Expression of phosphoinositide-specific phospholipase C enzymes in normal endometrium and in endometriosis

The association of circulating lipoprotein lipids and apolipoproteins with risk of endometriosis: a Mendelian randomization study

BACKGROUND

Endometriosis is a poorly understood disease that affects up to 196 million women worldwide and imposes high costs in terms of economic burden and quality of life of women. Traits of circulating lipids have been related to the onset and progression of endometriosis in previous observational studies but the results have remained contradictory.

METHODS

We performed univariable and multivariable Mendelian randomization (MR) analyses using instrument variables to genetically predict the associations of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, triglycerides, and apolipoprotein (apo) A-I and B from the UK Biobank with endometriosis (consisting of 8288 cases and 68 969 controls from the FinnGen consortium). The inverse-variance weighted (IVW) method was used as the primary estimate, whereas MR-Egger and weighted median were conducted as complements to the IVW model.

RESULTS

Increased levels of triglycerides were associated with higher risk of endometriosis and endometriosis of the pelvic peritoneum in the univariable MR analyses. In multivariable MR analysis including apoB, LDL cholesterol, and triglycerides in the same model, triglycerides still retained a robust effect. Decreased levels of apoA-I and HDL cholesterol were associated with increased risk of endometriosis and endometriosis of the pelvic peritoneum in univariable MR analyses. After mutual adjustment, HDL cholesterol retained a robust effect whereas the association for apoA-I was attenuated.

CONCLUSIONS

This is the first MR-based evidence to suggest that triglycerides and HDL cholesterol are the predominant traits that account for the aetiological relationship of lipoprotein lipids with risk of endometriosis, in particular endometriosis of the pelvic peritoneum. Further well-designed randomized controlled trials are needed to address these results.

Cell cycle, apoptosis, cell differentiation, and lipid metabolism gene expression in endometriotic tissue and exposure to parabens and benzophenones

AIM

To describe the expression profile in endometriotic tissue of genes involved in four signaling pathways related to the development and progression of endometriosis (cell cycle, apoptosis, cell differentiation and lipid metabolism) and to explore its relationship with the women exposure to chemicals with hormonal activity released from cosmetics and personal care products (PCPs).

METHODS

This cross-sectional study, encompassed within the EndEA study, comprised a subsample of 33 women with endometriosis. Expression levels of 13 genes (BMI1, CCNB1, CDK1, BAX, BCL2L1, FOXO3, SPP1, HOXA10, PDGFRA, SOX2, APOE, PLCG1 and PLCG2) in endometriotic tissue and urinary concentrations of 4 paraben (PB) and 3 benzophenone (BP) congeners were quantified. Bivariate linear and logistic regression analyses were performed to explore the associations between exposure and gene expression levels.

RESULTS

A total of 8 out 13 genes (61.5 %) were expressed in >75 % of the samples. Exposure to congeners of PBs and/or BPs was associated with the overexpression of CDK1 gene (whose protein drives cells through G2 phase and mitosis), HOXA10 and PDGFRA genes (whose proteins favor pluripotent cell differentiation to endometrial cells), and APOE (whose protein regulates the transport and metabolism of cholesterol, triglycerides and phospholipids in multiple tissues) and PLCG2 genes (whose protein creates 1D-myo-inositol 1,4,5-trisphosphate and diacylglycerol, two important second messengers).

CONCLUSIONS

Our findings suggest that women exposure to cosmetic and PCP-released chemicals might be associated with the promotion of cell cycle and cell differentiation as well as with lipid metabolism disruption in endometriotic tissue, three crucial signaling pathways in the development and progression of endometriosis. However, further studies should be accomplished to confirm these preliminary data.

