Bioinformatic Analysis of the BCL-xL/BCL2L1 Interactome in Patients with Pancreatic Cancer

Objectives: The aim of the present study was to analyze the differential gene expression of BCL-xL/BCL2L and the associated genetic, molecular, and biologic functions in pancreatic ductal adenocarcinoma (PDAC) by employing advanced bioinformatics to investigate potential candidate genes implicated in the pathogenesis of PDAC. Materials and Methods: Bioinformatic techniques were employed to build the gene network of BCL-xL, to assess the translational profile of BCL-xL in PDAC, assess its role in predicting PDAC, and investigate the associated biologic functions and the regulating miRNA families. Results: Microarray data extracted from one dataset was incorporated, including 130 samples (PDAC: 69; Control: 61). In addition, the expression level of BCL-xL was higher in PDAC compared to control samples (p < 0.001). Furthermore, BCL-xL demonstrated excellent discrimination (AUC: 0.83 [95% Confidence Intervals: 0.76, 0.90]; p < 0.001) and calibration (R squared: 0.31) traits for PDAC. A gene set enrichment analysis (GSEA) demonstrated the molecular functions and miRNA families (hsa-miR-4804-5p, hsa-miR-4776-5p, hsa-miR-6770-3p, hsa-miR-3619-3p, and hsa-miR-7152-3p) related to BCL-xL. Conclusions: The current findings unveil the biological implications of BCL-xL in PDAC and the related molecular functions and miRNA families.

Establishment of Patient-derived Orthotopic Xenografts (PDX) as Models for Pancreatic Ductal Adenocarcinoma

BACKGROUND/AIM

Pancreatic cancer (PC) is one of the leading causes of cancer-related death. The purpose of the present study was to establish a patient-derived orthotopic xenograft model (PDOX) for pancreatic ductal adenocarcinoma (PDAC), thus providing a tumor microenvironment resembling that of the human pancreas to identify novel potential biomarkers and treatment regimens.

MATERIALS AND METHODS

PDAC tissue samples were received from 35 patients, following informed consent, and three mouse strains were implemented.

RESULTS

Successful PDOX engraftment was performed in nonobese diabetic/severe combined immunodeficient (NOD/SCID) and NOD/SCID gamma (NSG) mice. Nonetheless, we found a higher rate of successful engraftment and tumor growth in NSG compared to NOD/SCID mice, possibly owning to the different level of immunosuppression and more specifically of the natural killer cells presence.

CONCLUSION

Our suggested PDOX model represents a preclinical cancer research model with a high affinity for the patient's tumor microenvironment, thus enabling the acceleration of PDAC research.

Effects of In Vitro Muscle Contraction on Thermogenic Protein Levels in Co-Cultured Adipocytes

The crosstalk between the exercising muscle and the adipose tissue, mediated by myokines and metabolites, derived from both tissues during exercise has created a controversy between animal and human studies with respect to the impact of exercise on the browning process. The aim of this study was to investigate whether co-culturing of C2C12 myotubes and 3T3-L1 adipocytes under the stimuli of electrical pulse stimulation (EPS) mimicking muscle contraction can impact the expression of UCP1, PGC-1a, and IL-6 in adipocytes, therefore providing evidence on the direct crosstalk between adipocytes and stimulated muscle cells. In the co-cultured C2C12 cells, EPS increased the expression of PGC-1a (p = 0.129; d = 0.73) and IL-6 (p = 0.09; d = 1.13) protein levels. When EPS was applied, we found that co-culturing led to increases in UCP1 (p = 0.044; d = 1.29) and IL-6 (p = 0.097; d = 1.13) protein expression in the 3T3-L1 adipocytes. The expression of PGC-1a increased by EPS but was not significantly elevated after co-culturing (p = 0.448; d = 0.08). In vitro co-culturing of C2C12 myotubes and 3T3-L1 adipocytes under the stimuli of EPS leads to increased expression of thermogenic proteins. These findings indicate changes in the expression pattern of proteins related to browning of adipose tissue, supporting the use of this in vitro model to study the crosstalk between adipocytes and contracting muscle.

Remedies of animal origin and their indications in Nikolaos Myrepsos׳ Dynameron

ETHNOPHARMACOLOGICAL RELEVANCE

Dynameron is a Byzantine medical compendium, divided into 24 sections, in accordance with the letters of the Greek alphabet. Being the largest medical and pharmaceutical book ever written in Byzantium, Dynameron contains 2667 recipes intended to treat many pathological conditions. A lot of information convey to us through prescriptions. In addition to plants, Nikolaos Myrepsos proposes the use of many animals, animal parts and animal by-products, for the treatment of various diseases. This article presents for the first time a full account of the animal products included in Dynameron.

AIM OF THE STUDY

In continuation to our previous studies, this paper focuses on the use of animal products in composite medicines described in Dynameron. An effort was made to trace down the use of similar or identical animal products in texts of earlier medical writers. Recording recipes with animals or animal products intended for use in everyday medical practice highlights the timeless belief in their healing properties.

MATERIALS AND METHODS

Our main source of material is the recent digital edition of Nikolaos Myrepsos' Dynameron. This huge treatise was written in the 13^th century and reflects in many ways the long medical tradition of the Greek, the Hellenistic and the Roman eras, having also received influences from the materia medica of Arabic medicine. In addition, information from dictionaries and databases were cross-checked to confirm and classify the animals and their products and to identify them. For the various pathological conditions these products are meant for, we have used the current medical terminology.

RESULTS

In the present study, we could identify the therapeutic use of 93 animals. In several instances, Myrepsos suggests the use of specific organs of an animal, and for that reason he includes in his treatise 16 anatomical parts of different animals. Moreover, Dynameron comprises also 34 animal by-products, such as milk and honey. Medicines of animal origin are used in recipes concerning diseases of the respiratory, the digestive, the cardiovascular and the urinary system, as well as gynecological diseases, and ailments of the eyes, the ears and the skin.

