Imperial College London

ProfessorDominicWithers

Faculty of MedicineInstitute of Clinical Sciences

Clinical Chair in Diabetes & Endocrinology
 
 
 
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d.withers

 
 
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Hammersmith HospitalHammersmith Campus

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Summary

 

Publications

Publication Type
Year
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127 results found

Duran I, Pombo J, Sun B, Gallage S, Kudo H, McHugh D, Bousset L, Barragan Avila JE, Forlano R, Manousou P, Heikenwalder M, Withers DJ, Vernia S, Goldin RD, Gil Jet al., 2024, Detection of senescence using machine learning algorithms based on nuclear features, Nature Communications, Vol: 15, Pages: 1-20, ISSN: 2041-1723

Cellular senescence is a stress response with broad pathophysiological implications. Senotherapies can induce senescence to treat cancer or eliminate senescent cells to ameliorate ageing and age-related pathologies. However, the success of senotherapies is limited by the lack of reliable ways to identify senescence. Here, we use nuclear morphology features of senescent cells to devise machine-learning classifiers that accurately predict senescence induced by diverse stressors in different cell types and tissues. As a proof-of-principle, we use these senescence classifiers to characterise senolytics and to screen for drugs that selectively induce senescence in cancer cells but not normal cells. Moreover, a tissue senescence score served to assess the efficacy of senolytic drugs and identified senescence in mouse models of liver cancer initiation, ageing, and fibrosis, and in patients with fatty liver disease. Thus, senescence classifiers can help to detect pathophysiological senescence and to discover and validate potential senotherapies.

Journal article

McHugh D, Sun B, Gutierrez-Muñoz C, Hernández-González F, Mellone M, Guiho R, Duran I, Pombo J, Pietrocola F, Birch J, Kallemeijn WW, Khadayate S, Dharmalingam G, Vernia S, Tate EW, Martínez-Barbera JP, Withers DJ, Thomas GJ, Serrano M, Gil Jet al., 2023, COPI vesicle formation and N-myristoylation are targetable vulnerabilities of senescent cells, Nature Cell Biology, Vol: 25, Pages: 1804-1820, ISSN: 1465-7392

Drugs that selectively kill senescent cells (senolytics) improve the outcomes of cancer, fibrosis and age-related diseases. Despite their potential, our knowledge of the molecular pathways that affect the survival of senescent cells is limited. To discover senolytic targets, we performed RNAi screens and identified coatomer complex I (COPI) vesicle formation as a liability of senescent cells. Genetic or pharmacological inhibition of COPI results in Golgi dispersal, dysfunctional autophagy, and unfolded protein response-dependent apoptosis of senescent cells, and knockdown of COPI subunits improves the outcomes of cancer and fibrosis in mouse models. Drugs targeting COPI have poor pharmacological properties, but we find that N-myristoyltransferase inhibitors (NMTi) phenocopy COPI inhibition and are potent senolytics. NMTi selectively eliminated senescent cells and improved outcomes in models of cancer and non-alcoholic steatohepatitis. Our results suggest that senescent cells rely on a hyperactive secretory apparatus and that inhibiting trafficking kills senescent cells with the potential to treat various senescence-associated diseases.

Journal article

Millership SJ, Yu V, Yong F, Georgiadou E, Marchetti P, Dhawan S, Withers DJ, Rutter GAet al., 2023, Epigenetic beta cell functional heterogeneity during postnatal islet development via the imprinted gene neuronatin, Publisher: WILEY, ISSN: 0742-3071

Conference paper

Baghdadi M, Nespital T, Mesaros A, Buschbaum S, Withers DJ, Gronke S, Partridge Let al., 2023, Reduced insulin signaling in neurons induces sex-specific health benefits, SCIENCE ADVANCES, Vol: 9, ISSN: 2375-2548

Journal article

Crombie EM, Kim S, Adamson S, Dong H, Lu T-C, Wu Y, Wu Y, Levy Y, Stimple N, Lam WMR, Hey HWD, Withers DJ, Hsu A-L, Bay BH, Ochala J, Tsai S-Yet al., 2023, Activation of eIF4E-binding-protein-1 rescues mTORC1-induced sarcopenia by expanding lysosomal degradation capacity, JOURNAL OF CACHEXIA SARCOPENIA AND MUSCLE, Vol: 14, Pages: 198-213, ISSN: 2190-5991

Journal article

Ang S-TJ, Crombie EMM, Dong H, Tan K-T, Hernando A, Yu D, Adamson S, Kim S, Withers DJJ, Huang H, Tsai S-Yet al., 2022, Muscle 4EBP1 activation modifies the structure and function of the neuromuscular junction in mice, NATURE COMMUNICATIONS, Vol: 13

Journal article

Halff EF, Natesan S, Bonsall DR, Veronese M, Garcia-Hidalgo A, Kokkinou M, Tang S-P, Riggall LJ, Gunn RN, Irvine EE, Withers DJ, Wells LA, Howes ODet al., 2022, Evaluation of Intraperitoneal [<SUP>18</SUP>F]-FDOPA Administration for Micro-PET Imaging in Mice and Assessment of the Effect of Subchronic Ketamine Dosing on Dopamine Synthesis Capacity, MOLECULAR IMAGING, Vol: 2022

