ABSTRACT
Fibroblast growth factor 23 (FGF23), a hormone generally derived from bone, is important in phosphate and vitamin D homeostasis. In acute kidney injury (AKI) patients, high-circulating FGF23 levels are associated with disease progression and mortality. However, the organ and cell type of FGF23 production in AKI and the molecular mechanism of its excessive production are still unidentified. For insight, we investigated folic acid (FA)-induced AKI in mice. Interestingly, simultaneous with FGF23, orphan nuclear receptor ERR-γ expression is increased in the liver of FA-treated mice, and ectopic overexpression of ERR-γ was sufficient to induce hepatic FGF23 production. In patients and in mice, AKI is accompanied by up-regulated systemic IL-6, which was previously identified as an upstream regulator of ERR-γ expression in the liver. Administration of IL-6 neutralizing antibody to FA-treated mice or of recombinant IL-6 to healthy mice confirms IL-6 as an upstream regulator of hepatic ERR-γ-mediated FGF23 production. A significant (P < 0.001) interconnection between high IL-6 and FGF23 levels as a predictor of AKI in patients that underwent cardiac surgery was also found, suggesting the clinical relevance of the finding. Finally, liver-specific depletion of ERR-γ or treatment with an inverse ERR-γ agonist decreased hepatic FGF23 expression and plasma FGF23 levels in mice with FA-induced AKI. Thus, inverse agonist of ERR-γ may represent a therapeutic strategy to reduce adverse plasma FGF23 levels in AKI.
Subject(s)
Acute Kidney Injury/physiopathology , Fibroblast Growth Factor-23/metabolism , Receptors, Estrogen/metabolism , Acute Kidney Injury/metabolism , Animals , Disease Models, Animal , Fibroblast Growth Factor-23/genetics , Folic Acid/adverse effects , Folic Acid/pharmacology , Interleukin-6/metabolism , Kidney/metabolism , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , Orphan Nuclear Receptors/metabolism , Receptors, Estrogen/genetics , Transcriptional ActivationABSTRACT
BACKGROUND: Intranasal (i.n.) drug application is a widely known and low-invasive route of administration that may be able to achieve rapid symptom control in terminally ill patients. According to the German S3 guideline "Palliative care for patients with incurable cancer", benzodiazepines, such as midazolam, are recommended for the treatment of terminal agitation. To the best of our knowledge there is no evidence for i.n. midazolam in terminally ill patients. We aim to assess the use of i.n. midazolam as an alternative to subcutaneous administration of the drug. METHODS: In this monocentric, randomised, controlled, open-label investigator initiated trial, n = 60 patients treated at the palliative care unit of a University Hospital will be treated with 5 mg midazolam i.n. versus 5 mg subcutaneous (s.c.) midazolam in the control arm when terminal agitation occurs (randomly assigned 1:1). The estimated recruitment period is 18 months. Treatment efficacy is defined as an improvement on the Richmond Agitation Sedation Scale (Palliative Version) (RASS-PAL) and a study specific numeric rating scale (NRS) before and after drug administration. Furthermore, plasma concentration determinations of midazolam will be conducted at t1 = 0 min, t2 = 5 min, and t3 = 20 min using liquid chromatography/mass spectrometry (LC-MS). The primary objective is to demonstrate non-inferiority of midazolam i.n. in comparison to midazolam s.c. for the treatment of agitation in terminally ill patients. DISCUSSION: Midazolam i.n. is expected to achieve at least equivalent reduction of terminal agitation compared to s.c. administration. In addition, plasma concentrations of midazolam i.n. are not expected to be lower than those of midazolam s.c. and the dynamics of the plasma concentration with an earlier increase could be beneficial. TRIAL REGISTRATION: German Clinical Trials Registry DRKS00026775, registered 07.07.2022, Eudra CT No.: 2021-004789-36.