CONCLUSIONS

Of the 2667 recipes of Dynameron, 344 recipes contain medicines of animal origin, which can be detected in totally 769 citations. In addition, 626 citations for animal by-products are found in 268 recipes. Honey and milk are quoted in 2136 recipes, mostly as excipients. Dietary instructions are present on many occasions, reflecting the attitude for a healthy everyday life, similar to the modern beliefs pertaining to food as an essential factor for a good health.

In Silico Transcriptomic Analysis of the Chloride Intracellular Channels (CLIC) Interactome Identifies a Molecular Panel of Seven Prognostic Markers in Patients with Pancreatic Ductal Adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDAC) is associated with poor prognosis. In this context, the identification of biomarkers regarding the PDAC diagnosis, monitoring, and prognosis is crucial.

Objectives

The purpose of the current study was to investigate the differential gene expression profile of the chloride intracellular channel (CLIC) gene family network in patients with PDAC, in order to suggest novel biomarkers.

Methods

In silico techniques were used to construct the interactome of the CLIC gene family, identify the differentially expressed genes (DEGs) in PDAC as compared to healthy controls, and evaluate their potential prognostic role.

Results

Transcriptomic data of three microarray datasets were included, incorporating 114 tumor and 59 normal pancreatic samples. Twenty DEGs were identified; eight were up-regulated and twelve were downregulated. A molecular signature of seven genes (Chloride Intracellular Channel 1 – CLIC1; Chloride Intracellular Channel 3 – CLIC3; Chloride Intracellular Channel 4 – CLIC4; Ganglioside Induced Differentiation Associated Protein 1 – GDAP1; Ganglioside Induced Differentiation Associated Protein 1 Like 1 – GDAP1L1; Glutathione S-Transferase Pi 1 - GSTP1; Prostaglandin E Synthase 2 – PTGES2) were identified as prognostic markers associated with overall survival. Positive correlations were reported regarding the expression of CLIC1-CLIC3, CLIC4-CLIC5, and CLIC5-CLIC6. Finally, gene set enrichment analysis demonstrated the molecular functions and miRNA families (hsa‐miR‐122, hsa‐miR‐618, hsa‐miR‐425, and hsa‐miR‐518) relevant to the seven prognostic markers.

Conclusion

These outcomes demonstrate a seven-gene molecular panel that predicts the patients’ prospective survival following pancreatic resection for PDAC.

Transcriptomic analysis of the Aquaporin (AQP) gene family interactome identifies a molecular panel of four prognostic markers in patients with pancreatic ductal adenocarcinoma

BACKGROUND

This study aimed to assess the differential gene expression of aquaporin (AQP) gene family interactome in pancreatic ductal adenocarcinoma (PDAC) using data mining techniques to identify novel candidate genes intervening in the pathogenicity of PDAC.

METHOD

Transcriptome data mining techniques were used in order to construct the interactome of the AQP gene family and to determine which genes members are differentially expressed in PDAC as compared to controls. The same techniques were used in order to evaluate the potential prognostic role of the differentially expressed genes.

RESULTS

Transcriptome microarray data of four GEO datasets were incorporated, including 142 primary tumor samples and 104 normal pancreatic tissue samples. Twenty differentially expressed genes were identified, of which nineteen were downregulated and one up-regulated. A molecular panel of four genes (Aquaporin 7 - AQP7; Archain 1 - ARCN1; Exocyst Complex Component 3 - EXOC3; Coatomer Protein Complex Subunit Epsilon - COPE) were identified as potential prognostic markers associated with overall survival.

CONCLUSION

These outcomes should be further assessed in vitro in order to fully understand the role of these genes in the pathophysiological mechanism of PDAC.

Patient Derived Xenografts (PDX) for personalized treatment of pancreatic cancer: emerging allies in the war on a devastating cancer?

The prognosis of pancreatic ductal adenocarcinoma (PDAC), the eighth most lethal cancer for men and ninth for women worldwide, remains dismal. The increasing rates of deaths by PDAC indicate that the overall management of the disease in 21st century is still insufficient. Thus it is obvious that there is an unmet need to improve management of PDAC by finding new biomarkers to screen high risk patients, confirm diagnosis, and predict response to treatment as well more efficacious and safer treatments. Patient Derived Xenografts (PDX) have been developed as a new promising tool in an effort to mirror genetics, tumor heterogeneity and cancer microenvironment of the primary tumor. Herein we aim to give an updated overview of the current status and the perspectives of PDX in the search for the identification of novel biomarkers and improved therapeutic outcomes for PDAC but also their use as a valuable tool towards individualized treatments to improve the outcome of the disease. Furthermore, we critically review the applications, advantages, limitations, and perspectives of PDX in the research towards an improved management of PDAC.

SIGNIFICANCE

This review provides a comprehensive overview of the current status and the potential role as well as the challenges of PDX in the road to fight one of the most lethal cancers in the developed countries, pancreatic ductal adenocarcinoma.

Ethnopharmacological approach to the herbal medicines of the "Elements Alpha to Delta" in Nikolaos Myrepsos׳ Dynameron. Part II

ETHNOPHARMACOLOGICAL RELEVANCE

Dynameron is a Byzantine medical compendium, divided into 24 sections, the "Elements", containing 2667 recipes, most of which inherited by previous physicians of the classic ancient Greek and Hellenistic, and imperial Roman periods.

