Mutated GM-CSF-based CAR-T cells targeting CD116/CD131 complexes exhibit enhanced anti-tumor effects against acute myeloid leukaemia.

OBJECTIVES: As the prognosis of relapsed/refractory (R/R) acute myeloid leukaemia (AML) remains poor, novel treatment strategies are urgently needed. Clinical trials have shown that chimeric antigen receptor (CAR)-T cells for AML are more challenging than those targeting CD19 in B-cell malignancies. We recently developed piggyBac-modified ligand-based CAR-T cells that target CD116/CD131 complexes, also known as the GM-CSF receptor (GMR), for the treatment of juvenile myelomonocytic leukaemia. This study therefore aimed to develop a novel therapeutic method for R/R AML using GMR CAR-T cells. METHODS: To further improve the efficacy of the original GMR CAR-T cells, we have developed novel GMR CAR vectors incorporating a mutated GM-CSF for the antigen-binding domain and G4S spacer. All GMR CAR-T cells were generated using a piggyBac-based gene transfer system. The anti-tumor effect of GMR CAR-T cells was tested in mouse AML xenograft models. RESULTS: Nearly 80% of the AML cells predominant in myelomonocytic leukaemia were found to express CD116. GMR CAR-T cells exhibited potent cytotoxic activities against CD116+ AML cells in vitro. Furthermore, GMR CAR-T cells incorporating a G4S spacer significantly improved long-term in vitro and in vivo anti-tumor effects. By employing a mutated GM-CSF at residue 21 (E21K), the anti-tumor effects of GMR CAR-T cells were also improved especially in long-term in vitro settings. Although GMR CAR-T cells exerted cytotoxic effects on normal monocytes, their lethality on normal neutrophils, T cells, B cells and NK cells was minimal. CONCLUSIONS: GMR CAR-T cell therapy represents a promising strategy for CD116+ R/R AML.

Bezafibrate prevents hepatic stellate cell activation and fibrogenesis in a murine steatohepatitis model, and suppresses fibrogenic response induced by transforming growth factor-beta1 in a cultured stellate cell line.

AIM: The aim of this study was to investigate the preventive actions of bezafibrate against non-alcoholic steatohepatitis (NASH), the activation of hepatic stellate cells (HSC), and fibrogenesis by using a model of NASH and an in vitro model. METHODS: Male KK-A(y)/TaJcl (KK-A(y)) mice were fed a methionine and choline-deficient (MCD) diet or a MCD diet containing bezafibrate or pioglitazone for 7 weeks, after which biochemical parameters, pathological changes, and hepatic mRNA levels were assessed. An in vitro HSC model was designed by using a previously described RI-T cell line stimulated by transforming growth factor-beta1 (TGF-beta1). RESULTS: MCD diet-fed KK-A(y) mice developed hepatic steatosis, oxidative stress, inflammation, and hepatic fibrosis. Bezafibrate markedly decreased the hepatic content of triglyceride accumulation of fatty droplets within hepatocytes, and increased the expression of hepatic fatty acid beta-oxidative genes in MCD diet-fed KK-A(y) mice. Bezafibrate markedly inhibited the increases in the plasma alanine aminotransferase level and hepatic content of thiobarbituric acid-reactive substances in this model. Moreover, it dramatically reduced hepatic inflammatory changes and fibrosis concomitantly with marked reductions in the mRNA levels for inflammatory cytokine, chemokine, and profibrogenic genes. Importantly, both bezafibrate and pioglitazone markedly reduced the mRNA levels of profibrogenic and fibrogenic genes in TGF-beta1-stimulated cells. CONCLUSION: Bezafibrate improved hepatic steatosis and potently prevented inflammation, oxidative stress, HSC activation, and fibrogenesis in the liver. Moreover, this study was the first to demonstrate that bezafibrate directly inhibits hepatic fibrogenic response induced by TGF-beta1 in vitro. Hence bezafibrate may be a new therapeutic strategy against NASH and hepatic fibrosis.

Microcalcifications of breast tissue: appearance on synchrotron radiation imaging with 6-microm resolution.