Phosphoinositide-specific phospholipase C in normal human liver and in alcohol abuse

The phosphoinositide (PI) signal transduction pathway participates in liver metabolism. Abnormal activity or expression of PI-specific phospholipase C (PLC) enzymes has been described in different liver diseases. We resume the role of the PI metabolism in liver and PLC abnormalities in different liver diseases. Moreover, we present the results of PLC analyses in a normal human liver and an alcohol-damaged liver. PLC enzymes and the expression of the corresponding genes in liver biopsies from individuals deceased for complications of the alcoholic liver disease (ALD) at different stages compared with normal controls (deceased individuals with histologically normal livers without alcohol addiction anamnesis) were analyzed by using immunohistochemistry and molecular biology techniques. The expression panel of PLCs was described in normal and alcohol abuse liver. Our observations suggest that the regulation of PLC expression might be due to posttranscriptional events and that alcohol affects the epigenetic control of PLC expression belonging to PI signaling. We also describe the alternate expression of PLCB1 and PLCH1 genes in liver. Our results corroborate literature data suggesting that PLC enzymes are differently expressed in normal versus pathological liver, playing a role in the histopathogenesis of liver tissue damage. The expression and/or localization of selected PLC isoforms is especially affected in alcohol-related liver tissue histopathology. Our present observations confirm that the modulation of protein synthesis plays a role in the regulation of PLC enzymes. We also suggest that this modulation might act at the transcription level. Further studies are required to investigate related epigenetic mechanisms.

Different Expression and Localization of Phosphoinositide Specific Phospholipases C in Human Osteoblasts, Osteosarcoma Cell Lines, Ewing Sarcoma and Synovial Sarcoma

Background: Bone hardness and strength depends on mineralization, which involves a complex process in which calcium phosphate, produced by bone-forming cells, was shed around the fibrous matrix. This process is strictly regulated, and a number of signal transduction systems were interested in calcium metabolism, such as the phosphoinositide (PI) pathway and related phospholipase C (PLC) enzymes. Objectives: Our aim was to search for common patterns of expression in osteoblasts, as well as in ES and SS. Methods: We analysed the PLC enzymes in human osteoblasts and osteosarcoma cell lines MG-63 and SaOS-2. We compared the obtained results to the expression of PLCs in samples of patients affected with Ewing sarcoma (ES) and synovial sarcoma (SS). Results: In osteoblasts, MG-63 cells and SaOS-2 significant differences were identified in the expression of PLC δ4 and PLC η subfamily isoforms. Differences were also identified regarding the expression of PLCs in ES and SS. Most ES and SS did not express PLCB1, which was expressed in most osteoblasts, MG-63 and SaOS-2 cells. Conversely, PLCB2, unexpressed in the cell lines, was expressed in some ES and SS. However, PLCH1 was expressed in SaOS-2 and inconstantly expressed in osteoblasts, while it was expressed in ES and unexpressed in SS. The most relevant difference observed in ES compared to SS regarded PLC ε and PLC η isoforms. Conclusion: MG-63 and SaOS-2 osteosarcoma cell lines might represent an inappropriate experimental model for studies about the analysis of signal transduction in osteoblasts

LPS, Oleuropein and Blueberry extracts affect the survival, morphology and Phosphoinositide signalling in stimulated human endothelial cells

Endothelial cells (EC) act as leading actors in angiogenesis. Understanding the complex network of signal transduction pathways which regulate angiogenesis might offer insights in the regulation of normal and pathological events, including tumours, vascular, inflammatory and immune diseases. The effects of olive oil and of Blueberry extracts upon the phosphoinositide (PI)-specific phospholipase C (PLC) enzymes were evaluated both in quiescent and inflammatory stimulated human umbilical vein EC (HUVEC) using molecular biology (multiliquid bioanalysis) and immunofluorescence techniques. Oleuropein significantly increased the number of surviving HUVEC compared to untreated controls, suggesting that it favours the survival and proliferation of EC. Our results suggest that Oleuropein might be useful to induce EC proliferation, an important event during angiogenesis, with special regard to wound healing. Blueberry extracts increased the number of surviving HUVEC, although the comparison to untreated controls did not result statistically significant. Lipopolysaccharide (LPS) administration significantly reduced the number of live HUVEC. LPS can also modify the expression of selected PLC genes. Adding Blueberry extracts to LPS treated HUVEC cultures did not significantly modify the variations of PLC expression induced by LPS. Oleuropein increased or reduced the expression of PLC genes, and statistically significant results were identified for selected PLC isoforms. Oleuropein also modified the effects of LPS upon PLC genes' expression. Thus, our results corroborate the hypothesis that Oleuropein owns anti-inflammatory activity. The intracellular localization of PLC enzymes was modified by the different treatments we used. Podosome-like structures were observed in differently LPS treated HUVEC.