AIM OF THE STUDY

In continuation to our previous study concerning the first and largest chapter of the "Element Alpha" of Nikolaos Myrepsos׳ Dynameron (Valiakos et al., 2015), this paper focuses on the plants quoted in the recipes of the eight following chapters entitled "About Salts", "About Honeypacks" and "About Spreads", all belonging to the same "Element Alpha"; "About Antitussives" and "About Suppositories" belonging to the "Element Beta"; "About women's Cathartics" belonging to the "Element Gamma"; "About Drossaton" and "About Diachrisma", both belonging to the "Element Delta".

MATERIALS AND METHODS

Our main primary source material was the codex kept in the National Library of France (in Paris) under the number grec. 2243, which is the older and larger codex of Dynameron (Valiakos et al., 2015).

RESULTS

The present study led us to the interpretation of 277 plants under different names, among which we recognized 57 medicinal plants listed by the European Medicines Agency, one of them with negative monograph (i.e. Chelidonium majus). In addition, there are identified taxa related to those quoted by EMA as herbal medicines. The plants appearing in the examined Elements belong to various families of which the most frequent are: Apiaceae 10.11%; Lamiaceae 7.22%; Asteraceae 6.86%; Rosaceae 6.5% and Fabaceae 6.14%.

CONCLUSIONS

A total of 277 species have been catalogued, most of which are referred in our previous publication (Valiakos et al., 2015). Among them, 56 plants still play a very important role in medical practice, as they are used as traditional herbal medicines (www.ema.eu). This evidence is a proof that the use of medicinal plants remains valuable from the ancient times until today. The recipes, in contrast to older medical compendia, contain precise measurements of ingredients and dosages for every drug, which seem to reflect empirical logic.

The Prognostic Significance of the Hedgehog Signaling Pathway in Colorectal Cancer

Despite significant advances in the management of colorectal cancer (CRC) the identification of new prognostic biomarkers continues to be a challenge. Since its initial discovery, the role of the Hedgehog (Hh) signaling pathway in carcinogenesis has been extensively studied. We herein review and comment on the prognostic significance of the Hh signaling pathway in CRC. The differential expression of Hh pathway components between malignant and nonmalignant conditions as well as correlation of Hh activation markers with various clinicopathological parameters and the effect on disease-free survival, overall survival, and disease recurrence in patients with CRC is summarized and discussed. According to the studies reviewed herein the activation of the Hh pathway seems to be correlated with adverse clinicopathological features and worse survival. However, to date study results show significant variability with regard to the effect on outcomes. Such results need to be interpreted carefully and emphasize the need for further well designed studies to characterize the actual influence of the Hh pathway in CRC prognosis.

Ethnopharmacological approach to the herbal medicines of the "Antidotes" in Nikolaos Myrepsos׳ Dynameron

ETHNOPHARMACOLOGICAL RELEVANCE

This paper focuses on the plants quoted in the recipes of the first chapter entitled "About the Antidotes" belonging to the first and largest section "Element Alpha" of Nikolaos Myrepsos׳ Dynameron, a medieval medical manuscript. Nikolaos Myrepsos was a Byzantine physician at the court of John III Doukas Vatatzes at Nicaea (13th century). He wrote in Greek a rich collection of 2667 recipes, the richest number known in late Byzantine era, conventionally known as Dynameron and divided into 24 sections, the "Elements". The only existing translation of this work is in Latin, released in 1549 in Basel by Leonhart Fuchs. Since no other translation has ever been made in any language, this work still remains poorly known.

MATERIALS AND METHODS

Our primary source material was the codex written in 1339 and kept in the National Library of France (in Paris) under the number grec. 2243. For comparison, all the other codices, which contain the entire manuscript, have also been studied, namely the codices EBE 1478 (National Library of Greece, Athens), grec. 2237 and grec. 2238 (both in Paris), Lavra Ε 192 (Mont Athos, Monastery of Megisti Lavra), Barocci 171 (Oxford) and Revilla 83 (Escorial).

RESULTS

The exhaustive study of the "About the Antidotes" led us to the interpretation of 293 plant names among which we recognized 39 medicinal plants listed by the European Medicines Agency, (Herbal Medicines, www.ema.eu); the therapeutic indications of some of them provided by Myrepsos were similar or related to their current ones, as given in their monographs. The plants belong to various families of which the most frequent are: Apiaceae 10.6%; Lamiaceae 9.2%; Asteraceae 8.9%; Fabaceae 6.8% and Rosaceae 5.1%. The most frequently mentioned plants even under several different names are the following: Apium graveolens L., Crocus sativus L., Nardostachys jatamansi (D. Don) DC., Zingiber officinale Roscoe, Rosa centifolia L., Syzygium aromaticum (L.) Merr. & L.M. Perry, Papaver somniferum L., Costus sp., Petroselinum crispum (Mill.) Fuss, Anethum graveolens L., Foeniculum vulgare Mill., Daucus carota L.

CONCLUSIONS

This research led us to the conclusion that the content of "About the Antidotes" is a valuable source for the study of recipes based mainly on medicinal plants, most of them inherited from classic ancient Greek and Hellenistic periods.

