initiation period at an integrated care center. METHODS: This was a prospective study of patients prescribed CBD by a neurology clinic provider with initial prescription fulfillment through the center's specialty pharmacy from January 2019 through April 2020. Baseline demographics and reasons for non-adherence and/or discontinuation were collected from the electronic health record and pharmacy claims history was used to calculate adherence using proportion of days covered (PDC). Patients were included in the PDC analysis if they had at least 3 fills during the study period. Non-adherence was defined as a PDC < 0.8. Descriptive statistics were used to summarize data with categorical variables represented as frequencies and percentages and continuous variables as medians and interquartile ranges (IQRs). RESULTS: We included 136 patients with a median age of 14 years (IQR 9 - 21). Most patients were white (n = 115, 85%), with a diagnosis of intractable epilepsy (n = 100, 74%). Among the 128 patients with 3 or more fills, the median PDC was 0.99 (IQR 0.95 - 1.00) with non-adherence seen in 6% (n = 8) of patients. The most common reason for non-adherence was side effects (n = 2, 25%). Prescription CBD was discontinued by 23% (n = 31) of patients with a median time to discontinuation of 117 days (IQR 68 - 216). The most common reason for discontinuation was major side effects (n = 12, 39%). The most common side effects leading to discontinuation were agitation/irritability (n = 4), mood changes (n = 4), aggressive behavior (n = 3), and increased seizure frequency (n = 3). CONCLUSION: Adherence to prescription CBD at an integrated care center was high with approximately 94% of patients considered adherent. Providers and pharmacists may improve adherence and discontinuation rates by educating patients on the timeline of response, potential side effects, and potential for dose adjustments.

Widespread latent hyperactivity of nociceptors outlasts enhanced avoidance behavior following incision injury.

Nociceptors with somata in dorsal root ganglia (DRGs) exhibit an unusual readiness to switch from an electrically silent state to a hyperactive state of tonic, nonaccommodating, low-frequency, irregular discharge of action potentials (APs). Ongoing activity (OA) during this state is present in vivo in rats months after spinal cord injury (SCI), and has been causally linked to SCI pain. OA induced by various neuropathic conditions in rats, mice, and humans is retained in nociceptor somata after dissociation and culturing, providing a powerful tool for investigating its mechanisms and functions. An important question is whether similar nociceptor OA is induced by painful conditions other than neuropathy. The present study shows that probable nociceptors dissociated from DRGs of rats subjected to postsurgical pain (induced by plantar incision) exhibit OA. The OA was most apparent when the soma was artificially depolarized to a level within the normal range of membrane potentials where large, transient depolarizing spontaneous fluctuations (DSFs) can approach AP threshold. This latent hyperactivity persisted for at least 3 weeks, whereas behavioral indicators of affective pain - hindpaw guarding and increased avoidance of a noxious substrate in an operant conflict test - persisted for 1 week or less. An unexpected discovery was latent OA in neurons from thoracic DRGs that innervate dermatomes distant from the injured tissue. The most consistent electrophysiological alteration associated with OA was enhancement of DSFs. Potential in vivo functions of widespread, low-frequency nociceptor OA consistent with these and other findings are to amplify hyperalgesic priming and to drive anxiety-related hypervigilance.

Second-sphere tuning of analogues for the ferric-hydroperoxoheme form of Mycobacterium tuberculosis MhuD.

Mycobacterium tuberculosis MhuD catalyzes the oxygenation of heme to mycobilin; experimental data presented here elucidates the novel hydroxylation reaction catalyzed by this enzyme. Analogues for the critical ferric-hydroperoxoheme (MhuD-heme-OOH) intermediate of this enzyme were characterized using UV/Vis absorption (Abs), circular dichroism (CD), and magnetic CD (MCD) spectroscopies. In order to extract electronic transition energies from these spectroscopic data, a novel global fitting model was developed for analysis of UV/Vis Abs, CD, and MCD data. A variant of MhuD was prepared, N7S, which weakens the affinity of heme-bound enzyme for a hydroperoxo analogue, azide, without significantly altering the protein secondary structure. Global fitting of spectroscopic data acquired in this study revealed that the second-sphere N7S substitution perturbs the electronic structure of two analogues for MhuD-heme-OOH: azide-inhibited MhuD (MhuD-heme-N3) and cyanide-inhibited MhuD (MhuD-heme-CN). The ground state electronic structures of MhuD-heme-N3 and MhuD-heme-CN were assessed using variable-temperature, variable-field MCD. Altogether, these data strongly suggest that there is a hydrogen bond between the Asn7 side-chain and the terminal oxygen of the hydroperoxo ligand in MhuD-heme-OOH. As discussed herein, this finding supports a novel hydroxylation reaction mechanism where the Asn7 side-chain guides a transient hydroxyl radical derived from homolysis of the OO bond in MhuD-heme-OOH to the ß- or δ-meso carbon of the porphyrin ligand yielding ß- or δ-meso-hydroxyheme, respectively.

