TY - JOUR A1 - Püschel, Gerhard A1 - Klauder, Julia A1 - Henkel-Oberländer, Janin T1 - Macrophages, low-grade inflammation, insulin resistance and hyperinsulinemia BT - A mutual ambiguous relationship in the development of metabolic diseases JF - Journal of Clinical Medicine : open access journal N2 - Metabolic derangement with poor glycemic control accompanying overweight and obesity is associated with chronic low-grade inflammation and hyperinsulinemia. Macrophages, which present a very heterogeneous population of cells, play a key role in the maintenance of normal tissue homeostasis, but functional alterations in the resident macrophage pool as well as newly recruited monocyte-derived macrophages are important drivers in the development of low-grade inflammation. While metabolic dysfunction, insulin resistance and tissue damage may trigger or advance pro-inflammatory responses in macrophages, the inflammation itself contributes to the development of insulin resistance and the resulting hyperinsulinemia. Macrophages express insulin receptors whose downstream signaling networks share a number of knots with the signaling pathways of pattern recognition and cytokine receptors, which shape macrophage polarity. The shared knots allow insulin to enhance or attenuate both pro-inflammatory and anti-inflammatory macrophage responses. This supposedly physiological function may be impaired by hyperinsulinemia or insulin resistance in macrophages. This review discusses the mutual ambiguous relationship of low-grade inflammation, insulin resistance, hyperinsulinemia and the insulin-dependent modulation of macrophage activity with a focus on adipose tissue and liver. KW - NAFLD/MAFLD KW - type 2 diabetes KW - obesity KW - vicious cycle KW - TLR signaling KW - M1/M2 differentiation KW - Akt pathway Y1 - 2022 U6 - https://doi.org/10.3390/jcm11154358 SN - 2077-0383 VL - 11 IS - 15 SP - 1 EP - 30 PB - MDPI CY - Basel, Schweiz ER - TY - JOUR A1 - Schjeide, Brit-Maren A1 - Schenke, Maren A1 - Seeger, Bettina A1 - Püschel, Gerhard T1 - Validation of a novel double control quantitative copy number PCR method to quantify off-target transgene integration after CRISPR-induced DNA modification JF - Methods and protocols : M&Ps N2 - In order to improve a recently established cell-based assay to assess the potency of botulinum neurotoxin, neuroblastoma-derived SiMa cells and induced pluripotent stem-cells (iPSC) were modified to incorporate the coding sequence of a reporter luciferase into a genetic safe harbor utilizing CRISPR/Cas9. A novel method, the double-control quantitative copy number PCR (dc-qcnPCR), was developed to detect off-target integrations of donor DNA. The donor DNA insertion success rate and targeted insertion success rate were analyzed in clones of each cell type. The dc-qcnPCR reliably quantified the copy number in both cell lines. The probability of incorrect donor DNA integration was significantly increased in SiMa cells in comparison to the iPSCs. This can possibly be explained by the lower bundled relative gene expression of a number of double-strand repair genes (BRCA1, DNA2, EXO1, MCPH1, MRE11, and RAD51) in SiMa clones than in iPSC clones. The dc-qcnPCR offers an efficient and cost-effective method to detect off-target CRISPR/Cas9-induced donor DNA integrations. KW - CRISPR editing validation KW - copy number analyses KW - homology-directed repair KW - homologous recombination deficiency Y1 - 2022 U6 - https://doi.org/10.3390/mps5030043 SN - 2409-9279 VL - 5 IS - 3 SP - 1 EP - 14 PB - MDPI CY - Basel, Schweiz ER - TY - JOUR A1 - Bishop, Christopher Allen A1 - Machate, Tina A1 - Henning, Thorsten A1 - Henkel-Oberländer, Janin A1 - Püschel, Gerhard A1 - Weber, Daniela A1 - Grune, Tilman A1 - Klaus, Susanne A1 - Weitkunat, Karolin T1 - Detrimental effects of branched-chain amino acids in glucose tolerance can be