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H Sugihara

Publications and source records attributed to H Sugihara.

At least 19 recordsLinked to original sources
PubMed2005

New antibody immobilization method via functional liposome layer for specific protein assays.

A specific protein assay system based on functional liposome-modified gold electrodes has been demonstrated. To fabricate such assay system, a liposome layer was initially grown on top of a gold layer. The liposome layer contained two kinds of functional molecules: biotin molecules for the binding sites of streptavidin and N-(10,12-pentacosadiynoic)-acetylferrocene molecules for the facile redox probe in electrochemical detections. Then, streptavidin was attached on the functional liposme-modified layer using the interaction of streptavidin-sbiotin complex. On the streptavidin-attached surface, antibody molecules, anti-human serum albumin antibodies could be immobilized without any secondary antibodies. AFM imaging of the streptavidin-attached liposome surface revealed a uniform distribution of closely packed streptavidin molecules. In situ quartz-crystal microbalance and electrochemical measurements demonstrated that the wanted antibody-antigen reactions should occur with high specificity and selectivity. Our specific antibody assay system, based on a functional liposome modified electrode, can be developed further to yield sophisticated structures for numerous protein chips and immunoassay sensors.

Antibodies↗
PubMed2005

Enhanced vagal modulation and exercise induced ischaemia of the inferoposterior myocardium.

OBJECTIVE: To determine whether the Bezold-Jarisch reflex or enhancement of vagal nerves, which are preferentially distributed in the inferoposterior myocardium, results from exercise induced ischaemia in this region. METHODS: On the basis of exercise myocardial scintigraphy and coronary angiography, 145 patients were classified as follows: group I, 34 patients with inferoposterior ischaemia; group A, 32 with anterior ischaemia; and control, 79 without ischaemia. The relation between ischaemic areas and ECG leads with ST segment changes and vagal modulation assessed by heart rate variability (HRV) (high frequency (HF) component (0.15-0.40 Hz) and coefficient of HF component variance (CCVHF), which is the square root of HF divided by mean RR interval) were assessed. RESULTS: The rate of ST segment depression in any lead did not differ between group I and group A. HF and CCV(HF) were similar before exercise but higher in group I than in group A and the control group after exercise (mean (SEM) HF: 94 (17) ms2, 41 (7) ms2, and 45 (6) ms2, respectively, p = 0.021; CCV(HF): 1.18 (0.09)%, 0.81 (0.07)%, and 0.89 (0.05)%, p = 0.0053). Furthermore, the percentage change in CCV(HF) before and after exercise was higher in group I than in group A or controls (mean (SEM) 22 (10)%, -24 (4)%, and -21 (3)%, p < 0.0001). The optimal cut off for diagnosis of inferoposterior ischaemia was -5% with a sensitivity of 74%, specificity 75%, and accuracy 75%. CONCLUSIONS: Vagal modulation as assessed by HRV analysis was enhanced in association with exercise induced inferoposterior ischaemia. Exercise ECG testing combined with HRV analysis would increase accuracy in the diagnosis of ischaemic areas in selected patients with angina pectoris.

Case-Control Studies↗
PubMed2004

Characterization of novel squamous cell carcinoma antigen-related molecules in mice.

The squamous cell carcinoma antigen 1 (SCCA1) and SCCA2 are unique serpins that can inhibit cysteine proteinases. SQN-5, their mouse ortholog, has already been identified, and its inhibitory property has been characterized; however, its biological role has remained undefined. Furthermore, no other mouse homolog of SQN-5 has been known. We characterize three mouse members of SCCA-related molecules including SQN-5 in this article. Serpinb3a (SQN-5) and Serpinb3b, but not Serpinb3c, were functional, inhibiting both serine and cysteine proteinases with different inhibitory profiles due to the difference of two amino acids in their reactive site loops. Serpinb3a was ubiquitously expressed in most tissues, whereas expression of Serpinb3b was limited to keratinocytes. Keratinocytes secreted both SCCA-related proteins, Serpinb3a and Serpinb3b. These results indicate that Serpinb3a and Serpinb3b may play different roles by inhibiting intrinsic or extrinsic proteinases with different expression distributions and different inhibitory profiles.

Amino Acid Sequence↗
PubMed2004

Usefulness of switching to cabergoline from other dopamine agonists in patients with advanced Parkinson's disease.