Subject(s)
Midazolam , Terminally Ill , Humans , Midazolam/therapeutic use , Palliative Care , Treatment Outcome , Anxiety , Hypnotics and Sedatives/therapeutic use , Randomized Controlled Trials as TopicABSTRACT
OBJECTIVE: TGF-ß2 (TGF-ß, transforming growth factor beta), the less-investigated sibling of TGF-ß1, is deregulated in rodent and human liver diseases. Former data from bile duct ligated and MDR2 knockout (KO) mouse models for human cholestatic liver disease suggested an involvement of TGF-ß2 in biliary-derived liver diseases. DESIGN: As we also found upregulated TGFB2 in liver tissue of patients with primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC), we now fathomed the positive prospects of targeting TGF-ß2 in early stage biliary liver disease using the MDR2-KO mice. Specifically, the influence of TgfB2 silencing on the fibrotic and inflammatory niche was analysed on molecular, cellular and tissue levels. RESULTS: TgfB2-induced expression of fibrotic genes in cholangiocytes and hepatic stellate cellswas detected. TgfB2 expression in MDR2-KO mice was blunted using TgfB2-directed antisense oligonucleotides (AON). Upon AON treatment, reduced collagen deposition, hydroxyproline content and αSMA expression as well as induced PparG expression reflected a significant reduction of fibrogenesis without adverse effects on healthy livers. Expression analyses of fibrotic and inflammatory genes revealed AON-specific regulatory effects on Ccl3, Ccl4, Ccl5, Mki67 and Notch3 expression. Further, AON treatment of MDR2-KO mice increased tissue infiltration by F4/80-positive cells including eosinophils, whereas the number of CD45-positive inflammatory cells decreased. In line, TGFB2 and CD45 expression correlated positively in PSC/PBC patients and localised in similar areas of the diseased liver tissue. CONCLUSIONS: Taken together, our data suggest a new mechanistic explanation for amelioration of fibrogenesis by TGF-ß2 silencing and provide a direct rationale for TGF-ß2-directed drug development.
Subject(s)
Cholangitis, Sclerosing , Gene Silencing , Liver Cirrhosis, Biliary , Liver Cirrhosis , Oligonucleotides, Antisense , Transforming Growth Factor beta2/genetics , Transforming Growth Factor beta2/metabolism , ATP Binding Cassette Transporter, Subfamily B/genetics , Animals , Cholangitis, Sclerosing/metabolism , Cholangitis, Sclerosing/pathology , Disease Models, Animal , Drug Discovery , Gene Expression Regulation , Hepatic Stellate Cells/metabolism , Humans , Liver Cirrhosis/metabolism , Liver Cirrhosis/pathology , Liver Cirrhosis/prevention & control , Liver Cirrhosis, Biliary/metabolism , Liver Cirrhosis, Biliary/pathology , Mice , Mice, Knockout , Up-Regulation , ATP-Binding Cassette Sub-Family B Member 4ABSTRACT
Deregulation of apoptosis is a frequent alteration in early benign lesions of the colon mucosa and is thought to be a major contributor to tumor progression and cancer. Single nucleotide polymorphisms (SNPs) within apoptosis-related genes could affect apoptotic responses and their identification might provide a basis to assess individual risk for development of early lesions. To investigate a possible association between genetic polymorphisms and the occurrence of hyperplastic polyps (HP), we developed a custom DNA chip assay for 1,536 SNPs in the coding and flanking regions of 826 genes with known functional roles in apoptosis or apoptosis-associated (e.g., stress-related) pathways. During a first round of screening, genotypes were determined for 272 endoscopy patients harboring hyperplastic colorectal polyps and for 512 sex and aged-matched controls. A set of 14 candidate SNPs associated with HP (P < 0.01) was then evaluated in an independent cohort of patients (n = 38) and controls (n = 38). Following meta-analysis of Stages I and II, a false discovery rate approach was applied. Among the 14 candidate SNPs, eight showed significant association (combined P < 0.01) with the occurrence of HP. The SNPs rs4709583 (PARK2) and rs10476823 (HDAC3) were analyzed for potential functional effects on RNA splicing and RNA half-life. Despite its location near a splice site, alternative splicing was not detected for rs4709583 (PARK3). By contrast, cDNA analysis revealed use of a cryptic polyadenylation signal in the 3'UTR of HDAC3 mRNA and a longer mRNA half-life in a cell line heterozygous for rs10476823.