Endometrial biomarkers for the non-invasive diagnosis of endometriosis

BACKGROUND

About 10% of reproductive-aged women suffer from endometriosis, which is a costly, chronic disease that causes pelvic pain and subfertility. Laparoscopy is the gold standard diagnostic test for endometriosis, but it is expensive and carries surgical risks. Currently, there are no non-invasive tests available in clinical practice that accurately diagnose endometriosis. This is the first diagnostic test accuracy review of endometrial biomarkers for endometriosis that utilises Cochrane methodologies, providing an update on the rapidly expanding literature in this field.

OBJECTIVES

To determine the diagnostic accuracy of the endometrial biomarkers for pelvic endometriosis, using a surgical diagnosis as the reference standard. We evaluated the tests as replacement tests for diagnostic surgery and as triage tests to inform decisions to undertake surgery for endometriosis.

SEARCH METHODS

We did not restrict the searches to particular study designs, language or publication dates. To identify trials, we searched the following databases: CENTRAL (2015, July), MEDLINE (inception to May 2015), EMBASE (inception to May 2015), CINAHL (inception to April 2015), PsycINFO (inception to April 2015), Web of Science (inception to April 2015), LILACS (inception to April 2015), OAIster (inception to April 2015), TRIP (inception to April 2015) and ClinicalTrials.gov (inception to April 2015). We searched DARE and PubMed databases up to April 2015 to identify reviews and guidelines as sources of references to potentially relevant studies. We also performed searches for papers recently published and not yet indexed in the major databases. The search strategies incorporated words in the title, abstract, text words across the record and the medical subject headings (MeSH).

SELECTION CRITERIA

We considered published peer-reviewed, randomised controlled or cross-sectional studies of any size that included prospectively collected samples from any population of reproductive-aged women suspected of having one or more of the following target conditions: ovarian, peritoneal or deep infiltrating endometriosis (DIE).

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from each study and performed a quality assessment. For each endometrial diagnostic test, we classified the data as positive or negative for the surgical detection of endometriosis and calculated the estimates of sensitivity and specificity. We considered two or more tests evaluated in the same cohort as separate data sets. We used the bivariate model to obtain pooled estimates of sensitivity and specificity whenever sufficient data were available. The predetermined criteria for a clinically useful test to replace diagnostic surgery was one with a sensitivity of 94% and a specificity of 79%. The criteria for triage tests were set at sensitivity at or above 95% and specificity at or above 50%, which in case of negative results rules out the diagnosis (SnOUT test) or sensitivity at or above 50% with specificity at or above 95%, which in case of positive result rules in the diagnosis (SpIN test).

