Identification of TEKTIN1-expressing multiciliated cells during spontaneous differentiation of non-human primate embryonic stem cells

Tektins are a group of microtubule-stabilizing proteins necessary for cilia and flagella assembly. TEKTIN1 (TEKT1) is used as a sperm marker for monitoring germ cell differentiation in embryonic stem (ES) and induced pluripotent stem (iPS) cells. Although upregulation of TEKT1 has been reported during spontaneous differentiation of ES and iPS cells, it is unclear which cells express TEKT1. To identify TEKT1-expressing cells, we established an ES cell line derived from cynomolgus monkeys (Macaca fascicularis), which expresses Venus controlled by the TEKT1 promoter. Venus expression was detected at 5 weeks of differentiation on the surface of the embryoid body (EB), and it gradually increased with the concomitant formation of a leash-like structure at the EB periphery. Motile cilia were observed on the surface of the Venus-positive leash-like structure after 8 weeks of differentiation. The expression of cilia markers as well as TEKT1-5 and 9 + 2 microtubule structures, which are characteristic of motile cilia, were detected in Venus-positive cells. These results demonstrated that TEKT1-expressing cells are multiciliated epithelial-like cells that form a leash-like structure during the spontaneous differentiation of ES and iPS cells. These findings will provide a new research strategy for studying cilia biology, including ciliogenesis and ciliopathies.

Establishment of testicular and ovarian cell lines from Honmoroko (Gnathopogon caerulescens)

We succeeded to establish cell lines from endemic fish species Honmoroko Gnathopogon caerulescens, which inhabits Lake Biwa, the third oldest lake in the world. Two cell lines designated as RMT1 and RMO1 were established from testis and ovary of G. caerulescens, respectively. These cell lines were initially cultured in Leibovitz's L-15 medium supplemented with fetal bovine serum (FBS), fish embryo extract, epidermal growth factor, and basic fibroblast growth factor. Further addition of forskolin and β-mercaptoethanol was required to establish and maintain these cell lines for more than 60 passages. RMT1 and RMO1 cells showed fibroblast- and epithelial-like morphology, respectively. From immunocytochemical staining and gene expression patterns, RMT1 cells showed a characteristic of testicular Sertoli cells and RMO1 cells did that of ovarian theca cells. Both RMT1 and RMO1 cells multiplied well in the medium supplemented with 10 % FBS at 28 °C and their minimum population doubling times were 24.4 and 28.8 h, respectively. At the 45th passage, most of the RMT1 and RMO1 cells had a hyperploid set of chromosomes (67.3 and 96.1 %, respectively). Cells with normal diploid chromosome set were not observed. RMT1 cells were transfected with an enhanced green fluorescent protein (EGFP) expression vector and human elongation factor 1 α promoter worked efficiently to express EGFP. In addition, EGFP-expressing cell lines were also established, suggesting that the cell lines could be utilized as an in vitro monitor system (biosensor) for the evaluation of endocrine disruptors which might affect gonadal function.

Direct binding of gangliosides to Helicobacter pylori vacuolating cytotoxin (VacA) neutralizes its toxin activity

Gangliosides are target receptors for bacterial entry, yet those present in human milk exhibit a protective role against bacterial infection. Here, we show that treatment with ganglioside mixture at a concentration of 100 microg/mL resulted in significant inhibition of the vacuole formation activity of Helicobacter pylori vacuolating cytotoxin (VacA) in gastric epithelial cancer AZ-521 cells. All gangliosides (GM1, GM2, GM3, GD1a, GD1b, GD3 and GT1b) examined showed good neutralizing capacity against VacA. A pull-down assay was performed using lyso-GM1 coupled to Sepharose as the tagged polysaccharide polymer to capture VacA from H. pylori culture supernatant. GM1-VacA complexes were successfully precipitated, suggesting that GM1 binds directly to VacA. The hydrodynamic binding of lyso-GM1 and VacA measured by fluorescence correlation spectroscopy had a K(d) value of 190 nM. VacA also bound to lyso-GM1 at pH 2 corresponding to the physiological pH of human stomach. Collectively, these results showed that direct binding of H. pylori VacA to free gangliosides neutralizes the toxin activity of VacA. These findings offer an alternative insight into the role of gangliosides in VacA toxicity and the pathogenesis of H. pylori.

