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1.
Ann Rev Mar Sci ; 2024 Jun 19.
Article in English | MEDLINE | ID: mdl-38896540

ABSTRACT

The seasonal sea ice zone encompasses the region between the winter maximum and summer minimum sea ice extent. In both the Arctic and Antarctic, the majority of the ice cover can now be classified as seasonal. Here, we review the sea ice physics that governs the evolution of seasonal sea ice in the Arctic and Antarctic, spanning sea ice growth, melt, and dynamics and including interactions with ocean surface waves as well as other coupled processes. The advent of coupled wave-ice modeling and discrete-element modeling, together with improved and expanded satellite observations and field campaigns, has yielded advances in process understanding. Many topics remain in need of further investigation, including rheologies appropriate for seasonal sea ice, wave-induced sea ice fracture, welding for sea ice freeze-up, and the distribution of snow on seasonal sea ice. Future research should aim to redress biases (such as disparities in focus between the Arctic and Antarctic and between summer and winter processes) and connect observations to modeling across spatial scales.

2.
Shock ; 2024 May 23.
Article in English | MEDLINE | ID: mdl-38813923

ABSTRACT

BACKGROUND: The recruitment of neutrophils to sites of localized injury or infection is initiated by changes on the surface of endothelial cells located in proximity to tissue damage. Inflammatory mediators, such as TNF-α, increase surface expression of adhesive ligands and receptors on the endothelial surface to which neutrophils tether and adhere. Neutrophils then transit through the activated endothelium to reach sites of tissue injury with little lasting vascular injury. However, in cases of sepsis, the interaction of endothelial cells with highly activated neutrophils can cause damage vascular damage. The identification of molecules that are essential for neutrophil diapedesis may reveal targets of therapeutic opportunity for preservation of endothelial function in the presence of critical illness. We tested the hypothesis that inhibition of neutrophil ß1 integrin Very Late Antigen-3 (VLA-3; α3ß1) and/or inhibition of the Tetraspanin (TM4) family member CD151 would protect against neutrophil-mediated loss of endothelial function. METHODS: Blood was obtained from septic patients or healthy donors. Neutrophils were purified and aliquots were treated with/without proinflammatory molecules. Confluent Human Umbilical Vascular Endothelial Cells (HUVECs) were activated with tumor necrosis factor (TNF-α). Electric Cell Impedance Sensing (ECIS) was used to determine monolayer resistance over time after the addition of neutrophils that were treated with blocking antibodies against VLA-3 and/or CD151 or isotype controls. Groups (depending on relevancy) were analyzed by Mann-Whitney test, Wilcoxon test, or repeated measures one-way analysis of variance (ANOVA). RESULTS: Neutrophils from septic patients and neutrophils activated ex vivo reduced endothelial monolayer resistance to a greater extent than neutrophils from healthy donors. Antibody blockade of VLA-3 and/or CD151 significantly reduced activation-associated endothelial damage. Similar findings were demonstrated on fibronectin, collagen I, collagen IV and laminin suggesting that neutrophil surface VLA-3 and CD151 are responsible for endothelial damage regardless of substrata and are likely to be operative in all bodily tissues. CONCLUSION: This report identifies VLA-3 and CD151, on the activated human neutrophil that are responsible for damage to endothelial function. Targeting these molecules in vivo may demonstrate preservation of organ function during critical illness.

