To elucidate the pure impact of microgravity on small mammals despite uncontrolled factors that exist in the International Space Station, it is necessary to construct a 1 g environment in space. The Japan Aerospace Exploration Agency has developed a novel mouse habitat cage unit that can be installed in the Cell Biology Experiment Facility in the Kibo module of the International Space Station. The Cell Biology Experiment Facility has a short-arm centrifuge to produce artificial 1 g gravity in space for mouse experiments. However, the gravitational gradient formed inside the rearing cage is larger when the radius of gyration is shorter; this may have some impact on mice. Accordingly, biological responses to hypergravity induced by a short-arm centrifuge were examined and compared with those induced by a long-arm centrifuge. Hypergravity induced a significant Fos expression in the central nervous system, a suppression of body mass growth, an acute and transient reduction in food intake, and impaired vestibulomotor coordination. There was no difference in these responses between mice raised in a short-arm centrifuge and those in a long-arm centrifuge. These results demonstrate the feasibility of using a short-arm centrifuge for mouse experiments.
Eyelid myoclonia with absences is classified as a unique type of generalized seizure. Its pathogenesis is proposed to involve the functional abnormalities in cortical–subcortical networks. Here, we describe the case of a 7-year-old boy who had eyelid myoclonia with absences, along with focal motor seizures. Video-EEG monitoring demonstrated eyelid myoclonia associated with 4- to 5-Hz generalized polyspike–waves preceded by focal frontal discharges. Interictal EEG showed focal epileptiform discharges over the frontal regions. Our case suggests an important role of the frontal lobe in the generation of eyelid myoclonia with absences.
Eyelid myoclonia; Absences; Generalized seizures; Video-EEG; Frontal lobe
Primitive neuroectodermal tumor (PNET) is a member of the Ewing's sarcoma family of tumors (ESFT). We report a case of PNET in a 66-year-old male who presented with a large solid tumor within the parenchyma of the middle pole of the left kidney with metastases to the left adrenal gland and right ischium. A fine-needle biopsy was performed and showed a small round cell tumor. Results of immunohistochemical staining suggested this tumor belonged to ESFT. Preoperative VDC-IE (combined vincristine, doxorubicin and cyclophosphamide followed by another combination of ifosfamide and etoposide) chemotherapy and left radical nephrectomy and adrenalectomy were performed. The histopathological findings of the resected tumor were similar to those in the biopsy specimen, but the results of AE1/AE3 were different. For the diagnosis, fluorescence in situ hybridization was performed. Split signals of the EWSR1 gene were detected, and transmission electron microscopy showed neuroendocrine granules and microtubules. The final diagnosis of this tumor was PNET of the kidney.
Primitive neuroectodermal tumor; Kidney; Fluorescence in situ hybridization; VDC-IE chemotherapy
Nucleostemin (NS) is a nucleolar GTP-binding protein that is involved in a plethora of functions including ribosomal biogenesis and maintenance of telomere integrity. In addition to its expression in cancerous cells, the NS gene is expressed in stem cells including embryonic stem cells (ESCs). Previous knockdown and knockout studies have demonstrated that NS is important to preserve the self-renewality and high expression levels of pluripotency marker genes in ESCs. Here, we found that forced expression of Nanog or Esrrb, but not other pluripotency factors, resulted in the dispensability of NS expression in ESCs. However, the detrimental phenotypes of ESCs associated with ablation of NS expression were not mitigated by forced expression of Rad51 or a nucleolar localization-defective NS mutant that counteracts the damage associated with loss of NS expression in other NS-expressing cells such as neural stem/progenitor cells. Thus, our results indicate that NS participates in preservation of the viability and integrity of ESCs, which is distinct from that in other NS-expressing cells. Stem Cells
Embryonic stem cells; Epiblast stem cells; Leukemia inhibitory factor; Pluripotency
Differentiation of T helper 17 cells is dependent on the expression of transcription retinoid-related orphan receptor gamma t (RORγt). The purpose of our study is to determine the role of RORγt expression in T cells on the development of collagen-induced arthritis (CIA).
CIA was induced in C57BL/6 and T cell-specific RORγt transgenic (RORγt Tg) mice. At day 10 post-1st-immunization, lymph node (LN) cells were cultured with type II collagen (CII), and the expression levels of various cytokines and transcription factors on CD4+ T cells were measured. Total cells or CD4+ cells of draining LN were harvested from each mouse group after CII-immunization and transferred into C57BL/6 mice, and then CIA was induced in recipient mice. The expression levels of RORγt and other surface antigens, and the production of cytokines were analyzed in forkhead box P3 (Foxp3)+ regulatory T (Treg) cells. Foxp3+ Treg cells were analyzed for suppressive activity against proliferation of effector CD4+ T cells. Interlukin (IL)-10 neutralizing antibody was administrated in the course of CIA.