Journal article

Baghdadi M, Nespital T, Mesaros A, Buschbaum S, Withers DJ, Grönke S, Partridge Let al., 2022, Reduced insulin signalling in neurons induces sex-specific health benefits

<jats:title>Abstract</jats:title><jats:p>Reduced activity of the insulin/IGF signalling (IIS) network extends healthspan and lifespan in mammals and possibly humans. Loss of the Irs1 gene increases survival in mice and causes tissue-specific changes in gene expression. However, the tissues underlying IIS mediated longevity are currently unknown. Here we measured survival and healthspan in male and female animals lacking Irs1 activity specifically in the liver, muscle, fat and brain. Tissue-specific loss of IRS1 did not increase survival, suggesting that lack of Irs1 in more than one tissue is required for lifespan extension. Furthermore, loss of Irs1 in liver, muscle and fat did not improve health at old age. In contrast, loss of neuronal Irs1 increased energy expenditure, locomotion and insulin sensitivity, specifically in old males. Neuronal loss of IRS1 also caused male-specific mitochondrial dysfunction, activation of Atf4 and metabolic adaptations consistent with an activated integrated stress response at old age. Thus, we identified a male-specific brain signature of ageing in response to reduced IIS associated with improved health outcomes at old age.</jats:p>

Journal article

Malehmir M, Pfister D, Gallage S, Szydlowska M, Inverso D, Kotsiliti E, Leone V, Peiseler M, Surewaard BGJ, Rath D, Ali A, Wolf MJ, Drescher H, Healy ME, Dauch D, Kroy D, Krenkel O, Kohlhepp M, Engleitner T, Olkus A, Sijmonsma T, Volz J, Deppermann C, Stegner D, Helbling P, Nombela-Arrieta C, Rafiei A, Hinterleitner M, Rall M, Baku F, Borst O, Wilson CL, Leslie J, O'Connor T, Weston CJ, Chauhan A, Adams DH, Sheriff L, Teijeiro A, Prinz M, Bogeska R, Anstee N, Bongers MN, Notohamiprodjo M, Geisler T, Withers DJ, Ware J, Mann DA, Augustin HG, Vegiopoulos A, Milsom MD, Rose AJ, Lalor PF, Llovet JM, Pinyol R, Tacke F, Rad R, Matter M, Djouder N, Kubes P, Knolle PA, Unger K, Zender L, Nieswandt B, Gawaz M, Weber A, Heikenwalder Met al., 2022, Platelet GPIb alpha is a mediator and potential interventional target for NASH and subsequent liver cancer (vol 25, pg 641, 2019), NATURE MEDICINE, Vol: 28, Pages: 600-600, ISSN: 1078-8956

Journal article

Gallage S, Ali A, Barragan Avila JE, Herebian D, Karimi MM, Irvine EE, McHugh D, Schneider AT, Vucur M, Keitel V, Gil J, Withers DJ, Luedde T, Heikenwalder Met al., 2021, Spontaneous cholemia in C57BL/6 mice predisposes to liver cancer in NASH, Cellular and Molecular Gastroenterology and Hepatology, Vol: 13, Pages: 875-878, ISSN: 2352-345X

Journal article

Ninkina N, Millership SJ, Peters OM, Connor-Robson N, Chaprov K, Kopylov AT, Montoya A, Kramer H, Withers DJ, Buchman VLet al., 2021, β-synuclein potentiates synaptic vesicle dopamine uptake and rescues dopaminergic neurons from MPTP-induced death in the absence of other synucleins., Journal of Biological Chemistry, Vol: 297, Pages: 1-15, ISSN: 0021-9258

Synucleins, a family of three proteins highly expressed in neurons, are predominantly known for the direct involvement of α-synuclein in the aetiology and pathogenesis of Parkinson's and certain other neurodegenerative diseases, but their precise physiological functions are still not fully understood. Previous studies have demonstrated the importance of α-synuclein as a modulator of various mechanisms implicated in chemical neurotransmission, but information concerning the involvement of other synuclein family members, β-synuclein and γ-synuclein, in molecular processes within presynaptic terminals is limited. Here we demonstrated that the vesicular monoamine transporter 2 (VMAT2)-dependent dopamine uptake by synaptic vesicles isolated from the striatum of mice lacking β-synuclein is significantly reduced. Reciprocally, reintroduction, either in vivo or in vitro, of β-synuclein but not α- or γ-synuclein improves uptake by triple α/β/γ-synuclein deficient striatal vesicles. We also showed that the resistance of dopaminergic neurons of the substantia nigra pars compacta (SNpc) to subchronic administration of the Parkinson's disease-inducing prodrug 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) depends on the presence of β-synuclein but only when one or both other synucleins are absent. Furthermore, proteomic analysis of synuclein-deficient synaptic vesicles vs those containing only β-synuclein revealed differences in their protein compositions. We suggest that the observed potentiation of dopamine uptake by β-synuclein might be caused by different protein architecture of the synaptic vesicles. It is also feasible that such structural changes improve synaptic vesicle sequestration of 1-methyl-4-phenylpyridinium (MPP+), a toxic metabolite of MPTP, which would explain why dopaminergic neurons expressing β-synuclein and lacking α-synuclein and/or γ-synuclein are resistant t