Establishment from mouse growth cartilage of clonal cell lines with responsiveness to parathyroid hormone, alkaline phosphatase activity, and ability to produce an endothelial cell growth inhibitor

Three clonal cell lines with differences in responsiveness to parathyroid hormone (PTH), alkaline phosphatase activity, and ability to produce an endothelial cell growth inhibitor(s) during more than 3 years, more than 58 passages, in culture were established from growth cartilage (GC) of mouse ribs. In sparse cultures the three clonal cell lines, MGC/T1.4, MGC/T1.17, and MGC/T1.18, all showed fibroblast-like morphology. However, as they became confluent, MGC/T1.4 cells became polygonal and then multilayered. MGC/T1.18 cells also became polygonal, but showed contact inhibition. MGC/T1.17 cells remained fibroblastic in confluent cultures and formed nodules when cultured for more than 7 days after they became confluent. These nodules calcified in the presence of beta-glycerophosphate. Glycosaminoglycan (GAG) synthesis in the parent uncloned line, MGC/T1 cells, at early passages was about 50-75% of that of primary cultures of mouse GC cells. The GAG syntheses in the three clonal lines were much lower than that of primary cultures of GC cells. Moreover, the sizes of proteoglycan monomers synthesized by these cells were not the same as that of cartilage-specific proteoglycan. The three clonal lines mainly synthesized type I collagen. PTH increased the intracellular cyclic AMP level in MGC/T1, MGC/T1.4, T1.17, and T1.18 cells: their maximal levels, observed after 2 minutes, were, respectively, about 160, 150, 70, and 200 times that of controls. The activity of alkaline phosphatase in MGC/T1.17 cells was higher than that in primary cultures of mouse GC cells, whereas those in MGC/T1 and T1.4 cells were comparable with that of GC cells, and that in MGC/T1.18 was lower. The three clonal lines, and especially MGC/T1.4, secreted a heat-stable, nondializable growth inhibitor(s) of endothelial cells into the culture medium. Because of their different properties, these cell lines should be useful for studies on endochondral ossification, the actions of PTH on skeletal cells, and anti-angiogenesis factors.

Differential effects of 1 alpha,25-dihydroxycholecalciferol and 24R,25-dihydroxycholecalciferol on the proliferation and the differentiated phenotype of rabbit costal chondrocytes in culture

1 alpha,25-Dihydroxycholecalciferol [1,25-(OH)2D3] stimulated the proliferation and DNA synthesis of rabbit costal growth cartilage cells in the logarithmic growth phase in culture. The stimulatory effects of 1,25-(OH)2D3 were observable at a concentration of 10(-10) M and maximal at a concentration of 10(-8) M. On the other hand, 1,25-(OH)2D3 inhibited their expression of the cartilage phenotype, as judged morphologically, histochemically, and biochemically by a decrease in glycosaminoglycan (GAG) synthesis. The inhibition of GAG synthesis was also dose dependent and observable at a concentration of 10(-10) M. 1,25-(OH)2D3 also stimulated the proliferation of resting cartilage cells and inhibited their GAG synthesis, but its effects on these cells were less than those on growth cartilage cells, suggesting that 1,25-(OH)2D3 acts more specifically on growth cartilage cells than on resting cartilage cells. 1,25-(OH)2D3 had no effect on either DNA synthesis or GAG synthesis of growth cartilage cells in confluent cultures. 24R,25-Dihydroxycholecalciferol [24,25-(OH)2D3] had no effect on proliferation, DNA synthesis, or GAG synthesis of growth cartilage cells in the logarithmic growth phase. However, 24,25-(OH)2D3 had no effect on DNA synthesis of these cells in confluent cultures, but stimulated their expression of the cartilage phenotype. The stimulatory effect was dose dependent and maximal at 10(-7) M. Since chondrocytes express their differentiated phenotype as they become confluent in culture, these results suggest that 1,25-(OH)2D3 stimulates the growth of rapidly proliferating chondrocytes with a poorly differentiated phenotype and suppresses their expression of the cartilage phenotype, while 24,25-(OH)2D3 stimulates expression of the differentiated phenotype of highly differentiated chondrocytes.

Chondrocytes dedifferentiated by serial monolayer culture form cartilage nodules in nude mice

Chondrocytes isolated from rabbit costal growth cartilage grew rapidly and expressed the differentiated phenotypes of chondrocytes in primary monolayer cultures. They had a typical polygonal shape, synthesized glycosaminoglycan (GAG) actively and responded to parathyroid hormone (PTH). However, during successive passages they lost the abilities to proliferate and express differentiated phenotypes. They changed from polygonal to fibroblast-like morphology during the third to fourth passage. Their GAG synthesis rapidly decreased in the 4th passage to 10% of that during primary culture. The increase in GAG synthesis and intracellular cyclic AMP induced by PTH also became smaller and were lost in the 4th passage. From these findings, cells in the 4th passage appeared to be dedifferentiated. However, subcutaneous transplantation of cells at the 5th passage into nude mice resulted in the formation of cartilaginous nodules. Moreover, cells isolated from these nodules and cultured in vitro had a typical polygonal shape and synthesized GAG actively and PTH increased their metachromatic matrix and intracellular cyclic AMP level. These findings suggest that chondrocytes that appear to be dedifferentiated after serial passages still have the potential to differentiate.

