Research Discoveries in January 2024

Journal: Proceedings. Biological Sciences

The detection of optic flow is important for generating optomotor responses to mediate retinal image stabilization, and it can also be used during ongoing locomotion for centring and velocity control. Previous work in hummingbirds has separately examined the roles of optic flow during hovering and when centring through a narrow passage during forward flight. To develop a hypothesis for the visual control of forward flight velocity, we examined the behaviour of hummingbirds in a flight tunnel where optic flow could be systematically manipulated. In all treatments, the animals exhibited periods of forward flight interspersed with bouts of spontaneous hovering. Hummingbirds flew fastest when they had a reliable signal of optic flow. All optic flow manipulations caused slower flight, suggesting that hummingbirds had an expected optic flow magnitude that was disrupted. In addition, upward and downward optic flow drove optomotor responses for maintaining altitude during forward flight. When hummingbirds made voluntary transitions to hovering, optomotor responses were observed to all directions. Collectively, these results are consistent with hummingbirds controlling flight speed via mechanisms that use an internal forward model to predict expected optic flow whereas flight altitude and hovering position are controlled more directly by sensory feedback from the environment.

Baliga VB, Dakin R, Wylie DR, Altshuler DL. Hummingbirds use distinct control strategies for forward and hovering flight. Proc Biol Sci. 2024 Jan 10;291(2014):20232155. doi: 10.1098/rspb.2023.2155. Epub 2024 Jan 10. 

Journal: medRxiv

Background: Parkinson's disease (PD) is a progressive neurodegenerative disorder. Mendelian forms have revealed multiple genes, with a notable emphasis on membrane trafficking; RAB GTPases play an important role in PD as a subset are both regulators and substrates of LRRK2 protein kinase. To explore the role of RAB GTPases in PD, we undertook a comprehensive examination of their genetic variability in familial PD.

Methods: Affected probands from 130 multi-incident PD families underwent whole-exome sequencing and genotyping, Potential pathogenic variants in 61 RAB GTPases were genotyped in relatives to assess disease segregation. These variants were also genotyped in a larger case-control series, totaling 3,078 individuals (2,734 with PD). The single most significant finding was subsequently validated within genetic data (6,043 with PD). Clinical and pathologic findings were summarized for gene-identified patients, and haplotypes were constructed. In parallel, wild-type and mutant RAB GTPase structural variation, protein interactions, and resultant enzyme activities were assessed.

Findings: We found RAB32 c.213C>G (Ser71Arg) to co-segregate with autosomal dominant parkinsonism in three multi-incident families. RAB32 Ser71Arg was also significantly associated with PD in case-control samples: genotyping and database searches identified thirteen more patients with the same variant that was absent in unaffected controls. Notably, RAB32 Ser71Arg heterozygotes share a common haplotype. At autopsy, one patient had sparse neurofibrillary tangle pathology in the midbrain and thalamus, without Lewy body pathology. In transfected cells the RAB32 Arg71 was twice as potent as Ser71 wild type to activate LRRK2 kinase.

Interpretation: Our study provides unequivocal evidence to implicate RAB32 Ser71Arg in PD. Functional analysis demonstrates LRRK2 kinase activation. We provide a mechanistic explanation to expand and unify the etiopathogenesis of monogenic PD.

Funding: National Institutes of Health, the Canada Excellence Research Chairs program, Aligning Science Across Parkinson's, the Michael J. Fox Foundation for Parkinson's Research, and the UK

Gustavsson EK, Follett J, Trinh J, Barodia SK, Real R, Liu Z, Grant-Peters M, Fox JD, Appel-Cresswell S, Stoessl AJ, Rajput A, Rajput AH, Auer R, Tilney R, Sturm M, Haack TB, Lesage S, Tesson C, Brice A, Vilariño-Güell C, Ryten M, Goldberg MS, West AB, Hu MT, Morris HR, Sharma M, Gan-Or Z, Samanci B, Lis P, Tocino T, Amouri R, Sassi SB, Hentati F; Global Parkinson’s Genetics Program (GP2); Tonelli F, Alessi DR, Farrer MJ. A pathogenic variant in RAB32 causes autosomal dominant Parkinson's disease and activates LRRK2 kinase. medRxiv [Preprint]. 2024 Jan 18:2024.01.17.24300927. doi: 10.1101/2024.01.17.24300927. PMID: 38293014; PMCID: PMC10827257.

