Biomedical subjects

Nasser Chegini

Publications and source records attributed to Nasser Chegini.

30 records · Page 2Linked to original sources

PubMed2003

Gene expression profile of leiomyoma and myometrium and the effect of gonadotropin releasing hormone analogue therapy.

OBJECTIVE: To determine the profile of differentially expressed genes in leiomyoma and matched unaffected myometrium and to identify the genes whose expression are altered after gonadotropin releasing hormone analogue (GnRHa) therapy. METHODS: Using total RNA isolated from untreated and GnRHa-treated leiomyoma and myometrium subjected to Clontech Atlas 1.2 K cancer microarray containing 1176 known genes, we found transcripts for many cytokines, growth factors and their receptors, adhesion molecules, extracellular matrix, proteases, signaling intermediates, and transcription factors in both tissues. Based on the overall normalization and reproducibility of the results, 328 differentially expressed and regulated genes with at least threefold change in their expression in untreated and GnRHa-treated tissues were chosen for further analysis. RESULTS: The expression value of the 328 genes subjected to significance analysis of microarray showed a total of 100 genes with relative significant change in expression. Of these genes, the expression of 18 was up-regulated and 82 down-regulated in untreated leiomyoma compared with myometrium. In GnRHa-treated tissues, the expression of 34 genes showed a significant decrease in leiomyoma, whereas 27 genes increased and 15 decreased in myometrium compared with their respective untreated tissues. There was no difference in the expression profile of these genes when comparing leiomyoma and myometrium from the GnRHa-treated group. Hierarchical cluster analysis revealed that these differentially expressed or regulated genes, classified based on their biologic functions, are involved in regulation of cell growth/cycle, signal transduction, transcription factors, and cell and tissue structure. CONCLUSION: Microarray analysis allowed us to identify the profile expression of several specific genes in leiomyoma and myometrium whose expression appears to be differentially regulated after GnRHa therapy.

Cell Cycle↗

PubMed2003

Differential expression of interleukins (IL)-13 and IL-15 in ectopic and eutopic endometrium of women with endometriosis and normal fertile women.

PROBLEM: Interleukins (IL) 13 and 15 are key regulators of inflammatory and immune responses, processes that are central to endometriosis and associated abnormalities. The present study examined (1) whether ectopic endometrial tissue expresses IL-13 and IL-15 (2) if their expression differs compared with matched eutopic endometrium and control endometrium from normal fertile women, and (3) if peritoneal fluids (PF) content of these cytokines reflects the disease compared with PF from women with peritoneal adhesions unrelated to endometriosis and those without pelvic pathology. METHODS: The expression of IL-13 and IL-15 mRNA and protein was determined using quantitative RT-PCR, ELISA and immunohistochemistry. RESULTS: Ectopic endometrium expresses IL-13 and IL-15 mRNA and protein with elevated levels compared with eutopic and control endometrium, irrespective of the phases of the menstrual cycle, with predominance in IL-13 expression. Endometrial epithelial cells were found to be the primary site of IL-13 and IL-15 expression. The PF content of IL-13 and IL-15 show a trend toward higher concentrations in women with adhesion and endometriosis, respectively, compared with fertile control without pelvic pathology. CONCLUSION: Interleukins 13 and 15 are expressed in ectopic endometrium and present in PF of women with endometriosis and their elevated expression in ectopic endometrium suggests that these cytokines play a key role in local inflammatory/immune responses that are critical in endometriosis-associated abnormalities.

Endometriosis↗

PubMed2003

Increased expression of monocyte chemoattractant protein-1 (MCP-1) by renal epithelial cells in culture on exposure to calcium oxalate, phosphate and uric acid crystals.

