Berberine Reduces Neurotoxicity Related to Nonalcoholic Steatohepatitis in Rats

Berberine is a plant alkaloid that has several pharmacological effects such as antioxidant, antilipidemic, and anti-inflammatory effects. Nonalcoholic steatohepatitis (NASH) triggers different aspects of disorders such as impaired endogenous lipid metabolism, hypercholesterolemia, oxidative stress, and neurotoxicity. In this study, we examined the mechanism by which NASH induces neurotoxicity and the protective effect of berberine against both NASH and its associated neurotoxicity. NASH induced rats showed significant impairments in lipid metabolism with increased serum triglycerides, cholesterol, and low-density lipoprotein (LDL). The NASH induced group also demonstrated a significant oxidative stress which is characterized by increased TBARs level and decreased antioxidant capacity such as GSH and SOD levels. Moreover, the NASH induction was associated with inflammation which was demonstrated by increased TNFα and nitric oxide levels. Hyperglycemia and hyperinsulinemia were observed in the NASH induced group. Also, our results showed a significant increase in the expression of the acetylcholine esterase (AChE) and amyloid beta precursor protein (AβPP). These changes were significantly correlated with decreased insulin degrading enzyme (IDE) and beta-amyloid40 (Aβ40) and increased beta-amyloid42 (Aβ42) in the hippocampal region. Daily administration of berberine (50 mg/kg) for three weeks ameliorated oxidative stress, inflammation, hyperlipidemia, hyperglycemia, hyperinsulinemia, and the observed neurotoxicity

IL-38 Ameliorates Skin Inflammation and Limits IL-17 Production from γδ T Cells

Summary: Interleukin-38 (IL-38) is a cytokine of the IL-1 family with a role in chronic inflammation. However, its main cellular targets and receptors remain obscure. IL-38 is highly expressed in the skin and downregulated in psoriasis patients. We report an investigation in cellular targets of IL-38 during the progression of imiquimod-induced psoriasis. In this model, IL-38 knockout (IL-38 KO) mice show delayed disease resolution with exacerbated IL-17-mediated inflammation, which is reversed by the administration of mature IL-38 or γδ T cell-receptor-blocking antibodies. Mechanistically, X-linked IL-1 receptor accessory protein-like 1 (IL1RAPL1) is upregulated upon γδ T cell activation to feedforward-amplify IL-17 production and is required for IL-38 to suppress γδ T cell IL-17 production. Accordingly, psoriatic IL1RAPL1 KO mice show reduced inflammation and IL-17 production by γδ T cells. Our findings indicate a role for IL-38 in the regulation of γδ T cell activation through IL1RAPL1, with consequences for auto-inflammatory disease. : Han et al. report that genetic depletion of IL-38 in mice delays the resolution of imiquimod-induced psoriasis by increasing the production of the inflammatory cytokine IL-17A by skin-infiltrating T cells. Depleting these T cells or the receptor that is targeted by IL-38 reduces psoriatic skin inflammation. Keywords: IL-38, IL1RAPL1, IL-17, γδ T cells, psoriasis, inflammatio