Problems associated with long-term treatment of advanced Parkinson's disease (PD) include motor complications and psychotic and autonomic symptoms. We switched patients from bromocriptine (BR) or pergolide (PER) to cabergoline (CB) therapy and investigated CB's usefulness in alleviating such problems. Subjects were 30 patients (mean age 68.2 years; 13 receiving BR, 17 PER) with PD complicated by effects of long-term treatment but in whom their dose of dopamine (DA) agonist was contraindicated due to adverse reactions. Patients were switched to CB over a 2-4-week period. Hoehn-Yahr and Unified Parkinson Disease Rating Scale (UPDRS) I-IV "on" and "off" scores improved in both the BR and PER groups. CB was not discontinued due to adverse reactions in any patient. In conclusion, switching to CB is useful in patients in whom it is problematic to increase their dose of DA agonist due to motor complications or psychotic symptoms of advanced PD.

Aged↗
PubMed2003

Prostate cancer cell growth is modulated by adipocyte-cancer cell interaction.

OBJECTIVE: To assess whether adipocytes (mesenchymal stromal cells thought to affect the proliferation and differentiation of epithelial cells) affect the behaviour of prostate cancer cells in vitro, as prostate cancer metastasizes to the bone, which is an adipocyte-rich environment. MATERIALS AND METHODS: The human bone-metastatic prostate carcinoma cell line PC3 was cultured with or without adipocytes in a three-dimensional collagen gel matrix. Histological and immunohistochemical assays were used to evaluate the proliferation and differentiation of PC3 cells. The cytokine expression of this culture assembly was also examined by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The proliferation and differentiation of cancer cells were clearly changed on co-culture with adipocytes compared with the control cultures. The mean (range) bromodeoxyuridine (BrdU) indices estimated (according to uptake) to evaluate the growth of the cultured cells were 36.3 (8.55)% in the co-culture and 26.95 (10.50) in the control (P < 0.02). PC3 cells in co-culture formed larger clusters than in the control, at 16.0 (11.0) vs 14.0 (10.0), respectively (P < 0.01). Cancer cells also showed pleomorphism, varying from cuboidal to spindle-shaped. The expressions of vascular endothelial and platelet-derived growth factor were greater in co-culture than in the control. CONCLUSION: These findings suggest that adipocytes modulate the growth, morphology and cytokine expression of prostate cancer cells. This specific mesenchymal stromal cell type is important in the biological behaviour of prostate cancer cells.

Adipocytes↗
PubMed2003

Cell kinetic study on histogenesis of Barrett's esophagus using rat reflux model.

BACKGROUND: To elucidate the histogenesis of Barrett's esophagus and esophageal adenocarcinoma, we designed a duodeno-gastric reflux model in which normal stomach function and normal nutritional status are retained. METHODS: Male Wistar rats were used in the experiment. The esophago-gastric junction was side-to-side anastomosed to a loop of jejunum about 3 cm distal to Treitz's ligament. The animals were not exposed to any known carcinogens during the experiment. Sequential morphological changes were studied for up to 50 weeks after surgery. Serial sections were made and stained with hematoxylin and eosin (H&E). In addition, immunohistochemical staining for bromodeoxyuridine (BrdU) was performed along with histochemical staining for mucins using paradoxical concanavalin A (ConA), galactose oxidase Schiff (GOS), and high-iron diamine-alcian blue (HID-AB). RESULTS: Severe esophagitis with squamous cell hyperplasia was noted in all animals after surgery. At week 20 after surgery, glandular metaplastic cells positive for ConA first appeared within the basal cell layer of esophageal squamous cell epithelium, and then GOS-positive cells and HID-AB goblet cells appeared. This is a characteristic of the specialized columnar epithelium of Barrett's esophagus. We detected esophageal adenocarcinomas in 1 out of 8 subjects at week 40 and in 3 out of 8 subjects at week 50 after surgery. CONCLUSIONS: Reflux of duodenal contents causes specialized columnar epithelium of Barrett's esophagus and esophageal adenocarcinoma. As part of the sequence of events leading to the development of Barrett's esophagus, pyloric-foveolar metaplasia was observed followed by the appearance of intestinal goblet cells. The pyloric-foveolar metaplasia appears to be associated with chronic mucosal damage and regeneration. This multiplastic cell lineage is referred to as 'gut-regenerative cell lineage' (GRCL).

Adenocarcinoma↗
PubMed2002

Bladder cancer cell implantation in reconstructed bladder in vitro: a model of tumour recurrence.

