Transforming growth factor-β₁-induced expression of connective tissue growth factor is enhanced in bronchial fibroblasts derived from asthmatic patients

INTRODUCTION

Bronchial asthma is accompanied by airway remodeling as well as increased secretion of cytokines, growth factors, and extracellular matrix proteins. Connective tissue growth factor (CTGF) has been suggested to contribute to many fibrotic disorders. However, the ability of human bronchial fibroblasts (HBFs) to express CTGF in response to transforming growth factor-β₁ (TGF‑β₁) has not been studied so far.

OBJECTIVES

The aim of the study was to investigate whether HBFs are able to express CTGF when stimulated with TGF‑β₁.

PATIENTS AND METHODS

All experiments were conducted on in vitro cultures of HBFs isolated from bronchial biopsies obtained from 8 patients with asthma and from 5 nonasthmatic individuals. We performed an analysis of changes in mRNA expression for CTGF and α‑smooth muscle actin and in protein expression for CTGF.

RESULTS

We have shown for the first time that HBFs derived from asthmatic patients are capable of higher CTGF expression when stimulated with TGF‑β₁ compared with HBFs isolated from nonasthmatic individuals. Moreover, this effect is significantly reduced after the Wnt signaling pathway activation.

CONCLUSIONS

Our results point to a pleiotropic effect of TGF-β₁, the elevated levels of which are observed in the bronchoalveolar lavage fluid obtained from asthmatic patients. The structural cells of the bronchi, fibroblasts, stimulated with TGF‑β₁ begin to synthesize CTGF. Moreover, this process can be reversed by the GSK‑3β inhibitor, which activates the Wnt signaling pathway. Our model, based on in vitro primary cell cultures, may be a valuable experimental approach to study the mechanisms underlying bronchial wall remodeling, and in the future it may lead to the development of new therapeutic strategies in asthma.

Transition of asthmatic bronchial fibroblasts to myofibroblasts is inhibited by cell-cell contacts

The role of airway wall remodelling in bronchial asthma is well established. Myofibroblasts, the cells displaying features intermediate between fibroblasts and smooth muscle cells, are involved in this process but the mechanism of myofibroblasts activation in the onset of the disease remains obscure. Myofibroblasts can differentiate from various cell types, including resident fibroblasts, and the fibroblasts to myofibroblasts transition (FMT) can be reproduced in vitro. We aimed to investigate the process of FMT in human bronchial fibroblasts (HBF) derived from non-asthmatic (n = 7) and asthmatic (n = 7) subjects. We also tested whether cell-cell contacts affect FMT by using N-cadherin blocking antibody. HBF plated in low or high cell density were treated with TGF-β(1) up to one week to induce FMT. The percentage of myofibroblsts was counted and expression of α-smooth muscle actin was evaluated by cytoimmunofluorescence, flow cytometry and immunobloting. We demonstrated that the intensity of FMT induced by TGF-β(1)in vitro was strongly enhanced in asthmatic as compared to non-asthmatic HBF populations. This process was facilitated by low cell plating density in both groups of cultures. Furthermore, we proved that neither HBF-conditioned medium nor growth arrest in G(0)/G(1) phase of cell cycle could stop the TGF-β(1)-induced FMT in asthmatic cell populations. However, even in sparse asthmatic HBF, the blocking of N-cadherin resulted in the inhibition of FMT. Our findings show for the first time that the initial absence or an induced loss of cell-cell adhesions in asthmatic HBF populations is important for the completion of FMT.

Asthmatic bronchial fibroblasts demonstrate enhanced potential to differentiate into myofibroblasts in culture

BACKGROUND

Chronic inflammation and remodeling of the bronchial wall are basic hallmarks of asthma. It is known that mesenchymal cells in the lamina reticularis underlying the basement membrane of the thickened airway wall of asthmatics predominantly display the phenotype of myofibroblasts and express alpha-smooth muscle actin (alpha-SMA). Human bronchial fibroblasts (HBFs) transform in vitro into myofibroblasts under the influence of transforming growth factor (TGF-beta). Differences in the reactivity of fibroblasts to TGF-beta in cultures derived from healthy and asthmatic donors are elucidated here.

