9 research outputs found
Hardware modifications to enhance the eye surface profiler
No full text<b>Purpose</b>\ud
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The <i>Eye Surface Profiler</i> (ESP) is an instrument that estimates the shape of the cornea, limbus and a portion of the sclera. Sodium fluorescein is instilled into the ocular tear film, the ESP projects blue fringe patterns from two directions and the resulting green fluorescent emission patterns are analysed. The ESP is a useful clinical and research tool and we found that its operation could be enhanced. The focusing system is relatively insensitive to changes in position and, although crucial to the operation of the instrument, tear film fluorescence cannot be viewed before data is collected. We addressed these issues to enhance its operation.\ud
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<b>Methods</b>\ud
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A video camera was attached to the ESP to view the instrument’s focusing spots from a second direction. The operator can then position the ESP at a more repeatable distance (Z) from the eye. X/Y alignment is handled via the original ESP focusing system. A blue LED ring light, operated via a footswitch, was also attached to the camera to give a live view of tear fluorescence. When consistent fluorescein coverage was observed, the operator switches off the ring light and collects data immediately with the original flash system.\ud
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To investigate repeatability, five maps were collected for the right eyes of 3 subjects using A) the original ESP focusing technique (ESPf) and B) our new camera and focusing technique (NEWf). Maps for each subject for each technique were filtered to remove artefacts then averaged to derive a standard deviation map (SD at each map grid point). To compare ESPf with NEWf, the SD maps for all subjects were averaged and split into ‘corneal’ (central 10 mm diameter) and ‘limbal/scleral’ (outside 10 mm diameter) regions.\ud
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<b>Results</b>\ud
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The ‘corneal’ average SD was 8.6 um for ESPf and 4.8 um for NEWf (44% reduction). The ‘limbal/scleral’ average SD was 19.6 um for ESPf and 11.1 um for NEWf (43% reduction).\ud
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<b>Conclusions</b>\ud
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The hardware modifications to the ESP have enhanced focusing precision and reduced variability between maps for the eyes tested. By viewing tear film fluorescence prior to collecting data, we have also ensured that tear film artefacts have less impact on data quality
Independent glial subtypes delay development and extend healthy lifespan upon reduced insulin-PI3K signalling
No full textBackground: The increasing age of global populations highlights the urgent need to understand the biological
underpinnings of ageing. To this end, inhibition of the insulin/insulin-like signalling (IIS) pathway can extend
healthy lifespan in diverse animal species, but with trade-offs including delayed development. It is possible that
distinct cell types underlie effects on development and ageing; cell-type-specific strategies could therefore
potentially avoid negative trade-offs when targeting diseases of ageing, including prevalent neurodegenerative
diseases. The highly conserved diversity of neuronal and non-neuronal (glial) cell types in the Drosophila nervous
system makes it an attractive system to address this possibility. We have thus investigated whether IIS in distinct
glial cell populations differentially modulates development and lifespan in Drosophila.
Results: We report here that glia-specific IIS inhibition, using several genetic means, delays development while
extending healthy lifespan. The effects on lifespan can be recapitulated by adult-onset IIS inhibition, whereas
developmental IIS inhibition is dispensable for modulation of lifespan. Notably, the effects we observe on both
lifespan and development act through the PI3K branch of the IIS pathway and are dependent on the transcription
factor FOXO. Finally, IIS inhibition in several glial subtypes can delay development without extending lifespan,
whereas the same manipulations in astrocyte-like glia alone are sufficient to extend lifespan without altering
developmental timing.