3.
Front Immunol ; 15: 1378610, 2024.
Article in English | MEDLINE | ID: mdl-38638436

ABSTRACT

Influenza A virus (IAV) infection in pregnancy resembles a preeclamptic phenotype characterised by vascular dysfunction and foetal growth retardation. Given that low dose aspirin (ASA) is safe in pregnancy and is used to prevent preeclampsia, we investigated whether ASA or NO-conjugated aspirin, NCX4016, resolve vascular inflammation and function to improve offspring outcomes following IAV infection in pregnant mice. Pregnant mice were intranasally infected with a mouse adapted IAV strain (Hkx31; 104 plaque forming units) and received daily treatments with either 200µg/kg ASA or NCX4016 via oral gavage. Mice were then culled and the maternal lungs and aortas collected for qPCR analysis, and wire myography was performed on aortic rings to assess endothelial and vascular smooth muscle functionality. Pup and placentas were weighed and pup growth rates and survival assessed. IAV infected mice had an impaired endothelial dependent relaxation response to ACh in the aorta, which was prevented by ASA and NCX4016 treatment. ASA and NCX4016 treatment prevented IAV dissemination and inflammation of the aorta as well as improving the pup placental ratios in utero, survival and growth rates at post-natal day 5. Low dose ASA is safe to use during pregnancy for preeclampsia and this study demonstrates that ASA may prove a promising treatment for averting the significant vascular complications associated with influenza infection during pregnancy.


Subject(s)
Aspirin/analogs & derivatives , Influenza A virus , Influenza, Human , Nitrates , Pre-Eclampsia , Vascular Diseases , Humans , Mice , Female , Pregnancy , Animals , Placenta , Aspirin/pharmacology , Inflammation , Aorta
4.
AIDS Behav ; 28(6): 2023-2033, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38489139

ABSTRACT

Minority stressors have been linked to HIV risk behaviors among gay, bisexual, queer, and other men who have sex with men (MSM). Committed partnerships are a key context for new HIV infections and coping with minority stress among MSM, but very little work has tested the minority stress-HIV risk link among male couples, and little is known about how processes within one's relationship may exacerbate or buffer this association. The present study examined links between minority stress (i.e., internalized stigma, microaggressions) and HIV transmission risk behaviors (i.e., condomless anal sex with outside partners, breaks in relationship agreements) among male couples, as well as relationship-based moderators (i.e., social support, dyadic coping) of these associations. An analytic sample of male couples from a large cohort study (analytic N = 410 individuals, 205 dyads) completed self-report measures of minority stress, relationship-based moderators, and HIV transmission risk behaviors which were submitted to moderated actor-partner interdependence models (APIMs). In many cases, coping with stress with one's partner buffered the minority stress-HIV transmission link risk. However, findings also suggested situations in which partners may overburden one another with coping, thus exacerbating HIV-related risk behaviors.


Subject(s)
HIV Infections , Homosexuality, Male , Minority Groups , Risk-Taking , Sexual Partners , Social Support , Stress, Psychological , Humans , Male , HIV Infections/psychology , HIV Infections/epidemiology , Stress, Psychological/psychology , Stress, Psychological/epidemiology , Adult , Sexual Partners/psychology , Homosexuality, Male/psychology , Homosexuality, Male/statistics & numerical data , Minority Groups/psychology , Minority Groups/statistics & numerical data , Sexual and Gender Minorities/psychology , Sexual and Gender Minorities/statistics & numerical data , Adaptation, Psychological , Middle Aged , Social Stigma , Sexual Behavior/psychology , Cohort Studies , Unsafe Sex/psychology , Unsafe Sex/statistics & numerical data , Family Characteristics
5.
Arch Biochem Biophys ; 755: 109966, 2024 May.
Article in English | MEDLINE | ID: mdl-38537870

ABSTRACT

Flavin disulfide reductases (FDRs) are FAD-dependent enzymes that transmit electrons from NAD(P)H to reduce specific oxidant substrate disulfides. These enzymes have been studied extensively, most particularly the paradigm examples: glutathione reductase and thioredoxin reductase. The common, though not universal, traits of the family include a tyrosine- or phenylalanine-gated binding pocket for NAD(P) nicotinamides adjacent to the FAD isoalloxazine re-face, and a disulfide stacked against the si-face of the isoalloxazine whose dithiol form is activated for subsequent exchange reactions by a nearby histidine acting as a base. This arrangement promotes transduction of the reducing equivalents for disulfide exchange relay reactions. From an observational standpoint the proximal parallel stacking of three redox moieties induces up to three opportunities for unique charge transfer interactions (NAD(P)H FAD, NAD(P)+•FADH2, and FAD•thiolate). In transient state, the charge transfer transitions provide discrete signals to assign reaction sequences. This review summarizes the lineage of observations for the FDR enzymes that have been extensively studied. Where applicable and in order to chart a consistent interpretation of the record, only data derived from studies that used anaerobic methods are cited. These data reveal a recurring theme for catalysis that is elaborated with specific additional functionalities for each oxidant substrate.