MAIN RESULTS

We included 54 studies involving 2729 participants, most of which were of poor methodological quality. The studies evaluated endometrial biomarkers either in specific phases of the menstrual cycle or outside of it, and the studies tested the biomarkers either in menstrual fluid, in whole endometrial tissue or in separate endometrial components. Twenty-seven studies evaluated the diagnostic performance of 22 endometrial biomarkers for endometriosis. These were angiogenesis and growth factors (PROK-1), cell-adhesion molecules (integrins α3β1, α4β1, β1 and α6), DNA-repair molecules (hTERT), endometrial and mitochondrial proteome, hormonal markers (CYP19, 17βHSD2, ER-α, ER-β), inflammatory markers (IL-1R2), myogenic markers (caldesmon, CALD-1), neural markers (PGP 9.5, VIP, CGRP, SP, NPY, NF) and tumour markers (CA-125). Most of these biomarkers were assessed in single studies, whilst only data for PGP 9.5 and CYP19 were available for meta-analysis. These two biomarkers demonstrated significant diversity for the diagnostic estimates between the studies; however, the data were too limited to reliably determine the sources of heterogeneity. The mean sensitivities and specificities of PGP 9.5 (7 studies, 361 women) were 0.96 (95% confidence interval (CI) 0.91 to 1.00) and 0.86 (95% CI 0.70 to 1.00), after excluding one outlier study, and for CYP19 (8 studies, 444 women), they were were 0.77 (95% CI 0.70 to 0.85) and 0.74 (95% CI 0.65 to 84), respectively. We could not statistically evaluate other biomarkers in a meaningful way. An additional 31 studies evaluated 77 biomarkers that showed no evidence of differences in expression levels between the groups of women with and without endometriosis.

AUTHORS' CONCLUSIONS

We could not statistically evaluate most of the biomarkers assessed in this review in a meaningful way. In view of the low quality of most of the included studies, the findings of this review should be interpreted with caution. Although PGP 9.5 met the criteria for a replacement test, it demonstrated considerable inter study heterogeneity in diagnostic estimates, the source of which could not be determined. Several endometrial biomarkers, such as endometrial proteome, 17βHSD2, IL-1R2, caldesmon and other neural markers (VIP, CGRP, SP, NPY and combination of VIP, PGP 9.5 and SP) showed promising evidence of diagnostic accuracy, but there was insufficient or poor quality evidence for any clinical recommendations. Laparoscopy remains the gold standard for the diagnosis of endometriosis, and using any non-invasive tests should only be undertaken in a research setting. We have also identified a number of biomarkers that demonstrated no diagnostic value for endometriosis. We recommend that researchers direct future studies towards biomarkers with high diagnostic potential in good quality diagnostic studies.

U-73122 reduces the cell growth in cultured MG-63 ostesarcoma cell line involving Phosphoinositide-specific Phospholipases C

The definition of the number and nature of the signal transduction pathways involved in the pathogenesis and the identification of the molecules promoting metastasis spread might improve the knowledge of the natural history of osteosarcoma, also allowing refine the prognosis and opening the way to novel therapeutic strategies. Phosphatydil inositol (4,5) bisphosphate (PIP2), belonging to the Phosphoinositide (PI) signal transduction pathway, was related to the regulation of ezrin, an ezrin-radixin-moesin protein involved in metastatic osteosarcoma spread. The levels of PIP2 are regulated by means of the PI-specific Phospholipase C (PLC) enzymes. Recent literature data suggested that in osteosarcoma the panel of expression of PLC isoforms varies in a complex and unclear manner and is related to ezrin, probably networking with Ras GTPases, such as RhoA and Rac1. We analyzed the expression and the subcellular localization of PLC enzymes in cultured human osteosarcoma MG-63 cells, commonly used as an experimental model for human osteoblasts, using U-73122 PLC inhibitor, U-73343 inactive analogue, and by silencing ezrin. The treatment with U-73122 significantly reduces the number of MG-63 viable cells and contemporarily modifies the expression and the subcellular localization of selected PLC isoforms. U-73122 reduces the cell growth in cultured MG-63 ostesarcoma cell line involving PI-specific Phospholipases C.

Impairment and reorganization of the phosphoinositide-specific phospholipase C enzymes in suicide brains

A number of studies suggested that suicide may be associated with specific neurobiological abnormalities. Neurobiology studies focused upon abnormalities of signalling mechanisms with special regard to the serotonin system and the related Phosphoinositide (PI) signalling system. Previous data suggested the involvement of the PI-specific phospholipase C (PLC) family in neuropsychiatric disorders. By using PCR and morphological microscopy observation we examined the whole panel of expression of PLC isoforms in the brains of 28 individuals who committed suicide and in normal controls in order to evaluate the involvement of specific PLC isoforms. The overall PLC expression was reduced and a complex reorganization of the isoforms was observed. The knowledge of the complex network of neurobiological molecules and interconnected signal transduction pathways in the brain of suicide victims might be helpful to understand the natural history and the pathogenesis of the suicidal behavior. That might lead to obtain prognostic suggestions in order to prevent suicide and to new therapeutic agents targeting specific sites in this signalling cascade.