OBJECTIVE: To evaluate the involvement of umbrella cells in tumour adhesion and growth, by examining whether human urinary bladder carcinoma cells (HUBCC) can grow on reconstructed urinary bladder mucosa in vitro, as the implantation of tumour cells after resection is thought to be a cause of bladder tumour recurrence. MATERIALS AND METHODS: Normal transitional epithelial cells isolated from porcine bladder were cultured on reconstructed lamina propria using fibroblasts in type I collagen gel. The urothelium thus reconstructed was artificially injured either by a scalpel or by dilute acid, after which transitional epithelial cells began to grow in a stratified fashion within a few days of culture. A HUBCC line (HT-1197) was seeded onto this impaired mucosa to determine whether the cells could become implanted. Cultured cells on the reconstructed mucosa were evaluated by histological observation of vertical paraffin sections. RESULTS: The inoculated transitional epithelial cells grew in a stratified fashion and closely resembled urothelium in vivo. The superficial cells that were in contact with the medium solution differentiated into umbrella cells. HUBCC were unable to adhere to reconstructed mucosa which had not been injured, but these cells could adhere to and become implanted on the reconstructed mucosa after it had been injured either by a scalpel or by dilute acid. After acid injury, only the surface-covering cells were removed sporadically, while the lower epithelial cell layer remained intact. The bladder cancer cells adhered to and proliferated within these stripped regions. CONCLUSION: These results suggest that the urothelium, especially umbrella cells, seems to be important in preventing the adhesion and growth of urinary bladder tumour cells.

Animals↗
PubMed2001

MUC gene expression and histogenesis of adenocarcinoma of the stomach.

To elucidate the histogenesis of adenocarcinomas of the stomach, we examined MUC gene expression in gland-forming intramucosal neoplastic lesions. Eighty tumors were histopathologically assigned to 1 of the following 3 groups based upon the Vienna classification: group A (low-grade adenoma/dysplasia), group B (high-grade adenoma/dysplasia) and group C (intramucosal carcinoma). Immunohistochemic staining was performed with monoclonal antibodies against MUC2 (goblet cell mucin), MUC5AC (gastric-foveolar mucin), MUC6 (pyloric-gland mucin) and CD10 (brush border). Ki-67 staining was also carried out. An obvious difference existed in MUC gene expression between lesions in group A and those in groups B and C. The majority of group A lesions strongly expressed intestinal markers in which proliferating cell zones were formed but generally expressed no gastric markers, whereas more than 50% of groups B and C tumors expressed gastric markers. These findings suggest that group A lesions are of a stable intestinal phenotype, whereas those in groups B and C are phenotypically and genotypically unstable, indicating that the adenoma-carcinoma sequence is not a major pathway, but instead that adenocarcinomas arise de novo.

Adenocarcinoma↗
PubMed2001

Dye sensitization of nanocrystalline titanium dioxide with square planar platinum(II) diimine dithiolate complexes.

A series of platinum-based sensitizers of the general type Pt(NN)(SS), where NN is 4,4'-dicarboxy-2,2'-bipyridine (dcbpy) or 4,7-dicarboxy-1,10-phenanthroline (dcphen) and SS is ethyl-2-cyano-3,3-dimercaptoacrylate (ecda), quinoxaline-2,3-dithiolate (qdt), 1,2-benzenedithiolate (bdt), or 3,4-toluenedithiolate (tdt), that have various ground-state oxidation potentials has been synthesized and anchored to nanocrystalline titanium dioxide electrodes for light-to-electricity conversion in regenerative photoelectrochemical cells with an I(-)/I(-)(3) acetonitrile electrolyte. The intense mixed-Pt/dithiolate-to-diimine charge-transfer absorption bands in this series could be tuned from 440 to 580 nm by choosing appropriate dithiolate ligands, and the highest occupied molecular orbitals varied by more than 500 mV. Spectrophotometric titration of the Pt(dcphen)(bdt) complex exhibits a ground-state pK(a) value of 3.2 +/- 0.1, which can be assigned to the protonation of the carboxylate group of the dcphen ligand. Binding of Pt(dcbpy)(qdt) to porous nanostructured TiO(2) films was analyzed using the Langmuir adsorption isotherm model, yielding an adsorption equilibrium constant of 4 x 10(5) M(-1). The amount of dye adsorbed at the surface of TiO(2) films was 9.5 x 10(-8) mol/cm(2), which is ca. 50% lower than the full monolayer coverage. The resulting complexes efficiently sensitized TiO(2) over a notably broad spectral range and showed an open-circuit potential of ca. 600 mV with an impressive fill factor of > 0.70, making them attractive candidates for solar energy conversion applications. The visible spectra of the 3,4-toluenedithiol-based sensitizers showed an enhanced red response, but the lower photocurrent efficiency observed for these sensitizers stems in part from a sluggish halide oxidation rate and a fast recombination of injected electrons with the oxidized dye.