Conclusions: These findings reveal a role for distinct glial subpopulations in the organism-wide modulation of
development and lifespan, with IIS in astrocyte-like glia contributing to lifespan modulation but not to
developmental timing. Our results enable a more complete picture of the cell-type-specific effects of the IIS
network, a pathway whose evolutionary conservation in humans make it tractable for therapeutic interventions. Our
findings therefore underscore the necessity for cell-type-specific strategies to optimise interventions for the diseases
of agein
The neuronal receptor tyrosine kinase Alk is a target for longevity
No full textInhibition of signalling through several receptor tyrosine kinases (RTKs), including the insulin-like growth factor receptor and its orthologues, extends healthy lifespan in organisms from diverse evolutionary taxa. This raises the possibility that other RTKs, including those already well studied for their roles in cancer and developmental biology, could be promising targets for extending healthy lifespan. Here, we focus on anaplastic lymphoma kinase (Alk), an RTK with established roles in nervous system development and in multiple cancers, but whose effects on aging remain unclear. We find that several means of reducing Alk signalling, including mutation of its ligand jelly belly (jeb), RNAi knock-down of Alk, or expression of dominant-negative Alk in adult neurons, can extend healthy lifespan in female, but not male, Drosophila. Moreover, reduced Alk signalling preserves neuromuscular function with age, promotes resistance to starvation and xenobiotic stress, and improves night sleep consolidation. We find further that inhibition of Alk signalling in adult neurons modulates the expression of several insulin-like peptides, providing a potential mechanistic link between neuronal Alk signalling and organism-wide insulin-like signalling. Finally, we show that TAE-684, a small molecule inhibitor of Alk, can extend healthy lifespan in Drosophila, suggesting that the repurposing of Alk inhibitors may be a promising direction for strategies to promote healthy aging.sponsorship: Biotechnology and Biological Sciences Research Council, Grant/Award Number: BB/M029093/1 (Alic); Alzheimer's Society, Grant/Award Number: Junior Fellowship (Woodling); Wellcome Trust, Grant/Award Number: Strategic Award (Partridge); Alzheimer's Research Trust, Grant/Award Number: ARUK UCL Network Pump-Priming Award (Woodling) (Biotechnology and Biological Sciences Research Council|BB/M029093/1, Alzheimer's Society, Wellcome Trust, Alzheimer's Research Trust)status: Publishe
Short-Term, Intermittent Fasting Induces Long-Lasting Gut Health and TOR-Independent Lifespan Extension
No full textIntermittent fasting (IF) can improve function and health during aging in laboratory model organisms, but the mechanisms at work await elucidation. We subjected fruit flies (Drosophila melanogaster) to varying degrees of IF and found that just one month of a 2-day fed:5-day fasted IF regime at the beginning of adulthood was sufficient to extend lifespan. This long-lasting, beneficial effect of early IF was not due to reduced fecundity. Starvation resistance and resistance to oxidative and xenobiotic stress were increased after IF. Early-life IF also led to higher lipid content in 60-day-old flies, a potential explanation for increased longevity. Guts of flies 40 days post-IF showed a significant reduction in age-related pathologies and improved gut barrier function. Improved gut health was also associated with reduced relative bacterial abundance. Early IF thus induced profound long-term changes. Pharmacological and genetic epistasis analysis showed that IF acted independently of the TOR pathway because rapamycin and IF acted additively to extend lifespan, and global expression of a constitutively active S6K did not attenuate the IF-induced lifespan extension. We conclude that short-term IF during early life can induce long-lasting beneficial effects, with robust increase in lifespan in a TOR-independent manner, probably at least in part by preserving gut health.sponsorship: We thank Dr. Elizabeth Skinner for helpful comments and Dr. Nathan Woodling for help with statistics. We are grateful to members of the Partridge and Gems laboratories for helpful discussions. This work was funded by a Wellcome Trust Strategic Award (098565). (Wellcome Trust|098565, Wellcome Trust|098565/Z/12/Z)status: Publishe
Cell type-specific modulation of healthspan by Forkhead family transcription factors in the nervous system
No full textReduced activity of insulin/insulin-like growth factor signaling (IIS) increases healthy lifespan among diverse animal species. Downstream of IIS, multiple evolutionarily conserved transcription factors (TFs) are required; however, distinct TFs are likely responsible for these effects in different tissues. Here we have asked which TFs can extend healthy lifespan within distinct cell types of the adult nervous system in Drosophila. Starting from published single-cell transcriptomic data, we report that forkhead (FKH) is endogenously expressed in neurons, whereas forkhead-box-O (FOXO) is expressed in glial cells. Accordingly, we find that neuronal FKH and glial FOXO exert independent prolongevity effects. We have further explored the role of neuronal FKH in a model of Alzheimer’s disease-associated neuronal dysfunction, where we find that increased neuronal FKH preserves behavioral function and reduces ubiquitinated protein aggregation. Finally, using transcriptomic profiling, we identify Atg17, a member of the Atg1 autophagy initiation family, as one FKH-dependent target whose neuronal overexpression is sufficient to extend healthy lifespan. Taken together, our results underscore the importance of cell type-specific mapping of TF activity to preserve healthy function with age