BACKGROUND: During the development of non-infectious kidney stones, crystals form and deposit in the kidneys and become surrounded by monocytes/macrophages (M/M). We have proposed that in response to crystal exposure renal epithelial cells produce chemokines, which attract the M/M to the sites of crystal deposition. We investigated the expression of monocyte chemoattractant protein-1 (MCP-1) mRNA and protein by NRK52E rat renal tubular epithelial cells exposed to calcium oxalate (CaOx), brushite (Br, a calcium phosphate) and uric acid (UA) crystals. METHODS: Confluent cultures of NRK52E cells were exposed to CaOx, Br or UA at a concentration of 250 micro g/ml (66.7 micro g/cm(2)). They were exposed for 1, 3, 6, 12, 24 and 48 h for isolation of mRNA and 24 h for ELISA to determine the secretion of protein into the culture medium. Since cells are known to produce free radicals on exposure to CaOx crystals we also investigated the effect of free radical scavenger catalase on the crystal induced expression of MCP-1 mRNA and protein. RESULTS: Exposure of NRK52E cells to the crystals resulted in increased expression of MCP-1 mRNA and production of the chemoattractant. CaOx crystals were most provocative while UA the least. Treatment with catalase had a negative effect on the increased expression of both MCP-1 mRNA and protein, which indicates the involvement of free radicals in up-regulation of MCP-1 production. CONCLUSION: Exposure to both CaOx and calcium phosphate crystals stimulates increased production of MCP-1. Free radicals appear to be involved in this up-regulation. Results indicate that MCP-1, which is often associated with localized inflammation, may be one of the chemokine mediators associated with the deposition of various urinary crystals in the kidneys during kidney stone formation. Because of the small number of experiments performed here, results must be confirmed by more extensive studies with larger sample size.

Base Sequence↗

PubMed2003

Differential expression, regulation, and induction of Smads, transforming growth factor-beta signal transduction pathway in leiomyoma, and myometrial smooth muscle cells and alteration by gonadotropin-releasing hormone analog.

The objective of this study was to further elucidate the role of TGFbeta and GnRH analog (GnRHa) in leiomyoma growth and regression. We examined the expression of Smads, TGFbeta receptor intracellular signaling molecules, in leiomyoma and myometrial smooth muscle cells (LSMC and MSMC), and determined whether TGFbeta and GnRHa differentially regulate their expression and induction in these cells. Using semiquantitative RT-PCR, Western blot analysis, and immunohistochemistry, we demonstrated that leiomyoma, myometrium, LSMC, and MSMC express receptor-activated Smad3, common Smad4, and the inhibitory Smad7 mRNA and protein and showed that TGFbeta1, in a time-dependent manner, transiently induced Smad7 expression, with Smad3 and Smad4 remaining largely unchanged. TGFbeta1 increased the rate of Smad and phosphorylated Smad3 (pSmad3) induction in both cell types. Pretreatment with TGFbeta type II receptor antisense oligonucleotide resulted in a trend toward a lower TGFbeta-induced pSmad3. GnRHa, in a dose- and time-dependent manner, increased the expression of Smad7 mRNA and the rapid induction of Smad3, Smad4, and Smad7 as well as pSmad3, which declined to control values at doses above 1 micro M in MSMC, but not in LSMC. GnRHa-induced pSamd3 was partly inhibited by a GnRH antagonist (antide). We concluded that leiomyoma, myometrium, LSMC, and MSMC express Smads, which are differentially expressed, induced, and activated by TGFbeta and are altered as a result of GnRHa treatment. These results suggest that TGFbeta and GnRHa mediate their actions through cross-talk involving Smads and most likely other signaling pathways that result in leiomyoma growth and regression.

DNA-Binding Proteins↗

PubMed2003

The expression of Smads in human endometrium and regulation and induction in endometrial epithelial and stromal cells by transforming growth factor-beta.

Human endometrium expresses TGF-beta and TGF-beta receptors where they regulate several endometrial biological activities implicated in embryo implantation, irregular bleeding, endometriosis, and cancer. In the present study, we determined the expression of Smads, intracellular signals that mediate TGF-beta receptors signals from the cell surface to the nucleus, in the endometrium as well as isolated endometrial epithelial (EEC) and stromal (ESC) cells. We also determined whether TGF-beta regulates the expression Smads and activates Smad3 in these cells and endometrial surface epithelial cell line (HES). Using semiquantitative RT-PCR, Western blot analysis, and immunohistochemistry, we found that endometrium, EEC, ESC, and HES express Smad3, -4, and -7 mRNA and protein and contain phosphorylated Smad3 (pSmad3). Smads and pSmad3 were localized in the epithelial and stromal cells with cytoplasmic/nuclear localization. TGF-beta in a dose- and time-dependent manner increased the expression of Smads mRNA and protein, the rate of pSmad3 activation, and Smad3 translocation into the nucleus in ESC and HES. The effect of TGF-beta on pSmad3 induction was, in part, abrogated by the pretreatment of HES and ESC with TGF-beta type II receptor antisense oligonucleotides. We conclude that human endometrium expresses the necessary components of Smad signaling pathway, whose expression and induction in endometrial epithelial and stromal cells are regulated by TGF-beta.