Journal Article↗
PubMed2001

Generation of polyclonal antiserum against the growth hormone secretagogue receptor (GHS-R): evidence that the GHS-R exists in the hypothalamus, pituitary and stomach of rats.

Growth hormone (GH) secretagogues (GHSs), which stimulate GH secretion, are synthetic compounds that act through the GHS receptor (GHS-R) which has been recently cloned. We raised an antiserum in a rabbit against a synthetic peptide corresponding to amino acid residues 248-260 of the third intracellular loop of the rat GHS-R. A competitive immunoassay showed that the antiserum had a specific affinity for the target peptide. To confirm the specificity of the antiserum, the GHS-R cDNA was stably expressed in COS-7 cells. In Western blot analysis, the band was detected at 44 kDa in the extracts from COS-7 cells expressing GHS-R (COS-7/tf3-2) but not in those from wild-type COS-7 cells. Furthermore, while COS-7/tf3-2 cells were strongly immunostained for GHS-R, no GHS-R-like immunoreactivity was observed in wild-type COS-7 cells. Immunoreactive bands were also observed at approximately 46 kDa in the extracts from rat hypothalamus, pituitary and stomach by Western blot analysis. These studies are the first to show the existence of GHS-R protein in the stomach. The antiserum for the GHS-R is sensitive and specific, and it would be useful for clarifying the roles of GHS/ghrelin.

Animals↗
PubMed2001

A patient with type I CD36 deficiency whose myocardium accumulated 123I-BMIPP after 4 years.

A 73-year-old man with aortic regurgitation was examined by 123I-alpha-methyl-p-iodophenylpentadecanoic acid (BMIPP) myocardial single photon emission computed tomography (SPECT) in 1995. Myocardial accumulation was not evident on either the early or the delayed image obtained 15 minutes and 3 hours, respectively, after injecting 123I-BMIPP. Flow cytometric analysis of CD36 expression in monocytes and platelets identified a type I CD36 deficiency. The patient was hospitalized for severe heart failure in 1999. Upon admission, the cardiothoracic ratio on chest X-rays was 73%, and the left ventricular end-diastolic diameter on echocardiograms was enlarged to 77 mm. On the second day, we performed 123I-BMIPP myocardial SPECT. Myocardial accumulation was evident in the delayed, but not in the early image. We repeated 123I-BMIPP myocardial SPECT on the 10th day after admission. Myocardial accumulation was evident on both early and delayed images. 99mTc-tetrofosmin myocardial SPECT was immediately performed after 123I-BMIPP myocardial SPECT to distinguish myocardial from pooling images in the left ventricle, but, because the images from both 99Tc-tetrofosmin and 123I-BMIPP myocardial SPECT were idential, we considered that the 123I-BMIPP myocardial SPECT images reflected the actual myocardial condition. The CD36 molecule transports long-chain fatty acid (LCFA) on the myocardial membrane, but 123I-BMIPP scintigraphy does not show any myocardial accumulation in patients with type I CD36 deficiency, indicating that myocardial LCFA uptake occurs through CD36 on the human myocardial membrane. Even though our patient had type I CD36 deficiency, BMIPP was uptaken by the myocardium during heart failure, suggesting a variant pathway on the human myocardial membrane for LCFA uptake.

Aged↗
PubMed2001

Dynamic changes in cardiac fatty acid metabolism in the stunned human myocardium.

BACKGROUND: The chronological changes or mechanisms in cardiac fatty acid metabolism under clinical conditions of hypoxia and ischemia have not been fully elucidated. 123-15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) can be used with single photon emission computed tomography (SPECT) to evaluate myocardial fatty acid metabolism. We investigated chronological changes in energy metabolism in the stunned human myocardium by means of 123I-BMIPP myocardial SPECT. METHODS AND RESULTS: We conducted 123I-BMIPP myocardial SPECT in 10 patients with stunned myocardium during the acute, subacute and chronic phases after onset. The left ventricle was divided into 9 regions on SPECT, and the degree of abnormalities in each region was scored in four grades from normal (0) to defect (4). We also examined wash-out rates on BMIPP images. The scores on early BMIPP images in the acute, subacute and chronic phases were 5.6 +/- 1.8, 13.4 +/- 3.5 and 2.5 +/- 1.1, respectively, and the score was highest in the subacute phase (p < 0.001). Similarly, scores on the late images were 2.3 +/- 1.7, 18.3 +/- 4.5 and 4.7 +/- 2.6, respectively, and highest in the subacute phase (p < 0.001). The wash-out rates (normal: 18.2 +/- 2.1%) in the acute, subacute and chronic phases were 12.1 +/- 4.8%, 44.9 +/- 10.0% and 23.1 +/- 4.6%, respectively, with the value being lowest during the acute phase (p < 0.05), and highest during the subacute phase (p < 0.001). CONCLUSION: These results suggested that fatty acid metabolism in the stunned human myocardium changes dynamically over time.