6.
Immunol Rev ; 322(1): 311-328, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38306168

ABSTRACT

Inborn errors of immunity (IEIs) encompass a diverse spectrum of genetic disorders that disrupt the intricate mechanisms of the immune system, leading to a variety of clinical manifestations. Traditionally associated with an increased susceptibility to recurrent infections, IEIs have unveiled a broader clinical landscape, encompassing immune dysregulation disorders characterized by autoimmunity, severe allergy, lymphoproliferation, and even malignancy. This review delves into the intricate interplay between IEIs and the JAK-STAT signaling pathway, a critical regulator of immune homeostasis. Mutations within this pathway can lead to a wide array of clinical presentations, even within the same gene. This heterogeneity poses a significant challenge, necessitating individually tailored therapeutic approaches to effectively manage the diverse manifestations of these disorders. Additionally, JAK-STAT pathway defects can lead to simultaneous susceptibility to both infection and immune dysregulation. JAK inhibitors, with their ability to suppress JAK-STAT signaling, have emerged as powerful tools in controlling immune dysregulation. However, questions remain regarding the optimal selection and dosing regimens for each specific condition. Hematopoietic stem cell transplantation (HSCT) holds promise as a curative therapy for many JAK-STAT pathway disorders, but this procedure carries significant risks. The use of JAK inhibitors as a bridge to HSCT has been proposed as a potential strategy to mitigate these risks.


Subject(s)
Immune System Diseases , Janus Kinase Inhibitors , Humans , Signal Transduction , Janus Kinase Inhibitors/therapeutic use , Janus Kinase Inhibitors/pharmacology , Janus Kinases/metabolism , STAT Transcription Factors/metabolism
7.
Diabetes Technol Ther ; 26(1): 33-39, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37855818

ABSTRACT

Objective: Connected insulin pens are creating opportunities for the millions of individuals with diabetes using multiple daily injections (MDI) therapy across the globe. Continuous glucose monitoring (CGM) data from connected insulin pens are revealing gaps and opportunities to significantly improve care for this population. In this article, we report real-world findings of the InPen™ smart insulin pen paired with CGM (InPen system), used by persons with type 1 diabetes (T1D) and type 2 diabetes (T2D). Methods: A retrospective cohort analysis was conducted with the real-world data collected from the InPen system of individuals (N = 3793 with T1D, N = 552 with T2D, and N = 808 unidentified) who used the system from January 01, 2020, to December 31, 2021. Diabetes management (e.g., missed and mistimed insulin dosing, mismatched food intake, and correction dose delivery) and glycemic outcomes were assessed. Results: In the overall and T1D populations, a dosing frequency of ≥3 doses per day and a missed dose frequency of <20% was associated with improved glycemia. In adults with T2D, missing <20% of doses was the significant factor determining improved glycemia. Conclusion: This analysis, integrating data from a smart insulin pen and CGM, provides insights into the impact of dosing behavior on glycemic outcomes and informs counseling strategies for the diabetes care team, through technologically advanced insulin management for those using MDI therapy.


Subject(s)
Diabetes Mellitus, Type 1 , Diabetes Mellitus, Type 2 , Adult , Humans , Insulin/therapeutic use , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Blood Glucose Self-Monitoring , Retrospective Studies , Blood Glucose , Insulin, Regular, Human/therapeutic use
8.
Front Mol Biosci ; 10: 1258333, 2023.
Article in English | MEDLINE | ID: mdl-37780207