CIA was significantly suppressed in RORγt Tg mice compared with C57BL/6 mice. RORγt expression and IL-17 production were significantly higher in CII-reactive CD4+ T cells from RORγt Tg mice. Arthritis was significantly attenuated in C57BL/6 mice recipient of cells from RORγt Tg mice. Most of Foxp3+ Treg cells expressed RORγt, produced IL-10 but not IL-17, and overexpressed CC chemokine receptor 6 (CCR6) and surface antigens related to the suppressive activity of Foxp3+ Treg cells in RORγt Tg mice. In vitro suppression assay demonstrated significant augmentation of the suppressive capacity of Foxp3+ Treg cells in RORγt Tg mice. CIA was exacerbated in both C57BL/6 mice and RORγt Tg mice by the treatment of anti-IL-10 antibody.
Our results indicated that RORγt overexpression in T cells protected against the development of CIA. The protective effects were mediated, at least in part, through the anti-inflammatory effects including high production of IL-10 of RORγt+Foxp3+ Treg cells.
Androgen receptor (AR) signaling is essential for the development of prostate cancer. Here, we report that runt-related transcription factor (RUNX1) could be a key molecule for the androgen-dependence of prostate cancer. We found RUNX1 is a target of AR and regulated positively by androgen. Our RUNX1 ChIP-seq analysis indicated that RUNX1 is recruited to AR binding sites by interacting with AR. In androgen-dependent cancer, loss of RUNX1 impairs AR-dependent transcription and cell growth. The RUNX1 promoter is bound by enhancer of zeste homolog 2 (EZH2) and is negatively regulated by histone H3 lysine 27 (K27) trimethylation. Repression of RUNX1 is important for the growth promotion ability of EZH2 in AR-independent cells. In clinical prostate cancer samples, the RUNX1 expression level is negatively associated with EZH2 and that RUNX1 loss correlated with poor prognosis. These results indicated the significance of RUNX1 for androgen-dependency and that loss of RUNX1 could be a key step for the progression of prostate cancer.
RUNX1; androgen receptor; EZH2; prostate cancer
Herein, we investigated therapeutic potential of a novel histone lysine demethylase 1 (LSD1) inhibitor, NCL1, in prostate cancer. Hormone-sensitive prostate cancer cells, (LNCaP) and castration resistant cancer cells (PC3 and PCai1) were treated with NCL1, and LSD1 expression and cell viability were assessed. Prostate cancer cells showed strong LSD1 expression, and cell viability was decreased by NCL1. ChIP analysis showed that NCL1 induced H3K9me2 accumulation at the promoters of androgen-responsive genes. NCL1 also induced G1 cell cycle arrest and apoptosis. In addition, autophagosomes and autolysosomes were induced by NCL1 treatment in LNCaP. Furthermore, LC3-II expression was significantly increased by NCL1 and chloroquine. In mice injected subcutaneously with PCai1 and intraperitoneally with NCL1, tumor volume was reduced with no adverse effects in NCL1-treated mice. Finally, LSD1 expression in human cancer specimens was significantly higher than that in normal prostate glands. In conclusion, NCL1 effectively suppressed prostate cancer growth without adverse events. We suggest that NCL1 is a potential therapeutic agent for hormone-resistant prostate cancer.
LSD1; epigenetics; prostate cancer; autophagy
Background and Purpose
To investigate the diagnostic performance of diffusion-weighted imaging (DWI) and contrast-enhanced imaging in combination with T2-weighted imaging (T2WI) for magnetic resonance imaging (MRI) evaluation of intrapelvic recurrence of gynecological malignancies.
Materials and Methods
Sixty-two patients with suspected intrapelvic recurrence of gynecological malignancies underwent pelvic MRI including T2WI DWI, and contrast-enhanced imaging. Diagnostic performance for detection of local recurrence, pelvic lymph node and bone metastases, and peritoneal lesions was evaluated by consensus reading of two experienced radiologists using a 5-point scoring system, and compared among T2WI with unenhanced T1-weighted imaging (T1WI) (protocol A), a combination of protocol A and DWI (protocol B), and a combination of protocol B and contrast-enhanced imaging (protocol C). Final diagnoses were obtained by histopathological examinations, radiological imaging and clinical follow-up for at least 6 months. Receiver operating characteristic (ROC) analysis and McNemar test were employed for statistical analysis.
