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1.
J Allergy Clin Immunol Glob ; 3(3): 100250, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38699651

ABSTRACT

Background: Sublingual immunotherapy (SLIT) with 12 SQ house dust mile SLIT-tablet (HDM SLIT-tablet) for dust mite-induced perennial allergic rhinitis is reported as effective and safe. Although serious allergic reactions (SARs) and eosinophilic esophagitis (EoE) have infrequently occurred under trial conditions, the safety of HDM SLIT-tablet challenge under real-world conditions is unknown. Objective: Our aim was to estimate the incidence of SARs and EoE due to HDM SLIT-tablet challenge. Methods: Through use of administrative data from Kaiser Permanente Southern California, this prospective observational study identified patients newly administered HDM SLIT-tablet with follow-up until SLIT discontinuation or end of study. Suspected cases of SARs and EoE were detected by using International Classification of Diseases, 10th Revision, diagnosis and Current Procedural Terminology procedure codes and medication dispensing records. A 3-member clinical review committee of allergists adjudicated suspected reactions. The incidence rate of confirmed SARs and EoE per 1000 person years of exposure were determined. Results: A total of 521 patients (93.9% adult and 6.1% pediatric) were exposed to HDM SLIT-tablet challenge from January 2018 through May 2023, for 440.4 person years of exposure. The patients' average age (SD) was 39.3 (14.1) years, 58.7% were female, 44.3% were non-Hispanic White, 40.3% had asthma, and 15.0% had gastroesophageal reflux disease. A SAR occurred in 1 adult patient, and during initial HDM SLIT-tablet challenge, SARs occurred in 2 pediatric adolescents, for an overall incidence of 6.8 SARs per 1000 patient years (95% CI = 2.2-21.1). EoE occurred in 1 adult patient, for an overall incidence of 2.3 cases of EoE per 1000 patient years (95% CI = 0.3-16.1). Conclusions: This real-world study demonstrated that SARs and EoE were infrequent events with HDM SLIT-tablet use, supporting the safety of HDM SLIT-tablets and need for physician supervision with initial challenge.

2.
Article in English | MEDLINE | ID: mdl-38685477

ABSTRACT

Allergen immunotherapy is a recognized key therapeutic modality for the treatment of allergic respiratory disease - definitive studies have provided evidence-based data to demonstrate its effectiveness in allergic rhinitis and asthma due to the inhalation of proteinaceous allergic substances from specific seasonal pollens, dust mites, animal allergens, and certain mold spores. Over the ensuing decades, laboratory investigations, have provided objective evidence to demonstrate immunologic changes, including production of protective IgG antibody, suppression of IgE antibody, upregulation of regulatory T-cells, and an induction of a state of immune tolerance to the offending allergen(s). Tangential to this work were carefully designed clinical studies that defined allergen dose and duration of treatment, established the importance of preparing extracts with standardized allergens (or well-defined extracts) based on major protein moieties, utilized allergen provocation models to demonstrate efficacy superior to placebo. In the U.S., the use of subcutaneous immunotherapy (SCIT) extracts for allergen immunotherapy (AIT) was grandfathered in by the FDA based on expert literature review. In contrast, sublingual tablet immunotherapy (SLIT-tablets) underwent formal clinical development programs (Phase I-III clinical trials) that provided the necessary clinical evidence for safety and efficacy that led to regulatory agency approvals for the treatment of allergic rhinitis in properly characterized allergic patients. The allergy specialist's treatment options currently include traditional subcutaneous allergen immunotherapy and specific sublingual tablets approved for grass, ragweed, house dust mites, trees belonging to the birch homologous group, and Japanese Cedar. Tangential to this are sublingual drops (SLIT-drops) that are increasingly being used off-label (albeit not FDA-approved) in the U.S. This article will review the evidence-based literature supporting the use of these forms of AIT, as well as focus on several current controversies and gaps in our knowledge base that have relevance for the appropriate selection of patients for treatment with specific AIT.