MATERIAL/METHODS

Primary human bronchial fibroblasts (HBFs) were cultured from bronchial biopsies from non-asthmatic (n=7) and asthmatic (n=7) donors and treated with TGF-beta1 or TGF-beta2 to induce myofibroblast differentiation. Expression of alpha-smooth muscle actin (alpha-SMA) was assessed by immunocytochemistry and Western blotting. The cell size and shape parameters were measured by computer-aided methods.

RESULTS

Regardless of whether TGF-beta1 or TGF-beta2 was used, asthmatic cells showed enhanced expression of the myofibroblast marker as confirmed by immunocytochemistry and immunoblotting. Analysis of the shape parameters of cells incubated in the presence of TGF-beta1 revealed that HBFs of asthmatics differ from those of non-asthmatics.

CONCLUSIONS

It is concluded that asthmatic HBFs cultured in vitro display some inherent features which facilitate their differentiation into myofibroblasts. These data indicate that increased reactivity of asthmatic fibroblasts to TGF-beta may play a crucial role in asthma.

A triterpene saponin from Lysimachia thyrsiflora L

A triterpene saponoside (LTS-4) isolated from the underground parts of Lysimachia thyrsiflora L. was defined as 3-O-{beta-D-xylopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 4)-[beta-D-glucopyranosyl-(1 --> 2)]-alpha-L-arabinopyranosyl}-cyclamiretin A. Structure assignment was performed on the basis of spectroscopic data including homo- and heteronuclear 1D and 2D NMR (COSY, TOCSY, NOESY, HETCOR, HMBC and DEPT) and FAB-MS studies. The compound was tested in vitro for antimicrobial and cytotoxic activity.

YY1 is recruited to the cytoplasm of vaccinia virus-infected human macrophages by the Crm1 system

The influence of vaccinia virus infection on activity and subcellular localization of cellular transcription factors YY1 and C/EBPbeta in human blood monocytes derived macrophages was examined. YY1 activity, shown by electrophoretic mobility shift assay, decreased upon infection in the nuclear extracts but remained unchanged in whole cell extracts until 48h post-infection (p.i.). Immunohistochemical staining of the fixed cells showed translocation of the factor to the cytoplasm of the infected macrophages. The nuclear export of YY1 was blocked by leptomycin B, an inhibitor of the Crm1-dependent export system. C/EBP DNA binding activity was transiently increased during viral infection. Cytoplasmic translocation of the C/EBPbeta has also been observed and was found to be blocked by leptomycin B treatment of the cells. It appears that the Crm1 system is not impaired by the virus infection in blood-derived macrophages and that it remains operative for redirection of subcellular localization of transcription factors from the nucleus to the cytoplasm. Moreover, blockage of the nuclear export by leptomycin B significantly affected the yield of infectious virus. The results might help to better understand the mechanism of protein transport during viral infection of monocyte-derived cells.

The effect of triethyllead on the motile activity of walker 256 carcinosarcoma cells

The effect of triethyllead (TriEL) on the morphology and motile activity of Walker 256 carcinosarcoma cells was investigated. It was found that both 2 and 5 microM TriEL affected the cellular motility in a dose- and time-dependent manner. Initially, 2 microM TriEL caused the formation of blebs instead of lamellipodia at the front of some cells and stimulated the migration of Walker cells, but after 2 hours of 2 microM TriEL treatment, a reduction of cellular motility was observed. In the presence of 5 microM TriEL, Walker 256 carcinosarcoma cells rounded up, and their rate of movement was reduced. Moreover, the treatment of Walker carcinosarcoma cells with TriEL caused the disruption of microtubules and affected the F-actin distribution at both concentrations. At a concentration of 2 microM TriEL, the actin staining intensity was greatest in the tail of front-tail polarised blebbing cells and the actin layer was very thin at the leading edge. The control cells showed linear cortical F-actin distribution and somewhat less intense cytoplasmic staining at the same TriEL concentration. Cells treated with 5 microM TriEL showed an under-membrane pattern of actin distribution.