OBJECTIVE: The purpose of this study was to use synchrotron radiation imaging with 6-microm resolution to evaluate amorphous and pleomorphic breast tissue microcalcifications. CONCLUSION: Synchrotron radiation imaging depicted microcalcifications as small as 24 microm. Imaging with this technique revealed that most amorphous and pleomorphic calcifications on conventional mammograms are clusters of fine specks and that in addition to the shape or density of a speck, the distribution density of clustered specks is a factor determining the apparent shape.

Expressions and mechanical functions of alpha1-adrenoceptor subtypes in hamster ureter.

We characterized the alpha(1)-adrenoceptor subtypes in hamster ureters according to gene and protein expressions and contractile function. Real-time quantitative reverse-transcription polymerase chain reaction and immunohistochemical analysis were performed to determine mRNA levels and receptor protein expressions respectively, for alpha(1A)-, alpha(1B)- and alpha(1D)-adrenoceptors in hamster ureteral smooth muscle. alpha(1)-Adrenoceptor antagonists were tested against the phenylephrine (alpha(1)-adrenoceptor agonist)-induced contraction in isolated hamster ureteral preparations using a functional experimental approach. In the smooth muscle, relative mRNA expression levels for alpha(1a)-, alpha(1b)- and alpha(1d)-adrenoceptors were 10.7%, 1.2% and 88.1%, respectively, and protein expressions were identified for alpha(1A)- and alpha(1D)-adrenoceptors immunohistochemically. Noradrenaline and phenylephrine (alpha(1)-adrenoceptor agonist) each produced a concentration-dependent tonic contraction, their pD(2) values being 6.87+/-0.08 and 6.10+/-0.05, respectively. Prazosin (nonselective alpha(1)-adrenoceptor antagonist), silodosin (selective alpha(1A)-adrenoceptor antagonist) and BMY-7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro[4.5]decane-7,9-dione dihydrochloride) (selective alpha(1D)-adrenoceptor antagonist) competitively antagonized the phenylephrine-induced contraction (pA(2) values, 8.60+/-0.07, 9.44+/-0.06 and 5.75+/-0.07, respectively). Chloroethylclonidine (3x10(-6) mol/L or more) produced a rightward shift in the concentration-response curve for phenylephrine. Thus, in hamster ureters, alpha(1A)- and alpha(1D)-adrenoceptors were more prevalent than the alpha(1B)-adrenoceptor, with contraction being mediated mainly via alpha(1A)-adrenoceptors. If these findings hold true for humans, alpha(1A)-adrenoceptor antagonists could become useful medication for stone passage in urolithiasis patients.

Bezafibrate induces multidrug-resistance P-Glycoprotein 3 expression in cultured human hepatocytes and humanized livers of chimeric mice.

AIM AND METHODS: A decreased function of multidrug-resistance 3 P-glycoprotein (MDR3), limiting the rate of biliary phospholipid secretion, predisposes individuals to cholestasis and/or cholangitis. Fibrates induce the expression of mdr2 (homolog of human MDR3) in rodents. To investigate the effects of bezafibrate (BF) on the expression levels of MDR3 in cultured human hepatocytes and human livers, the amount of protein and subcellular localization of MDR3 was assessed in HepG2 cells treated with BF and humanized livers of BF-treated chimeric mice. RESULTS: In HepG2 cells, while treatment with BF did not increase the protein levels of MDR3, the treatment caused a redistribution of MDR3 in the bile canaliculi. In humanized livers of chimeric mice, oral administration of BF induced a large increase in the protein amount of MDR3 and its redistribution in the bile canaliculi. Moreover, the modulatory effects of BF on key factors involved in hepatic cholesterol and bile acid metabolism in human subjects were traced in the humanized livers of BF-treated chimeric mice. CONCLUSION: BF causes an induction of MDR3 expression in human livers. This provides a rationale for the beneficial role of BF in improving cholestasis and/or cholangitis associated with defective MDR3 expression and function in various types of cholestatic hepatobiliary diseases.

Bezafibrate regulates the expression and enzyme activity of 11beta-hydroxysteroid dehydrogenase type 1 in murine adipose tissue and 3T3-L1 adipocytes.