Subject(s)
Apoptosis/genetics , Intestinal Polyps/pathology , Polymorphism, Single Nucleotide , Aged , Case-Control Studies , Cohort Studies , Colonic Polyps/genetics , Colonic Polyps/pathology , Female , Genetic Association Studies , Genetic Markers , Genotype , Histone Deacetylases/genetics , Humans , Hyperplasia/genetics , Intestinal Polyps/genetics , Male , Metabolic Networks and Pathways , Middle Aged , Oligonucleotide Array Sequence Analysis , Rectum/pathologyABSTRACT
This report demonstrates a novel class of innate immune cells designated "variable immunoreceptor-expressing myeloids" (VIREMs). Using single-cell transcriptomics and genome-wide epigenetic profiling, we establish that VIREMs are myeloid cells unrelated to lymphocytes. We visualize the phenotype of B-VIREMs that are capable of genetically recombining and expressing antibody genes, the exclusive hallmark function of B lymphocytes. These cells, designated B-VIREMs, display monoclonal antibody cell surface signatures and regularly circulate in the blood of healthy individuals. Single-cell data reveal clonal expansion of circulating B-VIREMs as a dynamic response to disease stimuli. Live-cell imaging models suggest that B-VIREMs load their own Fc receptors with endogenous antibodies during vesicle transport to the cell surface. A first cloned B-VIREM-derived antibody (Vab1) specifically binds stomatin, a ubiquitous scaffold protein that is strictly expressed intracellularly, allowing Vab1-bearing macrophages to phagocytose cell debris without requiring prior opsonization. Our results suggest important antigen-specific tissue maintenance functionalities in these innate immune cells.
ABSTRACT
According to their carcinogenesis, colorectal cancer (CRC) subtypes show distinct molecular parameters. Hereditary non-polypous colorectal cancer (HNPCC) is the most common inherited CRC characterized by clinical criteria and confirmed microsatellite instability (MSI). Interestingly, a recently identified subtype, familial colorectal cancer type X (FCC-X), shows the same clinical criteria but microsatellite stability (MSS). CEACAM1 is a known tumor suppressor that regulates apoptosis in colon cells, and its loss is one of the most frequent events in early tumorigenesis of CRC. Therefore its loss may characterize precursor colon cells prior to neoplastic transformation. We analyzed tumor specimens of HNPCC and FCC-X patients in order to investigate whether there is a loss of CEACAM1 expression analogous to sporadic CRC and whether the expression of CEACAM1 would distinguish between these tumor entities. No differences in CEACAM1 expression were noted between HNPPC (n = 38) and FCC-X (n = 30) tumors. CEACAM1 was reduced in near-identical frequencies in 36/38 (95%) HNPCC and 29/30 (97%) FCC-X. This is the first report to demonstrate the loss of CEACAM1 expression in hereditary CRC. There was no difference between HNPCC and FCC-X. The frequency of expression loss was comparable to sporadic CRC, indicating that loss of CEACAM1 is an early event in colorectal tumorigenesis linking the genesis of sporadic and hereditary CRC.