3.
Science ; 384(6694): 438-446, 2024 Apr 26.
Article in English | MEDLINE | ID: mdl-38662831

ABSTRACT

Liver mitochondria play a central role in metabolic adaptations to changing nutritional states, yet their dynamic regulation upon anticipated changes in nutrient availability has remained unaddressed. Here, we found that sensory food perception rapidly induced mitochondrial fragmentation in the liver through protein kinase B/AKT (AKT)-dependent phosphorylation of serine 131 of the mitochondrial fission factor (MFFS131). This response was mediated by activation of hypothalamic pro-opiomelanocortin (POMC)-expressing neurons. A nonphosphorylatable MFFS131G knock-in mutation abrogated AKT-induced mitochondrial fragmentation in vitro. In vivo, MFFS131G knock-in mice displayed altered liver mitochondrial dynamics and impaired insulin-stimulated suppression of hepatic glucose production. Thus, rapid activation of a hypothalamus-liver axis can adapt mitochondrial function to anticipated changes of nutritional state in control of hepatic glucose metabolism.


Subject(s)
Food , Gluconeogenesis , Glucose , Liver , Membrane Proteins , Mitochondria, Liver , Mitochondrial Dynamics , Mitochondrial Proteins , Perception , Animals , Male , Mice , Gene Knock-In Techniques , Glucose/metabolism , Hypothalamus/metabolism , Insulin/metabolism , Liver/metabolism , Mice, Inbred C57BL , Mitochondria, Liver/metabolism , Mitochondrial Proteins/metabolism , Mitochondrial Proteins/genetics , Neurons/metabolism , Phosphorylation , Pro-Opiomelanocortin/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice, Transgenic
5.
Article in English | MEDLINE | ID: mdl-38307205

ABSTRACT

BACKGROUND: Allergic rhinitis with or without conjunctivitis can negatively impact many aspects of quality of life (QoL). The efficacy and safety of standardized quality (SQ) sublingual immunotherapy (SLIT) tablets have been confirmed across large clinical trials in adults with grass, tree, ragweed, and house dust mite (HDM) allergic rhinitis with or without conjunctivitis. OBJECTIVE: This pooled analysis investigates whether the reduction in symptom burden found across the clinical trials is supported by improvements in QoL. METHODS: A total of 11 phase II/III randomized placebo-controlled trials across the SQ grass, tree, ragweed, and HDM SLIT tablets (grass: N = 3179; ragweed: N = 767; tree: N = 634; HDM: N = 2221) were included. QoL was assessed using the standardized Rhinitis Quality of Life Questionnaire (RQLQ), with the exception of 3 grass trials, which used the nonstandardized version. The overall RQLQ scores were expressed as a mean of 7 domains. In the pooled analysis, treatment was used as fixed effect; and the trial, and the interaction between region/country and trial as random effects. RESULTS: The pooled analysis showed consistent and statistically significant improvements in overall RQLQ scores across all 4 SQ SLIT tablets versus placebo (pooled estimate [95% CI], P value-grass: -0.20 [-0.28 to -0.12], P < .001; tree: -0.42 [-0.58 to -0.26], P < .001; ragweed: -0.36 [-0.55 to -0.17], P < .001; HDM: -0.28 [-0.39 to -0.17], P < .001). Furthermore, significant improvements versus placebo for all 4 SQ SLIT tablets were seen across the 7 individual domains. CONCLUSIONS: The proven efficacy of SQ SLIT tablets to reduce symptoms across 4 of the most common respiratory allergens is supported by concurrent significant improvements in RQLQ scores overall and for all 7 domains.

6.
EMBO Rep ; 25(2): 704-724, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38263327

ABSTRACT

TFEB is a master regulator of autophagy, lysosome biogenesis, mitochondrial metabolism, and immunity that works primarily through transcription controlled by cytosol-to-nuclear translocation. Emerging data indicate additional regulatory interactions at the surface of organelles such as lysosomes. Here we show that TFEB has a non-transcriptional role in mitochondria, regulating the electron transport chain complex I to down-modulate inflammation. Proteomics analysis reveals extensive TFEB co-immunoprecipitation with several mitochondrial proteins, whose interactions are disrupted upon infection with S. Typhimurium. High resolution confocal microscopy and biochemistry confirms TFEB localization in the mitochondrial matrix. TFEB translocation depends on a conserved N-terminal TOMM20-binding motif and is enhanced by mTOR inhibition. Within the mitochondria, TFEB and protease LONP1 antagonistically co-regulate complex I, reactive oxygen species and the inflammatory response. Consequently, during infection, lack of TFEB specifically in the mitochondria exacerbates the expression of pro-inflammatory cytokines, contributing to innate immune pathogenesis.