Procaine-induced enhancement of fluid-phase endocytosis and inhibition of exocytosis in human skin fibroblasts

Local anaesthetics are often applied directly onto the skin, and for this reason the effect of some local anaesthetics upon morphology and cytoskeleton organisation in human skin fibroblasts was investigated. In this paper the authors report that procaine (p-aminobenzoic acid diethylamino-etyl ester hydrochloride) induced vacuolisation of cytoplasm and great enhancement of neutral red accumulation in human skin fibroblasts cultured in vitro. Procaine-induced vacuolisation of cell's cytoplasm was observed to be associated with the enhanced uptake and inhibited release of fluid taken by endocytosis. All these effects appeared fully reversible. The cell vacuolisation cannot be prevented by 3-methyadenine, brefeldine A, and cytochalasine D. On the other hand, nocodazole and caffeine prevent cytoplasm vacuolisation induced by procaine. These observations suggest that procaine-induced formation of great vacuoles is due to an impairment of membrane traffic between endosomes. The authors' results also demonstrate that neutral red uptake assay, if used as a cell viability test, must be interpreted with great caution.

A prospective, randomized, unicenter study comparing laparoscopic and open treatments of acute appendicitis

BACKGROUND

Appendectomy in the course of acute appendicitis is one of the most frequently performed surgical procedure in general surgery. The aim of this study was to compare the results of laparoscopic and conventional treatments for acute appendicitis in a prospective, randomized, unicenter study.

METHODS

The study involved 200 patients treated for acute appendicitis in the Department of General and Vascular Surgery at Ceynowa Hospital in Wejherowo, Poland.

RESULTS

The mean operative time for open surgery was 36.99 min. For laparoscopic method the operation was longer, requiring 47.75 min. Suction drainage was applied in 23 patients treated conventionally and 50 patients treated laparoscopically ( p < 0.05). The requirement for analgesia, measured by the number of metamizole ampules, was significantly higher in the conventional group. Pain on postoperative days 2 and 7 measured using a visual analog scale, was significantly more severe for the patients treated conventionally. The hospital stay in both groups did not differ significantly: 5.03 days for the conventional group and 4.71 days for the laparoscopic group. The time until return to work and social activities in the laparoscopic group (15.85 days) and was significantly shorter than in the conventional group (19.65 days). Seven complications occurred in the conventional group (6.7%) and nine (9.4%) in the laparoscopic group. The difference was not statistically significant. No deaths occurred.

CONCLUSIONS

On the basis of the conducted study, it may be assumed that laparoscopic appendectomy is a safe procedure, and that postoperative morbidity is comparable with that for a conventional operation. There was less postoperative pain and shorter recovery time after laparoscopic surgery than after the open procedure.

Folic acid, ascorbic acid and sodium selenite restore the motility of Dictyostelium discoideum inhibited by triethyllead

The effect of triethyllead (TriEL) on motile activity, structure of cytoskeleton and chemotaxis of Dictyostelium discoideum amoebae in developing concentration gradients of folic acid (FA) and cAMP has been studied. It was observed that 3 microM TriEL had little or no effect on locomotion and chemotactic response of cells, whereas 5 microM TriEL strongly reduced the motile activity of Dictyostelium discoideum amoebae and inhibited their chemotaxis towards cAMP, but not towards FA. FA was found to restore the motile activity of Dictyostelium discoideum, inhibited by TriEL. A similar effect was observed in the presence of other antioxidants, i.e. ascorbic acid and sodium selenite, suggesting that oxidative stress may be involved in the action of TriEL. Moreover, the treatment of Dictyostelium amoebae with 5 microM TriEL caused disruption of microtubules while 3 microM TriEL had little effect on their structure. FA caused restoration of microtubules only in some cells within 1 h of incubation, i.e. when the directional movement of cells towards this chemoattractant was already observed. However, their organization was significantly different from that observed in the untreated cells, suggesting that microtubule undisturbed organisation may be not necessary for Dictyostelium discoideum amoebae locomotion and chemotaxis

Asymmetric hydrogenation of dehydrodipeptides bearing different protecting groups

N-[(Z)-N-Benzoyl- or N-boc-(2-fluorophenyl)dehydroalanyl]-(R)- or (S)-phenyl-alanines 1,2,5 and 6 were hydrogenated in the presence of chiral and achiral rhodium complexes. The optical induction is compared to the results obtained using the corresponding esters as substrates.

