Biology subjects

Ebersbach, H.

Publications and source records attributed to Ebersbach, H..

3 recordsLinked to original sources

bioRxiv2023

Reversible expansion of tissue macrophages in response to macrophage colony-stimulating factor (CSF1) transforms systemic metabolism to fuel growth.

Background and AimMacrophages regulate metabolic homeostasis in health and disease. Macrophage colony-stimulating factor (CSF1)-dependent macrophages contribute to homeostatic control of the size of the liver. This study aimed to determine the systemic metabolic consequences of elevating circulating CSF1. Methods and ResultsAcute administration of a CSF1-Fc fusion protein led to monocytosis, increased resident tissue macrophages in the liver and all major organs, and liver growth. These effects were associated with increased hepatic glucose uptake and extensive mobilisation of body fat. The impacts of CSF1 on macrophage abundance, liver size and body composition were rapidly reversed to restore homeostasis. CSF1s effects on metabolism were independent of several known endocrine regulators and did not impact the physiological fasting response. Analysis using implantable telemetry in metabolic cages revealed progressively reduced body temperature and physical activity with no change in diurnal food intake. ConclusionThese results demonstrate the existence of a dynamic equilibrium between CSF1, the mononuclear phagocyte system, metabolic regulation and homeostatic control of liver:body weight ratio.

immunology↗

bioRxiv2021

Therapeutic potential of macrophage colony-stimulating factor (CSF1) in chronic liver disease

Resident and recruited macrophages control the development and proliferation of the liver. We showed previously in multiple species that treatment with a macrophage colony stimulating factor (CSF1)-Fc fusion protein initiated hepatocyte proliferation and promoted repair in models of acute hepatic injury in mice. Here we investigated the impact of CSF1-Fc on resolution of advanced fibrosis and liver regeneration, utilizing a non-resolving toxin-induced model of chronic liver injury and fibrosis in C57BL/6J mice. Co-administration of CSF1-Fc with exposure to thioacetamide (TAA) exacerbated inflammation consistent with monocyte contributions to initiation of pathology. After removal of TAA, either acute or chronic CSF1-Fc treatment promoted liver growth, prevented progression and promoted resolution of fibrosis. Acute CSF1-Fc treatment was also anti-fibrotic and pro-regenerative in a model of partial hepatectomy in mice with established fibrosis. The beneficial impacts of CSF1-Fc treatment were associated with monocyte-macrophage recruitment and increased expression of remodeling enzymes and growth factors. These studies indicate that CSF1-dependent macrophages contribute to both initiation and resolution of fibrotic injury and that CSF1-Fc has therapeutic potential in human liver disease. Summary statementMacrophages contribute to both progression and resolution of chronic tissue injury and fibrogenesis. Administration of a macrophage growth factor promoted liver regeneration and resolution of advanced liver fibrosis in mice.

immunology↗

bioRxiv2020

ADA2 is a lysosomal DNase regulating the type-I interferon response

Deficiency of adenosine deaminase 2 (DADA2) is a severe, congenital syndrome, which manifests with hematologic, immunologic and inflammatory pathologies. DADA2 is caused by biallelic mutations in ADA2, but the function of ADA2, and the mechanistic link between ADA2 deficiency and the severe inflammatory phenotype remains unclear. Here, we show that monocyte-derived proteomes from DADA2 patients are highly enriched in interferon response proteins. Using immunohistochemistry and detailed glycan analysis we demonstrate that ADA2 is post-translationally modified for sorting to the lysosomes. At acidic, lysosomal pH, ADA2 acts as a novel DNase that degrades cGAS/Sting-activating ligands. Furthermore, we define a clear structure-function relationship for this acidic DNase activity. Deletion of ADA2 increased the production of cGAMP and type I interferons upon exposure to dsDNA, which was reverted by ADA2 overexpression or deletion of STING. Our results identify a new level of control in the nucleic acid sensing machinery and provide a mechanistic explanation for the pathophysiology of autoinflammation in DADA2. One Sentence SummaryADA2 is a lysosomal nuclease controlling nucleic acid sensing and type I interferon production.

immunology↗