A factor in conditioned medium of rabbit costal chondrocytes inhibits the proliferation of cultured endothelial cells and angiogenesis induced by B16 melanoma: its relation with cartilage-derived anti-tumor factor (CATF)

Serum-free medium conditioned by exposure to rabbit costal chondrocytes in culture inhibited the proliferation and DNA synthesis of bovine pulmonary endothelial cells in culture. The factor in conditioned medium did not inhibit DNA synthesis in B16 melanoma cells, L1210 cells or 3T3 fibroblasts in culture, but it inhibited angiogenesis in the chorioallantoic membrane of chick embryos induced by B16 melanoma and growth of the tumor transplanted onto the membrane. These findings strongly suggest that rabbit costal chondrocytes produce an anti-angiogenesis factor that is similar to cartilage-derived anti-tumor factor (CATF).

The effect of parathyroid hormone (1-34) on cyclic AMP level, ornithine decarboxylase activity, and glycosaminoglycan synthesis of chondrocytes from mandibular condylar cartilage, nasal septal cartilage, and spheno-occipital synchondrosis in culture

Previously, we reported methods for isolating chondrocytes from the craniofacial complex and their culture in vitro. The response of these chondrocyte cultures to bovine parathyroid hormone (1-34) (PTH) has now been investigated. PTH stimulated glycosaminoglycan (GAG) synthesis, a characteristic of the cartilage phenotype in cultured chondrocytes isolated from mandibular condylar cartilage (MCC), nasal septal cartilage (NSC), and spheno-occipital synchondrosis (SOS). These stimulations of GAG synthesis by PTH were dose-dependent. PTH also increased accumulation of cyclic AMP (cAMP) and the activity of ornithine decarboxylase (ODC), a rate-limiting enzyme in polyamine biosynthesis. However, PTH did not stimulate DNA synthesis. The increases in the cAMP level, ODC activity, and GAG synthesis after addition of PTH (10(-7) mol/L) were greatest in MCC-chondrocytes and least in NSC-chondrocytes. The difference in the responses to PTH of these three types of chondrocytes may reflect differences of the characteristics of these cells in vivo.

Cartilage-derived anti-tumor factor (CATF) inhibits the proliferation of endothelial cells in culture

Previous studies showed that a cartilage-derived anti-tumor factor (CATF), which was extracted from bovine cartilage with 1 M guanidine hydrochloride, inhibited the growth of solid sarcoma 180, but not the growth of ascites tumors of sarcoma 180 [Suzuki, F. et al. Jpn. J. Bone Metab., 2, 231-235 (1984)]. This study showed that CATF inhibited the proliferation and DNA synthesis of endothelial cells isolated from bovine pulmonary artery, but not the proliferations of sarcoma 180, L1210 and L cells. These results suggest that CATF has anti-angiogenic properties, thereby inhibiting the growth of solid tumors.

Effects of synthetic analogs and fragments of bovine parathyroid hormone on adenosine 3',5'-monophosphate level, ornithine decarboxylase activity, and glycosaminoglycan synthesis in rabbit costal chondrocytes in culture: structure-activity relations

Previously, we demonstrated that PTH increases the level of cAMP, the activity of ornithine decarboxylase (ODC; EC 4.1.1.17; which is a rate-limiting enzyme in polyamine biosynthesis), and glycosaminoglycan (GAG) synthesis (which is characteristic of the chondrocyte phenotype) in rabbit costal chondrocytes in culture. These studies suggested that the accumulation of cAMP and the induction of ODC by PTH are good markers of the differentiated phenotype of cultured chondrocytes. In the present study, the biological effects of a series of bovine PTH (bPTH) fragments and analogs on these three parameters of PTH action were examined. bPTH-(1-34), [Nle8,Nle18,Tyr34]bPTH-(1-34) amide and bPTH-(1-27) amide increased cAMP levels, ODC activity, and GAG synthesis in a dose-dependent manner over the concentration range of 10(-9)-10(-5) M. The order of decreasing potency was: bPTH-(1-34), [Nle8,Nle18,Tyr34]bPTH-(1-34) amide, and bPTH-(1-27) amide. On the other hand, [Nle8,Nle18,Tyr34]bPTH-(3-34) amide, bPTH-(5-27) amide, and [Tyr34]bPTH-(20-34) amide failed to increase cAMP levels, ODC activity, or GAG synthesis when present in concentrations up to 10(-5) M. However, [Nle8,Nle18,Tyr34]bPTH-(3-34) amide, bPTH-(5-27) amide, and [Tyr34]bPTH-(20-34) amide inhibited bPTH-(1-34)-stimulated increases in cAMP and ODC activity. These results partially define the principal structural determinants within the PTH molecule required for biological activity and expression of the differentiated phenotype of chondrocytes.

