scholarly journals Alpha Interferon Induces Long-Lasting Refractoriness of JAK-STAT Signaling in the Mouse Liver through Induction of USP18/UBP43

2009 ◽  
Vol 29 (17) ◽  
pp. 4841-4851 ◽  
Author(s):  
Magdalena Sarasin-Filipowicz ◽  
Xueya Wang ◽  
Ming Yan ◽  
Francois H. T. Duong ◽  
Valeria Poli ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Therapeutic Potential ◽  
Negative Regulator ◽  
Alpha Interferon ◽  
Serum Concentrations ◽  
Intrinsic Properties ◽  
Once Daily ◽  
Therapeutic Practice ◽  
Long Acting

ABSTRACT Recombinant alpha interferon (IFN-α) is used for the treatment of viral hepatitis and some forms of cancer. During these therapies IFN-α is injected once daily or every second day for several months. Recently, the long-acting pegylated IFN-α (pegIFN-α) has replaced standard IFN-α in therapies of chronic hepatitis C because it is more effective, supposedly by inducing a long-lasting activation of IFN signaling pathways. IFN signaling in cultured cells, however, becomes refractory within hours, and little is known about the pharmacodynamic effects of continuously high IFN-α serum concentrations. To investigate the behavior of the IFN system in vivo, we repeatedly injected mice with IFN-α and analyzed its effects in the liver. Within hours after the first injection, IFN-α signaling became refractory to further stimulation. The negative regulator SOCS1 was rapidly upregulated and likely responsible for early termination of IFN-α signaling. For long-lasting refractoriness, neither SOCS1 nor SOCS3 were instrumental. Instead, we identified the inhibitor USP18/UBP43 as the key mediator. Our results indicate that the current therapeutic practice using long-lasting pegIFN-α is not well adapted to the intrinsic properties of the IFN system. Targeting USP18 expression may allow to exploit the full therapeutic potential of recombinant IFN-α.

scholarly journals In Vivo Activity and Pharmacokinetics of Ziracin (SCH27899), a New Long-Acting Everninomicin Antibiotic, in a Murine Model of Penicillin-Susceptible or Penicillin-Resistant Pneumococcal Pneumonia

2000 ◽  
Vol 44 (4) ◽  
pp. 1010-1018 ◽  
Author(s):  
Erjian Wang ◽  
Marie Simard ◽  
Yves Bergeron ◽  
Denis Beauchamp ◽  
Michel G. Bergeron
Keyword(s):  
Survival Rate ◽  
Half Life ◽  
Survival Rates ◽  
High Survival ◽  
Once Daily ◽  
Concentration Time ◽  
Pharmacokinetic Properties ◽  
Long Acting ◽  
Immunocompetent Mice

ABSTRACT The effectiveness of ziracin (SCH27899), a novel everninomicin, was at first investigated against lethal pneumonia caused by a penicillin-susceptible Streptococcus pneumoniae strain. A single intravenous injection of ziracin at a dose of 60 mg/kg of body weight given at 18 h postinfection protected 100% mice and led to the complete clearance of bacteria from their lungs. The activity of ziracin was observed to be the same as that of ceftriaxone: the 50% protective doses (PD50s) of ziracin and ceftriaxone were 24.8 and 24.6 mg/kg, respectively. Evaluation of this therapy with leukopenic mice showed that a single injection of ziracin protected 75% of these mice. A delay in therapy with ziracin, which was initiated at 48 h postinfection with 30 mg/kg given once daily for 3 days, resulted in an 83% survival rate of immunocompetent mice. The efficacy of ziracin was further compared to that of vancomycin against lethal pneumonia caused by a penicillin-resistant S. pneumoniae strain in leukopenic mice. The PD50s of ziracin and vancomycin were 40.5 and 44.2 mg/kg, respectively. Treatment with ziracin at 30 mg/kg once daily for 2 days (initiated 18 h postinfection) yielded an 83% survival rate and achieved complete eradication of the bacteria. The results were the same as those obtained with vancomycin administered at 15 mg/kg twice daily for 2 days. It is notable that the high survival rates for mice treated with ziracin were associated with effective eradication of the bacteria and rapid recovery of pulmonary tissues from pneumonia. The pharmacokinetic properties of ziracin, ceftriaxone, and vancomycin were estimated following intravenous administration of a single dose of 30 mg/kg to immunocompetent mice. The half-life of ziracin was observed to be longer than those of ceftriaxone and vancomycin (2.3 h versus 1.0 and 0.36 h in the bloodstream and 3 h versus 1.9 and 0.45 h in lung tissues). The areas under the concentration-time curves (AUCs) in lung tissue for ziracin versus those for ceftriaxone and vancomycin were 36 μg · h/g versus 20 and 9.5 μg · h/g. The prolonged half-life and high AUC for ziracin in tissue contributed to its excellent in vivo activities.

