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1.
PLoS Biol ; 22(6): e3002641, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38833481

ABSTRACT

In utero exposure to maternal obesity programs increased obesity risk. Animal models show that programmed offspring obesity is preceded by hyperphagia, but the mechanisms that mediate these changes are unknown. Using a mouse model of maternal obesity, we observed increased intake of a high-fat diet (HFD) in offspring of obese mothers that precedes the development of obesity. Through small RNA sequencing, we identified programmed overexpression of hypothalamic miR-505-5p that is established in the fetus, lasts to adulthood and is maintained in hypothalamic neural progenitor cells cultured in vitro. Metabolic hormones and long-chain fatty acids associated with obesity increase miR-505-5p expression in hypothalamic neurons in vitro. We demonstrate that targets of miR-505-5p are enriched in fatty acid metabolism pathways and overexpression of miR-505-5p decreased neuronal fatty acid metabolism in vitro. miR-505-5p targets are associated with increased BMI in human genetic studies. Intra-cerebroventricular injection of miR-505-5p in wild-type mice increased HFD intake, mimicking the phenotype observed in offspring exposed to maternal obesity. Conversely, maternal exercise intervention in an obese mouse pregnancy rescued the programmed increase of hypothalamic miR-505-5p in offspring of obese dams and reduced HFD intake to control offspring levels. This study identifies a novel mechanism by which maternal obesity programs obesity in offspring via increased intake of high-fat foods.


Subject(s)
Diet, High-Fat , Fatty Acids , Hypothalamus , MicroRNAs , Obesity, Maternal , Animals , Female , Humans , Male , Mice , Pregnancy , Diet, High-Fat/adverse effects , Fatty Acids/metabolism , Hypothalamus/metabolism , Mice, Inbred C57BL , MicroRNAs/metabolism , MicroRNAs/genetics , Neurons/metabolism , Obesity/metabolism , Obesity/genetics , Obesity, Maternal/metabolism , Prenatal Exposure Delayed Effects/metabolism , Prenatal Exposure Delayed Effects/genetics
2.
EMBO Rep ; 24(6): e55556, 2023 06 05.
Article in English | MEDLINE | ID: mdl-37103980

ABSTRACT

Alzheimer's, Parkinson's and Huntington's diseases can be caused by mutations that enhance protein aggregation, but we still do not know enough about the molecular players of these pathways to develop treatments for these devastating diseases. Here, we screen for mutations that might enhance aggregation in Caenorhabditis elegans, to investigate the mechanisms that protect against dysregulated homeostasis. We report that the stomatin homologue UNC-1 activates neurohormonal signalling from the sulfotransferase SSU-1 in ASJ sensory/endocrine neurons. A putative hormone, produced in ASJ, targets the nuclear receptor NHR-1, which acts cell autonomously in the muscles to modulate polyglutamine repeat (polyQ) aggregation. A second nuclear receptor, DAF-12, functions oppositely to NHR-1 to maintain protein homeostasis. Transcriptomics analyses of unc-1 mutants revealed changes in the expression of genes involved in fat metabolism, suggesting that fat metabolism changes, controlled by neurohormonal signalling, contribute to protein homeostasis. Furthermore, the enzymes involved in the identified signalling pathway are potential targets for treating neurodegenerative diseases caused by disrupted protein homeostasis.


Subject(s)
Caenorhabditis elegans Proteins , Caenorhabditis elegans , Animals , Caenorhabditis elegans/genetics , Caenorhabditis elegans/metabolism , Caenorhabditis elegans Proteins/genetics , Caenorhabditis elegans Proteins/metabolism , Proteostasis , Lipid Metabolism/genetics , Receptors, Cytoplasmic and Nuclear/metabolism , Steroids/metabolism
3.
Phys Rev Lett ; 132(4): 046401, 2024 Jan 26.
Article in English | MEDLINE | ID: mdl-38335370

ABSTRACT

CeRh_{2}As_{2} is a new multiphase superconductor with strong suggestions for an additional itinerant multipolar ordered phase. The modeling of the low-temperature properties of this heavy-fermion compound requires a quartet Ce^{3+} crystal-field ground state. Here, we provide the evidence for the formation of such a quartet state using x-ray spectroscopy. Core-level photoelectron and x-ray absorption spectroscopy confirm the presence of Kondo hybridization in CeRh_{2}As_{2}. The temperature dependence of the linear dichroism unambiguously reveals the impact of Kondo physics for coupling the Kramer's doublets into an effective quasiquartet. Nonresonant inelastic x-ray scattering data find that the |Γ_{7}^{-}⟩ state with its lobes along the 110 direction of the tetragonal structure (xy orientation) contributes most to the multiorbital ground state of CeRh_{2}As_{2}.