Adult↗

PubMed2003

Gonadotropin releasing hormone analogue therapy alters signal transduction pathways involving mitogen-activated protein and focal adhesion kinases in leiomyoma.

Because gonadotropin releasing hormone analogue (GnRHa) therapy often causes leiomyoma regression, in part through alteration of growth factor and receptor expression, we determined whether GnRHa therapy alters the expression of extracellular signal-regulated kinase (ERK) and focal adhesion kinase (FAK), which are linked to intracellular signaling pathways activated by ovarian steroids, growth factors, and adhesion molecules. Leiomyoma and matched unaffected myometrium were collected from women who received GnRHa therapy (n = 5) and untreated women (n = 10). We determined the expression of ERK1, ERK2, FAK, phosphorylated ERK (pERK1/2), and pFAK using Western blotting and immunohistochemical analysis. Leiomyoma and myometrium expressed ERK1 (44 kD), ERK2 (42 kD), and FAK (125 kD) at variable levels with increased ERK2, pERK, and FAK expression in leiomyoma. We found that GnRHa therapy resulted in a noticeable decrease in ERK2 and FAK, with significant reduction in pERK1/2 and low or undetectable levels of pFAK in both leiomyoma and myometrium compared with the untreated group (P <.05). Immunohistochemically ERK1, ERK2, FAK, pERK1/2, and pFAK were localized in smooth muscle cells and connective tissue fibroblasts in GnRHa-treated and untreated leiomyoma and myometrium, with considerable reduction in their intensity as indicated by HScore in GnRHa-treated tissues. The data provide further evidence that leiomyoma regression induced by GnRHa is mediated in part through a mechanism involving suppression of signal transduction pathways involving growth factors or ovarian steroid and adhesion molecules.

Antineoplastic Agents, Hormonal↗

PubMed2002

Peritoneal molecular environment, adhesion formation and clinical implication.

Whether induced by infection, inflammation, ischemia, and/or surgical injury, peritoneal adhesions are the leading cause of pelvic pain, bowel obstruction and infertility. It is clear that while postsurgical peritoneal wounds heal without adhesions in some patients, others develop severe scarring from seemingly equal procedures; in addition, in the same patient, adhesions can develop at one surgical site and not in another. The mechanisms underlying the predisposition to form adhesions as well as their site specificity are completely unknown. However, a large number of intraperitoneal surgical procedures are performed each day in the USA, and thus many patients are at risk of developing postoperative adhesions. Therefore, understanding of adhesion formation at the molecular level is essential and in the absence of such information, attempts to prevent patients from developing adhesions will remain an empirical process. The unprecedented advancement in molecular biology during the past decade has led to the identification of many biologically active molecules with the potential of regulating inflammatory and immune responses, angiogenesis and tissue remodeling, events that are central to normal peritoneal wound healing and adhesion formation. Although, the insight into their importance in the development of tissue fibrosis has substantially increased, their major roles in peritoneal biological functions and adhesion formation remain at best speculative. This article reviews the clinical implications of adhesions and attempts to highlight some of the key molecules i.e. growth factors, cytokines, chemokines, proteases and extracellular matrix, that are recognized to regulate inflammation, fibrinolysis, angiogenesis, and tissue remodeling, events that are central to peritoneal wound repair and adhesion formation. Finally, the article discusses the potential application and site specific delivery of several active compounds that are developed to alter the local inflammatory and immune response i.e., cytokine/chemokine network, targeted gene delivery and development of a new generation of biomaterials to prevent adhesion formation. Such understanding of peritoneal biology not only assist us to better manage patients with adhesion, but also those with endometriosis and malignant diseases that affect the peritoneal cavity.

Biocompatible Materials↗

PubMed2002

Oxalate ions and calcium oxalate crystals stimulate MCP-1 expression by renal epithelial cells.