scholarly journals Gallic Acid Attenuates Dimethylnitrosamine-Induced Liver Fibrosis by Alteration of Smad Phosphoisoform Signaling in Rats

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Yuxin Chen ◽  
Ziping Zhou ◽  
Qigui Mo ◽  
Gao Zhou ◽  
Youwei Wang
Keyword(s):  
Liver Fibrosis ◽  
Gallic Acid ◽  
Liver Damage ◽  
Therapeutic Potential ◽  
Control Group ◽  
Once Daily ◽  
Serum Parameters ◽  
Natural Medicine ◽  
Liver And Kidney

Dimethylnitrosamine (DMN) is a potent hepatotoxin, carcinogen, and mutagen. In our previous study, a candidate gallic acid (GA) that widely exists in food and fruit was selected for its capability to alleviate DMN toxicity in vivo. We aimed to investigate the therapeutic potential of GA against DMN-induced liver fibrosis. During the first four weeks, DMN was administered to rats via intraperitoneal injection every other day, except the control group. GA or silymarin was given to rats by gavage once daily from the second to the sixth week. GA significantly reduced liver damage in serum parameters and improved the antioxidant capacity in liver and kidney tissues. Cytokines involved in liver fibrosis were measured at transcriptional and translational levels. These results indicate that GA exhibits robust antioxidant and antifibrosis effects and may be an effective candidate natural medicine for liver fibrosis treatment.

Vitamin D3 Modulates Definitive Hematopoiesis by Two Distinct Mechanisms in the Developing Zebrafish Embryo

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 763-763
Author(s):  
Mauricio Cortes ◽  
Kelsey Natsuhara ◽  
Wolfram Goessling ◽  
Trista E. North
Keyword(s):  
Vitamin D3 ◽  
Hedgehog Signaling ◽  
Hematological Malignancies ◽  
Therapeutic Potential ◽  
Negative Regulator ◽  
Facs Analysis ◽  
Double Positive ◽  
Definitive Hematopoiesis