4.
Int J Behav Nutr Phys Act ; 21(1): 43, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38654342

ABSTRACT

BACKGROUND: The development of validated "fit-for-purpose" rapid assessment tools to measure 24-hour movement behaviours in children aged 0-5 years is a research priority. This study evaluated the test-retest reliability and concurrent validity of the open-ended and closed-ended versions of the Movement Behaviour Questionnaire for baby (MBQ-B) and child (MBQ-C). METHODS: 300 parent-child dyads completed the 10-day study protocol (MBQ-B: N = 85; MBQ-C: N = 215). To assess validity, children wore an accelerometer on the non-dominant wrist (ActiGraph GT3X+) for 7 days and parents completed 2 × 24-hour time use diaries (TUDs) recording screen time and sleep on two separate days. For babies (i.e., not yet walking), parents completed 2 × 24-hour TUDs recording tummy time, active play, restrained time, screen time, and sleep on days 2 and 5 of the 7-day monitoring period. To assess test-retest reliability, parents were randomised to complete either the open- or closed-ended versions of the MBQ on day 7 and on day 10. Test-retest intraclass correlation coefficients (ICC's) were calculated using generalized linear mixed models and validity was assessed via Spearman correlations. RESULTS: Test-retest reliability for the MBQ-B was good to excellent with ICC's ranging from 0.80 to 0.94 and 0.71-0.93 for the open- and closed-ended versions, respectively. For both versions, significant positive correlations were observed between 24-hour diary and MBQ-B reported tummy time, active play, restrained time, screen time, and sleep (rho = 0.39-0.87). Test-retest reliability for the MBQ-C was moderate to excellent with ICC's ranging from 0.68 to 0.98 and 0.44-0.97 for the open- and closed-ended versions, respectively. For both the open- and closed-ended versions, significant positive correlations were observed between 24-hour diary and MBQ-C reported screen time and sleep (rho = 0.44-0.86); and between MBQ-C reported and device-measured time in total activity and energetic play (rho = 0.27-0.42). CONCLUSIONS: The MBQ-B and MBQ-C are valid and reliable rapid assessment tools for assessing 24-hour movement behaviours in infants, toddlers, and pre-schoolers. Both the open- and closed-ended versions of the MBQ are suitable for research conducted for policy and practice purposes, including the evaluation of scaled-up early obesity prevention programs.


Subject(s)
Parents , Sleep , Humans , Infant , Female , Male , Reproducibility of Results , Child, Preschool , Surveys and Questionnaires/standards , Sleep/physiology , Accelerometry/methods , Accelerometry/instrumentation , Child Behavior , Screen Time , Movement , Infant, Newborn , Sedentary Behavior , Exercise
5.
Pharm Res ; 2024 Oct 07.
Article in English | MEDLINE | ID: mdl-39375241

ABSTRACT

PURPOSE: For locally-acting dry powder inhalers (DPIs), developing novel analytical tools that are able to evaluate the state of aggregation may provide a better understanding of the impact of material properties and processing parameters on the in vivo performance. This study explored the utility of the Morphologically-Directed Raman Spectroscopy (MDRS) and dissolution as orthogonal techniques to assess microstructural equivalence of the aerosolized dose of DPIs collected with an aerosol collection device. METHODS: Commercial DPIs containing different strengths of Fluticasone Propionate (FP) and Salmeterol Xinafoate (SX) as monotherapy and combination products were sourced from different regions. These inhalers were compared with aerodynamic particle size distribution (APSD), dissolution, and MDRS studies. RESULTS: APSD testing alone might not be able to explain differences reported elsewhere in in vivo studies of commercial FP/SX drug products with different Advair® strengths and/or batches. Dissolution studies demonstrated different dissolution rates between Seretide™ 100/50 and Advair® 100/50, whereas Flixotide™ 100 and Flovent® 100 had similar dissolution rates between each other. These differences in dissolution profiles were supported by MDRS results: the dissolution rate is increased if the fraction of FP associated with high soluble components is increased. Principle component analysis was used to identify the agglomerate classes that better discriminate different products. CONCLUSIONS: MDRS and dissolution studies of the aerosolized dose of DPIs were successfully used as orthogonal techniques. This study highlights the importance of further assessing in vitro tools that are able to provide a bridge between material attributes or process parameters and in vivo performance.

6.
Curr Oncol Rep ; 26(5): 551-561, 2024 05.
Article in English | MEDLINE | ID: mdl-38598035

ABSTRACT

PURPOSE OF REVIEW: To provide insights into the role of peptide receptor radionuclide therapy (PRRT) in patients with advanced neuroendocrine tumors (NET) and an overview of possible strategies to combine PRRT with locoregional and systemic anticancer treatments. RECENT FINDINGS: Research on combining PRRT with other treatments encompasses a wide variety or treatments, both local (transarterial radioembolization) and systemic therapies, chemotherapy (i.e., capecitabine and temozolomide), targeted therapies (i.e., olaparib, everolimus, and sunitinib), and immunotherapies (e.g., nivolumab and pembrolizumab). Furthermore, PRRT shows promising first results as a treatment prior to surgery. There is great demand to enhance the efficacy of PRRT through combination with other anticancer treatments. While research in this area is currently limited, the field is rapidly evolving with numerous ongoing clinical trials aiming to address this need and explore novel therapeutic combinations.