Journal: Journal of Parkinson's Disease

The aim of this review is to examine the intersection of Parkinson's disease (PD) with nutrition, to identify best nutritional practices based on current evidence, and to identify gaps in the evidence and suggest future directions. Epidemiological work has linked various dietary patterns and food groups to changes in PD risk; however, fewer studies have evaluated the role of various diets, dietary components, and supplements in the management of established PD. There is substantial interest in exploring the role of diet-related interventions in both symptomatic management and potential disease modification. In this paper, we evaluate the utility of several dietary patterns, including the Mediterranean (MeDi), Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), Alternative Healthy Eating Index (AHEI), vegan/vegetarian, and ketogenic diet in persons with PD. Additionally, we provide an overview of the evidence relating several individual food groups and nutritional supplements to PD risk, symptoms and progression.

Tosefsky KN, Zhu J, Wang YN, Lam JST, Cammalleri A, Appel-Cresswell S. The Role of Diet in Parkinson's Disease. J Parkinsons Dis. 2024 Jan 13. doi: 10.3233/JPD-230264. Epub ahead of print. PMID: 38251061.

Journal: ACS Sustainable Chemistry & Engineering

Driven by long-term persistence and adverse health impacts of legacy perfluorooctanoic acid (PFOA), production has shifted towards shorter chain analogs (C4, perfluorobutanoic acid (PFBA)) or fluorinated alternatives such as hexafluoropropylene oxide dimer acid (HFPO-DA, known as GenX) and 6:2 fluorotelomer carboxylic acid (6:2 FTCA). Yet, a thorough understanding of treatment processes for these alternatives is limited. Herein, we conducted a comprehensive study using an electrochemical approach with a boron doped diamond anode in Na₂SO₄ electrolyte for the remediation of PFOA common alternatives, i.e., PFBA, GenX, and 6:2 FTCA. The degradability, fluorine recovery, transformation pathway, and contributions from electro-synthesized radicals were investigated. The results indicated the significance of chain length and structure, with shorter chains being harder to break down (PFBA (65.6 ± 5.0%) < GenX (84.9 ± 3.3%) < PFOA (97.9 ± 0.1%) < 6:2 FTCA (99.4 ± 0.0%) within 120 min of electrolysis). The same by-products were observed during the oxidation of both low and high concentrations of parent PFAS (2 and 20 mg L^-1), indicating that the fundamental mechanism of PFAS degradation remained consistent. Nevertheless, the ratio of these by-products to the parent PFAS concentration varied which primarily arises from the more rapid PFAS decomposition at lower dosages. For all experiments, the main mechanism of PFAS oxidation was initiated by direct electron transfer at the anode surface. Sulfate radical (SO₄^•-) also contributed to the oxidation of all PFAS, while hydroxyl radical (^•OH) only played a role in the decomposition of 6:2 FTCA. Total fluorine recovery of PFBA, GenX, and 6:2 FTCA were 96.5%, 94.0%, and 76.4% within 240 min. The more complex transformation pathway of 6:2 FTCA could explain its lower fluorine recovery. Detailed decomposition pathways for each PFAS were also proposed through identifying the generated intermediates and fluorine recovery. The proposed pathways were also assessed using ¹⁹F Nuclear Magnetic Resonance (NMR) spectroscopy.

Asadi Zeidabadi F, Banayan Esfahani E, Moreira R, McBeath ST, Foster J, Mohseni M. Structural dependence of PFAS oxidation in a boron doped diamond-electrochemical system. Environ Res. 2024 Jan 3;246:118103. doi: 10.1016/j.envres.2024.118103. Epub ahead of print. PMID: 38181849.