Protein retention in the endoplasmic reticulum rescues Aβ toxicity in Drosophila
No full textAmyloid β (Aβ) accumulation is a hallmark of Alzheimer's disease. In adult Drosophila brains, human Aβ overexpression harms climbing and lifespan. It's uncertain whether Aβ is intrinsically toxic or activates downstream neurodegeneration pathways. Our study uncovers a novel protective role against Aβ toxicity: intra-endoplasmic reticulum (ER) protein accumulation with a focus on laminin and collagen subunits. Despite high Aβ, laminin B1 (LanB1) overexpression robustly counters toxicity, suggesting a potential Aβ resistance mechanism. Other laminin subunits and collagen IV also alleviate Aβ toxicity; combining them with LanB1 augments the effect. Imaging reveals ER retention of LanB1 without altering Aβ secretion. LanB1's rescue function operates independently of the IRE1α/XBP1 ER stress response. ER-targeted GFP overexpression also mitigates Aβ toxicity, highlighting broader ER protein retention advantages. Proof-of-principle tests in murine hippocampal slices using mouse Lamb1 demonstrate ER retention in transduced cells, indicating a conserved mechanism. Though ER protein retention generally harms, it could paradoxically counter neuronal Aβ toxicity, offering a new therapeutic avenue for Alzheimer's disease
Protein retention in the endoplasmic reticulum rescues Aβ toxicity in Drosophila
No full textAmyloid β (Aβ) accumulation is a hallmark of Alzheimer’s disease. In adult Drosophila brains, human Aβ overexpression harms climbing and lifespan. It’s uncertain whether Aβ is intrinsically toxic or activates downstream neurodegeneration pathways. Our study uncovers a novel protective role against Aβ toxicity: intra-endoplasmic reticulum (ER) protein accumulation with a focus on laminin and collagen subunits. Despite high Aβ, laminin B1 (LanB1) overexpression robustly counters toxicity, suggesting a potential Aβ resistance mechanism. Other laminin subunits and collagen IV also alleviate Aβ toxicity; combining them with LanB1 augments the effect. Imaging reveals ER retention of LanB1 without altering Aβ secretion. LanB1’s rescue function operates independently of the IRE1α/XBP1 ER stress response. ER-targeted GFP overexpression also mitigates Aβ toxicity, highlighting broader ER protein retention advantages. Proof-of-principle tests in murine hippocampal slices using mouse Lamb1 demonstrate ER retention in transduced cells, indicating a conserved mechanism. Though ER protein retention generally harms, it could paradoxically counter neuronal Aβ toxicity, offering a new therapeutic avenue for Alzheimer’s disease
A 12-gene pharmacogenetic panel to prevent adverse drug reactions: an open-label, multicentre, controlled, cluster-randomised crossover implementation study.
No full textBackgroundThe benefit of pharmacogenetic testing before starting drug therapy has been well documented for several single gene-drug combinations. However, the clinical utility of a pre-emptive genotyping strategy using a pharmacogenetic panel has not been rigorously assessed.MethodsWe conducted an open-label, multicentre, controlled, cluster-randomised, crossover implementation study of a 12-gene pharmacogenetic panel in 18 hospitals, nine community health centres, and 28 community pharmacies in seven European countries (Austria, Greece, Italy, the Netherlands, Slovenia, Spain, and the UK). Patients aged 18 years or older receiving a first prescription for a drug clinically recommended in the guidelines of the Dutch Pharmacogenetics Working Group (ie, the index drug) as part of routine care were eligible for inclusion. Exclusion criteria included previous genetic testing for a gene relevant to the index drug, a planned duration of treatment of less than 7 consecutive days, and severe renal or liver insufficiency. All patients gave written informed consent before taking part in the study. Participants were genotyped for 50 germline variants in 12 genes, and those with an actionable variant (ie, a drug-gene interaction test result for which the Dutch Pharmacogenetics Working Group [DPWG] recommended a change to standard-of-care drug treatment) were treated according to DPWG recommendations. Patients in the control group received standard treatment. To prepare clinicians for pre-emptive pharmacogenetic testing, local teams were educated during a site-initiation visit and online educational material was made available. The primary outcome was the occurrence of clinically relevant adverse drug reactions within the 12-week follow-up period. Analyses were irrespective of patient adherence to the DPWG guidelines. The primary analysis was done using a gatekeeping analysis, in which outcomes in people with an actionable drug-gene interaction in the study group versus the control group were compared, and only if the difference was statistically significant was an analysis done that included all of the patients in the study. Outcomes were compared between the study and control groups, both for patients with an actionable drug-gene interaction test result (ie, a result for which the DPWG recommended a change to standard-of-care drug treatment) and for all patients who received at least one dose of index drug. The safety analysis included all participants who received at least one dose of a study drug. This study is registered with ClinicalTrials.gov, NCT03093818 and is closed to new participants.FindingsBetween March 7, 2017, and June 30, 2020, 41 696 patients were assessed for eligibility and 6944 (51·4 % female, 48·6% male; 97·7% self-reported European, Mediterranean, or Middle Eastern ethnicity) were enrolled and assigned to receive genotype-guided drug treatment (n=3342) or standard care (n=3602). 