Effect of hyaluronan tetrasaccharides on epidermal differentiation in normal human epidermal keratinocytes.

OBJECTIVE: Hyaluronan (HA) plays a role in keratinocyte proliferation and differentiation. In addition, HA has been shown to have different biological activities depending on its molecular weight. It has been reported that HA-mediated CD44 activation regulates keratinocyte differentiation. Therefore, the aim of this study was to investigate the influence of HA tetrasaccharides (HA4) on the regulation of keratinocyte differentiation, CD44 gene expression and CD44-phosphorylated protein in human keratinocytes, and compare HA4 with high molecular weight HA. METHODS: Normal human epidermal keratinocytes (NHEKs) were treated at doses of 1 µg mL(-1) HA or HA oligosaccharides (HA4). After treatment, cell viability was checked using an MTT (3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Each differentiation marker and CD44 mRNA expression was detected by real-time PCR. Each differentiation marker and CD44-phosphorylated protein was assessed by Western blotting. RESULTS: Hyaluronan and HA4 showed no cytotoxicity up to a dose of 1 µg mL(-1) . On day 3 after HA4 treatment, each differentiation marker mRNA and K10 protein level was higher than that of the control. On day 9, late differentiation marker mRNA and protein levels were increased with HA and HA4 treatment. In addition, HA4 treatment increased the expression of CD44 mRNA, CD44-phosphorylated protein and intracellular calcium concentrations. HA4 enhanced keratinocyte differentiation and increased CD44-phosphorylated protein levels. CONCLUSION: HA4 may induce epidermal differentiation through phosphorylation of CD44.

Application of glucosylceramide-based liposomes increased the ceramide content in a three-dimensional cultured skin epidermis.

Ceramide is an intercellular lipid of the stratum corneum and is one of the most important components of the epidermal permeability barrier. Glucosylceramide (GlcCer), a ceramide precursor, was applied to three-dimensional skin culture to regulate ceramide. GlcCer/dimyristoylphosphatidylcholine (DMPC) = 4/4 (molar ratio and GlcCer/DMPC/dimyristoylphosphatidylglycerol (DMPG) = 4/4/1(molar ratio) liposomes were prepared by the thin-layer method. The particle diameters of GlcCer/DMPC and GlcCer/DMPC/DMPG liposomes were 124.0 ± 0.6 and 119.3 ± 18.9 nm, and the zeta potentials were 1.3 ± 0.3 and -19.9 ± 0.3 mV, respectively. Stability of these GlcCer liposomes was measured by transmission light scattering. Transmission light scattering of neutrally charged GlcCer (GlcCer/DMPC) liposomes increased in a time dependent manner. In contrast, negatively charged GlcCer (GlcCer/DMPC/DMPG) liposomes were not changed. ß-Glucocerebrosidase activity was measured in a cultured human skin model. Results confirmed that the cultured human skin model has ß-glucocerebrosidase activity. GlcCer/DMPC/DMPG liposomes were applied to the three-dimensional cultured human skin model, and ceramide NS, NP, AS, and AP were extracted from it. The various extracted ceramides were separated by high-performance thin-layer chromatography and quantified by a densitometer. The amount of ceramide AS only in the cultured skin model was significantly higher with the application of GlcCer-based liposomes than that of the nonapplication group, and was also dose dependent. Thus, GlcCer-based liposomes are useful for enriching the ceramide AS levels in a three-dimensional cultured skin model.

Increase in ceramide level after application of various sizes of sphingomyelin liposomes to a cultured human skin model.

Sphingomyelin-based liposomes (SPM-L) that were sized (or not) by extrusion through a filter with pores of 100, 200, or 400 nm were applied to a three-dimensional cultured human skin model in order to evaluate which size of SPM-L was most effective at increasing its ceramide level. The diameters of the SPM-L in PBS were 102.7, 181.0, 224.0, and 380.1 nm. The diameters of the liposomes in the culture medium were 117.5, 199.2, 242.1, and 749.8 nm. The diameter of the small liposomes (<200 nm in diameter) did not change much, at least for 7 days. SPM-L in saline or culture medium were applied to the basal layer side or stratum corneum side of the cultured skin model, and ceramide II, III, V, and VI were then extracted from it. The extracted ceramide molecules were separated by HPTLC, and the concentration of each type of ceramide was quantified using a densitometer. When the small SPM-L (110 or 190 nm in diameter) were applied to the basal layer side, the levels of ceramide III and V were increased. When they were applied to the stratum corneum side, the levels of ceramide II, III, V, and VI were significantly increased compared to those of the PBS group, especially after the application of the small SPM-L (110 nm in diameter). Thus, the application of small SPM-L was useful for increasing the ceramide II, III, V, and VI levels of a cultured human skin model.