Subject(s)
Antigens, CD/genetics , Cell Adhesion Molecules/genetics , Colorectal Neoplasms/congenital , Colorectal Neoplasms/genetics , Genes, Tumor Suppressor , Genetic Linkage/genetics , Genetic Predisposition to Disease/genetics , Adult , Aged , Female , Humans , Male , Middle AgedABSTRACT
OBJECTIVES: Respiratory gating with and without controlled ventilation has been applied for in vivo micro-computed tomography (micro-CT) of thoracic and abdominal structures in mice. We describe a simplified method for intubation and demonstrate its applicability for single-breath-hold micro-CT in mice. METHODS: Mice (n = 10) were anesthetized, intubated, ventilated, and relaxed by intraperitoneal administration of rocuronium. Contrast-enhanced micro-CT of the complete thorax including the upper abdominal organs (80 kV; 37.5 µA; 190-degree rotation; 600 projections/20 seconds or 1200 projections/40 seconds; 39 × 39 × 50-µm voxel size) was performed with and without single-breath-hold technique. RESULTS: The simplified method of intubation was fast (<1 minute) and required no special hardware in all mice. Relaxation of mice allowed prolonged single-breath-hold imaging of up to 40 seconds. Diameter of smallest identifiable lung vessels was 100 µm. CONCLUSIONS: The presented simplified method for intubation in mice is fast, safe, and effective. Additional relaxation allowed high-resolution single-breath-hold micro-CT in mice.
Subject(s)
Intubation, Intratracheal/methods , X-Ray Microtomography/methods , Androstanols/administration & dosage , Animals , Contrast Media , Disease Models, Animal , Liver Neoplasms, Experimental/diagnostic imaging , Mice , Mice, Inbred C57BL , Nanoparticles , Radiography, Abdominal/methods , Radiography, Thoracic/methods , Rocuronium , Transplantation, HeterologousABSTRACT
OBJECTIVE: Pituitary apoplexy is a serious medical complication of a pre-existing pituitary adenoma characterized by a variety of clinical symptoms ranging from mild headache to neurologically impaired and finally comatose patients. Management options are surgery or conservative treatment (e. g., with dexamethasone). Surgery is commonly performed in case of severe acute neurological and visual symptoms. However, prospective studies demonstrating a benefit of surgery over conservative treatment in terms of visual, neurological and even endocrine outcomes are lacking. Decision making is still controversial, and recommendations for surgery are based on low evidence grades and focus on visual impairment. Endocrine function and especially markers identifying patients with potential for pituitary recovery after surgery are not well described in the literature. PATIENTS AND DESIGN: We analysed data from 24 patients (m:f/16:8) with a median age of 64 yrs (38 to 83yrs) that underwent surgery for pituitary apoplexy regardless of time from symptom onset. Apoplexies were necrotic in 14 cases and haemorrhagic in 10 cases. RESULTS: Preoperatively, 7 patients (29.2%) showed complete anterior pituitary insufficiency, 16 patients (66.6%) had partial anterior pituitary insufficiency and one patient (4.17%) had normal pituitary functions. Persistent panhypopituitarism was found in 7 patients (29.2%), whereas an overall improvement of pituitary function was noted in 13 (57.1%) patients. Preoperative prolactin (PRL) levels were significantly associated with recovery of endocrine functions, whereas specifically all patients with preoperative PRL levels of at least 8.8 ng/ml recovered partially or fully. Time to surgery (0-7 days vs. 1-4 weeks vs.>4 weeks) was not significantly associated with outcome. CONCLUSIONS: Our data emphasize that normal and high preoperative PRL levels are associated with better endocrine outcome after surgery. We conclude that patients benefit from surgical intervention even after delayed diagnosis with the serum PRL levels is being a valid biomarker for clinical decision making.