Abstract Abstract 763 Studies of the vitamin D3 signaling pathway have revealed a broad role for this hormone in tissue homeostasis and as a result there is great interest in exploring the therapeutic potential of vitamin D3 for the treatment of various diseases including cancer. Studies investigating the role of vitamin D3 in hematological malignancies have shown that in vitro vitamin D3 has anti-proliferative and pro-differentiation effects resulting in differentiation of leukemic cell lines towards the monocytic lineage. Surprisingly, the role of vitamin D3 in HSC homeostasis and leukemia progression in vivo is not well understood. To elucidate the mechanisms of action of vitamin D3 in vivo during HSC self-renewal and differentiation, we utilized the zebrafish (Danio rerio) as vertebrate model due to their evolutionary conserved blood system and their amenability for genetic and chemical manipulation. Vitamin D3 was identified in a chemical screen performed in our laboratory as a regulator of runx1 and c-myb expression in the aorta-gonad mesonephros (AGM), the first site of definitive hematopoiesis. Treatments of zebrafish embryos with active vitamin D3 (1,25OH D3) between 12–36 hours post fertilization (hpf) resulted in increased expression of HSC markers (runx1, c-myb, CD41) as determined by whole mount in situ hybridization (WISH). In contrast, treatment with the non-hydroxylated vitamin D3 precursor cholecalciferol (D3) resulted in decreased runx1 and c-myb expression. D3 treatment during HSC induction and expansion from 24–36 hpf did not affect runx1 and c-myb expression, suggesting that D3 is acting early during the establishment of the vascular niche. To quantify the difference in HSC progenitors observed by WISH, FACS analysis was performed on double positive Tg(Lmo2:dsRed), Tg(c-myb:gfp) embryos. 1,25OH D3 treated embryos had a 20% increase in the double positive cell population corresponding to HSCs, while treatment with D3 resulted in a 25% decrease in the number of HSCs. The differential effect of 1,25OH D3 and D3 suggest that these two compounds act via two distinct mechanisms. To determine if the HSC enhancement observed by 1,25OH D3 was acting through the canonical vitamin D3 receptor (VDR), loss of function experiments were performed by injecting morpholinos targeting the vitamin D receptors. Morpholino knockdown of VDRA and VDRB (zebrafish VDR orthologs) resulted in decreased expression of runx1 c-myb, and CD41 via WISH. The decrease in HSC positive cells was confirmed by fluorescence microscopy using the Tg(Runx1P2:gfp) and Tg(-6.0itga:gfp) reporter lines, further supporting our hypothesis. To address the decrease in HSCs by D3, we postulated that D3 was inhibiting hedgehog signaling, as vitamin D3 has been previously shown to act as a negative regulator of the hedgehog pathway. In support of our hypothesis, treatment with D3 resulted in decreased ptch2 mRNA expression a downstream target of hedgehog signaling. In addition, FACS analysis using the hedgehog reporter Tg(6xGli:mCherry) line showed a 15% reduction in the number of mCherry positive cells in D3 treated embryos compared to controls. Co-treatments of zebrafish embryos with the hedgehog antagonist cyclopamine and D3 resulted in additive loss of reporter activity (45%) and loss of runx1 positive cells in the AGM, revealing synergy between these two compounds. In addition, co-exposure with the hedgehog agonist SAG rescued the HSC defect in D3-treated embryos. Hedgehog signaling is known to regulate vein and artery specification through the activation of notch signaling. Consistent with our hypothesis that D3 reduces hedgehog signaling, an expansion of the venous marker flt4 and a reduction in the expression of the arterial marker ephrinb2a was observed by WISH on D3-treated embryos. Furthermore, treatment of the notch reporter line Tg(Notch:gfp) with D3 resulted in lowered notch activity. In summary, these studies reveal that the active 1,25OH D3 positively regulates HSC progenitors in vivo during the onset of definitive hematopoiesis. In contrast, the non-hydroxylated vitamin D3 precursor acts as negative regulator of hematopoiesis by inhibiting hedgehog signaling and affecting vascular niche formation. Based on our studies, the differential effect between D3 and 1,25OH D3 should be considered when investigating the therapeutic potential of vitamin D3 in the context of hematological malignancies and other cancers. Disclosures: Goessling: Fate Therapeutics: Consultancy. North:Fate Therapeutics: Consultancy.

Abstract P371: Fusion Of C-type Natriuretic Peptide With Elastin-like Polypeptide For Enhanced Pharmacological Activity

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
James D Jowett ◽  
Susan Arnold ◽  
Bret Umsted ◽  
Dave Sendecki ◽  
Dave Dickerhoff ◽  
...  
Keyword(s):  
Natriuretic Peptide ◽  
Slow Release ◽  
Therapeutic Potential ◽  
Pharmacokinetic Profile ◽  
Temperature Dependent ◽  
E Coli ◽  
Elimination Half ◽  
Long Acting