attributed to valine induced glucotoxicity in skeletal muscle JF - Nutrition & Diabetes N2 - Objective: Current data regarding the roles of branched-chain amino acids (BCAA) in metabolic health are rather conflicting, as positive and negative effects have been attributed to their intake. Methods: To address this, individual effects of leucine and valine were elucidated in vivo (C57BL/6JRj mice) with a detailed phenotyping of these supplementations in high-fat (HF) diets and further characterization with in vitro approaches (C2C12 myocytes). Results: Here, we demonstrate that under HF conditions, leucine mediates beneficial effects on adiposity and insulin sensitivity, in part due to increasing energy expenditure-likely contributing partially to the beneficial effects of a higher milk protein intake. On the other hand, valine feeding leads to a worsening of HF-induced health impairments, specifically reducing glucose tolerance/ insulin sensitivity. These negative effects are driven by an accumulation of the valine-derived metabolite 3-hydroxyisobutyrate (3HIB). Higher plasma 3-HIB levels increase basal skeletal muscle glucose uptake which drives glucotoxicity and impairs myocyte insulin signaling. Conclusion: These data demonstrate the detrimental role of valine in an HF context and elucidate additional targetable pathways in the etiology of BCAA-induced obesity and insulin resistance. Y1 - 2022 U6 - https://doi.org/10.1038/s41387-022-00200-8 SN - 2044-4052 VL - 12 IS - 1 PB - Nature Publishing Group CY - London ER - TY - JOUR A1 - Henkel-Oberländer, Janin A1 - Klauder, Julia A1 - Statz, Meike A1 - Wohlenberg, Anne-Sophie A1 - Kuipers, Sonja A1 - Vahrenbrink, Madita A1 - Püschel, Gerhard T1 - Enhanced Palmitate-Induced Interleukin-8 Formation in Human Macrophages by Insulin or Prostaglandin E₂ JF - Biomedicines : open access journal N2 - Macrophages in pathologically expanded dysfunctional white adipose tissue are exposed to a mix of potential modulators of inflammatory response, including fatty acids released from insulin-resistant adipocytes, increased levels of insulin produced to compensate insulin resistance, and prostaglandin E₂ (PGE₂) released from activated macrophages. The current study addressed the question of how palmitate might interact with insulin or PGE₂ to induce the formation of the chemotactic pro-inflammatory cytokine interleukin-8 (IL-8). Human THP-1 cells were differentiated into macrophages. In these macrophages, palmitate induced IL-8 formation. Insulin enhanced the induction of IL-8 formation by palmitate as well as the palmitate-dependent stimulation of PGE₂ synthesis. PGE₂ in turn elicited IL-8 formation on its own and enhanced the induction of IL-8 release by palmitate, most likely by activating the EP4 receptor. Since IL-8 causes insulin resistance and fosters inflammation, the increase in palmitate-induced IL-8 formation that is caused by hyperinsulinemia and locally produced PGE₂ in chronically inflamed adipose tissue might favor disease progression in a vicious feed-forward cycle. KW - macrophages KW - insulin KW - prostaglandin E2 KW - interleukin-8 KW - inflammation Y1 - 2021 U6 - https://doi.org/10.3390/biomedicines9050449 SN - 2227-9059 VL - 9 IS - 5 PB - MDPI CY - Basel ER - TY - CHAP A1 - Schenke, Maren A1 - Schjeide, Brit-Maren A1 - Püschel, Gerhard A1 - Seeger, Bettina T1 - Human motor neurons diffentiated from plutipotent stem cells as superior traged cells for botulinum neuotoxin potency testing BT - In: German Pharm-Tox Summit 2020: abstracts of the 86th Annual Meeting of the German Society for Experimental and Clinical Pharmacology and Toxicology (DGPT) T2 - Naunyn-Schmiedeberg's archives of pharmacology Y1 - 2020 U6 - https://doi.org/10.1007/s00210-020-01828-y SN - 0028-1298 SN - 1432-1912 VL - 393 IS - SUPPL 1 SP - 10 EP - 10 PB - Springer CY - Berlin ; Heidelberg ER -