Subject(s)
Autophagy , Inflammation , Humans , Inflammation/metabolism , Cytosol/metabolism , Active Transport, Cell Nucleus , Lysosomes/metabolism , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/genetics , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/metabolism , Mitochondrial Proteins/metabolism , ATP-Dependent Proteases/metabolism
7.
J Allergy Clin Immunol Pract ; 12(1): 85-95.e4, 2024 01.
Article in English | MEDLINE | ID: mdl-37972922

ABSTRACT

BACKGROUND: There is no consensus method to identify anaphylaxis in sublingual immunotherapy (SLIT) trials. Standardized Medical Dictionary for Regulatory Activities (MedDRA) queries (SMQs) are standardized groupings of MedDRA terms used in drug safety monitoring. OBJECTIVE: To develop a method to identify potential anaphylaxis in SLIT-tablet trials using SMQ searches and case definitions of anaphylaxis adopted from the National Institute of Allergy and Infectious Disease. METHODS: The SMQ search tool contained 2 criteria including treatment-emergent adverse events (AEs): (1) narrow MedDRA terms related to anaphylaxis and (2) all AEs with broad MedDRA terms from at least 2 of 3 categories (respiratory/skin/cardiovascular) occurring on the same day. Criteria were applied to a pooled data set of all subjects from 48 timothy grass, ragweed, house dust mite, and tree SLIT-tablet trials (SLIT-tablet, N = 8200; placebo, N = 7033). Additional search strategies were any treatment-emergent AE with MedDRA preferred term "hypersensitivity" and epinephrine administrations. Identified potential cases underwent blinded independent medical expert review. Nonanaphylaxis cases were designated local AEs or mild to moderate systemic reactions. RESULTS: Using the SMQ search tool and after subsequent medical review, 8 anaphylaxis cases were identified; 3 were considered treatment-related, resulting in a proportion of anaphylaxis cases/subject of 0.02% (2 of 8200) with SLIT-tablet and 0.01% (1 of 7033) with placebo. One additional anaphylaxis case related to SLIT-tablet was identified by the preferred term "hypersensitivity." The 3 anaphylaxis cases associated with SLIT-tablet treatment were not life-threatening. The epinephrine administration rate was 17 of 8200 (0.2%) with SLIT-tablet treatment and 2 of 7033 (0.03%) with placebo. CONCLUSIONS: SMQ search criteria for identifying potential anaphylaxis related to SLIT were developed. Anaphylaxis was rare for SLIT-tablets.


Subject(s)
Anaphylaxis , Rhinitis, Allergic , Sublingual Immunotherapy , Animals , Humans , Anaphylaxis/complications , Sublingual Immunotherapy/adverse effects , Sublingual Immunotherapy/methods , Pyroglyphidae , Epinephrine , Tablets , Allergens/therapeutic use , Rhinitis, Allergic/therapy , Treatment Outcome
8.
J Allergy Clin Immunol Pract ; 12(1): 13-22, 2024 01.
Article in English | MEDLINE | ID: mdl-37385447

ABSTRACT

Subcutaneous immunotherapy (SCIT) is a long-established treatment option for allergic rhinoconjunctivitis. Proper dosing of the allergens is critical for the efficacy and safety of SCIT. Of the hundreds of liquid allergen extracts in the United States, effective and well-tolerated SCIT dosing has only been established for a small number. Thus, SCIT dosing remains largely empiric and continues to be, by necessity, an art. To highlight the complexity of SCIT dosing, this review summarizes the historical and current landscape of U.S. allergen extracts, differences among U.S. and European allergen extracts, allergen selection for SCIT, considerations for compounding of allergen extract mixtures, and recommended dosing. As of 2021, 18 standardized allergen extracts are available in the United States; all other extracts remain unstandardized without characterization of allergen content or potency. U.S. allergen extracts differ from European extracts in formulation and potency characterization. There is no standardized methodology for SCIT allergen selection, and interpretation of allergen sensitization is not straightforward. Compounding of SCIT mixtures requires consideration of potential dilution effects, allergen cross-reactivity, proteolytic activity, and additives. Probable effective dose ranges for SCIT are recommended in U.S. allergy immunotherapy practice parameters, although there are few studies using U.S. extracts supporting these doses as therapeutic. In contrast, optimized doses of sublingual immunotherapy tablets have been confirmed in North American phase 3 trials. The SCIT dosing for each patient remains an art that requires clinical experience and consideration of polysensitization, tolerability, compounding of allergen extract mixtures, and the range of recommended doses within the context of extract potency variability.