ABSTRACT

Thioredoxin/glutathione reductase (TGR) from the platyhelminthic parasitic worms has recently been identified as a drug target for the treatment of schistosomiasis. Schistosomes lack catalase, and so are heavily reliant on the regeneration of reduced thioredoxin (Trx) and glutathione (GSH) to reduce peroxiredoxins that ameliorate oxidative damage from hydrogen peroxide generated by the host immune response. This study focuses on the characterization of the catalytic mechanism of Schistosoma mansoni TGR (SmTGR). Variant forms of SmTGR were studied to assign the function of residues that participate in the electron distribution chain within the enzyme. Using anaerobic transient state spectrophotometric methods, redox changes for the FAD and NADPH were observed and the function of specific residues was defined from observation of charge transfer absorption transitions that are indicative of specific complexations and redox states. The C159S variant prevented distribution of electrons beyond the flavin and as such did not accumulate thiolate-FAD charge transfer absorption. The lack of this absorption facilitated observation of a new charge transfer absorption consistent with proximity of NADPH and FAD. The C159S variant was used to confine electrons from NADPH at the flavin, and it was shown that NADPH and FAD exchange hydride in both directions and come to an equilibrium that yields only fractional FAD reduction, suggesting that both have similar reduction potentials. Mutation of U597 to serine resulted in sustained thiolate-FAD charge transfer absorption and loss of the ability to reduce Trx, indicating that the C596-U597 disulfide functions in the catalytic sequence to receive electrons from the C154 C159 pair and distribute them to Trx. No kinetic evidence for a loss or change in function associated with the distal C28-C31 disulfide was observed when the C31S variant reductive half-reaction was observed. The Y296A variant was shown to slow the rate of but increase extent of reduction of the flavin, and the dissociation of NADP+. The H571 residue was confirmed to be the residue responsible for the deprotonation of the C159 thiol, increasing its reactivity and generating the prominent thiolate-FAD charge transfer absorption that accumulates with oxidation of the flavin.

9.
Front Immunol ; 14: 1240552, 2023.
Article in English | MEDLINE | ID: mdl-37795093

ABSTRACT

Respiratory syncytial virus (RSV) commonly infects the upper respiratory tract (URT) of humans, manifesting with mild cold or flu-like symptoms. However, in infants and the elderly, severe disease of the lower respiratory tract (LRT) often occurs and can develop into chronic airway disease. A better understanding of how an acute RSV infection transitions to a LRT chronic inflammatory disease is critically important to improve patient care and long-term health outcomes. To model acute and chronic phases of the disease, we infected wild-type C57BL/6 and toll-like receptor 7 knockout (TLR7 KO) mice with RSV and temporally assessed nasal, airway and lung inflammation for up to 42 days post-infection. We show that TLR7 reduced viral titers in the URT during acute infection but promoted pronounced pathogenic and chronic airway inflammation and hyperreactivity in the LRT. This study defines a hitherto unappreciated molecular mechanism of lower respiratory pathogenesis to RSV, highlighting the potential of TLR7 modulation to constrain RSV pathology to the URT.


Subject(s)
Asthma , Respiratory Syncytial Virus Infections , Toll-Like Receptor 7 , Animals , Mice , Bronchi/pathology , Inflammation/pathology , Mice, Inbred C57BL , Toll-Like Receptor 7/genetics , Mice, Knockout
11.
Arch Sex Behav ; 52(5): 2097-2110, 2023 07.
Article in English | MEDLINE | ID: mdl-37351709

ABSTRACT

Research shows that, for different sex couples, individual levels of substance use are deleterious for relationship quality (e.g., satisfaction, intimate partner aggression), whereas dyadic concordance is usually protective. However, there has been no research on these effects among male couples, even though they show increased risk for substance use and certain indices of relationship distress (e.g., intimate partner aggression) compared to different sex couples. Male partners also display distinct similarity patterns and norms surrounding substance use, suggesting that there might be unique effects of substance use on relationship quality among this population. We conducted actor-partner interdependence models of substance use on relationship quality (intimate partner aggression, satisfaction) among a large sample of male dyads (N = 934 individuals, N = 467 dyads). Results suggested that there are novel actor, partner, and similarity effects that imply unique pathways to relationship well-being for male couples. These results are discussed in light of future clinical and empirical efforts. [NCT03186534 - 6/12/2017; NCT03284541 - 6/23/2017].