Journal: mSystems

In eusocial insects, the health of the queens-the colony founders and sole reproductive females-is a primary determinant for colony success. Queen failure in the honey bee Apis mellifera, for example, is a major concern of beekeepers who annually suffer colony losses, necessitating a greater knowledge of queen health. Several studies on the microbiome of honey bees have characterized its diversity and shown its importance for the health of worker bees, the female non-reproductive caste. However, the microbiome of workers differs from that of queens, which, in comparison, is still poorly studied. Thus, direct investigations of the queen microbiome are required to understand colony-level microbiome assembly, functional roles, and evolution. Here, we used metagenomics to comprehensively characterize the honey bee queen microbiome. Comparing samples from different geographic locations and breeder sources, we show that the microbiome of queens is mostly shaped by the environment experienced since early life and is predicted to play roles in the breakdown of the diet and protection from pathogens and xenobiotics. We also reveal that the microbiome of queens comprises only four candidate core bacterial species, Apilactobacillus kunkeei, Lactobacillus apis, Bombella apis, and Commensalibacter sp. Interestingly, in addition to bacteria, we show that bacteriophages infect the queen microbiome, for which Lactobacillaceae are predicted to be the main reservoirs. Together, our results provide the basis to understand the honey bee colony microbiome assemblage, can guide improvements in queen-rearing processes, and highlight the importance of considering bacteriophages for queen microbiome health and microbiome homeostasis in eusocial insects.IMPORTANCEThe queen caste plays a central role in colony success in eusocial insects, as queens lay eggs and regulate colony behavior and development. Queen failure can cause colonies to collapse, which is one of the major concerns of beekeepers. Thus, understanding the biology behind the queen's health is a pressing issue. Previous studies have shown that the bee microbiome plays an important role in worker bee health, but little is known about the queen microbiome and its function in vivo. Here, we characterized the queen microbiome, identifying for the first time the present species and their putative functions. We show that the queen microbiome has predicted nutritional and protective roles in queen association and comprises only four consistently present bacterial species. Additionally, we bring to attention the spread of phages in the queen microbiome, which increased in abundance in failing queens and may impact the fate of the colony.

Caesar L, Rice DW, McAfee A, Underwood R, Ganote C, Tarpy DR, Foster LJ, Newton ILG. Metagenomic analysis of the honey bee queen microbiome reveals low bacterial diversity and Caudoviricetes phages. mSystems. 2024 Jan 23:e0118223. doi: 10.1128/msystems.01182-23. Epub ahead of print. PMID: 38259099.

Journal: Proceedings. Biological Sciences

Evidence for a trade-off between reproduction and immunity has manifested in many animal species, including social insects. However, investigations in social insect queens present a conundrum: new gynes of many social hymenopterans, such as bumble bees and ants, must first mate, then transition from being solitary to social as they establish their nests, thus experiencing confounding shifts in environmental conditions. Worker bumble bees offer an opportunity to investigate patterns of immune protein expression associated with ovary activation while minimizing extraneous environmental factors and genetic differences. Here, we use proteomics to interrogate the patterns of immune protein expression of female bumble bees (Bombus impatiens) by (i) sampling queens at different stages of their life cycle, then (ii) by sampling workers with different degrees of ovary activation. Patterns of immune protein expression in the haemolymph of queens are consistent with a reproduction-immunity trade-off, but equivalent samples from workers are not. This brings into question whether queen bumble bees really experience a reproduction-immunity trade-off, or if patterns of immune protein expression may actually be due to the selective pressure of the different environmental conditions they are exposed to during their life cycle.

McAfee A, Chapman A, Bao G, Tarpy DR, Foster LJ. Investigating trade-offs between ovary activation and immune protein expression in bumble bee (Bombus impatiens) workers and queens. Proc Biol Sci. 2024 Jan 31;291(2015):20232463. doi: 10.1098/rspb.2023.2463. Epub 2024 Jan 24. PMID: 38264776; PMCID: PMC10806398.

Journal: JMIR Formative Research

Background: Hypertension affects 1 in 5 Canadians and is the leading cause of morbidity and mortality globally. Hypertension control is declining due to multiple factors including lack of access to primary care. Consequently, patients with hypertension frequently visit the emergency department (ED) due to high blood pressure (BP). Telehealth for Emergency-Community Continuity of Care Connectivity via Home-Telemonitoring Blood Pressure is a pilot project that implements and evaluates a comprehensive home blood pressure telemonitoring (HBPT) and physician case management protocol designed as a postdischarge management strategy to support patients with asymptomatic elevated BP as they transition from the ED to home.