Journal article

Mousavy Gharavy SN, Owen BM, Millership SJ, Chabosseau P, Pizza G, Martinez-Sanchez A, Tasoez E, Georgiadou E, Hu M, Fine NHF, Jacobson DA, Dickerson MT, Idevall-Hagren O, Montoya A, Kramer H, Mehta Z, Withers DJ, Ninov N, Gadue PJ, Cardenas-Diaz FL, Cruciani-Guglielmacci C, Magnan C, Ibberson M, Leclerc I, Voz M, Rutter GAet al., 2021, Sexually dimorphic roles for the type 2 diabetes-associated C2cd4b gene in murine glucose homeostasis, Diabetologia, Vol: 64, Pages: 850-864, ISSN: 0012-186X

Aims/hypothesisVariants close to the VPS13C/C2CD4A/C2CD4B locus are associated with altered risk of type 2 diabetes in genome-wide association studies. While previous functional work has suggested roles for VPS13C and C2CD4A in disease development, none has explored the role of C2CD4B.MethodsCRISPR/Cas9-induced global C2cd4b-knockout mice and zebrafish larvae with c2cd4a deletion were used to study the role of this gene in glucose homeostasis. C2 calcium dependent domain containing protein (C2CD)4A and C2CD4B constructs tagged with FLAG or green fluorescent protein were generated to investigate subcellular dynamics using confocal or near-field microscopy and to identify interacting partners by mass spectrometry.ResultsSystemic inactivation of C2cd4b in mice led to marked, but highly sexually dimorphic changes in body weight and glucose homeostasis. Female C2cd4b mice displayed unchanged body weight compared with control littermates, but abnormal glucose tolerance (AUC, p = 0.01) and defective in vivo, but not in vitro, insulin secretion (p = 0.02). This was associated with a marked decrease in follicle-stimulating hormone levels as compared with wild-type (WT) littermates (p = 0.003). In sharp contrast, male C2cd4b null mice displayed essentially normal glucose tolerance but an increase in body weight (p < 0.001) and fasting blood glucose (p = 0.003) after maintenance on a high-fat and -sucrose diet vs WT littermates. No metabolic disturbances were observed after global inactivation of C2cd4a in mice, or in pancreatic beta cell function at larval stages in C2cd4a null zebrafish. Fasting blood glucose levels were also unaltered in adult C2cd4a-null fish. C2CD4B and C2CD4A were partially localised to the plasma membrane, with the latter under the control of intracellular Ca2+. Binding partners for both included secretory-granule-localised PTPRN2/phogrin.Conclusions/interpretationOur studies sugge

Journal article

Jarvis S, Gethings LA, Samanta L, Pedroni SMA, Withers DJ, Gray N, Plumb RS, Winston RML, Williamson C, Bevan CLet al., 2020, High fat diet causes distinct aberrations in the testicular proteome, International Journal of Obesity, Vol: 44, Pages: 1958-1969, ISSN: 0307-0565

Diet has important effects on normal physiology and the potential deleterious effects of high fat diets and obesity on male reproductive health are being increasingly described. We conducted a histological review of the effects of chronic high fat (HF) diet (using a mouse model fed a 45% fat diet for 21 weeks) with a discovery proteomic study to assess for changes in the abundance of proteins in the testis. Mice on a HF diet became obese and developed glucose intolerance. Using mass spectrometry, we identify 102 proteins affected in the testis of obese mice. These included structural proteins important for the blood testis barrier (filamin A, FLNA), proteins involved in oxidative stress responses (spermatogenesis associated 20, SPATA-20) and lipid homoeostasis (sterol regulatory element-binding protein 2, SREBP2 and apolipoprotein A1, APOA1). In addition, an important regulator protein paraspeckle component 1, PSPC-1, which interacts with the androgen receptor was significantly downregulated. Proteomic data was validated using both Western blotting and immunostaining which confirmed and localised protein expression in both mouse and human testis using biopsy specimens. This study focused mainly on the abnormalities that occurred at the protein level and as a result, we have identified several candidate proteins and conducted pathway analysis around the effects of HF diet on the testis providing novel insights not previously described. Some of the identified targets could be targeted therapeutically and future work is directed in this area.