Subject(s)
Sexual Behavior , Substance-Related Disorders , Humans , Male , Aggression , Interpersonal Relations , Sexual Partners , Substance-Related Disorders/epidemiology , Young Adult
12.
Sci Data ; 10(1): 398, 2023 Jun 22.
Article in English | MEDLINE | ID: mdl-37349340

ABSTRACT

Snow plays an essential role in the Arctic as the interface between the sea ice and the atmosphere. Optical properties, thermal conductivity and mass distribution are critical to understanding the complex Arctic sea ice system's energy balance and mass distribution. By conducting measurements from October 2019 to September 2020 on the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, we have produced a dataset capturing the year-long evolution of the physical properties of the snow and surface scattering layer, a highly porous surface layer on Arctic sea ice that evolves due to preferential melt at the ice grain boundaries. The dataset includes measurements of snow during MOSAiC. Measurements included profiles of depth, density, temperature, snow water equivalent, penetration resistance, stable water isotope, salinity and microcomputer tomography samples. Most snowpit sites were visited and measured weekly to capture the temporal evolution of the physical properties of snow. The compiled dataset includes 576 snowpits and describes snow conditions during the MOSAiC expedition.

13.
Methods Enzymol ; 685: 373-403, 2023.
Article in English | MEDLINE | ID: mdl-37245908

ABSTRACT

Dihydropyrimidine dehydrogenase (DPD) catalyzes the reduction of the 5,6-vinylic bond of uracil and thymine with electrons from NADPH. The complexity of the enzyme belies the simplicity of the reaction catalyzed. To accomplish this chemistry DPD has two active sites that are ∼60Šapart, both of which house flavin cofactors, FAD and FMN. The FAD site interacts with NADPH, while the FMN site with pyrimidines. The distance between the flavins is spanned by four Fe4S4 centers. Though DPD has been studied for nearly 50years, it is only recently that the novel apects of its mechanism have been described. The primary reason for this is that the chemistry of DPD is not portrayed adequately by known descriptive steady-state mechanism categories. The highly chromophoric nature of the enzyme has recently been exploited in transient-state to document unexpected reaction sequences. Specifically, DPD undergoes reductive activation prior to catalytic turnover. Two electrons are taken up from NADPH and transmitted via the FAD and Fe4S4 centers to form the FAD•4(Fe4S4)•FMNH2 form of the enzyme. This form of the enzyme will only reduce pyrimidine substrates in the presence NADPH, establishing that hydride transfer to the pyrimidine precedes reductive reactivation that reinstates the active form of the enzyme. DPD is therefore the first flavoprotein dehydrogenase known to complete the oxidative half-reaction prior to the reductive half-reaction. Here we describe the methods and deduction that led to this mechanistic assignment.


Subject(s)
Dihydrouracil Dehydrogenase (NADP) , Uracil , Animals , Dihydrouracil Dehydrogenase (NADP)/genetics , Dihydrouracil Dehydrogenase (NADP)/metabolism , NADP/chemistry , Oxidation-Reduction , Catalytic Domain , Flavin-Adenine Dinucleotide/metabolism , Kinetics , Mammals/metabolism
14.
Arch Sex Behav ; 52(6): 2539-2560, 2023 08.
Article in English | MEDLINE | ID: mdl-37103633

ABSTRACT

Risky sexual behaviors (RSBs) incur large societal and personal costs. Despite widespread prevention efforts, RSBs and associated consequences (e.g., sexually transmitted infections) continue to rise. A proliferation of research has emerged on situational (e.g., alcohol use) and individual difference (e.g., impulsivity) factors to explain this rise, but these approaches assume an unrealistically static mechanism underlying RSB. Because this prior research has resulted in few compelling effects, we sought to innovate by examining the interaction of situation and individual differences in explaining RSBs. A large sample (N = 105) completed baseline reports of psychopathology and 30 daily diary reports of RSBs and associated contexts. These data were submitted to multilevel models including cross-level interactions to test a person-by-situation conceptualization of RSBs. Results suggested that RSBs are most strongly predicted from interactions of person- and situation-level factors in both protective and facilitative directions. These interactions outnumbered main effects and commonly included partner commitment as a central mechanism. These results point to theoretical and clinical gaps in preventing RSB and urge a departure from prior ways of conceptualizing sexual risk as a static outcome.