Subject(s)
Hypopituitarism/metabolism , Neurosecretory Systems/metabolism , Outcome Assessment, Health Care , Pituitary Apoplexy/metabolism , Pituitary Apoplexy/surgery , Prolactin/metabolism , Adult , Aged , Aged, 80 and over , Biomarkers/metabolism , Female , Follow-Up Studies , Humans , Hypopituitarism/diagnosis , Male , Middle Aged , Pituitary Apoplexy/diagnosis , PrognosisABSTRACT
Internal image anti-idiotypic antibodies are capable of mimicking tumor-associated antigens and thus may serve as surrogate for vaccination strategies in cancer patients. The monoclonal antibody (mAb) 6G6.C4 mimics an epitope specific for the human carcinoembryonic antigen (CEA) and generates a CEA-specific response (Ab3) in various experimental animals. In humans, however, 6G6.C4 only yields a very limited humoral anti-CEA reaction presumably due to tolerance against the CEA autoantigen. In this study, we investigated the CEA-specific Ab3 response in mice transgenic for the human CEA and tested whether the antigen tolerance could be overcome by fusing a recombinant single-chain variable fragment of 6G6.C4 (scFv6G6.C4) to the murine granulocyte macrophage colony-stimulating factor (GM-CSF). Like mAb 6G6.C4, the fusion protein (scFv6G6.C4/GM-CSF) retained binding to the CEA-specific idiotype mAb T84.66. Also, scFv6G6.C4/GM-CSF was biologically active as measured by proliferation of the GM-CSF-dependent murine FDC-P1 cells in vitro. After immunization with the scFv6G6.C4/GM-CSF fusion protein, CEA-transgenic animals showed significantly enhanced Ab3 antibody responses to scFv6G6.C4 (P=0.005) and to CEA (P=0.012) compared with the scFV6G6.C4 alone. Sera from mice immunized with the fusion protein specifically recognized CEA in Western blot analyses with no cross-reaction to CEA-related antigens. Finally, the Ab3 antisera detected single CEA-expressing tumor cells in suspension as shown by flow cytometry. Taken together, these data show in a model antigenically related to the human system that vaccination with scFv6G6.C4/GM-CSF improves vaccination against an endogenous tumor-associated antigen resulting in a highly specific humoral Ab3 response in vivo that is capable of bind single circulating CEA-positive tumor cells.
Subject(s)
Antibodies, Anti-Idiotypic/immunology , Antibodies, Monoclonal/immunology , Carcinoembryonic Antigen/immunology , Colonic Neoplasms , Immune Tolerance , Animals , Antibody Specificity , Antigens, Neoplasm/immunology , Blotting, Western , Carcinoembryonic Antigen/metabolism , Cell Proliferation , Cells, Cultured , Colon/immunology , Colon/metabolism , Colonic Neoplasms/immunology , Colonic Neoplasms/metabolism , Colonic Neoplasms/therapy , Epitopes , Female , Granulocyte-Macrophage Colony-Stimulating Factor/immunology , Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Humans , Immunization , Immunoglobulin Fragments/immunology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Neoplastic Cells, Circulating/immunology , Neoplastic Cells, Circulating/metabolism , Recombinant Fusion Proteins/immunology , Recombinant Fusion Proteins/metabolismABSTRACT
OBJECTIVE: To analyze the performance of the 1 mg dexamethasone suppression test (DST) in patients with obesity. Special attention was paid to the influence of interfering medication on DST. METHODS: In this prospective cohort study (Mannheim Obesity Study), patients with obesity were evaluated before bariatric surgery. For evaluation of hypercortisolism, a 1 mg dexamethasone-suppression test (DST) in all subjects was performed. Medication was assessed for possible interference. RESULTS: Two hundred seventy-eight patients with a mean age of 42.3 years (68.8% women) and a mean BMI of 47.9 ± 8.4 kg/m(2) were screened. Insufficient suppression of cortisol after DST was found in 24 patients (8.6%). In two patients hypercortisolism was confirmed. The specificity for DST was calculated at 92.0%. Only CYP3A4 inducers (n = 22, 7.9%) and estrogen therapy (n = 17, 6.1%) were significantly associated with falsely elevated cortisol after DST. Regression analysis excluded any interrelation between DST and anthropometry. CONCLUSIONS: Low prevalence of hypercortisolism (0.7 or <1.8%) was found. Specificity of DST in this cohort typically screened for hypercortisolism was 92.0% (≤ 50 nmol/L). DST should be avoided in patients taking CYP3A4 inducers or estrogen therapy, due to their significant interaction. In summary, the 1 mg DST is an adequate test for screening for hypercortisolism even in patients with extreme obesity.