Subject(s)
Neuroendocrine Tumors , Humans , Neuroendocrine Tumors/radiotherapy , Receptors, Peptide , Radiopharmaceuticals/therapeutic use , Radioisotopes/therapeutic use , Combined Modality Therapy
7.
Pediatr Nephrol ; 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-39352481

ABSTRACT

BACKGROUND: Urinary tract infections are prevalent among children and are responsible for a significant healthcare burden. Antibiotic therapy is the cornerstone of treatment, but the optimal treatment duration remains elusive. OBJECTIVES: This systematic review and meta-analysis aimed to explore the optimal duration of antibiotic therapy for urinary tract infection (UTI) in pediatric patients. DATA SOURCES: A comprehensive search was performed, including MEDLINE, Embase, and Cochrane Library databases. STUDY ELIGIBILITY CRITERIA: We included only randomized controlled trials (RCTs) comparing short-course (2 to 5 days) and standard-course (≥ 7 days) antibiotic treatment in patients < 18 years of age. STUDY APPRAISAL AND SYNTHESIS METHODS: We performed this systematic review and meta-analysis following Cochrane Collaboration recommendations using a random-effects model. Effect estimate was calculated using the risk ratio (RR) with 95% confidence interval (95% CI) for dichotomous and mean difference (MD) with 95% CI for continuous endpoints. Significance was regarded at p-value < 0.05. Statistical analysis was performed using Review Manager 5.4.1. RESULTS: Data from 12 RCTs, encompassing 1442 children, were included. Follow-up ranged from 1 to 12 months. The mean age was 5.9 years, with approximately 87% female patients. E. coli was the most common pathogen isolated from urine cultures. There was a significant difference in cure rates (RR 0.97; 95% CI 0.95-0.99; p = 0.01) between the groups when only studies that included febrile UTI were analyzed together, favoring 7 days or more of treatment, but with high heterogeneity. Otherwise, there was no significant difference in cure rates (RR 0.99; 95% CI 0.91-1.08; p = 0.80) in children with afebrile UTI or recurrence of UTI at any time in children with afebrile (RR 0.98; 95% CI 0.84-1.15; p = 0.80) or febrile UTI (RR 0.52; 95% CI 0.10-2.83; p = 0.45). Also, there was no significant difference in failure rates in children with urinary tract abnormalities and afebrile UTI (RR 0.79; 95% CI 0.47-1.32; p = 0.36), between the short- and the standard-course treatment groups. LIMITATIONS: This analysis was limited by the moderate heterogeneity and the small subgroup of children with urinary tract abnormalities, which could have underpowered our results. CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS: The primary outcome of this analysis suggests that a short course of antibiotic therapy is feasible in children with afebrile UTI, but more studies are warranted to safely establish an optimal treatment duration for children with febrile UTI. SYSTEMATIC REVIEW REGISTRATION NUMBER: The study protocol was registered in the PROSPERO platform under the number CRD42023489094.

8.
Support Care Cancer ; 32(2): 125, 2024 Jan 22.
Article in English | MEDLINE | ID: mdl-38252320

ABSTRACT

PURPOSE: To explore child and parent experiences of a 12-week goal-directed therapeutic exercise intervention in paediatric posterior fossa brain tumours survivors and to identify features of the program that influenced program adherence and acceptability. METHODS: Eleven interviews were conducted; five parent-child dyads (mothers = 83%) and one parent only (mean child age = 10.6 ± 3.0 years; 83% male). Posterior fossa brain tumour survivors, who participated in a weekly goal-directed exercise program for 12 weeks, completed semi-structured interviews to discuss their experience of the program. An inductive content analysis was undertaken. Interviews were transcribed, imported into NVivo and independently coded by two reviewers. Code and content categories were iteratively discussed and refined. RESULTS: Five content categories were generated: (1) perceived improvements, (2) program logistics, (3) activity selection, (4) connection with the therapist and (5) options for technology. All participants valued the tailored exercise program and described improvements in movement competence. Children and their parents discussed preferring home- and community-based locations and favoured face-to-face delivery. Occasionally, parents reported difficulty completing the home program due to low child motivation or family time restrictions. Multiple families suggested an interactive digital application would be an effective delivery channel for the supplemental home-based program. CONCLUSION: A goal-directed exercise program delivered at home and in community-based locations was considered valuable and helpful for improving movement competence in paediatric survivors of posterior fossa brain tumour. TRIAL REGISTRATION: ACTRN12619000841178 June 12, 2019.