Subject(s)
Individuality , Sexually Transmitted Diseases , Humans , Sexual Behavior , Risk-Taking , Alcohol Drinking
15.
Biochemistry ; 62(9): 1497-1508, 2023 05 02.
Article in English | MEDLINE | ID: mdl-37071546

ABSTRACT

Thioredoxin/glutathione reductase from Schistosoma mansoni (SmTGR) catalyzes the reduction of both oxidized thioredoxin and glutathione with electrons from reduced nicotinamide adenine dinucleotide phosphate (NADPH). SmTGR is a drug target for the treatment of Schistosomiasis, an infection caused by Schistosoma platyhelminths residing in the blood vessels of the host. Schistosoma spp. are reliant on TGR enzymes as they lack catalase and so use reduced thioredoxin and glutathione to regenerate peroxiredoxins consumed in the detoxification of reactive oxygen species. SmTGR is a flavin adenine dinucleotide (FAD)-dependent enzyme, and we have used the flavin as a spectrophotometric reporter to observe the movement of electrons within the enzyme. The data show that NADPH fractionally reduces the active site flavin with an observed rate constant estimated in this study to be ∼3000 s-1. The flavin then reoxidizes by passing electrons at a similar rate to the proximal Cys159-Cys154 disulfide pair. The dissociation of NADP+ occurs with a rate of ∼180 s-1, which induces the deprotonation of Cys159, and this coincides with the accumulation of an intense FAD-thiolate charge transfer band. It is proposed that the electrons then pass to the Cys596-Cys597 disulfide pair of the associated subunit in the dimer with a net rate constant of ∼2 s-1. (Note: Cys597 is Sec597 in wild-type (WT) SmTGR.) From this position, the electrons can be passed to oxidized thioredoxin or further into the protein to reduce the Cys28-Cys31 disulfide pair of the originating subunit of the dimer. From the Cys28-Cys31 center, electrons can then pass to oxidized glutathione that has a binding site directly adjacent.


Subject(s)
Flavin-Adenine Dinucleotide , Schistosoma mansoni , Animals , Schistosoma mansoni/metabolism , Glutathione Reductase/metabolism , NADP/metabolism , Flavin-Adenine Dinucleotide/metabolism , Thioredoxin-Disulfide Reductase/metabolism , Glutathione/metabolism , Disulfides , Thioredoxins/metabolism , Oxidation-Reduction
16.
Br J Pharmacol ; 180(15): 2018-2034, 2023 08.
Article in English | MEDLINE | ID: mdl-36908040

ABSTRACT

BACKGROUND AND PURPOSE: Cardiovascular disease affects up to half of the patients with chronic obstructive pulmonary disease (COPD), exerting deleterious impact on health outcomes and survivability. Vascular endothelial dysfunction marks the onset of cardiovascular disease. The present study examined the effect of a potent NADPH Oxidase (NOX) inhibitor and free-radical scavenger, apocynin, on COPD-related cardiovascular disease. EXPERIMENTAL APPROACH: Male BALB/c mice were exposed to either room air (Sham) or cigarette smoke (CS) generated from 9 cigarettes·day-1 , 5 days a week for up to 24 weeks with or without apocynin treatment (5 mg·kg-1 ·day-1 , intraperitoneal injection). KEY RESULTS: Eight-weeks of apocynin treatment reduced airway neutrophil infiltration (by 42%) and completely preserved endothelial function and endothelial nitric oxide synthase (eNOS) availability against the oxidative insults of cigarette smoke exposure. These preservative effects were maintained up until the 24-week time point. 24-week of apocynin treatment markedly reduced airway inflammation (reduced infiltration of macrophage, neutrophil and lymphocyte), lung function decline (hyperinflation) and prevented airway collagen deposition by cigarette smoke exposure. CONCLUSION AND IMPLICATIONS: Limiting NOX activity may slow COPD progression and lower cardiovascular disease risk, particularly when signs of oxidative stress become evident.