Subject(s)
Hypersensitivity , Sublingual Immunotherapy , Humans , Allergens/administration & dosage , Desensitization, Immunologic/methods , Hypersensitivity/therapy , Injections, Subcutaneous , North America , Plant Extracts
9.
J Allergy Clin Immunol Pract ; 12(1): 32-44, 2024 01.
Article in English | MEDLINE | ID: mdl-37716529

ABSTRACT

Allergen immunotherapy (AIT) is broadly used all over the world as the only available disease-modifying treatment option. The aim of this experts' perspective is to address 7 important unmet needs for the further direction of AIT and to provide the readership with the authors' positions on these topics. An international group of experts in the field of AIT have formulated 7 important aspects for the future position of AIT, performed a current literature review, and proposed a consented position on these topics. The aspects discussed and consented by the authors include: (1) alternative routes of allergen application in AIT, (2) potential of recombinant vaccines, (3) the role of allergy diagnosis based on component-resolved diagnosis for AIT composition, (4) the impact of COVID-19 vaccination for further innovations in AIT, (5) potential of combining biologics to AIT, (6) future innovations in high-risk children/adolescents, and (7) the future regulatory position on AIT. Important unmet needs and topics for AIT have been addressed in this expert review. The authors' views and personal position on these 7 aspects have also been elaborated.


Subject(s)
COVID-19 Vaccines , Rhinitis, Allergic , Child , Adolescent , Humans , Rhinitis, Allergic/therapy , Desensitization, Immunologic , Allergens/therapeutic use , Forecasting
10.
Clin Exp Allergy ; 54(2): 120-129, 2024 02.
Article in English | MEDLINE | ID: mdl-37990117

ABSTRACT

BACKGROUND: Local application site reactions are common with sublingual allergy immunotherapy (AIT)-tablets for the treatment of allergic rhinitis/conjunctivitis (AR/C) and occasionally lead to treatment discontinuation. Because of the lower mast cell density in the vestibular mucosa than the sublingual area, vestibular AIT-tablet administration may result in fewer adverse events (AEs). This pilot study evaluated the tolerability of the vestibular administration route of AIT-tablets compared with the sublingual route in adult subjects with AR/C. METHODS: Adults (n = 164) aged 18-65 years with AR/C treated with daily birch pollen, grass pollen, ragweed pollen or house dust mite AIT in tablet form were randomized 1:1 to vestibular or sublingual administration for 28 days, followed by 28 days of sublingual administration only. The primary endpoint was the severity (mild, moderate, severe) of local treatment-related adverse events (TRAEs) during the first 28 days of treatment. RESULTS: During the first 28 days, the percentage of subjects in the vestibular and sublingual groups reporting mild TRAEs were 55.6% versus 50.6%, respectively; moderate TRAEs were 27.2% versus 30.1%; and severe TRAEs were 12.3% versus 6.0% (p = .16). In the vestibular group, 95.1% of the subjects experienced at least one TRAE during the first period versus 81.9% in the sublingual group (p = .01) and discontinuation rates due to AEs were higher (12.3% vs. 3.6%). CONCLUSION: The frequencies of subjects experiencing severe TRAEs, at least one TRAE, and discontinuations due to AEs at the initiation of AIT-tablets were numerically higher with vestibular administration than sublingual administration. Sublingual administration should remain the standard of care for subjects treated with AIT-tablets for AR/C.


Subject(s)
Conjunctivitis, Allergic , Rhinitis, Allergic, Seasonal , Rhinitis, Allergic , Sublingual Immunotherapy , Adult , Humans , Pilot Projects , Rhinitis, Allergic, Seasonal/therapy , Administration, Sublingual , Treatment Outcome , Rhinitis, Allergic/therapy , Sublingual Immunotherapy/adverse effects , Tablets , Allergens
11.
Allergy Asthma Proc ; 45(1): 33-36, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-38151733