Journal article

Kokkinou M, Irvine EE, Bonsall DR, Natesan S, Wells LA, Smith M, Glegola J, Paul EJ, Tossell K, Veronese M, Khadayate S, Dedic N, Hopkins SC, Ungless MA, Withers DJ, Howes ODet al., 2020, Reproducing the dopamine pathophysiology of schizophrenia and approaches to ameliorate it: a translational imaging study with ketamine, Molecular Psychiatry, Vol: 26, Pages: 2562-2576, ISSN: 1359-4184

Patients with schizophrenia show increased striatal dopamine synthesis capacity in imaging studies. The mechanism underlying this is unclear but may be due to N-methyl-D-aspartate receptor (NMDAR) hypofunction and parvalbumin (PV) neuronal dysfunction leading to disinhibition of mesostriatal dopamine neurons. Here, we develop a translational mouse model of the dopamine pathophysiology seen in schizophrenia and test approaches to reverse the dopamine changes. Mice were treated with sub-chronic ketamine (30 mg/kg) or saline and then received in vivo positron emission tomography of striatal dopamine synthesis capacity, analogous to measures used in patients. Locomotor activity was measured using the open-field test. In vivo cell-type-specific chemogenetic approaches and pharmacological interventions were used to manipulate neuronal excitability. Immunohistochemistry and RNA sequencing were used to investigate molecular mechanisms. Sub-chronic ketamine increased striatal dopamine synthesis capacity (Cohen’s d = 2.5) and locomotor activity. These effects were countered by inhibition of midbrain dopamine neurons, and by activation of PV interneurons in pre-limbic cortex and ventral subiculum of the hippocampus. Sub-chronic ketamine reduced PV expression in these cortical and hippocampal regions. Pharmacological intervention with SEP-363856, a novel psychotropic agent with agonism at trace amine receptor 1 (TAAR1) and 5-HT1A receptors but no appreciable action at dopamine D2 receptors, significantly reduced the ketamine-induced increase in dopamine synthesis capacity. These results show that sub-chronic ketamine treatment in mice mimics the dopaminergic alterations in patients with psychosis, that this requires activation of midbrain dopamine neurons, and can be ameliorated by activating PV interneurons and by a TAAR1/5-HT1A agonist. This identifies novel therapeutic approaches for targeting presynaptic dopamine dysfunction in patients with schiz

Journal article

Guerrero A, Guiho R, Herranz N, Uren A, Withers DJ, Martínez-Barbera JP, Tietze LF, Gil Jet al., 2020, Galactose-modified duocarmycin prodrugs as senolytics, Aging Cell, Vol: 19, Pages: 1-13, ISSN: 1474-9718

Senescence is a stable growth arrest that impairs the replication of damaged, old or preneoplastic cells, therefore contributing to tissue homeostasis. Senescent cells accumulate during ageing and are associated with diseases, such as cancer, fibrosis and many age-related pathologies. Recent evidence suggests that the selective elimination of senescent cells can be effective on the treatment of many of these senescence-associated diseases. A universal characteristic of senescent cells is that they display elevated activity of the lysosomal β-galactosidase this has been exploited as a marker for senescence (senescence-associated β-galactosidase activity). Consequently, we hypothesised that galactose-modified cytotoxic prodrugs will be preferentially processed by senescent cells, resulting in their selective killing. Here, we show that different galactose-modified duocarmycin (GMD) derivatives preferentially kill senescent cells. GMD prodrugs induce selective apoptosis of senescent cells in a lysosomal β-galactosidase (GLB1)-dependent manner. GMD prodrugs can eliminate a broad range of senescent cells in culture, and treatment with a GMD prodrug enhances the elimination of bystander senescent cells that accumulate upon whole body irradiation or doxorubicin treatment of mice. Moreover, taking advantage of a mouse model of human adamantinomatous craniopharyngioma (ACP), we show that treatment with a GMD pro-drug result selectively reduced the number of β-catenin-positive preneoplastic senescent cells, what could have therapeutic implications. In summary, the above results show that galactose-modified duocarmycin prodrugs behave as senolytics, suggesting that they could be used to treat a wide range of senescence-related pathologies.</jats:p>

Journal article

Smith MA, Choudhury AI, Glegola JA, Viskaitis P, Irvine EE, Caldas Custodio de Campos Silva P, Khadayate S, Zeilhofer HU, Withers DJet al., 2020, Extrahypothalamic GABAergic nociceptin-expressing neurons regulate AgRP neuron activity to control feeding behavior, Journal of Clinical Investigation, Vol: 130, Pages: 126-142, ISSN: 0021-9738

Arcuate nucleus agouti-related peptide (AgRP) neurons play a central role in feeding and are under complex regulation by both homeostatic hormonal and nutrient signals and hypothalamic neuronal pathways. Feeding may also be influenced by environmental cues, sensory inputs and other behaviors implying the involvement of higher brain regions. However, whether such pathways modulate feeding through direct synaptic control of AgRP neuron activity is unknown. Here we show that nociceptin-expressing neurons in the anterior bed nuclei of the stria terminalis (aBNST) make direct GABAergic inputs onto AgRP neurons. We found that activation of these neurons inhibited AgRP neurons and feeding. Activity of these neurons increased upon food availability and their ablation resulted in obesity. Furthermore, these neurons received afferent inputs from a range of upstream brain regions as well as hypothalamic nuclei. Therefore, aBNST nociceptin/GABAergic neurons may act as a gateway to feeding behavior by connecting AgRP neurons to both homeostatic and non-homeostatic neuronal inputs.