C-type natriuretic peptide (CNP) is a pluripotent molecule produced by the endothelium and myocardium with therapeutic potential in pulmonary hypertension, myocardial infarction, and heart failure. However, the native peptide’s short elimination half-life of under 3 minutes limits its use clinically. To improve the pharmacokinetic profile of CNP we recombinantly expressed the CNP peptide as a fusion with an elastin-like polypeptide (ELP). ELPs are biopolymers that undergo reversible temperature-dependent phase separation and form a subcutaneous depot upon injection. CNP-ELP fusion proteins were expressed in E. coli , purified, and showed in vitro potency 2-4 fold less than native CNP. When administered subcutaneously in mice CNP-ELP showed a significantly enhanced PK profile due to the slow release of the fusion into the circulation with detectable fusion protein 24 hours after a single injection. In addition, the CNP-ELP increased growth velocity in mice significantly greater than that of native peptide indicating an in vivo activation of the CNP receptor, NPR-B. These findings represent a new method of administering a long acting CNP peptide for treatment of different cardiovascular diseases.

scholarly journals Genetic Evidence for the Interactions of Cyclin D1 and p27Kip1 in Mice

2001 ◽  
Vol 21 (4) ◽  
pp. 1319-1328 ◽  
Author(s):  
Wei Tong ◽  
Jeffrey W. Pollard
Keyword(s):  
Cell Cycle ◽  
Body Weight ◽  
Cyclin D1 ◽  
Cultured Cells ◽  
Cyclin E ◽  
Negative Regulator ◽  
Luteal Cell ◽  
Null Mouse ◽  
Cdk2 Activity

ABSTRACT The cell cycle of cultured cells appears to be regulated by opposing actions of the cyclins together with their partners, the cyclin-dependent kinases (Cdk), and their inhibitors (Cki). Consistent with this situation null mutations in the genes for cyclin D1 and Cki p27Kip1 in mice give opposite phenotypes of dwarfism and gigantism. To test their genetic interactions, we generated mice nullizygous for both genes. Correction of cyclin D1 or p27 null to wild-type phenotypes was observed for many but not all traits. These included, for cyclin D1−/− mice, body weight, early lethality, retinal hypoplasia, and male aggressiveness and, for p27−/− mice, body weight, retinal hyperplasia, and embryo implantation. p27−/− traits that were not corrected were the aberrant estrus cycles, luteal cell proliferation, and susceptibility to pituitary tumors. This mutual correction of these phenotypes is the first genetic demonstration of the interaction of these inhibitory and stimulatory cell cycle-regulatory molecules in vivo. The molecular basis for the correction was analyzed in the neonatal retina. Retinal cellularity was rescued in the cyclin D1 null mouse by loss of p27 with only a partial restoration of phosphorylation of retinoblastoma protein (Rb) and Cdk4 activity but with a dramatic elevation of Cdk2 activity. Our data provide in vivo genetic validation of cell culture experiments that indicated that p27 acts as a negative regulator of cyclin E-Cdk2 activity and that it can be titrated away by cyclin D-Cdk4 complexes. It also supports the suggestion that the cyclin E/Cdk2 pathway can largely bypass Rb in regulating the cell cycle in vivo.

scholarly journals Peripheral Disruption of the Grb10 Gene Enhances Insulin Signaling and Sensitivity In Vivo

2007 ◽  
Vol 27 (18) ◽  
pp. 6497-6505 ◽  
Author(s):  
Lixin Wang ◽  
Bogdan Balas ◽  
Christine Y. Christ-Roberts ◽  
Ryang Yeo Kim ◽  
Fresnida J. Ramos ◽  
...  
Keyword(s):  
Gene Expression ◽  
Insulin Receptor ◽  
Insulin Signaling ◽  
Tyrosine Kinases ◽  
Cultured Cells ◽  
Adaptor Protein ◽  
Negative Regulator ◽  
Mitogen Activated Protein Kinase ◽  
Peripheral Tissues