ABSTRACT

Background: Most patients with allergic rhinitis/conjunctivitis (AR/C) are sensitized to more than one allergen. An ongoing question is the efficacy of single-allergen immunotherapy in patients who are polysensitized. Objective: To evaluate the efficacy and safety of grass, ragweed, tree, and house-dust mite (HDM) sublingual immunotherapy (SLIT) tablets in adults with AR/C who are mono- or polysensitized. Methods: Data from adults (ages ≥ 18 years) with AR/C who participated in phase III double-blind, placebo controlled field trials (four grass, two ragweed, two HDM, one tree) were included in the post hoc analyses. Efficacy was assessed by the total combined score (TCS) (sum of AR/C daily symptom and medication scores) during the entire pollen season for grass and tree trials, and peak pollen season for ragweed trials versus placebo. Efficacy for the HDM SLIT-tablet was assessed by the total combined rhinitis score (TCRS) (sum of rhinitis daily symptom and medication scores) during the last 8 weeks of treatment versus placebo. Results: For the grass SLIT-tablet, TCS improved by 20% (mean difference 1.33 [95% confidence interval {CI}, 0.44-2.22]) in the subjects who were monosensitized (n = 442) and 20% (mean difference 1.28 [95% CI, 0.90-1.67]) in the subjects who were polysensitized (n = 1857). For the ragweed SLIT-tablet, TCS improved by 19% (mean difference 1.72 [95% CI, -0.20 to 3.63]) in the subjects who were monosensitized (n = 115) and 27% (mean difference 2.27 [95% CI, 1.28-3.27]) in the subjects who were polysensitized (n = 528). For the tree SLIT-tablet, TCS improved by 54% (mean difference 4.65 [95% CI, 2.48-6.82]) in the subjects who were monosensitized (n = 138) and 34% (mean difference 2.51 [95% CI, 1.34-3.69]) in the subjects who were polysensitized (n = 437). For the HDM SLIT-tablet, TCRS improved by 20% (mean difference 1.24 [95% CI, 0.48-1.99]) in the subjects who were monosensitized (n = 468) and 17% (mean difference 0.85 [95% CI, 0.43-1.28]) in the subjects who were polysensitized (n = 1294). The overall safety profile was not qualitatively different between the subjects who were monosensitized and the subjects who were polysensitized. Conclusion: Grass, ragweed, tree, or HDM SLIT-tablet treatment is effective for the specific allergen in question in adults with AR/C and who are monosensitized or polysensitized. Targeting one relevant allergen with SLIT-tablets induces a clinical effect for that allergen in patients who were polysensitized.


Subject(s)
Conjunctivitis, Allergic , Conjunctivitis , Rhinitis, Allergic , Sublingual Immunotherapy , Adult , Animals , Humans , Allergens , Ambrosia , Conjunctivitis, Allergic/therapy , Dermatophagoides pteronyssinus , Poaceae , Pyroglyphidae , Rhinitis, Allergic/therapy , Rhinitis, Allergic/etiology , Sublingual Immunotherapy/adverse effects , Tablets , Treatment Outcome , Double-Blind Method
12.
Front Pediatr ; 11: 1244146, 2023.
Article in English | MEDLINE | ID: mdl-37859770

ABSTRACT

Allergic rhinoconjunctivitis (ARC) is a common disease that affects individuals of all ages. Pediatricians may be the first (and only) point of care for children with ARC. Sublingual immunotherapy (SLIT)-tablets are a convenient at-home, injection-free allergy immunotherapy option that can be used for the treatment of ARC. This paper provides a practical guide for pediatricians to aid in prescribing SLIT-tablets to children with ARC in North America. Topics include a summary of the available SLIT-tablets and their efficacy and safety, guidance on when SLIT-tablets are an appropriate option, and how to diagnose ARC and identify culprit allergens. Practical guidance is also provided through a proposed decision tree, a prescribing checklist and prescribing procedures, and suggested follow-up assessments.

13.
Mol Cell ; 83(19): 3470-3484.e8, 2023 Oct 05.
Article in English | MEDLINE | ID: mdl-37751741

ABSTRACT

Folding of newly synthesized proteins poses challenges for a functional proteome. Dedicated protein quality control (PQC) systems either promote the folding of nascent polypeptides at ribosomes or, if this fails, ensure their degradation. Although well studied for cytosolic protein biogenesis, it is not understood how these processes work for mitochondrially encoded proteins, key subunits of the oxidative phosphorylation (OXPHOS) system. Here, we identify dedicated hubs in proximity to mitoribosomal tunnel exits coordinating mitochondrial protein biogenesis and quality control. Conserved prohibitin (PHB)/m-AAA protease supercomplexes and the availability of assembly chaperones determine the fate of newly synthesized proteins by molecular triaging. The localization of these competing activities in the vicinity of the mitoribosomal tunnel exit allows for a prompt decision on whether newly synthesized proteins are fed into OXPHOS assembly or are degraded.