Subject(s)
Brain Neoplasms , Motivation , Male , Humans , Child , Female , Adolescent , Goals , Exercise Therapy , Brain Neoplasms/therapy , Survivors
9.
BMC Ophthalmol ; 24(1): 356, 2024 Aug 20.
Article in English | MEDLINE | ID: mdl-39164678

ABSTRACT

BACKGROUND: The Point-of-Care Diabetic Retinopathy Examination Program (POCDREP) was initiated in 2015 at the University of Pittsburgh/UPMC in response to low diabetic retinopathy (DR) examination rates, a condition affecting a quarter of people with diabetes mellitus (PwDM) and leading to blindness. Early detection and treatment are critical with DR prevalence projected to triple by 2050. Approximately, half of PwDM in the U.S. undergo yearly examinations, and there are reported varying follow-up rates with eye care professionals, with limited data on the factors influencing these trends. POCDREP aimed to address screening and follow-up gap, partnering with diverse healthcare entities, including primary care sites, free clinics, and federally qualified health centers. METHODS: A non-concurrent retrospective cohort study spanning 2015-2018 examined data using electronic health records of patients who underwent retinal imaging. Imaging was performed using 31 cameras across various settings, with results interpreted by ophthalmologists. Follow-up recommendations were made for cases with vision-threatening DR (VTDR), incidental findings, or indeterminate results. Factors influencing follow-up were analyzed, including demographic, clinical, and imaging-related variables. We assessed the findings at follow-up of patients with indeterminate results. RESULTS: Out of 7,733 examinations (6,242 patients), 32.25% were recommended for follow-up. Among these, 5.57% were classified as having VTDR, 14.34% had other ocular findings such as suspected glaucoma and age-related macular degeneration (AMD), and 12.13% were indeterminate. Of those recommended for follow-up, only 30.87% were assessed by eye care within six months. Older age, marriage, and severe DR were associated with higher odds of following up. Almost two thirds (64.35%) of the patients with indeterminate exams were found with a vision-threatening disease at follow-up. CONCLUSION: The six-month follow-up rate was found to be suboptimal. Influential factors for follow-up included age, marital status, and the severity of diabetic retinopathy (DR). While the program successfully identified a range of ocular conditions, screening initiatives must extend beyond mere disease detection. Ensuring patient follow-up is crucial to DR preventing programs mission. Recommended strategies to improve follow-up adherence include education, incentives, and personalized interventions. Additional research is necessary to pinpoint modifiable factors that impact adherence and to develop targeted interventions.


Subject(s)
Diabetic Retinopathy , Humans , Retrospective Studies , Diabetic Retinopathy/diagnosis , Diabetic Retinopathy/epidemiology , Male , Middle Aged , Female , Follow-Up Studies , Aged , Pennsylvania/epidemiology , Point-of-Care Systems , Adult
10.
BMC Public Health ; 24(1): 890, 2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38528500

ABSTRACT

BACKGROUND: The early years is a critical stage to establish optimal nutrition and movement behaviours. Community playgroups are a relaxed environment for parents with a focus on social connection and supporting parents in their role as 'First Teachers'. Playgroups are therefore an opportunistic setting to promote health behaviours in the early years. To support parents with young children around healthy lifestyle behaviours, the Healthy Conversations @ Playgroup program was delivered in urban and regional areas, across three Australian jurisdictions between 2021-2023. OBJECTIVE: This qualitative evaluation aimed to understand how the Healthy Conversations @ Playgroup program was experienced by parents, playgroup coordinators and peer facilitators. DESIGN: Semi-structured virtual interviews and focus groups were conducted with parents, playgroup coordinators (i.e., person responsible for coordinating the playgroup) and peer facilitators (i.e., trained facilitator for the program) that participated in the Healthy Conversations @ Playgroup study. Transcripts were analysed following a thematic analysis approach. RESULTS: Twenty-eight playgroup parents, coordinators or peer facilitators participated in one of 8 focus groups or 5 interviews. Four themes were developed: Program strengths and challenges; Setting strengths and challenges; Factors that impact program delivery; Participant's suggestions for future program delivery. CONCLUSIONS: The Healthy Conversations @ Playgroup program was valued by parents, providing validation and normalisation of parenting practices, and fostering a shared experience of parenting. Playgroups are a convenient setting for families to attend. The dynamic and distracting nature of the playgroup setting were carefully considered when designing the program. Strategies to further enhance program engagement could include use of coordinator or parent champions, tailored delivery, and extending the reach to other family members. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12621000055808, registered 22 January 2021, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=380890.


Subject(s)
Health Promotion , Parents , Child, Preschool , Humans , Australia , Health Behavior , Parenting , Qualitative Research , Clinical Trials as Topic
11.
Article in English | MEDLINE | ID: mdl-39012303

ABSTRACT

PURPOSE: To examine the long-term outcome of the staged excision via the square procedure for the treatment of periocular thin cutaneous melanoma. METHODS: A retrospective chart review of 95 periocular cutaneous melanoma-in-situ and microinvasive melanoma tumors that were treated with the square procedure between April 1, 1994 and December 31, 2018 at the University of Michigan. Demographic and clinical data were evaluated. RESULTS: Of 95 cases, 19 (20%) were atypical junctional melanocytic proliferation with features of early melanoma-in-situ, 63 (66.3%) were melanoma-in-situ and 13 (13.7) were microinvasive melanoma with Breslow depth less than 1 mm. Tumor-free margins were achieved with a median margin of 10 mm (range 5-40 mm). Most cases (68.4%) required multiple excision stages. Surgical revision was necessary in 17.9% of cases and was associated with larger defect size. Local recurrence was noted in 8 patients (8.4%) at a median of 42 months postreconstruction. No tumor characteristics were found to predict recurrence. CONCLUSIONS: The square procedure for periocular melanoma offers an 8.4% recurrence rate, consistent with literature reports on similar staged excision approaches. The staged excision provides an excellent option for comprehensive margin review and tumor control with acceptable cosmetic results after reconstruction.