Contact-mediated acceleration of migration of melanoma B16 cells depends on extracellular calcium ions

The escape of malignant cells from primary tumour and their active migration to the surrounding tissues are among the most important steps in the metastatic process. During migration, tumour cells interact with neighbouring neoplastic and normal cells and such interactions may affect their motile activity. We investigated the effect of extracellular calcium ions on migration of mouse melanoma B16 cells stimulated by homotypic cell-to-cell contacts. It was found that the decreasing of extracellular Ca2+ influx into B16 cells by lowering Ca2+ concentration in culture medium, or by the application of 0.5 mM La3+ (non-selective inorganic Ca2+ channels blocker), reduced the contact-mediated acceleration of migration of melanoma cells but only slightly affected the basal motile activity of non-stimulated single, separated cells moving without contacts with neighbouring ones in sparse culture. Since it was suggested that contact-mediated acceleration of migration of melanoma B16 cells may be controlled by mechanosensitive and/or voltage-gated ion channels, the presented data support the concept that these channels may affect cell migration by regulation of extracellular Ca2+ influx into stimulated cell.

[Laparoscopic cholecystectomy in elderly patients]

The report presents results of the treatment of cholecystolithiasis in old patients (65 years). We compared two groups of the patients: first group treated using laparoscopic method, second group (control) where we performed classic cholecystectomy. Both of these groups were comparable according to age and sex.

NMR spectra of fluorinated carbohydrates

Recent advances in structural and conformational analysis of fluorinated carbohydrates by NMR spectroscopy are reviewed. Characteristic 1H, 13C, and 19F NMR chemical shifts and coupling constants for selected examples are given and the spectral data of a series of fluorinated carbohydrates were collected in continuation of the review of Csuk and Glänzer [Adv. Carbohydr. Chem. Biochem., 46 (1988) 73-177].

[Gastric neurilemmoma complicated by gastroduodenal intussusception and with bleeding from the digestive tract]

A case of Gastric Neurilemmoma with bleeding and gastroduodenal intussusception was described.

Asymmetric hydrogenation of dehydrodipeptide esters bearing different protective groups

N-[(Z)-N-Benzoyl- or N-Boc-(2-fluorophenyl)dehydroalanyl]-(R)- or (S)-phenylalanine esters were synthesized and hydrogenated to give the corresponding dipeptide derivatives with optical yields in the range of 53-87% de using the cationic rhodium complexes of PROPRAPHOS and BPPM. The efficiency of chiral diphosphine ligands as well the effect of the chiral center in the substrate on the catalytic asymmetric induction was studied.

Unusual amino acids. VIII. Asymmetric hydrogenation of some heteroaryl-N-Cbz and N-Boc aminocinnamic acid derivatives

(Z)-alpha-[(Benzyloxy)- or (tert.-butyloxy)carbonylamino]-beta (thienyl)- or (furyl)-acrylic acids and their esters were prepared by known methods and hydrogenated to the corresponding optically active alanine derivatives with optical yields in the range of 58-93% ee using the cationic rhodium complex of "PROPRAPHOS".

Changes in morphology of human skin fibroblasts induced by local anaesthetics: role of actomyosin contraction

Local anaesthetics block action potentials in the membranes of excitable cells but their effects on non-excitable cells are less well known. Some local anaesthetics are applied directly onto the skin, and for this reason the effect of procaine (p-aminobenzoic acid diethylamino-etyl ester hydrochloride) and tetracaine (4-[butylamino]benzoic acid 2-[dimethylamino]ethyl ester) upon the morphology and cytoskeleton organisation of human skin fibroblasts was investigated. The time lapse video recording of fibroblasts cultured in serum-enriched medium revealed that the cells rapidly change shape after the addition of the anaesthetic. These effects were fully reversible. The microscopic observations were confirmed by quantitative analysis of projected cell area and cell shape parameters. Local anaesthetics significantly changed the actin cytoskeleton organisation, inducing total disappearance of stress fibres. Serum-starvation or myosin light chain kinase inhibitors, KT 5926 inhibitor (8R*,9S*,11S*)-(-)-9-hydroxy-9-methoxycarbonyl-8-methyl-14-n-propoxy-2,3 ,9, 10-tetrahydro-8,11-epoxy,1H,8H,11H-2,7b,11a-triazadibenzo[a,g]c ycloocta[cde] trinden-1-one or wortmannin, which induce the 'relaxed' morphology of the cells, prevent both the anaesthetic-induced changes in cell shape and the disassembly of stress fibres. Together, the observations suggest that local anaesthetics affect the actomyosin system, inducing contraction.