Subject(s)
Mitochondria , Triage , Mitochondria/genetics , Mitochondria/metabolism , Mitochondrial Proteins/metabolism , Ribosomes/metabolism , Protein Biosynthesis , Oxidative Phosphorylation , Ribosomal Proteins/metabolism
14.
EMBO J ; 42(18): e113256, 2023 09 18.
Article in English | MEDLINE | ID: mdl-37439264

ABSTRACT

Replication of the mitochondrial genome and expression of the genes it encodes both depend on a sufficient supply of nucleotides to mitochondria. Accordingly, dysregulated nucleotide metabolism not only destabilises the mitochondrial genome, but also affects its transcription. Here, we report that a mitochondrial nucleoside diphosphate kinase, NME6, supplies mitochondria with pyrimidine ribonucleotides that are necessary for the transcription of mitochondrial genes. Loss of NME6 function leads to the depletion of mitochondrial transcripts, as well as destabilisation of the electron transport chain and impaired oxidative phosphorylation. These deficiencies are rescued by an exogenous supply of pyrimidine ribonucleosides. Moreover, NME6 is required for the maintenance of mitochondrial DNA when the access to cytosolic pyrimidine deoxyribonucleotides is limited. Our results therefore reveal an important role for ribonucleotide salvage in mitochondrial gene expression.


Subject(s)
Genes, Mitochondrial , Pyrimidines , Pyrimidines/metabolism , Mitochondria/genetics , Mitochondria/metabolism , Nucleotides , DNA, Mitochondrial/genetics , DNA, Mitochondrial/metabolism , Ribonucleotides/genetics
15.
Cell Rep ; 42(4): 112332, 2023 04 25.
Article in English | MEDLINE | ID: mdl-37002921

ABSTRACT

The metabolic plasticity of mitochondria ensures cell development, differentiation, and survival. The peptidase OMA1 regulates mitochondrial morphology via OPA1 and stress signaling via DELE1 and orchestrates tumorigenesis and cell survival in a cell- and tissue-specific manner. Here, we use unbiased systems-based approaches to show that OMA1-dependent cell survival depends on metabolic cues. A metabolism-focused CRISPR screen combined with an integrated analysis of human gene expression data found that OMA1 protects against DNA damage. Nucleotide deficiencies induced by chemotherapeutic agents promote p53-dependent apoptosis of cells lacking OMA1. The protective effect of OMA1 does not depend on OMA1 activation or OMA1-mediated OPA1 and DELE1 processing. OMA1-deficient cells show reduced glycolysis and accumulate oxidative phosphorylation (OXPHOS) proteins upon DNA damage. OXPHOS inhibition restores glycolysis and confers resistance against DNA damage. Thus, OMA1 dictates the balance between cell death and survival through the control of glucose metabolism, shedding light on its role in cancerogenesis.


Subject(s)
Metalloendopeptidases , Peptide Hydrolases , Humans , DNA/metabolism , GTP Phosphohydrolases/metabolism , Metalloendopeptidases/metabolism , Mitochondria/metabolism , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Oxidative Phosphorylation , Peptide Hydrolases/metabolism
16.
Cell Metab ; 35(5): 786-806.e13, 2023 05 02.
Article in English | MEDLINE | ID: mdl-37075752

ABSTRACT

Autophagy represents a key regulator of aging and metabolism in sensing energy deprivation. We find that fasting in mice activates autophagy in the liver paralleled by activation of hypothalamic AgRP neurons. Optogenetic and chemogenetic activation of AgRP neurons induces autophagy, alters phosphorylation of autophagy regulators, and promotes ketogenesis. AgRP neuron-dependent induction of liver autophagy relies on NPY release in the paraventricular nucleus of the hypothalamus (PVH) via presynaptic inhibition of NPY1R-expressing neurons to activate PVHCRH neurons. Conversely, inhibiting AgRP neurons during energy deprivation abrogates induction of hepatic autophagy and rewiring of metabolism. AgRP neuron activation increases circulating corticosterone concentrations, and reduction of hepatic glucocorticoid receptor expression attenuates AgRP neuron-dependent activation of hepatic autophagy. Collectively, our study reveals a fundamental regulatory principle of liver autophagy in control of metabolic adaptation during nutrient deprivation.