Aged↗
PubMed2001

Assessment of ampulla (Takotsubo) cardiomyopathy with coronary angiography, two-dimensional echocardiography and 99mTc-tetrofosmin myocardial single photon emission computed tomography.

UNLABELLED: We studied the causative mechanism of ampulla (Takotsubo) cardiomyopathy. METHODS: We examined 7 patients with ampulla cardiomyopathy by means of coronary angiography, two-dimensional echocardiography and 99Tc-tetrofosmin myocardial SPECT at the time of emergency admission (acute phase), at 3 to 5 days after the attack (subacute phase) and at 1 month after the attack (chronic phase). The left ventricle was divided into 9 regions on two-dimensional echocardiograms and 99mTc-tetrofosmin myocardial SPECT images, then the degree of abnormalities in each region was scored in four grades from normal (0) to severely abnormal (3). We injected nicorandil into the coronary arteries and determined the elevation in the ST segment before and after administration. RESULTS: Coronary angiography did not show stenotic lesions in any patient. The acute, subacute and chronic phase myocardial perfusion scores on 99mTc-tetrofosmin myocardial SPECT were 11.2 +/- 3.4, 2.7 +/- 2.3 and 0.4 +/- 0.5, respectively, and wall motion scores on echocardiograms were 13.0 +/- 3.6, 4.4 +/- 2.2 and 0.6 +/- 0.6, respectively, indicating improvement in all scores during the subacute phase (p < 0.01). The elevation in the ST segment (mm) on the electrocardiogram was improved from 8.3 +/- 2.7 to 4.9 +/- 1.9 after the administration of nicorandil (p < 0.05). CONCLUSION: These findings indicated that coronary microvascular spasm is one causative mechanism of ampulla cardiomyopathy.

Acute Disease↗
PubMed2001

Assessment of left ventricular diastolic function from quantitative electrocardiographic-gated 99mTc-tetrofosmin myocardial SPET.

We have developed new software which can evaluate left ventricular (LV) diastolic functional parameters from a quantitative gated SPET (QGS) program. To examine its accuracy, we compared these findings with the LV diastolic functional indices obtained from gated radionuclide ventriculography (RNV). Twenty-four patients were selected for this study. Gated SPET with technetium-99m tetrofosmin was performed and the QGS program was used with a temporal resolution of 32 frames per R-R interval. The LV volume of each frame was calculated and four harmonics of Fourier series were retained for the analysis of the LV volume curve. From this fitted curve and its first derivative curve, we derived LV systolic functional indices, e.g. ejection fraction (EF), peak ejection rate (PER) and time to PER (TPER), as well as LV diastolic functional variables, e.g. 1/3 filling fraction (1/3 FF), peak filling rate (PFR) and time to PFR (TPFR). Within 5+/-2 days, gated RNV was performed and diastolic functional parameters were determined by the same method. No significant difference was observed between the variables calculated by gated SPET and by gated RNV. There was a good correlation between EF, PER, TPER, 1/3 FF, PFR and TPFR determined by these two methods (EF: r=0.95, P<0.0001; PER: r=0.87, P<0.0001; TPER: r=0.84, P<0.0001; 1/3 FF: r=0.87, P<0.0001; PFR: r=0.92, P<0.0001; TPFR: r=0.89, P<0.0001). Bland-Altman plots did not reveal any significant degree of directional measurement bias in any of the comparisons of gated SPET data and RNV data. It is concluded that, in addition to the conventional LV systolic functional indices, our program accurately provides LV diastolic functional parameters from gated SPET. Also, this program will be useful for detecting LV diastolic dysfunction in various cardiac diseases before LV systolic dysfunction becomes evident.

Diastole↗
PubMed2001

Time-dependent expression of intestinal phenotype in signet ring cell carcinomas of the human stomach.