Gilthead seabream (Sparus aurata) response to three music stimuli (Mozart--"Eine Kleine Nachtmusik," Anonymous--"Romanza," Bach--"Violin Concerto No. 1") and white noise under recirculating water conditions

This study presents the results of the response of Sparus aurata to three different musical stimuli, derived from the transmission (4 h per day, 5 days per week) of particular music pieces by Mozart, Romanza and Bach (140 dB(rms) re 1 μPa), compared to the same transmission level of white noise, while the underwater ambient noise in all the experimental tanks was 121 dB(rms) re 1 μPa. Using recirculating sea water facilities, 10 groups, 2 for each treatment, of 20 specimens of 11.2 ± 0.02 g (S.E.), were reared for 94 days, under 150 ± 10 l× 12L-12D, and were fed an artificial diet three times per day. Fish body weight showed significant differences after 55 days, while its maximum level was observed after the 69th day until the end of the experiment, the highest value demonstrated in Mozart (M) groups, followed by those of Romanza (R), Bach (B), control (C) and white noise (WN). SGR (M = B), %WG (M = B) and FCR (all groups fed same % b.w.) were also improved for M group. Brain neurotransmitters results exhibited significant differences in DA-dopamine, (M > B), 5HIAA (C > B), 5HIAA:5HT (WN > R), DOPAC (M > B), DOPAC:DA and (DOPAC + HVA):DA, (C > M), while no significant differences were observed in 5HT, NA, HVA and HVA:DA. No differences were observed in biometric measurements, protease activity, % fatty acids of fillet, visceral fat and liver, while differences were observed regarding carbohydrase activity and the amount (mg/g w.w.) of some fatty acids in liver, fillet and visceral fat. In conclusion, present results confirm those reported for S. aurata, concerning the observed relaxing influence--due to its brain neurotransmitters action--of the transmission of Mozart music (compared to R and B), which resulted in the achievement of maximum growth rate, body weight and improved FCR. This conclusion definitely supports the musical "understanding" and sensitivity of S. aurata to music stimuli as well as suggesting a specific effect of white noise.

An Ethanol Extract of Hawaiian Turmeric: Extensive In Vitro Anticancer Activity Against Human Colon Cancer Cells

CONTEXT

Turmeric (Curcuma longa) is a food spice and colorant reported to be beneficial for human health. Curcumin (diferuloylmethane) is the major ingredient in turmeric, and existing data suggest that the spice, in combination with chemotherapy, provides a superior strategy for treatment of gastrointestinal cancer. However, despite its significant effects, curcumin suffers from poor bioavailability, due to poor absorption in the body.

OBJECTIVE

The research team intended to evaluate a liquid extract of turmeric roots (TEx) that the team had formulated for its in vitro, anticancer activity against several human, colorectal cancer cell lines.

DESIGN

The research team performed in vitro studies evaluating the anticancer efficacy via short and long-term assays and also evaluated invasion using Matrigel (Corning Life Sciences, Tewksbury, MA, USA). Further, in vitro anticancer activity of TEx was tested against 3-D cultures of HCT166 spheroids, which were subsequently analyzed by flow cytometry.

SETTING

ADNA, Inc, Columbus, OH, USA; Foundation for Biomedical Research of the Academy of Athens, Athens, Greece; and Laboratory of Pharmacology, Faculty of Medicine, University of Thessaly, Larissa, Greece.

INTERVENTION

The study used 4 human cell lines of colorectal cancer-HT29, HCT15, DLD1, and HCT116-and 2 breast cancer cell lines-SW480 and MDA-MB231. For a short-term assay, the extract was dissolved into culture mediums of HT29, HCT15, DLD1, HCT116, and SW480 at four 10-fold dilutions (100 to 0.1 μg/mL). For a long-term assay, TEx was added to the cultures of the same cell lines at 3 dilutions-20, 10, and 5 μg/mL. For an invasion assay, 100 µL per well of Matrigel was added and allowed to polymerize prior seeding of the MDA-MB231 cells. For cultures treated with the TEx, the TEx was mixed with the cell suspension prior to the seeding step. For the spheroid testing, the TEx was added to HCT116 cells either at the beginning of an experiment (ie, before the addition of the cancer cells), which was a chemopreventive approach, or 48 h later, on the addition of cells to the wells to allow the generation of spheroids, which was a chemotherapeutic approach.

OUTCOME MEASURES

The in vitro activities of TEx were evaluated using a 48-h-incubation, short-term assay and a 2-wk, long-term (clonogenic) assay. To analyze the anti-invasive activity of the extract, images for the Matrigel invasion assay were taken with a camera at the 24-h time point. The in vitro, anticancer activity of TEx was also tested against 3-D cultures of HCT116 spheroids that were subsequently analyzed using flow cytometry.

RESULTS

TEx had potently inhibited the growth of all human colon cancer cell lines tested in a dose- and time-dependent manner. TEx inhibited the formation of HCT116 spheroids when the cells were incubated with the extract. The extract also disrupted the formation of tubules formed by MDA-MB231 cells grown on Matrigel at concentrations that did not affect the overall viability of the cells, indicating a potent anti-invasive activity.

CONCLUSIONS

These data suggest a potential therapeutic activity for TEx against human colon cancer, most likely due to the enhanced bioavailability of the turmeric.

Cell death-inducing effect of novel palladium(II) and platinum(II) complexes on non-small cell lung cancer cells in vitro

PURPOSE

Treatment for lung cancer is still far from satisfying rates. Therefore, there is a need for novel anticancer agents. For this purpose, novel platinum and palladium complexes {[Pd(sac)(terpy)](sac)·4H(2)O (Complex 1), [Pt(sac)(terpy)](sac)·5H(2)O (Complex 2), [PdCl(terpy)](sac)·2H(2)O (Complex 3), [PtCl(terpy)](sac)·2H(2)O (Complex 4)} have been tested against three different non-small cell lung cancer cell lines (A549, H1299, PC-3).

METHODS

Growth-inhibiting effects have been tested by the MTT and ATP viability assays. Apoptosis has been detected by the caspase-cleaved cytokeratin 18 (M30-antigen) assay. Necrosis has been detected by staining the cells with fluorescent dyes. Mitotic index has been calculated by counting the mitotic figures after staining with hematoxylin.

RESULTS

The complex 3 exhibited significant anti-growth effects, and its anti-growth effect was more powerful than that of cisplatin that is a standard chemotherapeutic agent for this type of cancer. The complexes did not induce apoptosis, while necrosis clearly took place.