Objective: Our objective was to conduct a feasibility study of an HBPT program for patients with asymptomatic elevated BP discharged from the ED.

Methods: Patients discharged from an urban, tertiary care hospital ED with asymptomatic elevated BP were recruited in Vancouver, British Columbia, Canada, and provided with HBPT technology for 3 months of monitoring post discharge and referred to specialist hypertension clinics. Participants monitored their BP twice in the morning and evenings and tele-transmitted readings via Bluetooth Sensor each day using an app. A monitoring clinician received these data and monitored the patient's condition daily and adjusted antihypertensive medications. Feasibility outcomes included eligibility, recruitment, adherence to monitoring, and retention rates. Secondary outcomes included proportion of those who were defined as having hypertension post-ED visits, changes in mean BP, overall BP control, medication adherence, changes to antihypertensive medications, quality of life, and end user experience at 3 months.

Results: A total of 46 multiethnic patients (mean age 63, SD 17 years, 69%, n=32 women) found to have severe hypertension (mean 191, SD 23/mean 100, SD 14 mm Hg) in the ED were recruited, initiated on HBPT with hypertension specialist physician referral and followed up for 3 months. Eligibility and recruitment rates were 40% (56/139) and 88% (49/56), respectively. The proportion of participants that completed ≥80% of home BP measurements at 1 and 3 months were 67% (31/46) and 41% (19/46), respectively. The proportion of individuals who achieved home systolic BP and diastolic BP control at 3 months was 71.4% (30/42) and 85.7% (36/42) respectively. Mean home systolic and diastolic BP improved by -13/-5 mm Hg after initiation of HBPT to the end of the study. Patients were prescribed 1 additional antihypertensive medication. No differences in medication adherence from enrollment to 3 months were noted. Most patients (76%, 25/33) were highly satisfied with the HBPT program and 76% (25/33) found digital health tools easy to use.

Conclusions: HBPT intervention is a feasible postdischarge management strategy and can be beneficial in supporting patients with asymptomatic elevated BP from the ED. A randomized trial is underway to evaluate the efficacy of this intervention on BP control.

Tran KC, Mak M, Kuyper LM, Bittman J, Mangat B, Lindsay H, Kim Sing C, Xu L, Wong H, Dawes M, Khan N, Ho K. Home Blood Pressure Telemonitoring Technology for Patients With Asymptomatic Elevated Blood Pressure Discharged From the Emergency Department: Pilot Study. JMIR Form Res. 2024 Jan 30;8:e49592. doi: 10.2196/49592. PMID: 38111177.

Journal: Nucleic Acids Research

The Human Phenotype Ontology (HPO) is a widely used resource that comprehensively organizes and defines the phenotypic features of human disease, enabling computational inference and supporting genomic and phenotypic analyses through semantic similarity and machine learning algorithms. The HPO has widespread applications in clinical diagnostics and translational research, including genomic diagnostics, gene-disease discovery, and cohort analytics. In recent years, groups around the world have developed translations of the HPO from English to other languages, and the HPO browser has been internationalized, allowing users to view HPO term labels and in many cases synonyms and definitions in ten languages in addition to English. Since our last report, a total of 2239 new HPO terms and 49235 new HPO annotations were developed, many in collaboration with external groups in the fields of psychiatry, arthrogryposis, immunology and cardiology. The Medical Action Ontology (MAxO) is a new effort to model treatments and other measures taken for clinical management. Finally, the HPO consortium is contributing to efforts to integrate the HPO and the GA4GH Phenopacket Schema into electronic health records (EHRs) with the goal of more standardized and computable integration of rare disease data in EHRs.