12.
J Physiol ; 601(9): 1521-1542, 2023 05.
Article in English | MEDLINE | ID: mdl-36314992

ABSTRACT

The DEG/ENaC family of ion channels was defined based on the sequence similarity between degenerins (DEG) from the nematode Caenorhabditis elegans and subunits of the mammalian epithelial sodium channel (ENaC), and also includes a diverse array of non-voltage-gated cation channels from across animal phyla, including the mammalian acid-sensing ion channels (ASICs) and Drosophila pickpockets. ENaCs and ASICs have wide ranging medical importance; for example, ENaCs play an important role in respiratory and renal function, and ASICs in ischaemia and inflammatory pain, as well as being implicated in memory and learning. Electrophysiological approaches, both in vitro and in vivo, have played an essential role in establishing the physiological properties of this diverse family, identifying an array of modulators and implicating them in an extensive range of cellular functions, including mechanosensation, acid sensation and synaptic modulation. Likewise, genetic studies in both invertebrates and vertebrates have played an important role in linking our understanding of channel properties to function at the cellular and whole animal/behavioural level. Drawing together genetic and physiological evidence is essential to furthering our understanding of the precise cellular roles of DEG/ENaC channels, with the diversity among family members allowing comparative physiological studies to dissect the molecular basis of these diverse functions.


Subject(s)
Acid Sensing Ion Channels , Epithelial Sodium Channels , Animals , Acid Sensing Ion Channels/genetics , Epithelial Sodium Channels/metabolism , Signal Transduction , Caenorhabditis elegans/metabolism , Drosophila/metabolism , Mammals/metabolism
13.
J Physiol ; 601(9): 1625-1653, 2023 05.
Article in English | MEDLINE | ID: mdl-36200489

ABSTRACT

Acid-sensing ion channels (ASICs) are members of the diverse family of degenerin/epithelial sodium channels (DEG/ENaCs). They perform a wide range of physiological roles in healthy organisms, including in gut function and synaptic transmission, but also play important roles in disease, as acidosis is a hallmark of painful inflammatory and ischaemic conditions. We performed a screen for acid sensitivity on all 30 subunits of the Caenorhabditis elegans DEG/ENaC family using two-electrode voltage clamp in Xenopus oocytes. We found two groups of acid-sensitive DEG/ENaCs characterised by being either inhibited or activated by increasing proton concentrations. Three of these acid-sensitive C. elegans DEG/ENaCs were activated by acidic pH, making them functionally similar to the vertebrate ASICs. We also identified three new members of the acid-inhibited DEG/ENaC group, giving a total of seven additional acid-sensitive channels. We observed sensitivity to the anti-hypertensive drug amiloride as well as modulation by the trace element zinc. Acid-sensitive DEG/ENaCs were found to be expressed in both neurons and non-neuronal tissue, highlighting the likely functional diversity of these channels. Our findings provide a framework to exploit the C. elegans channels as models to study the function of these acid-sensing channels in vivo, as well as to study them as potential targets for anti-helminthic drugs. KEY POINTS: Acidosis plays many roles in healthy physiology, including synaptic transmission and gut function, but is also a key feature of inflammatory pain, ischaemia and many other conditions. Cells monitor acidosis of their surroundings via pH-sensing channels, including the acid-sensing ion channels (ASICs). These are members of the degenerin/epithelial sodium channel (DEG/ENaC) family, along with, as the name suggests, vertebrate ENaCs and degenerins of the roundworm Caenorhabditis elegans. By screening all 30 C. elegans DEG/ENaCs for pH dependence, we describe, for the first time, three acid-activated members, as well as three additional acid-inhibited channels. We surveyed both groups for sensitivity to amiloride and zinc; like their mammalian counterparts, their currents can be blocked, enhanced or unaffected by these modulators. Likewise, they exhibit diverse ion selectivity. Our findings underline the diversity of acid-sensitive DEG/ENaCs across species and provide a comparative resource for better understanding the molecular basis of their function.