CONCLUSIONS

Novel Pd(II) complex ([PdCl(terpy)](sac)·2H(2)O) seems to represent a potentially active drug against non-small cell lung cancer cell lines, and further studies in vivo are warranted.

The labdane diterpene sclareol (labd-14-ene-8, 13-diol) induces apoptosis in human tumor cell lines and suppression of tumor growth in vivo via a p53-independent mechanism of action

The labdane diterpene sclareol has demonstrated significant cytotoxicity against human tumor cell lines and human colon cancer xenografts. Therefore, there is need to elucidate the mode of action of this compound as very little information is known for the anticancer activity of sclareol and other labdane diterpenes, in general. COMPARE analysis of GI(50) values for a number of human cancer cell lines was initially implicated in an effort to assign a putative mechanism of action to the compound. Sclareol-induced cell cycle arrest and apoptosis were assessed by flow cytometry and Western blot analyses. Finally, the anticancer ability of sclareol in vivo was assessed by using human colon cancer xenograft/mouse models. Sclareol arrested in vitro the growth of p53-deficient (HCT116(p53-/-)) human colon cancer cells and subsequently induced apoptosis by activating both caspases-8 and -9. Intraperitoneal administration of liposome-encapsulated sclareol at the maximum tolerated dose induced a marked growth suppression of HCT116(p53-/-) tumors established as xenografts in immunodeficient NOD/SCID mice. In conclusion, we demonstrate herein that sclareol kills human tumor cells by inducing arrest at the G(1)-phase of the cell cycle followed by apoptosis that involves activation of caspases-8, -9 and -3 via a p53-independent mechanism. These findings suggest that liposome-encapsulated sclareol possesses chemotherapeutic potential for the treatment of colorectal and other types of human cancer regardless of the p53-status.

Effects of the active constituents of Crocus sativus L., crocins, in an animal model of anxiety

Crocus sativus L. is a plant cultivated in various parts of the world. Crocins are among the active components of Crocus sativus L. The present study was designed to investigate in the rat whether or not crocins possess anxiolytic properties. For this aim, the light/dark test was selected. Either crocins, at a dose which did not influence animals' motor activity (50mg/kg), or diazepam (1.5 mg/kg), significantly increased the latency to enter the dark compartment and prolonged the time spent in the lit chamber in the rats. Conversely, lower doses of crocins (15-30 mg/kg) did not substantially modify animals' behaviour. The present results indicate that treatment with these active constituents of Crocus sativus L. induce anxiolytic-like effects in the rat.

Prolactin concurrently activates src-PLD and JAK/Stat signaling pathways to induce proliferation while promoting differentiation in embryonic astrocytes

In normal development, embryonic astrocytes progress through their cell lineage by acquiring differentiation, by apoptosis, and by proliferation. In this study, we show that embryonic astrocytes may maintain and make gains in differentiation as they simultaneously progress through one cell cycle when induced by prolactin (PRL). Prolactin induced the majority of astrocytes to incorporate bromodeoxyuridine (BrdU) with a four-fold increase over controls after 18 h of exposure. Investigating possible mitogenic signaling pathways we show for the first time that prolactin is coupled to a sustained phospholipase D (PLD) activation, with an efficacy similar to the phorbol ester and astrocytic mitogen 12-tetradecanoylphorbol-13-acetate (TPA). Both cyclosporine and suramin abolished this activation. Staurosporine and calphostin C also inhibited the PRL effect by 50%, consistent with involvement of protein kinase C-(PKC)-alpha, the major PKC isoform in astrocytes. Genistein and PP1 blocked the activation indicating additional regulation by cytosolic tyrosine kinases. This profile of PLD activation was suggestive of a PLD I isoform and a mitogenic response. Upon completion of the cell cycle, analysis of glia fibrillary acidic protein (GFAP) and vimentin abundance, and glutamine synthetase (GS) activity showed that astrocytes had gained in expression of differentiation markers. Moreover, the intensity of GFAP immunofluorescence was greater per cell, as was the length of the cell processes. In exploring the signaling for prolactin-induced differentiation we found that prolactin activated the tyrosine kinase Janus kinase (JAK) 2 and significantly stimulated tyrosine, phosphorylation of the prolactin receptor. Stat 1 and 3 were also activated presumably downstream to JAK2 activation. A rapid translocation of the cytosolic Stats over the nucleus was seen in nearly every astrocyte corresponding well with the gains in GFAP per cell. The Stats translocation did not depend on MEK-ERK inhibition by PD98059, inhibition of p38 by 1 microm SB203580, or Src kinase family inhibition by PP1. Our results demonstrate the ability of PRL to concurrently induce activation of PLD, a mitogenic signaling pathway in astrocytes, and prolonged stimulation of Stat1, compatible with the increased GFAP upregulation and cell differentiation. Considered together this data may provide an explanation on the fast gain in both numbers and differentiation in the astrocytic population during development (HD 09402, CRF).

Evidence for plasticity in neurotransmitter expression in neuronal cultures derived from 3-day-old chick embryo

We have previously reported the developmental profiles of glutamate decarboxylase (GAD) and choline acetyltransferase (ChAT) bio- and immunocytochemically, assessing GABAergic and cholinergic neuronal phenotypes respectively, in neuroblast-enriched cultures from 3-day-old chick embryo, plated on poly-L-lysine. We have also reported that collagen as culture substrate inhibits neuronal aggregation and neuritic fasciculation in this culture system. In this study we assessed the same parameters for cultures on collagen. In addition, we evaluated the effects of nerve growth factors (NGF) on cholinergic and GABAergic expression on neurons plated either on polylysine or collagen. We found that non-neuronal cells and NGF prolonged the survival of cholinergic and GABAergic neuronal populations and that both markedly stimulated GABAergic expression. In contrast, cholinergic expression was only enhanced by NGF. Immunostaining for GABA and ChAT reflected the biochemical findings. Glutamine synthetase and cyclic nucleotide phosphohydrolase, used as markers for astrocytes and oligodendrocytes respectively, showed very low activity in both substrata and were not related to GAD or ChAT peak activities. Our findings suggest that humoral factors and cell-cell contacts markedly influence neuronal phenotypic expression in culture. Moreover, it appears that during early neuronal differentiation GABAergic neurons are more responsive to microenvironmental regulation compared to cholinergic neurons.