Ezrin-related Phosphoinositide pathway modifies RhoA and Rac1 in human osteosarcoma cell lines

Selected Phosphoinositide-specific Phospholipase C (PI-PLC) enzymes occupy the convergence point of the broad range of pathways that promote Rho and Ras GTPase mediated signalling, which also regulate the activation of ezrin, a member of the ezrin-radixin-moesin (ERM) proteins family involved in the metastatic osteosarcoma spread. Previous studies described that in distinct human osteosarcoma cell lines ezrin networks the PI-PLC with complex interplay controlling the expression of the PLC genes, which codify for PI-PLC enzymes. In the present study, we analyzed the expression and the sub-cellular distribution of RhoA and Rac1 respectively after ezrin silencing and after PI-PLC ε silencing, in order to investigate whether ezrin-RhoGTPAses signalling might involve one or more specific PI-PLC isoforms in cultured 143B and Hs888 human osteosarcoma cell lines. In the present experiments, both ezrin and PLCE gene silencing had different effects upon RhoA and Rac1 expression and sub-cellular localization. Displacements of Ezrin and of RhoA localization were observed, probably playing functional roles.

Total Laparoscopic Hysterectomy: Overtreatment for Misdiagnosed Organic cause or Undertreatment for Idiopathic Chronic Pelvic Pain?

Background

Chronic pelvic pain (CPP) is considered a symptom but also a syndrome with misunderstood pathophysiology and treatment options ranging from conservative management to opioid analgesia and surgical intervention. The aim of this study was to evaluate the role of gynecological surgery in modifying presurgical pain status and reducing the postoperative analgesic use of patients suffering CPP. The second aim of the study was to analyze intraoperative and histological differences in patients who benefited from surgery versus those without benefit.

Methods

An observational study was conducted in 16 fertile women affected by CPP, treated by total laparoscopic hysterectomy (TLH) to solve their pelvic pain. In 7 cases, undetected pelvic endometriosis was found.

Results

A complete resolution of pre-operative pain symptoms (score 0) occurred in 9 patients (56.2%), an occasional pelvic discomfort (score 1) in 2 cases (12.5%), 2 patients reported minimal benefit of pelvic pain (score 2), while in 3 cases, severe pain persisted (score 3). The correlation between intraoperative/histological features and reported symptoms after surgery showed that 7 of 9 patients (77.7%) who benefited from surgery were affected by an organic cause; while 5 women with minimal or no benefits from the surgery did not have any organic disease (idiopathic CPP).

Conclusions

If conservative treatment fails to treat CPP, investigative laparoscopy represents a necessary step to discriminate patients with misdiagnosed organic from idiopathic CPP, selecting those who will potentially benefit from hysterectomy. The role of concomitant appendectomy needs to be defined in surgical treatment of idiopathic CPP.

Ezrin silencing remodulates the expression of Phosphoinositide-specific Phospholipase C enzymes in human osteosarcoma cell lines