Gargano MA, Matentzoglu N, Coleman B, Addo-Lartey EB, Anagnostopoulos AV, Anderton J, Avillach P, Bagley AM, Bakštein E, Balhoff JP, Baynam G, Bello SM, Berk M, Bertram H, Bishop S, Blau H, Bodenstein DF, Botas P, Boztug K, Čady J, Callahan TJ, Cameron R, Carbon SJ, Castellanos F, Caufield JH, Chan LE, Chute CG, Cruz-Rojo J, Dahan-Oliel N, Davids JR, de Dieuleveult M, de Souza V, de Vries BBA, de Vries E, DePaulo JR, Derfalvi B, Dhombres F, Diaz-Byrd C, Dingemans AJM, Donadille B, Duyzend M, Elfeky R, Essaid S, Fabrizzi C, Fico G, Firth HV, Freudenberg-Hua Y, Fullerton JM, Gabriel DL, Gilmour K, Giordano J, Goes FS, Moses RG, Green I, Griese M, Groza T, Gu W, Guthrie J, Gyori B, Hamosh A, Hanauer M, Hanušová K, He YO, Hegde H, Helbig I, Holasová K, Hoyt CT, Huang S, Hurwitz E, Jacobsen JOB, Jiang X, Joseph L, Keramatian K, King B, Knoflach K, Koolen DA, Kraus ML, Kroll C, Kusters M, Ladewig MS, Lagorce D, Lai MC, Lapunzina P, Laraway B, Lewis-Smith D, Li X, Lucano C, Majd M, Marazita ML, Martinez-Glez V, McHenry TH, McInnis MG, McMurry JA, Mihulová M, Millett CE, Mitchell PB, Moslerová V, Narutomi K, Nematollahi S, Nevado J, Nierenberg AA, Čajbiková NN, Nurnberger JI Jr, Ogishima S, Olson D, Ortiz A, Pachajoa H, Perez de Nanclares G, Peters A, Putman T, Rapp CK, Rath A, Reese J, Rekerle L, Roberts AM, Roy S, Sanders SJ, Schuetz C, Schulte EC, Schulze TG, Schwarz M, Scott K, Seelow D, Seitz B, Shen Y, Similuk MN, Simon ES, Singh B, Smedley D, Smith CL, Smolinsky JT, Sperry S, Stafford E, Stefancsik R, Steinhaus R, Strawbridge R, Sundaramurthi JC, Talapova P, Tenorio Castano JA, Tesner P, Thomas RH, Thurm A, Turnovec M, van Gijn ME, Vasilevsky NA, Vlčková M, Walden A, Wang K, Wapner R, Ware JS, Wiafe AA, Wiafe SA, Wiggins LD, Williams AE, Wu C, Wyrwoll MJ, Xiong H, Yalin N, Yamamoto Y, Yatham LN, Yocum AK, Young AH, Yüksel Z, Zandi PP, Zankl A, Zarante I, Zvolský M, Toro S, Carmody LC, Harris NL, Munoz-Torres MC, Danis D, Mungall CJ, Köhler S, Haendel MA, Robinson PN. The Human Phenotype Ontology in 2024: phenotypes around the world. Nucleic Acids Res. 2024 Jan 5;52(D1):D1333-D1346. doi: 10.1093/nar/gkad1005. PMID: 37953324; PMCID: PMC10767975.

Journal: The Lancet. Neurology

Background: Laquinimod modulates CNS inflammatory pathways thought to be involved in the pathology of Huntington's disease. Studies with laquinimod in transgenic rodent models of Huntington's disease suggested improvements in motor function, reduction of brain volume loss, and prolonged survival. We aimed to evaluate the safety and efficacy of laquinimod in improving motor function and reducing caudate volume loss in patients with Huntington's disease.

Methods: LEGATO-HD was a multicentre, double-blind, placebo-controlled, phase 2 study done at 48 sites across ten countries (Canada, Czech Republic, Germany, Italy, Netherlands, Portugal, Russia, Spain, UK, and USA). Patients aged 21-55 years with a cytosine-adenosine-guanine (CAG) repeat length of between 36 and 49 who had symptomatic Huntington's disease with a Unified Huntington's Disease Rating Scale-Total Motor Score (UHDRS-TMS) of higher than 5 and a Total Functional Capacity score of 8 or higher were randomly assigned (1:1:1:1) by centralised interactive response technology to laquinimod 0·5 mg, 1·0 mg, or 1·5 mg, or to matching placebo, administered orally once daily over 52 weeks; people involved in the randomisation had no other role in the study. Participants, investigators, and study personnel were masked to treatment assignment. The 1·5 mg group was discontinued before recruitment was finished because of cardiovascular safety concerns in multiple sclerosis studies. The primary endpoint was change from baseline in the UHDRS-TMS and the secondary endpoint was percent change in caudate volume, both comparing the 1·0 mg group with the placebo group at week 52. Primary and secondary endpoints were assessed in the full analysis set (ie, all randomised patients who received at least one dose of study drug and had at least one post-baseline UHDRS-TMS assessment). Safety measures included adverse event frequency and severity, and clinical and laboratory examinations, and were assessed in the safety analysis set (ie, all randomised patients who received at least one dose of study drug). This trial is registered with ClinicalTrials.gov, NCT02215616, and EudraCT, 2014-000418-75, and is now complete.