A clinically employed antihyperlipidemic drug, bezafibrate, has been characterized as a PPAR(alpha, -gamma, and -delta) pan-agonist in vitro. Recent extended trials have highlighted its antidiabetic properties in humans. However, the underlying molecular mechanism is not fully elucidated. The present study was designed to explore potential regulatory mechanisms of intracellular glucocorticoid reactivating enzyme, 11beta-HSD1 and anti-diabetic hormone, adiponectin by bezafibrate in murine adipose tissue, and cultured adipocytes. Treatment of db/db mice with bezafibrate significantly ameliorated hyperglycemia and insulin resistance, accompanied by a marked reduction of triglyceride and nonesterified fatty acids. Despite equipotent in lipid-lowering effects, another fibrate, fenofibrate, did not show such beneficial effects on glycemic control. Treatment of bezafibrate caused a marked decrease in the mRNA level of 11beta-HSD1 preferentially in adipose tissue of db/db mice (-47%, P<0.05), concomitant with a significant increase in plasma adiponectin level (+37%, P<0.01). Notably, treatment of bezafibrate caused a marked decrease in the mRNA level (-34%, P<0.01) and enzyme activity (-32%, P<0.01) of 11beta-HSD1, whereas the treatment substantially augmented the expression (+71%, P<0.01) and secretion (+27%, P<0.01) of adiponectin in 3T3-L1 adipocytes. Knockdown of 11beta-HSD1 by siRNA confirmed that 11beta-HSD1 acts as a distinct oxoreductase in adipocytes and validated the enzyme activity assays in the present study. Effects of bezafibrate on regulation of 11beta-HSD1 and adiponectin in murine adipocytes were comparable with those in thiazolidinediones. This is the first demonstration that bezafibrate directly regulates 11beta-HSD1 and adiponectin in murine adipocytes, both of which may contribute to metabolically-beneficial effects by bezafibrate.

Effects of bezafibrate, PPAR pan-agonist, and GW501516, PPARdelta agonist, on development of steatohepatitis in mice fed a methionine- and choline-deficient diet.

We evaluated the effects of bezafibrate, a peroxisome proliferator-activated receptor (PPAR) pan-agonist, and GW501516, a PPARdelta agonist, on mice fed a methionine- and choline-deficient (MCD) diet, a model of non-alcholic steatohepatitis (NASH), to investigate (a) the efficacy of bezafibrate against non-alcholic steatohepatitis and (b) the relation between non-alcholic steatohepatitis and the functional role of PPARdelta. Bezafibrate (50 or 100 mg/kg/day) and GW501516 (10 mg/kg/day) were administered by gavage once a day for 5 weeks. Hepatic lipid contents, plasma triglyceride, high density lipoprotein (HDL)-cholesterol and alanine aminotransferase (ALT) concentrations were evaluated, as were histopathological changes in the liver and hepatic mRNA expression levels. Bezafibrate and GW501516 inhibited the MCD-diet-induced elevations of hepatic triglyceride and thiobarbituric acid-reactants contents and the histopathological increases in fatty droplets within hepatocytes, liver inflammation and number of activated hepatic stellate cells. In this model, bezafibrate and GW501516 increased the levels of hepatic mRNAs associated with fatty acid beta-oxidation [acyl-CoA oxidase (ACO), carnitine palmitoyltransferase-1 (CPT-1), liver-fatty acid binding protein (L-FABP) and peroxisomal ketothiolase], and reduced the levels of those associated with inflammatory cytokines or chemokine [transforming growth factor (TGF)-beta1, interleukin (IL)-6, IL-1beta, monocyte chemoattractant protein (MCP)-1, tumor necrosis factor (TNF) alpha and nuclear factor (NF)-kappaB1]. In addition, bezafibrate characteristically reduced the elevation in the level of plasma ALT, but enhanced that in plasma adiponectin and increased the mRNA expression levels of its receptors (adiponectin receptors 1 and 2). These results suggest that (a) bezafibrate (especially) and GW501516 might improve hepatic steatosis via an improvement in fatty acid beta-oxidation and a direct prevention of inflammation, (b) treatment with a PPARdelta agonist might improve non-alcholic steatohepatitis, (c) bezafibrate may improve non-alcholic steatohepatitis via activation not only of PPARalpha but also of PPARdelta, because bezafibrate is a PPAR pan-agonist.

Characterization of cytochrome P450 expression in murine embryonic stem cell-derived hepatic tissue system.