Subject(s)
Cardiovascular Diseases , Cigarette Smoking , Pulmonary Disease, Chronic Obstructive , Vascular System Injuries , Mice , Animals , Male , Pulmonary Disease, Chronic Obstructive/drug therapy , Oxidative Stress , Lung
17.
eNeuro ; 10(2)2023 02.
Article in English | MEDLINE | ID: mdl-36725340

ABSTRACT

Temporal lobe epilepsy (TLE) is notoriously pharmacoresistant, and identifying novel therapeutic targets for controlling seizures is crucial. Long-range inhibitory neuronal nitric oxide synthase-expressing cells (LINCs), a population of hippocampal neurons, were recently identified as a unique source of widespread inhibition in CA1, able to elicit both GABAA-mediated and GABAB-mediated postsynaptic inhibition. We therefore hypothesized that LINCs could be an effective target for seizure control. LINCs were optogenetically activated for on-demand seizure intervention in the intrahippocampal kainate (KA) mouse model of chronic TLE. Unexpectedly, LINC activation at 1 month post-KA did not substantially reduce seizure duration in either male or female mice. We tested two different sets of stimulation parameters, both previously found to be effective with on-demand optogenetic approaches, but neither was successful. Quantification of LINCs following intervention revealed a substantial reduction of LINC numbers compared with saline-injected controls. We also observed a decreased number of LINCs when the site of initial insult (i.e., KA injection) was moved to the amygdala [basolateral amygdala (BLA)-KA], and correspondingly, no effect of light delivery on BLA-KA seizures. This indicates that LINCs may be a vulnerable population in TLE, regardless of the site of initial insult. To determine whether long-term circuitry changes could influence outcomes, we continued testing once a month for up to 6 months post-KA. However, at no time point did LINC activation provide meaningful seizure suppression. Altogether, our results suggest that LINCs are not a promising target for seizure inhibition in TLE.


Subject(s)
Epilepsy, Temporal Lobe , Epilepsy , Male , Mice , Female , Animals , Seizures/chemically induced , Hippocampus , Kainic Acid/toxicity , Disease Models, Animal , gamma-Aminobutyric Acid/pharmacology
18.
Arch Biochem Biophys ; 736: 109517, 2023 03 01.
Article in English | MEDLINE | ID: mdl-36681231

ABSTRACT

Dihydropyrimidine dehydrogenase (DPD) is a flavin dependent enzyme that catalyzes the reduction of the 5,6-vinylic bond of pyrimidines uracil and thymine with electrons from NADPH. DPD has two active sites that are separated by ∼60 Å. At one site NADPH binds adjacent to an FAD cofactor and at the other pyrimidine binds proximal to an FMN. Four Fe4S4 centers span the distance between these active sites. It has recently been established that the enzyme undergoes reductive activation prior to reducing the pyrimidine. In this initial process NADPH is oxidized at the FAD site and electrons are transmitted to the FMN via the Fe4S4 centers to yield the active state with a cofactor set of FAD•4(Fe4S4)•FMNH2. The catalytic chemistry of DPD can be studied in transient-state by observation of either NADPH consumption or charge transfer absorption associated with complexation of NADPH adjacent to the FAD. Here we have utilized both sets of absorption transitions to find evidence for specific additional aspects of the DPD mechanism. Competition for binding with NADP+ indicates that the two charge transfer species observed in activation/single turnover reactions arise from NADPH populating the FAD site before and after reductive activation. An additional charge transfer species is observed to accumulate at longer times when high NADPH concentrations are mixed with the enzyme•pyrimidine complex and this data can be modelled based on asymmetry in the homodimer. It was also shown that, like pyrimidines, dihydropyrimidines induce rapid reductive activation indicating that the reduced pyrimidine formed in turnover can stimulate the reinstatement of the active state of the enzyme. Investigation of the reverse reaction revealed that dihydropyrimidines alone can reductively activate the enzyme, albeit inefficiently. In the presence of dihydropyrimidine and NADP+ DPD will form NADPH but apparently without measurable reductive activation. Pyrimidines that have 5-substituent halogens were utilized to probe both reductive activation and turnover. The linearity of the Hammett plot based on the rate of hydride transfer to the pyrimidine establishes that, at least to the radius of an iodo-group, the 5-substituent volume does not have influence on the observed kinetics of pyrimidine reduction.