Locally recurrent disease, lymph node recurrence, peritoneal dissemination and bone metastases were present in 48.4%, 29.0%, 16.1%, and 6.5% of the patients, respectively. The patient-based sensitivity, specificity, accuracy, and area under the ROC curve (AUC) for detection of intrapelvic recurrence were 55.0, 81.8, 64.5% and 0.753 for protocol A, 80.0, 77.3, 79.0% and 0.838 for protocol B, and 80.0, 90.9, 83.9% and 0.862 for protocol C, respectively. The sensitivity, accuracy, and AUC were significantly better for protocols B and C than for protocol A (p<0.001). There was no significant difference between protocols B and C.
MRI using a combination of DWI and T2WI gives comparatively acceptable results for assessment of intrapelvic recurrence of gynecological malignancies.
We previously established 3 cell lines (PLS10, PLS20 and PLS30) from a chemically-induced prostate carcinoma in F344 rats, and demonstrated high potential for metastasis in nude mice. In the present study, we investigated the feasibility of establishing an orthotopic model using the 3 rat prostate cancer cell lines in immunocompetent rats with the aim of resolving species-mismatch problems and defects of immune systems. The PLS10, PLS20 and PLS30 cell lines were injected into the ventral prostates of 6-week-old rats, which were then sacrificed at experimental weeks 4 and 8. Tumor mass formation was found in rats with PLS10, but not in those with PLS20 or PLS30. Additionally, metastatic carcinomas could be detected in lymph nodes and lungs of PLS10-inoculated rats. Genetic analysis demonstrated K-ras gene mutations in PLS10 and PLS20, but not in PLS30 cells. There were no mutations in p53 and KLF6. In conclusion, we established a syngeneic orthotopic model for prostate cancer in immunocompetent rats simulating human castration-resistant prostate cancer (CRPC), which should prove useful for development and validation of therapeutic agents, especially with immunotherapy.
orthotopic model; prostate cancer; rats; immunocompetent animal
There are many molecular differences between estrogen receptor α (ERα)-positive and ER-negative breast cancers. Recent analyses have shown that the former can be divided into two subtypes, luminal A and luminal B. These differ in response to endocrine therapy and chemotherapy, and in prognosis. In a previous study, we found that microRNA (miR)-1290 that was significantly down-regulated in luminal A tumors and its potential target arylamine N-acetyltransferase 1 (NAT1). The aim of the present study was to determine whether NAT1 is a bona fide target of miR-1290, and to investigate the impact of NAT1 on breast cancer prognosis.
Luciferase reporter assays were employed to validate NAT1 as a putative miR-1290 target gene. Expression of NAT1, ERα, progesterone receptor (PgR) and HER2 was analyzed in 394 breast cancer samples by immunohistochemistry.
NAT1 was confirmed to be a direct target of miR-1290. Levels of expression of NAT1 were positively correlated with those of ERα (P < 0.0001) and PgR (P < 0.0001), but negatively correlated with both tumor grade and size (P < 0.0001). Kaplan-Meier analysis showed that the presence of NAT1 was significantly associated with increased overall survival (OS) (P = 0.0416) in these patients. Similarly, significant associations of NAT1 with disease-free survival (DFS) (P = 0.0048) and OS (P = 0.0055) in those patients who received adjuvant endocrine therapy with tamoxifen (n = 176) were found. Moreover, NAT1 was also significantly associated with increased DFS (P = 0.0025) and OS (P = 0.0007) in the subset of lymph node-positive patients (n = 147). Univariate and multivariate analyses showed significant associations between levels of NAT1 and DFS (P = 0.0005 and 0.019, respectively).
We report that miR-1290 directly targets the NAT1 3′-UTR and that NAT1 protein expression is correlated with improved OS of breast cancer patients. NAT1 is a possible prognostic biomarker for lymph node-positive breast cancer. Thus, miR-1290 and its target NAT1 are associated with important characteristics of breast cancer.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2407-14-990) contains supplementary material, which is available to authorized users.
