New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Oncostatin M protects against demyelination by inducing a protective microglial phenotype

Multiple sclerosis (MS) is a chronic disabling disease of the central nervous system (CNS), in which destruction of myelin sheaths leads to disturbed axonal conduction. Available MS therapies modulate the immune response, but are unable to prevent neurological decline. Therefore, great efforts are made to develop therapies that limit demyelination and axonal degeneration. Oncostatin M (OSM), a member of the interleukin (IL)-6 cytokine family, is produced in demyelinating lesions of MS patients and stimulates neuronal survival. In this study, we reveal that the OSM receptor (OSMR) was robustly upregulated on microglia/macrophages and astrocytes in the cuprizone-induced demyelination model. While OSMR deficiency led to aggravated demyelination, CNS-targeted OSM treatment largely prevented demyelination. OSM treatment increased IL-4 expression and induced polarization of myeloid cells towards an anti-inflammatory M2 phenotype in vivo. This study reveals a previously uncharacterized and protective role for OSM during demyelination, and indicates that OSM is a promising therapeutic candidate to limit CNS damage in demyelinating diseases including MS. GLIA 2015;63:1729-1737.status: publishe

Leukemia inhibitory factor tips the immune balance towards regulatory T cells in multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS), for which current treatments are unable to prevent disease progression. Based on its neuroprotective and neuroregenerating properties, leukemia inhibitory factor (LIF), a member of the interleukin-6 (IL-6) cytokine family, is proposed as a novel candidate for MS therapy. However, its effect on the autoimmune response remains unclear. In this study, we determined how LIF modulates T cell responses that play a crucial role in the pathogenesis of MS. We demonstrate that expression of the LIF receptor was strongly increased on immune cells of MS patients. LIF treatment potently boosted the number of regulatory T cells (Tregs) in CD4+ T cells isolated from healthy controls and MS patients with low serum levels of IL-6. Moreover, IL-6 signaling was reduced in the donors that responded to LIF treatment in vitro. Our data together with previous findings revealing that IL-6 inhibits Treg development, suggest an opposing function of LIF and IL-6. In a preclinical animal model of MS we shifted the LIF/IL-6 balance in favor of LIF by CNS-targeted overexpression. This increased the number of Tregs in the CNS during active autoimmune responses and reduced disease symptoms. In conclusion, our data show that LIF downregulates the autoimmune response by enhancing Treg numbers, providing further impetus for the use of LIF as a novel treatment for MS and other autoimmune diseases

Local Overexpression of Interleukin-11 in the Central Nervous System Limits Demyelination and Enhances Remyelination

Demyelination is one of the pathological hallmarks of multiple sclerosis (MS). To date, no therapy is available which directly potentiates endogenous remyelination. Interleukin-11 (IL-11), a member of the gp130 family of cytokines, is upregulated in MS lesions. Systemic IL-11 treatment was shown to ameliorate clinical symptoms in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. IL-11 modulates immune cells and protects oligodendrocytes in vitro. In this study, the cuprizone-induced demyelination mouse model was used to elucidate effects of IL-11 on de- and remyelination, independent of the immune response. Prophylactic-lentiviral- (LV-) mediated overexpression of IL-11 in mouse brain significantly limited acute demyelination, which was accompanied with the preservation of CC1+ mature oligodendrocytes (OLs) and a decrease in microglial activation (Mac-2+). We further demonstrated that IL-11 directly reduces myelin phagocytosis in vitro. When IL-11 expressing LV was therapeutically applied in animals with extensive demyelination, a significant enhancement of remyelination was observed as demonstrated by Luxol Fast Blue staining and electron microscopy imaging. Our results indicate that IL-11 promotes maturation of NG2+ OPCs into myelinating CC1+ OLs and may thus explain the enhanced remyelination. Overall, we demonstrate that IL-11 is of therapeutic interest for MS and other demyelinating diseases by limiting demyelination and promoting remyelination

Leukemia inhibitory factor tips the immune balance towards regulatory T cells in multiple sclerosis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS), for which current treatments are unable to prevent disease progression. Based on its neuroprotective and neuroregenerating properties, leukemia inhibitory factor (LIF), a member of the interleukin-6 (IL-6) cytokine family, is proposed as a novel candidate for MS therapy. However, its effect on the autoimmune response remains unclear. In this study, we determined how LIF modulates T cell responses that play a crucial role in the pathogenesis of MS. We demonstrate that expression of the LIF receptor was strongly increased on immune cells of MS patients. LIF treatment potently boosted the number of regulatory T cells (Tregs) in CD4(+) T cells isolated from healthy controls and MS patients with low serum levels of IL-6. Moreover, IL-6 signaling was reduced in the donors that responded to LIF treatment in vitro. Our data together with previous findings revealing that IL-6 inhibits Treg development, suggest an opposing function of LIF and IL-6. In a preclinical animal model of MS we shifted the LIF/IL-6 balance in favor of LIF by CNS-targeted overexpression. This increased the number of Tregs in the CNS during active autoimmune responses and reduced disease symptoms. In conclusion, our data show that LIF downregulates the autoimmune response by enhancing Treg numbers, providing further impetus for the use of LIF as a novel treatment for MS and other autoimmune diseases.publisher: Elsevier articletitle: Leukemia inhibitory factor tips the immune balance towards regulatory T cells in multiple sclerosis journaltitle: Brain, Behavior, and Immunity articlelink: http://dx.doi.org/10.1016/j.bbi.2014.11.010 content_type: article copyright: Copyright © 2014 Elsevier Inc. All rights reserved.status: publishe