A novel macrocyclic spermine alkaloid from Incarvillea sinensis.

A novel macrocyclic spermine alkaloid incasine C' (1), along with a known compound incasine C (2), were isolated from the whole plants of Incarvillea sinensis, and their structures were elucidated on the basis of chemical and spectroscopic evidence.

Administration of osteocalcin accelerates orthodontic tooth movement induced by a closed coil spring in rats.

The effect of local administration of osteocalcin (OC) on experimental tooth movement was examined in the rat. The maxillary first molar was first moved mesially with an initial tipping force of 30 g with a closed-coil spring anchored to the incisor for 10 days (n = 48). Three experimental groups (n = 8) were injected with purified rat OC at doses of 0.1, 1, and 10 micrograms, respectively. The injection into the palatal bifurcation site of the first molar was repeated daily. The control groups (n = 8) were injected with rat serum albumin (10 micrograms), phosphate buffered saline (PBS), or were not injected. Tooth movement was evaluated daily by measuring the inter-cuspal distance between the first and the second molars on a precise plaster model. The cumulative tooth movement (mm) in the 1-microgram OC-injected groups was significantly more than that in all of the control groups on day 9. The rate of tooth movement (mm/day) showed periodical elevation, with high values on days 1, 4, 7, and 9. Acceleration of tooth movement by OC was significant in the early experimental period. Subsequently, acceleration of early tooth movement by OC was histologically evaluated (n = 40). Each of four animals from the control (PBS, n = 20) and the experimental (1 microgram OC, n = 20) groups was killed daily up to 5 days. A significantly larger number of osteoclasts accumulated on the mesial alveolar bone surface in the 1-microgram OC-injected group on day 3 than that observed in control group. These results suggest that administration of OC accelerates orthodontic tooth movement due to enhancement of osteoclastogenesis on the pressure side, primarily in the early experimental period.

Inhibitory activities of (-)-epigallocatechin-3-O-gallate against topoisomerases I and II.

The substitution of gallic acid at the 3 position of (-)-epigallocatechin-3-O-gallate (EGCG) increased the inhibition against topoisomerase I from calf thymus gland and topoisomerase II from human placenta, and the substitution of a hydroxyl group at the 3' position increased the inhibition against the topoisomerase I. These results suggested that the 3 and 3' positions of the EGCG molecule play important roles in the process of inhibition of topoisomerases I and II. EGCG showed strong inhibition against topoisomerases I from wheat germ, calf thymus gland and Vero cells, and showed weak or no inhibition against topoisomerases I from carcinoma cells such as A549, HeLa and COLO 201 cells. EGCG differentially inhibited the topoisomerases I from different sources.

Accumulation of medium chain acyl-CoAs during beta-oxidation of long chain fatty acid by isolated peroxisomes from rat liver.

We have reported fatty alcohol synthesis accompanied by chain elongation in liver peroxisomes (Biochim. Biophys. Acta, 1346, 38 (1997)). In the present experiment, we studied what kind of acyl-CoA(s) destined to be utilized as primer for fatty alcohol synthesis accumulate(s) during peroxisomal beta-oxidation. Peroxisomes were prepared from rat liver treated with clofibrate, a peroxisome proliferator, and incubated with [U-14C]palmitate, in order to investigate acyl-CoAs after beta-oxidation. At 1 mM concentration, MgATP activated beta-oxidation, but inhibited beta-oxidation at concentrations higher than 1 mM. After incubation of peroxisomes with palmitate, various acyl-CoAs were formed. Among medium-chain labelled acyl-CoAs, octanoyl-CoA was mainly detected. These results suggest that octanoyl-CoA accumulates during beta-oxidation of palmitate. When peroxisomes were incubated with [9,10-(3)H]palmitate and [9,10-(3)H]stearate, among medium-chain acyl-CoAs, octanoyl-CoA and decanoyl-CoA were primarily detected, respectively, suggesting the occurrence of at least 4 cycles of beta-oxidation of both fatty acids by peroxisomes.

Expression and localization of MGP in rat tooth cementum.