Breast cancer; miR-1290; Arylamine N-acetyltransferase 1 (NAT1)
Recent studies on the large Maf transcription factors have shown that Mafb and Mafa have respective and distinctive roles in β-cell development and maturation. However, whether this difference in roles is due to the timing of the gene expression (roughly, expression of Mafb before birth and of Mafa after birth) or to the specific function of each gene is unclear. Our aim was to examine the functional differences between these genes that are closely related to β cells by using an in vivo model of β-like cell generation. We monitored insulin gene transcription by measuring bioluminescence emitted from the liver of insulin promoter-luciferase transgenic (MIP-Luc-VU) mice. Adenoviral gene transfers of Pdx1/Neurod/Mafa (PDA) and Pdx1/Neurod/Mafb (PDB) combinations generated intense luminescence from the liver that lasted for more than 1 week and peaked at 3 days after transduction. The peak signal intensities of PDA and PDB were comparable. However, PDA but not PDB transfer resulted in significant bioluminescence on day 10, suggesting that Mafa has a more sustainable role in insulin gene activation than does Mafb. Both PDA and PDB transfers ameliorated the glucose levels in a streptozotocin (STZ)-induced diabetic model for up to 21 days and 7 days, respectively. Furthermore, PDA transfer induced several gene expressions necessary for glucose sensing and insulin secretion in the liver on day 9. However, a glucose tolerance test and liver perfusion experiment did not show glucose-stimulated insulin secretion from intrahepatic β-like cells. These results demonstrate that bioluminescence imaging in MIP-Luc-VU mice provides a noninvasive means of detecting β-like cells in the liver. They also show that Mafa has a markedly intense and sustained role in β-like cell production in comparison with Mafb.
Mutually exclusive expression of T-bet and Eomes drives the development of distinct NK cell lineages with complementary functions.
Trail+DX5−Eomes− natural killer (NK) cells arise in the mouse fetal liver and persist in the adult liver. Their relationships with Trail−DX5+ NK cells remain controversial. We generated a novel Eomes-GFP reporter murine model to address this question. We found that Eomes− NK cells are not precursors of classical Eomes+ NK cells but rather constitute a distinct lineage of innate lymphoid cells. Eomes− NK cells are strictly dependent on both T-bet and IL-15, similarly to NKT cells. We observed that, in the liver, expression of T-bet in progenitors represses Eomes expression and the development of Eomes+ NK cells. Reciprocally, the bone marrow (BM) microenvironment restricts T-bet expression in developing NK cells. Ectopic expression of T-bet forces the development of Eomes− NK cells, demonstrating that repression of T-bet is essential for the development of Eomes+ NK cells. Gene profile analyses show that Eomes− NK cells share part of their transcriptional program with NKT cells, including genes involved in liver homing and NK cell receptors. Moreover, Eomes− NK cells produce a broad range of cytokines, including IL-2 and TNF in vitro and in vivo, during immune responses against vaccinia virus. Thus, mutually exclusive expression of T-bet and Eomes drives the development of different NK cell lineages with complementary functions.
Despite convincing evidence that 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)—a heterocyclic amine generated by cooking meats at high temperatures—is carcinogenic in animal models, it remains unclear whether PhIP exposure leads to increased cancer risk in humans. PhIP-DNA adduct levels were measured in specimens from 534 prostate cancer case-control pairs nested within a historical cohort of men with histopathologically benign prostate specimens. We estimated the overall and race-stratified risk of subsequent prostate cancer associated with higher adduct levels. PhIP-DNA adduct levels in benign prostate were significantly higher in Whites than African Americans (0.274 Optical Density Units (OD) ±0.059 vs. 0.256 OD ±0.054; p<0.0001). Prostate cancer risk for men in the highest quartile of PhIP-DNA adduct levels was modestly increased (Odds Ratio (OR) = 1.25; 95% confidence interval (CI) = 0.76-2.07). In subset analyses, the highest risk estimates were observed in White patients diagnosed more than 4 years after cohort entry (OR=2.74; 95% CI=1.01-7.42) or under age 65 (OR=2.80; 95% CI=0.87-8.97). In Whites, cancer risk associated with high grade prostatic intraepithelial neoplasia combined with elevated PhIP-DNA adduct levels (OR=3.89; 95% CI=1.56-9.73) was greater than risk associated with either factor alone. Overall, elevated levels of PhIP-DNA adducts do not significantly increase prostate cancer risk. However, our data show that White men have higher PhIP-DNA adduct levels in benign prostate tissue than African American men, and suggest that in certain subgroups of White men high PhIP-DNA adduct levels may predispose to an increased risk for prostate cancer.