Oncostatin M-induced astrocytic tissue inhibitor of metalloproteinases-1 drives remyelination

The brain's endogenous capacity to restore damaged myelin deteriorates during the course of demyelinating disorders. Currently, no treatment options are available to establish remyelination. Chronic demyelination leads to damaged axons and irreversible destruction of the central nervous system (CNS). We identified two promising therapeutic candidates which enhance remyelination: oncostatin M (OSM), a member of the interleukin-6 family, and downstream mediator tissue inhibitor of metalloproteinases-1 (TIMP-1). While remyelination was completely abrogated in OSMRβ knockout (KO) mice, OSM overexpression in the chronically demyelinated CNS established remyelination. Astrocytic TIMP-1 was demonstrated to play a pivotal role in OSM-mediated remyelination. Astrocyte-derived TIMP-1 drove differentiation of oligodendrocyte precursor cells into mature oligodendrocytes in vitro. In vivo, TIMP-1 deficiency completely abolished spontaneous remyelination, phenocopying OSMRβ KO mice. Finally, TIMP-1 was expressed by human astrocytes in demyelinated multiple sclerosis lesions, confirming the human value of our findings. Taken together, OSM and its downstream mediator TIMP-1 have the therapeutic potential to boost remyelination in demyelinating disorders

Oncostatin m-induced astrocytic tissue inhibitor of metalloproteinases-1 drives remyelination

The brain's endogenous capacity to restore damaged myelin deteriorates during the course of demyelinating disorders. Currently, no treatment options are available to establish remyelination. Chronic demyelination leads to damaged axons and irreversible destruction of the central nervous system (CNS). We identified two promising therapeutic candidates which enhance remyelination: oncostatin M (OSM), a member of the interleukin-6 family, and downstream mediator tissue inhibitor of metalloproteinases-1 (TIMP-1). While remyelination was completely abrogated in OSMRβ knockout (KO) mice, OSM overexpression in the chronically demyelinated CNS established remyelination. Astrocytic TIMP-1 was demonstrated to play a pivotal role in OSM-mediated remyelination. Astrocyte-derived TIMP-1 drove differentiation of oligodendrocyte precursor cells into mature oligodendrocytes in vitro. In vivo, TIMP-1 deficiency completely abolished spontaneous remyelination, phenocopying OSMRβ KO mice. Finally, TIMP-1 was expressed by human astrocytes in demyelinated multiple sclerosis lesions, confirming the human value of our findings. Taken together, OSM and its downstream mediator TIMP-1 have the therapeutic potential to boost remyelination in demyelinating disorders

Oncostatin m-induced astrocytic tissue inhibitor of metalloproteinases-1 drives remyelination

The brain's endogenous capacity to restore damaged myelin deteriorates during the course of demyelinating disorders. Currently, no treatment options are available to establish remyelination. Chronic demyelination leads to damaged axons and irreversible destruction of the central nervous system (CNS). We identified two promising therapeutic candidates which enhance remyelination: oncostatin M (OSM), a member of the interleukin-6 family, and downstream mediator tissue inhibitor of metalloproteinases-1 (TIMP-1). While remyelination was completely abrogated in OSMRβ knockout (KO) mice, OSM overexpression in the chronically demyelinated CNS established remyelination. Astrocytic TIMP-1 was demonstrated to play a pivotal role in OSM-mediated remyelination. Astrocyte-derived TIMP-1 drove differentiation of oligodendrocyte precursor cells into mature oligodendrocytes in vitro. In vivo, TIMP-1 deficiency completely abolished spontaneous remyelination, phenocopying OSMRβ KO mice. Finally, TIMP-1 was expressed by human astrocytes in demyelinated multiple sclerosis lesions, confirming the human value of our findings. Taken together, OSM and its downstream mediator TIMP-1 have the therapeutic potential to boost remyelination in demyelinating disorders

CNS-targeted LIF Expression Improves Therapeutic Efficacy and Limits Autoimmune-mediated Demyelination in a Model of Multiple Sclerosis

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) with an inflammatory and a neurodegenerative component. The neuropoietic cytokine leukemia inhibitory factor (LIF) is expressed in MS lesions, but its effect on lesion development is far from understood. LIF is an interesting candidate for MS therapy, as it has neuroprotective properties and may also promote the survival of myelinating oligodendrocytes (OLGs). However, therapeutic administration of LIF is complicated by its limited ability to cross the blood–brain barrier and its pleiotropic actions outside the CNS. In this study, lentiviral vectors (LVs) were used to achieve stable expression and secretion of LIF in the CNS of adult mice. CNS-targeted expression of LIF significantly reduced demyelination in a murine model of MS. In addition, local expression of LIF ameliorated clinical symptoms with enhanced efficacy compared to systemic treatment with recombinant protein. These findings demonstrate that gene therapeutic administration of LIF is a promising approach to limit lesion burden and clinical symptoms in neuroinflammatory disease