Ezrin, a protein belonging to the Ezrin, radixin and moesin (ERM) family, was engaged in the metastatic spread of osteosarcoma. The Protein 4.1, Ezrin, radixin, moesin (FERM) domain of Ezrin binds the membrane Phosphatydil inositol (4,5) bisphosphate (PIP2), a crucial molecule belonging to the Phosphoinositide (PI) signal transduction pathway. The cytoskeleton cross-linker function of Ezrin largely depends on membrane PIP2 levels, and thus upon the activity of related enzymes belonging to the PI-specific phospholipase C (PI-PLC) family. Based on the role of Ezrin in tumour progression and metastasis, we silenced the expression of Vil2 (OMIM *123900), the gene which codifies for Ezrin, in cultured human osteosarcoma 143B and Hs888 cell lines. After Ezrin silencing, the growth rate of both cell lines was significantly reduced and morphogical changes were observed. We also observed moderate variations both of selected PI-PLC enzymes within the cell and of expression of the corresponding PLC genes. In 143B cell line the transcription of PLCB1 decreased, of PLCG2 increased and of PLCE differed in a time-dependent manner. In Hs888, the expression of PLCB1 and of PLCD4 significantly increased, of PLCE moderately increased in a time dependent manner; the expression of PLCG2 was up-regulated. These observations indicate that Ezrin silencing affects the transcription of selected PLC genes, suggesting that Ezrin might influence the expression regulation of PI-PLC enzymes.

Neuropeptide Y reduces the expression of PLCB2, PLCD1 and selected PLC genes in cultured human endothelial cells

Endothelial cells (EC) are the first elements exposed to mediators circulating in the bloodstream, and react to stimulation with finely tuned responses mediated by different signal transduction pathways, leading the endothelium to adapt. Neuropeptide Y (NPY), the most abundant peptide in heart and brain, is mainly involved in the neuroendocrine regulation of the stress response. The regulatory roles of NPY depend on many factors, including its enzymatic processing, receptor subtypes and related signal transduction systems, including the phosphoinositide (PI) pathway and related phospholipase C (PI-PLC) family of enzymes. The panel of expression of PI-PLC enzymes differs comparing quiescent versus differently stimulated human EC. Growing evidences indicate that the regulation of the expression of PLC genes, which codify for PI-PLC enzymes, might act as an additional mechanism of control of the PI signal transduction pathway. NPY was described to potentiate the activation of PI-PLC enzymes in different cell types, including EC. In the present experiments, we stimulated human umbilical vein EC using different doses of NPY in order to investigate a possible role upon the expression PLC genes. NPY reduced the overall transcription of PLC genes, excepting for PLCE. The most significant effects were observed for PLCB2 and PLCD1, both isoforms recruited by means of G-proteins and G-protein-coupled receptors. NPY behavior was comparable with other PI-PLC interacting molecules that, beside the stimulation of phospholipase activity, also affect the upcoming enzymes' production acting upon gene expression. That might represent a mode to regulate the activity of PI-PLC enzymes after activation.

Obstetric Outcomes in Patients Treated for Deep Pelvic Endometriosis

Purpose

The aim of this study was to assess obstetric outcomes and symptoms during and after pregnancy in women submitted to surgical treatment for deep pelvic endometriosis.

Methods

We evaluated 123 women who underwent surgery for severe deep pelvic endometriosis-related symptoms. Interventions were excision of rectovaginal septum nodule with or without rectal or vaginal resection, or excision of nodule of uterosacral ligaments. On the basis of pregnancy desire, patients were submitted to a telephone interview and asked if there had been a pregnancy and its outcome. They were also asked to describe their pain symptoms before, after and during the pregnancy.

Results

From the 123 patients, we selected 43 women desiring pregnancy after surgery, who answered the telephone interview. Twenty-four patients (55.8%) got pregnant. We recorded 34 pregnancies a mean 21.8 ± 17.9 months after surgery. In the group of 25 full-term pregnancies, 14 women (56%) had a vaginal delivery without complications, and 11 (44%) underwent a cesarean section. In only 3 cases, was the indication of cesarean section related to previous surgery. Seventy-one percent of women treated without rectal or vaginal resection delivered vaginally. We also registered 1 case of uncomplicated vaginal delivery in a patient with vaginal resection and another 1 in a patient with rectal resection. In the patients who complained of pain before pregnancy, we observed a resolution of pain symptoms during pregnancy, but after delivery these symptoms reappeared.

Conclusions

In patients submitted to surgery for deep pelvic endometriosis, even in cases of vaginal or rectal resection, a cesarean section is not always mandatory.