Subject(s)
Dihydrouracil Dehydrogenase (NADP) , Pyrimidines , Animals , Oxidation-Reduction , Dihydrouracil Dehydrogenase (NADP)/chemistry , NADP/metabolism , Spectrophotometry , Pyrimidines/metabolism , Kinetics , Flavin-Adenine Dinucleotide/chemistry , Mammals/metabolism
19.
J Allergy Clin Immunol ; 151(4): 1081-1095, 2023 04.
Article in English | MEDLINE | ID: mdl-36228738

ABSTRACT

BACKGROUND: In 2014, germline signal transducer and activator of transcription (STAT) 3 gain-of-function (GOF) mutations were first described to cause a novel multisystem disease of early-onset lymphoproliferation and autoimmunity. OBJECTIVE: This pivotal cohort study defines the scope, natural history, treatment, and overall survival of a large global cohort of patients with pathogenic STAT3 GOF variants. METHODS: We identified 191 patients from 33 countries with 72 unique mutations. Inclusion criteria included symptoms of immune dysregulation and a biochemically confirmed germline heterozygous GOF variant in STAT3. RESULTS: Overall survival was 88%, median age at onset of symptoms was 2.3 years, and median age at diagnosis was 12 years. Immune dysregulatory features were present in all patients: lymphoproliferation was the most common manifestation (73%); increased frequencies of double-negative (CD4-CD8-) T cells were found in 83% of patients tested. Autoimmune cytopenias were the second most common clinical manifestation (67%), followed by growth delay, enteropathy, skin disease, pulmonary disease, endocrinopathy, arthritis, autoimmune hepatitis, neurologic disease, vasculopathy, renal disease, and malignancy. Infections were reported in 72% of the cohort. A cellular and humoral immunodeficiency was observed in 37% and 51% of patients, respectively. Clinical symptoms dramatically improved in patients treated with JAK inhibitors, while a variety of other immunomodulatory treatment modalities were less efficacious. Thus far, 23 patients have undergone bone marrow transplantation, with a 62% survival rate. CONCLUSION: STAT3 GOF patients present with a wide array of immune-mediated disease including lymphoproliferation, autoimmune cytopenias, and multisystem autoimmunity. Patient care tends to be siloed, without a clear treatment strategy. Thus, early identification and prompt treatment implementation are lifesaving for STAT3 GOF syndrome.


Subject(s)
Immune System Diseases , Immunologic Deficiency Syndromes , Child , Humans , Autoimmunity/genetics , Cohort Studies , Gain of Function Mutation , Immunologic Deficiency Syndromes/genetics , Mutation , STAT3 Transcription Factor/genetics , Cell Proliferation , Lymphocytes
20.
J Sex Res ; 60(3): 359-367, 2023.
Article in English | MEDLINE | ID: mdl-35938904

ABSTRACT

Romantic relationships both buffer and exacerbate adverse health outcomes among bisexual individuals, so understanding determinants of their functioning may be key to correcting health inequities affecting this population. Binegativity (i.e., prejudiced attitudes about bisexuality) expressed from one's intimate partner has the potential to be uniquely impactful for bisexuals, but it is presently unknown how this experience might impact the quality (and therefore potential health promotive effects) of their romantic relationships. In addition, gender of one's current romantic partner may shape experiences of binegativity and relationship quality in important ways. The purpose of this report was to examine how binegativity from intimate partners impacts relationship functioning (i.e., relationship satisfaction and intimate partner aggression) among bisexual men (N = 113), and how the gender of one's partner might moderate this effect. Results suggested that binegativity is detrimentally associated with relationship satisfaction, and that bisexual men in relationships with women report more frequent intimate partner aggression. Furthermore, partner gender and binegativity showed novel interactive associations with intimate partner aggression, such that bisexual men in relationships with women tended to perpetrate less intimate partner aggression when experiencing more binegativity. These results are discussed with regard to future avenues for research into the health promotive benefits of relationships for bisexual individuals.


Subject(s)
Intimate Partner Violence , Sexual and Gender Minorities , Male , Humans , Female , Bisexuality , Sexual Behavior , Sexual Partners , Gender Identity
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