Developmental profile of glutamine synthetase in lines of mice bred for ethanol sensitivity

Glutamine synthetase (GS) activity was used as a marker to examine differences in astrocyte development in mice selectively bred for ethanol sensitivity: long sleep (LS), short sleep (SS), mild ethanol withdrawal (MEW), severe ethanol withdrawal (SEW) and control ethanol withdrawal (CEW). We found that 1) GS activity in MEW and SEW was higher than in LS and SS during the first 2 weeks of postnatal development, in the forebrain but not in the cerebellum; 2) lower GS activity was observed consistently in all areas examined with the SS mice as compared to the LS; 3) glutamine synthetase activity in MEW and SEW differed significantly from their controls (CEW) during the early developmental period regardless of the brain region examined; however, after 30 days of maturation, GS activity in SEW was higher than that in MEW and CEW in the forebrain. Astrocytes are known to contribute in the regulation of the neuronal microenvironment. Therefore, we interpret the differences we found in astrocytic function during early brain development among these lines of mice to account in part for the neuronal predisposition to ethanol sensitivity.

Early and late passage C-6 glial cell growth: similarities with primary glial cells in culture

Earlier studies in our laboratory have shown that C-6 glial cells in culture exhibit astrocytic properties with increasing cell passage. In this study, we tested the responsiveness of early and late passage C-6 glial cells to various cultures conditions: culture substrata (collagen, poly-L-lysine, plastic), or supplements for the culture medium, DMEM, [fetal calf, or heat inactivated (HI) serum, or media conditioned from mouse neuroblastoma cells (NBCM) or primary chick embryo cultured neurons (NCM)]. Glutamine synthetase (GS) and cyclic nucleotide phosphohydrolase (CNP), astrocytic and oligodendrocytic glial markers, were used. Cell number and protein content increased exponentially with days in culture regardless of the type of the substratum or cell passage. Differences in cell morphology among the three types of substratum were also reflected on GS activity, which rose by three-fold on culture day 3 for cells grown on collagen; thereafter, GS profiles were similar for all substrata. This early rise in GS is interpreted to reflect differential cell adhesion processes on the substrata; specifically, cell adhesion on the collagen stimulated differentiation into "astrocytic phenotype". Analogous to immature glia cells in primary cultures, early passage C-6 glial cells responded to neuronal factors supplied either from NCM or NBCM by expressing reduced GS activity, the astrocytic marker and enhanced CNP activity, the oligodendrocytic marker. Thus, early passage cells can be induced to express either astrocytic or oligodendrocytic phenotype. In accordance with our previous reports on primary glial cells, late passage C-6 cells exhibit their usual astrocytic behavior, responding to serum factors with GS activity. Moreover, whereas NCM or NBCM alone markedly lowered GS activity, a combination with serum restored activity. The present findings confirm our previous observations and further establish the C-6 glial cells as a reliable model to study immature glia.

Cholinergic neurons in cultures derived from three-, six- or eight-day-old chick embryo: a biochemical and immunocytochemical study

Cultures were prepared by dissociating 3-day-old whole chick embryos, or 6- or 8-day-old chick embryo cerebral hemispheres. The dispersed cells were plated onto poly-L-lysine coated dishes in Dulbecco's modified Eagle's medium fortified with 10% fetal bovine calf serum. Immunocytochemistry, histochemistry and biochemistry were used to characterize the cholinergic neurons in these cultures. Double staining for acetylcholinesterase (AChE) and neurofilament revealed that a high percentage of neurons also contained AChE; fewer neurons though were positive for choline acetyltransferase (ChAT). The presence of AChE in non-cholinergic neurons was interpreted to be indicative of 'cholinoceptive' neurons in culture. The developmental profile for ChAT activity in cultures derived from 3-day-old whole chick embryos was previously described; we have reported that activity reached high levels by 7 days in culture. In this study we found that in cultures derived from 6-day-old chick embryos ChAT activity increased slowly up to 6 days in culture and rose markedly thereafter; in contrast, in cultures derived from 8-day-old chick embryos activity was low until day 9 and rose moderately thereafter. The differences in ChAT expression between cultures derived from chick embryos of different developmental stages may reflect a loss of plasticity of the cholinergic population with age.

Factors influencing neuronal growth in primary cultures derived from 3-day-old chick embryos

We compared neuronal growth patterns in primary cultures prepared by dissociating 3-day-old chick embryos, either whole embryo (E3WE) or head only (E3H) and plating the dispersed cells onto Petri dishes coated with either poly-L-lysine, collagen or laminin. The culture medium was Dulbecco's Modified Eagle's Medium (DMEM), supplemented with either 5 or 10% fetal bovine calf serum (FCS). As we have previously described, in E3WE cultures on poly-L-lysine the neuronal primary growth patterns were aggregation with neuritic fasciculation, presence of growth cones with microspikes and very few flat cells. In contrast with cultures grown on poly-L-lysine, in cultures grown on collagen or laminin the distinct growth pattern was extensive networks of isolated and differentiated neurons lying on acquired monolayers of flat cells. When 5% FCS was used, as compared to 10% FCS, neuronal aggregates were fewer and smaller on poly-L-lysine; on collagen or laminin a tendency to aggregate was observed. Several differences were observed in the E3H cultures when compared to E3WE: (a) aggregates were less numerous with the prevailing pattern being a web-like, self-contained aggregate; (b) aggregates connected with other aggregates or flat cells were rare and the aggregate adhesivity was minimized; (c) neurons on collagen or laminin formed networks with the exception of a few, small aggregates displaying no fasciculation; (d) flat cells did not form a monolayer but islets which hosted the neuronal meshy networks. We attribute these differences in the growth patterns between the various types of cultures to be the combined result of a variety of environmental signals, derived from the provided substrata, the serum and the nonneuronal cell factors and cell surface, all primarily regulating neuronal adhesivity.