An in vitro system for liver organogenesis from murine embryonic stem (ES) cells has been recently established. This system is expected to be applied to the development of a new drug metabolism assay system that uses ES cells as a substitute for animal experiments. The objective of this study was to elucidate the drug metabolism profiles of the murine ES cell-derived hepatic tissue system compared with those of primary cultures of murine adult and fetal hepatocytes. The expression of the genes of the cytochrome P450 (P450) family, such as Cyp2a5, Cyp2b10, Cyp2c29, Cyp2d9, Cyp3a11, and Cyp7a1, was observed in the murine ES cell-derived hepatic tissue system at 16 days and 18 days after plating (A16 and A18). To investigate the activities of these P450 family enzymes in the murine ES cell-derived hepatic tissue system at A16 and A18, testosterone metabolism in this system was analyzed. Testosterone was hydroxylated to 6beta-hydroxytestosterone (6beta-OHT), 16alpha-OHT, 2alpha-OHT, and 2beta-OHT in this system, and was not hydroxylated to 15alpha-OHT, 7alpha-OHT, and 16beta-OHT. This metabolism profile was similar to that of fetal hepatocytes and different from that of adult hepatocytes. Furthermore, pretreatment with phenobarbital resulted in a 2.5- and 2.6-fold increase in the production of 6beta-OHT and 16beta-OHT. Thus, evidence for drug metabolic activities in relation to P450s has been demonstrated in this system. These results in this system would be a stepping stone of the research on the development and differentiation to adult liver.

Molecular pathogenesis of hepatolithiasis--a type of low phospholipid-associated cholelithiasis.

Hepatolithiasis is prevalent in East Asia, including Japan, but occurs much less frequently in Western countries. Hepatolithiasis appears mostly as brown pigment stones (calcium bilirubinate stones). The disease is characterized by its intractable nature and frequent recurrence, requiring multiple endoscopic or operative interventions, in distinct contrast to gallbladder cholesterol or black pigment stones. In view of the lack of information on the pathogenesis, a multidisciplinary approach has been carried out through the Hepatolithiasis Research Group organized by the Ministry of Health, Labor and Welfare of Japan. In this review, the up-to-date data on the molecular pathogenesis of hepatolithiasis with special reference to a defect in phospholipid metabolism are introduced and discussed. Furthermore, a potential medical treatment targeting hepatic phospholipid transporters is proposed as a future therapeutic option for the disease.

Structural inhomogeneity in mammography quality control phantoms detected by refraction-enhanced synchrotron radiation imaging.

Synchrotron radiation imaging with the refraction-enhancement mode visualized structural inhomogeneities in phantoms used for image quality control of mammography. Eight phantoms were examined, all of which were manufactured in the United States and approved by the American College of Radiology as dedicated phantoms. In addition to fiber- and mass-mimicking test objects, each phantom has 5 groups of calcification specks of various sizes. Synchrotron radiation (SR) imaging was performed at Spring-8, a synchrotron radiation facility in Japan. Images were obtained with monochromatic 20-keV x-ray beams, a radiation field of 15 mm X 26 mm at a sample plane, a CCD camera with a resolution of 6 micrometers as a detector, and a sample-to-detector distance of 10 to 11 m. Two hundred and forty specks were evaluated in total in the SR images, and the surrounding area of each speck was also included. Evaluation of the images showed that 14 crack-like structures were depicted near specks, and there were 62 specks with attached void(s) or air bubble(s). Refraction-enhanced SR imaging sensitively detected structural inhomogeneities and abnormalities in phantoms which were implicitly agreed to have a homogeneous matrix and test objects without foreign substances. A possible manufacturing-dependent quality issue was identified. The effect of inhomogeneities detected by SR imaging on visual scoring of specks could not be identified in the tested phantoms; this should be assessed on images of other phantoms in a future study.

Bezafibrate stimulates canalicular localization of NBD-labeled PC in HepG2 cells by PPARalpha-mediated redistribution of ABCB4.