ABSTRACT Grb10 is a pleckstrin homology and Src homology 2 domain-containing protein that interacts with a number of phosphorylated receptor tyrosine kinases, including the insulin receptor. In mice, Grb10 gene expression is imprinted with maternal expression in all tissues except the brain. While the interaction between Grb10 and the insulin receptor has been extensively investigated in cultured cells, whether this adaptor protein plays a positive or negative role in insulin signaling and action remains controversial. In order to investigate the in vivo role of Grb10 in insulin signaling and action in the periphery, we generated Grb10 knockout mice by the gene trap technique and analyzed mice with maternal inheritance of the knockout allele. Disruption of Grb10 gene expression in peripheral tissues had no significant effect on fasting glucose and insulin levels. On the other hand, peripheral-tissue-specific knockout of Grb10 led to significant overgrowth of the mice, consistent with a role for endogenous Grb10 as a growth suppressor. Loss of Grb10 expression in insulin target tissues, such as skeletal muscle and fat, resulted in enhanced insulin-stimulated Akt and mitogen-activated protein kinase phosphorylation. Hyperinsulinemic-euglycemic clamp studies revealed that disruption of Grb10 gene expression in peripheral tissues led to increased insulin sensitivity. Taken together, our results provide strong evidence that Grb10 is a negative regulator of insulin signaling and action in vivo.

scholarly journals miRNA-34c suppresses osteosarcoma progression in vivo by targeting Notch and E2F

2021 ◽  
Author(s):  
Yangjin Bae ◽  
Huan-Chang Zeng ◽  
Yi-Ting Chen ◽  
Shamika Ketkar ◽  
Elda Munivez ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Therapeutic Potential ◽  
Xenograft Model ◽  
Tumor Burden ◽  
Negative Regulator ◽  
In Vitro Assays ◽  
Over Expression ◽  
Orthotopic Xenograft Model

The expression of microRNAs (miRNAs) is dysregulated in many types of cancers including osteosarcoma (OS) due to genetic and epigenetic alterations. Among these, miR-34c, an effector of tumor suppressor P53 and an upstream negative regulator of Notch signaling in osteoblast differentiation, is dysregulated in OS. Here, we demonstrated a tumor suppressive role of miR-34c in OS progression using in vitro assays and in vivo genetic mouse models. We found that miR-34c inhibits the proliferation and the invasion of metastatic OS cells, which resulted in reduction of the tumor burden and increased overall survival in an orthotopic xenograft model. Moreover, the osteoblast specific over expression of miR-34c increased survival in the osteoblast specific p53 mutant OS mouse model. We found that miR-34c regulates the transcription of several genes in Notch signaling (NOTCH1, JAG1 and HEY2) and in p53 mediated cell cycle and apoptosis (CCNE2, E2F5, E2F2 and HDAC1). More interestingly, we found that the metastatic free survival probability was increased among a patient cohort from TARGET OS which has lower expression of direct targets of miR-34c that was identified in our transcriptome analysis such as E2F5 and NOTCH1. In conclusion, we demonstrate that miR-34c is a tumor suppressive miRNA in OS progression in vivo. In addition, we highlight the therapeutic potential of targeting miR-34c in OS.

scholarly journals Myeloid-Derived Suppressive Cells Deficient in Liver X Receptor α Protected From Autoimmune Hepatitis

2021 ◽  
Vol 12 ◽  
Author(s):  
Bo Li ◽  
Min Lian ◽  
Yikang Li ◽  
Qiwei Qian ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Autoimmune Hepatitis ◽  
Transcriptional Activation ◽  
Therapeutic Potential ◽  
Suppressor Cells ◽  
Adoptive Cell Transfer ◽  
Negative Regulator ◽  
Liver X Receptor Α ◽  
X Receptors

Myeloid-derived suppressor cells (MDSCs) emerge as a promising candidate for the immunotherapy of autoimmune hepatitis (AIH). However, targets for modulating MDSC in AIH are still being searched. Liver X receptors (LXRs) are important nuclear receptors linking lipid metabolism and immune responses. Despite the extensive studies of LXR in myeloid compartment, its role in MDSCs is currently less understood. Herein, expression of LXRα was found to be upregulated in AIH patients and colocalized with hepatic MDSCs. In ConA-induced hepatitis, deletion of LXRα led to increased expansion of MDSCs in the liver and alleviated the hepatic injury. MDSCs in LXRα−/− mice exhibited enhanced proliferation and survival comparing with WT mice. T-cell proliferation assay and adoptive cell transfer experiment validated the potent immunoregulatory role of MDSCs in vitro and in vivo. Mechanistically, MDSCs from LXRα−/− mice possessed significantly lower expression of interferon regulatory factor 8 (IRF-8), a key negative regulator of MDSC differentiation. Transcriptional activation of IRF-8 by LXRα was further demonstratedConclusionWe reported that abrogation of LXRα facilitated the expansion of MDSCs via downregulating IRF-8, and thereby ameliorated hepatic immune injury profoundly. Our work highlights the therapeutic potential of targeting LXRα in AIH.