Findings: Between Oct 28, 2014, and June 19, 2018, 352 adults with Huntington's disease (179 [51%] men and 173 [49%] women; mean age 43·9 [SD 7·6] years and 340 [97%] White) were randomly assigned: 107 to laquinimod 0·5 mg, 107 to laquinimod 1·0 mg, 30 to laquinimod 1·5 mg, and 108 to matching placebo. Least squares mean change from baseline in UHDRS-TMS at week 52 was 1·98 (SE 0·83) in the laquinimod 1·0 mg group and 1·2 (0·82) in the placebo group (least squares mean difference 0·78 [95% CI -1·42 to 2·98], p=0·4853). Least squares mean change in caudate volume was 3·10% (SE 0·38) in the 1·0 mg group and 4·86% (0·38) in the placebo group (least squares mean difference -1·76% [95% CI -2·67 to -0·85]; p=0·0002). Laquinimod was well tolerated and there were no new safety findings. Serious adverse events were reported by eight (7%) patients on placebo, seven (7%) on laquinimod 0·5 mg, five (5%) on laquinimod 1·0 mg, and one (3%) on laquinimod 1·5 mg. There was one death, which occurred in the placebo group and was unrelated to treatment. The most frequent adverse events in all laquinimod dosed groups (0·5 mg, 1·0 mg, and 1·5 mg) were headache (38 [16%]), diarrhoea (24 [10%]), fall (18 [7%]), nasopharyngitis (20 [8%]), influenza (15 [6%]), vomiting (13 [5%]), arthralgia (11 [5%]), irritability (ten [4%]), fatigue (eight [3%]), and insomnia (eight [3%]).

Interpretation: Laquinimod did not show a significant effect on motor symptoms assessed by the UHDRS-TMS, but significantly reduced caudate volume loss compared with placebo at week 52. Huntington's disease has a chronic and slowly progressive course, and this study does not address whether a longer duration of laquinimod treatment could have produced detectable and meaningful changes in the clinical assessments.

Reilmann R, Anderson KE, Feigin A, Tabrizi SJ, Leavitt BR, Stout JC, Piccini P, Schubert R, Loupe P, Wickenberg A, Borowsky B, Rynkowski G, Volkinshtein R, Li T, Savola JM, Hayden M, Gordon MF; LEGATO-HD Study Group. Safety and efficacy of laquinimod for Huntington's disease (LEGATO-HD): a multicentre, randomised, double-blind, placebo-controlled, phase 2 study. Lancet Neurol. 2024 Jan 24:S1474-4422(23)00454-4. doi: 10.1016/S1474-4422(23)00454-4. Epub ahead of print. PMID: 38280392.

Journal: Journal of Controlled Release

Efficient delivery of therapeutics to the central nervous system (CNS) remains a major challenge for the treatment of neurological diseases. Huntington disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG trinucleotide expansion mutation in the HTT gene which codes for a toxic mutant huntingtin (mHTT) protein. Pharmacological reduction of mHTT in the CNS using antisense oligonucleotides (ASO) ameliorates HD-like phenotypes in rodent models of HD, with such therapies being investigated in clinical trials for HD. In this study, we report the optimization of apolipoprotein A-I nanodisks (apoA-I NDs) as vehicles for delivery of a HTT-targeted ASO (HTT ASO) to the brain and peripheral organs for HD. We demonstrate that apoA-I wild type (WT) and the apoA-I K133C mutant incubated with a synthetic lipid, 1,2-dimyristoyl-sn-glycero-3-phosphocholine, can self-assemble into monodisperse discoidal particles with diameters <20 nm that transmigrate across an in vitro blood-brain barrier model of HD. We demonstrate that apoA-I NDs are well tolerated in vivo, and that apoA-I K133C NDs show enhanced distribution to the CNS and peripheral organs compared to apoA-I WT NDs following systemic administration. ApoA-I K133C conjugated with HTT ASO forms NDs (HTT ASO NDs) that induce significant mHTT lowering in the liver, skeletal muscle and heart as well as in the brain when delivered intravenously in the BACHD mouse model of HD. Furthermore, HTT ASO NDs increase the magnitude of mHTT lowering in the striatum and cortex compared to HTT ASO alone following intracerebroventricular administration. These findings demonstrate the potential utility of apoA-I NDs as biocompatible vehicles for enhancing delivery of mutant HTT lowering ASOs to the CNS and peripheral organs for HD.