Differential maturation of mu and delta opioid receptors in the chick embryonic brain

The developmental profiles of the binding of mu and delta opiate receptors agonists was investigated using the chick embryo brain. Binding of opioids was performed at embryonic days 5, 6, 15, 18, and 20 in the developing chick embryo brain. [3H]dihyromorphine was used as a mu ligand and with 5 X 10(-7) M levorphanol for non-specific binding, and [3H](D-Ala2-D-Leu5)-enkephalin was used as a delta with 5 X 10(-7) M (D-Ser-Gly-Phe-Leu-Thr)-enkephalin for non-specific binding. Crude membranes were prepared from whole brain at days 5, 6 and cerebral hemispheres at days 15, 18, and 20 of embryonic age. Both mu and delta opiate receptors were present during early embryogenesis and as early as day 5. Analysis of binding sites revealed high and low affinity mu sites during early embryogenesis but only one delta site. By 18 days of embryonic age, only one mu site remained. This developmental change is interpreted as a transitory state of the receptor to the adult mu pattern. The presence of only one delta site is constant throughout embryonic age; it is high during early embryogenesis reaching a lower level by 18 days. The presence of a dual binding site pattern for the mu receptor in early embryogenesis is implicated to have a functional significance in the pluripotential role of the endogenous opioids in early development.

Cholinergic neurotoxicity induced by ethylcholine aziridinium (AF64A) in neuron-enriched cultures

The sequence of events in neuronal changes induced by the cholinotoxin ethylcholine aziridinium (AF64A) was studied. Neuron-enriched cultures derived from 8-day-embryonic chick cerebra were treated with AF64A at concentrations of 10(-5), 10(-4) and 10(-3) M. Choline acetyltransferase (ChAT) was used as an index of cholinergic neurons. Changes in cell morphology, the immunocytochemical and biochemical presence of ChAT, and DNA and protein content were assessed. Neuron-enriched cultures exposed to AF64A showed a dose-dependent response; after 24 h of exposure to 10(-3) M toxin all cells were dead, whereas a concentration of 10(-5) M did not alter culture morphology or DNA and protein contents. Despite the lack of cytological changes and the presence of ChAT immunoreactivity, biochemically assessed ChAT activity was reduced 36% in 10(-5) M treated cultures. Thus, the implicated decrease in acetylcholine synthesis in these cells cannot entirely account for the neuronal degeneration. Simultaneous exposure of cultures to both AF64A and 10 times higher concentrations of choline chloride delayed or diminished the neurotoxic changes. The protective effect of high choline concentrations was interpreted as evidence of competition between choline and AF64A for the high affinity choline transport system and as constituents in the cell membrane. Examination of the temporal sequence of cytotoxic changes in 10(-4) M exposed cultures revealed that disruption of neuronal aggregates and fragmentation of neurites occurred between 4 and 8 hours of exposure. After 24 h, some neurons survived but with attenuated arbors; in contrast, astrocytes appeared intact, suggesting that glial cells are more resistant than neurons to the toxic effects of AF64A. These findings suggest this culture model may be useful to further elucidate the mechanisms of AF64A drug action and study differentiation of cultured neuronal populations in the absence of cholinergic cells.

Effects of neuron-conditioned medium and fetal calf serum content on glial growth in dissociated cultures

The influence of the microenvironment as assessed by medium conditioned by 6-day-old chick embryo neurons in culture and of the nutrients derived from fetal bovine serum was evaluated in cultures of primary chick embryo glial cells. Glia-enriched cultures from 15-day-old chick embryo were incubated from culture days 3-9 with various concentrations of neuron-conditioned medium, with or without 10% fetal bovine serum in the final culture medium. Also, glial growth was studied in cultures with 5%, 10% or 20% fetal bovine serum in the medium. Glutamine synthetase and 2',3',-cyclic nucleotide 3'-phosphohydrolase were used as astrocytic and oligodendrocytic markers, respectively. Cultures were harvested at day 9. The presence of neuron-conditioned medium in the cultures was associated with persistence of immature glioblast-like cells. This persistence of glial immature cells was also reflected by the lower glutamine synthetase activity in the cultures with neuron-conditioned medium as compared to cultures with neuron-conditioned medium and fetal calf serum. In cultures with 5% neuron-conditioned medium without fetal bovine serum, cyclic nucleotide phosphohydrolase activity was increased. We are assuming that the input of neurons to the microenvironment is partially mediated through the neuron-conditioned medium. Thus, the present findings show that neurons influence the growth and differentiation of glial cells in culture.

An unconventional response of adenylate cyclase to morphine and naloxone in the chicken during early development

The developmental profile of basal, NaF- and forskolin-stimulated adenylate cyclase [ATP-pyrophosphatelyase (cyclizing), EC 4.6.1.1] activity was established throughout the 21-day embryonic age of the chicken. The highest activities were observed from day 6 to day 8. Morphine inhibited NaF- and forskolin-stimulated brain adenylate cyclase activities only at days 6-8. The inhibition was not reversed by the antagonist naloxone, which also inhibited the enzyme during the same embryonic period and had no inhibitory effect thereafter. Thus, this action of morphine is not mediated through the conventional opiate receptor-adenylate cyclase system. We propose that the temporal specificity of this effect of morphine may play a role in the development of prenatal opiate effects.