dna adducts; nested case-control study; immunohistochemistry; carcinogens; imidazoles; biopsy, needle
The postnatal proliferation and maturation of insulin-secreting pancreatic β-cells are critical for glucose metabolism and disease development in adults. Elucidation of the molecular mechanisms underlying these events will be beneficial to direct the differentiation of stem cells into functional β-cells. Maturation of β-cells is accompanied by increased expression of MafA, an insulin gene transcription factor. Transcriptome analysis of MafA knockout islets revealed MafA is required for the expression of several molecules critical for β-cell function, including Glut2, ZnT8, Granuphilin, Vdr, Pcsk1 and Urocortin 3, as well as Prolactin receptor (Prlr) and its downstream target Cyclin D2 (Ccnd2). Inhibition of MafA expression in mouse islets or β-cell lines resulted in reduced expression of Prlr and Ccnd2, and MafA transactivated the Prlr promoter. Stimulation of β-cells by prolactin resulted in the phosphorylation and translocation of Stat5B and an increased nuclear pool of Ccnd2 via Prlr and Jak2. Consistent with these results, the loss of MafA resulted in impaired proliferation of β-cells at 4 weeks of age. These results suggest that MafA regulates the postnatal proliferation of β-cells via prolactin signaling.
Paroxysmal kinesigenic dyskinesia is characterized by sudden attacks of involuntary movements. It is often misdiagnosed clinically as psychogenic illness, which distresses the patients to a great extent. A correct diagnosis will improve the quality of life in patients with paroxysmal kinesigenic dyskinesia because treatment with low doses of anticonvulsants is effective for eliminating the clinical manifestations. Paroxysmal kinesigenic dyskinesia can occur independently of or concurrently with benign infantile convulsion. Identification of PRRT2 as the causative gene of benign infantile convulsion and paroxysmal kinesigenic dyskinesia allows genetic confirmation of the clinical diagnosis.
We describe the clinical features of a Japanese family with either paroxysmal kinesigenic dyskinesia or benign infantile convulsion. A PRRT2 missense mutation (c.981C > G, p.Ile327Met) was identified in two patients with benign infantile convulsion and three patients with paroxysmal kinesigenic dyskinesia as well as in two unaffected individuals. Allowing incomplete penetrance in the mutation carriers, this mutation co-segregated completely with the phenotype. The patients with paroxysmal kinesigenic dyskinesia had been misdiagnosed with psychogenic illness for many years. They were correctly diagnosed with paroxysmal kinesigenic dyskinesia when their children visited a pediatrician for benign infantile convulsion. Treatment with carbamazepine controlled their involuntary movements completely.
Paroxysmal kinesigenic dyskinesia is a treatable movement disorder that is often misdiagnosed clinically as psychogenic illness. It is important to note that two clinically distinct disorders, benign infantile convulsion and paroxysmal kinesigenic dyskinesia, are allelic conditions caused by PRRT2 mutations. Paroxysmal kinesigenic dyskinesia should be suspected in families with a child with benign infantile convulsion.
Benign infantile convulsion; Mutation; Paroxysmal kinesigenic dyskinesia; PRRT2; Seizures
Activation of peroxisome proliferator-activated receptor (PPAR) α disrupts growth-related activities in a variety of human cancers. This study was designed to determine whether fenofibrate, a PPARα agonist, can suppress 4-nitroquinoline 1-oxide (4-NQO)-induced proliferative lesions in the lung of obese hyperlipidemic mice. Male Tsumura Suzuki Obese Diabetic mice were subcutaneously injected with 4-NQO to induce lung proliferative lesions, including adenocarcinomas. They were then fed a diet containing 0.01% or 0.05% fenofibrate for 29 weeks, starting 1 week after 4-NQO administration. At week 30, the incidence and multiplicity (number of lesions/mouse) of pulmonary proliferative lesions were lower in mice treated with 4-NQO and both doses of fenofibrate compared with those in mice treated with 4-NQO alone. The incidence and multiplicity of lesions were significantly lower in mice treated with 4-NQO and 0.05% fenofibrate compared with those in mice treated with 4-NQO alone (p < 0.05). Both doses of fenofibrate significantly reduced the proliferative activity of the lesions in 4-NQO-treated mice (p < 0.05). Fenofibrate also significantly reduced the serum insulin and insulin-like growth factor (IGF)-1 levels, and decreased the immunohistochemical expression of IGF-1 receptor (IGF-1R), phosphorylated Akt, and phosphorylated Erk1/2 in lung adenocarcinomas. Our results indicate that fenofibrate can prevent the development of 4-NQO-induced proliferative lesions in the lung by modulating the insulin-IGF axis.