Fibrates, including bezafibrate (BF), upregulate the expression of ATP binding cassette protein B4 (ABCB4) through gene transcription in mice. To determine the effects of BF on the expression levels of ABCB4 and on the stimulation of biliary phosphatidylcholine (PC) transport in human HepG2 hepatoblastoma cells, mRNA and protein levels as well as subcellular localization were investigated in the cells treated with BF. The canalicular accumulation of a fluorescent PC was assessed by confocal laser scanning microscopy. Treatment with 300 micromol/l BF for 24 h increased levels of ABCB4 mRNA but not protein by up to 151%. BF caused redistribution of ABCB4 into pseudocanaliculi formed between cells. In association with this redistribution, BF accelerated the accumulation of fluorescent PC in bile canaliculi (up to 163% of that in nontreated cells). Suppression of peroxisome proliferator-activated receptor alpha (PPARalpha) expression by either a small interfering RNA duplex or morpholino antisense oligonucleotide attenuated the BF-induced redistribution of ABCB4. These findings suggest that BF may enhance the capacity of human hepatocytes to direct PC into bile canaliculi via PPARalpha-mediated redistribution of ABCB4 to the canalicular membrane. This provides a rationale for the use of BF to improve cholestasis and/or cholangitis that is attributable to hypofunction of ABCB4.

Molecular cloning and expression of HRLRRP, a novel heart-restricted leucine-rich repeat protein.

We isolated a novel leucine-rich repeat protein (LRRP) cDNA from E13 mouse embryos by the in silico approach. The cDNA encoded a protein of 274 amino acids having 7 leucine-rich repeat motifs at the center of the protein. An in vitro transcription/translation study showed that the cDNA coded for a peptide of approximately 31kDa. Northern blot analysis suggested that the mRNA of this novel LRRP was expressed only in the heart, although RT-PCR indicated slight expression in skeletal muscle as well. The transcripts of this gene and Nkx-2.5/Csx were detected in the early stage of cardiac differentiation of P19CL6 embryonal carcinoma cells treated with 1% dimethyl sulfoxide. The fusion protein made between it and GFP was detected at a high level in mitochondria and a low level in the nuclei of COS7 cells. The nuclei of the adult mouse heart were strongly stained with the antibody raised against the synthetic peptide of the protein. Therefore, we designated the gene as heart-restricted leucine-rich repeat protein (HRLRRP) and assume that mouse HRLRRP may play important roles in cardiac development and/or cardiac function.

Relationship between ligand binding and YIPP motif in the C-terminal region of human AT1 receptor.

The YIPP (tyrosine-isoleucine-proline-proline, amino acids 319-322) motif within the C-terminal part of the human AT(1) receptor is associated with angiotensin II (AII)-induced activation of the Jak-STAT pathway and phospholipase Cgamma1 phosphorylation. We report here that mutations of the YIPP motif strongly affect ligand-binding to the receptor. We analysed AT(1) receptors of the wild type (WT) and 11 mutants with a FLAG-epitope-tag within their C-terminal portion. Mutations of the "P-P" amino acid sequence of this motif decreased both AII binding and the AII-induced intracellular Ca(2+) transients. Mutant and WT receptors were expressed equally in the cell membrane and were localized within the plasma membrane. These results suggest that the "P-P" amino acid sequence within the YIPP motif is important for AII binding to the AT(1) receptor.

Heterogeneous distribution of beta-adrenoceptors and muscarinic receptors in the sinoatrial node and right atrium of the dog.

1. The pacemaker site is known to shift away from the sinoatrial (SA) node in response to autonomic stimuli. 2. To test whether the shifting of the impulse-initiation site that occurs during autonomic nerve stimulation can be explained by the spatial distributions of beta-adrenoceptor and muscarinic receptors, we obtained densities (B(max)) and dissociation constants (K((d)) for these receptors in three regions along the sulcus terminalis (the SA node itself and regions superior and inferior to it) and a region of the right atrial appendage in the dog. 3. The Bmax values for [(125)I]-iodocyanopindolol binding to beta-adrenoceptors were not different among the four regions. The Bmax value for [(3)H]-quinuclidinyl benzilate binding to muscarinic receptors was significantly higher in the SA node area than in any other region (P < 0.01), although there was no difference among the other three regions. 4. For each receptor, K(d) values were similar among the four regions. 5. These results suggest that spatial variations in the densities of beta-adrenoceptors and muscarinic receptors are not important for shifting the impulse-initiation site and that other factors, such as non-uniform innervation by autonomic nerve fibres, may be mainly responsible for the pacemaker shift induced by autonomic nerve stimulation.