Signet ring cell carcinomas of the stomach are thought to arise from the proper gastric mucosa without intestinal metaplasia. It was recently reported that intestinal phenotypes appear along with tumor progression. In this study, we performed several experiments to reconsider the significance of this intestinalization in the growth of signet ring cell carcinoma. We applied mucin histochemistry with monoclonal antibodies MUC2 (Ccp58) and M1 (45M1), and paradoxical concanavalin A staining for class III mucin [PCS(III)] reaction to 29 intramucosal and 25 deeply invasive carcinomas of this type and correlated the phenotypic expression with the size of the mucosal spread and the depth of tumor invasion. It was found that the larger the size of the mucosal lesion, the more frequently the intestinal phenotypes were demonstrated. There was no significant increase in the expression of the intestinal phenotype as the tumor invaded the deeper part of the mucosa or as the intestinal metaplasia increased in the background mucosa. The intestinal expression appeared to be suppressed in the earlier phase of deep invasion. In the mucosal part of the tumor, the intestinal phenotype was often expressed regionally and incompletely, coexisting with gastric phenotypes at the cellular and the tissue levels. These findings indicate that the expression of the intestinal phenotype is a time-dependent and unstable phenomenon probably based on the accumulation of genetic changes and plays a neutral role in progression of signet ring cell carcinomas.

Adult↗
PubMed2001

Subcutaneous adipocytes promote the differentiation of squamous cell carcinoma cell line (DJM-1) in collagen gel matrix culture.

Cancer cell-stromal cell interaction plays a crucial role in the malignant growth of cancer cells. In the skin, the main stromal cell types consist of dermal fibroblasts and subcutaneous adipocytes. Fibroblasts are shown to promote the invasive growth of various cancer cell types. The interaction between cancer cells and stromal adipocytes, however, has not been sufficiently studied even in cutaneous carcinoma. To address the effects of adipocytes on the biologic behavior of cancer cells, we examined the growth and differentiation of a squamous cell carcinoma cell line of the skin (DJM-1), using a three-dimensional collagen gel matrix culture with a cutaneous environmental factor, air exposure. The growth was estimated by the uptake of bromodeoxy-uridine (BrdU) for 24 h. The BrdU indices of DJM-1 cells in stromal-cell-free, fibroblast-containing, and adipocyte- containing conditions were 19.7 +/- 1.9%, 19.8 +/- 2.8%, and 4.7 +/- 1.4%, respectively, whereas the BrdU index on the gel containing both fibroblasts and adipocytes was 10.4 +/- 3.3%. In terms of differentiation, DJM-1 cells cocultured with adipocytes constructed the best-organized stratified layer with a cornified-like structure in all conditions above. The differentiation markers involucrin and cytokeratin 10 were immunohistochemically detected in this structure of DJM-1 cells. Adipocyte-induced phenomena were not affected distinctively by air exposure. These results indicate that adipocytes, but not fibroblasts, promote the differentiation of squamous cell carcinoma cells (DJM-1) and inhibit their growth. These adipocyte-induced phenomena were not completely inhibited by fibroblasts. In conclusion, we suggest that stromal adipocytes may be involved in the differentiating mechanisms of cutaneous carcinoma cells.

Adipocytes↗
PubMed2001

Effects of fat cells on keratinocytes and fibroblasts in a reconstructed rat skin model using collagen gel matrix culture.

BACKGROUND: Fat cells (stromal tissue cells), not only have the function of lipid metabolism, but produce various cytokines that exert an influence on other cell types through paracrine or endocrine mechanisms. OBJECTIVES: To elucidate possible roles of fat cells in the skin, we examined their effects on the biological behaviour of keratinocytes and dermal fibroblasts in culture. METHODS: In the present study, focusing upon fat cell--keratinocyte or fat cell--dermal fibroblast interactions, we used a reconstructed skin system with rat skin cells in a three-dimensional collagen gel matrix culture. RESULTS: In this coculture system, fat cells promoted the proliferation and differentiation of keratinocytes. When keratinocytes were seeded directly on the fat cell layer without dermal fibroblasts, they proliferated extensively and formed a thick epidermal layer with a well-differentiated structure. Conversely, fat cells inhibited the proliferation of dermal fibroblasts. These effects of fat cells were presumed to be mediated by cytokines derived from the fat cells. CONCLUSIONS: The effects of fat cells could not be mimicked by the addition of leptin, tumour necrosis factor-alpha or insulin-like growth factor-II, suggesting that fat cells are mediating these activities via some other cytokines.

Adipocytes↗