Subject(s)
Caenorhabditis elegans , Epithelial Sodium Channels , Animals , Epithelial Sodium Channels/physiology , Degenerin Sodium Channels/physiology , Acid Sensing Ion Channels , Amiloride/pharmacology , Mammals
14.
J Biol Chem ; 298(5): 101925, 2022 05.
Article in English | MEDLINE | ID: mdl-35413287

ABSTRACT

Conditional proteolytic degradation is an irreversible and highly regulated process that fulfills crucial regulatory functions in all organisms. As proteolytic targets tend to be critical metabolic or regulatory proteins, substrates are targeted for degradation only under appropriate conditions through the recognition of an amino acid sequence referred to as a "degron". DEAD-box RNA helicases mediate all aspects of RNA metabolism, contributing to cellular fitness. However, the mechanism by which abiotic-stress modulation of protein stability regulates bacterial helicase abundance has not been extensively characterized. Here, we provide in vivo evidence that proteolytic degradation of the cyanobacterial DEAD-box RNA helicase CrhR is conditional, being initiated by a temperature upshift from 20 to 30 °C in the model cyanobacterium, Synechocystis sp. PCC 6803. We show degradation requires a unique, highly conserved, inherently bipartite degron located in the C-terminal extension found only in CrhR-related RNA helicases in the phylum Cyanobacteria. However, although necessary, the degron is not sufficient for proteolysis, as disruption of RNA helicase activity and/or translation inhibits degradation. These results suggest a positive feedback mechanism involving a role for CrhR in expression of a crucial factor required for degradation. Furthermore, AlphaFold structural prediction indicated the C-terminal extension is a homodimerization domain with homology to other bacterial RNA helicases, and mass photometry data confirmed that CrhR exists as a dimer in solution at 22 °C. These structural data suggest a model wherein the CrhR degron is occluded at the dimerization interface but could be exposed if dimerization was disrupted by nonpermissive conditions.


Subject(s)
DEAD-box RNA Helicases , Synechocystis , DEAD-box RNA Helicases/metabolism , Proteolysis , RNA, Bacterial/metabolism , Synechocystis/enzymology , Synechocystis/genetics
15.
Mol Pharm ; 20(11): 5690-5700, 2023 11 06.
Article in English | MEDLINE | ID: mdl-37773975

ABSTRACT

To assess bioequivalence of locally acting suspension-based nasal sprays, the U.S. FDA currently recommends a weight-of-evidence approach. In addition to in vitro and human pharmacokinetic (PK) studies, this includes a comparative clinical endpoint study to ensure equivalent bioavailability of the active pharmaceutical ingredient (API) at the site of action. The present study aimed to assess, within an in vitro/in vivo correlation paradigm, whether PK studies and dissolution kinetics are sensitive to differences in drug particle size for a locally acting suspension-based nasal spray product. Two investigational suspension-based nasal formulations of mometasone furoate (MF-I and MF-II; delivered dose: 180 µg) differed in API particle size and were compared in a single-center, double-blind, single-dose, randomized, two-way crossover PK study in 44 healthy subjects with oral charcoal block. Morphology-directed Raman spectroscopy yielded volume median diameters of 3.17 µm for MF-I and 5.50 µm for MF-II, and dissolution studies showed that MF-II had a slower dissolution profile than MF-I. The formulation with larger API particles (MF-II) showed a 45% smaller Cmax and 45% smaller AUC0-inf compared to those of MF-I. Systemic bioavailability of MF-I (2.20%) and MF-II (1.18%) correlated well with the dissolution kinetics, with the faster dissolving formulation yielding the higher bioavailability. This agreement between pharmacokinetics and dissolution kinetics cross-validated both methods and supported their use in assessing potential differences in slowly dissolving suspension-based nasal spray products.


Subject(s)
Nasal Sprays , Humans , Biological Availability , Mometasone Furoate/pharmacokinetics , Particle Size , Therapeutic Equivalency , Double-Blind Method , Cross-Over Studies
16.
Nature ; 550(7677): 519-523, 2017 10 26.
Article in English | MEDLINE | ID: mdl-29045391

ABSTRACT

Recent studies on the controllability of complex systems offer a powerful mathematical framework to systematically explore the structure-function relationship in biological, social, and technological networks. Despite theoretical advances, we lack direct experimental proof of the validity of these widely used control principles. Here we fill this gap by applying a control framework to the connectome of the nematode Caenorhabditis elegans, allowing us to predict the involvement of each C. elegans neuron in locomotor behaviours. We predict that control of the muscles or motor neurons requires 12 neuronal classes, which include neuronal groups previously implicated in locomotion by laser ablation, as well as one previously uncharacterized neuron, PDB. We validate this prediction experimentally, finding that the ablation of PDB leads to a significant loss of dorsoventral polarity in large body bends. Importantly, control principles also allow us to investigate the involvement of individual neurons within each neuronal class. For example, we predict that, within the class of DD motor neurons, only three (DD04, DD05, or DD06) should affect locomotion when ablated individually. This prediction is also confirmed; single cell ablations of DD04 or DD05 specifically affect posterior body movements, whereas ablations of DD02 or DD03 do not. Our predictions are robust to deletions of weak connections, missing connections, and rewired connections in the current connectome, indicating the potential applicability of this analytical framework to larger and less well-characterized connectomes.