BACKGROUND: Crystals of calcium oxalate monohydrate (COM) and excess oxalate ions (OX) stimulate an array of responses inducing localized injury and inflammation in the kidneys. These inflammatory responses are key regulators of development of nephrolithiasis. We propose that monocyte chemoattractant protein-1 (MCP-1), a chemokine with potent chemotactic activity for monocytes/macrophages, is a mediator of local inflammatory responses to COM and OX-induced injury. To test this hypothesis, the effects of COM and OX on the expression of MCP-1 mRNA and protein by NRK52E rat renal tubular cells were investigated. METHODS: Confluent cultures of NRK52E cells were exposed to COM (33 to 267 microg/cm2) or OX (125 to 1000 micromol/L, estimated free oxalate levels of 65.8 to 540 micromol/L) and catalase (400 or 2000 U/mL), a free radical scavenger that protects the cells against detrimental effects of COM and OX, for 1 to 48 hours under serum free conditions. The conditioned media were collected and total cellular RNA isolated from the cells and subjected to enzyme-linked immunosorbent assay (ELISA) and semiquantitative polymerase chain reaction (PCR) to determine the expression of MCP-1 protein and mRNA, respectively. RESULTS: NRK52E cells express MCP-1 mRNA and protein, and the level of their expression significantly increases following treatments with COM and OX in a time and concentration dependent manner. MCP-1 mRNA expression and protein production increased more significantly after exposure to COM than to OX. These responses were significantly reduced following treatments with catalase (2000 U/mL). CONCLUSIONS: NRK52E cells express MCP-1 mRNA and protein, and their levels are altered following COM and OX exposure. Since catalase treatment reduced MCP-1 expression, free radicals may be involved in the up-regulation of MCP-1 production by the epithelial cells. The results suggest that elevated expression of MCP-1, which is often associated with local inflammatory response, may mediate similar reactions including attraction of macrophages seen around the interstitial crystals during the early stages of nephrolithiasis.

Animals↗

PubMed2002

Differential expression of matrix metalloproteinase and tissue inhibitor of MMP in serosal tissue of intraperitoneal organs and adhesions.

OBJECTIVE: To comparatively analyse the expression of matrix metalloproteinase (MMP-3) and tissue inhibitor of MMP (TIMP-2) in serosal tissue of intraperitoneal organs and adhesions, as well as peritoneal fluid and serum of subjects with and without adhesions. DESIGN: Cross sectional study. SETTING: Academic research centres. SAMPLE: Patients undergoing abdominal/pelvic surgery. METHODS: Messenger ribonucleic acid (mRNA) and protein expression using quantitative reverse transcription polymerase chain reaction (Q-RT-PCR), ELISA and immunohistochemistry. RESULTS: All the tissues examined express MMP-3 and TIMP-2 mRNA and protein at consistently varying levels ranging from 100- to 1000-fold and 2- to 10-fold mRNA and protein, respectively. Serosa of uterine, fallopian tube, ovary and partial peritoneum express a higher MMP-3 mRNA compared with small and large bowels and omentum, while TIMP-2 expression was less variable with the highest level found in uterine serosa (P < 0.05). The expression of MMP-3 and TIMP-2 mRNA in adhesions was not significantly different compared with parietal peritoneum. MMP-3 and TIMP-2 protein content in tissue extracts, peritoneal fluids and serum also varied with higher TIMP-2 than MMP-3 (P < 0.05). TIMP-2 levels were lower in serum of subjects with moderate/extensive adhesions compared with subjects without adhesions. Immunoreactive MMP-3 and TIMP-2 proteins were detected in various cell types in these tissues. There was no correlation between MMP-3 and TIMP-2 expression, and age, gender or menstrual status of subjects with or without adhesions. CONCLUSION: MMP-3 and TIMP-2 are expressed at varying levels in serosal tissues of peritoneal organs and adhesions, with higher TIMP-2 than MMP-3. Based on the knowledge that tissue injury alters the expression of MMPs and TIMPs, such variations may predispose an organ to develop more adhesions than others. In addition, the results suggest that serum level of TIMP-2 may represent a marker for subjects who will form adhesions with greater severity.

Adult↗

PubMedDate not supplied

Differential expression of interleukins (IL) IL-13 and IL-15 throughout the menstrual cycle in endometrium of normal fertile women and women with recurrent spontaneous abortion.