Effects of opiates on the growth of neuron-enriched cultures from chick embryonic brain

Neuron-enriched cultures derived from 6-day-old chick embryo cerebral hemispheres were treated with morphine or methadone, 10(-5) M or 10(-6) M, on days 4-6 or 6-8 in culture and were evaluated morphologically and biochemically at day 9 using phase contrast microscopy and choline acetyltransferase activity (ChAT) as a cholinergic marker. The treatment of the cultures with morphine markedly affected their growth pattern; specifically, we observed an increased number of flat cells presumptively glia, and aggregates sided by flat cells and devoid of thick bundles of neuritic processes that normally characterize neuron-enriched cultures. These morphologic changes were reflected in a drastic decrease of ChAT activity in cultures treated from day 4 to day 6 but not from 6 to 8. In contrast to morphine, exposure to 10(-6) M methadone from day 4 to day 6 resulted in reduced ChAT activity but the growth pattern of the cultures remained morphologically intact. We suggest that morphine exerts a general neurotoxic effect whereas methadone may affect some specific cholinergic function.

Growth patterns of glial cells dissociated from newborn and aged mouse brain with cell passage

Glial cell cultures derived from newborn and aged (18-month-old) mouse cerebral hemispheres and maintained up to cell passage 11 were characterized immunocytochemically by using glial fibrillary acidic protein (GFA), and biochemically by using glutamine synthetase (GS), for astrocytes, and 2',3' cyclic nucleotide 3' phosphohydrolase (CNP) for oligodendrocytes. We report here the changes occurring during passages 5-11. GS and CNP activities did not significantly change with cell passage in cultures from newborn mouse. In cultures derived from aged mouse, CNP activity did not change significantly whereas GS activity increased severalfold. A characteristic finding in higher cell passages (passage #7) was the loss of GFA-positive stained cells and the appearance of multinucleated cells. We interpret these changes in culture to represent possible signs of cellular senescence.

Growth patterns of primary cultures dissociated from 3-day-old chick embryos: morphological and biochemical comparisons

Cultures were prepared by dissociating 3-day-old whole chick embryos and plating the dispersed cells on poly-L-lysine-coated dishes in Dulbecco's Modified Eagle's Medium with 10% fetal calf serum. By 48 hr in culture, aggregates and neuritic sprouting were observed. Long neuritic bundles connecting cell aggregates were evident by 4 days in culture. Consistent patterns throughout the lifespan of the cultures were contacts between neurites, and flat isolated cells, presumptively glial, emerged. Throughout the lifespan of the cultures, the cholinergic cell population was characterized histochemically by the method of Karnovsky and Roots and biochemically by assaying choline acetyltransferase. By 4 days in culture, all aggregates showed light cholinesterase-positive staining; however, with days in culture, several aggregates had no staining, and some positive-stained aggregates were interconnected with other aggregates showing only spotted positive staining. Choline acetyltransferase activity showed a developmental profile in agreement with the histological findings. The early presence of choline acetyltransferase activity is taken as indication of the early commitment of cholinergic neurons.

Glial cell growth in culture: influence of living cell substrata

The role of the microenvironment in the growth of glial cells in culture has been the topic of ongoing research in this laboratory. Recently, we reported a study on the contribution of fibroblast cell substratum and extracellular matrix in glial cell growth. In the present study we report data concerning a) the influence of a neuronal-enriched living substratum from chick embryo on the growth of glial cells derived from chick embryonic brain and plated onto the substratum; b) the influence of dissociated cells derived from chick embryonic brain on the growth of established glial cells in culture, and c) the influence of dissociated cells derived from adult rat spinal cord on the growth of established glial cells from newborn rat in culture. The activities of glutamine synthetase (GS) and 2', 3'-cyclic nucleotide 3'-phosphohydrolase (CNP) were the biochemical probes determined for astrocytes and oligodendrocytes, respectively. We found that glial growth as assessed by both enzyme activities, was enhanced when a nervous tissue derived cell population was plated onto a glial-enriched substratum, whereas glial growth was inhibited when the neuronal-enriched population was the cell substratum.

Glial cells dissociated from newborn and aged mouse brain

Changes occurring with days in culture and cell passage in cultured glial cells derived from newborn vs aged (18-mo) mouse cerebral hemispheres were compared. The activities of the enzymes glutamine synthetase (GS), an astrocyte marker, and 2',3'-cyclic nucleotide 3'- phosphohydrolase (CNP), an oligodendrocyte marker, were determined. In addition, glial fibrillary acidic protein (GFA) and glycerol phosphate dehydrogenase (GPDH) immunoreactivity was used to morphologically identify astrocytes and oligodendrocytes, respectively. In cultures derived from newborn mouse cerebral hemispheres, both GS and CNP activity and GFA-positive and GPDH-rhodamine-positive cells were present with cell passage. In general, GS activity did not change in early cell passage in cultures from either newborn or aged mouse; in passage 5, GS was high in both sources of cell populations. CNP activity increased with cell passage in cultures derived from newborn mouse; in cultures derived from aged mouse CNP was low in the primary cultures, increased with cell passages 2 and 3, and declined with passages 4 and 5. The survival of astrocytes as shown by GS and the decline in oligodendrocytes as shown by CNP was also supported by an increase in the proportions of GFA and GPDH immunoreactive cells. We interpret the increase in GS activity to parallel the astrogliosis observed in vivo in the aging brain. Moreover, the decline in oligodendrocytes in culture may represent a shift of balance between glial cell types that appears to be influenced by the age of brain tissue and time in culture.