4-nitroquinoline-1-oxide; lung neoplasms; carcinogenesis; hyperlipidemia; hyperinsulinemia; chemoprevention
We have established a transgenic rat for adenocarcinoma of the prostate (TRAP) model that features uniform adenocarcinoma development in prostatic lobes at high incidence within a short experimental period. However, no invasive carcinomas with reactive stroma characteristics similar to those in man were observed. We therefore have focused on a new model for invasive carcinoma of the prostate using TRAP rats. In experiment 1, male TRAP rats in groups 1 and 2 were treated with orchiectomy at day 0 of the experiment. Rats in groups 1–3 underwent testosterone propionate (TP) implantation from weeks 1 to 4 and from weeks 6 to 16. Rats in groups 1 and 3 were given 3,2’-dimethyl-4-aminobiphenyl (DMAB) after TP implantation. The rats of group 4 served as controls. In experiment 2, the rats were divided into three groups, none of which received DMAB or orchiectomy, treated with TP continuously or with the treatment withdrawn once or twice. In experiment 1, invasive adenocarcinomas with abundant collagenous stroma were found in the dorsolateral and anterior prostate, some of which showed perineural space invasion at week 16. The number of invasive carcinoma foci was most frequent in group 3. In experiment 2, invasive adenocarcinoma development in the lateral prostates was correlated with the number of TP administration/withdrawal cycles. In conclusion, our newly established rat model for invasive adenocarcinoma of the prostate could serve as a useful preclinical model for evaluating the in vivo efficacy of preventive and therapeutic agents targeting of the tumor microenvironment.
prostate cancer; animal model; cancer invasion; transgenic rat; testosterone propionate; intermittent administration
Infusion fluids may be contaminated with different types of particulates that are a potential health hazard. Particulates larger than microvessels may cause an embolism by mechanical blockage and inflammation; however, it has been reported that particulates smaller than capillary diameter are relatively safe. Against such a background, one report showed that polystyrene beads smaller than capillary diameter decreased tissue perfusion in ischemia–reperfusion injury. This report suggested that polystyrene beads from 1.5- to 6-μm diameter (dia.) may have unfavorable effects after pretreatment.
Here, we investigated whether injection of polystyrene beads (3- and 6-μm dia.) as an artificial contaminant of intravenous fluid after lipopolysaccharide (LPS) injection affected mortality and organ damage in mice.
Mice were divided into four groups and injected: polystyrene beads only, LPS only, polystyrene beads 30 min after LPS, or saline. A survival study, histology, blood examination, and urine examination were performed.
The survival rate after LPS and polystyrene bead (6-μm dia.) injection was significantly lower than that of the other three groups. In the kidney sections, injured glomeruli were significantly higher with LPS and polystyrene bead injection than that of the other three groups. LPS and polystyrene bead injection decreased the glomerular filtration rate and led to renal failure. Inflammatory reactions induced with LPS were not significantly different between with or without polystyrene beads. Polystyrene beads were found in urine after LPS and polystyrene bead injection.
Injection of polystyrene beads after LPS injection enhanced glomerular structural injury and caused renal function injury in a mouse sepsis model.
IV injection; Polystyrene beads; Glomerular injury
Cyclin-dependent kinase 5 (Cdk5) is essential for brain development and function, and its deregulated expression is implicated in some of neurodegenerative diseases. We reported earlier that the forebrain-specific Cdk5 conditional knockout (cKO) mice displayed an early lethality associated with neuroinflammation, increased expression of the neuronal tissue-type plasminogen activator (tPA), and neuronal migration defects.
In order to suppress neuroinflammation in the cKO mice, we first treated these mice with pioglitazone, a PPARγ agonist, and analyzed its effects on neuronal loss and longevity. In a second approach, to delineate the precise role of tPA in neuroinflammation in these mice, we generated Cdk5 cKO; tPA double knockout (dKO) mice.
We found that pioglitazone treatment significantly reduced astrogliosis, microgliosis, neuronal loss and behavioral deficit in Cdk5 cKO mice. Interestingly, the dKO mice displayed a partial reversal in astrogliosis, but they still died at early age, suggesting that the increased expression of tPA in the cKO mice does not contribute significantly to the pathological process leading to neuroinflammation, neuronal loss and early lethality.
The suppression of neuroinflammation in Cdk5 cKO mice ameliorates gliosis and neuronal loss, thus suggesting the potential beneficial effects of the PPARγ agonist pioglitazone for the treatment for neurodegenerative diseases.