Subject(s)
Hypothalamus , Neurons , Mice , Animals , Agouti-Related Protein/metabolism , Neurons/metabolism , Hypothalamus/metabolism , Liver/metabolism , Nutrients
17.
Brain ; 146(10): 4117-4131, 2023 10 03.
Article in English | MEDLINE | ID: mdl-37086482

ABSTRACT

Hereditary spastic paraplegia is a neurological condition characterized by predominant axonal degeneration in long spinal tracts, leading to weakness and spasticity in the lower limbs. The nicotinamide adenine dinucleotide (NAD+)-consuming enzyme SARM1 has emerged as a key executioner of axonal degeneration upon nerve transection and in some neuropathies. An increase in the nicotinamide mononucleotide/NAD+ ratio activates SARM1, causing catastrophic NAD+ depletion and axonal degeneration. However, the role of SARM1 in the pathogenesis of hereditary spastic paraplegia has not been investigated. Here, we report an enhanced mouse model for hereditary spastic paraplegia caused by mutations in SPG7. The eSpg7 knockout mouse carries a deletion in both Spg7 and Afg3l1, a redundant homologue expressed in mice but not in humans. The eSpg7 knockout mice recapitulate the phenotypic features of human patients, showing progressive symptoms of spastic-ataxia and degeneration of axons in the spinal cord as well as the cerebellum. We show that the lack of SPG7 rewires the mitochondrial proteome in both tissues, leading to an early onset decrease in mito-ribosomal subunits and a remodelling of mitochondrial solute carriers and transporters. To interrogate mechanisms leading to axonal degeneration in this mouse model, we explored the involvement of SARM1. Deletion of SARM1 delays the appearance of ataxic signs, rescues mitochondrial swelling and axonal degeneration of cerebellar granule cells and dampens neuroinflammation in the cerebellum. The loss of SARM1 also prevents endoplasmic reticulum abnormalities in long spinal cord axons, but does not halt the degeneration of these axons. Our data thus reveal a neuron-specific interplay between SARM1 and mitochondrial dysfunction caused by lack of SPG7 in hereditary spastic paraplegia.


Subject(s)
Spastic Paraplegia, Hereditary , Animals , Humans , Mice , Armadillo Domain Proteins/genetics , ATPases Associated with Diverse Cellular Activities , Axons/pathology , Cerebellum , Cytoskeletal Proteins/genetics , Metalloendopeptidases/genetics , Metalloendopeptidases/metabolism , NAD , Spastic Paraplegia, Hereditary/genetics
18.
Ann Allergy Asthma Immunol ; 130(6): 797-804.e2, 2023 06.
Article in English | MEDLINE | ID: mdl-36924936

ABSTRACT

BACKGROUND: The house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet is a treatment option for allergic rhinitis with/without conjunctivitis (AR/C) approved in adults worldwide and in adolescents in some countries. OBJECTIVE: To supplement existing adolescent HDM SLIT-tablet safety data by conducting the MT-18 trial in adolescents. METHODS: MT-18 (EudraCT:2020-000446-34) was a phase 3, open-label, single-arm, 28-day safety trial of daily HDM SLIT-tablet (12 SQ-HDM dose) in European adolescents (12-17 years) with HDM AR/C, with or without asthma. The primary end point was at least 1 treatment-emergent adverse event (TEAE). MT-18 results were compared with 12 SQ-HDM adolescent subpopulation data from previously described 1-year phase 3 trials conducted in North America (P001; clinicaltrials.gov:NCT01700192) or Japan (TO-203-3-2; JapicCTI:121848). RESULTS: No treatment-related anaphylaxis, epinephrine administrations, severe local swellings, severe mouth or throat edema, or eosinophilic esophagitis occurred in the trials. For MT-18 (N = 253), P001 (N adolescents = 189), and TO-203-3-2 (N adolescents = 206), the percentage of adolescents treated with 12 SQ-HDM reporting any TEAE was 88%, 95%, and 93%, respectively, and the percentage reporting any treatment-related AE (TRAE) was 86%, 93%, and 66%, respectively. The most common TRAEs were local application site reactions. Most TRAEs were mild in intensity and were typically experienced the first 1 to 2 days of treatment. There were no asthma-related TEAEs with the HDM SLIT-tablet. The safety profile appears similar between adolescents with or without asthma at baseline. CONCLUSION: The HDM SLIT-tablet was well tolerated in European, North American, and Japanese adolescents with HDM AR/C, indicating safety of the HDM SLIT-tablet is insensitive to age or geographic region. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: (P001: NCT01700192); EudraCT: (MT-18; 2020-000446-34); JapicCTI: (TO-203-3-2; 121848).