Role of mPGES-1-derived PGE2 in activation of breast cancer stromal fibroblasts

Cancer microenvironment is now recognized as a critical regulator of all stages of cancer development. Beside the tumor vasculature and tumor-infiltrating immune cells, other stromal cells such as cancer-associated fibroblasts (CAFs) regulate tumor growth. Fibroblasts are ubiquitous cells in connective tissue, where they shape the extracellular matrix (ECM). Fibroblasts are usually quiescent but get activated when tissue homeostasis is disturbed. Then, activated fibroblasts rebuild the ECM and communicate with local cells to participate in wound repair. These repair properties can go awry when being unchecked, which can lead to fibrosis and subsequently cancer development. CAFs can promote cancer development by fostering tumor cell growth, polarizing immune cells to an immunosuppressive phenotype, and crosslinking collagen to enable tumor cell invasion. Molecular mechanisms of CAF activation, thus, need to be understood to target these cells in tumors. Prostanoid prostaglandin E2 (PGE2) is viewed as a pro-tumor lipid mediator as suggested by studies pharmacologically or genetically targeting the enzymes producing PGE2, such as microsomal PGE synthase-1 (mPGES-1) in tumor models. Similar to CAFs, PGE2 drives tumor cell growth and tumor-associated immune suppression. Therefore, I hypothesized that PGE2 may play a role in CAF activation. This hypothesis was tested in two mouse models of breast cancer (orthotopic grafting model, and polyoma middle T oncogene transgenic model), besides using isolated mammary gland (MG) fibroblasts in vitro. As expected, given the pro-tumor function of PGE2, knocking out mPGES-1 reduced the growth of oncogene-driven and transplanted mammary tumors. Surprisingly, CAF density was markedly increased when mPGES-1 was depleted. Importantly, despite reduced primary tumor growth, I observed enhanced lung metastasis upon mPGES-1depletion. Using MG-derived fibroblasts in vitro furthermore revealed that treatment with PGE2 reduced a TGFβtriggered CAF-like activation state. Importantly, bioinformatics analysis of a human breast cancer patient dataset revealed a negative correlation of a PGE2 production signature with fibroblast marker genes. In a next step I investigated if the increased CAF infiltrate was connected to the reduced tumor growth upon depletion of PGE2. To unravel this, I first asked through which E prostanoid (EP) receptor PGE2 signals in fibroblasts. MG fibroblasts mainly expressed EP3, and EP3 KO fibroblasts showed a hyper-proliferative and activated phenotype, indicating EP3 as the main PGE2 receptor in MG fibroblasts. Co-injecting of EP3 KO MG fibroblasts and tumor cells in WT mice suppressed tumor growth, whereas co-injection of WT fibroblasts with tumor cell in mPGES-1 KO mice increased tumor growth. These data indicate that PGE2 restricts CAF levels through EP3, which supports tumor growth. Whole transcriptome mRNAsequencing of WT and mPGES-1 KO FACS-sorted CAFs combined with immunohistochemical data suggested a role of p38 mitogen-activated protein kinase (MAPK) in the modulation of fibroblast activation by PGE2. In summary, I showed in two breast cancer models that mPGES-1 depletion delays breast cancer progression, which is probably driven by the EP3-PGE2 signaling axis in host stroma. PGE2 appears to be a potent anti-fibroblast activation agent in tumors via EP3 and downstream p38 MAPK signaling. This study therefore hits the dogmatic perception of the general pro-tumor nature of PGE2; showing that PGE2 might be a double-edged mediator that can promote tumor growth at the primary site by restricting CAF