Subject(s)
Caenorhabditis elegans/cytology , Caenorhabditis elegans/physiology , Connectome , Nerve Net/cytology , Nerve Net/physiology , Neurons/physiology , Animals , Lasers , Locomotion/physiology , Motor Neurons/cytology , Motor Neurons/physiology , Neurons/classification
17.
Diabetologia ; 65(12): 2132-2145, 2022 12.
Article in English | MEDLINE | ID: mdl-36112170

ABSTRACT

AIMS/HYPOTHESIS: Metformin is increasingly used to treat gestational diabetes (GDM) and pregnancies complicated by pregestational type 2 diabetes or polycystic ovary syndrome but data regarding long-term offspring outcome are lacking in both human studies and animal models. Using a mouse model, this study investigated the effects of maternal metformin intervention during obese glucose-intolerant pregnancy on adiposity, hepatic steatosis and markers of metabolic health of male and female offspring up to the age of 12 months. METHODS: C57BL/6J female mice were weaned onto either a control diet (Con) or, to induce pre-conception obesity, an obesogenic diet (Ob). The respective diets were maintained throughout pregnancy and lactation. These obese dams were then randomised to the untreated group or to receive 300 mg/kg oral metformin hydrochloride treatment (Ob-Met) daily during pregnancy. In male and female offspring, body weights and body composition were measured from 1 month until 12 months of age, when serum and tissues were collected for investigation of adipocyte cellularity (histology), adipose tissue inflammation (histology and quantitative RT-PCR), and hepatic steatosis and fibrosis (histochemistry and modified Folch assay). RESULTS: At 12 months of age, male Ob and Ob-Met offspring showed increased adiposity, adipocyte hypertrophy, elevated expression of proinflammatory genes, hyperleptinaemia and hepatic lipid accumulation compared with Con offspring. Male Ob-Met offspring failed to show hyperplasia between 8 weeks and 12 months, indicative of restricted adipose tissue expansion, resulting in increased immune cell infiltration and ectopic lipid deposition. Female Ob offspring were relatively protected from these phenotypes but Ob-Met female offspring showed increased adiposity, adipose tissue inflammation, hepatic lipid accumulation, hyperleptinaemia and hyperinsulinaemia compared with Con female offspring. CONCLUSIONS/INTERPRETATION: Maternal metformin treatment of obese dams increased offspring metabolic risk factors in a sex- and age-dependent manner. These observations highlight the importance of following up offspring of both sexes beyond early adulthood after interventions during pregnancy. Our findings illustrate the complexity of balancing short-term benefits to mother and child vs any potential long-term metabolic effects on the offspring when prescribing therapeutic agents that cross the placenta.


Subject(s)
Diabetes Mellitus, Type 2 , Diabetes, Gestational , Fatty Liver , Metformin , Prenatal Exposure Delayed Effects , Humans , Pregnancy , Animals , Mice , Child , Male , Female , Adult , Infant , Metformin/pharmacology , Metformin/therapeutic use , Glucose , Diabetes Mellitus, Type 2/drug therapy , Mice, Inbred C57BL , Obesity/drug therapy , Obesity/metabolism , Body Composition , Fatty Liver/pathology , Inflammation , Lipids , Prenatal Exposure Delayed Effects/metabolism , Diet, High-Fat/adverse effects
18.
J Physiol ; 600(4): 903-919, 2022 02.
Article in English | MEDLINE | ID: mdl-34505282

ABSTRACT

Maternal obesity is a global problem that increases the risk of short- and long-term adverse outcomes for mother and child, many of which are linked to gestational diabetes mellitus. Effective treatments are essential to prevent the transmission of poor metabolic health from mother to child. Metformin is an effective glucose lowering drug commonly used to treat gestational diabetes mellitus; however, its wider effects on maternal and fetal health are poorly explored. In this study we used a mouse (C57Bl6/J) model of diet-induced (high sugar/high fat) maternal obesity to explore the impact of metformin on maternal and feto-placental health. Metformin (300 mg kg-1  day-1 ) was given to obese females via the diet and was shown to achieve clinically relevant concentrations in maternal serum (1669 ± 568 nM in late pregnancy). Obese dams developed glucose intolerance during pregnancy and had reduced uterine artery compliance. Metformin treatment of obese dams improved maternal glucose tolerance, reduced maternal fat mass and restored uterine artery function. Placental efficiency was reduced in obese dams, with increased calcification and reduced labyrinthine area. Consequently, fetuses from obese dams weighed less (P < 0.001) at the end of gestation. Despite normalisation of maternal parameters, metformin did not correct placental structure or fetal growth restriction. Metformin levels were substantial in the placenta and fetal circulation (109.7 ± 125.4 nmol g-1 in the placenta and 2063 ± 2327 nM in fetal plasma). These findings reveal the distinct effects of metformin administration during pregnancy on mother and fetus and highlight the complex balance of risk vs. benefits that are weighed in obstetric medical treatments. KEY POINTS: Maternal obesity and gestational diabetes mellitus have detrimental short- and long-term effects for mother and child. Metformin is commonly used to treat gestational diabetes mellitus in many populations worldwide but the effects on fetus and placenta are unknown. In a mouse model of diet-induced obesity and glucose intolerance in pregnancy we show reduced uterine artery compliance, placental structural changes and reduced fetal growth. Metformin treatment improved maternal metabolic health and uterine artery compliance but did not rescue obesity-induced changes in the fetus or placenta. Metformin crossed the placenta into the fetal circulation and entered fetal tissue. Metformin has beneficial effects on maternal health beyond glycaemic control. However, despite improvements in maternal physiology, metformin did not prevent fetal growth restriction or placental ageing. The high uptake of metformin into the placental and fetal circulation highlights the potential for direct immediate effects of metformin on the fetus with possible long-term consequences postnatally.