Journal article

Kokkinou M, Irvine EE, Bonsall DR, Natesan S, Wells LA, Smith MA, Glegola J, Paul EJ, Tossell K, Veronese M, Ungless MA, Withers DJ, Howes Oet al., 2019, Circuit Mechanism Mediates Sub-Chronic Ketamine-Induced Increase in Dopamine Synthesis, 58th Annual Meeting of the American-College-of-Neuropsychopharmacology (ACNP), Publisher: NATURE PUBLISHING GROUP, Pages: 170-170, ISSN: 0893-133X

Conference paper

Irvine E, Katsouri L, Plattner F, Al-Qassab H, Al-Nackkash R, Bates G, Withers Det al., 2019, Genetic deletion of S6k1 does not rescue the phenotypic deficits observed in the R6/2 mouse model of Huntington’s disease, Scientific Reports, Vol: 9, ISSN: 2045-2322

Huntington’s disease (HD) is a fatal inherited autosomal dominant neurodegenerative disorder caused by an expansion in the number of CAG trinucleotide repeats in the huntingtin gene. The disease is characterized by motor, behavioural and cognitive symptoms for which at present there are no disease altering treatments. It has been shown that manipulating the mTOR (mammalian target of rapamycin) pathway using rapamycin or its analogue CCI-779 can improve the cellular and behavioural phenotypes of HD models. Ribosomal protein S6 kinase 1 (S6K1) is a major downstream signalling molecule of mTOR, and its activity is reduced by rapamycin suggesting that deregulation of S6K1 activity may be beneficial in HD. Furthermore, S6k1 knockout mice have increased lifespan and improvement in age-related phenotypes. To evalute the potential benefit of S6k1 loss on HD-related phenotypes, we crossed the R6/2 HD model with the long-lived S6k1 knockout mouse line. We found that S6k1 knockout does not ameliorate behavioural or physiological phenotypes in the R6/2 mouse model. Additionally, no improvements were seen in brain mass reduction or huntingtin protein aggregate levels. Therefore, these results suggest that while a reduction in S6K1 signalling has beneficial effects on ageing it is unlikely to be a therapeutic strategy for HD patients.

Journal article

Guerrero A, Herranz N, Sun B, Wagner V, Gallage S, Guiho R, Wolter K, Pombo J, Irvine EE, Innes AJ, Birch J, Glegola J, Manshaei S, Heide D, Dharmalingam G, Harbig J, Olona A, Behmoaras J, Dauch D, Uren AG, Zender L, Vernia S, Martínez-Barbera JP, Heikenwalder M, Withers DJ, Gil Jet al., 2019, Cardiac glycosides are broad-spectrum senolytics, Nature Metabolism, Vol: 1, Pages: 1074-1088, ISSN: 2522-5812

Senescence is a cellular stress response that results in the stable arrest of old, damaged or pre-neoplastic cells. Oncogene-induced senescence is tumour suppressive but can also exacerbate tumorigenesis through the secretion of proinflammatory factors from senescent cells. Drugs that selectively kill senescent cells, termed ‘senolytics’, have proved beneficial in animal models of many age-associated diseases. In the present study, we show that the cardiac glycoside ouabain is a senolytic agent with broad activity. Senescent cells are sensitized to ouabain-induced apoptosis, a process mediated in part by induction of the proapoptotic Bcl-2 family protein NOXA. We demonstrate that cardiac glycosides synergize with anti-cancer drugs to kill tumour cells and eliminate senescent cells that accumulate after irradiation or in old mice. Ouabain also eliminates senescent pre-neoplastic cells. The findings of the present study suggest that cardiac glycosides may be effective anti-cancer drugs by acting through multiple mechanisms. Given the broad range of senescent cells targeted by cardiac glycosides, their use against age-related diseases warrants further exploration.

Journal article

Millership SJ, Van de Pette M, Withers DJ, 2019, Genomic imprinting and its effects on postnatal growth and adult metabolism, Cellular and Molecular Life Sciences, Vol: 76, Pages: 4009-4021, ISSN: 1420-682X

Imprinted genes display parent-of-origin-specific expression with this epigenetic system of regulation found exclusively in therian mammals. Historically, defined imprinted gene functions were almost solely focused on pregnancy and the influence on the growth parameters of the developing embryo and placenta. More recently, a number of postnatal functions have been identified which converge on resource allocation, both for animals in the nest and in adults. While many of the prenatal functions of imprinted genes that have so far been described adhere to the "parental conflict" hypothesis, no clear picture has yet emerged on the functional role of imprints on postnatal metabolism. As these roles are uncovered, interest in the potential for these genes to influence postnatal metabolism and associated adult-onset disease outcomes when dysregulated has gathered pace. Here, we review the published data on imprinted genes and their influence on postnatal metabolism, starting in the nest, and then progressing through to adulthood. When observing the functional effects of these genes on adult metabolism, we must always be careful to acknowledge the influence both of direct expression in the relevant metabolic tissue, but also indirect metabolic programming effects caused by their modulation of both in utero and postnatal growth trajectories.