expansion, which may in turn hinder infiltration of tumor cells to a secondary site.Die Tumormikroumgebung ist als ein kritischer Regulator aller Stadien der Tumor-‎entwicklung anerkannt. Neben dem Tumorendothelium und Tumor-infiltrierenden ‎Immunzellen sind auch andere Zellen des Tumorstromas wie Tumor-assoziierte ‎Fibroblasten (CAFs) an der Regulation des Tumorwachstums beteiligt. Fibroblasten sind ‎ubiquitäre Zellen des Bindegewebes, die gewöhnlich inaktivsind, Sie werden jedoch ‎durch Störungen der Gewebshomöostase aktiviert. In einem solchen Fall reparieren ‎aktivierte Fibroblasten die extrazelluläre Matrix (ECM) und kommunizieren mit lokalen ‎Zellen zum Zweck der Wundheilung. Diese Reparatureigenschaften können aus dem ‎Ruder laufen, wenn sie unreguliert verlaufen, was zur Organfibrose und nachfolgend ‎zur Tumorentwicklung führen kann, CAFs können die Tumorentwicklung durch ‎Induktion des Tumorwachstums, die Polarisierung von Immunzellen zu einem ‎immunsuppressiven Phänotyp, und durch die Vernetzung von Kollagen zur ‎Tumorzellinvasion fördern. Die CAF-Aktivierung muss folglich verstanden werden, um ‎diese Zellen als therapeutische Ziele zu nutzen. Das Prostanoid Prostaglandin E2 ‎‎(PGE2) wird als ein tumorfördernder Lipidmediator angesehen, was durch Studien ‎unterstützt wird, in denen PGE2-produzierende Enzyme wie die mikrosomale PGE ‎Synthase-1 (mPGES-1) genetisch oder pharmakologisch ausgeschaltet wurde. Ähnlich ‎wie CAFs fördert PGE2 das Tumorzellwachstum und die Tumor-Immunsuppression. ‎Daher stellte ich die Hypothese auf, dass PGE2 eine Rolle bei der CAF-Aktivierung ‎spielt. ‎ Die Hypothese testete ich in zwei Mammakarzinommodellen und unter Verwendung von ‎Fibroblasten aus den Brustdrüse (MGF) in vitro. Wie erwartet reduzierte ein Knockout ‎der mPGES-1 das Wachstum von Mammakarzinomen in beiden Tumormodellen, ‎erhöhte jedoch überraschenderweise die CAF-Dichte. Trotz des reduzierten ‎Wachstums des Primärtumors war jedoch die Metastasierung in die Lunge verstärkt. ‎Unter Verwendung von MGF in vitro konnte ich zeigen, dass PGE2 die TGF-β-induzierte ‎CAF-Aktivierung hemmte. Die bioinformatische Analyse humaner Mammakarzinom-‎Datensätze offenbarte darüber hinaus, dass eine Signatur der PGE2 Produktion negativ ‎mit Fibroblastenmarkern korrelierte. In einem nächsten Schritt untersuchte ich, ob das ‎vermehrte CAF Infiltrat ursächlich mit dem reduzierten Tumorwachstum verbunden war. ‎Zunächst stellt ich die Frage welchen E Prostanoid (EP) Rezeptor PGE2 in MGF ‎aktivierte. MGF exprimieren v.a. EP3 und EP3 KO MGF zeigten einen ‎hyperproliferativen, aktivierten Phänotyp, was auf EP3 als wichtigsten PGE2 Rezeptor in ‎MGF hindeutete. Ko-Injektion von EP3 KO MGF und Tumorzellen in WT Mäuse ‎hemmte das Tumorwachstum, wohingegen die Ko-Injektion von WT MGF mit ‎Tumorzellen in mPGES-1 KO Mäuse dieses erhöhte. Diese Daten legen nahe, dass ‎PGE2 die CAF-Anzahl durch EP3 einschränkt, was das Tumorwachstum fördert. ‎Transkriptomanalysen von FACS-isolierten WT und mPGES-1 KO CAFs kombiniert mit ‎immunhistochemischen Analysen zeigten eine Rolle der p38 mitogen-activated protein ‎kinase (MAPK) bei der Fibroblastenaktivierung durch PGE2 an.‎ Zusammenfassend zeigte ich in zwei Mammakarzinommodellen dass die mPGES-1 ‎Depletion die Tumorentwicklung durch die Beeinflussung von PGE2-EP3-Signalen im ‎Stroma hemmt. PGE2 stellt sich somit als potenter Hemmstoff der ‎Fibroblastenaktivierung in Tumoren via EP3/p38 MAPK-Signalen dar. Meine Daten ‎fordern somit die aktuelle Sichtweise auf PGE2 als ein tumorförderndes Agens heraus, ‎da PGE2 zwar das Wachstum des Primärtumors durch Hemmung der CAF-Expansion ‎förderte, jedoch die Metastasierung hemmt‎e