Subject(s)
Glucose Intolerance , Metformin , Obesity, Maternal , Animals , Diet, High-Fat/adverse effects , Female , Fetal Growth Retardation , Glucose Intolerance/metabolism , Humans , Infectious Disease Transmission, Vertical , Metformin/metabolism , Metformin/pharmacology , Metformin/therapeutic use , Mice , Placenta/metabolism , Pregnancy
19.
J Biol Chem ; 296: 100070, 2021.
Article in English | MEDLINE | ID: mdl-33187980

ABSTRACT

Lipids in complex, protein-enriched films at air/liquid interfaces reduce surface tension. In the absence of this benefit, the light refracting and immunoprotective tear film on eyes would collapse. Premature collapse, coupled with chronic inflammation compromising visual acuity, is a hallmark of dry eye disease affecting 7 to 10% of individuals worldwide. Although collapse seems independent of mutation (unlike newborn lung alveoli), selective proteome and possible lipidome changes have been noted. These include elevated tissue transglutaminase and consequent inactivation through C-terminal cross-linking of the tear mitogen lacritin, leading to significant loss of lacritin monomer. Lacritin monomer restores homeostasis via autophagy and mitochondrial fusion and promotes basal tearing. Here, we discover that lacritin monomer C-terminal processing, inclusive of cysteine, serine, and metalloproteinase activity, generates cationic amphipathic α-helical proteoforms. Such proteoforms (using synthetic peptide surrogates) act like alveolar surfactant proteins to rapidly bind and stabilize the tear lipid layer. Immunodepletion of C- but not N-terminal proteoforms nor intact lacritin, from normal human tears promotes loss of stability akin to human dry eye tears. Stability of these and dry eye tears is rescuable with C- but not N-terminal proteoforms. Repeated topical application in rabbits reveals a proteoform turnover time of 7 to 33 h with gradual loss from human tear lipid that retains bioactivity without further processing. Thus, the processed C-terminus of lacritin that is deficient or absent in dry eye tears appears to play a key role in preventing tear film collapse and as a natural slow release mechanism that restores epithelial homeostasis.


Subject(s)
Dry Eye Syndromes/physiopathology , Eye Proteins/metabolism , Glycoproteins/physiology , Protein Isoforms/physiology , Tears/metabolism , Animals , Disease Models, Animal , Humans , Meibomian Glands/physiology , Rabbits
20.
Clin Infect Dis ; 75(12): 2201-2210, 2022 12 19.
Article in English | MEDLINE | ID: mdl-35476134

ABSTRACT

BACKGROUND: The impact of low body mass index (BMI) at initiation of rifampicin-resistant tuberculosis (RR-TB) treatment on outcomes is uncertain. We evaluated the association between BMI at RR-TB treatment initiation and end-of-treatment outcomes. METHODS: We performed an individual participant data meta-analysis of adults aged ≥18 years with RR-TB whose BMI was documented at treatment initiation. We compared odds of any unfavorable treatment outcome, mortality, or failure/recurrence between patients who were underweight (BMI <18.5 kg/m2) and not underweight. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated using logistic regression, with matching on demographic, clinical, and treatment-related factors. We evaluated effect modification by human immunodeficiency virus (HIV) status and other variables using likelihood ratio tests. We also estimated cumulative incidence of mortality during treatment stratified by HIV. RESULTS: Overall, 5148 patients were included; 1702 (33%) were underweight at treatment initiation. The median (interquartile range) age was 37 years (29 to 47), and 455 (9%) had HIV. Compared with nonunderweight patients, the aOR among underweight patients was 1.7 (95% CI, 1.4-1.9) for any unfavorable outcome, 3.1 (2.4-3.9) for death, and 1.6 (1.2-2.0) for failure/recurrence. Significant effect modification was found for World Health Organization region of treatment. Among HIV-negative patients, 24-month mortality was 14.8% (95% CI, 12.7%-17.3%) for underweight and 5.6% (4.5%-7.0%) for not underweight patients. Among patients with HIV, corresponding values were 33.0% (25.6%-42.6%) and 20.9% (14.1%-27.6%). CONCLUSIONS: Low BMI at treatment initiation for RR-TB is associated with increased odds of unfavorable treatment outcome, particularly mortality.


Subject(s)
HIV Infections , Tuberculosis, Multidrug-Resistant , Adult , Humans , Adolescent , Antitubercular Agents/therapeutic use , Rifampin/therapeutic use , Body Mass Index , Tuberculosis, Multidrug-Resistant/drug therapy , Treatment Outcome , Weight Loss , HIV Infections/drug therapy
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