Cytoskeleton and differentiation: effects of cytochalasin B and colchicine on expression of the differentiated phenotype of rabbit costal chondrocytes in culture

Cytochalasin B changed the shape of cultured rabbit costal chondrocytes from polygonal to nearly spherical and stimulated glycosaminoglycan synthesis, which is a differentiated phenotype of chondrocytes, whereas colchicine changed them from polygonal to flattened and inhibited glycosaminoglycan synthesis. These morphological changes occurred parallel with the changes in glycosaminoglycan synthesis. Induction of ornithine decarboxylase by parathyroid hormone, which is a good marker of differentiated chondrocytes, was markedly potentiated in the spherical cells which had been pretreated with cytochalasin B, whereas pretreatment with colchicine inhibited the induction of the enzyme. Both cytochalasin B and colchicine inhibited DNA synthesis. The inhibitions were observed after the appearance of changes in the morphology of the cells and glycosaminoglycan synthesis. These findings suggest that intactness of microtubules and disruption of microfilaments are involved in regulating the expression of the differentiated phenotype of chondrocytes in culture.

[The retrospective observation of the cervical smear of the cervical squamous cell cancerous patients]

This study is aimed cytologically to observe the development of the squamous cell carcinoma and to study the role of the cervical smear in the diagnosis of the cervical cancer. The cervical squamous cell cancerous patients who have the past history of the cervical smear for more than six months were selected and their cervical smears were analyzed retrospectively. The result of the cervical smear were classified into three: Negative, suspicious and positive for the statistical purposes. Each patient's cervical smears were arranged spectroscopically by the length of the elapsed time from the date of the smear to that of the diagnosis. The result of the cervical smear, the length of the elapsed time and the progression of the carcinoma were observed. It was suggested cytologically that the cervical squamous cell carcinoma will grow more slowly. This result showed us the possibility of the extension of the cytologic screening interval for the diagnosis of the cervical cancer. But the cytological analysis of the individual cervical smears suggested us that there are some problems about the confidence of the cytological diagnosis of the cervical cancer. It is our impression that the conservative screening interval will be better to keep the high diagnostic accuracy.

[Production of 61Cu, 62Zn by alpha and 3He particle bombardment of natural nickel (author's transl)]

The optimum irradiation conditions were investigated for the production of 61Cu and 62Zn by alpha and 3He particle bombardment of natural nickel. Formation cross sections and thick-target yields were obtained for reaction products in the energy range of 10 to 40 MeV. For the production of 61Cu and 62Zn, the alpha particle bombardment was found superior to the 3He particle bombardment in so far as the yield was concerned. When the incident alpha energy of 21 MeV was chosen, after 2.4 hours of cooling, 2.1 mCi/muA.h of 61Cu could be produced with less than 1% of 60Cu contamination. For the production of 62Zn, when the incident alpha energy of 35 MeV and the target thickness of 57 mg /cm2 were chosen, 97.5 muCi/muA.h of 62Zn could be produced. Radiochemical purity of 62Zn was the highest at 12 hours after the end of bombardment.

Quantitation of berberine chloride in human urine by use of selected ion monitoring in the field desorption mode

A method is described for the microdetermination of berberine chloride in human urine by a field desorption mass spectrometry selected ion monitoring system using a deuterium labelled analogue of berberine chloride as an internal standard. Prior to the quantitation of berberine in human urine, the fundamental problems related to field desorption selected ion monitoring, such as quality of emitters, amounts of sample loading, and the programming rate of the emitter current, were statistically investigated in detail. Berberine chloride can be determined in a concentration of 10 ng ml-1 in human urine by the method described. The analytical results were compared with those from gas chromatography mass spectrometry selected ion monitoring in the chemical ionization mode suggesting that the reliability of field desorption selected ion monitoring may be almost equivalent to that of gas chromatography chemical ionization selected ion monitoring.

Quantitative analysis of berberine in urine samples by chemical ionization mass fragmentography

A highly specific and sensitive method has been developed for the quantitative determination of berberine in human urine. In order to carry out the microdetermination of berberine by chemical ionization mass fragmentography, berberine was reduced with sodium borohydride in methanol to tetrahydroberberine and subjected to gas chromatography-mass spectrometry. Berberine concentrations as low as 1 ng/ml urine can be measured by this method, with [2H3]berberine chloride as an internal standard.