Subject(s)
Asthma , Conjunctivitis, Allergic , Conjunctivitis , Rhinitis, Allergic, Perennial , Rhinitis, Allergic , Sublingual Immunotherapy , Adolescent , Adult , Animals , Humans , Antigens, Dermatophagoides , Asthma/drug therapy , Conjunctivitis/chemically induced , Dermatophagoides pteronyssinus , Double-Blind Method , Pyroglyphidae , Rhinitis, Allergic, Perennial/drug therapy , Sublingual Immunotherapy/adverse effects , Sublingual Immunotherapy/methods , Tablets/therapeutic use , Treatment Outcome
19.
Nat Cell Biol ; 25(2): 246-257, 2023 02.
Article in English | MEDLINE | ID: mdl-36658222

ABSTRACT

Coenzyme Q (or ubiquinone) is a redox-active lipid that serves as universal electron carrier in the mitochondrial respiratory chain and antioxidant in the plasma membrane limiting lipid peroxidation and ferroptosis. Mechanisms allowing cellular coenzyme Q distribution after synthesis within mitochondria are not understood. Here we identify the cytosolic lipid transfer protein STARD7 as a critical factor of intracellular coenzyme Q transport and suppressor of ferroptosis. Dual localization of STARD7 to the intermembrane space of mitochondria and the cytosol upon cleavage by the rhomboid protease PARL ensures the synthesis of coenzyme Q in mitochondria and its transport to the plasma membrane. While mitochondrial STARD7 preserves coenzyme Q synthesis, oxidative phosphorylation function and cristae morphogenesis, cytosolic STARD7 is required for the transport of coenzyme Q to the plasma membrane and protects against ferroptosis. A coenzyme Q variant competes with phosphatidylcholine for binding to purified STARD7 in vitro. Overexpression of cytosolic STARD7 increases ferroptotic resistance of the cells, but limits coenzyme Q abundance in mitochondria and respiratory cell growth. Our findings thus demonstrate the need to coordinate coenzyme Q synthesis and cellular distribution by PARL-mediated STARD7 processing and identify PARL and STARD7 as promising targets to interfere with ferroptosis.


Subject(s)
Mitochondria , Ubiquinone , Biological Transport , Electron Transport , Mitochondria/metabolism , Mitochondrial Membranes/metabolism , Oxidation-Reduction , Ubiquinone/pharmacology , Ubiquinone/metabolism , Carrier Proteins/metabolism
20.
J Allergy Clin Immunol Pract ; 11(4): 1100-1115, 2023 04.
Article in English | MEDLINE | ID: mdl-36343885

ABSTRACT

Allergy/immunology specialists in the United States prescribing allergy immunotherapy (AIT) have placed a heavy value on practical experience and anecdotal evidence rather than research-based evidence. With the extensive research on AIT conducted in the last few decades, the time has come to better implement evidence-based medicine (EBM) for AIT. The goal of this review was to critically assess EBM for debated concepts in US AIT practice for respiratory allergies in the context and quality of today's regulatory standards. Debated topics reviewed were the efficacy and safety of AIT in various subgroups (eg, polyallergic patients, older patients, patients with asthma, and pregnant women), diagnosis topics (eg, skin prick test vs allergen-specific serum IgE, factors affecting skin prick tests, use of nasal or conjunctival allergen challenges, and telemedicine for diagnosis), and dosing topics (eg, optimal dosing for subcutaneous immunotherapy and sublingual immunotherapy tablets, US liquid allergen extract history, duration of treatment, and biomarkers of efficacy). In addition, EBM for patient-centered AIT issues (eg, adherence, use of practice guidelines, and pharmacoeconomics) and the approach to implementation of AIT EBM in future clinical practice were addressed. The EBM for each concept was briefly summarized, and when possible, a practical, concise recommendation was given.


Subject(s)
Asthma , Hypersensitivity , Pregnancy , Humans , Female , United States , Desensitization, Immunologic , Hypersensitivity/diagnosis , Hypersensitivity/therapy , Allergens , Asthma/therapy , Evidence-Based Medicine
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