Breast cancer CAFs: spectrum of phenotypes and promising targeting avenues

Activation of the tumor-associated stroma to support tumor growth is a common feature observed in different cancer entities. This principle is exemplified by cancer-associated fibroblasts (CAFs), which are educated by the tumor to shape its development across all stages. CAFs can alter the extracellular matrix (ECM) and secrete a variety of different molecules. In that manner they have the capability to affect activation, survival, proliferation, and migration of other stromal cells and cancer cell themselves. Alteration of the ECM, desmoplasia, is a common feature of breast cancer, indicating a prominent role for CAFs in shaping tumor development in the mammary gland. In this review, we summarize the multiple roles CAFs play in mammary carcinoma. We discuss experimental and clinical strategies to interfere with CAFs function in breast cancer. Moreover, we highlight the issues arising from CAFs heterogeneity and the need for further research to identify CAFs subpopulation(s) that can be targeted to improve breast cancer therapy

Iron-bound lipocalin-2 from tumor-associated macrophages drives breast cancer progression independent of ferroportin

Macrophages supply iron to the breast tumor microenvironment by enforced secretion of lipocalin-2 (Lcn-2)-bound iron as well as the increased expression of the iron exporter ferroportin (FPN). We aimed at identifying the contribution of each pathway in supplying iron for the growing tumor, thereby fostering tumor progression. Analyzing the expression profiles of Lcn-2 and FPN using the spontaneous polyoma-middle-T oncogene (PyMT) breast cancer model as well as mining publicly available TCGA (The Cancer Genome Atlas) and GEO Series(GSE) datasets from the Gene Expression Omnibus database (GEO), we found no association between tumor parameters and Lcn-2 or FPN. However, stromal/macrophage-expression of Lcn-2 correlated with tumor onset, lung metastases, and recurrence, whereas FPN did not. While the total iron amount in wildtype and Lcn-2−/− PyMT tumors showed no difference, we observed that tumor-associated macrophages from Lcn-2−/− compared to wildtype tumors stored more iron. In contrast, Lcn-2−/− tumor cells accumulated less iron than their wildtype counterparts, translating into a low migratory and proliferative capacity of Lcn-2−/− tumor cells in a 3D tumor spheroid model in vitro. Our data suggest a pivotal role of Lcn-2 in tumor iron-management, affecting tumor growth. This study underscores the role of iron for tumor progression and the need for a better understanding of iron-targeted therapy approaches

Phenotypic plasticity of fibroblasts during mammary carcinoma development

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment contribute to all stages of tumorigenesis and are usually considered to be tumor-promoting cells. CAFs show a remarkable degree of heterogeneity, which is attributed to developmental origin or to local environmental niches, resulting in distinct CAF subsets within individual tumors. While CAF heterogeneity is frequently investigated in late-stage tumors, data on longitudinal CAF development in tumors are lacking. To this end, we used the transgenic polyoma middle T oncogene-induced mouse mammary carcinoma model and performed whole transcriptome analysis in FACS-sorted fibroblasts from early- and late-stage tumors. We observed a shift in fibroblast populations over time towards a subset previously shown to negatively correlate with patient survival, which was confirmed by multispectral immunofluorescence analysis. Moreover, we identified a transcriptomic signature distinguishing CAFs from early- and late-stage tumors. Importantly, the signature of early-stage CAFs correlated well with tumor stage and survival in human mammary carcinoma patients. A random forest analysis suggested predictive value of the complete set of differentially expressed genes between early- and late-stage CAFs on bulk tumor patient samples, supporting the clinical relevance of our findings. In conclusion, our data show transcriptome alterations in CAFs during tumorigenesis in the mammary gland, which suggest that CAFs are educated by the tumor over time to promote tumor development. Moreover, we show that murine CAF gene signatures can harbor predictive value for human cancer

Berberine Reduces Neurotoxicity Related to Nonalcoholic Steatohepatitis in Rats

Berberine is a plant alkaloid that has several pharmacological effects such as antioxidant, antilipidemic, and anti-inflammatory effects. Nonalcoholic steatohepatitis (NASH) triggers different aspects of disorders such as impaired endogenous lipid metabolism, hypercholesterolemia, oxidative stress, and neurotoxicity. In this study, we examined the mechanism by which NASH induces neurotoxicity and the protective effect of berberine against both NASH and its associated neurotoxicity. NASH induced rats showed significant impairments in lipid metabolism with increased serum triglycerides, cholesterol, and low-density lipoprotein (LDL). The NASH induced group also demonstrated a significant oxidative stress which is characterized by increased TBARs level and decreased antioxidant capacity such as GSH and SOD levels. Moreover, the NASH induction was associated with inflammation which was demonstrated by increased TNFα and nitric oxide levels. Hyperglycemia and hyperinsulinemia were observed in the NASH induced group. Also, our results showed a significant increase in the expression of the acetylcholine esterase (AChE) and amyloid beta precursor protein (AβPP). These changes were significantly correlated with decreased insulin degrading enzyme (IDE) and beta-amyloid40 (Aβ40) and increased beta-amyloid42 (Aβ42) in the hippocampal region. Daily administration of berberine (50 mg/kg) for three weeks ameliorated oxidative stress, inflammation, hyperlipidemia, hyperglycemia, hyperinsulinemia, and the observed neurotoxicity