Subject(s)
Dexamethasone/therapeutic use , Diagnostic Techniques, Endocrine , Hydrocortisone/blood , Obesity, Morbid/complications , Obesity, Morbid/physiopathology , Adult , Cushing Syndrome/diagnosis , Female , Humans , Male , Middle Aged , Prospective StudiesABSTRACT
Defects in the adenomatous polyposis coli (APC) tumor suppressor pathway are sufficient for neoplastic transformation as the initiating step in colorectal carcinogenesis. In contrast, hyperplastic tumors possess normal APC function, and it is unclear whether they represent significant precursor lesion in cancer development. CEACAM1 is a tumor suppressor whose expression is known to be lost in the great majority of early adenomas and carcinomas. We found that loss of CEACAM1 expression is more common in neoplastic tumors than APC mutations. While APC function was normal in hyperplastic aberrant cypt foci and hyperplastic polyps, loss of CEACAM1 was observed as frequently as in the neoplasias. Moreover, the presence or absence of CEACAM1 expression in the hyperplastic tumors correlates with normal or reduced apoptosis, respectively. In vitro, CEACAM1 acts as a regulator of apoptosis in CEACAM1-transfected Jurkat cells. Finally, in human HT29 colon cancer cells, apoptosis can be specifically restored by induction of CEACAM1 expression. These data suggest an oncodevelopmental link between neoplasia and hyperplasia and demonstrate that CEACAM1 acts as a regulator of apoptosis in the colonic epithelium. Thus, failure of the maturing colon cell to express CEACAM1 is likely to contribute to the development of hyperplastic lesions, which may eventually pave the way to neoplastic transformation and colon cancer development.
Subject(s)
Antigens, CD/physiology , Antigens, Differentiation/physiology , Apoptosis/physiology , Colorectal Neoplasms/physiopathology , Genes, Tumor Suppressor , Antigens, CD/genetics , Antigens, Differentiation/genetics , Base Sequence , Cell Adhesion Molecules , Colorectal Neoplasms/genetics , DNA Primers , Genes, APC , Humans , In Vitro Techniques , MutationABSTRACT
PURPOSE: Colorectal cancer is one of the most common forms of cancer, and the development of novel tools for detection and efficient treatment of metastases is needed. One promising approach is the use of radiolabeled antibodies for positron emission tomography (PET) imaging and radioimmunotherapy. Since carcinoembryonic antigen (CEA) is an important target in colorectal cancer, the CEA-specific M5A antibody has been extensively studied in subcutaneous xenograft models; however, the M5A antibody has not yet been tested in advanced models of liver metastases. The aim of this study was to investigate the (64)Cu-DOTA-labeled M5A antibody using PET in mice bearing CEA-positive liver metastases. PROCEDURES: Mice were injected intrasplenically with CEA-positive C15A.3 or CEA-negative MC38 cells and underwent micro-computed tomography (micro-CT) to monitor the development of liver metastases. After metastases were detected, PET/MRI scans were performed with (64)Cu-DOTA-labeled M5A antibodies. H&E staining, immunohistology, and autoradiography were performed to confirm the micro-CT and PET/MRI findings. RESULTS: PET/MRI showed that M5A uptake was highest in CEA-positive metastases. The %ID/cm(3) (16.5% ± 6.3%) was significantly increased compared to healthy liver tissue (8.6% ± 0.9%) and to CEA-negative metastases (5.5% ± 0.6%). The tumor-to-liver ratio of C15A.3 metastases and healthy liver tissue was 1.9 ± 0.7. Autoradiography and immunostaining confirmed the micro-CT and PET/MRI findings. CONCLUSION: We show here that the (64)Cu-DOTA-labeled M5A antibody imaged by PET can detect CEA positive liver metastases and is therefore a potential tool for staging cancer, stratifying the patients or radioimmunotherapy.