Journal article

Malehmir M, Pfister D, Gallage S, Szydlowska M, Inverso D, Kotsiliti E, Leone V, Peiseler M, Surewaard BGJ, Rath D, Ali A, Wolf MJ, Drescher H, Healy ME, Dauch D, Kroy D, Krenkel O, Kohlhepp M, Engleitner T, Olkus A, Sijmonsma T, Volz J, Deppermann C, Stegner D, Helbling P, Nombela-Arrieta C, Rafiei A, Hinterleitner M, Rall M, Baku F, Borst O, Wilson CL, Leslie J, O'Connor T, Weston CJ, Adams DH, Sheriff L, Teijeiro A, Prinz M, Bogeska R, Anstee N, Bongers MN, Notohamiprodjo M, Geisler T, Withers DJ, Ware J, Mann DA, Augustin HG, Vegiopoulos A, Milsom MD, Rose AJ, Lalor PF, Llovet JM, Pinyol R, Tacke F, Rad R, Matter M, Djouder N, Kubes P, Knolle PA, Unger K, Zender L, Nieswandt B, Gawaz M, Weber A, Heikenwalder Met al., 2019, Platelet GPIb alpha is a mediator and potential interventional target for NASH and subsequent liver cancer, Nature Medicine, Vol: 25, Pages: 641-655, ISSN: 1078-8956

Non-alcoholic fatty liver disease ranges from steatosis to non-alcoholic steatohepatitis (NASH), potentially progressing to cirrhosis and hepatocellular carcinoma (HCC). Here, we show that platelet number, platelet activation and platelet aggregation are increased in NASH but not in steatosis or insulin resistance. Antiplatelet therapy (APT; aspirin/clopidogrel, ticagrelor) but not nonsteroidal anti-inflammatory drug (NSAID) treatment with sulindac prevented NASH and subsequent HCC development. Intravital microscopy showed that liver colonization by platelets depended primarily on Kupffer cells at early and late stages of NASH, involving hyaluronan-CD44 binding. APT reduced intrahepatic platelet accumulation and the frequency of platelet–immune cell interaction, thereby limiting hepatic immune cell trafficking. Consequently, intrahepatic cytokine and chemokine release, macrovesicular steatosis and liver damage were attenuated. Platelet cargo, platelet adhesion and platelet activation but not platelet aggregation were identified as pivotal for NASH and subsequent hepatocarcinogenesis. In particular, platelet-derived GPIbα proved critical for development of NASH and subsequent HCC, independent of its reported cognate ligands vWF, P-selectin or Mac-1, offering a potential target against NASH.

Journal article

Rached M-T, Millership SJ, Pedroni SMA, Choudhury AI, Costa ASH, Hardy DG, Glegola JA, Irvine EE, Selman C, Woodberry MC, Yadav VK, Khadayate S, Vidal-Puig A, Virtue S, Frezza C, Withers Det al., 2019, Deletion of myeloid IRS2 enhances adipose tissue sympathetic nerve function and limits obesity, Molecular Metabolism, Vol: 20, Pages: 38-50, ISSN: 2212-8778

ObjectiveSympathetic nervous system and immune cell interactions play key roles in the regulation of metabolism. For example, recent convergent studies have shown that macrophages regulate obesity through brown adipose tissue (BAT) activation and beiging of white adipose tissue (WAT) via effects upon local catecholamine availability. However, these studies have raised issues about the underlying mechanisms involved including questions regarding the production of catecholamines by macrophages, the role of macrophage polarization state and the underlying intracellular signaling pathways in macrophages that might mediate these effects.MethodsTo address such issues we generated mice lacking Irs2, which mediates the effects of insulin and interleukin 4, specifically in LyzM expressing cells (Irs2LyzM−/− mice).ResultsThese animals displayed obesity resistance and preservation of glucose homeostasis on high fat diet feeding due to increased energy expenditure via enhanced BAT activity and WAT beiging. Macrophages per se did not produce catecholamines but Irs2LyzM−/− mice displayed increased sympathetic nerve density and catecholamine availability in adipose tissue. Irs2-deficient macrophages displayed an anti-inflammatory transcriptional profile and alterations in genes involved in scavenging catecholamines and supporting increased sympathetic innervation.ConclusionsOur studies identify a critical macrophage signaling pathway involved in the regulation of adipose tissue sympathetic nerve function that, in turn, mediates key neuroimmune effects upon systemic metabolism. The insights gained may open therapeutic opportunities for the treatment of obesity.

Journal article

Borgan F, O'Daly O, Hoang K, Veronese M, Withers D, Batterham R, Howes Oet al., 2019, Neural Responsivity to Food Cues in Patients With Unmedicated First-Episode Psychosis, JAMA NETWORK OPEN, Vol: 2, ISSN: 2574-3805

Journal article

Millership S, Tunster SJ, Van de Pette M, Choudhury A, Irvine E, Christian M, Fisher AG, John RM, Scott J, Withers DJet al., 2018, Neuronatin deletion causes postnatal growth restriction and adult obesity in 129S2/Sv mice, Molecular Metabolism, Vol: 18, Pages: 97-106, ISSN: 2212-8778