Caron NS, Aly AE, Findlay Black H, Martin DDO, Schmidt ME, Ko S, Anderson C, Harvey EM, Casal LL, Anderson LM, Rahavi SMR, Reid GSD, Oda MN, Stanimirovic D, Abulrob A, McBride JL, Leavitt BR, Hayden MR. Systemic delivery of mutant huntingtin lowering antisense oligonucleotides to the brain using apolipoprotein A-I nanodisks for Huntington disease. J Control Release. 2024 Jan 24;367:27-44. doi: 10.1016/j.jconrel.2024.01.011. Epub ahead of print. PMID: 38215984.

Journal: Journal of Cell Biology

Cardoen B, Vandevoorde KR, Gao G, Ortiz-Silva M, Alan P, Liu W, Tiliakou E, Vogl AW, Hamarneh G, Nabi IR. Membrane contact site detection (MCS-DETECT) reveals dual control of rough mitochondria-ER contacts. J Cell Biol. 2024 Jan 1;223(1):e202206109. doi: 10.1083/jcb.202206109. Epub 2023 Nov 10. PMID: 37948126; PMCID: PMC10638097.

Journal: Trends in Neurosciences

Movement disorders such as Parkinson's disease (PD) impact oculomotor function - the ability to move the eyes accurately and purposefully to serve a multitude of sensory, cognitive, and secondary motor tasks. Decades of neurophysiological research in monkeys and behavioral studies in humans have characterized the neural basis of healthy oculomotor control. This review links eye movement abnormalities in persons living with PD to the underlying neurophysiological mechanisms and pathways. Building on this foundation, we highlight recent progress in using eye movements to gauge symptom severity, assess treatment effects, and serve as potential precision biomarkers. We conclude that whereas eye movements provide insights into PD mechanisms, based on current evidence they appear to lack sufficient sensitivity and specificity to serve as a standalone diagnostic tool. Their full potential may be realized when combined with other disease indicators in big datasets.

Antoniades CA, Spering M. Eye movements in Parkinson's disease: from neurophysiological mechanisms to diagnostic tools. Trends Neurosci. 2024 Jan;47(1):71-83. doi: 10.1016/j.tins.2023.11.001. Epub 2023 Dec 2. PMID: 38042680.

Journal: Clinical & Experimental Optometry

Recent advances have led to therapeutic options becoming available for people with inherited retinal disease. In particular, gene therapy has been shown to hold great promise for slowing vision loss from inherited retinal disease. Recent studies suggest that gene therapy is likely to be most effective when implemented early in the disease process, making consideration of paediatric populations important. It is therefore necessary to have a comprehensive understanding of retinal imaging in children with inherited retinal diseases, in order to monitor disease progression and to determine which early retinal biomarkers may be used as outcome measures in future clinical trials. In addition, as many optometrists will review children with an inherited retinal disease, an understanding of the expected imaging outcomes can improve clinical care. This review focuses on the most common imaging modality used in research assessment of paediatric inherited retinal diseases: optical coherence tomography. Optical coherence tomography findings can be used in both the clinical and research setting. In particular, the review discusses current knowledge of optical coherence tomography findings in eight paediatric inherited retinal diseases - Stargardt disease, Bests disease, Leber's congenital amaurosis, choroideremia, RPGR related retinitis pigmentosa, Usher syndrome, X-linked retinoschisis and, Batten disease.