Tooth cementum, a calcified hard tissue covering the root surfaces, is an important component connecting the teeth to the collagenous fibres of the periodontal ligament. Although the overall composition of cementum may closely resemble that of bone, each part has not been fully characterized. Here, the localization of the matrix gamma-carboxyglutamic acid (Gla) protein (MGP), one of the major Gla-containing proteins in the body, in cementum was investigated using immunohistochemistry and in situ hybridization. (1) Strong MGP antigenicity was observed in the acellular cementum, but was only moderate in the cellular cementum; (2) polygonal periodontal ligament cells facing the acellular cementum and the uncalcified cellular cementum expressed MGP mRNA, indicating that these cells produced MGP and deposited it on the cementum; (3) MGP accumulated at the junction between the uncalcified and calcified cellular cementum; and (4) the distribution pattern of MGP antigenicity resembled that of osteopontin. As one function of MGP could be as a negative regulator for mineral apposition, the expression of MGP in the cells adjacent to the cementum may be important to prevent hyperapposition of minerals.

Structure-antinociceptive activity studies of incarvillateine, a monoterpene alkaloid from Incarvillea sinensis.

Incarvillateine (1), a new monoterpene alkaloid carrying a characteristic cyclobutane ring, has been found to show significant antinociceptive activity in a formalin-induced pain model in mice. To investigate the correlation between its structure and antinociceptive activity, and especially to study whether a cyclobutane ring is necessary or not for expression of activity, we evaluated the antinociceptive activity of two constructive units of incarvillateine, such as a monoterpene unit (incarvilline, 3) and a phenylpropanoid unit (ferulic acid, 2) in the formalin test, and compared activity of the units with that of incarvillateine. Furthermore, in order to obtain more information about the structure-activity relationships, monoterpene alkaloid derivatives, such as incarvine C (5, a precursor of incarvillateine), incarvine A (4, an ester compound comprised of two monoterpene alkaloids and a monoterpene) and 3,3'-demethoxy-4,4'-dehydroxyincarvillateine (6, a synthetic new compound), were examined. The antinociceptive effect of 3,3'-demethoxy-4,4'-dehydroxyincarvillateine was equal to that of incarvillateine. Meanwhile, the other compounds exhibited no or weak activity. These results suggested that the cyclobutane moiety of incarvillateine plays an important role in expression of antinociceptive action.

An autopsy case of giant cell myocarditis probably due to a non-steroidal anti-inflammatory drug.

An autopsy case of giant cell myocarditis (GCM) in a 74-year-old woman is presented. She suffered from hepatic dysfunction, skin eruption and disseminated intravascular coagulation due to the side-effects of a non-steroidal anti-inflammatory drug. After admission, heart failure progressed rapidly, and the patient died suddenly. At autopsy, her heart was slightly enlarged and the heart muscle was thickened with many small whitish nodules. She was diagnosed with GCM because of the infiltration of multinuclear giant cells, histiocytes, eosinophils and lymphocytes into the heart. We did not find any similar lesions in any other organs. Giant cell myocarditis, the etiology of which is not defined, is a rare disease with unfavorable prognosis. This case suggests the possibility of drug-induced GCM.

Force-induced osteoclast apoptosis in vivo is accompanied by elevation in transforming growth factor beta and osteoprotegerin expression.

The mechanism controlling the disappearance of osteoclasts from bone surfaces after bone resorption in vivo is largely unknown. This is because there is no suitable experimental system to trace the final fate of osteoclasts. Here, we used an experimental model of tooth movement in rats to show that preexisting osteoclasts disappeared from the bone surface through apoptosis during a force-induced rapid shift from bone resorption to formation. On the distal alveolar bone surface of the maxillary molar in growing rats, many mature osteoclasts were present. When light tensional force was applied to the bone surface through an orthodontic appliance, these preexisting osteoclasts gradually disappeared. One day after the application of force, about 24% of the osteoclasts exhibited apoptotic morphology and the proportion of apoptotic cells was increased to 41% by day 2, then decreased afterward. These changes were undetectable on the control distal alveolar bone surface, which is free from tensional force. As shown by in situ hybridization, a marked increase in transforming growth factor beta1 (TGF-beta1) and osteoprotegerin (OPG) messenger RNA (mRNA) was observed in the stretched cells on the tensioned distal bone surface, simultaneously with the loss of osteoclasts. Both of these factors are known to have a negative effect on osteoclast recruitment and survival. As early as 2 days after force application, some of these stretched cells were identified as cuboidal osteoblasts showing intense signals for both factors. Our data suggest there may be a sequential link in tensional force applied on the bone lining cells, up-regulation of TGF-beta1/OPG, and disappearance of osteoclasts.

Control engineering and electromyographic kinesiology analyses of normal human gait.