Neuroinflammation; Cdk5; Pioglitazone; tPA; Cdk5 conditional knockout mice
T helper (Th)2 cells have been proposed to play a neuroprotective role in multiple sclerosis (MS). This is mainly based on “loss-of-function” studies in an animal model for MS, experimental autoimmune encephalomyelitis (EAE), using blocking antibodies against Th2 related cytokines, and knockout mice lacking Th2-related molecules. We tested whether an increase of Th2 responses (“gain-of-function” approach) could alter EAE, the approach of novel GATA binding protein 3 (GATA3)-transgenic (tg) mice that overexpress GATA3, a transcription factor required for Th2 differentiation. In EAE induced with myelin oligodendrocyte glycoprotein (MOG)35–55 peptide, GATA3-tg mice had a significantly delayed onset of disease and a less severe maximum clinical score, compared with wild-type C57BL/6 mice. Histologically, GATA3-tg mice had decreased levels of meningitis and demyelination in the spinal cord, and anti-inflammatory cytokine profiles immunologically, however both groups developed similar levels of MOG-specific lymphoproliferative responses. During the early stage, we detected higher levels of interleukin (IL)-4 and IL-10, with MOG and mitogen stimulation of regional lymph node cells in GATA3-tg mice. During the late stage, only mitogen stimulation induced higher IL-4 and lower interferon-γ and IL-17 production in GATA3-tg mice. These results suggest that a preexisting bias toward a Th2 immune response may reduce the severity of inflammatory demyelinating diseases, including MS.
autoimmune demyelinating diseases; GATA3 transcription factor; autoimmunity; animal models; paraffin; histology; oligodendrocyte-myelin glycoprotein; Th1-Th2 assays; Luxol fast blue; Th17; incomplete Freund’s adjuvant
Ulcerative colitis (UC) is an inflammatory bowel disease, and its pathogenesis includes
genetic, environmental, and immunological factors, such as T helper cells and their
secreted cytokines. T helper cells are classified as Th1, Th2, and Th17 cells. However, it
is unclear which T helper cells are important in UC. Dextran sulfate sodium (DSS)-induced
colitis is a commonly used model of UC. In this study, we induced DSS colitis in Th1
dominant (T-bet transgenic (Tg)) mice, Th2 dominant (GATA-3 Tg) mice, and Th17 dominant
(RORγt Tg) mice to elucidate the roles of T helper cell in DSS colitis. The results showed
that GATA-3 Tg mice developed the most severe DSS colitis compared with the other groups.
GATA-3 Tg mice showed a significant decreased in weight from day 1 to day 7, and an
increased high score for the disease activity index compared with the other groups.
Furthermore, GATA-3 Tg mice developed many ulcers in the colon, and many neutrophils and
macrophages were detected on day 4 after DSS treatment. Measurement of GATA-3-induced
cytokines demonstrated that IL-13 was highly expressed in the colon from DSS-induced
GATA-3 Tg mice. In conclusion, GATA-3 overexpression in T-cells and IL-13 might play
important roles in the development of DSS colitis.
dextran sulfate sodium; GATA-3; IL-13; inflammatory bowel disease; T helper cell
Cre/loxP system-mediated site-specific recombination is utilized to study gene function
in vivo. Successful conditional knockout of genes of interest is
dependent on the availability of Cre-driver mice. We produced and characterized pancreatic
β cell-specific Cre-driver mice for use in diabetes mellitus research. The gene encoding
Cre was inserted into the second exon of mouse Ins1 in a bacterial
artificial chromosome (BAC). Five founder mice were produced by microinjection of
linearized BAC Ins1-cre. The transgene was integrated between
Mafa and the telomere on chromosome 15 in one of the founders, BAC
Ins1-cre25. To investigate Cre-loxP recombination, BAC Ins1-cre25 males were crossed with
two different Cre-reporters, R26R and R26GRR females. On gross observation, reporter
signal after Cre-loxP recombination was detected exclusively in the adult pancreatic
islets in both F1 mice. Immunohistological analysis indicated that Cre-loxP
recombination-mediated reporter signal was colocalized with insulin in pancreatic islet
cells of both F1 mice, but not with glucagon. Moreover, Cre-loxP recombination
signal was already observed in the pancreatic islets at E13.5 in both F1
fetuses. Finally, we investigated ectopic Cre-loxP recombination for
Ins1, because the ortholog Ins2 is also expressed in the
brain, in addition to the pancreas. However, there was no Cre-loxP recombination-mediated
reporter signal in the brain of both F1 mice. Our data suggest that BAC
Ins1-cre25 mice are a useful Cre-driver C57BL/6N for pancreatic β cell-specific Cre-loxP
recombination, except for crossing with knock-in mice carrying floxed gene on chromosome
cre-driver mice; cre-loxP recombination; diabetes; insulin1; pancreatic β cells
Fluorescent proteins with light wavelengths within the optical window are one of the
improvements in in vivo imaging techniques. Near-infrared (NIR)
fluorescent protein (iRFP) is a stable, nontoxic protein that emits fluorescence within
the NIR optical window without the addition of exogenous substrate. However, studies
utilizing an in vivo iRFP model have not yet been published. Here, we
report the generation of transgenic iRFP mice with ubiquitous NIR fluorescence expression.