Lypopolysaccharide downregulates the expression of selected phospholipase C genes in cultured endothelial cells

The signaling system of phosphoinositides (PI) is involved in a variety of cell and tissue functions, including membrane trafficking, ion channel activity, cell cycle, apoptosis, differentiation, and cell and tissue polarity. Recently, PI and related molecules, such as the phosphoinositide-specific phospholipases C (PI-PLCs), main players in PI signaling were supposed to be involved in inflammation. Besides the control of calcium levels, PI-PLCs contribute to the regulation of phosphatydil-inositol bisphosphate metabolism, crucial in cytoskeletal organization. The expression of PI-PLCs is strictly tissue specific and evidences suggest that it varies under different conditions, such as tumor progression or cell activation. In a previous study, we obtained a complete panel of expression of PI-PLC isoforms in human umbilical vein endothelial cells (HUVEC), a widely used experimental model for endothelial cells. In the present study, we analyzed the mRNA concentration of PI-PLCs in lipopolysaccharide (LPS)-treated HUVEC by using the multiliquid bioanalyzer methodology after 3, 6, 24, 48, and 72 h from LPS administration. Marked differences in the expression of most PI-PLC codifying genes were evident.

Fibroblast growth factor acts upon the transcription of phospholipase C genes in human umbilical vein endothelial cells

Besides the control of calcium levels, the phosphoinositide-specific phospholipases C (PI-PLCs), the main players in the phosphoinositide signalling pathway, contribute to a number of cell activities. The expression of PI-PLCs is strictly tissue specific and evidence suggests that it varies under different conditions, such as tumour progression or cell activation. In previous studies, we obtained a complete panel of expression of PI-PLC isoforms in human umbilical vein endothelial cells (HUVEC), a widely used experimental model for endothelial cells (EC), and demonstrated that the expression of the PLC genes varies under inflammatory stimulation. The fibroblast growth factor (FGF) activates the PI-PLC γ1 isoform. In the present study, PI-PLC expression in FGF-treated HUVEC was performed using RT-PCR, observed 24 h after stimulation. The expression of selected genes after stimulation was perturbed, suggesting that FGF affects gene transcription in PI signalling as a possible mechanism of regulation of its activity upon the AkT-PLC pathway. The most efficient effects of FGF were recorded in the 3-6-h interval. To understand the complex events progressing in EC might provide useful insights for potential therapeutic strategies. The opportunity to manipulate the EC might offer a powerful tool of considerable practical and clinical importance.

Expression of Phosphoinositide-specific phospholipase C enzymes in human osteosarcoma cell lines

The definition of the number and nature of signal transduction pathways networking in the pathogenesis of osteosarcoma raised great interest. Intracellular calcium ions are important second messengers implicated in the control of cell death. The calcium concentration is regulated by signal transduction pathways, including the Phosphoinositides (PI) signaling. Phosphatydil inositol (4,5) bisphosphate (PIP2) is critical for many cellular activities. The levels of PIP2 are regulated by means of Phosphoinositide-specific Phospholipase C (PI-PLC) family of enzymes. We delineated the panel of expression of PI-PLC enzymes in four human osteosarcoma cell lines. In MG-63 cell line, PI-PLC β1, β2, β3, β4, γ1, γ2, δ1, δ3 and ε resulted expressed. In 143B cell line, PI-PLC β1, β2, β3, β4, γ1, γ2, δ1, δ3 and ε were expressed. In SaOS-2 cell line, PI-PLC β1, β3, β4, γ1, γ2, δ1, δ3, ε and η1. In Hs888 cell line, PI-PLC β1, β3, β4, γ1, δ1, δ3, δ4, ε and η1 the administration of U-73122 to cultures briefly modifies the levels of PI-PLC transcripts. The obtained complete expression panel of PI-PLC isoforms will be a useful tool for further functional studies about the role of the PI signal transduction pathway in osteosarcoma.