ObjectiveImprinted genes are crucial for the growth and development of fetal and juvenile mammals. Altered imprinted gene dosage causes a variety of human disorders, with growth and development during these crucial early stages strongly linked with future metabolic health in adulthood. Neuronatin (Nnat) is a paternally expressed imprinted gene found in neuroendocrine systems and white adipose tissue and is regulated by the diet and leptin. Neuronatin expression is downregulated in obese children and has been associated with stochastic obesity in C57BL/6 mice. However, our recent studies of Nnat null mice on this genetic background failed to display any body weight or feeding phenotypes but revealed a defect in glucose-stimulated insulin secretion due to the ability of neuronatin to potentiate signal peptidase cleavage of preproinsulin. Nnat deficiency in beta cells therefore caused a lack of appropriate storage and secretion of mature insulin.MethodsTo further explore the potential role of Nnat in the regulation of body weight and adiposity, we studied classical imprinting-related phenotypes such as placental, fetal, and postnatal growth trajectory patterns that may impact upon subsequent adult metabolic phenotypes.ResultsHere we find that, in contrast to the lack of any body weight or feeding phenotypes on the C57BL/6J background, deletion of Nnat in mice on 129S2/Sv background causes a postnatal growth restriction with reduced adipose tissue accumulation, followed by catch up growth after weaning. This was in the absence of any effect on fetal growth or placental development. In adult 129S2/Sv mice, Nnat deletion was associated with hyperphagia, reduced energy expenditure, and partial leptin resistance. Lack of neuronatin also potentiated obesity caused by either aging or high fat diet feeding.ConclusionsThe imprinted gene Nnat plays a key role in postnatal growth, adult energy homeostasis, and the pathogenesis of obesity via catch up growth effects, but this role

Journal article

Paul EJ, Kalk E, Tossell K, Irvine E, Franks NP, Wisden W, Withers DJ, Leiper JM, Ungless MAet al., 2018, nNOS-expressing neurons in the ventral tegmental area and substantia nigra pars compacta, eNeuro, Vol: 5, ISSN: 2373-2822

GABA neurons in the VTA and SNc play key roles in reward and aversion through their local inhibitory control of dopamine neuron activity and through long-range projections to several target regions including the nucleus accumbens. It is not clear whether some of these GABA neurons are dedicated local interneurons or if they all collateralize and send projections externally as well as making local synaptic connections. Testing between these possibilities has been challenging in the absence of interneuron-specific molecular markers. We hypothesized that one potential candidate might be neuronal nitric oxide synthase (nNOS), a common interneuronal marker in other brain regions. To test this, we used a combination of immunolabelling (including antibodies for nNOS that we validated in tissue from nNOS-deficient mice) and cell type-specific virus-based anterograde tracing in mice. We found that nNOS-expressing neurons, in the parabrachial pigmented (PBP) part of the VTA and the SNc were GABAergic and did not make detectable projections, suggesting they may be interneurons. In contrast, nNOS-expressing neurons in the rostral linear nucleus (RLi) were mostly glutamatergic and projected to a number of regions, including the lateral hypothalamus (LH), the ventral pallidum (VP), and the median raphe (MnR) nucleus. Taken together, these findings indicate that nNOS is expressed by neurochemically- and anatomically-distinct neuronal sub-groups in a sub-region-specific manner in the VTA and SNc.

Journal article

Smith MA, Katsouri L, Virtue S, Choudhury A, Vidal-Puig A, Ashford MLJ, Withers DJet al., 2018, Calcium channel CaV2.3 subunits regulate hepatic glucose production by modulating leptin-induced excitation of arcuate pro-opiomelanocortin neurons, Cell Reports, Vol: 25, Pages: 278-287, ISSN: 2211-1247

Leptin acts on hypothalamic pro-opiomelanocortin (POMC) neurons to regulate glucose homeostasis, but the precise mechanisms remain unclear. Here, we demonstrate that leptin-induced depolarization of POMC neurons is associated with the augmentation of a voltage-gated calcium (CaV) conductance with the properties of the “R-type” channel. Knockdown of the pore-forming subunit of the R-type (CaV2.3 or Cacna1e) conductance in hypothalamic POMC neurons prevented sustained leptin-induced depolarization. In vivo POMC-specific Cacna1e knockdown increased hepatic glucose production and insulin resistance, while body weight, feeding, or leptin-induced suppression of food intake were not changed. These findings link Cacna1e function to leptin-mediated POMC neuron excitability and glucose homeostasis and may provide a target for the treatment of diabetes.