99 patients (52 [1·6%] of the study group and 47 [1·3%] of the control group) withdrew consent after group assignment. 652 participants (367 [11·0%] in the study group and 285 [7·9%] in the control group) were lost to follow-up. In patients with an actionable test result for the index drug (n=1558), a clinically relevant adverse drug reaction occurred in 152 (21·0%) of 725 patients in the study group and 231 (27·7%) of 833 patients in the control group (odds ratio [OR] 0·70 [95% CI 0·54-0·91]; p=0·0075), whereas for all patients, the incidence was 628 (21·5%) of 2923 patients in the study group and 934 (28·6%) of 3270 patients in the control group (OR 0·70 [95% CI 0·61-0·79]; p InterpretationGenotype-guided treatment using a 12-gene pharmacogenetic panel significantly reduced the incidence of clinically relevant adverse drug reactions and was feasible across diverse European health-care system organisations and settings. Large-scale implementation could help to make drug therapy increasingly safe.FundingEuropean Union Horizon 2020
A 12-gene pharmacogenetic panel to prevent adverse drug reactions: an open-label, multicentre, controlled, cluster-randomised crossover implementation study
No full text© 2023Background: The benefit of pharmacogenetic testing before starting drug therapy has been well documented for several single gene–drug combinations. However, the clinical utility of a pre-emptive genotyping strategy using a pharmacogenetic panel has not been rigorously assessed. Methods: We conducted an open-label, multicentre, controlled, cluster-randomised, crossover implementation study of a 12-gene pharmacogenetic panel in 18 hospitals, nine community health centres, and 28 community pharmacies in seven European countries (Austria, Greece, Italy, the Netherlands, Slovenia, Spain, and the UK). Patients aged 18 years or older receiving a first prescription for a drug clinically recommended in the guidelines of the Dutch Pharmacogenetics Working Group (ie, the index drug) as part of routine care were eligible for inclusion. Exclusion criteria included previous genetic testing for a gene relevant to the index drug, a planned duration of treatment of less than 7 consecutive days, and severe renal or liver insufficiency. All patients gave written informed consent before taking part in the study. Participants were genotyped for 50 germline variants in 12 genes, and those with an actionable variant (ie, a drug–gene interaction test result for which the Dutch Pharmacogenetics Working Group [DPWG] recommended a change to standard-of-care drug treatment) were treated according to DPWG recommendations. Patients in the control group received standard treatment. To prepare clinicians for pre-emptive pharmacogenetic testing, local teams were educated during a site-initiation visit and online educational material was made available. The primary outcome was the occurrence of clinically relevant adverse drug reactions within the 12-week follow-up period. Analyses were irrespective of patient adherence to the DPWG guidelines. The primary analysis was done using a gatekeeping analysis, in which outcomes in people with an actionable drug–gene interaction in the study group versus the control group were compared, and only if the difference was statistically significant was an analysis done that included all of the patients in the study. Outcomes were compared between the study and control groups, both for patients with an actionable drug–gene interaction test result (ie, a result for which the DPWG recommended a change to standard-of-care drug treatment) and for all patients who received at least one dose of index drug. The safety analysis included all participants who received at least one dose of a study drug. This study is registered with ClinicalTrials.gov, NCT03093818 and is closed to new participants. Findings: Between March 7, 2017, and June 30, 2020, 41 696 patients were assessed for eligibility and 6944 (51·4 % female, 48·6% male; 97·7% self-reported European, Mediterranean, or Middle Eastern ethnicity) were enrolled and assigned to receive genotype-guided drug treatment (n=3342) or standard care (n=3602). 99 patients (52 [1·6%] of the study group and 47 [1·3%] of the control group) withdrew consent after group assignment. 652 participants (367 [11·0%] in the study group and 285 [7·9%] in the control group) were lost to follow-up. In patients with an actionable test result for the index drug (n=1558), a clinically relevant adverse drug reaction occurred in 152 (21·0%) of 725 patients in the study group and 231 (27·7%) of 833 patients in the control group (odds ratio [OR] 0·70 [95% CI 0·54–0·91]; p=0·0075), whereas for all patients, the incidence was 628 (21·5%) of 2923 patients in the study group and 934 (28·6%) of 3270 patients in the control group (OR 0·70 [95% CI 0·61–0·79]; p <0·0001). Interpretation: Genotype-guided treatment using a 12-gene pharmacogenetic panel significantly reduced the incidence of clinically relevant adverse drug reactions and was feasible across diverse European health-care system organisations and settings. Large-scale implementation could help to make drug therapy increasingly safe. Funding: European Union Horizon 2020