In this study, we analyzed the electrical activity patterns of the antagonistic bi-articular and mono-articular muscles of both legs during normal gait cycles, in terms of electromyographic (EMG) kinesiology and control engineering. For control engineering analyses, we utilized a mechanical two-joint link model equipped with antagonistic pairs of bi-articular and mono-articular muscles. It was confirmed that the coordinated activity pattern, in which the bi-articular muscles of the rectus femoris (Rf) and the medial hamstrings (Mh) showed criss-cross EMG patterns, and the mono-articular muscles of the gluteus maximus and the vastus medialis showed sustained activities during the early stance phase in the gait cycle, contributed to the output force control and the output force direction control. Reversal of Rf and Mh activities was responsible for changes in the output force direction during the heel contact period. The results obtained here strongly highlight the importance of and necessity for control engineering evaluation of coordinated muscle activities of bi-articular and mono-articular antagonistic muscles for analyses not only of gait but also of sports injuries.

Isolated palmar dislocation of the fifth carpometacarpal joint diagnosed by stress X-rays.

Isolated palmar ulnar dislocation of the fifth carpometacarpal (CMC) joint is a rare injury which often yields only subtle radiographic findings that may be easily overlooked, especially when there is no associated fracture. We reported a case of an isolated palmar dislocation of the fifth CMC joint, diagnosed correctly by means of simple stress X-rays (traction and axial compression stress views). This method proved to be useful and needs no special equipment.

A common downstream signaling activity of osteoclast survival factors that prevent nitric oxide-promoted osteoclast apoptosis.

Treatment with NO-releaser NOC18 significantly promoted apoptosis in murine osteoclast-like cells, with a transient increase in caspase-3-like protease activity. In contrast, the apoptosis was protected against by caspase inhibitors, most efficiently with the broadly acting caspase specific inhibitor z-Asp-CH2-DCB, indicating involvement of multiple caspases in progression of the apoptosis. Among osteoclast survival factors examined, calcitonin completely protected against morphologically defined-apoptosis and the increase of caspase-3-like protease activity. The effect of calcitonin was mimicked by treatment of cells with (Bu)2cAMP and forskolin, and abolished by protein kinase-A inhibitor H-89. Independently from the PKA activation, colony stimulating factor-1, interleukin-1beta and the receptor activator of NF-kappaB ligand also protected against the apoptosis but were less effective than calcitonin. All survival factors investigated inhibited conversion of procaspases-3 and -9 to their mature forms in the cells. Thus, downstream antiapoptotic signaling activity from each factor overlapped in inhibition of caspases. However, how this was attained seemed to be different from each other. Typically, only colony stimulating factor-1 up-regulated expression of endogenous caspase inhibitor protein, X-linked inhibitor of apoptosis (XIAP), in the osteoclast-like cells.

Changes in isoprenoid lipid synthesis by gemfibrozil and clofibric acid in rat hepatocytes.

We studied whether gemfibrozil and clofibric acid alter isoprenoid lipid synthesis in rat hepatocytes. After incubation of the cells with the agent for 74 hr, [(14)C]acetate or [(3)H]mevalonate was added, and the cells were further incubated for 4 hr. Gemfibrozil and clofibric acid increased ubiquinone synthesis from [(14)C]acetate and [(3)H]mevalonate. The effect of gemfibrozil was greater than that of clofibric acid. Also, gemfibrozil decreased dolichol synthesis from [(14)C]acetate and [(3)H]mevalonate. However, clofibric acid increased dolichol synthesis from [(3)H]mevalonate. Gemfibrozil decreased cholesterol synthesis from [(14)C]acetate and [(3)H]mevalonate. Clofibric acid decreased cholesterol synthesis from [(14)C]acetate, but did not affect synthesis from [(3)H]mevalonate. These results suggest that both agents, at different rates, activate the synthetic pathway of ubiquinone, at least from mevalonate. Gemfibrozil may inhibit the synthetic pathway of dolichol, at least from mevalonate. Contrary to gemfibrozil, clofibric acid may activate the synthetic pathway of dolichol from mevalonate. Gemfibrozil may inhibit the synthetic pathway of cholesterol from mevalonate in addition to the pathway from acetate to mevalonate inhibited by both agents.

Strong antinociceptive effect of incarvillateine, a novel monoterpene alkaloid from Incarvillea sinensis.