Journal article

Millership S, Da Silva Xavier G, Choudhury A, Bertazzo S, Chabosseau PL, Pedroni SMA, Irvine E, Montoya A, Faull P, Taylor WR, Kerr-Conte J, Pattou F, Ferrer J, Christian M, John RM, Latreille M, Liu M, Rutter G, Scott J, Withers DJet al., 2018, Neuronatin regulates pancreatic beta cell insulin content and secretion, Journal of Clinical Investigation, Vol: 128, Pages: 3369-3381, ISSN: 0021-9738

Neuronatin (Nnat) is an imprinted gene implicated in human obesity and widely expressed in neuroendocrine and metabolic tissues in a hormone and nutrient-sensitive manner. However, its molecular and cellular functions and precise role in organismal physiology remain only partly defined. Here we demonstrate that mice lacking Nnat globally or specifically in β cells display impaired glucose-stimulated insulin secretion leading to defective glucose handling under conditions of nutrient-excess. In contrast, we report no evidence for any feeding or body weight phenotypes in global Nnat null mice. At the molecular level neuronatin augments insulin signal peptide cleavage by binding to the signal peptidase complex and facilitates translocation of the nascent preprohormone. Loss of neuronatin expression in β cells therefore reduces insulin content and blunts glucose-stimulated insulin secretion. Nnat expression, in turn, is glucose-regulated. This mechanism therefore represents a novel site of nutrient-sensitive control of β cell function and whole animal glucose homeostasis. These data also suggest a potential wider role for Nnat in the regulation of metabolism through the modulation of peptide processing events.

Journal article

Page MM, Schuster EF, Mudaliar M, Herzyk P, Withers DJ, Selman Cet al., 2018, Common and unique transcriptional responses to dietary restriction and loss of insulin receptor substrate 1 (IRS1) in mice, Aging, Vol: 10, Pages: 1027-1052, ISSN: 1945-4589

Dietary restriction (DR) is the most widely studied non-genetic intervention capable of extending lifespan across multiple taxa. Modulation of genes, primarily within the insulin/insulin-like growth factor signalling (IIS) and the mechanistic target of rapamycin (mTOR) signalling pathways also act to extend lifespan in model organisms. For example, mice lacking insulin receptor substrate-1 (IRS1) are long-lived and protected against several age-associated pathologies. However, it remains unclear how these particular interventions act mechanistically to produce their beneficial effects. Here, we investigated transcriptional responses in wild-type and IRS1 null mice fed an ad libitum diet (WTAL and KOAL) or fed a 30% DR diet (WTDR or KODR). Using an RNAseq approach we noted a high correlation coefficient of differentially expressed genes existed within the same tissue across WTDR and KOAL mice and many metabolic features were shared between these mice. Overall, we report that significant overlap exists in the tissue-specific transcriptional response between long-lived DR mice and IRS1 null mice. However, there was evidence of disconnect between transcriptional signatures and certain phenotypic measures between KOAL and KODR, in that additive effects on body mass were observed but at the transcriptional level DR induced a unique set of genes in these already long-lived mice.

Journal article

Sandhu EC, Fernando ABP, Irvine E, Tossell K, Kokkinou M, Glegola J, Smith M, Howes O, Withers DJ, Ungless MAet al., 2018, Phasic stimulation of midbrain dopamine neuron activity reduces salt consumption, eNeuro, Vol: 5, ISSN: 2373-2822

Salt intake is an essential dietary requirement, but excessive consumption is implicated in hypertension and associated conditions. Little is known about the neural circuit mechanisms that control motivation to consume salt, although the midbrain dopamine system, which plays a key role in other reward-related behaviours, has been implicated. We, therefore, examined the effects on salt consumption of either optogenetic excitation or chemogenetic inhibition of ventral tegmental area (VTA) dopamine neurons in male mice. Strikingly, optogenetic excitation of dopamine neurons decreased salt intake in a rapid and reversible manner, despite a strong salt appetite. Importantly, optogenetic excitation was not aversive, did not induce hyperactivity, and did not alter salt concentration preferences in a need-free state. In addition, we found that chemogenetic inhibition of dopamine neurons had no effect on salt intake. Lastly, optogenetic excitation of dopamine neurons reduced consumption of sucrose following an overnight fast, suggesting a more general role of VTA dopamine neuron excitation in organising motivated behaviors.

Journal article

Viskaitis P, Irvine EE, Smith MA, Choudhury AI, Alvarez-Curto E, Glegola JA, Hardy DG, Pedroni SMA, Paiva Pessoa MR, Fernando ABP, Katsouri L, Sardini A, Ungless MA, Milligan G, Withers DJet al., 2017, Modulation of SF1 neuron activity co-ordinately regulates both feeding behaviour and associated emotional states, Cell Reports, Vol: 21, Pages: 3559-3572, ISSN: 2211-1247

Feeding requires the integration of homeostatic drives with emotional states relevant to food procurement in potentially hostile environments. The ventromedial hypothalamus (VMH) regulates feeding and anxiety, but how these are controlled in a concerted manner remains unclear. Using pharmacogenetic, optogenetic, and calcium imaging approaches with a battery of behavioral assays, we demonstrate that VMH steroidogenic factor 1 (SF1) neurons constitute a nutritionally sensitive switch, modulating the competing motivations of feeding and avoidance of potentially dangerous environments. Acute alteration of SF1 neuronal activity alters food intake via changes in appetite and feeding-related behaviors, including locomotion, exploration, anxiety, and valence. In turn, intrinsic SF1 neuron activity is low during feeding and increases with both feeding termination and stress. Our findings identify SF1 neurons as a key part of the neurocircuitry that controls both feeding and related affective states, giving potential insights into the relationship between disordered eating and stress-associated psychological disorders in humans.

Journal article

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