Loss of ATP-sensitive channel expression and function decreases opioid sensitivity in a mouse model of type 2 diabetes.

During diabetes, ß-cell dysfunction due to loss of potassium channels sensitive to ATP, known as KATP channels occurs progressively over time contributing to hyperglycemia. KATP channels are additionally present in the central and peripheral nervous systems and are downstream targets of opioid receptor signaling. The aim of this study is to investigate if KATP channel expression or activity in the nervous system changes in diabetic mice and if morphine antinociception changes in mice fed a high fat diet (HFD) for 16 weeks compared to controls. Mechanical thresholds were also monitored before and after administration of glyburide or nateglinide, KATP channel antagonists, for four weeks. HFD mice have decreased antinociception to systemic morphine, which is exacerbated after systemic treatment with glyburide or nateglinide. HFD mice also have lower rotarod scores, decreased mobility in an open field test, and lower burrowing behavior compared to their control diet counterparts, which is unaffected by KATP channel antagonist delivery. Expression of KATP channel subunits, Kcnj11 (Kir6.2) and Abcc8 (SUR1), were decreased in the peripheral and central nervous system in HFD mice, which is significantly correlated with baseline paw withdrawal thresholds. Upregulation of SUR1 through an adenovirus delivered intrathecally increased morphine antinociception in HFD mice, whereas Kir6.2 upregulation improved morphine antinociception only marginally. Perspective: This article presents the potential link between KATP channel function and neuropathy during diabetes. There is a need for increased knowledge in how diabetes affects structural and molecular changes in the nervous system to lead to the progression of chronic pain and sensory issues.

A Novel 13q12 Microdeletion Associated with Familial Syndromic Corneal Opacification.

Progressive corneal opacification can result from multiple etiologies, including corneal dystrophies or systemic and genetic diseases. We describe a novel syndrome featuring progressive epithelial and anterior stromal opacification in a brother and sister and their mildly affected father, with all three family members having sensorineural hearing loss and two also with tracheomalacia/laryngomalacia. All carried a 1.2 Mb deletion at chromosome 13q12.11, with no other noteworthy co-segregating variants identified on clinical exome or chromosomal microarray. RNAseq analysis from an affected corneal epithelial sample from the proband's brother revealed downregulation of XPO4, IFT88, ZDHHC20, LATS2, SAP18, and EEF1AKMT1 within the microdeletion interval, with no notable effect on the expression of nearby genes. Pathway analysis showed upregulation of collagen metabolism and extracellular matrix (ECM) formation/maintenance, with no significantly down-regulated pathways. Analysis of overlapping deletions/variants demonstrated that deleterious variants in XPO4 were found in patients with laryngomalacia and sensorineural hearing loss, with the latter phenotype also being a feature of variants in the partially overlapping DFNB1 locus, yet none of these had reported corneal phenotypes. Together, these data define a novel microdeletion-associated syndromic progressive corneal opacification and suggest that a combination of genes within the microdeletion may contribute to ECM dysregulation leading to pathogenesis.

Robust normalization and transformation techniques for constructing gene coexpression networks from RNA-seq data.

BACKGROUND: Constructing gene coexpression networks is a powerful approach for analyzing high-throughput gene expression data towards module identification, gene function prediction, and disease-gene prioritization. While optimal workflows for constructing coexpression networks, including good choices for data pre-processing, normalization, and network transformation, have been developed for microarray-based expression data, such well-tested choices do not exist for RNA-seq data. Almost all studies that compare data processing and normalization methods for RNA-seq focus on the end goal of determining differential gene expression. RESULTS: Here, we present a comprehensive benchmarking and analysis of 36 different workflows, each with a unique set of normalization and network transformation methods, for constructing coexpression networks from RNA-seq datasets. We test these workflows on both large, homogenous datasets and small, heterogeneous datasets from various labs. We analyze the workflows in terms of aggregate performance, individual method choices, and the impact of multiple dataset experimental factors. Our results demonstrate that between-sample normalization has the biggest impact, with counts adjusted by size factors producing networks that most accurately recapitulate known tissue-naive and tissue-aware gene functional relationships. CONCLUSIONS: Based on this work, we provide concrete recommendations on robust procedures for building an accurate coexpression network from an RNA-seq dataset. In addition, researchers can examine all the results in great detail at https://krishnanlab.github.io/RNAseq_coexpression to make appropriate choices for coexpression analysis based on the experimental factors of their RNA-seq dataset.