Incarvillea sinensis is a wild plant distributed in northern China. The dried whole plant has been traditionally used to treat rheumatism and relieve pain as an ancient Chinese crude drug. To investigate its antinociceptive activity, we evaluated several fractions derived from the methanolic extract of Incarvillea sinensis in the formalin-induced pain model in mice. Incarvillateine, a novel monoterpene alkaloid, has been found to show significant antinociceptive activity. Here we report the antinociceptive activity of incarvillateine and compare its activity with that of morphine. Additionally, we suggest that its action may be related to influence on the central opioid pathways.

Force-induced rapid changes in cell fate at midpalatal suture cartilage of growing rats.

The application of expansional force induces replacement of the cartilaginous tissue with bone at the midpalatal suture of growing rats. We examined the early cellular events evoked by force by analyzing the expression of proliferating cell nuclear antigen (PCNA), an operational marker of cell proliferation, and of several bone matrix proteins. A rectangular orthodontic appliance was set between the right and left upper molars of four-week-old rats, with 50 g of initial expansional force. Two days after application of the force, the pre-existing cartilage was separated laterally. Mesenchymal cells with stretched shapes were arranged parallel to the expansional force and filled the center of the suture. Only a few of these stretched cells exhibited nuclear accumulation of PCNA. In contrast, many polygonal mesenchymal cells distributed along the inner lateral side of the cartilaginous tissue exhibited strong immunoreactivity for PCNA. Localization of alkaline phosphatase activity overlapped into this proliferating cell zone. Nascent extracellular matrix under the proliferating cells was positive for osteocalcin, indicating commencement of active bone formation. These findings indicated that, among mesenchymal cells subjected to expansional forces, only cells located on the inner side of the cartilaginous tissue proliferate and differentiate into osteoblasts. In agreement with rapid bone growth progression, apoptosis was also observed in the zone of proliferating cells, as measured by TdT-mediated dUTP-biotin nick end labeling (TUNEL) assays.

Cycloartane-type glycosides from Aquilegia flabellata.

Two new cycloartane-type glycosides, named aquilegiosides A and B, were isolated from the dried aerial parts of Aquilegia flabellata Sieb.et Zucc.var flabellata (Ranunculaceae). Their chemical structures have been characterized as 22S-3beta,16alpha,29-trihydroxy-cycloart-24-en-26,22-olid e 3-O-beta-D-glucopyranosyl-(1--->6)-beta-D-glucopyranosyl-(1--->2)-alpha- L-arabinopyranoside and 3-O-beta-D-glucopyranosyl-(1--->2)-alpha-L-arabinopyranoside, by chemical and spectroscopic evidence.

Comparison of the effects of gemfibrozil and clofibric acid on peroxisomal enzymes and cholesterol synthesis of rat hepatocytes.

We studied whether the peroxisomal proliferation, induction of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase) and activation of cholesterol synthesis by gemfibrozil shown in whole body (Hashimoto F., Ishikawa T., Hamada S. and Hayashi H., Biochemical. Pharm., 49, 1213-1221 (1995)) is also detected at a culture cell level, and we made a comparative analysis of the effects of clofibric acid. Gemfibrozil at 0.25 mM increased the activity of some peroxisomal enzymes (catalase and the cyanide-insensitive fatty acyl-CoA oxidizing system) after incubation for 72 h. However, contrary to whole body experiments, gemfibrozil decreased the activity of HMG-CoA reductase and cholesterol synthesis from [14C]acetate. At 1 mM, gemfibrozil decreased not only the activity of HMG-CoA reductase and cholesterol synthesis, but also the protein content of the cells and peroxisomal enzyme activity, indicating nonspecific inhibition at this concentration. Clofibric acid (0.25 and 1 mM) increased the activity of peroxisomal enzymes, but decreased the activity of HMG-CoA reductase and cholesterol synthesis. With respect to the direct effect on HMG-CoA reductase in the cell homogenate, gemfibrozil at 0.25 mm did not affect the activity, but it clearly inhibited the activity at 2 mM and above. Clofibric acid at 2 mM hardly affected the activity, but it clearly decreased the activity at 5 mM and over. That is, gemfibrozil directly inhibited the activity more strongly than clofibric acid. The direct inhibition of the enzyme itself required higher concentrations of both agents than did inhibition at the culture cell level. These results suggest that the cytotoxicity of gemfibrozil is greater than that of clofibric acid, and that gemfibrozil, as well as clofibric acid, can induce peroxisomal enzymes in the culture cell level. In contrast to whole body results, gemfibrozil may suppress cholesterol synthesis from [14C]acetate through the inhibition of HMG-CoA reductase at the culture cell level. The decreases in the reductase activity caused by gemfibrozil and clofibric acid at the culture cell level may not be caused by the direct inhibition of the enzyme.