Subject(s)
Antibodies , Carcinoembryonic Antigen , Copper Radioisotopes , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/secondary , Positron-Emission Tomography , Radioimmunodetection , Animals , Antibodies/chemistry , Antibodies/immunology , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/immunology , Antibody Specificity/immunology , Carcinoembryonic Antigen/chemistry , Carcinoembryonic Antigen/immunology , Cell Line, Tumor , Colorectal Neoplasms/pathology , Copper Radioisotopes/chemistry , Disease Models, Animal , Female , Immunoconjugates , Liver Neoplasms/pathology , Magnetic Resonance Imaging , Mice , Mice, Transgenic , Radioimmunodetection/methods , Radiopharmaceuticals , X-Ray MicrotomographyABSTRACT
RATIONALE AND OBJECTIVES: The purpose of this study was to compare different contrast agents for longitudinal liver and spleen imaging in a mouse model of liver metastasis. MATERIALS AND METHODS: Mice developing liver metastases underwent longitudinal micro-computed tomography imaging after injection of Fenestra LC, ExiTron nano 6000, or ExiTron nano 12000. Elimination times and contrast enhancement of liver and spleen were compared. RESULTS: For all contrast agents, liver contrast peaked at approximately 4 hours and spleen contrast at 48 hours postinjection. A single dose of 100 µL of ExiTron nano 6000 or 12000 resulted in longstanding enhancement of liver and spleen tissue for longer than 3 weeks, whereas repeated injections of 400 µL of Fenestra LC were required to retain contrast at acceptable levels and allowed imaging of the liver/spleen for up to 2 and 9 days, respectively. CONCLUSION: Both ExiTron nano agents provide longer and stronger contrast enhancement of liver and spleen compared to Fenestra LC, and they do so at a 75% lower injection volume in mice.
Subject(s)
Contrast Media , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/secondary , Splenic Neoplasms/diagnostic imaging , Tomography, X-Ray Computed/veterinary , Animals , Cell Line, Tumor , Image Enhancement/methods , Liver/diagnostic imaging , Mice , Mice, Inbred C57BL , Reproducibility of Results , Sensitivity and Specificity , Spleen/diagnostic imaging , Tomography, X-Ray Computed/methodsABSTRACT
Various murine models are currently used to study acute and chronic pathological processes of the liver, and the efficacy of novel therapeutic regimens. The increasing availability of high-resolution small animal imaging modalities presents researchers with the opportunity to precisely identify and describe pathological processes of the liver. To meet the demands, the objective of this study was to provide a three-dimensional illustration of the macroscopic anatomical location of the murine liver lobes and hepatic vessels using small animal imaging modalities. We analysed micro-CT images of the murine liver by integrating additional information from the published literature to develop comprehensive illustrations of the macroscopic anatomical features of the murine liver and hepatic vasculature. As a result, we provide updated three-dimensional illustrations of the macroscopic anatomy of the murine liver and hepatic vessels using micro-CT. The information presented here provides researchers working in the field of experimental liver disease with a comprehensive, easily accessable overview of the macroscopic anatomy of the murine liver.