scholarly journals Lysosomal-Associated Protein Transmembrane 5 Functions as a Novel Negative Regulator of Pathological Cardiac Hypertrophy

2021 ◽  
Vol 8 ◽  
Author(s):  
Lu Gao ◽  
Sen Guo ◽  
Rui Long ◽  
Lili Xiao ◽  
Rui Yao ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Ventricular Myocytes ◽  
Therapeutic Potential ◽  
Negative Regulator ◽  
Neonatal Rat ◽  
Cardiomyocyte Hypertrophy ◽  
Pathological Cardiac Hypertrophy

Lysosomal-associated protein transmembrane 5 (LAPTM5) is mainly expressed in immune cells and has been reported to regulate inflammation, apoptosis and autophagy. Although LAPTM5 is expressed in the heart, whether LAPTM5 plays a role in regulating cardiac function remains unknown. Here, we show that the expression of LAPTM5 is dramatically decreased in murine hypertrophic hearts and isolated hypertrophic cardiomyocytes. In this study, we investigated the role of LAPTM5 in pathological cardiac hypertrophy and its possible mechanism. Our results show that LAPTM5 gene deletion significantly exacerbates cardiac remodeling, which can be demonstrated by reduced myocardial hypertrophy, fibrosis, ventricular dilation and preserved ejection function, whereas the opposite phenotype was observed in LAPTM5 overexpression mice. In line with the in vivo results, knockdown of LAPTM5 exaggerated angiotensin II-induced cardiomyocyte hypertrophy in neonatal rat ventricular myocytes, whereas overexpression of LAPTM5 protected against angiotensin II-induced cardiomyocyte hypertrophy in vitro. Mechanistically, LAPTM5 directly bound to Rac1 and further inhibited MEK-ERK1/2 signaling, which ultimately regulated the development of cardiac hypertrophy. In addition, the antihypertrophic effect of LAPTM5 was largely blocked by constitutively active mutant Rac1 (G12V). In conclusion, our results suggest that LAPTM5 is involved in pathological cardiac hypertrophy and that targeting LAPTM5 has great therapeutic potential in the treatment of pathological cardiac hypertrophy.

scholarly journals p53 dynamics vary between tissues and are linked with radiation sensitivity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jacob Stewart-Ornstein ◽  
Yoshiko Iwamoto ◽  
Miles A. Miller ◽  
Mark A. Prytyskach ◽  
Stephane Ferretti ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Temporal Dynamics ◽  
P53 Protein ◽  
Radiation Sensitivity ◽  
Negative Regulator ◽  
Normal Tissues ◽  
P53 Signaling ◽  
P53 Activation ◽  
Transcription Factor P53

AbstractRadiation sensitivity varies greatly between tissues. The transcription factor p53 mediates the response to radiation; however, the abundance of p53 protein does not correlate well with the extent of radiosensitivity across tissues. Given recent studies showing that the temporal dynamics of p53 influence the fate of cultured cells in response to irradiation, we set out to determine the dynamic behavior of p53 and its impact on radiation sensitivity in vivo. We find that radiosensitive tissues show prolonged p53 signaling after radiation, while more resistant tissues show transient p53 activation. Sustaining p53 using a small molecule (NMI801) that inhibits Mdm2, a negative regulator of p53, reduced viability in cell culture and suppressed tumor growth. Our work proposes a mechanism for the control of radiation sensitivity and suggests tools to alter the dynamics of p53 to enhance tumor clearance. Similar approaches can be used to enhance killing of cancer cells or reduce toxicity in normal tissues following genotoxic therapies.

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