Interleukins (IL)-13 and IL-15 are novel cytokines and key regulators of immune/inflammatory related responses that are critical in the outcome of various normal biological and associated abnormalities of the endometrium. The present study determined the temporal and spatial expression of IL-13 and IL-15 mRNA and protein in endometrium of normal fertile women throughout the menstrual cycle, and examined whether profiles of their expression differ from endometrium of women with unexplained recurrent spontaneous abortion (RSA). Using quantitative RT-PCR, ELISA and immunohistochemistry we found that IL-13 and IL-15 mRNA and protein are expressed in control endometrium throughout the menstrual cycle and in RSA (cycle days 21-23) with peak expression detected immediately after and prior to onset of menses, and two distinct periods corresponding to late proliferative and the early-mid secretory phases, respectively. The ratio of IL-13:IL-15 expression revealed a predominance in IL-13 expression during late proliferative/early secretory phase and IL-15 during the mid secretory phase. Compared to control endometrium, endometrium of women with RSA expresses elevated levels of IL-13 and IL-15, with IL-13:IL-15 ratio favoring IL-13. The immunoreactive IL-13 and IL-15 were localized primarily in endometrial luminal epithelial cells with an increased intensity in glandular epithelial and stromal cells in RSA. In conclusion, the results indicate that endometrium of normal fertile women expresses IL-13 and IL-15, with a distinct profile during the menstrual cycle and elevated expression in women with RSA. Although the biological significance of IL-13 and IL-15 in human endometrium and their elevated expression in RSA await investigation, these cytokines with distinct biological functions may regulate endometrial inflammatory/immune responses, tissue repair and receptivity for embryo implantation.

Abortion, Habitual↗

PubMedDate not supplied

Increased expression of interferon-inducible protein-10 during surgically induced peritoneal injury.

Interferon-inducible protein 10 (IP-10) is a key regulator of neutrophils, monocytes, and lymphocytes, cells infiltration whose secretory products play a key role in peritoneal wound healing. The objective of the present study was to determine whether IP-10 is expressed by parietal peritoneum and whether its temporal and spatial expression is altered following surgically induced peritoneal injury during healing. Peritoneal sidewall injuries were induced in mice (N = 60), and the severity of adhesions were graded at 12 hours and 1, 2, 4, and 7 days postsurgery. After collection of peritoneal washes, the injured peritoneum with associated adhesion and intact parietal peritoneum were collected to determine IP-10 mRNA and protein expression using quantitative reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry. Peritoneal injury resulted in adhesion formation with increased severity by day 7 postsurgery. The intact parietal peritoneum expressed IP-10 mRNA, whose level of expression significantly increased following peritoneal injury and reached a maximum at day 4 (p = 0.001), declining to the uninjured control levels by day 7 post-injury. The level of IP-10 in peritoneal washes also increased as a result of peritoneal injury. Immunohistochemically, IP-10 was localized to various inflammatory and immune cells, adhesion fibroblasts, and mesothelial cells, and its intensity increased during the course of wound healing. In conclusion, we showed that parietal peritoneum expresses IP-10 and peritoneal tissue injury results in an elevated level of its expression throughout the early phase of wound healing. The results suggest that IP-10 and its elevated expression may play a role in peritoneal cellular activities that influence the early phases of tissue repair and, possibly, the development of peritoneal adhesions.

Animals↗

PubMedDate not supplied

The effect of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) on granulocyte macrophage-colony stimulating factor (GM-CSF) production by neuronal precursor cells.

AIMS: To determine whether granulocyte macrophage-colony stimulating factor (GM-CSF) production by neuronal precursor (NT2) cells can be regulated by IL-1beta and TNF-alpha. BACKGROUND: We have previously demonstrated GM-CSF expression by neurons of the developing human brain, as well as by NT2 cells. IL-1beta and TNF-alpha upregulate GM-CSF production in glial cells, but GM-CSF regulation in neurons is as yet undefined. We hypothesized that IL-1beta and TNF-alpha would increase GM-CSF mRNA and protein production in NT2 cells. METHODS: The effect of IL-1beta and TNF-alpha on GM-CSF production was assessed by dose response (0 to 2,000 U/ml), and time course (0 to 48 hours incubation) experiments. GM-CSF mRNA and protein production were assessed by quantitative RT-PCR and by ELISA. The effect of these cytokines on cell turnover was determined by BrdU incorporation. RESULTS: IL-1beta increased GM-CSF mRNA and protein expression by NT2 cells. This effect was time and dose dependent, and the effective dose ranging from (20-200 U/ml). TNF-alpha increased GM-CSF mRNA expression to a lesser extent than did IL-1beta (maximal stimulation at 200 U/ml), and a minimal increase in net protein accumulation was noted. Neither cytokine increased NT2 cell turnover. CONCLUSIONS: IL-1beta and TNF-alpha both increase GM-CSF mRNA expression by NT2 cells, but only IL-1beta increases net GM-CSF protein accumulation.

Cell Line↗