Subject(s)
Imaging, Three-Dimensional/methods , Liver/anatomy & histology , Liver/diagnostic imaging , X-Ray Microtomography/methods , Animals , Biliary Tract/anatomy & histology , Biliary Tract/diagnostic imaging , Hepatic Veins/anatomy & histology , Hepatic Veins/diagnostic imaging , Liver/blood supply , MiceABSTRACT
Separase, an endopeptidase required for the separation of sister-chromatides in mitotic anaphase, triggers centriole disengagement during centrosome duplication. In cancer, separase is frequently overexpressed, pointing to a functional role as an aneuploidy promoter associated with centrosomal amplification and genomic instability. Recently, we have shown that centrosomal amplification and subsequent chromosomal aberrations are a hallmark of chronic myeloid leukemia (CML), increasing from chronic phase (CP) toward blast crisis (BC). Moreover, a functional linkage of p210BCR-ABL tyrosine kinase activity with centrosomal amplification and clonal evolution has been established in long-term cell culture experiments. Unexpectedly, therapeutic doses of imatinib (IM) did not counteract; instead induced similar centrosomal alterations in vitro. We investigated the influence of IM and p210BCR-ABL on Separase as a potential driver of centrosomal amplification in CML. Short-term cell cultures of p210BCR-ABL-negative (NHDF, UROtsa, HL-60, U937), positive (K562, LAMA-84) and inducible (U937p210BCR-ABL/c6 (Tet-ON)) human cell lines were treated with therapeutic doses of IM and analyzed by qRT-PCR, Western blot analysis and quantitative Separase activity assays. Decreased Separase protein levels were observed in all cells treated with IM in a dose dependent manner. Accordingly, in all p210BCR-ABL-negative cell lines, decreased proteolytic activity of Separase was found. In contrast, p210BCR-ABL-positive cells showed increased Separase proteolytic activity. This activation of Separase was consistent with changes in the expression levels of Separase regulators (Separase phosphorylation at serine residue 1126, Securin, CyclinB1 and PP2A). Our data suggest that regulation of Separase in IM-treated BCR-ABL-positive cells occurs on both the protein expression and the proteolytic activity levels. Activation of Separase proteolytic activity exclusively in p210BCR-ABL-positive cells during IM treatment may act as a driving force for centrosomal amplification, contributing to genomic instability, clonal evolution and resistance in CML.
Subject(s)
Antineoplastic Agents/pharmacology , Blast Crisis/drug therapy , Fusion Proteins, bcr-abl/metabolism , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Piperazines/pharmacology , Pyrimidines/pharmacology , Benzamides , Blast Crisis/enzymology , Blast Crisis/genetics , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Cyclin B1/genetics , Cyclin B1/metabolism , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/genetics , Endopeptidases/genetics , Endopeptidases/metabolism , Fusion Proteins, bcr-abl/genetics , Genomic Instability/drug effects , Genomic Instability/genetics , HL-60 Cells , Humans , Imatinib Mesylate , K562 Cells , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/enzymology , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Neoplasm Proteins/genetics , Neoplasm Proteins/metabolism , Phosphorylation/drug effects , Phosphorylation/genetics , Protein Phosphatase 2/genetics , Protein Phosphatase 2/metabolism , Proteolysis , Securin , Separase , U937 CellsABSTRACT
BACKGROUND: Micro-CT imaging of liver disease in mice relies on high soft tissue contrast to detect small lesions like liver metastases. Purpose of this study was to characterize the localization and time course of contrast enhancement of a nanoparticular alkaline earth metal-based contrast agent (VISCOVER ExiTron nano) developed for small animal liver CT imaging. METHODOLOGY: ExiTron nano 6000 and ExiTron nano 12000, formulated for liver/spleen imaging and angiography, respectively, were intravenously injected in C57BL/6J-mice. The distribution and time course of contrast enhancement were analysed by repeated micro-CT up to 6 months. Finally, mice developing liver metastases after intrasplenic injection of colon carcinoma cells underwent longitudinal micro-CT imaging after a single injection of ExiTron nano. PRINCIPAL FINDINGS: After a single injection of ExiTron nano the contrast of liver and spleen peaked after 4-8 hours, lasted up to several months and was tolerated well by all mice. In addition, strong contrast enhancement of abdominal and mediastinal lymph nodes and the adrenal glands was observed. Within the first two hours after injection, particularly ExiTron nano 12000 provided pronounced contrast for imaging of vascular structures. ExiTron nano facilitated detection of liver metastases and provided sufficient contrast for longitudinal observation of tumor development over weeks. CONCLUSIONS: The nanoparticulate contrast agents ExiTron nano 6000 and 12000 provide strong contrast of the liver, spleen, lymph nodes and adrenal glands up to weeks, hereby allowing longitudinal monitoring of pathological processes of these organs in small animals, with ExiTron nano 12000 being particularly optimized for angiography due to its very high initial vessel contrast.