iRFP expression was observed in approximately 50% of the offspring from a matings between
iRFP transgenic and WT mice. The serum and blood cell indices and body weights of iRFP
mice were similar to those of WT mice. Red fluorescence with an excitation wavelength of
690 nm and an emission wavelength of 713 nm was detected in both newborn and adult iRFP
mice. We also detected fluorescence emission in whole organs of the iRFP mice, including
the brain, heart, liver, kidney, spleen, lung, pancreas, bone, testis, thymus, and adipose
tissue. Therefore, iRFP transgenic mice may therefore be a useful tool for various types
of in vivo imaging.
fluorescent protein; in vivo imaging; iRFP; optical window
Orexin/hypocretin neurons have a crucial role in the regulation of sleep and wakefulness. To help determine how these neurons promote wakefulness, we generated transgenic mice in which orexin neurons expressed halorhodopsin (orexin/Halo mice), an orange light-activated neuronal silencer. Slice patch-clamp recordings of orexin neurons that expressed halorhodopsin demonstrated that orange light photic illumination immediately hyperpolarized membrane potential and inhibited orexin neuron discharge in proportion to illumination intensity. Acute silencing of orexin neurons in vivo during the day (the inactive period) induced synchronization of the electroencephalogram and a reduction in amplitude of the electromyogram that is characteristic of slow-wave sleep (SWS). In contrast, orexin neuron photoinhibition was ineffective during the night (active period). Acute photoinhibition of orexin neurons during the day in orexin/Halo mice also reduced discharge of neurons in an orexin terminal field, the dorsal raphe (DR) nucleus. However, serotonergic DR neurons exhibited normal discharge rates in mice lacking orexin neurons. Thus, although usually highly dependent on orexin neuronal activity, serotonergic DR neuronal activity can be regulated appropriately in the chronic absence of orexin input. Together, these results demonstrate that acute inhibition of orexin neurons results in time-of-day-dependent induction of SWS and in reduced firing rate of neurons in an efferent projection site thought to be involved in arousal state regulation. The results presented here advance our understanding of the role of orexin neurons in the regulation of sleep/wakefulness and may be relevant to the mechanisms that underlie symptom progression in narcolepsy.
To evaluate the diagnostic value of retrospective image fusion from pelvic magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography (PET) in detecting intra-pelvic recurrence of gynecological tumor.
Thirty patients with a suspicion of recurrence of gynecological malignancy underwent inline contrast-enhanced PET/computed tomography (CT) and pelvic contrast-enhanced MRI for restaging. Diagnostic performance about the local recurrence, pelvic lymph node and bone metastasis and peritoneal lesion of PET/low-dose non-enhanced CT (PET/ldCT), PET/full-dose contrast-enhanced CT (PET/ceCT), contrast-enhanced MRI, and retrospective image fusion from PET and MRI (fused PET/MRI) were evaluated by two experienced readers. Final diagnoses were obtained by histopathological examinations, radiological imaging and clinical follow-up for at least 6 months. McNemar test was employed for statistical analysis.
Documented positive locally recurrent disease, pelvic lymph node and bone metastases, and peritoneal dissemination were present in 53.3, 26.7, 10.0, and 16.7 %, respectively. Patient-based sensitivity for detecting local recurrence, pelvic lymph node and bone metastasis and peritoneal lesion were 87.5, 87.5, 100 and 80.0 %, respectively, for fused PET/MRI, 87.5, 62.5, 66.7 and 60.0 %, respectively, for contrast-enhanced MRI, 62.5, 87.5, 66.7 and 80.0 %, respectively, for PET/ceCT, and 50.0, 87.5, 66.7 and 60.0 %, respectively, for PET/ldCT. The sensitivity of diagnosing local recurrence by fused PET/MRI was significantly better than that of PET/ldCT (p = 0.041). The patient-based sensitivity, specificity and accuracy for the detection of intra-pelvic recurrence/metastasis were 91.3, 100 and 93.3 % for fused PET/MRI, 82.6, 100 and 86.7 % for contrast-enhanced MRI, 82.6, 100 and 86.7 % for PET/ceCT and 78.3, 85.7 and 80.0 % for PET/ldCT.
Fused PET/MRI combines the individual advantages of MRI and PET, and is a valuable technique for assessment of intra-pelvic recurrence of gynecological cancers.
Fused PET/MRI; PET/CT; MRI; Restaging; Gynecological tumor