Jolly JK, Rodda BM, Edwards TL, Ayton LN, Ruddle JB. Optical coherence tomography in children with inherited retinal disease. Clin Exp Optom. 2024 Jan 22:1-12. doi: 10.1080/08164622.2023.2294807. Epub ahead of print. PMID: 38252959.

Journal: Acta Ophthalmologica

McGuinness MB, Ayton LN, Schofield D, Britten-Jones AC, Chen FK, Grigg JR, Qi Z, Kraindler J, Shrestha R, Mack HG. EQ-5D-5L health utility scores in Australian adults with inherited retinal diseases: A cross-sectional survey. Acta Ophthalmol. 2024 Jan 16. doi: 10.1111/aos.16634. Epub ahead of print. PMID: 38226448.

Journal: Survey of Ophthalmology

Adaptive optics (AO) imaging enables direct, objective assessments of retinal cells. Applications of AO show great promise in advancing our understanding of the etiology of inherited retinal disease (IRDs) and discovering new imaging biomarkers. This scoping review systematically identifies and summarizes clinical studies evaluating AO imaging in IRDs. Ovid MEDLINE and EMBASE were searched on February 6, 2023. Studies describing AO imaging in monogenic IRDs were included. Study screening and data extraction were performed by 2 reviewers independently. This review presents (1) a broad overview of the dominant areas of research; (2) a summary of IRD characteristics revealed by AO imaging; and (3) a discussion of methodological considerations relating to AO imaging in IRDs. From 140 studies with AO outcomes, including 2 following subretinal gene therapy treatments, 75% included fewer than 10 participants with AO imaging data. Of 100 studies that included participants' genetic diagnoses, the most common IRD genes with AO outcomes are CNGA3, CNGB3, CHM, USH2A, and ABCA4. Confocal reflectance AO scanning laser ophthalmoscopy was the most reported imaging modality, followed by flood-illuminated AO and split-detector AO. The most common outcome was cone density, reported quantitatively in 56% of studies. Future research areas include guidelines to reduce variability in the reporting of AO methodology and a focus on functional AO techniques to guide the development of therapeutic interventions.

Britten-Jones AC, Thai L, Flanagan JPM, Bedggood PA, Edwards TL, Metha AB, Ayton LN. Adaptive optics imaging in inherited retinal diseases: A scoping review of the clinical literature. Surv Ophthalmol. 2024 Jan-Feb;69(1):51-66. doi: 10.1016/j.survophthal.2023.09.006. Epub 2023 Sep 29. PMID: 37778667.

Journal: Journal of Alzheimer's Disease

Background: Prognosis of future risk of dementia from neuroimaging and cognitive data is important for optimizing clinical management for patients at early stage of Alzheimer's disease (AD). However, existing studies lack an efficient way to integrate longitudinal information from both modalities to improve prognosis performance.

Objective: In this study, we aim to develop and evaluate an explainable deep learning-based framework to predict mild cognitive impairment (MCI) to AD conversion within four years using longitudinal whole-brain 3D MRI and neurocognitive tests.

Methods: We proposed a two-stage framework that first uses a 3D convolutional neural network to extract single-timepoint MRI-based AD-related latent features, followed by multi-modal longitudinal feature concatenation and a 1D convolutional neural network to predict the risk of future dementia onset in four years.

Results: The proposed deep learning framework showed promising to predict MCI to AD conversion within 4 years using longitudinal whole-brain 3D MRI and cognitive data without extracting regional brain volumes or cortical thickness, reaching a balanced accuracy of 0.834, significantly improved from models trained from single timepoint or single modality. The post hoc model explainability revealed heatmap indicating regions that are important for predicting future risk of AD.

Conclusions: The proposed framework sets the stage for future studies for using multi-modal longitudinal data to achieve optimal prediction for prognosis of AD onset, leading to better management of the diseases, thereby improving the quality of life.

Bapat R, Ma D, Duong TQ. Predicting Four-Year's Alzheimer's Disease Onset Using Longitudinal Neurocognitive Tests and MRI Data Using Explainable Deep Convolutional Neural Networks. J Alzheimers Dis. 2024;97(1):459-469. doi: 10.3233/JAD-230893. PMID: 38143361.